Healthy pregnancy requires a tightly regulated materno-fetal dialogue for processes such as embryo implantation, endometrial decidualisation (in the mouse), placentation and maternal adaptation to occur. Disruption of placental development as well as maternal adaptation can lead to fetal intrauterine growth restriction (IUGR) which increases the risk of late miscarriage/stillbirth (e.g. 53% of preterm stillbirth and 26% of term stillbirth are found to be IUGR). Furthermore, IUGR is a risk factor for neurodevelopmental conditions in childhood and for a spectrum of related adult health disorders such as cardiovascular disease and type II diabetes, often termed metabolic syndrome. Despite these pregnancy disorders being common (e.g. 1 in 200 pregnancies results in stillbirth in the UK) the molecular lesion(s) underlying their pathophysiology are poorly understood and in particular those with placental and/or maternal aetiologies most frequently remain unexplained. Here we investigate the hypothesis that poly(A)-binding protein 4 (PABP4) is required for healthy pregnancy in mice. PABP4 is an RNA-binding protein and a member of the PABP family which are central regulators of mRNA translation and stability. Using all four permutations of wild-type and knock-out crosses, we find that maternal PABP4-deficiency results in a reduced litter size and IUGR. The number of implantations at e8.5 were not reduced in Pabp4-/- females, implying that the reduced litter size was not a consequence of decreased ovulation, fertilisation or implantation frequency. Further longitudinal analysis (at e13.5, e15.5 and e18.5) reveals that fetal death primarily occurred between e18.5 and birth, suggesting these mice may provide a unique opportunity to inform on the maternal causes of stillbirth. The onset of IUGR, which was found to be symmetrical in nature, was established by e15.5 preceding the majority of fetal death. During pregnancy, a materno-fetal dialogue directs and responds to changes in gene expression to give rise to the placenta and adapt the maternal physiology. Defects in these processes may result in reduced growth and/or fetal death and were examined in Pabp4-/- mice to shed light on the mechanistic basis of these related phenotypes. Fetal to placental (F:P) weight ratio, whose changes can be indicative of placental insufficiency or placental adaptation in an attempt to aid fetal growth, was found to be increased in Pabp4-/- dams at e15.5 and e18.5 due to the presence of IUGR fetuses with placentas of normal weight. Consistent with this observation, placental volume was unchanged at e18.5. Total placental weight and volume alone fails to discriminate potential differences in the individual placental zones which include the labyrinth zone, where materno-fetal gas and nutrient exchange occur; the junctional zone, which has endocrine functions including those that promote maternal adaptation; and the decidua basalis, derived from the maternal endometrium and is the site of trophoblast invasion and maternal vascular remodelling in early pregnancy. Therefore, volumetric analysis of these zones and the maternal blood spaces, which transcend the decidua basalis and junctional zone, was undertaken. This showed no change in the maternal blood spaces or the labyrinth, the latter being the zone whose size is most frequently altered in IUGR. Critically however, the size of the maternally-derived decidua basalis was increased with a concurrent decrease in the size of the junctional zone. These morphological changes may play a causative role either through directly affecting placental function and/or by the reduced junctional zone failing to promote appropriate maternal adaptation. Alternatively, they may reflect compensatory adaptations to a primary defect elsewhere in the mother. Complementing these morphological studies, functional studies were undertaken: remodelling of maternal vasculature and the resistance index of vessels delivering blood to the fetus were assessed; as was delivery of nutrients to the fetus (measured by fetal glucose); and systemic maternal adaptations (maternal hormonal profile, circulating glucose levels and organ weights). Uterine, umbilical and decidual spiral arteries were examined, but displayed no apparent differences suggestive of normal blood supply to the fetus. However fetal blood glucose was reduced suggesting a reduced delivery of nutrients important for fetal growth. This was not due to lower circulating maternal blood glucose levels, and mRNA levels of the placental glucose transporters Glut-1 and Glut-3 were not reduced but upregulated, suggestive of an attempt to compensate for reduced fetal glucose. Furthermore, upregulation of at least one system A amino acid transporter mRNA, Snat-2, was observed. The maternal physiological state of PABP4-deficient dams showed deviations in some organ weights (e.g. spleen weight is reduced at e13.5 and e15.5) and the levels of some circulating hormones (e.g. estradiol is deceased whereas progesterone is increased at e18.5). However, future work will be required to determine which, if any, of these changes are primary defects rather than downstream consequences and to identify which mis-regulated mRNAs/pathways within in the materno-fetal dialogue underlie the phenotype. Taken together, my results suggest that the regulation of mRNA translation/stability by PABP4 is critical to achieving the correct pattern of gene expression within the materno-fetal dialogue to enable appropriate placentation and maternal adaptation. Furthermore, my results suggest that Pabp4-/- mice provide a unique opportunity to further understand the maternal causes of a spectrum of related pregnancy complications including IUGR, late miscarriage and stillbirth.

