Postnatal Day Research Articles

Effect of rifampicin on Toll-like receptor system gene expression in brain structures of rats with prenatal alcohol exposure

Alcohol intake during pregnancy may affect the normal course of fetal development, causing the symptoms of fetal alcohol spectrum disorders (FASD). There is evidence that a number of prenatal pathologic conditions exhibit altered expression of several pro- and anti-inflammatory cytokines. In our study, we focused on studying expression of numerous pro- and anti-inflammatory cytokine genes in the forebrain and temporal regions of rat brain during the postnatal development, thus modeling prenatal alcohol exposure effects (PAE). We also evaluated expression of genes associated with regulation of genes controlling expression of pro- and anti-inflammatory cytokines. Moreover, the objectives of our study included pharmacological correction of the observed changes by rifampicin (Rif), a potential pharmacological agent which had a neuroprotective effect shown by other studies,. The experimental model of PAE was produced by oral intake of 15% ethanol solution to pregnant female rats throughout pregnancy. The drug injections were performed to the pups from the 1 to the 7 postnatal days. Brain structures were sampled for gene expression analysis on the 8 postnatal day. The results of the study showed distinct changes in Tlr3 and Tlr4 gene expression in anterior and temporal lobes of brain on the 8 day of postnatal development. Expression of Myd88 and Ticam genes showed multidirectional changes among the studied brain structures of PAE rats. The increased mRNA level of proinflammatory genes was noted. Usage of Rif in experiments showed the ability of Rif (50 mg/kg) to correct the observed long-term pathological changes in the expression of the genes under study. It is of interest to study the dose-dependent effect in the future, as well as to investigate the revealed changes at the level of protein analysis. In future studies, it seems important to evaluate TLR signaling system in other brain structures with PAE, as well as at different terms of postnatal development in ontogenesis.

Human umbilical cord mesenchymal stem cell-derived exosomes combined with mouse nerve growth factor can more effectively ameliorate the motor disorder and brain pathological injury in mice with cerebral palsy.

Cerebral palsy (CP) is a neurodevelopmental disorder and motor disorder syndrome. It has been confirmed that mesenchymal stem cells (MSCs) and mouse nerve growth factor (mNGF) can repair brain tissue damage and nerve injury; however, exosomes derived from healthy cells may have a comparable therapeutic potential as the cells themselves. The purpose of this study was to explore the improvement effect of human umbilical cord mesenchymal stem cell (hUC-MSCs)-derived exosomes on a CP model and determine whether there is a synergistic effect when combined with mNGF. Exosomes were isolated from hUC-MSCs and examined using transmission electron microscopy (TEM), particle size and western blot (WB). A total of 38 BALB/c mice (male, postnatal day 6 (PND6)) were randomly divided into 5 groups: sham group, CP group, CP-exo group, CP-mNGF group, and CP-exo-mNGF group. Hypoxic induction after unilateral common carotid artery ligation combined with lipopolysaccharide (LPS) infection was used to construct the CP model. Pathological damage to neuron tissue and synaptic structures in the hippocampus was confirmed using light microscopy after hematoxylin-eosin (H&E) staining and TEM, respectively. Survival of neurons was evaluated using Nissl staining. Western blot was applied to monitor PSD-95 and synaptophysin (SYN) protein levels. This study indicated that exosomes released by hUC-MSCs ameliorated brain damage and synaptic structure destruction in CP mice induced by hypoxic ischemia and LPS infection. When combined with mNGF, there was more effective improvement. In the CP group, neuronal function was severely impaired; however, hUC-MSCs-derived exosomes and mNGF improved it. PSD-95 and SYN proteins were presynaptic and postsynaptic proteins, respectively. Interestingly, the PSD-95 and SYN protein levels were significantly lower in the CP mice, but with the addition of hUC-MSCs-exosomes or mNGF, they increased significantly, especially in the CP-exo-mNGF group. The nerve function injury in CP can be improved the most when hUC-MSCs-derived exosomes are combined with mNGF through intraperitoneal (ip.) administration.

Maternal exposure to dim light at night induces behavioral alterations in the adolescent and adult offspring Wistar rat.

