Plakoglobin localization to the cell border restores desmosome function in cells lacking 14-3-3γ

Desmosomes are cell-cell adhesion junctions that anchor intermediate filaments. Loss of 14-3-3γ in HCT116?cells led to defects in desmosome assembly due to a decrease in the transport of Plakoglobin (PG) to the cell border thus disrupting desmosome formation. Desmosome formation in cells lacking 14-3-3γ was restored by artificially localizing PG to the cell border by fusing it to EGFP-f (PG-EGFP-f). These results suggest that a major role of 14-3-3γ in desmosome assembly is to transport PG to the cell border leading to the initiation of desmosome formation.     

Amino acid residues distinct from the determinant region can profoundly affect activation of T cell clones by related antigens

Hen egg-white lysozyme (HEL)-specific T cell clones derived from the C57BL/6 strain were found to be about 100-fold more sensitive to the closely related ring-necked pheasant lysozyme (REL) in a dose-dependent proliferation assay. This apparent heteroclicity of REL was independent of the fine specificity of the clones. However, when stimulations by corresponding cyanogen bromide-cleaved peptides (L2H and L2R) known to contain the determinants recognized by all of the clones were compared, the preference for REL was lost. Conversely, an HEL-specific, I-Ad-restricted clone that did not respond to REL responded equally well to L2H and to L2R. Because the HEL/REL reactivity differences involved only the T cells and antigen-presenting cells (APC), and were correlated with differential sensitivity to the lysosomotropic drug chloroquine, it appears that the reactivity differences relate to the manner in which lysozymes are processed by the APC. Thus, conclusions about T cell "clonal specificity," usually attributed to differences in recognition of the determinant regions, may in some cases reflect differential antigen handling that depends on sites on the molecule distant from the determinant.     

Inhibition of Aerobic Glycolysis Attenuates Disease Progression in Polycystic Kidney Disease

Dysregulated signaling cascades alter energy metabolism and promote cell proliferation and cyst expansion in polycystic kidney disease (PKD). Here we tested whether metabolic reprogramming towards aerobic glycolysis (“Warburg effect”) plays a pathogenic role in male heterozygous Han:SPRD rats (Cy/+), a chronic progressive model of PKD. Using microarray analysis and qPCR, we found an upregulation of genes involved in glycolysis (Hk1, Hk2, Ldha) and a downregulation of genes involved in gluconeogenesis (G6pc, Lbp1) in cystic kidneys of Cy/+ rats compared with wild-type (+/+) rats. We then tested the effect of inhibiting glycolysis with 2-deoxyglucose (2DG) on renal functional loss and cyst progression in 5-week-old male Cy/+ rats. Treatment with 2DG (500 mg/kg/day) for 5 weeks resulted in significantly lower kidney weights (-27%) and 2-kidney/total-body-weight ratios (-20%) and decreased renal cyst index (-48%) compared with vehicle treatment. Cy/+ rats treated with 2DG also showed higher clearances of creatinine (1.98±0.67 vs 1.41±0.37 ml/min), BUN (0.69±0.26 vs 0.40±0.10 ml/min) and uric acid (0.38±0.20 vs 0.21±0.10 ml/min), and reduced albuminuria. Immunoblotting analysis of kidney tissues harvested from 2DG-treated Cy/+ rats showed increased phosphorylation of AMPK-α, a negative regulator of mTOR, and restoration of ERK signaling. Assessment of Ki-67 staining indicated that 2DG limits cyst progression through inhibition of epithelial cell proliferation. Taken together, our results show that targeting the glycolytic pathway may represent a promising therapeutic strategy to control cyst growth in PKD.     

Variability in Indian bread wheat (Triticum aestivum L.) varieties differing in nitrogen efficiency as assessed by microsatellite markers

