p47phox, the phagocyte NADPH oxidase/NOX2 organizer: structure, phosphorylation and implication in diseases

Jamel El-Benna,Pham My-Chan Dang,Marie-Anne Gougerot-Pocidalo,Jean-Claude Marie,Françoise Braut-Boucher 생화학분자생물학회 2009 Experimental and molecular medicine Vol.41 No.4

Phagocytes such as neutrophils play a vital role in host defense against microbial pathogens. The anti-microbial function of neutrophils is based on the production of superoxide anion (O2 -), which generates other microbicidal reactive oxygen species (ROS) and release of antimicrobial peptides and proteins. The enzyme responsible for O2 - production is called the NADPH oxidase or respiratory burst oxidase. This multicomponent enzyme system is composed of two transmembrane proteins (p22phox and gp91phox, also called NOX2, which together form the cytochrome b558) and four cytosolic proteins (p47phox, p67phox, p40phox and a GTPase Rac1 or Rac2), which assemble at membrane sites upon cell activation. NADPH oxidase activation in phagocytes can be induced by a large number of soluble and particulate agents. This process is dependent on the phosphorylation of the cytosolic protein p47phox. p47phox is a 390 amino acids protein with several functional domains: one phox homology (PX) domain, two src homology 3 (SH3) domains, an auto-inhibitory region (AIR), a proline rich domain (PRR) and has several phosphorylated sites located between Ser303 and Ser379. In this review, we will describe the structure of p47phox, its phosphorylation and discuss how these events regulate NADPH oxidase activation. Phagocytes such as neutrophils play a vital role in host defense against microbial pathogens. The anti-microbial function of neutrophils is based on the production of superoxide anion (O2 -), which generates other microbicidal reactive oxygen species (ROS) and release of antimicrobial peptides and proteins. The enzyme responsible for O2 - production is called the NADPH oxidase or respiratory burst oxidase. This multicomponent enzyme system is composed of two transmembrane proteins (p22phox and gp91phox, also called NOX2, which together form the cytochrome b558) and four cytosolic proteins (p47phox, p67phox, p40phox and a GTPase Rac1 or Rac2), which assemble at membrane sites upon cell activation. NADPH oxidase activation in phagocytes can be induced by a large number of soluble and particulate agents. This process is dependent on the phosphorylation of the cytosolic protein p47phox. p47phox is a 390 amino acids protein with several functional domains: one phox homology (PX) domain, two src homology 3 (SH3) domains, an auto-inhibitory region (AIR), a proline rich domain (PRR) and has several phosphorylated sites located between Ser303 and Ser379. In this review, we will describe the structure of p47phox, its phosphorylation and discuss how these events regulate NADPH oxidase activation.

Micro-PIV measurements of flows induced by rotating microparticles near a boundary

Ali, Jamel,Kim, Hoyeon,Cheang, U. Kei,Kim, Min Jun SPRINGER 2016 MICROFLUIDICS AND NANOFLUIDICS Vol.20 No.9

Chimerism of Multiple Monoclonal Antibodies Expressed in a Single Plant

Arshad Jamel,이정환,이경진,오두병,김득수,이경기,추영국,황경아,고기성 한국원예학회 2012 Horticulture, Environment, and Biotechnology Vol.53 No.6

