School of Biology, College of Science, University of Tehran, Tehran, Iran.
Institute of Biochemistry and Biophysics (IBB), University of Tehran, Tehran, Iran.
Rev Neurosci. 2022 Apr 2;33(7):803-817. doi: 10.1515/revneuro-2021-0165. Print 2022 Oct 26.
Serum albumin (SA) exists in relatively high concentrations, in close contact with most cells. However, in the adult brain, except for cerebrospinal fluid (CSF), SA concentration is relatively low. It is mainly produced in the liver to serve as the main protein of the blood plasma. In the plasma, it functions as a carrier, chaperon, antioxidant, source of amino acids, osmoregulator, etc. As a carrier, it facilitates the stable presence and transport of the hydrophobic and hydrophilic molecules, including free fatty acids, steroid hormones, medicines, and metal ions. As a chaperon, SA binds to and protects other proteins. As an antioxidant, thanks to a free sulfhydryl group (-SH), albumin is responsible for most antioxidant properties of plasma. These functions qualify SA as a major player in, and a mirror of, overall health status, aging, and neurodegeneration. The low concentration of SA is associated with cognitive deterioration in the elderly and negative prognosis in multiple sclerosis (MS) and amyotrophic lateral sclerosis (ALS). SA has been shown to be structurally modified in neurological conditions such as Alzheimer's disease (AD). During blood-brain barrier damage albumin enters the brain tissue and could trigger epilepsy and neurodegeneration. SA is able to bind to the precursor agent of the AD, amyloid-beta (Aβ), preventing its toxic effects in the periphery, and is being tested for treating this disease. SA therapy may also be effective in brain rejuvenation. In the current review, we will bring forward the prominent properties and roles of SA in neurodegeneration.
血清白蛋白（SA）在体内的浓度相对较高，与大多数细胞密切接触。然而，在成年人的大脑中，除了脑脊液（CSF）之外，SA 的浓度相对较低。SA 主要在肝脏中产生，作为血浆的主要蛋白质。在血浆中，它作为载体、伴侣、抗氧化剂、氨基酸来源、渗透压调节剂等发挥作用。作为载体，它促进了包括游离脂肪酸、甾体激素、药物和金属离子在内的疏水分子和亲水分子的稳定存在和运输。作为伴侣，SA 结合并保护其他蛋白质。作为抗氧化剂，由于含有游离巯基（-SH），白蛋白负责血浆中大部分抗氧化特性。这些功能使 SA 成为整体健康状况、衰老和神经退行性变的主要参与者和反映者。SA 浓度低与老年人认知能力下降以及多发性硬化症（MS）和肌萎缩侧索硬化症（ALS）的预后不良有关。研究表明，SA 在阿尔茨海默病（AD）等神经疾病中结构发生了改变。在血脑屏障损伤期间，白蛋白进入脑组织，可能引发癫痫和神经退行性变。SA 能够结合 AD 的前体物质淀粉样蛋白-β（Aβ），从而在周围组织中阻止其产生毒性作用，目前正在对其进行治疗这种疾病的测试。SA 治疗也可能对大脑年轻化有效。在本综述中，我们将提出 SA 在神经退行性变中的突出特性和作用。
