Genome-edited zebrafish model of ABCC8 loss-of-function disease

Zebrafish as a preclinical model for diabetes mellitus and its complications: From monogenic to gestational diabetes and beyond

With diabetes currently affecting 537 million people globally, innovative research approaches are urgently required. Zebrafish (Danio rerio) has emerged as a pivotal model organism in diabetes research, particularly valuable for developmental biology studies and preclinical therapeutic validation. Its rapid life cycle, optical transparency, and genetic tractability collectively enable efficient longitudinal observation of pathological progression and pharmacological responses. Utilizing zebrafish models, researchers have elucidated fundamental mechanisms governing islet development, β-cell dysfunction, and metabolic dysregulation. These experimental systems have significantly advanced our understanding of various diabetes subtypes, including type 1, type 2, gestational, and monogenic forms, while also facilitating mechanistic studies of diabetic complications such as retinopathy and nephropathy. Recent model refinements, particularly in simulating monogenic disorders and pregnancy-associated metabolic changes, promise to deepen our comprehension of disease pathophysiology and therapeutic interventions. Nevertheless, a persistent limitation lies in their incomplete recapitulation of human-specific physiological complexity and multi-organ metabolic interactions, factors that may influence translational applicability. Despite these constraints, zebrafish-based research continues to provide an indispensable platform for diabetes investigation, holding significant promise for alleviating the escalating global burden of this metabolic disorder.

Characterization of the zebrafish as a model of ATP-sensitive potassium channel hyperinsulinism

INTRODUCTION

Congenital hyperinsulinism (HI) is the leading cause of persistent hypoglycemia in infants. Current models to study the most common and severe form of HI resulting from inactivating mutations in the ATP-sensitive potassium channel (KATP) are limited to primary islets from patients and the Sur1 -/- mouse model. Zebrafish exhibit potential as a novel KATPHI model since they express canonical insulin secretion pathway genes and those with identified causative HI mutations. Moreover, zebrafish larvae transparency provides a unique opportunity for in vivo visualization of pancreatic islets.

RESEARCH DESIGN AND METHODS

We evaluated zebrafish as a model for KATPHI using a genetically encoded Ca2+ sensor (ins:gCaMP6s) expressed under control of the insulin promoter in beta cells of an abcc8 -/- zebrafish line.

RESULTS

We observed significantly higher islet cytosolic Ca2+ in vivo in abcc8 -/- compared with abcc8 +/+ zebrafish larvae. Additionally, abcc8 -/- larval zebrafish had significantly lower whole body glucose and higher whole body insulin levels compared with abcc8 +/+ controls. However, adult abcc8 -/- zebrafish do not show differences in plasma glucose, plasma insulin, or glucose tolerance when compared with abcc8 +/+ zebrafish.

CONCLUSIONS

Our results identify that zebrafish larvae, but not adult fish, are a demonstrable novel model for advancement of HI research.