Hypoxia-induced microRNA-191 contributes to hepatic ischemia/reperfusion injury through the ZONAB/Cyclin D1 axis

Glutamine maintains the stability of alveolar structure and function after lung transplantation by inhibiting autophagy

Excessive autophagy may lead to degradation and damage of alveolar epithelial cells after lung transplantation, eventually leading to alveolar epithelial cell loss, affecting the structural integrity and function of alveoli. Glutamine (Gln), a nutritional supplement, regulates autophagy through multiple signaling pathways. In this study, we explored the protective role of Gln on alveolar epithelial cells by inhibiting autophagy. In vivo, a rat orthotopic lung transplant model was carried out to evaluate the therapeutic effect of glutamine. Ischemia/reperfusion (I/R) induced alveolar collapse, edema, epithelial cell apoptosis, and inflammation, which led to a reduction of alveolar physiological function, such as an increase in peak airway pressure, and a decrease in lung compliance and oxygenation index. In comparison, Gln preserved alveolar structure and function by reducing alveolar apoptosis, inflammation, and edema. In vitro, a hypoxia/reoxygenation (H/R) cell model was performed to simulate IR injury on mouse lung epithelial (MLE) cells and human lung bronchus epithelial (Beas-2B) cells. H/R impaired the proliferation of epithelial cells and triggered cell apoptosis. In contrast, Gln normalized cell proliferation and suppressed I/R-induced cell apoptosis. The activation of mTOR and the downregulation of autophagy-related proteins (LC3, Atg5, Beclin1) were observed in Gln-treated lung tissues and alveolar epithelial cells. Both in vivo and in vitro, rapamycin, a classical mTOR inhibitor, reversed the beneficial effects of Gln on alveolar structure and function. Taken together, Glnpreserved alveolar structure and function after lung transplantation by inhibiting autophagy.

The deubiquitinase OTUD1 stabilizes NRF2 to alleviate hepatic ischemia/reperfusion injury

Hepatic ischemia/reperfusion (I/R) injury is an important cause of liver function impairment following liver surgery. The ubiquitin-proteasome system (UPS) plays a crucial role in protein quality control and has substantial impact on the hepatic I/R process. Although OTU deubiquitinase 1 (OTUD1) is involved in diverse biological processes, its specific functional implications in hepatic I/R are not yet fully understood. This study demonstrates that OTUD1 alleviates oxidative stress, apoptosis, and inflammation induced by hepatic I/R injury. Mechanistically, OTUD1 deubiquitinates and activates nuclear factor erythroid 2-related factor 2 (NRF2) through its catalytic site cysteine 320 residue and ETGE motif, thereby attenuating hepatic I/R injury. Additionally, administration of a short peptide containing the ETGE motif significantly mitigates hepatic I/R injury in mice. Overall, our study elucidates the mechanism and role of OTUD1 in ameliorating hepatic I/R injury, providing a theoretical basis for potential treatment using ETGE-peptide.

DNA-binding protein-A promotes kidney ischemia/reperfusion injury and participates in mitochondrial function

DNA-binding protein-A (DbpA; gene: Ybx3) belongs to the cold shock protein family with known functions in cell cycling, transcription, translation, and tight junction communication. In chronic nephritis, DbpA is upregulated. However, its activities in acute injury models, such as kidney ischemia/reperfusion injury (IRI), are unclear. To study this, mice harboring Ybx3+/+, Ybx3+/- or the Ybx3-/- genotype were characterized over 24 months and following experimental kidney IRI. Mitochondrial function, number and integrity were analyzed by mitochondrial stress tests, MitoTracker staining and electron microscopy. Western Blot, immunohistochemistry and flow cytometry were performed to quantify tubular cell damage and immune cell infiltration. DbpA was found to be dispensable for kidney development and tissue homeostasis under healthy conditions. Furthermore, endogenous DbpA protein localizes within mitochondria in primary tubular epithelial cells. Genetic deletion of Ybx3 elevates the mitochondrial membrane potential, lipid uptake and metabolism, oxygen consumption rates and glycolytic activities of tubular epithelial cells. Ybx3-/- mice demonstrated protection from IRI with less immune cell infiltration, endoplasmic reticulum stress and tubular cell damage. A presumed protective mechanism was identified via upregulated antioxidant activities and reduced ferroptosis, when Ybx3 was deleted. Thus, our studies reveal DbpA acts as a mitochondrial protein with profound adverse effects on cell metabolism and highlights a protective effect against IRI when Ybx3 is genetically deleted. Hence, preemptive DbpA targeting in situations with expected IRI, such as kidney transplantation or cardiac surgery, may preserve post-procedure kidney function.

DNA-binding protein-A: a multitool in tubular epithelial cells

Acute kidney injury is still associated with high morbidity and mortality. Reichardt et al. investigated DNA-binding protein-A (Ybx3) in acute kidney injury induced by ischemia-reperfusion injury and found that mice lacking Ybx3 have altered mitochondrial function and increased antioxidant activity, making them more resistant to ischemia-reperfusion injury-acute kidney injury. The study highlights a new role of the multifaceted protein DNA-binding protein-A, which could be potentially therapeutically exploited.

TGF-β1-triggered BMI1 and SMAD2 cooperatively regulate miR-191 to modulate bone formation

Transforming growth factor β 1 (TGF-β1), as the most abundant signaling molecule in bone matrix, is essential for bone homeostasis. However, the signaling transduction of TGF-β1 in the bone-forming microenvironment remains unknown. Here, we showed that microRNA-191 (miR-191) was downregulated during osteogenesis and further decreased by osteo-favoring TGF-β1 in bone marrow mesenchymal stem cells (BMSCs). MiR-191 was lower in bone tissues from children than in those from middle-aged individuals and it was negatively correlated with collagen type I alpha 1 chain (COL1A1). MiR-191 depletion significantly increased osteogenesis and bone formation in vivo. Hydrogels embedded with miR-191-low BMSCs displayed a powerful bone repair effect. Mechanistically, transcription factors BMI1 and SMAD2 coordinately controlled miR-191 level. In detail, BMI1 and pSMAD2 were both upregulated by TGF-β1 under osteogenic condition. SMAD2 activated miR-191 transcription, while BMI1 competed with SMAD2 for binding to miR-191 promoter region, thus disturbing the activation of SMAD2 on miR-191 and reducing miR-191 level. Altogether, our findings reveal that miR-191 regulated by TGF-β1-induced BMI1 and SMAD2 negatively modulated bone formation and regeneration, and inhibition of miR-191 might be therapeutically useful to enhance bone repair in clinic.

MiRNAs in Alcohol-Related Liver Diseases and Hepatocellular Carcinoma: A Step toward New Therapeutic Approaches?

Alcohol-related Liver Disease (ALD) is the primary cause of chronic liver disorders and hepatocellular carcinoma (HCC) development in developed countries and thus represents a major public health concern. Unfortunately, few therapeutic options are available for ALD and HCC, except liver transplantation or tumor resection for HCC. Deciphering the molecular mechanisms underlying the development of these diseases is therefore of major importance to identify early biomarkers and to design efficient therapeutic options. Increasing evidence indicate that epigenetic alterations play a central role in the development of ALD and HCC. Among them, microRNA importantly contribute to the development of this disease by controlling the expression of several genes involved in hepatic metabolism, inflammation, fibrosis, and carcinogenesis at the post-transcriptional level. In this review, we discuss the current knowledge about miRNAs' functions in the different stages of ALD and their role in the progression toward carcinogenesis. We highlight that each stage of ALD is associated with deregulated miRNAs involved in hepatic carcinogenesis, and thus represent HCC-priming miRNAs. By using in silico approaches, we have uncovered new miRNAs potentially involved in HCC. Finally, we discuss the therapeutic potential of targeting miRNAs for the treatment of these diseases.

