MicroRNA-101 suppresses liver fibrosis by targeting the TGFβ signalling pathway

The role of lncRNA-mediated ceRNA regulatory networks in liver fibrosis

In the dynamic realm of molecular biology and biomedical research, the significance of long non-coding RNAs (lncRNAs) acting as competing endogenous RNAs (ceRNAs) continues to grow, encompassing a broad spectrum of both physiological and pathological conditions. Particularly noteworthy is their pivotal role in the intricate series of events leading to the development of hepatic fibrosis, where hepatic stellate cells (HSCs) play a central role. Recent strides in scientific exploration have unveiled the intricate involvement of lncRNAs as ceRNAs in orchestrating the activation of HSCs. This not only deepens our comprehension of the functioning of proteins, DNA, and the extensive array of coding and noncoding RNAs but also sheds light on the intricate molecular interactions among these molecules. Furthermore, the well-established ceRNA networks, involving classical interactions between lncRNAs, microRNAs (miRNAs), and messenger RNAs (mRNAs), are not mere bystanders; they actively participate in instigating and advancing liver fibrosis. This underscores the pressing need for additional thorough research to fully grasp the potential of ceRNA. The unyielding pursuit of knowledge in this field remains a potent driving force with the capacity to enhance the quality of life for numerous individuals grappling with such diseases. It holds the promise of ushering in a new era of precision medicine, signifying a relentless dedication to unraveling the intricacies of molecular interactions that could pave the way for transformative advancements in the diagnosis and treatment of hepatic fibrosis.

The increase of long noncoding RNA Fendrr in hepatocytes contributes to liver fibrosis by promoting IL-6 production

Liver fibrosis/cirrhosis is a pathological state caused by excessive extracellular matrix deposition. Sustained activation of hepatic stellate cells (HSC) is the predominant cause of liver fibrosis, but the detailed mechanism is far from clear. In this study, we found that long noncoding RNA Fendrr is exclusively increased in hepatocytes in the murine model of CCl4- and bile duct ligation-induced liver fibrosis, as well as in the biopsies of liver cirrhosis patients. In vivo, ectopic expression of Fendrr aggravated the severity of CCl4-induced liver fibrosis in mice. In contrast, inhibiting Fendrr blockaded the activation of HSC and ameliorated CCl4-induced liver fibrosis. Our mechanistic study showed that Fendrr binds to STAT2 and enhances its enrichment in the nucleus, which then promote the expression of interleukin 6 (IL-6), and, ultimately, activates HSC in a paracrine manner. Accordingly, disrupting the interaction between Fendrr and STAT2 by ectopic expression of a STAT2 mutant attenuated the profibrotic response inspired by Fendrr in the CCl4-induced liver fibrosis. Notably, the increase of Fendrr in patient fibrotic liver is positively correlated with the severity of fibrosis and the expression of IL-6. Meanwhile, hepatic IL-6 positively correlates with the extent of liver fibrosis and HSC activation as well, thus suggesting a causative role of Fendrr in HSC activation and liver fibrosis. In conclusion, these observations identify an important regulatory cross talk between hepatocyte Fendrr and HSC activation in the progression of liver fibrosis, which might represent a potential strategy for therapeutic intervention.

miR-324-3p Suppresses Hepatic Stellate Cell Activation and Hepatic Fibrosis Via Regulating SMAD4 Signaling Pathway

In hepatic fibrosis (HF), hepatic stellate cells (HSCs) form the extracellular matrix (ECM), and the pathological accumulation of ECM in the liver leads to inflammation. Our previous research found that miR-324-3p was down-regulated in culture-activated human HSCs. However, the precise effect of miR-324-3p on HF has not been elucidated. In this study, the HF mouse models were induced through directly injecting carbon tetrachloride (CCl4) into mice; the HF cell models were constructed using TGF-β1-treated LX-2 cells. Next, real-time-quantitative polymerase chain reaction (RT-qPCR), western blot (WB) and immunohistochemistry (IHC) were applied to assess the expression levels of miR-324-3p, α-smooth muscle actin (α-SMA), Vimentin or SMAD4; hematoxylin and eosin (H&E), Masson' s trichrome and Sirius red staining to evaluate the liver injury; luciferase reporter assay to verify the targeting relationship between miR-324-3p and SMAD4; enzyme-linked immunosorbent assay (ELISA) to determine the levels of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST); and cell counting kit-8 (CCK-8) and flow cytometry to evaluate the effects of miR-324-3p on cell proliferation and cycle/apoptosis, respectively. The experimental results showed a reduction in miR-324-3p level in CCl4-induced HF mice as well as transforming growth factor (TGF)-β1-activated HSCs. Interestingly, the miR-324-3p level was rescued following the HF recovery process. In HF mice induced by CCl4, miR-324-3p overexpression inhibited liver tissue damage, decreased serum ALT and AST levels, and inhibited fibrosis-related biomarkers (α-SMA, Vimentin) expression, thereby inhibiting HF. Similarly, miR-324-3p overexpression up-regulated α-SMA and Vimentin levels in HF cells, while knockdown of miR-324-3p had the opposite effect. Besides, miR-324-3p played an antifibrotic role through inhibiting the proliferation of hepatocytes. Further experiments confirmed that miR-324-3p targeted and down-regulated SMAD4 expression. SMAD4 was highly expressed in HF cells, and silencing SMAD4 significantly decreased the α-SMA and Vimentin levels in HF cells. Collectively, the miR-324-3p may suppress the activation of HSCs and HF by targeting SMAD4. Therefore, miR-324-3p is identified as a potential and novel therapeutic target for HF.

RNA nanomedicine in liver diseases

The remarkable impact of RNA nanomedicine during the COVID-19 pandemic has demonstrated the expansive therapeutic potential of this field in diverse disease contexts. In recent years, RNA nanomedicine targeting the liver has been paradigm-shifting in the management of metabolic diseases such as hyperoxaluria and amyloidosis. RNA nanomedicine has significant potential in the management of liver diseases, where optimal management would benefit from targeted delivery, doses titrated to liver metabolism, and personalized therapy based on the specific site of interest. In this review, we discuss in-depth the different types of RNA and nanocarriers used for liver targeting along with their specific applications in metabolic dysfunction-associated steatotic liver disease, liver fibrosis, and liver cancers. We further highlight the strategies for cell-specific delivery and future perspectives in this field of research with the emergence of small activating RNA, circular RNA, and RNA base editing approaches.

Downregulation of fibrosis related hsa-miR-29c-3p in human CAKUT

Congenital anomalies of the kidney and urinary tract (CAKUT) represent structural and functional urinary system malformations and take place as one of the most common congenital malformations with an incidence of 1:500. Ureteral obstruction-induced hydronephrosis is associated with renal fibrosis and chronic kidney diseases in the pediatric CAKUT. We aimed to construct interaction network of previously bioinformatically associated miRNAs with CAKUT differentially expressed genes in order to prioritize those associated with fibrotic process and to experimentally validate the expression of selected miRNAs in CAKUT patients compared to control group. We constructed interaction network of hsa-miR-101-3p, hsa-miR-101-5p and hsa-miR-29c-3p that showed significant association with fibrosis. The top enriched molecular pathway was extracellular matrix-receptor interaction (adjusted p = .0000263). We experimentally confirmed expression of three miRNAs (hsa-miR-29c-3p, hsa-miR-101-3p and hsa-miR-101-5p) in obstructed ureters (ureteropelvic junction obstruction and primary obstructive megaureter) and vesicoureteral reflux. The hsa-miR-29c-3p was shown to have lower expression in both patient groups compared to controls. Relative levels of hsa-miR-101-5p and hsa-miR-101-3p showed significant positive correlations in both groups of patients. Statistically significant correlation was observed between hsa-miR-101 (-3p and -5p) and hsa-miR-29c-3p only in the obstructed group. The significant downregulation of anti-fibrotic hsa-miR-29c-3p in obstructive CAKUT could explain activation of genes involved in fibrotic processes. As miRNAs are promising candidates in therapeutic approaches our results need further measurement of fibrotic markers or assessment of extent of fibrosis and functional evaluation of hsa-miR-29c.

Insight into the Inter-Organ Crosstalk and Prognostic Role of Liver-Derived MicroRNAs in Metabolic Disease Progression

Dysfunctional hepatic metabolism has been linked to numerous diseases, including non-alcoholic fatty liver disease, the most common chronic liver disorder worldwide, which can progress to hepatic fibrosis, and is closely associated with insulin resistance and cardiovascular diseases. In addition, the liver secretes a wide array of metabolites, biomolecules, and microRNAs (miRNAs) and many of these secreted factors exert significant effects on metabolic processes both in the liver and in peripheral tissues. In this review, we summarize the involvement of liver-derived miRNAs in biological processes with an emphasis on delineating the communication between the liver and other tissues associated with metabolic disease progression. Furthermore, the review identifies the primary molecular targets by which miRNAs act. These consolidated findings from numerous studies provide insight into the underlying mechanism of various metabolic disease progression and suggest the possibility of using circulatory miRNAs as prognostic predictors and therapeutic targets for improving clinical intervention strategies.

TGF-β3 induces lactate production in Sertoli cell through inhibiting Notch pathway

BACKGROUNDS

In the testis, spermatocytes and spermatids rely on lactate produced by Sertoli cells (SCs) as energy source. TGF-β3 is one of the generally accepted paracrine regulatory factors of SC-created blood-testis barrier (BTB), yet its role in SC glycolysis and lactate production still remains unclear.

OBJECTIVES

To investigate the effect of TGF-β3 on glycolysis and lactate production in SCs and determine the role of Lgl2 and Notch signaling activity during this process.

