Exosomal let-7b-5p deriving from parietal epithelial cells attenuate renal fibrosis through suppression of TGFßR1 and ARID3a in obstructive kidney disease.

As renal progenitor cells, parietal epithelial cells (PECs) have demonstrated multilineage differentiation potential in response to kidney injury. However, the function of exosomes derived from PECs has not been extensively explored. Immunofluorescent staining of Claudin-1 was used to identify primary PECs isolated from mouse glomeruli. Transmission electron microscopy, nanoparticle tracking analysis, and western blotting were used to characterize the properties of PECs-derived exosomes (PEC-Exo). The therapeutic role of PEC-Exo in tubulointerstitial fibrosis was investigated in the unilateral ureteral obstruction (UUO) mouse model and TGF-ß1-stimulated HK-2 cells. High-throughput miRNA sequencing was employed to profile PEC-Exo miRNAs. One of the most enriched miRNAs in PEC-Exo was knocked down by transfecting miRNA inhibitor, and then we investigated whether this candidate miRNA was involved in PEC-Exo-mediated tubular repair. The primary PECs expressed Claudin-1, PEC-Exo was homing to obstructed kidney, and TGF-ß1 induced HK-2 cells. PEC-Exo significantly alleviated renal inflammation and ameliorated tubular fibrosis both in vivo and in vitro. Mechanistically, let-7b-5p, highly enriched in PEC-Exo, downregulated the protein levels of transforming growth factor beta receptor 1(TGFßR1) and AT-Rich Interaction Domain 3A(ARID3a) in tubular epithelial cells (TECs), leading to the inhibition of p21 and p27 to restoring cell cycle. Furthermore, administration of let-7b-5p agomir mitigated renal fibrosis in vivo. Our findings demonstrated that PEC-derived exosomes significantly repressed the expression of TGFßR1 and ARID3a by delivering let-7b-5p, thereby alleviating renal fibrosis. This study provides novel insights into the role of PEC-Exo in the repair of kidney injury and new ideas for renal fibrosis intervention.

Targeting KLF2 as a Novel Therapy for Glomerular Endothelial Cell Injury in Diabetic Kidney Disease.

BACKGROUND: DKD is a microvascular disease, and glomerular endothelial cell injury is a key pathological event in DKD development. Through unbiased screening of glomerular transcriptomes, we previously identified KLF2 as a highly regulated gene in diabetic kidneys. KLF2 exhibits protective effects in endothelial cells by inhibiting inflammation, thrombotic activation, and angiogenesis, all of which are protective for cardiovascular disease. We previously demonstrated that endothelial cell-specific ablation of Klf2 exacerbated diabetes-induced glomerular endothelial cell injury and DKD in mice. Therefore in this study, we sought to assess the therapeutic potential of KLF2 activation in murine models of DKD. METHODS: We first examined the effects of endothelial cell-specific inducible overexpression of KLF2 (KLF2ov) in streptozotocin-induced diabetic mice. We developed small molecule KLF2 activators and tested whether increased KLF2 activity could impede DKD progression in type 2 diabetic db/db and BTBR ob/ob mice. RESULTS: Diabetic KLF2ov mice had attenuated albuminuria, glomerular endothelial cell injury, and diabetic glomerulopathy compared to control diabetic mice. Novel KLF2 activator, compound 6 (C-6) effectively induced downstream Nos3 expression and suppressed NF-kB activation in glomerular endothelial cells. The administration of C-6 improved albuminuria and glomerulopathy in db/db and BTBR ob/ob mice, which was associated with improved glomerular endothelial cell and podocyte injury. CONCLUSIONS: These results validate KLF2 as a potential drug target and KLF2 activators such as C-6 as a novel therapy for DKD.

Krüppel-like factor 2 is an endoprotective transcription factor in diabetic kidney disease.

