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Fehsel K. Why Is Iron Deficiency/Anemia Linked to Alzheimer's Disease and Its Comorbidities, and How Is It Prevented? Biomedicines 2023; 11:2421. [PMID: 37760862 PMCID: PMC10526115 DOI: 10.3390/biomedicines11092421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 08/23/2023] [Accepted: 08/25/2023] [Indexed: 09/29/2023] Open
Abstract
Impaired iron metabolism has been increasingly observed in many diseases, but a deeper, mechanistic understanding of the cellular impact of altered iron metabolism is still lacking. In addition, deficits in neuronal energy metabolism due to reduced glucose import were described for Alzheimer's disease (AD) and its comorbidities like obesity, depression, cardiovascular disease, and type 2 diabetes mellitus. The aim of this review is to present the molecular link between both observations. Insufficient cellular glucose uptake triggers increased ferritin expression, leading to depletion of the cellular free iron pool and stabilization of the hypoxia-induced factor (HIF) 1α. This transcription factor induces the expression of the glucose transporters (Glut) 1 and 3 and shifts the cellular metabolism towards glycolysis. If this first line of defense is not adequate for sufficient glucose supply, further reduction of the intracellular iron pool affects the enzymes of the mitochondrial electron transport chain and activates the AMP-activated kinase (AMPK). This enzyme triggers the translocation of Glut4 to the plasma membrane as well as the autophagic recycling of cell components in order to mobilize energy resources. Moreover, AMPK activates the autophagic process of ferritinophagy, which provides free iron urgently needed as a cofactor for the synthesis of heme- and iron-sulfur proteins. Excessive activation of this pathway ends in ferroptosis, a special iron-dependent form of cell death, while hampered AMPK activation steadily reduces the iron pools, leading to hypoferremia with iron sequestration in the spleen and liver. Long-lasting iron depletion affects erythropoiesis and results in anemia of chronic disease, a common condition in patients with AD and its comorbidities. Instead of iron supplementation, drugs, diet, or phytochemicals that improve energy supply and cellular glucose uptake should be administered to counteract hypoferremia and anemia of chronic disease.
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Affiliation(s)
- Karin Fehsel
- Neurobiochemical Research Unit, Department of Psychiatry, Medical Faculty, Heinrich-Heine-University, 240629 Düsseldorf, Germany
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Lee JH, Song J, Kim IG, You G, Kim H, Ahn JH, Mok H. Exosome-mediated delivery of transforming growth factor-β receptor 1 kinase inhibitors and toll-like receptor 7/8 agonists for combination therapy of tumors. Acta Biomater 2022; 141:354-363. [PMID: 35007784 DOI: 10.1016/j.actbio.2022.01.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 12/27/2021] [Accepted: 01/04/2022] [Indexed: 02/07/2023]
Abstract
In this study, combination therapy with the transforming growth factor-β receptor I (TGFβRI) kinase inhibitor SD-208 and a toll-like receptor (TLR)-7/8 agonist resiquimod (R848) was examined along with serum-derived exosomes (EXOs) as versatile carriers. SD-208-encapsulated EXOs (SD-208/EXOs) and R848-encapsulated EXOs (R848/EXOs) were successfully prepared with a size of 87 ± 8 nm and 51 ± 4 nm, respectively, which were stable in aqueous solution at pH 7.4. SD-208/EXOs and R848/EXOs reduced the migration of cancer cells (B16F10 and PC-3) and triggered the release of proinflammatory cytokines from stimulated macrophages and dendritic cells, respectively. The fluorescent dye-labeled EXOs showed significantly improved penetration through the PC-3/fibroblast co-culture spheroids and enhanced accumulation in the B16F10 mouse tumor model compared with the free fluorescent dye. In addition, the combination therapy of R848/EXOs (R848 dose of 0.36 mg/kg) and SD-208/EXOs (SD-208 dose of 0.75 mg/kg) reduced tumor growth and improved survival rate at low doses in the B16F10 tumor xenograft model. Taken together, the combination therapy using the TGFβRI kinase inhibitor and TLR 7/8 agonist with EXOs may serve as a promising strategy to treat melanoma and prostate cancer. STATEMENT OF SIGNIFICANCE: Owing to the prevalence of several non-responding cancers that resist treatment, it is necessary to identify a novel combined treatment strategy with biomaterials to maximize therapeutic efficacy and minimize the undesirable side effects. In this study, we aimed to examine the use of the TGFβRI kinase inhibitor SD-208 and the TLR7/8 agonist resiquimod (R848) encapsulated within serum-derived EXOs for their synergistic antitumor effects. We first demonstrated that combined treatment with SD-208 and R848 can be a convincing strategy to circumvent tumor growth in vivo using serum-derived exosomes as promising carriers. Therefore, we believe this manuscript would be of great interest to the biomaterial communities especially who are studying immunotherapy.
