Associations of Children’s Appetitive Traits with Weight and Dietary Behaviours in the Context of General Parenting

Background

Individual variations in child weight can be explained by genetic and behavioural susceptibility to obesity. Behavioural susceptibility can be expressed in appetite-related traits, e.g. food responsiveness. Research into such behavioural factors is important, as it can provide starting points for (preventive) interventions.

Objectives

To examine associations of children’s appetitive traits with weight and with fruit, snack and sugar-sweetened beverage intake, and to examine whether parenting style interacts with appetite in determining child weight/intake.

Methods

Data were used from 1275 children participating in the INPACT study in 2009–2010, with a mean age of 9 years in 2009. Their height and weight were measured to calculate body mass index (BMI). Parents completed a questionnaire to measure children’s appetitive traits, children’s dietary intake and parenting style. Child BMI z-scores, fruit, snack and sugar-sweetened beverage intake were regressed on appetitive traits. Moderation by parenting style was tested by adding interaction terms to the regression analyses.

Results

Food-approaching appetitive traits were positively, and food-avoidant appetitive traits were negatively related to child BMI z-scores and to child fruit intake. There were no or less consistent associations for snack and sugar-sweetened beverage intake. Authoritative parenting voided the negative association between food fussiness and fruit intake, while neglecting parenting strengthened the positive association between food-approaching appetitive traits and weight.

Conclusions

Early assessment of appetitive traits could be used to identify children at risk for overweight. As parenting style can moderate the associations between appetitive traits and weight/intake in a favourable way, parents are a promising target group for preventive interventions aimed at influencing the effect of appetitive traits on children.     

The global distribution and evolution of deoxyribonucleoside kinases in bacteria

Deoxyribonucleoside kinases (dNKs) are important to DNA metabolism, especially in environments where nucleosides are freely available to be absorbed and used for the salvage pathway. Little has previously been known about the complement of dNKs in different bacterial genomes. However, it was believed that Gram-negative bacteria had a single dNK, while Gram-positive bacteria possessed several. An analysis of 992 fully sequenced bacterial genomes, including both Gram-positive and Gram-negative organisms, was conducted to investigate the phylogenetic relationship of all TK1-like and non-TK1-like dNKs. It was illustrated that both gene families evolved through a number of duplications and horizontal gene transfers, leading to the presence of multiple dNKs in different types of bacteria. The findings of this study provide a backbone for further studies into the evolution of the interplay between the de novo and salvage pathways in DNA synthesis with respect to environmental availability of deoxyribonucleosides and metabolic processes generating the provisions of different dNTPs.     

Crystal structures of two solute receptors for L-cystine and L-cysteine, respectively, of the human pathogen Neisseria gonorrhoeae

ATP-binding cassette (ABC) transporters are integral membrane proteins that carry a variety of substrates across biological membranes at the expense of ATP. The here considered prokaryotic canonical importers consist of three entities: an extracellular solute receptor, two membrane-intrinsic proteins forming a translocation pathway, and two cytoplasmic ATP-binding subunits. The ngo0372-74 and ngo2011-14 gene clusters from the human pathogen Neisseria gonorrhoeae were predicted by sequence homology as ABC transporters for the uptake of cystine and cysteine, respectively, and chosen for structural characterization. The structure of the receptor component Ngo0372 was obtained in a ligand-free "open" conformation and in a "closed" conformation when co-crystallized with L-cystine. Our data provide the first structural information of an L-cystine ABC transporter. Dissociation constants of 21 and 33 nM for L-cystine and L-selenocystine, respectively, were determined by isothermal titration calorimetry. In contrast, L-cystathionine and L-djenkolic acid are weak binders, while no binding was detectable for S-methyl-L-cysteine. Mutational analysis of two residues from the binding pocket, Trp97 and Tyr59, revealed that the latter is crucial for L-cystine binding. The structure of the Ngo2014 receptor was obtained in closed conformation in complex with co-purified L-cysteine. The protein binds L-cysteine with a K(d) of 26 nM. Comparison of the structures of both receptors and analysis of the ligand binding sites shed light on the mode of ligand recognition and provides insight into the tight binding of both substrates. Moreover, since L-cystine limitation leads to reduction in virulence of N. gonorrhoeae, Ngo0372 might be suited as target for an antimicrobial vaccine.     

