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1.
Pediatr Pulmonol ; 59(1): 95-100, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37796090

ABSTRACT

OBJECTIVE: Patients with cystic fibrosis (CF) often bring education-related concerns to their medical teams. Concerns around the ability for CF care teams to identify and address these concerns exist. We sought to describe CF care team perceptions of (1) patient and family education-related needs, (2) how these needs are identified, documented and addressed, and (3) education-related resource gaps. METHODS: A survey was emailed to pediatric care teams in the CF Foundation Care Center Network in April 2022. Individuals or care teams could complete the survey. Responses were aggregated for descriptive analysis. RESULTS: Sixty-seven programs responded representing 52% of United States pediatric CF centers. Most centers (88%) indicated social workers primarily address school concerns. Care teams often complete school forms (99%), coach families to communicate with schools (96%), communicate with schools directly (90%), and develop educational plans (76%). Formal education risk assessment and support programs are relatively uncommon (19%). Common student-specific needs include carrying medications (75%) and leaving class for gastrointestinal issues (54%). Needs reported are informational materials for families and schools (94%), staff education about school concerns and how to address them (91%), additional staff for education-related issues (65%), and expertise in education plan development (62%). CONCLUSION: CF care teams often lack comprehensive resources to identify and address education-related concerns. Systematically performing needs assessments, improving training for providers, and evaluating the benefits of education specialists on care teams may better identify and address education-related needs. Supporting educational progression will foster continued independence and well-being in adulthood.


Subject(s)
Cystic Fibrosis , Humans , Child , United States , Cystic Fibrosis/therapy , Schools , Surveys and Questionnaires , Students , Patient Care Team
2.
Chem Sci ; 14(27): 7524-7536, 2023 Jul 12.
Article in English | MEDLINE | ID: mdl-37449080

ABSTRACT

Knowledge of protein dynamics is fundamental to the understanding of biological processes, with NMR and 2D-IR spectroscopy being two of the principal methods for studying protein dynamics. Here, we combine these two methods to gain a new understanding of the complex mechanism of a cytokine:receptor interaction. The dynamic nature of many cytokines is now being recognised as a key property in the signalling mechanism. Interleukin-17s (IL-17) are proinflammatory cytokines which, if unregulated, are associated with serious autoimmune diseases such as psoriasis, and although there are several therapeutics on the market for these conditions, small molecule therapeutics remain elusive. Previous studies, exploiting crystallographic methods alone, have been unable to explain the dramatic differences in affinity observed between IL-17 dimers and their receptors, suggesting there are factors that cannot be fully explained by the analysis of static structures alone. Here, we show that the IL-17 family of cytokines have varying degrees of flexibility which directly correlates to their receptor affinities. Small molecule inhibitors of the cytokine:receptor interaction are usually thought to function by either causing steric clashes or structural changes. However, our results, supported by other biophysical methods, provide evidence for an alternate mechanism of inhibition, in which the small molecule rigidifies the protein, causing a reduction in receptor affinity. The results presented here indicate an induced fit model of cytokine:receptor binding, with the more flexible cytokines having a higher affinity. Our approach could be applied to other systems where the inhibition of a protein-protein interaction has proved intractable, for example due to the flat, featureless nature of the interface. Targeting allosteric sites which modulate protein dynamics, opens up new avenues for novel therapeutic development.

3.
Genetics ; 224(4)2023 08 09.
Article in English | MEDLINE | ID: mdl-37098137

ABSTRACT

Sturge-Weber Syndrome (SWS) is a sporadic (non-inherited) syndrome characterized by capillary vascular malformations in the facial skin, leptomeninges, or the choroid. A hallmark feature is the mosaic nature of the phenotype. SWS is caused by a somatic mosaic mutation in the GNAQ gene (p.R183Q), leading to activation of the G protein, Gαq. Decades ago, Rudolf Happle hypothesized SWS as an example of "paradominant inheritance", that is, a "lethal gene (mutation) surviving by mosaicism". He predicted that the "presence of the mutation in the zygote will lead to death of the embryo at an early stage of development". We have created a mouse model for SWS using gene targeting to conditionally express the GNAQ p.R183Q mutation. We have employed two different Cre-drivers to examine the phenotypic effects of expression of this mutation at different levels and stages of development. As predicted by Happle, global, ubiquitous expression of this mutation in the blastocyst stage results in 100% embryonic death. The majority of these developing embryos show vascular defects consistent with the human vascular phenotype. By contrast, global but mosaic expression of the mutation enables a fraction of the embryos to survive, but those that survive to birth and beyond do not exhibit obvious vascular defects. These data validate Happle's paradominant inheritance hypothesis for SWS and suggest the requirement of a tight temporal and developmental window of mutation expression for the generation of the vascular phenotype. Furthermore, these engineered murine alleles provide the template for the development of a mouse model of SWS that acquires the somatic mutation during embryonic development, but permits the embryo to progress to live birth and beyond, so that postnatal phenotypes can also be investigated. These mice could then also be employed in pre-clinical studies of novel therapies.


