Differential expression of genes in fetal brain as a consequence of maternal protein deficiency and nematode infection

Maternal gastrointestinal nematode infection enhances spatial memory of uninfected juvenile mouse pups

The developing brain is particularly vulnerable to factors including maternal infection during pregnancy. Establishment of neural networks critical for memory and cognition begins during the perinatal period, when Heligmosomoides bakeri, a gastrointestinal (GI) nematode restricted to the maternal mouse intestine, has been shown to upregulate expression of long-term potentiation genes in the young rodent pup brain. We explored the impact of maternal infection during pregnancy and early lactation on the spatial behavior of uninfected male and female juvenile mice. Pre-weaned pups of H. bakeri infected dams exhibited less exploratory behaviour compared to pups of uninfected dams on postnatal day (PD) 16 but not PD 17, possibly reflecting a transient fear of an unfamiliar environment and/or a brief neurodevelopmental delay. Our two spatial memory tests show for the first time an enhancement of spatial memory in response to maternal nematode infection regardless of pup sex. At PD 17, pups of infected dams expressed object location memories after 3 h in the Object Location Test whereas offspring of uninfected mothers did not. In addition, at PD 34, juveniles of infected mothers retained their ability to find the escape hole in the Barnes Maze Test for one week whereas offspring from uninfected mothers did not. This finding is even more striking given that spatial memory was positively associated with pup length, yet this maternal infection impaired linear growth of pups. Thus, the positive impact of maternal infection on spatial memory countered any impairment associated with the shorter length of the pups. Overall, these novel findings indicate that a maternal GI nematode infection during pregnancy and lactation positively influences the spatial memory of uninfected juvenile offspring with potential fitness implications for the next generation.

Maternal nematode infection upregulates expression of Th2/Treg and diapedesis related genes in the neonatal brain

Intestinal nematode infections common during pregnancy have recently been shown to have impacts that extend to their uninfected offspring including altered brain gene expression. If maternal immune signals reach the neonatal brain, they might alter neuroimmune development. We explored expression of genes associated with four distinct types of T cells (Th1, Th2, Th17, Treg) and with leukocyte transendothelial migration and endocytosis transport across the blood–brain barrier (BBB) in the postnatal brain of offspring of nematode-infected mice, through secondary analysis of a whole brain gene expression database. Th1/Th17 expression was lowered by maternal infection as evidenced by down-regulated expression of IL1β, Th1 receptors and related proteins, and of IL22 and several Th17 genes associated with immunopathology. In contrast, Th2/Treg related pathways were upregulated as shown by higher expression of IL4 and TGF-β family genes. Maternal infection also upregulated expression of pathways and integrin genes involved in transport of leukocytes in between endothelial cells but downregulated endosome vesicle formation related genes that are necessary for endocytosis of immunoglobulins across the BBB. Taken together, pup brain gene expression indicates that maternal nematode infection enhanced movement of leukocytes across the neonatal BBB and promoted a Th2/Treg environment that presumably minimizes the proinflammatory Th1 response in the pup brain.

The Effect of Prenatal Food Restriction on Brain Proteome in Appropriately Grown and Growth Restricted Male Wistar Rats

Background

Fetal growth restriction (FGR) has been associated with a higher risk of developing adverse perinatal outcomes and distinct neurodevelopmental and neurobehavioral disorders. The aim of the present study was to investigate the impact of prenatal food restriction on the brain proteome in both FGR and appropriately grown rats and to identify potential pathways connecting maternal malnutrition with altered brain development.

Methods

Ten time-dated pregnant Wistar rats were housed individually at their 12th day of gestation. On the 15th day of gestation, the rats were randomly divided into two groups, namely the food restricted one (n = 6) and the control group (n = 4). From days 15 to 21 the control group had unlimited access to food and the food restricted group was given half the amount of food that was on average consumed by the control group, based on measurements taken place the day before. On the 21st day of gestation, all rats delivered spontaneously and after birth all newborn pups of the food restricted group were weighed and matched as appropriately grown (non-FGR) or growth restricted (FGR) and brain tissues were immediately collected. A multiplex experiment was performed analyzing brain tissues from 4 FGR, 4 non-FGR, and 3 control male offspring. Differentially expressed proteins (DEPs) were subjected to bioinformatics analysis in order to identify over-represented processes.

Results

Proteomic analysis resulted in the profiling of 3,964 proteins. Gene ontology analysis of the common DEPs using DAVID (https://david.ncifcrf.gov/) showed significant enrichment for terms related to cellular morphology, learning, memory and positive regulation of NF-kappaB signaling. Ingenuity Pathway Analysis showed significant induction of inflammation in FGR pups, whereas significant induction of cell migration and cell spreading were observed in non-FGR pups.

Conclusion

This study demonstrated that in both FGR and non-FGR neonates, a range of adaptive neurodevelopmental processes takes place, which may result in altered cellular morphology, chronic stress, poor memory and learning outcomes. Furthermore, this study highlighted that not only FGR, but also appropriately grown pups, which have been exposed to prenatal food deprivation may be at increased risk for impaired cognitive and developmental outcomes.