This research was conducted to test the hypothesis that parenteralarginine supplementation is effective in enhancing birth weights of intrauterinegrowth restricted (IUGR) fetuses. Underfed and prolific ewes were used asexperimental models. The first study characterized the pharmacokinetics ofarginine and citrulline and assessed the potential of citrulline to serve as aprecursor for enhancing arginine availability in fetal and maternal plasma. Sixlate pregnant ewes and their fetuses were instrumented to access arterial andvenous circulations. Intravenous boluses of 155 mol of L-arginine-HCl or Lcitrullineper kg body weight were administered to each ewe. Administration ofcitrulline was more effective than arginine in achieving a sustained increase inconcentrations of arginine in maternal and fetal blood. Accordingly, theclearance rate of citrulline was lower and its biological half-life in maternal bloodgreater, when compared with arginine. The second experiment determined ifadministration of arginine to underfed ewes is effective in ameliorating orpreventing IUGR. Ewes were fed either 100% or 50% of the National ResearchCouncil recommended nutrient requirements for pregnant sheep. Between Day60 of pregnancy and parturition control-fed ewes received saline solution and underfed ewes received either saline solution or L-arginine-HCl solution (155mol of arginine/kg body weight) intravenously three times daily (n=5 / treatmentgroup). Birth weights of lambs were lower in saline-infused underfed ewes.There was no difference in birth weights of lambs from control-fed and argininetreatedunderfed ewes. The third experiment determined whether administrationof arginine could improve survival rates of lambs and enhance fetal growth inewes carrying multiple fetuses. Between Days 100 and 121 of pregnancy, ewesreceived an intravenous infusion of either saline solution (n= 14) or L-arginine-HCl solution (345 mol of arginine/kg body weight, n=20) three times daily.Parenteral administration of arginine increased the percentage of lambs bornalive and enhanced the birth weights of quadruplets. Collectively, these resultsindicate that 1) parenteral administration of arginine improves pregnancyoutcomes in underfed and prolific ewes; and 2) the use of arginine or citrullinemay have important implications for the design of an effective treatment forpreventing or ameliorating IUGR in mammals.

This research was conducted to test the hypothesis that parenteralarginine supplementation is effective in enhancing birth weights of intrauterinegrowth restricted (IUGR) fetuses. Underfed and prolific ewes were used asexperimental models. The first study characterized the pharmacokinetics ofarginine and citrulline and assessed the potential of citrulline to serve as aprecursor for enhancing arginine availability in fetal and maternal plasma. Sixlate pregnant ewes and their fetuses were instrumented to access arterial andvenous circulations. Intravenous boluses of 155 mol of L-arginine-HCl or Lcitrullineper kg body weight were administered to each ewe. Administration ofcitrulline was more effective than arginine in achieving a sustained increase inconcentrations of arginine in maternal and fetal blood. Accordingly, theclearance rate of citrulline was lower and its biological half-life in maternal bloodgreater, when compared with arginine. The second experiment determined ifadministration of arginine to underfed ewes is effective in ameliorating orpreventing IUGR. Ewes were fed either 100% or 50% of the National ResearchCouncil recommended nutrient requirements for pregnant sheep. Between Day60 of pregnancy and parturition control-fed ewes received saline solution and underfed ewes received either saline solution or L-arginine-HCl solution (155mol of arginine/kg body weight) intravenously three times daily (n=5 / treatmentgroup). Birth weights of lambs were lower in saline-infused underfed ewes.There was no difference in birth weights of lambs from control-fed and argininetreatedunderfed ewes. The third experiment determined whether administrationof arginine could improve survival rates of lambs and enhance fetal growth inewes carrying multiple fetuses. Between Days 100 and 121 of pregnancy, ewesreceived an intravenous infusion of either saline solution (n= 14) or L-arginine-HCl solution (345 mol of arginine/kg body weight, n=20) three times daily.Parenteral administration of arginine increased the percentage of lambs bornalive and enhanced the birth weights of quadruplets. Collectively, these resultsindicate that 1) parenteral administration of arginine improves pregnancyoutcomes in underfed and prolific ewes; and 2) the use of arginine or citrullinemay have important implications for the design of an effective treatment forpreventing or ameliorating IUGR in mammals.

