Aspirin-triggered Resolvin D1 ameliorates activation of the NLRP3 inflammasome via induction of autophagy in a rat model of neuropathic pain

Abstract

Background: Several studies performed thus far indicate that neuroinflammation may be one of the mechanisms underlying the pathogenesis of neuropathic pain (NP). Autophagy, as an adaptive response, has been regarded as an active process of removing the inflammatory stimulus and restoring homeostatic balance. Resolution of inflammation is a biochemical process mediated by the so-called aspirin-triggered specialized proresolving lipid mediators (AT-SPMs), which are thought to exert protective effects in NP. Recent studies have proposed mechanisms in models of inflammatory disorders and showed a relationship between resolution of inflammation and autophagy. This study aimed to validate the functional effects of Aspirin-triggered Resolvin D1 (AT-RvD1) on in vitro and in vivo models of inflammation and to determine their roles in the regulation of autophagy and activation of the Nod-like receptor protein 3 (NLRP3) inflammasome signaling pathway.Methods: An NP model was established using L5-6 spinal nerve ligation (SNL) and a model of tumor necrosis factor alpha (TNF-α)-stimulated primary microglia was established to evaluate the effect of SPMs. Western blotting was used to detect the level of NLRP3 inflammasomes complexes proteins (NLRP3, ASC, and Caspase-1) and autophagy-related proteins (LC3B, and Beclin1). Immunofluorescence staining was used to understand the autophagy and NLRP3 inflammasome activation process. The behavioral changes in rats were analyzed using paw withdrawal thresholds (PWT) and paw withdrawal latency (PWL) test.Results: Our results showed that AT-SPMs significantly upregulated the activation of autophagy, which was characterized by an increase in the ratio of LC3B-II/I and accumulation of ATG5 and Beclin1. AT-RvD1 showed a dose-dependent decrease in the upregulated PWT and PWL induced by SNL and suppressed the expression of the NLRP3 inflammasome protein and the production of its corresponding downstream proinflammatory factors. Additionally, AT-RvD1 induced the activation of autophagy of the microglia and decreased the expression of the NLRP3 inflammasome protein and the accumulation of proinflammatory factors in TNF-ɑ-challenged microglia.Conclusion: Thus, these results showed that AT-RvD1 may be a potential alternative therapeutic strategy for the prevention or treatment of NP by inhibition of the NLRP3 inflammasome signaling pathway by targeting the induction of autophagy.

Amanita muscaria extract potentiates production of proinflammatory cytokines by dsRNA-activated human microglia

“…It is intriguing to speculate that autophagy maybe be playing an important role in HMC3 responses to poly(I:C) and induction of the inflammatory response. Recent data has shown that autophagy is involved in microglia induction of the important regulator of the Nod-like receptor protein 3 (NLRP3) inflammasome signaling pathway ( Wang et al, 2023b ), which is activated by a variety of TLR agonists including poly(I:C) and viruses. Autophagy alleviates sevoflurane-induced cognitive dysfunction in elderly rats ( Zhou et al, 2023 ) and autophagy is an important component of HIV-1 and drug-induced neuroinflammaging ( Sil et al, 2022 ).…”

Role of Resolvins in Inflammatory and Neuropathic Pain

“…Intrathecal injection of RvE1 or AT-RvD1 attenuated mechanical and thermal hyperalgesia [106,107]. In addition, the activities of microglia and various types of pro-inflammatory cytokine expression, such as IL-1β, IL-18, and TNF-α, were reduced by AT-RvD1 [107].…”

“…Additionally, unlike the inflammatory pain models, Rv studies using neuropathic pain models have confirmed changes in inflammatory factors and regulation of glial activation at the levels of the DRG and spinal cord (Table 2). Spinal cord [107] Rv treatment in neuropathic pain models alleviates pain responses such as mechanical and thermal hypersensitivity. Decreased inflammatory cytokines are confirmed at central and peripheral nerve system levels.…”

“…This neuropathic pain model has been widely used in studies on pain mechanisms and screening tests for analgesic candidates [114]. Intrathecal injection of RvE1 or AT-RvD1 attenuated mechanical and thermal hyperalgesia [106,107]. In addition, the activities of microglia and various types of pro-inflammatory cytokine expression, such as IL-1β, IL-18, and TNF-α, were reduced by AT-RvD1 [107].…”