The let-7/Lin28 axis regulates activation of hepatic stellate cells in alcoholic liver injury

Molecular regulators of alcoholic liver disease: a comprehensive analysis of microRNAs and long non-coding RNAs

Many biomolecules and signaling pathways are involved in the development of alcoholic liver disease (ALD). The molecular mechanisms of ALD are not fully understood and there is no effective treatment. Numerous studies have demonstrated the critical role of non-coding RNAs, including long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), in ALD. miRNAs play an important regulatory role in the pathogenesis of ALD by controlling critical biological processes such as inflammation, oxidative stress, lipid metabolism, apoptosis and fibrosis. Among them, miR-155, miR-223 and miR-34a play a central role in these processes and influence the pathological process of ALD. In addition, lncRNAs are involved in regulating liver injury and repair by interacting with miRNAs to form a complex regulatory network. These findings help to elucidate the molecular mechanisms of ALD and provide a scientific basis for the development of new diagnostic markers and therapeutic targets. In this article, we review the roles and mechanisms of LncRNAs and miRNAs in ALD and their potential use as diagnostic markers and therapeutic targets.

Let‑7f‑5p Regulated by Hsa_circ_0000437 Ameliorates Bleomycin-Induced Skin Fibrosis

The current treatment of skin fibrosis is limited in its effectiveness due to a lack of understanding of the underlying mechanisms. Previous research has shown a connection between microRNAs (miRNAs) and the development of skin fibrosis. Therefore, investigating miRNA for the treatment of skin fibrotic diseases is highly important and merits further exploration. In this study, we have discovered that let-7f-5p could suppress the proliferation, migration, and expression of collagen type I alpha 1 (COL1A1) in human dermal fibroblasts (HDFs). It was further determined that let-7f-5p could target thrombospondin-1 (THBS1), thereby inhibiting the TGF-β2/Smad3 signaling pathway and exerting its biological effects. Additionally, let-7f-5p is regulated by Hsa_circ_0000437, which acts as a sponge molecule for let-7f-5p and consequently regulates the biological function of HDFs. Furthermore, our findings indicate that in vivo overexpression of let-7f-5p leads to a reduction in dermal thickness and COL1A1 expression, effectively inhibiting the progression of bleomycin (BLM)-induced skin fibrosis in mice. Hence, our research enhances the comprehension of the Hsa_circ_0000437/let-7f-5p/THBS1/TGF-β2/Smad3 regulatory network, highlighting the potential of let-7f-5p as a therapeutic approach for the treatment of skin fibrosis.

Diazepam inhibits LPS-induced pyroptosis and inflammation and alleviates pulmonary fibrosis in mice by regulating the let-7a-5p/MYD88 axis

BACKGROUND AND OBJECTIVE

Pulmonary fibrosis caused by lung injury is accompanied by varying degrees of inflammation, and diazepam can reduce the levels of inflammatory factors. Therefore, the purpose of this study was to determine whether diazepam can inhibit inflammation and ameliorate pulmonary fibrosis by regulating the let-7a-5p/myeloid differentiation factor 88 (MYD88) axis.

METHODS

Lipopolysaccharide (LPS) was used to induce cell pyroptosis in an animal model of pulmonary fibrosis. After treatment with diazepam, changes in cell proliferation and apoptosis were observed, and the occurrence of inflammation and pulmonary fibrosis in the mice was detected.

RESULTS

The results showed that LPS can successfully induce cell pyroptosis and inflammatory responses and cause lung fibrosis in mice. Diazepam inhibits the expression of pyroptosis-related factors and inflammatory factors; moreover, it attenuates the occurrence of pulmonary fibrosis in mice. Mechanistically, diazepam can upregulate the expression of let-7a-5p, inhibit the expression of MYD88, and reduce inflammation and inhibit pulmonary fibrosis by regulating the let-7a-5p/MYD88 axis.

CONCLUSION

Our findings indicated that diazepam can inhibit LPS-induced pyroptosis and inflammatory responses and alleviate pulmonary fibrosis in mice by regulating the let-7a-5p/MYD88 axis.

miRNAs in patients with alcoholic liver disease: a systematic review and meta-analysis

INTRODUCTION

Alcoholic liver disease (ALD) encompasses a spectrum of liver conditions, including liver steatosis, alcoholic hepatitis (AH), fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). microRNAs (miRNAs) have garnered significant interest as potential biomarkers for ALD.

METHODS

We searched PubMed, Embase, Web of Science and Cochrane Central Register of Controlled Trials (CENTRAL) systemically from inception to June 2024. All extracted data was stratified according to the stages of ALD. The vote-counting strategy performed a meta-analysis on miRNA expression profiles.

RESULTS

We included 40 studies. In serum of individuals with alcohol-use vs. no alcohol-use, miRNA-122 and miRNA-155 were upregulated, and miRNA-146a was downregulated. In patients with ALD vs. healthy controls, miRNA-122 and miRNA-155 were also upregulated, and miRNA-146a was downregulated. However, in patients with AH vs. healthy individuals, only the serum miRNA-122 level was upregulated. Due to insufficient data on diagnostic accuracy, we failed to conclude the ability of miRNAs to distinguish between different stages of ALD-related liver fibrosis. The results for ALD-related HCC were also insufficient and controversial.

CONCLUSIONS

Circulating miRNA-122 was the most promising biomarker to manage individuals with ALD. More studies were needed for the diagnostic accuracy of miRNAs in ALD.

REGISTRATION

This protocol was registered on the International Prospective Register of Systematic Reviews (PROSPERO) (www.crd.york.ac.uk/prospero/) with registration number CRD42023391931.

MiRNA-766-3p inhibits gastric cancer via targeting COL1A1 and regulating PI3K/AKT signaling pathway

Objective MiRNA-766-3p has been shown to be associated with a variety of cancers. However, few studies have been done in gastric cancer (GC). This study explores the mechanism of miR-766-3p in GC. Methods The potential targets of microRNA (miRNA) were predicted using Tarbase and Targetscan databases. The results are intersected with differential genes (DEGs) (fold change > 1.5, P < 0.05) in gastric cancer to obtain potential core targets. The hub targets screened by constructing PPI networks (degree > 5, expression > 0.5). Validating the differential expression and expression in immunohistochemistry of these targets through the database. And the binding sites between miRNAs and mRNAs were verified using dual-luciferase Assay. Finally, qRT-PCR and Western Blot experiments were conducted to validate the hub targets and signal pathways. Results The potential hub targets from the PPI network were THBS2, COL1A1, FGG, FGB, and PLAU. Combining database, luciferase Assay and experimental validation, miR-766-3p can sponge COL1A1 and it plays the most important role in gastric cancer progression. In GC, COL1A1 was upregulated and the enrichment analysis revealed that COL1A1 regulates PI3K/AKT signal pathway, and AKT is also highly expressed in gastric cancer. Conclusion The miR-766-3p can inhibit the progression of gastric cancer by targeting COL1A1 and regulating the PI3K/AKT signal pathway. It could be a potential therapy option for the GC.

MiRNAs in Alcohol-Related Liver Diseases and Hepatocellular Carcinoma: A Step toward New Therapeutic Approaches?

Alcohol-related Liver Disease (ALD) is the primary cause of chronic liver disorders and hepatocellular carcinoma (HCC) development in developed countries and thus represents a major public health concern. Unfortunately, few therapeutic options are available for ALD and HCC, except liver transplantation or tumor resection for HCC. Deciphering the molecular mechanisms underlying the development of these diseases is therefore of major importance to identify early biomarkers and to design efficient therapeutic options. Increasing evidence indicate that epigenetic alterations play a central role in the development of ALD and HCC. Among them, microRNA importantly contribute to the development of this disease by controlling the expression of several genes involved in hepatic metabolism, inflammation, fibrosis, and carcinogenesis at the post-transcriptional level. In this review, we discuss the current knowledge about miRNAs' functions in the different stages of ALD and their role in the progression toward carcinogenesis. We highlight that each stage of ALD is associated with deregulated miRNAs involved in hepatic carcinogenesis, and thus represent HCC-priming miRNAs. By using in silico approaches, we have uncovered new miRNAs potentially involved in HCC. Finally, we discuss the therapeutic potential of targeting miRNAs for the treatment of these diseases.