Regulation of epithelial cell differentiation by the Ubiquitous expressed transcript isoform 1 in ulcerative colitis

BACKGROUND AND AIM

Mucosal healing has emerged as a desirable treatment goal for patients with ulcerative colitis (UC). Healing of mucosal wounds involves epithelial cell proliferation and differentiation, and Y-box transcription factor ZONAB has recently been identified as the key modulator of intestinal epithelial restitution.

METHODS

We studied the characteristics of UXT-V1 expression in UC patients using immunohistochemistry and qPCR. The functional role of UXT-V1 in the colonic epithelium was investigated using lentivirus-mediated shRNA in vitro and ex vivo. Through endogenous Co-immunoprecipitation and LC-MS/MS, we identified ZONAB as a UXT-V1-interactive protein.

RESULTS

Herein, we report that UXT-V1 promotes differentiation of intestinal epithelial cells by regulating the nuclear translocation of ZONAB. UXT-V1 was upregulated in the intestinal epithelia of UC patients compared with that of healthy controls. Knocking down UXT-V1 in NCM-460 cells led to the enrichment of pathways associated with proliferation and differentiation. Furthermore, the absence of UXT-V1 in cultured intestinal epithelial cells and colonic organoids inhibited differentiation to the goblet cell phenotype. Mechanistically, the loss of UXT-V1 in the intestinal epithelial cells allowed nuclear translocation of ZONAB, wherein it regulated the transcription of differentiation-related genes, including AML1 and KLF4.

CONCLUSION

Taken together, our study reveals a potential role of UXT-V1 in regulating epithelial cell differentiation, proving a molecular basis for mucosal healing in UC.

Silencing circSERPINE2 restrains mesenchymal stem cell senescence via the YBX3/PCNA/p21 axis

Increasing evidence indicates that circular RNAs (circRNAs) accumulate in aging tissues and nonproliferating cells due to their high stability. However, whether upregulation of circRNA expression mediates stem cell senescence and whether circRNAs can be targeted to alleviate aging-related disorders remain unclear. Here, RNA sequencing analysis of differentially expressed circRNAs in long-term-cultured mesenchymal stem cells (MSCs) revealed that circSERPINE2 expression was significantly increased in late passages. CircSERPINE2 small interfering RNA delayed MSC senescence and rejuvenated MSCs, while circSERPINE2 overexpression had the opposite effect. RNA pulldown followed by mass spectrometry revealed an interaction between circSERPINE2 and YBX3. CircSERPINE2 increased the affinity of YBX3 for ZO-1 through the CCAUC motif, resulting in the sequestration of YBX3 in the cytoplasm, inhibiting the association of YBX3 with the PCNA promoter and eventually affecting p21 ubiquitin-mediated degradation. In addition, our results demonstrated that senescence-related downregulation of EIF4A3 gave rise to circSERPINE2. In vivo, intra-articular injection of si-circSerpine2 restrained native joint-resident MSC senescence and cartilage degeneration in mice with aging-related osteoarthritis. Taken together, our findings provide strong evidence for a regulatory role for the circSERPINE2/YBX3/PCNA/p21 axis in MSC senescence and the therapeutic potential of si-circSERPINE2 in alleviating aging-associated syndromes, such as osteoarthritis.

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.

Breast cancer stem cell-derived extracellular vesicles transfer ARRDC1-AS1 to promote breast carcinogenesis via a miR-4731-5p/AKT1 axis-dependent mechanism

OBJECTIVES

Deregulation of long non-coding RNAs (lncRNAs) has been frequently reported in breast cancer (BC). This goes to show the importance of understanding its significant contribution towards breast carcinogenesis. In the present study, we clarified a carcinogenic mechanism based on the ARRDC1-AS1 delivered by breast cancer stem cells-derived extracellular vesicles (BCSCs-EVs) in BC.

METHODS

The isolated and well characterized BCSCs-EVs were co-cultured with BC cells. The expression of ARRDC1-AS1, miR-4731-5p, and AKT1 was determined in BC cell lines. BC cells were assayed for their viability, invasion, migration and apoptosis in vitro by CCK-8, Transwell and flow cytometry, as well as tumor growth in vivo after loss- and gain-of function assays. Dual-luciferase reporter gene, RIP and RNA pull-down assays were performed to determine the interactions among ARRDC1-AS1, miR-4731-5p, and AKT1.

RESULTS

Elevation of ARRDC1-AS1 and AKT1 as well as miR-4731-5p downregulation were observed in BC cells. ARRDC1-AS1 was enriched in BCSCs-EVs. Furthermore, EVs containing ARRDC1-AS1 enhanced the BC cell viability, invasion and migration and glutamate concentration. Mechanistically, ARRDC1-AS1 elevated the expression of AKT1 by competitively binding to miR-4731-5p. ARRDC1-AS1-containing EVs were also found to enhance tumor growth in vivo.

CONCLUSION

Collectively, BCSCs-EVs-mediated delivery of ARRDC1-AS1 may promote the malignant phenotypes of BC cells via the miR-4731-5p/AKT1 axis.

Cardioprotective effects of circ_0002612 in myocardial ischemia/reperfusion injury correlate with disruption of miR-30a-5p-dependent Ppargc1a inhibition

INTRODUCTION

Novel mechanistic insights into the effects of circular RNAs (circRNAs) on the physiology and pathology of cardiovascular diseases are under increasingly active investigation. This study defined the cardioprotective role and mechanistic actions of circ_0002612 in myocardial ischemia/reperfusion injury (MI/RI).

METHODS

MI/RI was induced in mice by ligation of the left anterior descending (LAD) artery followed by reperfusion, and the in vitro model was established in cultured cardiomyocytes under hypoxia/reoxygenation (H/R) conditions. Interaction among circ_0002612, miR-30a-5p, Ppargc1a, and NLRP3 was predicted by bioinformatics analysis and further experimentally identified. Gain- and loss-of-function experiments were performed to evaluate the effect of the circ_0002612/miR-30a-5p/Ppargc1a/NLRP3 axis on the cardiac function and myocardial infarction of I/R-injured mice, as well as viability and apoptosis of H/R-challenged cardiomyocytes.

RESULTS

In the myocardial tissues of MI/RI mice, miR-30a-5p was negatively correlated with circ_0002612 or Ppargc1a, but circ_0002612 was positively correlated with the expression of Ppargc1a. circ_0002612 competitively bound to miR-30a-5p to release expression of its target gene Ppargc1a. circ_0002612 promoted cardiomyocyte viability while suppressing the apoptosis by impairing the miR-30a-5p-mediated inhibition of Ppargc1a. Additionally, Ppargc1a inhibited the expression of NLRP3 and consequently facilitated cardiomyocyte proliferation while suppressing cell apoptosis. By inhibiting the expression of NLRP3, circ_0002612 protected mice from MI/RI.

CONCLUSION

Overall, this study demonstrates the cardioprotective role of circ_0002612 against MI/RI, which may be a viable target for MI/RI.

