Recombinant interleukin-4 alleviates mechanical allodynia via injury-induced interleukin-4 receptor alpha in spinal microglia in a rat model of neuropathic pain

Antagonism of β-arrestins in IL-4-driven microglia reactivity via the Samd4/mTOR/OXPHOS axis in Parkinson's disease

Interleukin-4 (IL-4)-exposed microglia acquire neuroprotective properties, but their functions and regulation in Parkinson's disease (PD) are poorly understood. In this study, we demonstrate that IL-4 enhances anti-inflammatory microglia reactivity, ameliorates the pathological features of PD, and reciprocally affects expression of β-arrestin 1 and β-arrestin 2 in microglia in PD mouse models. We also show that manipulation of two β-arrestins produces contrary effects on the anti-inflammatory states and neuroprotective action of microglia induced by IL-4 in vivo and in vitro. We further find that the functional antagonism of two β-arrestins is mediated through sequential activation of sterile alpha motif domain containing 4 (Samd4), mammalian target of rapamycin (mTOR), and mitochondrial oxidative phosphorylation (OXPHOS). Collectively, these data reveal opposing functions of two closely related β-arrestins in regulating the IL-4-induced microglia reactivity via the Samd4/mTOR/OXPHOS axis in PD mouse models and provide important insights into the pathogenesis and therapeutics of PD.

Nicotinic regulation of microglia: potential contributions to addiction

Clinical and preclinical studies have identified immunosuppressive effects of nicotine, with potential implications for treating nicotine addiction. Here we review how nicotine can regulate microglia, the resident macrophages in the brain, and corresponding effects of nicotine on neuroimmune signaling. There is significant evidence that activation of α7 nicotinic acetylcholine receptors (nAChRs) on microglia can trigger an anti-inflammatory cascade that alters microglial polarization and activity, cytokine release, and intracellular calcium concentrations, leading to neuroprotection. These anti-inflammatory effects of nicotine-dependent α7 nAChR signaling are lost during withdrawal, suggesting that neuroimmune signaling is potentiated during abstinence, and thus, heightened microglial activity may drive circuit disruption that contributes to withdrawal symptoms and hyperkatifeia. In sum, the clinical literature has highlighted immunomodulatory effects of nicotine and the potential for anti-inflammatory compounds to treat addiction. The preclinical literature investigating the underlying mechanisms points to a role of microglial engagement in the circuit dysregulation and behavioral changes that occur during nicotine addiction and withdrawal, driven, at least in part, by activation of α7 nAChRs on microglia. Specifically targeting microglial signaling may help alleviate withdrawal symptoms in people with nicotine dependence and help to promote abstinence.

Pain-resolving immune mechanisms in neuropathic pain

Interactions between the immune and nervous systems are of central importance in neuropathic pain, a common and debilitating form of chronic pain caused by a lesion or disease affecting the somatosensory system. Our understanding of neuroimmune interactions in pain research has advanced considerably. Initially considered as passive bystanders, then as culprits in the pathogenesis of neuropathic pain, immune responses in the nervous system are now established to underpin not only the initiation and progression of pain but also its resolution. Indeed, immune cells and their mediators are well-established promoters of neuroinflammation at each level of the neural pain pathway that contributes to pain hypersensitivity. However, emerging evidence indicates that specific subtypes of immune cells (including antinociceptive macrophages, pain-resolving microglia and T regulatory cells) as well as immunoresolvent molecules and modulators of the gut microbiota-immune system axis can reduce the pain experience and contribute to the resolution of neuropathic pain. This Review provides an overview of the immune mechanisms responsible for the resolution of neuropathic pain, including those involved in innate, adaptive and meningeal immunity as well as interactions with the gut microbiome. Specialized pro-resolving mediators and therapeutic approaches that target these neuroimmune mechanisms are also discussed.

The Clinical Efficacy and Economic Benefits of Recombinant Human Thrombopoietin for the Treatment of Chemotherapy or Chemoradiotherapy-Induced Thrombocytopenia

Even though cytopenia caused by either chemotherapy or radiotherapy is a common complication in cancer patients, chemoradiotherapy remains an essential treatment for the majority of patients. The purpose of this study was to look into the clinical efficacy and cost-effectiveness of recombinant human thrombopoietin (rhTPO) in treating chemo- or chemoradiotherapy-induced grade II, III, and IV thrombocytopenia. From December 2019 to November 2020, 233 lung cancer patients admitted to our hospital with chemotherapy- or chemoradiotherapy-induced thrombocytopenia were enrolled and treated with rhTPO. The study's findings revealed a significant disparity in the use of concurrent chemoradiotherapy in patients with grade II, III, and IV thrombocytopenia. All costs, including rhTPO treatment costs, platelet costs, drug costs, and nondrug costs, tended to rise as the severity of thrombocytopenia increased. In the treatment of chemotherapy or radiotherapy-induced thrombocytopenia, rhTPO has shown good clinical efficacy. In the treatment of grade II thrombocytopenia, rhTPO has a favorable economic evaluation. As a result, early intervention and thrombocytopenia treatment should be provided, which warrants further clinical investigation.

Hydrogen-rich Saline Alleviated the Hyperpathia and Microglia Activation via Autophagy Mediated Inflammasome Inactivation in Neuropathic Pain Rats

Neuropathic pain is a complication after a spinal nerve injury. The inflammasomes are now identified to be responsible for triggering inflammation in neuropathic pain. Autophagy participates in the process of neuropathic pain and can regulate the inflammasome activation in different diseases. Our previous research reported that hydrogen exerted a protective effect against neuropathic pain. Therefore, we focused on the mechanism and role of autophagy and inflammasome, by which hydrogen alleviated the hyperpathia induced by neuropathic pain. The results showed that neuropathic pain stimulated activation of inflammasome NLRP3 and autophagy pathway in the microglial cells of the spinal cord. The inhibition of NLRP3 inhibited the hyperpathia induced by spinal nerve litigation surgery. The absence of autophagy aggravated the inflammasome activity and hyperpathia. Hydrogen promoted autophagy related protein expression, inhibited the inflammasome NLRP3 pathway activation, and relieved the hyperpathia induced by neuropathic pain. Hydrogen treatment could alleviate hyperpathia by autophagy-mediated NLRP3 inactivation.