Japanese encephalitis virus NS1 and NS1' proteins induce vimentin rearrangement via the CDK1-PLK1 axis to promote viral replication.

The host cytoskeleton plays crucial roles in various stages of virus infection, including viral entry, transport, replication, and release. However, the specific mechanisms by which intermediate filaments are involved in orthoflavivirus infection have not been well understood. In this study, we demonstrate that the Japanese encephalitis virus (JEV) remodels the vimentin network, resulting in the formation of cage-like structures that support viral replication. Mechanistically, JEV NS1 and NS1' proteins induce the translocation of CDK1 from the nucleus to the cytoplasm and interact with it, leading to the phosphorylation of vimentin at Ser56. This phosphorylation event recruits PLK1, which further phosphorylates vimentin at Ser83. Consequently, these phosphorylation modifications convert the typically filamentous vimentin into non-filamentous "particles" or "squiggles." These vimentin "particles" or "squiggles" are then transported retrogradely along microtubules to the endoplasmic reticulum, where they form cage-like structures. Notably, NS1' is more effective than NS1 in triggering the CDK1-PLK1 cascade response. Overall, our study provides new insights into how JEV NS1 and NS1' proteins manipulate the vimentin network to facilitate efficient viral replication. IMPORTANCE: Japanese encephalitis virus (JEV) is a mosquito-borne orthoflavivirus that causes severe encephalitis in humans, particularly in Asia. Despite the availability of a safe and effective vaccine, JEV infection remains a significant public health threat due to limited vaccination coverage. Understanding the interactions between JEV and host proteins is essential for developing more effective antiviral strategies. In this study, we investigated the role of vimentin, an intermediate filament protein, in JEV replication. Our findings reveal that JEV NS1 and NS1' proteins induce vimentin rearrangement, resulting in the formation of cage-like structures that envelop the viral replication factories (RFs), thus facilitating efficient viral replication. Our research highlights the importance of the interplay between the cytoskeleton and orthoflavivirus, suggesting that targeting vimentin could be a promising approach for the development of antiviral strategies to inhibit JEV propagation.

Carbon Monoxide Signaling: Examining Its Engagement with Various Molecular Targets in the Context of Binding Affinity, Concentration, and Biologic Response.

Carbon monoxide (CO) has been firmly established as an endogenous signaling molecule with a variety of pathophysiological and pharmacological functions, including immunomodulation, organ protection, and circadian clock regulation, among many others. In terms of its molecular mechanism(s) of action, CO is known to bind to a large number of hemoproteins with at least 25 identified targets, including hemoglobin, myoglobin, neuroglobin, cytochrome c oxidase, cytochrome P450, soluble guanylyl cyclase, myeloperoxidase, and some ion channels with dissociation constant values spanning the range of sub-nM to high µM. Although CO's binding affinity with a large number of targets has been extensively studied and firmly established, there is a pressing need to incorporate such binding information into the analysis of CO's biologic response in the context of affinity and dosage. Especially important is to understand the reservoir role of hemoglobin in CO storage, transport, distribution, and transfer. We critically review the literature and inject a sense of quantitative assessment into our analyses of the various relationships among binding affinity, CO concentration, target occupancy level, and anticipated pharmacological actions. We hope that this review presents a picture of the overall landscape of CO's engagement with various targets, stimulates additional research, and helps to move the CO field in the direction of examining individual targets in the context of all of the targets and the concentration of available CO. We believe that such work will help the further understanding of the relationship of CO concentration and its pathophysiological functions and the eventual development of CO-based therapeutics. SIGNIFICANCE STATEMENT: The further development of carbon monoxide (CO) as a therapeutic agent will significantly rely on the understanding of CO's engagement with therapeutically relevant targets of varying affinity. This review critically examines the literature by quantitatively analyzing the intricate relationships among targets, target affinity for CO, CO level, and the affinity state of carboxyhemoglobin and provide a holistic approach to examining the molecular mechanism(s) of action for CO.

Energy-transfer Enabled Divergent Synthesis of Polycyclic γ-Sultines.

A visible-light-initiated energy-transfer enabled radical cyclization for the divergent synthesis of polycyclic γ-sultine derivatives has been developed. The reaction provides an alternative and expeditious access to benzofused γ-sultine frameworks, the analogues of γ-lactones and γ-sultones, and features good functional group compatibility, mild reaction conditions and excellent diastereoselectivity. The robustness and application potential of this method have also been successfully displayed by two gram-scale reactions and the synthesis of polycyclic sultones. Mechanistic studies indicated the transformations through a possible energy-transfer enabled intramolecular radical homolytic substitution or hydrogen atom transfer process mainly.

