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

LncRNA ENSGALG00000021686 regulates fat metabolism in chicken hepatocytes via miR-146b/AGPAT2 pathway

The liver contributes to lipid metabolism as the hub of fat synthesis. Long non-coding RNAs (lncRNAs) are considered the regulators of cellular processes. Since LncRNA ENSGALG00000021686 (lncRNA 21 686) has been described as a regulator of lipid metabolism, the present study aimed to clarify the role of lncRNA 21 686 in chicken hepatocytes' lipid metabolism. Thirty-two chickens were divided into four groups and were treated with diets containing different amounts of fat, and the hepatic expression of lncRNA 21 686 and miR-146b along with the levels of proteins involved in the regulation of fat metabolism, lipid indices and oxidative stress were measured. Moreover, primary chicken hepatocytes were transfected with lncRNA 21 686 small interfering RNA or microRNA (miRNA, miR)-146b mimics to measure the consequences of suppressing lncRNA or inducing miRNA expression on the levels of proteins involved in fat metabolism and stress markers. The results showed that the high-fat diet modulated the expression of lncRNA 21 686 and miR-146b (p-value < 0.001). Moreover, there was a significant increase in 1-acyl-sn-glycerol-3-phosphate acyltransferase 2 (AGPAT2) gene expression and protein levels and modulated fat-related markers. Furthermore, the results showed that lncRNA 21 686 suppression reduced the expression of AGPAT2 and its downstream proteins (p-value < 0.05). Overexpression of miR-146b regulated fat metabolism indicator expression. Transfection experiments revealed that lncRNA 21 686 suppression increased miR-146b expression. The findings suggested a novel mechanism containing lncRNA 21 686/miR-146b/AGPAT2 in the regulation of fat metabolism in chicken hepatocytes.

Targeting TAOK1 with resveratrol inhibits esophageal squamous cell carcinoma growth in vitro and in vivo

The worldwide incidence and mortality rates of esophageal squamous cell carcinoma (ESCC) have increased over the last decade. Moreover, molecular targets that may benefit the therapeutics of patients with ESCC have not been fully characterized. Our study discovered that thousand and one amino-acid protein kinase 1 (TAOK1) is highly expressed in ESCC tumor tissues and cell lines. Knock-down of TAOK1 suppresses ESCC cell proliferation in vitro and patient-derived xenograft or cell-derived xenograft tumors growth in vivo. Moreover, TAOK1 overexpression promotes ESCC growth in vitro and in vivo. Additionally, we identified that the natural small molecular compound resveratrol binds to TAOK1 directly and diminishes the kinase activity of TAOK1. Targeting TAOK1 directly with resveratrol significantly inhibits cell proliferation, induces cell cycle arrest and apoptosis, and suppresses tumor growth in ESCC. Furthermore, the silencing of TAOK1 or the application of resveratrol attenuated the activation of TAOK1 downstream signaling effectors. Interestingly, combining resveratrol with paclitaxel, cisplatin, or 5-fluorouracil synergistically enhanced their therapeutic effects against ESCC. In conclusion, this work illustrates the underlying oncogenic function of TAOK1 and provides a theoretical basis for the application of targeting TAOK1 therapy to the clinical treatment of ESCC.

Exploring Cardiac Exosomal RNAs of Acute Myocardial Infarction

BACKGROUND

Myocardial infarction (MI), often a frequent symptom of coronary artery disease (CAD), is a leading cause of death and disability worldwide. Acute myocardial infarction (AMI), a major form of cardiovascular disease, necessitates a deep understanding of its complex pathophysiology to develop innovative therapeutic strategies. Exosomal RNAs (exoRNA), particularly microRNAs (miRNAs) within cardiac tissues, play a critical role in intercellular communication and pathophysiological processes of AMI.

METHODS

This study aimed to delineate the exoRNA landscape, focusing especially on miRNAs in animal models using high-throughput sequencing. The approach included sequencing analysis to identify significant miRNAs in AMI, followed by validation of the functions of selected miRNAs through in vitro studies involving primary cardiomyocytes and fibroblasts.

RESULTS

Numerous differentially expressed miRNAs in AMI were identified using five mice per group. The functions of 20 selected miRNAs were validated through in vitro studies with primary cardiomyocytes and fibroblasts.

CONCLUSIONS

This research enhances understanding of post-AMI molecular changes in cardiac tissues and investigates the potential of exoRNAs as biomarkers or therapeutic targets. These findings offer new insights into the molecular mechanisms of AMIs, paving the way for RNA-based diagnostics and therapeutics and therapies and contributing to the advancement of cardiovascular medicine.

