Role of TFEB-autophagy lysosomal pathway in palmitic acid induced renal tubular epithelial cell injury.

Lysosomal dysfunction and impaired autophagic flux are involved in the pathogenesis of lipotoxicity in the kidney. Here, we investigated the role of transcription factor EB (TFEB), a master regulator of autophagy-lysosomal pathway, in palmitic acid induced renal tubular epithelial cells injury. We examined lipid accumulation, autophagic flux, expression of Ps211-TFEB, and nuclear translocation of TFEB in HK-2 cells overloaded with palmitic acid (PA). By utilizing immunohistochemistry, we detected TFEB expression in renal biopsy tissues from patients with diabetic nephropathy and normal renal tissue adjacent to surgically removed renal carcinoma (controls), as well as kidney tissues from rat fed with high-fat diet (HFD) and low-fat diet (LFD). We found significant lipid accumulation, increased apoptosis, accompanied with elevated Ps211-TFEB, decreased nuclear TFEB, reduced lysosome biogenesis and insufficient autophagy in HK-2 cells treated with PA. Kidney tissues from patients with diabetic nephropathy had lower nuclear and total levels of TFEB than that in control kidney tissues. Level of renal nuclear TFEB in HFD rats was also lower than that in LFD rats. Exogenous overexpression of TFEB increased the nuclear TFEB level in HK-2 cells treated with PA, promoted lysosomal biogenesis, improved autophagic flux, reduced lipid accumulation and apoptosis. Our results collectively indicate that PA is a strong inducer for TFEB phosphorylation modification at ser211 accompanied with lower nuclear translocation of TFEB. Impairment of TFEB-mediated lysosomal biogenesis and function by palmitic acid may lead to insufficient autophagy and promote HK-2 cells injury.

Prognosis and risk factors for cardiac valve calcification in Chinese end-stage kidney disease patients on combination therapy with hemodialysis and hemodiafiltration.

BACKGROUND: Cardiac valve calcification (CVC) is an important risk factor for cardiovascular complications. However, limited data are available concerning the prevalence, clinical features and risk factors for CVC in end-stage kidney disease (ESKD) patients. In this study, we aimed to assess these parameters in Chinese ESKD patients receiving combination therapy with hemodialysis and hemodiafiltration. METHODS: We conducted a cross-sectional study on 293 ESKD patients undergoing combination therapy of hemodialysis and hemodiafiltration at the First Affiliated Hospital of Chongqing Medical University from October 2014 to December 2015. CVC was evaluated via echocardiography. RESULTS: ESKD patients with CVC had a higher prevalence of diabetes mellitus, aortic and/or coronary artery calcification, arrhythmia, heart failure and coronary heart disease; increased systolic, diastolic and pulse pressure; longer duration of hemodialysis and hypertension; reduced hemoglobin, albumin and high-density lipoprotein cholesterol levels; and increased serum calcium and calcium-phosphorus product levels compared with those without CVC. Logistic regression analysis showed that increased dialysis duration (p = 0.006, OR = 2.25), serum calcium levels (p = 0.046, OR = 2.04) and pulse pressure (p < 0.001, OR = 3.22), the presence of diabetes (p = 0.037, OR = 1.81) and decreased serum albumin levels (p = 0.047, OR = 0.54) were risk factors for CVC. The correlation analysis indicated a significantly increased CVCs prevalence with an increase prevalence of heart failure, aortic and coronary artery calcification. CONCLUSIONS: CVC represents a common complication and a danger signal for cardiovascular events in ESKD patients undergoing combination therapy of hemodialysis and hemodiafiltration. The presence of diabetes, increased pulse pressure, long dialysis duration, hypoalbuminemia and high serum calcium levels were independent risk factors for CVC.

[A Cross-sectional Study of Osteoporosis and Cardiovascular Calcification in Patients with Chronic Kidney Disease at Different CKD Stages].

