EMC10 modulates hepatic ER stress and steatosis in an isoform specific manner.

BACKGROUND & AIMS: Endoplasmic reticulum (ER) membrane protein complex subunit 10 (EMC10) has been implicated in obesity. Here we investigated the roles of the two isoforms of EMC10, including a secreted isoform (scEMC10) and an ER membrane-bound isoform (mEMC10), in MASLD. METHODS: Manifold steatotic mouse models and HepG2 cells were employed to investigate the role of EMC10 in the regulation of hepatic PERK-eIF2α-ATF4 signaling and hepatosteatosis. The therapeutic effect of scEMC10-neutralizing antibody on mouse hepatosteatosis was explored. Associations of MASLD with serum scEMC10 and hepatic mEMC10 were determined in two cohorts of participants with MASLD. RESULTS: scEMC10 promoted, while mEMC10 suppressed the activation of hepatocytic PERK-eIF2α-ATF4 signaling. Emc10 gene knockout exacerbated, while hepatic overexpression of mEMC10 ameliorated hepatic ER stress and steatosis in mice challenged with either a MCD diet or tunicamycin, highlighting a direct, suppressive role of mEMC10 in MASLD via modulation of hepatic ER stress. Overexpression of scEMC10 promoted, whereas neutralization of circulating scEMC10 prevented hepatosteatosis in mice with fatty liver, suggesting a progressive role of scEMC10 in MASLD. Clinically, serum scEMC10 increased, while hepatic mEMC10 decreased in participants with MASLD. Correlative analysis indicated serum scEMC10 positively, whereas hepatic mEMC10 negatively correlated with liver fat content and serum ALT, AST, and GGT. CONCLUSIONS: These findings demonstrate a novel, isoform specific role for EMC10 in the pathogenesis of MASLD and identify the secreted isoform as a tractable therapeutic target for MASLD via antibody-based neutralization. IMPACT AND IMPLICATIONS: We have shown the role of EMC10 in the regulation of energy homeostasis and obesity. In this study, we determine the distinct roles of the two isoforms of EMC10 in the regulation of hepatic ER stress and steatosis in mice, and associations of MASLD with different EMC10 isoforms in humans. Our findings delineate a novel regulatory axis for hepatosteatosis and identify EMC10 as a modulator of the PERK-eIF2α-ATF4 signaling cascade that may be of broad physiological significance. Moreover, our pre-clinical and clinical studies clearly provide the foundations for translation of scEMC10 modulation for the treatment of MASLD.

[Research progress of relationship in long-novel coronavirus syndrome and sarcopenia].

At present, the major public health challenges caused by novel coronavirus infection have gradually subside. However, a large number of people are still suffering from long-novel coronavirus syndrome or post-novel coronavirus syndrome. The clinical manifestations of long coronavirus syndrome are related to multiple systems, such as respiratory, circulatory, nervous, digestive and musculoskeletal systems, with various long-term persistent symptoms after novel coronavirus infection. At the same time, the infection of the novel coronavirus is an important cause of frailty and sarcopenia in the elderly population. However, at present, the scholars have not paid enough attention to the skeletal muscle weakness caused by the novel coronavirus. Therefore, this paper focuses on the long-novel coronavirus syndrome and sarcopenia to explore the pathological mechanism of skeletal muscle attenuation caused by the SARS-CoV-2 mediated "cytokine storm", mitochondrial damage, hypoxia state and other links,so as to raise the attention of clinical and academic researchers and improve the clinical strategy of frailty and sarcopenia after novel coronavirus infection.

Recent advances of phenotypic screening strategies in the application of anti-influenza virus drug discovery.

