The Roles and Mechanisms of lncRNAs in Liver Fibrosis

Emerging regulatory roles of noncoding RNAs induced by bisphenol a (BPA) and its alternatives in human diseases

Bisphenols (BPs), including BPA, BPF, BPS, and BPAF, are synthetic phenolic organic compounds and endocrine-disrupting chemicals. These organics have been broadly utilized to produce epoxy resins, polycarbonate plastics, and other products. Mounting evidence has shown that BPs, especially BPA, may enter into the human body and participate in the development of human diseases mediated by nuclear hormone receptors. Moreover, BPA may negatively affect human health at the epigenetic level through processes such as DNA methylation and histone acetylation. Recent studies have demonstrated that, as part of epigenetics, noncoding RNAs (ncRNAs), including microRNAs (miRNAs), long noncoding RNAs (lncRNAs), circular RNAs (circRNAs), and small nucleolar RNAs (snoRNAs), have vital impacts on BP-related diseases, such as reproductive system diseases, nervous system diseases, digestive system diseases, endocrine system diseases, and other diseases. Moreover, based on the bioinformatic analysis, changes in ncRNAs may be relevant to normal activities and functions and BP-induced diseases. Thus, we conducted a meta-analysis to identify more promising ncRNAs as biomarkers and therapeutic targets for BP exposure and relevant human diseases. In this review, we summarize the regulatory functions of ncRNAs induced by BPs in human diseases and latent molecular mechanisms, as well as identify prospective biomarkers and therapeutic targets for BP exposure and upper diseases.

Transcription factor YY1 accelerates hepatic fibrosis development by activating NLRP3 inflammasome-mediated pyroptosis

Hepatic fibrosis is the basis of multiple liver diseases and may eventually develop into hepatocellular carcinoma. Hepatic stellate cell (HSC) activation is a driving factor of hepatic fibrogenesis. In the liver microenvironment, liver cells and others play a crucial role in HSC activation. The liver tissues of CCl4-induced rats show excessive fibrosis, inflammation, and cell apoptosis. Yin Yang 1 (YY1) was highly expressed in hepatic fibrosis rats and TGF-β1-treated liver cells. In animal experiments, YY1 knockdown effectively attenuated CCl4-induced liver injury and pyroptosis-related IL-1β and IL-18 expression. In cellular experiments, NLRP3 inflammasome-mediated pyroptosis was activated by TGF-β1 treatment, while YY1 knockdown significantly inhibited the activation of the NLRP3 inflammasome, pyroptosis, and the secretion of IL-1β and IL-18. In addition, our data showed that TGF-β1-treated liver cell conditional medium markedly induced HSC activation, which was rescued by YY1 knockdown in liver cells. YY1 overexpression in liver cells contributed to the activation of TGF-β1-treated liver cell conditional medium in HSCs, however, this effect of YY1 was attenuated by NLRP3 inhibition. Overall, YY1 overexpression in liver cells contributed to HSC activation by facilitating IL-1β and IL-18 production via activating NLRP3 inflammasome-mediated pyroptosis, thus aggravating hepatic fibrogenesis. Our data indicate that YY1 may be a novel target for the treatment of hepatic fibrosis and associated liver diseases.

m6A epitranscriptomic and epigenetic crosstalk in liver fibrosis: Special emphasis on DNA methylation and non-coding RNAs

Liver fibrosis is a pathological process caused by a variety of chronic liver diseases. Currently, therapeutic options for liver fibrosis are very limited, highlighting the urgent need to explore new treatment approaches. Epigenetic modifications and epitranscriptomic modifications, as reversible regulatory mechanisms, are involved in the development of liver fibrosis. In recent years, researches in epitranscriptomics and epigenetics have opened new perspectives for understanding the pathogenesis of liver fibrosis. Exploring the epigenetic mechanisms of liver fibrosis may provide valuable insights into the development of new therapies for chronic liver diseases. This review primarily focus on the regulatory mechanisms of N6-methyladenosine (m6A) modification, non-coding RNA, and DNA methylation in organ fibrosis. It discusses the interactions between m6A modification and DNA methylation, as well as between m6A modification and non-coding RNA, providing a reference for understanding the interplay between epitranscriptomics and epigenetics.

Long non-coding RNAs; potential contributors in cancer chemoresistance through modulating diverse molecular mechanisms and signaling pathways

One of the mainstays of cancer treatment is chemotherapy. Drug resistance, however, continues to be the primary factor behind clinical treatment failure. Gene expression is regulated by long non-coding RNAs (lncRNAs) in several ways, including chromatin remodeling, translation, epigenetic, and transcriptional levels. Cancer hallmarks such as DNA damage, metastasis, immunological evasion, cell stemness, drug resistance, metabolic reprogramming, and angiogenesis are all influenced by LncRNAs. Numerous studies have been conducted on LncRNA-driven mechanisms of resistance to different antineoplastic drugs. Diverse medication kinds elicit diverse resistance mechanisms, and each mechanism may have multiple contributing factors. As a result, several lncRNAs have been identified as new biomarkers and therapeutic targets for identifying and managing cancers. This compels us to thoroughly outline the crucial roles that lncRNAs play in drug resistance. In this regard, this article provides an in-depth analysis of the recently discovered functions of lncRNAs in the pathogenesis and chemoresistance of cancer. As a result, the current research might offer a substantial foundation for future drug resistance-conquering strategies that target lncRNAs in cancer therapies.

Non‑coding RNA: A promising diagnostic biomarker and therapeutic target for esophageal squamous cell carcinoma (Review)

Esophageal cancer (EC) is a common form of malignant tumor in the digestive system that is classified into two types: Esophageal squamous cell carcinomas (ESCC) and esophageal adenocarcinoma. ESCC is known for its early onset of symptoms, which can be difficult to identify, as well as its rapid progression and tendency to develop drug resistance to chemotherapy and radiotherapy. These factors contribute to the high incidence of disease and low cure rate. Therefore, a diagnostic biomarker and therapeutic target need to be identified for ESCC. Non-coding RNAs (ncRNAs) are a class of molecules that are transcribed from DNA but do not encode proteins. Initially, ncRNAs were considered to be non-functional segments generated during transcription. However, with advancements in high-throughput sequencing technologies in recent years, ncRNAs have been associated with poor prognosis, drug resistance and progression of ESCC. The present study provides a comprehensive overview of the biogenesis, characteristics and functions of ncRNAs, particularly focusing on microRNA, long ncRNAs and circular RNAs. Furthermore, the ncRNAs that could potentially be used as diagnostic biomarkers and therapeutic targets for ESCC are summarized to highlight their application value and prospects in ESCC.

LncRNA NEAT1 in the pathogenesis of liver-related diseases

Nuclear paraspeckle assembly transcript 1 (NEAT1) is a long noncoding RNA (lncRNA) that is widely expressed in a variety of mammalian cell types. Altered expression levels of the lncRNA NEAT1 have been reported in liver-related disorders including cancer, fatty liver disease, liver fibrosis, viral hepatitis, and hepatic ischemia. lncRNA NEAT1 mostly acts as a competing endogenous RNA (ceRNA) to sponge various miRNAs (miRs) to regulate different functions. In regard to hepatic cancers, the elevated expression of NEAT1 has been reported to have a relation with the proliferation, migration, angiogenesis, apoptosis, as well as epithelial-mesenchymal transition (EMT) of cancer cells. Furthermore, NEAT1 upregulation has contributed to the pathogenesis of other liver diseases such as fibrosis. In this review, we summarize and discuss the molecular mechanisms by which NEAT1 contributes to liver-related disorders including acute liver failure, nonalcoholic fatty liver disease (NAFLD), liver fibrosis, and liver carcinoma, providing novel insights and introducing NEAT1 as a potential therapeutic target in these diseases.

Danhongqing formula alleviates cholestatic liver fibrosis by downregulating long non-coding RNA H19 derived from cholangiocytes and inhibiting hepatic stellate cell activation

OBJECTIVE

This study explores the mechanism of action of Danhongqing formula (DHQ), a compound-based Chinese medicine formula, in the treatment of cholestatic liver fibrosis.

METHODS

In vivo experiments were conducted using 8-week-old multidrug resistance protein 2 knockout (Mdr2-/-) mice as an animal model of cholestatic liver fibrosis. DHQ was administered orally for 8 weeks, and its impact on cholestatic liver fibrosis was evaluated by assessing liver function, liver histopathology, and the expression of liver fibrosis-related proteins. Real-time polymerase chain reaction, Western blot, immunohistochemistry and other methods were used to observe the effects of DHQ on long non-coding RNA H19 (H19) and signal transducer and activator of transcription 3 (STAT3) phosphorylation in the liver tissue of Mdr2-/- mice. In addition, cholangiocytes and hepatic stellate cells (HSCs) were cultured in vitro to measure the effects of bile acids on cholangiocyte injury and H19 expression. Cholangiocytes overexpressing H19 were constructed, and a conditioned medium containing H19 was collected to measure its effects on STAT3 protein expression and cell activation. The intervention effect of DHQ on these processes was also investigated. HSCs overexpressing H19 were constructed to measure the impact of H19 on cell activation and assess the intervention effect of DHQ.

RESULTS

DHQ alleviated liver injury, ductular reaction, and fibrosis in Mdr2-/- mice, and inhibited H19 expression, STAT3 expression and STAT3 phosphorylation. This formula also reduced hydrophobic bile acid-induced cholangiocyte injury and the upregulation of H19, inhibited the activation of HSCs induced by cholangiocyte-derived conditioned medium, and decreased the expression of activation markers in HSCs. The overexpression of H19 in a human HSC line confirmed that H19 promoted STAT3 phosphorylation and HSC activation, and DHQ was able to successfully inhibit these effects.

