Cell signaling promoting protein carbonylation does not cause sulfhydryl oxidation: implications to the mechanism of redox signaling

Reactive oxygen species (ROS) have been recognized as second messengers, however, targeting mechanisms for ROS in cell signaling have not been defined. While ROS oxidizing protein cysteine thiols has been the most popular proposed mechanism, our laboratory proposed that ligand/receptor-mediated cell signaling involves protein carbonylation. Peroxiredoxin-6 (Prx6) is one protein that is carbonylated at 10 min after the platelet-derived growth factor (PDGF) stimulation of human pulmonary artery smooth muscle cells. In the present study, the SulfoBiotics Protein Redox State Monitoring Kit Plus (Dojindo Molecular Technologies) was used to test if cysteine residues of Prx6 are oxidized in response to the PDGF stimulation. Human Prx6 has a molecular weight of 25 kDa and contains two cysteine residues. The Dojindo system adds the 15 kDa Protein-SHifter if these cysteine residues are reduced in the cells. Results showed that, in untreated cells, the Prx6 molecule predominantly exhibited the 55 kDa band, indicating that both cysteine residues are reduced in the cells. Treatment of cells with 1 mM H 2O 2 caused the disappearance of the 55 kDa band and the appearance of a 40 kDa band, suggesting that the high concentration of H 2O 2 oxidized one of the two cysteine residues in the Prx6 molecule. By contrast, PDGF stimulation had no effects on the thiol status of the Prx6 molecule. We concluded that protein carbonylation is a more sensitive target of ROS during ligand/receptor-mediated cell signaling than sulfhydryl oxidation

Poly(L-glutamic acid)-co-poly(ethylene glycol) block copolymers for protein conjugation

Poly(L-glutamic acid)-co-poly(ethylene glycol) block copolymers (PLE-PEG) are here investigated as polymers for conjugation to therapeutic proteins such as granulocyte colony stimulating factor (G-CSF) and human growth hormone (hGH). PLE-PEG block copolymers are able to stabilize and protect proteins from degradation and to prolong their residence time in the blood stream, features that are made possible thanks to PEG's intrinsic properties and the simultaneous presence of the biodegradable anionic PLE moiety. When PLE-PEG copolymers are selectively tethered to the N-terminus of G-CSF and hGH, they yield homogeneous monoconjugates that preserve the protein's secondary structure. During the current study the pharmacokinetics of PLE10-PEG20k-G-CSF and PLE20-PEG20k-G-CSF derivatives and their ability to induce granulopoiesis were, respectively, assessed in Sprague-Dawley rats and in C57BL6 mice. Our results show that the bioavailability and bioactivity of the derivatives are comparable to or better than those of PEG20k-Nter-G-CSF (commercially known as Pegfilgrastim). The therapeutic effects of PLE10-PEG20k-hGH and PLE20-PEG20k-hGH derivatives tested in hypophysectomized rats demonstrate that the presence of a negatively charged PLE block enhances the biological properties of the conjugates additionally with respect to PEG20k-Nter-hGH

Properties of star-forming galaxies in a cluster and its surrounding structure at z=1.46

We conduct a narrow-band imaging survey of [OII] emitters over a 32'x23' area in and around the XMMXCS J2215.9-1738 cluster at z=1.46 with Subaru/Suprime-Cam, and select 380 [OII] emitting galaxies down to 1.4E-17 erg/s/cm2. Among them, 16 [OII] emitters in the cluster central region are confirmed by NIR spectroscopy with Subaru/MOIRCS. We find that [OII] emitters are distributed along filamentary large-scale structures around the cluster. The z'-K vs K colour-magnitude diagram shows that a significantly higher fraction of [OII] emitters is seen on the red sequence in the cluster core than in other environments we define in this paper. It is likely that these red galaxies are nearly passively evolving galaxies which host [OII] emitting AGNs, rather than dust-reddened star-forming galaxies. We argue therefore that AGN feedback may be one of the critical processes to quench star formation in massive galaxies in high density regions. We also find that the cluster has experienced high star formation activities at rates comparable to that in the field at z=1.46. In addition, a mass-metallicity relation exists in the cluster at z=1.46, which is similar to that of star-forming galaxies in the field at z~2. These results all suggest that at z~1.5 star formation activity in the cluster core becomes as high as those in low density environments and there is apparently not yet a strong environmental dependence, except for the red emitters.Comment: 19 pages, 17 figures, 4 tables, accepted for publication in MNRA

Pattern of p53 protein expression is predictive for survival in chemoradiotherapy-naive esophageal adenocarcinoma

Introduction: TP53 mutations are considered to be the driving factor in the initiation of esophageal adenocarcinoma (EAC). However, the impact of this gene and its encoded protein as a prognostic marker has not been definitely established yet. Methods: In total, 204 chemoradiotherapy (CRT)-naive patients with EAC were included for p53 protein expression evaluation by immunohistochemistry (IHC) on the resection specimens, categorized as overexpression, heterogeneous or loss of expression, and correlated with disease free survival (DFS) and overall survival (OS) using multivariable Cox regression analysis. In a subset representing all three IHC subgroups mutatio

β-delayed γ-proton decay in 56Zn: analysis of the charged-particle spectrum

A study of the beta decay of the proton-rich T-z = 2 nucleus Zn-56 has been reported in a recent publication. A rare and exotic decay mode, beta-delayed gamma-proton decay, has been observed there for the first time in the fp shell. Here, we expand on some of the details of the data analysis, focussing on the charged particle spectrum

Phase transitions of the mixed spin-1/2 and spin-S Ising model on a three-dimensional decorated lattice with a layered structure

