Project description:Fibrillins are the major components of microfibrils in the extracellular matrix of elastic and non-elastic tissues. Fibrillin-1 contains one evolutionarily conserved Arg-Gly-Asp (RGD) sequence which mediates cell-matrix interactions through cell-surface integrins. Mutations in close vicinity to the RDG sequence lead to heritable disorders, including Marfan syndrome and stiff skin syndrome. Two recombinant fibrillin-1 fragments were produced, one wild-type RGD-containing fragment and one fragment containing a mutant RGA sequence, which has been previously shown to abolish interactions with integrins. To determine the differential regulation of signaling pathways, microarray analysis of mRNA expression was conducted using Affymetrix Human Gene 2.0 ST chips. The mRNA expression levels were compared after 24 hours of interaction between human skin fibroblasts (HSFs) and the RGD- and RGA-containing fibrillin-1 fragments.
Project description:Fibrillins are the major components of microfibrils in the extracellular matrix of elastic and non-elastic tissues. Fibrillin-1 contains one evolutionarily conserved Arg-Gly-Asp (RGD) sequence which mediates cell-matrix interactions through cell-surface integrins. Mutations in close vicinity to the RDG sequence lead to heritable disorders, including Marfan syndrome and stiff skin syndrome. Two recombinant fibrillin-1 fragments were produced, one wild-type RGD-containing fragment and one fragment containing a mutant RGA sequence, which has been previously shown to abolish interactions with integrins. To determine the differential regulation of signaling pathways, microarray analysis of microRNA expression was conducted using Affymetrix miRNA3.0 chips. The microRNA expression levels were compared after 24 hours of interaction between human skin fibroblasts (HSFs) and the RGD- and RGA-containing fibrillin-1 fragments.
Project description:Hypoxia is the most prominent feature in human solid tumors and induces activation of hypoxia-inducible factors and their downstream genes to promote cancer progression. However, whether and how hypoxia regulates overall mRNA homeostasis is unclear. Here we show that hypoxia inhibits global-mRNA decay in cancer cells. Mechanistically, hypoxia induces the interaction of AGO2 with HOIL-1L/HOIP, two crucial components of a linear ubiquitin chain assembly complex, which co-localizes with miRNA-induced silencing complex and in turn catalyzes AGO2 occurring Met1-linked linear ubiquitination (M1-Ubi). A series of biochemical experiments reveal that M1-Ubi of AGO2 restrains miRNA-mediated gene silencing. Moreover, combination analyses of the AGO2-associated mRNA transcriptome by RIP-Seq and the mRNA transcriptome by RNA-Seq confirm that AGO2 M1-Ubi interferes miRNA-targeted mRNA recruiting to AGO2, and thereby facilitates accumulation of global mRNAs. By this mechanism, short-term hypoxia may protect overall mRNAs and enhances stress tolerance, whereas long-term hypoxia in tumor cells results in seriously changing the entire gene expression profile to drive cell malignant evolution.
Project description:As the fetal heart develops, cardiomyocyte proliferation potential decreases while fatty acid oxidative capacity increases, a highly regulated transition known as cardiac maturation. Small noncoding RNAs, such as microRNAs (miRNAs), contribute to the establishment and control of tissue-specific transcriptional programs. However, small RNA expression dynamics and genome wide miRNA regulatory networks controlling maturation of the human fetal heart remain poorly understood. Transcriptome profiling of small RNAs revealed the temporal expression patterns of miRNA, piRNA, circRNA, snoRNA, snRNA and tRNA in the developing human heart between 8 and 19 weeks of gestation. Our analysis revealed that miRNAs were the most dynamically expressed small RNA species throughout mid-gestation. Cross-referencing differentially expressed miRNAs and mRNAs predicted 6,200 mRNA targets, 2134 of which were upregulated and 4066 downregulated as gestation progresses. Moreover, we found that downregulated targets of upregulated miRNAs predominantly control cell cycle progression, while upregulated targets of downregulated miRNAs are linked to energy sensing and oxidative metabolism. Furthermore, integration of miRNA and mRNA profiles with proteomes and reporter metabolites revealed that proteins encoded in mRNA targets, and their associated metabolites, mediate fatty acid oxidation and are enriched as the heart develops.This study revealed the small RNAome of the maturing human fetal heart. Furthermore, our findings suggest that coordinated activation and repression of miRNA expression throughout mid-gestation is essential to establish a dynamic miRNA-mRNA-protein network that decreases cardiomyocyte proliferation potential while increasing the oxidative capacity of the maturing human fetal heart.
Project description:Glioblastoma multiforme (GBM) is the most common and aggressive type of malignant glioma. Oncolytic adenoviruses are being modified to exploit the aberrant expression of proteins in tumor cells to enhance tumor tropism and glioma-selective replication. E1A mutant adenovirus Delta-24-RGD has shown favorable toxicity profile and remarkable efficacy in a first-in-human phase I clinical trial. However, the comprehensive modulation of glioma metabolism in response to Delta-24-RGD infection is poorly understood. Integrating mass spectrometry based-quantitative proteomics, physical and functional interaction data, and biochemical approaches, we conducted a cell-wide study of intracellular and secreted glioma proteomes at late stage of Delta-24-RGD infection, when prominent autophagy has been described.
Project description:Glioblastoma multiforme (GBM) is the most common and aggressive type of malignant glioma. Oncolytic adenoviruses are being modified to exploit the aberrant expression of proteins in tumor cells to enhance tumor tropism and glioma-selective replication. E1A mutant adenovirus Delta-24-RGD has shown favorable toxicity profile and remarkable efficacy in a first-in-human phase I clinical trial. However, the comprehensive modulation of glioma metabolism in response to Delta-24-RGD infection is poorly understood. Integrating mass spectrometry based-quantitative proteomics, physical and functional interaction data, and biochemical approaches, we conducted a cell-wide study of intracellular and secreted glioma proteomes at late stage of Delta-24-RGD infection, when prominent autophagy has been described.