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Bachmann J, Ehlert E, Becker M, Otto C, Radeloff K, Blunk T, Bauer-Kreisel P. Ischemia-Like Stress Conditions Stimulate Trophic Activities of Adipose-Derived Stromal/Stem Cells. Cells 2020; 9:cells9091935. [PMID: 32825678 PMCID: PMC7566001 DOI: 10.3390/cells9091935] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 07/31/2020] [Accepted: 08/19/2020] [Indexed: 01/02/2023] Open
Abstract
Adipose-derived stromal/stem cells (ASCs) have been shown to exert regenerative functions, which are mainly attributed to the secretion of trophic factors. Upon transplantation, ASCs are facing an ischemic environment characterized by oxygen and nutrient deprivation. However, current knowledge on the secretion capacity of ASCs under such conditions is limited. Thus, the present study focused on the secretory function of ASCs under glucose and oxygen deprivation as major components of ischemia. After exposure to glucose/oxygen deprivation, ASCs maintained distinct viability, but the metabolic activity was greatly reduced by glucose limitation. ASCs were able to secrete a broad panel of factors under glucose/oxygen deprivation as revealed by a cytokine antibody array. Quantification of selected factors by ELISA demonstrated that glucose deprivation in combination with hypoxia led to markedly higher secretion levels of the angiogenic and anti-apoptotic factors IL-6, VEGF, and stanniocalcin-1 as compared to the hypoxic condition alone. A conditioned medium of glucose/oxygen-deprived ASCs promoted the viability and tube formation of endothelial cells, and the proliferation and migration of fibroblasts. These findings indicate that ASCs are stimulated by ischemia-like stress conditions to secrete trophic factors and would be able to exert their beneficial function in an ischemic environment.
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Affiliation(s)
- Julia Bachmann
- Department of Trauma, Hand, Plastic and Reconstructive Surgery, University of Wuerzburg, 97080 Wuerzburg, Germany; (J.B.); (E.E.); (T.B.)
| | - Elias Ehlert
- Department of Trauma, Hand, Plastic and Reconstructive Surgery, University of Wuerzburg, 97080 Wuerzburg, Germany; (J.B.); (E.E.); (T.B.)
| | - Matthias Becker
- Institute for Medical Radiation and Cell Research, University of Wuerzburg, 97078 Wuerzburg, Germany;
| | - Christoph Otto
- Department of General, Visceral, Transplantation, Vascular and Pediatric Surgery, University of Wuerzburg, 97080 Wuerzburg, Germany;
| | - Katrin Radeloff
- Department of Otorhinolaryngology, Head and Neck Surgery, Carl von Ossietzky-University of Oldenburg, 26133 Oldenburg, Germany;
| | - Torsten Blunk
- Department of Trauma, Hand, Plastic and Reconstructive Surgery, University of Wuerzburg, 97080 Wuerzburg, Germany; (J.B.); (E.E.); (T.B.)
| | - Petra Bauer-Kreisel
- Department of Trauma, Hand, Plastic and Reconstructive Surgery, University of Wuerzburg, 97080 Wuerzburg, Germany; (J.B.); (E.E.); (T.B.)
