Apelin： a double-edged sword in cardiac hypertrophy

Aim As we all know, apelin acts as the endogenous ligand of APJ, being a member of G protein cou- pled receptors family, apelin/APJ system is involved in plentiful diseases and extremely responsible for the occur- rence and the development of cardiovascular diseases, among many kinds of heart diseases, it is the cardiac hyper- trophy that catches our attention. The myocardial expression of apelin/APJ decreased in rats with left ventrieular hypertrophy suggesting us there is a link between apelin and cardiac hypertrophy. Furthermore, it has been repor- ted that apelin is able to alleviate cardiac hypertrophy induced by Ang II, H202 and exercise. Nevertheless, our la- boratory discovered that apelin is certain to induce cardiac hypertrophy through PI3k-Akt-ERK1/2-p70S6K pathway or via up-regulating the levels of ROS to cause oxidative stress. The above-mentioned contradiction indicates us apelin may have dual effects in cardiac hypertrophy. Moreover, we also illuminate that apelin is involved in some diseases such as obesity, diabetes, hypertension, myoearditis and myocardial infarction, eoineidentally, all these diseases are associated with cardiac hypertrophy. Therefore, this review is aim to unveil the intricate relationship between apelin and cardiac hypertrophy.