53 research outputs found

    Identification of novel cytosolic thioredoxin-1 target proteins in mammalian cells by mechanism-based kinetic trapping

    Get PDF
    Reactive oxygen species (ROS) have been reported to be locally produced after stimulation of various transmembrane receptors, including those for cytokines, growth factors and hormones. Transient ROS generation leads to the reversible oxidation of redox-sensitive proteins, which may either result in their transient activation or inactivation. Even though the role of ROS as a signal transducer is widely accepted, little is known about the identity of redox-sensitive proteins and the reduction mechanism by which they are re-generated. Thioredoxin-1 (Trx1) is an oxidoreductase known to influence a variety of cellular processes including proliferation, apoptosis and gene expression. In higher plants and cyanobacteria different proteomic approaches allowed for the identification of various thioredoxin target proteins. However, no comprehensive study of Trx1 interactions in the cytosol of mammalian cells has been performed so far. In this thesis, mechanism-based kinetic trapping was applied to identify proteins forming mixed disulfide intermediates with Trx1 in the cytosol of a human T cell leukemia line. Most previously established target proteins of Trx1 could be identified, including ribonucleotide reductase, peroxiredoxins and annexin-2, thus confirming the validity of the approach. Interestingly, a substantial number of newly identified proteins currently lacks functional annotation, suggesting that several thioredoxin-regulated pathways still await initial characterization. Of those newly identified proteins with known function, a significant portion is associated with cell cycle control and regulation of apoptosis, while others participate in various signal transduction pathways, cytoskeleton and membrane dynamics, metabolism and transcriptional control. These results strongly support the long-held belief that Trx1 not only plays a role in ROS scavenging and reductive metabolism but is also extensively involved in interactions with key regulatory proteins associated with cellular behavior and fate. While Trx1-interactions are clearly pleiotropic in that they affect a variety of processes simultaneously, we have found strong evidence that they are nevertheless highly target specific. The newly identified Trx1 target proteins cdk6 and caspase-2 were selected for further study. For cdk6 the thioredoxin-interacting cysteine residue was identified and for caspase-2 redox regulation of activity by Trx1 could be demonstrated in vitro, lending further support to the biological relevance of Trx-based regulation

    The Association of NOV/CCN3 With Obstructive Sleep Apnea (OSA): Preliminary Evidence of a Novel Biomarker in OSA

    Get PDF
    Obstructive sleep apnea (OSA) has a strong association with cardiovascular and metabolic abnormalities, although the mechanism driving this association is not well established. NOV/CCN3, a multifunctional extracellular matrix protein, may play a mechanistic and/or prognostic role in these associations. We hypothesized that patients with OSA, which primarily affects obese individuals, will have increased levels of NOV, and that NOV can serve as a biomarker in patients to predict OSA as well as metabolic and cardiac risk. Ten morbidly obese and 10 healthy lean subjects underwent overnight polysomnography (PSG) and clinical evaluation. Blood samples were analyzed for NOV levels, adiponectin and IL-6. OSA was found in nine obese subjects and three lean subjects. NOV levels were significantly higher in the OSA vs. no OSA group (2.1 +/- 0.9 vs. 1.3 +/- 0.8, p \u3c 0.03). NOV levels were significantly higher in the obese vs. lean group (2.2 +/- 0.3 vs. 1.4 +/- 0.2-fold change, p \u3c 0.03). Among lean subjects, NOV levels were significantly higher in the OSA vs. no OSA group (2.1 +/- 0.9 vs. 1.0 +/- 0.4, p \u3c 0.05). NOV and AHI were positively correlated (rho = 0.49, p = 0.033). IL-6 and adiponectin differences in obese vs. lean and OSA vs. no OSA were consistent with an inflammatory phenotype in obese subjects and OSA subjects. NOV is a novel biomarker of the presence and severity of OSA and a potential marker of future cardiovascular and metabolic disease in OSA patients

    High throughput surface structuring with ultrashort pulses in synchronized mode with fast polygon line scanner

    Get PDF
    High precision laser micromachining requires an exact synchronization of the laser pulse train with the mechanical axes of the motion system to ensure for each single pulse a precise control of the laser spot position - on the target. For ultra short pulsed laser systems this was already demonstrated with a conventional two-axis galvanometer scanner. But this solution is limited by the scanner architecture to a marking speed of about 10m/s with a maximum scan line length of about 100mm. It is therefore not suited for average powers far beyond 10W when working at the optimum point with highest removal rate and machining quality is desired. A way to overcome this limitation is offered by polygon line scanners which are able to realize much higher lateral speeds at large scan line lengths. In this work we will report on the results with a polygon line scanner having a maximum moving spot velocity of 100m/s, a scan line length of 170mm, spot diameters of 45”m (1064nm) and 22”m (532nm) together with a 50W, 10-ps laser system. The precise control of the laser spot position i.e. the synchronization is realized via the new SuperSyncTM technology. Decoating, perforation and 3D patterning will act as benchmark processes to evaluate this scanning technology

