TY - JOUR
T1 - Sarco(endo)plasmic reticulum Ca2+ ATPase (SERCA) gene silencing and remodeling of the Ca2+ signaling mechanism in cardiac myocytes
AU - Seth, M.
AU - Sumbilla, C.
AU - Mullen, S. P.
AU - Lewis, D.
AU - Klein, M. G.
AU - Hussain, A.
AU - Soboloff, J.
AU - Gill, D. L.
AU - Inesi, G.
PY - 2004/11/23
Y1 - 2004/11/23
N2 - Transient elevations of cytosolic Ca2+ are a common mechanism of cellular signaling. In striated muscle, the sarco(endo)plasmic reticulum Ca2+ ATPase (SERCA) plays an important role in terminating Ca 2+ transients by returning cytosolic Ca2+ to intracellular stores. Stored Ca2+can then be released again for subsequent signaling. We down-regulated SERCA2 gene expression in cultured cardiac myocytes by means of endogenous transcription of small interfering RNA encoded by an exogenous cDNA template. The cDNA template was delivered by adenovirus vector. Reduction of SERCA expression in all myocytes in culture was documented by immunochemistry, real-time RT-PCR, and determination of ATP-dependent Ca 2+ transport. The reduction of SERCA2 expression was associated with the up-regulation of transient receptor potential (TRP) channel proteins (TRPC4 and TRPC5) and Na+/Ca2+ exchanger, indicating that intracellular store deficiency was compensated for by Ca2+ fluxes through the plasma membrane. In fact, SERCA silencing was followed by increased transcription of Na+/ Ca2+ exchanger, TRPC4, TRPC5, and related transcriptional factors, such as stimulating protein 1, myocyte enhancer factor 2, and nuclear factor of activated cells 4, through activation of calcineurin. This finding demonstrates that the observed compensation occurs through transcriptional crosstalk and the remodeling of Ca2+ signaling pathways. The wide significance of this regulatory mechanism is related to its general involvement in Ca2+ signaling dynamics and in cardiac development and hypertrophy.
AB - Transient elevations of cytosolic Ca2+ are a common mechanism of cellular signaling. In striated muscle, the sarco(endo)plasmic reticulum Ca2+ ATPase (SERCA) plays an important role in terminating Ca 2+ transients by returning cytosolic Ca2+ to intracellular stores. Stored Ca2+can then be released again for subsequent signaling. We down-regulated SERCA2 gene expression in cultured cardiac myocytes by means of endogenous transcription of small interfering RNA encoded by an exogenous cDNA template. The cDNA template was delivered by adenovirus vector. Reduction of SERCA expression in all myocytes in culture was documented by immunochemistry, real-time RT-PCR, and determination of ATP-dependent Ca 2+ transport. The reduction of SERCA2 expression was associated with the up-regulation of transient receptor potential (TRP) channel proteins (TRPC4 and TRPC5) and Na+/Ca2+ exchanger, indicating that intracellular store deficiency was compensated for by Ca2+ fluxes through the plasma membrane. In fact, SERCA silencing was followed by increased transcription of Na+/ Ca2+ exchanger, TRPC4, TRPC5, and related transcriptional factors, such as stimulating protein 1, myocyte enhancer factor 2, and nuclear factor of activated cells 4, through activation of calcineurin. This finding demonstrates that the observed compensation occurs through transcriptional crosstalk and the remodeling of Ca2+ signaling pathways. The wide significance of this regulatory mechanism is related to its general involvement in Ca2+ signaling dynamics and in cardiac development and hypertrophy.
KW - Calcineurin
KW - Na/Ca exchanger
KW - Small interfering RNA
KW - Transient receptor potential channel
UR - http://www.scopus.com/inward/record.url?scp=9344229235&partnerID=8YFLogxK
U2 - 10.1073/pnas.0407537101
DO - 10.1073/pnas.0407537101
M3 - Article
SN - 0027-8424
VL - 101
SP - 16683
EP - 16688
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 47
ER -