ORCID Profile
0000-0002-6242-6491
Current Organisation
University of Manchester
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: American Society for Clinical Investigation
Date: 17-07-2017
DOI: 10.1172/JCI94378
Publisher: Springer Science and Business Media LLC
Date: 24-07-2011
DOI: 10.1007/S11427-011-4199-1
Abstract: The plasma membrane calcium ATPases (PMCA) are a family of genes which extrude Ca(2+) from the cell and are involved in the maintenance of intracellular free calcium levels and/or with Ca(2+) signalling, depending on the cell type. In the cardiovascular system, Ca(2+) is not only essential for contraction and relaxation but also has a vital role as a second messenger in signal transduction pathways. A complex array of mechanisms regulate intracellular free calcium levels in the heart and vasculature and a failure in these systems to maintain normal Ca(2+) homeostasis has been linked to both heart failure and hypertension. This article focuses on the functions of PMCA, in particular isoform 4 (PMCA4), in the heart and vasculature and the reported links between PMCAs and contractile function, cardiac hypertrophy, cardiac rhythm and sudden cardiac death, and blood pressure control and hypertension. It is becoming clear that this family of calcium extrusion pumps have essential roles in both cardiovascular health and disease.
Publisher: Oxford University Press (OUP)
Date: 07-03-2010
DOI: 10.1093/CVR/CVQ077
Publisher: MDPI AG
Date: 11-05-2019
DOI: 10.3390/IJMS20092346
Abstract: The regulation of cell death through apoptosis is essential to a number of physiological processes. Defective apoptosis regulation is associated with many abnormalities including anomalies in organ development, altered immune response and the development of cancer. Several signalling pathways are known to regulate apoptosis including the Tumour Necrosis Factor-α (TNF-α) and Hippo signalling pathways. In this paper we review the cross-talk between the TNF-α pathway and the Hippo signalling pathway. Several molecules that tightly regulate the Hippo pathway, such as members of the Ras-association domain family member (RASSF) family proteins, interact and modulate some key proteins within the TNF-α pathway. Meanwhile, TNF-α stimulation also affects the expression and activation of core components of the Hippo pathway. This implies the crucial role of signal integration between these two major pathways in regulating apoptosis.
Publisher: Springer Science and Business Media LLC
Date: 09-07-2020
DOI: 10.1038/S41598-020-67790-0
Abstract: Bradyarrhythmias are an important cause of mortality in heart failure and previous studies indicate a mechanistic role for electrical remodelling of the key pacemaking ion channel HCN4 in this process. Here we show that, in a mouse model of heart failure in which there is sinus bradycardia, there is upregulation of a microRNA (miR-370-3p), downregulation of the pacemaker ion channel, HCN4, and downregulation of the corresponding ionic current, I f , in the sinus node. In vitro, exogenous miR-370-3p inhibits HCN4 mRNA and causes downregulation of HCN4 protein, downregulation of I f , and bradycardia in the isolated sinus node. In vivo, intraperitoneal injection of an antimiR to miR-370-3p into heart failure mice silences miR-370-3p and restores HCN4 mRNA and protein and I f in the sinus node and blunts the sinus bradycardia. In addition, it partially restores ventricular function and reduces mortality. This represents a novel approach to heart failure treatment.
Publisher: MDPI AG
Date: 26-06-2023
Abstract: Background: The administration of the third (or booster) dose of COVID-19 vaccine is important in maintaining protection against SARS-CoV-2 infection or the severity of the disease. In Indonesia, health care workers (HCWs) are among the first to receive a booster dose of the COVID-19 vaccine. In this study, we evaluated the antibody response and adverse events following heterologous booster vaccine using mRNA-1273 among HCWs that were fully vaccinated with inactivated viral vaccine as the priming doses. Methods: 75 HCWs at Dr. Soetomo General Hospital in Surabaya, Indonesia, participated in this study. The level of antibody against the SARS-CoV-2 receptor binding domain was analyzed at 1, 3, and 5 months following the second priming dose and at 1, 3, and 5 months after the booster dose. Results: We found a significantly higher level of antibody response in subjects receiving a booster dose of the mRNA-1273 vaccine compared to those receiving an inactivated viral vaccine as a booster. Interestingly, participants with hypertension and a history of diabetes mellitus showed a lower antibody response following the booster dose. There was a higher frequency of adverse events following injection with the mRNA-1273 vaccine compared to the inactivated viral vaccine, although the overall adverse events were considered minor. Conclusions: A heterologous booster dose using mRNA vaccine resulted in a high antibody response however, participants with hypertension and diabetes mellitus displayed a lower antibody response.
Publisher: Springer Science and Business Media LLC
Date: 15-01-2021
DOI: 10.1038/S41598-021-81170-2
Abstract: Ischaemic heart disease is the world’s leading cause of mortality. Survival rates from acute myocardial infarction (MI) have improved in recent years however, this has led to an increase in the prevalence of heart failure (HF) due to chronic remodelling of the infarcted myocardium, for which treatment options remain poor. We have previously shown that inhibition of isoform 4 of the plasma membrane calcium ATPase (PMCA4) prevents chronic remodelling and HF development during pressure overload, through fibroblast mediated Wnt signalling modulation. Given that Wnt signalling also plays a prominent role during remodelling of the infarcted heart, this study investigated the effect of genetic and functional loss of PMCA4 on cardiac outcomes following MI. Neither genetic deletion nor pharmacological inhibition of PMCA4 affected chronic remodelling of the post-MI myocardium. This was the case when PMCA4 was deleted globally, or specifically from cardiomyocytes or fibroblasts. PMCA4-ablated hearts were however less prone to acute arrhythmic events, which may offer a slight survival benefit. Overall, this study demonstrates that PMCA4 inhibition does not affect chronic outcomes following MI.
Publisher: Oxford University Press (OUP)
Date: 07-09-2012
Abstract: Cancer is caused by defects in the signalling mechanisms that govern cell proliferation and apoptosis. It is well known that calcium-dependent signalling pathways play a critical role in cell regulation. A tight control of calcium homeostasis by transporters and channel proteins is required to assure a proper functioning of the calcium-sensitive signal transduction pathways that regulate cell growth and apoptosis. The plasma membrane calcium ATPase 2 (PMCA2) has been recently identified as a negative regulator of apoptosis that can play a significant role in cancer progression by conferring cells resistance to apoptosis. We have previously reported an inhibitory interaction between PMCA2 and the calcium-activated signalling molecule calcineurin in breast cancer cells. Here, we demonstrate that disruption of the PMCA2/calcineurin interaction in a variety of human breast cancer cells results in activation of the calcineurin/NFAT pathway, upregulation in the expression of the pro-apoptotic protein Fas Ligand and in a concomitant loss of cell viability. Reduction in cell viability is the consequence of an increase in cell apoptosis. Impairment of the PMCA2/calcineurin interaction enhances paclitaxel-mediated cytotoxicity of breast tumoral cells. Our results suggest that therapeutic modulation of the PMCA2/calcineurin interaction might have important clinical applications to improve current treatments for breast cancer patients.
Publisher: Public Library of Science (PLoS)
Date: 17-01-2017
Publisher: Research Square Platform LLC
Date: 16-03-2021
DOI: 10.21203/RS.3.RS-292930/V1
Abstract: BackgroundCoronavirus disease 2019 (COVID-19) is a global health problem that causes millions of deaths worldwide. The clinical manifestation of COVID-19 widely varies from asymptomatic infection to severe pneumonia and systemic inflammatory disease. It is thought that host genetic variability may affect the host's response to the virus infection and thus cause severity of the disease. The SARS-CoV-2 virus requires interaction with its receptor complex in the host cells before infection. The transmembrane protease serine 2 (TMPRSS2) has been identified as one of the key molecules involved in SARS-CoV-2 virus receptor binding and cell invasion. Therefore, in this study we investigated the correlation between a genetic variant within the human TMPRSS2 gene and COVID-19 severity and viral load.ResultsWe genotyped 95 patients with COVID-19 hospitalized in Dr Soetomo General Hospital and Indrapura Field Hospital (Surabaya, Indonesia) for the TMPRSS2 p.Val160Met polymorphism. Polymorphism was detected using a TaqMan assay. We then analysed the association between the presence of the genetic variant and disease severity and viral load. We did not observe any correlation between the presence of TMPRSS2 genetic variant with the severity of the disease. However, we identified significant association between the p.Val160Met polymorphism and the SARS-CoV-2 viral load, as estimated by the Ct value of the diagnostic nucleic acid lification test. Furthermore, we observed a trend of association between the presence of the C allele and the mortality rate in patients with severe COVID-19. ConclusionOur data indicate a possible association between TMPRSS2 p.Val160Met polymorphism and SARS-CoV-2 infectivity and the outcome of Covid-19.
