Skip to main content
Login | Suomeksi | På svenska | In English

Browsing by master's degree program "Genetiikan ja molekulaaristen biotieteiden maisteriohjelma"

Sort by: Order: Results:

  • Lamichane, Nicole (2019)
    Over the past years sugar consumption has seen great increases worldwide, together with a rise in the prevalence of metabolic diseases. There is a growing need for a comprehensive characterisation of the genes involved in sugar metabolism, yet the mechanisms by which cells sense and respond to sugars in vivo have remained incompletely understood. Here, I analyse members of a protein family best known for their regulation of differentiation during development with regards to their role in sugar metabolism. The Hairy and Enhancer of Split (HES) protein family are a group of basic helix-loop-helix (bHLH) transcription factors that function as major downstream effectors of the Notch signalling pathway. In mammals, the HES proteins have mostly been studied for their role in cell differentiation, but HES1 has been implicated in metabolic control. Drosophila has several transcription factors belonging to the HES family, including Hairy and seven bHLH transcription factors located in the Enhancer of split complex (E(spl)-C). The E(spl)-C bHLH transcription factors display high homology and are considered to be genetically redundant, and therefore little is known about their individual functions. The other HES family members in Drosophila have not previously been linked to metabolic regulation, but Hairy has been shown to repress the tricarboxylic acid cycle. In light of the findings implicating HES1 and Hairy in the regulation of metabolism, I systematically investigated the role of the HES transcription factors in sugar metabolism. By using the GAL4/UAS system in Drosophila melanogaster, I knocked down gene expression of each of the family members, and raised the flies on diets varying in sugar content to identify possible sugar intolerance phenotypes. Here, I show that knockdown of one of the E(spl)-C bHLH genes led to severe sugar intolerance that affected both survival and organismal growth, but did not alter the levels of circulating carbohydrates and storage lipids as measured with colorimetric assays and lipid staining. Furthermore, I identify the tissues in which this transcription factor functions to provide sugar tolerance. Using analysis of publically available chromatin-immunoprecipitation sequencing data coupled with quantitative RT-PCR, I uncover mTOR target Thor/4E-BP as a putative target gene. Additionally, I show that Hairy is similarly required for complete sugar tolerance, but that the mechanism differs from the E(spl)-C bHLH transcription factor. Hairy binds to and positively regulates expression of genes involved in glycolysis and the pentose phosphate pathway, suggestive of a cooperation with earlier known regulators of sugar sensing. In conclusion, I have shown that only two HES family members are involved in the regulation of sugar metabolism and that their regulatory mechanisms are distinct, implying that the HES family members have more diverse roles than previously assumed.
  • Larmala, Saara (2023)
    The field of gene technology, which falls under the umbrella of biotechnology, presents challenges in business development and commercialisation. Understanding the field characteristics is crucial for successful commercialisation, as it can significantly impact the available strategies for bringing products or services to market, ultimately shaping the business model. This study aims to investigate and understand the challenges associated with commercializing gene technology, including identifying any typical challenge profiles specific to the field and possibly arising from the biological material. The research involves semi-structured interviews with multiple companies, venture capitals, and experts in the field to gain a comprehensive understanding of the challenges. The collected data is then analysed to identify common characteristics and business practices against a commercialisation model frame. The motivation behind this study is to provide researchers and other stakeholders with insights into the challenges they may face while commercializing gene technologies, with the aim of lowering the threshold for business creation. The findings reveal that there are two major groups of companies, each with their specific challenges. The challenges for the major group revolve around business know-how, HR, and sales, while the minor group faces challenges related to technology and regulation. However, a common theme is the limited market awareness among customers, which requires significant efforts in sales, marketing, and communications. The study provides guidance to company founders on the different challenges they should be prepared for and offers insights to society on how to harness the value of gene technologies.
  • Puutio, Johanna (2020)
    Extracellular vesicles (EVs) are phospholipid bilayer-enclosed nanoparticles that are secreted by eukaryotic and prokaryotic cells. EVs carry macromolecules and signalling molecules to adjacent cells and play an important role in intercellular communication under both pathologic and homeostatic conditions. Therefore, they have become of significant interest for their therapeutic, diagnostic and prognostic potential. EVs are small and highly heterogeneous in size, shape, cargo and membrane composition, posing several challenges for establishing analytical and clinical guidelines. Therefore, EV research requires standardized and robust methods for their separation and characterization. In this study physical and immunochemical methods were employed to characterize human platelet-derived EVs (pEVs) generated from platelets activated with different external biochemical stimuli. The platelet-activating effect of the pro-inflammatory S100A8/A9 protein complex and a combination of thrombin and collagen were studied with nano flow cytometry. The size distribution of pEVs was studied with nanoparticle tracking analysis (NTA) and asymmetrical flow field-flow fractionation (AF4), which represents a newly emerging method on the EV field. Finally, fluorescent labelling and co-localization analysis were employed to characterize membrane marker composition of pEVs and assess its usefulness as an analytic tool for EV research. We succeeded in providing new hints towards meaningful discoveries in platelet biology by characterizing the way platelets respond to inflammatory and hemostatic signals by shedding pEVs. When platelet activation markers are characterized with flow cytometry, the S100A8/A9 protein appeared to cause a shift in membrane activation markers when compared to the thrombin- collagen mix and the baseline control. Increased TLT-1 translocation and decreased integrin αIIbβ3 expression on pEV surfaces suggests that S100A8/A9 induced pEV secretion through differently packed platelet α-granules, rather than from the plasma membrane. An increase in TLT-1 expression compared to decreased P-selectin and αIIbβ3 suggests that S100A8/A9 stimulation shifts platelet phenotype towards secretion rather than aggregation. A protocol for small pEV separation with AF4-MALS was set up. With this method, subtle differences between small pEV populations were seen that were not distinguishable with NTA or flow cytometry. When investigated with AF4-MALS, S100A8/A9 induced pEVs appeared larger than those produced with thrombin- collagen activation. The mean particle sizes of the pEV populations obtained from activated platelets were generally also larger than those produced without an activator. We tested novel methods to detect subtle differences in small EV population sizes that are easily missed with conventional methods due to their technical limitations. A well-optimised AF4 protocol can detect different pEV subpopulations and is a promising tool for EV. In the future, when AF4 is combined with a MALS detector and a fraction collector, nanoimaging of fluorescently labelled EVs could be combined with it as a downstream application to obtain information on their versatile biological functions.
