TRPV₁ channels in cardiovascular system: A double edged sword?

Apart from modulating nociception, there is vital role of TRPV₁ channels in modulating atherosclerosis, congestive heart failure, systemic hypertension, pulmonary hypertension, hemorrhagic shock and vascular remodeling. TRPV₁ channel activation has shielding effect against the development of atherosclerosis and systemic hypertension. TRPV₁ channel activation alleviates the formation of atherosclerotic lesions via increasing the expression of cholesterol efflux regulatory protein, UCP 2 and enhancing autophagy. Furthermore, activation of these channels enhances Na⁺ excretion and NO release to reduce the blood pressure. TRPV₁ channel activation in the cardiac sensory neurons and subsequent CGRP release reduces ischemia-reperfusion injury. Activation of these channels during conditioning enhances CGRP and SP release from the sensory nerve fibers innervating the heart to induce cardioprotection. However, activation of these channels may elicit detrimental effects in pulmonary hypertension, hemorrhage and vascular remodeling. Activation of TRPV₁ channels enhances smooth muscle cell proliferation to promote pulmonary hypertension. Moreover, TRPV₁ channel inhibition reduces massive catecholamine release, improves survival during hemorrhage. Activation of these channels enhances vascular remodeling via enhancing NO release. Furthermore, dual role of TRPV₁ channels has been reported in the perpetuation of congestive heart failure. On one hand, TRPV₁ channel activation increases the expression of UCP2, PPAR- δ and mitochondrial sirtuin 3 to decrease oxidative stress and reduce heart injury. On the other hand, activation of these channels may enhance the expression of hypertrophic fibrotic proteins viz. GATA4, MMP to promote cardiac fibrosis. The present review discusses the dual role of activation of TRPV₁ channels in diseases associated with cardiovascular system.