背景:我们最近报道了多巴胺(DA)类似物CA140在注射脂多糖的野生型(WT)小鼠和3个月大的5xFAD小鼠中调节神经炎症反应,阿尔茨海默病(AD)模型。然而,CA140对Aβ/tau病理和突触/认知功能的影响及其分子作用机制尚不清楚。
方法:为了研究CA140对认知和突触功能以及AD病理的影响,3月龄WT小鼠或8月龄(老年)5xFAD小鼠注射媒介物(10%DMSO)或CA140(30mg/kg,i.p.)每天10、14或17天。行为测试,ELISA,电生理学,RNA测序,实时PCR,高尔基染色,免疫荧光染色,进行了西方印迹。
结果:在老年5xFAD小鼠中,AD病理模型,CA140治疗显著减少Aβ/tau纤维性颤动,Aβ斑块数,tau过度磷酸化,和神经炎症通过抑制NLRP3激活。此外,CA140治疗下调了cxcl10的表达,cxcl10是AD相关反应性星形胶质细胞(RAs)的标志物,和c1qa,在5xFAD小鼠中RAs与疾病相关小胶质细胞(DAMs)相互作用的标志物。CA140治疗还抑制了s100β和cxcl10的mRNA水平,这是AD相关RAs的标志物,在来自5xFAD小鼠的原代星形胶质细胞中。在来自5xFAD小鼠的原代小胶质细胞中,CA140治疗增加了稳态小胶质细胞标志物(cx3cr1和p2ry12)的mRNA水平,并降低了增殖区相关小胶质细胞标志物(gpnmb)和脂质液滴积聚小胶质细胞标志物(cln3)的mRNA水平。重要的是,CA140治疗挽救了东莨菪碱(SCO)介导的长期记忆缺陷,树突脊数,和LTP减值。在5xFAD小鼠中,CA140治疗对认知/突触功能和AD病理的影响受多巴胺D1受体(DRD1)/Elk1信号调节.在原代海马神经元和WT小鼠中,CA140治疗通过对DRD1/CaMKIIα和/或ERK信号传导的影响促进长期记忆和树突棘形成。
结论:我们的结果表明,CA140通过调节原代海马神经元的DRD1信号,改善神经元/突触/认知功能,改善Aβ/tau病理和神经炎症,原代星形胶质细胞/小胶质细胞,WT小鼠,和5xFAD小鼠。
BACKGROUND: We recently reported that the dopamine (DA) analogue CA140 modulates neuroinflammatory responses in lipopolysaccharide-injected wild-type (WT) mice and in 3-month-old 5xFAD mice, a model of Alzheimer\'s disease (AD). However, the effects of CA140 on Aβ/tau pathology and synaptic/cognitive function and its molecular mechanisms of action are unknown.
METHODS: To investigate the effects of CA140 on cognitive and synaptic function and AD pathology, 3-month-old WT mice or 8-month-old (aged) 5xFAD mice were injected with vehicle (10% DMSO) or CA140 (30 mg/kg, i.p.) daily for 10, 14, or 17 days. Behavioral tests, ELISA, electrophysiology, RNA sequencing, real-time PCR, Golgi staining, immunofluorescence staining, and western blotting were conducted.
RESULTS: In aged 5xFAD mice, a model of AD pathology, CA140 treatment significantly reduced Aβ/tau fibrillation, Aβ plaque number, tau hyperphosphorylation, and neuroinflammation by inhibiting NLRP3 activation. In addition, CA140 treatment downregulated the expression of cxcl10, a marker of AD-associated reactive astrocytes (RAs), and c1qa, a marker of the interaction of RAs with disease-associated microglia (DAMs) in 5xFAD mice. CA140 treatment also suppressed the mRNA levels of s100β and cxcl10, markers of AD-associated RAs, in primary astrocytes from 5xFAD mice. In primary microglial cells from 5xFAD mice, CA140 treatment increased the mRNA levels of markers of homeostatic microglia (cx3cr1 and p2ry12) and decreased the mRNA levels of a marker of proliferative region-associated microglia (gpnmb) and a marker of lipid-droplet-accumulating microglia (cln3). Importantly, CA140 treatment rescued scopolamine (SCO)-mediated deficits in long-term memory, dendritic spine number, and LTP impairment. In aged 5xFAD mice, these effects of CA140 treatment on cognitive/synaptic function and AD pathology were regulated by dopamine D1 receptor (DRD1)/Elk1 signaling. In primary hippocampal neurons and WT mice, CA140 treatment promoted long-term memory and dendritic spine formation via effects on DRD1/CaMKIIα and/or ERK signaling.
CONCLUSIONS: Our results indicate that CA140 improves neuronal/synaptic/cognitive function and ameliorates Aβ/tau pathology and neuroinflammation by modulating DRD1 signaling in primary hippocampal neurons, primary astrocytes/microglia, WT mice, and aged 5xFAD mice.