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1.
Acta Gastroenterol Belg ; 84(1): 33-41, 2021.
Article in English | MEDLINE | ID: mdl-33639691

ABSTRACT

Objective: To describe comorbidities and concomitant medications in patients initiating treatment for hepatitis C virus (HCV) infection with direct-acting antiviral (DAA) regimens in Belgium. Methods: This was a noninterventional, observational, multicenter study of data from patient charts. Adult patients with HCV infection receiving second-generation DAA therapy were included. Comorbidities were assessed at the time of HCV treatment initiation. Concomitant medications were recorded at the time of diagnosis and at treatment initiation. Potential clinically relevant drug-drug interactions (DDIs) were assessed based on information available at www.hep-druginteractions.org. The primary objective was to describe concomitant medication use ; secondary objectives were to describe modifications in concomitant therapies and comorbidities. Results: 405 patients were included. A total of 956 comorbidities were reported by 362 patients (median, 2 ; range, 0-15). The most common comorbidities were hypertension (27.2%) ; HIV coinfection (22.5%), and type 2 diabetes mellitus (14.3%). Overall, 1455 concomitant medications were being taken by 365 patients (90.1% ; median, 3 ; range 0-16). The most common concomitant medications were psycholeptics (28.6%), antiviral agents (24.2%), and medications for acid-related disorders (21.0%) Overall, 74/365 (20.3%) patients receiving a concomitant medication required an adaptation to their concomitant medication. The medications that most frequently required change were drugs for acid-related disorders (n = 14) and antiviral drugs (n = 5) ; those that were most frequently stopped were lipid-modifying drugs (n = 25) and drugs for acid-related disorders (n = 13). Conclusion: Physicians are aware of the potential for DDIs with DAAs, but improved alignment between clinical practice and theoretical recommendations is required.


Subject(s)
Coinfection , Diabetes Mellitus, Type 2 , HIV Infections , Hepatitis C, Chronic , Hepatitis C , Adult , Antiviral Agents/adverse effects , Belgium/epidemiology , Diabetes Mellitus, Type 2/drug therapy , Hepacivirus , Hepatitis C/drug therapy , Hepatitis C, Chronic/drug therapy , Hepatitis C, Chronic/epidemiology , Humans
2.
Connect Tissue Res ; 60(6): 597-610, 2019 11.
Article in English | MEDLINE | ID: mdl-31020864

ABSTRACT

Purpose: There is a clinical need to better characterize tissue sources being used for stem cell therapies. This study focuses on comparison of cells and connective tissue progenitors (CTPs) derived from native human infrapatellar fatpad (IPFP), synovium (SYN), and periosteum (PERI). Materials and Methods: IPFP, SYN, PERI were harvested from twenty-eight patients undergoing arthroplasty. CTPs were quantitatively characterized using automated colony-forming-unit assay to compare total nucleated cell concentration-[Cell], cells/mg; prevalence-(PCTP), CTPs/million nucleated cells; CTP concentration-[CTP], CTPs/mg; proliferation and differentiation potential; and correlate outcomes with patient's age and gender. Results: [Cell] did not differ between IPFP, SYN, and PERI. PCTP was influenced by age and gender: patients >60 years, IPFP and SYN had higher PCTP than PERI (p < 0.001) and females had higher PCTP in IPFP (p < 0.001) and SYN (p = 0.001) than PERI. [CTP] was influenced by age: patients <50 years, SYN (p = 0.0165) and PERI (p < 0.001) had higher [CTP] than IPFP; patients between 60 and 69 years, SYN (p < 0.001) had higher [CTP] than PERI; patients >70 years, IPFP (p = 0.006) had higher [CTP] than PERI. In patients >60 years, proliferation potential of CTPs differed significantly (SYN>IPFP>PERI); however, differentiation potentials were comparable between all three tissue sources. Conclusion: SYN and IPFP may serve as a preferred tissue source for patients >60 years, and PERI along with SYN and IPFP may serve as a preferred tissue source for patients <60 years for cartilage repair. However, the heterogeneity among the CTPs in any given tissue source suggests performance-based selection might be useful to optimize cell-sourcing strategies to improve efficacy of cellular therapies for cartilage repair.


