Pub Date : 2024-09-09DOI: 10.1101/2024.09.08.611891
Siamak Redhai, Nick Hirschmueller, Tianyu Wang, Shivohum Bahuguna, Svenja Leible, Stefan Peidli, Erica Valentini, Sviatoslav Kharuk, Michaela Holzem, Lea Braeckow, Fillip Port, David Ibberson, Wolfgang Huber, Michael Boutros
The molecular programs that drive proliferation and differentiation of intestinal stem cells (ISCs) are essential for organismal fitness. Notch signalling regulates the binary fate decision of ISCs, favouring enterocyte commitment when Notch activity is high and enteroendocrine cell (EE) fate when activity is low. However, the gene regulatory mechanisms that underlie this process on an organ scale remain poorly understood. Here, we find that the expression of the C2H2-type zinc-finger transcription factor Chronophage (Cph), homologous to mammalian BCL11, increases specifically along the ISC-to-EE lineage when Notch is inactivated. We show that the expression of Cph is regulated by the Achaete-Scute Complex (AS-C) gene, scute, which directly binds to multiple sites within the Cph locus to promote its expression. Our genetic and single-cell RNA sequencing experiments demonstrate that Cph maintains the ISC and EE populations and is necessary to remodel the transcriptome of progenitor cells with low Notch activity. By identifying and functionally validating Cph target genes, we uncover a novel role for sugar free frosting (sff) in directing proliferative and lineage commitment steps of ISCs. Our results shed light on the mechanisms by which Cph sustains intestinal epithelial homeostasis and could represent a conserved strategy for balancing proliferation and differentiation in different tissues and species.
{"title":"Proliferation and differentiation of intestinal stem cells depends on the zinc finger transcription factor BCL11/Chronophage","authors":"Siamak Redhai, Nick Hirschmueller, Tianyu Wang, Shivohum Bahuguna, Svenja Leible, Stefan Peidli, Erica Valentini, Sviatoslav Kharuk, Michaela Holzem, Lea Braeckow, Fillip Port, David Ibberson, Wolfgang Huber, Michael Boutros","doi":"10.1101/2024.09.08.611891","DOIUrl":"https://doi.org/10.1101/2024.09.08.611891","url":null,"abstract":"The molecular programs that drive proliferation and differentiation of intestinal stem cells (ISCs) are essential for organismal fitness. Notch signalling regulates the binary fate decision of ISCs, favouring enterocyte commitment when Notch activity is high and enteroendocrine cell (EE) fate when activity is low. However, the gene regulatory mechanisms that underlie this process on an organ scale remain poorly understood. Here, we find that the expression of the C2H2-type zinc-finger transcription factor Chronophage (Cph), homologous to mammalian BCL11, increases specifically along the ISC-to-EE lineage when Notch is inactivated. We show that the expression of Cph is regulated by the Achaete-Scute Complex (AS-C) gene, scute, which directly binds to multiple sites within the Cph locus to promote its expression. Our genetic and single-cell RNA sequencing experiments demonstrate that Cph maintains the ISC and EE populations and is necessary to remodel the transcriptome of progenitor cells with low Notch activity. By identifying and functionally validating Cph target genes, we uncover a novel role for sugar free frosting (sff) in directing proliferative and lineage commitment steps of ISCs. Our results shed light on the mechanisms by which Cph sustains intestinal epithelial homeostasis and could represent a conserved strategy for balancing proliferation and differentiation in different tissues and species.","PeriodicalId":501269,"journal":{"name":"bioRxiv - Developmental Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142211596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cell fate determination during early embryonic development is a complex process modulated by gene expression. The intricate interplay of transcriptional and post-transcriptional regulation is integral to the developmental trajectory of embryogenesis, yet how RNA processing may contribute to early development programming is largely elusive. Leveraging recent technological advances in single-molecule nanopore sequencing, we developed a single-cell long-read transcriptome sequencing technology, allowing a clear view of transcript diversity during zebrafish embryogenesis, particularly spanning the periods of pre- and post-zygotic genome activation (ZGA). A closer examination of the dynamic transcript usage and potential alternative splicing revealed that abundant stage-specific transcripts with differential coding potentials are involved in distinct biological functions. Specifically, we identified two cell populations at the onset of ZGA based on isoform diversity instead of gene profiling, which followed divergent developmental trajectories toward the ectoderm and the presumptive ectoderm. These two populations of cells were characterized by divergent splicing regulations linked to differential RNA-binding proteins, including SNRPA and SFPQ. Altogether, using the single-cell long-read transcriptome sequencing strategy, our work has revealed the cell-specific transcriptome dynamics contributing to the cell fate determination during embryogenesis.
