Neonatal Exposure Research Articles

Pretreatment with tetramethylpyrazine alleviated the impairment of learning and memory induced by sevoflurane exposure in neonatal rats

Sevoflurane impairs learning and memory of the developing brain. However, strategies to mitigate these detrimental effects have been scarce. Herein, we investigated whether tetramethylpyrazine could alleviate the impairment of learning and memory and its underlying mechanisim in sevoflurane-exposed neonatal rats. Postnatal 7-day Sprague-Dawley (SD) rats or primary hippocampal neurons were pretreated with tetramethylpyrazine and then exposed to sevoflurane. The terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and lactate dehydrogenase (LDH) assays were used to detect neuronal injury. Learning and memory function were evaluated by novel object recognition and Morris water maze tests. Long-term potentiation (LTP) was recorded to evaluate synaptic plasticity electrophysiologically in the hippocampal slices. Golgi-Cox staining or PSD95 immunochemistry was used to detect the morphology of dendritic spines. Western blotting was employed to assess the expressions of cleaved Caspase-3, PSD95, NMDAR1, NMDAR2A and NMDAR2B in the hippocampus or cultured neurons. It was found that neonatal exposure of sevoflurane impaired learning and memory, increased neuronal apoptosis, altered the morphology of dendritic spine, upregulated the expressions of NMDAR2A and PSD95, and induced LTP deficits. Pretreatment with tetramethylpyrazine not only alleviated impairment of learning and memory, but also improved sevoflurane-induced changes in neuronal damage, dendritic spine morphology, NMDAR2A and PSD95 expressions, as well as LTP. These findings indicated that pretreatment with tetramethylpyrazine alleviated the impairment of learning and memory induced by sevoflurane through improvement of hippocampal synaptic plasticity in neonatal rats.

Impact of neonatal hyperoxia on the development of the coronary vascular bed: an experimental model for the study of cardiomyopathy associated with premature birth

Abstract Introduction Very preterm birth (PT; <32 weeks of gestation), nearly 2% of all births, leads to short-term complications such as bronchopulmonary dysplasia and retinopathy of prematurity that are driven by compromised organ vascular development. Adults born preterm display an increased risk of ischaemic cardiomyopathy and heart failure. Our group has shown that neonatal rats exposed to hyperoxia, simulating the PT neonatal conditions, develop cardiomyocytes hypertrophy, fibrosis and cardiac dysfunction, or Oxygen-Induced Cardiomyopathy (OIC). Whether cardiac changes also associate with alterations in vascular development in the left ventricle (LV) remains unknown. Purpose We hypothesized that neonatal exposure to hyperoxia impact the development of the LV vascular network. Methods Male pups were exposed to 80% O2 (OIC) or room air (CTRL) from day 3 (P3) to P10 of life. Hearts were collected at P10, 4- and 16 weeks. Arteriolar length and capillary density per cardiomyocyte were measured using stereology (elastin) and immunofluorescence (WGA, α-SMA, CD31). High-resolution 3D reconstruction of the vascular network was achieved by combining fluorescent labelling of coronaries (anti-α-SMA) and capillaries (anti-CD31) with a tissue-cleaning protocol (iDisco+), allowing detailed morphometric characterization of the vascular network. The expression of vascular endothelial growth factors and receptors (VEGFA, VEGFB, VEGFR 1 and 2, NRP1, and PIGF) were quantified by RT-qPCR and Western blots. Differences between groups were analyzed with Student's t-test (P < 0.05) (N = 6 per group). Results At P10, we observed a notable rise in the number of capillaries per cardiomyocyte (0.88 ± 0.05 vs. 0.62 ± 0.02 mm2) and a significant increase in VEGFA (+76%) and NRP1 (+38%) expression in the LV from OIC vs. CTRL rats. By 4 weeks, the OIC group showed a significant reduction in arteriolar length vs. CTRL (6.51 ± 0.76 vs. 9.77 ± 1.12 m/cm3), coupled with an increase in the number of capillaries per cardiomyocyte (1.11 ± 0.05 vs. 0.85 ± 0.03 mm2). VEGFA was decreased (-14%) and PLGF increased (+24%) in the LV of OIC rats. At 16 weeks, the OIC condition displayed a significant increase in the number of capillaries per cardiomyocyte (1.37 ± 0.03 vs. 0.98 ± 0.07 mm2) and a decrease in VEGFA (-23%), along with reduction in its receptors VEGFR1 (-27%), VEGFR2 (-20%) and NRP1 (-17%). Conclusion OIC resulting from neonatal hyperoxia exposure associates with vascular changes in the LV that persist to adulthood. These changes are characterized by a reduction in arteriolar length and an increase in the number of capillaries, accompanied by modulation of the expression of pro-angiogenic VEGFA and receptors. The impact of these vascular alterations on the susceptibility of the LV to ischemic or hypertension-related damage is to be explored. These findings suggest a crucial mechanistic pathway for understanding the risk of cardiac pathologies associated with preterm birth.

