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.

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.

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.

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.