The rapid emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants that evade immunity elicited by vaccination has posed a global challenge to the control of the coronavirus disease 2019 (COVID-19) pandemic. Therefore, developing countermeasures that broadly protect against SARS-CoV-2 and related sarbecoviruses is essential. Herein, we have developed a lipid nanoparticle (LNP)-encapsulated mRNA (mRNA-LNP) encoding the full-length Spike (S) glycoprotein of SARS-CoV-2 (termed RG001), which confers complete protection in a non-human primate model. Intramuscular immunization of two doses of RG001 in Rhesus monkey elicited robust neutralizing antibodies and cellular response against SARS-CoV-2 variants, resulting in significantly protected SARS-CoV-2-infected animals from acute lung lesions and complete inhibition of viral replication in all animals immunized with low or high doses of RG001. More importantly, the third dose of RG001 vaccination elicited effective neutralizing antibodies against current epidemic XBB and JN.1 strains and similar cellular response against SARS-CoV-2 Omicron variants (BA.1, XBB.1.16, and JN.1) were observed in immunized mice. All these results together strongly support the great potential of RG001 in preventing the infection of SARS-CoV-2 variants of concern (VOCs).

Coronaviruses of the genus Coronavirus contain a variety of human pathogenic viruses, and the development of anti-coronavirus drugs is of great value. The development of antiviral drugs targeting host cells is not only helpful for the development of new antiviral strategies, but also for solving problems such as drug resistance due to viral mutations. Our preliminary study identified that cell cycle-dependent protein kinases (CDKs) involved in coronavirus replication, for which they would be potential anticoronaviral targets. In this study, we found that the broad-spectrum CDK inhibitor flavopiridol significantly inhibited severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA dependent RNA polymerase (RdRp) activity. Further studies showed that flavopiridol suppressed the RNA synthesis efficiency of SARS-CoV-2 RdRp. In addition, flavopiridol effectively restricted the replication of human coronavirus OC43 (HCoV-OC43). Therefore, our study suggested that the CDK inhibitor flavopiridol may be a potential anticoronaviral drug.

Objective:To analyze the methylation characteristics of the lymphocyte-specific protein-tyrosine kinase (LCK) promoter region in the peripheral blood circulation of rheumatoid arthritis (RA) patients and its correlation with clinical indicators.Methods:Targeted methylation sequencing was used to compare the methylation levels of 7 CpG sites in the LCK promoter region in the peripheral blood of RA patients with healthy controls (HC) and osteoarthritis (OA) patients. Correlation analysis and ROC curve construction were performed with clinical information.Results:Non-parametric tests revealed that compared with HC [0.53(0.50, 0.57)] and OA patients [0.59(0.54, 0.62), H=47.17, P<0.001], RA patients [0.63(0.59, 0.68)] exhibited an overall increase in methylation levels. Simultaneously, when compared with the HC group [0.38(0.35, 0.41), 0.59(0.55, 0.63), 0.60(0.55, 0.64), 0.59(0.55, 0.63), 0.58(0.53, 0.62), 0.45(0.43, 0.49), 0.57(0.54, 0.61)], the RA group [0.46(0.42, 0.49), 0.70(0.65, 0.75), 0.70(0.66, 0.76), 0.70(0.65, 0.75), 0.69(0.64, 0.74), 0.55(0.51, 0.59), 0.68(0.63, 0.73)] showed a significant elevation in methylation levels at CpG sites cg05350315_60, cg05350315_80, cg05350315_95, cg05350315_101, cg05350315_104, cg05350315_128, and cg05350315_142, with statistically significant differences ( Z=-5.63, -5.89, -5.91, -5.89, -5.98, -5.95, -5.95, all P<0.001). Compared with the OA group [0.65(0.59, 0.69), 0.65(0.60, 0.69), 0.64(0.58, 0.68), 0.50(0.45, 0.54), 0.63(0.58, 0.67)], the RA group [0.70(0.66, 0.76), 0.70(0.65, 0.75), 0.69(0.64, 0.74), 0.55(0.51, 0.59), 0.68(0.63, 0.73)] exhibited a significant increase in methylation levels at CpG sites cg05350315_95, cg05350315_101, cg05350315_104, cg05350315_128, and cg05350315_142, with statistically significant differences ( Z=-3.56, -3.52, -3.60, -3.67, -3.62; P=0.036, 0.042, 0.031, 0.030, 0.030). Furthermore, Pearson correlation coefficient analysis revealed a positive correlation between the overall methylation level in this region and C-reactive protein (CRP) ( r=0.19, P=0.004) and erythrocyte sedimentation rate ( r=0.14, P=0.035). The overall methylation level of the LCK promoter region in the CRP (low) group [0.63 (0.58, 0.68)] was higher than that in the CRP (high) group [0.65(0.61, 0.70)], with statistically significant differences ( Z=2.60, P=0.009). Finally, by constru-cting a ROC curve, the discriminatory efficacy of peripheral blood LCK promoter region methylation levels for identifying RA patients, especially seronegative RA patients, from HC and OA groups was validated, with an AUC value of 0.78 (95% CI: 0.63, 0.93). Conclusion:This study provides insights into the methylation status and methylation haplotype patterns of the LCK promoter region in the peripheral blood of RA patients. The overall methylation level in this region is positively correlated with the level of inflammation and can be used to differentiate seronegative RA patients from the HC and OA patients.

