Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 194
Filter
1.
Dev Cell ; 58(6): 461-473.e7, 2023 03 27.
Article in English | MEDLINE | ID: mdl-36905926

ABSTRACT

Organ development involves the sustained production of diverse cell types with spatiotemporal precision. In the vertebrate jaw, neural-crest-derived progenitors produce not only skeletal tissues but also later-forming tendons and salivary glands. Here we identify the pluripotency factor Nr5a2 as essential for cell-fate decisions in the jaw. In zebrafish and mice, we observe transient expression of Nr5a2 in a subset of mandibular postmigratory neural-crest-derived cells. In zebrafish nr5a2 mutants, nr5a2-expressing cells that would normally form tendons generate excess jaw cartilage. In mice, neural-crest-specific Nr5a2 loss results in analogous skeletal and tendon defects in the jaw and middle ear, as well as salivary gland loss. Single-cell profiling shows that Nr5a2, distinct from its roles in pluripotency, promotes jaw-specific chromatin accessibility and gene expression that is essential for tendon and gland fates. Thus, repurposing of Nr5a2 promotes connective tissue fates to generate the full repertoire of derivatives required for jaw and middle ear function.


Subject(s)
Receptors, Cytoplasmic and Nuclear , Zebrafish , Mice , Animals , Zebrafish/metabolism , Receptors, Cytoplasmic and Nuclear/metabolism , Cell Differentiation/physiology , Connective Tissue/metabolism , Zebrafish Proteins/genetics , Zebrafish Proteins/metabolism , Neural Crest/metabolism , Gene Expression Regulation, Developmental
2.
Bone ; 167: 116611, 2023 02.
Article in English | MEDLINE | ID: mdl-36395960

ABSTRACT

Zebrafish (Danio rerio) are aquatic vertebrates with significant homology to their terrestrial counterparts. While zebrafish have a centuries-long track record in developmental and regenerative biology, their utility has grown exponentially with the onset of modern genetics. This is exemplified in studies focused on skeletal development and repair. Herein, the numerous contributions of zebrafish to our understanding of the basic science of cartilage, bone, tendon/ligament, and other skeletal tissues are described, with a particular focus on applications to development and regeneration. We summarize the genetic strengths that have made the zebrafish a powerful model to understand skeletal biology. We also highlight the large body of existing tools and techniques available to understand skeletal development and repair in the zebrafish and introduce emerging methods that will aid in novel discoveries in skeletal biology. Finally, we review the unique contributions of zebrafish to our understanding of regeneration and highlight diverse routes of repair in different contexts of injury. We conclude that zebrafish will continue to fill a niche of increasing breadth and depth in the study of basic cellular mechanisms of skeletal biology.


Subject(s)
Tendons , Zebrafish , Animals , Zebrafish/genetics , Bone and Bones , Cartilage
3.
Development ; 149(1)2022 01 01.
Article in English | MEDLINE | ID: mdl-34878091

ABSTRACT

A major feature of Saethre-Chotzen syndrome is coronal craniosynostosis, the fusion of the frontal and parietal bones at the coronal suture. It is caused by heterozygous loss-of-function mutations in either of the bHLH transcription factors TWIST1 and TCF12. Although compound heterozygous Tcf12; Twist1 mice display severe coronal synostosis, the individual role of Tcf12 had remained unexplored. Here, we show that Tcf12 controls several key processes in calvarial development, including the rate of frontal and parietal bone growth, and the boundary between sutural and osteogenic cells. Genetic analysis supports an embryonic requirement for Tcf12 in suture formation, as combined deletion of Tcf12 in embryonic neural crest and mesoderm, but not in postnatal suture mesenchyme, disrupts the coronal suture. We also detected asymmetric distribution of mesenchymal cells on opposing sides of the wild-type frontal and parietal bones, which prefigures later bone overlap at the sutures. In Tcf12 mutants, reduced asymmetry is associated with bones meeting end-on-end, possibly contributing to synostosis. Our results support embryonic requirements of Tcf12 in proper formation of the overlapping coronal suture.


