Silencing of keratin 1 inactivates the Notch signaling pathway to inhibit renal interstitial fibrosis and glomerular sclerosis in uremia.

Renal interstitial fibrosis is a key factor in the development of chronic renal diseases, possibly leading to uremia. The present study conducted aimed to assess the hypothesis whether keratin 1 (KRT1) silencing could suppress kidney interstitial fibrosis and glomerular sclerosis via the Notch pathway to alleviate uremic symptoms. Differentially expressed genes associated with uremia were identified using the gene expression omnibus (GEO) database. Uremic rat models were established, in which short hairpin-RNA against KRT1, activators, and inhibitors of the Notch pathway were transfected. To further validate the mechanism of KRT1 in uremia, KRT1 expression, cell apoptosis, glomerular area (GA), and glomerular capillary volume (GV), the score of glomerular sclerosis, and tubulointerstitial injury were assayed and investigated. GEO database revealed that KRT1 was upregulated in uremia and regulated the Notch pathway. GA, GV, cell apoptosis, glomerular sclerosis, and tubulointerstitial injury were typically located in more elevated levels of uremia in rats. KRT1 silencing and Notch pathway inhibition decreased the expression of Jagged1, Notch1, NICD1, Hey1, Hes1, α-SMA, and FN, which further resulted in decreased cell apoptosis, GA, GV, the score of glomerular sclerosis, and tubulointerstitial injury. Subsequently, the effect of KRT1 silencing on uremia was no longer evident once the Notch pathway was activated. The co-localization of high expression KRT1 and Notch1 was found in uremia. In summary, the results identified KRT1 as a key regulator in uremia progression, and KRT1 silencing can suppress glomerular sclerosis and tubulointerstitial injury via inactivation of the Notch pathway in uremic rats.

Effects of Long Non-Coding RNA LINC00963 on Renal Interstitial Fibrosis and Oxidative Stress of Rats with Chronic Renal Failure via the Foxo Signaling Pathway.

BACKGROUND/AIMS: Chronic renal failure (CRF) is usually associated with chronic diseases such as congestive heart failure and diabetes mellitus, the prevalence of which is increased with age. This study is designed to investigate the role of long intergenic non-coding RNA (lincRNA) LINC00963 in renal interstitial fibrosis (RIF) and oxidative stress (OS) of CRF via the forkhead box O (FoxO) signaling pathway. METHODS: Microarray data and annotated probe files related to CRF were downloaded by retrieving Gene Expression Omnibus (GEO) database to screen differentially expressed lncRNA. Multi Experiment Matrix (MEM) website and dual-luciferase reporter gene assay were used to predict and verify the target gene of LINC00963, and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis to identify the major signaling pathways involved. A total of 60 Wistar male rats were randomly selected and divided into the sham (n = 10) and model (n = 50) groups. Five rats in the sham group and thirty rats in the model group were sub-categorized into the control, blank, negative control (NC), LINC00963 vector, si-LINC00963, si-FoxO3, and si-LINC00963 + si-FoxO3 groups (n = 5). Reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blot analysis were performed to evaluate the expressions of LINC00963, FoxO3a, TGF-ß1, FN, GSH-PX, Bax, and Bcl-2. Measurement of changes in OS indexes including BUN, MDA, GSH-Px, SOD, and Na+-K+-ATP were conducted. Enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of inflammatory factors including TNF-α, IL-6, ICAM-1 and FN. TUNEL staining was performed to evaluate cell apoptosis. RESULTS: LINC00963 was highly expressed in CRF rats and FoxO3 was predicted and then verified as a target gene of LINC00963. FoxO3 gene participated in the FOXO signaling pathway. Compared with the blank and NC groups, there were significantly decreased expressions of LINC00963, TGF-ß1, FN, and Bax in the si-LINC00963 group, while increased expressions of GSH-PX, FoxO3a, and Bcl-2. The vitality values of BUN and MDA in the si-LINC00963 group declined, while enzymatic activities of GSH-Px, SOD and Na+-K+-ATP elevated in comparison to the blank and NC groups. The levels of TNF-α, IL-6, ICAM-1 and FN, and cell apoptosis rate in the si-LINC00963 group decreased in comparison to the blank and NC groups. All the results in the si-LINC00963 group were opposite in the LINC00963 vector and si-FoxO3 groups. CONCLUSION: Taken together, we conclude that down-regulation of LINC00963 suppresses RIF and OS of CRF by activating the FoxO signaling pathway.

