Androgen-dependent regulation of human angiotensinogen expression in KAP-hAGT transgenic mice

2001 ◽  
Vol 280 (1) ◽  
pp. F54-F60 ◽  
Author(s):  
Yueming Ding ◽  
Curt D. Sigmund

We previously reported a novel transgenic model expressing human angiotensinogen from the kidney androgen-regulated protein promoter, and demonstrated sexually dimorphic expression. Herein, we investigated the hormonal regulation of this transgene. Testosterone increased transgene expression in female mice in a dose- and time-dependent manner and was not detectable 3-days after treatment was halted. High doses of estrogen were required to induce the transgene. Expression of transgene mRNA decreased after castration of male transgenic mice. As in females, however, transgene expression could be induced after administration of testosterone. Flutamide, an androgen receptor antagonist, dose dependently blocked transgene expression in males and blunted the induction caused by testosterone in females. Neither testosterone nor estrogen altered the proximal tubule cell-specific expression of the transgene. The data suggest that the level of transgene expression in this model can be controlled temporally and in magnitude by manipulating the levels of androgen. The fortuitous androgen regulation of this transgene can be used as a molecular “on-off” switch to control transgene expression and potentially manipulate blood pressure levels in this model.

Blood ◽  
1995 ◽  
Vol 85 (2) ◽  
pp. 319-329 ◽  
Author(s):  
S Dziennis ◽  
RA Van Etten ◽  
HL Pahl ◽  
DL Morris ◽  
TL Rothstein ◽  
...  

Abstract CD11b is the alpha chain of the Mac-1 integrin and is preferentially expressed in myeloid cells (neutrophils, monocytes, and macrophages). We have previously shown that the CD11b promoter directs cell-type- specific expression in myeloid lines using transient transfection assays. To confirm that these promoter sequences contain the proper regulatory elements for correct myeloid expression of CD11b in vivo, we have used the -1.7-kb human CD11b promoter to direct reporter gene expression in transgenic mice. Stable founder lines were generated with two different reporter genes, a Thy 1.1 surface marker and the Escherichia coli lacZ (beta-galactosidase) gene. Analysis of founders generated with each reporter demonstrated that the CD11b promoter was capable of driving high levels of transgene expression in murine macrophages for the lifetime of the animals. Similar to the endogenous gene, transgene expression was preferentially found in mature monocytes, macrophages, and neutrophils and not in myeloid precursors. These experiments indicate that the -1.7 CD11b promoter contains the regulatory elements sufficient for high-level macrophage expression. This promoter should be useful for targeting heterologous gene expression to mature myeloid cells.


1992 ◽  
Vol 12 (9) ◽  
pp. 3978-3990
Author(s):  
B Liu ◽  
G D Hammer ◽  
M Rubinstein ◽  
M Mortrud ◽  
M J Low

The proopiomelanocortin (POMC) gene is highly expressed in adult mouse pituitary anterior lobe corticotrophs and intermediate lobe melanotrophs. To identify the DNA elements important for this tissue-specific expression, we analyzed a series of POMC reporter genes in transgenic mice. A DNA fragment containing rat POMC 5'-flanking sequences from -323 to -34 recapitulated both basal pituitary cell-specific and hormonally stimulated expression in adult mice when fused to a heterologous thymidine kinase promoter. Developmental onset of the reporter gene expression lagged by 1 day but otherwise closely paralleled the normal ontogeny of murine POMC gene expression, including corticotroph activation at embryonic day 14.5 (E14.5) followed by melanotroph activation at E15.5 to E16.5. AtT20 corticotroph nuclear protein extracts interacted with three specific regions of the functional POMC promoter in DNase I protection assays. The positions of these protected sites were -107 to -160 (site 1), -182 to -218 (site 2), and -249 to -281 (site 3). Individual deletions of these footprinted sites did not alter transgene expression; however, the simultaneous deletion of sites 2 and 3 prevented transgene expression in both corticotrophs and melanotrophs. Electrophoretic mobility shift and Southwestern (DNA-protein) assays demonstrated that multiple AtT20 nuclear proteins bound to these footprinted sites. We conclude that the sequences between -323 and -34 of the rat POMC gene promoter are both necessary and sufficient for correct spatial, temporal, and hormonally regulated expression in the pituitary gland. Our data suggest that the three footprinted sites within the promoter are functionally interchangeable and act in combination with promoter elements between -114 and -34. The inability of any reporter gene construction to dissociate basal and hormonally stimulated expression suggests that these DNA elements are involved in both of these two characteristics of POMC gene expression in vivo.


