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Role of L-Arginine in Nitric Oxide Synthesis and Health in Humans. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1332:167-187. [PMID: 34251644 DOI: 10.1007/978-3-030-74180-8_10] [Citation(s) in RCA: 66] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
As a functional amino acid (AA), L-arginine (Arg) serves not only as a building block of protein but also as an essential substrate for the synthesis of nitric oxide (NO), creatine, polyamines, homoarginine, and agmatine in mammals (including humans). NO (a major vasodilator) increases blood flow to tissues. Arg and its metabolites play important roles in metabolism and physiology. Arg is required to maintain the urea cycle in the active state to detoxify ammonia. This AA also activates cellular mechanistic target of rapamycin (MTOR) and focal adhesion kinase cell signaling pathways in mammals, thereby stimulating protein synthesis, inhibiting autophagy and proteolysis, enhancing cell migration and wound healing, promoting spermatogenesis and sperm quality, improving conceptus survival and growth, and augmenting the production of milk proteins. Although Arg is formed de novo from glutamine/glutamate and proline in humans, these synthetic pathways do not provide sufficient Arg in infants or adults. Thus, humans and other animals do have dietary needs of Arg for optimal growth, development, lactation, and fertility. Much evidence shows that oral administration of Arg within the physiological range can confer health benefits to both men and women by increasing NO synthesis and thus blood flow in tissues (e.g., skeletal muscle and the corpora cavernosa of the penis). NO is a vasodilator, a neurotransmitter, a regulator of nutrient metabolism, and a killer of bacteria, fungi, parasites, and viruses [including coronaviruses, such as SARS-CoV and SARS-CoV-2 (the virus causing COVID-19). Thus, Arg supplementation can enhance immunity, anti-infectious, and anti-oxidative responses, fertility, wound healing, ammonia detoxification, nutrient digestion and absorption, lean tissue mass, and brown adipose tissue development; ameliorate metabolic syndromes (including dyslipidemia, obesity, diabetes, and hypertension); and treat individuals with erectile dysfunction, sickle cell disease, muscular dystrophy, and pre-eclampsia.
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Breton CV, Mack WJ, Yao J, Berhane K, Amadeus M, Lurmann F, Gilliland F, McConnell R, Hodis HN, Künzli N, Avol E. Prenatal Air Pollution Exposure and Early Cardiovascular Phenotypes in Young Adults. PLoS One 2016; 11:e0150825. [PMID: 26950592 PMCID: PMC4780745 DOI: 10.1371/journal.pone.0150825] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 02/20/2016] [Indexed: 01/11/2023] Open
Abstract
Exposure to ambient air pollutants increases risk for adverse cardiovascular health outcomes in adults. We aimed to evaluate the contribution of prenatal air pollutant exposure to cardiovascular health, which has not been thoroughly evaluated. The Testing Responses on Youth (TROY) study consists of 768 college students recruited from the University of Southern California in 2007–2009. Participants attended one study visit during which blood pressure, heart rate and carotid artery arterial stiffness (CAS) and carotid artery intima-media thickness (CIMT) were assessed. Prenatal residential addresses were geocoded and used to assign prenatal and postnatal air pollutant exposure estimates using the U.S. Environmental Protection Agency’s Air Quality System (AQS) database. The associations between CAS, CIMT and air pollutants were assessed using linear regression analysis. Prenatal PM10 and PM2.5 exposures were associated with increased CAS. For example, a 2 SD increase in prenatal PM2.5 was associated with CAS indices, including a 5% increase (β = 1.05, 95% CI 1.00–1.10) in carotid stiffness index beta, a 5% increase (β = 1.05, 95% CI 1.01–1.10) in Young’s elastic modulus and a 5% decrease (β = 0.95, 95% CI 0.91–0.99) in distensibility. Mutually adjusted models of pre- and postnatal PM2.5 further suggested the prenatal exposure was most relevant exposure period for CAS. No associations were observed for CIMT. In conclusion, prenatal exposure to elevated air pollutants may increase carotid arterial stiffness in a young adult population of college students. Efforts aimed at limiting prenatal exposures are important public health goals.