Novel miniature transendoscopic telerobotic system for endoscopic submucosal dissection (with videos).

BACKGROUND AND AIMS: The lack of tissue traction and instrument dexterity to allow for adequate visualization and effective dissection were the main issues in performing endoscopic submucosal dissection (ESD). Robot-assisted systems may provide advantages. In this study we developed a novel transendoscopic telerobotic system and evaluated its performance in ESD. METHODS: A miniature dual-arm robotic endoscopic assistant for minimally invasive surgery (DREAMS) was developed. The DREAMS system contained the current smallest robotic ESD instruments and was compatible with the commercially available dual-channel endoscope. After the system was established, a prospective randomized controlled study was conducted to validate the performance of the DREAMS-assisted ESD in terms of efficacy, safety, and workload by comparing it with the conventional technique. RESULTS: Two robotic instruments can achieve safe collaboration and provide sufficient visualization and efficient dissection during ESD. Forty ESDs in the stomach and esophagus of 8 pigs were completed by DREAMS-assisted ESD or conventional ESD. Submucosal dissection time was comparable between the 2 techniques, but DREAMS-assisted ESD demonstrated a significantly lower muscular injury rate (15% vs 50%, P = .018) and workload scores (22.30 vs 32.45, P < .001). In the subgroup analysis of esophageal ESD, DREAMS-assisted ESD showed significantly improved submucosal dissection time (6.45 vs 16.37 minutes, P = .002), muscular injury rate (25% vs 87.5%, P = .041), and workload (21.13 vs 40.63, P = .001). CONCLUSIONS: We developed a novel transendoscopic telerobotic system, named DREAMS. The safety profile and technical feasibility of ESD were significantly improved with the assistance of the DREAMS system, especially in the narrower esophageal lumen.

On the Question of Uncatalyzed CO Insertion into a Hydrazone Double Bond: A Comparative Study Using Different CO Sources and Substrates.

Because of endogenous signaling roles of carbon monoxide (CO) and its demonstrated pharmacological effects, there has been extensive interests in developing fluorescent CO probes. Palladium-mediated CO insertion has been successfully used for such applications. However, recent years have seen many publications of using uncatalyzed CO insertion into a hydrazone double bond as a way to sense CO. Such chemistry has no precedents otherwise. Further, the rigor of the CO-sensing work was largely based on using ruthenium-carbonyl complexes such as CORM-3 as CO surrogates, which have been reported to have extensive chemical reactivity and to release largely CO2 instead of CO unless in the presence of a strong nucleophile such as dithionite. For all of these, it is important to reassess the feasibility of such a CO-insertion reaction. By studying two of the reported "CO probes" using CO gas, this study finds no evidence of CO insertion into a hydrazone double bond. Further, the chemical reaction between CO gas and a series of eight hydrazone compounds was conducted, leading to the same conclusion. Such findings are consistent with the state-of-the-art knowledge of carbonylation chemistry and do not support uncatalyzed CO insertion as a mechanism for developing fluorescent CO probes.

CD36 inhibition reduces non-small-cell lung cancer development through AKT-mTOR pathway.

Lung cancer is the most common cause of cancer-related deaths worldwide and is caused by multiple factors, including high-fat diet (HFD). CD36, a fatty acid receptor, is closely associated with metabolism-related diseases, including cardiovascular disease and cancer. However, the role of CD36 in HFD-accelerated non-small-cell lung cancer (NSCLC) is unclear. In vivo, we fed C57BL/6J wild-type (WT) and CD36 knockout (CD36-/-) mice normal chow or HFD in the presence or absence of pitavastatin 2 weeks before subcutaneous injection of LLC1 cells. In vitro, A549 and NCI-H520 cells were treated with free fatty acids (FFAs) to mimic HFD situation for exploration the underlying mechanisms. We found that HFD promoted LLC1 tumor growth in vivo and that FFAs increased cell proliferation and migration in A549 and NCI-H520 cells. The enhanced cell or tumor growth was inhibited by the lipid-lowering agent pitavastatin, which reduced lipid accumulation. More importantly, we found that plasma soluble CD36 (sCD36) levels were higher in NSCLC patients than those in healthy ones. Compared to that in WT mice, the proliferation of LLC1 cells in CD36-/- mice was largely suppressed, which was further repressed by pitavastatin in HFD group. At the molecular level, we found that CD36 inhibition, either with pitavastatin or plasmid, reduced proliferation- and migration-related protein expression through the AKT/mTOR pathway. Taken together, we demonstrate that inhibition of CD36 expression by pitavastatin or other inhibitors may be a viable strategy for NSCLC treatment.

