Peroxiredoxin 1 aggravates acute kidney injury by promoting inflammation through Mincle/Syk/NF-κB signaling.

Damage-associated molecular patterns (DAMPs) are a cause of acute kidney injury (AKI). Our knowledge of these DAMPs remains incomplete. Here, we report serum peroxiredoxin 1 (Prdx1) as a novel DAMP for AKI. Lipopolysaccharide (LPS) and kidney ischemia/reperfusion injury instigated AKI with concurrent increases in serum Prdx1 and reductions of Prdx1 expression in kidney tubular epithelial cells. Genetic knockout of Prdx1 or use of a Prdx1-neutralizing antibody protected mice from AKI and this protection was impaired by introduction of recombinant Prdx1 (rPrdx1). Mechanistically, lipopolysaccharide increased serum and kidney proinflammatory cytokines, macrophage infiltration, and the content of M1 macrophages. All these events were suppressed in Prdx1-/- mice and renewed upon introduction of rPrdx1. In primary peritoneal macrophages, rPrdx1 induced M1 polarization, activated macrophage-inducible C-type lectin (Mincle) signaling, and enhanced proinflammatory cytokine production. Prdx1 interacted with Mincle to initiate acute kidney inflammation. Of note, rPrdx1 upregulated Mincle and the spleen tyrosine kinase Syk system in the primary peritoneal macrophages, while knockdown of Mincle abolished the increase in activated Syk. Additionally, rPrdx1 treatment enhanced the downstream events of Syk, including transcription factor NF-κB signaling pathways. Furthermore, serum Prdx1 was found to be increased in patients with AKI; the increase of which was associated with kidney function decline and inflammatory biomarkers in patient serum. Thus, kidney-derived serum Prdx1 contributes to AKI at least in part by activating Mincle signaling and downstream pathways.

[Status Quo and Research Progress in Diagnosis and Treatment of Patients With Diabetes Mellitus and Chronic Kidney Disease].

As the incidence of diabetes mellitus is rapidly increasing worldwide,that of related complications,such as diabetic kidney disease(DKD),also increases,conferring a heavy economic burden on the patients,families,society,and government.Diabetes mellitus complicated with chronic kidney disease(CKD)includes DKD and the CKD caused by other reasons.Because of the insufficient knowledge about CKD,the assessment of diabetes mellitus complicated with CKD remains to be improved.The therapies for diabetes mellitus complicated with CKD focus on reducing the risk factors.In clinical practice,DKD may not be the CKD caused by diabetes.According to clinical criteria,some non-diabetic kidney disease may be misdiagnosed as DKD and not be treated accurately.This review summarizes the status quo and research progress in the assessment,diagnosis,and treatment of diabetes mellitus complicated with CKD and predicts the directions of future research in this field.

The Gut Microbiota Dysbiosis in Preeclampsia Contributed to Trophoblast Cell Proliferation, Invasion, and Migration via lncRNA BC030099/NF-κB Pathway.

Background: Preeclampsia (PE) is the main reason of maternal and perinatal morbidity and mortality. Gut microbiota imbalance in PE patients is accompanied by elevated serum lipopolysaccharide (LPS) levels, but whether it affects the occurrence and development of PE, the underlying mechanism is not clear. This paper intends to investigate the relationship between lncRNA BC030099, inflammation, and gut microbiota in PE. Methods: The feces of the patients were collected, and gut microbiota changes were assessed by 16S rRNA sequencing and pathway analysis by PICRUSt. Next, we examined LPS and lncRNA BC030099 levels in feces or placenta of PE patients. Then, we knocked down lncRNA BC030099 in HTR-8/SVneo cells and added the NF-κB pathway inhibitor JSH-23. CCK-8 and Transwell assays were performed to determine cell proliferation, migration, and invasion. Western blot was utilized to evaluate MMP2, MMP9, snail, and E-cadherin, p-IκBα, IκBα, and nuclear NF-κB p65 levels. IL-6, IL-1ß, and TNF-α levels were examined by ELISA. Results: Gut microbiota was altered in PE patients, and microbial genes associated with LPS biosynthesis were significantly elevated in gut microbiota in the PE group. LPS level in feces and placenta of PE group was significantly elevated. lncRNA BC030099 level in placenta of PE group was also notably promoted. Knockdown of lncRNA BC030099 promoted HTR-8/SVneo cell proliferation, migration, and invasion. Knockdown of lncRNA BC030099 also elevated MMP2, MMP9, and snail levels and repressed E-cadherin level. In addition, lncRNA BC030099 affected NF-κB pathway. Furthermore, NF-κB inhibitor reversed HTR-8/SVneo cell proliferation, invasion, and migration induced by LPS. Conclusions: The gut microbiota dysbiosis in PE contributed to HTR-8/SVneo cell proliferation, invasion, and migration via lncRNA BC030099/NF-κB pathway.