Subject(s)
Sturge-Weber Syndrome , Vascular Malformations , Animals , Humans , Male , Mice , Capillaries/metabolism , Mutation , Sturge-Weber Syndrome/genetics , Sturge-Weber Syndrome/metabolism , Sturge-Weber Syndrome/therapy , Vascular Malformations/genetics
4.
J Pediatr ; 253: 238-244.e3, 2023 02.
Article in English | MEDLINE | ID: mdl-36202239

ABSTRACT

OBJECTIVES: To assess the use of services provided by a cystic fibrosis (CF) center school specialist and evaluate relationships among student educational risk scores, family concerns for school engagement and performance, and disease severity. STUDY DESIGN: This was a retrospective review of medical records for 126 children with CF in grades K-12 who were screened for educational risk or used school intervention services during the 2017- 020 school years. Regression analyses were performed to identify and quantify predictors of educational risk, family concern for school performance and ability to advocate, and use of school specialist services. RESULTS: Most children with CF (62%-82%) were at moderate-to-high educational risk. Sixteen or more school absences, family concerns for their child's school performance or inability to advocate for their school needs, child mental health visits, and greater frequency of hospitalization predicted greater educational risk scores and more encounters with the school specialist. Better lung function and lower grade level were associated with lower educational risk. Number of encounters with the School Specialist remained high across three pre-coronavirus disease 2019 school years. CONCLUSIONS: Our experience illustrates a need to identify educational risk and support school experiences of children and youth with CF as a component of the care model. Tailored support, based on identification of risk predictors, has potential to improve educational outcomes.


Subject(s)
COVID-19 , Cystic Fibrosis , Child , Adolescent , Humans , Child, Preschool , Cystic Fibrosis/therapy , Educational Status , Students , Schools
5.
Orphanet J Rare Dis ; 16(1): 372, 2021 09 03.
Article in English | MEDLINE | ID: mdl-34479577

ABSTRACT

BACKGROUND: Vascular malformations in the central nervous system are difficult to monitor and treat due to their inaccessible location. Angiogenic and inflammatory proteins are secreted into the bloodstream and may serve as useful biomarkers for identifying patients at risk for complications or with certain disease phenotypes. METHODS: A validated multiplex protein array consisting of 26 angiogenic and inflammatory biomarkers (Angiome) was assessed in plasma isolated from healthy controls and patients with either sporadic brain arteriovenous malformation (BAVM), familial cerebral cavernous malformation (CCM), or hereditary hemorrhagic telangiectasia (HHT). These samples were obtained from archives of ongoing research studies at the University of California San Francisco and through prospective collection at the Toronto HHT Centre at St. Michael's Hospital. RESULTS: We compared circulating biomarker levels from each patient group to healthy controls and analyzed each pairwise combination of patient groups for differences in biomarker levels. Additionally, we analyzed the HHT samples to determine the association between biomarker levels and the following HHT-specific phenotypes, BAVM, pulmonary arteriovenous malformation (PAVM), liver vascular malformation (LVM), and gastrointestinal (GI) bleeding. Compared to controls, levels of SDF1 were significantly elevated in HHT patients (Proportional Increase [PI] = 1.87, p < 0.001, q = 0.011). Levels of sENG were significantly reduced in HHT patients compared to controls (PI = 0.56, p < 0.001, q < 0.001), reflecting the prevalence of HHT1 patients in this cohort. Levels of IL6 (PI = 3.22, p < 0.001, q < 0.001) and sTGFßR3 (PI = 0.70, p = 0.001, q < 0.029) differed significantly in CCM patients compared to controls. Compared to controls, ten of the biomarkers were significantly different in sporadic BAVM patients (q-values < 0.05). Among the pairwise combinations of patient groups, a significant elevation was observed in TGFß1 in CCM patients compared to sporadic BAVM patients (PI = 2.30, p < 0.001, q = 0.034). When examining the association of circulating biomarker levels with HHT-specific phenotypes, four markers were significantly lower in HHT patients with BAVM (q-values < 0.05), and four markers were significantly higher in patients with LVM (q-values < 0.05). CONCLUSIONS: This pilot study suggests that the profile of circulating angiogenic and inflammatory biomarkers may be unique to each type of vascular malformation. Furthermore, this study indicates that circulating biomarkers may be useful for assessing phenotypic traits of vascular malformations.


