Differential regulation of imprinting in the murine embryo and placenta by the Dlk1-Dio3 imprinting control region

Genomic imprinting is an epigenetic mechanism controlling parental-origin-specific gene expression. Perturbing the parental origin of the distal portion of mouse chromosome 12 causes alterations in the dosage of imprinted genes resulting in embryonic lethality and developmental abnormalities of both embryo and placenta. A 1 Mb imprinted domain identified on distal chromosome 12 contains three paternally expressed protein-coding genes and multiple non-coding RNA genes, including snoRNAs and microRNAs, expressed from the maternally inherited chromosome. An intergenic, parental-origin-specific differentially methylated region, the IG-DMR, which is unmethylated on the maternally inherited chromosome, is necessary for the repression of the paternally expressed protein-coding genes and for activation of the maternally expressed non-coding RNAs: its absence causes the maternal chromosome to behave like the paternally inherited one. Here, we characterise the developmental consequences of this epigenotype switch and compare these with phenotypes associated with paternal uniparental disomy of mouse chromosome 12. The results show that the embryonic defects described for uniparental disomy embryos can be attributed to this one cluster of imprinted genes on distal chromosome 12 and that these defects alone, and not the mutant placenta, can cause prenatal lethality. In the placenta, the absence of the IG-DMR has no phenotypic consequence. Loss of repression of the protein-coding genes occurs but the non-coding RNAs are not repressed on the maternally inherited chromosome. This indicates that the mechanism of action of the IG-DMR is different in the embryo and the placenta and suggests that the epigenetic control of imprinting differs in these two lineages.     

Correlation analysis reveals the emergence of coherence in the gene expression dynamics following system perturbation

Time course gene expression experiments are a popular means to infer co-expression. Many methods have been proposed to cluster genes or to build networks based on similarity measures of their expression dynamics. In this paper we apply a correlation based approach to network reconstruction to three datasets of time series gene expression following system perturbation: 1) Conditional, Tamoxifen dependent, activation of the cMyc proto-oncogene in rat fibroblast; 2) Genomic response to nutrition changes in D. melanogaster; 3) Patterns of gene activity as a consequence of ageing occurring over a life-span time series (25y-90y) sampled from T-cells of human donors. We show that the three datasets undergo similar transitions from an "uncorrelated" regime to a positively or negatively correlated one that is symptomatic of a shift from a "ground" or "basal" state to a "polarized" state. In addition, we show that a similar transition is conserved at the pathway level, and that this information can be used for the construction of "meta-networks" where it is possible to assess new relations among functionally distant sets of molecular functions.     

Antibody-mediated delivery of IL-10 inhibits the progression of established collagen-induced arthritis

The antibody-mediated targeted delivery of cytokines to sites of disease is a promising avenue for cancer therapy, but it is largely unexplored for the treatment of chronic inflammatory conditions. Using both radioactive and fluorescent techniques, the human monoclonal antibodies L19 and G11 (specific to two markers of angiogenesis that are virtually undetectable in normal adult tissues) were found to selectively localize at arthritic sites in the murine collagen-induced model of rheumatoid arthritis following intravenous (i.v.) administration. The same animal model was used to study the therapeutic action of the L19 antibody fused to the cytokines IL-2, tumour necrosis factor (TNF) and IL-10. Whereas L19–IL-2 and L19–TNF treatment led to increased arthritic scores and paw swellings, the fusion protein L19–IL-10 displayed a therapeutic activity, which was superior to the activity of IL-10 fused to an antibody of irrelevant specificity in the mouse. The anti-inflammatory cytokine IL-10 has been investigated for the treatment of patients with rheumatoid arthritis, but clinical development plans have been discontinued because of a lack of efficacy. Because the antigen recognised by L19 is strongly expressed at sites of arthritis in humans and identical in both mice and humans, it suggests that the fusion protein L19–IL-10 might help overcome some of the clinical limitations of IL-10 and provide a therapeutic benefit to patients with chronic inflammatory disorders, including arthritis.     

Effect of different growth factors on human osteoblasts activities: a possible application in bone regeneration for tissue engineering

Cultured human primary osteoblasts reproduce the phenotypic differentiation and maturation of cells in vivo. We have investigated the influence of three isoforms of transforming growth factor beta (TGF-beta1, TGF-beta2 and TGF-beta3), three fibroblast growth factors (FGF-2, FGF-4 and FGF-6) and the active metabolite of Vitamin D [1,25-(OH)(2)D3] on proliferation, alkaline phosphatase activity and mineralization of human osteoblasts during a period of 24 days of culture. TGF-beta isoforms and three FGFs examined have been proved to be inducers of osteoblasts proliferation (higher extent for TGF-beta and FGF-2) and inhibitors of alkaline phosphatase activity and osteoblasts mineralization. Combination of these growth factors with the active form of Vitamin D induced osteodifferentiation. In fact Vitamin D showed an additive effect on alkaline phosphatase activity and calcium content, induced by FGF-2 and TGF-beta in human osteoblast. These results highlight the potential of proliferating cytokines' combination with mineralizing agents for in vitro bone growth induction in bone tissue engineering.     

