Search results for "messenger"
showing 10 items of 1493 documents
Liver specific overexpression of platelet-derived growth factor-B accelerates liver cancer development in chemically induced liver carcinogenesis
2010
A genetic basis of hepatocellular carcinoma (HCC) has been well-established and major signaling pathways, such as p53, Wnt-signaling, transforming growth factor-β (TGF-β) and Ras pathways, have been identified to be essential to HCC development. Lately, the family of platelet-derived growth factors (PDGFs) has shifted to the center of interest. We have reported on spontaneously developing liver fibrosis in PDGF-B transgenic mice. Since HCC rarely occurs in healthy liver, but dramatically increases at the cirrhosis stage of which liver fibrosis is a preliminary stage, we investigated liver cancer development in chemically induced liver carcinogenesis in these mice. HCC induction was performe…
Sonic hedgehog promotes angiogenesis and osteogenesis in a coculture system consisting of primary osteoblasts and outgrowth endothelial cells.
2009
A number of previous studies documented the angiogenic potential of outgrowth endothelial cells in vitro and in vivo and provided evidence that therapeutic success could depend on coculture or coimplantation strategies. Thus, deeper insight into the molecular mechanisms underlying this pro-angiogenic effect of cocultures might provide new translational options for tissue engineering and regenerative medicine. One promising signaling pathway in bone repair involved in neoangiogenesis and bone formation is the sonic hedgehog (Shh) pathway. In this article, we focus on the effect of Shh on the formation of microvessel-like structures and osteoblastic differentiation in cocultures of primary os…
Protein kinase C promotes angiogenic activity of human endothelial cells via induction of vascular endothelial growth factor
2008
Aims Protein kinase C (PKC) plays an important role in the regulation of angiogenesis. However, downstream targets of PKC in endothelial cells are poorly defined. Methods and results mRNA expression of vascular endothelial growth factor (VEGF) was analysed by quantitative real-time RT-PCR in human umbilical vein endothelial cells (HUVEC) and HUVEC-derived EA.hy 926 cells. siRNA was used to knockdown PKC isoforms and VEGF. Matrigel tube formation assay was used to analyse the angiogenic activity of endothelial cells. Phorbol-12-myristate-13-acetate (PMA) enhanced the ability of HUVEC to organize into tubular networks when plated on Matrigel, a phenomenon that could be prevented by PKC inhibi…
Enzymatically modified nonoxidized low-density lipoprotein induces interleukin-8 in human endothelial cells: role of free fatty acids.
2002
Background— Treatment of low-density lipoprotein (LDL) with a protease and cholesterolesterase transforms the lipoprotein to an entity that resembles lipoprotein particles in atherosclerotic lesions, which have a high content of free cholesterol, reflecting extensive de-esterification in the intima. Because de-esterification would occur beneath the endothelium, we examined the effects of enzymatically modified LDL (E-LDL) on cultured endothelial cells. Methods and Results— Incubation of endothelial cells with E-LDL provoked selective accumulation of interleukin (IL)-8 mRNA and production of the cytokine. Chemical analyses and depletion experiments indicated that the effect was caused by th…
Lysozyme gene expression and hemocyte behaviour in the Mediterranean mussel, Mytilus galloprovincialis, after injection of various bacteria or temper…
2008
The aim of the present study was to evaluate the expression of the Mytilus galloprovincialis lysozyme gene in different in vivo stress situations, including injection of bacteria Vibrio splendidus LGP32, Vibrio anguillarum or Micrococcus lysodeikticus, as well as heat shock at 30 C and cold stress at 5 C. Injection of V. splendidus LGP32 resulted in: (i) a general down-regulation of lysozyme gene expression, as quantified by Q-PCR; (ii) reduction in the number of circulating hemocytes; (iii) decrease in the percentage of circulating hemocytes expressing lysozyme mRNA which was now restricted to only small cells, as observed by ISH; and (iv) accumulation of hemocytes expressing lysozyme in t…
Specific expression of antimicrobial peptide and HSP70 genes in response to heat-shock and several bacterial challenges in mussels
2007
Abstract Defensin, mytilin and myticin are antimicrobial peptides (AMP) involved in mussel innate immunity. Their in vitro antibacterial activity is different according to the targeted bacterial species. To determine if this specificity is correlated to different regulations of gene expressions, adult mussels were challenged in vivo with either Vibrio splendidus LGP32, Vibrio anguillarum , Micrococcus lysodeikticus or by heat shock. RNAs were isolated from circulating hemocytes and AMP mRNAs were quantified by Q-PCR using 28S rRNA as housekeeping gene. In addition, HSP70 gene expression was also quantified as representing non-specific response to stress. In naive mussels, the three AMP mRNA…
Transcriptional Upregulation of Genes Related to Virulence Activation in Entamoeba histolytica
2007
Background To understand the molecular basis of virulence variability in Entamoeba histolytica , this study presents results about differential gene expression induced by E. histolytica trophozoites in liver of hamsters in order to produce experimental amebic liver abscess (ALA) and consequently reactivate its virulence. Methods Amebic cultures were studied before (BALA) and after (AALA) inoculation in hamster peritoneal cavity. Markers of pathogenicity such as the rate of erythrophagocytosis, hemolytic activity, and cytotoxic effects on MDCK cell monolayers were evaluated in order to correlate these phenotypic characteristics to differential gene expression between virulent and non-virulen…
Sec61alpha and TRAM are Sequentially Adjacent to a Nascent Viral Membrane Protein during its ER Integration
2007
Co-translational integration of a nascent viral membrane protein into the endoplasmic reticulum membrane takes place via the translocon. We have been studying the early stages of the integration of a double-spanning plant viral movement protein to gain insights into how viral membrane proteins are transferred from the hydrophilic interior of the translocon into the hydrophobic environment of the bilayer, where the transmembrane (TM) segments of the viral proteins can diffuse freely. Photocrosslinking experiments reveal that this integration involves the sequential passage of the TM segments past Sec61alpha and translocating chain-associating membrane protein (TRAM). Each TM segment is first…
Vitamin A deficiency alters rat lung alveolar basement membrane: reversibility by retinoic acid.
2010
Vitamin A is essential for lung development and pulmonary cell differentiation and its deficiency results in alterations of lung structure and function. Basement membranes (BMs) are also involved in those processes, and retinoic acid, the main biologically active form of vitamin A, influences the expression of extracellular matrix macromolecules. Therefore, we have analyzed the ultrastructure and collagen content of lung alveolar BM in growing rats deficient in vitamin A and the recovering effect of all-trans retinoic acid. Male weanling pups were fed a retinol-adequate or -deficient diet until they were 60 days old. A group of vitamin A-deficient pups were recovered by daily intraperitonea…
Vitamin A deficiency alters the structure and collagen IV composition of rat renal basement membranes.
2005
Retinoids can modulate the expression of extracellular matrix (ECM) proteins with variable results depending on other contributing factors. Because changes in these proteins may alter the composition and impair the function of specialized ECM structures such as basement membranes (BMs), we studied the effects of vitamin A deficiency on renal BMs during the growing period. Newborn male rats were fed a vitamin A-deficient (VAD) diet for 50 d. The ultrastructure of renal BMs was analyzed by electron microscopy. Total collagen IV, the different alpha(IV) chains, matrix degrading metalloproteinases (MMP), and tissue inhibitors of metalloproteinases (TIMP) were quantified by immunocytochemistry a…