{"title":"Deciphering the Cell-Specific Transcript Heterogeneity and Alternative Splicing during the Early Embryonic Development of Zebrafish","authors":"Xiumei Lin, Xue Wang, Chang Liu, Chuanyu Liu, Tao Zeng, Ziqi Yuan, Meidi Hu, Rong Xiang, Kaichen Zhao, Jie Zhou, Shichen Yang, Yang Wang, Kaifeng Meng, Hui Wang, Guangli He, Rui Zhao, Jiaheng Liu, Yunqi Huang, Jingfang Pan, Jialu Wang, Junyi Chen, Fei Guo, Yuliang Dong, Xun Xu, Daji Luo, Ying Gu, Longqi Liu, Zhiqiang Dong, Liang Chen","doi":"10.1101/2024.09.08.611790","DOIUrl":"https://doi.org/10.1101/2024.09.08.611790","url":null,"abstract":"Cell fate determination during early embryonic development is a complex process modulated by gene expression. The intricate interplay of transcriptional and post-transcriptional regulation is integral to the developmental trajectory of embryogenesis, yet how RNA processing may contribute to early development programming is largely elusive. Leveraging recent technological advances in single-molecule nanopore sequencing, we developed a single-cell long-read transcriptome sequencing technology, allowing a clear view of transcript diversity during zebrafish embryogenesis, particularly spanning the periods of pre- and post-zygotic genome activation (ZGA). A closer examination of the dynamic transcript usage and potential alternative splicing revealed that abundant stage-specific transcripts with differential coding potentials are involved in distinct biological functions. Specifically, we identified two cell populations at the onset of ZGA based on isoform diversity instead of gene profiling, which followed divergent developmental trajectories toward the ectoderm and the presumptive ectoderm. These two populations of cells were characterized by divergent splicing regulations linked to differential RNA-binding proteins, including SNRPA and SFPQ. Altogether, using the single-cell long-read transcriptome sequencing strategy, our work has revealed the cell-specific transcriptome dynamics contributing to the cell fate determination during embryogenesis.","PeriodicalId":501269,"journal":{"name":"bioRxiv - Developmental Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142211603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Previous experiments inducing leakage of embryonic cerebrospinal fluid (CSF) suggest the necessity of intraventricular CSF pressure (PCSF) for brain morphogenesis. Nevertheless, how embryonic PCSF occurs is unclear, especially in utero. Using a Landis water manometer, we measured PCSF in fetal mice isolated from the amniotic cavity (PCSF-ISO). At embryonic day (E) 13, PCSF-ISO was 82.7 Pa. Intraventricular injections of ≥2 μl of saline elevated PCSF-ISO by ~30%. Intraventricularly injecting inhibitors of CSF secretion decreased PCSF-ISO by ~30%. Shh-mediated cerebral-wall expansion and the resulting ventricular narrowing did not significantly increase PCSF-ISO. Removal of the brain-surrounding contractile tissues decreased PCSF-ISO by 80-90%. The intraamniotic pressure measured in utero (PAF-IU) was 1030.7 Pa. Our direct measurement revealed that the PCSF in utero (PCSF-IU) was 1076.4 Pa, confirming the susceptibility of PCSF to external factors. Subsequent PCSF measurements under hydrostatic pressure loading suggested that PCSF-IU = PCSF-ISO + PAF-IU, a relationship further used to estimate PCSF-IU at other ages when direct measurement was not possible. The estimated PCSF-IU decreased almost constantly from E10 to E16 (2000 → 500 Pa).
