MiR-124 protects human hepatic L02 cells from H2O2-induced apoptosis by targeting Rab38 gene

Non-coding RNAs: The potential biomarker or therapeutic target in hepatic ischemia-reperfusion injury

Hepatic ischemia-reperfusion injury (HIRI) is the major complication of liver surgery and liver transplantation, that may increase the postoperative morbidity, mortality, tumor progression, and metastasis. The underlying mechanisms have been extensively investigated in recent years. Among these, oxidative stress, inflammatory responses, immunoreactions, and cell death are the most studied. Non-coding RNAs (ncRNAs) are defined as the RNAs that do not encode proteins, but can regulate gene expressions. In recent years, ncRNAs have emerged as research hotspots for various diseases. During the progression of HIRI, ncRNAs are differentially expressed, while these dysregulations of ncRNAs, in turn, have been verified to be related to the above pathological processes involved in HIRI. ncRNAs mainly contain microRNAs, long ncRNAs, and circular RNAs, some of which have been reported as biomarkers for early diagnosis or assessment of liver damage severity, and as therapeutic targets to attenuate HIRI. Here, we briefly summarize the common pathophysiology of HIRI, describe the current knowledge of ncRNAs involved in HIRI in animal and human studies, and discuss the potential of ncRNA-targeted therapeutic strategies. Given the scarcity of clinical trials, there is still a long way to go from pre-clinical to clinical application, and further studies are needed to uncover their potential as therapeutic targets.

Research progress of lncRNA and miRNA in hepatic ischemia-reperfusion injury

BACKGROUND

Hepatic ischemia-reperfusion injury (HIRI) is a common complication of liver surgeries, such as hepatectomy and liver transplantation. In recent years, several non-coding RNAs (ncRNAs) including long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) have been identified as factors involved in the pathological progression of HIRI. In this review, we summarized the latest research on lncRNAs, miRNAs and the lncRNA-miRNA regulatory networks in HIRI.

DATA SOURCES

The PubMed and Web of Science databases were searched for articles published up to December 2021 using the following keywords: "hepatic ischemia-reperfusion injury", "lncRNA", "long non-coding RNA", "miRNA" and "microRNA". The bibliography of the selected articles was manually screened to identify additional studies.

RESULTS

The mechanism of HIRI is complex, and involves multiple lncRNAs and miRNAs. The roles of lncRNAs such as AK139328, CCAT1, MALAT1, TUG1 and NEAT1 have been established in HIRI. In addition, numerous miRNAs are associated with apoptosis, autophagy, oxidative stress and cellular inflammation that accompany HIRI pathogenesis. Based on the literature, we conclude that four lncRNA-miRNA regulatory networks mediate the pathological progression of HIRI. Furthermore, the expression levels of some lncRNAs and miRNAs undergo significant changes during the progression of HIRI, and thus are potential prognostic markers and therapeutic targets.

CONCLUSIONS

Complex lncRNA-miRNA-mRNA networks regulate HIRI progression through mutual activation and antagonism. It is necessary to screen for more HIRI-associated lncRNAs and miRNAs in order to identify novel therapeutic targets.

Hepatoprotective effects of sevoflurane against hepatic ischemia-reperfusion injury by regulating microRNA-124-3p-mediated TRAF3/CREB axis

