Study Identifies Noncircadian BMAL1-YAP Pathway as Driver of Epidermal Inflammaging

A newly discovered noncircadian cooperation between BMAL1 and YAP in aged skin reveals a transcriptional rewiring that amplifies persistent tissue inflammation, presenting novel therapeutic targets to restore epidermal homeostasis.

A study published in Nature Aging reported that aged murine epidermis engages a previously uncharacterized cooperation between the clock protein BMAL1 and the mechanosensitive cofactor YAP.

In young skin, BMAL1 and YAP partner at enhancer regions to regulate epidermal identity genes independently of the circadian clock; however, in aged skin, this binding undergoes a functional shift to selectively amplify the expression of inflammation-related genes, partly coregulated by NF-κB.

The researchers demonstrated that age-associated pro-inflammatory IL-17 signaling activates YAP in a Hippo-independent manner, promoting noncanonical phosphorylation of YAP (P-Y357).

Genetic loss of BMAL1 in the epidermis resulted in decreased YAP binding and subsequent reduction in the expression of their shared inflammatory target genes, validating the pathway's functional role.

Persistent low-grade inflammation ('inflammaging') is a central driver of age-associated epidermal decline, resulting in compromised skin barrier function, inefficient wound healing, and elevated oxidative stress.

This study shifts the understanding of BMAL1 beyond its traditional role as a circadian rhythm regulator, defining it as a noncircadian cofactor that controls adult tissue homeostasis and pathologic transcriptional remodeling during aging.

Identifying the molecular nodes that switch cell-identity pathways into pro-inflammatory cascades offers concrete therapeutic entry points to counter chronic inflammation and restore tissue integrity in aged skin.

The discovery provides a mechanistically precise set of targets (the BMAL1-YAP complex, IL-17, and Hippo-independent YAP activation) for biopharmaceutical pipelines focused on dermatological senescence, wound healing, and tissue rejuvenation.

These findings support the clinical rationale for target discovery platforms targeting transcriptional and epigenetic resetting, confirming that restoring young-like enhancer landscapes can suppress chronic age-related inflammation.

Preclinical development of small molecules or biologics designed to disrupt the aged BMAL1-YAP transcriptional complex or inhibit upstream IL-17-mediated YAP activation to evaluate their efficacy in restoring skin barrier function and accelerating wound healing in aged in vivo models.