Offspring Brain Research Articles

STZ-induced gestational diabetes exposure alters PTEN/AKT/mTOR-mediated autophagy signaling pathway leading to increase the risk of neonatal hypoxic-ischemic encephalopathy

Exposure to gestational diabetes mellitus (GDM) during pregnancy has significant consequences for the unborn baby and newborn infant. However, whether and how GDM exposure induces the development of neonatal brain hypoxia/ischemia-sensitive phenotype and the underlying molecular mechanisms remain unclear. In this study, we used a late GDM rat model induced by administration of streptozotocin (STZ) on gestational day 12 and investigated its effects of GDM on neonatal brain development. The pregnant rats exhibited increased blood glucose levels in a dose-dependent manner after STZ administration. STZ-induced maternal hyperglycemia led to reduced blood glucose levels in neonatal offspring, resulting in growth restriction and an increased brain to body weight ratio. Importantly, GDM exposure increased susceptibility to hypoxia/ischemia (HI)-induced brain infarct sizes compared to the controls in both male and female neonatal offspring. Further molecular analysis revealed alterations in the PTEN/AKT/mTOR/autophagy signaling pathway in neonatal male offspring brains, along with increased ROS production and autophagy-related proteins (Atg5 and LC3-II). Treatment with the PTEN inhibitor bisperoxovanadate (BPV) eliminated the differences in HI-induced brain infarct sizes between the GDM-exposed and the control groups. These findings provide novel evidence of the development of a brain hypoxia/ischemia-sensitive phenotype in response to GDM exposure and highlight the role of the PTEN/AKT/mTOR/autophagy signaling pathway in this process.

An investigation of the endoplasmic reticulum stress in obesity exposure in the prenatal period

ObjectivesExposure to maternal obesity has been shown to make offspring more prone to cognitive and metabolic disorders later in life. Although the underlying mechanisms are unclear, the role of endoplasmic reticulum (ER) stress in the fetal programming process is remarkable. ER stress can be activated by many chronic diseases, including obesity and diabetes. Therefore, our study aimed to investigate the role of ER stress caused by maternal diet-induced obesity in the offspring hippocampus. We also evaluated the protective effect of N-acetylcysteine (NAC) against ER stress. MethodsA rat obesity model was created by providing a high-fat (60 % kcal) diet. N-acetylcysteine (NAC) was administered at a dosage of 150 mg/kg via the intragastric route. The animals were mated at the age of 12 weeks. The same diet was maintained during pregnancy and lactation. The experiment was terminated on the postnatal 28th day, and the offspring's brain tissues were examined. Immunohistochemical staining for ER stress markers was performed on sections taken from tissues after routine histological procedures. ResultsThe results revealed increased GRP78, PERK, and eIF2α immunoreactivities in the hippocampal dentate gyrus (DG) and cornu ammonis 1 (CA1) regions in the obese group offspring, while the expression of those markers in those regions normalized with NAC supplementation (p < 0.01). Statistical analysis of XBP1 immunoreactivity H-scores revealed no difference between the study groups (p > 0.05). DiscussionThese results suggest that exposure to obesity during the prenatal period may cause increased ER stress in hippocampal neurons, which have an important role in the regulation of learning, memory and behavior, and this may contribute to decreased cognitive performance. On the other hand, NAC stands out as an effective agent that can counteract hippocampal ER stress.

MiR-377-3p Regulates Hippocampal Neurogenesis via the Zfp462-Pbx1 Pathway and Mediates Anxiety-Like Behaviors in Prenatal Hypoxic Offspring.

