Biology subjects

Ezer, S.

Publications and source records attributed to Ezer, S..

10 recordsLinked to original sources

bioRxiv2026

Placental cis-eQTL analysis identifies preeclampsia-dependent genetic regulation at promoters

Background: Preeclampsia (PE) is a hypertensive pregnancy disorder with contributions from both maternal and fetal genetic factors, but how both genomes regulate placental transcription remains incompletely understood. Results: We analyzed placental 5'-end RNA sequencing data from 59 pregnancies in the FINNPEC cohort and performed separate maternal and fetal cis-eQTL analyses using gene-level expression and promoter-level expression defined as Transcript Far 5' Ends (TFE). Genotype-by-PE interaction models were used to identify genetic effects that differ according to PE status. No gene-level interaction eQTLs remained significant after multiple-testing correction, although suggestive signals included LILRB2 in the maternal and LPCAT3 in the fetal analyses. In contrast, we identified two significant syntenic promoter-level interaction eQTLs: rs12504642-TFE61820 at the FHDC1 locus in the maternal analysis and rs1557150-TFE9032 at the PPIAP31 locus in the fetal analysis. Conclusion: These findings suggest that PE-dependent genetic interaction effects may be detectable at specific transcript promoter regions even when they are not captured at annotated gene levels.

genetics↗

bioRxiv2026

Allele-specific antisense oligonucleotide treatment rescues atad3-associated phenotype in zebrafish

Pathogenic variants in ATAD3A cause a spectrum of multisystem disorders, with a recurrent dominant-negative variant (c.1582C>T; p.Arg528Trp) associated with neurodevelopmental disease. Given the tolerance of ATAD3A to heterozygous loss of function variants, allele-specific transcript reduction represents a promising therapeutic strategy. We designed and optimized allele-specific antisense oligonucleotides (ASOs) targeting the c.1582C>T transcript and evaluated their efficacy and specificity in affected fibroblasts using allele-specific primers and amplicon-based next generation sequencing. Therapeutic potential was further assessed in vivo in zebrafish embryos expressing human wild-type or mutant ATAD3A transcripts. An optimized gapmer ASO selectively reduced mutant ATAD3A transcripts while relatively sparing the wild-type allele. In addition to RNase H-mediated degradation, the ASO induced exon skipping, leading to degradation of the aberrant transcript without production of a truncated protein. In zebrafish, expression of mutant human ATAD3A in embryos caused developmental abnormalities including reduced eye size, which were robustly rescued by co-injection of the optimized ASO. Our findings provide proof of concept for allele-targeted ASO therapy for dominant-negative ATAD3A variants. This work highlights the therapeutic potential of ASOs for rare dominant disorders involving genes tolerant to heterozygous loss-of-function, and establishes zebrafish as a versatile platform for in vivo ASO optimization.

genetics↗

bioRxiv2026

The DoGA Consortium Atlas of Canine Enhancers and Promoters Across Tissues and Development

The domestic dog is a powerful genetic model for complex traits, disease and behaviours relevant to human biology, yet the canine genome still lacks a systematic transcription-defined atlas of regulatory elements. Existing resources have improved annotation but largely infer regulatory activity from chromatin features rather than directly mapping transcription initiation at promoters and enhancers. Here, we address this gap using 114 CAGE-seq libraries spanning 56 tissues and developmental stages from 9 dogs. We identify 68,446 promoters and 46,661 active enhancers, and define their tissue-enriched activity across the canine body. Regulatory programmes are organized around shared transcription factor motif infrastructures, with prominent enrichment of KLF family motifs across tissues. The cerebellum emerges as a major regulatory hub, showing the highest density of enhancer-promoter interactions among brain regions. During embryogenesis, enhancer activity shifts from early neurodevelopmental patterning programmes, including OTX2 and ZIC1/4, towards regulators of functional maturation and synaptic organization, including AQP4 and NLGN3. Comparative analyses revealed 69 enhancers with highly similar regulatory structures linked to potential orthologous genes in dog and human. Together, these data establish a tissue-resolved transcription-based atlas of the canine regulatory genome that advances functional annotation and improves interpretation of non-coding variation in comparative and disease genomics.