Diabetic kidney disease (DKD) is a microvascular complication of diabetes, and glomerular endothelial cell (GEC) dysfunction is a key driver of DKD pathogenesis. Krüppel-like factor 2 (KLF2), a shear stress-induced transcription factor, is among the highly regulated genes in early DKD. In the kidney, KLF2 expression is mostly restricted to endothelial cells, but its expression is also found in immune cell subsets. KLF2 expression is upregulated in response to increased shear stress by the activation of mechanosensory receptors but suppressed by inflammatory cytokines, both of which characterize the early diabetic kidney milieu. KLF2 expression is reduced in progressive DKD and hypertensive nephropathy in humans and mice, likely due to high glucose and inflammatory cytokines such as TNF-α. However, KLF2 expression is increased in glomerular hyperfiltration-induced shear stress without metabolic dysregulation, such as in settings of unilateral nephrectomy. Lower KLF2 expression is associated with CKD progression in patients with unilateral nephrectomy, consistent with its endoprotective role. KLF2 confers endoprotection by inhibition of inflammation, thrombotic activation, and angiogenesis, and thus KLF2 is considered a protective factor for cardiovascular disease (CVD). Based on similar mechanisms, KLF2 also exhibits renoprotection, and its reduced expression in endothelial cells worsens glomerular injury and albuminuria in settings of diabetes or unilateral nephrectomy. Thus KLF2 confers endoprotective effects in both CVD and DKD, and its activators could potentially be developed as a novel class of drugs for cardiorenal protection in diabetic patients.

Inhibition of STAT3 by S3I-201 suppress peritoneal fibroblast phenotype conversion and alleviate peritoneal fibrosis.

Peritoneal fibrosis is a common pathological response to long-term peritoneal dialysis (PD) and a major cause for PD discontinuation. Understanding the cellular and molecular mechanisms underlying the induction and progression of peritoneal fibrosis is of great interest. In our study, in vitro study revealed that signal transducer and activator of transcription 3 (STAT3) is a key factor in fibroblast activation and extracellular matrix (ECM) synthesis. Furthermore, STAT3 induced by IL-6 trans-signalling pathway mediate the fibroblasts of the peritoneal stroma contributed to peritoneal fibrosis. Inhibition of STAT3 exerts an antifibrotic effect by attenuating fibroblast activation and ECM production with an in vitro co-culture model. Moreover, STAT3 plays an important role in the peritoneal fibrosis in an animal model of peritoneal fibrosis developed in mice. Blocking STAT3 can reduce the peritoneal morphological changes induced by chlorhexidine gluconate. In conclusion, our findings suggested STAT3 signalling played an important role in peritoneal fibrosis. Therefore, blocking STAT3 might become a potential treatment strategy in peritoneal fibrosis.

Characteristics of T cell premature senescence in maintenance hemodialysis patients.

BACKGROUND: Uremia-associated immunodeficiency, mainly characterized by T cell dysfunction, exists in patients on maintenance hemodialysis (MHD) and promotes systemic inflammation. However, T cell senescence, one of the causes of T cell dysfunction, has not been clearly revealed yet. In this cross-sectional research, we aimed to study the manifestation of T cell premature senescence in MHD patients and further investigate the associated clinical factors. METHODS: 76 MHD patients including 33 patients with cardiovascular diseases (CVD) and 28 patients with arteriovenous fistula (AVF) event history were enrolled in this study. Complementarity determining region 3 (CDR3) of T cell receptor (TCR) was analyzed by immune repertoire sequencing (IR-Seq). CD28- T cell subsets and expression of senescence marker p16 and p21 genes were detected by multicolor flow cytometry and RT-qPCR, respectively. RESULTS: MHD patients had significantly decreased TCR diversity (P < 0.001), increased CDR3 clone proliferation (P = 0.001) and a left-skewed CDR3 length distribution. The proportion of CD4 + CD28- T cells increased in MHD patients (P = 0.014) and showed a negative correlation with TCR diversity (P = 0.001). p16 but not p21 expression in T cells was up-regulated in MHD patients (P = 0.039). Patients with CVD exhibited increased expression of p16 and p21 genes (P = 0.010 and 0.004, respectively), and patients with AVF events showed further TCR diversity and evenness reduction (P = 0.002 and 0.017, respectively) compared to patients without the comorbidities. Moreover, age, average convection volume, total cholesterol, high-density lipoprotein cholesterol and transferrin saturation were associated with TCR diversity or CD4 + CD28- T cell proportion (P < 0.05). CONCLUSIONS: MHD patients undergo T cell premature senescence characterized by significant TCR diversity reduction and repertoire skew, as well as accumulation of the CD4 + CD28- subset and up-regulation of p16 gene. Patients with CVD or AVF events show higher level of immunosenescence. Furthermore, T cell senescence in MHD patients is associated with blood cholesterol and uremic toxin retention, suggesting potential intervention strategies in the future.

SARS-CoV-2 viral protein ORF3A injures renal tubules by interacting with TRIM59 to induce STAT3 activation.

