24 results on '"Savolainen, Mari"'
Search Results
2. Prolyl Oligopeptidase Regulates Dopamine Transporter Phosphorylation in the Nigrostriatal Pathway of Mouse
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Julku, Ulrika H, Panhelainen, Anne E, Tiilikainen, Saija E, Svarcbahs, Reinis, Tammimäki, Anne E, Piepponen, T Petteri, Savolainen, Mari H, and Myöhänen, Timo T
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- 2018
- Full Text
- View/download PDF
3. Disease Modification Through Trophic Factor Delivery
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Savolainen, Mari, primary, Emerich, Dwaine, additional, and Kordower, Jeffrey H., additional
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- 2018
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4. Nigral injection of a proteasomal inhibitor, lactacystin, induces widespread glial cell activation and shows various phenotypes of Parkinson’s disease in young and adult mouse
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Savolainen, Mari H., Albert, Katrina, Airavaara, Mikko, and Myöhänen, Timo T.
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- 2017
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5. Analysis of oxysterols and vitamin D metabolites in mouse brain and cell line samples by ultra-high-performance liquid chromatography-atmospheric pressure photoionization–mass spectrometry
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Ahonen, Linda, Maire, Florian B.R., Savolainen, Mari, Kopra, Jaakko, Vreeken, Rob J., Hankemeier, Thomas, Myöhänen, Timo, Kylli, Petri, and Kostiainen, Risto
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- 2014
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- View/download PDF
6. Hypothalamic prolyl endopeptidase (PREP) regulates pancreatic insulin and glucagon secretion in mice
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Kim, Jung Dae, Toda, Chitoku, D'Agostino, Giuseppe, Zeiss, Caroline J., DiLeone, Ralph J., Elsworth, John D., Kibbey, Richard G., Chan, Owen, Harvey, Brandon K., Richie, Christopher T., Savolainen, Mari, Myöhännen, Timo, Jeong, Jin Kwon, and Diano, Sabrina
- Published
- 2014
7. Constitutive Ret signaling leads to long-lasting expression of amphetamine-induced place conditioning via elevation of mesolimbic dopamine
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Kopra, Jaakko, Villarta-Aguilera, Marian, Savolainen, Mari, Weingerl, Samo, Myöhänen, Timo T., Rannanpää, Saara, Salvatore, Michael F., Andressoo, Jaan-Olle, and Piepponen, Petteri T.
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- 2018
- Full Text
- View/download PDF
8. Agonist activation of α7 nicotinic acetylcholine receptors via an allosteric transmembrane site
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Gill, JasKiran K., Savolainen, Mari, Young, Gareth T., Zwart, Ruud, Sher, Emanuele, Millar, Neil S., and Changeux, Jean-Pierre
- Published
- 2011
9. Basal and Graded 6-OHDA –induced Differences in Striatal Dopamine and its Metabolites in two Mouse Lines with A30P–Mutated Alpha-Synuclein
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Piltonen, Marjo, primary, Savolainen, Mari, additional, Myöhänen, Timo T., additional, and Männistö, Pekka T., additional
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- 2014
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10. A grounded theory research — How film industry professionals perceive actors’ personal branding in the Nordic countries
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Mattila, Pekka, Järventie-Thesleff, Rita, Kauppakorkeakoulu, School of Business, Johtamisen laitos, Savolainen, Mari Nika, Mattila, Pekka, Järventie-Thesleff, Rita, Kauppakorkeakoulu, School of Business, Johtamisen laitos, and Savolainen, Mari Nika
- Abstract
Personal branding is becoming an increasingly global phenomenon. Most research touching the topic of actors, actors’ branding or stardom, however, has generally focused on the American and the Hollywood context. A large part of the research around this topic also concentrates on how the process of branding is carried out, not on how this phenomenon is perceived. The objective of this research is to study actors’ personal branding from a film industry perspective and, more precisely, to investigate the attitudes and associations that exist towards this phenomenon in the geographical context of the Nordic countries. This study is designed to fill gaps in both the field of academic personal branding research as well as in research on actors’ personal branding in the Nordic region. It aims to answer the following research questions in the context of the Nordic countries and their film industry: (1) How do film industry professionals perceive actors’ personal branding? (2) How important is actors’ personal branding for the industry professionals? The research was conducted using qualitative methods and, more precisely, a grounded theory approach, both during the data gathering and the analysis phases. The study consists of a set of 13 semi-structured interviews covering all five Nordic countries. The interviews were recorded and, during the data analysis phase, transcribed, coded and analyzed. Open, axial