Seasonal and pandemic influenza virus infections not only pose a serious threat to human health but also cause tremendous economic losses and social burdens. However, due to the inherent high variability of influenza virus RNA genomes, the existing anti-influenza virus drugs have been frequently faced with the clinical issue of emerging drug-resistant mutants. Therefore, there is an urgent need to develop efficient and broad-spectrum antiviral agents against wild-type and drug-resistant mutant strains. Phenotypic screening has been widely employed as a reliable strategy to evaluate antiviral efficacy of novel agents independent of their modes of action, either directly targeting viral proteins or regulating cellular factors involved in the virus life cycle. Here, from the point of view of medicinal chemistry, we review the research progress of phenotypic screening strategies by focusing direct acting antivirals against influenza virus. It could provide scientific insights into discovery of a distinctive class of therapeutic candidates that ensure high efficiency but low cytotoxicity, and address issues from circulation of drug-resistant influenza viruses in the future.

Broad-spectrum antiviral strategy: Host-targeting antivirals against emerging and re-emerging viruses.

Viral infections are amongst the most prevalent diseases that pose a significant threat to human health. Targeting viral proteins or host factors represents two primary strategies for the development of antiviral drugs. In contrast to virus-targeting antivirals (VTAs), host-targeting antivirals (HTAs) offer advantages in terms of overcoming drug resistance and effectively combating a wide range of viruses, including newly emerging ones. Therefore, targeting host factors emerges as an extremely promising strategy with the potential to address critical challenges faced by VTAs. In recent years, extensive research has been conducted on the discovery and development of HTAs, leading to the approval of maraviroc, a chemokine receptor type 5 (CCR5) antagonist used for the treatment of HIV-1 infected individuals, with several other potential treatments in various stages of development for different viral infections. This review systematically summarizes advancements made in medicinal chemistry regarding various host targets and classifies them into four distinct catagories based on their involvement in the viral life cycle: virus attachment and entry, biosynthesis, nuclear import and export, and viral release.

Emerging drug design strategies in anti-influenza drug discovery.

Influenza is an acute respiratory infection caused by influenza viruses (IFV), According to the World Health Organization (WHO), seasonal IFV epidemics result in approximately 3-5 million cases of severe illness, leading to about half a million deaths worldwide, along with severe economic losses and social burdens. Unfortunately, frequent mutations in IFV lead to a certain lag in vaccine development as well as resistance to existing antiviral drugs. Therefore, it is of great importance to develop anti-IFV drugs with high efficiency against wild-type and resistant strains, needed in the fight against current and future outbreaks caused by different IFV strains. In this review, we summarize general strategies used for the discovery and development of antiviral agents targeting multiple IFV strains (including those resistant to available drugs). Structure-based drug design, mechanism-based drug design, multivalent interaction-based drug design and drug repurposing are amongst the most relevant strategies that provide a framework for the development of antiviral drugs targeting IFV.

A novel N-heterocycles substituted oseltamivir derivatives as potent inhibitors of influenza virus neuraminidase: discovery, synthesis and biological evaluation.

Our previous studies have shown that the introduction of structurally diverse benzyl side chains at the C5-NH2 position of oseltamivir to occupy 150-cavity contributes to the binding affinity with neuraminidase and anti-influenza activity. To obtain broad-spectrum neuraminidase inhibitors, we designed and synthesised a series of novel oseltamivir derivatives bearing different N-heterocycles substituents that have been proved to induce opening of the 150-loop of group-2 neuraminidases. Among them, compound 6k bearing 4-((r)-2-methylpyrrolidin-1-yl) benzyl group exhibited antiviral activities similar to or weaker than those of oseltamivir carboxylate against H1N1, H3N2, H5N1, H5N6 and H5N1-H274Y mutant neuraminidases. More encouragingly, 6k displayed nearly 3-fold activity enhancement against H3N2 virus over oseltamivir carboxylate and 2-fold activity enhancement over zanamivir. Molecular docking studies provided insights into the explanation of its broad-spectrum potency against wild-type neuraminidases. Overall, as a promising lead compound, 6k deserves further optimisation by fully considering the ligand induced flexibility of the 150-loop.

Development of chalcone-like derivatives and their biological and mechanistic investigations as novel influenza nuclear export inhibitors.

