C Saini1,2, V Petrenko1,2, P Pulimeno1,3, L Giovannoni1, T Berney4, M Hebrok3, C Howald2,5,6, E T Dermitzakis2,5,6, C Dibner1,2. 1. Endocrinology, Diabetes, Hypertension and Nutrition, Diabetes Centre, Faculty of Medicine, University of Geneva, Geneva, Switzerland. 2. Institute of Genetics and Genomics in Geneva (iGE3), Geneva, Switzerland. 3. Diabetes Center, UCSF, San Francisco, CA, USA. 4. Department of Surgery, Cell Isolation and Transplantation Centre, University Hospital of Geneva, Geneva, Switzerland. 5. Department of Genetic Medicine and Development, University of Geneva Medical School, Geneva, Switzerland. 6. Swiss Institute of Bioinformatics, Geneva, Switzerland.
Abstract
AIM: To determine the impact of a functional human islet clock on insulin secretion and gene transcription. METHODS: Efficient circadian clock disruption was achieved in human pancreatic islet cells by small interfering RNA-mediated knockdown of CLOCK. Human islet secretory function was assessed in the presence or absence of a functional circadian clock by stimulated insulin secretion assays, and by continuous around-the-clock monitoring of basal insulin secretion. Large-scale transcription analysis was accomplished by RNA sequencing, followed by quantitative RT-PCR analysis of selected targets. RESULTS: Circadian clock disruption resulted in a significant decrease in both acute and chronic glucose-stimulated insulin secretion. Moreover, basal insulin secretion by human islet cells synchronized in vitro exhibited a circadian pattern, which was perturbed upon clock disruption. RNA sequencing analysis suggested alterations in 352 transcript levels upon circadian clock disruption. Among them, key regulators of the insulin secretion pathway (GNAQ, ATP1A1, ATP5G2, KCNJ11) and transcripts required for granule maturation and release (VAMP3, STX6, SLC30A8) were affected. CONCLUSIONS: Using our newly developed experimental approach for efficient clock disruption in human pancreatic islet cells, we show for the first time that a functional β-cell clock is required for proper basal and stimulated insulin secretion. Moreover, clock disruption has a profound impact on the human islet transcriptome, in particular, on the genes involved in insulin secretion.
AIM: To determine the impact of a functional human islet clock on insulin secretion and gene transcription. METHODS: Efficient circadian clock disruption was achieved in humanpancreatic islet cells by small interfering RNA-mediated knockdown of CLOCK. Human islet secretory function was assessed in the presence or absence of a functional circadian clock by stimulated insulin secretion assays, and by continuous around-the-clock monitoring of basal insulin secretion. Large-scale transcription analysis was accomplished by RNA sequencing, followed by quantitative RT-PCR analysis of selected targets. RESULTS: Circadian clock disruption resulted in a significant decrease in both acute and chronic glucose-stimulated insulin secretion. Moreover, basal insulin secretion by human islet cells synchronized in vitro exhibited a circadian pattern, which was perturbed upon clock disruption. RNA sequencing analysis suggested alterations in 352 transcript levels upon circadian clock disruption. Among them, key regulators of the insulin secretion pathway (GNAQ, ATP1A1, ATP5G2, KCNJ11) and transcripts required for granule maturation and release (VAMP3, STX6, SLC30A8) were affected. CONCLUSIONS: Using our newly developed experimental approach for efficient clock disruption in humanpancreatic islet cells, we show for the first time that a functional β-cell clock is required for proper basal and stimulated insulin secretion. Moreover, clock disruption has a profound impact on the human islet transcriptome, in particular, on the genes involved in insulin secretion.
Authors: Ursula Loizides-Mangold; Laurent Perrin; Bart Vandereycken; James A Betts; Jean-Philippe Walhin; Iain Templeman; Stéphanie Chanon; Benjamin D Weger; Christine Durand; Maud Robert; Jonathan Paz Montoya; Marc Moniatte; Leonidas G Karagounis; Jonathan D Johnston; Frédéric Gachon; Etienne Lefai; Howard Riezman; Charna Dibner Journal: Proc Natl Acad Sci U S A Date: 2017-09-25 Impact factor: 11.205
Authors: Yan Shi; Li Liu; Eva S Schernhammer; Reiko Nishihara; Xuehong Zhang; Tsuyoshi Hamada; Jonathan A Nowak; Marios Giannakis; Yanan Ma; Mingyang Song; Daniel Nevo; Keisuke Kosumi; Mancang Gu; Sun A Kim; Teppei Morikawa; Kana Wu; Jing Sui; Kyriaki Papantoniou; Molin Wang; Andrew T Chan; Charles S Fuchs; Jeffrey A Meyerhardt; Edward Giovannucci; Shuji Ogino Journal: Cancer Epidemiol Biomarkers Prev Date: 2019-10-30 Impact factor: 4.254