Embryo Brain Research Articles

Differential expression of small heat shock proteins in the brain of broiler embryo; the effects of embryonic thermal manipulation.

Broilers are more vulnerable to high temperatures than mammals due to the feather cover, lack of sweat glands, fast growth and intensive breeding in commercial systems. Thermal stresses affect the function of various organs and change the expression profiles of hundreds of genes in the different tissues of broilers. Thermal manipulation (TM) during embryogenesis can increase heat tolerance in growing broilers. Small heat shock proteins (SHSPs) are a group of HSPs which participate in many cellular functions like response to different stressors. However, their role in the thermotolerance has not been fully elucidated. Ninety fertilized eggs were randomly divided into three groups (30 eggs/group; 10 eggs/replicate). Normal control (NC) eggs were incubated at 37.5°C throughout the incubation period whereas heat stress (HS) and cold stress (CS) groups were kept at 41°C and 33°C from 15 to 17th day of incubation for 3h each day, respectively. On day 20, samples from the cerebrums were harvested for histopathology and mRNA expression analyses of HSPB1, HSPB5, HSPB8, and HSPB9. There were no significant differences in survivability, defected embryos, hatchability, and body weight among treatments. TM had no major deleterious effects on the cerebral tissue except for mild degeneration in the HS group. HSPB1, HSPB5, HSPB8, and HSPB9 were expressed in the presence and absence of TM. All SHSP genes tested were downregulated in response to TM except for HSPB9 which was upregulated in the HS group. The highest change in gene expression due to TM observed for HSPB1. This study presents a broader understanding of mechanisms underlying response to TM in broilers. The results suggest that HSPB1, HSPB5, HSPB8, and HSPB9 are involved in thermotolerance in broilers and SHSPs could be involved in the gene expression profiling of TM. It may propose the use of nutritional supplements in the poultry industry to modulate SHSPs.

Deficiency of MFSD7c results in microcephaly-associated vasculopathy in Fowler syndrome.

Several missense mutations in the orphan transporter FLVCR2 have been reported in Fowler syndrome. Affected subjects exhibit signs of severe neurological defects. We identified the mouse ortholog Mfsd7c as a gene expressed in the blood-brain barrier. Here, we report the characterizations of Mfsd7c-KO mice and compare these characterizations to phenotypic findings in humans with biallelic FLVCR2 mutations. Global KO of Mfsd7c in mice resulted in late-gestation lethality, likely due to CNS phenotypes. We found that the angiogenic growth of CNS blood vessels in the brain of Mfsd7c-KO embryos was inhibited in cortical ventricular zones and ganglionic eminences. Vascular tips were dilated and fused, resulting in glomeruloid vessels. Nonetheless, CNS blood vessels were intact, without hemorrhage. Both embryos and humans with biallelic FLVCR2 mutations exhibited reduced cerebral cortical layers, enlargement of the cerebral ventricles, and microcephaly. Transcriptomic analysis of Mfsd7cK-KO embryonic brains revealed upregulation of genes involved in glycolysis and angiogenesis. The Mfsd7c-KO brain exhibited hypoxia and neuronal cell death. Our results indicate that MFSD7c is required for the normal growth of CNS blood vessels and that ablation of this gene results in microcephaly-associated vasculopathy in mice and humans.

Propofol Attenuates Isoflurane-Induced Neurotoxicity and Cognitive Impairment in Fetal and Offspring Mice.

