LncRNA GAS5/miR-137 Is a Hypoxia-Responsive Axis Involved in Cardiac Arrest and Cardiopulmonary Cerebral Resuscitation

BackgroundCardiac arrest/cardiopulmonary resuscitation (CA/CPR) represents one of the devastating medical emergencies and is associated with high mortality and neuro-disability. Post-cardiac arrest syndrome (PCAS) is mechanistically ascribed to acute systemic ischemia/reperfusion(I/R) injury. The lncRNA/microRNA/mRNA networks have been found to play crucial roles in the pathogenesis of the hypoxia-responsive diseases. Nonetheless, the precise molecular mechanisms by which lncRNA/miRNA/mRNA axes are involved in the astrocyte–microglia crosstalk in CA/CPR have not been fully elucidated.MethodsWe collected and purified the exosomes from the blood of CA/CPR patients and supernatant of OGD/R-stimulated astrocytes. On the basis of microarray analysis, bioinformatic study, and luciferase activity determination, we speculated that lncRNA GAS5/miR-137 is implicated in the astrocyte–microglia crosstalk under the insult of systemic I/R injury. The regulation of lncRNA GAS5/miR-137 on INPP4B was examined by cellular transfection in OGD/R cell culture and by lateral ventricle injection with miR-137 agomir in CA/CPR mice model. Flow cytometry and immunofluorescence staining were performed to detect the microglial apoptosis, M1/M2 phenotype transformation, and neuroinflammation. Neurological scoring and behavior tests were conducted in CA/CPR group, with miR-137 agomir lateral-ventricle infusion and in their controls.ResultsIn all the micRNAs, miR-137 was among the top 10 micRNAs that experienced greatest changes, in both the blood of CA/CPR patients and supernatant of OGD/R-stimulated astrocytes. Bioinformatic analysis revealed that miR-137 was sponged by lncRNA GAS5, targeting INPP4B, and the result was confirmed by Luciferase activity assay. qRT-PCR and Western blotting showed that lncRNA GAS5 and INPP4B were over-expressed whereas miR-137 was downregulated in the blood of CA/CPR patients, OGD/R-stimulated astrocytes, and brain tissue of CA/CPR mice. Silencing lncRNA GAS5 suppressed INPP4B expression, but over-expression of miR-137 negatively modulated its expression. Western blotting exhibited that PI3K and Akt phosphorylation was increased when lncRNA GAS5 was silenced or miR-137 was over-expressed. However, PI3K and Akt phosphorylation was notably suppressed in the absence of miR-137, almost reversing their phosphorylation in the silencing lncRNA GAS5 group. Then we found that GAS5 siRNA or miR-137 mimic significantly increased cell viability and alleviated apoptosis after OGD/R injury. Furthermore, over-expression of miR-137 attenuated microglial apoptosis and neuroinflammation in CA/CPR mice model, exhibiting significantly better behavioral tests after CA/CPR.ConclusionLncRNA GAS5/miR-137 may be involved in the astrocyte–microglia communication that inhibits PI3K/Akt signaling activation via regulation of INPP4B during CA/CPR.

NEAT1 Enhances MPP+-Induced Pyroptosis In SH-SY5Y Cells Via Targeting Mir-5047/YAF2 Signaling

Parkinson’s disease (PD) is the second most frequent neurodegenerative disease. The aim of our study is to explore the role and regulatory mechanism of long non-coding RNA (lncRNA) NEAT1 in the MPP+-induced neuron pyroptosis. The levels of miR-5047 and YAF2 mRNA were determined through qRT-PCR. TUNEL staining was carried out to analyze neuronal apoptosis. Luciferase activity assay was accomplished to analyze the combination of miR-5047 and NEAT1 and YAF2 3’-UTR. Besides, the concentrations of IL-1β and IL-18 in supernatant were analyzed by ELISA assay. The levels of protein were examined through Western blot. NEAT1 and YAF2 expression were increased, while miR-5047 level was declined in the SH-SY5Y cells treated with MPP+. NEAT1 was a positively regulator for the SH-SY5Y cells pyroptosis induced by MPP+. In addition, YAF2 was a downstream target of miR-5047. NEAT1 promoted YAF2 expression via inhibiting miR-5047. Importantly, the promotion of NEAT1 to SH-SY5Y cells pyroptosis induced by MPP+ was recused by miR-5047 mimic transfection and YAF2 downregulation. In conclusion, NEAT1 was increased in the SH-SY5Y cells treated with MPP+, and it promoted the MPP+-induced pyroptosis through facilitating YAF2 expression by sponging miR-5047.

