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1.
Sci Rep ; 14(1): 1794, 2024 01 20.
Article in English | MEDLINE | ID: mdl-38245568

ABSTRACT

Plasma metabolomics profiling is an emerging methodology to identify metabolic pathways underlying cardiovascular health (CVH). The objective of this study was to define metabolomic profiles underlying CVH in a cohort of Black adults, a population that is understudied but suffers from disparate levels of CVD risk factors. The Morehouse-Emory Cardiovascular (MECA) Center for Health Equity study cohort consisted of 375 Black adults (age 53 ± 10, 39% male) without known CVD. CVH was determined by the AHA Life's Simple 7 (LS7) score, calculated from measured blood pressure, body mass index (BMI), fasting blood glucose and total cholesterol, and self-reported physical activity, diet, and smoking. Plasma metabolites were assessed using untargeted high-resolution metabolomics profiling. A metabolome wide association study (MWAS) identified metabolites associated with LS7 score after adjusting for age and sex. Using Mummichog software, metabolic pathways that were significantly enriched in metabolites associated with LS7 score were identified. Metabolites representative of these pathways were compared across clinical domains of LS7 score and then developed into a metabolomics risk score for prediction of CVH. We identified novel metabolomic signatures and pathways associated with CVH in a cohort of Black adults without known CVD. Representative and highly prevalent metabolites from these pathways included glutamine, glutamate, urate, tyrosine and alanine, the concentrations of which varied with BMI, fasting glucose, and blood pressure levels. When assessed in conjunction, these metabolites were independent predictors of CVH. One SD increase in the novel metabolomics risk score was associated with a 0.88 higher LS7 score, which translates to a 10.4% lower incident CVD risk. We identified novel metabolomic signatures of ideal CVH in a cohort of Black Americans, showing that a core group of metabolites central to nitrogen balance, bioenergetics, gluconeogenesis, and nucleotide synthesis were associated with CVH in this population.


Subject(s)
Cardiovascular Diseases , Adult , Humans , Male , United States , Middle Aged , Female , Cardiovascular Diseases/epidemiology , Risk Factors , Blood Pressure/physiology , Smoking , Diet , Health Status
2.
Curr Cardiol Rep ; 26(2): 51-60, 2024 02.
Article in English | MEDLINE | ID: mdl-38206553

ABSTRACT

PURPOSE OF REVIEW: MicroRNAs (miRNAs)-short, non-coding RNAs-play important roles in almost all aspects of cardiovascular biology, and changes in intracellular miRNA expression are indicative of cardiovascular disease development and progression. Extracellular miRNAs, which are easily measured in blood and can be reflective of changes in intracellular miRNA levels, have emerged as potential non-invasive biomarkers for disease. This review summarizes current knowledge regarding miRNAs as biomarkers for assessing cardiovascular disease risk and prognosis. RECENT FINDINGS: Numerous studies over the last 10-15 years have identified associations between extracellular miRNA profiles and cardiovascular disease, supporting the potential use of extracellular miRNAs as biomarkers for risk stratification. However, clinical application of extracellular miRNA profiles has been hampered by poor reproducibility and inter-study variability that is due largely to methodological differences between studies. While recent studies indicate that circulating extracellular miRNAs are promising biomarkers for cardiovascular disease, evidence for clinical implementation is lacking. This highlights the need for larger, well-designed studies that use standardized methods for sample preparation, miRNA isolation, quantification, and normalization.