Subject(s)
Basic Helix-Loop-Helix Transcription Factors/metabolism , Craniosynostoses/metabolism , Osteogenesis , Skull/embryology , Animals , Basic Helix-Loop-Helix Transcription Factors/genetics , Craniosynostoses/embryology , Craniosynostoses/genetics , Mesenchymal Stem Cells/metabolism , Mesoderm/metabolism , Mice , Mice, Inbred C57BL , Neural Crest/metabolism , Skull/metabolism
4.
Transpl Immunol ; 69: 101447, 2021 12.
Article in English | MEDLINE | ID: mdl-34400246

ABSTRACT

BACKGROUND/OBJECTIVES: Rejection and infectious enteritis in intestinal transplant (ITx) patients present with virtually identical symptoms. Currently, the gold standard for differentiating between these two conditions is endoscopy, which is invasive and costly. Our primary aim was to identify differences in peripheral blood cytokines during episodes of acute cellular rejection (ACR) and infectious enteritis in patients with intestinal transplants. METHODS: This was a prospective, cross-sectional study involving ITx patients transplanted between 2000 and 2016. We studied 63 blood samples collected from 29 ITx patients during periods of normal (n = 24) and abnormal (n = 17) allograft function. PBMCs from whole blood samples were cultured under unstimulated or stimulated conditions with phytohemagglutinin (PHA). The supernatant from these cultures were collected to measure cytokine and chemokine levels using a 38-plex luminex panel. RESULTS: Our study found that cytokines and chemokines are differentially expressed in normal, ACR, and infectious enteritis samples under unstimulated conditions based on heatmap analysis. Although each cohort displayed distinctive signatures, only MDC (p = 0.037) was found to be significantly different between ACR and infectious enteritis. Upon stimulation of PBMCs, patients with ACR demonstrated increased immune reactivity compared to infectious enteritis; though this did not reach statistical significance. CONCLUSIONS: To our knowledge, this is the first comprehensive study comparing cytokine expression during acute rejection and infectious enteritis in intestinal transplant recipients. Our results suggest that cytokines have the potential to be used as clinical markers for risk stratification and/or diagnosis of ACR and infectious enteritis.


Subject(s)
Cytokines , Graft Rejection , Chemokines , Cross-Sectional Studies , Graft Rejection/diagnosis , Humans , Prospective Studies
5.
Development ; 148(16)2021 08 15.
Article in English | MEDLINE | ID: mdl-34338288

ABSTRACT

Proper function of the vertebrate skeleton requires the development of distinct articulating embryonic cartilages. Irx transcription factors are arranged in co-regulated clusters that are expressed in the developing skeletons of the face and appendages. IrxB cluster genes are required for the separation of toes in mice and formation of the hyoid joint in zebrafish, yet whether Irx genes have broader roles in skeletal development remains unclear. Here, we perform a comprehensive loss-of-function analysis of all 11 Irx genes in zebrafish. We uncover conserved requirements for IrxB genes in formation of the fish and mouse scapula. In the face, we find a requirement for IrxAb genes and irx7 in formation of anterior neural crest precursors of the jaw, and for IrxBa genes in formation of endodermal pouches and gill cartilages. We also observe extensive joint loss and cartilage fusions in animals with combinatorial losses of Irx clusters, with in vivo imaging revealing that at least some of these fusions arise through inappropriate chondrogenesis. Our analysis reveals diverse roles for Irx genes in the formation and later segmentation of the facial skeleton.


Subject(s)
Cartilage/embryology , Chondrogenesis/genetics , Homeodomain Proteins/metabolism , Multigene Family , Mutant Proteins/metabolism , Skull/embryology , Transcription Factors/metabolism , Zebrafish Proteins/metabolism , Zebrafish/embryology , Zebrafish/genetics , Alleles , Animals , Animals, Genetically Modified , Body Patterning/genetics , Gene Expression , Gene Expression Regulation, Developmental , Homeodomain Proteins/genetics , Mutation , Neural Crest/metabolism , Transcription Factors/genetics , Zebrafish Proteins/genetics
6.
Nat Commun ; 12(1): 4797, 2021 08 10.
Article in English | MEDLINE | ID: mdl-34376651

ABSTRACT

Sutures separate the flat bones of the skull and enable coordinated growth of the brain and overlying cranium. The coronal suture is most commonly fused in monogenic craniosynostosis, yet the unique aspects of its development remain incompletely understood. To uncover the cellular diversity within the murine embryonic coronal suture, we generated single-cell transcriptomes and performed extensive expression validation. We find distinct pre-osteoblast signatures between the bone fronts and periosteum, a ligament-like population above the suture that persists into adulthood, and a chondrogenic-like population in the dura mater underlying the suture. Lineage tracing reveals an embryonic Six2+ osteoprogenitor population that contributes to the postnatal suture mesenchyme, with these progenitors being preferentially affected in a Twist1+/-; Tcf12+/- mouse model of Saethre-Chotzen Syndrome. This single-cell atlas provides a resource for understanding the development of the coronal suture and the mechanisms for its loss in craniosynostosis.


