Activating Mitochondrial Sirtuin 3 in Chondrocytes Alleviates Aging-Induced Fibrocartilage Layer Degeneration and Promotes Healing of Degenerative Rotator Cuff Injury.

The present study aimed to examine the impact of mitochondrial sirtuin 3 (SIRT3) on the degenerative rotator cuff injury, which is a prevalent issue among the elderly population primarily due to aging-related tissue degradation. The study hypothesized that SIRT3, as a major deacetylase in mitochondria, is a significant factor in controlling the quality of mitochondria and the deterioration of fibrocartilage, a crucial component of the rotator cuff. Results showed that the aging process led to weakened biomechanical properties and degeneration of the fibrocartilage layer in mice, accompanied by a decrease in SIRT3 expression. SIRT3 activation ameliorated the aging-related disruption of chondrocyte phenotype and fibrocartilage degradation. SIRT3 activator honokiol improved the phenotype of senescent chondrocytes and promoted rotator cuff healing in aged mice through SIRT3 activation. In conclusion, the findings suggested that the decline in SIRT3 levels with age contributes to rotator cuff degeneration and chondrocyte senescence, and that SIRT3 activation through the use of honokiol is an effective approach for promoting rotator cuff healing in the elderly population.

Cobalt-Catalyzed Borylative Reduction of Azobenzenes to Hydrazobenzenes via a Diborylated-Hydrazine Intermediate.

Cobalt-catalyzed borylative reduction of azobenzenes using pinacolborane is developed. The simple cobalt chloride catalyst and reaction conditions make this protocol attractive for hydrazobenzene synthesis. This borylative reduction shows good functional group compatibility and can be readily scaled up to the gram scale. Preliminary mechanistic studies clarified the proton source of the hydrazine products. This cobalt-catalyzed azobenzene borylative reaction provides a practical protocol to prepare synthetically useful diborylated hydrazines.

Co-dependent regulation of p-BRAF and potassium channel KCNMA1 levels drives glioma progression.

BRAF mutations have been found in gliomas which exhibit abnormal electrophysiological activities, implying their potential links with the ion channel functions. In this study, we identified the Drosophila potassium channel, Slowpoke (Slo), the ortholog of human KCNMA1, as a critical factor involved in dRafGOF glioma progression. Slo was upregulated in dRafGOF glioma. Knockdown of slo led to decreases in dRafGOF levels, glioma cell proliferation, and tumor-related phenotypes. Overexpression of slo in glial cells elevated dRaf expression and promoted cell proliferation. Similar mutual regulations of p-BRAF and KCNMA1 levels were then recapitulated in human glioma cells with the BRAF mutation. Elevated p-BRAF and KCNMA1 were also observed in HEK293T cells upon the treatment of 20 mM KCl, which causes membrane depolarization. Knockdown KCNMA1 in these cells led to a further decrease in cell viability. Based on these results, we conclude that the levels of p-BRAF and KCNMA1 are co-dependent and mutually regulated. We propose that, in depolarized glioma cells with BRAF mutations, high KCNMA1 levels act to repolarize membrane potential and facilitate cell growth. Our study provides a new strategy to antagonize the progression of gliomas as induced by BRAF mutations.

A novel member of miR169 family negatively regulates maize resistance against Bipolaris maydis.

