微囊胰岛移植通过抑制 Notch-1 信号通路减轻糖尿病肾病足细胞损伤。

Microencapsulated islet transplantation alleviates podocyte injury in diabetic nephropathy via inhibiting Notch-1 signaling.

机构信息

The First Affiliated Hospital, Wenzhou Medical University, Shangcai Cun, Ouhai Qu, Wenzhou, 325000, Zhejiang Province, China.

出版信息

Transpl Immunol. 2022 Jun;72:101579. doi: 10.1016/j.trim.2022.101579. Epub 2022 Mar 9.

DOI:10.1016/j.trim.2022.101579

PMID:35278650

Abstract

OBJECTIVE

Podocyte injury has a critical role in the pathogenesis of diabetic nephropathy (DN). Microencapsulated islet transplantation (MIT) is identified as an effective method for improving the clinical condition of DN. This study aimed to explore the role and mechanism of MIT in alleviating podocyte injury in DN.

METHODS

A mouse model of DN was constructed using streptozotocin (STZ). Mice were divided into 3 groups: the untreated diabetic nephropathy group (DN group), the microencapsulated islet transplantation-treated group (MIT group) and the control group. The mice were raised for 6 weeks posterior to islet transplantation to identify the role of MIT. Renal function and structure of glomerular filtration barrier were assessed by urine analysis, histopathological examination, and transmission electron microscopy. The expression levels of several proteins including Caspase-3, Bcl2/Bax, β-galactosidase, Ki-67, synaptopodin, WT-1, Jagged-1, Notch-1, and Hes-1 in renal tissues were identified via immunohistochemistry (IHC), immunofluorescence (IF), and western blotting techniques.

RESULTS

Compared with the DN group, the MIT group presented decreased levels of blood glucose, urinary albumin/creatinine, urea nitrogen, and serum creatinine while their body weight gradually increased. Glomerular injury in the MIT group was significantly better than that in the DN group. The MIT group indicated significantly decreased expression of Caspase-3, β-galactosidase, Bax/Bcl-2, and Ki-67 when compared with DN group, while the proportion of synaptopodin- and WT-1-positive cells was significantly increased (P < 0.05). The protein expression of Jagged-1, Notch-1, and Hes-1 in the glomerulus of the MIT group was significantly lower than that in the DN group (P < 0.05).

CONCLUSION

MIT alleviates podocyte injury induced by DN by inhibiting Notch-1 signaling. The identification of signaling pathways influencing podocyte restoration can help evaluate personalized medicine efficacy for patients treated with islet transplantation.

摘要

目的

足细胞损伤在糖尿病肾病（DN）发病机制中起着关键作用。微囊胰岛移植（MIT）被确定为改善 DN 临床状况的有效方法。本研究旨在探讨 MIT 在缓解 DN 中足细胞损伤的作用和机制。

方法

使用链脲佐菌素（STZ）构建 DN 小鼠模型。将小鼠分为 3 组：未治疗的糖尿病肾病组（DN 组）、微囊胰岛移植治疗组（MIT 组）和对照组。在胰岛移植后 6 周对小鼠进行培养，以确定 MIT 的作用。通过尿分析、组织病理学检查和透射电子显微镜评估肾功能和肾小球滤过屏障的结构。通过免疫组织化学（IHC）、免疫荧光（IF）和 Western blot 技术鉴定肾组织中 Caspase-3、Bcl2/Bax、β-半乳糖苷酶、Ki-67、突触蛋白、WT-1、Jagged-1、Notch-1 和 Hes-1 等几种蛋白质的表达水平。

结果

与 DN 组相比，MIT 组的血糖、尿白蛋白/肌酐、尿素氮和血清肌酐水平降低，而体重逐渐增加。MIT 组的肾小球损伤明显好于 DN 组。与 DN 组相比，MIT 组 Caspase-3、β-半乳糖苷酶、Bax/Bcl-2 和 Ki-67 的表达明显降低，而突触蛋白和 WT-1 阳性细胞的比例明显增加（P<0.05）。MIT 组肾小球中 Jagged-1、Notch-1 和 Hes-1 的蛋白表达明显低于 DN 组（P<0.05）。