and selective coding were used to identify similarities and differences, after which sub-categories were detected. Finally, deriving from the sub-categories, the main themes and top categories were identified. Three main themes were found: (1) depreciation, (2) attention shift, and (3) avoidance (these themes describe the prevalent manners in which respondents related to the topic of personal branding). Of interest is how all three themes seem to express an indifferent tone and could be placed under a, yet, superior category of indifference or ignoring. In this context, Henkilöbrändäys on muuttumassa yhä globaalimmaksi ilmiöksi. Siitä huolimatta valtaosa tutkimuksista, jotka käsittelevät näyttelijöitä, näyttelijä brändäystä tai tähteyttä, keskittyvät amerikkalaiseen, Hollywoodin kontekstiin. Lisäksi, suuri osa tätä aihetta koskevasta tutkimuksesta keskittyy siihen, miten brändäys prosessi tapahtuu, muttei siihen kuinka tämä ilmiö koetaan. Tämän tutkimuksen päätavoitteena oli tutkia näyttelijöiden henkilöbrändäystä elokuvateollisuuden näkökulmasta. Tarkoituksena oli tutkia asenteita ja assosiaatioita, joita pohjoismaiset elokuva-alan ammattilaiset liittävät kyseiseen ilmiöön. Aihe on tärkeä, koska kyseistä ilmiötä on tutkittu yleisesti ottaen vähän - puutetta ilmenee sekä akateemisessa henkilöbrändäyksen tutkimuksessa että näyttelijöiden henkilöbrändäystä Pohjoismaissa käsittelevässä tutkimuksessa. Tutkimuksen tavoitteena oli vastata seuraaviin tutkimuskysymyksiin pohjoismaisen elokuvateollisuuden näkökulmasta: (1) Miten elokuva-alan ammattilaiset käsittävät näyttelijöiden henkilöbrändäyksen? (2) Kuinka tärkeää näyttelijöiden henkilöbrändäys on elokuva-alan ammattilaisille? Tutkimus suoritettiin laadullista tutkimusmenetelmää käyttäen. Tutkimusmetodina toimi grounded theory- menetelmä, niin tiedonkeruun kuin analysointivaiheen aikana. Tutkimus koostui kolmestatoista puolistrukturoidusta haastattelusta, kattaen kaikki viisi Pohjoismaata. Kaikki haastattelut nauhoitettiin, minkä jälkeen ne litteroitiin, koodattiin ja analysoitiin. Avointa, aksiaalista ja selektiivistä koodausta käytettiin tunnistamaan tutkimusmateriaalissa esiintyviä yhtäläisyyksiä ja eroja. Ala-kategoriat tunnistettiin ja lopulta niistä johdettiin pääteemat ja ylä-kategoriat. Tuloksena löytyi kolme pääteemaa: (1) vähättely, (2) huomion siirto, ja (3) välttäminen (nämä teemat kuvaavat tapoja, joilla vastaajat suhtautuivat henkilöbrändäykseen). Mielenkiintoista oli, kuinka kaikilla kolmella teemalla näyttäisi olevan välinpitämättömyyteen viittaava sävy ja kuinka nämä t
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- 2020
11. Temporal evolution of microglia and α-synuclein accumulation following foetal grafting in Parkinson’s disease
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Olanow, C Warren, primary, Savolainen, Mari, additional, Chu, Yaping, additional, Halliday, Glenda M, additional, and Kordower, Jeffrey H, additional
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- 2019
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12. Prolyl oligopeptidase inhibition attenuates the toxicity of a proteasomal inhibitor, lactacystin, in the alpha-synuclein overexpressing cell culture
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Myöhänen, Timo T., primary, Norrbacka, Susanna, additional, and Savolainen, Mari H., additional
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- 2017
- Full Text
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13. The Effects of Prolyl Oligopeptidase Inhibition in α-Synuclein Based Mouse Models of Parkinson's Disease
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Savolainen, Mari, University of Helsinki, Faculty of Pharmacy, Division of Pharmacology and pharmacotherapy, Helsingin yliopisto, farmasian tiedekunta, Helsingfors universitet, farmaceutiska fakulteten, Tanila, Heikki, Männistö, Pekka, and Myöhänen, Timo
- Subjects
farmakologia ,farmasia - Abstract
Parkinson's disease (PD) is characterized by a slow and gradual loss of neurons and subsequent loss of neurotransmitter dopamine in the movement-related nigrostriatal brain tracts. This causes symptoms of PD, which are resting tremor, rigidity and slowness of movement. Genetic and environmental factors are linked to PD, but its etiology is still largely unknown. Current drug therapies can only relieve the symptoms of PD but treatment to stop or delay the disease progression does not exist at the moment. The main findings in neuropathological characterization of the brain regions that are influenced in PD, are abnormal intraneuronal protein inclusions, called Lewy bodies. Insoluble, aggregated α-synuclein (aSyn) protein is the most abundant component of Lewy bodies. Pathological aggregation and accumulation of aSyn is associated with neuronal death in PD. Therefore, approaches to target aSyn as a potential disease-modifying treatment for PD have been under investigation. The aim of this study was to examine the role of prolyl oligopeptidase (PREP) and pharmacological inhibition of its enzymatic activity by KYP-2047 in aSyn aggregation. Using purified proteins and cell culture model, we showed that PREP forms direct protein-protein