Disrupted mitochondrial transcription factor A expression promotes mitochondrial dysfunction and enhances ocular surface inflammation by activating the absent in melanoma 2 inflammasome

作者：Yaqiong Li, Lei Tian, Siyuan Li, Xiaoniao Chen, Fengyang Lei, Jiayu Bao, Qianru Wu, Ya Wen, Ying Jie · 发表于：Free Radical Biology and Medicine · 年份：2024 · DOI：10.1016/j.freeradbiomed.2024.05.032 · 被引用次数：39 · 研究领域：Inflammasome and immune disorders、Ocular Surface and Contact Lens、Advanced Glycation End Products research

PURPOSE: Severe dry eye disease causes ocular surface damage, which is highly associated with mitochondrial dysfunction. Mitochondrial transcription factor A (TFAM) is essential for packaging mitochondrial DNA (mtDNA) and is crucial for maintaining mitochondrial function. Herein, we aimed to explore the effect of a decreased TFAM expression on ocular surface damage. METHODS: Female C57BL/6 mice were induced ocular surface injury by topical administrating benzalkonium chloride (BAC). Immortalized human corneal epithelial cells (HCECs) were stimulated by tert-butyl hydroperoxide (t-BHP) to create oxidative stress damage. HCECs with TFAM knockdown were established. RNA sequencing was employed to analyze the whole-genome expression. Mitochondrial changes were measured by transmission electron microscopy, Seahorse metabolic flux analysis, mitochondrial membrane potential, and mtDNA copy number. TFAM expression and inflammatory cytokines were determined using RT-qPCR, immunohistochemistry, immunofluorescence, and immunoblotting. RESULTS: In both the corneas of BAC-treated mice and t-BHP-induced HCECs, we observed impaired TFAM expression, accompanied by mitochondrial structure and function defects. TFAM downregulation in HCECs suppressed mitochondrial respiratory capacity, reduced mtDNA content, induced mtDNA leakage into the cytoplasm, and led to inflammation. RNA sequencing revealed the absent in melanoma 2 (AIM2) inflammasome was activated in the corneas of BAC-treated mice. The...