Knockdown of lncRNA MALAT1 attenuates renal interstitial fibrosis through miR-124-3p/ITGB1 axis

CRISPR/Cas9 based knockout of lncRNA MALAT1 attenuates TGF-β1 induced Smad 2/3 mediated fibrosis during AKI-to-CKD transition

Acute kidney injury (AKI) is a significant clinical issue with potential long-term consequences, as even a single episode can progress to chronic kidney disease (CKD). The AKI-to-CKD transition involves complex pathophysiology, including persistent inflammation, apoptosis, and fibrosis. Long noncoding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been recognized as a potential therapeutic target for various kidney diseases, including AKI and CKD. In our previous study, we conducted the transcriptomic analysis of lncRNAs in-vitro and animal models of AKI-to-CKD transition and found several dysregulated lncRNAs such as MALAT1, MEG3, NEAT1, MIAT, and H19 in this transition. Among these, we have selected lncRNA MALAT1 to further validate its role in AKI-to-CKD transition as a therapeutic target via a cluster regularly intercept short palindromic protein (CRISPR) associated protein 9 (Cas9)-mediated knockout approach in NRK52E cells. Guide RNAs (gRNAs) were designed to target MALAT1, and the PX459 turbo green fluorescence protein (GFP) plasmid containing MALAT1 gRNA1&2 was transfected into NRK52E cells using CRISPRMAX. Results demonstrated that MALAT1 knockout significantly reduced MALAT1 expression and attenuated Smad2/3-mediated fibrosis by decreasing pSmad2, pSmad2/3, Smad4, vimentin, fibronectin, collagen-I, and α-SMA expression levels, while increasing Smad7, Smurf2, and E-cadherin levels. These findings suggest that targeting the MALAT1/Smad2/3 pathway could be a potential therapeutic target for mitigating fibrosis to prevent AKI-to-CKD transition.

Immunological Features and Potential Biomarkers of Systemic Sclerosis-Associated Interstitial Lung Disease and Idiopathic Pulmonary Fibrosis

BACKGROUND

This study aims to summarize the similarities and differences in immune cell characteristics, and potential therapeutic targets between systemic sclerosis-associated interstitial lung disease (SSc-ILD) and idiopathic pulmonary fibrosis (IPF).

METHODS

This study included SSc-ILD and SSc-nonILD patients who were admitted to Beijing Chaoyang Hospital between April 4th, 2013, to June 30th, 2023. Publicly available datasets, including peripheral blood monocular cell (pbmc) single-cell data, SSc, SSc-ILD pbmc transcriptome data, and SSc-ILD, IPF lung tissue transcriptome data were analyzed. Statistical analyses were conducted using the SPSS and R software, employing standard statistical methods and bioinformatics packages such as Seurat, DESeq2, enrichR, and CellChat.

RESULTS

The results revealed that the CD4+/CD8+ T cell ratio of pbmc in SSc-ILD patients was significantly higher than in SSc-nonILD patients. In IPF patients, an elevated CD4+/CD8+ T cell ratio was also observed in progressive group, and Treg and mature CD4+ T cells might cause this change. JAK-STAT pathway and the cytokine-cytokine receptor interaction pathway were activated in peripheral blood T cells of IPF patients. The CD30, CD40, and FLT3 signaling pathways were found to play crucial roles in T cell interactions with other immune cells among IPF patients. SPA17 as a commonly upregulated gene among SSc, SSc-ILD, and IPF pbmc and lung, with its expression correlating positively with disease severity and lung function progression.

CONCLUSION

CD4+/CD8+ T cell ratio might associate with ILD initiation and progression; Treg cells and mature CD4+ T cells play key roles of it. SPA17 might serve as a pan-ILD marker and associated with lung function progression.

SMYD3 plays a pivotal role in mediating the epithelial-mesenchymal transition process in breast cancer

In previous reports, we highlighted the significant involvement of SMYD3, a histone methyltransferase (HMT), in various aspects of cancer progression, including cell adhesion, migration, and invasion. In this study, we delved deeper into understanding the relationship between SMYD3 and epithelial-mesenchymal transition (EMT) both in cell lines and clinical samples. Our investigation uncovered a notable correlation between heightened SMYD3 expression and the presence of EMT markers in human breast cancer tissues. We found that the induction of SMYD3 expression is facilitated by transforming growth factor beta 1 (TGF-β1), which achieves this by suppressing miR-124, an inhibitor that targets SMYD3, through alterations in DNA methylation. Conversely, our experiments demonstrated that reducing SMYD3 levels through RNA interference impeded TGF-β1-induced EMT in breast cancer cells. Furthermore, our results revealed that SMYD3 alone has the capability to modulate the expression of markers associated with EMT. An intriguing aspect of our study is the revelation that SMYD3 influences the activation of vimentin by binding to its response elements within the core promoter region. Notably, this effect is independent of SMYD3's histone methyltransferase activity. These findings collectively underscore the pivotal role of SMYD3 in driving EMT, both in cell lines and primary cancer tissues, particularly emphasizing its significance in TGF-β1-induced EMT in breast cancer.