interaction with aSyn, thus enhancing its aggregation. KYP-2047 reduced the PREP-mediated aSyn aggregation in cell culture. Then the effects of PREP inhibition on aSyn aggregation were examined in vivo. The purpose was to first characterize a genetic mouse model, carrying mouse A30P mutated aSyn, which is linked to early-onset PD in humans, in order to find out if the mutated mouse aSyn is more prone to aggregate; and to cause PD-like phenotype. The effects of KYP-2047 treatments were assessed in the model. The main findings were that the A30P mutation in mouse aSyn protein caused minor hyperactive behaviour but did not change the brain dopamine levels, and A30P aSyn accumulated in the brain more than wildtype aSyn by age. KYP-2047 treatment reduced the amount of A30P aSyn in immunohistochemical analysis, and the reduction was more specific for high-molecular weight aSyn oligomers in Western blot analysis. We also observed increased autophagy markers in brain tissue. Therefore, PREP inhibition was further studied in cell culture, where it was shown to enhance macroautophagic protein clearance pathway, which is an important pathway in the degradation of high-molecular weight aSyn forms. In the last study, the effects of KYP-2047 were examined in a mouse model of PD that was based on lactacystin-induced inhibition of ubiquitin-proteasome protein degradation pathway. Proteasome inhibition was shown to induce rapid PD-like neurodegeneration recapitulating the cardinal features of PD. KYP-2047 treatment partially protected dopaminergic neurons in the brain and had beneficial effect on motor behaviour, but did not have an effect on aSyn amount. Taken together, this study has provided new insights into the role of PREP in aSyn aggregation and suggest that PREP inhibition has beneficial effects on reducing the aggregation process via two mechanisms. PREP inhibition could be promising and further assessed in the treatment of PD, other α-synucleinopathies and possibly other protein accumulation diseases. Parkinsonin tauti on aivoja rappeuttava sairaus, jota sairastaa keskimäärin prosentti yli 60-vuotiaista. Taudissa mustatumakkeeksi kutsutun aivoalueen dopamiini-välittäjäainetta tuottavat hermosolut tuhoutuvat hitaasti. Dopamiini on tärkeä välittäjäaine liikettä säätelevällä hermoradalla, ja sen vähentyminen saa aikaan Parkinsonin taudille tyypillistä lepovapinaa, lihasten jäykkyyttä ja liikkeiden hitautta. Parkinsonin taudin synty on suurelta osin tuntematon, mutta siihen on liitetty esimerkiksi geneettisiä syitä ja ympäristötekijöitä. Nykyisellä lääkehoidolla voidaan lievittää sairauden oireita, mutta sen etenemistä ei pystytä pysäyttämään tai hidastamaan. Parkinsonin tautia sairastavien potilaiden aivoista on tutkimuksissa löydetty epänormaaleja proteiinikertymiä, joita kutsutaan Lewyn kappaleiksi. Lewyn kappaleet muodostuvat pääasiassa liukenemattomasta α-synukleiini-proteiinista. Normaalisti α-synukleiini on hermosoluissa liuenneessa muodossa, mutta sillä on taipumus muodostaa sakkautumia, jotka kertyvät hermosoluihin. Proteiinikertymien synty on yhdistetty hermosolun toiminnan häiriintymiseen sekä solukuolemaan. Parkinsonin taudin lisäksi α-synukleiinikertymiä esiintyy myös eräissä muissa aivosairauksissa, joita kutsutaan α-synukleinopatioiksi. Proteiinikertymien syntyyn vaikuttavia tekijöitä ja yhdisteitä on tämän vuoksi tutkittu yhtenä keinona vaikuttaa Parkinsonin taudin etenemiseen. Tämän väitöskirjatutkimuksen tarkoituksena oli tutkia α-synukleiinin kertymiseen liitetyn entsyymin, prolyylioligopeptidaasin (PREP) ja sen farmakologisen estäjän vaikutuksia kertymisprosessiin. Puhdistettuja proteiineja sekä solumalleja käyttäen PREP:n ja α-synukleiinin välillä osoitettiin olevan suora vuorovaikutus. PREP lisäsi α-synukleiinin kertymämuotojen syntymistä, ja PREP-estäjä KYP-2047 vähensi sitä. KYP-2047-hoidon vaikutuksia tutkittiin myös kahdessa hiirimallissa, joiden käyttökelpoisuutta Parkinsonin taudin malleina myös arvioitiin. Geneettisessä mallissa hiirillä oli Parkinsonin taudille altistava α-synukleiini-geenin mutaatio (A30P). Hiirillä ei todettu Parkinsonin taudille tyypillisiä aivo- ja käytösmuutoksia, mutta A30P-α-synukleiiniä kertyi aivoihin normaalia muotoa enemmän. KYP-2047 vähensi hiirimallissa tätä α-synukleiinin kertymämuotoa. Solukokeissa KYP-2047-hoidon näytettiin lisäävän autofagisen, proteiineja solussa pilkkovan järjestelmän toimintaa, mikä selittää α-synukleiinin vähentynyttä määrää. Toinen hiirimalli perustui aivoihin ruiskutettuun, proteiinien pilkkomisjärjestelmän toimintaa estävään laktakystiiniin. Proteasomiestäjä laktakystiini aiheutti hiirimallissa Parkinsonin taudin kaltaisia aivomuutoksia. Tässä mallissa KYP-2047 vaikutti positiivisesti motoriikkaa mittaavissa käytöskokeissa sekä suojasi osittain dopamiinia tuottavia hermosoluja mustatumakkeen alueella. Tulosten perusteella PREP-estäjä vaikuttaa α-synukleiinin kertymiseen vähentämällä PREP:n aikaansaamaa α-synukleiinin kertymämuotojen syntymistä ja lisäämällä α-synukleiinin hajotusta soluissa. PREP-estäjien mahdollisuuksia potentiaalisena keinona Parkinsonin taudin etenemisen hidastamiseksi ja muissa proteiininkertymäsairauksissa tulisi edelleen selvittää.