Crucial genes associated with diabetic nephropathy explored by microarray analysis.

BACKGROUND: This study sought to investigate crucial genes correlated with diabetic nephropathy (DN), and their potential functions, which might contribute to a better understanding of DN pathogenesis. METHODS: The microarray dataset GSE1009 was downloaded from Gene Expression Omnibus, including 3 diabetic glomeruli samples and 3 healthy glomeruli samples. The differentially expressed genes (DEGs) were identified by LIMMA package. Their potential functions were then analyzed by the GO and KEGG pathway enrichment analyses using the DAVID database. Furthermore, miRNAs and transcription factors (TFs) regulating DEGs were predicted by the GeneCoDis tool, and miRNA-DEG-TF regulatory network was visualized by Cytoscape. Additionally, the expression of DEGs was validated using another microarray dataset GSE30528. RESULTS: Totally, 14 up-regulated DEGs and 430 down-regulated ones were identified. Some DEGs (e.g. MTSS1, CALD1 and ACTN4) were markedly relative to cytoskeleton organization. Besides, some other ones were correlated with arrhythmogenic right ventricular cardiomyopathy (e.g. ACTN4, CTNNA1 and ITGB5), as well as complement and coagulation cascades (e.g. C1R and C1S). Furthermore, a series of miRNAs and TFs modulating DEGs were identified. The transcription factor LEF1 regulated the majority of DEGs, such as ITGB5, CALD1 and C1S. Hsa-miR-33a modulated 28 genes, such as C1S. Additionally, 143 DEGs (one upregulated gene and 142 downregulated genes) were also differentially expressed in another dataset GSE30528. CONCLUSIONS: The genes involved in cytoskeleton organization, cardiomyopathy, as well as complement and coagulation cascades may be closely implicated in the progression of DN, via the regulation of miRNAs and TFs.

Prevalence and risk factors for pulmonary arterial hypertension in end-stage renal disease patients undergoing continuous ambulatory peritoneal dialysis.

BACKGROUND: Pulmonary arterial hypertension (PAH) is a major complication in renal failure patients, but very little information is available on the cardiovascular parameters in these patients. The prevalence and risk factors for PAH were systematically evaluated in patients with end-stage renal diseases (ESRD) undergoing continuous ambulatory peritoneal dialysis (CAPD). METHODS: Between January 2010 and January 2014, 177 ESRD patients (85 males and 92 females) undergoing CAPD therapy were recruited. General data, biochemical parameters and echocardiographic findings were collected and PAH risk factors studied. RESULTS: Study participants consisted of 65 patients (36.52%) with PAH (PAH group) and 112 patients without PAH (non-PAH group). The interdialytic weight gain, systolic blood pressure and diastolic blood pressure (DBP), mean arterial pressure and hypertensive nephropathy incidence in the PAH group were significantly higher than the non-PAH group (all p < 0.05). There were significant differences between PAH group and non-PAH group in C-reactive protein-positive rate, N-terminal pro-brain natriuretic peptide (NT-proBNP), hemoglobin, prealbumin and serum albumin levels (all p < 0.05). Compared with non-PAH group, PAH group showed significant increases in right ventricular internal diameter (RVID), right ventricular outflow tract diameter (RVOTD), main pulmonary artery diameter, left atrial diameter (LAD), left ventricular end-diastolic diameter, interventricular septal thickness, left ventricular mass index, early diastolic mitral annulus velocity and valve calcification incidence (all p < 0.05), and decreased left ventricular ejection fraction (LVEF), tricuspid annulus plane systolic excursion (TAPSE) and early diastolic blood flow peak and mitral annulus velocity (E/E') (all p < 0.05). Logistic regression analysis revealed that DBP, NT-proBNP, LAD, RVID, RVOTD, LVEF, TAPSE and E/E' are major risk factors for PAH. CONCLUSION: We observed a high incidence of PAH in ESRD patients undergoing CAPD. Logistic regression analysis revealed that DBP, NT-proBNP, LAD, RVID, RVOTD, LVEF, TAPSE and E/E' are high-risk factors for PAH in ESRD patients undergoing CAPD.

