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1.
Occup Ther Health Care ; 37(4): 606-626, 2023 Oct.
Article in English | MEDLINE | ID: mdl-35341462

ABSTRACT

INTRODUCTION: This scoping review explores the professional literature in allied healthcare to determine which self-assessments of mentor skills are the most valid and reliable for use in occupational therapy doctoral capstone programs. The aims of this scoping review include mapping evidence related to mentor assessments in healthcare, exploring implications for occupational therapy doctoral mentor training programs, and identifying common characteristics of mentor self-assessments for occupational therapy programs to consider when developing capstone mentoring resources. METHODS: Researchers applied and reported via PRISMA Extension for Scoping Reviews (PRISMA-ScR). A librarian and authors formulated keywords and database selections to search PubMed/MEDLINE/PMC, and Embase were searched from across healthcare professions for training outcomes, mentor self-assessment, mentor attributes, and use of researcher-developed assessments. The search was limited to English publications from the last 20 years. Data were extracted for quantitative information regarding study characteristics and qualitative information about mentoring skills. RESULTS: A total of 852 results were delivered across all databases. Nineteen papers met the final eligibility criteria and were included in the data extraction. Populations were included from several healthcare professions, including 11 nursing, four healthcare researchers, one pharmacy, one midwifery, one medicine, and one medical dietetics. Countries included the United States (n = 7), Finland (n = 5), United Kingdom (n = 4), Japan (n = 1), South Africa (n = 1) and Canada (n = 1). CONCLUSION: The authors identified four valid self-assessment tools, demonstrating III and IV levels of evidence, that may be implemented by occupational therapy programs as they develop resources for mentor programs. Occupational therapy programs can use the mentor attributes found in this scoping review to create their own mentor assessment measures or may choose to use a validated tool. The authors recommend additional research in mentor education and mentor skill acquisition.


Subject(s)
Mentoring , Occupational Therapy , Humans , Mentors/education , Self-Assessment , Occupational Therapy/education , Delivery of Health Care
2.
J Virol Methods ; 289: 114048, 2021 03.
Article in English | MEDLINE | ID: mdl-33358911

ABSTRACT

We describe the optimisation of a simplified sample preparation method which permits rapid and direct detection of SARS-CoV-2 RNA within saliva, using reverse-transcription loop-mediated isothermal amplification (RT-LAMP). Treatment of saliva samples prior to RT-LAMP by dilution 1:1 in Mucolyse™, followed by dilution in 10 % (w/v) Chelex© 100 Resin and a 98 °C heat step for 2 min enabled detection of SARS-CoV-2 RNA in positive saliva samples. Using RT-LAMP, SARS-CoV-2 RNA was detected in as little as 05:43 min, with no amplification detected in 3097 real-time reverse transcription PCR (rRT-PCR) negative saliva samples from staff tested within a service evaluation study, or for other respiratory pathogens tested (n = 22). Saliva samples can be collected non-invasively, without the need for skilled staff and can be obtained from both healthcare and home settings. Critically, this approach overcomes the requirement for, and validation of, different swabs and the global bottleneck in obtaining access to extraction robots and reagents to enable molecular testing by rRT-PCR. Such testing opens the possibility of public health approaches for effective intervention during the COVID-19 pandemic through regular SARS-CoV-2 testing at a population scale, combined with isolation and contact tracing.


Subject(s)
COVID-19 Testing/methods , COVID-19/diagnosis , Molecular Diagnostic Techniques/methods , Nucleic Acid Amplification Techniques/methods , SARS-CoV-2/isolation & purification , Saliva/virology , Specimen Handling/methods , Humans , RNA, Viral/analysis
3.
Int J Obes (Lond) ; 43(5): 974-988, 2019 05.
Article in English | MEDLINE | ID: mdl-30622309

