Neuroinflammation and Alzheimer’s Disease Pathophysiology

Posted: June 6th, 2021

Neuroinflammation and Alzheimer’s Disease Pathophysiology: Explore the role of neuroinflammation in the pathophysiology of Alzheimer’s disease. Investigate the activation of microglia and the release of pro-inflammatory cytokines in the brain, and their contributions to the development and progression of Alzheimer’s. Examine potential therapeutic strategies aimed at modulating neuroinflammatory responses to delay or mitigate the disease.
Neuroinflammation and Alzheimer’s Disease Pathophysiology

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder that affects millions of people worldwide. It is characterized by the accumulation of amyloid-beta (Aβ) plaques and neurofibrillary tangles (NFTs) in the brain, leading to synaptic dysfunction, neuronal loss, and cognitive impairment. However, the exact mechanisms underlying AD pathogenesis remain unclear.

One of the emerging factors that may contribute to AD development and progression is neuroinflammation, which refers to the activation of the innate immune system in the central nervous system (CNS). Neuroinflammation is a complex and dynamic process that involves various cellular and molecular components, such as microglia, astrocytes, cytokines, chemokines, complement system, and toll-like receptors (TLRs).

Microglia are the resident immune cells of the CNS that play a crucial role in maintaining brain homeostasis and responding to injury or infection. However, under pathological conditions, such as AD, microglia can become chronically activated and produce pro-inflammatory cytokines, such as interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6), as well as reactive oxygen species (ROS) and nitric oxide (NO). These inflammatory mediators can further enhance Aβ production and aggregation, impair synaptic function and plasticity, induce neuronal death, and exacerbate cognitive decline.

Therefore, modulating neuroinflammatory responses may represent a potential therapeutic strategy for AD. Several approaches have been proposed to target different aspects of neuroinflammation, such as inhibiting microglial activation, reducing cytokine production or signaling, enhancing anti-inflammatory pathways, or restoring the balance between pro- and anti-inflammatory factors. Some of the promising agents that have shown beneficial effects in preclinical or clinical studies include non-steroidal anti-inflammatory drugs (NSAIDs), minocycline, curcumin, resveratrol, omega-3 fatty acids, and cannabinoids.

However, there are also challenges and limitations in developing anti-inflammatory therapies for AD. For instance, neuroinflammation is not a uniform process, but rather a dynamic and heterogeneous one that may have different roles at different stages of the disease. Moreover, some degree of inflammation may be beneficial or protective for the brain, as it can facilitate the clearance of Aβ and NFTs, promote neurogenesis and repair, and modulate synaptic function. Therefore, it is important to identify the optimal timing, dosage, and target of anti-inflammatory interventions to achieve the desired outcomes without compromising the physiological functions of the immune system.

In conclusion, neuroinflammation is a key factor in the pathophysiology of AD that may offer novel opportunities for diagnosis and treatment. Further research is needed to elucidate the molecular mechanisms of neuroinflammation in AD, to identify biomarkers for monitoring neuroinflammatory status and response to therapy, and to develop safe and effective anti-inflammatory agents for AD prevention or management.

References:

– Heneka MT et al. Neuroinflammation in Alzheimer’s disease. Lancet Neurol. 2015;14(4):388-405.
– Heppner FL et al. Immune attack: the role of inflammation in Alzheimer disease. Nat Rev Neurosci. 2015;16(6):358-372.
– Wang X et al. Targeting neuroinflammation in Alzheimer’s disease: from mechanisms to therapeutics. Front Pharmacol. 2020;11:557269.