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(2023)Human induced pluripotent stem cells (hiPSCs) are derived from adult differentiated somatic cells and reprogrammed to an embryonic-like state. Pluripotent stem cells can be differentiated into almost any somatic cell type by using directed differentiation methods, but the differentiation efficiency often varies depending on the cell type. hiPSCs and cells differentiated from them can be used as a disease model carrying the patient’s phenotype and genotype. Amyotrophic lateral sclerosis (ALS) is a progressive motor neuron disease where both upper and lower motor neurons degenerate, leading to paralysis. There is no curative treatment for ALS, and it leads to the death of the patient in 3 to 5 years on average from the first symptoms. The most common genetic cause of familial ALS is a hexanucleotide repeat expansion in C9orf72-gene. ALS pathology is strongly linked to endoplasmic reticulum (ER) stress, which affects cell homeostasis and proteostasis, and leads to apoptosis when prolonged. The primary aim of this research is to characterize the differentiation of four hiPSCs lines towards lower motor neurons and to study the neuroprotective effects of cerebral dopamine neurotrophic factor (CDNF) and CDNF-derived peptide on ER stress and cell viability. This experiment used two control cell lines from two healthy donors and two patient cell lines from two different ALS patients carrying the C9orf72-mutation. To evaluate the efficiency of the differentiation towards motor neurons, molecular markers for pluripotent and neural progenitor cells as well as for maturated motor neurons were analyzed. Relative gene expression levels were measured from weekly time points with qPCR. Immunocytochemical (ICC) antibody staining was performed during differentiation. Endogenic CDNF levels were analyzed from differentiating cells at weekly time points and the effect of CDNF on Thapsigargin (TG) -induced ER stress in motor neurons was analyzed. In addition, cell viability was analyzed in TG-CDNF treatment. All pluripotent and progenitor markers were downregulated in differentiated cells, and the expression of the mature motor neuron markers was upregulated. Mature motor neuron markers were also expressed at the protein level. The endogenous CDNF levels were highest at the progenitor cell stage. The ER stress response was upregulated in TG-treated cells, and there were no differences between treatments against ER stress. Furthermore, TG and growth factor treatments differentially affected the viability of the control and patient cell lines. Treatment decreased viability in control cell lines and increased viability in patient cell lines. Pluripotent stem cells were successfully differentiated toward motor neurons. The differentiation was performed twice, and the results were similar on both individual biological repeats. Analysis of endogenous CDNF expression levels was performed for the first time on hiPSCs lines. In this study, CDNF or its derivate didn’t reduce ER stress but it influenced cell viability, especially in patient cell lines with growth factor treatment. In the future, TG-treatment could be optimized regarding timing and growth factor treatment, or the toxin could be changed to another ER-stress inducing toxin. In addition, the C9orf72 pathology should be identified in order to use differentiated motor neurons as a pre-clinical disease model.
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(2020)Calsyntenin-3 is a type I transmembrane protein, that is mainly expressed on the post-synaptic cell membranes. It belongs to the calsyntenin family that is part of the cadherin superfamily. Calsyntenin-3 consists of a cytosolic C-terminal region, a transmembrane domain and an extracellular N-terminal part, that consists of a laminin G-like domain (LNS) and two cadherin domains (CAD). Calsyntenin-3 is mainly expressed in the brain, but it can also be found in the heart, liver, pancreas, lung, skeletal muscle and placenta. Calsyntenin-3 has an effect on neurogenesis by affecting the development of excitatory and inhibitory synapses. It might also play a role in Alzheimer’s disease, as it has been found to be able to bind β-amyloid peptide, that is known to play a key role in the development of Alzheimer’s disease. Calsyntenin-3 acts as a synaptic adhesion protein, that binds to the post-synaptic neurexins with its extracellular region. However, the previous studies have contradicting results regarding the calsyntenin-3 domains that mediate the interaction between the calsyntenin-3 and neurexins. There is also disagreement whether calsyntenin-3 binds neurexin-α, neurexin-β or both. Because of these discrepancies, the aim of this master’s thesis study was to produce the calsyntenin-3 ectodomain constructs that contained either the two CAD domains, the LNS domain or all three domains, using baculovirus mediated protein production in insect cell cultures. These purified protein constructs were meant to be used for the determination of the binding domains. Unfortunately, only the purification of the calsyntenin-3 LNS domain was successful and the purification of the constructs, containing the CAD domains, was unsuccessful. A SEC-MALLS experiment, that was performed for the calsyntenin-3 LNS domain, revealed that it forms dimers in a solution, which is consistent with experiments performed with the LNS domain of human sex hormone‐binding globulin. The second aim of this master’s thesis study was to express the calsyntenin-3 ectodomain constructs on the surface of HEK293T cells and to test the binding between calsyntenin-3 and neurexins in a cell surface binding assay. The results of the cell surface binding assay indicated that the binding is mediated by the calsyntenin-3 CAD domains and that calsyntenin-3 binds to neurexin-α, but the binding to neurexin-β was not detected. However, the results from the cell surface binding assay were conflicting: the binding between the calsyntenin-3 full ectodomain construct and neurexin-α was not detected, but the binding was detected between calsyntenin-3 CAD ectodomain construct and neurexin-α. Therefore, the cell surface binding assay cannot be considered entirely reliable and should be repeated before making further conclusions.