Prenatal hypoxia (PH) is one of the most common complications of obstetrics and is closely associated with many neurological disorders such as depression, anxiety, and cognitive impairment. Our previous study found that Zfp462 heterozygous (Het) mice exhibit significant anxiety-like behavior. Interestingly, offspring mice with PH also have anxiety-like behaviors in adulthood, accompanied by reduced expression of Zfp462 and increased expression of miR-377-3p; however, the exact regulatory mechanisms remain unclear. In this study, western blotting, gene knockdown, immunofluorescence, dual-luciferase reporter assay, immunoprecipitation, cell transfection with miR-377-3p mimics or inhibitors, quantitative real-time PCR, and rescue assay were used to detect changes in the miR-377-3p-Zfp462-Pbx1 (pre-B-cell leukemia homeobox1) pathway in the brains of prenatal hypoxic offspring to explain the pathogenesis of anxiety-like behaviors. We found that Zfp462 deficiency promoted Pbx1 protein degradation through ubiquitination and that Zfp462 Het mice showed downregulation of the protein kinase B (PKB, also called Akt)-glycogen synthase kinase-3β (GSK3β)-cAMP response element-binding protein (CREB) pathway and hippocampal neurogenesis with anxiety-like behavior. In addition, PH mice exhibited upregulation of miR-377-3p, downregulation of Zfp462/Pbx1-Akt-GSK3β-CREB pathway activity, reduced hippocampal neurogenesis, and an anxiety-like phenotype. Intriguingly, miR-377-3p directly targets the 3'UTR of Zfp462 mRNA to regulate Zfp462 expression. Importantly, microinjection of miR-377-3p antagomir into the hippocampal dentate gyrus of PH mice upregulated Zfp462/Pbx1-Akt-GSK3β-CREB pathway activity, increased hippocampal neurogenesis, and improved anxiety-like behaviors. Collectively, our findings demonstrated a crucial role for miR-377-3p in the regulation of hippocampal neurogenesis and anxiety-like behaviors via the Zfp462/Pbx1-Akt-GSK3β-CREB pathway. Therefore, miR-377-3p could be a potential therapeutic target for anxiety-like behavior in prenatal hypoxic offspring.

Paternal immune activation by Poly I:C modulates sperm noncoding RNA profiles and causes transgenerational changes in offspring behavior

Paternal pre-conceptual environmental experiences, such as stress and diet, can affect offspring brain and behavioral phenotypes via epigenetic modifications in sperm. Furthermore, maternal immune activation due to infection during gestation can reprogram offspring behavior and brain functioning in adulthood. However, the effects of paternal pre-conceptual exposure to immune activation on the behavior and physiology of offspring (F1) and grand-offspring (F2) are not currently known. We explored effects of paternal pre-conceptual exposure to viral-like immune activation on F1 and F2 behavioral and physiological phenotypes using a C57BL/6J mouse model. Males were treated with a single injection (intraperitoneal) of the viral mimetic polyinosinic:polycytidylic acid (Poly I:C: 12 mg/kg) then bred with naïve female mice four weeks after the Poly I:C (or 0.9% saline control) injection. The F1 offspring of Poly I:C treated fathers displayed increased depression-like behavior in the Porsolt swim test, an altered stress response in the novelty-suppressed feeding test, and significant transcriptomic changes in their hippocampus. Additionally, the F1 male offspring of Poly I:C treated F0 males showed significantly increased immune responsivity after a Poly I:C immune challenge (12 mg/kg). Furthermore, the F2 male grand-offspring took longer to enter and travelled significantly shorter distances in the light zone of the light/dark box. An analysis of the small noncoding RNA profiles in sperm from Poly I:C treated males and their male offspring revealed significant effects of Poly I:C on the sperm microRNA content at the time of conception and on the sperm PIWI-interacting RNA content of the male offspring. Notably, eight miRNAs with an FDR < 0.05 (miR-141-3p, miR-126b-5p, miR-669o-5p, miR-10b-3p, miR-471-5p, miR-463-5p, miR-148b-3p, and miR-181c-5p) were found to be significantly downregulated in the sperm of Poly I:C treated males. Collectively, we demonstrate that paternal pre-conceptual exposure to a viral immune challenge results in both intergenerational and transgenerational effects on brain and behavior that may be mediated by alterations in the sperm small noncoding RNA content.