Wheat (Triticum aestivum L.) is a staple food for half of the world. Its productivity and agronomical practices, especially for nitrogen supplementation, is governed by the nitrogen efficiency (NE) of the genotypes. We analyzed 16 popular cultivated Indian varieties of wheat for their NE and variability estimates using a set of 21 simple sequence repeat (SSR) markers, derived from each wheat chromosome. These genotypes were categorized into three groups, viz., low, moderate, and high nitrogen efficient. Of these 16 genotypes, we have reported six, eight, and two genotypes in high, moderate, and low NE categories, respectively. The differential NE in these genotypes was supported by nitrogen uptake and assimilation parameters. The values of average polymorphic information content and marker index for these SSR markers were estimated to be 0.32 and 0.59, respectively. The genetic similarity coefficient for all possible pairs of varieties ranged from 0.41 to 0.76, indicating the presence of considerable range of genetic diversity at molecular level. The dendrogram prepared on the basis of unweighted pair-group method of arithmetic average algorithm grouped the 16 wheat varieties into three major clusters. The clustering was strongly supported by high bootstrap values. The distribution of the varieties in different clusters and subclusters appeared to be related to their variability in NE parameter that was scored. Genetically diverse parents were identified that could potentially be used for their desirable characteristics in breeding programs for improvement of NE in wheat.     

Network Topologies Decoding Cervical Cancer

According to the GLOBOCAN statistics, cervical cancer is one of the leading causes of death among women worldwide. It is found to be gradually increasing in the younger population, specifically in the developing countries. We analyzed the protein-protein interaction networks of the uterine cervix cells for the normal and disease states. It was found that the disease network was less random than the normal one, providing an insight into the change in complexity of the underlying network in disease state. The study also portrayed that, the disease state has faster signal processing as the diameter of the underlying network was very close to its corresponding random control. This may be a reason for the normal cells to change into malignant state. Further, the analysis revealed VEGFA and IL-6 proteins as the distinctly high degree nodes in the disease network, which are known to manifest a major contribution in promoting cervical cancer. Our analysis, being time proficient and cost effective, provides a direction for developing novel drugs, therapeutic targets and biomarkers by identifying specific interaction patterns, that have structural importance.     

Rearranged beta T cell receptor genes in a helper T cell clone specific for lysozyme: no correlation between V beta and MHC restriction

The helper T cell clone 3H.25 is specific for hen egg white lysozyme and the class II MHC molecule I-Ab. This TH cell has three rearrangements in the beta-chain gene family-a V beta-D beta-J beta 1 and a D beta 2-J beta 2 rearrangement on one homolog and a D beta 1-J beta 2 rearrangement on the other. These observations demonstrate that this functional T lymphocyte expresses only a single V beta gene segment and, accordingly, exhibits allelic exclusion of beta-chain gene expression. The rearranged 3H.25 V beta gene segment is the same as that expressed in a T helper cell specific for cytochrome c and an I-Ek MHC molecule. Thus, there is no simple correlation between the V beta gene segment and antigen specificity or MHC restriction.     

Algal filtrate: a low cost substitute to synthetic growth regulators for direct organogenesis of embryo culture in <Emphasis Type="Italic">Jatropha curcas</Emphasis> (Ratanjyot)

Jatropha curcas, the energy plant has attained great attention in recent years because of its biodiesel production potential and medicinal value. This makes it imperative to search for techniques for its rapid propagation. Our research communication has shown for the first time direct organogenesis without callus formation from embryo culture of Jatropha. All previous reports embody callusing before further propagation and use of whole seeds. We also report the very economical protocol for J. curcas using cyanobacterial culture filtrate (Aulosira fertilissima) in place of chemical hormones giving this paper a cutting edge to in vitro propagation of J. curcas. The result showed that the number of days taken for shoots and root induction was quicker by adding the cyanobacterial filtrate and shoot and root length was comparatively higher than the other treatment with synthetic plant growth regulator. The same trend was found for chlorophyll a and b. No such report previously has ever focused on the use of cyanobacterial filtrate on in vitro germination of J. curcas embryo to regenerate plants at a faster rate. Ex vitro rooting is a new approach, which will reduce the time for regeneration still further, is an area that is being presently tried out.     

TimeView

TimeView is a MATLAB program that compares multiple temporal datasets from microarray experiments under two or more conditions, for example, temporal variation of cellular response upon exposure to different drugs. The current paucity of programs designed to efficiently compare and visualise gene expression profiles in such datasets led us to design TimeView, which also enhances data visualisation by plotting the expression profiles of a large number of genes on a single screen. AVAILABILITY: TimeView is available free of charge to all users at http://hugroup.cems.umn.edu/Research/Genomics/Timeview/timeview.htm. To use TimeView, users will require access to the commercial software MATLAB (version 6.5). A help document is available on the TimeView website.