ABSTRACT
In recent history, the world has witnessed a trend towards liberalization of abortion laws driven by an increasing understanding of the negative personal and public health consequences of criminalizing abortion. By contrast, several countries have recently implemented restrictive reproductive laws, joining the 112 countries where access to abortion care is banned completely or with narrow exceptions. On June 24, 2022, the US Supreme Court ruling in Dobbs v Jackson Women's Health Organization overturned its landmark decisions in Roe v Wade that established abortion until the point of viability of the fetus as a constitutional right. After Roe v Wade having been overturned, it is projected that many women in the USA will be prevented from accessing safe abortion care. Importantly, abortion bans not only impose constraints on patient autonomy, they also restrict physicians' ability to practice evidence-based medicine, which will negatively impact psychiatric care. It is therefore crucial for the practicing psychiatrist to be familiar with this new legal landscape. In this Personal View, we aim to provide a topical overview to help clinicians gain a clear understanding of legal, clinical, and ethical responsibilities, focusing on the USA. We also discuss the reality that psychiatrists might be called upon to determine medical necessity for an abortion on psychiatric grounds, which is new for most US psychiatrists. We predict that psychiatrists will be confronted with very difficult situations in which lawful and ethical conduct might be incongruent, and that abortion bans will result in greater numbers of patients needing psychiatric care from a system that is ill-prepared for additional demands.
ABSTRACT
Introduction: Impactful, transdisciplinary scientific discoveries are created by teams of researchers spanning multiple disciplines, but collaboration across disciplines can be challenging. We examined how team dynamics and collaboration are related to successes and barriers faced by teams of researchers from multiple disciplines. Methods: A mixed-methods approach was used to examine 12 research teams granted multidisciplinary pilot awards. Team members were surveyed to assess their team dynamics and individual views about transdisciplinary research. Forty-seven researchers (59.5%) responded, including two to eight members from each funded team. Associations were examined between collaborative dynamics and scholarly product outcomes, including manuscripts, grant proposals, and awarded grants. One member from each team was selected for an in-depth interview to contextualize and extend information about collaborative processes, successes, and barriers to performing transdisciplinary research. Results: Quality of team interactions was positively associated with achievement of scholarly products (r = 0.64, p = 0.02). Satisfaction with team members (r = 0.38) and team collaboration scores (r = 0.43) also demonstrated positive associations with achievement of scholarly products, but these were not statistically significant. Qualitative results support these findings and add further insight into aspects of the collaborative process that were particularly important to foster success on multidisciplinary teams. Beyond scholarly metrics, additional successes from the multidisciplinary teams were identified through the qualitative portion of the study including career development and acceleration for early career researchers. Conclusions: Both the quantitative and qualitative study results indicate that effective collaboration is critical to multidisciplinary research team success. Development and/or promotion of team science-based trainings for researchers would promote these collaborative skills.
ABSTRACT
BACKGROUND: The deficit syndrome is a clinical subtype of schizophrenia that is characterized by enduring negative symptoms. Several lines of evidence point to frontoparietal involvement, but the frontoparietal control network (FPCN) and its subsystems (FPCNA and FPCNB) proposed by Yeo et al. have not been systematically characterized at rest in patients with the deficit syndrome. METHODS: We used resting-state fMRI to investigate the FPCN and its subnetworks in 72 healthy controls and 65 antipsychotic medication-naive, first-episode psychosis patients (22 displayed deficit syndrome features, 43 did not). To assess whole-brain FPCN connectivity, we used the right posterior parietal cortex as the seed region. We then performed region of interest analyses in FPCN subsystems. RESULTS: We found that patterns of FPCN dysconnectivity to the whole brain differed in patients who displayed deficit syndrome features compared with those who did not. Examining the FPCN on a more granular level revealed reduced within-FPCN(A) connectivity only in patients displaying deficit features. FPCNB connectivity did not differ between patient groups. DISCUSSION: Here, we describe a neurobiological signature of aberrant FPCN connectivity in antipsychotic-naive, first-episode patients who display clinical features of the deficit syndrome. Importantly, frontoparietal subnetwork connectivity differentiated subgroups, where the FPCNA is selectively involved in patients with deficit features. Our findings add to the growing body of literature supporting a neurobiological distinction between two clinical subtypes of schizophrenia, which has the potential to be leveraged for patient stratification in clinical trials and the development of novel treatments.