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(2022)Breeding-dispersal and philopatry are important life-history traits when it comes to the ecology of animals. A number of factors such as sex, age, habitat stability, population density, predation and various environmental factors influence the movement patterns of species. Philopatry, in general, can be used by organisms as a predator avoidance strategy and to improve feeding efficiency. Dispersal on the other hand has been shown to help avoid inbreeding and competition within groups or between kin. Among the different types of dispersal and philopatry, breeding dispersal and site fidelity to breeding sites have been studied in many vertebrates. Many birds and some ungulate species have been the focus of these studies and have shown that breeding success influences site fidelity. Among ungulates, the reindeer genus (Rangifer tarandus spp.) however, has received little attention for this topic. A species of special conservational value is the wild forest reindeer (Rangifer tarandus fennicus), which is a rare, and near-threatened subspecies of reindeer living in Finland. Knowledge of factors influencing the dispersal and site fidelity for this species is lacking but has important implications for the conservation and management of this and other vulnerable species. In my thesis I investigated the philopatry of wild forest reindeer females from eastern Finland and tested if the calving site fidelity was influenced by breeding success, predator pressure and the female’s age. Given the high densities of predators in the study area (Kainuu) and thus high predator pressure on reindeer, I expected (i) the philopatry of the wild forest reindeer female’s to be stronger in areas with higher predator pressure but (ii) higher dispersal movement when wild forest reindeer females had no breeding success the previous year. Additionally, I expected (iii) the dispersal distances of wild forest reindeer females to be negatively correlated with their age. For this study I used long-term GPS monitoring data of 53 collared wild forest reindeer females, which were followed for varying periods (2-6 years) between 2010-2021 from Eastern Finland. I found that the inter-year distances between calving sites per female had a median distance of 2.84 km, confirming that female wild forest reindeer show philopatry to calving sites, as do other reindeer subspecies. Even though the movement ranged from 4.8 m to 36.99 km, showing substantially longer dispersal for some individuals. The model outcomes indicate some association between predation pressure and site fidelity, and reduced philopatry following calf mortality, although none of these associations were significant. The age of the mother did also not show any significant influence on a female’s site fidelity. Nonetheless, these results would suggest that a mother's choice to leave or return to the same calving site might be influenced by the previous year's calf mortality but more complex variables like anthropogenic disturbances, environmental factors, as well as intrinsic factors and the physical condition of the mother most likely also play a role in this.
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(2019)The consumption of omega (n-) 3 polyunsaturated fatty acids (PUFA) from fish has been associated with lower rates of cardiovascular diseases with one mechanism being lowering LDL cholesterol levels in blood. When incorporated into LDL particle n-3 PUFAs can modify the lipid composition and reduce atherogenicity of the particle, e.g. by influencing inflammatory processes. The effects of n-3 PUFA of plant origin are less studied. This study investigated the effects of Camelina sativa oil (CSO), a rich source of alpha-linolenic acid (ALA), on lipid species of human LDL including phosphatidylcholines (PC), lysophosphatidylcholines (LPC), sphingomyelin (SM), triacylglycerols (TAG) and cholesterol esters (CE). A total of 38 subjects with a history of impaired fasting glucose, were randomly divided into two groups; CSO (ALA 10 g/day) and the control group (limited fish and ALA intake) for 12 weeks. Blood samples were collected from the subjects at the beginning and at the end of the experiment after 12 weeks. LDL particles were isolated from blood and the lipids were analyzed by mass spectrometry. The CSO affected more the LDL core lipids (TAG and CE) than lipid species of the shell (PC, LPC, SM). CSO is high in ALA and linoleic acid (LA). Thus, the diet reduced mole fractions of lipid species containing saturated acyl chains while acyl chains in the core lipids with ALA, LA and EPA, that is formed in the body from ALA, were increased. Based on the results, having CSO in the diet changed the LDL particle lipid composition in a favorable direction for cardiovascular health.
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Carbon capture and sequestration : the portrayal of risks in newspaper media in Finland and Norway (2012)Carbon capture and storage may become an inevitable means in mitigating climate change. However, it is a new technology involving a great deal of uncertainties. It is of utmost importance to understand on one hand, the risks caused by the technology and on the other, what is holding it back. This way unforeseen setbacks and environmental or other damage could be avoided. This thesis is a part of a wider research project on the risk governance of carbon dioxide capture and storage (RICCS). The present study gives additional insights to CCS risk analysis by diving into the stories that the media tells about the risks. I analyze the media coverage on the risks of CCS in the most wide spread newspapers of Norway and Finland with the aim of identifying what kind of risk framings are portrayed by the media; how strong is the presence of uncertainties and what kind of uncertainties are brought up. The media is seen as a mirror of public perception, but also one of the players influencing it. The possible effects that the analyzed articles could have on public perception of risks are discussed. The theoretical framework consists of theories of systemic risks, narrative policy analysis and framing of environmental risks in the media. I describe the nature of systemic risks. Then I move on to framing, more specifically how environmental risks are framed in the media and how it can effect public perception. After this I explain how narrative analysis can be used as a tool for identifying framings. Then I describe Klinke and Renn's Prometheus theory that I will use for analyzing the level of uncertainty in the framing of the articles and for discussing the implications of my findings. The results show that the risks caused by CCS are mainly the lock-in in fossil fuels, it's possible negative effect on developing renewable energy and environmental and health risks in general. The risks towards successful CCS seem to be mainly connected to funding, which connects to emissions' prices, the climate agreement and viability of investments. The differences between the two countries are quite related to the situation in which each country is in terms of CCS development. Norway is very active and pushing CCS forward. Consequently, the Norwegian articles are generally not very critical of the technology itself, but discuss what is holding it back. Generally, the Finnish articles bring out more aspects on the issue, both positive and negative, leaving quite an ambiguous image to the reader. The implications of my findings for future policy practices are quite extensive and therefore not very useful, since most policy recommendations seem more or less relevant. What is interesting though, is that based on my findings I could identify the turning points in which public perception is most relevant. These are: What kind of energy production is supported? Is CCS an acceptable mitigation means? Is the risk of leakage taken as severe? These issues represent turning points for the future of CCS technology and deliberative processes can be crucial when discussing them.