Subject(s)
Intracranial Arteriovenous Malformations , Telangiectasia, Hereditary Hemorrhagic , Vascular Malformations , Biomarkers , Humans , Pilot Projects , Prospective Studies
6.
Front Neurosci ; 15: 705160, 2021.
Article in English | MEDLINE | ID: mdl-34408625

ABSTRACT

Although studies with inbred strains of mice have shown that infarct size is largely determined by the extent of collateral vessel connections between arteries in the brain that enable reperfusion of the ischemic territory, we have identified strain pairs that do not vary in this vascular phenotype, but which nonetheless exhibit large differences in infarct size. In this study we performed quantitative trait locus (QTL) mapping in mice from an intercross between two such strains, WSB/EiJ (WSB) and C57BL/6J (B6). This QTL mapping revealed only one neuroprotective locus on Chromosome 8 (Chr 8) that co-localizes with a neuroprotective locus we mapped previously from F2 progeny between C3H/HeJ (C3H) and B6. The allele-specific phenotypic effect on infarct volume at the genetic region identified by these two independent mappings was in the opposite direction of the parental strain phenotype; namely, the B6 allele conferred increased susceptibility to ischemic infarction. Through two reciprocal congenic mouse lines with either the C3H or B6 background at the Chr 8 locus, we verified the neuroprotective effects of this genetic region that modulates infarct volume without any effect on the collateral vasculature. Additionally, we surveyed non-synonymous coding SNPs and performed RNA-sequencing analysis to identify potential candidate genes within the genetic interval. Through these approaches, we suggest new genes for future mechanistic studies of infarction following ischemic stroke, which may represent novel gene/protein targets for therapeutic development.

7.
Cytokine ; 142: 155476, 2021 06.
Article in English | MEDLINE | ID: mdl-33706174

ABSTRACT

The proinflammatory cytokines IL-17A and IL-17F have been identified as key drivers of a range of human inflammatory diseases, such as psoriasis, which has led to several therapeutic antibodies targeted at IL-17A. The two cytokines have been shown to tightly associate as functional homo and hetero dimers, which induce signalling via the formation of a cell surface signalling complex with a single copy of both IL-17RA and IL-17RC. Striking differences in affinity have been observed for IL-17RA binding to IL-17AA, IL-17AF and IL-17FF, however, the functional significance and molecular basis for this has remained unclear. We have obtained comprehensive backbone NMR assignments for full length IL-17AA (79%), IL-17AF (93%) and IL-17FF (89%), which show that the dimers adopt almost identical backbone topologies in solution to those observed in reported crystal structures. Analysis of the line widths and intensities of assigned backbone amide NMR signals has revealed striking differences in the conformational plasticity and dynamics of IL-17AA compared to both IL-17AF and IL-17FF. Our NMR data indicate that a number of regions of IL-17AA are interconverting between at least two distinct conformations on a relatively slow timescale. Such conformational heterogeneity has previously been shown to play an important role in the formation of many high affinity protein-protein complexes. The locations of the affected IL-17AA residues essentially coincides with the regions of both IL-17A and IL-17F previously shown to undergo significant structural changes on binding to IL-17RA. Substantially less conformational exchange was revealed by the NMR data for IL-17FF and IL-17AF. We propose that the markedly different conformational dynamic properties of the distinct functional IL-17 dimers plays a key role in determining their affinities for IL-17RA, with the more dynamic and plastic nature of IL-17AA contributing to the significantly tighter affinity observed for binding to IL-17RA. In contrast, the dynamic properties are expected to have little influence on the affinity of IL-17 dimers for IL-17RC, which has recently been shown to induce only small structural changes in IL-17FF upon binding.


Subject(s)
Interleukin-17/chemistry , Interleukin-17/metabolism , Receptors, Interleukin-17/metabolism , Amino Acid Sequence , Humans , Magnetic Resonance Spectroscopy , Models, Molecular , Protein Binding , Protein Conformation , Protein Multimerization
8.
J Pediatr ; 230: 182-190, 2021 03.
Article in English | MEDLINE | ID: mdl-33275983

