[Effect of electroacupuncture on proliferation and differentiation of neural stem cells in the subependymal zone of the cerebral lateral ventricle in rats with hyperlipemia and cerebral ischemia]

Abstract

Objective: To observe the effects of electroacupuncture (EA) on the expression of vimentin and beta-Tubulin (Tju-1) in the dorsolateral extension and the lateral wall of the lateral ventricle (both of which belong to the subependymal ventricular zone, SVZ) on the ischemic side of the brain in rats with hyperlipemia (HL) plus cerebral ischemia (CI) so as to study its underlying mechanism in relievting HL, CI and combined HL and CI by regulating the proliferation and differentiation of neural stem cells.

Methods: Seventy two male SD rats were randomized into control, HL, HL + EA, CI, CI + manual acupuncture (MA), HL + CI, HL + CI + EA I and HL + CI + EA II groups, with 9 cases in each. HL model was established by feeding the animals with high fat forage for 6 weeks and CI model was duplicated by occlusion of the unilateral middle cerebral artery induced by regional application of FeCl3. For rats of HL+ EA group, EA (15 Hz, 1 - 3 mA) was applied to bilateral "Sanyinjiao" (SP 6) and "Fenglong" (ST 40) for 20 min, once daily for 17 days. For rats of CI+ MA group, "Baihui" (GV 20) and "Shuigou" (GV 26) were punctured and stimulated manually for 1 min (the former with the needle retained for 20 min), once daily for 7 days. For rats of HL+ CI + EA I group, bilateral "Sanyinjiao" (SP 6) and "Fenglong"(ST 40) were stimulated electrically after needle-insertion, once daily for 10 days, followed by duplicating CI model and performing MA stimulation of GV 20 and GV 26 respectively, once daily for 7 days. For rats of HL + CI + EA II groups, EA was applied to bilateral SP 6 and ST 40, and simultaneous MA stimulation of GV 20 and GV 26, once daily for 7 days after HL + CI. The expression of vimentin and Tuj-1 in the dorsolateral extension and the lateral wall of the cerebral lateral ventricle on the ischemic side was detected by immunohistochemistry.

Results: Compared with the control group, the expression levels of both vimentin and Tuj-1 in the dorsolateral extension and the lateral wall of the lateral ventricle of the brain on the ischemic side were increased significantly in the CI and HL + CI groups (P < 0.01), while compared with the CI group, the expression of vimentin and Tuj-1 in the CI + MA group were increased further significantly (P < 0.01). In comparison with the HL + CI group, the expression of vimentin and Tuj-1 in the HL + CI + EA I and HL + CI + EA II groups were also upregulated considerably (P < 0.01). Comparison between the HL + CI + EA I and HL + CI + EA II groups showed that the expression levels of vimentin and Tuj-1 were significantly lower in the latter group than in the former group (P < 0.01). No significant diffrences were found between the HL and control groups, and between the HL and HL+ EA groups in the expression of vimentin and Tuj-1 (P > 0.05).

Conclusion: Acupuncture and Acupuncture + EA can further significantly upregulate the expression levels of vimentin and Tuj-1 in both the dorsolateral extension and the lateral wall of the cerebral lateral ventricle on the ischemic side in rats with CI and CI + HL, which may contribute to their effects in improving CI and HL+CI by suppressing the reduction of proliferation and differentiation of neural stem cell in the SVZ of the ischemic brain induced by CI and HL+ CI.