36 research outputs found

    Novel insights into filopodia function – A focus on integrin and F-actin regulation

    Get PDF
    Filopodia are actin-rich cell protrusions that are extended from the plasma membrane by different cell types in order to sense the surrounding environment. In cancer cells, the emergence of filopodia supports metastasis, while in neuronal cells filopodia help to form synapses by probing adjacent cells for suitable presynaptic partners. Filopodia can make contact with the extracellular matrix with small, integrinmediated adhesions located at their tips. During cancer invasion, recognition of the extracellular matrix by filopodia not only supplies migrating cells with guidance cues but has also been linked with increased colony growth at the metastatic site. In neuronal cells, inhibition of integrin activity has been shown to negatively impact synapse formation. Although both filopodia and integrin-positive adhesions have roles in metastasis or in synaptogenesis, filopodial adhesions remain under-studied cellular structures and there exists minimal literature on how these adhesions are regulated or how they function. The objective of this study was to reveal novel regulatory mechanisms of filopodia by studying two integrin and filopodia linked proteins: myosin-X and SHANK3. The work presented here provides fundamental information on how 1) integrins are activated at filopodia tips, 2) which integrinlinked proteins are recruited to adhesions at filopodia providing a road-map to classify these adhesions and 3) how SHANK3, an F-actin network organizer and filopodia regulator, modulates the crosstalk between integrin and F-actin via direct and conformationally regulated binding with F-actin. The thesis also provides novel methodology in the form of a high-end biochemical binding assay (4) where protein binding to integrin tails can be interrogated in the presence of a lipidic membrane.Solun filopodien toiminta Filopodit ovat solukalvon pullistumia, joita täyttää sisältäpäin solun aktiinitukiranka. Filopodit syntyvät solukalvon pullistuessa ulospäin aktiinitukirangan vaikutuksesta ja solut käyttävät niitä ympäristönsä aistimiseen käyttämällä filopodien kärjissä sijaitsevia tarttumisreseptoreja - integriinejä. Syövän leviämisen aikana solujen kyky tunnistella ympäröivää soluväliainetta tarjoaa solulle tarkkaa tietoa sen ympäristöstä, ohjaten solun kulkua vaikeassa 3-ulotteisessa soluväliaineen verkostossa. Toisaalta hermosolut käyttävät filopodeja naapurisolujensa (tai ympäröivän kudoksen) tarkasteluun hermoliitosten muodostusprosessissa. Vaikka filopodit ja integriinireseptorit ohjaavat sekä syövän leviämistä ja aivojen normaalia toimintaa, filopodien välittämien integriini-positiivisten soluadheesioiden synty tunnetaan huonosti. Lisäksi filopodien soluadheesioiden säätely sekä vaikutukset solun toiminnalle ovat heikosti ymmärrettyjä tapahtumasarjoja. Tämän väitöskirjatyön tarkoituksena oli ymmärtää filopodien solullisia säätelyketjuja paremmin tutkimalla kahta integriineihin ja filopodeihin aiemmin liitettyä proteiinia: myosiini-X ja SHANK3. Tässä väitöskirjatyössä esitetyt tulokset tuovat täysin uutta tietoa seuraavista tapahtumista: 1) miten filopodit muodostavat adheesioita soluväliaineen kanssa 2) mitkä solun adheesioproteiinit sijoittuvat filopodien kärkiin adheesiomuodostusprosessin aikana sekä 3) kuinka SHANK3 proteiini säätelee samanaikaisesti solun aktiinitukirankaa ja integriiniaktiivisuutta. Lisäksi väitöskirja sisältää menetelmällisen julkaisun uudesta biokemiallisesta koeasetelmasta, jonka avulla voidaan paremmin tutkia solun proteiinien sitoutumista integriinireseptoreihin solukalvon läheisyydessä.ei tietoa saavutettavuudest