Sertraline-Induced 5-HT Dysregulation in Mouse Cardiomyocytes and the Impact on Calcium Handling.

Selective serotonin reuptake inhibitors (SSRIs) are prescribed in 15% of pregnancies in the United States for depression. Maternal use of SSRIs has been linked to an increased risk of congenital heart defects, but the exact mechanism of pathogenesis is unknown. SSRIs, including sertraline, are permeable to the placenta and can produce direct fetal exposure. Previously, we have shown decreased cardiomyocyte proliferation, left ventricle size, and cardiac expression of the serotonin receptor 5-HT2B in offspring of mice exposed to the SSRI sertraline relative to offspring of saline-exposed mice. Using a mouse model of in utero plus neonatal sertraline exposure, we observed lengthened peak-to-peak time of calcium oscillation (saline 784 ±76 ms; sertraline 1121 ± 130 ms, p<0.001) and decreased expression of critical genes in calcium regulation. We also observed significant up-regulation of specific miRNAs that modulate serotonin signaling in neonatal cardiac tissues (Slc6a4: miR-223-5p, miR-92a-2-5p, miR-182-5p; Htr2a: miR-34b-5p, miR-182-5p; Htr2b: miR-223-5p, miR-92a-2-5p, miR-337-5p) (p<0.05) with corresponding levels of the target mRNAs down-regulated (Slc6a4 0.73 ± 0.05; Htr2a 0.67 ± 0.04; Htr2b 0.72 ± 0.03; all p< 0.01), resulting in decreased production of the cognate proteins. Adult mice at 10 weeks showed altered cardiac parameters including decreased heart rates in males (saline 683 ± 8 vs sertraline 666 ± 6 beats per minute, p< 0.05) and ejection fraction in females (saline 83.9 ± 0.6% vs sertraline 80.6 ± 1.1%, p<0.05). These findings raise the question if sertraline exposure during development may increase the potential risk for cardiac disease when subjected to stress.

Phthalate exposure induces cell death and ferroptosis in neonatal microglial cells.

Phthalates are the materials used for plasticizing polyvinyl chloride. Di-(2-Ethylhexyl) phthalate (DEHP) is one of the phthalates most frequently used in a wide range of applications, including medical equipment such as endotracheal and feeding tubes, intravenous catheters, central lines, extracorporeal membrane oxygenation sets, total parenteral nutrition bags, blood product sets, and intravenous pump lines, respiratory sets in neonatal intensive care units (NICUs). Studies have shown that phthalates, including DEHP, can cross the placenta and blood-brain barrier, possibly leading to neurodevelopmental impairment in vitro and in vivo. However, the molecular mechanisms affected by phthalate exposure have not been explored in depth. This study aimed to illuminate the effects of DEHP on neuroinflammation at the molecular level using neonatal microglial cells as the model. Mouse BV-2 neonatal microglia cells were exposed to DEHP under controlled conditions. Cellular toxicity was assessed via a cell viability assay and specific markers were used to evaluate the apoptosis/necrosis, cellular iron content, reactive oxygen species (ROS), and organelle integrity. Proinflammatory proteins were quantified using enzyme-linked immunosorbent assay, while ferroptosis was assessed using a ferroptosis blocker, and affected gene expressions were determined using quantitative reverse-transcriptase real-time polymerase chain reaction (RT-PCR). The results revealed that high concentrations of DEHP exposure increased toxicity via increased levels of ROS and inflammation. Elevated ROS levels were observed to increase the tendency for mitochondrial-lysosomal disruption, bringing about apoptosis or necrosis. Moreover, iron homeostasis was dysregulated by DEHP, which putatively triggered ferroptosis in a dose-dependent manner. This study indicates that neonatal exposure to DEHP may be linked to neurodevelopmental impairment via inflammation-related cell death and ferroptosis. The prevalence of DEHP in NICU medical devices raises concerns about potential neurodevelopmental deficits, including disorders like autism and mental retardation. These findings highlight the urgency of addressing DEHP exposure in neonatal care.

