Search for potential markers for prostate cancer diagnosis, prognosis and treatment in clinical tissue specimens using amine-specific isobaric tagging (iTRAQ) with two-dimensional liquid chromatography and tandem mass spectrometry

This study aimed to identify candidate new diagnosis and prognosis markers and medicinal targets of prostate cancer (PCa), using state of the art proteomics. A total of 20 prostate tissue specimens from 10 patients with benign prostatic hyperplasia (BPH) and 10 with PCa (Tumour Node Metastasis [TNM] stage T1-T3) were analyzed by isobaric stable isotope labeling (iTRAQ) and two-dimensional liquid chromatography-tandem mass spectrometry (2DLC-MS/MS) approaches using a hybrid quadrupole time-of-flight system (QqTOF). The study resulted in the reproducible identification of 825 nonredundant gene products (p < or = 0.05) of which 30 exhibited up-regulation (> or =2-fold) and another 35 exhibited down-regulation (< or =0.5-fold) between the BPH and PCa specimens constituting a major contribution toward their global proteomic assessment. Selected findings were confirmed by immunohistochemical analysis of prostate tissue specimens. The proteins determined support existing knowledge and uncover novel and promising PCa biomarkers. The PCa proteome found can serve as a useful aid for the identification of improved diagnostic and prognostic markers and ultimately novel chemopreventive and therapeutic targets.     

The cytoplasmic cyclophilin from <Emphasis Type="Italic">Azotobacter vinelandii</Emphasis> interacts with phosphate acetyltransferase isoforms enhancing their in vitro activity

Cyclophilins belong to the peptidyl-prolyl cis/trans isomerase family of enzymes (EC 5.2.1.8), which accelerate protein folding by catalysing the cis/trans isomerisation of proline imidic peptide bonds. In the present study, by a combination of bioinformatics methods, we identify phosphate acetyltransferase isoforms, AvPTA-1 and AvPTA-2, as potential interacting partners of AvPPIB, the cytoplasmic cyclophilin from Azotobacter vinelandii, and demonstrate their physical interaction by co-expression studies. A decrease in AvPPIB PPIase activity, in the presence of AvPTA-1 or AvPTA-2, further confirms each interaction. Phosphate acetyltransferases (EC 2.3.1.8) catalyse the reversible transfer of the acetyl group from acetyl-P to CoA, forming acetyl-CoA and inorganic phosphate. We examined the effect of AvPPIB on the enzymatic activity of both phosphate acetyltransferase isoforms, and noticed an enhancement of the activity, as well as an alteration of the K _m of each isoform, for the reaction substrates, indicating a possible function of AvPPIB in phosphate acetyltransferase activity modulation. Although PPIase activity seems not to be essential for these interactions, since AvPPIB_F99A active site mutant still interacts with both isoforms, it is responsible for the observed phosphate acetyltransferase activity enhancement as AvPPIB_F99A enhanced to a significantly lower extent the phosphate acetyltransferase activity of both isoforms compared with AvPPIB.     

Molecular-phylogenetic characterization of microbial communities imbalances in the small intestine of dogs with inflammatory bowel disease

An association between luminal commensal bacteria and inflammatory bowel disease (IBD) has been suggested in humans, but studies investigating the intestinal microbial communities of dogs with IBD have not been published. The aim of this study was to characterize differences of the small intestinal microbial communities between dogs with IBD and healthy control dogs. Duodenal brush cytology samples were endoscopically collected from 10 dogs with IBD and nine healthy control dogs. DNA was extracted and 16S rRNA gene was amplified using universal bacterial primers. Constructed 16S rRNA gene clone libraries were compared between groups. From a total of 1240 selected clones, 156 unique 16S rRNA gene sequences were identified, belonging to six phyla: Firmicutes (53.4%), Proteobacteria (28.4%), Bacteroidetes (7.0%), Spirochaetes (5.2%), Fusobacteria (3.4%), Actinobacteria (1.1%), and Incertae sedis (1.5%). Species richness was significantly lower in the IBD group (P=0.038). Principal component analysis indicated that the small intestinal microbial communities of IBD and control dogs are composed of distinct microbial communities. The most profound difference involved enrichment of the IBD dogs with members of the Enterobacteriaceae family. However, differences involving members of other families, such as Clostridiaceae, Bacteroidetes and Spirochaetes, were also identified. In conclusion, canine IBD is associated with altered duodenal microbial communities compared with healthy controls.     

