Counter-regulation Of Bifunctional Adipocyte Regulators Promotes Adipocyte Beiging

PURPOSE: Obesity, a global epidemic affecting over 890 million individuals, is characterized by excessive white adipose tissue (WAT) accumulation and impaired energy expenditure. Beiging of WAT, via the induction of thermogenic brown-like adipocytes, presents a transformative approach to reverse metabolic dysfunction. Specific transcriptional regulators critical for maintaining white adipocyte identity repress thermogenic gene networks. Prior studies have demonstrated that silencing individual transcriptional repressors can derepress thermogenic genes and initiate beiging in white adipocytes. This study investigates targeted silencing of these regulators to unlock adipocyte plasticity and promote metabolic reprogramming. METHODS: We define these targets as Bifunctional Adipogenic Regulators (BARs), based on their dual role in adipocyte differentiation and maintenance of mature white fat identity. They were silenced in differentiated 3T3-L1 adipocytes using lipid nanoparticle (LNP)-formulated siRNA. Molecular analyses included qPCR to assess gene expression changes. In vivo, AAV8-shRNA was used to target these regulators in murine inguinal adipose tissue. RESULTS: Double-dose siRNA treatment achieved up to 97% knockdown of the target genes, while single-dose protocols yielded approximately 70% reduction. This intervention led to a 2-3-fold increase in uncoupling protein 1 (UCP1) expression, which further increased to 4-6 fold with mRNA co-administration. Robust transfection efficiency was confirmed by strong upregulation of key thermogenic transcripts. Dual knockdown of BARs resulted in robust repression of white adipocyte markers and dramatic activation of the thermogenic program, including a 77.8-fold increase in UCP1 expression. In vivo, AAV8-shRNA delivery successfully targeted adipose tissue in mice. CONCLUSION: These findings highlight transcriptional repression as a fundamental barrier to adipocyte beiging and identify these factors as promising targets for RNA-based obesity therapies. Combinatorial strategies involving targeted knockdown and activation of thermogenic pathways enhance reprogramming potential. This work provides a foundation for the development of precision metabolic reprogramming strategies for obesity. *Source: https://ps-rc.org/meeting/Program/2026/55.cgi*