Acupuncture Improves Chronic Cerebral Ischemia by Inhibiting the CKLF1/HIF‐1α/VEGF/Notch1 Signaling Pathway

Acupuncture significantly improves cognitive dysfunction in rats with chronic cerebral ischemia. However, the underlying signaling pathways remain unclear. This study investigates the role of the CKLF1/HIF-1α/VEGF/Notch1 signaling pathway in the acupuncture-mediated improvement of cognitive function in rats with chronic cerebral ischemia. Male SD rats were randomly divided into the normal control group, sham-operated group, 2-VO model group, 2-VO + acupuncture group, and 2-VO + Ginaton group (Ginkgo biloba extract 14.4 mg/kg/day), with 10 rats in each group. The 2-VO + acupuncture group received acupuncture at the Shuigou, Baihui, bilateral Fengchi, and bilateral Zusanli points for 14 consecutive sessions over 2 weeks. The rats' memory function was assessed using the Morris water maze and novel object recognition tests. Cerebral blood volume changes were measured using laser speckle imaging. Ultrastructural changes in microvessels were observed via transmission electron microscopy. Neuronal and myelin alterations were evaluated using HE staining, Nissl staining, and LFB myelin staining. The expression levels of CKLF1, CCR5, HIF-1α, VEGF, and Notch1 proteins were measured using Western blot, and multiple immunofluorescence staining was performed to assess the colocalization of CKLF1 and neurons. Compared with the 2-VO model group, acupuncture treatment reduced the latency period and increased the number of platform crossings in the Morris water maze test, and the 2-VO model group had a higher recognition index in the novel object recognition test. We found that acupuncture improved the condition of endothelial cells, repaired the morphology of the vascular lumen, and alleviated astrocyte edema. We also showed that acupuncture could ameliorate pathological damage in rats with chronic cerebral ischemia. Moreover, acupuncture reduced the expression of CKLF1, CCR5, and HIF-1α proteins in the hippocampus, decreased the fluorescence intensity of CKLF1 expression, and increased the fluorescence intensity of neurons in the hippocampal CA1 region. Acupuncture may exert neuroprotective effects and improve cognitive dysfunction caused by chronic cerebral ischemia by regulating the CKLF1/HIF-1α/VEGF/Notch1 pathway to inhibit inflammatory factors and increase cerebral blood flow.