Subject(s)
Cranial Sutures/metabolism , Gene Expression Regulation, Developmental , Osteogenesis/genetics , Single-Cell Analysis/methods , Transcriptome/genetics , Acrocephalosyndactylia/embryology , Acrocephalosyndactylia/genetics , Acrocephalosyndactylia/pathology , Animals , Basic Helix-Loop-Helix Transcription Factors/genetics , Basic Helix-Loop-Helix Transcription Factors/metabolism , Cranial Sutures/cytology , Cranial Sutures/embryology , Dura Mater/cytology , Dura Mater/embryology , Dura Mater/metabolism , Mesoderm/cytology , Mesoderm/embryology , Mesoderm/metabolism , Mice, Knockout , Mice, Transgenic , Osteoblasts/cytology , Osteoblasts/metabolism , RNA-Seq/methods , Skull/cytology , Skull/embryology , Skull/metabolism , Twist-Related Protein 1/genetics , Twist-Related Protein 1/metabolism
8.
Ultrasound Obstet Gynecol ; 55(6): 730-739, 2020 06.
Article in English | MEDLINE | ID: mdl-31273862

ABSTRACT

OBJECTIVE: The Management of Myelomeningocele Study (MOMS) trial demonstrated the safety and efficacy of open fetal surgery for spina bifida aperta (SBA). Recently developed alternative techniques may reduce maternal risks without compromising the fetal neuroprotective effects. The aim of this systematic review was to assess the learning curve (LC) of different fetal SBA closure techniques. METHODS: MEDLINE, Web of Science, EMBASE, Scopus and Cochrane databases and the gray literature were searched to identify relevant articles on fetal surgery for SBA, without language restriction, published between January 1980 and October 2018. Identified studies were reviewed systematically and those reporting all consecutive procedures and with postnatal follow-up ≥ 12 months were selected. Studies were included only if they reported outcome variables necessary to measure the LC, as defined by fetal safety and efficacy. Two authors independently retrieved data, assessed the quality of the studies and categorized observations into blocks of 30 patients. For meta-analysis, data were pooled using a random-effects model when heterogeneous. To measure the LC, we used two complementary methods. In the group-splitting method, competency was defined when the procedure provided results comparable to those in the MOMS trial for 12 outcome variables representing the immediate surgical outcome, short-term neonatal neuroprotection and long-term neuroprotection at ≥ 12 months of age. Then, when raw patient data were available, we performed cumulative sum analysis based on a composite binary outcome defining successful surgery. The composite outcome combined four clinically relevant variables for safety (absence of extreme preterm delivery < 30 weeks, absence of fetal death ≤ 7 days after surgery) and efficacy (reversal of hindbrain herniation and absence of any neonatal treatment of dehiscence or cerebrospinal fluid leakage at the closure site). RESULTS: Of 6024 search results, 17 (0.3%) studies were included, all of which had low, moderate or unclear risk of bias. Fetal SBA closure was performed using standard hysterotomy (11 studies), mini-hysterotomy (one study) or fetoscopy by either exteriorized-uterus single-layer closure (one study), percutaneous single-layer closure (three studies) or percutaneous two-layer closure (one study). Only outcomes for standard hysterotomy could be meta-analyzed. Overall, outcomes improved significantly with experience. Competency was reached after 35 consecutive cases for standard hysterotomy and was predicted to be achieved after ≥ 57 cases for mini-hysterotomy and ≥ 56 for percutaneous two-layer fetoscopy. For percutaneous and exteriorized-uterus single-layer fetoscopy, competency was not reached in the 81 and 28 cases available for analysis, respectively, and LC prediction analysis could not be performed. CONCLUSIONS: The number of cases operated is correlated with the outcome of fetal SBA closure, and the number of operated cases required to reach competency ranges from 35 for standard hysterotomy to ≥ 56-57 for minimally invasive modifications. Our observations provide important information for institutions looking to establish a new fetal center, develop a new fetal surgery technique or train their team, and inform referring clinicians, potential patients and third parties. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.