Transgenic plants offer a source for the sustainable, safe, and large-scale production of therapeutic recombinant proteins. In this study, both murine anti-colorectal cancer mAb (mAbMC) and human anti-rabies mAb 57 (mAbHR),expressed in a single plant were investigated for their cancer cell binding activity and rabies virus neutralization activity, respectively. Transgenic plants, expressing murine anti-colorectal cancer mAb CO17-1A (mAbMC) and human anti-rabies mAb 57 (mAbHR), respectively, were crossed to reproduce F1 transgenic plant, expressing both mAbs. PCR and immunoblot analyses demonstrated that heavy (HC) and light chain (LC) genes of mAbMC and mAbHR were present, and that both mAbs were expressed in F1 transgenic lines, respectively. Quantitative immunoblot for purified mAb also showed the presence of both mAbs in F1 transgenic lines. However, Cell ELISA analysis showed that in mAbPC and mAbPR purified from the F1 transgenic lines (mAbPC×R), the binding activity to SW948 human colorectal carcinoma cells was lower than mAbMC, and in vitro mAbMC, mixed with mAbHR (mAbMHC+R). The in vitro rabies virus neutralization assay demonstrated that the mAbPC×R, from the F1 transgenic plants, had lower bioactivity against rabies virus than mAbH57, and mAbMHC+R. N-glycan structure analysis revealed that mAbMC and mAbHR had Golgi type (94 and 14%) and ER type (6 and 86%), respectively, and the purified mAbs from the F1transgenic plants had Golgi type (75%) and ER type (25%). These results indicate that the F1 transgenic plant produced both mAbPC and mAbPR; however, the HC and LC proteins of each anti-rabies virus and anti-colorectal cancer mAbs were assembled randomly, resulting in chimerism in HC and LC assembly for mAb.

Investigation of Bacterial Chemotaxis Using a Simple Three- Point Microfluidic System

김호연,Jamel Ali,Kiran Phuyal,박성수,김민준 한국바이오칩학회 2015 BioChip Journal Vol.9 No.1

A three-point microfluidic system was developedand used to experimentally verify bacterialchemotaxis with known chemoeffectors. Using pneumatically-controlled micro-valves, the device was ableto regulate microscale flows and created concentrationgradients that allowed GFP-labelled Escherichia colicells to interact with an environment that contained achemoattractant and a chemorepellent. Having two separatepossible paths (left and right) for the bacteria tomove forward, this device also allowed for imagingprocessing based removal of noisy data, if adirectionalbias was present. This device could be useful for quantitativeanalysis of chemotactic behaviors with minimaltechnical requirements, and could motivate thedevelopment of future devices based on this concept.

Measurement and simulation of pollutant emissions from marine diesel combustion engine and their reduction by exhaust gas recirculation

Nader Larbi,Jamel Bessrour 대한기계학회 2008 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.22 No.11

Taking into account the complexity and cost of a direct experimental approach, the recourse to simulation, which can also predict inaccessible information by measurement, offers an effective and fast alternative to apprehend the problem of pollutant emissions from internal combustion engines. An analytical model based on detailed chemical kinetics employed to calculate the pollutant emissions of a marine Diesel engine in general gave satisfactory results compared to experimentally measured results. Especially, the nitric oxide (NO) emission values were found to be higher than the limiting values tolerated by the International Maritime Organization (IMO). Thus, this study was undertaken to reduce to the maximum these emissions. The reduction of pollutant emissions is apprehended with exhaust gas recirculation (EGR).

An extended finite element method for modeling elastoplastic FGM plate-shell type structures

Hanen Jrad,Jamel Mars,Mondher Wali,Fakhreddine Dammak 국제구조공학회 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.68 No.3

In this paper, an extended finite element method is proposed to analyze both geometric and material non-linear behavior of general Functionally Graded Material (FGM) plate-shell type structures. A user defined subroutine (UMAT) is developed and implemented in Abaqus/Standard to study the elastoplastic behavior of the ceramic particle-reinforced metal-matrix FGM plates-shells. The standard quadrilateral 4-nodes shell element with three rotational and three translational degrees of freedom per node, S4, is extended in the present study, to deal with elasto-plastic analysis of geometrically non-linear FGM plate-shell structures. The elastoplastic material properties are assumed to vary smoothly through the thickness of the plate-shell type structures. The nonlinear approach is based on Mori-Tanaka model to underline micromechanics and locally determine the effective FGM properties and self-consistent method of Suquet for the homogenization of the stress-field. The elasto-plastic behavior of the ceramic/metal FGM is assumed to follow Ludwik hardening law. An incremental formulation of the elasto-plastic constitutive relation is developed to predict the tangent operator. In order to to highlight the effectiveness and the accuracy of the present finite element procedure, numerical examples of geometrically non-linear elastoplastic functionally graded plates and shells are presented. The effects of the geometrical parameters and the volume fraction index on nonlinear responses are performed.

