Division of Nephrology, Henan Provincial Hospital of Traditional Chinese Medicine, Henan University of Traditional Chinese Medicine, Zhengzhou, China.
Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, China.
Int Urol Nephrol. 2023 Oct;55(10):2507-2516. doi: 10.1007/s11255-023-03547-8. Epub 2023 Mar 24.
To mechanistically assess the involvement of tenascin-C (TNC) in diabetic nephropathy (DN).
Renal specimens from DN patients were histopathologically examined, and their TNC expression patterns were evaluated via immunohistochemistry. Additionally, the hereditarily diabetic C57BL/KsJ db/db mice were induced to develop DN via adaptive feeding, and then their renal levels of TNC and β-catenin were assessed via western blotting and immunohistochemistry. Furthermore, the TNC and β-catenin levels in primary rat mesangial cells (RMCs) cultured with high glucose levels were assessed via western blotting. In parallel, RMCs cultured with TNC in the presence or absence of the β-catenin blocker ICG-001 were analyzed for their fibronectin and collagen I levels via immunostaining, and for their fibronectin, α-SMA, vimentin, PDGFR-β, PCNA, and β-catenin levels via western blotting.
The TNC levels in the specimens were associated with the pathological classification. In these DN specimens, TNC protein was highly detected in the MCs and slightly in the tubulointerstitium. Renal TNC (P < 0.05) and β-catenin (P < 0.001) were upregulated in db/db vs. db/m mice. High-glucose treatment upregulated TNC (P < 0.01) and β-catenin (P < 0.05) in RMCs. TNC treatment upregulated fibronectin (P < 0.05), α-SMA (P < 0.01), vimentin (P < 0.05), PCNA (P < 0.05), and β-catenin (P < 0.05) in RMCs, as assessed via western blotting. Immunohistochemical analysis confirmed the fibronectin upregulation and showed collagen I upregulation. Western-blot results also showed that levels of fibronectin (P < 0.001), α-SMA (P < 0.01), vimentin (P < 0.001), PCNA (P < 0.05), PDGFR-β (P < 0.05), and β-catenin (P < 0.01) were lower in RMCs co-treated with TNC and ICG-001 than in TNC-treated cells. Immunofluorescence analysis confirmed the decreased fibronectin level and showed that the collagen I level was also decreased by ICG-001.
TNC is upregulated in DN and induces MC proliferation and fibrosis through the β-catenin pathway.
从机制上评估 tenascin-C（TNC）在糖尿病肾病（DN）中的作用。
对 DN 患者的肾组织进行组织病理学检查，并通过免疫组织化学评估其 TNC 表达模式。此外，通过适应性喂养诱导遗传性糖尿病 C57BL/KsJ db/db 小鼠发生 DN，并通过 Western blot 和免疫组织化学评估其肾脏 TNC 和 β-连环蛋白水平。此外，通过 Western blot 评估高糖培养的原代大鼠肾小球系膜细胞（RMC）中 TNC 和 β-连环蛋白的水平。同时，在存在或不存在β-连环蛋白抑制剂 ICG-001 的情况下，分析 TNC 处理的 RMC 中的纤维连接蛋白和 I 型胶原的水平通过免疫染色，以及纤维连接蛋白、α-SMA、波形蛋白、PDGFR-β、PCNA 和 β-连环蛋白水平通过 Western blot。
标本中的 TNC 水平与病理分类相关。在这些 DN 标本中，TNC 蛋白在 MC 中高度检测到，在肾小管间质中略有检测到。与 db/m 小鼠相比，db/db 小鼠的肾 TNC（P<0.05）和β-连环蛋白（P<0.001）上调。高糖处理可上调 RMC 中的 TNC（P<0.01）和β-连环蛋白（P<0.05）。TNC 处理可上调 RMC 中的纤维连接蛋白（P<0.05）、α-SMA（P<0.01）、波形蛋白（P<0.05）、PCNA（P<0.05）和β-连环蛋白（P<0.05），通过 Western blot 进行评估。免疫组织化学分析证实了纤维连接蛋白的上调，并显示胶原 I 的上调。Western blot 结果还显示，TNC 共处理组的纤维连接蛋白（P<0.001）、α-SMA（P<0.01）、波形蛋白（P<0.001）、PCNA（P<0.05）、PDGFR-β（P<0.05）和β-连环蛋白（P<0.01）水平低于 TNC 处理组。免疫荧光分析证实了纤维连接蛋白水平的降低，并表明 ICG-001 还降低了胶原 I 水平。
TNC 在 DN 中上调，并通过 β-连环蛋白途径诱导 MC 增殖和纤维化。