    Myosin-X: A molecular motor driving cancer cell invasion

    No full text
    In metastasis migratory cancer cells invade through stroma and spread throughout the body forming metastatic colonies into distant organs. Myosin-X is a member of the vast myosin superfamily of actin dependent motor proteins. Functionally very different from myosin-II, myosin-X works by transporting intracellular cargo along actin filaments. Myosin-X is able to induce filopodia formation and can support their function by transporting cargo towards filopodia tips. Among the myosin-X cargo are the integrin family of transmembrane receptors that have been for long known to be crucial for cell motility. Whereas integrins have roots in many aspects of migratory processes, myosin-X expression has been shown to worsen patient prognosis and increase metastatic potential. By using standard and novel cytometric techniques, state-of-the-art microscopy techniques and biochemical tools this Pro gradu thesis addresses how myosin-X (MYO10) supports filopodia-linked cancer cell invasion that is detected in single and collective cell migration. Myosin-X expression was found to inhibit 51 integrin activation via its FERM domain in triple-negative breast carcinoma and osteosarcoma cell lines. In addition, myosin-X expression was seemed to support integrin trafficking in a p53 mutant cell line but not in p53 wild-types cells. Upon PH domain disruption, myosin-X was found to localize to subcellular compartments and to the cell periphery together with 1 integrin. In this case myosin-X was unable to inactivate 1 integrin, perhaps due to loss of a direct interaction. However, PH domain deficient myosin-X lowers total 1 integrin levels at the plasma membrane. In total, data from experiments on myosin-X with disrupted or missing PH domain suggest a common route of trafficking for these proteins. Structural bioinformatics, proximity ligation assay and a novel proteoliposomal binding assay were used to further assess the interaction between myosin-X and integrin. In the process, a previously unnoticed RA-like subdomain was discovered to be situated inside myosin-X FERM domain.Siirretty Doriast

    Matematiikka ja tilastolliset mallit syövän hoitovasteen ennustamisessa

    No full text
    Syöpäpotilaiden hoitovasteissa on usein yksilöllisiä eroja. Yksilölliset vaihtelut voivat johtaa vaikeisiin haittaoireisiin ilman havaittavaa syövän hoitovastetta, ja siksi potilaskohtaista lääkevastetta on oleellista pyrkiä ennustamaan potilaan syöpäkasvaimen biologisten ominaispiirteiden perusteella. Matemaattiset ja tilastolliset mallit tarjoavat monipuolisen valikoiman laskennallisia työkaluja, joiden ennusteellinen käyttö syöpädiagnostiikan rinnalla ja osana syövän hoitopolkua on keskeinen osa tulevaisuuden yksilöllistettyä lääketiedettä. Parhaimmillaan hoitovasteen ennustaminen vähentää turhia lääkehaittoja, auttaa potilaskohtaisesti ihanteellisen hoidon valinnassa ja vähentää kalliiden hoitokeinojen käyttöä tapauksissa, joissa potilas ei niistä merkittävästi hyödy. Vaikka kasvaimen ja potilaan yksilölliseen biologiaan pohjautuvia hoitovaste-ennusteita käytetään vielä verrattain vähän kliinisessä päätöksenteossa, tilanne todennäköisesti muuttuu seuraavien vuosien aikana.Peer reviewe

    The character and trends of extreme precipitation in Vidzeme region (1966-2010)

    No full text
    Bakalaura darbā „Ekstremālo nokrišņu raksturs un izmaiņu tendences Vidzemē (1966. -2010.)” ir veikta ekstremālo nokrišņu indeksu izmaiņu analīze Vidzemes reģionā. Darbā ir izpētītas un analizētas piecu ekstremālo nokrišņu indeksu vērtību – dienu skaita ar intensīviem nokrišņiem (R10mm), dienu skaita ar ļoti intensīviem nokrišņem (R20mm), mēreni mitro dienu (R75p), ļoti mitro dienu (R95p) un ekstremāli mitro dienu (R99p) izmaiņas laika periodā no 1966. līdz 2010.gadam. Pētījumā ir izmantotas sešas Vidzemes meteoroloģisko staciju (Ainaži, Alūksne, Priekuļi, Rīga – Universitāte, Rūjiena) ikdienas nokrišņu novērojumu datu rindas. Bakalaura darba apjoms ir 68 lappuses, tajā iekļautas 3 nodaļas un 9 apakšnodaļas. Darbu papildina 56 attēli un 8 tabulas, kā arī 5 pielikumi. Atslēgvārdi: ekstremālo nokrišņu indeksi, izmaiņas, dienu skaits, Vidzeme.The bachelor paper „The character and trends of extreme precipitation in Vidzeme region (1966-2010)” analyses the change of the extreme precipitation indices in Vidzeme region. The author has researched and analyzed the change of five extreme precipitation indices – heavy precipitation days (R10mm), very heavy precipitation days (R20mm), moderate wet days (R75p), very wet days (R95p) and extremely wet days (R99p) from 1966 to 2010. In this research are used daily precipitation data from 6 weather stations (Ainaži, Alūksne, Priekuļi, Rīga – Universitāte, Rūjiena) in Vidzeme region. Thee bachelor paper consists of 68 pages, witch includes 3 chapters and 9 subchapters. The paper is complemented by 56 figures, 9 tables and 5 annex. Key words: extreme precipitation indices, changes, number of days, Vidzeme region

    RepurposeDrugs : an interactive web-portal and predictive platform for repurposing mono- and combination therapies

