Establishment of a long-term stable β-cell line and its application to analyze the effect of Gcg expression on insulin secretion

A pancreatic beta-cell line MIN6 was previously established in our lab from an insulinoma developed in an IT6 transgenic mouse expressing the SV40 T antigen in beta-cells. This cell line has been widely used for in vitro analysis of beta-cell function, but tends to lose the mature beta-cell features, including glucose-stimulated insulin secretion (GSIS), in long-term culture. The aim of this study was to develop a stable beta-cell line that retains the characteristics of mature beta-cells. Considering that mice derived from a cross between C3H and C57BL/6 strains are known to exhibit higher insulin secretory capacity than C57BL/6 mice, an IT6 male mouse of this hybrid background was used to isolate insulinomas, which were independently cultured. After 7 months of continuous culturing, we obtained the MIN6-CB4 beta-cell line, which stably maintains its GSIS. It has been noted that beta-cell lines express the glucagon (Gcg) gene at certain levels. MIN6-CB4 cells were utilized to assess the effects of differential Gcg expression on beta-cell function. Our data show the functional importance of Gcg expression and resulting basal activation of the GLP-1 receptor in beta-cells. MIN6-CB4 cells can serve as an invaluable tool for studying the regulatory mechanisms of insulin secretion, such as the GLP-1/cAMP signaling, in beta-cells.

Automated summary

A stable beta-cell line MIN6-CB4 was developed from a hybrid mouse model, which maintains mature beta-cell characteristics and is valuable for studying the effects of Gcg expression on beta-cell function. The study highlights the functional importance of Gcg expression and basal activation of GLP-1 receptor in beta-cells, providing an invaluable tool for investigating insulin secretion regulatory mechanisms.