Fetal growth in utero depends on nutrient and oxygen reaching the fetus through the uterine and placental microcirculations, both undergoing massive expansion during pregnancy. Aberrations of the placental vasculature are associated with Intrauterine Growth Restriction (IUGR), a common pathological outcome of pregnancy; however, the cellular components responsible for vessel formation in the placenta and the uterus remain unknown. Endothelial Progenitor Cells (EPC) are a group of morphologically and functionally varied bone marrow derived vasculogenic cell types, divided into two major subsets: (i) Circulating Angiogenic Cells (CACs), which promote vessel formation by interfering with the extracellular matrix and (ii) Endothelial Colony Forming Cells (ECFCs), which provide the source for new endothelium. This role has been demonstrated in pathophysiological studies, but not in normal physiological events in vivo. Fetal ECFCs are more proficient than their adult counterparts, but it is unclear in what specific fetal or maternal physiological situations fetal ECFCs are involved. Based upon these considerations, it was hypothesised that: (i) fetal-derived ECFCs play a role in placental vasculogenesis, (ii) these cells transmigrate the placenta and home to loci of vessel formation in the pregnant uterus, and that (iii) intrinsic alterations in their capabilities are associated with fetal growth restriction during intrauterine life. To support these hypotheses the following experiments were performed;(i) EPCs in blood from pairs of human umbilical arteries and veins were counted by flow cytometry. Numbers of EPCs in these samples showed an arterio-venous gradient suggesting their placental sequestration. Furthermore, ECFCs were isolated from human umbilical blood using established culture techniques. Labelled human fetal ECFCs were transplanted into the circulation of murine fetuses using an ultrasound-guided intra-cardiac injection. Using a fluorescent imager and microscopy these cells were shown to home to the murine placenta and participate in vasculogenesis.(ii) Male mice ubiquitously expressing eGFP were crossbred with native females, and fetal (eGFP-positive) endothelial-like cells integrated into the uterine microvasculature. Human fetal ECFCs injected into murine fetuses were shown to migrate to the maternal uterus and became functionally involved with the microvasculature. In humans, microvessels were isolated from uterine biopsies of mothers with male offspring. Copies of the male specific SRY gene (quantified by RT-QPCR) indicated that cells of fetal origin constituted 12% of the endothelium in these vessels. In cross-sections, hybridisation of the Y-chromosome demonstrated the presence of fetal cells in the maternal endothelium of the human uterus. (iii) Using flow cytometry, fewer EPCs were defined within the peripheral circulation of growth-restricted babies. Functional assays showed that ECFCs derived from these growth-restricted cases had intrinsically impaired proliferation, migration, matrix-metalloproteinase (MMP-2) production, and generated fewer blood vessels in a murine vasculogenic bioassay. These results demonstrated the vasculogenic capacity of human fetal ECFCs in vivo and established them as key players in human placental vasculogenesis and uterine vessel expansion. Notably, these results also showed a link between impaired function of fetal ECFCs and IUGR, which is associated with increased cardiovascular risk of both the fetus as an adult, and mother in later life. From these findings it could be speculated, that intrinsic changes in ECFC-biology may be the causative link between IUGR and fetal and maternal cardiovascular susceptibility. Insight into these processes may contribute to early diagnosis, prevention and treatment of IUGR and associated conditions.

We established that acute adrenergic receptor stimulation in β-cells suppresses oxidative metabolism. This effect provides the basis for understanding how CAs reduce cell proliferation. Furthermore, the effects of acute CA on Min6 cells were distinguished from chronic CA culture using proteomics. Together, the RNAseq, qPCR and proteomic studies support a role for adrenergic receptor signaling in the regulation of proliferaton in β-cells. This work describes the genetic and proteomic profile underlying chronic adrenergic signaling and identifies CA independent suppression of β-cell growth and metabolism. Through the use of multiple models and comparative bioinformatics, we refined the list of molecular dysfunctions associated with the IUGR pathology to a set of specific and testable adrenergic targets.

Current research spans a wide range of objectives whose diversity includes the understanding of global epidemiology and the detailing of molecular interactions leading to specific pathologies. This work aligns more closely with the goal of mechanistic clarity by elucidating several aspects of signaling pathways involved in inflammatory and obstetric pathologies. Prior research has confirmed the role of Receptors for Advanced Glycation End-Products (RAGE) activation in signaling leading to chronic inflammation such as that observed in chronic obstructive pulmonary disease (COPD). RAGE activation has also been identified in other disease states including diabetes, Alzheimer’s disease, osteoarthritis, and cancers. We examined the role of RAGE in the obstetric complication intrauterine growth restriction (IUGR) wherein fetal development is delayed and infants are born at low birthweight. Exposure to tobacco smoke is known to activate RAGE, and smoke exposure also increases risk for IUGR. We confirm a role for RAGE signaling in development of IUGR. RAGE inhibition by semi-synthetic glycosaminoglycan ethers (SAGEs) significantly improved fetal and placental weights and reduced inflammatory signaling molecules. Interactions between RAGE and other signaling pathways have been noted in several research endeavors, and we sought to further understand signaling interactions specifically in obstetric pathologies by examining relationships between RAGE and Gas6/AXL signaling. We confirm that RAGE and Gas6/AXL signaling are not independent. Using tobacco smoke as a means of inducing RAGE, we determined that total AXL is inhibited when RAGE is active, but that phosphorylated AXL is increased. Inhibition of RAGE also increased Gas6 expression. These interactions require further clarification, but provide a foundation to expand upon. We further studied interactions within the Gas6/AXL pathway independent of RAGE. High levels of Gas6 have been noted in the serum of some women with preeclampsia, and early diagnosis and treatment of preeclampsia are currently limited. We demonstrate that, in a rat model, administration of Gas6 during pregnancy is sufficient to induce symptoms of preeclampsia including high blood pressure, increased proteinuria, and decreased trophoblast invasion. This provides a novel model which will further both diagnosis and treatment of preeclampsia. We also demonstrated that trophoblast invasion is influenced in a cell-type dependent manner by Gas6 and mTOR signaling, with decreased trophoblast invasion when Gas6 is high in trophoblast cells, but increased invasion with high Gas6 in a pulmonary adenocarcinoma cell type and in oral squamous cell carcinoma cells. Our work has clarified details of both RAGE and Gas6/AXL signaling that are crucial to further study of the pathways in which they are active, and the pathologies resulting from signaling misregulation.

Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-08-21T18:59:25Z No. of bitstreams: 1 SilviaSousa.pdf: 2280503 bytes, checksum: a06b53b8d68a96973316e3b881bd15d6 (MD5) / Made available in DSpace on 2017-08-21T18:59:25Z (GMT). No. of bitstreams: 1 SilviaSousa.pdf: 2280503 bytes, checksum: a06b53b8d68a96973316e3b881bd15d6 (MD5) Previous issue date: 2017-02-22 / Introduction: Intrauterine growth restriction (IUGR) and preterm birth (PT) are considered to be public health problems in developing countries. The occurrence of catch-up favors the ability of these infants to obtain equivalent growth to that of infants born without IUGR and at term. Objective: To assess the influence of IUGR and of PT on the occurrence of catch-up in weight and BMI in schoolchildren from two birth cohorts from cities with contrasting socioeconomic conditions in the Northeast and Southeast of Brazil. Method: A total of 1,463 children were studied, from whom information was collected at birth and at school age in 1994 and 2004/2005 in Ribeirão Preto, SP (RP) and in 1997/1998 and 2005/2006 in São Luís, MA (SL). The response variable was defined as the difference in weight and BMI between the Z-score of the schoolchild and the Z-score at birth. A change in Z-score ≥ 0.67 was considered to be catch-up. The explanatory variable was divided into four categories: without IUGR and at term (NIUGR-T), only IUGR (IUGR-T), only PT (NIUGR-PT), and PT plus IUGR (IUGR-PT). Estimates of the relative risk for catch-up in weight were obtained by logistic regression in separate models for each city. Results: RP children had a greater proportion of both catch-up than SL children. In RP, 90.8% of IUGR-PT and 70.8% of NIUGR-PT (it was more frequent in pre-terms, restricted or not) caught up in weight at school age. In SL, the NIUGR-PT and IUGR-T caught up in a similar way. There was no difference between genders. Regarding marital status, in RP, no difference was found, however, in SL, the odds of catching up at 7 years old was 65% lower for those schoolchildren whose mothers did not have a partner. Having only one child, both in RP and in SL, increased almost twofold (OR=1.89 in RP and 1.83 in SL) the odds of the schoolchild catching up; and receiving up to 5 times the monthly minimum wage decreased by 50% the odds of catching up in SL, although no difference was found in RP. The head of the family’s occupation being unqualified manual labor or unemployed decreased by half the odds of catching up in both cities. Maternal age and education level were not associated to catchup in school age. Conclusion: In both cities, children born preterm with/without IUGR had a greater proportion of catch-up in weight and without IUGR and at term in BMI. / Introdução: A restrição de crescimento intrauterino (RCIU) e o nascimento pré-termo (PT) são considerados problemas de saúde pública nos países em desenvolvimento. A ocorrência de catch-up propicia que estes consigam equiparar seu crescimento ao das crianças nascidas sadias. Objetivo: Avaliar a influência da RCIU e do PT na ocorrência de catch-up de peso e IMC em escolares de duas coortes de nascimentos de cidades com condições socioeconômicas contrastantes. Método: Foram estudadas 1.463 crianças, cujas informações foram coletadas ao nascer e na idade escolar em 1994 e 2005/06 em Ribeirão Preto, SP (RP) e em 1997/98 e 2005/06 em São Luís, MA (SL). A variável resposta foi definida pela diferença entre o escore z do escolar e escore z ao nascimento do peso e IMC. Considerou-se como catch-up uma mudança de escore z de ≥ 0,67. A variável explanatória foi dividida em quatro categorias: sem RCIU e a termo (TNR), só RCIU (TR), só PT (PTNR) e PT com RCIU (PTR). Estimativas do risco relativo para catch-up de peso foram obtidas por regressão logística em modelos separados por cidade. Resultados: O fenômeno “catch-up” tanto de peso quanto de IMC foi mais evidente em RP para todas as categorias das chamadas condições de nascimento. Para ambas as cidades a maior incidência de catch-up de peso se deu para os PT e/ou com RCIU, já o de IMC para os TNR. Não houve diferença entre os sexos. Ter somente 1 filho, maior renda familiar e escolaridade materna além da ocupação do chefe mais qualificada aumentou a frequência do catch-up de peso e IMC em ambas as cidades. Conclusão: Não só condições biológicas ao nascer mas também as condições de vida, tais como, acesso aos serviços de saúde e melhor oferta de alimentos nas idades mais precoces da criança influenciam na ocorrência de catch-up de peso e IMC nas duas cidades estudadas.

