Yan Xuejing, Wu Shen, Liu Qian, Teng Yufei, Wang Ningli, Zhang Jingxue
Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China.
Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, 100069, China.
Heliyon. 2024 Aug 29;10(17):e37137. doi: 10.1016/j.heliyon.2024.e37137. eCollection 2024 Sep 15.
The trabecular meshwork (TM) plays an essential role in the circulation of aqueous humor by sensing mechanical stretch. The balance between the outflow and inflow of aqueous humor is critical in regulating intraocular pressure (IOP). A dysfunctional TM leads to resistance to the outflow of aqueous humor, resulting in an elevated IOP, a major risk factor for glaucoma. It is widely accepted that mutant myocilin (MYOC) can cause damage to the TM. However, few studies have investigated how TM cells carrying mutant MYOC respond to cyclic mechanical stretch (CMS) and whether these cells are more sensitive to CMS under this genetic background. In this study, we applied mechanical stretch to TM cells using the Flexcell system to mimic physiological stress. In addition, we performed genome-wide transcriptome analysis and oxidized lipidomics to systematically compare the gene expression and oxylipin profiles of non-stretched control human primary TM cells, human primary TM cells under CMS (TM-CMS), and human primary TM cells overexpressing MYOC under CMS (S341P-CMS). We found that TM cells that overexpressed MYOC were more sensitive to mechanical stress. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that downregulated genes were most enriched in oxidative phosphorylation, indicating mitochondria dysfunction and the likelihood of oxidative stress. Oxidized lipidomics analysis revealed significant changes in oxylipin profiles between the S341P-CMS and TM-CMS groups. Through further genome-wide transcriptomic analysis, we identified several genes that may be involved in the sensitivity of TM cells that overexpressed MYOC to mechanical stress, including , , , and . The importance of these genes was validated by quantitative real-time PCR. Collectively, our findings indicate that mitochondrial dysfunction may contribute to the damage that occurs to TM cells with a MYOC background under mechanical stretch.
小梁网（TM）通过感知机械拉伸在房水的循环中起着至关重要的作用。房水流出与流入之间的平衡对于调节眼压（IOP）至关重要。功能失调的TM会导致房水流出阻力增加，从而导致眼压升高，这是青光眼的主要危险因素。人们普遍认为，突变型肌纤蛋白（MYOC）会对TM造成损害。然而，很少有研究调查携带突变型MYOC的TM细胞如何应对周期性机械拉伸（CMS），以及在这种遗传背景下这些细胞是否对CMS更敏感。在本研究中，我们使用Flexcell系统对TM细胞施加机械拉伸以模拟生理应激。此外，我们进行了全基因组转录组分析和氧化脂质组学，以系统地比较未拉伸的对照人原发性TM细胞、CMS下的人原发性TM细胞（TM-CMS）以及CMS下过表达MYOC的人原发性TM细胞（S341P-CMS）的基因表达和氧化脂质谱。我们发现过表达MYOC的TM细胞对机械应激更敏感。京都基因与基因组百科全书（KEGG）分析显示，下调的基因在氧化磷酸化中富集最多，表明线粒体功能障碍和氧化应激的可能性。氧化脂质组学分析显示S341P-CMS组和TM-CMS组之间氧化脂质谱有显著变化。通过进一步的全基因组转录组分析，我们鉴定了几个可能参与过表达MYOC的TM细胞对机械应激敏感性的基因，包括 、 、 和 。这些基因的重要性通过定量实时PCR得到验证。总的来说，我们的研究结果表明，线粒体功能障碍可能导致在机械拉伸下具有MYOC背景的TM细胞发生损伤。