Subject(s)
Adipose Tissue/metabolism , Chondrogenesis , Patella/metabolism , Periosteum/metabolism , Stem Cells/metabolism , Synovial Membrane/metabolism , Adipose Tissue/pathology , Adult , Aged , Aged, 80 and over , Cartilage/injuries , Cartilage/metabolism , Cartilage/pathology , Cell- and Tissue-Based Therapy , Female , Humans , Male , Middle Aged , Patella/pathology , Periosteum/pathology , Stem Cells/pathology , Synovial Membrane/pathology
3.
Nature ; 551(7679): 187-191, 2017 11 09.
Article in English | MEDLINE | ID: mdl-29088701

ABSTRACT

Forest edges influence more than half of the world's forests and contribute to worldwide declines in biodiversity and ecosystem functions. However, predicting these declines is challenging in heterogeneous fragmented landscapes. Here we assembled a global dataset on species responses to fragmentation and developed a statistical approach for quantifying edge impacts in heterogeneous landscapes to quantify edge-determined changes in abundance of 1,673 vertebrate species. We show that the abundances of 85% of species are affected, either positively or negatively, by forest edges. Species that live in the centre of the forest (forest core), that were more likely to be listed as threatened by the International Union for Conservation of Nature (IUCN), reached peak abundances only at sites farther than 200-400 m from sharp high-contrast forest edges. Smaller-bodied amphibians, larger reptiles and medium-sized non-volant mammals experienced a larger reduction in suitable habitat than other forest-core species. Our results highlight the pervasive ability of forest edges to restructure ecological communities on a global scale.


Subject(s)
Biodiversity , Forests , Amphibians/anatomy & histology , Animals , Birds/anatomy & histology , Body Size , Geographic Mapping , Mammals/anatomy & histology , Population Dynamics , Reptiles/anatomy & histology
5.
Diagn Interv Imaging ; 94(12): 1337-44, 2013 Dec.
Article in English | MEDLINE | ID: mdl-23849751

ABSTRACT

The analysis of myocardial perfusion is a key step in the cardiac MRI examination. In routine work, this exploration carried out at rest is based on the qualitative first pass study of gadolinium with an ECG-triggered saturation recovery bFFE sequence. In view of recent knowledge, the analysis of the myocardial perfusion under vasodilator stress may be carried out by scintigraphy or MRI, the latter benefiting from the absence of exposure to ionizing rays and a lower cost. Besides coronary disease, the perfusion sequence provides a rich semiology to compare with the clinics and the data from other sequences. Arterial Spin Labeling (ASL) is an alternative technique used in the animal to quantify myocardial perfusion.


Subject(s)
Magnetic Resonance Imaging , Myocardial Perfusion Imaging/statistics & numerical data , Cardiomyopathies/diagnosis , Humans , Myocardial Perfusion Imaging/methods
7.
Plant Cell Rep ; 31(2): 391-401, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22016085

ABSTRACT

Pepper is known to be a recalcitrant species to genetic transformation via Agrobacterium tumefaciens. A. rhizogenes-mediated transformation offers an alternative and rapid possibility to study gene functions in roots. In our study, we developed a new and efficient system for A. rhizogenes transformation of the cultivated species Capsicum annuum. Hypocotyls and foliar organs (true leaves and cotyledons) of Yolo Wonder (YW) and Criollo de Morelos 334 (CM334) pepper cultivars were inoculated with the two constructs pBIN-gus and pHKN29-gfp of A. rhizogenes strain A4RS. Foliar explants of both pepper genotypes infected by A4RS-pBIN-gus or A4RS-pHKN29-gfp produced transformed roots. Optimal results were obtained using the combination of the foliar explants with A4RS-pHKN29-gfp. 20.5% of YW foliar explants and 14.6% of CM334 foliar explants inoculated with A4RS-pHKN29-gfp produced at least one root expressing uniform green fluorescent protein. We confirmed by polymerase chain reaction the presence of the rolB and gfp genes in the co-transformed roots ensuring that they integrated both the T-DNA from the Ri plasmid and the reporter gene. We also demonstrated that co-transformed roots of YW and CM334 displayed the same resistance response to Phytophthora capsici than the corresponding untransformed roots. Our novel procedure to produce C. annuum hairy roots will thus support the functional analysis of potential resistance genes involved in pepper P. capsici interaction.