Subject(s)
Cardiovascular Diseases , MicroRNAs , Humans , MicroRNAs/genetics , MicroRNAs/metabolism , Cardiovascular Diseases/genetics , Cardiovascular Diseases/metabolism , Reproducibility of Results , Prognosis , Biomarkers
4.
JACC Basic Transl Sci ; 8(3): 298-300, 2023 Mar.
Article in English | MEDLINE | ID: mdl-37034283
5.
Ann Epidemiol ; 65: 120.e1-120.e10, 2022 01.
Article in English | MEDLINE | ID: mdl-33285258

ABSTRACT

PURPOSE: Neighborhood environment is increasingly recognized as an important determinant of cardiovascular health (CVH) among Black adults. Most research to date has focused on negative aspects of the neighborhood environment, with little attention being paid to the specific positive features, in particular the social environment, that promote cardiovascular resilience among Black adults.We examined whether better neighborhood physical and social characteristics are associated with ideal CVH among Black adults, as measured by Life's Simple 7 (LS7) scores. METHODS: We recruited 392 Black adults (age 53 ± 10 years, 39% men) without known CV disease living in Atlanta, GA. Seven neighborhood domains were assessed via questionnaire: asthetic quality, walking environment, safety, food access, social cohesion, activity with neighbors, and violence. CVH was determined by LS7 scores calculated from measured blood pressure; glucose; cholesterol; body mass index (BMI); and self-reported exercise, diet, and smoking, and categorized into poor (0-8), intermediate (9-10), and ideal (11-14). Multinomial logistic regression was used to examine the association between neighborhood characteristics and the odds of intermediate/ideal CVH categories compared with poor CVH after adjustment for age, gender, household income, education, marital status, and employment status. RESULTS: Better scores in the neighborhood domains of social cohesion and activity with neighbors were significantly associated with higher adjusted odds of ideal LS7 scores (OR 2.02, 95% CI [1.36-3.01] and 1.71 [1.20-2.45] per 1 standard deviation [SD] increase in respective scores). These associations were stronger for both social cohesion (OR 2.61, 95% CI [1.48-4.61] vs. 1.40 [0.82-2.40]) and activity with neighbors (OR 1.82, 95% CI [1.15-2.86] vs. 1.53 [0.84-2.78]) in Black women than men. Specifically, better scores in social cohesion were associated with higher odds of ideal CVH in exercise (OR 1.73 [1.16-2.59]), diet (OR 1.90 [1.11-3.26]), and BMI (OR 1.52 [1.09-2.09]); better scores in activity with neighbors were also similarly associated with higher odds of ideal CVH in exercise (OR 1.48 [1.00-2.19]), diet (OR 2.15 [1.23-3.77]), and BMI (OR 1.45 [1.07-1.98]; per 1 SD in respective scores). CONCLUSIONS: More desirable neighborhood characteristics, particularly social cohesion and activity with neighbors, were associated with better CVH among Black adults.


Subject(s)
Cardiovascular Diseases , Health Equity , Adenosine/analogs & derivatives , Adult , Blood Pressure , Body Mass Index , Cardiovascular Diseases/epidemiology , Female , Health Status , Humans , Male , Middle Aged , Neighborhood Characteristics , Risk Factors
6.
Vasc Med ; 27(1): 13-20, 2022 02.
Article in English | MEDLINE | ID: mdl-34549642

ABSTRACT

Arterial stiffness is a precursor for the development of hypertension and premature cardiovascular disease (CVD). Physical activity has been associated with lower arterial stiffness among largely White populations, but the types of activity required and whether these findings apply to Black adults remain unknown. We examined whether physical activity levels were associated with arterial stiffness among Black adults in two independent cohorts. In the Morehouse-Emory Cardiovascular (MECA) Center for Health Equity, 378 Black adults (age 52.8 ± 10.3, 39.7% male) without known CVD living in Atlanta, GA were recruited. Arterial stiffness was measured as pulse wave velocity (PWV). Total and domain-specific physical activity were assessed by self-report. Multiple linear regression models were used to investigate differences across physical activity levels after adjusting for age, sex, CVD risk factors, and socioeconomic status. Findings were validated in an independent cohort of Black adults (n = 55, age 50.4 ± 9.2, 23.6% male). After adjustment for covariates, lower arterial stiffness was associated with higher self-reported levels of sport/exercise (6.92 ± 1.13 vs 7.75 ± 1.14, p < 0.001, highest vs lowest quartile) and home/life activities (7.34 ± 1.24 vs 7.73 ± 1.07, p = 0.04, highest vs lowest quartile), but not work, active living, or the overall physical activity scores. These findings were replicated in the independent cohort where higher levels of sport/exercise remained associated with lower arterial stiffness (6.66 ± 0.57 vs 8.21 ± 0.66, p < 0.001, highest vs lowest quartile). Higher levels of sport/exercise and home/life-related physical activities (in comparison to occupational physical activity) are associated with lower arterial stiffness in Black adults.