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(2014)Lakes play an important role in both global and regional carbon cycling, especially, the role of lakes is pronounced in the boreal zone, where lakes cover up to 20% of the land area. Allochthonous carbon is discharged mainly from terrestrial processes, but also through anthropogenic eutrophication. The role of allochthonous carbon load in lacustrine ecosystems is important, which can have far-reaching effects on lacustrine biogeochemistry in general and especially on carbon cycling. Part of dissolved organic carbon is transformed to carbon dioxide (CO2) and methane (CH4) in biological processes that result in carbon gas concentrations in water that increase above atmospheric equilibrium, thus making boreal lakes serve as sources of the important greenhouse gases. Lake Vesijärvi is renowned for its clear-water, but it has suffered eutrophication for a long history. The severely affected Enonslkä lake basin is the most eutrophic part since it surrounded mainly by urban area (28%) and forests (31%). To improve the water quality, large scale aeration in the autumn 2009 was started with the Mixox-oxygenerators. Aeration is used to weaken thermal stratification and recharge oxygen by increasing vertical flow circulation within the water columns. This leads to most chemical cocnetrations become more homogenous with depth and concentrations of reduced forms decrease in the hypolimnion. The aeration units were operated on campaign basis in summer 2013. One aim here was to investigate carbon gas concentrations and fluxes from the urban boreal lake basin, and examine the impacts of artificial aeration on greenhouse gases during the open water period in 2013. Besides CO2 and CH4 concentrations and fluxes, I measured also the water temperature and dissolved oxygen concentration of the water columns for monitoring the efficiency of artificial aeration. All gas samples were analyzed at the Lammi Biological Station of University of Helsinki with gas chromatography using the head space technique. As background data I used the information on temperature and oxygen profiles collected from the measuring platform on Lake Vesijärvi, and a reference study on CO2 and CH4 concentrations and fluxes dating back to 2005 when there was no aeration going on. In 2013, the studied lake basin was a source of CO2 to the atmosphere during the open water period, although the lake basin showed uptake of CO2 from the atmosphere for short times. The lake acted as a steady source of CH4 to the atmosphere throughout the measuring period. The mean CO2 flux was 34.1 mmol m-2 d-1, which was over 2.5 times higher than in the reference year 2005 when there was no the aeration yet. During the campaigns, the CO2 fluxes were higher from aerated than non-aerated water column and from the longer aerations as well. Therefore, aeration mixed stratified water columns and thus enhanced release of gases such as CO2 from surface water to the atmosphere. The mean CH4 flux was 0.2 mmol m-2 d-1. The CH4 fluxes from the Enonselkä basin were slightly decreased in 2013. These decreased CH4 fluxes in Enonselkä basin can be attributed to the limited CH4 production and high rate of CH4 oxidation in the oxygenated hypolimnion and surface of sediment. The daily CH4 fluxes fluxes during the long time aerated operations decreased. The significance of aeration to carbon cycling processes dpended on the residual CH4 concentrations in the water column.
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(2023)Climate change severely threatens ecosystem services and human well-being: vegetation and soils underneath it can be particularly vulnerable to climate warming. Soils hold the largest carbon stock in terrestrial ecosystems, and urban park soils, especially in cool climates, can hold remarkable carbon stocks and may be able to offset some atmospheric CO2 emissions. Land use changes, such as urbanization, influence soil organic carbon formation and soil carbon storages. In this study, I was interested whether three vegetation types (deciduous trees, conifers and lawn) differ in their capacity to store C in their rhizosphere, and whether this is affected by park size. I measured the proportion of tree canopy layer in class A park areas of the city of Helsinki, to estimate soil C storages of these areas and to examine C density (kg C m-2). Proportions of tree canopy layers in different park size groups were measured using QGIS and ortographs. Soil C storages were calculated using existing soil C data and average proportions of conifer and deciduous trees in parks of the city of Helsinki. Park size had a significant effect on proportion of the tree canopy coverage: canopy cover decreases with an increase in park size. Especially large parks are dominated by lawn. The average soil C densities in small, medium and large parks were 23.98 kg C m-2, 23.47 kg C m-2 and 23.15 kg C m-2, respectively. However, the overall proportion of conifer canopy in parks of the city of Helsinki is rather small, resulting in small differences in C densities between different park size categories, despite significant differences in tree canopy coverage between the three size groups. Most of the stored soil C in parks of the city of Helsinki are under lawn, even though it is the least efficient of the three studied vegetation types (deciduous trees, conifers, lawn) in soil C sequestration. Within a park size category and at park level, large parks store the highest amount of carbon per park. Even so, at the city level, the total amount of carbon is highest in the small parks due to their high number. Conifer trees associate with improved C sequestration to soils compared to deciduous trees and lawn. Increasing the amount of conifer trees in urban parks thus likely increase the important C storages of these soils. Results of this study highlight the importance of the contribution of urban parks and especially conifer trees in carbon sequestration. Future research related to urban soil C sequestration and the effects of vegetation type and climatic conditions is needed to better understand soil C accumulation and how the C sequestration of urban park soils could be enhanced.