- Correspondence: ; Tel.: +49-931-201-37115
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Harry GJ, Childers G, Giridharan S, Hernandes IL. An association between mitochondria and microglia effector function. What do we think we know? ACTA ACUST UNITED AC 2020; 7:150-165. [PMID: 32934971 DOI: 10.20517/2347-8659.2020.07] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
While resident innate immune cells of the central nervous system, the microglia, represent a cell population unique in origin, microenvironment, and longevity, they assume many properties displayed by peripheral macrophages. One prominent shared property is the ability to undergo a metabolic switch towards glycolysis and away from oxidative phosphorylation (OXPHOS) upon activation by the pro-inflammatory stimuli lipopolysaccharide. This shift serves to meet specific cellular demands and allows for cell survival, similar to the Warburg effect demonstrated in cancer cells. In contrast, normal survelliance phenotype or stimulation to a non-proinflammatory phenotype relies primarily on OXPHOS and fatty acid oxidation. Thus, mitochondria appear to function as a pivotal signaling platform linking energy metabolism and macrophage polarization upon activation. These unique shifts in cell bioenergetics in response to different stimuli are essential for proper effector responses at sites of infection, inflammation, or injury. Here we present a summary of recent developments as to how these dynamics characterized in peripheral macrophages are displayed in microglia. The new insights provided by an increased understanding of metabolic reprogramming in macrophages may allow for translation to the CNS and a better understanding of microglia heterogeneity, regulation, and function.
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Affiliation(s)
- G Jean Harry
- National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 USA
| | - Gabrielle Childers
- National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 USA.,Current affiliation: Gabrielle Childers, University of Alabama, Birmingham, AL
| | - Sahana Giridharan
- National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 USA.,Giridharan, Duke University, Durham, NC
| | - Irisyunuel Lopez Hernandes
- National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 USA
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Rabenstein M, Vay SU, Blaschke S, Walter HL, Ladwig A, Fink GR, Rueger MA, Schroeter M. Crosstalk between stressed brain cells: direct and indirect effects of ischemia and aglycemia on microglia. J Neuroinflammation 2020; 17:33. [PMID: 31980036 PMCID: PMC6982395 DOI: 10.1186/s12974-020-1697-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 01/02/2020] [Indexed: 12/17/2022] Open
Abstract
Background In cerebral ischemia, microglia have a dichotomous role in keeping the balance between pro- and anti-inflammatory mediators to avoid deleterious chronic inflammation and to leverage repair processes. Methods We examined functional and inflammatory markers in primary rat microglia in vitro after oxygen-glucose deprivation (OGD) or glucose deprivation (aglycemia). We then investigated the preconditioning effect of OGD or aglycemia upon a subsequent strong inflammatory stimulus, here lipopolysaccharides (LPS). Moreover, an “in vitro brain model” of neurons and glia, differentiated from primary rat neural stem cells, was exposed to OGD or aglycemia. Conditioned medium (CM) of this neuronal/glial co-culture was then used to condition microglia, followed by LPS as a “second hit.” Results OGD or aglycemia at sublethal doses did not significantly affect microglia function, including the expression of inflammatory markers. However, preconditioning with either OGD or aglycemia led to a decreased pro-inflammatory response to a subsequent stimulus with LPS. Interestingly, the anti-inflammatory markers IGF-1 and IL-10 were additionally reduced after such preconditioning, while expression of CD206 remained unaffected. Treatment with CM from the neuronal/glial co-culture alone did not affect the expression of inflammatory markers in microglia. In contrast, treatment with CM increased the expression of both pro- and anti-inflammatory markers in microglia upon a second hit with LPS. Interestingly, this effect could be attenuated in microglia treated with CM from neuronal/glia co-cultures preconditioned with OGD or aglycemia. Conclusions Data suggest specific and distinct microglia signatures in response to metabolic stress. While metabolic stress directly and indirectly applied to microglia did not mitigate their subsequent response to inflammation, preconditioning with metabolic stress factors such as OGD and aglycemia elicited a decreased inflammatory response to a subsequent inflammation stimulus.