Subject(s)
Cardiovascular Diseases , Hypertension , Vascular Stiffness , Adult , Cardiovascular Diseases/diagnosis , Cardiovascular Diseases/epidemiology , Exercise , Female , Humans , Hypertension/diagnosis , Hypertension/epidemiology , Male , Pulse Wave Analysis , Risk Factors
7.
Open Forum Infect Dis ; 9(12): ofac641, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36601554

ABSTRACT

Background: The coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has demonstrated the need to share data and biospecimens broadly to optimize clinical outcomes for US military Veterans. Methods: In response, the Veterans Health Administration established VA SHIELD (Science and Health Initiative to Combat Infectious and Emerging Life-threatening Diseases), a comprehensive biorepository of specimens and clinical data from affected Veterans to advance research and public health surveillance and to improve diagnostic and therapeutic capabilities. Results: VA SHIELD now comprises 12 sites collecting de-identified biospecimens from US Veterans affected by SARS-CoV-2. In addition, 2 biorepository sites, a data processing center, and a coordinating center have been established under the direction of the Veterans Affairs Office of Research and Development. Phase 1 of VA SHIELD comprises 34 157 samples. Of these, 83.8% had positive tests for SARS-CoV-2, with the remainder serving as contemporaneous controls. The samples include nasopharyngeal swabs (57.9%), plasma (27.9%), and sera (12.5%). The associated clinical and demographic information available permits the evaluation of biological data in the context of patient demographics, clinical experience and management, vaccinations, and comorbidities. Conclusions: VA SHIELD is representative of US national diversity with a significant potential to impact national healthcare. VA SHIELD will support future projects designed to better understand SARS-CoV-2 and other emergent healthcare crises. To the extent possible, VA SHIELD will facilitate the discovery of diagnostics and therapeutics intended to diminish COVID-19 morbidity and mortality and to reduce the impact of new emerging threats to the health of US Veterans and populations worldwide.

8.
Circ Cardiovasc Qual Outcomes ; 14(9): e007904, 2021 09.
Article in English | MEDLINE | ID: mdl-34380328

ABSTRACT

BACKGROUND: Early trauma (general, emotional, physical, and sexual abuse before age 18 years) has been associated with both cardiovascular disease risk and lifestyle-related risk factors for cardiovascular disease, including smoking, obesity, and physical inactivity. Despite higher prevalence, the association between early trauma and cardiovascular health (CVH) has been understudied in Black Americans, especially those from low-income backgrounds, who may be doubly vulnerable. Therefore, we investigated the association between early trauma and CVH, particularly among low-income Black Americans. METHODS: We recruited 457 Black adults (age 53±10, 38% male) without known cardiovascular disease from the Atlanta, GA, metropolitan area using personalized, community-based recruitment methods. The Early Trauma Inventory was administered to assess overall early traumatic life experiences which include physical, sexual, emotional abuse, and general trauma. Our primary outcome was the American Heart Association Life's Simple 7, which is a set of 7 CVH metrics, including 4 lifestyle-related factors (smoking, body mass index, physical activity, and diet) and three physiologically measured health factors (blood pressure, total blood cholesterol, and blood glucose). We used linear regression models adjusting for age, sex, socioeconomic status, and depression to test the association between early trauma and CVH and tested the early trauma by household income (<$50 000) interaction. RESULTS: Higher levels of early trauma were associated with lower Life's Simple 7 scores (ß, -0.05 [95% CI, -0.09 to -0.01], P=0.02, per 1 unit increase in the Early Trauma Inventory score) among lower, but not higher, income Black participants (P value for interaction=0.04). Subtypes of early trauma linked to Life's Simple 7 were general trauma, emotional abuse, and sexual abuse. Exploratory analyses demonstrated that early trauma was only associated with the body mass index and smoking components of Life's Simple 7. CONCLUSIONS: Early trauma, including general trauma, emotional abuse, and sexual abuse, may be associated with worse CVH among low-, but not higher-income Black adults.