Resveratrol alleviates preeclampsia-like symptoms in rats through a mechanism involving the miR-363-3p/PEDF/VEGF axis

Preeclampsia (PE) is a hypertension-associated disease, and resveratrol (RES) is a polyphenol recognized to present beneficial effects in cardiovascular disease including hypertension. Recently, attentions have come to the therapeutic effect of RES in PE, but the underlying molecular mechanisms remain largely unknown. This study sought to delineate the mechanistic basis regarding bioinformatically identified miR-363-3p/PEDF/VEGF axis for RES treatment in PE. PE-like symptoms were induced in vivo in Sprague-Dawley rats by intraperitoneal injection with Ng-nitro-L-arginine methyl ester (L-NAME), and hypoxia was induced in vitro in trophoblasts by CoCl₂. Accordingly, RES was found to enhance viability, migration, angiogenesis, and to repress the apoptosis of hypoxic trophoblasts in vitro. Furthermore, in vivo experiments noted that RES alleviated placental injury and promoted angiogenesis in rats with PE-like symptoms in vivo by increasing VEGF via promoting miR-363-3p-mediated PEDF suppression. Collectively, RES ameliorates PE by upregulating VEGF through miR-363-3p-mediated PEDF downregulation, the mechanism of which may be of promising significance to augment RES efficacy in PE treatment.

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.

Low expression of RBP4 in the vitreous humour of patients with proliferative diabetic retinopathy who underwent Conbercept intravitreal injection

Intravitreal injection of anti-VEGF antibodies has been widely used in the treatment of proliferative diabetic retinopathy (PDR). However, anti-VEGF drugs can exacerbate fibrosis and eventually lead to retinal detachment. To explore proteins closely related to fibrosis, we conducted proteomic analysis of human vitreous humour collected from PDR patients who have or have not intravitreal Conbercept (IVC) injection. Sixteen vitreous humour samples from PDR patients with preoperative IVC and 20 samples from those without preoperative IVC were examined. An immunodepletion kit was used to remove high-abundance vitreous proteins. Conbercept-induced changes were determined using a tandem mass tag-based quantitative proteomic strategy. Enzyme-linked immunosorbent assays were performed to confirm the concentrations of selected proteins and validate the proteomic results. Based on a false discovery rate between 0.05% and -0.05% and a fold-change > 1.5, 97 proteins were altered (49 higher levels and 48 lower levels) in response to IVC. Differentially expressed proteins were found in the extracellular and intracellular regions and were found to be involved in VEGF binding and VEGF-activated receptor activity. Protein-protein interactions indicated associations with fibrosis, neovascularisation and inflammatory signalling pathways. We found the low levels of RBP4 in the vitreous humour of PDR patients with IVC injection, as revealed by ELISA and proteomic profiling. Moreover, RBP4 significantly restored the mitochondrial function of HRMECs induced by AGEs and down regulated the level of glycolysis. Our study is the first to report that RBP4 decreases in the vitreous humour of PDR patients who underwent Conbercept treatment, thereby verifying the role of RBP4 in glucose metabolism. Results provide evidence for the potential mechanism underlying Conbercept-related fibrosis.

Transcription Factor YY1 Ameliorates Liver Ischemia-reperfusion Injury Through Modulating the miR-181a-5p/ESR1/ERBB2 Axis

BACKGROUND

Liver ischemia/reperfusion injury (I/RI) is characterized by inflammatory actions. Understanding the mechanistic insights underpinning inflammation is critical to developing treatment strategies. In this study, we illustrated the mechanistic insights of transcription factor Yin-Yang 1 (YY1)-mediated microRNA (miR)-181a-5p/estrogen receptor alpha (ESR1)/epidermal growth factor receptor 2 (ERBB2) axis in liver I/RI.

METHODS

First, we established liver I/RI models in mice and hypoxia-reperfusion (H/R) cell models in mouse hepatocytes (AML12). Subsequently, the expression of YY1, miR-181a-5p, and ESR1 was determined in the 2 models. I/RI mouse models were further injected with lentivirus carrying oe-YY1' and H/R-exposed AML12 cells were subjected to a series of inhibitors, mimics, and shRNAs to validate the mechanisms of YY1 in controlling miR-181a-5p and ESR1 in liver I/RI.

RESULTS

Upregulated expression of miR-181a-5p and downregulated expression of YY1 were identified in the liver tissues of liver I/RI mice and H/R-exposed hepatocytes. Moreover, overexpression of YY1 inhibited the miR-181a-5p expression and thus repressed the H/R-induced hepatocyte apoptosis and inflammation. ESR1 was further validated as a target gene of miR-181a-5p and could be negatively regulated by miR-181a-5p. miR-181a-5p inhibition elevated ESR1 expression, which consequently enhanced the ERBB2 expression and reduced H/R-induced hepatocyte apoptosis and inflammation.

CONCLUSIONS

Overall, these findings highlighted that YY1 repressed the miR-181a-5p expression and stimulated ESR1-mediated activation of ERBB2, thereby ameliorating liver I/RI. This study provides insight into the development of novel targets for liver I/RI.

Silencing lncRNA KCNQ1OT1 reduced hepatic ischemia reperfusion injury-induced pyroptosis by regulating miR-142a-3p/HMGB1 axis

BACKGROUND

Based on pre-existing evidence, KCNQ1OT1 has been pointed out to be closely related to myocardial and cerebral ischemia reperfusion injury diseases. Herein, the objective of our study is to probe into the potential function as well as the underlying mechanism of KCNQ1OT1 on hepatic ischemia reperfusion injury (HIRI).

METHODS

Using C57BL/6 J mice and primary mouse hepatocytes were conducted to establish HIRI model in vivo and in vitro. Cell viability was examined using CCK-8 assay and EdU assay. Flow cytometric analysis was performed to evaluate the pyroptosis. Dual-luciferase reporter assay was employed to verify the interaction relationships. qRT-PCR and Western blot were adopted to analyze the mRNA and protein level. Histopathological alteration of liver tissue was evaluated by HE staining. Immunohistochemistry (IHC) was performed to measure NLRP3 and caspase 1.

RESULTS

Our data revealed that KCNQ1OT1 expression was ascending in hepatic tissue of HIRI mouse. Moreover, deprivation of KCNQ1OT1 mitigated I/R-induced hepatic injury and pyroptosis in vivo. Further experiments demonstrated that silencing KCNQ1OT1 promoted proliferation and inhibited pyroptosis in hypoxia/reoxygenation (H/R)-induced primary mouse hepatocytes. Mechanistically, KCNQ1OT1 functioned as a competing endogenous RNA which sponged miR-142a-3p, therefore promoted HMGB1 expression to activate TLR4/NF-κB signaling pathway in HIRI.

CONCLUSION

LncRNA KCNQ1OT1 elevated HMGB1 expression through binding to miR-142a-3p, thereby promoting pyroptosis in HIRI.

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.

Circ_000829 Plays an Anticancer Role in Renal Cell Carcinoma by Suppressing SRSF1-Mediated Alternative Splicing of SLC39A14

Background

Covalently closed circular RNAs (circRNAs) play critical oncogenic or anticancer roles in various cancers including renal cell carcinoma (RCC), pointing to their regulation as a promising strategy against development of RCC. We, thus, studied the tumor-suppressive role of circ_000829 in RCC through in vitro and in vivo experiments.

Methods

The expression of circ_000829 was validated in clinical RCC tissues and RCC cell lines. Based on ectopic expression and knockdown experiments, we examined the interactions among circ_000829, serine and arginine rich splicing factor 1 (SRSF1), and solute carrier family 39 member 14 (SLC39A14, zinc transporter). Then, the effects of circ_000829, SRSF1, and SLC39A14 on cell cycle distribution and proliferation in vitro and on tumor growth in vivo were evaluated in RCC cells.

