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Test anxiety (TA) is a common emotion among students during examinations. Test‐induced stress can remarkably impact students' emotions and limit their performance. Mental stress is a crucial factor that could significantly alter gut microbial composition, but rare reports focus on the correlation between TA and oral microbial composition. This study aims to investigate the impact of TA on students' oral microbiota composition. This study targeted medical students who usually face heavier workloads than average undergraduates. 28 females and 19 males aged 18–30 were enrolled in this study. Questionnaires and saliva samples were collected from the participants before, during, and after the end‐term examination. The level of anxiety was classified as normal, mild, moderate, and severe based on the questionnaire scores. In addition, 16S amplicon sequencing was used to analyse the composition of oral microbes. More than half of the students faced different levels of TA before and after the examination. Over three‐quarters of students showed anxiety during the examination, and a quarter suffered severe TA. The 16S sequencing data showed that TA significantly altered the oral microbial composition between students with and without TA in all three survey periods. Moreover, during the examination, the genera Rothia and Streptococcus, the oral‐beneficial bacteria, markedly decreased in students with TA. On the other hand, the potential pathogenic genera, such as Prevotella, Fusobacterium, and Haemophilus, significantly increased in the students with TA. And the TA effect on oral microbes displayed a gender difference among students. A high ratio of TA existed in the students during their examination period, and TA could significantly alter the oral microbial composition, decrease beneficial microbes, and promote potential pathogenic oral microbes. [ABSTRACT FROM AUTHOR]

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by complex pathogenesis mechanisms. Among these, β‐amyloid plaques and hyperphosphorylated Tau protein tangles have been identified as significant contributors to neuronal damage. This study investigates thonningianin A (TA) from Penthorum chinense Pursh (PCP) as a potential inhibitor targeting these pivotal proteins in AD progression. The inhibitory potential of PCP and TA on Aβ fibrillization was initially investigated. Subsequently, ultra‐high performance liquid chromatography‐quadrupole time‐of‐flight tandem mass spectrometry and biolayer interferometry were employed to determine TA's affinity for both Aβ and Tau. The inhibitory effects of TA on the levels and cytotoxicity of AD‐related proteins were then assessed. In 3xTg‐AD mice, the therapeutic potential of TA was evaluated. Additionally, the molecular interactions between TA and either Aβ or Tau were explored using molecular docking. We found that PCP‐total ethanol extract and TA significantly inhibited Aβ fibrillization. Additionally, TA demonstrated strong affinity to Aβ and Tau, reduced levels of amyloid precursor protein and Tau, and alleviated mitochondrial distress in PC‐12 cells. In 3xTg‐AD mice, TA improved cognition, reduced Aβ and Tau pathology, and strengthened neurons. Moreover, molecular analyses revealed efficient binding of TA to Aβ and Tau. In conclusion, TA, derived from PCP, shows significant neuroprotection against AD proteins, highlighting its potential as an anti‐AD drug candidate. [ABSTRACT FROM AUTHOR]

Chronic hepatitis B virus (HBV) infection remains a significant global health challenge due to its link to severe conditions like HBV‐related cirrhosis and hepatocellular carcinoma (HCC). Although current treatments effectively reduce viral levels, they have limited impact on certain HBV elements, namely hepatitis B surface antigen (HBsAg) and covalently closed circular DNA (cccDNA). This highlights the urgent need for innovative pharmaceutical and biological interventions that can disrupt HBsAg production originating from cccDNA. In this study, we identified a natural furanocoumarin compound, Imperatorin, which markedly inhibited the expression of HBsAg from cccDNA, by screening a library of natural compounds derived from Chinese herbal medicines using ELISA assay and qRT‐PCR. The pharmacodynamics study of Imperatorin was explored on HBV infected HepG2‐NTCP/PHHs and HBV‐infected humanized mouse model. Proteome analysis was performed on HBV infected HepG2‐NTCP cells following Imperatorin treatment. Molecular docking and bio‐layer interferometry (BLI) were used for finding the target of Imperatorin. Our findings demonstrated Imperatorin remarkably reduced the level of HBsAg, HBV RNAs, HBV DNA and transcriptional activity of cccDNA both in vitro and in vivo. Additionally, Imperatorin effectively restrained the actions of HBV promoters responsible for cccDNA transcription. Mechanistic study revealed that Imperatorin directly binds to ERK and subsequently interfering with the activation of CAMP response element‐binding protein (CREB), a crucial transcriptional factor for HBV and has been demonstrated to bind to the PreS2/S and X promoter regions of HBV. Importantly, the absence of ERK could nullify the antiviral impact triggered by Imperatorin. Collectively, the natural compound Imperatorin may be an effective candidate agent for inhibiting HBsAg production and cccDNA transcription by impeding the activities of HBV promoters through ERK‐CREB axis. [ABSTRACT FROM AUTHOR]

The development of inhibitors that target the papain‐like protease (PLpro) has the potential to counteract the spread of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), the agent causing coronavirus disease 2019 (COVID‐19). Based on a consideration of its several downstream effects, interfering with PLpro would both revert immune suppression exerted by the virus and inhibit viral replication. By following a repurposing strategy, the current study evaluates the potential of antimalarial drugs as PLpro inhibitors, and thereby the possibility of their use for treatment of SARS‐CoV‐2 infection. Computational tools were employed for structural analysis, molecular docking, and molecular dynamics simulations to screen antimalarial drugs against PLpro, and in silico data were validated by in vitro experiments. Virtual screening highlighted amodiaquine and methylene blue as the best candidates, and these findings were complemented by the in vitro results that indicated amodiaquine as a μM PLpro deubiquitinase inhibitor. The results of this study demonstrate that the computational workflow adopted here can correctly identify active compounds. Thus, the highlighted antimalarial drugs represent a starting point for the development of new PLpro inhibitors through structural optimization. [ABSTRACT FROM AUTHOR]

