Elevated serum uric acid is associated with renal arteriolopathy and predict poor outcome in patients with lupus nephritis.

OBJECTIVES: Increased serum uric acid (SUA) levels are well known to be concomitant of cardiovascular and kidney diseases, and have been proposed to be implicated in the development of arteriolar damage. The aim of the present study was to assess the association between SUA levels, renal damage and its implication for outcome in patients with lupus nephritis (LN). METHODS: This retrospective study included 194 cases with biopsy proven LN at the Affiliated Hospital of Qingdao University between January 2013 and June 2021. We reviewed clinical, laboratory and histologic data of patients and analysed the correlation between SUA levels, renal damage and the primary outcome (death or ESRD). Biopsy-proven arteriolar damage was defined by the presence of arteriolar hyalinosis and/or intimal thickening. RESULTS: Compared to LN patients without hyperuricemia, LN patients with hyperuricaemia presented with higher BP, hyperlipidaemia, lower eGFR, lower haemoglobin, lower serum albumin, worse renal arteriolar damage and proteinuria, and also higher SLEDAI score, activity index and chronicity index (p<0.05). At logistic regression analysis, SUA was independently related to the presence of arteriolar damage. For each 100 µmol/L increase in SUA levels the risk for arteriolar damage raised by 53.8% (hazard ratio [HR] =1.538; 95% CI: 1.147-2.063; p=0.004) after adjustment for haemoglobin, serum creatinine and erythrocyte sedimentation rate. Cox regression analysis showed that female (HR=3.180; 95% CI: 1.216-8.313; p=0.018), white blood cell count (HR=1.111; 95% CI: 1.027-1.202; p=0.009), SUA (HR=1.100; 95% CI: 1.023-1.253; p=0.035), serum creatinine (HR=1.800; 95% CI: 1.348-2.404; p<0.001), and renal arteriolar damage (HR=3.117; 95% CI: 1.022-9.511; p=0.046) was significantly associated with development of ESRD or death in patients with LN after adjustment for several potential confounding factors. Furthermore, for each 100 µmol/L increase in SUA levels, the risk of ESRD or death increased by 10%. CONCLUSIONS: SUA levels are directly associated with renal arteriolar damage and poor prognosis in LN patients. Hyperuricaemia is an important predictor for poor prognosis in patients with LN.

Mesenchymal stem cells protect against sepsis-associated acute kidney injury by inducing Gal-9/Tim-3 to remodel immune homeostasis.

OBJECTIVE: The present study investigated the specific mechanism by which mesenchymal stem cells (MSCs) protect against sepsis-associated acute kidney injury (SA-AKI). METHODS: Male C57BL/6 mice underwent cecal ligation and puncture surgery to induce sepsis and then received either normal IgG or MSCs (1 × 106 cells, intravenously) plus Gal-9 or soluble Tim-3 3 h after surgery. RESULTS: After cecal ligation and puncture surgery, the mice injected with Gal-9 or MSCs plus Gal-9 had a higher survival rate than the mice in the IgG treatment group. Treatment with MSCs plus Gal-9 decreased serum creatinine and blood urea nitrogen levels, improved tubular function recovery, reduced IL-17 and RORγt levels and induced IL-10 and FOXP3 expression. Additionally, the Th17/Treg cell balance was altered. However, when soluble Tim-3 was used to block the Gal-9/Tim-3 pathway, the septic mice developed kidney injury and exhibited increased mortality. Treatment with MSCs plus soluble Tim-3 blunted the therapeutic effect of MSCs, inhibited the induction of Tregs, and suppressed the inhibition of differentiation into Th17 cells. CONCLUSION: Treatment with MSCs significantly reversed the Th1/Th2 balance. Thus, the Gal-9/Tim-3 pathway may be an important mechanism of MSC-mediated protection against SA-AKI.

Associations between early thiamine administration and clinical outcomes in critically ill patients with acute kidney injury.

The effects of early thiamine use on clinical outcomes in critically ill patients with acute kidney injury (AKI) are unclear. The purpose of this study was to investigate the associations between early thiamine administration and clinical outcomes in critically ill patients with AKI. The data of critically ill patients with AKI within 48 h after ICU admission were extracted from the Medical Information Mart for Intensive Care III (MIMIC III) database. PSM was used to match patients early receiving thiamine treatment to those not early receiving thiamine treatment. The association between early thiamine use and in-hospital mortality due to AKI was determined using a logistic regression model. A total of 15 066 AKI patients were eligible for study inclusion. After propensity score matching (PSM), 734 pairs of patients who did and did not receive thiamine treatment in the early stage were established. Early thiamine use was associated with lower in-hospital mortality (OR 0·65; 95 % CI 0·49, 0·87; P < 0·001) and 90-d mortality (OR 0·58; 95 % CI 0·45, 0·74; P < 0·001), and it was also associated with the recovery of renal function (OR 1·26; 95 % CI 1·17, 1·36; P < 0·001). In the subgroup analysis, early thiamine administration was associated with lower in-hospital mortality in patients with stages 1 to 2 AKI. Early thiamine use was associated with improved short-term survival in critically ill patients with AKI. It was possible beneficial role in patients with stages 1 to 2 AKI according to the Kidney Disease: Improving Global Outcomes criteria.

