Oxidative stress due to increased reactive oxygen species (ROS) formation and/or inflammation is considered to play an important role in ischemic stroke injury. Leukemia inhibitory factor (LIF) has been shown to protect both oligodendrocytes and neurons from ischemia by upregulating endogenous anti-oxidants, though the effect of ischemia and the protective role of LIF treatment in mitochondrial function have not been studied. The goal of this study was to determine whether LIF protects ischemia-induced altered mitochondrial bioenergetics in reproductively senescent aged rats of both sexes (≥18 months old), approximately equivalent to the average age of human stroke patients. Animals were euthanized at 3 days after permanent middle cerebral artery occlusion (MCAO) surgery. We found that MCAO surgery significantly reduced mitochondrial oxidative phosphorylation in both the ipsilateral striatum and prefrontal cortex in male aged rats compared to their respective contralateral regions of the brain. MCAO injury showed mitochondrial bioenergetic dysfunction only in the striatum in female rats; however, the prefrontal cortex remained unaffected to the injury. LIF-treated rats significantly prevented mitochondrial dysfunction in the striatum in male rats compared to their vehicle-treated counterparts. Collectively, MCAO-induced mitochondrial dysfunction and LIF’s potential as a therapeutic biomolecule exhibited sex- and tissue-specific effects, varying between the striatum and prefrontal cortex in male and female rats.

Pulmonary fibrosis (PF) is a progressive lung condition characterized by irreversible scarring and high mortality, with limited effective treatments. Mitochondrial dysfunction has emerged as a critical factor in fibroblast activation in PF, although approaches to restore mitochondrial function remain underexplored. The present study investigated whether mitochondrial transfer from alveolar type II epithelial cells (A549) to patient-derived fibroblasts could restore mitochondrial function and bioenergetics. Histological analysis of fibrotic lungs reveals increased collagen deposition and elevated profibrotic markers, accompanied by reduced expression of mitochondrial biogenesis and respiratory proteins compared to non-fibrotic controls, indicating mitochondrial impairment. Freshly isolated donor mitochondria were functionally validated before mitoception using Seahorse analysis and patient-derived fibroblasts were confirmed by qRT-PCR using fibroblast-specific markers. In vitro transfer of mitochondria to diseased patient-derived fibroblasts exhibited a modest, dose and time-dependent increase in mitochondrial membrane potential compared to normal fibroblasts. Gene expression analysis revealed decreased fibrosis-associated markers and increased expression of mitochondrial and antioxidant genes following mitoception. Seahorse analysis after mitoception revealed enhanced ATP-linked respiration and improved selected mitochondrial bioenergetic parameters, whereas maximal respiration and spare respiratory capacity demonstrated variable responses. In contrast, normal fibroblasts displayed minimal changes. Collectively, these findings indicate that mitochondrial transfer modulates fibroblast bioenergetics and profibrotic signaling, supporting its potential as a therapeutic strategy for pulmonary fibrosis.