Access to electric light has exposed living organisms to varying intensities of light throughout the 24h day. Dim light at night (DLAN) is an inappropriate signal for the biological clock, which is responsible for the circadian organization of physiology. During the gestational period, physiological adaptations occur to ensure a successful pregnancy and optimal fetal development. Environmental maternal conditions, such as disruptions of maternal circadian rhythms, could negatively affect offspring health. We have previously demonstrated that exposure of female Wistar rats to DLAN results in circadian, metabolic, and behavioral alterations. A relevant behavior during adolescence is social play, primarily regulated by the nucleus accumbens (NAc) which is crucial for the proper performance of important behaviors in adulthood. Throughout development, microglia are responsible for the remodeling of diverse brain regions via synaptic pruning. During adolescence, this process occurs within the NAc, where immune-mediated remodeling directly impacts social play behavior. This study investigated the effects of maternal exposure to DLAN or a light-dark cycle (LD) before (5weeks) and during the gestational period (21-23days) on the metabolism and behavior of offspring in adolescence and adulthood. Body mass was measured every 5 days from postnatal day 1 (PN1) to PN25 and every 10 days from PN40 to PN90; food consumption was monitored weekly from PN40 to PN90. Social play behavior was evaluated at PN40. The quantification and morphology of microglia in the NAc were measured on PN30. An open field test was conducted at PN60, and anhedonia test was assessed at PN90. Male and female offspring from mothers exposed to DLAN showed increased body mass gain at PN25. DLAN male offspring had lower food consumption, while DLAN females exhibited increased food consumption. In social play behavior, no differences were found between DLAN and LD female offspring. In contrast, DLAN male offspring exhibited a significant decrease in social play behavior compared to LD animals, which was associated with higher numbers of microglia in the NAc that had more ramified morphology. Importantly, at PN90, DLAN offspring presented increased anxiety-like behaviors. These results demonstrate that DLAN exposure induces intergenerational behavioral alterations that persist until adulthood.

Necrotizing enterocolitis causes increased ileal goblet cell loss in Wnt2b KO mice.

WNT2B is Wnt ligand which is able to support intestinal stem cells (ISC) in culture and support the intestinal epithelium in vivo. We have previously shown that WNT2B is critical for resistance to colitis, but not small intestinal injury, in the adult mouse. WNT2B is thought to coordinate with WNT3 in supporting ISC, and we have also shown that WNT3 expression is low in the early postnatal ileum in mice. Here, we hypothesized that WNT2B may be more critical in the small intestine during early development, and we challenged Wnt2b KO mice and controls with experimental necrotizing enterocolitis (NEC) on postnatal days 5-8. Wnt2b KO mice had similar ileum histology and injury scores to control mice. Molecular analyses showed that Wnt2b KO mice have differences in Lgr5 and Tlr4 expression compared to wild type controls in untreated conditions, but under experimental NEC expression of epithelial markers and inflammatory genes associated with NEC were similar to wild type. Periodic acid Schiff positive cells were lower in the villi of Wnt2b KO mice during NEC, however expression of goblet cell markers was not different compared to wild type mice. We also used an organoid-based NEC model to highlight the epithelium in isolation and also found no impact of WNT2B KO in the setting of NEC. These data further affirm that WNT2B is critical for inflammation responses in the mouse colon, but does not appear to play a major role in the small intestine, no matter the developmental period.

Redirection of Care for Neonates with Hypoxic-Ischemic Encephalopathy Receiving Therapeutic Hypothermia.

Background/Objectives: Hypoxic-ischemic encephalopathy (HIE) in late preterm and term neonates accounts for neonatal mortality and unfavorable neurodevelopmental outcomes in survivors despite therapeutic hypothermia (TH) for neuroprotection. The circumstances of death in neonates with HIE, including involvement of neonatal palliative care (NPC) specialists and neurodevelopmental follow-up at 18-24 months in survivors, warrant further evaluation. Methods: A retrospective multicenter cohort study including neonates ≥ 35 weeks gestational age with moderate to severe HIE receiving TH, registered in the Swiss National Asphyxia and Cooling Register between 2011 and 2021. Neurodevelopmental follow-up at 18-24 months in survivors was assessed. The groups of survivors and deaths were compared regarding perinatal demographic and HIE data. Prognostic factors leading to redirection of care (ROC) were depicted. Results: A total of 137 neonates were included, with 23 (16.8%) deaths and 114 (83.2%) survivors. All but one death (95.7%) occurred after ROC, with death on a median of 3.5 (2-6) days of life. Severe encephalopathy was indicated by a Sarnat score of 3 on admission, seizures were more frequent, and blood lactate values were higher on postnatal days 1 to 4 in neonates who died. Lactate in worst blood gas analysis (unit-adjusted odds ratio 1.25, 95% CI 1.02-1.54, p = 0.0352) was the only variable independently associated with ROC. NPC specialists were involved in one case. Of 114 survivors, 88 (77.2%) had neurodevelopmental assessments, and 21 (23.9%) of those had unfavorable outcomes (moderate to severe disability). Conclusions: Death in neonates with moderate to severe HIE receiving TH almost exclusively occurred after ROC. Parents thus had to make critical decisions and accompany their neonate at end-of-life within the first week of life. Involvement of NPC specialists is encouraged in ROC so that there is continuity of care for the families whether the neonate survives or not.

Effect of gestational age on clinical features in necrotizing enterocolitis-associated intestinal perforation.

