Construction and Characterization of Severe Fever with Thrombocytopenia Syndrome Virus with a Fluorescent Reporter for Antiviral Drug Screening.

Severe fever with thrombocytopenia syndrome (SFTS) caused by a novel bunyavirus (SFTSV) is an emerging infectious disease with up to 30% case fatality. Currently, there are no specific antiviral drugs or vaccines for SFTS. Here, we constructed a reporter SFTSV in which the virulent factor nonstructural protein (NSs) was replaced by eGFP for drug screening. First, we developed a reverse genetics system based on the SFTSV HBMC5 strain. Then, the reporter virus SFTSV-delNSs-eGFP was constructed, rescued, and characterized in vitro. SFTSV-delNSs-eGFP showed similar growth kinetics with the wild-type virus in Vero cells. We further detected the antiviral efficacy of favipiravir and chloroquine against wild-type and recombinant SFTSV by the quantification of viral RNA, and compared the results with that of fluorescent assay using high-content screening. The results showed that SFTSV-delNSs-eGFP could be used as a reporter virus for antiviral drug screening in vitro. In addition, we analyzed the pathogenesis of SFTSV-delNSs-eGFP in interferon receptor-deficient (IFNAR-/-) C57BL/6J mice and found that unlike the fatal infection of the wild-type virus, no obvious pathological change or viral replication were observed in SFTSV-delNSs-eGFP-infected mice. Taken together, the green fluorescence and attenuated pathogenicity make SFTSV-delNSs-eGFP a potent tool for the future high-throughput screening of antiviral drugs.

Effects of compound deer bone extract on osteoporosis model mice and intestinal microflora.

The preventive and therapeutic mechanisms of CDBE on osteoporosis were studied by observing the serum bone-related biochemical indicators, bone trabecular micro-structure and intestinal flora in ovariectomized osteoporosis model mice, in order to provide a scientific theoretical basis for the further study on the effect of CDBE on osteoporosis, and the prevention and treatment of osteoporosis with clinical traditional Chinese medicines. The components in CDBE were detected by UHPLC-MS. A mouse osteoporosis model was established by the bilateral ovariectomy in female ICR mice. The biochemical indicators related to osteoporosis were detected, the right proximal tibia was scanned by Micro-CT, the intestinal microflora in the colon contents were examined, and the changes of microflora were taken as the main target to evaluate the effect of CDBE on the intestinal microflora in the model mice. A total of 16 compounds were obtained by the combined application of UHPLC-MS. CDBE could significantly increase the contents of E2, Ca2+ , CT, HyP, OCN, FOXP3, P1NP and CTX-II, in the model mice. CDBE could significantly improve the trabecular micro-structure, Tb.N, Tb.Sp, SMI and Conn.D. CDBE could make the intestinal flora of osteoporosis model mice tend to healthy mice in species and quantity. CDBE can improve the symptoms of postmenopausal osteoporosis in mice, with a positive effect on the intestinal flora of postmenopausal mice. Its mechanism of regulating the symptoms of osteoporosis may be related to the regulation of bone-related biochemical indicators in the serum of mice. PRACTICAL APPLICATIONS: This research has a positive impact on the development of functional food with anti-osteoporosis in the future.

An organoid-based drug screening identified a menin-MLL inhibitor for endometrial cancer through regulating the HIF pathway.

Tumor organoids recapitulate pathological properties and would serve as an excellent ex vivo model for drug discovery. Here, we performed an unbiased drug screening on drivers-defined tumor organoids from mouse endometrial cancer, the most prevalent gynecological malignancy in human, with a small molecule library targeting epigenetic factors. Among them, menin-MLL inhibitors MI-136 and MI-463 scored. The therapeutic capacity of MI-136 was further validated in tumor organoids in vitro and an orthotopic model in vivo. CRISPR/cas9-mediated mutations of major components of the menin-MLL complex, Men1, Kmt2a and Ash2l, inhibited the growth of tumor organoids, suggesting that the complex was the target of MI-136. Transcriptome analysis showed that the hypoxia-inducible factor (HIF) pathway was the most significantly downregulated pathway by MI-136 treatment. Consistently, Men1, Kmt2a, and Ash2l knockout also repressed the expressions of the HIF target genes. Loss of Hif1a or Hif1b partially phenocopied the inhibition of the menin-MLL complex by MI-136 or mutations in term of tumor organoid growth. Further, we found that MEN1 was upregulated in human endometrial cancers, which were tightly correlated with the expression levels of HIF1A, and associated with poor prognosis. Importantly, MI-136 also significantly inhibited the growth of endometrial cancer organoids derived from patients. Thus, our study identified MI-136 as a potential inhibitor for endometrial cancer through regulating the HIF pathway, a novel molecular mechanism distinguished from those in AML and prostate cancer.

