Transmembrane serine protease 2 (TMPRSS2) is a cell surface protease widely present in the human body. It is involved in the infection of various viruses such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and in the cell invasion, tumor growth and metastasis processes of prostate cancer. This study used Boc-Gln-Ala-Arg-AMC as the fluorescent substrate to determine the cleavage activity of TMPRSS2 towards SARS-CoV-2 S protein. Then cell-based screening model for TMPRSS2 inhibitors was established in Vero E6 cells overexpressing TMPRSS2 (Vero E6/TMPRSS2). Seven compounds exhibiting TMPRSS2 inhibitory activities with low toxicity were obtained through high-throughput screening (HTS) from natural and synthetic compound pure product library of National Center for Screening Novel Microbial Drugs. Surface plasmon resonance (SPR) has shown that the obtained inhibitors could bind to TMPRSS2 with moderate affinity in a dose dependent manner. Cell-cell fusion experiments have shown that the obtained inhibitors can inhibit the occurrence of S protein mediated cell-cell fusion by inhibiting TMPRSS2 cleavage of SARS-CoV-2 S protein in a concentration dependent manner. Preliminary pseudovirus experiment showed that the inhibitors may reduce the pseudovirus infection into Opti-HEK-293T-ACE2 cells to varying degrees. In a word, this study successfully established a cell-based HTS model for TMPRSS2 inhibitor and preliminarily confirmed that the seven screened inhibitors possessed in vitro anti-TMPRSS2 activities, providing new structural scaffolds for the development of new drugs against SARS-CoV-2.

Arginase 1 deficiency (ARG1-D) is a rare genetic metabolic disorder that leads to progressive spastic paralysis, cognitive impairment, and seizures. Recombinant human arginase 1 (rhArg1) is a potential therapeutic agent for this condition, but its clinical application is limited by low activity and short half-life. In this study, we employed directed evolution to address these issues. A random mutation library of rhArg1 was constructed using error-prone PCR, and high-throughput screening was used to identify mutants with enhanced activity. Site-saturation mutagenesis was also performed to investigate the effects of residues R21 and V182 on enzyme activity. Our findings revealed that under reaction conditions devoid of Mn²⁺, the k_cat values of the mutants V182D, V182S, V182H, and R21N increased by 2.0, 1.9, 1.7, and 1.3 times respectively, compared to rhArg1. The k_cat/K_m values of mutants V182D, V182S, R21D, and R21N were 2.1, 1.7, 1.4, and 1.4 times higher than those of rhArg1, respectively. Additionally, mutants R21D and V182L showed enhanced substrate affinity. Through directed evolution and site-saturation mutagenesis, we successfully obtained rhArg1 mutants with improved activity, thereby enhancing its potential for clinical application.

Studies have shown that a variety of diseases such as cardiovascular disease, renal disease and cancer are closely related to trimethylamine oxide (TMAO). Clinically, abnormal elevation of TMAO has been used as an evaluation index of atherosclerosis (AS) prior to imaging. In this study, we investigated the effects of lipid metabolism disorders as well as pharmacological interventions on urinary TMAO using a hyperlipidemic golden gopher model. The study used 48 Syrian golden hamster modeled with a high-fat diet for 2 weeks, and then ezetimibe, simvastatin, ezetimibe and simvastatin groups were administered for 4 consecutive weeks, as well as the clinical trial drug, IMM-H007, for pharmacological intervention. The animal experiment was conducted in accordance with the regulations of the Ethics Committee for Experimental Animal Management and Animal Welfare of Institute of Materia Medica, Chinese Academy of Medical Sciences (approval number: SCXK (Beijing) 2021-0011). Urine from rats was analyzed for 2D band selective heteronuclear single quantum coherence (2D bs-HSQC) at week 2 and 4 after drug administration. The results indicated that, in comparison to the control group, the high-fat diet significantly elevated urinary TMAO levels in the model group of hamsters after both 2 and 4 weeks of treatment (P < 0.05). Urinary TMAO levels were significantly reduced (P < 0.05) in the model group after 2 or 4 weeks of intervention with ezetimibe, simvastatin, combination therapy, and IMM-H007, showing a marked decrease even after 2 weeks of treatment. The detection of TMAO could precede the measurement of serum biochemical indicators, facilitating earlier efficacy assessment. This study evaluated the modulatory effects of clinical drugs and clinical trial drugs on TMAO, which provides useful information for clinical drug use and drug research. It also provides a means of TMAO detection based on 2D NMR technology, which is helpful for the clinical application of TMAO detection index.

Liver size is regulated by circadian clock and exhibits a diurnal rhythm. Pregnane X receptor (PXR) and peroxisome proliferator-activated receptor α (PPARα), members of nuclear receptor superfamily, are important regulators of liver size. We previously demonstrated that mPXR agonist pregnenolone 16α-carbonitrile (PCN) and mPPARα agonist pirinixic acid (WY-14643) promoted liver enlargement and liver regeneration after partial hepatectomy. However, whether PXR or PPARα activation-induced liver enlargement exhibits diurnal rhythm with normal liver diurnal oscillations remains unclear. The aim of this study was to investigate the diurnal rhythm of PXR or PPARα activation-induced liver enlargement. Male C57BL/6 mice were intraperitoneally injected with corn oil, PCN or WY-14643 for three days, and liver samples were weighed and collected at various time points for analysis. The animal experiment protocol was reviewed and approved by Institutional Animal Care and Use Committee of Sun Yat-sen University (approval No. SYSU-IACUC-2023-001613, SYSU-IACUC-2023-001783). The results showed that PXR or PPARα activation at various time points significantly induced liver enlargement, and liver size maintained normal diurnal oscillations during PXR or PPARα activation-induced hepatomegaly, without significant effects on the expression of core clock genes. This study reveals PXR or PPARα activation-induced liver enlargement exhibits diurnal rhythm with normal liver diurnal oscillations, and provides novel data for nuclear receptor-induced liver enlargement and liver diurnal rhythm.

