Comprehensive Pan-Cancer Analysis of Connexin 43 as a Potential Biomarker and Therapeutic Target in Human Kidney Renal Clear Cell Carcinoma (KIRC).

Background and Objectives: Connexin 43 (Cx43) is involved in the transfer of small signaling molecules between neighboring cells, thereby exerting a major influence on the initiation and progression of tumorigenesis. However, there is a lack of systematic research on Cx43 expression and its predictive role in clinical diagnosis and prognosis in pan-cancer. Materials and Methods: Several biological databases were used to evaluate the expression levels of GJA1 (encoding Cx43) and its diagnostic and prognostic significance in pan-cancer. We targeted kidney renal clear cell carcinoma (KIRC) and investigated the relationship between GJA1 expression and different clinical features of KIRC patients. Then, we performed cell-based experiments to partially confirm our results and predicted several proteins that were functionally related to Cx43. Results: The expression of GJA1 has a high level of accuracy in predicting KIRC. High GJA1 expression was remarkably correlated with a favorable prognosis, and this expression was reduced in groups with poor clinical features in KIRC. Cell experiments confirmed the inhibitory effects of increased GJA1 expression on the migratory capacity of human renal cancer (RCC) cell lines, and protein-protein interaction (PPI) analysis predicted that CDH1 and CTNNB1 were closely related to Cx43. Conclusions: GJA1 could be a promising independent favorable prognostic factor for KIRC, and upregulation of GJA1 expression could inhibit the migratory capacity of renal cancer cells.

Saccharomyces boulardii protects against murine experimental colitis by reshaping the gut microbiome and its metabolic profile.

Introduction: Saccharomyces boulardii (S. boulardii) has shown clinical beneficial effect in inflammatory bowel diseases recently. However, the underlying mechanisms remain incompletely understood. The aim of present study was to tested whether S. boulardii targets gut microbiota to protect against the development of experimental colitis in mice. Methods: Female C57BL/6 mice were gavaged with S. boulardii for 3 weeks before being challenged with dextran sulphate sodium to induce ulcerative colitis. Bodyweight, diarrhea severity, intestinal permeability, colonic histopathology, colonic inflammatory status, and epithelial cell death of mice were examined. The fecal microbiota and its metabolomic profiles were detected by 16S rDNA sequencing and UPLC-MS, respectively. Results and Discussion: Supplementation with S. boulardii significantly prevented weight loss and colon shortening, lowered colonic inflammation, ameliorated epithelial injury, and enhanced the intestinal barrier integrity in colitis mice. By inhibiting the abundance of pathogenic bacteria and increasing the probiotics abundance, S. boulardii improved the microbial diversity and restored the microbiota dysbiosis. Moreover, it also modulated microbial metabolome and altered the relative contents of metabolites involving amino acids, lipids, energy and vitamin metabolisms. These yeast-driven shifts in gut flora and metabolites are were associated with each other and with the inflammation profile in colitis. Collectively, S. boulardii exerts protective effects on colitis in mice by reshaping gut microbiome and its metabolic profile, indicating it as a promising therapeutic avenue.

Cytoplasmic HMGB1 induces renal tubular ferroptosis after ischemia/reperfusion.

As a damage-associated molecular pattern molecule, high-mobility group box 1 (HMGB1) is well-studied and is released from injured tubular epithelial cells to trigger cell death. However, the role of intracellular HMGB1 induced cell death during acute kidney injury (AKI) is poorly understood. We showed that cytosolic HMGB1 induced ferroptosis by binding to acyl-CoA synthetase long-chain family member 4 (ACSL4), the driver of ferroptosis, following renal ischemia/reperfusion (I/R). Both mouse and human kidneys with acute tubular injury were characterized by nucleocytoplasmic translocation of HMGB1in tubular cells. Pharmacological inhibition of HMGB1 nucleocytoplasmic translocation and deletion of HMGB1 in tubular epithelial cells in mice inhibited I/R-induced AKI, tubular ferroptosis, and inflammation compared to those in controls. Co-immunoprecipitation and serial section staining confirmed the interaction between HMGB1 and ACSL4. Taken together, our results demonstrated that cytoplasmic HMGB1 is essential for exacerbating inflammation-associated cellular injury by activating renal tubular ferroptosis via ACSL4 after I/R injury. These findings indicate that cytoplasmic HMGB1 is a regulator of ferroptosis and a promising therapeutic target for AKI.

