During tissue repair, myofibroblasts produce extracellular matrix (ECM) molecules for tissue resilience and strength. Altered ECM deposition can lead to tissue dysfunction and disease. Identification ...of distinct myofibroblast subsets is necessary to develop treatments for these disorders. We analyzed profibrotic cells during mouse skin wound healing, fibrosis, and aging and identified distinct subpopulations of myofibroblasts, including adipocyte precursors (APs). Multiple mouse models and transplantation assays demonstrate that proliferation of APs but not other myofibroblasts is activated by CD301b-expressing macrophages through insulin-like growth factor 1 and platelet-derived growth factor C. With age, wound bed APs and differential gene expression between myofibroblast subsets are reduced. Our findings identify multiple fibrotic cell populations and suggest that the environment dictates functional myofibroblast heterogeneity, which is driven by fibroblast-immune interactions after wounding.
Mature adipocytes store fatty acids and are a common component of tissue stroma. Adipocyte function in regulating bone marrow, skin, muscle, and mammary gland biology is emerging, but the role of ...adipocyte-derived lipids in tissue homeostasis and repair is poorly understood. Here, we identify an essential role for adipocyte lipolysis in regulating inflammation and repair after injury in skin. Genetic mouse studies revealed that dermal adipocytes are necessary to initiate inflammation after injury and promote subsequent repair. We find through histological, ultrastructural, lipidomic, and genetic experiments in mice that adipocytes adjacent to skin injury initiate lipid release necessary for macrophage inflammation. Tamoxifen-inducible genetic lineage tracing of mature adipocytes and single-cell RNA sequencing revealed that dermal adipocytes alter their fate and generate ECM-producing myofibroblasts within wounds. Thus, adipocytes regulate multiple aspects of repair and may be therapeutic for inflammatory diseases and defective wound healing associated with aging and diabetes.
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•Inhibiting dermal adipocyte lipolysis reduces inflammatory wound bed macrophages•Wound edge adipocytes dedifferentiate within hours after injury•Adipocyte lipolysis is needed for dedifferentiated adipocytes to populate wound beds•Dedifferentiated adipocytes generate wound bed myofibroblasts after injury
Using genetic mouse models and transcriptomic profiling, Shook et al. show that skin resident adipocytes undergo lipolysis to promote efficient macrophage inflammation after injury. Lipolysis also allows adipocyte-derived cells to dedifferentiate and generate diverse extracellular matrix-producing myofibroblasts in the wound bed.
Many eukaryotic proteins are regulated by modification with the ubiquitin‐like protein small ubiquitin‐like modifier (SUMO). This linkage is reversed by SUMO proteases, of which there are two in ...Saccharomyces cerevisiae, Ulp1 and Ulp2. SUMO‐protein conjugation regulates transcription, but the roles of SUMO proteases in transcription remain unclear. We report that Ulp2 is recruited to transcriptionally active genes to control local polysumoylation. Mutant ulp2 cells show impaired association of RNA polymerase II (RNAPII) with, and diminished expression of, constitutively active genes and the inducible CUP1 gene. Ulp2 loss sensitizes cells to 6‐azauracil, a hallmark of transcriptional elongation defects. We also describe a novel chromatin regulatory mechanism whereby histone‐H2B ubiquitylation stimulates histone sumoylation, which in turn appears to inhibit nucleosome association of the Ctk1 kinase. Ctk1 phosphorylates serine‐2 (S2) in the RNAPII C‐terminal domain (CTD) and promotes transcript elongation. Removal of both ubiquitin and SUMO from histones is needed to overcome the impediment to S2 phosphorylation. These results suggest sequential ubiquitin‐histone and SUMO‐histone modifications recruit Ulp2, which removes polySUMO chains and promotes RNAPII transcription elongation.
Synopsis
SUMO‐protein modifications are known to modulate transcription, but the dynamics of these modifications and the roles of SUMO proteases remain unclear. This work reveals that the yeast Ulp2 SUMO protease promotes transcription by coordinating histone sumoylation and serine‐2 phosphorylation of the RNA polymerase II (RNAPII) CTD.
Ulp2 is preferentially recruited to highly transcribed genes and ribosomal protein genes to control local (poly)sumoylation.
Loss of ULP2 leads to impaired association of RNAPII with, and diminished expression of, both constitutive genes and the inducible CUP1 gene.
Histone H2B ubiquitylation promotes histone sumoylation, which in turn appears to inhibit nucleosome binding of the CTD serine‐2 kinase, Ctk1.