Metformin regulates the LIN28B‑mediated JNK/STAT3 signaling pathway through miR‑140‑3p in subretinal fibrosis

Subretinal fibrosis (SF) is an important cause of submacular neovascularization that leads to permanent vision loss, but has no effective clinical treatment. The present study examined the influence of metformin on SF, and investigated whether the mechanism involves the microRNA (miR)-140-3p/LIN28B/JNK/STAT3-mediated regulation of oxidative stress, angiogenesis and fibrosis-associated indicators. A mouse model of laser-induced SF was established. In addition, an ARPE-19 fibrotic cell model was established using TGF-β1. A Cell Counting Kit-8 assay was used to examine cell viability. Flow cytometry was used to measure reactive oxygen species levels, and western blotting was used to detect the levels of proteins associated with epithelial-mesenchymal transition (EMT), signaling and fibrosis. The levels of superoxide dismutase, malondialdehyde, glutathione-peroxidase and catalase were measured using kits. Scratch assays and Transwell assays were used to assess cell migration and invasion, respectively, and reverse transcription-quantitative PCR was used to determine the levels of miR-140-3p and LIN28B. Dual-luciferase assays were used to verify the targeting relationship between miR-140-3p and LIN28B, and coimmunoprecipitation was used to confirm the interaction between LIN28B and JNK. Masson staining and hematoxylin and eosin staining were used to examine collagenous fibers and the histopathology of eye tissue. In ARPE-19 cells induced by TGF-β1, metformin promoted miR-140-3p expression and inhibited LIN28B expression and JNK/STAT3 pathway activation, thereby inhibiting oxidative stress, EMT and fibrosis in ARPE-19 cells. The overexpression of LIN28B or treatment with the JNK/STAT3 agonist anisomycin partially reversed the inhibitory effect of metformin on oxidative stress and fibrosis in ARPE-19 cells. The dual-luciferase reporter assay and coimmunoprecipitation assay showed that miR-140-3p targeted the 3' untranslated region of LIN28B mRNA and inhibited LIN28B expression. LIN28B targeted and bound to JNK and regulated the JNK/STAT3 pathway. Therefore, it may be concluded that metformin can promote miR-140-3p expression, inhibit LIN28B and then inhibit the JNK/STAT3 pathway to alleviate SF.

DAGLβ is the principal synthesizing enzyme of 2-AG and promotes aggressive phenotype of intrahepatic cholangiocarcinoma via AP-1/DAGLβ/miR4516 feedforward circuitry

The endocannabinoid system (ECS) is dysregulated in various liver diseases. Previously, we had shown that the major endocannabinoid 2-arachidonoyl glycerol (2-AG) promoted tumorigenesis of intrahepatic cholangiocarcinoma (ICC). However, biosynthesis regulation and clinical significance of 2-AG remain elusive. In the present study, we quantified 2-AG by gas chromatography/mass spectrometry (GC/MS) and showed that 2-AG was enriched in patients with ICC samples as well as in thioacetamide-induced orthotopic rat ICC model. Moreover, we found that diacylglycerol lipase β (DAGLβ) was the principal synthesizing enzyme of 2-AG that significantly upregulated in ICC. DAGLβ promoted tumorigenesis and metastasis of ICC in vitro and in vivo and positively correlated with clinical stage and poor survival in patients with ICC. Functional studies showed that activator protein-1 (AP-1; heterodimers of c-Jun and FRA1) directly bound to the promoter and regulated transcription of DAGLβ, which can be enhanced by lipopolysaccharide (LPS). miR-4516 was identified as the tumor-suppressing miRNA of ICC that can be significantly suppressed by LPS, 2-AG, or ectopic DAGLβ overexpression. FRA1 and STAT3 were targets of miR-4516 and overexpression of miRNA-4516 significantly suppressed expression of FRA1, SATA3, and DAGLβ. Expression of miRNA-4516 was negatively correlated with FRA1, SATA3, and DAGLβ in patients with ICC samples. Our findings identify DAGLβ as the principal synthesizing enzyme of 2-AG in ICC. DAGLβ promotes oncogenesis and metastasis of ICC and is transcriptionally regulated by a novel AP-1/DAGLβ/miR4516 feedforward circuitry.NEW & NOTEWORTHY Dysregulated endocannabinoid system (ECS) had been confirmed in various liver diseases. However, regulation and function of 2-arachidonoyl glycerol (2-AG) and diacylglycerol lipase β (DAGLβ) in intrahepatic cholangiocarcinoma (ICC) remain to be elucidated. Here, we demonstrated that 2-AG was enriched in ICC, and DAGLβ was the principal synthesizing enzyme of 2-AG in ICC. DAGLβ promotes tumorigenesis and metastasis in ICC via a novel activator protein-1 (AP-1)/DAGLβ/miR4516 feedforward circuitry.

Pathogenesis of Alcoholic Fatty Liver a Narrative Review

Alcohol effect hepatic lipid metabolism through various mechanisms, leading synergistically to an accumulation of fatty acids (FA) and triglycerides. Obesity, as well as dietary fat (saturated fatty acids (FA) versus poly-unsaturated fatty acids (PUFA)) may modulate the hepatic fat. Alcohol inhibits adenosine monophosphate activated kinase (AMPK). AMPK activates peroxisome proliferator activated receptor a (PPARα) and leads to a decreased activation of sterol regulatory element binding protein 1c (SRABP1c). The inhibition of AMPK, and thus of PPARα, results in an inhibition of FA oxidation. This ß-oxidation is further reduced due to mitochondrial damage induced through cytochrome P4502E1 (CYP2E1)-driven oxidative stress. Furthermore, the synthesis of FAs is stimulated through an activation of SHREP1. In addition, alcohol consumption leads to a reduced production of adiponectin in adipocytes due to oxidative stress and to an increased mobilization of FAs from adipose tissue and from the gut as chylomicrons. On the other side, the secretion of FAs via very-low-density lipoproteins (VLDL) from the liver is inhibited by alcohol. Alcohol also affects signal pathways such as early growth response 1 (Egr-1) associated with the expression of tumour necrosis factor α (TNF α), and the mammalian target of rapamycin (mTOR) a key regulator of autophagy. Both have influence the pathogenesis of alcoholic fatty liver. Alcohol-induced gut dysbiosis contributes to the severity of ALD by increasing the metabolism of ethanol in the gut and promoting intestinal dysfunction. Moreover, pathogen-associated molecular patterns (PAMPS) via specific Toll-like receptor (TLR) bacterial overgrowth leads to the translocation of bacteria. Endotoxins and toxic ethanol metabolites enter the enterohepatic circulation, reaching the liver and inducing the activation of the nuclear factor kappa-B (NFκB) pathway. Pro-inflammatory cytokines released in the process contribute to inflammation and fibrosis. In addition, cellular apoptosis is inhibited in favour of necrosis.

Reviewing the Regulators of COL1A1

The collagen family contains 28 proteins, predominantly expressed in the extracellular matrix (ECM) and characterized by a triple-helix structure. Collagens undergo several maturation steps, including post-translational modifications (PTMs) and cross-linking. These proteins are associated with multiple diseases, the most pronounced of which are fibrosis and bone diseases. This review focuses on the most abundant ECM protein highly implicated in disease, type I collagen (collagen I), in particular on its predominant chain collagen type I alpha 1 (COLα1 (I)). An overview of the regulators of COLα1 (I) and COLα1 (I) interactors is presented. Manuscripts were retrieved searching PubMed, using specific keywords related to COLα1 (I). COL1A1 regulators at the epigenetic, transcriptional, post-transcriptional and post-translational levels include DNA Methyl Transferases (DNMTs), Tumour Growth Factor β (TGFβ), Terminal Nucleotidyltransferase 5A (TENT5A) and Bone Morphogenic Protein 1 (BMP1), respectively. COLα1 (I) interacts with a variety of cell receptors including integrinβ, Endo180 and Discoidin Domain Receptors (DDRs). Collectively, even though multiple factors have been identified in association to COLα1 (I) function, the implicated pathways frequently remain unclear, underscoring the need for a more spherical analysis considering all molecular levels simultaneously.

HMGA2 knockdown alleviates the progression of nonalcoholic fatty liver disease (NAFLD) by downregulating SNAI2 expression

Non-alcoholic fatty liver disease (NAFLD) is a complex disease that is considered as the next major health epidemic with alarmingly increasing global prevalence. To explore the pathogenesis of NAFLD, data from GSE118892 were analyzed. High mobility group AT-hook 2 (HMGA2), a member of the high mobility group family, is declined in liver tissues of NAFLD rats. However, its role in NAFLD remains unknown. This study attempted to identify the multiple roles of HMGA2 in NAFLD process. NAFLD was induced in rats using a high-fat diet (HFD). In vivo, HMGA2 knockdown using adenovirus system attenuated liver injury and liver lipid deposition, accompanied by decreased NAFLD score, increased liver function, and decreased CD36 and FAS, indicating the deceleration of NAFLD progression. Moreover, HMGA2 knockdown restrained liver inflammation by decreasing the expression of related inflammatory factors. Importantly, HMGA2 knockdown attenuated liver fibrosis via downregulating the expression of fibrous proteins, and inhibiting the activation of TGF-β1/SMAD signaling pathway. In vitro, HMGA2 knockdown relieved palmitic acid (PA)-induced hepatocyte injury and attenuated TGF-β1-induced liver fibrosis, consistent with in vivo findings. Strikingly, HMGA2 activated the transcription of SNAI2, which was evidenced by the dual luciferase assays. Moreover, HMGA2 knockdown largely downregulated SNAI2 levels. Indeed, SNAI2 overexpression effectively blocked the inhibitory effect of HMGA2 knockdown on NAFLD. Totally, our findings reveal that HMGA2 knockdown alleviates the progression of NAFLD by directly regulating the transcription of SNAI2. HMGA2 inhibition may emerge as a potential therapeutic target for NAFLD.