MATERIALS AND METHODS

Primary cultured rat Sertoli cells and TM4 cells were treated with different concentrations of TGF-β3. In some experiments, cells were transfected with siRNA specifically targeting Lgl2 and then treated with TGF-β3 or DAPT. Lactate concentration, glucose and glutamine consumption in the culture medium, activity of PFK, LDH, and Gls, ATP level, oxygen consumption, extracellular acidification and mitochondrial respiration complex activity were detected using commercial kits. The protein level of Lgl2, LDH, MCT4, and activity of Akt, ERK, p38 MAPK, and Notch pathway were detected by Western blot. The stage-specific expression of Jagged1 was examined by immunohistochemistry and qPCR after LCM. Spermatogenesis in rat testis injected with recombinant Jagged1 (re-Jagged1) was observed by HE staining and lactate concentration in testis lysate was measured at different day point after re-Jagged1 treatment.

RESULTS

Significant enhancement of lactate concentration was detected in culture medium of both primary SCs and TM4 cells treated with TGF-β3 at 3 or 5 ng/ml. Besides, other parameters of glycolysis, i.e. glucose and Gln consumption, enzyme activity of PFK, LDH, and Gls, displayed different levels of increment in primary SCs and TM4 cells after TGF-β3 treatment. Mitochondria respiration of SCs was shown to decrease in response to TGF-β3. Lgl2, MCT4, activity of ERK and p38 MAPK were up-regulated, whereas Akt and Notch pathway activity were inhibited by TGF-β3. Silencing of Lgl2 in SCs affected lactate production and attenuated the above effects of TGF-β3 on SC glycolysis except for Gln consumption, Gls activity, and activity of Akt, ERK, and p38. DAPT treatment in SCs antagonized glycolysis suppression caused by Lgl2-silencing. In vivo analysis revealed a stage-specific expression of Jagged1 in contrary with TGF-β3. Activating Notch signaling by re-Jagged1 resulted in restorable hypospermatogenesis and lowered lactate level in rat testis.

CONCLUSION

TGF-β3 induces lactate production in Sertoli cell through upregulating Lgl2, which weakened the Notch signaling activity and intensified glycolysis in SCs. Thus, besides the known function of TGF-β3 as the BTB regulator, TGF-β3-Lgl2-Notch maybe considered as an important pathway controlling Sertoli cell glycolysis and spermatogenesis. This article is protected by copyright. All rights reserved.

The involvement of microRNAs in HCV and HIV infection

Approximately 2.3 million people are suffering from human immunodeficiency virus (HIV)/hepatitis C virus (HCV) co-infection worldwide. Faster disease progression and increased mortality rates during the HIV/HCV co-infection have become global health concerns. Effective therapeutics against co-infection and complete infection eradication has become a mandatory requirement. The study of small non-coding RNAs in cellular processes and viral infection has so far been beneficial in various terms. Currently, microRNAs are an influential candidate for disease diagnosis and treatment. Dysregulation in miRNA expression can lead to unfavorable outcomes; hence, this exact inevitable nature has made various studies a focal point. A considerable improvement in comprehending HIV and HCV mono-infection pathogenesis is seen using miRNAs. The prominent reason behind HIV/HCV co-infection is seen to be their standard route of transmission, while some pieces of evidence also suspect viral interplay between having a role in increased viral infection. This review highlights the involvement of microRNAs in HIV/HCV co-infection, along with their contribution in HIV mono- and HCV mono-infection. We also discuss miRNAs that carry the potentiality of becoming a biomarker for viral infection and early disease progression.

MicroRNA-15a inhibits hepatic stellate cell activation and proliferation via targeting SRY-box transcription factor 9

Accumulating research have indicated that microRNAs are associated with the progression of hepatic fibrosis (HF). Nevertheless, the biological role and function of microRNA (miR)-15a in HF are still unknown. Our data revealed that miR-15a expression was decreased in TGF-β1-treated LX-2 cells and CCl₄-induced mouse model. Additionally, miR-15a could directly target the 3’‑untranslated region of SRY-box transcription factor 9 (SOX9) to inhibit its expression. miR-15a overexpression attenuated the viability and invasion, but enhanced apoptosis in LX-2 cells. However, miR-15a knockdown had the opposite effects. Interestingly, SOX9 overexpression reversed the changes in cell viability, invasion and apoptosis mediated by miR-15a overexpression. Moreover, the miR-15a overexpression-mediated collagen I and alpha smooth muscle actin (a-SMA) downregulation were reversed by SOX9 overexpression. Overall, miR-15a could inhibit LX-2 cell viability and HF pathogenesis by targeting SOX9 in vitro and in vivo.

Astaxanthin Attenuates the Changes in the Expression of MicroRNAs Involved in the Activation of Hepatic Stellate Cells

We previously demonstrated that astaxanthin (ASTX), a xanthophyll carotenoid, has an antifibrogenic effect in hepatic stellate cells (HSC), primarily responsible for the accumulation of extracellular matrix protein during the development of liver fibrosis. Studies have shown that microRNAs (miRNAs) are involved in HSC activation. Therefore, we analyzed the expression of 84 miRNAs using miRNA arrays in primary mouse quiescent HSC (qHSC) and activated HSC (aHSC) treated with/without ASTX during their activation. Compared with qHSC, the expression of 14 miRNAs and 23 miRNAs was increased and decreased by more than 2-fold, respectively, in aHSC. Among the 14 miRNAs increased in aHSC, the expression of miR-192-5p, miR-382-5p, and miR-874-3p was reduced by ASTX. In addition, ASTX increased the expression of miR-19a-3p, miR-19b-3p, and miR-101a-3p among 23 miRNAs decreased in aHSC. Moreover, we confirmed miR-382-5p expression was ~15-fold higher in aHSC than qHSC, and ASTX markedly inhibited the induction measured by quantitative real-time PCR. We identified that the expression of Baz1a and Zfp462 from the predicted miR-382-5p target genes was significantly reduced in aHSC while increased by ASTX treatment similar to the levels in qHSC. The roles of Baz1a and Zfp462 in HSC activation and the antifibrogenic effect of ASTX need to be further investigated.

Overexpression of miR-101 suppresses collagen synthesis by targeting EZH2 in hypertrophic scar fibroblasts

Background

MicroRNA-101 (miR-101) is a tumor suppressor microRNA (miRNA) and its loss is associated with the occurrence and progression of various diseases. However, the biological function and target of miR-101 in the pathogenesis of hypertrophic scars (HS) remains unknown.

Methods

We harvested HS and paired normal skin (NS) tissue samples from patients and cultured their fibroblasts (HSF and NSF, respectively). We used quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), fluorescence in situ hybridization (FISH), enzyme-linked immunosorbent assays (ELISA) and Western blot analyses to measure mRNA levels and protein expression of miR-101, enhancer of zeste homolog 2 (EZH2), collagen 1 and 3 (Col1 and Col3) and α-smooth muscle actin (α-SMA) in different in vitro conditions. We also used RNA sequencing to evaluate the relevant signaling pathways and bioinformatics analysis and dual-luciferase reporter assays to predict miR-101 targets. We utilized a bleomycin-induced fibrosis mouse model in which we injected miR-101 mimics to evaluate collagen deposition in vivo.

Results

We found low expression of miR-101 in HS and HSF compared to NS and NSF. Overexpressing miR-101 decreased Col1, Col3 and α-SMA expression in HSF. We detected high expression of EZH2 in HS and HSF. Knockdown of EZH2 decreased Col1, Col3 and α-SMA in HSF. Mechanistically, miR-101 targeted the 3′-untranslated region (3′UTR) of EZH2, as indicated by the decreased expression of EZH2. Overexpressing EZH2 rescued miR-101-induced collagen repression. MiR-101 mimics effectively suppressed collagen deposition in the bleomycin-induced fibrosis mouse model.

Conclusions

Our data reveal that miR-101 targets EZH2 in HS collagen production, providing new insight into the pathological mechanisms underlying HS formation.

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.

Preparation and Characterization of Silymarin-Conjugated Gold Nanoparticles with Enhanced Anti-Fibrotic Therapeutic Effects against Hepatic Fibrosis in Rats: Role of MicroRNAs as Molecular Targets

BACKGROUND

The main obstacles of silymarin (SIL) application in liver diseases are its low bioavailability, elevated metabolism, rapid excretion in bile and urine, and inefficient intestinal resorption. The study aimed to synthesize and characterize silymarin-conjugated gold nanoparticles (SGNPs) formulation to improve SIL bioavailability and release for potentiating its antifibrotic action.

METHODS

Both SGNPs and gold nanoparticles (GNPs) were prepared and characterized using standard characterization techniques. The improved formulation was assessed for in vitro drug release study and in vivo study on rats using CCl₄ induced hepatic fibrosis model. SIL, SGNPs, and GNPs were administered by oral gavage daily for 30 days. At the end of the study, rats underwent anesthesia and were sacrificed, serum samples were collected for biochemical analysis. Liver tissues were collected to measure the genes and microRNAs (miRNAs) expressions. Also, histopathological and immunohistochemistry (IHC) examinations of hepatic tissues supported these results.

RESULTS

The successful formation and conjugation of SGNPs were confirmed by measurements methods. The synthesized nanohybrid SGNPs showed significant antifibrotic therapeutic action against CCl₄-induced hepatic damage in rats, and preserved normal body weight, liver weight, liver index values, retained normal hepatic functions, lowered inflammatory markers, declined lipid peroxidation, and activated the antioxidant pathway nuclear factor erythroid-2-related factor 2 (NRF2). The antifibrotic activities of SGNPs mediated through enhancing the hepatic expression of the protective miRNAs; miR-22, miR-29c, and miR-219a which results in suppressed expression of the main fibrosis mediators; TGFβR1, COL3A1, and TGFβR2, respectively. The histopathology and IHC analysis confirmed the anti-fibrotic effects of SGNPs.

