Anhui Provincial Key Laboratory for Local Livestock and Poultry Genetic Resource Conservation and Bio-Breeding, 130 Changjiang West Road, Hefei, 230036, Anhui, China.
Department of Animal Veterinary Science, College of Animal Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei, 230036, Anhui, China.
Reprod Biol Endocrinol. 2022 Jul 12;20(1):100. doi: 10.1186/s12958-022-00966-7.
Insulin-like growth factor-binding protein-5 (IGFBP-5) has recently been shown to alter the reproductive capacity by regulating insulin-like growth factor (IGF) bioavailability or IGF-independent effects. The present study aimed to investigate the effect and mechanism of IGFBP-5 on the onset of puberty in female rats. Immunofluorescence and real-time quantitative PCR were used to determine the expression and location of IGFBP-5 mRNA and protein distribution in the infant's hypothalamus-pituitary-ovary (HPO) axis prepuberty, peripuberty, puberty and adult female rats. Prepubertal rats with IGFBP-5 intracerebroventricular (ICV) were injected to determine the puberty-related genes expression and the concentrations of reproductive hormones. Primary hypothalamic cells were treated with IGFBP-5 to determine the expression of puberty-related genes and the Akt and mTOR proteins. Results showed that Igfbp-5 mRNA and protein were present on the HPO axis. The addition of IGFBP-5 to primary hypothalamic cells inhibited the expression of Gnrh and Igf-1 mRNAs (P < 0.05) and increased the expression of AKT and mTOR protein (P < 0.01). IGFBP-5 ICV-injection delayed the onset of puberty, reduced Gnrh, Igf-1, and Fshβ mRNAs, and decreased the concentrations of E2, P4, FSH,serum LH levels and the ovaries weight (P < 0.05). More corpus luteum and fewer primary follicles were found after IGFBP-5 injection (P < 0.05).
胰岛素样生长因子结合蛋白-5 (IGFBP-5) 最近被证明通过调节胰岛素样生长因子 (IGF) 的生物利用度或 IGF 非依赖性作用来改变生殖能力。本研究旨在探讨 IGFBP-5 对雌性大鼠青春期开始的影响及其机制。免疫荧光和实时定量 PCR 用于确定 IGFBP-5 mRNA 的表达和位置以及蛋白质在婴儿下丘脑-垂体-卵巢 (HPO) 轴青春期前、青春期、青春期和成年雌性大鼠中的分布。用 IGFBP-5 对青春期前大鼠进行侧脑室 (ICV) 注射，以确定与青春期相关的基因表达和生殖激素的浓度。用 IGFBP-5 处理原代下丘脑细胞，以确定与青春期相关的基因和 Akt 和 mTOR 蛋白的表达。结果表明，Igfbp-5 mRNA 和蛋白质存在于 HPO 轴上。将 IGFBP-5 添加到原代下丘脑细胞中抑制了 Gnrh 和 Igf-1 mRNAs 的表达（P<0.05），并增加了 AKT 和 mTOR 蛋白的表达（P<0.01）。ICV 注射 IGFBP-5 可延迟青春期的开始，降低 Gnrh、Igf-1 和 Fshβ mRNAs 的浓度，并降低 E2、P4、FSH、血清 LH 水平和卵巢重量（P<0.05）。IGFBP-5 注射后发现更多的黄体和更少的初级卵泡（P<0.05）。
