Ischemia, fibrosis, and remodeling lead to heart failure after severe myocardial infarction (MI). Myoblast sheet transplantation is a promising therapy to enhance cardiac function and induce therapeutic angiogenesis via a paracrine mechanism in this detrimental disease. We hypothesized that in a rat model of MI-induced chronic heart failure this therapy could further be improved by overexpression of the antiapoptotic, antifibrotic, and proangiogenic hepatocyte growth factor (HGF) in the myoblast sheets. We studied the ability of wild type (L6-WT) and human HGF-expressing (L6-HGF) L6 myoblast sheet-derived paracrine factors to stimulate cardiomyocyte, endothelial cell, or smooth muscle cell migration in culture. Further, we studied the autocrine effect of hHGF-expression on myoblast gene expression using microarray analysis. We induced MI in Wistar rats by left anterior descending coronary artery (LAD) ligation and allowed heart failure to develop for four weeks. Thereafter, we administered L6-WT (n=15) or L6-HGF (n=16) myoblast sheet therapy. Control rats (n=13) underwent LAD ligation and rethoracotomy without therapy and five rats underwent sham-operation in both surgeries. We evaluated cardiac function with echocardiography at 2 and 4 weeks after therapy administration. We analyzed cardiac angiogenesis and left ventricular architecture from histological sections 4 weeks after therapy. Paracrine mediators from L6-HGF myoblast sheets effectively induced migration of cardiac endothelial and smooth muscle cells but not cardiomyocytes. Microarray data revealed that hHGF-expression modulated myoblast gene expression. In vivo, L6-HGF sheet therapy effectively stimulated angiogenesis in the infarcted and non-infarcted areas. Both L6-WT and L6-HGF therapies enhanced cardiac function and inhibited remodeling in a similar fashion. In conclusion, L6-HGF therapy effectively induced angiogenesis in the chronically failing heart. Cardiac function, however, was not further enhanced by hHGF-expression.
hHGF overexpression in myoblast sheets enhances their angiogenic potential in rat chronic heart failure.
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View SamplesThese cultures were grown to examine the differences in Agr-regulated virulence factor gene expression between wild-type S. aureus FRI1169 and a non-hemolytic variant isolated from a biofilm inoculated with FRI1169. The study is described more thoroughly in the paper "Generation of virulence factor variants in Staphylococcus aureus biofilms", Yarwood et al., J. Bacteriol. 2007.
Generation of virulence factor variants in Staphylococcus aureus biofilms.
No sample metadata fields
View SamplesWe ovexpressed human alpha synuclein alone or together with Nurr1 in mouse primary midbrain cultures and identified the full spectrum of genes whose expression is affected by alpha synuclein, including genes whose expression is normalized after Nurr1 overexpression. Moreover we treated mouse primary midbrain cultures with Bexarotene or short hairpin RNA fro Nurr1, sorted out the dopamine neurons and assessed the effects of Bexarotene and of the Nurr1 downregulation on gene expression. Overall design: Comparison of 3 Synuclein samples to 5 controls (RFP), Comparison of 3 Synuclein + Nurr1 samples to 5 controls (RFP), Comparison of 3 Bexarotene samples to 3 controls (DMSO), comparison of 1 short hairpin against Nurr1 to 1 control (scrambled).
Nurr1 and Retinoid X Receptor Ligands Stimulate Ret Signaling in Dopamine Neurons and Can Alleviate α-Synuclein Disrupted Gene Expression.