Exploring the Impact of Developmental Clearance Saturation on Propylene Glycol Exposure in Adults and Term Neonates Using Physiologically Based Pharmacokinetic Modeling.

Propylene glycol (PG) is a pharmaceutical excipient which is generally regarded as safe (GRAS), though clinical toxicity has been reported. PG toxicity has been attributed to accumulation due to saturation of the alcohol dehydrogenase (ADH)-mediated clearance pathway. This study aims to explore the impact of the saturation of ADH-mediated PG metabolism on its developmental clearance in adults and neonates and assess the impact of a range of doses on PG clearance saturation and toxicity. Physiologically based pharmacokinetic (PBPK) models for PG in adults and term neonates were developed using maximum velocity (Vmax) and Michaelis-Menten's constant (Km) of ADH-mediated metabolism determined in vitro in human liver cytosol, published physicochemical, drug-related and ADH ontogeny parameters. The models were validated and used to determine the impact of dosing regimen on PG clearance saturation and toxicity in adults and neonates. The Vmax and Km of PG in human liver cytosol were 1.57 nmol/min/mg protein and 25.1 mM, respectively. The PG PBPK model adequately described PG PK profiles in adults and neonates. The PG dosing regimens associated with saturation and toxicity were dependent on both dose amount and cumulative in standard dosing frequencies. Doses resulting in saturation were higher than those associated with clinically observed toxicity. In individuals without impaired clearance or when PG exposure is through formulations that contain excipients with possible interaction with PG, a total daily dose of 100-200 mg/kg/day in adults and 25-50 mg/kg/day in neonates is unlikely to result in toxic PG levels or PG clearance saturation.

Exploring Indigenous Ways of Childbirth Management and its Perinatal Outcomes During Cyclonic Periods in Hilly Tribal Homebirth Settings: A Qualitative Observational Study

Objective This study explores the cultural-based management of childbirth vulnerabilities in the hilly regions during cyclone periods, where the land mass has been frequently exposed to floods during and aftermath of cyclones due to low-high cyclonic depressions in the Bay of Bengal coast. Methods The present study was a community-based qualitative observational study conducted for three weeks immediately after the two cyclonic periods occurred between October and December 2022. With the purposive sampling method, 21 postpartum mothers were selected on the inclusion criteria, of having had childbirth around the cyclonic period of ‘Sitrang’ (late October 2022) and ‘Mandous’ (early December 2022). Semi-structured in-depth interview schedules were employed to document socio-demographic profiles and probed for their cultural ways of managing childbirth complications and neonatal exposures to infections during the cyclonic period. Results Views of 21 mothers were coded into three themes with two sub-themes each according to repeated frequencies of information. The themes were (a) Striving for Safe Childbirths; (b) Surviving with Traditional Capacities; (c) Strength and Sustenance. The results indicated that home deliveries were considered safest over institutional deliveries except in the cases of complicated childbirths confirmed difficult by the traditional birth attendants (TBA). Rough climatic conditions compounded by geographical distance, lack of appropriate financial help and timely transportation facilities were the major prevailing factors influencing their childbirth practices during the cyclonic periods. Conclusion Disasters do not alone influence childbirth outcomes, but the evidence is still mixed. The expediency of birth technology has effectively managed childbirth vulnerabilities. Ensured sleep, rest and enough food had also been disturbed during and aftermath cyclones. The results showed an urgent need for focused planning on tribal areas for gestation, birthing and postpartum people during natural disasters.