ABSTRACT

BACKGROUND: The early life environment may influence susceptibility to obesity and metabolic disease in later life through epigenetic processes. SLC6A4 is an important mediator of serotonin bioavailability, and has a key role in energy balance. We tested the hypothesis that methylation of the SLC6A4 gene predicts adiposity across the life course. METHODS: DNA methylation at 5 CpGs within the SLC6A4 gene identified from a previous methyl binding domain array was measured by pyrosequencing. We measured DNA methylation in umbilical cord (UC) from children in the Southampton Women's Survey cohort (n = 680), in peripheral blood from adolescents in the Western Australian Pregnancy Cohort Study (n = 812), and in adipose tissue from lean and obese adults from the UK BIOCLAIMS cohort (n = 81). Real-time PCR was performed to assess whether there were corresponding alterations in gene expression in the adipose tissue. RESULTS: Lower UC methylation of CpG5 was associated with higher total fat mass at 4 years (p = 0.031), total fat mass at 6-7 years (p = 0.0001) and % fat mass at 6-7 years (p = 0.004). Lower UC methylation of CpG5 was also associated with higher triceps skinfold thickness at birth (p = 0.013), 6 months (p = 0.038), 12 months (p = 0.062), 2 years (p = 0.0003), 3 years (p = 0.00004) and 6-7 years (p = 0.013). Higher maternal pregnancy weight gain (p = 0.046) and lower parity (p = 0.029) were both associated with lower SLC6A4 CpG5 methylation. In adolescents, lower methylation of CpG5 in peripheral blood was associated with greater concurrent measures of adiposity including BMI (p ≤ 0.001), waist circumference (p = 0.011), subcutaneous fat (p ≤ 0.001) and subscapular, abdominal and suprailiac skinfold thicknesses (p = 0.002, p = 0.008, p = 0.004, respectively). In adipose tissue, methylation of both SLC6A4 CpG5 (p = 0.019) and expression of SLC6A4 (p = 0.008) was lower in obese compared with lean adults. CONCLUSIONS: These data suggest that altered methylation of CpG loci within SLC6A4 may provide a robust marker of adiposity across the life course.


Subject(s)
Adiposity/genetics , DNA Methylation/physiology , Epigenesis, Genetic/physiology , Metabolic Diseases/genetics , Obesity/genetics , Serotonin Plasma Membrane Transport Proteins/metabolism , Absorptiometry, Photon , Adolescent , Adult , Australia/epidemiology , Biomarkers/metabolism , Child , Child, Preschool , Cohort Studies , DNA Methylation/genetics , Female , Gene-Environment Interaction , Genetic Predisposition to Disease , Humans , Infant, Newborn , Male , Metabolic Diseases/epidemiology , Obesity/epidemiology , Promoter Regions, Genetic/genetics
4.
J Bone Miner Res ; 34(2): 231-240, 2019 02.
Article in English | MEDLINE | ID: mdl-30321476

ABSTRACT

We have previously demonstrated inverse associations between maternal 25(OH)-vitamin D status and perinatal DNA methylation at the retinoid-X-receptor-alpha (RXRA) locus and between RXRA methylation and offspring bone mass. In this study, we used an existing randomized trial to test the hypothesis that maternal gestational vitamin D supplementation would lead to reduced perinatal RXRA locus DNA methylation. The Maternal Vitamin D Osteoporosis Study (MAVIDOS) was a multicenter, double-blind, randomized, placebo-controlled trial of 1000 IU/day cholecalciferol or matched placebo from 14 weeks' gestation until delivery. Umbilical cord (fetal) tissue was collected at birth and frozen at -80°C (n = 453). Pyrosequencing was used to undertake DNA methylation analysis at 10 CpG sites within the RXRA locus (identified previously). T tests were used to assess differences between treatment groups in methylation at the three most representative CpG sites. Overall, methylation levels were significantly lower in the umbilical cord from offspring of cholecalciferol-supplemented mothers, reaching statistical significance at four CpG sites, represented by CpG5: mean difference in % methylation between the supplemented and placebo groups was -1.98% (95% CI, -3.65 to -0.32, p = 0.02). ENCODE (Encyclopedia of DNA Elements) evidence supports the functionality of this locus with strong DNase hypersensitivity and enhancer chromatin within biologically relevant cell types including osteoblasts. Enrichment of the enhancer-related H3K4me1 histone mark is also seen in this region, as are binding sites for a range of transcription factors with roles in cell proliferation, response to stress, and growth factors. Our findings are consistent with previous observational results and provide new evidence that maternal gestational supplementation with cholecalciferol leads to altered perinatal epigenetic marking, informing mechanistic understanding of early life mechanisms related to maternal vitamin D status, epigenetic marks, and bone development. © 2018 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals Inc.


