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1.
Int J Eat Disord ; 54(5): 764-772, 2021 05.
Article in English | MEDLINE | ID: mdl-33496346

ABSTRACT

OBJECTIVE: Weight loss attempts occur as early as childhood. The impacts of weight loss attempts and weight-related stress on the occurrence of obesity during childhood remain unknown. We aimed to: (a) assess the prevalence of self-reported weight loss attempts and weight-related stress in 8-10 year-old children and (b) determine associations with adiposity 2 years later. METHOD: Data were collected from a cohort study of 564 Canadian children aged 8-10 years, having one or both biological parents with obesity (Quebec Adipose and Lifestyle Investigation in Youth cohort). Self-reported weight loss attempts and weight-related stress were assessed at baseline in the child's questionnaire. Adiposity was measured at baseline and 2 years later using body mass index z-scores (zBMI), waist-to-height ratio (WHtR), and percentage of body fat (%BF) obtained from dual-energy x-ray absorptiometry. Linear and logistic regression analyses were used while adjusting for potential confounders. RESULTS: Forty-eight percent of children reported previous weight loss attempts and 20% reported weight-related stress. Self-reported weight loss attempts and weight-related stress were associated with higher zBMI, WHtR, and %BF 2 years later in adjusted models, although estimates were attenuated when including baseline adiposity measures. Self-reported weight loss attempts, but not weight-related stress, increased the risk of becoming overweight among children who were normal weight at baseline. DISCUSSION: Weight loss attempts are prevalent in children with parental obesity. Children reporting weight loss attempts and weight-related stress tend to have higher adiposity 2 years later and are more likely to become overweight.


Subject(s)
Pediatric Obesity , Weight Loss , Adolescent , Body Mass Index , Canada/epidemiology , Child , Cohort Studies , Humans , Obesity/epidemiology , Pediatric Obesity/epidemiology , Self Report
2.
Br J Sports Med ; 54(5): 272-278, 2020 Mar.
Article in English | MEDLINE | ID: mdl-30728127

ABSTRACT

OBJECTIVE: To assess whether aerobic exercise was superior to usual care in alleviating depressive symptoms in patients living with a major non-communicable disease. DATA SOURCES: Data were obtained from online databases (PubMed, PsycINFO and SPORTDiscus) as well as from reference lists. The search and collection of eligible studies was conducted up to 18 October 2018 (PROSPERO registration number CRD42017069089). STUDY SELECTION: We included interventions that compared aerobic exercise with usual care in adults who reported depressive symptoms (ie, not necessarily the clinical diagnosis of depression) and were living with a major non-communicable disease. RESULTS: Twenty-four studies were included in the meta-analysis (4111 patients). Aerobic exercise alleviated depressive symptoms better than did usual care (standardised mean difference (SMD)=0.50; 95% CI 0.25 to 0.76; Grading of Recommendations Assessment, Development and Evaluation: low quality). Aerobic exercise was particularly effective in alleviating depressive symptoms in cardiac patients (SMD=0.67; 95% CI 0.35 to 0.99). CONCLUSION: Aerobic exercise alleviated depressive symptoms in patients living with a major non-communicable disease, particularly in cardiac populations. Whether aerobic exercise treats clinically diagnosed depression was outside the scope of this study.


Subject(s)
Chronic Disease/psychology , Depression/prevention & control , Exercise , Depression/etiology , Exercise Therapy , Humans
3.
Br J Cancer ; 119(5): 580-590, 2018 08.
Article in English | MEDLINE | ID: mdl-30078843

ABSTRACT

BACKGROUND: Distinguishing lung adenocarcinoma (ADC) from squamous cell carcinoma (SCC) has a tremendous therapeutic implication. Sometimes, the commonly used immunohistochemistry (IHC) markers fail to discriminate between them, urging for the identification of new diagnostic biomarkers. METHODS: We performed IHC on tissue microarrays from two cohorts of lung cancer patients to analyse the expression of beta-arrestin-1, beta-arrestin-2 and clinically used diagnostic markers in ADC and SCC samples. Logistic regression models were applied for tumour subtype prediction. Parallel reaction monitoring (PRM)-based mass spectrometry was used to quantify beta-arrestin-1 in plasma from cancer patients and healthy donors. RESULTS: Beta-arrestin-1 expression was significantly higher in ADC versus SCC samples. Beta-arrestin-1 displayed high sensitivity, specificity and negative predictive value. Its usefulness in an IHC panel was also shown. Plasma beta-arrestin-1 levels were considerably higher in lung cancer patients than in healthy donors and were higher in patients who later experienced a progressive disease than in patients showing complete/partial response following EGFR inhibitor therapy. CONCLUSIONS: Our data identify beta-arrestin-1 as a diagnostic marker to differentiate ADC from SCC and indicate its potential as a plasma biomarker for non-invasive diagnosis of lung cancer. Its utility to predict response to EGFR inhibitors is yet to be confirmed.


