INTRODUCTION. Fixation with formalin, a widely adopted procedure to preserve tissue samples, leads to extensive degradation of nucleic acids and thereby compromises procedures like microarray-based gene expression profiling. We hypothesized that RNA fragmentation is caused by activation of RNAses during the interval between formalin penetration and tissue fixation. To prevent RNAse activation, a series of tissue samples were kept under-vacuum at 4C until fixation and then fixed at 4C, for 24 hours, in formalin followed by 4 hours in ethanol 95%.
Formalin fixation at low temperature better preserves nucleic acid integrity.
Specimen part
View SamplesAdministration of exogenous mesenchymal stem cells (MSCs) has been shown to improve the recovery from acute kidney injury (AKI). It has been suggested that the beneficial effect of MSCs is related to the paracrine release of factors favouring proliferation of intrinsic epithelial cells survived to injury rather than to their trans-differentiation. However the factors involved remain to be determined. In the present study we demonstrated that microvesicles (MVs) derived from human bone marrow MSCs are able to stimulate in vitro proliferation and apoptosis resistance of tubular epithelial cells (TEC). In addition, MVs were found to accelerate in vivo the morphological and functional recovery of glycerol induced AKI in SCID mice by inducing TEC proliferation. The effect of MVs on the recovery of AKI was comparable to that of human MSC treatment. In vitro we found that the CD44 and beta1-integrin-dependent incorporation of MVs in TEC was required for their biological action. However, despite their internalization, RNase-treated MVs failed to induce in vitro apoptosis resistance and TEC proliferation, and in vivo recovery from AKI, suggesting an RNA-dependent biological effect. Microarray analysis and quantitative RT-PCR of MV-RNA extract indicated that MVs were shuttling a specific subset of cellular mRNA, such as mRNA associated with the mesenchymal differentiative phenotype and with several cell functions involved in the control of transcription, proliferation, apoptosis and cell immune regulation. These results suggest that MVs derived from MSCs may activate a proliferative program in TEC survived to injury in AKI by an horizontal transfer of mRNA.
Mesenchymal stem cell-derived microvesicles protect against acute tubular injury.
No sample metadata fields
View SamplesmRNA present in EPC derived microvescicles were detected using a RNA quantity curve, in order to evaluate if these vescicles were shuttling a specific subset of mRNAs
Endothelial progenitor cell derived microvesicles activate an angiogenic program in endothelial cells by a horizontal transfer of mRNA.
No sample metadata fields
View SamplesSeveral studies indicate that adult stem cells may improve the recovery from acute tissue injury. It has been suggested that they may contribute to tissue regeneration by the release of paracrine factors promoting proliferation of tissue resident cells. However, the factors involved remain unknown. In the present study we found that microvesicles (MV) derived from human liver stem cells (HLSC) were able to stimulate in vitro proliferation and apoptosis resistance of human and rat hepatocytes. These effects required internalization of MV in the hepatocytes by an alpha4 integrin-dependent mechanism. However, when treated with RNase, MV despites their internalization were unable to induce hepatocyte proliferation and apoptosis resistance, suggesting an RNA dependent effect. Microarray analysis and quantitative RT-PCR demonstrated that MV were shuttling a specific subset of cellular mRNA, such as mRNA associated in the control of transcription, translation, proliferation and apoptosis. When administered in vivo, MV were found to accelerate the morphological and functional recovery of liver in a model of 70% hepatectomy in rats by inducing an hepatocytes proliferation that was abolished by RNase treatment. Using human AGO2 gene, which is shuttled by MV, as a reporter gene, we found the expression of human AGO2 mRNA and protein in the liver of hepatectomized rats treated with MV. This suggest a translation of the MV shuttled mRNA within hepatocytes of treated rats. Conclusion: these results suggest that MV derived from HLSC may activate a proliferative program in remnant hepatocytes after hepatectomy by a horizontal transfer of specific mRNA subsets.
Human liver stem cell-derived microvesicles accelerate hepatic regeneration in hepatectomized rats.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
VEGF blockade enhances the antitumor effect of BRAFV600E inhibition.
