954 resultados para Fibroblast viability


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This work was motivated by the incomplete characterization of the role of vascular endothelial growth factor-A (VEGF-A) in the stressed heart in consideration of upcoming cancer treatment options challenging the natural VEGF balance in the myocardium. We tested, if the cytotoxic cancer therapy doxorubicin (Doxo) or the anti-angiogenic therapy sunitinib alters viability and VEGF signaling in primary cardiac microvascular endothelial cells (CMEC) and adult rat ventricular myocytes (ARVM). ARVM were isolated and cultured in serum-free medium. CMEC were isolated from the left ventricle and used in the second passage. Viability was measured by LDH-release and by MTT-assay, cellular respiration by high-resolution oxymetry. VEGF-A release was measured using a rat specific VEGF-A ELISA-kit. CMEC were characterized by marker proteins including CD31, von Willebrand factor, smooth muscle actin and desmin. Both Doxo and sunitinib led to a dose-dependent reduction of cell viability. Sunitinib treatment caused a significant reduction of complex I and II-dependent respiration in cardiomyocytes and the loss of mitochondrial membrane potential in CMEC. Endothelial cells up-regulated VEGF-A release after peroxide or Doxo treatment. Doxo induced HIF-1α stabilization and upregulation at clinically relevant concentrations of the cancer therapy. VEGF-A release was abrogated by the inhibition of the Erk1/2 or the MAPKp38 pathway. ARVM did not answer to Doxo-induced stress conditions by the release of VEGF-A as observed in CMEC. VEGF receptor 2 amounts were reduced by Doxo and by sunitinib in a dose-dependent manner in both CMEC and ARVM. In conclusion, these data suggest that cancer therapy with anthracyclines modulates VEGF-A release and its cellular receptors in CMEC and ARVM, and therefore alters paracrine signaling in the myocardium.

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Perinatal care of pregnant women at high risk for preterm delivery and of preterm infants born at the limit of viability (22-26 completed weeks of gestation) requires a multidisciplinary approach by an experienced perinatal team. Limited precision in the determination of both gestational age and foetal weight, as well as biological variability may significantly affect the course of action chosen in individual cases. The decisions that must be taken with the pregnant women and on behalf of the preterm infant in this context are complex and have far-reaching consequences. When counselling pregnant women and their partners, neonatologists and obstetricians should provide them with comprehensive information in a sensitive and supportive way to build a basis of trust. The decisions are developed in a continuing dialogue between all parties involved (physicians, midwives, nursing staff and parents) with the principal aim to find solutions that are in the infant's and pregnant woman's best interest. Knowledge of current gestational age-specific mortality and morbidity rates and how they are modified by prenatally known prognostic factors (estimated foetal weight, sex, exposure or nonexposure to antenatal corticosteroids, single or multiple births) as well as the application of accepted ethical principles form the basis for responsible decision-making. Communication between all parties involved plays a central role. The members of the interdisciplinary working group suggest that the care of preterm infants with a gestational age between 22 0/7 and 23 6/7 weeks should generally be limited to palliative care. Obstetric interventions for foetal indications such as Caesarean section delivery are usually not indicated. In selected cases, for example, after 23 weeks of pregnancy have been completed and several of the above mentioned prenatally known prognostic factors are favourable or well informed parents insist on the initiation of life-sustaining therapies, active obstetric interventions for foetal indications and provisional intensive care of the neonate may be reasonable. In preterm infants with a gestational age between 24 0/7 and 24 6/7 weeks, it can be difficult to determine whether the burden of obstetric interventions and neonatal intensive care is justified given the limited chances of success of such a therapy. In such cases, the individual constellation of prenatally known factors which impact on prognosis can be helpful in the decision making process with the parents. In preterm infants with a gestational age between 25 0/7 and 25 6/7 weeks, foetal surveillance, obstetric interventions for foetal indications and neonatal intensive care measures are generally indicated. However, if several prenatally known prognostic factors are unfavourable and the parents agree, primary non-intervention and neonatal palliative care can be considered. All pregnant women with threatening preterm delivery or premature rupture of membranes at the limit of viability must be transferred to a perinatal centre with a level III neonatal intensive care unit no later than 23 0/7 weeks of gestation, unless emergency delivery is indicated. An experienced neonatology team should be involved in all deliveries that take place after 23 0/7 weeks of gestation to help to decide together with the parents if the initiation of intensive care measures appears to be appropriate or if preference should be given to palliative care (i.e., primary non-intervention). In doubtful situations, it can be reasonable to initiate intensive care and to admit the preterm infant to a neonatal intensive care unit (i.e., provisional intensive care). The infant's clinical evolution and additional discussions with the parents will help to clarify whether the life-sustaining therapies should be continued or withdrawn. Life support is continued as long as there is reasonable hope for survival and the infant's burden of intensive care is acceptable. If, on the other hand, the health car...

