Glutamine synthetase regulates the immune microenvironment and cancer development through the inflammatory pathway.

Although adjuvant tamoxifen therapy is beneficial to estrogen receptor-positive (ER+) breast cancer patients, a significant number of patients still develop metastasis or undergo recurrence. Therefore, identifying novel diagnostic and prognostic biomarkers for these patients is urgently needed. Predictive markers and therapeutic strategies for tamoxifen-resistant ER+ breast cancer are not clear, and micro (mi)RNAs have recently become a focal research point in cancer studies owing to their regulation of gene expressions, metabolism, and many other physiological processes. Therefore, systematic investigation is required to understand the modulation of gene expression in tamoxifen-resistant patients. High-throughput technology uses a holistic approach to observe differences among expression profiles of thousands of genes, which provides a comprehensive level to extensively investigate functional genomics and biological processes. Through a bioinformatics analysis, we revealed that glutamine synthetase/glutamate-ammonia ligase (GLUL) might play essential roles in the recurrence of tamoxifen-resistant ER+ patients. GLUL increases intracellular glutamine usage via glutaminolysis, and further active metabolism-related downstream molecules in cancer cell. However, how GLUL regulates the tumor microenvironment for tamoxifen-resistant ER+ breast cancer remains unexplored. Analysis of MetaCore pathway database demonstrated that GLUL is involved in the cell cycle, immune response, interleukin (IL)-4-induced regulators of cell growth, differentiation, and metabolism-related pathways. Experimental data also confirmed that the knockdown of GLUL in breast cancer cell lines decreased cell proliferation and influenced expressions of specific downstream molecules. Through a Connectivity Map (CMap) analysis, we revealed that certain drugs/molecules, including omeprazole, methacholine chloride, ioversol, fulvestrant, difenidol, cycloserine, and MK-801, may serve as potential treatments for tamoxifen-resistant breast cancer patients. These drugs may be tested in combination with current therapies in tamoxifen-resistant breast cancer patients. Collectively, our study demonstrated the crucial roles of GLUL, which provide new targets for the treatment of tamoxifen-resistant breast cancer patients.

Prospects of Coffee Leaf against SARS-CoV-2 Infection.

In the current climate, many countries are in dire need of effective preventive methods to curb the Severe Acute Respiratory Syndrome Coronavirus Type 2 (SARS-CoV-2) pandemic. The purpose of this research is to screen and explore natural plant extracts that have the potential to against SARS-CoV-2 and provide alternative options for SARS-CoV-2 prevention and hand sanitizer or spray-like disinfectants. We first used Spike-ACE2 ELISA and TMPRSS2 fluorescence resonance energy transfer (FRET) assays to screen extracts from agricultural by-products from Taiwan with the potential to impede SARS-CoV-2 infection. Next, the SARS-CoV-2 pseudo-particles (Vpp) infection assay was tested to validate the effectiveness. We identified an extract from coffee leaf (Coffea Arabica), a natural plant that effectively inhibited wild-type SARS-CoV-2, and five Variants of Concern (Alpha, Beta, Gamma, Delta, and Omicron strain) from entering host cells. In an attempt to apply coffee leaf extract for hand sanitizer or spray-like disinfectants, we designed a skin-like gelatin membrane experiment. We showed that the high concentration of coffee leaf extract on the skin surface could block SARS-CoV-2 into cells more potently than 75% Ethanol, a standard disinfectant to inactivate SARS-CoV-2. Finally, LC-HRMS analysis was used to identify compounds such as caffeine, chlorogenic acid (CGA), quinic acid, and mangiferin that are associated with an anti-SARS-CoV-2 activity. Our results demonstrated that coffee leaf extract, an agricultural by-product effectively inhibits SARS-CoV-2 Vpp infection through an ACE2-dependent mechanism and may be utilized to develop products against SARS-CoV-2 infection.

N-3 polyunsaturated fatty acids block the trimethylamine-N-oxide- ACE2- TMPRSS2 cascade to inhibit the infection of human endothelial progenitor cells by SARS-CoV-2.

Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) is a novel coronavirus that infects many types of cells and causes cytokine storms, excessive inflammation, acute respiratory distress to induce failure of respiratory system and other critical organs. In this study, our results showed that trimethylamine-N-oxide (TMAO), a metabolite generated by gut microbiota, acts as a regulatory mediator to enhance the inerleukin-6 (IL-6) cytokine production and the infection of human endothelial progenitor cells (hEPCs) by SARS-CoV-2. Treatment of N-3 polyunsaturated fatty acids (PUFAs) such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) could effectively block the entry of SARS-CoV-2 in hEPCs. The anti-infection effects of N-3 PUFAs were associated with the inactivation of NF-κB signaling pathway, a decreased expression of the entry receptor angiotensin-converting enzyme 2 (ACE2) and downstream transmembrane serine protease 2 in hEPCs upon the stimulation of TMAO. Treatment of DHA and EPA further effectively inhibited TMAO-mediated expression of IL-6 protein, probably through an inactivation of MAPK/p38/JNK signaling cascades and a downregulation of microRNA (miR)-221 in hEPCs. In conclusion, N-3 PUFAs such as DHA and EPA could effectively act as preventive agents to block the infection of SARS-CoV-2 and IL-6 cytokine production in hEPCs upon the stimulation of TMAO.

Potential natural products that target the SARS-CoV-2 spike protein identified by structure-based virtual screening, isothermal titration calorimetry and lentivirus particles pseudotyped (Vpp) infection assay.

BACKGROUND AND AIM: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) enters cells through the binding of the viral spike protein with human angiotensin-converting enzyme 2 (ACE2), resulting in the development of coronavirus disease 2019 (COVID-19). To date, few antiviral drugs are available that can effectively block viral infection. This study aimed to identify potential natural products from Taiwan Database of Extracts and Compounds (TDEC) that may prevent the binding of viral spike proteins with human ACE2 proteins. METHODS: The structure-based virtual screening was performed using the AutoDock Vina program within PyRX software, the binding affinities of compounds were verified using isothermal titration calorimetry (ITC), the inhibitions of SARS-CoV-2 viral infection efficacy were examined by lentivirus particles pseudotyped (Vpp) infection assay, and the cell viability was tested by 293T cell in MTT assay. RESULTS AND CONCLUSION: We identified 39 natural products targeting the viral receptor-binding domain (RBD) of the SARS-CoV-2 spike protein in silico. In ITC binding assay, dioscin, celastrol, saikosaponin C, epimedin C, torvoside K, and amentoflavone showed dissociation constant (K d) = 0.468 µM, 1.712 µM, 6.650 µM, 2.86 µM, 3.761 µM and 4.27 µM, respectively. In Vpp infection assay, the compounds have significantly and consistently inhibition with the 50-90% inhibition of viral infection efficacy. In cell viability, torvoside K, epimedin, amentoflavone, and saikosaponin C showed IC50 > 100 µM; dioscin and celastrol showed IC50 = 1.5625 µM and 0.9866 µM, respectively. These natural products may bind to the viral spike protein, preventing SARS-CoV-2 from entering cells. SECTION 1: Natural Products. TAXONOMY CLASSIFICATION BY EVISE: SARS-CoV-2, Structure-Based Virtual Screening, Isothermal Titration Calorimetry and Lentivirus Particles Pseudotyped (Vpp) Infection Assay, in silico and in vitro study.

Scutellaria barbata D. Don Inhibits the Main Proteases (Mpro and TMPRSS2) of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection.

In late 2019, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic emerged to severely impact the global population, creating an unprecedented need for effective treatments. This study aims to investigate the potential of Scutellaria barbata D. Don (SB) as a treatment for SARS-CoV-2 infection through the inhibition of the proteases playing important functions in the infection by SARS-CoV-2. FRET assay was applied to investigate the inhibitory effects of SB on the two proteases involved in SARS-CoV-2 infection, Mpro and TMPRSS2. Additionally, to measure the potential effectiveness of SB treatment on infection inhibition, cellular models based on the Calu3 and VeroE6 cells and their TMPRSS2- expressing derivatives were assessed by viral pseudoparticles (Vpp) infection assays. The experimental approaches were conjugated with LC/MS analyses of the aqueous extracts of SB to identify the major constituent compounds, followed by a literature review to determine the potential active components of the inhibitory effects on protease activities. Our results showed that SB extracts inhibited the enzyme activities of Mpro and TMPRSS2. Furthermore, SB extracts effectively inhibited SARS-CoV-2 Vpp infection through a TMPRSS2-dependent mechanism. The aqueous extract analysis identified six major constituent compounds present in SB. Some of them have been known associated with inhibitory activities of TMPRSS2 or Mpro. Thus, SB may effectively prevent SARS-CoV-2 infection and replication through inhibiting Mpro and TMPRSS2 protease activities.