82 results on '"Lykke-Hartmann K"'
Search Results
2. Transcripts encoding free radical scavengers in human granulosa cells from primordial and primary ovarian follicles
- Author
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Ernst, E. H. and Lykke-Hartmann, K.
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- 2018
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3. Cyclin-dependent kinase 6 (CDK6) as a potent regulator of the ovarian primordial-to-primary follicle transition
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Ataei-Nazari, S., primary, Amoushahi, M., additional, Madsen, JF., additional, Jensen, J., additional, Heuck, A., additional, Mohammadi-Sangcheshmeh, A., additional, and Lykke-Hartmann, K., additional
- Published
- 2022
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4. The transcriptomes of human oocytes isolated from primordial or pre-ovulatory follicles reveal interesting differences and identify novel genes in reproduction: O-011
- Author
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Groendahl, M., Vikeså, J., Borup, R., Andersen, C. Yding, Ernst, E., and Lykke-Hartmann, K.
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- 2012
5. Expression of proposed implantation marker genes CDX2 and HOXB7 in the blastocyst does not distinguish viable from non-viable human embryos: O-005
- Author
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Kirkegaard, K., Hindkjaer, J., Ingerslev, H. J., and Lykke-Hartmann, K.
- Published
- 2012
6. Global gene analysis of oocytes from early stages in human folliculogenesis shows high expression of novel genes in reproduction
- Author
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Markholt, S., Grøndahl, M.L., Ernst, E.H., Andersen, C. Yding, Ernst, E., and Lykke-Hartmann, K.
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- 2012
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7. Distinct expression patterns of TLR transcripts in human oocytes and granulosa cells from primordial and primary follicles
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Ernst, E.H., primary, Amoushahi, M., additional, Sørensen, A.S., additional, Kragstrup, T.W., additional, Ernst, E., additional, and Lykke-Hartmann, K., additional
- Published
- 2020
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8. Increased susceptibility to cortical spreading depression and epileptiform activity in a mouse model for FHM2
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Kros, Lieke, Lykke-Hartmann, K, Khodakhah, K, Kros, Lieke, Lykke-Hartmann, K, and Khodakhah, K
- Published
- 2018
9. Granulosa cells from human primordial and primary follicles show differential global gene expression profiles
- Author
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Ernst, E H, primary, Franks, S, additional, Hardy, K, additional, Villesen, P, additional, and Lykke-Hartmann, K, additional
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- 2018
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10. Dormancy and activation of human oocytes from primordial and primary follicles: molecular clues to oocyte regulation
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Ernst, E.H., primary, Grøndahl, M.L., additional, Grund, S., additional, Hardy, K., additional, Heuck, A., additional, Sunde, L., additional, Franks, S., additional, Andersen, C.Y., additional, Villesen, P., additional, and Lykke-Hartmann, K., additional
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- 2017
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11. Distinct neurological disorders with ATP1A3 mutations
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Heinzen, El, Arzimanoglou, A, Brashear, A, Clapcote, Sj, Gurrieri, F, Goldstein, Db, Jóhannesson, Sh, Mikati, Ma, Neville, B, Nicole, S, Ozelius, Lj, Poulsen, H, Schyns, T, Sweadner, Kj, van den Maagdenberg, A, Vilsen, B, ATP1A3 Working Group, Ashcroft, Fm, Salem, W, Brockmann, K, Campistol, J, Capuano, A, Carrilho, I, Casaer, P, DE GRANDIS, Elisa, de Vries, B, Di Michele, M, Dion, C, Doummar, D, Einholm, Ap, Fons, C, Franchini, F, Friedrich, T, Freson, K, Gadsby, Dc, Giannotta, M, Goubau, C, Granata, T, Hirose, S, Hitomi, Y, Holm, R, Ikeda, K, Ishii, A, Khodakhah, K, King, Md, Kirshenbaum, Gs, Kockhans, A, Koenderink, Jb, Lesca, G, Lykke Hartmann, K, Maschke, U, Merida, Mr, Müller, R, Neri, G, Nielsen, Hn, Nissen, P, O'Brien, T, Panagiotakaki, E, Parowicz, M, Poncelin, D, Reyna, Sp, Roder, Jc, Rosewich, H, Sasaki, M, Schack, Vr, Schyns, P, Stagnaro, M, Swoboda, Kj, Tiziano, Df, Toustrup Jensen MS, Vilamala, A, Wuchich, J. T., UCL - (SLuc) Service de pédiatrie générale, and UCL - SSS/IREC/PEDI - Pôle de Pédiatrie
- Subjects
Models, Molecular ,Alternating Hemiplegia Childhood ,lnfectious Diseases and Global Health Radboud Institute for Molecular Life Sciences [Radboudumc 4] ,Hemiplegia ,Disease ,Biology ,Settore MED/03 - GENETICA MEDICA ,medicine.disease_cause ,Article ,ATP1A3 ,medicine ,Animals ,Humans ,Genetic Predisposition to Disease ,Gene ,Sequence (medicine) ,Genetics ,Mutation ,Mechanism (biology) ,Alternating hemiplegia of childhood ,Parkinson Disease ,ATP1A3, Alternating Hemiplegia Childhood ,medicine.disease ,Databases, Bibliographic ,Neurology (clinical) ,α3 subunit ,Sodium-Potassium-Exchanging ATPase ,Nervous System Diseases - Abstract
Item does not contain fulltext Genetic research has shown that mutations that modify the protein-coding sequence of ATP1A3, the gene encoding the alpha3 subunit of Na(+)/K(+)-ATPase, cause both rapid-onset dystonia parkinsonism and alternating hemiplegia of childhood. These discoveries link two clinically distinct neurological diseases to the same gene, however, ATP1A3 mutations are, with one exception, disease-specific. Although the exact mechanism of how these mutations lead to disease is still unknown, much knowledge has been gained about functional consequences of ATP1A3 mutations using a range of in-vitro and animal model systems, and the role of Na(+)/K(+)-ATPases in the brain. Researchers and clinicians are attempting to further characterise neurological manifestations associated with mutations in ATP1A3, and to build on the existing molecular knowledge to understand how specific mutations can lead to different diseases.
- Published
- 2014
12. The dormant and the fully competent oocyte: comparing the transcriptome of human oocytes from primordial follicles and in metaphase II
- Author
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Grondahl, M. L., primary, Borup, R., additional, Vikesa, J., additional, Ernst, E., additional, Andersen, C. Y., additional, and Lykke-Hartmann, K., additional
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- 2013
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13. SESSION 03: FEMALE INFERTILITY 1
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Sunkara, S. K., primary, Seshadri, S., additional, El-Toukhy, T., additional, Khalaf, Y., additional, Schuh-Huerta, S. M., additional, Johnson, N. A., additional, Rosen, M. P., additional, Sternfeld, B., additional, Cedars, M. I., additional, Reijo Pera, R. A., additional, Groendahl, M., additional, Vikesa, J., additional, Borup, R., additional, Yding Andersen, C., additional, Ernst, E., additional, Lykke-Hartmann, K., additional, Liu, W., additional, Zhong, Y., additional, Zou, X., additional, Xi, W. Y., additional, Gong, F., additional, Fan, L. Q., additional, Lu, G. X., additional, Lehert, P., additional, Rongieres, C., additional, Pirrello, O., additional, Ohl, J., additional, Bettahar, K., additional, Nisand, I., additional, Smit, J. G., additional, Kasius, J. C., additional, Eijkemans, M. J. C., additional, Campo, R., additional, and Broekmans, F. J. M., additional
- Published
- 2012
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14. SESSION 02: EMBRYOLOGY - BIOMARKERS
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Zaninovic, N., primary, Rosenwaks, Z., additional, Iager, A. E., additional, Kocabas, A. M., additional, Otu, H. H., additional, Ruppel, P., additional, Langerveld, A., additional, Schnarr, P., additional, Suarez, M., additional, Jarrett, J. C., additional, Conaghan, J., additional, Rosa, G. J. M., additional, Fernandez, E., additional, Rawlins, R. G., additional, Cibelli, J. B., additional, Crosby, J., additional, Kirkegaard, K., additional, Hindkjaer, J., additional, Ingerslev, H. J., additional, Lykke-Hartmann, K., additional, Himaya, E., additional, Jamal, W., additional, Phillips, S., additional, Delrieu, D., additional, Hamamah, S., additional, Kadoch, I. J., additional, Cortezzi, S. S., additional, Cabral, E. C., additional, Ferreira, C. R., additional, Trevisan, M. G., additional, Figueira, R. C. S., additional, Eberlin, M. N., additional, Iaconelli, A., additional, Borges, E., additional, Chimote, N. M., additional, Chimote, N. N., additional, Nath, N. M., additional, Chimote, M. N., additional, and Mehta, B. N., additional
- Published
- 2012
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15. The α2 Na+/K+-ATPase isoform mediates LPS-induced neuroinflammation.
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Leite, J. A., Isaksen, T. J., Heuck, A., Scavone, C., and Lykke-Hartmann, K.
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ADENOSINE triphosphatase ,LIPOPOLYSACCHARIDES ,IMMUNE response ,TOLL-like receptors ,TARGETED drug delivery ,ASTROCYTES - Abstract
Na
+ /K+ -ATPase is a transmembrane ion pump that is essential for the maintenance of ion gradients and regulation of multiple cellular functions. Na+ /K+ -ATPase has been associated with nuclear factor kappa B (NFκB) signalling, a signal associated with lipopolysaccharides (LPSs)-induced immune response in connection with activated Toll-like receptor 4 (TLR4) signalling. However, the contribution of Na+ /K+ -ATPase to regulating inflammatory responses remains elusive. We report that mice haploinsufficient for the astrocyte-enriched α2 Na+ /K+ -ATPase isoform (α2 +/G301R mice) have a reduced proinflammatory response to LPS, accompanied by a reduced hypothermic reaction compared to wild type litter mates. Following intraperitoneal injection of LPS, gene expressions of Tnf-α, Il-1β, and Il-6 was reduced in the hypothalamus and hippocampus from α2 +/G301R mice compared to α2 +/+ littermates. The α2 +/G301R mice experienced increased expression of the gene encoding an antioxidant enzyme, NRF2, in hippocampal astrocytes. Our findings indicate that α2 Na+ /K+ -ATPase haploinsufficiency negatively modulates LPS-induced immune responses, highlighting a rational pharmacological target for reducing LPS-induced inflammation. [ABSTRACT FROM AUTHOR]- Published
- 2020
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16. Phenotype Distinctions in Mice Deficient in the Neuron-Specific α3 Subunit of Na,K-ATPase: Atp1a 3 tm1Ling/+ and Atp1a3 +/D801Y .
