Department of Anatomy, Physiology, Pharmacology; College of Medicine, University of Saskatchewan, 105 Wiggins Road, Health Sciences Bldg. Room GD30.5, Saskatoon, SK, S7N 5E5, Canada.
College of Pharmacy and Nutrition, University of Saskatchewan, 105 Wiggins Road, Health Sciences Bldg. Room 3B36, Saskatoon, SK, S7N 5E5, Canada.
Mol Brain. 2021 Jun 7;14(1):89. doi: 10.1186/s13041-021-00801-x.
The type 1 and type 2 cannabinoid receptors (CB1 and CB2 receptors) are class A G protein-coupled receptors (GPCRs) that are activated by endogenous lipids called endocannabinoids to modulate neuronal excitability and synaptic transmission in neurons throughout the central nervous system (CNS), and inflammatory processes throughout the body. CB1 receptor is one of the most abundant GPCRs in the CNS and is involved in many physiological and pathophysiological processes, including mood, appetite, and nociception. CB2 receptor is primarily found on immunomodulatory cells of both the CNS and the peripheral immune system. In this study, we isolated lipid raft and non-lipid raft fractions of plasma membrane (PM) from mouse cortical tissue by using cold non-ionic detergent and sucrose gradient centrifugation to study the localization of CB1 receptor and CB2 receptor. Lipid raft and non-lipid raft fractions were confirmed by flotillin-1, caveolin-1 and transferrin receptor as their protein biomarkers. Both CB1 receptor and CB2 receptor were found in non-raft compartments that is inconsistent with previous findings in cultured cell lines. This study demonstrates compartmentalization of both CB1 receptor and CB2 receptor in cortical tissue and warrants further investigation of CB1 receptor and CB2 receptor compartmental distribution in various brain regions and cell types.
1 型和 2 型大麻素受体（CB1 和 CB2 受体）是 A 类 G 蛋白偶联受体（GPCR），它们被称为内源性大麻素的内源性脂质激活，从而调节整个中枢神经系统（CNS）中神经元的兴奋性和突触传递，以及全身的炎症过程。CB1 受体是 CNS 中最丰富的 GPCR 之一，参与许多生理和病理生理过程，包括情绪、食欲和痛觉。CB2 受体主要存在于 CNS 和外周免疫系统的免疫调节细胞上。在这项研究中，我们使用冷非离子去污剂和蔗糖梯度离心从鼠皮质组织中分离出质膜（PM）的脂筏和非脂筏部分，以研究 CB1 受体和 CB2 受体的定位。脂筏和非脂筏部分通过 flotillin-1、caveolin-1 和转铁蛋白受体作为其蛋白生物标志物得到证实。CB1 受体和 CB2 受体都存在于非筏状隔室中，这与先前在培养细胞系中的发现不一致。这项研究表明 CB1 受体和 CB2 受体在皮质组织中的隔室化，并需要进一步研究 CB1 受体和 CB2 受体在不同脑区和细胞类型中的隔室分布。
