miR‑122/SENP1 axis confers stemness and chemoresistance to liver cancer through Wnt/β‑catenin signaling

The property of inherent stemness of tumor cells coupled with the development of chemoresistance results in a poor prognosis for patients with liver cancer. Therefore, the present study focused on microRNA (miR)-122, a potential tumor suppressor, the expression of which has been previously shown to be significantly decreased and negatively associated with cancer cell stemness in liver cancer. The present study aimed to identify the molecular targets of miR-122 whilst uncovering the mechanism underlying chemoresistance and stemness of HepG2 cells in liver cancer. Bioinformatics online tools, such as ENCORI, coupled with dual-luciferase reporter assays in HepG2 cells, were used to identify and validate small ubiquitin-like modifier (SUMO) specific peptidase 1 (SENP1) as a potential target of miR-122 in liver cancer. The liver cancer stem cell population was determined using sphere formation assays and flow cytometry, whilst stem cell markers (Oct3/4, Nanog, B lymphoma Mo-MLV insertion region 1 homolog and Notch1) were detected by reverse transcription-quantitative PCR. Chemoresistance, cell proliferation and migratory ability of HepG2 cells were monitored using Cell Counting Kit-8, colony formation and Transwell assays, respectively. The overexpression of miR-122 by mimic transfection led to a significant decrease in the number spheres, downregulation of stem cell marker expression, the number of CD24+ cells, drug-resistance protein levels (P-glycoprotein and multidrug resistance protein), impaired chemoresistance, proliferation and migration of HepG2 cells. The transfection of SENP1 overexpression vector resulted in contrasting functions to miR-122 mimics, by partially reversing the effects induced by miR-122 mimic transfection in HepG2 cells. Wnt/β-catenin signaling has been proven to be involved in cancer stemness and malignant behavior. Western blotting analysis in HepG2 cells showed that the expression levels of both Wnt1 and β-catenin were significantly reduced after overexpressing miR-122, but increased after overexpressing SENP1. Co-transfection with the SENP1 overexpression vector reversed the suppression induced by the miR-122 mimics on Wnt1 and β-catenin expression. Co-immunoprecipitation, SUMOylation and half-life assays showed SENP1 interacted with β-catenin and decreased the SUMOylation of β-catenin, thereby enhancing its stability. Finally, tumor xenograft analyses revealed that HepG2 cells transfected with Agomir-122 exerted significantly lower tumor initiation frequency and growth rate, and a superior response to DOX in vivo, compared with those transfected with Agomir NC. Taken together, data from the present study miR-122/SENP1 axis can regulate β-catenin stability through de-SUMOylation, thereby promoting stemness and chemoresistance in liver cancer.

Analysis of serum microRNA-122 in a randomized controlled trial of N-acetylcysteine for treatment of antituberculosis drug-induced liver injury

AIM

Serum microRNA-122 (miR-122) is a novel biomarker for drug-induced liver injury, with good sensitivity in the early diagnosis of paracetamol-induced liver injury. We describe miR-122 concentrations in participants with antituberculosis drug-induced liver injury (AT-DILI). We explored the relationship between miR-122 and alanine aminotransferase (ALT) concentrations and the effect of N-acetylcysteine (NAC) on miR-122 concentrations.

METHODS

We included participants from a randomized placebo-controlled trial of intravenous NAC in AT-DILI. ALT and miR-122 concentrations were quantified before and after infusion of NAC/placebo. We assessed correlations between ALT and miR-122 concentrations and described changes in ALT and miR-122 concentrations between sampling occasions.

RESULTS

We included 45 participants; mean age (± standard deviation) 38 (±10) years, 58% female and 91% HIV positive. The median (interquartile range) time between pre- and post-infusion biomarker specimens was 68 h (47-77 h). The median pre-infusion ALT and miR-122 concentrations were 420 U/L (238-580) and 0.58 pM (0.18-1.47), respectively. Pre-infusion ALT and miR-122 concentrations were correlated (Spearman's ρ = .54, P = .0001). Median fold-changes in ALT and miR-122 concentrations between sampling were 0.56 (0.43-0.69) and 0.75 (0.23-1.53), respectively, and were similar in the NAC and placebo groups (P = .40 and P = .68 respectively).

CONCLUSIONS

miR-122 concentrations in our participants with AT-DILI were considerably higher than previously reported in healthy volunteers and in patients on antituberculosis therapy without liver injury. We did not detect an effect of NAC on miR-122 concentrations. Further research is needed to determine the utility of miR-122 in the diagnosis and management of AT-DILI.

