Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Sector-67, S.A.S. Nagar, Punjab 160 062, India.
Rev Neurosci. 2011;22(3):355-63. doi: 10.1515/RNS.2011.028. Epub 2011 May 13.
Albumin is the most abundant plasma protein synthesised mainly in the liver. It is also a major component of extracellular fluids including cerebrospinal fluid, interstitial fluid and lymph. Albumin has several biochemical properties including regulation of colloid osmotic pressure of plasma, transportation of hormones, fatty acids, drugs and metabolites across plasma, regulation of microvascular permeability, antioxidant activity, anti-thrombotic activity and anti-inflammatory activity. This multifunctional protein has been implicated in many neurological diseases owing to its ability to regulate hemodynamic properties of the brain circulation as well as the direct neuroprotective actions on neuronal and glial cells. In this review, we summarise various neuroprotective actions of the albumin in the brain. In experimental ischemic stroke, exogenous human serum albumin administration has been found to be neuroprotective via reducing brain swelling, prevention of post-ischemic thrombosis, anti-oxidant activity, hemodilution and increasing the perfusion to the ischemic tissue. Also, human serum albumin administration is currently under clinical trials for treatment of cerebral ischemia. In the experimental models of Alzheimer's disease, albumin has been implicated in neuroprotection by inhibiting polymerisation and enhancing the clearance of amyloid β. The direct neuroprotective actions on neuronal and glial cells are mediated via endogenously produced albumin or cellular uptake of blood derived albumin. These neuroprotective effects of albumin are partly attributed to anti-oxidant property and modulation of intracellular signalling of neuronal or glial cells. The recent finding of de novo synthesis of albumin in microglial cells directs us to explore newer roles of this endogenously produced multifunctional protein in normal as well as pathological conditions of the brain.
白蛋白是最丰富的血浆蛋白质，主要在肝脏中合成。它也是细胞外液的主要成分，包括脑脊液、间质液和淋巴。白蛋白具有多种生化特性，包括调节血浆胶体渗透压、激素、脂肪酸、药物和代谢物在血浆中的转运、调节微血管通透性、抗氧化活性、抗血栓形成活性和抗炎活性。由于其调节脑循环血液动力学特性以及对神经元和神经胶质细胞的直接神经保护作用，这种多功能蛋白与许多神经疾病有关。在本综述中，我们总结了白蛋白在大脑中的各种神经保护作用。在实验性缺血性中风中，外源性人血清白蛋白的给药已被发现具有神经保护作用，可减轻脑水肿、预防缺血后血栓形成、抗氧化活性、血液稀释和增加缺血组织的灌注。此外，人血清白蛋白的给药目前正在临床试验中用于治疗脑缺血。在阿尔茨海默病的实验模型中，白蛋白通过抑制淀粉样β的聚合和增强其清除而被认为具有神经保护作用。对神经元和神经胶质细胞的直接神经保护作用是通过内源性产生的白蛋白或血液来源的白蛋白的细胞摄取介导的。白蛋白的这些神经保护作用部分归因于抗氧化特性和对神经元或神经胶质细胞的细胞内信号转导的调节。最近在小胶质细胞中发现白蛋白的从头合成，促使我们探索这种内源性产生的多功能蛋白在大脑正常和病理状态下的新作用。