Curvas de aprendizaje del cierre de la espina bífida fetal mediante cirugía abierta y endoscópica: revisión sistemática y metaanálisis OBJETIVO: El ensayo del Estudio sobre la Gestión del Mielomeningocele (MOMS, por sus siglas en inglés) demostró la seguridad y eficacia de la cirugía fetal abierta para la espina bífida aperta (EBA). Las técnicas alternativas recientemente desarrolladas pueden reducir los riesgos de la madre sin comprometer los efectos neuroprotectores del feto. El objetivo de esta revisión sistemática fue evaluar la curva de aprendizaje (CA) de diferentes técnicas de cierre de la EBA fetal. MÉTODOS: Se realizaron búsquedas en las bases de datos de MEDLINE, Web of Science, EMBASE, Scopus y Cochrane, así como en la literatura gris, para identificar artículos relevantes sobre cirugía fetal para la EBA, sin restricción de idioma, publicados entre enero de 1980 y octubre de 2018. Se examinaron sistemáticamente los estudios identificados y se seleccionaron los que informaban de todos los procedimientos consecutivos y con seguimiento postnatal ≥12 meses. Los estudios se incluyeron sólo si informaban sobre las variables de resultado necesarias para medir la CA, definidas por la seguridad y la eficacia para el feto. Dos autores recuperaron los datos de forma independiente, evaluaron la calidad de los estudios y clasificaron las observaciones en bloques de 30 pacientes. Para el metaanálisis, los datos se agruparon mediante un modelo de efectos aleatorios cuando fueron heterogéneos. Para medir la CA, se usaron dos métodos complementarios. En el método de división de grupos, la competencia se definió cuando el procedimiento proporcionó resultados comparables a los del ensayo MOMS para 12 variables de resultados que representaban el resultado quirúrgico inmediato, la neuroprotección neonatal a corto plazo y la neuroprotección a largo plazo a ≥12 meses de edad. Luego, cuando se dispuso de los datos brutos de los pacientes, se realizó un análisis de suma acumulada basado en un resultado binario compuesto que definió el éxito de la cirugía. El resultado compuesto combinó cuatro variables clínicamente relevantes en cuanto a la seguridad (ausencia de parto pretérmino extremo <30 semanas; ausencia de muerte fetal a ≤7 días después de la cirugía) y eficacia (reducción de la hernia del rombencéfalo y ausencia de cualquier tratamiento neonatal de dehiscencia o derrame de líquido cefalorraquídeo en el lugar del cierre). RESULTADOS: De los 6024 resultados de la búsqueda, se incluyeron 17 (0,3%) estudios, todos ellos con un riesgo de sesgo bajo, moderado o incierto. El cierre de la EBA fetal se realizó mediante histerotomía estándar (11 estudios), mini histerotomía (un estudio) o fetoscopia, ya fuera mediante el cierre exteriorizado del útero de una sola capa (un estudio), el cierre percutáneo de una sola capa (tres estudios) o el cierre percutáneo de dos capas (un estudio). Sólo se pudieron metaanalizar los resultados de la histerotomía estándar. En general, los resultados mejoraron significativamente con la experiencia. Se alcanzó la competencia después de 35 casos consecutivos para la histerotomía estándar y se predijo que se alcanzaría después de ≥57 casos para la mini histerotomía y ≥56 para la fetoscopia percutánea de dos capas. En el caso de las fetoscopias percutánea y exteriorizada del útero de una sola capa, no se alcanzó la competencia en los 81 y 28 casos disponibles para el análisis, respectivamente, y no se pudo realizar el análisis de predicción de la CA. CONCLUSIONES: El número de casos operados está correlacionado con el resultado del cierre de la EBA fetal, y el número de casos operados necesarios para alcanzar la competencia estuvo entre 35 para la histerotomía estándar y ≥56-57 para las operaciones con mínima agresividad. Las observaciones realizadas proporcionan información importante para las instituciones que buscan establecer un nuevo centro fetal, desarrollar una nueva técnica de cirugía fetal o entrenar a su equipo, e informar a los médicos que remiten a especialistas a los posibles pacientes y a terceros. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.


Subject(s)
Fetoscopy/education , Fetus/surgery , Hysterotomy/education , Spina Bifida Cystica/surgery , Adult , Female , Humans , Learning Curve , Pregnancy , Spina Bifida Cystica/embryology
9.
Environ Sci Process Impacts ; 21(8): 1280-1300, 2019 Aug 14.
Article in English | MEDLINE | ID: mdl-31328749

ABSTRACT

The House Observations of Microbial and Environmental Chemistry (HOMEChem) study is a collaborative field investigation designed to probe how everyday activities influence the emissions, chemical transformations and removal of trace gases and particles in indoor air. Sequential and layered experiments in a research house included cooking, cleaning, variable occupancy, and window-opening. This paper describes the overall design of HOMEChem and presents preliminary case studies investigating the concentrations of reactive trace gases, aerosol particles, and surface films. Cooking was a large source of VOCs, CO2, NOx, and particles. By number, cooking particles were predominantly in the ultrafine mode. Organic aerosol dominated the submicron mass, and, while variable between meals and throughout the cooking process, was dominated by components of hydrocarbon character and low oxygen content, similar to cooking oil. Air exchange in the house ensured that cooking particles were present for only short periods. During unoccupied background intervals, particle concentrations were lower indoors than outdoors. The cooling coils of the house ventilation system induced cyclic changes in water soluble gases. Even during unoccupied periods, concentrations of many organic trace gases were higher indoors than outdoors, consistent with housing materials being potential sources of these compounds to the outdoor environment. Organic material accumulated on indoor surfaces, and exhibited chemical signatures similar to indoor organic aerosol.


