Expression of macrophage migration inhibitory factor mRNA in Schwann cells / 中华外科杂志

ABSTRACT

<p><b>OBJECTIVES</b>To investigate the expression of macrophage migration inhibitory factor (MIF) mRNA in Schwann cells after peripheral nerve injury and roles of Schwann cells and MIF in macrophages activation and nerve regeneration.</p><p><b>METHODS</b>Fifty SD rats were divided into 10 groups. One group served as normal control. The rest were anesthetized with 3% sodium pentobarbital (30 - 60 mg/kg, i.p) and sciatic nerves were transected distal to the obturator tendon respectively 1 h, 12 h, 1 d, 3 d, 7 d, 10 d, 14 d, 17 d and 21 d before being killed. Sciatic nerves were resected and connective tissues excised. Schwann cells were obtained by digesting the nerve tissues with trypsin and collagenase. RNA was isolated and reverse-transcription-polymerase chain reaction (RT-PCR) was carried out. cDNA was analyzed by automatic system and the parameters were assessed to define the status of MIF mRNA expression in different groups.</p><p><b>RESULTS</b>The level of MIF mRNA started to increase 12 h after the nerve transection. The level remained high from day 7 up to 10 after the injury. During the period from days 10 to 21, MIF mRNA decreased slowly to the pre-transection level.</p><p><b>CONCLUSION</b>After peripheral nerve injury, Schwann cells can secrete MIF which may play a pivotal role as an immunomodulatory cytokine in macrophage activation and inflammatory reaction.</p>