Publications by authors named "Lasse Sinkkonen"

Loss-of-function mutations in PARK7, encoding for DJ-1, can lead to early onset Parkinson's disease (PD). In mice, Park7 deletion leads to dopaminergic deficits during aging, and increased sensitivity to oxidative stress. However, the severity of the reported phenotypes varies.

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  • - The study used constraint-based network modeling to analyze metabolic networks at a genomic scale, integrating RNA-seq data with epigenomic data from the EpiATLAS resource across 1,555 samples from 58 tissues and cell types.
  • - The analysis identified both core metabolic processes essential for all cells and unique metabolic functions specific to certain cell types, helping to define the metabolic identity of different human cells and tissues.
  • - By examining enhancer-gene interactions and gene-level chromatin states, the research revealed critical nodes and regulatory points that control metabolism, highlighting how certain pathways are repressed in inactive cell types.
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  • Midbrain dopaminergic neurons (mDANs) are crucial for movement, cognition, and reward, and are linked to conditions like Parkinson's disease.
  • Researchers used a human iPSC reporter line to analyze the differentiation of mDANs and identified new transcription factors (TFs) that influence this process.
  • Key TFs such as LBX1, NHLH1, and NR2F1/2 were found to enhance mDAN differentiation, with specific roles in promoting neuronal microRNAs, regulating cholesterol biosynthesis, and controlling neuronal activity.
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  • 2-Hydroxyglutarate (2-HG) accumulates in some cancers due to mutations in isocitrate dehydrogenase, inhibiting key demethylases and altering gene regulation and chromatin structure.
  • The study explored the impact of elevated 2-HG in a yeast model lacking DNA methylation, revealing that it caused significant gene expression changes linked to specific histone methylation patterns.
  • The findings identified Rph1, a yeast demethylase similar to human KDM4, as particularly sensitive to 2-HG's effects, shedding light on the oncometabolite's broader implications for gene regulation in cancer.
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  • Many patients with metastatic melanoma relapse after initial treatments, highlighting the need for new therapies.
  • Researchers developed a workflow to identify drug targets that can inhibit cancer cell growth without affecting healthy cells.
  • The study identified 28 candidate drugs, tested 12 in melanoma cell lines, and found that combining some of these drugs with existing treatments could enhance their effectiveness.
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Pyruvate dehydrogenase (PDH) is the central enzyme connecting glycolysis and the tricarboxylic acid (TCA) cycle. The importance of PDH function in T helper 17 (Th17) cells still remains to be studied. Here, we show that PDH is essential for the generation of a glucose-derived citrate pool needed for Th17 cell proliferation, survival, and effector function.

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Brain disorders represent 32% of the global disease burden, with 169 million Europeans affected. Constraint-based metabolic modelling and other approaches have been applied to predict new treatments for these and other diseases. Many recent studies focused on enhancing, among others, drug predictions by generating generic metabolic models of brain cells and on the contextualisation of the genome-scale metabolic models with expression data.

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The nuclear factor erythroid 2-related factor 2 (NRF2) was originally described as a master regulator of antioxidant cellular response, but in the time since, numerous important biological functions linked to cell survival, cellular detoxification, metabolism, autophagy, proteostasis, inflammation, immunity, and differentiation have been attributed to this pleiotropic transcription factor that regulates hundreds of genes. After 40 years of in-depth research and key discoveries, NRF2 is now at the center of a vast regulatory network, revealing NRF2 signalling as increasingly complex. It is widely recognized that reactive oxygen species (ROS) play a key role in human physiological and pathological processes such as ageing, obesity, diabetes, cancer, and neurodegenerative diseases.

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Despite remarkable advances in therapeutic interventions, malignant melanoma (MM) remains a life-threating disease. Following high initial response rates to targeted kinase-inhibition metastases quickly acquire resistance and present with enhanced tumor progression and invasion, demanding alternative treatment options. We show 2 generation hexameric TRAIL-receptor-agonist IZI1551 (IZI) to effectively induce apoptosis in MM cells irrespective of the intrinsic BRAF/NRAS mutation status.

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Increasing evidence suggests that neurodevelopmental alterations might contribute to increase the susceptibility to develop neurodegenerative diseases. We investigate the occurrence of developmental abnormalities in dopaminergic neurons in a model of Parkinson's disease (PD). We monitor the differentiation of human patient-specific neuroepithelial stem cells (NESCs) into dopaminergic neurons.

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To establish a workflow for mitochondrial DNA (mtDNA) CpG methylation using Nanopore whole-genome sequencing and perform first pilot experiments on affected biallelic mutation carriers (Parkin-PD) and healthy controls. Mitochondria, including mtDNA, are established key players in Parkinson's disease (PD) pathogenesis. Mutations in Parkin, essential for degradation of damaged mitochondria, cause early-onset PD.

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Background: Cell types in ventral midbrain are involved in diseases with variable genetic susceptibility, such as Parkinson's disease and schizophrenia. Many genetic variants affect regulatory regions and alter gene expression in a cell-type-specific manner depending on the chromatin structure and accessibility.

Results: We report 20,658 single-nuclei chromatin accessibility profiles of ventral midbrain from two genetically and phenotypically distinct mouse strains.

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Autophagy is a highly conserved cellular process in which intracellular proteins and organelles are sequestered and degraded after the fusion of double-membrane vesicles known as autophagosomes with lysosomes. The process of autophagy is dependent on autophagy-related (ATG) proteins. The role of autophagy in cancer is very complex and still elusive.

