Publications by authors named "Roy Kim"

40 Publications

Increased peripheral blood neutrophil activation phenotypes and NETosis in critically ill COVID-19 patients: a case series and review of the literature.

Clin Infect Dis 2021 May 14. Epub 2021 May 14.

Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of California San Diego (UCSD), La Jolla, CA 92093, USA.

Background: Increased inflammation has been well defined in COVID-19, while definitive pathways driving severe forms of this disease remain uncertain. Neutrophils are known to contribute to immunopathology in infections, inflammatory diseases and acute respiratory distress syndrome (ARDS), a primary cause of morbidity and mortality in COVID-19. Changes in neutrophil function in COVID-19 may give insight into disease pathogenesis and identify therapeutic targets.

Methods: Blood was obtained serially from critically ill COVID-19 patients for eleven days. Neutrophil extracellular trap formation (NETosis), oxidative burst, phagocytosis and cytokine levels were assessed. Lung tissue was obtained immediately post-mortem for immunostaining. Pubmed searches for neutrophils, lung and COVID-19 yielded ten peer-reviewed research articles in English.

Results: Elevations in neutrophil-associated cytokines IL-8 and IL-6, and general inflammatory cytokines IP-10, GM-CSF, IL-1b, IL-10 and TNF, were identified both at first measurement and across hospitalization (p<0.0001). COVID neutrophils had exaggerated oxidative burst (p<0.0001), NETosis (p<0.0001) and phagocytosis (p<0.0001) relative to controls. Increased NETosis correlated with leukocytosis and neutrophilia, and neutrophils and NETs were identified within airways and alveoli in lung parenchyma of 40% of SARS-CoV-2 infected lungs available for examination (2 out of 5). While elevations in IL-8 and ANC correlated with disease severity, plasma IL-8 levels alone correlated with death.

Conclusions: Literature to date demonstrates compelling evidence of increased neutrophils in the circulation and lungs of COVID-19 patients. importantly, neutrophil quantity and activation correlates with severity of disease. Similarly, our data shows that circulating neutrophils in COVID-19 exhibit an activated phenotype with enhanced NETosis and oxidative burst.
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http://dx.doi.org/10.1093/cid/ciab437DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8241438PMC
May 2021

Deep Learning Algorithm for Automated Cardiac Murmur Detection via a Digital Stethoscope Platform.

J Am Heart Assoc 2021 May 26;10(9):e019905. Epub 2021 Apr 26.

Division of Cardiology Bluhm Cardiovascular InstituteNorthwestern University Chicago IL.

Background Clinicians vary markedly in their ability to detect murmurs during cardiac auscultation and identify the underlying pathological features. Deep learning approaches have shown promise in medicine by transforming collected data into clinically significant information. The objective of this research is to assess the performance of a deep learning algorithm to detect murmurs and clinically significant valvular heart disease using recordings from a commercial digital stethoscope platform. Methods and Results Using >34 hours of previously acquired and annotated heart sound recordings, we trained a deep neural network to detect murmurs. To test the algorithm, we enrolled 962 patients in a clinical study and collected recordings at the 4 primary auscultation locations. Ground truth was established using patient echocardiograms and annotations by 3 expert cardiologists. Algorithm performance for detecting murmurs has sensitivity and specificity of 76.3% and 91.4%, respectively. By omitting softer murmurs, those with grade 1 intensity, sensitivity increased to 90.0%. Application of the algorithm at the appropriate anatomic auscultation location detected moderate-to-severe or greater aortic stenosis, with sensitivity of 93.2% and specificity of 86.0%, and moderate-to-severe or greater mitral regurgitation, with sensitivity of 66.2% and specificity of 94.6%. Conclusions The deep learning algorithm's ability to detect murmurs and clinically significant aortic stenosis and mitral regurgitation is comparable to expert cardiologists based on the annotated subset of our database. The findings suggest that such algorithms would have utility as front-line clinical support tools to aid clinicians in screening for cardiac murmurs caused by valvular heart disease. Registration URL: https://clinicaltrials.gov; Unique Identifier: NCT03458806.
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http://dx.doi.org/10.1161/JAHA.120.019905DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8200722PMC
May 2021

Safety of a Protective Funnel in Primary Breast Augmentation: A Retrospective Analysis of 380 Multicenter Cases in the United States.

Aesthet Surg J 2021 Apr 17. Epub 2021 Apr 17.

Background: Protective funnels devices are commonly used to deliver implants in primary breast augmentation (BA) yet there is a paucity of evidence-based data describing their safety in the literature.

Objectives: The purpose of the study was to assess the safety of protective funnels in primary BA within the first 30-days postoperatively.

Methods: This multi-center, Level 3 study retrospectively reviewed the surgical records of 380 consecutive patients (760 breasts) who underwent primary BA by nine board-certified plastic surgeons using the iNPLANT Funnel (Proximate Concepts LLC, Allendale, NJ, USA) for implant delivery between November 2019 and December 2020. Data was collected pertaining to demographics, implant information, surgery details, and postoperative complications.

Results: The mean patient age was 33 years and 76% patients had a BMI < 25. Of this cohort, 11.4% were smokers, 0.8% had diabetes, and 83% were ASA class 1. All patients received smooth implants with a median volume of 375cc. A total of 8 (2.1%) complications were reported including: 3 hematomas (0.79%), 1 seroma (0.26%) and 1 superficial infection (0.26%). No patient required explantation. We identified ASA class, BMI, surgery duration, and implant size as potential risk factors.

Conclusions: The data suggest that use of protective funnels, such as the iNPLANT Funnel, in primary BA are a safe option when used according to the manufacturer's IFU. Its use led to a low infection rate (0.26%) and a complication rate (2.1%) consistent with the average reported in the literature (2%-2.5%). 1 Implications for clinical practice are encouraging and future research will include a prospective analysis with a larger case series and potentially a control group.
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http://dx.doi.org/10.1093/asj/sjab198DOI Listing
April 2021

Mediterranean diet adherence and metabolic syndrome in US adolescents.

Int J Food Sci Nutr 2021 Jun 28;72(4):537-547. Epub 2020 Oct 28.

Center for Populations Health Research, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA.

The Mediterranean diet (MD) has been found to lower the risk of heart disease, stroke, and diabetes in adults. Little is known about its acceptance and relationship to cardiovascular risk markers in US adolescents. Using data from the National Health and Nutrition Examination Survey, years 2007-2014, we performed a cross-sectional analysis of adherence to the Mediterranean diet among a representative sample of US adolescents ( = 4223), factors that influence adherence, and whether adherence is associated with cardiometabolic risk factors including metabolic syndrome. MD adherence was calculated using the KIDMED scoring system. We found that overall MD adherence was very low among US adolescents, with Mexican American youths having higher adherence compared to other groups. Higher income was associated with greater adherence. There was low intake of key MD foods including olive oil and finfish. The unadjusted prevalence of metabolic syndrome was 6.6%. MD adherence was not associated with metabolic syndrome.
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http://dx.doi.org/10.1080/09637486.2020.1840533DOI Listing
June 2021

Data-Driven Insights on the Effects of COVID-19 on Public Interest in Medical Aesthetics: Part II (Active Analysis).