Establishment of a stable SARS-CoV-2 replicon system for application in high-throughput screening.

Experiments with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are limited by the need for biosafety level 3 (BSL3) conditions. A SARS-CoV-2 replicon system rather than an in vitro infection system is suitable for antiviral screening since it can be handled under BSL2 conditions and does not produce infectious particles. However, the reported replicon systems are cumbersome because of the need for transient transfection in each assay. In this study, we constructed a bacterial artificial chromosome vector (the replicon-BAC vector) including the SARS-CoV-2 replicon and a fusion gene encoding Renilla luciferase and neomycin phosphotransferase II, examined the antiviral effects of several known compounds, and then established a cell line stably harboring the replicon-BAC vector. Several cell lines transiently transfected with the replicon-BAC vector produced subgenomic replicon RNAs (sgRNAs) and viral proteins, and exhibited luciferase activity. In the transient replicon system, treatment with remdesivir or interferon-β but not with camostat or favipiravir suppressed the production of viral agents and luciferase, indicating that luciferase activity corresponds to viral replication. VeroE6/Rep3, a stable replicon cell line based on VeroE6 cells, was successfully established and continuously produced viral proteins, sgRNAs and luciferase, and their production was suppressed by treatment with remdesivir or interferon-β. Molnupiravir, a novel coronavirus RdRp inhibitor, inhibited viral replication more potently in VeroE6/Rep3 cells than in VeroE6-based transient replicon cells. In summary, our stable replicon system will be a powerful tool for the identification of SARS-CoV-2 antivirals through high-throughput screening.

Ependymoma associated protein Zfta is expressed in immature ependymal cells but is not essential for ependymal development in mice

The fusion protein of uncharacterised zinc finger translocation associated (ZFTA) and effector transcription factor of tumorigenic NF-kB signalling, RELA (ZFTA-RELA), is expressed in more than two-thirds of supratentorial ependymoma (ST-EPN-RELA), but ZFTA’s expression profile and functional analysis in multiciliated ependymal (E1) cells have not been examined. Here, we showed the mRNA expression of mouse Zfta peaks on embryonic day (E) 17.5 in the wholemount of the lateral walls of the lateral ventricle. Zfta was expressed in the nuclei of FoxJ1-positive immature E1 (pre-E1) cells in E18.5 mouse embryonic brain. Interestingly, the transcription factors promoting ciliogenesis (ciliary TFs) (e.g., multicilin) and ZFTA-RELA upregulated luciferase activity using a 5’ upstream sequence of ZFTA in cultured cells. Zftatm1/tm1 knock-in mice did not show developmental defects or abnormal fertility. In the Zftatm1/tm1 E1 cells, morphology, gene expression, ciliary beating frequency and ependymal flow were unaffected. These results suggest that Zfta is expressed in pre-E1 cells, possibly under the control of ciliary TFs, but is not essential for ependymal development or flow. This study sheds light on the mechanism of the ZFTA-RELA expression in the pathogenesis of ST-EPN-RELA: Ciliary TFs initiate ZFTA-RELA expression in pre-E1 cells, and ZFTA-RELA enhances its own expression using positive feedback.

MiR-486-3p and MiR-938—Important Inhibitors of Pacemaking Ion Channels and/or Markers of Immune Cells

The sinus node (SN) is the heart’s primary pacemaker and has a unique expression of pacemaking ion channels and immune cell markers. The role of microribonucleic acids (miRNAs) in control of ion channels and immune function of the sinus node is not well understood. We have recently shown that hsa-miR-486-3p downregulates the main pacemaking channel HCN4 in the SN. In addition, we recently demonstrated that immune cells are significantly more abundant in the SN compared to the right atrium. The aim of this study was to validate the previously predicted interactions between miRNAs and mRNAs of key Ca2+ ion channels (involved in peacemaking) and mRNA of TPSAB1—(a mast cells marker) using luciferase assay. We now show that miR-486 significantly downregulates Cav1.3, Cav3.1, and TPSAB1-mediated luciferase activity, while miR-938 significantly downregulates only TPSAB1-mediated luciferase activity. This makes miR-486-3p a potential therapeutic target in the treatment of SN dysfunctions.

