Osteoblastic differentiation of bone marrow mesenchymal stromal cells in Bruck Syndrome.

BACKGROUND: Osteogenesis Imperfecta (OI) (OMIM %259450) is a heterogeneous group of inherited disorders characterized by increased bone fragility, with clinical severity ranging from mild to lethal. The majority of OI cases are caused by mutations in COL1A1 or COL1A2. Bruck Syndrome (BS) is a further recessively-inherited OI-like phenotype in which bone fragility is associated with the unusual finding of pterygia and contractures of the large joints. Notably, several studies have failed to show any abnormalities in the biosynthesis of collagen 1 in BS patientes. Evidence was obtained for a specific defect of the procollagen telopeptide lysine hydroxylation in BS, whereas mutations in the gene PLOD2 have been identified. Recently, several studies described FKBP10 mutations in OI-like and BS patients, suggesting that FKBP10 is a bonafide BS locus. METHODS: We analyzed the coding region and intron/exon boundaries of COL1A1, COL1A2, PLOD2 and FKBP10 genes by sequence analysis using an ABI PRISM 3130 automated sequencer and Big Dye Terminator Sequencing protocol. Mononuclear cells obtained from the bone marrow of BS, OI patients and healthy donors were cultured and osteogenic differentiation was induced. The gene expression of osteoblast specific markers were also evaluated during the osteoblastic differentiation of mesenchymal stem cell (MSC) by qRT-PCR using an ABI7500 Sequence Detection System. RESULTS: No mutations in COL1A1, COL1A2 or PLOD2 were found in BS patient. We found a homozygous 1-base-pair duplication (c.831dupC) that is predicted to produce a translational frameshift mutation and a premature protein truncation 17 aminoacids downstream (p.Gly278ArgfsX95). The gene expression of osteoblast specific markers BGLAP, COL1A1, MSX2, SPARC and VDR was evaluated by Real Time RT-PCR during differentiation into osteoblasts and results showed similar patterns of osteoblast markers expression in BS and healthy controls. On the other hand, when compared with OI patients, the expression pattern of these genes was found to be different. CONCLUSIONS: Our work suggests that the gene expression profiles observed during mesenchymal stromal cell differentiation into osteoblast are distinct in BS patients as compared to OI patients. The present study shows for the first time that genes involved in osteogenesis are differentially expressed in BS and OI patients.

Biochemical responses in mussels Perna perna exposed to diesel B5.

In Brazil B5 blend (5% biodiesel and 95% diesel oil) has been adopted as mandatory fuel since 2010 for automotive vehicles. Since little is known about the effects of B5 exposure can promote on antioxidant system of marine biota this study aimed to assess if B5 can generate modifications in antioxidant parameters of mussels Perna perna. To address this question mussels were exposed to two concentrations of B5 (0.01 mL L(-1) and 0.1 mL L(-1)) for 6h, 12h, 48 h and 168 h. Then the activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST) and glutathione reductase (GR) were evaluated in gills and digestive gland as well as the contents of glutathione (GSH) and lipid peroxidation by measuring the malondialdehyde concentration (MDA). In the gills, GST activity decreased after 48 h and GR after 12h of exposure to B5. In digestive glands, the activities of SOD, GPx and GR were changed due to treatments. GSH concentration increased in digestive gland after 6h and 12h and in gills after 48 h for B5 0.1 mL L(-1) and after 168 h in the digestive gland for B5 0.01 mL L(-1) treatment. No lipid peroxidation was detected. The integrated biomarker response index (IBR) evidenced a B5 effect in the digestive gland after 168 h of exposure. Regarding the experimental conditions and species used in this study, long-term exposure to B5 is apparently more likely to affect the parameters tested in P. perna mussels.

Restricted dendritic cell and monocyte progenitors in human cord blood and bone marrow.