OBJECTIVE: To investigate the status of osteoporosis and cardiovascular calcification in patients with chronic kidney disease (CKD) with different stages, and analyze the correlation between the stages and markers of bone metabolism To correlation. METHODS: A total of 368 CKD patients at stage 3-5 who were treated in First Affiliated Hospital Affiliate to Chongqing Medical University and Chongqing Fuling Central Hospital from July 2017 to January 2018 were enrolled. A total of 60 healthy people who underwent physical examination in the hospital during the same period were enrolled as control group. Age, gender and body mass index (BMI) of all study objects at enrollment time were collected. The levels of estimate glomerular filtration rate (eGFR), serum calcium (Ca), phosphorus (P), albumin (ALB), intact parathyroid hormone (iPTH), bone alkaline phosphatase (BALP), procollagen Ⅰ N-terminal peptide (PINP) and ß-crosslaps (ß-CTX) were detected. The occurrence of osteoporosis, vascular calcification and heart valve calcification was detected. Pearson correlation analysis was applied to analyze correlation between eGFR, serum bone metabolism markers and osteoporosis, cardiovascular calcification. RESULTS: Compared with control group, levels of serum P, iPTH, BALP, PINP and ß-CTX were significantly increased in CKD stage 3-5 group ( P<0.05), while levels of eGFR and serum Ca were decreased ( P<0.05). With the increase of CKD staging, changes of their levels were more significant ( P<0.05). The incidence of vascular calcification and heart valve calcification in CKD stage 5 hemodialysis group was higher than that in CKD stage 3-4 group and CKD stage 5 without dialysis group ( P<0.05). eGFR was positively correlated with serum Ca in CKD patients at stage 3-5 ( P<0.05), while negatively correlated with serum P, iPTH, BALP, PINP and ß-CTX ( P<0.05). The occurrence of osteoporosis, vascular calcification and heart valve calcification was negatively correlated with increase of eGFR and serum Ca levels in CKD patients at stage 3-5 ( P<0.05), while positively correlated with increase of levels of serum P, iPTH, BALP, PINP and ß-CTX ( P<0.05). CONCLUSION: The levels of serum bone metabolism markers and eGFR are closely related to occurrence of osteoporosis and cardiovascular calcification in CKD patients at stage 3-5.

PINK1/Parkin mediated mitophagy ameliorates palmitic acid-induced apoptosis through reducing mitochondrial ROS production in podocytes.

Diabetic nephropathy (DN), the primary cause of end-stage renal disease (ESRD), is often accompanied by dyslipidemia, which is closely related to the occurrence and development of DN and even the progression to ESRD. Mitophagy, the selective degradation of damaged and dysfunctional mitochondria by autophagy, is a crucial mitochondrial quality control mechanism, and largely regulated by PINK1 (PTEN-induced putative kinase 1)/Parkin signaling pathway. In the present study, we demonstrated that PA induced mitochondrial damage and excessive mitoROS generation in podocytes. We also found PA treatment resulted in the activation of mitophagy by increasing co-localization of GFP-LC3 with mitochondria and enhancing the formation of mitophagosome, stabilization of PINK1 and mitochondrial translocation of Parkin, which indicated that PINK1/Parkin pathway was involved in PA-induced mitophagy in podocytes. Furthermore, inhibition of mitophagy by silencing Parkin dramatically aggravated PA-induced mitochondrial dysfunction, mitoROS production, and further enhanced PA-induced apoptosis of podocytes. Finally, we showed that PINK1/Parkin pathway were up-regulated in kidney of high fat diet (HFD)-induced obese rats. Taken together, our results suggest that PINK1/Parkin mediated mitophagy plays a protective role in PA-induced podocytes apoptosis through reducing mitochondrial ROS production and that enhancing mitophagy provides a potential therapeutic strategy for kidney diseases with hyperlipidemia, such as DN.

[Risk Factors of Acute Kidney Injury Complicating Adult Primary Nephrotic Syndrome].

Objective To explore the risk factors of acute kidney injury(AKI)in adult primary nephrotic syndrome(PNS). Methods Totally 185 patients with PNS were divided into AKI group(n=51)and non-AKI group(n=134).The demographic data and clinical and histological features at admission were compared between the two groups.The independent risk factors for AKI were evaluated by Logistics regression analysis. Results In 51 PNS patients with AKI,the common pathological types of AKI included minor glomerular abnormalities(29.4%),IgA nephropathy(25.5%),and membranous nephropathy(17.6%).The incidences of renal tubular casts and epithelial vacuoles in the AKI group were significantly higher than those in the non-AKI group(P=0.004,P=0.030).Males were more likely to suffer from AKI than females(P=0.000).Patients in AKI group had significantly lower albumin level(P=0.015)and higher levels of random urine protein,serum creatinine,uric acid,urea nitrogen,and triglyceride than non-AKI group(P=0.030,P=0.000,P=0.000,P=0.000,and P=0.006),and polyserous and oliguria occurred more often in the AKI group(P=0.000,P=0.002).The AKI group had significantly higher incidences of high blood pressure and infections(P=0.035,P=0.000).Multivariate logistics regression analysis showed albumin(<25 g/L),serum creatinine(>96 µmol/L),urea nitrogen(≥6.8 mmol/L),uric acid(≥400 µmol/L),diabetes,infection,and renal tubular casts were the independent risk factors for AKI. Conclusions AKI complicating PNS is associated with a variety of factors.Its independent risk factors include the levles of albumin,serum creatinine,urea nitrogen,and uric acid,diabetes,infections,and renal tubular casts.

