MiR-122-5p knockdown protects against APAP-mediated liver injury through up-regulating NDRG3

Advances in the study of the mechanism of action of miR‑22 in liver lesions (Review)

Globally, nearly 2 million deaths annually are attributed to the development of liver diseases, with liver cancer and cirrhosis being particularly prominent, which makes liver disease a significant global health concern. Cirrhosis is closely linked to the evolution of hepatitis, hepatic fibrosis and fatty liver. However, most liver diseases have an insidious onset, are challenging to treat and the prognosis and efficacy of current therapies are unsatisfactory, which can result in irreversible functional damage to the liver. Therefore, there is an urgent need to explore the molecular mechanisms underlying liver disease and identify new biomarkers and therapeutic targets. In previous years, microRNAs (miRs), a class of short non-coding RNAs comprising 17-25 nucleotides, have attracted attention for their roles in various types of liver diseases. Among them, miR-22 serves a unique role in mediating multiple pathway mechanisms and epigenetic modifications and can act both as an inhibitor of liver cancer and a metabolic blocker. Given its close association with the liver, several studies have reported that the differential expression of miR-22 regulates the metabolic process of liver cancer and is involved in the evolution of hepatic fibrosis and steatohepatitis, making it a potential target for early diagnosis and treatment. The present manuscript aimed to comprehensively review the key role of miR-22 in the evolution of liver diseases and offer valuable references and guidance for subsequent studies by identifying its specific mechanism of action and future development prospects.

HSCs-derived exosomes regulate the levels of inflammatory cytokines in HIBECs through miR-122-5p mediated p38 MAPK signaling pathway

PBC is an autoimmune-mediated liver disease, and intrahepatic biliary epithelial cells (IBECs) are the target cells of early damage. Previous studies found that miRNAs and inflammation is closely related to PBC. In this study, we extracted exosomes from serum and human IBECs supernatant, and RNA-sequence analyzed the expression profiles of miRNAs. Elisa measured the levels of inflammatory cytokines. RT- qPCR and western blot detected the levels of miR-122-5p, p38 and p-p38. The results showed that 263 differentially expressed (DE) miRNAs were identified in serum exosomes of PBC patients. The levels of IL-1β, IL-6, IL-12, IL-17 A, IFN-γ, TNF-α and TGF-β1 in peripheral blood of PBC patients were higher than those of normal controls. According to the validation results and previous literature, exosomal miR-122-5p was finally selected as the study object, and correlated with inflammatory factors. In vitro experiments further found that exosomal miR-122-5p may derive from hepatic stellate cells (HSCs), and can be HIBECs intake, and influence HIBECs inflammatory factor levels though p38 MAPK signaling pathways. This may provide a new strategy for the treatment of PBC.

Inhibition of MicroRNA-122-5p Relieves Myocardial Ischemia-Reperfusion Injury via SOCS1

OBJECTIVE

 Evidence has shown that microRNA (miR)-122-5p is a diagnostic biomarker of acute myocardial infarction. Here, we aimed to uncover the functions of miR-122-5p in the pathological process of myocardial ischemia-reperfusion injury (MI/RI).

METHODS

 An MI/RI model was established by left anterior descending coronary artery ligation in mice. The levels of miR-122-5p, suppressor of cytokine signaling-1 (SOCS1), phosphorylation of Janus kinase 2 (p-JAK2), and signal transducers and activators of transcription (p-STAT3) in the myocardial tissues of mice were measured. Downregulated miR-122-5p or upregulated SOCS1 recombinant adenovirus vectors were injected into mice before MI/RI modeling. The cardiac function, inflammatory response, myocardial infarction area, pathological damage, and cardiomyocyte apoptosis in the myocardial tissues of mice were evaluated. Cardiomyocytes were subjected to hypoxia/reoxygenation (H/R) injury and cardiomyocyte biological function was tested upon transfection of miR-122-5p inhibitor. The target relation between miR-122-5p and SOCS1 was evaluated.

RESULTS

 miR-122-5p expression and p-JAK2 and p-STAT3 expression were high, and SOCS1 expression was low in the myocardial tissues of MI/RI mice. Decreasing miR-122-5p or increasing SOCS1 expression inactivated the JAK2/STAT3 pathway to alleviate MI/RI by improving cardiac function and reducing inflammatory reaction, myocardial infarction area, pathological damage, and cardiomyocyte apoptosis in mice. Silencing of SOCS1 reversed depleted miR-122-5p-induced cardioprotection for MI/RI mice. In vitro experiments revealed that the downregulation of miR-122-5p induced proliferative, migratory, and invasive capabilities of H/R cardiomyocytes while inhibiting apoptosis. Mechanically, SOCS1 was a target gene of miR-122-5p.

