Search Results (23)

DNA methylation holds promise for the early detection of tissue damage, making it crucial for identifying polycyclic aromatic hydrocarbon (PAH)-associated epigenetic biomarkers in childhood asthma. Sulforaphane (SFN), as a potential epigenetic modulator, can alleviate the adverse effects of environmental pollutants. This study quantified serum PAHs in 370 children via gas chromatography–mass spectrometry, assessed the methylation of target genes using bisulfite sequencing PCR (BSP), and performed mediation analysis to estimate the mediating effects of methylation levels between PAHs and childhood asthma. Murine models exposed to PAHs prenatally or postnatally, with offspring challenged with ovalbumin (OVA), were analyzed for lung DNA methylation. In vitro, HBE cells and HBSMCs treated with benzo(a)pyrene (BaP) and/or SFN were tested for inflammatory cytokines, methylation-related enzymes, and matrix metallopeptidase 9 (MMP9) modifications. The results showed total PAHs were associated with childhood asthma, with mediating effects of long interspersed nuclear element-1 (LINE-1) methylation. Prenatal PAH exposure enriched differentially methylated genes in the extracellular matrix (ECM)-receptor interaction pathway, while postnatal exposure enriched those in purine metabolism, and postnatal exposure also elevated Mmp9 expression via hypomethylation. BaP increased the expression of interferon gamma (IFN-γ), interleukin-4 (IL-4), interleukin-17A (IL-17A), transforming growth factor beta 1 (TGF-β), and ten-eleven translocation methylcytosine dioxygenases (TETs), and it upregulated MMP9 via enhancer hypomethylation and H3K27ac enrichment, while SFN reversed these effects by downregulating histone methyltransferase (HMT), leading to reduced H3K4me1 and subsequent H3K27ac depletion, thus suppressing MMP9 transcription. This study demonstrates that DNA methylation mediates PAH–childhood asthma associations, with distinct patterns in different exposure windows; MMP9 could serve as a crucial target for epigenetic modification during lung inflammation induced by PAH exposure, and SFN reverses PAH-induced epigenetic changes, aiding prevention strategies. Full article

Background/Objectives: Protocadherin 7 (Pcdh7) belongs to the protocadherin family, the largest subgroup of cell adhesion molecules. Members of this family are highly expressed in the brain, where they serve fundamental roles in many neurodevelopmental processes, including axon guidance, dendrite self-avoidance, and synaptic formation. PCDH7 has been strongly associated with epilepsy in multiple genome-wide association studies (GWAS), as well as with schizophrenia, PTSD, and childhood aggression. Despite these associations, the specific contributions of PCDH7 to epileptogenesis and brain development remain largely unexplored. Most of the existing literature on PCDH7 focuses on its function during cancer progression, with only one study suggesting that PCDH7 regulates dendritic spine morphology and synaptic function via interaction with GluN1. Methods: Here, we generate, validate, and characterize a murine null Pcdh7 allele in which a large deletion was introduced by CRISPR. Results: Analysis of embryonic, postnatal, and adult brain datasets confirmed PCDH7 widespread expression. Pcdh7^+/− and Pcdh7^−/− mice present no gross morphological defects and normal cortical layer formation. However, a seizure susceptibility assay revealed increased latencies in Pcdh7^+/− mice, but not in Pcdh7^+/+ and Pcdh7^−/− mice, potentially explaining the association of PCDH7 with epilepsy. Conclusions: This initial characterization of Pcdh7 null mice suggests that, despite its widespread expression in the CNS and involvement in human epilepsy, PCDH7 is not essential for murine brain development and thus is not a suitable animal model for understanding PCDH7 disruption in humans. However, further detailed analysis of this mouse model may reveal circuit or synaptic abnormalities in Pcdh7 null brains. Full article

