Department of Urology, Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu, China.
Institute of Translational Medicine, Jiangsu University, Zhenjiang, Jiangsu, China.
PLoS One. 2024 Mar 13;19(3):e0295104. doi: 10.1371/journal.pone.0295104. eCollection 2024.
Melatonin (MEL) is an indole amine molecule primarily produced in the pineal gland. Melatonin has been shown in numerous studies to have antifibrotic effects on the kidney, liver, and other organs. However, it is still unclear how melatonin works in bladder fibrosis. We explored how melatonin affects animals with bladder fibrosis and the underlying mechanisms.
MEL was used to treat human bladder smooth muscle cells (HBdSMCs) after they were stimulated with transforming growth factor-β1 (TGF-β1) in vitro. Proteomic analysis and bioinformatic analysis of the altered expression of these proteins were subsequently performed on HBdSMCs from the different processing methods. To construct an in vivo bladder fibrosis model, we injected protamine sulfate (PS) and lipopolysaccharide (LPS) twice a week into the rat bladder for six weeks. After two weeks of PS/LPS treatment, the mice in the treatment group were treated with MEL (20 mg/kg/d) for 4 weeks. Finally, we detected the expression of fibrosis markers from different perspectives. The TGF-β1/Smad pathway and epithelial-mesenchymal transition (EMT) in cell and bladder tissues were also identified. Further proteomic analysis was also performed.
In vitro, we found that TGF-β1 treatment enhanced the expression of the fibrosis markers collagen III and α-SMA in HBdSMCs. E-cadherin expression decreased while the TGF-β1/Smad pathway was activated. Vimentin and N-cadherin expression was also elevated at the same time. Similar findings were observed in the LPS group. After MEL treatment, the expression of collagen III and α-SMA decreased, the expression of E-cadherin increased, and the expression of vimentin and N-cadherin also decreased. According to our quantitative proteomics analysis, CCN1 and SQLE may be important proteins involved in the development of bladder fibrosis. MEL decreased the expression of these genes, leading to the relief of bladder fibrosis. Bioinformatics analysis revealed that the extracellular space structure related to metabolic pathways, actin filament binding, and stress fibers can serve as a pivotal focus in the management of fibrosis.
Melatonin attenuates bladder fibrosis by blocking the TGF-β1/Smad pathway and EMT. CCN1 appears to be a possible therapeutic target for bladder fibrosis.
褪黑素（MEL）是一种主要在松果体中产生的吲哚胺分子。大量研究表明，褪黑素对肾脏、肝脏和其他器官具有抗纤维化作用。然而，褪黑素在膀胱纤维化中的作用机制尚不清楚。我们探讨了褪黑素如何影响膀胱纤维化动物模型，并研究了其潜在的作用机制。
在体外，用转化生长因子-β1（TGF-β1）刺激人膀胱平滑肌细胞（HBdSMCs）后，用 MEL 进行处理。随后，对不同处理方法的 HBdSMCs 进行蛋白质组学分析和生物信息学分析，以研究这些蛋白表达变化的潜在机制。为了构建体内膀胱纤维化模型，我们每周两次向大鼠膀胱内注射鱼精蛋白硫酸盐（PS）和脂多糖（LPS），共 6 周。PS/LPS 处理 2 周后，治疗组小鼠用 MEL（20 mg/kg/d）治疗 4 周。最后，我们从不同角度检测纤维化标志物的表达情况。还鉴定了细胞和膀胱组织中的 TGF-β1/Smad 通路和上皮-间充质转化（EMT）。进一步进行了蛋白质组学分析。
在体外，我们发现 TGF-β1 处理增强了 HBdSMCs 中纤维化标志物胶原 III 和 α-SMA 的表达。E-钙黏蛋白表达降低，同时 TGF-β1/Smad 通路被激活。波形蛋白和 N-钙黏蛋白的表达同时升高。在 LPS 组也观察到类似的发现。用 MEL 处理后，胶原 III 和 α-SMA 的表达减少，E-钙黏蛋白的表达增加，波形蛋白和 N-钙黏蛋白的表达也减少。根据我们的定量蛋白质组学分析，CCN1 和 SQLE 可能是参与膀胱纤维化发展的重要蛋白。MEL 降低了这些基因的表达，从而缓解了膀胱纤维化。生物信息学分析表明，细胞外空间结构与代谢途径、肌动蛋白丝结合和应激纤维有关，可能成为纤维化管理的关键焦点。
褪黑素通过阻断 TGF-β1/Smad 通路和 EMT 来减轻膀胱纤维化。CCN1 似乎是膀胱纤维化的一个潜在治疗靶点。
