K Oishi1, N Ohkura, M Wakabayashi, H Shirai, K Sato, J Matsuda, G Atsumi, N Ishida. 1. Clock Cell Biology Research Group, Institute for Biological Resources and Functions, National Institute of Advanced Industrial Science and Technology, Higashi, Tsukuba, Ibaraki, Japan.
Abstract
BACKGROUND: An increased level of obesity-induced plasma plasminogen activator inhibitor-1 (PAI-1) is considered a risk factor for cardiovascular disease. AIM: The present study investigates whether the circadian clock component CLOCK is involved in obesity-induced PAI-1 elevation. METHODS: We examined plasma PAI-1 and mRNA expression levels in tissues from leptin-deficient obese and diabetic ob/ob mice lacking functional CLOCK protein. RESULTS: Our results demonstrated that plasma PAI-1 levels were augmented in a circadian manner in accordance with the mRNA expression levels in ob/ob mice. Surprisingly, a Clock mutation normalized the plasma PAI-1 concentrations in accordance with the mRNA levels in the heart, lung and liver of ob/ob mice, but significantly increased PAI-1 mRNA levels in adipose tissue by inducing adipocyte hypertrophy in ob/ob mice. The Clock mutation also normalized tissue PAI-1 antigen levels in the liver but not in the adipose tissue of ob/ob mice. CONCLUSION: These observations suggest that CLOCK is involved in obesity-induced disordered fibrinolysis by regulating PAI-1 gene expression in a tissue-dependent manner. Furthermore, it appears that obesity-induced PAI-1 production in adipose tissue is not closely related to systemic PAI-1 increases in vivo.
BACKGROUND: An increased level of obesity-induced plasma plasminogen activator inhibitor-1 (PAI-1) is considered a risk factor for cardiovascular disease. AIM: The present study investigates whether the circadian clock component CLOCK is involved in obesity-induced PAI-1 elevation. METHODS: We examined plasma PAI-1 and mRNA expression levels in tissues from leptin-deficient obese and diabetic ob/ob mice lacking functional CLOCK protein. RESULTS: Our results demonstrated that plasma PAI-1 levels were augmented in a circadian manner in accordance with the mRNA expression levels in ob/ob mice. Surprisingly, a Clock mutation normalized the plasma PAI-1 concentrations in accordance with the mRNA levels in the heart, lung and liver of ob/ob mice, but significantly increased PAI-1 mRNA levels in adipose tissue by inducing adipocyte hypertrophy in ob/ob mice. The Clock mutation also normalized tissue PAI-1 antigen levels in the liver but not in the adipose tissue of ob/ob mice. CONCLUSION: These observations suggest that CLOCK is involved in obesity-induced disordered fibrinolysis by regulating PAI-1 gene expression in a tissue-dependent manner. Furthermore, it appears that obesity-induced PAI-1 production in adipose tissue is not closely related to systemic PAI-1 increases in vivo.
Authors: Prachi Singh; Timothy E Peterson; Kara R Barber; Fatima Sert Kuniyoshi; Andrus Jensen; Michal Hoffmann; Abu S M Shamsuzzaman; Virend K Somers Journal: Biochem Biophys Res Commun Date: 2010-01-05 Impact factor: 3.575
Authors: Audrey C A Cleuren; Vicky T Blankevoort; Janna A van Diepen; Daniël Verhoef; Peter J Voshol; Pieter H Reitsma; Bart J M van Vlijmen Journal: PLoS One Date: 2015-07-15 Impact factor: 3.240