MicroRNAs (miRNAs) have been confirmed to play important roles in plant defense response. However, the key maize miRNAs involved in the defense response against Bipolaris maydis are very limited. In this study, a novel member of the miR169 family in response to B. maydis, named zma-miR169s, was discovered and investigated. The expression levels of pre-miR169s and zma-miR169s were significantly repressed during B. maydis infection. CRISPR/Cas9-induced zma-miR169s mutant exhibited more resistance against B. maydis, whereas overexpression zma-miR169s enhanced susceptibility, supporting that zma-miR169s might play a negative role in maize resistance. Moreover, RNA-seq and GO analysis showed that differentially expressed genes were highly enriched in the oxidation-reduction process and plant hormone pathway. Hence, reactive oxygen species (ROS) and plant hormone levels were further investigated. ROS detection confirmed that zma-miR169s mutant accumulated more ROS, while less ROS was detected in transgenic maize OE-miR169s. Furthermore, more remarkable changes in PR-1 expression levels and salicylic acid (SA) contents were detected in zma-miR169s mutant compared to wild-type and transgenic maize during B. maydis infection. Additionally, nuclear transcription factors (NF-YA1 and NF-YA13) were identified as targets regulated by zma-miR169s through the agrobacterium-mediated transient expression method. Overexpression of ZmNF-YA13 enhanced Arabidopsis resistance to Pseudomonas syringae pv. tomato DC3000. Taken together, our results suggest that zma-miR169s negatively regulate maize defense responses by influencing ROS accumulation and the SA-dependent signaling pathway.

Experience of diet in patients with inflammatory bowel disease: A thematic synthesis of qualitative studies.

AIM: To synthesise the dietary expesriences of patients with inflammatory bowel disease by reviewing relevant qualitative studies. BACKGROUND: Diet plays a crucial role in the development and progression of inflammatory bowel disease (IBD). There is no specific diet that can be recommended for all patients. We conducted a synthesis of qualitative studies to gain a comprehensive understanding of the dietary management experience of patients with IBD, aiming to provide better dietary guidance in the future. DESIGN: A qualitative synthesis was conducted following the Thomas and Harden method and reported following the ENTREQ statement. METHODS: Qualitative studies were systematically searched in five electronic databases: PubMed, PsycINFO, Embase, CINAHL, and Web of Science. There was no time limit for publication, and all database searches were up to 10 May, 2023. The Joanna Briggs Institute Qualitative Assessment and Review Instrument was utilised to appraise the quality of the included studies. Data for inclusion in articles were extracted and analysed using a thematic synthesis method. RESULTS: Six studies involving 119 patients were eventually included. The studies were conducted in six different countries. Four major themes were identified: the diet of patients with IBD is completely different from the normal one; manage symptoms and live with the disease by modifying diet; psychological adjustment to eating (be frustrated; worried and afraid; feel ashamed; growth and resilience); barriers and challenges (barriers from perceived social support; conflicts between diet and nutrition; challenges from food hedonism and cravings). CONCLUSIONS: Patients with IBD highlighted the distinction between their diet and the normal diet. Dietary modifications were used as a way to manage symptoms and live with the disease. In addition to physical symptoms, patients experienced diet-related psychological changes. Dietary modifications in patients with IBD encounters difficulties and challenges, necessitating prompt guidance and intervention. (1) The implementation of dietary modifications in patients with IBD encounters numerous obstacles and complexities, necessitating prompt guidance and intervention. PATIENT OR PUBLIC CONTRIBUTION: No patient or public contribution. REGISTRATION: The protocol was registered with PROSPERO (CRD42023391545).

Endothelial progenitor cell-derived exosomes promote anti-inflammatory macrophages via SOCS3/JAK2/STAT3 axis and improve the outcome of spinal cord injury.