Activation of CTU2 expression by LXR promotes the development of hepatocellular carcinoma.

Cytosolic thiouridylase 2 (CTU2) is an enzyme modifying transfer RNAs post-transcriptionally, which has been implicated in breast cancer and melanoma development. And we found CTU2 participated in hepatocellular carcinoma (HCC) progression here. HepG2 cells as well as xenograft nude mice model were employed to investigate the role of CTU2 in HCC development in vitro and in vivo respectively. Further, we defined CTU2 as a Liver X receptor (LXR) targeted gene, with a typical LXR element in the CTU2 promoter. CTU2 expression was activated by LXR agonist and depressed by LXR knockout. Interestingly, we also found CTU2 took part in lipogenesis by directly enhancing the synthesis of lipogenic proteins, which provided a novel mechanism for LXR regulating lipid synthesis. Meanwhile, lipogenesis was active during cell proliferation, particularly in tumor cells. Reduction of CTU2 expression was related to reduced tumor burden and synergized anti-tumor effect of LXR ligands by inducing tumor cell apoptosis and inhibiting cell proliferation. Taken together, our study identified CTU2 as an LXR target gene. Inhibition of CTU2 expression could enhance the anti-tumor effect of LXR ligand in HCC, identifying CTU2 as a promising target for HCC treatment and providing a novel strategy for the application of LXR agonists in anti-tumor effect.

Individualized small bowel preparation for computed tomography enterography: A prospective randomized controlled trial.

BACKGROUND AND AIM: The study aims to evaluate the feasibility of body mass index (BMI)-based individualized small bowel preparation for computed tomography enterography (CTE). METHODS: In this prospective randomized controlled study, patients undergoing CTE were randomly assigned to the individualized group or standardized group. Those in individualized group were given different volumes of mannitol solution based on BMI (1000 mL for patients with BMI < 18.5 kg/m2, 1500 mL for patients with 18.5 kg/m2 ≤ BMI < 25 kg/m2 and 2000 mL for patients with BMI ≥ 25 kg/m2) while patients in the standardized group were all asked to consume 1500-mL mannitol solution. CTE images were reviewed by two experienced radiologists blindly. Each segment of the small bowel was assessed for small bowel image quality and disease detection rates. Patients were invited to record a diary regarding adverse events and acceptance. RESULTS: A total of 203 patients were enrolled and randomly divided into two groups. For patients with BMI < 18.5 kg/m2, 1000-mL mannitol solution permitted a significantly lower rate of flatulence (P = 0.045) and defecating frequency (P = 0.011) as well as higher acceptance score (P = 0.015), but did not affect bowel image quality and diseases detection compared with conventional dosage. For patients with BMI ≥ 25 kg/m2, 2000-mL mannitol solution provided better overall image quality (P = 0.033) but comparable rates of adverse events and patients' acceptance compared with conventional dosage. CONCLUSIONS: Individualized bowel preparation could achieve both satisfactory image quality and patients' acceptance thus might be an acceptable alternative in CTE.

IS6 family insertion sequences promote optrA dissemination between plasmids varying in transfer abilities.