Cortical miR-709 links glutamatergic signaling to NREM sleep EEG slow waves in an activity-dependent manner

MicroRNAs (miRNAs) are key post-transcriptional regulators of gene expression that have been implicated in a plethora of neuronal processes. Nevertheless, their role in regulating brain activity in the context of sleep has so far received little attention. To test their involvement, we deleted mature miRNAs in post-mitotic neurons at two developmental ages, i.e., in early adulthood using conditional Dicer knockout (cKO) mice and in adult mice using an inducible conditional Dicer cKO (icKO) line. In both models, electroencephalographic (EEG) activity was affected and the response to sleep deprivation (SD) altered; while the rapid-eye-movement sleep (REMS) rebound was compromised in both, the increase in EEG delta (1 to 4 Hz) power during non-REMS (NREMS) was smaller in cKO mice and larger in icKO mice compared to controls. We subsequently investigated the effects of SD on the forebrain miRNA transcriptome and found that the expression of 48 miRNAs was affected, and in particular that of the activity-dependent miR-709. In vivo inhibition of miR-709 in the brain increased EEG power during NREMS in the slow-delta (0.75 to 1.75 Hz) range, particularly after periods of prolonged wakefulness. Transcriptome analysis of primary cortical neurons in vitro revealed that miR-709 regulates genes involved in glutamatergic neurotransmission. A subset of these genes was also affected in the cortices of sleep-deprived, miR-709-inhibited mice. Our data implicate miRNAs in the regulation of EEG activity and indicate that miR-709 links neuronal activity during wakefulness to brain synchrony during sleep through the regulation of glutamatergic signaling.

Potential implications of protein kinase Cα in pathophysiological conditions and therapeutic interventions

PKCα is a molecule with many functions that play an important role in cell survival and death to maintain cellular homeostasis. Alteration in the normal functioning of PKCα is responsible for the complicated etiology of many pathologies, including cancer, cardiovascular diseases, kidney complications, neurodegenerative diseases, diabetics, and many others. Several studies have been carried out over the years on this kinase's function, and regulation in normal physiology and pathological conditions. A lot of data with antithetical results have therefore accumulated over time to create a complex framework of physiological implications connected to the PKCα function that needs comprehensive elucidation. In light of this information, we critically analyze the multiple roles played by PKCα in basic cellular processes and their molecular mechanism during various pathological conditions. This review further discusses the current approaches to manipulating PKCα signaling amplitude in the patient's favour and proposed PKCα as a therapeutic target to reverse pathological states.

The microRNomes of Chinese hamster ovary (CHO) cells and their extracellular vesicles, and how they respond to osmotic and ammonia stress

A new area of focus in Chinese hamster ovary (CHO) biotechnology is the role of small (exosomes) and large (microvesicles or microparticles) extracellular vesicles (EVs). CHO cells in culture exchange large quantities of proteins and RNA through these EVs, yet the content and role of these EVs remain elusive. MicroRNAs (miRs or miRNA) are central to adaptive responses to stress and more broadly to changes in culture conditions. Given that EVs are highly enriched in miRs, and that EVs release large quantities of miRs both in vivo and in vitro, EVs and their miR content likely play an important role in adaptive responses. Here we report the miRNA landscape of CHO cells and their EVs under normal culture conditions and under ammonia and osmotic stress. We show that both cells and EVs are highly enriched in five miRs (among over 600 miRs) that make up about half of their total miR content, and that these highly enriched miRs differ significantly between normal and stress culture conditions. Notable is the high enrichment in miR-92a and miR-23a under normal culture conditions, in contrast to the high enrichment in let-7 family miRs (let-7c, let-7b, and let-7a) under both stress conditions. The latter suggests a preserved stress-responsive function of the let-7 miR family, one of the most highly preserved miR families across species, where among other functions, let-7 miRs regulate core oncogenes, which, depending on the biological context, may tip the balance between cell cycle arrest and apoptosis. While the expected-based on their profound enrichment-important role of these highly enriched miRs remains to be dissected, our data and analysis constitute an important resource for exploring the role of miRs in cell adaptation as well as for synthetic applications.

TAOK1 Promotes Proliferation and Invasion of Non-Small-Cell Lung Cancer Cells by Inhibition of WWC1

Background

For patients with advanced non-small-cell lung cancer (NSCLC), targeted therapy significantly improves the therapeutic effect of NSCLC patients. With the development of molecular targeted therapy, more and more NSCLC-related genes have been found. Thousand and one amino-acid kinase 1 (TAOK1) has been identified as a potential target for drug research in various cancers. The main objective of this study was to explore the expression and function of TAOK1 in NSCLC.

Methods

Western blotting was employed to assess TAOK1 expression in NSCLC cell lines. The effects of TAOK1 on biological behaviors, including proliferation, invasion, and apoptosis of NSCLC cells, were assessed. The relationship between TAOK1 and WW and C2 domain containing 1 (WWC1) was assessed by Co-IP assay. The subcutaneous injection of tumor cells in nude mice was used to verify it in vivo.