An Insight into the Arising Role of MicroRNAs in Hepatocellular Carcinoma: Future Diagnostic and Therapeutic Approaches

Hepatocellular carcinoma (HCC) constitutes a frequent highly malignant form of primary liver cancer and is the third cause of death attributable to malignancy. Despite the improvement in the therapeutic strategies with the exploration of novel pharmacological agents, the survival rate for HCC is still low. Shedding light on the multiplex genetic and epigenetic background of HCC, such as on the emerging role of microRNAs, is considered quite promising for the diagnosis and the prediction of this malignancy, as well as for combatting drug resistance. MicroRNAs (miRNAs) constitute small noncoding RNA sequences, which play a key role in the regulation of several signaling and metabolic pathways, as well as of pivotal cellular functions such as autophagy, apoptosis, and cell proliferation. It is also demonstrated that miRNAs are significantly implicated in carcinogenesis, either acting as tumor suppressors or oncomiRs, while aberrations in their expression levels are closely associated with tumor growth and progression, as well as with local invasion and metastatic dissemination. The arising role of miRNAs in HCC is in the spotlight of the current scientific research, aiming at the development of novel therapeutic perspectives. In this review, we will shed light on the emerging role of miRNAs in HCC.

XIST/let-7i/HMGA1 axis maintains myofibroblasts activities in oral submucous fibrosis

Long non-coding RNA XIST promotes the development of various types of head and neck cancers, but its role in the progression of precancerous oral submucous fibrosis (OSF) has not been determined yet. As such, we aimed to examine whether XIST implicates in the regulation of myofibroblast activation. Our results showed that the expression of XIST was upregulated in OSF tissues and fibrotic buccal mucosal fibroblasts (fBMFs), and the silencing of XIST downregulated several myofibroblasts features. We demonstrated that elevation of let-7i after inhibition of XIST may lead to reduced myofibroblast activation. On the contrary, overexpression of high mobility group AT-Hook 1 (HMGA1) following the suppression of let-7i may result in enhanced myofibroblast activities. Moreover, we showed that the suppressive effect of silencing of XIST on myofibroblasts hallmarks was reversed by let-7i inhibition or HMGA1 overexpression, suggesting the pro-fibrotic property of XIST was mediated by downregulation of let-7i and upregulation of HMGA1. These findings revealed that myofibroblast activation of fBMFs may attribute to the alteration of the XIST/let-7i/HMGA1 axis. Therapeutic approaches to target this axis may serve as a promising direction to ameliorate the malignant progression of OSF.

Pharmacological inhibition of Lin28 promotes ketogenesis and restores lipid homeostasis in models of non-alcoholic fatty liver disease

Lin28 RNA-binding proteins are stem-cell factors that play key roles in development. Lin28 suppresses the biogenesis of let-7 microRNAs and regulates mRNA translation. Notably, let-7 inhibits Lin28, establishing a double-negative feedback loop. The Lin28/let-7 axis resides at the interface of metabolic reprogramming and oncogenesis and is therefore a potential target for several diseases. In this study, we use compound-C1632, a drug-like Lin28 inhibitor, and show that the Lin28/let-7 axis regulates the balance between ketogenesis and lipogenesis in liver cells. Hence, Lin28 inhibition activates synthesis and secretion of ketone bodies whilst suppressing lipogenesis. This occurs at least partly via let-7-mediated inhibition of nuclear receptor co-repressor 1, which releases ketogenesis gene expression mediated by peroxisome proliferator-activated receptor-alpha. In this way, small-molecule Lin28 inhibition protects against lipid accumulation in multiple cellular and male mouse models of hepatic steatosis. Overall, this study highlights Lin28 inhibitors as candidates for the treatment of hepatic disorders of abnormal lipid deposition.

Beneficial Effects of Milk-Derived Extracellular Vesicles on Liver Fibrosis Progression by Inhibiting Hepatic Stellate Cell Activation

Liver fibrosis is the consequence of various chronic liver diseases, resulting in accumulation of extracellular matrix, following the activation and proliferation of hepatic stellate cells (HSCs). Based on the milk-derived extracellular vesicles’ (MDEs’) characteristics and biological proprieties, we investigate whether MDEs may regulate fibrotic progression by inhibiting HSCs’ activation via the MDEs’ miRNA content. In order to study this question, we examined the effect of human and cow MDEs on HSCs isolated from murine livers, on activation, proliferation and their proteins’ expression. We have shown that MDEs are able to enter into HSCs in vitro and into the livers in vivo. MDEs inhibited HSCs’ proliferation following stimulation with PDGF. Moreover, in vivo treatment with MDEs resulted in an increase of in miRNA-148 and Let7a expression in HSCs. In contrast, treatment with MDEs reduced the expression of miR-21 in HSCs. In addition, MDEs regulate HSC activation, as was shown by downregulation of collagen I expression and alpha smooth muscle actin, and upregulation of PPARγ. MDEs carrying beneficial miRNAs can be a nontoxic natural target for treatment of liver cirrhosis.

Effects of Let-7c on the processing of hepatitis B virus associated liver diseases

Background

The most common type of cancer of the digestive system is hepatocellular carcinoma. In China, many patients harbour HBV. The lin28B/Let-7c/MYC axis is associated with the occurrence of many cancers. Therefore, we aimed to illuminate the function of the lin28B/Let-7c/MYC axis in hepatocellular carcinoma. We aimed to evaluate the critical involvement of lin28B and Let-7c in the carcinogenesis of human hepatocellular carcinoma (B-HCC).

Methods

Data from the GEO database were used to analyse differentially expressed genes and IRGs. A protein − protein interaction (PPI) network and Venn diagram were generated to analyse relationships. Real-time RT-PCR, Western blotting, and cell counting kit-8 assays were used to examine the association of lin28B, Let-7c, and MYC with cell proliferation.

Results

A total of 2552 functionally annotated differentially expressed RNAs were analysed in HBV patients from the GSE135860 database. In addition, 46 let-7c target genes were screened in HBV patients, and the interactions were analysed through PPI network analysis. The results confirmed that Let-7c and its target genes play a key role in HBV-related diseases. Next, we discovered a gradual decrease in Let-7c expression during the progression from HBV-associated chronic hepatitis (B-CH) and HBV-associated liver cirrhosis (B-LC) to B-HCC. We found evidence for a negative association between lin28B expression and Let-7c expression. The expression of MYC was obviously upregulated when Let-7c was inhibited.

Conclusion

Our results highlight that Let-7c and lin28B participate in the carcinogenesis of HBV-associated diseases through the lin28B/Let-7c/MYC axis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13027-022-00458-8.

Astrocytic IGF-1 and IGF-1R Orchestrate Mitophagy in Traumatic Brain Injury via Exosomal miR-let-7e

Defective brain hormonal signaling and autophagy have been associated with neurodegeneration after brain insults, characterized by neuronal loss and cognitive dysfunction. However, few studies have linked them in the context of brain injury. Insulin-like growth factor-1 (IGF-1) is an important hormone that contributes to growth, cell proliferation, and autophagy and is also expressed in the brain. Here, we assessed the clinical data from TBI patients and performed both in vitro and in vivo experiments with proteomic and gene-chip analysis to assess the functions of IGF-1 in mitophagy following TBI. We show that reduced plasma IGF-1 is correlated with cognition in TBI patients. Overexpression of astrocytic IGF-1 improves cognitive dysfunction and mitophagy in TBI mice. Mechanically, proteomics data show that the IGF-1-related NF-κB pathway transcriptionally regulates decapping mRNA2 (Dcp2) and miR-let-7, together with IGF-1R to orchestrate mitophagy in TBI. Finally, we demonstrate that brain injury induces impaired mitophagy at the chronic stage and that IGF-1 treatment could facilitate the mitophagy markers via exosomal miR-let-7e. By showing that IGF-1 is an important mediator of the beneficial effect of the neural-endocrine network in TBI models, our findings place IGF-1/IGF-1R as a potential target capable of noncoding RNAs and opposing mitophagy failure and cognitive impairment in TBI.