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- 2015
14. Prolyl Oligopeptidase Regulates Dopamine Transporter Phosphorylation in the Nigrostriatal Pathway of Mouse
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Julku, Ulrika H, primary, Panhelainen, Anne E, additional, Tiilikainen, Saija E, additional, Svarcbahs, Reinis, additional, Tammimäki, Anne E, additional, Piepponen, T Petteri, additional, Savolainen, Mari H, additional, and Myöhänen, Timo T, additional
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- 2016
- Full Text
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15. The Effects of Prolyl Oligopeptidase Inhibition in α-Synuclein Based Mouse Models of Parkinson's Disease
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Helsingin yliopisto, farmasian tiedekunta, Helsingfors universitet, farmaceutiska fakulteten, University of Helsinki, Faculty of Pharmacy, Division of Pharmacology and pharmacotherapy, Savolainen, Mari, Helsingin yliopisto, farmasian tiedekunta, Helsingfors universitet, farmaceutiska fakulteten, University of Helsinki, Faculty of Pharmacy, Division of Pharmacology and pharmacotherapy, and Savolainen, Mari
- Abstract
Parkinson's disease (PD) is characterized by a slow and gradual loss of neurons and subsequent loss of neurotransmitter dopamine in the movement-related nigrostriatal brain tracts. This causes symptoms of PD, which are resting tremor, rigidity and slowness of movement. Genetic and environmental factors are linked to PD, but its etiology is still largely unknown. Current drug therapies can only relieve the symptoms of PD but treatment to stop or delay the disease progression does not exist at the moment. The main findings in neuropathological characterization of the brain regions that are influenced in PD, are abnormal intraneuronal protein inclusions, called Lewy bodies. Insoluble, aggregated α-synuclein (aSyn) protein is the most abundant component of Lewy bodies. Pathological aggregation and accumulation of aSyn is associated with neuronal death in PD. Therefore, approaches to target aSyn as a potential disease-modifying treatment for PD have been under investigation. The aim of this study was to examine the role of prolyl oligopeptidase (PREP) and pharmacological inhibition of its enzymatic activity by KYP-2047 in aSyn aggregation. Using purified proteins and cell culture model, we showed that PREP forms direct protein-protein interaction with aSyn, thus enhancing its aggregation. KYP-2047 reduced the PREP-mediated aSyn aggregation in cell culture. Then the effects of PREP inhibition on aSyn aggregation were examined in vivo. The purpose was to first characterize a genetic mouse model, carrying mouse A30P mutated aSyn, which is linked to early-onset PD in humans, in order to find out if the mutated mouse aSyn is more prone to aggregate; and to cause PD-like phenotype. The effects of KYP-2047 treatments were assessed in the model. The main findings were that the A30P mutation in mouse aSyn protein caused minor hyperactive behaviour but did not change the brain dopamine levels, and A30P aSyn accumulated in the brain more than wildtype aSyn by age. KYP-2047 treatmen, Parkinsonin tauti on aivoja rappeuttava sairaus, jota sairastaa keskimäärin prosentti yli 60-vuotiaista. Taudissa mustatumakkeeksi kutsutun aivoalueen dopamiini-välittäjäainetta tuottavat hermosolut tuhoutuvat hitaasti. Dopamiini on tärkeä välittäjäaine liikettä säätelevällä hermoradalla, ja sen vähentyminen saa aikaan Parkinsonin taudille tyypillistä lepovapinaa, lihasten jäykkyyttä ja liikkeiden hitautta. Parkinsonin taudin synty on suurelta osin tuntematon, mutta siihen on liitetty esimerkiksi geneettisiä syitä ja ympäristötekijöitä. Nykyisellä lääkehoidolla voidaan lievittää sairauden oireita, mutta sen etenemistä ei pystytä pysäyttämään tai hidastamaan. Parkinsonin tautia sairastavien potilaiden aivoista on tutkimuksissa löydetty epänormaaleja proteiinikertymiä, joita kutsutaan Lewyn kappaleiksi. Lewyn kappaleet muodostuvat pääasiassa liukenemattomasta α-synukleiini-proteiinista. Normaalisti α-synukleiini on hermosoluissa liuenneessa muodossa, mutta sillä on taipumus muodostaa sakkautumia, jotka kertyvät hermosoluihin. Proteiinikertymien synty on yhdistetty hermosolun toiminnan häiriintymiseen sekä solukuolemaan. Parkinsonin taudin lisäksi α-synukleiinikertymiä esiintyy myös eräissä muissa aivosairauksissa, joita