Viola 2016 JACC: Basic to Translational Science: Difference between revisions
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|authors=Viola HM, Johnstone VPA, Szappanos HC, Richman TR, Tsoutsman T, Filipovska A, Semsarian C, Seidman JG, Seidman CE, Hool LC | |authors=Viola HM, Johnstone VPA, Szappanos HC, Richman TR, Tsoutsman T, Filipovska A, Semsarian C, Seidman JG, Seidman CE, Hool LC | ||
|year=2016 | |year=2016 | ||
|journal=JACC | |journal=JACC Basic Transl Sci | ||
|abstract='''Highlights''' | |abstract='''Highlights''' | ||
Latest revision as of 15:42, 12 March 2019
Viola HM, Johnstone VPA, Szappanos HC, Richman TR, Tsoutsman T, Filipovska A, Semsarian C, Seidman JG, Seidman CE, Hool LC (2016) The role of the L-type Ca2+ channel in altered metabolic activity in a murine model of hypertrophic cardiomyopathy. JACC: Basic to Translational Science 1: 61โ72. |
Viola HM, Johnstone VPA, Szappanos HC, Richman TR, Tsoutsman T, Filipovska A, Semsarian C, Seidman JG, Seidman CE, Hool LC (2016) JACC Basic Transl Sci
Abstract: Highlights
Heterozygous mice (ฮฑMHC403/+) expressing the human hypertrophic cardiomyopathy (HCM) disease causing mutation Arg403Gln exhibit cardinal features of HCM. This study investigated the role of L-type Ca2+ channel (ICa-L) in regulating mitochondrial function in Arg403Gln (ฮฑMHC403/+) mice. Activation of ICa-L in ฮฑMHC403/+ mice caused a significantly greater increase in mitochondrial membrane potential and metabolic activity when compared to wild-type mice. Increases in mitochondrial membrane potential and metabolic activity were attenuated with ICa-L antagonists and when F-actin or ฮฒ-tubulin were depolymerized. ICa-L antagonists may be effective in reducing the cardiomyopathy in HCM by altering metabolic activity.
Summary
Heterozygous mice (ฮฑMHC403/+) expressing the human disease-causing mutation Arg403Gln exhibit cardinal features of hypertrophic cardiomyopathy (HCM) including hypertrophy, myocyte disarray, and increased myocardial fibrosis. Treatment of ฮฑMHC403/+ mice with the L-type calcium channel (ICa-L) antagonist diltiazem has been shown to decrease left ventricular anterior wall thickness, cardiac myocyte hypertrophy, disarray, and fibrosis. However, the role of the ICa-L in the development of HCM is not known. In addition to maintaining cardiac excitation and contraction in myocytes, the ICa-L also regulates mitochondrial function through transmission of movement of ICa-L via cytoskeletal proteins to mitochondrial voltage-dependent anion channel. Here, the authors investigated the role of ICa-L in regulating mitochondrial function in ฮฑMHC403/+ mice. Whole-cell patch clamp studies showed that ICa-L current inactivation kinetics were significantly increased in ฮฑMHC403/+ cardiac myocytes, but that current density and channel expression were similar to wild-type cardiac myocytes. Activation of ICa-L caused a significantly greater increase in mitochondrial membrane potential and metabolic activity in ฮฑMHC403/+. These increases were attenuated with ICa-L antagonists and following F-actin or ฮฒ-tubulin depolymerization. The authors observed increased levels of fibroblast growth factor-21 in ฮฑMHC403/+ mice, and altered mitochondrial DNA copy number consistent with altered mitochondrial activity and the development of cardiomyopathy. These studies suggest that the Arg403Gln mutation leads to altered functional communication between ICa-L and mitochondria that is associated with increased metabolic activity, which may contribute to the development of cardiomyopathy. ICa-L antagonists may be effective in reducing the cardiomyopathy in HCM by altering metabolic activity. โข Keywords: Calcium, Cardiomyopathy, L-type calcium channel, Mitochondria
โข O2k-Network Lab: AU Perth Filipovska A
Labels: MiParea: Respiration, Genetic knockout;overexpression
Pathology: Myopathy
Organism: Mouse Tissue;cell: Heart Preparation: Isolated mitochondria
Coupling state: OXPHOS
Pathway: N, S, CIV
HRR: Oxygraph-2k
2016-05