Estrogen, angiogenesis, immunity and cell metabolism: Solving the puzzle

Estrogen plays an important role in the regulation of cardiovascular physiology and the immune system by inducing direct effects on multiple cell types including immune and vascular cells. Sex steroid hormones are implicated in cardiovascular protection, including endothelial healing in case of arterial injury and collateral vessel formation in ischemic tissue. Estrogen can exert potent modulation effects at all levels of the innate and adaptive immune systems. Their action is mediated by interaction with classical estrogen receptors (ERs), ER\u3b1 and ER\u3b2, as well as the more recently identified G-protein coupled receptor 30/G-protein estrogen receptor 1 (GPER1), via both genomic and non-genomic mechanisms. Emerging data from the literature suggest that estrogen deficiency in menopause is associated with an increased potential for an unresolved inflammatory status. In this review, we provide an overview through the puzzle pieces of how 17\u3b2-estradiol can influence the cardiovascular and immune systems

Proceso de Comunidades Negras (PCN)

Diese Arbeit wurde aus einer post-Entwicklungsperspektive geschrieben und versucht zu bestimmen, ob der Proceso de Comunidades Negras (PCN) als Verkörperung der post-Entwicklungsidee angesehen werden kann, wie es viele Theoretiker die diese soziale Bewegung untersucht haben attestieren. Auf der einen Seite, weisen post-Entwicklungstexte besonderen Wert auf Arturo Escobar. Auf der anderen Seite, liegt ein Schwerpunkt auf der Beschreibung des Ortes in welchem der PCN geboren wurde und weiterhin aktiv ist (die kolumbianische Pazifikregion). Obwohl der PCN in die generelle Beschreibung von post-Entwicklung passt, stellt man bei genauer Analyse fest, dass Ursprung, Mechanismen und Arbeitsweise erhebeliche Unterschiede aufweisen. Daher kann man den PCN als einen Fall von „skeptischer post-Entwicklung“ ansehen, wie es Aram Ziai getan hat.The thesis is written from a post-developmental perspective and attempts to determine if Proceso de Comunidades Negras (PCN) can be considered an embodiment of post-developmental ideas, as many scholars who study and analyzed this social movement attest. The thesis has two theoretical poles. On one hand, a review of post-developmental texts giving special priority to Arturo Escobar. On the other, a strong emphasis on the description of the place where PCN was born and continues to be active (the Colombian Pacific region). Although PCN fits into the general description of post-development, a finer observation at its origins, mechanisms and functioning highlights not only points of symmetry, but of difference. Therefore, PCN can best be considered a case of “skeptical post-development”, as depicted by Aram Ziai

The Glycolytic Enzyme PFKFB3 Is Involved in Estrogen-Mediated Angiogenesis via GPER1 s

ABSTRACT The endogenous estrogen 17b-estradiol (E2) is a key factor in promoting endothelial healing and angiogenesis. Recently, proangiogenic signals including vascular endothelial growth factor and others have been shown to converge in endothelial cell metabolism. Because inhibition of the glycolytic enzyme activator phosphofructokinase-2/fructose-2,6-bisphosphatase 3 (PFKFB3) reduces pathologic angiogenesis and estrogen receptor (ER) signaling stimulates glucose uptake and glycolysis by inducing PFKFB3 in breast cancer, we hypothesized that E2 triggers angiogenesis in endothelial cells via rapid ER signaling that requires PFKFB3 as a downstream effector. We report that treatment with the selective G protein-coupled estrogen receptor (GPER1) agonist G-1 (10 210 to 10 27 M) mimicked the chemotactic and proangiogenic effect of E2 as measured in a number of short-term angiogenesis assays in human umbilical vein endothelial cells (HUVECs); in addition, E2 treatment upregulated PFKFB3 expression in a time-and concentrationdependent manner. Such an effect peaked at 3 hours and was also induced by G-1 and abolished by pretreatment with the GPER1 antagonist G-15 or GPER1 siRNA, consistent with engagement of membrane ER. Experiments with the PFKFB3 inhibitor 3-(3-pyridinyl)-1-(4-pyridinyl)-2-propen-1-one showed that PFKFB3 activity was required for estrogen-mediated HUVEC migration via GPER1. In conclusion, E2-induced angiogenesis was mediated at least in part by the membrane GPER1 and required upregulation of the glycolytic activator PFKFB3 in HUVECs. These findings unravel a previously unrecognized mechanism of estrogen-dependent endocrine-metabolic crosstalk in HUVECs and may have implications in angiogenesis occurring in ischemic or hypoxic tissues

MBE growth and study of low-density InAs/GaAs quantum dots and wetting layer

Semiconductor quantum dots (QDs) prepared with Molecular Beam Epitaxy (MBE) represent an interesting approach to the development of single-photon sources at telecom wavelengths [1]. Structures with low QD density can be successfully prepared by using growth conditions that lead to increased cation migration length, such as relatively high QD growth temperature and/or low QD growth rate [2]; long-wavelength emission, on the other hand, may be obtained by inserting an InGaAs upper confining layer (UCL) on top of the QDs [3]. A complete picture of the properties not only of QDs but also of the wetting layer (WL) in these structures is particularly interesting since WL states have important effects on QD carriers dynamics. We present here the study of morphological, structural and optical properties of MBE-grown structures in which QDs were deposited at low growth rate (0.01 ML/s) and high growth temperature (520 ?C) and capped with InGaAs UCLs [4]. Owing to these particular design and growth parameters, the structures have QD densities of 4-5x109 cm-2 and emission wavelengths ranging from 1.20 to 1.33 ?m at 10 K. The WL properties were investigated with low temperature photoluminescence (PL) and high resolution X-Ray diffraction (XRD); the experimental WL transition energies were compared to simple model calculations of quantum energy levels. Our results show that the structural parameters extracted by XRD spectra simulations deviate from nominal values, as probably due to the growth parameters used to obtain low QD density [5]. The optical and structural properties of QDs were studied by means of PL, time-resolved PL (TRPL), Transmission Electron Microscopy (TEM) and Atomic Force Microscopy (AFM). TEM characterization was used to analyze the composition profiles in QDs, WL and UCLs; the results were related to the particular growth conditions used to prepare the structures. AFM measurements clearly evidenced on all samples bimodal distributions of QD heights that have been related to the observed double-peaked PL spectra. Optical characterization has been carried out as a function of temperature. Arrhenius plots of the integrated PL show two activation energies implying two decay processes. The first one is associated to thermal escape of carriers from the QDs to the WL states; the second one could be due to the presence of dark states, as suggested by TRPL measurements. The results of this comprehensive characterization are useful to reach an in-depth understanding of the quantum system and its potential as a source of single photons. [1] Intallura P.M., Ward M.B., et al., J Opt A-Pure Appl Op 2009, 11, 05400509. [2] Joyce P.B., Krzyzewski T.J., et al., Phys Rev B 2000, 62, 10891. [3] Alloing B., Zinoni C et al., Appl Phys Lett 2005, 86, 101908. [4] Trevisi G., Seravalli L., et al., Nanotechnology 2009, 20, 415607. [5] Seravalli L., Bocchi C., et al., submitted to J Appl Phys