Publisher: Springer Science and Business Media LLC
Date: 29-03-2016
DOI: 10.1038/NCOMMS11074
Abstract: The heart responds to pathological overload through myocyte hypertrophy. Here we show that this response is regulated by cardiac fibroblasts via a paracrine mechanism involving plasma membrane calcium ATPase 4 (PMCA4). Pmca4 deletion in mice, both systemically and specifically in fibroblasts, reduces the hypertrophic response to pressure overload however, knocking out Pmca4 specifically in cardiomyocytes does not produce this effect. Mechanistically, cardiac fibroblasts lacking PMCA4 produce higher levels of secreted frizzled related protein 2 (sFRP2), which inhibits the hypertrophic response in neighbouring cardiomyocytes. Furthermore, we show that treatment with the PMCA4 inhibitor aurintricarboxylic acid (ATA) inhibits and reverses cardiac hypertrophy induced by pressure overload in mice. Our results reveal that PMCA4 regulates the development of cardiac hypertrophy and provide proof of principle for a therapeutic approach to treat this condition.
Publisher: Elsevier BV
Date: 12-2023
Publisher: Baishideng Publishing Group Inc.
Date: 26-10-2021
Publisher: Frontiers Media SA
Date: 30-10-2020
Publisher: Wiley
Date: 26-09-2017
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 20-10-2020
Abstract: The sinus node (SN) is the primary pacemaker of the heart. SN myocytes possess distinctive action potential morphology with spontaneous diastolic depolarization because of a unique expression of ion channels and Ca 2+ ‐handling proteins. MicroRNAs (miRs) inhibit gene expression. The role of miRs in controlling the expression of genes responsible for human SN pacemaking and conduction has not been explored. The aim of this study was to determine miR expression profile of the human SN as compared with that of non‐pacemaker atrial muscle. SN and atrial muscle biopsies were obtained from donor or post‐mortem hearts (n=10), histology/immunolabeling were used to characterize the tissues, TaqMan Human MicroRNA Arrays were used to measure 754 miRs, Ingenuity Pathway Analysis was used to identify miRs controlling SN pacemaker gene expression. Eighteen miRs were significantly more and 48 significantly less abundant in the SN than atrial muscle. The most interesting miR was miR‐486‐3p predicted to inhibit expression of pacemaking channels: HCN1 (hyperpolarization‐activated cyclic nucleotide‐gated 1), HCN4, voltage‐gated calcium channel (Ca v )1.3, and Ca v 3.1. A luciferase reporter gene assay confirmed that miR‐486‐3p can control HCN4 expression via its 3′ untranslated region. In ex vivo SN preparations, transfection with miR‐486‐3p reduced the beating rate by ≈35±5% ( P .05) and HCN4 expression ( P .05). The human SN possesses a unique pattern of expression of miRs predicted to target functionally important genes. miR‐486‐3p has an important role in SN pacemaker activity by targeting HCN4, making it a potential target for therapeutic treatment of SN disease such as sinus tachycardia.
Publisher: Public Library of Science (PLoS)
Date: 30-04-2019
Publisher: American Physiological Society
Date: 07-2017
DOI: 10.1152/PHYSREV.00028.2016
Abstract: The Ca 2+ extrusion function of the four mammalian isoforms of the plasma membrane calcium ATPases (PMCAs) is well established. There is also ever-increasing detail known of their roles in global and local Ca 2+ homeostasis and intracellular Ca 2+ signaling in a wide variety of cell types and tissues. It is becoming clear that the spatiotemporal patterns of expression of the PMCAs and the fact that their abundances and relative expression levels vary from cell type to cell type both reflect and impact on their specific functions in these cells. Over recent years it has become increasingly apparent that these genes have potentially significant roles in human health and disease, with PMCAs1-4 being associated with cardiovascular diseases, deafness, autism, ataxia, adenoma, and malarial resistance. This review will bring together evidence of the variety of tissue-specific functions of PMCAs and will highlight the roles these genes play in regulating normal physiological functions and the considerable impact the genes have on human disease.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 13-10-2017
DOI: 10.1161/CIRCRESAHA.117.311607
Abstract: Downregulation of the pacemaking ion channel, HCN4 (hyperpolarization-activated cyclic nucleotide gated channel 4), and the corresponding ionic current, I f , underlies exercise training–induced sinus bradycardia in rodents. If this occurs in humans, it could explain the increased incidence of bradyarrhythmias in veteran athletes, and it will be important to understand the underlying processes. To test the role of HCN4 in the training-induced bradycardia in human athletes and investigate the role of microRNAs (miRs) in the repression of HCN4. As in rodents, the intrinsic heart rate was significantly lower in human athletes than in nonathletes, and in all subjects, the rate-lowering effect of the HCN selective blocker, ivabradine, was significantly correlated with the intrinsic heart rate, consistent with HCN repression in athletes. Next-generation sequencing and quantitative real-time reverse transcription polymerase chain reaction showed remodeling of miRs in the sinus node of swim-trained mice. Computational predictions highlighted a prominent role for miR-423-5p. Interaction between miR-423-5p and HCN4 was confirmed by a dose-dependent reduction in HCN4 3′-untranslated region luciferase reporter activity on cotransfection with precursor miR-423-5p (abolished by mutation of predicted recognition elements). Knockdown of miR-423-5p with anti-miR-423-5p reversed training-induced bradycardia via rescue of HCN4 and I f . Further experiments showed that in the sinus node of swim-trained mice, upregulation of miR-423-5p (intronic miR) and its host gene, NSRP1, is driven by an upregulation of the transcription factor Nkx2.5. HCN remodeling likely occurs in human athletes, as well as in rodent models. miR-423-5p contributes to training-induced bradycardia by targeting HCN4. This work presents the first evidence of miR control of HCN4 and heart rate. miR-423-5p could be a therapeutic target for pathological sinus node dysfunction in veteran athletes.
Publisher: American Physiological Society
Date: 09-2001
DOI: 10.1152/AJPLUNG.2001.281.3.L740
Abstract: Several cystic fibrosis (CF) mouse models demonstrate an increased susceptibility to Pseudomonas aeruginosa lung infection, characterized by excessive inflammation and high rates of mortality. Here we developed a model of chronic P. aeruginosa lung disease in mice homozygous for the murine CF transmembrane conductance regulator G551D mutation that provides an excellent model for CF lung disease. After 3 days of infection with mucoid P. aeruginosa entrapped in agar beads, the G551D animals lost substantially more body weight than non-CF control animals and were less able to control the infection, harboring over 40-fold more bacteria in the lung. The airways of infected G551D animals contained altered concentrations of the inflammatory mediators tumor necrosis factor-α, KC/N51, and macrophage inflammatory protein-2 during the first 2 days of infection, suggesting that an ineffective inflammatory response is partly responsible for the clearance defect.