Plasmids are the primary vectors for intercellular transfer of the oxazolidinone and phenicol cross-resistance gene optrA, while insertion sequences (ISs) are mobile genetic elements that can mobilize plasmid-borne optrA intracellularly. However, little is known about how the IS-mediated intracellular mobility facilitates the dissemination of the optrA gene between plasmid categories that vary in transfer abilities, including non-mobilizable, mobilizable, and conjugative plasmids. Here, we performed a holistic genomic study of 52 optrA-carrying plasmids obtained from searches guided by the Comprehensive Antibiotic Resistance Database. Among the 132 ISs identified within 10 kbp from the optrA gene in the plasmids, IS6 family genes were the most prevalent (86/132). Homologous gene arrays containing IS6 family genes were shared between different plasmids, especially between mobilizable and conjugative plasmids. All these indicated the central role of IS6 family genes in disseminating plasmid-borne optrA. Thirty-three of the 52 plasmids were harbored by Enterococcus faecalis found mainly in humans and animals. By Nanopore sequencing and inverse PCR, the potential of the enterococcal optrA to be transmitted from a mobilizable plasmid to a conjugative plasmid mediated by IS6 family genes was further confirmed in Enterococcus faecalis strains recovered from the effluents of anaerobic digestion systems for treating chicken manure. Our findings highlight the increased intercellular transfer abilities and dissemination risk of plasmid-borne optrA gene caused by IS-mediated intracellular mobility, and underscore the importance of routinely monitoring the dynamic genetic contexts of clinically important antibiotic resistance genes to effectively control this critical public health threat. KEY POINTS: • IS6 was prevalent in optrA-plasmids varying in intercellular transfer abilities. • Enterococcal optrA-plasmids were widespread among human, animal, and the environment. • IS6 elevated the dissemination risk of enterococcal optrA-plasmids.

Titanium dioxide nanoparticles alleviates polystyrene nanoplastics induced growth inhibition by modulating carbon and nitrogen metabolism via melatonin signaling in maize.

BACKGROUND: Nanoplastics, are emerging pollutants, present a potential hazard to food security and human health. Titanium dioxide nanoparticles (Nano-TiO2), serving as nano-fertilizer in agriculture, may be important in alleviating polystyrene nanoplastics (PSNPs) toxicity. RESULTS: Here, we performed transcriptomic, metabolomic and physiological analyzes to identify the role of Nano-TiO2 in regulating the metabolic processes in PSNPs-stressed maize seedlings (Zea mays L.). The growth inhibition by PSNPs stress was partially relieved by Nano-TiO2. Furthermore, when considering the outcomes obtained from RNA-seq, enzyme activity, and metabolite content analyses, it becomes evident that Nano-TiO2 significantly enhance carbon and nitrogen metabolism levels in plants. In comparison to plants that were not subjected to Nano-TiO2, plants exposed to Nano-TiO2 exhibited enhanced capabilities in maintaining higher rates of photosynthesis, sucrose synthesis, nitrogen assimilation, and protein synthesis under stressful conditions. Meanwhile, Nano-TiO2 alleviated the oxidative damage by modulating the antioxidant systems. Interestingly, we also found that Nano-TiO2 significantly enhanced the endogenous melatonin levels in maize seedlings. P-chlorophenylalanine (p-CPA, a melatonin synthesis inhibitor) declined Nano-TiO2-induced PSNPs tolerance. CONCLUSIONS: Taken together, our data show that melatonin is involved in Nano-TiO2-induced growth promotion in maize through the regulation of carbon and nitrogen metabolism.

scAPAatlas: an atlas of alternative polyadenylation across cell types in human and mouse.

Alternative polyadenylation (APA) has been widely recognized as a crucial step during the post-transcriptional regulation of eukaryotic genes. Recent studies have demonstrated that APA exerts key regulatory roles in many biological processes and often occurs in a tissue- and cell-type-specific manner. However, to our knowledge, there is no database incorporating information about APA at the cell-type level. Single-cell RNA-seq is a rapidly evolving and powerful tool that enable APA analysis at the cell-type level. Here, we present a comprehensive resource, scAPAatlas (http://www.bioailab.com:3838/scAPAatlas), for exploring APA across different cell types, and interpreting potential biological functions. Based on the curated scRNA-seq data from 24 human and 25 mouse normal tissues, we systematically identified cell-type-specific APA events for different cell types and examined the correlations between APA and gene expression level. We also estimated the crosstalk between cell-type-specific APA events and microRNAs or RNA-binding proteins. A user-friendly web interface has been constructed to support browsing, searching and visualizing multi-layer information of cell-type-specific APA events. Overall, scAPAatlas, incorporating a rich resource for exploration of APA at the cell-type level, will greatly help researchers chart cell type with APA and elucidate the biological functions of APA.

Exploring the Diagnostic Potential of EPB41L3 Methylation in Cervical Cancer and Precancerous Lesions: A Systematic Review and Meta-Analysis.