Anesthesia in pregnant rodents causes neurotoxicity in fetal and offspring rodents. However, the underlying mechanisms and targeted treatments remain largely to be determined. Isoflurane and propofol are among commonly used anesthetics. Thus, we set out to investigate whether propofol can mitigate the isoflurane-induced neurotoxicity in mice. Pregnant C57BL/6 mice at gestational day 15 (G15) were randomly assigned to 4 groups: control, isoflurane, propofol, and isoflurane plus propofol. Levels of interleukin (IL)-6 and poly-ADP ribose polymerase (PARP) fragment were measured in the brains of G15 embryos, and levels of postsynaptic density (PSD)-95 and synaptophysin were determined in the hippocampal tissues of postnatal day 31 (P31) offspring using Western blotting and immunohistochemical staining. Learning and memory functions in P31 offspring were determined using a Morris water maze test. Isoflurane anesthesia in pregnant mice at G15 significantly increased brain IL-6 (222.6% ± 36.45% vs 100.5% ± 3.43%, P < .0001) and PARP fragment (384.2% ± 50.87% vs 99.59% ± 3.25%, P < .0001) levels in fetal mice and reduced brain PSD-95 (30.76% ± 2.03% vs 100.8% ± 2.25%, P < .0001) and synaptophysin levels in cornu ammonis (CA) 1 region (57.08% ± 4.90% vs 100.6% ± 2.20%, P < .0001) and dentate gyrus (DG; 56.47% ± 3.76% vs 99.76% ± 1.09%, P < .0001) in P31 offspring. Isoflurane anesthesia also impaired cognitive function in offspring at P31. Propofol significantly mitigated isoflurane-induced increases in brain IL-6 (117.5% ± 10.37% vs 222.6% ± 36.45%, P < .0001) and PARP fragment (205.1% ± 35.99% vs 384.2% ± 50.87%, P < .0001) levels in fetal mice, as well as reductions in PSD-95 (49.79% ± 3.43% vs 30.76% ± 2.03%, P < .0001) and synaptophysin levels in CA1 region (85.57% ± 2.97% vs 57.08% ± 4.90%, P < .0001) and DG (85.05% ± 1.87% vs 56.47% ± 3.76%, P < .0001) in hippocampus of P31 offspring. Finally, propofol attenuated isoflurane-induced cognitive impairment in offspring. These findings suggest that gestational isoflurane exposure in mice induces neuroinflammation and apoptosis in embryos and causes cognitive impairment in offspring. Propofol can attenuate these isoflurane-induced detrimental effects.

Low-Dose Exposure of Silica Nanoparticles Induces Neurotoxicity via Neuroactive Ligand-Receptor Interaction Signaling Pathway in Zebrafish Embryos.

ObjectiveSilica nanoparticles (SiO2 NPs) have been extensively employed in biomedical field. SiO2 NPs are primarily designed to enter the circulatory system; however, little information is available on potential adverse effects of SiO2 NPs on the nervous system.MethodsThe neurotoxicity of SiO2 NPs at different concentrations (3, 6, 12 ng/nL) on zebrafish embryos was determined using immunofluorescence and microarray techniques, and subsequently confirmed by qRT-PCR.ResultsSiO2 NPs disrupt the axonal integrity and decrease the length of axons in Tg (NBT: EGFP) transgenic lines. The number of apoptotic cells in the brain and central nervous system of zebrafish embryos was increased in the presence of 12 ng/nL of SiO2 NPs, but the difference did not reach statistical significance. Screening for changes in the expression of genes involved in the neuroactive ligand–receptor interaction pathway was performed by microarray and confirmed by qRT-PCR. These analyses demonstrated that SiO2 NPs markedly downregulated genes associated with neural function (grm6a, drd1b, chrnb3b, adrb2a, grin2ab, npffr2.1, npy8br, gabrd, chrma3, gabrg3, gria3a, grm1a, adra2b, and glra3).ConclusionThe obtained results documented that SiO2 NPs can induce developmental neurotoxicity by affecting the neuroactive ligand–receptor interaction signaling pathway. This new evidence may help to clarify the mechanism of SiO2 NPs-mediated neurotoxicity.

Medications for pregnant women: A balancing act between the interests of the mother and of the fetus.

Drug entry into the adult brain is controlled by efflux mechanisms situated in various brain barrier interfaces. The effectiveness of these protective mechanisms in the embryo, fetus and newborn brain is less clear. The longstanding belief that "the" blood-brain barrier is absent or immature in the fetus and newborn has led to many misleading statements with potential clinical implications. Here we review the properties of brain barrier mechanisms in the context of drug entry into the developing brain and discuss the limited number of studies published on the subject. We noticed that most of available literature suffers from some experimental limitations, notably that drug levels in fetal blood and cerebrospinal fluid have not been measured. This means that the relative contribution to the overall brain protection provided by individual barriers such as the placenta (which contains similar efflux mechanisms) and the brain barriers cannot be separately ascertained. Finally, we propose that systematic studies in appropriate animal models of drug entry into the brain at different stages of development would provide a rational basis for use of medications in pregnancy and in newborns, especially prematurely born, where protection usually provided by the placenta is no longer present.