Scutellarin protects the kidney from ischemia/reperfusion injury by targeting Nrf2.

BACKGROUND: Acute kidney injury (AKI) results in high morbidity and mortality among inpatients, while effective treatment and intervention are still absent. Therefore, this study aims to explore the effects of Scutellarin (Scu) in experimental models in vivo and in vitro. METHODS: In vivo experiment, we employed a total of 30 Wistar rats, which further were modelled by a bilateral renal pedicle clip for 45 min, then received 50 mg/kg/day Scu. In vitro, HK-2 cells were administered with 20µΜ Scu and then incubated in hypoxia/reoxygenation (H/R) conditions for 24 h. The knockdown of Nrf2 expression was conducted by small interfering RNA (siRNA) transfection. RESULTS: As a result, the AKI model was well established with an increased SCr, BUN, KIM-1 level, and histological injury score, while Scu treatment reduced the levels above and increased the antioxidative enzyme HO-1. H/R induced an increase of ROS in HK-2 cells, while Scu decreased the ROS level. Bioinformatics results showed the transcription factor Nrf2 was a hub protein during the AKI, which also bound to Scu with low binding energy, indicating that the downstream effect of Scu might be mediated by Nrf2. To verify the suppose above, we employed siRNA against Nrf2, which shows a significant increase in ROS after Nrf2 was blocked. Meanwhile, the HO-1 showed similar expression compared with the 'H/R + Nrf2 siRNA' and 'H/R + Nrf2 siRNA + Scu' group, implying the protective effect of Scu was mediated by the Nrf2/HO-1 pathway. CONCLUSION: Scu led to up-regulation of HO-1 through activating the Nrf2 signalling pathway, protecting the kidneys from ischemia/reperfusion (I/R)-induced oxidative damage.

Curcumin modulates gut microbiota and improves renal function in rats with uric acid nephropathy.

It is well known that the progression of hyperuricemia disease often contributes to renal dysfunction. However, there have been few studies on uric acid nephropathy (UAN), especially its relationship with gut microbiota. UAN is usually accompanied by disordered intestinal flora, and damaged gut barrier, which are closely related to tubulointerstitial fibrosis, and systemic inflammation. In previous studies, it has been confirmed that curcumin could alleviate tubulointerstitial fibrosis, and improve renal function through its antioxidant, anti-apoptotic, and anti-inflammatory efficacies. However, the effects curcumin exerts on intestinal flora in uric acid nephropathy are still unknown. Therefore, we used next-generation sequencing technology to investigate the effects of curcumin on gut microbiota in a rat model of UAN induced by adenine and potassium oxonate, and rats were randomly divided into control, model or curcumin treatment groups. The results demonstrated that, compared to the model group, the treatment group showed decreased serum uric acid (156.80 ± 11.90 µmol/L vs. 325.60 ± 18.65 µmol/L, p < 0.001), serum creatinine (66.20 ± 11.88 µmol/L vs. 182.20 ± 8.87 µmol/L, p < 0.001) and BUN level (13.33 ± 3.16 mmol/L vs. 36.04 ± 6.60 mmol/L, p < 0.001). The treatment group also displayed attenuated renal pathological lesions and metabolic endotoxemia (25.60 ± 5.90 ng/mL vs. 38.40 ± 4.98 ng/mL, p < 0.01), and improved tightly linked proteins expression. Besides, curcumin altered the gut microbiota structure in UAN rats. More specifically, curcumin treatment protected against the overgrowth of opportunistic pathogens in UAN, including Escherichia-Shigella and Bacteroides, and increased the relative abundance of bacteria producing short-chain fatty acids (SCFAs), such as Lactobacillus and Ruminococcaceae. These results suggest that curcumin could modulate gut microbiota, fortify the intestinal barrier, attenuate metabolic endotoxemia, and consequently protect the renal function in UAN rats.

Malnutrition screening and acute kidney injury in hospitalised patients: a retrospective study over a 5-year period from China.

