40 Hz flicker light stimulation suppresses STING signaling to improve cognitive dysfunction in mice with Parkinson disease

doi:10.12122/j.issn.1673-4254.2026.10.04

Abstract

Abstract:

Objective To explore the effects of 40 Hz flicker light stimulation on cognitive dysfunction in mice with subacute Parkinson disease (PD) induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and the underlying mechanisms. Methods Forty 8-week-old male C57BL/6 mice were randomly allocated to a control group and 4 MPTP-induced PD model groups receiving blank treatment, 40 Hz flicker light stimulation, or stereotactic intraventricular injection of a control AAV (sh-NC) or an AVV carrying sh-STING. After the treatments, the mice were examined for changes in motor functions and cognitive behaviors. Immunofluorescence staining, Nissl staining, ELISA, Western blotting and RT-qPCR were used to detect hippocampal co-localization of S100A10 and C3 with GFAP, Nissl neuron count, serum interleukins, and nigral and hippocampal expressions of α-syn, TH, synaptic, astrocytic, inflammatory, SOCS3, JAK2-STAT3, and the STING pathway at the mRNA and protein levels. Results The PD mouse models exhibited impaired motor and cognitive functions with lowered TH and elevated α‑syn expressions. 40 Hz light flicker stimulation improved cognitive function of the PD mice, significantly increased the number of hippocampal neurons and S100A10 expression, and reduced the expressions of p-STING/STING, C3, GFAP, IL-6, and TNF‑α. Compared with the PD mice with sh-NC injection, the mice receiving sh-STING AVV injection showed significantly improved cognitive function with lowered hippocampal expression level of C3 and increased expression of S100A10 without significant changes in the expression levels of SOCS3 and JAK2-STAT3. Conclusion 40 Hz flicker light stimulation mitigates impairment of cognitive function in mice with MPTP-induced PD by inhibiting STING overactivation to promote A2 astrocyte polarization and enhance hippocampal synaptic plasticity.

Key words: 40 Hz light flicker stimulation, Parkinson disease, cognitive dysfunction, astrocyte polarization, STING signaling

Qianqian REN, Baowen ZHANG, Xingran LIU, Weili DING, Dandan CHEN, Xianjuan KOU. 40 Hz flicker light stimulation suppresses STING signaling to improve cognitive dysfunction in mice with Parkinson disease[J]. Journal of Southern Medical University, 2026, 46(10): 2325-2337.

Figures/Tables 10

Tab.1 Primer sequence for RT-qPCR

Gene	Forward primer (5'-3')	Reverse primer (5'-3')
BDNF	TCATACTTCGGTTGCATGAAGG	AGACCTCTCGAACCTGCCC
SYN	AGCTCAACAAATCCCAGTCTCT	CGGATGGTCTCAGCTTTCAC
PSD93	ATCATTCCTTACCTCGGCTAACT	TCAGAGGAGAGATGTGAGACTG
PSD95	TGAGATCAGTCATAGCAGCTACT	CTTCCTCCCCTAGCAGGTCC
C1q	TGGAGACCTCTCAGGGATGG	CTTTCACGCCCTTCAGTCCT
Arg-1	CTCCAAGCCAAAGTCCTTAGAG	AGGAGCTGTCATTAGGGACATC
C3	TAGAGGCCCATGATGCTCAG	AAGTTTGCCACCACTGTCAC
S100A10	TGGAAACCATGATGCTTACGTT	GAAGCCCACTTTGCCATCTC
IL-6	TAGTCCTTCCTACCCCAATTTCC	TTGGTCCTTAGCCACTCCTTC
TNF-ɑ	GACGTGGAACTGGCAGAAGAG	TTGGTGGTTTGTGAGTGTGAG
GAPDH	GGTTGTCTCCTGCGACTTCA	TGGTCCAGGGTTTCTTACTCC

Fig.1 Modeling of Parkinson disease (PD) mice and motor function test results. A: Dark box residence time in the black-and-white box test. B: Duration time in the rotating rod test. C: Duration time in the hanging test. D: Pathway map and heat map of open field test. E: Total distance and movement speed in the open field test. F: Western blotting detection results. G: Expression levels of α-syn and TH proteins. Data are presented as Mean±SD and analyzed using one-way ANOVA. #P<0.05, ##P<0.01, ####P<0.0001 vs Control. *P<0.05, **P<0.01 vs PD.

Fig.2 Cognitive function test results in each group. A: Water maze test trajectory. B: Target quadrant activity distance within the water maze. C: Number of target platform crossing within the water maze. D: Y maze test trajectory and heat map. E: Y maze spontaneous response alternation rate. F: Novel object recognition index. Data are presented as Mean±SD. #P<0.05,##P<0.01,###P<0.001 vs Control. *P<0.05 vs PD.