CONCLUSION

 Our study summarizes that inhibition of miR-122-5p induces SOCS1 expression, thereby relieving MI/RI in mice.

Genetic and Epigenetic Basis of Drug-Induced Liver Injury

Drug-induced liver injury (DILI) is a rare but severe adverse drug reaction seen in pharmacotherapy and a major cause of postmarketing drug withdrawals. Advances in genome-wide studies indicate that genetic and epigenetic diversity can lead to inter-individual differences in drug response and toxicity. It is necessary to identify how the genetic variations, in the presence of environmental factors, can contribute to development and progression of DILI. Studies on microRNA, histone modification, DNA methylation, and single nucleotide polymorphisms related to DILI were retrieved from databases and were analyzed for the current research and updated to develop this narrative review. We have compiled some of the major genetic, epigenetic, and pharmacogenetic factors leading to DILI. Many validated genetic risk factors of DILI, such as variants of drug-metabolizing enzymes, HLA alleles, and some transporters were identified. In conclusion, these studies provide useful information in risk alleles identification and on implementation of personalized medicine.

Upregulation of microRNA-125b-5p alleviates acute liver failure by regulating the Keap1/Nrf2/HO-1 pathway

Background

Acute liver failure (ALF) and acute-on-chronic liver failure (ACLF) are the two most common subtypes of liver failure. They are both life-threatening clinical problems with high short-term mortality. Although liver transplantation is an effective therapeutic, its application is limited due to the shortage of donor organs. Given that both ACLF and ALF are driven by excessive inflammation in the initial stage, molecules targeting inflammation may benefit the two conditions. MicroRNAs (miRNAs) are a group of small endogenous noncoding interfering RNA molecules. Regulation of miRNAs related to inflammation may serve as promising interventions for the treatment of liver failure.

Aims

To explore the role and mechanism of miR-125b-5p in the development of liver failure.

Methods

Six human liver tissues were categorized into HBV-non-ACLF and HBV-ACLF groups. Differentially expressed miRNAs (DE-miRNAs) were screened and identified through high-throughput sequencing analysis. Among these DE-miRNAs, miR-125b-5p was selected for further study of its role and mechanism in lipopolysaccharide (LPS)/D-galactosamine (D-GalN) -challenged Huh7 cells and mice in vitro and in vivo.

Results

A total of 75 DE-miRNAs were obtained. Of these DE-miRNAs, miR-125b-5p was the focus of further investigation based on our previous findings and preliminary results. We preliminarily observed that the levels of miR-125b-5p were lower in the HBV-ACLF group than in the HBV-non-ACLF group. Meanwhile, LPS/D-GalN-challenged mice and Huh7 cells both showed decreased miR-125b-5p levels when compared to their untreated control group, suggesting that miR-125b-5p may have a protective role against liver injury, regardless of ACLF or ALF. Subsequent results revealed that miR-125b-5p not only inhibited Huh7 cell apoptosis in vitro but also relieved mouse ALF in vivo with evidence of improved liver histology, decreased alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, and reduced tumor necrosis factor-α (TNF-α) and IL-1β levels. Based on the results of a biological prediction website, microRNA.org, Kelch-like ECH-associated protein 1 (Keap1) was predicted to be one of the target genes of miR-125b-5p, which was verified by a dual-luciferase reporter gene assay. Western blot results in vitro and in vivo showed that miR-125b-5p could decrease the expression of Keap1 and cleaved caspase-3 while upregulating the expression of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and heme oxygenase-1(HO-1).

Conclusion

Upregulation of miR-125b-5p can alleviate acute liver failure by regulating the Keap1/Nrf2/HO-1 pathway, and regulation of miR-125b-5p may serve as an alternative intervention for liver failure.

Roles of Non-Coding RNAs in Primary Biliary Cholangitis

Primary biliary cholangitis (PBC) is an autoimmune-mediated chronic cholestatic liver disease, fatigue, and skin itching are the most common clinical symptoms. Its main pathological feature is the progressive damage and destruction of bile duct epithelial cells. Non-coding RNA (NcRNA, mainly including microRNA, long non-coding RNA and circular RNA) plays a role in the pathological and biological processes of various diseases, especially autoimmune diseases. Many validated ncRNAs are expected to be biomarkers for the diagnosis or treatment of PBC. This review will elucidate the pathogenesis of PBC and help to identify potential ncRNA biomarkers for PBC.

