1. Volume 11, Issue 3, Pages 175-176 (March 2010)
The FOX(O1) Blasts Off 
Deborah Veis Novack 
Cell Metabolism 
Volume 11, Issue 3, Pages (March 2010)
DOI: /j.cmet
Copyright © 2010 Elsevier Inc. Terms and Conditions

2. Figure 1 FOXO1 Modulates Insulin Responses via Osteocalcin
The FOXO1 transcription factor upregulates OST-PTP and downregulates osteocalcin in the osteoblast. Insulin suppresses FOXO1, enhancing osteocalcin synthesis and decreasing OST-PTP. OST-PTP increases γ-carboxylation of osteocalcin, which inactivates this hormone. The net effect of insulin is to increase active osteocalcin, which then acts on β cells in the pancreas and adipocytes (blue arrows). Osteocalcin stimulates proliferation of β cells, and their insulin production and sensitivity. Insulin then acts on hepatocytes, myocytes, and adipocytes, promoting glucose homeostasis. It also inhibits FOXO1 in osteoblasts, creating an insulin/osteocalcin positive feedback loop. Osteocalcin also increases secretion of adiponectin by adipocytes, which enhances peripheral insulin sensitivity, further promoting efficient glucose metabolism.
Cell Metabolism  , DOI: ( /j.cmet )
Copyright © 2010 Elsevier Inc. Terms and Conditions