Inhibitor of growth 4 affects hypoxia-induced migration and angiogenesis regulation in retinal pigment epithelial cells

Inhibitor of growth 4 (ING4), a potential tumor suppressor, is implicated in cell migration and angiogenesis. However, its effects on diabetic retinopathy (DR) have not been elucidated. In this study, we aimed to evaluate ING4 expression in normal and diabetic rats and clarify its effects on hypoxia-induced dysfunction in human retinal pigment epithelial (ARPE-19) cells. A Type 1 diabetic model was generated by injecting rats intraperitoneally with streptozotocin and then killed them 4, 8, or 12 weeks later. ING4 expression in retinal tissue was detected using western blot analysis, reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR), and immunohistochemistry assays. After transfection with an ING4 overexpression lentiviral vector or small interfering RNA (siRNA), ARPE-19 migration under hypoxia was tested using wound healing and transwell assays. The angiogenic effect of conditioned medium (CM) from ARPE-19 cells was examined by assessing human retinal endothelial cell (HREC) capillary tube formation. Additionally, western blot analysis and RT-qPCR were performed to investigate the signaling pathways in which ING4, specificity protein 1 (Sp1), matrix metalloproteinase 2 (MMP-2), MMP-9, and vascular endothelial growth factor A (VEGF-A) were involved. Here, we found that ING4 expression was significantly reduced in the diabetic rats' retinal tissue. Silencing ING4 aggravated hypoxia-induced ARPE-19 cell migration. CM collected from ING4 siRNA-transfected ARPE-19 cells under hypoxia promoted HREC angiogenesis. These effects were reversed by ING4 overexpression. Furthermore, ING4 suppressed MMP-2, MMP-9, and VEGF-A expression in an Sp1-dependent manner in hypoxia-conditioned ARPE-19 cells. Overall, our results provide valuable mechanistic insights into the protective effects of ING4 on hypoxia-induced migration and angiogenesis regulation in ARPE-19 cells. Restoring ING4 may be a novel strategy for treating DR.

Maternal Gastrointestinal Nematode Infection Up-regulates Expression of Genes Associated with Long-Term Potentiation in Perinatal Brains of Uninfected Developing Pups

Establishment of neural networks critical for memory and cognition begins during the perinatal period but studies on the impact of maternal infection are limited. Using a nematode parasite that remains in the maternal intestine, we tested our hypothesis that maternal infection during pregnancy and early lactation would alter perinatal brain gene expression, and that the anti-inflammatory nature of this parasite would promote synaptic plasticity and long-term potentiation. Brain gene expression was largely unaffected two days after birth, but in seven-day old pups, long-term potentiation and four related pathways essential for the development of synaptic plasticity, cognition and memory were up-regulated in pups of infected dams. Interestingly, our data suggest that a lowering of Th1 inflammatory processes may underscore the apparent beneficial impact of maternal intestinal infection on long-term potentiation.

The essential role of tumor suppressor gene ING4 in various human cancers and non-neoplastic disorders

Inhibitor of growth 4 (ING4), a member of the ING family discovered in 2003, has been shown to act as a tumor suppressor and is frequently down-regulated in various human cancers. Numerous published in vivo and in vitro studies have shown that ING4 is responsible for important cancer hallmarks such as pathologic cell cycle arrest, apoptosis, autophagy, contact inhibition, and hypoxic adaptation, and also affects tumor angiogenesis, invasion, and metastasis. These characteristics are typically associated with regulation through chromatin acetylation by binding histone H3 trimethylated at lysine 4 (H3K4me3) and through transcriptional activity of transcription factor P53 and NF-κB. In addition, emerging evidence has indicated that abnormalities in ING4 expression and function play key roles in non-neoplastic disorders. Here, we provide an overview of ING4-modulated chromosome remodeling and transcriptional function, as well as the functional consequences of different genetic variants. We also present the current understanding concerning the role of ING4 in the development of neoplastic and non-neoplastic diseases. These studies offer inspiration for pursuing novel therapeutics for various cancers.

Infant growth faltering linked to subclinical mastitis, maternal faecal-oral contamination, and breastfeeding

Infant growth faltering occurs in breastfed infants <6 months of age. The possibility that maternal health status contributes to this growth faltering is underexplored. We investigated whether (a) subclinical mastitis (SCM), an asymptomatic inflammation of the breast, (b) maternal intestinal nematode and protozoan infections, indicators of faecal-oral contamination, or (c) poor breastfeeding practices increased the odds of stunting (length-for-age z-score < -2SD), underweight (weight-for-age z-score < -2SD), or low head circumference (head circumference-for-age z-score < -2SD) in breastfed infants in rural indigenous communities in Guatemala. Mother-infant dyads (n = 105) were subdivided into those with and without SCM (milk Na:K ratio > 0.6). Maternal and infant anthropometry were measured at the time of breast milk collection. Maternal stool samples were examined for the presence of intestinal nematodes and protozoa. Questionnaires were used to characterize breastfeeding practices (exclusivity and frequency) and support, hygiene (latrine use and household faucet), and infant diarrhoea. SCM occurred in 14% of women and was associated with increased odds of infant stunting (odds ratio [OR] = 4.3; confidence interval [CI] [1.1, 15.8]), underweight (OR = 9.2; CI [1.8, 48.0]), and low head circumference (OR = 15.9; CI [2.6, 96.9]). Maternal pathogenic protozoa and nematodes were uncommon (<4%), but nonpathogenic protozoa were common (e.g., Entamoeba coli [39%]). Entamoeba coli increased the likelihood (OR = 3.3; CI [1.02, 10.6]) of low head circumference, whereas higher breastfeeding frequency lowered its odds (OR = 0.74, CI [0.56, 0.97]). Prevention of SCM may improve early infant growth, but public health measures that increase breastfeeding frequency and reduce faecal-oral contamination may be required to minimize low head circumference.