Subject(s)
Air Microbiology/standards , Air Pollutants/analysis , Air Pollution, Indoor/analysis , Environmental Monitoring/methods , Housing/standards , Particulate Matter/analysis , Aerosols , Air Conditioning , Air Filters , Cooking , Gases , Humans , Particle Size
10.
Elife ; 82019 02 20.
Article in English | MEDLINE | ID: mdl-30785394

ABSTRACT

Much of the vertebrate skeleton develops from cartilage templates that are progressively remodeled into bone. Lineage tracing studies in mouse suggest that chondrocytes within these templates persist and become osteoblasts, yet the underlying mechanisms of this process and whether chondrocytes can generate other derivatives remain unclear. We find that zebrafish cartilages undergo extensive remodeling and vascularization during juvenile stages to generate fat-filled bones. Growth plate chondrocytes marked by sox10 and col2a1a contribute to osteoblasts, marrow adipocytes, and mesenchymal cells within adult bones. At the edge of the hypertrophic zone, chondrocytes re-enter the cell cycle and express leptin receptor (lepr), suggesting conversion into progenitors. Further, mutation of matrix metalloproteinase 9 (mmp9) results in delayed growth plate remodeling and fewer marrow adipocytes. Our data support Mmp9-dependent growth plate remodeling and conversion of chondrocytes into osteoblasts and marrow adipocytes as conserved features of bony vertebrates.


Subject(s)
Adipocytes/cytology , Cell Differentiation/genetics , Chondrocytes/cytology , Osteoblasts/cytology , Animals , Bone Marrow Cells/cytology , Cartilage/growth & development , Collagen Type II/genetics , Gene Expression Regulation, Developmental , Growth Plate/growth & development , SOXE Transcription Factors/genetics , Zebrafish/genetics , Zebrafish/growth & development , Zebrafish Proteins/genetics
11.
Elife ; 72018 10 25.
Article in English | MEDLINE | ID: mdl-30375332

ABSTRACT

Cranial sutures separate the skull bones and house stem cells for bone growth and repair. In Saethre-Chotzen syndrome, mutations in TCF12 or TWIST1 ablate a specific suture, the coronal. This suture forms at a neural-crest/mesoderm interface in mammals and a mesoderm/mesoderm interface in zebrafish. Despite this difference, we show that combinatorial loss of TCF12 and TWIST1 homologs in zebrafish also results in specific loss of the coronal suture. Sequential bone staining reveals an initial, directional acceleration of bone production in the mutant skull, with subsequent localized stalling of bone growth prefiguring coronal suture loss. Mouse genetics further reveal requirements for Twist1 and Tcf12 in both the frontal and parietal bones for suture patency, and to maintain putative progenitors in the coronal region. These findings reveal conservation of coronal suture formation despite evolutionary shifts in embryonic origins, and suggest that the coronal suture might be especially susceptible to imbalances in progenitor maintenance and osteoblast differentiation.


Subject(s)
Acrocephalosyndactylia/genetics , Basic Helix-Loop-Helix Transcription Factors/genetics , Craniosynostoses/genetics , Twist-Related Protein 1/genetics , Acrocephalosyndactylia/pathology , Animals , Bone Development , Craniosynostoses/pathology , Disease Models, Animal , Gene Expression Regulation, Developmental , Gene Knockout Techniques , Humans , Mice , Mutation , Neural Crest/growth & development , Neural Crest/pathology , Osteogenesis/genetics , Zebrafish/genetics
12.
Mol Cell ; 69(2): 265-278.e6, 2018 01 18.
Article in English | MEDLINE | ID: mdl-29351846

ABSTRACT

While Slicer activity of Argonaute is central to RNAi, conserved roles of slicing in endogenous regulatory biology are less clear, especially in mammals. Biogenesis of erythroid Dicer-independent mir-451 involves Ago2 catalysis, but mir-451-KO mice do not phenocopy Ago2 catalytic-dead (Ago2-CD) mice, suggesting other needs for slicing. Here, we reveal mir-486 as another dominant erythroid miRNA with atypical biogenesis. While it is Dicer dependent, it requires slicing to eliminate its star strand. Thus, in Ago2-CD conditions, miR-486-5p is functionally inactive due to duplex arrest. Genome-wide analyses reveal miR-486 and miR-451 as the major slicing-dependent miRNAs in the hematopoietic system. Moreover, mir-486-KO mice exhibit erythroid defects, and double knockout of mir-486/451 phenocopies the cell-autonomous effects of Ago2-CD in the hematopoietic system. Finally, we observe that Ago2 is the dominant-expressed Argonaute in maturing erythroblasts, reflecting a specialized environment for processing slicing-dependent miRNAs. Overall, the mammalian hematopoietic system has evolved multiple conserved requirements for Slicer-dependent miRNA biogenesis.


