Development of spider veins is caused by the remodeling of veins located in the upper dermis and promoted by risk factors such as obesity or pregnancy that chronically increase venous pressure. We have repeatedly shown that the pressure-induced increase in biomechanical wall stress is sufficient to evoke the formation of enlarged corkscrew-like superficial veins in mice. Subsequent experimental approaches revealed that interference with endothelial- and/or smooth muscle cell activation counteracts this remodeling process. Here, we investigate whether the herbal agent glycyrrhetinic acid (GA) is a suitable candidate for that purpose given its anti-proliferative as well as anti-oxidative properties.
Glycyrrhetinic Acid Antagonizes Pressure-Induced Venous Remodeling in Mice.
Specimen part, SubjectView Samples
Chronic biomechanical stress elicits remodeling of the arterial wall and causes detrimental arterial stenosis and stiffening. In this context, molecular determinants controlling proliferation and stress responses of vascular smooth muscle cells (VSMCs) have been insufficiently studied. We identified the transcription factor nuclear factor of activated T-cells 5 (NFAT5) as crucial regulatory element of mechanical stress responses of VSMCs. The relevance of this observation for biomechanically induced arterial remodeling was investigated in mice upon SMC-specific knockdown of NFAT5. While blood pressure levels, vascular architecture and flow-induced collateral growth were not affected in these mice, both hypertension-mediated arterial thickening and muscularization of pulmonary arteries during pulmonary artery hypertension (PAH) were impaired. In all models, a decrease in VSMC proliferation was observed indicating that NFAT5 controls activation of VSMCs in the remodeling arterial wall. Mechanistically, mechanoactivation of VSMCs promotes nuclear translocation NFTA5c upon its phosphorylation at Y143 and dephosphorylation at S1197. As evidenced by transcriptome studies, loss of NFAT5 in mechanoactivated VSMCs impairs expression of gene products controlling cell cycle and transcription/translation. These findings identify NFAT5 as molecular determinant of VSMC responses to biomechanical stress and arterial thickening.
NFAT5 Isoform C Controls Biomechanical Stress Responses of Vascular Smooth Muscle Cells.
To study the impact of the transcription factor NFAT5 on the vascular smooth muscle cell (VSMC) transcriptome, genetic ablation of floxed nfat5 in mouse aortic smooth muscle cells was achieved by transducing them with an adenoviral vector to express Cre-recombinase (Ad-Cre) under control of a CMV promoter.
Genetic ablation of NFAT5/TonEBP in smooth muscle cells impairs flow- and pressure-induced arterial remodeling in mice.
Specimen partView Samples
Drought tolerance is a key trait for increasing and stabilizing barley productivity in dry areas worldwide. Identification of the genes responsible for drought tolerance in barley (Hordeum vulgare L.) will facilitate understanding of the molecular mechanisms of drought tolerance, and also genetic improvement of barley through marker-assisted selection or gene transformation. To monitor the changes in gene expression at transcription levels in barley leaves during the reproductive stage under drought conditions, the 22K Affymetrix Barley 1 microarray was used to screen two drought-tolerant barley genotypes, Martin and Hordeum spontaneum 41-1 (HS41-1), and one drought-sensitive genotype Moroc9-75. Seventeen genes were expressed exclusively in the two drought-tolerant genotypes under drought stress, and their encoded proteins may play significant roles in enhancing drought tolerance through controlling stomatal closure via carbon metabolism (NADP malic enzyme (NADP-ME) and pyruvate dehydrogenase (PDH), synthesizing the osmoprotectant glycine-betaine (C-4 sterol methyl oxidase (CSMO), generating protectants against reactive-oxygen-species scavenging (aldehyde dehydrogenase (ALDH), ascorbate-dependant oxidoreductase (ADOR), and stabilizing membranes and proteins (heat-shock protein 17.8 (HSP17.8) and dehydrin 3 (DHN3). Moreover, 17 genes were abundantly expressed in Martin and HS41-1 compared with Moroc9-75 under both drought and control conditions. These genes were likely constitutively expressed in drought-tolerant genotypes. Among them, 7 known annotated genes might enhance drought tolerance through signaling (such as calcium-dependent protein kinase (CDPK) and membrane steroid binding protein (MSBP), anti-senescence (G2 pea dark accumulated protein GDA2) and detoxification (glutathione S-transferase (GST) pathways. In addition, 18 genes, including those encoding l-pyrroline-5-carboxylate synthetase (P5CS), protein phosphatase 2C-like protein (PP2C) and several chaperones, were differentially expressed in all genotypes under drought; thus, they were more likely general drought-responsive genes in barley. These results could provide new insights into further understanding of drought-tolerance mechanisms in barley.
