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1.
Clin Exp Allergy ; 48(7): 862-874, 2018 07.
Article in English | MEDLINE | ID: mdl-29665158

ABSTRACT

BACKGROUND: Oral immunotherapy to peanut is effective in desensitizing patients but has significant side effects including anaphylaxis and gastrointestinal symptoms. In most protocols, peanut is administered in a vehicle food. OBJECTIVE: In an exclusively adolescent population, we tested a new approach using sealed capsules of peanut (gastrointestinal delivery oral immunotherapy or GIDOIT) to bypass the upper gastrointestinal tract. The primary aim was to assess the efficacy of the oral build-up phase of GIDOIT and the secondary aim to analyse its safety. METHODS: Adolescents with a history of a clinical allergic reaction after peanut ingestion were included in a 2-armed, parallel-design, individually randomized, double-blind, placebo-controlled, multicentre trial after a positive double-blind placebo-controlled oral food challenge (DBPCFC1). A central randomization centre used computer-generated tables to allocate treatments. Peanut (or placebo) capsules were ingested daily over a period of 24 weeks with increments every 2 weeks from 2 to 400 mg of peanut protein (pp). Primary outcome was tolerance of 400 mg of pp at DBPCFC2. RESULTS: Thirty patients were included between September 2013 and May 2014. At DBPCFC2, unresponsiveness to 400 mg of pp was achieved in 17/21 peanut group patients (2 withdrawn patients) and 1/9 in the placebo group (Intention-to-treat analysis, P < .001, absolute difference = 0.7, 95%IC 0.43 0.96). Oropharyngeal symptoms were equally frequent in both groups. No dysphagia or other signs of eosinophilic oesophagitis occurred. Digestive adverse events (AE) were more frequent in the treated group (P = .02), but mild and without compliance issues. Only one severe advent event led to withdrawal in a patient who ingested twice the investigated treatment. Peanut-specific humoral immune responses were modulated. CONCLUSION: The GIDOIT protocol demonstrated clinical and immunological efficacy and had an acceptable level of safety with weak oropharyngeal symptoms, no dysphagia, mild digestive events and few severe systemic AE.


Subject(s)
Allergens/immunology , Antigens, Plant/immunology , Arachis/adverse effects , Desensitization, Immunologic , Gastrointestinal Tract/immunology , Peanut Hypersensitivity/immunology , Peanut Hypersensitivity/therapy , Administration, Oral , Adolescent , Age Factors , Allergens/administration & dosage , Biomarkers , Child , Desensitization, Immunologic/methods , Female , Humans , Immunoglobulin E/immunology , Immunoglobulin G/immunology , Male , Peanut Hypersensitivity/diagnosis , Prevalence , Treatment Outcome
2.
Vet Pathol ; 47(1): 167-76, 2010 Jan.
Article in English | MEDLINE | ID: mdl-20080498

ABSTRACT

Animal models carrying mutations in the hairless (Hr) gene provide a rich resource for study of hair follicle biology. A spontaneous mouse mutant with a phenotype strikingly similar to rhino mutants of Hr arose spontaneously in the mouse facility at Oak Ridge National Laboratory. Sequence analysis of Hr in these mutants uncovered a nonsense mutation in exon 12, designated as Hr(rh-R) (rhino, Oak Ridge). The mutation led to significant reduction in Hr mRNA levels, predicted to be due to nonsense-mediated decay. Histological analysis indicated dilated hair follicle infundibula at 14 days of age that rapidly became filled with cornified material. Microarray analyses revealed that expression levels of many genes involved in keratinocyte differentiation, epidermal regeneration, and wound healing were significantly upregulated before morphological detection of the phenotype, suggesting their role in onset of the Hr(rh-R) phenotype. Identification of this new Hr allele and the underlying molecular alterations allows further understanding of the role of Hr in hair follicle biology.