CONCLUSION

DHQ effectively alleviated spontaneous cholestatic liver fibrosis in Mdr2-/- mice by inhibiting H19 upregulation in cholangiocytes and preventing the inhibition of STAT3 phosphorylation in HSC, thereby suppressing cell activation. Please cite this article as: Li M, Zhou Y, Zhu H, Xu LM, Ping J. Danhongqing formula alleviates cholestatic liver fibrosis by downregulating long non-coding RNA H19 derived from cholangiocytes and inhibiting hepatic stellate cell activation. J Integr Med. 2024; 22(2): 188-198.

Epigenetic modification in liver fibrosis: Promising therapeutic direction with significant challenges ahead

Liver fibrosis, characterized by scar tissue formation, can ultimately result in liver failure. It's a major cause of morbidity and mortality globally, often associated with chronic liver diseases like hepatitis or alcoholic and non-alcoholic fatty liver diseases. However, current treatment options are limited, highlighting the urgent need for the development of new therapies. As a reversible regulatory mechanism, epigenetic modification is implicated in many biological processes, including liver fibrosis. Exploring the epigenetic mechanisms involved in liver fibrosis could provide valuable insights into developing new treatments for chronic liver diseases, although the current evidence is still controversial. This review provides a comprehensive summary of the regulatory mechanisms and critical targets of epigenetic modifications, including DNA methylation, histone modification, and RNA modification, in liver fibrotic diseases. The potential cooperation of different epigenetic modifications in promoting fibrogenesis was also highlighted. Finally, available agonists or inhibitors regulating these epigenetic mechanisms and their potential application in preventing liver fibrosis were discussed. In summary, elucidating specific druggable epigenetic targets and developing more selective and specific candidate medicines may represent a promising approach with bright prospects for the treatment of chronic liver diseases.

Abnormal metabolism in hepatic stellate cells: Pandora's box of MAFLD related hepatocellular carcinoma

Metabolic associated fatty liver disease (MAFLD) is a significant risk factor for the development of hepatocellular carcinoma (HCC). Hepatic stellate cells (HSCs), as key mediators in liver injury response, are believed to play a crucial role in the repair process of liver injury. However, in MAFLD patients, the normal metabolic and immunoregulatory mechanisms of HSCs become disrupted, leading to disturbances in the local microenvironment. Abnormally activated HSCs are heavily involved in the initiation and progression of HCC. The metabolic disorders and abnormal activation of HSCs not only initiate liver fibrosis but also contribute to carcinogenesis. In this review, we provide an overview of recent research progress on the relationship between the abnormal metabolism of HSCs and the local immune system in the liver, elucidating the mechanisms of immune imbalance caused by abnormally activated HSCs in MAFLD patients. Based on this understanding, we discuss the potential and challenges of metabolic-based and immunology-based mechanisms in the treatment of MAFLD-related HCC, with a specific focus on the role of HSCs in HCC progression and their potential as targets for anti-cancer therapy. This review aims to enhance researchers' understanding of the importance of HSCs in maintaining normal liver function and highlights the significance of HSCs in the progression of MAFLD-related HCC.

Long Noncoding RNA VLDLR-AS1 Levels in Serum Correlate with Combat-Related Chronic Mild Traumatic Brain Injury and Depression Symptoms in US Veterans

More than 75% of traumatic brain injuries (TBIs) are mild (mTBI) and military service members often experience repeated combat-related mTBI. The chronic comorbidities concomitant with repetitive mTBI (rmTBI) include depression, post-traumatic stress disorder or neurological dysfunction. This study sought to determine a long noncoding RNA (lncRNA) expression signature in serum samples that correlated with rmTBI years after the incidences. Serum samples were obtained from Long-Term Impact of Military-Relevant Brain-Injury Consortium Chronic Effects of Neurotrauma Consortium (LIMBIC CENC) repository, from participants unexposed to TBI or who had rmTBI. Four lncRNAs were identified as consistently present in all samples, as detected via droplet digital PCR and packaged in exosomes enriched for CNS origin. The results, using qPCR, demonstrated that the lncRNA VLDLR-AS1 levels were significantly lower among individuals with rmTBI compared to those with no lifetime TBI. ROC analysis determined an AUC of 0.74 (95% CI: 0.6124 to 0.8741; p = 0.0012). The optimal cutoff for VLDLR-AS1 was ≤153.8 ng. A secondary analysis of clinical data from LIMBIC CENC was conducted to evaluate the psychological symptom burden, and the results show that lncRNAs VLDLR-AS1 and MALAT1 are correlated with symptoms of depression. In conclusion, lncRNA VLDLR-AS1 may serve as a blood biomarker for identifying chronic rmTBI and depression in patients.

Transcriptomic evaluation of N6-methyladenosine modification can be used to identify differentially gene and immune-related biological processes in TX mice with liver fibrosis

BACKGROUND

N6-methyladenosine (m6A) modification controls the stability, splicing, and translation of mRNA, which is important in the development of illnesses. Wilson's disease (WD) is an autosomal recessive liver copper metabolic disorder that causes liver fibrosis. The role of m6A methylation in WD-induced liver fibrosis development is still unclear. Thus, the goal of this study was to examine the scope of m6A methylation and further explore the potential targets related to WD-induced liver fibrosis.

RESULTS

A total of 1930 significantly different m6A peaks were found on 1737 mRNAs, of which 993 were hypermethylated and 744 were hypomethylated when comparing normal and WD-induced liver fibrosis mice (n = 3). In parallel, 1261 differentially expressed mRNAs, comprising 557 upregulated and 704 downregulated mRNAs, were found. Overall, 114 mRNAs with significant changes in m6A levels and RNA expression were identified via joint analysis. Then, through PPI network construction and functional enrichment analysis, 12 hub genes were identified, these genes were mainly enriched in the inflammatory response and immunomodulation, and they are associated with immune cell infiltration.

CONCLUSIONS

The significant difference in the amount of mRNA m6A modifications indicates that m6A modification is involved in the progression of WD-induced liver fibrosis, and theidentified hub genes are involved in inflammation and immune infiltration. These results may provide insights for subsequent studies on potential regulatory mechanisms.

HCC-Related lncRNAs: Roles and Mechanisms

Hepatocellular carcinoma (HCC) presents a significant global health threat, particularly in regions endemic to hepatitis B and C viruses, and because of the ongoing pandemic of obesity causing metabolic-dysfunction-related fatty liver disease (MAFLD), a precursor to HCC. The molecular intricacies of HCC, genetic and epigenetic alterations, and dysregulated signaling pathways facilitate personalized treatment strategies based on molecular profiling. Epigenetic regulation, encompassing DNA methyltion, histone modifications, and noncoding RNAs, functions as a critical layer influencing HCC development. Long noncoding RNAs (lncRNAs) are spotlighted for their diverse roles in gene regulation and their potential as diagnostic and therapeutic tools in cancer. In this review, we explore the pivotal role of lncRNAs in HCC, including MAFLD and viral hepatitis, the most prevalent risk factors for hepatocarcinogenesis. The dysregulation of lncRNAs is implicated in HCC progression by modulating chromatin regulation and transcription, sponging miRNAs, and influencing structural functions. The ongoing studies on lncRNAs contribute to a deeper comprehension of HCC pathogenesis and offer promising routes for precision medicine, highlighting the utility of lncRNAs as early biomarkers, prognostic indicators, and therapeutic targets.

Expression patterns and functional analysis of porcine lnc-34015

Long noncoding RNAs (lncRNAs) play important roles in immune regulation in humans and animals. The lnc-34015 was discovered to be critical for the development of muscles, based on the muscle transcriptome of pigs; however, the underlying molecular mechanism requires better understanding. Here, the sequence characteristics of lnc-34015 were analyzed and a competitive endogenous RNA regulatory network of lncRNA was predicted. The developmental expression trend and tissue expression profiles of lnc-34015 were investigated using quantitative polymerase chain reaction. The lnc-34015 sequence is overlapped with introns 11 and 12 of CWF19L1, while CWF19L1, PKD2L1, and CHUK were identified as cis-regulatory genes of lnc-34015. Bioinformatics analyses revealed that lnc-34015 binds to 15 microRNAs (miRNAs), including miR-3646, miR-377-3p, and miR-190b-3p, to regulate downstream gene expression. GO and KEGG enrichment results show that lnc-34015 was mainly involved in cell proliferation, stress response, transcriptional regulation, and alternative splicing. The expression trend of lnc-34015 in muscle was similar to that of target genes and opposite to that of miRNAs. The expression of lnc-34015 was significantly higher in the porcine small intestine and IPEC-J2 cells. Our findings suggest that lnc-34015 regulates CHUK, ZBTB20, and XIAP gene expression by competing with endogenous RNAs to regulate porcine inflammatory responses.

Progress on traditional Chinese medicine in improving hepatic fibrosis through inhibiting oxidative stress

Hepatic fibrosis is a common pathological process that occurs in the development of various chronic liver diseases into cirrhosis and liver cancer, characterized by excessive deposition of the extracellular matrix. In the past, hepatic fibrosis was thought to be a static and irreversible pathological process. In recent years, with the rapid development of molecular biology and the continuous in-depth study of the liver at the microscopic level, more and more evidence has shown that hepatic fibrosis is a dynamic and reversible process. Therefore, it is particularly important to find an effective, simple, and inexpensive method for its prevention and treatment. Traditional Chinese medicine (TCM) occupies an important position in the treatment of hepatic fibrosis due to its advantages of low adverse reactions, low cost, and multi-target effectiveness. A large number of research results have shown that TCM monomers, single herbal extracts, and TCM formulas play important roles in the prevention and treatment of hepatic fibrosis. Oxidative stress (OS) is one of the key factors in the occurrence and development of hepatic fibrosis. Therefore, this article reviews the progress in the understanding of the mechanisms of TCM monomers, single herbal extracts, and TCM formulas in preventing and treating hepatic fibrosis by inhibiting OS in recent years, in order to provide a reference and basis for drug therapy of hepatic fibrosis.