Drug response biomarkers of Pien Tze Huang treatment for hepatic fibrosis induced by carbon tetrachloride

OBJECTIVE

To explore biomarkers of Pien Tze Huang that ameliorated the symptoms of hepatic fibrosis.

METHODS

Two groups of carbon tetrachloride-induced hepatic fibrosis (HF) mice model were constructed in our study: one group received PZH treatment and another group received no treatment. We performed this study to investigate the role of PZH in the regulation process of hepatic fibrosis.

RESULTS

We identified 31 down-regulated and 39 up-regulated miRNAs using small RNA-seq analysis. Combining RNA-Seq data analysis, our study revealed 7 significant target genes (Sp4, Slc2a6, Tln2, Hmga2, Ank3, Pax9, Fgf9). The results of real-time quantitative polymerase chain reaction analysis suggested that the expression level of 6 genes (Sp4, Tln2, Hmga2, Ank3, Pax9, Fgf9) were down-regulated compared to control group. On the other hand, the expression level of Slc2a6 appeared to be up-regulated. The protein mass spectrometry showed that PZH group had lower protein expression of Tln2 compared to control group.

CONCLUSION

We identified 7 genes that were significantly related to PZH response in HF mice using multiple conjoint analysis methods. These genes could participate in underlying regulation mechanism of hepatic fibrosis during PZH treatment.

Reliable miRNA biomarker quantification in clinical practice - are we there yet?

Blood-borne miRNAs serve as disease diagnostic biomarkers and await clinical validation. Here, we evaluated Cel-miR-39-3p and miRNA16-5p as calibrator for the quantification of 15 miRNAs linked to hepatic impairment. We added defined copy numbers of Cel-miR-39-3p to plasma of healthy controls (N = 5) and patient samples undergoing liver resection (N = 51). The miRNAs were isolated according to SOPs and quantified by RT-qPCR using the 2^-(ΔΔ-CT)-method. Although miRNA16-5p and the spike-in control behaved similar in qPCR assays (R² = 0.8591) the spike-in control suffered from high inter-patient variability (median 7.6-fold) and low recoveries (median 5.6%, 95% CI 1.5-11.8%). Adding Cel-miR-39-3p to blood samples prior to RNA-isolation improved the recoveries (median 105.7%; 95% CI 29.9-219.9%), yet the inter-patient variability remained high (median 7.2-fold). Alike, we observed significant variability in CT-values for miRNA16-5p (range 14.7-fold) thus rendering this internal, blood-borne reference gene unacceptable as comparator. Specifically, 10 out of 15 diagnostic miRNAs failed the criteria R² ≥ 0.8 even though we added a defined copy number of Cel-miR-39-3p. This suggests interference of the spike-in control with individual miRNAs in the assay. Our study highlights current limitations in the quantification of blood-borne miRNAs that is of particularly importance when used for disease diagnostic and therapeutic interventions.

MicroRNA let-7b inhibits hepatitis C virus and induces apoptosis in human hepatoma cells

BACKGROUND

Small non-coding RNAs have emerged as essential modulators of viral infections such as hepatitis C virus (HCV). Cellular miRNAs directly regulate the viral infectivity and indirectly by targeting virus-host factors. The current study investigates the inhibitory effect of let-7b miRNA on HCV replication in the Hepatocarcinoma cell line (Huh7.5).

METHODS AND RESULTS

The algorithm-based search revealed that let-7b, a high score microRNA, has target sequences on the HCV genome. The Huh7.5 cells were stably transduced with let-7b lentiviral vectors (Huh7.5/let-7b) and mock (Huh7.5/scrambled). The expression of the let-7b level was assessed by real-time PCR assay and Red fluorescence microscope. A dual-luciferase assay was conducted to evaluate the liver-specific let-7b and HCV genome interaction. In the next step, for establishing HCVcc, Full-length HCV-RNA was transduced to naïve Huh7.5, Huh7.5/scrambled, and Huh7.5/let-7b cells. The results of in silico analysis and dual-luciferase reporter assay exhibited a specific interaction of HCV-NS5B and let-7b. Real-time PCR analysis revealed that in contrast to infected naïve Huh7.5 cells and Huh7.5/scrambled, a significant decrease in HCV-RNA load was seen in Huh7.5/let-7b cells. On the other hand, the Flow Cytometry test showed that let-7b could significantly induce the apoptosis pathway in Huh7.5/let-7b.

CONCLUSIONS

The results also suggest that let-7b, as a target of the HCV genome, potentially reduces HCV replication and raises cell apoptosis rate. We suggest that let-7b directly downregulates HCV replication and may serve as a unique antiviral therapy.

Lin28a attenuates TGF-β-induced renal fibrosis

Lin28a has diverse functions including regulation of cancer, reprogramming and regeneration, but whether it promotes injury or is a protective reaction to renal injury is unknown. We studied how Lin28a acts in unilateral ureteral obstruction (UUO)-induced renal fibrosis following unilateral ureteral obstruction, in a mouse model. We further defined the role of Lin28a in transforming growth factor (TGF)-signaling pathways in renal fibrosis through in vitro study using human tubular epithelium-like HK-2 cells. In the mouse unilateral ureteral obstruction model, obstruction markedly decreased the expression of Lin28a, increased the expression of renal fibrotic markers such as type I collagen, α-SMA, vimentin and fibronectin. In TGF-β-stimulated HK-2 cells, the expression of Lin28a was reduced and the expression of renal fibrotic markers such as type I collagen, α-SMA, vimentin and fibronectin was increased. Adenovirus-mediated overexpression of Lin28a inhibited the expression of TGF-β-stimulated type I collagen, α-SMA, vimentin and fibronectin. Lin28a inhibited TGF-β-stimulated SMAD3 activity, via inhibition of SMAD3 phos-phorylation, but not the MAPK pathway ERK, JNK or p38. Lin28a attenuates renal fibrosis in obstructive nephropathy, making its mechanism a possible therapeutic target for chronic kidney disease.

MicroR-26b Targets High Mobility Group, AT-hook 2 to Ameliorate Myocardial Infarction-induced Fibrosis by Suppression of Cardiac Fibroblasts Activation

BACKGROUND

Myocardial Fibrosis (MF) is an important physiological change after myocardial infarction (MI). MicroRNA-26b (MiR-26b) has a certain inhibitory effect on pulmonary fibrosis. However, the role of miR-26b in MI-induced MF rats and underlying molecular mechanisms remain unknown.

METHODS

Forty male Sprague Dawley (SD) rats weighing 200-250 g were divided into four groups (n=10): Sham group, MF group, MF + negative control (NC) agomir group and MF + miR-26b agomir group. Cardiac fibroblasts were isolated from cardiac tissue. Fibrosis levels were detected by MASSON staining, while the expression of related genes was detected by RT-qPCR, Western blotting and Immunohistochemistry, respectively. TargetScan and dual-luciferase reporter assay were utilized to predict the relationship between miR-26b and high mobility group, AT-hook 2 (HMGA2).

RESULTS

The study found the expression of miR-26b to be down-regulated in the myocardium of MF rats (P<0.01). miR-26b overexpression in vitro significantly reduced the survival rate of cardiac fibroblasts and inhibited the expression of the fibrillar-associated protein (α-SMA alphasmooth muscle actin (α-SMA) and collagen I) (P<0.01). TargetScan indicated that HMGA2 was one of the target genes of miR-26b; dual-luciferase reporter assay further confirmed the targeted regulatory relationship (P<0.01). Moreover, miR-26b overexpression significantly reduced the expression of HMGA2 (P<0.01). Notably, HMGA2 overexpression reversed the inhibitory effect of miR-26b overexpression on cardiac fibroblast viability and the expression of α-SMA and collagen I (P<0.01). Animal experiments further indicated that miR-26b overexpression inhibited MIinduced rat MF by inhibiting the expression of HMGA2 (P<0.05, P<0.01).

CONCLUSION

In short, these findings indicate that miR-26b targets HMGA2 to ameliorate MI-induced fibrosis by suppression of cardiac fibroblasts activation.

The role of let-7b in the inhibition of hepatic stellate cell activation by rSjP40

BACKGROUND

Hepatic stellate cells (HSCs) are one of the main cell types involved in liver fibrosis induced by many factors, including schistosomes. Previous studies in our lab have shown that recombinant P40 protein from Schistosoma japonicum (rSjP40) can inhibit HSC activation in vitro. Let-7b is a member of the let-7 microRNA family and plays an inhibitory role in a variety of diseases and inflammatory conditions. In this study, we investigated the role of let-7b in the inhibition of HSC activation by rSjP40.

METHODS

Expression of let-7b was detected by quantitative real-time PCR. A dual luciferase assay was used to confirm direct interaction between let-7b and collagen I. We also used western blot to assess protein levels of TGFβRI and collagen type I α1 (COL1A1).

