Adipose-derived mesenchymal stromal cell secretome protects against kidney injury through induction of heme oxygenase 1 upregulation in vitro

BACKGROUND Acute kidney injury is characterized by a sudden decline in renal function, often due to ischemia or nephrotoxins, leading to increased oxidative stress and inflammation. AIM To investigate the protective effects of adipose-derived mesenchymal stromal cell (ADMSC) secretome on renal tubular epithelial cells (NRK-52E) as an in vitro model of oxidative stress-associated kidney injury. METHODS ADMSCs were isolated from human adipose tissue and characterized for mesenchymal markers and differentiation potential. Conditioned media (CM) was collected after 48-hour serum-free culture and applied to serum-deprived NRK-52E cells for 48 hours. Cell viability was assessed using the MTT assay, apoptosis was assessed by Annexin V-FITC/PI staining and flow cytometry, reactive oxygen species (ROS) levels via H2DCFDA staining, and mitochondrial membrane potential by the tetramethylrhodamine ethyl ester assay. The expression of heme oxygenase-1 (HO-1), nuclear factor erythroid 2-related factor 2 (Nrf2), and NAD(P)H quinone dehydrogenase 1 (Nqo1) genes was quantified by quantitative polymerase chain reaction. Comparative transcriptomic analysis was performed on ADMSCs and bone marrow-derived MSCs (BM-MSCs) using publicly available microarray data (GSE108511). RESULTS ADMSC secretome significantly reduced ROS production and enhanced mitochondrial membrane potential in NRK cells. Gene expression analysis revealed a significant upregulation of HO-1 mRNA levels in ADMSC-CM treated cells. However, no significant changes were observed in Nrf2 and Nqo1 mRNA levels. Transcriptome analysis of ADMSCs against BM-MSCs revealed significant differences in the expression of genes related to oxidative stress response, antioxidant activity, and mitochondrial function. CONCLUSION The results of this study suggest that the ADMSC secretome exerts multifaceted protective effects on NRK cells by reducing oxidative stress and enhancing mitochondrial function. The study demonstrates the potential beneficial applications of the ADMSC secretome in treating oxidative stress-related kidney injuries.