kutsutaan α-synukleinopatioiksi. Proteiinikertymien syntyyn vaikuttavia tekijöitä ja yhdisteitä on tämän vuoksi tutkittu yhtenä keinona vaikuttaa Parkinsonin taudin etenemiseen. Tämän väitöskirjatutkimuksen tarkoituksena oli tutkia α-synukleiinin kertymiseen liitetyn entsyymin, prolyylioligopeptidaasin (PREP) ja sen farmakologisen estäjän vaikutuksia kertymisprosessiin. Puhdistettuja proteiineja sekä solumalleja käyttäen PREP:n ja α-synukleiinin välillä osoitettiin olevan suora vuorovaikutus. PREP lisäsi α-synukleiinin kertymämuotojen syntymistä, ja PREP-estäjä KYP-2047 vähensi sitä. KYP-2047-hoidon vaikutuksia tutkittiin myös kahdessa hiirimallissa, joiden käyttökelpoisuutta Parkinsonin taudin malleina myös arvioitiin. Geneettisessä mallissa hiirillä
- Published
- 2015
16. Prolyl Oligopeptidase Enhances α-Synuclein Dimerization via Direct Protein-Protein Interaction
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Savolainen, Mari H., primary, Yan, Xu, additional, Myöhänen, Timo T., additional, and Huttunen, Henri J., additional
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- 2015
- Full Text
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17. The beneficial effect of a prolyl oligopeptidase inhibitor, KYP-2047, on alpha-synuclein clearance and autophagy in A30P transgenic mouse
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Savolainen, Mari H., primary, Richie, Christopher T., additional, Harvey, Brandon K., additional, Männistö, Pekka T., additional, Maguire-Zeiss, Kathleen A., additional, and Myöhänen, Timo T., additional
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- 2014
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18. Nikotiinireseptoreiden kautta vaikuttavat lääkeaineet nikotiiniriippuvuuden ja neurologisten sairauksien hoidossa
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Helsingin yliopisto, Farmasian tiedekunta, Savolainen, Mari, Helsingin yliopisto, Farmasian tiedekunta, and Savolainen, Mari
- Abstract
Neuronaaliset nikotiinireseptorit liittyvät tupakkariippuvuuden lisäksi moniin neurologisiin sairauksiin, kuten Alzheimerin tautiin, skitsofreniaan, masennukseen ja tarkkaavaisuus- ja ylivilkkaushäiriöön. Nikotiinireseptorien stimulaation on tutkimuksissa havaittu parantavan kognitiota. Useat lääkeyritykset tutkivat nikotiinireseptoriagonisteja ja -antagonisteja eri neurologisten sairauksien hoidossa. Ongelmana nikotiinireseptori-agonisteja käytettäessä on reseptorissa tapahtuva desensitisaatio. Tällöin reseptori sulkeutuu, eikä aktivoidu vaikka agonistia olisi tarjolla tai sitoutuneena reseptoriin. Varsinkin alfa7-reseptori desensitoituu hyvin nopeasti agonistialtistuksen seurauksena. Reseptorien desensitoituminen voi kliinisessä käytössä aiheuttaa lääkeaineen tehon menetyksen. Perinteisen agonistin sitoutumiskohdan lisäksi nikotiinireseptorissa sijaitsee myös muita sitoutumiskohtia, joita kutsutaan allosteerisiksi sitoutumispaikoiksi. Tutkimuksissa on havaittu, että eräät allosteerisesti sitoutuvat aineet, kuten PNU-120596, voivat vahvistaa agonistin aikaansaamaa vastetta ja/tai estää reseptorin desensitoitumista. Näitä aineita kutsutaan positiivisiksi allosteerisiksi modulaattoreiksi ja niiden ajatellaan olevan vaihtoehto desensitoitumisen aiheuttamaan tehon menetyksen ongelmaan. Nikotiinireseptorien positiivisten allosteeristen modulaattorien tarkkaa vaikutusta ja sitoutumiskohtaa reseptoriin ei vielä tarkkaan tiedetä. Tutkimuksen aiheena oli karakterisoida positiivisten allosteeristen modulaattoreiden vaikutuksia alfa7-nikotiinireseptoriin. Tutkimuksessa tarkoituksena oli käyttää hyväksi laboratoriossa aiemmin tehtyä havaintoa, jonka mukaan alfa7-nikotiinireseptorin transmembraaniosan aminohappoon tehdyn mutaation L247T seurauksena positiiviset allosteeriset modulaattorit muuttuvat agonisteiksi. Haluttiin selvittää, kuinka agonistin sitoutumiskohtaan kohdennettua mutageneesiä käyttäen tehty mutaatio W149M tai W149F vaikuttavat PNU-120596:n kykyyn toimia agonist, Neuronal nicotinic receptors are widely expressed throughout the brain and they facilitate fast synaptic neurotransmission. They are also involved in regulation of the release of other neurotransmitters like GABA, dopamine and glutamate. The most common subtypes are alfa4beta2 and alfa7 subunits containing receptors. Neuronal nicotinic receptors are involved in nicotine addiction but also in many