Long non-coding RNA H19 enhances the pro-apoptotic activity of ITF2357 (a histone deacetylase inhibitor) in colorectal cancer cells

Introduction: Long non-coding RNA H19 (lncH19) is highly expressed in colorectal cancer (CRC) and plays critical roles in tumor development, proliferation, metastasis, and drug resistance. Indeed, the expression of lncH19 usually affects the outcomes of chemo-, endocrine, and targeted therapies. ITF2357 (givinostat) is a histone deacetylase inhibitor (HDACi) that revealed a significant anti-tumor action by inducing apoptosis in different tumor models, including leukemia, melanoma, and glioblastoma. However, no data are present in the literature regarding the use of this compound for CRC treatment. Here, we investigate the role of lncH19 in ITF2357-induced apoptosis in CRC cells. Methods: The HCT-116 CRC cell line was stably silenced for H19 to investigate the role of this lncRNA in ITF2357-induced cell death. Cell viability assays and flow cytometric analyses were performed to assess the anti-proliferative and pro-apoptotic effects of ITF2357 in CRC cell lines that are silenced or not for lncH19. RT-PCR and Western blot were used to study the effects of ITF2357 on autophagy and apoptosis markers. Finally, bioinformatics analyses were used to identify miRNAs targeting pro-apoptotic factors that can be sponged by lncH19. Results: ITF2357 increased the expression levels of H19 and reduced HCT-116 cell viability, inducing apoptosis, as demonstrated by the increase in annexin-V positivity, caspase 3 cleavage, and poly (ADP-ribose) polymerase (PARP-1) degradation. Interestingly, the apoptotic effect of ITF2357 was much less evident in lncH19-silenced cells. We showed that lncH19 plays a functional role in the pro-apoptotic activity of the drug by stabilizing TP53 and its transcriptional targets, NOXA and PUMA. ITF2357 also induced autophagy in CRC cells, which was interpreted as a pro-survival response not correlated with lncH19 expression. Furthermore, ITF2357 induced apoptosis in 5-fluorouracil-resistant HCT-116 cells that express high levels of lncH19. Conclusion: This study shows that lncH19 expression contributes to ITF2357-induced apoptosis by stabilizing TP53. Overall, we suggest that lncH19 expression may be exploited to favor HDACi-induced cell death and overcome 5-fluorouracil chemoresistance.

TUG1 protects against ferroptosis of hepatic stellate cells by upregulating PDK4-mediated glycolysis

The induction of ferroptosis in hepatic stellate cells (HSCs) has shown promise in reversing liver fibrosis. And ferroptosis has been confirmed to be associated with glycolysis. The objective of this study is to determine whether ferroptosis inhibition in HSCs, induced by elevation of recombinant pyruvate dehydrogenase kinase isozyme 4 (PDK4)-mediated glycolysis, could mediate the pathogenesis of liver fibrosis. Liver fibrosis was induced using CCl4, the level of which was assessed through histochemical staining. Lentivirus was used to modulate the expression of specific genes. And underlying mechanisms were explored using primary HSCs extracted from normal mice. The results confirmed that Taurine up-regulated gene 1 (TUG1) expression was upregulated in liver fibrotic tissues and HSCs, showing a positive correlation with fibrosis. In addition, TUG1 attenuated ferroptosis in HSCs by promoting PDK4-mediated glycolysis, thereby promoting the progression of liver fibrosis. Moreover, TUG1 was observed to impact HSCs activation, exacerbating liver fibrosis to some extent. In conclusion, our study revealed that TUG1 expression was elevated in mouse models of liver fibrosis and activated HSCs, which inhibited ferroptosis in HSCs through PDK4-mediated glycolysis. This finding may open up a new therapeutic strategy for liver fibrosis.

Screening and identification of potential biomarkers for pancreatic cancer: An integrated bioinformatics analysis

Pancreatic cancer is one of the highly invasive and the seventh most common cause of death among cancers worldwide. To identify essential genes and the involved mechanisms in pancreatic cancer, we used bioinformatics analysis to identify potential biomarkers for pancreatic cancer management. Gene expression profiles of pancreatic cancer patients and normal tissues were screened and downloaded from The Cancer Genome Atlas (TCGA) bioinformatics database. The Differentially expressed genes (DEGs) were identified among gene expression signatures of normal and pancreatic cancer, using R software. Then, enrichment analysis of the DEGs, including Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, was performed by an interactive and collaborative HTML5 gene list enrichment analysis tool (enrichr) and ToppGene. The protein-protein interaction (PPI) network was also constructed using the Search Tool for the Retrieval of Interacting Genes (STRING) database and ToppGenet web based tool followed by identifying hub genes of the top 100 DEGs in pancreatic cancer using Cytoscape software. Over 2000 DEGs with variable log2 fold (LFC) were identified among 34,706 genes. Principal component analysis showed that the top 20 DEGs, including H1-4, H1-5, H4C3, H4C2, RN7SL2, RN7SL3, RN7SL4P, RN7SKP80, SCARNA12, SCARNA10, SCARNA5, SCARNA7, SCARNA6, SCARNA21, SCARNA9, SCARNA13, SNORA73B, SNORA53, SNORA54 might distinguish pancreatic cancer from normal tissue. GO analysis showed that the top DEGs have more enriched in the negative regulation of gene silencing, negative regulation of chromatin organization, negative regulation of chromatin silencing, nucleosome positioning, regulation of chromatin silencing, and nucleosomal DNA binding. KEGG analysis identified an association between pancreatic cancer and systemic lupus erythematosus, alcoholism, neutrophil extracellular trap formation, and viral carcinogenesis. In PPI network analysis, we found that the different types of histone-encoding genes are involved as hub genes in the carcinogenesis of pancreatic cancer. In conclusion, our bioinformatics analysis identified genes that were significantly related to the prognosis of pancreatic cancer patients. These genes and pathways could serve as new potential prognostic markers and be used to develop treatments for pancreatic cancer patients.

Long non-coding RNA GNAS-AS1 knockdown inhibits proliferation and epithelial-mesenchymal transition of lung adenocarcinoma cells via the microRNA-433-3p/Rab3A axis

The goal of this study was to demonstrate the functions and specific mechanism of long non-coding RNA (lncRNA) GNAS-AS1 in lung adenocarcinoma. Levels of lncRNA GNAS-AS1, microRNA (miR)-433-3p, and Rab3A were assessed by quantitative real-time PCR (qRT-PCR). The target-binding sites of lncRNA GNAS-AS1, miR-433-3p, and Rab3A were predicted and confirmed by bioinformatics tool (StarBase) and a dual-luciferase reporter system. Cell proliferation and apoptosis were checked using MTT and flow cytometry, respectively. Additionally, the levels of apoptosis-related and epithelial-mesenchymal transition (EMT)-associated genes in A549 cells were analyzed by qRT-PCR and western blot. We found that lncRNA GNAS-AS1 was upregulated, miR-433-3p was low-expressed, and Rab3A was overexpressed in lung adenocarcinoma tissues and cell lines. LncRNA GNAS-AS1 interacted with miR-433-3p and negatively regulated miR-433-3p levels. Rab3A was a direct target of miR-433-3p. Downregulation of lncRNA GNAS-AS1 remarkably suppressed cell proliferation, promoted cell apoptosis, decreased B-cell lymphoma-2 (Bcl-2) expression, enhanced the Bcl-2-Associated X (Bax) level, promoted E-cadherin expression, and reduced N-cadherin and Rab3A levels. However, the miR-433-3p inhibitor reversed all these findings. Similarly, the inhibitory effects of miR-433-3p mimic on A549 cells were reversed by the Rab3A-plasmid. In conclusion, lncRNA GNAS-AS1 downregulation suppressed lung adenocarcinoma cell proliferation and EMT through the miR-433-3p/Rab3A axis.

Transcriptional regulation of Glis2 in hepatic fibrosis

The role of Gli-similar 2 (Glis2) in hepatic fibrosis (HF) is controversial. In this study, we focused on the functional and molecular mechanisms involved in the Glis2-mediated activation of hepatic stellate cells (HSCs)-a milestone event leading to HF. The expression levels of Glis2 mRNA and protein were significantly decreased in the liver tissues of patients with severe HF and in mouse fibrotic liver tissues as well as HSCs activated by TGFβ1. Functional studies indicated that upregulated Glis2 significantly inhibited HSC activation and alleviated BDL-induced HF in mice. Downregulation of Glis2 was found to correlate significantly with DNA methylation of the Glis2 promoter mediated by methyltransferase 1 (DNMT1), which restricted the binding of hepatic nuclear factor 1-α (HNF1-α), a liver-specific transcription factor, to Glis2 promoters. In addition, the enrichment of DNMT1 in the Glis2 promoter region was mediated by metastasis-associated lung adenocarcinoma transcriptor-1 (MALAT1) lncRNA, leading to transcriptional silencing of Glis2 and activation of HSCs. In conclusion, our findings reveal that the upregulation of Glis2 can maintain the resting state of HSCs. The decreased expression of Glis2 under pathological conditions may lead to the occurrence and development of HF with the expression silencing of DNA methylation mediated by MALAT1 and DNMT1.

