Inflammation in pathogenesis of chronic pain: Foe and friend

Abstract

Chronic pain is a refractory health disease worldwide causing an enormous economic burden on individuals and society. Accumulating evidence suggests that inflammation in the peripheral nervous system (PNS) and central nervous system (CNS) is the major factor in the pathogenesis of chronic pain. The inflammation in the early- and late phase may have distinctive effects on the initiation and resolution of pain, which can be viewed as friend or foe. On the one hand, painful injuries lead to the activation of glial cells and immune cells in the PNS, releasing pro-inflammatory mediators, which contribute to the sensitization of nociceptors, leading to chronic pain; neuroinflammation in the CNS drives central sensitization and promotes the development of chronic pain. On the other hand, macrophages and glial cells of PNS and CNS promote pain resolution via anti-inflammatory mediators and specialized pro-resolving mediators (SPMs). In this review, we provide an overview of the current understanding of inflammation in the deterioration and resolution of pain. Further, we summarize a number of novel strategies that can be used to prevent and treat chronic pain by controlling inflammation. This comprehensive view of the relationship between inflammation and chronic pain and its specific mechanism will provide novel targets for the treatment of chronic pain.

Contrasting roles of Beclin-1 in pain hypersensitivity and anxiety-like behaviours in a mouse model of neuropathic pain

“…Furthermore, we wanted to test if disruption of beclin-1 protein also affects pain-induced anxiety-like behaviours as chronic pain is often accompanied by mental health disorders in a clinical setting 17 . Inflammation in patients with chronic neuropathic pain has been linked to the onset of anxiety and other mental health-related symptoms 28 . We wanted to test if the transgenic mice line, who have been mutated to have reduced autophagy and possibly decreased inflammation, would show us such anxiety-like symptoms at a greater level than the wildtypes with SNI model of chronic neuropathic pain when subjected to experiments.…”

Anti-inflammatory and analgesic properties of Polyphyllin VI revealed by network pharmacology and RNA sequencing

“…Recent decades revealed the vital role of neutrophils, macrophages, and glial cells in the maintenance and development of chronic pain [22][23][24] . These immune cells and neuroglia are affected by nociceptor sensitization caused by nociceptive stimulation and in ammatory mediators, leading to neuroin ammation [25] . The occurrence of neuroin ammation depends on the release of cytokines and chemokines by reactive glial cells and system immune cells.…”

The Role of Glial Cells in Different Phases of Migraine: Lessons from Preclinical Studies

“…An important body of literature confirms the contribution of glial cells in the chronification of different pain conditions [ 23 , 24 , 84 , 85 , 86 , 87 , 88 , 89 , 90 ]. Moreover, reversing the injury-induced changes in glial cells using different approaches has been shown to reduce, or even abolish, pain behaviour in different rodent models [ 23 , 28 , 91 ].…”