Kempuraj D, Thangavel R, Natteru P A, Selvakumar G P, Saeed D, Zahoor H, Zaheer S, Iyer S S, Zaheer A
Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, Columbia, MO, USA; Harry S. Truman Memorial Veterans Hospital, Columbia, MO, USA.
Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of Missouri, Columbia, MO, USA.
J Neurol Neurosurg Spine. 2016;1(1). Epub 2016 Nov 18.
Neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), and Multiple Sclerosis (MS) are characterized by neuronal degeneration and neuronal death in specific regions of the central nervous system (CNS). In AD, neurons of the hippocampus and entorhinal cortex are the first to degenerate, whereas in PD, dopaminergic neurons in the substantia nigra degenerate. MS patients show destruction of the myelin sheath. Once the CNS neurons are damaged, they are unable to regenerate unlike any other tissue in the body. Neurodegeneration is mediated by inflammatory and neurotoxic mediators such as interleukin-1beta (IL-1β), IL-6, IL-8, IL-33, tumor necrosis factor-alpha (TNF-α), chemokine (C-C motif) ligand 2 (CCL2), CCL5, matrix metalloproteinase (MMPs), granulocyte macrophage colony-stimulating factor (GM-CSF), glia maturation factor (GMF), substance P, reactive oxygen species (ROS), reactive nitrogen species (RNS), mast cells-mediated histamine and proteases, protease activated receptor-2 (PAR-2), CD40, CD40L, CD88, intracellular Ca elevation, and activation of mitogen-activated protein kinases (MAPKs) and nuclear factor kappa-B (NF-kB). Activated microglia, astrocytes, neurons, T-cells and mast cells release these inflammatory mediators and mediate neuroinflammation and neurodegeneration in a vicious manner. Further, immune and inflammatory cells and inflammatory mediators from the periphery cross the defective blood-brain-barrier (BBB) and augment neuroinflammation. Though inflammation is crucial in the onset and the progression of neurodegenerative diseases, anti-inflammatory drugs do not provide significant therapeutic effects in these patients till date, as the disease pathogenesis is not yet clearly understood. In this review, we discuss the possible factors involved in neuroinflammation-mediated neurodegeneration.
诸如阿尔茨海默病(AD)、帕金森病(PD)和多发性硬化症(MS)等神经退行性疾病的特征是中枢神经系统(CNS)特定区域的神经元变性和神经元死亡。在AD中,海马体和内嗅皮质的神经元最先发生变性,而在PD中,黑质中的多巴胺能神经元发生变性。MS患者表现出髓鞘的破坏。一旦CNS神经元受损,它们就无法像身体中的其他组织那样再生。神经变性由炎症和神经毒性介质介导,如白细胞介素-1β(IL-1β)、IL-6、IL-8、IL-33、肿瘤坏死因子-α(TNF-α)、趋化因子(C-C基序)配体2(CCL2)、CCL5、基质金属蛋白酶(MMPs)、粒细胞巨噬细胞集落刺激因子(GM-CSF)、胶质细胞成熟因子(GMF)、P物质、活性氧(ROS)、活性氮(RNS)、肥大细胞介导的组胺和蛋白酶、蛋白酶激活受体-2(PAR-2)、CD40、CD40L、CD88、细胞内钙升高以及丝裂原活化蛋白激酶(MAPKs)和核因子κB(NF-κB)的激活。活化的小胶质细胞、星形胶质细胞、神经元、T细胞和肥大细胞释放这些炎症介质,并以恶性方式介导神经炎症和神经变性。此外,来自外周的免疫细胞、炎症细胞和炎症介质穿过有缺陷的血脑屏障(BBB),加剧神经炎症。尽管炎症在神经退行性疾病的发病和进展中至关重要,但迄今为止,抗炎药物在这些患者中并未提供显著疗效,因为疾病发病机制尚未完全明确。在本综述中,我们讨论了神经炎症介导的神经变性中可能涉及的因素。