CONCLUSIONS

The successful synthesis of SGNPs with sizes ranging from 16 up to 20 nm and entrapment efficiency and loading capacity 96% and 38.69%, respectively. In vivo studies revealed that the obtained nano-formulation of SIL boosted its anti-fibrotic effects.

c-Myc affects hedgehog pathway via KCNQ1OT1/RAC1: A new mechanism for regulating HSC proliferation and epithelial-mesenchymal transition

BACKGROUND

This study aimed to probe into the potential mechanism of KCNQ1OT1 in liver fibrosis.

METHODS

The pathological changes in liver tissues were observed by Masson and hematoxylin-eosin (HE) staining. The proliferation or cell cycle of hepatic stellate cells (HSCs) was analyzed by MTT or flow cytometry. The expressions of epithelial markers E-cadherin, interstitial markers Snail and Vimentin, and hedgehog signaling pathway-related molecules Hhip, Shh, and Gli2 were detected by Western blot. The interaction or binding of c-Myc with the KCNQ1OT1 promoter was analyzed by dual-luciferase reporter gene or Chromatin immunoprecipitation (ChIP)-qPCR, and the interaction between KCNQ1OT1 and RAC1 was assessed by RNA immunoprecipitation and RNA pull-down. Moreover, the stability of RAC1 protein was detected by cycloheximide-chase and ubiquitination.

RESULTS

c-Myc and KCNQ1OT1 were up-regulated in liver fibrosis tissues and cells. After the interference with c-Myc in primary-1-Day HSCs, the down-regulated KCNQ1OT1 restrained HSC proliferation and EMT by down-regulating RAC1 expression and restraining the hedgehog pathway.

CONCLUSION

Our results indicated that the interference with c-Myc down-regulated RAC1 expression and restrained the hedgehog pathway by down-regulating KCNQ1OT1, thus restraining HSC proliferation and EMT in liver fibrosis.

Circular RNAs; powerful microRNA sponges to overcome diabetic nephropathy

Diabetic nephropathy (DN), also known as diabetic kidney disease (DKD), is a drastic renal complication of type 1 and type 2 diabetes mellitus (DM). Poorly controlled DM over the years, may disrupt kidneys' blood vessels, leading to the hypertension (HTN) and DN onset. During DN, kidneys' waste filtering ability becomes disturbed. Being on a healthy lifestyle and controlling both DM and HTN are now the best proceedings to prevent or at least delay DN occurrence. Unfortunately, about one-fourth of diabetic individuals eventually experience the corresponding renal failure, and thus it is critical to discover effective diagnostic biomarkers and therapeutic strategies to combat DN. In the past few years, circular RNAs (circRNAs), as covalently closed endogenous non-coding RNAs (ncRNAs), are believed to affect DN pathogenesis in a positive manner. CircRNAs are able to impact different cellular processes and signaling pathways by targeting biological molecules or various molecular mechanisms. Still, as a key regulatory axis, circRNAs can select miRNAs as their molecular targets, in which they are considered as miRNA sponges. In this way, circRNA-induced suppression of particular miRNAs may prevent from DN progression or promotes the DN elimination. Since the expression of circRNAs has also been reported to be increased in DN-associated cells and tissues, they can be employed as either diagnostic biomarkers or therapeutic targets.

miR-770-5p inhibits the activation of pulmonary fibroblasts and silica-induced pulmonary fibrosis through targeting TGFBR1

Silicosis is a devastating interstitial lung disease arising from long-term exposure to inhalable silica. Regrettably, no therapy currently can effectively reverse the silica-induced fibrotic lesion. Emerging evidence has indicated that the dysregulation of microRNAs is involved in silica-induced pulmonary fibrosis. The aim of this study is to explore the expression pattern and underlying mechanisms of miR-770-5p in silica-induced pulmonary fibrosis. Consistent with our previous miRNA microarray analysis, the results of qRT-PCR showed that miR-770-5p expression was downregulated in silica-induced pulmonary fibrosis in humans and animal models. Administration of miR-770-5p agomir significantly reduced the fibrotic lesions in the lungs of mice exposed to silica dust. MiR-770-5p also exhibited a dramatic reduction in TGF-β1-activated human pulmonary fibroblasts (MRC-5). Transfection of miR-770-5p mimics significantly decreased the viability, migration ability, and S/G0 phase distribution, as well as the expression of fibronectin, collagen I, and α-SMA in TGF-β1-treated MRC-5 cells. Transforming growth factor-β receptor 1 (TGFBR1) was confirmed as a direct target of regulation by miR-770-5p. The expression of TGFBR1 was significantly increased in pulmonary fibrosis. Knockdown of TGFBR1 blocked the transduction of the TGF-β1 signaling pathway and attenuated the activation of MRC-5 cells, while overexpression of TGFBR1 effectively restored the activation of MRC-5 cells inhibited by miR-770-5p. Together, our results demonstrated that miR-770-5p exerted an anti-fibrotic effect in silica-induced pulmonary fibrosis by targeting TGFBR1. Targeting miR-770-5p might provide a new therapeutic strategy to prevent the abnormal activation of pulmonary fibroblasts in silicosis.

MiR-130a-3p Alleviates Liver Fibrosis by Suppressing HSCs Activation and Skewing Macrophage to Ly6Clo Phenotype

Emerging evidences have highlighted the crucial role of microRNAs (miRNAs) in the liver cirrhosis, but the relationship between miR-130a-3p and liver cirrhosis is not entirely clear. As we all know, schistosomiasis, as one of the zoonoses, can lead to liver cirrhosis when it advances. In this study, we investigated the biological functions of miR-130a-3p on the liver fibrosis of schistosomiasis in vivo and in vitro. The mice infected with Schistosoma japonicum (S. japonicum) were treated with lentivirus vector (LV)-miR-130a-3p by hydrodynamic injection through the tail vein. Our findings showed significantly decreased expression of miR-130a-3p both in the serum of patients with cirrhosis and in the liver of mice infected with S. japonicum. The results showed that LV-miR-130a-3p could effectively enter into the liver and alleviate liver granulomatous inflammation and collagen deposition. Simultaneously, LV-miR-130a-3p-promoted macrophages presented the Ly6Clo phenotype, concomitant with the decreased expression of the tissue inhibitor of metalloproteinases (TIMP) 1, and increased the expression of matrix metalloproteinase (MMP) 2, which contributed to the dissolution of collagen. Furthermore, overexpression of miR-130a-3p not only inhibited the activation and proliferation of hepatic stellate cells (HSCs) but also induced the apoptosis of HSCs. In addition, we also confirmed that miR-130a-3p enables to bind with mitogen-activated protein kinase (MAPK) 1 and transforming growth factor-beta receptors (TGFBR) 1 and TGFBR2 genes and inhibit the expressions of these genes. Our findings suggested that miR-130a-3p might represent as the potential candidate biomarker and therapeutic target for the prognosis identification and treatment of schistosomiasis liver fibrosis.

The miR-455-3p/HDAC2 axis plays a pivotal role in the progression and reversal of liver fibrosis and is regulated by epigenetics

Histone deacetylases (HDACs), especially HDAC2, play a role in alleviating liver fibrosis; however, the specific upstream regulation mechanism is unknown. Herein, TargetScan was used to predict the potential upstream targets of HDAC2, and the role of miR-455-3p was explored. The dual luciferase reporter assay showed that miR-455-3p binds to the 3' UTR of HDAC2 mRNA. Additionally, miR-455-3p was downregulated in the liver tissues of patients with cirrhosis and mice with liver fibrosis, as well as in primary HSCs isolated from fibrotic mouse livers and TGF-β-treated LX-2 cells. In contrast, it is highly expressed in the reversal stage of hepatic fibrosis and MDI-cultured LX-2 cells. Our functional analyses showed that miR-455-3p overexpression facilitated apoptosis and reduced the expression of pro-fibrotic markers and the proliferation of activated LX-2 cells. On the contrary, miR-455-3p inhibition converted inactivated LX-2 cells into activated, proliferative, fibrogenic cells. Interestingly, restoration of HDAC2 expression partially blocked the function of miR-455-3p. Downregulated miR-455-3p expression can be restored by DNA methyltransferases in activated LX-2 cells. Methylation-specific PCR, bisulfite sequencing PCR, and chromatin immunoprecipitation assays indicated that the methylation level of miR-455-3p promoter CpG islands was elevated in TGF-β-treated LX-2 cells and that miR-455-3p was downregulated in activated LX-2 cells by DNA hypermethylation, which is mediated by DNMT3b and DNMT1. In conclusion, miR-455-3p acts as a liver fibrosis suppressor by targeting HDAC2, and its deficiency further aggravates the reversal phase of fibrosis. Thus, the epigenetics mediated miR-455-3p/HDAC2 axis may serve as a novel potential therapeutic target for clinical treatment of hepatic fibrosis.

