In-vivo protection from SARS-CoV-2 infection by ATN-161 in k18-hACE2 transgenic mice

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.

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Interactions of insulin-like growth factor (IGF)-II and growth hormone in vivo: circulating levels of IGF-I and IGF-binding proteins in transgenic mice

Acta Endocrinologica ◽

10.1530/eje.0.1370701 ◽

1997 ◽

pp. 701-708 ◽

Cited By ~ 15

Author(s):

A Blackburn ◽

RA Dressendorfer ◽

WF Blum ◽

M Erhard ◽

G Brem ◽

...

Keyword(s):

Transgenic Mice ◽

Transgene Expression ◽

High Protein Diet ◽

High Protein ◽

Protein Diet ◽

Standard Diet ◽

Igf I ◽

Igf Binding ◽

B Mice

To study interactions between insulin-like growth factor-II (IGF-II) and growth hormone (GH) in vivo, we crossed hemizygous transgenic mice carrying phosphoenolpyruvate carboxykinase (PEPCK)-IGF-II fusion genes with hemizygous PEPCK-bovine GH (bGH) transgenic mice. Offspring harbouring both transgenes (IB), the IGF-II transgene (I) or the bGH transgene (B), and non-transgenic littermates (C) were obtained. Blood samples were taken before (end of week 12) and after (end of week 14) the mice had received a diet high in protein and low in carbohydrates to stimulate PEPCK promoter-controlled transgene expression. Mean serum GH concentrations of both B and IB mice corresponded to 900 ng/ml and increased more than twofold (P < 0.001) after 1 week of the high-protein diet. GH concentrations in controls and I mice were less than 20 ng/ml. Serum IGF-II concentrations in I and IB mice were three-to fourfold higher than those in C and B mice. Whereas IGF-II concentrations were not changed by the high-protein diet in the last two groups, serum IGF-II increased significantly in I (P < 0.001) and IB mice (P < 0.05). This increase was significantly (P < 0.05) less pronounced in IB than in C and I mice. Circulating IGF-I concentrations were about twofold (P < 0.001) higher in B and IB than in C and I mice, and showed a tendency to be lower in I than in C and in IB than in B mice when animals were maintained on the standard diet. The high-protein diet did not change circulating IGF-I concentrations in controls and B mice, but resulted in a significant reduction of serum IGF-I concentrations in I (P < 0.05) and IB mice (P < 0.001). Consequently, after PEPCK-IGF-II transgene expression was stimulated, serum IGF-I concentrations were significantly (P < 0.05) lower in I than in C and in IB than in B mice. Serum IGF-binding protein (IGFBP)-2 concentrations were significantly (P < 0.05) higher in I mice than in all other groups when mice were maintained on the standard diet, with a tendency to reduced IGFBP-2 concentrations in B mice. After the high-protein diet, serum IGFBP-2 concentrations did not change in C and I mice, but increased by two- to threefold in B and IB mice (P < 0.001). Serum IGFBP-3 concentrations tended to be greater in B and IB than in C and I mice, but these differences were mostly not significant. IGFBP-4 concentrations were significantly (P < 0.001) increased by GH overproduction in B and IB mice. Our data suggest that the reduction in circulating IGF-I concentrations by increased IGF-II is most probably due to the limited serum IGF binding capacity and the short half-life of free IGFs, rather than to a reduction in GH-dependent IGF-I production. Effects of GH overproduction on serum IGFBP-2 concentrations depend on dietary factors and may be both inhibitory and stimulatory.

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p90 ribosomal S6 kinase 3 contributes to cardiac insufficiency in α-tropomyosin Glu180Gly transgenic mice

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00237.2013 ◽

2013 ◽

Vol 305 (7) ◽

pp. H1010-H1019 ◽

Cited By ~ 10

Author(s):

Catherine L. Passariello ◽

Marjorie Gayanilo ◽

Michael D. Kritzer ◽

Hrishikesh Thakur ◽

Zoharit Cozacov ◽

...