Phase transitions of the mixed spin-1/2 and spin-S (S >= 1/2) Ising model on a three-dimensional (3D) decorated lattice with a layered magnetic structure are investigated within the framework of a precise mapping relationship to the simple spin-1/2 Ising model on the tetragonal lattice. This mapping correspondence yields for the layered Ising model of mixed spins plausible results either by adopting the conjectured solution for the spin-1/2 Ising model on the orthorhombic lattice [Z.-D. Zhang, Philos. Mag. 87 (2007) 5309-5419] or by performing extensive Monte Carlo simulations for the corresponding spin-1/2 Ising model on the tetragonal lattice. It is shown that the critical behaviour markedly depends on a relative strength of axial zero-field splitting parameter, inter- and intra-layer interactions. The striking spontaneous order captured to the 'quasi-1D' spin system is found in a restricted region of interaction parameters, where the zero-field splitting parameter forces all integer-valued decorating spins towards their 'non-magnetic' spin state.Comment: 18 pages, 5 figures, Monte Carlo simulation data has been added to this revised versio

The Effect of Prolonged Physical Activity Performed during Extreme Caloric Deprivation on Cardiac Function

Background: Endurance exercise may induce transient cardiac dysfunction. Data regarding the effect of caloric restriction on cardiac function is limited. We studied the effect of physical activity performed during extreme caloric deprivation on cardiac function. Methods: Thirty-nine healthy male soldiers (mean age 2060.3 years) were studied during a field training exercise lasted 85– 103 hours, with negligible food intake and unlimited water supply. Anthropometric measurements, echocardiographic examinations and blood and urine tests were performed before and after the training exercise. Results: Baseline VO2 max was 5965.5 ml/kg/min. Participants ’ mean weight reduction was 5.760.9 kg. There was an increase in plasma urea (11.662.6 to 15.863.8 mmol/L, p,0.001) and urine osmolarity (6926212 to 10946140 mmol/kg, p,0.001) and a decrease in sodium levels (140.561.0 to 136.662.1 mmol/L, p,0.001) at the end of the study. Significant alterations in diastolic parameters included a decrease in mitral E wave (93.6 to 83.5 cm/s; p = 0.003), without change in E/A and E/E9 ratios, and an increase in iso-volumic relaxation time (73.9 to 82.9 ms, p = 0.006). There was no change in left or right ventricular systolic function, or pulmonary arterial pressure. Brain natriuretic peptide (BNP) levels were significantly reduced post-training (median 9 to 0 pg/ml, p,0.001). There was no elevation in Troponin T or CRP levels. On multivariate analysis, BNP reduction correlated with sodium levels and weight reduction (R = 0.8, p,0.001)

IL-6 signaling by STAT3 participates in the change from hyperplasia to neoplasia in NRP-152 and NRP-154 rat prostatic epithelial cells

BACKGROUND: STAT3 phosphorylation is associated with the neoplastic state in many types of cancer, including prostate cancer. We investigated the role of IL-6 signaling and phosphorylation of STAT3 in 2 rat prostatic epithelial lines. NRP-152 and NRP-154 cells were derived from the same rat prostate, yet the NRP-152 cells are not tumorigenic while the NRP-154 cells are tumorigenic. These lines are believed to represent 2 of the stages in the development of prostate cancer, hyperplasia and neoplasia. Differences in signaling pathways should play a role in the 2 phenotypes, hyperplastic and neoplastic. METHODS: We looked at the phosphorylation state of STAT3 by intracellular flow cytometry, using phospho-specific antibodies to STAT3. We used the same method to examine IL-6 production by the cell lines. We also measured apoptosis by binding of fluorescent annexin V to the cells. RESULTS: Although both cells lines made IL-6 constitutively, phosphorylated-STAT3 was present in untreated NRP-154 cells, but not in NRP-152 cells. Treatment with dexamethasone inhibited the IL-6 production of NRP-152 cells, but enhanced that of NRP-154 cells. Treatment with the JAK2 inhibitor AG490 induced apoptosis in NRP-152, but not NRP-154 cells. CONCLUSIONS: We conclude from these experiments that STAT3 activity plays a role in the phenotype of NRP-154 cell, but not NRP-152 cells. The significance of alternative IL-6 signaling pathways in the different phenotypes of the 2 cell lines is discussed

Dominance of Objects over Context in a Mediotemporal Lobe Model of Schizophrenia

Background: A large body of evidence suggests impaired context processing in schizophrenia. Here we propose that this impairment arises from defective integration of mediotemporal ‘what ’ and ‘where ’ routes, carrying object and spatial information to the hippocampus. Methodology and Findings: We have previously shown, in a mediotemporal lobe (MTL) model, that the abnormal connectivity between MTL regions observed in schizophrenia can explain the episodic memory deficits associated with the disorder. Here we show that the same neuropathology leads to several context processing deficits observed in patients with schizophrenia: 1) failure to choose subordinate stimuli over dominant ones when the former fit the context, 2) decreased contextual constraints in memory retrieval, as reflected in increased false alarm rates and 3) impaired retrieval of contextual information in source monitoring. Model analyses show that these deficits occur because the ‘schizophrenic MTL ’ forms fragmented episodic representations, in which objects are overrepresented at the expense of spatial contextual information. Conclusions and Significance: These findings highlight the importance of MTL neuropathology in schizophrenia, demonstrating that it may underlie a broad spectrum of deficits, including context processing and memory impairments. It is argued that these processing deficits may contribute to central schizophrenia symptoms such as contextuall