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Abstract Background Activation of pericytes leads to renal interstitial fibrosis, but the regulatory mechanism of pericytes in the progression from AKI to CKD remains poorly understood. CD36 activation plays a role in the progression of CKD. However, the significance of CD36 during AKI-CKD, especially in pericyte, remains to be fully defined. Methods GEO and DISCO database were used to analyze the expression of CD36 in pericyte during AKI-CKD; IRI to conduct AKI-CKD mouse model; Hypoxia/Reoxygenation (H/R) to induce the cell model; RT-qPCR and Western blotting to detect gene expression; IP and confocal-IF to determine the core fucosylation (CF) level of CD36. Flow cytometry (AV/PI staining) to detect the cell apoptosis and JC-1 staining to react to the change of mitochondrial membrane potential. Results During AKI to CKD progression, CD36 expression in pericytes is higher and may be influenced by CF. Moreover, we confirmed the positive association of CD36 expression with pericyte-myofibroblast transition and the progression of AKI-CKD in an IRI mouse model and hypoxia/reoxygenation (H/R) pericytes. Notably, we discovered that FUT8 upregulates both CD36 expression and its CF level, contributing to the activation of the mitochondrial-dependent apoptosis signaling pathway in pericytes, ultimately leading to the progression of AKI-CKD. Conclusion These results further identify FUT8 and CD36 as potential targets for the treatment in the progression of AKI-CKD.

Abstract Background Although mesenchymal stem cells (MSCs) have been proven to be appropriate candidates for the treatment of AKI-CKD, their efficacy is limited and variable. Astilbin (AST) had a protective effect on MSCs from oxidative stress via ROS-scavenging, however, whether it can improve MSCs’ renoprotection and the underlying mechanism need to be elucidated. Methods AST-pretreated MSCs were administered intravenously into the ischemia–reperfusion injury mice models and the renal function, pathological changes and inflammation. Were evaluated. In addition, DARTS, molecular docking, surface plasma resonance(SPR), dual-luciferase reporter gene assay and the ChIP-PCR were utilized to explore the potential signaling pathways through which AST exert renal protective effects on MSCs. Results AST-pretreated MSCs markedly improved kidney function, reduced kidney pathological injury and inflammation in AKI and AKI-CKD mice. RNA-seq results showed that PTGS2 related pathway was significantly up-regulated in MSCs after AST pretreatment. DARTS assay, molecular docking and SPR assay revealed that AST could bind with the transcriptional factor of Kruppel-Like Factor 4(KLF4) protein. The promoter of PTGS2 had the binding and transcriptional activation by KLF4. Furthermore, AST pretreatment promoted the secretion of PGE2 in MSCs. And then the westren blot results showed that the protein levels of CD163 and CD206 were upregulated after coculture in AST-pretreated MSCs, indicating that the polarization of RAW264.7 cells towards M2-like macrophages was induced. Knockdown of PTGS2 reversed the ability of AST-pretreated MSCs in converting macrophages to M2 phenotype and reducing their therapeutic effects on AKI-CKD mice. Conclusion AST pretreatment enhances the efficacy of MSCs on AKI and AKI-CKD mice by inducing of M2-like phenotype polarization in macrophages through the PTGS2-mediated pathway. This approach not only provides a novel strategy to strengthen the capability of MSCs but also helps elucidate the beneficial effects of the Chinese herbal medicine AST.

Abstract Background Mesenchymal stem cells (MSCs) have been reported to promote regeneration in both subjects with acute kidney injury (AKI) and chronic kidney disease (CKD), but their efficacy remains limited, probably because most of the cells accumulate in the lungs, liver, and spleen after an intravenous infusion. Therefore, ultrasound-guided administration of MSCs represents a possible approach to solve this problem. The greater omentum is used to promote cell survival due to its rich vasculature. We hypothesized that ultrasound-guided administration of MSCs combined with greater omentum might be more curative than currently available approaches. Methods In this study, we established an aristolochic acid nephropathy (AAN) model by intraperitoneally administering aristolochic acid I sodium salt (AA-I) at a dose of 5 mg/kg body weight on alternate days for 4 weeks. Subsequently, a laparotomy was performed, and the left kidney from which the capsule had been removed was wrapped with the greater omentum. A dose of 2 × 107 MSCs was injected into the space between the greater omentum and the left kidney. Equal amounts of MSCs were administered under ultrasound guidance every second week for a total of 4 treatments. Mice were sacrificed 4 weeks after surgery. Serum creatinine and blood urea levels were measured to assess renal function. qPCR, Western blot, and histological analyses were conducted to further investigate the therapeutic mechanism of MSCs. Results Ultrasound-guided injection of MSCs into the greater omentum that surrounds the kidney enriched cells in the kidney region for up to 5 days. Renal function tests indicated that MSCs improved renal function to a great extent, as reflected by decreased blood urea nitrogen and serum creatinine levels. In addition, histological analyses showed that MSCs noticeably attenuated kidney injury, as evidenced by the amelioration of tubular necrosis and peritubular interstitial fibrosis. Mitigation of renal interstitial fibrosis was further confirmed by immunohistochemistry, qPCR, and western blotting after MSC treatment. Moreover, immunofluorescence staining revealed that MSCs alleviated inflammatory responses by increasing the counts of CD206+ cells and decreasing the counts of CD68+ cells. MSC migration was initiated in response to AA-I-treated renal epithelial cells in an in vitro migration assay. Conclusions These findings suggested that administration of MSCs into the cavity formed by the injured kidney and the greater omentum under ultrasound guidance improved renal function, attenuated kidney injury, and mitigated renal interstitial fibrosis and inflammatory responses. Thus, this approach might be a safe and effective therapy for CKD.