Elevated miR-129-5p attenuates hepatic fibrosis through the NF-κB signaling pathway via PEG3 in a carbon CCl4 rat model

Hepatic fibrosis is a reversible scaring response to chronic liver injury. MicroRNA (miR)-129-5p might regulate fibrosis-related gene expression. This study is performed to decipher, potential of miR-129-5p to influence the progression of hepatic fibrosis in a carbon tetrachloride (CCl4) rat model. Rat hepatic fibrosis was successfully established by subcutaneous injection of 50% CCl4. RT-qPCR revealed that miR-129-5p was poorly expressed and PEG3 was highly expressed in hepatic fibrosis tissues. As reflected by dual-luciferase reporter gene assay, miR-129-5p targeted and reduced the expression of PEG3. Thereafter, miR-129-5p antagomir or short hairpin RNA against paternally expressed gene 3 (PEG3) was adopted for gain- and loss-of-function assay to determine the molecular regulatory mechanism of miR-129-5p. Moreover, we detected the expression of nuclear factor kappa B (NF-κB) signaling pathway-related proteins and apoptosis-related factors, and made a serological analysis of the rat serum samples. Results showed that upregulated miR-129-5p or downregulated PEG3 led to reduction of the histological changes of liver cirrhosis and lowered the apoptosis rate, via downstream effects on the NF-κB signaling pathway. Thus, the hepatic fibrosis induced by CCl4 can be rescued by upregulated miR-129-5p or downregulated PEG3 expression.

MicroRNA‑101 inhibits renal tubular epithelial‑to‑mesenchymal transition by targeting TGF‑β1 type I receptor

MicroRNAs (miRNAs/miRs) are key regulators of renal interstitial fibrosis (RIF). The present study was designed to identify miRNAs associated with the development of RIF, and to explore the ability of these identified miRNAs to modulate the renal tubular epithelial‑to‑mesenchymal transition (EMT) process. To this end, miRNAs that were differentially expressed between normal and fibrotic kidneys in a rat model of mercury chloride (HgCl₂)‑induced RIF were detected via an array‑based approach. Bioinformatics analyses revealed that miR‑101 was the miRNA that was most significantly downregulated in the fibrotic renal tissue samples, and this was confirmed by RT‑qPCR, which also demonstrated that this miRNA was downregulated in transforming growth factor (TGF)‑β1‑treated human proximal tubular epithelial (HK‑2) cells. When miR‑101 was overexpressed, this was sufficient to reverse TGF‑β1‑induced EMT in HK‑2 cells, leading to the upregulation of the epithelial marker, E‑cadherin, and the downregulation of the mesenchymal marker, α‑smooth muscle actin. By contrast, the downregulation of miR‑101 using an inhibitor exerted the opposite effect. The overexpression of miR‑101 also suppressed the expression of the miR‑101 target gene, TGF‑β1 type I receptor (TβR‑I), and thereby impaired TGF‑β1/Smad3 signaling, while the opposite was observed upon miR‑101 inhibition. To further confirm the ability of miR‑101 to modulate EMT, the HK‑2 cells were treated with the TβR‑I inhibitor, SB‑431542, which significantly suppressed TGF‑β1‑induced EMT in these cells. Notably, miR‑101 inhibition exerted a less pronounced effect upon EMT‑related phenotypes in these TβR‑I inhibitor‑treated HK‑2 cells, supporting a model wherein miR‑101 inhibits TGF‑β1‑induced EMT by suppressing TβR‑I expression. On the whole, the present study demonstrates that miR‑101 is capable of inhibiting TGF‑β1‑induced tubular EMT by targeting TβR‑I, suggesting that it may be an important regulator of RIF.

miRNA expression profiles in liver grafts of HCV and HIV/HCV-infected recipients, 6 months after liver transplantation

In hepatitis C virus (HCV)/human immunodeficiency virus (HIV) co‐infected patients, HIV enhances HCV replication and liver damage. Several microRNAs (miRNAs), active in pro‐fibrotic and inflammatory pathways, have been implicated in the pathogenesis of this phenomenon. However, these miRNAs have been tested only in explanted cirrhotic livers, when the liver damage has become chronic and irreversible. No data are available on the early phase of viral infection, such as early after liver transplantation (LT). In the present study, the expression of miR‐101, miR‐122, miR‐155, miR‐192, miR‐200c, miR‐338, and miR‐532 was determined by quantitative real‐time polymerase chain reaction in liver biopsies of HCV (n = 19) and HCV/HIV‐infected (n = 20) LT recipients, as well as in a control group (n = 18) of noninfected patients, transplanted for alcoholic cirrhosis. The timing of liver biopsy was 6 months post‐LT. None of the patients was treated with direct‐acting anti‐HCV drugs. All co‐infected recipients had suppressed HIV viral load. Grading and staging were assessed according to the Ishak Classification. HCV and HIV viral load were measured in the sera. miR‐101 (p = .03), miR‐122 (p = .012), and miR‐192 (p = .038) were significantly downregulated in HCV/HIV co‐infected and HCV mono‐infected recipients when compared with noninfected recipients, and such downregulation was more pronounced in co‐infected ones. Moreover, in co‐infected recipients but not in mono‐infected ones, miR‐101 inversely correlated with the peripheral HCV‐RNA levels (r = .41, p = .04) and miR‐122 inversely correlated with peripheral HCV‐RNA levels (r = .49, p = .03) and with the histological grading (r = .51, p = .02).  In conclusion, as early as 6 months after LT, the presence of HIV‐HCV co‐infection enhanced a significant downregulation of certain miRNAs that showed a direct correlation with HCV viral load and liver inflammation.

Regulatory long non-coding RNAs of hepatic stellate cells in liver fibrosis (Review)

Liver fibrosis (LF) is a continuous wound healing process caused by numerous chronic hepatic diseases and poses a major threat to human health. Activation of hepatic stellate cells (HSCs) is a critical event in the development of hepatic fibrosis. Long non-coding RNAs (lncRNAs) that are involved in HSC activation, participate in the development of LF and are likely to be therapeutic targets for LF. In the present review, the cellular signaling pathways of LF with respect to HSCs were discussed. In particular, this present review highlighted the current knowledge on the role of lncRNAs in activating or inhibiting LF, revealing lncRNAs that are likely to be biomarkers or therapeutic targets for LF. Additional studies should be performed to elucidate the potential of lncRNAs in the diagnosis and prognosis of LF and to provide novel therapeutic approaches for the reversion of LF.

The Gut Microbiota: How Does It Influence the Development and Progression of Liver Diseases

The gut–liver axis plays important roles in both the maintenance of a healthy liver and the pathogenesis of liver diseases, where the gut microbiota acts as a major determinant of this relationship. Gut bacteria-derived metabolites and cellular components are key molecules that affect the function of the liver and modulate the pathology of liver diseases. Accumulating evidence showed that gut microbiota produces a myriad of molecules, including lipopolysaccharide, lipoteichoic acid, peptidoglycan, and DNA, as well as short-chain fatty acids, bile acids, trimethylamine, and indole derivatives. The translocation of these components to the liver exerts beneficial or pathogenic effects by interacting with liver immune cells. This is a bidirectional relationship. Therefore, the existence of crosstalk between the gut and liver and its implications on host health and diseases are essential for the etiology and treatment of diseases. Several mechanisms have been proposed for the pathogenesis of liver diseases, but still, the mechanisms behind the pathogenic role of gut-derived components on liver pathogenesis remain elusive and not understandable. This review discusses the current progress on the gut microbiota and its components in terms of the progression of liver diseases, and in turn, how liver diseases indirectly affect the intestinal function and induce intestinal inflammation. Moreover, this paper highlights the current therapeutic and preventive strategies used to restore the gut microbiota composition and improve host health.

Schisandrin B suppresses liver fibrosis in rats by targeting miR-101-5p through the TGF-β signaling pathway

Schisandrin B (Sch B) and miR-101 family members play critical roles in the pathogenesis of liver fibrosis. However, the relationship between them has not been reported yet. Thus, this study aims to fill this research gap. Results showed that Sch B significantly upregulated the expression of miR-101-5p in HSC-T6 cells. Sch B also increased the expression of miR-101-5p by combined administration of TGF-β1 and Sch B. Using miR-101-5p inhibitor, we demonstrated that Sch B can target miR-101-5p through the TGF-β signalling pathway to regulate the proliferation and activation of HSC-T6 cells. A rat model of carbon tetrachloride-induced liver fibrosis was established, and results indicated that Sch B can attenuate liver fibrosis by upregulating the expression of miR-101-5p. In conclusion, Sch B can directly target miR-101 to suppress liver fibrosis. Sch B or miR-101-5p may be used as a therapeutic approach for the prevention and treatment of liver fibrosis.

A novel identified circular RNA, circ_0000491, aggravates the extracellular matrix of diabetic nephropathy glomerular mesangial cells through suppressing miR‑101b by targeting TGFβRI

Circular RNAs (circRNAs) have crucial roles in various diseases; however, the mechanisms of action underlying circRNAs in the occurrence and development of diabetic nephropathy (DN) remains largely unknown. The present study investigated the differentially expressed circRNAs in the DN mice kidney cortex using circRNA sequencing and elucidated the role of circRNAs in mesangial cells. It was revealed that 40 circRNAs were unconventionally expressed, including 18 upregulated circRNAs and 22 downregulated circRNAs. Furthermore, circ_0000491 levels were significantly augmented in both DN mice and high glucose (HG, 30 mM)-induced mouse mesangial cells (MES13 cells). Knockdown of circ_0000491 significantly suppressed the increase of vimentin, fibronectin and α-smooth muscle actin, as well as collagen type I, III and IV, whilst reversing the decrease of E-cadherin in HG-induced MES13 cells. It was further revealed that circRNA_0000491 sponged miR-101b and that miR-101b directly targets TGFβRI. In addition, the expression levels of miR-101b were negatively associated with the transcriptional level of circRNA_0000491 and miR-101b inhibitors reversed the suppression of extracellular matrix (ECM)-associated protein synthesis mediated by knocking-down circRNA_0000491. In conclusion, the present study investigated the circRNA_0000491/miR-101b/TGFβRI axis in ECM accumulation and fibrosis-associated protein expression levels of mesangial cells, which suggested that circRNA_0000491 may be beneficial for the development of an effective therapeutic target for DN.

