Recent evidence indicates that ultraviolet (UV) exposure of the skin can affect brain functions such as learning and memory, addictive behavior, and hippocampal neurogenesis. These changes are closely associated with hippocampal function, which plays a pivotal role in learning and memory formation. However, the molecular mechanisms underlying these UV-induced skin-brain interactions remain unclear. To elucidate the molecular signature associated with UV-induced neurobehavioral changes, we analyzed the hippocampal transcriptome in a well-established mouse skin aging model, which showed thickened skin and impaired hippocampal memory. Transcriptome analysis revealed that significantly downregulated genes in UV-irradiated mice are enriched in neuroimmune-related signaling pathways. Furthermore, cell-type analysis showed that DEGs are also enriched in microglia. Consistently, immunofluorescence imaging showed an increased number of Iba1-positive microglia in the hippocampi of UV-irradiated mice. Collectively, our findings highlight that chronic UV irradiation of the skin causes significant changes in the neuroimmune system in the hippocampus, accompanied by microglial dysfunction and cognitive impairment.
Bibliographical noteFunding Information:
This research was supported by a grant of the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health and Welfare, Republic of Korea (HP20C0220) and the Cooperative Research Program of Basic Medical Science and Clinical Science from Seoul National University College of Medicine (800- 20200295).
© 2022, The Author(s).
- Microglia dysfunction
- Ultraviolet irradiation
ASJC Scopus subject areas
- Molecular Biology
- Cellular and Molecular Neuroscience