Regulatory role of regucalcin in heart calcium signaling: Insight into cardiac failure (Review)

Abstract

Regucalcin was first identified in 1978 as a regulatory protein of Ca2+ signaling in liver cells. Regucalcin was shown to play a multifunctional role in cell regulation, such as maintainance of intracellular Ca2+ homeostasis and suppression of signal transduction, protein synthesis, nuclear function, cell proliferation and apoptosis in various types of cells and tissues. Cardiac excitation-contraction coupling is based on the regulation of intracellular Ca2+ concentration by the Ca2+ pump in the sarcoplasmic reticulum of heart muscle cells. Regucalcin, which is expressed in the heart, was found to increase rat heart sarcoplasmic reticulum Ca2+-ATPase activity and ATP-dependent Ca2+ uptake and mitochondrial Ca2+-ATPase activity. Regucalcin was also shown to suppress Ca2+-dependent protein tyrosine phosphatase, Ca2+/calmodulin-dependent protein phosphatase (calcineurin) and nitric oxide (NO) synthase activity in the heart cytoplasm. Moreover, regucalcin was found to activate superoxide dismutase (SOD), which plays a significant role in the prevention of cell death and apoptosis in the heart. Regucalcin may be a key molecule in heart muscle cell regulation through Ca2+ signaling. Regucalcin may also play a pathophysiological role in heart failure. The aim of this study was to review the recent findings regarding the role of regucalcin in Ca2+ signaling in the heart.

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Recent progress in development of siRNA delivery vehicles for cancer therapy

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