The interaction between Mycobacterium tuberculosis and host, as well as the regulation of some signaling pathways in the host, were involved in pathogen latency in macrophages. microRNAs (miRNAs) regulate the gene expression and biological functions, indicating that miRNAs played a regulatory role in bacterial infections. However, whether the host's miRNAs were also involved in the process of Mycobacterium tuberculosis infection had not been thoroughly studied. This study infected macrophages with pathogenic Mycobacterium tuberculosis strain H37Rv and low virulence strain H37Ra to explore the functional miRNAs. By identifying the expression profile of miRNAs in host cells after infection, the expression of 17 miRNAs significantly changed (P < 0.05) in the human macrophage THP-1 infected with highly pathogenic H37Rv strain (Rv), H37Rv inactivated strain (Rv-), and non-pathogenic H37Ra (Ra) strains respectively, indicating that host miRNAs may be involved in the interaction of Mycobacterium tuberculosis and host. Meanwhile, 10 types of miRNAs showed significant differences in cells infected with pathogenic and non-pathogenic Mycobacterium tuberculosis, suggesting that host miRNAs may play an important role in the pathogenicity and intracellular survival of Mycobacterium tuberculosis. Further study had found that miR-449a, miR-502-5p, and miR-708 were downregulated in cells infected with Mycobacterium marinum. Overexpression of these three miRNAs displayed the significant inhibitory effect on the growth of Mycobacterium marinum, indicating that miRNAs played a pivotal role in the interaction between the host and Mycobacterium marinum. This study provided the new insights into the pathogenesis of Mycobacterium tuberculosis and the treatment of tuberculosis.

Oxalicine B ( 1) is an α-pyrone meroterpenoid with a unique bispirocyclic ring system derived from Penicillium oxalicum. The biosynthetic pathway of 15-deoxyoxalicine B ( 4) was preliminarily reported in Penicillium canescens, however, the genetic base and biochemical characterization of tailoring reactions for oxalicine B ( 1) has remained enigmatic. In this study, we characterized three oxygenases from the metabolic pathway of oxalicine B ( 1), including a cytochrome P450 hydroxylase OxaL, a hydroxylating Fe(II)/α-KG-dependent dioxygenase OxaK, and a multifunctional cytochrome P450 OxaB. Intriguingly, OxaK can catalyze various multicyclic intermediates or shunt products of oxalicines with impressive substrate promiscuity. OxaB was further proven via biochemical assays to have the ability to convert 15-hydroxdecaturin A ( 3) to 1 with a spiro-lactone core skeleton through oxidative rearrangement. We also solved the mystery of OxaL that controls C-15 hydroxylation. Chemical investigation of the wild-type strain and deletants enabled us to identify 10 metabolites including three new compounds, and the isolated compounds displayed potent anti-influenza A virus bioactivities exhibiting IC₅₀ values in the range of 4.0-19.9 μmol/L. Our studies have allowed us to propose a late-stage biosynthetic pathway for oxalicine B ( 1) and create downstream derivatizations of oxalicines by employing enzymatic strategies.