Clinical characteristics and outcomes in microscopic polyangiitis patients with renal involvement: a study of 124 Chinese patients.

BACKGROUND: Microscopic polyangiitis (MPA) is a systemic autoimmune disease, and renal involvement is frequently present in MPA. MPA patients with renal involvement may have a worse prognosis. In this study, we aimed to evaluate the prognostic factors associated with all-cause death and renal survival in MPA patients with renal involvement. METHODS: A retrospective observational cohort study was performed. One hundred twenty-four patients newly diagnosed with MPA with renal involvement excluding end-stage renal disease (ESRD) who were hospitalized at the First Affiliated Hospital of Chongqing Medical University from January 2012 to July 2017 were included. All the survivors were followed up with until July 2018. The clinical and laboratory data at the time of the initial MPA diagnosis were collected, and the predictive values of the variables for mortality and renal outcome were analysed. RESULTS: Among the 124 patients, 52 were men (41.9%) and 72 were women (58.1%), and the age range was from 25 to 85 years (63.9±10.6 years). Seventy-six patients (61.3%) had pulmonary involvement. Multivariate Cox analysis revealed that age≥65 years (HR: 2.437; P=0.021), serum creatinine≥500 µmol/L (HR=2.207; P=0.009) and interstitial lung disease (ILD) (HR=2.366; P=0.013) were associated with mortality. Cox multivariate analysis identified that serum creatinine≥500 µmol/L (HR=8.236; P<0.001) and ILD (HR=2.649; P=0.001) were independent detrimental factors for renal survival, and immunosuppressive treatment was a protective factor for renal survival (HR=0.349; P=0.001). The area under the ROC curve (AUC) of the serum creatinine level at diagnosis was 0.705 for mortality and 0.870 for progression to ESRD or the doubling of serum creatinine. CONCLUSIONS: Age, serum creatinine level at diagnosis and ILD were independent predictors of mortality in MPA patients with renal involvement. Serum creatinine level at diagnosis, ILD and immunosuppressive treatment were independently related to renal survival.

Lipid Metabolism Disorder and Renal Fibrosis.

Since the lipid nephrotoxicity hypothesis was proposed in 1982, increasing evidence has supported the hypothesis that lipid abnormalities contributed to the progression of glomerulosclerosis. In this chapter, we will discuss the general promises of the original hypothesis, focusing especially on the role of lipids and metabolic inflammation accompanying CKD in renal fibrosis and potential new strategies of prevention.

Palmitic Acid-Induced Podocyte Apoptosis via the Reactive Oxygen Species-Dependent Mitochondrial Pathway.

BACKGROUND/AIMS: Chronic kidney disease (CKD) is often accompanied by hyperlipidemia, which accelerates progression of the disease. Podocyte injury can lead to dysfunction of the glomerular filtration barrier, which is associated with proteinuria, a risk marker for the progression of CKD. Our previous studies demonstrated that palmitic acid (PA) can induce podocyte apoptosis; however, the underlying mechanisms are unclear. In the present study, we investigated the specific molecular mechanisms of PA-induced apoptosis in cultured podocytes. METHODS: We cultured mouse podocytes and treated them with PA. Then, cell viability was measured using the Cell Counting Kit-8 colorimetric assay, lipid uptake was assessed by Oil Red O staining and boron-dipyrromethene staining, apoptosis was measured by flow cytometry, mitochondrial injury was assessed by JC-1 staining and transmission electron microscopy, and mitochondrial production of reactive oxygen species (ROS) was evaluated by fluorescence microscopy using the MitoSOX Red reagent. The effects of PA on the mitochondria-mediated caspase activation pathway were investigated by examining the expression of caspase-8, cleaved caspase-9, cleaved caspase-3, cleaved poly (ADP-ribose) polymerase (PARP), B-cell lymphoma 2 (Bcl-2), Bax, Bid, cytochrome c, and Fas-associated protein with death domain (FADD) using western blotting. The translocation of Bax and cytochrome c were detected by immunofluorescence. RESULTS: PA treatment significantly increased lipid accumulation and induced podocyte apoptosis. We investigated whether the two primary apoptosis signaling pathways (death receptor-mediated pathway and mitochondria-mediated pathway) were involved in the execution of PA-induced podocyte apoptosis, and found that the levels of FADD, caspase-8, and Bid did not significantly change during this process. Meanwhile, PA treatment induced an increase in Bax protein expression and a decrease in Bcl-2 protein expression, with Bax translocation to the mitochondria. Furthermore, PA treatment induced mitochondrial impairment, and triggered the release of cytochrome c from the mitochondria to cytosol, with a concomitant dose-dependent increase in the levels of cleaved caspase-9, cleaved caspase-3, and PARP. Meanwhile, PA treatment increased mitochondrial production of ROS, and the mitochondria-targeted antioxidant mitoTEMPO significantly ameliorated PA-induced podocyte apoptosis. CONCLUSION: Our findings indicated that PA induced caspase-dependent podocyte apoptosis through the mitochondrial pathway, and mitochondrial ROS production participated in this process, thus potentially contributing to podocyte injury.

