scholarly journals Forced Expression of Keratin 16 Alters the Adhesion, Differentiation, and Migration of Mouse Skin Keratinocytes

2000 ◽  
Vol 11 (10) ◽  
pp. 3315-3327 ◽  
Author(s):  
Matthew Wawersik ◽  
Pierre A. Coulombe
Keyword(s):  
Mouse Skin ◽  
Cellular Level ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Keratin 16 ◽  
Skin Keratinocytes ◽  
Steady State Levels ◽  
And Migration ◽  
Mouse Skin Keratinocytes ◽  
The Impact

Injury to the skin results in an induction of keratins K6, K16, and K17 concomitant with activation of keratinocytes for reepithelialization. Forced expression of human K16 in skin epithelia of transgenic mice causes a phenotype that mimics several aspects of keratinocyte activation. Two types of transgenic keratinocytes, with forced expression of either human K16 or a K16-C14 chimeric cDNA, were analyzed in primary culture to assess the impact of K16 expression at a cellular level. High K16-C14-expressing and low K16-expressing transgenic keratinocytes behave similar to wild type in all aspects tested. In contrast, high K16-expressing transgenic keratinocytes show alterations in plating efficiency and calcium-induced differentiation, but proliferate normally. Migration of keratinocytes is reduced in K16 transgenic skin explants compared with controls. Finally, a subset of high K16-expressing transgenic keratinocytes develops major changes in the organization of keratin filaments in a time- and calcium concentration-dependent manner. These changes coincide with alterations in keratin content while the steady-state levels of K16 protein remain stable. We conclude that forced expression of K16 in progenitor skin keratinocytes directly impacts properties such as adhesion, differentiation, and migration, and that these effects depend upon determinants contained within its carboxy terminus.

Early changes in gene expression induced by tumour promoters in mouse skin keratinocytes

1987 ◽  
Vol 23 (11) ◽  
pp. 1736-1737
Author(s):  
S. Bohm ◽  
C. Pereswetoff-Morath ◽  
A. Berghard ◽  
K. Hyvönen ◽  
R. Toftgård
Keyword(s):  
Gene Expression ◽  
Mouse Skin ◽  
Skin Keratinocytes ◽  
Tumour Promoters ◽  
Mouse Skin Keratinocytes

scholarly journals Using a Multi-Stage hESC Model to Characterize BDE-47 Toxicity During Neurogenesis

2019 ◽  
Vol 171 (1) ◽  
pp. 221-234 ◽  
Author(s):  
Hao Chen ◽  
Helia Seifikar ◽  
Nicholas Larocque ◽  
Yvonne Kim ◽  
Ibrahim Khatib ◽  
...  
Keyword(s):  
Neural Development ◽  
Polybrominated Diphenyl Ethers ◽  
Neuronal Development ◽  
Embryonic Stem ◽  
Cellular Level ◽  
Environmental Chemicals ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Neurodevelopmental Toxicity

Abstract Although the ramifications associated with polybrominated diphenyl ethers (PBDEs) exposures during human pregnancy have yet to be determined, increasing evidence in humans and animal models suggests that these compounds cause neurodevelopmental toxicity. Human embryonic stem cells (hESCs) models can be used to study the effects of environmental chemicals throughout the successive stages of neuronal development. Here, using a hESC differentiation model, we investigated the effects of common PBDE congeners (BDE-47 or -99) on the successive stages of early neuronal development. First, we determined the points of vulnerability to PBDEs across 4 stages of in vitro neural development by using assays to assess for cytotoxicity. Differentiated neural progenitors were identified to be more sensitive to PBDEs than their less differentiated counterparts. In follow-up investigations, we observed BDE-47 to inhibit functional processes critical for neurogenesis (eg, proliferation, expansion) in hESC-derived neural precursor cells (NPCs) at sub-lethal concentrations. Finally, to determine the mechanism(s) underlying PBDE-toxicity, we conducted global transcriptomic and methylomic analyses of BDE-47. We identified 589 genes to be differentially expressed due to BDE-47 exposure, including molecules involved in oxidative stress mediation, cell cycle, hormone signaling, steroid metabolism, and neurodevelopmental pathways. In parallel analyses, we identified a broad significant increase in CpG methylation. In summary our results suggest, on a cellular level, PBDEs induce human neurodevelopmental toxicity in a concentration-dependent manner and sensitivity to these compounds is dependent on the developmental stage of exposure. Proposed mRNA and methylomic perturbations may underlie toxicity in early embryonic neuronal populations.

scholarly journals Protective Effect of Silymarin against Rapamycin-induced Apoptosis and Proliferation Inhibition in Endothelial Progenitor Cells

