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

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

CONCLUSION

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