Aesthet Surg J 2021 Feb;41(3):NP75-NP82

Department of Plastic and Reconstructive Surgery, Johns Hopkins Hospital, Baltimore, MD.

Background: The COVID-19 pandemic significantly affected financial and psychosocial factors that influence plastic surgery demand.

Objectives: The authors sought to actively assess public interest changes and the reasons underlying these shifts.

Methods: Using Amazons' Mechanical Turk, we crowdsourced public opinions regarding aesthetic interventions from April 30 to May 3, 2020. The survey assessed prior experience with and interest in 6 aesthetic interventions before and during the pandemic and reasons for changing interest. United States residents aged 18 years and over who passed the attention check were included.

Results: We included 704 of 838 total responses. One-half of respondents were female; the median age group was 25 to 34 years. During the pandemic, 21% of respondents had increased and 33% decreased interest in at least one intervention. Non-invasive procedures (7.3%), facial aesthetic surgery (6.6%), and medical-grade skincare (5.9%) elicited the greatest interest increase. Seeing themselves in the mirror more often (43.2%), desire to look better after the crisis (41.8%), and increased time on social media (40.4%) were the top reasons for increased interest. The most common reasons for decreased interest were changing spending priorities (58%), focusing on other health aspects (49.8%), and worrying about infection in medical facilities (46.3%). Almost one-half of respondents considered virtual consultations for interventions of increased interest.

Conclusions: The COVID-19 pandemic significantly affected interest in medical aesthetics. Offering telemedicine and discussing detailed COVID-19 infection control policies with patients will be critical to address patient needs and concerns. These findings can be used to improve patient outreach, advertisement, and counseling as practices focus on reopening.
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http://dx.doi.org/10.1093/asj/sjaa173DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7665353PMC
February 2021

Data-Driven Insights on the Effects of COVID-19 on Aesthetics: Part I (Passive Analysis).

Aesthet Surg J 2021 Feb;41(3):NP65-NP74

Department of Plastic and Reconstructive Surgery, Johns Hopkins Hospital, Baltimore, MD.

Background: Since COVID-19 was declared to be a worldwide pandemic and US national emergency in March (week 11), it has significantly changed aesthetic plastic surgery. As plastic surgeons now move towards reopening practices, understanding public interest in medical aesthetics will be critical to maximize efforts and resource allocation in procedures and treatments that patients want.

Objectives: In this study, the authors sought to passively query public interest in aesthetics utilizing Google Trends search data.

Methods: Google Trends was utilized to quantify relative search volumes over the past 4 years for a variety of categories: patient-related, surgery-related, injectables, breast procedures, face procedures, and body procedures. Data were deseasonalized and represented graphically. Z-scores of each time-point differing from the expected values were determined utilizing least squares regression.

Results: Of the 204 significantly anomalous search term data points in 2020, 172 (84.0%) occurred after week 11 (pandemic/national emergency declaration). Sixty percent of searches in all time-points after week 11 significantly differed, and 25/26 (96.0%) search terms experienced significant changes after week 11. There was decreased interest for 18 terms with variable recovery. Procedural nadirs for decreased search volume troughs occurred between weeks 11 and 14. Six patient-related chief complaints saw increased search interest after COVID-19, with peak interest between weeks 11 and 17.

Conclusions: This is the first study, to the authors' knowledge, to assess real-time, national data about the impact of COVID-19 on public interest in aesthetics.
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http://dx.doi.org/10.1093/asj/sjaa246DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7499513PMC
February 2021

Prevention of Umbilical Sagging After Medium Definition Liposuction.

Aesthet Surg J 2021 03;41(4):463-473

Division of Plastic and Reconstructive Surgery, Emory University School of Medicine, Atlanta, GA.

Background: The loss of the umbilical vertical axis, causing a horizontal shape deformity after liposuction, is a current aesthetic issue. The use of energy devices, such as LASER and VASER, has been advocated as an option for improving skin retraction, but no data are available on the prevention of umbilical sagging.

Objectives: The authors sought to describe a technique for preventing umbilical deformities after medium definition liposuction employing suction-assisted liposuction.

Methods: Over a period of 31 months, 62 patients underwent medium definition liposuction with direct needle fixation of the umbilical stalk to prevent horizontal umbilical deformities. All patients underwent surgery performed by a single surgeon (G.B.). All patients underwent objective measurements of the umbilical shape before and after the procedure utilizing digital image measurements by Mirror Image software, version 6.0 (Fairfield, NJ). Statistical analysis was performed with IBM SPSS Statistics V26. The mean age of the patients was 28.8 years. The follow-up evaluation was performed 2 weeks and 9 months postoperatively.

Results: Over a period of 31 months, 60 patients (96.7%) who underwent abdominal etching liposuction showed maintenance of (n = 9, 14.5%) or improvements in the umbilical shape 9 months postoperatively (n = 51, 82.2%, P < 0.05). Two patients (3.2%) experienced worsening of the umbilical shape after surgery despite suture fixation.

Conclusions: Horizontal shape deformities of the umbilicus after liposuction can be improved by utilizing direct needle fixation of the umbilical stalk. The approach has been shown to be effective, safe, and reproducible for the prevention of umbilical sagging in selected patients.

Level Of Evidence: 4:
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http://dx.doi.org/10.1093/asj/sjaa051DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8240739PMC
March 2021

Nut consumption and metabolic syndrome in US adolescents.

Public Health Nutr 2018 12 4;21(17):3245-3252. Epub 2018 Sep 4.

2Children's Health,1935 Medical District,Dallas,TX,USA.

Objective: To determine whether nut intake is associated with the prevalence of metabolic syndrome in US adolescents.

Design: A cross-sectional analysis of data from the National Health and Nutrition Examination Survey (NHANES) years 2003-2012. Anthropometric measurements, blood tests, 24 h diet recalls and demographic data were retrieved for participating adolescents. Metabolic syndrome was defined according to paediatric-modified Adult Treatment Panel III criteria. The exposure was defined as a nut intake ≥5 g/d.

Setting: USA.

Subjects: Individuals aged 12-19 years (n 2805).

