[Role of microglia in inflammatory demyelination lesion in the central nervous system]

Targeting p53 for neuroinflammation: New therapeutic strategies in ischemic stroke

Ischemic stroke (IS) is characterized by high incidence, high recurrence, and high mortality and places a heavy burden on society and families. The pathological mechanisms of IS are complex, among which secondary neurological impairment mediated by neuroinflammation is considered to be the main factor in cerebral ischemic injury. At present, there is still a lack of specific therapies to treat neuroinflammation. The tumor suppressor protein p53 has long been regarded as a key substance in the regulation of the cell cycle and apoptosis in the past. Recently, studies have found that p53 also plays an important role in neuroinflammatory diseases, such as IS. Therefore, p53 may be a crucial target for the regulation of the neuroinflammatory response. Here, we provide a comprehensive review of the potential of targeting p53 in the treatment of neuroinflammation after IS. We describe the function of p53, the major immune cells involved in neuroinflammation, and the role of p53 in inflammatory responses mediated by these cells. Finally, we summarize the therapeutic strategies of targeting p53 in regulating the neuroinflammatory response after IS to provide new directions and ideas for the treatment of ischemic brain injury.

Transcription cofactor GRIP1 differentially affects myeloid cell-driven neuroinflammation and response to IFN-β therapy

Macrophages (MФ) and microglia (MG) are critical in the pathogenesis of multiple sclerosis (MS) and its mouse model, experimental autoimmune encephalomyelitis (EAE). Glucocorticoids (GCs) and interferon β (IFN-β) are frontline treatments for MS, and disrupting each pathway in mice aggravates EAE. Glucocorticoid receptor-interacting protein 1 (GRIP1) facilitates both GR and type I IFN transcriptional actions; hence, we evaluated the role of GRIP1 in neuroinflammation. Surprisingly, myeloid cell-specific loss of GRIP1 dramatically reduced EAE severity, immune cell infiltration of the CNS, and MG activation and demyelination specifically during the neuroinflammatory phase of the disease, yet also blunted therapeutic properties of IFN-β. MФ/MG transcriptome analyses at the bulk and single-cell levels revealed that GRIP1 deletion attenuated nuclear receptor, inflammatory and, interestingly, type I IFN pathways and promoted the persistence of a homeostatic MG signature. Together, these results uncover the multifaceted function of type I IFN in MS/EAE pathogenesis and therapy, and an unexpectedly permissive role of myeloid cell GRIP1 in neuroinflammation.

Animal Venom Peptides as a Treasure Trove for New Therapeutics Against Neurodegenerative Disorders

BACKGROUND

Neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, and cerebral ischemic stroke, impose enormous socio-economic burdens on both patients and health-care systems. However, drugs targeting these diseases remain unsatisfactory, and hence there is an urgent need for the development of novel and potent drug candidates.

METHODS

Animal toxins exhibit rich diversity in both proteins and peptides, which play vital roles in biomedical drug development. As a molecular tool, animal toxin peptides have not only helped clarify many critical physiological processes but also led to the discovery of novel drugs and clinical therapeutics.

RESULTS

Recently, toxin peptides identified from venomous animals, e.g. exenatide, ziconotide, Hi1a, and PcTx1 from spider venom, have been shown to block specific ion channels, alleviate inflammation, decrease protein aggregates, regulate glutamate and neurotransmitter levels, and increase neuroprotective factors.

CONCLUSION

Thus, components of venom hold considerable capacity as drug candidates for the alleviation or reduction of neurodegeneration. This review highlights studies evaluating different animal toxins, especially peptides, as promising therapeutic tools for the treatment of different neurodegenerative diseases and disorders.

Microglia heterogeneity along a spatio-temporal axis: More questions than answers

Microglia are resident macrophages of the central nervous system; they arise during early embryonic development and persist throughout adulthood. These unique cells provide developmental support, contribute to adult brain homeostasis and impart immune protection during infection. Dysregulated microglia are implicated in the pathophysiology of several neurological disorders, including Alzheimer disease, and as such, a better understanding of their regulation and function is required for rational therapeutic design. Recent studies have highlighted the various heterogeneous aspects of microglia, such as their wide differentiation spectrum from early embryogenesis to adulthood, their location in different brain regions and their responses to ageing, infection and inflammation. In this review, we discuss microglial heterogeneity in time and space and highlight the remaining questions arising from such heterogeneity.