Results

Circ_000829 was poorly expressed in RCC tissues and cells, while SRSF1 was highly expressed. Restoration of circ_000829 reduced the levels of SRSF1 and SLC39A14B, thereby repressing the RCC cell proliferation in vitro and tumor growth in vivo. Meanwhile, overexpression of SRSF1 and SLC39A14B promoted the proliferation and cell cycle entry of RCC cells. Mechanistically, circ_000829 directly bound to SRSF1, and SRSF1 enhanced the expression of SLC39A14B by mediating the alternative splicing of SLC39A14. SLC39A14B upregulation negated the effect of SLC39A14 knockdown on RCC cell proliferation.

Conclusion

Hence, this study suggests the antiproliferative role of circ_000829 in RCC growth and further elucidates the underlying mechanism involving the inhibited SRSF1-mediated alternative splicing of SLC39A14 mRNA.

RNA-Seq Reveals the Underlying Molecular Mechanism of First Cleavage Time Affecting Porcine Embryo Development

The selection and evaluation of high-quality embryos are the key factors affecting in vitro embryo development and pregnancy outcome. The timing of first embryonic cleavage has been considered a positive indicator of the in vitro developmental potential of embryos, while the underlying molecular mechanism is still not fully understood. In this study, the embryos generated by parthenogenetic activation (PA) or in vitro fertilization (IVF) were monitored and recorded every 2 h and divided into two groups (early cleavage or late cleavage) based on the cleavage rate and blastocyst formation data. RNA sequencing was used to analyze the gene expression pattern of the embryos. We identified 667 and 71 different expression genes (DEGs) in early cleavage and late cleavage porcine PA and IVF embryos, respectively. Further Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses showed that the DEGs are mainly enriched in pathways concerning the proteasome, DNA repair, cell cycle arrest, autophagy, and apoptosis, suggesting that severe endoplasmic reticulum stress (ERS) and DNA damage may be the key factors that led to the low development potential of late cleavage embryos. This study provides a theoretical basis for the following application and offers important information about the understanding of the timely manner of porcine embryo development.

Role of zonula occludens in gastrointestinal and liver cancers

A growing body of evidence suggests that tight junction (TJ) proteins play a crucial role in the pathogenesis of various diseases, including gastrointestinal (GI) cancer and hepatocellular carcinoma (HCC). TJ proteins primarily maintain the epithelial and endothelial cells intact together through integral proteins however, recent reports suggest that they also regulate gene expression necessary for cell proliferation, angiogenesis, and metastasis through adapter proteins such as zonula occludens (ZO). ZO proteins are membrane-associated cytosolic scaffolding proteins that modulate cell proliferation by interacting with several transcription factors. Reduced ZO proteins in GI cancer and HCC are correlated with tumor development and poor prognosis. Pubmed has searched for using the keyword ZO and gastric cancer, ZO and cancer, and ZO and HCC for the last ten years to date. This review summarized the role of ZO proteins in cell proliferation and their expression in GI cancer and HCC. Furthermore, therapeutic interventions targeting ZO in GI and liver cancers are reviewed.

MicroRNAs: Novel Targets in Hepatic Ischemia–Reperfusion Injury

Hepatic ischemia–reperfusion injury (IRI) is one of the main factors for early allograft dysfunction (EAD), which may lead to graft rejection, graft loss, or shortened graft life in liver transplantation. Hepatic IRI appears to be inevitable during the majority of liver procurement and transportation of donor organs, resulting in a cascade of biological changes. The activation of signaling pathways during IRI results in the up- and downregulation of genes and microRNAs (miRNAs). miRNAs are ~21 nucleotides in length and well-characterized for their role in gene regulations; they have recently been used for therapeutic approaches in addition to their role as biomarkers for many diseases. miRNAs that are associated with hepatic IRI in in vitro and in vivo animal models are comprehensively summarized in this review. In those studies, the manipulation of miRNAs has been shown for the inhibition of aggravated immune response, reduction of apoptosis, stimulation of tissue repair, and enhancement of cell recovery to attenuate liver damage. Therefore, the utilization of liver-specific miRNA holds great potential as a therapeutic agent to improve early allograft dysfunction, hepatic injury, and patient outcome.

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-181a-5p Promotes Osteosarcoma Progression via PTEN/AKT Pathway

Osteosarcoma is the most common primary malignant bone tumor in children and adolescents with poor prognosis. MicroRNA-181a-5p (miR-181a-5p) is involved in the progression of various tumors; however, its role and underlying mechanism in osteosarcoma remains unclear. In this study, we found that miR-181a-5p was upregulated in human osteosarcoma cells and tissues. miR-181a-5p mimic significantly promoted, while miR-181a-5p inhibitor blocked the proliferation, colony formation, migration, invasion, and cell cycle progression of osteosarcoma cells. Mechanistically, miR-181a-5p bound to the 3′-untranslational region of phosphatase and tensin homolog (PTEN) and reduced its protein expression, thereby activating protein kinase B (PKB/AKT) pathway. Either PTEN overexpression or AKT inhibition notably blocked the tumor-promoting effects of miR-181a-5p. Moreover, we observed that miR-181a-5p mimic further inhibited growth of human osteosarcoma cells in the presence of adriamycin or cisplatin. Overall, miR-181a-5p promotes osteosarcoma progression via PTEN/AKT pathway and it is a promising therapeutic target to treat osteosarcoma.

Mesenchymal Stem Cells Derived Extracellular Vesicles Alleviate Traumatic Hemorrhagic Shock Induced Hepatic Injury via IL-10/PTPN22-Mediated M2 Kupffer Cell Polarization

Traumatic hemorrhagic shock (THS) is a major cause of mortality and morbidity worldwide in severely injured patients. Mesenchymal stem cells (MSCs) possess immunomodulatory properties and tissue repair potential mainly through a paracrine pathway mediated by MSC-derived extracellular vesicles (MSC-EVs). Interleukin 10 (IL-10) is a potent anti-inflammatory cytokine that plays a crucial role during the inflammatory response, with a broad range of effects on innate and adaptive immunity, preventing damage to the host and maintaining normal tissue homeostasis. However, the function and mechanism of IL-10 in MSC-mediated protective effect in THS remain obscure. Here, we show that MSCs significantly attenuate hepatic injury and inflammation from THS in mice. Notably, these beneficial effects of MSCs disappeared when IL-10 was knocked out in EVs or when recombinant IL-10 was administered to mice. Mechanistically, MSC-EVs function to carry and deliver IL-10 as cargo. WT MSC-EVs restored the function of IL-10 KO MSCs during THS injury. We further demonstrated that EVs containing IL-10 mainly accumulated in the liver during THS, where they were captured by Kupffer cells and induced the expression of PTPN22. These effects subsequently shifted Kupffer cells to an anti-inflammatory phenotype and mitigated liver inflammation and injury. Therefore, our study indicates that MSC-EVs containing IL-10 alleviate THS-induced hepatic injury and may serve as a cell-free therapeutic approach for THS.

Effect of Edaravone on MicroRNA Expression in Exosomes after Hepatic Ischemia-reperfusion Injury

BACKGROUND AND OBJECTIVE

Hepatic ischemia-reperfusion injury (HIRI) results in serious complications after liver resection and transplantation. Edaravone (ED) has a protective effect on IRI. This study was designed to evaluate whether ED could protect the liver of rats from HIRI injury and explored its exosomal miRNA-related mechanism.

