Identification and distribution of rRNH1, a gene upregulated after spinal cord primary neuron injury.

Our previous study identified and characterized one differentially expressed gene, Rattus norvegicus ribonuclease/angiogenin inhibitor 1 (rRNH1). Transcriptional activity of lots of genes involves in spinal cord injury (SCI) and regeneration, but the mechanisms remain unknown. In the present study, we analyzed the sequences of rRNH1 and examined the expression pattern of rRNH1 in different adult rat tissues. We found the sequences of rRNH1 show high homology to Homo sapiens ribonuclease/angiogenin inhibitor 1; it encoded a protein of 461 amino acid residues and contained 13 leucine-rich repeat motifs. Using real-time quantitative PCR (q-PCR), rRNH1 mRNA was widely expressed in adult rat tissues, especially in the central nervous system. Moreover, rRNH1 protein was found to be upregulated after SCI. Although the precise function of rRNH1 is unknown, its unique expression pattern and upregulation after SCI suggest that rRNH1 might be involved in the succeeding injury and/or regeneration processes of injured spinal cord. All these data make rRNH1 a new interesting start to study the mechanisms of SCI and neuron regeneration.