To investigate the clinical features of necrotizing enterocolitis-associated intestinal perforation (NEC-IP) in neonates with different gestational ages (GAs). Furthermore, we also want to identify the risk factors of poor prognosis for these patients. The retrospective study of patients with NEC-IP was conducted with basic information, comorbidity, intraoperative findings, related treatment, and prognosis. According to the GA, patients were divided into three groups: early (GA: 28-<32 weeks, Group 1), mid-term (GA: 32-<34 weeks, Group 2), and late (GA: 34-<37 weeks, Group 3). The clinical features of the three groups were analyzed, and risk factors for poor prognosis were identified. Of the 113 cases, the number of cases in Groups 1 to 3 was 36 (31.9%), 44 (38.9%), and 33 (29.2%), respectively; and the overall proportion of poor prognosis was 19.4% (22/113). For basic information, the birth weight of Group 1 was lower than that of Group 2 and Group 3, while the postnatal day at the time of surgery of NEC and the onset age were higher than that of Group 2 (onset age: G1 12.0[7.00;20.5], G2 9.00[4.00;13.0]; postnatal day at the time of surgery: G1 22.0[13.8;27.2], G2 13.0[8.00;21.0]) (P < 0.016). For comorbidity, the incidence of sepsis, coagulopathy, type of (congenital heart disease) CHD, and hypoproteinemia in Group 1 was higher than that in Group 2 (all P < 0.016), and the incidence of respiratory failure, hypoproteinemia in Group 1 was higher than that in Group 3 (all P < 0.016). For related treatment, the usage rate of vasoactive substances and mechanical ventilation in Group 1 was higher than that of Group 2 and Group 3 (all P < 0.016). By Lasso and Logistic regression analysis, we found that GA (OR: 0.274, 95%CI: 0.078-0.796), sepsis (OR: 7.955, 95%CI: 1.424-65.21), coagulopathy (OR: 19.51, 95%CI: 3.393-179.1), CHD (OR: 6.99, 95%CI: 1.418-54.83) and diseased bowel segment (OR: 2.804, 95%CI: 1.301-7.316) were the independent factors for poor prognosis (all P < 0.05). The clinical features of NEC-IP patients differ based on GA, particularly in terms of CHD type, postnatal day at the time of surgery, utilization of vasoactive substances, and prognosis. Furthermore, GA, sepsis, coagulopathy, CHD, and diseased bowel segment are independent factors for poor prognosis of patients with NEC-IP.

Association of breast milk microbiota and metabolites with neonatal jaundice.

Breast milk is the primary source of nutrition during early life, and existing research indicates that the development of jaundice in breastfed newborns may be linked to specific nutrients or bioactive substances present in breast milk. However, the association between the microbiota and small-molecule metabolites in breast milk and the development of neonatal jaundice remains unproven. This study aimed to investigate the development of jaundice in breastfed neonates in relation to breast milk microbiota and metabolites. Based on the conditions of exclusive breastfeeding, we selected healthy newborns without significant jaundice and their mothers on day 4 (96-120 h after birth) as the healthy control group, and jaundiced newborns and their mothers as the jaundice group. Breast milk samples were collected from mothers in both groups on postnatal day 4 and analyzed for microbiota and small-molecule metabolites using 16S rRNA gene sequencing and an liquid chromatography-tandem mass spectrometry techniques. A total of 104 mother-child pairs were included in the study, of which 51 pairs were in the healthy control group and the other 53 pairs were in the jaundice group. Our results demonstrated that there was no significant difference between the species composition and diversity of the breast milk flora in the healthy control and jaundice groups. At the genus level, the abundance of Lactobacillus, Ackermannia, and Bifidobacterium was significantly higher in the breast milk of the healthy control group than in the jaundice group. Metabolomics analysis revealed a total of 27 significantly different metabolites between the two groups. Notably, breast milk from the healthy control group had elevated levels of 24 metabolites, predominantly lipids family, including sphingolipids, phospholipids, and fatty acid derivatives. This study suggests that there is a link between the development of neonatal jaundice and breast milk microbiota and metabolites. Breast milk from mothers of healthy newborns contains higher levels of beneficial bacteria and lipid family compared to mothers of newborns with jaundice. This study offers new insights into the relationship between breastfeeding and neonatal jaundice.

A New Leydig Cell-Exclusive Cre Line Allows Lineage Tracing of Fetal and Adult Leydig Cell Populations in the Mouse.