{"title":"CSF pressure in fetal mice in utero: External factors pressurize the intraventricular space","authors":"Koichiro Tsujikawa, Reina Muramatsu, Takaki Miyata","doi":"10.1101/2024.09.08.611845","DOIUrl":"https://doi.org/10.1101/2024.09.08.611845","url":null,"abstract":"Previous experiments inducing leakage of embryonic cerebrospinal fluid (CSF) suggest the necessity of intraventricular CSF pressure (P<sub>CSF</sub>) for brain morphogenesis. Nevertheless, how embryonic P<sub>CSF</sub> occurs is unclear, especially in utero. Using a Landis water manometer, we measured P<sub>CSF</sub> in fetal mice isolated from the amniotic cavity (P<sub>CSF-ISO</sub>). At embryonic day (E) 13, P<sub>CSF-ISO</sub> was 82.7 Pa. Intraventricular injections of ≥2 μl of saline elevated P<sub>CSF-ISO</sub> by ~30%. Intraventricularly injecting inhibitors of CSF secretion decreased P<sub>CSF-ISO</sub> by ~30%. Shh-mediated cerebral-wall expansion and the resulting ventricular narrowing did not significantly increase P<sub>CSF-ISO</sub>. Removal of the brain-surrounding contractile tissues decreased P<sub>CSF-ISO</sub> by 80-90%. The intraamniotic pressure measured in utero (P<sub>AF-IU</sub>) was 1030.7 Pa. Our direct measurement revealed that the P<sub>CSF</sub> in utero (P<sub>CSF-IU</sub>) was 1076.4 Pa, confirming the susceptibility of P<sub>CSF</sub> to external factors. Subsequent P<sub>CSF</sub> measurements under hydrostatic pressure loading suggested that P<sub>CSF-IU</sub> = P<sub>CSF-ISO</sub> + P<sub>AF-IU</sub>, a relationship further used to estimate P<sub>CSF-IU</sub> at other ages when direct measurement was not possible. The estimated P<sub>CSF-IU</sub> decreased almost constantly from E10 to E16 (2000 → 500 Pa).","PeriodicalId":501269,"journal":{"name":"bioRxiv - Developmental Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142211597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-07DOI: 10.1101/2024.09.06.611740
Carlos A I Alonso, Jenna Haverfield, Gabriela Regalado, Sihem Sellami, Natascha Gagnon, Ajay Rajaram, Pierre O Fiset, Aimee K Ryan, Koren K Mann, Indra R Gupta
Background: Arsenic is a naturally occurring toxicant and industrial byproduct with significant health risks. Globally, millions of people are exposed to arsenic concentrations that exceed the World Health Organization's recommended limit of 10 μg/L. Chronic arsenic exposure is linked to an increased risk of chronic kidney disease (CKD); however, the effects of arsenic exposure on kidney development remain unclear. Eukaryotes methylate inorganic arsenic (iAsIII) using the enzyme arsenic 3 methyltransferase (As3mt), that converts it to methylated intermediates, mono and dimethyl arsonous acid (MMAIII and DMAIII), and mono and dimethyl arsonic acid (MMAV and DMAV). We hypothesized that arsenicals exposure during mouse kidney development impairs nephron formation. Methods: Cultured mouse embryonic kidney explants were treated with inorganic arsenite (iAsIII), MMAIII, MMAV, and DMAV. Female mice harboring a humanized version of AS3MT and wild-type mice with murine As3mt were exposed to iAsIII throughout gestation and weaning and their offspring were analyzed for kidney defects. Results: Inorganic arsenic, iAsIII (200 μ/L), inhibited ureteric bud branching morphogenesis and growth of mouse kidneys at embryonic day 11.5 (E11.5) and E12.5, but not at E13.5. MMAIII, but not MMAV or DMAV, impaired ureteric bud branching and kidney explant growth. Additionally, iAsIII exposure increased apoptosis in the metanephric mesenchyme of E11.5 explants and decreased Gdnf transcription, which may explain the impairment in ureteric bud branching. Humanized mouse pups exposed to 200 μ/L iAsIII in utero, showed a 20% reduction in kidney weight normalized to body weight and a 28% reduction in nephron number, compared to kidneys of wild-type mice. Conclusion: Exposure to arsenicals during embryonic development impairs ureteric bud branching morphogenesis and decreases nephron endowment, which may predispose to CKD in adulthood.