Results: Nut consumption was associated with lower odds for metabolic syndrome (crude OR=0·25; 95 % CI 0·11, 0·55; P≤0·001). This effect was independent of age, sex, race/ethnicity and family income:poverty ratio (adjusted OR=0·27; 95 % CI 0·12, 0·61; P=0·002), and was stable after controlling for nutritional covariates including intake of sugar and total energy consumption (OR=0·36; 95 % CI 0·16, 0·81; P=0·014).

Conclusion: Nut consumption of ≥5 g/d is independently associated with lower odds for metabolic syndrome in US adolescents.
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http://dx.doi.org/10.1017/S1368980018002070DOI Listing
December 2018

Isolation of Plasma Lipoproteins as a Source of Extracellular RNA.

Methods Mol Biol 2018 ;1740:139-153

Department of Surgery, University of California & VA Medical Center, San Francisco, CA, USA.

Plasma lipoproteins are essential vehicles of lipid distribution for cellular energy and structural requirements as well as for excretion of lipid excess. Imbalances in lipoprotein metabolism are known to contribute to metabolic diseases ranging from vascular inflammation and atherosclerosis to obesity and diabetes. The lipid and protein cargo carried by lipoprotein subclasses have long been the focus of studies exploring the contribution of plasma lipoproteins in health and in metabolic disorders. More recent studies have revealed the presence of noncoding RNA as a new form of cargo carried by plasma lipoproteins. Lipoprotein-associated microRNAs have been identified to distribute differentially among plasma lipoprotein subclasses and contribute to cellular signaling. These findings highlight plasma lipoprotein-associated RNA as a potential source of biological signaling and warrant a renewed interest in the study of plasma lipoprotein biology. This chapter describes principles and methods based on density ultracentrifugation and size exclusion chromatography for the isolation of plasma lipoproteins as a source of extracellular RNA.
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http://dx.doi.org/10.1007/978-1-4939-7652-2_11DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6476197PMC
January 2019

Oestrogen receptor β ligand acts on CD11c+ cells to mediate protection in experimental autoimmune encephalomyelitis.

Brain 2018 01;141(1):132-147

Multiple Sclerosis Program, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA.

Oestrogen treatments are neuroprotective in a variety of neurodegenerative disease models. Selective oestrogen receptor modifiers are needed to optimize beneficial effects while minimizing adverse effects to achieve neuroprotection in chronic diseases. Oestrogen receptor beta (ERβ) ligands are potential candidates. In the multiple sclerosis model chronic experimental autoimmune encephalomyelitis, ERβ-ligand treatment is neuroprotective, but mechanisms underlying this neuroprotection remain unclear. Specifically, whether there are direct effects of ERβ-ligand on CD11c+ microglia, myeloid dendritic cells or macrophages in vivo during disease is unknown. Here, we generated mice with ERβ deleted from CD11c+ cells to show direct effects of ERβ-ligand treatment in vivo on these cells to mediate neuroprotection during experimental autoimmune encephalomyelitis. Further, we use bone marrow chimeras to show that ERβ in peripherally derived myeloid cells, not resident microglia, are the CD11c+ cells mediating this protection. CD11c+ dendritic cell and macrophages isolated from the central nervous system of wild-type experimental autoimmune encephalomyelitis mice treated with ERβ-ligand expressed less iNOS and T-bet, but more IL-10, and this treatment effect was lost in mice with specific deletion of ERβ in CD11c+ cells. Also, we extend previous reports of ERβ-ligand’s ability to enhance remyelination through a direct effect on oligodendrocytes by showing that the immunomodulatory effect of ERβ-ligand acting on CD11c+ cells is necessary to permit the maturation of oligodendrocytes. Together these results demonstrate that targeting ERβ signalling pathways in CD11c+ myeloid cells is a novel strategy for regulation of the innate immune system in neurodegenerative diseases. To our knowledge, this is the first report showing how direct effects of a candidate neuroprotective treatment on two distinct cell lineages (bone marrow derived myeloid cells and oligodendrocytes) can have complementary neuroprotective effects in vivo.awx315media15688130498001.
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http://dx.doi.org/10.1093/brain/awx315DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5837360PMC
January 2018

Bedside to bench to bedside research: Estrogen receptor beta ligand as a candidate neuroprotective treatment for multiple sclerosis.

J Neuroimmunol 2017 03 3;304:63-71. Epub 2016 Oct 3.

Department of Neurology, University of California, Los Angeles, David Geffen School of Medicine, USA. Electronic address:

Protective effects of pregnancy during MS have led to clinical trials of estriol, the pregnancy estrogen, in MS. Since estriol binds to estrogen receptor (ER) beta, ER beta ligand could represent a "next generation estriol" treatment. Here, ER beta ligand treatment was protective in EAE in both sexes and across genetic backgrounds. Neuroprotection was shown in spinal cord, sparing myelin and axons, and in brain, sparing neurons and synapses. Longitudinal in vivo MRIs showed decreased brain atrophy in cerebral cortex gray matter and cerebellum during EAE. Investigation of ER beta ligand as a neuroprotective treatment for MS is warranted.
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http://dx.doi.org/10.1016/j.jneuroim.2016.09.017DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5806698PMC
March 2017

Establishment of the Pediatric Obesity Weight Evaluation Registry: A National Research Collaborative for Identifying the Optimal Assessment and Treatment of Pediatric Obesity.

Child Obes 2017 02 12;13(1):9-17. Epub 2016 Oct 12.

5 Helen DeVos Children's Hospital/Michigan State University , Grand Rapids, MI.

Background: Prospective patient registries have been successfully utilized in several disease states with a goal of improving treatment approaches through multi-institutional collaboration. The prevalence of youth with severe obesity is at a historic high in the United States, yet evidence to guide effective weight management is limited. The Pediatric Obesity Weight Evaluation Registry (POWER) was established in 2013 to identify and promote effective intervention strategies for pediatric obesity.

Methods: Sites in POWER provide multicomponent pediatric weight management (PWM) care for youth with obesity and collect a defined set of demographic and clinical parameters, which they regularly submit to the POWER Data Coordinating Center. A program profile survey was completed by sites to describe characteristics of the respective PWM programs.

Results: From January 2014 through December 2015, 26 US sites were enrolled in POWER and had submitted data on 3643 youth with obesity. Ninety-five percent were 6-18 years of age, 54% female, 32% nonwhite, 32% Hispanic, and 59% publicly insured. Over two-thirds had severe obesity. All sites included a medical provider and used weight status in their referral criteria. Other program characteristics varied widely between sites.

Conclusion: POWER is an established national registry representing a diverse sample of youth with obesity participating in multicomponent PWM programs across the United States. Using high-quality data collection and a collaborative research infrastructure, POWER aims to contribute to the development of evidence-based guidelines for multicomponent PWM programs.
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http://dx.doi.org/10.1089/chi.2016.0060DOI Listing
February 2017

Concordance analysis and diagnostic test accuracy review of IDH1 immunohistochemistry in glioblastoma.