Subject(s)
Cardiovascular Diseases , Health Equity , Adolescent , Adult , Black or African American , American Heart Association , Blood Glucose , Blood Pressure , Body Mass Index , Cardiovascular Diseases/diagnosis , Cardiovascular Diseases/epidemiology , Exercise , Female , Humans , Male , Middle Aged , Risk Factors , United States/epidemiology
9.
Crit Care Explor ; 2(12): e0288, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33294847

ABSTRACT

OBJECTIVES: Coronavirus disease 2019 is associated with high mortality rates and multiple organ damage. There is increasing evidence that these patients are at risk for various cardiovascular insults; however, there are currently no guidelines for the diagnosis and management of such cardiovascular complications in patients with coronavirus disease 2019. We share data and recommendations from a multidisciplinary team to highlight our institution's clinical experiences and guidelines for managing cardiovascular complications of coronavirus disease 2019. DESIGN SETTING AND PATIENTS: This was a retrospective cohort study of patients admitted to one of six ICUs dedicated to the care of patients with coronavirus disease 2019 located in three hospitals within one academic medical center in Atlanta, Georgia. MEASUREMENTS/INTERVENTIONS: Chart review was conducted for sociodemographic, laboratory, and clinical data. Rates of specific cardiovascular complications were assessed, and data were analyzed using a chi-square or Wilcoxon rank-sum test for categorical and continuous variables. Additionally, certain cases are presented to demonstrate the sub committee's recommendations. MAIN RESULTS: Two-hundred eighty-eight patients were admitted to the ICU with coronavirus disease 2019. Of these, 86 died (29.9%), 242 (84.03%) had troponin elevation, 70 (24.31%) had dysrhythmias, four (1.39%) had ST-elevation myocardial infarction, eight (2.78%) developed cor pulmonale, and 190 (65.97%) with shock. There was increased mortality risk in patients with greater degrees of troponin elevation (p < 0.001) and with the development of arrhythmias (p < 0.001), cor pulmonale (p < 0.001), and shock (p < 0.001). CONCLUSIONS: While there are guidelines for the diagnosis and management of pulmonary complications of coronavirus disease 2019, there needs to be more information regarding the management of cardiovascular complications as well. These recommendations garnered from the coronavirus disease 2019 cardiology subcommittee from our institution will add to the existing knowledge of these potential cardiovascular insults as well as highlight suggestions for the diagnosis and management of the range of cardiovascular complications of coronavirus disease 2019. Additionally, with the spread of coronavirus disease 2019, our case-based recommendations provide a bedside resource for providers newly caring for patients with coronavirus disease 2019.