Mucosal and systemic immunity in mice after intranasal immunization with recombinant Lactococcus lactis expressing ORF6 of PRRSV.

The purpose of the study was to construct mucosal vaccine of a recombinant Lactococcus lactis expressing PRRSV ORF6 gene and evaluate mucosal and systemic immune response against PRRSV in mice after intranasal immunization. The result show that the vaccine can stimulate mice to produce specific IgG in serum and remarkable special s-IgA in lung lavage fluid, at the same time, the contents of cytokines IL-2 and IFN-γ of the experimental group were significant higher than those of the control group (P < 0.01), however, the contents of cytokines IL-4 was not different to the all groups. In summary, the constructed mucosal vaccine can significantly induce mucosal immune, humoral immunity and cellular immunity involved Th1 type cytokines, which will lay a theoretical foundation on immune mechanism and new efficient vaccines for PRRSV.

Analysis of Traditional Chinese Medicine Symptoms in Children with Spastic Cerebral Palsy: A Data Mining Study.

Background: Cerebral palsy (CP) ranks as a major cause of motor disabilities in children, with spastic CP making up roughly 70-80% of all CP cases. The primary objective of our study is to identify characteristics of Traditional Chinese Medicine(TCM) symptom of spastic CP, thereby establishing correlations between the TCM symptom and the disease, providing a more scientific theoretical foundation for TCM treatments on spastic CP, enabling a deeper comprehension of clinical interventions, ultimately, improving rehabilitation outcomes in TCM treatment for spastic CP. Methods: We conducted a data mining study on TCM symptom of spastic CP children aged 4-14 years old treated at Xi'an Encephalopathy Hospital Affiliated to Shaanxi University of Chinese Medicine, from October 2021 to March 2023. The medical records of all eligible and complete spastic CP patients were extracted, processed for data cleansing, transformed, and subsequently analyzed to discern distinctive TCM symptom. K-Means Clustering Analysis and Association Rule Analysis were used for data mining. Results: Core symptoms identified for spastic CP encompassed "Motor Dysfunction", "Impaired Speech", "Delayed Development", "Limb Stiffness", "Rigidity in the limbs", "Intellectual Impairment", "Timidity and susceptibility to startle responses", "Muscle Wasting", and "Pale or Dull Complexion". Among the top-ranking associations of symptom, patterns emerge wherein "Motor dysfunction" intertwine with "Impaired speech", "Motor dysfunction" coexist with "Delayed development", and "Impaired speech" are accompanied by "Delayed development". Conclusion: This study identified the core symptom of spastic CP and tentatively suggests that the clinical manifestations of spastic CP are essentially consistent with the TCM pattern "liver exuberance and spleen weakness". This finding has facilitated the preliminary establishment of correlations between TCM pattern differentiation and the disease in medicine. It is anticipated that this correlation will bring tangible benefits to a larger number of children with spastic CP.

Activation of the Nrf2/ARE signaling pathway ameliorates hyperlipidemia-induced renal tubular epithelial cell injury by inhibiting mtROS-mediated NLRP3 inflammasome activation.

