Molecular profiling of the light-induced alternations in the microvasculature of the developing visual cortex

초록

Early in life, light plays a crucial role among the environmental factors in accelerating development. Mice typically open their eyes around 14 days after birth, and exposure to light triggers molecular and structural changes in the developing brain. This sensory experience induces changes in neuronal activity that in turn modulate angiogenesis, hemodynamics, and blood-brain barrier function. These changes occur through the direct interactions of neurotransmitters, neuropeptides, and neuromodulators on brain endothelial cell (BEC) receptors or indirectly via astrocytes or pericytes. Interestingly, the response of blood vessels to neuronal activation varies depending on the subset of activated neurons, brain region, and age. However, much less is known about the molecular changes in brain endothelial cells following sensory experience during development. In this study, we developed an optimized protocol for BEC-specific translatome analysis by modifying the original RiboTag method to isolate of highly pure BEC-enriched translating mRNA pools. Using this method, we successfully purified BEC-specific translating mRNA pools after neuronal activation with light-mediated natural stimuli (before and after eye opening (P10 and P30)). We identified 560 downregulated genes and 666 upregulated genes in BECs after neuronal stimulation by light and validated the top genes that exhibited high expression and dynamic changes in BECs. Through bioinformatic analysis of translatome datasets derived from natural light-mediated stimuli, we identified 32 genes that overlapped with the previous study in visual cortex BECs. Among these genes, HSP27, Mal, and Slc16a1 are prominently regulated by light stimulation and are exclusively expressed in BECs. We confirmed their light-sensitive expression using dark rearing experiments. Taken together, we have identified specific pool of brain endothelial cell genes that dynamically respond to light stimuli, thereby advancing our understanding of neurovascular interaction mechanisms.