    Laser surface structuring with 100W of average power and sub-ps pulses

    Get PDF
    High throughput still represents a key factor for industrial use of ultrashort pulses in the ïŹeld of surface structuring. Reliable systems with average powers up to 100W are today available. It has already been proved that metals, especially steel having a low threshold ïŹ‚uence, can be machined with excellent surface quality at average powers of more than 40W and a spot radius of about 25lm, if a polygon line scanner, offering fast scanning speeds, is used. A further scale-up into the 100W regime should be possible for metals showing a threshold ïŹ‚uence of about 0.2 J/cm2 or higher. But, it will lead to problems with heat accumulation in the case of steel and a straight forward scale-up is not possible. In order to keep a good surface quality, the machining strategy has to be adapted. A maximum ïŹ‚exibility can be obtained with an “interlaced” mode by using very high marking speeds of several 100m/s and repetition rates of several tenths of MHz. As this is at the edge of today available technologies, alternative strategies are additionally investigated. Enlarging the spot size represents the most simple approach to reduce the heat accumulation in the case of steel but also multispots represent an attractive alternative

    Đ Đ°Đ·Ń€Đ°Đ±ĐŸŃ‚ĐșĐ° Ń‚Đ”Ń…ĐœĐŸĐ»ĐŸĐłĐžŃ‡Đ”ŃĐșĐŸĐłĐŸ ĐżŃ€ĐŸŃ†Đ”ŃŃĐ° ĐžĐ·ĐłĐŸŃ‚ĐŸĐČĐ»Đ”ĐœĐžŃ ĐŸĐżĐŸŃ€Ń‹ ĐŽĐČĐžĐłĐ°Ń‚Đ”Đ»Ń

    Get PDF
    ВыпусĐșĐœĐ°Ń ĐșĐČалОфОĐșĐ°Ń†ĐžĐŸĐœĐœĐ°Ń Ń€Đ°Đ±ĐŸŃ‚Đ° ŃĐŸŃŃ‚ĐŸĐžŃ‚ Оз 4 Ń€Đ°Đ·ĐŽĐ”Đ»ĐŸĐČ. В ĐșачДстĐČĐ” Đ·Đ°ĐŽĐ°ĐœĐžŃ был ĐżĐŸĐ»ŃƒŃ‡Đ”Đœ чДртёж ЎДталО ĐŽĐ»Ń ĐșĐŸŃ‚ĐŸŃ€ĐŸĐč Ń€Đ°Đ·Ń€Đ°Đ±ĐŸŃ‚Đ°Đœ Ń‚Đ”Ń…ĐœĐŸĐ»ĐŸĐłĐžŃ‡Đ”ŃĐșĐžĐč ĐŒĐ°Ń€ŃˆŃ€ŃƒŃ‚ ĐžĐ·ĐłĐŸŃ‚ĐŸĐČĐ»Đ”ĐœĐžŃ. В Ń‚Đ”Ń…ĐœĐŸĐ»ĐŸĐłĐžŃ‡Đ”ŃĐșĐŸĐŒ разЎДлД ĐŽĐ°ĐœŃ‹ расчёты Đž ĐżĐŸŃŃĐœĐ”ĐœĐžŃ ĐŽĐ»Ń ĐŸĐ±Đ”ŃĐżĐ”Ń‡Đ”ĐœĐžŃ Ń‚Ń€Đ”Đ±ĐŸĐČĐ°ĐœĐžĐč, Đ·Đ°ĐŽĐ°ĐœĐœŃ‹Ń… ĐșĐŸĐœŃŃ‚Ń€ŃƒĐșŃ‚ĐŸŃ€ĐŸĐŒ. В ĐșачДстĐČĐ” Đ·Đ°ĐłĐŸŃ‚ĐŸĐČĐșĐž ĐČŃ‹Đ±Ń€Đ°Đœ ĐșŃ€ŃƒĐłĐ»Ń‹Đč ĐżŃ€ĐŸĐșат Đ°Đ»ŃŽĐŒĐžĐœĐžĐ”ĐČĐŸĐłĐŸ сплаĐČĐ° Д16Đą. В ĐșĐŸĐœŃŃ‚Ń€ŃƒĐșŃ‚ĐŸŃ€ŃĐșĐŸĐŒ разЎДлД ŃĐżŃ€ĐŸĐ”ĐșŃ‚ĐžŃ€ĐŸĐČĐ°ĐœĐŸ ĐżŃ€ĐžŃĐżĐŸŃĐŸĐ±Đ»Đ”ĐœĐžŃ ĐŽĐ»Ń сĐČĐ”Ń€Đ»Đ”ĐœĐžŃ ĐŸŃ‚ĐČДрстОĐč. В эĐșĐŸĐœĐŸĐŒĐžŃ‡Đ”ŃĐșĐŸĐŒ разЎДлД ĐČŃ‹ĐżĐŸĐ»ĐœĐ”ĐœĐžŃ расчёт ŃŃ‚ĐŸĐžĐŒĐŸŃŃ‚Đž ЎДталО. В разЎДлД ŃĐŸŃ†ĐžĐ°Đ»ŃŒĐœĐŸĐč ĐŸŃ‚ĐČДтстĐČĐ”ĐœĐœĐŸŃŃ‚Đž Đž Đ±Đ”Đ·ĐŸĐżĐ°ŃĐœĐŸŃŃ‚Đž Đ¶ĐžĐ·ĐœĐ”ĐŽĐ”ŃŃ‚Đ”Đ»ŃŒĐœĐŸŃŃ‚Đž проĐČĐ”ĐŽĐ”ĐœŃ‹ ĐŸŃĐœĐŸĐČĐœŃ‹Đ” Ń‚Ń€Đ”Đ±ĐŸĐČĐ°ĐœĐžŃ ĐŽĐ»Ń Đ±Đ”Đ·ĐŸĐżĐ°ŃĐœĐŸĐč Ń€Đ°Đ±ĐŸŃ‚Ń‹ ĐŸĐżĐ”Ń€Đ°Ń‚ĐŸŃ€Đ° Đ·Đ° ŃŃ‚Đ°ĐœĐșĐŸĐŒ.This work is devoted to creation of technological process of the part "engine bracket" and consist of 4 parts. The first part is considering sequence of machining workpiece, calculation of operational time and cutting conditions. The second part is devoted to special device, which helps drilling accurate holes. The third and the forth parts are economical (where counting of the price is making) and social responsibility (where norms of pollution for workers and environment are calculated)

