Intra-Golgi transport: a way to a new paradigm?

The morpho-functional principles of intra-Golgi transport are, surprisingly, still not clear, which is in marked contrast to our advanced knowledge of the underlying molecular machineries. Recently, the conceptual and technological hindrances that had delayed progress in this area have been disappearing, and a cluster of powerful morphological techniques has been revealing new glimpses of the organization of traffic in intact cells. Here, we discuss the new concepts around the present models of intra-Golgi transport.     

T-cell-dependent hybrid resistance against a natural killer-resistant Moloney virus-induced lymphoma (YWA): in vitro generation of cytotoxic lymphocytes

A Moloney leukemia virus-induced lymphoma of the A.SW strain, YWA, was used to generate cytotoxic cells in vitro. Cocultivation of spleen cells from in vivo primed syngeneic and semisyngeneic mice with X-irradiated YWA tumor cells for 5 days resulted in a strong killing activity against YWA. The cytotoxicity was H-2 restricted and mediated by Thy-1.2-positive lymphocytes. F1 hybrids with variable degrees of natural resistance to the YWA tumor in vivo all generated cytotoxic cells after secondary stimulation in vitro but showed differences in optimal responder:stimulator requirements.     

2‐phenylethynesulphonamide (PFT‐μ) enhances the anticancer effect of the novel hsp90 inhibitor NVP‐AUY922 in melanoma,by reducing GSH levels

Heat shock proteins (HSPs), are molecular chaperones that assist the proper folding of nascent proteins. This study aims to evaluate the antitumour effects of the hsp90 inhibitor NVP‐AUY922 in melanoma, both in vitro and in vivo. Our results show that NVP‐AUY922 inhibits melanoma cell growth in vitro, with down regulation of multiple signalling pathways involved in melanoma progression such as NF‐?B and MAPK/ERK. However, NVP‐AUY922 was unable to limit tumour growth in vivo. Cotreatment of A375M xenografts with NVP‐AUY922 and PFT‐μ, a dual inhibitor of both hsp70 and autophagy, induced a synergistic increase of cell death in vitro, and delayed tumour formation in A375M xenografts. PFT‐μ depleted cells from the reduced form of glutathione (GSH) and increased oxidative stress. The oxidative stress induced by PFT‐μ further enhanced NVP‐AUY922‐induced cytotoxic effects. These data suggest a potential therapeutic role for NVP‐AUY922 used in combination with PFT‐μ, in melanoma.     

Leishmaniasis and poverty

Leishmaniasis, a neglected tropical disease, has strong but complex links with poverty. The burden of leishmaniasis falls disproportionately on the poorest segments of the global population. Within endemic areas, increased infection risk is mediated through poor housing conditions and environmental sanitation, lack of personal protective measures and economically driven migration and employment that bring nonimmune hosts into contact with infected sand flies. Poverty is associated with poor nutrition and other infectious diseases, which increase the risk that a person (once infected) will progress to the clinically manifested disease. Lack of healthcare access causes delays in appropriate diagnosis and treatment and accentuates leishmaniasis morbidity and mortality, particularly in women. Leishmaniasis diagnosis and treatment are expensive and families must sell assets and take loans to pay for care, leading to further impoverishment and reinforcement of the vicious cycle of disease and poverty. Public investment in treatment and control would decrease the leishmaniasis disease burden and help to alleviate poverty.     

Differential Response of Lymphocytes and Neutrophils to High Intensity Physical Activity and to Vitamin C Diet Supplementation