Subject(s)
Agrobacterium/physiology , Capsicum/microbiology , Genes, Plant/genetics , Genetic Techniques , Plant Leaves/microbiology , Plant Roots/microbiology , Transformation, Genetic , Capsicum/cytology , Capsicum/genetics , Genotype , Hypocotyl/microbiology , Organ Specificity , Plant Leaves/genetics , Plant Roots/cytology , Plant Roots/genetics , Plants, Genetically Modified , Polymerase Chain Reaction , Reproducibility of Results
8.
Theor Appl Genet ; 114(3): 473-86, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17136373

ABSTRACT

The root-knot nematode (Meloidogyne spp.) is a major plant pathogen, affecting several solanaceous crops worldwide. In Capsicum annuum, resistance to this pathogen is controlled by several independent dominant genes--the Me genes. Six Me genes have previously been shown to be stable at high temperature in three highly resistant and genetically distant accessions: PI 322719, PI 201234, and CM334 (Criollo de Morelos 334). Some genes (Me4, Mech1, and Mech2) are specific to certain Meloidogyne species or populations, whereas others (Me1, Me3, and Me7) are effective against a wide range of Meloidogyne species, including M. arenaria, M. javanica, and M. incognita, the most common species in Mediterranean and tropical areas. These genes direct different response patterns in root cells depending on the pepper line and nematode species. Allelism tests and fine mapping using the BSA-AFLP approach showed these genes to be different but linked, with a recombination frequency of 0.02-0.18. Three of the PCR-based markers identified in several genetic backgrounds were common to the six Me genes. Comparative mapping with CarthaGene software indicated that these six genes clustered in a single genomic region within a 28 cM interval. Four markers were used to anchor this cluster on the P9 chromosome on an intraspecific reference map for peppers. Other disease resistance factors have earlier been mapped in the vicinity of this cluster. This genomic area is colinear to chromosome T12 of tomato and chromosome XII of potato. Four other nematode resistance genes have earlier been identified in this area, suggesting that these nematode resistance genes are located in orthologous genomic regions in Solanaceae.


Subject(s)
Capsicum/genetics , Chromosomes, Plant/genetics , Genes, Plant , Plant Diseases/genetics , Plant Diseases/immunology , Plant Roots/parasitology , Tylenchoidea/physiology , Alleles , Animals , Capsicum/parasitology , Chromosome Mapping , Chromosome Segregation , Crosses, Genetic , DNA, Plant/isolation & purification , Genetic Linkage , Genetic Markers , Immunity, Innate/genetics , Solanum lycopersicum/genetics , Polymerase Chain Reaction , Polymorphism, Genetic , Solanum tuberosum/genetics
9.
Hum Reprod ; 19(10): 2227-30, 2004 Oct.
Article in English | MEDLINE | ID: mdl-15298974

ABSTRACT

The meiotic segregation pattern of 83 men carrying a balanced reciprocal translocation between two autosomes has already been published. Nevertheless, the question of intraindividual variations has not been addressed yet. A 32-year-old patient was found to be a carrier of a t(9;22)(q21;q11.2) during the investigations for a couple with infertility for 3 years. Two sperm samples were obtained at more than 3 months interval. Both sperm samples were analyzed in triple FISH with the D9Z1 and LSI BCR/ABL ES translocation probes. The frequency of gametes exhibiting a chromosomal imbalance was 45.32% and 42.1% in samples 1 and 2, respectively, with the unbalanced spermatozoa resulting from adjacent 1, adjacent 2, and 3:1 segregation in decreasing frequencies. No statistically significant difference was found between both segregation profiles. Four studies have analyzed the meiotic segregation pattern of translocations within families; they found similar profiles of meiotic segregation in each family, but not between families. This suggests, along with our results, that meiotic segregation is not a random process. More studies on intraindividual variations are necessary to allow a better understanding of the meiotic behaviour of chromosomal rearrangements and the practical interest of studies of this kind.


