Genetic element from human surfactant protein SP-C gene confers bronchiolar-alveolar cell specificity in transgenic mice

Abstract

Transgenic mice bearing chimeric genes consisting of 5'-sequences derived from the human surfactant protein C (SP-C) gene and the bacterial chloramphenicol acetyltransferase (CAT) gene were generated. Analysis of CAT activity was utilized to demonstrate tissue-specific and developmental expression of chimeric genes containing 3.7 kb of sequences from the human SP-C gene. Lung-specific expression of the 3.7 SP-C-CAT transgene was observed in eight distinct transgenic mouse lines. Expression of the 3.7 SP-C-CAT transgene was first detected in fetal lung on day 11 of gestation and increased dramatically with advancing gestational age, reaching adult levels of activity before birth. In situ hybridization demonstrated that expression of 3.7 SP-C-CAT mRNA was confined to the distal respiratory epithelium. Antisense CAT hybridization was detected in bronchiolar and type II epithelial cells in the adult lung of the 3.7 SP-C-CAT transgenic mice. In situ hybridization of four distinct 3.7 SP-C-CAT transgenic mouse lines demonstrated bronchiolar-alveolar expression of the chimeric CAT gene, although the relative intensity of expression at each site varied within the lines studied. Glucocorticoids increased murine SP-C mRNA in fetal lung organ culture. Likewise, expression of 3.7 SP-C-CAT transgene increased during fetal lung organ or explant culture and was further enhanced by glucocorticoid in vitro. The 5'-regions of human SP-C conferred developmental, lung epithelial, and glucocorticoid-enhanced expression of bacterial CAT in transgenic mice. The increased expression of SP-C accompanying prenatal lung development and exposure to glucocorticoid is mediated, at least in part, at the transcriptional level, being influenced by cis-active elements contained within the 5'-flanking region of the human SP-C gene.

Constitutive activation of Notch3 inhibits terminal epithelial differentiation in lungs of transgenic mice

“…The pattern of expression is most prominent in the lung peripheral epithelium, consistent with previous published studies of transgenic mice bearing the SP-C promoter constructs (Glasser et al, 1991;Wert et al, 1993;Zhou et al, 1997;Zeng et al, 2001). …”

“…In these transgenic embryos, the pancreatic epithelium was poorly branched and reduced in size. The variability in branching morphogenesis seen in the SP-C-N3IC transgenics may be a result of the transcription of SP-C gene as early as E10.5, when branching morphogenesis is still occurring, and the differences in the expression among transgenics (Glasser et al, 1991).…”

“…The murine SPC-Notch3 construct was synthesized by subcloning and blunting the 2.0 kb KpnI and NsiI fragment of the Notch3 intracellular domain (N3IC) (a gift from Urban Lendhal at Karolinska Institute, Stockholm, Sweden) into the blunted, unique SalI and EcoRI sites of the human SPCpromoter plasmid SP-C-3.7 SV40 t-intron-polyA (gift from J Whitsett) (Glasser et al, 1991). The proper orientation of the construct was verified by restriction enzyme digestion and sequencing.…”

Transgenic cyclin E triggers dysplasia and multiple pulmonary adenocarcinomas

“…Transgenes were each driven by the human surfactant C (SP-C) promoter ( Fig. 2A), which conferred expression in alveolar type II and bronchioalveolar cells (23). Two independent WT cyclin E and two independent degradation-resistant cyclin E founder mice were identified by Southern blot analyses (data not shown).…”

Surfactant Protein–C Chromatin-Bound Green Fluorescence Protein Reporter Mice Reveal Heterogeneity of Surfactant Protein C–Expressing Lung Cells

“…These animals exhibited either a limited expression of GFP only in some AT2 cells (27), or a broad expression of GFP in both bronchiolar and AT2 cells (29). Previous studies also demonstrated the importance of species-specific promoter use for proper AT2 cell expression (30,31). Further detailed analysis of the murine SPC gene promoter revealed the particular sequences needed for (Received in original form November 22, 2011 and in final form October 19, 2012) AT2 cell-specific expression (32).…”