{"title":"Mouse nephron formation is impaired by moderate-dose arsenical exposure","authors":"Carlos A I Alonso, Jenna Haverfield, Gabriela Regalado, Sihem Sellami, Natascha Gagnon, Ajay Rajaram, Pierre O Fiset, Aimee K Ryan, Koren K Mann, Indra R Gupta","doi":"10.1101/2024.09.06.611740","DOIUrl":"https://doi.org/10.1101/2024.09.06.611740","url":null,"abstract":"Background: Arsenic is a naturally occurring toxicant and industrial byproduct with significant health risks. Globally, millions of people are exposed to arsenic concentrations that exceed the World Health Organization's recommended limit of 10 μg/L. Chronic arsenic exposure is linked to an increased risk of chronic kidney disease (CKD); however, the effects of arsenic exposure on kidney development remain unclear. Eukaryotes methylate inorganic arsenic (iAsIII) using the enzyme arsenic 3 methyltransferase (As3mt), that converts it to methylated intermediates, mono and dimethyl arsonous acid (MMAIII and DMAIII), and mono and dimethyl arsonic acid (MMAV and DMAV). We hypothesized that arsenicals exposure during mouse kidney development impairs nephron formation. Methods: Cultured mouse embryonic kidney explants were treated with inorganic arsenite (iAsIII), MMAIII, MMAV, and DMAV. Female mice harboring a humanized version of AS3MT and wild-type mice with murine As3mt were exposed to iAsIII throughout gestation and weaning and their offspring were analyzed for kidney defects. Results: Inorganic arsenic, iAsIII (200 μ/L), inhibited ureteric bud branching morphogenesis and growth of mouse kidneys at embryonic day 11.5 (E11.5) and E12.5, but not at E13.5. MMAIII, but not MMAV or DMAV, impaired ureteric bud branching and kidney explant growth. Additionally, iAsIII exposure increased apoptosis in the metanephric mesenchyme of E11.5 explants and decreased Gdnf transcription, which may explain the impairment in ureteric bud branching. Humanized mouse pups exposed to 200 μ/L iAsIII in utero, showed a 20% reduction in kidney weight normalized to body weight and a 28% reduction in nephron number, compared to kidneys of wild-type mice. Conclusion: Exposure to arsenicals during embryonic development impairs ureteric bud branching morphogenesis and decreases nephron endowment, which may predispose to CKD in adulthood.","PeriodicalId":501269,"journal":{"name":"bioRxiv - Developmental Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142211601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-07DOI: 10.1101/2024.09.03.611053
Kiara C. Eldred, Sierra J Edgerton, Isabel Ortuno-Lizaran, Juliette Wohlschlegel, Stephanie M Sherman, Sidnee Petter, Gracious Wyatt-Draher, Dawn Hoffer, Ian Glass, Anna C La Torre, Thomas A Reh
Non-mammalian vertebrates maintain a proliferative stem cell population at the far periphery of their retina called the ciliary marginal zone (CMZ), which gives rise to all retinal cell types and contributes to retinal regeneration upon injury. Humans do not maintain a proliferative CMZ into adulthood; however, it is not known how long in development this region continues to generate new neurons. Here, we identify a population of cells in the far peripheral retina of the fetal human that continues to proliferate long after the rest of the retina is quiescent. Single cell RNA-sequencing and EdU tracing at late time points in development reveal that this region has features of the non-mammalian CMZ, including the capacity to produce both early and late born cell types at late developmental stages, and a longer cell cycle than more centrally located retinal progenitor cells (RPCs). Moreover, while more central RPCs exit the cell cycle with the addition of a TGFB-inhibitor, we show that early RPCs within the CMZ do not. These findings define the late stages of neurogenesis in human retinal development, and present a unique model system to study the fetal CMZ in humans.
{"title":"Ciliary marginal zone of the developing human retina maintains retinal progenitor cells until late gestational stages","authors":"Kiara C. Eldred, Sierra J Edgerton, Isabel Ortuno-Lizaran, Juliette Wohlschlegel, Stephanie M Sherman, Sidnee Petter, Gracious Wyatt-Draher, Dawn Hoffer, Ian Glass, Anna C La Torre, Thomas A Reh","doi":"10.1101/2024.09.03.611053","DOIUrl":"https://doi.org/10.1101/2024.09.03.611053","url":null,"abstract":"Non-mammalian vertebrates maintain a proliferative stem cell population at the far periphery of their retina called the ciliary marginal zone (CMZ), which gives rise to all retinal cell types and contributes to retinal regeneration upon injury. Humans do not maintain a proliferative CMZ into adulthood; however, it is not known how long in development this region continues to generate new neurons. Here, we identify a population of cells in the far peripheral retina of the fetal human that continues to proliferate long after the rest of the retina is quiescent. Single cell RNA-sequencing and EdU tracing at late time points in development reveal that this region has features of the non-mammalian CMZ, including the capacity to produce both early and late born cell types at late developmental stages, and a longer cell cycle than more centrally located retinal progenitor cells (RPCs). Moreover, while more central RPCs exit the cell cycle with the addition of a TGFB-inhibitor, we show that early RPCs within the CMZ do not. These findings define the late stages of neurogenesis in human retinal development, and present a unique model system to study the fetal CMZ in humans.","PeriodicalId":501269,"journal":{"name":"bioRxiv - Developmental Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142211614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-07DOI: 10.1101/2024.09.05.609312