Publisher: Elsevier BV
Date: 09-2022
Publisher: Elsevier BV
Date: 05-2011
DOI: 10.1016/J.BBAMCR.2010.12.007
Abstract: Calcium has been unequivocally regarded as a key signal messenger in almost every cell type. Calcium regulates a number of important cellular functions including cell growth, myofilament contraction, cell survival and apoptosis as well as gene transcription. A complex regulatory mechanism of cellular calcium is needed to fine tune the precise calcium concentration in each subcellular location and also to transmit the signals carried by the calcium pool to the correct end target. In this article we will review the recently emerging role of the plasma membrane calcium/calmodulin dependent ATPase isoform 4 (PMCA4) in regulating calcium signalling. We will then focus on the function of this molecule in cardiomyocytes, in which PMCA4 forms protein-protein interactions with several key signalling molecules. Recent evidence has shown in vivo physiological functionalities and possible clinical implications of the PMCA4 signalling complex. This article is part of a Special Issue entitled: 11th European Symposium on Calcium.
Publisher: Elsevier BV
Date: 07-2004
Publisher: MDPI AG
Date: 23-06-2022
Abstract: The association between angiotensin-converting enzyme insertion/deletion (ACE I/D) polymorphisms and plasma ACE levels may allow for the optimization of a preventive intervention to reduce cardiovascular morbidity and mortality in the chronic kidney disease (CKD) population. In this study, we aimed to analyze the association between ACE I/D polymorphism and cardiovascular mortality risk among non-hemodialyzed chronic kidney disease patients. This cross-sectional study examined 70 patients of Javanese ethnic origin with stable CKD who did not receive hemodialysis. ACE I/D polymorphisms, plasma ACE levels, atherosclerotic cardiovascular disease (ASCVD) risk, and cardiovascular mortality risk were investigated. As per our findings, the I allele was found to be more frequent (78.6) than the D allele (21.4), and the DD genotype was less frequent than the II genotype (4.3 vs. 61.4). The ACE I/D polymorphism had a significant direct positive effect on plasma ACE levels (path coefficient = 0.302, p = 0.021). Similarly, plasma ACE levels had a direct and significant positive effect on the risk of atherosclerotic cardiovascular disease (path coefficient = 0.410, p = 0.000). Moreover, atherosclerotic cardiovascular disease risk had a significant positive effect on cardiovascular mortality risk (path coefficient = 0.918, p = 0.000). The ACE I/D polymorphism had no direct effect on ASCVD and cardiovascular mortality risk. However, our findings show that the indirect effects of high plasma ACE levels may be a factor in the increased risk of ASCVD and cardiovascular mortality in Javanese CKD patients.
Publisher: Elsevier BV
Date: 08-2005
Publisher: Humana Press
Date: 2010
DOI: 10.1007/978-1-60761-700-6_18
Abstract: The plasma membrane calcium-calmodulin-dependent ATPase (PMCA) is a calcium-extruding enzymatic pump that ejects calcium from the cytoplasm to the extracellular compartment. Although in excitable cells such as skeletal and cardiac muscle cells PMCA has been shown to play only a minor role in regulating global intracellular calcium concentration, increasing evidence points to an important role for PMCA in signal transduction, in particular in the nitric oxide signaling pathway. Moreover, recent evidence has shown the functional importance of PMCA in mediating cardiac contractility and vascular tone. Here we describe a method in determining PMCA activity in the microsomal membrane preparation from cultured cells that overexpress specific isoform of PMCA by using modified coupled enzyme assay.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2019
DOI: 10.1161/CIRCRESAHA.118.312829
Abstract: Secreted and membrane-bound proteins, which account for 1/3 of all proteins, play critical roles in heart health and disease. The endoplasmic reticulum (ER) is the site for synthesis, folding, and quality control of these proteins. Loss of ER homeostasis and function underlies the pathogenesis of many forms of heart disease. To investigate mechanisms responsible for regulating cardiac ER function, and to explore therapeutic potentials of strengthening ER function to treat heart disease. Screening a range of signaling molecules led to the discovery that Pak (p21-activated kinase)2 is a stress-responsive kinase localized in close proximity to the ER membrane in cardiomyocytes. We found that Pak2 cardiac deleted mice (Pak2-CKO) under tunicamycin stress or pressure overload manifested a defective ER response, cardiac dysfunction, and profound cell death. Small chemical chaperone tauroursodeoxycholic acid treatment of Pak2-CKO mice substantiated that Pak2 loss-induced cardiac damage is an ER-dependent pathology. Gene array analysis prompted a detailed mechanistic study, which revealed that Pak2 regulation of protective ER function was via the IRE (inositol-requiring enzyme)-1/XBP (X-box–binding protein)-1–dependent pathway. We further discovered that this regulation was conferred by Pak2 inhibition of PP2A (protein phosphatase 2A) activity. Moreover, IRE-1 activator, Quercetin, and adeno-associated virus serotype-9–delivered XBP-1s were able to relieve ER dysfunction in Pak2-CKO hearts. This provides functional evidence, which supports the mechanism underlying Pak2 regulation of IRE-1/XBP-1s signaling. Therapeutically, inducing Pak2 activation by genetic overexpression or adeno-associated virus serotype-9–based gene delivery was capable of strengthening ER function, improving cardiac performance, and diminishing apoptosis, thus protecting the heart from failure. Our findings uncover a new cardioprotective mechanism, which promotes a protective ER stress response via the modulation of Pak2. This novel therapeutic strategy may present as a promising option for treating cardiac disease and heart failure.
Publisher: Public Library of Science (PLoS)
Date: 04-06-2018
Publisher: Bentham Science Publishers Ltd.
Date: 05-2006
DOI: 10.2174/138955706776876177
Abstract: The plasma membrane calcium/calmodulin dependent ATPase (PMCA) is a calcium-extruding enzymatic pump important in the control of intracellular calcium concentration. PMCA is the only system for calcium extrusion in the majority of cells. In excitable cells such as cardiomyocytes however, PMCA has been shown to play only a minor role in calcium homeostasis. In these cells the main mechanism of calcium extrusion is the sodium calcium exchanger. However, increasing evidence points to an important role for PMCA in signal transduction in particular in the nitric oxide signalling pathway. In this review we will discuss recent advances that support a key role for PMCA in signal transduction and the potential for therapeutic targeting of this molecule in the treatment of cardiac diseases.
Publisher: Wiley
Date: 10-2007
DOI: 10.1016/J.EJHEART.2007.07.005
Abstract: Mitral valve prolapse (MVP) is common and highly variable in its severity, but the factors underlying this variability are unclear. In this study, we tested the hypothesis that polymorphic variations in Matrix Metalloproteinase (MMP) genes might be predictors of left ventricular (LV) remodelling and severity of regurgitation in MVP. 70 MVP patients and 75 normal subjects were studied. We performed comprehensive echocardiography and analyzed promoter polymorphisms in the MMP-1 and MMP-3 genes. The MMP-3 -1612 5A/6A polymorphism showed strong associations with indices of mitral regurgitation and LV remodelling: Patients with 5A/5A allele had more pronounced remodelling and more severe mitral regurgitation than patients with the 6A/6A or 5A/6A alleles. We then cloned and sequenced 2 kb fragments of MMP-3 promoter from patients with 5A/5A and 6A/6A genotypes and found 4 different sets of promoter haplotypes. Promoter analysis showed that higher promoter activity was related to a more severe phenotype and that the haplotype variants had a more dominant role in determining the activity. Our data identifies the MMP-3 promoter haplotype as a novel marker of an adverse disease course in MVP, suggesting the presence of genetic determinants for the severity of MVP.
Publisher: Springer Science and Business Media LLC
Date: 15-02-2022
Publisher: Elsevier BV
Date: 07-2004
Publisher: Oxford University Press (OUP)
Date: 05-2002
Abstract: Increasingly, cystic fibrosis (CF) is regarded as an inflammatory disorder where the response of the lung to Pseudomonas aeruginosa is exaggerated as a consequence of processes mediated by the product of the CF gene, CFTR. Of importance to any gene-replacement strategy for treatment of CF is the identification of the cell type(s) within the lung milieu that need to be corrected and an indication whether this is sufficient to restore a normal inflammatory response and bacterial clearance. We generated G551D CF mice transgenically expressing the human CFTR gene in two tissue compartments previously demonstrated to mediate a CFTR-dependent inflammatory response: lung epithelium and alveolar macrophages. Following chronic pulmonary infection with P. aeruginosa, CF mice with epithelial-expressed but not macrophage-specific CFTR showed an improvement in pathogen clearance and inflammatory markers compared with control CF animals. Additionally, these data indicate the general role for epithelial cell-mediated events in the response of the lung to bacterial pathogens and the importance of CFTR in mediating these processes.