Hyperphosphorylation of tau protein in hippocampus of central insulin-resistant rats is associated with cognitive impairment.

BACKGROUND: Alzheimer's disease (AD) is one of the most common neurodegenerative diseases. Peripheral insulin resistance increases the risk for memory impairment and the development of AD. OBJECTIVE: This study aims to assess changes in cognitive functions and the level of hyperphosphorylated tau proteins in central insulin-resistant rats. METHODS: An in vivo central insulin-resistant (CIR) animal model was generated through intracerebroventricular injection of streptozotocin (STZ) into insulin-resistant (IR) rats that were induced by feeding a high-glucose/-protein/-fat diet. The Morris water maze test was used to assess changes in cognitive functions, pathological changes in the cornu ammonis 1 (CA1) region of the hippocampus were detected by immunohistochemistry, and the phosphorylation levels of tau proteins at specific sites were determined by Western blot analysis. RESULTS: The escape latency time in the Morris water maze test was significantly prolonged; the number of phosphorylated tau proteins in the CA1 region of the hippocampus was significantly increased; and the phosphorylation levels of tau proteins at Ser199, Thr205, Thr212, Thr217 and Ser396 were significantly elevated in the CIR group compared with the IR and control groups. CONCLUSION: This study provides direct evidence that CIR plays an important role in AD pathogenesis by facilitating tau hyperphosphorylation.

Pegmolesatide for the treatment of anemia in patients undergoing dialysis: a randomized clinical trial.

Background: Pegmolesatide, a synthetic peptide-based erythropoietin (EPO) receptor agonist, is being evaluated as an alternative to epoetin alfa for treating anemia of chronic kidney disease (CKD) in Chinese dialysis patients. There is a critical need for a long-acting, cost-effective erythropoiesis-stimulating agent that does not produce EPO antibodies. Methods: A randomized, open-label, active-comparator, non-inferiority phase three trial was conducted at 43 dialysis centers in China between May 17th, 2019, and March 28th, 2022. Eligible patients aged 18-70 years were randomly assigned (2:1) to receive pegmolesatide once every four weeks or epoetin alfa one to three times per week, with doses adjusted to maintain a hemoglobin level between 10.0 and 12.0 g/dL. The primary efficacy endpoint was the mean change in hemoglobin level from baseline to the efficacy evaluation period in the per-protocol set (PPS) population. Non-inferiority of pegmolesatide to epoetin alfa was established if the lower limit of the two-sided 95% confidence interval for the between-group difference was ≥ -1.0 g/dL. Safety assessment included adverse events and potential anaphylaxis reactions. This trial is registered at ClinicalTrials.gov, NCT03902691. Findings: Three hundreds and seventy-two patients were randomly assigned to the pegmolesatide group (248 patients) or the epoetin alfa group (124 patients). A total of 347 patients (233 in the pegmolesatide group and 114 in the epoetin alfa group) were included in the PPS population. In the PPS, the mean change (standard deviation, SD) in hemoglobin level from baseline to the efficacy evaluation period was 0.07 (0.92) g/dL in the pegmolesatide group and -0.22 (0.97) g/dL in the epoetin alfa group. The between-group difference was 0.29 g/dL (95% confidence interval: 0.11-0.47), verifying non-inferiority of pegmolesatide to epoetin alfa. Adverse events occurred in 231 (94%) participants in the pegmolesatide group and in 110 (89%) in the epoetin alfa group. Hypertension was the most common treatment-related adverse event. No fatal cases of anaphylaxis or hypotension were reported. Interpretation: Monthly subcutaneously injection of pegmolesatide was as effective and safe as conventional epoetin alfa administrated one to three times a week in treating anemia in Chinese dialysis patients. Funding: The study was supported by Hansoh Medical Development Group.