Subject(s)
Antipsychotic Agents , Psychotic Disorders , Humans , Antipsychotic Agents/pharmacology , Psychotic Disorders/diagnostic imaging , Psychotic Disorders/drug therapy , Brain Mapping , Brain , Magnetic Resonance Imaging , Nerve Net/diagnostic imagingABSTRACT
INTRODUCTION: It is plausible that a longer duration of nutrition intervention may have a greater impact on clinical and patient-centred outcomes. The Intensive Nutrition care Therapy comparEd to usual care iN criTically ill adults (INTENT) trial will determine if a whole hospital nutrition intervention is feasible and will deliver more total energy compared with usual care in critically ill patients with at least one organ system failure. METHODS AND ANALYSIS: This study is a prospective, multicentre, unblinded, parallel-group, phase II randomised controlled trial (RCT) conducted in 23 hospitals in Australia and New Zealand. Mechanically ventilated critically ill adult patients with at least one organ failure who have been in intensive care unit (ICU) for 72-120 hours and meet all of the inclusion and none of the exclusion criteria will be randomised to receive either intensive or usual nutrition care. INTENT started recruitment in October 2018 and a sample size of 240 participants is anticipated to be recruited in 2022. The study period is from randomisation to hospital discharge or study day 28, whichever occurs first, and the primary outcome is daily energy delivery from nutrition therapy. Secondary outcomes include daily energy and protein delivery during ICU and in the post-ICU period, duration of ventilation, ventilator-free days, total bloodstream infection rate and length of hospital stay. All other outcomes are considered tertiary and results will be analysed on an intention-to-treat basis. ETHICS AND DISSEMINATION: Ethics approval has been received in Australia (Alfred Hospital Ethics Committee (HREC/18/Alfred/101) and Human Research Ethics Committee of the Northern Territory Department of Health (2019-3372)) and New Zealand (Northern A Health and Disability Ethics Committee (18/NTA/222). Results will be disseminated in an international peer-reviewed journal(s), at scientific meetings and via social media. TRIAL REGISTRATION NUMBER: NCT03292237.
Subject(s)
COVID-19 , Nutrition Therapy , Adult , Clinical Trials, Phase II as Topic , Critical Illness/therapy , Humans , Intensive Care Units , Multicenter Studies as Topic , Northern Territory , Randomized Controlled Trials as TopicABSTRACT
Diversity remains low among US colleges faculty, with only 3% identifying as Black or Hispanic. Moreover, underrepresented racial minority faculty often face unique challenges and are less likely than their white counterparts to earn higher academic rank, tenure, and funding, especially those who study health equity. We developed a novel program for health-equity focused pre-docs and junior faculty. The Disparities Researchers Equalizing Access for Minorities (DREAM) Scholars is a 24-month career development program led by the Center for Clinical and Translational Science (CCTS) that provides pilot and travel funding, career development seminars, mentoring, and writing retreats. We report the outcomes of the first Scholar cohort (N = 10), pre-docs n = 6; assistant professors, n = 4; seven were Black, one Hispanic, two White, one who identified as non-binary. At the end of the program, Scholars coauthored 34 manuscripts, 9 abstracts and 8 grants. Semi-structured interviews revealed seven major program strengths: funding, support and sense of community, accountability, exposure to translational science, network expansion, and exposure to multidisciplinary peers. Scholars provided feedback useful for subsequent cohorts. The DREAM program provided accountability and fostered a sense of community, expanded professional networks and enhanced scholarly productivity. The program serves as a model for implementation throughout the CCTSs.
ABSTRACT
Transcranial direct current stimulation (tDCS) on the dorsolateral prefrontal cortex (DLPFC) was used to improve foreign-langue learning while using mental imagery. Participants underwent two sessions of 1 mA, 1.5 mA, or sham stimulation prior to learning Swahili-English word pairs two consecutive days. During learning, participants were encouraged to create a mental image of the associated English word. Twenty-four hours after learning and one week later, participants received a cued recall test. A linear dose-response effect of stimulation was found across both tests that occurred long after the immediate effects of stimulation. Follow-up comparisons revealed that only the 1.5 mA condition differed from the sham group. Exploratory moderating effects revealed interactions with sleep quality and handedness. Those with poorer sleep and who were left-handed showed greater recall after 1.5 mA of stimulation than those with better sleep and right-handers. A follow-up behavioral study probing strategy usage indicated that mental imagery strategy use did not strongly impact learning but point to other possible mechanisms including the importance of attending to multimodal perceptual details and memory consolidation. This preliminary evidence supports the role of the DLPFC or connected regions in foreign language vocabulary learning and verbal memory encoding.
