Functional and transcriptional differences in monocytes from children with obesity compared to children of healthy weight

Background and aim

Cardiometabolic risk accrues across the entire life course and childhood is a key epoch for effective prevention. Obesity in childhood is the most prevalent modifiable risk factor for later cardiovascular disease (CVD). Inflammatory biomarkers and innate immune capacity are increased in adults with obesity, but childhood data are scarce. We aimed to investigate (i) innate immune cell activation in children with and without obesity; and (ii) whether weight loss impacts the innate immune inflammatory phenotype.

Methods

The innate immune phenotype of Peripheral Blood Mononuclear Cells (PBMCs) from 31 children with obesity (BMI z-score>2.5) and 22 children of healthy weight (−1.5≤BMIz≤1.5, sex, age and pubertal stage matched) was characterized by high dimensional flow cytometry, ex vivo stimulation assays with subsequent 27-plex cytokine measurements, and transcriptome analysis using RNA sequencing (Figure 1). Children with obesity participated to the Royal Children's Hospital Weight Management Service (median 5 years) and at follow-up, PBMCs were obtained again as well as anthropometric data and subclinical cardiovascular phenotypes.

Results

Flow cytometric analysis showed marked differences in cell composition between children with obesity and children of healthy weight. Specifically, children with obesity have significant changes in monocyte subsets and an increased expression of monocyte activation markers. Upon stimulation, monocytes of children with obesity show an increased cytokine production capacity. Finally, transcriptomic analysis shows significant differences between monocytes from obese children and healthy controls. Effects of weight loss on these immune parameters and correlations with preclinical CVD phenotypes are currently being analysed.

Conclusions

Monocytes from children with obesity have a pro-inflammatory phenotype compared to children of normal weight. Heightened inflammation may contribute to increased CVD risk later in life and may offer opportunities for early intervention.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): Dutch Scientific Organisation (NWO) - Rubicon grant to S.B. Dutch Heart Foundation - CVON IN CONTROL II to N.P.R. and D.B. Figure 1. Schematical overview of study

Urate-induced epigenetic modifications in myeloid cells

OBJECTIVES

Hyperuricemia is a metabolic condition central to gout pathogenesis. Urate exposure primes human monocytes towards a higher capacity to produce and release IL-1β. In this study, we assessed the epigenetic processes associated to urate-mediated hyper-responsiveness.

METHODS

Freshly isolated human peripheral blood mononuclear cells or enriched monocytes were pre-treated with solubilized urate and stimulated with LPS with or without monosodium urate (MSU) crystals. Cytokine production was determined by ELISA. Histone epigenetic marks were assessed by sequencing immunoprecipitated chromatin. Mice were injected intraarticularly with MSU crystals and palmitate after inhibition of uricase and urate administration in the presence or absence of methylthioadenosine. DNA methylation was assessed by methylation array in whole blood of 76 participants with normouricemia or hyperuricemia.

RESULTS

High concentrations of urate enhanced the inflammatory response in vitro in human cells and in vivo in mice, and broad-spectrum methylation inhibitors reversed this effect. Assessment of histone 3 lysine 4 trimethylation (H3K4me3) and histone 3 lysine 27 acetylation (H3K27ac) revealed differences in urate-primed monocytes compared to controls. Differentially methylated regions (e.g. HLA-G, IFITM3, PRKAB2) were found in people with hyperuricemia compared to normouricemia in genes relevant for inflammatory cytokine signaling.

CONCLUSION

Urate alters the epigenetic landscape in selected human monocytes or whole blood of people with hyperuricemia compared to normouricemia. Both histone modifications and DNA methylation show differences depending on urate exposure. Subject to replication and validation, epigenetic changes in myeloid cells may be a therapeutic target in gout.

DNA methylation of amino acid transporter genes in the human placenta

INTRODUCTION

Placental transfer of amino acids via amino acid transporters is essential for fetal growth. Little is known about the epigenetic regulation of amino acid transporters in placenta. This study investigates the DNA methylation status of amino acid transporters and their expression across gestation in human placenta.