Construction of a competing endogenous RNA network to analyse glucose-6-phosphate dehydrogenase dysregulation in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a common malignant tumour with high rates of morbidity and mortality worldwide. Therefore, it is of great significance to find new molecular markers for HCC diagnosis and treatment. G6PD is known to be dysregulated in a variety of tumours. In addition, the ceRNA network plays a crucial role in the occurrence and development of HCC. However, the mechanism by which the ceRNA network regulates G6PD in HCC remains unclear. We used TCGA-LIHC data to analyse the possibility of using G6PD as an independent prognostic marker. Univariate Cox proportional hazards regression, multivariate Cox proportional hazards regression, and receiver operating characteristic curve analysis were used to analyse the influence of G6PD overexpression on the prognosis of HCC patients. We also analysed the biological function of G6PD, its effect on the immune microenvironment, and drug sensitivity. Finally, we constructed a ceRNA network of lncRNAs/miR-122-5p/G6PD to explore the regulatory mechanism of G6PD. G6PD was highly expressed in HCC, was related to pathological stage and poor prognosis, and could be used as an independent prognostic indicator of HCC. The expression of G6PD was closely related to the immune microenvironment of HCC. In addition, the expression of G6PD in HCC could be regulated by the ceRNA network. Therefore, G6PD can be used as an immunotherapy target to improve the survival and prognosis of HCC patients, and the ceRNA regulatory network of G6PD has potential diagnostic and therapeutic value for HCC.

Sevoflurane attenuates hepatic ischemia reperfusion injury by the miR-122/Nrf2 pathway

Background

Sevoflurane can protect organs from ischemia-reperfusion (IR) injury, but the mechanism is still unclear. MicroRNA-122 (miR-122) is a liver-specific microRNA (miRNA) and regulates liver function. Therefore, this study aims to elucidate the relationship between the protective effect of sevoflurane and miR-122 in liver IR injury.

Methods

Wistar rats were divided into the following groups: sham, IR, IR + sevoflurane, IR + miR-122 antagomir, and IR + miR-122 antagomir + sevoflurane. Hematoxylin and eosin (H&E) staining and Suzuki score were used to evaluate the pathological damage of the liver. The levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-10 in the serum and the levels of malondialdehyde (MDA), superoxide dismutase (SOD), and nitric oxide (NO) in the liver homogenate supernatant were detected by using the corresponding kit. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) and flow cytometry was applied to evaluate the apoptosis of liver tissues. The expression of nuclear factor E2-related factor 2 (Nrf2), miR-122, p53, and HO-1 in liver tissue was evaluated by using immunohistochemistry, qRT-PCR, and western blot as needed.

Results

Compared to the IR group, the sevoflurane post-treatment or miR-122 antagomir groups showed improved liver injury, decreased Suzuki score, inhibited the levels of AST, ALT, LDH, MDA, NO, TNF-α, IL-1β, and IL-6, increased levels of SOD, IL-10, and inhibited hepatocyte apoptosis. Regarding the molecular mechanism, sevoflurane post-treatment fostered the expression of HO-1, promoted the transport of Nrf2 from cytoplasm to the nucleus, and decreased the expression of miR-122 and p53. The combined use of miR-122 antagomir and sevoflurane enhanced the protective effect of miR-122 antagomir in liver injury in IR rats.

Conclusions

Sevoflurane protected the liver from IR damage by regulating the miR-122/Nrf2/HO-1 pathway.

Highly Sensitive Detection of Elevated Exosomal miR-122 Levels in Radiation Injury and Hepatic Inflammation Using an Aptamer-Functionalized SERS-Sandwich Assay

Radiation-induced organ injury is one of the major fallouts noticed during radiotherapy treatment of malignancies and other detrimental radiation exposures. MicroRNA (miRNA), which is involved in multiple critical cellular processes, is released from the cells of damaged organs in cellular vesicles, commonly known as exosomes. Specifically, exosomal miR-122 is reported to be actively involved in radiation-actuated rectal and hepatic injuries or inflammation. In this work, we developed a surface-enhanced Raman spectroscopy (SERS) assay for the quantitative and targeted detection of exosomal miR-122 in mice after drug/radiation treatments. In particular, an aptamer-functionalized magnetic capturing element and Au shell nanoparticle (NP)-based SERS tags were utilized, which upon recognition of the target miRNA constituted a "sandwich" formation, with which an 8 fM limit of detection (LOD) could be achieved. Using this SERS assay, we further found that radiation injury led to the elevated expression of exosomal miR-122 in mice at 4 h postirradiation, confirmed by the quantitative real-time PCR method. It was demonstrated that the drug-induced hepatic inflammation could also be assessed via detecting miR-122 using this SERS method. As such, this work has demonstrated the achievement of a highly selective and sensitive probe of exosomal miRNA, which may thus open a gateway for promising usage in drug/radiation-induced inflammation.