Effects of Low-Dose Gamma-Ray Radiation on Apoptosis and Development of Zebrafish Embryo Brain.

To investigate the effects of low-dose γ irradiation on apoptosis and development of the brain in zebrafish embryos, cumulative 15 mGy doses of γ rays from a 137Cs source were used to irradiate zebrafish embryos at 2 h post-fertilization (hpf) for 120 h. Apoptosis of the brain, brain morphological development, cell submicroscopic structure and mRNA expression were analyzed, respectively. Results indicate that after 15 mGy exposure, the apoptosis of zebrafish brain increased, vacuoles appeared in brain tissue, some organelles were damaged and vacuoles appeared locally in brain cells. The mRNA expression level of axin2 was significantly upregulated, and those of frizzled, β-catenin, camk2, TCF/ LEF and bcl9 were significantly downregulated in brain tissue. These genes are involved in the Wnt signaling pathway. The findings of this work suggest that low-dose radiation may influence the apoptosis and development of the brain in the zebrafish embryo by inhibiting the Wnt signaling pathway.

Perfluoroalkyl and polyfluroalkyl substances and maternal thyroid hormones in early pregnancy

BackgroundThe development of the embryo and fetal brain depends on maternal transfer of thyroid hormones (THs) in early pregnancy. Perfluoroalkyl and polyfluoralkyl substances (PFAS) may disrupt maternal TH homeostasis in pregnancy, but findings from epidemiologic studies were inconsistent. We aimed to assess this relationship in early pregnancy in a large prospective cohort study. MethodsA total of 1885 pregnant women enrolled in the Shanghai Birth Cohort were used. Ten PFAS, free thyroxine (FT4), free triiodothyronine (FT3), thyroid stimulating hormone (TSH) and thyroid peroxidase antibody (TPOAb) were measured in maternal blood collected prior to 16 weeks of gestation. Multiple linear regression accompanied by restricted cubic spline was used to examine the association and the exposure-response relationship between each PFAS and TH in separate models. Possible effect modification by TPOAb status was also investigated. ResultsPerfluorooctanoic acid [PFOA, β = 0.121, 95% confidence interval (CI): 0.015, 0.227] and perfluorohexane sulfonate (PFHxS, β = 0.123, 95% CI: 0.024, 0.222) were positively associated with FT4. Perfluorononanoic acid (PFNA, β = 0.179, 95% CI: 0.047, 0.311) and PFHxS (β = 0.197, 95% CI: 0.054, 0.339) were positively associated with FT3, while PFHxS was negatively associated with TSH (β = −0.115, 95%CI: 0.216, −0.014). TPOAb-positivity appeared to modify the associations between PFAS and THs. In TPOAb-positive women, several long-chain PFAS were positively associated with FT4 and/or FT3 and tended to be negatively associated with TSH. ConclusionsSeveral long-chain PFAS were associated with disrupted TH homeostasis in Chinese pregnant women, especially among TPOAb-positive women.

Orbencarb induces lethality and organ malformation in zebrafish embryos during development

Thiocarbamates are one of the components of pesticides that target weeds by inhibiting adenosine triphosphate (ATP) synthesis. Orbencarb, one of the isomeric thiocarbamates applied to wheat, maize, and soybean, has been found to have toxic effects on mammals and marine ecosystems. Although the toxicity ranges of orbencarb in different organisms are known, specific studies on the environmental contamination and harmful effects of orbencarb on non-target organisms are scarce. In this study, we observed that orbencarb induced embryotoxicity during zebrafish development as well as apoptosis and reactive oxygen species (ROS) production in the intestine. It was further observed that orbencarb decreased the viability of the embryos and simultaneously affected the heart rate and vessel formation. Orbencarb decreased the mRNA levels of ccnd1, ccne1, cdk2, and cdk6 and induced abnormal development of the eyes, brain, yolk sac, and spinal cord in zebrafish embryos. Orbencarb also hampered vasculogenesis in the zebrafish embryos by inhibiting the mRNA expression of flt1, flt4, kdr, and vegfc. Collectively, these results suggested that orbencarb is embryotoxic and disrupts the normal growth of zebrafish embryos by inducing the generation of ROS and hampering vasculogenesis.

