Electroacupuncture improves cognitive ability following cerebral ischemia reperfusion injury via CaM-CaMKIV-CREB signaling in the rat hippocampus

Abstract

Abstract. The aim of the present study was to investigate the effect of electroacupuncture (EA) on cognitive deficits, and the underlying mechanism following cerebral ischemia-reperfusion (I/R) via the calmodulin (CaM)-calmodulin-dependent protein kinase type IV (CaMKIV)-cyclic adenosine monophosphate response elements binding protein (CREB) intracellular signaling pathway in the hippocampus. In total, 45 adult female Sprague-Dawley rats were randomly divided into three groups, namely the sham group, the middle cerebral artery occlusion (MCAO) group and the MCAO + EA group. Rats in the MCAO and MCAO + EA groups were modeled for post-stroke cognitive impairment. EA was performed at the Baihui and Shenting acupuncture points for 30 min/day for one week in the MCAO + EA group. Behavioral testing was analyzed using a step-down apparatus, while 2,3,5-triphenyl tetrazolium chloride was used to detect the infarct volume and lesion size. In addition, CaM activity was assessed by cyclic nucleotide-dependent phosphodiesterase analysis, and the protein expression levels of CaM, CaMKIV, phosphorylated (p)-CaMKIV, CREB and p-CREB were analyzed by western blot analysis. The cerebral I/R injured rat model in the MCAO group was established successfully with regard to the infarct volume and neuronal lesion size, as compared with the sham group. EA was demonstrated to effectively improve the cognitive ability, as measured by the step-down apparatus test, and decrease the infarct volume when compared with the MCAO group (P<0.05). The step-down apparatus test for the EA-treated rats revealed improved learning and reduced memory impairment when compared with the MCAO group. Furthermore, CaM activity and CaM protein expression levels in the MCAO + EA group were lower compared with those in the MCAO group (P<0.05). By contrast, the protein expression levels of CaMKIV, p-CaMKIV, CREB and p-CREB were significantly reduced in the MCAO group when compared with the sham group (P<0.05), although the expression levels increased following EA treatment when compared with the MCAO group (P<0.05). Therefore, cognitive repair benefited from EA, and the main intracellular signaling pathway in the hippocampus was mediated by CaM-CaMKIV-CREB. EA effectively inhibited the expression and activity of CaM, while further enhancing the expression of CaMKIV and CREB, and their associated phosphorylated functions.

Mechanisms of Acupuncture Therapy in Ischemic Stroke Rehabilitation: A Literature Review of Basic Studies

“…The second paper, a Cochrane review of the efficacy and safety of acupuncture therapy in subacute or chronic ischemic or hemorrhagic stroke, concludes that acupuncture may improve global deficiency and some specific neurological impairments, with no obvious serious adverse sequelae, although most included trials were of limited quality and size [ 66 ]. Still further support is provided by the results and conclusions of four preclinical studies published in 2016, all of which demonstrate that EA improves neurological function after cerebral ischemia/reperfusion injury in rats [ 67 , 68 , 69 , 70 ].…”

The effect of different frequencies of electroacupuncture on BDNF and NGF expression in the hippocampal CA3 area of the ischemic hemisphere in cerebral ischemic rats

“…Numerous basic experimental studies have shown that EA can improve the learning and memory abilities of rats with cerebral ischemia. 26 – 28 EA treatment can enhance the expression of endogenous BDNF, thereby improving the environment to enhance survival of intracerebral neurons and inhibiting hippocampal cell apoptosis. 29 EA treatment can improve brain NGF availability and action, 30 EA stimulation can upregulate cerebral NGF expression in cerebral ischemia rats.…”

Developmental alterations in Huntington's disease neural cells and pharmacological rescue in cells and mice

“…Approximately 15 μg of protein was loaded into NuPAGE 4–12% Bis-Tris protein gels (ThermoFisher, cat# NP0321BOX), separated with 200 V for approximately 1 h, and electrotransferred to PVDF membrane in the XCell II Blot Module for wet (tank) transfer (ThermoFisher) for 90 min at 30 V. The membrane was blocked in 5% non-fat dry milk in TBS buffer, pH 7.4 (Quality Biological, cat# 351-086-101) plus 0.1% Tween 20 (Sigma-Aldrich) for 1 h at room temperature and then exposed to primary antibodies. Antibodies for detection of NEUROD1, CALB1, and CAMKIV were purchased from Cell Signaling: NeuroD (D90G12) rabbit mAb: cat# 7019, 1:1,000 dilution (for WB validation, see https://www.cellsignal.com/products/primary-antibodies/neurod-d90g12-rabbit-mab/7019); Calbindin (D1I4Q) XP rabbit mAb: cat# 13176, 1:1,500 dilution (for WB validation and references, see https://www.cellsignal.com/products/primary-antibodies/calbindin-d1i4q-xp-rabbit-mab/13176?_=1487290902164&Ntt=13176&tahead=true) 80–82 ; CaMK IV: rabbit, cat# 4032, 1:1,000 dilution (for WB validation and references, see https://www.cellsignal.com/products/primary-antibodies/camkiv-antibody/4032; Product Citations) 83,84 . Equal loading was verified by western blotting of actin (α-actin: 1:10,000, mouse, Sigma-Aldrich, clone AC-15, cat# A5441; for WB validation see http://www.sigmaaldrich.com/catalog/product/sigma/a5441?lang=en&region=US).…”