Rapid detection and genotyping of SARS-CoV-2 Omicron BA.4/5 variants using a RT-PCR and CRISPR-Cas12a-based assay / 南方医科大学学报

OBJECTIVE@#To establish a rapid detection and genotyping method for SARS-CoV-2 Omicron BA.4/5 variants using CRISPPR-Cas12a gene editing technology.@*METHODS@#We combined reverse transcription-polymerase chain reaction (RT-PCR) and CRISPR gene editing technology and designed a specific CRISPPR RNA (crRNA) with suboptimal protospacer adjacent motifs (PAM) for rapid detection and genotyping of SARS- CoV-2 Omicron BA.4/5 variants. The performance of this RT- PCR/ CRISPPR-Cas12a assay was evaluated using 43 clinical samples of patients infected by wild-type SARS-CoV-2 and the Alpha, Beta, Delta, Omicron BA. 1 and BA. 4/5 variants and 20 SARS- CoV- 2-negative clinical samples infected with 11 respiratory pathogens. With Sanger sequencing method as the gold standard, the specificity, sensitivity, concordance (Kappa) and area under the ROC curve (AUC) of RT-PCR/CRISPPR-Cas12a assay were calculated.@*RESULTS@#This assay was capable of rapid and specific detection of SARS- CoV-2 Omicron BA.4/5 variant within 30 min with the lowest detection limit of 10 copies/μL, and no cross-reaction was observed in SARS-CoV-2-negative clinical samples infected with 11 common respiratory pathogens. The two Omicron BA.4/5 specific crRNAs (crRNA-1 and crRNA-2) allowed the assay to accurately distinguish Omicron BA.4/5 from BA.1 sublineage and other major SARS-CoV-2 variants of concern. For detection of SARS-CoV-2 Omicron BA.4/5 variants, the sensitivity of the established assay using crRNA-1 and crRNA-2 was 97.83% and 100% with specificity of 100% and AUC of 0.998 and 1.000, respectively, and their concordance rate with Sanger sequencing method was 92.83% and 96.41%, respectively.@*CONCLUSION@#By combining RT-PCR and CRISPPR-Cas12a gene editing technology, we successfully developed a new method for rapid detection and identification of SARS-CoV-2 Omicron BA.4/5 variants with a high sensitivity, specificity and reproducibility, which allows rapid detection and genotyping of SARS- CoV-2 variants and monitoring of the emerging variants and their dissemination.

Effect of diallyl trisulfide on the expression of folate receptor α in human gastric cancer cell lines BGC823 and AGS and the related regulatory mechanism / 肿瘤研究与临床

Objective:To investigate the effect of diallyl trisulfide (DATS) on the expression of folate receptor α (FRα) in human gastric cancer cells and the related regulatory mechanism.Methods:Human gastric cancer cell lines BGC823 and AGS were selected, BGC823 cells were treated with 10, 20, 40, 80 μmol/L DATS for 48 hours, and AGS cells were treated with 5, 10, 20, 40 μmol/L DATS for 48 hours. Cells treated with 6 μmol/L histone deacetylase (HDAC) inhibitor trichostatin A (TSA) were used as positive control for epigenetic study, and cells untreated with DATS were used as negative control. The apoptosis of gastric cancer cells induced by DATS was detected by flow cytometry. After BGC823 and AGS cells were treated by DATS for 48 hours, they were replaced with DATS-free cell culture medium and cultured for different time to detect the changes in FRα protein expression. BGC823 and AGS cells were treated with 6 μmol/L TSA or 40 μmol/L DATS. The protein expression levels of FRα, HDAC1 and HDAC2, and histone H3 lysine 9 acetylation (H3K9ac) and histone H4 lysine 5 acetylation (H4K5ac) were detected by Western blot. BGC823 cells were inoculated into BALB/c nude mice to establish tumor bearing model. The nude mice in DATS group were injected intraperitoneally with 10 mg/kg DATS for 16 days, and then the protein in tumor-bearing tissues was extracted to detect the expression of target protein, while the control group was injected with equal dose of 0.9% NaCl solution.Results:The expressions of FRα protein in BGC823 and AGS cells were up-regulated in a dose-dependent way after gradient concentrations of DATS treatment ( F = 65.68, P < 0.01; F = 26.65, P < 0.01). After changing the cell culture medium without DATS, the expressions of FRα protein in BGC823 and AGS cells gradually decreased and returned to the initial levels ( F = 74.57, P < 0.01; F = 30.92, P < 0.01). With the increase of DATS concentration, the apoptosis rates of BGC823 and AGS cells increased ( F = 32.95, P < 0.01; F = 38.97, P < 0.01). After TSA treatment, FRα protein expressions in BGC823 and AGS cells were up-regulated by 4.5 times ( t = -12.62, P < 0.01) and 3.6 times ( t = -10.00, P < 0.01). After 40 μmol/L and 20 μmol/L DATS treatment, the expression level of FRα protein in BGC823 and AGS cells was up-regulated (both P < 0.01), the expressions of HDAC1 and HDAC2 were inhibited (all P < 0.01), and the levels of H3K9ac and H4K5ac acetylation modification increased (all P < 0.01). The results of tumor-bearing nude mice experiment showed that the volume of transplanted tumor in DATS group was smaller than that in the control group [(214±39) mm 3 vs. (577±98) mm 3], and the difference was statistically significant ( t = 4.86, P < 0.01). Compared with the control group, FRα protein expression in the transplanted tumor tissues of DATS group was up-regulated about 2 times ( t = -5.29, P < 0.01), and the expression levels of HDAC1 and HDAC2 proteins were down-regulated ( t = 9.36, P < 0.01; t = 9.88, P < 0.01). Conclusions:DATS up-regulates the expression of FRα protein in human gastric cancer BGC823 and AGS cells in a dose-dependent and reversible manner. The mechanism may be related to the effect of DATS on histone acetylation modification in tumor cells.

