TY - JOUR
T1 - The L-type calcium channel inhibitor diltiazem prevents cardiomyopathy in a mouse model
AU - Semsarian, Christopher
AU - Ahmad, Imran
AU - Giewat, Michael
AU - Georgakopoulos, Dimitrios
AU - Schmitt, Joachim P.
AU - McConnell, Bradley K.
AU - Reiken, Steven
AU - Mende, Ulrike
AU - Marks, Andrew R.
AU - Kass, David A.
AU - Seidman, Christine E.
AU - Seidman, J. G.
PY - 2002
Y1 - 2002
N2 - Dominant mutations in sarcomere protein genes cause hypertrophic cardiomyopathy, an inherited human disorder with increased ventricular wall thickness, myocyte hypertrophy, and disarray. To understand the early consequences of mutant sarcomere proteins, we have studied mice (designated αMHC403/+) bearing an Arg403Gln missense mutation in the α cardiac myosin heavy chain. We demonstrate that Ca2+ is reduced in the sarcoplasmic reticulum of αMHC403/+ mice, and levels of the sarcoplasmic reticulum Ca2+-binding protein calsequestrin are diminished in advance of changes in cardiac histology or morphology. Further evidence for dysregulation of sarcoplasmic reticulum Ca2+ in these animals is seen in their decreased expression of the ryanodine receptor Ca2+-release channel and its associated membrane proteins and in an increase in ryanodine receptor phosphorylation. Early administration of the L-type Ca2+ channel inhibitor diltiazem restores normal levels of these sarcoplasmic reticular proteins and prevents the development of pathology in αMHC403/+ mice. We conclude that disruption of sarcoplasmic reticulum Ca2+ homeostasis is an important early event in the pathogenesis of this disorder and suggest that the use of Ca2+ channel blockers in advance of established clinical disease could prevent hypertrophic cardiomyopathy caused by sarcomere protein gene mutations.
AB - Dominant mutations in sarcomere protein genes cause hypertrophic cardiomyopathy, an inherited human disorder with increased ventricular wall thickness, myocyte hypertrophy, and disarray. To understand the early consequences of mutant sarcomere proteins, we have studied mice (designated αMHC403/+) bearing an Arg403Gln missense mutation in the α cardiac myosin heavy chain. We demonstrate that Ca2+ is reduced in the sarcoplasmic reticulum of αMHC403/+ mice, and levels of the sarcoplasmic reticulum Ca2+-binding protein calsequestrin are diminished in advance of changes in cardiac histology or morphology. Further evidence for dysregulation of sarcoplasmic reticulum Ca2+ in these animals is seen in their decreased expression of the ryanodine receptor Ca2+-release channel and its associated membrane proteins and in an increase in ryanodine receptor phosphorylation. Early administration of the L-type Ca2+ channel inhibitor diltiazem restores normal levels of these sarcoplasmic reticular proteins and prevents the development of pathology in αMHC403/+ mice. We conclude that disruption of sarcoplasmic reticulum Ca2+ homeostasis is an important early event in the pathogenesis of this disorder and suggest that the use of Ca2+ channel blockers in advance of established clinical disease could prevent hypertrophic cardiomyopathy caused by sarcomere protein gene mutations.
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U2 - 10.1172/JCI200214677
DO - 10.1172/JCI200214677
M3 - Article
C2 - 11956238
AN - SCOPUS:0036117921
SN - 0021-9738
VL - 109
SP - 1013
EP - 1020
JO - Journal of Clinical Investigation
JF - Journal of Clinical Investigation
IS - 8
ER -