Julie Uveira, Antoine Donati, Marvin Léria, Marion Lechable, François Lahaye, Christine Vesque, Evelyn Houliston, Tsuyoshi Momose
Body axis specification is a crucial event in animal embryogenesis, and was an essential evolutionary innovation for founding the animal kingdom. It involves two distinct components that coordinate to establish the spatial organisation of the embryo: initiation of cascades of regionalised gene expression and orientation of morphogenetic processes such as body elongation. Intense interest in the first component has revealed Wnt/β-catenin signalling as ancestrally responsible for initiating regional gene expression, but the evolutionary origin of oriented morphogenesis has received little attention. Here, by addressing the cell and morphological basis of body axis development in embryos of the cnidarian Clytia hemisphaerica, we have uncovered a simple and likely ancestral coordination mechanism between Wnt/β-catenin signalling and directed morphogenesis. We show that the ligand Wnt3, known to initiate oral gene expression via localised Wnt/β-catenin pathway activation, also has a key β-catenin-independent role in globally orienting planar cell polarity (PCP) to direct morphogenesis along the oral-aboral axis. This PCP orientation occurs in two distinct steps: local orientation by Wnt3 and global propagation by conserved core PCP protein interactions along the body axis. From these findings we propose novel scenarios for PCP-driven symmetry-breaking underlying the emergence of the animal body plan.
{"title":"Planar cell polarity coordination in a cnidarian embryo provides clues to animal body axis evolution","authors":"Julie Uveira, Antoine Donati, Marvin Léria, Marion Lechable, François Lahaye, Christine Vesque, Evelyn Houliston, Tsuyoshi Momose","doi":"10.1101/2024.09.05.609312","DOIUrl":"https://doi.org/10.1101/2024.09.05.609312","url":null,"abstract":"Body axis specification is a crucial event in animal embryogenesis, and was an essential evolutionary innovation for founding the animal kingdom. It involves two distinct components that coordinate to establish the spatial organisation of the embryo: initiation of cascades of regionalised gene expression and orientation of morphogenetic processes such as body elongation. Intense interest in the first component has revealed Wnt/β-catenin signalling as ancestrally responsible for initiating regional gene expression, but the evolutionary origin of oriented morphogenesis has received little attention. Here, by addressing the cell and morphological basis of body axis development in embryos of the cnidarian Clytia hemisphaerica, we have uncovered a simple and likely ancestral coordination mechanism between Wnt/β-catenin signalling and directed morphogenesis. We show that the ligand Wnt3, known to initiate oral gene expression via localised Wnt/β-catenin pathway activation, also has a key β-catenin-independent role in globally orienting planar cell polarity (PCP) to direct morphogenesis along the oral-aboral axis. This PCP orientation occurs in two distinct steps: local orientation by Wnt3 and global propagation by conserved core PCP protein interactions along the body axis. From these findings we propose novel scenarios for PCP-driven symmetry-breaking underlying the emergence of the animal body plan.","PeriodicalId":501269,"journal":{"name":"bioRxiv - Developmental Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142211600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-07DOI: 10.1101/2024.09.06.611611
Robert Mitchell-Gee, Robert Hoff, Kumar Vishal, Daniel Hancock, Sam McKitrick, Cristina Newnes-Querejeta, TyAnna Lovato, Richard Cripps, Michael Taylor
Vertebrate muscle fibres have a population of Muscle Stem Cells (MuSCs), or satellite cells, vital to muscle growth, homeostasis and repair. In Drosophila, adult MuSCs with similar characteristics have only recently been described. This has opened up the Drosophila system for analysing how MuSCs operate in muscle maintenance, repair and ageing. Here we show that the Him gene is expressed in the adult muscle progenitors (AMPs), or myoblasts, that make the adult Drosophila thoracic flight and jump muscles. Notably, we also show that Him is expressed in the flight muscle MuSCs identifying Him as only the second genetic marker of these insect MuSCs. We then explored Him function. Him mutants have disrupted organisation of the thoracic jump muscle, resulting in reduced jumping ability. Him mutants also have a reduced pool of the myoblasts that will develop into the flight muscles. In the flight muscles themselves, Him mutants have an age-dependent decrease in the number of MuSCs, indicating that Him is required for maintenance of the adult muscle stem cell population. Moreover, this decrease in MuSCs coincides with a functional effect: there is an age- dependent decline in flight ability. Overall, Him is a novel marker of the Drosophila adult MuSC, and is required during ageing both to maintain MuSC number and flight ability.