Identification of Microglial Cell Molecular Markers During Chick Embryo Brain Development and Human Xenograft Tumor Formation

Glioblastoma (GBM) is the most aggressive and invasive human brain tumor, which despite advancement in surgery and immunology, only 10% of patients survive 18 months after diagnosis. The Galileo lab studies GBM, focusing on the role of the protein L1CAM on increasing the motility, proliferation, and invasiveness of GBM cells using in vitro cell tracking and a novel xenograft chick embryo brain tumor model. The work here focused on microglial cells, which are resident brain immune system cells that are not well understood. Studies in rodents and GBM patients showed that microglia play a critical role in promoting GBM growth via an activation of complex network of cytokines, chemokines and other metabolic factors that occur in the extracellular matrix. In the context of brain tumors, microglia promote neuroinflammation, which induces the BBB breakdown and inhibits antitumor immune responses. The first aim for my project was to find biomarkers that specifically identify microglial cells in normal chick embryo brain during development. The second aim was to use those markers in xenograft tumors in the chick embryo brain to look for any proinflammatory changes in microglial cells. Chick embryo brains were fixed, frozen, and cut into serial cryostat sections or fixed and vibratome sectioned, followed by immunofluorescent staining using antibodies or lectins that specifically identified microglial cells and endothelial cells in other model organisms. The optimal staining protocol required overnight primary antibody/lectin with 0.1% Triton X‐100 detergent and 5% normal goat serum in phosphate buffered saline. The antibodies and lectins investigated included Isolectin B4, Tomato (Lycopersicon esculentum) lectin, anti‐ferritin, anti‐laminin and CD45. Immunofluorescence analysis revealed CD45 to stain microglial cells with the most specificity. CD45 staining reveal microglial cell morphology to progressively change from a compact ameboid shape (E5) into ramified branched shape (E12 and E15). In addition to the increased quantity of ramified microglial cells in chick brain with xenograft human tumors, the microglia also appeared to be localized near endothelia. Further investigations are needed to verify the increased presence of reactive microglial cells and their interaction with tumor cells and angiogenesis.Support or Funding InformationThis work was supported by the Delaware INBRE program, with a grant from the National Institute of General Medical Sciences‐NIGMS (8 P20 GM103446‐16) from the National Institutes of Health, a grant to DSG from the National Cancer Institute, and a generous gift from Pamela S. Simpson ‘97 Translational Cancer Research Fund. I would like to thank Tyler Hellmig and Emily Kollenbroich for their guidance.

A study on MANOVA as an effective feature reduction technique in classification of childhood medulloblastoma and its subtypes

Childhood medulloblastoma (MB) is the most common embryo brain tumor and an area that needs utmost attention, as clinical diagnosis can be very difficult in case of infants and children. The rate of survival can increase with prompt diagnosis. Till date, there is no computer aided methodology for identification of childhood medulloblastoma and its subtypes. The diagnosis depends on qualitative visual inspection of the histological slides of the biopsy samples by clinical experts. We convert this qualitative judgment to quantitative features after digitization of the images. The feature set obtained from digital analysis from these biopsy tissues is very large and is computationally expensive. In this study, we examine whether the features are statistically significant for analysis towards classifying childhood MB from normal samples and its various subtypes, using MANOVA. Further, this technique is used as a feature reduction technique, which proves that it can be effectively used as such. Infact, the simplicity of the technique makes it a better choice when considering a sizeably high number of features.

