PTEN Mediated NR2B-Tyr Signal Pathway Involved In Maintaining Mechanism Of Rats With Chronic Migraine

Migraine is one of the most common neurological disease, which canbe disabling, and may seriously affect the quality of life of patients, itdisplays sensory hypersensitivity in the period of onset, characterized byspontaneous pain, hyperalgesia and allodynia. Chronic migraine isgenerally from episodic migraine after a few months to several yearsevolved, its pathological progress can be explain with central sensitization,electrophysiological and imaging studies have shown that the occurrence ofchronic migraine is associated with the progressive abnormal changes ofbrain stem. Many studies have suggest that chronic migraine central highsensitivity is mediated by NMDAR-NOS-NO.N-methyl-D-aspartate receptor(NMDAR)is a type of excitatoryneurotransmitter glutamate receptors, belong to the ionic receptor, itswidely distributed in central nervous system, which plays an important rolein the neurons signal transmission and regulation of gene expression, it alsothe main regulators of synaptic plasticity and enhances long termpotentiation of the cortex and hippocampus.NMDAR is made up of NR1, NR2A-D and NR3A-a total of seven kinds subunit of four polymers, inwhich requires the functional subunits of NR1, NR2and NR3is regulatorsubunits.Moreover, NR2Including NR2A, NR2B, NR2C and NR2D fourkinds subunits, mong them NR2B receptor subtypes also play a key role inthe formation of pain and central pain sensitization and chronic migraine.In virtue of NMDAR channel activity mediated by protein kinase andphosphorylation, so it is possible that the maintain of chronic migrainemediated by NR2B phosphorylation which in brainstem trigeminal caudate.NO is a medium molecular which play a critical role in a migraineattack, can make all levels of neurons in the trigeminal system activation,including the spinal nucleus of trigeminal nerve in brain stem the bodydonors of NO contain calcium/structural type NOS(eNOS, nNOS)depended on calmodulin and induction type NOS(inducible NOS.INOS)with do not rely on the calcium. Drip on the dura with nitroglycerin, theexogenous NO donor, can cause rat trigeminal spinal nucleus neurons inlate onset discharge,whereas in the central nervous system in vivo, thesynthesis of NO mainly associated with the release of glutamic acid, NRactivated by the releasing glutamic acid, then it prompts the calcium influx,when the concentration of calcium reaches400nm in cytoplasm, willactivate the nNOS, accerlarating the generation of NO neurons,causemigraines in the end.Homologous lost sexual tension protein phosphatase gene on chromos ome10(phosphatase and tensin homology does on chromosome ten, PTEN)is a newly discovered tumor suppressor genes with lipid and protein phosphatase activity, which is widely distributed in central nervous system. Itnot only plays an important role in the development and functioning of the nervous system maintenance, but are closely related with cerebral ischemia, epilepsy,drug addiction and other neurological disorder disease. Studies have found that lowered PTEN plays a protective role on the neuron injury induced by glutamate through NMDAR, but PTEN gene affecting the pathological process of chronic migraine by adjusting the NR2B phosphorylation, has yet to see the reports.In this study on the basis of the known NR2B–Tyr/NOS/NO pathway is likely to be one of the chronic migraine pathogenesis and chronic migraine’s central sensitization mainly occurs in the spinal nucleus of trigeminal nerve. We use RNAi recombinant adenovirus(AdR-siPTEN)to cut of PTEN gene in spinal nucleus of trigeminal nerve on migraine rat model, to observe the influence of the behavior of chronic migraine rats, and to study the effects of PTEN can influence the synthesis of NO through adjusting the NR2B-Tyr, then suppress the maintenance of chronic migraine.Materials and methods1Animal grouping and processing: Clean level adult male Sprague-Dswley(SD)rats as experimental object, were randomly divided into four groups.2The levels of PETN mRNA expression in rat trigeminal spinal nucleus were detected by semi-Quantitative RT-PCR.3The levels of PETN、NR2B-Tyr expression in rat trigeminal spinal nucleus were measured with Western-blot.4NOS assay kits, determine the content of NOS and NO in each group within the spinal nucleus of trigeminal nerve tissue.Results1Behavior and pain threshold results:In comparison to thecontrol group and the control intervention group, rats model of intervention group has no obvious behavior changes(P>0.05), model groupappears obvious behavior changes by comparison with the control and the control intervention group(P<0.05),besides,model of interventiongroup has obvious behavior changes in contrast to model group(P<0.05).As well as the results of behavior,The pain threshold results hasthe samechanges.2Followed by Transfection with adenovirus in rats one week,the ratspinal nucleus of trigeminal nerve tissue appears positive expression of redfluorescent protein.3The levels of PETN mRNA expression in rat detected bysemi-Quantitative RT-PCR has shown that by comparision to the controlgroup, The levels of PETN mRNA expression has no obviousdifference(P>0.05).Compared with the controll intervention group,PTENmRNA expression also has no clear difference in the model of interventiongroup(P>0.05).With significant difference(P<0.05),the controll intervention group elicited a47.53%reduction in the levels of PTEN mRNA expressionby comparision to the control group. while in the model of interventiongroup the levels of PTEN mRNA expression reduced by approx.46.87%incontast to the model group.4Protein expression of PTEN was consistent with The levels of PETNmRNA expression in each group.Compared with the model group, theprotein expression of NR2B-Tyr was significantly downregulated(p<0.05)in the model of intervention group, but there is nostatistical significance between the model of intervention group and thecontrol group. Compared with the control group,the protein expression ofNR2B-Tyr was also significantly down regulated(p<0.05)in the controllintervention group.5The NO content in spinal trigeminal nucleus was consistent with thelevels of the protein expression of NR2B-Tyr in each group.Conclusion1NR2B-Tyr protein expression and the content of NOS andNO significantly increased in trigeminal spinal nucleus in the rat modelwith chronic migraine.2PTEN mRNA and protein expression decreased significantly intrigeminal spinal nucleus in the rat model with chronic migraine aftertransfection AdR-siPTEN,NR2B-Tyr protein expression significantlyreduced,the content of NOS and NO decreased significantly,shown thatlower the gene of PTEN has certain protective effect on chronic migraine rats.