Subject(s)
Transcranial Direct Current Stimulation , Humans , Language , Mental Recall , Prefrontal Cortex , VocabularyABSTRACT
CTSI Career Development Award (KL2) programs provide junior faculty with protected time and multidisciplinary, mentored research training in clinical and translational science research. The KL2 Visiting Scholars Program was developed to promote collaborative cross-CTSA training, leverage academic strengths at host CTSAs, and support the career development of participating scholars through experiential training and the development of new partnerships. This manuscript provides a detailed programmatic description and reports outcomes from post-visit and outcomes surveys. Since 2016, 12 scholars have completed the program, with 6 scheduled to complete it in 2021. Post-visit surveys (n = 12) indicate all scholars reported the program valuable to career development, 11 reported benefit for research development, and 11 expansion of collaborative networks. Outcomes surveys (n = 11) revealed subsequent scholar interaction with host institution faculty for 10 scholars, 2 collaborative grant submissions (1 funded), 2 planned grant submissions, 1 published collaborative manuscript, and 3 planned manuscript/abstract submissions. The Visiting Scholars Program is a cost- and time-efficient program that leverages the academic strengths of CTSAs. The program enhanced KL2 scholar training by expanding their professional portfolio, promoting research development, and expanding collaborative networks. Resources to support the program are shared in this report to expedite the development of similar programs at regional and national levels.
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Angiotensin II (AngII) facilitates sympathetic neurotransmission by regulating norepinephrine (NE) synthesis, release and uptake. These effects of AngII contribute to cardiovascular control. Previous studies in our laboratory demonstrated that chronic AngII infusion decreased body weight of rats. We hypothesized that AngII facilitates sympathetic neurotransmission to adipose tissue and may thereby decrease body weight. The effect of chronic AngII infusion on the NE uptake transporter and NE turnover was examined in metabolic (interscapular brown adipose tissue, ISBAT; epididymal fat, EF) and cardiovascular tissues (left ventricle, LV; kidney) of rats. To examine the uptake transporter saturation isotherms were performed using [3H]nisoxetine (NIS). At doses that lowered body weight, AngII significantly increased ISBAT [3H]NIS binding density. To quantify NE turnover, alpha-methyl-para-tyrosine (AMPT) was injected in saline-infused, AngII-infused, or saline-infused rats that were pair-fed to food intake of AngII-infused rats. AngII significantly increased the rate of NE decline in all tissues compared to saline. The rate of NE decline in EF was increased to a similar extent by AngII and by pair-feeding. In rats administered AngII and propranolol, reductions in food and water intake and body weight were eliminated. These data support the hypothesis that AngII facilitates sympathetic neurotransmission to adipose tissue. Increased sympathetic neurotransmission to adipose tissue following AngII exposure is suggested to contribute to reductions in body weight.
ABSTRACT
OBJECTIVE: In murine models of obesity/diabetes, there is an increase in plasma serum amyloid A (SAA) levels along with redistribution of SAA from high-density lipoprotein (HDL) to apolipoprotein B (apoB)-containing lipoprotein particles, namely, low-density lipoprotein and very low-density lipoprotein. The goal of this study was to determine if obesity is associated with similar SAA lipoprotein redistribution in humans. DESIGN AND METHODS: Three groups of obese individuals were recruited from a weight loss clinic: healthy obese (n = 14), metabolic syndrome (MetS) obese (n = 8), and obese with type 2 diabetes (n = 6). Plasma was separated into lipoprotein fractions by fast protein liquid chromatography, and SAA was measured in lipid fractions using enzyme-linked immunosorbent assay and Western blotting. RESULTS: Only the obese diabetic group had SAA detectable in apoB-containing lipoproteins, and SAA reverted back to HDL with active weight loss. CONCLUSIONS: In human subjects, SAA is found in apoB-containing lipoprotein particles only in obese subjects with type 2 diabetes, but not in healthy obese or obese subjects with MetS.