BACKGROUND: Macrophage in the spinal cord injury (SCI) area imparts a chronic pro-inflammation effect that challenges the recovery of SCI. Previously, endothelial progenitor cell-produced exosomes (EPC-EXOs) have been noticed to facilitate revascularization and inflammation control after SCI. However, their effects on macrophage polarization remained unclear. This study aimed to investigate the EPC-EXOs' role in macrophage polarization and reveal its underlying mechanism. METHODS: We extracted the macrophages and EPC from the bone marrow suspension of C57BL/L mice by centrifugation. After cell identification, the EPC-EXOs were collected by ultra-high-speed centrifugation and exosome extraction kits and identified by transmission electron microscopy and nanoparticle tracking analysis. Then, macrophages were cultured with EPC-EXOs in different concentrations. We labeled the exosome to confirm its internalization by macrophage and detected the macrophage polarization marker level both in vitro and in vivo. We further estimated EPC-EXOs' protective effects on SCI by mice spinal cord tissue H&E staining and motor behavior evaluation. Finally, we performed RT-qPCR to identify the upregulated miRNA in EPC-EXOs and manipulate its expression to estimate its role in macrophage polarization, SOCS3/JAK2/STAT3 pathway activation, and motor behavior improvement. RESULTS: We found that EPC-EXOs decreased the macrophages' pro-inflammatory marker expression and increased their anti-inflammatory marker expression on the 7 and 14 days after SCI. The spinal cord H&E staining results showed that EPC-EXOs raised the tissue-sparing area rate significantly after 28 days of SCI and the motor behavior evaluation indicated an increased BMS score and motor-evoked potential by EPC-EXOs treatment after SCI. The RT-qPCR assay identified that miR-222-3P upregulated in EPC-EXOs and its miRNA-mimic also decreased the pro-inflammatory macrophages and increased the anti-inflammatory macrophages. Additionally, miR-222-3P mimic activated the SOCS3/JAK2/STAT3 pathway, and SOCS3/JAK2/STAT3 pathway inhibition blocked miR-2223P's effects on macrophage polarization and mouse motor behavior. CONCLUSION: Comprehensively, we discovered that EPC-EXOs-derived miR-222-3p affected macrophage polarization via SOCS3/JAK2/STAT3 pathway and promoted mouse functional repair after SCI, which reveals EPC-EXOs' role in modulation of macrophage phenotype and will provide a novel interventional strategy to induce post-SCI recovery.

PRDX6-mediated pulmonary artery endothelial cell ferroptosis contributes to monocrotaline-induced pulmonary hypertension.

BACKGROUND: Pulmonary hypertension (PH) is a life-threatening cardiopulmonary disorder whose underlying pathogenesis is unknown. Our previous study showed that pulmonary endothelial cell (PAEC) ferroptosis is involved in the progression of PH by releasing High-mobility group box 1 (HMGB1) and activating Toll-like receptor 4/NOD-like receptor family pyrin domain containing 3 (TLR4/NLRP3) inflammasome signalling. The precise mechanisms that regulate ferroptosis in PH are unclear. This study aimed to investigate the effect of peroxiredoxin 6 (PRDX6) on PAEC ferroptosis in PH. METHODS: A rat model of PH was established with monocrotaline (MCT), and the distribution and expression of PRDX6 in the pulmonary artery were examined. Lentiviral vectors carrying PRDX6 (LV-PRDX6) were transfected into PAECs and injected into MCT-induced PH rats. Cell viability, MDA levels, reactive oxygen species (ROS) levels, labile iron pool (LIP) levels and mitochondrial morphology were examined. Ferroptosis-related proteins (NADPH oxidase-4 (NOX4), glutathione peroxidase 4 (GPX4), and ferritin heavy chain 1(FTH1)), TLR4, NLRP3 inflammasome markers, HMGB1 and inflammatory cytokines were examined. Pulmonary vascular remodelling and right ventricular structure and function were measured. RESULTS: PRDX6 was expressed in PAECs and was significantly decreased in PH. PRDX6 overexpression significantly inhibited ferroptosis in PAECs under PH conditions in vitro and in vivo, as indicated by increased cell viability, decreased MDA, ROS and LIP levels, inhibited mitochondrial damage, upregulated GPX4 and FTH1 expression, and downregulated NOX4 expression. PRDX6 overexpression attenuated pulmonary vascular remodelling and changes in right ventricle structure and function in MCT-induced PH rats. Moreover, PRDX6 overexpression prevented HMGB1 release by PAECs and decreased TLR4 and NLRP3 inflammasome expression and inflammatory cytokine release in macrophages, while RSL3, a specific activator of ferroptosis, reversed these effects. CONCLUSIONS: Taken together, these findings indicate that PRDX6 regulates PAEC ferroptosis through the release of HMGB1 and activation of the TLR4/NLRP3 inflammasome signalling pathway, providing novel therapeutic targets for the treatment of PH.