OBJECTIVE: This meta-analysis aimed to comprehensively evaluate the diagnostic use of erythrocyte membrane protein band 4.1like3 (EPB41L3) methylation detection in cervical cancer (CC) and its precancerous lesions. METHODS: CNKI, Wanfang, Cochrane Library, PubMed, and Ovid databases were searched using a combination of subject headings and free words. Pertinent data were retrieved after screening for inclusion and exclusion criteria, and the quality of the included studies was evaluated using QUADAS-2 criteria. The appropriate software was used for heterogeneity analysis and combined effect size calculation. Additionally, sensitivity analysis was used to evaluate the robustness of the combined results, and meta-regression and subgroup analysis were conducted to investigate the origins of heterogeneity. RESULTS: This meta-analysis included six studies, including 525 healthy individuals, 182 cervical intraepithelial neoplasia 1 (CIN1) samples, 182 CIN2 samples, 281 CIN3 samples, and 226 CC samples. EPB41L3 methylation detection for CIN2 and above lesions demonstrated combined sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio (DOR), and the area under the curve of the comprehensive receiver operating characteristic curve of 0.67, 0.76, 3.19, 0.41, 7.60, and 0.80, respectively; CIN3 and above lesions demonstrated these evaluations at 0.73, 0.84, 4.35, 0.33, 23.94, and 0.90, respectively. Meta-regression analysis revealed that the population, time, sample type, detection method, literature quality, and sample size were not significant sources of heterogeneity affecting the combined diagnostic efficacy of CIN2 and above lesions (p > 0.05). Subgroup analysis revealed higher combined diagnostic values of CIN2 and above lesions in retrospective studies, tissue samples, and Chinese populations, with DORs of 41.03, 14.59, and 13.70, respectively. CONCLUSION: EPB41L3 methylation demonstrated a relatively low diagnostic performance in CC and precancerous lesions. However, it merits further investigation as a potential biomarker. Integrating it with multiple gene detection, human papillomavirus testing, and ThinPrep liquid-based cytology test examination is recommended to explore improved diagnostic strategies for CC and its precancerous lesions.

Effect of use of NSAIDs or steroids during the acute phase of pain on the incidence of chronic pain: a systematic review and meta-analysis of randomised trials.

BACKGROUND: This study is the first to summarize the evidence on how the use of anti-inflammatory drugs during acute pain has an impact on the development of chronic pain. METHODS: Randomized controlled trials retrieved from nine databases included anti-inflammatory drugs (NSAIDs or steroids) versus non-anti-inflammatory drugs in patients with acute pain and reported the incidence of chronic pain. No specified date, age, sex, or language restrictions. Subgroup analyses were performed according to pain classification, follow-up time, and medication. The GRADE method was used to evaluate quality of evidence. RESULTS: A total of 29 trials (5220 patients) were included. Steroids or NSAIDs did not reduce the incidence of chronic nociceptive pain. Steroid use in acute phase significantly reduced the incidence of chronic neuropathic pain. In subgroup analysis, benefits were observed for methylprednisolone and dexamethasone, with some adverse effects. Steroids or NSAIDs were statistically significant in reducing pain intensity over 1 year, but the effect size was too small, and whether the long-term effect is clinically relevant needs to be further studied. CONCLUSION: Quality of the evidence was low to moderate. No drug can be recommended to prevent chronic nociceptive pain. Injections of steroids (methylprednisolone or dexamethasone) during the acute phase reduce the incidence of chronic neuropathic pain, but most included studies also used local anesthetics. The results are indirect and need to be interpreted with caution. The pooled data effect sizes for pain intensity were small, so the clinical relevance was unclear. Study registration PROSPERO (CRD42022367030).

Characteristics of and foundation application among Chinese females with sensitive skin.