Leydig cells produce hormones that are required for male development, fertility, and health. Two Leydig cell populations produce these hormones but at different times during development: fetal Leydig cells, which are active during fetal life, and adult Leydig cells, which are functional postnatally. Historically, our ability to understand the origin and function of Leydig cells has been made difficult by the lack of genetic models to exclusively target these cells. Taking advantage of the Leydig cell-exclusive expression pattern of the Insl3 gene, we used a CRISPR/Cas9 gene-editing strategy to knock-in iCre recombinase into the mouse Insl3 locus. To demonstrate the Leydig cell-exclusive nature of our iCre line, lineage-tracing experiments were performed by crossing Insl3iCre mice with a Rosa26LoxSTOPLox-TdTomato reporter. iCre activity was restricted to male offspring. TdTomato fluorescence was detected both in fetal and adult Leydig cells and colocalized with CYP17A1, a classic Leydig cell marker. Prior to birth, fluorescence was observed in fetal Leydig cells beginning at embryonic day 13.0. Fluorescence was also detected in adult Leydig cells starting at postnatal day 5 and continuing to the mature testis. Fluorescence was not detected in any other fetal or adult tissue examined, except for the unexpected finding that the adrenal cortex contains some Insl3-expressing Leydig-like cells. Our Leydig cell-exclusive iCre line therefore constitutes an invaluable new tool to study not only the origin of Leydig cells but also to target genes that have been long-proposed to be important for the development and functioning of these critical endocrine cells.

The Impact of Coenzyme Q10 on Cognitive Dysfunction, Antioxidant Defense, Cholinergic Activity, and Hippocampal Neuronal Damage in Monosodium Glutamate-Induced Obesity

Background: Obesity, a rising global health issue, is linked to numerous disorders, including cognitive impairment. Objectives: This study investigates the effects of coenzyme Q10 (Co-Q10) on cognitive performance, antioxidant defense, cholinergic activity, and hippocampal neuron damage in rats rendered obese by monosodium glutamate (MSG) exposure. Methods: Forty-eight neonatal male Wistar rats were randomly assigned to one of four groups: Control, MSG, MSG + Q10-10, and MSG + Q10-20. Monosodium glutamate (4 g/kg BW) was administered subcutaneously into the cervical region from postnatal day (PND) 2 to PND 10. Coenzyme Q10 (10 mg/kg BW and 20 mg/kg BW) was administered intraperitoneally from PND 30 to PND 42. At the end of the treatment period, working memory and avoidance learning tests were conducted. Anthropometric data were collected, followed by evaluations of hippocampal catalase (CAT), superoxide dismutase (SOD), acetylcholinesterase (AChE), glutathione peroxidase (GPx), and malondialdehyde (MDA) levels. The density of apoptotic/dark neurons (DN) in the CA₁ and CA₃ regions of the hippocampus was also assessed. Results: Monosodium glutamate treatment increased Body Mass Index (BMI) and Lee Index, impaired working memory and avoidance learning, and reduced CAT, SOD, and GPx activities. Additionally, MSG exposure led to elevated MDA levels, increased AChE activity, and higher DN density in the CA₁ and CA₃ hippocampal regions. Treatment with Co-Q10 resulted in a decrease in BMI, enhanced memory and learning, noteworthy increases in CAT, SOD, and GPx activities in the hippocampus, and reductions in MDA levels, AChE activity, and DN density in the CA₁ and CA₃ regions. Conclusions: Coenzyme Q10 mitigates hippocampal neuronal damage and improves cognitive function in MSG-induced obesity, primarily through its antioxidant and AChE inhibitory properties.

MYO7A is required for the functional integrity of the mechanoelectrical transduction complex in hair cells of the adult cochlea

Myosin-VIIA (MYO7A) is an unconventional myosin responsible for syndromic (Usher 1B) or nonsyndromic forms of deafness in humans when mutated. In the cochlea, MYO7A is expressed in hair cells, where it is believed to act as the motor protein tensioning the mechanoelectrical transducer (MET) channels, thus setting their resting open probability (Po). However, direct evidence for this unique role for an unconventional myosin in mature hair cells is lacking. Here, we show that MYO7A has a distinct role in hair cells, being crucial for the structural integrity of hair bundles. Postnatal deletion of Myo7a leads to 87 to 96% reduction in MYO7A from hair cells by postnatal day 20 (P20), without affecting hearing function. During the following week, mice showed progressive decline in both hearing function and MET current amplitude in hair cells without affecting the resting Po and calcium sensitivity of the MET channel. Hair-bundle stiffness was normal at P20 but halved at P30, despite it having a normal staircase morphology and tip links. The reduction of MYO7A in the stereocilia (>87%) increased their vulnerability to sound-induced damage, with significantly more hearing loss and hair bundle deterioration than in control mice. RNA-sequencing identified a downregulation of several stereociliary genes in the Myo7a-deficient cochlea, indicating the presence of indirect compensatory mechanisms. This study reveals that mature hair cells seem to use a MYO7A-independent mechanism to maintain the resting Po of the MET channels. Instead, MYO7A is essential for maintaining the structural and functional integrity of the hair bundles.

