Rat Cannabinoid Receptor 2, Macrophage (CNR2) Protein

Background

Cannabinoid Receptor 2 (CNR2), also known as CB2, is the second major receptor of the endocannabinoid system (ECS) and is predominantly expressed in immune cells, including macrophages, B-cells, T-cells, and microglia. Unlike CB1, CB2 is primarily located in the peripheral nervous system (PNS) and immune system, where it modulates inflammation, immune response, and tissue repair. Activation of CB2 by endocannabinoids like 2-AG or synthetic cannabinoids suppresses pro-inflammatory cytokine release, attenuating inflammatory responses and providing protection against autoimmune diseases and chronic inflammatory conditions such as rheumatoid arthritis and multiple sclerosis. CB2 also plays a critical role in regulating neuroinflammation and protecting neurons in neurodegenerative diseases like Alzheimer's disease, Parkinson's disease, and Huntington's disease by reducing oxidative stress and apoptosis. Additionally, CB2 is expressed in tissues like the liver, lungs, and bone, where it regulates processes like fibrosis, wound healing, and bone remodeling, highlighting its importance in diseases like liver fibrosis and osteoporosis. CB2 receptors are not associated with psychoactive effects, making them a promising therapeutic target for chronic pain, neuropathic pain, and cancer. CB2 agonists are actively being developed for clinical applications, particularly in inflammation, immune modulation, and cancer therapy, where CB2 activation can suppress tumor growth and metastasis. Ongoing research into CB2 biology underscores its potential as a non-psychoactive therapeutic target for a wide range of inflammatory, neurodegenerative, and immune-related disorders.