MAPK signaling to the early secretory pathway revealed by kinase/phosphatase functional screening

To what extent the secretory pathway is regulated by cellular signaling is unknown. In this study, we used RNA interference to explore the function of human kinases and phosphatases in controlling the organization of and trafficking within the secretory pathway. We identified 122 kinases/phosphatases that affect endoplasmic reticulum (ER) export, ER exit sites (ERESs), and/or the Golgi apparatus. Numerous kinases/phosphatases regulate the number of ERESs and ER to Golgi protein trafficking. Among the pathways identified, the Raf–MEK (MAPK/ERK [extracellular signal-regulated kinase] kinase)–ERK cascade, including its regulatory proteins CNK1 (connector enhancer of the kinase suppressor of Ras-1) and neurofibromin, controls the number of ERESs via ERK2, which targets Sec16, a key regulator of ERESs and COPII (coat protein II) vesicle biogenesis. Our analysis reveals an unanticipated complexity of kinase/phosphatase-mediated regulation of the secretory pathway, uncovering a link between growth factor signaling and ER export.     

Environment-related variations of the composition of the essential oils of rosemary (Rosmarinus officinalis L.) in the Balkan Penninsula

Composition of the essential oils of Rosmarinus officinalis of ten populations from the Balkan Peninsula were determined by GC/FID and GC/MS. The main constituents were 1,8-cineole, camphor, α-pinene, and borneol. Multivariate statistical analysis (UPGMA cluster analysis and principal-component analysis (PCA)) revealed two major types of rosemary oil, i.e., 1,8-cineole and camphor-type, and two intermediate types, i.e., camphor/1,8-cineole/borneol type and 1,8-cineole/camphor type. The regression analyses (simple linear regression and stepwise multiple regression) have shown that, with respect to basic geographic, orographic, and 19 bioclimatic characteristics of each population, bioclimatic factor temperature of habitat represented the dominant abiogenetic factor, which, in chemical sense, led to differentiation of populations in the studied region. Also, the regression analysis have shown that some constituents of essential oils are independent of any single bioclimatic factors. However, some constituents display statistically significant correlations with some abiotic factors.     

Analysis of the compressive strain below the removable and fixed prosthesis in the posterior mandible using a digital image correlation method

It was the purpose of this study to determine and analyse strains in the bone of posterior mandible below the removable and fixed partial dentures using Digital Image Correlation Method. Dried mandible with shortened dental arch (Kennedy Class 1) was used in the experiment. The mandible model was prepared for accepting two types of restorations for bilaterally missing molars conventional therapy, and removable and fixed partial dentures were manufactured following standard prosthetic protocol. The models with prosthetic restorations placed in situ were subjected to loading of 50-300 N, and photographed using two digital cameras as part of the digital image correlation method equipment. Afterwards, the obtained data for strains within restored mandible during loading ciclus were analysed in the software Aramis and graphically presented. Percentage size of the mandible strains within the line section are from 0.14 to 0.19% for the removable partial denture experimental model and 0-0.14% for the fixed partial denture experimental model. The study has demonstrated that Digital Image Correlation method can be used to measure strain on the mandible surface and replacements during loading and that from biomechanical perspective both therapeutic modalities can be equally useful for the restoration of the mandible with bilaterally distal edentulous spaces.     

Effect of cytochrome c concentration on the ultrastructural appearance of bovine nasal cartilage proteoglycans

Bovine nasal cartilage proteoglycan monomers were studied by Kleinschmidt and Zahn's molecular spreading technique as modified by Rosenberg et al. By decreasing the cytochrome c concentration in the epiphase to 2 micrograms per 100 microliters we were able on nitrocellulose-coated grids routinely to obtain highly contrasted and well spread proteoglycan monomers with a characteristic brush-like appearance and, sometimes, a clearly distinguishable hyaluronic acid binding region. Previously, a hyaluronic acid binding region has only been observed routinely in spread proteoglycan aggregates, and a brush-like structure of proteoglycan monomers on carbon-coated grids, but with considerably less precision due to the poor contrast of the molecules. Molecular spreading was further improved by decreasing the cytochrome c concentration in the epiphase to less than 2 micrograms per 100 microliters, but contrast was reduced making visualization of molecular details difficult.     

Degradation of Hyaluronic Acid by Photosensitized Riboflavin In Vitro. Modulation of the Effect by Transition Metals, Radical Quenchers, and Metal Chelators

The effect of photoexcited riboflavin (RF) on the viscosity of hyaluronic acid (HA) solutions has been investigated. UV irradiation of RF causes under aerobic conditions fragmentation of HA and a decrease in the viscosity of its solutions. A decrease of HA viscosity occurs in PO₄-buffered solutions and is accelerated by high pH, Fe²⁺ (but much less so by Fe³⁺), certain metal chelators, and horseradish peroxidase (HRP); it is partially inhibited by catalase and less so by superoxide dismutase (SOD). The reactivity of the system was completely blocked by Tris, ethanol, aspirin, d-manitol, dimethylthiourea (DMTU), dimethylsulfoxide (DMSO), and sodium azide. These results indicate that the most likely chemical species involved in the reaction is the hydroxyl radical. Singlet oxygen (¹0₂) generation is suggested by the ability of NaN₃ and DMSO to completely inhibit the reactivity of the system. These two agents, however, may also interact with OH^√ radical, as well and suppress the reactivity of the system. H₂O₂ and seem also to be produced in significant amounts, because catalase and SOD partially block the reactivity of the system. The effect of HRP may be due to hydrogen subtraction from HA and H₂O₂ reduction to water. Photoexcitation of RF may potentially occur in vitro and in vivo in the organs and tissues that are permeable to light, such as the eye or skin, and damage HA and other cell-matrix components causing inflammation and accelerating aging.  © 1997 Elsevier Science Inc.     

Variations in Chemical Composition,Vasorelaxant and Angiotensin I‐Converting Enzyme Inhibitory Activities of Essential Oil from Aerial Parts of Seseli pallasii Besser (Apiaceae)

The present paper describes environmental and seasonal‐related chemical composition variations, vasorelaxant and angiotensin I‐converting enzyme (ACE) activities of essential oil from aerial parts of Seseli pallasii Besser . The composition was analyzed by GC and GC/MS. Monoterpenes were found to be the most abundant chemical class with α ‐pinene (42.7 – 48.2%) as the most prevalent component. Seseli pallasi essential oil relaxed isolated endothelium‐intact mesenteric arteries rings precontracted with phenylephrine with IC ₅₀ = 3.10 nl/ml (IC ₅₀ = 2.70 μg/ml). Also, S. pallasii essential oil was found to exhibit a dose‐dependent ACE inhibitory activity with an IC ₅₀ value of 0.33 mg/ml. In silico evaluation of ACE inhibitory activity of the individual components showed that spathulenol exhibited the best binding affinity with ACE, and the lowest binding energy of ?7.5 kcal/mol. The results suggested that combination of vasorelaxing and ACE inhibitory effects of the analyzed S. pallasii essential oil might have the potential therapeutic significance in hypertension.