Subject(s)
Codon, Nonsense/genetics , Mice, Hairless/genetics , Transcription Factors/genetics , Alleles , Animals , Blotting, Northern , Gene Expression Profiling , Genes/genetics , Hair Follicle/metabolism , Mice , Oligonucleotide Array Sequence Analysis , Phenotype
3.
Article in English | MEDLINE | ID: mdl-31078613

ABSTRACT

Inflammation is an essential tissue response to injury, stress, or infection resulting in debris and/or pathogen clearance intended to promote healing and recovery. Due to the status as an immune 'privileged' tissue, microglia serve as endogenous regulators of inflammation in the central nervous system, but maintain communication with peripheral immune system to enable recruitment of peripheral immune cells in case of injury or infection. While microglia retain the functional capacity for a full range of inflammatory functions - microglia express a range of pattern-recognition receptors and function as innate immune cells, carry out phagocytosis of pathogens, and act as antigen presenting cells - in the healthy central nervous system (CNS) these functions are rarely engaged. Subsequently microglia are being recognized to occupy an increasing number of homeostatic niches, and in many cases have adopted immune or inflammatory mechanisms to carry out these niche functions absent immune activation. These sterile inflammatory functions are challenging long-held views of the role of inflammation in the central nervous system while simultaneously expanding the potential for the development of truly novel therapeutic interventions for a range of neuroinflammatory, neurodegenerative, and neuropsychiatric disorders. In the present review we discuss recent preclinical evidence for conserved niche functions for microglia whose disruption may causally contribute to various psychiatric disorders, and prospective targets for restoring disrupted niches.


Subject(s)
Homeostasis/physiology , Inflammation/physiopathology , Mental Disorders/physiopathology , Microglia/physiology , Humans , Mental Disorders/drug therapy
4.
Article in English | MEDLINE | ID: mdl-29643919

ABSTRACT

BACKGROUND: Cats are the major source of indoor inhalant allergens after house dust mites. The global incidence of cat allergies is rising sharply, posing a major public health problem. Ten cat allergens have been identified. The major allergen responsible for symptoms is Fel d 1, a secretoglobin and not a lipocalin, making the cat a special case among mammals. MAIN BODY: Given its clinical predominance, it is essential to have a good knowledge of this allergenic fraction, including its basic structure, to understand the new exciting diagnostic and therapeutic applications currently in development. The recent arrival of the component-resolved diagnosis, which uses molecular allergens, represents a unique opportunity to improve our understanding of the disease. Recombinant Fel d 1 is now available for in vitro diagnosis by the anti-Fel d 1 specific IgE assay. The first part of the review will seek to describe the recent advances related to Fel d 1 in terms of positive diagnosis and assessment of disease severity. In daily practice, anti-Fel d 1 IgE tend to replace those directed against the overall extract but is this attitude justified? We will look at the most recent arguments to try to answer this question. In parallel, a second revolution is taking place thanks to molecular engineering, which has allowed the development of various forms of recombinant Fel d 1 and which seeks to modify the immunomodulatory properties of the molecule and thus the clinical history of the disease via various modalities of anti-Fel d 1-specific immunotherapy. We will endeavor to give a clear and practical overview of all these trends.

5.
Arch Pediatr ; 24(11): 1103-1110, 2017 Nov.
Article in French | MEDLINE | ID: mdl-28965694

ABSTRACT

INTRODUCTION: The aim of this study was to create a specific tool and evaluate its impact on the knowledge of primary care physicians (PCPs) in reporting child abuse to child protective services (CPS). MATERIAL AND METHODS: Prospective "before/after" study assessing the knowledge of general practitioners (GPs) registered at the medical board in a French administrative area through anonymous questionnaires. The tool was adapted from the guidelines published in 2014 by the French Health authorities. The main criterion was the median score (/100) calculated for each questionnaire before (Q1) and after (Q2) the dissemination of the tool. These median scores were compared and associations between scores and some PCPs' characteristics were tested through multiple linear regression. RESULTS: A total of 279 GPs answered the first questionnaire (Q1) and 172 answered the second (Q2). PCPs who answered were mainly women (68% and 74%), were between 30 and 50 years old (61% and 66%), practiced in association with other physicians (82% and 84), and had 15-30% children in their patient population. For Q1, the general median was 65 [IQR: 40-81] versus 82 [IQR: 71-91] for Q2 (P<0.001). The PCPs' characteristics leading to significant variations in the scores for Q1 were age older than 50 years, being female, and having been trained in diagnosis and management of child abuse, with the ß coefficient at -16.4 [95% CI: -31.1; -1.69], +8.93 [95% CI: 2.58; 15.27] and +12 [95% CI: 6.33; 17.73], respectively. DISCUSSION: This study confirms the significant impact of this new tool on PCPs' knowledge concerning reporting suspected child abuse to the CPS. CONCLUSION: Wider dissemination of this tool could increase PCPs' awareness and comprehension of when and how to make a report to the CPS.