ABSTRACT

OBJECTIVES: To describe the academic concerns and risk strata of children with sickle cell disease (SCD) as identified through a parent-directed screening tool and to compare the rates of these concerns with actual school service utilization in the clinic population. STUDY DESIGN: We completed a retrospective review of patients with SCD referred to the school intervention program during the 2017-2018 and 2018-2019 school years because of a school-related concern raised by parents or noted by the clinical team. All parents completed the Brief School Needs Inventory (BSNI), a validated parent-response tool used to stratify academic risk. Rates of special education services, grade retention, and results from neuropsychologic testing were captured. Clinical history, the use of disease-modifying therapy, and results from laboratory and neuroimaging studies were also obtained. Descriptive statistics were performed to examine demographic information, clinical history, and BSNI results. RESULTS: In total, 137 unique patients (age range, 14 months to 19 years) completed the BSNI during the study period, for 181 events. According to BSNI risk-stratification, 45% of patients were deemed low, 36% moderate, and 19% high academic risk. Over one-half of parents were concerned about their ability to advocate for their child's needs. Despite legal qualification for a Section 504 accommodation plan, only 20% had established plans. Academic concerns were common with 31% of children reporting an individualized education program and 20% with grade retention/remediation. CONCLUSIONS: Concerns for academic challenges remain high among parents of children with SCD; however, school service utilization remains disproportionately low attributable to numerous reasons.


Subject(s)
Anemia, Sickle Cell/therapy , Facilities and Services Utilization/statistics & numerical data , School Health Services/statistics & numerical data , Adolescent , Child , Child, Preschool , Educational Status , Female , Humans , Infant , Male , Retrospective Studies , Risk Assessment
9.
J Biol Chem ; 293(31): 12149-12166, 2018 08 03.
Article in English | MEDLINE | ID: mdl-29925589

ABSTRACT

Dickkopf (Dkk) family proteins are important regulators of Wnt signaling pathways, which play key roles in many essential biological processes. Here, we report the first detailed structural and dynamics study of a full-length mature Dkk protein (Dkk4, residues 19-224), including determination of the first atomic-resolution structure for the N-terminal cysteine-rich domain (CRD1) conserved among Dkk proteins. We discovered that CRD1 has significant structural homology to the Dkk C-terminal cysteine-rich domain (CRD2), pointing to multiple gene duplication events during Dkk family evolution. We also show that Dkk4 consists of two independent folded domains (CRD1 and CRD2) joined by a highly flexible, nonstructured linker. Similarly, the N-terminal region preceding CRD1 and containing a highly conserved NXI(R/K) sequence motif was shown to be dynamic and highly flexible. We demonstrate that Dkk4 CRD2 mediates high-affinity binding to both the E1E2 region of low-density lipoprotein receptor-related protein 6 (LRP6 E1E2) and the Kremen1 (Krm1) extracellular domain. In contrast, the N-terminal region alone bound with only moderate affinity to LRP6 E1E2, consistent with binding via the conserved NXI(R/K) motif, but did not interact with Krm proteins. We also confirmed that Dkk and Krm family proteins function synergistically to inhibit Wnt signaling. Insights provided by our integrated structural, dynamics, interaction, and functional studies have allowed us to refine the model of synergistic regulation of Wnt signaling by Dkk proteins. Our results indicate the potential for the formation of a diverse range of ternary complexes comprising Dkk, Krm, and LRP5/6 proteins, allowing fine-tuning of Wnt-dependent signaling.


Subject(s)
Intercellular Signaling Peptides and Proteins/chemistry , Intercellular Signaling Peptides and Proteins/metabolism , Membrane Proteins/metabolism , Amino Acid Sequence , Humans , Intercellular Signaling Peptides and Proteins/genetics , Low Density Lipoprotein Receptor-Related Protein-6/genetics , Low Density Lipoprotein Receptor-Related Protein-6/metabolism , Membrane Proteins/chemistry , Membrane Proteins/genetics , Protein Binding , Protein Domains , Sequence Alignment , Wnt Signaling Pathway
11.
J Affect Disord ; 207: 346-352, 2017 Jan 01.
Article in English | MEDLINE | ID: mdl-27743537

ABSTRACT

BACKGROUND: Cognitive dysfunction occurs in depression and can persist into remission. It impacts on patient functioning but remains largely unrecognised, unmonitored and untreated. We explored understanding of cognitive dysfunction in depression among UK clinicians. METHODS: A multi-step consultation process. Step 1: a multi-stakeholder steering committee identified key themes of burden, detection and management of cognitive dysfunction in depression, and developed statements on each to explore understanding and degree of agreement among clinicians. Step 2: 100 general practitioners (GPs) and 100 psychiatrists indicated their level of agreement with these statements. Step 3: the steering committee reviewed responses and highlighted priority areas for future education and research. RESULTS: There was agreement that clinicians are not fully aware of cognitive dysfunction in depression. Views of the relationship between cognitive dysfunction and other depressive symptom severities was not consistent with the literature. In particular, there was a lack of recognition that some cognitive dysfunction can persist into remission. There was understandable uncertainty around treatment options, given the current limited evidence base. However, it was recognised that cognitive dysfunction is an area of unmet need and that there is a lack of objective tests of cognition appropriate for depressed patients that can be easily implemented in the clinic. LIMITATIONS: Respondents are likely to be 'led' by the direction of the statements they reviewed. The study did not involve patients and carers. CONCLUSIONS: UK clinicians should undergo training regarding cognitive dysfunction in depression, and further research is needed into its assessment, treatment and monitoring.