Brain Tumor Pathol 2016 Oct 16;33(4):248-254. Epub 2016 Sep 16.

Department of Pathology, Inje University Sanggye Paik Hospital, 1342 Dongil-ro, Nowon-gu, Seoul, 139-707, Republic of Korea.

The study investigated isocitrate dehydrogenase (IDH) 1 immunohistochemistry (IHC) positive rate and concordance rate between IDH1 IHC and molecular test in glioblastoma. The current study included 1360 glioblastoma cases from sixteen eligible studies. Meta-analysis, including subgroup analysis by antibody clones and cut-off values, for IDH1 IHC positive rate was conducted. In addition, we performed a concordance analysis and diagnostic test accuracy review between IDH1 IHC and molecular tests. The estimated rates of IDH1 IHC were 0.106 [95 % confidence interval (CI) 0.085-0.132]. The IDH1 IHC positive rate of primary and secondary glioblastomas was 0.049 (95 % CI 0.023-0.99) and 0.729 (95 % CI 0.477-0.889), respectively. The overall concordance rate between IDH1 IHC and molecular test was 0.947 (95 % CI 0.878-0.978). In IDH1 IHC-positive and negative subgroups, the concordance rate was 0.842 (95 % CI 0.591-0.952) and 0.982 (95 % CI 0.941-0.995), respectively. The pooled sensitivity and specificity for IDH1 IHC were 1.00 (95 % CI 0.82-1.00) and 0.99 (95 % CI 0.96-1.00), respectively. IDH1 IHC is an accurate test for IDH1 mutation in glioblastoma patients. Further cumulative studies for evaluation criteria of IDH1 IHC will determine how to best apply this approach in daily practice.
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http://dx.doi.org/10.1007/s10014-016-0272-6DOI Listing
October 2016

Cystic Fibrosis-Related Diabetes in Children: An Update.

Authors:
Roy J Kim

Pediatr Ann 2016 Sep;45(9):e321-6

Cystic fibrosis-related diabetes mellitus (CFRD) is the most common endocrine complication of cystic fibrosis (CF), affecting more than 50% of patients by the 4th decade of life. CFRD is often preceded by worsening pulmonary status and nutritional decline. Treatment of CFRD is associated with improvements in body weight and pulmonary function and a reduction in pulmonary exacerbations. Because of the clinical significance of CFRD, diabetes screening with an oral glucose tolerance test (OGTT) is recommended annually for all patients with CF starting at age 10 years. The OGTT detects CFRD with greater sensitivity than random glucose or hemoglobin A1c testing. The first-line treatment for CFRD is insulin. The use of other treatments such as oral medications remains under study. [Pediatr Ann. 2016;45(9):e321-e326.].
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http://dx.doi.org/10.3928/19382359-20160815-01DOI Listing
September 2016

Immunosuppression With FTY720 Reverses Cardiac Dysfunction in Hypomorphic ApoE Mice Deficient in SR-BI Expression That Survive Myocardial Infarction Caused by Coronary Atherosclerosis.

J Cardiovasc Pharmacol 2016 Jan;67(1):47-56

Departments of *Surgery; and †Medicine, San Francisco VA Medical Center, University of California, San Francisco, San Francisco, CA.

Aims: We recently reported that immunosuppression with FTY720 improves cardiac function and extends longevity in Hypomorphic ApoE mice deficient in scavenger receptor Type-BI expression, also known as the HypoE/SR-BI(–/–) mouse model of diet-induced coronary atherosclerosis and myocardial infarction (MI). In this study, we tested the impact of FTY720 on cardiac dysfunction in HypoE/SR-BI(–/–) mice that survive MI and subsequently develop chronic heart failure.

Methods/results: HypoE/SR-BI(–/–) mice were bred to Mx1-Cre transgenic mice, and offspring were fed a high-fat diet (HFD) for 3.5 weeks to provoke hyperlipidemia, coronary atherosclerosis, and recurrent MIs. In contrast to our previous study, hyperlipidemia was rapidly reversed by inducible Cre-mediated gene repair of the HypoE allele and switching mice to a normal chow diet. Mice that survived the period of HFD were subsequently given oral FTY720 in drinking water or not, and left ventricular (LV) function was monitored using serial echocardiography for up to 15 weeks. In untreated mice, LV performance progressively deteriorated. Although FTY720 treatment did not initially prevent a decline of heart function among mice 6 weeks after Cre-mediated gene repair, it almost completely restored normal LV function in these mice by 15 weeks. Reversal of heart failure did not result from reduced atherosclerosis as the burden of aortic and coronary atherosclerosis actually increased to similar levels in both groups of mice. Rather, FTY720 caused systemic immunosuppression as assessed by reduced numbers of circulating T and B lymphocytes. In contrast, FTY720 did not enhance the loss of T cells or macrophages that accumulated in the heart during the HFD feeding period, but it did enhance the loss of B cells soon after plasma lipid lowering. Moreover, FTY720 potently reduced the expression of matrix metalloproteinase-2 and genes involved in innate immunity-associated inflammation in the heart.

Conclusions: Our data demonstrate that immunosuppression with FTY720 prevents postinfarction myocardial remodeling and chronic heart failure.
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http://dx.doi.org/10.1097/FJC.0000000000000312DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4703534PMC
January 2016

A screen in mice uncovers repression of lipoprotein lipase by microRNA-29a as a mechanism for lipid distribution away from the liver.

Hepatology 2015 Jan 24;61(1):141-52. Epub 2014 Nov 24.

Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, San Francisco, CA; Department of Pathology, University of California San Francisco, San Francisco, CA; Liver Center, University of California San Francisco, San Francisco, CA.

Unlabelled: Identification of microRNAs (miRNAs) that regulate lipid metabolism is important to advance the understanding and treatment of some of the most common human diseases. In the liver, a few key miRNAs have been reported that regulate lipid metabolism, but since many genes contribute to hepatic lipid metabolism, we hypothesized that other such miRNAs exist. To identify genes repressed by miRNAs in mature hepatocytes in vivo, we injected adult mice carrying floxed Dicer1 alleles with an adenoassociated viral vector expressing Cre recombinase specifically in hepatocytes. By inactivating Dicer in adult quiescent hepatocytes we avoided the hepatocyte injury and regeneration observed in previous mouse models of global miRNA deficiency in hepatocytes. Next, we combined gene and miRNA expression profiling to identify candidate gene/miRNA interactions involved in hepatic lipid metabolism and validated their function in vivo using antisense oligonucleotides. A candidate gene that emerged from our screen was lipoprotein lipase (Lpl), which encodes an enzyme that facilitates cellular uptake of lipids from the circulation. Unlike in energy-dependent cells like myocytes, LPL is normally repressed in adult hepatocytes. We identified miR-29a as the miRNA responsible for repressing LPL in hepatocytes, and found that decreasing hepatic miR-29a levels causes lipids to accumulate in mouse livers.

