RESUMEN
Objective: To observe the effects of electroacupuncture (EA) on the protein and gene expressions of Bax, Caspase-3 and Bcl-2 in cerebral cortex of type 2 diabetic rats with cognitive impairment (CI), and to explore the mechanism of EA in improving the learning and memory abilities. Methods: A total of 100 Sprague-Dawley (SD) rats were divided into a normal group (n=10) and a model group (n=90) by random number table method. Rats in the model group were intraperitoneally injected with a small dose of streptozotocin (STZ) to establish the type 2 diabetic models, after being fed with high-fat and high-sugar diet for 1 month. Twenty CI rats were selected from the 50 successful model rats by the Morris water maze (MWM) test and randomly divided into a model group and an EA group according to the blood glucose level and MWM data (n=10). Rats in the EA group received acupuncture at Zusanli (ST 36), Neiting (ST 44) and Yishu (Extra), of which Zusanli (ST 36) and Neiting (ST 44) were stimulated by EA apparatus, 20 min/time, once a day for 6 d a week and 4 consecutive weeks. The rats in the model and the normal groups were fixed without treatment. After 4-week treatment, the random blood glucose level of the rats was measured; the learning and memory abilities of rats were measured by MWM; terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay was used to detect apoptotic cells; Western blot (WB) and real-time quantitative polymerase chain reaction (RT-qPCR) were used to detect the protein and gene expressions of Bax, Caspase-3 and Bcl-2 in cerebral cortex. Results: After modeling, the random blood glucose level and the escape latency tested by MWM were significantly increased, and the number of crossing the platform tested by the MWM was decreased in the EA and model groups, and were significantly different from those in the normal group (P<0.05 or P<0.01), while the differences between the model group and the EA group were not statistically significant (all P>0.05). After 4-week treatment, the random glucose level and the escape latency tested by MWM were significantly increased (both P<0.05), and the number of crossing the original platform tested by the MWM was significantly reduced (P<0.01), the protein and gene expressions of Bax and Caspase-3 were significantly increased (all P<0.001), the protein and gene expressions of Bcl-2 were significantly reduced (both P<0.001), and the number of neuron apoptosis was significantly increased (P<0.001) in the model group than in the normal group; the random blood glucose level was significantly reduced (P<0.05), the escape latency tested by MWM was significantly shortened (P<0.05), and the number of crossing the original platform tested by MWM was significantly increased (P<0.05), the protein and gene expressions of Bax and Caspase-3 were significantly reduced (all P<0.001), the protein and gene expressions of Bcl-2 were significantly increased (both P<0.001), and the number of neuron apoptosis was significantly reduced (P<0.001) in the EA group than in the model group. Conclusion: EA can improve the learning and memory damages induced by type 2 diabetic model rats with CI; the action mechanism may be achieved via anti-apoptosis.
RESUMEN
Objective:To observe the effect of acupuncture in regulating ubiquitin-proteasome pathway (UPP),and discuss the action of acupuncture in intervening heroin-induced brain damage.Methods:Thirty male Sprague-Dawley (SD) rats were divided into a control group,a model group and an acupuncture group by using the random number table.Rats in the model and acupuncture groups received intramuscular heroin injection for successive 8 d at a progressively increased dose.Afterwards,the injection was suspended for 5 d for withdrawal.The heroin relapse rat model was established by repeating the drug addiction and withdrawal process for 3 times.The control group followed the step of the model establishment,but was given intramuscular injection of normal saline at the stage of addiction and no intervention at the stage of withdrawal;the model group was given intramuscular heroin injection at a progressively increased dose at the addiction stage and no intervention at the withdrawal stage;the acupuncture group was dealt in the same way as the model group at the addiction stage,but received acupuncture at Baihui (GV 20) and Dazhui (GV 14) at the withdrawal stage,with the needles retained for 30 min each time,1 session a day,for successive 5 d.On the 39th day,brain tissues were extracted from the hippocampus and ventral tegmental area (VTA) of the three groups of rats.The apoptosis of brain nerve cells was detected by using terminal deoxynucleotidyl transferase-mediated nick and labeling (TUNEL).The mRNA and protein expressions of ubiquitin (Ub),ubiquitin protein ligase (E3) and 26S were examined by immunohistochemistry and quantitative real-time polymerase chain reaction (RT-qPCR).Results:Compared with the model group,rat's hippocampus and VTA in the acupuncture group showed significantly fewer cells positively stained by TUNEL staining (P<0.01),and its mRNA and protein expressions of Ub,E3,26S were significantly lower (P<0.01).Conclusion:Reducing nerve cell apoptosis and regulating the mRNA and protein expressions of Ub,E3 and 26S in rat's hippocampus and VTA are possibly one of the action mechanisms of acupuncture in intervening heroin-induced brain damage.