Photo-downregulation of SIRT4 mitigates aging in mice by enhancing H3K9ac via fatty acid metabolism.

Photo-downregulation of SIRT4 in aged mice increases H3K9ac levels by activating fatty acid metabolism, thereby mitigating cellular aging.

• Why it matters: Understanding how to reverse or slow aging processes is crucial for improving healthspan, as disrupted gene regulation and mitochondrial decline contribute to senescence in tissues.
• What they did: Researchers exposed aged mice to red light, observed reduced SIRT4 protein levels in keratinocytes, and measured subsequent changes in histone acetylation, metabolism, and gene expression.
• The result: The reduction of SIRT4 enhances fatty acid oxidation and H3K9ac, activates lipid metabolism genes, and ultimately alleviates aging-related cellular phenotypes through metabolic and gene expression regulation.