26 research outputs found
Controlling cell behavior through the design of polymer surfaces
Polymers have gained a remarkable place in the biomedical
fi eld as materials for the fabrication of various devices and
for tissue engineering applications. The initial acceptance or
rejection of an implantable device is dictated by the crosstalk
of the material surface with the bioentities present in the
physiological environment. Advances in microfabrication
and nanotechnology offer new tools to investigate the
complex signaling cascade induced by the components of
the extracellular matrix and consequently allow cellular
responses to be tailored through the mimicking of some
elements of the signaling paths. Patterning methods and
selective chemical modifi cation schemes at different length
scales can provide biocompatible surfaces that control
cellular interactions on the micrometer and sub-micrometer
scales on which cells are organized. In this review, the
potential of chemically and topographically structured
micro- and nanopolymer surfaces are discussed in hopes
of a better understanding of cell–biomaterial interactions,
including the recent use of biomimetic approaches or
stimuli-responsive macromolecules. Additionally, the focus
will be on how the knowledge obtained using these surfaces
can be incorporated to design biocompatible materials for
various biomedical applications, such as tissue engineering,
implants, cell-based biosensors, diagnostic systems, and basic
cell biology. The review focusses on the research carried out
during the last decade.The research leading to these results has received partial funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no. NMP4-SL-2009-229292 and by the FCT projects PTDC/FIS/68517/2006, PTDC/QUI/69263/2006, PTDC/FIS/68209/2006, and PTDC/QUI/68804/2006
Activating Signal Cointegrator 2 Belongs to a Novel Steady-State Complex That Contains a Subset of Trithorax Group Proteins
Many transcription coactivators interact with nuclear receptors in a ligand- and C-terminal transactivation function (AF2)-dependent manner. These include activating signal cointegrator 2 (ASC-2), a recently isolated transcriptional coactivator molecule, which is amplified in human cancers and stimulates transactivation by nuclear receptors and numerous other transcription factors. In this report, we show that ASC-2 belongs to a steady-state complex of approximately 2 MDa (ASC-2 complex [ASCOM]) in HeLa nuclei. ASCOM contains retinoblastoma-binding protein RBQ-3, α/β-tubulins, and trithorax group proteins ALR-1, ALR-2, HALR, and ASH2. In particular, ALR-1/2 and HALR contain a highly conserved 130- to 140-amino-acid motif termed the SET domain, which was recently implicated in histone H3 lysine-specific methylation activities. Indeed, recombinant ALR-1, HALR, and immunopurified ASCOM exhibit very weak but specific H3-lysine 4 methylation activities in vitro, and transactivation by retinoic acid receptor appears to involve ligand-dependent recruitment of ASCOM and subsequent transient H3-lysine 4 methylation of the promoter region in vivo. Thus, ASCOM may represent a distinct coactivator complex of nuclear receptors. Further characterization of ASCOM will lead to a better understanding of how nuclear receptors and other transcription factors mediate transcriptional activation
Expression of CD99 in Multiple Myeloma: A Clinicopathologic and Immunohistochemical Study of 170 Cases
Oxidation state control of solution-processed vanadium oxide thin-films and resistive switching of VO2 thin-film in a metastable state
Nectarine promotes longevity in Drosophila melanogaster
Fruits containing high antioxidant capacities and other bioactivities are ideal for promoting longevity and healthspan. However, few fruits are known to improve the survival and healthspan in animals, let alone the underlying mechanisms. Here we investigate the effect of nectarine, a globally consumed fruit, on lifespan and healthspan in Drosophila melanogaster. Wild-type flies were fed the standard, dietary restriction (DR) or high fat diets supplemented with 0–4% nectarine extract. We measured lifespan, food intake, locomotor activity, fecundity, gene expression changes, and oxidative damage indicated by the level of 4-Hydroxynonenal-protein adduct in these flies. We also measured lifespan, locomotor activity and oxidative damage of sod1 mutant flies on the standard diet supplemented with 0–4% nectarine. Supplementation of 4% nectarine extended lifespan, increased fecundity and decreased expression of some metabolic genes, including a key gluconeogenesis gene PEPCK, and oxidative stress response genes, including peroxiredoxins, in female wild-type flies fed the standard, DR or high fat diet. Nectarine reduced oxidative damage in wild-type females fed the high fat diet. Moreover, nectarine improved the survival and reduced oxidative damage in female sod1 mutant flies. Together, these findings suggest that nectarine promotes longevity and healthspan partly through modulating glucose metabolism and reducing oxidative damage