Results

As expected, TAOK1 was increased in NSCLC cell lines. Following TAOK1 knockdown, NSCLC cells exhibited a significant decrease in the invasion and increased apoptosis in vitro. Instead, the TAOK1 elevation showed the opposite results. The Co-IP assay identified that TAOK1 specifically interacted with WWC1. Knockdown of WWC1 overturned TAOK1 silencing-mediated malignant phenotype of NSCLC cells. Additionally, subcutaneous tumorigenesis assays in nude mice confirmed that TAOK1 knockdown markedly restrained the proliferation capacity of NSCLC cells in vivo.

Conclusion

Surprisingly, TAOK1 overexpression in NSCLC promotes tumor cell growth and invasion, which is associated with downregulation of its downstream protein WWC1, and this result might provide a robust research basis to inquire about the precise therapeutic targets for NSCLC.

Suppression of lncRNA Gm47283 attenuates myocardial infarction via miR-706/ Ptgs2/ferroptosis axis

Myocardial infarction (MI) is the leading cause of sudden death. Long non-doing RNAs (lncRNAs) were demonstrated to play crucial roles in multiple diseases, including cancer and cardiovascular diseases. Nevertheless, the molecular mechanism of lncNRAs in MI is unclear. In this study, we integrated bioinformatics and molecular biological experiments to identify the novel lncRNA transcripts and elucidated its regulatory mechanism in MI. First, we identified 10 dysregualted lncRNAs and found that lncRNA Gm47283 was the top risk factor in MI. Bioinformatics analysis predicted that lncRNA Gm47283 exerted function via targeting miR-706 and Ptgs2. Ptgs2 was also the known regulator of ferroptosis. Inhibition or overexpression of lncRNA Gm47283 could regulate Ptgs2 expression and downstream ferroptosis activity. Overexpression of miR-706 could inhibit the expression of Ptgs2 and the activity of ferroptosis, thereby attenuated cellular injury. Mechanically, co-transfection experiments showed that overexpression of miR-706 could reverse the damage effect that was caused by lncRNA Gm47283 overexpression, via inhibiting Ptgs2 and ferroptosis. Additionally, inhibition of lncRNA Gm47283 by stem cell membrane coated siRNA could attenuate MI in vivo. Our study elucidated a novel mechanism containing lncRNA Gm47283/miR-706/Ptgs2/ferroptosis in MI, which provided a potential therapeutic for MI.

Graphical Abstract. Stem cell membrane coated siRNA of lncRNA Gm47283 inhibits cardiomyocyte ferroptosis in myocardial infarction rat. Stem cell membrane-coated siRNA of lncRNA Gm47283 increases miR-706, and then miR-706 suppresses the expression of Ptgs2 to reduce lipid peroxidation toxicity, and then inhibits cardiomyocyte ferroptosis. PUFA: polyunsaturated fatty acid.

Diagnosis and staging of HCV associated fibrosis, cirrhosis and hepatocellular carcinoma with target identification for miR-650, 552-3p, 676-3p, 512-5p and 147b

BACKGROUND: Chronic HCV infection progresses to fibrosis, cirrhosis and hepatocellular carcinoma (HCC). The latter represents the third most common cause for cancer mortality. Currently, there is no reliable non-invasive biomarker for diagnosis of HCV mediated disorders. OBJECTIVE: Profiling expression signature for circulatory miRNAs in the plasma of 167 Egyptian patients (40 healthy, 48 HCV fibrotic, 39 HCV cirrhotic and 40 HCV-HCC cases). METHODS: QRTPCR was used to quantify expression signature for circulatory miRNAs. RESULTS: MiR-676 and miR-650 were powerful in discriminating cirrhotic and late fibrosis from HCC. MiR-650 could distinguish mild (f0-f1) and advanced (f2-f3) fibrosis from HCC cases. MiR-650 and miR-147b could distinguish early fibrosis from healthy controls meanwhile miR-676 and miR-147b could effectively distinguish between mild chronic and (f1-f3) cases from healthy individuals. All studied miRNAs, except miR-512, can differentiate between (f0-f3) cases and healthy controls. Multivariate logistic regression revealed three potential miRNA panels for effective differentiation of HCC, cirrhotic and chronic liver cases. MiR-676-3p and miR-512-5p were significantly correlated in (f1-f3) fibrosis meanwhile miR-676 and miR-512 could differentiate between cirrhosis and (f0-f3) cases. Both miR-650 and miR-512-5p were positively correlated in the cirrhotic group and in (f0-f4) group. Putative targets for investigated miRNAs were also determined. CONCLUSIONS: Investigated miRNAs could assist in staging and diagnosis of HCV associated disorders.

Peroxisome proliferator-activated receptor gamma coactivator 1-alpha protects a fibrotic liver from partial hepatectomy-induced advanced liver injury through regulating cell cycle arrest

Background

A fibrotic liver may have an impaired regenerative capacity. Because liver transplantation is donor limited, understanding the regenerative ability of a fibrotic liver is important.

