Neuroprotective effect of α7nAChR on PD rat models and its underlying mechanism
10.3760/cma.j.cn115354-20250309-00127
- VernacularTitle:α7nAChR对PD模型大鼠的神经保护作用及机制研究
- Author:
Yan PAN
1
;
Xin HU
1
;
Jing PEI
1
;
Shujie TONG
1
Author Information
1. 新疆医科大学第五附属医院神经内科，乌鲁木齐 830011
- Publication Type:Journal Article
- Keywords:
Parkinson's disease;
α7nAChR;
Ferroptosis;
CAMKII/ERK pathway
- From:
Chinese Journal of Neuromedicine
2025;24(6):561-571
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To explore the neuroprotective effect of α7 nicotinic acetylcholine receptor (α7nAChR) on rat models of Parkinson's disease (PD) and its underlying mechanism.Methods:Forty-eight 8-week-old SPF-grade SD rats were randomly divided into a normal control group, a PD model group, an α7nAChR empty vector group and an α7nAChR overexpression group, with 12 rats in each group. PD models in the latter 3 groups of rats were established by 6-hydroxydopamine (6-OHDA). Four weeks after modeling, rats in the latter 2 groups were injected with 2 μL α7nAChR overexpression lentivirus or empty vector lentivirus through stereotactic intracerebral injection, while rats in the normal control group did not receive any treatment. Two weeks after injection, the behavioral changes of these rats were detected by apomorphine-induced rotation test; the right substantia nigra pars compacta (SNc) was prepared and performed the following experiments: hematoxylin-eosin (HE) staining and Nissl staining were used to detect the neuron morphological changes, TUNEL was used to detect the neuron apoptosis, fluorescent double labeling was used to detect the expressions of tyrosine hydroxylase (TH) and α-synuclein (α-Syn), ELISA was used to detect the expressions of 4-hydroxynonenal (4-HNE) and malondialdehyde (MDA), and Western blotting was used to detect the expressions of ferroptosis-related proteins (ferritin heavy chain 1 [FTH1], Sigma receptor 1 [S1R], glutathione peroxidase 4 [GPX4], long chain acyl-coa synthetase 4 [ACSL4], solute carrier family 7 member11 [SLC7A11]), and the expressions of proteins related to CAMKII/ERK pathway (phosphorylated calmodulin kinase Ⅱ [p-CAMK Ⅱ], phosphorylated extracellular signal regulated kinase [p-ERK], and phosphorylated Kirsten rat sarcoma viral oncogene homolog [p-KRAS]).Results:(1) Compared with the normal control group, the PD model group, α7nAChR empty vector group and α7nAChR overexpression group had significantly larger number of rotations ( P<0.05); compared with the PD model group, the α7nAChR overexpression group had significantly smaller number of rotations ( P<0.05). (2) HE staining and Nissl staining showed that the PD model group had decreased number of dopaminergic neurons and Nissl bodies, accompanied by neuronal distribution disorder, nuclear condensation or swelling; the α7nAChR-overexpression group had obviously improved appearance of dopaminergic neurons, with normal morphology and less cell degeneration. (3) TUNEL results showed that compared with the normal control group, the PD model group, α7nAChR empty vector group, and α7nAChR overexpression group had significantly higher apoptosis rate ( P<0.05); compared with the PD model group, the α7nAChR overexpression group had statistically lower apoptosis rate ( P<0.05). (4) Double immunofluorescent staining results showed that compared with the normal control group (303.61±48.40, 13 985.80±1 956.06), the PD model group, α7nAChR empty vector group and α7nAChR overexpression group had significantly increased α-Syn expression (4 310.40±518.43, 3 846.60±524.47 and 1 033.55±59.98) and statistically decreased TH expression (760.97±57.26, 842.55±113.41 and 8 101.82±1 171.85) in the right SNc ( P<0.05); compared with the PD model group, the α7nAChR overexpression group had significantly decreased α-Syn expression and increased TH expression in the right SNc ( P<0.05). (5) ELISA results showed that the 4-HNE and MDA expressions in the right SNc of the PD model group, α7nAChR empty vector group and α7nAChR overexpression group were significantly higher than those in the normal control group ( P<0.05); the 4-HNE and MDA expressions in the α7nAChR overexpression group were significantly lower than those in the PD model group ( P<0.05). (6) Western blotting results showed that compared with the normal control group, the PD model group, α7nAChR empty vector group and α7nAChR overexpression group had significantly decreased FTH1, S1R, GPX4, and SLC7A11 protein expressions, and statistically increased ACSL4 protein expression in the right SNc ( P<0.05); compared with the PD model group, the α7nAChR overexpression group had significantly increased FTH1, S1R, GPX4, and SLC7A11 protein expressions and decreased ACSL4 protein expression in the right SNc ( P<0.05). Compared with the normal control group, the PD model group, α7nAChR empty vector group and α7nAChR overexpression group had significantly increased p-KRAS, p-CAMKII, and p-ERK protein expressions in the right SNc ( P<0.05); compared with the PD model group, the α7nAChR overexpression group had significantly decreased p-KRAS, p-CAMKII, and p-ERK protein expressions in the right SNc ( P<0.05). Conclusion:The α7nAChR may exert neuroprotective effect on PD rat models by regulating the CAMKII/ERK pathway and ferroptosis-related proteins.