Down-Regulated hsa-miR-190b-5p is Correlated With BCL11A Expression in Pediatric β-Thalassemia

Background: Transcription factor BCL11A is a key regulator of hemoglobin switching in adult β-thalassemia. Several microRNAs (miRNAs) involve in the pathology of β-thalassemia by regulations of BCL11A. However, the expressions and regulators of BCL11A in pediatric β-thalassemia were unclear. Methods: 18 pediatric β- thalassemia patients and 11 healthy controls were selected in this study. We applied reverse transcript quantitative real time PCR (RT-PCR) to analyze the expression levels of hsa-miR-190b-5p and γ-globin in pediatric β-thalassemia patients and luciferase activity assay to find out the direct regulations of BCL11A . Correlation between hsa-miR-190b-5p and biochemical indicators, BCL11A was assessed by the Pearson’s correlation test. Results: The expression levels of γ-globin in pediatric β-thalassemia patients were significantly increased. Moreover, the expression levels of hsa-miR-190b-5p were significantly down-regulated in pediatric β-thalassemia patients. Furthermore, hsa-miR-190b-5p was negatively correlated with BCL11A expression in pediatric β-thalassemia patients. Through luciferase activity assay, we found that hsa-miR-190b-5p was directly interacted with BCL11A 3’UTR 499-506 regions. Conclusion: Our results suggested that hsa-miR-190b-5p played key roles in regulating of BCL11A expression, which might provide novel therapies in pediatric patients with β-thalassemia .

Midgut-Specific Expression of P450 Gene Increases Deltamethrin Tolerance in The Fall Armyworm, Spodoptera Frugiperda

The piggyBac-based germline transformation system was recently established in a global agricultural pest, the fall armyworm (FAW), Spodoptera frugiperda. Tissue-specific promoters are needed to apply this transformation system to express transgenes in a tissue-specific manner. Highly expressed genes in the midgut were identified by RNA sequencing and RT-qPCR. Promoter regions of 11 genes highly expressed in the midgut were identified and cloned. Baculoviruses expressing the luciferase under the control of these promoters were produced and tested in the FAW. These baculoviruses did not show significant luciferase activity in the FAW midgut. Four transgenic FAW lines, expressing the luciferase under the control of SfSP38/P2000, SfCalphotin/P2000, SfMG17/P2000, and SfCPH38/P2000 promoters were generated using piggyBac-based germline transformation methods. Significantly higher luciferase activity was detected in the midgut than in other tissues of transgenic FAW. SfCPH38/P2000 promoter with the highest activity and midgut-specificity was used to drive the expression of a P450, SfCYP321A8 known to be involved in deltamethrin resistance. Higher mRNA levels of SfCYP321A8 and P450 activity were detected in the midgut of transgenic larvae than in wild-type larvae. Bioassays showed that the transgenic larvae expressing SfCYP321A8 in the midgut are tolerant to deltamethrin. Here, we presented methods for the identification of midgut-specific promoters in the FAW and used them to study the role of P450 overexpression in the midgut on insecticide resistance. These methods could also be used to identify other tissue-specific promoters for applications of piggyBac-based germline transformation in functional genomics in FAW and other non-model insects.

Development of CIDEA reporter mouse model and its application for screening thermogenic drugs

