scholarly journals Phenotypic Characterization of Transgenic Mice Expressing Human IGFBP-5

2020 ◽  
Vol 22 (1) ◽  
pp. 335
Author(s):  
Xinh-Xinh Nguyen ◽  
Matthew Sanderson ◽  
Kristi Helke ◽  
Carol Feghali-Bostwick

Pulmonary fibrosis is one of the important causes of morbidity and mortality in fibroproliferative disorders such as systemic sclerosis (SSc) and idiopathic pulmonary fibrosis (IPF). Insulin-like growth factor binding protein-5 (IGFBP-5) is a conserved member of the IGFBP family of proteins that is overexpressed in SSc and IPF lung tissues. In this study, we investigated the functional role of IGFBP-5 in the development of fibrosis in vivo using a transgenic model. We generated transgenic mice ubiquitously expressing human IGFBP-5 using CRISPR/Cas9 knock-in. Our data show that the heterozygous and homozygous mice are viable and express human IGFBP-5 (hIGFBP-5). Transgenic mice had increased expression of extracellular matrix (ECM) genes, especially Col3a1, Fn, and Lox in lung and skin tissues of mice expressing higher transgene levels. Histologic analysis of the skin tissues showed increased dermal thickness, and the lung histology showed subtle changes in the heterozygous and homozygous mice as compared with the wild-type mice. These changes were more pronounced in animals expressing higher levels of hIGFBP-5. Bleomycin increased ECM gene expression in wild-type mice and accentuated an increase in ECM gene expression in transgenic mice, suggesting that transgene expression exacerbated bleomycin-induced pulmonary fibrosis. Primary lung fibroblasts cultured from lung tissues of homozygous transgenic mice showed significant increases in ECM gene expression and protein levels, further supporting the observation that IGFBP-5 resulted in a fibrotic phenotype in fibroblasts. In summary, transgenic mice expressing human IGFBP-5 could serve as a useful animal model for examining the function of IGFBP-5 in vivo.

2020 ◽  
Vol 5 (52) ◽  
pp. eabc1884 ◽  
Author(s):  
Patricia P. Ogger ◽  
Gesa J. Albers ◽  
Richard J. Hewitt ◽  
Brendan J. O’Sullivan ◽  
Joseph E. Powell ◽  
...  

Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease in which airway macrophages (AMs) play a key role. Itaconate has emerged as a mediator of macrophage function, but its role during fibrosis is unknown. Here, we reveal that itaconate is an endogenous antifibrotic factor in the lung. Itaconate levels are reduced in bronchoalveolar lavage, and itaconate-synthesizing cis-aconitate decarboxylase expression (ACOD1) is reduced in AMs from patients with IPF compared with controls. In the murine bleomycin model of pulmonary fibrosis, Acod1−/− mice develop persistent fibrosis, unlike wild-type (WT) littermates. Profibrotic gene expression is increased in Acod1−/− tissue-resident AMs compared with WT, and adoptive transfer of WT monocyte-recruited AMs rescued mice from disease phenotype. Culture of lung fibroblasts with itaconate decreased proliferation and wound healing capacity, and inhaled itaconate was protective in mice in vivo. Collectively, these data identify itaconate as critical for controlling the severity of lung fibrosis, and targeting this pathway may be a viable therapeutic strategy.


2003 ◽  
Vol 285 (5) ◽  
pp. H2240-H2247 ◽  
Author(s):  
Elizabeth A. Nunamaker ◽  
Hai-Ying Zhang ◽  
Yuichi Shirasawa ◽  
Joseph N. Benoit ◽  
David A. Dean

The development of inexpensive and effective approaches to transiently decrease gene expression in vivo would be useful for the study of physiological processes in living animals. DNAzymes are a novel class of DNA oligonucleotides that can catalytically cleave target mRNAs and thereby reduce protein production. However, current methods for their delivery in vivo are limited and inefficient. In this study, we show that electroporation can be used to deliver DNAzymes to the intact mesenteric vasculature of rats. With the use of PKC-ϵ as a target, a set of wild-type and mutant control DNAzymes was designed and shown to reduce both PKC-ϵ mRNA and protein levels in cultured smooth muscle cells in a specific manner. The wild-type DNAzyme reduced PKC-ϵ protein levels by 70% at 24 h in two different cell lines without decreasing the levels of the five other PKC isoforms tested. When delivered to the intact vasculature using electroporation, the DNAzyme reduced PKC-ϵ protein levels by >60% without affecting these other PKC isoforms. Electroporation was required for oligonucleotide transfer and was able to deliver the DNAzymes to multiple cell layers in the vessel wall. Protein levels were reduced maximally by 24 h postelectroporation and returned to normal by 48 h. These results suggest that electroporation can be used to deliver DNAzymes and other DNA oligonucleotides to the vasculature in vivo and can decrease gene expression for a window of time that can be used for experimental studies.