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Affiliation(s)
- Monika Rabenstein
- Department of Neurology, Faculty of Medicine and University Hospital, University of Cologne, Kerpener Strasse 62, 50924, Cologne, Germany
| | - Sabine Ulrike Vay
- Department of Neurology, Faculty of Medicine and University Hospital, University of Cologne, Kerpener Strasse 62, 50924, Cologne, Germany
| | - Stefan Blaschke
- Department of Neurology, Faculty of Medicine and University Hospital, University of Cologne, Kerpener Strasse 62, 50924, Cologne, Germany.,Research Centre Juelich, Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Juelich, Germany
| | - Helene Luise Walter
- Department of Neurology, Faculty of Medicine and University Hospital, University of Cologne, Kerpener Strasse 62, 50924, Cologne, Germany
| | - Anne Ladwig
- Department of Neurology, Faculty of Medicine and University Hospital, University of Cologne, Kerpener Strasse 62, 50924, Cologne, Germany
| | - Gereon Rudolf Fink
- Department of Neurology, Faculty of Medicine and University Hospital, University of Cologne, Kerpener Strasse 62, 50924, Cologne, Germany.,Research Centre Juelich, Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Juelich, Germany
| | - Maria Adele Rueger
- Department of Neurology, Faculty of Medicine and University Hospital, University of Cologne, Kerpener Strasse 62, 50924, Cologne, Germany.,Research Centre Juelich, Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Juelich, Germany
| | - Michael Schroeter
- Department of Neurology, Faculty of Medicine and University Hospital, University of Cologne, Kerpener Strasse 62, 50924, Cologne, Germany. .,Research Centre Juelich, Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Juelich, Germany.
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Zheng Y, Houston KD. Glucose-dependent GPER1 expression modulates tamoxifen-induced IGFBP-1 accumulation. J Mol Endocrinol 2019; 63:103-112. [PMID: 31242463 PMCID: PMC6598863 DOI: 10.1530/jme-18-0253] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 05/29/2019] [Indexed: 12/22/2022]
Abstract
G protein-coupled estrogen receptor 1 (GPER1) is a seven-transmembrane receptor that mediates rapid cell signaling events stimulated by estrogens. While the role that GPER1 has in the modulation of E2-responsive tissues and cancers is well documented, the molecular mechanisms that regulate GPER1 expression are currently not well defined. The recently identified GPER1-dependent mechanism of tamoxifen action in breast cancer cells underscores the importance of identifying mechanisms that regulate GPER1 expression in this cell type. We hypothesized that GPER1 expression in breast cancer cells is sensitive to [D-glucose] and provide data showing increased GPER1 expression when cells were cultured in low [D-glucose]. To determine if the observed accumulation of GPER1 was AMP-activated protein kinase (AMPK)-dependent, small molecule stimulation or inhibition of AMPK was performed. AMPK inhibition decreased GPER1 accumulation in cells grown in low [D-glucose] while the AMPK-activating compound AICAR increased GPER1 accumulation in cells grown in high [D-glucose] media. Additionally, transfection of cells with a plasmid expressing constitutively active AMPK resulted in increased GPER1 accumulation. To determine if [D-glucose]-dependent GPER1 accumulation altered breast cancer cell response to tamoxifen, cells grown in the presence of decreasing [D-glucose] were co-treated with tamoxifen and IGFBP-1 transcription was measured. The results from these experiments reveal that D-glucose deprivation increased GPER1-mediated and tamoxifen-induced IGFBP-1 transcription suggesting that [D-glucose] may increase breast cancer cell sensitivity to tamoxifen. Taken together, these results identify a previously unknown mechanism that regulates GPER1 expression that modifies one aspect tamoxifen action in breast cancer cells.
