ORCID Profile
0000-0001-8776-5820
Current Organisation
University Medical Center Hamburg-Eppendorf
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: EMBO
Date: 03-11-2019
Publisher: MDPI AG
Date: 02-09-2022
Abstract: Genetic variants in α-actinin-2 (ACTN2) are associated with several forms of (cardio)myopathy. We previously reported a heterozygous missense (c.740C T) ACTN2 gene variant, associated with hypertrophic cardiomyopathy, and characterized by an electro-mechanical phenotype in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). Here, we created with CRISPR/Cas9 genetic tools two heterozygous functional knock-out hiPSC lines with a second wild-type (ACTN2wt) and missense ACTN2 (ACTN2mut) allele, respectively. We evaluated their impact on cardiomyocyte structure and function, using a combination of different technologies, including immunofluorescence and live cell imaging, RNA-seq, and mass spectrometry. This study showed that ACTN2mut presents a higher percentage of multinucleation, protein aggregation, hypertrophy, myofibrillar disarray, and activation of both the ubiquitin-proteasome system and the autophagy-lysosomal pathway as compared to ACTN2wt in 2D-cultured hiPSC-CMs. Furthermore, the expression of ACTN2mut was associated with a marked reduction of sarcomere-associated protein levels in 2D-cultured hiPSC-CMs and force impairment in engineered heart tissues. In conclusion, our study highlights the activation of proteolytic systems in ACTN2mut hiPSC-CMs likely to cope with ACTN2 aggregation and therefore directs towards proteopathy as an additional cellular pathology caused by this ACTN2 variant, which may contribute to human ACTN2-associated cardiomyopathies.
Publisher: Oxford University Press (OUP)
Date: 06-01-2022
DOI: 10.1093/CVR/CVAB370
Abstract: Cardiovascular diseases represent a major cause of morbidity and mortality, necessitating research to improve diagnostics, and to discover and test novel preventive and curative therapies, all of which warrant experimental models that recapitulate human disease. The translation of basic science results to clinical practice is a challenging task, in particular for complex conditions such as cardiovascular diseases, which often result from multiple risk factors and comorbidities. This difficulty might lead some in iduals to question the value of animal research, citing the translational ‘valley of death’, which largely reflects the fact that studies in rodents are difficult to translate to humans. This is also influenced by the fact that new, human-derived in vitro models can recapitulate aspects of disease processes. However, it would be a mistake to think that animal models do not represent a vital step in the translational pathway as they do provide important pathophysiological insights into disease mechanisms particularly on an organ and systemic level. While stem cell-derived human models have the potential to become key in testing toxicity and effectiveness of new drugs, we need to be realistic, and carefully validate all new human-like disease models. In this position paper, we highlight recent advances in trying to reduce the number of animals for cardiovascular research ranging from stem cell-derived models to in situ modelling of heart properties, bioinformatic models based on large datasets, and state-of-the-art animal models, which show clinically relevant characteristics observed in patients with a cardiovascular disease. We aim to provide a guide to help researchers in their experimental design to translate bench findings to clinical routine taking the replacement, reduction, and refinement (3R) as a guiding concept.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 2021
DOI: 10.1161/CIRCHEARTFAILURE.120.007022
Abstract: Hypertrophic cardiomyopathy (HCM) is the most common genetic heart disease. While ≈50% of patients with HCM carry a sarcomere gene mutation (sarcomere mutation-positive, HCM SMP ), the genetic background is unknown in the other half of the patients (sarcomere mutation-negative, HCM SMN ). Genotype-specific differences have been reported in cardiac function. Moreover, HCM SMN patients have later disease onset and a better prognosis than HCM SMP patients. To define if genotype-specific derailments at the protein level may explain the heterogeneity in disease development, we performed a proteomic analysis in cardiac tissue from a clinically well-phenotyped HCM patient group. A proteomics screen was performed in cardiac tissue from 39 HCM SMP patients, 11HCM SMN patients, and 8 nonfailing controls. Patients with HCM had obstructive cardiomyopathy with left ventricular outflow tract obstruction and diastolic dysfunction. A novel MYBPC3 2373insG mouse model was used to confirm functional relevance of our proteomic findings. In all HCM patient s les, we found lower levels of metabolic pathway proteins and higher levels of extracellular matrix proteins. Levels of total and detyrosinated α-tubulin were markedly higher in HCM SMP than in HCM SMN and controls. Higher tubulin detyrosination was also found in 2 unrelated MYBPC3 mouse models and its inhibition with parthenolide normalized contraction and relaxation time of isolated cardiomyocytes. Our findings indicate that microtubules and especially its detyrosination contribute to the pathomechanism of patients with HCM SMP . This is of clinical importance since it represents a potential treatment target to improve cardiac function in patients with HCM SMP , whereas a beneficial effect may be limited in patients with HCM SMN .
No related grants have been discovered for Lucie Carrier.