    No full text
    RepurposeDrugs (https://repurposedrugs.org/) is a comprehensive web-portal that combines a unique drug indication database with a machine learning (ML) predictor to discover new drug-indication associations for approved as well as investigational mono and combination therapies. The platform provides detailed information on treatment status, disease indications and clinical trials across 25 indication categories, including neoplasms and cardiovascular conditions. The current version comprises 4314 compounds (approved, terminated or investigational) and 161 drug combinations linked to 1756 indications/conditions, totaling 28 148 drug–disease pairs. By leveraging data on both approved and failed indications, RepurposeDrugs provides ML-based predictions for the approval potential of new drug–disease indications, both for mono- and combinatorial therapies, demonstrating high predictive accuracy in cross-validation. The validity of the ML predictor is validated through a number of real-world case studies, demonstrating its predictive power to accurately identify repurposing candidates with a high likelihood of future approval. To our knowledge, RepurposeDrugs web-portal is the first integrative database and ML-based predictor for interactive exploration and prediction of both single-drug and combination approval likelihood across indications. Given its broad coverage of indication areas and therapeutic options, we expect it accelerates many future drug repurposing projects.Peer reviewe

    Theatre in the landscape as an intermediary of its meanings

    No full text
    Táto práca vzniká ako reakcia na proces tvorby absolventského projektu SOLE. Jej autorka čerpá z vlastnej skúsenosti divadelnej tvorby situovanej v prímestskej krajine Prahy. Zhromažďuje a interpretuje postupy tvorby a divácke zážitky a hľadá v nich momenty, ktoré jej pomáhajú spätne lepšie zhodnotiť jednotlivé inscenačné rozhodnutia. Môže divadlo pomáhať človeku pocítiť významy ukotvené v krajine? A akými prostriedkami to dosahuje?This thesis is a reaction to the creative process of the SOLE graduation project. Its author draws on her own experiences of theater creation situated in the suburban landscape of Prague. She takes into account and interprets the creative processes and the audience's experiences and looks for moments in them that help her to evaluate individual staging decisions in retrospect. Can theater help a person to feel the meanings anchored in the landscape? And by what means does it achieve this

    Filopodome Mapping Identifies p130Cas as a Mechanosensitive Regulator of Filopodia Stability

    Get PDF
    in filopodia tips, predicts critical roles for PIs in regulating filopodia ultra-structure and function. Our mapping further reveals that filopodia adhesions consist of a unique set of proteins, the filopodome, that are distinct from classical nascent adhesions, focal adhesions, and fibrillar adhesions. Using live imaging, we observe that filopodia adhesions can give rise to nascent adhesions, which, in turn, form focal adhesions. We demonstrate that p130Cas (BCAR1) is recruited to filopodia tips via its C-terminal Cas family homology domain (CCHD) and acts as a mechanosensitive regulator of filopodia stability. Finally, we demonstrate that our map based on myosin-X-induced filopodia can be translated to endogenous filopodia and fascin- and IRSp53-mediated filopodia

    Perlindungan Hukum Hak-Hak Narapidana Lansia: Studi Kasus Pada Lembaga Pemasyarakatan Kelas II B Sumedang

    Get PDF
    Correctional Institution is a place to conduct training on inmates and correctional students in Indonesia. Before it was known as Penitentiary in Indonesia, it was known as prison. As for the formulation of the problem that the author presents, namely; (1) How the training program is carried out for elderly inmates. (2) Any factors that are inhibited in the application of the rights of elderly inmates in Sumedang Class IIB Penitentiary. This research uses qualitative research methods that use qualitative methods that are descriptive. Data retrieval uses literature study techniques and field studies. This research was conducted at The Sumedang Class IIB Penitentiary located around Sumedang square. The results of research in the field obtained that in lapas accommodate 256 out of a capacity of 100 with a classification of 195 adult inmates, 61 prisoners, 2 female inmates, and 2 elderly inmates. Special treatment is only given to inmates with the elderly category because they already do not have enough ability to perform all activities, as well as the placement of rooms and toilets designed to facilitate them. In addition, spiritual development continues to be carried out and one of the mandatory activities for elderly inmates carried out every day and the separation of residential blocks of elderly inmates is also one of the special treatment given to elderly inmates who do need special treatment and attention

    ScType enables fast and accurate cell type identification from spatial transcriptomics data

    No full text
    The limited resolution of spatial transcriptomics (ST) assays in the past has led to the development of cell type annotation methods that separate the convolved signal based on available external atlas data. In light of the rapidly increasing resolution of the ST assay technologies, we made available and investigated the performance of a deconvolution-free marker-based cell annotation method called scType. In contrast to existing methods, the spatial application of scType does not require computationally strenuous deconvolution, nor large single-cell reference atlases. We show that scType enables ultra-fast and accurate identification of abundant cell types from ST data, especially when a large enough panel of genes is detected. Examples of such assays are Visium and Slide-seq, which currently offer the best trade-off between high resolution and number of genes detected by the assay for cell type annotation.Peer reviewe
    corecore