MicroRNA-182-5p Ameliorates Liver Ischemia-Reperfusion Injury by Suppressing Toll-Like Receptor 4

Targeting NF-κB in Hepatic Ischemia-Reperfusion Alleviation: from Signaling Networks to Therapeutic Targeting

Hepatic ischemia-reperfusion injury (HIRI) is a major complication of liver trauma, resection, and transplantation that can lead to liver dysfunction and failure. Scholars have proposed a variety of liver protection methods aimed at reducing ischemia-reperfusion damage, but there is still a lack of effective treatment methods, which urgently needs to find new effective treatment methods for patients. Many studies have reported that signaling pathway plays a key role in HIRI pathological process and liver function recovery mechanism, among which nuclear transfer factor-κB (NF-κB) signaling pathway is one of the signal transduction closely related to disease. NF-κB pathway is closely related to HIRI pathologic process, and inhibition of this pathway can delay oxidative stress, inflammatory response, cell death, and mitochondrial dysfunction. In addition, NF-κB can also interact with PI3K/Akt, MAPK, and Nrf2 signaling pathways to participate in HIRI regulation. Based on the role of NF-κB pathway in HIRI, it may be a potential target pathway for HIRI. This review emphasizes the role of inhibiting the NF-κB signaling pathway in oxidative stress, inflammatory response, cell death, and mitochondrial dysfunction in HIRI, as well as the effects of related drugs or inhibitors targeting NF-κB on HIRI. The objective of this review is to elucidate the role and mechanism of NF-κB pathway in HIRI, emphasize the important role of NF-κB pathway in the prevention and treatment of HIRI, and provide a theoretical basis for the target NF-κB pathway as a therapy for HIRI.

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.

The emerging role of MicroRNA-182 in tumorigenesis; a promising therapeutic target

A wide range of studies have indicated that microRNAs (miRNAs), a type of small single-stranded regulatory RNAs, are dysregulated in a different variety of human cancers. Therefore, they are expected to play important roles in tumorigenesis by functioning as oncogenic (oncomiRs) or tumor-suppressive miRNAs. Subsequently, their potential as diagnostic and therapeutic targets for malignancies has attracted attention in recent years. In particular, studies have revealed the aberrant expression of miR-182 through tumorigenesis and its important roles in various aspects of malignancies, including proliferation, metastasis, and chemoresistance. Accumulating reports have illustrated that miR-182, as a dual-role regulator, directly or indirectly regulates the expression of a wide range of genes and modulates the activity of various signaling pathways involved in tumor progression, such as JAK / STAT3, Wnt / β-catenin, TGF-β, and P13K / AKT. Therefore, considering the high therapeutic and diagnostic potential of miR-182, this review aims to point out the effects of miR-182 dysregulation on the signaling pathways involved in tumorigenesis.

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.

Molecular Mechanisms of Ischaemia-Reperfusion Injury and Regeneration in the Liver-Shock and Surgery-Associated Changes

Hepatic ischemia-reperfusion injury (IRI) represents a major challenge during liver surgery, liver preservation for transplantation, and can cause hemorrhagic shock with severe hypoxemia and trauma. The reduction of blood supply with a concomitant deficit in oxygen delivery initiates various molecular mechanisms involving the innate and adaptive immune response, alterations in gene transcription, induction of cell death programs, and changes in metabolic state and vascular function. Hepatic IRI is a major cause of morbidity and mortality, and is associated with an increased risk for tumor growth and recurrence after oncologic surgery for primary and secondary hepatobiliary malignancies. Therapeutic strategies to prevent or treat hepatic IRI have been investigated in animal models but, for the most part, have failed to provide a protective effect in a clinical setting. This review focuses on the molecular mechanisms underlying hepatic IRI and regeneration, as well as its clinical implications. A better understanding of this complex and highly dynamic process may allow for the development of innovative therapeutic approaches and optimize patient outcomes.

MiR-182-5p Mediated by Exosomes Derived From Bone Marrow Mesenchymal Stem Cell Attenuates Inflammatory Responses by Targeting TLR4 in a Mouse Model of Myocardial Infraction

Exosomes derived from mesenchymal stem cells (MSCs) could protect against myocardial infarction (MI). TLR4 is reported to play an important role in MI, while microRNA-182-5p (miR-182-5p) negatively regulates TLR4 expression. Therefore, we hypothesize that MSCs-derived exosomes overexpressing miR-182-5p may have beneficial effects on MI. We generated bone marrow mesenchymal stem cells (BM-MSCs) and overexpressed miR-182-5p in these cells for exosome isolation. H₂O₂-stimulated neonatal mouse ventricle myocytes (NMVMs) and MI mouse model were employed, which were subjected to exosome treatment. The expression of inflammatory factors, heart function, and TLR4 signaling pathway activation were monitored. It was found that miR-182-5p decreased TLR4 expression in BM-MSCs and NMVMs. Administration of exosomes overexpressing miR-182-5p to H₂O₂-stimulated NMVMs enhanced cell viability and suppressed the expression of inflammatory cytokines. In addition, they promoted heart function, suppressed inflammatory responses, and de-activated TLR4/NF-κB signaling pathway in MI mice. In conclusion, miR-182-5p transferred by the exosomes derived from BM-MSCs protected against MI-induced impairments by targeting TLR4.