Neonatal exposure to high d-galactose affects germ cell development in neonatal testes organ culture

Excess exogenous supplementation of d-galactose (d-gal), a monosaccharide and reducing sugar, generates reactive oxygen species (ROS), leading to cell damage and death. ROS accumulation is critical in aging. Therefore, d-gal-induced aging mouse models are used in aging studies. Herein, we evaluated d-gal’s effect on neonatal testis development using an in vitro organ culture method. Mouse testicular fragments (MTFs) derived from neonatal testes (postnatal day 5) were cultured with 500 mM d-gal for 5 days. d-gal-treated MTFs showed a significantly increased and decreased expression of undifferentiated and differentiated germ cell markers, respectively, with a substantial reduction in meiotic cells. In d-gal-exposed MTFs, expression levels of Sertoli cell markers (Sox9 and Wt1) increased, while those of StAR and 17β-HSD3, whose expressions are abundant in d-Gal treated adult Leydig cells, decreased. Additionally, the enzyme 3 β-HSD1, essential for steroidogenesis in Leydig cells, was significantly reduced in d-gal-exposed MTFs compared to that in controls.d-gal significantly increased the expression of Bad, Bax, and cleaved caspase-3 and -8. Via oxidative stress in MTF. Overall, d-gal negatively regulates germ cell and Leydig cell development in neonatal testes through pro-apoptotic mechanisms and ROS.

Decreased Liver Kinase B1 Expression and Impaired Angiogenesis in a Murine Model of Bronchopulmonary Dysplasia.

Bronchopulmonary dysplasia (BPD) is characterized by impaired lung alveolar and vascular growth. We investigated the hypothesis that neonatal exposure to hyperoxia leads to persistent BPD phenotype caused by decreased expression of liver kinase B1 (LKB1), a key regulator of mitochondrial function. We exposed mouse pups from Postnatal Day (P)1 through P10 to 21% or 75% oxygen. Half of the pups in each group received metformin or saline intraperitoneally from P1 to P10. Pups were killed at P4 or P10 or recovered in 21% O2 until euthanasia at P21. Lung histology and morphometry, immunofluorescence, and immunoblots were performed to detect changes in lung structure and expression of LKB1; downstream targets AMPK, PGC-1α, and electron transport chain (ETC) complexes; and Notch ligands Jagged 1 and delta-like 4. LKB1 signaling and invitro angiogenesis were assessed in human pulmonary artery endothelial cells (exposed to 21% or 95% O2 for 36 hours. Levels of LKB1, phosphorylated AMPK, PGC-1α, and ETC complexes were decreased in lungs at P10 and P21 in hyperoxia. Metformin increased LKB1, phosphorylated AMPK, PGC-1α, and ETC complexes at P10 and P21 in pups exposed to hyperoxia. Radial alveolar count was decreased, and mean linear intercept increased in pups exposed to hyperoxia at P10 and P21; these were improved by metformin. Lung capillary density was decreased in hyperoxia at P10 and P21 and was increased by metformin. In vitro angiogenesis was decreased in human pulmonary artery endothelial cells by 95% O2 and was improved by metformin. Decreased LKB1 signaling may contribute to decreased alveolar and vascular growth in a mouse model of BPD.

Neonatal and early infancy antibiotic exposure is associated with childhood atopic dermatitis, wheeze and asthma

Antibiotics are frequently administered in the neonatal period and early infancy. Little is known about the long-term health consequences of early life antibiotic exposure. The objective is to investigate the association between neonatal and early life (0–6 months) antibiotic treatment and the development of atopic dermatitis, asthma and the use of inhaled corticosteroid medication later in childhood. We analyzed data obtained from hospital records and national registers in a cohort of 11,255 children. The association between early antibiotic exposure and the outcomes were analyzed using logistic regression. Confounding factors were included in the model. Neonatal antibiotic therapy for confirmed infection was associated with childhood atopic dermatitis (adjusted odds ratio 1.49; 95% confidence interval 1.15–1.94). Antibiotic therapy by six months of age was more common in children developing atopic dermatitis (adjusted odds ratio 1.38; 95% confidence interval 1.15–1.64), asthma (adjusted odds ratio 1.56; 95% confidence interval 1.32- 1.85) and inhaled corticosteroid medication use (adjusted odds ratio 1.88; 95% confidence interval 1.66–2.13). Conclusions: Neonatal antibiotic therapy for confirmed or clinically diagnosed infection is associated with increased risk of atopic dermatitis later in childhood. Antibiotic treatment before six months of age is associated with atopic dermatitis, asthma and inhaled corticosteroid use.What is known:• The use of antibiotics early in life has been associated with an increased risk of developing atopic dermatitis or asthma.• Confounding by indication or reverse causation may underlie the observed associations.What is new:• Our results demonstrate that neonatal antibiotic therapy for confirmed or clinically diagnosed infection was associated with increased risk of atopic dermatitis and antibiotic treatment before six months of age was associated with atopic dermatitis, asthma and inhaled corticosteroid use in analyses adjusted for confounding factors.