Subject(s)
Chromosome Aberrations , Heterozygote , Oligospermia/genetics , Oligospermia/pathology , Translocation, Genetic , Adult , Chromosome Segregation , Chromosomes, Human, Pair 22 , Chromosomes, Human, Pair 9 , Chromosomes, Human, X , Chromosomes, Human, Y , Gene Frequency , Humans , In Situ Hybridization, Fluorescence , Male , Meiosis
10.
Theor Appl Genet ; 109(5): 1058-63, 2004 Sep.
Article in English | MEDLINE | ID: mdl-15173931

ABSTRACT

Fertility restoration of Peterson's cytoplasmic male-sterility in pepper (Capsicum annuum L.) is quantitative and environment-dependent. QTL analysis of fertility restoration was performed based on the test-cross progeny of 77013A (a strict cytoplasmic-genetic male sterile line) and a doubled haploid population of 114 lines obtained from an F1 hybrid between Yolo wonder (a sterility maintainer line) and Perennial (a fertility-restorer line). The fertility of the test-crossed lines was assessed under greenhouse and open field conditions using three criteria related to pollen or seed production. One major QTL for fertility restoration was mapped to chromosome P6. It was significant in all the environments and for all the traits, accounting for 20-69% of the phenotypic variation, depending on the trait. Four additional minor QTLs were also detected on chromosomes P5, P2, and linkage groups PY3 and PY1, accounting for 7-17% of the phenotypic variation. Most of the alleles increasing fertility originated from the restorer parent, except for two alleles at minor QTLs. Phenotypic analysis and genetic dissection indicated that breeding pepper for complete sterility of female lines and high hybrid fertility requires complex combinations of alleles from both parents and a strict control of the environment.


Subject(s)
Capsicum/genetics , Phenotype , Quantitative Trait Loci , Breeding/methods , Capsicum/physiology , Chromosome Mapping , Crosses, Genetic , Fertility/physiology
11.
Theor Appl Genet ; 109(2): 342-51, 2004 Jul.
Article in English | MEDLINE | ID: mdl-15014880

ABSTRACT

'Criollo de Morelos 334' (CM334) is one of the most promising sources of resistance to Phytophthora capsici in pepper. This Mexican accession is distantly related to bell pepper and its resistance displays a complex inheritance. The QTLs involved in resistance to P. capsici were previously mapped. In order to transfer the resistance factors from CM334 into a bell pepper genetic background, a modified, recurrent breeding scheme was initiated. The breeding population was divided into three sub-populations which were screened by distinct phenotypic tests of increasing severity. The plants from the first sub-population were screened with low-severity tests and backcrossed to the susceptible bell pepper; the plants from the second and third sub-populations were screened by more severe resistance tests and crossed with the plants from the first and second sub-populations, respectively. In this study, the phenotypic data for the three sub-populations during five screening/intermating cycles were analysed. In parallel, the changes in allelic frequencies at molecular markers linked to the resistance QTLs were reported. The resistance phenotype and allelic frequencies strongly depended on the sub-population and screening severity. Regarding allelic frequency changes across the selection cycles, a loss of resistant QTL alleles was observed in the first sub-population, particularly for the low-effect QTLs, whereas a better conservation of the resistant QTL alleles was observed in the two other sub-populations. The same trend was observed in the phenotypic data with an increasing resistance level from the first to the third sub-populations. The changes in the allelic frequencies of loci not linked to resistance QTLs and for horticultural traits across the breeding process indicated that the recovery of the recipient parent genome was not significantly affected by the selection for resistance.


Subject(s)
Capsicum/genetics , Immunity, Innate/genetics , Phenotype , Phytophthora , Plant Diseases/microbiology , Analysis of Variance , Capsicum/microbiology , Chromosome Mapping , Crosses, Genetic , Gene Frequency , Genotype , Linear Models , Plant Diseases/genetics , Quantitative Trait Loci/genetics , Selection, Genetic , Species Specificity
12.
Theor Appl Genet ; 107(4): 661-6, 2003 Aug.
Article in English | MEDLINE | ID: mdl-12819909

ABSTRACT

Epidemics of powdery mildew due to Leveillula taurica is an increasing problem in pepper production areas, particularly in coastal regions or greenhouse cultivation. The highly resistant genitor 'H3' was submitted to genetic analysis and QTL mapping in order to promote the introgression of its oligogenic resistance into large and sweet-fruited cultivars. The doubled-haploid progeny from the cross 'H3' (resistant) by 'Vania' (susceptible) was tested for resistance under both natural field infection and artificial inoculation tests, and QTL detection was compared for those two methods. Seven genomic regions including additive QTLs and epistatic interactions were detected, explaining altogether the major part of genotypic variance. Two genomic regions were common to both the evaluation methods, whereas other QTLs were method-specific, reflecting the environment dependence of powdery mildew epidemics. Orthologies with tomato genomic regions carrying resistance genes to L. taurica and Oidium lycopersicum were revealed by comparative mapping with pepper. Tight linkages between the detected QTLs and virus resistance or fruit color traits in pepper were also shown, which adds to the agronomic importance of these regions in pepper breeding programs.