- Author
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Liu YB, Arystarkhova E, Sacino AN, Szabari MV, Lutz CM, Terrey M, Morsci NS, Jakobs TC, Lykke-Hartmann K, Brashear A, Napoli E, and Sweadner KJ
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- Animals, Mice, Female, Male, Disease Models, Animal, Hemiplegia genetics, Mice, Inbred C57BL, Neurons metabolism, Mice, Transgenic, Sodium-Potassium-Exchanging ATPase genetics, Sodium-Potassium-Exchanging ATPase metabolism, Phenotype, Dystonic Disorders genetics
- Abstract
ATP1A3 is a Na,K-ATPase gene expressed specifically in neurons in the brain. Human mutations are dominant and produce an unusually wide spectrum of neurological phenotypes, most notably rapid-onset dystonia parkinsonism (RDP) and alternating hemiplegia of childhood (AHC). Here we compared heterozygotes of two mouse lines, a line with little or no expression ( Atp1a 3
tm1Ling/+ ) and a knock-in expressing p.Asp801Tyr (D801Y, Atp1a3+/D801Y ). Both mouse lines had normal lifespans, but Atp1a3+/D801Y had mild perinatal mortality contrasting with D801N mice ( Atp1a3+/D801N ), which had high mortality. The phenotypes of Atp1a 3tm1Ling/+ and Atp1a3+/D801Y were different, and testing of each strain was tailored to its symptom range. Atp1a 3tm1Ling/+ mice displayed little at baseline, but repeated ethanol intoxication produced hyperkinetic motor abnormalities not seen in littermate controls. Atp1a3+/D801Y mice displayed robust phenotypes: hyperactivity, diminished posture consistent with hypotonia, and deficiencies in beam walk and wire hang tests. Symptoms also included qualitative motor abnormalities that are not well quantified by conventional tests. Paradoxically, Atp1a3+/D801Y showed sustained better performance than wild type on the accelerating rotarod. Atp1a3+/D801Y mice were overactive in forced swimming and afterward had intense shivering, transient dystonic postures, and delayed recovery. Remarkably, Atp1a3+/D801Y mice were refractory to ketamine anesthesia, which elicited hyperactivity and dyskinesia even at higher dose. Neither mouse line exhibited fixed dystonia (typical of RDP patients), spontaneous paroxysmal weakness (typical of AHC patients), or seizures but had consistent, measurable neurological abnormalities. A gradient of variation supports the importance of studying multiple Atp1a3 mutations in animal models to understand the roles of this gene in human disease., Competing Interests: The authors declare no competing financial interests., (Copyright © 2024 Liu et al.)- Published
- 2024
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17. Dorsomorphin inhibits AMPK, upregulates Wnt and Foxo genes and promotes the activation of dormant follicles.
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Madsen JF, Ernst EH, Amoushahi M, Dueholm M, Ernst E, and Lykke-Hartmann K
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- Animals, Female, Mice, Humans, Up-Regulation drug effects, Forkhead Transcription Factors metabolism, Forkhead Transcription Factors genetics, Wnt Proteins metabolism, Wnt Proteins genetics, beta Catenin metabolism, beta Catenin genetics, Phosphorylation drug effects, Mice, Inbred C57BL, Metformin pharmacology, Wnt Signaling Pathway drug effects, Ovarian Follicle drug effects, Ovarian Follicle metabolism, AMP-Activated Protein Kinases metabolism, AMP-Activated Protein Kinases genetics, Pyrimidines pharmacology, Pyrazoles pharmacology
- Abstract
AMPK is a well-known energy sensor regulating cellular metabolism. Metabolic disorders such as obesity and diabetes are considered detrimental factors that reduce fecundity. Here, we show that pharmacologically induced in vitro activation (by metformin) or inhibition (by dorsomorphin) of the AMPK pathway inhibits or promotes activation of ovarian primordial follicles in cultured murine ovaries and human ovarian cortical chips. In mice, activation of primordial follicles in dorsomorphin in vitro-treated ovaries reduces AMPK activation and upregulates Wnt and FOXO genes, which, interestingly, is associated with decreased phosphorylation of β-catenin. The dorsomorphin-treated ovaries remain of high quality, with no detectable difference in reactive oxygen species production, apoptosis or mitochondrial cytochrome c oxidase activity, suggesting safe activation. Subsequent maturation of in vitro-treated follicles, using a 3D alginate cell culture system, results in mature metaphase eggs with protruding polar bodies. These findings demonstrate that the AMPK pathway can safely regulate primordial follicles by modulating Wnt and FOXO genes, and reduce β-catenin phosphorylation., (© 2024. The Author(s).)
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- 2024
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18. Inhibition of phosphodiesterase PDE8B reduces activation of primordial follicles in mouse ovaries.
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Madsen JF, Amoushahi M, Choi CP, Bundgaard S, Heuck A, and Lykke-Hartmann K
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- Animals, Female, Humans, Mice, 3',5'-Cyclic-AMP Phosphodiesterases antagonists & inhibitors, 3',5'-Cyclic-AMP Phosphodiesterases metabolism, Ketotifen metabolism, Ketotifen pharmacology, Oocytes, Ovarian Follicle metabolism, Steroids metabolism, Ovary metabolism, Phosphoric Diester Hydrolases genetics, Phosphoric Diester Hydrolases metabolism
- Abstract
In the ovaries, cyclic adenosine 3',5'-monophosphate (cAMP) is a second messenger supporting the generation of steroids. Phosphodiesterases (PDEs) are regulators of intracellular cAMP, and therefore, potential regulators of ovarian function. Interestingly, the family of PDE genes are differentially expressed in human oocytes and granulosa cells from primordial and primary follicles, suggesting diverse roles. In this study, we addressed the functions of PDE3B and PDE8B in primordial follicle regulation using inhibitors of PDE3B and PDE8B in murine ovary primary in vitro cultures. Inhibition of PDE8B in ovarian cultures prevented primordial follicle activation, while inhibition of PDE3B had no effect on follicle distribution in the ovary, under the tested conditions. As cAMP levels may increase steroid levels, we assessed the protein levels of the steroidogenic acute regulatory protein (StAR) and aromatase enzymes, and found that inhibition of PDE3B reduced StAR protein levels, whereas inhibition of PDE8 did not alter StAR expression in our murine ovary culture system conditions. Our results showed that ketotifen-induced inhibition of PDE8B can decrease primordial follicle activation, whereas we observed no effect of follicle distribution, when PDE3B was inhibited. Expression of the StaR enzyme was not altered when PDE8B was inhibited, which might reflect not sufficient inhibition by ketotifen to induce StAR alterations, or redundant mechanisms., (© 2023 The Authors. Molecular Reproduction and Development published by Wiley Periodicals LLC.)
- Published
- 2023
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19. Migraine-Associated Mutation in the Na,K-ATPase Leads to Disturbances in Cardiac Metabolism and Reduced Cardiac Function.
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Staehr C, Rohde PD, Krarup NT, Ringgaard S, Laustsen C, Johnsen J, Nielsen R, Beck HC, Morth JP, Lykke-Hartmann K, Jespersen NR, Abramochkin D, Nyegaard M, Bøtker HE, Aalkjaer C, and Matchkov V
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- Animals, Heterozygote, Mice, Mutation, Myocardium metabolism, Heart physiopathology, Migraine Disorders, Migraine with Aura metabolism, Sodium-Potassium-Exchanging ATPase genetics
- Abstract
Background Mutations in ATP1A2 gene encoding the Na,K-ATPase α
2 isoform are associated with familial hemiplegic migraine type 2. Migraine with aura is a known risk factor for heart disease. The Na,K-ATPase is important for cardiac function, but its role for heart disease remains unknown. We hypothesized that ATP1A2 is a susceptibility gene for heart disease and aimed to assess the underlying disease mechanism. Methods and Results Mice heterozygous for the familial hemiplegic migraine type 2-associated G301R mutation in the Atp1a2 gene (α2 mice) and matching wild-type controls were compared. Reduced expression of the Na,K-ATPase α+/G301R mice) and matching wild-type controls were compared. Reduced expression of the Na,K-ATPase α2 isoform and increased expression of the α1 isoform were observed in hearts from α2 +/G301R mice were similar to wild-type mice. Amplified Na,K-ATPase-dependent Src kinase/Ras/Erk1/2 (p44/42 mitogen-activated protein kinase) signaling was observed in hearts from 8-month-old α2 +/G301R mice (cardiac magnetic resonance imaging), and this was associated with reduced nocturnal blood pressure (radiotelemetry). Cardiac function and blood pressure of 3-month-old α2 mutation leads to disturbed cardiac metabolism and reduced cardiac function mediated via Na,K-ATPase-dependent reactive oxygen species signaling through the Src/Ras/Erk1/2 pathway.+/G301R mice were similar to wild-type mice. Amplified Na,K-ATPase-dependent Src kinase/Ras/Erk1/2 (p44/42 mitogen-activated protein kinase) signaling was observed in hearts from 8-month-old α2 +/G301R mice, and this was associated with mitochondrial uncoupling (respirometry), increased oxidative stress (malondialdehyde measurements), and a heart failure-associated metabolic shift (hyperpolarized magnetic resonance). Mitochondrial membrane potential (5,5´,6,6´-tetrachloro-1,1´,3,3´-tetraethylbenzimidazolocarbocyanine iodide dye assay) and mitochondrial ultrastructure (transmission electron microscopy) were similar between the groups. Proteomics of heart tissue further suggested amplified Src/Ras/Erk1/2 signaling and increased oxidative stress and provided the molecular basis for systolic dysfunction in 8-month-old α2 +/G301R mice. Conclusions Our findings suggest that ATP1A2 mutation leads to disturbed cardiac metabolism and reduced cardiac function mediated via Na,K-ATPase-dependent reactive oxygen species signaling through the Src/Ras/Erk1/2 pathway.- Published
- 2022
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20. Editorial: Involvement of Autophagy in Determining the Developmental Fate of Ovarian Follicles.