Mesenchymal stem cell-derived exosomal microRNA-182-5p alleviates myocardial ischemia/reperfusion injury by targeting GSDMD in mice

Recent evidence indicates that exosomes derived from mesenchymal stem cells (MSCs) confer protective effects against myocardial ischemia/reperfusion (I/R) injury. Exosomes are carriers of potentially protective endogenous molecules, including microRNAs (miRNAs/miRs). The current study set out to test the effects of transferring miR-182-5p from MSC-derived exosomes into myocardial cells on myocardial I/R injury. First, an I/R mouse model was developed by left anterior descending coronary artery occlusion, and myocardial cells were exposed to hypoxia/reoxygenation (H/R) for in vitro I/R model establishment. Loss- and gain-of-function experiments of miR-182-5p and GSDMD were conducted to explore the effects of miR-182-5p via MSC-derived exosomes on cell pyroptosis and viability. GSDMD was robustly expressed in I/R-injured myocardial tissues and H/R-exposed myocardial cells. GSDMD upregulation promoted H/R-induced myocardial cell pyroptosis and reduced viability, corresponding to increased lactate dehydrogenase release, reactive oxygen species production, and pyroptosis. A luciferase assay demonstrated GSDMD as a target of miR-182-5p. In addition, exosomal miR-182-5p was found to diminish GSDMD-dependent cell pyroptosis and inflammation induced by H/R. Furthermore, MSC-derived exosomes carrying miR-182-5p improved cardiac function and reduced myocardial infarction, accompanied with reduced inflammation and cell pyroptosis in vivo. Taken together, our findings suggest a cardioprotective effect of exosomal miR-182-5p against myocardial I/R injury, shedding light on an attractive therapeutic strategy.

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.

MicroRNA-182 improves spinal cord injury in mice by modulating apoptosis and the inflammatory response via IKKβ/NF-κB

Spinal cord injury (SCI) is one common neurological condition which involves primary injury and secondary injury. Neuron inflammation and apoptosis after SCI is the most important pathological process of this disease. Here, we tried to explore the influence and mechanism of miRNAs on the neuron inflammatory response and apoptosis after SCI. First, by re-analysis of Gene Expression Omnibus dataset (accession GSE19890), miR-182 was selected for further study because of its suppressive effects on the inflammatory response in the various types of injuries. Functional experiments demonstrated that miR-182 overexpression promoted functional recovery, reduced histopathological changes, and alleviated spinal cord edema in mice. It was also observed that miR-182 overexpression reduced apoptosis and attenuated the inflammatory response in spinal cord tissue, as evidenced by the reduction of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β, and the induction of IL-10. Using a lipopolysaccharide (LPS)-induced SCI model in BV-2 cells, we found that miR-182 was downregulated in the BV-2 cells following LPS stimulation, and upregulation of miR-182 improved LPS-induced cell damage, as reflected by the inhibition of apoptosis and the inflammatory response. IκB kinase β (IKKβ), an upstream target of the NF-κB pathway, was directly targeted by miR-182 and miR-182 suppressed its translation. Further experiments revealed that overexpression of IKKβ reversed the anti-apoptosis and anti-inflammatory effects of miR-182 in LPS stimulated BV-2 cells. Finally, we found that miR-182 overexpression blocked the activation of the NF-κB signaling pathway in vitro and in vivo, as demonstrated by the downregulation of phosphorylated (p‑) IκB-α and nuclear p-p65. Taken together, these data indicate that miR-182 improved SCI-induced secondary injury through inhibiting apoptosis and the inflammatory response by blocking the IKKβ/NF-κB pathway. Our findings suggest that upregulation of miR-182 may be a novel therapeutic target for SCI.

Propofol Downregulates lncRNA MALAT1 to Alleviate Cerebral Ischemia-Reperfusion Injury

Propofol (PPF) is reported to play a protective role in ischemia/reperfusion (I/R) injury, including cerebral ischemia-reperfusion injury (CIRI). This study aims to investigate the mechanism by which PPF ameliorates CIRI. Kunming mice were used to establish the middle cerebral artery occlusion (MCAO)/reperfusion mouse model in vivo. PPF pre-treatment was performed before CIRI. Lactate dehydrogenase (LDH) and creatine phosphokinase (CPK) levels were detected to evaluate the tissue injury. PC12 cells were exposed to hypoxia/reoxygenation (H/R) to construct the in vitro CIRI model, and PC12 cells were pre-treated with PPF before H/R. Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to detect the expression of lncRNA MALAT1 and miR-182-5p. Flow cytometry was used to detect the apoptosis of PC12 cells. Bioinformatics analysis, qRT-PCR, dual-luciferase reporter gene experiments, and RNA immunoprecipitation (RIP) experiments were performed to predict and validate the targeting relationship between MALAT1 and miR-182-5p. Western blot was used to detect Toll-like receptor 4 (TLR4) expression at protein level. PPF pre-treatment remarkably inhibited LDH and CPK levels in the serum of the mice with CIRI, and reduced the apoptosis of PC12 cells exposed to H/R. Besides, PPF pre-treatment markedly suppressed MALAT1 expression in both in vivo and in vitro models and upregulated miR-182-5p expression. MiR-182-5p was validated to be a downstream target gene of MALAT1, and MALAT1 could increase the expression of TLR4 by suppressing miR-182-5p. The effects of PPF on the injury of the mice brain and PC12 cells were partly counteracted by the restoration of MALAT1. PPF protects the brain against I/R-induced injury by regulating MALAT1/miR-182-5p/TLR4 axis.

EGR3-HDAC6-IL-27 Axis Mediates Allergic Inflammation and Is Necessary for Tumorigenic Potential of Cancer Cells Enhanced by Allergic Inflammation-Promoted Cellular Interactions