Antiviral treatment and prognosis in patients undergoing maintenance hemodialysis due to hepatitis C virus. / ç»´æŒæ€§è¡€æ¶²é€æžä¸™åž‹è‚ç‚Žç— æ¯’æ„ŸæŸ“æ‚£è€ çš„æŠ—ç— æ¯’æ²»ç–—åŠé¢„åŽ.

OBJECTIVES: Maintenance hemodialysis (MHD) is one of the important renal replacement therapies for patients with end-stage renal disease. Hepatitis C virus (HCV) infection is a serious global public health problem. The proportion of MHD patients complicated with HCV infection and the risk of adverse prognosis are higher than those in the general population. Active antiviral treatment and prevention of reinfection is a combined treatment by nephrology and infection physicians. It is a widely accepted preventive measure to set hemodialysis buffer area for patients in treating HCV infection, but its effectiveness and safety still need to be further explored. Thus, the aim of this study is to explore the antiviral treatment and prognosis of MHD patients with HCV infection during hemodialysis. METHODS: A retrospective analysis for renal disease patients at 10 end-stage with long-term hemodialysis in the HCV area of the Blood Purification Center of Xiangya Hospital, Central South University. After standard antiviral drug treatment, the patient reached the cure standard for HCV infection. The buffer zone was set up in the Blood Purification Center by the Department of Nephrology of Xiangya Hospital since April 2017. Patients cured of HCV infection were transferred from the HCV area to the buffer zone for continuous dialysis, accompanied by monitoring serum HCV-RNA, anti-HCV antibody levels and changes in clinical biochemical indicators following the status of reinfection. RESULTS: Ten patients with HCV infection were finally cured after antiviral treatment, and there were no significant changes in clinical biochemical indicators before and after treatment. In the followed-up period after the transfer, the patient continued to be negative for HCV-RNA and positive for anti-HCV antibody. CONCLUSIONS: Direct antiviral therapy is safe and effective in MHD patients with HCV infection. Active antiviral therapy and transferring to the buffer area for dialysis are new and effective treatment modes for HCV patients during MHD.

Oxidative stress contributes to vascular calcification in patients with chronic kidney disease.

Vascular calcification (VC) is a major cause of mortality in patients with chronic kidney disease (CKD). While elevations in serum phosphorus contribute to VC, we provide evidence here for a major role of oxidative stress (OS) in VC pathogenesis without an apparent increase in serum phosphorus in early CKD. In a rat model for stage 5 CKD (CKD5), we observed 1) robust increases of VC and OS, 2) significant reductions of smooth muscle 22 alpha (SM22α) and calponin, and 3) upregulations in Runt-related transcription factor 2 (RUNX2) and collagen I in vascular smooth muscle cells (VSMCs). Inhibition of OS using MnTMPyP dramatically reduced these events without normalization of hyperphosphatemia. In CKD5 patients with VC (n = 11) but not in those without VC (n = 13), OS was significantly elevated. While the serum levels of calcium and phosphate were not altered in the animal model for early stage CKD (ECKD), OS, VC, SM22α, calponin, RUNX2, collagen I and NADPH oxidase 1 (NOX1) in VSMCs were all significantly changed. More importantly, serum (5%) derived from patients with ECKD (n = 30) or CKD5 (n = 30) induced SM22α and calponin downregulation, and RUNX2, collagen I, NOX1 upregulation along with a robust elevation of OS and calcium deposition in primary rat VSMCs. These alterations were all reduced by MnTMPyP, ML171 (a NOX1 inhibitor), and U0126 (an inhibitor of Erk signaling). Collectively, we provide a comprehensive set of evidence supporting an important role of OS in promoting VC development in CKD patients (particularly in those with ECKD); this was at least in part through induction of osteoblastic transition in VSMCs which may involve the Erk singling. Our research thus suggests that reductions in OS may prevent VC in CKD patients.

