IL-34/CSF1R signaling modulates CNS immune cell development and impacts neurodegenerative disease progressionIL-34 Signaling Pathway Shows Complex Role in Brain Disorders

This systematic review synthesizes evidence regarding the IL-34/CSF1R signaling axis and its role in the central nervous system. The review focuses on how this pathway regulates the development, colonization, and functional differentiation of CNS-resident immune cells, specifically microglia and border-associated macrophages (BAMs).

Key findings indicate that IL-34 is involved in critical physiological processes, including synaptic pruning, neural circuit maturation, and the maintenance of blood-brain barrier integrity. Regarding specific neurological conditions, the review concludes that IL-34 modulates Alzheimer's disease, Parkinson's disease, multiple sclerosis, and ischemic stroke. However, the authors note that these effects are context-dependent, meaning IL-34 may provide neuroprotective effects or contribute to disease progression depending on the specific context.

Clinical application is currently limited by the nuanced, context-dependent nature of IL-34's effects. While the signaling axis is clearly involved in immune cell regulation and barrier integrity, its specific role in disease progression versus protection varies. Further research is needed to clarify these mechanisms in specific clinical scenarios.