Conclusion: Our screen suggests several new miRNAs are regulators of hepatic lipid metabolism. We show that one of these, miR-29a, contributes to physiological lipid distribution away from the liver and protects hepatocytes from steatosis. Our results, together with miR-29a's known antifibrotic effect, suggest miR-29a is a therapeutic target in fatty liver disease.
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http://dx.doi.org/10.1002/hep.27379DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4465779PMC
January 2015

Astrocyte CCL2 sustains immune cell infiltration in chronic experimental autoimmune encephalomyelitis.

J Neuroimmunol 2014 Sep 24;274(1-2):53-61. Epub 2014 Jun 24.

Multiple Sclerosis Program, Department of Neurology, University of California, Los Angeles. Electronic address:

Chemokine (C-C motif) ligand 2 (CCL2), initially identified as monocyte chemoattractant protein-1 (MCP-1), recruits immune cells to the central nervous system (CNS) during autoimmune inflammation. CCL2 can be expressed by multiple cell types, but which cells are responsible for CCL2 function during acute and chronic phases of autoimmune disease is not known. We determined the role of CCL2 in astrocytes in vivo during experimental autoimmune encephalomyelitis (EAE) by using Cre-loxP gene deletion. Mice with a conditional gene deletion of CCL2 from astrocytes had less severe EAE late in disease while having a similar incidence and severity of disease at onset as compared to wild type (WT) control littermates. EAE mice devoid of CCL2 in astrocytes had less macrophage and T cell inflammation in the white matter of the spinal cord and less diffuse activation of astrocytes and microglia in both white and gray matter as well as less axonal loss and demyelination, compared to WT littermates. These findings demonstrate that CCL2 in astrocytes plays an important role in the continued recruitment of immune cells and activation of glial cells in the CNS during chronic EAE, thereby suggesting a novel cell specific target for neuroprotective treatments of chronic neuroinflammatory diseases.
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http://dx.doi.org/10.1016/j.jneuroim.2014.06.009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4343306PMC
September 2014

The immunosuppressant FTY720 prolongs survival in a mouse model of diet-induced coronary atherosclerosis and myocardial infarction.

J Cardiovasc Pharmacol 2014 Feb;63(2):132-143

Surgical Service, VA Medical Center, San Francisco and the Department of Surgery, University of California, San Francisco.

FTY720, an analogue of sphingosine-1-phosphate, is cardioprotective during acute injury. Whether long-term FTY720 affords cardioprotection is unknown. Here, we report the effects of oral FTY720 on ischemia/reperfusion injury and in hypomorphic apoE mice deficient in SR-BI receptor expression (ApoeR61(h/h)/SRB1(-/- mice), a model of diet-induced coronary atherosclerosis and heart failure. We added FTY720 (0.3 mg·kg(-1)·d(-1)) to the drinking water of C57BL/6J mice. After ex vivo cardiac ischemia/reperfusion injury, these mice had significantly improved left ventricular (LV) developed pressure and reduced infarct size compared with controls. Subsequently, ApoeR61(h/h)/SRB1(-/-) mice fed a high-fat diet for 4 weeks were treated or not with oral FTY720 (0.05 mg·kg(-1)·d(-1)). This sharply reduced mortality (P < 0.02) and resulted in better LV function and less LV remodeling compared with controls without reducing hypercholesterolemia and atherosclerosis. Oral FTY720 reduced the number of blood lymphocytes and increased the percentage of CD4+Foxp3+ regulatory T cells (Tregs) in the circulation, spleen, and lymph nodes. FTY720-treated mice exhibited increased TGF-β and reduced IFN-γ expression in the heart. Also, CD4 expression was increased and strongly correlated with molecules involved in natural Treg activity, such as TGF-β and GITR. Our data suggest that long-term FTY720 treatment enhances LV function and increases longevity in mice with heart failure. These benefits resulted not from atheroprotection but from systemic immunosuppression and a moderate reduction of inflammation in the heart.
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http://dx.doi.org/10.1097/FJC.0000000000000031DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4574629PMC
February 2014

In vitro and in vivo effects of IGF-I on adiposity in HIV-associated metabolic disease: a pilot study.

Arch Med Res 2013 Jul 16;44(5):361-9. Epub 2013 Jul 16.

Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas. Electronic address:

Background And Aims: We tested the effects of recombinant insulin-like growth factor-I (IGF-I) in an adipocyte model of HIV lipodystrophy and in an open label study on body composition and metabolism in patients with HIV lipodystrophy.

Methods: The effects of IGF-I on ritonavir-induced adipocyte cell death were studied in vitro. We assessed lipid accumulation, IGF signaling, apoptosis, and gene expression. We conducted a 24-week open label trial of recombinant IGF-I in ten adults with HIV associated lipoatrophy. Laboratory assessments included glucose, insulin, lipids, and IGF-I. At weeks 0 and 24, body composition studies were performed including skinfold measurement, dual-energy x-ray absorptiometry, and computed tomography of the abdomen and thigh.

Results: In vitro, ritonavir increased delipidation and apoptosis of adipocytes, whereas co-treatment with IGF-I attenuated the effect. In the clinical study, subcutaneous adipose tissue did not increase in patients after treatment with IGF-I; however, there was a decrease in the proportion of abdominal fat (39.8 ± 7% vs. 34.6 ± 7%, p = 0.007). IGF-I levels increased with treatment (143 ± 28 μg/L at week 0 vs. 453 ± 212 μg/L at week 24, p = 0.002), whereas IGFBP-3 levels declined (3.554 ± 1.146 mg/L vs. 3.235 ± 1.151 mg/L, p = 0.02). Insulin at week 12 decreased significantly (90.1 ± 39.8 pmol/L vs. 33.2 ± 19.6 pmol/L, p = 0.002). There was a nonsignificant decrease in visceral adipose tissue (155.2 ± 68 cm² at week 0 vs. 140.6 ± 70 cm² at week 24, p = 0.08).

Conclusions: Use of recombinant IGF-I may lower fasting insulin and abdominal fat in patients with lipoatrophy associated with HIV infection. Further evaluation of this agent for treatment of HIV-associated lipodystrophy may be warranted.
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http://dx.doi.org/10.1016/j.arcmed.2013.06.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4234118PMC
July 2013

Inducible ApoE gene repair in hypomorphic ApoE mice deficient in the low-density lipoprotein receptor promotes atheroma stabilization with a human-like lipoprotein profile.

Arterioscler Thromb Vasc Biol 2013 Aug 20;33(8):1759-67. Epub 2013 Jun 20.