Subject(s)
Argonaute Proteins/metabolism , MicroRNAs/genetics , Animals , Argonaute Proteins/genetics , Argonaute Proteins/physiology , DEAD-box RNA Helicases/metabolism , Erythroblasts/metabolism , Genome-Wide Association Study , Mammals/metabolism , Mice , Mice, Knockout , MicroRNAs/metabolism , RNA Interference , Ribonuclease III/metabolism , Sequence Analysis, RNA , Sequence Homology, Nucleic Acid
13.
Development ; 144(13): 2517-2528, 2017 07 01.
Article in English | MEDLINE | ID: mdl-28576768

ABSTRACT

The tear-producing lacrimal gland is a tubular organ that protects and lubricates the ocular surface. The lacrimal gland possesses many features that make it an excellent model in which to investigate tubulogenesis, but the cell types and lineage relationships that drive lacrimal gland formation are unclear. Using single-cell sequencing and other molecular tools, we reveal novel cell identities and epithelial lineage dynamics that underlie lacrimal gland development. We show that the lacrimal gland from its earliest developmental stages is composed of multiple subpopulations of immune, epithelial and mesenchymal cell lineages. The epithelial lineage exhibits the most substantial cellular changes, transitioning through a series of unique transcriptional states to become terminally differentiated acinar, ductal and myoepithelial cells. Furthermore, lineage tracing in postnatal and adult glands provides the first direct evidence of unipotent KRT5+ epithelial cells in the lacrimal gland. Finally, we show conservation of developmental markers between the developing mouse and human lacrimal gland, supporting the use of mice to understand human development. Together, our data reveal crucial features of lacrimal gland development that have broad implications for understanding epithelial organogenesis.


Subject(s)
Cell Lineage , Epithelial Cells/cytology , Lacrimal Apparatus/cytology , Lacrimal Apparatus/embryology , Acinar Cells/cytology , Acinar Cells/metabolism , Animals , Biomarkers/metabolism , Epithelial Cells/metabolism , Female , Gene Expression Profiling , Gene Expression Regulation, Developmental , Humans , Mice , Phenotype , Sequence Analysis, RNA , Single-Cell Analysis , Stem Cells/cytology , Stem Cells/metabolism
14.
Dev Biol ; 427(1): 12-20, 2017 07 01.
Article in English | MEDLINE | ID: mdl-28511845

ABSTRACT

The tear film protects the terrestrial animal's ocular surface and the lacrimal gland provides important aqueous secretions necessary for its maintenance. Despite the importance of the lacrimal gland in ocular health, molecular aspects of its development remain poorly understood. We have identified a noncoding RNA (miR-205) as an important gene for lacrimal gland development. Mice lacking miR-205 fail to properly develop lacrimal glands, establishing this noncoding RNA as a key regulator of lacrimal gland development. Specifically, more than half of knockout lacrimal glands never initiated, suggesting a critical role of miR-205 at the earliest stages of lacrimal gland development. RNA-seq analysis uncovered several up-regulated miR-205 targets that may interfere with signaling to impair lacrimal gland initiation. Supporting this data, combinatorial epistatic deletion of Fgf10, the driver of lacrimal gland initiation, and miR-205 in mice exacerbates the lacrimal gland phenotype. We develop a molecular rheostat model where miR-205 modulates signaling pathways related to Fgf10 in order to regulate glandular development. These data show that a single microRNA is a key regulator for early lacrimal gland development in mice and highlights the important role of microRNAs during organogenesis.


Subject(s)
Gene Expression Regulation, Developmental , Lacrimal Apparatus/metabolism , MicroRNAs/genetics , Organogenesis/genetics , Animals , Fibroblast Growth Factor 10/genetics , Fibroblast Growth Factor 10/metabolism , Fluorescent Antibody Technique , Gene Expression Profiling/methods , Lacrimal Apparatus/embryology , Lacrimal Apparatus/growth & development , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic , Reverse Transcriptase Polymerase Chain Reaction , Sequence Analysis, RNA/methods , Signal Transduction/genetics
15.
Curr Opin Genet Dev ; 43: 61-66, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28103525

ABSTRACT

The surface ectoderm is the source of ectodermal appendages including hair, teeth, and many glands. The development and function of ectodermal appendages has been researched extensively, but many of the molecular mechanisms that govern the developmental programs of ectodermal appendages remain elusive. While several protein-coding genes are established as key regulators of ectodermal appendage development, the role of noncoding RNAs is an emerging area of investigation. This review highlights recent advances in studies of microRNA-mediated control of ectodermal appendage development using mouse models. We will also discuss future directions and technological advances that will drive the microRNA field forward and expand our understanding of how individual microRNAs control ectodermal appendage development.


