Molecular Pathology of Myotonic Dystrophy Type 1 in Iceland.

Background: Myotonic Dystrophy type 1 (DM1) is an autosomal dominant disease with anticipation due to increased number of CTG repeats in the DMPK gene.

Methods: This retrospective, cohort study in Iceland assessed prevalence of DM1, molecular pathology, and patient ascertainment. Data was collected from all major hospitals in Iceland, Medical Director of Health, and independent clinics.

Generation and characterization of inducible KRAB-dCas9 iPSCs from primates for cross-species CRISPRi.

Comparisons of molecular phenotypes across primates provide unique information to understand human biology and evolution, and single-cell RNA-seq CRISPR interference (CRISPRi) screens are a powerful approach to analyze them. Here, we generate and validate three human, three gorilla, and two cynomolgus iPS cell lines that carry a dox-inducible KRAB-dCas9 construct at the AAVS1 locus. We show that despite variable expression levels of KRAB-dCas9 among lines, comparable downregulation of target genes and comparable phenotypic effects are observed in a single-cell RNA-seq CRISPRi screen.

Peripheral priming induces plastic transcriptomic and proteomic responses in circulating neutrophils required for pathogen containment.

Neutrophils rapidly respond to inflammation and infection, but to which degree their functional trajectories after mobilization from the bone marrow are shaped within the circulation remains vague. Experimental limitations have so far hampered neutrophil research in human disease. Here, using innovative fixation and single-cell-based toolsets, we profile human and murine neutrophil transcriptomes and proteomes during steady state and bacterial infection.

Generation and characterization of two Vervet monkey induced pluripotent stem cell lines derived from fibroblasts.

Cross-species comparisons using pluripotent stem cells from primates are crucial to better understand human biology, disease, and evolution. The Vervet monkey (Chlorocebus aethiops sabaeus) serves as an important primate model for such studies, and therefore we reprogrammed skin fibroblasts derived from a male and a female individual, resulting in two induced pluripotent stem cell lines (iPSCs). These iPSCs display the characteristic ESC-like colony morphology, express key pluripotency markers, and possess the ability to differentiate into cells representing all three germ layers.

Generation and characterization of two fibroblast-derived Baboon induced pluripotent stem cell lines.

Cross-species comparisons studying primate pluripotent stem cells and their derivatives are crucial to better understand the molecular and cellular mechanisms behind human disease and development. Within this context, Baboons (Papio anubis) have emerged as a prominent primate model for such investigations. Herein, we reprogrammed skin fibroblasts of one male individual and generated two induced pluripotent stem cell (iPSC) lines, which exhibit the characteristic ESC-like morphology, demonstrated robust expression of key pluripotency factors and displayed multilineage differentiation potential.

Targeting a cell-specific microRNA repressor of CXCR4 ameliorates atherosclerosis in mice.

The CXC chemokine receptor 4 (CXCR4) in endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) is crucial for vascular integrity. The atheroprotective functions of CXCR4 in vascular cells may be counteracted by atherogenic functions in other nonvascular cell types. Thus, strategies for cell-specifically augmenting CXCR4 function in vascular cells are crucial if this receptor is to be useful as a therapeutic target in treating atherosclerosis and other vascular disorders.

Changes to hypothalamic volume and associated subunits during gender-affirming hormone therapy.

Background: Among its pleiotropic properties, gender-affirming hormone therapy (GHT) affects regional brain volumes. The hypothalamus, which regulates neuroendocrine function and associated emotional and cognitive processes, is an intuitive target for probing GHT effects. We sought to assess changes to hypothalamus and hypothalamic subunit volumes after GHT, thereby honouring the region's anatomical and functional heterogeneity.

Detection of phenotype-specific therapeutic vulnerabilities in breast cells using a CRISPR loss-of-function screen.

Cellular phenotype plasticity between the epithelial and mesenchymal states has been linked to metastasis and heterogeneous responses to cancer therapy, and remains a challenge for the treatment of triple-negative breast cancer (TNBC). Here, we used isogenic human breast epithelial cell lines, D492 and D492M, representing the epithelial and mesenchymal phenotypes, respectively. We employed a CRISPR-Cas9 loss-of-function screen targeting a 2240-gene 'druggable genome' to identify phenotype-specific vulnerabilities.