  • Elomaa, Ellinoora Juulia (2020)
    The human cerebral cortex is characteristically large and folded, which can be majorly attributed to the high number and variety of neural progenitors during embryonic development. Radial glial cells are essential neural progenitors during neurogenesis. In addition to giving rise to new cell types, they also provide scaffold for migrating newborn neurons. Radial glia are known to portray peculiar characteristics in their cell division process, including unique migratory behavior as well as specifically regulated cleavage furrow orientation. While these processes of radial glial division have been studied extensively, the underlying molecular mechanisms are still largely unknown. ABBA (actin-bundling protein with BAIAP2 homology) and NEDD9 (neural precursor cell expressed, developmentally downregulated 9) are proteins, which are both known to be expressed in certain radial glia progenitors during embryonic development, while they are mainly absent in neurons. ABBA has a defined role of regulating plasma membrane deformation and actin polymerization in radial glia, while NEDD9 expression levels are a known factor in the correct progression from mitosis to cytokinesis. An interaction between ABBA and NEDD9 has previously been identified in a yeast two-hybrid screen done for the embryonic mouse brain. The aim of this thesis was to validate the interaction between ABBA and NEDD9 biochemically. First, their interaction was evaluated by doing co-immunoprecipitation assays on the endogenous proteins from C6 cells. The second approach was to test, whether their interaction is directly mediated by the N-terminal SH3-domain of NEDD9 and the proline-rich C-terminal portion of ABBA. This was done by doing biochemical binding assays using purified proteins and domains of interest. While co-immunoprecipitation of the two proteins gave results indicating an interaction, I could show that there is no direct binding between NEDD9 SH3-domain and ABBA, suggesting that the interaction might require other domains or be indirect. Together, these results provide valuable information that will help characterize what roles of ABBA and NEDD9 play in cortical development and beyond.
  • Tiusanen, Ville (2021)
    Enhancers are important regulatory elements of DNA, that are bound by transcription factors (TFs) to regulate gene expression. Enhancers control cell type specific gene expression and they can form structures called super-enhancers, that consist of multiple normal enhancers and are bound by high numbers and variety of transcription factors. These super-enhancers are important for defining cell identity and changes in the super-enhancer landscape have been linked to different cancers. In this project, characterization of super-enhancers and their transcription factors composition between primary and cancer cells were studied using genome-wide next-generation sequencing data from multiple assays, such as ChIP-seq, RNA-seq and ATAC-seq. The focus of the project was on the data processing and analysis to identify and characterize the super-enhancers. Analyses included GSEA, heatmap binding analysis, peak and super-enhancer calling and IGV analysis. This project used pancreatic HPDE cell line for primary cells and different cancers with endodermal origin as cancer cell lines. The goal of the thesis was to try show characteristic features of super-enhancers and their features in normal and cancer cells. Data analysis showed that distinct super-enhancers can be identified in cancer cells and defined super-enhancers had typical strong binding for specific transcription factor and histone modification such as histone 3 lysine 27 acetylation (H3K27ac) mark of active enhancers. Super-enhancer regions were located in highly accessible chromatin regions of the genome, and genes that were associated with HPDE super-enhancers could be shown to have association with cell identity. Peak and super-enhancer calling counts varied between cell lines for transcription factors, histone modifications and super-enhancers. Visualization of super-enhancers was successful and could show transcription factor binding and active enhancers that establish the super-enhancer structure. Comprehensive analyses allowed us to characterize typical features of super-enhancers and show differences in the numbers of super-enhancers between primary and cancer cell lines and cancer cell lines of different organ types. Analysis of the transcription factor binding showed unique peaks on some of the super-enhancers, and these peaks might have a role in inducing the super-enhancer structure.