Subject(s)
Ascomycota/pathogenicity , Capsicum/genetics , Capsicum/microbiology , Breeding , Chromosome Mapping , Genes, Plant , Plant Diseases/genetics , Plant Diseases/microbiology , Quantitative Trait Loci
13.
Theor Appl Genet ; 106(8): 1473-85, 2003 May.
Article in English | MEDLINE | ID: mdl-12750791

ABSTRACT

Phytophthora capsici Leonian, known as the causal agent of the stem, collar and root rot, is one of the most serious problems limiting the pepper crop in many areas in the world. Genetic resistance to the parasite displays complex inheritance. Quantitative trait locus (QTL) analysis was performed in three intraspecific pepper populations, each involving an unrelated resistant accession. Resistance was evaluated by artificial inoculations of roots and stems, allowing the measurement of four components involved in different steps of the plant-pathogen interaction. The three genetic maps were aligned using common markers, which enabled the detection of QTLs involved in each resistance component and the comparison of resistance factors existing among the three resistant accessions. The major resistance factor was found to be common to the three populations. Another resistance factor was found conserved between two populations, the others being specific to a single cross. This comparison across intraspecific germplasm revealed a large variability for quantitative resistance loci to P. capsici. It also provided insights both into the allelic relationships between QTLs across pepper germplasm and for the comparative mapping of resistance factors across the Solanaceae.


Subject(s)
Capsicum/genetics , Genes, Plant , Genetic Variation , Phytophthora/pathogenicity , Solanaceae/genetics , Capsicum/microbiology , Phenotype , Quantitative Trait Loci
14.
Theor Appl Genet ; 106(8): 1517-23, 2003 May.
Article in English | MEDLINE | ID: mdl-12750795

ABSTRACT

A "F1" diploid population between Solanum tuberosum 2 x and the wild Solanum spegazzinii was studied. It segregated for resistance against the potato cyst nematode Globodera pallida derived from the wild species. The inheritance had a quantitative nature. Linkage maps of AFLP and RFLP markers were constructed for both parents. Three QTLs were identified on the map of the resistant parent on chromosomes V, VI and XII, respectively. The first one had a major effect and explained more than 50% of the total variance of resistance. It is located in a cluster of resistance genes and may be the same locus as Gpa which has been described formerly. The two others explained about 20% of the total variance each. The QTL on chromosome XII is also in a cluster of resistance genes, and in an orthologous position with resistance genes against nematodes in tomato and pepper.


Subject(s)
Nematoda/pathogenicity , Quantitative Trait Loci , Solanum/genetics , Animals
15.
Diabetologia ; 46(6): 830-8, 2003 Jun.
Article in English | MEDLINE | ID: mdl-12774167

ABSTRACT

AIMS/HYPOTHESIS: Pancreatic ducts are considered as potential sites for neogenesis of beta cells. In vitro studies have reported formation of islets from postnatal human and rodent duct tissue. We examined whether postnatal human duct-cell preparations can generate new beta cells after transplantation. METHODS: Pancreatic duct cells were prepared from the non-endocrine fraction of human donor pancreases that were processed for islet-cell isolation. Grafts containing 0.5 million duct cells with 1% contaminating insulin-positive cells were implanted under the kidney capsule of normoglycaemic nude mice. At 0.5 and 10 weeks post-transplantation, implants were examined for their cellular composition and for the volumes of their composing cell populations, i.e. cytokeratin 19-positive duct cells, synaptophysin-, insulin- and glucagon-positive endocrine cells. RESULTS: Between week 0.5 and 10, duct-cell volume decreased by at least 90% whereas the change in insulin-positive cell volume depended on donor age. Implants from donors over 10 years had a threefold decrease in their insulin-positive cell volume, while those from donors under 10 years had a 2.5-fold increase. After 10 weeks, the implants from the younger donors consisted of 19% insulin-positive cells occurring as single units or small cell clusters. Three percent of these insulin-positive cells also expressed the ductal marker CK 19 and were consistently found in conjunction with ductal epithelia; up to 1% was positive for the proliferation marker BrdU and located in small endocrine cell clusters. CONCLUSIONS/INTERPRETATION: These data indicate that duct cell preparations from donors under 10 years can generate insulin-positive cells. This process might involve differentiation of CK 19-positive-insulin cells that are formed at the duct epithelia as well as proliferation of insulin-positive cells within endocrine cell aggregates.


