Geographical markers for <Emphasis Type="Italic">Saccharomyces cerevisiae</Emphasis> strains with similar technological origins domesticated for rice-based ethnic fermented beverages production in North East India

Autochthonous strains of Saccharomyces cerevisiae from traditional starters used for the production of rice-based ethnic fermented beverage in North East India were examined for their genetic polymorphism using mitochondrial DNA-RFLP and electrophoretic karyotyping. Mitochondrial DNA-RFLP analysis of S. cerevisiae strains with similar technological origins from hamei starter of Manipur and marcha starter of Sikkim revealed widely separated clusters based on their geographical origin. Electrophoretic karyotyping showed high polymorphism amongst the hamei strains within similar mitochondrial DNA-RFLP cluster and one unique karyotype of marcha strain was widely distributed in the Sikkim-Himalayan region. We conceptualized the possibility of separate domestication events for hamei strains in Manipur (located in the Indo-Burma biodiversity hotspot) and marcha strains in Sikkim (located in Himalayan biodiversity hotspot), as a consequence of less homogeneity in the genomic structure between these two groups, their clear separation being based on geographical origin, but not on technological origin and low strain level diversity within each group. The molecular markers developed based on HinfI-mtDNA-RFLP profile and the chromosomal doublets in chromosome VIII position of Sikkim-Himalayan strains could be effectively used as geographical markers for authenticating the above starter strains and differentiating them from other commercial strains.     

Common fragile sites in colon cancer cell lines: role of mismatch repair, RAD51 and poly(ADP-ribose) polymerase-1

Common fragile sites (CFS) are specific chromosomal areas prone to form gaps and breaks when cells are exposed to stresses that affect DNA synthesis, such as exposure to aphidicolin (APC), an inhibitor of DNA polymerases. The APC-induced DNA damage is repaired primarily by homologous recombination (HR), and RAD51, one of the key players in HR, participates to CFS stability. Since another DNA repair pathway, the mismatch repair (MMR), is known to control HR, we examined the influence of both the MMR and HR DNA repair pathways on the extent of chromosomal damage and distribution of CFS provoked by APC and/or by RAD51 silencing in MMR-deficient and -proficient colon cancer cell lines (i.e., HCT-15 and HCT-15 transfected with hMSH6, or HCT-116 and HCT-116/3+6, in which a part of a chromosome 3 containing the wild-type hMLH1 allele was inserted). Here, we show that MMR-deficient cells are more sensitive to APC-induced chromosomal damage particularly at the CFS as compared to MMR-proficient cells, indicating an involvement of MMR in the control of CFS stability. The most expressed CFS is FRA16D in 16q23, an area containing the tumour suppressor gene WWOX often mutated in colon cancer. We also show that silencing of RAD51 provokes a higher number of breaks in MMR-proficient cells with respect to their MMR-deficient counterparts, likely as a consequence of the combined inhibitory effects of RAD51 silencing on HR and MMR-mediated suppression of HR. The RAD51 silencing causes a broader distribution of breaks at CFS than that observed with APC. Treatment with APC of RAD51-silenced cells further increases DNA breaks in MMR-proficient cells. The RNAi-mediated silencing of PARP-1 does not cause chromosomal breaks or affect the expression/distribution of CFS induced by APC. Our results indicate that MMR modulates colon cancer sensitivity to chromosomal breaks and CFS induced by APC and RAD51 silencing.     

Early and transient release of leukocyte pentraxin 3 during acute myocardial infarction

Pentraxin 3 (PTX3) plays cardioprotective and anti-atherogenic roles in murine models. PTX3 blood levels raise during early acute myocardial infarction (AMI). Neutrophils from healthy subjects physiologically contain PTX3 in secondary (also called specific) granules. In this study, we report that circulating neutrophils release preformed PTX3 in the early phase of AMI (within 6 h from the onset of clinical symptoms). Depletion of intracellular PTX3 correlates with increased plasma levels and with platelet-neutrophil heterotypic aggregates. Neutrophil PTX3 returns to normal values 48 h after the onset of symptoms; concentration does not vary in matched healthy controls or in patients with chronic stable angina. In vitro, recognition of activated P-selectin(+) platelets causes the formation of neutrophil-platelet heteroaggregates and the release of neutrophil PTX3. Purified or membrane-bound P-selectin triggers PTX3 release from resting neutrophils. Released PTX3 binds to activated platelets in vitro. Moreover, PTX3 binds to a substantial fraction of platelets from patients in the circulating blood. PTX3-bound activated platelets have a reduced ability to 1) form heterotypic aggregates with neutrophils and monocytes; 2) activate neutrophils, as evaluated assessing the upregulation of leukocyte β(2) integrins; 3) aggregate with other platelets; and 4) bind to fibrinogen. Our results suggest that neutrophils early release prestored PTX3 in patients undergoing AMI. PTX3 binds to activated circulating platelets and dampens their proinflammatory and prothrombotic action, thus possibly contributing to its cardioprotective effects.     