Medical history of optic chiasm compression in patients with pituitary insufficiency affects skin temperature and its relation to sleep

The hypothalamus is crucially involved in the circadian timing of the sleep-wake rhythm, yet also accommodates the most important thermoregulatory neuronal network. We have shown before that adults with pituitary insufficiency and history of chiasm compression due to a tumor with suprasellar extension fall asleep later and sleep shorter than those without such history and presumed hypothalamic involvement. To solidify the hypothesized link between vigilance and thermoregulation by the hypothalamus, we aimed to test the hypothesis that the presumed hypothalamic impairment in these patients also affects skin temperature and its association with sleep onset. In a case-control study of 50 patients (54.7?±?14.5 yrs of age, 30 males) with pituitary insufficiency, 33 of whom had a history of chiasm compression, ambulatory distal and proximal skin temperatures were assessed continuously for 24?h. Sleep parameters were assessed via questionnaire. Group differences in mean skin temperature, calculated over the wake and sleep periods separately, and group differences in the strength of association between pre-sleep skin temperature and sleep onset latency were compared. Results showed that patients with a medical history of chiasm compression had lower proximal skin temperature during the day (34.1°C?±?.7°C vs. 34.6°C?±?.7°C, p?=?.045). Additionally, the typical association between sleep onset latency and pre-sleep distal-to-proximal skin temperature gradient was absent in these patients (r?=?-.01, p?=?.96), whereas it was unimpaired in those without chiasm compression (r?=?-.61, p?=?.02). Thus, patients with history of chiasm compression show impaired skin temperature regulation in association with disturbed sleep. The findings support the hypothesis that a medical history of chiasm compression affects hypothalamic regulation of both vigilance and temperature, possibly by chronically affecting relevant nuclei, including the ventrolateral preoptic area and anterior hypothalamic preoptic area. (Corresponding Author: n.romeijn@nin.knaw.nl ).     

Geographic origin and past climatic experience influence the response to late spring frost in four common grass species in central Europe

Late spring frost events can affect vegetation. The response of grassland species, however, is generally unknown. We explore the late‐frost sensitivity of four common European grass species and investigate whether these species exhibit local adaptations to late frost on a continental scale and whether past climatic experience influences late frost sensitivity. Ecotypes of Arrhenatherum elatius, Alopecurus pratensis, Festuca pratensis, and Holcus lanatus from Spain, Italy, Bulgaria, Hungary, Sweden and Germany were exposed to late frost after drought and warming manipulations in the preceding growing season in a common garden experiment. Late frost reduced the productivity of the grasses on average by 20%. Ecotypes differed in their late‐frost sensitivity in three of the four species and local adaptations to late frost were identified. Previous exposure to drought and warming caused differences in late‐frost sensitivity in some cases. The impact of late frost events may increase in a warmer world due to an earlier onset of growing and no change in timing of late frost events. The history of climatic exposure can alter the performance of plants, possibly through epigenetic mechanisms. Based on the complex response pattern observed, a maximization of genetic diversity is proposed as a promising adaptation strategy against climate change.     

The simultaneous ex vivo detection of low-frequency antigen-specific CD4+ and CD8+ T-cell responses using overlapping peptide pools

The ability to measure antigen-specific T cells at the single-cell level by intracellular cytokine staining (ICS) is a promising immunomonitoring tool and is extensively applied in the evaluation of immunotherapy of cancer. The protocols used to detect antigen-specific CD8+ T-cell responses generally work for the detection of antigen-specific T cells in samples that have undergone at least one round of in vitro pre-stimulation. Application of a common protocol but now using long peptides as antigens was not suitable to simultaneously detect antigen-specific CD8+ and CD4+ T cells directly ex vivo in cryopreserved samples. CD8 T-cell reactivity to monocytes pulsed with long peptides as antigens ranged between 5 and 25?% of that observed against monocytes pulsed with a direct HLA class I fitting minimal CTL peptide epitope. Therefore, we adapted our ICS protocol and show that the use of tenfold higher concentration of long peptides to load APC, the use of IFN-α and poly(I:C) to promote antigen processing and improve T-cell stimulation, does allow for the ex vivo detection of low-frequency antigen-specific CD8+ and CD4+ T cells in an HLA-independent setting. While most of the improvements were related to increasing the ability to measure CD8+ T-cell reactivity following stimulation with long peptides to at least 50?% of the response detected when using a minimal peptide epitope, the final analysis of blood samples from vaccinated patients successfully showed that the adapted ICS protocol also increases the ability to ex vivo detect low-frequency p53-specific CD4+ T-cell responses in cryopreserved PBMC samples.     