METHODS

BeWo cells were treated with 5-aza-2'-deoxycytidine to inhibit methylation and assess the effects on amino acid transporter gene expression. The DNA methylation levels of amino acid transporter genes in human placenta were determined across gestation using DNA methylation array data. Placental amino acid transporter gene expression across gestation was also analysed using data from publically available Gene Expression Omnibus data sets. The expression levels of these transporters at term were established using RNA sequencing data.

RESULTS

Inhibition of DNA methylation in BeWo cells demonstrated that expression of specific amino acid transporters can be inversely associated with DNA methylation. Amino acid transporters expressed in term placenta generally showed low levels of promoter DNA methylation. Transporters with little or no expression in term placenta tended to be more highly methylated at gene promoter regions. The transporter genes SLC1A2, SLC1A3, SLC1A4, SLC7A5, SLC7A11 and SLC7A10 had significant changes in enhancer DNA methylation across gestation, as well as gene expression changes across gestation.

CONCLUSION

This study implicates DNA methylation in the regulation of amino acid transporter gene expression. However, in human placenta, DNA methylation of these genes remains low across gestation and does not always play an obvious role in regulating gene expression, despite clear evidence for differential expression as gestation proceeds.

The effects of maternal anxiety during pregnancy on IGF2/H19 methylation in cord blood

Compelling evidence suggests that maternal mental health in pregnancy can influence fetal development. The imprinted genes, insulin-like growth factor 2 (IGF2) and H19, are involved in fetal growth and each is regulated by DNA methylation. This study aimed to determine the association between maternal mental well-being during pregnancy and differentially methylated regions (DMRs) of IGF2 (DMR0) and the IGF2/H19 imprinting control region (ICR) in newborn offspring. Maternal depression, anxiety and perceived stress were assessed at 28 weeks of pregnancy in the Barwon Infant Study (n=576). DNA methylation was measured in purified cord blood mononuclear cells using the Sequenom MassArray Platform. Maternal anxiety was associated with a decrease in average ICR methylation (Δ=-2.23%; 95% CI=-3.68 to -0.77%), and across all six of the individual CpG units in anxious compared with non-anxious groups. Birth weight and sex modified the association between prenatal anxiety and infant methylation. When stratified into lower (⩽3530 g) and higher (>3530 g) birth weight groups using the median birth weight, there was a stronger association between anxiety and ICR methylation in the lower birth weight group (Δ=-3.89%; 95% CI=-6.06 to -1.72%), with no association in the higher birth weight group. When stratified by infant sex, there was a stronger association in female infants (Δ=-3.70%; 95% CI=-5.90 to -1.51%) and no association in males. All the linear regression models were adjusted for maternal age, smoking and folate intake. These findings show that maternal anxiety in pregnancy is associated with decreased IGF2/H19 ICR DNA methylation in progeny at birth, particularly in female, low birth weight neonates. ICR methylation may help link poor maternal mental health and adverse birth outcomes, but further investigation is needed.

IFPA meeting 2014 workshop report: Animal models to study pregnancy pathologies; new approaches to study human placental exposure to xenobiotics; biomarkers of pregnancy pathologies; placental genetics and epigenetics; the placenta and stillbirth and fetal growth restriction

Workshops are an important part of the IFPA annual meeting as they allow for discussion of specialized topics. At IFPA meeting 2014 there were six themed workshops, five of which are summarized in this report. These workshops related to various aspects of placental biology but collectively covered areas of animal models, xenobiotics, pathological biomarkers, genetics and epigenetics, and stillbirth and fetal growth restriction.

IFPA Meeting 2010 Workshop Report I: Immunology; ion transport; epigenetics; vascular reactivity; epitheliochorial placentation; proteomics

Workshops are an important part of the IFPA annual meeting. At IFPA Meeting 2010 there were twelve themed workshops, six of which are summarized in this report. 1. The immunology workshop focused on normal and pathological functions of the maternal immune system in pregnancy. 2. The transport workshop dealt with regulation of ion and water transport across the syncytiotrophoblast of human placenta. 3. The epigenetics workshop covered DNA methylation and its potential role in regulating gene expression in placental development and disease. 4. The vascular reactivity workshop concentrated on methodological approaches used to study placental vascular function. 5. The workshop on epitheliochorial placentation covered current advances from in vivo and in vitro studies of different domestic species. 6. The proteomics workshop focused on a variety of techniques and procedures necessary for proteomic analysis and how they may be implemented for placental research.