Dyslipidemia is the most prevalent independent risk factor for patients with chronic kidney disease (CKD). Lipid-induced NLRP3 inflammasome activation in kidney-resident cells exacerbates renal injury by causing sterile inflammation. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that modulates the cellular redox balance; however, the exact role of Nrf2 signaling and its regulation of the NLRP3 inflammasome in hyperlipidemia-induced kidney injury are poorly understood. In this study, we demonstrated that activation of the mtROS-NLRP3 inflammasome pathway is a critical contributor to renal tubular epithelial cell (RTEC) apoptosis under hyperlipidemia. In addition, the Nrf2/ARE signaling pathway is activated in renal tubular epithelial cells under hyperlipidemia conditions both in vivo and in vitro, and Nrf2 silencing accelerated palmitic acid (PA)-induced mtROS production, mitochondrial injury, and NLRP3 inflammasome activation. However, the activation of Nrf2 with tBHQ ameliorated mtROS production, mitochondrial injury, NLRP3 inflammasome activation, and cell apoptosis in PA-induced HK-2 cells and in the kidneys of HFD-induced obese rats. Furthermore, mechanistic studies showed that the potential mechanism of Nrf2-induced NLRP3 inflammasome inhibition involved reducing mtROS generation. Taken together, our results demonstrate that the Nrf2/ARE signaling pathway attenuates hyperlipidemia-induced renal injury through its antioxidative and anti-inflammatory effects through the downregulation of mtROS-mediated NLRP3 inflammasome activation.

Metabolomics study reveals blood biomarkers for early diagnosis of chronic kidney disease and IgA nephropathy: A retrospective cross-sectional study.

BACKGROUND AND AIMS: Chronic kidney disease (CKD) causes low quality of life and alarming morbidity and mortality. The crucial to retard CKD progression is to diagnose early for timely treatment. IgA nephropathy (IgAN) is a typical CKD and the most common glomerulonephritis. Both CKD and IgAN lack accurate and sensitive blood biomarkers for early diagnosis. Here we report the potential of plasma biomarkers for early diagnosis of CKD and IgAN. MATERIALS AND METHODS: Plasma levels of metabolites derived from tryptophan were quantified with an LC-MS/MS-based metabolomics for two cohorts. Based on the predictive probability of each metabolite, multivariate models including logistic regression and random forest were used to establish the early diagnostic biomarkers for CKD and IgAN. RESULTS: The plasma melatonin diagnosed early CKD (stages Ⅰ-Ⅱ) with an accuracy exceeding 95%, and a panel of melatonin and tryptophan achieved a remarkable 100% accuracy in diagnosing early CKD. Furthermore, indole-3-lactic acid had an excellent ability to distinguish IgAN among CKD patients. Based on the CKD screening and IgAN diagnosis primarily contributed by melatonin and indole-3-lactic acid, early IgAN could be diagnosed with an accuracy of over 85%. CONCLUSIONS: This study provides promising plasma biomarkers for early diagnosis of CKD and IgAN.

Analysis of Traditional Chinese Medicine Symptoms in Children with Spastic Cerebral Palsy, a Protocol for Data Mining.

Background: Cerebral palsy (CP) is characterized by abnormal pronunciation, posture, and movement. Clinically, CP can be categorized into various motor syndromes, including spastic hemiplegia, diplegia, quadriplegia, involuntary movement, ataxia, and mixed types. Among these, spastic CP represents over 70-80% of all CP cases. The primary objective of our study is to identify the top and core Traditional Chinese Medicine (TCM) symptoms and analysis their association rules in children with spastic cerebral palsy, thereby enhancing the theoretical foundations of TCM treatment on spastic CP. Methods: The study will be conducted on children aged 4 to 14 years with spastic CP who are undergoing treatment at Xi'an Encephalopathy Hospital Affiliated to Shaanxi University of Chinese Medicine. Basic information about the patients and their TCM symptoms will be collected on the first day of admission. This information will include age, gender, birth history, family history, disease classification, and TCM symptoms (including symptoms, tongue, and pulse). Once the data is collected, it will be exported from the electronic medical record system for further analysis. Descriptive statistics will be performed using Excel 2019, while exploratory factor analysis and cluster analysis will be conducted using SPSS Statistics 22. Additionally, association rule analysis will be carried out using SPSS Modeler 18. Results: This study will investigate the most top TCM symptoms in children with spastic CP and explore the association rules between these symptoms, mapping the presentation of spastic CP onto symptoms identified within TCM. Conclusion: Our findings will provide the distinctive characteristics of TCM symptoms in children with spastic CP, furnishing evidence-based support to clinicians and patients in making well-informed decisions collaboratively.

Acupuncture and Tuina Treatment for Gross Motor Function in Children with Spastic Cerebral Palsy: A Monocentric Clinical Study.