The epidemiology and clinical information about COVID-19.

In December 2019, pneumonia of unknown cause occurred in Wuhan, Hubei Province, China. On 7 January 2020, a novel coronavirus, named as severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), was identified in the throat swab sample of one patient. The World Health Organization (WHO) announced the epidemic disease caused by SARS-CoV-2 as coronavirus disease 2019 (COVID-19). Currently, COVID-19 has spread widely around the world, affecting more than seventy countries. China, with a huge burden of this disease, has taken strong measures to control the spread and improve the curative rate of COVID-19. In this review, we summarized the epidemiological characteristics, clinical features, diagnosis, treatment, and prognosis of COVID-19. A comprehensive understanding will help to control the disease.

Role of Artificial Intelligence in Kidney Disease.

Artificial intelligence (AI), as an advanced science technology, has been widely used in medical fields to promote medical development, mainly applied to early detections, disease diagnoses, and management. Owing to the huge number of patients, kidney disease remains a global health problem. Challenges remain in its diagnosis and treatment. AI could take individual conditions into account, produce suitable decisions and promise to make great strides in kidney disease management. Here, we review the current studies of AI applications in kidney disease in alerting systems, diagnostic assistance, guiding treatment and evaluating prognosis. Although the number of studies related to AI applications in kidney disease is small, the potential of AI in the management of kidney disease is well recognized by clinicians; AI will greatly enhance clinicians' capacity in their clinical practice in the future.

Development of prognostic model for patients at CKD stage 3a and 3b in South Central China using computational intelligence.

BACKGROUND: Chronic kidney disease (CKD) stage 3 was divided into two subgroups by eGFR (45 mL/ min 1.73 m2). There is difference in prevalence of CKD, racial differences, economic development, genetic, and environmental backgrounds between China and Western countries. METHODS: We used a computational intelligence model (CKD stage 3 Modeling, CSM) to distinguish CKD stage 3 with CKD stage 3a/3b by data distribution rules, pearson correlation coefficient (PCC), spearman correlation (SCC) analysis, logistic regression (LR), random forest (RF), support vector machine (SVM), and neural network (Nnet) to develop Prognostic Model for patients with CKD stage 3a/3b in South Central China. Furthermore, we used RF to discover risk factors of progression of CKD stage 3a and 3b to CKD stage 5. 1090 cases of CKD stage 3 patients in Xiangya Hospital were collected. Among them, 455 patients progressed to CKD stage 5 in a median follow-up of 4 years (IQR 4.295, 4.489). RESULTS: We found that the common risk factors for progression of CKD stage 3a/3b to CKD stage 5 included albumin, creatinine, total protein, etc. Proteinuria, direct bilirubin, hemoglobin, etc. accounted for the progression from stage CKD stage 3a to stage 5. The risk factors for CKD stage 3b progression to stage 5 included low-density lipoprotein cholesterol, diabetes, eosinophil percentage, etc. CONCLUSIONS: CSM could be used as a point-of-care test to screen patients at high risk for disease progression, might allowing individualized therapeutic management.

Retrospective Analysis of Clinical Outcomes in Patients with Immunoglobulin A Nephropathy and Persistent Hematuria Following Renin-Angiotensin System Blockade.