Effects of long non-coding RNA LINC00667 on renal tubular epithelial cell proliferation, apoptosis and renal fibrosis via the miR-19b-3p/LINC00667/CTGF signaling pathway in chronic renal failure.

The global prevalence of chronic renal failure (CRF) has significantly elevated with various reports indicating there to be a 10% worldwide rate. The functions of long non-coding RNAs (lncRNAs) and their deeper association with CRF at present remain poorly understood. Hence, the aim of the present study was to investigate the altered expressions of lncRNA LINC00667 in CRF and its associated effects on renal tubular epithelial cell proliferation, apoptosis and renal fibrosis through the microRNA-19b-3p (miR-19b-3p)/LINC00667/connective tissue growth factor (CTGF) signaling pathway. Initially, verification of the targeting relationship between LINC00667, CTGF and miR-19b-3p was performed, after which evidence was obtained indicating that miR-19b-3p could negatively regulate LINC00667 and CTGF. The expressions of CTGF in both the CRF and normal renal tissues were determined by immunohistochemistry means, with LINC00667 and CTGF determined to be highly expressed, while poor expression levels of miR-19b-3p were detected among the CRF tissues. The expressions of LINC00667, miR-19b-3p, fibrosis- and epithelial-mesenchymal transition (EMT)-related genes were also examined. The successfully established CRF rat models were treated with varying mimics, inhibitors, and siRNA. ELISA was applied to determine the renal function-related factors. Besides, the renal cell proliferation, migration and apoptosis were detected. In response to LINC00667 silencing, the renal tubular epithelial cells displayed increased proliferation and migration accompanied by reduced apoptosis based on upregulated miR-19b-3p, along with inhibited renal fibrosis and EMT detected. Taken together, the key findings of our study demonstrated that decreased lncRNA LINC00667 could promote renal tubular epithelial cell proliferation and ameliorate renal fibrosis in CRF via the miR-19b-3p/LINC00667/CTGF signaling pathway.

Associations of parathyroid hormone levels and mineral parameters with heart rate variability in patients with end-stage renal disease.

PURPOSE: Parathormone (PTH) is a very potent uraemic toxin, which affects calcium/phosphate homeostasis in patients with end-stage renal disease (ESRD). It also plays the role in uraemic autonomic neuropathy. The aim of the study was to investigate the relationship between elevated PTH levels and cardiac autonomic neuropathy assessed by frequency-domain measures of heart rate variability. METHODS: 24-h ECG was performed in 106 ESRD patients and 65 healthy controls. Very-low-frequency (VLF), low-frequency (LF) and high-frequency (HF) bands were computed. LF/HF ratio was calculated. RESULTS: We found that most heart rate variability indices were lower in ESRD patients than in healthy controls. Variables including demographics (age, sex, body mass index, dialysis vintage, systolic pressure, and diastolic pressure), laboratory values (Hb, Hct, glucose, Alb, and triglyceride), and bone metabolism panel (Ca, P, ALP, and iPTH) were selected as independent variables in the multivariable models. In multivariate analysis, serum intact PTH (iPTH) was correlated with mean normal-to-normal R-R intervals, mean heart rate, and VLF, serum calcium was correlated with standard deviation of 5-min average of normal R-R intervals (SDANN), and serum phosphorus was correlated with VLF and LF/HF. Serum iPTH was independently correlated with mean normal-to-normal R-R intervals (NN), mean HR, and VLF. Serum Ca was independently correlated with SDANN, and serum P was independently correlated with VLF and LF/HF. The results remained significant after the adjustment for iPTH. CONCLUSIONS: In conclusion, high PTH levels and disorders of mineral metabolism are associated with decreased heart rate variability in ESRD patients.

Effects of RNA interference-mediated gene silencing of VEGF on the ultrafiltration failure in a rat model of peritoneal dialysis.

