Oestrogen Inhibits Arterial Calcification by Promoting Autophagy

Abstract

Arterial calcification is a major complication of cardiovascular disease. Oestrogen replacement therapy in postmenopausal women is associated with lower levels of coronary artery calcification, but its mechanism of action remains unclear. Here, we show that oestrogen inhibits the osteoblastic differentiation of vascular smooth muscle cells (VSMCs) in vitro and arterial calcification in vivo by promoting autophagy. Through electron microscopy, GFP–LC3 redistribution, and immunofluorescence analyses as well as measurement of the expression of the autophagosome marker light-chain I/II (LC3I/II) and autophagy protein 5 (Atg5), we show that autophagy is increased in VSMCs by oestrogen in vitro and in vivo. The inhibitory effect of oestrogen on arterial calcification was counteracted by 3-methyladenine (3MA) or knockdown of Atg5 and was increased by rapamycin. Furthermore, the inhibitory effect of oestrogen on arterial calcification and the degree of autophagy induced by oestrogen were blocked by a nonselective oestrogen receptor (ER) antagonist (ICI 182780), a selective oestrogen receptor alpha (ERα) antagonist (MPP), and ERα-specific siRNA. Our data indicate that oestrogen inhibits the osteoblastic differentiation of VSMCs by promoting autophagy through the ERα signalling pathway in vitro and arterial calcification in vivo by increasing autophagy. Our findings provide new insights into the mechanism by which oestrogen contributes to vascular calcification in vitro and in vivo.

Vascular Calcification—New Insights into Its Mechanism

“…Based on previous reports, modulating autophagy was investigated as a preventive strategy against VC. Likewise, representative autophagy inducers, such as rapamycin and valproic acid, have been shown to inhibit VSMC calcification in vitro [120,132]. However, since there is a possibility that pharmaceutical manipulation exhibits a nonspecific, off-target effect, it is necessary to study the therapeutic effect on calcification, as a method to determine autophagy-specific effects.…”

LncRNA‐ES3 inhibition by Bhlhe40 is involved in high glucose–induced calcification/senescence of vascular smooth muscle cells

“…According to the manufacturer's instructions, cell lysates were measured for alkaline phosphatase (ALP) activity using an ALP assay kit (A059-2, Jiancheng, Nanjing) and for osteocalcin secretion using an osteocalcin assay kit (H152, Jiancheng, Nanjing). As previously described, 15 ALP activity and osteocalcin secretion were normalized to the total cellular protein of the cellular layers, as determined by the Bradford protein assay. Results are presented as the fold-change compared with that of the control from three independent experiments.…”

Plasma exosomes derived from patients with end-stage renal disease and renal transplant recipients have different effects on vascular calcification

“…Vascular calci cation is mainly characterized as the medial of aortic calci cation (termed as Mönckeberg's calci cation), and it often happens in patients with chronic kidney disease, especially end stage renal disease (ESRD) [1,2]. Lots of studies have demonstrated that vascular calci cation is not a simple passive process of calcium and phosphorus deposition but an active regulatory process, and the transdifferentiation of vascular smooth muscle cells (VSMCs) into osteoblast-like cells is regarded to be the key pathophysiological factor of vascular calci cation [3][4][5]. However, the speci c mechanism of vascular calci cation in patients with ESRD is still not entirely elucidated.…”