BACKGROUND Recent guidelines recommend that patients with immunoglobulin A nephropathy (IgAN) and proteinuria 0.5-1 g/d and >1 g/d be treated with long-term renin-angiotensin system blockade (RASB). This study investigated whether patients with IgAN and persistent hematuria, but without proteinuria, can benefit from RASB. MATERIAL AND METHODS IgAN patients with persistent hematuria at four centers were recruited from January 2013 to December 2018. Patients were divided into those who did and did not receive long-term RASB. The primary outcome was the appearance of proteinuria, and the secondary outcomes were the decreased percentage of hematuria, rate of decline in estimated glomerular filtration rate (eGFR) and final blood pressure. The effects of RASB on these outcomes were assessed by multivariate Cox regression models and propensity score matching. RESULTS Of the 110 eligible patients, 44 (40.0%) received RASB and 66 (60.0%) did not. Treated patients had higher diastolic pressure. The unadjusted primary outcome, the appearance of proteinuria, was significantly less frequent in individuals who were than who were not treated with RASB. Multivariate Cox regression showed that RASB reduced the risk of the primary outcome and the levels of hematuria. The rate of eGFR decline and final blood pressure did not differ in the two groups. CONCLUSIONS RASB reduced the risk of proteinuria development and increased the remission of hematuria in patients with IgAN who presented with persistent hematuria alone. RASB, however, did not affect blood pressure in patients without hypertension and did not affect the rate of eGFR decline.

LncRNA ENST00000453774.1 contributes to oxidative stress defense dependent on autophagy mediation to reduce extracellular matrix and alleviate renal fibrosis.

Although long noncoding RNA (LncRNA) are important players in the initiation and progression of many pathological processes, the role of LncRNAENST00000453774.1 (LncRNA 74.1) in renal fibrosis still remains unclear. Lentivirus mediated LncRNA 74.1 overexpressing HK2 cells and overexpression mice models were constructed. HK2 cells induced by transforming growth factor-ß (TGF-ß) in vitro, and the mice UUO model in vivo were used to simulate renal fibrosis. The expression of LncRNA 74.1 was significantly downregulated in the TGF-ß-induced HK-2 cell fibrosis and clinical renal fibrosis specimens. LncRNA 74.1 overexpression obviously attenuated renal fibrosis in vitro and unilateral ureteral obstruction-induced renal fibrosis in vivo. LncRNA 74.1 promoted reactive oxygen species defense by activating prosurvival autophagy then decreased ECM-related proteins fibronectin and collagen I involved in renal fibrosis. We also found that Nrf2-keap1 signaling played important roles in the remission of ECM mediated by LncRNA 74.1. This study indicates that LncRNA 74.1 downregulation would contribute to renal fibrosis and its overexpression might represent a novel anti-fibrotic treatment in renal diseases.

Neutrophil-to-lymphocyte ratio and incident end-stage renal disease in Chinese patients with chronic kidney disease: results from the Chinese Cohort Study of Chronic Kidney Disease (C-STRIDE).

BACKGROUND: Chronic kidney disease (CKD) leads to end-stage renal failure and cardiovascular events. An attribute to these progressions is abnormalities in inflammation, which can be evaluated using the neutrophil-to-lymphocyte ratio (NLR). We aimed to investigate the association of NLR with the progression of end stage of renal disease (ESRD), cardiovascular disease (CVD) and all-cause mortality in Chinese patients with stages 1-4 CKD. METHODS: Patients with stages 1-4 CKD (18-74 years of age) were recruited at 39 centers in 28 cities across 22 provinces in China since 2011. A total of 938 patients with complete NLR and other relevant clinical variables were included in the current analysis. Cox regression analysis was used to estimate the association between NLR and the outcomes including ESRD, CVD events or all-cause mortality. RESULTS: Baseline NLR was related to age, hypertension, serum triglycerides, total serum cholesterol, CVD history, urine albumin to creatinine ratio (ACR), chronic kidney disease-mineral and bone disorder (CKD-MBD), hyperlipidemia rate, diabetes, and estimated glomerular filtration rate (eGFR). The study duration was 4.55 years (IQR 3.52-5.28). Cox regression analysis revealed an association of NLR and the risk of ESRD only in patients with stage 4 CKD. We did not observe any significant associations between abnormal NLR and the risk of either CVD or all-cause mortality in CKD patients in general and CKD patients grouped according to the disease stages in particular. CONCLUSION: Our results suggest that NLR is associated with the risk of ESRD in Chinese patients with stage 4 CKD. NLR can be used in risk assessment for ESRD among patients with advanced CKD; this application is appealing considering NLR being a routine test. Trial registration ClinicalTrials.gov Identifier NCT03041987. Registered January 1, 2012. (retrospectively registered) ( https://www.clinicaltrials.gov/ct2/show/NCT03041987?term=Chinese+Cohort+Study+of+Chronic+Kidney+Disease+%28C-STRIDE%29&rank=1 ).