  • Jokinen, Vilja (2021)
    Uterine leiomyomas are benign smooth muscle tumors arising in myometrium. They are very common, and the incidence in women is up to 70% by the age of 50. Usually, leiomyomas are asymptomatic, but some patients suffer from various symptoms, including abnormal uterine bleeding, pelvic pain, urinary frequency, and constipation. Uterine leiomyomas may also cause subfertility. Genetic alterations in the known driver genes MED12, HMGA2, FH, and COL4A5-6 account for about 90 % of all leiomyomas. These initiator mutations result in distinct molecular subtypes of leiomyomas. The majority of whole-genome sequencing (WGS) studies analyzing chromosomal rearrangements have been performed using fresh frozen tissues. One aim of this study was to examine the feasibility of detecting chromosomal rearrangements from WGS data of formalin-fixed paraffin embedded (FFPE) tissue samples. Previous results from 3’RNA-sequencing data revealed a subset of uterine leiomyoma samples that displayed similar gene expression patterns with HMGA2-positive leiomyomas but were previously classified as HMGA2-negative by immunohistochemistry. According to 3’RNA-sequencing, all these tumors overexpressed PLAG1, and some of them overexpressed HMGA2 or HMGA1. Thus, the second aim of this study was to identify driver mutations in these leiomyoma samples using WGS. In this study, WGS was performed for 16 leiomyoma and 4 normal myometrium FFPE samples. The following bioinformatic tools were used to detect somatic alterations at multiple levels: Delly for chromosomal rearrangements, CNVkit for copy-number alterations, and Mutect for point mutations and small insertions and deletions. Sanger sequencing was used to validate findings. The quality of WGS data obtained from FFPE samples was sufficient for detecting chromosomal rearrangements, although the number of calls were quite high. We identified recurrent chromosomal rearrangements affecting HMGA2, HMGA1, and PLAG1, mutually exclusively. One sample did not harbor any of these rearrangements, but a deletion in COL4A5-6 was found. Biallelic loss of DEPDC5 was seen in one sample with an HMGA2 rearrangement and in another sample with an HMGA1 rearrangement. HMGA2 and HMGA1 encode architectural chromatin proteins regulating several transcription factors. It is well-known that HMGA2 upregulates PLAG1 expression. The structure and functionality of HMGA2 and HMGA1 are very similar and conserved, so it might be that HMGA1 may also regulate PLAG1 expression. The results of this study suggest that HMGA2 and HMGA1 drive tumorigenesis by regulating PLAG1, and thus, PLAG1 rearrangements resulting in PLAG1 overexpression can also drive tumorigenesis. A few samples, previously classified as HMGA2-negative by immunohistochemistry, revealed to harbor HMGA2 rearrangements, suggesting that the proportion of HMGA2-positive leiomyomas might be underestimated in previous studies using immunohistochemistry. Only one study has previously reported biallelic inactivation of DEPDC5 in leiomyomas, and the results of this study support the idea that biallelic loss of DEPDC5 is a secondary driver event in uterine leiomyomas.
  • Avdonin, Savva (2021)
    Tiivistelmä – Referat – Abstract ROS or Reactive Oxygen Species can be found throughout all living organisms on the planet. Without ROS, processes, which are essential for the sustainment of most living organisms, such as respiration would not be possible. On the other hand, uncontrolled ROS generation can cause severe damage to the cellular structure. The family of ROS includes multiple compounds, which share a common trait of high chemical activity. ROS can be produced on demand by specific enzymes which are localized within cellular structures, such as membranes. One group of enzymes is called NADPH (Nicotinamide adenine dinucleotide phosphate) oxidases. These enzymes possess common structure which is composed of transmembrane region with multiple loop helixes and usually two or more terminal motifs, which are devised into regulatory EF-hand motifs and catalytic motifs. NADPH oxidases are essential ROS producers and can be found throughout most clades of living organism and are widely represented in different cellular compartments and distributed across different tissues in multicellular organisms. As an example, Nox family of NADPH oxidases can be found in human tissues and immune cells. Another common group of NADPH oxidases is respiratory burst oxidase homologues (RBOH) can be found in plants. Members of this group play important role in plant immune defense against pathogens. One example is AtRBOHD, which is expressed in Arabidopsis genus of plants. Upon activation, these enzymes are known to produce hydrogen peroxide (H2O2) as mean of antibacterial defense. These host defense mechanisms are known to be driven by different signaling molecules. It has been determined that in some examples of NADPH Oxidases, including Nox5 and RBOHD, the state of activation can be induced through the effects of Ca2+ ions. Moreover, it has been determined, that ROS-producing state of these NADPH oxidases is achieved through change of conformation. This change in conformation is attributed to the different modes of interaction of motifs of oxidases, which are dependent on concentration of bivalent cation Ca2+. Previous research regarding intramolecular interactions within specific NADPH oxidase- Nox5β has been performed by multiple research teams and different sources appear to contradict each other on the exact mode of interaction of Nox5β EF-hand upon presence of Ca2+. Therefore the exact interaction model of terminals of Nox5β is unclear. In addition, the effect of presence of Ca2+ on the interaction terminals in another representative of NADPH oxidases- AtRBOHD, which possess highly analogous molecular structure of catalytic C-terminus to Nox5β, has never been thoroughly studied, as well as interactive cross-compatibility of the C and N terminals from these two distinct species of NADPH oxidases. The objectives of this research are to analyze intramolecular interactions of N- and C- terminals in Arabidopsis RBOHD and Human Nox5β upon presence of ionic calcium, compare Ca2+-induced terminals interactions in said oxidases and to establish possible cross-compatibility of terminals in these two distinct NADPH oxidase species. Practical aspects of this research included cloning the C- and N- cytoplasmic regions of Nox5β and AtRBOHD into bacterial expression vectors utilizing the PIPE cloning method, heterologous production of epitope-tagged tails of NOX5β and RBOHD in E. Coli BL21 and finally in-vitro pull-down assays to analyse the interactions of the tails upon the presence of Ca2+ as well as interactive cross-compatibility of these tails. By utilizing methods mentioned above, this research has demonstrated that interactions of terminals motifs both in Nox5β and AtRBOHD are possible even in calcium-deprived environment, which was achieved through use calcium-binding agent (EDTA) and the effect of calcium on interactions of terminals both in RBOHD and Nox5β is very limited if not insignificant. This research has also demonstrated that the cross-compatible interactions between terminals of Nox5β and AtRBOHD are possible. Results of this research indicate a strong structural conservation within NADPH oxidases, which indicates similar intramolecular interaction mechanisms within two highly diverged species. These findings may prove to be useful as a background for the future research regarding ROS producing enzymes and evolutional conservation in structures of oxidases.