Η ενδομήτρια καθυστέρηση ανάπτυξης ορίζεται ως παθολογική μείωση του ρυθμού εμβρυικής ανάπτυξης που καταλήγει σε ένα έμβρυο το οποίο δεν έχει την αναμενόμενη ανάπτυξη σύμφωνα με την ηλικία κύησης και το οποίο διατρέχει κίνδυνο αυξημένης περιγεννητικής νοσηρότητας και θνησιμότητας. Ενδομήτρια καθυστέρηση ανάπτυξης είναι η ανικανότητα του εμβρύου να διατηρήσει τον αναμενόμενο ρυθμό ανάπτυξης ανεξάρτητα αν το βάρος του είναι κάτω από τη 10η εκατοστιαία θέση. Όταν η ανάπτυξη του εμβρύου είναι κάτω από την 5η εκατοστιαία θέση τότε ίσως να μπορεί να θεωρηθεί πραγματική ενδομήτρια καθυστέρηση ανάπτυξης. Σύμφωνα με το αμερικανικό κολέγιο γυναικολόγων και μαιευτήρων American College of Obstetricians and Gynecologists (ACOG) η ενδομήτρια καθυστέρηση ανάπτυξης ορίζεται ως το έμβρυο που αποτυγχάνει να έχει τον αναμενόμενο ρυθμό ανάπτυξης. Πολλές φορές οι όροι ενδομήτρια καθυστέρηση ανάπτυξης (IUGR) και μικρό για την ηλικία κύησης (SGA) συγχέονται και για αυτό το λόγο διευκρινίζεται ότι ο όρος μικρό για την ηλικία κύησης (SGA) αναφέρεται σε έμβρυο του οποίου το εκτιμώμενο βάρος είναι κάτω από τη 10η εκατοστιαία θέση. Από το σύνολο των μικρών για την ηλικία κύησης (SGA) εμβρύων το 40% είναι υγιή, 20% είναι μικρά εξαιτίας χρωμοσωμικών και περιβαλλοντικών παραγόντων και 40% διατρέχουν ιδιαίτερα αυξημένο κίνδυνο ενδομήτριου θανάτου και σχετίζονται με ενδομήτρια καθυστέρηση ανάπτυξης. Η ενδομήτρια καθυστέρηση ανάπτυξης είναι μια πολυσυστηματική διαταραχή και διακρίνεται σε: Α) Συμμετρική. Όταν η ανάπτυξη της κεφαλής και της κοιλιάς επιβραδύνονται συμμετρικά. Είναι λιγότερο συχνή, 20%-30%. Β) Ασύμμετρη. Δυσανάλογη ελάττωση του μεγέθους της κοιλιάς σε σχέση με αυτό της κεφαλής. Είναι περισσότερο συχνή, 70%-80%, και οφείλεται συνήθως σε μητροπλακουντιακή ανεπάρκεια και συμβαίνει μετά την 28η εβδομάδα. Στη φάση αυτή γίνεται η μεγαλύτερη εναπόθεση λίπους. Η ενδομήτρια καθυστέρηση ανάπτυξης αποτελεί κύριο πρόβλημα στην περιγεννητική ιατρική, είναι η ΔΕΥΤΕΡΗ αιτία θανάτου μετά την προωρότητα. 52% των ανεξήγητων ξαφνικών θανάτων των εμβρύων συσχετίζονται με ανάπτυξη IUGR. 10% των περιπτώσεων περιγεννητικής θνησιμότητας στην Ευρώπη είναι αποτέλεσμα μη διαγνωσμένης IUGR. Η επίπτωση της ενδομήτριας καθυστέρησης ανάπτυξης είναι 8% στον γενικό πληθυσμό. / Intrauterine growth restriction (IUGR) is the failure of the fetus to achieve his/her intrinsic growth potential and is associated with significantly increased perinatal morbidity and mortality. IUGR affects 10% of pregnancies and perinatal mortality rates are 4-8 times higher for infants with this disorder. Intrauterine growth restriction is not a specific disease entity with a unique pathophysiology, but the result of suboptimal intrauterine growth conditions in conjunction with a variety of disorders from genetic to metabolic, vascular, coagulative, autoimmune, as well as infectious. Newborns with intrauterine growth restriction (IUGR) present reduced fat mass and undergo adaptational changes of endocrine/metabolic mechanisms as a result of intrauterine malnutrition. Recently, it was shown that fat-secreted adipokines such as visfatin, a novel adipokine improving glucose tolerance through insulin-mimetic effects, and vaspin , profoundly influence insulin sensitivity and energy metabolism.

