Screening for insulin-independent pathways that modulate glucose homeostasis identifies androgen receptor antagonists

Abstract

Pathways modulating glucose homeostasis independently of insulin would open new avenues to combat insulin resistance and diabetes. Here, we report the establishment, characterization, and use of a vertebrate ‘insulin-free’ model to identify insulin-independent modulators of glucose metabolism. insulin knockout zebrafish recapitulate core characteristics of diabetes and survive only up to larval stages. Utilizing a highly efficient endoderm transplant technique, we generated viable chimeric adults that provide the large numbers of insulin mutant larvae required for our screening platform. Using glucose as a disease-relevant readout, we screened 2233 molecules and identified three that consistently reduced glucose levels in insulin mutants. Most significantly, we uncovered an insulin-independent beneficial role for androgen receptor antagonism in hyperglycemia, mostly by reducing fasting glucose levels. Our study proposes therapeutic roles for androgen signaling in diabetes and, more broadly, offers a novel in vivo model for rapid screening and decoupling of insulin-dependent and -independent mechanisms.

Intestinal Cetobacterium and acetate modify glucose homeostasis via parasympathetic activation in zebrafish

“…In humans and mammals, insulin is the only pancreatic cell hormone known to directly regulate blood glucose. 46–49 Mullapudi et al 50 has confirmed that insulin in zebrafish is also as important as in humans and mammals. Prior studies have demonstrated that the development of zebrafish cell is highly conserved with that of mammals.…”

A whole organism small molecule screen identifies novel regulators of pancreatic endocrine development

“…Embryos were staged by hpf at 28.5°C (Kimmel et al, 1995). The following lines were used: Tg(fabp10a: EGFP) as3 (Her, Yeh, and Wu, 2003), Tg(ins:Kaede) jh6 (Pisharath et al, 2007), Tg(ins:dsRed) m1018 (Shin et al, 2008), Tg(ins:Hsa.HIST1H2BJ-GFP;ins:DsRed) s960 (Ninov et al, 2013) abbreviated Tg(ins:H2B-GFP;ins: DsRed), Tg( pck1:Luciferase) s952 (Gut et al, 2013), Tg BAC (neuroD: EGFP) nl1 (Obholzer et al, 2008), pdx1 sa280 (Kimmel et al, 2015), insulin bns102 (Mullapudi et al, 2018), Tg(insulin:loxP:mCherrySTOP: loxP:H2B-GFP; cryaa:Cerulean) s934 (Hesselson et al, 2011), Tg(sox17: GFP) s870 (Sakaguchi et al, 2006), Tg(Tp1bglob:H2BmCherry) S939 (Ninov et al, 2012), Tg(ubb:loxP:CFP:loxP:H2B-mCherry) jh63 (Wang et al, 2015), Tg BAC (arxa:Cre) bns250 (this study), Tg BAC ( pdx1:EGFP) bns13 (this study), Tg BAC ( pdx1:luciferase2) bns17 (this study) and Tg(ins:loxP-Eco.NfsB-mCherry-loxP-luciferase) bns152 abbreviated as Tg(ins:mCherry) (this study).…”

Molecular and Cellular Mechanisms of Vascular Development in Zebrafish

“…The development of new imaging technologies, such as light sheet microscopy, new fluorophores and biosensors, will allow even more detailed images to be acquired over longer periods of time without bleaching or photo toxicity. Technologies such as small molecule screens [ 151 , 152 , 153 ] and protein-protein interaction assays (e.g., BioID) [ 154 , 155 ] are extending the toolbox for using the zebrafish model. The emergence of single cell sequencing technologies within the last years enabled the dissection of the developmental trajectories of cells and their heterogeneity within one cell lineage [ 156 ].…”