  • Lukander, Volter (2022)
    Spinal muscular atrophy of Jokela type (SMAJ) is an autosomal dominant motor-neuron disease caused by a missense mutation c.197G>T, p.G66V in the gene CHCHD10. Coiled-coil-helix-coiled-coil-helix domain-containing protein 10 (CHCHD10) is a nuclear-encoded mitochondrial protein located in the intermembrane space (IMS) of mitochondria with an unknown exact function and disease-causing mechanism. In this project, the overarching aim was to correct a heterozygous SMAJ-causing mutation in patient myoblast cells with CRISPR-Cas9 genome editing. The goal was to create a genetically identical, isogenic, cell line to study only the effects of the mutation on cellular phenotype in vitro. Human myoblast cells isolated from patient biopsies provide the most pertinent experimental model to study neuromuscular atrophy-associated mutations in their natural genomic environment. More specific aims included genome editing optimization with myoblast cells, since it is not as widely conducted as with some other cell types, such as iPSCs. CRISPR-Cas9 ribonucleoprotein (RNP) complex and associated donor template were used to induce homology-directed repair (HDR) in the genome of patient-derived myoblast cells and correct the mutation. After optimization of electroporation conditions for myoblast cells, guide RNAs were designed and transfected into patient myoblasts. Clonal cell lines were made by utilizing techniques such as fluorescence adjusted cell sorting (FACS) and manual colony picking. The success and precision of genome editing were analyzed by Sanger sequencing, comparing the performance of the different guide RNAs with restriction enzyme analysis and Synthego ICE CRISPR web tool, and screening regions of potential off-target genome editing. A genome-edited myoblast cell line with the CHCHD10 c.197G>T mutation corrected, was successfully generated to provide an isogenic control for the patient myoblast cell line. Optimization of myoblast electroporation was successful and conditions used proved to be effective. Clonal cell line creation proved to be challenging with myoblast cells and work is still needed to improve the viability of single-cell clones after FACS. Nevertheless, the advances taken here regarding myoblast genome editing with CRISPR-Cas9 offer a fertile avenue for future research of myoblasts genome manipulation, myogenic disorders, and the role of CHCHD10 in skeletal muscle and SMAJ. Comparing the CHCHD10 protein level and mRNA expression between patient cells, corrected myoblasts, and differentiated myotubes is an area of future research. Future work also includes measuring the mitochondrial integrated stress response in both cell lines and co-culturing myotubes and iPSC derived motor neurons to study the effects of p.G66V on neuromuscular junction (NMJ) formation.
  • Keskinen, Timo (2020)
    Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited autosomal dominant disease that leads to cognitive impairment, vascular dementia and ischemic strokes. In CADASIL, vascular smooth muscle cells (VSMCs) degrade gradually and are replaced by connective tissue in the small and mid-sized arteries in the brain. Extracellular granular osmiophilic material (GOM) that surround the VSMCs are a unique feature in CADASIL. The causal gene behind CADASIL is Notch3, which encodes a transmembrane protein with a signaling function. There are over 200 cysteine-altering mutations that cause CADASIL in Notch3. The potential pathology causing mechanism is still unclear, but most likely the mechanism is linked to the aggregation of GOM deposits that are potentially toxic to VSMCs. This thesis project aimed to correct CADASIL causing c.475C>T mutation in Notch3 in different CADASIL cell lines with different CRISPR base editor systems. Another aim was to create induced pluripotent stem cell (iPSC) lines from a CADASIL patient-derived skin biopsy sample to be used in the creation of an in vitro disease model for CADASIL. RNA-based ABEmax base editor system was used to correct immortalized- and primary- CADASIL cell lines. DNA-based ABEmax base editor system was used as a positive control. Simultaneous pluripotent reprogramming and pathogenic CADASIL mutation correction were done in the same transfection during this project. The editing efficiencies were evaluated by Sanger sequencing the genomic target region before and after the transfection. The editing efficiencies were good in general compared to literature. They ranged from 27 % to 73 % target base editing efficiency depending on the editing system-, guide-RNAs - and electroporation parameters used. Confirmed proximal off-target effects were not detected, and distal off-target effects were not evaluated.