Subject(s)
Child Abuse , Child Protective Services , General Practice , Health Knowledge, Attitudes, Practice , Mandatory Reporting , Primary Health Care , Adult , Child , Female , Humans , Male , Middle Aged , Prospective Studies , Self Report
6.
Biochim Biophys Acta ; 1447(1): 107-12, 1999 Oct 06.
Article in English | MEDLINE | ID: mdl-10500250

ABSTRACT

A human homolog(RALY) of the mouse Raly gene was isolated and sequenced, and shown to encode a novel protein isoform containing a 16 amino acid in-frame insert in the variable region of the protein. Analysis of the corresponding region of the mouse Raly gene demonstrated that this novel protein isoform is also present in the mouse. Comparative analysis of RALY cDNA and EST sequences suggests the presence of additional alternatively processed RALY transcripts. As in the mouse, the human RALY gene is widely expressed as a 1.7-kb transcript.


Subject(s)
Alternative Splicing , Heterogeneous-Nuclear Ribonucleoprotein Group C , RNA-Binding Proteins/genetics , Ribonucleoproteins/genetics , Amino Acid Sequence , Animals , DNA, Complementary/chemistry , Expressed Sequence Tags , Humans , Male , Mice , Molecular Sequence Data , Protein Isoforms/chemistry , RNA/chemistry , RNA-Binding Proteins/chemistry , Reverse Transcriptase Polymerase Chain Reaction , Ribonucleoproteins/chemistry , Sequence Alignment , Testis/metabolism
7.
J Med Chem ; 39(20): 3889-96, 1996 Sep 27.
Article in English | MEDLINE | ID: mdl-8831755

ABSTRACT

A series of new 3'-(2-methyl-1-propenyl) and 3'-(2-methylpropyl) taxoids with modifications at C-10 was synthesized by means of the beta-lactam synthon method using 10-modified 7-(triethylsilyl)-10-deacetylbaccatin III derivatives. The new taxoids thus synthesized show excellent cytotoxicity against human ovarian (A121), non-small-cell lung (A549), colon (HT-29), and breast (MCF-7) cancer cell lines. All but one of these new taxoids possess better activity than paclitaxel and docetaxel in the same assay, i.e., the IC50 values of almost all the taxoids are in the subnanomolar level. It is found that a variety of modifications at C-10 is tolerated for the activity against normal cancer cell lines, but the activity against a drug-resistant human breast cancer cell line expressing MDR phenotype (MCF7-R) is highly dependent on the structure of the C-10 modifier. A number of the new taxoids exhibit remarkable activity (IC50 = 2.1-9.1 nM) against MCF7-R. Among these, three new taxoids, SB-T-1213 (4a), SB-T-1214 (4b), and SB-T-1102 (5a), are found to be exceptionally potent, possessing 2 orders of magnitude better activity than paclitaxel and docetaxel. The observed exceptional activity of these taxoids may well be ascribed to an effective inhibition of P-glycoprotein binding by the modified C-10 moieties. The new taxoid SB-T-1213 (4a) shows an excellent activity (T/C = 0% at 12.4 and 7.7 mg/kg/dose, log10 cell kill = 2.3 and 2.0, respectively) against B16 melanoma in B6D2F1 mice via intravenous administration.