Effect of Noggin silencing on the BMP and Wnt signaling pathways / 中国实验动物学报

Objective To analyze the effect of Noggin silencing on the BMP and Wnt signaling pathways in hair follicle development.Methods The expression of BMP-2, BMP-4, BMPR-IA, BMP-6, BMP-7, LEF-1 andβ-catenin in Noggin silencing MC3T3-E1 stable cell line was detected by RT-PCR and western blot.Results RT-PCR results showed that the expressions of five genes in BMP signaling pathway were all significantly influenced by Noggin silencing, the ex-pressions of BMP-2 (P<0.001), BMP-4 (P<0.01), BMP-6 (P<0.001) and BMP-7 (P<0.001) were all increased and the expression of BMPR-IA (P<0.01) was decreased.While the expressions of the two genes LEF-1 (P<0.001) and β-catenin ( P<0.001) in Wnt signaling pathway were significantly decreased.Western blot results showed that the ex-pressions of these proteins in the two signaling pathways were also affected.The expressions of BMP-2 (P<0.05), BMP-4 (P<0.05), BMP-6 (P<0.05) and BMP-7 (P<0.05) were all increased, while the expressions of BMPR-IA (P<0.05), LEF-1 (P<0.01) andβ-catenin (P<0.001) were decreased.Conclusions There may be a negative feedback regulation of Noggin on the BMP signaling pathway in vitro, but a positive feedback regulation on the Wnt signaling pathway in vitro.It provides certain evidence for studies on the effect of Noggin gene on BMP and Wnt signaling pathways in vivo. There may be an interaction between hair follicle development-related signaling pathways, which still needs further experi-ments to prove.

Construction of eukaryotic vector of monkey B virus glycoprotein D gene and the gD gene expression / 中国比较医学杂志

Objective To establish an eukaryotic vector of monkey B virus glycoprotein D gene and analyze the expression of gD gene in human embryonic kidney 293T cells.Method First, the protein of monkey B virus glycoprotein D was obtained by gene synthesis.The gene fragments were digested with Pst I and Not I, and ligated to pEGPF-N3. Then, the recombinant plasmid pEGPF-N3-GD was transfected into 293T cells.The expression of gD protein in the cells was detected by Western blot, and the expression localization was investigated using laser scanning confocal microscopy. Results The recombinant plasmid pEGPF-N3 carrying gD gene was successfully constructed, and normally expressed in the 293T cells.Conclusions Glycoprotein D of monkey B virus is expressed successfully in the 293T cells and the protein is located on the cell surface.It may be useful for the preparation of specific recombinant antigen to the glycoprotein D of monkey B virus on cell surface, and can be also used for preparation of antigen slide for detection of monkey B virus.

Packaging of the recombinant lentivirus of iRhom2 and its mutant and establishment of a stable iRhom2-expressing cell line / 中国实验动物学报

Objective To establish a stable transfection cell line of iRhom2 and its mutant through recombinant lentivirus infection.Methods The full-length gene of iRhom2 and its mutant were cloned into the lentivirus vector Lenti-OE-Flag, and got recombinant lentiviral vector of Lenti-OE-iRhom2 and Lenti-OE-iRhom2mut.The constructed recombi-nant lentivirus vectors were transfected into HEK-293T packaging cells to obtain the recombinant virus.Vero cells were in-fected with recombinant virus.The stable expressing cell lines were obtained by pressure screening with puromycin. Results The recombinant lentivirus vectors were constructed and the recombinant virus was obtained.The stable express-ing cell lines were obtained using virus infection and the protein expression was testified with Western blotting.Conclu-sions Stable iRhom2-expressing Vero cell line and its mutant are achieved by recombinant lentivirus infection.It paves the way for future study on biological functions and mechanism of iRhom2.

Synthesis and eukaryotic expressing of the gene encoding extracellular domains of gB protein B virus / 中国比较医学杂志

Objective To get the gene encoding extracellular domains of gB protein of B virus and analyze its expression in the eukaryocyte cell.Methods synthesizing gene fragment encoding extracellular domains of gB protein of B virus was by using synthesis gene, then digested with the restriction endonucleases BamHⅠand NotⅠand inserted into eukaryotic expressing vector pEGFP-N3.pEGFP-N3-GB合 was transfected into 293 cells.After protein extraction, the expression of gene was detcted by western blotting, and the cellular localization of the gene was analyzed by immunofluorescence and laser scanning confocal microscopy.Results pEGFP-N3-GB合were expressed in 293 cells and on the cell membrane.Conclusion eukaryotic expressing system can produce specific antigen recombination protein of B virus gB protein and express on the cell membrane.

Denominate chiasm of crus penis / 中华泌尿外科杂志

Objective Definition Chiasm of crus penis and discuss its possible role in penile erection. Methods Penile samples were acquired from 15 formalin preserved corpses.The structure located among crus penises were observed.The information about the structure located in crus penises with the nerve and blood vessel structure were recorded and analyzed. Results There was a structure of muscle fiber of ischiocavernosus among the crus penises.These muscle fiber through muscle bundle and tendon reach albuginea of cavernous body of the penis.There was long muscle fiber in the lateral surface of crus penises.While the muscle bundles were interlaced with each other with opposite side homonymous muscle and were encased with connective tissue when it reach to the back side of cavernous body of the penis.There were nerves and blood vessels observed in and out of the cavernous body of the penis and through the above structure in the crus penises. Conclusions Chiasm of crus penis was named as a structure of muscle fiber coming from two sides of the ischiocavernosus in crus penises.The structure of Chiasm of crus penis may provide an internal connection for the role of controlling the erection of the penis.