Spinal Cord Injury Intensity Modifies the Expression of Inflammation-Related Gene Expression after Immunization with Neural Derived Peptides

Previous studies revealed that the intensity of Spinal Cord Injury (SCI) plays a key role in the therapeutic effects induced by Immunizing With Neural-Derived Peptides (INDP), as severe injuries abolish the beneficial effects induced by INDP. In the present study, we analyzed the expression of some inflammation-related genes (IL6, IL12, IL-1β, IFNɣ, TNFα, IL-10, IL-4, and IGF-1) by quantitative PCR in rats subjected to SCI and INDP. We investigated the expression of these genes after a moderate or severe contusion. In addition, we evaluated the effect of INDP by utilizing2 different peptides: A91 and Cop-1. After moderate injury, both A91 andCop-1 eliciteda pattern of genes characterized by a significant reduction of IL6, IL1β,andTNFα but an increase in IL10, IL4, and IGF-1expression. There was no effect on IL-12 and INFɣ. In contrast, the opposite pattern was observed when rats were subjected to a severe spinal cord contusion. Immunization with either peptide caused a significant increase in the expression of IL-12, IL-1β, IFNɣ, (pro-inflammatory genes), and IGF-1. There was no effect on IL-4 and IL-10 compared to controls. After a moderate SCI, IND Preduced pro-inflammatory gene expression, and generated a microenvironment prone to neuroprotection. Nevertheless, severe injury elicits the expression of pro-inflammatory genes that could be aggravated by INDP. These findings correlate with our previous results demonstrating that severe injury inhibits the beneficial effects of protective autoimmunity.