11 research outputs found

    SFRP-mediated Wnt sequestration as a potential therapeutic target for Alzheimer's disease

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    The extracellular ligand, Wnt, and its receptors are involved in sign al transduction and play an important role in axis formation and neural development. In neurodegenerative disorders such as Alzheimer's disease (AD), a decrease of the intracellular Wnt effector, ß-catenin, has been linked to amyloid-ß-peptide-induced neurotoxicity. Despite this knowledge, targeting Wnt inhibitors as potential biomarkers has not been explored, and harnessing Wnt activators as therapeutic candidates remains largely not investigated. A wide acting family of Wnt mediators, secreted frizzled-related proteins (sFRPs), has not been probed so far as molecular indicators of disease occurrence and progression of Alzheimer's. Unlike the effect of the Dickkopf (DKK) family of Wnt antagonists on AD, the sFRP molecules have a more pleiotropic impact on the Wnt signaling cascade and probably have a far-reaching involvement in neurodegeneration. The role of sFRPs has been poorly described in AD, and in this review, we analyze the present status of the role of sFRPs on neurodegeneration, their likely involvement, and potential implications in treatment modalities of AD. This information would provide valuable clues for the development of potential therapeutic targets for aberrant neurodegenerative disorders

    Multifunctional Properties of Chicken Embryonic Prenatal Mesenchymal Stem Cells- Pluripotency, Plasticity, and Tumor Suppression

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    The chick embryo represents an accessible and economical in vivo model, which has long been used in developmental biology, gene expression analysis, and loss/gain of function experiments. In the present study, we assessed and characterized bone marrow derived mesenchymal stem cells from prenatal day 13 chicken embryos (chBMMSCs) and determined some novel properties. After assessing the mesenchymal stem cell (MSC) properties of these cells by the presence of their signature markers (CD 44, CD 73, CD 90, CD 105, and vimentin), we ascertained a very broad spectrum of multipotentiality as these MSCs not only differentiated into the classic tri-lineages of MSCs but also into ectodermal, endodermal, and mesodermal lineages such as neuron, hepatocyte, islet cell, and cardiac. In addition to wide plasticity, we detected the presence of several pluripotent markers such as Oct4, Sox2, and Nanog. This is the first study characterizing prenatal chBMMSCs and their ability to not only differentiate into mesenchymal lineages but also into all the germ cell layer lineages. Furthermore, our studies indicate that prenatal chBMMSCs derived from the chick provide an excellent model for multi-lineage development studies because of their broad plasticity and faithful reproduction of MSC traits as seen in the human. Here, we also present evidence for the first time that media derived from prenatal chBMMSC cultures have an anti-tumorigenic, anti-migratory, and pro-apoptotic effect on human tumors cells acting through the Wnt-ß-catenin pathway. These data confirm that chBMMSCs are enriched with factors in their secretome that are able to destroy tumor cells. This suggests a commonality of properties of MSCs across species between human and chicken

    Inherent propensity of amnion-derived mesenchymal stem cells towards endothelial lineage: Vascularization from an avascular tissue

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    One of the most pressing problems in injury is wound healing and blood vessel formation. The amniotic membrane is important in clinical applications as it is pro-angiogenic, anti-fibrotic and anti-scarring and has low immunogenicity. In this study, we characterized amniotic membrane mesenchymal stem cells (AMMSCs) by their trademark mesenchymal stem cell (MSC) signature and profiled for embryonic pluripotency markers namely alkaline phosphatase, Oct4, Sox2, Nanog, SSEA3 and 4, and Klf4 by RT-PCR and nuclear localization of Oct4 and Nanog by immunocytochemistry. The amnion, although avascular, contains pro-angiogenic factors such as type I, III, IV and V collagen, laminin, and fibronectin in the extra cellular matrix. We, therefore, hypothesized that AMMSCs is pro-angiogenic. Thus, we demonstrate that MSCs derived from the amnion have a natural ability to initiate endothelialization and angiogenesis in vitro. Our results using a wound scratch assay and angiogenesis on Matrigel suggest a pro-angiogenic property of AMMSCs. We also show that native, uninduced AMMSCs are able to form endothelial rings in Matrigel. Further evidence was provided by RT-PCR showing the expression of pro-angiogenic factors such as Tie2, Ang1, VEGF, VEGFR, vWF, KDR and Flt4 in native AMMSCs. Taken together, our results suggest that MSCs from an avascular amnion have an inherent propensity for promoting angiogenesis and could be an ideal choice in wound healing, stroke and ischemic diseases that require rapid vascularization and tissue restoration. © 2012 Elsevier Ltd. All rights reserved