  • Sket, Tina (2020)
    Endoplasmic reticulum (ER) stress is caused by the accumulation of unfolded proteins in the ER, which leads to the activation of unfolded protein response (UPR) through three transmembrane protein sensors located in the ER membrane. The sensors correspond to three branches of the UPR, namely protein kinase RNA-like endoplasmic reticulum kinase (PERK), activating transcription factor 6 (ATF6), and inositol-requiring enzyme 1 (IRE1) branches. Upon ER stress, IRE1 dimerizes and oligomerizes, and its endonuclease domain is activated. It specifically targets X-box-binding protein 1 (XBP1) mRNA, from which a 26 nt intron is spliced. This allows a complete translation of spliced XBP1 mRNA into a functional protein that acts as a transcription factor. Together with the other pathways, the UPR leads to a decrease in the protein folding load by causing a reduction in the general level of protein translation, and by inducing the expression of protein folding machinery. However, if the UPR is activated continuously for a long time, the apoptotic pathway will be triggered, and the cell will die. ER stress and UPR are associated with various disorders, such as some types of cancer, diabetes, chronic inflammatory syndromes, and particularly neurodegeneration. For example, in Parkinson’s disease, it was suggested that prolonged ER stress induces the extensive apoptosis of dopaminergic neurons in substantia nigra pars compacta region of the midbrain. This hinders the normal functioning of the nigrostriatal pathway, and hence results in the progressive development of Parkinson’s motor symptoms. In order to study the regulation or IRE1 branch of the UPR, and to identify the ER-stress-modulating compounds, a human luciferase reporter cell line (XBP1-NLuc) was created in this work. The reporter was expressed when IRE1 splicing was activated, since the XBP1 intron fragment was fused to the Nano luciferase gene. The expression of the reporter was observed with luciferase assay at several time points during treatments. The treatments were done with ER stress inducers thapsigargin and tunicamycin, and with IRE1 inhibitors KIRA6 and 4μ8c, or the combination of those. Quantitative PCR (qPCR) was used to validate the expression of the reporter and to monitor the expression of the other branches of the UPR. Additionally, the oligomerization of IRE1 was observed with IRE1-GFP cell line that was treated identically to the XBP1-NLuc cell line, fixed, stained for nuclei, and imaged with fluorescent microscopy. After imaging, the IRE1-GFP clusters were analysed and quantified with CellProfiller and CellAnalyst softwares. Both cell lines were used to test the effect of neurotrophic factors CDNF, MANF, and MANF mutant isomers on the UPR with and without tunicamycin treatment. Collectively, the experiments confirmed that XBP1-NLuc cell line was created successfully and that it accurately reports IRE1 splicing activity. As expected, ER stress treatment increased the reporter expression, while IRE1 inhibitors decreased the expression of the reporter. qPCR revealed that the other observed UPR markers were activated as well upon thapsigargin treatment, however, they were not decreased with the treatment with IRE1 specific inhibitors. In line with XBP1-NLuc cell line, the IRE1-GFP cell line demonstrated an increased oligomerization of IRE1 upon ER stress induction. The KIRA6 inhibitor of IRE1, which prevents IRE1 oligomerization, decreased the formation of IRE1-GFP clusters. Additionally, the IRE1-endonuclease-activity inhibitor 4μ8c induced the formation of IRE1-GFP clusters. Curiously, the distribution of the intensity of IRE1-GFP clusters was bimodal and could point to two manners of IRE1 clustering and/or activation. Together, the experiments done with cells transfected with CDNF, MANF or MANF mutants, suggested that the tested neurotrophic factors decreased IRE1 oligomerization and its activation. However, there were substantial problems in the quantification of viable cells, which should be considered in the interpretation of these results. No significant difference among the tested neurotrophic factors was observed. In conclusion, the XBP1-NLuc reporter cell line provided a reliable reporter of IRE1 endonuclease activity, whose expression is increased during the ER stress. Together with IRE1-GFP cell line, it revealed the amount of IRE1 oligomerization and activation under various treatments and at different time points relative to treatments. Due to the effectiveness and accuracy, the XBP1-NLuc cell line can be further used in studying the regulation and activation of IRE1, as well as for the identification of ER-stress modulating molecules, which can be used for development of novel treatments for ER stress associated diseases, such as Parkinson’s disease.
  • Alajoki, Reetta (2023)
    Uterine leiomyomas (ULs) are common benign tumors that originate from the smooth muscle cells of the uterine wall known as the myometrium. Around 70% of pre-menopausal women are affected by these tumors. The high prevalence of ULs is a significant public health issue and ULs are the leading cause for hysterectomy. Many tumors remain asymptomatic, but 15-30% of affected women develop symptoms ranging from pain and heavy menstrual bleeding to pregnancy complications and infertility. Despite their common occurrence, the underlying mechanisms of UL genesis are still largely unknown. Based on mutually exclusive recurring genetic alterations, ULs can be divided into molecular subclasses. Three main molecular subclasses have been established: MED12 mutated tumors, HMGA2 overexpressing tumors and tumors with biallelic FH inactivation. Combined, these three subclasses represent around 90% of ULs, indicating that additional smaller molecular subclasses also exist. Recently, novel mutations associated with ULs have been identified in genes encoding for subunits of the SRCAP chromatin remodeling complex that deposits histone variant H2A.Z onto chromatin. These included loss-of-function mutations in YEATS4, DMAP1 and ZNHIT1, and resulted in deficient H2A.Z loading in the tumors. The detailed functional consequences of these driver mutations need to be further investigated to fully understand their significance in UL genesis. This work aimed to elucidate the effects of YEATS4 mutations by characterizing previously established CRISPR-Cas9 edited immortalized human myometrial cell models carrying heterozygous mutations in YEATS4 using various molecular biology methods. Subcellular fractionation and western blot analysis was used to detect chromatin bound H2A.Z from cell lysates. Quantitative PCR was performed to determine relative YEATS4 expression levels in mutated and wild-type cells. No significant reduction of chromatin bound H2A.Z or YEATS4 expression was observed in the studied heterozygous mutants when compared to wild-type immortalized myometrial smooth muscle cells. Additional myometrial cell models were created by CRISPR-Cas9 gene editing. Objective was to achieve homozygous YEATS4 mutations to better reflect the changes previously reported in ULs. One homozygous YEATS4 mutant cell line was achieved. Understanding the detailed molecular mechanisms behind UL genesis will be instrumental for developing curative non-invasive therapies in the future. Insight into dysregulated pathways and identification of UL biomarkers could improve diagnostic accuracy and help design personalized targeted therapies effective for specific UL subclasses. Characterization of each molecular subclass offers a unique opportunity to understand UL genesis.