Introdução: Nos seres humanos, a adversidade fetal está associada com escolhas alimentares menos saudáveis na idade adulta. Sabe-se que um menor crescimento fetal está relacionado à maior preferência por alimentos palatáveis e ao risco de obesidade. Ácidos graxos docosahexanoicos (DHA, ácidos graxos poli-insaturados ômega-3 - n-3 PUFAs) modulam o funcionamento do sistema mesolímbico dopaminérgico, envolvido nesse comportamento. Em ratos, nosso grupo evidenciou que o estresse neonatal interage com deficiência dietética leve de n-3 PUFAs, aumentando o risco para obesidade, resistência à insulina, precedido por hiperfagia na adolescência. Considerando o baixo peso ao nascer como marcador de exposição ao estresse metabólico crônico fetal, hipotetizou-se que o consumo de n-3 PUFAs pode interagir com o peso ao nascer e influenciar o comportamento alimentar. Objetivo: Verificar em dois estudos diferentes se o consumo habitual de n-3 PUFAs interage com o crescimento fetal (RCIU) e se interfere no comportamento alimentar e nos aspectos de sua regulação central em crianças e adolescentes/adultos jovens. Métodos: No estudo 1, a amostra incluiu 75 crianças das cidades de Montreal, Québec e Hamilton, Ontário, Canadá. Os participantes foram recrutados de uma coorte prospectiva de nascimentos já estabelecida (projeto MAVAN). O crescimento fetal foi com base na razão de peso ao nascer (BWR, peso ao nascer/média do peso ao nascer sexo-específica para cada idade gestacional da população local). Consideraram-se, tendo restrição de crescimento intrauterino (RCIU), as crianças com BWR<0,85. Aos 48 meses de idade, as mães preencheram um questionário de frequência alimentar; e, aos 72 meses, o Children’s Eating Behavior Questionnaire (CEBQ). Um modelo de regressão linear (General Linear Model - GLM) foi utilizado para avaliar a relação entre a RCIU e o consumo de n-3 PUFAs, aos 48 meses, e seu efeito nos escores do CEBQ, aos 6 anos de idade, considerando significativo um p<0,05. O projeto foi aprovado pelo Research Ethical Board do Douglas Mental Health Research Institute (n° 03/45). No estudo 2, a amostra incluiu 48 adolescentes/adultos jovens de Porto Alegre, RS. Os participantes foram recrutados de uma coorte prospectiva comunitária (projeto PROTAIA). A avaliação do crescimento fetal foi com base na BWR, e aqueles do tercil inferior da distribuição BWR foram considerados como RCIU. A concentração sérica de DHA (medida objetiva da ingestão de n-3 PUFAs) foi identificada por cromatografia gasosa. Os participantes preencheram o Dutch Eating Behaviour Questionaire (DEBQ). Um GLM foi realizado para avaliar a correlação entre a RCIU e o consumo de n-3 PUFAs e seu efeito nos escores do DEBQ, considerando significativo um p<0,05. As análises de Ressonância Magnética Funcional (fMRI), numa tarefa de visualização de alimentos palatáveis, não palatáveis e objetos neutros, tiveram como desfecho a ativação cerebral; e, como preditores, os valores contínuos dos níveis séricos de DHA e o BWR, utilizando uma regressão múltipla (FWE corrigido para comparações múltiplas com um p<0,05). O projeto foi aprovado pelo Comitê de Ética em Pesquisa do Hospital de Clínicas de Porto Alegre (n°12-0254). Resultados: No estudo 1, havia 40 meninas e 35 meninos. Não foram encontradas diferenças no consumo de n-3 PUFAs e outras variáveis de confusão entre indivíduos RCIU e não RCIU. No entanto, o GLM predizendo a “seletividade alimentar” aos 72 meses demonstrou uma interação significativa entre n-3 PUFAs e status de RCIU (sim/não) [Wald= 8,516; df=1; e p=0,004], com maior consumo sendo associado à diminuição da “seletividade alimentar” em crianças com RCIU. Não foram observados efeitos em outros domínios do CEBQ. No estudo 2, para a maioria das análises, havia 31 meninas e 16 meninos. Não foram encontradas diferenças nos níveis séricos de DHA e nas outras variáveis de confusão entre indivíduos RCIU e não RCIU. Somente o grupo com RCIU apresentou médias de peso ao nascer e do escore Z do IMC menores, quando comparado ao grupo não RCIU (p<0,0001 e p=0,046, respectivamente). O GLM predizendo “ingestão externa” evidenciou uma interação significativa entre a concentração sérica de DHA e status da RCIU (sim/não) [Wald=5,845; df=1; e p=0,016], com maiores níveis de DHA, sendo associados à diminuição do escore desse domínio em indivíduos com RCIU. Não foi observado efeito no domínio do DEBQ “ingestão emocional”, enquanto a “ingestão restritiva” não alcançou significância estatística [Wald=3,360; df=1; e p=0,067]. Na fMRI, tendo como preditores positivos e negativos, respectivamente, os níveis séricos de DHA e a razão de peso ao nascer (BWR), no contraste alimentos palatáveis>itens neutros, foi encontrada ativação cerebral no giro frontal superior direito (p corrigido=0,034). Ainda para esse contraste, tendo como