Husemann Jens, Loike John D, Anankov Roman, Febbraio Maria, Silverstein Samuel C
Department of Physiology and Cellular Biophysics, Columbia University, New York, New York.
Department of Medicine, Division of Hematology and Medical Oncology, Center of Vascular Biology, Weill Medical College of Cornell University, New York, New York.
Glia. 2002 Nov;40(2):195-205. doi: 10.1002/glia.10148.
Scavenger receptor class A (SR-A, CD204), scavenger receptor-BI (SR-BI), and CD36 are cell surface proteins that mediate cell adhesion to, and endocytosis of, various native and pathologically modified substances, and participate in intracellular signaling, lipid metabolism, and host defense against bacterial pathogens. Microglia, Mato cells, astrocytes, cerebral microvascular endothelial cells, cerebral arterial smooth muscle cells, and retinal pigment epithelial cells express one or more of these SR. Expression of SR-A and SR-BI by microglia is developmentally regulated. Neonatal microglia express SR-A and SR-BI, while microglia in normal mouse and human adult brain express neither. Astrocytes in adult brain express SR-BI. In Alzheimer's disease, microglial expression of SR-A is increased. Such findings, and evidence that SR-A and SR-BI mediate adhesion and endocytosis of fibrillar beta-amyloid by microglia and astrocytes, respectively, and that SR-A, SR-BI, and CD36 participate in secretion of reactive oxygen species by microglia, suggest roles for these receptors in homeostasis and neuropathology.
A类清道夫受体（SR-A，CD204）、清道夫受体BI（SR-BI）和CD36是细胞表面蛋白，它们介导细胞对各种天然和病理修饰物质的黏附及内吞作用，并参与细胞内信号传导、脂质代谢以及宿主对细菌病原体的防御。小胶质细胞、Mato细胞、星形胶质细胞、脑微血管内皮细胞、脑动脉平滑肌细胞和视网膜色素上皮细胞表达这些清道夫受体中的一种或多种。小胶质细胞中SR-A和SR-BI的表达受发育调控。新生小胶质细胞表达SR-A和SR-BI，而正常成年小鼠和人类大脑中的小胶质细胞均不表达。成年大脑中的星形胶质细胞表达SR-BI。在阿尔茨海默病中，小胶质细胞SR-A的表达增加。这些发现，以及SR-A和SR-BI分别介导小胶质细胞和星形胶质细胞对纤维状β淀粉样蛋白的黏附及内吞作用，以及SR-A、SR-BI和CD36参与小胶质细胞活性氧分泌的证据，提示这些受体在体内稳态和神经病理学中发挥作用。