Postnatal Allergic Inhalation Induces Glial Inflammation in the Olfactory Bulb and Leads to Autism-Like Traits in Mice

Autism spectrum disorder (ASD) is one of the most prevalent neurodevelopmental disorders. To explore its pathophysiology, we investigated the association between neonatal allergic exposure and behavioral changes. Adult female C57BL/6J mice were immunized with adjuvant (aluminum hydroxide) or ovalbumin emulsified with adjuvant. After immunization, the mice were mated, and offspring were born at full term. The postnatal dams and infants were then simultaneously exposed to an allergen (ovalbumin) or vehicle via inhalation. After weaning, behavioral testing and histopathological analyses were conducted on male offspring. Compared with the vehicle-exposed offspring, the ovalbumin-exposed offspring had decreased sociability and increased repetitive behavior, thus representing an ASD-like phenotype in mice. Moreover, histopathological analyses revealed that the ovalbumin-exposed mice had increased astroglial, microglial, and eosinophilic infiltration in the olfactory bulb, as well as increased eosinophils in the nasal mucosa. The ovalbumin-exposed mice also had decreased dendritic spine density and a lower proportion of mature spines, suggesting the impairment of stimulus-induced synaptogenesis. In conclusion, postnatal allergic exposure induced an ASD-like phenotype, as well as allergic rhinitis, which was followed by glial inflammation in the olfactory bulb parenchyma.

Neonatal Cannabidiol Exposure Impairs Spatial Memory and Disrupts Neuronal Dendritic Morphology in Young Adult Rats.

Introduction: Early life is a sensitive period for brain development. Perinatal exposure to cannabis is increasingly linked to disruption of neurodevelopment; however, research on the effects of cannabidiol (CBD) on the developing brain is scarce. In this study, we aim to study the developmental effects of neonatal CBD exposure on behavior and dendritic architecture in young adult rats. Materials and Methods: Male and female neonatal Sprague Dawley rats were treated with CBD (50 mg/kg) intraperitoneally on postnatal day (PND) 1, 3, and 5 and evaluated for behavioral and neuronal morphological changes during early adulthood. Rats were subjected to a series of behavioral tasks to evaluate long-term effects of neonatal CBD exposure, including the Barnes maze, open field, and elevated plus maze paradigms to assess spatial memory and anxiety-like behavior. Following behavioral evaluation, animals were sacrificed, and neuronal morphology of the cortex and hippocampus was assessed using Golgi-Cox (GC) staining. Results: Rats treated with CBD displayed a sexually dimorphic response in spatial memory, with CBD-treated females developing a deficit but not males. CBD did not elicit alterations in anxiety-like behavior in either sex. Neonatal CBD caused an overall decrease in dendritic length and spine density (apical and basal) in cortical and hippocampal neurons in both sexes. Sholl analysis also revealed a decrease in dendritic intersections in the cortex and hippocampus, indicating reduced dendritic arborization. Conclusions: This study provides evidence that neonatal CBD exposure perturbs normal brain development and leads to lasting alterations in spatial memory and neuronal dendrite morphology in early adulthood, with sex-dependent sensitivity.

A single exposure to brivaracetam or perampanel does not cause cell death in neonatal rats.

Exposure to a range of anti-seizure medications (ASMs) during early brain development adversely impacts neurodevelopmental outcomes in both animal models and in clinical studies. Many ASMs, including phenobarbital, phenytoin, valproate (VPA), and benzodiazepines, are associated with acute neurotoxicity (cell death), impaired synaptic development, and long-term behavioral changes following gestational or neonatal exposure in animals. This is mirrored in clinical studies which show lasting neurodevelopmental deficits following early-life or gestational exposure to these drugs. Brivaracetam (BRV) and perampanel (PER) are two newer generation anti-seizure medications and are of interest based on their mechanisms of action (SV2A modulator, AMPA antagonist, respectively), as other drugs with these mechanisms of action do not trigger acute neurotoxicity. Both BRV and PER show anti-seizure efficacy in developing animals, but potential neurotoxicity of these drugs is unexplored. To address this gap, we treated postnatal day (P)7 Sprague-Dawley rats with BRV (20, 40, 80 mg/kg) and PER (0.1, 0.9, 2.7 mg/kg), and assessed the induction of cell death across a range of vulnerable brain regions 24 h after exposure. Cell death was assessed using pathogreen staining. In each of the regions examined (dorsal striatum, nucleus accumbens, motor cortex, cingulate cortex, lateral thalamus, septum, hippocampus), VPA, which served as a positive control, significantly increased cell death as measured by the numer of pathogreen positive cells. By contrast, neither BRV nor PER increased the number of pathogreen positive cells in any region examined. Our results suggest that BRV and PER may have a positive safety profile-at least with respect to acute induction of cell death - and therefore may offer a safer option for the treatment of early life seizures.

