Department of Urology, The First Affiliated Hospital of Harbin Medical University, No.23 You Zheng Street, Harbin 150001, Heilongjiang, China.
Department of Urology, The First Affiliated Hospital of Harbin Medical University, No.23 You Zheng Street, Harbin 150001, Heilongjiang, China.
Life Sci. 2020 Jan 15;241:117108. doi: 10.1016/j.lfs.2019.117108. Epub 2019 Nov 28.
Telmisartan (TLM), a highly selective angiotensin II type 1 receptor blocker (ARB) and partial PPAR-γ agonist, has versatile beneficial effects against oxidative stress, apoptosis, inflammatory responses and epithelial-mesenchymal transition (EMT). However, its underlying mechanism of inhibiting oxalate and calcium oxalate (CaOx) crystal-induced EMT by activating the PPAR-γ pathway remains unclear.
CCK-8 assays were used to evaluate the effects of TLM on cell viability. In addition, intracellular reactive oxygen species (ROS) levels were measured by the cell-permeable fluorogenic probe 2,7-dichlorofluorescein diacetate (DCFH-DA). Wound-healing and Transwell assays were used to evaluate the migration ability of HK2 cells exposed to oxalate. Moreover, immunofluorescence, immunohistochemistry and western blotting were used to examine the expression of E-cadherin, N-cadherin, vimentin and α-SMA and explore the underlying molecular mechanisms in HK2 cells and a stone-forming rat model.
Our results showed that TLM treatment could protect HK2 cells from oxalate-induced cytotoxicity and oxidative stress injury. Additionally, TLM prevented EMT induction by oxalate and CaOx crystals via the PPAR-γ-AKT/STAT3/p38 MAPK-Snail pathway in vitro and in vivo. However, knockdown of PPAR-γ with small interfering RNA or the PPAR-γ-specific antagonist GW9662 abrogated these protective effects of TLM.
As a PPAR-γ agonist, TLM can ameliorate oxalate and CaOx crystal-induced EMT by exerting an antioxidant effect through the PPAR-γ-AKT/STAT3/p38 MAPK-Snail signaling pathway. Therefore, TLM can block EMT progression and could be a potential therapeutic agent for preventing and treating calcium oxalate urolithiasis formation and recurrence.
替米沙坦（TLM）是一种高度选择性的血管紧张素 II 型 1 型受体阻滞剂（ARB）和部分过氧化物酶体增殖物激活受体-γ 激动剂，具有多种有益作用，可对抗氧化应激、细胞凋亡、炎症反应和上皮-间充质转化（EMT）。然而，其通过激活过氧化物酶体增殖物激活受体-γ 通路抑制草酸盐和草酸钙（CaOx）晶体诱导的 EMT 的潜在机制尚不清楚。
使用 CCK-8 测定法评估 TLM 对细胞活力的影响。此外，通过细胞通透性荧光探针 2,7-二氯荧光素二乙酸酯（DCFH-DA）测量细胞内活性氧（ROS）水平。使用划痕愈合和 Transwell 测定法评估暴露于草酸盐的 HK2 细胞的迁移能力。此外，免疫荧光、免疫组织化学和 Western blot 用于检测 HK2 细胞和结石形成大鼠模型中 E-钙粘蛋白、N-钙粘蛋白、波形蛋白和α-SMA 的表达，并探讨潜在的分子机制。
我们的结果表明，TLM 处理可保护 HK2 细胞免受草酸盐诱导的细胞毒性和氧化应激损伤。此外，TLM 通过 PPAR-γ-AKT/STAT3/p38 MAPK-Snail 通路在体外和体内防止草酸盐和 CaOx 晶体诱导的 EMT 诱导。然而，用小干扰 RNA 敲低 PPAR-γ 或使用 PPAR-γ 特异性拮抗剂 GW9662 会破坏 TLM 的这些保护作用。
作为一种过氧化物酶体增殖物激活受体-γ 激动剂，TLM 可以通过 PPAR-γ-AKT/STAT3/p38 MAPK-Snail 信号通路发挥抗氧化作用，改善草酸盐和 CaOx 晶体诱导的 EMT。因此，TLM 可以阻断 EMT 进展，可能是预防和治疗草酸钙尿石形成和复发的潜在治疗剂。