Anti-SARS-CoV-2 Potential of Artemisinins In Vitro.

The discovery of novel drug candidates with anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) potential is critical for the control of the global COVID-19 pandemic. Artemisinin, an old antimalarial drug derived from Chinese herbs, has saved millions of lives. Artemisinins are a cluster of artemisinin-related drugs developed for the treatment of malaria and have been reported to have multiple pharmacological activities, including anticancer, antiviral, and immune modulation. Considering the reported broad-spectrum antiviral potential of artemisinins, researchers are interested in whether they could be used to combat COVID-19. We systematically evaluated the anti-SARS-CoV-2 activities of nine artemisinin-related compounds in vitro and carried out a time-of-drug-addition assay to explore their antiviral mode of action. Finally, a pharmacokinetic prediction model was established to predict the therapeutic potential of selected compounds against COVID-19. Arteannuin B showed the highest anti-SARS-CoV-2 potential with an EC50 of 10.28 ± 1.12 µM. Artesunate and dihydroartemisinin showed similar EC50 values of 12.98 ± 5.30 µM and 13.31 ± 1.24 µM, respectively, which could be clinically achieved in plasma after intravenous administration. Interestingly, although an EC50 of 23.17 ± 3.22 µM was not prominent among the tested compounds, lumefantrine showed therapeutic promise due to high plasma and lung drug concentrations after multiple dosing. Further mode of action analysis revealed that arteannuin B and lumefantrine acted at the post-entry step of SARS-CoV-2 infection. This research highlights the anti-SARS-CoV-2 potential of artemisinins and provides leading candidates for anti-SARS-CoV-2 drug research and development.

[Effect of cigarette smoke extract on RAW264. 7 cell proliferation, autophagy and its mechanism].

OBJECTIVE: To inquiry the effects of cigarette smoke extract(CSE) on RAW264. 7 cell proliferation, autophagy and its mechanism. METHODS: RAW264. 7 cell were used and divided into control, starvation and CSE group(2%, 3%, 4%, 5%CSE). CCK-8 was used to detect the toxic action of CSE on RAW264. 7 cell. Western blot and mRFP-GFP-LC3 cell fluorescence spot count were used to explore the function of CSE on RAW264. 7 cell autophagy and its mechanism. RESULTS: Compared with the control group, the result of CCK-8(0. 671 ± 0. 03、0. 746± 0. 10、0. 584 ± 0. 07、0. 588±0. 05) showed that CSE inhibit the proliferation of RAW 264. 7 cell on 24 hours, the difference was statistically significant(P < 0. 05). The outcomes of Western blot showed that, compared with the control group, LC3 B in the CSE group increased, difference in 6(6. 612 ± 0. 35)/12(4. 383 ± 1. 99)/24(5. 781 ± 0. 78) hours, while P62 decreased in 6(1. 815±0. 08)/12(4. 383±1. 99)/24(0. 414±0. 06) hours also different, P-mTOR(1. 744 ± 0. 15) and P-AKT(0. 376 ± 0. 03) decreased, the difference was statistically significant(P<0. 05), but Beclin1 was not significantly changed. The mRFP-GFP-LC3 cell fluorescence spot count showed that the green fluorescence spot(GFP)decreased and the red fluorescence spot(mRFP) remained stable in CSE group, combined mRFP-GFP is shown as yellow and red spots. CONCLUSION: CSE has toxic effect on cell proliferation and leads to RAW264. 7 cell autophagy enhanced through AKT/m TOR pathways.

A selenium polysaccharide from Platycodon grandiflorum rescues PC12 cell death caused by H2O2 via inhibiting oxidative stress.

