Interfering hepatitis B virus (HBV) capsid assembly holds promise as a therapeutic approach for chronic hepatitis B (CHB). Novel anti-HBV agents are urgently needed to overcome drug resistance challenges, with targeted protein degradation (TPD) emerging as a hopeful strategy. Herein, we report the first degradation of HBV core protein (HBC), a multifunctional structural protein, using small-molecule degraders developed by hydrophobic tagging (HyT) technology. Structure-activity relationship (SAR) analysis identified compound HyT-S7, featuring an adamantyl group, exhibiting potent inhibitory activity (EC₅₀ = 0.46 μmol/L, HepAD38 cells) and degradation ability (DC₅₀ = 3.02 ± 0.54 μmol/L) in a dose- and time-dependent manner. Mechanistic studies demonstrated that the autophagy-lysosome pathway was a potential driver of HyT-S7-induced HBC degradation. Remarkably, HyT-S7 effectively degraded 11 drug-resistant mutants, including highly resistant strains P25G and T33N, to Phase III drug GLS4. Furthermore, cellular thermal shift assay, surface plasmon resonance assay, and molecular dynamics simulations revealed the precise mode of HyT-S7 binding to HBC with the adamantyl group potentially mimicking protein misfolding to facilitate HBC degradation. This first proof-of-concept study highlights the potential of HyT-mediated TPD in HBC as a promising avenue for discovering novel HBV and other antiviral agents with favorable drug resistance profiles.

The main protease (M^pro) of SARS-CoV-2 is an attractive target in anti-COVID-19 therapy for its high conservation and major role in the virus life cycle. The covalent M^pro inhibitor nirmatrelvir (in combination with ritonavir, a pharmacokinetic enhancer) and the non-covalent inhibitor ensitrelvir have shown efficacy in clinical trials and have been approved for therapeutic use. Effective antiviral drugs are needed to fight the pandemic, while non-covalent M^pro inhibitors could be promising alternatives due to their high selectivity and favorable druggability. Numerous non-covalent M^pro inhibitors with desirable properties have been developed based on available crystal structures of M^pro. In this article, we describe medicinal chemistry strategies applied for the discovery and optimization of non-covalent M^pro inhibitors, followed by a general overview and critical analysis of the available information. Prospective viewpoints and insights into current strategies for the development of non-covalent M^pro inhibitors are also discussed.

Abstract: Hyperuricemia is a metabolic disease caused by elevated uric acid in the body, and is closely related to the increased risk of cardiovascular disease, metabolic disorders, and renal complications. In the development process of uric acid-lowering drugs, activity evaluation is a crucial step. At present, the activity screening methods of uric acid-lowering drugs can be roughly divided into two categories: in vitro and in vivo. In vitro screening is mainly for such targets as xanthine oxidase, urate transporters, and purine nucleoside phosphorylase, etc.; while in vivo screening is achieved by rodent, poultry and organoid models. In this article, the activity evaluation methods for uric acid-lowering compounds are comprehensively summarized both in vitro and in vivo, aiming to provide some insight for the development of uric acid-lowering drugs.

Objective:To investigate differences in bacterial and fungal microbiome between infected nails and healthy nails among patients with onychomycosis.Methods:Nail scraping samples were collected from infected nails and healthy nails of 31 patients with onychomycosis, who visited Dalian Dermatosis Hospital from August 2020 to July 2021. The total DNA of nail microbiota was extracted, and the V3-V4 regions of the bacterial 16S rDNA gene and the fungal internal transcribed spacer (ITS) region were amplified and sequenced using Illumina technology. The USEARCH and mothur softwares were used for data cluster analysis to obtain the operational taxonomic units (OTUs) , Wilcoxon rank sum test was used to analyze α diversity, analysis of similarities (ANOSIM) was performed to analyze β diversity, linear discriminant analysis of effect size (LEfSe) was performed to evaluate the species difference.Results:Among the 31 patients with onychomycosis, 16 were males and 15 were females. According to the age, they were divided into young group (18 - 35 years old, 10 cases) , middle-aged group (36 - 60 years old, 11 cases) , and elderly group (over 60 years old, 10 cases) . As the α-diversity analysis revealed, the infected nail group showed significantly decreased Shannon index ( W = 290, P = 0.007) , but significantly increased Simpson index ( W = 663, P = 0.010) compared with the healthy nail group, suggesting that the diversity and evenness of bacterial communities were lower in the infected nail group than in the healthy nail group; however, there was no significant difference in the diversity of fungal communities between the infected nail group and healthy nail group. The β-diversity analysis based on the unweighted-UniFrac distance matrix showed no significant difference in the fungal or bacterial community composition between the infected nail group and healthy nail group (bacterial communities: R = 0.0052, P = 0.331; fungal communities: R = 0.0036, P = 0.337) ; the β-diversity analysis based on the weighted-UniFrac distance matrix showed significant differences in the abundance of bacterial and fungal communities between the two groups (both P = 0.001) . In terms of the species composition, the bacterial flora with significantly decreased abundance in the infected nail group compared with the healthy nail group included Bacteroidetes, Proteobacteria, Betaproteobacteria, Burkholderiales, Ralstonia, Sphingomonas and Streptococcus, while the abundance of Bacilli, Bacillales and Staphylococcus was significantly higher in the infected nail group than in the healthy nail group. Compared with the healthy nail group, the fungal flora with significantly increased abundance in the infected nail group included Eurotiomycetes, Onygenales, Leotiomycetes-ord-incertae-sedis, Arthrodermataceae, Periconia, Erysiphe, Tilletiopsis, Trichophyton, Erysiphe cruciferarum, Trichophyton rubrum, Malassezia sympodialis, while the abundance of Saccharomycetes, Saccharomycetales, Saccharomycetaceae, Dothioraceae, Candida and Alternaria was significantly lower in the infected nail group than in the healthy nail group. Conclusion:The diversity and abundance of bacterial communities significantly differed between infected nails and healthy nails among patients with onychomycosis, while only the abundance of fungal communities differed between the two groups, and perhaps there was correlations between some bacterial and fungal communities.

