GobletZellen

Gobletzellen, or goblet cells, are mucus-secreting epithelial cells found in the mucous membranes of the respiratory and gastrointestinal tracts, as well as on other mucosal surfaces such as the conjunctiva. They are unicellular glands embedded among other epithelial cells and are typically tall columnar in shape. Their apical cytoplasm is distended with mucin-containing granules, giving them a characteristic goblet-like appearance.

Function and secretion: Goblet cells synthesize and secrete gel-forming mucins, the major component of mucus. In the intestine, the predominant mucin is MUC2; in the airways, MUC5AC and MUC5B are common. The produced mucins hydrate and swell to form a protective gel that coats the epithelial surface, traps microbes and particulates, and supports barrier function. Mucin granules are produced in the Golgi apparatus and released by regulated exocytosis in response to stimuli such as acetylcholine, inflammatory mediators, or microbial products. The resulting mucus layer also facilitates clearance of particles and pathogens via ciliary motion in the respiratory tract or peristaltic movement in the gut.

Distribution and regulation: Goblet cells are interspersed among other epithelial cells throughout the small and large intestine and the airways, with their density generally increasing along the gut from the small intestine to the colon and in the lower airways. Differentiation of goblet cells from intestinal stem cells involves transcriptional pathways that include Math1/Atoh1 and Notch signaling, which balances secretory versus absorptive cell fates.

Clinical relevance: Alterations in goblet cell number and mucus production occur in various diseases. Goblet cell hyperplasia and mucus overproduction are observed in allergic asthma, chronic rhinosinusitis, and inflammatory bowel diseases; mucus viscosity can be markedly increased in cystic fibrosis, affecting clearance and barrier function.