Subject(s)
Attitude of Health Personnel , Cognition , Depressive Disorder, Major/diagnosis , Physicians, Primary Care , Practice Patterns, Physicians' , Adult , Attitude to Health , Awareness , Female , Humans , Male , Middle Aged , Referral and Consultation , United Kingdom
12.
J Pathol ; 241(2): 281-293, 2017 Jan.
Article in English | MEDLINE | ID: mdl-27859310

ABSTRACT

Vascular malformations may arise in any of the vascular beds present in the human body. These lesions vary in location, type, and clinical severity of the phenotype. In recent years, the genetic basis of several vascular malformations has been elucidated. This review will consider how the identification of the genetic factors contributing to different vascular malformations, with subsequent functional studies in animal models, has provided a better understanding of these factors that maintain vascular integrity in vascular beds, as well as their role in the pathogenesis of vascular malformations. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.


Subject(s)
Endothelial Cells/metabolism , Genetic Predisposition to Disease , Organisms, Genetically Modified , Transforming Growth Factor beta2/metabolism , Vascular Malformations/pathology , Vascular Malformations/physiopathology , Animals , Humans , Models, Animal
13.
Hypertension ; 68(3): 667-77, 2016 09.
Article in English | MEDLINE | ID: mdl-27402918

ABSTRACT

RAMPs (receptor activity-modifying proteins) serve as oligomeric modulators for numerous G-protein-coupled receptors, yet elucidating the physiological relevance of these interactions remains complex. Ramp2 null mice are embryonic lethal, with cardiovascular developmental defects similar to those observed in mice null for canonical adrenomedullin/calcitonin receptor-like receptor signaling. We aimed to genetically rescue the Ramp2(-/-) lethality in order to further delineate the spatiotemporal requirements for RAMP2 function during development and thereby enable the elucidation of an expanded repertoire of RAMP2 functions with family B G-protein-coupled receptors in adult homeostasis. Endothelial-specific expression of Ramp2 under the VE-cadherin promoter resulted in the partial rescue of Ramp2(-/-) mice, demonstrating that endothelial expression of Ramp2 is necessary and sufficient for survival. The surviving Ramp2(-/-) Tg animals lived to adulthood and developed spontaneous hypotension and dilated cardiomyopathy, which was not observed in adult mice lacking calcitonin receptor-like receptor. Yet, the hearts of Ramp2(-/-) Tg animals displayed dysregulation of family B G-protein-coupled receptors, including parathyroid hormone and glucagon receptors, as well as their downstream signaling pathways. These data suggest a functional requirement for RAMP2 in the modulation of additional G-protein-coupled receptor pathways in vivo, which is critical for sustained cardiovascular homeostasis. The cardiovascular importance of RAMP2 extends beyond the endothelium and canonical adrenomedullin/calcitonin receptor-like receptor signaling, in which future studies could elucidate novel and pharmacologically tractable pathways for treating cardiovascular diseases.


Subject(s)
Cardiomyopathy, Dilated/mortality , Cardiomyopathy, Dilated/pathology , Receptor Activity-Modifying Protein 2/metabolism , Receptors, Adrenomedullin/metabolism , Analysis of Variance , Animals , Cardiomyopathy, Dilated/genetics , Disease Models, Animal , Homeostasis/physiology , Membrane Proteins/metabolism , Mice , Mice, Inbred C57BL , Mice, Transgenic , Myocardium/metabolism , Random Allocation , Receptors, Adrenomedullin/genetics , Signal Transduction , Statistics, Nonparametric , Survivors
14.
Am J Physiol Regul Integr Comp Physiol ; 310(2): R209-16, 2016 Jan 15.
Article in English | MEDLINE | ID: mdl-26582637