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.

Objective To explore the predictive markers of senescence-associated secretory phenotype(SASP)in osteoarthritis(OA).Methods OA datasets were screened by the Gene Expression Omnibus(GEO)database,while SASP-related genes were collected by PubMed.Three machine learning algorithms,including least absolute shrinkage and selection operator(LASSO),support vector machines recursive feature elimination(SVM-RFE),and random forest(RF),were used to screen the candidate predictive markers of SASP genes in OA,and the OA prediction model was constructed using the overlapping genes identified by the machine learning algo-rithms.CIBERSORT was used to explore the degree of peripheral blood immune cell infiltration in OA versus normal samples.The miRNA-transcription factor-mRNA regulatory network of the model genes was predicted using Cytoscape.The most valuable genes of the predic-tion model were experimentally verified by real-time quantitative polymerase chain reaction(RT-qPCR)in OA rats and normal control rats(n= 6 per group).Results One OA dataset was screened by the GEO database,and 125 OA-related SASP genes were isolated.A total of seven intersection genes were obtained by the three machine learning algorithms.The area under the curve of the prediction model was 0.891.The CIBERSORT immune infiltration results showed a significant difference in plasma cell infiltration level between OA and normal samples(P= 0.001 3).The RT-qPCR results showed that the expression level of TNFRSF1Awas significantly higher in the OA versus normal group(P<0.0001).Conclusion TNFRSF1Ais highly expressed in OA and may be a potential predictive marker for it.

Indolylarylsulfones (IASs) are classical HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs) with a unique scaffold and possess potent antiviral activity. To address the high cytotoxicity and improve safety profiles of IASs, we introduced various sulfonamide groups linked by alkyl diamine chain to explore the entrance channel of non-nucleoside inhibitors binding pocket. 48 compounds were designed and synthesized to evaluate their anti-HIV-1 activities and reverse transcriptase inhibition activities. Especially, compound R₁₀L₄ was endowed with significant inhibitory activity towards wild-type HIV-1 (EC_50(WT) = 0.007 μmol/L, SI = 30,930) as well as a panel of single-mutant strains exemplified by L100I (EC₅₀ = 0.017 μmol/L, SI = 13,055), E138K (EC₅₀ = 0.017 μmol/L, SI = 13,123) and Y181C (EC₅₀ = 0.045 μmol/L, SI = 4753) which were superior to Nevirapine and Etravirine. Notably, R₁₀L₄ was characterized with significantly reduced cytotoxicity (CC₅₀ = 216.51 μmol/L) and showed no remarkable in vivo toxic effects (acute and subacute toxicity). Moreover, the computer-based docking study was also employed to characterize the binding mode between R₁₀L₄ and HIV-1 RT. Additionally, R₁₀L₄ presented an acceptable pharmacokinetic profile. Collectively, these results deliver precious insights for next optimization and indicate that the sulfonamide IAS derivatives are promising NNRTIs for further development.

Novel therapies are urgently needed to improve global treatment of SARS-CoV-2 infection. Herein, we briefly provide a concise report on the medicinal chemistry strategies towards the development of effective SARS-CoV-2 inhibitors with representative examples in different strategies from the medicinal chemistry perspective.

BACKGROUND: Immune checkpoint inhibitor monotherapy is reported to have little effect in advanced non-small cell lung cancer (NSCLC) patients with driver oncogenes. However, recent studies have shown that some patients with driver genes are still benefit from combination immunotherapy after tyrosine kinase inhibitors (TKIs) drug resistance. The purpose of this study was to analyze the efficacy of posterior line immunotherapy in NSCLC patients with epidermal growth factor (EGFR) sensitive mutation, and to evaluate the value of immunotherapy in posterior line therapy in patients with advanced EGFR mutation. METHODS: A total of 27 patients with EGFR mutation diagnosed in Beijing Chest Hospital, Capital Medical University from June 2018 to November 2020 were collected. After the progress of targeted therapy, they had received programmed cell death protein 1 (PD-1) checkpoint inhibitor combined with chemotherapy and anti-angiogenic drug therapy. RESULTS: Of the 27 advanced NSCLC patients, 19 cases (70.4%) did not have T790M mutation. There were 8 cases (29.6%) with T790M point mutation. The total objective response rate (ORR) was 40.7%. Kaplan-Meier survival analysis showed that there was no statistically significant difference among different EGFR mutations (χ²=4.15, P=0.230). But progression-free survival (PFS) was significantly longer in patients without T790M mutation than in patients with T790M mutation (9.2 mon vs 3.3 mon, χ²=2.808, P=0.041), and the same trend was observed in patients with overall survival treated with the PD-1 inhibitor (12.2 mon vs 7.3 mon, χ²=3.22, P=0.062). ORR of patients without T790M was significantly better than that with T790M (52.63% vs 12.5%, P=0.045). CONCLUSIONS Patients with EGFR mutation can benefit from later-line combined immunotherapy. The patients with T790M mutation in the population of EGFR mutation had the worst effect of immunotherapy in the later line. Therefore, the follow-up treatment and whole-course management of these patients need to explore better treatment strategies to improve the benefit.