Going Big: Million Atom Simulations of Ribosomes and Billion Atom Simulations of Chromatin

The rapid increase of computing power has enabled atomistic simulations of larger and larger systems. High performance computing (HPC) platforms with more than one million processor cores are not uncommon among the world's fastest supercomputers. Efficient utilization of these machines requires careful attention to parallel decomposition of the problem. Explicit solvent molecular dynamics (MD) simulations of large macromolecular complexes play an important role in integrating disparate forms of experimental data into a single coherent picture. These simulations help set the stage for reduced model and coarse-grained (CG) simulations capable of simulating large-scale conformational changes important for mechanistic understanding. We used explicit solvent MD simulations to identify the accommodation corridor in the ribosome, critical for tRNA selection during protein synthesis (Sanbonmatsu, et al., PNAS, 2005). Microsecond explicit solvent simulations of the ribosome (2.2 million atoms) also laid the foundations for our energy landscape calculations using all-atom structure-based simulations of spontaneous accommodation events (Whitford, et al., PLoS Comput. Biol., 2013; Whitford, et al., RNA, 2010). We are applying a similar strategy to chromatin architecture, which plays a key role in embryo development, brain function and cancer. As a first step, we have performed the first explicit solvent simulation of an entire gene locus (GATA4), consisting of 427 nucleosomes and over one billion atoms (the first published billion atom biomolecular simulation) (Jung, et al., J. Comp. Chem. 2019). Simulations used the GENESIS molecular dynamics code on the LANL Trinity supercomputer. The multi-disciplinary effort combined computer science, high performance computing, chip design, biophysics, structural biology, and cell biology, including researchers from RIKEN, LANL, NYU, Intel and Cray. Several performance optimizations for the KNL architecture enabled scaling to large numbers of cores.

Image-Based Structural Modeling of the Early-Stage Zebrafish Embryo Brain

During embryogenesis, spatiotemporal gene expression patterns direct the segmentation of primary brain compartments that are progressively refined into functional subunits of the adult brain. At the midbrain-hindbrain boundary (MHB), early errors in gene expression result in structural malformations that impair, by an unknown mechanism, the subsequent functional development of the tectum, cerebellum, and tegmentum which help to coordinate visuomotor responses. A quantitative model of the dynamic relationship between gene expression and structure formation would shed further insight on the role of different genes in this process. However, time-series analysis of the 3-dimensional multiphoton microscopy images of early-stage zebrafish embryo brain primordia poses a distinct challenge since the brain initially lacks recognizable landmarks to use as reference. Additional difficulty arises due to noise and pixel intensity variations within and across image data sets. To address these difficulties, we have developed a computational method that assigns simple geometric elements such as “beads” and “bonds” in a hierarchically refined structural model of the zebrafish brain for comparing different phenotypes and developmental time points. Our measurement highlight morphological differences between the wild type and zebrafish fgf8a(acerebellar) mutant that does not form MHB. Our approach is applicable to building quantitative surface models for images of other systems.

Inhibition of the electron transport chain in propofol induced neurotoxicity in zebrafish embryos

Fetal and neonatal exposure to propofol can lead to neuronal death and long-term neurobehavioral deficiencies in both rodents and nonhuman primates. Zebrafish embryo, which is fertilized ex-utero, has provided us a new model species to study the effects of general anesthetics on developing brain. Inhibited electron transport chain leads to mitochondrial dysfunction and insufficient energy production. The aim of this study was to dissect the role of electron transport chain in propofol-induced neurotoxicity. 6 h post fertilization (hpf) zebrafish embryos were exposed to control or 1, 2 or 4 μg/ml propofol until 48hpf. Acridine orange staining was used to assess cell apoptosis in the brain of zebrafish embryos. The activity of mitochondrial electron transport chain complex was assessed using colorimetric method. Expression of key subunit of cytochrome c oxidase was assessed by western blot and transcription level of cox4i1 was assessed by quantitative real time-PCR. The mitochondrial membrane potential and ATP content were assessed. Exposure to 1, 2 and 4 μg/ml propofol induced significant increases in cell apoptosis in the brain of zebrafish embryos in a dose-dependent manner and led to significant decreases in electron transport chain complex IV activity from (0.161 ± 0.023)μmol/mg/min in blank control-treated group to (0.096 ± 0.015)μmol/mg/min, (0.083 ± 0.013)μmol/mg/min and (0.045 ± 0.014)μmol/mg/min respectively, accompanied by decreased expression of key regulatory subunit of cytochrome c oxidase-subunit IV and decreased transcription level of cox4i1. Propofol exposure also decreased the mitochondrial membrane potential and ATP content. Our findings demonstrate that inhibition of the electron transport chain is involved in the mechanisms by which propofol induces neurotoxicity in the developing brain.