The objective of this study was to investigate mechanisms of allergic inflammation both in vitro and in vivo in details. For this, RNA sequencing was performed. Early growth response 3 gene (Egr3) was one of the most highly upregulated genes in rat basophilic leukemia (RBL2H3) cells stimulated by antigen. The role of Egr3 in allergic inflammation has not been studied extensively. Egr3 was necessary for passive cutaneous anaphylaxis (PCA) and passive systemic anaphylaxis (PSA). Egr3 promoter sequences contained potential binding site for NF-κB p65. NF-κB p65 directly regulated Egr3 expression and mediated allergic inflammation in vitro. Histone deacetylases (HDACs) is known to be involved in allergic airway inflammation. HDAC6 promoter sequences contained potential binding site for EGR3. EGR3 showed binding to promoter sequences of HDAC6. EGR3 was necessary for increased expression of histone deacetylase 6 (HDAC6) in antigen-stimulated RBL2H3 cells. HDAC6 mediated allergic inflammation in vitro and PSA. TargetScan analysis predicted that miR-182-5p was a negative regulator of EGR3. Luciferase activity assay confirmed that miR-182-5p was a direct regulator of EGR3. MiR-182-5p mimic inhibited allergic inflammation both in vitro and in vivo. Cytokine array showed that HDAC6 was necessary for increased interleukin-27 (IL-27) expression in BALB/C mouse model of PSA. Antigen stimulation did not affect expression of EBI3, another subunit of IL-27 in RBL2H3 cells or BALB/C mouse model of PCA or PSA. IL-27 receptor alpha was shown to be able to bind to HDAC6. IL-27 p28 mediated allergic inflammation in vitro, PCA, and PSA. Mouse recombinant IL-27 protein promoted features of allergic inflammation in an antigen-independent manner. HDAC6 was necessary for tumorigenic and metastatic potential enhanced by PSA. PSA enhanced the metastatic potential of mouse melanoma B16F1 cells in an IL-27-dependent manner. Experiments employing culture medium and mouse recombinant IL-27 protein showed that IL-27 mediated and promoted cellular interactions involving B16F1 cells, lung macrophages, and mast cells during allergic inflammation. IL-27 was present in exosomes of antigen-stimulated RBL2H3 cells. Exosomes from antigen-stimulated RBL2H3 cells enhanced invasion of B16F1 melanoma cells in an IL-27-dependemt manner. These results present evidence that EGR3-HDAC6-IL-27 axis can regulate allergic inflammation by mediating cellular interactions.

HAGLR aggravates neuropathic pain and promotes inflammatory response and apoptosis of lipopolysaccharide-treated SH-SY5Y cells by sequestering miR-182-5p from ATAT1 and activating NLRP3 inflammasome

BACKGROUND

Chronic neuropathic pain is characterized by neuroinflammation. Previously, long noncoding RNA (lncRNA) HAGLR was reported to regulate the inflammatory response of SH-SY5Y cells. However, neither the specific function nor the potential mechanism of HAGLR in neuropathic pain has been explored.

AIM OF THE STUDY

Our study is aimed to figure out the role of HAGLR in neuropathic pain.

METHODS

SH-SY5Y cells were treated with lipopolysaccharide (LPS) to mimic neuron injury in vitro. The chronic constriction injury (CCI) rat models were established by ligation of sciatic nerve to mimic neuropathic pain in vivo. Behavioral assessment assays were performed to determine the effects of HAGLR on hypersensitivity in neuropathic pain. Enzyme-linked immunosorbent assay kits were used for detection of inflammatory cytokines. Flow cytometry analysis and Western blot were applied to detect apoptosis.

RESULTS

HAGLR displayed high levels in spinal cords of CCI rats and in LPS treated SH-SY5Y cells. Knockdown of HAGLR inhibited inflammation and neuron apoptosis of LPS treated SH-SY5Y cells. Mechanistically, HAGLR bound with miR-182-5p in SH-SY5Y cells. ATAT1 served as a target of miR-182-5p. HAGLR activated the NLRP3 inflammasome by ATAT1. Rescue assays demonstrated that overexpression of ATAT1 or NLRP3 reversed the suppressive effects of HAGLR silencing on apoptosis and inflammatory response in SH-SY5Y cells and in spinal cords of CCI rats. The inhibitory effects of silenced HAGLR on hypersensitivity in neuropathic pain were also rescued by ATAT1 or NLRP3.

CONCLUSIONS

HAGLR aggravates neuropathic pain by sequestering miR-182-5p from ATAT1 and activating NLRP3 inflammasome, which may provide a potential therapeutic target for neuropathic pain treatment.

Desflurane protects against liver ischemia/reperfusion injury via regulating miR-135b-5p

BACKGROUND

A number of anesthetics have protective effect against ischemia-reperfusion (I/R) injury, including desflurane. But the function and molecular mechanism of desflurane in liver I/R injury have not been fully understood. The aim of this study was to investigate the effect of desflurane on liver I/R injury and further investigated the molecular mechanisms involving in miR-135b-5p.

METHODS

The models of liver I/R injury in rats were established, and received desflurane treatment throughout the injury. Serum alanine transaminase (ALT) and aspartate transaminase (AST) were measured and compared between groups. H/R-induced cell model in L02 was established, and were treated with desflurane before hypoxia. Quantitative real-time polymerase chain reaction was performed to determine the expression of miR-135b-5p in different groups. The cell apoptosis was detected using flow cytometry assay. Western blot was used for the measurement of protein levels.

RESULTS

I/R significantly increased serum levels of ALT and AST in rats, which were reversed by desflurane treatment. Desflurane also significantly attenuated the increase of cell apoptosis induced by I/R in both vivo and vitro. MiR-135b-5p significantly reversed the protective effect of desflurane against liver I/R injury. Additionally, Janus protein tyrosine kinase (JAK)2 was shown to be a target gene of miR-135b-5p, and miR-135b-5p overexpression significantly decreased the protein levels of p-JAK2, JAK2, p-STAT3.

CONCLUSION

Desflurane attenuated liver I/R injury through regulating miR-135b-5p, and JAK2 was the target gene of mIR-135b-5p. These findings provide references for further development of therapeutic strategies in liver injury.

