RESUMEN
Defects in autophagy-mediated clearance of α-synuclein may be one of the key factors leading to progressive loss of dopaminergic neurons in the substantia nigra. Moxibustion therapy for Parkinson's disease has been shown to have a positive effect, but the underlying mechanism remains unknown. Based on this, we explored whether moxibustion could protect dopaminergic neurons by promoting autophagy mediated by mammalian target of rapamycin (mTOR), with subsequent elimination of α-syn. A Parkinson's disease model was induced in rats by subcutaneous injection of rotenone at the back of their necks, and they received moxibustion at Zusanli (ST36), Guanyuan (CV4) and Fengfu (GV16), for 10 minutes at every point, once per day, for 14 consecutive days. Model rats without any treatment were used as a sham control. Compared with the Parkinson's disease group, the moxibustion group showed significantly greater tyrosine hydroxylase immunoreactivity and expression of light chain 3-II protein in the substantia nigra, and their behavioral score, α-synuclein immunoreactivity, the expression of phosphorylated mTOR and phosphorylated ribosomal protein S6 kinase (p-p70S6K) in the substantia nigra were significantly lower. These results suggest that moxibustion can promote the autophagic clearance of α-syn and improve behavioral performance in Parkinson's disease model rats. The protective mechanism may be associated with suppression of the mTOR/p70S6K pathway.
RESUMEN
OBJECTIVE: To observe the action of electroacupuncture (EA) intervention on the expression of gap junction protein connexin 43 (Cx 43) and content of glutamate (Glu) in the striatum in Parkinson's disease (PD) rats, so as to reveal its mechanism underlying improvement of PD. METHODS: Forty male SD rats were randomly divided into normal control, sham operation, model and EA groups (n = 10 in each group). The PD model was duplicated by microinjection of 6-hydroxyldopamine (6-OHDA, 15 µg/rat) into the right striatum of rats (AP: 1.0, 1.0; R: 3.0, 4.5; H: 4.5, 6.0), and for control, the same dose of normal saline was injected into the right striatum for rats in the sham operation group. EA (2 Hz, 1 mA) was applied to "Fengfu" (GV 16) "Taichong" (LR 3) for 30 min, once a day for 2 weeks. The PD rats' rotational behavior changes (the numbers of rotations in 30 min) were detected following subcutaneous injection of apomorphine (0.5 mg/kg). The Glu concentration and the expression of Cx 43 in the striatum were detected by using high performance liquid chromatography (HPLC) and Western blot, respectively. RESULTS: No significant differences were found between the model group and EA group in the number of rotations before the treatment, between the control and sham operation groups in the levels of Glu content and Cx 43 protein expression in the striatum (P > 0.05). Compared with the control group, the Glu content and Cx 43 protein expression level were significantly increased in the model group (P < 0.01), while in comparison with the model group, the number of rotations was significantly reduced in the EA group (P < 0.05). Following EA intervention, both Glu content and Cx 43 expression were considerably down-regulated in the EA group compared with the model group (P < 0.05, P < 0.01). CONCLUSION: EA can improve PD rats' rotation behavior, which may be associated with its effects in down-regulating the level of Glu and Cx 43 protein expression in the striatum.