OBJECTIVE: We conducted a study on women with sensitive skin of various skin tones to analyse their skin characteristics and preferences for foundation shades. METHODS: Volunteers were categorized based on their individual typological angle, and their preferences were assessed using self-perception and software-based mass aesthetic assessment. The Baumann Questionnaire is a valuable tool for identifying patients with sensitive skin and gaining a comprehensive understanding of their skin sensitivity. The skin characteristics of two groups were compared using a more suitable classification method. RESULTS: Individuals diagnosed with sensitive skin typically have skin tones classified as Types I, II and III, with Type I being the most common in sensitive skin cases. The sensitive group exhibited higher levels of transepidermal water loss, lighter skin tone, lower yellowness, increased glossiness, higher haemoglobin content, more acne, fewer blackheads, and fewer pores. Among them, Type I skin is characterized by lower elasticity, increased oiliness, higher hydration levels and fewer visible pores. Type II skin is characterized by lower hydration levels, higher oiliness and increased redness. Type III exhibits more pores, decreased oiliness and enhanced elasticity. Foundations No. 2 and No. 3 are fairer than foundations No. 1 and No. 4. In the self-assessment, Type I and Type II subjects preferred No. 3, while Type III subjects preferred No. 1 and No. 4 because they matched their skin tone. The results of the software evaluation showed that popular aesthetics preferred Type I and Type II to use No. 2, and Type III to use No. 2 and No. 3, as they resulted in a fairer complexion. CONCLUSION: Sensitive skin of different skin tone types confronts different skin problems. The findings also highlight the public's inclination towards lighter foundation shades, despite the common practice of selecting shades that harmonize with one's inherent skin tone.

OBJECTIF: Nous avons mené une étude sur des femmes à la peau sensible de différentes carnations afin d'analyser les caractéristiques de leur peau et leurs préférences en matière de teintes de fond de teint. MÉTHODES: Les volontaires ont été classées en fonction de leur angle typologique individuel et leurs préférences ont été évaluées à l'aide d'une auto­perception et d'une évaluation esthétique de masse basée sur un logiciel. Le questionnaire de Baumann est un outil précieux pour identifier les patients à la peau sensible et obtenir une compréhension globale de leur sensibilité cutanée. Les caractéristiques cutanées de deux groupes ont été comparées à l'aide d'une méthode de classification plus appropriée. RÉSULTATS: Les personnes chez qui l'on a diagnostiqué une peau sensible ont généralement des teintes de peau classées en types I, II et III, le type I étant le plus courant dans les cas de peau sensible. Le groupe sensible présente des niveaux plus élevés de perte d'eau transépidermique, un teint plus clair, une couleur moins jaune, une brillance accrue, une teneur en hémoglobine plus élevée, plus d'acné, moins de points noirs et moins de pores. Parmi eux, la peau de type I se caractérise par une élasticité plus faible, un taux de sébum plus élevé, des niveaux d'hydratation plus élevés et moins de pores visibles. La peau de type II se caractérise par des niveaux d'hydratation plus faibles, un taux de sébum plus élevé et des rougeurs plus importantes. Le type III présente plus de pores, une diminution de l'aspect gras et une meilleure élasticité. Les fonds de teint n° 2 et n° 3 sont plus clairs que les fonds de teint n° 1 et n° 4. Lors de l'auto­évaluation, les sujets des types I et II ont préféré le fond de teint n° 3, tandis que les sujets du type III ont préféré le fond de teint n° 1 et le fond de teint n° 4 parce qu'ils correspondaient à leur carnation. Les résultats de l'évaluation du logiciel ont montré que l'esthétique populaire préférait que les sujets de type I et de type II utilisent le n° 2, et que les sujets de type III utilisent le n° 2 et le n° 3, car ils donnaient un teint plus clair. CONCLUSION: Les peaux sensibles de différents types de carnation sont confrontées à des problèmes cutanés différents. Les résultats mettent également en évidence le penchant du public pour les teintes de fond de teint plus claires, malgré la pratique courante consistant à choisir des teintes qui s'harmonisent avec le teint inhérent à la peau.

Mutual leveraging of proximity effects and click chemistry in chemical biology.

Nature has the remarkable ability to realize reactions under physiological conditions that normally would require high temperature and other forcing conditions. In doing so, often proximity effects such as simultaneous binding of two reactants in the same pocket and/or strategic positioning of catalytic functional groups are used as ways to achieve otherwise kinetically challenging reactions. Though true biomimicry is challenging, there have been many beautiful examples of how to leverage proximity effects in realizing reactions that otherwise would not readily happen under near-physiological conditions. Along this line, click chemistry is often used to endow proximity effects, and proximity effects are also used to further leverage the facile and bioorthogonal nature of click chemistry. This review brings otherwise seemingly unrelated topics in chemical biology and drug discovery under one unifying theme of mutual leveraging of proximity effects and click chemistry and aims to critically analyze the biomimicry use of such leveraging effects as powerful approaches in chemical biology and drug discovery. We hope that this review demonstrates the power of employing mutual leveraging proximity effects and click chemistry and inspires the development of new strategies that will address unmet needs in chemistry and biology.

