Rat serum improves rat pseudoislet formation and insulin gene expression

Area of Science:

• * Regenerative Medicine
• * Endocrinology
• * Transplantation Immunology

Background:

• * Pseudoislets, derived from rat islet cells in culture, mimic native islets and offer potential for transplantation without immunosuppression.
• * Current limitations in pseudoislet use include low yield and poor reaggregation, hindering their clinical application.
• * Culture conditions critically influence pseudoislet reaggregation and functionality.

Purpose of the Study:

• * To investigate the impact of varying concentrations of Fetal Bovine Serum (FBS) and Rat Serum (RS) on pseudoislet reaggregation and insulin gene expression.
• * To determine the optimal serum supplement for enhancing pseudoislet yield and function for transplantation purposes.

Main Methods:

• * Rat islets were isolated using histopaque gradient centrifugation and dissociated into single cells.
• * Cells were cultured in RPMI 1640 with 5.6 mM glucose and 2%, 5%, or 10% FBS or RS for seven days.
• * Pseudoislets were quantified, and their insulin secretion and gene expression were analyzed using RT-PCR.

Main Results:

• * Rat serum (RS) supplementation led to a significant increase in the number and diameter of pseudoislet aggregates compared to FBS.
• * Pseudoislets cultured with RS exhibited a tenfold increase in insulin gene expression relative to those cultured with FBS.
• * RS improved both the total reaggregate volume and insulin gene expression.

Conclusions:

• * Rat serum is superior to Fetal Bovine Serum for enhancing pseudoislet reaggregation and insulin gene expression in vitro.
• * Supplementation with Rat Serum improves key parameters for pseudoislet production, making it a more suitable option for transplantation research.
• * These findings advance the potential of using pseudoislets as a viable source for islet transplantation.