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Kuure, S.

Publications and source records attributed to Kuure, S..

11 recordsLinked to original sources

'broadSeq', a benchmarking tool to contrast differential gene expression methods and identify when genomic neighbourhood matters

Several tools are available to detect differential gene expression. The predominant approach of different statistical methods is to consider changes in gene expression independent from their genomic context. Previously, DELocal was introduced that takes into consideration gene expression dynamics in the genomic neighbourhood. Whereas DELocal was shown to identify developmentally regulated genes in developing mouse tooth, its performance in other biological conditions remains undetermined. To benchmark DElocal together with other methods, we develop another tool 'broadSeq'. It provides easy to use interface for methods like DELocal , deseq2, limma, edger, EBSeq and many more. Here we report benchmarking results on different data sets that comprise wild type developing mouse organs from different embryonic time points, and also human cancer data. The examined datasets are from the heart, kidney, liver, brain, forebrain, and hindbrain. We found that most methods produce relatively comparable lists of differentially expressed genes. Nevertheless, DELocal identifies partially distinct sets of genes compared to the other methods. Evaluating the identified genes using gene and disease ontology terms show that the uniquely detected genes by DELocal are biologically relevant and also highly expressed compared to the genes identified by the other methods. Because consistently highly expressed genes show relatively subtle fold changes, the neighbourhood concept of DELocal appears to correct for the difficulty in detecting these differential expression of highly expressed genes. Finally, we provide the tools as combined bioconductor packages, allowing researchers to explore and decide the best methods for their data and questions.

bioinformatics↗

Human models of GLE1 associated LCCS1 reveal neural crest deficiency and multisystem developmental failure accompanied by altered RNA metabolism

Lethal congenital contracture syndrome 1 (LCCS1) is a neurodevelopmental disorder caused by GLE1 c.432-10A>G variant and presenting fetal akinesia, defects in anterior horn spinal cord, skin, skull, and skeletal muscle development. The uniform prenatal lethality of LCCS1 limits access to patient material, thereby hindering mechanistic studies in physiologically relevant models. To overcome this, human embryonic stem cells (hESCs) carrying the LCCS1 variant, patient-derived fetal fibroblasts, and transcriptomic and proteomic profiling were utilized to examine early GLE1 dysfunction in human cells and tissues. Across LCCS1 cell types, reduced global transcription and translation were observed, while nucleocytoplasmic poly(A)+ RNA distribution was unchanged. Despite its context-dependent effects on proliferation, LCCS1 variant altered mRNA decay kinetics and increased stress granule formation in differentiated cells. LCCS1 hESCs retained core pluripotency but reduced choline acetyltransferase and {beta} tubulin III levels, together with increased neurofilament inclusion incidence, indicate functional immaturity in differentiated spinal motor neurons. Differentiation of LCCS1 hESC-derived gastruloids uncovered broad perturbations in neuromuscular and neural crest derivative development, results which were supported by phenotypes detected in ectodermal organoids and fetal LCCS1 tissue. These findings provide new mechanistic insight into LCCS1 pathogenesis and establish a robust human model framework for studying neurodevelopmental disorders.

developmental biology↗

Novel Cln8 p.R24G mouse line replicates major clinical features of Northern epilepsy

RationaleNorthern epilepsy belongs to a group of genetically diverse lysosomal storage diseases, the neuronal ceroid lipofuscinoses (NCLs). A characteristic feature of NCL pathology is the accumulation of autofluorescent ceroid lipofuscin in the central nervous system. Northern epilepsy is a late-infantile-onset disease. Patients develop normally until 5-10 years old, when they first present with general tonic-clonic seizures, followed by progressive cognitive impairment and a decline in motor skills. Northern epilepsy is caused by a missense variant in CLN8, causing a p.R24G amino acid substitution. CLN8 deficiency has been studied traditionally using motor neuron degeneration (mnd) mice, which carry a spontaneous frame shift variant in the murine orthologue Cln8, which is not known to exist in humans. MethodsWe have generated the first Cln8 p.R24G mouse model (Cln8R24G) using CRISPR/Cas9. Phenotyping analysis of the mice was conducted using behavioral and histopathological studies focusing on the brain and retina. ResultsAt birth, Cln8R24G KI mice were viable and asymptomatic. As the mice aged, a progressive accumulation of autofluorescent ceroid lipofuscin containing the mitochondrial ATP synthase subunit C was evident in different brain regions and retinal layers. Health monitoring revealed that mutant mice developed progressive but mild motor symptoms around 7 months of age. Spontaneous epileptic seizures, like those observed in Northern epilepsy patients, were detected and recorded. An increase in FosB staining intensity, reflecting neuronal hyperactivity, was observed in hippocampal CA1-CA3 pyramidal and dentate granule cells and correlated well with the intensity of seizure activity. Neuroinflammation was evident at 4 months and increased dramatically with age, mainly in the thalamic VPN/VPL nuclei and moderately in the cortex. Neurodegeneration was most prominent in the VPN/VPL thalamic nuclei. ConclusionsWe have generated the Cln8R24G mouse model that genocopies, for the first time, the pathogenic CLN8 variant present in patients with Northern epilepsy. These mice phenocopy major clinical features of the human disease, including mild motor impairment and, unlike the mnd mice, spontaneous generalized tonic-clonic seizures. We hypothesize that our mouse model will open new possibilities for developing and testing targeted treatment options for Northern epilepsy and, more broadly, for early-onset neurodegenerative disorders associated with epilepsy.