Subject(s)
Antineoplastic Agents, Phytogenic/chemical synthesis , Paclitaxel/analogs & derivatives , Taxoids , ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism , Animals , Antineoplastic Agents, Phytogenic/therapeutic use , Breast Neoplasms/drug therapy , Docetaxel , Drug Resistance, Neoplasm , Female , Humans , Melanoma, Experimental/drug therapy , Mice , Mice, Nude , Molecular Structure , Ovarian Neoplasms/drug therapy , Paclitaxel/chemical synthesis , Paclitaxel/therapeutic use , Structure-Activity Relationship , Tumor Cells, Cultured
8.
Mutat Res ; 401(1-2): 11-25, 1998 Jun 05.
Article in English | MEDLINE | ID: mdl-9639665

ABSTRACT

We have developed a new procedure utilizing microhomologous recombination in yeast to generate targeting constructs for producing targeted mutations in mice. This procedure is rapid and efficient, and should be directly applicable to all mammalian genes. Moreover, only minimal information about the locus being targeted is required. The feasibility of this approach was demonstrated by producing another allele of the mouse Tg737 polycystic kidney gene.


Subject(s)
Gene Targeting , Mutagenesis , Polycystic Kidney Diseases/genetics , Recombination, Genetic , Saccharomyces cerevisiae/genetics , Alleles , Animals , Base Sequence , Chimera , Cloning, Molecular/methods , DNA Primers , Exons , Genetic Vectors , Genomic Library , Mammals , Mice , Mice, Inbred Strains , Molecular Sequence Data , Polymerase Chain Reaction , Transformation, Genetic
9.
Rev Med Interne ; 14(1): 54-7, 1993 Jan.
Article in French | MEDLINE | ID: mdl-8395699

ABSTRACT

The authors report two cases of Lambert-Eaton myasthenic syndrome associated with small cell lung carcinoma. Following the observations, the clinical diagnosis of this syndrome is considered. We discuss the autoimmune pathogenesis and the relation between paraneoplastic syndrome and small cell cancer. This syndrome is caused by autoantibodies that block the voltage-dependent calcium channels at motor nerve terminals. Small cell carcinoma cells appear to express calcium channels, suggesting that autoantibody production may be triggered by tumor calcium channels determinants. The autoimmune paraneoplastic syndrome theory refers to cross-antigenicity.


Subject(s)
Carcinoma, Small Cell/complications , Lambert-Eaton Myasthenic Syndrome/etiology , Lung Neoplasms/complications , Paraneoplastic Syndromes , Humans , Lambert-Eaton Myasthenic Syndrome/immunology , Male , Middle Aged
10.
Leukemia ; 26(2): 280-8, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22015772

ABSTRACT

We report the characterization of BMS-911543, a potent and selective small-molecule inhibitor of the Janus kinase (JAK) family member, JAK2. Functionally, BMS-911543 displayed potent anti-proliferative and pharmacodynamic (PD) effects in cell lines dependent upon JAK2 signaling, and had little activity in cell types dependent upon other pathways, such as JAK1 and JAK3. BMS-911543 also displayed anti-proliferative responses in colony growth assays using primary progenitor cells isolated from patients with JAK2(V617F)-positive myeloproliferative neoplasms (MPNs). Similar to these in vitro observations, BMS-911543 was also highly active in in vivo models of JAK2 signaling, with sustained pathway suppression being observed after a single oral dose. At low dose levels active in JAK2-dependent PD models, no effects were observed in an in vivo model of immunosuppression monitoring antigen-induced IgG and IgM production. Expression profiling of JAK2(V617F)-expressing cells treated with diverse JAK2 inhibitors revealed a shared set of transcriptional changes underlying pharmacological effects of JAK2 inhibition, including many STAT1-regulated genes and STAT1 itself. Collectively, our results highlight BMS-911543 as a functionally selective JAK2 inhibitor and support the therapeutic rationale for its further characterization in patients with MPN or in other disorders characterized by constitutively active JAK2 signaling.