Subject(s)
CpG Islands , DNA Methylation/drug effects , Dietary Supplements , Genetic Loci , Retinoid X Receptor alpha , Vitamin D/analogs & derivatives , Adult , Double-Blind Method , Female , Humans , Infant, Newborn , Male , Pregnancy , Retinoid X Receptor alpha/genetics , Retinoid X Receptor alpha/metabolism , Vitamin D/administration & dosage
5.
EBioMedicine ; 19: 60-72, 2017 May.
Article in English | MEDLINE | ID: mdl-28473239

ABSTRACT

Experimental studies show a substantial contribution of early life environment to obesity risk through epigenetic processes. We examined inter-individual DNA methylation differences in human birth tissues associated with child's adiposity. We identified a novel association between the level of CpG methylation at birth within the promoter of the long non-coding RNA ANRIL (encoded at CDKN2A) and childhood adiposity at age 6-years. An association between ANRIL methylation and adiposity was also observed in three additional populations; in birth tissues from ethnically diverse neonates, in peripheral blood from adolescents, and in adipose tissue from adults. Additionally, CpG methylation was associated with ANRIL expression in vivo, and CpG mutagenesis in vitro inhibited ANRIL promoter activity. Furthermore, CpG methylation enhanced binding to an Estrogen Response Element within the ANRIL promoter. Our findings demonstrate that perinatal methylation at loci relevant to gene function may be a robust marker of later adiposity, providing substantial support for epigenetic processes in mediating long-term consequences of early life environment on human health.


Subject(s)
Adiposity/genetics , Cyclin-Dependent Kinase Inhibitor p18/genetics , Promoter Regions, Genetic , RNA, Long Noncoding/genetics , Adolescent , Adult , Aged , Biomarkers , Cell Line, Tumor , Child , CpG Islands , Cyclin-Dependent Kinase Inhibitor p16 , DNA Methylation , Epigenesis, Genetic , Female , Humans , Infant , Infant, Newborn , Male , Middle Aged , Obesity/genetics , Young Adult
6.
J Bone Miner Res ; 32(10): 2030-2040, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28419547

ABSTRACT

Poor intrauterine and childhood growth has been linked with the risk of osteoporosis in later life, a relationship that may in part be mediated through altered epigenetic regulation of genes. We previously identified a region within the promoter of the long non-coding RNA ANRIL encoded by the CDKN2A locus, at which differential DNA methylation at birth showed correlations with offspring adiposity. Given the common lineage of adipocytes and osteoblasts, we investigated the relationship between perinatal CDKN2A methylation and bone mass at ages 4 and 6 years. Using sodium bisulfite pyrosequencing, we measured the methylation status of the 9 CpGs within this region in umbilical cord samples from discovery (n = 332) and replication (n = 337) cohorts of children from the Southampton Women's Survey, whose bone mass was assessed by dual-energy X-ray absorptiomietry (DXA; Hologic Discovery). Inverse associations were found between perinatal CDKN2A methylation and whole-body minus head bone area (BA), bone mineral content (BMC), and areal bone mineral density (BMD). This was confirmed in replication and combined data sets (all p < 0.01), with each 10% increase in methylation being associated with a decrease in BMC of 4 to 9 g at age 4 years (p ≤ 0.001). Relationships were similar with 6-year bone mass. Functional investigation of the differentially methylated region in the SaOS-2 osteosarcoma cell line showed that transcription factors bound to the identified CpGs in a methylation-specific manner and that CpG mutagenesis modulated ANRIL expression. In conclusion, perinatal methylation at CDKN2A is associated with childhood bone development and has significance for cell function. © 2017 American Society for Bone and Mineral Research.