11.
Circ Cardiovasc Qual Outcomes ; 13(10): e006638, 2020 10.
Article in English | MEDLINE | ID: mdl-33023334

ABSTRACT

BACKGROUND: Despite well-documented cardiovascular disparities between racial groups, within-race determinants of cardiovascular health among Black adults remain understudied. Factors promoting cardiovascular resilience among Black adults in particular warrant further investigation. Our objective was to examine whether individual psychosocial resilience and neighborhood-level cardiovascular resilience were associated with better cardiovascular health in Black adults, measured utilizing Life's Simple 7 (LS7) scores. METHODS: We assessed LS7 scores in 389 Black adults (mean age, 53±10 years; 39% men) living in Atlanta, Georgia. A composite score of individual psychosocial resilience was created by assessing environmental mastery, purpose in life, optimism, resilient coping, and depressive symptoms. Neighborhood-level cardiovascular resilience was separately determined by the census tract-level rates of cardiovascular mortality/morbidity events. Generalized linear mixed regression models were used to examine the association between individual psychosocial resilience, neighborhood cardiovascular resilience, and LS7 scores. RESULTS: Higher individual psychosocial resilience was significantly associated with higher LS7 (ß=0.38 [0.16-0.59] per 1 SD) after adjustment for sociodemographic factors. Similarly, higher neighborhood-level cardiovascular resilience was significantly associated with higher LS7 (ß=0.23 [0.02-0.45] per 1 SD). When jointly examined, high individual psychosocial resilience (>median) was independently associated with higher LS7 (ß=0.73 [0.31-1.17]), whereas living in high-resilience neighborhoods (>median) was not. The largest difference in LS7 score was between those with high and low psychosocial resilience living in low-resilience neighborhoods (8.38 [7.90-8.86] versus 7.42 [7.04-7.79]). CONCLUSIONS: Individual psychosocial resilience in Black adults is associated with better cardiovascular health.


Subject(s)
Black or African American/psychology , Cardiovascular Diseases/prevention & control , Health Equity , Health Status Disparities , Healthcare Disparities/ethnology , Healthy Lifestyle , Residence Characteristics , Resilience, Psychological , Risk Reduction Behavior , Social Determinants of Health , Adult , Cardiovascular Diseases/diagnosis , Cardiovascular Diseases/ethnology , Cardiovascular Diseases/psychology , Cross-Sectional Studies , Female , Georgia/epidemiology , Humans , Male , Middle Aged , Race Factors , Risk Assessment , Risk Factors
12.
J Am Heart Assoc ; 9(9): e015247, 2020 05 05.
Article in English | MEDLINE | ID: mdl-32340530

ABSTRACT

Background Cardiovascular disease incidence, prevalence, morbidity, and mortality have declined in the past several decades; however, disparities persist among subsets of the population. Notably, blacks have not experienced the same improvements on the whole as whites. Furthermore, frequent reports of relatively poorer health statistics among the black population have led to a broad assumption that black race reliably predicts relatively poorer health outcomes. However, substantial intraethnic and intraracial heterogeneity exists; moreover, individuals with similar risk factors and environmental exposures are often known to experience vastly different cardiovascular health outcomes. Thus, some individuals have good outcomes even in the presence of cardiovascular risk factors, a concept known as resilience. Methods and Results The MECA (Morehouse-Emory Center for Health Equity) Study was designed to investigate the multilevel exposures that contribute to "resilience" in the face of risk for poor cardiovascular health among blacks in the greater Atlanta, GA, metropolitan area. We used census tract data to determine "at-risk" and "resilient" neighborhoods with high or low prevalence of cardiovascular morbidity and mortality, based on cardiovascular death, hospitalization, and emergency department visits for blacks. More than 1400 individuals from these census tracts assented to demographic, health, and psychosocial questionnaires administered through telephone surveys. Afterwards, ≈500 individuals were recruited to enroll in a clinical study, where risk biomarkers, such as oxidative stress, and inflammatory markers, endothelial progenitor cells, metabolomic and microRNA profiles, and subclinical vascular dysfunction were measured. In addition, comprehensive behavioral questionnaires were collected and ideal cardiovascular health metrics were assessed using the American Heart Association's Life Simple 7 measure. Last, 150 individuals with low Life Simple 7 were recruited and randomized to a behavioral mobile health (eHealth) plus health coach or eHealth only intervention and followed up for improvement. Conclusions The MECA Study is investigating socioenvironmental and individual behavioral measures that promote resilience to cardiovascular disease in blacks by assessing biological, functional, and molecular mechanisms. REGISTRATION URL: https://www.clini​caltr​ials.gov. Unique identifier: NCT03308812.