ABSTRACT

Estrogen regulates the expression of many genes and has been correlated with differences in cardiac contraction; however, the underlying mechanisms remain poorly defined. Adrenomedullin (Adm = gene; AM = protein) is a multifunctional peptide with inotropic actions. Previous studies have demonstrated that estrogen enhances the expression of Adm, suggesting a relationship between AM and estrogen in cardiac contraction during physiological and pathological states. In this study, female mice in a mouse model of genetic Adm overexpression, abbreviated as Adm(hi/hi), were found to express 60 times more Adm in the heart than wild-type littermates, compared with the three-fold elevation of Adm previously reported in Adm(hi/hi) male hearts. Thus, this study sought to further investigate any functional consequences of increased cardiac Adm expression and begin exploring the mechanisms that regulate Adm expression in an estrogen-dependent fashion. This study revealed that heart function is enhanced in Adm(hi/hi) females, which along with Adm expression levels, was reversed following ovariectomization. Since the Adm(hi/hi) line was generated by the displacement of the 3' untranslated region (UTR), the native 3'UTR was examined for estrogen-induced microRNAs target sites to potentially explain the aberrant overexpression observed in Adm(hi/hi) female hearts. Using a bioinformatic approach, it was determined that the mouse Adm 3'UTR contains many target sites for previously characterized estrogen-induced microRNAs. This study also determined that the novel microRNA, miR-879, is another estrogen-induced microRNA that interacts with the 3'UTR of Adm to destabilize the mRNA. Together, these studies revealed that estrogen-induced microRNAs are important for balancing cardiac Adm expression in females.


Subject(s)
Adrenomedullin/metabolism , Estrogens/metabolism , MicroRNAs/metabolism , Myocardium/metabolism , 3' Untranslated Regions , 5' Untranslated Regions , Adrenomedullin/genetics , Animals , Binding Sites , Computational Biology , Databases, Genetic , Female , Gene Expression Profiling , Genotype , Growth Hormone/genetics , Hemodynamics , Mice, 129 Strain , Mice, Inbred C57BL , Mice, Transgenic , MicroRNAs/genetics , Myocardial Contraction , Ovariectomy , Phenotype , Signal Transduction , Up-Regulation , Ventricular Function, Left
15.
PLoS One ; 9(7): e102356, 2014.
Article in English | MEDLINE | ID: mdl-25010197

ABSTRACT

Asthma is a chronic inflammatory disease affecting the lung, characterized by breathing difficulty during an attack following exposure to an environmental trigger. Calcitonin gene-related peptide (CGRP) is a neuropeptide that may have a pathological role in asthma. The CGRP receptor is comprised of two components, which include the G-protein coupled receptor, calcitonin receptor-like receptor (CLR), and receptor activity-modifying protein 1 (RAMP1). RAMPs, including RAMP1, mediate ligand specificity in addition to aiding in the localization of receptors to the cell surface. Since there has been some controversy regarding the effect of CGRP on asthma, we sought to determine the effect of CGRP signaling ablation in an animal model of asthma. Using gene-targeting techniques, we generated mice deficient for RAMP1 by excising exon 3. After determining that these mice are viable and overtly normal, we sensitized the animals to ovalbumin prior to assessing airway resistance and inflammation after methacholine challenge. We found that mice lacking RAMP1 had reduced airway resistance and inflammation compared to wildtype animals. Additionally, we found that a 50% reduction of CLR, the G-protein receptor component of the CGRP receptor, also ameliorated airway resistance and inflammation in this model of allergic asthma. Interestingly, the loss of CLR from the smooth muscle cells did not alter the airway resistance, indicating that CGRP does not act directly on the smooth muscle cells to drive airway hyperresponsiveness. Together, these data indicate that signaling through RAMP1 and CLR plays a role in mediating asthma pathology. Since RAMP1 and CLR interact to form a receptor for CGRP, our data indicate that aberrant CGRP signaling, perhaps on lung endothelial and inflammatory cells, contributes to asthma pathophysiology. Finally, since RAMP-receptor interfaces are pharmacologically tractable, it may be possible to develop compounds targeting the RAMP1/CLR interface to assist in the treatment of asthma.


Subject(s)
Asthma/genetics , Calcitonin Gene-Related Peptide/metabolism , Calcitonin Receptor-Like Protein/genetics , Receptor Activity-Modifying Protein 1/metabolism , Animals , Asthma/pathology , Calcitonin Gene-Related Peptide/genetics , Calcitonin Receptor-Like Protein/metabolism , Disease Models, Animal , Humans , Inflammation/genetics , Inflammation/metabolism , Inflammation/pathology , Lung/metabolism , Lung/pathology , Mice , Myocytes, Smooth Muscle/metabolism , Myocytes, Smooth Muscle/pathology , Receptor Activity-Modifying Protein 1/genetics , Signal Transduction/genetics
16.
Dev Dyn ; 243(2): 243-56, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24123312