Removal of ubiquitin and SUMO from histones by Ubp8 and by Ulp2, respectively, is required to facilitate Ctk1‐nucleosome association and subsequent RNAPII elongation.
RNA polymerase II CTD phosphorylation requires Ubp8‐ and Ulp2‐dependent removal of ubiquitin and SUMO from histones to allow Ctk1 kinase association with nucleosomes.
Genetic diseases can be diagnosed early during pregnancy, but many monogenic disorders continue to cause considerable neonatal and pediatric morbidity and mortality. Early intervention through ...intrauterine gene editing, however, could correct the genetic defect, potentially allowing for normal organ development, functional disease improvement, or cure. Here we demonstrate safe intravenous and intra-amniotic administration of polymeric nanoparticles to fetal mouse tissues at selected gestational ages with no effect on survival or postnatal growth. In utero introduction of nanoparticles containing peptide nucleic acids (PNAs) and donor DNAs corrects a disease-causing mutation in the β-globin gene in a mouse model of human β-thalassemia, yielding sustained postnatal elevation of blood hemoglobin levels into the normal range, reduced reticulocyte counts, reversal of splenomegaly, and improved survival, with no detected off-target mutations in partially homologous loci. This work may provide the basis for a safe and versatile method of fetal gene editing for human monogenic disorders.
The blood disorder, β-thalassaemia, is considered an attractive target for gene correction. Site-specific triplex formation has been shown to induce DNA repair and thereby catalyse genome editing. ...Here we report that triplex-forming peptide nucleic acids (PNAs) substituted at the γ position plus stimulation of the stem cell factor (SCF)/c-Kit pathway yielded high levels of gene editing in haematopoietic stem cells (HSCs) in a mouse model of human β-thalassaemia. Injection of thalassemic mice with SCF plus nanoparticles containing γPNAs and donor DNAs ameliorated the disease phenotype, with sustained elevation of blood haemoglobin levels into the normal range, reduced reticulocytosis, reversal of splenomegaly and up to 7% β-globin gene correction in HSCs, with extremely low off-target effects. The combination of nanoparticle delivery, next generation γPNAs and SCF treatment may offer a minimally invasive treatment for genetic disorders of the blood that can be achieved safely and simply by intravenous administration.
Decidua is a transient uterine tissue shared by mammals with hemochorial placenta and is essential for pregnancy. The decidua is infiltrated by many immune cells promoting pregnancy. Adult bone ...marrow (BM)-derived cells (BMDCs) differentiate into rare populations of nonhematopoietic endometrial cells in the uterus. However, whether adult BMDCs become nonhematopoietic decidual cells and contribute functionally to pregnancy is unknown. Here, we show that pregnancy mobilizes mesenchymal stem cells (MSCs) to the circulation and that pregnancy induces considerable adult BMDCs recruitment to decidua, where some differentiate into nonhematopoietic prolactin-expressing decidual cells. To explore the functional importance of nonhematopoietic BMDCs to pregnancy, we used Homeobox a11 (Hoxa11)-deficient mice, having endometrial stromal-specific defects precluding decidualization and successful pregnancy. Hoxa11 expression in BM is restricted to nonhematopoietic cells. BM transplant (BMT) from wild-type (WT) to Hoxa11-/- mice results in stromal expansion, gland formation, and marked decidualization otherwise absent in Hoxa11-/- mice. Moreover, in Hoxa11+/- mice, which have increased pregnancy losses, BMT from WT donors leads to normalized uterine expression of numerous decidualization-related genes and rescue of pregnancy loss. Collectively, these findings reveal that adult BMDCs have a previously unrecognized nonhematopoietic physiologic contribution to decidual stroma, thereby playing important roles in decidualization and pregnancy.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Fungi in the class
are ecologically diverse, including mycorrhizas, endophytes of roots and leaves, plant pathogens, aquatic and aero-aquatic hyphomycetes, mammalian pathogens, and saprobes. These ...fungi are commonly detected in cultures from diseased tissue and from environmental DNA extracts. The identification of specimens from such character-poor samples increasingly relies on DNA sequencing. However, the current classification of
is still largely based on morphologically defined taxa, especially at higher taxonomic levels. Consequently, the formal
classification is frequently poorly congruent with the relationships suggested by DNA sequencing studies. Previous class-wide phylogenies of
have been based on ribosomal DNA markers, with most of the published multi-gene studies being focussed on particular genera or families. In this paper we collate data available from specimens representing both sexual and asexual morphs from across the genetic breadth of the class, with a focus on generic type species, to present a phylogeny based on up to 15 concatenated genes across 279 specimens. Included in the dataset are genes that were extracted from 72 of the genomes available for the class, including 10 new genomes released with this study. To test the statistical support for the deepest branches in the phylogeny, an additional phylogeny based on 3156 genes from 51 selected genomes is also presented. To fill some of the taxonomic gaps in the 15-gene phylogeny, we further present an ITS gene tree, particularly targeting ex-type specimens of generic type species. A small number of novel taxa are proposed:
ord. nov., and
and
fams. nov. The formal taxonomic changes are limited in part because of the ad hoc nature of taxon and specimen selection, based purely on the availability of data. The phylogeny constitutes a framework for enabling future taxonomically targeted studies using deliberate specimen selection. Such studies will ideally include designation of epitypes for the type species of those genera for which DNA is not able to be extracted from the original type specimen, and consideration of morphological characters whenever genetically defined clades are recognized as formal taxa within a classification.
