Relationship between the increase of secretion of sTNF alpha induced by lipopolysaccharides and the enhanced expression of TACE mRNA in HL-60 cells and adhesive cells from human spleen.

In order to find out the potential modulators which influence the secretion of TNF alpha, the relationship between the amount of secreted TNF alpha (sTNF alpha) and the level of TNF alpha converting enzyme (TACE) gene expression was studied before and after the stimulation by lipopolysaccharides (LPS) to HL-60 cells and adhered cells isolated from human spleen using cytological and molecular biology techniques and methods (RT-PCR, Dot-blot hybridization, etc.). The experimental results showed that: (1) LPS could induce the increase of expression of TNF alpha mRNA and TACE mRNA, reaching the peak value at 6 h and 10 h respectively after addition of LPS into cell culture medium; (2) The anti-sense oligodeoxyribonucleotide (A-ODN) complementary to TACE mRNA sequence really inhibited the secretion of TNF alpha as a result of blocked translation of TACE gene; (3) Furthermore, it was also observed that RDQ, a kind of injection derived from Chinese traditional herb, had strongly inhibitory effects on the expression of TACE mRNA and secretion of sTNF alpha stimulated by LPS. The above results suggested that the TACE indeed involved in delivering and processing of pro-TNF alpha during the period of LPS stimulation and the study about the regulator/inhibitors of TACE gene expression would be very important to develop new types of therapy agents against toxic and side effects of sTNF alpha during the period of infection/inflammation to human body.