Methods

A two‐thirds partial hepatectomy (PH) was performed in C57Bl/6 mice with or without carbon tetrachloride (CCl₄) treatment. Liver regeneration in the fibrotic liver after PH was assessed by the intrahepatic expression of the cell cycle regulators p53, p21, cyclin D1, c‐Fos and CDK2 using Western blot analysis. In addition, the expression of PGC‐1α and the cell proliferation‐related proteins PCNA and phosphate histone H3 was determined by Western blot and immunohistochemical staining analyses. Histone epigenetic modification of the PGC‐1α promoter was investigated through chromatin immunoprecipitation (ChIP) and reverse transcription–quantitative polymerase chain reaction (RT‐qPCR) assays. The impact of PGC‐1α on liver regeneration after PH was further evaluated in PGC‐1α‐knockout mice.

Results

A decreased expression of PGC‐1α and liver regeneration‐related genes in the fibrotic liver was detected after a PH. Histone acetylation at the PGC‐1α promoter led to increases in PGC‐1α expression and the survival rate in the fibrotic group after a PH. PGC‐1α‐mediated liver regeneration was further demonstrated in PGC‐1α^f/falbcre^+/0 mice.

Conclusion

Targeting PGC‐1α may represent a strategy to improve the treatment of PH in patients with liver fibrosis.

Depletion of miR-155 hinders the myofibroblast activities and reactive oxygen species generation in oral submucous fibrosis

BACKGROUND/PURPOSE

Emerging evidence suggests the significance of microRNA-155 (miR-155) in fibrogenesis and oxidative stress accumulation, but its function in oral submucous fibrosis (OSF) has not been investigated. In this study, we assessed the expression of miR-155 and its effects on the maintenance of myofibroblast activation.

METHODS

qRT-PCR was conducted to assess the expression of miR-155 in OSF tissues and fibrotic buccal mucosal fibroblasts (fBMFs) derived from OSF samples. Collagen gel contraction, migration, and invasion capabilities were examined in fBMFs. DCFDA ROS assay was used to examine ROS generation. A luciferase reporter assay was carried out to verify the relationship between miR-155 and its potential target RPTOR.

RESULTS

We showed that the expression of miR-155 was aberrantly upregulated in OSF specimens and fBMFs. Inhibition of miR-155 ameliorated various myofibroblast activities, including collagen gel contraction, migration, and invasion abilities as well as ROS production. Results from the luciferase reporter assay demonstrated that miR-155 directly interacted with its target RPTOR.

CONCLUSION

Taken together, these findings indicate that miR-155 is implicated in the pathogenesis of oxidative stress-associated OSF, possibly through the regulation of RPTOR.

Circular RNAs: Novel Players in the Oxidative Stress-Mediated Pathologies, Biomarkers, and Therapeutic Targets

Oxidative stress (OxS) is a wildly described cause of damage to macromolecules, resulting in abnormal physiological conditions. In recent years, a few studies have shown that oxidation/antioxidation imbalance plays a significant role in developing diseases involving different systems and organs. However, the research on the circular RNA (circRNA) roles in OxS is still in its very infancy. Therefore, we hope to provide a comprehensive overview of the recent research that explored the function of circRNAs associated with OxS and its role in the pathogenesis of different diseases that affect different body systems like the nervous system, cardiovascular system, kidneys, and lungs. It provides the possibilities of using these circRNAs as superior diagnostic and therapeutic options for OxS associated with these disease conditions.

Role of circRNAs in viral infection and their significance for diagnosis and treatment (Review)

Circular RNAs (circRNAs) are a class of non-coding RNAs with a circular, covalent structure that lack both 5' ends and 3' poly(A) tails, which are stable and specific molecules that exist in eukaryotic cells and are highly conserved. The role of circRNAs in viral infections is being increasingly acknowledged, since circRNAs have been discovered to be involved in several viral infections (such as hepatitis B virus infection and human papilloma virus infection) through a range of circRNA/microRNA/mRNA regulatory axes. These findings have prompted investigations into the potential of circRNAs as targets for the diagnosis and treatment of viral infection-related diseases. The aim of the present review was to systematically examine and discuss the role of circRNAs in several common viral infections, as well as their potential as diagnostic markers and therapeutic targets.