Neonatal limited bedding and nesting experience may lead to a sex-dependent increase in panic-like defensive behaviours in adult mice.

In humans, adverse physical and/or psychological traumas in childhood may predispose to developing psychiatric disorders in adulthood, including panic disorder. To model early life adversity in mice, we subjected male and female C57BL/6J mice to a limited bedding and nesting (LBN) protocol between postnatal days 2-9 and investigated its effect on responsiveness to panicogenic challenges in adulthood. Panic-like escape behaviour was assessed during exposure to a high concentration of CO2 (20%) or in the beetle mania task (BMT), used to model respiratory and non-respiratory-related types of panic respectively. Neonatal exposure to LBN increased panic-like jumping during the CO2 challenge in male but not female mice. In an initial pharmacological validation of the BMT as a panic-inducing paradigm, undirected jumping and horizontal escape behaviours were reduced significantly by the panicolytic alprazolam (0.05 and 0.1mg.kg-1 i.p.) whilst tolerance to the close proximity of the aversive robo-beetle increased. The anxiolytic diazepam (1mg.kg-1i.p.) reduced only the number of horizontal escape attempts. In both sexes, previous experience of LBN significantly enhanced the number of horizontal escape episodes, indicating a pro-panic phenotype. Directed escape to access a safe ledge on the wall of the test arena, which was seen only in males, was also reduced significantly following LBN. These findings indicate that early life adversity produced by fragmented and unpredictable maternal care promotes a sex-specific increase in susceptibility to panic-like behaviour in adulthood. Whilst non-respiratory-related panic-like behaviour was enhanced in both sexes, females were resilient to respiratory-related challenges.

Neonatal paw pricking alters adolescent behavior in a sex-dependent manner and sucrose partially remediates the effects

Neonatal exposure to noxious stimuli such as repeated heel lances can cause behavior changes. In the NICU sucrose given prior to procedures attenuates the immediate behavioral response to noxious stimuli but may not ameliorate the long-term consequences, and treatment with 24 % sucrose can brain structure and behavior in adult rodents. We used a rat model to determine whether paw pricks during the neonatal period alter social interaction and/or paw withdrawal thresholds (PWT) in adolescence, and if 7 % sucrose mitigates these effects. One male and one female pup per litter was assigned to each of six experimental groups (no paw prick (control), 1 paw prick (1PP), or 2PP, ± sucrose). Hind paws were pricked once or twice each day between postnatal day (P)3 and P10. Social behavior and PWT were tested in adolescence using the modified social interaction test and von Frey filaments, respectively. Social behavior was altered in the 2PP group; total time interacting was lower in 2PP rats, primarily due to less time sniffing a play partner. Sucrose did not mitigate effects of paw prick but trended to alter social behaviors in males; it decreased time in contact but increased social motivation (movement toward a play partner). PWTs were higher in 2PP animals, this was not altered by sucrose. Thus, rat pups exposed to paw pricks in the neonatal period have some altered behaviors in adolescence. The nature of the behavioral changes is sex-dependent, but sucrose did not mitigate these changes.

Astrocyte extracellular matrix modulates neuronal dendritic development.

