Complement C3a receptor-mediated vascular dysfunction: A complex interplay between aging and neurodegeneration
© 2021, American Society for Clinical Investigation. Vascular dysfunction resulting in compromised blood-brain barrier (BBB) integrity is evident in aging and disease. Although the complement C3a/ C3a receptor (C3a/C3aR) axis influences normal brain aging and disease progression, the mechanisms governing endothelial C3aR-mediated neurovascular inflammation and BBB permeability remain unexplored. In this issue of the JCI, Propson et al. investigated endothelial C3a/ C3aR signaling in normal, aged, and neurodegenerative mouse models. Endothelial C3aR signaling modulated age-dependent increases in VCAM1, initiated peripheral lymphocyte infiltration, and enhanced microglial activity. Increased calcium release downstream of C3aR signaling disrupted the vascular endothelial cadherin (VE-cadherin) junctions, increased BBB permeability, and degraded vascular structure and function. Mice lacking C3aR (C3ar1-/-) and mice treated with a C3aR antagonist showed attenuated age-related microglial reactivity and neurodegeneration. These results confirm that complement-mediated signaling impacts vascular health and BBB function in normal aging and neurodegenerative disease, suggesting that complement inhibitors represent a therapeutic option for cerebral microvascular dysfunction.
Journal of Clinical Investigation
Digital Object Identifier (DOI)
Bhatia, Kanchan; Ahmad, Saif; Kindelin, Adam; and Ducruet, Andrew F., "Complement C3a receptor-mediated vascular dysfunction: A complex interplay between aging and neurodegeneration" (2021). Translational Neuroscience. 494.