Subject(s)
Ectoderm/growth & development , Hair/metabolism , MicroRNAs/genetics , Tooth/metabolism , Animals , Ectoderm/metabolism , Hair/growth & development , Humans , Mice , MicroRNAs/metabolism , Tooth/growth & development
16.
Exp Physiol ; 101(10): 1245-1252, 2016 10 01.
Article in English | MEDLINE | ID: mdl-27377300

ABSTRACT

What is the topic of this review? We review the current literature on the neural reflex termed the 'inflammatory reflex' that inhibits an excessive release of inflammatory mediators in response to an immune challenge. What advances does it highlight? The original model proposed that the inflammatory reflex is a vago-vagal reflex that controls immune function. We posit that, in the endotoxaemic animal model, the vagus nerves do not appear to play a role. The evidence suggests that the efferent motor pathway, termed here the 'splanchnic anti-inflammatory pathway', is purely sympathetic, travelling via the greater splanchnic nerves to regulate the ensuing inflammatory response to immune challenges. Exposure to immune challenges results in the development of inflammation. An insufficient inflammatory response can be life-threatening, whereas an exaggerated response is also detrimental because it causes tissue damage and, in extreme cases, septic shock that can lead to death. Hence, inflammation must be finely regulated. It is generally accepted that the brain inhibits inflammation induced by an immune challenge in two main ways: humorally, by activating the hypothalamic-pituitary-adrenal axis to release glucocorticoids; and neurally, via a mechanism that has been termed the 'inflammatory reflex'. The efferent arm of this reflex (the neural-to-immune link) was thought to be the 'cholinergic anti-inflammatory pathway'. Here, we discuss data that support the hypothesis that the vagus nerves play no role in the control of inflammation in the endotoxaemic animal model. We have shown and posit that it is the greater splanchnic nerves that are activated in response to the immune challenge and that, in turn, drive postganglionic sympathetic neurons to inhibit inflammation.


Subject(s)
Efferent Pathways/physiology , Inflammation/physiopathology , Reflex/physiology , Splanchnic Nerves/physiology , Animals , Humans , Hypothalamo-Hypophyseal System/physiology , Pituitary-Adrenal System/physiology , Vagus Nerve/physiology
17.
J Musculoskelet Neuronal Interact ; 16(2): 105-12, 2016 06 01.
Article in English | MEDLINE | ID: mdl-27282454

ABSTRACT

PURPOSE: The Achilles tendon (AT) must adapt to meet changes in demands. This study explored AT adaptation by comparing properties within the jump and non-jump legs of jumping athletes. Non-jumping control athletes were included to control limb dominance effects. METHODS: AT properties were assessed in the preferred (jump) and non-preferred (lead) jumping legs of male collegiate-level long and/or high jump (jumpers; n=10) and cross-country (controls; n=10) athletes. Cross-sectional area (CSA), elongation, and force during isometric contractions were used to estimate the morphological, mechanical and material properties of the ATs bilaterally. RESULTS: Jumpers exposed their ATs to more force and stress than controls (all p≤0.03). AT force and stress were also greater in the jump leg of both jumpers and controls than in the lead leg (all p<0.05). Jumpers had 17.8% greater AT stiffness and 24.4% greater Young's modulus in their jump leg compared to lead leg (all p<0.05). There were no jump versus lead leg differences in AT stiffness or Young's modulus within controls (all p>0.05). CONCLUSION: ATs chronically exposed to elevated mechanical loading were found to exhibit greater mechanical (stiffness) and material (Young's modulus) properties.


Subject(s)
Achilles Tendon/physiology , Adaptation, Physiological/physiology , Athletes , Sports/physiology , Adolescent , Adult , Elastic Modulus , Humans , Male , Ultrasonography , Young Adult
18.
Am J Transplant ; 16(4): 1086-93, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26928942

ABSTRACT

The findings and recommendations of the North American consensus conference on training in hepatopancreaticobiliary (HPB) surgery held in October 2014 are presented. The conference was hosted by the Society for Surgical Oncology (SSO), the Americas Hepato-Pancreatico-Biliary Association (AHPBA), and the American Society of Transplant Surgeons (ASTS). The current state of training in HPB surgery in North America was defined through three pathways-HPB, surgical oncology, and solid organ transplant fellowships. Consensus regarding programmatic requirements included establishment of minimum case volumes and inclusion of quality metrics. Formative assessment, using milestones as a framework and inclusive of both operative and nonoperative skills, must be present. Specific core HPB cases should be defined and used for evaluation of operative skills. The conference concluded with a focus on the optimal means to perform summative assessment to evaluate the individual fellow completing a fellowship in HPB surgery. Presentations from the hospital perspective and the American Board of Surgery led to consensus that summative assessment was desired by the public and the hospital systems and should occur in a uniform but possibly modular manner for all HPB fellowship pathways. A task force composed of representatives of the SSO, AHPBA, and ASTS are charged with implementation of the consensus statements emanating from this consensus conference.