Multivalent Lactobionic Acid and N-Acetylgalactosamine-Conjugated Peptide Nucleic Acids for Efficient In Vivo Targeting of Hepatocytes

Peptide nucleic acids (PNAs) are used/applied in various studies to target genomic DNA and RNA to modulate gene expression. Non-specific targeting and rapid elimination always remain a challenge for PNA-based applications. Here, the synthesis, characterization, in vitro and in vivo study of di lactobionic acid (diLBA) and tris N-acetyl galactosamine (tGalNAc) conjugated PNAs for liver-targeted delivery are reported. For proof of concept, diLBA, and tGalNAc conjugated PNAs (anti-miR-122 PNAs) were synthesized to target microRNA-122 (miR-122) which is over-expressed in the hepatic tissue. Different lengths of anti-miR-122 PNAs conjugated with diLBA and tGalNAc are tested. Cell culture and in vivo analyses to determine biodistribution, efficacy, and toxicity profile are performed. This work indicates that diLBA conjugates show significant retention in hepatocytes in addition to tGalNAc conjugates after in vivo delivery. Full-length PNA conjugates show significant downregulation of miR-122 levels and subsequent de-repression of its downstream targets with no evidence of toxicity. The results provide a robust framework for ligand-conjugated delivery systems for PNAs that can be explored for broader biomedical applications.

Evaluation of diagnostic and prognostic candidate biomarkers in drug-induced liver injury versus other forms of acute liver damage

AIMS

Detection and characterization of idiosyncratic drug-induced liver injury (DILI) currently relies on standard liver tests, which are suboptimal in terms of specificity, sensitivity and prognosis. Therefore, DILI diagnosis can be delayed, with important consequences for the patient. In this study we aimed to evaluate the potential of osteopontin, cytokeratin-18 (caspase-cleaved: ccK18 and total: K18), α-glutathione-S-transferase and microRNA-122 as new DILI biomarkers.

METHODS

Serial blood samples were collected from 32 DILI and 34 non-DILI acute liver injury (ALI) cases and a single sample from 43 population controls without liver injury (HLC) and analysed using ELISA assays or single-molecule arrays.

RESULTS

All biomarkers differentiated DILI and ALI from HLC with an area under receiver operator characteristic curve (AUC) value >0.75, but were less efficient in distinguishing DILI from ALI, with ccK18 (0.79) and K18 (0.76) demonstrating highest potential. However, the AUC improved considerably (0.98) for ccK18 when comparing DILI and a subgroup of autoimmune hepatitis cases. Cytokeratin-18, microRNA-122 and α-glutathione-S-transferase correlated well with traditional transaminases, while osteopontin was strongest correlated with INR.

CONCLUSION

ccK18 appears promising in distinguishing DILI from autoimmune hepatitis, but less so from other forms of acute liver injury. Osteopontin demonstrates prognostic potential with higher levels detected in more severe cases regardless of aetiology.

[Retracted] MicroRNA‑122 affects cell aggressiveness and apoptosis by targeting PKM2 in human hepatocellular carcinoma

Following the publication of both the above article and a corrigendum (doi: 10.3892/or.2021.8073) that was concerned with the correction of overlapping data panels in Figs. 6 and 7, it has been drawn to the Editors' attention by a concerned reader that the proposed replacement cell invasion assay shown in the revised version of Fig. 7A, and also flow cytometric data featured in Fig. 5A and C, were strikingly similar to data appearing in different form in other articles by different authors. Owing to the fact that these contentious data in the above article had already been published elsewhere, or were already under consideration for publication, prior to its submission to Oncology Reports, the Editor has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a reply. The Editor apologizes to the readership for any inconvenience caused. [Oncology Reports 34: 2054‑2064, 2015; DOI: 10.3892/or.2015.4175].

microRNA-122 inhibits hepatic stellate cell proliferation and activation in vitro and represses carbon tetrachloride-induced liver cirrhosis in mice

OBJECTIVE

This study aimed to determine the roles of microRNA (miR)-122 in the activation of hepatic stellate cells (HSCs) and liver cirrhosis.

METHODS

Rat primary HSCs were incubated with transforming growth factor-beta (TGF-β), during which miR-122 and EphB2 expression was measured. miR-122 mimic and/or pcDNA3.1 EphB2 was transfected into TGF-β-induced HSCs. A mouse model of liver cirrhosis was established via an intraperitoneal injection of carbon tetrachloride (CCl₄), followed by the injection of miR-122 agomir. Levels of serum alanine transaminase (ALT) and aspartate aminotransferase (AST) were measured. Fibronectin (FN), alpha smooth muscle actin (α-SMA), Collagen I, miR-122, and EphB2 expression was evaluated in liver tissues and HSCs. Cell proliferation was measured using CCK-8 assay. Interactions between miR-122 and EphB2 were assessed using dual luciferase reporter assay.