Caffeic acid phenethyl ester mitigates cadmium-induced hepatotoxicity in mice: Role of miR-182-5p/TLR4 axis

Cadmium (Cd), an environmental pollutant, is evidenced to cause hepatotoxicity. In this study, the potential protective effect of caffeic acid phenethyl ester (CAPE) on cadmium-induced liver damage was investigated. Forty male mice were treated daily with either CdCl₂ (1.5 mg/kg body weight (b.w.), gavage) or CAPE (10 μmol/kg b.w., gavage) or both for 4 weeks. CAPE administration significantly reduced Cd level and liver and body weight, and increased AST, ALT and ALP level. Moreover, CAPE prevented CdCl₂-induced oxidative stress via PI3K/Akt/mTOR pathway and inhibited apoptosis by regulating apoptosis markers. CAPE also suppressed the CdCl₂-induced inflammation by reducing the inflammatory mediators, including TNF-α, IL-6 and IL-1β. Furthermore, CAPE alleviated CdCl₂-induced reduction of TLR4. It should be noted that this effect was achieved by targeting miR-182-5p, and CAPE improved miR-182-5p level. The improvement of the liver tissue histopathology by CAPE confirmed the biochemical data. These results show for the first time that miR-182-5p/TLR4 axis involved in CAPE's protection against CdCl₂-induced hepatotoxicity, and may provide novel insights into the treatment of cadmium-related diseases.

SIRT1 alleviates hepatic ischemia-reperfusion injury via the miR-182-mediated XBP1/NLRP3 pathway

The hepatoprotection of histone deacetylase sirtuin 1 (SIRT1) has been identified to attenuate ischemia-reperfusion (IR)-triggered inflammation and liver damage. This study was performed to characterize the function of SIRT1 in hepatic IR injury. In in vivo assays on liver-specific knockout mice of SIRT1, we first validated the effect of SIRT1 knockout on liver damage and XBP1/NLRP3 inflammasome activation. Next, we examined whether knockdown of XBP1/NLRP3 or miR-182 agomir could reverse the effect of SIRT1 knockout. In in vitro assays, NCTC1469 cells subjected to hypoxia/reoxygenation (H/R) were transduced with small interfering RNA (siRNA)/activator of SIRT1 or miR-182 agomir to confirm the effect of SIRT1 on NCTC1469 cell behaviors as well as the regulation of miR-182 and the XBP1/NLRP3 signaling pathway. Hepatic IR injury was appreciably aggravated in SIRT1 knockout mice, and SIRT1 knockdown abolished the inhibition of XBP1/NLRP3 inflammasome activation, which was reversed by NLRP3 knockdown, XBP1 knockdown, or miR-182 agomir. Mechanistically, miR-182 expression was positively regulated by SIRT1 in hepatic IR injury in mice, and miR-182 inhibited the expression of XBP1 by binding to the 3' untranslated region (UTR) of XBP1. The histone deacetylase SIRT1 inhibits the downstream XBP1/NLRP3 inflammatory pathway by activating miR-182, thus alleviating hepatic IR injury in mice.

microRNAs in liver and kidney ischemia reperfusion injury: insight to improve transplantation outcome

Ischemia reperfusion injury (IRI) is a condition that occurs wherever blood flow and oxygen is reduced or absent, such as trauma, vascular disease, stroke, and solid organ transplantation. This condition can lead to tissue damage, especially during organ transplantation. Under such circumstances, some signaling pathways are activated, leading to up- or down- regulation of several genes such as microRNAs (miRNAs) that might attenuate or ameliorate this status. Therefore, by manipulating miRNAs level, they can be used as a biomarker for early diagnosis of IRI or suggestive to be therapeutic agents in clinical situation in future.

The miR-183/96/182 Cluster Regulates the Functions of Corneal Resident Macrophages

Tissue-resident macrophages (ResMϕ) play important roles in the normal development and physiological functions as well as tissue repair and immune/inflammatory response to both internal and external insults. In cornea, ResMϕ are critical to the homeostasis and maintenance, wound healing, ocular immune privilege, and immune/inflammatory response to injury and microbial infection. However, the roles of microRNAs in corneal ResMϕ are utterly unknown. Previously, we demonstrated that the conserved miR-183/96/182 cluster (miR-183/96/182) plays important roles in sensory neurons and subgroups of both innate and adaptive immune cells and modulates corneal response to bacterial infection. In this study, we provide direct evidence that the mouse corneal ResMϕ constitutively produce both IL-17f and IL-10. This function is regulated by miR-183/96/182 through targeting Runx1 and Maf, key transcriptional regulators for IL-17f and IL-10 expression, respectively. In addition, we show that miR-183/96/182 has a negative feedback regulation on the TLR4 pathway in mouse corneal ResMϕ. Furthermore, miR-183/96/182 regulates the number of corneal ResMϕ. Inactivation of miR-183/96/182 in mouse results in more steady-state corneal resident immune cells, including ResMϕ, and leads to a simultaneous early upregulation of innate IL-17f and IL-10 production in the cornea after Pseudomonas aeruginosa infection. Its multiplex regulations on the simultaneous production of IL-17f and IL-10, TLR4 signaling pathway and the number of corneal ResMϕ place miR-183/96/182 in the center of corneal innate immunity, which is key to the homeostasis of the cornea, ocular immune privilege, and the corneal response to microbial infections.

Construction of a circRNA-miRNA-mRNA Network Related to Macrophage Infiltration in Hepatocellular Carcinoma

Immune cells in the tumor microenvironment play a crucial role in regulating tumor progression. The circular RNA (circRNA) regulatory network involved in immune cell infiltration in hepatocellular carcinoma (HCC) remains largely unknown. In this study, the “estimate the proportion of immune and cancer cells” (EPIC) application is used to evaluate the fractions of immune cells, cancer-associated fibroblasts, and endothelial cells in HCC from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Patients with a high macrophage fraction have better overall survival, and macrophage fraction is an independent prognostic factor for HCC. Next, the common differentially expressed mRNAs (DEmRNAs), miRNAs (DEmiRNAs), and circRNAs (DEcircRNAs) between paired tumor and non-tumor tissues are screened out from the TCGA and/or GEO databases. Through spearman correlation analysis, the macrophage-related DEmRNAs are identified to construct a circRNA-miRNA-mRNA regulatory network, which includes 6 DEcircRNAs, 7 DEmiRNAs, and 45 DEmRNAs. Functional enrichment analysis reveals that these DEmRNAs are mainly involved in immune-related processes. Furthermore, six hub DEmRNAs are identified to establish a hub circRNA regulatory network. Among the DEmRNAs in the network, PRC1 is identified as the most influential node. PRC1 high expression is correlated with poor prognosis and low macrophage infiltration in HCC. Taken together, we identify a certain circRNA regulatory network related to macrophage infiltration and provide novel insight into the mechanism of study and therapeutic targets for HCC.