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Zhang JQ, Lykke-Hartmann K, and Shen M
- Abstract
Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
- Published
- 2021
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21. Distinct Signaling Pathways Distinguish in vivo From in vitro Growth in Murine Ovarian Follicle Activation and Maturation.
- Author
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Amoushahi M and Lykke-Hartmann K
- Abstract
Women with cancer and low ovarian reserves face serious challenges in infertility treatment. Ovarian tissue cryopreservation is currently used for such patients to preserve fertility. One major challenge is the activation of dormant ovarian follicles, which is hampered by our limited biological understanding of molecular determinants that activate dormant follicles and help maintain healthy follicles during growth. Here, we investigated the transcriptomes of oocytes isolated from dormant (primordial) and activated (primary) follicles under in vivo and in vitro conditions. We compared the biological relevance of the initial molecular markers of mature metaphase II (MII) oocytes developed in vivo or in vitro . The expression levels of genes involved in the cell cycle, signal transduction, and Wnt signaling were highly enriched in oocytes from primary follicles and MII oocytes. Interestingly, we detected strong downregulation of the expression of genes involved in mitochondrial and reactive oxygen species (ROS) production in oocytes from primordial follicles, in contrast to oocytes from primary follicles and MII oocytes. Our results showed a dynamic pattern in mitochondrial and ROS production-related genes, emphasizing their important role(s) in primordial follicle activation and oocyte maturation. The transcriptome of MII oocytes showed a major divergence from that of oocytes of primordial and primary follicles., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Amoushahi and Lykke-Hartmann.)
- Published
- 2021
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22. Abnormal neurovascular coupling as a cause of excess cerebral vasodilation in familial migraine.
- Author
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Staehr C, Rajanathan R, Postnov DD, Hangaard L, Bouzinova EV, Lykke-Hartmann K, Bach FW, Sandow SL, Aalkjaer C, and Matchkov VV
- Subjects
- Animals, Disease Models, Animal, Endothelial Cells metabolism, Female, Hyperemia enzymology, Hyperemia physiopathology, Male, Mice, Transgenic, Middle Cerebral Artery enzymology, Migraine with Aura enzymology, Migraine with Aura genetics, Mutation, Potassium Channels, Inwardly Rectifying metabolism, Sodium-Potassium-Exchanging ATPase genetics, Cerebrovascular Circulation, Middle Cerebral Artery physiopathology, Migraine with Aura physiopathology, Neurovascular Coupling, Sodium-Potassium-Exchanging ATPase metabolism, Vasodilation
- Abstract
Aims: Acute migraine attack in familial hemiplegic migraine type 2 (FHM2) patients is characterized by sequential hypo- and hyperperfusion. FHM2 is associated with mutations in the Na, K-ATPase α2 isoform. Heterozygous mice bearing one of these mutations (α2+/G301R mice) were shown to have elevated cerebrovascular tone and, thus, hypoperfusion that might lead to elevated concentrations of local metabolites. We hypothesize that these α2+/G301R mice also have increased cerebrovascular hyperaemic responses to these local metabolites leading to hyperperfusion in the affected part of the brain., Methods and Results: Neurovascular coupling was compared in α2+/G301R and matching wild-type (WT) mice using Laser Speckle Contrast Imaging. In brain slices, parenchymal arteriole diameter and intracellular calcium changes in neuronal tissue, astrocytic endfeet, and smooth muscle cells in response to neuronal excitation were assessed. Wall tension and smooth muscle membrane potential were measured in isolated middle cerebral arteries. Quantitative polymerase chain reaction, western blot, and immunohistochemistry were used to assess the molecular background underlying the functional changes. Whisker stimulation induced larger increase in blood perfusion, i.e. hyperaemic response, of the somatosensory cortex of α2+/G301R than WT mice. Neuronal excitation was associated with larger parenchymal arteriole dilation in brain slices from α2+/G301R than WT mice. These hyperaemic responses in vivo and ex vivo were inhibited by BaCl2, suggesting involvement of inward-rectifying K+ channels (Kir). Relaxation to elevated bath K+ was larger in arteries from α2+/G301R compared to WT mice. This difference was endothelium-dependent. Endothelial Kir2.1 channel expression was higher in arteries from α2+/G301R mice. No sex difference in functional responses and Kir2.1 expression was found., Conclusion: This study suggests that an abnormally high cerebrovascular hyperaemic response in α2+/G301R mice is a result of increased endothelial Kir2.1 channel expression. This may be initiated by vasospasm-induced accumulation of local metabolites and underlie the hyperperfusion seen in FHM2 patients during migraine attack., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2019. For permissions, please email: journals.permissions@oup.com.)
- Published
- 2020
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23. Maternally contributed Nlrp9b expressed in human and mouse ovarian follicles contributes to early murine preimplantation development.
- Author
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Amoushahi M, Steffensen LL, Galieva A, Agger J, Heuck A, Siupka P, Ernst E, Nielsen MS, Sunde L, and Lykke-Hartmann K
- Subjects
- Animals, Blastomeres cytology, Blastomeres metabolism, Cytoplasm genetics, Embryo, Mammalian, Female, Gene Expression Regulation, Developmental genetics, Humans, Mice, Ovarian Follicle metabolism, Sequence Analysis, RNA, Zygote growth & development, Embryonic Development genetics, Oocytes growth & development, Ovarian Follicle growth & development, Receptors, G-Protein-Coupled genetics
- Abstract
Purpose: The aim of the study is to investigate presence and role of the gene encoding the maternally contributed nucleotide-binding oligomerization domain (NOD)-like receptors with a pyrin domain (PYD)-containing protein 9 (NLRP9) in human and mouse ovaries, respectively, and in preimplantation mouse embryo development by knocking down Nlrp9b., Methods: Expression levels of NLRP9 mRNA in human follicles were extracted from RNA sequencing data from previous studies. In this study, we performed a qPCR analysis of Nlpr9b mRNA in mouse oocytes and found it present. Intracellular ovarian distribution of NLRP9B protein was accomplished using immunohistochemistry. The distribution of NLRP9B was explored using a reporter gene approach, fusing NLRP9B to green fluorescent protein and microinjection of in vitro-generated mRNA. Nlrp9b mRNA function was knocked down by microinjection of short interference (si) RNA targeting Nlrp9b, into mouse pronuclear zygotes. Knockdown of the Nlrp9b mRNA transcript was confirmed by qPCR., Result: We found that the human NLRP9 gene and its corresponding protein are highly expressed in human primordial and primary follicles. The NLRP9B protein is localized to the cytoplasm in the blastomeres of a 2-cell embryo in mice. SiRNA-mediated knockdown of Nlrp9b caused rapid elimination of endogenous Nlrp9b mRNA and premature embryo arrest at the 2- to 4-cell stages compared with that of the siRNA-scrambled control group., Conclusions: These results suggest that mouse Nlrp9b, as a maternal effect gene, could contribute to mouse preimplantation embryo development. It remains to investigate whether NLRP9 have a crucial role in human preimplantation embryo and infertility.
- Published
- 2020
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24. Reduced hepatic metallothionein expression in first trimester fetuses in response to intrauterine smoking exposure: a consequence of low maternal zinc levels?
- Author
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Bilde K, Olesen RH, Ernst EH, Mamsen LS, Amoushahi M, Lykke-Hartmann K, Ernst E, and Larsen A
- Subjects
- Abortion, Induced, Cross-Sectional Studies, Denmark, Dietary Supplements, Female, Gene Expression Profiling, Gene Expression Regulation, Developmental, Humans, Liver embryology, Placenta metabolism, Pregnancy, Pregnancy Trimester, First, Liver enzymology, Maternal Exposure, Metallothionein metabolism, Smoking adverse effects, Zinc blood
- Abstract
Study Question: Does maternal smoking in early pregnancy affect metallothionein 1 and 2 (MT1 and MT2) mRNA and protein expression in first trimester placenta or embryonic/fetal liver?, Summary Answer: In the first trimester, MT protein expression is seen only in liver, where smoking is associated with a significantly reduced expression., What Is Known Already: Zinc homeostasis is altered by smoking. Smoking induces MT in the blood of smokers properly as a result of the cadmium binding capacities of MT. In term placenta MT is present and smoking induces gene and protein expression (MT2 in particular), but the MT presence and response to smoking have never been examined in first trimester placenta or embryonic/fetal tissues., Study Design, Size, Duration: Cross sectional study where the presence of MT mRNA and protein was examined at the time of the abortion. The material was collected with informed consent after surgical intervention and frozen immediately. For protein expression analysis, liver tissue originating from smoking exposed n = 10 and unexposed n = 12 pregnancies was used. For mRNA expression analyses, placental tissue originating from smokers n = 19 and non-smokers n = 23 and fetal liver tissue from smoking exposed n = 16 and smoking unexposed pregnancies n = 13, respectively, were used., Participants/materials, Setting, Methods: Tissues were obtained from women who voluntarily and legally chose to terminate their pregnancy between gestational week 6 and 12. Western blot was used to determine the protein expression of MT, and real-time PCR was used to quantify the mRNA expression of MT2A and eight MT1 genes alongside the expression of key placental zinc transporters: zinc transporter protein-1 (ZNT1), Zrt-, Irt-related protein-8 and -14 (ZIP8 and ZIP14)., Main Results and the Role of Chance: A significant reduction in the protein expression of MT1/2 in liver tissue (P = 0.023) was found by western blot using antibodies detecting both MT forms. Overall, a similar tendency was observed on the mRNA level although not statistically significant. Protein expression was not present in placenta, but the mRNA regulation suggested a down regulation of MT as well. A suggested mechanism based on the known role of MT in zinc homeostasis could be that the findings reflect reduced levels of easily accessible zinc in the blood of pregnant smokers and hence a reduced MT response in smoking exposed fetal/embryonic tissues., Limitations and Reasons for Caution: Smoking was based on self-reports; however, our previous studies have shown high consistency regarding cotinine residues and smoking status. Passive smoking could interfere but was found mainly among smokers. The number of fetuses was limited, and other factors such as medication and alcohol might affect the findings. Information on alcohol was not consistently obtained, and we cannot exclude that it was more readily obtained from non-users. In the study, alcohol consumption was reported by a limited number (less than 1 out of 5) of women but with more smokers consuming alcohol. However, the alcohol consumption reported was typically limited to one or few times low doses. The interaction between alcohol and smoking is discussed in the paper. Notably we would have liked to measure zinc status to test our hypothesis, but maternal blood samples were not available., Wider Implications of the Findings: Zinc deficiency-in particular severe zinc deficiency-can affect pregnancy outcome and growth. Our findings indicate that zinc homeostasis is also affected in early pregnancy of smokers, and we know from pilot studies that even among women who want to keep their babies, the zinc status is low. Our findings support that zinc supplements should be considered in particular to women who smoke., Study Funding/competing Interest(s): We thank the Department of Biomedicine for providing laboratory facilities and laboratory technicians and the Lundbeck Foundation and Læge Sofus Carl Emil Friis og Hustru Olga Doris Friis Legat for financial support. The authors have no competing interests to declare., Trial Registration Number: N/A., (© The Author(s) 2019. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.)
