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排序方式: 共有598条查询结果,搜索用时 15 毫秒
91.
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93.
The role of extrahepatic retinol binding protein in the mobilization of retinoid stores 总被引:4,自引:0,他引:4
Quadro L Blaner WS Hamberger L Novikoff PM Vogel S Piantedosi R Gottesman ME Colantuoni V 《Journal of lipid research》2004,45(11):1975-1982
Although the major tissue site of retinol binding protein (RBP) synthesis in the body is the liver, other sites of synthesis have been reported. The physiological role(s) of circulating RBP that is produced and secreted extrahepatically has not been systematically investigated. To address this question, we used as a model a mouse strain (hRBP(-/-)) that expresses human RBP (hRBP) cDNA under the control of the mouse muscle creatine kinase promoter in an rbp-null background (RBP(-/-)). By comparing hRBP(-/-), RBP(-/-), and wild-type mice, we asked whether extrahepatic RBP can perform all of the physiological functions of RBP synthesized in the liver. We demonstrate that extrahepatically synthesized hRBP, unlike RBP expressed in liver, cannot mobilize liver retinoid stores. Consistent with this conclusion, we find that circulating hRBP is not taken up by hepatocytes. RBP has been proposed to play an essential role in distributing hepatic retinoids between hepatocytes and hepatic stellate cells. We find, however, that the distribution of retinoid in the livers of the three mouse strains described above is identical. Thus, RBP is not required for intrahepatic transport and storage of retinoid. These and other observations are discussed. 相似文献
94.
Anna Di Vito Maria Mele Antonella Piscioneri Sabrina Morelli Loredana De Bartolo Tullio Barni Rosa Maria Facciolo Marcello Canonaco 《Cellular and molecular neurobiology》2014,34(4):501-509
It’s known that neurons in mammalian hibernators are more tolerant to hypoxia than those in non-hibernating species and as a consequence animals are capable of awakening from the arousal state without exhibiting cerebral damages. In addition, evidences have suggested that euthermic hamster neurons display protective adaptations against hypoxia, while those of rats are not capable, even though molecular mechanisms involved in similar neuroprotective strategies have not been yet fully studied. In the present work, overstimulation of glutamatergic receptors NMDA recognized as one of the major death-promoting element in hypoxia, accounted for altered network complexity consistent with a moderate reduction of hippocampal neuronal survival (p < 0.05) in hamsters. These alterations appeared to be featured concomitantly with altered glutamatergic signaling as indicated by significant down-regulation (p < 0.01) of NMDAergic (NR2A) and AMPAergic (GluR1, R2) receptor subtypes together with the metabotropic mGluR5 subtype. Diminished mRNA levels were also reported for NMDA receptor binding factors and namely PSD95 plus DREAM, which exert positive and negative regulatory properties, respectively, on receptor trafficking events. Conversely, involvement of glutamatergic signaling systems on neuronal excitotoxicity was strengthened by the co-activation of GABAAR-mediated effects as indicated by toxic morphological effects being notably reduced along with up-regulated GluR1, GluR2, mGluR5, DREAM, and Homer1c scaffold proteins when muscimol was added. Overall, these results point to a neuroprotective role of the GABAergic system against excitotoxicity episodes via DREAM-dependent inhibition of NMDA receptor and activation of AMPA receptor plus mGluR5, respectively, thus proposing them as novel therapeutic targets against cerebral ischemic damages in humans. 相似文献
95.
Spinello Antinori Laurenzia Ferraris Giovanna Orlando Loredana Tocalli Davide Ricaboni Mario Corbellino Salvatore Sollima Massimo Galli Laura Milazzo 《Mycopathologia》2014,178(1-2):37-51
Background
Fungal endocarditis (FE) is a “modern” disease that is considered an emerging cause of infective endocarditis (IE). The most frequently identified fungal pathogens are Candida spp., which are responsible for up to two-thirds of all cases; the remaining cases are due to Aspergillus spp., Histoplasma capsulatum or, more rarely, other yeasts and moulds.Objectives
To describe the prevalence, clinical characteristics and outcome of FE diagnosed in a single tertiary centre and review the literature concerning FE.Design and setting
An 8-year retrospective review of the case records of patients attending a single Italian University Centre and diagnosed as having definite or probable IE as defined by the modified Duke criteria.Results
Six patients were identified from 229 episodes of IE: five cases involved a prosthetic valve, and one a native valve of an intravenous drug user. Five cases were caused by Candida spp. (two by C. albicans, one each by C. lusitaniae, C. dubliniensis and C. glabrata) and one by Aspergillus flavus. Three patients were treated by means of surgery plus antifungal therapy; two received antifungal therapy alone. Three patients survived, but only the patient with Aspergillus endocarditis was followed up for a long time.Conclusions
FE is difficult to diagnose but generally associated with healthcare infections. The optimal treatment is poorly characterised, and international collaborative studies are urgently needed to evaluate newer antifungal agents. 相似文献96.
