Role of neuroinflammation in neurodegenerative diseases (Review)

Abstract

Neurodegeneration is a phenomenon that occurs in the central nervous system through the hallmarks associating the loss of neuronal structure and function. Neurodegeneration is observed after viral insult and mostly in various so-called 'neurodegenerative diseases', generally observed in the elderly, such as Alzheimer's disease, multiple sclerosis, Parkinson's disease and amyotrophic lateral sclerosis that negatively affect mental and physical functioning. Causative agents of neurodegeneration have yet to be identified. However, recent data have identified the inflammatory process as being closely linked with multiple neurodegenerative pathways, which are associated with depression, a consequence of neurodegenerative disease. Accordingly, pro-inflammatory cytokines are important in the pathophysiology of depression and dementia. These data suggest that the role of neuroinflammation in neurodegeneration must be fully elucidated, since pro-inflammatory agents, which are the causative effects of neuroinflammation, occur widely, particularly in the elderly in whom inflammatory mechanisms are linked to the pathogenesis of functional and mental impairments. In this review, we investigated the role played by the inflammatory process in neurodegenerative diseases.

Thymoquinone increases the expression of neuroprotective proteins while decreasing the expression of pro-inflammatory cytokines and the gene expression NFκB pathway signaling targets in LPS/IFNγ -activated BV-2 microglia cells

“…Neuroinflammation has been increasingly implicated in the onset and progression of multiple neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD) and Multiple Sclerosis (MS), despite their differing pathologies (Liu and Hong, 2003; Block and Hong, 2005; Gao and Hong, 2008; Chen et al, 2016; Kempuraj et al, 2016). Neuroinflammation is an innate, and initially, protective response mechanism in the brain, facilitated mostly by microglia and astrocytes producing a broad spectrum of inflammatory mediators (Azizi et al, 2015; Von Bernhardi et al, 2015).…”

Role of neuroinflammation in ischemic stroke

“…Ischemic stroke mediated brain injury results in necrosis and apoptosis. [69][70][71] The damaged cells and debris induces neuroinflammation in areas in and around the ischemic injury in the brain. [72] Ischemia-induced cell debris and increased ROS lead to neuroinflammation by activating resident microglia and astrocytes as well as attracting infiltrating leukocytes from circulating blood.…”

Insights into the Role of Neuroinflammation in the Pathogenesis of Multiple Sclerosis

“…For some people, MS is characterised by periods of relapse and remission while, for others, the disease exhibits a progressive pattern. Due to the spectrum of symptoms and clinical manifestations, it is not surprising that the life of MS patients may become unpredictable [4,8,[11][12][13].…”

“…The idea is that neuroinflammation induced by viral infection promotes the recruitment of inflammatory cells, mainly CD2+ cells, through the blood brain barrier (BBB). The viral theory relates to the possibility that certain sub-classes of viruses may exhibit antigenic mimicry to the myelin sheet and certain parts of the CNS, hence triggering an autoimmune response versus the latter [13,30,31].…”

“…The central mechanisms of MS pathogenesis encompass a series of features such as changes in the permeability of the BBB, genetic modifications that render the individual susceptible to immune attacks, myelin sheath destruction, axonal damage and CNS scarring [9,13].…”