METHODS

The sham group, hepatic ischemia/reperfusion (IR group), and hepatic ischemia/reperfusion + edaravone (ED group) models were established. We determined the protective effect of ED by measuring alanine aminotransferase (ALT), aspartate aminotransferase (AST), malondialdehyde (MDA), superoxide dismutase (SOD); enzyme-linked immunosorbent assay for tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β); hematoxylin-eosin staining and immunohistochemistry for histopathological changes. Exosomal miRNAs were subjected to second-generation sequencing to identify their differential expression. The results were analyzed using bioinformatics methods and validated using real-time quantitative polymerase chain reaction (RT-qPCR).

RESULTS

HIRI rats showed higher levels of ALT, AST, oxidative stress, and inflammatory markers; ED attenuated these effects. The sequencing results showed 6 upregulated and 13 downregulated miRNAs in the IR vs. sham groups, 10 upregulated and 10 downregulated miRNAs in the ED vs. IR groups. PC-3p-190-42101 was screened as an overlapping differentially expressed miRNA, and RT-qPCR validation showed that its expression in HIRI rats was significantly decreased; ED prevented this downregulation. Moreover, the expression of PC-3P-190-42101 was significantly correlated with the level of inflammatory factors.

CONCLUSION

These findings indicate that ED can regulate the level of inflammatory factors by affecting the expression of miRNA PC-3p-190-42101 in plasma exosomes to protect the liver from IRI.

Impact of the Main Cardiovascular Risk Factors on Plasma Extracellular Vesicles and Their Influence on the Heart's Vulnerability to Ischemia-Reperfusion Injury

The majority of cardiovascular deaths are associated with acute coronary syndrome, especially ST-elevation myocardial infarction. Therapeutic reperfusion alone can contribute up to 40 percent of total infarct size following coronary artery occlusion, which is called ischemia-reperfusion injury (IRI). Its size depends on many factors, including the main risk factors of cardiovascular mortality, such as age, sex, systolic blood pressure, smoking, and total cholesterol level as well as obesity, diabetes, and physical effort. Extracellular vesicles (EVs) are membrane-coated particles released by every type of cell, which can carry content that affects the functioning of other tissues. Their role is essential in the communication between healthy and dysfunctional cells. In this article, data on the variability of the content of EVs in patients with the most prevalent cardiovascular risk factors is presented, and their influence on IRI is discussed.

MiR-191-5p Disturbed the Angiogenesis in a Mice Model of Cerebral Infarction by Targeting Inhibition of BDNF

BACKGROUND

miRNAs are crucial regulators of angiogenesis, but there have been no detailed studies on the role of miR-191-5p in cerebral infarct angiogenesis. Here, we investigated the role of miR-191-5p in regulating cerebral infarction angiogenesis.

MATERIAL AND METHODS

Mice were injected intracerebroventricularly with antagomir negative control (NC-antagomir), miR-191-5p antagomir, or pcDNA-BDNF 2 h before middle cerebral artery occlusion (MCAO), followed by neurobehavioral score and foot-fault test. The cerebral infarct volume was performed by TTC staining. The microvessel density was detected by FITC-dextran. RT-qPCR was used to detect the levels of miR-191-5p and its target gene BDNF. Western blotting was applied to detect the protein levels of BDNF. The luciferase reporter assay verified that miR-191-5p targeted BDNF.

RESULTS

We found an increased level of miR-191-5p in the brain tissue of mice to MCAO. Down-regulation of miR-191-5p reduced the infarct volume and ameliorated neurological deficits in MCAO mice. Further investigation showed that miR-191-5p directly targeted BDNF and that the protective effect of miR-191-5p inhibition in angiogenesis was achieved by regulating BDNF.

CONCLUSIONS

Our results indicated that miR-191-5p disturbed the angiogenesis in the mouse models of cerebral infarction by inhibiting BDNF.

Overexpression of lncRNA HULC Attenuates Myocardial Ischemia/reperfusion Injury in Rat Models and Apoptosis of Hypoxia/reoxygenation Cardiomyocytes via Targeting miR-377-5p through NLRP3/Caspase‑1/IL‑1β Signaling Pathway Inhibition

OBJECTIVE

Acute myocardial infarction (AMI) is characterized by myocardial tissue necrosis and activation of inflammatory response. This study aims to elucidate the potential mechanism underlying the protective effects of long non-coding RNA (lncRNA) highly up-regulated in liver cancer (HULC) against myocardial ischemia/reperfusion (I/R) injury in rat models and apoptosis of cardiomyocytes.

METHODS

We firstly established rat models of myocardial I/R injury and rat cardiomyocyte (H9c2 cells) models of hypoxia/reoxygenation (H/R) injury. Sprague-Dawley (SD) neonatal rats were randomized into four groups: sham, I/R, I/R+ microRNA (miR) -377-5p mimic, and I/R+ miR-377-5p antagomir, respectively. Then, histopathological examination was applied. Apoptosis was evaluated by transferase-mediated dUTP nick end labeling (TUNEL) staining. Cell vitality was measured using MTT assay. The concentrations of creatine kinase MB (CK-MB), cardiac troponin I (cTnI), interleukin (IL) -6 (IL-6), and tumor necrosis factor-α (TNF-α) were detected by enzyme-linked immunosorbent assay (ELISA). The expression of Cleaved-Caspase-3, Caspase-3, NOD-like receptor P3 (NLRP3), Caspase-1, and IL-1β was analyzed by immunohistochemical (IHC) or Western blot analysis.

RESULTS

We found that HULC was downregulated and miR-377-5p was upregulated in IR-injured myocardial tissue and the H/R-induced H9c2 cell. Overexpression of miR-377-5p increased myocardial dysfunction and apoptosis and activated formation and secretion of IL-6 and TNF-α. The preprocessing of miR-377-5p silencing emerged opposite results. Strikingly, dual luciferase reporter assay showed that HULC was a sponge of miR-377-5p. Subsequently, mechanism experiments revealed that NLRP3/Caspase‑1/IL‑1β was a target axis of miR-377-5p. In vitro, the protective effect of HULC overexpression on H9c2 cell viability and inflammation was offset by miR-377-5p silencing. Finally, rescue assay suggested that HULC-miR-377-5p -NLRP3/Caspase‑1/IL‑1β axis regulated the apoptosis and inflammation of H/R-induced H9c2 cells.

CONCLUSIONS

Overall, these results indicate that the protective effect of HULC against myocardial I/R injury and H/R cardiomyocyte apoptosis partially relies on the inhibition of NLRP3/Caspase‑1/IL‑1β signaling pathway.

Inhibition of microRNA-297 alleviates THLE-2 cell injury induced by hypoxia/reoxygenation by inhibiting NLRP3 inflammasome activation via SIRT3

It has been acknowledged that microRNAs (miRNAs/miRs) assume a critical role in hypoxia/reoxygenation (H/R)-induced hepatocyte injury. Therefore, cell experiments were performed in this study to investigate the mechanism of miR-297 in H/R-induced hepatocyte injury with the involvement of Sirtuin 3 (SIRT3) and NLRP3. Initially, THLE-2 cells were utilized for H/R challenge. After miR-297 antagomir and NLRP3 adenovirus vector delivery, THLE-2 cell proliferation and apoptosis were measured by MTT, EdU and TUNEL assays, respectively. Enzyme-linked immunosorbent assay was conducted to evaluate the levels of apoptosis-related indicators (Bax and Bcl-2) and inflammation-related indicators (IL-6 and IL-10), western blot analysis to detect NLRP3 and Cleaved Caspase-1 expression. The binding relation between miR-297 and SIRT3 was examined using dual-luciferase assay. The results showed that miR-297 antagomir repressed the apoptosis and inflammation induced by H/R treatment in THLE-2 cells. Mechanistically, miR-297 antagomir diminished the extent of IκBα and NF-κB phosphorylation and NLRP3 activation in H/R-induced THLE-2 cells by targeting SIRT3. Furthermore, NLRP3 overexpression normalized the promoting effects of miR-297 antagomir on proliferation and its inhibitory effects on apoptosis and inflammation in H/R-induced THLE-2 cells. In summary, our results elucidated that miR-297 antagomir repressed H/R-induced THLE-2 cell injury via SIRT3 promotion and NLRP3 inactivation.