The Protective Effect of Fluorofenidone against Cyclosporine A-Induced Nephrotoxicity.

BACKGROUND/AIMS: Cyclosporine A (CsA) is an immunosuppressant drug that is used during organ transplants. However, its utility is limited by its nephrotoxic potential. This study aimed to investigate whether fluorofenidone (AKF-PD) could provide protection against CsA-induced nephrotoxicity. METHODS: Eighty-five male Sprague-Dawley rats were divided into 5 groups: drug solvent, CsA, CsA with AKF-PD (250, 500 mg/kg/day), and CsA with pirfenidone (PFD, 250 mg/kg/day). Tubulointerstitial injury index, extracellular matrix (ECM) deposition, expression of type I and IV collagen, transforming growth factor (TGF)-ß1, platelet-derived growth factor (PDGF), Fas ligand (FASL), cleaved-caspase-3, cleaved-poly(ADP-ribose) polymerase (PARP)-1, and the number of transferase-mediated nick end-labeling (TUNEL)-positive renal tubule cells were determined. In addition, levels of TGF-ß1, FASL, cleaved-caspase-3, cleaved-PARP-1, and number of annexin V-positive cells were determined in rat proximal tubular epithelial cells (NRK-52E) treated with CsA (20 µmol/L), AKF-PD (400 µg/mL), PFD (400 µg/mL), and GW788388 (5 µmol/L). RESULTS: AKF-PD (250, 500 mg/kg/day) significantly reduced tubulointerstitial injury, ECM deposition, expression of type I and IV collagen, TGF-ß1, PDGF, FASL, cleaved-caspase-3, cleaved-PARP-1, and number of TUNEL-positive renal tubule cells in the CsA-treated kidneys. In addition, AKF-PD (400 µg/mL) significantly decreased TGF-ß1, FASL, cleaved-caspase-3, and PARP-1 expression in NRK-52E cells and further reduced the number of annexin V-positive cells. CONCLUSION: AKF-PD protect kidney from fibrosis and apoptosis in CsA-induced kidney injury.

Fluorofenidone attenuates interleukin-1ß production by interacting with NLRP3 inflammasome in unilateral ureteral obstruction.

AIM: We explored whether Fluorofenidone reduced interleukin-1ß (IL-1ß) production by interacting with NLRP3 inflammasome in unilateral ureteral obstruction (UUO). METHODS: Ureteral obstruction rats were treated with Fluorofenidone (500 mg/kg per day) for 3, 7 days. Morphologic analysis and leukocytes infiltration were assessed in ligated kidneys. Furthermore, plasmids of NLRP3, ASC, pro-Caspase-1, pro-IL-1ß were co-transfected into 293 T cells, and then treated with Fluorofenidone (2 mM). The expression of NLRP3, ASC, pro-caspase-1, cleavage caspase-1, pro-IL-1ß and cleavage IL-1ß were measured by Western blot or real-time PCR in vivo and in vitro. Moreover the interaction of NLRP3 inflammasome-assembly was detected by co-immunoprecipitation and confocal immunofluorescence. RESULTS: Fluorofenidone treatment significantly attenuated renal fibrosis and leukocytes infiltration in UUO model. Fluorofenidone had no effect on the expression of pro-IL-1ß. Interestingly, Fluorofenidone inhibited the activation of NLRP3 inflammasome, downregulated Caspase-1 levels and thereby decreased the cleavage of pro-IL-1ß into IL-1ß in vivo and in vitro. Fluorofenidone treatment distinctively weakened the interaction between NLRP3 and ASC, as well as ASC and pro-Caspase-1 in vivo. However, Fluorofenidone treatment only significantly weakened the interaction between ASC and pro-Caspase-1 in co-transfected 293 T cells. CONCLUSION: Fluorofenidone serves as a novel anti-inflammatory agent that attenuates IL-1ß production in UUO model by interacting with NLRP3 inflammasome.