  • Hakosalo, Vili (2021)
    Parkinson’s disease (PD) is the second most common neurogenerative disease. There are no drugs available to halt the progression of PD. The glial cell line-derived neurotrophic factor (GDNF) has been identified as a potential drug candidate against PD because of its protective properties on dopaminergic neurons, which are an especially vulnerable cell population in PD. It has been recently shown that GDNF can also attenuate aggregation of phosphorylated α-synuclein in dopaminergic neurons, which is one of the most important pathologies of PD. Phosphorylated α-synuclein is a primary component of Lewy bodies, which in turn, are vastly studied intracellular inclusions with a high correlation towards neurodegenerative diseases. GDNF signals through its main receptor RET and activates downstream signalling cascades. RET is indispensable for the effect of GDNF against α-synuclein aggregation. Importance of the downstream molecules Src, AKT and PI3K have been also pharmacologically demonstrated. However, complete mechanism of GNDF’s action and individual importance of downstream signalling molecules has been yet to establish. CRISPR/Cas9 gene editing tool has revolutionized the gene manipulation in biological research. In this thesis work, CRISPR/Cas9 guides were designed to target and mutate the c-Src, Akt1 and NURR1, which are important proteins of the GDNF/RET pathway. As a delivery system for the Cas9 enzyme and individual guides, lentiviral vectors were produced according to the protocols previously established in our laboratory and proved to be high efficiency. Modelling of α-synuclein aggregation in neurons was performed with pre-formed fibrils of α-synuclein, which induce the formation of intracellular Lewy body-like inclusions with the phosphorylation of α-synuclein at serine 129. In this study, primary dopaminergic neuron cultures from E13.5 mouse embryos were cultured in 96-well plates. For each of the target genes, I designed two guide variants, cloned them in lentiviral transfer vectors and produced lentiviral particles for neuronal transduction. My data shows that targeting Akt1 and c-Src impaired the protective mechanism of GDNF against Lewy body-like inclusions. For the importance of NURR1 more studies are needed for coherent conclusions. I also showed that targeting of NURR1 impaired the GDNF/RET signalling at least in one guide construct. The 15-day long cultivation did not affect to the dopaminergic cell numbers in any of the groups. Still the confirmation of successful CRISPR-induced genetic mutations by sequencing as well as the detailed mechanism of how GDNF prevents the formation of Lewy body-like inclusions will be a subject of future studies. This thesis provides important information for the molecular mechanism of attenuation of α-synuclein aggregation by GDNF through its main receptor RET.
  • Kari, Moisio (2023)
    Animals regulate their metabolism dynamically as a response to changes in nutritional landscape. Intestine is emerging as a key regulator of systemic metabolism. It possesses secretory enteroendocrine cells (EECs), which have a central role in intestinal nutrient sensing and signaling. However, how the number and function of EECs is regulated in response to nutrients remains poorly understood. Previous work in Hietakangas lab has shown that a transcriptional cofactor, C-terminal binding protein (CtBP), regulates the number of EECs in response to sugar feeding and loss of CtBP function in EECs causes sugar intolerance in Drosophila. CtBP’s transcriptional activity is modulated through homodimerization, which is controlled by redox coenzyme NAD+/NADH, whose levels are dependent on sugar metabolism. Therefore, I hypothesise that CtBP is a sugar- and redox-responsive regulator of EEC function. In this thesis, I aimed to understand how CtBP is regulated and what are its downstream effectors. My results show that the formation of CtBP homodimers is responsive to dietary sugars and cellular redox state. In addition, I observed that CtBP heterodimerizes with EEC fate determining transcription factor Prospero. Functional analysis of CtBP downstream effector genes shows significant overlap with those of Prospero. In conclusion, CtBP is a sugar- and redox-responsive cellular regulator of EEC function, which acts in cooperation with Prospero.
  • Kyriacou, Mikael Sakarias (2021)
    MLH1 is a gene that codes for one of the four mismatch repair (MMR) proteins alongside MSH2, MSH6, and PMS2. The main function of the MMR proteins is to recognize base mismatches and insertion-deletion loops formed during DNA replication and aid in their excision. Inherited heterozygous pathogenic variants in any of the four MMR genes lead to Lynch syndrome, an inherited cancer syndrome that predisposes to multiple different cancer types, most notably colorectal cancer. Loss of the expression of an MMR gene causes MMR-deficiency, which leads to microsatellite instability, the accumulation of mutations in microsatellite regions of the DNA. The higher mutational burden caused by MMR-deficiency is thought to be the main driving force of genomic instability and tumorigenesis in MMR-deficient cells. In addition to MMR, MLH1 and the MMR machinery have roles in other anticarcinogenic cellular processes, such as DNA damage signaling and DNA double-strand break repair. Recently, MLH1 has also been shown to have a significant role in regulating mitochondrial metabolism and oxidative stress responses. The identification of MMR-proficient tumors in Lynch syndrome patients begs the question whether the lower amount of functional MLH1 observed in MLH1 mutation carriers could cause problems with these functions and pose alternative routes to tumorigenesis. In line with this, it has been shown that the role of MLH1 in cell cycle regulation in DNA damage signaling is notably more sensitive to decreased amount of the protein compared to its role in MMR. The main goal of the thesis was to study the effects of decreased MLH1 expression on gene expression, cellular functions, and possible alternative tumorigenic pathways. In order to achieve this, the coding transcriptome of human fibroblast cell lines expressing MLH1 at different levels was sequenced and the resulting data analyzed. The study revealed that decreased MLH1 expression affects cellular functions associated with mitochondrial function and oxidative stress responses in cells with functional MMR. Particularly NRF2-controlled cytoprotective defence systems were observed to be downregulated. Decreased MLH1 expression was also observed to affect several cellular functions associated with reorganization of the cytoskeleton and interactions with the extracellular matrix. These results strengthen the recently made notions that MLH1 has a role in controlling the function of mitochondria and in mitigating oxidative stress, and that these two functions are connected. The study also brings to light new information on the possible role of MLH1 in controlling the organization of the cytoskeleton, which has previously received little attention. Dysfunction of mitochondria, increased oxidative stress, and reorganization of the cytoskeleton, as a result of decreased MLH1 expression, could pose events that facilitate malignant transformation of cells prior to the total loss of MMR function.
