B cell-helper neutrophils stimulate the diversification and production of immunoglobulin in the marginal zone of the spleen.

Neutrophils use immunoglobulins to clear antigen, but their role in immunoglobulin production is unknown. Here we identified neutrophils around the marginal zone (MZ) of the spleen, a B cell area specialized in T cell-independent immunoglobulin responses to circulating antigen. Neutrophils colonized peri-MZ areas after postnatal mucosal colonization by microbes and enhanced their B cell-helper function after receiving reprogramming signals, including interleukin 10 (IL-10), from splenic sinusoidal endothelial cells. Splenic neutrophils induced immunoglobulin class switching, somatic hypermutation and antibody production by activating MZ B cells through a mechanism that involved the cytokines BAFF, APRIL and IL-21. Neutropenic patients had fewer and hypomutated MZ B cells and a lower abundance of preimmune immunoglobulins to T cell-independent antigens, which indicates that neutrophils generate an innate layer of antimicrobial immunoglobulin defense by interacting with MZ B cells.

Decreased cell proliferation and higher oxidative stress in fibroblasts from Down Syndrome fetuses. Preliminary study.

Down Syndrome is the most common chromosomal disease and is also known for its decreased incidence of solid tumors and its progeroid phenotype. Cellular and systemic oxidative stress has been considered as one of the Down Syndrome phenotype causes. We correlated, in a preliminary study, the fibroblast proliferation rate and different cell proliferation key regulators, like Rcan1 and the telomere length from Down Syndrome fetuses, with their oxidative stress profile and the Ribonucleic acid and protein expression of the main antioxidant enzymes together with their activity. Increased oxidized glutathione/glutathione ratio and high peroxide production were found in our cell model. These results correlated with a distorted antioxidant shield. The messenger RNA (SOD1) and protein levels of copper/zinc superoxide dismutase were increased together with a decreased mRNA expression and protein levels of glutathione peroxidase (GPx). As a consequence the [Cu/ZnSOD/(catalase+GPx)] activity ratio increases which explains the oxidative stress generated in the cell model. In addition, the expression of thioredoxin 1 and glutaredoxin 1 is decreased. The results obtained show a decreased antioxidant phenotype that correlates with increased levels of Regulator of calcineurin 1 and attrition of telomeres, both related to oxidative stress and cell cycle impairment. Our preliminary results may explain the proneness to a progeroid phenotype.

A cluster of protein kinases and phosphatases modulated in fetal Down syndrome (trisomy 21) brain.

Down syndrome (DS; trisomy 21) is the most frequent cause of mental retardation with major cognitive and behavioral deficits. Although a series of aberrant biochemical pathways has been reported, work on signaling proteins is limited. It was, therefore, the aim of the study to test a selection of protein kinases and phosphatases known to be essential for memory and learning mechanisms in fetal DS brain. 12 frontal cortices from DS brain were compared to 12 frontal cortices from controls obtained at legal abortions. Proteins were extracted from brains and western blotting with specific antibodies was carried out. Primary results were used for networking (IntAct Molecular Interaction Database) and individual predicted pathway components were subsequently quantified by western blotting. Levels of calcium-calmodulin kinase II alpha, transforming growth factor beta-activated kinase 1 as well as phosphatase and tensin homolog (PTEN) were reduced in cortex of DS subjects and network generation pointed to interaction between PTEN and the dendritic spine protein drebrin that was subsequently determined and reduced levels were observed. The findings of reduced levels of cognitive-function-related protein kinases and the phosphatase may be relevant for interpretation of previous work and may be useful for the design of future studies on signaling in DS brain. Moreover, decreased drebrin levels may point to dendritic spine abnormalities.

Telomeric repeat-containing RNA and telomerase in human fetal oocytes.

