Quantitative assessment by digital image analysis for Beta2/NeurD1 to evaluate the pancreatic islets morphogenesis & subpopulation in late pregnancy of mice

Abstract

In pregnancy Peripheral, insulin resistance generating environment requires higher production of insulin, so the islets of langerhans undergo major structural & functional changes.

     The present study was designed to analyse and compare the immunohistochemical staining of Beta2/NeuroD1 transcription factor in islets of langerhans (Beta-cells mainly) and capillary vessels of islets in non-pregnant & pregnant state, in order to contribute a knowledge about a possible alteration throughout the life span directed to better understanding of the pancreatic metabolism, & findings can be applied to cell-based therapies to treat diabetics.

     The pancreas specimens taken from sixty mature female mice, thirty for each group. They divided in to Group (A): Served as control (non-pregnant), Group (B): Pregnant group (at day 17^th, 18^th, 19^th of pregnancy). Tissues processed for paraffin block, sections stained with: Haematoxylin and eosin stain (to demonstrate the general histological and morphological changes that took place). Immunohistochemical stain (to compare the positivity of immunostaining of Beta2/NeuroD1 in beta cells & capillary vessels of islets in non-pregnant & pregnant groups). Two digital image analysing softwares used in this study: Image Scope program (for quantification of immunostaining of Beta2/NeuroD1factor in beta cells & capillary vessel, nucleus & cytoplasm at the same time). ImageJ program (for quantification of immunostaining of Beta2 factor in beta cells & capillary vessel, nucleus & cytoplasm in a separate manner).

        Result of the histological examination of the present study demonstrated that the increment in number and size of islets of langerhans were the main features observed during pregnancy. Also showed the number and size of blood vessels increase inside islets & around it, in pregnant groups. Result of the immunohistochemical examination of this study showed increase of immunostaining positivity of Beta2/NeuroD1 factor in beta cells & capillary vessels of islets of langerhans in pregnant group than non-pregnant.

        This study conclude that the Beta2/NeuroD1 factor is affected by insulin-resistant state of pregnancy, this open the question about the role of this factor in the origin of newly formed islets of langerhans ( mainly beta cells) in pregnant group.