Acute kidney injury occurs frequently in COVID-19 patients infected by the coronavirus SARS-CoV-2, and infection of kidney cells by this virus has been reported. However, little is known about the direct impact of the SARS-CoV-2 infection upon the renal tubular cells. We report that SARS-CoV-2 activated signal transducer and activator of transcription 3 (STAT3) signaling and caused cellular injury in the human renal tubular cell line. Mechanistically, the viral protein ORF3A of SARS-CoV-2 augmented both NF-κB and STAT3 signaling and increased the expression of kidney injury molecule 1. SARS-CoV-2 infection or expression of ORF3A alone elevated the protein level of tripartite motif-containing protein 59 (TRIM59), an E3 ubiquitin ligase, which interacts with both ORF3A and STAT3. The excessive TRIM59 in turn dissociated the phosphatase TCPTP from binding to STAT3 and hence inhibited the dephosphorylation of STAT3, leading to persistent STAT3 activation. Consistently, ORF3A induced renal injury in zebrafish and mice. In addition, expression of TRIM59 was elevated in the kidney autopsies of COVID-19 patients with acute kidney injury. Thus, the aberrant activation of STAT3 signaling by TRIM59 plays a significant role in the renal tubular cell injury caused by SARS-CoV-2, which suggests a potential targeted therapy for the renal complications of COVID-19.

Integrative ATAC-seq and RNA-seq analysis associated with diabetic nephropathy and identification of novel targets for treatment by dapagliflozin.

Dapagliflozin (DAPA) are clinically effective in improving diabetic nephropathy (DN). However, whether and how chromatin accessibility changed by DN responds to DAPA treatment is unclear. Therefore, we performed ATAC-seq, RNA-seq, and weighted gene correlation network analysis to identify the chromatin accessibility, the messenger RNA (mRNA) expression, and the correlation between clinical phenotypes and mRNA expression using kidney from three mouse groups: db/m mice (Controls), db/db mice (case group), and those treated with DAPA (treatment group). RNA-Seq and ATAC-seq conjoint analysis revealed many overlapping pathways and networks suggesting that the transcriptional changes of DN and DAPA intervention largely occured dependently on chromatin remodeling. Specifically, the results showed that some key signal transduction pathways, such as immune dysfunction, glucolipid metabolism, oxidative stress and xenobiotic and endobiotic metabolism, were repeatedly enriched in the analysis of the RNA-seq data alone, as well as combined analysis with ATAC-seq data. Furthermore, we identified some candidate genes (UDP glucuronosyltransferase 1 family, Dock2, Tbc1d10c, etc.) and transcriptional regulators (KLF6 and GFI1) that might be associated with DN and DAPA restoration. These reversed genes and regulators confirmed that pathways related to immune response and metabolism pathways were critically involved in DN progression.

Inhibition of ADAM17 attenuates high glucose-induced angiogenesis and inflammation in endothelial cells partly through down-regulation of GRO-α/CXCR2 expression: implications in peritoneal dialysis.

BACKGROUND: Angiogenesis and inflammation are key events leading to peritoneal morphologic alteration and ultrafiltration failure in patients undergoing peritoneal dialysis (PD). The current study aims to explore the role of ADAM17 in the angiogenetic and inflammatory responses of endothelial cells. METHODS: Human umbilical vein endothelial cells (HUVECs) were cultured and treated with a high glucose-containing medium. In parallel experiments, the expression of ADAM17 in HUVECs was inhibited by SiRNA interference. The mRNA and protein expression of ADAM17, GRO-α and CXCR2 were assessed by qPCR and Western blotting, respectively. The concentrations of GRO-α, VEGF, IL-6 and TNF-α in the cellular supernatants were determined by ELISA. Tube formation and migration of HUVECs were evaluated by Matrigel and transwell migration apparatus. RESULTS: High glucose increased the expression of ADAM17, CXCR2 and GRO-α in cultured HUVECs. RNA silencing of ADAM17 abolished high glucose-mediated increase of GRO-α and CXCR2, which were accompanied by reduced secretion of VEGF, IL-6, TNF-α, as well as tube formation and cell migration in HUVECs. CONCLUSIONS: Inhibition of ADAM17 ameliorates high glucose-induced angiogenic and inflammatory responses in endothelial cells partly through down-regulation of GRO-α/CXCR2 expression.

Hemodiafiltration with endogenous reinfusion for uremic toxin removal in patients undergoing maintenance hemodialysis: a pilot study.