Blocking connexin 43 and its promotion of ATP release from renal tubular epithelial cells ameliorates renal fibrosis.

Whether metabolites derived from injured renal tubular epithelial cells (TECs) participate in renal fibrosis is poorly explored. After TEC injury, various metabolites are released and among the most potent is adenosine triphosphate (ATP), which is released via ATP-permeable channels. In these hemichannels, connexin 43 (Cx43) is the most common member. However, its role in renal interstitial fibrosis (RIF) has not been fully examined. We analyzed renal samples from patients with obstructive nephropathy and mice with unilateral ureteral obstruction (UUO). Cx43-KSP mice were generated to deplete Cx43 in TECs. Through transcriptomics, metabolomics, and single-cell sequencing multi-omics analysis, the relationship among tubular Cx43, ATP, and macrophages in renal fibrosis was explored. The expression of Cx43 in TECs was upregulated in both patients and mice with obstructive nephropathy. Knockdown of Cx43 in TECs or using Cx43-specific inhibitors reduced UUO-induced inflammation and fibrosis in mice. Single-cell RNA sequencing showed that ATP specific receptors, including P2rx4 and P2rx7, were distributed mainly on macrophages. We found that P2rx4- or P2rx7-positive macrophages underwent pyroptosis after UUO, and in vitro ATP directly induced pyroptosis by macrophages. The administration of P2 receptor or P2X7 receptor blockers to UUO mice inhibited macrophage pyroptosis and demonstrated a similar degree of renoprotection as Cx43 genetic depletion. Further, we found that GAP 26 (a Cx43 hemichannel inhibitor) and A-839977 (an inhibitor of the pyroptosis receptor) alleviated UUO-induced fibrosis, while BzATP (the agonist of pyroptosis receptor) exacerbated fibrosis. Single-cell sequencing demonstrated that the pyroptotic macrophages upregulated the release of CXCL10, which activated intrarenal fibroblasts. Cx43 mediates the release of ATP from TECs during renal injury, inducing peritubular macrophage pyroptosis, which subsequently leads to the release of CXCL10 and activation of intrarenal fibroblasts and acceleration of renal fibrosis.

Combination of ultra-low dose rituximab and low dose tacrolimus versus tacrolimus alone in the treatment of non-responsive idiopathic membranous nephropathy: a Chinese retrospective cohort study.

INTRODUCTION: Some patients with idiopathic membranous nephropathy (iMN) do not respond to cyclophosphamide plus steroids treatment, and we define them as non-responsive iMN. The combined regimen of rituximab (RTX) and tacrolimus (TAC) has an excellent effect on this kind of non-responsive iMN patients; however, the optimal dose is still unclear. In this retrospective study, we comapred the efficacy and safety of ultra-low dose RTX plus low-dose TAC therapy versus standard TAC monotherapy in patients with non-responsive iMN. MATERIALS AND METHODS: Sixty-seven Chinese non-responsive iMN patients were included. There were 41 patients received standard tacrolimus monotherapy (TAC) and 26 patients received ultra-low dose rituximab plus low dose tacrolimus (RTX/TAC) combination therapy. All patients were observed for 12 months. RESULTS: 18 patients (18/26, 69.2%) in the RTX/TAC group and 17 patients (17/41, 41.5%) in the TAC group achieved clinical response after 12-month follow-up (P=0.044). The median time for achieving response in the two groups was 3.0 months. As indicated by Kaplan-Meier curve, the response rate in the RTX/TAC group was higher than that in the TAC group (P=0.015). 24-hour proteinuria, serum albumin, estimated glomerular filtration rate (eGFR) and serum creatinine in the two groups were comparable at baseline; howerver, after 12-month follow up, they were significantly improved in the RTX/TAC group compared with the TAC group (P<0.05). B-cell depletion was achieved in all patients in the RTX/TAC group during the whole follow-up period. Pneumonia, urinary tract infections and glucose intolerance were the major side effects observed in this study. All adverse events were mild, and the cumulative incidence was lower in the RTX/TAC group compared with that in the TAC group (9 (34.6%) vs 27 (65.9%), P=0.023). CONCLUSION: The combination of ultra-low dose rituximab and low dose tacrolimus is more effective in inducing proteinuria response, improving eGFR and serum albumin in non-responsive iMN patients than standard tacrolimus monotherapy. The combined treatment also has higher safty.

