apelin-13-peptide and Vascular-Calcification

Vascular calcification (VC) is an inducement of many cardiovascular diseases. Clinic evidences have confirmed that diabetes was the independent risk factor for VC, and the mechanism has not been well explored. Apelin as a ligand molecule is widely found in the cardiovascular system and showed potential in inhibiting VC, but the inhibitory effect and mechanism of apelin-13 against high glucose-induced VC have not been investigated yet. Herein, apelin-13 was employed to inhibit high glucose-induced VC in mouse aortic vascular smooth muscle cells (MOVAS), and the underlying mechanism was explored. The results showed that apelin-13 significantly inhibited high glucose-induced cells proliferation, migration and invasion of MOVAS cells. Apelin-13 also effectively attenuated high glucose-induced calcification by inhibiting alkaline phosphatase (ALP) activity and expression. Further investigation revealed that apelin-13 dramatically suppressed high glucose-induced DNA damage through inhibiting reactive oxide species (ROS) generation. Moreover, apelin-13 also effectively improved high glucose-induced dysfunction of MAPKs and PI3K/AKT. Inhibition of ERK by inhibitor (U0126) significantly blocked high glucose-induced calcification, which further confirmed the significance of MAPKs. Taken together, these results suggested that apelin-13 had the potential to attenuate high glucose-induced calcification of MOVAS cells by inhibiting ROS-mediated DNA damage and regulating MAPKs and PI3K/AKT pathways. Our findings validated the strategy of using apelin-13 maybe a novel way in treating high glucose-mediated VC.

Topics: Alkaline Phosphatase; Animals; Aorta; Cell Movement; Cell Proliferation; Cells, Cultured; DNA Damage; Extracellular Signal-Regulated MAP Kinases; Glucose; Intercellular Signaling Peptides and Proteins; Mice; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Oxidative Stress; Phosphatidylinositol 3-Kinase; Proto-Oncogene Proteins c-akt; Reactive Oxygen Species; Signal Transduction; Vascular Calcification

Vascular calcification (VC) is closely related to cardiovascular events in chronic kidney disease (CKD). Apelin has emerged as a potent regulator of cardiovascular function, but its role in VC during CKD remains unknown. We determined whether apelin plays a role in phosphate-induced mineralization of human aortic smooth muscle cells (HASMCs) and in adenine-induced CKD rats with aortic calcification.. In vitro, apelin-13 was found to inhibit calcium deposition in HASMCs (Pi(+) Apelin(+) group vs Pi(+) Apelin(-) group: 50.1 ± 6.21 ug/mg vs 146.67 ± 10.02 ug/mg protein, p = 0.012) and to suppress the induction of the osteoblastic transformation genes BMP-2, osteoprotegerin (OPG) and Cbfa1. This effect was mediated by interference of the sodium-dependent phosphate cotransporter (Pit-1) expression and phosphate uptake. In vivo, decreased plasma apelin levels (adenine(+) apelin(-) vs vehicle: 0.37 ± 0.09 ng/ml vs 0.68 ± 0.16 ng/ml, p = 0.003) and downregulation of APJ in the aorta were found in adenine-induced CKD rats with hyperphosphatemia (adenine(+) apelin(-) vs vehicle: 6.91 ± 0.23 mmoL/L vs 2.3 ± 0.07 mmoL/L, p = 0.001) and aortic calcification. Exogenous supplementation of apelin-13 normalized the level of the apelin/APJ system and significantly ameliorated aortic calcification, as well as the suppression of Runx2, OPG and Pit-1 expression.. Apelin ameliorates VC by suppressing osteoblastic differentiation of VSMCs through downregulation of Pit-1. These results suggest apelin may have potential therapeutic value for treatment of VC in CKD.

Topics: Animals; Aorta, Thoracic; Blotting, Western; Cells, Cultured; Core Binding Factor Alpha 1 Subunit; Gene Expression Regulation; Immunohistochemistry; Intercellular Signaling Peptides and Proteins; Ligands; Male; Muscle, Smooth, Vascular; Osteoprotegerin; Rats; Rats, Sprague-Dawley; Real-Time Polymerase Chain Reaction; Renal Insufficiency, Chronic; RNA; Sodium-Phosphate Cotransporter Proteins, Type III; Vascular Calcification