HU Yunyun,LYU Yujie,MENG Zhipeng,et al.Hei Xiaoyaosan Affects Synaptic Plasticity of Hippocampal Neurons in APP/PS1 Double Transgenic Mice of AD via cAMP/PKA/NMDAR Signaling Pathway[J].Chinese Journal of Experimental Traditional Medical Formulae,2024,30(17):27-34.
HU Yunyun,LYU Yujie,MENG Zhipeng,et al.Hei Xiaoyaosan Affects Synaptic Plasticity of Hippocampal Neurons in APP/PS1 Double Transgenic Mice of AD via cAMP/PKA/NMDAR Signaling Pathway[J].Chinese Journal of Experimental Traditional Medical Formulae,2024,30(17):27-34. DOI: 10.13422/j.cnki.syfjx.20240744.
Hei Xiaoyaosan Affects Synaptic Plasticity of Hippocampal Neurons in APP/PS1 Double Transgenic Mice of AD via cAMP/PKA/NMDAR Signaling Pathway
To explore the effect and mechanism of Hei Xiaoyaosan in modulating the synaptic plasticity in APP/PS1 mice by regulating the cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA)/
N
-methyl-
D
-aspartate receptor (NMDAR) signaling pathway.
Method
2
Twelve 4-month-old male C57BL/6J mice were selected as the blank control group, and 60 4-month-old male APP/PS1 double transgenic mice were randomized into model, KW-6002 (adenosine receptor antagonist, 3 mg·kg
-1
), and high-, medium-, and low-dose (22.10, 11.05, 5.53 g·kg
-1
, respectively) Hei Xiaoyaosan groups, with 12 mice in each group. Mice were administrated with corresponding drugs for 90 days. Transmission electron microscopy was employed to observe the synaptic ultrastructure of hippocampal neurons, and Golgi staining was used to observe the dendritic spine density of neurons in hippocampal CA1 region. Western blot was employed to measure the protein levels of cAMP, PKA,
N
-methyl-
D
-aspartate receptors 1, 2A, and 2B (NR1, NR2A, and NR2B, respectively), postsynaptic density protein 95 (PSD95), and synapsin 1 (SYN1). Real-time fluorescence quantitative polymerase chain reaction(Real-time PCR) was performed to determine the mRNA levels of cAMP, PKA, and NR1. Enzyme-linked immunosorbent assay was employed to determine the content of interleukin-12 (IL-12) and interleukin-4 (IL-4) in the hippocampus.
Result
2
Compared with the blank group, the model group showed blurred boundaries between presynaptic membrane and postsynaptic membrane in hippocampal CA1 region, reduced and scattered synaptic vesicles, and decreased density of postsynaptic membrane, and irregular, disarranged, and loosened dendritic spines of neurons in hippocampal CA1 region (
P
<
0.01). In addition, the model group presented down-regulated protein levels of cAMP, PKA, NR1, NR2A, NR2B, PSD95, and SYN1 and mRNA levels of cAMP, PKA, and NR1, elevated IL-12 level, and lowered IL-4 level in the hippocampus (
P
<
0.01). Compared with the model group, the drug intervention groups showed clear and intact boundaries between presynaptic membrane and post
synaptic membrane in hippocampal CA1 region, increased synaptic vesicles with dense arrangement, increased density of postsynaptic membrane, and improved morphology, arrangement, and density of neuronal dendritic spines (
P
<
0.05,
P
<
0.01). In addition, the drug interventions up-regulated the protein levels of cAMP, PKA, NR1, NR2A, NR2B, PSD95, and SYN1 (
P
<
0.05,
P
<
0.01) and mRNA levels of cAMP, PKA, and NR1 (
P
<
0.01), lowered the IL-12 level (
P
<
0.01), and elevated the IL-4 level (
P
<
0.01) in the hippocampus.
Conclusion
2
Hei Xiaoyaosan can improve the structure and morphology of hippocampal neurons in APP/PS1 mice by activating the cAMP/PKA/NMDAR signaling pathway and repairing synaptic plasticity.
LEONARD A S,HELL J W.Cyclic AMP-dependent protein kinase and protein kinase C phosphorylate N-methyl-D-aspartate receptors at different sites[J].J Biol Chem,1997,272(18):12107-12115.
OLIVEROS A,YOO K H,RASHID M A,et al.Adenosine A(2A) receptor blockade prevents cisplatin-induced impairments in neurogenesis and cognitive function[J].Proc Natl Acad Sci USA,2022,119(28):e2206415119.
TWAROWSKI B,HERBET M.Inflammatory processes in Alzheimer's disease-pathomechanism, diagnosis and treatment:A review[J].Int J Mol Sci,2023,24(7):6518.
ZHENG K,HU F,ZHOU Y,et al.miR-135a-5p mediates memory and synaptic impairments via the Rock2/Adducin1 signaling pathway in a mouse model of Alzheimer's disease[J].Nat Commun, 2021, 12(1): 1903.
MA S,ZUO Y.Synaptic modifications in learning and memory-A dendritic spine story[J].Semin Cell Dev Biol,2022,125:84-90.
MCQUATE A,BARRIA A.Rapid exchange of synaptic and extrasynaptic NMDA receptors in hippocampal CA1 neurons[J].J Neurophysiol,2020,123(3):1004-1014.
KÖHR G.NMDA receptor function:Subunit composition versus spatial distribution[J].Cell Tissue Res,2006,326(2):439-446.
YU S P,JIANG M Q,SHIM S S,et al.Extrasynaptic NMDA receptors in acute and chronic excitotoxicity: Implications for preventive treatments of ischemic stroke and late-onset Alzheimer's disease[J].Mol Neurodegener,2023,18(1):43.
MA W,LU K,LIANG H M,et al.Synapsin 1 ameliorates cognitive impairment and neuroinflammation in rats with alzheimer's disease:An experimental and bioinformatics study[J].Curr Alzheimer Res,2023,20(9):648-659.
COLEY A A,GAO W J.PSD95:A synaptic protein implicated in schizophrenia or autism?[J].Prog Neuropsychopharmacol Biol Psychiatry,2018,82:187-194.
WANG J,HE X,GUO F,et al.Multiple kinases involved in the nicotinic modulation of gamma oscillations in the rat hippocampal CA3 area[J].Front Cell Neurosci,2017,11:57.
WESTPHAL R S,TAVALIN S J,LIN J W,et al.Regulation of NMDA receptors by an associated phosphatase-kinase signaling complex[J].Science,1999,285(5424):93-96.
ARNSTEN A,DATTA D,WANG M.The genie in the bottle-magnified calcium signaling in dorsolateral prefrontal cortex[J].Mol Psychiatry,2021,26(8):3684-3700.