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Affiliation(s)
- Carrie V Breton
- University of Southern California, Dept of Preventive Medicine, 2001 N Soto St., Los Angeles, California, 90089, United States of America
| | - Wendy J Mack
- University of Southern California, Dept of Preventive Medicine, 2001 N Soto St., Los Angeles, California, 90089, United States of America.,University of Southern California, Atherosclerosis Research Unit, 2250 Alcazar Street, CSC 132, Los Angeles, California, 90033, United States of America
| | - Jin Yao
- University of Southern California, Dept of Preventive Medicine, 2001 N Soto St., Los Angeles, California, 90089, United States of America
| | - Kiros Berhane
- University of Southern California, Dept of Preventive Medicine, 2001 N Soto St., Los Angeles, California, 90089, United States of America
| | - Milena Amadeus
- University of Southern California, Dept of Preventive Medicine, 2001 N Soto St., Los Angeles, California, 90089, United States of America
| | - Fred Lurmann
- Sonoma Technology Inc., 1455 N. McDowell Blvd., Suite D, Petaluma, California, 94954-6503, United States of America
| | - Frank Gilliland
- University of Southern California, Dept of Preventive Medicine, 2001 N Soto St., Los Angeles, California, 90089, United States of America
| | - Rob McConnell
- University of Southern California, Dept of Preventive Medicine, 2001 N Soto St., Los Angeles, California, 90089, United States of America
| | - Howard N Hodis
- University of Southern California, Dept of Preventive Medicine, 2001 N Soto St., Los Angeles, California, 90089, United States of America.,University of Southern California, Atherosclerosis Research Unit, 2250 Alcazar Street, CSC 132, Los Angeles, California, 90033, United States of America
| | - Nino Künzli
- Swiss Tropical and Public Health Institute, Socinstr. 57, P.O. Box, 4002 Basel, Switzerland.,University of Basel, Petersplatz 1 CH-4003 Basel, Switzerland
| | - Ed Avol
- University of Southern California, Dept of Preventive Medicine, 2001 N Soto St., Los Angeles, California, 90089, United States of America
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DNA methylation biomarkers: cancer and beyond. Genes (Basel) 2014; 5:821-64. [PMID: 25229548 PMCID: PMC4198933 DOI: 10.3390/genes5030821] [Citation(s) in RCA: 173] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2014] [Revised: 08/17/2014] [Accepted: 09/01/2014] [Indexed: 12/23/2022] Open
Abstract
Biomarkers are naturally-occurring characteristics by which a particular pathological process or disease can be identified or monitored. They can reflect past environmental exposures, predict disease onset or course, or determine a patient's response to therapy. Epigenetic changes are such characteristics, with most epigenetic biomarkers discovered to date based on the epigenetic mark of DNA methylation. Many tissue types are suitable for the discovery of DNA methylation biomarkers including cell-based samples such as blood and tumor material and cell-free DNA samples such as plasma. DNA methylation biomarkers with diagnostic, prognostic and predictive power are already in clinical trials or in a clinical setting for cancer. Outside cancer, strong evidence that complex disease originates in early life is opening up exciting new avenues for the detection of DNA methylation biomarkers for adverse early life environment and for estimation of future disease risk. However, there are a number of limitations to overcome before such biomarkers reach the clinic. Nevertheless, DNA methylation biomarkers have great potential to contribute to personalized medicine throughout life. We review the current state of play for DNA methylation biomarkers, discuss the barriers that must be crossed on the way to implementation in a clinical setting, and predict their future use for human disease.
