Mitochondrial oxidative stress regulates LonP1-TDP-43 pathway and rises mitochondrial damage in carbon tetrachloride-induced liver fibrosis

Carbon tetrachloride (CCl₄)-mediated liver damage has been well recognized, but the sources and mechanisms of mitochondrial damage during this progress still remain poorly understood. Accumulating evidence has revealed that LonP1-TDP-43 pathway affect proper mitochondrial integrity and function in neurodegenerative diseases. The current study aims to investigate whether mitochondrial oxidative stress regulate LonP1-TDP-43 pathway and the possible roles of this pathway in CCl₄-driven liver fibrosis. We found that TDP-43 interacted with LonP1 in chronic CCl₄ exposure-induced hepatic fibrogenesis. Moreover, CCl₄ led to deficiency of LonP1 and excessive accumulation of TDP-43 on mitochondria. Particularly, the gene correlation analysis for liver fibrosis patients RNA Sequencing (RNA-seq) results (GSE159676) showed an obvious negative correlation between LonP1 and TDP-43. By contrast, MitoQ enhanced the occurrence of mitochondrial unfolded protein response (mtUPR), especially the activation of LonP1 after CCl₄ treatment. Importantly, mitochondrial antioxidant also promoted the degradation of TDP-43 and alleviated mitochondrial damage. In addition, our results showed that CCl₄ induced the release of mitochondrial DNA (mtDNA) and effectively elevated cGAS-STING-mediated immune response, which can be inhibited by MitoQ. Finally, MitoQ prevented CCl₄-induced liver fibrosis. Together, our study revealed that LonP1-TDP-43 pathway mediated by mitochondrial oxidative stress participated in the progress of CCl₄-drived liver fibrosis. Therefore, mitigating or reversing mitochondrial damage through targeting LonP1-TDP-43 pathway may serve as a promising therapeutic strategy for CCl₄ exposure-induced liver diseases.