Primary structure of hepatocyte nuclear factor/forkhead homologue 4 and characterization of gene expression in the developing respiratory and reproductive epithelium.

Abstract

Based upon previous studies defining a specific role for the HNF-3 factors in CCSP gene expression and the evidence that additional factors are required for regulation of CCSP gene expression, we hypothesized that other winged helix/forkhead factors may be involved in regulating gene expression and cellular differentiation in the bronchiolar epithelium. Consistent with this hypothesis, a winged helix/forkhead sequence termed hepatocyte nuclear factor/forkhead homologue 4 (HFH-4) is expressed in the lung but has not been characterized in terms of cell-specific or developmental expression (12). In this study, we have isolated the full-length cDNA encoding HFH-4 and defined the pattern of tissue-and cell-specific expression during development in the rat and mouse. MATERIALS AND METHODSIsolation and Characterization of Rat HFH-4. Oligonucleotides corresponding to the 5' (5'-AGCCACCCTACTCCTA-TGCCAC-3') and 3' (5'-GCAGCCTCCGCTTCTTGAAG-3') sequences of the murine HFH-4 forkhead domain (12) were used to PCR-amplify a 284-bp fragment from a rat lung cDNA library (Clontech). Sequence analysis confirmed that the isolated fragment encoded the rat homologue of the murine HFH-4 forkhead domain. After initial RNA blot analysis indicated that HFH-4 transcript was present in lung and testis, rat lung and testis cDNA libraries (Clontech) were screened at high stringency with a random-primed [32P]cDNA probe derived from the rat HFH-4 forkhead domain to obtain full-length clones encoding rat HFH-4. The nucleotide sequence of each clone was determined and the full-length sequence was determined from a series of overlapping clones.RNA Isolation and RNA Blot Analysis. Organs were isolated from rats or mice, rinsed in saline, and quick frozen in liquid nitrogen. Total RNA was isolated by dissolution of tissue in guanidinium isothiocyanate followed by cesium chloride density gradient centrifugation (13). RNA samples were denatured, electrophoresed, and transferred to nylon (Hybond-N, Amersham) as described (10). Abbreviations: CCSP, Clara cell secretory protein; HFH, hepatocyte nuclear factor/forkhead homologue; E, embryonic day; cRNA, complementary RNA.

TGF‐β1 perturbs vascular development and inhibits epithelial differentiation in fetal lung in vivo

“…HFH-4, a member of the winged helix/ forkhead family of transcription factors, is expressed in a number of tissues including lung, brain, oviduct, testis, and kidney (Hackett et al, 1995). In mouse lung, the expression of HFH-4 protein is restricted to subsets of the epithelial cells in the conducting airways from E17 and maintained postnatally.…”

Follistatin-like-1, a diffusible mesenchymal factor determines the fate of epithelium

“…1 A and B). Ovgp1 is one of the secretory proteins of the mouse oviduct (32,33), and Foxj1 is a transcription factor specifically involved in ciliogenesis (34)(35)(36). 6B, a cilial epithelial cell line, and AB, a secretory epithelial cell line, which were established from adult oviducts in our previous study (20), expressed Foxj1 and Ovgp1, respectively ( Fig.…”

The bone morphogenic protein antagonist gremlin regulates proximal‐distal patterning of the lung

“…HFH-4 (Foxj1) expression, which is normally confined to ciliated epithelial cells of the proximal airways, was expanded into the distal lung epithelium of SP-C/gremlin transgenic mice in a manner similar to that observed with the proximal Clara cell marker gene CC10 (Figs. 7E, 5F) (Hackett et al, 1995;Chen et al, 1998). These data demonstrate that expression of HFH-4 (Foxj1) was altered in SP-C/gremlin transgenic lungs.…”