Myo/Nog cells play a pivotal role in ocular development and demonstrate a rapid response to stress and injury. This study investigates their behavior and distribution in a murine model of retinitis pigmentosa, specifically in C3H/HeJ mice, which exhibit photoreceptor degeneration due to a homozygous mutation in the Pde6brd1 gene. Retinal samples from C3H/HeJ and C57BL/6J mice were analyzed at postnatal weeks 2.5 to 6 using hematoxylin and eosin staining, immunofluorescence for brain-specific angiogenesis inhibitor 1 (BAI1) expressed in Myo/Nog cells, and TUNEL labeling for apoptotic cell detection. The results demonstrated a progressive thinning of the outer nuclear layer (ONL) in C3H mice, accompanied by a significant increase in Myo/Nog cell numbers. In normal retinas, Myo/Nog cells were primarily located in the inner nuclear and outer plexiform layers. However, in C3H/HeJ mice, they accumulated in the ONL near apoptotic photoreceptors and within the choroid. Notably, in these degenerative regions, Myo/Nog cells exhibited features of phagocytosis, suggesting a role in apoptotic cell clearance. Additionally, parallels between Myo/Nog cell responses in retinitis pigmentosa and models of oxygen-induced retinopathy, ocular hypertension, and light damage suggest that these cells may be leveraged for therapeutic purposes. Full article

Background: The Zika virus (ZIKV) is an arbovirus linked to “Congenital Zika Syndrome” and a range of neurodevelopmental disorders (NDDs), with microcephaly as the most severe manifestation. Milder NDDs, such as autism spectrum disorders and delays in neuropsychomotor and language development, often go unnoticed in neonates, resulting in long-term social and academic difficulties. Murine models of ZIKV infection can be used to mimic part of the spectrum of motor and cognitive deficits observed in humans. These can be evaluated through behavioral tests, enabling comparison with gene expression profiles and aiding in the characterization of ZIKV-induced NDDs. Objectives: This study aimed to identify genes associated with behavioral changes following a subtle ZIKV infection in juvenile BALB/c mice. Methods: Neonatal mice were subcutaneously inoculated with ZIKV (MH544701.2) on postnatal day 1 (DPN) at a dose of 6.8 × 10³ PFU. Viral presence in the cerebellum and cortex was quantified at 10- and 30-days post-infection (DPI) using RT-qPCR. Neurobehavioral deficits were assessed at 30 DPI through T-maze, rotarod, and open field tests. Next-Generation Sequencing (NGS) was performed to identify differentially expressed genes (DEGs), which were analyzed through Gene Ontology (GO) and KEGG enrichment. Gene interaction networks were then constructed to explore gene interactions in the most enriched biological categories. Results: A ZIKV infection model was successfully established, enabling brain infection while allowing survival beyond 30 DPI. The infection induced mild cognitive behavioral changes, though motor and motivational functions remained unaffected. These cognitive changes were linked to the functional repression of synaptic vesicles and alterations in neuronal structure, suggesting potential disruptions in neuronal plasticity. Conclusions: Moderate ZIKV infection with circulating strains from the 2016 epidemic may cause dysregulation of genes related to immune response, alterations in cytoskeletal organization, and modifications in cellular transport mediated by vesicles. Despite viral control, neurocognitive effects persisted, including memory deficits and anxiety-like behaviors, highlighting the long-term neurological consequences of ZIKV infection in models that show no apparent malformations. Full article

Human milk (HM) is rich in bioactive factors promoting postnatal small intestinal development and maturation of the microbiome. HM is also protective against necrotizing enterocolitis (NEC), a devastating inflammatory condition predominantly affecting preterm infants. The HM glycosaminoglycan, hyaluronan (HA), is present at high levels in colostrum and early milk. Our group has demonstrated that HA with a molecular weight of 35 kDa (HA35) promotes maturation of the murine neonatal intestine and protects against two distinct models of NEC. However, the molecular mechanisms underpinning HA35-induced changes in the developing ileum are unclear. CD-1 mouse pups were treated with HA35 or vehicle control daily, from P7 to P14, and we used network and functional analyses of bulk RNA-seq ileal transcriptomes to further characterize molecular mechanisms through which HA35 likely influences intestinal maturation. HA35-treated pups separated well by principal component analysis, and cell deconvolution revealed increases in stromal, Paneth, and mature enterocyte and progenitor cells in HA35-treated pups. Gene set enrichment and pathway analyses demonstrated upregulation in key processes related to antioxidant and growth pathways, such as nuclear factor erythroid 2-related factor-mediated oxidative stress response, hypoxia inducible factor-1 alpha, mechanistic target of rapamycin, and downregulation of apoptotic signaling. Collectively, pro-growth and differentiation signals induced by HA35 may present novel mechanisms by which this HM bioactive factor may protect against NEC. Full article