RESULTS

miR-122 (0.15-fold) was downregulated and EphB2 (mRNA: 5.06-fold; protein: 2.35-fold) was upregulated after TGF-β induction of HSCs. Overexpressed miR-122 decreased proliferation and EphB2 (mRNA: 0.46-fold; protein: 0.62-fold), FN (mRNA: 0.45-fold; protein: 0.64-fold), α-SMA (mRNA: 0.48-fold; protein: 0.51-fold), and Collagen I (mRNA: 0.44-fold; protein: 0.51-fold) expression in HSCs, which was abrogated by EphB2 upregulation. miR-122 expression was reduced by 0.21-fold and serum ALT and AST levels were enhanced in mice following 8-week CCl₄ induction along with increased expression of FN, α-SMA, and Collagen I in liver tissues, which was blocked by miR-122 overexpression. Moreover, EphB2 was a target gene of miR-122.

CONCLUSION

miR-122 curtails HSC proliferation and activation by targeting EphB2 and suppresses liver cirrhosis in mice.

Circulating microRNAs (miR-16, miR-22, miR-122) expression and early diagnosis of hepatocellular carcinoma

Purpose

Circulating microRNA (miRNA) has been reported to have diagnostic value in multiple tumors. To identify serum miRNAs for early diagnosis of hepatocellular carcinoma (HCC), we analyzed the differential miRNA expression between HCC patients and controls.

Methods

Real‐time reverse transcription polymerase chain reaction (RT‐PCR) was carried out to detect serum miR‐16, miR‐22, and miR‐122 expression in 100 HCC patients and 100 controls (including hepatitis B, liver cirrhosis, liver metastases, hepatic hemangioma, health group, and each of them had 20 subjects). The miRNA expression results were combined with alpha‐fetoprotein (AFP) to evaluate the diagnostic efficacy in HCC through receiver operating characteristic (ROC) curve. And the target genes were predicted through bioinformatics methods.

Results

Compared with controls, the expression of miR‐16 and miR‐122 significantly increased in early‐stage HCC patients, while no significant changes were detected in miR‐22. The ROC curve analysis demonstrated that miR‐16 and miR‐122 had a high diagnostic efficacy (AUC 0.798 and 0.759), and it was improved when combined with AFP (AUC 0.862). When compared with each of the five groups in the controls, the results showed that miR‐16 of HCC was significantly higher than liver cirrhosis (AUC 0.936), liver metastases, and health; miR‐122 was significantly higher than liver metastases, hepatitis B, and health. Moreover, 175 and 101 potential target genes were regulated by miR‐16 and miR‐122, respectively. And most of the target genes were enriched in the PI3K, MAPK, FoxO signaling pathways, and pathways in cancer.

Conclusion

Our findings illustrate that both circulating miR‐16 and miR‐122 can provide value for early diagnosis of HCC and they are potential biomarkers for the early‐stage HCC.

Circulating Levels of microRNA-122 and Hepatic Fat Change in Response to Weight-Loss Interventions: CENTRAL Trial

PURPOSE

Little is known about the relations between changes in circulating microRNA-122 (miR-122) and liver fat in response to weight-loss interventions. We aimed to investigate the association between miR-122 and changes of hepatic fat content during 18-month diet and physical activity interventions.

METHODS

The CENTRAL trial is an 18-month randomized, controlled trial among adults with abdominal obesity or dyslipidemia. Subjects were randomly assigned to a low-fat diet or a Mediterranean/low-carbohydrate diet. After 6 months of dietary intervention, each diet group was further randomized into added physical activity groups or no added physical activity groups for the following 12 months of intervention. The current study included 220 participants at baseline and 134 participants with repeated measurements on serum miR-122 and hepatic fat content over 18 months.

RESULTS

Serum miR-122 significantly increased from baseline to 18 months, while no difference was observed across the 4 intervention groups. We found a significant association between miR-122 and hepatic fat content at baseline, as per unit increment in log-transformed miR-122 was associated with 3.79 higher hepatic fat content (P < 0.001). Furthermore, we found that higher elevations in miR-122 were associated with less reductions in hepatic fat percentage during 18-month interventions (β = 1.56, P = 0.002). We also found a significant interaction between changes in miR-122 and baseline fasting plasma glucose with hepatic fat content changes in 18 months (P interaction = 0.02).

CONCLUSIONS

Our data indicate that participants with higher elevation in serum miR-122 may benefit less in reduction of hepatic fat content in response to diet and physical activity interventions.

MicroRNA 122 Affects both the Initiation and the Maintenance of Hepatitis C Virus Infections