FRI386 Effects Of Maternal Sucrose Intake During Pregnancy On Steroids In The Placenta And Fetal Brain Of Rats

Abstract Disclosure: M.M. Jung: None. D.R. Seib: None. H.W. Chen: None. M. Idrissi: None. K.K. Soma: None. Intake of added sugars such as sucrose (table sugar) is high globally. Many people consume more than 20% of their daily calories as added sugars. High-sucrose consumption alters steroids and the brain. In rats, a human-relevant level of maternal sucrose intake starting 10 weeks before, during, and after pregnancy decreases maternal corticosterone in the serum but increases corticosterone in the blood and brain of the adult female offspring. Similarly, rat dams fed a high-sucrose diet starting 10 weeks before and during gestation have elevated 11-dehydrocorticosterone (DHC) in the serum and amniotic fluid and reduced testosterone and androstenedione in the labyrinth/junctional zone and decidua, respectively. Aldosterone is also elevated in the amniotic fluid, fetal blood, and fetal brain (nucleus accumbens, NAc). Thus, it is clear that maternal sucrose intake alters both maternal and offspring steroids, and has long-term, sex-specific endocrine effects. However, it is unclear how maternal sucrose consumption specifically during pregnancy impacts the offspring development. Our study investigates how maternal sucrose intake during pregnancy affects steroids in the placenta and fetal brain. We hypothesize that maternal sucrose intake is a metabolic stressor that will alter steroid signalling in the placenta and the developing brain. We fed female Long-Evans rats either a high-sucrose diet (26% kcal sucrose) or an isocaloric, macro/micro-nutrient-matched control diet (1% kcal sucrose) starting embryonic day 0 (E0; the day of pregnancy confirmation) (n=15/group). On E19, we collected maternal serum, amniotic fluid, placenta, fetal blood, and fetal brain. We will microdissect the placenta (decidua and labyrinth/junctional zone) and fetal brain (prefrontal cortex, NAc, ventral tegmental area, hippocampus, and hypothalamus) and measure a panel of 15 steroids using highly specific and sensitive liquid chromatography-tandem mass spectrometry. Maternal sucrose intake did not alter maternal food intake, body weight, and litter size, but increased the percentage of male offspring. We are currently analyzing the steroid data. We predict that maternal sucrose intake during pregnancy will increase anti-inflammatory steroids (corticosterone, DHC, and aldosterone) in the maternal blood, amniotic fluid and fetal brain, and decrease androgens in the placenta. We will also measure steroidogenic enzymes in the placenta and fetal brain. Our findings will clarify how maternal sucrose intake impacts both the placenta and fetal development. Moreover, our results will examine whether sucrose exposure during pregnancy is the underlying mechanism for the endocrine effects observed in the fetal and adult offspring. This study will provide more insight into the relationship between nutrition, the nervous system, and the endocrine system. Presentation: Friday, June 16, 2023

Effects of gestational haloperidol exposure on mRNA expressions related to glutamate and GABA receptors in offspring

Antipsychotic treatment is vital for patients with schizophrenia even in the perinatal period, but the impact at the molecular biological level on offspring is unclear. The aim of the present study was to investigate the effects of intraperitoneal haloperidol injection to pregnant mice on glutamate and GABA receptors in the brain of offspring mice. Eight-week-old pregnant mice were treated with either intraperitoneal haloperidol or normal saline injection, and their offspring were defined as F1 mice. In addition, eight-week-old male mice were used as acute mice that were intraperitoneally injected with haloperidol or normal saline for 20 days. mRNA expression levels were measured by RT-qPCR. Western blotting was performed of the frontal lobes of F1 mice. In the hippocampi of F1 mice, Grik3 (p = 0.023) and Gabra3 (p = 0.004) mRNA expression levels were significantly higher in the haloperidol group than in the control group, whereas Gria2 (p < 0.001) and Grin2a (p < 0.001) mRNA expression levels were significantly lower in the haloperidol group than in the control group. Gria2 (p = 0.015), and Grik3 (p = 0.037), and Grin2a (p = 0.012) mRNA expression levels were significantly lower in the haloperidol group than in the control group in the frontal lobes of F1 mice. In the hippocampi of acute mice, Grik3 (p = 0.049) and Gabra3 (p = 0.007) mRNA expression levels were significantly decreased in the haloperidol group. Fetal exposure to haloperidol can affect glutamate and GABA receptors through mRNA expression changes in the brain of offspring.

Interleukin-17A stimulation induces alterations in Microglial microRNA expression profiles.