Interplay between histopathological alterations, cigarette smoke and chemopreventive agents in defining microRNA profiles in mouse lung

We have investigated alterations of microRNA expression profiles in the apparently healthy lung of mice and rats as an early response to exposure to cigarette smoke, either mainstream (MCS) or environmental, and/or to treatment with chemopreventive agents. Further on, we evaluated microRNA alterations at a later stage, when lung tumors were detectable in MCS-exposed mice. Lung samples were available from previous studies, in which strain H mice had been exposed to MCS for 4 months, starting immediately after birth, and then kept in filtered air for an additional 3 months. Some samples were from MCS-exposed mice treated either with N-acetyl-l-cysteine during pregnancy or with phenethyl isothiocyanate after weaning. The analysis of 576 mouse microRNAs showed that MCS strongly dysregulated microRNA expression and that both chemopreventive agents efficiently attenuated this trend, especially in noncancer tissue. MicroRNA expression was affected by histopathology, with specific signatures related to occurrence of pneumonia, adenoma, or bronchoalveolar carcinoma. Within pairs of samples from individual mice, microRNA analysis discriminated adenomatous tissue and especially carcinomatous tissue from the surrounding normal appearing tissue. A series of microRNA alterations characterized the sequential stages of pulmonary carcinogenesis. The involved functions included oncogene activation, inhibition of oncosuppressor genes, recruitment of undifferentiated stem cells, inflammation, inhibition of gap-junctional intercellular communications, angiogenesis, invasiveness, and metastatization. Thus, microRNA expression profiles in lung are dysregulated by MCS along all steps of the carcinogenesis process and depend on the interplay among exposure to noxious agents, treatment with dietary and pharmacological agents, and occurrence of pulmonary diseases.     

Ghrelin in neuroendocrine tumors

Ghrelin is a 28 amino acid peptide, primarily produced by the oxyntic mucosa X/A like neuroendocrine cells in the stomach. It is also found in the small intestine, hypothalamus, pituitary gland, pancreas, heart, adipose tissue, and immune system. In gastrointestinal neuroendocrine tumors (NETs) ghrelin release has been well documented. Ghrelin is a brain-gut circuit peptide with an important role in the physiological regulation of appetite, response to hunger and starvation, metabolic and endocrine functions as energy expenditure, gastric motility and acid secretion, insulin secretion and glucose homeostasis, as well as in the potential connection to the central nervous system. Recently, there has been a significant interest in the biological effects of ghrelin in NETs. In this article, we present a comprehensive review of ghrelin's expression and a brief summary of ghrelin's physiological role in NETs patients with carcinoids, type A chronic atrophic gastritis (CAG), with or without MEN-1, and with and without liver metastases. We hope, with the research reviewed here, to offer compelling evidence of the potential significance of ghrelin in NETs, as well as to provide a useful guide to the future work in this area.     

High-mobility group box 1 (HMGB1) as a master regulator of innate immunity

Damage-associated molecular patterns (DAMPs) comprise intracellular molecules characterized by the ability to reach the extracellular environment, where they prompt inflammation and tissue repair. The high-mobility box group 1 (HMGB1) protein is a prototypic DAMP and is highly conserved in evolution. HMGB1 is released upon cell and tissue necrosis and is actively produced by immune cells. Evidence suggests that HMGB1 acts as a key molecule of innate immunity, downstream of persistent tissue injury, orchestrating inflammation, stem cell recruitment/activation, and eventual tissue remodeling.     

Asymmetric addition of dimethylzinc to alkylidenmalonates mediated by phosphorous ligands: a new synthetic route to floral fragrances

Six new phosphite ligands were prepared and their efficiency as chiral ligands was investigated in the copper-catalyzed asymmetric conjugate addition of dimethylzinc to diethyl 3-phenylpropylidenmalonate (5), affording the addition product with ees up to 74%. Moreover, a simple and straightforward route to floral fragrances Phenoxanol, Citralis, and Nitrile Citralis in optically active form through the above cited reaction was proposed.     

Medium pH and nitrate concentration effects on accumulation of triacylglycerol in two members of the chlorophyta

Algal-derived biodiesel is of particular interest because of several factors including: the potential for a near-carbon-neutral life cycle, the prospective ability for algae to capture carbon dioxide generated from coal, and algae’s high per acre yield potential. Our group and others have shown that in nitrogen limitation, and for a single species of Chlorella, a rise in culture medium pH yields triacylglycerol (TAG) accumulation. To solidify and expand on these triggers, the influence and interaction of pH and nitrogen concentration on lipid production was further investigated on Chlorophyceae Scenedesmus sp. and Coelastrella sp. Growth was monitored optically and TAG accumulation was monitored by Nile red fluorescence and confirmed by gas chromatography. Both organisms grew in all treatments and TAG accumulation was observed by two distinct conditions: high pH and nitrogen limitation. The Scenedesmus sp. was shown to grow and produce lipids to a larger degree in alkaliphilic conditions (pH >9) and was used to further investigate the interplay between TAG accumulation from high pH and/or nitrate depletion. Results given here indicate that TAG accumulation per cell, monitored by Nile red fluorescence, correlates with pH at the time of nitrate depletion.     

Cytogenetic stability of chicken T-cell line transformed with Marek's disease virus: atomic force microscope, a new tool for investigation

The Marek's disease virus (MDV) integration may induce a novel organization of chromatin architecture with a modified genetic expression. In our opinion it is worthwhile trying to relate cytogenetic stability to functional modifications. Recently, atomic force microscopy technique was applied to study the structure of chromosomes at a nanoscale level. This high resolution allows to investigate the different structure of chromatin in order to study cytogenetic stability and chromosome aberrations due to MDV insertion. In this paper data are presented indicating a duplication [78,WZ,dup(1p)(p22-p23)] and a deletion [78,WZ cht del(3)(q2.10)] of Chromosomes 1 and 3 relatively. Relationships between GTG (G-bands by Trypsin using Giemsa) bands and the topography of chromosomes are also discussed, naming them Topographic Banding. The architecture of chromosomes observed by AFM can be related to the data obtained with classic banding techniques thus overcoming the optical resolution limits. The presence of chromatin bridges between sister chromatids at most of the heterochromatic regions is also evidenced. Besides, we present different studies of the longitudinal and transversal symmetry of the hetero and euchromatic regions to clearly demonstrate a different underlying architecture of these regions. It is indeed evident that the heterochromatic bands are more symmetrical than euchromatic bands.