    Optimization of parameters of chemical spray pyrolysis technique to get n and p-type layers of SnS

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    SnS thin films were prepared using automated chemical spray pyrolysis (CSP) technique. Single-phase, p-type, stoichiometric, SnS films with direct band gap of 1.33 eV and having very high absorption coefficient (N105/cm) were deposited at substrate temperature of 375 °C. The role of substrate temperature in determining the optoelectronic and structural properties of SnS films was established and concentration ratios of anionic and cationic precursor solutions were optimized. n-type SnS samples were also prepared using CSP technique at the same substrate temperature of 375 °C, which facilitates sequential deposition of SnS homojunction. A comprehensive analysis of both types of films was done using x-ray diffraction, energy dispersive x-ray analysis, scanning electron microscopy, atomic force microscopy, optical absorption and electrical measurements. Deposition temperatures required for growth of other binary sulfide phases of tin such as SnS2, Sn2S3 were also determinedCochin University of Science and TechnologyThin Solid Films 518 (2010) 4370–437

    Non-destructive evaluation of carrier transport properties in CuInS2 and CuInSe2 thin films using photothermal deflection technique

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    Photothermal deflection technique (PTD) is a non-destructive tool for measuring the temperature distribution in and around a sample, due to various non-radiative decay processes occurring within the material. This tool was used to measure the carrier transport properties of CuInS2 and CuInSe2 thin films. Films with thickness <1 μm were prepared with different Cu/In ratios to vary the electrical properties. The surface recombination velocity was least for Cu-rich films (5×105 cm/s for CuInS2, 1×103 cm/s for CuInSe2), while stoichiometric films exhibited high mobility (0.6 cm2/V s for CuInS2, 32 cm2/V s for CuInSe2) and high minority carrier lifetime (0.35 μs for CuInS2, 12 μs for CuInSe2Cochin University of Science and TechnologyThin Solid Films 518 (2010) 1767–177

    Selective estrogen receptor-beta (SERM-beta) compounds modulate raphe nuclei tryptophan hydroxylase-1 (TPH-1) mRNA expression and cause antidepressant-like effects in the forced swim test