Subject(s)
Apolipoproteins B/blood , Diabetes Mellitus, Type 2/blood , Lipoproteins/blood , Metabolic Syndrome/blood , Obesity/blood , Serum Amyloid A Protein/metabolism , Diabetes Mellitus, Type 2/complications , Humans , Lipoproteins, HDL/blood , Lipoproteins, LDL/blood , Lipoproteins, VLDL/blood , Metabolic Syndrome/complications , Obesity/complications , Weight LossABSTRACT
BACKGROUND: Despite numerous clinical and animal studies, the role of sex steroid hormones on lipoprotein metabolism and atherosclerosis remain controversial. OBJECTIVE: We sought to determine the effects of endogenous estrogen and testosterone on lipoprotein levels and atherosclerosis using mice fed a low-fat diet with no added cholesterol. METHODS: Male and female low-density lipoprotein receptor-deficient mice were fed an open stock low-fat diet (10% of kcals from fat) for 2, 4, or 17 weeks. Ovariectomy, orchidectomy, or sham surgeries were performed to evaluate the effects of the presence or absence of endogenous hormones on lipid levels, lipoprotein distribution, and atherosclerosis development. RESULTS: Female mice fed the study diet for 17 weeks had a marked increase in levels of total cholesterol, triglycerides, apolipoprotein-B containing lipoproteins, and atherosclerosis compared with male mice. Surprisingly, ovariectomy in female mice had no effect on any of these parameters. In contrast, castration of male mice markedly increased total cholesterol concentrations, triglycerides, apolipoprotein B-containing lipoproteins, and atherosclerotic lesion formation compared with male and female mice. CONCLUSIONS: These data suggest that endogenous androgens protect against diet-induced increases in cholesterol concentrations, formation of proatherogenic lipoproteins, and atherosclerotic lesions formation. Conversely orchidectomy, which decreases androgen concentrations, promotes increases in cholesterol concentrations, proatherogenic lipoprotein formation, and atherosclerotic lesion formation in low-density lipoprotein receptor-deficient mice in response to a low-fat diet.
Subject(s)
Androgens/metabolism , Atherosclerosis/metabolism , Hypercholesterolemia/metabolism , Hyperlipoproteinemia Type II/metabolism , Lipids/blood , Lipoproteins, LDL/blood , Animals , Diet, Fat-Restricted , Female , Male , Mice , Receptors, LDL/genetics , Sex FactorsABSTRACT
PURPOSE OF REVIEW: Serum amyloid A (SAA) is a family of acute-phase proteins which are shown to correlate with cardiovascular disease, but whether this SAA contributes causally to atherosclerosis development or reflects underlying disease or risk factors remains unclear. RECENT FINDINGS: SAA has been detected within atherosclerotic lesions and within adipose tissue where it is hypothesized that it may play a contributory role in disease development. In the acute-phase response SAA is synthesized by the liver and transported primarily in association with HDL. However, there is a growing literature suggesting that localized synthesis of SAA within the vasculature, or adipose tissue, may play a distinct role in disease development. Furthermore, SAA can be found in association with apoB-containing lipoproteins, in which its biological activity may be different. SUMMARY: This review will discuss recent experimental evidence supporting a causal role of SAA with atherosclerosis.
Subject(s)
Atherosclerosis/metabolism , Serum Amyloid A Protein/metabolism , Animals , Atherosclerosis/physiopathology , Humans , Lipoproteins, LDL/metabolism , Liver/metabolism , Obesity/metabolism , Proteoglycans/metabolismSubject(s)
Atherosclerosis , Disease Models, Animal , Animals , Atherosclerosis/blood , Atherosclerosis/etiology , Atherosclerosis/pathology , Biomarkers/blood , Cholesterol Ester Transfer Proteins/blood , Cholesterol, Dietary/blood , Cholesterol, HDL/blood , Cholesterol, LDL/blood , Cholesterol, VLDL/blood , Humans , Mice , Octodon , Palm Oil , Plant Oils , Reproducibility of ResultsABSTRACT
The metabolic syndrome (MetS) is characterized by obesity concomitant with other metabolic abnormalities such as hypertriglyceridemia, reduced high-density lipoprotein levels, elevated blood pressure and raised fasting glucose levels. The precise definition of MetS, the relationships of its metabolic features, and what initiates it, are debated. However, obesity is on the rise worldwide, and its association with these metabolic symptoms increases the risk for diabetes and cardiovascular disease (among many other diseases). Research needs to determine the mechanisms by which obesity and MetS increase the risk of disease. In light of this growing epidemic, it is imperative to develop animal models of MetS. These models will help determine the pathophysiological basis for MetS and how MetS increases the risk for other diseases. Among the various animal models available to study MetS, mice are the most commonly used for several reasons. First, there are several spontaneously occurring obese mouse strains that have been used for decades and that are very well characterized. Second, high-fat feeding studies require only months to induce MetS. Third, it is relatively easy to study the effects of single genes by developing transgenic or gene knockouts to determine the influence of a gene on MetS. For these reasons, this review will focus on the benefits and caveats of the most common mouse models of MetS. It is our hope that the reader will be able to use this review as a guide for the selection of mouse models for their own studies.