Intravenous nicorandil for patients with acute decompensated heart failure: a meta-analysis of randomized controlled trials.

OBJECTIVES: Pilot studies have suggested the potential benefits of intravenous nicorandil for patients with acute decompensated heart failure (ADHF). However, clinical evidence remains limited. The aim of the study was to summarize the efficacy and safety of intravenous nicorandil for the treatment of ADHF. DESIGN: A systematic review and meta-analysis was performed. The search for relevant randomised controlled trials (RCTs) was conducted in PubMed, Embase, Cochrane's Library, Wanfang, and CNKI databases. A random-effects model was employed to combine the results. RESULTS: Eight RCTs contributed to the meta-analysis. Pooled results showed that acute treatment with intravenous nicorandil could significantly improve the symptom of dyspnea at 24 h after treatment, as evidenced by the five-point Likert scale for dyspnea after treatment (mean difference [MD]: -0.26, 95% confidence interval [CI]: -0.40 to -0.13, p < 0.001). Furthermore, nicorandil significantly reduced serum B natriuretic peptide (MD: -30.03 ng/dl, 95% CI: -47.00 to -13.06, p < 0.001), and N-terminal proBNP (MD: -138.69, 95% CI: -248.06 to -29.31, p = 0.01). In addition, nicorandil significantly improved ultrasonic parameters including left ventricular ejection fraction and E/e' at discharge. Moreover, during the follow-up duration of up to 90 days, intravenous nicorandil significantly reduced the incidence of major adverse cardiovascular events (risk ratio [RR]: 0.55, 95% CI: 0.32 to 0.93, p = 0.03). The incidence of treatment-related adverse events was not significantly different between nicorandil and controls (RR: 1.22, 95% CI: 0.69 to 2.15, p = 0.49). CONCLUSIONS: Results of this study suggest that intravenous nicorandil may be an effective and safe treatment for patients with ADHF.

Effects of Persimmon (Diospyros kaki L. cv. Mopan) Polysaccharide and Their Carboxymethylated Derivatives on Lactobacillus Strains Proliferation and Gut Microbiota: A Comparative Study.

Persimmon is a fruit that contains sugars, vitamins, phenolic compounds, and various other nutrients. The aim of this study was to explore the structure of carboxymethylated persimmon polysaccharide (CM-PFP) and its interaction with the human gut microbiota. Carboxymethyl modification of the persimmon polysaccharide (PFP) increased both the Mw and Mn, enhanced dispersion stability, and decreased thermal stability. Both PFP and CM-PFP promoted the proliferation of Lactobacillus while inhibiting the proliferation of Staphylococcus aureus and Escherichia coli. In the simulated fecal fermentation, the pH of PFP- and CM-PFP-containing media decreased, the content of short-chain fatty acids increased, and the abundance of intestinal flora at the phylum and genus levels changed. The relative abundance of harmful intestinal bacteria was significantly reduced in both PFP and CM-PFP groups. Furthermore, it was found that CM-PFP was more easily metabolized than PFP, glucose, and fructo-oligosaccharide (FOS) and had a proliferation increase effect on Lactobacillus. Therefore, CM-PFP has a significant positive effect on both Lactobacillus proliferation and the human gut microbiota.

Effect of Drying-Rewetting cycles on the metal adsorption and tolerance of natural biofilms.

