This study aimed to investigate the regulatory effect of electroacupuncture (EA) intervention on the protein kinase B (Akt)/mammalian target of rapamycin (mTOR)/hypoxia-inducible factor 1α (HIF-1α) signaling pathway in the hippocampal tissue of Alzheimer′s disease (AD) model mice and its effect on astrocytic glycolytic function, further exploring how EA ameliorates AD-related cognitive impairment.

Eighteen APP/PS1 mice were randomly divided into model, EA, and sham EA groups (n=6) using the random number table method. Six wild-type C57BL/6J mice served as the control group. The EA group received EA stimulation at acupoints "Shenshu" (BL23), "Baihui" (GV20), and "Zusanli" (ST36) (administered every other day, 20 min per session, for 4 weeks). The sham EA group received identical needle insertions at the same acupoints without electrical stimulation. The control and model groups were only restrained. Cognitive function was assessed using the Morris water maze and Y-maze spontaneous alternation tests. Hippocampal morphology was observed via hematoxylin and eosin staining. Hippocampal β-amyloid peptide 1-42 (Aβ1-42) deposition was detected using immunohistochemistry. HIF-1α protein expression, the p-Akt/Akt, and p-mTOR/mTOR ratios were measured using Western blotting. Pyruvate kinase M2 (PKM2) and lactate dehydrogenase A (LDHA) activities were quantified using enzyme-linked immunosorbent assay. Hexokinase (HK) activity and L-lactate content were determined using a colorimetric assay. Co-localization of LDHA with the astrocyte marker glial fibrillary acidic protein was quantitatively analyzed using immunofluorescence double-labeling combined with Pearson′s correlation coefficient.

Compared with the control group, the model group mice exhibited cognitive decline, as shown by prolonged escape latency (P < 0.01), reduced number of platform crossings, lower time spent in the target quadrant, and decreased spontaneous alternation accuracy (P < 0.01). The hippocampal neurons showed cell body swelling, deeper nuclear staining, enlarged intercellular spaces, and increased average optical density of Aβ1-42 (P < 0.01). The p-Akt/Akt and p-mTOR/mTOR ratios, as well as HIF-1α protein expression, were elevated (P < 0.01). PKM2, LDHA, HK, and L-lactic acid levels were significantly increased (P < 0.01), and the co-localization coefficient of LDHA with astrocytes was enhanced. Compared to the model group, the EA group of mice showed improved cognitive function. The hippocampal neurons had more intact structures, with a more uniform cell distribution. The average optical density of Aβ1-42 decreased (P < 0.01), and the p-Akt/Akt and p-mTOR/mTOR ratios, as well as HIF-1α protein expression, decreased (P < 0.01). PKM2, LDHA, HK, and L-lactic acid levels decreased (P < 0.05), and the co-localization coefficient of LDHA with astrocytes significantly decreased (P < 0.01). No significant improvement was observed in any of the indicators in the sham EA group compared with the EA group.

EA at "Shenshu" (BL23), "Baihui" (GV20), and "Zusanli" (ST36) ameliorates cognitive dysfunction in AD model mice. The underlying mechanism may involve suppressing the overactivation of the hippocampal Akt/mTOR/HIF-1α signaling pathway, thereby downregulating key glycolytic enzyme activities and reducing abnormal lactate accumulation. Furthermore, the astrocytic glycolytic metabolic pathway may constitute a key therapeutic target for this intervention.

To observe the effects on tyrosine hydroxylase (TH), α-synaptic nucleoprotein (α-syn), sirtuin 3 (Sirt3), NOD-like receptor 3 (NLRP3) and gasdermin-D (GSDMD) in the substantia nigra of midbrain after electroacupuncture (EA) at “Fengfu” (GV16), “Taichong” (LR3) and “Zusanli” (ST36) in rats of Parkinson’s disease (PD), so as to explore the mechanism of EA in treatment of PD.

SD rats were randomly divided into control, model and EA groups, with 10 rats in each group. The PD model was established by injecting rotenone into the neck and back, lasting 28 days. In the EA group, EA was applied to GV16, LR3 and ST36, 30 min each time, once daily, consecutively for 28 days. The open-field test was adopted to detect the total distance of autonomic movement of rats, and the pole climbing test was used to detect the body coordination ability of rats. In the substania nigra of midbrain, the positive expression of TH was determined using immunohistochemistry, the mRNA expression levels of α-syn, Sirt3, NLRP3 and GSDMD were detected by quantitative real-time fluorescence PCR, and the protein expression levels of NLRP3, apoptosis-associated speck-like protein containing a caspase-recruitment domain (ASC) and cysteinyl aspartate specific proteinase (Caspase)-1 were detected by Western blot.

Compared with the control group, the total distance of autonomous movement was decreased (P<0.01) in the model group, and the score of pole climbing experiment was increased (P<0.01); in the midbrain substantia nigra the positive expression of TH was decreased (P<0.01); the mRNA expression level of Sirt3 was decreased (P<0.01), and those of α-syn, NLRP3 and GSDMD were increased (P<0.01); while the protein expression levels of NLRP3, ASC and Caspase-1 were increased (P<0.01). When compared with the model group, the total distance of autonomous movement in open field experiment was increased (P<0.01) in the EA group and the score of pole climbing experiment was lower (P<0.05); in the midbrain substantia nigra the positive expression of TH was increased (P<0.01); the mRNA expression level of Sirt3 in the midbrain substantia nigra was increased (P<0.01), and those of α-syn, NLRP3 and GSDMD were reduced (P<0.01); while the protein expression levels of NLRP3, ASC and Caspase-1 decreased (P<0.01, P<0.05).

EA at “GV16” “LR3” and “ST36” can repair the neuronal injury, clear the abnormal accumulation of α-syn in the substania nigra of midbrain, and ameliorate mitochondrial damage in PD rats, which may be obtained by regulating Sirt3/NLRP3/GSDMD signaling pathway, so as to delay the occurrence and development of Parkinson’s disease.