RESULTS

We found that rSjP40 up-regulates expression of let-7b in HSCs. Let-7b inhibits collagen I expression by directly targeting the 3'UTR region of the collagen I gene. Furthermore, we discovered that let-7b inhibitor partially restores the loss of collagen I expression caused by rSjP40.

CONCLUSION

Our research clarifies the role of let-7b in the inhibition of HSC activation by rSjP40 and will provide new insights and ideas for the inhibition of HSC activation and treatment of liver fibrosis.

Hepatic stellate cells - from past till present: morphology, human markers, human cell lines, behavior in normal and liver pathology

Hepatic stellate cell (HSC), initially analyzed by von Kupffer, in 1876, revealed to be an extraordinary mesenchymal cell, essential for both hepatocellular function and lesions, being the hallmark of hepatic fibrogenesis and carcinogenesis. Apart from their implications in hepatic injury, HSCs play a vital role in liver development and regeneration, xenobiotic response, intermediate metabolism, and regulation of immune response. In this review, we discuss the current state of knowledge regarding HSCs morphology, human HSCs markers and human HSC cell lines. We also summarize the latest findings concerning their roles in normal and liver pathology, focusing on their impact in fibrogenesis, chronic viral hepatitis and liver tumors.

MicroRNAs as regulators, biomarkers and therapeutic targets in liver diseases

MicroRNAs (miRNAs) are small, non-coding RNAs that post-transcriptionally regulate gene expression by binding to specific mRNA targets and promoting their degradation and/or translational inhibition. miRNAs regulate both physiological and pathological liver functions. Altered expression of miRNAs is associated with liver metabolism dysregulation, liver injury, liver fibrosis and tumour development, making miRNAs attractive therapeutic strategies for the diagnosis and treatment of liver diseases. Here, we review recent advances regarding the regulation and function of miRNAs in liver diseases with a major focus on miRNAs that are specifically expressed or enriched in hepatocytes (miR-122, miR-194/192), neutrophils (miR-223), hepatic stellate cells (miR-29), immune cells (miR-155) and in circulation (miR-21). The functions and target genes of these miRNAs are emphasised in alcohol-associated liver disease, non-alcoholic fatty liver disease, drug-induced liver injury, viral hepatitis and hepatocellular carcinoma, as well liver fibrosis and liver failure. We touch on the roles of miRNAs in intercellular communication between hepatocytes and other types of cells via extracellular vesicles in the pathogenesis of liver diseases. We provide perspective on the application of miRNAs as biomarkers for early diagnosis, prognosis and assessment of liver diseases and discuss the challenges in miRNA-based therapy for liver diseases. Further investigation of miRNAs in the liver will help us better understand the pathogeneses of liver diseases and may identify biomarkers and therapeutic targets for liver diseases in the future.

MicroRNAs in the Pathogenesis of Hepatocellular Carcinoma: A Review

Simple Summary

Hepatocellular carcinoma (HCC) is one of the most frequently occurring cancers, and the prognosis for late-stage HCC remains poor. A better understanding of the pathogenesis of HCC is expected to improve outcomes. MicroRNAs (miRNAs) are small, noncoding, single-stranded RNAs that regulate the expression of various target genes, including those in cancer-associated genomic regions or fragile sites in various human cancers. We summarize the central roles of miRNAs in the pathogenesis of HCC and discuss their potential utility as valuable biomarkers and new therapeutic agents for HCC.

Abstract

Hepatocellular carcinoma (HCC) is the seventh most frequent cancer and the fourth leading cause of cancer mortality worldwide. Despite substantial advances in therapeutic strategies, the prognosis of late-stage HCC remains dismal because of the high recurrence rate. A better understanding of the etiology of HCC is therefore necessary to improve outcomes. MicroRNAs (miRNAs) are small, endogenous, noncoding, single-stranded RNAs that modulate the expression of their target genes at the posttranscriptional and translational levels. Aberrant expression of miRNAs has frequently been detected in cancer-associated genomic regions or fragile sites in various human cancers and has been observed in both HCC cells and tissues. The precise patterns of aberrant miRNA expression differ depending on disease etiology, including various causes of hepatocarcinogenesis, such as viral hepatitis, alcoholic liver disease, or nonalcoholic steatohepatitis. However, little is known about the underlying mechanisms and the association of miRNAs with the pathogenesis of HCC of various etiologies. In the present review, we summarize the key mechanisms of miRNAs in the pathogenesis of HCC and emphasize their potential utility as valuable diagnostic and prognostic biomarkers, as well as innovative therapeutic targets, in HCC diagnosis and treatment.

Transcriptional factor ATF3 promotes liver fibrosis via activating hepatic stellate cells

The excessive accumulation of extracellular matrix (ECM) is a key feature of liver fibrosis and the activated hepatic stellate cells (HSCs) are the major producer of ECM proteins. However, the precise mechanisms and target molecules that are involved in liver fibrosis remain unclear. In this study, we reported that activating transcription factor 3 (ATF3) was over-expressed in mice and human fibrotic livers, in activated HSCs and injured hepatocytes (HCs). Both in vivo and in vitro study have revealed that silencing ATF3 reduced the expression of pro-fibrotic genes and inhibited the activation of HSCs, thus alleviating the extent of liver fibrosis, indicating a potential protective role of ATF3 knockdown. However, ATF3 was not involved in either the apoptosis or proliferation of HCs. In addition, our data illustrated that increased nuclear localization of ATF3 promoted the transcription of fibrogenic genes and lnc-SCARNA10, which functioned as a novel positive regulator of TGF-β signaling in liver fibrogenesis by recruiting SMAD3 to the promoter of these genes. Interestingly, further study also demonstrated that lnc-SCARNA10 promoted the expression of ATF3 in a TGF-β/SMAD3-dependent manner, revealing a TGF-β/ATF3/lnc-SCARNA10 axis that contributed to liver fibrosis by activating HSCs. Taken together, our data provide a molecular mechanism implicating induced ATF3 in liver fibrosis, suggesting that ATF3 may represent a useful target in the development of therapeutic strategies for liver fibrosis.

The Target MicroRNAs and Potential Underlying Mechanisms of Yiqi-Bushen-Tiaozhi Recipe against-Non-Alcoholic Steatohepatitis

MicroRNAs (miRNAs) have emerged as potential therapeutic targets for non-alcoholic fatty liver disease/non-alcoholic steatohepatitis (NAFLD/NASH). Traditional Chineses Medicine (TCM) plays an important role in the prevention or treatment of NAFLD/NASH. However, miRNA targets of TCM against NASH still remain largely unknown. Here, we showed that Yiqi-Bushen-Tiaozhi (YBT) recipe effectively attenuated diet-induced NASH in C57BL/6 mice. To identify the miRNA targets of YBT and understand the potential underlying mechanisms, we performed network pharmacology using miRNA and mRNA deep sequencing data combined with Ingenuity Pathway Analysis (IPA). Mmu-let-7a-5p, mmu-let-7b-5p, mmu-let-7g-3p and mmu-miR-106b-3p were screened as the main targets of YBT. Our results suggested that YBT might alleviate NASH by regulating the expression of these miRNAs that potentially modulate inflammation/immunity and oxidative stress. This study provides useful information for guiding future studies on the mechanism of YBT against NASH by regulating miRNAs.

Molecular and Functional Roles of MicroRNAs in the Progression of Hepatocellular Carcinoma-A Review

Liver cancer is the fourth leading cause of cancer deaths globally, of which hepatocellular carcinoma (HCC) is the major subtype. Viral hepatitis B and C infections, alcohol abuse, and metabolic disorders are multiple risk factors for liver cirrhosis and HCC development. Although great therapeutic advances have been made in recent decades, the prognosis for HCC patients remains poor due to late diagnosis, chemotherapy failure, and frequent recurrence. MicroRNAs (miRNAs) are endogenous, non-coding RNAs that regulate various molecular biological phenomena by suppressing the translation of target messenger RNAs (mRNAs). miRNAs, which often become dysregulated in malignancy, control cell proliferation, migration, invasion, and development in HCC by promoting or suppressing tumors. Exploring the detailed mechanisms underlying miRNA-mediated HCC development and progression can likely improve the outcomes of patients with HCC. This review summarizes the molecular and functional roles of miRNAs in the pathogenesis of HCC. Further, it elucidates the utility of miRNAs as novel biomarkers and therapeutic targets.

