["Shugan Tiaoshen" needling regulates lipid oxidative stress and inhibits ferroptosis of prefrontal neurons to improve post-stroke depression].

Abstract

Objectives: To observe the effect of "Shugan Tiaoshen" needling (Smoothing the Liver and Regulating the Spirit) on antioxidant and lipid peroxidative stress in prefrontal cortex of rats with post-stroke depression (PSD), so as to explore its mechanism in inhibiting ferroptosis of PSD neurons.

Methods: Sixty-four male SD rats were randomly divided into normal, sham operation, model, electroacupuncture (EA) and medication groups (12 rats in each group). The PSD model was established by occlusion of the middle cerebral artery and reperfusion (MCAO/R), combined with chronic unpredictable mild stimulation (CUMS). EA was applied to "Baihui" (GV20), "Yintang" (GV24⁺), bilateral "Hegu" (LI4), and "Taichong" (LR3) for 30 min, once daily for 14 d. Rats in the medication group were given paroxetine intragastatically (10 mg/kg) once a day for 14 d. Neurologic impairment was assessed by Zea-Longa score. Behavioral assessment of depression was conducted by sucrose preference test and open field test. The pathologic changes of prefrontal cortex were observed by HE staining. The ultrastructure and mitochondrial morphology of prefrontal neurons were observed by transmission electron microscopy (TEM). Iron ion content in prefrontal cortex was detected by iron ion kit. The contents of glutathione (GSH) and malonicdialdehyde (MDA) in prefrontal cortex were determined by ELISA. Western blot and qPCR were used to detect the protein and mRNA expression levels of glutathione peroxidase 4 (GPX4), solute carrier family 7 member 11 (SLC7A11), lipoxygenase (LOX), lysophosphatidylcholine acyltransferase 3 (LPCAT3), and acyl-CoA synthetase long chain family member 4 (ACSL4) in prefrontal cortex.

Results: Compared with the sham operation group, the sucrose preference rate, the number of crossings in the central area, the total duration of staying in the central area, and the total distance of activity were all significantly decreased (P<0.05), the iron ion content, MDA content, and the protein and mRNA expression levels of LOX, LPCAT3, and ACSL4 were increased (P<0.05), while the GSH content, the protein and mRNA expression levels of GPX4 and SLC7A11 were decreased (P<0.05) in the model group. Following interventions, the above-mentioned indexes were all reversed in the EA and medication groups (P<0.05). There were no significant differences in the above indexes between the normal group and the sham operation group, the EA group and the medication group. TEM showed unevenly distributed neurons, with an irregular triangular shape, condensed and deeply stained nuclei, and typical ferroptosis-changed mitochondria in the model group, which were relatively milder in the EA and medication groups.

Conclusions: "Shugan Tiaoshen" needling can improve the depressive symptoms of ischemic PSD rats, and its mechanism may be related to activating the prefrontal antioxidant system, inhibiting lipid peroxidative and iron death, thus playing a protective role in neurons.