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- 2019
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25. Smooth muscle Ca 2+ sensitization causes hypercontractility of middle cerebral arteries in mice bearing the familial hemiplegic migraine type 2 associated mutation.
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Staehr C, Hangaard L, Bouzinova EV, Kim S, Rajanathan R, Boegh Jessen P, Luque N, Xie Z, Lykke-Hartmann K, Sandow SL, Aalkjaer C, and Matchkov VV
- Subjects
- Animals, Calcium metabolism, Mice, Middle Cerebral Artery metabolism, Migraine with Aura genetics, Muscle, Smooth, Vascular metabolism, Point Mutation, Cerebrovascular Circulation genetics, Migraine with Aura metabolism, Muscle Contraction genetics, Sodium-Potassium-Exchanging ATPase genetics, Vasoconstriction genetics
- Abstract
Familial hemiplegic migraine type 2 (FHM2) is associated with inherited point-mutations in the Na,K-ATPase α2 isoform, including G301R mutation. We hypothesized that this mutation affects specific aspects of vascular function, and thus compared cerebral and systemic arteries from heterozygote mice bearing the G301R mutation (Atp1a2
+/-G301R ) with wild type (WT). Middle cerebral (MCA) and mesenteric small artery (MSA) function was compared in an isometric myograph. Cerebral blood flow was assessed with Laser speckle analysis. Intracellular Ca2+ and membrane potential were measured simultaneously. Protein expression was semi-quantified by immunohistochemistry. Protein phosphorylation was analysed by Western blot. MSA from Atp1a2+/-G301R and WT showed similar contractile responses. The Atp1a2+/-G301R MCA constricted stronger to U46619, endothelin and potassium compared to WT. This was associated with an increased depolarization, although the Ca2+ change was smaller than in WT. The enhanced constriction of Atp1a2+/-G301R MCA was associated with increased cSrc activation, stronger sensitization to [Ca2+ ]i and increased MYPT1 phosphorylation. These differences were abolished by cSrc inhibition. Atp1a2+/-G301R mice had reduced resting blood flow through MCA in comparison with WT mice . FHM2-associated mutation leads to elevated contractility of MCA due to sensitization of the contractile machinery to Ca2+ , which is mediated via Na,K-ATPase/Src-kinase/MYPT1 signalling.- Published
- 2019
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26. The pivotal roles of the NOD-like receptors with a PYD domain, NLRPs, in oocytes and early embryo development†.
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Amoushahi M, Sunde L, and Lykke-Hartmann K
- Subjects
- Adaptor Proteins, Signal Transducing genetics, Animals, Apoptosis Regulatory Proteins genetics, Apoptosis Regulatory Proteins metabolism, Humans, Protein Domains, Adaptor Proteins, Signal Transducing metabolism, Embryonic Development physiology, Gene Expression Regulation, Developmental physiology
- Abstract
Nucleotide-binding oligomerization domain (NOD)-like receptors with a pyrin domain (PYD), NLRPs, are pattern recognition receptors, well recognized for their important roles in innate immunity and apoptosis. However, several NLRPs have received attention for their new, specialized roles as maternally contributed genes important in reproduction and embryo development. Several NLRPs have been shown to be specifically expressed in oocytes and preimplantation embryos. Interestingly, and in line with divergent functions, NLRP genes reveal a complex evolutionary divergence. The most pronounced difference is the human-specific NLRP7 gene, not identified in rodents. However, mouse models have been extensively used to study maternally contributed NLRPs. The NLRP2 and NLRP5 proteins are components of the subcortical maternal complex (SCMC), which was recently identified as essential for mouse preimplantation development. The SCMC integrates multiple proteins, including KHDC3L, NLRP5, TLE6, OOEP, NLRP2, and PADI6. The NLRP5 (also known as MATER) has been extensively studied. In humans, inactivating variants in specific NLRP genes in the mother are associated with distinct phenotypes in the offspring, such as biparental hydatidiform moles (BiHMs) and preterm birth. Maternal-effect recessive mutations in KHDC3L and NLRP5 (and NLRP7) are associated with reduced reproductive outcomes, BiHM, and broad multilocus imprinting perturbations. The precise mechanisms of NLRPs are unknown, but research strongly indicates their pivotal roles in the establishment of genomic imprints and post-zygotic methylation maintenance, among other processes. Challenges for the future include translations of findings from the mouse model into human contexts and implementation in therapies and clinical fertility management., (© The Author(s) 2019. Published by Oxford University Press on behalf of Society for the Study of Reproduction.)
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- 2019
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27. Sortilin gates neurotensin and BDNF signaling to control peripheral neuropathic pain.
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Richner M, Pallesen LT, Ulrichsen M, Poulsen ET, Holm TH, Login H, Castonguay A, Lorenzo LE, Gonçalves NP, Andersen OM, Lykke-Hartmann K, Enghild JJ, Rønn LCB, Malik IJ, De Koninck Y, Bjerrum OJ, Vægter CB, and Nykjær A
- Subjects
- Animals, Down-Regulation physiology, Female, Humans, Hyperalgesia metabolism, Male, Mice, Mice, Inbred C57BL, Peripheral Nerve Injuries metabolism, Receptors, Neurotensin metabolism, Signal Transduction physiology, Adaptor Proteins, Vesicular Transport metabolism, Brain-Derived Neurotrophic Factor metabolism, Neuralgia metabolism, Neurotensin metabolism
- Abstract
Neuropathic pain is a major incurable clinical problem resulting from peripheral nerve trauma or disease. A central mechanism is the reduced expression of the potassium chloride cotransporter 2 (KCC2) in dorsal horn neurons induced by brain-derived neurotrophic factor (BDNF), causing neuronal disinhibition within spinal nociceptive pathways. Here, we demonstrate how neurotensin receptor 2 (NTSR2) signaling impairs BDNF-induced spinal KCC2 down-regulation, showing how these two pathways converge to control the abnormal sensory response following peripheral nerve injury. We establish how sortilin regulates this convergence by scavenging neurotensin from binding to NTSR2, thus modulating its inhibitory effect on BDNF-mediated mechanical allodynia. Using sortilin-deficient mice or receptor inhibition by antibodies or a small-molecule antagonist, we lastly demonstrate that we are able to fully block BDNF-induced pain and alleviate injury-induced neuropathic pain, validating sortilin as a clinically relevant target.
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- 2019
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28. Selectivity, efficacy and toxicity studies of UCCB01-144, a dimeric neuroprotective PSD-95 inhibitor.
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Bach A, Clausen BH, Kristensen LK, Andersen MG, Ellman DG, Hansen PBL, Hasseldam H, Heitz M, Özcelik D, Tuck EJ, Kopanitsa MV, Grant SGN, Lykke-Hartmann K, Johansen FF, Lambertsen KL, and Strømgaard K
- Subjects
- Animals, Brain pathology, Brain Ischemia pathology, Disease Models, Animal, Dose-Response Relationship, Drug, Ethers adverse effects, Ethers therapeutic use, Female, Male, Mice, Neuroprotection drug effects, Neuroprotective Agents adverse effects, Neuroprotective Agents therapeutic use, Rats, Time Factors, Brain drug effects, Brain Ischemia drug therapy, Disks Large Homolog 4 Protein antagonists & inhibitors, Ethers pharmacology, Neuroprotective Agents pharmacology, Signal Transduction drug effects
- Abstract
Inhibition of postsynaptic density protein-95 (PSD-95) decouples N-methyl-d-aspartate (NMDA) receptor downstream signaling and results in neuroprotection after focal cerebral ischemia. We have previously developed UCCB01-144, a dimeric PSD-95 inhibitor, which binds PSD-95 with high affinity and is neuroprotective in experimental stroke. Here, we investigate the selectivity, efficacy and toxicity of UCCB01-144 and compare with the monomeric drug candidate Tat-NR2B9c. Fluorescence polarization using purified proteins and pull-downs of mouse brain lysates showed that UCCB01-144 potently binds all four PSD-95-like membrane-associated guanylate kinases (MAGUKs). In addition, UCCB01-144 affected NMDA receptor signaling pathways in ischemic brain tissue. UCCB01-144 reduced infarct size in young and aged male mice at various doses when administered 30 min after permanent middle cerebral artery occlusion, but UCCB01-144 was not effective in young male mice when administered 1 h post-ischemia or in female mice. Furthermore, UCCB01-144 was neuroprotective in a transient stroke model in rats, and in contrast to Tat-NR2B9c, high dose of UCCB01-144 did not lead to significant changes in mean arterial blood pressure or heart rate. Overall, UCCB01-144 is a potent MAGUK inhibitor that reduces neurotoxic PSD-95-mediated signaling and improves neuronal survival following focal brain ischemia in rodents under various conditions and without causing cardiovascular side effects, which encourages further studies towards clinical stroke trials., (Copyright © 2019 Elsevier Ltd. All rights reserved.)