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(2020)In this paper, I examine the discussions around the concept of carbon sinks. From those discussion of Finnish forestry, I identify frames based on a media material of 108 news articles combining the methodologies of frame analysis and content analysis. I aim to contextualize the carbon sink discussions of the latter half of 2010s and examine how the natural science-based term is used to support varying policy agendas. Building from background literature on the media as a societal actor and a context around Finnish forest discussions and mismatches between science and forest policy, I reflect on the ways that Finnish media frames and contextualizes carbon sink-related forest discussions. Eventually, I identify three dominant and eight secondary frames that describe the ways of using and the transforming of carbon sink as a term in detail. The dominant frames divide the discussion into two clashing ways to communicate carbon sink issues and a third middle ground way of understanding and using the term. The middle ground frame identifies the conflict between the clashing frames and suggests reaching to an understanding as a priority goal in terms of optimal climate change policy. I discuss the results in terms of the frames' policy implications. In addition, I ask how they signal potential developments in forest and climate policy and discourse. The analysis shows that the clearest disagreements in the carbon sink conflicts raise from how forestry restricting policies are seen to affect carbon sink levels and how prominent a role should forest industry have in meeting national and international climate policy targets. The study confirms that carbon sink as a term transforms into altering forms to support distinct, even controversial policy goals because of both definitional and calculative uncertainties.
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(2024)Kaupunkien ilmastotavoitteiden saavuttaminen edellyttää päästöjen vähentämistä, mutta myös kaupunkien kas-villisuuden hiilivarastojen kasvattamista. Kaupunkikasvillisuuden hiilivarastojen tutkimus on kuitenkin vähäistä ja erityisesti kaupunkipensaiden on puutteellista. Pensaat ovat kuitenkin yksi käytetyimmistä kasvillisuustyy-peistä kaupunkialueilla, ja sen vuoksi niiden hiilivarastojen selvittäminen on tärkeää. Tässä tutkimuksessa tien-pientareet on tunnistettu potentiaalisiksi alueiksi kasvattaa Helsingin kaupungin kasvillisuuden hiilenvarastoja. Tienpientareilla kasvaa usein nurmikkoa, jolla on heikko hiilenvarastointikyky. Tämän takia tässä tutkimuksessa ehdotetaan tienpientareilla kasvavien nurmikoiden vaihtamista pieniin pensaisiin, jotta hiilenvarastointikapasi-teettia voitaisiin kasvattaa. Tässä tutkimuksessa käytettiin kuivapainomittausmenetelmää kymmenen eri kaupunkipensaslajin kuivapainojen ja hiilenvarastojen mittaamiseksi. Tutkimuksessa tarkasteltiin myös pensaiden biomassan jakautumista ylä- ja alapuolisten osien välillä. Lisäksi tässä tutkimuksessa tutkittiin mahdollisuutta käyttää pensaiden kokoindeksiä niiden biomassan arvioinnissa, mikä voisi nopeuttaa pensaiden hiilivarastojen tutkimusta tulevaisuudessa. Tämän lisäksi tässä tutkimuksessa laskettiin, kuinka paljon enemmän hiiltä saataisiin varastoitua, jos kaikki Helsingin tienpientareiden nurmikot vaihdettaisiin pieniin pensaisiin. Kolmen tapausesimerkin avulla laskettiin tarkempi pinta-ala, johon pensaat voitaisiin istuttaa, ja siten myös tarkempi hiilenvarasto. Tapausesimerkeissä huomioitiin tieturvallisuuden asettamat rajoitteet pensasistutuksille. Pensaiden hiilenvarastot vaihtelivat merkittävästi eri lajien välillä. Suurimmalla osalla pensaista biomassaa oli eniten yläpuolisissa osissa, mutta oli myös lajeja, joilla juuret muodostivat suurimman osan biomassaa. Kaikista tutkituista pensaista 75 %:lla havaittiin korrelaatiota kokoindeksin ja biomassan välillä. Helsingin tienpientareet, joissa kasvaa nurmikkoa, kattavat yli 1 % kaupungin maapinta-alasta. Jos koko tutkimusalueen nurmikot vaih-dettaisiin pieniksi pensaiksi, hiilen varasto kasvaisi yli 23-kertaiseksi. Tapausesimerkkialueilta saatiin pensaiden osalta yhtä lupaavia tuloksia, vaikka niiden pinta-aloja oli pienennetty. Nurmikot kattavat suuren osan kaupunkien avoimista viheralueista. Niiden käyttäminen nykyisellä mittakaavalla on kuitenkin tarpeetonta, vaikka ne tarjoavatkin tärkeitä hyötyjä kuten avarat tilat ja estetiikkaa. Pensaiden istut-taminen tienvarsille lisäisi aluksi kustannuksia, mutta pitkällä aikavälillä se voisi johtaa kunnossapitosäästöihin, sillä pensaat eivät vaadi jatkuvaa leikkaamista niin kuin nurmikot. Lisäksi pensaiden käyttäminen tienvarsilla tuottaisi monipuolisempia ekosysteemipalveluita verrattuna nurmikoihin, mikä mahdollistaisi paremman sopeu-tumisen ilmastonmuutoksen vaikutuksiin.