Pancreatic circulating tumor cell profiling identifies LIN28B as a metastasis driver and drug target

Pancreatic ductal adenocarcinoma (PDAC) lethality is due to metastatic dissemination. Characterization of rare, heterogeneous circulating tumor cells (CTCs) can provide insight into metastasis and guide development of novel therapies. Using the CTC-iChip to purify CTCs from PDAC patients for RNA-seq characterization, we identify three major correlated gene sets, with stemness genes LIN28B/KLF4, WNT5A, and LGALS3 enriched in each correlated gene set; only LIN28B CTC expression was prognostic. CRISPR knockout of LIN28B-an oncofetal RNA-binding protein exerting diverse effects via negative regulation of let-7 miRNAs and other RNA targets-in cell and animal models confers a less aggressive/metastatic phenotype. This correlates with de-repression of let-7 miRNAs and is mimicked by silencing of downstream let-7 target HMGA2 or chemical inhibition of LIN28B/let-7 binding. Molecular characterization of CTCs provides a unique opportunity to correlated gene set metastatic profiles, identify drivers of dissemination, and develop therapies targeting the "seeds" of metastasis.

Acute alcohol consumption-induced let-7a inhibition exacerbates hepatic apoptosis by regulating Rb1 in mice

Alcohol consumption is a critical risk factor for hepatic pathogenesis, including alcoholic liver diseases (ALD), but implications of alcohol-induced dysregulation of microRNA (miRNA) in ALD pathogenesis are not completely understood. In the present study, C57BL/6J male mice were treated with saline (CON; oral gavage; n = 8) or alcohol (EtOH; 3 g/kg body weight; oral gavage; n = 8) for 7 days. A total of 599 miRNAs and 158 key mRNAs related to fatty liver and hepatotoxicity pathways were assessed in mice liver tissues. The mRNA expression datasets were then utilized to predict interactions with miRNAs that were changed by alcohol consumption. Predicted miRNA-mRNA interactions were validated using in vitro miRNA transfection experiments. The results showed that let-7a was significantly decreased in the EtOH group and Rb1 mRNA was predicted as a target gene. This was further supported by an inverse correlation of RB1 and let-7a expression in mice liver tissue. Additionally, key protein expressions involved in RB1-apoptosis axis [i.e., p73, cleaved CASP-3 (cCASP-3), and cCASP-7] showed a trend of increase in the EtOH mice; this was also confirmed by capase-3 enzyme activity and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay in livers of mice that had consumed alcohol. In line with our in vivo observations, alcohol treatment suppressed the let-7a expression and subsequently upregulated p73, cCASP-3, and cCASP-7 protein expressions in mice hepatocytes. Additional proteins in the apoptosis regulatory pathway (i.e., MDM2-p53 axis) were significantly changed in response to let-7a suppression in the cells. Taken together, the current study provides mechanistic evidence that alcohol consumption-induced let-7a suppression results in the upregulation of RB1, thereby promoting hepatic apoptosis through induction of pro-apoptotic proteins (e.g., p73), and by, at least in part, preventing MDM2-mediated p53 degradation.

The role of microRNAs in the pathogenesis, grading and treatment of hepatic fibrosis in schistosomiasis

Schistosomiasis is a prevalent parasitic disease worldwide. The main pathological changes of hepatosplenic schistosomiasis are hepatic granuloma and fibrosis due to worm eggs. Portal hypertension and ascites induced by hepatic fibrosis are usually the main causes of death in patients with chronic hepatosplenic schistosomiasis. Currently, no effective vaccine exists for preventing schistosome infections. For quite a long time, praziquantel (PZQ) was widely used for the treatment of schistosomiasis and has shown benefit in treating liver fibrosis. However, drug resistance and chemical toxicity from PZQ are being increasingly reported in recent years; therefore, new and effective strategies for treating schistosomiasis-induced hepatic fibrosis are urgently needed. MicroRNA (miRNA), a non-coding RNA, has been proved to be associated with the development of many human diseases, including schistosomiasis. In this review, we present a balanced and comprehensive view of the role of miRNAs in the pathogenesis, grading, and treatment of schistosomiasis-associated hepatic fibrosis. The multiple regulatory roles of miRNAs, such as promoting or inhibiting the development of liver pathology in murine schistosomiasis are also discussed in depth. Additionally, miRNAs may serve as candidate biomarkers for diagnosing liver pathology of schistosomiasis and as novel therapeutic targets for treating schistosomiasis-associated hepatic fibrosis.

Identification of Pparγ-modulated miRNA hubs that target the fibrotic tumor microenvironment

Liver fibrosis interferes with normal organ function and supports tumor development in the liver. We uncovered a role of miRNAs in controlling liver fibrosis. In a comprehensive and systematic analysis we specify miRNA activities in targeting the fibrotic cellular microenvironment of the liver, in both mice and humans. We reveal and validate a complex network of 8 functionally connected miRNAs and 54 target genes to regulate structural, signaling, and remodeling components of the fibrotic extracellular matrix. We identify expression of this miRNA network to be controlled by the transcription factor Pparγ. Thus, we expand the antifibrotic function of Pparγ to controlling the synthesis of an antifibrotic miRNA network. This network may serve as a therapeutic target in antifibrotic therapies.

Liver fibrosis interferes with normal liver function and facilitates hepatocellular carcinoma (HCC) development, representing a major threat to human health. Here, we present a comprehensive perspective of microRNA (miRNA) function on targeting the fibrotic microenvironment. Starting from a murine HCC model, we identify a miRNA network composed of 8 miRNA hubs and 54 target genes. We show that let-7, miR-30, miR-29c, miR-335, and miR-338 (collectively termed antifibrotic microRNAs [AF-miRNAs]) down-regulate key structural, signaling, and remodeling components of the extracellular matrix. During fibrogenic transition, these miRNAs are transcriptionally regulated by the transcription factor Pparγ and thus we identify a role of Pparγ as regulator of a functionally related class of AF-miRNAs. The miRNA network is active in human HCC, breast, and lung carcinomas, as well as in 2 independent mouse liver fibrosis models. Therefore, we identify a miRNA:mRNA network that contributes to formation of fibrosis in tumorous and nontumorous organs of mice and humans.

miRNAs Signatures In Patients With Acute Liver Injury: Clinical Concerns and Correlations

Non-coding RNAs can be highly exploited for their biological significance in living systems. miRNAs are in the upstream position of cellular regulation cascade and hold merit in its state. A plethora of information is available on a wide variety of miRNAs that undergo alterations in experimentally induced models of liver injuries. The underlying mechanisms governed by these miRNAs have been inferred through cellbased experiments but the scientific knowledge on miRNA signatures in patients with liver injury are primordial and lack scientific clarity. Hence, it is crucial to get insight into the status and synergy of miRNAs in patients, with varying degrees of acute toxic manifestations in the liver. Though some miRNAs are being investigated in clinical trials, a major research lacuna exists with regard to the functional role of other miRNAs in liver diseases. This review article is a meticulous compilation of disease based or drug/alcohol based acute liver injuries in patients and resultant alteration in their miRNA profile. Investigative reports on underlying miRNA-liver crosstalk in cell-based or murine models are also discussed herein to draw a correlation with clinical findings.

MicroRNA‑379‑5p suppresses renal fibrosis by regulating the LIN28/let‑7 axis in diabetic nephropathy

MicroRNAs (miRNAs or miRs) play an important role in pathological processes in diabetic nephropathy (DN). This study aimed to explore whether miR‑379‑5p is associated with renal fibrosis in DN and to elucidate the underlying mechanisms. In vitro experiments indicated that miR‑379‑5p expression was downregulated by high glucose (HG) treatment in mouse mesangial cells (MMCs). Transfection with miR‑379‑5p mimics suppressed the proliferation and the accumulation of extracellular matrix (ECM) components, which were promoted by HG treatment. LIN28B was proven to be a direct target of miR‑379‑5p by luciferase report assay. In addition, the loss of expression of LIN28B, as well as the decrease in cell proliferation and in the accumulation of ECM components, which were induced by the knockdown of LIN28B, were attenuated in the MMCs following transfection with miR‑379‑5p inhibitors. Furthermore, type 2 diabetic db/db mice were used to examine the efficiency of miR‑379‑5p agomir in the alleviation of renal fibrosis. Consistent with the results of the in vitro experiments, miR‑379‑5p agomir suppressed mesangial cell proliferation and the accumulation of ECM components by regulating the LIN28B/let‑7 pathway. Taken together, the findings of this study suggest that miR‑379‑5p is highly involved in renal fibrosis in DN, and that it may be a potential effective therapeutic target for DN.