Subject(s)
Bone and Bones/anatomy & histology , Cyclin-Dependent Kinase Inhibitor p18/genetics , DNA Methylation/genetics , Health Surveys , Adult , Bone Density/genetics , Calcification, Physiologic/genetics , Cell Line, Tumor , Cohort Studies , CpG Islands/genetics , Cyclin-Dependent Kinase Inhibitor p16 , Female , Humans , Infant, Newborn , Organ Size , Osteosarcoma/pathology , United Kingdom
7.
Article in English | MEDLINE | ID: mdl-27088334

ABSTRACT

It is now widely recognized that the environment in early life can have important effects on human growth and development, including the 'programming' of far-reaching effects on the risk of developing common metabolic and other noncommunicable diseases in later life. We have shown that greater childhood adiposity is associated with higher maternal adiposity, low maternal vitamin D status, excessive gestational weight gain and short duration of breast-feeding; maternal dietary patterns in pregnancy and vitamin D status have been linked with childhood bone mineral content and muscle function. Human studies have identified fetal liver blood flow adaptations and epigenetic changes as potential mechanisms that could link maternal influences with offspring body composition. In experimental studies, there is now substantial evidence that the environment during early life induces altered phenotypes through epigenetic mechanisms. Epigenetic processes, such as DNA methylation, covalent modifications of histones and non-coding RNAs, can induce changes in gene expression without a change in DNA base sequence. Such processes are involved in cell differentiation and genomic imprinting, as well as the phenomenon of developmental plasticity in response to environmental influences. Elucidation of such epigenetic processes may enable early intervention strategies to improve early development and growth.


Subject(s)
Diet, Healthy , Energy Intake , Energy Metabolism , Epigenesis, Genetic , Healthy Lifestyle , Human Development , Models, Biological , Adiposity , Adolescent , Adult , Child , Child Development , Child Nutritional Physiological Phenomena , Female , Fetal Development , Humans , Infant , Male , Maternal Nutritional Physiological Phenomena , Pregnancy
8.
Int J Epidemiol ; 44(4): 1263-76, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25906782

ABSTRACT

BACKGROUND: Early life environments induce long-term changes in neurocognitive development and behaviour. In animal models, early environmental cues affect neuropsychological phenotypes via epigenetic processes but, as yet, there is little direct evidence for such mechanisms in humans. METHOD: We examined the relation between DNA methylation at birth and child neuropsychological outcomes in two culturally diverse populations using a genome-wide methylation analysis and validation by pyrosequencing. RESULTS: Within the UK Southampton Women's Survey (SWS) we first identified 41 differentially methylated regions of interest (DMROI) at birth associated with child's full-scale IQ at age 4 years. Associations between HES1 DMROI methylation and later cognitive function were confirmed by pyrosequencing in 175 SWS children. Consistent with these findings, higher HES1 methylation was associated with higher executive memory function in a second independent group of 200 SWS 7-year-olds. Finally, we examined a pathway for this relationship within a Singaporean cohort (n = 108). Here, HES1 DMROI methylation predicted differences in early infant behaviour, known to be associated with academic success. In vitro, methylation of HES1 inhibited ETS transcription factor binding, suggesting a functional role of this site. CONCLUSIONS: Thus, our findings suggest that perinatal epigenetic processes mark later neurocognitive function and behaviour, providing support for a role of epigenetic processes in mediating the long-term consequences of early life environment on cognitive development.


