The assessment of the therapeutic effects of allogeneic human mesenchymal stem cell exosomes on ischemic acute kidney injury model constituting three dimensional microfluidic proximal tubule-on-a-chip platform

Cam SB, The Assessment Of The Therapeutic Effects of Allogeneic Human Mesenchymal Stem Cell Exosomes on Ischemic Acute Kidney Injury Model Constituting Three Dimensional Microfluidic Proximal Tubule-On-A-Chip Platform, Hacettepe University Faculty of Medicine Department of Histology and Embryology Residency Thesis, Ankara, 2022. Ischemic acute kidney injury (AKI) with high chronicity risk and mortality requires real-time personalized models to transfer cellular therapies to the clinic. The therapeutic efficacy of human bone marrow mesenchymal stem cell (BM-MSC) exosomes in hypoxic proximal tubule epithelium (PTE) injury can be demonstrated in a three-dimensional (3D) dynamic microfluidic platform. ZO-1 and acetylated α-tubulin immunoreactivity, dextran permeability, cell proliferation rate, BNIP3, HO-1, HIF1α, GLUT1 and GLUT2 gene expressions were evaluated in human PTE cells in acute hypoxic microfluidic setup; The efficacy of human BM-MSC exosomes, whose proliferative treatment window was determined, in hypoxic damage at ED50 was evaluated by applying them on the optimized 3D microfluidic platform. Microfluidic chip setup was optimized for acute hypoxia-induced PTE injury. The real-time treatment window of characterized allogeneic BM-MSC exosomes was determined as 172.582 µg/ml and 0-26 hours; exosomes at ED50 alleviated the acute hypoxic PTE injury by correcting the barrier integrity, increasing ZO-1 immunolabeling, increasing PTE cell numbers, decreasing BNIP3 expression; increasing HO-1, HIF1α, GLUT1 and GLUT2 expressions at 24 hours in the microfluidic chip. In the hypoxic 3D microfluidic PTE platform optimized within the scope of the thesis, the efficacy of allogeneic BM-MSC exosomes in the treatment window was demonstrated in terms of structure and function. The new ex vivo system is important as it validates personalized therapeutic candidates to be applied in the nephrology clinic.