Intra-Arterial Renal Infusion of Bone Marrow-Derived Mesenchymal Stem Cells Inhibits TLR4-NF-κB-NLRP3-Mediated Pyroptosis in Doxorubicin Nephropathy Rats

Abstract

Background: Doxorubicin nephropathy (DRN) is a well-known chronic kidney disease (CHKD) model. Doxorubicin (Dox)-induced nephrotoxicity involves high oxidative stress, apoptosis, and necrosis. However, it is still unclear if Dox causes DRN to undergo pyroptosis (PYT), a particular inflammatory-mediated form of cell death. Bone marrow-derived mesenchymal stem cells (BMMSCs) have therapeutic potential in improving the structure and function of DRN. However, whether BMMSCs regulate PYT in DRN is also not clear. Objective: Our study was to investigate the possibility of BMMSCs in inhibiting TLR4 (toll-like receptor 4)/NF-κB (nuclear factor kappa B)/NLRP3 (nucleotide oligomerization domain (NOD)-like receptors 3) inflammasome-mediated PYT in the DRN rat model. Methods: The rat treatments consisted of four groups (n = 8 rats each): Group A (Nor), normal rats treated with equivalent DMEM (dulbeccos modified eagles medium) medium; Group B (Con), normal rats receiving no treatment; Group C (Dox), DRN rats treated with phosphate buffer; Group D (Dox + BMMSCs). On days 1 and 15, tail vein injections of Dox (4 mg/kg) were used to develop the rat chronic renal disease model (DRN). By the end of week 11, the DRN model was effectively produced, and it had been successfully treated with a single BMMSC injection in the right renal artery through the carotid artery dissection method. By using Western blotting and ELISA (Enzyme-Linked Immunosorbent Assay), the levels of TLR4, NF-κB, NLRP3, Caspase-1, GSDM-D (gasdermin-D), TNF (tumor necrosis factor), MCP-1 (monocyte chemoattractant protein-1), TGF-1 (transforming growth factor 1), α-SMA (α smooth muscle actin), IL-1 (interleukin-1), IL-18, and IL-6 in the kidney tissues of the animals were determined 8 weeks after the second Dox treatment. Results: Our experimental results showed that the levels of TNF-α, MCP-1, TGF-β1, and rats in the BMMSCs treatment (group D) had considerably lower levels of α-SMA than untreated (group C) rats (p < 0.05). Conclusions: In a DRN rat model, Dox could induce pyrogenic cell death, but the mortality was attenuated by treating with BMMSCs. Our results bring new insights into the use of the anti-inflammatory activity of BMMSCs as an effective alternative therapy for CHKD.