Loredana Mauro Michele Pellegrino Francesca De Amicis Emilia Ricchio Francesca Giordano Pietro Rizza 《Cell cycle (Georgetown, Tex.)》2014,13(4):553-564
Adiponectin, the most abundant protein secreted by adipose tissue, exhibits insulin-sensitizing, anti-inflammatory, antiatherogenic, and antiproliferative properties. In addition, it appears to play an important role also in the development and progression of several obesity-related malignancies, including breast cancer. Here, we demonstrated that adiponectin induces a dichotomic effect on breast cancer growth. Indeed, it stimulates growth in ERα+ MCF-7 cells while inhibiting proliferation of ERα? MDA-MB-231 cells. Notably, only in MCF-7 cells adiponectin exposure exerts a rapid activation of MAPK phosphorylation, which is markedly reduced when knockdown of the ERα gene occurred. In addition, adiponectin induces rapid IGF-IR phosphorylation in MCF-7 cells, and the use of ERα siRNA prevents this effect. Moreover, MAPK activation induced by adiponectin was reversed by IGF-IR siRNA. Coimmunoprecipitation studies show the existence of a multiprotein complex involving AdipoR1, APPL1, ERα, IGF-IR, and c-Src that is responsible for MAPK signaling activation in ERα+ positive breast cancer cells. It is well known that in addition to the rapid effects through non-genomic mechanisms, ERα also mediates nuclear genomic actions. In this concern, we demonstrated that adiponectin is able to transactivate ERα in MCF-7 cells. We showed the classical features of ERα transactivation: nuclear localization, downregulation of mRNA and protein levels, and upregulation of estrogen-dependent genes. Thus, our study clarifies the molecular mechanism through which adiponectin modulates breast cancer cell growth, providing evidences on the cell-type dependency of adiponectin action in relationship to ERα status. 相似文献
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98.
Kelly Brooks Max Ranall Loredana Spoerri Alex Stevenson Gency Gunasingh Sandra Pavey Fred Meunier Thomas J. Gonda Brian Gabrielli 《Pigment cell & melanoma research》2014,27(5):813-821
Melanoma cell lines are commonly defective for the G2‐phase cell cycle checkpoint that responds to incomplete catenation of the replicated chromosomes. Here, we demonstrate that melanomas defective for this checkpoint response are less sensitive to genotoxic stress, suggesting that the defective cell lines compensated for the checkpoint loss by increasing their ability to cope with DNA damage. We performed an siRNA kinome screen to identify kinases responsible and identified PI3K pathway components. Checkpoint‐defective cell lines were three‐fold more sensitive to small molecule inhibitors of PI3K. The PI3K inhibitor PF‐05212384 promoted apoptosis in the checkpoint‐defective lines, and the increased sensitivity to PI3K inhibition correlated with increased levels of activated Akt. This work demonstrates that increased PI3K pathway activation is a necessary adaption for the continued viability of melanomas with a defective decatenation checkpoint. 相似文献
99.
Veronica Dimuccio Andrea Ranghino Loredana Praticò Barbato Fabrizio Fop Luigi Biancone Giovanni Camussi Benedetta Bussolati 《PloS one》2014,9(8)
Extracellular vesicles (EVs) present in the urine are mainly released from cells of the nephron and can therefore provide information on kidney function. We here evaluated the presence of vesicles expressing the progenitor marker CD133 in the urine of normal subjects and of patients undergoing renal transplant. We found that EV expressing CD133 were present in the urine of normal subjects, but not of patients with end stage renal disease. The first day after transplant, urinary CD133+ EVs were present at low levels, to increase thereafter (at day 7). Urinary CD133+ EVs significantly increased in patients with slow graft function in respect to those with early graft function. In patients with a severe pre-transplant vascular damage of the graft, CD133+ EVs did not increase at day 7. At variance, the levels of EVs expressing the renal exosomal marker CD24 did not vary in the urine of patients with end stage renal disease or in transplanted patients in respect to controls. Sorted CD133+ EVs were found to express glomerular and proximal tubular markers. These data indicate that urinary CD133+ EVs are continuously released during the homeostatic turnover of the nephron and may provide information on its function or regenerative potential. 相似文献
100.
Enida Gjoni Loredana Brioschi Alessandra Cinque Nicolas Coant M. Nurul Islam Carl K. -Y. Ng Claudia Verderio Christophe Magnan Laura Riboni Paola Viani Hervé Le Stunff Paola Giussani 《PloS one》2014,9(10)
Accumulating evidence suggests that glucolipotoxicity, arising from the combined actions of elevated glucose and free fatty acid levels, acts as a key pathogenic component in type II diabetes, contributing to β-cell dysfunction and death. Endoplasmic reticulum (ER) stress is among the molecular pathways and regulators involved in these negative effects, and ceramide accumulation due to glucolipotoxicity can be associated with the induction of ER stress. Increased levels of ceramide in ER may be due to enhanced ceramide biosynthesis and/or decreased ceramide utilization. Here, we studied the effect of glucolipotoxic conditions on ceramide traffic in INS-1 cells in order to gain insights into the molecular mechanism(s) of glucolipotoxicity. We showed that glucolipotoxicity inhibited ceramide utilization for complex sphingolipid biosynthesis, thereby reducing the flow of ceramide from the ER to Golgi. Glucolipotoxicity impaired both vesicular- and CERT-mediated ceramide transport through (1) the decreasing of phospho-Akt levels which in turn possibly inhibits vesicular traffic, and (2) the reducing of the amount of active CERT mainly due to a lower protein levels and increased protein phosphorylation to prevent its localization to the Golgi. In conclusion, our findings provide evidence that glucolipotoxicity-induced ceramide overload in the ER, arising from a defect in ceramide trafficking may be a mechanism that contributes to dysfunction and/or death of β-cells exposed to glucolipotoxicity. 相似文献