genomics↗

bioRxiv2026

Fast and Slow Gene Expression Changes in Blood Following Acute Social Stress

Social stress is a risk factor for psychiatric disorders and also influences immune function. While it is known that acute social stress impacts the number of immune cells in circulation, the temporal dynamics of stress induced immune-related transcriptional changes in human blood remain unclear. To investigate changes in gene expression, we exposed 26 adults to the Trier Social Stress Test (TSST), and collected blood at baseline, as well as 5, 30, 60 and 90 min after stress. Whole-blood gene expression was profiled using a 5 targeted RNA-sequencing method (STRT). Differential expression was analyzed using linear and cubic models. We observed a total of 54 differentially expressed genes following stress. Fast responses, with a transient peak immediately following stress, were enriched for cytotoxic T cell, NK cell and dendritic cell functions (e.g., GZMB, GNLY, CCL4 and GZMA) and paralleled lymphocyte count changes. In contrast, gradual, linear responses without any evident peak were enriched for neutrophil related genes (e.g., FPR2, PLAUR, CXCR2, AQP9, and QPCT) and did not mirror neutrophil counts, indicating cell intrinsic transcriptional changes. From pathway and transcription factor enrichment analyses, IL-12 family mediated signaling is inferred as a central mechanism linking stress to immune gene regulation. Our results show that acute psychosocial stress induces both fast and slower changes in gene expression in different immune cell populations. The involvement of the IL-12-STAT4 axis and genes such as PLAUR and FPR2 suggests molecular mechanisms through which stress-related immune activation may contribute to vulnerability for anxiety and depressive disorders.

genetics↗

bioRxiv2024

Transcriptome analysis of atad3-null zebrafish embryos elucidates possible disease mechanisms

ATAD3A, a nuclear gene encoding the ATAD3A protein, has diverse roles in mitochondrial processes, encompassing mitochondrial dynamics, mitochondrial DNA maintenance, metabolic pathways and inter-organellar interactions. Pathogenic variants in this gene cause neurological diseases in humans with recognizable genotype-phenotype correlations. To further investigate the gene function and its implication in health and disease, we utilized CRISPR/Cas9 genome editing to generate a knockout (KO) model of the zebrafish ortholog gene, atad3. Analysis of atad3-null zebrafish embryos revealed microcephaly, small eyes, pericardial edema and musculature thinning, closely mirroring with the human rare disease phenotype. Larvae exhibited delayed hatching and embryonic lethality by 13 days post-fertilization (dpf). Locomotor activity, ATP content, mitochondrial content, and mitochondrial activity were all reduced in the mutant embryos. Transcriptome analysis at 3 dpf via RNA-sequencing indicated decline in most mitochondrial pathways, accompanied by a global upregulation of cytosolic tRNA synthetases, presumably secondary to mitochondrial stress and possibly endoplasmic reticulum (ER)-stress. Differential expression of select genes was corroborated in fibroblasts from an affected individual. The atad3-null zebrafish model emerges as a reliable representation of human ATAD3A-associated disorders, with similarities in differentially expressed pathways and processes. Furthermore, our study underscores mitochondrial dysfunction as the primary underlying pathogenic mechanism in ATAD3A-associated disorders and identifies potential readouts for therapeutic studies.

genetics↗

bioRxiv2023

Primary cilia promote the differentiation of human neurons through the WNT signaling pathway

Primary cilia emanate from most human cell types, including neurons. Cilia are important for communicating with the cells immediate environment: signal reception and transduction to/from the ciliated cell. Deregulation of ciliary signaling can lead to ciliopathies and certain neurodevelopmental disorders. In the developing brain cilia play well-documented roles for the expansion of the neural progenitor cell pool, while information about the roles of cilia during post-mitotic neuron differentiation and maturation is scarce. We employed ciliated Lund Human Mesencephalic (LUHMES) cells in time course experiments to assess the impact of ciliary signaling on neuron differentiation. By comparing ciliated and non-ciliated neuronal precursor cells and neurons in wild type and a mutant with altered cilia (RFX2 -/-), we discovered an early-differentiation "ciliary time window" during which transient cilia promote axon outgrowth, branching and arborization. Cilia promote neuron differentiation by tipping WNT signaling toward the non-canonical pathway, in turn activating WNT pathway output genes implicated in cyto-architectural changes. We provide a mechanistic entry point into when and how ciliary signaling coordinates, promotes and translates into anatomical changes. We hypothesize that ciliary alterations causing neuron differentiation defects may result in "mild" impairments of brain development, possibly underpinning certain aspects of neurodevelopmental disorders.