Concerning the emergence of resistance to current anti-influenza drugs, our previous phenotypic-based screening study identified the compound A9 as a promising lead compound. This chalcone analog, containing a 2,6-dimethoxyphenyl moiety, exhibited significant inhibitory activity against oseltamivir-resistant strains (H1N1 pdm09), with an EC50 value of 1.34 µM. However, it also displayed notable cytotoxicity, with a CC50 value of 41.46 µM. Therefore, compound A9 was selected as a prototype structure for further structural optimization in this study. Initially, it was confirmed that the substituting the α,ß-unsaturated ketone with pent-1,4-diene-3-one as a linker group significantly reduced the cytotoxicity of the final compounds. Subsequently, the penta-1,4-dien-3-one group was utilized as a privileged fragment for further structural optimization. Following two subsequent rounds of optimizations, we identified compound IIB-2, which contains a 2,6-dimethoxyphenyl- and 1,4-pentadiene-3-one moieties. This compound exhibited inhibitory effects on oseltamivir-resistant strains comparable to its precursor (compound A9), while demonstrating reduced toxicity (CC50 > 100 µM). Furthermore, we investigated its mechanism of action against anti-influenza virus through immunofluorescence, Western blot, and surface plasmon resonance (SPR) experiments. The results revealed that compound IIB-2 can impede virus proliferation by blocking the export of influenza virus nucleoprotein. Thusly, our findings further emphasize influenza nuclear export as a viable target for designing novel chalcone-like derivatives with potential inhibitory properties that could be explored in future lead optimization studies.

The role of C-peptide in diabetes and its complications: an updated review.

Worldwide, diabetes and its complications have seriously affected people's quality of life and become a serious public health problem. C-peptide is not only an indicator of pancreatic ß-cell function, but also a biologically active peptide that can bind to cell membrane surface signaling molecules and activate downstream signaling pathways to play antioxidant, anti-apoptotic and inflammatory roles, or regulate cellular transcription through internalization. It is complex how C-peptide is related to diabetic complications. Both deficiencies and overproduction can lead to complications, but their mechanisms of action may be different. C-peptide replacement therapy has shown beneficial effects on diabetic complications in animal models when C-peptide is deficient, but results from clinical trials have been unsatisfactory. The complex pattern of the relationship between C-peptide and diabetic chronic complications has not yet been fully understood. Future basic and clinical studies of C-peptide replacement therapies will need to focus on baseline levels of C-peptide in addition to more attention also needs to be paid to post-treatment C-peptide levels to explore the optimal range of fasting C-peptide and postprandial C-peptide maintenance.

Design, synthesis, and mechanistic study of 2-piperazineone-bearing peptidomimetics as novel HIV capsid modulators.

HIV-1 capsid (CA) is an attractive target for its indispensable roles in the viral life cycle. We report the design, synthesis, and mechanistic study of a novel series of 2-piperazineone peptidomimetics as HIV capsid modulators by mimicking the structure of host factors binding to CA. F-Id-3o was the most potent compound from the synthesized series, with an anti-HIV-1 EC50 value of 6.0 µM. However, this series of compounds showed a preference for HIV-2 inhibitory activity, in which Id-3o revealed an EC50 value of 2.5 µM (anti-HIV-2 potency), an improvement over PF74. Interestingly, F-Id-3o did bind HIV-1 CA monomers and hexamers with comparable affinity, unlike PF74, consequently showing antiviral activity in the early and late stages of the HIV-1 lifecycle. Molecular dynamics simulations shed light on F-Id-3o and Id-3o binding modes within the HIV-1/2 CA protein and provide a possible explanation for the increased anti-HIV-2 potency. Metabolic stability assays in human plasma and human liver microsomes indicated that although F-Id-3o has enhanced metabolic stability over PF74, further optimization is necessary. Moreover, we utilized computational prediction of drug-like properties and metabolic stability of F-Id-3o and PF74, which correlated well with experimentally derived metabolic stability, providing an efficient computational pipeline for future preselection based on metabolic stability prediction. Overall, the 2-piperazineone-bearing peptidomimetics are a promising new chemotype in the CA modulators class with considerable optimization potential.

Discovery of N-substituted oseltamivir derivatives as novel neuraminidase inhibitors with improved drug resistance profiles and favorable drug-like properties.