2002 ◽  
Vol 88 (12) ◽  
pp. 984-991 ◽  
Author(s):  
William Sun ◽  
Mallory Coleman ◽  
David Witte ◽  
Sandra Degen

SummaryProthrombin has diverse biological functions in addition to its well established role in blood coagulation. In order to study these functions in more detail mouse model systems are needed. Since deficiency of prothrombin in mice results in partial embryonic lethality and neonatal death, alternative approaches are required to study the biology of prothrombin in the adult mouse. The liver is the major site of synthesis of prothrombin and therefore liver-specific promoters were used to express prothrombin in transgenic mice. Mice generated from crosses with these transgenic mice and mice hemizygous for the knock-out allele were used to test whether liver-specific expression is sufficient to correct the phenotype of null mice and whether liver-specific expression is sufficient for the development and survival of mice to adulthood. The mouse albumin promoter/enhancer was used initially for transgene expression without success in obtaining transgene positive, endogenous prothrombin null mice. Two lines of transgene positive, endogenous prothrombin deficient mice were obtained using the mouse transthyretin (TTR) promoter/enhancer driving expression of a human prothrombin cDNA. One line was able to rescue both the embryonic and the neonatal lethality while the other line was only able to correct the embryonic lethality. Expression of prothrombin was restricted to the liver and stomach in one line and to the liver, pancreas, stomach and kidney in the other line of mice. Thrombin activity for one line was determined to be at 5-10% of wildtype levels. These mice developed normally and did not have spontaneous bleeding events unless traumatized. Therefore, transgenic expression of human prothrombin is sufficient for the rescue of the lethality found for prothrombin deficiency in mice.


1987 ◽  
Vol 7 (10) ◽  
pp. 3749-3758
Author(s):  
V da C Soares ◽  
R M Gubits ◽  
P Feigelson ◽  
F Costantini

To investigate the tissue-specific and hormonal regulation of the rat alpha 2u globulin gene family, we introduced one cloned member of the gene family into the mouse germ line and studied its expression in the resulting transgenic mice. Alpha 2u globulingene 207 was microinjected on a 7-kilobase DNA fragment, and four transgenic lines were analyzed. The transgene was expressed at very high levels, specifically in the liver and the preputial gland of adult male mice. The expression in male liver was first detected at puberty, and no expression was detected in female transgenic mice. This pattern of expression is similar to the expression of endogenous alpha 2u globulin genes in the rat but differs from the expression of the homologous mouse major urinary protein (MUP) gene family in that MUPs are synthesized in female liver and not in the male preputial gland. We conclude that these differences between rat alpha 2u globulin and mouse MUP gene expression are due to evolutionary differences in cis-acting regulatory elements. The expression of the alpha 2u globulin transgene in the liver was abolished by castration and fully restored after testosterone replacement. The expression could also be induced in the livers of female mice by treatment with either testosterone or dexamethasone, following ovariectomy and adrenalectomy. Therefore, the cis-acting elements responsible for regulation by these two hormones, as well as those responsible for tissue-specific expression, are closely linked to the alpha 2u globulin gene.