    Single-laser 32.5 Tbit/s Nyquist WDM transmission

    Full text link
    We demonstrate 32.5 Tbit/s 16QAM Nyquist WDM transmission over a total length of 227 km of SMF-28 without optical dispersion compensation. A number of 325 optical carriers are derived from a single laser and encoded with dual-polarization 16QAM data using sinc-shaped Nyquist pulses. As we use no guard bands, the carriers have a spacing of 12.5 GHz equal to the Nyquist bandwidth of the data. We achieve a high net spectral efficiency of 6.4 bit/s/Hz using a software-defined transmitter which generates the electrical modulator drive signals in real-time.Comment: (c) 2012 Optical Society of America. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibite

    Selective redox regulation of cytokine receptor signaling by extracellular thioredoxin-1

    Get PDF
    The thiol-disulfide oxidoreductase thioredoxin-1 (Trx1) is known to be secreted by leukocytes and to exhibit cytokine-like properties. Extracellular effects of Trx1 require a functional active site, suggesting a redox-based mechanism of action. However, specific cell surface proteins and pathways coupling extracellular Trx1 redox activity to cellular responses have not been identified so far. Using a mechanism-based kinetic trapping technique to identify disulfide exchange interactions on the intact surface of living lymphocytes, we found that Trx1 catalytically interacts with a single principal target protein. This target protein was identified as the tumor necrosis factor receptor superfamily member 8 (TNFRSF8/CD30). We demonstrate that the redox interaction is highly specific for both Trx1 and CD30 and that the redox state of CD30 determines its ability to engage the cognate ligand and transduce signals. Furthermore, we confirm that Trx1 affects CD30-dependent changes in lymphocyte effector function. Thus, we conclude that receptor–ligand signaling interactions can be selectively regulated by an extracellular redox catalyst

    Sex difference and intra-operative tidal volume: Insights from the LAS VEGAS study

    Get PDF
    BACKGROUND: One key element of lung-protective ventilation is the use of a low tidal volume (VT). A sex difference in use of low tidal volume ventilation (LTVV) has been described in critically ill ICU patients.OBJECTIVES: The aim of this study was to determine whether a sex difference in use of LTVV also exists in operating room patients, and if present what factors drive this difference.DESIGN, PATIENTS AND SETTING: This is a posthoc analysis of LAS VEGAS, a 1-week worldwide observational study in adults requiring intra-operative ventilation during general anaesthesia for surgery in 146 hospitals in 29 countries.MAIN OUTCOME MEASURES: Women and men were compared with respect to use of LTVV, defined as VT of 8 ml kg-1 or less predicted bodyweight (PBW). A VT was deemed 'default' if the set VT was a round number. A mediation analysis assessed which factors may explain the sex difference in use of LTVV during intra-operative ventilation.RESULTS: This analysis includes 9864 patients, of whom 5425 (55%) were women. A default VT was often set, both in women and men; mode VT was 500 ml. Median [IQR] VT was higher in women than in men (8.6 [7.7 to 9.6] vs. 7.6 [6.8 to 8.4] ml kg-1 PBW, P < 0.001). Compared with men, women were twice as likely not to receive LTVV [68.8 vs. 36.0%; relative risk ratio 2.1 (95% CI 1.9 to 2.1), P < 0.001]. In the mediation analysis, patients' height and actual body weight (ABW) explained 81 and 18% of the sex difference in use of LTVV, respectively; it was not explained by the use of a default VT.CONCLUSION: In this worldwide cohort of patients receiving intra-operative ventilation during general anaesthesia for surgery, women received a higher VT than men during intra-operative ventilation. The risk for a female not to receive LTVV during surgery was double that of males. Height and ABW were the two mediators of the sex difference in use of LTVV.TRIAL REGISTRATION: The study was registered at Clinicaltrials.gov, NCT01601223
    • 

    corecore