MicroRNA interplay between hepatic stellate cell quiescence and activation

Hepatic stellate cells (HSCs) activation play a significant role in the progression of hepatic fibrosis. During chronic liver diseases, hepatocytes are damaged severely and secrete several pro-inflammatory markers and profibrogenic cytokines via modulation of a variety of signaling pathways that are responsible for the activation of HSCs. The microRNAs (miRNA or miR) have the potential to modulate fibrogenic signaling pathways in HSCs. A variety of miRNAs are identified as profibrogenic and are capable of activating HSCs by modulating fibrosis-associated signaling pathways such as transforming growth factor-β/Smad, Wnt/β-catenin, Hedgehog, Snail and Notch in the injured liver. On the other hand, HSCs also have certain antifibrotic miRNAs and these include miR-16, miR-19b, miR-29, miR-30, miR-101, miR-122, miR-133a, miR-144, miR-146a, miR-150-5p, miR-155, miR-195, miR-200a, miR-214, miR-335, miR-370, miR-454, miR-483, etc. are responsible for maintenance of the quiescent phenotype of normal HSCs, apoptosis induction and phenotypic reversion of activated HSCs, inhibition of HSCs proliferation, suppression of the extracellular matrix-associated gene expressions, etc. Thus, understanding of HSCs specific miRNAs regulation may provide new ideas for the targeted therapy of hepatic fibrosis at molecular level in the near future. Therefore, this review focusses on the modulation of miRNAs profile during the HSCs activation in the fibrotic liver.

Upregulated miR-101 inhibits acute kidney injury-chronic kidney disease transition by regulating epithelial-mesenchymal transition

Acute kidney injury (AKI) is an independent risk factor for chronic kidney disease (CKD). However, the role and mechanism of microRNA (miRNA, miR) in AKI-CKD transition are elusive. In this study, a murine model of renal ischemia/reperfusion was established to investigate the repairing effect and mechanism of miR-101a-3p on renal injury. The pathological damage of renal tissue was observed by hematoxylin and eosin and Masson staining. The levels of miR-101, profibrotic cytokines, and epithelial-mesenchymal transition (EMT) markers were analyzed using Western blotting, real-time polymerase chain reaction, and/or immunofluorescence. MiR-101 overexpression caused the downregulation of α-smooth muscle actin, collagen-1, and vimentin, as well as upregulation of E-cadherin, thereby alleviating the degree of renal tissue damage. MiR-101 overexpression mitigated hypoxic HK-2 cell damage. Collagen, type X, alpha 1 and transforming growth factor β receptor 1 levels were downregulated in hypoxic cells transfected with miR-101 mimic. Our study indicates that miR-101 is an anti-EMT miRNA, which provides a novel therapeutic strategy for AKI-CKD transition.

Efficient drug and gene delivery to liver fibrosis: rationale, recent advances, and perspectives

Liver fibrosis results from chronic damages together with an accumulation of extracellular matrix, and no specific medical therapy is approved for that until now. Due to liver metabolic capacity for drugs, the fragility of drugs, and the presence of insurmountable physiological obstacles in the way of targeting, the development of efficient drug delivery systems for anti-fibrotics seems vital. We have explored articles with a different perspective on liver fibrosis over the two decades, then collected and summarized the information by providing corresponding in vitro and in vivo cases. We have discussed the mechanism of hepatic fibrogenesis with different ways of fibrosis induction in animals. Furthermore, the critical chemical and herbal anti-fibrotics, biological molecules such as micro-RNAs, siRNAs, and growth factors, which can affect cell division and differentiation, are mentioned. Likewise, drug and gene delivery and therapeutic systems on in vitro and in vivo models are summarized in the data tables. This review article enlightens recent advances in emerging drugs and nanocarriers and represents perspectives on targeting strategies employed in liver fibrosis treatment.

Twist1-induced miR-199a-3p promotes liver fibrosis by suppressing caveolin-2 and activating TGF-β pathway

The activation of hepatic stellate cells (HSCs) participates in liver fibrosis, and emerging evidences indicate that microRNAs (miRNAs) are abnormally expressed during HSC activation. However, the potential roles of miRNAs in liver fibrosis still remain elusive. Therefore, this study aimed to investigate the role of miR-199a-3p in liver fibrosis and its underlying mechanism. We found that miR-199a-3p expression was dramatically upregulated during HSC activation in vitro, and during liver fibrogenesis in CCl₄-treated rats, and its liver expression was increased in the patients with cirrhosis. By the luciferase assay and RT-qPCR, we revealed that the expression of miR-199a-3p in HSCs was driven by the transcription factor Twist1 which could be further induced by TGF-β treatment. Functional studies showed that inhibition of miR-199a-3p in both human LX2 cells and rat HSCs significantly decreased the expression of fibrotic markers, such as fibronectin and connective tissue growth factor (CTGF), whereas the forced expression of miR-199a-3p exhibited opposite effects, demonstrating the role of miR-199a-3p in promoting HSC activation. Mechanistically, miR-199a-3p plays an important role in TGF-β signalling pathway activation through targeting CAV2 that negatively regulates the expression of transforming growth factor-beta receptor type I (TGFβRI). Importantly, administration of antagomiR-199a-3p in the CCl₄-treated mice significantly ameliorated hepatic fibrosis. In conclusion, Twist1-induced miR-199a-3p mediates the activation of HSCs by suppressing CAV2 expression and subsequently increasing TGFβRI expression to promote TGF-β pathway. Our findings highlight the therapeutic potential of miR-199a-3p for hepatic fibrosis.

Identification lncRNA LOC102551149/miR-23a-5p pathway in hepatic fibrosis

BACKGROUND

Hepatic fibrosis is a worldwide incurable disease; due to the complex and unclear mechanism, there lack the effective therapeutic targets. However, the mechanism of miR-23a-5p underling this pathological process is largely not clear. The purpose of this study was to investigate the role of miR-23a-5p in hepatic fibrosis and HSC activation.

METHODS

The content of miR-23a-5p in hepatic fibrosis induced by N-nitrosodimethylamine (NDMA) and HSC activation induced by platelet-derived growth factor (PDGF) was detected by qRT-PCR. H&E staining, Masson staining and Shear wave electrography (SWE) were used to detect the degree of hepatic fibrosis. Immunohistochemistry staining, qRT-PCR and Western blot detect the related markers of liver fibrosis or HSC activation, as well as the related pathway genes and proteins. Dual-luciferase reporter system verifies the interaction between miR-23a-5p with PTEN or miR-23a-5p with lncRNA LOC102551149 in HSC-T6. siRNA and miRNA mimic transfer to HSC-T6 to detect the function of lncRNA LOC102551149 and miR-23a-5p on HSC activation.

RESULTS

After hepatic fibrosis and HSC activation happened, the expression of miR-23a-5p was up-regulated, whereas anti-miR-23a-5p can alleviate hepatic fibrosis and HSC activation. Further research shows miR-23a-5p can target PTEN and degrade it, causing activation of PI3K/Akt/mTOR/Snail pathway. lncRNA LOC102551149 can be used as a competition endogenous RNA (ceRNA) targeting miR-23a-5p through base pairing, and siRNA LOC102551149 or exogenous miR-23a-5p can induce HSC activation through PI3K/Akt/mTOR/Snail pathway.

CONCLUSION

We demonstrate mechanism pathway of miR-23a-5p on hepatic fibrosis and HSC activation, which may develop a therapeutic target for hepatic fibrosis.

Astragaloside IV protects human cardiomyocytes from hypoxia/reoxygenation injury by regulating miR-101a

Astragaloside IV (AS/IV) is one of the extracted components from the traditional Chinese medicine Astragalus which has been demonstrated to have potential capacity for anti-inflammation activity and for treating cardiovascular disease. Our purpose was to determine the function and underlying molecular mechanism of AS/IV in hypoxia/reoxygenation (H/R) injured in cardiomyocytes. Differentially expressed genes (DEGs) were screened using bioinformatic analysis, and the molecular targeting relationship was verified by the dual-luciferase report system. H/R injured cardiomyocytes were employed to explore the effect of AS/IV. QRT-PCR and Western blot analysis were applied to detect the expression of mRNA and proteins, respectively. Additionally, superoxide dismutase (SOD), lactic dehydrogenase (LDH) and MDA (malondialdehyde) levels were detected to determine the oxidative damage. Cell viability was assessed by CCK-8, and flow cytometry was used to evaluate cell apoptosis ratio. TGFBR1 and TLR2 were selected as DEGs. Additionally, AS/IV could enhance cell proliferation and upregulated miR-101a expression, which suppressed TGFBR1 and TLR2 expression in H/R injured cardiomyocytes. Moreover, the results of Western blot exhibited that the downstream genes (p-ERK and p-p38) in the MAPK signaling pathway were suppressed, which meant AS/IV could inhibit this pathway in H/R injured cardiomyocytes. Overall, this study demonstrated AS/IV could attenuate H/R injury in human cardiomyocytes via the miR-101a/TGFBR1/TLR2/MAPK signaling pathway axis, which means that it could serve as a possible alternate for H/R treatment.