Subject(s)
Basic Helix-Loop-Helix Transcription Factors/genetics , Child Behavior/psychology , Cognition , DNA Methylation , Epigenesis, Genetic , Homeodomain Proteins/genetics , Adult , Child , Child, Preschool , Female , Humans , Male , Pregnancy , Promoter Regions, Genetic , Prospective Studies , Regression Analysis , Transcription Factor HES-1
9.
Epigenetics ; 8(9): 944-52, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23867713

ABSTRACT

Reduced fetal growth associates with endothelial dysfunction and cardiovascular risk in both young and adult offspring and the nitric oxide (NO) system has been implicated in these effects. Epigenetic processes are likely to underlie such effects, but there is to date no evidence that endothelial dysfunction in early life results from epigenetic processes on key genes in the NO system, such as NOS3 (eNOS) and ARG2 (arginase-2). We determined basal DNA methylation status in NOS3 and ARG2 promoters, and DNA methyltransferase 1 (DNMT1) effect on eNOS and arginase-2 expression using human endothelial cells isolated from umbilical arteries (HUAEC) and veins (HUVEC) from control and intrauterine growth restricted (IUGR) fetuses. Compared with cells from control pregnancies, eNOS protein and mRNA levels were increased in HUAEC, but decreased in HUVEC, from IUGR, while arginase-2 levels were increased in IUGR-HUVEC. The NOS3 promoter showed a decrease in DNA methylation at CpG -352 in IUGR-HUAEC, and an increase in IUGR-HUVEC, when compared with control cells. Methylation in the hypoxia response element of the NOS3 promoter was increased in IUGR-HUAEC and decreased in HUVEC. Methylation in the AGR2 promoter in IUGR-HUVEC was decreased in a putative HRE, and without changes in IUGR-HUAEC. Silencing of DNMT1 expression normalized eNOS expression in IUGR endothelial cells, and restored the normal response to hypoxia in HUVEC, without effects on arginase-2. This data suggest that eNOS expression in IUGR-derived endothelial cells is programmed by altered DNA methylation, and can be reversed by transient silencing of the DNA methylation machinery.


Subject(s)
Arginase/genetics , DNA (Cytosine-5-)-Methyltransferases/metabolism , Endothelial Cells/enzymology , Fetal Growth Retardation/enzymology , Nitric Oxide Synthase Type III/genetics , Adult , Arginase/metabolism , Base Sequence , Binding Sites , Cell Hypoxia , Cells, Cultured , CpG Islands , DNA (Cytosine-5-)-Methyltransferase 1 , DNA Methylation , Epigenesis, Genetic , Female , Fetus , Gene Expression Regulation, Developmental , Gene Knockdown Techniques , Human Umbilical Vein Endothelial Cells , Humans , Male , Nitric Oxide Synthase Type III/metabolism , Pregnancy , Promoter Regions, Genetic , Response Elements
10.
Reprod Sci ; 20(10): 1144-55, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23420826

ABSTRACT

Suboptimal maternal nutrition and body composition are implicated in metabolic disease risk in adult offspring. We hypothesized that modest disruption of glucose homeostasis previously observed in young adult sheep offspring from ewes of a lower body condition score (BCS) would deteriorate with age, due to changes in skeletal muscle structure and insulin signaling mechanisms. Ewes were fed to achieve a lower (LBCS, n = 10) or higher (HBCS, n = 14) BCS before and during pregnancy. Baseline plasma glucose, glucose tolerance and basal glucose uptake into isolated muscle strips were similar in male offspring at 210 ± 4 weeks. Vastus total myofiber density (HBCS, 343 ± 15; LBCS, 294 ± 14 fibers/mm(2), P < .05) and fast myofiber density (HBCS, 226 ± 10; LBCS 194 ± 10 fibers/mm(2), P < .05), capillary to myofiber ratio (HBCS, 1.5 ± 0.1; LBCS 1.2 ± 0.1 capillary:myofiber, P < .05) were lower in LBCS offspring. Vastus protein levels of Akt1 were lower (83% ± 7% of HBCS, P < .05), and total glucose transporter 4 was increased (157% ± 6% of HBCS, P < .001) in LBCS offspring, Despite the reduction in total myofiber density in LBCS offspring, glucose tolerance was normal in mature adult life. However, such adaptations may lead to complications in metabolic control in an overabundant postnatal nutrient environment.