The purpose of the present study is to define the role of sevoflurane (SEV) in hepatic ischemia-reperfusion (I/R) injury as well as its underlying mechanism. Initially, hepatic I/R animal models and I/R hepatocyte models were established in C57BL/6 mice and normal mouse hepatocytes (BNL CL.2) after SEV preconditioning, respectively, followed by detection of microRNA-124-3p (miR-124-3p), TRAF3, and CREB expression by RT-qPCR and Western blot analysis. In addition, miR-124-3p, TRAF3 and CREB expression in hepatocytes was altered to identify their roles in modulating the levels of glutathione transferase (GST), aspartate aminotransferase (AST) and alanine aminotransferase (ALT), and inflammation-related factors and hepatocyte apoptosis by ELISA and flow cytometry respectively. The effects of SEV on the miR-124-3p/TRAF3/CREB axis were also verified in vitro and in vivo. IP assay was performed to verify the effect of TRAF3 on CREB ubiquitination in BNL CL.2 cells, and the cycloheximide (CHX) intervention experiment to detect the stability of CREB protein. SEV augmented the miR-124-3p expression in I/R animal and cell models. Moreover, SEV was observed to suppress I/R-induced liver damage, GST, ALT, and AST levels, hepatocyte apoptosis and inflammation. Overexpression of miR-124-3p resulted in alleviation of hepatic I/R injury, which was countered by TRAF3 overexpression. miR-124-3p targeted TRAF3, while TRAF3 promoted CREB ubiquitination and reduced protein stability of CREB. SEV could impede I/R-induced liver damage, GST, ALT, and AST levels, hepatocyte apoptosis and inflammation via mediation of the miR-124-3p/TRAF3/CREB axis in vitro and in vivo. Collectively, SEV may upregulate miR-124-3p to inhibit TRAF3 expression, thereby reducing the ubiquitination and degradation of CREB, alleviating hepatic I/R injury.

YAP-Dependent Induction of CD47-Enriched Extracellular Vesicles Inhibits Dendritic Cell Activation and Ameliorates Hepatic Ischemia-Reperfusion Injury

Hepatic ischemia-reperfusion injury (IRI) is the most common cause of liver damage leading to surgical failures in hepatectomy and liver transplantation. Extensive inflammatory reactions and oxidative responses are reported to be the major processes exacerbating IRI. The involvement of Yes-associated protein (YAP) in either process has been suggested, but the role and mechanism of YAP in IRI remain unclear. In this study, we constructed hepatocyte-specific YAP knockout (YAP-HKO) mice and induced a hepatic IRI model. Surprisingly, the amount of serum EVs decreased in YAP-HKO compared to WT mice during hepatic IRI. Then, we found that the activation of YAP increased EV secretion through F-actin by increasing membrane formation, while inhibiting the fusion of multivesicular body (MVB) and lysosomes in hepatocytes. Further, to explore the essential elements of YAP-induced EVs, we applied mass spectrometry and noticed CD47 was among the top targets highly expressed on hepatocyte-derived EVs. Thus, we enriched CD47⁺ EVs by microbeads and applied the isolated CD47⁺ EVs on IRI mice. We found ameliorated IRI symptoms after CD47⁺ EV treatment in these mice, and CD47⁺ EVs bound to CD172α on the surface of dendritic cells (DCs), which inhibited DC activation and the cascade of inflammatory responses. Our data showed that CD47-enriched EVs were released in a YAP-dependent manner by hepatocytes, which could inhibit DC activation and contribute to the amelioration of hepatic IRI. CD47⁺ EVs could be a potential strategy for treating hepatic IRI.

Total Glucosides of Paeony Alleviate Cell Apoptosis and Inflammation by Targeting the Long Noncoding RNA XIST/MicroRNA-124-3p/ITGB1 Axis in Renal Ischemia/Reperfusion Injury

Objective

Renal ischemia/reperfusion injury (RI/RI) is the main cause of acute kidney injury. Total glucosides of paeony (TGP) are a traditional Chinese medicine. This study was aimed at exploring the role of TGP in RI/RI and its underlying mechanism of action.

Methods

Rat RI/RI models were constructed by surgical operation. Serum creatinine (Scr) and blood urea nitrogen (BUN) were used to evaluate renal function. The levels of proinflammatory cytokines were detected by ELISA. RI/RI was simulated by hypoxia/reoxygenation (H/R) treatment in renal cells in vitro. The lncRNA XIST (XIST) expression was analyzed by qRT-PCR. Then, the viability and apoptosis of renal cells were detected by MTT and flow cytometry assay. Additionally, dual-luciferase reporter assay was used to determine the interactions among XIST, microRNA-124-3p (miR-124-3p), and ITGB1.