ABSTRACT

BACKGROUND: Growth promoting signals from the epicardium are essential for driving myocardial proliferation during embryogenesis. In adults, these signals become reactivated following injury and promote angiogenesis and myocardial repair. Therefore, identification of such paracrine factors could lead to novel therapeutic strategies. The multi-functional peptide adrenomedullin (Adm 5 gene, AM 5 protein) is required for normal heart development. Moreover, elevated plasma AM following myocardial infarction offers beneficial cardioprotection and serves as a powerful diagnostic and prognostic indication of disease severity. RESULTS: Here, we developed a new model of Adm overexpression by stabilizing the Adm mRNA through gene-targeted replacement of the endogenous 30 untranslated region. As expected, Admhi/hi mice express three-times more AM than controls in multiple tissues, including the heart. Despite normal blood pressures, Admhi/hi mice unexpectedly showed significantly enlarged hearts due to increased cardiac hyperplasia during development. The targeting vector was designed to allow for reversion to wild-type levels by means of Cre-mediated modification. Using this approach, we demonstrate that AM derived from the epicardium, but not the myocardium or cardiac fibroblast, is responsible for driving cardiomyocyte hyperplasia. CONCLUSIONS: AM is produced by the epicardium and drives myocyte proliferation during development, thus representing a novel and clinically relevant factor potentially related to mechanisms of cardiac repair after injury.


Subject(s)
Adrenomedullin/metabolism , Heart/embryology , Myocardium/pathology , Pericardium/metabolism , RNA Stability/genetics , Signal Transduction/physiology , Adrenomedullin/genetics , Animals , Blotting, Western , Bromodeoxyuridine , Cell Cycle/physiology , DNA Primers/genetics , Genetic Vectors/genetics , Hyperplasia/genetics , Hyperplasia/metabolism , Mice , Mice, Mutant Strains , Myocytes, Cardiac/physiology , Real-Time Polymerase Chain Reaction
17.
Bioorg Med Chem Lett ; 22(6): 2338-42, 2012 Mar 15.
Article in English | MEDLINE | ID: mdl-22342142

ABSTRACT

The enzyme S-nitrosoglutathione reductase (GSNOR) is a member of the alcohol dehydrogenase family (ADH) that regulates the levels of S-nitrosothiols (SNOs) through catabolism of S-nitrosoglutathione (GSNO). GSNO and SNOs are implicated in the pathogenesis of many diseases including those in respiratory, gastrointestinal, and cardiovascular systems. The pyrrole based N6022 was recently identified as a potent, selective, reversible, and efficacious GSNOR inhibitor which is currently in clinical development for acute asthma. We describe here the synthesis and structure-activity relationships (SAR) of novel pyrrole based analogs of N6022 focusing on carboxamide modifications on the pendant N-phenyl moiety. We have identified potent and novel GSNOR inhibitors that demonstrate efficacy in an ovalbumin (OVA) induced asthma model in mice.


Subject(s)
Aldehyde Oxidoreductases/antagonists & inhibitors , Anti-Asthmatic Agents/chemical synthesis , Asthma/drug therapy , Benzamides/chemical synthesis , Enzyme Inhibitors/chemical synthesis , Pyrroles/chemical synthesis , Acute Disease , Aldehyde Oxidoreductases/metabolism , Animals , Anti-Asthmatic Agents/administration & dosage , Anti-Asthmatic Agents/therapeutic use , Asthma/chemically induced , Asthma/enzymology , Benzamides/administration & dosage , Benzamides/therapeutic use , Enzyme Inhibitors/administration & dosage , Enzyme Inhibitors/therapeutic use , Humans , Male , Mice , Ovalbumin , Pyrroles/administration & dosage , Pyrroles/therapeutic use , S-Nitrosoglutathione/metabolism , S-Nitrosothiols/metabolism , Structure-Activity Relationship
18.
PLoS One ; 7(12): e52906, 2012.
Article in English | MEDLINE | ID: mdl-23300815

ABSTRACT

The transcription factor B-Myb is a key regulator of the cell cycle in vertebrates, with activation of transcription involving the recognition of specific DNA target sites and the recruitment of functional partner proteins, including the coactivators p300 and CBP. Here we report the results of detailed studies of the interaction between the transactivation domain of B-Myb (B-Myb TAD) and the TAZ2 domain of p300. The B-Myb TAD was characterized using circular dichroism, fluorescence and NMR spectroscopy, which revealed that the isolated domain exists as a random coil polypeptide. Pull-down and spectroscopic experiments clearly showed that the B-Myb TAD binds to p300 TAZ2 to form a moderately tight (K(d) ~1.0-10 µM) complex, which results in at least partial folding of the B-Myb TAD. Significant changes in NMR spectra of p300 TAZ2 suggest that the B-Myb TAD binds to a relatively large patch on the surface of the domain (~1200 Å(2)). The apparent B-Myb TAD binding site on p300 TAZ2 shows striking similarity to the surface of CBP TAZ2 involved in binding to the transactivation domain of the transcription factor signal transducer and activator of transcription 1 (STAT1), which suggests that the structure of the B-Myb TAD-p300 TAZ2 complex may share many features with that reported for STAT1 TAD-p300 TAZ2.


