Muscle-Derived Mitochondrial Transplantation Reduces Inflammation, Enhances Bacterial Clearance, and Improves Survival in Sepsis

Background: Mitochondrial transplantation is a promising strategy for the treatment of several diseases. However, the effects of mitochondrial transplantation on the outcome of polymicrobial sepsis remain unclear. Methods: The distribution of transplanted mitochondria in cecal ligation and puncture (CLP)-operated mice was detected at 2 and 12 h after intravenous injection in the tail (n = 3). Then, the effects of mitochondrial transplantation on bacterial clearance (n = 7), systemic inflammation (n = 10), organ injury (n = 8), and mortality (n = 19) during CLP-induced sepsis were explored. Microarray analysis (n = 3) was used to testify the molecular changes associated with decreased systemic inflammation and multiorgan dysfunction in sepsis. Results: The extraneous mitochondria were distributed in the lung, liver, kidney, and brain of CLP-operated mice at 2 and 12 h after intravenous injection in the tail. Mitochondrial transplantation increased the survival rate of septic mice, which was associated with decreased bacterial burden, systemic inflammation, and organ injury. Spleen samples were utilized for microarray analysis. Pathway analysis revealed that in polymicrobial sepsis, gene expression was significantly changed in processes related to inflammatory response, complement and coagulation cascades, and rejection reaction. Conclusions: These data displayed that mitochondrial replenishment reduces systemic inflammation and organ injury, enhances bacterial clearance, and improves the survival rate in sepsis. Thus, extraneous mitochondrial replenishment may be an effective adjunctive treatment to reduce sepsis-related mortality.