In mice, two restricted dendritic cell (DC) progenitors, macrophage/dendritic progenitors (MDPs) and common dendritic progenitors (CDPs), demonstrate increasing commitment to the DC lineage, as they sequentially lose granulocyte and monocyte potential, respectively. Identifying these progenitors has enabled us to understand the role of DCs and monocytes in immunity and tolerance in mice. In humans, however, restricted monocyte and DC progenitors remain unknown. Progress in studying human DC development has been hampered by lack of an in vitro culture system that recapitulates in vivo DC hematopoiesis. Here we report a culture system that supports development of CD34(+) hematopoietic stem cell progenitors into the three major human DC subsets, monocytes, granulocytes, and NK and B cells. Using this culture system, we defined the pathway for human DC development and revealed the sequential origin of human DCs from increasingly restricted progenitors: a human granulocyte-monocyte-DC progenitor (hGMDP) that develops into a human monocyte-dendritic progenitor (hMDP), which in turn develops into monocytes, and a human CDP (hCDP) that is restricted to produce the three major DC subsets. The phenotype of the DC progenitors partially overlaps with granulocyte-macrophage progenitors (GMPs). These progenitors reside in human cord blood and bone marrow but not in the blood or lymphoid tissues.

Biochemical responses in armored catfish (Pterygoplichthys anisitsi) after short-term exposure to diesel oil, pure biodiesel and biodiesel blends.

Biodiesel fuel is gradually replacing petroleum-based diesel oil use. Despite the biodiesel being considered friendlier to the environment, little is known about its effects in aquatic organisms. In this work we evaluated whether biodiesel exposure can affect oxidative stress parameters and biotransformation enzymes in armored catfish (Pterygoplichthys anisitsi, Loricariidae), a South American endemic species. Thus, fish were exposed for 2 and 7d to 0.01mLL(-1) and 0.1mLL(-1) of pure diesel, pure biodiesel (B100) and blends of diesel with 5% (B5) and 20% (B20) biodiesel. Lipid peroxidation (malondialdehyde) levels and the activities of the enzymes glutathione S-transferase, superoxide dismutase, catalase and glutathione peroxidase were measured in liver and gills. Also, DNA damage (8-oxo-7, 8-dihydro-2'-deoxyguanosine) levels in gills and 7-ethoxyresorufin-O-deethylase activity in liver were assessed. Pure diesel, B5 and B20 blends changed most of the enzymes tested and in some cases, B5 and B20 induced a higher enzyme activity than pure diesel. Antioxidant system activation in P. anisitsi was effective to counteract reactive oxygen species effects, since DNA damage and lipid peroxidation levels were maintained at basal levels after all treatments. However, fish gills exposed to B20 and B100 presented increased lipid peroxidation. Despite biodiesel being more biodegradable fuel that emits less greenhouse gases, the increased lipid peroxidation showed that biofuel and its blends also represent hazards to aquatic biota.

Molecular evolution of a malaria resistance gene (DARC) in primates.

Genes involved in host-pathogen interactions are often strongly affected by positive natural selection. The Duffy antigen, coded by the Duffy antigen receptor for chemokines (DARC) gene, serves as a receptor for Plasmodium vivax in humans and for Plasmodium knowlesi in some nonhuman primates. In the majority of sub-Saharan Africans, a nucleic acid variant in GATA-1 of the gene promoter is responsible for the nonexpression of the Duffy antigen on red blood cells and consequently resistance to invasion by P. vivax. The Duffy antigen also acts as a receptor for chemokines and is expressed in red blood cells and many other tissues of the body. Because of this dual role, we sequenced a ~3,000-bp region encompassing the entire DARC gene as well as part of its 5' and 3' flanking regions in a phylogenetic sample of primates and used statistical methods to evaluate the nature of selection pressures acting on the gene during its evolution. We analyzed both coding and regulatory regions of the DARC gene. The regulatory analysis showed accelerated rates of substitution at several sites near known motifs. Our tests of positive selection in the coding region using maximum likelihood by branch sites and maximum likelihood by codon sites did not yield statistically significant evidence for the action of positive selection. However, the maximum likelihood test in which the gene was subdivided into different structural regions showed that the known binding region for P. vivax/P. knowlesi is under very different selective pressures than the remainder of the gene. In fact, most of the gene appears to be under strong purifying selection, but this is not evident in the binding region. We suggest that the binding region is under the influence of two opposing selective pressures, positive selection possibly exerted by the parasite and purifying selection exerted by chemokines.