Review of the Role of TRAF7 in Brain Endothelial Integrity and Cerebrovascular Aging

Tumor necrosis factor (TNF) receptor-associated factor 7 (TRAF7) is a signal transducer in the TNF receptor superfamily. TRAF7 is unique among its superfamily in that it does not contain a TRAF-C domain but does contain WD-40 domains. TRAF7 interacts with mitogen-activated protein kinases (MAPK), which are known regulators of inflammation and shear stress response. Notably, these molecular interactions have profound implications for the function of brain endothelial cells (ECs), which are pivotal for sustaining the integrity of the blood-brain barrier (BBB), orchestrating neurovascular coupling (NVC), and modulating the vascular architecture. By directly influencing MAPK signaling pathways, particularly the shear stress-responsive MAPK kinase kinase 3 (MEKK3)-MAPK kinase 5 (MEK5)-extracellular-regulated protein kinase 5 (ERK5) cascade, TRAF7 contributes to vascular homeostasis, as exemplified by its role in phosphorylating ERK5. Such molecular events underpin the capacity of brain ECs to regulate substance exchange, adjust blood flow in response to neural activity, and maintain efficient cerebral perfusion, all of which are essential for preserving brain health and cognitive performance. By synthesizing the current evidence regarding TRAF7's molecular functions and its impact on brain endothelial integrity, cerebrovascular aging, and exploring implications for therapeutic strategies targeting vascular dysfunction in the aging brain, this review fills a crucial gap in the literature. Given the limited number of original studies directly addressing these contexts, the review will integrate broader insights from related literature to provide a foundational overview for future research in this developing field. The culmination of this literature will provide a rationale for the development of novel TRAF7-targeted therapies to restore vascular integrity in the context of aging, which could maintain cognitive health. Although TRAF7 has been implicated in regulating endothelial permeability during inflammation, its precise functions in brain ECs and the subsequent effects on cerebrovascular structure and cognitive function remain to be fully elucidated.