Circ_002664/miR-182-5p/Herpud1 pathway importantly contributes to OGD/R-induced neuronal cell apoptosis

OBJECTIVE

Apoptosis is a prominent form of neuron death in cerebral ischemia-reperfusion-induced injury. Accompanied with the pathogenesis, Circ_002664 is upregulated. However, its role in the neuron apoptosis and the underlying mechanisms are unknown.

METHODS

In this study, HT22 cells were treated with oxygen glucose deprivation and reoxygenation (OGD/R). The cell viability, apoptosis, proliferation and mitochondrial potential were examined. The expressions of interested genes, Circ_002664, miR-182-5p and Herpud1, were measured. The roles of these genes in OGD/R-induced cell injury were investigated by knockdown, overexpression alone or in combination. Additionally, the interactions between Circ_002664, miR-182-5p and Herpud1 were validated by luciferase report assay. The levels of MAP2, CHOP, Cytochrome C (CYC) and cleaved caspase-3 were determined.

RESULTS

OGD/R treatment significantly increased cell apoptosis, decreased cell proliferation and mitochondrial potential, as well as increased Circ_002664 and Herpud1 expressions, and decreased miR-182-5p level. Circ_002664 knockdown markedly inhibited the effects by OGD/R on cell survival and altered expression of miR-182-5p and Herpud1. MiR-182-5p was observed sponged by Circ_002664 and negatively mediated its effect above mentioned, and this was by directly targeting Herpud1. Additionally, it was observed that CHOP expressions were regulated by Circ_002664/miR-182-5p/Herpud1 pathway, and in turn mediated its regulation in CYC and cleaved caspase-3.

CONCLUSIONS

In summary, our data showed that the Circ_002664 importantly contributed to neuronal cell apoptosis induced by OGD/R treatment, and this might be achieved by directly targeting miR-182-5p/Herpud1 pathway.

MicroRNA-142-3p attenuates hepatic ischemia/reperfusion injury via targeting of myristoylated alanine-rich C-kinase substrate

MiR-142-3p as one key molecule in oncogenesis and inflammation plays crucial roles in hepatic fibrosis, hepatocellular carcinoma and other liver disease. However, there have no literatures to report its effects on hepatic ischemia-reperfusion (HI/R) injury. In the present work, hypoxia reoxygenation (H/R) models on AML12 and HepG2 cells, and ischemia/reperfusion model in mice were established. The methods of real-time PCR, dual luciferase reporter, mimic, inhibitor, agomir, antagomir and siRNA transfection assays were used. The expression levels of miR-142-3p were decreased in model groups in vitro and in vivo compared with control group or Sham group, which directly targeted MARCKS to regulate its expression. Then, MARCKS activated p38/JNK signal, up-regulated NF-κB expression to accelerate inflammation, and inhibited PI3K/AKT signal to promote apoptosis. Moreover, miR-142-3p mimic in vitro and agomir in vivo lowered the expression levels of MARCKS, thereby alleviating apoptosis and inflammation to relieve HI/R injury. Furthermore, miR-142- 3p inhibitor in vitro and antagomir in vivo up-regulated the expression levels of MARCKS to aggravate HI/R damage via promoting inflammation and apoptosis. Consistently, MARCKS siRNA markedly inhibited HI/R injury by restraining apoptosis and inflamm- ation in mice. MiR-142-3p played a considerable part in adjusting HI/R injury by targeting MARCKS, and miR-142-3p/MARCKS should be a new therapeutic target for HI/R injury.

MicroRNA-146a Protects Against Ischemia/Reperfusion Liver Injury Through Inhibition of Toll-like Receptor 4 Signaling Pathway in Rats

Hepatic ischemia/reperfusion injury (IRI) is a severe and common clinical challenge involved in liver surgery and transplantation. MicroRNA-146a (miR-146a) has recently been reported to be abnormally expressed in hepatic IRI, but the underlying mechanism is not fully elucidated. Accumulating evidences showed miR-146a targets Toll-like receptor 4 (TLR4) signaling pathway. Here, we found that miR-146a inhibited TLR4 signaling pathway accompanied by attenuated liver dysfunction, histologic injury and inflammation. Conversely, miR-146a inhibition increased TLR4 and interleukin-1 receptor-associated kinase, accompanied by exacerbated hepatic IRI and inflammation. Taken together, these data indicated that miR-146a protect against hepatic IRI via inhibiting TLR4 signaling pathway. In addition, we verified ultrasound microbubble-mediated gene transfection improved miR-146a transfection efficacy.

Identification of Key Transcription Factors AP-1 and AP-1-Dependent miRNAs Forming a Co-Regulatory Network Controlling PTEN in Liver Ischemia/Reperfusion Injury

Liver ischemia/reperfusion (I/R) injury is a complex and common clinical disease with limited therapeutic options. The aim of our study was to discover the candidate target genes in liver I/R injury and to further elucidate the potential regulatory mechanisms, especially the ones involving transcription factors and miRNAs. The analysis of mouse data set GSE10657 from Gene Expression Omnibus database (GEO) revealed 203 differentially expressed genes (DEGs) including 19 transcription factors (TFs). Functional and pathway enrichment analyses were conducted to explore their biological functions. We further obtained the targets of TFs and miRNAs, to form our TF-mRNA/TF-miRNA-mRNA co-regulatory network. In our network, we found that the important subunits of activator protein 1 (AP-1) including JUN, FOS and ATF3, were hub genes in liver I/R injury. AP-1 target genes were activated in our mouse models. AP-1 could transcriptionally activate phosphatase and tensin homolog (PTEN) while AP-1-dependent miRNAs countered this effect. In conclusion, this study suggested that AP-1, together with AP-1-dependent miRNAs formed a co-regulatory network enabling AP-1 target genes to be tightly controlled, which will complete the mechanism of liver ischemia/reperfusion injury and provide direction for finding potential therapeutic targets.