Results

TGP improved renal function and inhibited inflammatory responses after RI/RI. XIST expression was highly expressed in rat RI/RI models and H/R-treated renal cells, whereas treatment with TGP downregulated the XIST expression. Additionally, TGP increased viability and attenuated apoptosis and inflammation of H/R-treated renal cells via inhibiting XIST. Moreover, XIST was competitively bound to miR-124-3p, and ITGB1 was a target of miR-124-3p. miR-124-3p overexpression or ITGB1 inhibition rescued the reduction effect on viability and mitigated the promoting effects on cell apoptosis and inflammation caused by XIST overexpression in H/R-treated renal cells.

Conclusions

In vivo, TGP attenuated renal dysfunction and inflammation in RI/RI rats. In vitro, TGP inhibited XIST expression to modulate the miR-124-3p/ITGB1 axis, alleviating the apoptosis and inflammation of H/R-treated renal cells.

miR-124/IRE-1α affects renal ischemia/reperfusion injury by regulating endoplasmic reticulum stress in renal tubular epithelial cells

Acute kidney injury (AKI) refers to a clinical syndrome that occurs as a result of a rapid decline in renal function caused by multiple factors. Renal ischemia/reperfusion (I/R) injury is one of the main causes of AKI and has a high incidence and mortality. However, the specific pathogenesis of renal I/R injury is still unclear. In recent years, a major breakthrough has been made in the study of endoplasmic reticulum stress (ERS)-mediated apoptosis in I/R injury. It has been reported that miRNAs play protective roles in ischemic/reperfused organs, but the molecular mechanisms have not been investigated deeply. In this study, the renal I/R mouse model was used to explore the roles of miR-124 in ERS and in renal I/R injury. The western blot results showed that the expression levels of ERS-related proteins IRE-1α, XBP-1, and glucose-regulated protein 78 (GRP78) were significantly increased in the I/R model group when compared with those in the control group. Meanwhile, qPCR results showed that miR-124 expression was decreased in the I/R injury model, and overexpression of miR-124 using miR-124 mimics effectively reduced the expression of ERS-related proteins and alleviated renal I/R injury. In addition, luciferase reporter assay was performed, and the results showed that IRE-1α and miR-124 may have direct interaction. In conclusion, our data indicated that miR-124 was a negative regulator of ERS via binding to IRE-1α, ultimately conferring its protective effect on the kidney, which demonstrates the regulatory mechanism of miR-124 in renal I/R injury and provides new ideas and methods for the prevention and treatment of renal I/R injury.

Retracted: Knockdown of long noncoding RNA GAS5 attenuates H2 O2 -induced damage in retinal ganglion cells through upregulating miR-124: Potential role in traumatic brain injury

BACKGROUND

Optic nerve injury is one of the most common and serious complications in traumatic brain injury (TBI). Alleviating degree of optic nerve injury is important to cure of TBI. This study explored the role of long noncoding RNA (lncRNA) GAS5 in mice retinal ganglion cells (RGCs) suffered to H₂ O ₂ injury.

METHODS

Primary RGC (PRGCs) were treated with H₂ O ₂ to simulate an in vitro oxidation stress model. LncRNA GAS5 and miR-124 expressions were knocked down by cell transfection with short-hairpin RNA against GAS5 and miR-124 inhibitor, and the transfection efficiency was determined by qRT-PCR. Cell viability, apoptotic cell rate, and production of reactive oxygen species (ROS) was analyzed by CCK-8 assay, PI/FITC-Annexin V method, and DCFH-DA fluorometric assay. Cell apoptosis-associated proteins as well as activations of JAK/STAT3 signaling and JNK signaling were analyzed by Western blot.

