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91.
Fincato P Moschou PN Ahou A Angelini R Roubelakis-Angelakis KA Federico R Tavladoraki P 《Amino acids》2012,42(2-3):831-841
Polyamine oxidases (PAOs) are FAD-dependent enzymes involved in polyamine catabolism. In Arabidopsis thaliana, five PAOs (AtPAO1-5) are present with cytosolic or peroxisomal localization. Here, we present a detailed study of the expression pattern of AtPAO1, AtPAO2, AtPAO3 and AtPAO5 during seedling and flower growth and development through analysis of promoter activity in AtPAO::β-glucuronidase (GUS) transgenic Arabidopsis plants. The results reveal distinct expression patterns for each studied member of the AtPAO gene family. AtPAO1 is mostly expressed in the transition region between the meristematic and the elongation zone of roots and anther tapetum, AtPAO2 in the quiescent center, columella initials and pollen, AtPAO3 in columella, guard cells and pollen, and AtPAO5 in the vascular system of roots and hypocotyls. Furthermore, treatment with the plant hormone abscisic acid induced expression of AtPAO1 in root tip and AtPAO2 in guard cells. These data suggest distinct physiological role(s) for each member of the AtPAO gene family. 相似文献
92.
Tight regulation of cell cycle is of critical importance for eukaryotic biology and is achieved through a combined action of a large number of highly specialized proteins. Separases are evolutionarily conserved caspase-like proteases playing a crucial role in cell cycle regulation, as they execute sister chromatid separation at metaphase to anaphase transition. In contrast to extensively studied yeast and metazoan separases, very little is known about the role of separases in plant biology. Here we describe the molecular mechanisms of separase-mediated chromatid segregation in yeast and metazoan models, discuss new emerging but less-understood functions of separases and highlight major gaps in our knowledge about plant separases. 相似文献
93.
Hair follicle harbors a rich stem cell pool with mesenchymal lineage differentiation potential. Although previous studies with rodent cells demonstrated that hair follicle sheath and papilla cells possess multi-lineage differentiation potential, human hair follicle derived mesenchymal stem cells (hHF-MSCs) have not been characterized in detail in terms of their multipotency. In addition, it is not clear whether these cells are true stem cells that can differentiate along multiple lineages or whether they represent a collection of progenitor cells with restricted differentiation potential. Here we report that hHF-MSCs are highly proliferative cells that can be maintained in culture for ~ 45 population doublings before they start to show signs of cellular senescence. Under appropriate culture conditions, hHF-MSCs differentiated along the myogenic, osteogenic, adipogenic and chondrogenic lineages, as demonstrated by kinetic gene expression profiling and functional assays. Interestingly, the differentiation potential decreased with time in culture in a lineage-specific manner. Specifically, myogenesis and chondrogenesis showed a moderate decrease over time; osteogenesis was maximum at intermediate passages and adipogenesis was highly sensitive to long-term culture and was diminished at late passages. Finally, hHF-MSCs were clonally multipotent as the majority of hHF-MSCs clones (73%) demonstrated bi- or tri-lineage differentiation potential. These results suggest that hHF-MSCs may present as an alternative source of easily accessible, autologous stem cells for tissue engineering and regenerative medicine. 相似文献
94.
M Papamichail M Digalakis P Panagiotis O Paisios S Loti T Sergentanis 《BMC research notes》2012,5(1):463
ABSTRACT: BACKGROUND: Interposition of a reversed jejunal loop in short bowel sydrome has previously been investigated in human along with animal models and seemed able to facilitate intestinal adaptation. However, it is unclear if growth hormone and insulin, well known for their implication in short bowel pathophysiology, intervene on this effect. FINDINGS: Porcine models were randomly allocated to two cohorts: (1) short bowel (SB) group (n = 8) and (2) short bowel reverse jejunal segment (SB-RS) group (n = 8). Amongst other parameters serum growth hormone and insulin were measured at baseline, as well as on postoperative day 30 and 60. CONCLUSION: Both endogenous hormones failed to demonstrate significant difference in respect to potential direct effect to mechanisms of enhanced intestinal adaptation in reversed group. 相似文献
95.