The basic morphological characteristics of astrocytomas in Vojvodina in the period 2001-2006

PURPOSE

Astrocytomas are the most common primary intracranial neoplasms. The aim of this investigation was to register the age, sex, tumor localization, frequency and histological types of patients with astrocytomas.

METHODS

The investigation was carried out from January 2001 to June 2006 and included 490 consecutive patients of both sexes with diagnosed intracranial tumors, who had undergone surgical treatment at the Neurosurgery Clinic of the Clinical Centre of Vojvodina. Tumor histological studies were carried out in the Laboratory of the Centre for Pathology and Histology of the Clinical Centre of Vojvodina. Out of 490 patients with diagnosed intracranial tumors, 139 (28.4%) had astrocytomas.

RESULTS

Astrocytomas were more frequent in males (63.3%) and were most common in the 50-59-year age group (39.5%). The most common localization was the frontal region (30.2%), more commonly on the right side (51.8%). In regard to other histological types of intracranial tumors, astrocytomas were more frequent in males (34.8%). Grade III astrocytomas were most common (55.4%). The frequency of hemorrhage and thrombosis showed a positive correlation with the histological grade of astrocytomas.

CONCLUSION

The typical patient with astrocytoma is a male of 50-59 years. The tumor is grade III located in the right frontal region.

Specific tumour-associated methylation in normal human term placenta and first-trimester cytotrophoblasts

Human placentation displays many similarities with tumourigenesis, including rapid cell division, migration and invasion, overlapping gene expression profiles and escape from immune detection. Recent data have identified promoter methylation in the Ras association factor and adenomatous polyposis coli tumour suppressor genes as part of this process. However, the extent of tumour-associated methylation in the placenta remains unclear. Using whole genome methylation data as a starting point, we have examined this phenomenon in placental tissue. We found no evidence for methylation of the majority of common tumour suppressor genes in term placentas, but identified methylation in several genes previously described in some human tumours. Notably, promoter methylation of four independent negative regulators of Wnt signalling has now been identified in human placental tissue and purified trophoblasts. Methylation is present in baboon, but not in mouse placentas. This supports a role for elevated Wnt signalling in primate trophoblast invasiveness and placentation. Examination of invasive choriocarcinoma cell lines revealed altered methylation patterns consistent with a role of methylation change in gestational trophoblastic disease. This distinct pattern of tumour-associated methylation implicates a coordinated series of epigenetic silencing events, similar to those associated with some tumours, in the distinct features of normal human placental invasion and function.

Radiation and scattering from imperfect cylindrical electromagnetic cloaks

The design of electromagnetic invisibility cloaks is based on singular mappings prescribing zero or infinite values for material parameters on the inner surface of the cloak. Since this is only approximately feasible, an asymptotic analysis is necessary for a sound description of cloaks. We adopt a simple and effective approach for analyzing electromagnetic cloaks - instead of the originally proposed singular mapping, nonsingular mappings asymptotically approaching the ideal one are considered. Scattering and radiation from this type of imperfect cylindrical cloaks is solved analytically and the results are confirmed by full-wave finite element simulations. Our analysis sheds more light on the influence of this kind of imperfection on the cloaking performance and further explores the physics of cloaking devices.

Absorbed fraction of radon progeny in human bronchial airways with bifurcation geometry

PURPOSE

The absorbed fraction, defined as the portion of the initial particle energy which is absorbed in the tissue of interest, was calculated, under bifurcation geometry of the airway tubes, for alpha-particles emitted from radon progeny in the human respiratory tract. The results are given for all branching generations and compared with the data obtained for the commonly used infinite straight cylinders adopted by the International Commission on Radiological Protection (ICRP) Report 66.

MATERIALS AND METHODS

A model was created to calculate the absorbed fraction of alpha-particle energy in the human lung using bifurcation geometry. Monte Carlo simulations of alpha-particle propagation in tissue and air were performed. The stopping powers of alpha-particles were adopted from the International Commission of Radiation Units and Measurements (ICRU) Report 49.