Expression of ncRNAs on the DLK1-DIO3 Locus Is Associated With Basal and Mesenchymal Phenotype in Breast Epithelial Progenitor Cells.

Epithelial-to-mesenchymal transition (EMT) and its reversed process mesenchymal-to-epithelial transition (MET) play a critical role in epithelial plasticity during development and cancer progression. Among important regulators of these cellular processes are non-coding RNAs (ncRNAs). The imprinted DLK1-DIO3 locus, containing numerous maternally expressed ncRNAs including the lncRNA maternally expressed gene 3 () and a cluster of over 50 miRNAs, has been shown to be a modulator of stemness in embryonic stem cells and in cancer progression, potentially through the tumor suppressor role of .

Application of the D492 Cell Lines to Explore Breast Morphogenesis, EMT and Cancer Progression in 3D Culture.

The human female breast gland is composed of branching epithelial ducts that extend from the nipple towards the terminal duct lobular units (TDLUs), which are the functional, milk-producing units of the gland and the site of origin of most breast cancers. The epithelium of ducts and TDLUs is composed of an inner layer of polarized luminal epithelial cells and an outer layer of contractile myoepithelial cells, separated from the vascular-rich stroma by a basement membrane. The luminal- and myoepithelial cells share an origin and in recent years, there has been increasing understanding of how these cell types interact and how they contribute to breast cancer.

MiR-203a is differentially expressed during branching morphogenesis and EMT in breast progenitor cells and is a repressor of peroxidasin.

MicroRNAs regulate developmental events such as branching morphogenesis, epithelial to mesenchymal transition (EMT) and its reverse process mesenchymal to epithelial transition (MET). In this study, we performed small RNA sequencing of a breast epithelial progenitor cell line (D492), and its mesenchymal derivative (D492M) cultured in three-dimensional microenvironment. Among the most downregulated miRNAs in D492M was miR-203a, a miRNA that plays an important role in epithelial differentiation.

Inhibition of PTP1B disrupts cell-cell adhesion and induces anoikis in breast epithelial cells.

Protein tyrosine phosphatase 1B (PTP1B) is a well-known inhibitor of insulin signaling pathways and inhibitors against PTP1B are being developed as promising drug candidates for treatment of obesity. PTP1B has also been linked to breast cancer both as a tumor suppressor and as an oncogene. Furthermore, PTP1B has been shown to be a regulator of cell adhesion and migration in normal and cancer cells.

Epithelial Plasticity During Human Breast Morphogenesis and Cancer Progression.

Understanding the complex events leading to formation of an epithelial-based organ such as the breast requires a detailed insight into the crosstalk between epithelial and stromal compartments. These interactions occur both through heterotypic cellular interactions and between cells and matrix components. While in vivo models may partially capture these complex interactions, there is a need for in- vitro models to study these events.

EGFR Signal-Network Reconstruction Demonstrates Metabolic Crosstalk in EMT.

Epithelial to mesenchymal transition (EMT) is an important event during development and cancer metastasis. There is limited understanding of the metabolic alterations that give rise to and take place during EMT. Dysregulation of signalling pathways that impact metabolism, including epidermal growth factor receptor (EGFR), are however a hallmark of EMT and metastasis.

Association of DNA Methylation Differences With Schizophrenia in an Epigenome-Wide Association Study.

Importance: DNA methylation may play an important role in schizophrenia (SZ), either directly as a mechanism of pathogenesis or as a biomarker of risk.

Objective: To scan genome-wide DNA methylation data to identify differentially methylated CpGs between SZ cases and controls.

Design, Setting, And Participants: Epigenome-wide association study begun in 2008 using DNA methylation levels of 456 513 CpG loci measured on the Infinium HumanMethylation450 array (Illumina) in a consortium of case-control studies for initial discovery and in an independent replication set.

MicroRNA-200c-141 and ∆Np63 are required for breast epithelial differentiation and branching morphogenesis.

The epithelial compartment of the breast contains two lineages, the luminal- and the myoepithelial cells. D492 is a breast epithelial cell line with stem cell properties that forms branching epithelial structures in 3D culture with both luminal- and myoepithelial differentiation. We have recently shown that D492 undergo epithelial to mesenchymal transition (EMT) when co-cultured with endothelial cells.