Drying-rewetting (D-RW) cycles can induce changes in biofilms by forcing the microbial community to tolerate and adapt to environmental pressure. Existing studies have mostly focused on the impact of D-RW cycles on the microbial community structure, and little attention has been paid to how D-RW cycles may change the biofilm tolerance and adsorption of heavy metals. We experimentally evaluated the effect of repeated D-RW cycles on the Cd2+ and Pb2+ adsorption and tolerance of biofilms. The equilibrium adsorption capacity of the biofilm decreased as the number of D-RW cycles was increased, which was attributed to a change in affinity between the biofilm and metal ions. For a binary metal system, the D-RW cycles affected the competitive adsorption of Cd2+ and Pb2+ by the biofilm. A synergistic effect was observed with one and three D-RW cycles, while an antagonistic effect was observed for the control film and five D-RW cycles. The tolerance of the biofilm to Cd2+ and Pb2+ increased with the number of D-RW cycles. The stress from the D-RW cycles may have increased the relative abundance of drought-tolerant bacteria, which altered the biofilm functions and thus indirectly affected the heavy metal adsorption capacity.

Progress on RNA-based therapeutics for genetic diseases. / æ²»ç–—é—ä¼ ç— çš„RNAè¯ç‰©ç ”ç©¶è¿›å±•.

RNA therapeutics inhibit the expression of specific proteins/RNAs by targeting complementary sequences of corresponding genes or encode proteins for the synthesis desired genes to treat genetic diseases. RNA-based therapeutics are categorized as oligonucleotide drugs (antisense oligonucleotides, small interfering RNA, RNA aptamers), and mRNA drugs. The antisense oligonucleotides and small interfering RNA for treatment of genetic diseases have been approved by the FDA in the United States, while RNA aptamers and mRNA drugs are still in clinical trials. Chemical modifications can be applied to RNA drugs, such as pseudouridine modification of mRNA, to reduce immunogenicity and improve the efficacy. The secure and effective delivery systems such as lipid-based nanoparticles, extracellular vesicles, and virus-like particles are under development to address stability, specificity, and safety issues of RNA drugs. This article provides an overview of the specific molecular mechanisms of eleven RNA drugs currently used for treating genetic diseases, and discusses the research progress of chemical modifications and delivery systems of RNA drugs.

Maize Root Exudates Recruit Bacillus amyloliquefaciens OR2-30 to Inhibit Fusarium graminearum Infection.

Bacillus spp. can exert plant growth-promoting effects and biocontrol effects after effective colonization, and bacterial chemotaxis toward plant root exudates is the initial step to colonize. Under biotic stress, plants are able to alter their root exudates to attract or avoid different types of microbes. Hence, Bacillus chemotaxis toward root exudates after pathogen infection is crucial for exerting their beneficial effects. In this study, the Bacillus amyloliquefaciens OR2-30 strain, which exhibited greater chemotaxis ability toward maize root exudates after Fusarium graminearum infection, was screened from 156 rhizosphere microorganisms. The infected maize root exudates were further confirmed to improve the swarming and biofilm formation ability of the OR2-30 strain. Chemotaxis, swarming, and biofilm formation ability were able to influence bacterial colonization. Indeed, the the OR2-30 strain displayed more effective colonization ability in the maize rhizosphere after F. graminearum inoculation. Moreover, lipopeptides produced by OR2-30 were identified as iturins and responsible for suppressing F. graminearum growth. Further study showed that lipopeptides suppressed the growth of F. graminearum by inhibiting conidia formation and germination, inducing reactive oxygen species production and causing cell death in mycelium. Eventually, the OR2-30 strain increased maize resistance against F. graminearum. These results suggested that maize root exudates could recruit B. amyloliquefacines OR2-30 after F. graminearum infection, and that OR2-30 then suppresses the F. graminearum by producing lipopeptides, such as iturins, to protect maize.

The zone II aorta is not a forbidden zone for occlusion in women with morbidly adherent placenta.

