Tan Jiamei, Wang Zongjie, Yang Mingmao, Zhang Ruihang, Xue Zhongqiang, Zhou Dong, Wang Aihua, Lin Pengfei, Jin Yaping
Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, China.
Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, China.
Animals (Basel). 2025 Jun 23;15(13):1847. doi: 10.3390/ani15131847.
Bovine endometritis is a common endocrine and reproductive disorder in postpartum dairy cows, closely associated with elevated systemic oxidative stress. This disease can lead to delayed uterine involution, repeated breeding failure, and significant economic losses in the dairy industry. Studies suggest that oxidative stress may contribute to the pathological progression of endometritis by regulating ECM remodeling, but the specific molecular mechanisms remain unclear. ECM homeostasis relies on the coordinated action of matrix metalloproteinases (e.g., MMP2, MMP9) and collagen (e.g., type IV collagen, COL-IV), while the TGFβ1/Smad3 signaling pathway is implicated in ECM metabolic regulation. Therefore, elucidating the regulatory mechanisms of oxidative-stress-mediated TGFβ1/Smad3 signaling on ECM remodeling is crucial for understanding the pathogenesis of endometritis. This study investigates postpartum bovine uterine tissues, comparing inflammatory cytokines (IL-1β, IL-6, TNF-α) and oxidative-stress-related factors (GPx, SOD, CAT) between healthy and endometritis groups. Additionally, the differences in ECM-remodeling-associated proteins (MMP2, MMP9, COL-IV) and TGFβ1/Smad3 pathway activity are analyzed. To further validate the mechanisms, an oxidative stress model is established in vitro by treating bovine endometrial epithelial cells (bEECs) with 200 μM HO for 4 h, followed by the valuation of the same indicators. Furthermore, gene silencing to downregulate Smad3 expression or inhibitor-mediated suppression of TGFβ1/Smad3 pathway activity is performed to observe their regulatory effects on MMP2, MMP9, and COL-IV. The results demonstrate that oxidative-stress-mediated endometritis significantly upregulates MMP2, MMP9, and the TGFβ1/Smad3 pathway activity, while suppressing COL-IV expression. Functional genetic experiments further reveal the dual regulatory role of the TGFβ1/Smad3 pathway in ECM remodeling: (1) pathway activation promotes MMP2/MMP9 expression, accelerating COL-IV degradation; (2) Smad3 positively regulates COL-IV synthesis. These findings provide a theoretical basis for targeting the TGFβ1/Smad3 pathway to mitigate the pathological progression of endometritis.
牛子宫内膜炎是产后奶牛常见的内分泌和生殖系统疾病，与全身氧化应激升高密切相关。这种疾病可导致子宫复旧延迟、反复配种失败，并给奶牛业造成重大经济损失。研究表明，氧化应激可能通过调节细胞外基质（ECM）重塑促进子宫内膜炎的病理进展，但其具体分子机制尚不清楚。ECM稳态依赖于基质金属蛋白酶（如MMP2、MMP9）和胶原蛋白（如IV型胶原蛋白，COL-IV）的协同作用，而TGFβ1/Smad3信号通路参与ECM代谢调节。因此，阐明氧化应激介导的TGFβ1/Smad3信号对ECM重塑的调控机制对于理解子宫内膜炎的发病机制至关重要。本研究对产后牛子宫组织进行研究，比较健康组和子宫内膜炎组之间的炎性细胞因子（IL-1β、IL-6、TNF-α）和氧化应激相关因子（GPx、SOD、CAT）。此外，分析ECM重塑相关蛋白（MMP2、MMP9、COL-IV）和TGFβ1/Smad3通路活性的差异。为进一步验证机制，通过用200μM过氧化氢（HO）处理牛子宫内膜上皮细胞（bEECs）4小时在体外建立氧化应激模型，随后评估相同指标。此外，进行基因沉默以下调Smad3表达或抑制剂介导的TGFβ1/Smad3通路活性抑制，以观察它们对MMP2、MMP9和COL-IV的调控作用。结果表明，氧化应激介导的子宫内膜炎显著上调MMP2、MMP9和TGFβ1/Smad3通路活性，同时抑制COL-IV表达。功能基因实验进一步揭示了TGFβ1/Smad3通路在ECM重塑中的双重调控作用：（1）通路激活促进MMP2/MMP9表达，加速COL-IV降解；（2）Smad3正向调节COL-IV合成。这些发现为靶向TGFβ1/Smad3通路减轻子宫内膜炎的病理进展提供了理论依据。
