Figure 5 A schematic representation of mitophagy-mediated mtDNA release and inflammatory responses in MHD patients with sarcopenia. Mitochondrial dysfunction exists in a subset of patients undergoing hemodialysis. Excessive mitophagy may destroy the mitochondria, causing leakage of mtDNA into the extracellular fluid. mtDNA can be recognized by TLR9 in immune cells. TLR9 interacts with downstream signaling, leading to the transcriptional activation of proinflammatory cytokines. Proinflammatory cytokines then mature and transform into inflammatory cytokines, amplifying the inflammatory cascade, which ultimately results in skeletal muscle inflammation and sarcopenia.