MicroRNA-23a-5p Is Involved in the Regulation of Lipopolysaccharide-Induced Acute Lung Injury by Targeting HSP20/ASK1

Inflammation and oxidative stress contribute to the progression of acute lung injury (ALI). MicroRNA-23a-5p (miR-23a-5p) has been reported to regulate inflammation and oxidative stress; however, its role in ALI is still poorly elucidated. Mice were intravenously treated with the miR-23a-5p antagomir, agomir, or the negative controls for 3 consecutive days and then received a single intratracheal injection of lipopolysaccharide (LPS, 5 mg/kg) to induce ALI. Pulmonary function, bronchoalveolar lavage fluids (BALFs), arterial blood gas, and molecular biomarkers associated with inflammation and oxidative stress were analyzed. In addition, murine peritoneal macrophages were isolated and treated with LPS to verify the role of miR-23a-5p in vitro. We detected an elevation of miR-23a-5p expression in the lungs from ALI mice. The miR-23a-5p antagomir was prevented, whereas the miR-23a-5p agomir aggravated inflammation, oxidative stress, lung tissue injury, and pulmonary dysfunction in LPS-treated mice. Besides, the miR-23a-5p antagomir also reduced the productions of proinflammatory cytokines and free radicals in LPS-treated primary macrophages, which were further augmented in cells following the miR-23a-5p agomir treatment. Additional findings demonstrated that the miR-23a-5p agomir exacerbated LPS-induced ALI via activating apoptosis signal-regulating kinase 1 (ASK1), and that pharmacological or genetic inhibition of ASK1 significantly repressed the deleterious effects of the miR-23a-5p agomir. Moreover, we proved that the miR-23a-5p agomir activated ASK1 via directly reducing heat shock protein 20 (HSP20) expression. miR-23a-5p is involved in the regulation of LPS-induced inflammation, oxidative stress, lung tissue injury, and pulmonary dysfunction by targeting HSP20/ASK1, and it is a valuable therapeutic candidate for the treatment of ALI.

MicroRNA-302a-3p induces ferroptosis of non-small cell lung cancer cells via targeting ferroportin

Ferroptosis is a newly described regulated form of cell death that contributes to the progression of non-small cell lung cancers (NSCLCs). MicroRNA-302a-3p (miR-302a-3p) plays critical roles in the tumorigenicity of different cancers; however, its function and underlying mechanism in ferroptosis and NSCLCs remain unclear. Human NSCLCs cells were incubated with miR-302a-3pmimic or inhibitor in the presence or absence of erastin or RSL3. Cell viability, colony numbers, lactate dehydrogenase (LDH) releases, lipid peroxidation and intracellular iron level were measured. Besides, the synergistic effects of cisplatin and paclitaxel with miR-302a-3p were determined. miR-302a-3p level was reduced in human NSCLCs cells and tissues. ThemiR-302a-3p mimic induced lipid peroxidation, iron overload and ferroptosis, thereby inhibiting cell growth and colony formation of NSCLCs cells. Conversely, the miR-302a-3p inhibitor block ederastin- or RSL3-related ferroptosis and tumor suppression. Additionally, we found that miR-302a-3p directly bound to the 3'-untranslational region of ferroportin to decrease its protein expression, and that ferroportin overexpression significantly prevented miR-302a-3p mimic-induced ferroptosis and tumor inhibition. Moreover, the miR-302a-3p mimic sensitized NSCLCs cells to cisplatin and paclitaxel chemotherapy. miR-302a-3p functions as a tumor inhibitor, at least partly, via targeting ferroportin to induce ferroptosis of NSCLCs.

A novel microRNA-based prognostic model outperforms standard prognostic models in patients with acetaminophen-induced acute liver failure

BACKGROUND & AIMS

Acetaminophen (APAP)-induced acute liver failure (ALF) remains the most common cause of ALF in the Western world. Conventional prognostic models, utilising markers of liver injury and organ failure, lack sensitivity for mortality prediction. We previously identified a microRNA signature that is associated with successful regeneration post-auxiliary liver transplant and with recovery from APAP-ALF. Herein, we aimed to use this microRNA signature to develop outcome prediction models for APAP-ALF.

METHODS

We undertook a nested, case-control study using serum samples from 194 patients with APAP-ALF enrolled in the US ALF Study Group registry (1998-2014) at early (day 1-2) and late (day 3-5) time-points. A microRNA qPCR panel of 22 microRNAs was utilised to assess microRNA expression at both time-points. Multiple logistic regression was used to develop models which were compared to conventional prognostic models using the DeLong method.

RESULTS

Individual microRNAs confer limited prognostic value when utilised in isolation. However, incorporating them within microRNA-based outcome prediction models increases their clinical utility. Our early time-point model (AUC = 0.78, 95% CI 0.71-0.84) contained a microRNA signature associated with liver regeneration and our late time-point model (AUC = 0.83, 95% CI 0.76-0.89) contained a microRNA signature associated with cell-death. Both models were enhanced when combined with model for end-stage liver disease (MELD) score and vasopressor use and both outperformed the King's College criteria. The early time-point model combined with clinical parameters outperformed the ALF Study Group prognostic index and the MELD score.

CONCLUSIONS

Our findings demonstrate that a regeneration-linked microRNA signature combined with readily available clinical parameters can outperform existing prognostic models for ALF in identifying patients with poor prognosis who may benefit from transplantation.

LAY SUMMARY

While acute liver failure can be reversible, some patients will die without a liver transplant. We show that blood test markers that measure the potential for liver recovery may help improve identification of patients unlikely to survive acute liver failure who may benefit from a liver transplant.

Rational construction of a reversible arylazo-based NIR probe for cycling hypoxia imaging in vivo

Reversible NIR luminescent probes with negligible photocytotoxicity are required for long-term tracking of cycling hypoxia in vivo. However, almost all of the reported organic fluorescent hypoxia probes reported until now were irreversible. Here we report a reversible arylazo-conjugated fluorescent probe (HDSF) for cycling hypoxia imaging. HDSF displays an off-on fluorescence switch at 705 nm in normoxia-hypoxia cycles. Mass spectroscopic and theoretical studies confirm that the reversible sensing behavior is attributed to the two electron-withdrawing trifluoromethyl groups, which stabilizes the reduction intermediate phenylhydrazine and blocks the further reductive decomposition. Cycling hypoxia monitoring in cells and zebrafish embryos is realized by HDSF using confocal imaging. Moreover, hypoxic solid tumors are visualized and the ischemia-reperfusion process in mice is monitored in real-time. This work provides an effective strategy to construct organic fluorescent probes for cycling hypoxia imaging and paves the way for the study of cycling hypoxia biology.