OBJECTIVE: To delineate the efficacy and safety profile of hemodiafiltration with endogenous reinfusion (HFR) for uremic toxin removal in patients undergoing maintenance hemodialysis (MHD). METHODS: Patients who have been on MHD for a period of at least 3 months were enrolled. Each subject underwent one HFR and one hemodiafiltration (HDF) treatment. Blood samples were collected before and after a single HFR or HDF treatment to test uremic toxin levels and to calculate clearance rate. The primary efficacy endpoint was to compare uremic toxin levels of indoxyl sulfate (IS), λ-free light chains (λFLC), and ß2-microglobulin (ß2-MG) before and after HFR treatment. Secondary efficacy endpoints was to compare the levels of urea, interleukin-6 (IL-6), P-cresol, chitinase-3-like protein 1 (YKL-40), leptin (LEP), hippuric acid (HPA), trimethylamine N-oxide (TMAO), asymmetric dimethylarginine (ADMA), tumor necrosis factor-α (TNF-α), fibroblast growth factor 23 (FGF23) before and after HFR treatment. The study also undertook a comparative analysis of uremic toxin clearance between a single HFR and HDF treatment. Meanwhile, the lever of serum albumin and branched-chain amino acids before and after a single HFR or HDF treatment were compared. In terms of safety, the study was meticulous in recording vital signs and the incidence of adverse events throughout its duration. RESULTS: The study enrolled 20 patients. After a single HFR treatment, levels of IS, λFLC, ß2-MG, IL-6, P-cresol, YKL-40, LEP, HPA, TMAO, ADMA, TNF-α, and FGF23 significantly decreased (p < 0.001 for all). The clearance rates of λFLC, ß2-MG, IL-6, LEP, and TNF-α were significantly higher in HFR compared to HDF (p values: 0.036, 0.042, 0.041, 0.019, and 0.036, respectively). Compared with pre-HFR and post-HFR treatment, levels of serum albumin, valine, and isoleucine showed no significant difference (p > 0.05), while post-HDF, levels of serum albumin significantly decreased (p = 0.000). CONCLUSION: HFR treatment effectively eliminates uremic toxins from the bloodstream of patients undergoing MHD, especially protein-bound toxins and large middle-molecule toxins. Additionally, it retains essential physiological compounds like albumin and branched-chain amino acids, underscoring its commendable safety profile.

The relationship between thiamin, folic acid and cognitive function in a rat model of uremia.

End-stage renal disease is a worldwide health burden, but the pathogenesis of uremia-associated cognitive impairment (CI) is poorly recognized. We hypothesized that uremia brings about deficiency of thiamin and folic acid and causes CI by inducing oxidative stress. Therefore, 24 Sprague-Dawley rats were randomly divided into two groups: a 5/6 nephrectomy group (n = 12) and a sham-operated group (n = 12). The Morris water maze was used to assess the cognitive function eight weeks post-surgery, and serum levels of thiamin, folic acid and homocysteine were detected subsequently. Brain and kidney tissues were collected for pathological examination and 8-Hydroxy-2'-deoxyguanosine (8-OHdG) immunochemistry staining. Results showed that the escape latency on training days 1-2 was longer, and the time in quadrant IV on experimental day 6 was significantly shorter in 5/6 nephrectomy group. Meanwhile, the uremic rats showed decreased thiamin, folic acid and increased homocysteine. We also found the time in quadrant IV was positively correlated with thiamin and folic acid level, while negatively correlated with the blood urea nitrogen and 8-OHdG positive cell proportion. Furthermore, in 5/6 nephrectomy group, the hippocampal neuron count was significantly reduced, and a greater proportion of 8-OHdG positive cells were detected. Pretreating LPS-stimulated rat microglial cells with thiamin or folic acid in vitro alleviated the inflammatory impairment in terms of cell viability and oxidative stress. In summary, we applied a uremic rat model and proved that uremia causes serum thiamin and folic acid deficiency, homocysteine elevation, along with neuron reduction and severe oxidative stress in hippocampus, finally leading to CI.

Serum angiopoietin-2/angiopoietin-1 ratio is associated with cardiovascular and all-cause mortality in peritoneal dialysis patients: a prospective cohort study.

