lncRNA TUG1 regulates hyperuricemia-induced renal fibrosis in a rat model

lncRNA TUG1 and kidney diseases

Long noncoding RNAs (lncRNAs) cover a large class of transcribed RNA molecules that are more than 200 nucleotides in length. An increasing number of studies have shown that lncRNAs control gene expression through different mechanisms and play important roles in a range of biological processes including growth, cell differentiation, proliferation, apoptosis, and invasion. TUG1 was originally discovered in a genomic screen of taurine-treated mouse retinal cells. Previous evidences pointed out that lncRNA TUG1 could inhibit apoptosis and the release of inflammatory factors, improve mitochondrial function, thereby protecting cells from damage, and showing a protective role of TUG1 in diseases. Given that TUG1 has multiple targets and can interfere with multiple steps in the oncogenic process, it has been proposed as a therapeutic target. In this review, we summarize the research progress of lncRNA TUG1 in kidney diseases in the past 8 years, and discuss its related molecular mechanisms.

LncRNA MALAT1 Knockdown Alleviates Fibrogenic Response in Human Endometrial Stromal Cells Via the miR-22-3p/TGFβR1/Smad2/3 Pathway

Intrauterine adhesion (IUA) resulting from irreversible fibrotic repair of endometrium is the main cause of secondary infertility in women, and current therapeutic approaches to IUA are limited. Increasing evidence has suggested the important role of competitive endogenous RNA (ceRNA) in IUA pathologies. This study aimed to investigate the long noncoding RNA (lncRNA) metastasis associated lung adenocarcinoma transcript 1 (MALAT1)-associated ceRNA in IUA development. We harvested endometrial tissues from patients with or without IUA and extracted endometrial stromal cells (ESCs) from normal endometrial tissues. Transforming growth factor β1 (TGF-β1) was used to induce fibrosis in ESCs. The expression of transforming growth factor β receptor 1 (TGFβR1), α-smooth muscle actin, phosphorylated suppressor of mother against decapentaplegic (p-Smad)2/3, collagen type I alpha 1, MALAT1, and microRNA (miR)-22-3p in endometrial tissues and ESCs was measured by reverse transcription quantitative polymerase chain reaction (RT-qPCR) or western blotting. Pearson's correlation analysis was conducted to assess the correlation between miR-22-3p expression or TGFβR1 and MALAT1 expression in endometrial tissues. The expression of TGFβR1 in ESCs was also evaluated by immunofluorescence staining. The location of MALAT1 was examined by fluorescence in situ hybridization. Luciferase reporter assays were performed to verify the binding relationship between MALAT1 or TGFβR1 and miR-22-3p. Cell viability was assessed via cell counting kit-8 assays. Our findings revealed that lncRNA MALAT1 and TGFβR1 were upregulated while miR-22-3p was downregulated in IUA endometrial tissues or TGF-β1-stimulated ESCs, and lncRNA MALAT1 expression was negatively correlated with miR-22-3p expression while being positively correlated with TGFβR1 expression in IUA endometrial tissues. Additionally, lncRNA MALAT1 was mainly located in the cytoplasm of ESCs and directly targeted miR-22-3p to regulate TGFβR1 expression. Moreover, knockdown of lncRNA MALAT1 exerted anti-fibrotic effects on ESCs by targeting miR-22-3p, and miR-22-3p overexpression inhibited the fibrosis of ESCs by binding to TGFβR1 3'untranslated region. Collectively, lncRNA MALAT1 promotes endometrial fibrosis by sponging miR-22-3p to regulate TGFβR1 and Smad2/3, and inhibition of MALAT1 may represent a promising therapeutic option for suppressing endometrial fibrosis.