Saccharomyces boulardii Ameliorates Dextran Sulfate Sodium-Induced Ulcerative Colitis in Mice by Regulating NF-κB and Nrf2 Signaling Pathways.

Saccharomyces boulardii (S. boulardii) is a probiotic yeast that is widely used to treat gastrointestinal disorders. The present study is aimed to explore the therapeutic effects of S. boulardii on dextran sulfate sodium- (DSS-) induced murine ulcerative colitis (UC) and illustrate the mechanisms of action. C57BL/6 mice were administered S. boulardii (105 and 107 CFU/ml, p.o.) for 3 weeks and then given DSS [2.5% (w/v)] for one week. Administration of S. boulardii prevented DSS-induced reduction in body weight, diarrhea, bloody feces, decreased colon length, and loss of histological structure. Moreover, S. boulardii protected the intestinal barrier by increasing the levels of tight junction proteins zona occludens-1 and Occludin and exerted immunomodulatory effects in DSS-induced mice. Furthermore, S. boulardii suppressed the colonic inflammation by reducing the levels of Interleukin-1ß, Interleukin-6, and Tumor necrosis factor alpha and restored myeloperoxidase activity in mice exposed to DSS. S. boulardii also mitigated colonic oxidative damage by increasing the levels of antioxidant enzymes (superoxide dismutase, catalase, and heme oxygenase 1) and glutathione and decreasing malondialdehyde accumulation. Further studies identified that S. boulardii suppressed the nuclear translocation of nuclear factor kappa B (NF-κB) p65 subunit by decreasing IκKα/ß levels, while promoted the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) in DSS-exposed mice. Collectively, S. boulardii possessed an appreciable therapeutic effect against the experimental mice model of UC. The protective mechanism of S. boulardii may involve inhibition of NF-κB-mediated proinflammatory signaling and activation of Nrf2-modulated antioxidant defense in addition to intestinal barrier protective and immunomodulatory effects.

The probiotic L. casei Zhang slows the progression of acute and chronic kidney disease.

The relationship between gut microbial dysbiosis and acute or chronic kidney disease (CKD) is still unclear. Here, we show that oral administration of the probiotic Lactobacillus casei Zhang (L. casei Zhang) corrected bilateral renal ischemia-reperfusion (I/R)-induced gut microbial dysbiosis, alleviated kidney injury, and delayed its progression to CKD in mice. L. casei Zhang elevated the levels of short-chain fatty acids (SCFAs) and nicotinamide in the serum and kidney, resulting in reduced renal inflammation and damage to renal tubular epithelial cells. We also performed a 1-year phase 1 placebo-controlled study of oral L. casei Zhang use (Chinese clinical trial registry, ChiCTR-INR-17013952), which was well tolerated and slowed the decline of kidney function in individuals with stage 3-5 CKD. These results show that oral administration of L. casei Zhang, by altering SCFAs and nicotinamide metabolism, is a potential therapy to mitigate kidney injury and slow the progression of renal decline.