MiR-706 alleviates white matter injury via downregulating PKCα/MST1/NF-κB pathway after subarachnoid hemorrhage in mice

Increasing numbers of patients with spontaneous subarachnoid hemorrhage(SAH) who recover from surgery and intensive care management still live with cognitive impairment after discharge, indicating the importance of white matter injury at the acute stage of SAH. In the present study, standard endovascular perforation was employed to establish an SAH mouse model, and a microRNA (miRNA) chip was used to analyze the changes in gene expression in white matter tissue after SAH. The data indicate that 17 miRNAs were downregulated, including miR-706, miR-669a-5p, miR-669p-5p, miR-7116-5p and miR-195a-3p, while 13 miRNAs were upregulated, including miR-6907-5p, miR-5135, miR-6982-5p, miR-668-5p, miR-8119. Strikingly, miR-706 was significantly downregulated with the highest fold change. Further experiments confirmed that miR-706 could alleviate white matter injury and improve neurological behavior, at least partially by inhibiting the PKCα/MST1/NF-κB pathway and the release of inflammatory cytokines. These results might provide a deeper understanding of the pathophysiological processes in white matter after SAH, as well as potential therapeutic strategies for the translational research.

Research Advances in the Molecular Functions and Relevant Diseases of TAOKs, Novel STE20 Kinase Family Members

As serine/threonine-protein kinases, Thousand and One Kinases(TAOKs) are members of the GCKlike superfamily, one of two well-known branches of the Ste20 kinase family. Within the last two decades, three functionally similar kinases, namely TAOK1-3, were identified. TAOKs are involved in many molecular and cellular events. Scholars widely believe that TAOKs act as kinases upstream of the MAPK cascade and as factors that interact with MST family kinases, the cytoskeleton, and apoptosis-associated proteins. Therefore, TAOKs are thought to function in tumorigenesis. Additionally, TAOKs participate in signal transduction induced by Notch, TCR, and IL-17. Recent studies found that TAOKs play roles in a series of diseases and conditions, such as the central nervous system dysfunction, herpes viral infection, immune system imbalance, urogenital system malformation during development, cardiovascular events, and childhood obesity. Therefore, inhibitory chemicals targeting TAOKs may be of great significance as potential drugs for these diseases.

Genome-wide expression analysis of a new class of lncRNAs driven by SINE B2

Repetitive short interspersed elements B2 (SINE B2) have been shown to possess two promoters: polymerase III promoter for producing short B2-S RNAs and polymerase II promoter for driving the expression of long non-coding RNA (B2-AS lncRNAs). Using a B2-antisense (B2-AS) transcript sequence from the SINE B2 resident in mitochondrial translocator protein gene (Tspo) locus, we constructed a B2-AS specific RNA library and identified 96,862 sequences encoding potential B2-mediated lncRNAs, of which 55,592 lncRNAs with more than 390 nt in length possess a feature of potential genomic locus-specific effect. In addition, small RNA-Northern hybridization showed that the new B2-AS lncRNAs are constantly degraded by the Dicer1 enzyme, a finding further confirmed by in vitro Dicer1 enzyme digestion. B2-AS lncRNAs regulate the expression of target genes in a different fashion than B2-S RNAs. Genome-wide cross-comparison with mRNA mapping showed a total of 904 mRNA loci directly targeted by B2-AS lncRNAs, suggesting a locus-specific effect of the B2-AS lncRNAs and a general effect of B2-S RNAs.

The Diverse Roles of TAO Kinases in Health and Diseases

Thousand and one kinases (TAOKs) are members of the MAP kinase kinase kinase (MAP3K) family. Three members of this subfamily, TAOK1, 2, and 3, have been identified in mammals. It has been shown that TAOK1, 2 and 3 regulate the p38 MAPK and Hippo signaling pathways, while TAOK 1 and 2 modulate the SAPK/JNK cascade. Furthermore, TAOKs are involved in additional interactions with other cellular proteins and all of these pathways modulate vital physiological and pathophysiological responses in cells and tissues. Dysregulation of TAOK-related pathways is implicated in the development of diseases including inflammatory and immune disorders, cancer and drug resistance, and autism and Alzheimer's diseases. This review collates current knowledge concerning the roles of TAOKs in protein-protein interaction, signal transduction, physiological regulation, and pathogenesis and summarizes the recent development of TAOK-specific inhibitors that have the potential to ameliorate TAOKs' effects in pathological situations.

Thousand and one kinase 1 protects MCAO-induced cerebral ischemic stroke in rats by decreasing apoptosis and pro-inflammatory factors