We have determined the effects of chronic vitamin C intake on neutrophil and lymphocyte antioxidant defences during the acute phase immune response induced by intense exercise. Blood samples were taken from 16 voluntary athletes in basal conditions, both immediately after and 1 h after a duathlon competition. Sportsmen's nutrient intakes were determined before the competition. After determining the basal plasmatic ascorbate levels, the results were analysed taking into account the vitamin C intake and their plasmatic levels. Two groups were constituted, the vitamin C supplemented group and the control group, with the dietary vitamin C intake as the only statistical difference between groups. The duathlon competition induced a significant neutrophilia, which was higher in the supplemented group. Lymphocyte antioxidant enzyme activities increased after the competition, with a higher increase in SOD activity in the control group than in the supplemented one. The competition decreased neutrophil antioxidant enzyme activities and neutrophil ascorbate concentration. The decrease in the SOD activity in the supplemented group was higher than in the control group. Finally, the duathlon competition increased the expression of MAC-1 neutrophil adhesion molecule in the supplemented group. High vitamin C intake influenced the response of neutrophils and lymphocytes to oxidative stress induced by exercise, increasing the neutrophil activation.     

Global and grain-specific accumulation of glycoside hydrolase family 10 xylanases in transgenic maize (Zea mays)

In planta expression of cell wall degrading enzymes is a promising approach for developing optimized biomass feedstocks that enable low-cost cellulosic biofuels production. Transgenic plants could serve as either an enzyme source for the hydrolysis of pretreated biomass or as the primary biomass feedstock in an autohydrolysis process. In this study, two xylanase genes, Bacillus sp. NG-27 bsx and Clostridium stercorarium xynB, were expressed in maize (Zea mays) under the control of two different promoters. Severe phenotypic effects were associated with xylanase accumulation in maize, including stunted plants and sterile grains. Global expression of these xylanases from the rice ubiquitin 3 promoter (rubi3) resulted in enzyme accumulation of approximately 0.01 mg enzyme per gram dry weight, or approximately 0.1% of total soluble protein (TSP). Grain-specific expression of these enzymes from the rice glutelin 4 promoter (GluB-4) resulted in higher-level accumulation of active enzyme, with BSX and XynB accumulating up to 4.0% TSP and 16.4% TSP, respectively, in shriveled grains from selected T0 plants. These results demonstrate the potential utility of the GluB-4 promoter for biotechnological applications. The phenotypic effects of xylanase expression in maize presented here demonstrate the difficulties of hemicellulase expression in an important crop for cellulosic biofuels production. Potential alternate approaches to achieve xylanase accumulation in planta without the accompanying negative phenotypes are discussed.     

Clinical Audit of COPD Patients Requiring Hospital Admissions in Spain: AUDIPOC Study

BACKGROUNDS: AUDIPOC is a nationwide clinical audit that describes the characteristics, interventions and outcomes of patients admitted to Spanish hospitals because of an exacerbation of chronic obstructive pulmonary disease (ECOPD), assessing the compliance of these parameters with current international guidelines. The present study describes hospital resources, hospital factors related to case recruitment variability, patients' characteristics, and adherence to guidelines. METHODOLOGY/PRINCIPAL FINDINGS: An organisational database was completed by all participant hospitals recording resources and organisation. Over an 8-week period 11,564 consecutive ECOPD admissions to 129 Spanish hospitals covering 70% of the Spanish population were prospectively identified. At hospital discharge, 5,178 patients (45% of eligible) were finally included, and thus constituted the audited population. Audited patients were reassessed 90 days after admission for survival and readmission rates. A wide variability was observed in relation to most variables, hospital adherence to guidelines, and readmissions and death. Median inpatient mortality was 5% (across-hospital range 0-35%). Among discharged patients, 37% required readmission (0-62%) and 6.5% died (0-35%). The overall mortality rate was 11.6% (0-50%). Hospital size and complexity and aspects related to hospital COPD awareness were significantly associated with case recruitment. Clinical management most often complied with diagnosis and treatment recommendations but rarely (<50%) addressed guidance on healthy life-styles. CONCLUSIONS/SIGNIFICANCE: The AUDIPOC study highlights the large across-hospital variability in resources and organization of hospitals, patient characteristics, process of care, and outcomes. The study also identifies resources and organizational characteristics associated with the admission of COPD cases, as well as aspects of daily clinical care amenable to improvement.     