Functional Role of the microRNA-200 Family in Breast Morphogenesis and Neoplasia.

Branching epithelial morphogenesis is closely linked to epithelial-to-mesenchymal transition (EMT), a process important in normal development and cancer progression. The miR-200 family regulates epithelial morphogenesis and EMT through a negative feedback loop with the ZEB1 and ZEB2 transcription factors. miR-200 inhibits expression of ZEB1/2 mRNA, which in turn can down-regulate the miR-200 family that further results in down-regulation of E-cadherin and induction of a mesenchymal phenotype.

Common DNA methylation alterations in multiple brain regions in autism.

Autism spectrum disorders (ASD) are increasingly common neurodevelopmental disorders defined clinically by a triad of features including impairment in social interaction, impairment in communication in social situations and restricted and repetitive patterns of behavior and interests, with considerable phenotypic heterogeneity among individuals. Although heritability estimates for ASD are high, conventional genetic-based efforts to identify genes involved in ASD have yielded only few reproducible candidate genes that account for only a small proportion of ASDs. There is mounting evidence to suggest environmental and epigenetic factors play a stronger role in the etiology of ASD than previously thought.

Euchromatin islands in large heterochromatin domains are enriched for CTCF binding and differentially DNA-methylated regions.

Background: The organization of higher order chromatin is an emerging epigenetic mechanism for understanding development and disease. We and others have previously observed dynamic changes during differentiation and oncogenesis in large heterochromatin domains such as Large Organized Chromatin K (lysine) modifications (LOCKs), of histone H3 lysine-9 dimethylation (H3K9me2) or other repressive histone posttranslational modifications. The microstructure of these regions has not previously been explored.

Increased methylation variation in epigenetic domains across cancer types.

Tumor heterogeneity is a major barrier to effective cancer diagnosis and treatment. We recently identified cancer-specific differentially DNA-methylated regions (cDMRs) in colon cancer, which also distinguish normal tissue types from each other, suggesting that these cDMRs might be generalized across cancer types. Here we show stochastic methylation variation of the same cDMRs, distinguishing cancer from normal tissue, in colon, lung, breast, thyroid and Wilms' tumors, with intermediate variation in adenomas.

Chip-based mtDNA mutation screening enables fast and reliable genetic diagnosis of OXPHOS patients.

Purpose: Oxidative phosphorylation is under dual genetic control of the nuclear and the mitochondrial DNA (mtDNA). Oxidative phosphorylation disorders are clinically and genetically heterogeneous, which makes it difficult to determine the genetic defect, and symptom-based protocols which link clinical symptoms directly to a specific gene or mtDNA mutation are falling short. Moreover, approximately 25% of the pediatric patients with oxidative phosphorylation disorders is estimated to have mutations in the mtDNA and a standard screening approach for common mutations and deletions will only explain part of these cases.

A case of ethylmalonic encephalopathy with atypical clinical and biochemical presentation.

A child is reported presenting with a clinical picture suggestive of genetic connective tissue disorders (vascular fragility, articular hyperlaxity, delayed motor development, and normal cognitive development), an absence of pathological ethylmalonic acid excretion during inter-critical phases and a homozygous R163W mutation in the ETHE1 gene. This case suggests that ethylmalonic aciduria is not a constant biochemical marker of ethylmalonic encephalopathy and that its normal excretion outside of metabolic decompensation episodes does not exclude this metabolic disease.

ETHE1 mutations are specific to ethylmalonic encephalopathy.

Mutations in ETHE1, a gene located at chromosome 19q13, have recently been identified in patients affected by ethylmalonic encephalopathy (EE). EE is a devastating infantile metabolic disorder, characterised by widespread lesions in the brain, hyperlactic acidaemia, petechiae, orthostatic acrocyanosis, and high levels of ethylmalonic acid in body fluids. To investigate to what extent ETHE1 is responsible for EE, we analysed this gene in 29 patients with typical EE and in 11 patients presenting with early onset progressive encephalopathy with ethylmalonic aciduria (non-EE EMA).