Malnutrition and acute kidney injury (AKI) are common complications in hospitalised patients, and both increase mortality; however, the relationship between them is unknown. This is a retrospective propensity score matching study enrolling 46 549 inpatients, aimed to investigate the association between Nutritional Risk Screening 2002 (NRS-2002) and AKI and to assess the ability of NRS-2002 and AKI in predicting prognosis. In total, 37 190 (80 %) and 9359 (20 %) patients had NRS-2002 scores <3 and ≥3, respectively. Patients with NRS-2002 scores ≥3 had longer lengths of stay (12·6 (sd 7·8) v. 10·4 (sd 6·2) d, P < 0·05), higher mortality rates (9·6 v. 2·5 %, P < 0·05) and higher incidence of AKI (28 v. 16 %, P < 0·05) than patients with normal nutritional status. The NRS-2002 showed a strong association with AKI, that is, the risk of AKI changed in parallel with the score of the NRS-2002. In short- and long-term survival, patients with a lower NRS-2002 score or who did not have AKI achieved a significantly lower risk of mortality than those with a high NRS-2002 score or AKI. Univariate Cox regression analyses indicated that both the NRS-2002 and AKI were strongly related to long-term survival (AUC 0·79 and 0·71) and that the combination of the two showed better accuracy (AUC 0·80) than the individual variables. In conclusion, malnutrition can increase the risk of AKI and both AKI and malnutrition can worsen the prognosis that the undernourished patients who develop AKI yield far worse prognosis than patients with normal nutritional status.

Acute kidney injury after nephrectomy: a new nomogram to predict postoperative renal function.

BACKGROUND: We aimed to develop a nomogram based on preprocedural features for early prediction of acute kidney injury (AKI) and to assess the prognosis in patients after radical and partial nephrectomy. METHODS: The study included a development cohort of 1111 patients who were treated between June 2012 and June 2017 and an additional validation cohort of 356 patients who were treated between July 2017 and June 2018. Stepwise regression and logistic regression analyses were used to evaluate the association between predictors and AKI. Incorporating all independent predictors, a nomogram for postoperative AKI was developed and externally validated. Patients were followed up for 5 years to assess renal function, acute kidney disease (AKD), chronic kidney disease (CKD), hospital readmission and mortality were key prognosis we focused on. RESULTS: After multivariate logistic regression, radical nephrectomy (odds ratio (OR) = 3.57, p < 0.001), aspirin (OR = 1.79, p = 0.008), systolic blood pressure (OR = 1.41, p = 0.004), triglyceride (OR = 1.26, p = 0.024), and alkaline phosphatase (OR = 1.75, p = 0.034) were independent risk factors for postoperative AKI, while albumin (OR = 0.72, p = 0.031) was a protective factor for postoperative AKI. Patients with a higher estimated glomerular filtration rate (eGFR) (60-90 ml/min/1.73 m2, OR = 0.41, p = 0.004; ≥ 90 ml/min/1.73 m2, OR = 0.37, p < 0.001) were less prone to AKI than those with a lower eGFR (< 15 ml/min/1.73 m2). These predictors were all included in the final nomogram. The area under the receiver operating characteristics curve for the model were 0.77 (p < 0.001) in the development cohort and 0.72 (p < 0.001) in the validation cohort. The incidence of AKD and CKD were 27.12 and 18.64% in AKI group, which were much higher than those in no AKI group (p < 0.001). CONCLUSIONS: The nomogram had excellent predictive ability and might have significant clinical implications for the early detection of AKI in patients undergoing nephrectomy.

A visual risk assessment tool for acute kidney injury after intracranial aneurysm clipping surgery.

OBJECTIVE: The aim of the study was to establish a predictive postoperative nomogram for acute kidney injury (AKI) after intracranial aneurysm clipping surgery, in order to early identify patients with high postoperative AKI risk. METHODS: This is a retrospective study, which included patients who underwent intracranial aneurysm clipping surgery. Multivariate logistic regression was employed to select confound factors that associated with AKI, then incorporated into the nomogram. The predictive accuracy of the model was assessed by concordance index (C-Index). RESULTS: A total of 365 patients after intracranial aneurysm clipping surgery were enrolled in the study eventually, of which 68 (18.63%) suffered postoperative AKI, and the incidence of stage 1, stage 2 and stage 3 were 92.65% (63/68), 5.88% (4/68), and 1.47% (1/68), respectively. Univariate logistic regression revealed that high density lipoprotein (HDL), prothrombin time (PT), estimated glomerular filtration rate (eGFR), size of aneurysm ≥10 mm, and aneurysm ruptured before surgery were associated with AKI after surgery, while multivariate logistic regression showed same results as the size of aneurysm ≥10 mm and aneurysm ruptured were independent AKI risk factors. In addition, the nomogram demonstrated a good accuracy in estimating intracranial aneurysm clipping associated AKI, as a C-Index and a bootstrap-corrected one of 0.772 and 0.737, respectively. Moreover, calibration plots showed consistency with the actual presence of AKI. CONCLUSION: The novel nomogram model can serve as a promising predictive tool to improve the identification of AKI among those who underwent intracranial aneurysm clipping surgery.

