title: Expression of calnexin reflects paneth cell differentiation and function.
abstract: It has been suggested that the behavior and function of Paneth cells in metaplasia are different from those found in normal intestinal mucosa. In this study, we investigated whether calnexin, a protein involved in secretory pathways, might be associated with differentiation and function of Paneth cells in normal small intestine, in complete intestinal metaplasia of the stomach, and in Paneth cell-rich adenomas. Differentiation and function of Paneth cells was monitored by Ki67, lysozyme, and morphologic features. Using a newly established monoclonal antibody, we found that calnexin is regularly synthesized by Paneth cells of normal small intestine. In these cells, the staining intensity of calnexin was inversely correlated with their content of secretory granules (lysozyme). In contrast, Paneth cells of intestinal metaplasia and Paneth cell-rich adenomas showed a reduced immunostaining of both calnexin and lysozyme. Moreover, these Paneth cells synthesized the proliferation marker Ki67, a phenomenon that was never observed in Paneth cells of normal small intestine. In vitro experiments using CaCo2 cells showed that the expression of calnexin is not directly affected by the induction of mitosis. In conclusion, calnexin probably reflects the status of Paneth cell differentiation and function. The results do not necessarily indicate that calnexin has a function in Paneth cell proliferation.
authors.affiliation: Department of Pathology, Heidelberg University, Mannheim, Germany. Nikolaus_Gassler@med.uni-heidelberg.de
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Gassler
authors.forename: Martina
authors.initials: M
authors.lastname: Schnölzer
authors.forename: Claudia
authors.initials: C
authors.lastname: Rohr
authors.forename: Burkhard
authors.initials: B
authors.lastname: Helmke
authors.forename: Jürgen
authors.initials: J
authors.lastname: Kartenbeck
authors.forename: Sylvia
authors.initials: S
authors.lastname: Grünewald
authors.forename: Rico
authors.initials: R
authors.lastname: Laage
authors.forename: Armin
authors.initials: A
authors.lastname: Schneider
authors.forename: Bettina
authors.initials: B
authors.lastname: Kränzlin
authors.forename: Alfred
authors.initials: A
authors.lastname: Bach
authors.forename: Herwart F
authors.initials: HF
authors.lastname: Otto
authors.forename: Frank
authors.initials: F
authors.lastname: Autschbach
mesh_terms: D000236:Adenoma / Q000378:metabolism / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018938:Caco-2 Cells / Q000378:metabolism / Q000473:pathology; D037281:Calnexin / Q000032:analysis / Q000096:biosynthesis*; D002454:Cell Differentiation / Q000502:physiology; D005260:Female; D005753:Gastric Mucosa / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D007421:Intestine, Small / Q000166:cytology / Q000378:metabolism; D019394:Ki-67 Antigen / Q000378:metabolism; D008297:Male; D008679:Metaplasia / Q000378:metabolism / Q000473:pathology; D008875:Middle Aged; D009113:Muramidase / Q000378:metabolism; D019879:Paneth Cells / Q000166:cytology* / Q000378:metabolism / Q000473:pathology; D022142:Secretory Vesicles / Q000201:enzymology; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013270:Stomach / Q000473:pathology; D013274:Stomach Neoplasms / Q000378:metabolism / Q000473:pathology
chemical_list: D019394:Ki-67 Antigen; D037281:Calnexin; D009113:Muramidase