preditor negativo apenas o BWR, a mesma região foi ativada (p corrigido=0,028), e ao considerar como preditores negativos ambos os níveis séricos de DHA e BWR, também foi encontrada ativação na mesma região cerebral (p corrigido=0,025). Os resultados de neuroimagem demonstraram que o BWR é um preditor mais importante, determinando, portanto, a ativação nessa região. Em outras palavras, quanto menor o BWR maior a ativação dessa região envolvida em controle de impulsos/tomada de decisão frente à visualização de imagens de alimentos palatáveis. Conclusões: Sugere-se que a restrição de crescimento intrauterino modula a ativação cerebral frente a estímulos relacionados a alimentos palatáveis, ativando uma área relacionada a controle de impulsos (giro frontal superior). Além disso, maior consumo de n-3 PUFAs pode proteger indivíduos com RCIU de comportamentos inadequados em diferentes idades, podendo beneficiar o comportamento alimentar infantil, bem como na adolescência/vida adulta, diminuindo a ingestão externa em resposta a estímulos alimentares externos. / Introduction: In humans, fetal adversity associates with less healthy food choices in adulthood. It is known that poor fetal growth is associated with an increased preference for palatable foods and obesity risk. Docosahexaenoic fatty acids (DHA, polyunsaturated fatty acids omega-3 - n-3 PUFAs) modulate the functioning of the dopamine mesolimbic system, which is involved in this behavior. In rats, our group showed that neonatal stress interacts with a mild dietary deficiency in n-3 PUFAs and increases the risk for obesity and insulin resistance, preceded by hyperphagia during adolescence. Considering low birth weight as a marker of chronic metabolic stress exposure, we hypothesized that n-3 PUFAs consumption could interact with birth weight and affect feeding behavior. Objective: We investigated in two different studies if the habitual consumption of n-3 PUFAs interacts with fetal growth (IUGR) and affects feeding behavior and aspects of their central regulation in children and adolescents/young adults. Methods: In study 1, the sample included 75 children from the city of Montreal, Quebec, and Hamilton, Ontario, Canada. Participants were recruited from an established prospective birth cohort (MAVAN project). Fetal growth was based on the birth weight ratio (BWR, birth weight/sex-specific mean birth weight for each gestational age), and children were considered intrauterine growth restricted (IUGR) if BWR<0.85. At 48-months of age, mothers completed a Food Frequency Questionnaire and at 72 months the Children’s Eating Behavior Questionnaire (CEBQ). A linear regression model (General Linear Model – GLM) was used to evaluate the correlation between IUGR and n-3 PUFAs consumption at 48 months and its effect on CEBQ scores at 6 years of age, considering statistically significant a p<0.05. The project was approved by the Research Ethical Board of the Douglas Mental Health Research Institute (n° 03/45). In study 2, the sample included 48 individuals from Porto Alegre, RS. Participants were recruited from a prospective communitarian cohort (PROTAIA project). Fetal growth was based on the BWR, and those in the lower tertile of the BWR distribution were considered IUGR. Serum DHA concentration (objective measure of n-3 PUFAs intake) was identified by gas chromatography. Participants filled out a Dutch Eating Behaviour Questionnaire (DEBQ). A General Linear Model (GLM) was used to evaluate the correlation between IUGR and serum DHA concentration and its effect on DEBQ scores, considering statistically significant a p<0.05. The Functional Magnetic Resonance Imaging (fMRI) analyzes in a task facing the visualization of palatable and non-palatable foods, as well as neutral objects had brain activation as the outcome, and the serum levels of DHA and BWR as continuous predictors, using a multiple regression (FWE corrected for multiple comparisons with p<0.05). The project was approved by the Research Ethical Board of the Hospital de Clínicas de Porto Alegre (n°12-0254). Results: In study 1, there were 40 girls and 35 boys. No differences were found on n-3 PUFAs consumption and other confounding variables between IUGR and non-IUGR individuals. However, the GLM model predicting food fussiness at 72 months showed a significant interaction between n-3 PUFAs and IUGR status (yes/no) [Wald= 8.516; df=1; p=0.004], with higher intakes being associated with decreased risk for food fussiness in IUGR children only. No effects were seen on the other domains of the CEBQ. In study 2, for most of the analyzes there were 31 girls and 16 boys. There were no differences in serum levels of DHA and other confounding variables between IUGR and non-IUGR individuals. However, the group with IUGR showed lower birth weight mean and BMI Z