Microarray profiling identifies extracellular circulating miRNAs dysregulated in cystic fibrosis

Extracellular circulating miRNAs (ECmiRNAs) play a crucial role in cell-to-cell communication and serve as non-invasive biomarkers in a wide range of diseases, but their abundance and functional relevance in cystic fibrosis (CF) remain poorly understood. In this study, we employed microarray technology to identify aberrantly expressed plasma ECmiRNAs in CF and elucidate the functional relevance of their targets. Overall, we captured several ECmiRNAs abundantly expressed in CF. Expression levels of 11 ECmiRNAs differed significantly between CF and healthy control (HC) samples (FDR < 0.05, log2 FC≥2). Among these, 10 were overexpressed while only hsa-miR-598-3p was underexpressed in CF. The overexpressed miRNAs included three let-7 family members (hsa-let-7b-5p, hsa-let-7c-5p and hsa-let-7d-5p), three 103/107 family members (hsa-mir-103a-3p; hsa-mir-103b; hsa-mir-107), hsa-miR-486-5p, and other miRNAs. Using in silico methods, we identified 2,505 validated targets of the 11 differentially expressed miRNAs. Hsa-let-7b-5p was the most important hub in the network analysis. The top-ranked validated targets were involved in miRNA biogenesis and gene expression, including AGO1, DICER1, HMGA1, and MYC. The top pathways influenced by all targets were primarily signal transduction pathways associated with CF, including PI3K/Akt-, Wnt/β catenin-, glucocorticoid receptor-, and mTor signaling pathways. Our results suggest ECmiRNAs may be clinically relevant in CF and warrant further study.

Noncoding RNAs in alcoholic liver disease

Alcoholic liver disease (ALD) is a complex process with high morbitity and can cause liver dysfunction, which contains a wide spectrum of hepatic lesions, including steatohepatitis, fibrosis, cirrhosis, and eventually hepatocellular carcinoma. To date, the molecular mechanisms for ALD have not been fully explored and an effective therapy is still missing. Overwhelming evidence shows dysregulation of noncoding RNAs (ncRNAs), particularly microRNAs (miRNAs), is correlated with etiopathogenesis and progress of ALD including hepatocyte damage, disrupted lipid metabolism, aggressive inflammatory responses, oxidative stress, programmed cell death, fibrosis, and epigenetic changes induced by alcohol. For example, circulating miRNA-122 is a marker of hepatocyte damage, and miRNA-155 is a potential marker of inflammation, indicating their diagnosis therapeutic potential in ALD. In addition, roles for long noncoding RNAs (lncRNAs) and circular RNAs in ALD are being uncovered. Further, circulating ncRNAs and exosome-derived ncRNAs have attracted more attention lately, suggesting a role in the prevention and treatment of ALD. This review covers the roles of ncRNAs in ALD, and the potential uses as markers for diagnosis and therapeutic options.

Amelioration of Ductular Reaction by Stem Cell Derived Extracellular Vesicles in MDR2 Knockout Mice via Lethal-7 microRNA

Cholangiopathies are diseases that affect cholangiocytes, the cells lining the biliary tract. Liver stem cells (LSCs) are able to differentiate into all cells of the liver and possibly influence the surrounding liver tissue by secretion of signaling molecules. One way in which cells can interact is through secretion of extracellular vesicles (EVs), which are small membrane-bound vesicles that contain proteins, microRNAs (miRNAs), and cytokines. We evaluated the contents of liver stem cell-derived EVs (LSCEVs), compared their miRNA contents to those of EVs isolated from hepatocytes, and evaluated the downstream targets of these miRNAs. We finally evaluated the crosstalk among LSCs, cholangiocytes, and human hepatic stellate cells (HSCs). We showed that LSCEVs were able to reduce ductular reaction and biliary fibrosis in multidrug resistance protein 2 (MDR2)-/- mice. Additionally, we showed that cholangiocyte growth was reduced and HSCs were deactivated in LSCEV-treated mice. Evaluation of LSCEV contents compared with EVs derived from hepatocytes showed a large increase in the miRNA, lethal-7 (let-7). Further evaluation of let-7 in MDR2-/- mice and human primary sclerosing cholangitis samples showed reduced levels of let-7 compared with controls. In liver tissues and isolated cholangiocytes, downstream targets of let-7 (identified by ingenuity pathway analysis), Lin28a (Lin28 homolog A), Lin28b (Lin28 homolog B), IL-13 (interleukin 13), NR1H4 (nuclear receptor subfamily 1 group H member 4) and NF-κB (nuclear factor kappa B), are elevated in MDR2-/- mice, but treatment with LSCEVs reduced levels of these mediators of ductular reaction and biliary fibrosis through the inhibition of NF-κB and IL-13 signaling pathways. Evaluation of crosstalk using cholangiocyte supernatants from LSCEV-treated cells on cultured HSCs showed that HSCs had reduced levels of fibrosis and increased senescence. Conclusion: Our studies indicate that LSCEVs could be a possible treatment for cholangiopathies or could be used for target validation for future therapies.

Preclinical insights into cholangiopathies: disease modeling and emerging therapeutic targets

INTRODUCTION

The common predominant clinical features of cholangiopathies such as primary sclerosing cholangitis (PSC), primary biliary cholangitis (PBC), and biliary atresia (BA) are biliary damage/senescence and liver fibrosis. Curative therapies are lacking, and liver transplantation is the only option. An understanding of the mechanisms and pathogenesis is needed to develop novel therapies. Previous studies have developed various disease-based research models and have identified candidate therapeutic targets. Areas covered: This review summarizes recent studies performed in preclinical models of cholangiopathies and the current understanding of the pathophysiology representing potential targets for novel therapies. A literature search was conducted in PubMed using the combination of the searched term 'cholangiopathies' with one or two keywords including 'model', 'cholangiocyte', 'animal', or 'fibrosis'. Papers published within five years were obtained. Expert opinion: Access to appropriate research models is a key challenge in cholangiopathy research; establishing more appropriate models for PBC is an important goal. Several preclinical studies have demonstrated promising results and have led to novel therapeutic approaches, especially for PSC. Further studies on the pathophysiology of PBC and BA are necessary to identify candidate targets. Innovative therapeutic approaches such as stem cell transplantation have been introduced, and those therapies could be applied to PSC, PBC, and BA.

Circulating let-7 Levels in Serum Correlate With the Severity of Hepatic Fibrosis in Chronic Hepatitis C

BACKGROUND

Evaluating the progression of hepatic fibrosis in chronic hepatitis C (CHC) is critical, and identifying a predictive biomarker for fibrosis will be helpful for implementing personalized surveillance of hepatocellular carcinoma after the elimination of hepatitis C virus by antiviral therapy. This study aimed to investigate the association of circulating let-7a-5p levels with severity of hepatic fibrosis.

METHODS

We analyzed circulating let-7a-5p levels in serum and serum-derived extracellular vesicles (EVs) in 84 Japanese CHC patients who underwent a liver biopsy by quantitative real-time polymerase chain reaction, and investigated the association of its levels with histological hepatic fibrotic stage, liver stiffness, and several hepatic fibrotic markers.

RESULTS

The levels of let-7a-5p in serum and EVs were significantly lower in patients with liver cirrhosis. Additionally, the serum let-7a-5p level correlated significantly with hepatic fibrotic markers, Mac-2 binding protein glycan isomer (M2BPGi), fibrosis-4 (FIB-4) index, aspartate aminotransferase-to-platelet ratio index (APRI), and liver stiffness, evaluated by transient elastography. Furthermore, the serum let-7a-5p level was superior to M2BPGi, FIB-4, and APRI and was comparable to liver stiffness in discriminating liver cirrhosis.

CONCLUSIONS

These results provide evidence that circulating let-7a-5p in serum may serve as a surrogate marker for severity of hepatic fibrosis in CHC.

Adiponectin inhibits hepatic stellate cell activation by targeting the PTEN/AKT pathway

Adiponectin inhibits hepatic stellate cell (HSC) activation and subsequent development of liver fibrosis via multiple mechanisms. Phosphatase and tensin homolog deletion 10 (PTEN) plays a crucial role in suppression of HSC activation, but its regulation by adiponectin is not fully understood. Here, we investigated the effect of adiponectin on PTEN in LX-2 cells, a human cell line and examined the underlying molecular mechanisms involved in adiponectin-mediated upregulation of PTEN activity during fibrosis. PTEN expression was found to be significantly reduced in the livers of mice treated with CCl4, whereas its expression was rescued by adiponectin treatment. The DNA methylation proteins DNMT1, DNMT3A, and DNMT3B are all highly expressed in activated primary HSCs compared to quiescent HSCs, and thus represent additional regulatory targets during liver fibrogenesis. Expression of DNMT proteins was significantly induced in the presence of fibrotic stimuli; however, only DNMT3B expression was reduced in the presence of adiponectin. Adiponectin-induced suppression of DNMT3B was found to be mediated by enhanced miR-29b expression. Furthermore, PTEN expression was significantly increased by overexpression of miR-29b, whereas its expression was markedly reduced by a miR-29b inhibitor in LX-2 cells. These findings suggest that adiponectin-induced upregulation of miR-29b can suppress DNMT3B transcription in LX-2 cells, thus resulting in reduced methylation of PTEN CpG islands and ultimately suppressing the PI3K/AKT pathway. Together, these data suggest a possible new explanation for the inhibitory effect of adiponectin on HSC activation and liver fibrogenesis.

