Pepsinogen C: a type 2 cell-specific protease.
Pepsinogen C, also known as progastricsin or pepsinogen II, is an aspartic protease expressed primarily in gastric chief cells. Prior microarray studies of an in vitro model of type 2 cell differentiation indicated that pepsinogen C RNA was highly induced, comparable to surfactant protein RNA induction. Using second-trimester human fetal lung, third-trimester postnatal and adult lung, and a model of type 2 cell differentiation, we examined the specificity of pepsinogen C expression in lung. Pepsinogen C RNA and protein were only detected in >22 wk gestation samples of neonatal lung or in adult lung tissue. By immunohistochemistry and in situ hybridization, pepsinogen C expression was restricted to type 2 cells. Pepsinogen C expression was rapidly induced during type 2 cell differentiation and rapidly quenched with dedifferentiation of type 2 cells after withdrawal of hormones. In all samples, pepsinogen C expression occurred concomitantly with or in advance of processing of surfactant protein-B to its mature 8-kDa form. Our results indicate that pepsinogen C is a type 2 cell-specific marker that exhibits tight developmental regulation in vivo during human lung development, as well as during in vitro differentiation and dedifferentiation of type 2 cells.
Abramson Research Center 416G, Children's Hospital of Philadelphia, 3516 Civic Center Blvd., Philadelphia, PA 19104-4318, USA.
Cherie
C
Foster
Amana
A
Aktar
Denel
D
Kopf
Peggy
P
Zhang
Susan
S
Guttentag
D015415:Biomarkers; D002454:Cell Differentiation; D002478:Cells, Cultured; D015536:Down-Regulation; D005333:Fetus; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D020115:Pepsinogen C / Q000235:genetics* / Q000378:metabolism*; D020545:Respiratory Mucosa / Q000166:cytology / Q000196:embryology* / Q000201:enzymology*; D013379:Substrate Specificity
D015415:Biomarkers; D020115:Pepsinogen C