Hepatocyte-Specific Deficiency of BAP31 Amplified Acetaminophen-Induced Hepatotoxicity via Attenuating Nrf2 Signaling Activation in Mice

Liver-specific deficiency of B-cell receptor-associated protein 31 knockout mice (BAP31-LKO) and the littermates were injected with acetaminophen (APAP), markers of liver injury, and the potential molecular mechanisms were determined. In response to APAP overdose, serum aspartate aminotransferase and alanine aminotransferase levels were increased in BAP31-LKO mice than in wild-type controls, accompanied by enhanced liver necrosis. APAP-induced apoptosis and mortality were increased. Hepatic glutathione was decreased (1.60 ± 0.31 μmol/g tissue in WT mice vs. 0.85 ± 0.14 μmol/g tissue in BAP31-LKO mice at 6 h, p < 0.05), along with reduced glutathione reductase activity and superoxide dismutase; while malondialdehyde was significantly induced (0.41 ± 0.03 nmol/mg tissue in WT mice vs. 0.50 ± 0.05 nmol/mg tissue in BAP31-LKO mice for 6 h, p < 0.05). JNK signaling activation and APAP-induced hepatic inflammation were increased in BAP31-LKO mice. The mechanism research revealed that BAP31-deficiency decreased Nrf2 mRNA stability (half-life of Nrf2 mRNA decreased from ~1.3 h to ~40 min) and miR-223 expression, led to reduced nuclear factor erythroid 2-related factor 2 (Nrf2) signaling activation and antioxidant genes induction. BAP31-deficiency decreased mitochondrial membrane potentials, reduced mitochondria-related genes expression, and resulted in mitochondrial dysfunction in the liver. Conclusions: BAP31-deficiency reduced the antioxidant response and Nrf2 signaling activation via reducing Nrf2 mRNA stabilization, enhanced JNK signaling activation, hepatic inflammation, and apoptosis, amplified APAP-induced hepatotoxicity in mice.

miR-122-5p downregulation attenuates lipopolysaccharide-induced acute lung injury by targeting IL1RN

MicroRNAs (miRs) and inflammatory cytokines can induce acute lung injury (ALI), which can develop into acute respiratory distress syndrome in severe cases. Previous research has revealed that miR-122-5p participates in the development of ALI, and that its expression is positively associated with ALI. However, the mechanism by which miR-122-5p contributes to ALI remains to be determined. In the current study, TargetScan and dual luciferase reporter gene assays were used to confirm that IL-1 receptor antagonist (IL1RN) was a target of miR-122-5p. Subsequently, by referring to previous literature, a lipopolysaccharide (LPS)-induced ALI cell model was established. A549 cells were transfected with mimic control or miR-122-5p mimics for 24 h, and 10 µg LPS was used to treat the transfected cells for 12 h. The results revealed that miR-122-5p mimics decreased cell viability and promoted apoptosis. Lactate dehydrogenase (LDH) release assays indicated that miR-122-5p mimics increased LDH release. ELISA demonstrated that miR-122-5p mimics promoted TNF-α, IL-1β and IL-6 expression levels. A549 cells were transfected with inhibitor control, miR-122-5p inhibitor, miR-122-5p inhibitor + control-small interfering (si)RNA or miR-122-5p inhibitor + IL1RN-siRNA for 24 h, after which the cells were treated with 10 µg LPS for 12 h. The results revealed that the effects of the miR-122-5p inhibitor were the opposite of those of the miR-122-5p mimic. All the effects of miR-122-5p inhibitor on LPS-treated A549 cells were significantly reversed by IL1RN-siRNA. Overall, the results highlighted miR-122-5p as a potential novel target for the treatment of ALI.

Targeting epigenetics and lncRNAs in liver disease: From mechanisms to therapeutics

Early onset and progression of liver diseases can be driven by aberrant transcriptional regulation. Different transcriptional regulation processes, such as RNA/DNA methylation, histone modification, and ncRNA-mediated targeting, can regulate biological processes in healthy cells, as well also under various pathological conditions, especially liver disease. Numerous studies over the past decades have demonstrated that liver disease has a strong epigenetic component. Therefore, the epigenetic basis of liver disease has challenged our knowledge of epigenetics, and epigenetics field has undergone an important transformation: from a biological phenomenon to an emerging focus of disease research. Furthermore, inhibitors of different epigenetic regulators, such as m⁶A-related factors, are being explored as potential candidates for preventing and treating liver diseases. In the present review, we summarize and discuss the current knowledge of five distinct but interconnected and interdependent epigenetic processes in the context of hepatic diseases: RNA methylation, DNA methylation, histone methylation, miRNAs, and lncRNAs. Finally, we discuss the potential therapeutic implications and future challenges and ongoing research in the field. Our review also provides a perspective for identifying therapeutic targets and new hepatic biomarkers of liver disease, bringing precision research and disease therapy to the modern era of epigenetics.