The Mechanisms Involved in Mesenchymal Stem Cell Alleviation of Sepsis-Induced Acute Lung Injury in Mice: A Pilot Study.

BACKGROUND: Acute lung injury is a common complication of sepsis in intensive care unit patients. Inflammation is among the main mechanisms of sepsis. Therefore, suppression of inflammation is an important mechanism for sepsis treatment. Mesenchymal stem cells (MSCs) have been reported to exhibit antimicrobial properties. OBJECTIVE: The present study investigated the effects of MSCs on sepsis-induced acute lung injury. METHODS: Male C57BL/6 mice underwent a cecal ligation and puncture (CLP) operation to induce sepsis and then received either normal saline or MSCs (1 × 106 cells intravenously) at 3 hours after surgery. Survival after surgery was assessed. Lung injury was assessed by histology score, the presence of lung edema, vascular permeability, inflammatory cell infiltration, and cytokine levels in bronchoalveolar lavage fluid. Finally, we tested nuclear factor kappa-light-chain-enhancer of activated B cells activation in lung tissue. RESULTS: As expected, CLP caused lung injury as indicated by significant increases in the histopathology score, lung wet to dry weight ratio, and total protein concentration. However, mice treated with MSCs had amelioration of the lung histopathologic changes, lung wet to dry weight ratio, and total protein concentration. The levels of cytokines tumor necrosis factor alpha, interleukin 6, interleukin 1ß, and interleukin 17 in bronchoalveolar lavage fluid were dramatically decreased after MSCs treatment. In contrast, expression of interleukin 10 was increased after MSCs treatment. Moreover, mice treated with MSCs had a higher survival rate than the CLP group. Neutrophil infiltration into bronchoalveolar lavage fluid was attenuated after MSCs injection, but the amounts of macrophages observed in the MSC group showed no significant differences compared with the CLP group. In addition, MSCs treatment significantly reduced nuclear factor kappa-light-chain-enhancer of activated B cells activation in lung tissue. CONCLUSIONS: Based on the above findings, treatment with MSCs dampened the inflammatory response and inhibited nuclear factor kappa-light-chain-enhancer of activated B cells activation in the mouse CLP model. Thus, MSCs may be a potential new agent for the treatment of sepsis-induced acute lung injury. (Curr Ther Res Clin Exp. 2020; 81:XXX-XXX).

MiR-183 delivery attenuates murine lupus nephritis-related injuries via targeting mTOR.

MicroRNAs (miRNAs) play a vital role in the occurrence and development of many human diseases, including systemic lupus erythematosus (SLE). SLE is an autoimmune disease characterized by the production of autoantibodies against nuclear antigens and multiorgan involvement. Study of miRNAs involved in SLE provides new insights into the pathogenesis of SLE and might lead to the identification of new therapeutic interventions. The aim of this study was to investigate the effect of miR-183 injection on the progression of SLE by using MRL/lpr mouse model. The expression levels of miR-183 and mTOR mRNA were detected by quantitative real-time PCR assay. The effect of miR-183 on the course of spontaneous disease progression in the MRL/lpr mice was examined by intraperitoneal injection of miR-183 into mice and followed by monitoring lifespan, anti-dsDNA antibody levels, urinary albumin levels, blood urea nitrogen (BUN) levels, and Tregs and Th17 cell population. We found that miR-183 injection resulted in reduction of anti-DNA antibody and immune complex component levels, restoration of Tregs and Th17 cell population and prolongation of survival. Our findings suggest that miR-183 injection may serve as an effective therapeutic treatment for delaying or easing pathologic features of SLE.

The urate-lowering efficacy and safety of febuxostat versus allopurinol in Chinese patients with asymptomatic hyperuricemia and with chronic kidney disease stages 3-5.

BACKGROUND: While the dose of allopurinol is limited in patients with chronic kidney disease (CKD), information is lacking concerning the efficacy, safety, and maintenance dose of febuxostat in Chinese patients with hyperuricemia and with CKD stages 3-5. METHODS: A single center, prospective cohort study was conducted in patients with CKD stages 3-5 and with hyperuricemia who had not yet begun to undergo renal replacement therapy. We enrolled 208 patients who were newly treated with febuxostat (n = 112) or allopurinol (n = 96) in this study. The efficacy of febuxostat was determined by the proportion of patients with serum uric acid (sUA) < 360 µmol/L at the end of the study and changes of renal function. RESULTS: The target of sUA < 360 µmol/L was reached by 96.4% of participants in the febuxostat group and 37.5% in the allopurinol group at 6 months. The eGFR in the febuxostat group showed an increase from 28.45 to 30.65 mL/min/1.73 m2 at 6 months, while in the allopurinol group, the eGFR decreased from 28.06 to 24.39 mL/min/1.73 m2. Linear regression analysis showed that the reduction in sUA was significantly associated with an increase in eGFR and decrease in proteinuria. We found that 83.0% of the patients could remain with sUA < 360 µmol/L at a maintenance dose of febuxostat 20 mg/day. CONCLUSION: Febuxostat had superior urate-lowering efficacy to that of allopurinol in Chinese Han patients with hyperuricemia with CKD stages 3-5, and the reduction in sUA levels was associated with a slower progression of renal function.