RESULTS

H₂ O ₂ treatment-induced cell injury was inhibited by lncRNA GAS5 silence. Specifically, knockdown of GAS5 improved viability of primary PRGCs, inhibited apoptosis, decreased ROS expression, increased antiapoptosis proteins' expressions, and decreased proapoptosis proteins' expressions. It was also found that miR-124 inhibitor treatment impaired the cell protective effect of GAS5 silence, indicating low level of GAS5 protected PRGCs via upregulating miR-124. GAS5 silence might exert cytoprotection effect via activating JAK/STAT3 signaling pathway and inhibiting activation of JNK signaling pathway.

CONCLUSION

Knocking down lncRNA GAS5 alleviated H₂ O ₂ -induced injury in PRGCs via upregulation of miR-124, which might dependent on activation of JAK/STAT3 signaling pathway and inhibition of JNK signaling pathway.

MicroRNA-124 expression in the brains of rats during early cerebral ischemia and reperfusion injury is associated with cell apoptosis involving STAT3

Cerebral ischemia and reperfusion injury is a cause of death and disability in adults. MicroRNA-124 possesses protective effects against apoptosis in cerebral ischemia and reperfusion. To provide insights into the diagnosis and treatment of cerebral ischemia and reperfusion injury, the dynamic changes of microRNA-124 expression during the early stage of cerebral ischemia and reperfusion injury in rats was investigated by quantitative polymerase chain reaction. To elucidate the association between the dynamic expression of microRNA-124 and apoptosis, the expression of proteins associated with apoptosis, including caspase-3, apoptosis regulator Bcl-2 (Bcl-2) and apoptosis regulator Bax (Bax) was analyzed by immunohistochemistry and western blot analyses. As signal transducer and activator of transcription 3 (STAT3) is involved in cell apoptosis and associated with Bcl-2, the protein expression of STAT3 and its active form, phosphorylated (p-)STAT3, were analyzed by western blot analysis. The expression of microRNA-124 increased and the maximum value appeared 12 h after reperfusion. Similarly, the expression of Bcl-2 also peaked 12 h after reperfusion, however the expression of caspase-3 and Bax continued to increase after the 12 h time point. These results indicate that the expression of microRNA-124 is closely associated with Bcl-2 and serves a protective role, inhibiting apoptosis. As the upstream regulator of Bcl-2, the expression of p-STAT3 was in accordance with Bcl-2 expression and peaked 12 h after reperfusion. By contrast, STAT3 was downregulated and the minimum level of STAT3 protein was reached 12 h after reperfusion. In summary, during the early stage of cerebral ischemia and reperfusion, the dynamic expression of microRNA-124 exhibited protective effects through the inhibition of apoptosis via anti-apoptotic proteins Bcl-2 and STAT3. Conversely, caspase-3 and Bax maintain apoptosis. The present study provides evidence to aid in the understanding of cerebral ischemia and reperfusion injury and develops methods of diagnosis and therapy of this condition.

IMM-H004, a Novel Coumarin Derivative Compound, Inhibits H2O2-Induced Neurotoxicity via Antioxidant and Antiapoptosis in PC12 Cells