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(2021)Physical fitness has declined during the last decades in adolescents. Furthermore, several studies have found a positive association between physical fitness and brain volume in adolescents, which is noteworthy since the adolescent brain undergoes substantial changes during growth and maturation. However, despite the importance of the cerebellum on adolescents' cognition and coordination, there remains a paucity of evidence on the associations between physical fitness and cerebellum characteristics. Thus, a cross-sectional approach was used to explore the relationship of cardiorespiratory fitness (CRF), power, speed-agility, coordination and overall neuromuscular performance index (NPI) with total gray matter (GM) volume of the cerebellum as well as lobules VI & VIIb, and crus I volume in 40 (22 girls; 18 boys) adolescents. Peak oxygen uptake (V̇O2peak) was measured by the maximal ramp test on a cycle ergometer, lower limb power was determined with standing long jump (SLJ), speed-agility was assessed with the 10 x 5-m shuttle-run test, upper limb coordination was determined with the Box and Block Test (BBT) and NPI was calculated as the sum of SLJ, BBT and shuttle-run z-values. Lean mass (LM) and body fat percentage (BF%) were measured using a bioelectrical impedance analysis. Cerebellum GM volume, lobules VI & VIIb, and crus I volumes were measured by magnetic resonance imaging (MRI). Results demonstrated that V̇O2peak/LM was negatively associated (β = -.045 P= .014) with cerebellum GM volume. No statistically significant associations were found between SLJ, shuttle-run, BBT scores or NPI and cerebellum characteristics in all participants. However, a poorer shuttle-run time was associated (β = -.363 P = .024) with smaller crus I volume in girls and V̇O2peak/LM was negatively associated (β = -.501 P = .031) with lobule VIIb volume in boys. These findings suggest that, in general, CRF and speed agility are associated with cerebellum characteristics in adolescents and there may be sex differences. The results extend our knowledge of the associations between physical fitness and brain volume, but more studies should be conducted to understand the relationship further.
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(2023)Chimeric antigen receptor (CAR) T cells are genetically modified usually autologous T cells expressing de novo designed CAR that binds a specific antigen on the surface of the cancer cells, inducing T cell receptor-independent activation and cytotoxic response against the targeted cancer cells. While CAR T cells have been shown to offer effective treatment in acute lymphoblastic leukemia, diffuse large B-cell lymphoma, and multiple myeloma, several resistance mechanisms can lead to CAR T cell exhaustion characterized by impaired functions and the expression of inhibitory receptors. The Finnish Red Cross Blood Service has developed novel CARs, differing in structure from the ones currently published. Since the evasion of CAR T cell exhaustion is considered one of the key objectives in the development of CAR T cell therapy, this Master’s thesis project aimed to create a working method to determine the exhaustion of CAR T cells in vitro after long-term repeated stimulation. In order to induce and measure exhaustion, CAR T cells were produced and activated ex vivo in the presence of IL-2 or IL-7/IL-15 cytokines, cultured long-term and repeatedly stimulated by exposure to target cells. CAR T cell cytotoxicity and expansion were determined and the expression of various inhibitory receptors was analyzed. The method enabled the comparison of the designed CAR T cell candidates and the positive control CD19-CD28ζ CAR T cells in long-term cytotoxic potency. In addition, it helped to reveal the surprising difference between IL-2 and IL-7/IL-15 cytokines and their impact on CAR T cell exhaustion. Although CAR T cells produced with IL-2 had poorer expansion during CAR T cell production than CAR T cells produced with IL-7/IL-15, they showed lower expression of exhaustion-related markers supported by better survival, proliferation and cytotoxic activity during long-term repeated stimulation assay.