Publisher: Future Science Ltd
Date: 12-2017
DOI: 10.2144/000114617
Abstract: Continuous optimization of in vitro analytical techniques is ever more important, especially given the development of new materials for tissue engineering studies. In particular, isolation of cellular components for downstream applications is often hindered by the presence of biomaterials, presenting a major obstacle in understanding how cell–matrix interactions influence cell behavior. Here, we describe an approach for western blot analysis of cells that have been encapsulated in self-assembling peptide hydrogels (SAPHs), which highlights the need for complete solubilization of the hydrogel construct. We demonstrate that both the choice of buffer and multiple cycles of sonication are vital in obtaining complete solubilization, thereby enabling the detection of proteins otherwise lost to SAP aggregation. Moreover, we show that the presence of self-assembling peptides (SAPs) does not interfere with the standard immunoblotting technique, offering the potential for use in more full-scale proteomic studies.
Publisher: Elsevier BV
Date: 02-2021
Publisher: Frontiers Media SA
Date: 22-05-2013
DOI: 10.18433/J3PG68
Abstract: Purpose. ATPases, which constitute a major category of ion transporters in the human body, have a variety of significant biological and pathological roles. However, the lack of high throughput assays for ATPases has significantly limited drug discovery in this area. We have recently found that the genetic deletion of the ATP dependent calcium pump PMCA4 (plasma membrane calcium/calmodulin dependent ATPase, isoform 4) results in infertility in male mice due to a selective defect in sperm motility. In addition, recent discoveries in humans have indicated that a single nucleotide polymorphism (SNP) in the PMCA4 gene determines the susceptibility towards malaria plasmodium infection. Therefore, there is an urgent need to develop specific PMCA4 inhibitors. In the current study, we aim to optimise and validate a high throughput screening compatible assay using recombinantly expressed PMCA4 and the HTRF® Transcreener® ADP (TR-FRET) assay to screen a drug library. Methods and Results. PMCA4 membrane microsomes were prepared from HEK293 cells overexpressing PMCA4. Western blot quantification revealed nearly nine-fold increased expression of PMCA4 compared to LacZ (control virus)-infected cells. Maximal PMCA4 microsomal activity was achieved in the TR-FRET assay with 15ng/μl microsomal concentration, 30-minute pre-incubation with compounds at 37°C, and calcium buffering with 1mM EGTA providing 1μM free-calcium. Finally a dose-response curve for carboxyeosin (a non-specific PMCA inhibitor) under optimised conditions showed significant PMCA4 inhibition. Upon confirmation that the assay was suitable for high-throughput screening, we have screened the ChemBioNet small molecule library (~21,000 compounds) against the PMCA4 assay to identify those that are its apparent inhibitors. This screening yielded 1,494 primary hits. Conclusions. We have optimised the HTRF® Transcreener® ADP assay for high-throughput screening to identify PMCA4 inhibitors. The output of the screening c aign has provided preliminary chemical starting points that could be further developed to specific PMCA4 inhibitors for non-hormonal contraception or anti-malaria therapy. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.
Publisher: Oxford University Press (OUP)
Date: 13-03-2021
Abstract: Cardiovascular diseases (CVD) are the leading cause of death in Indonesia, and there are large disparities in access to recommended preventative treatments across the country, particularly in rural areas. Technology-enabled screening and management led by community health workers have been shown to be effective in better managing those at high risk of CVD in a rural Indonesian population however, the economic impacts of implementing such an intervention are unknown. We conducted a modelled cost-effectiveness analysis of the SMARThealth intervention in rural villages of Malang district, Indonesia from the payer perspective over a 10-year period. A Markov model was designed and populated with epidemiological and cost data collected in a recent quasi-randomized trial, with nine health states representing a differing risk for experiencing a major CVD event. Disability-Adjusted Life Years (DALYs) were estimated for the intervention and usual care using disability weights from the literature for major CVD events. Annual treatment costs for CVD treatment and prevention were $US83 under current care and $US144 for those receiving the intervention. The intervention had an incremental cost-effectiveness ratio of $4288 per DALY averted and $3681 per major CVD event avoided relative to usual care. One-way and probabilistic sensitivity analyses demonstrated that the results were robust to plausible variations in model parameters and that the intervention is highly likely to be considered cost-effective by decision-makers across a range of potentially acceptable willingness to pay levels. Relative to current care, the intervention was a cost-effective means to improve the management of CVD in this rural Indonesian population. Further scale-up of the intervention offers the prospect of significant gains in population health and sustainable progress toward universal health coverage for the Indonesian population.
Publisher: BMJ
Date: 08-2022
DOI: 10.1136/BMJGH-2022-008936
Abstract: Community health workers (CHWs) play a critical role in supporting health systems, and in improving accessibility to primary healthcare. In many settings CHW programmes do not have formalised employment models and face issues of high attrition and poor performance. This study aims to determine the employment preferences of CHWs in Malang district, Indonesia, to inform policy interventions. A discrete choice experiment was conducted with 471 CHWs across 28 villages. Attributes relevant to CHW employment were identified through a multistage process including literature review, focus group discussions and expert consultation. Respondents’ choices were analysed with a mixed multinomial logit model and latent class analyses. Five attributes were identified: (1) supervision (2) training (3) monthly financial benefit (4) recognition and (5) employment structure. The most important influence on choice of job was a low monthly financial benefit (US$~2) (β=0.53, 95% CI=0.43 to 0.63), followed by recognition in the form of a performance feedback report (β=0.13, 95% CI=0.07 to 0.20). A large monthly financial benefit (US$~20) was most unappealing to respondents (β=−0.13, 95% CI=−0.23 to −0.03). Latent class analysis identified two groups of CHWs who differed in their willingness to accept either job presented and preferences over specific attributes. Preferences erged based on respondent characteristics including experience, hours’ worked per week and income. CHWs in Malang district, Indonesia, favour a small monthly financial benefit which likely reflects the unique cultural values underpinning the programme and a desire for remuneration that is commensurate with the limited number of hours worked. CHWs also desire enhanced methods of performance feedback and greater structure around training and their rights and responsibilities. Fulfilling these conditions may become increasingly important should CHWs work longer hours.
Publisher: Bentham Science Publishers Ltd.
Date: 10-2007
DOI: 10.2174/187152507782109890
Abstract: Intracellular calcium dynamics play a very important role in mediating contraction and signalling in cardiomyocytes and vascular smooth muscle cells. A number of calcium transporters have been identified that orchestrate a complex process of excitation-contraction coupling and molecular signalling. Despite the variability of the calcium transporters expressed in cardiomyocytes, most calcium channel blockers used therapeutically target the L-type calcium channel and exhibit antihypertensive and/or vasodilating activities. Recently, another calcium pump which is located in the sarcolemma has been shown to mediate cardiac contractility and vascular tone. Interestingly, this sarcolemmal calcium pump (also known as Plasma Membrane Calcium/calmodulin dependent ATPase or PMCA) exerts its function not by altering global calcium concentration, but by mediating signal transduction pathways. This review will discuss recent advances that support the key roles of PMCA as signalling molecule and the potential to target this calcium pump as a novel approach for the treatment of cardiovascular disease.
Publisher: Wiley
Date: 05-2011
DOI: 10.1002/BIOF.149
Abstract: In the heart, Ca(2+) is crucial for the regulation of contraction and intracellular signaling, processes, which are vital to the functioning of the healthy heart. Ca(2+) -activated signaling pathways must function against a background of large, rapid, and tightly regulated changes in intracellular free Ca(2+) concentrations during each contraction and relaxation cycle. This review highlights a number of proteins that regulate signaling Ca(2+) in both normal and pathological conditions including cardiac hypertrophy and heart failure, and discusses how these pathways are not regulated by the marked elevation in free intracellular calcium ([Ca(2+) ](i)) during contraction but require smaller sustained increases in Ca(2+) concentration. In addition, we present published evidence that the pool of Ca(2+) that regulates signaling is compartmentalized into distinct cellular microdomains and is thus distinct from that regulating contraction.