Endocrinology ◽  
2003 ◽  
Vol 144 (5) ◽  
pp. 2111-2120 ◽  
Author(s):  
Antoine Martinez ◽  
Pierre Val ◽  
Isabelle Sahut-Barnola ◽  
Christelle Aigueperse ◽  
Georges Veyssière ◽  
...  

Aldo-keto-reductase 1B7/mouse vas deferens protein (AKR1B7/MVDP) is expressed in rodent steroidogenic glands and in the mouse vas deferens. In steroidogenic organs, AKR1B7/MVDP scavenges isocaproaldehyde produced from the cholesterol side-chain cleavage reaction. Akr1b7/mvdp is responsive to ACTH in adrenals and to androgens in vas deferens. Using transgenic mice, we previously delimited the regulatory DNA sequences necessary for expression in both organs and identified by cell transfections, a cryptic steroidogenic factor-1 (SF-1) response element (SFRE) at −102 that overlaps a proximal androgen-responsive element. To address its in vivo functions in adrenals, we devised a transgenic mouse study using wild-type and mutant akr1b7 promoters driving the chloramphenol acetyltransferase reporter gene. Adrenal expression in adults was impaired in all lines mutant for −102 SFRE. This effect is linked to impaired SF-1 binding and not to impaired androgen receptor binding, because akr1b7 expression is not affected in adrenals of androgen receptor-defective Tfm mice. Triphasic developmental patterns of both AKR1B7 and wild-type transgene expression paralleled changes in SF-1 levels/binding activity; expression was maximal in late embryos, minimal in 6- to 15-d-old neonates, and thereafter progressively restored. Differences in developmental expression between wild-type and mutant transgenes revealed that requirement for the −102 SFRE appears stage specific, as its integrity is an absolute prerequisite for reinduction of gene expression after postnatal d 15. Further, mutation of this site did not affect transgene responsiveness to ACTH. These findings demonstrate a new function for SFRE in vivo, via influencing promoter sensibility to postnatal changes of SF-1 contents, in controlling promoter strength in adults without affecting adrenal targeting, hormonal control, or early gene expression.


1996 ◽  
Vol 271 (3) ◽  
pp. E582-E586 ◽  
Author(s):  
G. Gomez ◽  
V. Udupi ◽  
X. Qi ◽  
F. Lluis ◽  
S. Rajaraman ◽  
...  

The purpose of these studies was to examine the effects of excess growth hormone (GH) on gastrin and peptide YY (PYY) gene expression. Transgenic mice with the bovine GH gene linked to a mouse metallothionein I promoter were used as a model of chronic GH excess. Antral gastrin mRNA and peptide levels were elevated significantly (P < 0.05) in GH transgenic mice compared with wild type littermates. Ileal PYY mRNA and ileal and colonic PYY levels were significantly elevated in GH transgenic mice compared with wild type littermates. The elevations in gastrin and PYY gene expression in GH transgenic mice were independent of food intake. Serum concentrations of gastrin and PYY were also elevated in GH transgenic mice. Immunohistochemical analysis showed that the density of PYY-containing cells in the colon of GH transgenic mice and wild type littermates did not differ. In addition, the mRNA and protein levels of chromogranin A, a marker of endocrine cells, were not increased in the colon of GH transgenic mice. Together, these data indicate that GH, insulin-like growth factor I, or both can upregulate gastrointestinal gastrin and PYY gene expression directly.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Robin Ray ◽  
Min Zhang ◽  
Alison C Brewer ◽  
Ajay M Shah