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(2014)Lymphangiogenesis is the process that leads to the formation of lymphatic vessels from pre-existing vessels. Vascular endothelial growth factor C (VEGF-C), the ma- jor lymphangiogenic growth factor, is produced as an inactive precursor and needs to be proteolytically processed into a mature form in order to activate its receptors VEGFR-3 and VEGFR-2. A deficiency of VEGF-C during embryonic lymphangiogenesis results in embryonic lethality due to the lack of lymphatic vasculature. Hennekam lymphangiectasia-lymphedema syndrome (OMIM 235510) is in a subset of patients associated with mutations in the collagen- and calcium-binding EGF domains 1 (CCBE1 ) gene. CCBE1 and VEGF-C act at the same stage during embryonic lymphangiogenesis and their deficiency results in similar lymphatic defects. The mechanism behind the lymphatic phenotype caused by CCBE1 mutations is un- known. The aim of this study was to investigate the potential link between VEGF-C and CCBE1 that could contribute to the lymphatic phenotype. In this study, 293T cells were used to observe the effect of CCBE1 on VEGF-C pro- cessing. The co-transfection of constructs coding for CCBE1 and VEGF-C showed processing of the inactive pro-VEGF-C into the active, mature form. However, this processing was efficient only in 293T cells. When CCBE1 from 293T supernatant was purified, A disintegrin and metalloproteinase with thrombospondin type 1 motif 3 (ADAMTS3) co-purified with CCBE1. The levels of pro-VEGF-C and active VEGF-C were monitored by immunoblotting or immunoprecipitating metabolically labeled supernatant with specific antibodies or receptors followed by autoradiography. The activity of the processed VEGF-C was verified by proliferation of Ba/F3 cells stably expressing VEGFR-3/EpoR or VEGFR-2/EpoR chimeras. Furthermore, a VEGFR-3 phosphorylation assay was performed in PAE (Porcine Aortic Endotheial) cells to study details of the CCBE1-mediated regulation of VEGF-C. We found that CCBE1 increases the proteolytic processing of pro-VEGF-C, thereby resulting in increased activity of VEGF-C. CCBE1 itself has no effect on VEGF-C activity but regulates VEGF-C by modulating the activity of the ADAMTS3 protease. We also found that both pro- and mature- VEGF-C can bind to VEGFR-3 but only mature form is able to induce VEGFR-3-mediated signaling. In addition to cleaving VEGF-C, ADAMTS3 was found to directly or indirectly mediate CCBE1 cleavage. The N-terminal amino acid sequence of the ADAMTS3-processed VEGF-C confirmed that ADAMTS3 is the protease responsible for the activation of VEGF-C by 293 cells. Hence, we have identified a mechanism that regulates VEGF-C activity. This mechanism suggests the possible use of CCBE1 as a therapeutic means to treat diseases that involve the lymphatic system.
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(2023)This thesis presents a comprehensive exploration of cerebral palsy, acknowledged as the predominant childhood disability. Traditionally viewed through a narrow lens as primarily a motor disorder, recent investigations have broadened this perception significantly. Beyond motor impairments, cerebral palsy manifests an array of comorbidities spanning sensory, emotional, social, and cognitive domains, reshaping our comprehension of its profound impact on individuals' lives. Challenging the static characterization long associated with cerebral palsy, contemporary research has unveiled a compelling dimension - persistent neuroinflammation. Contradicting the notion of a stable condition, these findings suggest potential progressive aspects. The revelation of persistent neuroinflammation prompts a fundamental reconsideration of cerebral palsy's nature. Should its etiological significance be established, it could revolutionise our understanding, suggesting a dynamic condition evolving over time. Conducted through a rigorous search across Pubmed and MEDLINE databases, this thesis stems from an exhaustive exploration of 900 articles. The literature review was conducted in accordance with the PRISM framework. The literature review provides a comprehensive foundation covering the historical context,pathophysiology, and neuropathology of cerebral palsy. Furthermore, it delves deeply into the aforementioned non-classical perspectives, shedding light on the multifaceted nature of this neurological condition. By synthesising classical and contemporary viewpoints, this study endeavours to broaden the discourse surrounding cerebral palsy, fostering a more inclusive and nuanced comprehension of its complexities. This thesis seeks to bridge the gap between traditional views of cerebral palsy as solely a motor disorder and the evolving understanding of its diverse manifestations across various domains. By integrating insights from multiple disciplines and challenging existing paradigms, it aims to contribute to a more holistic framework for conceptualising cerebral palsy. This integrated perspective aims to enhance not only our theoretical understanding but also the practical implications for interventions and support strategies tailored to the multifaceted needs of individuals living with cerebral palsy.
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(2015)Forest certification has been used as a tool to promote forestry responsibility towards sustainable forest management. Forest Stewardship Council (FSC) is one of the certification systems that is well recognised in Europe. Nevertheless, compared to other European countries, the number of FSC chain of custody (CoC) certifications in Finland is relatively low. Semi-structured interviews were conducted with six FSC CoC certified companies to explore their experiences towards implementing and maintaining the system in their companies. The sample group was comprised of wood and paper product industries in manufacturing and trading sectors. Thematic analysis of the interviews revealed the challenges companies encountered. The results indicated that there were eight types of challenges, including three internal and five external ones, hindering the development of FSC CoC certification in Finland. Internal challenges included competence, financial resources, and a lack of motivation to change. External challenges included insufficient marketing and demand, uncertain cost benefit, keen competitor programmes, limited supply, and long trademark approval time. Meanwhile, the relevant solutions these companies adopted to deal with the challenges were discussed. Since external challenges out-numbered internal ones, it seemed that certified companies are not able to tackle the existing challenges alone. Joint-effort among other actors in the forestry sector, for instance, the national authority, FSC national office, certification bodies are essential to influence the rate of certification uptake. Furthermore, participants discussed about the future development of FSC CoC certification system in Finland. Interviewees believed that the enactment of the EU Timber Regulation (EUTR) and the introduction of forest certification into national public procurement policy could positively impact the development of the system. The results of this study could be used as a reference for potential certificate users to prepare themselves for implementing FSC CoC certification system. In addition, the study could shed a light on the development of FSC in Finland in the future.