Background: Birth hypoxia causes neonatal mortality and morbidity. Hypoxia/ischemia can facilitate brain damage, causing various kinds of diseases, such as ischemic stroke. It is necessary to understand the potential underlying mechanisms of ischemic stroke. Previous studies revealed the involvement of thousand and one kinase 1 (TAOK1) in many cellular processes. Methods: Herein, middle cerebral artery (MCA) occlusion (MCAO) was performed in rats to establish ischemic stroke in the animal model, and cortical neural stem cells from rats were treated with oxygen-glucose deprivation (OGD) to induce ischemic stroke cell model. The animal model of ischemic stroke was validated by Bederson and Zea-Longa neurological deficit scores and rotarod test. TAOK1 expression was examined by quantitative real-time PCR (qRT-PCR), Western blot, and immunofluorescent staining both in vivo and in vitro. Result: Compared with sham animals, the MCAO rats showed a significant increase in the neurological scores, and obvious motor behavioral deficits. Meanwhile, there was increased apoptosis and inflammatory response in the model group. TAOK1 overexpression reversed the OGD-induced cell injury, while TAOK1 knockdown exhibited the opposing effects. On the mechanism, the OGD-induced suppression of PI3K/AKT, and activation of mitogen-activated protein kinase (MAPK) signaling pathways were abolished by TAOK1 overexpression, and aggravated by TAOK1 knockdown in vitro. Moreover, we proved that the inhibitory effect of TAOK1 on OGD-induced apoptosis was dependent on the intracellular kinase activity. Conclusion: TAOK1 protected MCAO-induced cerebral ischemic stroke by decreasing the pro-inflammatory factors and apoptosis via PI3K/AKT and MAPK signaling pathways.

Inhalation of Stachybotrys chartarum Fragments Induces Pulmonary Arterial Remodeling

Stachybotrys chartarum is a fungal contaminant within the built environment and a respiratory health concern in the United States. The objective of this study was to characterize the mechanisms influencing pulmonary immune responses to repeatedly inhaled S. chartarum. Groups of B6C3F1/N mice repeatedly inhaled viable trichothecene-producing S. chartarum conidia (strain A or strain B), heat-inactivated conidia, or high-efficiency particulate absolute-filtered air twice per week for 4 and 13 weeks. Strain A was found to produce higher amounts of respirable fragments than strain B. Lung tissue, serum, and BAL fluid were collected at 24 and 48 hours after final exposure and processed for histology, flow cytometry, and RNA and proteomic analyses. At 4 weeks after exposure, a T-helper cell type 2-mediated response was observed. After 13 weeks, a mixed T-cell response was observed after exposure to strain A compared with a T-helper cell type 2-mediated response after strain B exposure. After exposure, both strains induced pulmonary arterial remodeling at 13 weeks; however, strain A-exposed mice progressed more quickly than strain B-exposed mice. BAL fluid was composed primarily of eosinophils, neutrophils, and macrophages. Both the immune response and the observed pulmonary arterial remodeling were supported by specific cellular, molecular, and proteomic profiles. The immunopathological responses occurred earlier in mice exposed to high fragment-producing strain A. The rather striking induction of pulmonary remodeling by S. chartarum appears to be related to the presence of fungal fragments during exposure.

Endoplasmic Reticulum Stress Induces miR-706, A Pro-Cell Death microRNA, in A Protein Kinase RNA-Like ER Kinase (PERK) and Activating Transcription Factor 4 (ATF4) Dependent Manner

Objective

Endoplasmic reticulum (ER) stress causes an adaptive response initiated by protein kinase RNA-like ER kinase (PERK), Ire1 and ATF6. It has been reported that these upstream regulators induce microRNAs. The current study was designed to find a novel microRNA that mediates ER stress components and finally contributes to cell fate decision.

Materials and Methods

In this experimental study, miR-706 levels were checked under different conditions of ER stress induced by Thapsigargin, Tunicamycin or low glucose media. PERK and ATF4 were knocked-down by administration of lentivirus-mediated short hairpin RNA to explore the effect of ER stress related proteins on miR-706 expression. The effect of miR-706 on caspase activity and apoptosis inhibitor 1 (CAAP1) levels were examined by using mimic-miR-706. The role of CAAP1 in inhibiting cell death (measured by Annexin V staining) and contributing to patient overall survival (measured by Kaplan-Meier estimate) were further confirmed by anti- miR-706 and CAAP1 knock-down.

Results

We showed that Thapsigargin or Tunicamycin triggered ER stress leading to the induction of miR-706. miR-706 induction is dependent on PERK and its downstream regulator ATF4, as knocking-down of PERK and ATF4 suppressed miR-706 induction in response to ER stress. Knocking-down of miR-706 reduces cell death triggered by ER stress, indicating that miR-706 is pro-cell death microRNA. We further identified CAAP1 as a miR-706 target in regulating ER stress initiated cell death.

Conclusion

Collectively, our results pointed to an ER signaling network consisting of proteins, microRNA and novel target.

Circular RNA 4099 aggravates hydrogen peroxide-induced injury by down-regulating microRNA-706 in L02 cells

AIMS

Hepatitis is a kind of liver dysfunction and usually refers to a variety of pathogenic factors. Circular RNA (circRNA) participates in diverse diseases. This study aimed to explore the roles and regulatory mechanisms of the circRNA-4099 in L02 cell line.