Subject(s)
Adenocarcinoma of Lung/diagnosis , Biomarkers, Tumor/metabolism , Carcinoma, Squamous Cell/diagnosis , Lung Neoplasms/diagnosis , Up-Regulation , beta-Arrestin 1/metabolism , Adenocarcinoma of Lung/blood , Adenocarcinoma of Lung/metabolism , Biomarkers, Tumor/blood , Carcinoma, Squamous Cell/blood , Carcinoma, Squamous Cell/metabolism , Case-Control Studies , Diagnosis, Differential , Disease Progression , Early Detection of Cancer , Gene Expression Regulation, Neoplastic , Humans , Logistic Models , Lung Neoplasms/blood , Lung Neoplasms/metabolism , Predictive Value of Tests , Tissue Array Analysis , beta-Arrestin 1/blood
4.
Stem Cell Reports ; 8(4): 1018-1031, 2017 04 11.
Article in English | MEDLINE | ID: mdl-28285879

ABSTRACT

During prostate development, basal and luminal cell lineages are generated through symmetric and asymmetric divisions of bipotent basal cells. However, the extent to which spindle orientation controls division symmetry or cell fate, and the upstream factors regulating this process, are still elusive. We report that GATA3 is expressed in both prostate basal progenitor and luminal cells and that loss of GATA3 leads to a mislocalization of PRKCZ, resulting in mitotic spindle randomization during progenitor cell division. Inherently proliferative intermediate progenitor cells accumulate, leading to an expansion of the luminal compartment. These defects ultimately result in a loss of tissue polarity and defective branching morphogenesis. We further show that disrupting the interaction between PRKCZ and PARD6B is sufficient to recapitulate the spindle and cell lineage phenotypes. Collectively, these results identify a critical role for GATA3 in prostate lineage specification, and further highlight the importance of regulating spindle orientation for hierarchical cell lineage organization.


Subject(s)
Epithelial Cells/cytology , GATA3 Transcription Factor/metabolism , Prostate/growth & development , Spindle Apparatus/metabolism , Stem Cells/cytology , Animals , Cell Polarity , Epithelial Cells/metabolism , GATA3 Transcription Factor/analysis , GATA3 Transcription Factor/genetics , Gene Deletion , Male , Mice, Inbred C57BL , Prostate/cytology , Prostate/ultrastructure , Protein Kinase C/analysis , Protein Kinase C/metabolism , Spindle Apparatus/genetics , Spindle Apparatus/ultrastructure , Stem Cells/metabolism
5.
PLoS One ; 11(1): e0145982, 2016.
Article in English | MEDLINE | ID: mdl-26727492

ABSTRACT

Lower maternal plasma volume expansion was found in idiopathic intrauterine growth restriction (IUGR) but the link remains to be elucidated. An animal model of IUGR was developed by giving a low-sodium diet to rats over the last week of gestation. This treatment prevents full expansion of maternal circulating volume and the increase in uterine artery diameter, leading to reduced placental weight compared to normal gestation. We aimed to verify whether this is associated with reduced remodeling of uteroplacental circulation and placental hypoxia. Dams were divided into two groups: IUGR group and normal-fed controls. Blood velocity waveforms in the main uterine artery were obtained by Doppler sonography on days 14, 18 and 21 of pregnancy. On day 22 (term = 23 days), rats were sacrificed and placentas and uterine radial arteries were collected. Diameter and myogenic response of uterine arteries supplying placentas were determined while expression of hypoxia-modulated genes (HIF-1α, VEGFA and VEGFR2), apoptotic enzyme (Caspase -3 and -9) and glycogen cells clusters were measured in control and IUGR term-placentas. In the IUGR group, impaired blood velocity in the main uterine artery along with increased resistance index was observed without alteration in umbilical artery blood velocity. Radial uterine artery diameter was reduced while myogenic response was increased. IUGR placentas displayed increased expression of hypoxia markers without change in the caspases and increased glycogen cells in the junctional zone. The present data suggest that reduced placental and fetal growth in our IUGR model may be mediated, in part, through reduced maternal uteroplacental blood flow and increased placental hypoxia.