neuroscience↗

Testosterone exposure during fetal masculinization programming window determines the kidney size in adult mice.

Kidney size is sex-dimorphic and regulated by androgens in adult humans and mice. However, the effects of developmental androgen deficiency on kidneys remain elusive. We hypothesized that androgens program future kidney growth during a fetal development. Male mice lacking main testosterone-producing enzyme HSD17B3 had reduced testosterone at embryonic day 15.5, but the concentrations increased by E18.5, creating a short time window of androgen deficiency resulting in reduced kidney size in adult males. In male Hsd17b3-/-kidneys, nephron development was qualitatively normal, but number of glomeruli and proliferation of proximal tubules was reduced. Testosterone supplementation at E14.5-17.5 normalized the renal size in adult Hsd17b3-/-males. Our data suggests that androgen receptor and Hnf4a jointly regulate Igfbp5, FOXO1 and mTOR signaling to convey male-specific kidney growth. In conclusion, we have identified a novel developmental programming effect on male kidneys, where fetal androgen deficiency reduces kidney growth and androgen responsiveness in adult males.

developmental biology↗

GLE1 dysfunction compromises cellular homeostasis, spatial organization, and peripheral axon branching

The GLE1 protein is an enigmatic factor of RNA processing, associated with multiple developmental disorders including lethal congenital contracture syndrome 1 (LCCS1). Using in vivo genetic engineering to study disturbed GLE1 functions under physiological conditions we demonstrate that inactivation of Gle1 impedes cellular function and organization and causes pre-gastrulation lethality due to defects in adhesion and lineage specification. In contrast, the knock-in mice genocopying LCCS1-associated GLE1FinMajor variant (Gle1PFQ/PFQ) survive prenatal period but die suddenly at mid-adulthood. Gle1PFQ/PFQ mice present irregular count and distribution of spinal motor neurons and impaired development of neural crest-derived tissues as demonstrated by defects in their sympathetic innervation of heart ventricles, paravertebral sympathetic ganglia volume, and adrenal chromaffin cell counts. Unlike previously reported for yeast and HeLa cells, analysis of molecular consequences of GLE1FinMajor variant identified normal poly(A)+ RNA distribution in Gle1PFQ/PFQ cells, which however were impaired in RNA and protein synthesis and simultaneously showed typical signs of cellular senescence. Gle1PFQ/PFQ also induced disturbed stress responses with significant changes in G3BP1-positive stress granule count. Our results show necessity of GLE1 functions for life and indicate that LCCS1 etiology is resultant of pathogenic GLE1FinMajor variant impinging differentiation of neural crest derivatives and leading to complex multiorgan defects. HighlightsO_LITotal inactivation of GLE1 results in disorganization of blastocyst inner cell mass and early embryonic lethality. C_LIO_LIThe Gle1 knock-in (KI) mice, which genocopy the human GLE1FinMajor variant causative for lethal congenital contracture syndrome 1 (LCCS1), die suddenly in mid-adulthood. C_LIO_LINormal poly(A)+ RNA distribution was observed in Gle1 KI cells, but decreased number of G3BP1-positive stress granules were detected in response to stress. C_LIO_LIAbnormal sympathetic innervation of heart ventricles was detected in Gle1 KI mice. C_LIO_LINeural crest-derived tissues represent a new target of GLE1FinMajor and GLE1-related disorders. C_LI

developmental biology↗

Restoration of mitochondrial complex III function in hepatocytes highlights the liver as a key thermogenic organ independent of brown adipocyte activation