1995 ◽  
Vol 268 (2) ◽  
pp. C283-C296 ◽  
Author(s):  
J. Noel ◽  
J. Pouyssegur

Since the cloning of the first member of the Na+/H+ exchanger (NHE) family, termed NHE1, four NHE isoforms have been cloned (NHE2, NHE3, NHE4, and the trout beta-NHE) and expressed in exchanger-deficient cell lines. All these isoforms exhibit significant identity to NHE1 and possess a similar hydropathy profile with two highly conserved transmembrane segments presumably involved in ion transport. These isoforms are allosterically activated by intracellular H+, regulate intracellular pH in a Na(+)-dependent manner, and are inhibited by amiloride and 5-amino derivatives with distinct Ki values. NHE1 is the amiloride-sensitive, growth factor-activatable, and ubiquitously expressed NHE known to regulate intracellular pH and cellular volume. NHE2, NHE3, and NHE4 are, however, restricted in their tissue distribution, suggesting roles in specialized functions of these epithelial tissues. In this review we present and discuss the most recent advances in the molecular and biochemical features, hormonal and growth factor activation, specific expression, and membrane sorting of the members of this NHE family.


1998 ◽  
Vol 9 (13) ◽  
pp. 1885-1898 ◽  
Author(s):  
Kevin S. Harrod ◽  
Terry W. Hermiston ◽  
Bruce C. Trapnell ◽  
William S. M. Wold ◽  
Jeffrey A. Whitsett

1992 ◽  
Vol 12 (9) ◽  
pp. 3978-3990 ◽  
Author(s):  
B Liu ◽  
G D Hammer ◽  
M Rubinstein ◽  
M Mortrud ◽  
M J Low

The proopiomelanocortin (POMC) gene is highly expressed in adult mouse pituitary anterior lobe corticotrophs and intermediate lobe melanotrophs. To identify the DNA elements important for this tissue-specific expression, we analyzed a series of POMC reporter genes in transgenic mice. A DNA fragment containing rat POMC 5'-flanking sequences from -323 to -34 recapitulated both basal pituitary cell-specific and hormonally stimulated expression in adult mice when fused to a heterologous thymidine kinase promoter. Developmental onset of the reporter gene expression lagged by 1 day but otherwise closely paralleled the normal ontogeny of murine POMC gene expression, including corticotroph activation at embryonic day 14.5 (E14.5) followed by melanotroph activation at E15.5 to E16.5. AtT20 corticotroph nuclear protein extracts interacted with three specific regions of the functional POMC promoter in DNase I protection assays. The positions of these protected sites were -107 to -160 (site 1), -182 to -218 (site 2), and -249 to -281 (site 3). Individual deletions of these footprinted sites did not alter transgene expression; however, the simultaneous deletion of sites 2 and 3 prevented transgene expression in both corticotrophs and melanotrophs. Electrophoretic mobility shift and Southwestern (DNA-protein) assays demonstrated that multiple AtT20 nuclear proteins bound to these footprinted sites. We conclude that the sequences between -323 and -34 of the rat POMC gene promoter are both necessary and sufficient for correct spatial, temporal, and hormonally regulated expression in the pituitary gland. Our data suggest that the three footprinted sites within the promoter are functionally interchangeable and act in combination with promoter elements between -114 and -34. The inability of any reporter gene construction to dissociate basal and hormonally stimulated expression suggests that these DNA elements are involved in both of these two characteristics of POMC gene expression in vivo.


1987 ◽  
Vol 7 (10) ◽  
pp. 3749-3758 ◽  
Author(s):  
V da C Soares ◽  
R M Gubits ◽  
P Feigelson ◽  
F Costantini