Background: An increased incidence of adult-onset heart failure is seen in individuals born preterm or affected by fetal growth restriction. An adverse maternal environment is associated with both preterm birth and poor fetal development, and postnatal oxygen therapy is frequently required to sustain oxygenation of vulnerable tissues due to lung immaturity. Methods: Studies using our murine model of maternal inflammation (LPS) and neonatal hyperoxia exposure (O₂) observed pathological changes in cardiac structural proteins and functional analysis with sex dependent differences in pathologies at 10 months of age. Using our previous model, the current investigations tested the hypothesis that early-life perturbations in cardiac structural proteins might predict adult cardiac dysfunction in a sex dependent manner. Results: LPS-exposed females had lower αMHC mRNA and protein at P0 and P7 relative to the saline-exposed females, but these changes did not persist. Male mice exposed to LPS/O₂ had normal expression of αMHC mRNA and protein compared to saline/room air controls though P56, when they dramatically increased. Correlative changes were observed in left ventricular function with a more severe phenotype in the males indicating sex-based differences in cardiac adaptation. Conclusions: Our findings demonstrate that early changes in contractile proteins temporally correlate with deficits in cardiac contractility, with a more severe phenotype in males. Our data suggest that similar findings in humans may predict risk for disease in growth-restricted infants. Full article

Background: Exposure to hyperoxia is an important factor in the development of bronchopulmonary dysplasia (BPD) in preterm newborns. MicroRNAs (miRs) have been implicated in the pathogenesis of BPD and provide a potential therapeutic target. Methods: This study was conducted utilizing a postnatal animal model of experimental hyperoxia-induced murine BPD to investigate the expression and function of miR-195 as well as its molecular signaling targets within developing mouse lung tissue. Results: miR-195 expression levels increased in response to hyperoxia in male and female lungs, with the most significant elevation occurring in 40% O₂ (mild) and 60% O₂ (moderate) BPD. The inhibition of miR-195 improved pulmonary morphology in the hyperoxia-induced BPD model in male and female mice with females showing more resistance to injury and better recovery of alveolar chord length, septal thickness, and radial alveolar count. Additionally, we reveal miR-195-dependent signaling pathways involved in BPD and identify PH domain leucine-rich repeat protein phosphatase 2 (PHLPP2) as a novel specific target protein of miR-195. Conclusions: Our data demonstrate that high levels of miR-195 in neonatal lungs cause the exacerbation of hyperoxia-induced experimental BPD while its inhibition results in amelioration. This finding suggests a therapeutic potential of miR-195 inhibition in preventing BPD. Full article

Phosphatase and tensin homolog (Pten) is a key regulator of cell proliferation and a potential target to stimulate postnatal enteric neuro- and/or gliogenesis. To investigate this, we generated two tamoxifen-inducible Cre recombinase murine models in which Pten was conditionally ablated, (1) in glia (Plp1-expressing cells) and (2) in neurons (Calb2-expressing cells). Tamoxifen-treated adult (7–12 weeks of age; n = 4–15) mice were given DSS to induce colitis, EdU to monitor cell proliferation, and were evaluated at two timepoints: (1) early (3–4 days post-DSS) and (2) late (3–4 weeks post-DSS). We investigated gut motility and evaluated the enteric nervous system. Pten inhibition in Plp1-expressing cells elicited gliogenesis at baseline and post-DSS (early and late) in the colon, and neurogenesis post-DSS late in the proximal colon. They also exhibited an increased frequency of colonic migrating motor complexes (CMMC) and slower whole gut transit times. Pten inhibition in Calb2-expressing cells did not induce enteric neuro- or gliogenesis, and no alterations were detected in CMMC or whole gut transit times when compared to the control at baseline or post-DSS (early and late). Our results merit further research into Pten modulation where increased glia and/or slower intestinal transit times are desired (e.g., short-bowel syndrome and rapid-transit disorders). Full article

Attention deficit-hyperactivity disorder (ADHD) is a neurodevelopmental disorder with high incidence in children and adolescents characterized by motor hyperactivity, impulsivity, and inattention. Magnetic resonance imaging (MRI) has revealed that neuroanatomical abnormalities such as the volume reduction in the neocortex and hippocampus are shared by several neuropsychiatric diseases such as schizophrenia, autism spectrum disorder and ADHD. Furthermore, the abnormal development and postnatal pruning of dendritic spines of neocortical neurons in schizophrenia, autism spectrum disorder and intellectual disability are well documented. Dendritic spines are dynamic structures exhibiting Hebbian and homeostatic plasticity that triggers intracellular cascades involving glutamate receptors, calcium influx and remodeling of the F-actin network. The long-term potentiation (LTP)-induced insertion of postsynaptic glutamate receptors is associated with the enlargement of spine heads and long-term depression (LTD) with spine shrinkage. Using a murine model of ADHD, a delay in dendritic spines’ maturation in CA1 hippocampal neurons correlated with impaired working memory and hippocampal LTP has recently reported. The aim of this review is to summarize recent evidence that has emerged from studies focused on the neuroanatomical and genetic features found in ADHD patients as well as reports from animal models describing the molecular structure and remodeling of dendritic spines. Full article