Subject(s)
Insulin/analysis , Islets of Langerhans Transplantation/pathology , Pancreatic Ducts/cytology , Pancreatic Ducts/transplantation , Adolescent , Adult , Animals , Cells, Cultured , Child , Child, Preschool , Humans , Immunohistochemistry , Infant , Male , Mice , Mice, Nude , Middle Aged , Synaptophysin/analysis , Time Factors , Tissue Donors , Transplantation, Heterologous/pathology
16.
Genome ; 45(5): 839-54, 2002 Oct.
Article in English | MEDLINE | ID: mdl-12416616

ABSTRACT

Three populations composed of a total of 215 doubled haploid lines and 151 F2 individuals were used to design an intraspecific consensus map of pepper (Capsicum annuum L.). The individual maps varied from 685 to 1668 cM with 16 to 20 linkage groups (LGs). The alignment of the three individual maps permitted the arrangement of 12 consensus major linkage groups corresponding to the basic chromosome number of pepper and displaying a complex correspondence with the tomato map. The consensus map contained 100 known-function gene markers and 5 loci of agronomic interest (the disease-resistance loci L, pvr2, and Pvr4; the C locus, which determines capsaicin content; and the up locus, controlling the erect habit of the fruits). The locations of three other disease-resistance loci (Tsw, Me3, and Bs3) and the y locus, which determines the yellow fruit colour, were also found on this consensus map thanks to linked markers. Here we report on the first functional detailed map in pepper. The use of candidate gene sequences as genetic markers allowed us to localize four clusters of disease-resistance gene analogues and to establish syntenic relationships with other species.


Subject(s)
Capsicum/genetics , Genes, Plant , Chromosome Mapping , Chromosomes, Plant/genetics , Crosses, Genetic , DNA, Plant/genetics , Genetic Markers , Haploidy , Solanum lycopersicum/genetics , Multigene Family , Phenotype , Plant Diseases/genetics , Species Specificity
17.
Theor Appl Genet ; 104(4): 586-591, 2002 Mar.
Article in English | MEDLINE | ID: mdl-12582662

ABSTRACT

Partial restriction of cucumber mosaic virus (CMV) long-distance movement originating from the Capsicum annuum inbred line 'Vania' was assessed in a doubled-haploid progeny using two screening methods: the first allowed one to assess the resistance of adult plants decapitated above the fourth leaf and inoculated on the third leaf using a common CMV strain, and the second allowed one to assess CMV resistance to long-distance movement on seedlings inoculated using an atypical CMV strain. For both resistance tests, the behavior of the F(1) hybrid between 'Vania' and the susceptible line 'H3' indicated that partial resistance is inherited as a dominant trait. Phenotypic data from the two screening methods were correlated but the one performed on seedlings was much more severe. A subset of 184 molecular markers well-distributed over the pepper genome was selected for QTL mapping using the composite interval mapping (CIM) method. A total of seven genomic regions, including one major effect and several minor effect QTLs, were shown to be associated with partial restriction of CMV long-distance movement. These results are compared with those already obtained in pepper and also in other solanaceous crops, potato and tomato.

18.
Dev Cell ; 1(2): 277-90, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11702786

ABSTRACT

L-Sox5 and Sox6 are highly identical Sry-related transcription factors coexpressed in cartilage. Whereas Sox5 and Sox6 single null mice are born with mild skeletal abnormalities, Sox5; Sox6 double null fetuses die with a severe, generalized chondrodysplasia. In these double mutants, chondroblasts poorly differentiate. They express the genes for all essential cartilage extracellular matrix components at low or undetectable levels and initiate proliferation after a long delay. All cartilages are thus extracellular matrix deficient and remain rudimentary. While chondroblasts in the center of cartilages ultimately activate prehypertrophic chondrocyte markers, epiphyseal chondroblasts ectopically activate hypertrophic chondrocyte markers. Thick intramembranous bone collars develop, but the formation of cartilage growth plates and endochondral bones is disrupted. L-Sox5 and Sox6 are thus redundant, potent enhancers of chondroblast functions, thereby essential for endochondral skeleton formation.