Gut microbiome and their metabolites are closely related to human diseases, which influence the development of diseases by interacting with receptors. G protein-coupled receptor (GPCR) is a receptor superfamily that exists on the surface of cell membrane, which is involved in a wide range of human physiological activities. GPCR is currently considered as important drug targets. Traditional Chinese medicines (TCM) are characterized by multi-components, multi-targets, and multi-pathways. More and more studies have demonstrated that TCM can ultimately intervene in diseases by modulating gut microbiome and their metabolites, affecting their interactions with GPCR. This review discusses the status of gut microbiome and human diseases, the interactions of gut microbiome and their metabolites with GPCR, and the status of GPCR drug development. Based on the above contents, a new model of "TCM-gut microbiome panel-GPCR-disease" is proposed. The interactions between active ingredients of TCM, gut microbiome panel, and GPCR and their effects on disease are elucidated through multi-omics techniques. This review will provide new ideas for analyzing the pharmacological mechanism of TCM efficacy and searching for new targets of TCM.

Heat shock protein 90 (HSP90) is a crucial molecular chaperone responsible for the activation and maturation of client proteins. Targeting HSP90 can effectively inhibit cancer cell proliferation by either competitively occupying the ATP-binding site or disrupting the protein-protein interaction sites between HSP90 and its co-chaperones. Therefore, studying the recognition and function of HSP90 binding sites is essential for molecular discovery. This study focuses on peptide P1, revealing its dual binding mechanism with HSP90. P1 is capable of simultaneously interacting with both the ATP-binding site of HSP90 and the binding interface with the co-chaperone CDC37 (cell division cycle 37). Through ATPase and Co-IP assays, we found that P1 effectively inhibits both ATP activity and the protein interaction between HSP90 and CDC37, providing a novel approach for developing new inhibitors targeting the HSP90 chaperone system.

Folding and post-translational modification of proteins are vital for their proper functionality, with various functional regulatory systems playing significant roles, including molecular chaperone systems, ubiquitination systems, phosphorylation systems, acetylation systems, etc. Precise regulations of these systems have emerged as an important trend in drug development. This review systematically summarizes the molecular control strategies related to protein folding and post-translational modification, with a specific focus on the molecular chaperone system and the strategy of heterobifunctional molecules. On one hand, based on the similarities and differences in molecular mechanisms and design strategies, we summarize the drug development process targeting the molecular chaperone system. On the other hand, we discuss the design principles and characteristics of dual-functional molecules, and summarize their applications and developments in the precise control of post-translational modifications, aiming to provide new insights for future design.

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that regulates gene expression in a range of cells, including immune and epithelial cells. AhR signaling plays important roles in the immune system in both health and disease states. Tapinarof is a first-in-class small-molecule topical therapeutic AhR modulating agent launched for the treatment of psoriasis. To improve the activity and chemical stability of Tapinarof, a series of 2-phenylchromen-4-one derivatives were designed, synthesized and evaluated as novel AhR agonists. Compounds 5a, 5c, 5e and 5f potently activated AhR with an EC₅₀ value of 7, 9, 6 and 6 nmol·L^-1, respectively, which are 10-14 fold more potent than Tapinarof. Compounds 5a and 5e exhibit comparable inhibitory effects on IFN-γ production as Tapinarof. Furthermore, compounds 5a-5f exhibited favorable photochemical stability compared to Tapinarof. The compounds may eventually serve as lead compounds for the development of new AhR agonists.

The gut microbiota plays a crucial role in the development of colorectal cancer (CRC). The imbalanced gut microbiota causes damage to the body and disrupts bile acids metabolism, increases susceptibility to CRC, and affects the signaling of farnesol X receptor (FXR), thereby promoting CRC progression. Traditional Chinese medicine has unique advantages in the treatment of CRC due to its synergistic regulatory effects of multiple components, targets, and pathways. It can regulate gut microbiota, intervene in bile acids metabolism, and activate its receptor FXR to inhibit the occurrence and development of CRC. Based on this, this article discusses the main role of the gut microbiota-bile acids-FXR axis in the development of CRC, and reviews the anti CRC effects and mechanisms of traditional Chinese medicine intervention on gut microbiota-bile acids-FXR axis, in order to provide new ideas and methods for the prevention and treatment of CRC.

The non-alkaloid chemical constituents of dried Phellodendron chinense barks were investigated. A total of 14 phenolic compounds (1-14) were isolated from the 95% ethanol extract of Phellodendron chinense by the utilization of silica gel, medium pressure liquid chromatography, Sephadex LH-20 column chromatography, and preparative liquid chromatography. Among of the isolated compounds, isophellolactone (1) was identified as a new compound. The isolated 14 compounds were further tested the activity on α-glucosidase inhibition. The results for the first time demonstrated that quininic acid ester 3-6 and 8 exhibited good α-glucosidase inhibitory activity. Polyhydroxy hexa-membered carbon ring in quinine ester derivatives is possibly the essential group for the α-glucosidase inhibitory activity.