Subject(s)
Antineoplastic Agents/pharmacology , Heterocyclic Compounds, 3-Ring/pharmacology , Janus Kinase 2/antagonists & inhibitors , Protein Kinase Inhibitors/pharmacology , Antineoplastic Agents/chemistry , Blotting, Western , Cell Proliferation/drug effects , Gene Expression Profiling , Heterocyclic Compounds, 3-Ring/chemistry , Humans , Myeloproliferative Disorders/enzymology , Myeloproliferative Disorders/pathology , Protein Kinase Inhibitors/chemistry
13.
J Am Dent Assoc ; 98(5): 692-3, 1979 May.
Article in English | MEDLINE | ID: mdl-285979
15.
Cell ; 71(7): 1195-204, 1992 Dec 24.
Article in English | MEDLINE | ID: mdl-1473152

ABSTRACT

The agouti (a) locus acts within the microenvironment of the hair follicle to regulate coat color pigmentation in the mouse. We have characterized a gene encoding a novel 131 amino acid protein that we propose is the one gene associated with the agouti locus. This gene is normally expressed in a manner consistent with a locus function, and, more importantly, its structure and expression are affected by a number of representative alleles in the agouti dominance hierarchy. In addition, we found that the pleiotropic effects associated with the lethal yellow (Ay) mutation, which include pronounced obesity, diabetes, and the development of neoplasms, are accompanied by deregulated overexpression of the agouti gene in numerous tissues of the adult animal.


Subject(s)
Hair Color/genetics , Amino Acid Sequence , Animals , Base Sequence , Exons , Introns , Mice , Mice, Inbred Strains , Molecular Sequence Data , Phenotype
16.
Genes Dev ; 7(7A): 1203-13, 1993 Jul.
Article in English | MEDLINE | ID: mdl-8319910

ABSTRACT

Lethal yellow (Ay) is a mutation at the mouse agouti (a) locus that is associated with an all-yellow coat color, obesity, diabetes, tumors in heterozygotes, and preimplantation embryonic lethality in homozygotes. Previously, we cloned and characterized the wild-type agouti gene and demonstrated that it expresses a 0.8-kb mRNA in neonatal skin. In contrast, Ay expresses a 1.1-kb transcript that is ectopically overexpressed in all tissues examined. The Ay mRNA is identical to the wild-type a transcript for the entire coding region, but the 5'-untranslated sequence of the a gene has been replaced by novel sequence. Here, we demonstrate that the novel 5' sequence in the Ay mRNA corresponds to the 5'-untranslated sequence of another gene that is normally tightly linked to a in mouse chromosome 2. This other gene (Raly) has the potential to encode a novel RNA-binding protein that is normally expressed in the preimplantation embryo, throughout development, and in all adult tissues examined. Importantly, the Ay mutation disrupts the structure and expression of the Raly gene. The data suggest that the Ay mutation arose from a DNA structural alteration that affects the expression of both agouti and Raly. We propose that the dominant pleiotropic effects associated with Ay may result from the ectopic overexpression of the wild-type a gene product under the control of the Raly promoter and that the recessive embryonic lethality may be the result of the lack of Raly gene expression in the early embryo.


Subject(s)
Fetal Death/genetics , Genes, Lethal , Hair Color/genetics , Heterogeneous-Nuclear Ribonucleoprotein Group C , Intercellular Signaling Peptides and Proteins , Mice, Mutant Strains/genetics , RNA-Binding Proteins/genetics , Agouti Signaling Protein , Amino Acid Sequence , Animals , Base Sequence , Gene Expression Regulation , Heterogeneous-Nuclear Ribonucleoproteins , Humans , Immunoblotting , Mice , Mice, Mutant Strains/embryology , Molecular Sequence Data , Mutation/genetics , Proteins/genetics , RNA, Heterogeneous Nuclear , RNA, Messenger/analysis , RNA-Binding Proteins/chemistry , Recombinant Fusion Proteins/chemistry , Recombinant Fusion Proteins/genetics , Ribonucleoproteins , Sequence Homology, Amino Acid
17.
J Colloid Interface Sci ; 209(2): 271-281, 1999 Jan 15.
Article in English | MEDLINE | ID: mdl-9885255

