The Effect of Cerium Oxide During Pregnancy on the Development of the Testicular Tissue of Newborn NMRI Mice

Biological Trace Element Research - Cerium(IV) oxide is widely used as a catalyst in all aspects of human life and human beings are exposed to these materials. The purpose of this experimental...     

Evidence for a large conductance voltage gated cationic channel in rough endoplasmic reticulum of rat hepatocytes

In this work, we report the single channel characterization of a voltage gated cationic channel from rough endoplasmic reticulum (RER) membranes of rat hepatocytes incorporated into a planar lipid bilayer. The channel was found to be cation selective with a main conductance of 598+/-20 pS in 200 mM KCl cis/50 mM KCl trans. The channel open probability appeared voltage dependent with a voltage for half activation (V(1/2)) of 38 mV and an effective gating charge z of -6.66. Adding either 4-AP (5 mM) or ATP (2.5 mM) to the side corresponding to the cell internal medium caused a strong inhibition of the channel activity. This channel is likely to be involved in maintaining proper cation homeostasis in the RER of hepatocytes.     

Mechanisms of oncostatin M-induced pulmonary inflammation and fibrosis

Oncostatin M (OSM), an IL-6 family cytokine, has been implicated in a number of biological processes including the induction of inflammation and the modulation of extracellular matrix. In this study, we demonstrate that OSM is up-regulated in the bronchoalveolar lavage fluid of patients with idiopathic pulmonary fibrosis and scleroderma, and investigate the pathological consequences of excess OSM in the lungs. Delivery of OSM to the lungs of mice results in a significant recruitment of inflammatory cells, as well as a dose-dependent increase in collagen deposition in the lungs, with pathological correlates to characteristic human interstitial lung disease. To better understand the relationship between OSM-induced inflammation and OSM-induced fibrosis, we used genetically modified mice and show that the fibrotic response is largely independent of B and T lymphocytes, eosinophils, and mast cells. We further explored the mechanisms of OSM-induced inflammation and fibrosis using both protein and genomic array approaches, generating a "fibrotic footprint" for OSM that shows modulation of various matrix metalloproteinases, extracellular matrix components, and cytokines previously implicated in fibrosis. In particular, although the IL-4/IL-13 and TGF-beta pathways have been shown to be important and intertwined of fibrosis, we show that OSM is capable of inducing lung fibrosis independently of these pathways. The demonstration that OSM is a potent mediator of lung inflammation and extracellular matrix accumulation, combined with the up-regulation observed in patients with pulmonary fibrosis, may provide a rationale for therapeutically targeting OSM in human disease.     

TSG-6 regulates bone remodeling through inhibition of osteoblastogenesis and osteoclast activation

TSG-6 is an inflammation-induced protein that is produced at pathological sites, including arthritic joints. In animal models of arthritis, TSG-6 protects against joint damage; this has been attributed to its inhibitory effects on neutrophil migration and plasmin activity. Here we investigated whether TSG-6 can directly influence bone erosion. Our data reveal that TSG-6 inhibits RANKL-induced osteoclast differentiation/activation from human and murine precursor cells, where elevated dentine erosion by osteoclasts derived from TSG-6(-/-) mice is consistent with the very severe arthritis seen in these animals. However, the long bones from unchallenged TSG-6(-/-) mice were found to have higher trabecular mass than controls, suggesting that in the absence of inflammation TSG-6 has a role in bone homeostasis; we have detected expression of the TSG-6 protein in the bone marrow of unchallenged wild type mice. Furthermore, we have observed that TSG-6 can inhibit bone morphogenetic protein-2 (BMP-2)-mediated osteoblast differentiation. Interaction analysis revealed that TSG-6 binds directly to RANKL and to BMP-2 (as well as other osteogenic BMPs but not BMP-3) via composite surfaces involving its Link and CUB modules. Consistent with this, the full-length protein is required for maximal inhibition of osteoblast differentiation and osteoclast activation, although the isolated Link module retains significant activity in the latter case. We hypothesize that TSG-6 has dual roles in bone remodeling; one protective, where it inhibits RANKL-induced bone erosion in inflammatory diseases such as arthritis, and the other homeostatic, where its interactions with BMP-2 and RANKL help to balance mineralization by osteoblasts and bone resorption by osteoclasts.     

