An enhancer region determines hSP-B gene expression in bronchiolar and ATII epithelial cells in transgenic mice

Abstract

Regulation of the surfactant protein B gene (SP-B) is developmentally controlled and highly tissue specific. To elucidate the SP-B gene temporal/spatial expression pattern in lung development at the transcriptional level, a transgenic mouse model line carrying the human SP-B (hSP-B) 1.5-kb 5'-flanking regulatory region and the lacZ gene was established. Expression of hSP-B 1.5-kb lacZ gene started at the onset of lung formation [embryonic day 9 (E9)] and was restricted to epithelial cells throughout prenatal and postnatal lung development. In the adult lung, hSP-B 1.5-kb lacZ gene expression was restricted to bronchiolar and alveolar type II epithelial cells. In lung explant culturing studies, the hSP-B 1.5-kb lacZ gene was highly expressed in newly formed epithelial tubules during the respiratory branching process. In a second transgenic mouse line, an enhancer region, which binds to thyroid transcription factor-1, retinoic acid receptor, signal transducers and activators of transcription 3, and nuclear receptor coactivators (SRC-1, ACTR, TIF2, and CBP/p300), was deleted from the hSP-B 1.5-kb lacZ gene. The deletion abolished hSP-B lacZ gene expression in bronchiolar epithelial cells and significantly reduced its expression level in alveolar type II epithelial cells in transgenic mice.

The murine SP-C promoter directs type II cell-specific expression in transgenic mice

“…A separate study of the human SP-B promoter demonstrated that 1.5 kb directs lung and intestine expression in mice. An enhancer was mapped to the Ϫ500-to Ϫ331-bp region (27). The Ϫ236-to ϩ39-bp region of the rabbit SP-B promoter directed bronchoalveolar selective expression and transcriptional repression mapped in the distal Ϫ2,176-to Ϫ730-bp region (1).…”

Gene delivery by the hSP-B promoter to lung alveolar type II epithelial cells in LAL-knockout mice through bone marrow mesenchymal stem cells

“…For donor mice, hSP-B 1.5-kb lacZ reporter gene transgenic mice are an ideal choice for tracking AT II cells in vivo. 7 As demonstrated in Figure 1b, more than 90% of AT II cells isolated from hSP-B 1.5-kb lacZ transgenic mice showed b-galactosidase activity and were stained blue. In the wild-type AT II cell control, no blue staining was observed (Figure 1a).…”

“…At 2 weeks after in vitro cell proliferation, DNAs were purified from lalÀ/À adherent BMSCs. Using a pair of primers specific for the hSP-B 1.5-kb lacZ reporter gene construct that was originally used for genotyping hSP-B 1.5-kb lacZ transgenic mice, 7 a PCR assay was performed. In this study, a PCR product with the matched size of the positive control was generated ( Figure 4b).…”

“…In a transgenic mouse model line carrying the hSP-B 1.5-kb 5 0 -flanking regulatory sequence and the lacZ reporter gene, expression of the b-galactosidase recapitulated the endogenous SP-B gene expression during lung development and in the adult lung. 7 The hSP-B promoter has the potential to deliver 'genes of interest' to AT II cells through BMSCs. To test this feasibility, a bone marrow transplantation study was performed using hSP-B 1.5-kb lacZ reporter transgenic mice as a donor system and lalÀ/À mice as a recipient system.…”

Overexpression of Dominant Negative Peroxisome Proliferator-Activated Receptor-γ (PPARγ) in Alveolar Type II Epithelial Cells Causes Inflammation and T-Cell Suppression in the Lung

“…17 BMSCs were isolated from femur and tibia of hSP-B 1.5kb lacZ transgenic mice, 2 to 3 months old, 18 and then were cultured in Mesencult MSC basal medium (StemCell Technologies, Vancouver, BC, Canada) at 37°C with 5% CO 2 . After 1 day, the unattached cells were discarded and, for attached BMSCs, the medium was completely replaced.…”