Maternal aspartame exposure alters lung Th1/Th2 cytokine balance in offspring through nuclear factor-κB activation.

Epidemiological evidence suggests that maternal intake of nonnutritive sweeteners is positively associated with early childhood asthma incidence. We investigated the effects of maternal aspartame exposure during pregnancy and lactation on lung Th1/Th2 cytokine balance and intestinal microbiota in offspring and explored the mechanisms that mediate these effects. Pregnant BALB/c mice were randomly divided on gestational day 7 into two dietary intervention groups: control (drinking water only) and aspartame (drinking water+0.25g/L aspartame) groups. The dams nursed their offspring for 3weeks. On postnatal day 21, heart blood samples were collected, and immunoglobulin E levels were measured. Microorganisms from the lower gastrointestinal tract were sampled using a culture-independent approach. Lung tissues were harvested for biochemical analyses. Maternal aspartame exposure increased the body weight of the dams from gestational day 7 to postnatal day 21 and the body weight of the offspring from birth to postnatal day 21. Maternal aspartame exposure significantly increased the levels of Th2 cytokines (interleukin [IL]-4, IL-5, and IL-13) and IL-17 and immunoglobulin E but reduced that of a Th1 cytokine (interferon-γ) in the offspring's lung tissues. The altered Th1/Th2 balance was accompanied by increased lung nuclear factor-κB activation. The bacterial composition and alpha-diversity of the gut microbiota of the offspring did not differ significantly between the control and aspartame groups. Our findings suggest maternal aspartame exposure influences lung Th1/Th2 cytokine balance in offspring through nuclear factor-κB activation.

Therapeutic potential of targeting BMP/ALK pathway in pathological retinal neovascularization

Aims/Purpose: Pathological retinal neovascularization (PRNV) in ischemic retinopathies presents a significant clinical challenge. This study investigates the role of bone morphogenetic protein (BMP) signaling via ALK receptors in PRNV, with a focus on epigenetic modifications.Methods: The oxygen‐induced retinopathy (OIR) mouse model was utilized to investigate BMP signaling. Experimental groups included OIR mice treated with Noggin (a BMP inhibitor) or vehicle via ip from postnatal day 12‐16. Additional groups included a combined ALK2 and ALK3 endothelial conditional knockout mice (ALK2/3eKO), subjected to OIR. Capillary degeneration and neovascularization were assessed at postnatal day 17 in flat‐mount retinas using isolectin‐B4 staining. Immunostaining of retinal sections evaluated BMP2, BMP4, and ALK3 localization. In vitro experiments involved human retinal endothelial cells (HRECs) treated with BMP2 (50 ng/ml) or exposed to hypoxia (1% O2) for 48 hours. The impact of BMP2 on vascular endothelial growth factor (VEGF) was assessed through ELISA. MicroRNA (miRNA) expression was analyzed using the GeneChip miRNA 3.0 array. DNA methylation of HRECs was quantified using a colorimetric kit.Results: Immunostaining revealed an upregulation of BMP2, BMP4, and ALK3 expression in retinal vessels. Noggin‐treated and ALK2/3eKO OIR mice exhibited a significant reduction in capillary dropout and neovascularization (p &lt; 0.01). BMP2 treatment of HRECs elevated VEGF production. MiRNA array analysis indicated significant alterations by BMP2 (4%) and hypoxia (5%), including miRNAs linked to VEGF signaling and angiogenesis. Specifically, BMP2 downregulated miR‐4521, miR‐769‐3p, miR‐23b‐5p, miR‐3195, and miR‐6781‐5p, while upregulating miR‐126‐3p, miR‐921, miR‐7515, miR‐29c, and miR‐20b‐5p. Interestingly, BMP2 and hypoxia induced similar effects on certain miRNAs, such as miR‐769‐3p, miR‐23b, and miR‐20b. The DNA methylation assay demonstrated a statistically significant reduction induced by BMP2.Conclusions: BMP/ALK signaling plays a potential role in the pathogenesis of PRNV, possibly mediated through epigenetic modifications. Thereby, targeting BMP/ALK signaling holds a promise to mitigate PRNV in ischemic retinopathies

Effects of Cannabidiol Isolated or in Association With Risperidone in an Animal Model of Autism.

