Study On The Role Of Nuclear Transcription Factor κB In Premature Delivery Associated With Infection

Background:Premature delivery (PRD) is a common complication of pregnancy which resulted in uterus constraction and dilitation of cervix and at last the pregnancy terminated earlier than normal,and PRD is one of the most important reasons for the perinatal sickness and death.It is well known that the infection of genital tract could cause PRD. PRD associated with infection means the PRD related to the infection of genital tract,especially to the infection of amniotic cavity which is the the infection of genital tract in the third trimester of pregnancy.Once threatened labor of PRD takes place and the opening of cervix is bigger than 3 cm, delivery usually is inevitable. But the mechanism of delivery of PRD associated with infection remained unknown.Recently, cytokine(CK) is thought to play a vital role in PRD associated with infection:Some CKs increased the synthesis of prostaglandin(PG), which is proved to promote contraction of smooth muscle of uterus and the soften of cervix to initiate labor; Some CKs can directly lead to the onset of parturition; The embalance of the network of CKs can result in cascade reactions and the excessive synthsis of some functional proteins and other cytokines to induce the contraction of uterine and delivery.Nuclear transcription factor κB (NF-κB) is regarded as an upstream key factor to regulate expression of CKs, which is an essential factor to induce the transcription of inflammatory genes too. NF-κB is a convergence point of many signal conduction pathways and could lead to highly effictive expression of chemokines, adherence factors,many cytokines(such as IL-6,IL-8,IL-1,TNF-α) and acute phase proteins. When PRD associated with infection occurs, the activation of NF-κB pathway and nuclear transcription increased inflammatory cytokines, which lead to constraction of uterus and dilatation of cervix and may be the key point for the mechanism of delivery of PRD associated with infection. In this projection,the function of NF-κB, which has close relationship with infection, was explored and the mechanism was illustrated in patients with PRD associated with infection.Metheods: NF-κB and some cytokines in the placenta tissues from 23 parturiens with PRD associated with IAI, 18 parturiens with PRD without IAI and 24 parturiens with term delivery were detected.The effects of PDTC(Pyrrolidine dithiocarbamate) ,the inhabitor of NF-κB, on expression of CKs in mice with PRD and the outcome of the pregnant mice were observed. model that treated by beforehand was performed.After solving these problems ,we illustrate the mechanism of PRD associated with IAI which can provide laborary foundation for clinical therapy through modulating NF-κB. Results and conclusion: The expression of NF-κB p65,TNF-α and IL-8 was higher than that of other groups.They may play a vital role in parturiens with PRD associated with IAI .In the placenta tissues of the mice with PRD associated with simulating IAI, after an application of PDTC, TNF-α and IL-8 decreased and the gestion time could maintain longer. This indicates that the obstruction of the pathway of NF-κB by PDTC could decrease the incidence of PRD and expression of TNF-α and IL-8 in gestational tissues. Therefore NF-κB may play a great role in PRD associated with infection through modulating the synthesis of CKs.