Changes in immunofluorescence staining during islet regeneration in a cystic fibrosis-related diabetes (CFRD) ferret model

Islets. 2024 Dec 31;16(1):2436696. doi: 10.1080/19382014.2024.2436696. Epub 2024 Dec 6.

Abstract

Background: Knockout (KO) ferrets with the cystic fibrosis transmembrane conductance regulator (CFTR) exhibit distinct phases of dysglycemia and pancreatic remodeling prior to cystic fibrosis-related diabetes (CFRD) development. Following normoglycemia during the first month of life (Phase l), hyperglycemia occurs during the subsequent 2 months (Phase Il) with decreased islet mass, followed by a period of near normoglycemia (Phase Ill) in which the islets regenerate. We aimed to characterize islet hormone expression patterns across these Phases.

Methods: Immunofluorescence staining per islet area was performed to characterize islet hormone expression patterns in age matched CFTR KO and wild type (WT) ferrets, focusing on the first three phases.

Results: In Phase I, insulin staining intensity was higher in CF (p < 0.01) than WT but decreased in Phase III (p < 0.0001). Glucagon was lower in CF during Phases I and increased in Phase III, while proinsulin decreased (p < 0.0001) Phases II and III. CF sections showed lower proinsulin-to-insulin ratio in Phase I (p < 0.01) and in Phase III (p < 0.05) compared to WT. Conversely, glucagon-to-insulin ratio was lower in CF in Phase I (p < 0.0001) but increased in Phase III (p < 0.0001). Mender's coefficient overlap showed higher overlap of insulin over proinsulin in CF sections in Phase II (p < 0.001) and Phase III (p < 0.0001) compared to WT. Mender's coefficient rate was higher in CF sections during Phase II (p < 0.001).

Conclusion: CF ferret islets revealed significant immunofluorescent staining changes compared to WT during various phases of disease, providing insights into CRFD pathophysiology.

Keywords: Alpha and beta cells; Immunostaining; cystic fibrosis-related diabetes; ferret model; glucagon staining; glucagon-to-insulin ratio; glycemic phases; insulin staining; proinsulin staining; proinsulin-to-insulin colocalization; proinsulin-to-insulin ratio.

MeSH terms

  • Animals
  • Cystic Fibrosis Transmembrane Conductance Regulator* / genetics
  • Cystic Fibrosis Transmembrane Conductance Regulator* / metabolism
  • Cystic Fibrosis* / complications
  • Cystic Fibrosis* / metabolism
  • Cystic Fibrosis* / pathology
  • Diabetes Mellitus / metabolism
  • Disease Models, Animal*
  • Female
  • Ferrets*
  • Fluorescent Antibody Technique
  • Glucagon / metabolism
  • Insulin / metabolism
  • Islets of Langerhans* / metabolism
  • Islets of Langerhans* / pathology
  • Male
  • Proinsulin / metabolism
  • Regeneration*

Substances

  • Cystic Fibrosis Transmembrane Conductance Regulator
  • Glucagon
  • Insulin
  • Proinsulin