Umbilical cord mesenchymal stem cell-derived exosomes inhibits fibrosis in human endometrial stromal cells via miR-140-3p/FOXP1/Smad axis

Endometrial fibrosis is the histologic appearance of intrauterine adhesion (IUA). Emerging evidences demonstrated umbilical cord mesenchymal stem cell-derived exosomes (UCMSC-exo) could alleviate endometrial fibrosis. But the specific mechanism is not clear. In this study, we explored the effect of UCMSC-exo on endometrial fibrosis, and investigated the possible role of miR-140-3p/FOXP1/Smad axis in anti-fibrotic properties of UCMSC-exo. UCMSC-exo were isolated and identified. Transforming growth factor-β (TGF-β) was used to induce human endometrial stromal cell (HESC) fibrosis. Dual luciferase assay was performed to verify the relationship between miR-140-3p and FOXP1. The expressions of fibrotic markers, SIP1, and p-Smad2/p-Smad3 in HESCs stimulated with UCMSC-exo were detected by western blot. In addition, the effects of miR-140-3p mimic, miR-140-3p inhibitor and FOXP1 over-expression on endometrial fibrosis were assessed. The isolated UCMSC-exo had a typical cup-shaped morphology and could be internalized into HESCs. The expressions of fibrotic markers were significantly increased by TGF-β, which was reversed by UCMSC-exo. MiR-140-3p in UCMSC-exo ameliorated TGf-β-induced HESCs fibrosis. FOXP1 was identified as the direct target of miR-140-3p, which could inversely regulate miR-140-3p's function on HESCs fibrosis. Furthermore, we demonstrated that miR-140-3p in UCMSC-exo regulated Smad signal pathway to exert the anti-fibrotic effect in HESCs. The anti-fibrotic effect of UCMSC-derived exosomes against HESC fibrosis was at least partially achieved by miR-140-3p/FOXP1/Smad axis.

Integrating Network Pharmacology and Experimental Validation to Reveal the Mechanism of Vine Grape Tea Polyphenols on Hyperuricemia-Induced Renal Injury in Mice

Hyperuricemia (HUA) is a metabolic disease and contributes to renal injury (RI). Vine grape tea polyphenols (VGTP) have been widely used to treat HUA and RI. However, the potential mechanism of VGTP activity remains unclear. To explore the underlying mechanism of VGTP treatment for HUA-induced RI based on network pharmacology that is confirmed by an in vivo study. All ingredients of VGTP were retrieved using a Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform and Comparative Toxicogenomics Database systems. The related targets of HUA and RI were obtained from GeneCards and National Center for Biotechnology Information (NCBI) databases. Some ingredients and targets were selected for molecular docking verification. One hour after administering potassium oxonate (300 mg/kg), VGTP (50, 100, and 200 mg/kg/d) was orally administered to HUA mice for 4 weeks. Histopathology and western blotting were performed in renal tissue. Our results showed that VGTP significantly reduced blood urea nitrogen, creatinine, uric acid, and significantly improved the RI and fibrosis of HUA mice. There were 54 active ingredients and 62 targets of HUA-induced RI. Further studies showed that VGTP decreased the expression of Bax, cleaved caspase 3, transforming growth factor-β (TGF-β1), CHOP, p-STAT3, and P53, and increased Bcl-2 expression in renal tissue. The related signaling pathways have apoptosis, TGF-β1, P53 and STAT, and endoplasmic reticulum stress (ERS). In this study, VGTP exerted antihyperuricemic and anti fibrosis effects by regulating the apoptosis and ERS signaling pathways. VGTP is expected to become a drug for combating HUA and RI.

Long non-coding RNAs: key regulators of liver and kidney fibrogenesis

Fibrosis is a pathological condition that is characterized by an abnormal buildup of extracellular matrix (ECM) components, such as collagen, in tissues. This condition affects various organs of the body, including the liver and kidney. Early diagnosis and treatment of fibrosis are crucial, as it is a progressive and irreversible process in both organs. While there are certain similarities in the fibrosis process between the liver and kidney, there are also significant differences that must be identified to determine molecular diagnostic markers and potential therapeutic targets. Long non-coding RNAs (lncRNAs), a class of RNA molecules that do not code for proteins, are increasingly recognized as playing significant roles in gene expression regulation. Emerging evidence suggests that specific lncRNAs are involved in fibrosis development and progression by modulating signaling pathways, such as the TGF-β/Smad pathway and the β-catenin pathway. Thus, identifying the precise lncRNAs involved in fibrosis could lead to novel therapeutic approaches for fibrotic diseases. In this review, we summarize lncRNAs related to fibrosis in the liver and kidney, and propose their potential as therapeutic targets based on their functions. [BMB Reports 2023; 56(7): 374-384].