Major developmental events occurring in the hippocampus during the third trimester of human gestation and neonatally in altricial rodents include rapid and synchronized dendritic arborization and astrocyte proliferation and maturation. We tested the hypothesis that signals sent by developing astrocytes to developing neurons modulate dendritic development in vivo. We altered neuronal development by neonatal (third trimester-equivalent) ethanol exposure in mice; this treatment increased dendritic arborization in hippocampal pyramidal neurons. We next assessed concurrent changes in the mouse astrocyte translatome by translating ribosomal affinity purification (TRAP)-seq. We followed up on ethanol-inhibition of astrocyte Chpf2 and Chsy1 gene translation because these genes encode for biosynthetic enzymes of chondroitin sulfate glycosaminoglycan (CS-GAG) chains (extracellular matrix components that inhibit neuronal development and plasticity) and have not been explored before for their roles in dendritic arborization. We report that Chpf2 and Chsy1 are enriched in astrocytes and their translation is inhibited by ethanol, which also reduces the levels of CS-GAGs measured by Liquid Chromatography/Mass Spectrometry. Finally, astrocyte-conditioned medium derived from Chfp2-silenced astrocytes increased neurite branching of hippocampal neurons in vitro. These results demonstrate that CS-GAG biosynthetic enzymes in astrocytes regulates dendritic arborization in developing neurons.

Health and well-being of maturing adults with classic galactosemia.

Long-term outcomes in classic galactosemia (CG) have been studied previously, but all prior studies have relied on cohorts of patients that were small in number, or heavily skewed toward children and young adults, or both. Here, we extend what is known about the health and well-being of maturing adults with CG by analyzing the results of anonymous custom surveys completed by 92 affected individuals, ages 30-78, and 38 unaffected sibling controls, ages 30-79. The median age for patients was 38.5 years and for controls was 41 years. These study participants hailed from 12 different countries predominantly representing Europe and North America. Participants reported on their general life experiences and outcomes in seven different domains including: speech/voice/language, cognition, motor function, cataracts, bone health, psychosocial well-being, and gastrointestinal health. We also queried women about ovarian function. Our results indicated a prevalence of long-term complications across all outcome domains that aligned with levels previously reported in younger cohorts. Given the sample size and age range of participants in this study, these findings strongly suggest that the adverse developmental outcomes commonly linked to CG are not progressive with age for most patients. We also tested four candidate modifiers for possible association with each of the outcomes followed, including: days of neonatal milk exposure, rigor of dietary galactose restriction in early childhood, current age, and home continent. We observed no associations that reached even nominal significance, except for the following: cataracts with neonatal milk exposure (p = 2.347e-04), cataracts with age (p = 0.018), and bone health with home continent (p = 0.03).

Rosiglitazone Promotes Oligodendrocyte Development and Myelin Formation of Repeated Neonatal Sevoflurane Exposure via PPARγ Signaling.

Sevoflurane is one of the most commonly used general anesthetics for children and infants. Recent research indicates that repeated exposure to sevoflurane in neonates induces cognitive and fine motor deficits. Peroxisome proliferator-activated receptor-γ (PPARγ) agonists have garnered significant attention as potential therapies for a variety of neurological conditions. In this research, we evaluated whether pretreatment with rosiglitazone in neonatal mice could address myelination defects, cognitive impairment, and fine motor dysfunction via PPARγ. The mice were exposed to 3% sevoflurane for 2h on postnatal days 6-8 (P6-P8). Behavioral tests were conducted from P29 to P34. Additionally, we evaluated morphological and functional changes related to myelin. Our results showed that rosiglitazone pretreatment significantly ameliorated the cognitive and fine motor impairments of repeated neonatal sevoflurane exposure. In addition, rosiglitazone pretreatment promoted oligodendrocyte precursor cells (OPCs) differentiation and myelination. This suggests that rosiglitazone may be used in clinical settings to enhance the security of neonatal sevoflurane exposure. Furthermore, PPARγ and fatty acid synthase (FASN) may be mediators for rosiglitazone, which alleviates myelination defects, cognitive impairment, and fine motor dysfunction.