Cysteine-rich protein 61, a specific ultra-early biomarker in kidney ischemia/reperfusion injury.

AIM: Studies have shown that cysteine-rich protein 61 (Cyr61) increased in the post-ischemic human kidney tissue. However, it is still unknown whether Cyr61 can be used as a biomarker in kidney ischemia/reperfusion (I/R) injury. METHODS: Microarray data were collected from GSE58438 and GSE52004. The rat I/R model was established to evaluate the messenger RNA and protein expression of Cyr61, localization of Cyr61 by immunohistochemical and immunofluorescence staining, and changes in serum creatinine (Scr) at the same time. RESULTS: Bioinformatics result showed that Cyr61 was significantly increased at 3 h after I/R in rat kidney, and involved in angiogene, positive regulation of locomotion and single organism cell adhesion. The rat I/R model results showed that Cyr61 was mainly expressed in renal tubular epithelial cells with I/R injury and the expression of Cyr61 was up-regulated at I/R 1 h, peaked at 4-8 h and began to decay at 12 h. The area under curve of receiver operating characteristics of kidney tissue Cyr61 messenger RNA and urine Cyr61 were 90.2% and 86.1%, which all better than Scr 67.1% (P < 0.05). CONCLUSION: We made a preliminary investigation of the relationship between Cyr61 and AKI, which identifies that Cyr61 may replace Scr as an ultra-early new biomarker in AKI.

Downregulation of long non-coding RNA MEG3 promotes proliferation, migration, and invasion of human hepatocellular carcinoma cells by upregulating TGF-ß1.

Hepatocellular carcinoma is a common malignant cancer with high incidence. And long non-coding RNAs (lncRNAs) play pivotal roles in the development of different types of cancers. In this study, we aimed to investigate the role of lncRNA maternally expressed gene 3 (MEG3) in the development and progression of hepatocellular carcinoma. Expression of MEG3 in tumor tissues and adjacent healthy tissues of hepatocellular carcinoma patients, as well as the serum of both hepatocellular carcinoma patients and healthy controls, was detected by quantitative reverse transcriptase-polymerase chain reaction. The results showed that expression level of MEG3 was significantly lower in tumor tissues than in adjacent healthy tissues. Serum level of MEG3 was also significantly lower in hepatocellular carcinoma patients than in normal controls. The receiver operating characteristic curve analysis was used to evaluate the diagnostic value of MEG3 for hepatocellular carcinoma, and the prognostic value of MEG3 for this disease was analyzed using Kaplan-Meier method. The results indicated that serum level of MEG3 was a diagnostic and prognostic marker for hepatocellular carcinoma. We also found that MEG3 small interfering Ribonucleic Acid (siRNA) silencing promoted the proliferation, migration, and invasion of hepatocellular carcinoma cells by CCK-8 assay, transwell migration, and invasion assay, respectively, while TGF-ß inhibitor treatment reduced those enhancing effects. MEG3 siRNA silencing also increased the expression level of TGF-ß1. These results indicated that downregulation of MEG3 can promote proliferation, migration, and invasion of human hepatocellular carcinoma cells by upregulating TGF-ß1 expression.

Effects of uric acid-lowering therapy on the progression of chronic kidney disease: a systematic review and meta-analysis.

OBJECTIVES: Whether uric acid levels were associated with the progression of chronic kidney disease (CKD) remained controversial. This meta-analysis was aimed to assess the effect of lowering serum uric acid therapy on the progression of CKD to clarify the role of uric acid in the progression of CKD indirectly. METHODS: Pubmed, Embase, the Cochrane library, CBM were searched for randomized controlled trials (RCTs) that assessed the efficiency of lowering serum uric acid therapy on the progression of CKD without language restriction. Summary estimates of weighted mean differences (WMDs) and relative risk (RR) were obtained by using random-effect or fixed-effect models. Sensitivity analyses were performed to identify the source of heterogeneity. RESULTS: A total of 12 randomized controlled trials with 832 CKD participants were included in the analysis. Pooled estimate for eGFR was in favor of lowering serum uric acid therapy with a mean difference (MD) of 3.88 ml/min/1.73 m2, 95% CI 1.26-6.49 ml/min/1.73 m2, p = .004 and this was consistent with results for serum creatinine. The risk of worsening of kidney function or ESRD or death was significantly decreased in the treatment group compared to the control group (RR 0.39, 95% CI 0.28-0.52, p< .01). CONCLUSIONS: Uric acid-lowering therapy may be effective in retarding the progression of CKD. Further randomized controlled trials should be performed to confirm the effect of lowering serum uric acid therapy on the progression of CKD.