Investigation on how nature produces natural compounds with chemical and biological diversity at the genetic level offers inspiration for the discovery of new natural products and even their biological targets. The polyketide rumbrin ( 1) is a lipid peroxide production and calcium accumulation inhibitor, which contains a chlorinated pyrrole moiety that is a rare chemical feature in fungal natural products. Here, we identify the biosynthetic gene cluster (BGC) rum of 1 and its isomer 12E-rumbrin ( 2) from Auxarthron umbrinum DSM3193, and elucidate their biosynthetic pathway based on heterologous expression, chemical complementation, and isotopic labeling. We show that rumbrins are assembled by a highly reducing polyketide synthase (HRPKS) that uniquely incorporates a proline-derived pyrrolyl-CoA starer unit, and followed by methylation and chlorination. Sequent precursor-directed biosynthesis was able to yield a group of rumbrin analogues. Remarkably, inspired by the presence of a human immunodeficiency virus (HIV)-Nef-associated gene in the rum cluster, we predicted and pharmacologically demonstrated rumbrins as potent inhibitors of HIV at the nanomolar level. This work enriches the recognition of unconventional starter units of fungal PKSs and provides a new strategy for genome mining-guided drug discovery.

Norovirus (NoV) belongs to the genus Norovirus of the family Cupaviridae, which is the main pathogen causing non-bacterial acute and sporadic gastroenteritis. Treatments for NoV infections primarily focus on antiviral drugs designed to target various aspects of NoV replication, host cytokines, and immunomodulatory factors. This review highlights anti-NoV drugs with the aim of providing new ideas for the prevention and treatment of NoV.

Chaperone-mediated autophagy (CMA) is a lysosome-dependent selective degradation pathway implicated in the pathogenesis of cancer and neurodegenerative diseases. However, the mechanisms that regulate CMA are not fully understood. Here, using unbiased drug screening approaches, we discover Metformin, a drug that is commonly the first medication prescribed for type 2 diabetes, can induce CMA. We delineate the mechanism of CMA induction by Metformin to be via activation of TAK1-IKKα/β signaling that leads to phosphorylation of Ser85 of the key mediator of CMA, Hsc70, and its activation. Notably, we find that amyloid-beta precursor protein (APP) is a CMA substrate and that it binds to Hsc70 in an IKKα/β-dependent manner. The inhibition of CMA-mediated degradation of APP enhances its cytotoxicity. Importantly, we find that in the APP/PS1 mouse model of Alzheimer's disease (AD), activation of CMA by Hsc70 overexpression or Metformin potently reduces the accumulated brain Aβ plaque levels and reverses the molecular and behavioral AD phenotypes. Our study elucidates a novel mechanism of CMA regulation via Metformin-TAK1-IKKα/β-Hsc70 signaling and suggests Metformin as a new activator of CMA for diseases, such as AD, where such therapeutic intervention could be beneficial.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has become one major threat to human population health. The RNA-dependent RNA polymerase (RdRp) presents an ideal target of antivirals, whereas nucleoside analogs inhibitor is hindered by the proofreading activity of coronavirus. Herein, we report that corilagin (RAI-S-37) as a non-nucleoside inhibitor of SARS-CoV-2 RdRp, binds directly to RdRp, effectively inhibits the polymerase activity in both cell-free and cell-based assays, fully resists the proofreading activity and potently inhibits SARS-CoV-2 infection with a low 50% effective concentration (EC