Subject(s)
Disease Models, Animal , Metabolic Syndrome/pathology , Animals , Humans , Hyperlipidemias/complications , Hyperlipidemias/pathology , Hypertension/complications , Hypertension/pathology , Insulin Resistance , Metabolic Syndrome/complications , Mice , Obesity/complications , Obesity/pathologyABSTRACT
The epidemic of obesity sweeping developed nations is accompanied by an increase in atherosclerotic cardiovascular diseases. Dyslipidemia, diabetes, hypertension, and obesity are risk factors for cardiovascular disease. However, delineating the mechanism of obesity-accelerated atherosclerosis has been hampered by a paucity of animal models. Similar to humans, apolipoprotein E-deficient (apoE(-/-)) mice spontaneously develop atherosclerosis over their lifetime. To determine whether apoE(-/-) mice would develop obesity with accelerated atherosclerosis, we fed mice diets containing 10 (low fat (LF)) or 60 (high fat (HF)) kcal % from fat for 17 weeks. Mice fed the HF diet had a marked increase in body weight and atherosclerotic lesion formation compared to mice fed the LF diet. There were no significant differences between groups in serum total cholesterol, triglycerides, or leptin concentrations. Plasma concentrations of the acute-phase reactant serum amyloid A (SAA) are elevated in both obesity and cardiovascular disease. Accordingly, plasma SAA concentrations were increased fourfold (P < 0.01) in mice fed the HF diet. SAA was associated with both pro- and antiatherogenic lipoproteins in mice fed the HF diet compared to those fed the LF diet, in which SAA was primarily associated with the antiatherogenic lipoprotein high-density lipoprotein (HDL). Moreover, SAA was localized with apoB-containing lipoproteins and biglycan in the vascular wall. Taken together, these data suggest male apoE-deficient mice are a model of metabolic syndrome and that chronic low level inflammation associated with increased SAA concentrations may mediate atherosclerotic lesion formation.
Subject(s)
Apolipoproteins E/genetics , Atherosclerosis/genetics , Body Weight/genetics , Diet , Obesity/genetics , Adiponectin/blood , Analysis of Variance , Animals , Apolipoproteins E/metabolism , Atherosclerosis/metabolism , Blood Glucose/metabolism , Blotting, Western , Chemokine CCL2/blood , Chromatography, High Pressure Liquid , Dietary Fats , Disease Progression , Energy Intake/genetics , Enzyme-Linked Immunosorbent Assay , Image Processing, Computer-Assisted , Interleukin-6/blood , Leptin/blood , Lipids/blood , Liver/metabolism , Male , Mice , Mice, Knockout , Obesity/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Tumor Necrosis Factor-alpha/bloodSubject(s)
Atherosclerosis/etiology , Tumor Necrosis Factors/physiology , Animals , Apolipoproteins E/deficiency , Apolipoproteins E/genetics , Atherosclerosis/pathology , Atherosclerosis/physiopathology , Cytokine TWEAK , Humans , Mice , Mice, Knockout , Receptors, Tumor Necrosis Factor/physiology , Recombinant Proteins/pharmacology , Signal Transduction , TWEAK Receptor , Tumor Necrosis Factor Inhibitors , Tumor Necrosis Factors/pharmacologyABSTRACT
BACKGROUND: Vascular disease can manifest as stenotic plaques or ectatic aneurysms, although the mechanisms culminating in these divergent disease manifestations remain poorly understood. T-helper type 1 cytokines, including interferon-gamma and CXCL10, have been strongly implicated in atherosclerotic plaque development. METHODS AND RESULTS: Here, we specifically examined their role in the formation of abdominal aortic aneurysms in the angiotensin II-induced murine model. Unexpectedly, we found increased suprarenal aortic diameters, abdominal aortic aneurysm incidence, and aneurysmal death in apolipoprotein E- and interferon-gamma-deficient (Apoe(-/-)/Ifng(-/-)) mice compared with Apoe(-/-) controls, although atherosclerotic luminal plaque formation was attenuated. The interferon-gamma-inducible T-cell chemoattractant CXCL10 was highly induced by angiotensin II infusion in Apoe(-/-) mice, but this induction was markedly attenuated in Apoe(-/-)/Ifng(-/-) mice. Apoe(-/-)/Cxcl10(-/-) mice had decreased luminal plaque but also increased aortic size, worse morphological grades of aneurysms, and a higher incidence of death due to aortic