*Purpose: Ischemia induces altered bioenergetics within cells with increased mitochondrial swelling and reactive oxygen species and that ultimately degrade of cellular function. Ischemia reperfusion injury IRI induces mitochondrial fragmentation resulting in cell death and injury. Additionally, energetically related injuries are worse in metabolically stressed tissues such as steatotic liver, making them more susceptible to ischemia. Therapeutic interventions that target to improve mitochondrial health to repair, reprogram or replace mitochondria to restore respiratory functions are beneficial for prevention of disease.

*Methods: In Vivo studies: Liver injury was assessed by serum alanine aminotransferase (ALT; mU/ml) after 60 mins of ischemia and 24 hrs of reperfusion. 20-wk old C57BL/6 (lean and diet induced obese, DIO) mice were i.v. injected with Mitochondria (Mito), isolated from healthy mouse liver (Mito; 50 mcg protein equivalent) 1 day before (-1d) or at time of reperfusion (@R). Along with functional (ALT), histological (H&E) and molecular (RTPCR) analysis were done. In Vitro studies: Huh7 and HepG2 human hepatocytes cell lines were used to evaluate uptake and therapeutic use of mitochondria using Seahorse analyzer. Palmitic and Oleic, PA/OA were used to induce lipid accumulation in hepatocytes to mimic steatotic liver. Mitochondria for in vitro studies were isolated from human (HEK293) cells.

*Results: DIO mice had significantly worse liver function compared to lean mice after IRI (ALT: 4090±236 vs 10308±304, p<0.001). Mito (-1d or @R) treated lean (ALT: -1d, 2288±157; @R, 1548±134, p<0.01) and DIO (ALT: -1d, 6811±656; @R, 2201±183, p<0.001) mice were significantly protected compared to vehicle treated mice after IRI. Mice treated with mitochondria had higher liver gene expression of Pgc1a and lower levels of proinflammatory cytokines like (Tnfa and Il1b) compared to vehicle treated mice. Histology of Mito treated mice had lower Suzuki score. Mito treated cells had significantly higher levels of extra- and intracellular ATP, higher basal oxygen consumption rate (OCR) and spare respiratory capacity measured by seahorse analyzer.

*Conclusions: Our data demonstrates that treatment with healthy mitochondria enhances recipient cells energy production to help replace damaged mitochondria by inducing Pgc1a to rescue cellular functions. Our current study demonstrates that treatment with healthy mitochondria can be used as therapeutic modality for treatment and/or prevention of liver IRI.

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