Objective: Cerebral palsy (CP) is a condition characterized by abnormal pronunciation, posture, and movement, particularly spastic CP, which involves Gross motor dysfunction due to increased muscle tone and stiffness. This monocentric clinical study aims to evaluate the effectiveness of acupuncture and tuina (AT) in improving gross motor function and alleviating associated symptoms in children diagnosed with spastic CP. Methods: A total of 83 eligible patients received AT treatment, while 85 patients received conventional rehabilitation treatment. Both groups underwent a 12-week treatment period following the research protocol. Pre- and post-treatment assessments included the Modified Ashworth Muscle Tension Scale (MAS), Gross Motor Function Measure (GMFM-D and GMFM-E), 6-min walking distance measurement (6MWD), and Modified Children's Functional Independence Rating Scale (WeeFIM). Results: After 12 weeks of treatment, when compared with baseline, the scores of MAS in both AT group and control group are decreased (p<0.01, p<0.01), the scores of GMFM-D, GMFME, 6MWD, WeeFIM in both group are increased (p<0.01 in all indicators). When compared with control group, AT group had significantly lower MAS scores compared to the control group (p<0.01), indicating reduced muscle tension. Moreover, AT group showed significantly higher scores in GMFM-D, GMFM-E, 6MWD, and WeeFIM compared to the control group (p<0.01 in all indicators), indicating improved gross motor function and functional independence. The study also revealed an inverse correlation between the children's age and treatment efficacy (r= -0.496, p<0.01 in AT group, r=-0.540, p<0.01 in control group), highlighting the importance of early intervention in the management of CP in children. Conclusion: These findings suggest that AT may effectively enhance gross motor function and alleviate associated symptoms in children diagnosed with spastic CP. Moreover, early initiation of treatment is crucial to maximize therapeutic efficacy in children with spastic CP. Trial Registration: Chinese Clinical Trial Registry, ChiCTR2200059823. Registered on 12 May 2022.

Activation of the Nrf2/ARE signaling pathway protects against palmitic acid-induced renal tubular epithelial cell injury by ameliorating mitochondrial reactive oxygen species-mediated mitochondrial dysfunction.

Chronic kidney disease (CKD) is often accompanied by dyslipidemia, and abnormal lipid metabolism in proximal tubule cells is considered closely related to the dysfunction of proximal tubule cells and eventually leads to accelerated kidney damage. Nuclear factor E2-related factor 2 (Nrf2), known as a redox-sensitive transcription factor, is responsible for regulating cellular redox homeostasis. However, the exact role of Nrf2 in dyslipidemia-induced dysfunction of proximal tubule cells is still not fully elucidated. In the present study, we showed that palmitic acid (PA) induced mitochondrial damage, excessive mitochondrial reactive oxygen species (ROS) (mtROS) generation, and cell injury in HK-2 cells. We further found that mtROS generation was involved in PA-induced mitochondrial dysfunction, cytoskeletal damage, and cell apoptosis in HK-2 cells. In addition, we demonstrated that the Nrf2/ARE signaling pathway was activated in PA-induced HK-2 cells and that silencing Nrf2 dramatically aggravated PA-induced mtROS production, mitochondrial damage, cytoskeletal damage and cell apoptosis in HK-2 cells. However, the mitochondrial antioxidant MitoTEMPOL effectively eliminated these negative effects of Nrf2 silencing in HK-2 cells under PA stimulation. Moreover, activation of the Nrf2/ARE signaling pathway with tBHQ attenuated renal injury, significantly reduced mtROS generation, and improved mitochondrial function in rats with HFD-induced obesity. Taken together, these results suggest that the Nrf2/ARE-mediated antioxidant response plays a protective role in hyperlipidemia-induced renal injury by ameliorating mtROS-mediated mitochondrial dysfunction and that enhancing Nrf2 antioxidant signaling provides a potential therapeutic strategy for kidney injury in CKD with hyperlipidemia.

Efficacy of short-term moderate or high-dose statin therapy for the prevention of contrast-induced nephropathy in high-risk patients with chronic kidney disease: systematic review and meta-analysis.

