Significance and successful construction of stable transfection of MH7A cells with lower TRAF2 expression using lentiviral vector / 安徽医科大学学报

Objective To construct a stable synovial cell line MH7A from rheumatoid arthritis(RA)patients using lentiviral vectors that interfere with the expression of tumor necrosis factor receptor associated factor 2(TRAF2),and to study the role of TNF-α-TRAF2 signaling in MH7A abnormal proliferation.Methods Based on the design principles of human TRAF2 gene sequence and shRNA sequence,three pairs of TRAF2 shRNA interference se-quences were designed and synthesized.The primers were annealed by PCR,and a linear vector was obtained by double enzyme digestion PLKO.1-puro.The linearized vector was connected to the annealed primers through Solu-tion I,and the connected products were introduced into receptive cells.The plates were coated,and positive colo-nies were selected for sequencing.Three different recombinant plasmids of PLKO.1-TRAF2-shRNA lentivirus were constructed,and lentivirus packaging plasmids was used to package logarithmic growth phase HEK 293T cells.Vi-rus solution was collected to infect MH7A cells.At the same time,puromycin was used to screen MH7A stable transgenic strains with low TRAF2 expression.CCK-8 method,Western blot,and qPCR were used to detect the proliferation function of MH7A induced by TNF-α and low expression of TRAF2,as well as downstream signal TRAF2,P65 protein expression and mRNA levels.Results PLKO.1-TRAF2-shRNA(1),PLKO.1-TRAF2-shR-NA(2),and PLKO.1-TRAF2-shRNA(3)lentivirus vector plasmids and control group lentivirus vector plasmids PLKO.1-puro were successfully constructed.The three TRAF2-shRNA lentivirus vector plasmids and control group lentivirus vector plasmids PLKO.1-puro were respectively introduced into the lentivirus packaging plasmid of HEK 293T to obtain virus solution.After infecting MH7A cells with the virus solution,they were treated with puromycin(2.00 μ G/mL)screening and obtaining MH7A stable transgenic plants after 2 days.Through qPCR and Western blot results,it was found that the expression of TRAF2 mRNA and protein in PLKO.1-TRAF2-shRNA(1)MH7A stably transfected cells was significantly reduced compared to the negative control group.The results of CCK-8 and Western blot showed that after knocking down TRAF2 in MH7A,the proliferation of MH7A cells with low TRAF2 expression induced by TNF-α and the phosphorylation level of P65 were significantly reduced.Conclusion A sta-ble transgenic strain of PLKO.1-TRAF2-shRNA(1)MH7A cells was successfully constructed to investigate the role of TNF-α-TRAF2 signal activation in mediating abnormal proliferation of RA synovial cells.

Eukaryotic expression，purification and activity identification of human His-GRK2 recombinant protein / 安徽医科大学学报

Objective@#To construct a human G protein-coupled receptor kinase 2 ( GRK2) eukaryotic expression system．@*Methods@#The primers were designed ，and the His-GRK2 target gene was amplified by PCR using the Pans-EGFP-GrK2 (full-length) gene as the template．The His-GRK2 target gene was connected to the pcDNA3．1EGFP eukaryotic expression vector． The pcDNA3. 1-EGFP-His-GRK2 plasmid was transfected into HEK 293T cells．48 h later，the expression of GRK2 protein was detected by Western blot，and the GRK2 protein was purified by nickel chelated magnetic bead method．The purification of GRK2 protein was detected by Coomassie bright blue staining and Western blot，and the activity of GRK2 protein was detected by His pull down. @*Results @#The results of double enzyme digestion and sequencing showed that pcDNA3. 1-EGFP-His-GRK2 eukaryotic expression plasmid was successfully constructed．Western blot analysis showed that the molecular weight of GRK2 protein was about 80 ku，indicating that GRK2 protein was successfully expressed in HEK 293T cells (t = 6. 433，P = 0. 003) ．GRK2 protein was purified by nickel chelated magnetic beads．His pull down experiment results showed that GRK2 was bound to prostaglandin E2 receptor 4 (EP4) ，suggesting that GRK2 protein had biological activity (t = 13. 5，P = 0. 000 2) ．@*Conclusion@#The pcDNA3．1-EGFP-His-GRK2 eukaryotic expression plasmid was correctly sequenced and the GRK2 recombinant plasmid was successfully constructed．The GRK2 recombinant plasmid was successfully expressed in eukaryotic cells HEK 293T and the protein expressed was biologically active.

Targeted inhibition of GRK2 kinase domain by CP-25 to reverse fibroblast-like synoviocytes dysfunction and improve collagen-induced arthritis in rats

Rheumatoid arthritis (RA) is an autoimmune disease and is mainly characterized by abnormal proliferation of fibroblast-like synoviocytes (FLS). The up-regulated cellular membrane expression of G protein coupled receptor kinase 2 (GRK2) of FLS plays a critical role in RA progression, the increase of GRK2 translocation activity promotes dysfunctional prostaglandin E4 receptor (EP4) signaling and FLS abnormal proliferation. Recently, although our group found that paeoniflorin-6'-