Subject(s)
Clinical Competence , Consensus Development Conferences as Topic , Digestive System Surgical Procedures/education , Education, Medical, Graduate/methods , Gastroenterology/education , Liver Transplantation/education , Biliary Tract Surgical Procedures/education , Congresses as Topic , Fellowships and Scholarships/statistics & numerical data , Humans , North America , Pancreatectomy
19.
Transplant Proc ; 47(8): 2473-7, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26518954

ABSTRACT

BACKGROUND: Although intestine-inclusive liver transplantation (IILT) is performed regularly, its perioperative management has not been studied extensively. METHODS: Patients who underwent IILT and isolated liver transplantation (LT) at our center from January 2006 to December 2012 were identified. Among >1,000 LT patients, 90 were selected after matching by age, sex, surgery date, and status of preoperative ventilation for comparison with 45 IILT patients. RESULTS: There were no significant differences regarding preoperative variables between the 2 groups except for international normalized ratio. However, IILT patients had significantly higher intraoperative requirement of blood transfusion, incidences of post-reperfusion syndrome, and hyperkalemia compared with LT patients. Postoperatively, IILT patients had significantly longer hospital stay and higher 1-year mortality. Multivariate analysis indicated that IILT was a primary risk factor associated with the studied complications and adverse outcomes. CONCLUSIONS: Our findings suggest that, compared with LT patients, IILT patients were more prone to develop intraoperative complications and adverse outcomes and should be closely monitored and aggressively managed.


Subject(s)
Intestines/transplantation , Intraoperative Care/statistics & numerical data , Intraoperative Complications/epidemiology , Liver Transplantation/methods , Postoperative Complications/epidemiology , Adolescent , Blood Transfusion/statistics & numerical data , Child , Child, Preschool , Female , Humans , Hyperkalemia/epidemiology , Hyperkalemia/etiology , Incidence , International Normalized Ratio , Intraoperative Care/methods , Intraoperative Complications/etiology , Length of Stay/statistics & numerical data , Liver Transplantation/adverse effects , Liver Transplantation/statistics & numerical data , Male , Multivariate Analysis , Pancreas Transplantation , Postoperative Complications/etiology , Postoperative Period , Reperfusion Injury/epidemiology , Reperfusion Injury/etiology , Retrospective Studies , Risk Factors , Treatment Outcome , Young Adult
20.
Transplant Proc ; 47(3): 863-7, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25724255

ABSTRACT

Pregnancy after solid organ transplantation is becoming more common, with the largest recorded numbers in renal and liver transplant recipients. Intestinal transplantation is relatively new compared to other solid organs, and reports of successful pregnancy are far less frequent. All pregnancies reported to date in intestinal transplant recipients have been in women with stable graft function. The case reported here involves the first reported successful term pregnancy in an intestine-pancreas transplant recipient with chronic graft dysfunction and dependence on both transplant immunosuppression and parenteral nutrition (PN) at the time of conception. Pregnancy was unplanned and unexpected in the setting of chronic illness and menstrual irregularities, discovered incidentally on abdominal ultrasound at approximately 18 weeks' gestation. Rapamune was held, tacrolimus continued, and PN adjusted to maintain consistent weight gain. A healthy female infant was delivered vaginally at term. Medical complications during pregnancy included anemia and need for tunneled catheter replacements. Ascites and edema were improved from baseline, with recurrence of large volume ascites shortly after delivery. Successful pregnancy is possible in the setting of transplant immunosuppression, chronic intestinal graft dysfunction, and long-term PN requirement, but close monitoring is required to ensure the health of mother and child.


Subject(s)
Immunocompromised Host , Intestines/transplantation , Pancreas Transplantation/methods , Parenteral Nutrition , Pregnancy Outcome , Pregnancy, High-Risk , Transplant Recipients , Adult , Female , Gastrointestinal Stromal Tumors/surgery , Humans , Immunosuppressive Agents/therapeutic use , Infant , Pregnancy , Primary Graft Dysfunction , Sirolimus/therapeutic use , Tacrolimus/therapeutic use
SELECTION OF CITATIONS
SEARCH DETAIL
...