The protective effects of salvianolic acid A against hepatic ischemia-reperfusion injury via inhibiting expression of toll-like receptor 4 in rats

INTRODUCTION

Ischemia-reperfusion injury (IRI) is a serious complication of hepatectomy and liver transplantation. The aim of this study was to evaluate the protective effects of salvianolic acid-A (Sal-A) against IRI-induced hepatocellular injury.

MATERIAL AND METHODS

Forty rats were randomly divided into the following four groups: (1) sham group, (2) IR group, (3) Sal-A(10) group and (4) Sal-A(20) group. After 90 min of ischemia and 6 h of reperfusion, serum alanine aminotransferease (ALT) and apartate aminotransferase (AST) levels were measured; the amounts of malondialdehyde (MDA) and superoxide dismutase (SOD) in the liver tissue were determined; the expression of Bcl-2 and caspase-3 was detected and the severity of apoptosis, inflammation and pathological alterations were evaluated. Also apoptosis and mRNA and protein levels of TLR4 (toll-like receptor 4) were tested.

RESULTS

The serum aminotransferases, hepatic MDA concentration, and apoptotic cells in the IR group were significantly higher than in the sham group (p < 0.01), whereas the Sal-A group values were lower than in the IR group (p < 0.05). Compared with the IR group, the Sal-A groups had significantly higher Bcl-2 expression and downregulated cleaved caspase-3 expression in liver tissue. Moreover, increased mRNA and protein levels of TLR4 in IR rats and Sal-A could improve the increased mRNA and protein levels of TLR4.

CONCLUSIONS

Sal-A had a synergistically protective effect on the liver tissue against IRI that might be due to decreased oxidative stress, inflammation, hepatocellular apoptosis and include, at least in part, the regulation of TLR4.

Suppression of microRNA‑27a protects against liver ischemia/reperfusion injury by targeting PPARγ and inhibiting endoplasmic reticulum stress

Liver ischemia‑reperfusion (I/R) injury is an important clinical issue related to liver transplantation. Recent studies suggest that microRNAs are implicated in various biological and pathological processes, including liver I/R injury. This study aimed to investigate the role and potential mechanism of miR‑27a during liver I/R injury. A liver I/R model was induced via 60 min of ischemia and reperfusion for 6 h in rats. Cells were transfected with miR‑27a mimics or the miR‑27a inhibitor to examine the effect of miR‑27a on liver I/R. Apoptotic cells were detected by flow cytometry and TUNEL staining. The expression of miR‑27a was measured by real‑time PCR. The expression of peroxisome proliferator‑activated receptor γ (PPARγ); gastrin‑releasing peptide 78 (GRP78) and C/EBP homologous protein (CHOP) were detected by western blot analysis. The results showed that miR‑27a was significantly upregulated during I/R injury in vivo and in vitro. In addition, miR‑27a inhibitors attenuated hypoxia/reoxygenation (H/R)‑induced oxidative stress, endoplasmic reticulum stress (ERS) and apoptosis in AML12 cells. By contrast, miR‑27a mimics promoted hypoxia/reoxygenation‑induced ERS, and apoptosis. Furthermore, PPARγ was identified as a target gene of miR‑27a using bioinformatic analysis and a dual‑luciferase reporter assay. Knockdown of PPARγ significantly abrogated the inhibitory effect of miR‑27a inhibitors on the ERS pathway. Moreover, the miR‑27a antagomir attenuated liver I/R injury in rats, a finding manifested by reduced ALT/AST, hepatocyte apoptosis, oxidative stress and inhibition of the ERS pathway. Taken together, these findings demonstrate that suppression of miR‑27a protects against liver I/R injury by targeting PPARγ and by inhibiting the ERS pathway.

MicroRNA-106a Provides Negative Feedback Regulation in Lipopolysaccharide-Induced Inflammation by targeting TLR4

Acute lung injury (ALI) is a common clinical disease with high incidence and mortality rate, which is characterized by severe inflammatory response and tissues damage. MicroRNAs (miRNAs) have been regarded as novel regulators of inflammation, and play an important role in various inflammatory diseases. However, it remains unknown whether the regulatory mechanisms mediated by miR-106a is involved in LPS-induced ALI. In this study, we found that expression of miR-106a was significantly decreased in lung tissues of ALI mice and LPS-stimulated macrophages. We also revealed that over-expression of miR-106a significantly decreased the production of pro-inflammatory cytokines, including IL-1β, IL-6 and TNF-α, whereas this effect was reversed by the inhibition of miR-106a. Moreover, miR-106a inhibits NF-κB activation by targeting TLR4 expression. We further demonstrated that miR-106a inhibited TLR4 expression via binding directly to the 3'-UTR of TLR4. Taken together, the results of the present study illuminated that miR-106a is a negative feedback regulator in LPS-stimulated inflammation through TLR4/NF-κB signaling pathway.

miR-219a-5p Ameliorates Hepatic Ischemia/Reperfusion Injury via Impairing TP53BP2

BACKGROUND

Hepatic ischemia/reperfusion (I/R) injury is a serious complication that occurs upon hypovolemic shock, liver resection, and transplantation. A significant age-dependent difference in the injury response to hepatic I/R in both human and animal models has been reported. Nevertheless, the molecular mechanism is currently unclear.

AIMS

To clarify the reason why aged animals or people were more vulnerable to hepatic I/R injury.