Foxo1-induced miR-92b down-regulation promotes blood-brain barrier damage after ischaemic stroke by targeting NOX4

The blood‐brain barrier (BBB) damage is a momentous pathological process of ischaemic stroke. NADPH oxidases 4 (NOX4) boosts BBB damage after ischaemic stroke and its expression can be influenced by microRNAs. This study aimed to probe into whether miR‐92b influenced the BBB damage after ischaemic stroke by regulating NOX4 expression. Here, miR‐92b expression was lessened in the ischaemic brains of rats and oxygen‐glucose deprivation (OGD)‐induced brain microvascular endothelial cells (BMECs). In middle cerebral artery occlusion (MCAo) rats, miR‐92b overexpression relieved the ameliorated neurological function and protected the BBB integrity. In vitro model, miR‐92b overexpression raised the viability and lessened the permeability of OGD‐induced BMECs. miR‐92b targeted NOX4 and regulated the viability and permeability of OGD‐induced BMECs by negatively modulating NOX4 expression. The transcription factor Foxo1 bound to the miR‐92b promoter and restrained its expression. Foxo1 expression was induced by OGD‐induction and its knockdown abolished the effects of OGD on miR‐92b and NOX4 expressions, cell viability and permeability of BMECs. In general, our findings expounded that Foxo1‐induced lessening miR‐92b boosted BBB damage after ischaemic stroke by raising NOX4 expression.

Sevoflurane Postconditioning Attenuates Hepatic Ischemia-Reperfusion Injury by Limiting HMGB1/TLR4/NF-κB Pathway via Modulating microRNA-142 in vivo and in vitro

Preconditioning of sevoflurane (Sevo) has been demonstrated to protect the liver from ischemia/reperfusion (I/R) injury. However, it is unknown whether it has hepatoprotective when given at the onset of reperfusion (postconditioning), a protocol with more clinical impact. The present study aimed to explore the hepatoprotective effects of Sevo postconditioning against hepatic IR injury in vivo and in vitro and the possible mechanisms. Using a mouse model of hepatic I/R, Sevo postconditioning significantly improved hepatic injury after reperfusion, as demonstrated by reduced AST, ALT, and LDH serum levels and reduced histologic damage in liver tissues. Furthermore, Sevo postconditioning could suppress the apoptosis, inhibit oxidative stress and inflammatory response in liver tissue of HIRI mice, as well as improve the survival rate of HIRI mice. Through analyzing GSE72314 from the gene expression omnibus (GEO) database, it was demonstrated that microRNA (miR)-142 is downregulated by HIRI, which was reversed by Sevo treatment. Further investigation showed that agomiR-142 injection could enhance the hepatoprotective effects of Sevo postconditioning on I/R injury, while antagomiR-142 reversed these effects in mice. Notably, high mobility group box 1 (HMGB1), an important inflammatory factor, was directly targeted by miR-142 in hepatic cells, and we further found that Sevo could inhibit the expression of HMGB1 through up-regulating miR-142 expression in HIRI mice model. In addition, we found that I/R injury induced the activation of TLR4/NF-κB inflammatory pathway was partially suppressed by Sevo postconditioning, and miR-142 mediated the regulatory role of Sevo postconditioning. In line with the in vivo results, Sevo treatment improved the cell viability, inhibited cell apoptosis, oxidative stress and inflammatory response in vitro HIRI model, while these effects were reversed by antagomiR-142 transfection. Collectively, our findings demonstrated that Sevo postconditioning counteracts the downregulation of miR-142 provoked by I/R, in turn decreased the expression of HMGB1, blocking TLR4/NF-κB pathway activation, thus improving hepatic I/R injury. Our data suggest that Sevo may be a valuable alternative anaesthetic agent in liver transplantation and major liver surgeries.

miR-194-5p protects against myocardial ischemia/reperfusion injury via MAPK1/PTEN/AKT pathway

Background

MicroRNA (miRNA), which participates in various physiological and pathological processes, is a highly conserved small RNA sequence. This study aimed to investigate the role of miR-194-5p in hypoxia/reoxygenation (H/R)-induced cardiomyocyte apoptosis and myocardial ischemia/reperfusion (I/R) injury.

Methods

We set up an H/R H9c2 cell model in vitro and an I/R mouse model in vivo. Then, cell vitality, apoptosis, and histopathological evaluation were conducted. Reactive oxygen species (ROS) generation and the activity of superoxide dismutase (SOD) and malondialdehyde (MDA) were examined by 2’,7’-Dichlorodihydrofluorescein diacetate (H2DCFDA), and enzyme-linked immunosorbent assay (ELISA), respectively. The level of creatine kinase isoenzyme (CK-MB), cardiac troponin I (cTnI), myoglobin (Mb) is examined by ELISA. The expression of Caspase-3, cleaved-Caspase-3, Bax, Bcl-2, phosphatase and tensin homolog deleted on chromosome ten (PTEN), and protein kinase B (AKT) was analyzed by western blot.

Results

Data showed the expression of miR-194-5p was decreased in H/R-induced H9c2 cells and I/R-induced mouse. Conversely, overexpression of miR-194-5p could improve cardiomyocyte damage in ischemic models in vivo and in vitro. Furthermore, mitogen-activated protein kinase 1 (MAPK1) was found as a direct target of miR-194-5p, which negatively regulated the expression of MAPK1. The up-regulation of MAPK1 inhibited the myocardial protection previously observed by miR-194-5p.

Conclusions

Our study shows overexpression of miR-194-5p protects against H/R injury in vitro and cardiac I/R injury in vivo, which involves the inhibition of cardiac apoptosis and oxidative stress by targeting MAPK1 expression via PTEN/AKT pathway. These findings supply novel insights into potential therapeutic targets for cardiovascular diseases.

miR-210 Participates in Hepatic Ischemia Reperfusion Injury by Forming a Negative Feedback Loop With SMAD4

BACKGROUND AND AIMS

Hepatic ischemia-reperfusion (IR) injury is a major complication of liver transplantation, resection, and hemorrhagic shock. Hypoxia is a key pathological event associated with IR injury. MicroRNA-210 (miR-210) has been characterized as a micromanager of hypoxia pathway. However, its function and mechanism in hepatic IR injury is unknown.

APPROACH AND RESULTS

In this study, we found miR-210 was induced in liver tissues from patients subjected to IR-related surgeries. In a murine model of hepatic IR, the level of miR-210 was increased in hepatocytes but not in nonparenchymal cells. miR-210 deficiency remarkably alleviated liver injury, cell inflammatory responses, and cell death in a mouse hepatic IR model. In vitro, inhibition of miR-210 decreased hypoxia/reoxygenation (HR)-induced cell apoptosis of primary hepatocytes and LO2 cells, whereas overexpression of miR-210 increased cells apoptosis during HR. Mechanistically, miR-210 directly suppressed mothers against decapentaplegic homolog 4 (SMAD4) expression under normoxia and hypoxia condition by directly binding to the 3' UTR of SMAD4. The pro-apoptotic effect of miR-210 was alleviated by SMAD4, whereas short hairpin SMAD4 abrogated the anti-apoptotic role of miR-210 inhibition in primary hepatocytes. Further studies demonstrated that hypoxia-induced SMAD4 transported into nucleus, in which SMAD4 directly bound to the promoter of miR-210 and transcriptionally induced miR-210, thus forming a negative feedback loop with miR-210.

CONCLUSIONS

Our study implicates a crucial role of miR-210-SMAD4 interaction in hepatic IR-induced cell death and provides a promising therapeutic approach for liver IR injury.

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.