Loss of the Protein Cystathionine ß-Synthase During Kidney Injury Promotes Renal Tubulointerstitial Fibrosis.

BACKGROUND/AIMS: Renal tubulointerstitial fibrosis (TIF) is the common pathway of progressive chronic kidney disease. Inflammation has been widely accepted as the major driving force of TIF. Cystathionine ß-synthase (CBS) is the first and rate-limiting enzyme in the transsulfuration pathway. CBS is considered to play protective role in liver and pulmonary fibrosis, but its role in TIF remains unknown. The purpose of this study was to investigate the potential role and mechanism of CBS in renal inflammation and TIF. METHODS: Renal function, tubulointerstitium damage index score, extracellular matrix (ECM) deposition, and the expressions of collagen I, collagen III, fibronectin, CD3, CD68, IL-1ß, TNF-α were measured in sham operation and unilateral ureteral obstruction (UUO) rats. Proteomics and gene array analysis were performed to screen differentially expressed molecules in the development of renal inflammation and TIF in UUO rats. The expression of CBS was detected in patients with obstructive nephropathy and UUO rats. We confirmed the expression of CBS using western blot and real-time PCR in HK-2 cells. Overexpression plasmid and siRNA were transfected specifically to study the possible function of CBS in HK-2 cells. RESULTS: Abundant expression of CBS, localized in renal tubular epithelial cells, was revealed in human and rat renal tissue, which correlated negatively with the progression of fibrotic disease. Expression of CBS was dramatically decreased in the obstructed kidney from UUO rats as compared with the sham group (SHM). In addition, knocking down CBS exacerbated extracellular matrix (ECM) deposition, whereas CBS overexpression attenuated TGF-ß1-induced ECM deposition in vitro. Inflammatory and chemotactic factors were also increased in CBS knockdown HK-2 cells stimulated by IL-1ß. CONCLUSIONS: These findings establish CBS as a novel inhibitor in renal fibrosis and as a new therapeutic target in patients with chronic kidney disease.

Clinical features and CKD-related quality of life in patients with CKD G3a and CKD G3b in China: results from the Chinese Cohort Study of Chronic Kidney Disease (C-STRIDE).

BACKGROUND: This study aimed to compare clinical features and health-related quality of life (HRQoL) in the Chinese chronic kidney disease (CKD) 3 population and determined the necessity of the subdivision of CKD3 in Chinese patients with CKD. METHODS: Participants with stage 3 CKD (18-74 years of age) were recruited at 39 clinical centers located at 28 cities in 22 provinces of China. The sociodemographic status, medical history, anthropometric measurements, and lifestyle behaviors were documented at entry, and blood and urine samples were collected. The estimated glomerular filtration rate was calculated using the CKD-EPI creatinine equation. The HRQoL was evaluated using the kidney disease quality-of-life instrument. A linear regression model was used to estimate the association between HRQoL and CKD stages (G3b vs G3a). RESULTS: The levels of intact parathyroid hormone, systolic blood pressure, uric acid, and high-density lipoprotein cholesterol were statistically significantly higher, whereas the levels of serum bicarbonate and hemoglobin were statistically significantly lower in the G3b group compared with the G3a group. Compared with CKD G3a group, the proportions of subjects with hyperuricemia and anemia were significantly higher in CKD G3b group (61.4% vs. 52.0% and 26.4% vs. 17.9%, respectively, P< 0.01). The HRQoL scores in "physical functioning (PCS)", "symptoms and problems", "effects of the kidney disease" and "burden of the kidney disease" were statistically significantly lower in the CKD G3b group compared with the CKD G3a group (90.88 ± 11.05 vs. 89.30 ± 11.52, 88.29 ± 11.94 vs. 86.49 ± 13.45, 55.86 ± 26.40 vs. 52.10 ± 27.64, 46.56 ± 8.16 vs. 44.51 ± 9.22, respectively, P< 0.01). Further, CKD G3b was associated with a lower score of physical functioning compared with G3a (regression coefficient =-1.12 [95%CI: -2.23, -0.16]). CONCLUSIONS: The preliminary results of this study suggested that modest differences existed in many important clinical features and KDQoL between patients with G3a and G3b CKD in a Chinese population. Also, a significant association between CKD3 subdivision of the disease and PCS was detected. Although further work is needed, we can speculate based on these results the CKD3 subdivision may be clinically meaningful for Chinese patients with CKD.