Division of Vascular and Endovascular Surgery, Department of Surgery, VA Medical Center, University of California San Francisco, CA 94121, USA.

Objective: To study atherosclerosis regression in mice after plasma lipid reduction to moderately elevated apolipoprotein B (apoB)-lipoprotein levels.

Approach And Results: Chow-fed hypomorphic Apoe mice deficient in low-density lipoprotein receptor expression (Apoe(h/h)Ldlr(-/-)Mx1-cre mice) develop hyperlipidemia and atherosclerosis. These mice were studied before and after inducible cre-mediated Apoe gene repair. By 1 week, induced mice displayed a 2-fold reduction in plasma cholesterol and triglyceride levels and a decrease in the non-high-density lipoprotein:high-density lipoprotein-cholesterol ratio from 87%:13% to 60%:40%. This halted atherosclerotic lesion growth and promoted macrophage loss and accumulation of thick collagen fibers for up to 8 weeks. Concomitantly, blood Ly-6C(high) monocytes were decreased by 2-fold but lesional macrophage apoptosis was unchanged. The expression of several genes involved in extracellular matrix remodeling and cell migration was changed in lesional macrophages 1 week after Apoe gene repair. However, mRNA levels of numerous genes involved in cholesterol efflux and inflammation were not significantly changed at this time point.

Conclusions: Restoring apoE expression in Apoe(h/h)Ldlr(-/-)Mx1-cre mice resulted in lesion stabilization in the context of a human-like ratio of non-high-density lipoprotein:high-density lipoprotein-cholesterol. Our data suggest that macrophage loss derived in part from reduced blood Ly-6C(high) monocytes levels and genetic reprogramming of lesional macrophages.
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http://dx.doi.org/10.1161/ATVBAHA.112.300605DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3811094PMC
August 2013

Physical activity and sedentary behavior of cancer survivors and non-cancer individuals: results from a national survey.

PLoS One 2013 6;8(3):e57598. Epub 2013 Mar 6.

Virginia Commonwealth University School of Medicine, Richmond, VA, USA.

Increasing physical activity and decreasing sedentary behavior are associated with a higher quality of life and lower mortality rates for cancer survivors, a growing population group. Studies detailing the behavior of cancer survivors are limited. Therefore, we investigated physical activity and sedentary behavior of cancer survivors using data from the National Health and Nutrition Examination Survey (NHANES) 2007-2010. Participants were those who provided physical activity and sedentary behavior data. Those who were pregnant, <20 years old, or <3 years from their cancer diagnosis were excluded. A cancer case was a self-reported diagnosis by a physician. We identified 741 cancer survivors and 10,472 non-cancer participants. After adjustment for age, race, gender, education status, body mass index, and smoking status, cancer survivors (n = 10,472) reported significantly longer duration of sedentary behavior (OR = 1.42, 95% CI (1.12, 1.80) for 8 or more hours, p-value for trend = 0.09), compared to non-cancer participants (n = 741). They also reported non-significant increases in maximum intensity, duration, frequency, and energy expenditure, whereas they reported significant increases in moderate intensity (OR = 1.26, 95% CI (1.01, 1.57)), moderate frequency (1-4 times/week) (OR = 1.32, 95% CI (1.00, 1.74)), and moderate energy expenditure (4018.5-7623.5 kcal) (OR = 1.30, 95% CI (1.00, 1.71)) of physical activity, compared to non-cancer participants. These patterns are similar for breast and prostate cancer survivors, with prostate cancer survivors more likely to engage in physical activity for more than one hour per day (OR = 1.98, 95% CI (1.05, 3.71)). Our findings suggest that cancer survivors tend to have more physical activity, but they are also more likely to engage in sedentary behavior.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0057598PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3590221PMC
September 2013

Apolipoprotein E4 domain interaction accelerates diet-induced atherosclerosis in hypomorphic Arg-61 apoe mice.

Arterioscler Thromb Vasc Biol 2012 May 22;32(5):1116-23. Epub 2012 Mar 22.

Department of Surgery, University of California San Francisco and VA Medical Center, San Francisco, CA 94121, USA.

Objective: Apolipoprotein (apo) E4 is an established risk factor for atherosclerosis, but the structural components underlying this association remain unclear. ApoE4 is characterized by 2 biophysical properties: domain interaction and molten globule state. Substituting Arg-61 for Thr-61 in mouse apoE introduces domain interaction without molten globule state, allowing us to delineate potential proatherogenic effects of domain interaction in vivo.

Methods And Results: We studied atherosclerosis susceptibility of hypomorphic Apoe mice expressing either Thr-61 or Arg-61 apoE (ApoeT(h/h) or ApoeR(h/h)mice). On a chow diet, both mouse models were normolipidemic with similar levels of plasma apoE and lipoproteins. However, on a high-cholesterol diet, ApoeR(h/h) mice displayed increased levels of total plasma cholesterol and very-low-density lipoprotein as well as larger atherosclerotic plaques in the aortic root, arch, and descending aorta compared with ApoeT(h/h) mice. In addition, evidence of cellular dysfunction was identified in peritoneal ApoeR(h/h) macrophages which released lower amounts of apoE in culture medium and displayed increased expression of major histocompatibility complex class II molecules.

Conclusions: These data indicate that domain interaction mediates proatherogenic effects of apoE4 in part by modulating lipoprotein metabolism and macrophage biology. Pharmaceutical targeting of domain interaction could lead to new treatments for atherosclerosis in apoE4 individuals.
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http://dx.doi.org/10.1161/ATVBAHA.112.246389DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3346714PMC
May 2012

ApoE suppresses atherosclerosis by reducing lipid accumulation in circulating monocytes and the expression of inflammatory molecules on monocytes and vascular endothelium.

Arterioscler Thromb Vasc Biol 2012 Feb 3;32(2):264-72. Epub 2011 Nov 3.

Department of Surgery, University of California San Francisco and VA Medical Center, 4150 Clement Street, San Francisco, CA 94121, USA.

Objective: We investigated atheroprotective properties of apolipoprotein (apo) E beyond its ability to lower plasma cholesterol. We hypothesized that apoE reduces atherosclerosis by decreasing lipid accumulation in circulating monocytes and the inflammatory state of monocytes and the vascular endothelium.

