1,721,028 research outputs found
The role of caveolin-1 in the regulation of angiogenesis
No full textCaveolin-1 (cav-1) is the principal structural component of caveolae which functions as scaffolding protein for the integration of a variety of signaling pathways. In this study, we show that siRNA-induced cav-1 down regulation in human endothelial cells (EC) increased cell size and provoked cell cycle arrest at G1/S phase transition. In addition, silencing of cav-1 reduced matrix metalloproteinases (MMPs) activity which, in turn, affected cell migration and VEGF-induced tube formation of EC in vitro. These data indicate that proper expression of cav-1 is required for maintaining typical functions of EC such as proliferation and the formation of new blood vessels. In addition, we observed a marked increase of cell size, after cav-1 silencing, which might indicate the involvement of this scaffolding protein in the way by which cells perceive changes in their microenvironment. In conclusion, this study proposes cav-1 as an interesting target molecule for studying cellular mechanisms which occur in physiological as well as pathological conditions such as senescence and tumorigenesis
Quantificazione del DNA con Real-Time PCR e risultati di amplificazione degli short tandem repeats (STRs)
No full textLa determinazione della quantità di DNA presente in un campione forense é fondamentale per la maggior parte delle analisi basate sulla PCR perché, se da un lato una quantità eccessiva di templato può provocare la comparsa di picchi aggiuntivi o fuori scala per la tecnica di misurazione, dall’altro, una scarsa quantità può determinare la comparsa di fenomeni stocastici che inficiano la reazione di PCR nonché la successiva interpretazione dei risultati della tipizzazione.
Nella comune pratica di laboratorio genetico-forense i risultati di quantificazione forniti dalla Real Time PCR (qPCR) assumono il ruolo di “linea di confine” tra la possibilità per un determinato campione di DNA di essere sottoposto o meno alle fasi analitiche successive, sulla base di una quantità di DNA compresa nell’ intervallo ottimale indicato dal manuale d’uso dello specifico kit utilizzato. Tuttavia, alcuni studi hanno dimostrato che è possibile ottenere dei risultati di tipizzazione anche in presenza di una concentrazione di DNA molto bassa o, paradossalmente, pari a zero (Cupples et al. 2009). Indipendentemente dalla quantità di DNA utilizzata per la quantificazione del campione in esame, software specifici spesso sfruttano la curva standard per calcolare valori di concentrazioni che cadono al di sotto del limite di sensibilità del kit utilizzato. Di conseguenza, , , molti laboratori si trovano a dover affrontare la decisione critica di interrompere le analisi rinunciando alla possibilità di ottenere un profilo genetico seppur parziale, oppure tentare l’amplificazione dell’estratto con la consapevolezza dei rischi interpretativi che ne conseguono.
Nel presente lavoro vengono illustrati i risultati della quantificazione mediante qPCR eseguita in numerose campionature da reperti di interesse forense, sottoposte ad estrazione del DNA mediante resina magnetica. Successivamente alla fase quantificativa, gli estratti di DNA venivano sottoposti ad amplificazione e tipizzazione degli STRs mediante kit di ultima generazione, includendo campioni risultati negativi alla quantificazione, al fine di verificare se vi sussista correlazione tra la quantità di DNA rilevata mediante qPCR e la possibilità di ottenere un profilo genetico utile a fini identificativ
TNF TRIGGERS TNFR1 REDISTRIBUTION FROM CAVEOLAE IN AN ENDOTHELIAL CELL LINE
No full textCaveolae, which are invaginations of plasma membrane enriched in cholesterol and glycosphingolipids and coated by the scaffolding proteins caveolin-1 and 2, function to juxtapose signaling receptors of various types so as to permit receptor cross talk. We are interested in whether caveolae influence TNF signaling in human endothelial cells (ECs). Human umbilical vein ECs display abundant caveolae in situ, although these organelles are rapidly lost in culture. We have found that the endothelial cell line EAhy.926, produced by fusing human umbilical vein ECs with the permanent human cell line A549 (human lung carcinoma), retains an extensive caveolar network in vitro. By confocal and by immunoelectron microscopy, TNF receptor I (TNFR1/CD120a), the principal signaling receptor for pro-inflammatory responses, colocalizes with caveolin-1 in the region of the plasmalemma. TNFR1 also co-fractionates with caveolin-1 in a sucrose density gradient isolation of caveolae and caveolin-1 co-immunoprecipitates with TNFR1 in detergent lysates of EAhy.926 cell line. Addition of TNF to EAhy.926 cells induces translocation of TNFR1 from the caveolar fraction and dissociation from caveolin-1 within five minutes. TNF treatment also causes TNFR1 to colocalize with endosomal and lysosomal markers by 30–60 minutes. These studies suggest that TNF initiates the rapid translocation of TNFR1 from caveolae followed by a slower process of internalization