We investigated the effects of RNAi-mediated gene silencing of vascular endothelial growth factor (VEGF) on ultrafiltration failure (UFF) in rats with peritoneal dialysis (PD). Sprague-Dawley (SD) male rats were classified into normal, sham operation, and uremic model groups. Uremic rats were subcategorized into uremia, PD2, VEGF shRNA-2, vector-2, PD2 + Endostar, PD4, VEGF shRNA-4, Vector-4, and PD4 + Endostar groups. Peritoneal Equilibration Test (PET) was conducted to assess ultrafiltration volume (UFV) and mass transfer of glucose (MTG). mRNA and protein expressions of VEGF were detected using quantitative real-time PCR (qRT-PCR) and Western blotting. Immunohistochemistry was performed to detect microvessel density (MVD). Compared with the normal group, decreased UFV and increased MTG were observed in rest of the groups. Compared with the uremia group, UFV decreased, while MTG, expression of VEGFs, and number of new blood capillaries increased in the PD2, Vector-2, PD4, and Vector-4 groups. The PD4 and Vector-4 groups exhibited lower UFV and higher MTG than the PD2 group. In the VEGF shRNA-2, PD2 + Endostar, VEGF shRNA-4, and in PD4 + Endostar group increased UFV, reduced MTG and expression of VEGF, and decreased number of new blood capillaries were detected. Compared with the PD4 group, in the VEGF shRNA-4 and PD4 + Endostar groups, UFV increased, MTG and expression of VEGF decreased, and number of new blood capillaries reduced. VEGF expression was negatively correlated with UFV, but positively correlated with MTG. The results obtained in the study revealed that down-regulation of VEGF by RNAi could be a novel target approach for the treatment of UFF.

Quercetin protects neuronal cells from oxidative stress and cognitive degradation induced by amyloid ß-peptide treatment.

The present study aimed to investigate the effect of quercetin on cytotoxicity and cognitive degradation induced by amyloid ß(Aß)­peptide in mice. Using the 1,1-diphenyl-2­picrylhydrazyl (DPPH) method and a Y­maze assay, the radical quenching ability and effect on working memory were determined, respectively, of quercetin treatment following 4 days of Aß administration. The acute oral toxicity was assessed used to determine the concentration of quercetin at which 50% lethality of the neuronal cells was induced. For determination of the effect of quercetin on degradation of learning and memory loss induced by Aß, a passive avoidance test was used. The results revealed that quercetin was involved in the inhibition of DPPH radical activity and was found to reduce radical activity by 76.5%. Quercetin significantly protected PC12 neuronal cells from death induced by Aß treatment. Treatment of mice with daily doses of 100 mg/kg body weight quercetin for 30 days significantly improved the degradation of learning and memory loss induced by Aß. The acute oral dose of quercetin in mice was determined to be 575 mg/kg body weight. Therefore, quercetin was found to be of therapeutic value for the treatment of neurological disorders, including AD, although further investigations are required.

Role of ESAT-6 in renal injury by regulating microRNA-155 expression via TLR4/MyD88 signaling pathway in mice with Mycobacterium tuberculosis infection.

