Department of Urology, Hunan Provincial People's Hospital, The First Affiliated Hospital of Hunan Normal University, Changsha, Hunan Province, P.R. China.
Hunan Provincial Institute of Geriatrics, Research Center for Lower Urinary Tract and Pelvic Floor Functional Diseases, Changsha, Hunan Province, P.R. China.
Ren Fail. 2024 Dec;46(2):2387432. doi: 10.1080/0886022X.2024.2387432. Epub 2024 Aug 23.
Ureteral stricture (US) is a pathological stenosis in the urinary tract characterized by increased collagen synthesis and inflammation. Autophagy activation has been shown to ameliorate tissue fibrosis and protect against fibrotic diseases. Verapamil has beneficial therapeutic benefits on fibrotic disorders. The pharmacological effects of verapamil on fibroblast autophagy in US and the underlying mechanism need to be investigated further.
US patients were recruited to isolate scar tissues, hematoxylin-eosin (HE) and Masson trichrome staining were performed to analyze histopathological changes. The US animal model was established and administered with verapamil (0.05 mg/kg) in the drinking water. Transforming growth factor (TGF)-β1 was adopted to facilitate collagen synthesis in fibroblasts. The mRNA and protein expressions were examined by qRT-PCR, western blot, immunofluorescence and immunohistochemistry. ELISA was adopted to measure interleukin (IL)-1β and IL-6 levels. Molecular interaction experiments like dual luciferase reporter and chromatin immunoprecipitation (ChIP) assays were performed to analyze the interaction between signal transducers and activators of transcription 3 (STAT3) and RNA polymerase II associated factor 1 (PAF1).
Herein, our results revealed that verapamil activated TGF-β1-treated fibroblast autophagy and inhibited inflammation and fibrosis by repressing Ca⁄calmodulin-dependent protein kinase II (CaMK II) δ-mediated STAT3 activation. Our following tests revealed that STAT3 activated PAF1 transcription. PAF1 upregulation abrogated the regulatory effect of verapamil on fibroblast autophagy and fibrosis during US progression. Finally, verapamil mitigated US by activating fibroblast autophagy.
Taken together, verapamil activated TGF-β1-treated fibroblast autophagy and inhibited fibrosis by repressing the CaMK IIδ/STAT3/PAF1 axis.
输尿管狭窄（US）是一种以胶原合成增加和炎症为特征的尿路病理性狭窄。自噬激活已被证明能改善组织纤维化并预防纤维化疾病。维拉帕米对纤维性疾病具有有益的治疗作用。维拉帕米对 US 中成纤维细胞自噬的药理作用及其潜在机制尚需进一步研究。
招募 US 患者分离瘢痕组织，行苏木精-伊红（HE）和 Masson 三色染色分析组织病理学变化。建立 US 动物模型，在饮用水中给予维拉帕米（0.05mg/kg）。采用转化生长因子（TGF）-β1促进成纤维细胞胶原合成。采用 qRT-PCR、western blot、免疫荧光和免疫组化检测 mRNA 和蛋白表达。采用 ELISA 法检测白细胞介素（IL）-1β和 IL-6 水平。采用双荧光素酶报告和染色质免疫沉淀（ChIP）等分子相互作用实验分析信号转导和转录激活因子 3（STAT3）与 RNA 聚合酶 II 相关因子 1（PAF1）之间的相互作用。
本研究结果表明，维拉帕米通过抑制 Ca2+/钙调蛋白依赖性蛋白激酶 II（CaMK II）δ 介导的 STAT3 激活，激活 TGF-β1 处理的成纤维细胞自噬，并抑制炎症和纤维化。进一步的实验表明，STAT3 激活 PAF1 转录。PAF1 的上调消除了维拉帕米在 US 进展过程中对成纤维细胞自噬和纤维化的调节作用。最后，维拉帕米通过激活成纤维细胞自噬减轻 US。
综上所述，维拉帕米通过抑制 CaMK IIδ/STAT3/PAF1 轴激活 TGF-β1 处理的成纤维细胞自噬，抑制纤维化。
