ORCID Profile
0000-0002-7683-9422
Current Organisations
St George's, University of London
,
University of Manchester
,
University of Leeds
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: Wiley
Date: 04-2008
Publisher: Springer Science and Business Media LLC
Date: 02-2009
Publisher: Cold Spring Harbor Laboratory
Date: 04-08-2023
DOI: 10.1101/2023.08.01.23292554
Abstract: Generalised Lymphatic Dysplasia (GLD) is characterised by widespread lymphoedema, with at least one of the following: fetal hydrops, intestinal or pulmonary lymphangiectasia, pleural effusions, pericardial effusions and ascites. Satisfactory medical therapies are lacking. A genetic association has been identified that prevents expression or surface trafficking of PIEZO1, a subunit of mechanically activated calcium-permeable channels. However, PIEZO1 is a large and highly polymorphic gene and interpretation of variants identified in this gene can be challenging. PIEZO1- related GLD with non-immune fetal hydrops is autosomal recessive, however, heterozygous variants in PIEZO1 (often gain-of-function) causing Dehydrated Hereditary Stomatocytosis (DHS) (a relative mild anaemia), may also present with perinatal non-immune hydrops (not caused by anaemia). Here we sought to develop methods to confirm pathogenicity of missense variants of uncertain significance in PIEZO1 , to gain deeper understanding and pharmacological solutions. Four novel GLD-associated missense variants in PIEZO1 are identified that express and surface localise as full-length protein but with reduced or abolished mechanically activated channel function. Yoda1, a small-molecule agonist, functionally rescues the channels and their physiological regulation by mechanical force and hypo-osmolality. The GLD-associated variants mediate intracellular calcium release as well as calcium entry, suggesting two pools of channels and opportunity for increased rescue through access to the intracellular pool. New Yoda1 analogues are also identified that improve rescue. The functional assays have assisted the interpretation of the variants of uncertain significance as the data suggest loss of PIEZO1 force sensing as a cause of the GLD observed in the patients. The potential to pharmacologically overcome the loss of force sensing was demonstrated and supports the concept of stimulation of PIEZO1 with an agonist to address wide-ranging problems of lymphatic insufficiency. Previously unrecognised variants in PIEZO1 that associate with GLD are identified and characterised and pathogenicity confirmed The variants encode single amino acid changes that inhibit PIEZO1 channel activation by physiological mechanical forces A small-molecule agonist rescues the channels and their physiological regulation Variants are partly intracellular, suggesting an opportunity for improved rescue through the use of intracellular-acting agonists New agonists are identified that improve rescue, suggesting routes to medical therapies for GLD and potentially other disorders of lymphatic insufficiency
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-10-2008
DOI: 10.1161/CIRCRESAHA.108.182931
Abstract: Stromal interaction molecule 1 (STIM1) is a predicted single membrane–spanning protein involved in store-operated calcium entry and interacting with ion channels including TRPC1. Here, we focus on endogenous STIM1 of modulated vascular smooth muscle cells, which exhibited a nonselective cationic current in response to store depletion despite strong buffering of intracellular calcium at the physiological concentration. STIM1 mRNA and protein were detected and suppressed by specific short interfering RNA. Calcium entry evoked by store depletion was partially inhibited by STIM1 short interfering RNA, whereas calcium release was unaffected. STIM1 short interfering RNA suppressed cell migration but not proliferation. Antibody that specifically bound STIM1 revealed constitutive extracellular N terminus of STIM1 and extracellular application of the antibody caused fast inhibition of the current evoked by store depletion. The antibody also inhibited calcium entry and cell migration but not proliferation. STIM1 interacted with TRPC1, and TRPC1 contributed partially to calcium entry and cationic current. However, the underlying processes could not be explained only by a STIM1-TRPC1 partnership because extracellular TRPC1 antibody suppressed cationic current only in a fraction of cells, TRPC1-containing channels were important for cell proliferation as well as migration, and cell surface localization studies revealed TRPC1 alone, as well as with STIM1. The data suggest a complex situation in which there is not only plasma membrane–spanning STIM1 that is important for cell migration and TRPC1-independent store-operated cationic current but also TRPC1-STIM1 interaction, a TRPC1-dependent component of store-operated current, and STIM1-independent TRPC1 linked to cell proliferation.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-2010
