A proteomics-metabolomics approach indicates changes in hypothalamic glutamate-GABA metabolism of adult female rats submitted to intrauterine growth restriction

Association and shared biological bases between birth weight and cortical structure

Associations between birth weight and cortical structural phenotypes have been detected; however, the understanding is incomprehensive, and the potential biological bases are not well defined. Leveraging data from genome-wide association studies, we investigated the associations and the shared transcriptomic, proteomic and cellular bases of birth weight and 13 cortical structural phenotypes. Mendelian randomization analyses were performed to examine associations between birth weight and cortical structure. Downstream transcriptome-wide association study (TWAS), proteome-wide association study (PWAS) and summary-based Mendelian randomization (SMR) analyses were utilized to identify the shared cis-regulated gene expressions and proteins. Finally, cell-type expression-specific integration for complex traits (CELLECT) analyses were conducted to explore the enriched cell types. The Mendelian randomization analyses found positive associations between birth weight and global cortical folding index, intrinsic curvature index, local gyrification index, surface area and volume. Downstream transcriptomic-level TWAS and SMR identified three gene expressions both linked to birth weight and at least one cortical structural phenotype (CNNM2, RABGAP1 and CENPW). Parallel PWAS and SMR analyses at the proteomic level identified four proteins linked to both phenotypes (CNNM2, RAB7L1, RAB5B and PPA2), of which CNNM2 was replicated. CELLECT analyses revealed brain cell types enriched in birth weight, including pericytes, inhibitory GABAergic neurons and cerebrovascular cells. These findings support the importance of early life growth to cortical structure, and suggest underlying transcriptomic, proteomic and cellular bases. These results provide intriguing targets for further research into the mechanisms of cortical development.

A scoping review regarding reproductive capacity modulation based on alpha-ketoglutarate supplementation

In brief

Alpha-ketoglutarate is a common metabolite in the tricarboxylic acid cycle and is central in modulating the reproductive potential in animal models. The present scoping review systematically covers the spectrum of a wide range of evidence from different viewpoints, focusing on the underlying processes and mechanisms of the developmental framework, aiming to fill the gaps within the existing literature.

Abstract

Alpha-ketoglutarate is an important intermediate molecule in the tricarboxylic acid cycle with a prominent role in distinct biological processes such as cellular energy metabolism, epigenetic regulation, and signaling pathways. We conducted a registered scoping review (OSF: osf.io/b8nyt) to explore the impact of exogenous supplementation on reproductive capabilities. Our strategy included evaluating the main research literature from different databases like PubMed-MEDLINE, Web of ScienceTM, Scopus, and Excerpta Medica dataBASE using a specific systematic layout to encompass all investigations based on experimental models and critically compare the results. Twenty-one studies were included in the main body of this manuscript, which revealed that exogenous supplementation induced dose- and sex-dependent modifications. This metabolite modulates the expression of pluripotency genes, thus controlling stem cells' self-renewal, differentiation, and reprogramming dynamics, while also alleviating structural transformations induced by exposure to heavy metals and other inhibitors. This significantly demonstrated a direct influence of alpha-ketoglutarate in mitigating oxidative stress and prolonging the lifespan, consequently supporting metabolic and endocrine adjustments. It influences oocyte quality and quantity, delays reproductive aging, and establishes an optimal competence framework for development with minimal risk of failure. Therefore, alpha-ketoglutarate is linked to improving reproductive performance, but further studies are needed due to a lack of studies on humans.

Coupling of GABA Metabolism to Mitochondrial Glucose Phosphorylation

Glucose and oxygen (O₂) are vital to the brain. Glucose metabolism and mitochondria play a pivotal role in this process, culminating in the increase of reactive O₂ species. Hexokinase (HK) is a key enzyme on glucose metabolism and is coupled to the brain mitochondrial redox modulation by recycling ADP for oxidative phosphorylation (OXPHOS). GABA shunt is an alternative pathway to GABA metabolism that increases succinate levels, a Krebs cycle intermediate. Although glucose and GABA metabolisms are intrinsically connected, their interplay coordinating mitochondrial function is poorly understood. Here, we hypothesize that the HK and the GABA shunt interact to control mitochondrial metabolism differently in the cortex and the hypothalamus. The GABA shunt stimulated mitochondrial O₂ consumption and H₂O₂ production higher in hypothalamic synaptosomes (HSy) than cortical synaptosomes (CSy). The GABA shunt increased the HK coupled to OXPHOS activity in both population of synaptosomes, but the rate of activation was higher in HSy than CSy. Significantly, malonate and vigabatrin blocked the effects of the GABA shunt in the HK activity coupled to OXPHOS. It indicates that the glucose phosphorylation is linked to GABA and Krebs cycle reactions. Together, these data shed light on the HK and SDH role on the metabolism of each region fed by GABA turnover, which depends on the neurons' metabolic route.

