[Effects of hypoxia on the secretions of proinflammatory cytokines TNF-alpha and IL-6 in macrophages and its mechanism].

Aim: To investigate the effects of hypoxia on the secretions of proinflammatory cytokines TNF-alpha and IL-6 and to inquire into the mechanism.

Methods: Separated mice abdominal macrophages which were identified with non-specific esterase dye method, and created the hypoxic cultured model. The levels of TNF-alpha and IL-6 in the medium were determined by ELISA method. The mRNA expressions of TNF-alpha and IL-6 were measured by RT-PCR method. NF-kappaB activation was assayed by Western blot method. Finaly, we added cortone (5 microg/ml) to the medium, then observed the secretion levels of TNF-alpha and IL-6 during hypoxia.

Results: The secretions of TNF-alpha and IL-6 from Mphi exposed to hypoxia for 12 h were increased significantly compared with control (P < 0.01). The expressions of TNF-alpha mRNA and IL-6 mRNA were enhanced obviously contrasted with control (P < 0.01). NF-kappaB activation in Mphi nuclei was raised at 2 h during hypoxia and persisted to 5 h. We added cortone to the medium and found no significant change in secretion of TNF-alpha and IL-6 during hypoxia.

Conclusion: Hypoxia could activate NF-kappaB and make it shift to nucleus which promoted the transcriptions and expressions of TNF-alpha and IL-6.