Patrikidou A Vlachostergios PJ Voutsadakis IA Hatzidaki E Valeri RM Destouni C Apostolou E Papandreou CN 《Cancer cell international》2012,12(1):31-14
Background
Upregulation of nuclear factor kappa B (NF??B) activity and neuroendocrine differentiation are two mechanisms known to be involved in prostate cancer (PC) progression to castration resistance. We have observed that major components of these pathways, including NF??B, proteasome, neutral endopeptidase (NEP) and endothelin 1 (ET-1), exhibit an inverse and mirror image pattern in androgen-dependent (AD) and -independent (AI) states in vitro.Methods
We have now investigated for evidence of a direct mechanistic connection between these pathways with the use of immunocytochemistry (ICC), western blot analysis, electrophoretic mobility shift assay (EMSA) and proteasome activity assessment.Results
Neuropeptide (NP) stimulation induced nuclear translocation of NF??B in a dose-dependent manner in AI cells, also evident as reduced total inhibitor ??B (I??B) levels and increased DNA binding in EMSA. These effects were preceded by increased 20?S proteasome activity at lower doses and at earlier times and were at least partially reversed under conditions of NP deprivation induced by specific NP receptor inhibitors, as well as NF??B, I??B kinase (IKK) and proteasome inhibitors. AD cells showed no appreciable nuclear translocation upon NP stimulation, with less intense DNA binding signal on EMSA.Conclusions
Our results support evidence for a direct mechanistic connection between the NPs and NF??B/proteasome signaling pathways, with a distinct NP-induced profile in the more aggressive AI cancer state. 相似文献96.
Zoidakis J Makridakis M Zerefos PG Bitsika V Esteban S Frantzi M Stravodimos K Anagnou NP Roubelakis MG Sanchez-Carbayo M Vlahou A 《Molecular & cellular proteomics : MCP》2012,11(4):M111.009449
Of the most important clinical needs for bladder cancer (BC) management is the identification of biomarkers for disease aggressiveness. Urine is a "gold mine" for biomarker discovery, nevertheless, with multiple proteins being in low amounts, urine proteomics becomes challenging. In the present study we applied a fractionation strategy of urinary proteins based on the use of immobilized metal affinity chromatography for the discovery of biomarkers for aggressive BC. Urine samples from patients with non invasive (two pools) and invasive (two pools) BC were subjected to immobilized metal affinity chromatography fractionation and eluted proteins analyzed by 1D-SDS-PAGE, band excision and liquid chromatography tandem MS. Among the identified proteins, multiple corresponded to proteins with affinity for metals and/or reported to be phosphorylated and included proteins with demonstrated association with BC such as MMP9, fibrinogen forms, and clusterin. In agreement to the immobilized metal affinity chromatography results, aminopeptidase N, profilin 1, and myeloblastin were further found to be differentially expressed in urine from patients with invasive compared with non invasive BC and benign controls, by Western blot or Elisa analysis, nevertheless exhibiting high interindividual variability. By tissue microarray analysis, profilin 1 was found to have a marked decrease of expression in the epithelial cells of the invasive (T2+) versus high risk non invasive (T1G3) tumors with occasional expression in stroma; importantly, this pattern strongly correlated with poor prognosis and increased mortality. The functional relevance of profilin 1 was investigated in the T24 BC cells where blockage of the protein by the use of antibodies resulted in decreased cell motility with concomitant decrease in actin polymerization. Collectively, our study involves the application of a fractionation method of urinary proteins and as one main result of this analysis reveals the association of profilin 1 with BC paving the way for its further investigation in BC stratification. 相似文献
97.
Panagiotis Bargiotas Antje Krenz Hannah Monyer Markus Schwaninger 《Channels (Austin, Tex.)》2012,6(6):453-456
Pannexin (Px, Panx) channels have been implicated in several physiological and pathological processes. We recently studied the potential contribution of pannexins in ischemic brain damage using Px1-/- Px2-/- mice and provided evidence that (1) the release of IL-1β and hemichannel function in astrocytes are, in contrast to published data, not affected by the absence of Px1 and Px2, (2) channel function in neurons lacking Px1 and Px2 is impaired and (3) Px1-/- Px2-/- mice had a better functional outcome and smaller infarcts than wild-type mice when subjected to ischemic stroke. Here, we further investigate the neurological outcome of wild-type and pannexin double-knockout mice 48 h after permanent occlusion of the distal middle cerebral artery (MCAO). Pannexin double-knockout mice (Px1-/- Px2-/-) were less impaired in parameters such as exploration, anxiety, sensorimotor function and behavioral symmetry. 相似文献
98.