Role of microRNAs in alcohol-induced liver disorders and non-alcoholic fatty liver disease

MicroRNAs (miRNAs) are small non-coding RNAs that regulate multiple physiological and pathological functions through the modulation of gene expression at the post-transcriptional level. Accumulating evidence has established a role for miRNAs in the development and pathogenesis of liver disease. Specifically, a large number of studies have assessed the role of miRNAs in alcoholic liver disease (ALD) and non-alcoholic fatty liver disease (NAFLD), two diseases that share common underlying mechanisms and pathological characteristics. The purpose of the current review is to summarize and update the body of literature investigating the role of miRNAs in liver disease. In addition, the potential use of miRNAs as biomarkers and/or therapeutic targets is discussed. Among all miRNAs analyzed, miR-34a, miR-122 and miR-155 are most involved in the pathogenesis of NAFLD. Of note, these three miRNAs have also been implicated in ALD, reinforcing a common disease mechanism between these two entities and the pleiotropic effects of specific miRNAs. Currently, no single miRNA or panel of miRNAs has been identified for the detection of, or staging of ALD or NAFLD. While promising results have been shown in murine models, no therapeutic based-miRNA agents have been developed for use in humans with liver disease.

Role of hepatic stellate cell (HSC)-derived cytokines in hepatic inflammation and immunity

In their quiescent state, Hepatic stellate cells (HSCs), are present in the sub-endothelial space of Disse and have minimal interaction with immune cells. However, upon activation following injury, HSCs directly or indirectly interact with various immune cells that enter the space of Disse and thereby regulate diverse hepatic function and immune physiology. Other than the normal physiological functions of HSCs such as hepatic homeostasis, maturation and differentiation, they also participate in hepatic inflammation by releasing a battery of inflammatory cytokines and chemokines and interacting with other liver cells. Here, we have reviewed the role of HSC in the pathogenesis of liver inflammation and some infectious diseases in order to understand how the interplay between immune cells and HSCs regulates the overall outcome and disease pathology.

RNA-binding protein Lin28 is associated with injured dentin-dental pulp complex in Sprague-Dawley rats

Reactivation of Lin28 accelerates hair, cartilage, bone and mesenchyme regrowth after ear and digit injuries. However, the relationship of Lin28 to reparative dentin has been under investigation. The aim of the present study was to examine whether Lin28 participates in the reparative dentin process and lipopolysaccharide (LPS)-stimulated human dental pulp cells (HDPCs) and to identify the underlying signaling pathway mechanisms. The study established a wound-healing model of the dentin-dental pulp complex in vivo and LPS-induced dental pulp cell inflammation in vitro. In vivo, the results of hematoxylin and eosin staining demonstrated the obvious appearance of reparative dentin and odontoblast-like cells were arranged along the reparative dentin. Immunohistochemical examination demonstrated that Lin28 expression was increased by 72 h after cavity preparation but was decreased by 21 d after cavity preparation. In vitro, HDPCs were exposed to 100 ng/ml LPS for 24 h, and the expression of Lin28 was increased. Overexpression of Lin28 was associated with the downregulated expression of let-7b, let-7g and miR-98. These findings suggest that the wound-healing model was successfully established. Lin28 was involved in the reparative process of the dentin-dental pulp complex and HDPCs exposed to LPS, and Lin28/let-7 may be the underlying mechanism.

Knockout of microRNA-21 attenuates alcoholic hepatitis through the VHL/NF-κB signaling pathway in hepatic stellate cells

microRNA-21 (miRNA) is one of the most abundant miRNAs in chronic liver injuries including alcoholic liver injury. Previous studies have demonstrated that miR-21 plays a role in inflammation in the liver and functions in hepatic stellate cells (HSCs), which reside in the perisinusoidal space between sinusoidal endothelial cells and hepatocytes and regulate sinusoidal circulation. HSCs integrate cytokine-mediated inflammatory responses in the sinusoids and relay them to the liver parenchyma. Here, we showed that the activation of Von Hippel-Lindau (VHL) expression, by miR-21 knockout in vivo and anti-miR-21 or VHL overexpression in vitro, suppressed the production of proinflammatory cytokines, such as interleukin (IL)-6, monocyte chemoattractant protein-1, and IL-1β, in human HSCs during alcoholic liver injury. Sequence and functional analyses confirmed that miR-21 directly targeted the 3'-untranslated region of VHL. Immunofluorescence and real-time PCR analysis revealed that miR-21 depletion blocked NF-κB activation in human HSCs both in cultured HSCs as well as HSCs isolated from alcohol-related liver disease mice liver by laser capture microdissection. We also showed that conditioned medium from anti-miR-21-transfected HSCs suppressed human monocyte-derived THP-1 cell migration. Taken together, our study indicates that depletion of miR-21 may downregulate cytokine production in HSCs and macrophage chemotaxis during alcoholic liver injury and that the targeting of miR-21 may have therapeutic potential for preventing the progression of alcoholic liver diseases. NEW & NOTEWORTHY This study demonstrates that silencing microRNA-21 can inhibit cytokine production and inflammatory responses in human hepatic stellate cells during alcoholic liver injury and that the targeting of microR-21 in hepatic stellate cells may have therapeutic potential for prevention and treatment of alcoholic liver diseases.

Activation of ferritinophagy is required for the RNA-binding protein ELAVL1/HuR to regulate ferroptosis in hepatic stellate cells

Ferroptosis is a recently recognized form of regulated cell death that is characterized by lipid peroxidation. However, the molecular mechanisms regulating ferroptosis are largely unknown. In this study, we report that the RNA-binding protein ELAVL1/HuR plays a crucial role in regulating ferroptosis in liver fibrosis. Upon exposure to ferroptosis-inducing compounds, ELAVL1 protein expression was remarkably increased through the inhibition of the ubiquitin-proteasome pathway. ELAVL1 siRNA led to ferroptosis resistance, whereas ELAVL1 plasmid contributed to classical ferroptotic events. Interestingly, upregulated ELAVL1 expression also appeared to increase autophagosome generation and macroautophagic/autophagic flux, which was the underlying mechanism for ELAVL1-enhanced ferroptosis. Autophagy depletion completely impaired ELAVL1-mediated ferroptotic events, whereas autophagy induction showed a synergistic effect with ELAVL1. Importantly, ELAVL1 promoted autophagy activation via binding to the AU-rich elements within the F3 of the 3'-untranslated region of BECN1/Beclin1 mRNA. The internal deletion of the F3 region abrogated the ELAVL1-mediated BECN1 mRNA stability, and, in turn, prevented ELAVL1-enhanced ferroptosis. In mice, treatment with sorafenib alleviated murine liver fibrosis by inducing hepatic stellate cell (HSC) ferroptosis. HSC-specific knockdown of ELAVL1 impaired sorafenib-induced HSC ferroptosis in murine liver fibrosis. Noteworthy, we retrospectively analyzed the effect of sorafenib on HSC ferroptosis in advanced fibrotic patients with hepatocellular carcinoma receiving sorafenib monotherapy. Attractively, ELAVL1 upregulation, ferritinophagy activation, and ferroptosis induction occurred in primary human HSCs from the collected human liver tissue. Overall, these results reveal novel molecular mechanisms and signaling pathways of ferroptosis, and also identify ELAVL1-autophagy-dependent ferroptosis as a potential target for the treatment of liver fibrosis. Abbreviations: ACTA2/alpha-SMA: actin, alpha 2, smooth muscle, aorta; ACTB/beta-actin: actin beta; ARE: AU-rich element; ATG: autophagy related; BDL: bile duct ligation; BECN1: beclin 1; BSO: buthionine sulfoximine; COL1A1: collagen type I alpha 1 chain; ELAVL1/HuR: ELAV like RNA binding protein 1; FDA: fluorescein diacetate; FTH1: ferritin heavy chain 1; GOT1/AST: glutamic-oxaloacetic transaminase 1; GPT/ALT: glutamic-pyruvic transaminase; GPX4: glutathione peroxidase 4; GSH: glutathione; HCC: hepatocellular carcinoma; HSC: hepatic stellate cell; LCM: laser capture microdissection; MAP1LC3B: microtubule associated protein 1 light chain 3 beta; MDA: malondialdehydep; NCOA4: nuclear receptor coactivator 4; PTGS2: prostaglandin-endoperoxide synthase 2; ROS: reactive oxygen species; SQSTM1/p62: sequestosome 1; TBIL: total bilirubin; TEM: transmission electron microscopy; TGFB1: trasforming growth factor beta 1; UTR: untranslated region; VA-Lip-ELAVL1-siRNA: vitamin A-coupled liposomes carrying ELAVL1-siRNA.