Multipotent stromal cells (MSCs) are currently in clinical trials for a number of inflammatory diseases. Recent studies have demonstrated the ability of MSCs to attenuate inflammation in rodent models of acute lung injury (ALI) suggesting that MSCs may also be beneficial in treating ALI. To better understand how human MSCs (hMSCs) may act in ALI, the lungs of immunocompetent mice were exposed to lipopolysaccharide (LPS) and 4 hr later bone marrow derived hMSCS were delivered by oropharyngeal aspiration (OA). Administration of hMSCs significantly reduced the expression of pro-inflammatory cytokines, neutrophil counts and total protein in bronchoalveolar lavage. There was a concomitant reduction in pulmonary edema as indicated by a decrease in lung wet/dry weight ratio. The anti-inflammatory effects of hMSCs were not dependent on localization to the lung, as intraperitoneal administration of hMSCs also attenuated LPS-induced inflammation in the lung. Microarray analysis revealed significant induction of TNF--induced protein 6 (TSG-6) expression by hMSCs 12 hr after OA delivery to LPS-exposed lungs. Knockdown of TSG-6 expression in hMSCs by RNA interference abrogated most of their anti-inflammatory effects. In addition, intra-pulmonary delivery of recombinant human TSG-6 reduced LPS-induced inflammation in the lung. These results show that hMSCs recapitulate the observed beneficial effects of rodent MSCs in animal models of ALI and suggest that the anti-inflammatory properties of hMSCs in the lung are explained, at least in part, by activation of hMSCs to secrete TSG-6.
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Sex, Specimen part, Treatment
View SamplesQuantitative assays for human DNA and mRNA were used to examine the paradox that intravenously (IV) infused human multipotent stromal cells (hMSCs) can enhance tissue repair without significant engraftment. After 2 X 106 hMSCs were IV infused into mice, most of the cells were trapped as emboli in lung. The cells in lung disappeared with a half-life of about 24 hr but < 1,000 cells appeared in 6 other tissues. The hMSCs in lung up-regulated expression of multiple genes with a large increase in the anti-inflammatory protein TSG-6. After myocardial infarction, IV hMSCs but not hMSCs transduced with TSG-6 siRNA decreased inflammatory responses, reduced infarct size, and improved cardiac function. IV administration of recombinant TSG-6 also reduced inflammatory responses and reduced infarct size. The results suggest improvements in animal models and patients after IV infusions of MSCs are at least in part explained by activation of MSCs to secrete TSG-6.
Intravenous hMSCs improve myocardial infarction in mice because cells embolized in lung are activated to secrete the anti-inflammatory protein TSG-6.
Specimen part, Disease
View SamplesCytosine methylation is an epigenetic mark usually associated with gene repression. Despite a requirement for de novo DNA methylation for differentiation of embryonic stem cells, its role in somatic stem cells is unknown. Using conditional ablation, we show that loss of either, or both, Dnmt3a or Dnmt3b, progressively impedes hematopoietic stem cell (HSC) differentiation during serial in vivo passage. Concomitantly, HSC self-renewal is immensely augmented in absence of either Dnmt3, particularly Dnmt3a. Dnmt3-KO HSCs show upregulation of HSC multipotency genes and downregulation of early differentiation factors, and the differentiated progeny of Dnmt3-KO HSCs exhibit hypomethylation and incomplete repression of HSC-specific genes. HSCs lacking Dnmt3a manifest hyper-methylation of CpG islands and hypo-methylation of genes which are highly correlated with human hematologic malignancies. These data establish that aberrant DNA methylation has direct pathologic consequences for somatic stem cell development, leading to inefficient differentiation and maintenance of a self-renewal program.
Dnmt3a is essential for hematopoietic stem cell differentiation.
Sex, Specimen part
View SamplesAntagonism of microRNA-122 in mice by systemically administered LNA-antimiR leads to up-regulation of a large set of predicted target mRNAs in the liver
Antagonism of microRNA-122 in mice by systemically administered LNA-antimiR leads to up-regulation of a large set of predicted target mRNAs in the liver.
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View SamplesSky1 is a Saccharomyces cerevisiae rich serine-arginine (SR) protein-specific kinase and its enzymatic activity is essential in the cytotoxicity caused by cisplatin, although the molecular mechanisms supporting this function are not understood. We present a transcriptome analysis discriminating between RNA changes induced by cisplatin which are dependent or independent of the Sky1 function.
Sky1 regulates the expression of sulfur metabolism genes in response to cisplatin.
Genetic information
View SamplesSky1 is a Saccharomyces cerevisiae rich serine-arginine (SR) protein-specific kinase and its enzymatic activity is essential in the cytotoxicity caused by cisplatin, although the molecular mechanisms supporting this function are not understood. We present a transcriptome analysis discriminating between RNA changes induced by cisplatin which are dependent or independent of the Sky1 function.
Sky1 regulates the expression of sulfur metabolism genes in response to cisplatin.
Genetic information
View SamplesSky1 is a Saccharomyces cerevisiae rich serine-arginine (SR) protein-specific kinase and its enzymatic activity is essential in the cytotoxicity caused by cisplatin, although the molecular mechanisms supporting this function are not understood. We present a transcriptome analysis discriminating between RNA changes induced by cisplatin which are dependent or independent of the Sky1 function.
Sky1 regulates the expression of sulfur metabolism genes in response to cisplatin.
Genetic information
View SamplesSky1 is a Saccharomyces cerevisiae rich serine-arginine (SR) protein-specific kinase and its enzymatic activity is essential in the cytotoxicity caused by cisplatin, although the molecular mechanisms supporting this function are not understood. We present a transcriptome analysis discriminating between RNA changes induced by cisplatin which are dependent or independent of the Sky1 function.
Sky1 regulates the expression of sulfur metabolism genes in response to cisplatin.
Genetic information
View SamplesSky1 is a Saccharomyces cerevisiae rich serine-arginine (SR) protein-specific kinase and its enzymatic activity is essential in the cytotoxicity caused by cisplatin, although the molecular mechanisms supporting this function are not understood. We present a transcriptome analysis discriminating between RNA changes induced by cisplatin which are dependent or independent of the Sky1 function.
Sky1 regulates the expression of sulfur metabolism genes in response to cisplatin.
Genetic information
View SamplesSky1 is a Saccharomyces cerevisiae rich serine-arginine (SR) protein-specific kinase and its enzymatic activity is essential in the cytotoxicity caused by cisplatin, although the molecular mechanisms supporting this function are not understood. We present a transcriptome analysis discriminating between RNA changes induced by cisplatin which are dependent or independent of the Sky1 function.
Sky1 regulates the expression of sulfur metabolism genes in response to cisplatin.
Genetic information
View Samples