Generation of human scFvs antibodies recognizing a prion protein epitope expressed on the surface of human lymphoblastoid cells

Background  

A hallmark of prion disease is the transformation of normal cellular prion protein (PrPc) into an infectious disease-associated isoform, (PrPsc). Anti-prion protein monoclonal antibodies are invaluable for structure-function studies of PrP molecules. Furthermore recent in vitro and in vivo studies indicate that anti-PrP monoclonal antibodies can prevent the incorporation of PrPc into propagating prions.     

Effects of human-induced water level fluctuations on copepod assemblages of the littoral zone of Lake Maggiore

Hydrobiologia - Human-induced water level fluctuations (WLFs) are among the major pressures threatening lake ecosystems. Their effect on meiobenthic species of the littoral zone has been...     

TRP channel–associated factors are a novel protein family that regulates TRPM8 trafficking and activity

TRPM8 is a cold sensor that is highly expressed in the prostate as well as in other non-temperature-sensing organs, and is regulated by downstream receptor–activated signaling pathways. However, little is known about the intracellular proteins necessary for channel function. Here, we identify two previously unknown proteins, which we have named “TRP channel–associated factors” (TCAFs), as new TRPM8 partner proteins, and we demonstrate that they are necessary for channel function. TCAF1 and TCAF2 both bind to the TRPM8 channel and promote its trafficking to the cell surface. However, they exert opposing effects on TRPM8 gating properties. Functional interaction of TCAF1/TRPM8 also leads to a reduction in both the speed and directionality of migration of prostate cancer cells, which is consistent with an observed loss of expression of TCAF1 in metastatic human specimens, whereas TCAF2 promotes migration. The identification of TCAFs introduces a novel mechanism for modulation of TRPM8 channel activity.     

Steneosaurus edwardsi (Thalattosuchia: Teleosauridae), the largest known crocodylomorph of the Middle Jurassic

Teleosaurids were a clade of marine crocodylomorphs that were globally distributed during the Jurassic Period. They evolved a wide range of body sizes, from small (～2–3 m) to very large (> 9 m). Until now, the largest known Middle Jurassic teleosaurid was ‘Steneosaurus’ obtusidens, from the Oxford Clay Formation of the UK. Here, we re‐examine a very large Oxford Clay specimen (ilium, ischium, and femur) that had been tentatively attributed to ‘S.’ obtusidens. Based on comparative anatomical study with the ‘S.’ obtusidens holotype and referred specimens of Steneosaurus edwardsi and Steneosaurus leedsi, we conclude that this very large individual actually pertains to S. edwardsi. Based on comparisons with the Machimosaurus mosae neotype (which has a complete femur and skeleton), we estimate a total length in excess of 7 m for this large S. edwardsi individual, making it the largest known Middle Jurassic teleosaurid. Therefore, along with the closely related genus Machimosaurus, this clade of large‐bodied Middle–Late Jurassic teleosaurids were the largest species during the first 100 million years of crocodylomorph evolution. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, ●● , ●●–●●.     

Engineering temporal accumulation of a low recalcitrance polysaccharide leads to increased C6 sugar content in plant cell walls

Reduced cell wall recalcitrance and increased C6 monosaccharide content are desirable traits for future biofuel crops, as long as these biomass modifications do not significantly alter normal growth and development. Mixed‐linkage glucan (MLG), a cell wall polysaccharide only present in grasses and related species among flowering plants, is comprised of glucose monomers linked by both β‐1,3 and β‐1,4 bonds. Previous data have shown that constitutive production of MLG in barley (Hordeum vulgare) severely compromises growth and development. Here, we used spatio‐temporal strategies to engineer Arabidopsis thaliana plants to accumulate significant amounts of MLG in the cell wall by expressing the rice CslF6 MLG synthase using secondary cell wall and senescence‐associated promoters. Results using secondary wall promoters were suboptimal. When the rice MLG synthase was expressed under the control of a senescence‐associated promoter, we obtained up to four times more glucose in the matrix cell wall fraction and up to a 42% increase in saccharification compared to control lines. Importantly, these plants grew and developed normally. The induction of MLG deposition at senescence correlated with an increase of gluconic acid in cell wall extracts of transgenic plants in contrast to the other approaches presented in this study. MLG produced in Arabidopsis has an altered structure compared to the grass glucan, which likely affects its solubility, while its molecular size is unaffected. The induction of cell wall polysaccharide biosynthesis in senescing tissues offers a novel engineering alternative to enhance cell wall properties of lignocellulosic biofuel crops.