Autism spectrum disorder (ASD) is characterized by deficits in communication, social interaction, and repetitive and stereotyped behaviors, with no specific drug therapy available. Studies have found that cannabidiol (CBD) can improve hyperactive and cognitive symptoms in children with ASD. However, little is known about the effect of CBD in combination with other medications, such as risperidone (RISP). This study aimed to evaluate the behavioral and biochemical effects of CBD in animals using a valproic acid (VPA)-induced ASD animal model. VPA was administered in pregnant Wistar rats on Day 12.5 of gestation to induce the ASD model. From the 10th to the 16th postnatal day (PND), the neurodevelopment of the animals was assessed through eye-opening, olfactory discrimination, and negative geotaxis behavioral tests. From PNDs 9 to 54, the animals were weighed. They were treated for 21 days with CBD alone (100mg/kg, by gavage, twice a day) or in combination with RISP (0.1mg/kg, by gavage, once a day). At PND 55, the animals were evaluated in social interaction and locomotor activity experiments. Finally, after behavioral assessment, the animals were euthanized, the brain was isolated, and oxidative stress parameters were evaluated in the hippocampus and cortex posterior. Animals exposed to VPA showed neurodevelopmental delays in opening their eyes, difficulties in turning around their axis, and took longer time to find the original nest when compared to control animals. They also exhibited impaired sociability and reduced exploratory activity, which indicates model impairments. Interestingly, animals exposed to VPA treated with CBD+RISP significantly improved sociability parameters, whereas isolated CBD did not affect this parameter. In the biochemical analysis, a significant decrease in the hippocampal sulfhydryl content was noted in the CT+CBD group and an increase in the VPA+CBD group. In conclusion, these results suggest that CBD, in combination with RISP, may be an interesting pharmacological approach to reducing ASD-related symptoms. Summary: Besides the increased prevalence of ASD cases in recent years, there are no medications to improve the central symptoms of autism. Numerous studies discuss CBD as an important medication for improving ASD symptoms; however, it is not known how CBD interacts with commonly used drugs in ASD individuals, such as RISP. This study demonstrated that CBD therapy, only when combined with RISP, improved sociability in a VPA-induced ASD animal model.

Comparison of intravitreal PBS injection timepoints in the mouse oxygen‐induced retinopathy model

Aims/Purpose: Intravitreally (IVT) administered phosphate‐buffered saline (PBS) is known to reduce neovascularization in the mouse oxygen‐induced retinopathy (mOIR) model, and often used as a vehicle control in preclinical efficacy studies. Here, the aim was to compare the effects of PBS on neovascularization and revascularization when administered at different timepoints. VEGF‐inhibitor aflibercept (Eylea®) was used as a reference control.Methods: C57BL/6JRj male and female mice were exposed to 75 % oxygen from postnatal day 7 (P7) for 5 days. At P12 the mice were returned to normoxic conditions and IVT injected with PBS or aflibercept to the right eye at P12, P13, or P14 (n = 7‐9 eyes/group). Contralateral left eye was left untreated. Retinal flat mounts collected at P17 were stained with Isolectin B4, and microscopy images covering the whole retinal flat mount were analyzed for the size of neovascular (NV) and avascular (AVA) area using a proprietary AI‐based algorithm.Results: NV or AVA area did not differ between PBS and aflibercept at P12. Aflibercept reduced neovascularization by 83 % at P13 (Mann‐Whitney test, p &lt; 0.001) and by 65 % at P14 (unpaired t‐test, p &lt; 0.01) when compared to PBS, while AVA was similar between groups. When compared to untreated eyes, PBS significantly reduced neovascularization at P12, and the size of AVA area at P12 and P13 (Mann‐Whitney test, p ≤ 0.001).Conclusions: Our findings show significant anti‐angiogenic effect of PBS when injected at P12, suggesting that P12 is not an optimal timepoint for IVT treatment if PBS is used as a vehicle. PBS administered at P13 or P14 did not block neovascularization while it still was inhibited by aflibercept. Further studies are needed to explore if similar effect at P12 is seen with other vehicle or neutral antibody controls.

Maternal exposure to deltamethrin during pregnancy and lactation impairs hippocampal learning and memory function of male offspring by ferroptosis.

Deltamethrin (DM), a broad-spectrum insecticide, is widely used in the world. It can exert direct action on the central nervous system to produce neurotoxicity. Exposure to DM can lead to iron metabolism disorder, oxidative stress and learning and memory dysfunction. In our study, pregnant Wistar rats were randomly divided into four groups and gavaged at doses of 0, 1, 4 or 10 mg/kg/d DM from gestational day (GD) 0 to postnatal day (PND) 21. We used behavioral experiments and Nissl staining to observe the hippocampal development and learning and memory function of male offspring. In order to further confirm the regulation mechanisms of DM, we detected ferrous ion, oxidative stress, ferroptosis related proteins, phospholipase C (PL-C)/inositol triphosphate 3 receptor (IP3R) signaling pathway, intracellular Ca2+ and calcineurin (CaN) content in vivo. In vitro,we selected HT-22 cells to be exposed to DM under the intervention of ferrostatin-1 and pifithrin-α. Our results showed that maternal exposure to DM reduced T-maze correctness and the number of hippocampal neurons, and increased shuttle box passive avoidance rate. Moreover, maternal exposure to DM increased the expression of ferrous ion, malondialdehyde (MDA) and prostaglandin-endoperoxide synthase 2 (PTGS2) protein, and decreased the glutathione (GSH) level in the hippocampus, which was contributed to ferroptosis by p53-mediated solute carrier family 7 member 11 (SLC7A11)/glutathione peroxidase 4 (GPX4) axis in the male offspring. Furthermore, the ferroptosis caused by DM exposure could active PL-C/IP3R signaling pathway and increase the intracellular Ca2+ and CaN level, leading to an imbalance of calcium homeostasis in the hippocampus. Thus, maternal exposure to DM during pregnancy and lactation could impair hippocampal learning and memory function of male offspring by p53-mediated ferroptosis.