  • Silfvast, Josetta (2021)
    The signal recognition particle (SRP) targets newly synthesized secretory and membrane proteins from the cytosol to the translocon complex on the endoplasmic reticulum membrane. This highly specific co-translational protein targeting is essential for proteostasis by preventing the accumulation of proteins in the cytosol and the mistargeting of proteins. Defects in the SRP68 and SRP72 subunits of eukaryotic SRP have been linked to various inflammatory muscle diseases such as myopathy and myositis. The full role of these subunits in protein targeting and regulation of targeting is unknown. Previously the yeast SRP72 subunit has been degraded using an auxin-inducible degron (AID) system to explore the effect of depletion on protein targeting and cell viability, but the mammalian SRP72-AID has not yet been studied. The aim of this study was to deplete the mammalian SRP68 and SRP72 subunits using the AID system. This study revealed that in the case of SRP68-AID, approximately 65% of the protein is degraded after 2 hours. Respectively, 75% of SRP72-AID degrades after 2 hours and 85% after 4 hours. However, complete depletion of subunits was not achieved during 24 hours of auxin treatment. Quantification of depletion also showed that the strongest decrease in SRP occurs during the first 2 hours. This study demonstrated that mammalian SRP subunits can be depleted using the AID system, providing a good basis for further research to examine the effect of subunit depletion on protein targeting. This may help to solve the mechanisms of diseases associated with SRP68 and SRP72 defects and to develop therapeutics for them.
  • Lopez Cabezas, Rosa Maria (2022)
    In the past few years, there has been an increased consideration on the stem cell niche as a key factor to regulate stem cell maintenance and differentiation. Research on characterization of the stem cell microenvironment boosted after the determination of long-term three-dimensional (3D) tissue cultures, or so-called organoids. Organoids are derived from stem cells which self-organize in 3D multicellular structures upon embedding in an extracellular matrix mimic, such as Matrigel®. Their main advantage is these structures resemble the architectural distribution of the tissue of origin in vivo. Likewise, the cellular components of organoids vary depending on multiple variables as the tissue of origin and the growth factors they have access to. As a result of advances in this technique, some stem cell niches have been well characterized, as in the case of intestinal stem cells (ISCs), while others remain elusive as in case of the human gastric stem cells (hGSCs). Along with the remarkable development of 3D cultures, the interest of ECM proteins in stem cell regulation increased. Matrigel® is a rich matrix composed of several adhesive proteins such as laminins and collagens. Aside from providing structural support, the extracellular matrix (ECM) proteins forming this matrix contribute to cell adhesion and signalling. However, Matrigel® composition cannot be modified or even well-characterized due to its origin from Engelbreth-Holm-Swarm (EHS) mouse sarcoma cells. Additionally, it has been demonstrated that contains a high batch-to-batch variability. Other techniques to study the effects of individual ECM proteins have been used such as coating of tissue culture plates with ECM proteins. However, the biomechanical properties in this model are far from being physiological. Therefore, although preliminary results can be obtained using this technique, results extrapolation to an in vivo model can be questioned. To date, there is a lack of a reproducible, high-throughput and reliable technique to test the effect of ECM proteins on human gastric stem cells behavior. This Master’s thesis presents a novel transwell device containing a polyethylene glycol (PEG)-based hydrogel enriched with human ECM proteins to test their effect on human gastric stem cell regulation. Preliminary results showed that gastric organoid-derived epithelial cells (GODE) grown on hydrogels with ECM proteins that are localized at base of the gastric glands, such as Laminin-211, had a higher stem cell marker expression than the control grown on ECM proteins that are uniformly localized in vivo. Additionally, when GODE were grown on hydrogels containing ECM proteins that are localized at the surface of the native gastric epithelium, expression of surface gastric mucins markers was enhanced. These preliminary results highlight the utility of the optimized transwell device to further shed light on how the human gastric stem cells are regulated and what is the effect of the ECM proteins surrounding them.
  • Liu, Jianyin (2022)
    Cytokine release syndrome is a severe systematic inflammatory disease that can be triggered upon pharmaceuticals intake. Evaluating the potential risk levels of novel therapeutics with an optimal assay is therefore essential. In this study, we tried to set up and validate a cytokine release assay from human peripheral blood mononuclear cells (PBMCs) for its application in nonclinical immunotoxicity assessments. Fresh PBMCs were isolated from buffy coats obtained from 11 healthy donors of different characteristics. Freshly isolated PBMCs were treated with LPS, positive control antibodies (anti-CD28, anti-CD3) and their corresponding isotypes (negative control antibodies) in both aqueous and solid formats to assess their abilities to induce cytokine release. Similarly, cryopreserved frozen PBMCs were also incubated with LPS, the positive control antibodies and the negative control antibodies, and compared their cytokine releasing capacities with freshly isolated PBMCs. A nine-cytokine panel (IFNγ, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, TNFα, IL-12) was screened to select four cytokines (IFNγ, IL-2, IL-6, TNFα) in the following experimental setup. Freshly isolated PBMCs appeared to have higher sensitivity in response to the treatments as shown by the higher level of cytokine release. However, similar trends of cytokine release were observed between freshly isolated and frozen PBMCs in both aqueous and solid assay formats. LPS and anti-CD3 strongly induced cytokine release in all donors. Conversely, anti-CD28 induced cytokine release in some, but not all donors, possibly due to donor specificity. In summary, we have successfully developed and optimized a cytokine release assay, and it can be used to test the potential risk of immune-modulating drug candidate in the preclinical safety studies.