MAIN METHODS

Cells were induced with H₂O₂ dilutions and transfected with circRNA-4099 overproduction vectoer and the specific siRNA (si-circRNA-4099), as well as microRNA-706 (miR-706) mimic or the corresponding controls. Cell viability was detected with the CCK-8. The apoptotic rate was determined by the annexin v-FITC/PI with flow cytometer. The expression of circRNA-4099 or miR-706 was quantified depending on qRT-PCR. The reactive oxygen species (ROS) level was examined through ROS assay. The relative proteins were individually determined via western blot. The relationship between the circRNA-4099 and miR-706 was detected through bioinformatics analysis and luciferase reporter assay.

KEY FINDINGS

H₂O₂ induced inhibition of viability and promotion of apoptosis, ROS production and cell fibrosis as well as keap1/Nrf2 and p38MAPK cascades on L02 cell line. circRNA-4099 was stimulated by H₂O₂. Plentiful circRNA-4099 augmented H₂O₂-resulted damage by inhibiting miR-706. miR-706 mimic partly abolished the influence of circRNA-4099 on L02 cells. Meanwhile, circRNA-4099 silence exerted opposite effect on these elements above.

SIGNIFICANCE

circRNA-4099 aggravated H₂O₂-induced injury by inhibiting miR-706 through triggering keap1/Nrf2 and p38MAPK in the L02 cells.

Dicer1 facilitates liver regeneration in a manner dependent on the inhibitory effect of miR-21 on Pten and Rhob expression

AIMS

Tamoxifen-induced liver-specific Dicer1 deletion (iDicer1^-/-) in mature mice may provide clues demonstrating the genuine effects of acute loss of Dicer1 and miRNAs in the liver regeneration process.

MAIN METHODS

In this study, mice with tamoxifen-induced Dicer1 deletion through the Cre/LoxP system were constructed and then underwent classic 70% partial hepatectomy or CCl4-induced liver injury. To rescue the inhibitory effect of Dicer1 ablation on liver regeneration, miR-21 agomir was injected into the tail vein of iDicer1^-/- mice.

KEY FINDINGS

Unlike constitutive embryonic deletion of Dicer1, tamoxifen-induced Dicer1 deletion did not result in severe liver injury or lesions, providing an ideal model for investigating acute loss of Dicer1 and miRNAs in liver regeneration. Dicer1 deletion led to impaired liver regeneration through the inhibitory effect of miR-21 on PTEN and Rhob expression.

SIGNIFICANCE

In our previous study, we found that embryonic loss of Dicer1 impairs hepatocyte survival and leads to chronic inflammation and progenitor cell activation, while the role of Dicer1 in liver regeneration remains largely unknown. We clearly identified the promotion effect of Dicer1 on liver regeneration by increasing miR-21 expression, which inhibits the expression of two negative cell proliferation regulators, Pten and Rhob.

MiR-146a attenuates liver fibrosis by inhibiting transforming growth factor-β1 mediated epithelial-mesenchymal transition in hepatocytes

Epithelial-mesenchymal transition (EMT) has emerged as a vital process in embryogenesis, carcinogenesis, and tissue fibrosis. Transforming growth factor-beta 1 (TGF-β1)-mediated signaling pathways play important roles in the EMT process. MicroRNA-146a (miR-146a) has been suggested as a significant regulatory molecule in fibrogenesis. Therefore, the present study aimed to evaluate the effect of miR-146a on the EMT of hepatocytes and to investigate the role of overexpressing miR-146a on rat hepatic fibrosis. The results showed that the miR-146a level decreased during the EMT process of L02 hepatocytes induced by TGF-β1 in vitro. Moreover, miR-146a overexpression led to significant reduction of EMT-related markers expression in hepatocytes. Subsequent experiments revealed that miR-146a attenuated the EMT process in hepatocytes by targeting small mothers against decapentaplegic (SMAD) 4. Meanwhile, restoration of SMAD4 expression rescued the inhibitory effect of miRNA-146a on EMT. Further in vivo studies revealed that intravenous injection of miR-146a-expressing adenovirus (Ad-miR-146a) successfully restored the miR-146a levels and mitigated fibrogenesis in the livers of CCl4-treated rats. More importantly, after Ad-miR-146a treatment, inhibition of both EMT traits and SMAD4 expression was observed. The results of the present study showed that miR-146a/SMAD4 is a key signaling cascade that inhibits hepatocyte EMT, and the introduction of miR-146a might present a promising therapeutic option for liver fibrosis.

A New Insight into the Roles of MiRNAs in Metabolic Syndrome

Metabolic syndrome (MetS), which includes several clinical components such as abdominal obesity, insulin resistance (IR), dyslipidemia, microalbuminuria, hypertension, proinflammatory state, and oxidative stress (OS), has become a global epidemic health issue contributing to a high risk of type 2 diabetes mellitus (T2DM). In recent years, microRNAs (miRNAs), used as noninvasive biomarkers for diagnosis and therapy, have aroused global interest in complex processes in health and diseases, including MetS and its components. MiRNAs can exist stably in serum, liver, skeletal muscle (SM), heart muscle, adipose tissue (AT), and βcells, because of their ability to escape the digestion of RNase. Here we first present an overall review on recent findings of the relationship between miRNAs and several main components of MetS, such as IR, obesity, diabetes, lipid metabolism, hypertension, hyperuricemia, and stress, to illustrate the targeting proteins or relevant pathways that are involved in the progress of MetS and also help us find promising novel diagnostic and therapeutic strategies.

