在多巴胺耗尽期间,M4-受体胆固醇信号在直接通路条状投射神经元中的作用
V H Avilés‐Rosas1, E A Rendón‐Ochoa2, T Hernández-Flores1
1Instituto de Fisiología Celular, División de Neurociencias, Universidad Nacional Autónoma de México, Ciudad de México, México.
Synapse (New York, N.Y.)
|March 1, 2024
概括
肌肉M4受体 (M4R) 在多巴胺缺乏的神经元中发出信号,对于帕金森症研究至关重要,涉及Cdk5通路. M4R激活改变流和蛋白质水平,Cdk5在健康和疾病状态中起着关键作用.
科学领域:
- 神经科学是一个神经科学.
- 分子药理学分子药理学
- 神经退行性疾病 神经退行性疾病
背景情况:
- 直接通路的条状投射神经元 (dSPNs) 表达多巴胺D1受体 (D1R),M1和M4肌肉受体 (M1R,M4R).
- D1R信号通过蛋白激酶A (PKA) 和DARPP-32增强神经元发射,而M1R使用Gq蛋白和蛋白激酶C.
- 在dSPN中M4R信号传递机制的理解较少,提出的途径涉及Gi/o蛋白和循环林依赖激酶5 (Cdk5).
研究的目的:
- 研究dSPN中M4R的信号机制,特别是Cdk5通路的作用.
- 为了确定M4R通过CaV1Ca2+通道的促进性调制是否在实验性帕金森症 (DA-depletion) 中持续存在.
- 阐明DA-枯竭对M4R蛋白水平和下游信号的影响.
主要方法:
- 在dSPN中进行电生理记录以测量CaV1 Ca2+电流.
- 使用roscovitine进行Cdk5的药理抑制.
- 抑制蛋白酸酶1 (PP-1),以评估其在M4R信号传递中的作用.
- 西部斑点分析以量化M4R蛋白水平.
主要成果:
- M4R激活促进dSPNs中的CaV1Ca2+通道,由Cdk5通道进行介导.
- 在DA枯竭的条件下,M4R激活降低了Ca2+当前和增加了M4R蛋白水平,与对照反应形成鲜明对比.
- 罗斯科维对Cdk5的抑制在对照和DA贫乏状态中阻断了M4R的作用,证实了Cdk5的参与.
- 在DA减弱条件下,PP-1抑制恢复了类似对照的M4R作用,表明过度的PP-1活性.
结论:
- 在dSPN中,Cdk5通路对dSPN中的CaV1Ca2+通道产生M4R促进作用.
- DA-depletion改变M4R信号,导致Ca2+电流减少和M4R蛋白水平增加,其中Cdk5和PP-1发挥关键作用.
- 这些发现为帕金森症中变化的条状神经元信号提供了洞察力,并表明了潜在的治疗点.
相关概念视频
Direct-Acting Cholinergic Agonists: Pharmacological Actions
1.3K
Direct-acting cholinergic agonists exert their pharmacological actions by mimicking the effects of acetylcholine on postsynaptic muscarinic receptors to generate parasympathetic responses. These agents elicit a range of physiological responses, including cardiovascular effects. For example, activation of muscarinic receptors induces bradycardia, decreased cardiac output, reduced peripheral resistance, and consequent hypotension. In the eye, stimulation of M3 receptors leads to smooth muscle...
1.3K
Cholinergic Receptors: Muscarinic
2.2K
The pharmacological actions of acetylcholine are elicited via its binding to two families of cholinergic receptors or cholinoceptors, namely, muscarinic and nicotinic receptors. Muscarinic receptors are G protein-coupled receptors and have five subtypes, M1–M5. All mAChR subtypes are activated by acetylcholine and blocked by the antagonist, atropine.
The subtypes M1, M3, and M5 couple with the Gq subunit and activate the phospholipase C (PLC) activity, mobilizing intracellular Ca2+....
The subtypes M1, M3, and M5 couple with the Gq subunit and activate the phospholipase C (PLC) activity, mobilizing intracellular Ca2+....
2.2K
Direct-Acting Cholinergic Agonists: Pharmacokinetics
1.1K
Direct-acting cholinergic agonists, such as synthetic choline esters and naturally occurring alkaloids, exert their effects by enhancing the actions of acetylcholine and stimulating the parasympathetic nervous system. Synthetic choline esters share structural similarities with acetylcholine. For example, they have a positively charged quaternary ammonium or onium group, contributing to their hydrophilic characteristics. As a result, they are poorly absorbed in the body through oral...
1.1K
Drugs Affecting Neurotransmitter Synthesis
1.4K
Drugs affecting neurotransmitter synthesis can impact the adrenergic neuron and the synthesis of neurotransmitters. For example, α-methyltyrosine and carbidopa target specific enzymes involved in catecholamine synthesis. α-methyltyrosine inhibits the enzyme tyrosine hydroxylase, which converts tyrosine into dopamine. By blocking this enzyme, α-methyltyrosine reduces dopamine production and other catecholamines. Carbidopa, on the other hand, inhibits the enzyme dopa decarboxylase,...
1.4K
Adrenergic Agonists: Indirect-Acting Agents
1.6K
Indirect-acting adrenergic agonists potentiate the effects of endogenous catecholamines through different mechanisms without directly binding to adrenoceptors.
One mechanism involves depleting stored catecholamines by displacing them from synaptic vesicles. These agents, known as "displacers," are transported into vesicles at the expense of noradrenaline. Examples include amphetamine and tyramine, which lack a catechol moiety, resulting in prolonged action, improved oral...
One mechanism involves depleting stored catecholamines by displacing them from synaptic vesicles. These agents, known as "displacers," are transported into vesicles at the expense of noradrenaline. Examples include amphetamine and tyramine, which lack a catechol moiety, resulting in prolonged action, improved oral...
1.6K
Direct-Acting Cholinergic Agonists: Chemistry and Structure-Activity Relationship
958
Cholinergic agonists or cholinomimetics mimic the action of acetylcholine to stimulate the parasympathetic nervous system. They are categorized into direct-acting and indirect-acting agents. The direct-acting cholinergic drugs induce the parasympathetic response by directly binding to the muscarinic or nicotine receptors. In comparison, the indirect-acting cholinergic drugs prevent acetylcholine hydrolysis, indirectly contributing to the extended parasympathetic response.
The direct-acting...
The direct-acting...
958