Subject(s)
Disease Models, Animal , Fetal Growth Retardation/blood , Placenta/blood supply , Animals , Apoptosis , Biomarkers/blood , Female , Placenta/diagnostic imaging , Placenta/pathology , Pregnancy , Rats , Rats, Sprague-Dawley , Ultrasonography , Umbilical Arteries/physiopathology
6.
PLoS Genet ; 11(3): e1005093, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25786024

ABSTRACT

Neural crest cells (NCC) are a transient migratory cell population that generates diverse cell types such as neurons and glia of the enteric nervous system (ENS). Via an insertional mutation screen for loci affecting NCC development in mice, we identified one line-named TashT-that displays a partially penetrant aganglionic megacolon phenotype in a strong male-biased manner. Interestingly, this phenotype is highly reminiscent of human Hirschsprung's disease, a neurocristopathy with a still unexplained male sex bias. In contrast to the megacolon phenotype, colonic aganglionosis is almost fully penetrant in homozygous TashT animals. The sex bias in megacolon expressivity can be explained by the fact that the male ENS ends, on average, around a "tipping point" of minimal colonic ganglionosis while the female ENS ends, on average, just beyond it. Detailed analysis of embryonic intestines revealed that aganglionosis in homozygous TashT animals is due to slower migration of enteric NCC. The TashT insertional mutation is localized in a gene desert containing multiple highly conserved elements that exhibit repressive activity in reporter assays. RNAseq analyses and 3C assays revealed that the TashT insertion results, at least in part, in NCC-specific relief of repression of the uncharacterized gene Fam162b; an outcome independently confirmed via transient transgenesis. The transcriptional signature of enteric NCC from homozygous TashT embryos is also characterized by the deregulation of genes encoding members of the most important signaling pathways for ENS formation-Gdnf/Ret and Edn3/Ednrb-and, intriguingly, the downregulation of specific subsets of X-linked genes. In conclusion, this study not only allowed the identification of Fam162b coding and regulatory sequences as novel candidate loci for Hirschsprung's disease but also provides important new insights into its male sex bias.


Subject(s)
Disease Models, Animal , Hirschsprung Disease/genetics , Hirschsprung Disease/pathology , Mice , Mutagenesis, Insertional , Animals , Chromosomes, Mammalian , Enteric Nervous System/abnormalities , Hirschsprung Disease/embryology , Male , Nerve Tissue Proteins/genetics , Nerve Tissue Proteins/metabolism , Neural Crest/metabolism , Silencer Elements, Transcriptional , Transcriptome
7.
Psychosomatics ; 54(1): 35-43, 2013.
Article in English | MEDLINE | ID: mdl-23295005

ABSTRACT

AIMS: There is an increasing interest in single-item self-rated indicators of perceived health and control status in people with chronic illnesses such as diabetes. However, self-rated measures can be associated with indicators of psychological status. The aim of this paper is to explore the association of anxiety, depression, and diabetes distress with self-rated diabetes control. METHODS: Telephone interviews were conducted with 1,787 people with type 2 diabetes taking oral hypoglycemic medication. Diabetes control, health behaviors, and outcomes, anxiety, depression, and diabetes distress were assessed by standardized questionnaires. Self-reported diabetes control was modeled using logistic regression. RESULTS: The best fit logistic regression model for self-rated poor diabetes control was a model that incorporated diabetes distress. When adjusted for age, sex, and all other health behaviors and outcomes, poor diabetes control was most associated with diabetes distress, physical inactivity, being overweight, and poor eating habits. CONCLUSIONS: Results from this study indicate that poor self-rated diabetes control shares the strongest associations with diabetes-specific distress along with perceptions of diabetes-specific healthcare behaviors and outcomes.