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Dopaminergic neurons (DA neurons) are controlled by multiple factors, many involved in neurological disease. Parkinson's disease motor symptoms are caused by the demise of nigral DA neurons, leading to loss of striatal dopamine (DA). Here, we measured DA concentration in the dorsal striatum of 32 members of Collaborative Cross (CC) family and their eight founder strains.

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Mounting evidence indicates that immunogenic therapies engaging the unfolded protein response (UPR) following endoplasmic reticulum (ER) stress favor proficient cancer cell-immune interactions, by stimulating the release of immunomodulatory/proinflammatory factors by stressed or dying cancer cells. UPR-driven transcription of proinflammatory cytokines/chemokines exert beneficial or detrimental effects on tumor growth and antitumor immunity, but the cell-autonomous machinery governing the cancer cell inflammatory output in response to immunogenic therapies remains poorly defined. Here, we profiled the transcriptome of cancer cells responding to immunogenic or weakly immunogenic treatments.

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Dopaminergic neurons in the midbrain are of particular interest due to their role in diseases such as Parkinson's disease and schizophrenia. Genetic variation between individuals can affect the integrity and function of dopaminergic neurons but the DNA variants and molecular cascades modulating dopaminergic neurons and other cells types of ventral midbrain remain poorly defined. Three genetically diverse inbred mouse strains - C57BL/6J, A/J, and DBA/2J - differ significantly in their genomes (∼7 million variants), motor and cognitive behavior, and susceptibility to neurotoxins.

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  • Repeated challenges with lipopolysaccharides (LPS) can activate microglia and lead to neurodegeneration in mice, particularly in the substantia nigra region.
  • A study compared Cybb-deficient NOX-2 knockout (KO) mice and wild type (WT) mice, revealing that the KO mice had lower expression of certain microglial phagocytosis-related genes after LPS treatment.
  • The findings suggest that the loss of dopaminergic neurons due to LPS is linked to the activation of specific genes related to microglial function involving NADPH oxidase, particularly the Cybb/gp91phox subunit.
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  • Parkinson's disease (PD) is influenced by both genetic and environmental factors, and a deeper understanding of its genetic architecture is crucial for patient stratification and developing effective treatments.
  • Despite significant research efforts, most of the heritability of PD remains unexplained, with many genetic variants found in non-coding regions of the genome, complicating their functional assessment.
  • The review discusses the role of non-coding genetic variants, their impact on gene regulation, and strategies for identifying disease pathways, highlighting the need for improved diagnostics and targeted therapies in PD.
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Sialic acid-binding Ig-like lectin (Siglec) receptors are linked to neurodegenerative processes, but the role of sialic acids in physiological aging is still not fully understood. We investigated the impact of reduced sialylation in the brain of mice heterozygous for the enzyme glucosamine-2-epimerase/N-acetylmannosamine kinase (GNE+/-) that is essential for sialic acid biosynthesis. We demonstrate that GNE+/- mice have hyposialylation in different brain regions, less synapses in the hippocampus and reduced microglial arborization already at 6 months followed by increased loss of neurons at 12 months.

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Parkinson's disease (PD) is a multifactorial disorder with complex etiology. The most prevalent PD associated mutation, LRRK2-G2019S is linked to familial and sporadic cases. Based on the multitude of genetic predispositions in PD and the incomplete penetrance of LRRK2-G2019S, we hypothesize that modifiers in the patients' genetic background act as susceptibility factors for developing PD.

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Prediction of genes under dynamic post-transcriptional regulation from epigenomic data. We used time-series profiles of chromatin immunoprecipitation-seq data of histone modifications from differentiation of mesenchymal progenitor cells toward adipocytes and osteoblasts to predict gene expression levels at five time points in both lineages and estimated the deviation of those predictions from the RNA-seq measured expression levels using linear regression. The genes with biggest changes in their estimated stability across the time series are enriched for noncoding RNAs and lineage-specific biological processes.

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The microglial triggering receptor expressed on myeloid cells 2 (TREM2) signals via the activatory membrane adaptor molecule TYROBP. Genetic variants or mutations of TREM2 or TYROBP have been linked to inflammatory neurodegenerative diseases associated with aging. The typical aging process goes along with microglial changes and mild neuronal loss, but the exact contribution of TREM2 is still unclear.

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  • Temporal data on gene expression and open chromatin states can enhance the identification of key transcription factors (TFs) and gene regulatory networks (GRNs) involved in cellular differentiation, despite the integration challenges.
  • The study introduces EPIC-DREM, a novel data-driven method that generates time-series profiles from mouse multipotent bone marrow stromal cells (ST2) differentiating into adipocytes and osteoblasts, allowing for the construction of time-resolved GRNs for both cell types.
  • The approach identified AHR and GLIS1 as crucial mesenchymal TFs, regulated by dynamic super-enhancers that suppress their expression during differentiation, indicating their role in controlling lineage commitment in ST2 cells.
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Changes in mature microRNA (miRNA) levels that occur downstream of signaling cascades play an important role during human development and disease. However, the regulation of primary microRNA (pri-miRNA) genes remains to be dissected in detail. To address this, we followed a data-driven approach and developed a transcript identification, validation and quantification pipeline for characterizing the regulatory domains of pri-miRNAs.

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