Baricitinib inhibits type Ⅰ IFN-signaling during SARS-CoV-2 infection in vitro / 中国热带医学

@#Abstract: Objective　To explore the antiviral effect of baricitinib in the SARS-CoV-2 infection and influence on cytokine levels. Methods　Calu-3 cells were infected with SARS-CoV-2 at MOI of 0.1, and the levels of inflammatory cytokines (IL-6, IL-8, TNF-α and IL-1β), interferon β (IFN-β) and interferon-stimulated gene, IFIT2 in the infected cells were analyzed by qRT-PCR methods. At the same time, Calu-3 cells were infected with SARS-CoV-2 (MOI=0.1) after being treated with baricitinib for 2 hours. Cells were collected at 0, 24, 36, and 48 hours, and analyzed for the mRNA of the above genes in the drug-treated and untreated groups. Results　The mRNA levels of IL-6, TNF-a, IL-1β, IFN-β and IFIT2 in Calu-3 infected by SARS-CoV-2 cells were increased significantly. These cytokines were increased by nearly 100-fold post-infection 48 h compared with the control (P<0.000 1), and continued to increase with the infection time (P<0.001 or P<0.000 1). The increase of IL-8 mRNA level was not as significant as IL-6, TNF-α, IL-8, IL-1β, but it also showed a 2-4 folds increase. Baricitinib does not affect the level of viral RNA in Calu-3 cells after SARS-CoV-2 infection (P>0.05). However, baricitinib can significantly inhibit the up-regulation of IL-6 and TNF-α levels induced by SARS-CoV-2 infection (5.25-fold and 3.90-fold down-regulation, respectively, P<0.01), and has little effect on the levels of IL-8 and IL-1β . In addition, the drug could also significantly down-regulate the increase in IFN-β and IFIT2 levels caused by viral infection (10.51-fold and 90.78-fold down-regulation, respectively, P<0.000 1). Conclusions　Baricitinib inhibits the release of inflammatory cytokines to some extent, but it drastically down-regulates the expression of interferons and interferon-stimulated genes (ISGs), and has limited antiviral effect on SARS-CoV-2. Considering that interferon signal pathways play important roles on viral infection, caution should be exercised when using baricitinib to treat COVID-19 patients.

Apoptosis of human tongue squamous cell carcinoma cell (CAL-27) induced by Lactobacillus sp. A-2 metabolites

Objective: To study the effect of Lactobacillus sp. A-2 metabolites on viability of CAL-27 cells and apoptosis in CAL-27 cells. Methods: Lactobacillus sp. A-2 metabolites 1 and 2 (LM1 and LM2) were obtained by culturing Lactobacillus sp. A-2 in reconstituted whey medium and whey-inulin medium; the cultured CAL-27 cells were treated with different concentrations of LM1 and LM2 (0, 3, 6, 12, 24, 48 mg/mL) and assayed by methyl thiazolyltetrazolium (MTT) method; morphological changes of apoptotic cell were observed under fluorescence microscopy by acridine orange (Ao) fluorescent staining; flow cytometry method (FCM) and agarose gel electrophoresis were used to detect the apoptosis of CAL-27 cells treated LM1 and LM2. Results: The different concentrations of LM1 and LM2 could restrain the growth of CAL-27 cells, and in a dose-dependent manner; the apoptosis of CAL-27 cells was obviously induced and was time-dependent. Conclusions: Viability of CAL-27 cells was inhibited by Lactobacillus sp. A-2 metabolites; Lactobacillus sp. A-2 metabolites could induce CAL-27 cells apoptosis; study on the bioactive compounds in the Lactobacillus sp. A-2 metabolites and their molecular mechanism is in progress. .

Construction of Eukaryotic Expression Plasmid of hTGF-β3 and Its Inducing Effect on Differentiation of Precartilaginous Stem Cells into Chondroblasts / 华中科技大学学报（医学）（英德文版）

This study examined the construction of eukaryotic expression plasmid of human transforming growth factor-β3 (hTGF-β3) and its inducing effect on the differentiation of precartilaginous stem cells (PSCs) into chondroblasts.hTGF-β3 gene was amplified by using polymerase chain reaction (PCR) and then inserted into the eukaryotic expression plasmid pcDNA3.1 to construct the eukaryotic expression plasmid pcDNA3.1(+)-hTGF-β3.Rat PSCs were isolated and purified by employing an immunomagnetic cell sorting system.pcDNA3.1(+)-hTGF-β3 was transfected into purified PSCs with the use of linear polyamines.The expression of TGF-β3 and cartilage-specific extracellular matrix (ECM)components was detected after transfection by real-time quantitative PCR,ELISA,immunochemistry and Western blotting,respectively.The results showed that the eukaryotic expression plasmid pcDNA3.1(+)-hTGF-β3 was successfully established as identified by enzyme digestion and DNA sequencing.Real-time quantitative PCR and ELISA revealed that hTGF-β3 was strongly expressed in pcDNA3.1(+)-hTGF-β3-transfected PSCs.Real-time quantitative PCR,immunochemistry and Western blotting showed that the cartilage-specific ECM markers,i.e.,cartilage oligomeric matrix protein (COMP),Aggrecan,collagen type Ⅹ and Ⅱ were intensely expressed in the pcDNA3.1(+)-hTGF-β3-transfected cells.It was concluded that hTGF-β3 could be stably expressed in pcDNA3.1(+)-hTGF-β3-transfected PSCs and induce the differentiation of PSCs into chondroblasts.