To yield potent neuraminidase inhibitors with improved drug resistance and favorable drug-like properties, two series of novel oseltamivir derivatives targeting the 150-cavity of neuraminidase were designed, synthesized, and biologically evaluated. Among the synthesized compounds, the most potent compound 43b bearing 3-floro-4-cyclopentenylphenzyl moiety exhibited weaker or slightly improved inhibitory activity against wild-type neuraminidases (NAs) of H1N1, H5N1, and H5N8 compared to oseltamivir carboxylate (OSC). Encouragingly, 43b displayed 62.70- and 5.03-fold more potent activity than OSC against mutant NAs of H5N1-H274Y and H1N1-H274Y, respectively. In cellular antiviral assays, 43b exerted equivalent or more potent activities against H1N1, H5N1, and H5N8 compared to OSC with no significant cytotoxicity up to 200 µM. Notably, 43b displayed potent antiviral efficacy in the embryonated egg model, in which achieved a protective effect against H5N1 and H5N8 similar to OSC. Molecular docking studies were implemented to reveal the binding mode of 43b in the binding pocket. Moreover, 43b possessed improved physicochemical properties and ADMET properties compared to OSC by in silico prediction. Taken together, 43b appeared to be a promising lead compound for further investigation.

Progesterone levels associated with proteinuria in male diabetes mellitus patients: A cross-sectional retrospective study.

INTRODUCTION: The relationship between progesterone (P) and diabetic nephropathy (DKD) is unclear. Herein, we investigated the relationship between progesterone and DKD in men and postmenopausal women with type 2 diabetes mellitus. MATERIALS AND METHODS: We recruited 3,556 male and postmenopausal female patients and obtained the dominance ratio (OR) and corresponding 95% confidence intervals (CIs) associated with progesterone by logistic regression analysis after adjusting for potentially confounding variants. RESULTS: We found that progesterone levels were significantly lower in the massive proteinuria and microproteinuria groups compared with the non-DKD group for male patients. Also, microproteinuria and massive proteinuria prevalence were higher in the first (lowest) progesterone quartile than in the second to fourth quartiles. After adjusting for confounders, compared with the first (lowest) progesterone quartile group, the OR for the second to fourth quartiles in the male microproteinuria subgroup, were: Q2: 0.846 (95% CI: 0.581-1.233, P = 0.385); Q3: 0.667 (95% CI: 0.45-0988, P = 0.044); Q4: 0.597 (95% CI: 0.393-0.907, P = 0.016). In the male massive proteinuria subgroup, the OR for the third quartile group was 0.418 (95% CI: 0.201-0.867, P = 0.019). In contrast, no significant association was detected between progesterone and DKD prevalence in the female group. CONCLUSIONS: Progesterone levels were negatively associated with DKD incidence in hospitalized male patients with type 2 diabetes mellitus.

The risk of nonalcoholic fatty liver disease in gout patients with frequent flares: a retrospective cohort study.

OBJECTIVE: Nonalcoholic fatty liver disease (NAFLD) is a common chronic disease that is related to high serum uric acid; however, the association between the frequency of gout flares and NAFLD risk remains unclear. This study aimed to investigate whether frequent gout flares were associated with incident NAFLD and analyze the interaction of frequency of gout flares and Adipo-IR on NAFLD in the gout Chinese population. METHODS: A total of 350 cases of gout patients were enrolled in this retrospective cohort study. Cox proportional hazard regression analyses were performed to determine the association between frequent gout flares and NAFLD during follow-up and analyze the interaction of frequency of gout flares and Adipo-IR on NAFLD. Receiver operating curves (ROC) were plotted to explore the diagnostic value of frequent gout flares and Adipo-IR on the occurrence of NAFLD. RESULTS: NAFLD developed in 78 participants (22.3%) during follow-up. Logistic regression showed that Adipo-IR was an independent factor associated with frequent gout flares risk. The multivariate Cox regression analysis revealed that frequent gout flares and Adipo-IR were associated with NAFLD risk (HR: 7.88, 95% CI: 2.11-29.48, p < 0.01; HR: 1.058, 95% CI: 1.01-1.2, p < 0.05). And ROC showed that both of them had a great discriminant ability to diagnose NAFLD. CONCLUSIONS: Our data showed an independent association between the frequency of gout flares or Adipo-IR and incident NAFLD. Frequent gout flares and elevated Adipo-IR had a good predictive capability towards NAFLD development and played a synergistic role in the development of NAFLD. KEY POINTS: • Frequent gout flares and elevated Adipo-IR had a good diagnostic capability towards NAFLD development. • Frequent gout flares and Adipo-IR played a synergistic role in the development of NAFLD.