  • Gómez Sánchez, Celia (2022)
    Kv7.1 is a potassium ion channel comprised of the KCNQ1 protein, which can coassemble with distinct β-subunits modulating the channel functions in different tissues. In 2017, Raivio’s group (from the University of Helsinki) found two missense mutations in the KCNQ1 gene, p.(Arg116Leu) and p.(Pro369Leu), responsible for causing pituitary hormone deficiency and maternally inherited gingival fibromatosis. The facial features and bone structure pointed to a cranial neural crest (CNC)-derived phenotype caused by an alteration in the potassium channel balance, given that these cells form the bone and cartilage of the cranial zone. To understand the implication of the CNC in the KCNQ1 syndrome, I attempted to replicate the CNC differentiation protocol of Suga and Furue (2019) with the aim of obtaining cranial neural crest cells (CNCCs). This would enable future generation of a KCNQ1-related disease model. The differentiation process was carried out thrice, and two BMP4 concentrations (10 and 100 ng/ml) were assayed. The differentiated cells exhibited a CNC-like morphology as well as upregulation of the marker genes (TFAP2A, SOX10, DLX1, MSX1, and DLX2) associated to this cell lineage. However, the gene expression was low according to the qRT-PCR Ct values, which were in most cases higher than 30. Additionally, no differences were found between the two BMP4 treatments. Furthermore, the cells did not express KCNQ1, and thus the impact of the two KCNQ1 mutations was not investigated under this protocol. In conclusion, the protocol had a low efficiency in the generation of CNCCs that was not improved by increasing the BMP4 concentration. Further optimization of the protocol, such as the BMP4 concentration or the cell density of the culture, will be needed to improve its efficiency and obtain an adequate disease model.
  • Ukwattage, Sanjeevi (2019)
    Background- Colorectal cancer (CRC) is the third most common epithelial carcinoma. There is an increased risk of colorectal cancer in people with longstanding inflammation in the large intestine, including individuals with ulcerative colitis (UC). Epigenetic changes in CRC such as aberrant DNA methylation alterations are common changes in human cancer. The aim of this study is to identify the DNA methylation alterations of selected inflammation related genes in UC-CRC vs. Lynch syndrome (LS). Method- DNA was extracted from archival tissue specimens from normal and tumor samples from UC-CRC (n= 31), and LS-CRC (n=29). Methylation-specific multiple ligation-dependent probe amplification (MS-MLPA) assays were used to detect CIMP status and CpG promoter methylation status of seven inflammation related genes. Microsatellite instability analysis was carried out using two mononucleotide repeat markers BAT25 and BAT26. Results- Increased hypermethylation frequencies in carcinoma vs. normal colonic mucosa were detected for all the inflammatory marker genes in specimens of UC-CRC patients. Statistically significant differences for methylation frequencies were observed in the NTSR1 gene (p value =0.008) and SOCS2 gene (p value =0.04) in specimens of UC-CRC patients. NTSR1 gene showed significantly increased methylation of normal colonic mucosae from UC-CRC vs. LS patients (p value=0.01). Conclusion- UC-CRC and LS tumor specimens revealed varying frequencies of hypermethylation in all the inflammatory genes. Methylation of the NTSR1 in the normal colonic mucosa suggests a possible field defect in UC-CRC, and could thus be used as an early biomarker to detect increased UC-CRC risk in non-neoplastic epithelium.
  • Vänttinen, Ida (2020)
    Multiple myeloma (MM) is a heterogeneous plasma cell cancer that results from the excessive proliferation of mutated B cells in the bone marrow and the accumulation of ineffective antibodies, monoclonal proteins, in the blood. Despite recent advances in research and novel therapeutics, MM remains incurable, mainly due to the mechanisms underlying disease progression and drug resistance. Therefore, novel biomarkers and therapeutics for the treatment of relapsed and refractory MM are urgently needed. MicroRNAs (miRNAs), short non-coding RNA molecules that play a key role in post-transcriptional gene regulation, have been found to be associated with different hallmarks of MM. Previous studies have indicated that abnormally functioning miRNA-mediated gene regulation followed by oncogene activation and tumor suppressor gene silencing results in drastic alterations in cell proliferation, apoptosis, growth, and metabolism. These changes in cellular functions have been indicated to be associated with the pathogenesis, progression, and formation of drug resistance in MM. Therefore, the role and potential of miRNAs to act as biomarkers to predict MM progression and drug sensitivity should be further investigated to ultimately improve the survival rates of patients. The aim of this master’s thesis was to investigate the relationships between drug sensitivity, disease progression and miRNA regulation in MM patients. Bioinformatically predicted miRNAs identified to be associated with sensitivity to panobinostat, a novel histone deacetylase inhibitor, and MM progression were validated in MM patient samples by using real-time quantitative reverse transcription PCR (RT-qPCR). In addition, the specific gene targets of miRNAs involved in the regulation of drug responses and MM progression were predicted by identifying statistically significant, negatively correlated interactions between the miRNA and RNA sequencing data of 45 MM patients in pairwise comparative correlation analysis. Finally, the predicted miRNA targets genes were validated in MM patient samples using RT-qPCR. Based on the bioinformatic analyses and RT-qPCR validation, mir-424 expression was significantly increased in relapsed MM patients as compared to respective patient samples taken at diagnosis, suggesting a potential role of mir-424 in MM progression. Similarly, mir-4433b expression was significantly elevated in panobinostat-resistant patients compared to sensitive patients, suggesting a potential effect of mir-4433b on the regulation of panobinostat drug response in MM patients. In addition, the RT-qPCR validation demonstrated that the disease progression and drug sensitivity associated mir-92b, mir-363 and mir-221, would potentially regulate the expression of FGF2, MFF, and TMEM248, respectively, providing novel insights into the functional roles of miRNAs in MM pathways.