rupture than Apoe(-/-) controls. Furthermore, abdominal aortic aneurysms in Apoe(-/-)/Cxcl10(-/-) mice were enriched for non-T-helper type 1-related signals, including transforming growth factor-beta1. Treatment of Apoe(-/-)/Cxcl10(-/-) mice with anti-transforming growth factor-beta neutralizing antibody diminished angiotensin II-induced aortic dilation. CONCLUSIONS: The present study defines a novel pathway in which interferon-gamma and its effector, CXCL10, contribute to divergent pathways in abdominal aortic aneurysm versus plaque formation, inhibiting the former pathology but promoting the latter. Thus, efforts to develop antiinflammatory strategies for atherosclerosis must carefully consider potential effects on all manifestations of vascular disease.
Subject(s)
Aortic Aneurysm, Abdominal/prevention & control , Aortic Rupture/prevention & control , Cardiotonic Agents/metabolism , Chemokine CXCL10/physiology , Interferon-gamma/physiology , Animals , Aortic Aneurysm, Abdominal/genetics , Aortic Aneurysm, Abdominal/metabolism , Aortic Aneurysm, Abdominal/pathology , Aortic Rupture/genetics , Aortic Rupture/metabolism , Aortic Rupture/pathology , Atherosclerosis/metabolism , Atherosclerosis/pathology , Mice , Mice, Inbred C57BL , Mice, KnockoutABSTRACT
Inflammatory markers serum amyloid A (SAA) and C-reactive protein (CRP) are predictive of cardiac disease and are proposed to play causal roles in the development of atherosclerosis, in which the retention of lipoproteins by vascular wall proteoglycans is critical. The purpose of this study was to determine whether SAA and/or CRP alters vascular proteoglycan synthesis and lipoprotein retention in a pro-atherogenic manner. Vascular smooth muscle cells were stimulated with either SAA or CRP (1 to 100 mg/L) and proteoglycans were then isolated and characterized. SAA, but not CRP, increased proteoglycan sulfate incorporation by 50 to 100% in a dose-dependent manner (P < 0.0001), increased glycosaminoglycan chain length, and increased low-density lipoprotein (LDL) binding affinity (K(d), 29 microg/ml LDL versus 90 microg/ml LDL for SAA versus control proteoglycans; P < 0.005). Furthermore, SAA up-regulated biglycan via the induction of endogenous transforming growth factor (TGF)-beta. To determine whether SAA stimulated proteoglycan synthesis in vivo, ApoE(-/-) mice were injected with an adenovirus expressing human SAA-1, a null virus, or saline. Mice that received adenovirus expressing SAA had increased TGF-beta concentrations in plasma and increased aortic biglycan content compared with mice that received either null virus or saline. Thus, SAA alters vascular proteoglycans in a pro-atherogenic manner via the stimulation of TGF-beta and may play a causal role in the development of atherosclerosis.
Subject(s)
Atherosclerosis/metabolism , C-Reactive Protein/metabolism , Proteoglycans/metabolism , Serum Amyloid A Protein/metabolism , Animals , Aorta/metabolism , Apolipoproteins E/genetics , Apolipoproteins E/metabolism , Biglycan , Cells, Cultured , Extracellular Matrix Proteins/metabolism , Glycosaminoglycans/chemistry , Glycosaminoglycans/metabolism , Haplorhini , Humans , Lipoproteins, LDL/metabolism , Male , Mice , Mice, Knockout , Muscle, Smooth, Vascular/cytology , Myocytes, Smooth Muscle/cytology , Myocytes, Smooth Muscle/metabolism , Proteoglycans/chemistry , Receptors, Formyl Peptide/genetics , Receptors, Formyl Peptide/metabolism , Receptors, Lipoxin/genetics , Receptors, Lipoxin/metabolism , Transforming Growth Factor beta/metabolismABSTRACT
The response to retention hypothesis outlines the initial stages of atherosclerotic lesion formation. The central theme of the hypothesis is that proteoglycan mediated lipoprotein retention plays a critical step in the initiation of atherosclerosis development. Recent research using human arterial specimens, transgenic mouse models and molecular biology techniques have added to our understanding of atherosclerosis development, and provided experimental data in support of the response to retention hypothesis. In this review we summarize the recent data, in particular that which addresses mechanisms by which diabetes can accelerate atherosclerosis formation, with a focus on proteoglycan-mediated LDL retention.