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Bruzzi P, Predieri B, Patianna VD, Salvini A, Rossi R, Modena MG, Iughetti L. Longitudinal evaluation of endothelial function in children and adolescents with type 1 diabetes mellitus: a long-term follow-up study. Pediatr Int 2014; 56:188-95. [PMID: 24020908 DOI: 10.1111/ped.12220] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Revised: 07/02/2013] [Accepted: 09/03/2013] [Indexed: 12/13/2022]
Abstract
BACKGROUND Type 1 diabetes (T1DM) predisposes to cardiovascular disease, increasing the risk to develop atherosclerosis. In the pediatric population, the cardiovascular risk may be evaluated examining endothelial function by a non-invasive ultrasound technique, namely flow-mediated dilation (FMD) of the brachial artery. The aims of this study were the longitudinal evaluation of the potential change in the endothelium-dependent vasomotor function in children and adolescents with T1DM and the identification of clinical and laboratory data correlated to modifications. METHODS We studied 39 T1DM patients (20 girls and 19 boys; aged 11.2 ± 3.72 years). FMD and blood samples were obtained from all patients at baseline (time 0) and after a follow up of at least 1 year (time 1). FMD was also evaluated in 45 healthy controls (22 boys, 23 girls) aged 10.2 ± 3.05 years. RESULTS At time 0, 43.6% of T1DM patients presented an impaired FMD. FMD at time 1 revealed a dramatic impairment of endothelial function: altered FMD values were shown in 61.5% of patients and it got worse in 74.3% of them. Longitudinally, boys had a greater impairment of FMD than girls. At baseline, multivariate analysis identified only sex as significant predictor of FMD (β = 0.470, P = 0.029). CONCLUSIONS Because endothelial dysfunction appears earlier in diabetic children, they are at higher risk to develop atherosclerosis. Our results suggest the usefulness of FMD as a tool to stratify pediatric T1DM patients according to their cardiovascular risk and to follow them up longitudinally.
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Affiliation(s)
- Patrizia Bruzzi
- Department of Pediatrics, University of Modena and Reggio Emilia, Modena, Italy
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Effects of early-life environment and epigenetics on cardiovascular disease risk in children: highlighting the role of twin studies. Pediatr Res 2013; 73:523-30. [PMID: 23314296 DOI: 10.1038/pr.2013.6] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Cardiovascular disease (CVD) is the leading cause of death worldwide and originates in early life. The exact mechanisms of this early-life origin are unclear, but a likely mediator at the molecular level is epigenetic dysregulation of gene expression. Epigenetic factors have thus been posited as the likely drivers of early-life programming of adult-onset diseases. This review summarizes recent advances in epidemiology and epigenetic research of CVD risk in children, with a particular focus on twin studies. Classic twin studies enable partitioning of phenotypic variance within a population into additive genetic, shared, and nonshared environmental variances, and are invaluable in research in this area. Longitudinal cohort twin studies, in particular, may provide important insights into the role of epigenetics in the pathogenesis of CVD. We describe candidate gene and epigenome-wide association studies (EWASs) and transgenerational epigenetic inheritance of CVD, and discuss the potential for evidence-based interventions. Identifying epigenetic changes associated with CVD-risk biomarkers in children will provide new opportunities to unravel the underlying biological mechanism of the origins of CVD and enable identification of those at risk for early-life interventions to alter the risk trajectory and potentially reduce CVD incidence later in life.
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Agostoni C, Baselli L, Mazzoni MB. Early nutrition patterns and diseases of adulthood: a plausible link? Eur J Intern Med 2013; 24:5-10. [PMID: 22981292 DOI: 10.1016/j.ejim.2012.08.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Revised: 08/20/2012] [Accepted: 08/24/2012] [Indexed: 12/13/2022]
Abstract
In the last decades several studies tested the hypothesis that at early development stages certain foods or nutrients, in specific amounts, fed during limited sensitive periods, may determine an endocrine metabolic asset leading to clinical alterations that take place decades later (early nutritional programming of long term health). Evidence is mounting for programming effects of infant feeding. Observational studies indicate that breast feeding, relative to formula feeding, reduces the risk for obesity at school age by about 20% even after adjustment for biological and sociodemographic confounders. Moreover, breastfeeding is constantly associated with increased neurodevelopmental scores up to early adulthood, while its outcome in terms of delayed decay of brain function is still unknown. Besides the environment surrounding breastfeeding, specific nutrients within human milk may play a direct role. With the introduction of solids the major changes in diet are represented by the sudden decrease of fat intake from 50 to 30% of total energy. A protein excess, commonly found throughout all European Countries, has been associated to a higher risk of adiposity in early childhood, as confirmed by first reports from a large European trial. The amount of fat does not seem to be associated with later adiposity, while its quality may affect blood lipoproteins, blood pressure and neurodevelopmental performance. Early intake of dietary fibers might also have beneficial effects. Epidemiologic data show that episodes of rapid growth (growth acceleration hypothesis), whichever the dietary habits, are associated with later unfavorable health conditions and should be prevented.
