Retracted Article: Melatonin protects spinal cord injury by up-regulating IGFBP3 through the improvement of microcirculation in a rat model.

The present study was aimed at the investigation of the effects of melatonin on spinal cord injury (SCI) and the role of IGFBP3 in SCI both and . The rats received treatment with 100 mg kg melatonin or both melatonin and pGenesil-1-si-IGFBP3 (50 µg per g bw) after SCI surgery. The motor function in rats was measured using the Basso-Beattie-Bresnahan (BBB) scale score; perfusion vessel area was determined by injecting FITC-conjugated lycopersicon esculentum agglutinin lectin (FITC-LEA), whereas the blood-spinal cord barrier permeability was measured using Evans blue. The pericytes were isolated, and the cells were cultured under hypoxia, treated with melatonin or transfected with si-IGFBP3. RT-qPCR and western blotting were conducted for the determination of IGFBP3, VEGF, MMP-2, ICAM-1 and Ang1. The expression of IGFBP3 was significantly down-regulated in the SCI rats, and melatonin significantly enhanced the IGFBP3 level. Melatonin improved the motor function, reduced the neuron injury, and improved the microcirculation in rats. However, the down-regulation of IGFBP3 significantly reversed these effects. Moreover, in both the SCI rat spinal cord tissues and the pericytes under hypoxia, the expressions of IGFBP3 and Ang1 were significantly down-regulated, whereas those of the proteins MMP-2, VEGF and ICAM-1 were significantly up-regulated, and melatonin dramatically inhibited these changes. Melatonin could protect the rats from SCI by improving the microcirculation through the up-regulation of IGFBP3.