Outcomes and complications of hemodialysis in patients with renal cancer following bilateral nephrectomy.

Objectives: The management of patients undergoing bilateral nephrectomy for renal cancer presents significant challenges, particularly in addressing hypotension, anemia, and tumor recurrence during hemodialysis. Case presentation: A patient diagnosed with renal clear cell carcinoma in 2009 was followed until his demise in June 2022, with detailed documentation of symptoms, signs, laboratory results, diagnosis, and treatment. In the presented case, post-nephrectomy, the patient experienced frequent hypotension and anemia during dialysis, improving with erythropoietin-stimulating agents and subsequently with rosuvastatin. Later, multiple metastases were detected, correlating with normalized blood pressure and hemoglobin. Literature review: A literature search up to September 2023 was also conducted, gathering data on hypotension, anemia, and tumor recurrence post-nephrectomy. Literature analysis of six cases revealed a 100% tumor recurrence rate in elderly patients (>50 years). Conclusion: Treatment of anemia in bilateral nephrectomy patients warrants consideration of medication-induced tumor recurrence, highlighting early kidney transplantation to avoid adverse reactions like hypotension.

Mesenchymal Stem Cells Attenuate Sepsis-associated Acute Kidney Injury by Changing the Balance of Th17 cells/Tregs via Gal-9/Tim-3.

OBJECTIVE: The aim of the present study was to investigate the protective effect of MSCs on CLP-induced SA-AKI and determine the mechanisms of this effect. METHODS: The expression of Gal-9 and Tim-3 was assayed by qPCR and western blot. IL-10, IL-17, RORγt, and FOXP3 were assayed by qPCR and TNFα, INFγ, IL-4, and IL-6 were assayed by ELISA in renal samples after CLP with or without MSCs treatment. The expression of Gal-9 in MSCs was knocked down in vivo using RNA interference, and si-Gal-9-MSCs were injected in SA-AKI mice. The effect of MSCs on the differentiation of lymphocytes into Th17 cells and Tregs was evaluated in vitro by FAC in coculture of MSCs and CD4+ T cells and after blockade of the Gal-9/Tim-3 pathway. RESULTS: MSCs decreased serum creatinine and urea nitrogen levels and relieved tubular injury. Additionally, MSCs significantly improved the survival rate and markedly attenuated the infiltration of neutrophils and the levels of TNF-α, IFN-γ, IL-4, and IL-6 in the kidneys of septic mice (P < 0.05). Treatment with MSCs also reduced the proportion of Th17 cells and the levels of IL-17 and RORγt (P < 0.05). In contrast, MSCs increased the proportion of Tregs and the levels of IL-10 and FOXP3 related to these cells (P < 0.05). Furthermore, we determined whether Gal-9/Tim-3 and Th17 cells/Tregs are involved in the protective effects of MSCs in an SA-AKI model. The results of Western blot and real-time PCR indicated that MSCs inhibited the expression of Tim-3 and increased the expression of gal-9 (P < 0.05). Knockdown of gal-9 in MSCs using small interfering RNA blunted the therapeutic effect of MSCs, and blockade of the Gal-9/Tim-3 pathway using α-lactose or anti-Tim-3 inhibited the induction of Tregs and suppressed the inhibition of the differentiation to Th17 cells by MSCs after coculture of MSCs with CD4+ T cells (P > 0.05). CONCLUSION: Treatment with MSCs can protect against SA-AKI. The results suggested that the relieving effect of MSCs against SA-AKI may be partially mediated by the induction of Tregs and inhibition of Th17 cells via the Gal-9/Tim-3 pathway.

Hexarelin alleviates apoptosis on ischemic acute kidney injury via MDM2/p53 pathway.