MicroRNA-31-5p Exacerbates Lipopolysaccharide-Induced Acute Lung Injury via Inactivating Cab39/AMPKα Pathway

Acute lung injury (ALI) and the subsequent acute respiratory distress syndrome remain devastating diseases with high mortality rates and poor prognoses among patients in intensive care units. The present study is aimed at investigating the role and underlying mechanisms of microRNA-31-5p (miR-31-5p) on lipopolysaccharide- (LPS-) induced ALI. Mice were pretreated with miR-31-5p agomir, antagomir, and their negative controls at indicated doses for 3 consecutive days, and then they received a single intratracheal injection of LPS (5 mg/kg) for 12 h to induce ALI. MH-S murine alveolar macrophage cell lines were cultured to further verify the role of miR-31-5p in vitro. For AMP-activated protein kinase α (AMPKα) and calcium-binding protein 39 (Cab39) inhibition, compound C or lentiviral vectors were used in vivo and in vitro. We observed an upregulation of miR-31-5p in lung tissue upon LPS injection. miR-31-5p antagomir alleviated, while miR-31-5p agomir exacerbated LPS-induced inflammation, oxidative damage, and pulmonary dysfunction in vivo and in vitro. Mechanistically, miR-31-5p antagomir activated AMPKα to exert the protective effects that were abrogated by AMPKα inhibition. Further studies revealed that Cab39 was required for AMPKα activation and pulmonary protection by miR-31-5p antagomir. We provide the evidence that endogenous miR-31-5p is a key pathogenic factor for inflammation and oxidative damage during LPS-induced ALI, which is related to Cab39-dependent inhibition of AMPKα.

Triterpenoids Extracted From Antrodia cinnamomea Mycelia Attenuate Acute Alcohol-Induced Liver Injury in C57BL/6 Mice via Suppression Inflammatory Response

Excessive alcohol consumption causes liver injury–induced mortality. Here we systematically analyzed the structure of triterpenoids extracted from Antrodia cinnamomea mycelia (ACT) and investigated their protective effects against acute alcohol-induced liver injury in mice. Liquid chromatography–mass spectrometry and liquid chromatography with tandem mass spectrometry were performed to determine the structures of ACT constituents. Alcohol-induced liver injury was generated in C57BL/6 mice by oral gavage of 13 g/kg white spirit (a wine at 56% ABV). Mice were treated with either silibinin or ACT for 2 weeks. Liver injury markers and pathological signaling were then quantified with enzyme-linked immunosorbent assays, antibody array assays, and Western blots, and pathological examinations were performed using hematoxylin-eosin staining and periodic acid–Schiff staining. Triterpenoids extracted from A. cinnamomea mycelia contain 25 types of triterpenoid compounds. A 2-weeks alcohol consumption treatment caused significant weight loss, liver dyslipidemia, and elevation of alanine aminotransferase, aspartate aminotransferase, γ-glutamyl transferase, and alkaline phosphatase activities in the serum and/or liver. These effects were markedly reversed after 2-weeks ACT administration. Triterpenoids extracted from A. cinnamomea mycelia alleviated the organ structural changes and inflammatory infiltration of alcohol-damaged tissues. Triterpenoids extracted from A. cinnamomea mycelia inhibited proinflammatory cytokine levels and enhanced anti-inflammatory cytokine levels. Acute alcohol treatment promoted inflammation with significant correlations to hypoxia-inducible factor 1α (HIF-1α), which was reduced by ACT and was partially related to modulation of the protein kinase B (Akt)/70-kDa ribosomal protein S6 kinase phosphorylation (p70S6K) and Wnt/β-catenin signaling pathways. In conclusion, ACT protected against acute alcohol-induced liver damage in mice mainly through its suppression of the inflammatory response, which may be related to HIF-1α signaling.

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.

The regulatory role of HIF-1 in tubular epithelial cells in response to kidney injury

The high sensitivity to changes in oxygen tension makes kidney vulnerable to hypoxia. Both acute kidney injury and chronic kidney disease are almost always accompanied by hypoxia. Tubular epithelial cells (TECs), the dominant intrinsic cells in kidney tissue, are believed to be not only a victim in the pathological process of various kidney diseases, but also a major contributor to kidney damage. Hypoxia inducible factor-1 (HIF-1) is the main regulator of adaptive response of cells to hypoxia. Under various clinical and experimental kidney disease conditions, HIF-1 plays a pivotal role in modulating multiple cellular processes in TECs, including apoptosis, autophagy, inflammation, metabolic pattern alteration, and cell cycle arrest. A comprehensive understanding of the mechanisms by which HIF-1 regulates these cellular processes in TECs may help identify potential therapeutic targets to improve the outcome of acute kidney injury and delay the progression of chronic kidney disease.

MiR-191 inhibit angiogenesis after acute ischemic stroke targeting VEZF1

Acute ischemic stroke (AIS) is a major public health problem in China. Impaired angiogenesis plays crucial roles in the development of ischemic cerebral injury. Recent studies have identified that microRNAs (miRNAs) are important regulators of angiogenesis, but little is known the exact effects of angiogenesis-associated miRNAs in AIS. In the present study, we detected the expression levels of angiogenesis-associated miRNAs in AIS patients, middle cerebral artery occlusion (MCAO) rats, and oxygen-glucose deprivation/reoxygenation (OGD/R) human umbilical vein endothelial cells (HUVECs). MiR-191 was increased in the plasma of AIS patients, OGD/R HUVECs, and the plasma and brain of MCAO rats. Over-expression of miR-191 promoted apoptosis, but reduced the proliferation, migration, tube-forming and spheroid sprouting activity in HUVECs OGD/R model. Mechanically, vascular endothelial zinc finger 1 (VEZF1) was identified as the direct target of miR-191, and could be regulated by miR-191 at post-translational level. In vivo studies applying miR-191 antagomir demonstrated that inhibition of miR-191 reduced infarction volume in MCAO rats. In conclusion, our data reveal a novel role of miR-191 in promoting ischemic brain injury through inhibiting angiogenesis via targeting VEZF1. Therefore, miR-191 may serve as a biomarker or a therapeutic target for AIS.

miR-214 Down-Regulation Promoted Hypoxia/Reoxygenation-Induced Hepatocyte Apoptosis Through TRAF1/ASK1/JNK Pathway

OBJECTIVE

This study investigated the role of miR-214 in the hepatocyte apoptosis induced by hypoxia/reoxygenation (H/R) injury.

MATERIALS AND METHODS

In vivo hepatic ischemia/reperfusion (HIR) injury, mice model and in vitro HR model were established. miR-214, TRAF1, ASK1, and JNK expression levels were detected by qRT-PCR and western blot. The apoptosis of mouse hepatocyte AML12 was detected by flow cytometry analysis. The interaction between miR-214 and TRAF1 was confirmed by dual-luciferase reporter gene assay.

RESULTS

Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were elevated in HIR injury mice compared with sham mice. miR-214 expression was down-regulated in liver tissues of HIR and H/R-induced hepatocytes, whereas TRAF1, ASK1, and JNK expressions were up-regulated in HIR and H/R groups. H/R stimulation promoted the apoptosis of hepatocytes, and miR-214 overexpression inhibited the apoptosis of hepatocytes. Besides, TRAF1 was a target of miR-214 and negatively regulated by miR-214. miR-214/TRAF1 pathway involved in the modulation of H/R-induced apoptosis of hepatocytes. In vivo study proved miR-214 reduced hepatic injury of HIR mice.

CONCLUSION

miR-214 overexpression reduces hepatocyte apoptosis after HIR injury through negatively regulating TRAF1/ASK1/JNK pathway.