Subject(s)
Body Composition/physiology , Glucose Transporter Type 4/metabolism , Glucose/metabolism , Muscle, Skeletal/metabolism , Pregnancy/metabolism , Age Factors , Animals , Female , Glucose Tolerance Test/methods , Male , Organ Culture Techniques , Sheep , Up-Regulation/physiology
11.
Psychoneuroendocrinology ; 37(6): 782-8, 2012 Jun.
Article in English | MEDLINE | ID: mdl-21978868

ABSTRACT

BACKGROUND: Glucocorticoids are the key regulators of the biological stress response and act by binding to glucocorticoid receptors (GR). Expression of GR is altered by DNA methylation. Methylation patterns in GR promoters have been shown to be highly variable between individuals, but little is known about the functional consequences of this variation for the acute stress response. The present study investigated associations between methylation status of the GR 1-C promoter and cortisol, cardiovascular and perceived stress responses to a psychosocial stress protocol in a large healthy adult population. METHODS: A total of 725 overall healthy men and women, aged 55-60 years, participated in a standardized psychosocial stress protocol consisting of three different stressors. At different stages during the stress protocol, salivary cortisol levels, continuous blood pressure and heart rate (HR) levels as well as perceived stress were measured. Stress reactivity was calculated as the increase between basal and peak measurements. Methylation status of the GR 1-C promoter was assessed in DNA isolated from peripheral blood samples using a methylation sensitive PCR assay for 675 of the 725 participants. RESULTS: A decrease in methylation of the GR 1-C promoter was associated with a decrease in stress reactivity as indicated by lower cortisol and lower HR reactivity. A 1% decrease in GR 1-C methylation corresponded with a cortisol decrease by 0.14% (95% CI: 0.03-0.25, p=0.02) and an HR decrease by 0.10 bpm (0.03-0.16, p=0.003). Adjusting for sex, lifestyle and education largely abolished these associations. A decrease in methylation of the GR 1-C promoter was also associated with an increase in stress perception as indicated by higher perceived stress (0.03 points [0.00-0.06, p=0.05]), lower perceived performance (-0.03 points [-0.05 to -0.01], p=0.02), and lower perceived control (-0.03 points [-0.05 to 0.00], p=0.04). After adjusting for sex and educational level the associations were no longer statistically significant. GR 1-C methylation status was not associated with blood pressure responses to the stress protocol. DISCUSSION: Although effects were small, variation in methylation status in the GR 1-C promoter was associated with physical and perceived acute stress responses. Interestingly, these associations could largely be explained by differences in lifestyle and education.


Subject(s)
DNA Methylation/physiology , Educational Status , Life Style , Promoter Regions, Genetic/genetics , Receptors, Glucocorticoid/genetics , Stress, Psychological/genetics , Acute Disease , Blood Pressure/physiology , Cohort Studies , Female , Heart Rate/physiology , Humans , Male , Middle Aged , Netherlands , PPAR alpha/genetics , PPAR alpha/metabolism , Polymerase Chain Reaction , Socioeconomic Factors , Starvation
12.
J Physiol ; 587(3): 611-24, 2009 Feb 01.
Article in English | MEDLINE | ID: mdl-19103677