Mechanisms Underlying Neurologic Injury in Intrauterine Growth Restriction

Intrauterine growth restriction is a condition that prevents normal fetal development, and previous studies have reported that intrauterine growth restriction is caused by adverse intrauterine factors. This condition affects both short- and long-term neurodevelopmental disorders. Studies have revealed that neurodevelopmental disorders can contribute to gray and white matter damage and decrease the brain volume of affected individuals. Further, these disorders are associated with increased risks of mental retardation, cognitive impairment, and cerebral palsy, which seriously affect the quality of life. Although the mechanisms underlying the neurologic injury associated with intrauterine growth restriction are not completely clear, studies have revealed that neuronal apoptosis, neuroinflammation, oxidative stress, excitatory toxicity, disruption of blood-brain barrier, and epigenetics may be involved in this process. This article reviews the manifestations and possible mechanisms underlying neurologic injury in intrauterine growth restriction and provides a theoretical basis for the effective prevention and treatment of this condition.

Intrauterine growth restriction weakens anticontractile influence of NO in coronary arteries of adult rats

Intrauterine growth restriction (IUGR) is one of the most common pathologies of pregnancy. The cardiovascular consequences of IUGR do not disappear in adulthood and can manifest themselves in pathological alterations of vasomotor control. The hypothesis was tested that IUGR weakens anticontractile influence of NO and augments procontractile influence of Rho-kinase in arteries of adult offspring. To model IUGR in the rat, dams were 50% food restricted starting from the gestational day 11 till delivery. Mesenteric and coronary arteries of male offspring were studied at the age of 3 months using wire myography, qPCR, and Western blotting. Contractile responses of mesenteric arteries to α1-adrenoceptor agonist methoxamine as well as influences of NO and Rho-kinase did not differ between control and IUGR rats. However, coronary arteries of IUGR rats demonstrated elevated contraction to thromboxane A2 receptor agonist U46619 due to weakened anticontractile influence of NO and enhanced role of Rho-kinase in the endothelium. This was accompanied by reduced abundance of SODI protein and elevated content of RhoA protein in coronary arteries of IUGR rats. IUGR considerably changes the regulation of coronary vascular tone in adulthood and, therefore, can serve as a risk factor for the development of cardiac disorders.

Early glutathione intervention educed positive correlation between VGLUT1 expression and spatial memory in the Nω-nitro-L-arginine methyl rat model of IUGR

INTRODUCTION

One of the most compelling causes of perinatal mortality and morbidity is intrauterine growth restriction (IUGR). IUGR is linked with numerous health challenges that last lifelong, including neurodevelopmental impairment and a high incidence of brain dysfunction. There is mounting evidence that places the glutamatergic system at the center of the neurobiology and treatment of neurological diseases. Therefore, this study investigated the effects of postnatal glutathione intervention on the spatial memory and the expressions of vesicular glutamate transporter 1 (VGLUT1) in the hippocampus and the cerebellar cortex of Nω-nitro-L-arginine methyl (L-NAME)-induced rat model of IUGR.

MATERIALS AND METHOD

Twelve adult female rats were divided into Control and L-NAME groups; each containing 6 female rats. The control group received a single daily dose of normal saline while the L-NAME group was administered 50 mg/kg L-NAME daily from gestational day 9 until parturition. Offspring of the control rats were given free access to feeds while offspring from the L-NAME group were assigned into 3 groups: G1: given free access to feeds; G2 and G3 were administered 1.5 mg/kg body weight of glutathione from postnatal day (PND) 4-9 and PND 25-31 respectively. At the end of the intervention, Y-maze was conducted, and the rats euthanized on PND 35. The brain sections were processed, and immunofluorescence staining was performed using the Vectafluor Excel R.T.U Antibody kit.

RESULTS

IUGR caused a significant 31.1% decrease in spontaneous alternation percentage (SAP), while early treatment with glutathione at PND 4-9 significantly (p < 0.01) increased SAP, while late treatment at PND 25-9 significantly decreased SAP compared to IUGR group. Furthermore, IUGR caused significant (p < 0.001) downregulation in corrected total cell fluorescence (CTCF) of VGLUT1 in both the hippocampus and cerebellar cortex. While treatment with glutathione caused upregulation in CTCF of VGLUT1 in the hippocampus and the cerebellar cortex.

