C/EBPδ as a Regulatory Node in Adipocytes: Roles in Differentiation, Metabolism, and Immune Function.

CCAAT/enhancer-binding protein δ (C/EBPδ) is a rapidly responsive transcription factor that occupies an important regulatory position in adipocytes. Induced during the early stage of adipocyte differentiation, C/EBPδ integrates hormonal, inflammatory, metabolic, and stress-related cues and contributes to the coordination of downstream transcriptional and functional programs. Beyond its role in the initiation of differentiation, C/EBPδ is also involved in adipogenic progression, metabolic regulation, and immune-related functions in adipocytes. Current evidence indicates that C/EBPδ participates in early adipogenic regulatory networks, contributes to lipid metabolic programs, and is associated with immune-regulatory processes linked to lipid antigen presentation. Notably, the biological output of C/EBPδ is strongly shaped by tissue type, developmental stage, and microenvironmental context, ranging from promotion of adipogenic differentiation to regulation of inflammatory, metabolic, and adaptive stress responses under distinct physiological and pathological conditions. This review summarizes the upstream regulatory network, downstream functional framework, and context-dependent roles of C/EBPδ in adipocytes, and further discusses its potential relevance to adipose-related diseases as well as the opportunities and challenges for future precision intervention strategies.