Krabbe disease (KD) is a progressive and devasting neurological disorder that leads to the toxic accumulation of psychosine in the white matter of the central nervous system (CNS). The condition is inherited via biallelic, loss-of-function mutations in the galactosylceramidase (GALC) gene. To rescue GALC gene function in the CNS of the twitcher mouse model of KD, an adeno-associated virus serotype 1 vector expressing murine GALC under control of a chicken β-actin promoter (AAV1-GALC) was administered to newborn mice by unilateral intracerebroventricular injection. AAV1-GALC treatment significantly improved body weight gain and survival of the twitcher mice (n = 8) when compared with untreated controls (n = 5). The maximum weight gain after postnatal day 10 was significantly increased from 81% to 217%. The median lifespan was extended from 43 days to 78 days (range: 74–88 days) in the AAV1-GALC-treated group. Widespread expression of GALC protein and alleviation of KD neuropathology were detected in the CNS of the treated mice when examined at the moribund stage. Functionally, elevated levels of psychosine were completely normalized in the forebrain region of the treated mice. In the posterior region, which includes the mid- and the hindbrain, psychosine was reduced by an average of 77% (range: 53–93%) compared to the controls. Notably, psychosine levels in this region were inversely correlated with body weight and lifespan of AAV1-GALC-treated mice, suggesting that the degree of viral transduction of posterior brain regions following ventricular injection determined treatment efficacy on growth and survivability, respectively. Overall, our results suggest that viral vector delivery via the cerebroventricular system can partially correct psychosine accumulation in brain that leads to slower disease progression in KD. Full article

Inflammation causes bronchopulmonary dysplasia (BPD), a common lung disease of preterm infants. One reason this disease lacks specific therapies is the paucity of information on the mechanisms regulating inflammation in developing lungs. We address this gap by characterizing the lymphatic phenotype in an experimental BPD model because lymphatics are major regulators of immune homeostasis. We hypothesized that hyperoxia (HO), a major risk factor for experimental and human BPD, disrupts lymphatic endothelial homeostasis using neonatal mice and human dermal lymphatic endothelial cells (HDLECs). Exposure to 70% O₂ for 24–72 h decreased the expression of prospero homeobox 1 (Prox1) and vascular endothelial growth factor c (Vegf-c) and increased the expression of heme oxygenase 1 and NAD(P)H dehydrogenase [quinone]1 in HDLECs, and reduced their tubule formation ability. Next, we determined Prox1 and Vegf-c mRNA levels on postnatal days (P) 7 and 14 in neonatal murine lungs. The mRNA levels of these genes increased from P7 to P14, and 70% O₂ exposure for 14 d (HO) attenuated this physiological increase in pro-lymphatic factors. Further, HO exposure decreased VEGFR3⁺ and podoplanin⁺ lymphatic vessel density and lymphatic function in neonatal murine lungs. Collectively, our results validate the hypothesis that HO disrupts lymphatic endothelial homeostasis. Full article

Mutations in cartilage oligomeric matrix protein (COMP) causes protein misfolding and accumulation in chondrocytes that compromises skeletal growth and joint health in pseudoachondroplasia (PSACH), a severe dwarfing condition. Using the MT-COMP mice, a murine model of PSACH, we showed that pathological autophagy blockage was key to the intracellular accumulation of mutant-COMP. Autophagy is blocked by elevated mTORC1 signaling, preventing ER clearance and ensuring chondrocyte death. We demonstrated that resveratrol reduces the growth plate pathology by relieving the autophagy blockage allowing the ER clearance of mutant-COMP, which partially rescues limb length. To expand potential PSACH treatment options, CurQ+, a uniquely absorbable formulation of curcumin, was tested in MT-COMP mice at doses of 82.3 (1X) and 164.6 mg/kg (2X). CurQ+ treatment of MT-COMP mice from 1 to 4 weeks postnatally decreased mutant COMP intracellular retention, inflammation, restoring both autophagy and chondrocyte proliferation. CurQ+ reduction of cellular stress in growth plate chondrocytes dramatically reduced chondrocyte death, normalized femur length at 2X 164.6 mg/kg and recovered 60% of lost limb growth at 1X 82.3 mg/kg. These results indicate that CurQ+ is a potential therapy for COMPopathy-associated lost limb growth, joint degeneration, and other conditions involving persistent inflammation, oxidative stress, and a block of autophagy. Full article