AIM: To evaluate the safety and efficacy of balloon occlusion at the Zone II aorta for the management of morbidly adherent placenta. METHODS: From September 2015 to October 2018, a total of 80 consecutive patients who were prenatally diagnosed with morbidly adherent placenta were assigned into two groups: the balloon occlusion group (n = 40) and the non-balloon occlusion group (n = 40).The intraoperative estimated blood loss, blood transfusion, urine output, serum creatinine, blood urea nitrogen and hysterectomy rate were recorded and compared between the two groups. RESULTS: The estimated blood loss in the balloon occlusion group was significantly lower than that in the non-balloon occlusion group (811.75 ± 299.93 ml vs 1529.75 ± 808.01 ml, P < 0.001). The median amount of packed RBCs transfused in the balloon occlusion group and non-balloon occlusion group was 0 U and 2 U, respectively (P = 0.001). The women in the former group had a lower blood transfusion rate than those in the latter group (30% vs 57.5%, P = 0.013). Hysterectomy occurred in none in the balloon occlusion group but in six patients in the non-balloon occlusion group (P = 0.011). CONCLUSION: The middle abdominal aorta (Zone II) is not a forbidden zone for occlusion as long as the single occlusion time is limited to 15 min. Balloon occlusion at the Zone II aorta can effectively reduce blood loss, transfusion requirements and hysterectomy rates in patients with morbidly adherent placenta.

NDV-D90 inhibits 17ß-estradiol-mediated resistance to apoptosis by differentially modulating classic and nonclassic estrogen receptors in breast cancer cells.

Newcastle disease virus (NDV) is endowed with the oncolytic ability to kill tumor cells, while rarely causing side effects in normal cells. Both estrogen receptor α (ERα) and the G protein estrogen receptor (GPER) modulate multiple biological activities in response to estrogen, including apoptosis in breast cancer (BC) cells. Here, we investigated whether NDV-D90, a novel strain isolated from natural sources in China, promoted apoptosis by modulating the expression of ERα or the GPER in BC cells exposed to 17ß-estradiol (E2). We found that NDV-D90 significantly killed the tumor cell lines MCF-7 and BT549 in a time- and dose-dependent manner. We also found that NDV-D90 exerted its effects on the two cell lines mainly by inducing apoptosis but not necrosis. NDV-D90 induced apoptosis via the intrinsic and extrinsic signaling pathways in MCF-7 cells (ER-positive cells) during E2 exposure not only by disrupting the E2/ERα axis and enhancing GPER expression but also by modulating the expression of several apoptosis-related proteins through ERα-and GPER-independent processes. NDV-D90 promoted apoptosis via the intrinsic signaling pathway in BT549 cells (ER-negative cells), possibly by impairing E2-mediated GPER expression. Furthermore, NDV-D90 exerted its antitumor effects in vivo by inducing apoptosis. Overall, these results demonstrated that NDV-D90 promotes apoptosis by differentially modulating the expression of ERα and the GPER in ER-positive and negative BC cells exposed to estrogen, respectively, and can be utilized as an effective approach to treating BC.

Accurate Removal of Trace 17ß-Estradiol and Estrogenic Activity in Blended Systems under a Photoelectrocatalytic Circulating Flow.

Trace 17ß-estradiol (E2) is persistent against advanced treatment when blended with higher concentrations of low-toxicity organics, thus wasting energy. A circulating-flow selective photoelectrocatalysis (CF-SPEC) system is established with a selective E2-TiO2-NR photoanode, accurately reducing 1 µg L-1 E2 to less than 0.1 ng L-1 along with eliminating estrogenic activity even when blended with natural organic matter (NOM) at a thousand times higher concentration. Such high efficiency is derived from the augmented selectivity and activity of E2-TiO2-NRs toward E2 during CF-SPEC. Under a flow, the difference in adsorption capacity between NOM and E2 is further amplified 5.6-fold. Furthermore, the higher initial •OH concentration and faster mass transfer jointly endow CF-SPEC with a stronger oxidation capacity. As a result, the removal of E2 increases by 58.7%, and the elimination of estrogenic activity increases 5.8-fold. In addition, deeper mineralization and less homo- and heterocoupling under CF-SPEC are observed, leading to more thorough estrogenic activity removal. Although additional energy is needed to maintain the flow, there is a 55% decrease in energy consumption due to the accurate removal capacity. This work suggests a combination of flow degradation and surface engineering that can be expanded for the selective removal of toxic trace pollutants in blended systems.