RESULTS

The absorbed fractions for the bifurcation geometry are given for the 15 generations in the tracheobronchial tree for alpha-particle energies of 6 and 7.69 MeV. The sources were assumed to be the fast and slow moving mucus.

CONCLUSIONS

Comparisons with ICRP66 data reveal that the assumption of long, straight cylinders was appropriate in some cases, but not in all. Adoption of the absorbed fractions obtained from the bifurcation model instead of the ICRP66 data caused 'redistribution' of doses in the bronchial (BB) and bronchiolar (bb) regions.

Late effects of therapy in survivors of Ewing's sarcoma family tumors

PURPOSE

This late effects study was designed to determine if survivors of Ewing's sarcoma family tumors (ESFT) had adverse outcomes in employment, marital status, fertility, and functional status when compared to sibling controls.

SUBJECTS AND METHODS

Eighty-nine survivors (case subjects) of ESFT treated at the National Cancer Institute between 1965 and 1992 and 97 sibling controls completed a questionnaire probing aspects of quality of life. The answers from case subjects were compared to pooled and matched sibling controls for all key variables. Odds ratios (OR) and p values from pooled analyses are presented.

RESULTS

Although case subjects and controls did not differ in educational achievement, case subjects were less likely to be employed full-time (OR 0.4, p < 0.01), to be married (OR 0.2, p < 0.01), and to have children (OR 0.3, p < 0.01). Their most common treatment-related difficulties included permanent hair and skin changes (43%), lung problems (18%), neurologic problems (14%), visual difficulties (10%), second malignancy (7%), and amputation (5%). Functional status, measured by Karnofsky performance scale, was also adversely affected in case subjects. Case subjects did not differ from sibling controls in health care insurance status or in utilization of health services.

CONCLUSIONS

Important aspects of life such as employment, marital status, fertility, and functional status are affected in survivors of ESFT. More studies are needed to better define the health status of adult survivors of pediatric cancer and the impact of cancer in adolescence on psychosocial development.

Can protocol-specified doses of chemotherapy and radiotherapy be used as a measure of treatment actually received? A CCG/NIH study on long-term survivors of acute lymphocytic leukemia

In a cohort of 593 long-term survivors of acute lymphocytic leukemia identified through the Children's Cancer Group (CCG), treatment abstracts were obtained and compared to protocol information on radiation therapy and intravenous chemotherapy. This was done in order to evaluate the actual compliance to protocol-specified treatment, and assess if protocol-specified doses can be used in studies of late effects of treatment. The compliance to protocol-specified type of treatment ranged between 95.3% (intrathecal methotrexate) and 98.6% (adriamycin) for chemotherapy, and between 94.1% (cranial radiation) and 97.0% (extended field radiation) for radiation. Concordance with the protocol-specified chemotherapy dose (+/- 25%) was 57.5% for adriamycin, 91.3% for daunomycin, and 48.5% for cyclophosphamide. When concordance was low, most patients received doses that were lower than expected. Concordance with chemotherapy was significantly lower for high-dose regimens than for low-dose regimens. Concordance with protocol-specified radiation dose (+/- 10%) was 87.4% for cranial radiation, 87.8% for spinal radiation, and 85.7% for extended field radiation. Concordance with treatment did not differ by gender, relapse status, or age at diagnosis. In this cohort of leukemia survivors, the validity of type of treatment was greater than the validity of dosage. Great care should be used when drawing conclusions about effects of treatment dosage. Although costly and time consuming, it appears that chart reviews are the most appropriate way to collect information about dose-related effects of therapy.