Blockade of immune checkpoints as a strategy of cancer cells to overcome the immune response has received ample attention in cancer research recently. In particular, expression of PD‐L1 by various cancer cells has become a paradigm in this respect. Delivery of PD‐L1 to its site of action occurs either by local diffusion, or else by transport via small extracellular vesicles (sEVs, commonly referred to as exosomes). Many steps of sEVs formation, their packaging with PD‐L1 and their release into the extracellular space have been studied in detail. The likely dependence of release on Ca2+‐signaling, however, has received little attention. This is surprising, since the intracellular Ca2+‐concentration is known as a prominent regulator of many secretory processes. Here, we report on the roles of three Ca2+‐dependent proteins in regulating release of PD‐L1‐containing sEVs, as well as on the growth of tumors in mouse models. We show that sEVs release in cancer cell lines is Ca2+‐dependent and the knockdown of the gene coding the Ca2+‐channel protein ORAI1 reduces Ca2+‐signals and release of sEVs. Consequently, the T cell response is reinvigorated and tumor progression in mouse models is retarded. Furthermore, analysis of protein expression patterns in samples from human cancer tissue shows that the ORAI1 gene is significantly upregulated. Such upregulation is identified as an unfavorable prognostic factor for survival of patients with non‐small‐cell lung cancer. We show that reduced Ca2+‐signaling after knockdown of ORAI1 gene also compromises the activity of melanophilin and Synaptotagmin‐like protein 2, two proteins, which are important for correct localization of secretory organelles within cancer cells and their transport to sites of exocytosis. Thus, the Ca2+‐channel ORAI1 and Ca2+‐dependent proteins of the secretion pathway emerge as important targets for understanding and manipulating immune checkpoint blockade by PD‐L1. [ABSTRACT FROM AUTHOR]

Background and Purpose: Celastrol exhibits anti-arthritic effects in rheumatoid arthritis (RA), but the role of celastrol-mediated Ca2+ mobilization in treatment of RA remains undefined. Here, we describe a regulatory role for celastrol-induced Ca2+ signalling in synovial fibroblasts of RA patients and adjuvant-induced arthritis (AIA) in rats.Experimental Approach: We used computational docking, Ca2+ dynamics and functional assays to study the sarcoplasmic/endoplasmic reticulum Ca2+ ATPase pump (SERCA). In rheumatoid arthritis synovial fibroblasts (RASFs)/rheumatoid arthritis fibroblast-like synoviocytes (RAFLS), mechanisms of Ca2+ -mediated autophagy were analysed by histological, immunohistochemical and flow cytometric techniques. Anti-arthritic effects of celastrol, autophagy induction, and growth rate of synovial fibroblasts in AIA rats were monitored by microCT and immunofluorescence staining. mRNA from joint tissues of AIA rats was isolated for transcriptional analysis of inflammatory genes, using siRNA methods to study calmodulin, calpains, and calcineurin.Key Results: Celastrol inhibited SERCA to induce autophagy-dependent cytotoxicity in RASFs/RAFLS via Ca2+ /calmodulin-dependent kinase kinase-β-AMP-activated protein kinase-mTOR pathway and repressed arthritis symptoms in AIA rats. BAPTA/AM hampered the in vitro and in vivo effectiveness of celastrol. Inflammatory- and autoimmunity-associated genes down-regulated by celastrol in joint tissues of AIA rat were restored by BAPTA/AM. Knockdown of calmodulin, calpains, and calcineurin in RAFLS confirmed the role of Ca2+ in celastrol-regulated gene expression.Conclusion and Implications: Celastrol triggered Ca2+ signalling to induce autophagic cell death in RASFs/RAFLS and ameliorated arthritis in AIA rats mediated by calcium-dependent/-binding proteins facilitating the exploitation of anti-arthritic drugs based on manipulation of Ca2+ signalling. [ABSTRACT FROM AUTHOR]

Abstract: Lysine‐specific demethylase 5A (KDM5A) has recently become a promising target for epigenetic therapy. In this study, we designed and synthesized metal complexes bearing ligands with reported demethylase and p27 modulating activities. The Rh(III) complex 1 was identified as a direct, selective and potent inhibitor of KDM5A that directly abrogate KDM5A demethylase activity via antagonizing the KDM5A‐tri‐/di‐methylated histone 3 protein–protein interaction (PPI) in vitro and in cellulo. Complex 1 induced accumulation of H3K4me3 and H3K4me2 levels in cells, causing growth arrest at G1 phase in the triple‐negative breast cancer (TNBC) cell lines, MDA‐MB‐231 and 4T1. Finally, 1 exhibited potent anti‐tumor activity against TNBC xenografts in an in vivo mouse model, presumably via targeting of KDM5A and hence upregulating p27. Moreover, complex 1 was less toxic compared with two clinical drugs, cisplatin and doxorubicin. To our knowledge, complex 1 is the first metal‐based KDM5A inhibitor reported in the literature. We anticipate that complex 1 may be used as a novel scaffold for the further development of more potent epigenetic agents against cancers, including TNBC. [ABSTRACT FROM AUTHOR]