Physiological regulation of the pancreatic β-cell:: functional insights for understanding and therapy of diabetes

Knowledge about the sites and actions of the numerous physiological and pharmacological factors affecting insulin secretion and pancreatic beta-cell function has been derived from the use of bioengineered insulin-producing cell lines. Application of an innovative electrofusion approach has generated novel glucose-responsive insulin-secreting cells for pharmaceutical and experimental research, including popular BRIN-BD11 beta-cells. This review gives an overview of the establishment and core characteristics of clonal electrofusion-derived BRIN-BD11 beta-cells. As discussed, BRIN-BD11 cells have facilitated studies aimed at dissecting important pathways by which nutrients and other bioactive molecules regulate the complex mechanisms regulating insulin secretion, and highlight the future potential of novel and diverse bioengineering approaches to provide a cell-based insulin-replacement therapy for diabetes. Clonal BRIN-BD11 beta-cells have been instrumental in: (a) characterization of K-ATP channel-dependent and -independent actions of nutrients and established and emerging insulinotropic antidiabetic drugs, and the understanding of drug-induced beta-cell desensitization; (b) tracing novel metabolic and beta-cell secretory pathways, including use of state-of-the-art NMR approaches to provide new insights into the relationships between glucose and amino acid handling and insulin secretion; and (c) determination of the chronic detrimental actions of nutrients and the diabetic environment on pancreatic beta-cells, including the recent discovery that homocysteine, a risk factor for metabolic syndrome, may play a role in the progressive demise of insulin secretion and pancreatic beta-cell function in diabetes. Collectively, the studies discussed in this review highlight the importance of innovative experimental beta-cell physiology in the discovery and characterization of new and improved drugs and therapeutic strategies to help tackle the emerging diabetes epidemic.