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- 2019
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29. Editorial: Molecular and Cellular Mechanisms in Reproduction and Early Development.
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Fissore RA, Burton A, and Lykke-Hartmann K
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- 2019
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30. Selectively identify a3Na/K-ATPase expressing cells.
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Lykke-Hartmann K
- Subjects
- Animals, Ions, Mice, Mice, Transgenic, Nervous System, Sodium, Sodium-Potassium-Exchanging ATPase
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- 2019
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31. Increased susceptibility to cortical spreading depression and epileptiform activity in a mouse model for FHM2.
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Kros L, Lykke-Hartmann K, and Khodakhah K
- Subjects
- Age Factors, Animals, Female, Humans, Isoenzymes genetics, Isoenzymes metabolism, Male, Mice, Migraine Disorders genetics, Migraine with Aura pathology, Mutation, Sodium-Potassium-Exchanging ATPase genetics, Cortical Spreading Depression genetics, Disease Models, Animal, Epilepsy genetics, Genetic Predisposition to Disease genetics, Migraine with Aura genetics, Sodium-Potassium-Exchanging ATPase metabolism
- Abstract
Migraine is a highly prevalent, debilitating, episodic headache disorder affecting roughly 15% of the population. Familial hemiplegic migraine type 2 (FHM2) is a rare subtype of migraine caused by mutations in the ATP1A2 gene, encoding the α
2 isoform of the Na+ /K+ -ATPase, predominantly expressed in astrocytes. Differential comorbidities such as epilepsy and psychiatric disorders manifest in patients. Using a mouse model harboring the G301R disease-mutation in the α2 isoform, we set to unravel whether α2 +/G301R mice show an increased susceptibility for epilepsy and cortical spreading depression (CSD). We performed in vivo experiments involving cortical application of KCl in awake head-restrained male and female mice of different age groups (adult and aged). Interestingly, α2 +/G301R mice indeed showed an increased susceptibility to both CSD and epileptiform activity, closely replicating symptoms in FHM2 patients harboring the G301R and other FHM2-causing mutations. Additionally, this epileptiform activity was superimposed on CSDs. The age-related alteration towards CSD indicates the influence of female sex hormones on migraine pathophysiology. Therefore, the FHM2, α2 +/G301R mouse model can be utilized to broaden our understanding of generalized epilepsy and comorbidity hereof in migraine, and may be utilized toward future selection of possible treatment options for migraine.- Published
- 2018
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32. The Endo-Lysosomal System of Brain Endothelial Cells Is Influenced by Astrocytes In Vitro.
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Toth AE, Siupka P, P Augustine TJ, Venø ST, Thomsen LB, Moos T, Lohi HT, Madsen P, Lykke-Hartmann K, and Nielsen MS
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- Animals, Biomarkers metabolism, Gene Expression Regulation, Rats, Wistar, Subcellular Fractions metabolism, Astrocytes metabolism, Brain cytology, Endosomes metabolism, Endothelial Cells metabolism, Lysosomes metabolism
- Abstract
Receptor- and adsorptive-mediated transport through brain endothelial cells (BEC) of the blood-brain barrier (BBB) involves a complex array of subcellular vesicular structures, the endo-lysosomal system. It consists of several types of vesicles, such as early, recycling, and late endosomes, retromer-positive structures, and lysosomes. Since this system is important for receptor-mediated transcytosis of drugs across brain capillaries, our aim was to characterise the endo-lysosomal system in BEC with emphasis on their interactions with astrocytes. We used primary porcine BEC in monoculture and in co-culture with primary rat astrocytes. The presence of astrocytes changed the intraendothelial vesicular network and significantly impacted vesicular number, morphology, and distribution. Additionally, gene set enrichment analysis revealed that 60 genes associated with vesicular trafficking showed altered expression in co-cultured BEC. Cytosolic proteins involved in subcellular trafficking were investigated to mark transport routes, such as RAB25 for transcytosis. Strikingly, the adaptor protein called AP1-μ1B, important for basolateral sorting in epithelial cells, was not expressed in BEC. Altogether, our data pin-point unique features of BEC trafficking network, essentially mapping the endo-lysosomal system of in vitro BBB models. Consequently, our findings constitute a valuable basis for planning the optimal route across the BBB when advancing drug delivery to the brain.
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- 2018
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33. Transcripts Encoding the Androgen Receptor and IGF-Related Molecules Are Differently Expressed in Human Granulosa Cells From Primordial and Primary Follicles.
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Steffensen LL, Ernst EH, Amoushahi M, Ernst E, and Lykke-Hartmann K
- Abstract
Bidirectional cross talk between granulosa cells and oocytes is known to be important in all stages of mammalian follicular development. Insulin-like growth factor (IGF) signaling is a prominent candidate to be involved in the activation of primordial follicles, and may be be connected to androgen-signaling. In this study, we interrogated transcriptome dynamics in granulosa cells isolated from human primordial and primary follicles to reveal information of growth factors and androgens involved in the physiology of ovarian follicular activation. Toward this, a transcriptome comparison study on primordial follicles ( n = 539 follicles) and primary follicles ( n = 261 follicles) donated by three women having ovarian tissue cryopreserved before chemotherapy was performed. The granulosa cell contribution in whole follicle isolates was extracted in silico . Modeling of complex biological systems was performed using IPA® software. We found the granulosa cell compartment of the human primordial and primary follicles to be extensively enriched in genes encoding IGF-related factors, and the Androgen Receptor (AR) enriched in granulosa cells of primordial follicles. Our study hints the possibility that primordial follicles may indeed be androgen responsive, and that the action of androgens represents a connection to the expression of key players in the IGF-signaling pathway including IGF1R, IGF2, and IGFBP3, and that this interaction could be important for early follicular activation. In line with this, several androgen-responsive genes were noted to be expressed in both oocytes and granulosa cells from human primordial and primary follicle. We present a detailed description of AR and IGF gene activities in the human granulosa cell compartment of primordial and primary follicles, suggesting that these cells may be or prepare to be responsive toward androgens and IGFs.
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- 2018
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34. Transcriptome Analysis of Long Non-coding RNAs and Genes Encoding Paraspeckle Proteins During Human Ovarian Follicle Development.
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Ernst EH, Nielsen J, Ipsen MB, Villesen P, and Lykke-Hartmann K
- Abstract
Emerging evidence indicated that many long non-coding (lnc)RNAs function in multiple biological processes and dysregulation of their expression can cause diseases. Most regulatory lncRNAs interact with biological macromolecules such as DNA, RNA, and protein. LncRNAs regulate gene expression through epigenetic modification, transcription, and posttranscription, through DNA methylation, histone modification, and chromatin remodeling. Interestingly, differential lncRNA expression profiles in human oocytes and cumulus cells was recently assessed, however, lncRNAs in human follicle development has not previously been described. In this study, transcriptome dynamics in human primordial, primary and small antral follicles were interrogated and revealed information of lncRNA genes. It is known that some lncRNAs form a complex with paraspeckle proteins and therefore, we extended our transcriptional analysis to include genes encoding paraspeckle proteins. Primordial, primary follicles and small antral follicles was isolated using laser capture micro-dissection from ovarian tissue donated by three women having ovarian tissue cryopreserved before chemotherapy. After RN sequencing, a bioinformatic class comparison was performed and primordial, primary and small antral follicles were found to express several lncRNA and genes encoding paraspeckle proteins. Of particular interest, we detected the lncRNAs XIST, NEAT1, NEAT2 (MALAT1) , and GAS5 . Moreover, we noted a high expression of FUS, TAF15 , and EWS components of the paraspeckles, proteins that belong to the FET (previously TET) family of RNA-binding proteins and are implicated in central cellular processes such as regulation of gene expression, maintenance of genomic integrity, and mRNA/microRNA processing. We also interrogated the intra-ovarian localization of the FUS, TAF15, and EWS proteins using immunofluorescence. The presence and the dynamics of genes that encode lncRNA and paraspeckle proteins may suggest that these may mediate functions in the cyclic recruitment and differentiation of human follicles and could participate in biological processes known to be associated with lncRNAs and paraspeckle proteins, such as gene expression control, scaffold formation and epigenetic control through human follicle development. This comprehensive transcriptome analysis of lncRNAs and genes encoding paraspeckle proteins expressed in human follicles could potentially provide biomarkers of oocyte quality for the development of non-invasive tests to identify embryos with high developmental potential.
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- 2018
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35. Changes in first trimester fetal CYP1A1 and AHRR DNA methylation and mRNA expression in response to exposure to maternal cigarette smoking.
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Fa S, Larsen TV, Bilde K, Daugaard TF, Ernst EH, Lykke-Hartmann K, Olesen RH, Mamsen LS, Ernst E, Larsen A, and Nielsen AL
- Subjects
- Female, Humans, Liver metabolism, Male, Maternal Exposure, Maternal-Fetal Exchange, Placenta metabolism, Pregnancy, RNA, Messenger metabolism, Basic Helix-Loop-Helix Transcription Factors genetics, Cigarette Smoking genetics, Cytochrome P-450 CYP1A1 genetics, DNA Methylation, Pregnancy Trimester, First genetics, Repressor Proteins genetics
- Abstract
Prenatal exposure to maternal cigarette smoking increases the risk of intrauterine growth retardation, adverse pregnancy outcomes, and diseases later in life. Exposure can result in postnatal global and gene-specific DNA methylation changes, with the latter well documented for the CYP1A1 and AHRR genes involved in the detoxification of xenobiotic substances. This study assessed the impact of exposure to maternal smoking on first trimester fetal CYP1A1 and AHRR mRNA expression and DNA methylation for CpG-sites displaying maternal smoking during pregnancy-mediated methylation changes at birth. The analyses included first trimester (6-12 weeks) placentas (N=39) and livers (N=43). For AHRR, exposure to maternal smoking was associated with increased DNA methylation in the placentas of female fetuses; mRNA expression, however, was unchanged. While exposure to maternal smoking was not associated with AHRR DNA methylation changes in fetal livers; mRNA expression was increased. For CYP1A1, exposure to maternal smoking was not associated with fetal DNA methylation changes whereas mRNA expression increased in placentas and male fetal livers. These results show that first trimester exposure to maternal smoking is associated with CYP1A1 and AHRR DNA methylation and mRNA expression changes. However, the results also indicate that maternal smoking during pregnancy-mediated postnatal CYP1A1 and AHRR DNA methylation changes are not imprinted during the first trimester., (Copyright © 2017 Elsevier B.V. All rights reserved.)
