Regulation of mitochondrial autophagy via the PINK1/Parkin pathway to improve cognitive function in vascular dementia using governor vessel acupuncture.

Background: As a common cognitive impairment disease, vascular dementia (VD) belongs to the category of "dementia" in Chinese medicine, and should be treated with the principle "Governor Vessel" as the primary focus. The occurrence of VD is closely related to cerebral ischemia, hippocampal neuron damage, and excessive mitochondrial autophagy activation, which has been considered as is a key mechanism of PINK1/Parkin signaling pathway regulation. Our study aims to investigate molecular mechanisms of the Governor Vessel acupuncture method in improving VD cognitive dysfunction by regulating mitochondrial autophagy.

Methods: The study utilized 310 healthy adult male Sprague-Dawley (SD) rats (SPF-grade, aged 18 months, weighing 500-700 g). Vascular dementia (VD) model was established using permanent bilateral common carotid artery ligation (2VO). Additionally, adenoviral vector intervention and drug intervention groups were set up to explore the mechanistic pathways. Morris water maze and shuttle box tests were used to assess cognitive function. Hippocampal tissue changes were analyzed through Nissl staining, HE staining, TUNEL (cell apoptosis), JC-1 (mitochondrial membrane potential), qPCR, and Western blot (to detect PINK1/Parkin pathway proteins). Data are presented as mean ± SEM, analyzed by one-way ANOVA (for normal distribution) or Friedman test (for non-normal distribution), with Tukey's post-hoc test. p < 0.05 was considered statistically significant.

Results: Rats in the VD model group showed significant cognitive decline in behavioral evaluations, while neurons in the hippocampal CA1 region exhibited varying degrees of damage and apoptosis. Besides, the expressions of autophagy-related proteins, Beclin-1, p-Parkin/Parkin, PINK1, and LC3 II/I was notably up-regulated, whereas the expression of p62 and Mfn2 proteins was significantly decreased. After governor vessel acupuncture, the cognitive ability of VD rats was improved significantly, and neuronal damage in hippocampal CA1 region was effectively alleviated, indicating that governor vessel acupuncture inhibited autophagy by down-regulating the PINK1/Parkin signaling pathway, thereby alleviating VD. Further, PINK1 viral vector and drug intervention experiments further confirmed that inhibiting autophagy could effectively protect neurons by down-regulating the PINK1/Parkin signaling pathway.

Conclusion: Governor vessel acupuncture can effectively protect hippocampal neurons and enhance cognitive functions in VD models by down-regulating PINK1/Parkin signaling pathway to inhibit mitochondrial autophagy, providing a theoretical basis for its clinical application.