INTRODUCTION: Our objective was to examine the factors associated with the serum angiopoietin-2/angiopoietin-1 (Angpt-2/Angpt-1) ratio in peritoneal dialysis (PD) patients and to investigate the association between Angpt-2/Angpt-1 ratio and cardiovascular and all-cause mortality. METHODS: Patients on PD who were prevalent between January 2014 and April 2015 in the center of Renji Hospital were enrolled. At the time of enrollment, serum and dialysate samples were collected to detect biochemical parameters, serum angiopoietin-2 and angiopoietin-1 levels. Patients were dichotomized into two groups according to a median of Angpt-2/Angpt-1 ratio and followed up prospectively until the end of the study. RESULTS: A total of 325 patients were enrolled, including 168 males (51.7%) with a mean age of 56.9 ± 14.2 years and a median PD duration of 32.4 (9.8-55.9) months. Multiple linear regression showed pulse pressure (ß = 0.206, p < .001) and high-sensitivity C-reactive protein (hs-CRP) (ß = 0.149, p = .011) were positively correlated with serum Angpt-2/Angpt-1 ratio, while residual renal function (RRF) (ß= -0.219, p < .001) was negatively correlated with serum Angpt-2/Angpt-1 ratio. Multivariate Cox regression analysis showed the high serum Angpt-2/Angpt-1 ratio was an independent predictor of cardiovascular mortality (hazard ratio (HR)=2.467, 95% confidence interval (CI) 1.243-4.895, p = .010) and all-cause mortality (HR = 1.486, 95%CI 1.038-2.127, p = .031). In further subgroup analysis by gender, a significant association was shown in high Angpt-2/Angpt-1 ratio with all-cause mortality in male (p < .05), but not in female patients (p>.05). CONCLUSIONS: High Angpt-2/Angpt-1 ratio is an independent risk factor for cardiovascular and all-cause mortality in PD patients.

Adaptive immune dysfunction in patients with COVID-19 and impaired kidney function during the omicron surge.

BACKGROUND: Little is known about the characteristics of lymphocyte subsets and the association with patient outcomes in COVID-19 with and without impaired kidney function. METHODS: Lymphocyte subsets were compared in COVID-19 patients with or without kidney dysfunction. The primary outcome was a composite of all-cause mortality or intensive care unit admission. Secondary outcomes included duration of viral shedding, length of hospital stay, and acute kidney injury. RESULTS: Lymphocyte subset cell counts demonstrated the lowest in patients with severe/critical COVID-19 and kidney dysfunction. Among all lymphocyte subset parameters, Th cell count was the most significant indicator for outcomes. ROC of the combined model of Th cell count and eGFR presented better predictive value than that of the other parameters. Th cell count <394.5 cells/µl and eGFR <87.5 ml/min/1·73m2 were independently associated with poor outcomes. The propensity score matching analysis revealed consistent results. CONCLUSIONS: Reduced Th cell count and eGFR may be applied as promising predictive indicators for identifying COVID-19 patients with high risk and poor outcomes.

Exploration of Interstitial Fibrosis in Chronic Kidney Disease by Diffusion-Relaxation Correlation Spectrum MR Imaging: A Preliminary Study.

BACKGROUND: Renal interstitial fibrosis is one of the most common pathways in the progression of chronic kidney disease (CKD). Noninvasive evaluation of interstitial fibrosis would help monitoring CKD progression and prognosis prediction. PURPOSE: To evaluate the severity of renal interstitial fibrosis by diffusion-relaxation correlation spectrum imaging (DR-CSI). STUDY TYPE: Prospective. SUBJECTS: Forty patients with CKD and 10 healthy controls (average age 49.2 ± 14.8 years, 18 females). FIELD STRENGTH/SEQUENCE: 3-T, DR-CSI with 36 axial spin-echo echo-planar diffusion-weighted images (6 b-values, 6 echo times). ASSESSMENT: Interstitial fibrosis level (IFL) was assessed from biopsy results (IFL = 1, fibrosis percentage <25%, defined as mild; IFL = 2, 25%-50%, moderate; IFL = 3, >50%, severe). Estimated glomerular filtration rate (eGFR) was calculated using serum creatinine. The regions of interest included cortex for both kidneys. The diffusivity-T2 spectrum was assessed considering three compartments (threshold: T2 30-40 msec, diffusivity 5-9 µm2 /msec, according to visible peaks): A (low diffusivity, short T2), B (low diffusivity, long T2), and C (high diffusivity). Volume fractions Vi (i = A, B, C) were calculated. STATISTICAL TESTS: Intra-class coefficient (ICC, >0.6 as good) to assess inter-reader agreement of DR-CSI Vi . Spearman's correlation to assess relationship of Vi to IFL and eGFR. Receiver operating characteristic analyses with the area under the curve (AUC) to discriminate patients with moderate-severe fibrosis from mild ones. Statistical significance criteria: P-value <0.05. RESULTS: ICCs were good for all Vi . Correlations were found between IFL and VB (r = 0.424, significant) and VC (r = -0.400, significant), and between eGFR and VB (r = -0.303, P = 0.058) and VC (r = 0.487, significant). Regarding VB and VC , the AUCs were 0.903 and 0.824. DATA CONCLUSION: DR-CSI help distinguish patients with moderate or severe renal interstitial fibrosis from mild ones. EVIDENCE LEVEL: 2 Technical Efficacy: Stage 2.