A liver-specific microRNA, miR-122, anneals to the hepatitis C virus (HCV) genomic 5' terminus and is essential for virus replication in cell culture. However, bicistronic HCV replicons and full-length RNAs with specific mutations in the 5' untranslated region (UTR) can replicate, albeit to low levels, without miR-122. In this study, we have identified that HCV RNAs lacking the structural gene region or having encephalomyocarditis virus internal ribosomal entry site (EMCV IRES)-regulated translation had reduced requirements for miR-122. In addition, we found that a smaller proportion of cells supported miR-122-independent replication compared a population of cells supporting miR-122-dependent replication, while viral protein levels per positive cell were similar. Further, the proportion of cells supporting miR-122-independent replication increased with the amount of viral RNA delivered, suggesting that establishment of miR-122-independent replication in a cell is affected by the amount of viral RNA delivered. HCV RNAs replicating independently of miR-122 were not affected by supplementation with miR-122, suggesting that miR-122 is not essential for maintenance of an miR-122-independent HCV infection. However, miR-122 supplementation had a small positive impact on miR-122-dependent replication, suggesting a minor role in enhancing ongoing virus RNA accumulation. We suggest that miR-122 functions primarily to initiate an HCV infection but has a minor influence on its maintenance, and we present a model in which miR-122 is required for replication complex formation at the beginning of an infection and also supports new replication complex formation during ongoing infection and after infected cell division. IMPORTANCE The mechanism by which miR-122 promotes the HCV life cycle is not well understood, and a role in directly promoting genome amplification is still debated. In this study, we have shown that miR-122 increases the rate of viral RNA accumulation and promotes the establishment of an HCV infection in a greater number of cells than in the absence of miR-122. However, we also confirm a minor role in promoting ongoing virus replication and propose a role in the initiation of new replication complexes throughout a virus infection. This study has implications for the use of anti-miR-122 as a potential HCV therapy.

Dynamics of Circulating miR-122 Predict Liver Cancer and Mortality in Japanese Patients with Histopathologically Confirmed NAFLD and Severe Fibrosis Stage

INTRODUCTION

It is unclear whether the relationships between changes in fibrosis and circulating microRNA-122 (miR-122) dynamics might influence the prognosis of nonalcoholic fatty liver disease (NAFLD).

METHODS

This study investigates the impact of serum miR-122 dynamics and histological changes on the incidence of liver cancer and mortality in 81 Japanese NAFLD patients who underwent serial liver biopsies. The median interval between the first and second liver biopsies was 2.9 years.

RESULTS

The fibrosis stage scores indicated progression, no change, and improvement (a decrease of one point or more) in 21.0%, 56.8%, and 22.2% of the patients, respectively. There were 64 patients in the high-risk group who had no improvement in stage scores. Among these, the miR-122 levels were significantly lower in 7 patients with liver cancer than those of the 54 patients who had no liver cancer at the second liver biopsy. The cumulative rates of liver cancer were significantly higher in cases with miR-122 ratios <0.5 (serum miR-122 level at second biopsy to that at first biopsy) than those with ratios ≥0.5. The cumulative survival rates in cases with miR-122 ratios <0.5 tended to be lower than those with ratios ≥0.5. Of the 64 high-risk patients, 39 indicated stage 2 or greater (severe fibrosis stage) at the first liver biopsy and also showed similar results of cumulative liver cancer and survival rates.

CONCLUSIONS

Longitudinal examination of serial liver biopsies indicated that the circulating miR-122 dynamics might be useful in predicting the prognosis for NAFLD patients with severe fibrosis stage and no improvement of the stage scores.

Overexpression of miR-122 promotes apoptosis of dermal papilla cells by directly targeting IGF1R in androgenetic alopecia

Androgenetic alopecia (AGA) is the most common pattern of hair loss resulting from the effects of androgen on hair follicle. MicroRNAs (miRs) serve imperative roles in the regulation of many biological processes of hair follicle. However, the exact molecular mechanism of AGA remains to be elucidated. In the present study, we found miR-122, which is mainly recognized as a tumor suppressor, was highly overexpressed in the bulb of balding HFs in comparison with non-balding ones in AGA. Moreover, miR-122 induces apoptosis of human dermal papilla cells (hDPCs) with miR-122 mimics in vitro, and the expression of insulin-like growth factor 1 receptor (IGF1R) in hDPCs was reduced following upregulation of miR-122. Mechanistically, dual luciferase reporter assay confirmed that miR-122 directly targeted the 3'-untranslated region of IGF1R.These findings suggested that upregulation of miR-122 induces apoptosis, potentially via the repression of IGF1R in hDPCs of AGA, providing a novel insight into the potential pathological mechanism of miR-122 in AGA DPCs. This article is protected by copyright. All rights reserved.

Over-Expression of MicroRNA-122 Inhibits Proliferation and Induces Apoptosis in Colon Cancer Cells

BACKGROUND

MicroRNA, a non-coding RNA molecule plays a vital role in post transcriptional gene expression. MicroRNA-122, a liver specific microRNA was found to be downregulated in liver cancer and is associated with hepatocarcinogenesis. Being confirmed as tumor suppressor microRNA in liver carcinogenesis, we aimed to study the expression of microRNA-122 in colon cancer cell lines and the role of microRNA-122 in cell proliferation, invasion and migration of colon cancer cells.

METHODS

The expression of microRNA-122 is quantified using qRT-PCR by TaqMan universal primers. Colon cancer cell lines (SW480, SW620, HCT116) were transfected with microRNA-122 mimic and further studied for determining cell proliferation using CCK-8 kit, migration using Scratch assay, invasion using Transwell assay, apoptosis using Annexin-V FITC kit, and also gene expression.

