Betaine Modulating MIF-Mediated Oxidative Stress, Inflammation and Fibrogenesis in Thioacetamide-Induced Nephrotoxicity.

Background: Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine with chemokine properties released by various immune and non-immune cells. It contributes to the pathogenesis of many inflammatory, autoimmune diseases and malignant tumors.

Objective: Our study aimed to investigate the role of betaine in the modulation of MIF-mediated oxidative stress, inflammation, and fibrogenesis during toxic kidney damage induced by thioacetamide (TAA).

Methods: The experiment is performed on wild-type and knockout MIF-/- C57BL/6 mice. They are randomly divided into groups: Control; Bet-group, received betaine (2% wt/v dissolved in drinking water); MIF-/- mice group; MIF-/- + Bet; TAA-group, treated with TAA (200 mg/kg b.w.), intraperitoneally, 3x/week/8 weeks); TAA+Bet; MIF-/-+TAA, and MIF-/- + TAA+Bet group. After eight weeks of treatment, animals are sacrificed and kidney samples are taken to determine oxidative stress parameters, proinflammatory cytokines, profibrogenic factors, and histopathology of renal tissue.

Results: In MIF-/-mice, TAA decreases malondialdehyde (MDA) concentration, IL-6, tumor necrosis factor-alpha (TNF-α), transforming growth factor-beta 1 (TGF-β1) and platelet-derived growth factor-BB (PDGF-BB) and increases superoxide dismutases (SOD) and catalase (CAT) activities, as well as glutathione (GSH) content in kidneys, compared to TAA group. Betaine alleviates the mechanism of MIF-mediated effects in TAA-induced nephrotoxicity, reducing MDA, IL-6, TNF-α, TGF-β1, and PDGF-BB, and increasing SOD and CAT activity, as well as GSH levels.

Conclusion: MIF mediates TAA-induced nephrotoxicity by increasing oxidative stress, inflammation, and profibrogenic mediators. MIF-targeted therapy could potentially alleviate oxidative stress and inflammation in the kidney, as well as pathohistological changes in renal tissue, but the exact mechanism of its action is not completely clear. Betaine alleviates MIF nephrotoxic effects by increasing the antioxidative capacity of kidney cells, and decreasing lipid peroxidation and cytokine production in the renal tissue. It suggests that betaine can be used for the prevention of kidney damage.