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(2023)The heating season 2022–2023 was exceptional in Finland due to the electricity crisis. Electricity saving became a hot topic in public discussion, and households reduced their electricity consumption significantly. This study focuses on the changes that happened in detached house dwellers’ everyday routines: how detached house dwellers’ electricity consumption-related practices changed, and why they changed during the electricity crisis. Understanding how changes happen in electricity consumption-related practices is especially important in the ongoing era of the energy transition. The study is situated within social scientific energy research and the theoretical framework is based on the theories of practice. The study draws on six in-depth interviews of Finnish detached house dwellers living in the Helsinki metropolitan area or the Uusimaa region. The interviews focused on changes in detached house dwellers’ electricity consumption-related practices during the electricity crisis. The results of the study indicate that some practices are more flexible than others. The interviewed households controlled and replaced the material elements of some practices, especially heating devices of indoor spaces and household water. A new practice of monitoring electricity prices was adopted by households with spot-price electricity contracts, who also time-shifted some of their practices based on the price. The interviewed households focused especially on reducing electricity consumption which they considered ‘extra’ consumption. Some of the households also challenged some comfort-related norms and conventional ways of conducting certain practices. Electricity price was stated as the primary reason to change electricity consumption-related practices. Some of the interviewees also mentioned recommendations for saving electricity impacting their practices. It is interpreted that new meanings of scarcity were attached to electricity during the crisis. Electricity became a more visible element of practices, which led the interviewed households to reflect on their electricity consumption on a general level
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(2021)The changes in lake diatom assemblages as a response to climate warming over the past three decades were examined in 26 lakes across Northwestern Finnish Lapland using multivariate statistical techniques. The lakes are distributed along a steep climatic and vegetational gradient, covering three distinct vegetation zones spanning boreal coniferous forest, mountain birch woodland, and treeless tundra. Lakes were selected following a study realised by Weckström and Korhola in 2001, who had sampled the same lakes for surface-sediment diatom assemblages, physical, and chemical limnological variables. Climate data from the past 30 years was retrieved, showing a slow and steady yearly increase in temperature, with strong seasonal fluctuation and fall months experiencing the strongest warming. Surface sediment samples were taken from the lakes and their diatom communities analysed. A total of 185 diatom taxa representing 27 genera were recorded. Ordination techniques (DCA, CCA) at the genus and species level were performed to identify the main patterns of variation between diatom data from the original data set and the current study, and their relationship to environmental variables. Strong changes were recorded in four of the lakes with major shifts in dominant diatom species. Moderate changes were recorded in eight lakes, where dominance changes were recorded for a few species while the majority remained unchanged. The remaining 14 lakes did not show noticeable changes over the 30-year period. Changes observed in the studied lakes did not follow a widely observed pattern in northern Hemisphere lakes. The results indicate that while climate change is a driving factor behind changing lake dynamics with increasing temperatures and decreasing lake ice cover duration, it cannot be the only force responsible.
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(2024)Reindeer herding and climate change are causing notable changes in tundra ecosystems. In this thesis, I examine the impacts of summer reindeer grazing and climate change on Fennoscandian tundra moss and lichen communities at Mt. Saana, North-Western Finnish Lapland. The research questions are whether there have been temporal changes in moss and lichen communities over three decades, if the changes are consistent under different grazing pressures, and if the changes reflect recent climate change. The study is based on permanent plots and long-term time series data from 1990 to 2023 at intervals of about ten years. The results indicate significant correlations between reindeer grazing and moss and lichen abundances and an indication of climate change affecting the vegetation composition. Heavy grazing pressure during summer reduced moss and lichen abundances, particularly affecting lichens, while mosses benefit from moderate grazing pressure. During the study period, mosses had overall increased, while lichens had decreased. A slight recovery of lichens was observed between 2010 and 2023. At Kilpisjärvi, mean temperatures have increased significantly over the study period, affecting vegetation growth conditions. The increase in moss abundance could be related to the warmer temperatures and the lichen dynamics to changes in snow cover, warm winter events and increased competition from vascular plants. The temporal changes are also possible due to variations in grazing pressure. Overall, the findings emphasize the significant effects caused by reindeer grazing and climate change in tundra vegetation. Thus, the effects of reindeer grazing and climate change should be considered simultaneously when studying the changes in vegetation composition in tundra environments.
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(2021)Mobility, the somewhat regular and recurring physical movement of people from place to place, is a very important part of a broader transition to sustainability. In Finland the transport sector accounts for 20 % of total greenhouse gas emissions and while emissions have been steadily declining, the pace is not sufficient to meet current emission cut targets. When looking at household generated greenhouse gas emissions, mobility is the single largest contributor. Previous research has focused a lot on technological advancements and individuals’ choices as causes and solutions to sustainable mobility. These approaches have been criticized for underemphasizing the importance of social conditions. Practice theories have been presented as an alternative way of understanding mobility behaviors, challenging the mainstream individualistic explanations. Practices are routinized human behaviors that are made of several elements of materials, meanings, and competences. This thesis adopts a practice theoretical view in analyzing people’s mobility before and during the COVID-19 pandemic. The aim is to learn what practice theory can teach us about sustainable mobility, and how the pandemic has affected people’s mobility in Finland. Nine semi-structured interviews were conducted, asking the participants about their mobility practices before and during the COVID-19 pandemic, forming a comprehensive picture of their daily lives from a mobility point of view. The results were analyzed using qualitative theory-based content analysis. The results indicated that people’s mobility is a complex system which was largely affected by the COVID-19 pandemic. Various elements either enabling or hindering the use of different transport modes were identified, as were important connections between different mobility practices. Practice theory has been often used to research one mobility practice at a time and the broader look of this study, focusing on multiple mobility practices, is potentially the most important contribution this thesis makes to previous mobility research. While not providing direct answers to how people’s mobility could be made more sustainable, this thesis makes an important contribution to practice theoretical mobility research which in a Finnish context is very scarce.