score when compared to the non-IUGR group (p<0.0001 and p=0.046, respectively). The GLM model predicting external eating showed a significant interaction between serum DHA concentration and IUGR status (yes/no) [Wald=5.845; df=1; p=0.016], with higher serum DHA concentration being associated with decreased external eating in the IUGR individuals. No effects were seen in the DEBQ domain emotional eating, while restrictive eating did not reached statistical significance [Wald=3.360; df=1; p=0.067]. In the fMRI, having as positive and negative predictors the serum DHA concentration and BWR respectively, in the contrast palatable foods>neutral objects we found an activation in the right superior frontal gyrus (p corrected=0.034). In this contrast, using only BWR as a negative predictor, the same area was activated (p corrected=0.028), and when considering as two negative predictors (serum DHA concentration and BWR), activation was found in the same brain region (p corrected=0.025). The fMRI results showed that BWR is a more important predictor determining activation of this brain region. In other words, the lower BWR (more IUGR), the more activation in this area involved in impulse control/decision making facing the visualization of palatable foods´ images. Conclusion: We suggest that IUGR modulates the brain activity facing stimuli related to palatable foods, activating an area related to impulse control (superior frontal gyrus). Moreover, higher intake of n-3 PUFAs can protect individuals with IUGR from inappropriate behaviors at different ages, decreasing food fussiness and the external eating in response to external food cues.

Objetivo: Verificar os efeitos do tabagismo materno durante a gestação sobre o crescimento de lactentes nos seis primeiros meses de vida. Métodos: Estudo observacional longitudinal, utilizando amostra de conveniência de recém-nascidos (RN), divididos em três grupos: filhos de mães tabagistas, àqueles com restrição de crescimento intrauterino idiopático (RCIU) e um grupo controle. A amostra foi selecionada em dois hospitais de Porto Alegre, capital estadual situada no extremo sul do Brasil, no período de 2011 a 2014. Os recém-nascidos foram avaliados ao nascimento, aos 7 e 15 dias, no primeiro, terceiro e sexto mês. As medidas antropométricas utilizadas foram peso, comprimento, perímetro cefálico e dobras cutâneas. Os indicadores de crescimento utilizados foram expressos em escore-z (OMS). As análises foram realizadas pelo método de Equações de Estimativas Generalizadas. Resultados: A amostra foi composta por 194 duplas mãe/recém-nascidos: 71 no grupo tabaco, 23 no grupo RCIU e 100 no grupo controle. Em relação ao peso ao nascer, o grupo tabaco apresentou menor média em comparação ao controle (p=0,002) e o grupo RCIU diferiu de ambos (p<0,001). Comprimento ao nascer do grupo tabaco e controle foram semelhantes, porém o grupo RCIU foi menor que ambos (p<0,001). Não houve diferença na trajetória de crescimento entre o grupo tabaco e controle, porém foram verificadas diferenças no crescimento do grupo RCIU em relação aos demais. Conclusão: A restrição de crescimento intrauterino mostrou ter maior impacto sobre a trajetória de crescimento dos lactentes estudados, independente de outros fatores, como o fumo e a alimentação. / Objective: To investigate the effects of maternal smoking during pregnancy on the growth of infants in the first six months of life. Methods: Longitudinal observational study using a convenience sample of newborns (NBs) divided into three groups: infants of smoking mothers (tobacco), with idiopathic intrauterine growth restriction (IUGR), and a control group. The sample was selected from two hospitals in Porto Alegre, located in southern Brazil, between 2011 and 2014. NBs were evaluated at birth, 7 and 15 days, and in the first, third, and sixth month. Anthropometric measures were weight, length, head circumference, and skinfold thickness. The growth indicators used were expressed as z-scores (WHO). The analyses were performed using the generalized estimating equation method. Results: The sample included 194 mother/newborn pairs: 71 tobacco group, 23 IUGR group, and 100 control group. In terms of weight at birth, tobacco was lower than that of the control (p=0.002) and the IUGR had a statistically significant difference when compared with both the other groups (p<0.001). The birth length tobacco and control groups were similar, but the IUGR group was lower than both (p <0.001). We found no differences in growth trajectory between tobacco and control group, but there were differences in the growth of the IUGR group when compared with the other groups. Conclusion: Intrauterine growth restriction had major impact on the growth trajectory of the infants studied, regardless of other factors, such as smoking and diet.