Adaptation and diversity along an altitudinal gradient in Ethiopian barley (<Emphasis Type="Italic">Hordeum vulgare</Emphasis> L.) landraces revealed by molecular analysis

Background  

Among the cereal crops, barley is the species with the greatest adaptability to a wide range of environments. To determine the level and structure of genetic diversity in barley (Hordeum vulgare L.) landraces from the central highlands of Ethiopia, we have examined the molecular variation at seven nuclear microsatellite loci.     

Doxorubicin-induced thymus senescence

Doxorubicin (DOX) is an anticancer drug used for the treatment of solid tumors. The ability of DOX to treat cancer is not specific to cancer cells; some of the cells that are normal may also become targets of DOX, thereby altering the normal cellular functions and eventual cell loss. DOX effects have been studied in detail in heart because of its ability to cause cardiomyopathy. The exact mechanism of DOX-induced cardiomyopathy is not completely understood. One of organs that can be affected by DOX is thymus. DOX treatment leads to degeneration of thymus; however, since thymus undergoes age-dependent degeneration, researchers have understudied the effect of DOX on thymus. In the present investigation, we studied the effects of DOX on thymus, an organ that is important for the T-cell maturation. DOX treatment led to loss of cortical cells, decrease lymphopoiesis and increased the number of Hassells corpuscles, a marker of thymus aging. Proteomics analysis led to identification of a number of thymic proteins whose expression are altered by in vivo DOX treatment. Taken together, these results are consistent with the notion that DOX-treatment leads to thymic senescence.     

EPO Receptor Gain-of-Function Causes Hereditary Polycythemia,Alters CD34+ Cell Differentiation and Increases Circulating Endothelial Precursors

Background

Gain-of-function of erythropoietin receptor (EPOR) mutations represent the major cause of primary hereditary polycythemia. EPOR is also found in non-erythroid tissues, although its physiological role is still undefined.

Methodology/Principal Findings

We describe a family with polycythemia due to a heterozygous mutation of the EPOR gene that causes a G→T change at nucleotide 1251 of exon 8. The novel EPOR G1251T mutation results in the replacement of a glutamate residue by a stop codon at amino acid 393. Differently from polycythemia vera, EPOR G1251T CD34⁺ cells proliferate and differentiate towards the erythroid phenotype in the presence of minimal amounts of EPO. Moreover, the affected individuals show a 20-fold increase of circulating endothelial precursors. The analysis of erythroid precursor membranes demonstrates a heretofore undescribed accumulation of the truncated EPOR, probably due to the absence of residues involved in the EPO-dependent receptor internalization and degradation. Mutated receptor expression in EPOR-negative cells results in EPOR and Stat5 phosphorylation. Moreover, patient erythroid precursors present an increased activation of EPOR and its effectors, including Stat5 and Erk1/2 pathway.

Conclusions/Significance

Our data provide an unanticipated mechanism for autosomal dominant inherited polycythemia due to a heterozygous EPOR mutation and suggest a regulatory role of EPO/EPOR pathway in human circulating endothelial precursors homeostasis.     

Comparative Proteomic Analysis of Serum from Patients with Systemic Sclerosis and Sclerodermatous GVHD. Evidence of Defective Function of Factor H

Background

Systemic sclerosis (SSc) is an autoimmune disease characterized by immunological and vascular abnormalities. Until now, the cause of SSc remains unclear. Sclerodermatous graft-versus-host disease (ScGVHD) is one of the most severe complications following bone marrow transplantation (BMT) for haematological disorders. Since the first cases, the similarity of ScGVHD to SSc has been reported. However, both diseases could have different etiopathogeneses. The objective of this study was to identify new serum biomarkers involved in SSc and ScGVHD.

Methodology

Serum was obtained from patients with SSc and ScGVHD, patients without ScGVHD who received BMT for haematological disorders and healthy controls. Bi-dimensional electrophoresis (2D) was carried out to generate maps of serum proteins from patients and controls. The 2D maps underwent image analysis and differently expressed proteins were identified. Immuno-blot analysis and ELISA assay were used to validate the proteomic data. Hemolytic assay with sheep erythrocytes was performed to evaluate the capacity of Factor H (FH) to control complement activation on the cellular surface. FH binding to endothelial cells (ECs) was also analysed in order to assess possible dysfunctions of this protein.

Principal Findings

Fourteen differentially expressed proteins were identified. We detected pneumococcal antibody cross-reacting with double stranded DNA in serum of all bone marrow transplanted patients with ScGVHD. We documented higher levels of FH in serum of SSc and ScGVHD patients compared healthy controls and increased sheep erythrocytes lysis after incubation with serum of diffuse SSc patients. In addition, we observed that FH binding to ECs was reduced when we used serum from these patients.

Conclusions

The comparative proteomic analysis of serum from SSc and ScGVHD patients highlighted proteins involved in either promoting or maintaining an inflammatory state. We also found a defective function of Factor H, possibly associated with ECs damage.     

Erythema infectiosum following generalized petechial eruption induced by human parvovirus B19

Parvovirus B19 is a DNA virus responsible for a wide spectrum of clinical illnesses. Among dermatological manifestations, the most common is erythema infectiosum, also known as the fifth disease. In 1990 Harms et al first described a papular-purpuric gloves and socks syndrome (PPGSS) due to parvovirus B19. It is an acute acral dermatosis characterized by an eruption of petechiae and small purpuric papules affecting the hands and feet in a gloves-and-socks distribution. Recently it was observed that PPGSS may be associated with involvement of the peri-oral region and the chin (acropetechial syndrome) and other sites provoking unusual presentation of the rash. We describe a patient with an acral purpura with the features of the "acropetechial syndrome" involving the buttocks, genital and axillary regions who subsequently developed a maculopapular eruption with the characteristics of the fifth disease. Parvovirus B19 DNA was detected by polymerase chain reaction (PCR) both in skin vasculitic lesions and in the serum during the petechial eruption, before the onset of antibodies. The immune response coincided with the development of the exanthem, suggesting a direct role of parvovirus B19 in the pathogenesis of endothelial cell injury.     

Lipolytic activity of Antarctic cold-adapted marine bacteria (Terra Nova Bay, Ross Sea)

AIMS: The aim of this study was to investigate the lipolytic activity of cold-adapted Antarctic marine bacteria and, furthermore, the combined effect of some environmental factors on this enzymatic process. METHODS AND RESULTS: Strains were assayed for lipolytic activity on a basal medium amended with seven individual fatty acid esters. A significant activity was observed for 148 isolates (95.5% of the total screened). The interactive effect of pH, temperature and NaCl concentration on the substrates was tested for six representative isolates, identified as Pseudoalteromonas, Psychrobacter and Vibrio. Differences between strains according to NaCl and pH tolerances were observed. Only one strain degraded the substrate more efficiently at 4 degrees C than at 15 degrees C. CONCLUSIONS: Our findings demonstrate that the lipolytic activity of Antarctic marine bacteria is rather variable, depending on culture conditions, and occurs in a wide range of salt concentration and pH. SIGNIFICANCE AND IMPACT OF THE STUDY: Isolation and characterization of bacteria that are able to efficiently remove lipids at low temperatures will provide insight into the possibility to use cold-adapted bacteria as a source of exploitable enzymes. Moreover, research on the interactive effects of salt concentration, pH and temperature will be useful to understand the true enzyme potentialities for industrial applications.