440 research outputs found
Recommended from our members
The adaptor protein CRK is a pro-apoptotic transducer of endoplasmic reticulum stress.
Excessive demands on the protein-folding capacity of the endoplasmic reticulum (ER) cause irremediable ER stress and contribute to cell loss in a number of cell degenerative diseases, including type 2 diabetes and neurodegeneration. The signals communicating catastrophic ER damage to the mitochondrial apoptotic machinery remain poorly understood. We used a biochemical approach to purify a cytosolic activity induced by ER stress that causes release of cytochrome c from isolated mitochondria. We discovered that the principal component of the purified pro-apoptotic activity is the proto-oncoprotein CRK (CT10-regulated kinase), an adaptor protein with no known catalytic activity. Crk(-/-) cells are strongly resistant to ER-stress-induced apoptosis. Moreover, CRK is cleaved in response to ER stress to generate an amino-terminal M(r)~14K fragment with greatly enhanced cytotoxic potential. We identified a putative BH3 (BCL2 homology 3) domain within this N-terminal CRK fragment, which sensitizes isolated mitochondria to cytochrome c release and when mutated significantly reduces the apoptotic activity of CRK in vivo. Together these results identify CRK as a pro-apoptotic protein that signals irremediable ER stress to the mitochondrial execution machinery
Epidemiology, genetics, and subtyping of preserved ratio impaired spirometry (PRISm) in COPDGene.
BackgroundPreserved Ratio Impaired Spirometry (PRISm), defined as a reduced FEV1 in the setting of a preserved FEV1/FVC ratio, is highly prevalent and is associated with increased respiratory symptoms, systemic inflammation, and mortality. Studies investigating quantitative chest tomographic features, genetic associations, and subtypes in PRISm subjects have not been reported.MethodsData from current and former smokers enrolled in COPDGene (n = 10,192), an observational, cross-sectional study which recruited subjects aged 45-80 with ≥10 pack years of smoking, were analyzed. To identify epidemiological and radiographic predictors of PRISm, we performed univariate and multivariate analyses comparing PRISm subjects both to control subjects with normal spirometry and to subjects with COPD. To investigate common genetic predictors of PRISm, we performed a genome-wide association study (GWAS). To explore potential subgroups within PRISm, we performed unsupervised k-means clustering.ResultsThe prevalence of PRISm in COPDGene is 12.3%. Increased dyspnea, reduced 6-minute walk distance, increased percent emphysema and decreased total lung capacity, as well as increased segmental bronchial wall area percentage were significant predictors (p-value <0.05) of PRISm status when compared to control subjects in multivariate models. Although no common genetic variants were identified on GWAS testing, a significant association with Klinefelter's syndrome (47XXY) was observed (p-value < 0.001). Subgroups identified through k-means clustering include a putative "COPD-subtype", "Restrictive-subtype", and a highly symptomatic "Metabolic-subtype".ConclusionsPRISm subjects are clinically and genetically heterogeneous. Future investigations into the pathophysiological mechanisms behind and potential treatment options for subgroups within PRISm are warranted.Trial registrationClinicaltrials.gov Identifier: NCT000608764
Realizing Health Reform's Potential: Factors Affecting Health Insurance Enrollment Through the State Marketplace - Observations on the ACA's Third Open Enrollment Period
Nearly 12.7 million individuals signed up for coverage in the Affordable Care Act's (ACA) health insurance marketplaces during the third open enrollment period, and by the end of March there were 11.1 million consumers with active coverage. States that operate their own marketplaces posted a year-to-year enrollment gain of 8.8 percent. To maintain membership and attract new consumers, the statebased marketplaces must sponsor enrollment assistance programs and conduct consumer outreach. These marketplaces relied heavily on such efforts during the third enrollment period, despite declining funding. Goal: To learn which outreach strategies, assistance programs, and other factors marketplace officials viewed as having exerted the greatest influence on enrollment. Methods: Survey of officialsrepresenting each of the 17 state-based marketplaces (15 responses). Key findings andconclusions: The cost of coverage and low health insurance literacy pose significantbarriers to enrollment for many consumers. Marketplaces sought to overcome themby encouraging consumers to obtain in-person enrollment assistance from ACAcreatedassistance programs and from insurance brokers, and by partnering with community organizations for outreach activities. Many marketplaces also enhanced their web portals to make them easier to navigate and to give consumers better tools with which to evaluate their coverage options
Nine Months to Life: A Discussion of Legal and Ethical Implications for Pregnant Women Who Use Illicit Substances
Evaluation of an Online Platform for Multiple Sclerosis Research: Patient Description, Validation of Severity Scale, and Exploration of BMI Effects on Disease Course