INTRODUCTION: Hexarelin exhibits significant protection against organ injury in models of ischemia/reperfusion (I/R)-induced injury (IRI). Nevertheless, the impact of Hexarelin on acute kidney injury (AKI) and its underlying mechanism remains unclear. In this study, we investigated the therapeutic potential of Hexarelin in I/R-induced AKI and elucidated its molecular mechanisms. METHODS: We assessed the protective effects of Hexarelin through both in vivo and in vitro experiments. In the I/R-induced AKI model, rats were pretreated with Hexarelin at 100 µg/kg/d for 7 days before being sacrificed 24 h post-IRI. Subsequently, kidney function, histology, and apoptosis were assessed. In vitro, hypoxia/reoxygenation (H/R)-induced HK-2 cell model was used to investigate the impact of Hexarelin on apoptosis in HK-2 cells. Then, we employed molecular docking using a pharmmapper server and autodock software to identify potential target proteins of Hexarelin. RESULTS: In this study, rats subjected to I/R developed severe kidney injury characterized by tubular necrosis, tubular dilatation, increased serum creatinine levels, and cell apoptosis. However, pretreatment with Hexarelin exhibited a protective effect by mitigating post-ischemic kidney pathological changes, improving renal function, and inhibiting apoptosis. This was achieved through the downregulation of conventional apoptosis-related genes, such as Caspase-3, Bax and Bad, and the upregulation of the anti-apoptotic protein Bcl-2. Consistent with the in vivo results, Hexarelin also reduced cell apoptosis in post-H/R HK-2 cells. Furthermore, our analysis using GSEA confirmed the essential role of the apoptosis pathway in I/R-induced AKI. Molecular docking revealed a strong binding affinity between Hexarelin and MDM2, suggesting the potential mechanism of Hexarelin's anti-apoptosis effect at least partially through its interaction with MDM2, a well-known negative regulator of apoptosis-related protein that of p53. To validate these findings, we evaluated the relative expression of MDM2 and p53 in I/R-induced AKI with or without Hexarelin pre-administration and observed a significant suppression of MDM2 and p53 by Hexarelin in both in vivo and in vitro experiments. CONCLUSION: Collectively, Hexarelin was identified as a promising medication in protecting apoptosis against I/R-induced AKI.

[Scutellarin alleviates lipopolysaccharide-induced renal injury via mediating cysteine-rich protein 61-connective tissue growth factor-nephroblastoma overexpressed gene 1 expression to inhibit nuclear factor-κB signaling pathway].

OBJECTIVE: To explore the protective effect and mechanism of scutellarin (Scu) on sepsis associated-acute kidney injury (SA-AKI). METHODS: (1) In vivo experiment: 36 male C57BL/6 mice were divided into normal saline (NS) control group, lipopolysaccharide (LPS) induced SA-AKI model group (LPS group), 20 mg/kg Scu control group (Scu 20 control group), and 5, 10, 20 mg/kg Scu pretreatment groups by random number table with 6 mice in each group. The SA-AKI model was reproduced by intraperitoneal injection of 10 mg/kg LPS. The NS control group was injected with NS intraperitoneally. The Scu pretreatment groups were intraperitoneally injected with different doses of Scu every day before LPS injection for 1 week. Scu 20 control group was injected with 20 mg/kg Scu for 1 week. After 24 hours of LPS treatment, mice in each group were sacrificed, kidney tissues were collected, and kidney injury was detected by hematoxylin-eosin (HE) staining. Western blotting was used to detect the protein expression levels of nuclear factor-κB (NF-κB) signaling pathway related molecules, apoptosis-related proteins and cysteine-rich protein 61-connective tissue growth factor-nephroblastoma overexpressed gene 1 (CCN1). (2) In vitro experiment: human renal tubular epithelial cell line HK-2 was cultured in vitro and used for experiment when the cells fused to 80%. In the cells without LPS treatment and after 100 g/L LPS treatment, pcDNA3.1-CCN1 and small interfering RNA (siRNA) CCN1 sequence were transfected to overexpress and inhibit CCN1 expression, respectively, to observe whether CCN1 was involved in NF-κB signaling pathway activation and apoptosis. In addition, 100g/L LPS and 20 µmol/L Scu were added into HK-2 cells transfected with and without CCN1 siRNA to investigate the mechanism of protective effect of Scu on LPS-induced HK-2 cells injury. RESULTS: (1) The results of in vivo experiment: the renal function of SA-AKI mice induced by LPS was significantly decreased, and had kidney histological damage and severely damaged renal tubules. Scu could alleviate renal function and histological damage in a dose-dependent manner. Western blotting results showed Scu could reduce the protein expression of NF-κB signaling pathway related molecules and CCN1 in the renal tissue, and had a significant alleviating effect on apoptosis, indicating that CCN1 was involved in NF-κB signaling pathway activation and apoptosis. (2) The results of in vitro experiment: in HK-2 cells not treated with LPS, CCN1 overexpression had no effect on apoptosis related protein and pro-inflammatory factors of NF-κB signaling pathway. In HK-2 cells treated with LPS, overexpression of CCN1 significantly inhibited the mRNA expressions of interleukin-1ß (IL-1ß), tumor necrosis factor-α (TNF-α) and monocyte chemoattractant protein-1 (MCP-1), with significant differences as compared with cells stimulated only by LPS [IL-1ß mRNA (2-ΔΔCT): 3.20±0.57 vs. 4.88±0.69, TNF-α mRNA (2-ΔΔCT): 2.99±0.44 vs. 5.00±0.81, MCP-1 mRNA (2-ΔΔCT): 2.81±0.50 vs. 5.41±0.75, all P < 0.05], and the apoptosis-related protein was significantly down-regulated. However, when siRNA was used to inhibit the expression of CCN1, the mRNA expressions of pro-inflammatory factors were significantly increased as compared with cells stimulated only by LPS [IL-1ß mRNA (2-ΔΔCT): 6.01±1.13 vs. 4.88±0.69, TNF-α mRNA (2-ΔΔCT): 5.15±0.86 vs. 5.00±0.81, all P < 0.05], and apoptosis-related protein was significantly up-regulated. In the LPS-induced HK-2 cells, the mRNA expressions of pro-inflammatory factors were significantly down-regulated after Scu treatment as compared with cells stimulated only by LPS [IL-1ß mRNA(2-ΔΔCT): 2.55±0.50 vs. 6.15±1.04, TNF-α mRNA (2-ΔΔCT): 2.58±0.40 vs. 3.95±0.52, MCP-1 mRNA (2-ΔΔCT): 2.64±0.44 vs. 6.21±0.96, all P < 0.05], and apoptosis-related protein was also significantly reduced. When the expression of CCN1 was inhibited by siRNA, the protective effect of Scu on cells was weakened, which showed that the mRNA expressions of pro-inflammatory factors in cells was significantly up-regulated compared with the cells without inhibition of CCN1 expression [IL-1ß mRNA (2-ΔΔCT): 5.34±0.76 vs. 2.55±0.50, TNF-α mRNA (2-ΔΔCT): 3.66±0.54 vs. 2.58±0.40, MCP-1 mRNA (2-ΔΔCT): 5.15±0.79 vs. 2.64±0.44, all P < 0.05], and the expression of apoptosis related protein was also significantly up-regulated. CONCLUSIONS: Scu could protect the renal function in SA-AKI mice, and the protective effect is associated with NF-κB signaling pathway and CCN1. Thus, Scu could alleviate LPS-induced kidney injury by regulating the NF-κB signaling pathway.

