Preventive Treatment Center, Shenzhen Hospital of Integrated Traditional Chinese and Western Medicine, Shenzhen, Guangdong, China.
Department of Endocrinology, Shenzhen Hospital of Integrated Traditional Chinese and Western Medicine, Shenzhen, Guangdong, China.
Environ Toxicol. 2022 Mar;37(3):637-649. doi: 10.1002/tox.23431. Epub 2021 Dec 11.
Diabetic nephropathy (DN) is a diabetic complication that can cause renal failure. β-amyrin has been identified to possess anti-diabetic property. This study was designed to evaluate the potential role of β-amyrin in DN and its underlying mechanism. Streptozotocin-induced diabetic mice were used as the in vivo model, and high glucose (HG)-stimulated human proximal tubular HK-2 cells were utilized as the in vitro model. Renal histological changes in mice were assessed by hematoxylin-eosin and periodic acid-Schiff staining. HK-2 cell viability and apoptosis were detected by Cell Counting Kit-8 assay and flow cytometry analysis, respectively. β-amyrin was found to ameliorate kidney injury in DN mice and suppressed inflammatory response as well as apoptosis of HG-stimulated HK-2 cells. miR-181-5p expression in murine renal tissues and HK-2 cells was detected by in situ hybridization (ISH) and fluorescence in situ hybridization (FISH). MiR-181b-5p, a previously identified target for diabetic kidney disease, was downregulated in renal tissues and HG stimulated HK-2 cells, and β-amyrin induced the upregulation of miR-181b-5p. Binding relationship between miR-181b-5p and high mobility group box 2 (HMGB2) was confirmed by luciferase reporter assay. MiR-181b-5p bound to 3' untranslated region of HMGB2 to suppress its expression. As shown by immunohistochemical staining and immunofluorescence staining, HMGB2 was upregulated in the in vivo and in vitro models of DN, and β-amyrin induced the downregulation of HMGB2. Moreover, HMGB2 overexpression neutralized the suppressive effects of miR-181b-5p elevation on the inflammatory response and apoptosis of HG-treated HK-2 cells. Overall, β-amyrin ameliorates DN in mice and suppresses inflammatory response and apoptosis of HG-stimulated HK-2 cells via the miR-181b-5p/HMGB2 axis.
糖尿病肾病（DN）是一种糖尿病并发症，可导致肾衰竭。β-香树脂醇已被确定具有抗糖尿病作用。本研究旨在评估β-香树脂醇在 DN 中的潜在作用及其潜在机制。链脲佐菌素诱导的糖尿病小鼠被用作体内模型，高糖（HG）刺激的人近端肾小管 HK-2 细胞被用作体外模型。通过苏木精-伊红和过碘酸-希夫染色评估小鼠肾脏组织学变化。通过细胞计数试剂盒-8 测定和流式细胞术分析分别检测 HK-2 细胞活力和凋亡。发现β-香树脂醇可改善 DN 小鼠的肾脏损伤，并抑制 HG 刺激的 HK-2 细胞的炎症反应和凋亡。原位杂交（ISH）和荧光原位杂交（FISH）检测鼠肾组织和 HK-2 细胞中的 miR-181-5p 表达。miR-181b-5p 是一种先前鉴定的糖尿病肾病靶标，在肾脏组织和 HG 刺激的 HK-2 细胞中下调，β-香树脂醇诱导其上调。荧光素酶报告基因测定证实 miR-181b-5p 与高迁移率族蛋白 B2（HMGB2）之间存在结合关系。miR-181b-5p 结合到 HMGB2 的 3'非翻译区以抑制其表达。免疫组织化学染色和免疫荧光染色显示，DN 的体内和体外模型中 HMGB2 上调，β-香树脂醇诱导 HMGB2 下调。此外，HMGB2 过表达中和了 miR-181b-5p 升高对 HG 处理的 HK-2 细胞炎症反应和凋亡的抑制作用。总之，β-香树脂醇通过 miR-181b-5p/HMGB2 轴改善小鼠的 DN，并抑制 HG 刺激的 HK-2 细胞的炎症反应和凋亡。
