Methyl rosmarinate is an allosteric inhibitor of SARS-CoV-2 3 CL protease as a potential candidate against SARS-cov-2 infection.

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been ongoing for more than three years and urgently needs to be addressed. Traditional Chinese medicine (TCM) prescriptions have played an important role in the clinical treatment of patients with COVID-19 in China. However, it is difficult to uncover the potential molecular mechanisms of the active ingredients in these TCM prescriptions. In this paper, we developed a new approach by integrating the experimental assay, virtual screening, and the experimental verification, exploring the rapid discovery of active ingredients from TCM prescriptions. To achieve this goal, 4 TCM prescriptions in clinical use for different indications were selected to find the antiviral active ingredients in TCMs. The 3-chymotrypsin-like protease (3CLpro), an important target for fighting COVID-19, was utilized to determine the inhibitory activity of the TCM prescriptions and single herb. It was found that 10 single herbs had better inhibitory activity than other herbs by using a fluorescence resonance energy transfer (FRET) - based enzymatic assay of SARS-CoV-2 3CLpro. The ingredients contained in 10 herbs were thus virtually screened and the predicted active ingredients were experimentally validated. Thus, such a research strategy firstly removed many single herbs with no inhibitory activity against SARS-CoV-2 3CLpro at the very beginning by FRET-based assay, making our subsequent virtual screening more effective. Finally, 4 active components were found to have stronger inhibitory effects on SARS-CoV-2 3CLpro, and their inhibitory mechanism was subsequently investigated. Among of them, methyl rosmarinate as an allosteric inhibitor of SARS-CoV-2 3CLpro was confirmed and its ability to inhibit viral replication was demonstrated by the SARS-CoV-2 replicon system. To validate the binding mode via docking, the mutation experiment, circular dichroism (CD), enzymatic inhibition and surface plasmon resonance (SPR) assay were performed, demonstrating that methyl rosmarinate bound to the allosteric site of SARS-CoV-2 3CLpro. In conclusion, this paper provides the new ideas for the rapid discovery of active ingredients in TCM prescriptions based on a specific target, and methyl rosmarinate has the potential to be developed as an antiviral therapeutic candidate against SARS-CoV-2 infection.

The yin-yang effects of immunity: From monoclonal gammopathy of undetermined significance to multiple myeloma.

Multiple myeloma (MM) is the third most common malignant neoplasm of the hematological system. It often develops from monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM) precursor states. In this process, the immune microenvironment interacts with the MM cells to exert yin and yang effects, promoting tumor progression on the one hand and inhibiting it on the other. Despite significant therapeutic advances, MM remains incurable, and the main reason for this may be related to the complex and variable immune microenvironment. Therefore, it is crucial to investigate the dynamic relationship between the immune microenvironment and tumors, to elucidate the molecular mechanisms of different factors in the microenvironment, and to develop novel therapeutic agents targeting the immune microenvironment of MM. In this paper, we review the latest research progress and describe the dual influences of the immune microenvironment on the development and progression of MM from the perspective of immune cells and molecules.

Long-term functional maintenance of primary human hepatocytes in vitro.

The maintenance of terminally differentiated cells, especially hepatocytes, in vitro has proven challenging. Here we demonstrated the long-term in vitro maintenance of primary human hepatocytes (PHHs) by modulating cell signaling pathways with a combination of five chemicals (5C). 5C-cultured PHHs showed global gene expression profiles and hepatocyte-specific functions resembling those of freshly isolated counterparts. Furthermore, these cells efficiently recapitulated the entire course of hepatitis B virus (HBV) infection over 4 weeks with the production of infectious viral particles and formation of HBV covalently closed circular DNA. Our study demonstrates that, with a chemical approach, functional maintenance of PHHs supports long-term HBV infection in vitro, providing an efficient platform for investigating HBV cell biology and antiviral drug screening.

Effect of different struvite crystallization methods on gaseous emission and the comprehensive comparison during the composting.

This study compared 4 different struvite crystallization process (SCP) during the composting of pig feces. Four combinations of magnesium and phosphate salts (H3PO4+MgO (PMO), KH2PO4+MgSO4 (KPM), Ca(H2PO4)2+MgSO4 (CaPM), H3PO4+MgSO4 (PMS)) were assessed and were also compared to a control group (CK) without additives. The magnesium and phosphate salts were all supplemented at a level equivalent to 15% of the initial nitrogen content on a molar basis. The SCP significantly reduced NH3 emission by 50.7-81.8%, but not the N2O. Although PMS group had the lowest NH3 emission rate, the PMO treatment had the highest struvite content in the end product. The addition of sulphate decreased CH4 emission by 60.8-74.6%. The CaPM treatment significantly decreased NH3 (59.2%) and CH4 (64.9%) emission and yielded compost that was completely matured. Due to its effective performance and low cost, the CaPM was suggested to be used in practice.

Distribution of α-, ß-, γ-, and δ-hexachlorocyclohexane in soil-plant-air system in a tea garden.

The residue of hexachlorocyclohexane (HCH) isomers (mainly α-, ß-, γ-, and δ-HCH) in the soils, plant tissues and atmosphere were measured in a typical tea garden in Fujian, a major tea-producing province in China, and this study focused on the distribution and accumulation of HCHs. HCHs could accumulate in most of the plant tissues, with the highest HCH concentration of 3.0±2.9ng/g dw in old leaves. Uptake of HCHs by the roots from soil was the possible pathway for HCHs accumulation in plants, and the accumulation was an isomer-selective process, with the highest concentration factor of 10.3 for α-HCH. The higher percentages of α- and γ-HCH in roots (28.1 percent and 43.7 percent) than those in soil (14.0% and 34.1 percent) also implied the isomer-selective accumulation of HCHs. ΣHCHs in the gaseous phase (157±97pg/m(3)) were significantly higher than those in particle phase (19±20pg/m(3)). Volatilization of HCHs from soils and uptake by the plant's aerial tissues might be the pathway for HCHs accumulation in leaves and stems, and ß-HCH showed the highest accumulation capacity in young leaves. The percentage distribution pattern of the dust on plant leaves were similar to that in soils, suggesting that the dust on the leaves were mainly from the soils. High γ-HCH concentrations and low α-/γ-HCH ratios in plant's aerial tissues suggested the input of lindane in tea garden.