Singh Shivendra, Patel Niketa A, Soundararajan Avinash, Pattabiraman Padmanabhan P
Indiana University School of Medicine.
JA Haley Veterans Hospital.
Res Sq. 2024 Dec 24:rs.3.rs-5690041. doi: 10.21203/rs.3.rs-5690041/v1.
Glaucoma is a leading cause of irreversible blindness, often associated with elevated intraocular pressure (IOP) due to trabecular meshwork (TM) dysfunction. Diabetes mellitus (DM) is recognized as a significant risk factor for glaucoma; however, the molecular mechanisms through which hyperglycemia affects TM function remain unclear. This study investigated the impact of high glucose on gene expression in human TM (HTM) cells to uncover pathways that contribute to TM dysfunction and glaucoma pathogenesis under diabetic conditions. Primary HTM cells were cultured under normoglycemic (5.5 mM) and hyperglycemic (30 mM) conditions for seven days, followed by mRNA sequencing (mRNA-seq) to identify differentially expressed genes, with quantitative PCR (qPCR) used for confirmatory analysis. STRING network analysis was performed to predict interactions among upregulated and downregulated proteins. mRNA-seq analysis revealed 25 significantly differentially expressed genes in high glucose conditions, including upregulated genes associated with oxidative stress, apoptosis, autophagy, immune response, and fibrosis. Notably, TXNIP was significantly upregulated, indicating increased oxidative stress and apoptosis in TM cells, while downregulation of autophagy-related genes, such as HSPA6 and LAMP3, suggests compromised protein quality control. Immune response genes, including CCL7 and CHI3L1, were upregulated, suggesting an inflammatory response to oxidative stress. Increased expression of fibrosis-related genes, such as SNAI1, FGF7, and KRT19, supports the hypothesis of ECM accumulation in diabetic conditions, potentially elevating IOP. Chronic hyperglycemia in diabetic patients could therefore lead to TM dysfunction, impair aqueous humor outflow, and elevate IOP, thereby increasing glaucoma risk. Targeting oxidative stress and fibrosis pathways offers therapeutic strategies to mitigate glaucoma progression in diabetic populations.
青光眼是不可逆失明的主要原因，通常与小梁网（TM）功能障碍导致的眼内压（IOP）升高有关。糖尿病（DM）被认为是青光眼的一个重要危险因素；然而，高血糖影响TM功能的分子机制仍不清楚。本研究调查了高糖对人TM（HTM）细胞基因表达的影响，以揭示在糖尿病条件下导致TM功能障碍和青光眼发病机制的途径。将原代HTM细胞在正常血糖（5.5 mM）和高血糖（30 mM）条件下培养7天，然后进行mRNA测序（mRNA-seq）以鉴定差异表达基因，并使用定量PCR（qPCR）进行验证分析。进行STRING网络分析以预测上调和下调蛋白质之间的相互作用。mRNA-seq分析显示在高糖条件下有25个显著差异表达基因，包括与氧化应激、细胞凋亡、自噬、免疫反应和纤维化相关的上调基因。值得注意的是，TXNIP显著上调，表明TM细胞中的氧化应激和细胞凋亡增加，而自噬相关基因如HSPA6和LAMP3的下调表明蛋白质质量控制受损。免疫反应基因，包括CCL7和CHI3L1，上调，表明对氧化应激有炎症反应。纤维化相关基因如SNAI1、FGF7和KRT19的表达增加支持了糖尿病条件下细胞外基质积累的假说，这可能会升高IOP。因此，糖尿病患者的慢性高血糖可能导致TM功能障碍、房水流出受损和IOP升高，从而增加青光眼风险。针对氧化应激和纤维化途径提供了减轻糖尿病患者青光眼进展的治疗策略。