Publisher: Springer Science and Business Media LLC
Date: 29-06-2022
DOI: 10.1186/S12936-022-04228-0
Abstract: Rapid emergence of Plasmodium resistance to anti-malarial drug mainstays has driven a continual effort to discover novel drugs that target different biochemical pathway (s) during infection. Plasma membrane Calcium + 2 ATPase (PMCA4), a novel plasma membrane protein that regulates Calcium levels in various cells, namely red blood cell (RBC), endothelial cell and platelets, represents a new biochemical pathway that may interfere with susceptibility to malaria and/or severe malaria. This study identified several pharmacological inhibitors of PMCA4, namely ATA and Resveratrol, and tested for their anti-malarial activities in vitro and in vivo using the Plasmodium falciparum 3D7 strain, the Plasmodium berghei ANKA strain, and Plasmodium yoelii 17XL strain as model. In vitro propagation of P. falciparum 3D7 strain in the presence of a wide concentration range of the inhibitors revealed that the parasite growth was inhibited in a dose-dependent manner, with IC 50 s at 634 and 0.231 µM, respectively. The results confirmed that both compounds exhibit moderate to potent anti-malarial activities with the strongest parasite growth inhibition shown by resveratrol at 0.231 µM. In vivo models using P. berghei ANKA for experimental cerebral malaria and P. yoelii 17XL for the effect on parasite growth, showed that the highest dose of ATA, 30 mg/kg BW, increased survival of the mice. Likewise, resveratrol inhibited the parasite growth following 4 days intraperitoneal injection at the dose of 100 mg/kg BW. The findings indicate that the PMCA4 of the human host may be a potential target for novel anti-malarials, either as single drug or in combination with the currently available effective anti-malarials.
Publisher: American Society of Hematology
Date: 02-2003
DOI: 10.1182/BLOOD-2002-02-0569
Abstract: The c-fms gene encodes the receptor for macrophage colony-stimulating factor (CSF-1). The gene is expressed selectively in the macrophage and trophoblast cell lineages. Previous studies have indicated that sequences in intron 2 control transcript elongation in tissue-specific and regulated expression of c-fms. In humans, an alternative promoter was implicated in expression of the gene in trophoblasts. We show that in mice, c-fmstranscripts in trophoblasts initiate from multiple points within the 2-kilobase (kb) region flanking the first coding exon. A reporter gene construct containing 3.5 kb of 5′ flanking sequence and the downstream intron 2 directed expression of enhanced green fluorescent protein (EGFP) to both trophoblasts and macrophages. EGFP was detected in trophoblasts from the earliest stage of implantation examined at embryonic day 7.5. During embryonic development, EGFP highlighted the large numbers of c-fms–positive macrophages, including those that originate from the yolk sac. In adult mice, EGFP location was consistent with known F4/80-positive macrophage populations, including Langerhans cells of the skin, and permitted convenient sorting of isolated tissue macrophages from disaggregated tissue. Expression of EGFP in transgenic mice was dependent on intron 2 as no lines with detectable EGFP expression were obtained where either all of intron 2 or a conserved enhancer element FIRE (theFms intronic regulatory element) was removed. We have therefore defined the elements required to generate myeloid- and trophoblast-specific transgenes as well as a model system for the study of mononuclear phagocyte development and function.
Publisher: Springer Science and Business Media LLC
Date: 29-01-2009
DOI: 10.1007/S00424-008-0455-Z
Abstract: The tight regulation of intracellular calcium levels is essential for the normal function of a great many cellular processes, and disruption of this regulation, resulting in sustained increases in intracellular-free calcium, has been associated with numerous diseases. One of the several transporters involved in calcium homeostasis is a P-type ATPase known as the plasma membrane calcium/calmodulin-dependent ATPase (PMCA) which is involved in calcium extrusion from the cytosol to the extracellular compartment. It has long been established that in many cell types, in particular non-excitable cells, the primary role of PMCA is in the bulk transport of intracellular calcium however, its role in excitable cells is less clear. In the heart, for ex le, calcium is essential for contractile function as well as being a key messenger in signal transduction pathways however, the mechanisms by which the cardiomyocyte distinguishes between these roles of calcium remain unclear. It is perhaps the transporters not involved in the contractile cycle (such as PMCA) that are able to carry non-contractile signals. This review will highlight the role of PMCA as a modulator of signal transduction pathways and in particular the role of isoform 4 in the regulation of the nitric oxide signalling pathway.
Publisher: Portland Press Ltd.
Date: 25-10-2007
DOI: 10.1042/BST0350927
Abstract: The PMCA (plasma-membrane Ca2+-ATPase) is a ubiquitously expressed calcium-extruding enzymatic pump important in the control of intracellular calcium concentration. Unlike in non-excitable cells, where PMCA is the only system for calcium extrusion, in excitable cells, such as cardiomyocytes, PMCA has been shown to play only a minor role in calcium homoeostasis compared with the NCX (sodium/calcium exchanger), another system of calcium extrusion. However, increasing evidence points to an important role for PMCA in signal transduction of particular interest in cardiac physiology is the modulation of nNOS (neuronal nitric oxide synthase) by isoform 4b of PMCA. In the present paper, we will discuss recent advances that support a key role for PMCA4 in modulating the nitric oxide signalling pathway in the heart.
Publisher: Elsevier BV
Date: 04-2017
Publisher: Elsevier BV
Date: 10-2022
DOI: 10.1016/J.DSX.2022.102636
Abstract: Opioid use in heart failure (HF) management is controversial, and whether rapid symptomatic relief outweighs the risks of opioid use in HF remains unknown. This study aimed to explore the clinical outcomes of opioid administration in patients with acute or chronic HF. A systematic search for eligible studies was conducted in databases (MEDLINE, Scopus, Web of Science, EBSCO) and registries (ClinicalTrials.gov, WHO Clinical Trial Registry) until June 8, 2022. Odds ratios (ORs) or adjusted OR (aORs) and mean difference (MD) or standardized MD were quantified for binary and continuous outcomes, respectively. Meta-regression was performed using the restricted maximum likelihood method. A total of 20 studies (154,736 participants) were included. In acute HF, opioid use presented a high risk for in-hospital mortality (OR = 2.35 95% confidence interval (CI): 1.03-5.38 I Opioids are not recommended for acute HF management however, they showed an advantage in exercise testing by improving ventilatory efficiency, chemosensitivity, and exercise test duration in stable patients with chronic HF NYHA Class II/III. Nonetheless, larger randomized controlled trials and in idual patient-level data meta-analyses are warranted.
Publisher: MDPI AG
Date: 26-04-2022
DOI: 10.20944/PREPRINTS202204.0233.V1
Abstract: The association between angiotensin-converting enzyme insertion/deletion (ACE I/D) polymorphisms and plasma ACE levels may allow for the optimization of a preventive intervention to reduce cardiovascular morbidity and mortality in the chronic kidney disease (CKD) population. In this study, we aimed to analyze the association between ACE I/D polymorphism and cardiovascular mortality risk among non-hemodialyzed chronic kidney disease patients. This cross-sectional study examined 70 patients of Javanese ethnic origin with stable CKD who did not receive hemodialysis. ACE I/D polymorphisms, plasma ACE levels, atherosclerotic cardiovascular disease (ASCVD) risk, and cardiovascular mortality risk were investigated. As per our findings, the I allele was found to be more frequent (78.6) than the D allele (21.4), and the DD genotype was less frequent than the II genotype (4.3 vs. 61.4). The ACE I/D polymorphism had a significant direct positive effect on plasma ACE levels (path coefficient = 0.302, p = 0.021). Similarly, plasma ACE levels had a direct and significant positive effect on the risk of atherosclerotic cardiovascular disease (path coefficient = 0.410, p = 0.000). Moreover, atherosclerotic cardiovascular disease risk had a significant positive effect on cardiovascular mortality risk (path coefficient = 0.918, p = 0.000). The ACE I/D polymorphism had no direct effect on ASCVD and cardiovascular mortality risk. However, our findings show that the indirect effects of high plasma ACE levels may be a factor in the increased risk of ASCVD and cardiovascular mortality in Javanese CKD patients.