Subject(s)
Cartilage/embryology , Cartilage/physiology , DNA-Binding Proteins/metabolism , DNA-Binding Proteins/physiology , High Mobility Group Proteins/metabolism , High Mobility Group Proteins/physiology , Nuclear Proteins/metabolism , Nuclear Proteins/physiology , Transcription Factors , Animals , Bone Development , Bone and Bones/abnormalities , Cell Differentiation , Chondrocytes/cytology , Chondrocytes/metabolism , Exostoses, Multiple Hereditary/genetics , In Situ Hybridization , Mice , Microscopy, Fluorescence , Models, Biological , Models, Genetic , Mutation , Phenotype , SOXD Transcription Factors
19.
Curr Opin Cell Biol ; 13(6): 721-7, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11698188

ABSTRACT

Three transcription factors of the Sox family have essential roles in different steps of the chondrocyte differentiation pathway. Because the transcription factor Cbfa1, which is needed for osteoblast differentiation, also stimulates hypertrophic chondrocyte maturation, it links the chondrocyte and osteoblast differentiation pathways in endochondral bone formation. Signaling molecules, including Indian Hedgehog, PTHrP and FGFs, also establish essential links either between these pathways, between steps in these pathways or between signaling molecules and transcription factors, so that a more comprehensive view of endochondral bone formation is emerging.


Subject(s)
Bone and Bones/embryology , Cartilage/embryology , Chondrogenesis , Osteogenesis , Animals , Cell Differentiation , Chondrocytes/physiology , Growth Plate/anatomy & histology , Growth Plate/embryology , Humans , Mesoderm/physiology , Mice , Models, Biological , Signal Transduction , Transcription Factors/physiology
20.
J Bone Miner Res ; 16(10): 1837-45, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11585348

ABSTRACT

Fracture repair is the best-characterized situation in which activation of chondrogenesis takes place in an adult organism. To better understand the mechanisms that regulate chondrogenic differentiation of mesenchymal progenitor cells during fracture repair, we have investigated the participation of transcription factors L-Sox5, Sox6, and Sox9 in this process. Marked up-regulation of L-Sox5 and Sox9 messenger RNA (mRNA) and smaller changes in Sox6 mRNA levels were observed in RNAse protection assays during early stages of callus formation, followed by up-regulation of type II collagen production. During cartilage expansion, the colocalization of L-Sox5, Sox6, and Sox9 by immunohistochemistry and type II collagen transcripts by in situ hybridization confirmed a close relationship of these transcription factors with the chondrocyte phenotype and cartilage production. On chondrocyte hypertrophy, production of L-Sox5, Sox9 and type II collagen were down-regulated markedly and that of type X collagen was up-regulated. Finally, using adenovirus mediated bone morphogenetic protein 2 (BMP-2) gene transfer into fracture site we showed accelerated up-regulation of the genes for all three Sox proteins and type II collagen in fractures treated with BMP-2 when compared with control fractures. These data suggest that L-Sox5, Sox6, and Sox9 are involved in the activation and maintenance of chondrogenesis during fracture healing and that enhancement of chondrogenesis by BMP-2 is mediated via an L-Sox5/Sox6/Sox9-dependent pathway.


Subject(s)
Bone Morphogenetic Proteins/genetics , DNA-Binding Proteins/genetics , High Mobility Group Proteins/genetics , Nuclear Proteins/genetics , Transcription Factors/genetics , Transforming Growth Factor beta , Up-Regulation , Animals , Bone Morphogenetic Protein 2 , Bony Callus/metabolism , Collagen Type II/genetics , Collagen Type II/metabolism , Fracture Healing , Gene Transfer Techniques , Male , Mice , Mice, Inbred C57BL , Mice, Inbred DBA , RNA, Messenger/analysis , SOX9 Transcription Factor , SOXD Transcription Factors
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