YY1 deficiency in β-cells leads to mitochondrial dysfunction and diabetes in mice

The transcription factor YY1 is an important regulator for metabolic homeostasis. Activating mutations in YY1 lead to tumorigenesis of pancreatic β-cells, however, the physiological functions of YY1 in β-cells are still unknown. Here, we investigated the effects of YY1 ablation on insulin secretion and glucose metabolism.

We established two models of β-cell-specific YY1 knockout mice. The glucose metabolic phenotypes, β-cell mass and β-cell functions were analyzed in the mouse models. Transmission electron microscopy was used to detect the ultrastructure of β-cells. The flow cytometry analysis, measurement of OCR and ROS were performed to investigate the mitochondrial function. Histological analysis, quantitative PCR and ChIP were performed to analyze the target genes of YY1 in β-cells.

Our results showed that loss of YY1 resulted in reduction of insulin production, β-cell mass and glucose tolerance in mice. Ablation of YY1 led to defective ATP production and mitochondrial ROS accumulation in pancreatic β-cells. The inactivation of YY1 impaired the activity of mitochondrial oxidative phosphorylation, induced mitochondrial dysfunction and diabetes in mouse models.

Our findings demonstrate that the transcriptional activity of YY1 is essential for the maintenance of mitochondrial functions and insulin secretion in β-cells.