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Affiliation(s)
- Yan Zheng
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, New Mexico, USA
| | - Kevin D Houston
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, New Mexico, USA
- Correspondence should be addressed to K D Houston:
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Churchward MA, Tchir DR, Todd KG. Microglial Function during Glucose Deprivation: Inflammatory and Neuropsychiatric Implications. Mol Neurobiol 2017; 55:1477-1487. [PMID: 28176274 PMCID: PMC5820372 DOI: 10.1007/s12035-017-0422-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2016] [Accepted: 01/25/2017] [Indexed: 12/23/2022]
Abstract
Inflammation is increasingly recognized as a contributor to the pathophysiology of neuropsychiatric disorders, including depression, anxiety disorders and autism, though the factors leading to contextually inappropriate or sustained inflammation in pathological conditions are yet to be elucidated. Microglia, as the key mediators of inflammation in the CNS, serve as likely candidates in initiating pathological inflammation and as an ideal point of therapeutic intervention. Glucose deprivation, as a component of the pathophysiology of ischemia or occurring transiently in diabetes, may serve to modify microglial function contributing to inflammatory injury. To this end, primary microglia were cultured from postnatal rat brain and subject to glucose deprivation in vitro. Microglia were characterized for their proliferation, phagocytic function and secretion of inflammatory factors, and tested for their capacity to respond to a potent inflammatory stimulus. In the absence of glucose, microglia remained capable of proliferation, phagocytosis and inflammatory activation and showed increased release of inflammatory factors after presentation of an inflammatory stimulus. Glucose-deprived microglia demonstrated increased phagocytic activity and decreased accumulation of lipids in lipid droplets over a 48-h timecourse, suggesting they may use scavenged lipids as a key alternate energy source during metabolic stress. In the present manuscript, we present novel findings that glucose deprivation may sensitize microglial release of inflammatory mediators and prime microglial functions for both survival and inflammatory roles, which may contribute to psychiatric comorbidities of ischemia, diabetes and/or metabolic disorder.
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Affiliation(s)
- Matthew A Churchward
- Neurochemical Research Unit, Department of Psychiatry, University of Alberta, 116th St and 85th Ave NW, Edmonton, AB T6G2R3, Canada
| | - Devan R Tchir
- Neurochemical Research Unit, Department of Psychiatry, University of Alberta, 116th St and 85th Ave NW, Edmonton, AB T6G2R3, Canada
| | - Kathryn G Todd
- Neurochemical Research Unit, Department of Psychiatry, University of Alberta, 116th St and 85th Ave NW, Edmonton, AB T6G2R3, Canada. .,Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB T6G 2R3, Canada.
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Abstract
Resveratrol is a natural polyphenol enriched in Polygonum cuspidatum and has been found to afford neuroprotective effects against neuroinflammation in the brain. Activated microglia can secrete various pro-inflammatory cytokines and neurotoxic mediators, which may contribute to hypoxic brain injuries. The aim of this study is to investigate the potential role of resveratrol in attenuating hypoxia-induced neurotoxicity via its anti-inflammatory actions through in vitro models of the BV-2 microglial cell line and primary microglia. We found that resveratrol significantly inhibited hypoxia-induced microglial activation and reduced subsequent release of pro-inflammatory factors. In addition, resveratrol inhibited the hypoxia-induced degradation of IκB-alpha and phosphorylation of p65 NF-κB protein. Hypoxia-induced ERK1/2 and JNK phosphorylation was also strongly inhibited by resveratrol, whereas resveratrol had no effect on hypoxia-stimulated p38 MAPK phosphorylation. Importantly, treating primary cortical neurons with conditioned medium (CM) from hypoxia-stimulated microglia induced neuronal apoptosis, which was reversed by CM co-treated with resveratrol. Taken together, resveratrol exerts neuroprotection against hypoxia-induced neurotoxicity through its anti-inflammatory effects in microglia. These effects were mediated, at least in part, by suppressing the activation of NF-ĸB, ERK and JNK MAPK signaling pathways.
