The Study Of Epilepsy-related MiR-246and MiR-357-358Based On Epilepsy Model In C.elegans

Epilepsy is a common neurological diseases, which is characterized by the electrical disturbances of brain. It is still limited to identify the genes involved in epilepsy now. Some evidences have showed that some miRNAs are particularly enriched in the nervous system, and some of them are related to regulating synaptic plasticity. However, it is unclear that if miRNAs are involved in epilepsy. C.elegans is a good model in neurons study, because its nervous system is very simple, and it has70%homology genes about singal pathways and disease in human. Now various miRNAs mutant strains can be obtained from the library in Caenorhabditis Genetics Center. Therefore, C.elegans becomes an ideal model to study the miRNAs related to epilepsy.PTZ(pentylenetetrazole) is the GABA(gamma-aminobutyric acid) antagonist. It has been reported that PTZ can induce epilepsy-like convulsion in some mutant worms. Based on this, we first established a system for screening the genes involved in PTZ-induced epilepsy in our study. In this system, we assayed the percentage of the convulsive worms with10mg/mL PTZ treatment for30min. The Wild-type worm N2is as the negative control, and unc-25mutant worm is as the positive control. Then, the two miRNAs, miR-246and miR-357-358, were identified to be related to PTZ-induced epilepsy from12miRNAs mutant worms by our system. Aldicarb is an acetylcholinesterase inhibitor. It has been known that aldicarb can induce some mutant worms to paralyze, because of the excessive accumulation of ACh at neuromuscular junctions(NMJs), which is one of the reason for epilepsy. Next, we found that the percentage of paralyzed mir-246and mir-357-358mutant worms was more than that in wild-type worm N2with1mM aldicarb treatment for90min. This result confirmed that miR-246and miR-357-358are epilepsy-related genes.In order to know the target genes for miR-246and miR-357-358, we first predicted their target genes by three kinds of software, including Pictar, Targetscan and miRBase. Then, rgs-1and pop-1were selected for further study, because they both expressed widely in the nervous system and are reported to be associated to epilepsy. Last, by RT-PCR, we found that the mRNA expression level of rgs-1in mir-246mutant worm is similar to that in wild-type N2. But, the mRNA level of pop-1was increased in mir-357-358mutant worm, compared to N2. This suggested that pop-1may be the target gene of miR-357-358.