MicroRNA-708 represses hepatic stellate cells activation and proliferation by targeting ZEB1 through Wnt/β-catenin pathway

Liver fibrosis is caused by a sustained wound healing response to chronic liver injury, and the activation of insubstantial hepatic stellate cells (HSCs) is the key process involved. The progression of liver fibrosis may be attenuated by suppressing activation and proliferation of the HSCs. MicroRNA (miRNA) have emerged as major players in governing fundamental biological processes through multiple mechanisms MiR-708 is known to inhibit the development of hepatocellular carcinoma. However, whether miR-708 can function as a transcriptional regulator in liver fibrosis remains unclear. Our study demonstrated that miR-708 expression was inhibited in fibrotic liver tissues and in activated HSCs, accompanied by an increase of the Zinc finger E-box binding homeobox 1 (ZEB1) level. Besides, overexpression of miR-708 and silencing of ZEB1 inhibited the activation and proliferation of LX-2 cells. While knockdown of miR-708 or overexpression of ZEB1 showed reversed results. Further, dual luciferase reporter assays showed that miR-708 directly targeted ZEB1 in vitro. Interestingly, ZEB1 was found to be involved in HSCs by regulating Wnt/β-catenin signaling pathway. Together, our data showed that miR-708 may be a potential therapeutic target in liver fibrosis therapy.

MicroRNA-101 Protects Against Cardiac Remodeling Following Myocardial Infarction via Downregulation of Runt-Related Transcription Factor 1

Background

Myocardial infarction (MI) generally leads to heart failure and sudden death. The hearts of people with MI undergo remodeling with the features of expanded myocardial infarct size and dilated left ventricle. Many microRNAs (miRs) have been revealed to be involved in the remodeling process; however, the participation of miR‐101 remains unknown. Therefore, this study aims to find out the regulatory mechanism of miR‐101 in MI‐induced cardiac remodeling.

Methods and Results

Microarray data analysis was conducted to screen differentially expressed genes in MI. The rat model of MI was established by left coronary artery ligation. In addition, the relationship between miR‐101 and runt‐related transcription factor 1 (RUNX1) was identified using dual luciferase reporter assay. After that, the rats injected with lentiviral vector expressing miR‐101 mimic, inhibitor, or small interfering RNA against RUNX1 were used to examine the effects of miR‐101 and RUNX1 on transforming growth factor β signaling pathway, cardiac function, infarct size, myocardial fibrosis, and cardiomyocyte apoptosis. RUNX1 was highly expressed, while miR‐101 was poorly expressed in MI. miR‐101 was identified to target RUNX1. Following that, it was found that overexpression of miR‐101 or silencing of RUNX1 improved the cardiac function and elevated left ventricular end‐diastolic and end‐systolic diameters. Also, miR‐101 elevation or RUNX1 depletion decreased infarct size, myocardial fibrosis, and cardiomyocyte apoptosis. Moreover, miR‐101 could negatively regulate RUNX1 to inactivate the transforming growth factor β1/Smad family member 2 signaling pathway.

Conclusions

Taken together, miR‐101 plays a protective role against cardiac remodeling following MI via inactivation of the RUNX1‐dependent transforming growth factor β1/Smad family member 2 signaling pathway, proposing miR‐101 and RUNX1 as potential therapeutic targets for MI.

The Regulatory Role of MicroRNA in Hepatitis-B Virus-Associated Hepatocellular Carcinoma (HBV-HCC) Pathogenesis

The incidence and mortality of hepatitis B virus (HBV)-associated hepatocellular carcinoma (HBV-HCC) is an intractable public health problem in developing countries that is compounded by limited early detection and therapeutic options. Despite the early promise of utilizing the regulatory role of miRNA in liver cancer, this field remains largely in the work-in-progress phase. This exploratory review paper adopts a broad focus in order to collate evidence of the regulatory role of miRNA in each stage of the HBV-HCC continuum. This includes the regulatory role of miRNA in early HBV infection, chronic inflammation, fibrosis/cirrhosis, and the onset of HCC. The paper specifically investigates HBV dysregulated miRNA that influence the expression of the host/HBV genome in HBV-HCC pathogenesis and fully acknowledges that this does not cover the full spectrum of dysregulated miRNA. The sheer number of dysregulated miRNA in each phase support a hypothesis that future therapeutic interventions will need to consider incorporating multiple miRNA panels.

mir-101-3p Downregulation Promotes Fibrogenesis by Facilitating Hepatic Stellate Cell Transdifferentiation During Insulin Resistance

Insulin resistance (IR) and microRNAs (miRNAs), which regulate cell-to-cell communication between hepatocytes and hepatic stellate cells (HSCs), may intertwine in nonalcoholic fatty liver disease (NAFLD) pathogenesis. The aim of this study was to evaluate whether epigenetics and environmental factors interact to promote progressive NAFLD during IR. We examined the miRNA signature in insulin receptor haploinsufficient (InsR+/−) and wild-type (wt) HSCs by RNAseq (n = 4 per group). Then, we evaluated their impact in an IR-NASH (nonalcoholic steatohepatitis) model (InsR+/− mice fed standard or methionine choline deficient (MCD) diet, n = 10 per group) and in vitro. InsR+/− HSCs displayed 36 differentially expressed miRNAs (p < 0.05 vs. wt), whose expression was then analyzed in the liver of InsR+/− mice fed an MCD diet. We found that miR-101-3p negatively associated with both InsR+/− genotype and MCD (p < 0.05) and the histological spectrum of liver damage (p < 0.01). miR-101-3p was reduced in InsR+/− hepatocytes and HSCs and even more in InsR+/− cells exposed to insulin (0.33 µM) and fatty acids (0.25 mM), resembling the IR-NASH model. Conversely, insulin induced miR-101-3p expression in wt cells but not in InsR+/− ones (p < 0.05). In conclusion, IR combined with diet-induced liver injury favors miR-101-3p downregulation, which may promote progressive NAFLD through HSC and hepatocyte transdifferentiation and proliferation.

MicroRNA-101 suppresses liver fibrosis by downregulating PI3K/Akt/mTOR signaling pathway

BACKGROUND

MicroRNA-101 (miR-101) is markedly downregulated in both hepatitis B virus-related liver cirrhosis and hepatocellular carcinoma (HCC). In this study, we aimed to investigate the effect and mechanism of miR-101 on hepatic stellate cell (HSC) activation and liver fibrosis.

MATERIALS AND METHODS

HSC LX-2 was treated with TGF-β1 and with or without miR-101 mimics. LX-2 vitality and proliferation, the expression of F-actin and mRNAs for α-SMA, collagen 1α1 (Col 1α1), and connective tissue growth factor 2 (CCN2) were measured. A 6-week intraperitoneal injection of carbon tetrachloride (CCl4) was used to induce experimental liver fibrosis in mice, which were treated using a miR-101 negative control or miR-101 agomir from the fourth week until the end of the experiment. Liver function, hepatic hydroxyproline, liver histopathology, collagen deposition, α-SMA, type I collagen (Col I) and the protein-expressions of p-PI3K, p-Akt and p-mTOR were measured.

RESULTS

MiR-101 significantly suppressed the increased LX-2 vitality and high accumulation of extracellular matrix (ECM) induced by TGF-β1. Exposure to CCl4 led to the impairment of liver function and disruption of normal hepatic parenchyma in mice, as well as obvious liver fibrosis indicated by elevated levels of hydroxyproline, α-SMA, and Col 1α1 in liver tissues. MiR-101 administration significantly improved liver function, relieved hepatic parenchyma damage, and reversed liver fibrosis by decreasing the accumulation of ECM components. Furthermore, miR-101 substantially downregulated the CCl4-increased p-PI3K, p-Akt, and p-mTOR in mouse liver.

CONCLUSIONS

MiR-101 has antifibrotic effects in experimental liver fibrosis, and downregulating the PI3K/Akt/mTOR signaling pathway may be one of its antifibrotic mechanisms.

TGF-β/Smad and Renal Fibrosis

Renal fibrosis is characterized by excessive deposition of extracellular matrix (ECM) that disrupts and replaces functional parenchyma, which leads to organ failure. It is known as the major pathological mechanism of chronic kidney disease (CKD). Although CKD has an impact on no less than 10% of the world population, therapeutic options are still limited. Regardless of etiology, elevated TGF-β levels are highly correlated with the activated pro-fibrotic pathways and disease progression. TGF-β, the key driver of renal fibrosis, is involved in a dynamic pathophysiological process that leads to CKD and end-stage renal disease (ESRD). It is becoming clear that epigenetics regulates renal programming, and therefore, the development and progression of renal disease. Indeed, recent evidence shows TGF-β1/Smad signaling regulates renal fibrosis via epigenetic-correlated mechanisms. This review focuses on the function of TGF-β/Smads in renal fibrogenesis, and the role of epigenetics as a regulator of pro-fibrotic gene expression.

Magnesium isoglycyrrhizinate ameliorates high fructose-induced liver fibrosis in rat by increasing miR-375-3p to suppress JAK2/STAT3 pathway and TGF-β1/Smad signaling

Increasing evidence has demonstrated that excessive fructose intake induces liver fibrosis. Epithelial-mesenchymal transition (EMT) driven by transforming growth factor-β1 (TGF-β1)/mothers against decapentaplegic homolog (Smad) signaling activation promotes the occurrence and development of liver fibrosis. Magnesium isoglycyrrhizinate is clinically used as a hepatoprotective agent to treat liver fibrosis, but its underlying molecular mechanism has not been identified. Using a rat model, we found that high fructose intake reduced microRNA (miR)-375-3p expression and activated the janus-activating kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) cascade and TGF-β1/Smad signaling, which is consistent with the EMT and liver fibrosis. To further verify these observations, BRL-3A cells and/or primary rat hepatocytes were exposed to high fructose and/or transfected with a miR-375-3p mimic or inhibitor or treated with a JAK2 inhibitor, and we found that the low expression of miR-375-3p could induce the JAK2/STAT3 pathway to activate TGF-β1/Smad signaling and promote the EMT. Magnesium isoglycyrrhizinate was found to ameliorate high fructose-induced EMT and liver fibrosis in rats. More importantly, magnesium isoglycyrrhizinate increased miR-375-3p expression to suppress the JAK2/STAT3 pathway and TGF-β1/Smad signaling in these animal and cell models. This study provides evidence showing that magnesium isoglycyrrhizinate attenuates liver fibrosis associated with a high fructose diet.