ABSTRACT

Undernourished late gestation fetuses display asymmetric growth restriction, suggestive of a redistribution of nutritional resources. The modification of fetal organ blood supply in response to acute hypoxia is well characterized, but it is not known whether similar responses occur in response to acute reductions in nutrition, or if such late gestation responses can be influenced by early gestation nutrition. In pregnant sheep, total nutrient requirements were restricted during the peri-implantation period (PI40, 40%; PI50, 50% of total, days 1-31) or in late gestation (L, 50% total, days 104-postmortem). Control animals were fed 100% nutrient requirements. Fetal organ blood flows were measured at baseline, and during acute fetal hypoglycaemia induced by maternal insulin infusion at 125 dGA. Baseline heart rate was increased in PI40 fetuses. During hypoglycaemia, an initial rise in fetal heart rate was followed by a slower fall. Fetal femoral artery blood flow decreased, and adrenal blood flow and femoral vascular resistance increased in all fetuses during hypoglycaemia. These changes were accompanied by increased fetal plasma adrenaline and cortisol, and reduced plasma insulin levels. The maximum femoral artery blood flow response to hypoglycaemia occurred earlier in PI50 and PI40 compared with control fetuses. The late gestation fetal cardiovascular response to acute hypoglycaemia was consistent with a redistribution of combined ventricular output away from the periphery and towards central organs. One element of the peripheral vascular response was modified by peri-implantation nutrient restriction, indicating that nutritional challenges early in gestation can have an enduring impact on cardiovascular control.


Subject(s)
Cardiovascular System/physiopathology , Fetal Nutrition Disorders/physiopathology , Fetus/physiopathology , Hypoglycemia/physiopathology , Prenatal Nutritional Physiological Phenomena , Adrenocorticotropic Hormone/blood , Animals , Blood Gas Analysis , Blood Glucose/analysis , Cardiovascular System/embryology , Catecholamines/blood , Female , Fetal Nutrition Disorders/blood , Fetal Nutrition Disorders/pathology , Fetal Weight , Gestational Age , Hemodynamics , Hydrocortisone/blood , Hypoglycemia/blood , Hypoglycemia/chemically induced , Hypoglycemia/embryology , Hypoglycemia/pathology , Hypoglycemic Agents/pharmacology , Insulin/blood , Insulin/pharmacology , Lactic Acid/blood , Pregnancy , Sheep
13.
J Physiol ; 586(9): 2371-9, 2008 May 01.
Article in English | MEDLINE | ID: mdl-18339691

ABSTRACT

Poor prenatal nutrition is associated with a greater risk of adult glucose intolerance and insulin insensitivity in the offspring. Skeletal muscle is the primary tissue for glucose utilization, and insulin resistance in muscle is the earliest identifiable abnormality in the pre-diabetic patient. We investigated the effect of early and late gestation undernutrition on structure and markers of growth and glucose metabolism regulation in the fetal triceps brachii (TB, slow- and fast-twitch myofibres) and soleus (slow-twitch myofibres) muscles. Pregnant sheep were fed 100% nutrient requirements (C, n = 8) or a restricted diet peri-implantation (PI, n = 9; 40%, 1-31 days gestation (dGA) (term approximately 147)) or in late gestation (L, n = 6; 50%, 104-127 dGA). At 127 +/- 1 dGA we measured myofibre and capillary density in the fetal TB and soleus muscles, and mRNA levels in the TB of insulin receptor (InsR), glucose transporter-4 (GLUT-4) and type 1 insulin-like growth factor receptor (IGF-1R). Total myofibre and capillary densities were lower in the TB, but not the soleus, of PI and L fetuses. The predominant effect in the L group was on slow-twitch myofibres. In TB, InsR, GLUT-4 and IGF-1R mRNA levels were greater in L group fetuses. Our finding of reduced myofibre density is consistent with a redistribution of resources at the expense of specific peripheral tissues by early and late gestation undernutrition which may be mediated by a decrease in capillary density. The increase in key regulatory components of glucose uptake following late gestation undernutrition may constitute a short-term compensation to maintain glucose homeostasis in the face of fewer type I (insulin-sensitive) myofibres. However, together these adaptations may influence the risk of later metabolic disease and thus our findings have implications for future strategies aimed at improving maternal diet.


Subject(s)
Embryo Implantation , Fetal Nutrition Disorders/physiopathology , Maternal Nutritional Physiological Phenomena , Muscle, Skeletal/embryology , Muscle, Skeletal/physiopathology , Pregnancy Complications/physiopathology , Animals , Female , Gestational Age , Pregnancy , Pregnancy, Animal , Sheep
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