Apelin-13

Apelin-13 is a peptide known as the ligand of the G-protein-coupled receptor APJ. ^[1]. Apelin-13 activated this G protein-coupled receptor with an EC50 value of 0.37 nM ^[2]. Apelin has been shown to be involved in the regulation of cardiovascular and fluid homeostasis, food intake, cell proliferation, and angiogenesis ^[1].

Apelin-13 was shown to inhibit insulin secretion stimulated by high glucose concentrations (10 mM) or potentiated by GLP-1 in INS-1 cells ^[3]. Apelin-13 at 200 nM can enhance H9c2 cell proliferation, which is mediated by the ERK1/2 and Akt signaling pathway ^[4].

Apelin-13 treatment significantly lowers blood glucose and protects HFD mice from hyperinsulinemia ^[5]. There are some contradictory reports about the effects of apelin-13/APJ on hypertension. Intraperitoneally administered Apelin-13 reduces blood pressure in hypertensive rats by inhibiting renin-angiotensin system ^[6]. Chronic infusion of apelin-13 into the paraventricular nucleus induces hypertension through increasing the levels of plasma norepinephrine and arginine vasopressin in normotensive rats ^[7].

References:
[1]. Castan-Laurell I, Dray C, AttanÉ C, et al. Apelin, diabetes, and obesity[J]. Endocrine, 2011, 40(1): 1-9.
[2]. Tatemoto K, Hosoya M, Habata Y, et al. Isolation and characterization of a novel endogenous peptide ligand for the human APJ receptor[J]. Biochemical and biophysical research communications, 1998, 251(2): 471-476.
[3]. Guo L, Li Q, Wang W, et al. Apelin inhibits insulin secretion in pancreatic β-cells by activation of PI3-kinase-phosphodiesterase 3B[J]. Endocrine research, 2009, 34(4): 142-154.
[4]. Yin L, Zhang P, Li C, et al. Apelin?13 promotes cell proliferation in the H9c2 cardiomyoblast cell line by triggering extracellular signal?regulated kinase 1/2 and protein kinase B phosphorylation[J]. Molecular Medicine Reports, 2018, 17(1): 447-451.
[5]. AttanÉ C, Foussal C, Le Gonidec S, et al. Apelin treatment increases complete Fatty Acid oxidation, mitochondrial oxidative capacity, and biogenesis in muscle of insulin-resistant mice[J]. Diabetes, 2012, 61(2): 310-320.
[6]. Akc?lar R, Turgut S, Caner V, et al. Apelin effects on blood pressure and RAS in DOCA-salt-induced hypertensive rats[J]. Clinical and Experimental Hypertension, 2013, 35(7): 550-557.
[7]. Zhang F, Sun H J, Xiong X Q, et al. Apelin?\13 and APJ in paraventricular nucleus contribute to hypertension via sympathetic activation and vasopressin release in spontaneously hypertensive rats[J]. Acta physiologica, 2014, 212(1): 17-27.

Apelin-13 是一种肽，被称为 G 蛋白偶联受体 APJ 的配体。 ^[1]。 Apelin-13 激活该 G 蛋白偶联受体，EC50 值为 0.37 nM ^[2]。 Apelin 已被证明参与调节心血管和体液稳态、食物摄入、细胞增殖和血管生成^[1]。

Apelin-13 被证明可抑制胰岛素在 INS-1 细胞中由高浓度葡萄糖 (10 mM) 刺激分泌或由 GLP-1 增强分泌 ^[3]。 200 nM Apelin-13 可增强 H9c2 细胞增殖，这是由 ERK1/2 和 Akt 信号通路介导的^[4]。

Apelin-13 处理可显着降低血糖并保护 HFD 小鼠免受高胰岛素血症^[5]。关于apelin-13/APJ对高血压的影响存在一些相互矛盾的报道。腹腔注射 Apelin-13 通过抑制肾素-血管紧张素系统降低高血压大鼠的血压^[6]。 Apelin-13 长期注入室旁核可通过升高血压正常大鼠的血浆去甲肾上腺素和精氨酸加压素水平诱导高血压^[7]。