No sample metadata fields
View SamplesT-cell acute lymphoblastic leukemia (T-ALL) is a malignancy of T cell progenitors that in most patients is associated with activating mutations in the NOTCH1 pathway. Recent reports have indicated a link between Ca2+ homeostasis in the endoplasmic reticulum (ER), the regulation of NOTCH1 signaling and T-ALL. Here we investigated the role of store-operated Ca2+ entry (SOCE) in T-ALL. SOCE is a Ca2+ influx pathway that is mediated by the plasma membrane Ca2+ channel ORAI1 and its activators STIM1 and STIM2. Deletion of STIM1 and STIM2 in leukemic cells abolished SOCE and significantly prolonged the survival of mice in a NOTCH1-driven model of T-ALL. The survival advantage was unrelated to leukemia development and leukemic cell burden, but was associated with the SOCE-dependent ability of malignant T lymphoblasts to cause inflammation in leukemia-infiltrated organs. Mice with wildtype T-ALL showed a severe necroinflammatory response in their bone marrow, which was absent in mice with Stim1/2-/- leukemia. Several signaling pathways previously linked to cancer-induced inflammation were downregulated in Stim1/2-/- leukemic cells, likely accounting for less aggressive leukemia progression and prolonged survival of mice. Our study shows that T-ALL is associated with inflammation of leukemia-infiltrated organs and that SOCE controls the proinflammatory effects of leukemic T lymphoblasts. Overall design: Bone marrow leukemic cell were isolated from WT and Stim1/2-/- leukemic mice, 21 days after leukemia induction and their mRNA profiles were generated by deep sequencing, in triplicate.
STIM1 and STIM2 Mediate Cancer-Induced Inflammation in T Cell Acute Lymphoblastic Leukemia.
Specimen part, Cell line, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
In vivo mapping of notch pathway activity in normal and stress hematopoiesis.
Sex, Age, Specimen part
View SamplesLRAT knockout mice on vitamin A sufficient or deficient diets were compared to age-matched wildtype mice on a vitamin A sufficient diet
Effects of vitamin A deficiency in the postnatal mouse heart: role of hepatic retinoid stores.
Sex, Specimen part
View SamplesLRAT knockout mice on vitamin A sufficient or deficient diets were compared to age and gender matched wildtype mice on a vitamin A sufficient diet
Effects of vitamin A deficiency in the postnatal mouse heart: role of hepatic retinoid stores.
Sex, Specimen part
View SamplesNotch signaling defines a conserved, fundamental pathway, responsible for determination in metazoan development and is widely recognized as an essential component of lineage specific differentiation and stem cell self-renewal in many tissues including the hematopoietic system. Until recently, the majority of studies in the hematopoietic system focused on Notch signaling in lymphocyte differentiation and knowledge of individual Notch receptor roles in early hematopoiesis has been limited due to a paucity of genetic tools available To fate-map Notch receptor expression and pathway activity in the hematopoietic system we used tamoxifen-inducible CreER knock-in mice for individual Notch receptors in combination to a novel Notch reporter strain (Hes1GFP) and a conditional gain of function allele of Notch2 receptor (Rosa-lsl-ICN2).
In vivo mapping of notch pathway activity in normal and stress hematopoiesis.
Sex, Age, Specimen part
View SamplesNotch signaling defines a conserved, fundamental pathway, responsible for determination in metazoan development and is widely recognized as an essential component of lineage specific differentiation and stem cell self-renewal in many tissues including the hematopoietic system. Until recently, the majority of studies in the hematopoietic system focused on Notch signaling in lymphocyte differentiation and knowledge of individual Notch receptor roles in early hematopoiesis has been limited due to a paucity of genetic tools available To fate-map Notch receptor expression and pathway activity in the hematopoietic system we used tamoxifen-inducible CreER knock-in mice for individual Notch receptors in combination to a novel Notch reporter strain (Hes1GFP) and a conditional gain of function allele of Notch2 receptor (Rosa-lsl-ICN2).
In vivo mapping of notch pathway activity in normal and stress hematopoiesis.
Sex, Age, Specimen part
View SamplesNotch signaling defines a conserved, fundamental pathway, responsible for determination in metazoan development and is widely recognized as an essential component of lineage specific differentiation and stem cell self-renewal in many tissues including the hematopoietic system. Until recently, the majority of studies in the hematopoietic system focused on Notch signaling in lymphocyte differentiation and knowledge of individual Notch receptor roles in early hematopoiesis has been limited due to a paucity of genetic tools available To fate-map Notch receptor expression and pathway activity in the hematopoietic system we used tamoxifen-inducible CreER knock-in mice for individual Notch receptors in combination to a novel Notch reporter strain (Hes1GFP) and a conditional gain of function allele of Notch2 receptor (Rosa-lsl-ICN2).
In vivo mapping of notch pathway activity in normal and stress hematopoiesis.
Sex, Age, Specimen part
View Samples