Increased maternal interleukin (IL)-17A and activated microglia are pivotal factors contributing to the pathological phenotypes of maternal immune activation (MIA), developing neurodevelopmental disorders in offspring. This study aimed to determine whether IL-17A affects the microglial microRNA (miRNA) profiles. The miRNA expression profiles of primary cultured microglia stimulated with recombinant IL-17A were examined comprehensively using miRNA sequencing and validated through qRT-PCR. The expressions of miRNAs target genes identified using bioinformatics, were investigated in microglia transfected with mimic miRNA. The target gene's expression was also examined in the fetal brains of the MIA mouse model induced by maternal lipopolysaccharide (LPS) administration. Primary cultured microglia expressed the IL-17A receptor and increased proinflammatory cytokines and nitric oxide synthase 2 upon treatment with IL-17A. Among the three miRNAs with |log2FC | >1, only mmu-miR-206-3p expression was significantly up-regulated by IL-17A. Transfection with the mmu-miR-206-3p mimic resulted in a significant decrease in the expression of Hdac4 and Igf1, target genes of mmu-miR-206-3p. Hdac4 expression also significantly decreased in the LPS-induced MIA model. IL-17A affected microglial miRNA profiles with upregulated mmu-miR-206-3p. These findings suggest that targeting the IL-17A/mmu-miR-206-3p pathway may be a new strategy for predicting MIA-related neurodevelopmental deficits and providing preventive interventions. Despite the growing evidence of interleukin (IL)-17A and microglia in the pathology of maternal immune activation (MIA), the downstream of IL-17A in microglia is not fully known. IL-17A altered microRNA profiles and upregulated the mmu-miR-206-3p expression in microglia. The mmu-miR-206-3p reduced autism spectrum disorder (ASD) related gene expressions, Hdac4 and Igf1. The Hdac4 expression was also reduced in the brain of MIA offspring. The hsa-miR-206 sequence is consistent with that of mmu-miR-206-3p. This study may provide clues to pathological mechanisms leading to predictions and interventions for ASD children born to mothers with IL-17A-related disorders.

Associations between parental depression and anxiety symptom severity and their Offspring's cortical thickness and subcortical volume

Depression and anxiety are associated with grey matter changes in subcortical regions in adults and adolescents. Parent psychopathology is associated with offspring brain structure, but it's unclear whether altered brain structure in children is associated with severity of parental depression and anxiety symptoms. We examined 123 youth (Mean age = 13.64; 62% female) with no clinically significant history of depression or anxiety and one parent diagnosed with current or past depressive or anxiety disorders. Parents completed the Mini International Neuropsychiatric Interview to assess diagnostic status and the Beck Depression Inventory-II, and the Generalized Anxiety Disorder-7 to assess current symptom severity. Youth underwent T1 weighted structural Magnetic Resonance Imaging scans. Bivariate analyses revealed higher parental depressive severity was not significantly associated with offspring grey matter. Parental anxiety severity was significantly associated with less left global surface area. When controlling for offspring age, sex and intracranial volume (ICV), offspring right surface area was negatively associated with parental depressive severity at a trend level. In previously depressed parents, greater parental depressive severity was significantly associated with offspring decreased left and right surface area. There were no significant associations between parental anxiety severity in previously depressed parents and offspring subcortical or cortical brain regions. These results highlight associations between parental depressive symptom severity and offspring brain structure and suggest that even within an already high-risk group of adolescents, there may be altered cortical surface area depending on parent symptom severity. This may help identify youth most at risk for developing a mood disorder and could help further early intervention and identification efforts.

Maternal childhood maltreatment: associations to offspring brain volume and white matter connectivity.

The deleterious effects of adversity are likely intergenerational, such that one generation's adverse experiences can affect the next. Epidemiological studies link maternal adversity to offspring depression and anxiety, possibly via transmission mechanisms that influence offspring fronto-limbic connectivity. However, studies have not thoroughly disassociated postnatal exposure effects nor considered the role of offspring sex. We utilized infant neuroimaging to test the hypothesis that maternal childhood maltreatment (CM) would be associated with increased fronto-limbic connectivity in infancy and tested brain-behavior associations in childhood. Ninety-two dyads participated (32 mothers with CM, 60 without; 52 infant females, 40 infant males). Women reported on their experiences of CM and non-sedated sleeping infants underwent MRIs at 2.44 ± 2.74 weeks. Brain volumes were estimated via structural MRI and white matter structural connectivity (fiber counts) via diffusion MRI with probabilistic tractography. A subset of parents (n = 36) reported on children's behaviors at age 5.17 ± 1.73 years. Males in the maltreatment group demonstrated greater intra-hemispheric fronto-limbic connectivity (b = 0.96, p= 0.008, [95%CI 0.25, 1.66]), no differences emerged for females. Fronto-limbic connectivity was related to somatic complaints in childhood only for males (r = 0.673, p = 0.006). Our findings suggest that CM could have intergenerational associations to offspring brain development, yet mechanistic studies are needed.