neuroscience↗

bioRxiv2020

Ectopic histone clipping in the mouse model of progressive myoclonus epilepsy

We establish cystatin B (CSTB) as a regulator of histone H3 tail clipping in murine neural progenitor cells (NPCs) and provide evidence suggesting that epigenetic dysregulation contributes to the early pathogenesis in brain disorders associated with deficient CSTB function. We show that NPCs undergo regulated cleavage of the N-terminal tail of histone H3 at threonine 22 (H3T22) transiently upon induction of differentiation. CSTB-deficient NPCs present premature activation of H3T22 clipping during self-renewal mediated by increased activity of cathepsins L and B. During differentiation, the proportion of immature committed neurons undergoing H3T22 clipping is significantly higher in CSTB-deficient than in wild-type NPCs, with no observable decline within 12 days post-differentiation. CSTB-deficient NPCs exhibit significant transcriptional changes highlighting altered expression of nuclear-encoded mitochondrial genes. These changes are associated with significantly impaired respiratory capacity of differentiating NPCs devoid of CSTB. Our data expand the mechanistic understanding of diseases associated with CSTB deficiency.

pathology↗

bioRxiv2020

Differentiation of ciliated human midbrain-derived LUHMES neurons

Many human cell types are ciliated, including neural progenitors and differentiated neurons. Ciliopathies are characterized by defective cilia and comprise various disease states, including brain phenotypes, where the underlying biological pathways are largely unknown. Our understanding of neuronal cilia is rudimentary and an easy-to-maintain, ciliated human neuronal cell model is missing. LUHMES is a ciliated neuronal cell line derived from human fetal mesencephalon. LUHMES cells can easily be maintained and differentiated into mature, functional neurons within one week. They have a single primary cilium as proliferating progenitor cells and as post-mitotic, differentiating neurons. These developmental stages are completely separable within one day of culture condition change. The Sonic Hedgehog (SHH) signaling pathway is active in differentiating LUHMES neurons. RNA-seq time course analyses reveal molecular pathways and gene-regulatory networks critical for ciliogenesis and axon outgrowth at the interface between progenitor cell proliferation, polarization and neuronal differentiation. Gene expression dynamics of cultured LUHMES neurons faithfully mimic the corresponding in vivo dynamics of human fetal midbrain. In LUHMES, neuronal cilia biology can be investigated along a complete timeline: from proliferation through differentiation to mature neurons. Summary StatementWith LUHMES, a ciliated human neuronal cell model, the underlying "neurobiology" of cilia and ciliopathies can be investigated along a complete time line: from proliferation through differentiation to mature neurons.

neuroscience↗

bioRxiv2019

Balancing Selection at HLA-G Modulates Fetal Survival, Preeclampsia and Human Birth Sex Ratio

The population sex ratio is thought to be maintained through balancing selection on rare phenotypes. However, empirical evidence for genetic influence has thus far proven elusive. We combined 1000 Genomes data and large cohorts to study human sex ratios. We found underrepresentation of male offspring in preeclampsia, a serious pregnancy disorder with uncertain pathogenesis. Genetic variation of fetal human leukocyte antigen G (HLA-G), regulating maternal anti-fetal immune responses, was found to be under balancing selection. Sex-linked downregulation of HLA-G and upregulation of interferon alpha-1 (IFNA1) expression contribute to loss of fetal immunotolerance in preeclampsia and suggest hydroxychloroquine as a treatment option. Our findings indicate that an evolutionary trade-off between fetal immunotolerance and protection against infections promotes genetic diversity in HLA-G, thereby maintaining human sex ratios. One Sentence SummaryFetal HLA-G modulates human sex ratio.

evolutionary biology↗

bioRxiv2019

DUX4 regulates oocyte to embryo transition in human

During the human oocyte-to-embryo transition, the fertilized oocyte undergoes final maturation and the embryo genome is gradually activated during the first three cell divisions. How this transition is coordinated in humans is largely unknown. We show that the double homeodomain transcription factor DUX4 contributes to this transition. DUX4 knockdown in human zygotes caused insufficient transcriptome reprogramming as observed three days after fertilization. Induced DUX4 expression in human embryonic stem cells activated transcription of thousands of newly identified bi-directional transcripts, including putative enhancers for embryonic genome activation genes such as LEUTX. DUX4 protein interacted with transcriptional modifiers that are known to couple enhancers and promoters. Taken together, our results reveal that DUX4 is a pioneer regulating oocyte-to-embryo transition in human through activation of intergenic genome, especially enhancers, and hence setting the stage for early human embryo development.

developmental biology↗