- Published
- 2018
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36. The α2β2 isoform combination dominates the astrocytic Na + /K + -ATPase activity and is rendered nonfunctional by the α2.G301R familial hemiplegic migraine type 2-associated mutation.
- Author
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Stoica A, Larsen BR, Assentoft M, Holm R, Holt LM, Vilhardt F, Vilsen B, Lykke-Hartmann K, Olsen ML, and MacAulay N
- Subjects
- Adenosine Triphosphatases genetics, Animals, Animals, Newborn, Arginine genetics, Astrocytes drug effects, Astrocytes physiology, CD11b Antigen metabolism, Cation Transport Proteins genetics, Cell Adhesion Molecules, Neuronal genetics, Cells, Cultured, Excitatory Amino Acids pharmacology, Female, Glycine genetics, Male, Mice, Mice, Inbred C57BL, Mice, Transgenic, Neurons physiology, Oocytes physiology, Protein Isoforms metabolism, Rats, Rats, Sprague-Dawley, Xenopus laevis, Adenosine Triphosphatases metabolism, Cation Transport Proteins metabolism, Cell Adhesion Molecules, Neuronal metabolism, Mutation genetics, Sodium-Potassium-Exchanging ATPase genetics, Sodium-Potassium-Exchanging ATPase metabolism
- Abstract
Synaptic activity results in transient elevations in extracellular K
+ , clearance of which is critical for sustained function of the nervous system. The K+ clearance is, in part, accomplished by the neighboring astrocytes by mechanisms involving the Na+ /K+ -ATPase. The Na+ /K+ -ATPase consists of an α and a β subunit, each with several isoforms present in the central nervous system, of which the α2β2 and α2β1 isoform combinations are kinetically geared for astrocytic K+ clearance. While transcript analysis data designate α2β2 as predominantly astrocytic, the relative quantitative protein distribution and isoform pairing remain unknown. As cultured astrocytes altered their isoform expression in vitro, we isolated a pure astrocytic fraction from rat brain by a novel immunomagnetic separation approach in order to determine the expression levels of α and β isoforms by immunoblotting. In order to compare the abundance of isoforms in astrocytic samples, semi-quantification was carried out with polyhistidine-tagged Na+ /K+ -ATPase subunit isoforms expressed in Xenopus laevis oocytes as standards to obtain an efficiency factor for each antibody. Proximity ligation assay illustrated that α2 paired efficiently with both β1 and β2 and the semi-quantification of the astrocytic fraction indicated that the astrocytic Na+ /K+ -ATPase is dominated by α2, paired with β1 or β2 (in a 1:9 ratio). We demonstrate that while the familial hemiplegic migraine-associated α2.G301R mutant was not functionally expressed at the plasma membrane in a heterologous expression system, α2+/G301R mice displayed normal protein levels of α2 and glutamate transporters and that the one functional allele suffices to manage the general K+ dynamics., (© 2017 Wiley Periodicals, Inc.)- Published
- 2017
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37. Maternally Contributed Folate Receptor 1 Is Expressed in Ovarian Follicles and Contributes to Preimplantation Development.
- Author
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Strandgaard T, Foder S, Heuck A, Ernst E, Nielsen MS, and Lykke-Hartmann K
- Abstract
Folates have been shown to play a crucial role for proper development of the embryo as folate deficiency has been associated with reduced developmental capacity such as increased risk of fetal neural tube defects and spontanous abortion. Transcripts encoding the reduced folate carrier RFC1 (SLC19A1 protein) and the high-affinity folate receptor FOLR1 are expressed in oocytes and preimplantation embryos, respectively. In this study, we observed maternally contributed FOLR1 protein during mouse and human ovarian follicle development, and 2-cell mouse embryos. In mice, FOLR1 was highly enriched in oocytes from primary, secondary and tertiary follicles, and in the surrounding granulosa cells. Interestingly, during human follicle development, we noted a high and specific presence of FOLR1 in oocytes from primary and intermediate follicles, but not in the granulosa cells. The distribution of FOLR1 in follicles was noted as membrane-enriched but also seen in the cytoplasm in oocytes and granulosa cells. In 2-cell embryos, FOLR1-eGFP fusion protein was detected as cytoplasmic and membrane-associated dense structures, resembling the distribution pattern observed in ovarian follicle development. Knock-down of Folr1 mRNA function was accomplished by microinjection of short interference (si)RNA targeting Folr1 , into mouse pronuclear zygotes. This revealed a reduced capacity of Folr1 siRNA-treated embryos to develop to blastocyst compared to the siRNA-scrambled control group, indicating that maternally contributed protein and zygotic transcripts sustain embryonic development combined. In summary, maternally contributed FOLR1 protein appears to maintain ovarian functions, and contribute to preimplantation development combined with embryonically synthesized FOLR1.
- Published
- 2017
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38. The loss-of-function disease-mutation G301R in the Na + /K + -ATPase α 2 isoform decreases lesion volume and improves functional outcome after acute spinal cord injury in mice.
- Author
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Ellman DG, Isaksen TJ, Lund MC, Dursun S, Wirenfeldt M, Jørgensen LH, Lykke-Hartmann K, and Lambertsen KL
- Subjects
- Animals, Genotype, Interleukin-10 metabolism, Isoenzymes genetics, Isoenzymes metabolism, Membrane Potentials genetics, Mice, Transgenic, Mutation genetics, Recovery of Function genetics, Signal Transduction genetics, Signal Transduction physiology, Sodium-Potassium-Exchanging ATPase genetics, Spinal Cord Injuries genetics, Cell Membrane metabolism, Recovery of Function physiology, Sodium-Potassium-Exchanging ATPase metabolism, Spinal Cord Injuries physiopathology
- Abstract
Background: The Na
+ /K+ -ATPases are transmembrane ion pumps important for maintenance of ion gradients across the plasma membrane that serve to support multiple cellular functions, such as membrane potentials, regulation of cellular volume and pH, and co-transport of signaling transmitters in all animal cells. The α2 Na+ /K+ -ATPase subunit isoform is predominantly expressed in astrocytes, which us the sharp Na+ -gradient maintained by the sodium pump necessary for astroglial metabolism. Prolonged ischemia induces an elevation of [Na+ ]i , decreased ATP levels and intracellular pH owing to anaerobic metabolism and lactate accumulation. During ischemia, Na+ /K+ -ATPase-related functions will naturally increase the energy demand of the Na+ /K+ -ATPase ion pump. However, the role of the α2 Na+ /K+ -ATPase in contusion injury to the spinal cord remains unknown. We used mice heterozygous mice for the loss-of-function disease-mutation G301R in the Atp1a2 gene (α2 +/G301R ) to study the effect of reduced α2 /K+ /K+ -ATPase expression in a moderate contusion spinal cord injury (SCI) model., Results: We found that α2 +/G301R mice display significantly improved functional recovery and decreased lesion volume compared to littermate controls (α2 +/+ ) 7 days after SCI. The protein level of the α1 isoform was significantly increased, in contrast to the α3 isoform that significantly decreased 3 days after SCI in both α2 +/G301R and α2 +/+ mice. The level of the α2 isoform was significantly decreased in α2 +/G301R mice both under naïve conditions and 3 days after SCI compared to α2 +/+ mice. We found no differences in astroglial aquaporin 4 levels and no changes in the expression of chemokines (CCL2, CCL5 and CXCL1) and cytokines (TNF, IL-6, IL-1β, IL-10 and IL-5) between genotypes, just as no apparent differences were observed in location and activation of CD45 and F4/80 positive microglia and infiltrating leukocytes., Conclusion: Our proof of concept study demonstrates that reduced expression of the α2 isoform in the spinal cord is protective following SCI. Importantly, the BMS and lesion volume were assessed at 7 days after SCI, and longer time points after SCI were not evaluated. However, the α2 isoform is a potential possible target of therapeutic strategies for the treatment of SCI.- Published
- 2017
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39. Bidirectional apical-basal traffic of the cation-independent mannose-6-phosphate receptor in brain endothelial cells.
- Author
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Siupka P, Hersom MN, Lykke-Hartmann K, Johnsen KB, Thomsen LB, Andresen TL, Moos T, Abbott NJ, Brodin B, and Nielsen MS
- Subjects
- Animals, Blood-Brain Barrier metabolism, Cattle, Cells, Cultured, Coculture Techniques, Fibroblasts metabolism, Humans, Mice, Models, Biological, Pharmaceutical Preparations metabolism, Protein Transport, Rats, Receptor, IGF Type 2 genetics, Swine, Astrocytes metabolism, Brain blood supply, Capillaries metabolism, Endothelial Cells metabolism, Endothelium, Vascular metabolism, Receptor, IGF Type 2 metabolism
- Abstract
Brain capillary endothelium mediates the exchange of nutrients between blood and brain parenchyma. This barrier function of the brain capillaries also limits passage of pharmaceuticals from blood to brain, which hinders treatment of several neurological disorders. Receptor-mediated transport has been suggested as a potential pharmaceutical delivery route across the brain endothelium, e.g. reports have shown that the transferrin receptor (TfR) facilitates transcytosis of TfR antibodies, but it is not known whether this recycling receptor itself traffics from apical to basal membrane in the process. Here, we elucidate the endosomal trafficking of the retrograde transported cation-independent mannose-6-phosphate receptor (MPR300) in primary cultures of brain endothelial cells (BECs) of porcine and bovine origin. Receptor expression and localisation of MPR300 in the endo-lysosomal system and trafficking of internalised receptor are analysed. We also demonstrate that MPR300 can undergo bidirectional apical-basal trafficking in primary BECs in co-culture with astrocytes. This is, to our knowledge, the first detailed study of retrograde transported receptor trafficking in BECs, and the study demonstrates that MPR300 can be transported from the luminal to abluminal membrane and reverse. Such trafficking of MPR300 suggests that retrograde transported receptors in general may provide a mechanism for transport of pharmaceuticals into the brain.