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Affiliation(s)
- Carlo Agostoni
- Pediatric Clinic 2, Fondazione IRCCS Cà Granda - Ospedale Maggiore Policlinico, Department of Clinical Sciences and Community Health, University of Milan, Italy.
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Barbosa JAA, Rodrigues AB, Mota CCC, Barbosa MM, Simões e Silva AC. Cardiovascular dysfunction in obesity and new diagnostic imaging techniques: the role of noninvasive image methods. Vasc Health Risk Manag 2011; 7:287-95. [PMID: 21633726 PMCID: PMC3104606 DOI: 10.2147/vhrm.s17801] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Indexed: 12/19/2022] Open
Abstract
Obesity is a major public health problem affecting adults and children in both developed and developing countries. This condition often leads to metabolic syndrome, which increases the risk of cardiovascular disease. A large number of studies have been carried out to understand the pathogenesis of cardiovascular dysfunction in obese patients. Endothelial dysfunction plays a key role in the progression of atherosclerosis and the development of coronary artery disease, hypertension and congestive heart failure. Noninvasive methods in the field of cardiovascular imaging, such as measuring intima-media thickness, flow-mediated dilatation, tissue Doppler, and strain, and strain rate, constitute new tools for the early detection of cardiac and vascular dysfunction. These techniques will certainly enable a better evaluation of initial cardiovascular injury and allow the correct, timely management of obese patients. The present review summarizes the main aspects of cardiovascular dysfunction in obesity and discusses the application of recent noninvasive imaging methods for the early detection of cardiovascular alterations.
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Affiliation(s)
- José Augusto A Barbosa
- Department of Pediatrics, Faculty of Medicine, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
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Law JR, Patel S, Spagnoli A. Approach to lipid screening as a risk marker for cardiovascular disease in pediatric patients with diabetes. Front Endocrinol (Lausanne) 2011; 2:47. [PMID: 22649373 PMCID: PMC3355998 DOI: 10.3389/fendo.2011.00047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2011] [Accepted: 09/17/2011] [Indexed: 12/02/2022] Open
Abstract
Cardiovascular disease (CVD) is a well-known complication of diabetes mellitus (DM), and patients with DM are at an increased risk for early onset of CVD. Hyperglycemia is believed to be the primary mediator in premature development of atherosclerosis in patients with DM, but there are also derangements in cholesterol levels and inflammatory markers beyond the explanation of hyperglycemia. Although clinicians often screen for dyslipidemia as part of routine care for children and adolescents with DM, many do not feel comfortable treating this condition. Multiple guidelines exist to help clinicians with the prevention, screening, and treatment of CVD risk factors in pediatric patients with DM, but the guidelines do not always agree on screening intervals or medical treatment. Furthermore, the cost-effectiveness of medication use in this population has not been established. Research has advanced our understanding of the role of other biomarkers and radiologic studies of CVD risk, but these studies do not currently have a place in routine clinical practice. It is evident that the increased CVD risk in pediatric patients with DM is complex in origin and the optimal approach to managing dyslipidemia remains unclear. Therefore, an algorithm designed at the University of North Carolina (UNC), Division of Pediatric Endocrinology, is presented to help guide clinicians through screening and treatment of dyslipidemia in youth with DM.
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Affiliation(s)
- Jennifer Rachel Law
- Division of Pediatric Endocrinology, Department of Pediatrics, University of North Carolina at Chapel HillChapel Hill, NC, USA
| | - Shipra Patel
- Division of Pediatric Endocrinology, Department of Pediatrics, University of North Carolina at Chapel HillChapel Hill, NC, USA
| | - Anna Spagnoli
- Division of Pediatric Endocrinology, Department of Pediatrics, University of North Carolina at Chapel HillChapel Hill, NC, USA
- *Correspondence: Anna Spagnoli, Division of Pediatric Endocrinology, University of North Carolina, 111 Mason Farm Road, CB 7039, Chapel Hill, NC 27599-7039, USA. e-mail:
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Hypercholesterolemia in Youth: Opportunities and Obstacles to Prevent Premature Atherosclerotic Cardiovascular Disease. Curr Atheroscler Rep 2010; 12:20-8. [DOI: 10.1007/s11883-009-0072-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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