Maternal Perinatal Stress Trajectories and Negative Affect and Amygdala Development in Offspring.

Maternal psychological stress during pregnancy is a common risk factor for psychiatric disorders in offspring, but little is known about how heterogeneity of stress trajectories during pregnancy affect brain systems and behavioral phenotypes in infancy. This study was designed to address this gap in knowledge. Maternal anxiety, stress, and depression were assessed at multiple time points during pregnancy in two independent low-risk mother-infant cohorts (N=115 and N=2,156). Trajectories in maternal stress levels in relation to infant negative affect were examined in both cohorts. Neonatal amygdala resting-state functional connectivity MRI was examined in a subset of one cohort (N=60) to explore the potential relationship between maternal stress trajectories and brain systems in infants relevant to negative affect. Four distinct trajectory clusters, characterized by changing patterns of stress over time, and two magnitude clusters, characterized by severity of stress, were identified in the original mother-infant cohort (N=115). The magnitude clusters were not associated with infant outcomes. The trajectory characterized by increasing stress in late pregnancy was associated with blunted development of infant negative affect. This relationship was replicated in the second, larger cohort (N=2,156). In addition, the trajectories that included increasing or peak maternal stress in late pregnancy were related to stronger neonatal amygdala functional connectivity to the anterior insula and the ventromedial prefrontal cortex in the exploratory analysis. The trajectory of maternal stress appears to be important for offspring brain and behavioral development. Understanding heterogeneity in trajectories of maternal stress and their influence on infant brain and behavioral development is critical to developing targeted interventions.

TRANSGENERATIONAL EFFECTS OF PRENATAL STRESS ON MEMORY AND EXPRESSION OF THE INSULIN-LIKE GROWTH FACTOR 2 GENE IN THE OFFSPRING BRAIN

Stress effects on pregnant female disrupt the behavior and cognitive abilities of their offspring not only of the first, but also of the subsequent generations. A similar transgenerational effect on the offspring phenotype can be exerted by various stress factors that affect fathers before conception. The purpose of the study was to reveal the transgenerational effect of stress in female rats from 15–19 days of pregnancy on memory and expression of the insulin-like growth factor 2 (Igf2) gene in the brain of male and female offspring, as well as the effect of additional stress in the stress-restress paradigm in prenatally stressed male rats before conception on the memory and expression in the brain Igf2 of their offspring of both sexes. We have shown that prenatally stressed males and their next-generation male offspring show improved memory in the passive avoidance test, increased Igf2 expression in the hippocampus and cortex. Females, descendants of prenatally stressed males, on the contrary, showed a decrease in the duration of memory retention, Igf2 expression in the hippocampus and cortex. Additional stressing of prenatally stressed males before mating with intact females worsened memory and the duration of its retention, reduced Igf2 expression in the brain of the offspring of both sexes. We concluded that the transgenerational effects of prenatal stress on memory and Igf2 expression in the brain depend on the sex of the offspring, and prenatal stress itself in males contributes to memory impairment and a decrease in Igf2 expression in the offspring brain if such males were additionally stressed before mating.

Transgenerational Effects of Prenatal Stress on Memory and Expression of the Insulin-Like Growth Factor 2 Gene in the Offspring Brain

Transgenerational Effects of Prenatal Stress on Memory and Expression of the Insulin-Like Growth Factor 2 Gene in the Offspring Brain

Effects of daily exposure to peat smoke on the reproductive and nervous systems in male white rats