Transient neonatal diabetes mellitus gene Zac1 impairs insulin secretion in mice through Rasgrf1

The biallelic expression of the imprinted gene ZAC1/PLAGL1 underlies ≈ 60% of all cases of transient neonatal diabetes mellitus (TNDM) that present with low perinatal insulin secretion. Molecular targets of ZAC1 misexpression in pancreatic β cells are unknown. Here, we identified the guanine nucleotide exchange factor Rasgrf1 as a direct Zac1/Plagl1 target gene in murine β cells. Doubling Zac1 expression reduced Rasgrf1 expression, the stimulus-induced activation of mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K) pathways, and, ultimately, insulin secretion. Normalizing Rasgrf1 expression reversed this phenotype. Moreover, the transplantation of Zac1-overexpressing β cells failed to reinstate euglycemia in experimental diabetic mice. In contrast, Zac1 expression did not interfere with the signaling of the glucagon-like peptide 1 receptor (GLP-1R), and the GLP-1 analog liraglutide improved hyperglycemia in transplanted experimental diabetic mice. This study unravels a mechanism contributing to insufficient perinatal insulin secretion in TNDM and raises new prospects for therapy.     

Synthesis of ‘cineole cassette’ monoterpenes in Nicotiana section Alatae: gene isolation, expression, functional characterization and phylogenetic analysis

The scent bouquets of flowers of Nicotiana species, particularly those of section Alatae, are rich in monoterpenes, including 1,8-cineole, limonene, β-myrcene, α- and β-pinene, sabinene, and α-terpineol. New terpene synthase genes were isolated from flowers of Nicotiana bonariensis, N. forgetiana, N. longiflora, and N. mutabilis. The recombinant enzymes synthesize simultaneously the characteristic 'cineole cassette' monoterpenes with 1,8-cineole as the dominant volatile product. Interestingly, amino acid sequence comparison and phylogenetic tree construction clustered the newly isolated cineole synthases (CIN) of section Alatae together with the catalytically similar CIN of N. suaveolens of section Suaveolentes, thus suggesting a common ancestor. These CIN genes of N. bonariensis, N. forgetiana, N. longiflora, and N. mutabilis are distinct from the terpineol synthases (TERs) of the taxonomically related N. alata and N. langsdorfii (both Alatae), thus indicating gene diversification of monoterpene synthases in section Alatae. Furthermore, the presence of CINs in species of the American section Alatae supports the hypothesis that one parent of the Australian section Suaveolentes was a member of the present section Alatae. Amino acid sequences of the Nicotiana CINs and TERs were compared to identify relevant amino acids of the cyclization reaction from α-terpineol to 1,8-cineole.     

Production and NMR analysis of the human ibuprofen metabolite 3-hydroxyibuprofen

The anti-inflammatory drug ibuprofen (Ibu) is metabolized in the human liver to a number of metabolites including 1-hydroxyibuprofen (1-OH-Ibu), 2-OH-Ibu, and 3-OH-Ibu, respectively. The only human CYP known to produce relevant amounts of 3-OH-Ibu is CYP2C9 and as genetic polymorphisms of CYP2C9 influence the metabolization of numerous drugs, the availability of reference standards for CYP2C9-specific metabolites is of considerable interest. The aim of this study was to develop a biological production process for 3-OH-Ibu and to affirm its NMR characteristics. The recombinant fission yeast strain CAD68 coexpressing human CYP2C9 and CPR was used for the whole-cell biotransformation of Ibu to 3-OH-Ibu in 1L batch-scale for 75h. The average space-time yield for the bioproduction of 3-OH-Ibu (125±34μmol/Ld) considerably exceeded that of 2-OH-Ibu (44±10μmol/Ld). Accordingly, average biotransformation activities normalized to dry biomass weight were 5.0±0.8μmol/gd (3-OH-Ibu) and 1.9±0.7μmol/gd (2-OH-Ibu). The metabolite was prepurified on preparative TLC-plates, isolated by HPLC fractionation, and characterized by LC-MS and NMR. As expected, differential fragmentation patterns of 2-OH-Ibu and 3-OH-Ibu were detected in ESI-LC-MS analysis. 44mg of 3-OH-Ibu was efficiently purified from four 1L batch cultures and its structure was clearly confirmed by one- and two-dimensional NMR.