Subject(s)
Anxiety/psychology , Depression/psychology , Diabetes Mellitus, Type 2/psychology , Self Report , Stress, Psychological/psychology , Aged , Diabetes Mellitus, Type 2/diagnosis , Diabetes Mellitus, Type 2/drug therapy , Female , Health Behavior , Health Status , Humans , Hypoglycemic Agents/therapeutic use , Logistic Models , Male , Middle Aged , Treatment Outcome
8.
J Psychosom Res ; 74(2): 89-99, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23332522

ABSTRACT

OBJECTIVES: Anxiety has been shown to be associated with poor outcomes in people with diabetes. However, there has been little research which has specifically examined whether diabetes mellitus is associated with an increased likelihood of co-morbid anxiety. The aim of this systematic review and meta-analysis was to determine whether people with diabetes are more likely to have anxiety disorders or elevated anxiety symptoms than people who do not have diabetes. METHODS: A systematic review was performed by three independent reviewers who searched for articles that examined the association between anxiety and diabetes in adults 16 or older. Those studies that met eligibility criteria were put forward for meta-analysis using a random-effects model. RESULTS: A total of twelve studies with data for 12,626 people with diabetes were eligible for inclusion in the systematic review and meta-analysis. Significant and positive associations were found for diabetes with both anxiety disorders, 1.20 (1.10-1.31), and elevated anxiety symptoms, 1.48 (1.02-1.93). The pooled OR for all studies that assessed anxiety was 1.25 (1.10-1.39). CONCLUSIONS: Results from this meta-analysis provide support that diabetes is associated with an increased likelihood of having anxiety disorders and elevated anxiety symptoms.


Subject(s)
Anxiety Disorders/epidemiology , Anxiety/epidemiology , Diabetes Mellitus, Type 1/epidemiology , Diabetes Mellitus, Type 2/epidemiology , Comorbidity , Humans , Prevalence
9.
Biochemistry ; 51(48): 9698-705, 2012 Dec 04.
Article in English | MEDLINE | ID: mdl-23121490

ABSTRACT

Cdx and Hox gene families encode homeodomain-containing transcription factors involved in anterior-posterior vertebral patterning. Although Cdx proteins are direct transcriptional regulators of Hox gene expression, both Hox and Cdx proteins are known to interact with other homeodomain transcription factors, leading us to speculate that Cdx and Hox proteins may also interact physically. In testing this, we found that that Cdx1 is indeed capable of associating with a subset of Hox proteins. This interaction is localized to the homeodomain region of both classes of proteins, is reliant on specific arginine residues in helix I of the Hox homeodomain, and is further modulated by N-terminal Hox sequences. More promiscuous interactions were seen with Hox proteins expressed in vivo, suggestive of bridging factors or post-translational modifications. Finally, we demonstrate that this interaction modulates Cdx-Hox transcriptional activity on a Hox-responsive element. This study is the first example of Cdx-Hox protein interactions and suggests that such complexes may modulate Hox and/or Cdx function.


Subject(s)
Homeodomain Proteins/metabolism , Animals , COS Cells , Chlorocebus aethiops , Chromatin Immunoprecipitation , Mice
10.
Diabetes Res Clin Pract ; 95(1): 162-8, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22071432

ABSTRACT

AIMS: Diabetes control is a multifaceted process involving successful adherence to a self-care regimen as indicated by improved health outcomes. The aim of this study was to ascertain the construct validity of self-reported diabetes control in a population-based survey. METHODS: This study assessed 1848 participants with type 2 diabetes who took part in the Montreal Diabetes Health and Wellbeing Study in Quebec, Canada. Participants were administered the diabetes complications index as well as sociodemographic and health questions. RESULTS: Fair/poor diabetes control was associated with being less likely to check blood glucose weekly, being less likely to drink alcohol, being more likely to report being physically inactive, reporting fair/poor eating habits, being obese and having 1 or more diabetes complications. When all variables were included in a regression model the two variables most strongly associated with poor fair/poor diabetes control were reporting fair/poor eating habits (odds ratio 1.36, 95% CI 1.00-1.85) and having 2 or more diabetes complications (odds ratio 1.60, 95% CI 1.06-2.40). CONCLUSIONS: Results from this study indicate that self-rated diabetes control has associations with diabetes-specific self-care behaviours and outcomes, and is a general indicator of self-care and diabetes-related complications in a population-based survey.