Strigolactones suppress adventitious rooting in Arabidopsis and pea

Adventitious root formation is essential for the propagation of many commercially important plant species and involves the formation of roots from nonroot tissues such as stems or leaves. Here, we demonstrate that the plant hormone strigolactone suppresses adventitious root formation in Arabidopsis (Arabidopsis thaliana) and pea (Pisum sativum). Strigolactone-deficient and response mutants of both species have enhanced adventitious rooting. CYCLIN B1 expression, an early marker for the initiation of adventitious root primordia in Arabidopsis, is enhanced in more axillary growth2 (max2), a strigolactone response mutant, suggesting that strigolactones restrain the number of adventitious roots by inhibiting the very first formative divisions of the founder cells. Strigolactones and cytokinins appear to act independently to suppress adventitious rooting, as cytokinin mutants are strigolactone responsive and strigolactone mutants are cytokinin responsive. In contrast, the interaction between the strigolactone and auxin signaling pathways in regulating adventitious rooting appears to be more complex. Strigolactone can at least partially revert the stimulatory effect of auxin on adventitious rooting, and auxin can further increase the number of adventitious roots in max mutants. We present a model depicting the interaction of strigolactones, cytokinins, and auxin in regulating adventitious root formation.     

An investigation of the resolution of inflammation (catabasis) in COPD

Background

Chronic Obstructive Pulmonary Disease (COPD) is characterized by an enhanced inflammatory response to smoking that persists despite quitting. The resolution of inflammation (catabasis) is a complex and highly regulated process where tissue resident macrophages play a key role since they phagocytose apoptotic cells (efferocytosis), preventing their secondary necrosis and the spill-over of their pro-inflammatory cytoplasmic content, and release pro-resolution and tissue repair molecules, such as TGFβ, VEGF and HGF. Because inflammation does not resolve in COPD, we hypothesized that catabasis may be abnormal in these patients.

Methods

To explore this hypothesis, we studied lung tissue samples obtained at surgery from 21 COPD patients, 22 smokers with normal spirometry and 13 non-smokers controls. In these samples we used: (1) immunohistochemistry to assess the expression of CD44, CD36, VEGF and TGFβ in lung macrophages; (2) real time PCR to determine HGF, PPARγ, TGFβ, VEGF and MMP-9 gene expression; and, (3) ELISA to quantify lipoxin A4, a lipid mediator of catabasis.

Results

We found that current and former smokers with COPD showed: (1) more inflammation (higher MMP-9 expression); (2) reduced macrophage surface expression of CD44, a key efferocytosis receptor; and, (3) similar levels of TGFβ, VEGF, HGF, PPARγ, and lipoxin A4 than smokers with normal spirometry, despite the presence of inflammation and disease.

Conclusions

These results identify several potential abnormalities of catabasis in patients with COPD.     

Coat Gene Profiles of Several Cat Populations in Cuba,Costa Rica,Colombia, Paraguay,Chile and Argentina,and Possible Genetic Origins of These Cat Populations

Until the present moment, only a scarce number of Latin American domestic cat populations have been studied from a population genetic standpoint. For this reason, the cat populations of La Havana (Cuba), San José (Costa Rica), Bogotá and Ibagué (Colombia), Asunción (Paraguay), Santiago (Chile) and Buenos Aires (Argentina) were sampled for several coat genes. The results obtained were as follows: (1) there was a strong genetic resemblence between several Hispanic American cat populations (especially, those of Buenos Aires, San José and the two Colombian populations studied) and those from South Western United States (California, Texas and Colorado), which adds suport to the suspicion that these populations probably have a common origin; (2) The cat population of Santiago (Chile), contrarily to the other Hispanic American populations studied, showed a strong genetic resemblance with some Anglo North American populations; and (3) The I (long hair) and d(dilution) alleles showed systematic higher frequencies in the Hispanic American populations than those observed in Spain. Although the Hispanic American populations were not identical to the current Spanish populations (with the exception of Asuncion), this historic genetic experiment was very different to that found for the British populations and their overseas colonies.