Separated parabiont reveals the fate and lifespan of peripheral-derived immune cells in normal and ischaemia-induced injured kidneys.

Immune cell infiltration plays a key role in acute kidney injury (AKI) to chronic kidney disease (CKD) progression. T lymphocytes, neutrophils, monocytes/macrophages and other immune cells regulate inflammation, tissue remodelling and repair. To determine the kinetics of accumulation of various immune cell populations, we established an animal model combining parabiosis and separation surgery to explore the fate and lifespan of peripheral leucocytes that migrate to the kidney. We found that peripheral T lymphocytes could survive for a long time (more than 14 days), whereas peripheral neutrophils survived for a short time in both healthy and ischaemia-induced damaged kidneys. Nearly half of the peripheral-derived macrophages disappeared after 14 days in normal kidneys, while their existing time in the inflammatory kidneys was prolonged. A fraction of F4/80high macrophages were renewed from the circulating monocyte pool. In addition, we found that after renal ischaemia reperfusion, neutrophils increased significantly in the early phase, and T lymphocytes mainly accumulated in the late stage, whereas macrophages infiltrated throughout AKI-CKD progression and were sustained longer in injured as opposed to normal kidneys. In conclusion, peripheral-derived macrophages, T lymphocytes and neutrophils exhibit different lifespans in the kidney, which may play different roles during AKI-CKD progression.

Exogenous bone marrow derived-putative endothelial progenitor cells attenuate ischemia reperfusion-induced vascular injury and renal fibrosis in mice dependent on pericytes.

Rationale: Capillaries are composed of endothelial cells and the surrounding mural cells, pericytes. Microvascular repair after injury involves not only the proliferation of endothelial cells but also pericyte-based vessel stabilization. Exogenous bone marrow derived-putative endothelial progenitor cells (b-pEPCs) have the potential for vascular repair; however, their effect on vascular structure stabilization and pericyte-related pathobiological outcomes in the injured kidney has not been fully examined. Methods: We applied ischemia-reperfusion (IR) to induce renal vascular injury and renal fibrosis in mice. Platelet-derived growth factor receptor ß (PDGFR-ß)-DTR-positive mice were generated to deplete pericytes, and exogenous b-pEPCs and the PDGFR-ß ligand, PDGF chain B (PDGF-BB), were employed to explore the relationship among b-pEPCs, pericytes, vascular repair, and early renal fibrosis. Results: Administration of b-pEPCs reduced IR-induced pericyte-endothelial detachment, pericyte proliferation, and myofibroblast transition via a paracrine mode, which preserved not only vascular stabilization but also ameliorated IR-initiated renal fibrosis. PDGF-BB upregulated the expression of PDGFR-ß, exacerbated vascular abnormality, and pericyte-myofibroblast transition, which were ameliorated by b-pEPCs administration. The exogenous b-pEPCs and their culture medium (CM) induced vascular injury protection, and renal fibrosis was blocked by selective deletion of pericytes. Conclusion: Exogenous b-pEPCs directly protect against IR-induced vascular injury and prevent renal fibrosis by inhibiting the activation of PDGFR-ß-positive pericytes.

XJB-5-131 inhibited ferroptosis in tubular epithelial cells after ischemia-reperfusion injury.

Regulated necrosis has been reported to exert an important role in the pathogenesis of various diseases, including renal ischemia-reperfusion (I/R) injury. Damage to renal tubular epithelial cells and subsequent cell death initiate the progression of acute kidney injury (AKI) and subsequent chronic kidney disease (CKD). We found that ferroptosis appeared in tubular epithelial cells (TECs) of various human kidney diseases and the upregulation of tubular proferroptotic gene ACSL4 was correlated with renal function in patients with acute kidney tubular injury. XJB-5-131, which showed high affinity for TECs, attenuated I/R-induced renal injury and inflammation in mice by specifically inhibiting ferroptosis rather than necroptosis and pyroptosis. Single-cell RNA sequencing (scRNA-seq) indicated that ferroptosis-related genes were mainly expressed in tubular epithelial cells after I/R injury, while few necroptosis- and pyroptosis-associated genes were identified to express in this cluster of cell. Taken together, ferroptosis plays an important role in renal tubular injury and the inhibition of ferroptosis by XJB-5-131 is a promising therapeutic strategy for protection against renal tubular cell injury in kidney diseases.

