β -Thalassemia: Genotype-Phenotype Relationship

Editoria

Heritability of P. falciparum and P. vivax Malaria in a Karen Population in Thailand

The majority of studies concerning malaria host genetics have focused on individual genes that confer protection against rather than susceptibility to malaria. Establishing the relative impact of genetic versus non-genetic factors on malaria infection and disease is essential to focus effort on key determinant factors. This relative contribution has rarely been evaluated for Plasmodium falciparum and almost never for Plasmodium vivax. We conducted a longitudinal cohort study in a Karen population of 3,484 individuals in a region of mesoendemic malaria, Thailand from 1998 to 2005. The number of P. falciparum and P. vivax clinical cases and the parasite density per person were determined. Statistical analyses were performed to account for the influence of environmental factors and the genetic heritability of the phenotypes was calculated using the pedigree-based variance components model. The genetic contribution to the number of clinical episodes resulting from P. falciparum and P. vivax were 10% and 19% respectively. There was also moderate genetic contribution to the maximum and overall parasite trophozoite density phenotypes for both P. falciparum (16%&16%) and P. vivax (15%&13%). These values, for P. falciparum, were similar to those previously observed in a region of much higher transmission intensity in Senegal, West Africa. Although environmental factors play an important role in acquiring an infection, genetics plays a determinant role in the outcome of an infection with either malaria parasite species prior to the development of immunity

Hydrogen recycling during RF plasma heating in the U-3M torsatron

The hydrogen recycling behavior has been studied during the plasma experiments in torsatron U-3M. For this purpose, the time dependence of the molecular hydrogen pressure in the U-3M torsatron vacuum chamber in the modes of RF wall conditioning and RF plasma heating has been measured. The experimental results show that the hydrogen pumping from the vacuum chamber runs at constant rate during the RF discharge for each mode. After RF power switching-off the inverse desorption of hydrogen, accumulated during the RF discharge in the vacuum chamber walls and helical coil surfaces, is observed. When the antenna anode voltages and the RF pulse duration in both modes are increasing, the character of the time dependences of hydrogen pressure does not change significantly.Изучено поведение рециклинга водорода во время плазменных экспериментов на торсатроне У-3М. Для этой цели было проведено измерение временных зависимостей давления водорода в вакуумной камере торсатрона У-3М в режимах ВЧ-чистки стенок камеры и ВЧ-нагрева плазмы. Экспериментальные результаты показали, что в обоих режимах во время ВЧ-разряда скорость откачки водорода из вакуумной камеры остается постоянной для каждого из режимов. После выключения ВЧ-мощности наблюдается обратная десорбция водорода, накопленного во время ВЧ-разряда в стенках вакуумной камеры и винтовых катушек. Повышение анодных напряжений на ВЧ-антеннах и увеличение длительности ВЧ-импульса существенно не влияют на характер временных зависимостей давления водорода.Вивчено поведінку рециклінгу водню під час плазмових експериментів на торсатроні У-3М. Для цієї мети було проведено вимірювання часових залежностей тиску водню у вакуумній камері торсатрона У-3М в режимах ВЧ-чистки стінок камери і ВЧ-нагріву плазми. Експериментальні результати показали, що в обох режимах під час ВЧ-розряду швидкість відкачування водню з вакуумної камери залишається постійною для кожного з режимів. Після виключення ВЧ-потужності спостерігається зворотна десорбція водню, накопиченого під час ВЧ-розряду в стінках вакуумної камери і гвинтових котушок. Підвищення анодних напруг на ВЧ-антенах і збільшення тривалості ВЧ-імпульсу істотно не впливають на характер тимчасових залежностей тиску водню

Induction of fetal hemoglobin: Lentiviral shRNA knockdown of HBS1L in β0-thalassemia/HbE erythroid cells.