Early-life bisphenol A exposure causes detrimental age-related changes in anxiety, depression, learning, and memory in juvenile and adult male rats: Involvement of NMDAR/PSD-95–PTEN/AKT signaling pathway

Bisphenol A (BPA) is an endocrine disruptor monomer that is widely used in the manufacturing of epoxy resins and polycarbonate plastics. Several lines of evidence indicate the function of the pre- or perinatally PI3K/AKT signaling pathway in the development of psychiatric disorders. The present study aimed to evaluate for the first time the effect of modifying the NMDAR/PSD-95–PTEN/AKT signaling pathway on behavioral and synaptic plasticity of early-life BPA exposure and its long-lasting influence on juvenile and adulthood stages of development. We investigated the effects of oral BPA doses of 50 and 125mg/kg/day on the prefrontal cortex (PFC) and hippocampus of male Sprague Dawley rats from postnatal day (PND) 18–60 and PND 18–95, which correspond to juvenile and adolescent stages, respectively. Subsequently, we performed a series of rat behavioral tests, including the open field, elevated plus-maze, forced swimming, and Y-maze. Notably, neurotransmitter levels such as dopamine, serotonin, and gamma-aminobutyric acid, levels of postsynaptic density protein 95 and cAMP response element-binding protein, as well as mRNA levels of N-methyl-D-aspartate receptor subunits, fluctuated between reduction and elevation in the PFC and hippocampus. Furthermore, phosphatase and tensin (PTEN) mRNA and protein levels were upregulated in both brain areas, while PI3K, protein kinase B (AKT) and mammalian target of rapamycin (mTOR) mRNA and protein levels were decreased. Finally, our findings indicate that postnatal BPA exposure promotes long-term anxiety and depressive-like behaviors, as well as cognitive impairment, via modulation of the NMDAR/PSD-95–PTEN/AKT pathway. These findings could help to elucidate the potential developmental and neurobehavioral effects of early-life BPA exposure.

Early-life sodium restriction programs autonomic dysfunction and salt sensitivity in male C57BL/6J mice.

Preterm birth increases the risk of cardiometabolic disease in adulthood. Infants born during the second trimester of pregnancy, a critical period of hypothalamic development, are at risk of sodium (Na) depletion due to renal immaturity and large urine Na losses. We previously demonstrated in male mice that Na restriction during the equivalent mouse hypothalamic development period [postnatal day (PD)21-PD42] programs long-term changes in energy balance via increased thermogenic sympathetic nervous activity. We therefore hypothesized that early-life Na restriction programs changes in cardiovascular control via altered autonomic activity. C57BL/6J male mice were supplied a low (0.04%) Na or supplemented (0.30%) Na diet from PD21 to PD42, before return to standard (0.15%) Na diet. Hemodynamic and autonomic functions were assessed by radiotelemetry and acute administration of autonomic antagonists before and after all animals were switched to a high Na diet (HSD; 1% Na) at 12 wk of age. Mice were additionally treated with the angiotensin II type 1 receptor antagonist losartan for 2 wk. On standard diet, early-life Na restriction resulted in small but significantly different hemodynamic responses to autonomic blockers without any effect on systolic blood pressure (SBP) or heart rate. HSD increased SBP in 0.04% but not 0.30% Na mice, accompanied by increased cardiac sympathetic activity. Losartan had a greater BP-lowering effect in early-life Na-restricted mice. Our findings suggest that Na restriction during a critical hypothalamic developmental period programs long-term changes in the autonomic control of cardiovascular functions and may offer insight into the increased risk of cardiovascular disease in former preterm infants.NEW & NOTEWORTHY Mechanisms by which preterm birth increases the risk of adult-onset cardiometabolic diseases are not well understood. The renin-angiotensin system (RAS) has been implicated in the programming of adult disease, although contributors to RAS dysregulation remain to be identified. Findings from this study suggest that failure to maintain postnatal sodium homeostasis during a critical developmental window may contribute to RAS dysregulation and the risk of salt sensitivity of autonomic and cardiovascular function.

Suboptimal Refeeding Compensates Stunting in a Mouse Model of Juvenile Malnutrition.