Inhibition of high-fat diet-induced obesity via reduction of ER-resident protein Nogo occurs through multiple mechanisms.

Obesity is a risk factor for insulin resistance, type 2 diabetes, and cardiovascular diseases. Reticulon-4 (Nogo) is an endoplasmic reticulum-resident protein with unclear functions in obesity. Herein, we investigated the effect of Nogo on obesity and associated metabolic disorders. Human serum samples were collected to explore the relationship between circulating Nogo-B and body mass index value. Nogo-deficient and WT littermate control mice were fed normal chow or high-fat diet (HFD) for 14 weeks, and HFD-induced obese C57BL/6J mice were injected scrambled or Nogo siRNA for 2 weeks. We found that in human and mouse serum, Nogo-B was positively correlated to body mass index/bodyweight and lipid profiles. Reduced Nogo (by genetic deletion or siRNA transfection) protected mice against HFD-induced obesity and related metabolic disorders. We demonstrate that Nogo deficiency reversed HFD-induced whitening of brown adipose tissue, thereby increasing thermogenesis. It also ameliorated lipid accumulation in tissues by activating the adiponectin-adiponectin receptor 1-AMP-activated kinase α signaling axis. Finally, Nogo deficiency potently reduced HFD-induced serum proinflammatory cytokines and infiltration of macrophages into metabolic organs, which is related to enhanced NF-κB p65 degradation via the lysosome pathway. Collectively, our study suggests that reduced levels of Nogo protect mice against HFD-induced obesity by increasing thermogenesis and energy metabolism while inhibiting NF-κB-mediated inflammation. Our results indicate that inhibition of Nogo may be a potential strategy for obesity treatment.

De Novo Construction of Fluorophores via CO Insertion-Initiated Lactamization: A Chemical Strategy toward Highly Sensitive and Highly Selective Turn-On Fluorescent Probes for Carbon Monoxide.

Extensive studies in the last few decades have led to the establishment of CO as an endogenous signaling molecule and subsequently to the exploration of CO's therapeutic roles. In the current state, there is a critical conundrum in CO-related research: the extensive knowledge of CO's biological effects and yet an insufficient understanding of the quantitative correlations between the CO concentration and biological responses of various natures. This conundrum is partially due to the difficulty in examining precise concentration-response relationships of a gaseous molecule. Another reason is the need for appropriate tools for the sensitive detection and concentration determination of CO in the biological system. We herein report a new chemical approach to the design of fluorescent CO probes through de novo construction of fluorophores by a CO insertion-initiated lactamization reaction, which allows for ultra-low background and exclusivity in CO detection. Two series of CO detection probes have been designed and synthesized using this strategy. Using these probes, we have extensively demonstrated their utility in quantifying CO in blood, tissue, and cell culture and in cellular imaging of CO from exogenous and endogenous sources. The probes described will enable many biology and chemistry labs to study CO's functions in a concentration-dependent fashion with very high sensitivity and selectivity. The chemical and design principles described will also be applicable in designing fluorescent probes for other small molecules.

Sensing a CO-Releasing Molecule (CORM) Does Not Equate to Sensing CO: The Case of DPHP and CORM-3.

Carbon monoxide (CO) is an endogenous signaling molecule with demonstrated pharmacological effects. For studying CO biology, there is a need for sensitive and selective fluorescent probes for CO as research tools. In developing such probes, CO gas and/or commercially available metal-carbonyl-based "CO-releasing molecules" (CORMs) have been used as CO sources. However, new findings are steadily emerging that some of these commonly used CORMs do not release CO reliably in buffers commonly used for studying such CO probes and have very pronounced chemical reactivities of their own, which could lead to the erroneous identification of "CO probes" that merely detect the CORM used, not CO. This is especially true when the CO-sensing mechanism relies on chemistry that is not firmly established otherwise. Cu2+ can quench the fluorescence of an imine-based fluorophore, DPHP, presumably through complexation. The Cu2+-quenched fluorescence was restored through the addition of CORM-3, a Ru-based CORM. This approach was reported as a new "strategy for detecting carbon monoxide" with the proposed mechanism being dependent on CO reduction of Cu2+ to Cu1+ under near-physiological conditions ( Anal. Chem. 2022, 94, 11298-11306). The study only used CORM-3 as the source of CO. CORM-3 has been reported to have very pronounced redox reactivity and is known not to release CO in an aqueous solution unless in the presence of a strong nucleophile. To assess whether the fluorescent response of the DPHP-Cu(II) cocktail to CORM-3 was truly through detecting CO, we report experiments using both pure CO and CORM-3. We confirm the reported DPHP-Cu(II) response to CORM-3 but not pure CO gas. Further, we did not observe the stated selectivity of DPHP for CO over sulfide species. Along this line, we also found that a reducing agent such as ascorbate was able to induce the same fluorescent turn-on as CORM-3 did. As such, the DPHP-Cu(II) system is not a CO probe and cannot be used to study CO biology. Corollary to this finding, it is critical that future work in developing CO probes uses more than a chemically reactive "CO donor" as the CO source. Especially important will be to confirm the ability of the "CO probe" to detect CO using pure CO gas or another source of CO.

