Crossing Pathological Boundaries: Multi-Target Restoration of the Neurovascular Unit in Alzheimer's and Vascular Dementia—From Modern Therapeutics to Traditional Chinese Medicine

Alzheimer's disease (AD) and vascular dementia (VD) are the two most common forms of dementia, and they share common mechanisms, especially in regard to neurovascular dysfunction. There has been increasing evidence that the disruption of the neurovascular unit (NVU), which consists of endothelial cells, pericytes, astrocytes, microglia, neurons, and basement membrane, is one of the key early events in both AD and VD. The objective of this review is to summarize the structure and physiological function of the NVU, then discuss the pathological remodeling of the NVU in AD and VD and finally, show emerging evidence of multi-target approaches that restore the NVU and neurovascular protection. We begin with a description of the structure, and dietary regulatory roles of the NVU in cerebral homeostasis, especially related to Aβ, the blood-brain barrier (BBB), and neurovascular coupling (NVC). The NVU is then related to the pathological events that cause AD and VD, specifically to impaired Aβ clearance, inflammatory cascades, oxidative stress, and neurovascular uncoupling. Finally, the discussion focuses on a multi-target approach involving exercise, estrogen therapy, mesenchymal stem cells/exosomes, remote ischemic conditioning (RIC), and mindfulness meditation, and analyzes its implications for recovering NVU structure and function. We also discuss the concept of traditional Chinese medicine (TCM) approaches associated with NVU modulation with herbal formulas, traditional Chinese exercises and acupuncture, which has integrative pathways for MVU modulation. NVU dysfunction has a significant and converging impact on the development of both AD and VD. There is considerable support for multi-pathway neurovascular unit targeting, which should show a significant delay in cognitive decline. Incorporating multi-modal evidence from contemporary and traditional medical systems could offer new insights for individualized, neurovascular-targeted therapy for dementia.