Development and validation of the prediction model for mortality in patients with diabetic kidney disease in intensive care unit: a study based on medical information Mart for intensive care.

We aimed to explore factors associated with mortality of diabetic kidney disease (DKD), and to establish a prediction model for predicting the mortality of DKD. This was a cohort study. In total, 1,357 DKD patients were identified from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database, with 505 DKD patients being identified from the MIMIC-III as the testing set. The outcome of the study was 1-year mortality. COX proportional hazard models were applied to screen the predictive factors. The prediction model was conducted based on the predictive factors. A receiver operating characteristic (ROC) curve with the area under the curve (AUC) was calculated to evaluate the performance of the prediction model. The median follow-up time was 365.00 (54.50,365.00) days, and 586 patients (43.18%) died within 1 year. The predictive factors for 1-year mortality in DKD included age, weight, sepsis, heart rate, temperature, Charlson Comorbidity Index (CCI), Simplified Acute Physiology Score (SAPS) II, and Sequential Organ Failure Assessment (SOFA), lymphocytes, red cell distribution width (RDW), serum albumin, and metformin. The AUC of the prediction model for predicting 1-year mortality in the training set was 0.771 [95% confidence interval (CI): 0.746-0.795] and the AUC of the prediction model in the testing set was 0.795 (95% CI: 0.756-0.834). This study establishes a prediction model for predicting mortality of DKD, providing a basis for clinical intervention and decision-making in time.

The initial attempt at home hemodialysis in mainland China.

BACKGROUND: Observational studies have shown home hemodialysis (HHD) to be associated with better survival than facility hemodialysis (HD) and peritoneal dialysis (PD). Patients on HHD have reported higher quality of life and independence. HHD is considered to be an economical way to manage end-stage kidney disease (ESKD). The coronavirus disease 2019 pandemic has had a significant impact on patients with ESKD. Patients on HHD may have an advantage over in-center HD patients because of a lower risk of exposure to infection. PARTICIPANTS AND METHODS: We enrolled HD patients from our dialysis center. We first established the HHD training center. The training center was approved by the Chinese government. Doctors, nurses and engineers train and assess patients separately. There are three forms of patient monitoring: home visits, internet remote monitoring, and outpatient services. Demographic and medical data included age, sex, blood pressure, and dialysis-related data. Laboratory tests were conducted in our central testing laboratory, including hemoglobin (Hgb), serum creatinine (Cr), urea nitrogen (BUN), uric acid (UA), albumin (Alb), calcium (Ca), phosphorus (P), parathyroid hormone (PTH), and brain natriuretic peptide (BNP) levels. RESULTS: Six patients who underwent regular dialysis in the HD center of our hospital were selected for HHD training. We enrolled 6 patients, including 4 males and 2 females. The mean age of the patients was 47.5 (34.7-55.7) years, and the mean dialysis age was 33.5 (11.2-41.5) months. After an average of 16.0 (11.2-25.5) months of training, Alb, P and BNP levels were improved compared with the baseline values. After training, three patients returned home to begin independent HD. During the follow-up, there were no serious adverse events leading to hospitalization or death, but there were several adverse events. They were solved quickly by extra home visits of the technicians or online by remote monitoring. During the follow-up time, the laboratory indicators of all the patients, including Hgb, Alb, Ca, P, PTH, BNP, and ß2-MG levels, remained stable before and after HHD treatment. CONCLUSION: HHD is feasible and safe for ESKD in China, but larger-scale and longer-term studies are needed for further confirmation.

B-type natriuretic peptide levels and volume status in twice-weekly hemodialysis patients.