Differentially expressed genes between drought-tolerant and drought-sensitive barley genotypes in response to drought stress during the reproductive stage.
Specimen part, TreatmentView Samples
The activation of vascular smooth muscle cells (VSMCs) during hypertension-induced arterial remodeling processes relies on a change of the gene expression program, i.e., up-regulation of genes to induce migration, proliferation and matrix degradation/synthesis. At the same time, genes controlling the quiescent, contractile VSMC phenotype are down-regulated. We used microarrays to detail the global program of gene expression underlying hypertension-induced vascular remodeling in the presence and absence of regulator of G-protein signaling 5 (RGS5) and identified distinct classes of down-regulated genes during vascular remodeling when RGS5 was not present.
Hypertension-evoked RhoA activity in vascular smooth muscle cells requires RGS5.
Sex, Specimen part, TreatmentView Samples
Vascular smooth muscle cells (VSMCs) respond to biomechanical stretch with specific changes in gene expression which govern the phenotype of these cells. The mechanotransducer zyxin is a
Loss of the mechanotransducer zyxin promotes a synthetic phenotype of vascular smooth muscle cells.
Specimen part, TreatmentView Samples
Identifying the genes underlying quantitative trait loci (QTL) for disease has proven difficult, mainly due to the low resolution of the approach and the complex genetics involved. However, recent advances in bioinformatics and the availability of genetic resources now make it possible to narrow the genetic intervals and test candidate genes. In addition to identifying the causative genes, defining the pathways that are affected by these QTL is of major importance as it can give us insight into the disease process and provide evidence to support candidate genes. In this study we mapped three significant and one suggestive QTL on Chromosomes (Chrs) 1, 4, 15, and 17, respectively, for increased albumin excretion (measured as albumin-to-creatinine ratio) in a cross between the MRL/MpJ and SM/J mouse inbred strains. By combining data from several sources and by utilizing gene expression data, we identified Tlr12 as a likely candidate for the Chr 4 QTL. Through the mapping of 33,881 transcripts measured by microarray on kidney RNA from each of the 173 male F2 animals, we identified several downstream pathways associated with these QTL. Among these were the glycan degradation, leukocyte migration, and antigen presenting pathways. We demonstrate that by combining data from multiple sources, we can identify not only genes that are likely to be causal candidates for QTL, but also the pathways through which these genes act to alter phenotypes. This combined approach provides valuable insights into the causes and consequences of renal disease.
Uncovering genes and regulatory pathways related to urinary albumin excretion.
Sex, AgeView Samples
In somatic cells elevated temperature induces activation of the heat shock transcription factor 1 (HSF1) what leads to heat shock proteins synthesis and cytoprotection. However, in the male germ cells (spermatocytes) upon HSF1 activation, caspase-3 dependent apoptosis is induced and spermatogenic cells are actively eliminated.
Impact of heat shock transcription factor 1 on global gene expression profiles in cells which induce either cytoprotective or pro-apoptotic response following hyperthermia.
Sex, Specimen partView Samples
Bulk RNA-seq to profile of c-kit+ cardiac interstitial cells, comparing the transcriptomes of Pim-1 enhanced cardiac progenitor cells and transfection control Overall design: Transcriptional profiling of Pim-1 enhanced human derived cardiac interstitial cells by bulk RNA-Seq
Safety profiling of genetically engineered Pim-1 kinase overexpression for oncogenicity risk in human c-kit+ cardiac interstitial cells.
Specimen part, SubjectView Samples
Nearly all colorectal cancers have dysregulated Wnt signalling, predominantly through the mutation of the Apc (Adenomatous Polyposis Coli) gene. Therefore it is of vital importance to elucidate the key Wnt target genes in intestinal cells in vivo. We have used a novel inducible cre-lox based murine system (designated ApcFlox) to investigate the consequences of perturbation of Wnt signalling following inactivation of Apc in vivo within 100% of the intestinal epithelium. We have employed microarray analysis at 3 time points within our ApcFlox system (Day 3 prior to the onset of phenotype, day 4 the establishment of the phenotype and day 5 gross phenotype of altered proliferation, differentiation and migration) and from adenomas arising in the ApcMin/+ background allowing us characterise Wnt/beta-catenin target genes based on their expression profiles during different stages of intestinal tumourigenesis. Furthermore, we have employed microarray analysis using livers from our ApcFlox system and have demonstrated that there is very little overlap in the Wnt target genes induced by Apc loss in the liver and the intestine. More importantly, we have been able to determine a novel set of putative Wnt/beta-catenin target genes which are upregulated at both early and late stages of tumourigenesis in the intestine and may represent novel therapeutic targets in colon cancer.
Hunk/Mak-v is a negative regulator of intestinal cell proliferation.
Specimen partView Samples