Subject(s)
Black or African American , Cardiovascular Diseases/ethnology , Health Status Disparities , Social Determinants of Health/ethnology , Urban Health/ethnology , Adult , Black or African American/psychology , Aged , Cardiovascular Diseases/mortality , Cardiovascular Diseases/prevention & control , Cardiovascular Diseases/psychology , Female , Georgia/epidemiology , Health Behavior/ethnology , Health Knowledge, Attitudes, Practice/ethnology , Heart Disease Risk Factors , Humans , Life Style/ethnology , Male , Middle Aged , Prevalence , Preventive Health Services , Prognosis , Race Factors , Research Design , Risk Assessment , Socioeconomic Factors
14.
Theranostics ; 7(3): 634-646, 2017.
Article in English | MEDLINE | ID: mdl-28255356

ABSTRACT

MicroRNAs (miRNAs) are small, noncoding RNAs that post-transcriptionally regulate gene expression and are recognized for their roles both as modulators of disease progression and as biomarkers of disease activity, including neurological diseases, cancer, and cardiovascular disease (CVD). Commonly, miRNA abundance is assessed using quantitative real-time PCR (qRT-PCR), however, qRT-PCR for miRNA can be labor intensive, time consuming, and may lack specificity for detection of mature versus precursor forms of miRNA. Here, we describe a novel double molecular beacon approach to miRNA assessment that can distinguish and quantify mature versus precursor forms of miRNA in a single assay, an essential feature for use of miRNAs as biomarkers for disease. Using this approach, we found that molecular beacons with DNA or combined locked nucleic acid (LNA)-DNA backbones can detect mature and precursor miRNAs (pre-miRNAs) of low (< 1 nM) abundance in vitro. The double molecular beacon assay was accurate in assessing miRNA abundance in a sample containing a mixed population of mature and precursor miRNAs. In contrast, qRT-PCR and the single molecular beacon assay overestimated miRNA abundance. Additionally, the double molecular beacon assay was less labor intensive than traditional qRT-PCR and had 10-25% increased specificity. Our data suggest that the double molecular beacon-based approach is more precise and specific than previous methods, and has the promise of being the standard for assessing miRNA levels in biological samples.


Subject(s)
MicroRNAs/analysis , Molecular Diagnostic Techniques/methods , Sensitivity and Specificity
15.
PLoS One ; 11(10): e0163582, 2016.
Article in English | MEDLINE | ID: mdl-27760197

ABSTRACT

BACKGROUND: Red blood cell (RBC) transfusions are a common, life-saving therapy for many patients, but they have also been associated with poor clinical outcomes. We identified unusual, pleomorphic structures in human RBC transfusion units by negative-stain electron microscopy that appeared identical to those previously reported to be bacteria in healthy human blood samples. The presence of viable, replicating bacteria in stored blood could explain poor outcomes in transfusion recipients and have major implications for transfusion medicine. Here, we investigated the possibility that these structures were bacteria. RESULTS: Flow cytometry, miRNA analysis, protein analysis, and additional electron microscopy studies strongly indicated that the pleomorphic structures in the supernatant of stored RBCs were RBC-derived microparticles (RMPs). Bacterial 16S rDNA PCR amplified from these samples were sequenced and was found to be highly similar to species that are known to commonly contaminate laboratory reagents. CONCLUSIONS: These studies suggest that pleomorphic structures identified in human blood are RMPs and not bacteria, and they provide an example in which laboratory contaminants may can mislead investigators.


Subject(s)
Bacteria/cytology , Cell-Derived Microparticles , Erythrocytes/cytology , Blood Proteins/metabolism , Cell Shape , Cell Size , Cell-Derived Microparticles/microbiology , DNA, Bacterial/metabolism , Erythrocytes/microbiology , Erythrocytes/ultrastructure , Humans , MicroRNAs/metabolism , Microscopy, Electron , Time Factors
16.
Sci Rep ; 6: 32651, 2016 09 13.
Article in English | MEDLINE | ID: mdl-27623086

