ارزیابی بیان ژن مولکول های متالوتیونین پس از آسیب عصب سیاتیک

Background and purpose: Injury to peripheral nerve causes widespread cellular and molecular changes in injured neurons, however, the mechanisms involved remain unknown. One of these changes is increased production of free radicals that causes oxidative stress. Antioxidants participate in nerve repair through the scavenging effect of oxygen free radicals. In this research we studied gene expression of metallothionein 1 and 2 molecules after sciatic nerve crush in rats. Materials and methods: The sciatic nerve of 40 adult Wistar rats was crushed. In day 1 and 3 and week 1, 3, and 5 after injury the sciatic crushed nerves were extracted. Total mRNA of samples was extracted and then cDNA was synthesized. The expression of metallothionein 1and 2 genes was confirmed using semiquantitative RT-PCR (Reverse Transcription-Polymerase Chain Reaction) analysis. For immunohistochemistry analysis the samples were fixed in paraformaldehyde and cut in 20 micrometer slices by cryostat. Results: The results showed that the expression of metallothionein was significantly higher in day 1 and 3 after crush injury compared with that of the intact (non-injured) nerves (P<0.0001). Immunohistochemistry results also confirmed the protein expression of these genes. Conclusion: The sciatic nerve injuries cause oxidative stress. This research found maximum up-regulation of metallothionein molecules in regeneration process, when oxidative stress have maximum peak and with more studies it may suggest as new complemental treatment.