ABSTRACT
Aim To express and purify rhα-Gal A with a 6 X His tag via using a serum-free expression system in high-density suspension culture of Chinese hamster ovary cells ( CHO-S) , and to verify the scavenging effect of rhα-Gal A on globular trisaccharide ceramide (Gb3 or GL3) . Methods The construction of recombinant protein expression vector, pcDNA4-GLA, was achieved by fusing the human α-galactosidase cDNA, gla, with 6 X His tag and artificial DNA synthesis. The expression plasmid was transfected into the suspended CHO-S to express rhα-Gal A and then purified. Following this procedure, we determined rhα-Gal A's expression, the enzymatic activity, and the glycosylation of the recombinant enzyme. Co-incubation with cultured cells was performed to examine whether rhα-Gal A could be taken up into the cells and effectively remove Gb3 substrates. Results rhα-Gal A was successfully expressed and purified after transiently transfecting pcDNA4-GLA into the suspended CHO-S, and the yield was up to (100 ±20. 6) mg • L
ABSTRACT
Objective:To explore the intervention effect of Yuxuebi tablet (YXB) on collagen-induced arthritis (CIA) in rats and its anti-inflammatory mechanism. Method:Following CIA modeling, the rats in the drug administration groups were separately treated with intragastric administration of YXB (0.1, 0.2, and 0.4 g·kg<sup>-1</sup>) and methotrexate (MTX, 0.4 mg·kg<sup>-1</sup>), once a day. The incidence of CIA, mechanical pain threshold (MPT) and cold pain threshold (CPT) were evaluated once every three days. After continuous administration for 30 days, the peripheral blood of rats was collected for the determination of platelet (PLT) count and fibrinogen (FIB) content. The hematoxylin-eosin (HE) staining was conducted to analyze the pathological changes in joint tissues. The protein expression levels of interleukin (IL)-1<italic>β</italic>, IL-8, nuclear transcription factor-<italic>κ</italic>B (NF-<italic>κ</italic>B) p65, phosphorylated NF-<italic>κ</italic>B (p-NF-<italic>κ</italic>B) p65, Ras, and Raf-1 in joint tissues of CIA rats were detected by immunohistochemistry (IHC) and Western blot. The rheumatoid arthritis fibroblast-like synoviocytes (RA-FLS) were induced by tumor necrosis factor-<italic>α</italic> (TNF-<italic>α</italic>, 10 μg·L<sup>-1</sup>) <italic>in vitro</italic> and then subjected to transwell migration/invasion assay, followed by the detection of protein expression levels of Ras, Raf-1, and p-NF-<italic>κ</italic>B p65 in RA-FLS by Western blot. Result:Compared with the control group, the model group exhibited an increased incidence of CIA, significantly decreased MPT (<italic>P</italic><0.05,<italic>P</italic><0.01), elevated CPT (<italic>P</italic><0.01) and PLT and FIB in the peripheral blood, worsened histopathological score of joints, enhanced RA-FLS migration and invasion, and up-regulated inflammatory factors (<italic>P</italic><0.01). The comparison with the model group revealed that YXB at different doses obviously reduced the incidence of CIA, increased MPT, down-regulated CPT and PLT and FIB in the peripheral blood (<italic>P</italic><0.05,<italic>P</italic><0.01), ameliorated the pathological changes like synovial hyperplasia and bone and cartilage destruction (<italic>P</italic><0.05,<italic>P</italic><0.01), and inhibited RA-FLS migration and invasion. Besides, the low-, medium-, and high-dose YXB reversed the IL-1<italic>β</italic>, IL-8, Ras, Raf-1, and p-NF-<italic>κ</italic>B p65 expression in joint tissues of CIA rats to different extents, as well as the protein expression of Ras, Raf-1 and p-NF-<italic>κ</italic>B p65 in RA-FLS (<italic>P</italic><0.05,<italic>P</italic><0.01). Conclusion:YXB reduces the incidence of CIA, ameliorates the clinical symptoms of RA and the pathological changes in joint tissues, and inhibits the formation of synovium, which may be attributed to its inhibition against Ras/Raf-1/NF-<italic>κ</italic>B signaling pathway.
ABSTRACT
Objective:To study the effects of licochalcone A (LCA) on the proliferation and apoptosis of rheumatoid arthritis fibroblast-like synoviocytes (MH7A) as well as the related inflammatory factors, also to reveal the relevance between mitogen activated protein kinase (MAPK) signaling pathway and LCA regulation of MH7A cell proliferation and apoptosis. Method:MH7A cells were cultured and divided into blank group, LCA groups (10,20,40 μmol·L-1). The proliferation of MH7A cells was detected by methylthiazolyldiphenyl-tetrazolium bromide(MTT)and immunofluorescence staining. The cell cycle of MH7A cells was determined by flow cytometry after PI staining and apoptosis was detected by flow cytometry after Annexin V/PI staining. The effect of LCA on interleukin-1β(IL-1β) mRNA was detected by Real-time fluorescence quantitative polymerase chain reaction(Real-time PCR). Western blot was used to detect the effect of LCA on the key proteins of MAPK signaling pathway, meanwhile, PD98059, a specific ERK inhibitor, was used to observe the expression levels of p-ERK and IL-1β. Result:Compared with blank group, LCA could inhibit the proliferation of MH7A cells in a dose-dependent manner, and the number of living cells decreased significantly(P<0.01), while the number of early apoptotic cells increased significantly(P<0.01). Compared with the tumor necrosis factor-α (TNF-α,10 μg·L-1)group, LCA could reverse the expression of IL-1β mRNA induced by TNF-α(P<0.01). and compared with the blank group, LCA also promoted the phosphorylation of ERK, JNK and p38 in a dose-dependent manner(P<0.01). After ERK inhibitor PD98059 inhibited ERK phosphorylation, the inhibitory effect of LCA 10, 20 μmol·L-1 on IL-1β disappeared. Conclusion:LCA can inhibit the proliferation and induce apoptosis of MH7A cells, which may be related to the phosphorylation of MAPK pathway related proteins, and then inhibit the expression of inflammatory factors.