Dynamic Histone Modification Patterns in Key Transcription Factor Genes During Porcine Adipogenesis

Adipogenesis is governed by a complex interplay between transcriptional regulation and epigenetic remodeling. While many transcriptional pathways have been well characterized, less is known about how chromatin-level regulation shapes the timing of gene expression, particularly in large animal models such as pigs. In this study, we investigated histone modification patterns associated with four key adipogenic transcription factor genes-PPARG, GATA2, CEBPA, and CEBPB-in porcine mesenchymal stem cells (MSCs) undergoing adipogenic differentiation.

Using RT-qPCR and ChIP-qPCR, we profiled gene transcription levels and epigenetic marks, including promoter- and exon-specific enrichment of the activating histone marks H3K9ac and H4K8ac, as well as the repressive mark H4K20me3, across six time points (day 0, 2, 4, 6, 8, and 10).

Although PPARG and GATA2 are located in close proximity on porcine chromosome 13, they exhibited distinct histone modification profiles. PPARG showed progressive promoter acetylation (H4K8ac) accompanied by transcriptional activation, whereas GATA2 displayed decreased exon acetylation (H3K9ac) associated with declining expression. In contrast, the H4K20me3 profile was similar for both genes, suggesting no direct association with their transcriptional activity. Interestingly, CEBPA (chromosome 6) and CEBPB (chromosome 17) exhibited temporally distinct histone modification patterns consistent with their roles in intermediate and early stages of adipogenic differentiation, respectively. Increased enrichment of the H3K9ac mark preceded the rise in transcript levels of the analyzed genes. Promoter regions showed higher enrichment of H4K8ac compared with exonic regions. A higher level of H4K20me3 was also observed for CEBPA and CEBPB than for PPARG and GATA2, which appeared to be more related to chromosomal localization than to direct transcriptional regulation.

Together, these results reveal complex interactions between transcriptional dynamics and selected histone modifications that depend on both the gene analyzed and the stage of adipocyte differentiation. This study provides new insights into the epigenetic regulation of porcine adipogenesis and highlights chromatin context as an additional layer influencing transcriptional control.