Objectives: To assess the potential of an online platform, PatientsLikeMe.com (PLM), for research in multiple sclerosis (MS). An investigation of the role of body mass index (BMI) on MS disease course was conducted to illustrate the utility of the platform. Methods: First, we compared the demographic characteristics of subjects from PLM and from a regional MS center. Second, we validated PLM’s patient-reported outcome measure (MS Rating Scale, MSRS) against standard physician-rated tools. Finally, we analyzed the relation of BMI to the MSRS measure. Results: Compared with 4,039 MS Center patients, the 10,255 PLM members were younger, more educated, and less often male and white. Disease course was more often relapsing remitting, with younger symptom onset and shorter disease duration. Differences were significant because of large sample sizes but small in absolute terms. MSRS scores for 121 MS Center patients revealed acceptable agreement between patient-derived and physician-derived composite scores (weighted kappa = 0.46). The Walking domain showed the highest weighted kappa (0.73) and correlation (rs = 0.86) between patient and physician scores. Additionally, there were good correlations between the patient-reported MSRS composite and walking scores and physician-derived measures: Expanded Disability Status Scale (composite rs = 0.61, walking rs = 0.74), Timed 25 Foot Walk (composite rs = 0.70, walking rs = 0.69), and Ambulation Index (composite rs = 0.81, walking rs = 0.84). Finally, using PLM data, we found a modest correlation between BMI and cross-sectional MSRS (rho = 0.17) and no association between BMI and disease course. Conclusions: The PLM population is comparable to a clinic population, and its patient-reported MSRS is correlated with existing clinical instruments. Thus, this online platform may provide a venue for MS investigations with unique strengths (frequent data collection, large sample sizes). To illustrate its applicability, we assessed the role of BMI in MS disease course but did not find a clinically meaningful role for BMI in this setting
Molecular network analysis of phosphotyrosine and lipid metabolism in hepatic PTP1b deletion mice
Metabolic syndrome describes a set of obesity-related disorders that increase diabetes, cardiovascular, and mortality risk. Studies of liver-specific protein-tyrosine phosphatase 1b (PTP1b) deletion mice (L-PTP1b[superscript −/−]) suggest that hepatic PTP1b inhibition would mitigate metabolic-syndrome through amelioration of hepatic insulin resistance, endoplasmic-reticulum stress, and whole-body lipid metabolism. However, the altered molecular-network states underlying these phenotypes are poorly understood. We used mass spectrometry to quantify protein-phosphotyrosine network changes in L-PTP1b[superscript −/−] mouse livers relative to control mice on normal and high-fat diets. We applied a phosphosite-set-enrichment analysis to identify known and novel pathways exhibiting PTP1b- and diet-dependent phosphotyrosine regulation. Detection of a PTP1b-dependent, but functionally uncharacterized, set of phosphosites on lipid-metabolic proteins motivated global lipidomic analyses that revealed altered polyunsaturated-fatty-acid (PUFA) and triglyceride metabolism in L-PTP1b[superscript −/−] mice. To connect phosphosites and lipid measurements in a unified model, we developed a multivariate-regression framework, which accounts for measurement noise and systematically missing proteomics data. This analysis resulted in quantitative models that predict roles for phosphoproteins involved in oxidation–reduction in altered PUFA and triglyceride metabolism.Pfizer Inc. (grant)National Institutes of Health (U.S.) (grant 5R24DK090963)National Institutes of Health (U.S.) (grant U54-CA112967)National Institutes of Health (U.S.) (grant CA49152 R37)National Institutes of Health (U.S.) (grant R01-DK080756)National Mouse Metabolic Phenotyping Center at UMASS (Grant (U24-DK093000))National Science Foundation (U.S.) (Graduate Research Fellowship
Sexual Minority Stressors and Intimate Partner Violence Among Same-Sex Couples: Commitment as a Resource
Accumulating evidence has been found for the associations from sexual minority stressors to intimate partner violence (IPV) among same-sex couples. Yet key gaps still exist, including the rare utilization of couple dyadic data, the understudied moderating and mediating mechanisms, and the few studies conducted during the transitional period of same-sex marriage legalization. To address these gaps, we used cross-sectional, dyadic data collected from 144 US same-sex couples during the 2014–2015 national campaign for the legalization of same-sex marriage. Guided by the systemic transactional model (STM), we examined associations from sexual minority stressors (including both internalized homophobia and discrimination) to same-sex IPV and tested whether commitment moderated or mediated these associations. Overall, we found evidence supporting the STM: (1) High internalized homophobia and discrimination were related to high prevalence and/or frequency of IPV perpetration; (2) high commitment attenuated positive associations between high discrimination and high prevalence and/or frequency of IPV perpetration; and (3) high internalized homophobia was related to low commitment, which in turn was related to high prevalence and/or frequency of IPV perpetration. Collectively, our study identified commitment as both a moderator and mediator in associations from sexual minority stressors to same-sex IPV. Further, the roles of commitment (i.e., moderator or mediator) depend on whether the focal sexual minority stressors are distal and more intermittent (i.e., heterosexist discrimination) or proximal and more constant (i.e., internalized homophobia)
- …