Cell death-inducing DNA fragmentation factor-like effector A (CIDEA) is a lipid droplet-associated protein and is a known marker of the thermogenic capacity of brown/beige adipocytes. To monitor the expression of CIDEA in live mice in a non-invasive manner, we generated CIDEA reporter mice expressing multicistronic mRNAs encoding CIDEA, luciferase 2, and tdTomato proteins under the control of the Cidea promoter. The expression level of endogenous CIDEA protein in adipose tissue was not affected by the expression of polycistronic reporters. The two CIDEA reporters, luciferase 2 and tdTomato, correctly reflected CIDEA protein levels. Importantly, luciferase activity was induced by cold exposure and the treatment with β3-adrenergic receptor agonist CL316,243 in interscapular and inguinal adipose tissue, which was detectable by in vivo bioluminescence imaging. We further evaluated the effects of candidate brown adipogenic agents using this CIDEA reporter system and demonstrated a positive correlation between drug-induced luciferase activity and thermogenic gene expression levels both in vitro and in vivo. Collectively, we established a dual CIDEA reporter mouse model in which fluorescence and luminescence signals correctly reflect CIDEA expression, and therefore, suggested that this reporter system can be used to evaluate the thermogenic efficacy of candidate molecules.

MicroRNA-497 induced by Clonorchis sinensis enhances the TGF-β/Smad signaling pathway to promote hepatic fibrosis by targeting Smad7

Background Various stimuli, including Clonorchis sinensis infection, can cause liver fibrosis. Liver fibrosis is characterized by the activation of hepatic stellate cells (HSCs) with massive production of extracellular matrix (ECM). Our previous study showed that the TGF-β1-induced Smad signaling pathway played a critical role in the activation of HSCs during liver fibrosis induced by worm infection; however, the mechanisms that modulate the TGF-β/Smad signaling pathway are still poorly understood. Accumulating evidence demonstrates that miRNAs act as an important regulator of activation of HSCs during liver fibrosis. Methods The target of miR-497 was determined by bioinformatics analysis combined with a dual-luciferase activity assay. LX-2 cells were transfected with miR-497 inhibitor and then stimulated with TGF-β1 or excretory/secretory products of C. sinensis (CsESPs), and activation of LX-2 was assessed using qPCR or western blot. In vivo, the mice treated with CCl4 were intravenously injected with a single dose of adeno-associated virus serotype 8 (AAV8) that overexpressed anti-miR-497 sequences or their scramble control for 6 weeks. Liver fibrosis and damage were assessed by hematoxylin and eosin (H&E) staining, Masson staining, and qPCR; the activation of the TGF-β/Smad signaling pathway was detected by qPCR or western blot. Results In the present study, the expression of miR-497 was increased in HSCs activated by TGF-β1 or ESPs of C. sinensis. We identified that Smad7 was the target of miR-497 using combined bioinformatics analysis with luciferase activity assays. Transfection of anti-miR-497 into HSCs upregulated the expression of Smad7, leading to a decrease in the level of p-Smad2/3 and subsequent suppression of the activation of HSCs induced by TGF-β1 or CsESPs. Furthermore, miR-497 inhibitor delivered by highly-hepatotropic (rAAV8) inhibited TGF-β/smads signaling pathway by targeting at Smad7 to ameliorate CCL4-induced liver fibrosis. Conclusions The present study demonstrates that miR-497 promotes liver fibrogenesis by targeting Smad7 to promote TGF-β/Smad signaling pathway transduction both in vivo and in vitro, which provides a promising therapeutic strategy using anti-miR-497 against liver fibrosis. Graphical Abstract

Triptolide Downregulates the Expression of NRF2 Target Genes by Increasing Cytoplasmic Localization of NRF2 in A549 Cells

We have identified triptolide as a novel NRF2 inhibitor, which significantly attenuates ARE-luciferase activity at nanomolar concentrations. Triptolide did not affect the level of NRF2, but significantly inhibited the expression of NRF2 target genes in A549 cells. We found that NRF2 possesses a previously unrecognized NES in the Neh2 domain, and that triptolide promotes an interaction between NRF2 and CRM1. Triptolide also decreased nuclear accumulation of NRF2, suggesting that it promotes nuclear export of NRF2. In addition, we show that triptolide decreased the expression of NRF2 target genes and increased intracellular oxidative stress, suppressing invasion and promoting cisplatin-induced apoptosis in A549 cells. Finally, oral administration of triptolide suppressed the growth of A549 xenografts in athymic mice by decreasing the expression of NRF2 target genes and promoting oxidative damages via the nuclear export of NRF2 and CRM1 in vivo. To the best of our knowledge, triptolide is the first type of compound to inhibit NRF2 by increasing cytoplasmic localization of NRF2.