Dysregulation of murine long noncoding single-cell transcriptome in nonalcoholic steatohepatitis and liver fibrosis

LncRNAs comprise a heterogeneous class of RNA-encoding genes typified by low expression, nuclear enrichment, high tissue-specificity, and functional diversity, but the vast majority remain uncharacterized. Here, we assembled the mouse liver noncoding transcriptome from >2000 bulk RNA-seq samples and discovered 48,261 liver-expressed lncRNAs, a majority novel. Using these lncRNAs as a single-cell transcriptomic reference set, we elucidated lncRNA dysregulation in mouse models of high fat diet-induced nonalcoholic steatohepatitis and carbon tetrachloride-induced liver fibrosis. Trajectory inference analysis revealed lncRNA zonation patterns across the liver lobule in each major liver cell population. Perturbations in lncRNA expression and zonation were common in several disease-associated liver cell types, including nonalcoholic steatohepatitis-associated macrophages, a hallmark of fatty liver disease progression, and collagen-producing myofibroblasts, a central feature of liver fibrosis. Single-cell-based gene regulatory network analysis using bigSCale2 linked individual lncRNAs to specific biological pathways, and network-essential regulatory lncRNAs with disease-associated functions were identified by their high network centrality metrics. For a subset of these lncRNAs, promoter sequences of the network-defined lncRNA target genes were significantly enriched for lncRNA triplex formation, providing independent mechanistic support for the lncRNA-target gene linkages predicted by the gene regulatory networks. These findings elucidate liver lncRNA cell-type specificities, spatial zonation patterns, associated regulatory networks, and temporal patterns of dysregulation during hepatic disease progression. A subset of the liver disease-associated regulatory lncRNAs identified have human orthologs and are promising candidates for biomarkers and therapeutic targets.

Knocking Down Gm16685 Decreases Liver Granuloma in Murine Schistosomiasis Japonica

Long noncoding RNAs (lncRNAs) can regulate key genes and pathways in liver disease development. Moreover, macrophages are speculated to play an important role in regulating granulomatous inflammation during schistosomiasis. However, the role of lncRNAs in the formation of liver granulomas by influencing the polarization of macrophages in Schistosoma japonicum infection is unclear. Our study aimed to determine whether lncRNAs can play a role in S. japonicum-induced hepatic egg granulomas and elucidate their effect on macrophages. We established S. japonicum infection models and screened the target lncRNA Gm16685 highly expressed in schistosomiasis mice using high-throughput sequencing. Hematoxylin and eosin staining revealed that the knockdown of Gm16685 reduced the area of egg granulomas. Moreover, M1 macrophage factor genes were significantly downregulated in Gm16685 knockdown livers. Meanwhile, M2 macrophage factor genes were significantly upregulated, which was consistent with the protein detection results. Hepatocytes, hepatic stellate cells, and macrophages were isolated from mouse models infected with S. japonicum, with Gm16685 being significantly upregulated in macrophages. Moreover, the knockdown of Gm16685 in RAW264.7 cells revealed similar results to in liver tissue. RNA fluorescence in situ hybridization (FISH) and nucleocytoplasmic separation experiments revealed that Gm16685 was predominantly localized in the cytoplasm of cells. We found that miR-205-5p was upregulated after Gm16685 was knocked down. After overexpression of miR-205-5p, the expression of Gm16685 and inflammatory factors was significantly downregulated. These results indicate that Gm16685 can participate in the pathogenesis of hepatic disease in schistosomiasis and promote M1 macrophage polarization by regulating miR-205-5p. Thus, our study may provide a new target for schistosomiasis japonica treatment.

Role of noncoding RNAs in liver fibrosis

Liver fibrosis is a wound-healing response following chronic liver injury caused by hepatitis virus infection, obesity, or excessive alcohol. It is a dynamic and reversible process characterized by the activation of hepatic stellate cells and excess accumulation of extracellular matrix. Advanced fibrosis could lead to cirrhosis and even liver cancer, which has become a significant health burden worldwide. Many studies have revealed that noncoding RNAs (ncRNAs), including microRNAs, long noncoding RNAs and circular RNAs, are involved in the pathogenesis and development of liver fibrosis by regulating signaling pathways including transforming growth factor-β pathway, phosphatidylinositol 3-kinase/protein kinase B pathway, and Wnt/β-catenin pathway. NcRNAs in serum or exosomes have been reported to tentatively applied in the diagnosis and staging of liver fibrosis and combined with elastography to improve the accuracy of diagnosis. NcRNAs mimics, ncRNAs in mesenchymal stem cell-derived exosomes, and lipid nanoparticles-encapsulated ncRNAs have become promising therapeutic approaches for the treatment of liver fibrosis. In this review, we update the latest knowledge on ncRNAs in the pathogenesis and progression of liver fibrosis, and discuss the potentials and challenges to use these ncRNAs for diagnosis, staging and treatment of liver fibrosis. All these will help us to develop a comprehensive understanding of the role of ncRNAs in liver fibrosis.

PBMCs gene expression signature of advanced cirrhosis with high risk for clinically significant portal hypertension in HIV/HCV coinfected patients: A cross-control study

BACKGROUND

Patients with advanced cirrhosis are at high risk of developing clinically significant portal hypertension (CSPH). We analyzed the gene expression profile of peripheral blood mononuclear cells (PBMCs) from HIV/HCV coinfected patients to identify a gene expression signature of advanced cirrhosis with high risk for CSPH.

METHODS

We conducted a cross-sectional study on 68 patients. Liver stiffness measurement (LSM) was used to stratify patients into < 12.5 kPa (no cirrhosis, n = 19), 12.5 - 24.9 kPa (cirrhosis, n = 20), and ≥ 25 kPa (advanced cirrhosis with high risk for CSPH, n = 29). Besides, we further evaluated LSM < 25 kPa (n = 39) vs. ≥ 25 kPa (n = 29). Total RNA was extracted from PBMCs, and poly(A) RNA sequencing was performed. Two significant differentially expressed (SDE) transcripts were validated by quantitative PCR in a different cohort (n = 46).

RESULTS

We found 60 SDE transcripts between patients with LSM < 12.5 kPa and ≥ 25 kPa. Partial least squares discriminant analysis showed that those 60 SDE transcripts collectively discriminated LSM ≥ 25 kPa, with an area under the receiver operating characteristic curve (AUROC) of 0.84. Eight genes had an AUROC ≥ 0.75 for LSM ≥ 25 kPa: five were positively associated with LSM values (SCAMP1, ABHD17B, GPR146, GTF2A1, and TMEM64), while three were inversely associated (ZFHX2-AS1, MDK, and STAG3L2). We validated the two SDE transcripts with the highest discrimination capacity in a different cohort, finding significant differences between < 25 kPa and ≥ 25 kPa (MDK (p = 0.006) and STAG3L2 (p = 0.021)).

CONCLUSIONS

A gene expression signature of 60 transcripts was associated with advanced cirrhosis with high risk for CSPH in HIV/HCV coinfected patients.

A Study on the Expression of Messenger RNAs and Long Noncoding RNA in Keloid Fibroblasts Based on Gene Expression Omnibus Microarray Data Mining

OBJECTIVE

The purpose of this study was to find the coding RNA [messenger RNA (mRNA)] and long noncoding RNA (lncRNA) expressed in keloid through the analysis of Gene Expression Omnibus microarray chip of keloid fibroblasts.

MATERIALS AND METHODS

Gene Expression Omnibus database GSE7890 database was downloaded with selection of keloids and normal scar group data. The data were analyzed by R language combined with online database. The log2FC>1, P value <0.01 was chosen as screening criteria, and the differentially expressed mRNAs were screened for GO and KEGG function analysis.

RESULTS

One hundred fifty-five mRNA expression in the keloid group was significantly different from that in the normal group, including 31 groups with upregulated mRNA expression and 124 groups with down-regulated mRNA expression. Meanwhile, 8 lncRNAs were changed in the keloid group, including 3 upregulated (Rp11-420a23.1, Rp11-522b15.3, and Rp11-706j10.1) and 5 down-regulated (LINC00511, LINC00327, Hoxb-as3, Rp11-385n17.1, and Rp3-428l16.2). Quantitative polymerase chain reaction analysis of DElncRNAs in keloid fibroblasts showed that the expression of all DElncRNAs except for RP11-385N17.1 was increased in the keloid group compared with the control group. Moreover, the differences in LINC00511 and RP11-706J10.1 were statistically significant.

CONCLUSION

The noncoding RNA information of Gene Expression Omnibus chip data can be deeply mined through bioinformatics, and the potential epigenomic mechanism affecting keloid formation can be found from the existing database.

Could Long Non-Coding RNA MEG3 and PTENP1 Interact with miR-21 in the Pathogenesis of Non-Alcoholic Fatty Liver Disease?

NAFLD is the most common cause of chronic liver disease worldwide. The miRNAs and lncRNAs are important endogenous ncRNAs families that can regulate molecular mechanisms. The aim of this study was to analyze the miRNA and lncRNA expression profiles in serum samples of NAFLD patients with different types of hepatosteatosis compared to healthy controls by the qPCR method. A total of180 NAFLD patients and 60 healthy controls were included. miRCURY LNA miRNA miRNome PCR human panel I + II kit and LncProfiler qPCR Array Kit were used to detect miRNA and lncRNA expression, respectively. DIANA miRPath and DIANA-lncBase web servers were used for interaction analysis. As a result, 75 miRNA and 24 lncRNA expression changes were determined. For miRNAs and lncRNAs, 30 and 5 were downregulated and 45 and 19 were upregulated, respectively. hsa-miR-21 was upregulated 2-fold whereas miR-197 was downregulated 0.25-fold. Among lncRNAs, NEAT1 was upregulated 2.9-fold while lncRNA MEG3 was downregulated 0.41-fold. A weak correlation was found between hsa-miR-122 and lncRNA MALAT1. As a conclusion, it is clear that lncRNA-miRNA interaction is involved in the molecular mechanisms of the emergence of NAFLD. The lncRNAs MEG3 and PTENP1 interacted with hsa-miR-21. It was thought that this interaction should be investigated as a biomarker for the development of NAFLD.