Fig.3 Detection results of hippocampal neurons and synapses in each group. A: Nissl staining of the hippocampus in each group (Original magnification: × 50). B: Nissl neuronal count statistics in the hippocampus in each group. C: Western blotting detection results. D: Analysis of Western blotting detection results. E: Analysis of RT-qPCR detection results. Data are presented as Mean±SD and analyzed using one-way ANOVA. #P<0.05,##P<0.01, ###P<0.001,####P<0.0001 vs Control. *P<0.05, **P<0.01, ***P<0.001, ****P<0.0001 vs PD.

Fig.4 Detection results of SOCS3 and the JAK2-STAT3-STING pathway in mouse hippocampus in each group. A: Western blotting detection results. B: Analysis of the results of Western blotting. Data are presented as Mean±SD and analyzed using one-way ANOVA. #P<0.05,##P<0.01, ###P<0.001,####P<0.0001 vs Control. *P<0.05, **P<0.01, ***P<0.001, ****P<0.0001 vs PD.

Fig.5 Detection results of hippocampal astrocyte polarization phenotypes in the mice in each group. A: Immunofluorescence staining of detecting hippocampal GFAP (green) and C3 (yellow) in each group (×100; arrows indicate co-staining regions of GFAP and C3). B: Quantitative analysis of immunofluorescence staining results. C: Immunofluorescence staining for detecting hippocampal GFAP (green) and S100A10 (red) in each group (×100; arrows indicate co-staining regions of GFAP and S100A10). D: Quantitative analysis of immunofluorescence staining results. E: Western blotting detection results. F: Quantitative analysis of Western blotting results. G: RT-qPCR detection analysis. Data are presented as Mean±SD and analyzed using one-way ANOVA. ##P<0.01, ###P<0.001,####P<0.0001 vs Control. *P<0.05, **P<0.01, ***P<0.001 vs PD.

Fig.6 Detection results of hippocampal neuroinflammation and systemic inflammation in each group. A: Analysis of RT-qPCR detection results. B: Serum ELISA detection results. C: Western blotting detection results. D: Quantitative analysis of Western blotting detection results. Data are presented as Mean±SD and analyzed using one-way ANOVA. ##P<0.01, ###P<0.001, ####P<0.0001 vs Control. *P<0.05, **P<0.01, ***P<0.001, ****P<0.0001 vs PD.

Fig.7 Effect of STING knockdown on cognitive function of PD mice. A: Western blotting detection results. B: Quantitative analysis of Western blotting results. C: Water maze test trajectory. D: Target quadrant activity path within the water maze. E: Number of target platform crossings within the water maze. F: Y maze test trajectory and heat map. G: Y maze spontaneous response alternation rate. Data are presented as Mean±SD and analyzed using one-way ANOVA. *P<0.05, **P<0.01, ***P<0.001 vs PD+sh-NC.

Fig.8 Detection results of the SOCS3-JAK2-STAT3 signaling pathway in the hippocampus of PD mice with STING knockdown. A: Western blotting detection results. B: Quantitative analysis of Western blotting results.

Fig. 9 STING knockdown affects detection results of hippocampal astrocyte polarization in mice. A: Western blotting detection results. B: Quantitative analysis of Western blotting results. C: RT-qPCR for detection of C3. D: RT-qPCR for detection of S100A10. Data are presented as Mean±SD and analyzed using one-way ANOVA. *P<0.05, **P<0.01, ***P<0.001 vs sh-NC.