BACKGROUND: Twice-weekly hemodialysis (HD) could be regarded as an important part of incremental hemodialysis, volume status of this treatment model remains to be elucidated. METHODS: Patients undergoing regular twice-weekly or thrice-weekly hemodialysis in our unit on June 2015 were enrolled into the cohort study with an average of 2.02 years follow-up. Volume status of the subjects was evaluated by clinical characteristics, plasma B-type natriuretic peptide (BNP) levels and bioimpedance assessments with body composition monitor (BCM). Cox proportional hazards models and Kaplan-Meier analysis were used to compare patient survival between the two groups. RESULTS: Compared with patients on thrice-weekly HD, twice-weekly HD patients had significantly higher log-transformed BNP levels (2.54 ± 0.41 vs. 2.33 ± 0.49 pg/ml, p = 0.010). Overhydration (OH) and the ratio of overhydration to extracellular water (OH/ECW) in twice-weekly HD group were significantly higher than that of thrice-weekly HD (OH, 2.54 ± 1.42 vs. 1.88 ± 1.46, p = 0.033; OH/ECW, 0.17 ± 0.07 vs. 0.12 ± 0.08, p = 0.015). However, subgroup analysis of patients within 6 years HD vintage indicated that the two groups had similar hydration status. Multivariate Cox regression analysis showed that log-transformed BNP levels, serum albumin and diabetes status were predictors of mortality in hemodialysis patients. Kaplan-Meier survival analysis indicated that patients with BNP levels higher than 500 pg/ml had significantly worse survival compared with those with lower BNP levels (p = 0.014). CONCLUSIONS: Twice-weekly hemodialysis patients had worse volume status than that of thrice-weekly HD patients especially for those with long-term dialysis vintage, BNP level was a powerful predictor of mortality in HD patients.

A pilot study of thiamin and folic acid in hemodialysis patients with cognitive impairment.

OBJECTIVE: This study aimed to explore the effectiveness of thiamin and folic acid supplementation on the improvement of the cognitive function in patients with maintenance hemodialysis. METHOD: In the present study, we randomly assigned patients undergoing hemodialysis who had the Montreal Cognitive Assessment (MoCA) score lower than 26 to treatment group (n = 25, thiamin 90 mg/day combined with folic acid 30 mg/day) or control group (n = 25, nonintervention). All subjects were followed up for 96 weeks. The primary outcome was the improvement of the MoCA score. The secondary outcomes included homocysteine level, survival and safety. RESULTS: Patients in treatment group had an increase of the MoCA score from 21.95 ± 3.81 at baseline to 25.68 ± 1.96 at week 96 (p < 0.001, primary outcome), as compared with the MoCA score from 20.69 ± 3.40 to 19.62 ± 3.58 in control group. Thiamin combined with folic acid treatment also resulted in lower level of serum homocysteine in treatment group compare with control group at week 96 (p < 0.05, secondary outcome). 3 patients and 9 patients died during follow-up period in treatment and control group respectively (p = 0.048). The proportion of adverse events in treatment group was significantly lower than that in control group. CONCLUSION: Hemodialysis patients with cognitive impairment treated with thiamin and folic acid had a significant improvement in MoCA score.

NLRP3 inflammasome inhibition attenuates cisplatin-induced renal fibrosis by decreasing oxidative stress and inflammation.

BACKGROUND/AIMS: The NOD-like receptor, pyrin domain containing-3 (NLRP3) inflammasome is involved in the progression of chronic kidney disease in several rodent models. Here, we investigated whether a specific inhibitor of NLRP3 inflammasome, MCC950, can attenuate cisplatin-induced renal fibrosis. MATERIALS: Renal fibrosis was induced via a series of three injections of cisplatin to male C57BL/6 mice (7.5 mg/kg body weight). Activation of NLRP3 inflammasome was detected by immunoblotting, real-time PCR, and immunofluorescence. To validate the protective effect of NLRP3 inflammasome inhibition, MCC950(20 mg/kg body weight) was daily injected into multiple-cisplatin-treated mice intraperitoneally for 14 days, starting from 4 weeks after the first dose of cisplatin. NLRP3-/- mice were used to confirm the role of NLRP3 inflammasome in cisplatin-induced renal fibrosis. RESULTS: Mice were euthanized at 6 weeks after the first dose of cisplatin treatment. In multiple-cisplatin-induced murine model, renal fibrosis was accompanied by the activation of NLRP3 inflammasome. MCC950, the specific inhibitor of NLRP3 inflammasome, reduced cisplatin-induced renal dysfunction, tubular damage, interstitial collagen deposit, and the expression of profibrotic parameters. NLRP3 inhibition might protect against cisplatin-induced renal fibrosis through the alleviation of oxidative stress and inflammation. Furthermore, inhibition of NLRP3 inflammasome activation by deleting NLRP3 gene halted the progression of cisplatin-induced renal fibrosis. CONCLUSION: Inhibition of NLRP3 inflammasome attenuates renal fibrosis due to repeated cisplatin injections, and might be identified as a potential target for attenuating cisplatin-induced chronic kidney disease.

