INS-1细胞中生长激素及催乳素受体和IGFBP-3的表达调控

Expression and regulation of GH and PRL receptors in rat insulin producing cell line INS-1

目的 :研究生长激素 (GH)和催乳素 (PRL)受体在鼠胰腺肿瘤 β细胞中的表达和调控及GH调节IGFBP 3的表达调控 .方法 :Northern ,检测PRL ,GH和IGFBP 3的mR NA表达 .细胞培养 ,受体蛋白竞争结合实验 ,检测细胞膜受体特异结合 .Western共价杂交 ,检测INS I细胞中IGFBP 3蛋白表达 .结果 :在INS 1中 ,每个细胞有 6 6 0 0个人生长激素 (hGH)受体蛋白结合点 .GH受体的mRNA分子为 1 .6kb,PRL受体mRNA为 0 . 5kb.bGH和rPRL抑制GH受体mRNA的表达 ,而bGH和rPRL上调促进PRL受体mRNA的表达 .在INS 1中GH ,PRL和IGF I对IGFBP 3的mRNA和蛋白表达均有促进作用 .结论 :GH和PRL控制鼠胰腺β细胞的GH和PRL受体表达 ,GH对IGFBP 3表达作用不是通过IGF

AIM: To study the effects of GH and PRL in rat insulin producing cell line INS I and the effects of GH on IGFBP 3 expression. METHODS: Northern blot was used to determine the expression of PRL, GH and IGFBP 3 mRNA. Cell culture and binding assay were conducted for the analysis of PRL and GH receptors binding sites. RESULTS: Like normal insulin producing β cells, INS 1 expressed both GH and PRL receptors and the majority of human GH (hGH) binding sites on this cell line were of lactogenic specificity. In this cell line are present about 6600 hGH binding sites per cell. Northern blot analysis showed two rnRNA species of 4 and 1.6 kb for the GH receptor and one major species of 10.5 kb for the PRL receptor. The PRL receptor mRNA was up regulated by bovine GH (bGH), rat PRL (rPRL), while bGH and PRL down regulated the expression of GH receptor gene. CONCLUSION: INS I cell line, PRL and GH receptors gene are controlled by PRL and GH. The regulation of GH on IGFBP 3 expression is not through IGF I.