Fluorofenidone protects against renal fibrosis by inhibiting STAT3 tyrosine phosphorylation.

Signaling through the Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway, especially JAK2/STAT3, is involved in renal fibrosis. Fluorofenidone (FD), a novel pyridone agent, exerts anti-fibrotic effects in vitro and in vivo. Herein, we sought to investigate whether FD demonstrates its inhibitory function through preventing JAK2/STAT3 pathway. In this study, we examined the effect of FD on activation of rat renal interstitial fibroblasts, glomerular mesangial cells (GMC), and expression of JAK2/STAT3. Moreover, we explored the histological protection effects of FD in UUO rats, db/db mice, and phosphorylation of JAK2/STAT3 cascade. Our studies found that pretreatment with FD resulted in blockade of activation of fibroblast and GMC manifested by fibronectin (FN) and α-smooth muscle actin (α-SMA) protein expression and decline of STAT3 tyrosine phosphorylation induced by IL-6 or high glucose. In unilateral ureteral obstruction rats and a murine model of spontaneous type 2 diabetes (db/db mice), treatment with FD blocked the expression of FN and α-SMA, prevented renal fibrosis progression, and attenuated STAT3 activation. However, FD administration did not interfere with JAK2 activation both in vivo and in vitro. In summary, the molecular mechanism by which FD exhibits renoprotective effects appears to involve the inhibition of STAT3 phosphorylation.

Fluorofenidone attenuates oxidative stress and renal fibrosis in obstructive nephropathy via blocking NOX2 (gp91phox) expression and inhibiting ERK/MAPK signaling pathway.

BACKGROUND/AIMS: We evaluated the therapeutic effects of fluorofenidone (AKF-PD), a novel pyridone agent, targeting oxidative stress and fibrosis in obstructive nephropathy. METHODS: AKF-PD was used to treat renal interstitial fibrosis in unilateral ureteral obstruction (UUO) obstructive nephropathy in rats. The expression of NOX2 (gp91phox), fibronectin and extracellular signal regulated kinase (ERK) were detected by western blot. A level of Malondialdehyde (MDA), an oxidative stress marker, was measured by ELISA. In addition, ROS and the expressions of NOX2, collagen I (a1), fibronectin and p-ERK were measured in angiotensin (Ang) II-stimulated rat proximal tubular epithelial cells (NRK-52E) in culture. RESULTS: In NRK-52E cells, AKF-PD reduced AngII induced expressions of ROS, NOX2, fibronectin, collagen I (a1) and p-ERK. In UUO kidney cortex, AKF-PD attenuated the degree of renal interstitial fibrosis, which was associated with reduced the expressions of collagen I (a1) and fibronectin. Furthermore, AKF-PD downregulated the expressions of NOX2, MDA and p-ERK. CONCLUSION: AKF-PD treatment inhibits the progression of renal interstitial fibrosis by suppressing oxidative stress and ERK/MAPK signaling pathway.

Peroxiredoxin 1 inhibits the oxidative stress induced apoptosis in renal tubulointerstitial fibrosis.