Redox Regulation and Noncoding RNAs

SIGNIFICANCE

RNA is a heterogeneous class of molecules with the minority being protein coding. Noncoding RNAs (ncRNAs) are involved in translation and epigenetic control mechanisms of gene expression. Recent Advances: In recent years, the number of identified ncRNAs has dramatically increased and it is now clear that ncRNAs provide a complex layer of differential gene expression control.

CRITICAL ISSUES

NcRNAs exhibit interplay with redox regulation. Redox regulation alters the expression of ncRNAs; conversely, ncRNAs alter the expression of generator and effector systems of redox regulation in a complex manner, which will be the focus of this review article.

FUTURE DIRECTIONS

Understanding the role of ncRNA in redox control will lead to the development of new strategies to alter redox programs. Given that many ncRNAs (particularly microRNAs [miRNAs]) change large gene sets, these molecules are attractive drug candidates; already, now miRNAs can be targeted in patients. Therefore, the development of ncRNA therapies focusing on these molecules is an attractive future strategy. Antioxid. Redox Signal. 29, 793-812.

Long non-coding RNA Gm2199 rescues liver injury and promotes hepatocyte proliferation through the upregulation of ERK1/2

Long non-coding RNAs (lncRNAs) are a new class of regulators of various human diseases. This study was designed to explore the potential role of lncRNAs in experimental hepatic damage. In vivo hepatic damage in mice and in vitro hepatocyte damage in AML12 and NCTC1469 cells were induced by carbon tetrachloride (CCl₄) treatments. Expression profiles of lncRNAs and mRNAs were analyzed by microarray. Bioinformatics analyses were conducted to predict the potential functions of differentially expressed lncRNAs with respect to hepatic damage. Overexpression of lncRNA Gm2199 was achieved by transfection of the pEGFP-N1-Gm2199 plasmid in vitro and adeno-associated virus-Gm2199 in vivo. Cell proliferation and viability was detected by cell counting kit-8 and 5-ethynyl-2′-deoxyuridine assay. Protein and mRNA expressions of extracellular signal-regulated kinase-1/2 (ERK1/2) were detected by western blot and quantitative real-time reverse-transcription PCR (qRT-PCR). Microarray analysis identified 190 and 148 significantly differentially expressed lncRNAs and mRNAs, respectively. The analyses of lncRNA-mRNA co-expression and lncRNA-biological process networks unraveled potential roles of the differentially expressed lncRNAs including Gm2199 in the pathophysiological processes leading to hepatic damage. Gm2199 was downregulated in both damaged livers and hepatocyte lines. Overexpression of Gm2199 restored the reduced proliferation of damaged hepatocyte lines and increased the expression of ERK1/2. Overexpression of Gm2199 also promoted the proliferation and viability of normal hepatocyte lines and increased the level of p-ERK1/2. Overexpression of Gm2199 in vivo also protected mouse liver injury induced by CCl₄, evidenced by more proliferating hepatocytes, less serum alanine aminotransferase, less serum aspartate aminotransferase, and decreased hepatic hydroxyproline. The ability of Gm2199 to maintain hepatic proliferation capacity indicates it as a novel anti-liver damage lncRNA.

Formula derived Maillard reaction products in post-weaning intrauterine growth-restricted piglets induce developmental programming of hepatic oxidative stress independently of microRNA-21 and microRNA-155

We recently reported augmentation of lipid peroxidation products in the liver of intrauterine growth-restricted (IUGR) piglets fed a high load of Maillard reaction products (MRPs) during suckling period. The underlying mechanisms of MRPs effects remain unknown. Here, we studied the long-term impact of MRPs exposure on liver oxidative status of IUGR juvenile pigs. Livers of 54-day-old pigs suckled with formula containing either a high (HHF, n=8) or a low (LHF: n=8) load of MRPs were analyzed for protein carbonylation levels , activities and messenger RNA (mRNA) expression of glutathione (GSH) and main antioxidant regulators of redox homeostasis [Superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were measured. In addition, mRNA levels of miRNA-21 and miRNA-155 were measured. The liver of HHF group exhibited a high level of lipid peroxidation with significantly increased expression and activity of SOD. Further in liver of HHF group, CAT activity was decreased as compared with LHF group, though with comparable total protein carbonyl contents, GSH contents, and expression of GPx and microRNAs (miRNA-21 and miRNA-155). Our findings suggest that the potential mechanism of MRPs-mediated oxidative stress programming in liver of IUGR piglets may occur via impairment of antioxidant defenses.