Role of sex as a biological variable in neonatal alveolar macrophages

The lung macrophages play a crucial role in health and disease. Sexual dimorphism significantly impacts the phenotype and function of tissue-resident macrophages. The primary mechanisms responsible for sexually dimorphic outcomes in bronchopulmonary dysplasia (BPD) remain unidentified. We tested the hypothesis that biological sex plays a crucial role in the transcriptional state of alveolar macrophages, using neonatal murine hyperoxia-induced lung injury as a relevant model for human BPD. The effects of neonatal hyperoxia exposure (95 % FiO2, PND1-5: saccular stage) on the lung myeloid cells acutely after injury and during normoxic recovery were measured. Alveolar macrophages (AM) from room air- and hyperoxia exposed from male and female neonatal murine lungs were subjected to bulk-RNA Sequencing. AMs are significantly depleted in the hyperoxia-exposed lung acutely after injury, with subsequent recovery in both sexes. The transcriptome of the alveolar macrophages is impacted by neonatal hyperoxia exposure and by sex as a biological variable. Pathways related to DNA damage and interferon-signaling were positively enriched in female AMs. Metabolic pathways related to glucose and carbohydrate metabolism were positively enriched in the male AMs, while oxidative phosphorylation was negatively enriched. These pathways were shared with monocytes and airway macrophages from intubated male and female human premature neonates.

Triggering Receptor Expressed on Myeloid Cells 2 Alleviated Sevoflurane-Induced Developmental Neurotoxicity via Microglial Pruning of Dendritic Spines in the CA1 Region of the Hippocampus.

Sevoflurane induces developmental neurotoxicity in mice; however, the underlying mechanisms remain unclear. Triggering receptor expressed on myeloid cells 2 (TREM2) is essential for microglia-mediated synaptic refinement during the early stages of brain development. We explored the effects of TREM2 on dendritic spine pruning during sevoflurane-induced developmental neurotoxicity in mice. Mice were anaesthetized with sevoflurane on postnatal days 6, 8, and 10. Behavioral performance was assessed using the open field test and Morris water maze test. Genetic knockdown of TREM2 and overexpression of TREM2 by stereotaxic injection were used for mechanistic experiments. Western blotting, immunofluorescence, electron microscopy, three-dimensional reconstruction, Golgi staining, and whole-cell patch-clamp recordings were performed. Sevoflurane exposures upregulated the protein expression of TREM2, increased microglia-mediated pruning of dendritic spines, and reduced synaptic multiplicity and excitability of CA1 neurons. TREM2 genetic knockdown significantly decreased dendritic spine pruning, and partially aggravated neuronal morphological abnormalities and cognitive impairments in sevoflurane-treated mice. In contrast, TREM2 overexpression enhanced microglia-mediated pruning of dendritic spines and rescued neuronal morphological abnormalities and cognitive dysfunction. TREM2 exerts a protective role against neurocognitive impairments in mice after neonatal exposures to sevoflurane by enhancing microglia-mediated pruning of dendritic spines in CA1 neurons. This provides a potential therapeutic target in the prevention of sevoflurane-induced developmental neurotoxicity.

Altered ovarian reserve in Ewe lambs exposed to a glyphosate-based herbicide

Glyphosate-based herbicides (GBHs) are considered endocrine disruptors that affect the female reproductive tract of rats and ewe lambs. The present study aimed to investigate the impact of neonatal exposure to a low dose of a GBH on the ovarian follicular reserve of ewe lambs and the response to a gonadotropic stimulus with porcine FSH (pFSH). To this end, ewe lambs were orally exposed to an environmentally relevant GBH dose (1 mg/kg/day) or vehicle (Control) from postnatal day (PND) 1 to PND14, and then some received pFSH (50 mg/day) between PND41 and 43. The ovaries were dissected, and follicular types and gene expression were assessed via RT-PCR. The treatments did not affect the body weight of animals, but pFSH increased ovarian weight, not observed in GBH-exposed lambs. GBH-exposed lambs showed decreased Estrogen receptor-alpha (56%), Progesterone receptor (75%), Activin receptor II (ACVRII) (85%), and Bone morphogenetic protein 15 (BMP15) (88%) mRNA levels. Control lambs treated with pFSH exhibited downregulation of Follistatin (81%), ACVRII (77%), BMP15 (93%), and FSH receptor (FSHr) (72%). GBH-exposed lambs treated with pFSH displayed reduced ACVRII (68%), BMP15 (81%), and FSHr (50%). GBH-exposed lambs also exhibited decreased Anti-Müllerian hormone expression in primordial and antral follicles (27%) and (54%) respectively) and reduced Bone morphogenetic protein 4 (31%) expression in primordial follicles. Results suggest that GBH disrupts key follicular development molecules and interferes with pFSH action in ovarian receptors, decreasing the ovarian reserve. Future studies should explore whether this decreased ovarian reserve impairs adult ovarian function and its response to superovulation stimuli.