Inhibition of the prostaglandin D2-GPR44/DP2 axis improves human islet survival and function
Inhibition of the prostaglandin D2-GPR44/DP2 axis improves human islet survival and function
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DOI：
10.1007/s00125-020-05138-z
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发表时间：
2020-04-29
期刊：
影响因子：
8.2
通讯作者：
Winzell, Maria Sorhede
中科院分区：
文献类型：
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作者：
Abadpour, Shadab;Tyrberg, Bjorn;Winzell, Maria Sorhede
目的/假设炎症信号和前列腺素合成增加在糖尿病的发展过程中发挥作用。前列腺素D-2（PGD（2））受体GPR 44/DP 2在人胰岛中高度表达，并且该途径的激活导致胰岛素分泌受损。GPR 44激活对慢性高血糖状态下胰岛功能和存活率的作用尚不清楚。在这项研究中，我们研究了GPR 44抑制通过使用选择性GPR 44拮抗剂（AZ 8154）在人胰岛在体外和在体内糖尿病小鼠移植人胰岛。方法体外培养人胰岛细胞，观察GPR 44抑制剂对胰岛细胞存活率的影响。此外，在暴露于高浓度葡萄糖（HG）和IL-1 β的人胰岛中研究了GPR 44抑制的分子机制。对于研究的体内部分，将人胰岛移植到免疫缺陷型糖尿病小鼠的肾包膜下，并从移植日开始用6、60或100 mg/kg/天的GPR 44拮抗剂处理，直至移植后第4天（短期研究）或第17天（长期研究）。在移植后第10天和第15天对小鼠进行IVGTT。研究结束后，在移植的人胰岛中分析代谢变量、循环人促炎细胞因子和肝细胞生长因子（HGF）。结果PGD（2）或促炎细胞因子可诱导人胰岛细胞凋亡，而抑制GPR 44则可逆转这种作用。GPR 44抑制拮抗人胰岛中由HG和IL-1 β诱导的葡萄糖刺激的胰岛素分泌的减少。这伴随着Akt-糖原合成酶激酶3 β信号通路的激活以及叉头盒O-1的磷酸化和失活以及胰腺和十二指肠同源盒-1和HGF的上调。对移植有少量人胰岛的糖尿病小鼠施用GPR 44拮抗剂长达17天导致空腹血糖降低和IVGTT期间葡萄糖波动降低。在第4天和整个给药期间，与溶媒组相比，人C肽水平升高，支持葡萄糖调节改善。GPR 44抑制降低了TNF-α和生长调节癌基因-α/趋化因子（C-X-C基序）配体1的血浆水平，并增加了人类胰岛中HGF的水平。结论/解释抑制人类胰岛中的GPR 44具有改善胰岛功能和在炎症和高血糖应激下的存活率的潜力。这可能对移植后胰岛的更好存活率有影响。
Aims/hypothesis Inflammatory signals and increased prostaglandin synthesis play a role during the development of diabetes. The prostaglandin D-2 (PGD(2)) receptor, GPR44/DP2, is highly expressed in human islets and activation of the pathway results in impaired insulin secretion. The role of GPR44 activation on islet function and survival rate during chronic hyperglycaemic conditions is not known. In this study, we investigate GPR44 inhibition by using a selective GPR44 antagonist (AZ8154) in human islets both in vitro and in vivo in diabetic mice transplanted with human islets. Methods Human islets were exposed to PGD(2) or proinflammatory cytokines in vitro to investigate the effect of GPR44 inhibition on islet survival rate. In addition, the molecular mechanisms of GPR44 inhibition were investigated in human islets exposed to high concentrations of glucose (HG) and to IL-1 beta. For the in vivo part of the study, human islets were transplanted under the kidney capsule of immunodeficient diabetic mice and treated with 6, 60 or 100 mg/kg per day of a GPR44 antagonist starting from the transplantation day until day 4 (short-term study) or day 17 (long-term study) post transplantation. IVGTT was performed on mice at day 10 and day 15 post transplantation. After termination of the study, metabolic variables, circulating human proinflammatory cytokines, and hepatocyte growth factor (HGF) were analysed in the grafted human islets. Results PGD(2) or proinflammatory cytokines induced apoptosis in human islets whereas GPR44 inhibition reversed this effect. GPR44 inhibition antagonised the reduction in glucose-stimulated insulin secretion induced by HG and IL-1 beta in human islets. This was accompanied by activation of the Akt-glycogen synthase kinase 3 beta signalling pathway together with phosphorylation and inactivation of forkhead box O-1and upregulation of pancreatic and duodenal homeobox-1 and HGF. Administration of the GPR44 antagonist for up to 17 days to diabetic mice transplanted with a marginal number of human islets resulted in reduced fasting blood glucose and lower glucose excursions during IVGTT. Improved glucose regulation was supported by increased human C-peptide levels compared with the vehicle group at day 4 and throughout the treatment period. GPR44 inhibition reduced plasma levels of TNF-alpha and growth-regulated oncogene-alpha/chemokine (C-X-C motif) ligand 1 and increased the levels of HGF in human islets. Conclusions/interpretation Inhibition of GPR44 in human islets has the potential to improve islet function and survival rate under inflammatory and hyperglycaemic stress. This may have implications for better survival rate of islets following transplantation.