Espressione di Flip nel testicolo di topo e suo ruolo nel controllo dell’apoptosi
No full textABSTRAC
Role of neural cancer stem cells in angiogenesis
No full textGrowing evidence indicates the existence of small population of cells endowed with distinctive self-renewal capacity, tumorigenesis and resistance to conventional treatments, defined as cancer stem cells (CSCs) or tumor initiating cells. In addition, it is widely appreciated that the growth of new blood vessels and lymphatic vasculature, which occurs during angiogenesis and limphoangiogenesis, plays a key role in the process of the tumor growth. To this regards, an increasing number of studies showed that the employment of angiogenesis inhibitors might have significant therapeutic advantages. Fashinatingly, recent evidence demonstrated that CSCs play a role in angiogenesis, in particular in glioma, which, to date, represents a highly letal tumor tough to treat. We demonstrated that CSCs isoleted from both tumor (GCSCs) and peritumoral tissue (PCSCs) express a number of angiogenesis-related molecules, such as VEGF, HIF1alpha and HIF2alpha. In addition, VEGFR1 expression was found significantly reduced in PCSCs vs GCSCs whereas VGFR2 appeard to be largely heterogeneous in both stem cell types. With the aim to investigate the aptitude of CSCs derived neurospheres to regulate the angiogenesis process we performed in vitro migration analysis by means of boiden chamber assay. The results of this experiments indicate that ECs migration was stimulated in the presence of PCSCs but remained almost unaffected when endothelial cells where co-coltured with GCSCs. In conclusion, our data suggest that GCSCs and PCSCs contribute differently to tumor angiogenesis by activating distinct molecular mechanisms. PCSCs might therefore a key role in the recruiment as well as activation of ECs in peritumoral tissue
Nutritional strategies to counteract the loss of muscle mass and function characteristic of senescent muscle.
No full textDuring aging, multifactorial events such as activation of inflammatory pathways and mitochondrial dysfunction lead to the onset of sarcopenia, which is characterized by a gradual loss of muscle protein component. It is well known that changes in the quantity and the quality of dietary proteins, as well as the intake of specific amino acids or antioxidants supplementation, counteract some physiopathological processes related to the progression of the loss of muscle mass and may have beneficial effects in improving the anabolic response of muscle in the elderly. The aim of this research is to delay and hopefully prevent, in a mouse experimental model, the loss of muscle mass and functional capacity of aged muscle by dietary supplementation of micronutrients intake. To this purpose we evaluated whether a protein diet rich in arginine and/or taurine, already known to down-regulate the release of inflammatory cytokines in dystrophic muscles (1, 2), modulates the activation of catabolic processes leading to loss of muscle mass characteristic of aged muscle. To this purpose, adult mice were subjected to intraperitoneal injections of taurine, arginine or both, all days for 2 months. The tibialis anterior muscles (TA) were then damaged by cardiotoxin injection. Our results demonstrate that injured TA muscles of mice which received both aminoacids show enhanced regeneration response as demonstrated by the presence of central nucleated fibers, less amount of inflammatory cells and fibrosis, if compared to the control. Moreover the high expression of the inflammation marker, NF-kB, in injured muscle of control mice strongly decreases in taurine + arginine injected mice. These results suggest a role of taurine and arginine in the down-regulation of inflammation and the enhancement of regeneration in skeletal muscle
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