5645
Rehab Selim El- Sayed Abo- Hashem
Submitted for the degree of Ph.D. of Science in Biochemistry As a partial fulfillment for requirements of the Ph.D. of Science
Acute kidney injury, Cisplatin, Losartan, Mesenchymal stem cells, Inflammation, Oxidative stress, Apoptosis, Angiogenisis, Rats.
Acute kidney injury (AKI) is recognized as a rapid loss of kidney functions due to damage of the kidneys, resulting in the retention of the nitrogenous compounds and non- nitrogenous waste products. It is a common disease with a high mortality and morbidity rates. Modern dialysis techniques had no significant impact on overall mortalities caused by AKI. Also, the pharmacological therapies that might improve AKI episode showed unacceptable consequence. Hence, it becomes important to seek on other therapeutic strategies for AKI. Much attention has been paid to the promising outcome of mesenchymal stem cells in the treatment of AKI. The present study was planned to justify the role of bone marrow (BM-MSCs) and adipose-derived mesenchymal stem cells (AD-MSCs) in the treatment of AKI in a rat model and tracing the mechanisms by which they act. MSCs were succefully isolated and characterized morphologically and by the detection of their surface profile. Then, the in vivo study was conducted on adult male Wistar rats (n=90) which were randomized into 9 groups (10 rats each). Group (1): Control, received intraperitoneally a single dose of saline, Group (2): AKI, received a single dose of cisplatin injection i.p (6 mg/kg), Group (3): AKI + losartan, received losartan drug orally (10 mg/kg/day) for two months, Group (4): AKI+ BM-MSCs (1x106 cells/rat), Group (5): AKI+ BM-MSCs (2x106 cells/rat), Group (6): AKI+ BM-MSCs (4x106 cells/rat), Group (7): AKI+ AD-MSCs (1x106 cells/rat), Group (8): AKI+ AD-MSCs (2x106 cells/rat), Group (9): AKI+ AD-MSCs (4x106 cells/rat). The treated groups with MSCs received a single dose of the corresponding number of cells intravenously and were left for two months. Cisplatin administration yielded a significant enhancement in serum (creatinine, urea, cystatin C (Cys C), tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), macrophageinflammatory protein-2 (MIP-2), malondialdehyde (MDA) levels) and urinary (kidney injury molecule-1 (KIM-1), interleukin-18 (IL-18)); paralleled by a significant drop in serum NADPH quinone oxidoreductase-1 (NQO-1), catalase (CAT) and superoxide dismutase (SOD). Moreover, significant up- regulation of p38 mRNA, down- regulation of B- cell lymphoma-2 (Bcl-2) mRNA and vascular endothelial growth factor (VEGF) mRNA in kidney tissue have been recorded in cisplatin injected rats. Mesenchymal stem cells infusion could significantly recover renal functions, suppress the inflammatory markers (TNF-α, MCP-1, MIP-2 and IL-18), promote the anti-oxidant defense system (SOD, CAT and NQO-1) and repress the oxidative stress marker (MDA). Additionally, down- regulation of the pro-apoptotic mediator (p38) and up- regulation of the anti-apoptotic mediator (Bcl-2) as well as proangiogenic factor (VEGF) have been detected in MSCs-treated groups. Furthermore, the histopathological description of kidney tissue sections illustrated that MSCs have a favorable effect on restoring histoarchitecture of kidney as evidenced by the presence of regenerative tubules and minimizing the apoptotic cells as well as the inflammatory cells. Of note, the high dose of MSCs (4x106cells/rat) revealed the suprime effect in the mitigation of AKI in rat model. AD-MSCs in general and in high dose (4x106cells/rat) seem to have a better therapeutic effect than BM-MSCs. Conclusively, suppression of the inflammatory modulators, promotion of the antioxidative response, regulation of apoptotic/ anti-apoptotic balance and induction of angiogenesis may be the underlying mechanisms by which MSCs have made the remarkable achievements in the treatment of AKI.
2019
Ph.d
Ain Shams
Science