The efficacy and safety of rivaroxaban in coronary artery disease patients with heart failure and sinus rhythm: a systematic review and meta-analysis.

PURPOSE: To explore the efficacy and safety of rivaroxaban in patients with coronary artery disease (CAD), heart failure (HF) and sinus rhythm (SR). METHODS: Comprehensive literature searches were conducted using the PubMed, Cochrane Library, Embase, CNKI and Wanfang databases from inception to February 2021. Randomized controlled trials (RCTs) focusing on the efficacy and safety of new oral anticoagulant (NOAC) therapy in CAD and HF patients in SR were eligible. Statistical analyses were performed using R Programming Language. RESULTS: Three RCTs included 10,658 adult patients treated with antiplatelet drugs with or without rivaroxaban were ultimately analysed. The average follow-up period was 20.4-24 months. Rivaroxaban had a favourable point estimate in myocardial infarction (MI) and stroke (MI rivaroxaban group (3.83%, 203/5306) vs. APT group (4.52%, 214/4731), RR = 0.78, 95% CI 0.65-0.94, P < 0.01, I2 = 0%), (stroke: rivaroxaban group (1.60%, 85/5306) vs. APT group (2.52%, 119/4731), RR = 0.64, 95% CI 0.49-0.85, P < 0.01, I2 = 12%) compared with the placebo. Rivaroxaban was comparable to the placebo for all-cause death and major bleeding (all-cause death: rivaroxaban group (12.27%, 688/5606) vs. APT group (14.59%, 737/5052), RR = 0.73, 95% CI 0.49-1.06, P > 0.05, I2 = 87%), (major bleeding: rivaroxaban group (1.52%, 85/5586) vs. APT group (1.37%, 69/5043), RR = 1.18, 95% CI 0.86-1.62, P > 0.05, I2 = 0%). CONCLUSIONS: In SR patients with CAD and HF, the rates of MI and stroke associated with rivaroxaban combined with APT were lower than those associated with APT alone, and the two treatments had similar rates of all-cause death and major bleeding.

RNA helicase DDX5 suppresses IFN-I antiviral innate immune response by interacting with PP2A-Cß to deactivate IRF3.

DEAD-box (DDX) helicases are critical for recognizing viral nucleic acids to regulate antiviral innate immunity. Although DDX5 has been reported to participate in various virus infection, whether DDX5 regulates innate immune responses and its underlying mechanisms are still unknown. Here, we report that DDX5 is a negative regulator of type I IFN (IFN-I) production in antiviral responses. DDX5 knockdown significantly promoted DNA or RNA virus infection-induced IFN-I production and IFN-stimulated genes (ISGs) expression, while ectopic expression of DDX5 inhibited IFN-I production and promoted viral replication. Furthermore, we found that DDX5 specifically interacted with serine/threonine-protein phosphatase 2 A catalytic subunit beta (PP2A-Cß) and viral infection enhanced the interaction between DDX5 and PP2A-Cß. Besides, PP2A-Cß interacted with IFN regulatory factor 3 (IRF3), and PP2A-Cß knockdown promoted viral infection-induced IRF3 phosphorylation and IFN-I production. In addition, DDX5 knockdown rendered the mice more resistant to viral infection and enhanced antiviral innate immunity in vivo. Thus, DDX5 suppresses IFN-I antiviral innate immune response by interacting with PP2A-Cß to deactivate IRF3. Together, these findings identify a negative role of DDX5 on regulating IFN-I signaling in innate immune responses.