SCARNA10, a nuclear-retained long non-coding RNA, promotes liver fibrosis and serves as a potential biomarker

Long non-coding RNAs (lncRNAs) are involved in numerous biological functions and pathological processes. However, the clinical significance of lncRNAs and their functions in liver fibrosis remain largely unclear.

Methods: The transcript of lncRNA SCARNA10 in serum and liver samples from patients with advanced hepatic fibrosis, liver tissues from two fibrosis mouse models, and cultured hepatic stellate cells (HSCs) was determined by real-time RT-PCR. The effects of lentivirus-mediated knockdown or over-expression of SCARNA10 in liver fibrosis were examined in vitro and in vivo. Moreover, the effects and mechanisms of down-regulation or over-expression of SCARNA10 on the expression of the genes involved in TGFβ pathway were determined.

Results: It was found lncRNA ENSMUST00000158992, named as Scarna10, was remarkably up-regulated in mouse fibrotic livers according to the microarray data. We observed that the transcript of SCARNA10 was increased in the serum and liver from patients with advanced hepatic fibrosis. Furthermore, we found that SCARNA10 promoted liver fibrosis both in vitro and in vivo through inducing hepatocytes (HCs) apoptosis and HSCs activation. Mechanistically, RNA immunoprecipitation (RIP) assays demonstrated that SCARNA10 physically associated with polycomb repressive complex 2 (PRC2). Additionally, our results demonstrated that SCARNA10 functioned as a novel positive regulator of TGFβ signaling in hepatic fibrogenesis by inhibiting the binding of PRC2 to the promoters of the genes associated with ECM and TGFβ pathway, thus promoting the transcription of these genes.

Conclusions: Our study identified a crucial role of SCARNA10 in liver fibrosis, providing a proof of this molecule as a potential diagnostic marker and a possible therapeutic target against liver fibrosis.

Downregulation of miR-152 contributes to the progression of liver fibrosis via targeting Gli3 in vivo and in vitro

The Gli family is known to be required for the activation of hedgehog signalling, which participates in the pathogenesis of liver fibrosis. The aim of the present study was to identify the association between microRNA (miR)-152 and GLI family zinc finger 3 (Gli3) and their roles in liver fibrosis. In a carbon tetrachloride (CCl₄)-treated rat model, fibrogenesis-associated indexes, including hydroxyproline content, collagen deposition, and α-smooth muscle actin (α-SMA) and albumin expression, were examined in in vivo and in vitro models. The expression of miR-152 and Gli3 in cells and tissues was determined by reverse transcription quantitative polymerase chain reaction and western blot analysis. The interaction of Gli3 and miR-152 was evaluated by bioinformatical analysis and a dual-luciferase reporter assay. The results demonstrated that miR-152 was significantly downregulated in serum samples from clinical patients, liver tissues from CCl₄-treated rats and activated LX2 cells. Furthermore, at the cellular level, the mRNA and protein expression levels of α-SMA and albumin were increased and decreased, respectively, in LX2 cells. Nevertheless, following transfection with an miR-152 mimic, the expression levels of α-SMA and albumin were reversed, and Gli3 expression was notably decreased in LX2 cells. Additionally, the target interaction between miR-152 and Gli3 was demonstrated. Finally, an miR-152 mimic was introduced into the rat model and additionally demonstrated that the changes in α-SMA, albumin and Gli3 expression levels were similar to the expression pattern in LX2 cells following miR-152 mimic transfection. These data provided insight into the potential function of miR-152 as an anti-fibrotic therapy through the modulation of Gli3.

Pterostilbene prevents hepatocyte epithelial-mesenchymal transition in fructose-induced liver fibrosis through suppressing miR-34a/Sirt1/p53 and TGF-β1/Smads signalling

BACKGROUND AND PURPOSE

Excessive fructose consumption is a risk factor for liver fibrosis. Pterostilbene protects against liver fibrosis. Here, we investigated the potential role and the mechanisms underlying the hepatocyte epithelial-mesenchymal transition (EMT) in fructose-induced liver fibrosis and protection by pterostilbene.

EXPERIMENTAL APPROACH

Characteristic features of liver fibrosis in 10% fructose-fed rats and EMT in 5 mM fructose-exposed BRL-3A cells with or without pterostilbene and the change of miR-34a/Sirt1/p53 and transforming growth factor-β1 (TGF-β1)/Smads signalling were examined. MiR-34a inhibitor, miR-34a minic, or p53 siRNA were used to explore the role of miR-34a/Sirt1/p53 signalling in fructose-induced EMT and the action of pterostilbene.

KEY RESULTS

Pterostilbene prevented fructose-induced liver injury with fibrosis in rats. Fructose caused hepatocyte undergoing EMT, gaining fibroblast-specific protein 1 and vimentin, and losing E-cadherin, effects attenuated by pterostilbene. Moreover, fructose induced miR-34a overexpression in hepatocytes with down-regulated Sirt1, increased p53 and ac-p53, and activated TGF-β1/Smads signalling, whereas these disturbances were suppressed by miR-34a inhibitor. Additionally, miR-34a inhibitor and p53 siRNA prevented TGF-β1-driven hepatocyte EMT under fructose exposure. Pterostilbene down-regulated miR-34a, up-regulated Sirt1, and suppressed p53 activation and TGF-β1/Smads signalling in fructose-stimulated animals and cells but showed no additional effects with miR-34a inhibitor on miR-34a/Sirt1/p53 signalling in fructose-exposed hepatocytes.

CONCLUSIONS AND IMPLICATIONS

These results strongly suggest that activation of miR-34a/Sirt1/p53 signalling is required for fructose-induced hepatocyte EMT mediated by TGF-β1/Smads signalling, contributing to liver fibrosis in rats. Pterostilbene exhibits a protective effect against liver fibrosis at least partly through inhibiting miR-34a/Sirt1/p53 signalling activation.

Targeted Drug Delivery to Hepatic Stellate Cells for the Treatment of Liver Fibrosis

Liver fibrosis is caused by excessive accumulation of extracellular matrix during chronic liver injuries. Although clinical evidence suggests that liver fibrosis can be reversed, there is no standard therapy for liver fibrosis. Moreover, there is a lack of diagnostic tools to detect early-stage liver fibrosis. Activation of hepatic stellate cells (HSCs) is the key step during liver fibrogenesis, and its mechanism has been extensively studied by various cell culture and animal models. Targeted delivery of therapeutic agents to activated HSCs is therefore critical for the successful treatment of liver fibrosis. A number of protein markers have been found to be overexpressed in activated HSCs, and their ligands have been used to specifically deliver various antifibrotic agents. In this review, we summarize these HSC-specific protein markers and their ligands for targeted delivery of antifibrotic agents.

Regulatory effect of host miR-101b-3p on parasitism of nematode Angiostrongylus cantonensis via superoxide dismutase 3

MicroRNA plays a vital role in the regulation of host-parasite interaction. In recent years, genomic and transcriptomic resources have become increasingly available for many helminths, but only a limited number of reports in this area are on the regulatory effects of host microRNAs on parasitic nematodes. In this work, we screened increased expression of host microRNAs after nematode infection from miRNA-seq data and predicted target genes by combined bioinformatics analysis and transcriptional profiling. We elucidated regulatory effects of one host miRNA on nematode infection using miRNA inhibitor and adeno-associated virus (AAV)-based TuD miRNA inhibitor. Using AAV-based TuD miRNA inhibitor, we showed that stable blockade of mmu-miR-101b-3p could alleviate the pathological damages of Angiostrongylus cantonensis, a parasitic nematode. Data from a luciferase report assay showed that mmu-miR-101b-3p targeted the extracellular superoxide dismutase 3 (Acsod3). Increased Acsod3 expression in larvae and alleviated oxidative damages were seen in the groups receiving mmu-miR-101b-3p inhibitor treatment in vitro and AAV-based TuD miRNA inhibitor injection in vivo. Results of this study demonstrate that murine miR-101b-3p inhibits the expression of antioxidant enzyme in A. cantonensis to strengthen host oxidative responses to nematodes. This work expands our knowledge of interspecies regulation of nematode gene expression by of host miRNAs.

MiR-146a attenuates liver fibrosis by inhibiting transforming growth factor-β1 mediated epithelial-mesenchymal transition in hepatocytes

Epithelial-mesenchymal transition (EMT) has emerged as a vital process in embryogenesis, carcinogenesis, and tissue fibrosis. Transforming growth factor-beta 1 (TGF-β1)-mediated signaling pathways play important roles in the EMT process. MicroRNA-146a (miR-146a) has been suggested as a significant regulatory molecule in fibrogenesis. Therefore, the present study aimed to evaluate the effect of miR-146a on the EMT of hepatocytes and to investigate the role of overexpressing miR-146a on rat hepatic fibrosis. The results showed that the miR-146a level decreased during the EMT process of L02 hepatocytes induced by TGF-β1 in vitro. Moreover, miR-146a overexpression led to significant reduction of EMT-related markers expression in hepatocytes. Subsequent experiments revealed that miR-146a attenuated the EMT process in hepatocytes by targeting small mothers against decapentaplegic (SMAD) 4. Meanwhile, restoration of SMAD4 expression rescued the inhibitory effect of miRNA-146a on EMT. Further in vivo studies revealed that intravenous injection of miR-146a-expressing adenovirus (Ad-miR-146a) successfully restored the miR-146a levels and mitigated fibrogenesis in the livers of CCl4-treated rats. More importantly, after Ad-miR-146a treatment, inhibition of both EMT traits and SMAD4 expression was observed. The results of the present study showed that miR-146a/SMAD4 is a key signaling cascade that inhibits hepatocyte EMT, and the introduction of miR-146a might present a promising therapeutic option for liver fibrosis.

