Abstract: SA-PO134
Mitochondrial Treatment Mitigates Hypoxia-Induced Renal Cell Injury
Session Information
- AKI: Metabolism and Cell Death
October 26, 2024 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Acute Kidney Injury
- 103 AKI: Mechanisms
Authors
- Maquigussa, Edgar, Universidade Federal de Sao Paulo, Sao Paulo, São Paulo, Brazil
- Bronel, Bruno Santos, Universidade Federal de Sao Paulo, Sao Paulo, São Paulo, Brazil
- Boim, Mirian A., Universidade Federal de Sao Paulo, Sao Paulo, São Paulo, Brazil
Background
Renal ischemia promotes renal hypoperfusion and hypoxia, leading to tubular epithelial damage, infiltration of inflammatory cells, and activation of pro-fibrotic pathways. Mitochondrial dysfunction plays a central role in cellular alterations induced by hypoxia. Mitochondria and their components can be secreted by cells and are found in the extracellular fluid in various forms: functional mitochondria, mitochondrial DNA, and mitochondrial vesicles. These mitochondrial components regulate cell metabolism, inflammation, and oxidative stress. Therefore, this study aimed to evaluate the role of mitochondria in an in vitro model of renal hypoxia.
Methods
Proximal tubular epithelial cells (mm55K) were cultured in normoxia (95% atmosphere air and 5% CO2) or hypoxia (94% N2, 5% CO2 and 1% O2) environment. The hypoxic stimulus length was previously determined using lactate levels by ELISA. Mitochondria were isolated from mm55K cells cultured in normoxia and hypoxia conditions and evaluated by flow cytometry and mitotracker-labeled. The mm55K cells cultured in normoxia or hypoxia were treated with either mitochondria isolated from normoxia or hypoxia conditions. The ability of mm55K cells to incorporate mitotracker-labeled mitochondria was evaluated by fluorescence microscopy. The gene expression of extracellular matrix markers (fibronectin, collagen IV, vimentin, and TGF-β), inflammation (p50 and p65), oxidative stress (NOX4, SOD-1, and UCP2), and apoptosis (caspase-3 and caspase-9) was assessed by RT-PCR.
Results
Hypoxia increased lactate concentration at 24, 48, and 72 hours in mm55K cells. There were no differences in the quantity of isolated mitochondria between the groups. Mitochondria stained with mitotracker were observed in the cytoplasm of mm55K cells, demonstrating the internalization of the isolated mitochondria by these cells. Under hypoxic stimulation, the gene expression of extracellular matrix markers, inflammation, oxidative stress, and apoptosis significantly increased. However, the effects on gene expression were attenuated with mitochondria treatment from both normoxia and hypoxia conditions.
Conclusion
Isolated mitochondria have a potential therapeutic role in reversing key markers in an in vitro model of cell injury caused by hypoxia.