Deciphering the Role of the SREBF1 Gene in the Transcriptional Regulation of Porcine Adipogenesis Using CRISPR/Cas9 Editing

Sterol regulatory element-binding protein 1 (SREBP1) is an important transcription factor that controls lipid metabolism and adipogenesis. Two isoforms, SREBP1a and SREBP1c, are generated by alternative splicing of the first exon of the <i>SREBF1</i> gene. The porcine <i>SREBF1</i> gene has mainly been studied for its role in lipid metabolism in adipose tissues, but little is known about its involvement, and the role of its two isoforms, in adipogenesis. The aim of the present study was to introduce a deletion in the 5'-regulatory region of the <i>SREBF1c</i> gene, considered crucial for adipogenesis, using the Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated protein 9 (CRISPR/Cas9) method. This approach allows for the evaluation of how inhibiting <i>SREBF1c</i> transcription affects the expression of other genes essential for adipocyte differentiation, particularly <i>PPARG</i>, <i>CEBPA</i>, <i>CEBPB</i>, <i>CEBPD</i>, <i>GATA2</i>, and <i>FABP4</i>. It was observed that disrupting the <i>SREBF1c</i> isoform had no effect on the <i>GATA2</i> gene but did result in a decrease in the expression of the <i>CEBPA</i> and <i>CEBPD</i> genes, an increase in the expression of <i>CEBPB</i>, and an inhibition in the expression of the <i>PPARG</i> and <i>FABP4</i> genes. These changes in gene expression blocked adipogenesis, as could be seen by the failure of lipid droplets to accumulate. Our results provide evidence highlighting the pivotal role of the <i>SREBP1c</i> isoform in the regulation of porcine adipogenesis.