General and species-specific transcriptional responses to downy mildew infection in a susceptible (Vitis vinifera) and a resistant (V. riparia) grapevine species

<p>Abstract</p> <p>Background</p> <p>Downy mildew is a destructive grapevine disease caused by <it>Plasmopara viticola </it>(Berk. and Curt.) Berl. and de Toni, which can only be controlled by intensive fungicide treatments. Natural sources of resistance from wild grapevine (<it>Vitis</it>) species are used in conventional breeding approaches, but the signals and effectors involved in resistance in this important crop species are not well understood.</p> <p>Results</p> <p>Early transcriptional changes associated with <it>P. viticola </it>infection in susceptible <it>V. vinifera </it>and resistant <it>V. riparia </it>plants were analyzed using the Combimatrix microarray platform. Transcript levels were measured 12 and 24 h post-inoculation, reflecting the time points immediately preceding the onset of resistance in <it>V. riparia</it>, as determined by microscopic analysis. Our data indicate that resistance in <it>V. riparia </it>is induced after infection, and is not based on differences in basal gene expression between the two species. The strong and rapid transcriptional reprogramming involves the induction of pathogenesis-related proteins and enzymes required for the synthesis of phenylpropanoid-derived compounds, many of which are also induced, albeit to a lesser extent, in <it>V. vinifera</it>. More interestingly, resistance in <it>V. riparia </it>also involves the specific modulation of numerous transcripts encoding components of signal transduction cascades, hypersensitive reaction markers and genes involved in jasmonate biosynthesis. The limited transcriptional modulation in <it>V. vinifera </it>represents a weak attempted defense response rather than the activation of compatibility-specific pathways.</p> <p>Conclusions</p> <p>Several candidate resistance genes were identified that could be exploited in future biotechnological approaches to increase disease resistance in susceptible grapevine species. Measurements of jasmonic acid and methyl jasmonate in infected leaves suggest that this hormone may also be involved in <it>V. riparia </it>resistance to <it>P. viticola</it>.</p

Decreased apoptotic priming and loss of BCL-2 dependence are functional hallmarks of Richter's syndrome

Richter's syndrome (RS) is the transformation of chronic lymphocytic leukemia (CLL) into a high-grade B-cell malignancy. Molecular and functional studies have pointed out that CLL cells are close to the apoptotic threshold and dependent on BCL-2 for survival. However, it remains undefined how evasion from apoptosis evolves during disease transformation. Here, we employed functional and static approaches to compare the regulation of mitochondrial apoptosis in CLL and RS. BH3 profiling of 17 CLL and 9 RS samples demonstrated that RS cells had reduced apoptotic priming and lower BCL-2 dependence than CLL cells. While a subset of RS was dependent on alternative anti-apoptotic proteins and was sensitive to specific BH3 mimetics, other RS cases harbored no specific anti-apoptotic addiction. Transcriptomics of paired CLL/RS samples revealed downregulation of pro-apoptotic sensitizers during disease transformation. Albeit expressed, effector and activator members were less likely to colocalize with mitochondria in RS compared to CLL. Electron microscopy highlighted reduced cristae width in RS mitochondria, a condition further promoting apoptosis resistance. Collectively, our data suggest that RS cells evolve multiple mechanisms that lower the apoptotic priming and shift the anti-apoptotic dependencies away from BCL-2, making direct targeting of mitochondrial apoptosis more challenging after disease transformation

A contribute to the comprehension of complexing agents and salt solutions reaction mechanism on chemical attack of type I molded glass containers

The commonly named ″glass delamination″ that is flakes or particles' appearance in injectables, is an important issue sometime at the origin of recalls from the market and of possible health issues to patients. In a previous work (1) the enhancement of glass surface chemical attack was shown in type I tubing and molded borosilicate glass containers, due to the presence of complexing agents in the aqueous solution in synergy with basic pH. In any case neither flakes development nor cloudy solutions were found also in the present work, to emphasize that flakes development (delamination) is not easily correlated even with a strong glass surface chemical attack. To understand the correlation between complexing agent chemical structure and the rate of glass chemical attack, a few homologue series of carboxylic and dicarboxylic acids were investigated. We considered the presence of functional groups (NH2, COOH, OH), alkyl chain length (3 to 6 carbon atoms) and the presence of double C=C bonds. Testing conditions were performed at 0.024M constant concentration, in the 5.8 - 10 pH range, in small-volume 23 mL type I molded glass containers, by autoclaving for 1 h at 121 °C according to the European Pharmacopoeia or United States Pharmacopoeia. The extracted silicon was analyzed by inductively coupled plasma atomic emission spectrometry. The collected data confirm that both dissociation constant pKa and molecular structure of the complexing agent are determinant enhancing factors of glass surface chemical attack. The second part of the work concerns with the glass surface chemical attack in the 5.8 - 9 pH range by alkali chloride solutions (NaCl and KCl 0.9% w/v and 0.0154M) widely used in parenteral therapies. For reason of completeness, this last research was extended also to LiCl and CsCl even if not used in injectables, to evaluate a possible influence of the molecular weight on the glass chemical attack. A correlation between alkali chlorides molecular weight and glass chemical attack as a function of pH was found. Therefore, in a preliminary way also acetic acid and EDTA (ethylenediaminetetraacetic acid) complexing power were examined in presence of Na or Li ions, showing some different chelating propensity as a function of the alkali ion. The present research can give precious information to the chemist involved in new pharmaceutical formulation or new molecules development, to prevent or consider some possible compatibility limitation with the packaging in type I borosilicate glass containers

Comparison of transcriptional changes associated to Plasmopara viticola infection in a resistant and a susceptible Vitis species.

Comparison of transcriptional changes associated to Plasmopara viticola infection in a resistant and a susceptible Vitis species