NADPH oxidases (Noxs) are major sources of reactive oxygen species (ROS) that are involved in the pathophysiology of several cardiovascular disorders. Of the 5 Nox isoforms identified to date, Nox2 and Nox4 are the main isoforms expressed in the endothelium. Whereas Nox2 has been implicated in the genesis of endothelial dysfunction, the role of Nox4 remains unclear. Interestingly, the activation mechanisms of Nox2 and Nox4 appear to be distinct. To specifically examine the function of endothelial Nox4 in vivo , we generated transgenic mice with endothelial-targeted overexpression of Nox4 using a Tie2 promoter construct. Nox4 transgenic mice (TG) backcrossed onto a C57BL/6J background had increased Nox4 mRNA in endothelial-rich tissues and in isolated coronary microvascular endothelial cells (CMEC) compared to wild-type littermates (WT) (2-fold increase in CMEC; p<0.001). Aortic Nox4 protein levels were 3-fold higher in TG compared to WT. CMEC isolated from TG mice had increased NADPH-dependent superoxide production compared to WT (237.6 ± 2.7 vs. 186.5 ± 7.1 integrated RLU; n = 3, p<0.01) as well as increased H 2 O 2 production (7.60 ± 0.70 vs. 3.22 ± 0.42 μM H 2 O 2 /105 cells; n=3, p<0.01). No changes were detected in mRNA expression of SOD1, SOD2, SOD3, catalase or eNOS in aorta of TG compared to WT mice. Isolated aortic rings from TG mice exhibited enhanced endothelial-dependent vasorelaxation to cumulative addition of acetylcholine compared to WT (−log EC 50 7.76 ± 0.07 vs. 7.20 ± 0.05; n =12, p<0.001), a difference that was abolished by catalase (1500 units/ml). There was no difference in endothelial-independent responses to sodium nitroprusside (−log EC 50 8.57 ± 0.11 vs. 8.54 ± 0.09; n = 12, p = NS). In vivo blood pressure measured both by tail-cuff plethysmography and ambulatory telemetry was significantly lower in TG compared to WT (systolic 117.4 ± 1.9 vs. 125.5 ± 2.1 mmHg and diastolic 90.1 ± 2.0 vs. 98.1 ± 2.1 mmHg by telemetry; n =5, p<0.05). These results indicate that modest endothelium-targeted overexpression of Nox4 in vivo enhances endothelium-dependent relaxation and reduces blood pressure, probably through increased generation of H 2 O 2 . These in vivo effects are quite distinct from those that have been found with Nox2 overexpression.


2008 ◽  
Vol 86 (8) ◽  
pp. 541-545 ◽  
Author(s):  
Philipp Kalk ◽  
Alexander Mach ◽  
Christa Thone-Reineke ◽  
Michael Godes ◽  
Susi Heiden ◽  
...  

Activation of the endothelin (ET) system promotes vasoconstriction, inflammation, and fibrosis in various tissues, including the lung. Therefore, ET-1 transgenic mice overexpressing ET-1 develop pulmonary fibrosis in a slow, age-dependent manner. In vivo, NO is the most important counterregulatory mediator of the ET system and decreases ET-1 promoter activity. The aim of our study was to elucidate the impact on pulmonary inflammation and fibrosis of the interaction between NO and the ET system in young ET-1 transgenic mice before the onset of pulmonary fibrosis. Male ET-1 transgenic mice and wild-type littermates at the age of 8 weeks were randomly allocated to the following 6 groups: WT (n = 11), wild-type animals without treatment; WT + l-NAME (n = 14), wild-type animals receiving l-NAME, an inhibitor of NO synthase; WT + l-NAME + LU (n = 13), wild-type animals receiving l-NAME and LU 302872, a dual ETA/ETB-receptor antagonist; ET1tg (n = 10), ET-1 transgenic mice; ET1tg + l-NAME (n = 13); and ET1tg + l-NAME + LU (n = 13). After 6 weeks, animals were euthanized, and hearts and lungs were harvested for histology and immunohistochemistry. No differences in pulmonary inflammation, as indicated by macrophage infiltration, or in interstitial fibrosis were observed between WT and ET1tg mice at baseline; however, inflammation and interstitial fibrosis were significantly enhanced in ET1tg mice, but not in WT groups, after l-NAME treatment. The combined ETA/ETB-receptor antagonist LU 302872 abolished inflammation and interstitial fibrosis in l-NAME-treated ET1tg mice. Perivascular fibrosis and media/lumen ratio of pulmonary bronchi and arteries did not differ between all study groups. In our study l-NAME induced pulmonary fibrosis and inflammation only in young ET1tg mice. Additional treatment with LU 302872 abolished these effects. We thus conclude that an imbalance between an activated ET system and a suppressed NO system contributes to pulmonary inflammation and fibrosis.


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.


