ABSTRACT
Aim To observe the effect of laminarin L01 on the expression of eNOS and iNOS in aorta of rats with chronic inflammation induced by LPS. Methods Chronic inflammatory rat models were prepared by tail vein injection low dose LPS(0.4 mg·kg-1) once a week for four weeks. The rats were randomly divided into five groups. After the first injection of LPS, the DXM group was intraperitoneally injected with dexam-ethasone (10 mg·kg-1). L01 high,medium and low dose groups were intraperitoneally injected with L01 (50,30,10 mg·kg-1). The LPS group was injected intraperitoneally with equal volume of normal saline once a day. Another control group, only injection of normal saline, a total of four weeks. After the last administration,the number of whole white blood cells (WBC) was counted. ELISA was used to measure the hs-CRP in serum. The expressions of eNOS,iNOS and COX-2 mRNA were detected by RT-PCR. Results After four weeks of administration of L01, the number of WBC and the level of serum hs-CRP in chronic in-flammatory rats were significantly decreased. The ex-pression of eNOS was up-regulated, and iNOS and COX-2 expressions were down-regulated. Conclusions Laminarin L01 may regulate the expression and re-lease of endothelium-derived relaxing factor stimulated by LPS,and improve the endothelium-dependent dias-tolic function of aorta, thus protecting the damage of vascular endothelium.
ABSTRACT
Objective:To construct I-Ad/IgG2b Fc baculovirus expression vector and express I-Ad/IgG2b Fc dimer fusion protein in Sf9 insect cells.Methods:I-Ad α,I-Ad β and IgG2b Fc gene sequences were amplified from BALB/c mouse lymphocytes by RT-PCR.I-Ad α and I-Ad β were connected with the leucine zipper sequence Fos and Jun respectively by overlapping PCR to form I-Ad α-Fos and I-Ad β-Jun.I-Ad α-Fos and IgG2b Fc fragments were ligated by restriction sites Xba I to form I-Ad α-Fos-IgG2b Fc recombination sequence.I-Ad α-Fos-IgG2b Fc and I-Ad β-Jun fragments were inserted to PPH and PP10,which were the downstream of the promoters in the plasmid pFastBacTMDual,to form pFastBacTMDual+[I-Ad/IgG2b Fc] recombinant plasmids.The constructed vector was identified by PCR,restriction endonuclease and sequencing.The recombinant plasmids pFastBacTMDual+[I-Ad/IgG2b Fc] was transferred into the DH10Bac competent cell to form recombinant baculovirus Bacmid+[I-Ad/IgG2b Fc].The recombinant baculovirus was transfected into Sf9 insect cells by liposome transfection reagent.After infected with Sf9 insect cells,the supernatant was collected and concentrated by PEG20000 to obtain I-Ad/IgG2b Fc dimer fusion protein.The fusion protein was detected by double-antibody sandwich ELISA and Western blot.Results:PCR,restriction enzyme digestion and sequencing confirmed that the recombinant vector pFastBacTMDual+[I-Ad/IgG2b Fc] had the correct sequence.The double antibody sandwich ELISA and Western blot showed that recombinant bacmid could successfully infect Sf9 insect cells,and the expressed fusion protein had the correct conformation.Conclusion:The pFastBacTMDual+[I-Ad/IgG2b Fc] baculovirus expression vector was successfully constructed and expressed in Sf9 insect cells,laying a foundation for the study of I-Ad-restricted T cells.