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The impact of di-cationic pentamidine-analogues against Toxoplama gondii (Rh- and Me49-background) was investigated. The 72 h-growth assays showed that the arylimidamide DB750 inhibited the proliferation of tachyzoites of T. gondii Rh and T. gondii Me49 with an IC(50) of 0.11 and 0.13 muM, respectively. Pre-incubation of fibroblast monolayers with 1 muM DB750 for 12 h and subsequent culture in the absence of the drug also resulted in a pronounced inhibiton of parasite proliferation. However, upon 5-6 days of drug exposure, T. gondii tachyzoites adapted to the compound and resumed proliferation up to a concentration of 1.2 muM. Out of a set of 32 di-cationic compounds screened for in vitro activity against T. gondii, the arylimidamide DB745, exhibiting an IC(50) of 0.03 muM and favourable selective toxicity was chosen for further studies. DB745 also inhibited the proliferation of DB750-adapted T. gondii (IC(50)=0.07 muM). In contrast to DB750, DB745 also had a profound negative impact on extracellular non-adapted T. gondii tachyzoites, but not on DB750-adapted T. gondii. Adaptation of T. gondii to DB745 (up to a concentration of 0.46 muM) was much more difficult to achieve and feasible only over a period of 110 days. In cultures infected with DB750-adapted T. gondii seemingly intact parasites could occasionally be detected by TEM. This illustrates the astonishing capacity of T. gondii tachyzoites to adapt to environmental changes, at least under in vitro conditions, and suggests that DB745 could be an interesting drug candidate for further assessments in appropriate in vivo models.

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Chemotherapeutic drug resistance is one of the major causes for treatment failure in high-risk neuroblastoma (NB), the most common extra cranial solid tumor in children. Poor prognosis is typically associated with MYCN amplification. Here, we utilized a loss-of-function kinome-wide RNA interference screen to identify genes that cause cisplatin sensitization. We identified fibroblast growth factor receptor 2 (FGFR2) as an important determinant of cisplatin resistance. Pharmacological inhibition of FGFR2 confirmed the importance of this kinase in NB chemoresistance. Silencing of FGFR2 sensitized NB cells to cisplatin-induced apoptosis, which was regulated by the downregulation of the anti-apoptotic proteins BCL2 and BCLX(L). Mechanistically, FGFR2 was shown to activate protein kinase C-δ to induce BCL2 expression. FGFR2, as well as the ligand fibroblast growth factor-2, were consistently expressed in primary NB and NB cell lines, indicating the presence of an autocrine loop. Expression analysis revealed that FGFR2 correlates with MYCN amplification and with advanced stage disease, demonstrating the clinical relevance of FGFR2 in NB. These findings suggest a novel role for FGFR2 in chemoresistance and provide a rational to combine pharmacological inhibitors against FGFR2 with chemotherapeutic agents for the treatment of NB.Oncogene advance online publication, 1 October 2012; doi:10.1038/onc.2012.416.

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Background Drugs of plant origin such as Arnica montana, Calendula officinalis or Hypericum perforatum have been frequently used to promote wound healing. While their effect on wound healing using preparations at pharmacological concentrations was supported by several in vitro and clinical studies, investigations of herbal homeopathic remedies on wound healing process are rare. The objective of this study was to investigate the effect of a commercial low potency homeopathic remedy Similasan® Arnica plus Spray on wound closure in a controlled, blind trial in vitro. Methods We investigated the effect of an ethanolic preparation composed of equal parts of Arnica montana 4x, Calendula officinalis 4x, Hypericum perforatum 4x and Symphytum officinale 6x (0712–2), its succussed hydroalcoholic solvent (0712–1) and unsuccussed solvent (0712–3) on NIH 3T3 fibroblasts. Cell viability was determined by WST-1 assay, cell growth using BrdU uptake, cell migration by chemotaxis assay and wound closure by CytoSelect ™Wound Healing Assay Kit which generated a defined “wound field”. All assays were performed in three independent controlled experiments. Results None of the three substances affected cell viability and none showed a stimulating effect on cell proliferation. Preparation (0712–2) exerted a stimulating effect on fibroblast migration (31.9%) vs 14.7% with succussed solvent (0712–1) at 1:100 dilutions (p < 0.001). Unsuccussed solvent (0712–3) had no influence on cell migration (6.3%; p > 0.05). Preparation (0712–2) at a dilution of 1:100 promoted in vitro wound closure by 59.5% and differed significantly (p < 0.001) from succussed solvent (0712–1), which caused 22.1% wound closure. Conclusion Results of this study showed that the low potency homeopathic remedy (0712–2) exerted in vitro wound closure potential in NIH 3T3 fibroblasts. This effect resulted from stimulation of fibroblasts motility rather than of their mitosis.