Subject(s)
Atherosclerosis/pathology , Diabetic Angiopathies/etiology , Lipoproteins, LDL/metabolism , Proteoglycans/metabolism , Animals , Atherosclerosis/etiology , Decorin , Diabetic Angiopathies/physiopathology , Disease Progression , Extracellular Matrix Proteins/metabolism , Heparan Sulfate Proteoglycans/biosynthesis , Humans , Macrophages/physiology , Mice , Muscle, Smooth, Vascular/physiopathologyABSTRACT
Interleukin-4 (IL-4) has been detected in both human and mouse atherosclerotic lesions, although its effects on the development of the disease are undefined. We determined the role of IL-4 in the most commonly used murine models of atherosclerosis by defining the effects of exogenous delivery and genetic deficiency of this cytokine on both hypercholesterolemia and AngII-induced atherosclerosis in apolipoprotein E (apoE)(-/-) mice and different dietary stimuli in low-density lipoprotein (LDL) receptor(-/-) mice. Exogenous administration of IL-4 (1.1 ng g(-1) day(-1) i.p. for 30 days) into female apoE(-/-) mice had no effect on lesion size or composition in mice fed normal or saturated fat diets. Also, IL-4 deficiency had no significant effect on the size or composition of atherosclerotic lesions in two vascular areas of male and female apoE(-/-) mice fed either a normal or saturated fat diet. IL-4 deficiency was also studied in age-matched male mice infused with AngII (1000 ng kg(-1) min(-1)) for 28 days. Whereas AngII infusion augmented atherosclerotic lesion formation, IL-4 deficiency did not influence atherosclerotic lesion size or composition. Finally, different dietary stimuli also had no effect on atherosclerotic lesion size in female LDL receptor(-/-) mice. These data demonstrate that IL-4 does not significantly influence the development of atherosclerotic lesions in apoE(-/-) mice of either gender or in female LDL receptor(-/-) mice, irrespective of the mode of induction of atherosclerosis.
Subject(s)
Atherosclerosis/metabolism , Atherosclerosis/pathology , Hypercholesterolemia/metabolism , Interleukin-4/metabolism , Angiotensin II/administration & dosage , Angiotensin II/toxicity , Animals , Apolipoproteins E/genetics , Atherosclerosis/chemically induced , Disease Models, Animal , Female , Interleukin-4/pharmacology , Male , Mice , Mice, Mutant Strains , Receptors, LDL/geneticsABSTRACT
Glucosamine, commonly consumed for the treatment of osteoarthritis, is classified as a nutritional supplement; however, there are few data regarding its metabolic or vascular effects. Glucosamine is a component of the hexosamine pathway, which has been implicated in the development of insulin resistance. Anecdotal reports suggest that glucosamine consumption can increase circulating cholesterol concentrations. To investigate the metabolic and vascular effects of glucosamine supplementation, we studied male and female LDL receptor-deficient mice fed a Western diet (21% fat, 0.15% cholesterol). Three groups of 6-10 mice of each gender received either no supplement, 15 mg . kg(-1) . d(-1) glucosamine (equivalent to an average human dose), or 50 mg . kg(-1) . d(-1) glucosamine added to their drinking water for 5, 10, or 20 wk. Plasma cholesterol and triglyceride concentrations increased in all mice with the addition of the Western diet. However, after 20 wk of treatment, cholesterol and triglyceride concentrations increased further in male mice consuming glucosamine compared with control groups. Glucosamine-supplemented mice had increased initiation of atherosclerosis after 5 wk; however, there was no effect on progression of atherosclerosis in either gender after longer periods of glucosamine supplementation (10 or 20 wk). Although long-term glucosamine supplementation exacerbated the hyperlipidemia in male mice, no increase in atherosclerosis occurred. Thus, glucosamine supplementation appears to be safe, with no adverse vascular consequences.