ABSTRACT

Extracellular miRNAs are detectable in biofluids and represent a novel class of disease biomarker. Although many studies have utilized archived plasma for miRNA biomarker discovery, the effects of processing and storage have not been rigorously studied. Previous reports have suggested plasma samples are commonly contaminated by platelets, significantly confounding the measurement of extracellular miRNA, which was thought to be easily addressed by additional post-thaw plasma processing. In a case-control study of archived plasma, we noted a significant correlation between miRNA levels and platelet counts despite post-thaw processing. We thus examined the effects of a single freeze/thaw cycle on microparticles (MPs) and miRNA levels, and show that a single freeze/thaw cycle of plasma dramatically increases the number of platelet-derived MPs, contaminates the extracellular miRNA pool, and profoundly affects the levels of miRNAs detected. The measurement of extracellular miRNAs in archived samples is critically dependent on the removal of residual platelets prior to freezing plasma samples. Many previous clinical studies of extracellular miRNA in archived plasma should be interpreted with caution and future studies should avoid the effects of platelet contamination.


Subject(s)
Blood Platelets , MicroRNAs/blood , Specimen Handling/methods , Cell-Derived Microparticles/genetics , Flow Cytometry , Freezing , Humans , MicroRNAs/isolation & purification , Platelet Count
18.
Am J Respir Cell Mol Biol ; 54(1): 136-46, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26098770

ABSTRACT

Endothelin-1 (ET-1) plays a critical role in endothelial dysfunction and contributes to the pathogenesis of pulmonary hypertension (PH). We hypothesized that peroxisome proliferator-activated receptor γ (PPARγ) stimulates microRNAs that inhibit ET-1 and pulmonary artery endothelial cell (PAEC) proliferation. The objective of this study was to clarify molecular mechanisms by which PPARγ regulates ET-1 expression in vitro and in vivo. In PAECs isolated from patients with pulmonary arterial hypertension, microRNA (miR)-98 expression was reduced, and ET-1 protein levels and proliferation were increased. Similarly, hypoxia reduced miR-98 and increased ET-1 levels and PAEC proliferation in vitro. In vivo, hypoxia reduced miR-98 expression and increased ET-1 and proliferating cell nuclear antigen (PCNA) levels in mouse lung, derangements that were aggravated by treatment with the vascular endothelial growth factor receptor antagonist Sugen5416. Reporter assays confirmed that miR-98 binds directly to the ET-1 3'-untranslated region. Compared with littermate control mice, miR-98 levels were reduced and ET-1 and PCNA expression were increased in lungs from endothelial-targeted PPARγ knockout mice, whereas miR-98 levels were increased and ET-1 and PCNA expression was reduced in lungs from endothelial-targeted PPARγ-overexpression mice. Gain or loss of PPARγ function in PAECs in vitro confirmed that alterations in PPARγ were sufficient to regulate miR-98, ET-1, and PCNA expression. Finally, PPARγ activation with rosiglitazone regimens that attenuated hypoxia-induced PH in vivo and human PAEC proliferation in vitro restored miR-98 levels. The results of this study show that PPARγ regulates miR-98 to modulate ET-1 expression and PAEC proliferation. These results further clarify molecular mechanisms by which PPARγ participates in PH pathogenesis and therapy.


Subject(s)
Endothelial Cells/metabolism , Endothelin-1/metabolism , Hypertension, Pulmonary/metabolism , Hypoxia/metabolism , MicroRNAs/metabolism , PPAR gamma/metabolism , Pulmonary Artery/metabolism , Signal Transduction , 3' Untranslated Regions , Animals , Binding Sites , Cell Proliferation , Cells, Cultured , Endothelial Cells/drug effects , Endothelial Cells/pathology , Endothelin-1/genetics , Gene Expression Regulation , Humans , Hypertension, Pulmonary/chemically induced , Hypertension, Pulmonary/drug therapy , Hypertension, Pulmonary/genetics , Hypertension, Pulmonary/pathology , Hypoxia/complications , Hypoxia/genetics , Hypoxia/pathology , Indoles , Male , Mice, Inbred C57BL , Mice, Knockout , MicroRNAs/genetics , PPAR gamma/agonists , PPAR gamma/deficiency , PPAR gamma/genetics , Pulmonary Artery/drug effects , Pulmonary Artery/pathology , Pyrroles , RNA Interference , Rosiglitazone , Signal Transduction/drug effects , Thiazolidinediones/pharmacology , Transfection , Vascular Remodeling
19.
MethodsX ; 2: 360-7, 2015.
Article in English | MEDLINE | ID: mdl-26543819

