The endometrial glands at various phases of the menstrual cycle (morphometric research)

In diagnostic curettages of the uterine cavity wall in 14 women 878 glands have been investigated. The following parameters have been estimated: perimeters of the gland section contours and their lumens, areas of the gland sections, their lumens and epithelial rings, coefficients of the gland forms and their lumens, distance between glands. Peculiarities connected with physiological differences of the uterine cavity mucose membrane are revealed at various phases of the ovarian menstrual cycle     

RGD mimetics containing phthalimidine fragment as novel ligands of fibrinogen receptor

The novel RGD mimetics with phthalimidine central fragment were synthesized with the use of 4-piperidine-4-yl-butyric, 4-piperidine-4-yl-benzoic, 4-piperazine-4-yl-benzoic and 1,2,3,4-tetrahydroisoquinoline-7-carboxylic acids as surrogates of Arg motif. The synthesized compounds potently inhibited platelet aggregation in vitro and blocked FITC-Fg binding to α(IIb)β(3) integrin in a suspension of washed human platelets. The key α(IIb)β(3) protein-ligand interactions were determined in docking experiments.     

ER Reorganization is Remarkably Induced in COS-7 Cells Accumulating Transmembrane Protein Receptors Not Competent for Export from the Endoplasmic Reticulum

The newly synthesized mutant L501fsX533 Frizzled-4 form and the alpha3beta4 nicotinic acetylcholine receptor expressed in the absence of nicotine accumulate in the endoplasmic reticulum of COS-7 cells and induce the formation of large areas of smooth and highly convoluted cisternae. This results in a generalized block of the transport to the Golgi complex of newly synthesized proteins. Intriguingly, both effects happen peculiarly in COS-7 cells; HeLa, Huh-7, and HEK293 cells expressing the two receptors at similar level than COS-7 cells show normal ER and normal transport toward the plasma membrane. These results question the conclusion that a dominant-negative mechanism would explain the dominance of the mutant L501fsX533 Fz4 allele in the transmission of a form of Familial exudative vitreoretinopathy. Moreover, they indicate that the coordination of endoplasmic reticulum homeostasis in COS-7 cells is particularly error prone. This finding suggests that COS-7 cells may be extremely useful to study the molecular mechanisms regulating endoplasmic reticulum size and architecture.     

Correlations between clusters of protein-DNA binding sites and the binding experimental data allow predicting a structure of regulatory modules

Here we analyzed an option to predict the structure of cis-regulatory modules that consist of binding sites of different proteins (heterogeneous cis-regulatory modules) using mutual positional correlations between protein-DNA binding experimental data and computationally identified clusters of binding sites for each of the proteins.     

Correlation of 4Pi and Electron Microscopy to Study Transport Through Single Golgi Stacks in Living Cells with Super Resolution

Two problems have hampered the use of light microscopy for structural studies of cellular organelles for a long time: the limited resolution and the difficulty of obtaining true structural boundaries from complex intensity curves. The advent of modern high-resolution light microscopy techniques and their combination with objective image segmentation now provide us with the means to bridge the gap between light and electron microscopy in cell biology applications. In this study, we provide the first comparative correlative analysis of three-dimensional structures obtained by 4Pi microscopy and segmented by a zero-crossing procedure with those of transmission electron microscopy (TEM). The distribution within the cisternae of isolated Golgi stacks of the cargo protein procollagen 3 was mapped by both 4Pi microscopy and TEM for a detailed comparative analysis of their imaging capabilities. A high correlation was seen for the structures, indicating the particular accuracy of the 4Pi microscopy. Furthermore, for the first time, transport of a cargo molecule (vesicular stomatitis virus G protein-pEGFP) through individual Golgi stacks (labeled by galactosyl transferase-venusYFP) was visualized by 4Pi microscopy. Following the procedures validated by the correlative analysis, our transport experiments show that (i) VSVG-pEGFP rapidly enter/exit individual Golgi stacks, (ii) VSVG-pEGFP never fills the GalT-venusYFP compartments completely and (iii) the GalT-venusYFP compartment volume increases upon VSVG-pEGFP arrival. This morphological evidence supports some previous TEM-based observations of intra-Golgi transport of VSVG-pEGFP and provides new insights toward a better understanding of protein progression across Golgi stacks. Our study thus demonstrates the general applicability of super-resolution fluorescence microscopy, coupled with the zero-crossing segmentation procedure, for structural studies of suborganelle protein distributions under living cell conditions.     

T-cell antigen receptor-induced signaling complexes: internalization via a cholesterol-dependent endocytic pathway

T-cell antigen receptor engagement causes the rapid assembly of signaling complexes. The adapter protein SLP-76, detected as SLP-yellow fluorescent protein, initially clustered with the TCR and other proteins, then translocated medially on microtubules. As shown by total internal reflection fluorescence microscopy and the inhibition of SLP-76 movement at 16 degrees C, this movement required endocytosis. Immunoelectron microscopy showed SLP-76 staining of smooth pits and tubules. Cholesterol depletion decreased the movement of SLP-76 clusters, as did coexpression of the ubiquitin-interacting motif domain from eps15. These data are consistent with the internalization of SLP-76 via a lipid raft-dependent pathway that requires interaction of the endocytic machinery with ubiquitinylated proteins. The endocytosed SLP-76 clusters contained phosphorylated SLP-76 and phosphorylated LAT. The raft-associated, transmembrane protein LAT likely targets SLP-76 to endocytic vesicles. The endocytosis of active SLP-76 and LAT complexes suggests a possible mechanism for downregulation of signaling complexes induced by TCR activation.     

A traffic-activated Golgi-based signalling circuit coordinates the secretory pathway

As with other complex cellular functions, intracellular membrane transport involves the coordinated engagement of a series of organelles and machineries; however, the molecular basis of this coordination is unknown. Here we describe a Golgi-based signalling system that is activated by traffic and is involved in monitoring and balancing trafficking rates into and out of the Golgi complex. We provide evidence that the traffic signal is due to protein chaperones that leave the endoplasmic reticulum and reach the Golgi complex where they bind to the KDEL receptor. This initiates a signalling reaction that includes the activation of a Golgi pool of Src kinases and a phosphorylation cascade that in turn activates intra-Golgi trafficking, thereby maintaining the dynamic equilibrium of the Golgi complex. The concepts emerging from this study should help to understand the control circuits that coordinate high-order cellular functions.     

Complementary inhibition of synoviocyte, smooth muscle cell or mouse lymphoma cell proliferation by a vanadyl curcumin complex compared to curcumin alone

A novel vanadyl curcumin complex (VO(cur)2) has been synthesized and and its physicochemical properties characterized. Biological characterization included in vitro testing for anti-rheumatic activity in synoviocytes, angiogenesis inhibition in smooth muscle cells and anti-cancer potential in mouse lymphoma cells; as well as in vivo testing for hypoglycemic activity by oral gavage in streptozotocin (STZ)-diabetic rats. VO(cur)2 was more effective as an anti-cancer agent, compared to uncomplexed curcumin or vanadyl ion alone, was more than twice as effective as curcumin alone as an anti-arthritic agent, and was more than four times as effective as curcumin alone in inhibiting smooth muscle cell proliferation. In both acute and chronic screening tests, VO(cur)2 was ineffective as an insulin mimetic agent; however, it also proved to be exceptionally non-toxic, with no evidence of negative symptomatology during a month-long treatment period, at doses up to and including 2.0 mmol kg(-1) day(-1).