脊椎动物的肌肉纤维中有一群肌肉干细胞（MuSCs）或卫星细胞，它们对肌肉的生长、平衡和修复至关重要。在果蝇中，具有类似特征的成体肌肉干细胞最近才被描述出来。这为分析 MuSCs 如何在肌肉维护、修复和老化过程中发挥作用开辟了果蝇系统。在这里，我们发现Him基因在成体肌肉祖细胞（AMPs）或肌母细胞中表达，而成体肌肉祖细胞是果蝇胸部飞行肌和跳跃肌的制造者。值得注意的是，我们还发现，Him 在飞行肌肉成肌细胞中也有表达，这表明 Him 是这些昆虫成肌细胞的第二个遗传标记。我们随后探索了 Him 的功能。Him突变体的胸跳肌组织结构被破坏，导致跳跃能力下降。Him突变体中发育成飞行肌的肌母细胞数量也有所减少。在飞行肌肉中，Him突变体的MuSCs数量随年龄而减少，这表明Him是维持成体肌肉干细胞群所必需的。此外，MuSCs的减少与功能效应相吻合：飞行能力的下降与年龄有关。总之，Him是果蝇成体肌肉干细胞的一个新标记，在衰老过程中需要它来维持肌肉干细胞的数量和飞行能力。
{"title":"The Drosophila myogenic inhibitor Him gene is essential for adult muscle function and muscle stem cell maintenance","authors":"Robert Mitchell-Gee, Robert Hoff, Kumar Vishal, Daniel Hancock, Sam McKitrick, Cristina Newnes-Querejeta, TyAnna Lovato, Richard Cripps, Michael Taylor","doi":"10.1101/2024.09.06.611611","DOIUrl":"https://doi.org/10.1101/2024.09.06.611611","url":null,"abstract":"Vertebrate muscle fibres have a population of Muscle Stem Cells (MuSCs), or satellite cells, vital to muscle growth, homeostasis and repair. In Drosophila, adult MuSCs with similar characteristics have only recently been described. This has opened up the Drosophila system for analysing how MuSCs operate in muscle maintenance, repair and ageing. Here we show that the Him gene is expressed in the adult muscle progenitors (AMPs), or myoblasts, that make the adult Drosophila thoracic flight and jump muscles. Notably, we also show that Him is expressed in the flight muscle MuSCs identifying Him as only the second genetic marker of these insect MuSCs. We then explored Him function. Him mutants have disrupted organisation of the thoracic jump muscle, resulting in reduced jumping ability. Him mutants also have a reduced pool of the myoblasts that will develop into the flight muscles. In the flight muscles themselves, Him mutants have an age-dependent decrease in the number of MuSCs, indicating that Him is required for maintenance of the adult muscle stem cell population. Moreover, this decrease in MuSCs coincides with a functional effect: there is an age- dependent decline in flight ability. Overall, Him is a novel marker of the Drosophila adult MuSC, and is required during ageing both to maintain MuSC number and flight ability.","PeriodicalId":501269,"journal":{"name":"bioRxiv - Developmental Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142211599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-07DOI: 10.1101/2024.09.04.611228
Nicha Tokavanich, Byron Chan, Katelyn Strauss, Chris Castro, Yuki Arai, Mizuki Nagata, Marc Foretz, Daniel J Brooks, Noriaki Ono, Wanida Ono, Marc Wein
Alveolar bone supports and anchors teeth. The parathyroid hormone-related protein (PTHrP) pathway plays a key role in alveolar bone biology. Salt inducible kinases (SIKs) are important downstream regulators of PTH/PTHrP signaling in the appendicular skeleton, where SIK inhibition increases bone formation and trabecular bone mass. However, the function of these kinases in alveolar bone remains unknown. Here, we report a critical role for SIK2/SIK3 in alveolar bone development, homeostasis, and socket healing after tooth extraction. Inducible SIK2/SIK3 deletion led to dramatic alveolar bone defects without changes in tooth eruption. Ablating these kinases impairs alveolar bone formation due to disrupted osteoblast maturation, a finding associated with ectopic periostin expression by fibrous cells in regions of absent alveolar bone at steady state and following molar extraction. Distinct phenotypic consequences of SIK2/SIK3 deletion in appendicular versus craniofacial bones prompted us to identify a specific transcriptomic signature in alveolar versus long bone osteoblasts. Thus, SIK2/SIK3 deletion illuminates a key role for these kinases in alveolar bone biology and highlights the emerging concept that different osteoblast subsets utilize unique genetic programs.