Programmable RNA N1 -Methyladenosine Demethylation by a Cas13d-Directed Demethylase.

N1 -methyladenosine (m1 A) is a prevalent and reversible RNA modification, which plays a crucial role in the regulation of RNA fate and gene expression. However, the lack of tools to precisely manipulate m1 A sites in specific transcripts has hindered efforts to clarify the association between a specific m1 A-modified transcript and its phenotypic outcomes. Here we develop a CRISPR-Cas13d-based tool called reengineered m1 A modification valid eraser (termed "REMOVER") for targeted m1 A demethylation of a specific transcript. The catalytically inactive RfxCas13d (dCasRx) is fused to the m1 A demethylase ALKBH3, and the dCasRx-ALKBH3 fusion protein can mediate potent demethylation of m1 A-modified RNAs. We further find that REMOVER can specifically demethylate m1 A of MALAT1 and PRUNE1 RNAs, thereby significantly increasing their stability. Our study establishes REMOVER as a tool for targeted RNA demethylation of specific m1 A-modified transcripts, which enables further elucidation of the relationship between m1 A modification of specific transcripts and their phenotypic outcomes.

Higher Plaque Burden of Middle Cerebral Artery Is Associated With Recurrent Ischemic Stroke: A Quantitative Magnetic Resonance Imaging Study.

Background and Purpose- This study aims to investigate the association between the characteristics of atherosclerotic plaques of middle cerebral artery and recurrent ischemic stroke using magnetic resonance vessel wall imaging. Methods- One hundred and five patients with ischemic stroke attributed to middle cerebral artery plaque underwent high-resolution black-blood magnetic resonance vessel wall imaging. They were divided into group 1, with the first episode of acute stroke (imaging within 4 weeks of stroke, n=44); group 2, with recurrent acute stroke (n=29); and group 3, with chronic stroke (imaging after 3 months of stroke, n=32). Plaque characteristics including plaque area, plaque burden, contrast-enhancement ratio, eccentricity, and degree of stenosis were measured and compared across 3 groups. Association between plaque characteristics and recurrent strokes was investigated by multivariate analysis. Results- Plaque burden was significantly greater in recurrent stroke group than the other 2 groups (median: group 2, 82.7%, versus group 1, 76.3%, and group 3, 73.4%; P=0.001). Patients with acute stroke had higher enhancement ratio than patients with chronic stroke (median: group 1, 1.59, and group 2, 1.90, versus group 3, 1.33; P=0.014). Comparing to first-onset acute stroke patients, recurrent stroke patients were older, more likely with female sex and hypertension, and had higher plaque burden. After adjustment of clinical factors, plaque burden was the only independent imaging feature associated with recurrent stroke (odds ratio, 2.26, per 10% increase [95% CI, 1.03-4.96]; P=0.042). Conclusions- Higher plaque burden of middle cerebral artery identified on magnetic resonance vessel wall imaging is independently associated with recurrent ischemic stroke.

Emerging roles of RNA methylation in gastrointestinal cancers.

RNA methylation has emerged as a fundamental process in epigenetic regulation. Accumulating evidences indicate that RNA methylation is essential for many biological functions, and its dysregulation is associated with human cancer progression, particularly in gastrointestinal cancers. RNA methylation has a variety of biological properties, including N6-methyladenosine (m6A), 2-O-dimethyladenosine (m6Am), N1-methyladenosine (m1A), 5-methylcytosine (m5C) and 7-methyl guanosine (m7G). Dynamic and reversible methylation on RNA is mediated by RNA modifying proteins called "writers" (methyltransferases) and "erasers" (demethylases). "Readers" (modified RNA binding proteins) recognize and bind to RNA methylation sites, which influence the splicing, stability or translation of modified RNAs. Herein, we summarize the biological functions and mechanisms of these well-known RNA methylations, especially focusing on the roles of m6A in gastrointestinal cancer development.