The role of amylin, a gut–brain axis hormone, in metabolic and neurological disorders

Amylin, also known as islet amyloid polypeptide (IAPP), is a pancreatic β-cell peptide hormone involved in satiation and control food intake. It is also produced in smaller quantities by neurons, the gastrointestinal tract, and spinal ganglia. Numerous studies have revealed that patients with type 2 diabetes mellitus (T2DM) and cognitive deficits exhibit IAPP deposits in the pancreas, brain, and blood vessels. IAPP has also been shown to exert neuroprotective effects against Alzheimer's disease (AD) and cognitive impairments. The objective of this review paper is to provide recent information about the pathophysiological roles of IAPP in metabolic and in neurological disorders, and its potential as a druggable target. We have reviewed preclinical and clinical human and animal research studies of IAPP. We discuss the IAPP structure, its receptors, and its physiological functions in metabolism, satiation, adiposity, obesity, and in the brain. Then we discuss its role in metabolic and neurological disorders like diabetes, obesity, bone disorder, neurodegeneration, cerebrovascular disorders, depression, alcohol use disorder, epilepsy, and in ovarian cysts. Overall, this review provides information on the progress of research into the roles of IAPP and its receptor in food intake, energy homeostasis, glucose regulation, satiation, and its role in metabolic and neurological disorders making it a potential target for therapeutic approaches. This review also suggests that the utilization of rodents overexpressing human IAPP in neurodegeneration models may unearth some significant therapeutic potentials for neurological disorders.