Emerging Potential of Ras-proximate-1 (Rap1) in Mediating Neurodegenerative Diseases

Neurodegenerative diseases have posed a rising global threat to the aging population, presenting structural and functional impairments in the central nervous system. These progressive disorders, which affect the brain and spinal cord, develop due to the continuous loss of neurons and myelin sheaths. Such specific pathophysiological changes lead to neurological dysfunction in Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and Huntington's disease, resulting in typical motor dysfunctions and cognitive disorders, as well as symptoms like behavioral abnormalities and personality changes. To date, despite various treatments attempting to manage these symptoms, patients' quality of life remains severely deteriorated. A few effective therapeutics are available to mitigate the progression of neurodegenerative injuries. Increasing attention is now focused on molecular regulatory mechanisms, particularly the association between immune regulation and the neurovascular unit. A critical component in this process is Ras-proximate-1 (Rap1), a small Guanosine Triphosphatase (GTPase). Rap1 is determined to regulate glia-mediated immunoinflammatory responses, vascular endothelial function, and neuronal activity. It also modulates synaptic plasticity and mitochondrial function via autophagy-dependent modulation, which are significantly impacted during neuronal degeneration. Additionally, signaling pathways, including PI3K/Akt and ERK, are identified as its downstream effectors. Furthermore, by mediating the permeability of the blood-brain barrier, Rap1 probably influences neuroimmune-vascular modulation throughout the development of neurological disorders. In this review, we investigate recent studies to explore the emerging therapeutic potential of Rap1 in the inflammation-related regulation within neurodegenerative diseases. We also discuss novel treatments and possible targets, including natural medicines and genetic modulation, to enhance therapeutic effects and improve prognosis.