Association of plasma macrophage colony-stimulating factor with cardiovascular morbidity and all-cause mortality in chronic hemodialysis patients.

BACKGROUND: Cardiovascular disease (CVD) events are the main cause of death in long-term hemodialysis (HD) patients. Macrophage colony- stimulating factor (M-CSF) is actively involved in the formation of atherosclerosis and causes plaque instability, thrombosis and the development of acute coronary syndromes. However, little information is available on the role of M-CSF in HD patients. We aimed to investigate the association between plasma M-CSF levels and CVD events as well as all-cause mortality in patients undergoing long-term HD. METHODS: Fifty two HD patients and 8 healthy controls were recruited in this study. HD patients were followed up from September 2014 to May 2017. The primary end point was CVD event, the secondary outcome was death from any cause. Patients were divided into two groups with low and high M-CSF levels based on the optimal cut-off value determined by the ROC curve. Cox regression analyses were used to assess the predictive value of plasma M-CSF for CVD events and all-cause mortality in HD patients. We tested the levels of plasma M-CSF and other inflammatory cytokines in surviving HD patients using ELISA or CBA kit. RESULTS: The average plasma level of M-CSF in 52 patients was approximately twice that of healthy controls (992.4 vs. 427.2 pg/mL; p <  0.05). During 32 months of follow-up, 26 patients (50.0%) had at least one CVD event and 8 patients (15.4%) died. The mean plasma M-CSF concentration increased in survivors after follow-up compared to that detected at baseline (1277.8 ± 693.3 vs. 997.2 ± 417.4 pg/mL; p <  0.05). Multivariate Cox regression analysis showed that plasma M-CSF is an independent risk factor for CVD events in HD patients (p <  0.05). In the Cox regression model after adjusting for gender and age, high M-CSF levels were related to an increased risk of all-cause death (p <  0.05). We also found that M-CSF levels were positively correlated with IL-6 and IL-18 levels (both p < 0.05), which are the major pathogentic cytokines that contribute to HD-related CVD events. CONCLUSION: M-CSF is a prognostic factor for CVD events and all-cause mortality in HD patients.

Compound α-keto acid tablet supplementation alleviates chronic kidney disease progression via inhibition of the NF-kB and MAPK pathways.

BACKGROUND: Keto-analogues administration plays an important role in clinical chronic kidney disease (CKD) adjunctive therapy, however previous studies on their reno-protective effect mainly focused on kidney pathological changes induced by nephrectomy. This study was designed to explore the currently understudied alternative mechanisms by which compound α-ketoacid tablets (KA) influenced ischemia-reperfusion (IR) induced murine renal injury, and to probe the current status of KA administration on staving CKD progression in Chinese CKD patients at different stages. METHODS: In animal experiment, IR surgery was performed to mimic progressive chronic kidney injury, while KA was administrated orally. For clinical research, a retrospective cohort study was conducted to delineate the usage and effects of KA on attenuating CKD exacerbation. End-point CKD event was defined as 50% reduction of initial estimated glomerular filtration rate (eGFR). Kaplan-Meier analysis and COX proportional hazard regression model were adopted to calculate the cumulative probability to reach the end-point and hazard ratio of renal function deterioration. RESULTS: In animal study, KA presented a protective effect on IR induced renal injury and fibrosis by attenuating inflammatory infiltration and apoptosis via inhibition of nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways. In clinical research, after adjusting basic demographic factors, patients at stages 4 and 5 in KA group presented a much delayed and slower incidence of eGFR decrease compared to those in No-KA group (hazard ratio (HR) = 0.115, 95% confidence interval (CI) 0.021-0.639, p = 0.0134), demonstrating a positive effect of KA on staving CKD progression. CONCLUSION: KA improved IR induced chronic renal injury and fibrosis, and seemed to be a prospective protective factor in end stage renal disease.