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Stabilization of cellular RNA in blood during storage at room temperature: a comparison of cell-free RNA BCT(®) with K3EDTA tubes. Mol Diagn Ther 2015; 18:647-53. [PMID: 25178583 PMCID: PMC4245490 DOI: 10.1007/s40291-014-0118-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background Messenger RNA (mRNA) expression levels in blood cells are important in disease diagnosis, prognosis and biomarker discovery research. Accurate measurements of intracellular mRNA levels in blood cells depend upon several pre-analytical factors, including delays in RNA extraction from blood after phlebotomy. Dramatic changes in mRNA expression levels caused by delays in blood sample processing may render such samples unsuitable for gene expression analysis. Objectives This study was conducted to evaluate a blood collection tube, cell-free RNA-BCT® (RNA-BCT), for its ability to stabilize mRNA expression level in blood cells post-phlebotomy using indicator mRNAs in reverse transcription quantitative real-time PCR (RT-qPCR) assays. Methods Blood samples from presumed healthy donors were drawn into both RNA-BCT and K3EDTA tubes and maintained at room temperature (18–22 °C). The samples were processed to obtain white blood cells (WBCs) at days 0, 1, 2 and 3. Total cellular RNA was extracted from WBCs and mRNA concentrations were quantified by RT-qPCR for glyceraldehyde-3-phosphate dehydrogenase (GAPDH), c-fos, and p53 transcripts. Results While blood cells isolated from K3EDTA tubes showed significant changes in cellular mRNA concentrations for GAPDH, c-fos, and p53, these mRNAs concentrations were stable in blood drawn into RNA-BCT. Conclusion The reagent in the RNA-BCT device stabilizes cellular mRNA concentrations for GAPDH, c-fos and p53 for at least three days at room temperature.
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Rzemieniec J, Litwa E, Wnuk A, Lason W, Gołas A, Krzeptowski W, Kajta M. Neuroprotective action of raloxifene against hypoxia-induced damage in mouse hippocampal cells depends on ERα but not ERβ or GPR30 signalling. J Steroid Biochem Mol Biol 2015; 146:26-37. [PMID: 24846829 DOI: 10.1016/j.jsbmb.2014.05.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 05/07/2014] [Accepted: 05/11/2014] [Indexed: 01/03/2023]
Abstract
Raloxifene is the selective estrogen receptor modulator (SERM) currently used in clinical practice to activate estrogen receptors (ERs) in bone tissue and to antagonise ERs in breast and uterine cancers. Little is known, however, about mechanisms of action of raloxifene on hypoxia-induced neuronal cell damage. The aim of the present study was to investigate the neuroprotective potential of raloxifene against hypoxia-induced damage of mouse hippocampal cells in primary cultures, with a particular focus on raloxifene interactions with the classical nuclear ERs (ERα, ERβ) and the recently identified membrane ER G-protein-coupled receptor 30 (GPR30). In this study, 18 h of hypoxia increased hypoxia inducible factor 1 alpha (Hif1α) mRNA expression and induced apoptotic processes, such as loss of the mitochondrial membrane potential, activation of caspase-3 and fragmentation of cell nuclei based on Hoechst 33342 staining. These effects were accompanied by reduced ATPase and intracellular esterase activities as well as substantial lactate dehydrogenase (LDH) release from cells exposed to hypoxia. Our study demonstrated strong neuroprotective and anti-apoptotic caspase-3-independent actions of raloxifene in hippocampal cells exposed to hypoxia. Raloxifene also inhibited the hypoxia-induced decrease in Erα mRNA expression and attenuated the hypoxia-induced rise in Erβ and Gpr30 mRNA expression levels. Impact of raloxifene on hypoxia-affected Erα mRNA was mirrored by fluctuations in the protein level of the receptor as demonstrated by Western blot and immunofluorescent labelling. Raloxifene-induced changes in Erβ mRNA expression level were in parallel with ERβ immunofluorescent labeling. However, changes in Gpr30 mRNA level were not reflected by changes in the protein levels measured either by ELISA, Western blot or immunofluorescent staining at 24h post-treatment. Using specific siRNAs, we provided evidence for a key involvement of ERα, but not ERβ or GPR30 in neuroprotective action of raloxifene against hypoxia-induced cell damage. This study may have implications for the treatment or prevention of hypoxic brain injury and the administration of current or new generations of SERMs specific to ERα. This article is part of a Special Issue entitled "Sex steroids and brain disorders".
