Molecular Basis Underlying (molecular + basis_underlying)

Distribution by Scientific Domains


Selected Abstracts


Man1, an inner nuclear membrane protein, regulates left,right axis formation by controlling nodal signaling in a node-independent manner

DEVELOPMENTAL DYNAMICS, Issue 12 2008
Akihiko Ishimura
Abstract Man1, an inner nuclear membrane protein, regulates transforming growth factor , signaling by interacting with receptor-associated Smads. In Man1 -deficient (Man1,/,) embryos, vascular remodeling is perturbed by misregulation of Smad activity. Here, we show that Man1,/, embryos exhibit abnormal heart morphogenesis including the looping abnormality. We searched for the molecular basis underlying the heart abnormalities and found that the left side-specific genes responsible for left,right (LR) asymmetry, Nodal, Lefty2, and Pitx2, were expressed bilaterally in the lateral plate mesoderm and that their expression was enhanced significantly in mutants. Notably, Lefty1, a marker for the midline barrier, was maintained in Man1,/, mutants. Crossing Man1,/+ with Nodal hypomorphs (Nodalneo/+), in which Nodal signaling in the node is disrupted, to generate double homozygous embryos (Man1,/,; Nodalneo/neo) revealed that the bilateral Nodal was retained in Man1,/,; Nodalneo/neo embryos. These results suggest that Man1 regulates LR asymmetry by controlling Nodal signaling in a node-independent manner. Developmental Dynamics 237:3565,3576, 2008. © 2008 Wiley-Liss, Inc. [source]


Production, purification, crystallization and preliminary X-ray diffraction analysis of the HIV-2-neutralizing V3 loop-specific Fab fragment 7C8

ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 7 2009
Hannes Uchtenhagen
7C8 is a mouse monoclonal antibody that is specific for the third hypervariable loop (V3 loop) of the human immunodeficiency virus type 2 (HIV-2) associated protein gp125. Fab fragments of 7C8 effectively neutralize HIV-2. 7C8 was expressed and purified from a hybridoma cell line in order to establish the molecular basis underlying the specificity of the 7C8 antibody for the V3 loop as well as the specific role of the elongated third complementarity-determining region of the heavy chain (CDRH3). The antibody was digested with papain and Fab fragments were purified using size-exclusion chromatography. Hanging-drop vapour-diffusion crystallization techniques were employed and the protein was crystallized in 50,mM ammonium sulfate, 100,mM Tris,HCl pH 8.5, 25%(w/v) PEG 8000 and 2.5%(w/v) PEG 400 at 275,K. The analysed crystals belonged to the rhombohedral space group P3221, with unit-cell parameters a = b = 100.1, c = 196.8,Å, and diffracted to 2.7,Å resolution. [source]


Biological mechanisms of stroke prevention by physical activity in type 2 diabetes

ACTA NEUROLOGICA SCANDINAVICA, Issue 4 2009
V. Agosti
The principal modifiable risk factors for stroke are hypertension, diabetes mellitus, hypercholesterolaemia, hyperhomocysteinaemia, smoking and limited physical activity. However, it is not clear whether physical inactivity is a risk factor per se, or because it predisposes to pathological conditions that are risk factors for stroke. The limited availability of effective therapeutic approaches for stroke emphasizes the crucial role of prevention of risk factors. The global burden associated with type 2 diabetes is large and continues to grow. Convincing epidemiologic data support the role of physical activity in preventing type 2 diabetes. The increasing evidence of physical activity in preventing diabetic complications, including stroke, has generated interest in the molecular basis underlying these beneficial effects. The aim of the present review is to discuss the biological mechanisms underlying the effect of physical activity in preventing stroke in type 2 diabetes. [source]


Translational Mini-Review Series on Complement Factor H: Genetics and disease associations of human complement factor H

CLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 1 2008
S. Rodríguez De Córdoba
Summary Factor H is an abundant plasma glycoprotein that plays a critical role in the regulation of the complement system in plasma and in the protection of host cells and tissues from damage by complement activation. Several recent studies have described the association of genetic variations of the complement factor H gene (CFH) with atypical haemolytic uraemic syndrome (aHUS), age-related macular degeneration (AMD) and membranoproliferative glomerulonephritis (MPGN). This review summarizes our current knowledge of CFH genetics and examines the CFH genotype,phenotype correlations that are helping to understand the molecular basis underlying these renal and ocular pathologies. [source]


Heterogeneity in lipopolysaccharide responsiveness of endothelial cells identified by gene expression profiling: role of transcription factors

CLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2006
G. C. Beck
Summary Interindividual differences of endothelial cells in response to endotoxins might contribute to the diversity in clinical outcome among septic patients. The present study was conducted to test the hypothesis that endothelial cells (EC) with high and low proinflammatory potential exist and to dissect the molecular basis underlying this phenomenon. Thirty human umbilical vein endothelial cell (HUVEC) lines were stimulated for 24 h with lipopolysaccharide (LPS) and screened for interleukin (IL)-8 production. Based on IL-8 production five low and five high producers, tentatively called types I and II responders, respectively, were selected for genome-wide gene expression profiling. From the 74 genes that were modulated by LPS in all type II responders, 33 genes were not influenced in type I responders. Among the 41 genes that were increased in both responders, 17 were expressed significantly stronger in type II responders. Apart from IL-8, significant differences in the expression of proinflammatory related genes between types I and II responders were found for adhesion molecules [intercellular adhesion molecule (ICAM-1), E-selectin)], chemokines [monocyte chemoattractant protein (MCP-1), granulocyte chemotactic protein (GCP-2)], cytokines (IL-6) and the transcription factor CCAAT/enhancer binding protein-delta (C/EBP-,). Type I responders also displayed a low response towards tumour necrosis factor (TNF)-,. In general, maximal activation of nuclear factor (NF)-,B was achieved in type I responders at higher concentrations of LPS compared to type II responders. In the present study we demonstrate that LPS-mediated gene expression differs quantitatively and qualitatively in types I and II responders. Our results suggest a pivotal role for common transcription factors as a low inflammatory response was also observed after TNF-, stimulation. Further studies are required to elucidate the relevance of these findings in terms of clinical outcome in septic patients. [source]