Early postnatal life is a critical period of rapid growth in mammals, heavily reliant on adequate nutrition. Protein-energy malnutrition (PEM) during this window can lead to stunting and wasting, with lasting health consequences. This study developed a mouse model of juvenile PEM to assess the effects of refeeding with various diets and interventions on growth recovery, including probiotic supplementation and suboptimal refeeding diets. Outcomes included length and weight catch-up, organ weights, and glucose tolerance. Juvenile male and female C57Bl/6J mice (N = 8 to 11/group) were fed a low-protein diet (LPD, 5% kcal from protein) starting at postnatal day 14 (P14) to which the pups and dams had access. Following weaning, mice were refed an optimal diet (27% kcal from protein) at different times (P28 to P56). Male mice received additional interventions, including supplementation with Lactiplantibacillus plantarum WJL (LpWJL) during refeeding or refeeding with a Western diet (WD), 15.3% kcal from protein, or a modified Western diet (MWD) 7.5% kcal from protein. Statistical analyses used analysis of variance, analysis of covariance, and principal component analysis. Optimal refeeding restored growth in females (body weight in optimal-fed: 20.5 ± 0.3 g vs. 19.4 ± 0.6 g in P56-refed), but males showed persistent stunting (26.8 ± 0.7 g vs. 21.9 ± 0.9 g; P < 0.05). In males, LpWJL did not enhance growth recovery and exacerbated glucose intolerance in suboptimal refeeding groups. Males refed WD or MWD restored body length but showed impaired glucose metabolism, particularly in mice refed WD, with glycemia 30 min after glucose challenge reaching 20.4 ± 4.0 mM vs. 14.3 ± 3.0 mM in optimal-fed mice (P < 0.05). Sex-dependent differences in recovery from PEM were evident, with males showing incomplete growth recovery despite optimal refeeding. Suboptimal diets compensated for stunting but impaired glucose metabolism, and LpWJL did not improve growth outcomes.

Preventive effects of kefir on colon tumor development in Wistar rats: gut microbiota critical role.

To clarify the effects of kefir in critical periods of development in adult diseases, we study the effects of kefir intake during early life on gut microbiota and prevention of colorectal carcinogenesis in adulthood. Lactating Wistar rats were divided into three groups: control (C), kefir lactation (KL), and kefir puberty (KP) groups. The C and KP groups received 1 mL of water/day; KL dams received kefir milk daily (108 CFU/mL) during lactation. After weaning (postnatal day 21), KP pups received kefir treatment until 60 days. At 67 days old, colorectal carcinogenesis was induced through intraperitoneal injection of 1, 2-dimethylhydrazine. The gut microbiota composition were analyzed by 16S rRNA gene sequencing and DESeq2 (differential abundance method), revealing significant differences in bacterial abundances between the kefir consumption periods. Maternal kefir intake strong anticancer power, suppressed tumors in adult offspring and reduced the relative risk of offspring tumor development. The gut microbiota in cecal samples of the KL group was enriched with Lactobacillus, Romboutsia, and Blautia. In contrast, control animals were enriched with Acinetobacter. The administration of kefir during critical periods of development, with emphasis on lactation, affected the gut microbial community structure to promote host benefits. Pearson analysis indicated positive correlation between tumor number with IL-1 levels. Therefore, the probiotic fermented food intake in early life may be effective as chemopreventive potential against colon tumor development, especially in lactation period.

From Play Date to Stress Fate: Juvenile Social Play Rescues Stress-Induced Changes in Adult Social Behavior.

Long-term effects of social play on neural and behavioral development remain unclear. We investigated whether just 1 h of juvenile social play could rescue the effects of play deprivation on stress-related behavior and markers of neural plasticity. Syrian hamsters were reared from postnatal days 21-43 in three conditions: peer isolation, peer isolation with daily social play sessions (dyadic play), or group-housed with littermates. In adulthood, subjects were exposed to acute social defeat stress, and we examined changes in perineuronal net (PNN) expression surrounding parvalbumin (PV) neurons in the prelimbic (PL), infralimbic (IL), and basolateral amygdala (BLA). Peer deprivation led to exaggerated submissive and defensive behavior in a conditioned defeat test, but 1 h of dyadic play rescued the heightened conditioned defeat response in both males and females. In females, play deprivation reduced PNN/PV coexpression in the PL and IL compared to control groups with opportunities for social play. Males exposed to peer isolation showed elevated agonistic behavior when returned to their littermates compared to males exposed to 1-h play encounters. These findings indicate juvenile social play has long-lasting effects on PNN expression surrounding PV cells in the medial prefrontal cortex, which allows for the development of species' typical agonistic behavior and greater stress resistance in adulthood. The ability of just 1 h of social play to rescue the effects of peer isolation highlights the powerful role of social interactions in neural and behavioral development.