CCAAT/enhancer-binding protein delta (CEBPD), as an evolutionarily conserved protein in mammals, belongs to the CEBP transcription factor family, which modulates many biological processes. The diversity of CEBPD functions partly depends on the cell type and cellular context. Aberrant CEBPD expression and activity are associated with multiple organ diseases, including cardiovascular diseases. In this review, we describe the basic molecular biology of CEBPD to understand its expression regulation, modifications, and functions. Here, we summarize the recent advances in genetically modified animals with CEBPD. Finally, we discuss the contribution of CEBPD to cardiovascular diseases and highlight the strategies for developing novel therapies targeting CEBPD.

Cardiovascular disease (CVD) is recognized as the primary cause of mortality and morbidity on a global scale, and developing a clear treatment is an important tool for improving it. Cardiometabolic disorder (CMD) is a syndrome resulting from the combination of cardiovascular, endocrine, pro-thrombotic, and inflammatory health hazards. Due to their complex pathological mechanisms, there is a lack of effective diagnostic and treatment methods for cardiac metabolic disorders. Lactylation is a type of post-translational modification (PTM) that plays a regulatory role in various cellular physiological processes by inducing changes in the spatial conformation of proteins. Numerous studies have reported that lactylation modification plays a crucial role in post-translational modifications and is closely related to cardiac metabolic diseases. This article discusses the molecular biology of lactylation modifications and outlines the roles and mechanisms of lactylation modifications in cardiometabolic disorders, offering valuable insights for the diagnosis and treatment of such conditions.

Leptin is the oldest studied adipokine, and its mechanism of action in the regulation of energy metabolism remains a hot topic of current research. In this paper, we systematically review the progress of clinical and basic research on leptin and energy metabolism from 1994 to 2025. It is shown that leptin can regulate the energy metabolism homeostasis through autocrine, paracrine and neurohumoral pathways (e.g., hypothalamic-leptin-melanocortin axis). In addition, the effects of mainstream weight loss strategies such as dietary control, pharmacological interventions and exercise on leptin levels and their underlying mechanisms were investigated in this paper, with the aim of providing a theoretical basis for the clinical application of leptin in metabolic diseases (e.g., obesity, diabetes mellitus). Future studies need to further clarify the molecular mechanisms of leptin resistance and explore precise intervention strategies based on the leptin signaling pathway.

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.

Background: Cardiac fibroblasts (CFs) play a vital role in the physiological and pathological processes of the heart. Previous studies have demonstrated that high glucose stimulation induces the transformation of CFs into myofibroblasts, contributing to cardiac fibrogenesis. However, in vivo experiments have predominantly utilized adult animals, whereas most in vitro studies have focused on CFs derived from neonatal animals. The responses of CFs from different age groups to high glucose levels remain unclear. This study aimed to investigate transcriptional alterations in CFs at distinct developmental stages in response to high glucose exposure. Methods: CFs were isolated from neonatal (S1, 0–3 days), juvenile (S2, 3–4 weeks), adult (S3, 10–13 weeks), and aged (S4, 20 months) rats. CFs were exposed to normal (5.5 mM, NG) or high glucose (33 mM, HG). The cellular RNA was extracted for sequencing and analysis. Differentially expressed genes (DEGs) were validated by quantitative real-time PCR. Results: After NG treatment, fibrosis and inflammation-related gene expression in CFs (e.g., Col8a1, Col8a2, IL-6, Ccl2, Ccl20, Mmp2 and Mmp9) increased with age, while proliferation-related genes (MCM family, Sox10, Sox11) decreased. HG treatment most affected S3-CFs, showing 228 DEGs; it suppressed growth-related genes (Adra1d, Htr2b) and enhanced inflammatory genes (IL-6, Olr1). In S1-CFs, 197 inflammation-rich genes were upregulated under HG. S4-CFs displayed 166 DEGs, mostly metabolic downregulation (G6pc). S2-CFs had the fewest DEGs (112), focusing on cell metabolism. Conclusions: Fibrosis- and inflammation-associated gene expression in CFs showed an age-dependent stepwise elevation. CFs from distinct developmental stages responded differently to HG stimulation, with S3-CFs exhibiting the most pronounced response. These findings highlight the developmental characteristics of CFs and provide implications for the selection of appropriate CFs to investigate diabetes-associated cardiac fibrosis.

Leptin is the oldest studied adipokine, and its mechanism of action in the regulation of energy metabolism remains a hot topic of current research. In this paper, we systematically review the progress of clinical and basic research on leptin and energy metabolism from 1994 to 2026. It is shown that leptin can regulate the energy metabolism homeostasis through autocrine, paracrine and neurohumoral pathways (e.g., hypothalamic–leptin–melanocortin axis). In addition, the effects of mainstream weight loss strategies such as dietary control, pharmacological interventions and exercise on leptin levels, and their underlying mechanisms were investigated in this paper, with the aim of providing a theoretical basis for the clinical application of leptin in metabolic diseases (e.g., obesity, diabetes mellitus). Future studies need to further clarify the molecular mechanisms of leptin resistance and explore precise intervention strategies based on the leptin signaling pathway.