Analysis of Chemokines and Receptors Expression Profile in the Myelin Mutant Taiep Rat

Taiep rat has a failure in myelination and remyelination processes leading to a state of hypomyelination throughout its life. Chemokines, which are known to play a role in inflammation, are also involved in the remyelination process. We aimed to demonstrate that remyelination-stimulating factors are altered in the brainstem of 1- and 6-month-old taiep rats. We used a Rat RT(2) Profiler PCR Array to assess mRNA expression of 84 genes coding for cytokines, chemokines, and their receptors. We also evaluated protein levels of CCL2, CCR1, CCR2, CCL5, CCR5, CCR8, CXCL1, CXCR2, CXCR4, FGF2, and VEGFA by ELISA. Sprague-Dawley rats were used as a control. PCR Array procedure showed that proinflammatory cytokines were not upregulated in the taiep rat. In contrast, some mRNA levels of beta and alpha chemokines were upregulated in 1-month-old rats, but CXCR4 was downregulated at their 6 months of age. ELISA results showed that CXCL1, CCL2, CCR2, CCR5, CCR8, and CXCR4 protein levels were decreased in brainstem at the age of 6 months. These results suggest the presence of a chronic neuroinflammation process with deficiency of remyelination-stimulating factors (CXCL1, CXCR2, and CXCR4), which might account for the demyelination in the taiep rat.