Experiences of cancer in children and adolescents

In an effort to understand the effect of cancer diagnosis and treatment in children and adolescents, and to identify issues that should be addressed with newly diagnosed patients, 85 patients with Ewing's sarcoma family tumors (ESFT) were interviewed about their experience of having cancer. This represents 90% of all eligible patients who survived at least 3 years since their diagnosis and who were treated for ESFT at the National Cancer Institute (NCI) from 1965-1993. The mean age of patients at the time of diagnosis was 15.8 +/- 5.3 years, and mean time since diagnosis was 13.6 +/- 6.4 years. Patients from this cohort had a disease usually related to poor outcome. Patients answered five open-ended written questions. Negative experiences that they described included transient and permanent discomfort and disabilities related to cancer; disruption of life or relationships; and emotional aspects of cancer diagnosis or treatment. Positive aspects of having cancer included changed attitudes about self and life, improved relationships with others, or better job performance. Advice for newly diagnosed patients most often dealt with the emotional aspects of cancer. The importance of patient-to-patient support was frequently described. Overall, having cancer was not an entirely negative experience, and it may result in introspection and improved relationships with others.

Melanocytic nevi, dysplastic nevi, and malignant melanoma in children from melanoma-prone families

BACKGROUND

Melanocytic nevi, particularly dysplastic nevi (DN), are important markers of increased risk of malignant melanoma in adults, but little is known about their prevalence and relation to melanoma in children.

OBJECTIVE

Our purpose was to define the prevalence of DN, number of nevi, and their relation to the risk of melanoma in children younger than 20 years of age from melanoma-prone families.

METHODS

One hundred twenty-five persons younger than 20 years of age, from 23 melanoma-prone families, underwent clinical evaluation with nevus counts, photography, and biopsy of suspected melanocytic lesions and were observed for development of DN and melanoma.

RESULTS

In melanoma-prone families, 37% of children had DN. The patients were divided into four categories: those with melanoma, DN (without melanoma), indeterminant (largely because of age at examination), and unaffected. The risk of melanoma was assessed by nevus number and presence of DN. High nevus number was strongly correlated with the presence of DN. The risk of the development of melanoma in children from melanoma-prone families appeared most related to the presence of DN (relative risk, 45; 95% confidence intervals, 2.6-786.4) and started at an early age. Of note, all children in whom melanoma developed had DN.

CONCLUSION

Family history of melanoma and the presence of DN defines children with a high risk for melanoma developing at an early age.

Childhood cancer

BACKGROUND

Cancers of individual organs generally are composed of various histologic types, each with its own frequency and demographic patterns. For childhood cancers in particular, a classification of cancers by histologic type is important for understanding the etiology and progression of the disease.

METHODS

Data from the Surveillance, Epidemiology, and End Results (SEER) Program on 9308 microscopically confirmed malignant neoplasms in children younger than age 15, newly diagnosed during 1973-1987, were made available for analysis. Tumors were grouped histologically according to a classification previously utilized in an international volume of childhood cancer incidence.

RESULTS

The most frequent histologic types were acute lymphocytic leukemia (23.6%), astrocytoma (9.6%), neuroblastoma (6.6%), and Wilms' tumor (6.4%). Acute lymphocytic leukemia accounted for 75% of childhood leukemia. The most common form of Hodgkin's disease was the nodular sclerosing subtype, which was diagnosed in 56% of all cases. Burkitt's and Burkitt-like disease accounted for approximately one third of non-Hodgkin's lymphoma, the sex ratio (male to female) being unusually high (5.7). Among the brain tumors, glioma was of interest because 198 cases (excluded from this analysis) were diagnosed without histologic confirmation--due, no doubt, to their inaccessibility for biopsy because they were located in the brain stem. The most common histologic type of soft tissue sarcoma was rhabdomyosarcoma, which accounted for 51% of the total, more than half of which were of the embryonal type. To the authors' knowledge, this report offers for the first time the relative frequencies of rare types of leukemias, such as megakaryoblastic leukemia, in childhood. This report also includes the frequencies of 21 rarer forms of soft tissue sarcoma. Five forms of childhood cancer had a 5-year relative survival rate of 85% or better. Of the cancers with the poorest outcome, three had relative survival rates of 46.5-49%; the relative survival rate of acute myelogenous leukemia was only 26.4%. The trends in survival over time for 21 types of childhood cancer also are included in this report.

CONCLUSIONS

Further refinements in classification now are available through laboratory techniques utilizing molecular biology, immunology, and cytogenetics, which are of importance in etiologic studies, diagnosis, treatment, and prognosis. It would be important in the future for cancer registries to record the results of relevant laboratory tests for further analysis by subtype.

