[Effect of hypoxia on the expression of macrophage migration inhibitory factor (MIF) in rat vascular smooth muscle cells]

Objective: To investigate whether hypoxia could induce the expression of MIF in vascular smooth muscle cells (VSMCs).

Methods: Rat vascular smooth muscle cells (A7r5 from ATCC) were cultured under hypoxia condition (37 degrees C, 5% CO2, 1% O2) and normoxia condition (37 degrees C, 5% CO2, 20% O2) for 2, 4, 12, 24 or 48 hours respectively. MIF mRNA expression was detected by Reverse Transcriptase and polymerase chain reaction (RT-PCR). MIF protein expression was determined by Enzyme-Linked Immunosorbent Assay (ELISA).

Results: Expression of MIF mRNA was up-regulated as early as 2 hours in VSMCs after being exposed to hypoxia condition, which remained the elevated level up to 48 hours. Meanwhile, MIF protein level increased after hypoxia treatment for 2 hours, and maintained elevated status up to 48 hours.

Conclusion: Hypoxia could significantly induce MIF expression in VSMCs. MIF might be an important factor in the patho-physiological response of VSMCs to hypoxia.