Methods And Results: We developed mice with spontaneous hyperlipidemia with and without plasma apoE. Hypomorphic apoE mice deficient in low-density lipoprotein receptor (Apoe(h/h)Ldlr(-/-)) were compared to Apoe(-/-)Ldlr(-/-) mice. Despite 4-fold more plasma apoE than WT mice, Apoe(h/h)Ldlr(-/-) mice displayed similar plasma cholesterol as Apoe(-/-) Ldlr(-/-) mice but developed 4-fold less atherosclerotic lesions by 5 months of age. The aortic arch of Apoe(h/h)Ldlr(-/-) mice showed decreased endothelial expression of ICAM-1, PECAM-1, and JAM-A. In addition, Apoe(h/h)Ldlr(-/-) mice had less circulating leukocytes and proinflammatory Ly6C(high) monocytes. These monocytes had decreased neutral lipid content and reduced surface expression of ICAM-1, VLA-4, and L-Selectin. Apoe(h/h)Ldlr(-/-) mice displayed increased levels of apoA1-rich HDL that were potent in promoting cellular cholesterol efflux.

Conclusions: Our findings suggest that apoE reduces atherosclerosis in the setting of hyperlipidemia by increasing plasma apoA1-HDL that likely contribute to reduce intracellular lipid accumulation and thereby the activation of circulating leukocytes and the vascular endothelium.
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http://dx.doi.org/10.1161/ATVBAHA.111.238964DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3275345PMC
February 2012

Radioprotective effects of Bmi-1 involve epigenetic silencing of oxidase genes and enhanced DNA repair in normal human keratinocytes.

J Invest Dermatol 2011 Jun 10;131(6):1216-25. Epub 2011 Feb 10.

UCLA School of Dentistry, Center for the Health Sciences, Los Angeles, California 90095, USA.

Normal human keratinocytes (NHKs) undergo premature senescence following exposure to ionizing radiation (IR). This study investigates the effect of Bmi-1, a polycomb group protein, on radiation-induced senescence response. When exposed to IR, NHK transduced with Bmi-1 (NHK/Bmi-1) showed reduced senescent phenotype and enhanced proliferation compared with control cells (NHK/B0). To investigate the underlying mechanism, we determined the production of reactive oxygen species (ROS), expression of ROS-generating enzymes, and DNA repair activities in cells. ROS level was increased upon irradiation but notably reduced by Bmi-1 transduction. Irradiation led to strong induction of oxidase genes, e.g., Lpo (lactoperoxidase), p22-phox, p47-phox, and Gp91, in NHK/B0 but their expression was almost completely silenced in NHK/Bmi-1. Induction of oxidase genes upon irradiation was linked with loss of trimethylated histone 3 at lysine 27 (H3K27Me3), but NHK/Bmi-1 expressed a higher level of H3K27Me3 compared with NHK/B0. Bmi-1 transduction suppressed IR-associated induction of jumanji domain containing 3 while enhancing the expression of EZH2, thereby preventing the loss of H3K27Me3 in the irradiated cells. Furthermore, NHK/Bmi-1 demonstrated increased repair of IR-induced DNA damage compared with NHK/B0. These results indicate that Bmi-1 elicits radioprotective effects on NHK by mitigating the genotoxicity of IR through epigenetic mechanisms.
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http://dx.doi.org/10.1038/jid.2011.11DOI Listing
June 2011

Impact of antiretroviral therapy on growth, body composition and metabolism in pediatric HIV patients.

Paediatr Drugs 2010 Jun;12(3):187-99

Division of Endocrinology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA.

Highly active antiretroviral therapy improves survival and growth in children with HIV infection. However, its use can be associated with adverse changes in body composition and metabolism. Bone mineral density can be adversely affected in HIV-positive children due to nutritional compromise or certain antiretrovirals. HIV-associated lipodystrophy, consisting of redistribution of adipose tissue, insulin resistance, and dyslipidemia, has also been described in children. Pediatric HIV patients may be at greater risk for these problems because of their longer potential lifetime exposure to these agents and because childhood is normally a period of rapid growth and tissue accretion. Healthcare providers for children with HIV infection must be aware of the potential complications associated with HIV antiretrovirals so that their antiviral efficacy can be balanced against their risk for side effects. In this review, we discuss the alterations in childhood growth and body composition that occur in HIV-infected children, and describe the impact of antiretroviral therapy on these outcomes. The problem of HIV-associated lipodystrophy syndrome in children is also discussed. Children with HIV should have their growth and body composition systematically monitored. Antiretroviral regimens should be tailored to optimize adherence and viral suppression while minimizing the potential for adverse side effects.
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http://dx.doi.org/10.2165/11532520-000000000-00000DOI Listing
June 2010

Energy expenditure in obesity associated with craniopharyngioma.

Childs Nerv Syst 2010 Jul 27;26(7):913-7. Epub 2010 Jan 27.

Division of Endocrinology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.

Background And Purpose: Obesity is a common yet incompletely understood complication of childhood craniopharyngioma. We hypothesized that craniopharyngioma is associated with specific defects in energy balance compared to obese control children.

Methods: Eleven craniopharyngioma patients were recruited for a study on body composition and energy balance. Eight subjects were obese. The obese craniopharyngioma patients had a mean age (+/-SD) of 11.2 +/- 1.7 years. The average body mass index z score was 2.33 (+/-0.32). A previously studied group of obese children (BMI z score 2.46 +/- 0.46) served as controls. Resting energy expenditure (REE) was determined by indirect calorimetry and body composition by dual energy X-ray absorptiometry in all children.

Results: Obese craniopharyngioma patient subjects had increased mean (+/-standard error) fat-free mass compared to obese controls (57% +/- 0.88 % vs 50.0% +/- 0.87%, p = 0.02). The obese craniopharyngioma patients had a 17% lower REE compared to values expected from the World Health Organization equation (1,541 +/- 112.6 vs 1,809 +/- 151.8 kcal; p = 0.01). In contrast, the obese control children had measured REE within 1% of predicted (1,647 +/- 33.2 vs. 1,652 +/- 40.2; p = 0.8). In a linear regression model, REE remained significantly lower than predicted after controlling for FFM.

Conclusions: Lower REE may be a factor contributing to obesity in children with craniopharyngioma. Further study is needed into the mechanisms for reduced energy expenditure in patients with craniopharyngioma.
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http://dx.doi.org/10.1007/s00381-009-1078-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2883002PMC
July 2010

Interferon gamma attenuates insulin signaling, lipid storage, and differentiation in human adipocytes via activation of the JAK/STAT pathway.

J Biol Chem 2009 Nov 23;284(46):31936-44. Epub 2009 Sep 23.

Cardiovascular Institute, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA.