ABSTRACT

The behavior of a nonionic surfactant TX-35 in solution in n-heptane in the presence and absence of added water has been examined using the microcalorimetric, viscosimetric, and quasielastic light scattering experimental methods. In this paper, we were interested in the aggregation process of the poly(oxyethylene) glycol alkylphenyl ether in n-heptane and in the solubilization of water in the reverse micelle of the surfactant (micellar solubilization). The analysis of the differential molar enthalpies of dilution of TX-35 in dried n-heptane has shown the occurrence of a gradual exothermic aggregation process on a very wide range of concentration which takes place at particular concentration so-called "operational CMC". This operational CMC value has been confirmed by viscosities measurements. The differential molar enthalpies of hydration of TX-35 were also measured and found to be exothermic. The maximal hydration ratio (w0) was found to be equal to 3.2 mol H2O per mole of TX-35 before the point of phase separation. The measurements of the variation of the amount of water contained in TX-35 solutions at different concentrations in n-heptane also show the occurence of a gradual aggregation process and confirm the value of the maximal hydration ratio already determined by microcalorimetry. In the absence of added water, from the quasielastic light scattering experiments, a mean diameter of the aggregates close to 45 Å has been determine, while in the presence of water, a mean diameter of 61 Å was detected and remained unchanged with increasing the hydration ratio indicating that the size of the aggregate is more influenced by the presence of water than by the amount. In the presence of water, it is relevant to discuss aggregates of lamellar or filament shape. Copyright 1999 Academic Press.

18.
Genes Dev ; 8(4): 481-90, 1994 Feb 15.
Article in English | MEDLINE | ID: mdl-8125260

ABSTRACT

The agouti gene regulates the differential production of eumelanin (black or brown) and phaeomelanin (yellow) pigment granules by melanocytes in the hair follicles of mice. The original nonagouti (a) allele, which confers a predominantly black coat color, has been shown to revert to two other more dominant agouti alleles, black-and-tan (a(t)) and white-bellied agouti (Aw), with an exceptionally high frequency. The a(t) and Aw alleles confer phenotypes in which the pigmentation is not uniformly distributed over the dorsal and ventral surfaces of the animal; in both cases the ventral surface of the animal is markedly lighter than the dorsal surface due to an increase in phaeomelanin production. To understand the unusually high reversion rate of a to a(t) or Aw, and to decipher the molecular events associated with the different pigmentation patterns associated with these three agouti alleles, we have characterized a, a(t) and Aw at the molecular level. Here, we report that insertions of 11, 6, and 0.6 kb are present at precisely the same position in the first intron of the agouti gene in a, a(t), and Aw, respectively. The a insertion consists of a 5.5-kb VL30 element that has incorporated 5.5 kb of additional sequence internally; this internal sequence is flanked by 526-bp direct repeats. The a(t) allele contains only the VL30 element and a single, internal 526-bp repeat. The Aw allele has only a solo VL30 LTR. Based on the comparison of the structure of the a(t) and Aw insertions, we propose that reverse mutations occur by excision of inserted sequences in a through homologous recombination, utilizing either the 526-bp direct repeats to generate a(t) or the VL30 LTRs to generate Aw. Moreover, the analysis of these three alleles has allowed us to identify additional exons of the agouti gene that give rise to alternatively processed forms of agouti mRNA. We demonstrate that the distinct insertions in a, a(t) and Aw cause pigmentation differences by selectively inactivating the expression of different forms of agouti transcripts.


Subject(s)
Melanins/genetics , Skin Pigmentation/genetics , Alleles , Animals , Base Sequence , DNA/genetics , DNA Mutational Analysis , Gene Rearrangement , Melanins/biosynthesis , Mice , Mice, Inbred C3H , Mice, Inbred C57BL , Molecular Sequence Data , Mutation , RNA, Messenger/genetics , Recombination, Genetic , Repetitive Sequences, Nucleic Acid , Skin Pigmentation/physiology , Transcription, Genetic
19.
Proc Natl Acad Sci U S A ; 96(15): 8579-84, 1999 Jul 20.
Article in English | MEDLINE | ID: mdl-10411918