References 39

[1]	Wallace ER, Segerstrom SC, van Horne CG, et al. Meta-analysis of cognition in Parkinson's disease mild cognitive impairment and dementia progression[J]. Neuropsychol Rev, 2022, 32(1): 149-60. doi：10.1007/s11065-021-09502-7
[2]	Gibson LL, Weintraub D, Lemmen R, et al. Risk of dementia in Parkinson's disease: a systematic review and meta-analysis[J]. Mov Disord, 2024, 39(10): 1697-709. doi：10.1002/mds.29918
[3]	Gallagher J, Gochanour C, Caspell-Garcia C, et al. Long-Term Dementia Risk in Parkinson Disease[J]. Neurology, 2024,103(5): e209699.
[4]	Ye H, Robak LA, Yu MG, et al. Genetics and pathogenesis of Parkinson's syndrome[J]. Annu Rev Pathol, 2023, 18: 95-121. doi：10.1146/annurev-pathmechdis-031521-034145
[5]	Kouli A, Spindler LRB, Fryer TD, et al. Neuroinflammation is linked to dementia risk in Parkinson's disease[J]. Brain, 2024, 147(3): 923-35. doi：10.1093/brain/awad322
[6]	Smajić S, Prada-Medina CA, Landoulsi Z, et al. Single-cell sequencing of human midbrain reveals glial activation and a Parkinson-specific neuronal state[J]. Brain, 2022, 145(3): 964-78. doi：10.1093/brain/awab446
[7]	Jiang SY, Tian T, Yao H, et al. The cGAS-STING-YY1 axis accelerates progression of neurodegeneration in a mouse model of Parkinson's disease via LCN2-dependent astrocyte senescence[J]. Cell Death Differ, 2023, 30(10): 2280-92. doi：10.1038/s41418-023-01216-y
[8]	Chakrabarti S, Roy A, Prorok T, et al. Aspirin up-regulates suppressor of cytokine signaling 3 in glial cells via PPARα[J]. J Neurochem, 2019, 151(1): 50-63. doi：10.1111/jnc.14813
[9]	Zhang H, Meng FB, Tang JX, et al. Lactate inhibits T-cell activation in sepsis through CD40LG downregulation and SOCS3-mediated JAK1/STAT3 pathway suppression[J]. Biochim Biophys Acta BBA Mol Basis Dis, 2025, 1871(7): 167923. doi：10.1016/j.bbadis.2025.167923
[10]	Gao Y, Liu WN, Shi L, et al. Narirutin reduces microglia-mediated neuroinflammation by inhibiting the JAK2/STAT3 pathway in MPP+/MPTP-induced Parkinson's disease models[J]. Exp Neurol, 2025, 389: 115232. doi：10.1016/j.expneurol.2025.115232
[11]	Meissner WG, Remy P, Giordana C, et al. Trial of lixisenatide in early Parkinson's disease[J]. N Engl J Med, 2024, 390(13): 1176-85. doi：10.1056/nejmoa2312323
[12]	Adaikkan C, Tsai LH. Gamma entrainment: impact on neurocircuits, Glia, and therapeutic opportunities[J]. Trends Neurosci, 2020, 43(1): 24-41. doi：10.1016/j.tins.2019.11.001
[13]	Zhang QS, Heng Y, Mou Z, et al. Reassessment of subacute MPTP-treated mice as animal model of Parkinson's disease[J]. Acta Pharmacol Sin, 2017, 38(10): 1317-28. doi：10.1038/aps.2017.49
[14]	韦雅露, 张玉雪, 卿天钰, 等. rAAV-PHP.eB病毒包装条件优化及其体外感染能力的研究[J]. 基因组学与应用生物学, 2025, 44(11): 1157-70.
[15]	张蒙, 孟祎静, 聂碧徽, 等. 自噬-STING信号在跑台运动抑制细胞焦亡改善PD小鼠认知功能障碍中的机制研究[J]. 体育科学, 2024, 44(10): 58-76.
[16]	Guillemaud O, Ceyzériat K, Saint-Georges T, et al. Complex roles for reactive astrocytes in the triple transgenic mouse model of Alzheimer disease[J]. Neurobiol Aging, 2020, 90: 135-46. doi：10.1016/j.neurobiolaging.2020.02.010
[17]	Leite Silva ABR, Gonçalves de Oliveira RW, Diógenes GP, et al. Premotor, nonmotor and motor symptoms of Parkinson's Disease: a new clinical state of the art[J]. Ageing Res Rev, 2023, 84: 101834. doi：10.1016/j.arr.2022.101834
[18]	Rau A, Philipsen L, Frings L, et al. Hippocampus and basal forebrain degeneration differentially impact cognition in Lewy body spectrum disorders[J]. Brain, 2025, 148(8): 2772-84. doi：10.1093/brain/awaf070
[19]	杨佳瑶, 何玉莲, 郭延垒, 等. 党参-茯苓配伍调控ERα/PI3K/Akt信号通路改善单侧颈总动脉永久结扎痴呆大鼠的认知障碍[J]. 南方医科大学学报, 2026, 46(2): 247-58.
[20]	Huang SY, Su ZY, Han YY, et al. Cordycepin improved the cognitive function through regulating adenosine A2A receptors in MPTP induced Parkinson's disease mice model[J]. Phytomedicine, 2023, 110: 154649. doi：10.1016/j.phymed.2023.154649