RESULTS

Gene expression results displayed decreased expression of microRNA-122 in colon cancer cell lines. Transfection with microRNA-122 mimics impaired the cell proliferation and migration compared with control. FACS analysis confirmed that the percentage of microRNA-122 mimic transfected cells undergoing early apoptosis was increased. Gene expression of AEG-1, PI3K, CDK6, and PCNA were found to be downregulated in microRNA-122 overexpressed cells. Migratory and invasion potential of transfected cells was lessened in mimic transfected cells compared to control.

CONCLUSION

The overexpression of microRNA-122 inhibited the cellular proliferation, migration, invasion and increased percentage of cells undergoing early apoptosis, suggesting its anti-cancer potential. Studying the role of microRNA-122 and its interactions with oncogenes might pave the way to understand the underlying mechanism in colon cancer.

MicroRNA-122 as a diagnostic biomarker for hepatocellular carcinoma related to hepatitis C virus: a meta-analysis and systematic review

Objective

MicroRNA-122 (miR-122) has been identified as a biomarker of liver diseases. However, the miR-122 detection accuracy in patients with hepatocellular carcinoma (HCC) associated with hepatitis C virus (HCV) is inconclusive.

Methods

We conducted a systematic literature search of Web of Science, Cochrane Library, PubMed, and Embase to identify studies related to the diagnostic value of miR-122 in HCV-related HCC. We analyzed the results and validated them using data from the Cancer Genome Atlas (TCGA).

Results

Six articles were included in this meta-analysis, comprising 354 cases and 420 controls. The pooled specificity, sensitivity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and area under the curve were 0.87, 0.83, 5.1, 0.16, 32, and 0.92, respectively. Additional sub-group analyses showed that results for plasma were more sensitive than those for serum. In addition, miR-122 was better at distinguishing between HCV-associated HCC and healthy people or those with HCV than between those with HCV-associated HCC and HCV-related cirrhosis. Small samples (≤100) had better diagnostic odds ratios than larger samples (>100). Analysis of data from TCGA confirmed that miRNA-122 had a high diagnostic value.

Conclusion

This meta-analysis demonstrates that miR-122 may be a useful diagnostic biomarker for HCV-associated HCC.

Efficacy of evaluation of microRNA-122 and microRNA-21 levels in the role of biomarkers of oligosymptomatic choledocholithiasis in patients with acute calculous cholecystitis

AIM

The aim of this study was to evaluate the efficacy of determining the microRNA-122 and microRNA-21 expression levels in serum and bile as predictors of the presence of oligosymptomatic choledocholithiasis in patients with acute calculous cholecystitis.

MATERIALS AND METHODS

The study included 32 patients who were divided into two groups: I - study group and II - comparison group. The study group included patients with acute calculous cholecystitis (ACC) and oligosymptomatic choledocholithiasis (OCL) (n=23), and the comparison group consisted of patients with ACC without choledocholithiasis (n=9). Conditionally healthy people (volunteers, n=20) who made up the third group.

RESULTS

Comparison analysis of the expression levels of the studied microRNAs in all clinical groups revealed statistically significant differences for both microRNA-122 and microRNA-21. As a result of ROC analysis, the multivariate model for the prediction of OCL presence had better characteristics (AUC=0.95 vs. AUC=0.90) when compared to the univariate test for determining the microRNA-122 level in bile. The cut-off threshold for the presence or absence of OCL (cut-off) is equal to 77. Values higher than the given are regarded as the presence of OCL, and the lower ones indicate the absence of it. The sensitivity of this model was 87.0%, specificity - 100%, accuracy - 90.6%.

CONCLUSIONS

The detected changes in the levels of microRNA-122 and microRNA-21 in serum and bile indicate the possibility of using them as a diagnostic marker of oligosymptomatic choledocholithiasis. The increase in expression of microRNA-122 and microRNA-21 in serum is likely (p<0.05) to be associated with high expression levels in bile. The probability model of the presence of oligosymptomatic choledocholithiasis in patients with acute calculous cholecystitis using quantitative determination of expression levels of microRNA-122 and microRNA-21 in serum and bile has high prognostic significance and can be recommended for application in clinical protocols of patient examination.