ABSTRACT

Chronic antagonism of melanocortin receptors by the paracrine-acting agouti gene product induces both yellow fur and a maturity-onset obesity syndrome in mice that ubiquitously express wild-type agouti. Functional analysis of agouti mutations in transgenic mice indicate that the cysteine-rich C terminus, signal peptide, and glycosylation site are required for agouti activity in vivo. In contrast, no biological activity has been ascribed to the conserved basic domain. To examine the functional significance of the agouti basic domain, the entire 29-aa region was deleted from the agouti cDNA, and the resulting mutation (agoutiDeltabasic) was expressed in transgenic mice under the control of the beta-actin promoter (BAPaDeltabasic). Three independent lines of BAPaDeltabasic transgenic mice all developed some degree of yellow pigment in the fur, indicating that the agoutiDeltabasic protein was functional in vivo. However, none of the BAPaDeltabasic transgenic mice developed completely yellow fur, obesity, hyperinsulinemia, or hyperglycemia. High levels of agoutiDeltabasic expression in relevant tissues exceeded the level of agouti expression in obese viable yellow mice, suggesting that suboptimal activity or synthesis of the agoutiDeltabasic protein, rather than insufficient RNA synthesis, accounts for the phenotype of the BAPaDeltabasic transgenic mice. These findings implicate a functional role for the agouti basic domain in vivo, possibly influencing the biogenesis of secreted agouti protein or modulating protein-protein interactions that contribute to effective antagonism of melanocortin receptors.


Subject(s)
Intercellular Signaling Peptides and Proteins , Obesity/genetics , Pigmentation/genetics , Proteins/genetics , Agouti Signaling Protein , Animals , Body Weight , Gene Dosage , Gene Expression/genetics , Glycosylation , Mice , Mice, Transgenic , Mutation , Phenotype , Promoter Regions, Genetic , Protein Sorting Signals/genetics , RNA/analysis , Receptors, Corticotropin/antagonists & inhibitors , Receptors, Melanocortin , Sequence Deletion , Skin/metabolism
20.
Genes Dev ; 8(12): 1463-72, 1994 Jun 15.
Article in English | MEDLINE | ID: mdl-7926745

ABSTRACT

The agouti gene normally confers the wild-type coat color of mice. Dominant mutations at the agouti locus result in a pleiotropic syndrome that is characterized by excessive amounts of yellow pigment in the coat, obesity, a non-insulin-dependent diabetic-like condition, and the propensity to form a variety of tumors. Here, we describe a new dominant mutation at the agouti locus in which an intracisternal A-particle (IAP) has integrated in an antisense orientation immediately 5' of the first coding exon of the gene. This mutation, which we have named Aiapy, results in the ectopic expression of the agouti gene through the utilization of a cryptic promoter within the IAP 5' long terminal repeat (LTR). The coat color of Aiapy/-mice ranges from solid yellow to a pigment pattern that is similar to wild type (pseudoagouti), and the expressivity of this mutant phenotype varies with parental inheritance. Those offspring with a yellow coat ectopically express agouti mRNA at high levels and exhibit marked obesity, whereas pseudoagouti mice express agouti mRNA at a very low level and their weights do not differ from wild-type littermates. Data are presented to show that the differential expressivity of the Aiapy allele is correlated with the methylation status of the inserted IAP 5' LTR. These data further support the hypothesis that in dominant yellow mutations at the agouti locus, it is the ubiquitous expression of the wild-type agouti coding sequence that is responsible for the yellow coat color, obesity, diabetes, and tumorigenesis.


Subject(s)
Gene Expression Regulation , Genes, Intracisternal A-Particle/genetics , Genomic Imprinting/genetics , Intercellular Signaling Peptides and Proteins , Pigmentation/genetics , Proteins/genetics , Agouti Signaling Protein , Alleles , Animals , Base Sequence , DNA, Antisense , Gene Rearrangement , Genes, Dominant/genetics , Mice , Mice, Inbred C3H , Mice, Inbred C57BL , Molecular Sequence Data , Mutation , Promoter Regions, Genetic , Repetitive Sequences, Nucleic Acid/genetics , Tissue Distribution , Transcription, Genetic
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