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FGFRL1 is a novel member of the fibroblast growth factor receptor family that controls the formation of musculoskeletal tissues. Some vertebrates, including man, cow, dog, mouse, rat and chicken, possess a single copy the FGFRL1 gene. Teleostean fish have two copies, fgfrl1a and fgfrl1b, because they have undergone a whole genome duplication. Vertebrates belong to the chordates, a phylum that also includes the subphyla of the cephalochordates (e.g. Branchiostoma floridae) and urochordates (tunicates, e.g. Ciona intestinalis). We therefore investigated whether other chordates might also possess an FGFRL1 related gene. In fact, a homologous gene was found in B. floridae (amphioxus). The corresponding protein showed 60% sequence identity with the human protein and all sequence motifs identified in the vertebrate proteins were also conserved in amphioxus Fgfrl1. In contrast, the genome of the urochordate C. intestinalis and those from more distantly related invertebrates including the insect Drosophila melanogaster and the nematode Caenorhabditis elegans did not appear to contain any related sequences. Thus, the FGFRL1 gene might have evolved just before branching of the vertebrate lineage from the other chordates.

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FGFRL1 is a novel member of the fibroblast growth factor receptor (FGFR) family. To investigate its expression during mammalian embryonic development, we have used the mouse system. Expression of Fgfrl1 is very low in mouse embryos of day 6 but steadily increases until birth. As demonstrated by in situ hybridization of 16-day-old embryos, the Fgfrl1 mRNA occurs in cartilaginous structures such as the primordia of bones and the permanent cartilage of the trachea, the ribs and the nose. In addition, some muscle types, including the muscles of the tongue and the diaphragm, express Fgfrl1 at relatively high level. In contrast, the heart and the skeletal muscles of the limbs, as well as many other organs (brain, lung, liver, kidney, gut) express Fgfrl1 only at basal level. It is conceivable that Fgfrl1 interacts with other Fgfrs, which are expressed in cartilage and muscle, to modulate FGF signaling.

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The present study aimed to search for and characterize parasite molecules, whose expression levels correlate with the viability and growth activity of Echinococcus multilocularis metacestodes. We focused on the expression profiles of 2 parasite-derived genes, 14-3-3 and II/3-10, as putative molecular markers for viability and growth activity of the larval parasite. In experiments in vivo, gene expression levels of 14-3-3 and II/3-10 were relatively quantified by real-time reverse transcription-PCR using a housekeeping gene, beta-actin, as a reference reaction. All three reactions were compared with growth activity of the parasite developing in permissive nu/nu and in non-permissive wild type BALB/c mice. At 2 months p.i., the transcription level of 14-3-3 was significantly higher in parasites actively proliferating in nu/nu mice compared to parasites moderately growing in wild type mice. Immunoblotting experiments confirmed at the protein level that 14-3-3 was over-expressed in parasites derived from nu/nu mice at 2 months p.i. In vitro treatment of E. multilocularis with an anti-echinococcal drug nitazoxanide resulted in a significant decrease of both 14-3-3 and II/3-10 transcription levels found after 8 days of treatment, which correlated with the kinetics of a housekeeping gene, beta-actin. The conclusion is that 14-3-3, combined with II/3-10, exhibits good potential as a molecular marker to assess viability and growth activity of the parasite.

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BACKGROUND: Familial isolated growth hormone deficiency (IGHD) is a disorder with about 5-30% of patients having affected relatives. Among those familial types, IGHD type II is an autosomal dominant form of short stature, associated in some families with mutations that result in missplicing to produce del32-71-GH, a GH peptide which cannot fold properly. The mechanism by which this mutant GH may alter the controlled secretory pathway and therefore suppress the secretion of the normal 22-kDa GH product of the normal allele is not known in detail. Previous studies have shown variance depending on cell type, transfection technique used, as well as on the method of analysis performed. AIM: The aim of our study was to analyse and compare the subcellular distribution/localization of del32-71-GH or wild-type (wt)-GH (22-kDa GH), each stably transfected into AtT-20, a mouse pituitary cell line endogenously producing ACTH, employed as the internal control for secretion assessment. METHODS: Colocalization of wt- and del32-71 mutant GH form was studied by quantitative confocal microscopy analysis. Using the immunofluorescent technique, cells were double stained for GH plus one of the following organelles: endoplasmic reticulum (ER anti-Grp94), Golgi (anti-betaCOP) or secretory granules (anti-Rab3a). In addition, GH secretion and cell viability were analysed in detail. RESULTS/CONCLUSIONS: Our results show that in AtT-20 neuroendocrine cells, in comparison to the wt-GH, the del32-71-GH has a major impact on the secretory pathway not only affecting GH but also other peptides such as ACTH. The del32-71-GH is still present at the secretory vesicles' level, albeit in reduced quantity when compared to wt-GH but, importantly, was secretion-deficient. Furthermore, while focusing on cell viability an additional finding presented that the various splice site mutations, even though leading eventually to the same end product, namely del32-71-GH, have different and specific consequences on cell viability and proliferation rate.