Publisher: MDPI AG
Date: 22-08-2023
Abstract: Cardiomyocyte loss following myocardial infarction cannot be addressed with current clinical therapies. Cell therapy with induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) is a potential approach to replace cardiomyocyte loss. However, engraftment rates in pre-clinical studies have been low, highlighting a need to refine current iPSC-CM technology. In this study, we demonstrated that inducing Yes-associated protein (YAP) by genetic and pharmacological approaches resulted in increased iPSC-CM proliferation and reduced apoptosis in response to oxidative stress. Interestingly, iPSC-CM maturation was differently affected by each strategy, with genetic activation of YAP resulting in a more immature cardiomyocyte-like phenotype not witnessed upon pharmacological YAP activation. Overall, we conclude that YAP activation in iPSC-CMs enhances cell survival and proliferative capacity. Therefore, strategies targeting YAP, or its upstream regulator the Hippo signalling pathway, could potentially be used to improve the efficacy of iPSC-CM technology for use as a future regenerative therapy in myocardial infarction.
Publisher: Wiley
Date: 10-2019
DOI: 10.1111/BPH.14795
Publisher: Wiley
Date: 03-2007
Abstract: The plasma membrane calcium/calmodulin-dependent ATPase (PMCA) is a ubiquitously expressed calcium-extruding enzymatic pump. In the majority of cells the main function of PMCA is as the only system to extrude calcium from the cytosol, however, in the excitable cells of the heart it has only a minor role in the bulk removal of calcium compared to the sodium-calcium exchanger. There is increasing evidence to suggest that PMCA has an additional role as a potential modulator of a number of signal transduction pathways. Of key interest in the heart is the functional interaction between the calcium/calmodulin-dependent enzyme neuronal nitric oxide synthase (nNOS) and isoform 4 of PMCA. Nitric oxide production from nNOS is known to be important in the regulation of excitation-contraction (EC) coupling and subsequently contractility. This article will focus on recent evidence suggesting that PMCA4 has a regulatory role in the nitric oxide signaling pathway in the heart.
Publisher: Springer Science and Business Media LLC
Date: 02-07-2021
DOI: 10.1186/S12936-021-03832-W
Abstract: Recent genome wide analysis studies have identified a strong association between single nucleotide variations within the human ATP2B4 gene and susceptibility to severe malaria. The ATP2B4 gene encodes the plasma membrane calcium ATPase 4 (PMCA4), which is responsible for controlling the physiological level of intracellular calcium in many cell types, including red blood cells (RBCs). It is, therefore, postulated that genetic differences in the activity or expression level of PMCA4 alters intracellular Ca 2+ levels and affects RBC hydration, modulating the invasion and growth of the Plasmodium parasite within its target host cell. In this study the course of three different Plasmodium spp. infections were examined in mice with systemic knockout of Pmca4 expression. Ablation of PMCA4 reduced the size of RBCs and their haemoglobin content but did not affect RBC maturation and reticulocyte count. Surprisingly, knockout of PMCA4 did not significantly alter peripheral parasite burdens or the dynamics of blood stage Plasmodium chabaudi infection or reticulocyte-restricted Plasmodium yoelii infection. Interestingly, although ablation of PMCA4 did not affect peripheral parasite levels during Plasmodium berghei infection, it did promote slight protection against experimental cerebral malaria, associated with a minor reduction in antigen-experienced T cell accumulation in the brain. The finding suggests that PMCA4 may play a minor role in the development of severe malarial complications, but that this appears independent of direct effects on parasite invasion, growth or survival within RBCs.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-2014
DOI: 10.1161/ATVBAHA.114.304363
Abstract: Vascular endothelial growth factor (VEGF) has been identified as a crucial regulator of physiological and pathological angiogenesis. Among the intracellular signaling pathways triggered by VEGF, activation of the calcineurin/nuclear factor of activated T cells (NFAT) signaling axis has emerged as a critical mediator of angiogenic processes. We and others previously reported a novel role for the plasma membrane calcium ATPase (PMCA) as an endogenous inhibitor of the calcineurin/NFAT pathway, via interaction with calcineurin, in cardiomyocytes and breast cancer cells. However, the functional significance of the PMCA/calcineurin interaction in endothelial pathophysiology has not been addressed thus far. Using in vitro and in vivo assays, we here demonstrate that the interaction between PMCA4 and calcineurin in VEGF-stimulated endothelial cells leads to downregulation of the calcineurin/NFAT pathway and to a significant reduction in the subsequent expression of the NFAT-dependent, VEGF-activated, proangiogenic genes RCAN1.4 and Cox-2 . PMCA4-dependent inhibition of calcineurin signaling translates into a reduction in endothelial cell motility and blood vessel formation that ultimately impairs in vivo angiogenesis by VEGF. Given the importance of the calcineurin/NFAT pathway in the regulation of pathological angiogenesis, targeted modulation of PMCA4 functionality might open novel therapeutic avenues to promote or attenuate new vessel formation in diseases that occur with angiogenesis.
Publisher: Elsevier BV
Date: 03-2023
Publisher: Springer Science and Business Media LLC
Date: 17-05-2021
DOI: 10.1186/S40246-021-00330-7
Abstract: Coronavirus disease 2019 (COVID-19) is a global health problem that causes millions of deaths worldwide. The clinical manifestation of COVID-19 widely varies from asymptomatic infection to severe pneumonia and systemic inflammatory disease. It is thought that host genetic variability may affect the host’s response to the virus infection and thus cause severity of the disease. The SARS-CoV-2 virus requires interaction with its receptor complex in the host cells before infection. The transmembrane protease serine 2 (TMPRSS2) has been identified as one of the key molecules involved in SARS-CoV-2 virus receptor binding and cell invasion. Therefore, in this study, we investigated the correlation between a genetic variant within the human TMPRSS2 gene and COVID-19 severity and viral load. We genotyped 95 patients with COVID-19 hospitalised in Dr Soetomo General Hospital and Indrapura Field Hospital (Surabaya, Indonesia) for the TMPRSS2 p.Val160Met polymorphism. Polymorphism was detected using a TaqMan assay. We then analysed the association between the presence of the genetic variant and disease severity and viral load. We did not observe any correlation between the presence of TMPRSS2 genetic variant and the severity of the disease. However, we identified a significant association between the p.Val160Met polymorphism and the SARS-CoV-2 viral load, as estimated by the Ct value of the diagnostic nucleic acid lification test. Furthermore, we observed a trend of association between the presence of the C allele and the mortality rate in patients with severe COVID-19. Our data indicate a possible association between TMPRSS2 p.Val160Met polymorphism and SARS-CoV-2 infectivity and the outcome of COVID-19.
