TY - JOUR
T1 - Modulation of Notch processing by γ-secretase inhibitors causes intestinal goblet cell metaplasia and induction of genes known to specify gut secretory lineage differentiation
AU - Milano, Joseph
AU - McKay, Jenny
AU - Dagenais, Claude
AU - Foster-Brown, Linda
AU - Pognan, Francois
AU - Gadient, Reto
AU - Jacobs, Robert T.
AU - Zacco, Anna
AU - Greenberg, Barry
AU - Ciaccio, Paul J.
PY - 2004/11
Y1 - 2004/11
N2 - It is anticipated that γ-secretase inhibitors (γ-Sec-I) that modulate Notch processing will alter differentiation in tissues whose architecture is governed by Notch signaling. To explore this hypothesis, Han Wistar rats were dosed for up to 5 days with 10-100 μmol/kg b.i.d. γ-Sec-I from three chemical series that inhibit Notch processing in vitro at various potencies (Notch IC50). These included an arylsulfonamide (AS) (142 nM), a dibenzazepine (DBZ) (1.7 nM), and a benzodiazepine (BZ) (2.2 nM). The DBZ and BZ caused dose-dependent intestinal goblet cell metaplasia. In contrast, the AS produced no detectable in vivo toxicity, despite higher exposure to free drug. In a time course using BZ, small intestinal crypt cell and large intestinal glandular cell epithelial apoptosis was observed on days 1-5, followed by goblet cell metaplasia on days 2-5 and crypt epithelial and glandular epithelial regenerative hyperplasia on days 4-5. Gene expression profiling of duodenal samples from BZ-dosed animals revealed significant time-dependent deregulation of mRNAs for various panendocrine, hormonal, and transcription factor genes. Somatostatin, secretin, mucin, CCK, and gastrin mRNAs were elevated twofold or more by day 2, and a number of candidate 'early-predictive' genes were altered on days 1-2, remaining changed for 4-5 days; these included Delta1, NeuroD, Hes1-regulated adipsin, and the Hes-regulated transcriptional activator of gut secretory lineage differentiation, the rat homolog of Drosophila atonal, Rath1. Western blotting of fecal protein from BZ-and DBZ-dosed animals exhibited increased levels of both anti-Rath1 reactive protein and anti-adipsin reactive proteins, confirming their potential value as noninvasive biomarkers of intestinal goblet metaplasia.
AB - It is anticipated that γ-secretase inhibitors (γ-Sec-I) that modulate Notch processing will alter differentiation in tissues whose architecture is governed by Notch signaling. To explore this hypothesis, Han Wistar rats were dosed for up to 5 days with 10-100 μmol/kg b.i.d. γ-Sec-I from three chemical series that inhibit Notch processing in vitro at various potencies (Notch IC50). These included an arylsulfonamide (AS) (142 nM), a dibenzazepine (DBZ) (1.7 nM), and a benzodiazepine (BZ) (2.2 nM). The DBZ and BZ caused dose-dependent intestinal goblet cell metaplasia. In contrast, the AS produced no detectable in vivo toxicity, despite higher exposure to free drug. In a time course using BZ, small intestinal crypt cell and large intestinal glandular cell epithelial apoptosis was observed on days 1-5, followed by goblet cell metaplasia on days 2-5 and crypt epithelial and glandular epithelial regenerative hyperplasia on days 4-5. Gene expression profiling of duodenal samples from BZ-dosed animals revealed significant time-dependent deregulation of mRNAs for various panendocrine, hormonal, and transcription factor genes. Somatostatin, secretin, mucin, CCK, and gastrin mRNAs were elevated twofold or more by day 2, and a number of candidate 'early-predictive' genes were altered on days 1-2, remaining changed for 4-5 days; these included Delta1, NeuroD, Hes1-regulated adipsin, and the Hes-regulated transcriptional activator of gut secretory lineage differentiation, the rat homolog of Drosophila atonal, Rath1. Western blotting of fecal protein from BZ-and DBZ-dosed animals exhibited increased levels of both anti-Rath1 reactive protein and anti-adipsin reactive proteins, confirming their potential value as noninvasive biomarkers of intestinal goblet metaplasia.
KW - Adipsin
KW - Atonal
KW - Hes1
KW - Intestinal goblet metaplasia
KW - NICD
KW - Notch intracellular domain
KW - Notch receptor
KW - Rath1
KW - γ-Secretase
UR - http://www.scopus.com/inward/record.url?scp=8444247084&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=8444247084&partnerID=8YFLogxK
U2 - 10.1093/toxsci/kfh254
DO - 10.1093/toxsci/kfh254
M3 - Article
C2 - 15319485
AN - SCOPUS:8444247084
SN - 1096-6080
VL - 82
SP - 341
EP - 358
JO - Toxicological Sciences
JF - Toxicological Sciences
IS - 1
ER -