Abstract: Apelin receptor modulators can improve physical performance, slow progression of age-related frailty, and can reduce age-related muscle weakness in human patients. This disclosure provides methods for treating muscle conditions using a particular class of apelin receptor modulators (e.g., agonists). The muscle condition can be an age-related muscle condition. Also provided is a method for maintaining and/or increasing muscle mass, muscle function, and/or muscle strength in an elderly subject by administration of the apelin receptor modulator. In some embodiments, the apelin receptor modulator (e.g., agonist) is BGE-105, or a pharmaceutically acceptable salt thereof.

Abstract: This disclosure provides methods for using a particular class of apelin receptor modulators to reduce blood-brain barrier (BBB) permeability in a subject in need thereof, and in particular methods of treatment for a variety of disorders, conditions, and diseases associated with and related to increased BBB permeability. This disclosure also provides methods for using a particular class of apelin receptor modulators to treat a neurodegenerative disease, delirium, and/or dementia in a subject in need thereof. This disclosure also provides methods for using a particular class of apelin receptor modulators to reduce neuroinflammation in a subject in need thereof. In some embodiments, the apelin receptor modulator (e.g., agonist) is BGE-105, or a pharmaceutically acceptable salt thereof.