Cell line, Treatment
View SamplesIn this work we investigated the combined effects of the BRAF inhibition and of the VEGF blockade in a preclinical model of melanoma. The purpose of this dataset was to examine the transcriptional responses of a A375 xenograft model to PLX472 and bevacizumab, either as single agents or as combination therapy. We performed species-specific analysis of gene expression to discriminate the effects of the different therapeutic regimens on tumor cells (human) and stromal microenvironment (mouse). Here, Illumina Mouse BeadChips were used to profile the transcriptome after 12 days treatment. We reported that dispensing the dual treatment is more efficient than the single compounds and the occurrence of resistance by modifying the tumor genetic programs regulating myeloid cells recruitment and extracellular matrix remodeling.
VEGF blockade enhances the antitumor effect of BRAFV600E inhibition.
Cell line, Treatment
View SamplesIn this work we investigated the combined effects of the BRAF inhibition and of the VEGF blockade in a preclinical model of melanoma. The purpose of this dataset was to examine the transcriptional responses of a A375 xenograft model to PLX472 and bevacizumab, either as single agents or as combination therapy. We performed species-specific analysis of gene expression to discriminate the effects of the different therapeutic regimens on tumor cells (human) and stromal microenvironment (mouse). Here, Illumina Human BeadChips were used to profile the transcriptome after 12 days treatment. We reported that dispensing the dual treatment is more efficient than the single compounds and the occurrence of resistance by modifying the tumor genetic programs regulating myeloid cells recruitment and extracellular matrix remodeling.
VEGF blockade enhances the antitumor effect of BRAFV600E inhibition.
Cell line, Treatment
View SamplesWe report a time course of RNA-seq data from wild-type embryonic stem cells and embryonic stem cells in which the cardiogenic transcription factors ZNF503, ZEB2 and NKX2-5 are depleted with shRNAs differentiating along the cardiac lineage. Overall design: Biological replicates of RNA-seq data from embryonic stem cells differentiating along the cardiac lineage.
An Orthologous Epigenetic Gene Expression Signature Derived from Differentiating Embryonic Stem Cells Identifies Regulators of Cardiogenesis.
No sample metadata fields
View SamplesTo gain a deep understanding of mRNA turnover dynamics in mammalian cells, we pulse labeled newly synthesized RNA in 3t3 cells for 2 h with 4sU. RNA samples were fractionated into the newly synthesized and pre-existing fractions. Both fractions and the total RNA sample were analyzed by mRNA sequencing. We estimated mRNA half-lives based on the ratios of newly synthesized RNA/total RNA ratio and the preexisting RNA/total RNA.
Global quantification of mammalian gene expression control.
No sample metadata fields
View SamplesThe role of the transcription factor EB (TFEB) in the control of cellular functions, including in vascular bed, is mostly thought to be the regulation of lysosomal biogenesis and autophagic flux. While this is its best-known function, we report here the ability of TFEB to orchestrate a non-canonical program involved in the control of cell-cycle and VEGFR2 pathway in the developing vasculature. In endothelial cells, TFEB deletion halts proliferation by inhibiting the CDK4/Rb pathway, which regulates the cell cycle G1-S transition. In an attempt to overcome this limit, cells compensate by increasing the amount of VEGFR2 on the plasma membrane through a microRNA-mediated mechanism and the control of its membrane trafficking. TFEB transactivates the miR-15a/16-1 cluster, which limits the stability of the VEGFR2 transcript, and negatively modulates the expression of MYO1C, which regulates VEGFR2 delivery to the cell surface. In TFEB knocked-down cells, the reduced and increased amount respectively of miR-15a/16-1 and MYO1C result in the overexpression on plasmamembrane of VEGFR2, which however shows low signaling strength. Using endothelial loss-of-function Tfeb mouse mutants, we present evidence of defects in fetal and newborn mouse vasculature caused by the reduced endothelial proliferation and by the anomalous function of VEGFR2 pathway. Thus, this study revealed a new and unreported function of TFEB that expands its role beyond the regulation of autophagic pathway in the vascular system.
TFEB controls vascular development by regulating the proliferation of endothelial cells.
Cell line
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