THE CHANGES IN NF-κB SIGNAL PATHWAYS IN PULMONARY ALVEOLAR MACROPHAGES (PAM) STIMULATED BY LPS
Yin Wen, Yang Jianhong, Hu Xiaomin et al . Xijing Hospital, Fourth Military Medical University,Xi′an 710032,China
Objective To investigate changes in NF κB signal pathway in PAM stimulated by lipopolysaccharide(LPS) in vitro , and to explore the molecular pathological mechanism of acute lung injury(ALI). Methods After PAM were stimulated by LPS, the changes in expression of IKK mRNA, activation of NF κB, degradation of IκB, and secretion of TNF α in PAM were measured at 0, 15min, 30min, 1h, 2h, and 4h by in situ hybridization, electrophoretic mobility shift assay (EMSA), and enzyme linked immune absorbing analysis (ELISA), respectively. Results The expression of IKK β mRNA was increased 15min after LPS stimulation and reached the peak at 30 min, then returned to the base line after 1 hour. The changes in IκB α mRNA were opposite. The activity of NF κB was increased 15min after LPS stimulation, peaking at 1 hours, and returned to the pre stimulation level after 2 hours. The content of TNF α was increased initially at 30min, reached the peak at 1 hour, and gradually returned to the pre stimulation level in 2～4 hour. Conclusion The transduction pathway of activation of IKK β degradation of IκB/activation of NF κB/synthesization of TNF α might play a critical role in the molecular pathological mechanism of LPS induced ALI.