Risk Factors and Oncologic Outcomes for Clinical T1 Renal Cell Carcinoma Upstaging to Pathological T3a and The Construction of Predictive Model: A Retrospective Study.

PURPOSE: The study is intended to identify the independent predictors of clinical T1 (cT1) renal cell carcinoma upstaging to pathological T3a (pT3a) and construct the predictive nomogram model. METHODS: The data of cT1 renal cell carcinoma was collected from patients who were treated in the Second Hospital of Tianjin Medical University from January 2010 to December 2016. Mann-Whitney U and chi-square tests were performed to analyze continuous and categorical variables respectively. Univariate and multivariate logistic regression were used to identify the predictors of upstaging. Kaplan-Meier method, log-rank test and Cox regression were performed to analyze survival materials. RESULTS: Among 1,376 cT1 renal cell carcinoma patients, 75 patients were observed upstaging to pT3a, accounting for 5.5%. There were 6 potential predictors of upstaging, i.e age, clinical symptom, tumor size, Fuhrman grade, tumor necrosis and tumor edge regularity. The 5-year recurrence free survival probabilities of upstaging and non-upstaging patients were 73.3% and 91.1%, respectively and upstaging was an independent predictor of recurrence free survival. Two predictive nomograms were constructed and the C-index of them were 0.842 and 0.806, and the calibration curve and decision curve analysis showed highly clinical accuracy of the nomograms. CONCLUSION: Two nomogram models were built to predict the probability of cT1 renal cell carcinoma upstaging to pT3a with highly accuracy and specificity. Upstaging was an independent risk factor of recurrence free survival for cT1 renal cell carcinoma patients.

Circadian secretion rhythm of GLP-1 and its influencing factors.

Circadian rhythm is an inherent endogenous biological rhythm in living organisms. However, with the improvement of modern living standards, many factors such as prolonged artificial lighting, sedentarism, short sleep duration, intestinal flora and high-calorie food intake have disturbed circadian rhythm regulation on various metabolic processes, including GLP-1 secretion, which plays an essential role in the development of various metabolic diseases. Herein, we focused on GLP-1 and its circadian rhythm to explore the factors affecting GLP-1 circadian rhythm and its potential mechanisms and propose some feasible suggestions to improve GLP-1 secretion.

Immunosenescence is a therapeutic target for frailty in older adults: a narrative review.

Background and Objective: Aging refers to a progressive decrease in functional performance, leading to increased mortality risk. At present, life expectancy is increasing worldwide and is expected to exceed 80 years by 2040. However, this increase in life expectancy also indicates a rise in the incidence and prevalence of diseases, such as cardiovascular, neurological, musculoskeletal, and oncological diseases, which are associated with aging. The exact underlying mechanisms of aging remain unknown, and whether it is a programmed process or the consequence of an accumulation of stress events remains unclear. Thus, more scientific research is needed to improve the management of complex and frail patients. Methods: Several databases were searched with the following key words: immunosenescence, inflamm-aging, frailty, sarcopenia and skeletal muscle, etc. Key Content and Findings: Skeletal muscle is the core phenotype of frailty and sarcopenia. Immune aging and skeletal muscle decline interplay with each other and form a vicious circle. Maintaining muscle health is beneficial for immune function and delays the onset of frailty. Particularly, in the context of the ongoing corona virus disease (COVID)-19 pandemic, studies have shown that the elderly are more prone to the consequences of the SARS-CoV-2 virus. It has been reported that the rates of hospitalization in the 65-74, 75-84, and ≥85 years old group were 5×, 8×, and 10× greater than the 18-29 years old group, with corresponding COVID-19-related deaths being 60×, 140×, and 330× that of the younger reference group, respectively. Considering the above, this review aims to discuss the relationship between immunosenescence, skeletal muscle, and frailty, and to explore immunosenescence as a potential therapeutic target to prevent frailty and extend healthspan, with some emphasis on the effects of the COVID-19 pandemic on the elderly. Conclusions: Immunosenescence is a promising potential therapeutic target for frailty and is worthy of further investigation.

