Search results for "differentiation"

R&D, Competition and Growth with Human Capital Accumulation Revisited

2012

In this paper, we have presented a generalization of Bucci's (2003) model in which have disentangled the monopolistic mark-up in the intermediate goods sector, the intermediate goods share in the final output and the returns to specialization in order to have a better measurement of competition. Indeed, unlike Bucci (2003), in our model, the measure of competition is completely independent of the intermediate goods share in the final output and the returns to specialization. Our main finding is that, unlike Bucci (2003), we show that the competition does not play any role in growth. This result is explained by the complementarity of innovation and human capital assumed in the research produ…

Antiproliferative agents that interfere with the cell cycle at the G(1)-->S transition: further development and characterization of a small library o…

2008

In this continuation of our research on derivatives containing the stilbene privileged structure or that are derived from it, we report the results of further studies carried out on the previously initiated collection of compounds. We used a parallel synthetic approach to rapidly obtain small sets of compounds and started the annotation of the library in progress by calculating some physicochemical properties to be eventually correlated with biological activities. A pharmacophore for the antiproliferative activity was also built to summarize the features of the library. We evaluated the antiproliferative and pro-apoptotic activities of all compounds as well as the cell-cycle effects of some…

Identification of a Terphenyl Derivative that Blocks the Cell Cycle in the G0−G1 Phase and Induces Differentiation in Leukemia Cells

2006

To further explore the SAR of resveratrol-related trans-stilbene derivatives, here we describe the synthesis of (a) a series of 3,5-dimethoxy analogues in which a variety of substituents were introduced at positions 2', 3', 4', and 5' of the stilbene scaffold and (b) a second group of derivatives (2-phenylnaphthalenes and terphenyls) that incorporate a phenyl ring as a bioisosteric replacement of the stilbene alkenyl bridge. We thoroughly characterized all of the new compounds with respect to their apoptosis-inducing activity and their effects on the cell cycle. One of the new derivatives, 13g, behaved differently from the others, as it was able to block the cell cycle in the G(0)-G(1) phas…

THE SMALL PROTEIN TRPM MODULATES MORPHO-PHYSIOLOGICAL DIFFERENTIATION IN THE MODEL ACTINOMYCETE STREPTOMYCES COELICOLOR A3(2)

2017

BACKGROUNDS TrpM, a small protein of 63 amino acids, modulates tryptophan (Trp) metabolism and morpho-physiological differentiation in the filamentous bacterium Streptomyces coelicolor A3(2), a model organism for antibiotic production and cell differentiation. Indeed, the trpM knock-out mutant strain is characterized by a delayed growth on minimal medium, smaller aerial hyphae, and reduction of both spore and antibiotic actinorhodin production in comparison with the wild-type strain. These observations were in agreement with proteomic analyses which highlighted a role for TrpM in controlling i) Trp production through Trp precursor availability and, thus ii) bacterial growth and morpho-physi…

The small protein TrpM modulates morpho-physiological differentiation in Streptomyces coelicolor

2017

TrpM, a small protein of 63 amino acids, is encoded by a gene of the trpCMBA locus involved in tryptophan biosynthesis in the model actinomycete Streptomyces coelicolor. Indeed, the trpM knock-out mutant strain is characterized by a delayed growth on minimal medium, smaller aerial hyphae, and reduction of both spore and antibiotic actinorhodin production in comparison with the wild-type strain. These observations are in agreement with proteomic analyses which highlighted a role for TrpM in controlling i) tryptophan production through precursor availability and, thus ii) bacterial growth and morpho-physiological differentiation. To further elucidate the role of TrpM, a S. coelicolor trpM kno…

A small protein is involved in tryptophan biosynthesis and morpho-physiological differentiation in Streptomyces coelicolor

2015

A small protein is involved in tryptophan biosynthesis and morpho-physiological differentiation in Streptomyces coelicolor

A "fat" Streptomycete strain overproduces antibiotics

Epigenetic influence on Streptomyces coelicolor morphological and physiological differentiation

2017

DNA methylation is an epigenetic modification regulating many aspects of biological processes; for instance, in bacteria adenine methylation is well known to be associated with DNA repair and coordination of replication, while the role of cytosine methylation has been elucidated only in a few examples. Streptomyces coelicolor is a mycelial soil microorganism, producer of several antibiotics, with a complex life cycle that includes three different cell types: unigenomic spores, a compartmentalized mycelium (MI) and a multinucleated mycelium (MII). The main objective of this study was to investigate the role of DNA cytosine methylation along the morphological and physiological differentiation…

The small protein SCO2038 controls Streptomyces coelicolor differentiation by modulating tryptophan biosynthesis

2015

Background In Streptomyces coelicolor amino acid metabolism is an important clue of the morphological and physiological differentiation program and, differently from other bacteria, the expression of amino acid biosynthetic genes is not subjected to endproduct negative regulation. In some amino acid biosynthetic gene clusters, such as tryptophan, histidine and proline, small orfs (about 100-300 nucleotides) were identified. These small orfs, such as sco2038, encode proteins whose cellular role have to be elucidated to highlight possible novel and crucial molecular mechanisms controlling amino acid synthesis and, thus, differentiation program. Objectives The aims of this work are: 1. the und…

The Marine Sponge-Derived Inorganic Polymers, Biosilica and Polyphosphate, as Morphogenetically Active Matrices/Scaffolds for the Differentiation of …

2014

The two marine inorganic polymers, biosilica (BS), enzymatically synthesized from ortho-silicate, and polyphosphate (polyP), a likewise enzymatically synthesized polymer consisting of 10 to >100 phosphate residues linked by high-energy phosphoanhydride bonds, have previously been shown to display a morphogenetic effect on osteoblasts. In the present study, the effect of these polymers on the differential differentiation of human multipotent stromal cells (hMSC), mesenchymal stem cells, that had been encapsulated into beads of the biocompatible plant polymer alginate, was studied. The differentiation of the hMSCs in the alginate beads was directed either to the osteogenic cell lineage by …