Novel DNA methylation marker discovery by assumption‐free genome‐wide association analysis of cognitive function in twins

Privileged by rapid increase in available epigenomic data, epigenome‐wide association studies (EWAS) are to make a profound contribution to understand the molecular mechanism of DNA methylation in cognitive aging. Current statistical methods used in EWAS are dominated by models based on multiple assumptions, for example, linear relationship between molecular profiles and phenotype, normal distribution for the methylation data and phenotype. In this study, we applied an assumption‐free method, the generalized correlation coefficient (GCC), and compare it to linear models, namely the linear mixed model and kinship model. We use DNA methylation associated with a cognitive score in 400 and 206 twins as discovery and replication samples respectively. DNA methylation associated with cognitive function using GCC, linear mixed model, and kinship model, identified 65 CpGs (p < 1e‐04) from discovery sample displaying both nonlinear and linear correlations. Replication analysis successfully replicated 9 of these top CpGs. When combining results of GCC and linear models to cover diverse patterns of relationships, we identified genes like KLHDC4, PAPSS2, and MRPS18B as well as pathways including focal adhesion, axon guidance, and some neurological signaling. Genomic region‐based analysis found 15 methylated regions harboring 11 genes, with three verified in gene expression analysis, also the 11 genes were related to top functional clusters including neurohypophyseal hormone and maternal aggressive behaviors. The GCC approach detects valuable methylation sites missed by traditional linear models. A combination of methylation markers from GCC and linear models enriched biological pathways sensible in neurological function that could implicate cognitive performance and cognitive aging.     

Simultaneous electrochemical determination of l-cysteine and l-cysteine disulfide at carbon ionic liquid electrode

A linear sweep voltammetric method is used for direct simultaneous determination of l-cysteine and l-cysteine disulfide (cystine) based on carbon ionic liquid electrode. With carbon ionic liquid electrode as a high performance electrode, two oxidation peaks for l-cysteine (0.62 V) and l-cysteine disulfide (1.3 V) were observed with a significant separation of about 680 mV (vs. Ag/AgCl) in phosphate buffer solution (pH 6.0). The linear ranges were obtained as 1.0–450 and 5.0–700 μM and detection limits were estimated to be 0.298 and 4.258 μM for l-cysteine and l-cysteine disulfide, respectively. This composite electrode was applied for simultaneous determination of l-cysteine and l-cysteine disulfide in two real samples, artificial urine and nutrient broth. Satisfactory results were obtained which clearly indicate the applicability of the proposed electrode for simultaneous determination of these compounds in complex matrices.     

The Degree of Resistance of Erythrocyte Membrane Cytoskeletal Proteins to Supra-Physiologic Concentrations of Calcium: An In Vitro Study

Calcium is a key regulator of cell dynamics. Dysregulation of its cytosolic concentration is implicated in the pathophysiology of several diseases. This study aimed to assess the effects of calcium on the network of membrane cytoskeletal proteins. Erythrocyte membranes were obtained from eight healthy donors and incubated with 250 µM and 1.25 mM calcium solutions. Membrane cytoskeletal proteins were quantified using SDS-PAGE at baseline and after 3 and 5 days of incubation. Supra-physiologic concentrations of calcium (1.25 mM) induced a significant proteolysis in membrane cytoskeletal proteins, compared with magnesium (p < 0.001). Actin exhibited the highest sensitivity to calcium-induced proteolysis (6.8 ± 0.3 vs. 5.3 ± 0.6, p < 0.001), while spectrin (39.9 ± 1.0 vs. 40.3 ± 2.0, p = 0.393) and band-6 (6.3 ± 0.3 vs. 6.8 ± 0.8, p = 0.191) were more resistant to proteolysis after incubation with calcium in the range of endoplasmic reticulum concentrations (250 µM). Aggregation of membrane cytoskeletal proteins was determined after centrifugation and was significantly higher after incubation with calcium ions compared with control, EDTA and magnesium solutions (p < 0.001). In a supra-physiologic range of 1.25–10 mM of calcium ions, there was a nearly perfect linear relationship between calcium concentration and aggregation of erythrocyte membrane cytoskeletal proteins (R ² = 0.971, p < 0.001). Our observation suggests a strong interaction between calcium ions and membrane cytoskeletal network. Cumulative effects of disrupted calcium homeostasis on cytoskeletal proteins need to be further investigated at extended periods of time in disease states.