An extended finite element method for modeling elastoplastic FGM plate-shell type structures

Jrad, Hanen,Mars, Jamel,Wali, Mondher,Dammak, Fakhreddine Techno-Press 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.68 No.3

In this paper, an extended finite element method is proposed to analyze both geometric and material non-linear behavior of general Functionally Graded Material (FGM) plate-shell type structures. A user defined subroutine (UMAT) is developed and implemented in Abaqus/Standard to study the elastoplastic behavior of the ceramic particle-reinforced metal-matrix FGM plates-shells. The standard quadrilateral 4-nodes shell element with three rotational and three translational degrees of freedom per node, S4, is extended in the present study, to deal with elasto-plastic analysis of geometrically non-linear FGM plate-shell structures. The elastoplastic material properties are assumed to vary smoothly through the thickness of the plate-shell type structures. The nonlinear approach is based on Mori-Tanaka model to underline micromechanics and locally determine the effective FGM properties and self-consistent method of Suquet for the homogenization of the stress-field. The elasto-plastic behavior of the ceramic/metal FGM is assumed to follow Ludwik hardening law. An incremental formulation of the elasto-plastic constitutive relation is developed to predict the tangent operator. In order to to highlight the effectiveness and the accuracy of the present finite element procedure, numerical examples of geometrically non-linear elastoplastic functionally graded plates and shells are presented. The effects of the geometrical parameters and the volume fraction index on nonlinear responses are performed.

Numerical model for bolted T-stubs with two bolt rows

Daidie, Alain,Chakhari, Jamel,Zghal, Ali Techno-Press 2007 Structural Engineering and Mechanics, An Int'l Jou Vol.26 No.3

This article presents a numerical tool for dimensioning two-threaded fasteners connecting prismatic parts subjected to fatigue tension loads that are coplanar with the screw axis. A simplified numerical model is developed from unidirectional finite elements, modeling the connected parts and screws with bent elements and the elastic contact layer between the parts with springs. An algorithm updating the contact stiffness matrix, calculating forces and displacements at each node of the structure and thus normal stresses in the screws in both static and fatigue is further developed using C language. An experimental study is also conducted in parallel with the numerical approach to validate the developed model assumptions, the numerical model and the 3D finite element results. Since stiffness values for the compressive zones in the parts are analytically difficult to determine, a statistical software method is used, from which a tuning factor is derived for identifying these stiffness values. The method is also applied to set out the influence of each parameter on the fatigue behaviour of each screw. Finally, the developed model will be used to establish a new, sophisticated, fast and accurate tool for dimensioning bolted mechanical structures.

Micro manipulation using magnetic microrobots

Kim, Hoyeon,Ali, Jamel,Cheang, U. Kei,Jeong, Jinwoo,Kim, Jin Seok,Kim, Min Jun Springer-Verlag 2016 Journal of bionic engineering Vol.13 No.4

<P>When developing microscale robotic systems it is desired that they are capable of performing microscale tasks such as small scale manipulation and transport. In this paper, we demonstrate the transport of microscale objects using single or multiple microrobots in low Reynolds number fluidic environment. The microrobot is composed of a 'U' shaped SU-8 body, coated on one side with nickel. Once the nickel coating is magnetized, the motion of the microrobots can be driven by external magnetic fields. To invoke different responses from two microrobots under a global magnetic field, two batches of microrobots were fabricated with different thicknesses of nickel coating as a way to promote heterogeneity within the microrobot population. The heterogeneity in magnetic content induces different spatial and temporal responses under the same control input, resulting in differences in movement speed. The nickel coated microstructure is manually controlled through a user interface developed using C++. This paper presents a control strategy to navigate the microrobots by controlling the direction and strength of externally applied magnetic field, as well as orientation of the microrobots based on their polarity. In addition, multiple micro robots are used to perform transport tasks.</P>

Has the 'Franc Fort' Exchange Rate Policy Affected the Inflationary Dynamics? Theory and New Evidence

Mo?se Sidiropoulos,Jamel Trabelsi,Costas Karfakis 한국국제경제학회 2005 International Economic Journal Vol.19 No.3