Serum response factor, a novel early diagnostic biomarker of acute kidney injury.

OBJECTIVE: Studies have shown that serum response factor (SRF) is increased in chronic kidney injury, such as diabetic nephropathy, hyperuricemic nephropathy and renal cell carcinoma. The objective is to explore the early diagnostic value of SRF in acute kidney injury (AKI). METHODS: AKI-related microarray data were analyzed, and the expression and location of SRF were investigated in the early phase of AKI. RESULTS: Bioinformatics results demonstrated that SRF was dramatically elevated 2-4 h after ischemia/reperfusion (I/R) in mouse renal tissue. In I/R rats, SRF was mostly expressed and located in renal tubular epithelial cells (TECs). SRF started to increase at 1 h, peaked at 3-9 h and started to decrease at 12 h after I/R. The areas under the ROC curve of renal SRF mRNA, renal SRF protein, urinary SRF, serum SRF and serum creatinine (Scr) were 87.9%, 83.0%, 81.3%, 78.8%, 68.8%, respectively. CONCLUSION: SRF is remarkably upregulated in early (before 24 h) AKI and can replace Scr as a potential new early diagnostic biomarker of AKI.

Protective effects of resveratrol on acute kidney injury in rats with sepsis.

AIM: To evaluate the protective effects of resveratrol on acute kidney injury (AKI) in septic rats. METHODS: A septic rat model was established by cecal ligation and puncture (CLP). A total of 108 male Sprague Dawley rats were randomly divided into an observation group, a 6 h resveratrol intervention group and a 12 h resveratrol intervention group. Then each group was subdivided into Sham, Sham + Res, CLP and CLP + Res groups. After surgery, the survival and morphological changes in kidney tissues were observed. Serum creatinine and urea nitrogen levels, expression of GRP78, BiP, IRE1 and p65 in kidney tissues, and serum levels of TNF-α, IL-1ß, IL-6 and IL-10 were investigated. RESULTS: The survival rate of CLP + Res group (75.00%) significantly exceeded that of the CLP group (41.67%) (P<0.05). At postoperative 12 h, resveratrol significantly decreased serum creatinine and urea nitrogen levels (P<0.05). Resveratrol evidently relieved renal tubular swelling and luminal narrowing in CLP rats, and significantly reduced the high expressions of GRP78, BiP, phosphorylated IRE1 and p65 proteins (P<0.05). P65 was mainly located in the cytoplasm of Sham, Sham + Res and CLP + Res groups, and in the nucleus of the CLP group. At postoperative 12 h, resveratrol significantly reduced serum levels TNF-α, IL-1ß and IL-6 in CLP rats (P<0.05), whereas elevated that of IL-10 (P<0.05). CONCLUSION: Resveratrol significantly decreased the mortality rate of septic rats and alleviated AKI, probably by attenuating endoplasmic reticulum stress, inhibiting activation of the NF-κB pathway and mitigating the inflammatory response.