A molecular switch that controls cell spreading and retraction

Integrin-dependent cell spreading and retraction are required for cell adhesion, migration, and proliferation, and thus are important in thrombosis, wound repair, immunity, and cancer development. It remains unknown how integrin outside-in signaling induces and controls these two opposite processes. This study reveals that calpain cleavage of integrin beta(3) at Tyr(759) switches the functional outcome of integrin signaling from cell spreading to retraction. Expression of a calpain cleavage-resistant beta(3) mutant in Chinese hamster ovary cells causes defective clot retraction and RhoA-mediated retraction signaling but enhances cell spreading. Conversely, a calpain-cleaved form of beta(3) fails to mediate cell spreading, but inhibition of the RhoA signaling pathway corrects this defect. Importantly, the calpain-cleaved beta(3) fails to bind c-Src, which is required for integrin-induced cell spreading, and this requirement of beta(3)-associated c-Src results from its inhibition of RhoA-dependent contractile signals. Thus, calpain cleavage of beta(3) at Tyr(759) relieves c-Src-mediated RhoA inhibition, activating the RhoA pathway that confines cell spreading and causes cell retraction.     

Unexpected inhibition of bradycardia pacing due to oversensing in ICD lead fracture associated with spurious tachyarrhythmia detection and discharges

Ιn a 76-year old man with a dual-chamber ICD implanted five years ago, dizzy spells and significant bradycardia on Holter were not initially recognized as inhibition of bradycardia pacing, due to oversensing. Hospital admission was deemed necessary only after repetitive ICD shocks attributed to right ventricular pace-sense lead fracture. The need to ensure adequate ICD antibradycardia backup pacing in pacing-dependent patients when deleterious sensing errors occur, cannot be overemphasized.     

Bacterial diversity of the outflows of a Polichnitos (Lesvos,Greece) hot spring,laboratory studies of a <Emphasis Type="Italic">Cyanobacterium</Emphasis> sp. strain and potential medical applications

The bacterial diversity of the outflows of Polichnitos (Lesvos, Greece) hot spring has been investigated. Cyanobacteria showing high sequence homologies with Phormidium sp. and Cyanobacterium aponinum were found. Members of the Alphaproteobacteria closely related to Rhodobium sp. Albidovulum sp., Rhodobacter sp., Microvigra sp., Nitratireductor sp. and Phaeobacter sp. Gammaproteobacteria, Betaproteobacteria and Firmicutes were represented by members of Idiomarina sp., Marinobacter sp., Shinella sp., Bacillus sp. and Clostridium sp. with sequence homologies ranging from 92% to 100%. Members of the Bacteroidetes and Planctomycetes were represented by sequences of novel phylogenetic linkages exhibiting 87–90% sequence homology with type strains. When the hot spring consortium was cultivated in bioreactor repeated batch culture under photo-autotrophic growth conditions at temperature < 30 °C, Cyanobacterium sp. dominated over Phormidium sp. Cyanobacterium sp. seems to have biotechnological potential since its extracellular broth exhibited a strong insecticidal activity against larvae of Aedes aegypti (a vector of important human diseases) and significant anti-cancer activity against the PC3 human prostate cancer cell line, while its toxicity against human endothelial cells was relatively low.     

Actin filament-organized local cortical endoplasmic reticulum aggregations in developing stomatal complexes of grasses

Endoplasmic reticulum (ER) immunolabeling in developing stomatal complexes and in the intervening cells of the stomatal rows (ICSRs) of Zea mays revealed that the cortical-ER forms distinct aggregations lining locally expanding wall regions. The polarized subsidiary cell mother cells (SMCs), displayed a cortical-ER-patch lining the wall region shared with the inducing guard cell mother cell (GMC), which disorganized during mitosis. In dividing SMCs, ER persisted in the preprophase band region and was unequally distributed in the mitotic spindle poles. The subsidiary cells (SCs) formed initially an ER-patch lining the common wall with the GMC or the young guard cells and afterwards an ER-ring in the junction of the SC wall with the neighboring ones. Distinct ER aggregations lined the ICSR wall regions shared with the SCs. The cortical-ER aggregations in stomatal cells of Z. mays were co-localized with actin filament (AF) arrays but both were absent from the respective cells of Triticum turgidum, which follow a different morphogenetic pattern. Experimental evidence showed that the interphase ER aggregations are organized by the respective AF arrays, while the mitotic ER aggregations by microtubules. These results revealed that AF and ER demarcated “cortical cytoplasmic domains” are activated below the locally expanding stomatal cell wall regions, probably via a mechanosensing mechanism triggered by the locally stressed plasmalemma/cell wall continuum. The probable role(s) of the local ER aggregations are discussed.