Liver is the key hub of systemic energy metabolism and growth regulation, yet its roles in mitochondrial disease pathophysiology remain relatively understudied. Bcs1lp.S78G knock-in mice, carrying a patient mutation causing respiratory complex III (CIII)-deficiency, present juvenile-onset liver and kidney disease, growth restriction, lipodystrophy, and early death. We restored CIII function in the hepatocytes of these mice using recombinant adeno-associated viral vectors (rAAVs) expressing wild-type Bcs1l. A single intraperitoneal injection of rAAVs into presymptomatic juvenile mice prevented liver disease, improved hypoglycemia and growth, normalized hepatic fuel utilization, and doubled the survival. The mutant mice showed hypothermia and brown adipose tissue (BAT) inflammation, and lacked BAT activation basally and upon acute cold challenge. Disrupted foot pad innervation suggested sensory neuropathy and impaired thermosensation as a contributor to the BAT inactivity. Surprisingly, the rAAV-treated mice maintained near-normal body temperature without significant effect on BAT. Increasing cellular respiration via transgenic alternative oxidase (AOX) was sufficient to prevent the hypothermia. The CIII-deficient mice did not reach euthermia until at an ambient temperature of 35{degrees}C, housing at which relieved metabolic stress and ameliorated hepatocyte senescence. We conclude that mitochondrial respiration in hepatocytes is essential for euthermia in mice. Our findings highlight the crucial role of the liver in thermoregulation, hypothermia as a consequence of mitochondrial dysfunction, and the therapeutic potential of rAAV-based gene delivery in a preclinical model of a multiorgan mitochondrial disease. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=150 HEIGHT=200 SRC="FIGDIR/small/612616v2_ufig1.gif" ALT="Figure 1"> View larger version (38K): org.highwire.dtl.DTLVardef@1cc59ecorg.highwire.dtl.DTLVardef@1239b01org.highwire.dtl.DTLVardef@95697eorg.highwire.dtl.DTLVardef@140fa94_HPS_FORMAT_FIGEXP M_FIG C_FIG

physiology↗

Biomechanical regulation of cell shapes promotes branching morphogenesis of the ureteric bud epithelium

BackgroundBranching morphogenesis orchestrates organogenesis in many tissues including kidney, where ureteric bud branching determines kidney size and nephron number. Defects in branching morphogenesis result in congenital renal anomalies which manifest as deviations in size, function, and nephron number thus critically compromising the lifelong renal functional capacity established during development. Advances in the genetic and molecular understanding of ureteric bud branching regulation have proved insufficient to improve prognosis of congenital renal defects. Thus, we addressed mechanisms regulating three-dimensional (3D) ureteric bud epithelial cell morphology and cell shape changes during novel branch initiation to uncover the contributions of cellular mechanics on cellular functions and tissue organization in normal and branching-compromised bud tips. MethodsWe explored epithelial cell behavior at all scales by utilizing a combination of mouse genetics and a custom machine-learning segmentation pipeline in MATLAB. Ureteric bud epithelial cell shapes and sizes were quantified in 3D wholemount kidneys. A combination with live imaging of fluorescently labelled UB cells, traction force microscopy, and primary UB cells were used to determine how basic cellular features and niche biomechanics contribute to complex novel branch point determination in the process that aims at gaining optimal growth and epithelial density in a limited space. ResultsMachine learning-based segmentation of tip epithelia identified geometrical round-to-elliptical transformation as a key cell shape change facilitating shifts in growth direction that enable propitious branching complexity. Cell shape and molecular analyses in branching-compromised epithelia demonstrated a failure to condense cell size and conformation. Analysis of branching-compromised ureteric bud derived epithelial cells demonstrated disrupted E-CADHERIN and PAXILLIN mediated adhesive forces and defective cytoskeletal dynamics as detected by fluorescent labelling of actin in primary ureteric bud epithelial cells. Branching-compromised ureteric bud epithelial cells showed wrinkled nuclear shapes and alterations in MYH9-based microtubule organization, which suggest a stiff cellular niche with disturbed sensing of and response to biomechanical cues. ConclusionsOur results indicate that the adhesive forces within the epithelium and towards the niche composed of nephron progenitors must dynamically fluctuate to allow complexity in arborization during new branch formation. The data collectively propose a model where epithelial cell crowding in tandem with stretching transforms individual cells into elliptical and elongated shapes. This creates local curvatures that drive new branch formation during the ampulla-to-asymmetric ampulla transition of ureteric bud.