AIM: Apoptosis is one of the most important mechanisms underlying renal tubulointerstitial fibrosis. We identified a role of protein Peroxiredoxin 1 (Prx1) in protecting apoptosis occurred in tubular epithelial cells of the rat and human kidney. METHODS: Immunohistochemistry (IHC) staining was used to detect Prx1 expression in kidney derived from unilateral-ureteral obstruction (UUO) rats or patients with obstructive nephropathy. Modulation of Prx1 expression by transfecting siRNA and overexpression plasmid approach were carried out in NRK-52E (rat kidney tubular epithelial cell line) cells. UUO-induced apoptosis was determined using TUNEL assay. RESULTS: Immunohistochemistry staining showed that Prx1 expressed in the cytoplasm of renal tubular epithelial cells, in the kidneys of UUO rats. The reduction was confirmed by both IHC and real-time polymerase chain reaction following a course of renal tubulointerstitial fibrosis in UUO rats and a decrease of Prx1 occurred concomitantly with an elevation of TUNEL-positive cells. Fluorofenidone (AKF-PD), a new anti-tubulointerstitial fibrotic agent, attenuated Prx1 reduction in UUO rats. Furthermore, hydrogen peroxide (H2 O2 )-derived oxidative stress activated p38 MAPK, and induced apoptosis in NRK-52E cells; knockdown of Prx1 sensitized both events in NRK-52E cells, and overexpression of Prx1 diminished the apoptosis and the phosphorylation of p38 CONCLUSION: Downregulation of Prx1 occurred in renal tubular epithelial cells of UUO rats and patients with obstructive nephropathy. Prx1 may alleviate the pathogenesis by inhibiting H2 O2 -induced apoptosis via inhibiting the p38 MAPK pathway. Prx1 may represent a useful target for a protective therapy towards renal tubulointerstitial fibrosis.

Expression of Niban in renal interstitial fibrosis.

AIM: Apoptosis is one of the most important mechanisms underlying renal interstitial fibrosis. We identified the role of protein Niban in apoptosis of tumour cells. The purpose of this study was to assess the expression of Niban in renal interstitial fibrosis of humans and rats. METHODS: Immunohistochemistry was used to detect Niban in patients with obstructive nephropathy. Proteomics and gene array analysis were performed to screen different molecules involved in the pathophysiology of unilateral-ureteral obstruction rats. We confirmed Niban using immunohistochemistry and Western blot in renal cortex of UUO rats and HK-2 cells. TUNEL assay and flow cytometry revealed apoptosis of renal tubular cells. siRNA and overexpression plasmid were transfected specifically to study the possible function of Niban. RESULTS: Niban was decreased apparently in renal tubular cells of patients with obstructive nephropathy, compared with controls. Niban decreased in renal cortex of UUO rats and transforming growth factor-ß1 (TGF-ß1)-stimulated HK-2 cells. siRNA of Niban increased apoptosis of HK-2 cells. TGF-ß1 also increased apoptosis of HK-2 cells. Overexpression of Niban failed to diminish apoptosis of HK-2 cells induced by TGF-ß1. CONCLUSIONS: Niban decreased in renal tubular cells of patients of obstructive nephropathy, UUO rats and TGF-ß1 stimulated HK-2 cells. Suppressing Niban increases apoptosis in HK-2 cells. Niban may be associated with apoptosis of HK-2 cells.

The prediction of in-hospital mortality in elderly patients with sepsis-associated acute kidney injury utilizing machine learning models.

Background: Sepsis-associated acute kidney injury (SA-AKI) is a severe complication associated with poorer prognosis and increased mortality, particularly in elderly patients. Currently, there is a lack of accurate mortality risk prediction models for these patients in clinic. Objectives: This study aimed to develop and validate machine learning models for predicting in-hospital mortality risk in elderly patients with SA-AKI. Methods: Machine learning models were developed and validated using the public, high-quality Medical Information Mart for Intensive Care (MIMIC)-IV critically ill database. The recursive feature elimination (RFE) algorithm was employed for key feature selection. Eleven predictive models were compared, with the best one selected for further validation. Shapley Additive Explanations (SHAP) values were used for visualization and interpretation, making the machine learning models clinically interpretable. Results: There were 16,154 patients with SA-AKI in the MIMIC-IV database, and 8426 SA-AKI patients were included in this study (median age: 77.0 years; female: 45%). 7728 patients excluded based on these criteria. They were randomly divided into a training cohort (5,934, 70%) and a validation cohort (2,492, 30%). Nine key features were selected by the RFE algorithm. The CatBoost model achieved the best performance, with an AUC of 0.844 in the training cohort and 0.804 in the validation cohort. SHAP values revealed that AKI stage, PaO2, and lactate were the top three most important features contributing to the CatBoost model. Conclusion: We developed a model capable of predicting the risk of in-hospital mortality in elderly patients with SA-AKI.