Introduction. The regular occurrence of large-scale peat fires is an urgent medical and environmental problem of the modern scientific community. The peat smoke is a complex mixture of pollutants that have a serious impact on air quality and public health. &#x0D; Materials and methods. Adult male rats were exposed to peat smoke for 24 hours, the concentrations of PM2.5 and CO were 0.92±0.08 mg/m3 and 40.8±1.9 mg/m3, respectively. After exposure an open field examination, EEG examination and histological analysis of the testes and brain were performed, after which they were mated with intact females. Postnatal death of offspring in the first week of life, body weight, behaviour and electroencephalography indicators during puberty were evaluated.&#x0D; Results. There was showed an increase in motor activity, anxiety, and violation of EEG indicators in rat males exposed to peat smoke. Both an increase in shadow cells and degeneratively altered neurons in the nervous tissue were found. No changes were detected in the testes. Exposure to peat smoke during conception increased stillbirth and mortality of offspring during the first week of life, but did not affect weight gain. Violation of behaviour structure was recorded only in females offspring. An increase in slow-wave activity of the brain in males offspring was revealed.&#x0D; Limitations. The study was limited to studying the effects of a single 24-hour exposure to peat smoke on outbred white rats.&#x0D; Conclusion. A single peat smoke exposure for 24 hours at a concentration of PM2.5=0.92±0.08 mg/m3 and CO=40.8±1.9 mg/m3 leads to significant morphological and functional changes in the CNS. In the absence of a gonadotoxic effect, peat smoke exposure on males before mating causes specific changes in the behavior and bioelectrical activity of the brain of their offspring.

Prenatal Antidepressant Exposure and Offspring Brain Morphologic Trajectory

Clinical decision-making on antidepressant treatment during pregnancy, particularly selective serotonin reuptake inhibitors (SSRIs), is challenging, as both prenatal SSRI exposure and maternal depressive symptoms may be associated with negative outcomes in offspring. To investigate the association between intrauterine SSRI exposure and maternal depressive symptoms and structural brain development in offspring from mid-childhood to early puberty. This prospective, population-based cohort study was embedded in the Generation R Study in Rotterdam, the Netherlands. All pregnant individuals with an expected delivery date between April 1, 2002, and January 31, 2006, were invited to participate. Data were analyzed from February 1 to September 30, 2022. Maternal-reported SSRI use verified by pharmacy records. In mid-pregnancy and 2 and 6 months after delivery, participants reported depressive symptoms using the Brief Symptom Inventory and were divided into 5 groups: SSRI use during pregnancy (n = 41; 80 scans), SSRI use only before pregnancy (n = 77; 126 scans), prenatal depressive symptoms without prenatal SSRI use (n = 257; 477 scans), postnatal depressive symptoms only (n = 74; 128 scans), and nonexposed control individuals (n = 2749; 4813 scans). The main outcome was brain morphometry in offspring, including global and cortical brain volumes, measured at 3 magnetic resonance imaging assessments from 7 to 15 years of age. The study included 3198 mother-child dyads. A total of 3198 mothers (100%) identified as women; mean (SD) age at intake was 31.1 (4.7) years. Children (1670 [52.2%] female) underwent brain imaging assessment from 7 to 15 years of age with 5624 total scans. Most brain gray matter volumes showed an inverted U-shaped trajectory. Compared with nonexposed controls, children prenatally exposed to SSRIs had less cerebral gray matter (β [SE], -20 212.2 [7285.6] mm3; P = .006), particularly within the corticolimbic circuit, which persisted up to 15 years of age. Children exposed to SSRIs prenatally showed a steeper increase in volumes of the amygdala (age interaction: β [SE], 43.3 [13.4] mm3; P = .006) and fusiform gyrus (age interaction: β [SE], 168.3 [51.4] mm3; P = .003) from 7 to 15 years of age. These volumetric differences in the amygdala and fusiform observed in childhood did not persist until early adolescence. Prenatal depression was associated with a smaller volume in the rostral anterior cingulate gyrus (β [SE], -166.3 [65.1] mm3; P = .006), and postnatal depression was associated with a reduced fusiform gyrus (β [SE], -480.5 [189.2] mm3; P = .002). No association of SSRI use before pregnancy with brain outcomes was observed. The results of this cohort study suggest that prenatal SSRI exposure may be associated with altered developmental trajectories of brain regions involved in emotional regulation in offspring. Further research on the functional implications of these findings is needed.

Effects of Radiofrequency Electromagnetic Field (RF-EMF) exposure on pregnancy and birth outcomes: A systematic review of experimental studies on non-human mammals

Effects of Radiofrequency Electromagnetic Field (RF-EMF) exposure on pregnancy and birth outcomes: A systematic review of experimental studies on non-human mammals

Identification of immunodominant T cell epitopes induced by natural Zika virus infection.

