Dr. Vincenzo Cirulli co-authors a new study with the research team of Dr. Domenico Accili at Columbia University (New York, NY). The study, published in Molecular Metabolism, identifies the Cytochrome b5 reductase (Cyb5r3) as a critical regulator of FoxO1-dependent mitochondrial function that protects pancreatic β-cells from nutritional and oxidative stress. Accordingly, mice with altered Cyb5r3 expression revealed impaired insulin secretion, glucose intolerance and diet-induced hyperglycemia. Ultrastructural analysis of pancreatic β-cells by transmission electron microscopy revealed that these functional abnormalities may be explained by a significant loss of β-cell identity that include altered mitochondrial integrity, defective biogenesis of insulin secretory vesicles, and significant ER (endoplasmic reticulum) stress, all trademarks of type 2 diabetes.
The authors wish to dedicate this work to the memory of Dr. Lelio Orci, a pioneer of the microanatomy and function of the endocrine pancreas, as well as of the molecular mechanisms that govern β-cell secretory functions (https://link.springer.com/article/10.1007/s00125-019-05072-9/).