Toward "CO in a Pill": Silica-Immobilized Organic CO Prodrugs for Studying the Feasibility of Systemic Delivery of CO via In Situ Gastrointestinal CO Release.

Carbon monoxide (CO), an endogenous signaling molecule, is known to exert a range of pharmacological effects, including anti-inflammation, organ protection, and antimetastasis in various animal models. We have previously shown the ability of organic prodrugs to deliver CO systemically through oral administration. As part of our efforts for the further development of these prodrugs, we are interested in minimizing the potential negative impact of the "carrier" portion of the prodrug. Along this line, we have previously published our work on using benign "carriers" and physically trapping the "carrier" portion in the gastrointestinal (GI) tract. We herein report our feasibility studies on using immobilized organic CO prodrugs for oral CO delivery while minimizing systemic exposure to the prodrug and the "carrier portion." In doing so, we immobilize a CO prodrug to silica microparticles, which are generally recognized as safe by the US FDA and known to provide large surface areas for loading and water accessibility. The latter point is essential for the hydrophobicity-driven activation of the CO prodrug. Amidation-based conjugation with silica is shown to provide 0.2 mmol/g loading degree, effective prodrug activation in buffer with comparable kinetics as the parent prodrug, and stable tethering to prevent detachment. One representative silica conjugate, SICO-101, is shown to exhibit anti-inflammation activity in LPS-challenged RAW264.7 cells and to deliver CO systemically in mice through oral administration and GI CO release. We envision this strategy as a general approach for oral CO delivery to treat systemic and GI-specific inflammatory conditions.

Incidence and Mortality of Post-Polypectomy Colorectal Cancer in Patients with Low-Risk Adenomas: A Systematic Review and Meta-Analysis of Observational Studies.

INTRODUCTION: The long-term risks of post-polypectomy colorectal cancer (CRC) incidence and mortality among patients with low-risk adenomas (LRAs) are unclear. This study aimed to perform a systematic review and meta-analysis of the risk of CRC incidence and mortality following LRAs removal. METHODS: We searched the PubMed, Embase, and Cochrane library for studies that reported the risk of metachronous CRC incidence and mortality after colonoscopy. The primary outcome was the risk of CRC incidence and mortality in patients with LRAs. Random-effects models were used to calculate the pooled risk ratio (RR) with a 95% confidence interval (CI). RESULTS: Thirteen observational studies with 1,750,305 patients (45.4% male; follow-up: 4.5-16.5 years) were included. A meta-analysis of seven studies showed a higher CRC incidence in patients with LRAs than those without adenomas (per 10,000 person-years: 5.2 vs. 3.9; RR 1.25 [95% CI 1.05-1.49], I2 = 0%). However, the CRC-related death rate was not significantly different between the two groups (RR 1.13 [95% CI 0.75-1.69], I2 = 0%). When compared with the general population, the meta-analysis showed a significantly lower risk of CRC incidence in patients with LRAs (RR 0.59 [95% CI 0.45-0.77], I2 = 0%), and another three studies, which could not be pooled, showed a reduction in the risk of CRC-related death in the LRAs group. CONCLUSIONS: Patients with LRAs have a small but higher risk of post-polypectomy CRC incidence than patients without adenomas. The marginally higher absolute incidence seemed insufficient for more intensive surveillance colonoscopy, but the significant difference suggested different follow-up strategies between patients with LRAs and those without adenomas.