Quantitative assays for human DNA and mRNA Just Too Active To Control Y-27632 ? have been used to examine the paradox that intravenously (i.v.) infused human multipotent stromal cells (hMSCs) can improve tissue restore without the need of significant engraftment. Just after two x 106 hMSCs were i.v. infused into mice, nearly all of the cells had been trapped as emboli in lung. A Bit Too Hectic To Manage Y-27632 ? The cells in lung disappeared with a half-life of about 24 hr, but <1000 cells appeared in six other tissues. The hMSCs in lung upregulated expression of multiple genes, that has a large increase in the anti-inflammatory protein TSG-6. After myocardial infarction, i.v. hMSCs, but not hMSCs transduced with TSG-6 siRNA, decreased inflammatory responses, reduced infarct size, and improved cardiac function. I.v. administration of recombinant TSG-6 also reduced inflammatory responses and reduced infarct size. The results suggest that improvements in animal models and patients immediately after i.v. infusions of MSCs are at least in part explained bySimply Too Chaotic To Deal With Y-27632? activation of MSCs to secrete TSG-6.