ΜicroRNA-122 protects against ischemic stroke by targeting Maf1

The protection of brain tissue against damage and the reduction of infarct size is crucial for improving patient prognosis following ischemic stroke. Therefore, the present study aimed to investigate the regulatory effect of microRNA (miR)-122 and its target gene repressor of RNA polymerase III transcription MAF1 homolog (Maf1) on the infarct area in ischemic stroke. Reverse transcription-quantitative PCR (RT-qPCR) was performed to determine miR-122 expression levels in an ischemic stroke [middle cerebral artery occlusion (MCAO)] mouse model. Nissl staining was conducted to measure the infarct area of the MCAO mouse model. Moreover, RT-qPCR was performed to investigate the relationship between the expression of Maf1 and miR-122 in the MCAO mouse model. Dual-luciferase reporter assay in vitro and miR-122 mimic or inhibitor treatment in vivo were conducted to verify that miR-122 targeted and inhibited Maf1 expression. The results suggested that miR-122 was upregulated in the brain tissue of MCAO model mice. miR-122 overexpression effectively reduced the size of the infarct area in comparison with a control and miR-122 knockdown in brain tissue resulted in the opposite effect. Moreover, Maf1 was confirmed to be a direct target of miR-122. The results of a dual-luciferase reporter assay indicated that miR-122 bound to the 3'-untranslated region of Maf1. Maf1 expression decreased after stroke model induction in comparison with that in sham animals, and Maf1 expression was negatively associated with the expression of miR-122. In addition, miR-122 knockdown increased Maf1 expression levels, whereas miR-122 overexpression decreased Maf1 expression levels in comparison with a control. In conclusion, the results suggested that miR-122 improved the outcome of acute ischemic stroke by reducing the expression of Maf1.

Evaluation of MicroRNA-122 as a Biomarker for Chronic Hepatitis C Infection and as a Predictor for Treatment Response to Direct-Acting Antivirals

Background

Treatment response to antiviral drugs is a challenging issue in patients with chronic hepatitis C virus (HCV) infection. Although microRNA-122 represents the majority of the microRNA content in hepatic tissues, few studies have evaluated its role in the treatment response, so we aimed to study its role in chronic HCV patients and in predicting the treatment response to direct-acting antivirals (DAAs).

Methods

The study included 125 chronic HCV patients (89 naïve and 36 with a prior failed peginterferon/ribavirin response) and 50 apparently healthy subjects. Complete blood count, liver function, α-fetoprotein, lipid profiles, serum creatinine, abdominal ultrasound, and FibroScan^® were assessed. Viral markers, HCV antibodies, and hepatitis B surface antigen were measured by enzyme-linked fluorescent immunoassay, with quantitative estimation of HCV RNA and microRNA-122 levels by real-time PCR.

Results

The microRNA-122 level in HCV patients (those with a sustained virologic response 12 weeks after finishing therapy [SVR12] and non-responders) was significantly increased compared with controls and expressed more in non-responders versus SVR12 (p=0.042). ROC curve analysis of microRNA-122 for differentiating HCV patients from healthy controls revealed that a cut-off point of >1.45 had a sensitivity of 67.20%, specificity of 94.0%, AUC=0.861, and p<0.001; and for predicting response to treatment a cut-off point ≤5.66 could significantly (p=0.022) predict the occurrence of SVR, with a sensitivity of 60.34%, specificity of 66.67%, and AUC=0.729. Logistic regression analysis showed significant values for microRNA-122 in multivariate and univariate analysis for the prediction of response to DAAs.

Conclusion

The results demonstrated the possible function of microRNA-122 as an indicative tool for distinguishing chronic HCV patients from controls and in the assessment of the therapeutic reaction to DAAs.

MicroRNA-122 regulates docetaxel resistance of prostate cancer cells by regulating

Prostate cancer (PCa), an epithelial malignancy that occurs in the prostate, is the second leading cause of cancer death worldwide. MicroRNAs (miRs/miRNAs) are reported to have important applications in the field of cancer diagnosis and treatment. The present study aimed to investigate the function of miRNA-122 in the chemoresistance of PCa cells and the underlying mechanism. Significantly decreased miR-122 and increased pyruvate kinase (PKM2) levels were observed in docetaxel-resistant PCa cells, and PKM2 was negatively correlated with miR-122. MiR-122 mimic transfection in docetaxel-resistant LNCaP cells significantly inhibited cell proliferation, promoted apoptosis and decreased glucose uptake and lactate production, which was counteracted by PKM2 overexpression. Inhibition of miR-122 in LNCaP cells had an opposite effect to miR-122 mimic transfection. In addition, miR-122 mimic transfection significantly increased the sensitivity of docetaxel-resistant LNCaP cells to docetaxel, while inhibition of miR-122 significantly decreased the sensitivity of LNCaP cells to docetaxel. Luciferase reporter assays showed that miR-122 regulated PKM2 expression by binding to the 3'-untranslated region of PKM2. The results suggest that upregulation of miR-122 could enhance docetaxel sensitivity, inhibit cell proliferation and promote apoptosis in PCa cells,possibly through the downregulation of its target protein PKM2.