牙槽骨支撑并固定着牙齿。甲状旁腺激素相关蛋白（PTHrP）通路在牙槽骨生物学中起着关键作用。盐诱导激酶（SIKs）是附属骨骼中 PTH/PTHrP 信号传导的重要下游调节因子，抑制 SIK 可增加骨形成和骨小梁质量。然而，这些激酶在牙槽骨中的功能仍然未知。在这里，我们报告了 SIK2/SIK3 在拔牙后牙槽骨发育、平衡和牙槽愈合中的关键作用。诱导性 SIK2/SIK3 基因缺失会导致牙槽骨严重缺损，而牙齿萌出却不会发生变化。消减这些激酶会破坏成骨细胞的成熟，从而影响牙槽骨的形成，这一发现与稳定状态下和拔牙后牙槽骨缺失区域的纤维细胞异位表达骨膜增生蛋白有关。SIK2/SIK3缺失在阑尾骨与颅面骨中的表型后果不同，这促使我们在牙槽骨与长骨成骨细胞中发现了特定的转录组特征。因此，SIK2/SIK3缺失阐明了这些激酶在牙槽骨生物学中的关键作用，并强调了不同成骨细胞亚群利用独特遗传程序的新兴概念。
{"title":"Control of alveolar bone development, homeostasis, and socket healing by salt inducible kinases","authors":"Nicha Tokavanich, Byron Chan, Katelyn Strauss, Chris Castro, Yuki Arai, Mizuki Nagata, Marc Foretz, Daniel J Brooks, Noriaki Ono, Wanida Ono, Marc Wein","doi":"10.1101/2024.09.04.611228","DOIUrl":"https://doi.org/10.1101/2024.09.04.611228","url":null,"abstract":"Alveolar bone supports and anchors teeth. The parathyroid hormone-related protein (PTHrP) pathway plays a key role in alveolar bone biology. Salt inducible kinases (SIKs) are important downstream regulators of PTH/PTHrP signaling in the appendicular skeleton, where SIK inhibition increases bone formation and trabecular bone mass. However, the function of these kinases in alveolar bone remains unknown. Here, we report a critical role for SIK2/SIK3 in alveolar bone development, homeostasis, and socket healing after tooth extraction. Inducible SIK2/SIK3 deletion led to dramatic alveolar bone defects without changes in tooth eruption. Ablating these kinases impairs alveolar bone formation due to disrupted osteoblast maturation, a finding associated with ectopic periostin expression by fibrous cells in regions of absent alveolar bone at steady state and following molar extraction. Distinct phenotypic consequences of SIK2/SIK3 deletion in appendicular versus craniofacial bones prompted us to identify a specific transcriptomic signature in alveolar versus long bone osteoblasts. Thus, SIK2/SIK3 deletion illuminates a key role for these kinases in alveolar bone biology and highlights the emerging concept that different osteoblast subsets utilize unique genetic programs.","PeriodicalId":501269,"journal":{"name":"bioRxiv - Developmental Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142211607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-07DOI: 10.1101/2024.09.04.611291
Helen Frances Schmidt, Chelsea B Darwin, Meera V Sundaram
The surface of epithelial tissues is covered by an apical extracellular matrix (aECM). The aECMs of different tissues have distinct compositions to serve distinct functions, yet how a particular cell type assembles the proper aECM is not well understood. We used the cell-type specific matrix of the C. elegans vulva to investigate the connection between cell identity and matrix assembly. The vulva is an epithelial tube composed of seven cell types descending from EGFR/Ras-dependent (1°) and Notch-dependent (2°) lineages. Vulva aECM contains multiple Zona Pellucida domain (ZP) proteins, which are a common component of aECMs across life. ZP proteins LET-653 and CUTL-18 assemble on 1° cell surfaces, while NOAH-1 assembles on a subset of 2° surfaces. All three ZP genes are broadly transcribed, indicating that cell-type specific ZP assembly must be determined by features of the destination cell surface. The paired box (Pax) transcription factor EGL-38 promotes assembly of 1°-matrix and prevents inappropriate assembly of 2° matrix, suggesting that EGL-38 promotes expression of one or more ZP matrix organizers. Our results connect the known signaling pathways and various downstream effectors to EGL-38/Pax expression and the ZP matrix component of vulva cell fate execution. We propose that dedicated transcriptional networks may contribute to cell-appropriate assembly of aECM in many epithelial organs.