Imbalanced globin chain output contributes to thalassemia pathophysiology. Hence, induction of fetal hemoglobin in β-thalassemia and other β-hemoglobinopathies are of continuing interest for therapeutic approaches. Genome-wide association studies have identified three common genetic loci: namely β-globin (HBB), an intergenic region between MYB and HBS1L, and BCL11A underlying quantitative fetal hemoglobin production. Here, we report that knockdown of HBS1L (all known variants) using shRNA in early erythroblast obtained from β0-thalassemia/HbE patients triggers an upregulation of γ-globin mRNA 1.69 folds. There is modest perturbation of red cell differentiation assessed by flow cytometry and morphology studies. The levels of α- and β-globin mRNAs are relatively unaltered. Knockdown of HBS1L also increases the percentage of fetal hemoglobin around 16.7 folds when compared to non-targeting shRNA. Targeting HBS1L is attractive because of the potent induction of fetal hemoglobin and the modest effect on cell differentiation

Positively Selected G6PD-Mahidol Mutation Reduces Plasmodium vivax Density in Southeast Asians

International audienceGlucose-6-phosphate dehydrogenase (G6PD) deficiency—the most common known enzymopathy—is associated with neonatal jaundice and hemolytic anemia usually after exposure to certain infections, foods, or medications. Although G6PD-deficient alleles appear to confer a protective effect against malaria, the link with clinical protection from Plasmodium infection remains unclear. We investigated the effect of a common G6PD deficiency variant in Southeast Asia—the G6PD-Mahidol487A variant—on human survival related to vivax and falciparum malaria. Our results show that strong and recent positive selection has targeted the Mahidol variant over the past 1500 years. We found that the G6PD-Mahidol487A variant reduces vivax, but not falciparum, parasite density in humans, which indicates that Plasmodium vivax has been a driving force behind the strong selective advantage conferred by this mutation

Representative proteome map of differentially expressed proteins from the mitochondrial fractions of fibroblasts from (A) LHON cases (n = 7) and (U) unaffected LHON individuals (n = 3).

<p>Equal amounts of proteins (100 µg) from each sample were resolved by 2-DE. The numbers indicate the spot IDs of proteins whose expression levels differ significantly between the LHON cases and their unaffected relatives.</p

Functional categories and sub-cellular localizations of proteins identified in the study based on the MitoMiner Database and Nextprot.

<p>M = Mitochondria, MI = Mitochondrial intermembrane space, ER = Endoplasmic Reticulum, C = Cytoplasm, N = Nucleus, CSK = cytoskeleton.</p><p>Functional categories and sub-cellular localizations of proteins identified in the study based on the MitoMiner Database and Nextprot.</p

Characteristics of LHON cases and unaffected relatives recruited in the study.

<p>*MtDNA/nuclear DNA from fibroblast of each individual was measured according to Pejznochova M, 2008 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0106779#pone.0106779-Pejznochova1" target="_blank">[62]</a> by amplification of <i>ND5</i> gene in mitochondrial genome from position 13466–13650 (GenBank sequence NC_012920 gi:251831106), and <i>PARL</i> gene from nuclear genome from 16912–17165 (GenBank sequence: NC_000003.12 gi:224589815). Real-time PCR amplification was performed on Bio-Rad CFX 96 thermo cycler and the threshold cycle (Ct) was obtained. MtDNA/nuclear DNA ratio was calculated from the Ct (mtDNA)/Ct (nDNA) ratio. The increasing ratio shows decrease in amount of mtDNA per cell <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0106779#pone.0106779-Pejznochova1" target="_blank">[62]</a>.</p><p>Characteristics of LHON cases and unaffected relatives recruited in the study.</p

Differentially expressed proteins which show similar trends of down-regulation in the mitochondrial proteomes of both LHON cases and unaffected relatives when compared with controls.

<p>Differentially expressed proteins which show similar trends of down-regulation in the mitochondrial proteomes of both LHON cases and unaffected relatives when compared with controls.</p

Assessment of the purity of fibroblasts from a cultured skin biopsy.

<p>Fibroblast surface protein (FSP) was used as a marker in immunofluorescence of the cultured fibroblasts obtained directly obtained from the skin biopsy. The green represents fibroblasts and the nucleus was stained with Hoechst-dye 33342 which shows blue.</p