neurological diseases like Alzheimer’s disease, schizophrenia, depression and attention deficit/hyperactivity disorder. The cholinergic stimulation enhances cognition in vivo and in human. There is not many drugs on the market that act via nicotinic receptors but many drug companies have new nicotinic agonists and antagonist under clinical research. When using nicotinic receptor agonists the problem is desensitization, which occurs in alfa7 nicotinic receptor rapidly after agonist exposure. When desensitized the receptor no longer responds to agonist even if it is there available to bind to receptor. The desensitization may lead to tachyphylaxis and losing of the clinical effect. Conventional agonists, like acetylcholine, bind to the binding site located in the extracellular part on nicotinic receptor subunit. There is also some other binding sites, which are called allosteric binding sites. It has been found out, that allosterically binding ligands, for example PNU-120596, can cause potentiation of agonist induced responses and/or prevent desensitization of receptor. These kinds of agents are called positive allosteric modulators and they are considered to be a new therapeutic option for CNS diseases containing cholinergic deficits. The mechanism of action of positive allosteric modulators is so far unclear. The purpose of my study was to characterize positive allosteric modulators on alfa7 nicotinic receptor. It had been found out earlier in the Millar laboratory that mutation L247T in the transmembrane domain converts positive allosteric modulators to agonists. The aim w
- Published
- 2011
19. Do financial statement adjustments matter in credit analysis? Evidence from the global telecommunications industry
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Kauppakorkeakoulu, School of Economics, Department of Accounting and Finance, Laskentatoimen ja rahoituksen laitos, Savolainen, Mari, Kauppakorkeakoulu, School of Economics, Department of Accounting and Finance, Laskentatoimen ja rahoituksen laitos, and Savolainen, Mari
- Abstract
This thesis investigates whether financial statement adjustments made during the rating process matter in credit analysis. Firstly, the thesis investigates whether reporting standards and company-specific factors are associated with financial statement adjustments. Secondly, the thesis examines whether financial statement adjustments are associated with actual credit ratings. The data used in the analyses is provided by one of the largest credit rating agencies, referred to as Credit Rating Agency X. The main data consists of the time period 2004-2007, including 196 companies reporting under US GAAP, IFRS and local GAAPs. Moreover, the IFRS companies included in the main data are analyzed more thoroughly in terms of the adjustment type, using the second set of data from year 2007. The data only includes companies active in the telecommunications industry. The first part of the empirical analyses aims at explaining financial statement adjustments using a linear regression method. The second part, on the other hand, includes credit rating models estimated also with a linear regression method. The adjustment variables are added one at a time in the rating models in order to investigate the association between financial statement adjustments and ratings. In an additional test, the explanatory powers resulting from reported and adjusted data are compared. First, the evidence suggests that capital intensity, operative risk and leverage are important in explaining financial statement adjustments. Additionally, public companies face fewer adjustments relative to private companies. The ultimate underlying reason for financial statement adjustments seems to be company-specific decisions concerning financing and capital structure as well as contractual matters. Second, the evidence demonstrates that, without any adjustments, credit ratings are higher for companies reporting under IFRS relative to companies reporting under US GAAP. However, adjustments increase ratings for US c
- Published
- 2009
20. D.2 - LACTACYSTIN INDUCES NIGROSTRIATAL DAMAGE AND MOTOR DEFICIT IN AGED A30P ALPHA-SYNUCLEIN TRANSGENIC AND WILDTYPE MICE
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Savolainen, Mari, primary, Albert, Katrina, additional, Männistö, Pekka, additional, Airavaara, Mikko, additional, and Myöhänen, Timo, additional