developmental biology↗

Unraveling the principles of mammary gland branching morphogenesis

Branching morphogenesis is a characteristic feature of many essential organs such as the lung, kidney, and most glands, and the net result of two tissue behaviors: branch point initiation and elongation. Each branched organ has a distinct architecture customized to its physiological function, but how patterning occurs in these ramified tubular structures is a fundamental problem of development. Here we use quantitative 3D morphometrics, time-lapse imaging, manipulation of ex vivo cultured embryonic organs, and mice deficient in the planar cell polarity component Vangl2 to address this question in the developing mammary gland. Our results show that the embryonic epithelial trees are highly complex in topology owing to the flexible use of two distinct modes of branch point initiation: lateral branching and tip bifurcation. This non-stereotypy was contrasted by the remarkably constant average branch frequency indicating a ductal growth-invariant, yet stochastic propensity to branch. The probability to branch was malleable and could be tuned by manipulating the Fgf10 and Tgf-{beta}1 pathways. Finally, our in vivo and ex vivo time-lapse imaging suggested the involvement of tissue rearrangements in mammary branch elongation.

developmental biology↗

FGF8 induces chemokinesis and regulates condensation of mouse nephron progenitor cells

Kidneys develop via iterative branching of the ureteric epithelial tree and subsequent nephrogenesis at the branch points. Nephrons form in the cap mesenchyme as the metanephric mesenchyme (MM) condenses around the epithelial ureteric buds (UBs). Previous work demonstrated that FGF8 is important for the survival of nephron progenitor cells (NPCs), and early deletion of Fgf8 leads to the cessation of nephron formation, which results in post-natal lethality. We now reveal a novel function of FGF8. By combining transgenic mouse models, quantitative imaging assays, and data-driven computational modelling, we show that FGF8 has a strong chemokinetic effect and that this chemokinetic effect is important for the condensation of NPCs to the UB. The computational model shows that the motility must be lower close to the UB to achieve NPC attachment. We conclude that the FGF8 signalling pathway is crucial for the coordination of NPCs behaviour to the UB. Chemokinetic effects have been described also for other FGFs and may be relevant more generally for the formation of mesenchymal condensations.

developmental biology↗

Omics profiling identifies MAPK/ERK pathway as a gatekeeper of nephron progenitor metabolism

Nephron endowment is defined by fetal kidney growth and critically dictates renal health in adults. Despite the advances in understanding the molecular regulation of nephron progenitors, the causes for low congenital nephron count and contribution of basic metabolism to nephron progenitor biology remain poorly understood. Here we characterized the metabolic consequences of MAPK/ERK-deficiency in nephron progenitors, whose maintenance and propagation in developing kidney critically depends on ERK activation. Our LC/MS-based metabolomics profiling identified 42 reduced metabolites, of which 26 were further supported by in vivo transcriptional characterization of MAPK/ERK-deficient nephron progenitors. This revealed a severe shortage of energy and nucleotide biosynthesis precursors, blockage in glycolysis and diminished pyruvate and proline metabolism. Utilization of in vitro kidney cultures demonstrated a dosage-specific function for glycolytic pyruvate as an energy source that controls the shape of the ureteric bud tip kwon to serve as a niche for nephron progenitor regulation. Analysis of the proline biosynthesis effects in developing kidney in vivo revealed premature loss of nephron progenitor maintenance in the absence of Pycr1/2 functions. Our results suggest that MAPK/ERK-dependent nephron progenitor metabolism functionally contributes to progenitor preservation by controlling pyruvate availability and proline metabolism in developing kidneys.

developmental biology↗

Tumor-free elongation of mammalian nephrogenesis by excess fetal GDNF

Due to poor regenerative capacity of adult kidneys, nephron endowment defined by the nephrogenic program during the fetal period dictates renal and related cardiovascular health throughout life. We show that the neurotropic factor GDNF, which is in clinical trials for Parkinsons disease, is capable of prolonging the nephrogenic program beyond its normal cessation without increasing the risk of kidney tumors. Our data demonstrates that excess GDNF expands the nephrogenic program by maintaining nephron progenitors and nephrogenesis in postnatal mouse kidneys. GDNF, through its transcriptional targets excreted from the adjacent epithelium, has a major effect on nephron progenitor self-renewal and maintenance; abnormally high GDNF inhibits nephron progenitor proliferation, but lowering its level normalizes the nephrogenic program to that permissive for nephron progenitor self-renewal and differentiation. Based on our results, we propose that the lifespan of nephron progenitors is determined by mechanisms related to perception of GDNF and other signaling levels.

developmental biology↗