METHODS

In the present study, we found decreased miR-219a-5p expression in the old mice more vulnerable to hepatic I/R injury. Administrated with agomir-miR-219a-5p diminished the severity of hepatic I/R injury in old mice, as indicated by lower serum ALT and AST, oxidative parameters including MDA, TOA, and OSI, and decreased apoptotic cell number. The effect of miR-219a-5p was also confirmed in the H₂O₂-induced apoptosis model in AML-12 and NCTC1469 cells. After miR-219a-5p overexpression, two key apoptosis-related proteins Bax and P21, target genes of TP53, were decreased. Furthermore, TP53BP2 interacts with p53 family members and promotes their transcriptional activities toward pro-apoptosis genes.

RESULTS

RNA sequencing, western blot, and luciferase reporter assay proved that TP53BP2, a crucial TP53 transcriptional activity enhancer in vivo, was directly regulated by miR-219a-5p.

CONCLUSIONS

In summary, our study demonstrated that age-related miR-219a-5p can attenuate hepatic I/R injury through inhibiting TP53BP2 and downstream TP53-dependent apoptosis of hepatic cells in mice.

Sevoflurane exerts protective effects on liver ischemia/reperfusion injury by regulating NFKB3 expression via miR-9-5p

Hepatic ischemia/reperfusion (IR) injury is a critical contraindication of hepatobiliary surgery and results in severe liver damage. It is imperative to identify underlying pathophysiological mechanisms. In the current study, a rat model of liver IR was established to explore the mechanisms of sevoflurane during surgical intervention on IR. The detection of cytokines was performed using ELISA and reverse transcription-quantitative polymerase chain reaction and western blot assays were used to detect mRNA and protein expression levels, respectively. The target protein of microRNA (miR)-9-5p was identified by in vitro luciferase reporter assay. Cell apoptosis was detected by Annexin-V/propidium iodide and TUNEL staining assays. The results demonstrated that sevoflurane exerted protective effect against liver IR. Sevoflurane administration ameliorated a cytokine storm by decreasing serum levels of interleukin (IL)-1 and −6 and tumor necrosis factor (TNF)-α, and improved liver function was determined. IR-induced damage was mediated by an increase in transcription factor p65 expression and activation of the nuclear factor (NF)-κB signaling pathway, which were suppressed by sevoflurane treatment. In situ analysis predicted that NFKB3, encoding for p65, may be targeted by miR-9-5p and the hypothesis was verified by in vitro reporter assays using wild type and mutant sequences of the NFKB3 3′-untranslated region. Furthermore, pretreatment of hepatic tissue with a miR-9-5p mimic inhibited IR-associated injury as suggested by the decrease in the Suzuki score and decreased serum levels of TNF-α, IL-1 and IL-6. The results indicated that sevoflurane protected the liver from IR injury by increasing miR-9-5p expression and miR-9-5p may be a potential treatment target in IR.

miR-182-5p Attenuates High-Fat -Diet-Induced Nonalcoholic Steatohepatitis in Mice

INTRODUCTION AND AIM

Patients with NASH have increased risk for sepsis or cardiovascular disease after Liver transplantation. An important role of Toll-like receptor (TLR) 4 in the pathogenesis of nonalcoholic steatohepatitis (NASH) was demonstrated. Here, we study the role of miR-182-5p in TLR4 expression and high-fat-diet (HFD)-induced NASH in vitro and in vivo Material and methods. Following transfection with a miR-182-5p mimic, the effect of miR-182-5p on TLR4 in RAW264.7 and HepG2 cells was investigated. Following administration of the miR-182-5p mimic into the livers of HFD-induced NASH mice, we determined the in vivo expression of TLR4, TNFa, and IL-6 and assessed the histologic features of the livers. Results Following lipopolysaccharide (LPS) treatment of RAW264.7 cells, real-time RT-PCR and western blot results indicated decreases levels of TLR4 mRNA and protein in the miR-182-5p group as compared with levels observed in controls, with similar trends were observed in TNFa and IL-6 protein levels. Following oleic acid (OA) treatment of HepG2 cells, TLR4, TNFa, and IL-6 levels were significantly decreased in the miR-182-5p group as compared with levels observed in controls. Following miR-182-5p administration, TLR4 mRNA and protein levels decreased along with those of TNFa and IL-6 proteins, and the liver weight/body weight ratio of treated mice was less than that observed in controls. Furthermore, hematoxylin and eosin staining showed that the miR-182-5p-treated group exhibited low adiposecell cross-sectional areas, and Oil Red O staining showed decreases in the size of lipid droplets in the miR-182-5p-treated group.

CONCLUSIONS

miR-182-5p ameliorated HFD-induced NASH by suppressing TLR4.

MicroRNA‑93 inhibits chondrocyte apoptosis and inflammation in osteoarthritis by targeting the TLR4/NF‑κB signaling pathway

Osteoarthritis (OA) is a serious disease of the articular cartilage, and inflammation has been implicated in its pathogenesis. Previously, microRNAs (miRNAs) have been proposed as novel regulators of inflammation, however, the functional role of microRNAs in regulating inflammation in OA remains to be fully elucidated. The aim of the present study was to investigate the roles of miRNAs in OA inflammation and the underlying molecular mechanism. Firstly, the miRNA expression patterns were analyzed in the articular cartilage tissues from experimental OA mice using an miRNA microarray. miRNA (miR)-93 was identified with particular interest due to its reported effects on apoptosis and inflammation suppression. Subsequently, the expression of miR-93 was further validated in the articular cartilage tissues of OA mice and lipopolysaccharide (LPS)-stimulated primary chondrocytes. Using this LPS-induced chondrocyte injury model, the overexpression of miR-93 enhanced cell viability, improved cell apoptosis and attenuated the inflammatory response, as reflected by reductions in pro-inflammatory cytokines, including tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6. In addition, Toll-like receptor 4 (TLR4), an important regulator of the nuclear factor-κB (NF-κB) signaling pathway, was identified as a direct target of miR-93 in chondrocytes. Furthermore, the restoration of TLR4 markedly abrogated the inhibitory effects of miR-93 on the chondrocyte apoptosis and inflammation induced by LPS. In addition, the overexpression of miR-93 by agomir-miR-93 significantly inhibited the levels of pro-inflammatory cytokines and cell apoptosis, whereas antagomir-93 exacerbated apoptosis and inflammation in vivo. Taken together, the results of the study suggested that miR-93 may be a promising therapeutic target for the treatment of human OA.