Increased risk of neuroectodermal tumors and stomach cancer in relatives of patients with Ewing's sarcoma family of tumors

BACKGROUND

Previous studies of the genetic epidemiology of Ewing's sarcoma have shown neither an increased incidence nor a distinct pattern of cancers in family members of Ewing's sarcoma patients.

PURPOSE

Because of a new biologic and cytogenetic classification of Ewing's sarcoma family of tumors, we wanted to reinvestigate the incidence and distribution of cancers in relatives of probands with Ewing's sarcoma family of tumors.

METHODS

Patients treated at the Pediatric Branch and the Radiation Oncology Branch of the National Cancer Institute between 1965 and December 1992, or their next of kin, were asked to complete a questionnaire on the history of cancer in all first- and second-degree relatives. The incidence of cancer in family members was compared with Connecticut Tumor Registry rates specific for sex, age, and 5-year calendar-year intervals. Observed/expected (O/E) ratios, 95% confidence intervals (CIs), and tests of homogeneity were calculated.

RESULTS

Four thousand six hundred seventy-eight family members with 196,640 person-years at risk entered the analysis. Overall, there was no increased risk of cancer (observed 472; O/E = 0.9; 95% CI = 0.8-1.0). However, several tumor types were found in significant excess. These tumors included stomach cancer (observed 34; O/E = 2.0; 95% CI = 1.4-2.8), melanoma (observed 23; O/E = 1.9; 95% CI = 1.2-2.8), brain tumor (observed 18; O/E = 1.9; 95% CI = 1.1-3.0), and bone cancer (observed 7; O/E = 4.2; 95% CI = 1.7-8.6). Risks of these cancers were higher among maternal than paternal relatives, but these differences were not statistically significant. There was a significant deficit of bladder cancer (observed 5; O/E = 0.2; 95% CI = 0.1-0.5) and rectal cancer (observed 0; O/E = 0.0; 95% CI = 0.0-0.1). Second-degree relatives had a significant cancer deficit (observed 389; O/E = 0.9; 95% CI = 0.8-0.95). This deficit was accounted for by the observed deficit of bladder and rectal cancer and is probably related to under-reporting or misclassification of cancer in second-degree relatives. Family members of 10 probands with second malignancies did not have an increased risk of all cancers (observed 20; O/E = 1.2; 95% CI = 0.7-1.8) but had an increased risk of both melanoma (observed 3; O/E = 7.3; 95% CI = 1.5-21.0) and breast cancer (observed 8; O/E = 3.2; 95% CI = 1.4-6.3).

CONCLUSION

Finding an increased risk of neuroectodermal tumors and stomach cancer in families of patients with Ewing's sarcoma family of tumors suggests that these tumors might share a common etiology. Further studies should try to confirm this hypothesis and to examine if genetic factors may have a role in these families by assessing the mode of inheritance and examining families with multiple affected members.

U.S. childhood cancer survival, 1973-1987

The surveillance, epidemiology, and end-results (SEER) data on 5-year relative survival rates (1973-1987) for the most common pediatric tumors (ages 0-14) were analyzed. The SEER data are population based, so the observed progress in survival from childhood cancer represents the real impact that development in cancer treatment had on the population followed by the registry. The greatest increase in survival rate from 1973 until 1987 has been achieved in hematopoietic tumors such as acute lymphocytic leukemia (ALL), in which survival increased from 47.6% (1973-1977) to 60.8% (1983-1987), and Burkitt's lymphoma in which survival increased from 27.6% (1973-1977) to 68.7% (1983-1987). Solid tumors showed a less steep, but steady increase in survival rates. Flattening in the survival rates since 1978-1982 has been observed for acute leukemia, astrocytoma, medulloblastoma, and osteosarcoma. Females have better survival rates for most pediatric tumors, except Hodgkin's disease. Analysis of race of childhood leukemia confirmed that black children have worse survival than white. When solid tumors were analyzed by stage at presentation, there was no indication that diagnosis in earlier stages of disease accounted for the improved survival. Observed flattening in the survival rates since 1978-1982 of leukemia and some solid tumors warrants further follow-up.