Insulin Secretion and the β-Cell 102 Years After the Discovery of the Hormone

Purpose of Review The discovery of insulin was a true landmark in biomedical research and provided a framework for the understanding of many pivotal mechanisms in cell biology throughout the twentieth century, as insulin for instance was the first major protein to have its amino acid sequence and 3D structure resolved. The elucidation of the processes that regulate and mediate insulin secretion has also contributed with crucial mechanistic insights on the pathways that lead to both type 1 and type 2 diabetes mellitus. More than 100 years after the discovery of this hormone, an overview of the present knowledge on insulin output from β-cells should be timely to the general researcher interested in the mechanisms that couple glucose stimulation to insulin secretion. Recent Findings Although the mechanisms underlying insulin secretion have been exhaustively studied and understood in animal models, the last decades have shown that important differences can be identified compared to human β-cells. Additionally, despite both reactive oxygen species as well as the immune system have been initially implicated in β-cell dysfunction and the progression to diabetes, increasing evidence indicates that both can also have physiological effects for proper insulin secretion. Summary Given this background, this brief review focused on discussing various means by which glucose elicits insulin secretion by the β-cells, particularly on the modulatory role of redox balance and inflammation on β-cell function and/or demise, also drawing attention to the specific mechanisms connecting glucose stimulation to insulin secretion in humans.