In this paper, a selenium polysaccharide (PGP1) was isolated from the radix of Platycodon grandiflorum. We investigated the protective capacity of PGP1 against the hydrogen peroxide (H2O2)-induced oxidative damage in cultured rat pheochromocytoma (PC12) cells. Cells were pretreated with various doses of PGP1 (50, 100 and 200µg/mL) for 24h before exposure to 0.5mM H2O2 for 12h. Cell viability, LDH release, apoptotic rates, malondialdehyde (MDA) content, antioxidant enzyme superoxide dismutase (SOD) activity and intracellular accumulation of reactive oxygen species (ROS) were determined. The results showed pretreatment of PC12 cells with PGP1 prior to H2O2 exposure inhibited the decrease of cell viability, decreased the apoptotic rates, prevented membrane damage (LDH release) and attenuated intracellular ROS formation in PC12 cells injured by H2O2. Meanwhile, PGP1 increased SOD activity, while it decreased the level of MDA and the production of lipid peroxidation, in PC12 cells after H2O2 exposure. These findings suggested that PGP1 may be considered as a potential useful antioxidant agent in reducing neuronal oxidative damage via inhibiting oxidative stress.

Protective effect of Schisandrae chinensis oil on pancreatic ß-cells in diabetic rats.

Islet cell dysfunction in type 2 diabetes is primarily attributed to increased apoptosis of pancreatic ß-Cells. The aim of the present study was to investigate the effects of Schisandrae chinensis oil on pancreatic ß-Cells in type 2 diabetes mellitus rats and the associated molecular mechanisms of action. Wistar rats were randomly divided into diabetic rats and control rats, diabetic rats treated with Schisandrae chinensis oil (1 mg/kg), and control rats treated with Schisandrae chinensis oil. The serum fasting blood glucose, insulin, total cholesterol, and triglyceride levels along with MDA content, SOD and CAT activities in pancreatic tissues were measured. TUNEL was used to observe the apoptosis of rat pancreatic cells. Western blot was used to determine specific protein expression. The results showed that the oil significantly decreased fasting blood glucose, total cholesterol, triglyceride levels as well as the pancreatic MDA, but increased SOD and CAT activities. The protein expression of Bcl-2, PDX-1, GLUT-2, and GCK but not caspase 3 was significantly enhanced in the oil-treated rats compared with diabetic rats. However, Bax content was not significantly different between the control and DM groups. Schisandra chinensis oil improves pancreatic ß-cell function by enhancing antioxidant potential of the pancreas, upregulating the expression of anti-apoptotic genes, increasing expression of glucose metabolism, and delaying islet cell apoptosis.

Two-way effects of surfactants on Pickering emulsions stabilized by the self-assembled microcrystals of α-cyclodextrin and oil.

The influence of surfactants on the stability of cyclodextrin (CD) Pickering emulsions is not well understood. In this study, we report two-way effects of Tween 80 and soybean lecithin (PL) on the long term stability of Pickering emulsions stabilized by the self-assembled microcrystals of α-CD and medium chain triglycerides (MCT). The CD emulsions in the absence and presence of Tween 80 or PL at different concentrations were prepared and characterized by the droplet size, viscosity, contact angle, interfacial tension and residual emulsion values. After adding Tween 80 and PL, similar effects on the size distribution and contact angle were observed. However, changes of viscosity and interfacial tension were significantly different and two-way effects on the stability were found: (i) synergistic enhancement by Tween 80; (ii) inhibition at low and enhancement at high concentrations by PL. The stability enhancement of Tween 80 was due to the interfacial tension decrease caused by the interaction of Tween 80 with CD at the o/w interface at lower concentrations, and significant viscosity increase caused by the Tween 80-CD assembly in the continuous phase. For PL at low concentrations, the replacement of α-CD/MCT by α-CD/PL particles at the o/w interface was observed, leading to inhibitory effects. High concentrations of PL resulted in an extremely low interfacial tension and stable emulsion. In conclusion, the extensive inclusion of surfactants by CD leads to their unique effects on the stability of CD emulsions, for which the changes of viscosity and interfacial tension caused by host-guest interactions play important roles.