IMM-H004 [7-hydroxy-5-methoxy-4-methyl-3-(4-methylpiperazin-1-yl)-coumarin] is a novel derivative of coumarin, which played neuroprotective roles in brain ischemia in rats in previous studies. Although antiapoptosis and improving synapsis structure were proved, the effects and mechanisms of IMM-H004 in brain ischemia need further study. In this paper, the effect of IMM-H004 on H₂O₂-induced neurotoxicity in pheochromocytoma (PC12) cells was researched. Morphological observation, MTT method and PI/Hoechst staining were used to indicate cell viability and apoptosis. JC-1 and DCFH-DA were used to test mitochondrial membrane potential (MMP) and reactive oxygen species (ROS), respectively. The antioxidative activity was detected by Glutathione (GSH) and Total Antioxidant Capacity (TAC) Assay kits. Western blot was used to test apoptosis related proteins. Our results showed that treatment with 1-10 μM IMM-H004 markedly increased cell viability and decreased cell apoptosis induced by H₂O₂. Moreover, 1-10 μM IMM-H004 could enhance MMP and protect mitochondrial function. 1-10 μM IMM-H004 also could lower the ROS and raise the GSH and TAC level. Furthermore, 1-10 μM IMM-H004 could decrease the ratio of Bax/Bcl-2 and increase the ratio of p-AKT/AKT, which were related to apoptosis and survival. All these indicated that IMM-H004 protects PC12 cells against H₂O₂-induced neurotoxicity. Antioxidative and antiapoptosis may be the mechanisms of IMM-H004 in brain ischemia. These studies indicate that IMM-H004 might be a potential drug for treatment brain ischemia.

Novel Targets for Treating Ischemia-Reperfusion Injury in the Liver

Liver ischemia-reperfusion injury (IRI) is a major complication of hemorrhagic shock, liver transplantation, and other liver surgeries. It is one of the leading causes for post-surgery hepatic dysfunction, always leading to morbidity and mortality. Several strategies, such as low-temperature reperfusion and ischemic preconditioning, are useful for ameliorating liver IRI in animal models. However, these methods are difficult to perform in clinical surgeries. It has been reported that the activation of peroxisome proliferator activated receptor gamma (PPARγ) protects the liver against IRI, but with unidentified direct target gene(s) and unclear mechanism(s). Recently, FAM3A, a direct target gene of PPARγ, had been shown to mediate PPARγ’s protective effects in liver IRI. Moreover, noncoding RNAs, including LncRNAs and miRNAs, had also been reported to play important roles in the process of hepatic IRI. This review briefly discussed the roles and mechanisms of several classes of important molecules, including PPARγ, FAM3A, miRNAs, and LncRNAs, in liver IRI. In particular, oral administration of PPARγ agonists before liver surgery or liver transplantation to activate hepatic FAM3A pathways holds great promise for attenuating human liver IRI.

miR-494 up-regulates the PI3K/Akt pathway via targetting PTEN and attenuates hepatic ischemia/reperfusion injury in a rat model

A rat HIRI model was constructed and treated with an intraperitoneal injection of agomir-miR-494 or agomir-NC (negative control) for 7 days after the surgery. The pathophysiological changes in sham-operated rats, HIRI, HIRI + agomir-miR-494, and HIRI + agomir-NC were compared. The effect of miR-494 was also assessed in an H₂O₂-induced apoptosis model. Hepatic AML12 cells were transfected with mimics NC or miR-494 mimics, followed by 6-h H₂O₂ treatment. Cell proliferation and apoptosis were detected by CCK8 assay and flow cytometry, respectively. Further, the miR-494 target gene was identified by luciferase reporter assay, and verified both in vitro and in vivo experiments. The activity of AKT pathway was further analyzed in vivo by Western blot. HIRI + agomir-miR-494 rats exhibited significantly higher miR-494 expression, lower serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), and glutamate dehydrogenase (GLDH) level, lower hepatic MDA, TOA, and OSI, alleviated hepatic necrosis, reduced hepatocyte apoptosis, and decreased expression of apoptosis-related proteins, when compared with HIRI + agomir-NC rats (P<0.05 or 0.01). After H₂O₂ treatment, AML-12 cells transfected with miR-494 mimics had significantly higher proliferation and lower apoptosis rate compared with mimics NC group (P<0.01). PTEN was identified as an miR-494 target gene. PTEN expression was significantly down-regulated in AML12 cells transfected with miR-494 mimics, and was up-regulated by treatment of miR-494 inhibitor (P<0.01). Moreover, HIRI + agomir-miR-494 rats exhibited significantly lower PTEN expression, and higher p-AKT, p-mTOR, and p-p70S6K levels compared with HIRI + agomir-NC rats. Therefore, miR-494 protected rats against hepatic ischemia/reperfusion (I/R) injury through down-regulating its downstream target gene PTEN, leading to the activation of PI3K/AKT signaling pathway.