Inhibition of long noncoding RNA Gm41724 alleviates pressure overload-induced cardiac fibrosis by regulating lamina-associated polypeptide 2α

Cardiac fibrosis is a pathological process underlying myocardial remodeling and is characterized by excessive deposition of the myocardial extracellular matrix. Long noncoding RNAs (lncRNAs) have emerged as critical regulators of various biological processes. In this study, we investigated the role of a novel lncRNA, Gm41724, in cardiac fibrosis induced by pressure overload. High-throughput whole transcriptome sequencing analysis was performed to detect differentially expressed lncRNAs in cardiac fibroblasts (CFs) with or without TGF-β1 treatment. Differential expression analysis and gene set enrichment analysis identified Gm41724 as a potential molecule targeting fibrosis. Gm41724 positively regulated the activation of CFs induced by TGF-β1 and pressure overload. Knocking down Gm41724 could inhibit the differentiation of CFs into myofibroblasts and alleviate cardiac fibrosis induced by pressure overload. Mechanistically, comprehensive identification of RNA-binding proteins by mass spectrometry (CHIRP-MS) and RNA immunoprecipitation (RIP) assay combined with other methods of molecular biological revealed the important role of Gm41724 binding to lamina-associated polypeptide 2α (lap2α) for the activation of CFs. Further mechanistic studies indicated that the regulator of G protein signaling 4 (Rgs4), as the downstream effector of Gm41724/lap2α, regulated CFs activation. Our results implicated the involvement of Gm41724 in cardiac fibrosis induced by pressure overload and it is expected to be a promising target for anti-fibrotic therapy.

CXCL12/CXCR4: An amazing challenge and opportunity in the fight against fibrosis

Fibrosis is a pathological process caused by abnormal wound healing response, which often leads to excessive deposition of extracellular matrix, distortion of organ architecture, and loss of organ function. Aging is an important risk factor for the development of organ fibrosis. C-X-C receptor 4 (CXCR4) is the predominant chemokine receptor on fibrocytes, C-X-C motif ligand 12 (CXCL12) is the only ligand of CXCR4. Accumulated evidence have confirmed that CXCL12/CXCR4 can be involved in multiple pathological mechanisms in fibrosis, such as inflammation, immunity, epithelial-mesenchymal transition, and angiogenesis. In addition, CXCL12/CXCR4 have also been shown to improve fibrosis levels in many organs including the heart, liver, lung and kidney; thus, they are promising targets for anti-fibrotic therapy. Notably, inhibitors of CXCL12 or CXCR4 also play an important role in various fibrosis-related diseases. In summary, this review systematically summarizes the role of CXCL12/CXCR4 in fibrosis, and this information is of great significance for understanding CXCL12/CXCR4. This will also contribute to the design of further studies related to CXCL12/CXCR4 and fibrosis, and shed light on potential therapies for fibrosis.

Construction and function analysis of the LncRNA-miRNA-mRNA competing endogenous RNA network in autoimmune hepatitis

AIMS

To construct the lncRNA-miRNA-mRNA competing endogenous RNA (ceRNA) network based on our microarray chip data for providing new insights into the pathogenesis of autoimmune hepatitis.

METHODS

The ceRNA pairs were obtained by calculating the co-expression relationships among the differentially expressed lncRNAs (DELs), differentially expressed microRNAs (DEMis), and differentially expressed mRNAs (DEMs) with Pearson correlation analysis and hypergeometric distribution. The data of the differentially expressed genes were obtained from our previous studies in the concanavalin A-induced AIH mouse model. The biological functions of the ceRNA network were revealed by carrying out the GO and KEGG enrichment analysis. The expression of some differentially expressed genes constructed in the ceRNA pair was validated, and the correlation to liver injury was analyzed.

RESULTS

The mRNAs constructed in the ceRNA network were most significantly annotated in the GO terms of "inflammatory response" and enriched in "Cytokine-cytokine receptor interaction" and "MAPK signaling pathway". The differences in the expression of Gm38975, mmu-miR-125a-3p, and Map3k13 between the model group and control group were significant, and the expression of these genes at a transcriptional level was positively or negatively correlated to the activity of ALT and AST as well as the amount of MDA and NO.

CONCLUSION

Our work is the first in its kind to predict and illustrate the comprehensive lncRNA-miRNA-mRNA ceRNA network associated with the etiopathogenesis of AIH. This study indicates to lay the foundation for revealing the potential roles of ceRNAs in the occurrence of AIH and provide novel treatment targets for this disease.

The Role of Stem Cell Factor, Epidermal Growth Factor and Angiopoietin-2 in HBV, HCV, HCC and NAFLD

Growth factors play a significant role in the immunopathogenesis of liver diseases, especially in liver fibrosis and cirrhosis. They can also play a role in liver regeneration and tissue repair. The regenerative capacity of the liver has been well established. Molecular mechanisms leading to regeneration involve a complex network of diverse molecules. Chronic liver injury leads to the dysregulation of regenerative mechanisms in the liver that, in addition to molecular oncogenesis, lead to uncontrolled cell proliferation and development of hepatocellular carcinoma (HCC). Stem cell factor (SCF), epidermal growth factor (EGF) and Angiopietin-2 (Ang-2) have been shown to be extremely important in the pathogenesis of liver diseases, and given their role in hepatitis B (HBV) or C virus (HCV), HCC and nonalcoholic fatty liver disease (NAFLD), they seem to be potential targets for future research into antifibrotic drugs. The role of SCF receptor c-kit in the liver is debatable, as it has impact on both liver regeneration and liver disease. EGF is a potential indicator of the survival of patients with HCC and can be a biomarker and therapeutic target structure in HCC. Further research is needed to investigate the potential role of Ang-2 for NAFLD associated with liver damage as a non-invasive circulating biomarker.

Salvianolic acid B suppresses hepatic stellate cell activation and liver fibrosis by inhibiting the NF-κB signaling pathway via miR-6499-3p/LncRNA-ROR

BACKGROUND

Long non-coding RNA (LncRNAs) have been reported to play an important role in liver fibrosis and are closely associated with hepatic stellate cell (HSC) activation. We previously found that salvianolic acid B (Sal B) improves liver fibrosis by regulating the NF-κB signaling pathway. However, whether the LncRNA, regulator of reprogramming (LncRNA-ROR) plays a role in Sal B-mediated anti-fibrosis effects via the NF-κB signaling pathway remain unclear.

PURPOSE

This study aimed to evaluate the effects of Sal B on HSC activation and liver fibrosis and investigate its mechanism from the perspective of LncRNA-ROR-mediated NF-κB signaling pathways.

METHODS

LX-2 and T6 cell lines were cultured. Animal models of liver fibrosis were established using CCl4 in male BALB/c mice. Primary HSCs were isolated from mice and cultured. Serum biochemical and liver histological analyses were performed to evaluate the effects of Sal B on liver fibrosis. The index of HSC activation and the expression of LncRNA-ROR, microRNAs (miRNAs), and inflammatory factors were determined by quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) or immunofluorescence staining. Cell proliferation was measured by a Cell Counting Kit-8 (CCK-8). NF-κB signaling-associated protein levels were assessed using western blotting or immunofluorescence staining. A luciferase reporter assay was used to detect transcription activity.

RESULTS

In this study, a lower level of LncRNA-ROR was found during Sal B attenuating HSC activation in HSCs. Mechanistically, Sal B impeded the NF-κB signaling pathway to inhibit HSC proliferation and activation by downregulating LncRNA-ROR. Additionally, Sal B upregulated miR-6499-3p to target LncRNA-ROR for degradation. Functionally, Sal B treatment ameliorated CCl4-induced liver fibrosis in mice by inhibiting HSC activation.

CONCLUSION

Sal B suppresses HSC activation and liver fibrosis via regulation of miR-6499-3p/LncRNA-ROR-mediated NF-κB signaling pathway. These results reveal a new molecular mechanism of Sal B on liver fibrosis from the insight of LncRNAs.

Protective Effect and Mechanism of Placenta Extract on Liver

The placenta contains multiple biologically active substances, which exert antioxidation, anti-inflammatory, immunomodulatory, and delayed aging effects. Its extract can improve hepatic morphology and function: on the one hand, it can reduce liver interstitial collagen deposition, lipogenesis, and inflammatory cell infiltration and improve fibrosis; on the other hand, it can prevent hepatocellular degeneration by scavenging reactive oxygen species (ROS) and inhibiting inflammatory cytokine production, further improve hepatocyte apoptosis and necrosis, and promote hepatocyte regeneration, making it a promising liver-protective agent. Current research on placenta extract (PE) mainly focuses on treating a specific type of liver injury, and there are no systematic reports. Therefore, this review comprehensively summarizes the treatment reports of PE on liver injury and analyzes its mechanism of action.

Recent insights into the microRNA and long non-coding RNA-mediated regulation of stem cell populations

Stem cells are undifferentiated cells that have multi-lineage differentiation. The transition from self-renewal to differentiation requires rapid and extensive gene expression alterations. Since different stem cells exhibit diverse non-coding RNAs (ncRNAs) expression profiles, the critical roles of ncRNAs in stem cell reprogramming, pluripotency maintenance, and differentiation have been widely investigated over the past few years. Hence, in this current review, the two main categories of ncRNAs, microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), are discussed. While the primary way by which miRNAs restrict mRNA transcription is through miRNA-mRNA interaction, lncRNAs have a wide range of effects on mRNA functioning, including interactions with miRNAs. Both of these ncRNAs participate in the post-transcriptional regulation of crucial biological mechanisms, such as cell cycle regulation, apoptosis, aging, and cell fate decisions. These findings shed light on a previously unknown aspect of gene regulation in stem cell fate determination and behavior. Overall, we summarized the key roles of miRNAs (including exosomal miRNAs) and lncRNAs in the regulation of stem cell populations, such as cardiac, hematopoietic, mesenchymal, neural, and spermatogonial, as well ncRNAs' influence on malignancy through modulating cancer stem cells, which might significantly contribute to clinical stem cell therapy and in regenerative medicine.