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Affiliation(s)
- J Rzemieniec
- Department of Experimental Neuroendocrinology, Institute of Pharmacology, Polish Academy of Sciences, 12 Smetna Street, 31-343 Krakow, Poland
| | - E Litwa
- Department of Experimental Neuroendocrinology, Institute of Pharmacology, Polish Academy of Sciences, 12 Smetna Street, 31-343 Krakow, Poland
| | - A Wnuk
- Department of Experimental Neuroendocrinology, Institute of Pharmacology, Polish Academy of Sciences, 12 Smetna Street, 31-343 Krakow, Poland
| | - W Lason
- Department of Experimental Neuroendocrinology, Institute of Pharmacology, Polish Academy of Sciences, 12 Smetna Street, 31-343 Krakow, Poland
| | - A Gołas
- Department of Genetics and Evolution, Institute of Zoology, Jagiellonian University, 9 Gronostajowa Street, 30-387 Krakow, Poland
| | - W Krzeptowski
- Department of Cell Biology and Imaging, Confocal Microscopy Laboratory, Institute of Zoology, Jagiellonian University, 9 Gronostajowa Street, 30-387 Krakow, Poland
| | - M Kajta
- Department of Experimental Neuroendocrinology, Institute of Pharmacology, Polish Academy of Sciences, 12 Smetna Street, 31-343 Krakow, Poland.
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Mishra KP, Chanda S, Singh SB, Ganju L. A comparative immunological analysis of CoCl2 treated cells with in vitro hypoxic exposure. Biometals 2014; 28:175-85. [PMID: 25511110 DOI: 10.1007/s10534-014-9813-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 12/10/2014] [Indexed: 01/23/2023]
Abstract
The hypoxic preconditioning of mammalian cells has been shown to have beneficial effects against hypoxic injuries. However, very little information is available on the comparative analysis of immunological responses to hypoxic and hypoxia mimetic exposure. Therefore, in the present study, mouse peritoneal macrophages and splenocytes were subjected to hypoxia exposure (0.5 % O2) and hypoxia mimetic Cobalt chloride (CoCl2) treatment to evaluate their effect on immune response and delineate the underlying signaling mechanisms. The results obtained indicated that super oxide generation increased while TLR4 expression and cell surface markers like CD25, CD40 and CD69 were suppressed in both the treatments as compared to normoxia. Cobalt chloride treatment increased NF-κB expression, nitric oxide (NO) and iNOS expression, cytokines TNF-α and IL-6 as compared to hypoxia exposure. Our study showed that CoCl2 stabilizes HIF-1α to create hypoxia like conditions but it mainly influences the inflammatory response via NF-κB signaling pathway by skewing the production of proinflammatory molecules like TNF-α, IL-6 and NO.
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Zhang Q, Yuan L, Liu D, Wang J, Wang S, Zhang Q, Gong Y, Liu H, Hao A, Wang Z. Hydrogen sulfide attenuates hypoxia-induced neurotoxicity through inhibiting microglial activation. Pharmacol Res 2014; 84:32-44. [DOI: 10.1016/j.phrs.2014.04.009] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Revised: 03/28/2014] [Accepted: 04/17/2014] [Indexed: 10/25/2022]
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