{"title":"The Pax transcription factor EGL-38 links EGFR signaling to assembly of a cell-type specific apical extracellular matrix in the Caenorhabditis elegans vulva","authors":"Helen Frances Schmidt, Chelsea B Darwin, Meera V Sundaram","doi":"10.1101/2024.09.04.611291","DOIUrl":"https://doi.org/10.1101/2024.09.04.611291","url":null,"abstract":"The surface of epithelial tissues is covered by an apical extracellular matrix (aECM). The aECMs of different tissues have distinct compositions to serve distinct functions, yet how a particular cell type assembles the proper aECM is not well understood. We used the cell-type specific matrix of the <em>C. elegans</em> vulva to investigate the connection between cell identity and matrix assembly. The vulva is an epithelial tube composed of seven cell types descending from EGFR/Ras-dependent (1°) and Notch-dependent (2°) lineages. Vulva aECM contains multiple Zona Pellucida domain (ZP) proteins, which are a common component of aECMs across life. ZP proteins LET-653 and CUTL-18 assemble on 1° cell surfaces, while NOAH-1 assembles on a subset of 2° surfaces. All three ZP genes are broadly transcribed, indicating that cell-type specific ZP assembly must be determined by features of the destination cell surface. The paired box (Pax) transcription factor EGL-38 promotes assembly of 1°-matrix and prevents inappropriate assembly of 2° matrix, suggesting that EGL-38 promotes expression of one or more ZP matrix organizers. Our results connect the known signaling pathways and various downstream effectors to EGL-38/Pax expression and the ZP matrix component of vulva cell fate execution. We propose that dedicated transcriptional networks may contribute to cell-appropriate assembly of aECM in many epithelial organs.","PeriodicalId":501269,"journal":{"name":"bioRxiv - Developmental Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142211604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-07DOI: 10.1101/2024.09.06.611670
Andras Nagy, Li Guo, Pascal Duchesneau, Evan Sawula, Eric D Jong, Chengjin Li, Tom Waddell
Here, we present a combination of cell and gene therapy that harnesses the regenerative properties of GDF11 in age-related pulmonary fibrosis. Our genome-edited FailSafeTM-GDF11 mouse ESC line provides controlled proliferation and efficient derivation to lung progenitors while inducibly expressing GDF11. When these cells were transplanted into bleomycin-injured aged mice, they acted as a source of reparative cells, restoring the damaged alveolar epithelium. Furthermore, the transplanted cells acted as an in situ factory, enabling the production of GDF11 in response to the inducer drug. This approach attenuated age-associated senescence and led to the successful resolution of fibrosis. Our study presents a promising method for treating pulmonary fibrosis. Additionally, this approach offers a versatile tool that can be expanded to incorporate other regenerative and anti-aging factors. This helps overcome limitations such as high production costs and a short half-life of therapeutic factors. One of the strengths of our system is its ability to allow precise regulation of factor-expression when needed to address specific aging phenotypes.
{"title":"GDF11 secreting cell transplant efficiently ameliorates age-related pulmonary fibrosis","authors":"Andras Nagy, Li Guo, Pascal Duchesneau, Evan Sawula, Eric D Jong, Chengjin Li, Tom Waddell","doi":"10.1101/2024.09.06.611670","DOIUrl":"https://doi.org/10.1101/2024.09.06.611670","url":null,"abstract":"Here, we present a combination of cell and gene therapy that harnesses the regenerative properties of GDF11 in age-related pulmonary fibrosis. Our genome-edited FailSafeTM-GDF11 mouse ESC line provides controlled proliferation and efficient derivation to lung progenitors while inducibly expressing GDF11. When these cells were transplanted into bleomycin-injured aged mice, they acted as a source of reparative cells, restoring the damaged alveolar epithelium. Furthermore, the transplanted cells acted as an in situ factory, enabling the production of GDF11 in response to the inducer drug. This approach attenuated age-associated senescence and led to the successful resolution of fibrosis. Our study presents a promising method for treating pulmonary fibrosis. Additionally, this approach offers a versatile tool that can be expanded to incorporate other regenerative and anti-aging factors. This helps overcome limitations such as high production costs and a short half-life of therapeutic factors. One of the strengths of our system is its ability to allow precise regulation of factor-expression when needed to address specific aging phenotypes.","PeriodicalId":501269,"journal":{"name":"bioRxiv - Developmental Biology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142211606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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