Retinoic acid metabolism pathway (RA metabolism)

The retinoic acid metabolism pathway is a critical biochemical cascade responsible for the synthesis, transport, and degradation of retinoic acid (RA), the active metabolite of vitamin A [1.1.1, 1.2.1]. It involves key enzymes such as retinol dehydrogenases (RDHs) and retinaldehyde dehydrogenases (ALDH1A family) for synthesis, and cytochrome P450 enzymes (specifically CYP26A1, B1, and C1) for catabolism [1.1.1, 1.2.4]. RA acts as a potent signaling molecule by binding to nuclear receptors (RARs and RXRs) to regulate the transcription of hundreds of genes involved in cell differentiation, embryonic development, and immune function [1.2.1, 1.3.2]. Dysregulation of this pathway is linked to various pathologies, including acute promyelocytic leukemia (APL), where RA therapy is a standard of care, and dermatological conditions like acne and psoriasis [1.1.1, 1.3.4]. Pharmacological intervention targets this pathway through exogenous retinoids or by inhibiting RA degradation using Retinoic Acid Metabolism Blocking Agents (RAMBAs) [1.1.1, 1.3.3]. Notable safety concerns include severe teratogenicity and differentiation syndrome, necessitating careful clinical management [1.1.1, 1.3.2].

Other names

Vitamin A metabolismRetinoid metabolismRetinoic acid signaling pathwayRetinoid signaling

Agonism of nuclear retinoic acid receptors (RARs and RXRs) to induce gene transcription; inhibition of CYP26 enzymes to prevent retinoic acid degradation; inhibition of ALDH enzymes to block retinoic acid synthesis [1.1.1, 1.3.3].