Astrocyte secretome remodeling under iron deficiency: potential implications for brain iron homeostasis.

The brain is the most metabolically active organ in the body and has a high demand for iron. Iron deficiency impairs brain function and is linked to various neurological disorders. To maintain iron homeostasis, astrocytes respond to iron levels and signal brain microvascular endothelial cells (BMVECs), which regulate iron import into the brain. However, the specific signaling molecules released by astrocytes remain largely unknown. In this study, we addressed this by performing a global proteomic analysis of the secretome of primary mouse astrocytes cultured under iron-deficient conditions. Quantitative mass spectrometry demonstrated significant remodeling of the astrocyte secretome in response to iron deficiency, affecting critical pathways related to metabolic reprogramming, stress responses, and cellular communication. We identified specific secreted factors with potential roles in paracrine signaling, with their secretion supported by prediction analysis. Our analysis also revealed novel condition-specific proteins. These findings provide new insights into astrocyte communication under iron stress and its potential influence on iron availability at the blood-brain barrier. This study establishes a foundation for future investigations into astrocyte-secreted factors and their roles in neurological diseases associated with iron dysregulation.