miR-706 inhibits the oxidative stress-induced activation of PKCα/TAOK1 in liver fibrogenesis

Oxidative stress induces the activation of liver fibrogenic cells (myofibroblasts), thus promoting the expression of fibrosis-related genes, leading to hepatic fibrogenesis. MicroRNAs (miRNAs) are a new class of small RNAs ~18–25 nucleotides in length involved in post-transcriptional regulation of gene expression. Wound-healing and remodeling processes in liver fibrosis have been associated with changes in hepatic miRNA expression. However, the role of miR-706 in liver fibrogenesis is currently unknown. In the present study, we show that miR-706 is abundantly expressed in hepatocytes. Moreover, oxidative stress leads to a significant downregulation of miR-706, and the further reintroduction of miR-706 inhibits oxidative stress-induced expression of fibrosis-related markers such as α-SMA. Subsequent studies revealed that miR-706 directly inhibits PKCα and TAOK1 expression via binding to the 3′-untranslated region, preventing epithelial mesenchymal transition. In vivo studies showed that intravenous injection of miR-706 agomir successfully increases hepatic miR-706 and decreases α-SMA, PKCα, and TAOK1 protein levels in livers of carbon tetrachloride (CCl₄)-treated mice. In summary, this study reveals a protective role for miR-706 by blocking the oxidative stress-induced activation of PKCα/TAOK1. Our results further identify a major implication for miR-706 in preventing hepatic fibrogenesis and suggest that miR-706 may be a suitable molecular target for anti-fibrosis therapy.

Hepatoprotective effect of flavonoids from Cirsium japonicum DC on hepatotoxicity in comparison with silymarin

Cirsium japonicum DC is a perennial plant that is widely distributed throughout China. Flavonoids are the major active constituents of C. japonicum, which has been reported to possess many bioactivities. This study was designed to investigate the protective effects of flavonoids from C. japonicum against liver injury using carbon tetrachloride (CCl4)-induced hepatocyte injury, with silymarin as a positive control. Silymarin is a mixture of flavonoids from Silybum marianum, a traditional European food plant with clear hepatoprotective effects. The results indicated that the pretreatment with C. japonicum flavonoids could significantly reverse CCl4-induced L02 cell viability decrease similarly to silymarin. Analysis of flavonoids of C. japonicum and silymarin by HPLC showed that these two mixtures may contain one common component, which may be the major active ingredient responsible for their hepatoprotective effects. It is concluded that C. japonicum could be developed into functional foods with hepatoprotective efficacy, similarly to S. marianum.

MicroRNAs as Signaling Mediators and Biomarkers of Drug- and Chemical-Induced Liver Injury

Drug-induced liver injury (DILI) is major problem for both the drug industry and for clinicians. There are two basic categories of DILI: intrinsic and idiosyncratic. The former is the chief cause of acute liver failure in several developed countries, while the latter is the most common reason for post-marketing drug withdrawal and a major reason for failure to approve new drugs in the U.S. Although considerably more progress has been made in the study of intrinsic DILI, our understanding of both forms of drug hepatotoxicity remains incomplete. Recent work involving microRNAs (miRNAs) has advanced our knowledge of DILI in two ways: (1) possible roles of miRNAs in the pathophysiological mechanisms of DILI have been identified, and (2) circulating miRNA profiles have shown promise for the detection and diagnosis of DILI in clinical settings. The purpose of this review is to summarize major findings in these two areas of research. Taken together, exciting progress has been made in the study of miRNAs in DILI. Possible mechanisms through which miRNA species contribute to the basic mechanisms of DILI are beginning to emerge, and new miRNA-based biomarkers have the potential to greatly improve diagnosis of liver injury and prediction of patient outcomes.