DOI: 10.1161/ATVBAHA.110.205666
Abstract: Objective— To determine whether calcium-permeable channels are targets for the oxidized phospholipids: 1-palmitoyl-2-glutaroyl-phosphatidylcholine (PGPC) and 1-palmitoyl-2-oxovaleroyl-phosphatidylcholine (POVPC). Methods and Results— Oxidized phospholipids are key factors in inflammation and associated diseases, including atherosclerosis however, the initial reception mechanisms for cellular responses to the factors are poorly understood. Low micromolar concentrations of PGPC and POVPC evoked increases in intracellular calcium in human embryonic kidney 293 cells that overexpressed human transient receptor potential canonical 5 (TRPC5) but not human TRP melastatin (TRPM) 2 or 3. The results of electrophysiological experiments confirmed stimulation of TRPC5. To investigate relevance to endogenous channels, we studied proliferating vascular smooth muscle cells from patients undergoing coronary artery bypass surgery. PGPC and POVPC elicited calcium entry that was inhibited by anti-TRPC5 or anti-TRPC1 antibodies or dominant-negative mutant TRPC5. Calcium release did not occur. The effect was functionally relevant because it enhanced cell migration. The actions of PGPC and POVPC depended on G i/o proteins but not on previously identified G protein–coupled receptors for oxidized phospholipids. Conclusion— Stimulation of calcium-permeable TRPC5-containing channels may be an early event in cellular responses to oxidized phospholipids that couples to cell migration and requires an unidentified G protein–coupled receptor.
Publisher: American Society for Pharmacology & Experimental Therapeutics (ASPET)
Date: 15-03-2011
Publisher: Springer Science and Business Media LLC
Date: 2008
DOI: 10.1038/NATURE06414
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 14-05-2010
DOI: 10.1161/CIRCRESAHA.110.219329
Abstract: Rationale : Transient receptor potential melastatin (TRPM)3 is a calcium-permeable ion channel activated by the neurosteroid pregnenolone sulfate and positively coupled to insulin secretion in β cells. Although vascular TRPM3 mRNA has been reported, there is no knowledge of TRPM3 protein or its regulation and function in the cardiovascular system. Objective : To determine the relevance and regulation of TRPM3 in vascular biology. Methods and Results : TRPM3 expression was detected at mRNA and protein levels in contractile and proliferating vascular smooth muscle cells. Calcium entry evoked by pregnenolone sulfate or sphingosine was suppressed by TRPM3 blocking antibody or knock-down of TRPM3 by RNA interference. Low-level constitutive TRPM3 activity was also detected. In proliferating cells, channel activity was coupled negatively to interleukin-6 secretion via a calcium-dependent mechanism. In freshly isolated aorta, TRPM3 positively modulated contractile responses independently of L-type calcium channels. Concentrations of pregnenolone sulfate required to evoke responses were higher than the known plasma concentrations of the steroids, leading to a screen for other stimulators. β-Cyclodextrin was one of few stimulators of TRPM3, revealing the channels to be partially suppressed by endogenous cholesterol, the precursor of pregnenolone. Elevation of cholesterol further suppressed channel activity and loading with cholesterol to generate foam cells precluded observation of TRPM3 activity. Conclusions : The data suggest functional relevance of TRPM3 in contractile and proliferating phenotypes of vascular smooth muscle cells, significance of constitutive channel activity, regulation by cholesterol, and potential value of pregnenolone sulfate in therapeutic vascular modulation.
Publisher: Wiley
Date: 10-2008
DOI: 10.1038/BJP.2008.283
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for David Beech.