Recent reports demonstrate T-cell infiltration of adipose tissue in early obesity. We hypothesized that interferon (IFN) gamma, a major T-cell inflammatory cytokine, would attenuate human adipocyte functions and sought to establish signaling mechanisms. Differentiated human adipocytes were treated with IFNgamma +/- pharmacological inhibitors prior to insulin stimulation. [(3)H]Glucose uptake and AKT phosphorylation were assessed as markers of insulin sensitivity. IFNgamma induced sustained loss of insulin-stimulated glucose uptake in human adipocytes, coincident with reduced Akt phosphorylation and down-regulation of the insulin receptor, insulin receptor substrate-1, and GLUT4. Loss of adipocyte triglyceride storage was observed with IFNgamma co-incident with reduced expression of peroxisome proliferator-activated receptor gamma, adiponectin, perilipin, fatty acid synthase, and lipoprotein lipase. Treatment with IFNgamma also blocked differentiation of pre-adipocytes to the mature phenotype. IFNgamma-induced robust STAT1 phosphorylation and SOCS1 mRNA expression, with modest, transient STAT3 phosphorylation and SOCS3 induction. Preincubation with a non-selective JAK inhibitor restored glucose uptake and Akt phosphorylation while completely reversing IFNgamma suppression of adipogenic mRNAs and adipocyte differentiation. Specific inhibition of JAK2 or JAK3 failed to block IFNgamma effects suggesting a predominant role for JAK1-STAT1. We demonstrate that IFNgamma attenuates insulin sensitivity and suppresses differentiation in human adipocytes, an effect most likely mediated via sustained JAK-STAT1 pathway activation.
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http://dx.doi.org/10.1074/jbc.M109.061655DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2797265PMC
November 2009

Gene profiling of human adipose tissue during evoked inflammation in vivo.

Diabetes 2009 Oct 6;58(10):2211-9. Epub 2009 Jul 6.

Division of Pediatric Endocrinology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.

Objective: Adipose inflammation plays a central role in obesity-related metabolic and cardiovascular complications. However, few human adipose-secreted proteins are known to mediate these processes. We hypothesized that microarray mRNA profiling of human adipose during evoked inflammation could identify novel adipocytokines.

Research Design And Methods: Healthy human volunteers (n = 14) were treated with intravenous endotoxin (3 ng/kg lipopolysaccharide [LPS]) and underwent subcutaneous adipose biopsies before and after LPS. On Affymetrix U133Plus 2.0 arrays, adipose mRNAs modulated >1.5-fold (with P < 0.00001) were selected. SignalP 3.0 and SecretomeP 2.0 identified genes predicted to encode secreted proteins. Of these, 86 candidates were chosen for validation in adipose from an independent human endotoxemia protocol (N = 7, with 0.6 ng/kg LPS) and for exploration of cellular origin in primary human adipocytes and macrophages in vitro.

Results: Microarray identified 776 adipose genes modulated by LPS; 298 were predicted to be secreted. Of detectable prioritized genes, 82 of 85 (96% [95% CI 90-99]) were upregulated (fold changes >1.0) during the lower-dose (LPS 0.6 ng/kg) validation study and 51 of 85 (59% [49-70]) were induced greater than 1.5-fold. Treatment of primary adipocytes with LPS and macrophage polarization to M1 proinflammatory phenotype increased expression by 1.5-fold for 58 and 73% of detectable genes, respectively.

Conclusions: We demonstrate that evoked inflammation of human adipose in vivo modulated expression of multiple genes likely secreted by adipocytes and monocytes. These included established adipocytokines and chemokines implicated in recruitment and activation of lymphocytes, adhesion molecules, antioxidants, and several novel genes with unknown function. Such candidates may represent biomarkers and therapeutic targets for obesity-related complications.
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http://dx.doi.org/10.2337/db09-0256DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2750231PMC
October 2009

Retinol saturase promotes adipogenesis and is downregulated in obesity.

Proc Natl Acad Sci U S A 2009 Jan 12;106(4):1105-10. Epub 2009 Jan 12.

Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and The Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.

Adipocyte differentiation is controlled by many transcription factors, but few known downstream targets of these factors are necessary for adipogenesis. Here we report that retinol saturase (RetSat), which is an enzyme implicated in the generation of dihydroretinoid metabolites, is induced during adipogenesis and is directly regulated by the transcription factor peroxisome proliferator activated receptor gamma (PPARgamma). Ablation of RetSat dramatically inhibited adipogenesis but, surprisingly, this block was not overcome by the putative product of RetSat enzymatic activity. On the other hand, ectopic RetSat with an intact, but not a mutated, FAD/NAD dinucleotide-binding motif increased endogenous PPARgamma transcriptional activity and promoted adipogenesis. Indeed, RetSat was not required for adipogenesis when cells were provided with exogenous PPARgamma ligands. In adipose tissue, RetSat is expressed in adipocytes but is unexpectedly downregulated in obesity, most likely owing to infiltration of macrophages that we demonstrate to repress RetSat expression. Thiazolidinedione treatment reversed low RetSat expression in adipose tissue of obese mice. Thus, RetSat plays an important role in the biology of adipocytes, where it favors normal differentiation, yet is reduced in the obese state. RetSat is thus a novel target for therapeutic intervention in metabolic disease.
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http://dx.doi.org/10.1073/pnas.0812065106DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2633572PMC
January 2009

Association of hsp90 to the hTERT promoter is necessary for hTERT expression in human oral cancer cells.

Carcinogenesis 2008 Dec 26;29(12):2425-31. Epub 2008 Sep 26.

University of California, Los Angeles School of Dentistry, Center for the Health Sciences, Los Angeles, CA 90095, USA.

Enhanced expression of human telomerase reverse transcriptase (hTERT) occurs frequently during cellular immortalization. The current study was undertaken to determine the mechanism regulating the hTERT promoter activity during cellular immortalization of human oral keratinocytes. Normal human oral keratinocytes (NHOKs) were immortalized with Bmi-1 and the E6 oncoprotein of human papillomavirus type 16 to establish the telomerase-positive HOK-Bmi-1/E6 cell line. Using DNA-protein-binding assay, we found that heat shock protein 90 (hsp90) physically interacts with the hTERT promoter in vitro. The hsp90 interaction with the promoter was detected more strongly in the telomerase-positive HOK-Bmi-1/E6 cells compared with that in senescing NHOK. Chromatin immunoprecipitation confirmed the in vivo interaction between hsp90 and the hTERT promoter in SCC4 cells, a telomerase-positive oral cancer cell line, but not in the NHOK. To determine the physiological significance of this interaction, SCC4 cells were exposed to geldanamycin (GA), a competitive inhibitor of hsp90. GA exposure led to decrease in telomerase activity, hTERT promoter activity and hTERT messenger RNA expression in SCC4 cells, even in the absence of de novo protein synthesis. Also, it abolished the in vivo interaction of the hTERT promoter region with hsp90 but not with Sp1 or c-Myc. These results indicate that physical interaction between hsp90 and the hTERT promoter occurs in telomerase-positive cells but not in normal human cells and is necessary for the enhanced hTERT expression and telomerase activity in cancer cells.
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http://dx.doi.org/10.1093/carcin/bgn225DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2639246PMC
December 2008
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