The suppressor of cytokine signalling 2 (SOCS2), traumatic brain injury and microglial/macrophage regulation

M2 macrophage exosome-derived lncRNA AK083884 protects mice from CVB3-induced viral myocarditis through regulating PKM2/HIF-1α axis mediated metabolic reprogramming of macrophages

Viral myocarditis (VM) is a clinically common inflammatory disease. Accumulating literature has indicated that M2 macrophages protect mice from Coxsackievirus B3 (CVB3)-induced VM. However, mechanisms that underlie M2 macrophages alleviating myocardial inflammation remain largely undefined. We found that M2 macrophage-derived exosomes (M2-Exo) can effectively attenuate VM. The long non-coding RNA (lncRNA) AK083884 in M2-Exo was found to be involved in the regulation of macrophage polarization by exosome lncRNA sequencing combined with in vitro functional assays. M2-Exo-derived AK083884 promotes macrophage M2 polarization and protects mice from CVB3-induced VM. Furthermore, we identified pyruvate kinase M2 (PKM2) as a protein target binding to AK083884 and found that PKM2 knockdown could promote macrophages to polarize to M2 phenotype. Intriguingly, functional assay revealed that downregulation of AK083884 promotes metabolic reprogramming in macrophages. In addition, co-immunoprecipitation was performed to reveal AK083884 could interact with PKM2 and inhibition of AK083884 can facilitate the binding of PKM2 and HIF-1α. Collectively, our findings uncovered an important role of M2-Exo-derived AK083884 in the regulation of macrophage polarization through metabolic reprogramming, identified a new participant in the development of VM and provided a potential clinically important therapeutic target.

CB1 Cannabinoid Receptor is a Target for Neuroprotection in Light Induced Retinal Degeneration

In the last few years, an increasing interest in the neuroprotective effect of cannabinoids has taken place. The aim of the present work was to study the effects of modulating cannabinoid receptor 1 (CB1) in the context of light induced retinal degeneration (LIRD), using an animal model that resembles many characteristics of human age-related macular degeneration (AMD) and other degenerative diseases of the outer retina. Sprague Dawley rats (n = 28) were intravitreally injected in the right eye with either a CB1 agonist (ACEA), or an antagonist (AM251). Contralateral eyes were injected with respective vehicles as controls. Then, rats were subjected to continuous illumination (12,000 lux) for 24 h. Retinas from 28 animals were processed by GFAP-immunohistochemistry (IHC), TUNEL technique, Western blotting (WB), or qRT-PCR. ACEA-treated retinas showed a significantly lower number of apoptotic nuclei in the outer nuclear layer (ONL), lower levels of activated Caspase-3 by WB, and lower levels of glial reactivity by both GFAP-IHC and WB. qRT-PCR revealed that ACEA significantly decreased the expression of Bcl-2 and CYP1A1. Conversely, AM251-treated retinas showed a higher number of apoptotic nuclei in the ONL, higher levels of activated Caspase-3 by WB, and higher levels of glial reactivity as determined by GFAP-IHC and WB. AM251 increased the expression of Bcl-2, Bad, Bax, Aryl hydrocarbon Receptor (AhR), GFAP, and TNFα. In summary, the stimulation of the CB1 receptor, previous to the start of the pathogenic process, improved the survival of photoreceptors exposed to LIRD. The modulation of CB1 activity may be used as a neuroprotective strategy in retinal degeneration and deserves further studies.

Long-term neuropathic pain behaviors correlate with synaptic plasticity and limbic circuit alteration: a comparative observational study in mice

ABSTRACT

Neuropathic pain has long-term consequences in affective and cognitive disturbances, suggesting the involvement of supraspinal mechanisms. In this study, we used the spared nerve injury (SNI) model to characterize the development of sensory and aversive components of neuropathic pain and to determine their electrophysiological impact across prefrontal cortex and limbic regions. Moreover, we evaluated the regulation of several genes involved in immune response and inflammation triggered by SNI. We showed that SNI led to sensorial hypersensitivity (cold and mechanical stimuli) and depressive-like behavior lasting 12 months after nerve injury. Of interest, changes in nonemotional cognitive tasks (novel object recognition and Y maze) showed in 1-month SNI mice were not evident normal in the 12-month SNI animals. In vivo electrophysiology revealed an impaired long-term potentiation at prefrontal cortex-nucleus accumbens core pathway in both the 1-month and 12-month SNI mice. On the other hand, a reduced neural activity was recorded in the lateral entorhinal cortex-dentate gyrus pathway in the 1-month SNI mice, but not in the 12-month SNI mice. Finally, we observed the upregulation of specific genes involved in immune response in the hippocampus of 1-month SNI mice, but not in the 12-month SNI mice, suggesting a neuroinflammatory response that may contribute to the SNI phenotype. These data suggest that distinct brain circuits may drive the psychiatric components of neuropathic pain and pave the way for better investigation of the long-term consequences of peripheral nerve injury for which most of the available drugs are to date unsatisfactory.