Hexose recognition by insulin-secreting BRIN-BD11 cells

Area of Science:

• Cell Biology
• Endocrinology
• Metabolic Research

Background:

• Pancreatic beta cells are crucial for regulating blood glucose through insulin secretion.
• Understanding nutrient sensing and insulin release mechanisms is vital for diabetes research.
• Existing cell models often lack the full responsiveness of native beta cells.

Purpose of the Study:

• To develop and characterize a novel clonal pancreatic beta cell line, BRIN-BD11.
• To assess the glucose transport and insulin secretion capabilities of BRIN-BD11 cells.
• To compare BRIN-BD11 cell function with the established RINm5F cell line.

Main Methods:

• Electrofusion of rat islet B-cells with RINm5F cells to create BRIN-BD11 cells.
• Western blotting to analyze glucose transporter protein expression (GLUT-2).
• Measurement of D-glucose and other hexose uptake and insulin secretion in response to varying nutrient concentrations.

Main Results:

• BRIN-BD11 cells express high levels of GLUT-2, exhibiting significantly greater D-glucose uptake than RINm5F cells.
• BRIN-BD11 cells possess a high glucokinase:hexokinase ratio, showing robust, dose-dependent insulin secretion with D-glucose and D-mannose.
• RINm5F cells have a lower glucokinase:hexokinase ratio and are largely unresponsive to D-glucose and D-mannose, responding only to D-galactose.

Conclusions:

• BRIN-BD11 cells demonstrate superior glucose transport and nutrient-stimulated insulin secretion compared to RINm5F cells.
• The high GLUT-2 expression and glucokinase:hexokinase ratio contribute to BRIN-BD11's enhanced responsiveness.
• BRIN-BD11 cells represent a valuable model for investigating nutrient-induced insulin secretion.