Effects of hypoxia on the secretions of proinflammatory cytokines TNF-alpha and IL-6 in macrophages and its mechanism / 中国应用生理学杂志

ABSTRACT

<p><b>AIM</b>To investigate the effects of hypoxia on the secretions of proinflammatory cytokines TNF-alpha and IL-6 and to inquire into the mechanism.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>Hypoxia could activate NF-kappaB and make it shift to nucleus which promoted the transcriptions and expressions of TNF-alpha and IL-6.</p>