- Published
- 2017
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40. Hypothermia-induced dystonia and abnormal cerebellar activity in a mouse model with a single disease-mutation in the sodium-potassium pump.
- Author
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Isaksen TJ, Kros L, Vedovato N, Holm TH, Vitenzon A, Gadsby DC, Khodakhah K, and Lykke-Hartmann K
- Subjects
- Animals, Dystonic Disorders etiology, Hemiplegia etiology, Heterozygote, Hypothermia complications, Mice, Mice, Inbred C57BL, Muscle Contraction, Parkinson Disease etiology, Purkinje Cells physiology, Sodium metabolism, Xenopus, Action Potentials, Dystonic Disorders genetics, Hemiplegia genetics, Mutation, Parkinson Disease genetics, Purkinje Cells metabolism, Sodium-Potassium-Exchanging ATPase genetics
- Abstract
Mutations in the neuron-specific α3 isoform of the Na+/K+-ATPase are found in patients suffering from Rapid onset Dystonia Parkinsonism and Alternating Hemiplegia of Childhood, two closely related movement disorders. We show that mice harboring a heterozygous hot spot disease mutation, D801Y (α3+/D801Y), suffer abrupt hypothermia-induced dystonia identified by electromyographic recordings. Single-neuron in vivo recordings in awake α3+/D801Y mice revealed irregular firing of Purkinje cells and their synaptic targets, the deep cerebellar nuclei neurons, which was further exacerbated during dystonia and evolved into abnormal high-frequency burst-like firing. Biophysically, we show that the D-to-Y mutation abolished pump-mediated Na+/K+ exchange, but allowed the pumps to bind Na+ and become phosphorylated. These findings implicate aberrant cerebellar activity in α3 isoform-related dystonia and add to the functional understanding of the scarce and severe mutations in the α3 isoform Na+/K+-ATPase.
- Published
- 2017
- Full Text
- View/download PDF
41. Neuronal Ablation of IKK2 Decreases Lesion Size and Improves Functional Outcome after Spinal Cord Injury in Mice.
- Author
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Ellman DG, Novrup HG, Jørgensen LH, Lund MC, Yli-Karjanmaa M, Madsen PM, Vienhues JH, Dursun S, Bethea JR, Lykke-Hartmann K, Brambilla R, and Lambertsen KL
- Abstract
Nuclear factor-kappa B (NF-κB) is a key modulator of inflammation and secondary injury responses in neurodegenerative disease, including spinal cord injury (SCI). Inhibition of astroglial NF-κB reduces inflammation, enhances oligodendrogenesis and improves functional recovery after SCI, however the contribution of neuronal NF-κB to secondary inflammatory responses following SCI has yet to be investigated. We demonstrate that conditional ablation of IKK2 in Synapsin 1-expressing neurons in mice (Syn1creIKK2
fl/fl ) reduces activation of the classical NF-κB signaling pathway, resulting in impaired motor function and altered memory retention under naïve conditions. Following induction of a moderate SCI phosphorylated NF-κB levels decreased in the spinal cord of Syn1creIKK2fl/fl mice compared to controls, resulting in improvement in functional recovery. Histologically, Syn1creIKK2fl/fl mice exhibited reduced lesion volume but comparable microglial/leukocyte responses after SCI. In parallel, interleukin (IL)-1β expression was significantly decreased within the lesioned spinal cord, whereas IL-5, IL-6, IL-10, tumor necrosis factor (TNF) and chemokine (C-X-C motif) ligand 1 were unchanged compared to control mice. We conclude that conditional ablation of IKK2 in neurons, resulting in reduced neuronal NF-B signaling, and lead to protective effects after SCI and propose the neuronal classical NF-κB pathway as a potential target for the development of new therapeutic, neuroprotective strategies for SCI.- Published
- 2017
42. TRPM7-like channels are functionally expressed in oocytes and modulate post-fertilization embryo development in mouse.
- Author
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Carvacho I, Ardestani G, Lee HC, McGarvey K, Fissore RA, and Lykke-Hartmann K
- Abstract
The Transient Receptor Potential (TRP) channels are a family of cationic ion channels widely distributed in mammalian tissues. In general, the global genetic disruption of individual TRP channels result in phenotypes associated with impairment of a particular tissue and/or organ function. An exception is the genetic ablation of the TRP channel TRPM7, which results in early embryonic lethality. Nevertheless, the function of TRPM7 in oocytes, eggs and pre-implantation embryos remains unknown. Here, we described an outward rectifying non-selective current mediated by a TRP ion channel in immature oocytes (germinal vesicle stage), matured oocytes (metaphase II eggs) and 2-cell stage embryos. The current is activated by specific agonists and inhibited by distinct blockers consistent with the functional expression of TRPM7 channels. We demonstrated that the TRPM7-like channels are homo-tetramers and their activation mediates calcium influx in oocytes and eggs, which is fundamental to support fertilization and egg activation. Lastly, we showed that pharmacological inhibition of the channel function delays pre-implantation embryo development and reduces progression to the blastocyst stage. Our data demonstrate functional expression of TRPM7-like channels in mouse oocytes, eggs and embryos that may play an essential role in the initiation of embryo development.
- Published
- 2016
- Full Text
- View/download PDF
43. Cognitive deficits caused by a disease-mutation in the α3 Na(+)/K(+)-ATPase isoform.
- Author
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Holm TH, Isaksen TJ, Glerup S, Heuck A, Bøttger P, Füchtbauer EM, Nedergaard S, Nyengaard JR, Andreasen M, Nissen P, and Lykke-Hartmann K
- Subjects
- Animals, CA1 Region, Hippocampal metabolism, Cell Line, Cognition Disorders psychology, Disease Models, Animal, Gene Knock-In Techniques, Humans, Male, Memory, Mice, Phenotype, Seizures chemically induced, Sodium-Potassium-Exchanging ATPase metabolism, Spatial Learning, Cognition Disorders genetics, Mutation, Seizures genetics, Sodium-Potassium-Exchanging ATPase genetics
- Abstract
The Na(+)/K(+)-ATPases maintain Na(+) and K(+) electrochemical gradients across the plasma membrane, a prerequisite for electrical excitability and secondary transport in neurons. Autosomal dominant mutations in the human ATP1A3 gene encoding the neuron-specific Na(+)/K(+)-ATPase α3 isoform cause different neurological diseases, including rapid-onset dystonia-parkinsonism (RDP) and alternating hemiplegia of childhood (AHC) with overlapping symptoms, including hemiplegia, dystonia, ataxia, hyperactivity, epileptic seizures, and cognitive deficits. Position D801 in the α3 isoform is a mutational hotspot, with the D801N, D801E and D801V mutations causing AHC and the D801Y mutation causing RDP or mild AHC. Despite intensive research, mechanisms underlying these disorders remain largely unknown. To study the genotype-to-phenotype relationship, a heterozygous knock-in mouse harboring the D801Y mutation (α3(+/D801Y)) was generated. The α3(+/D801Y) mice displayed hyperactivity, increased sensitivity to chemically induced epileptic seizures and cognitive deficits. Interestingly, no change in the excitability of CA1 pyramidal neurons in the α3(+/D801Y) mice was observed. The cognitive deficits were rescued by administration of the benzodiazepine, clonazepam, a GABA positive allosteric modulator. Our findings reveal the functional significance of the Na(+)/K(+)-ATPase α3 isoform in the control of spatial learning and memory and suggest a link to GABA transmission.
- Published
- 2016
- Full Text
- View/download PDF
44. Insights into the Pathology of the α3 Na(+)/K(+)-ATPase Ion Pump in Neurological Disorders; Lessons from Animal Models.
- Author
-
Holm TH and Lykke-Hartmann K
- Abstract
The transmembrane Na(+)-/K(+) ATPase is located at the plasma membrane of all mammalian cells. The Na(+)-/K(+) ATPase utilizes energy from ATP hydrolysis to extrude three Na(+) cations and import two K(+) cations into the cell. The minimum constellation for an active Na(+)-/K(+) ATPase is one alpha (α) and one beta (β) subunit. Mammals express four α isoforms (α1-4), encoded by the ATP1A1-4 genes, respectively. The α1 isoform is ubiquitously expressed in the adult central nervous system (CNS) whereas α2 primarily is expressed in astrocytes and α3 in neurons. Na(+) and K(+) are the principal ions involved in action potential propagation during neuronal depolarization. The α1 and α3 Na(+)-/K(+) ATPases are therefore prime candidates for restoring neuronal membrane potential after depolarization and for maintaining neuronal excitability. The α3 isoform has approximately four-fold lower Na(+) affinity compared to α1 and is specifically required for rapid restoration of large transient increases in [Na(+)]i. Conditions associated with α3 deficiency are therefore likely aggravated by suprathreshold neuronal activity. The α3 isoform been suggested to support re-uptake of neurotransmitters. These processes are required for normal brain activity, and in fact autosomal dominant de novo mutations in ATP1A3 encoding the α3 isoform has been found to cause the three neurological diseases Rapid Onset Dystonia Parkinsonism (RDP), Alternating Hemiplegia of Childhood (AHC), and Cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss (CAPOS). All three diseases cause acute onset of neurological symptoms, but the predominant neurological manifestations differ with particularly early onset of hemiplegic/dystonic episodes and mental decline in AHC, ataxic encephalopathy and impairment of vision and hearing in CAPOS syndrome and late onset of dystonia/parkinsonism in RDP. Several mouse models have been generated to study the in vivo consequences of Atp1a3 modulation. The different mice show varying degrees of hyperactivity, gait problems, and learning disability as well as stress-induced seizures. With the advent of several Atp1a3-gene or chemically modified animal models that closely phenocopy many aspects of the human disorders, we will be able to reach a much better understanding of the etiology of RDP, AHC, and CAPOS syndrome.