Zika virus (ZIKV) is a flavivirus primarily transmitted by Aedes species mosquitoes, first discovered in Africa in 1947, that disseminated through Southeast Asia and the Pacific Islands in the 2000s. The first ZIKV infections in the Americas were identified in 2014, and infections exploded through populations in Brazil and other countries in 2015/16. ZIKV infection during pregnancy can cause severe brain and eye defects in offspring, and infection in adults has been associated with higher risks of Guillain-Barré syndrome. We initiated a study to describe the natural history of Zika (the disease) and the immune response to infection, for which some results have been reported. In this paper, we identify ZIKV-specific CD4+ and CD8+ T cell epitopes that induce responses during infection. Two screening approaches were utilized: an untargeted approach with overlapping peptide arrays spanning the entire viral genome, and a targeted approach utilizing peptides predicted to bind human MHC molecules. Immunoinformatic tools were used to identify conserved MHC class I supertype binders and promiscuous class II binding peptide clusters predicted to bind 9 common class II alleles. T cell responses were evaluated in overnight IFN-γ ELISPOT assays. We found that MHC supertype binding predictions outperformed the bulk overlapping peptide approach. Diverse CD4+ T cell responses were observed in most ZIKV-infected participants, while responses to CD8+ T cell epitopes were more limited. Most individuals developed a robust T cell response against epitopes restricted to a single MHC class I supertype and only a single or few CD8+ T cell epitopes overall, suggesting a strong immunodominance phenomenon. Noteworthy is that many epitopes were commonly immunodominant across persons expressing the same class I supertype. Nearly all of the identified epitopes are unique to ZIKV and are not present in Dengue viruses. Collectively, we identified 31 immunogenic peptides restricted by the 6 major class I supertypes and 27 promiscuous class II epitopes. These sequences are highly relevant for design of T cell-targeted ZIKV vaccines and monitoring T cell responses to Zika virus infection and vaccination.

Transcriptional diversity of the oxytocin receptor in prairie voles: mechanistic implications for behavioral neuroscience and maternal physiology.

The neurohormone oxytocin regulates many aspects of physiology primarily by binding to its receptor, the oxytocin receptor. The oxytocin receptor gene (Oxtr) has been shown to have alternative transcripts in the mouse brain which may each have different biological functions or be used in specific contexts. A popular animal model for studying oxytocin-dependent social behaviors is the prairie vole, a biparental and monogamous rodent. Alternative transcriptional capacity of Oxtr in prairie voles is unknown. We used 5' rapid amplification of cDNA ends to identify alternative Oxtr transcription start sites in prairie vole brain tissue and uterine tissue. We then validated expression of specific transcripts in fetal brains and assessed the impact of exogenous oxytocin administration in utero on offspring brain development. We identified seven distinct Oxtr transcripts, all of which are present in both brain and uterine tissue. We then demonstrated that maternal oxytocin administration alters expression of a specific subset of Oxtr transcripts and that these different transcripts are under unique epigenetic regulation, such that in the perinatal period only one of the alternative transcripts is associated with DNA methylation in the Oxtr promoter. These data establish the existence of multiple Oxtr transcripts in prairie vole brain and uterine tissue and implicate oxytocin in the regulation of alternative transcript expression. These data have significant implications for our understanding of null mutant models in both mice and voles and translation in human birth and behavior.

Marginal Zinc Deficiency during Gestation and Lactation in Rats Affects Oligodendrogenesis, Motor Performance, and Behavior in the Offspring