MicroRNA-101 protects bladder of BOO from hypoxia-induced fibrosis by attenuating TGF-β-smad2/3 signaling

Bladder outlet obstruction is a common disease, which always evokes urinary bladder wall remodeling significantly. It has been suggested that bladder outlet obstruction can make the bladder progression from inflammation to fibrosis, and hypoxia may play a vital role. It has been found the expression of microRNA-101 varied in bladder after BOO. But what role microRNA-101 and hypoxia play in bladder is not well known. This study is to investigate the mechanism of microRNA-101 and hypoxia in fibrosis of bladder after BOO. We found the expression of microRNA-101 and hif-1α increased in bladder after BOO. Hypoxia could promote the expression of extracellular matrix subtypes and microRNA-101 in BSMCs. When microRNA-101b was translated into BSMCs, the smad2/3 signaling pathway was found to repress. Dual luciferase reporter detected that microRNA-101b attenuated the TGF-β signaling pathway by inhibiting the expression of TGFβR1. Then, we conclude microRNA-101b is induced by hypoxia and represses fibrosis of BSMCs by inhibiting the expression of TGFβR1 through TGF-β signaling pathway, and it may be an anti-fibrotic miRNA for therapy. © 2018 IUBMB Life, 71(1):235-243, 2019.

LncRNA-MEG3 inhibits activation of hepatic stellate cells through SMO protein and miR-212

Activation of hepatic stellate cells (HSCs), a pivotal event in liver fibrosis, is considered as an epithelial–mesenchymal transition (EMT) process. Deregulation of long noncoding RNAs (lncRNAs) has been reported to be involved in a series of human diseases. LncRNA-maternally expressed gene 3 (MEG3) functions as a tumor suppressor in cancers and has been shown to play a vital role in EMT process. However, the biological role of MEG3 in liver fibrosis is largely unknown. In this study, MEG3 was reduced in vivo and in vitro during liver fibrosis. Restoring of MEG3 expression led to the suppression of liver fibrosis, with a reduction in α-SMA and type I collagen. Notably, MEG3 overexpression inhibited HSC activation through EMT, associated with an increase in epithelial markers and a reduction in mesenchymal markers. Further studies showed that Hedgehog (Hh) pathway-mediated EMT process was involved in the effects of MEG3 on HSC activation. Smoothened (SMO) is a member of Hh pathway. Using bioinformatic analysis, an interaction between MEG3 and SMO protein was predicted. This interaction was confirmed by the results of RNA immunoprecipitation and deletion-mapping analysis. Furthermore, MEG3 was confirmed as a target of microRNA-212 (miR-212). miR-212 was partly responsible for the effects of MEG3 on EMT process. Interestingly, MEG3 was also reduced in chronic hepatitis B (CHB) patients with liver fibrosis when compared with healthy controls. MEG3 negatively correlated with fibrosis stage in CHB patients. In conclusion, we demonstrate that MEG3 inhibits Hh-mediated EMT process in liver fibrosis via SMO protein and miR-212.

Sphingosine kinase 1 promotes liver fibrosis by preventing miR-19b-3p-mediated inhibition of CCR2

Chronic liver disease mediated by activation of hepatic stellate cells (HSCs) and Kupffer cells (KCs) leads to liver fibrosis. Here, we aimed to investigate the molecular mechanism and define the cell type involved in mediating the sphingosine kinase (SphK)1-dependent effect on liver fibrosis. The levels of expression and activity of SphK1 were significantly increased in fibrotic livers compared with the normal livers in human. SphK1 was coexpressed with a range of HSC/KC markers including desmin, α-smooth muscle actin (α-SMA) and F4/80 in fibrotic liver. Deficiency of SphK1 (SphK1^-/- ) resulted in a marked amelioration of hepatic injury, including transaminase activities, histology, collagen deposition, α-SMA and inflammation, in CCl₄ or bile duct ligation (BDL)-induced mice. Likewise, treatment with a specific inhibitor of SphK1, 5C, also significantly prevented liver injury and fibrosis in mice induced by CCl₄ or BDL. In cellular levels, inhibition of SphK1 significantly blocked the activation and migration of HSCs and KCs. Moreover, SphK1 knockout in KCs reduced the secretion of CCL2, and SphK1 knockout in HSCs reduced C-C motif chemokine receptor 2 ([CCR2] CCL2 receptor) expression in HSCs. CCL2 in SphK1^-/- mice was lower whereas microRNA-19b-3p in SphK1^-/- mice was higher compared with wild-type (WT) mice. Furthermore, microRNA-19b-3p downregulated CCR2 in HSCs. The functional effect of SphK1 in HSCs on liver fibrosis was further strengthened by the results of animal experiments using a bone marrow transplantation (BMT) method.

CONCLUSION

SphK1 has distinct roles in the activation of KCs and HSCs in liver fibrosis. Mechanistically, SphK1 in KCs mediates CCL2 secretion, and SphK1 in HSCs upregulates CCR2 by downregulation of miR-19b-3p. (Hepatology 2018).

MicroRNA-101a suppresses fibrotic programming in isolated cardiac fibroblasts and in vivo fibrosis following trans-aortic constriction

AIMS

MiR-101a is reported to reduce post-infarction myocardial fibrosis through targeting c-FOS and TGFbr1. However the actions of miR-101a within the TGF-β signaling pathway are largely unknown. We demonstrate the mechanisms underlying mutual inhibition between miR-101a and TGF-β signaling and explore the therapeutic potential of miR-101a in suppressing pressure overload-induced cardiac fibrosis.

METHODS AND RESULTS

The effects of miR-101a on fibroblast proliferation, myofibroblast transdifferentiation, collagen synthesis, apoptosis, and autophagy were assessed in isolated rat cardiac fibroblasts (cFB). MiR-101a effects upon cFB TGF-β signaling were assessed by qPCR, Western blotting, 3'UTR luciferase reporter assay and promoter activity assessments. Rats subjected to transverse aortic constriction (TAC) were treated with PBS or 1 mg/kg of a miR-101a mimic i.v. at 1, 3, and 7-day post-surgery. Left ventricular (LV) function (echocardiography; LV catheterization) and LV fibrosis (picro-sirius red staining, qPCR and WB) were assessed at 2-day and 2 & 10-week post-surgery. MiR-101a inhibited cFB proliferation by inducing cell apoptosis rather than through cell cycle inhibition; and reduced collagen synthesis by downregulation of collagen gene expression and increased autophagy. MiR-101a inhibited TGF-β signaling pathways by directly targeting TGFbr1, reducing Smad3 phosphorylation and inhibiting Tab3 promoter activity. Conversely TGF-β inhibited promoter activity for both miR-101a and b. In vivo endogenous miR-101a expression was downregulated 2-day post-TAC returning to baseline by 14-day. MiR-101a mimic treatment inhibited myocardial TGF-β signaling and collagen gene up-regulation at 2-day post-TAC. MiR-101a reduced fibrosis, improved +dP/dt and lowered end diastolic pressure (EDP) at 2-week post-TAC. Treatment also attenuated adverse LV remodeling and preserved cardiac ejection fraction at 10-week post-TAC.

CONCLUSIONS

MiR-101a and TGF-β are mutually inhibitory and co-direct the activation, proliferation, and collagen synthesis of cFBs. The predominance of TGF-β signaling over reduced miR-101a expression early post-TAC is associated with cardiac fibrosis and dysfunction. Treatment with miR-101a, introduced early after imposition of abnormal pressure loading, inhibits TGF-β signaling, reduces cardiac fibrosis and preserves LV function.

MicroRNA-214 promotes hepatic stellate cell activation and liver fibrosis by suppressing Sufu expression

MicroRNAs (miRNAs) have been demonstrated to modulate cellular processes in the liver. However, the role of miRNAs in liver fibrosis is poorly understood. Because the activation of hepatic stellate cells (HSCs) is a pivotal event in the initiation and progression of hepatic fibrosis, we investigate the differential expression of miRNAs in activated and quiescent rat HSCs by microarray analysis and find that miR-214 (miR-214-3p) is significantly upregulated during HSC activation. Moreover, the robust induction of miR-214 is correlated with liver fibrogenesis in carbon tetrachloride (CCl4)-treated rats and mice, high-fat diet-induced non-alcoholic steatohepatitis in mice, and cirrhosis in humans. We identify that miR-214 expression is driven by the helix-loop-helix transcription factor Twist1 via the E-box element. The increased miR-214 inhibits the expression of suppressor-of-fused homolog (Sufu), a negative regulator of the Hedgehog signaling pathway, thereby contributing to HSC activation to promote the accumulation of fibrous extracellular matrix and the expression of profibrotic genes in HSCs and LX2 cells. Furthermore, miR-214 expression is inversely correlated with the expression of Sufu in clinical cirrhosis samples. To explore the clinical potential of miR-214, we inject antagomiR-214 oligos into mice to induce hepatic fibrosis. The knockdown of miR-214 in vivo enhances Sufu expression and reduces fibrosis marker expression, which ameliorates liver fibrosis in mice. In conclusions, the Twist1-regulated miR-214 promotes the activation of HSC cells through targeting Sufu involved in the Hedgehog pathway and participates in the development of hepatic fibrosis. Hence, the knockdown of miR-214 expression may be a promising therapeutic strategy for liver fibrosis.