Putative endothelial progenitor cells do not promote vascular repair but attenuate pericyte-myofibroblast transition in UUO-induced renal fibrosis.

BACKGROUND: Putative endothelial progenitor cells (pEPCs) have been confirmed to participate in alleviation of renal fibrosis in several ischaemic diseases. However, their mechanistic effect on renal fibrosis, which is characterized by vascular regression and further rarefaction-related pathology, remains unknown. METHODS: To explore the effect and molecular mechanisms by which pEPCs act on unilateral ureteral obstruction (UUO)-induced renal fibrosis, we isolated pEPCs from murine bone marrow. In vivo, pEPCs (2 × 105 cells/day) and pEPC-MVs (microvesicles) were injected into UUO mice via the tail vein. In vitro, pEPCs were co-cultured with renal-derived pericytes. Pericyte-myofibroblast transition was evaluated using the myofibroblast marker α-smooth muscle actin (α-SMA) and pericyte marker platelet-derived growth factor receptor ß (PDGFR-ß). RESULTS: Exogenous supply of bone marrow-derived pEPCs attenuated renal fibrosis by decreasing pericyte-myofibroblast transition without significant vascular repair in the UUO model. Our results indicated that pEPCs regulated pericytes and their transition into myofibroblasts via pEPC-MVs. Co-culture of pericytes with pEPCs in vitro suggested that pEPCs inhibit transforming growth factor-ß (TGF-ß)-induced pericyte-myofibroblast transition via a paracrine pathway. CONCLUSION: pEPCs effectively attenuated UUO-induced renal fibrosis by inhibiting pericyte-myofibroblast transition via a paracrine pathway, without promoting vascular repair.

Evaluation of the safety and tolerability of tamoxifen for ischemia-incited renal injury in mice.

Tamoxifen is used to activate tamoxifen-dependent Cre recombinase (CreER) to generate time- and tissue-specific genetically mutant mice. However, tamoxifen is also an active estrogen analogue that binds with higher affinity to estrogen receptors and exhibits anti-apoptosis, anti-inflammation, and antifibrotic properties. Renal ischemia reperfusion (I/R) injury is characterized by increased apoptosis and inflammation, so optimal utility of tamoxifen-inducible CreER genetic systems in I/R model is important. The purpose of this study was to optimize the tamoxifen dose and evaluate its safety and tolerability in the development of mouse I/R injury. Seven-week-old C57/B6 mice were subjected to moderate reversible unilateral I/R and then injected intraperitoneally daily for 5 days with tamoxifen at doses of 50, 100, or 200 mg/kg/day. Regardless of the time of sacrifice, at 5 day or 28 day after I/R injury, there were no differences in pathological damage, apoptosis, inflammation, or the extent of fibrosis between untreated and treated mice from the time point of acute kidney injury (AKI) to subsequently chronic kidney disease. Data above indicated that tamoxifen with a dose among 0 to 200 mg/kg/day was safe and tolerable for mice, without influencing I/R induced kidney injury in mice. The results suggest that tamoxifen-inducible CreER genetic systems can be safely used in the mouse I/R model.

GAG and collagen II attenuate glucocorticoid-induced osteoporosis by regulating NF-κB and MAPK signaling.