miR-124-3p inhibits CRC proliferation, migration, and invasion by targeting ITGB1

Colorectal cancer (CRC) was the third most common cause of mortality associated with cancer globally. miR-124-3p has been widely acknowledged for its pivotal role as a tumor suppressor in various malignancies. In this study, we aimed to investigate the specific functions and underlying mechanisms of miR-124-3p in CRC cell proliferation, migration and invasion. A comprehensive set of assays, including CCK-8, colony formation, wound healing assays, flow cytometry, RT-qPCR and Western blotting, were conducted to assess the impact of miR-124-3p expression on CRC cell growth. Our investigations into miR-124-3p and its potential target gene ITGB1 were facilitated through bioinformatics analysis and dual-luciferase reporter assays. To further solidify our findings, rescue experiments were executed to validate the role of miR-124-3p in regulating the proliferation, migration, and apoptosis of CRC cells, genes involving Wnt/β-catenin signaling pathway were also detected. Our study revealed that the overexpression of miR-124-3p significantly suppressed both the proliferation and migratory capabilities of CRC cells, while its downregulation had the opposite effect. Notably, ITGB1 was identified as a putative target gene of miR-124-3p, exhibiting an inverse correlation with the expression levels of miR-124-3p. Moreover, the overexpression of ITGB1 was able to abrogate the inhibitory effects exerted by miR-124-3p overexpression on CRC cell proliferation, migration, and Wnt1/β-catenin protein levels. Our results reveal that miR-124-3p targets ITGB1 to regulate CRC cell proliferation and migration may be associated with the Wnt/β-catenin signaling pathway. These findings provide that a miR-124-3p/ITGB1 axis may be a potential target for the treatment of CRC.

LncRNA MALAT1 as a potential diagnostic and therapeutic target in kidney diseases

Long non-coding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript1 (MALAT1) has emerged as a crucial biomarker and therapeutic target for kidney diseases, including acute kidney injury (AKI), chronic kidney disease (CKD), diabetic kidney disease (DKD), lupus nephritis (LN), and renal cell carcinoma (RCC). LncRNAs are non-coding RNAs that have more than 200 nucleotides that play a crucial role in gene regulation at the post-translational stage, transcriptional, and epigenetic levels. LncRNA MALAT1 regulates gene expression and modulates cellular functions such as proliferation, inflammation, apoptosis, and fibrosis, which are key pathophysiology of kidney diseases. Overexpression of lncRNA MALAT1 has been consistently observed in kidney tissue, correlating with the severity and progression of kidney disease. In AKI, lncRNA MALAT1 exacerbates inflammation and tissue damage, contributing to disease progression. In CKD and DKD, lncRNA MALAT1 is implicated in the regulation of fibrosis by modulating key pathways, including focal adhesion kinase (FAK), toll-like receptor 4 (TLR4), NOD-like receptor protein3 (NLRP3), and nuclear factor kappa B (NF-κB), play pivotal roles in promoting disease progression. In LN, lncRNA MALAT1 has been linked to immune regulation and kidney damage, while in RCC, its role in promoting tumor growth and metastasis has been well documented. Preclinical research has demonstrated that therapeutic strategies targeting lncRNA MALAT1, such as knockdown and knockout, can reduce inflammation and fibrosis while improving kidney function. The fundamental role of lncRNA MALAT1 in kidney disease progression is yet to be fully understood. However, lncRNA MALAT1 has shown promise as a biomarker and therapeutic target to mitigate kidney disease development. This review highlights the potential of lncRNAs MALAT1 as diagnostic biomarkers and therapeutic targets, offering insights into a comprehensive approach to managing kidney diseases in the future.

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.

m6A modification in non-coding RNAs: Mechanisms and potential therapeutic implications in fibrosis

N6-methyladenosine (m6A) is one of the most prevalent and reversible forms of RNA methylation, with increasing evidence indicating its critical role in numerous physiological and pathological processes. m6A catalyzes messenger RNA(mRNA) as well as regulatory non-coding RNAs (ncRNAs), such as microRNAs, long non-coding RNAs, and circular RNAs. This modification modulates ncRNA fate and cell functions in various bioprocesses, including ncRNA splicing, maturity, export, and stability. Key m6A regulators, including writers, erasers, and readers, have been reported to modify the ncRNAs involved in fibrogenesis. NcRNAs affect fibrosis progression by targeting m6A regulators. The interactions between m6A and ncRNAs can influence multiple cellular life activities. In this review, we discuss the impact of the interaction between m6A modifications and ncRNAs on the pathological mechanisms of fibrosis, revealing the possibility of these interactions as diagnostic markers and therapeutic targets in fibrosis.