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- 2013
- Full Text
- View/download PDF
21. Hypothalamic prolyl endopeptidase (PREP) regulates pancreatic insulin and glucagon secretion in mice.
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Jung Dae Kim, Toda, Chitoku, D'Agostino, Giuseppe, Zeiss, Caroline J., DiLeone, Ralph J., Elsworth, John D., Kibbey, Richard G., Chane, Owen, Harvey, Brandon K., Richie, Christopher T., Savolainen, Mari, Myohannen, Timo, Jin Kwon Jeong, and Diano, Sabrina
- Subjects
ENDOPEPTIDASES ,CELLULAR control mechanisms ,INSULIN ,GLUCAGON ,NEURAL circuitry ,LABORATORY mice - Abstract
Prolyl endopeptidase (PREP) has been implicated in neuronal functions. Here we report that hypothalamic PREP is predominantly expressed in the ventromedial nucleus (VMH), where it regulates glucose-induced neuronal activation. PREP knockdown mice (Prep
gt/gt ) exhibited glucose intolerance, decreased fasting insulin, increased fasting glucagon levels, and reduced glucose-induced insulin secretion compared with wild-type controls. Consistent with this, central infusion of a specific PREP inhibitor, S17092, impaired glucose tolerance and decreased insulin levels in wild-type mice. Arguing further for a central mode of action of PREP, isolated pancreatic islets showed no difference in glucose-induced insulin release between Prepgt/gt and wild-type mice. Furthermore, hyperinsulinemic euglycemic clamp studies showed no difference between Prepgt/gt and wild-type control mice. Central PREP regulation of insulin and glucagon secretion appears to be mediated by the autonomic nervous system because Prepgt/gt mice have elevated sympathetic outflow and norepinephrine levels in the pancreas, and propranolol treatment reversed glucose intolerance in these mice. Finally, re-expression of PREP by bilateral VMH injection of adeno-associated virus-PREP reversed the glucose-intolerant phenotype of the Prepgt/gt mice. Taken together, our results unmask a previously unknown player in central regulation of glucose metabolism and pancreatic function. [ABSTRACT FROM AUTHOR]- Published
- 2014
- Full Text
- View/download PDF
22. Hypothalamic prolyl endopeptidase (PREP) regulates pancreatic insulin and glucagon secretion in mice
- Author
-
Jin Kwon Jeong, Jung Dae Kim, Mari Savolainen, Ralph J. DiLeone, Giuseppe D'Agostino, John D. Elsworth, Caroline J. Zeiss, Sabrina Diano, Timo T. Myöhänen, Owen Chan, Richard G. Kibbey, Chitoku Toda, Brandon K. Harvey, Christopher T. Richie, Kim, Jung Dae, Toda, Chitoku, D'Agostino, Giuseppe, Zeiss, Caroline J, Dileone, Ralph J, Elsworth, John D, Kibbey, Richard G, Chan, Owen, Harvey, Brandon K, Richie, Christopher T, Savolainen, Mari, Myöhänen, Timo, Jeong, Jin Kwon, and Diano, Sabrina
- Subjects
Blood Glucose ,Male ,Indoles ,medicine.medical_treatment ,Gene Expression ,Ion Channels ,Impaired glucose tolerance ,Mice ,0302 clinical medicine ,Ion Channel ,Insulin Secretion ,Hypothalamu ,Pancrea ,Insulin ,Thiazolidine ,Phosphorylation ,Uncoupling Protein 1 ,0303 health sciences ,Multidisciplinary ,Serine Endopeptidases ,Glucagon secretion ,Glucose clamp technique ,Recombinant Protein ,Biological Sciences ,Recombinant Proteins ,3. Good health ,Serine Endopeptidase ,peripheral hormonal regulation ,medicine.anatomical_structure ,Gene Knockdown Techniques ,Thiazolidines ,Serine Proteinase Inhibitor ,Prolyl Oligopeptidases ,medicine.drug ,medicine.medical_specialty ,Serine Proteinase Inhibitors ,Hypothalamus ,Mice, Transgenic ,Carbohydrate metabolism ,Biology ,Glucagon ,Mitochondrial Proteins ,03 medical and health sciences ,central glucose sensing ,Prolyl endopeptidase ,Internal medicine ,Glucose Intolerance ,medicine ,Mitochondrial Protein ,Animals ,Pancreas ,030304 developmental biology ,sympathetic nervous system ,Animal ,Pancreatic islets ,medicine.disease ,Receptor, Insulin ,Endocrinology ,Indole ,Ventromedial Hypothalamic Nucleus ,Gene Knockdown Technique ,Glucose Clamp Technique ,030217 neurology & neurosurgery - Abstract
Prolyl endopeptidase (PREP) has been implicated in neuronal functions. Here we report that hypothalamic PREP is predominantly expressed in the ventromedial nucleus (VMH), where it regulates glucose-induced neuronal activation. PREP knockdown mice (Prep(gt/gt)) exhibited glucose intolerance, decreased fasting insulin, increased fasting glucagon levels, and reduced glucose-induced insulin secretion compared with wild-type controls. Consistent with this, central infusion of a specific PREP inhibitor, S17092, impaired glucose tolerance and decreased insulin levels in wild-type mice. Arguing further for a central mode of action of PREP, isolated pancreatic islets showed no difference in glucose-induced insulin release between Prep(gt/gt) and wild-type mice. Furthermore, hyperinsulinemic euglycemic clamp studies showed no difference between Prep(gt/gt) and wild-type control mice. Central PREP regulation of insulin and glucagon secretion appears to be mediated by the autonomic nervous system because Prep(gt/gt) mice have elevated sympathetic outflow and norepinephrine levels in the pancreas, and propranolol treatment reversed glucose intolerance in these mice. Finally, re-expression of PREP by bilateral VMH injection of adeno-associated virus-PREP reversed the glucose-intolerant phenotype of the Prep(gt/gt) mice. Taken together, our results unmask a previously unknown player in central regulation of glucose metabolism and pancreatic function.