Subject(s)
Cell Cycle Proteins/metabolism , E1A-Associated p300 Protein/metabolism , Trans-Activators/metabolism , Circular Dichroism , Humans , Phosphorylation , Protein Structure, Tertiary
19.
Bioorg Med Chem Lett ; 21(19): 5849-53, 2011 Oct 01.
Article in English | MEDLINE | ID: mdl-21855338

ABSTRACT

The pyrrole based N6022 was recently identified as a potent, selective, reversible, and efficacious S-nitrosoglutathione reductase (GSNOR) inhibitor and is currently undergoing clinical development for the treatment of acute asthma. GSNOR is a member of the alcohol dehydrogenase family (ADH) and regulates the levels of S-nitrosothiols (SNOs) through catabolism of S-nitrosoglutathione (GSNO). Reduced levels of GSNO, as well as other nitrosothiols (SNOs), have been implicated in the pathogenesis of many diseases including those of the respiratory, cardiovascular, and gastrointestinal systems. Preservation of endogenous SNOs through GSNOR inhibition presents a novel therapeutic approach with broad applicability. We describe here the synthesis and structure-activity relationships (SAR) of novel pyrrole based analogues of N6022 focusing on removal of cytochrome P450 inhibition activities. We identified potent and novel GSNOR inhibitors having reduced CYP inhibition activities and demonstrated efficacy in a mouse ovalbumin (OVA) model of asthma.


Subject(s)
Aldehyde Oxidoreductases/antagonists & inhibitors , Benzamides/pharmacology , Cytochrome P-450 Enzyme System/metabolism , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , Imidazoles/chemical synthesis , Imidazoles/pharmacology , Pyrroles/pharmacology , Animals , Asthma/drug therapy , Asthma/enzymology , Benzamides/chemistry , Benzamides/toxicity , Cytochrome P-450 Enzyme Inhibitors , Disease Models, Animal , Dose-Response Relationship, Drug , Drug Administration Schedule , Drug Design , Drug Evaluation, Preclinical , Enzyme Inhibitors/pharmacokinetics , Enzyme Inhibitors/toxicity , Humans , Imidazoles/pharmacokinetics , Imidazoles/toxicity , Lung/pathology , Lung/physiopathology , Mice , Molecular Structure , Molecular Targeted Therapy , No-Observed-Adverse-Effect Level , Pyrroles/chemistry , Pyrroles/toxicity , Receptors, Opioid, delta/metabolism , S-Nitrosoglutathione/metabolism , Structure-Activity Relationship
20.
Bioorg Med Chem Lett ; 21(12): 3671-5, 2011 Jun 15.
Article in English | MEDLINE | ID: mdl-21570838

ABSTRACT

S-Nitrosoglutathione reductase (GSNOR) is a member of the alcohol dehydrogenase family (ADH) that regulates the levels of S-nitrosothiols (SNOs) through catabolism of S-nitrosoglutathione (GSNO). GSNO and SNOs are implicated in the pathogenesis of many diseases including those in respiratory, cardiovascular, and gastrointestinal systems. The pyrrole based N6022 was recently identified as a potent, selective, reversible, and efficacious GSNOR inhibitor which is currently undergoing clinical development. We describe here the synthesis and structure-activity relationships (SAR) of novel pyrrole based analogues of N6022 focusing on scaffold modification and propionic acid replacement. We identified equally potent and novel GSNOR inhibitors having pyrrole regioisomers as scaffolds using a structure based approach.


Subject(s)
Aldehyde Oxidoreductases/antagonists & inhibitors , Benzamides/chemistry , Benzamides/pharmacology , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Propionates/chemistry , Propionates/pharmacology , Pyrroles/chemistry , Pyrroles/pharmacology , Benzamides/chemical synthesis , Enzyme Activation/drug effects , Enzyme Inhibitors/chemical synthesis , Inhibitory Concentration 50 , Molecular Structure , Propionates/chemical synthesis , Pyrroles/chemical synthesis , Stereoisomerism , Structure-Activity Relationship
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