Publisher: MDPI AG
Date: 05-09-2022
Abstract: Background and Objectives: Besides corticosteroids, clinicians found that vestibular rehabilitation therapy (VRT) has a potential effect on vestibular neuritis (VN) improvement. This study aimed to investigate the efficacy of both corticosteroid therapy (CT) compared to VRT, and each group compared to their combination (CT vs. (CT+VRT) and VRT vs. (CT + VRT). Materials and Methods: Systematic searches were performed in PubMed, CINAHL, and Scopus for randomized controlled trials (RCTs) reporting the administration of at least CT and VRT for VN. The outcome of interest was VN’s subjective and objective improvement parameters. Results: Four RCTs involving a total of 182 patients with VN were eligible for systematic review and meta-analysis. The weighted mean difference (WMD) of canal paresis (objective parameter) in the CT group is significantly lower than in the VRT group after a 1 month follow-up (8.31 95% CI: 0.29, −16.32 p = 0.04 fixed effect). Meanwhile, the WMD of Dizziness Handicap Inventory (DHI) (subjective parameter) in the VRT group is significantly lower than in the CT group after a 1 month follow-up (−3.95 95% CI: −7.69, −0.21 p = 0.04 fixed effect). Similarly, the WMD of DHI in the combination group (CT+VRT) is significantly lower than in the CT group after a 3 month follow-up (3.15 95% CI: 1.50, 4.80 p = 0.0002 fixed effect). However, there is no significant difference in all outcomes after 12 months of follow-ups in all groups (CT vs. VRT, CT vs. combination, and VRT vs. combination). Conclusions: This study indicates that CT enhances the earlier canal paresis improvement, as the objective parameter, while VRT gives the earlier DHI score improvement, as the subjective parameter. However, their long-term efficacy does not appear to be different. VRT has to be offered as the primary option for patients with VN, and corticosteroids can be added to provide better recovery in the absence of its contraindication. However, whether to choose VRT, CT, or its combination should be tailored to the patient’s condition. Future studies are still needed to revisit this issue, due to the small number of trials in this field. (PROSPERO ID: CRD42021220615).
Publisher: Springer Science and Business Media LLC
Date: 08-09-2017
DOI: 10.1038/S41467-017-00664-8
Abstract: The prevalence of cardiomyopathy from metabolic stress has increased dramatically however, its molecular mechanisms remain elusive. Here, we show that extracellular signal-regulated protein kinase 5 (Erk5) is lost in the hearts of obese/diabetic animal models and that cardiac-specific deletion of Erk5 in mice (Erk5-CKO) leads to d ened cardiac contractility and mitochondrial abnormalities with repressed fuel oxidation and oxidative damage upon high fat diet (HFD). Erk5 regulation of peroxisome proliferator-activated receptor γ co-activator-1α (Pgc-1α) is critical for cardiac mitochondrial functions. More specifically, we show that Gp91phox activation of calpain-1 degrades Erk5 in free fatty acid (FFA)-stressed cardiomyocytes, whereas the prevention of Erk5 loss by blocking Gp91phox or calpain-1 rescues mitochondrial functions. Similarly, adeno-associated virus 9 (AAV9)-mediated restoration of Erk5 expression in Erk5-CKO hearts prevents cardiomyopathy. These findings suggest that maintaining Erk5 integrity has therapeutic potential for treating metabolic stress-induced cardiomyopathy.
Publisher: Springer Science and Business Media LLC
Date: 16-07-2013
DOI: 10.1007/S10741-013-9390-Y
Abstract: Pacing-induced ventricular dysfunction and pacing-induced cardiomyopathy (PiCMP) are recognized complications of chronic right ventricular pacing. Alterations in myocardial perfusion and sympathetic innervation contribute to the development of pacing-induced heart disease. However, it is unlikely that these are the only processes involved. Matrix metalloproteinases (MMPs) are proteolytic enzymes that degrade the collagenous extracellular matrix and play a central role in left ventricular remodelling during the development of heart failure. While the pathophysiological mechanisms and altered MMP expression that occur in chronic pressure overload, ischaemic and non-ischaemic dilated cardiomyopathy have been defined, those that occur in the clinical setting of pacing-induced ventricular dysfunction and PiCMP have not been reported. Here we review the clinical epidemiology of pacing-induced ventricular dysfunction and discuss how data derived from animal models provide insight into how changes in MMP expression and function contribute to the development of PiCMP. The review concludes by exploring pacing strategies that may be used to prevent pacing-induced ventricular dysfunction.
Publisher: Elsevier BV
Date: 10-2016
Publisher: Elsevier BV
Date: 06-2022
Publisher: MDPI AG
Date: 25-03-1970
DOI: 10.3390/JPM12071122
Abstract: Interleukin-6 (IL-6) has been identified as an important pro-inflammatory factor involved in mediating the severity of chronic kidney disease (CKD). This study sought to determine the effect of plasma IL-6 levels on atherosclerotic cardiovascular disease (ASCVD) and cardiovascular mortality risk scores in Javanese CKD patients. We also analyzed the frequency of IL-6 G174C single nucleotide polymorphism (SNP) in the population. This study was a cross-sectional study involving seventy-three patients of Javanese ethnic origin with stable chronic kidney disease. We assessed the ASCVD risk score, cardiovascular mortality score, genotyping of IL-6 G174C SNP, and plasma IL-6 levels in these patients. The genotype distribution and allele frequencies of the IL-6 G174C SNP were predominated by the G genotype/allele (GG: 97.26%, GC: 1.37%, CC: 1.37%, G-allele: 97.95%, and C-allele: 2.05%). Despite the fact that plasma IL-6 levels did not directly affect cardiovascular mortality risk, further analysis revealed its direct effect on the ASCVD risk score (path coefficient = 0.184, p = 0.043, 95% CI = 0.018–0.380), which in turn affected cardiovascular mortality risk (path coefficient = 0.851, p = .01, 95% CI = 0.714–0.925). In conclusion, plasma IL-6 levels play important roles on ASCVD risk and cardiovascular mortality risk in Javanese patients with CKD.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 25-06-2021
DOI: 10.1161/CIRCRESAHA.119.316386
Abstract: Athletes present with atrioventricular node dysfunction manifesting as atrioventricular block. This can necessitate electronic pacemaker implantation, known to be more frequent in athletes with a long training history. Atrioventricular block in athletes is attributed to high vagal tone. Here, we investigated the alternative hypothesis that electrical remodeling of the atrioventricular node is responsible. Radiotelemetry ECG data and atrioventricular node biopsies were collected in sedentary and trained Standardbred racehorses, a large-animal model of the athlete’s heart. Trained horses presented with longer PR intervals (that persisted under complete autonomic block) versus sedentary horses, concomitant with reduced expression of key ion channels involved in atrioventricular node conduction: L-type Ca 2+ channel subunit Ca V 1.2 and HCN4 (hyperpolarization-activated cyclic nucleotide-gated channel 4). Atrioventricular node electrophysiology was explored further in mice prolongation of the PR interval (in vivo and ex vivo), Wenckebach cycle length, and atrioventricular node refractory period were observed in mice trained by swimming versus sedentary mice. Transcriptional profiling in laser-capture microdissected atrioventricular node revealed striking reduction in pacemaking ion channels in trained mice, translating into protein downregulation of Ca V 1.2 and HCN4. Correspondingly, patch-cl recordings in isolated atrioventricular node myocytes demonstrated a training-induced reduction in I Ca, L and I f density that likely contributed to the observed lower frequency of action potential firing in trained cohorts. MicroRNA (miR) profiling and in vitro studies revealed miR-211-5p and miR-432 as direct regulators of Ca V 1.2 and HCN4. In vivo miRs suppression or detraining restored training-induced PR prolongation and ion channel remodeling. Training-induced atrioventricular node dysfunction is underscored by likely miR-mediated transcriptional remodeling that translates into reduced current density of key ionic currents involved in impulse generation and conduction. We conclude that electrical remodeling is a key mechanism underlying atrioventricular block in athletes.
Publisher: Frontiers Media SA
Date: 30-10-2020
Publisher: Elsevier BV
Date: 11-2009
DOI: 10.1016/J.TCM.2010.02.008
Abstract: The close relationship between signaling pathways regulating tumor growth and cardiac hypertrophy has attracted considerable interest. Although the involvement of proto-oncogenes in positively modulating myocardial hypertrophy has long been recognized, little is known about factors that counterregulate them. In this article, we review the novel tumor suppressor Ras-association domain family protein isoform 1A (RASSF1A), which strongly inhibits the prohypertrophic Ras-Raf1-ERK1/2 pathway in the heart. RASSF1A interacts with a number of important signaling molecules regulating cell growth, survival, and apoptosis therefore, it serves as a key adaptor molecule that integrates the upstream stimuli and transduces them to the selective downstream effectors.