The activation of M 3 muscarinic receptor reverses liver injuryvia the Sp1/lncRNA Gm2199/miR-212 axis

Muscarinic acetylcholine receptors (MRs) play important roles in the regulation of hepatic fibrosis and the receptor agonists and antagonists can affect hepatocyte proliferation. However, little is known about the impact of M ₃R subtypes and associated signaling pathways on liver injury. The aim of this study is to explore the function and mechanism of M ₃R in the regulation of liver injury. We evaluate liver injury and detect the changes in related indexes, including alanine aminotransferase (ALT), aspartate aminotransferase (AST), hydroxyproline (HYP), and transforming growth factor-β1 (TGF-β1), after administration of an M ₃R agonist. Western blot analysis and qRT-PCR show that the transcription factor Sp1 and long noncoding RNA (lncRNA) Gm2199 are also changed significantly. Rescue assay is performed to further confirm that M ₃R contributes to the progression of hepatocyte proliferation through regulating Sp1 and Gm2199. The activated M ₃R can specifically regulate Gm2199 by inhibiting the expression of Sp1. Meanwhile, Gm2199 directly regulates miR-212, and ERK is a potential target of miR-212. Collectively, these findings define a novel mechanism for activating M ₃R to reverse liver injury, which affects hepatocyte proliferation through the Sp1/Gm 2199/miR-212/ERK axis.

Characterization of differentially expressed and lipid metabolism-related lncRNA-mRNA interaction networks during the growth of liver tissue through rabbit models

Background

Characterization the long non-coding RNAs (lncRNAs) and their regulated mRNAs involved in lipid metabolism during liver growth and development is of great value for discovering new genomic biomarkers and therapeutic targets for fatty liver and metabolic syndrome.

Materials and methods

Liver samples from sixteen rabbit models during the four growth stages (birth, weaning, sexual maturity, and somatic maturity) were used for RNA-seq and subsequent bioinformatics analyses. Differentially expressed (DE) lncRNAs and mRNAs were screened, and the cis/trans-regulation target mRNAs of DE lncRNAs were predicted. Then the function enrichment analyses of target mRNAs were performed through Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, respectively. The target protein interaction (PPI) and lncRNA-mRNA co-expression networks were constructed using string version 11.0 platform and R Stats. Finally, six lncRNAs and six mRNAs were verified taking RT-qPCR.

Results

Liver Oil Red O detection found that the liver showed time-dependent accumulation of lipid droplets. 41,095 lncRNAs, 30,744 mRNAs, and amount to 3,384 DE lncRNAs and 2980 DE mRNAs were identified from 16 cDNA sequencing libraries during the growth of liver. 689 out of all DE lncRNAs corresponded to 440 DE mRNAs by cis-regulation and all DE mRNAs could be regulated by DE lncRNAs by trans-regulation. GO enrichment analysis showed significant enrichment of 892 GO terms, such as protein binding, cytosol, extracellular exsome, nucleoplasm, and oxidation-reduction process. Besides, 52 KEGG pathways were significantly enriched, including 11 pathways of lipid metabolism were found, like Arachidonic acid metabolism, PPAR signaling pathway and Biosynthesis of unsaturated fatty acids. After the low expression DE mRNAs and lncRNAs were excluded, we further obtained the 54 mRNAs were regulated by 249 lncRNAs. 351 interaction pairs were produced among 38 mRNAs and 215 lncRNAs through the co-expression analysis. The PPI network analysis found that 10 mRNAs such as 3β-Hydroxysteroid-Δ24 Reductase (DHCR24), lathosterol 5-desaturase (SC5D), and acetyl-CoA synthetase 2 (ACSS2) were highly interconnected hub protein-coding genes. Except for MSTRG.43041.1, the expression levels of the 11 genes by RT-qPCR were the similar trends to the RNA-seq results.

Conclusion

The study revealed lncRNA-mRNA interation networks that regulate lipid metabolism during liver growth, providing potential research targets for the prophylaxis and treatment of related diseases caused by liver lipid metabolism disorders.

The Transgene Expression of the Immature Form of the HCV Core Protein (C191) and the LncRNA MEG3 Increases Apoptosis in HepG2 Cells

Long non-coding RNAs (lncRNAs) are regulated in cancer cells, including lncRNA MEG3, which is downregulated in Hepatocellular Carcinoma (HCC). In addition, hepatitis C virus (HCV) core proteins are known to dysregulate important cellular pathways that are linked to HCC development. In this study, we were interested in evaluating the overexpression of lncRNA MEG3, either alone or in combination with two forms of HCV core protein (C173 and C191) in HepG2 cells. Cell viability was assessed by MTT assay. Transcripts' levels of key genes known to be regulated in HCC, such as p53, DNMT1, miRNA152, TGF-b, and BCL-2, were measured by qRT-PCR. Protein expression levels of caspase-3 and MKI67 were determined by immunocytochemistry and apoptosis assays. The co-expression of lncRNA MEG3 and C191 resulted in a marked increase and accumulation of dead cells and a reduction in cell viability. In addition, a marked increase in the expression of tumor suppressor genes (p53 and miRNA152), as well as a marked decrease in the expression of oncogenes (DNMT1, BCL2, and TGF-b), were detected. Moreover, apoptosis assay results revealed a significant increase in total apoptosis (early and late). Finally, immunocytochemistry results detected a significant increase in apoptotic marker caspase-3 and a decrease in tumor marker MKI67. In this study, transgene expression of C191 and lncRNA MEG3 showed induction in apoptosis in HepG2 cells greater than the expression of each one alone. These results suggest potential anticancer characteristics.

Long noncoding RNA GAS5 inhibits LX-2 cells activation by suppressing NF-κB signalling through regulation of the miR-433-3p/TLR10 axis

BACKGROUND

Liver fibrosis is a common disease that can lead to hepatic failure.

AIMS

Our aims were to reveal the role of GAS5 in the regulation of liver fibrosis.

METHODS

LX-2 human hepatic satellite cells (HSCs) were cultured and activated using TGF-β1 treatment. A CCK-8 assay was performed to assess cell viability. A luciferase assay was employed to monitor the interactions between miR-433-3p and GAS5 or toll-like receptor 10 (TLR10). Western blotting and real-time quantitative PCR (RT-qPCR) were applied to detect the expression levels of α-SMA, Col. I, PCNA-, MMP2-, MMP9-, TLR10-, and NF-κB-related molecules at the protein and RNA levels.

RESULTS

GAS5 and TLR10 were decreased while miR-433-3p was upregulated in TGF-β1-activated LX-2 cells. Upregulation of GAS5 or downregulation of miR-433-3p suppressed HSC activation, and luciferase assays indicated that miR-433-3p binds with GAS5 and the 3'-UTR of TLR10. MiR-433-3p upregulation and TLR10 downregulation rescued the impacts of GAS5 overexpression or miR-433-3p knockdown on LX-2 cells. Upregulation of GAS5 also suppressed the phosphorylation of NF-κB through the miR-433-3p/TLR10 axis.

CONCLUSION

LncRNA GAS5 exerts an inhibitory effect on HSC activation by suppressing NF-κB signalling through regulation of the miR-433-3p/TLR10 axis.

Bone marrow mesenchymal stem cells inhibit hepatic fibrosis via the AABR07028795.2/rno-miR-667-5p axis

Background

The mechanism of bone marrow mesenchymal stem cells (BMSCs) in treating hepatic fibrosis remains unclear.

Methods

TGF-β1-induced hepatic stellate cell (HSC)-T6 and CCl4-induced hepatic fibrosis rats were treated with BMSCs. HSC-T6 cell activity was determined using the cell counting kit-8 assay, and the histology change was evaluated using hematoxylin and eosin and Masson staining. The expression of fibrosis markers was determined using real-time quantitative PCR, Western blotting, and immunocytochemistry. RNA sequencing (RNA-seq) was used to screen the lncRNAs involved in the effect of BMSCs in fibrosis, and the function of fibrosis-associated lncRNA in fibrosis histology change and fibrosis marker expression was investigated. The potential miRNA target of lncRNA was predicted using R software. The interaction between lncRNA and miRNA was verified using luciferase report system and RNA immunoprecipitation (RIP) in 293T and HSC-T6 cells.

Results

BMSC attenuated TGF-β1-induced HSC-T6 activation and suppressed the expression of fibrosis-associated gene (MMP2, Collagen I, and αSMA) expression at the transcription and translation levels. BMSC treatment also improves hepatic fibrosis in rats with CCl4-induced fibrosis by decreasing the expression of fibrosis-associated genes and suppressing collagen deposition in the liver. RNA-seq revealed that AABR07028795.2 (lnc-BIHAA1) was downregulated in the TGF-β1-induced HSC-T6 after treatment with BMSCs as compared with those in TGF-β1-induced HSC-T6, and subsequently, functional analysis showed that lnc-BIHAA1 plays a beneficial role in suppressing hepatic fibrosis. Luciferase activity assay and RIP revealed that lnc-BIHAA1 interacted with the miRNA, rno-miR-667-5p, functioning as a fibrosis phenotype suppressor in TGF-β1-induced HSC-T6. Moreover, overexpression of rno-miR-667-5p significantly reverses the effect of lnc-BIHAA1 on HSC-T6.