PERSPECTIVE STUDY OF THE AgNPs EFFECT ON THE MATERNAL AND EMBRYONIC DEVELOPMENT IN ALBINO RATS

This study was aimed to displayed effect of this nanoparticles on pregnant mother and embryos. All females administration of AgNPs suspension orally during the gestational period (for 21day) in two doses low 2mg and high dose 20 mg /Kg body weight and the control group received D.W only. The pregnant females (60 females) include the control group and the treated group was subdivided in to two groups, pre and post implantation and all the mothers weighted along the study. The embryos and their brains after retrieved weighted and the crow-rump length (CRL) measurement also. The results showed that the active form of Ag can be transport the placental barrier and blood brain barrier (BBB). This nanoparticles showed adverse effect and produced decreased in mothers weights in low dose 2mg/Kg/ B.Wt and higher dose 20mg/Kg/ B.Wt. Weights of embryos were lower clearly after exposure to AgNPs compare to control group. On the other hand, the weights of embryo's brain were decreased compare of control group in both doses. The CRL of embryos lowered after exposure to AgNPs in treatment groups when compare to control group.

Neurotrophic factors and inflammatory cytokines in the mother-placenta-fetus system in experimental hyperhomocysteinemia

An essential aspect of metabolic imbalance of L-homocysteine and its accumulation in blood (hyperhomocysteinemia) is its aggravating effect in pregnancy. However, little is known about the effects of maternal increased L-homocysteine levels on brain development of fetuses. In the development of the fetus, accompanied by changes in metabolism in the placenta, an important role belongs to neurotrophic factors and apoptosis. This study investigated the effects of chronic L-methionine administration on some parameters of inflammation and on neurotrophic factor levels in the brain of embryos, as well as in the placenta and serum of pregnant rats. The observed disturbances can be resulted from both a direct impact of L-homocysteine and its metabolites on the fetal CNS, and hyperhomocysteinemia-caused changes in normal state of the placenta.

Preventing Ethanol-Induced Brain and Eye Morphology Defects Using Optogenetics.

Background: Embryonic exposure to the teratogen ethanol leads to dysmorphias, including eye and brain morphology defects associated with fetal alcohol spectrum disorder (FASD). Exposure of Xenopus laevis embryos to ethanol leads to similar developmental defects, including brain and eye dysmorphism, confirming our work and the work of others showing Xenopus as a useful system for studies of the brain and eye birth defects associated with FASD. Several targets of ethanol action have been hypothesized, one being regulation of Kir2.1 potassium channel. Endogenous ion fluxes and membrane voltage variation (bioelectric signals) have been shown to be powerful regulators of embryonic cell behaviors that are required for correct brain and eye morphology. Disruptions to these voltage patterns lead to spatially correlated disruptions in gene expression patterns and corresponding morphology. Materials and Methods: Here, we use controlled membrane voltage modulation to determine when and where voltage modulation is sufficient to rescue ethanol-induced brain and eye defects in Xenopus embryos. Results: We found (1) that modulating membrane voltage using light activation of the channelrhodopsin-2 variant D156A rescues ethanol exposed embryos, resulting in normal brain and eye morphologies; (2) hyperpolarization is required for the full duration of ethanol exposure; (3) hyperpolarization of only superficial ectoderm is sufficient for this effect; and(4) the rescue effect acts at a distance. Conclusions: These results, particularly the last, raise the exciting possibility of using bioelectric modulation to treat ethanol-induced brain and eye birth defects, possibly with extant ion channel drugs already prescribed to pregnant women. This may prove to be a simple and cost-effective strategy for reducing the impact of FASD.