[21]	Manippa V, Palmisano A, Nitsche MA, et al. Cognitive and neuropathophysiological outcomes of gamma-tACS in dementia: a systematic review[J]. Neuropsychol Rev, 2024, 34(1): 338-61. doi：10.1007/s11065-023-09589-0
[22]	Huang FK, Huang QK, Zheng LY, et al. Effect of 40 Hz light flicker on behaviors of adult C57BL/6J mice[J]. Brain Res, 2023, 1814: 148441. doi：10.1016/j.brainres.2023.148441
[23]	Rodríguez-Cruz A, Romo-Mancillas A, Mendiola-Precoma J, et al. "Effect of valerenic acid on neuroinflammation in a MPTP-induced mouse model of Parkinson's disease"[J]. IBRO Rep, 2020, 8: 28-35. doi：10.1016/j.ibror.2019.12.002
[24]	Wolf D, Ayon-Olivas M, Sendtner M. BDNF-regulated modulation of striatal circuits and implications for Parkinson's disease and dystonia[J]. Biomedicines, 2024, 12(8): 1761. doi：10.3390/biomedicines12081761
[25]	Soman SK, Swain M, Dagda RK. BDNF-TrkB signaling in mitochondria: implications for neurodegenerative diseases[J]. Mol Neurobiol, 2025, 62(2): 1756-69. doi：10.1007/s12035-024-04357-4
[26]	Park SS, Park HS, Kim CJ, et al. Combined effects of aerobic exercise and 40-Hz light flicker exposure on early cognitive impairments in Alzheimer's disease of 3×Tg mice[J]. J Appl Physiol, 2022, 132(4): 1054-68. doi：10.1152/japplphysiol.00751.2021
[27]	Lin ZL, Hou GQ, Yao YL, et al. 40-hz blue light changes hippocampal activation and functional connectivity underlying recognition memory[J]. Front Hum Neurosci, 2021, 15: 739333. doi：10.3389/fnhum.2021.739333
[28]	张宝文, 吕梦林, 陈丹丹, 等. 40 Hz光闪烁刺激调节NAD+/Sirt1/PGC-1α信号通路对帕金森病伴抑郁小鼠的影响[J]. 中国激光, 2025, 52(15): 113-25.
[29]	Zeng JL, Indajang J, Pitt D, et al. Lysosomal acidification impairment in astrocyte-mediated neuroinflammation[J]. J Neuroinflammation, 2025, 22(1): 72. doi：10.1186/s12974-025-03410-w
[30]	黄鹏伟, 陈洁, 邹金虎, 等. 槲皮素促进应激颗粒G3BP1解聚改善HIV-1 gp120诱导的星形胶质细胞神经毒性[J]. 南方医科大学学报, 2025, 45(2): 304-12.
[31]	Guo M, Guan A, Zhang MJ, et al. Exosome-mediated microglia-astrocyte interactions drive neuroinflammation in Parkinson's disease with Peli1 as a potential therapeutic target[J]. Pharmacol Res, 2025, 219: 107908. doi：10.1016/j.phrs.2025.107908
[32]	Franklin TC, Bitarafan S, King AT, et al. Sensory neurostimulation promotes stress resilience with frequency-specificity[J]. bioRxiv. 2025, 2025:664223.
[33]	Xia XY, He XM, Zhao TM, et al. Inhibiting mtDNA-STING-NLRP3/IL-1β axis-mediated neutrophil infiltration protects neurons in Alzheimer's disease[J]. Cell Prolif, 2024, 57(1): e13529. doi：10.1111/cpr.13529
[34]	Ferecskó AS, Smallwood MJ, Moore A, et al. STING-triggered CNS inflammation in human neurodegenerative diseases[J]. Biomedicines, 2023, 11(5): 1375. doi：10.3390/biomedicines11051375
[35]	Huang XL, Hu Y, Jiang W, et al. Suppression of cGAS/STING pathway-triggered necroptosis in the hippocampus relates H₂S to attenuate cognitive dysfunction of Parkinson's disease[J]. Exp Neurol, 2025, 385: 115093. doi：10.1016/j.expneurol.2024.115093
[36]	Yue RZ, Guo X, Li WQ, et al. HDAC7 knockout mitigates astrocyte reactivity and neuroinflammation via the IRF3/cGAS/STING signaling pathway[J]. Front Cell Neurosci, 2025, 19: 1683595. doi：10.3389/fncel.2025.1683595
[37]	He JQ, Qin ZJ, Cai YN, et al. USP11-PGAM5 axis promotes neurotoxic astrocyte reactivity by aggravating the mtDNA-cGAS-STING pathway after intracerebral hemorrhage[J]. Adv Sci, 2026, 13(1): e14283. doi：10.1002/advs.202514283
[38]	Zhang W, Xu MJ, Chen FY, et al. Targeting the JAK2-STAT3 pathway to inhibit cGAS-STING activation improves neuronal senescence after ischemic stroke[J]. Exp Neurol, 2023, 368: 114474. doi：10.1016/j.expneurol.2023.114474
[39]	Meng Y, Li XY, Bi YH, et al. Tregs promote astrocyte-neuron lactate shuttle via inhibiting STING pathway to improve neurological recovery after ischemic stroke[J]. CNS Neurosci Ther, 2026, 32(1): e70753. doi：10.1002/cns.70753