Effect of electroacupuncture on TRPM7 mRNA Expression after cerebral ischemia/reperfusion in rats via TrkA pathway

Abstract

The effect of electroacupuncture (EA) on TRPM7 mRNA expression of focal cerebral ischemia in rats and further the role of EA in the relationship between TRPM7 and trkA pathway was investigated. Thirty SD rats were randomly divided into 5 groups: normal group, ischemia/reperfusion group, EA treated group (ischemic rats with EA treatment), TE infusion group (ischemic rats with EA treatment and TE buffer infusion), AS-ODN group (ischemic rats with EA treatment and antisense trkA oligonucleotide infusion). The stroke animal model was established by the modified method of middle cerebral artery occlusion. Antisense trkA oligonucleotide that blocked NGFs effects was injected into cerebroventricle before EA. The TRPM7 mRNA was detected by RT-PCR method. The results showed that there were low TRPM7 mRNA levels in cortex and hippocampus in normal group. Compared with normal group, TRPM7 mRNA expression was increased significantly in ischemia/reperfusion group (P<0.05). A significant reduction in the expression of TRPM7 mRNA was found in EA treated group in contrast to ischemia/reperfusion group (P<0.05). The expression of TRPM7 mRNA in AS-ODN group was remarkably increased compared with EA treated group and TE infusion group (P<0.05). The results indicated that TRPM7 channels in the ischemic cortex and hippocampus in rats might play a key role in ischemic brain injury. EA could reverse the overexpression of TRPM7 in cerebral ischemia/reperfusion rats. And the inhibitory effect of EA on TRPM7 channels might be through trkA pathway.

Keywords

TRPM7 / ischemia/reperfusion / electroacupuncture / antisense trkA oligonucleotide

References

[1] AartsM, IiharaK, WeiW L, et al.. A key role for TRPM7 channels in anoxic neuronal death. Cell, 2003, 115(7): 863-863

[2] ShiJ. A study on the effect and mechanism of acupuneture suppression of neuronal apoptosis following cerebral ischemia. Progress in Physiological Sciences, 1999, 30(4): 326-326

[3] ShiJ, LiuX C, ZhangJ, et al.. The influence of acupuncture on the NGF receptor—TrkA of focal cerebral ischemia in rats. Chinese Journal of Histochemistry and Cytochemistry, 1999, 8(2): 132-132

[4] LongaE Z, WeinsteinP R, CarlsonS, et al.. Reversible middle cerebral artery occlusion without craniectomy in rats. Stroke, 1989, 20(1): 84-84

[5] WoolfN J, MilovA M, SchweitzerE S, et al.. Elevation of recve grouth factor and antisense knockdown of TrkA receptor during contextual memory consolidation. J Neurosci, 2001, 21(3): 1047-1047

[6] JiangX, NewellE W, SchlichterL C, et al.. Regulation of a TRPM7-like current in rat brain microglia. J Biol Chem, 2003, 278(44): 42-42

[7] ShiJ, LiuX C, ZhangJ, et al.. The influence of acupuncture on the NMDAR1 mRNA after focal cerebral ischemia following reperfusion in brain of rats. Chinese Journal of Histochemistry and Cytochemistry, 2000, 9(4): 371-371

[8] HeurteuxC, LauritzenI, WidmannC, et al.. Glutamate-induced overexpression of NMDA receptor messenger RNAs and protein triggered by activation of AMPA/kainate receptors in rat hippocampus following forebrain ischemia. Brain Res, 1994, 659(1–2): 67-67

[9] HoltzmanD M, SheldonR A, JaffeW, et al.. Nerve growth factor protects the neonatal brain against hypoxic-ischemic injury. Ann Neurol, 1996, 39(1): 114-114

[10] KaplanD R, MillerF D. Neurotrophin signal transduction in the nervous system. Curr Opin Neurobiol, 2000, 10(3): 381-381