In Vivo Screening for Secreted Proteins That Modulate Glucose Handling Identifies Interleukin-6 Family Members as Potent Hypoglycemic Agents

PLoS One

Peter C. Carolan¹  Justin P. Annes²  Chen Amy Chen³ 

[1] Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, United States of America;Department of Medicine, Stanford University Medical School, Stanford, California, United States of America;Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts, United States of America

关键词: Glucose tolerance;    Hepatocytes;    Luciferase;    Transfection;    Glucose metabolism;    Plasmid construction;    Hydrodynamics;    Homeostasis;   

DOI  :  10.1371/journal.pone.0044600

学科分类：医学（综合）

来源: Public Library of Science

【 摘 要 】

Diabetes is a disease of abnormal glucose homeostasis characterized by chronic hyperglycemia and a broad array of consequent organ damage. Because normal glucose homeostasis is maintained by a complex interaction between behavior (feeding and physical activity) and metabolic activity that is modulated by inter-organ signaling through secreted factors, disease modeling in vitro is necessarily limited. In contrast, in vivo studies allow complex metabolic phenotypes to be studied but present a barrier to high throughput studies. Here we present the development of a novel in vivo screening platform that addresses this primary limitation of in vivo experimentation. Our platform leverages the large secretory capacity of the liver and the hepatocyte transfection technique of hydrodynamic tail vein injection to achieve supraphysiologic blood levels of secreted proteins. To date, the utility of hydrodynamic transfection has been limited by the deleterious impact of the variable transfection efficiency inherent to this technique. We overcome this constraint by co-transfection of a secreted luciferase cDNA whose product can be easily monitored in the blood of a living animal and used as a surrogate marker for transfection efficiency and gene expression levels. To demonstrate the utility of our strategy, we screened 248 secreted proteins for the ability to enhance glucose tolerance. Surprisingly, interleukin-6 and several of its family members but not other well-recognized insulin sensitizing agents were identified as potent hypoglycemic factors. We propose this experimental system as a powerful and flexible in vivo screening platform for identifying genes that modulate complex behavioral and metabolic phenotypes.

【 授权许可】

CC BY