Subject(s)
Diabetes Mellitus, Type 2/therapy , Health Behavior , Self Care , Adolescent , Adult , Aged , Aged, 80 and over , Blood Glucose Self-Monitoring , Canada , Diabetes Mellitus, Type 2/psychology , Female , Health Surveys , Humans , Male , Middle Aged , Self Report , Surveys and Questionnaires
11.
PLoS One ; 6(12): e29038, 2011.
Article in English | MEDLINE | ID: mdl-22174950

ABSTRACT

GATA4 is an essential transcription factor required for the development and function of multiple tissues, including a major role in gonadogenesis. Despite its crucial role, the molecular mechanisms that regulate Gata4 expression in vivo remain poorly understood. We recently found that the Gata4 gene is expressed as multiple transcripts with distinct 5' origins. These co-expressed alternative transcripts are generated by different non-coding first exons with transcripts E1a and E1b being the most prominent. Moreover, we previously showed that an Ebox element, located in Gata4 5' flanking sequences upstream of exon 1a, is important for the promoter activity of these sequences in cell lines. To confirm the importance of this element in vivo, we generated and characterized Gata4 Ebox knockout mice. Quantitative PCR analyses realized on gonads, heart and liver at three developmental stages (embryonic, pre-pubertal and adult) revealed that the Ebox mutation leads to a robust and specific decrease (up to 89%) of Gata4 E1a transcript expression in all tissues and stages examined. However, a detailed characterization of the gonads revealed normal morphology and GATA4 protein levels in these mutants. Our qPCR data further indicate that this outcome is most likely due to the presence of Gata4 E1b mRNA, whose expression levels were not decreased by the Ebox mutation. In conclusion, our work clearly confirms the importance of the proximal Ebox element and suggests that adequate GATA4 protein expression is likely protected by a compensation mechanism between Gata4 E1a and E1b transcripts operating at the translational level.


Subject(s)
GATA4 Transcription Factor/genetics , Promoter Regions, Genetic , Animals , Exons/genetics , Female , Fertility , Gene Expression Regulation , Gene Targeting , Introns/genetics , Male , Mice , Mice, Knockout , Mutation/genetics , Nucleotide Motifs/genetics , Ovary/metabolism , Ovary/pathology , Phenotype , RNA, Messenger/genetics , RNA, Messenger/metabolism , Testis/metabolism , Testis/pathology , Transcription, Genetic
12.
Mol Cancer Res ; 7(6): 821-31, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19531566

ABSTRACT

Current therapeutic strategies against Wilms' tumor (WT) reach 80% to 85% success rate. In spite of this, a remaining 15% to 20% of tumors relapse and are associated with increased metastasis and poor prognosis. To identify new regulators of WT progression, we screened for developmental target genes of Pax2, a key regulator of kidney development and a WT signature gene. We show that one of these target genes, calcineurin A-binding protein (CnABP), is coexpressed with Pax2 during kidney development and is overexpressed in >70% of WT samples analyzed. The CnABP gene encodes a novel protein product conserved in higher vertebrates. We show that CnABP promotes cell proliferation and migration in cell culture experiments. Biochemical analyses additionally identified an interaction between CnABP and calcineurin Abeta, the catalytic subunit of the calcium-responsive serine/threonine phosphatase calcineurin. We show that this interaction leads to the inhibition of calcineurin phosphatase activity and prevents nuclear factor of activated T-cell (NFAT) nuclear translocation. Inhibition of NFAT nuclear localization results in decreased NFAT transcriptional response. Together, these data identify a new modulator of calcineurin signaling up-regulated in WTs.