Although previous studies have indicated that statin therapy can effectively prevent the development of CIN, this observation remains controversial, especially in high-risk patients. A meta-analysis was performed to evaluate the efficacy of statin pretreatment for preventing the development of CIN in patients with chronic kidney disease (CKD) and to determine its effectiveness in various subgroups. We searched the online databases PubMed, EMBASE, and the Cochrane Library. RCTs that involved the comparison of the short-term moderate or high-dose statin pretreatment with placebo for CIN prevention in CKD patients undergoing angiography were included. The primary outcome was CIN prevalence. Seven RCTs comprising 4256 participants were investigated in this analysis. The risk of developing CIN in patients pretreated with statins was significantly lower than that in patients pretreated with placebo (RR=0.57, 95%CI=0.43-0.76, p=0.000). The SCr values of the statin group, when analyzed 48h after angiography were lower than those of the placebo group ((SMD=-0.15, 95% CI=-0.27 to -0.04, p=0.011). In the subgroup analysis, statin pretreatment could decrease the risk of CIN in CKD patients with DM (RR=0.54, 95% CI=0.39-0.76, p=0.000), but not in CKD patients without DM (RR=0.84, 95% CI=0.44-1.60, p=0.606). The efficacy of atorvastatin for preventing CIN was consistent with that observed with the use of rosuvastatin. The risk ratios (RR) were 0.51 (95% CI=0.32-0.81, p=0.004) and 0.60 (95% CI=0.41-0.88, p=0.009), respectively. Our study demonstrated that statin pretreatment could prevent the development of CIN in CKD patients. However, subgroup analysis demonstrated that statin pretreatment, despite being effective in preventing CIN in patients with CKD and DM, was not helpful for CKD patients without DM. Rosuvastatin and atorvastatin exhibited similar preventive effects with respect to CIN.

Berberine alleviates palmitic acid­induced podocyte apoptosis by reducing reactive oxygen species­mediated endoplasmic reticulum stress.

Lipid accumulation in podocytes can lead to the destruction of cellular morphology, in addition to cell dysfunction and apoptosis, which is a key factor in the progression of chronic kidney disease (CKD). Berberine (BBR) is an isoquinoline alkaloid extracted from medicinal plants such as Coptis chinensis, which has been reported to have a lipid­lowering effect and prevent CKD progression. Therefore, the present study aimed to investigate the effect of BBR on palmitic acid (PA)­induced podocyte apoptosis and its specific mechanism using an in vitro model. Cell death was measured using the Cell Counting Kit­8 colorimetric assay. Cell apoptotic rate was assessed by flow cytometry. The expression of endoplasmic reticulum (ER) stress­ and apoptosis­related proteins was detected by western blotting or immunofluorescence. Reactive oxygen species (ROS) were evaluated by 2',7'­dichlorofluorescein diacetate fluorescence staining. The results of the present study revealed that BBR treatment decreased PA­induced podocyte apoptosis. In addition, 4­phenylbutyric acid significantly reduced PA­induced cell apoptosis and the expression of ER stress­related proteins, which indicated that ER stress was involved in PA­induced podocyte apoptosis. In addition, N­acetylcysteine inhibited PA­induced excessive ROS production, ER stress and cell apoptosis of podocytes. BBR also significantly reduced PA­induced ROS production and ER stress in podocytes. These results suggested that PA mediated podocyte apoptosis through enhancing ER stress and the production of ROS. In conclusion, BBR may protect against PA­induced podocyte apoptosis, and suppression of ROS­dependent ER stress may be the key mechanism underlying the protective effects of BBR.

Breakdown of the gut barrier in patients with multiple organ dysfunction syndrome is attenuated by continuous blood purification: effects on tight junction structural proteins.

BACKGROUND: Breakdown of the gut barrier increases intestinal permeability and allows movement of intraluminal contents across the mucosa, which can lead to distant organ injury and multiple organ dysfunction syndrome (MODS). Intestinal permeability is associated with alterations in cellular tight junctions involving the structural proteins occludin and zonula occludens-1 (ZO-1). The aim of this study was to investigate the effect of continuous blood purification (CBP) on gut barrier function in patients with MODS. METHOD: Serum diamine oxidase (DAO) and endotoxin, epithelial monolayer permeability, and transepithelial electrical resistance (TER) were used as markers for the assessment of gut barrier function in 22 patients with MODS who underwent continuous venovenous hemofiltration (CWH) for 24 hours. Blood samples were taken from patients at 0, 6, 12, and 24 hours during CWH therapy. Serum DAO and endotoxin were determined by spectrophotography. Permeability and TER were assessed using Caco-2 cell monolayers. Occludin and ZO-1 protein levels were analyzed by immunoblotting and immunofluorescence staining. And inducible nitric oxide synthase (iNOS) mRNA levels and nitric oxide (NO) production were determined by real-time PCR and spectrophotography, respectively. RESULT: Gut barrier dysfunction was evident in patients with MODS compared with normal controls. Serum DAO, endotoxin levels, and epithelial permeability were elevated, while TER was decreased in patients with MODS, and this change was more pronounced in nonsurvivors. Breakdown and reorganization of occludin and ZO-1 away from tight junctions was found in all MODS patients. After CBP treatment, APACHE II and MODS scores improved significantly. Serum DAO and endotoxin levels and epithelial permeability also diminished, while TER increased in all patients; CBP significantly attenuated breakdown and reorganization of tight junction proteins, and also attenuated the inflammation-induced increase in iNOS mRNA expression and NO production. CONCLUSION: Breakdown of gut barrier function is present in patients with MODS and may be correlated with poor outcomes in the disease. CBP can not only improve the general conditions, as measured by the APACHE II score, but also improve gut barrier dysfunction by attenuating the breakdown and reorganization of occludin and ZO-1. This beneficial effect of CBP on gut barrier dysfunction is associated with down-regulation of iNOS.