MicroRNA-182-5p contributes to the protective effects of thrombospondin 1 against lipotoxicity in INS-1 cells

The dysfunction of beta cells serves an important role in the pathogenesis of type 2 diabetes mellitus (T2DM). An improved understanding of the molecular mechanisms underlying beta cell mass and failure will be useful for identifying novel approaches toward preventing and treating this disease. Recent studies have indicated that free fatty acids (FFAs) can cause beta cell dysfunction. In the present study, palmitate (Pal) was used as a FFA and its functions on cell viability and apoptosis were detected. MTT assay and flow cytometry were used and the results revealed that incubation of INS-1 cells with Pal significantly decreased cell viability and increased cell apoptosis. However, a co-incubation with thrombospondin 1 (THBS-1) protected the cells against Pal-induced toxicity. Numerous studies have demonstrated that microRNAs (miRs) are involved in fatty acid-induced beta cell dysfunction. Various studies have reported that miR-182-5p is associated with a number of diseases, including cancer, heart disease, and leukemia. However, to the best of our knowledge miR-182-5p has never been reported to be associated with diabetes. In the present study, miR-182-5p, which is predicted to target the 3'-untranslated region (UTR) of THBS-1, was detected using reverse transcription-quantitative polymerase chain reaction in INS-1 cells in response to Pal. miR-182-5p was significantly increased in Pal-treated cells compared with the control cells. Furthermore, miR-182-5p mimics significantly decreased cell viability and increased Pal-induced apoptosis in INS-1 cells. However, cell viability was increased and Pal-induced apoptosis was decreased in cells that were treated with miR-182-5p inhibitors. The present findings also revealed that overexpression of THBS-1 counteracted the effect of miR-182-5p on cell viability and apoptosis. These results suggested that miR-182-5p is involved in the mechanism of THBS 1 on the modulation of beta cell survival.

Immune Regulation of Tissue Repair and Regeneration via miRNAs-New Therapeutic Target

The importance of immunity in tissue repair and regeneration is now evident. Thus, promoting tissue healing through immune modulation is a growing and promising field. Targeting microRNAs (miRNAs) is an appealing option since they regulate immunity through post-transcriptional gene fine-tuning in immune cells. Indeed, miRNAs are involved in inflammation as well as in its resolution by controlling immune cell phenotypes and functions. In this review, we first discuss the immunoregulatory role of miRNAs during the restoration of tissue homeostasis after injury, focusing mainly on neutrophils, macrophages and T lymphocytes. As tissue examples, we present the immunoregulatory function of miRNAs during the repair and regeneration of the heart, skeletal muscles, skin and liver. Secondly, we discuss recent technological advances for designing therapeutic strategies which target miRNAs. Specifically, we highlight the possible use of miRNAs and anti-miRNAs for promoting tissue regeneration via modulation of the immune system.

Inter-Individual Variability in Acute Toxicity of R-Pulegone and R-Menthofuran in Human Liver Slices and Their Influence on miRNA Expression Changes in Comparison to Acetaminophen

Monoterpenes R-pulegone (PUL) and R-menthofuran (MF), abundant in the Lamiaceae family, are frequently used in herb and food products. Although their hepatotoxicity was shown in rodent species, information about their effects in human liver has been limited. The aim of our study was to test the effects of PUL, MF and acetaminophen (APAP, as a reference compound) on cell viability and microRNA (miRNA) expression in human precision-cut liver slices. Slices from five patients were used to follow up on the inter-individual variability. PUL was toxic in all liver samples (the half-maximal effective concentration was 4.0 µg/mg of tissue), while MF and surprisingly APAP only in two and three liver samples, respectively. PUL also changed miRNA expression more significantly than MF and APAP. The most pronounced effect was a marked decrease of miR-155-5p expression caused by PUL even in non-toxic concentrations in all five liver samples. Our results showed that PUL is much more toxic than MF and APAP in human liver and that miR-155-5p could be a good marker of PUL early hepatotoxicity. Marked inter-individual variabilities in all our results demonstrate the high probability of significant differences in the hepatotoxicity of tested compounds among people.

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.

Protection of macrophages from intracellular pathogens by miR-182-5p mimic-a gene expression meta-analysis approach

The goals of this study were to (a) define which host genes are of particular importance during the interactions between macrophages and intracellular pathogens, and (b) use this knowledge to gain fresh, experimental understanding of how macrophage activities may be manipulated during host defense. We designed an in silico method for meta-analysis of microarray gene expression data, and used this to combine data from 16 different studies of cells in the monocyte-macrophage lineage infected with seven different pathogens. Three thousand four hundred ninety-eight genes were identified, which we call the macrophage intracellular pathogen response (macIPR) gene set. As expected, the macIPR gene set showed a strong bias toward genes previously associated with the immune response. Predicted target sites for miR-182-5p (miR-182) were strongly over-represented among macIPR genes, indicating an unexpected role for miR-182-regulatable genes during intracellular pathogenesis. We therefore transfected primary human alveolar macrophage-like monocyte-derived macrophages from multiple different donors with synthetic miR-182, and found that miR-182 overexpression (a) increases proinflammatory gene induction during infection with Francisella tularensis live vaccine strain (LVS), (b) primes macrophages for increased autophagy, and (c) enhances macrophage control of both gram negative F. tularensisLVS and gram positive Bacillus anthracisANR-1 spores. These data therefore suggest a new application for miR-182 in promoting resistance to intracellular pathogens.