Conclusions

BMSC treatment suppresses hepatic fibrosis by downregulating the lnc-BIHAA1/rno-miR-667-5p signaling pathway in HSCs. Our results provide a scientific basis for establishing BMSCs as a biological treatment method for liver fibrosis.

Interplay Between GH-regulated, Sex-biased Liver Transcriptome and Hepatic Zonation Revealed by Single-Nucleus RNA Sequencing

The zonation of liver metabolic processes is well-characterized; however, little is known about the cell type-specificity and zonation of sexually dimorphic gene expression or its growth hormone (GH)-dependent transcriptional regulators. We address these issues using single-nucleus RNA-sequencing of 32 000 nuclei representing 9 major liver cell types. Nuclei were extracted from livers from adult male and female mice; from males infused with GH continuously, mimicking the female plasma GH pattern; and from mice exposed to TCPOBOP, a xenobiotic agonist ligand of the nuclear receptor CAR that perturbs sex-biased gene expression. Analysis of these rich transcriptomic datasets revealed the following: 1) expression of sex-biased genes and their GH-dependent transcriptional regulators is primarily restricted to hepatocytes and is not a feature of liver nonparenchymal cells; 2) many sex-biased transcripts show sex-dependent zonation within the liver lobule; 3) gene expression is substantially feminized both in periportal and pericentral hepatocytes when male mice are infused with GH continuously; 4) sequencing nuclei increases the sensitivity for detecting thousands of nuclear-enriched long-noncoding RNAs (lncRNAs) and enables determination of their liver cell type-specificity, sex-bias and hepatocyte zonation profiles; 5) the periportal to pericentral hepatocyte cell ratio is significantly higher in male than female liver; and 6) TCPOBOP exposure disrupts both sex-specific gene expression and hepatocyte zonation within the liver lobule. These findings highlight the complex interconnections between hepatic sexual dimorphism and zonation at the single-cell level and reveal how endogenous hormones and foreign chemical exposure can alter these interactions across the liver lobule with large effects both on protein-coding genes and lncRNAs.

Non-coding RNAs regulating epithelial-mesenchymal transition: Research progress in liver disease

Chronic liver injury could gradually progress to liver fibrosis, cirrhosis, and even hepatic carcinoma without effective treatment. The massive production and activation of abnormal cell differentiation is vital to the procession of liver diseases. Epithelial-mesenchymal transformation (EMT) is a biological process in which differentiated epithelial cells lose their epithelial characteristics and acquire mesenchymal cell migration capacity. Emerging evidence suggests that EMT not only occurs in the process of hepatocellular carcinogenesis, but also appears in liver cells transforming to myofibroblasts, a core event of liver disease. Non-coding RNA (ncRNA) such as microRNA (miRNA), long non-coding RNA (lncRNA) and circular RNA (circRNA) are important regulatory factors in EMT, which can regulate target gene expression by binding with RNA single-stranded. Various studies had shown that ncRNA regulation of EMT plays a key role in liver disease development, and many effective ncRNAs have been identified as promising biomarkers for the diagnosis and treatment of liver disease. In this review, we focus on the relationship between the different ncRNAs and EMT as well as the specific molecular mechanism in the liver diseases to enrich the pathological progress of liver diseases and provide reference for the treatment of liver diseases.

LncRNA-PACERR induces pro-tumour macrophages via interacting with miR-671-3p and m6A-reader IGF2BP2 in pancreatic ductal adenocarcinoma

BACKGROUND

LncRNA-PACERR plays critical role in the polarization of tissue-associated macrophages (TAMs). In this study, we found the function and molecular mechanism of PACERR in TAMs to regulate pancreatic ductal adenocarcinoma (PDAC) progression.

METHODS

We used qPCR to analyse the expression of PACERR in TAMs and M1-tissue-resident macrophages (M1-NTRMs) which were isolated from 46 PDAC tissues. The function of PACERR on macrophages polarization and PDAC proliferation, migration and invasion were confirmed through in vivo and in vitro assays. The molecular mechanism of PACERR was discussed via fluorescence in situ hybridization (FISH), RNA pull-down, ChIP-qPCR, RIP-qPCR and luciferase assays.

RESULTS

LncRNA-PACERR was high expression in TAMs and associated with poor prognosis in PDAC patients. Our finding validated that LncRNA-PACERR increased the number of M2-polarized cells and facilized cell proliferation, invasion and migration in vitro and in vivo. Mechanistically, LncRNA-PACERR activate KLF12/p-AKT/c-myc pathway by binding to miR-671-3p. And LncRNA-PACERR which bound to IGF2BP2 acts as an m6A-dependent manner to enhance the stability of KLF12 and c-myc in cytoplasm. In addition, the promoter of LncRNA-PACERR was a target of KLF12 and LncRNA-PACERR recruited EP300 to increase the acetylation of histone by interacting with KLF12 in nucleus.

CONCLUSIONS

This study found that LncRNA-PACERR functions as key regulator of TAMs in PDAC microenvironment and revealed the novel mechanisms in cytoplasm and in nucleus.

Role of long non-coding RNA-adducin 3 antisense RNA1 in liver fibrosis of biliary atresia

Biliary atresia (BA) is a devastating liver disease in neonates. Liver fibrosis is regarded as a universal and prominent feature of BA. Studies have revealed that long non-coding RNAs (lncRNAs) regulate cellular processes during the development of liver fibrosis in BA. Long non-coding RNA-adducin 3 antisense RNA1 (lnc-ADD3-AS1) has been shown to increase susceptibility to BA. However, the role of lnc-ADD3-AS1 in liver fibrosis in BA remains unclear. Here, we investigated the role of lnc-ADD3-AS1 in the proliferation, migration, and apoptosis of the immortalized human hepatic stellate cell (HSC) line, LX-2. We successfully overexpressed and silenced lnc-ADD3-AS1 in LX-2 cells using adenovirus vectors and evaluated the proliferation of transfected cells using the Cell Counting Kit-8 (CCK8) assay. Cell apoptosis was detected using annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI) double staining and flow cytometry. We then analyzed cell migration by performing wound-scratch and transwell migration assays. Our results show that lnc-ADD3-AS1 significantly promoted LX-2 cell proliferation and attenuated apoptosis. More importantly, lncRNA-ADD3-AS1 significantly accelerated the migration of LX-2 cells. Our data indicated that lncRNA-ADD3-AS1 plays a role in the pathogenesis of liver fibrosis in patients with BA and may serve as a potential diagnostic marker for monitoring liver fibrosis in BA or as a therapeutic target for the disease.

Long noncoding RNA SNHG1 silencing accelerates hepatocyte-like cell differentiation of bone marrow-derived mesenchymal stem cells to alleviate cirrhosis via the microRNA-15a/SMURF1/UVRAG axis

Bone marrow-derived mesenchymal stem cells (BMSCs) can differentiate into hepatocyte-like cells (HLCs) to attenuate cirrhosis. Long noncoding RNA (lncRNA) SNHG1 has been demonstrated to orchestrate BMSC differentiation, whereas its role in cirrhosis remains elusive. Therefore, this study was performed to figure out whether lncRNA SNHG1 was involved in cirrhosis by affecting HLC differentiation of BMSCs. Mouse BMSCs were isolated, and the BMSC differentiation into HLCs was induced by hepatocyte growth factor (HGF). A cirrhotic mouse model was established using carbon tetrachloride and phenobarbital, followed by intravenous injection of BMSCs with manipulated expression of lncRNA SNHG1, microRNA (miR)-15a, and SMURF1. Subsequent to HGF induction, expression of hepatocyte-related genes, albumin secretion, and glycogen accumulation was increased in BMSCs, suggesting the differentiation of BMSCs into HLCs. Mechanistically, lncRNA SNHG1 bound to miR-15a that targeted SMURF1, and SMURF1 diminished ATG5 and Wnt5a expression by enhancing the ubiquitination of UVRAG. LncRNA SNHG1 or SMURF1 silencing or miR-15a overexpression promoted differentiation of BMSCs into HLCs and repressed cirrhosis of mice by upregulating ATG5 and Wnt5a via UVRAG. Conclusively, lncRNA SNHG1 silencing might facilitate HLC differentiation from mouse BMSCs and alleviate cirrhosis via the miR-15a/SMURF1/UVRAG/ATG5/Wnt5a axis.

lncRNA MEG3 modulates hepatic stellate cell activation by sponging miR‑145 to regulate PPARγ

It is important to determine the mechanism of liver fibrosis for targeted therapy and the development of targeted therapies for liver fibrosis may offer promise for patients with liver disease. Long non‑coding RNAs (lncRNAs) serve a role in hepatic fibrosis. The lncRNA maternally expressed gene 3 (MEG3) has been confirmed to inhibit liver fibrosis. The present study investigated the role of the MEG3 in healthy patients and patients with liver fibrosis. The expression levels of MEG3 and microRNA (miR)‑145 in the serum of healthy volunteers and patients with liver fibrosis and in LX‑2 cells were detected using reverse transcription‑quantitative PCR. A dual‑luciferase reporter assay was used to determine the targeting relationship between MEG3 and miR‑145, and the targeting relationship between miR‑145 and peroxisome proliferator‑activated receptor γ (PPARγ). The protein expression levels of PPARγ, α‑smooth muscle actin (α‑SMA) and collagen I (COL1A1) were detected using western blotting. The expression levels of α‑SMA and COL1A1 were also determined using immunofluorescence. Finally, a Cell Counting Kit‑8 assay was performed to assess the proliferative ability of LX‑2 cells. A significantly reduced MEG3 expression level was demonstrated in serum from patients with liver fibrosis compared with serum from healthy controls. TGF‑β1 induced a significantly decreased MEG3 expression level in LX‑2 human hepatic stellate cells in vitro. The TGF‑β1‑induced increases in cell proliferation and α‑SMA and COL1A1 protein expression levels were reversed following MEG3 overexpression. The results also demonstrated that MEG3 sponged miR‑145 and competed endogenously with miR‑145 to regulate PPARγ. In summary, the present study identified MEG3 as an anti‑fibrotic lncRNA and provided new information regarding the role of MEG3 in liver fibrosis. MEG3 may therefore be a potential target in the treatment of liver fibrosis.