Chrysa Lithari Manousos A. Klados Costas Pappas Maria Albani Dorothea Kapoukranidou Leda Kovatsi Panagiotis D. Bamidis Christos L. Papadelis 《PloS one》2012,7(10)
Acute alcohol intake is known to enhance inhibition through facilitation of GABAA receptors, which are present in 40% of the synapses all over the brain. Evidence suggests that enhanced GABAergic transmission leads to increased large-scale brain connectivity. Our hypothesis is that acute alcohol intake would increase the functional connectivity of the human brain resting-state network (RSN). To test our hypothesis, electroencephalographic (EEG) measurements were recorded from healthy social drinkers at rest, during eyes-open and eyes-closed sessions, after administering to them an alcoholic beverage or placebo respectively. Salivary alcohol and cortisol served to measure the inebriation and stress levels. By calculating Magnitude Square Coherence (MSC) on standardized Low Resolution Electromagnetic Tomography (sLORETA) solutions, we formed cortical networks over several frequency bands, which were then analyzed in the context of functional connectivity and graph theory. MSC was increased (p<0.05, corrected with False Discovery Rate, FDR corrected) in alpha, beta (eyes-open) and theta bands (eyes-closed) following acute alcohol intake. Graph parameters were accordingly altered in these bands quantifying the effect of alcohol on the structure of brain networks; global efficiency and density were higher and path length was lower during alcohol (vs. placebo, p<0.05). Salivary alcohol concentration was positively correlated with the density of the network in beta band. The degree of specific nodes was elevated following alcohol (vs. placebo). Our findings support the hypothesis that short-term inebriation considerably increases large-scale connectivity in the RSN. The increased baseline functional connectivity can -at least partially- be attributed to the alcohol-induced disruption of the delicate balance between inhibitory and excitatory neurotransmission in favor of inhibitory influences. Thus, it is suggested that short-term inebriation is associated, as expected, to increased GABA transmission and functional connectivity, while long-term alcohol consumption may be linked to exactly the opposite effect. 相似文献
99.
Mariarosaria Bucci Andreas Papapetropoulos Valentina Vellecco Zongmin Zhou Altaany Zaid Panagiotis Giannogonas Anna Cantalupo Sandeep Dhayade Katia P. Karalis Rui Wang Robert Feil Giuseppe Cirino 《PloS one》2012,7(12)
A growing body of evidence suggests that hydrogen sulfide (H2S) is a signaling molecule in mammalian cells. In the cardiovascular system, H2S enhances vasodilation and angiogenesis. H2S-induced vasodilation is hypothesized to occur through ATP-sensitive potassium channels (KATP); however, we recently demonstrated that it also increases cGMP levels in tissues. Herein, we studied the involvement of cGMP-dependent protein kinase-I in H2S-induced vasorelaxation. The effect of H2S on vessel tone was studied in phenylephrine-contracted aortic rings with or without endothelium. cGMP levels were determined in cultured cells or isolated vessel by enzyme immunoassay. Pretreatment of aortic rings with sildenafil attenuated NaHS-induced relaxation, confirming previous findings that H2S is a phosphodiesterase inhibitor. In addition, vascular tissue levels of cGMP in cystathionine gamma lyase knockouts were lower than those in wild-type control mice. Treatment of aortic rings with NaHS, a fast releasing H2S donor, enhanced phosphorylation of vasodilator-stimulated phosphoprotein in a time-dependent manner, suggesting that cGMP-dependent protein kinase (PKG) is activated after exposure to H2S. Incubation of aortic rings with a PKG-I inhibitor (DT-2) attenuated NaHS-stimulated relaxation. Interestingly, vasodilatory responses to a slowly releasing H2S donor (GYY 4137) were unaffected by DT-2, suggesting that this donor dilates mouse aorta through PKG-independent pathways. Dilatory responses to NaHS and L-cysteine (a substrate for H2S production) were reduced in vessels of PKG-I knockout mice (PKG-I−/−). Moreover, glibenclamide inhibited NaHS-induced vasorelaxation in vessels from wild-type animals, but not PKG-I−/−, suggesting that there is a cross-talk between KATP and PKG. Our results confirm the role of cGMP in the vascular responses to NaHS and demonstrate that genetic deletion of PKG-I attenuates NaHS and L-cysteine-stimulated vasodilation. 相似文献
100.
SC Joachim OW Gramlich P Laspas H Schmid S Beck HD von Pein HB Dick N Pfeiffer FH Grus 《PloS one》2012,7(7):e40616