Discovery of Novel Boron-Containing N-Substituted Oseltamivir Derivatives as Anti-Influenza A Virus Agents for Overcoming N1-H274Y Oseltamivir-Resistant.

To address drug resistance to influenza virus neuraminidase inhibitors (NAIs), a series of novel boron-containing N-substituted oseltamivir derivatives were designed and synthesized to target the 150-cavity of neuraminidase (NA). In NA inhibitory assays, it was found that most of the new compounds exhibited moderate inhibitory potency against the wild-type NAs. Among them, compound 2c bearing 4-(3-boronic acid benzyloxy)benzyl group displayed weaker or slightly improved activities against group-1 NAs (H1N1, H5N1, H5N8 and H5N1-H274Y) compared to that of oseltamivir carboxylate (OSC). Encouragingly, 2c showed 4.6 times greater activity than OSC toward H5N1-H274Y NA. Moreover, 2c exerted equivalent or more potent antiviral activities than OSC against H1N1, H5N1 and H5N8. Additionally, 2c demonstrated low cytotoxicity in vitro and no acute toxicity at the dose of 1000 mg/kg in mice. Molecular docking of 2c was employed to provide a possible explanation for the improved anti-H274Y NA activity, which may be due to the formation of key additional hydrogen bonds with surrounding amino acid residues, such as Arg152, Gln136 and Val149. Taken together, 2c appeared to be a promising lead compound for further optimization.

Current medicinal chemistry strategies in the discovery of novel HIV-1 ribonuclease H inhibitors.

During HIV-1 genome replication, the viral reverse transcriptase-associated ribonuclease H (RT-associated RNase H) activity hydrolyzes the RNA strand of RNA/DNA heteroduplex intermediates. As of today, HIV-1 RNase H inhibitors (RHIs) remain at an investigational level, although none of them reached clinical trials. Therefore, RNase H remains as an attractive target for drug design and development. In this paper, we review the current status of medicinal chemistry strategies aimed at the discovery of novel RHIs, while discussing problems encountered in their characterization and further development, thereby providing an update on recent progress in the field.

Design, Synthesis and Structure-Activity Relationships of Phenylalanine-Containing Peptidomimetics as Novel HIV-1 Capsid Binders Based on Ugi Four-Component Reaction.

As a key structural protein, HIV capsid (CA) protein plays multiple roles in the HIV life cycle, and is considered a promising target for anti-HIV treatment. Based on the structural information of CA modulator PF-74 bound to HIV-1 CA hexamer, 18 novel phenylalanine derivatives were synthesized via the Ugi four-component reaction. In vitro anti-HIV activity assays showed that most compounds exhibited low-micromolar-inhibitory potency against HIV. Among them, compound I-19 exhibited the best anti-HIV-1 activity (EC50 = 2.53 ± 0.84 µM, CC50 = 107.61 ± 27.43 µM). In addition, I-14 displayed excellent HIV-2 inhibitory activity (EC50 = 2.30 ± 0.11 µM, CC50 > 189.32 µM) with relatively low cytotoxicity, being more potent than that of the approved drug nevirapine (EC50 > 15.02 µM, CC50 > 15.2 µM). Additionally, surface plasmon resonance (SPR) binding assays demonstrated direct binding to the HIV CA protein. Moreover, molecular docking and molecular dynamics simulations provided additional information on the binding mode of I-19 to HIV-1 CA. In summary, we further explored the structure­activity relationships (SARs) and selectivity of anti-HIV-1/HIV-2 of PF-74 derivatives, which is conducive to discovering efficient anti-HIV drugs.