2000 ◽  
Vol 14 (8) ◽  
pp. 1125-1136 ◽  
Author(s):  
Josep M. Colomer ◽  
Anthony R. Means

Abstract Although isoforms of Ca2+/calmodulin-dependent protein kinase II (CaMKII) have been implicated in the regulation of gene expression in cultured cells, this issue has yet to be addressed in vivo. We report that the overexpression of calmodulin in ventricular myocytes of transgenic mice results in an increase in the Ca2+/calmodulin-independent activity of endogenous CaMKII. The calmodulin transgene is regulated by a 500-bp fragment of the atrial natriuretic factor (ANF) gene promoter which, based on cell transfection studies, is itself known to be regulated by CaMKII. The increased autonomous activity of CaMKII maintains the activity of the transgene and establishes a positive feedforward loop, which also extends the temporal expression of the endogenous ANF promoter in ventricular myocytes. Both the increased activity of CaMKII and transcriptional activation of ANF are highly selective responses to the chronic overexpression of calmodulin. These results indicate that CaMKII can regulate gene expression in vivo and suggest that this enzyme may represent the Ca2+-dependent target responsible for reactivation of the ANF gene during ventricular hypertrophy.


2009 ◽  
Vol 284 (24) ◽  
pp. 16541-16552 ◽  
Author(s):  
Üzen Savas ◽  
Daniel E. W. Machemer ◽  
Mei-Hui Hsu ◽  
Pryce Gaynor ◽  
Jerome M. Lasker ◽  
...  

CYP4A11 transgenic mice (CYP4A11 Tg) were generated to examine in vivo regulation of the human CYP4A11 gene. Expression of CYP4A11 in mice yields liver and kidney P450 4A11 levels similar to those found in the corresponding human tissues and leads to an increased microsomal capacity for ω-hydroxylation of lauric acid. Fasted CYP4A11 Tg mice exhibit 2–3-fold increases in hepatic CYP4A11 mRNA and protein, and this response is absent in peroxisome proliferator-activated receptor α (PPARα) null mice. Dietary administration of either of the PPARα agonists, fenofibrate or clofibric acid, increases hepatic and renal CYP4A11 levels by 2–3-fold, and these responses were also abrogated in PPARα null mice. Basal liver CYP4A11 levels are reduced differentially in PPARα−/− females (>95%) and males (<50%) compared with PPARα−/+ mice. Quantitative and temporal differences in growth hormone secretion are known to alter hepatic lipid metabolism and to underlie sexually dimorphic gene expression, respectively. Continuous infusion of low levels of growth hormone reduced CYP4A11 expression by 50% in PPARα-proficient male and female transgenic mice. A larger decrease was observed for the expression of CYP4A11 in PPARα−/− CYP4A11 Tg male mice to levels similar to that of female PPARα-deficient mice. These results suggest that PPARα contributes to the maintenance of basal CYP4A11 expression and mediates CYP4A11 induction in response to fibrates or fasting. In contrast, increased exposure to growth hormone down-regulates CYP4A11 expression in liver.


Blood ◽  
2003 ◽  
Vol 102 (8) ◽  
pp. 2856-2861 ◽  
Author(s):  
Hongmin Sun ◽  
Tony L. Yang ◽  
Angela Yang ◽  
Xixi Wang ◽  
David Ginsburg

Abstract Coagulation factor V (FV) is a central regulator of the coagulation cascade. Circulating FV is found in plasma and within platelet α granules. The specific functions of these distinct FV pools are uncertain. We now report the generation of transgenic mice with FV gene expression restricted to either the liver or megakaryocyte/platelet lineage using bacterial artificial chromosome (BAC) constructs. Six of 6 independent albumin BAC transgenes rescue the neonatal lethal hemorrhage of FV deficiency. Rescued mice all exhibit liver-specific Fv expression at levels ranging from 6% to 46% of the endogenous Fv gene, with no detectable FV activity within the platelet pool. One of the 3 Pf4 BAC transgenes available for analysis also rescues the lethal FV null phenotype, with FV activity restricted to only the platelet pool (approximately 3% of the wild-type FV level). FV-null mice rescued by either the albumin or Pf4 BAC exhibit nearly normal tail bleeding times. These results demonstrate that Fv expression in either the platelet or plasma FV pool is sufficient for basal hemostasis. In addition, these findings indicate that the murine platelet and plasma FV pools are biosynthetically distinct, in contrast to a previous report demonstrating a plasma origin for platelet FV in humans.


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