2015 ◽  
Vol 10 (2) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Peng Zhang ◽  
Guohua Han ◽  
Pei Gao ◽  
Kun Qiao ◽  
Yusheng Ren ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Mononuclear Cells ◽  
Control Group ◽  
Dependent Manner ◽  
Endothelial Progenitor ◽  
Concentration Dependent Manner ◽  
Inhibition Of Proliferation ◽  
And Migration ◽  
Proliferation And Migration

For this study, peripheral blood samples were collected from human volunteers. Mononuclear cells (MNC) were separated by density centrifugation and were induced to differentiate into endothelial progenitor cells (EPCs) in vitro. Different concentrations of rapamycin and silymarin were introduced to the EPCs over 24 hours and then EPCs were analyzed for proliferation, migration, apoptosis and angiogenesis. Compared with the control group, rapamycin (1, 10, 100 ng/mL) inhibited the proliferation and migration of EPCs in a concentration dependent manner ( P<0.05). Silymarin (50, 100 μg/mL) enhanced the proliferation and migration of EPCs and inhibited apoptosis in a concentration dependent manner ( P<0.05). By adding rapamycin (1 ng/mL) and silymarin (25, 50, 100 μg/mL) over 24 hours, silymarin inhibited the pro-apoptotic effect of rapamycin on EPCs, and reversed the inhibition of proliferation, migration and angiogenesis of EPCs by rapamycin ( P<0.05).

The cytoprotective effects of bilirubin and biliverdin on rat hepatocytes and human erythrocytes and the impact of albumin

1991 ◽  
Vol 69 (12) ◽  
pp. 828-834 ◽  
Author(s):  
Tai-Wing Wu ◽  
Doug Carey ◽  
Jun Wu ◽  
Hiroshi Sugiyama
Keyword(s):  
Rat Hepatocytes ◽  
Human Erythrocytes ◽  
Red Cells ◽  
Peroxyl Radicals ◽  
Blood Levels ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Hepatocyte Necrosis ◽  
The Impact ◽  
First Time

The hypothesis that unconjugated bilirubin and biliverdin are cytoprotective antioxidants has been examined for the first time in systems containing cells. In primary rat hepatocytes exposed to xanthine oxidase and hypoxanthine, bilirubin (0–60 μM) failed to prolong cell survival. In contrast, biliverdin (20–100 μM) markedly delayed hepatocyte necrosis in a concentration-dependent manner. When 0.3 mM of albumin was present, bilirubin (0–50 μM) became protective of hepatocytes, while biliverdin was less dramatically enhanced in its cytoprotective effect. In human erythrocytes exposed to peroxyl radicals, bilirubin and biliverdin inhibited 50% cell lysis at lower concentrations than Trolox and ascorbate, respectively. Albumin alone appeared less cytoprotective in red cells than in hepatocytes, but its presence enhanced the effects of both pigments on erythrocytes. Of probable physiologic relevance, bilirubin with albumin present or biliverdin alone protected hepatocytes substantially (and to a lesser extent red cells) at the normal blood levels of bilirubin (3.4–26 μM). Moreover, the fact that the pigments are cytoprotective at higher bilirubin levels (e.g., 50–100 μM) tempts the speculation that they may be circulating cytoprotectors of overlooked importance in jaundice.Key words: cytoprotection, biliverdin, bilirubin, albumin.

Differential inhibition of inflammatory cytokine release from cultured alveolar macrophages from smokers and non smokers by No2

1997 ◽  
Vol 16 (10) ◽  
pp. 577-588 ◽  
Author(s):  
Tiziana Dandrea ◽  
Ba Tu ◽  
Anders Blomberg ◽  
Thomas Sandström ◽  
Magnus Sköld ◽  
...  
Keyword(s):  
Steady State ◽  
Alveolar Macrophages ◽  
Exposure Model ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Tnf Α ◽  
Dependent Inhibition ◽  
Steady State Levels ◽  
Dose Dependent