Schizophrenia (SZ) is a heterogeneous mental disorder, affecting ~1% of the worldwide population. One of the main pathophysiological theories of SZ is the imbalance of excitatory glutamatergic pyramidal neurons and inhibitory GABAergic interneurons, involving N-methyl-D-aspartate receptors (NMDAr). This may lead to local glutamate storms coupled with excessive dendritic pruning and subsequent cellular stress, including nitrosative stress, during a critical period of neurodevelopment, such as adolescence. Nitrosative stress is mediated by nitric oxide (NO), which is released by NO synthases (NOS) and has emerged as a key signaling molecule implicated in SZ. Regarding glutamatergic models of SZ, the administration of NMDAr antagonists has been found to increase NOS levels in the prefrontal cortex (PFC) and ventral hippocampus (HPC). We hypothesized that suboptimal NOS function in adolescence could be a target for early treatments, including clozapine (CLZ) and the novel metabotropic glutamate receptor modulator JNJ-46356479 (JNJ). We analyzed the protein levels of NOS isoforms in adult PFC and HPC of a postnatal ketamine induced murine model of SZ receiving CLZ or JNJ during adolescence by western blot. Endothelial NOS and neuronal NOS increased under ketamine administration in PFC and decreased in CLZ or JNJ treatments. The same trends were found in the HPC in neuronal NOS. In contrast, inducible NOS was increased under JNJ treatment with respect to ketamine induction in the HPC, and the same trends were found in the PFC. Taken together, our findings suggest a misbalance of the NOS system following NMDAr antagonist administration, which was then modulated under early CLZ and JNJ treatments. Full article

Previously we utilized a murine model to demonstrate that Ogt deletion in pancreatic progenitors (OgtKO^Panc) causes pancreatic hypoplasia, partly mediated by a reduction in the Pdx1-expressing pancreatic progenitor pool. Here, we continue to explore the role of Ogt in pancreas development by deletion of Ogt in the endocrine progenitors (OgtKO^Endo). At birth OgtKO^Endo, were normoglycemic and had comparable pancreas weight and α-cell, and β-cell mass to littermate controls. At postnatal day 23, OgtKO^Endo displayed wide ranging but generally elevated blood glucose levels, with histological analyses showing aberrant islet architecture with α-cells invading the islet core. By postnatal day 60, these mice were overtly diabetic and showed significant loss of both α-cell and β-cell mass. Together, these results highlight the indispensable role of Ogt in maintenance of β-cell mass and glucose homeostasis. Full article

Epidemiology and animal studies suggest that a paternal history of toxicant exposure contributes to the developmental origins of health and disease. Using a mouse model, our laboratory previously reported that a paternal history of in utero exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) increased his offspring’s risk of developing necrotizing enterocolitis (NEC). Additionally, our group and others have found that formula supplementation also increases the risk of NEC in both humans and mice. Our murine studies revealed that intervening with a paternal fish oil diet preconception eliminated the TCDD-associated outcomes that are risk factors for NEC (e.g., intrauterine growth restriction, delayed postnatal growth, and preterm birth). However, the efficacy of a paternal fish oil diet in eliminating the risk of disease development in his offspring was not investigated. Herein, reproductive-age male mice exposed to TCDD in utero were weaned to a standard or fish oil diet for one full cycle of spermatogenesis, then mated to age-matched unexposed females. Their offspring were randomized to a strict maternal milk diet or a supplemental formula diet from postnatal days 7–10. Offspring colon contents and intestines were collected to determine the onset of gut dysbiosis and NEC. We found that a paternal fish oil diet preconception reduced his offspring’s risk of toxicant-driven NEC, which was associated with a decrease in the relative abundance of the Firmicutes phylum, but an increase in the relative abundance of the Negativicutes class. Full article