CONCLUSION

Our results showed that early intervention with glutathione has significant therapeutic potential via upregulation of VGLUT1 expression in both hippocampus and cerebellar cortex, which positively correlated with enhanced spatial memory in IUGR rat model.

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.

Snake venom color and L-amino acid oxidase: An evidence of long-term captive Crotalus durissus terrificus venom plasticity

The venom color variation of Crotalus durissus terrificus (Cdt) is attributed to the presence of the toxin L-amino acid oxidase (LAAO). During the venom milking routine of Instituto Butantan, we have noticed that most venoms of captive Cdt specimens show a yellowish color, while most venoms of wild specimens are white. Here we describe a comparative analysis of long-term captive (LTC) and recently wild-caught (RWC) Cdt, focusing on LAAO variation. For the identification of LAAO in individual venoms, four different approaches were employed: evaluation of the enzymatic activity, SDS-PAGE, Western blotting, and ELISA. In addition, mass spectrometry analysis was performed using pooled samples. Although some variation among these methodologies was observed, it was possible to notice that the presence of LAAO was significantly higher in the venom of LTC individuals. LAAO was identified in 60-80% LTC specimens and in only 10-12% of RWC specimens. Furthermore, this enzyme accounts for 5.6% of total venom proteins of LTC Cdt pooled venom, while it corresponds to only 0.7% of RWC Cdt pooled venom. These findings strongly suggest that captive maintenance increases the expression of LAAO in Cdt venom.

High-fat but not normal-fat intake of extra virgin olive oil modulates the liver proteome of mice

PURPOSE

The metabolic benefits of the Mediterranean diet have been largely attributed to its olive oil content. Whether the ingested fat amount is relevant to these effects is not clear. We thus compared the effects of high-fat and normal-fat intake of extra-virgin olive oil (EVOO) on the liver proteome.

METHODS

Three groups of mice were fed for 12 weeks with either normal-fat diets containing either soybean oil (control, C) or EVOO (NO) or a high-fat EVOO diet (HO). Body weight and food intake were measured weekly and serum parameters were analyzed. The liver was processed for data-independent acquisition mass spectrometry-based proteomics. The differentially expressed proteins among the groups were submitted to pathway enrichment analysis.

RESULTS

The consumption of HO diet reduced food intake and serum triglycerides, while it preserved body weight gain, adiposity, and glycemia. However, it increased serum cholesterol and liver mass. The proteomic analysis showed 98 altered proteins, which were allocated in 27 significantly enriched pathways. The pathway analysis suggested stimulation of mitochondrial and peroxissomal β-oxidation, and inhibition of lipid synthesis and gluconeogenesis in the HO group. Although the NO group failed to show significant liver proteome alterations, it presented reduced body fat, body weight gain, and serum triglycerides and glucose levels.

CONCLUSION

The data indicate that the intake of the HO diet induced hepatic adjustments, which were partially successful in counteracting the detrimental outcomes of a high-fat feeding. Contrastingly, the NO diet had beneficial effects which were not accompanied by significant modifications on hepatic proteome.

Differential Effects of Post-Weaning Diet and Maternal Obesity on Mouse Liver and Brain Metabolomes

Nutritional changes during developmental windows are of particular concern in offspring metabolic disease. Questions are emerging concerning the role of maternal weight changes before conception, particularly for weight loss, in the development of diet-related disorders. Understanding the physiological pathways affected by the maternal trajectories in the offspring is therefore essential, but a broad overview is still lacking. We recently reported both metabolic and behavioral negative outcomes in offspring born to obese or weight-loss mothers and fed a control of high-fat diet, suggesting long-term modeling of metabolic pathways needing to be further characterized. Using non-targeted LC–HRMS, we investigated the impact of maternal and post-weaning metabolic status on the adult male offspring’s metabolome in three tissues involved in energy homeostasis: liver, hypothalamus and olfactory bulb. We showed that post-weaning diet interfered with the abundance of several metabolites, including 1,5-anhydroglucitol, saccharopine and β-hydroxybutyrate, differential in the three tissues. Moreover, maternal diet had a unique impact on the abundance of two metabolites in the liver. Particularly, anserine abundance, lowered by maternal obesity, was normalized by a preconceptional weight loss, whatever the post-weaning diet. This study is the first to identify a programming long-term effect of maternal preconception obesity on the offspring metabolome.