Reduction of mitochondria and up regulation of pyruvate dehydrogenase kinase 4 of skeletal muscle in patients with chronic kidney disease.

AIM: Muscle weakness is commonly among chronic kidney disease (CKD) patients. Muscle mitochondrial dysfunction and decreased pyruvate dehydrogenase (PDH) activity occur in CKD animals but have not been confirmed in humans, and changes in pyruvate dehydrogenase kinase (PDK) and pyruvate dehydrogenase phosphatase (PDP) expression have not been evaluated in CKD muscle. We presume that the reduction of muscle mitochondria and post-translational modification of PDH may cause muscle weakness in CKD patients. Herein, we explored changes in mitochondrial morphology, PDH expression and activity, and PDK/PDP expression in CKD patient muscle. METHODS: Twenty patients with stage 4-5 CKD (CKD group) and 24 volunteers (control group) were included. Clinical characteristics, biochemical information and handgrip strength (HGS) were determined. Skeletal muscle samples were collected from eight stage 5 CKD patients from CKD group. Other eight non-CKD surgical subjects' muscle samples were collected as control. PDH activity was determined using a PDH enzyme activity assay kit, and real-time PCR and western blotting analyses were performed to measure gene expression and protein levels, respectively. Transmission electron microscopy was used to study mitochondria morphology. RESULTS: CKD patients had lower HGS than non-CKD subjects, and HGS was correlated with gender, age, haemoglobin and albumin. Mitochondria were decreased in end-stage renal disease (ESRD) patients muscle. Mfn-1 expression and phospho-Drp1(S637)/Drp1 ratio were inhibited in the ESRD group, implicating dysfunctional mitochondrial dynamics. Muscle PDH activity and phospho-PDH(S293) were decreased in ESRD patient muscle, while PDK4 protein level was up regulated. CONCLUSION: Decreased mitochondria and PDH deficiency caused by up regulation of PDK 4 contribute to muscle dysfunction, and could be responsible for muscle weakness in CKD patients.

Use of Both Serum Cystatin C and Creatinine as Diagnostic Criteria for Cardiac Surgery-Associated Acute Kidney Injury and Its Correlation with Long-Term Major Adverse Events.

BACKGROUND/AIMS: Cardiac surgery-associated acute kidney injury (CSA-AKI) was traditionally defined as an increase in serum creatinine (sCr) after cardiac surgery. Recently, serum cystatin C (sCyC) has been proposed to be a better biomarker in the prediction of AKI. The clinical utility and performance of combining sCyC and sCr in patients with AKI, particularly for the prediction of long-term outcomes, remain unknown. METHODS: We measured sCyC together with sCr in 628 patients undergoing cardiac surgery. sCyC and sCr were assessed at baseline and 24 and 48 h after surgery. CSA-AKI determined by sCr (CSA-AKIsCr) was defined as an sCr increase greater than 0.3 mg/dL or 50% from baseline. Major adverse events (MAEs; including death of any cause and dialysis) at 3 years were assessed. RESULTS: CSA-AKIsCr developed in 178 patients (28.3%). Three-year follow-up was available for 621 patients; MAEs occurred in 42 patients (6.8%). An increase in sCyC concentration ≥30% within 48 h after surgery was detected in 228 patients (36.3%). This was the best sCyC cutoff for CSA-AKIsCr detection (negative predictive value = 88.8%, positive predictive value = 58.3%). To evaluate the use of both sCyC and sCr as CSA-AKI diagnostic criteria, we stratified patients into 3 groups: non-CSA-AKI, CSA-AKI detected by a single marker, and CSA-AKI detected by both markers. By multivariable logistic regression analysis, the independent predictors of MAEs at 3 years were group 2 (non-CSA-AKI group as the reference, CSA-AKI detected by a single marker: odds ratio [OR] = 3.48, 95% confidence interval [CI]: 1.27-9.58, p = 0.016), group 3 (CSA-AKI detected by both markers: OR = 5.12, 95% CI: 2.01-13.09; p = 0.001), and baseline glomerular filtration rate (OR = 2.24; 95% CI: 1.27-3.95; p = 0.005). CONCLUSION: Combining sCyC and sCr to diagnose CSA-AKI would be beneficial for risk stratification and prognosis in patients after cardiac surgery.