Human alveolar macrophages (AMs) obtained from smokers and non-smokers by bronchoalveolar lavage (BAL) were subjected to various concentrations of NO2 in an inverted monolayer exposure model. Culture super natants were collected 4 h after the exposure and assayed for secreted TNF-α, IL-1β, IL-8 and MIP-1α. The steady state levels of the mRNAs for these cytokines were also analysed in the cells. The adherence of BAL cells to plastic prior to exposure to the gas elevated the steady state mRNA levels of all four cytokines tested in smoker's cells and that of TNF-α and IL-1β, but not IL-8 (MIP-1α not tested), in non-smoker's cells. Interestingly, adherent cells from non-smokers released circa 15-, 3-,1.5- and 3-fold the amounts of IL-1β, IL-8, TNF-α and MIP-1α, respectively, than smoker's cells during control incubation or exposure to air. A 20 min exposure to NO2 (5 or 20 p.p.m.) did not increase the secretion of any of the cytokines from either cell type. In contrast, NO2 caused a concentration- dependent inhibition of the secretion of all cytokines except IL-1β from smoker's cells. Additionally, NO2 greatly diminished the release of all cytokines in response to further treatment with lipopolysaccharide (LPS). In contrast, only the secretion of TNF-α from non-smoker's cells was inhibited by the gas in a concentration- dependent manner, whilst LPS-induced secretion of the cytokines was not affected by the gas. The steady state levels of the respective mRNAs for each of the cytokines were not significantly affected in smoker's cells by exposure to NO2, except for a negative, dose-dependent trend in the case of TNF-α. Nitrogen dioxide also failed to elevate the levels of the mRNAs in non-smoker's cells but, again, tended to diminish the levels, particularly of IL-1β mRNA. However, exposure to the gas inhibited LPS- induced accumulation of cytokine mRNAs in smoker's cells only. The data suggest that macrophage-derived cytokine mediators of the sepsis response may not play a role in the generation of NO2-induced inflammation in the human lung. Conversely, the gas seems to non-specifically inhibit the release and/or production of cytokines, particularly from smoker's cells, at the post-transcrip tional level, and impairs the ability of the cells to increase the transcription and release of the cytokines in response to bacterial LPS. The fact that NO2 seriously impaired the already diminished capacity of smoker's cells to release several important pro-inflammatory cytokines, both under control conditions and in response to LPS, strongly suggest that the inhalation of NO2 in cigarette smoke may contribute to impairing host defence against infection in the lung.

scholarly journals Cell-free Expression of Proton-Coupled Folate Transporter in the Presence of Nanodiscs

2021 ◽  
Author(s):  
Hoa Quynh Do ◽  
Carla M Bassil ◽  
Elizabeth I Andersen ◽  
Michaela Jansen
Keyword(s):  
Tumor Cells ◽  
Plasma Membranes ◽  
In Vitro Translation ◽  
Translation System ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
E Coli ◽  
Membrane Scaffold ◽  
The Impact

The Proton-Coupled Folate Transporter (PCFT) is a transmembrane transport protein that controls the absorption of dietary folates in the small intestine. PCFT also mediates uptake of chemotherapeutically used antifolates into tumor cells. PCFT has been identified within lipid rafts observed in phospholipid bilayers of plasma membranes, a micro environment that is altered in tumor cells. The present study aimed at investigating the impact of different lipids within Lipid-protein nanodiscs (LPNs), discoidal lipid structures stabilized by membrane scaffold proteins, to yield soluble PCFT expression in an E. coli lysate-based cell-free transcription/translation system. In the absence of detergents or lipids, we observed PCFT quantitatively as precipitate in this system. We then explored the ability of LPNs to support solubilized PCFT expression when present during in-vitro translation. LPNs consisted of either dimyristoyl phosphatidylcholine (DMPC), palmitoyl-oleoyl phosphatidylcholine (POPC), or dimyristoyl phosphatidylglycerol (DMPG). While POPC did not lead to soluble PCFT expression, both DMPG and DMPC supported PCFT translation directly into LPNs, the latter in a concentration dependent manner. The results obtained through this study provide insights into the lipid preferences of PCFT. Membrane-embedded or solubilized PCFT will enable further studies with diverse biophysical approaches to enhance the understanding of the structure and molecular mechanism of folate transport through PCFT.

scholarly journals (R,S)-Ketamine Metabolites (R,S)-norketamine and (2S,6S)-hydroxynorketamine Increase the Mammalian Target of Rapamycin Function

2014 ◽  
Vol 121 (1) ◽  
pp. 149-159 ◽  
Author(s):  
Rajib K. Paul ◽  
Nagendra S. Singh ◽  
Mohammed Khadeer ◽  
Ruin Moaddel ◽  
Mitesh Sanghvi ◽  
...  
Keyword(s):  
Parent Compound ◽  
Mammalian Target Of Rapamycin ◽  
Mtor Pathway ◽  
Target Of Rapamycin ◽  
Dependent Manner ◽  
Α7 Nicotinic Acetylcholine Receptor ◽  
Concentration Dependent Manner ◽  
Pheochromocytoma Cells ◽  
The Impact

