insulinproducing

Insulin-producing refers to cells or tissues capable of synthesizing insulin, most notably the beta cells of the pancreatic islets of Langerhans. In humans, these beta cells release insulin in response to rising blood glucose, coordinating systemic energy metabolism.

Biogenesis and secretion: Insulin is produced as preproinsulin in the endoplasmic reticulum, processed to proinsulin, and then cleaved to mature insulin and C-peptide in secretory granules. When glucose enters beta cells and is metabolized, the ATP/ADP ratio increases, leading to closure of KATP channels, membrane depolarization, calcium entry, and exocytosis of insulin-containing granules. Incretins and autonomic signals can modulate and amplify secretion.

Function and regulation: Insulin promotes glucose uptake in muscle and adipose tissue via GLUT4 and suppresses hepatic glucose production. It also influences lipid synthesis and protein metabolism. Production and secretion are regulated by transcription factors such as Pdx1, MafA, and NeuroD1, and can be affected by genetic, metabolic, and autoimmune factors.

Clinical relevance: Reduced or absent insulin production characterizes type 1 diabetes due to autoimmune beta-cell destruction; type 2 diabetes often involves beta-cell dysfunction with insulin resistance. Measuring C-peptide helps assess endogenous insulin production. Treatments include insulin replacement and lifestyle management, with research exploring immunotherapies and islet or stem cell–derived approaches to restore endogenous insulin production.

Research directions: Efforts are underway to generate insulin-producing cells from stem cells or reprogrammed tissues for transplantation. Key challenges include achieving full maturation, stable function, and protection from immune rejection. Advances continue to influence approaches to restore or preserve insulin production in diabetes.