Phoenixin (PNX) is a newly discovered peptide produced by proteolytic cleavage of a small integral membrane protein 20 (Smim20), which acts as an important regulator of energy homeostasis and reproduction. Since dysfunction of reproduction is characteristic in polycystic ovarian syndrome (PCOS), the role of PNX in pathogenesis of PCOS needs further investigation. The objective of this study was to determine expression of Smim20, PNX-14 and its receptor GRP173 in the hypothalamus, ovary and periovarian adipose tissue (PAT) of letrozole induced PCOS rats. Phosphorylation of extracellular signal-regulated kinase (ERK1/2), protein kinases A (PKA) and B (Akt) were also estimated. We observed that PCOS rats had high weight gain and a number of ovarian cyst, high levels of testosterone, luteinizing hormone and PNX-14, while low estradiol. Smim20 mRNA expression was higher in the ovary and PAT, while PNX-14 peptide production was higher only in the ovary of PCOS rat. Moreover, in PCOS rats Gpr173 level was lower in PAT but at the protein level increased only in the ovary. Depending on the tissues, kinases phosphorylation were significantly differ in PCOS rats. Our results showed higher levels of PNX-14 in PCOS rats and indicated some novel findings regarding the mechanisms of PCOS pathophysiology.

凤凰蛋白（PNX）是一种新发现的肽，是通过蛋白水解性切割小整体膜蛋白20（Smim20）产生的，该蛋白是能量稳态和繁殖的重要调节剂。由于生殖功能障碍是多囊卵巢综合征（PCOS）的特征，因此PNX在PCOS发病机理中的作用尚需进一步研究。这项研究的目的是确定Smim20的表达来曲唑诱导的PCOS大鼠下丘脑，卵巢和卵巢周围脂肪组织（PAT）中的PNX，PNX-14及其受体GRP173 还估计了细胞外信号调节激酶（ERK1 / 2），蛋白激酶A（PKA）和B（Akt）的磷酸化。我们观察到PCOS大鼠具有高体重增加和许多卵巢囊肿，高水平的睾丸激素，黄体生成素和PNX-14，而雌二醇却低。Smim2 0 mRNA表达在卵巢和PAT中较高，而PNX-14肽的产生仅在PCOS大鼠卵巢中较高。此外，在PCOS大鼠中，Gpr173PAT水平较低，但蛋白质水平仅在卵巢中升高。根据组织的不同，PCOS大鼠中的激酶磷酸化显着不同。我们的研究结果显示PCOS大鼠中PNX-14的水平较高，并表明有关PCOS病理生理机制的一些新发现。