Keyword(s):

Heart Failure ◽

Transgenic Mice ◽

Cardiac Function ◽

Interstitial Fibrosis ◽

Cardiac Insufficiency ◽

S6 Kinase ◽

Transgenic Expression ◽

P90 Ribosomal S6 Kinase ◽

Ribosomal S6 Kinase

Myocardial interstitial fibrosis is an important contributor to the development of heart failure. Type 3 p90 ribosomal S6 kinase (RSK3) was recently shown to be required for concentric myocyte hypertrophy under in vivo pathological conditions. However, the role of RSK family members in myocardial fibrosis remains uninvestigated. Transgenic expression of α-tropomyosin containing a Glu180Gly mutation (TM180) in mice of a mixed C57BL/6:FVB/N background induces a cardiomyopathy characterized by a small left ventricle, interstitial fibrosis, and diminished systolic and diastolic function. Using this mouse model, we now show that RSK3 is required for the induction of interstitial fibrosis in vivo. TM180 transgenic mice were crossed to RSK3 constitutive knockout ( RSK3−/−) mice. Although RSK3 knockout did not affect myocyte growth, the decreased cardiac function and mild pulmonary edema associated with the TM180 transgene were attenuated by RSK3 knockout. The improved cardiac function was consistent with reduced interstitial fibrosis in the TM180; RSK3−/− mice as shown by histology and gene expression analysis, including the decreased expression of collagens. The specific inhibition of RSK3 should be considered as a potential novel therapeutic strategy for improving cardiac function and the prevention of sudden cardiac death in diseases in which interstitial fibrosis contributes to the development of heart failure.

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In vivo mutagenicity and mutation spectrum in the bone marrow and testes of B6C3F1 lacI transgenic mice following inhalation exposure to ethylene oxide

Mutagenesis ◽

10.1093/mutage/geh017 ◽

2004 ◽

Vol 19 (3) ◽

pp. 215-222 ◽

Cited By ~ 16

Author(s):

Leslie Recio ◽

Maria Donner ◽

Diane Abernethy ◽

Linda Pluta ◽

Ann‐Marie Steen ◽

...

Keyword(s):

Bone Marrow ◽

Transgenic Mice ◽

Ethylene Oxide ◽

Inhalation Exposure ◽

Mutation Spectrum ◽

In Vivo Mutagenicity

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The c-myc proto-oncogene regulates cardiac development in transgenic mice.

Molecular and Cellular Biology ◽

10.1128/mcb.10.7.3709 ◽

1990 ◽

Vol 10 (7) ◽

pp. 3709-3716 ◽

Cited By ~ 128

Author(s):

T Jackson ◽

M F Allard ◽

C M Sreenan ◽

L K Doss ◽

S P Bishop ◽

...

Keyword(s):

Transgenic Mice ◽

Mrna Expression ◽

Cardiac Myocyte ◽

Cellular Proliferation ◽

Cardiac Development ◽

Constitutive Expression ◽

Transgenic Animals ◽

Hypertrophic Growth ◽

Myocyte Proliferation

During the maturation of the cardiac myocyte, a transition occurs from hyperplastic to hypertrophic growth. The factors that control this transition in the developing heart are unknown. Proto-oncogenes such as c-myc have been implicated in the regulation of cellular proliferation and differentiation, and in the heart the switch from myocyte proliferation to terminal differentiation is synchronous with a decrease in c-myc mRNA abundance. To determine whether c-myc can influence myocyte proliferation or differentiation, we examined the in vivo effect of increasing c-myc expression during embryogenesis and of preventing the decrease in c-myc mRNA expression that normally occurs during cardiac development. The model system used was a strain of transgenic mice exhibiting constitutive expression of c-myc mRNA in cardiac myocytes throughout development. In these transgenic mice, increased c-myc mRNA expression was found to be associated with both atrial and ventricular enlargement. This increase in cardiac mass was secondary to myocyte hyperplasia, with the transgenic hearts containing more than twice as many myocytes as did nontransgenic hearts. The results suggest that in the transgenic animals there is additional hyperplastic growth during fetal development. However, this additional proliferative growth is not reflected in abnormal myocyte maturation, as assessed by the expression of the cardiac and skeletal isoforms of alpha-actin. The results of this study indicate that constitutive expression of c-myc mRNA in the heart during development results in enhanced hyperplastic growth and suggest a regulatory role for this proto-oncogene in cardiac myogenesis.

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Chronic Elevation of Calmodulin in the Ventricles of Transgenic Mice Increases the Autonomous Activity of Calmodulin-Dependent Protein Kinase II, Which Regulates Atrial Natriuretic Factor Gene Expression

Molecular Endocrinology ◽

10.1210/mend.14.8.0496 ◽

2000 ◽

Vol 14 (8) ◽

pp. 1125-1136 ◽

Cited By ~ 21

Author(s):

Josep M. Colomer ◽

Anthony R. Means

Keyword(s):

Gene Expression ◽

Protein Kinase ◽

Transgenic Mice ◽

Atrial Natriuretic Factor ◽

Ventricular Myocytes ◽

Dependent Protein Kinase ◽

Natriuretic Factor ◽

Dependent Protein ◽

Autonomous Activity

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.

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