Inhibition of soluble epoxide hydrolase attenuates renal tubular mitochondrial dysfunction and ER stress by restoring autophagic flux in diabetic nephropathy.

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease (ESRD), and renal tubular cell dysfunction contributes to the pathogenesis of DN. Soluble epoxide hydrolase (sEH) is an enzyme that can hydrolyze epoxyeicosatrienoic acids (EETs) and other epoxy fatty acids (EpFAs) into the less biologically active metabolites. Inhibition of sEH has multiple beneficial effects on renal function, however, the exact role of sEH in hyperglycemia-induced dysfunction of tubular cells is still not fully elucidated. In the present study, we showed that human proximal tubular epithelial (HK-2) cells revealed an upregulation of sEH expression accompanied by the impairment of autophagic flux, mitochondrial dysfunction, ubiquitinated protein accumulation and enhanced endoplasmic reticulum (ER) stress after high glucose (HG) treatment. Furthermore, dysfunctional mitochondria accumulated in the cytoplasm, which resulted in excessive reactive oxygen species (ROS) generation, Bax translocation, cytochrome c release, and apoptosis. However, t-AUCB, an inhibitor of sEH, partially reversed these negative outcomes. Moreover, we also observed increased sEH expression, impaired autophagy flux, mitochondrial dysfunction and enhanced ER stress in the renal proximal tubular cells of db/db diabetic mice. Notably, inhibition of sEH by treatment with t-AUCB attenuated renal injury and partially restored autophagic flux, improved mitochondrial function, and reduced ROS generation and ER stress in the kidneys of db/db mice. Taken together, these results suggest that inhibition of sEH by t-AUCB plays a protective role in hyperglycemia-induced proximal tubular injury and that the potential mechanism of t-AUCB-mediated protective autophagy is involved in modulating mitochondrial function and ER stress. Thus, we provide new evidence linking sEH to the autophagic response during proximal tubular injury in the pathogenesis of DN and suggest that inhibition of sEH can be considered a potential therapeutic strategy for the amelioration of DN.

Factors and Outcome of Renal Osteodystrophy-Associated Initial Fragility Fracture in End-Stage Renal Disease Patients.

BACKGROUND: Renal osteodystrophy has caused increased risk of fragility fracture in end-stage renal disease (ESRD) patients. However, risk factors and outcome of ESRD patients with fragility fracture remain uncharacterized. We aimed to assess these parameters in ESRD patients. SUMMARY: This retrospective case-control study analyzed 354 ESRD patients (initial fragility fracture [FF] group, n = 59; control group, n = 295). Pre-dialysis blood hemoglobin, serum albumin, lipid, calcium, phosphorus, alkaline phosphatase (ALP), and intact parathyroid hormone (iPTH) were collected. All procedures performed involving human participants were in accordance with the ethical standards of the institutional committee of The First Affiliated Hospital of Chongqing Medical University (IRB approval number 216-82), and informed consent was obtained from all participants. There were higher prevalence rates of primary hypertension and diabetes, higher serum ALP, corrected calcium, and lower serum total cholesterol, low-density lipoprotein, lipoprotein-α, and iPTH in the FF group. Fractures were more likely to occur in the higher level of corrected calcium as well as in the lower iPTH group. High corrected calcium (p = 0.010, OR = 11.308, 95% CI: 1.770-72.242) and serum ALP (p = 0.000, OR = 1.007, 95% CI: 1.004-1.011) were independent risk factors of fragility fracture. The incidence of all-cause mortality and cardiovascular (CV) events in ESRD patients with fragility fracture was higher than in those without fracture. KEY MESSAGES: Patients with hypertension, diabetes, excessive suppression of PTH, and poor nutritional status are more prone to fractures. Serum corrected calcium and ALP were independent risk factors of fragility fracture. Patients with initial fragility fracture had more CV events and higher mortality.