Irisin: A Multifaceted Hormone Bridging Exercise and Disease Pathophysiology

Area of Science:

• Endocrinology
• Exercise Physiology
• Neuroscience

Background:

• Fibronectin domain-containing protein 5 (FNDC5), known as irisin, is an exercise-induced hormone with potential therapeutic applications.
• Irisin levels are typically elevated in healthy states but decrease in various disease conditions.

Purpose of the Study:

• To review the multifaceted therapeutic potential of irisin across diverse pathophysiological conditions.
• To explore irisin's role in metabolic disorders, bone health, and neurodegenerative diseases, particularly Alzheimer's disease (AD).

Main Methods:

• Review of existing literature on irisin's biological functions and therapeutic effects.
• Analysis of irisin's impact on muscle-adipose communication, mitochondrial function, oxidative stress, and inflammatory pathways.

Main Results:

• Irisin enhances insulin sensitivity, metabolic balance, and mitochondrial function, while reducing oxidative stress.
• It promotes osteogenesis, mitigates bone loss, and exhibits anti-inflammatory effects by inhibiting NF-κB signaling.
• In the brain, irisin reduces amyloid-β toxicity and inflammation, enhances BDNF signaling, and may alleviate neuropsychiatric symptoms.

Conclusions:

• Irisin acts as a crucial link in the muscle-bone-brain axis, highlighting its systemic health benefits.
• Its diverse therapeutic potential positions irisin as a promising target for preventing and treating Alzheimer's disease and related disorders.