As a component of collagen II, glycosaminoglycan (GAG) has a relatively close relationship with bone metabolism. GAG and collagen II have been proven to promote connection of the bone trabecular structure. However, the exact mechanism remains unknown. In this study, we aimed to determine the concrete effect and the mechanism of GAG and collagen II on glucocorticoid-induced osteoporosis. We implanted prednisolone pellets subcutaneously in mice to mimic glucocorticoid-induced osteoporosis. GAG was administered intragastrically every day for 60 days. The results demonstrated a protective effect of GAG and collagen II on glucocorticoid-induced osteoporosis. Trabecular number and connection density increased after treatment with GAG and collagen II. We generated bone marrow-derived macrophages to explore the effect of GAG and collagen II on osteoclast differentiation. We collected cell protein and RNA in the presence of macrophage colony-stimulating factor (M-CSF) and receptor activator for nuclear factor-κB ligand (RANKL) and found that GAG and collagen II inhibited the NF-κB and MAPK pathways, thereby down-regulating osteoclast differentiation molecules such as matrix metallopeptidase 9 (MMP 9) and nuclear factor of activated T-cells, cytoplasmic 1 (NFATc-1). Our findings suggest that GAG and collagen II may have therapeutic potential of patients with glucocorticoid-induced osteoporosis in clinical settings.

Adipose-derived mesenchymal stem cells employed exosomes to attenuate AKI-CKD transition through tubular epithelial cell dependent Sox9 activation.

Acute kidney injury (AKI) predisposes patients to an increased risk into progressive chronic kidney disease (CKD), however effective treatments are still elusive. This study aimed to investigate the therapeutic efficacy of human adipose-derived MSCs (hAD-MSCs) in the prevention of AKI-CKD transition, and illuminate the role of Sox9, a vital transcription factor in the development of kidney, in this process. C57BL/6 mice were subjected to unilateral renal ischemia/reperfusion (I/R) with or without hAD-MSC treatment. We found that hAD-MSC treatment upregulated the expression of tubular Sox9, promoted tubular regeneration, attenuated AKI, and mitigated subsequent renal fibrosis. However, these beneficial effects were abolished by a drug inhibiting the release of exosomes from hAD-MSCs. Similarly, Sox9 inhibitors reversed these protective effects. Further, we verified that hAD-MSCs activated tubular Sox9 and prevented TGF-ß1-induced transformation of TECs into pro-fibrotic phenotype through exosome shuttling in vitro, but the cells did not inhibit TGF-ß1-induced transition of fibroblasts into myofibroblasts. Inhibiting the release of exosomes from hAD-MSCs or the expression of Sox9 in TECs reversed these antifibrotic effects. In conclusion, hAD-MSCs employed exosomes to mitigate AKI-CKD transition through tubular epithelial cell dependent activation of Sox9.

Melatonin promoted renal regeneration in folic acid-induced acute kidney injury via inhibiting nucleocytoplasmic translocation of HMGB1 in tubular epithelial cells.

Melatonin (N-acetyl-5-methoxytryptamine), a circadian-regulating hormone, has been reported to exert a protective role during acute kidney injury (AKI) induced by renal ischemia-reperfusion injury (I/R). High-mobility group box 1 (HMGB1) is a novel member of the damage-associated molecular pattern (DAMP) family, and has been verified to be an inflammatory cytokine mediating AKI induced by I/R and cisplatin. However, the effect of melatonin on HMGB1, as well as the relationship of these two with folic acid induced AKI are elusive. In this study, we sought to identify the role of melatonin on folic acid induced AKI and its association with HMGB1. Pretreatment with melatonin significantly attenuated folic acid-induced increase in serum creatinine and BUN levels, renal tubular epithelial cell (TEC) apoptosis, and the infiltration of inflammatory cells and secretion of cytokines. Moreover, melatonin pretreatment promoted renal tubular proliferation and improved cell cycle arrest of TECs after folic acid-induced renal damage. This protective role of melatonin was closely related to the inhibition of nucleocytoplasmic translocation of HMGB1 in TECs. These data provide a strong proof that administering melatonin prior to folic acid insult may shed light on a potential treatment for AKI.