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    Estrogen acts through two molecularly distinct receptors termed estrogen receptor alpha (ERa) and estrogen receptor beta (ERß) which bind estradiol with similar affinities and mediate the effects of estrogen throughout the body. ERa plays a major role in reproductive physiology and behavior, and mediates classic estrogen signaling in such tissues as the uterus, mammary gland, and skeleton. ERß, however, modulates estrogen signaling in the ovary, the immune system, prostate, gastrointestinal tract, and hypothalamus, and there is some evidence that ERß can regulate ERa activity. Moreover, ERß knockout studies and receptor distribution analyses in the CNS suggest that this receptor may play a role in the modulation of mood and cognition. In recent years several ERß-specific compounds (selective estrogen receptor beta modulators; SERM-beta) have become available, and research suggests potential utility of these compounds in menopausal symptom relief, breast cancer prevention, diseases that have an inflammatory component, osteoporosis, cardiovascular disease, and inflammatory bowel disease, as well as modulation of mood, and anxiety. Here we demonstrate an antidepressant-like effect obtained using two SERM-beta compounds, SERM-beta1 and SERM-beta2. These compounds exhibit full agonist activity at ERß in a cell based estrogen response element (ERE) transactivation assay. SERM-beta1 and 2 are non-proliferative with respect to breast as determined using the MCF-7 breast cancer cell-based assay and non-proliferative in the uterus as determined by assessing the effects of SERM-beta compounds on immature rat uterine weight and murine uterine weight. In vivo SERM-beta1 and 2 are brain penetrant and display dose dependent efficacy in the murine dorsal raphe assays for induction of tryptophan hydroxylase mRNA and progesterone receptor protein. These compounds show activity in the murine forced swim test and promote hippocampal neurogenesis acutely in rats. Taken together these data suggest that ERß may play an important role in modulating mood and the ERß specific compounds described herein will be useful tools for probing the utility of an ERß agonist for treating neuroendocrine-related mood disturbance and menopausal symptoms. Highlights: SERM-beta1 and 2 are selective, non-proliferative, brain penetrant ERß modulators. SERM-beta compounds modulated the levels of TPH1 mRNA and PR protein in raphe nuclei. SERM-beta compounds promoted neurogenesis and showed antidepressant activity in vivo. © 2012 Elsevier Ltd. All rights reserved

    Generation of islet-like cell aggregates from human non-pancreatic cancer cell lines

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    To explore a novel source for the derivation of islets, we examined the differentiation potential of human non-pancreatic cancer cell lines, HeLa (cervical carcinoma cell line) and MCF-7 (breast cancer cell line). These cells were subjected to a serum-free, three-step sequential differentiation protocol which gave two distinct cell populations: single cells and cellular aggregates. Subsequent analysis confirmed their identity as pancreatic acinar cells and islet-like cell aggregates (ICAs), as evidenced by amylase secretion and diphenylthiocarbazone staining respectively. Reverse transcriptase-PCR and immunocytochemistry assessment of the ICAs revealed the expression of pancreatic specific markers Ngn-3, Glut-2, Pax-6 and Isl-1. These ICAs secreted insulin in response to glucose challenge, confirming their functionality. We propose that ICAs generated from HeLa and MCF-7 cell lines could form a promising in vitro platform of human islet equivalents (hIEQs) for diabetes research

    The preclinical efficacy, selectivity and pharmacologic profile of MK-5932, an insulin-sparing selective glucocorticoid receptor modulator

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    Glucocorticoids are used widely in the treatment of inflammatory diseases, but use is accompanied by a significant burden of adverse effects. It has been hypothesized that gene- and cell-specific regulation of the glucocorticoid receptor by small molecule ligands could be translated into a therapeutic with an improved risk-benefit profile. MK-5932 is a highly selective glucocorticoid receptor modulator that is anti-inflammatory in vivo with an improved profile on glucose metabolism: Bungard et al. (2011). Bioorg. Med. Chem. 19, 7374-7386. Here we describe the full biological profile of MK-5932. Cytokine production following lipopolysaccharide (LPS) challenge was blocked by MK-5932 in both rat and human whole blood. Oral administration reduced inflammatory cytokine levels in the serum of rats challenged with LPS. MK-5932 was anti-inflammatory in a rat contact dermatitis model, but was differentiated from 6-methylprednisolone by a lack of elevation of fasting insulin or glucose levels after 7 days of dosing, even at high exposure levels. In fact, animals in the vehicle group were consistently hyperglycemic at the end of the study, and MK-5932 normalized glucose levels in a dose-dependent manner. MK-5932 was also anti-inflammatory in the rat collagen-induced arthritis and adjuvant-induced arthritis models. In healthy dogs, oral administration of MK-5932 exerted acute pharmacodynamic effects with potency comparable to prednisone, but with important differences on neutrophil counts, again suggestive of a dissociated profile. Important gaps in our understanding of mechanism of action remain, but MK-5932 will be a useful tool in dissecting the mechanisms of glucose dysregulation by therapeutic glucocortiocids. © 2013 Elsevier B.V
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