Roles of ErbB3-binding protein 1 (EBP1) in embryonic development and gene-silencing control

ErbB3-binding protein 1 (EBP1) is implicated in diverse cellular functions, including apoptosis, cell proliferation, and differentiation. Here, by generating genetic inactivation of Ebp1 mice, we identified the physiological roles of EBP1 in vivo. Loss of Ebp1 in mice caused aberrant organogenesis, including brain malformation, and death between E13.5 and 15.5 owing to severe hemorrhages, with massive apoptosis and cessation of cell proliferation. Specific ablation of Ebp1 in neurons caused structural abnormalities of brain with neuron loss in [Nestin-Cre; Ebp1flox/flox ] mice. Notably, global methylation increased with high levels of the gene-silencing unit Suv39H1/DNMT1 in Ebp1-deficient mice. EBP1 repressed the transcription of Dnmt1 by binding to its promoter region and interrupted DNMT1-mediated methylation at its target gene, Survivin promoter region. Reinstatement of EBP1 into embryo brain relived gene repression and rescued neuron death. Our findings uncover an essential role for EBP1 in embryonic development and implicate its function in transcriptional regulation.

Intra-cerebral implantation of a variety of collagenous scaffolds with nervous embryonic cells.

Collagenous scaffolds provide good conditions for embryonic nerve cell growth. The aim of the current study was to assess the brains reaction to the implantation of 3D sponge-shaped scaffolds. These scaffolds consisted of collagen (Col) and Col with chondroitin sulphate, which is modified by carbodiimide, or Col crosslinked with dialdehyde cellulose. The current study also evaluated the expression of integrins α2 and β1 in embryonic nerve cells. Embryonic nerve cells were isolated from the brains of rat embryos. Acellular scaffolds, or scaffolds populated with embryonic nerve cells, were implanted into the rats brain. The fibers of all the implanted scaffolds remained intact and served as a template for cell infiltration. The implants induced minimal to moderate inflammatory responses and minimal glial scar formations. Immunohistochemical studies did not indicate any microtubule-associated protein 2 or glial fibrillary acidic protein-positive cells inside the scaffolds. Acellular and cell-populated scaffolds yielded similar responses in the brain. The expression of integrin α2 and β1 was observed in embryonic nervous cells. TC-I15, the integrin α2β1 inhibitor, was not demonstrated to modify cell entrapment within the collagenous scaffolds. All applied scaffolds were well tolerated by the tissue and were indicated to support blood vessel formation. Therefore, all tested biomaterials are recommended for further studies. Additional chemical modifications of the material are suggested to protect the seeded cells from apoptosis after implantation into the brain.

The protective effect of Zataria Multiflora on the embryotoxicity induced by bisphenol A in the brain of chicken embryos

Bisphenol A (BPA), is one of the main industrial chemicals synthesized for various purposes. In the present study, the brain tissue of chicken embryos was used to evaluate the embryotoxic effects of BPA and also the preventive effects of Zataria multiflora. To that end, fertile eggs were categorized into four groups (n=10). The eggs air sacs of the experimental groups were injected BPA (200 ppm) after four days.. The Zataria multiflora (100 and 200 µg/egg) was administered into chick embryos 6 hours prior to administration of BPA. The control group simply was treated with olive oil. The eggs were incubated at 37°C and a humidity of 63%. After 20 days, the embryos were beheaded and the brains were gathered for biochemical measurements. The findings indicated that Zataria multiflora (200 µg/egg) significantly reversed the increased levels of MDA (p&lt;0.05) and protein (p&lt;0.001) in the brain of BPA-exposed group and also the decreased levels of total antioxidant and GSH as well as the CAT and SOD activities in the brain of BPA-exposed group. Zataria multiflora reversed the toxic effects of BPA on the embryonic development stages of the brain via modulating oxidative stress.

Immortalization of a cell line with neural stem cell characteristics derived from mouse embryo brain.

Neural stem cells (NSC) have been extensively used as a tool to investigate the mechanisms responsible for neural repair, and they have been also considered as the source for a series of promising replacement therapies in various neurodegenerative diseases. However, their use is limited by their relative rarity and anatomical localization, and also because, the methods for isolation and characterization are usually time consuming and have some technical limitations. In this study, we describe a resource and method for obtaining immortalized cells with NSC characteristics obtained from mouse brain embryo. Because these cells can be maintained indefinitely in culture, they may constitute a permanent source of NSC that can be used for research studies on neural development and regeneration.