Subject(s)
Calcineurin/metabolism , Cell Movement/physiology , NFATC Transcription Factors/metabolism , Phosphoproteins/metabolism , Wilms Tumor/metabolism , Amino Acid Sequence , Animals , Calcineurin/chemistry , Calcineurin/genetics , Cell Growth Processes/physiology , Cell Line , Dose-Response Relationship, Drug , Gene Expression Regulation, Neoplastic , Humans , Mice , Mice, Inbred C3H , Molecular Sequence Data , PAX2 Transcription Factor/genetics , PAX2 Transcription Factor/metabolism , Phosphoproteins/chemistry , Phosphoproteins/genetics , Sequence Alignment , Signal Transduction , Transcription, Genetic , Wilms Tumor/genetics , Wilms Tumor/pathology
13.
Dev Biol ; 330(1): 114-22, 2009 Jun 01.
Article in English | MEDLINE | ID: mdl-19328777

ABSTRACT

The Cdx transcription factors regulate anterior-posterior (AP) vertebral patterning, at least in part, through direct regulation of Hox gene expression. Analysis of allelic series of Cdx mutant mice suggests functional overlap between these family members. However, the lack of a Cdx2 null mutant makes these analyses incomplete. Moreover, Hox proteins are sometimes redundant, making it difficult to discern whether Cdx members regulate identical Hox target genes in a redundant manner, or whether they regulate separate Hox genes which then converge on events related to vertebral patterning. To more directly assess this question, we developed a "knock in" model whereby Cdx2 was substituted for Cdx1. Consistent with functional redundancy Cdx2 "knock-in" mice exhibited perfect complementation of the Cdx1-null phenotype, as evidenced by the lack of skeletal defects or altered expression of Hox genes typically impacted by Cdx1 loss-of-function. It has been proposed that vertebral AP patterning is reliant on a gradient of the sum total of Cdx proteins, a posit that is consistent with functional redundancy between Cdx family members. To further assess this, we generated a gain-of-function model using BAC transgenesis to alter Cdx1 dosage. Cdx1 BAC transgenic mice overexpressed Cdx1 mRNA and protein, and fully complemented the Cdx1 null allele. However, gain of Cdx1 dosage via this BAC transgene in an otherwise wild type background had no discernible effects on vertebral patterning or Hox gene expression, suggesting that a moderate alteration in the Cdx protein gradient is of no consequence.


Subject(s)
Body Patterning/physiology , Homeodomain Proteins/metabolism , Transcription Factors/metabolism , Animals , CDX2 Transcription Factor , Embryo, Mammalian/metabolism , Homeodomain Proteins/genetics , In Situ Hybridization , Mice , Mice, Knockout , Transcription Factors/genetics
14.
Bull Cancer ; 93(9): 875-82, 2006 Sep.
Article in French | MEDLINE | ID: mdl-16980230

ABSTRACT

The rising incidence of cancers affecting the kidney emphasizes the need to identify the molecular pathways involved in the initiation and progression of kidney tumors in order to counter this phenomenon. For many years, genes belonging to the PAX family have been the focus of intensive studies in the fields of organogenesis and tumorigenesis. PAX2 and PAX8 encode transcription factors essential for embryonic kidney development. Transcriptionnal repression of these factors is, however, required to allow terminal differentiation of renal epithelia. In human, maintenance and reactivation of PAX2/8 expression are frequently observed in cases of Wilm's tumor and renal cell carcinoma. The precise role of PAX2/8 in kidney cancer is still elusive but results from several studies suggest the exertion of common functions during organogenesis and tumorigenesis of the kidney. Moreover, many members of the PAX family are involved in similar cellular processes such as differentiation/proliferation, motility and apoptosis. Thus, by comparing the functions exerted by PAX factors in several types of cancers should be useful to better define the specific contribution of PAX2/8 to kidney tumorigenesis.


Subject(s)
Kidney Neoplasms/genetics , Paired Box Transcription Factors/genetics , Wilms Tumor/genetics , Eye Proteins/genetics , Eye Proteins/physiology , Gene Expression Regulation, Developmental , Homeodomain Proteins/genetics , Homeodomain Proteins/physiology , Humans , Kidney/embryology , Middle Aged , PAX2 Transcription Factor/genetics , PAX2 Transcription Factor/physiology , PAX3 Transcription Factor , PAX5 Transcription Factor/genetics , PAX5 Transcription Factor/physiology , PAX6 Transcription Factor , PAX7 Transcription Factor/genetics , PAX7 Transcription Factor/physiology , PAX8 Transcription Factor , PAX9 Transcription Factor/genetics , PAX9 Transcription Factor/physiology , Paired Box Transcription Factors/physiology , Repressor Proteins/genetics , Repressor Proteins/physiology
15.
J Biol Chem ; 280(14): 13858-62, 2005 Apr 08.
Article in English | MEDLINE | ID: mdl-15677473