Long noncoding RNA MALAT1 as a ceRNA drives mouse fibroblast activation via the miR-335-3p/P2ry2 axis

Fibrosis is a complex pathological process that can lead to the permanent loss of biological function, with P2ry2 playing a crucial role in this process. Long non-coding RNAs (lncRNAs) have been reported to play an critically important role in the fibrotic process. However, it remains unclear whether lncRNAs can regulate fibrosis through P2ry2. In this study, we detected the expression of the long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (lnc-MALAT1). We investigated the expression patterns of lnc-MALAT1 and P2ry2 in denervated skeletal muscle, a classical model of fibrosis. Additionally, we utilized a TGF-β-mediated fibrosis model in NIH/3T3 cells to examine the effects of lnc-MALAT1 and P2ry2 on fibroblast activation and the underlying regulatory mechanisms in vitro. Our results demonstrated that the expression levels of lnc-MALAT1 and P2ry2 were consistently elevated in denervated skeletal muscle, correlating with the degree of fibrosis. In vitro experiments confirmed the regulatory effect of lnc-MALAT1 on P2ry2. Furthermore, we identified miR-335-3p as a potential key molecule in the regulatory relationship of lnc-MALAT1/P2ry2. Dual luciferase reporter assays and AGO2-RIP verified the molecular sponging effect of lnc-MALAT1 on miR-335-3p. Additionally, we validated the regulation of the lnc-MALAT1/miR-335-3p/P2ry2 axis through experimental approaches. In conclusion, our study identified a crucial role of lnc-MALAT1/miR-335-3p/P2ry2 axis in fibroblast activation, providing a promising treatment option against the fibrosis.

Research progress on miR-124-3p in the field of kidney disease

MicroRNAs (miRNAs) are 18-25 nucleotides long, single-stranded, non-coding RNA molecules that regulate gene expression. They play a crucial role in maintaining normal cellular functions and homeostasis in organisms. Studies have shown that miR-124-3p is highly expressed in brain tissue and plays a significant role in nervous system development. It is also described as a tumor suppressor, regulating biological processes like cancer cell proliferation, apoptosis, migration, and invasion by controlling multiple downstream target genes. miR-124-3p has been found to be involved in the progression of various kidney diseases, including diabetic kidney disease, calcium oxalate kidney stones, acute kidney injury, lupus nephritis, and renal interstitial fibrosis. It mediates these processes through mechanisms like oxidative stress, inflammation, autophagy, and ferroptosis. To lay the foundation for future therapeutic strategies, this research group reviewed recent studies on the functional roles of miR-124-3p in renal diseases and the regulation of its downstream target genes. Additionally, the feasibility, limitations, and potential application of miR-124-3p as a diagnostic biomarker and therapeutic target were thoroughly investigated.

SNHG16/miR-205/HDAC5 is involved in the progression of renal fibrosis

Renal interstitial fibrosis (RIF) represents an irreversible and progressive pathological manifestation of chronic renal disease, which ultimately leads to end-stage renal disease. Long noncoding RNAs (lncRNAs) have been suggested to be involved in the progression of RIF. Small nucleolar RNA host gene 16 (SNHG16), a member of lncRNAs, has been found to be involved in the progression of pulmonary fibrosis. This paper first researched the effect of SNHG16 on renal fibrosis. We established a unilateral ureteral obstruction (UUO)-induced mouse RIF model by ligation of the left ureter to evaluate the biological function of SNHG16 in RIF. As a result, SNHG16 was upregulated in UUO-induced renal fibrotic tissues. Knockdown of SNHG16 inhibited RIF and reduced alpha-smooth muscle actin (α-SMA), fibronectin, and college IV expression. miR-205 was a target of SNHG16, and downregulated in UUO-induced renal fibrotic tissues. Inhibition of miR-205 promoted RIF and increased the expression of α-SMA, college IV, and fibronectin. Overexpression of SNHG16 promoted the UUO-induced RIF, but miR-205 abrogated this effect of SNHG16. Histone deacetylase 5 (HDAC5) showed high expression in UUO-induced renal fibrotic tissues. Knockdown of HDAC5 significantly reduced α-SMA, fibronectin, and college IV expression in renal tissues of UUO-induced mice. Inhibition of miR-205 promoted HDAC5 expression, but knockdown of SNHG16 inhibited HDAC5 expression in renal tissues of UUO-induced mice. In conclusion, SHNG16 is highly expressed in renal fibrotic tissues of UUO-induced mice. Knockdown of SHNG16 may prevent UUO-induced RIF by indirectly upregulating HDAC5 via targeting miR-205. SHNG16 may be novel target for treating renal fibrosis.