To investigate the tissue-specific and hormonal regulation of the rat alpha 2u globulin gene family, we introduced one cloned member of the gene family into the mouse germ line and studied its expression in the resulting transgenic mice. Alpha 2u globulingene 207 was microinjected on a 7-kilobase DNA fragment, and four transgenic lines were analyzed. The transgene was expressed at very high levels, specifically in the liver and the preputial gland of adult male mice. The expression in male liver was first detected at puberty, and no expression was detected in female transgenic mice. This pattern of expression is similar to the expression of endogenous alpha 2u globulin genes in the rat but differs from the expression of the homologous mouse major urinary protein (MUP) gene family in that MUPs are synthesized in female liver and not in the male preputial gland. We conclude that these differences between rat alpha 2u globulin and mouse MUP gene expression are due to evolutionary differences in cis-acting regulatory elements. The expression of the alpha 2u globulin transgene in the liver was abolished by castration and fully restored after testosterone replacement. The expression could also be induced in the livers of female mice by treatment with either testosterone or dexamethasone, following ovariectomy and adrenalectomy. Therefore, the cis-acting elements responsible for regulation by these two hormones, as well as those responsible for tissue-specific expression, are closely linked to the alpha 2u globulin gene.


Blood ◽  
1995 ◽  
Vol 85 (2) ◽  
pp. 319-329 ◽  
Author(s):  
S Dziennis ◽  
RA Van Etten ◽  
HL Pahl ◽  
DL Morris ◽  
TL Rothstein ◽  
...  

CD11b is the alpha chain of the Mac-1 integrin and is preferentially expressed in myeloid cells (neutrophils, monocytes, and macrophages). We have previously shown that the CD11b promoter directs cell-type- specific expression in myeloid lines using transient transfection assays. To confirm that these promoter sequences contain the proper regulatory elements for correct myeloid expression of CD11b in vivo, we have used the -1.7-kb human CD11b promoter to direct reporter gene expression in transgenic mice. Stable founder lines were generated with two different reporter genes, a Thy 1.1 surface marker and the Escherichia coli lacZ (beta-galactosidase) gene. Analysis of founders generated with each reporter demonstrated that the CD11b promoter was capable of driving high levels of transgene expression in murine macrophages for the lifetime of the animals. Similar to the endogenous gene, transgene expression was preferentially found in mature monocytes, macrophages, and neutrophils and not in myeloid precursors. These experiments indicate that the -1.7 CD11b promoter contains the regulatory elements sufficient for high-level macrophage expression. This promoter should be useful for targeting heterologous gene expression to mature myeloid cells.


Development ◽  
1993 ◽  
Vol 118 (1) ◽  
pp. 61-69 ◽  
Author(s):  
A. Patapoutian ◽  
J.H. Miner ◽  
G.E. Lyons ◽  
B. Wold

In developing mouse embryos, MyoD family regulatory genes are expressed specifically in muscle precursors and mature myofibers. This pattern, taken together with the well-established ability of MyoD family members to convert a variety of cell types to skeletal muscle, suggests a significant role for these genes in regulating skeletal myogenesis. The possibility that expression of these genes may be causally associated with segregation of the myogenic lineage from other mesodermal derivatives, or with the subsequent maintenance of muscle phenotypes at later times, raises the issue of how MyoD family genes are themselves regulated during development. In this work, we have initiated studies to identify DNA sequences that govern Myf-5 and MRF4 (herculin, myf-6) transcription. Myf-5 is the first of the MyoD family to be expressed in the developing mouse embryo, while MRF4 is the most abundantly expressed myogenic factor in postnatal animals. In spite of their strikingly divergent patterns of expression, Myf-5 and MRF4 are tightly linked in the mouse genome; their translational start codons are only 8.5 kilobases apart. Here, the 5′ flanking regions of the mouse Myf-5 and MRF4 genes were separately linked to a bacterial beta-galactosidase (lacZ) gene, and these constructs were each used to produce several lines of transgenic mice. Transgene expression was monitored by X-gal staining of whole embryos and by in situ hybridization of embryo sections. For the Myf-5/lacZ lines, the most intense transgene expression was in the visceral arches and their craniofacial muscle derivatives, beginning at day 8.75 post coitum (p.c.). This correlates with endogenous Myf-5 expression in visceral arches.(ABSTRACT TRUNCATED AT 250 WORDS)


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