Publisher: American Medical Association (AMA)
Date: 10-2019
Publisher: MDPI AG
Date: 24-09-2020
DOI: 10.3390/MOLECULES25194381
Abstract: Diabetes mellitus (DM) is one of the major causes of death in the world. There are two types of DM—type 1 DM and type 2 DM. Type 1 DM can only be treated by insulin injection whereas type 2 DM is commonly treated using anti-hyperglycemic agents. Despite its effectiveness in controlling blood glucose level, this therapeutic approach is not able to reduce the decline in the number of functional pancreatic β cells. MST1 is a strong pro-apoptotic kinase that is expressed in pancreatic β cells. It induces β cell death and impairs insulin secretion. Recently, a potent and specific inhibitor for MST1, called XMU-MP-1, was identified and characterized. We hypothesized that treatment with XMU-MP-1 would produce beneficial effects by improving the survival and function of the pancreatic β cells. We used INS-1 cells and STZ-induced diabetic mice as in vitro and in vivo models to test the effect of XMU-MP-1 treatment. We found that XMU-MP-1 inhibited MST1/2 activity in INS-1 cells. Moreover, treatment with XMU-MP-1 produced a beneficial effect in improving glucose tolerance in the STZ-induced diabetic mouse model. Histological analysis indicated that XMU-MP-1 increased the number of pancreatic β cells and enhanced Langerhans islet area in the severe diabetic mice. Overall, this study showed that MST1 could become a promising therapeutic target for diabetes mellitus.
Publisher: Elsevier BV
Date: 08-2017
DOI: 10.1016/J.YJMCC.2017.07.001
Abstract: Ischaemic cardiovascular disease is a major cause of morbidity and mortality worldwide. Despite promising results from pre-clinical animal models, VEGF-based strategies for therapeutic angiogenesis have yet to achieve successful reperfusion of ischaemic tissues in patients. Failure to restore efficient VEGF activity in the ischaemic organ remains a major problem in current pro-angiogenic therapeutic approaches. Plasma membrane calcium ATPase 4 (PMCA4) negatively regulates VEGF-activated angiogenesis via inhibition of the calcineurin/NFAT signalling pathway. PMCA4 activity is inhibited by the small molecule aurintricarboxylic acid (ATA). We hypothesize that inhibition of PMCA4 with ATA might enhance VEGF-induced angiogenesis. We show that inhibition of PMCA4 with ATA in endothelial cells triggers a marked increase in VEGF-activated calcineurin/NFAT signalling that translates into a strong increase in endothelial cell motility and blood vessel formation. ATA enhances VEGF-induced calcineurin signalling by disrupting the interaction between PMCA4 and calcineurin at the endothelial-cell membrane. ATA concentrations at the nanomolar range, that efficiently inhibit PMCA4, had no deleterious effect on endothelial-cell viability or zebrafish embryonic development. However, high ATA concentrations at the micromolar level impaired endothelial cell viability and tubular morphogenesis, and were associated with toxicity in zebrafish embryos. In mice undergoing experimentally-induced hindlimb ischaemia, ATA treatment significantly increased the reperfusion of post-ischaemic limbs. Our study provides evidence for the therapeutic potential of targeting PMCA4 to improve VEGF-based pro-angiogenic interventions. This goal will require the development of refined, highly selective versions of ATA, or the identification of novel PMCA4 inhibitors.
Publisher: Elsevier BV
Date: 08-2006
Publisher: Elsevier BV
Date: 10-2013
DOI: 10.1016/J.YJMCC.2013.07.007
Abstract: Isoform 4 of the plasma membrane calcium/calmodulin dependent ATPase (PMCA4) has recently emerged as an important regulator of several key pathophysiological processes in the heart, such as contractility and hypertrophy. However, direct monitoring of PMCA4 activity and assessment of calcium dynamics in its vicinity in cardiomyocytes are difficult due to the lack of molecular tools. In this study, we developed novel calcium fluorescent indicators by fusing the GCaMP2 calcium sensor to the N-terminus of PMCA4 to generate the PMCA4-GCaMP2 fusion molecule. We also identified a novel specific inhibitor of PMCA4, which might be useful for studying the role of this molecule in cardiomyocytes and other cell types. Using an adenoviral system we successfully expressed PMCA4-GCaMP2 in both neonatal and adult rat cardiomyocytes. This fusion molecule was correctly targeted to the plasma membrane and co-localised with caveolin-3. It could monitor signal oscillations in electrically stimulated cardiomyocytes. The PMCA4-GCaMP2 generated a higher signal litude and faster signal decay rate compared to a mutant inactive PMCA4(mut)GCaMP2 fusion protein, in electrically stimulated neonatal and adult rat cardiomyocytes. A small molecule library screen enabled us to identify a novel selective inhibitor for PMCA4, which we found to reduce signal litude of PMCA4-GCaMP2 and prolong the time of signal decay (Tau) to a level comparable with the signal generated by PMCA4(mut)GCaMP2. In addition, PMCA4-GCaMP2 but not the mutant form produced an enhanced signal in response to β-adrenergic stimulation. Together, the PMCA4-GCaMP2 and PMCA4(mut)GCaMP2 demonstrate calcium dynamics in the vicinity of the pump under active or inactive conditions, respectively. In summary, the PMCA4-GCaMP2 together with the novel specific inhibitor provides new means with which to monitor calcium dynamics in the vicinity of a calcium transporter in cardiomyocytes and may become a useful tool to further study the biological functions of PMCA4. In addition, similar approaches could be useful for studying the activity of other calcium transporters during excitation-contraction coupling in the heart.
Publisher: Elsevier BV
Date: 12-2019
Publisher: Frontiers Media SA
Date: 26-01-2023
DOI: 10.3389/FPUBH.2022.1030695
Abstract: Vaccine hesitancy could undermine efforts to reduce incidence of coronavirus disease 2019 (COVID-19). Understanding COVID-19 vaccine hesitancy is crucial to tailoring strategies to increase vaccination acceptance. This study aims to investigate the prevalence of and the reasons for COVID-19 vaccine hesitancy in Malang District, Indonesia. Data come from a cross-sectional study among in iduals aged 17-85 years old (N = 3,014). Multivariate ordered logistic regression was used to identify factors associated with postponing or refusing COVID-19 vaccines. The Oxford COVID-19 vaccine hesitancy scale was used to measure vaccine hesitancy. A wide range of reasons for hesitancy, including coronavirus vaccine confidence and complacency, vaccination knowledge, trust and attitude in health workers and health providers, coronavirus conspiracy, anger reaction and need for chaos, populist views, lifestyle, and religious influence, was examined. The results show that 60.2% of the respondents were hesitant to receive the COVID-19 vaccine. Low confidence and complacency beliefs about the vaccine (OR = 1.229, 95% CI = 1.195–1.264) and more general sources of mistrust within the community, particularly regarding health providers (OR = 1.064, 95% CI = 1.026–1.102) and vaccine developers (OR = 1.054, 95% CI = 1.027–1.082), are associated with higher levels of COVID-19 vaccine hesitancy. Vaccine hesitancy is also associated with anger reactions (OR = 1.019, 95% CI = 0.998–1.040), need for chaos (OR = 1.044, 95% CI = 1.022–1.067), and populist views (OR = 1.028, 95% CI = 1.00–1.056). The findings were adjusted for socio-demographic factors, including age, sex, education, marital status, working status, type of family, household income, religious beliefs, and residency. The results suggest the need for an effective health promotion program to improve community knowledge of the COVID-19 vaccine, while effective strategies to tackle “infodemics” are needed to address hesitancy during a new vaccine introduction program.
Location: United Kingdom of Great Britain and Northern Ireland
Start Date: 2017
End Date: 2020
Funder: Medical Research Council
View Funded ActivityStart Date: 2015
End Date: 2020
Funder: Economic and Social Research Council
View Funded ActivityStart Date: 2013
End Date: 2016
Funder: British Heart Foundation
View Funded ActivityStart Date: 2017
End Date: 2019
Funder: British Heart Foundation
View Funded ActivityStart Date: 2017
End Date: 2019
Funder: British Heart Foundation
View Funded Activity