Abstract Background: Subanesthetic doses of (R,S)-ketamine are used in the treatment of neuropathic pain and depression. In the rat, the antidepressant effects of (R,S)-ketamine are associated with increased activity and function of mammalian target of rapamycin (mTOR); however, (R,S)-ketamine is extensively metabolized and the contribution of its metabolites to increased mTOR signaling is unknown. Methods: Rats (n = 3 per time point) were given (R,S)-ketamine, (R,S)-norketamine, and (2S,6S)-hydroxynorketamine and their effect on the mTOR pathway determined after 20, 30, and 60 min. PC-12 pheochromocytoma cells (n = 3 per experiment) were treated with escalating concentrations of each compound and the impact on the mTOR pathway was determined. Results: The phosphorylation of mTOR and its downstream targets was significantly increased in rat prefrontal cortex tissue by more than ~2.5-, ~25-, and ~2-fold, respectively, in response to a 60-min postadministration of (R,S)-ketamine, (R,S)-norketamine, and (2S,6S)-hydroxynorketamine (P &lt; 0.05, ANOVA analysis). In PC-12 pheochromocytoma cells, the test compounds activated the mTOR pathway in a concentration-dependent manner, which resulted in a significantly higher expression of serine racemase with ~2-fold increases at 0.05 nM (2S,6S)-hydroxynorketamine, 10 nM (R,S)-norketamine, and 1,000 nM (R,S)-ketamine. The potency of the effect reflected antagonistic activity of the test compounds at the α7-nicotinic acetylcholine receptor. Conclusions: The data demonstrate that (R,S)-norketamine and (2S,6S)-hydroxynorketamine have potent pharmacological activity both in vitro and in vivo and contribute to the molecular effects produced by subanesthetic doses of (R,S)-ketamine. The results suggest that the determination of the mechanisms underlying the antidepressant and analgesic effects of (R,S)-ketamine requires a full study of the parent compound and its metabolites.

scholarly journals Interaction of Graphene Oxide Modified with Linear and Branched PEG with Monocytes Isolated from Human Blood

Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 126
Author(s):  
Pavel Khramtsov ◽  
Maria Bochkova ◽  
Valeria Timganova ◽  
Anton Nechaev ◽  
Sofya Uzhviyuk ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Immune Cells ◽  
Human Peripheral Blood ◽  
Oxide Surface ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Composition And Structure ◽  
Luminescent Signal ◽  
Ros Formation ◽  
The Impact

Multiple graphene-based therapeutics have recently been developed, however potential risks related to the interaction between nanomaterials and immune cells are still poorly understood. Therefore, studying the impact of graphene oxide on various populations of immune cells is of importance. In this work, we aimed to investigate the effects of PEGylated graphene oxide on monocytes isolated from human peripheral blood. Graphene oxide nanoparticles with lateral sizes of 100–200 nm and 1–5 μm were modified with linear and branched PEG (GO-PEG). Size, elemental composition, and structure of the resulting nanoparticles were characterized. We confirmed that PEG was successfully attached to the graphene oxide surface. The influence of GO-PEG on the production of reactive oxygen species (ROS), cytokines, phagocytosis, and viability of monocytes was studied. Uptake of GO-PEG by monocytes depends on PEG structure (linear or branched). Branched PEG decreased the number of GO-PEG nanoparticles per monocyte. The viability of monocytes was not altered by co-cultivation with GO-PEG. GO-PEG decreased the phagocytosis of Escherichia coli in a concentration-dependent manner. ROS formation by monocytes was determined by measuring luminol-, lucigenin-, and dichlorodihydrofluorescein-dependent luminescence. GO-PEG decreased luminescent signal probably due to inactivation of ROS, such as hydroxyl and superoxide radicals. Some types of GO-PEG stimulated secretion of IL-10 by monocytes, but this effect did not correlate with their size or PEG structure.

scholarly journals Size of Cells and Physicochemical Properties of Membranes are Related to Flavor Production during Sake Brewing in the Yeast Saccharomyces cerevisiae

Membranes ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 440
Author(s):  
Tsuyoshi Yoda ◽  
Tomoaki Saito
Keyword(s):  
Isoamyl Alcohol ◽  
Lipid Vesicles ◽  
Caproic Acid ◽  
Yeast Cells ◽  
Dependent Manner ◽  
Yeast Saccharomyces Cerevisiae ◽  
Concentration Dependent Manner ◽  
Generalized Polarization ◽  
Flavor Components ◽  
The Impact

Ethyl caproate (EC) and isoamyl acetate (IA) are key flavor components of sake. Recently, attempts have been made to increase the content of good flavor components, such as EC and IA, in sake brewing. However, the functions of EC and IA in yeast cells remain poorly understood. Therefore, we investigated the effects of EC and IA using cell-sized lipid vesicles. We also investigated lipid vesicles containing EC and/or caproic acid (CA) as well as IA and/or isoamyl alcohol (IAA). CA and IAA are precursors of EC and IA, respectively, and are important flavors in sake brewing. The size of a vesicle is influenced by flavor compounds and their precursors in a concentration-dependent manner. We aimed to establish the conditions in which the vesicles contained more flavors simultaneously and with different ratios. Interestingly, vesicles were largest in a mixture of 50% of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) with 25% EC and 25% CA or a mixture of 50% DOPC with 25% IA and 25% IAA. The impact of flavor additives on membrane fluidity was also studied using Laurdan generalized polarization. During the production process, flavors may regulate the fluidity of lipid membranes.

Sign in / Sign up

Export Citation Format

Share Document