Roles of MicroRNA-122 in Cardiovascular Fibrosis and Related Diseases

Fibrotic diseases cause annually more than 800,000 deaths worldwide, where of the majority accounts for cardiovascular fibrosis, which is characterized by endothelial dysfunction, myocardial stiffening and reduced dispensability. MicroRNAs (miRs), small noncoding RNAs, play critical roles in cardiovascular dysfunction and related disorders. Intriguingly, there is a critical link among miR-122, cardiovascular fibrosis, sirtuin 6 (SIRT6) and angiotensin-converting enzyme 2 (ACE2), which was recently identified as a coreceptor for SARS-CoV2 and a negative regulator of the rennin-angiotensin system. MiR-122 overexpression appears to exacerbate the angiotensin II-mediated loss of autophagy and increased inflammation, apoptosis, extracellular matrix deposition, cardiovascular fibrosis and dysfunction by modulating the SIRT6-Elabela-ACE2, LGR4-β-catenin, TGFβ-CTGF and PTEN-PI3K-Akt signaling pathways. More importantly, the inhibition of miR-122 has proautophagic, antioxidant, anti-inflammatory, anti-apoptotic and antifibrotic effects. Clinical and experimental studies clearly demonstrate that miR-122 functions as a crucial hallmark of fibrogenesis, cardiovascular injury and dysfunction. Additionally, the miR-122 level is related to the severity of hypertension, atherosclerosis, atrial fibrillation, acute myocardial infarction and heart failure, and miR-122 expression is a risk factor for these diseases. The miR-122 level has emerged as an early-warning biomarker cardiovascular fibrosis, and targeting miR-122 is a novel therapeutic approach against progression of cardiovascular dysfunction. Therefore, an increased understanding of the cardiovascular roles of miR-122 will help the development of effective interventions. This review summarizes the biogenesis of miR-122; regulatory effects and underlying mechanisms of miR-122 on cardiovascular fibrosis and related diseases; and its function as a potential specific biomarker for cardiovascular dysfunction.

Role of microRNA-122 in microcystin-leucine arginine-induced dysregulation of hepatic iron homeostasis in mice

Microcystin-leucine arginine (MC-LR) is a cyclic heptapeptide hepatotoxin produced by cyanobacteria. MicroRNA-122 (miR-122) is specifically expressed in the liver. This study focuses on the role of miR-122 in MC-LR-induced dysregulation of hepatic iron homeostasis in C57BL/6 mice. The thirty mice were randomly divided into five groups (Control, 12.5 μg/kg·BW MC-LR, 25 μg/kg·BW MC-LR, Negative control agomir and 25 μg/kg·BW MC-LR + miR-122 agomir). The results show that MC-LR decreases the expressions of miR-122, Hamp, and its related regulators, while increasing the content of hepatic iron and the expressions of FPN1 and Tmprss6. Furthermore, miR-122 agomir pretreatment improves MC-LR induced dysregulation of hepatic iron homeostasis by arousing the related regulators and reducing the expression of Tmprss6. These results suggest that miR-122 agomir can prevent the accumulation of hepatic iron induced by MC-LR, which may be related to the regulation of hepcidin by BMP/SMAD and IL-6/STAT signaling pathways.

Granulocyte Colony Stimulating Factor (GCSF) Can Attenuate Neuropathic Pain by Suppressing Monocyte Chemoattractant Protein-1 (MCP-1) Expression, through Upregulating the Early MicroRNA-122 Expression in the Dorsal Root Ganglia

Our previous animal studies and several human clinical trials have shown that granulocyte-colony stimulating factor (GCSF) can attenuate neuropathic pain through various mechanisms. GCSF itself is also a multipotent cytokine that can modulate microribonucleic acid (microRNA) expression profiles in vitro. In this study, we used the NanoString nCounter analysis system to screen the expression of different rodent microRNAs at early stage after nerve injury and studied the expression of related cytokines/chemokines in the dorsal root ganglia (DRGs) of rats that underwent chronic constriction injury (CCI) to explore the underlying mechanisms of the analgesic effects of GCSF. We found that microRNA-122 expression was downregulated by CCI; in contrast, GCSF treatment significantly upregulated microRNA-122 expression in the DRGs of CCI rats on the 1st day after nerve injury. We further studied the expression of different cytokines/chemokines (IL-1β, IL-6, and monocyte chemoattractant protein-1 (MCP-1)) that were modulated by microRNA-122. MCP-1 has been reported to participate in neuropathic pain development, and its expression on the DRGs of vehicle-treated CCI rats was significantly higher than that on the DRGs of sham-operated rats; in contrast, GCSF-treated rats exhibited significantly lower MCP-1 expression in the DRG than vehicle-treated rats on the 7th day after nerve injury. An early GCSF treatment can suppress MCP-1 expressions, through upregulating microRNA-122 expressions in the DRGs of CCI rats at an earlier stage, thus indirectly attenuating neuropathic pain development.