- Published
- 2016
- Full Text
- View/download PDF
45. Insights into the Pathology of the α2-Na(+)/K(+)-ATPase in Neurological Disorders; Lessons from Animal Models.
- Author
-
Isaksen TJ and Lykke-Hartmann K
- Abstract
A functional Na(+)/K(+)-ATPase consists of a catalytic α subunit and a regulatory β subunit. Four α isoforms of the Na(+)/K(+)-ATPase are found in mammals, each with a unique expression pattern and catalytic activity. The α2 isoform, encoded by the ATP1A2 gene, is primarily found in the central nervous system (CNS) and in heart-, skeletal- and smooth muscle tissues. In the CNS, the α2 isoform is mainly expressed in glial cells. In particular, the α2 isoform is found in astrocytes, important for astrocytic K(+) clearance and, consequently, the indirect uptake of neurotransmitters. Both processes are essential for proper brain activity, and autosomal dominantly mutations in the ATP1A2 gene cause the neurological disorder Familial hemiplegic migraine type 2 (FHM2). FHM2 is a severe subtype of migraine with aura including temporary numbness or weakness, and affecting only one side of the body. FHM2 patients often suffer from neurological comorbidities such as seizures, sensory disturbances, cognitive impairment, and psychiatric manifestations. The functional consequences of FHM2 disease mutations leads to a partial or complete loss of function of pump activity; however, a clear phenotype-genotype correlation has yet to be elucidated. Gene-modified mouse models targeting the Atp1a2 gene have proved instrumental in the understanding of the pathology of FHM2. Several Atp1a2 knockout (KO) mice targeting different exons have been reported. Homozygous Atp1a2 KO mice die shortly after birth due to respiratory malfunction resulting from abnormal Cl(-) homeostasis in brainstem neurons. Heterozygous KO mice are viable, but display altered behavior and neurological deficits such as altered spatial learning, decreased motor activity and enhanced fear/anxiety compared to wild type mice. FHM2 knock-in (KI) mouse models carrying the human in vivo disease mutations W887R and G301R have also been reported. Both models display altered cortical spreading depression (CSD) and point to deficits in the glutamatergic system as the main underlying mechanism of FHM2.
- Published
- 2016
- Full Text
- View/download PDF
46. Glutamate-system defects behind psychiatric manifestations in a familial hemiplegic migraine type 2 disease-mutation mouse model.
- Author
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Bøttger P, Glerup S, Gesslein B, Illarionova NB, Isaksen TJ, Heuck A, Clausen BH, Füchtbauer EM, Gramsbergen JB, Gunnarson E, Aperia A, Lauritzen M, Lambertsen KL, Nissen P, and Lykke-Hartmann K
- Subjects
- Acoustic Stimulation, Animals, Behavior, Animal, Biological Transport, Cerebrovascular Circulation, Computational Biology methods, Cortical Spreading Depression genetics, Disease Models, Animal, Female, Gonadal Steroid Hormones metabolism, Male, Mice, Mice, Transgenic, Migraine with Aura diagnosis, Migraine with Aura drug therapy, Motor Activity, Reaction Time, Sodium-Potassium-Exchanging ATPase genetics, Stress, Physiological, Glutamic Acid metabolism, Migraine with Aura genetics, Migraine with Aura metabolism, Mutation, Phenotype
- Abstract
Migraine is a complex brain disorder, and understanding the complexity of this prevalent disease could improve quality of life for millions of people. Familial Hemiplegic Migraine type 2 (FHM2) is a subtype of migraine with aura and co-morbidities like epilepsy/seizures, cognitive impairments and psychiatric manifestations, such as obsessive-compulsive disorder (OCD). FHM2 disease-mutations locate to the ATP1A2 gene encoding the astrocyte-located α2-isoform of the sodium-potassium pump (α2Na(+)/K(+)-ATPase). We show that knock-in mice heterozygous for the FHM2-associated G301R-mutation (α2(+/G301R)) phenocopy several FHM2-relevant disease traits e.g., by mimicking mood depression and OCD. In vitro studies showed impaired glutamate uptake in hippocampal mixed astrocyte-neuron cultures from α2(G301R/G301R) E17 embryonic mice, and moreover, induction of cortical spreading depression (CSD) resulted in reduced recovery in α2(+/G301R) male mice. Moreover, NMDA-type glutamate receptor antagonists or progestin-only treatment reverted specific α2(+/G301R) behavioral phenotypes. Our findings demonstrate that studies of an in vivo relevant FHM2 disease knock-in mouse model provide a link between the female sex hormone cycle and the glutamate system and a link to co-morbid psychiatric manifestations of FHM2.
- Published
- 2016
- Full Text
- View/download PDF
47. Tuning of the Na,K-ATPase by the beta subunit.
- Author
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Hilbers F, Kopec W, Isaksen TJ, Holm TH, Lykke-Hartmann K, Nissen P, Khandelia H, and Poulsen H
- Subjects
- Animals, Blotting, Western, Cerebellum enzymology, Cerebellum pathology, Humans, Ions metabolism, Lipid Bilayers chemistry, Lipid Bilayers metabolism, Mice, Mice, Inbred C57BL, Microscopy, Fluorescence, Molecular Dynamics Simulation, Oocytes metabolism, Patch-Clamp Techniques, Plasmids metabolism, Protein Structure, Tertiary, Protein Subunits chemistry, Protein Subunits genetics, Protein Subunits metabolism, Sodium metabolism, Sodium-Potassium-Exchanging ATPase chemistry, Sodium-Potassium-Exchanging ATPase genetics, Xenopus laevis growth & development, Xenopus laevis metabolism, Sodium-Potassium-Exchanging ATPase metabolism
- Abstract
The vital gradients of Na(+) and K(+) across the plasma membrane of animal cells are maintained by the Na,K-ATPase, an αβ enzyme complex, whose α subunit carries out the ion transport and ATP hydrolysis. The specific roles of the β subunit isoforms are less clear, though β2 is essential for motor physiology in mammals. Here, we show that compared to β1 and β3, β2 stabilizes the Na(+)-occluded E1P state relative to the outward-open E2P state, and that the effect is mediated by its transmembrane domain. Molecular dynamics simulations further demonstrate that the tilt angle of the β transmembrane helix correlates with its functional effect, suggesting that the relative orientation of β modulates ion binding at the α subunit. β2 is primarily expressed in granule neurons and glomeruli in the cerebellum, and we propose that its unique functional characteristics are important to respond appropriately to the cerebellar Na(+) and K(+) gradients.
- Published
- 2016
- Full Text
- View/download PDF
48. TRPV3 channels mediate Ca²⁺ influx induced by 2-APB in mouse eggs.
- Author
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Lee HC, Yoon SY, Lykke-Hartmann K, Fissore RA, and Carvacho I
- Subjects
- Animals, Cell Membrane drug effects, Cell Membrane metabolism, Female, Mice, TRPV Cation Channels antagonists & inhibitors, Boron Compounds pharmacology, Calcium metabolism, Oocytes drug effects, Oocytes metabolism, TRPV Cation Channels physiology
- Abstract
Fertilization in mammals is initiated when a sperm fuses with a mature MII oocyte, also known as egg, and triggers a plethora of finely controlled processes identified as egg activation. The completion of all events of egg activation is driven by and depends on a series of repetitive calcium (Ca(2+)) increases (Ca(2+) oscillations), which rely on Ca(2+) influx from the extracellular media. Ca(2+) channels on the egg plasma membrane (PM) are thought to mediate this influx. The TRP Ca(2+) channel TRPV3 is differentially expressed during oocyte maturation, being most active at the MII stage. Specific stimulation of TRPV3 channels promotes Ca(2+) influx sufficient to induce egg activation and parthenogenesis. Here, we explore the function and distribution dynamics of the TRPV3 channel protein during maturation. Using dsRNA, TrpV3 overexpression, and inhibitors of protein synthesis, we modified the expression levels of the channel and showed that the TRPV3 protein is synthesized and translocated to the PM during maturation. We demonstrated that 2-APB at the concentrations used here to promote Ca(2+) influx in eggs, specifically and reversibly targets TRPV3 channels without blocking IP3R1. Finally, we found that the activity of TRPV3 channels is dependent upon an intact actin cytoskeleton, suggesting an actin-based regulation of its expression and/or function on the PM. Collectively, our results show TRPV3 is a target of 2-APB in eggs, a condition that can be used to induce parthenogenesis. The need of an intact actin cytoskeleton for the function of TRPV3 channels in oocytes is a novel finding and suggests the rearrangements of actin that occur during maturation could regulate both the presence on the PM and/or the function of TRPV3 and of other Ca(2+) channels involved in oocyte maturation and fertilization., (Copyright © 2015 Elsevier Ltd. All rights reserved.)
- Published
- 2016
- Full Text
- View/download PDF
49. Whole-Mount Immunohistochemistry for Anti-F59 in Zebrafish Embryos (1-5 Days Post Fertilization (dpf)).
- Author
-
Doganli C, Bukata L, and Lykke-Hartmann K
- Subjects
- Animals, Embryo, Nonmammalian physiology, Gene Knockdown Techniques, Isoenzymes deficiency, Isoenzymes genetics, Mutation, Myosin Heavy Chains metabolism, Sodium-Potassium-Exchanging ATPase deficiency, Sodium-Potassium-Exchanging ATPase genetics, Staining and Labeling, Time Factors, Embryo, Nonmammalian metabolism, Fertilization, Immunohistochemistry methods, Zebrafish embryology
- Abstract
Immunohistochemistry (IHC) is a powerful method to determine localization of tissue components by the interaction of target antigens with labeled antibodies. Here we describe an IHC protocol for localizing the myosin heavy chain of zebrafish embryos at 1-2 and 3-5 days post fertilization (dpf).
- Published
- 2016
- Full Text
- View/download PDF
50. Zebrafish Whole-Mount In Situ Hybridization Followed by Sectioning.
- Author
-
Doganli C, Nyengaard JR, and Lykke-Hartmann K
- Subjects
- Animals, Embryo, Nonmammalian metabolism, Female, RNA Probes genetics, In Situ Hybridization methods, Staining and Labeling methods, Zebrafish embryology
- Abstract
In situ hybridization is a powerful technique used for locating specific nucleic acid targets within morphologically preserved tissues and cell preparations. A labeled RNA or DNA probe hybridizes to its complementary mRNA or DNA sequence within a sample. Here, we describe RNA in situ hybridization protocol for whole-mount zebrafish embryos.
- Published
- 2016
- Full Text
- View/download PDF
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