In eukaryotic cells, organelle-specific stress-response mechanisms are vital for maintaining cellular homeostasis. The Golgi apparatus, an essential organelle of the secretory system, is the major ...site of protein modification and sorting within a cell and functions as a platform for spatially regulated signaling. Golgi homeostasis mechanisms that regulate organelle structure and ensure precise processing and localization of protein substrates remain poorly understood. Using a chemical biology strategy to induce protein unfolding, we uncover a Golgi-specific transcriptional response. An RNA-sequencing profile of this stress response compared with the current state-of-the-art Golgi stressors, nigericin and xyloside, demonstrates the enhanced precision of Golgi targeting achieved with our system. The data set further reveals previously uncharacterized genes that we find to be essential for Golgi structural integrity. These findings highlight the Golgi's ability to sense misfolded proteins and establish new aspects of Golgi autoregulation.
Functional deficits persist after spinal cord injury (SCI) because axons in the adult mammalian central nervous system (CNS) fail to regenerate. However, modest levels of spontaneous functional ...recovery are typically observed after trauma and are thought to be mediated by the plasticity of intact circuitry. The mechanisms underlying intact circuit plasticity are not delineated. Here, we characterize the in vivo transcriptome of sprouting intact neurons from Ngr1 null mice after partial SCI. We identify the lysophosphatidic acid signaling modulators LPPR1 and LPAR1 as intrinsic axon growth modulators for intact corticospinal motor neurons after adjacent injury. Furthermore, in vivo LPAR1 inhibition or LPPR1 overexpression enhances sprouting of intact corticospinal tract axons and yields greater functional recovery after unilateral brainstem lesion in wild-type mice. Thus, the transcriptional profile of injury-induced sprouting of intact neurons reveals targets for therapeutic enhancement of axon growth initiation and new synapse formation.
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•Mechanisms driving functional plasticity of intact CNS circuits are unknown•Retrograde spinal tracing reveals CST neurons undergoing functional plasticity•Transcriptional profiling of these neurons reveals pro-axon growth targets•Molecular modulation of the identified LPA-LPPR1 axis enhances plasticity post-SCI
Fink et al. present an original in vivo screen identifying targets that drive spontaneous functional plasticity in intact corticospinal motor neurons after CNS injury. They show that exploitation of one of the targets identified (LPAR1-LPPR1 axis) results in significant anatomical and functional recovery after adult SCI.
Lineage selective transcription factors (TFs) are important regulators of tumorigenesis, but their biological functions are often context dependent with undefined epigenetic mechanisms of action. In ...this study, we uncover a conditional role for the endodermal and pulmonary specifying TF GATA6 in lung adenocarcinoma (LUAD) progression. Impairing Gata6 in genetically engineered mouse models reduces the proliferation and increases the differentiation of Kras mutant LUAD tumors. These effects are influenced by the epithelial cell type that is targeted for transformation and genetic context of Kras-mediated tumor initiation. In LUAD cells derived from surfactant protein C expressing progenitors, we identify multiple genomic loci that are bound by GATA6. Moreover, suppression of Gata6 in these cells significantly alters chromatin accessibility, particularly at distal enhancer elements. Analogous to its paradoxical activity in lung development, GATA6 expression fluctuates during different stages of LUAD progression and can epigenetically control diverse transcriptional programs associated with bone morphogenetic protein signaling, alveolar specification, and tumor suppression. These findings reveal how GATA6 can modulate the chromatin landscape of lung cancer cells to control their proliferation and divergent lineage dependencies during tumor progression.
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