Inhibition of Endoplasmic Reticulum Stress Attenuated Ethanol-Induced Exosomal miR-122 and Acute Liver Injury in Mice

AIMS

In acute alcoholic liver injury, alcohol can directly or indirectly induce endoplasmic reticulum stress (ERS) to participate in liver injury, and it is found that the expression of serum exosomal miR-122 is significantly affected. Therefore, the present study investigated the effects of endoplasmic reticulum stress inhibition on the expression of serum exosomal miR-122 and acute liver injury.

METHODS

The acute alcoholic liver injury models were established by the intragastric administration of ethanol (5 g/kg) in ICR mice. Intervention group received 4-phenylbutyric acid (PBA, endoplasmic reticulum stress inhibitor; 75 mg/kg and 150 mg/kg, intraperitoneal) 12 and 24 hours before intragastric administration. Mice treated with saline were used as controls.

RESULTS

The ethanol treated mice exhibited significantly elevated hepatosomatic index (liver weight/body weight) and alanine aminotransferase (ALT), compared with those in the control group (P < 0.05). The ERS inhibitor 4-phenylbutyric acid protected against ethanol induced acute liver injury and hepatocyte necrosis, and PBA 150 mg/kg significantly attenuated ethanol induced hepatic ER stress-related proteins (GRP78, pIRE1α and pIF2α) (P < 0.05). Moreover, PBA 150 mg/kg markedly alleviated ethanol induced elevation of hepatic and serum exosomal miR-122 and pri-miR-122 (P < 0.05).

CONCLUSIONS

These findings suggest that ER stress inhibitor PBA attenuated ethanol induced acute liver injury and serum exosomal miR-122, and provides a potential therapy strategy for acute alcoholic liver injury.

miR-122 Exerts Inhibitory Effects on Osteoblast Proliferation/Differentiation in Osteoporosis by Activating the PCP4-Mediated JNK Pathway

Osteoporosis is characterized by the reduction of bone mineral density and deterioration of bone quality which leads to high risk of fractures. Some microRNAs (miRNAs) have been confirmed as potential modulators of osteoblast differentiation to maintain bone mass maintenance. We aimed to clarify whether miR-122 could regulate osteoblast differentiation in ovariectomized rats with osteoporosis. miR-122 was upregulated and Purkinje cell protein 4 (PCP4) was downregulated in ovariectomized rats. PCP4 was identified as a target of miR-122 by dual-luciferase reporter gene assay. We transfected isolated osteoblasts from ovariectomized rats with miR-122 mimic or inhibitor or PCP4 overexpression vectors. Proliferation and differentiation of osteoblasts were repressed by the overexpression of miR-122 but enhanced by overexpression of PCP4. miR-122 could induce the activation of the c-Jun NH2-terminal kinase (JNK) signaling pathway, while PCP4 blocked this pathway. Rescue experiments further demonstrated that the inhibiting effects of miR-122 on osteoblast differentiation could be compensated by activation of the PCP4 or inhibition of JNK signaling pathway. Collectively, our data imply that miR-122 inhibits osteoblast proliferation and differentiation in rats with osteoporosis, highlighting a novel therapeutic target for osteoporotic patients.

Transcription Factor E2F1 Aggravates Neurological Injury in Ischemic Stroke via microRNA-122-Targeted Sprouty2

BACKGROUND

It has been documented that microRNAs (miRs) assume a pivotal role in the development of ischemic stroke (IS). However, it remains poorly identified about the role of miR-122 in IS. Herein, this study was intended to explore the mechanism of E2F1-orchestrated miR-122 in IS.

PATIENTS AND METHODS

E2F1, miR-122, and SPRY2 expression in serum from patients with IS and oxygen-glucose deprivation (OGD)-treated N2a cells was detected by RT-qPCR. After gain- and loss-of-function approaches in OGD-induced N2a cells, GAFP staining, flow cytometry, and Western blot analysis were adopted to assess neuronal viability, cell cycle and apoptosis, and expression of apoptosis- and autophagy-related proteins, respectively. Meanwhile, mice with IS were induced, in which E2F1, miR-122, and SPRY2 were overexpressed, followed by evaluation of neurological deficit and cerebral infarction area. The MAPK pathway activity in tissues of mice and cells was determined.

RESULTS

miR-122 was down-regulated, and E2F1 and SPRY2 were up-regulated in IS patients and OGD-induced N2a cells. E2F1 inhibited miR-122 transcription, while miR-122 targeted SPRY2. Overexpression (OE) of miR-122 or down-regulation of E2F1 or SPRY2 increased viability, but decreased apoptosis, cell cycle arrest, and autophagy in OGD-induced N2a cells. In IS mice, the neurological deficit score and cerebral infarction area were elevated, which was aggravated by up-regulating E2F1 or SPRY2 but attenuated by overexpressing miR-122. E2F1/miR-122/SPRY2 axis mediated the MAPK pathway in vivo and in vitro.

CONCLUSION

Collectively, E2F1 reduced miR-122 transcription to up-regulate SPRY2, which inactivated MAPK pathway and promoted neurological deficit in IS.