BackgroundOligodendrocytes are responsible for myelin production in the central nervous system (CNS). Hypomyelination may slow saltatory nerve signal conduction and affect motor performance and behavior in adults. Gestational marginal zinc deficiency in rats significantly decreases proliferation of neural stem cells (NSCs) in the offspring brain. ObjectivesGiven that NSCs are precursors of oligodendrocytes, this study investigated if marginal zinc deficiency during early development in rats affects oligodendrogenesis in the offspring’s CNS. MethodsRat dams were fed an adequate (25 μg zinc/g diet) (C) or a marginal zinc diet (MZD) (10 μg zinc/g diet), from gestation day zero until postnatal day (P) 20, and subsequently all offspring was fed the control diet until P60. Oligodendrogenesis was evaluated in the offspring at P2, P5, P10, P20, and P60, by measuring parameters of oligodendrocyte progenitor cells (OPCs) proliferation, differentiation, maturation, and of myelination. ResultsThe expression of 1) proteins that regulate OPC proliferation (Shh, Sox10, Olig2); 2) OPC markers (NG2, PDGFRα); 3) myelin proteins (MBP, MAG, MOG, PLP) were lower in the brain cortex from MZD than C offspring at various stages in development. The amount of myelin after zinc replenishment continued to be low in the MZD young adult at P60. Accordingly, parameters of motor performance and behavior [grip strength, rotarod, elevated T-maze (ETM), and open-field tests] were impaired in the MZD offspring at P60. ConclusionsResults support the concept that maternal and early postnatal exposure to MZD affects oligodendrogenesis causing long-lasting effects on myelination and on motor performance in the young adult offspring.

Prenatal Exposure to Maternal Mood Entropy Is Associated With a Weakened and Inflexible Salience Network in Adolescence

BackgroundFetal exposure to maternal mood dysregulation influences child cognitive and emotional development, which may have long-lasting implications for mental health. However, the neurobiological alterations associated with this dimension of adversity have yet to be explored. Here, we tested the hypothesis that fetal exposure to entropy, a novel index of dysregulated maternal mood, would predict the integrity of the salience network, which is involved in emotional processing. MethodsA sample of 138 child-mother pairs (70 females) participated in this prospective longitudinal study. Maternal negative mood level and entropy (an index of variable and unpredictable mood) were assessed 5 times during pregnancy. Adolescents engaged in a functional magnetic resonance imaging task that was acquired between 2 resting-state scans. Changes in network integrity were analyzed using mixed-effect and latent growth curve models. The amplitude of low frequency fluctuations was analyzed to corroborate findings. ResultsPrenatal maternal mood entropy, but not mood level, was associated with salience network integrity. Both prenatal negative mood level and entropy were associated with the amplitude of low frequency fluctuations of the salience network. Latent class analysis yielded 2 profiles based on changes in network integrity across all functional magnetic resonance imaging sequences. The profile that exhibited little variation in network connectivity (i.e., inflexibility) consisted of adolescents who were exposed to higher negative maternal mood levels and more entropy. ConclusionsThese findings suggest that fetal exposure to maternal mood dysregulation is associated with a weakened and inflexible salience network. More broadly, they identify maternal mood entropy as a novel marker of early adversity that exhibits long-lasting associations with offspring brain development.

Maternal Thyroid Function During Pregnancy and Offspring White Matter Microstructure in Early Adulthood: A Prospective Birth Cohort Study.

Background: The fetus is fully dependent on maternal thyroid hormones until mid-gestation and suboptimal maternal thyroid function has been associated with alterations in the neurodevelopment of the offspring. We used maternal free thyroxine (fT4) and thyrotropin (TSH) levels in early gestation to study the association of maternal thyroid function during early pregnancy and offspring brain white matter (WM) integrity in early adulthood. Methods: Our study population consisted of a total of 292 mother-child pairs. Maternal fT4 and TSH were used as predictors and offspring multimodal imaging measures of fractional anisotropy, mean diffusivity, and magnetization transfer ratio (FA, MD, and MTR) as dependent variables. First, as Global analysis, all analyzed 14 WM tracts were studied simultaneously using linear-mixed effect models. Second, if a global effect was detected, a post hoc Tract-wise analysis was carried out using linear models individually in each WM tract. Study population was stratified by sex. Results: We found a positive association between maternal fT4 and offspring Global FA in males when adjusted for all maternal and offspring covariates (n = 114; β = 0.154; confidence interval = 0.045-0.263; p = 0.006). The finding was observed to be driven by multiple WM tracts, of which three projection fiber tracts and the forceps minor survived correcting for multiple comparisons in Tract-wise analysis. Conclusions: Maternal thyroid function in early pregnancy was observed to be associated with WM microstructure in male offspring in early adulthood. Our results suggest that maternal fT4 levels in early pregnancy may modulate axonal characteristics, with a long-term effect on offspring WM development.