Gi蛋白介导生长抑素5激活对垂体催乳素腺瘤激素分泌的抑制作用  

Gi protein-mediated inhibition of hormone secretion in pituitary prolactinomas by somatostatin 5 activation

作　　者：邓健 孙炜[2] 李朝曦[2] 徐钰 王俊文[2] 韩林 李然 Deng Jian;Sun Wei;Li Chaoxi;Xu Yu;Wang Junwen;Han Lin;Li Ran(Department of Neurosurgery,Hunan Provincial People’s Hospital,the First Affiliated Hospital of Hunan Normal University,Changsha 410005,China;Department of Neurosurgery,Tongji Hospital,Tongji Medical College,Huazhong University of Science and Technology,Wuhan 430030,China)

机构地区：[1]湖南省人民医院(湖南师范大学第一附属医院)神经外科,长沙410005 [2]华中科技大学同济医学院附属同济医院神经外科,武汉430030

出　　处：《中华实验外科杂志》2024年第5期987-990,共4页Chinese Journal of Experimental Surgery

基　　金：国家自然科学基金(82173136)。

摘　　要：目的:通过体外实验探讨生长抑素5(SSTR5)激活对垂体催乳素腺瘤激素分泌的抑制作用及其机制。方法:使用前期研究中构建好的SSTR5过表达的GH3细胞系作为垂体催乳素腺瘤的体外细胞模型,使用SSTR5激动剂BIM23052联合其他G蛋白下游通路的抑制剂进行细胞刺激,荧光素酶报告基因检测Prl-luc启动子活性,酶联免疫吸附实验(ELISA)试剂盒检测细胞上清催乳素(PRL)的浓度。Student’s t检验和单向方差分析进行组间统计分析。结果:预处理Gi蛋白抑制剂百日咳毒素后GH3 SSTR5细胞中Prl启动子活性从对照组[Ctrl(Control)组(100.00±6.82)%比BIM组(BIM23052)组(69.08±7.09)%,t=5.43,P<0.01]到干预组[Ctrl组(107.86±12.40)%比BIM组(115.51±11.76)%,t=0.76,P>0.05],预处理百日咳毒素后细胞上清PRL的浓度变化从对照组[Ctrl组(100.00±12.38)%比BIM组(70.60±9.12)%,t=3.31,P<0.05]到干预组[Ctrl组(91.31±9.81)%比BIM组(89.91±9.48)%,t=0.18,P>0.05],百日咳毒素可消除BIM23052对Prl启动子活性的影响;beta-ARK过表达激活G beta-gamma亚单位,Prl启动子活性从空白转染组[Ctrl组(100.00±3.27)%比BIM组(64.70±2.26)%,t=15.38,P<0.01]到betaARK过表达组[Ctrl组(96.91±5.36)%比BIM组(70.12±6.82)%,t=5.35,P<0.05],beta-ARK过表达并不影响BIM23052对Prl启动子活性的抑制作用。使用cGMP类似物Rp8-pCPT-cGMPS、PKG抑制剂KT5823和PKG inhibitor、PKC广谱抑制剂Staurosporin和G?6983预处理GH3 SSTR5细胞,均不影响BIM23052对Prl启动子活性的抑制作用,其中cGMP类似物Rp8-pCPT-cGMPS为,Prl启动子活性从对照组[Ctrl组(100.00±3.97)%比BIM组(52.98±5.16)%,t=12.5,P<0.01]到干预组[Ctrl组(95.99±5.38)%比BIM组(60.23±2.63)%,t=10.35,P<0.01];PKG抑制剂KT5823为,Prl启动子活性分别从对照组[Ctrl组(100.00±2.50)%比BIM组(72.64±0.45)%,t=18.66,P<0.01]到干预组[Ctrl组(93.13±9.31)%比BIM组(53.54±11.50)%,t=4.30,P<0.05];PKG inhibitor为,对照组[Ctrl组(100.00±7.55)%比BIM组(64.07±3.49)%,t=7.48,P<0.01]到干�Objective To explore the potential mechanism of somatostatin receptor 5(SSTR5)activation in inhibiting hormone secretion in pituitary prolactinoma through in vitro experiments.Methods We utilized our developed SSTR5 overexpressing GH3 cell line as an in vitro cell model for pituitary prolactinoma.Cells were stimulated with the SSTR5 agonist BIM23052 in combination with inhibitors of downstream G protein pathways.The activity of the Prl-luc promoter was assessed using a luciferase reporter gene assay,while the concentration of prolactin(PRL)in the cell supernatant was measured using an enzyme linked immunosorbent assay(ELISA)kit.Statistical analysis between groups was performed using Student’s t-test and one-way ANOVA.Results The activity of Prl promoter in GH3SSTR5 cells after pretreatment with the Gi protein inhibitor pertussis toxin,altered from the control group[Ctrl(Control)group(100.00±6.82)%vs.BIM(BIM23052)group(69.08±7.09)%,t=5.43,P<0.01]to the intervention group[Ctrl group(107.86±12.40)%vs.BIM group(115.51±11.76)%,t=0.76,P>0.05];the concentration change of PRL in cell supernatant shifted from[Ctrl group(100.00±12.38)%vs.BIM group(70.60±9.12)%,t=3.31,P<0.05]to[Ctrl group(91.31±9.81)%vs.BIM group(89.91±9.48)%,t=0.18,P>0.05]after pertussis toxin pretreatment.These results indicated that pertussis toxin can eliminate the effect of BIM23052 on Prl promoter activity.Overexpression of beta-ARK activated G beta-gamma subunit,and Prl promoter activity changed from blank transfection group[Ctrl group(100.00±3.27)%vs.BIM group(64.70±2.26)%,t=15.38,P<0.01]to beta-ARK overexpression group[Ctrl group(96.91±5.36)%vs.BIM group(70.12±6.82)%,t=5.35,P<0.05],and beta-ARK overexpression did not affect the inhibitory effect of BIM23052 on Prl promoter activity.Pretreatment of GH3SSTR5 cells with the cGMP analogue Rp8-pCPT-cGMPS,the PKG inhibitor KT5823 and PKG inhibitor,the PKC broad-spectrum inhibitor Staurosporin,and Gö6983 did not affect the inhibitory effect of BIM23052 on Prl promoter activity,in which the

关 键 词：催乳素瘤 生长抑素受体5 Gi蛋白 

分 类 号：R736.4[医药卫生—肿瘤]