Nonalcoholic Fatty Liver Disease (NAFLD): Pathogenesis and Noninvasive Diagnosis

The global prevalence of nonalcoholic fatty liver disease (NAFLD) or metabolic associated fatty liver disease (MAFLD), as it is now known, has gradually increased. NAFLD is a disease with a spectrum of stages ranging from simple fatty liver (steatosis) to a severe form of steatosis, nonalcoholic steatohepatitis (NASH), which could progress to irreversible liver injury (fibrosis) and organ failure, and in some cases hepatocellular carcinoma (HCC). Although a liver biopsy remains the gold standard for accurate detection of this condition, it is unsuitable for clinical screening due to a higher risk of death. There is thus an increased need to find alternative techniques or tools for accurate diagnosis. Early detection for NASH matters for patients because NASH is the marker for severe disease progression. This review summarizes the current noninvasive tools for NAFLD diagnosis and their performance. We also discussed potential and newer alternative tools for diagnosing NAFLD.

Long noncoding RNA RP11-909N17.2 presages a poor prognosis of non-small cell lung cancer

BACKGROUND

Long non-coding RNAs (lncRNAs) were detected extraordinarily expressed in various tumors and could combine with microRNAs (miRNAs) to play important role in tumor cells. This study is to explore the role of lncRNA RP11-909N17.2 in NSCLC and discuss in what way it functions in NSCLC.

METHODS

120 NSCLC patients were enlisted in this study. Expression levels of lncRNA RP11-909N17.2 and miR-767-3p were detected and the correlation between lncRNA RP11-909N17.2 expression and the clinical data characteristics was analyzed. Prognosis potential of lncRNA RP11-909N17.2 was inferred with Kaplan-Meier and multivariate Cox regression assays. Biological functions of NSCLC cells were accessed by cell counting Kit-8, transwell migration and invasion assay. Mechanism of RP11-909N17.2 action on NSCLC cells was investigated by luciferase activity assay with wide-type or mutation.

RESULTS

LncRNA RP11-909N17.2 has an ascendant expression while miR-767-3p has descended one in NSCLC tissue specimens and cells. Over-expression of lncRNA RP11-909N17.2 can shorten the overall survival period of NSCLC patients when compared with low expression. Knockdown of lncRNA RP11-909N17.2 suppressed biology function of NSCLC cell including proliferation, migration, and invasion.

CONCLUSION

LncRNA RP11-909N17.2 can be developed into a prognostic index for NSCLC. LncRNA RP11-909N17.2 plays a promoting role in NSCLC cells possibly by binding miR-767-3p as a sponge.

The Roles and Mechanisms of lncRNAs in Liver Fibrosis

Long non-coding RNAs (lncRNAs) can potentially regulate all aspects of cellular activity including differentiation and development, metabolism, proliferation, apoptosis, and activation, and benefited from advances in transcriptomic and genomic research techniques and database management technologies, its functions and mechanisms in physiological and pathological states have been widely reported. Liver fibrosis is typically characterized by a reversible wound healing response, often accompanied by an excessive accumulation of extracellular matrix. In recent years, a range of lncRNAs have been investigated and found to be involved in several cellular-level regulatory processes as competing endogenous RNAs (ceRNAs) that play an important role in the development of liver fibrosis. A variety of lncRNAs have also been shown to contribute to the altered cell cycle, proliferation profile associated with the accelerated development of liver fibrosis. This review aims to discuss the functions and mechanisms of lncRNAs in the development and regression of liver fibrosis, to explore the major lncRNAs involved in the signaling pathways regulating liver fibrosis, to elucidate the mechanisms mediated by lncRNA dysregulation and to provide new diagnostic and therapeutic strategies for liver fibrosis.

Competing Endogenous RNA Network in Non-Keloid-Prone Individuals During Wound Healing

ABSTRACT

To study the interaction between differentially expressed long non-coding RNAs (lncRNAs), microRNAs, and messenger RNAs during wound healing in normal individuals. The GSE113621 dataset was downloaded from gene expression matrix, specimens regarding non-keloid-prone individuals were selected, including items before and 6 weeks after injury. A Pearson correlation coefficient of > 0.95 was selected as the index to screen targeting relationships among different RNAs. Cytoscape was used to construct a network diagram. The expression of 2547 lncRNAs was changed during the wound healing process-1479 were upregulated and 1068 were downregulated. After analyzing competitive endogenous RNA network, 4 upregulated (MEG8, MEG3, MIR181A1HG, MIR4435-2HG) lncRNAs were found expressed during wound healing. MEG8/MEG3 may regulate fibroblast proliferation, differentiation, and apoptosis through hsa-miR-296-3p/miR-6763-5p. In-depth mining of gene expression matrix data indicated that lncRNAs and a competitive endogenous RNA regulatory network participate in the wound healing process, possibly providing novel intervention targets and treatment options for delayed wound healing.

Long non‑coding RNA MBI‑52 inhibits the development of liver fibrosis by regulating the microRNA‑466g/SMAD4 signaling pathway

Liver fibrosis is a wound healing response triggered by liver injury. In severe cases, it may develop into liver cirrhosis, liver cancer and liver failure. Long non-coding RNAs (lncRNAs) play key roles in the development of liver fibrosis. The present study aimed to investigate the role of lncRNA-MBI-52 (lnc-MBI-52) in the progression of liver fibrosis. Carbon tetrachloride (CCl₄)-induced injury was performed to establish a mouse liver fibrosis model, and exogenous transforming growth factor-β1 was used to establish a hepatic stellate cell (HSC) activation model. Reverse transcription-quantitative PCR and western blot analyses were performed to detect mRNA and protein expression, respectively. RNA pull-down assay was performed to assess the interaction between microRNA (miR)-466g and lnc-MBI-52 or SMAD4. Dual-luciferase reporter assay was performed to verify the target of miR-466g. lnc-MBI-52 was overexpressed in CCl₄-induced mouse liver fibrosis models and activated HSCs. lnc-MBI-52 knockdown suppressed liver fibrosis in vitro. Moreover, knockdown of lnc-MBI-52 downregulated α-smooth muscle actin and collagen type I expression. In addition, lnc-MBI-52 and SMAD4 were identified as targets of miR-466g. The effects of lnc-MBI-52 on HSC activation were reversed following transfection with miR-466g mimics or SMAD4 knockdown. lnc-MBI-52 miR-466g significantly decreased lnc-MBI-52 expression, while overexpression of lnc-MBI-52 suppressed miR-466g expression. The results of the RNA pull-down assay confirmed the interaction between miR-466g and lnc-MBI-52. Taken together, lnc-MBI-52 induced liver fibrosis by regulating the miR-466g/SMAD4 axis, which may provide a new possible strategy for liver fibrosis.

LncRNA MALAT1-deficiency restrains lipopolysaccharide (LPS)-induced pyroptotic cell death and inflammation in HK-2 cells by releasing microRNA-135b-5p

Long non-coding RNAs (LncRNAs) participate in the regulation of chronic kidney disease (CKD), and acute kidney injury (AKI) is identified as an important risk factor for CKD. This study investigated the involvement of a novel LncRNA MALAT1 in regulating lipopolysaccharide (LPS)-induced cell pyroptosis and inflammation in the human renal tubular epithelial HK-2 cells. Here, the HK-2 cells were subjected to LPS (2 μg/mL) treatment to establish cellular AKI models in vitro, and we validated that LPS triggered NLRP3-mediated pyroptotic cell death, promoted cell apoptosis and inflammation-associated cytokines secretion to induce HK-2 cell injury. Then, a novel LncRNA MALAT1/miRNA (miRNA)-135b-5p axis was verified to rescue cell viability in LPS treated HK-2 cells by targeting NLRP3. Mechanistically, miRNA-135b-5p bound to LncRNA MALAT1, and LncRNA MALAT1 positively regulated NLRP3 through acting as RNA sponger for miRNA-135b-5p. Further gain- and loss-of-function experiments evidenced that both LncRNA MALAT1 ablation and miRNA-135b-5p overexpression reversed LPS-induced cell pyroptosis, apoptosis, and inflammation in the HK-2 cells, and the protective effects of LncRNA MALAT1 knock-down on LPS-treated HK-2 cells were abrogated by silencing miRNA-135b-5p. In general, our study firstly investigated the role of the LncRNA MALAT1/ miRNA-135b-5p/NLRP3 signaling cascade in regulating LPS-induced inflammatory death in HK-2 cells.

Noncoding RNAs Interactions in Hepatic Stellate Cells during Hepatic Fibrosis

Hepatic fibrosis is a reversible wound healing process following liver injury. Although this process is necessary for maintaining liver integrity, severe excessive extracellular matrix accumulation (ECM) could lead to permanent scar formation and destroy the liver structure. The activation of hepatic stellate cells (HSCs) is a key event in hepatic fibrosis. Previous studies show that most antifibrotic therapies focus on the apoptosis of HSCs and the prevention of HSC activation. Noncoding RNAs (ncRNAs) play a substantial role in HSC activation and are likely to be biomarkers or therapeutic targets for the treatment of hepatic fibrosis. This review summarizes and discusses the previously reported ncRNAs, including the microRNAs, long noncoding RNAs, and circular RNAs, highlighting their regulatory roles and interactions in the signaling pathways that regulate HSC activation in hepatic fibrosis.