ABSTRACT

It is well established that Hox genes are key players in specifying positional identity along the anterior-posterior axis and are targets of diverse transcription factors implicated in axial patterning. Members of the CDX family (CDX1, -2, and -4) are among such effectors of Hox expression as pertains to vertebral patterning in the mouse. Cdx members are themselves targets of signaling molecules that are also implicated in axial patterning, including retinoic acid (RA) and certain members of Wnt and fibroblast growth factor families. In this regard, we have previously shown that, in the mouse, Cdx1 is directly regulated by RA at the late primitive streak stage (embryonic day (E) 7.5) through a RA response element in the proximal Cdx1 promoter. At E8.5, Cdx1 expression remains essentially limited to the posterior embryo. RA, however, is excluded from the caudal embryo at this later stage, but is found in a more anterior domain encompassing the prospective trunk region. These observations suggest the existence of a repressor mechanism that prevents expression of Cdx1 in these anterior domains of retinoid signaling at E8.5. In the present study, we present evidence suggesting that chicken ovalbumin upstream promoter-transcription factor (COUP-TF) members antagonize RA-induced Cdx1 expression by competing with retinoid X receptor-retinoic acid receptor heterodimers for binding to the Cdx1 RA response element. Consistent with this, in situ hybridization analysis revealed that COUP-TFs are highly expressed in the anterior embryo in domains where Cdx1 transcripts are excluded. Together with other data, these findings suggest a model by which COUP-TF expression is induced by RA in the trunk region as a negative feedback mechanism to restrict Cdx1 expression to the caudal embryo.


Subject(s)
Body Patterning/physiology , DNA-Binding Proteins/metabolism , Gene Expression Regulation, Developmental , Homeodomain Proteins/genetics , Homeodomain Proteins/metabolism , Transcription Factors/metabolism , Tretinoin/metabolism , Animals , COUP Transcription Factor I , Cell Line , Chickens , DNA/metabolism , DNA-Binding Proteins/genetics , Embryo, Mammalian/anatomy & histology , Embryo, Mammalian/physiology , Embryo, Nonmammalian , In Situ Hybridization , Mice , Receptors, Retinoic Acid/genetics , Receptors, Retinoic Acid/metabolism , Response Elements , Transcription Factors/genetics
16.
Mol Cell Biol ; 24(11): 5028-38, 2004 Jun.
Article in English | MEDLINE | ID: mdl-15143193

ABSTRACT

The Cdx1 gene product is essential for normal anterior-posterior vertebral patterning. Expression of Cdx1 is regulated by several pathways implicated in anterior-posterior patterning events, including retinoid and Wnt signaling. We have previously shown that retinoic acid plays a key role in early stages of Cdx1 expression at embryonic day 7.5 (E7.5), while both Wnt3a signaling and an autoregulatory loop, dependent on Cdx1 itself, are involved in later stages of expression (E8.5 to E9.5). This autoregulation is reflected by the ability of Cdx1 to affect expression from proximal Cdx1 promoter sequences in tissue culture. However, this region is devoid of a demonstrable Cdx response element(s). We have now found that Cdx1 and LEF1, a nuclear effector of Wnt signaling, synergize to induce expression from the Cdx1 promoter through previously documented LEF/T-cell factor response elements. We also found a direct physical interaction between the homeodomain of Cdx1 and the B box of LEF1, suggesting a basis for this synergy. Consistent with these observations, analysis of Cdx1 Wnt3a(vt) compound mutants demonstrated that Wnt and Cdx1 converged on Cdx1 expression and vertebral patterning in vivo. Further data suggest that Cdx-high-mobility group box interactions might be involved in a number of additional pathways.


Subject(s)
DNA-Binding Proteins/metabolism , Homeodomain Proteins/metabolism , RNA, Messenger/metabolism , Transcription Factors/metabolism , Transcription, Genetic/physiology , Animals , Gene Expression Regulation/physiology , HMGB Proteins , In Vitro Techniques , Lymphoid Enhancer-Binding Factor 1 , Mice , Nuclear Proteins/metabolism , Promoter Regions, Genetic , Protein Structure, Tertiary , SOXB1 Transcription Factors
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