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(2024)The proper differentiation of cells in early human development is essential for the success of a pregnancy. The first cell-fate decision occurs when totipotent cells differentiate into inner cell mass and trophectoderm, forming a blastocyst. Trophoblast cells differentiate from the trophectoderm and form the placenta. Defects in trophoblast development can lead to several pathologies, such as preeclampsia, miscarriage and intrauterine growth restriction. TFAP2C is a gene that is known to have an important role in the differentiation of trophoblast, although its function is not completely understood. Recent studies have suggested that TFAP2C has a promoter that has not been previously annotated, and it is not yet known what functions different TFAP2C promoters have. The aim of this thesis is to characterise how the activation of this novel TFAP2C promoter or the consensus promoter affects TFAP2C expression and whether the activation of different promoters changes how human pluripotent stem cells differentiate. In addition, this thesis aims to detect whether different TFAP2C protein variants, which are produced by these promoters, explain the possible variation in differentiation. TFAP2C promoters were activated with CRISPR activation, and different TFAP2C variants were expressed as transgenes in pluripotent stem cells. Gene expression was studied with immunocytochemistry and quantitative reverse transcription PCR. The activation of the consensus promoter increased TFAP2C expression more than the activation of the novel promoter. However, activation of both and expression of the protein variants produced from them made cells differentiate into trophoblast-like cells and express trophoblast markers. Nonetheless, the novel promoter and protein variant seemed to differentiate cells into trophoblast more efficiently. Because the activation of the promoters and the expression of their corresponding protein variants led to similar results, it seems likely that the alteration in differentiation is caused by the different TFAP2C protein variants. The functional difference between variants might be affected by the presence of a SUMOylation motif in the wild-type TFAP2C. These results may help to better understand the role of TFAP2C in human embryonic development and create applications for assisted reproduction and infertility treatments, as well as facilitate the development of cell models that can be used in research and therapy.
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(2022)Background– The BCL-2 protein family members are major regulators of apoptosis, and the anti-apoptotic (pro-survival) members of the family is commonly targeted with BH3 mimetic drugs in haematological cancers. However, these treatments have not been very impactful when administered as single agents and they have long been investigated for combination therapy with other agents. Acute myeloid leukaemia (AML) is one of the difficult-to-cure haematological malignancies. A recently approved therapy for AML consists of the combinatorial administration of venetoclax (a selective BCL-2 inhibitor) and a DNA methyltransferase (DNMT) inhibitor such as azacitidine or decitabine. Although this novel therapy has shown promising clinical results, the majority of the patients still relapse under this treatment. These relapsed patients typically become highly resistant to treatment and have poor prognosis, emphasising the need for new effective drug combinations. Apart from BCL-2, other family members like BCL-xL and MCL1 are also common targets of BH3-mimetic drugs. This project thus aims to understand and characterise the resistance against BH3-mimetics and investigate new therapeutic approaches to overcome the challenges of resistance. Aims– This study aims (i) to characterise BH3-resistant AML cell lines for uncovering the mechanisms of drug resistance, and (ii) to identify possible combination treatment options for overcoming drug-resistance. Methods– Viability assays with Cell Titer Glo® (CTG) and Drug Sensitivity and Resistance Testing (DSRT). The long-term effectiveness of venetoclax, azacitidine and talazoparib (a PARP inhibitor) as single agents, double combinations and triple combination were investigated with Time-to-Progression (TTP) assay. For the resistant cell line models, underlying resistance mechanisms were assessed by checking protein expression of pro- and/or anti-apoptotic members of the BCL-2 family members with western blot (WB). Real-time quantitative PCR (RT-qPCR) and WB were carried out for transcriptional and translational expression analyses of certain DNA damage-associated genes in PARP inhibitor-resistant cell lines. Results– Drug screening with DSRT has revealed promising results for two combination treatments of a BCL-xL inhibitor (A-1331852) (i) with an Aurora kinase A inhibitor (alisertib) and (ii) with an MCL1 inhibitor (S63845) for BCL-xL inhibitor-resistant cells. WB analyses of BCL-2 family members showed translational upregulation of un-inhibited members of the anti-apoptotic proteins in BH3-mimetic-resistant cell lines. A venetoclax-resistant AML cell line showed increased levels of the DNA damage marker P-γ-H2Ax upon treatments containing venetoclax, as well as increased levels of cleaved-PARP1, indicating induction of apoptosis. RT-qPCR analyses revealed increased mRNA expression of PARP1 in two resistant cell lines, whereas no significant expression changes in other DNA repair mechanism genes on the transcriptional level. Conclusions– In BH3-mimetic-resistant AML cell lines, apoptosis is avoided through translational upregulation of un-inhibited anti-apoptotic members of the BCL-2 family, and this resistance can be countered by combination treatment for additional inhibition of the compensatory anti-apoptotic proteins. Venetoclax is still effective on cells resistant to it, by inducing DNA damage and sensitising these cells against inhibitors of the members of DNA repair pathway. The transcriptional upregulation of PARP1 and the increase in its auto-catalytic activity suggests the DNA damage-inducing effects of the triple combination treatment [Ven + Aza + Tal].
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