The study aims to investigate the underlying mechanism involved in the early secretory antigenic target-6 (ESAT-6) in renal injury through regulation of the expression of miR-155 through the oll-like receptor (TLR)-4 (TLR4)/myeloid differentiation factor 88 (MyD88) signaling pathway in Mycobacterium tuberculosis (MTB)-infected mice. Sixty C57BL/6 mice with MTB-induced renal injury were randomly assigned into control, MTB, mimic, inhibitor, inhibitor + ESAT6, and inhibitor + ESAT6 + TAK242 groups. Body weight, the ratio of kidney weight to body weight (Kw/Bw), blood urea nitrogen (BUN), and serum creatinine (Scr) of mice were measured. Flow cytometry was used to detect renal activation in mice. Expressions of miR-155 and ESAT6 were detected by quantitative real-time PCR (qRT-PCR), and Western blotting was used to examine the expressions of ESAT6, TLR4, and MyD88. Expressions of tumor necrosis factor-α (TNF-α), interleukin-17 (IL-17), and interferon-γ (IFN-γ) were measured by qRT-PCR and ELISA. Compared with the control group, the BUN and Scr levels as well as the expression levels of miR-155, TLR4, MyD88, TNF-α, IL-17, and IFN-γ increased, while Kw/Bw decreased in the MTB and mimic groups. In comparison with the MTB group, the above indexes except Kw/Bw were elevated in the mimic group, but were reduced in the inhibitor group, while the Kw/Bw dropped in the mimic group but increased in the inhibitor group. Compared with the inhibitor group, the Kw/Bw decreased while the rest of the indexes increased in the inhibitor + ESAT6 group. ESAT6 may induce renal injury by promoting miR-155 expression through the TLR-4/MyD88 signaling pathway in MTB-infected mice.

Revealing the role of VEGFA in clear cell sarcoma of the kidney by protein-protein interaction network and significant pathway analysis.

Despite clear cell sarcoma of the kidney (CCSK) being the second most common renal tumor in children, its mechanism has not yet been fully investigated. The aim of the present study was to investigate the potential role of vascular endothelial growth factor A (VEGFA) in CCSK development. Following preprocessing of the original GSE2712 data, the differentially-expressed genes (DEGs) between 14 CCSK and 3 fetal kidney samples were identified through Significance Analysis of Microarrays, using the R package. Pathway enrichment analysis was then performed on the DEGs. A protein-protein interaction (PPI) network was constructed using the Search Tool for the Retrieval of Interacting Genes/Proteins database and the DEGs that were enriched in the most significant pathways. Following this, gene ontology analysis was performed on the VEGFA-associated genes, whilst transcription factor binding site analysis was conducted on the hot genes. A total of 2,681 DEGs, including 543 upregulated and 2,138 downregulated genes, were identified, and these were significantly enriched in pathways associated with cancer and focal adhesion. Furthermore, VEGFA, integrin ß1, integrin αV, v-akt murine thymoma viral oncogene homolog 1 and endothelial growth factor receptor were identified as hot genes in the PPI network. In addition, the upregulated VEGFA-associated genes, cyclin D1 and cyclin-dependent kinase inhibitor 1B, affected kinase regulation, and the downregulated VEGFA-associated genes, receptor tyrosine-protein kinase erbB-2, mesenchymal-epithelial transition tyrosine kinase receptor and kinase insert domain receptor, were enriched in the protein tyrosine kinase process. It was identified that VEGFA was regulated by restorer of fertility, erythromycin resistance methylase, GA binding protein subunit α, norepinephrine transporter, nuclear factor κB and Sp2 transcription factor genes. Overall, VEGFA and its associated genes serve important roles during CCSK development, and alongside transcription factors, they may function as novel therapeutic targets for disease treatment.

Blimp-1 siRNA inhibits B cell differentiation and prevents the development of lupus in mice.

Cumulative evidence suggest that B-lymphocytes play a role in the development of systemic lupus erythematosus (SLE). Thus, the therapeutic approach targeting specific B cells provides a promising way to treat SLE. Blimp-1 (B lymphocyte induced maturation protein), a transcriptional factor, controls the terminal differentiation of mature B cells to plasma cells. To explore the potential of Blimp-1 in the SLE development, we constructed the adenovirus encoding Blimp-1 siRNA, and injected it into BWF1 lupus mice. The results demonstrated that Blimp-1 siRNA decreased the Blimp-1 expression of B cells by regulating XBP-1 (X Box binding protein-1), BCMA (B-cell maturation antigen) expression through c-myc pathway. In addition, Blimp-1 siRNA eliminated anti-dsDNA antibody-producing plsma cells, reduced serum anti-dsDNA antibody levels and impeded the development of lupus. Therefore, our data provide the insight into the mechanism of Blimp-1 in SLE development and might represent a promising therapeutic strategy for autoantibody-mediated diseases.