- Published
- 2014
23. Disease Modification Through Trophic Factor Delivery.
- Author
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Savolainen M, Emerich D, and Kordower JH
- Subjects
- Animals, Cell Engineering methods, Corpus Striatum cytology, Corpus Striatum metabolism, Disease Models, Animal, Drug Delivery Systems methods, Genetic Therapy instrumentation, Genetic Therapy trends, Genetic Vectors genetics, Humans, Huntingtin Protein genetics, Huntingtin Protein metabolism, Huntington Disease genetics, Huntington Disease pathology, Macaca fascicularis, Mice, Nerve Growth Factors administration & dosage, Neurons metabolism, Neurons pathology, Rats, Stereotaxic Techniques instrumentation, Corpus Striatum pathology, Genetic Therapy methods, Genetic Vectors administration & dosage, Huntington Disease therapy, Nerve Growth Factors genetics
- Abstract
Huntington's disease (HD) is characterized by a significant loss of striatal neurons that project to the globus pallidus and substantia nigra, together with loss of cortical projection neurons in varying regions. Mutant huntingtin is suggested to drive the pathogenesis partially by downregulating corticostriatal brain-derived neurotrophic factor (BDNF) levels and signaling. Neurotrophic factors are endogenous peptides that promote the survival and maintenance of neurons. BDNF and other neurotrophic factors have shown neuroprotective benefits in various animal models of neurodegeneration, and are interesting candidates to protect the cell populations that are destined to die in HD. In an attempt to enhance the delivery of neurotrophic factors, several methods have been established to deliver long-term neurotrophic factor gene therapy to human target tissues. This chapter discusses two alternative approaches that have been shown to have potential to deliver neurotrophic factors as a neuroprotective gene therapy for HD. The methods are (1) ex vivo approach where encapsulated cells engineered to express neurotrophic factor are inserted into brain parenchyma or ventricle, and (2) in vivo viral vector therapy, in which viral vector is injected into desired brain area to express gene of interest in the host cells.
- Published
- 2018
- Full Text
- View/download PDF
24. Agonist activation of alpha7 nicotinic acetylcholine receptors via an allosteric transmembrane site.
- Author
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Gill JK, Savolainen M, Young GT, Zwart R, Sher E, and Millar NS
- Subjects
- Acetylcholine, Aconitine analogs & derivatives, Allosteric Regulation physiology, Animals, Binding Sites genetics, Binding Sites physiology, Computer Simulation, Electrophysiology, Humans, Mice, Molecular Structure, Mutation, Missense genetics, Naphthalenes chemistry, Patch-Clamp Techniques, Quinolines chemistry, Receptors, Nicotinic chemistry, Receptors, Nicotinic genetics, Sulfonamides chemistry, Xenopus laevis, alpha7 Nicotinic Acetylcholine Receptor, Membrane Transport Modulators pharmacology, Models, Molecular, Nicotinic Agonists pharmacology, Receptors, Nicotinic metabolism
- Abstract
Conventional nicotinic acetylcholine receptor (nAChR) agonists, such as acetylcholine, act at an extracellular "orthosteric" binding site located at the interface between two adjacent subunits. Here, we present evidence of potent activation of α7 nAChRs via an allosteric transmembrane site. Previous studies have identified a series of nAChR-positive allosteric modulators (PAMs) that lack agonist activity but are able to potentiate responses to orthosteric agonists, such as acetylcholine. It has been shown, for example, that TQS acts as a conventional α7 nAChR PAM. In contrast, we have found that a compound with close chemical similarity to TQS (4BP-TQS) is a potent allosteric agonist of α7 nAChRs. Whereas the α7 nAChR antagonist metyllycaconitine acts competitively with conventional nicotinic agonists, metyllycaconitine is a noncompetitive antagonist of 4BP-TQS. Mutation of an amino acid (M253L), located in a transmembrane cavity that has been proposed as being the binding site for PAMs, completely blocks agonist activation by 4BP-TQS. In contrast, this mutation had no significant effect on agonist activation by acetylcholine. Conversely, mutation of an amino acid located within the known orthosteric binding site (W148F) has a profound effect on agonist potency of acetylcholine (resulting in a shift of ∼200-fold in the acetylcholine dose-response curve), but had little effect on the agonist dose-response curve for 4BP-TQS. Computer docking studies with an α7 homology model provides evidence that both TQS and 4BP-TQS bind within an intrasubunit transmembrane cavity. Taken together, these findings provide evidence that agonist activation of nAChRs can occur via an allosteric transmembrane site.
- Published
- 2011
- Full Text
- View/download PDF
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