ABSTRACT

Extracellular, membrane vesicles (microvesicles, exosomes) are secreted by cells and may serve as mediators of intercellular communication. Methods for detecting them by flow cytometry have included the use of agents that fluorescently stain vesicle membrane, or fluorescent antibodies that target specific cell-of-origin antigens. However, these methods may falsely detect cell debris or require prior cell-of-origin knowledge. Here, we demonstrate the suitability of calcein AM for detection of intact extracellular vesicles (EVs) by flow cytometry.•Calcein AM is non-fluorescent until it passively enters EVs, after which it is activated and becomes fluorescent and EV-impermeant.•Permeabilized/lysed EVs label positive with antibodies and lipophilic membrane stain, whereas no labeling was observed with calcein. In contrast to methods that use antibodies or membrane stains, calcein AM allows for the differentiation between intact EVs and debris.•Calcein AM can be used for detection of intact EVs from numerous cell types.

20.
PLoS One ; 10(7): e0133391, 2015.
Article in English | MEDLINE | ID: mdl-26208095

ABSTRACT

Pulmonary hypertension (PH) is a progressive and often fatal disorder whose pathogenesis involves pulmonary artery smooth muscle cell (PASMC) proliferation. Although modern PH therapies have significantly improved survival, continued progress rests on the discovery of novel therapies and molecular targets. MicroRNA (miR)-21 has emerged as an important non-coding RNA that contributes to PH pathogenesis by enhancing vascular cell proliferation, however little is known about available therapies that modulate its expression. We previously demonstrated that peroxisome proliferator-activated receptor gamma (PPARγ) agonists attenuated hypoxia-induced HPASMC proliferation, vascular remodeling and PH through pleiotropic actions on multiple targets, including transforming growth factor (TGF)-ß1 and phosphatase and tensin homolog deleted on chromosome 10 (PTEN). PTEN is a validated target of miR-21. We therefore hypothesized that antiproliferative effects conferred by PPARγ activation are mediated through inhibition of hypoxia-induced miR-21 expression. Human PASMC monolayers were exposed to hypoxia then treated with the PPARγ agonist, rosiglitazone (RSG,10 µM), or in parallel, C57Bl/6J mice were exposed to hypoxia then treated with RSG. RSG attenuated hypoxic increases in miR-21 expression in vitro and in vivo and abrogated reductions in PTEN and PASMC proliferation. Antiproliferative effects of RSG were lost following siRNA-mediated PTEN depletion. Furthermore, miR-21 mimic decreased PTEN and stimulated PASMC proliferation, whereas miR-21 inhibition increased PTEN and attenuated hypoxia-induced HPASMC proliferation. Collectively, these results demonstrate that PPARγ ligands regulate proliferative responses to hypoxia by preventing hypoxic increases in miR-21 and reductions in PTEN. These findings further clarify molecular mechanisms that support targeting PPARγ to attenuate pathogenic derangements in PH.


Subject(s)
Hypoxia/metabolism , Ligands , MicroRNAs/genetics , Myocytes, Smooth Muscle/drug effects , Myocytes, Smooth Muscle/metabolism , PPAR gamma/metabolism , Pulmonary Artery/cytology , Animals , Cell Proliferation , Gene Expression , Gene Expression Regulation/drug effects , Humans , Male , Mice , PTEN Phosphohydrolase/genetics , PTEN Phosphohydrolase/metabolism , Rosiglitazone , Thiazolidinediones/pharmacology , Transforming Growth Factor beta1/metabolism
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