STUDY QUESTION: What is the distribution of telomeric repeat-containing RNA (TERRA) and of telomerase in human fetal oocytes? SUMMARY ANSWER: TERRA forms discrete foci at telomeres of human fetal oocytes and it co-localizes with both the shelterin component telomeric repeat-binding factor 2 (TRF2) and the catalytic subunit of human telomerase at the telomeres of meiotic chromosomes. WHAT IS KNOWN ALREADY: TERRA is a structural element of the telomeric chromatin that has been described in somatic cells of many different eukaryote species. The telomerase enzyme is inactive in adult somatic cells but is active in germ cells, stem cells and in the majority of tumors; however, its distribution in oocytes is still unknown. STUDY DESIGN, SIZE, DURATION: For this study, ovarian samples from four euploid fetuses of 22 gestational weeks were used. These samples were obtained with the consent of the parents and of the Ethics Committee of Hospital de la Vall d'Hebron. PARTICIPANTS/MATERIALS, SETTING, METHODS: We analyzed the distribution of TERRA and telomerase in cells derived from human fetal ovaries. The co-localization of TERRA, telomerase and telomeres was performed by optimizing a combination of immunofluorescence (IF) and RNA-fluorescent in situ hybridization (RNA-FISH) techniques. The synaptonemal complex protein 3 (SYCP3), TRF2 and protein component of telomerase [telomerase reverse transcriptase (TERT)] were detected by IF, whereas TERRA was revealed by RNA-FISH using a (CCCTAA)(3) oligonucleotide. SYCP3 signals allowed us to identify oocytes that had entered meiosis and classify them into the different stages of prophase I, whereas TRF2 indicated the telomeric regions of chromosomes. MAIN RESULTS AND THE ROLE OF CHANCE: We show for the first time the presence of TERRA and the intracellular distribution of telomerase in human fetal ovarian cells. TERRA is present, forming discrete foci, in 75% of the ovarian tissue cells and most of TERRA molecules (≈ 83%) are at telomeres (TRF2 co-localization). TERRA levels are higher in oocytes than in ovarian tissue cells (P = 0.00), and do not change along the progression of the prophase I stage (P = 0.37). TERRA is present on ≈ 23% of the telomeres in all cell types derived from human fetal ovaries. Moreover, ≈ 22% of TERRA foci co-localize with the protein component of telomerase (TERT). LIMITATIONS, REASONS FOR CAUTION: We present a descriptive/qualitative study of TERRA in human fetal ovarian tissue. Given the difficult access and manipulation of fetal samples, the number of fetal ovaries used in this study was limited. WIDER IMPLICATIONS OF THE FINDINGS: This is the first report on TERRA expression in oocytes from human fetal ovaries. The presence of TERRA at the telomeres of oocytes from the leptotene to pachytene stages and its co-localization with the telomerase protein component suggests that this RNA might participate in the maintenance of the telomere structure, at least through the processes that take place during the female meiotic prophase I. Since telomeres in oocytes have been mainly studied regarding the bouquet structure, our results introduce a new viewpoint of the telomeric structure during meiosis.

Remodeling of the fetal collecting duct epithelium.

Congenital urinary tract obstruction induces changes to the renal collecting duct epithelium, including alteration and depletion of intercalated cells. To study the effects of obstruction on the ontogeny of intercalated cell development, we examined normal and obstructed human fetal and postnatal kidneys. In the normal human fetal kidney, intercalated cells originated in the medullary collecting duct at 8 weeks gestation and remained most abundant in the inner medulla throughout gestation. In the cortex, intercalated cells were rare at 18 and 26 weeks gestation and observed at low abundance at 36 weeks gestation. Although early intercalated cells exhibit an immature phenotype, Type A intercalated cells predominated in the inner and outer medullae at 26 and 36 weeks gestation with other intercalated cell subtypes observed rarely. Postnatally, the collecting duct epithelium underwent a remodeling whereby intercalated cells become abundant in the cortex yet absent from the inner medulla. In 18-week obstructed kidneys with mild to moderate injury, the intercalated cells became more abundant and differentiated than the equivalent age-matched normal kidney. In contrast, more severely injured ducts of the late obstructed kidney exhibited a significant reduction in intercalated cells. These studies characterize the normal ontogeny of human intercalated cell development and suggest that obstruction induces premature remodeling and differentiation of the fetal collecting duct epithelium.

Thoracic findings of systemic diseases at high-resolution CT in children.

Pulmonary involvement in systemic diseases is common, but the radiographic appearance of early-stage pulmonary changes is often subtle. Computed tomography (CT) has higher sensitivity and specificity than radiography, and high-resolution CT is the method of choice for accurate assessment of diffuse parenchymal lung disease. Even with reductions in the peak voltage and tube charge to minimize the exposure of pediatric patients to radiation, CT performed with a meticulous acquisition technique can provide detailed information. In some cases, high-resolution CT may depict clinically silent lung lesions. The information provided by CT is invaluable for planning therapy in pediatric patients with pulmonary involvement in connective tissue disease (eg, juvenile rheumatoid arthritis, dermatomyositis, systemic sclerosis, systemic lupus erythematosus, or mixed connective tissue disease), vasculitis, a primary or acquired immune deficiency disorder, immotile cilia syndrome, cystic fibrosis, or Langerhans cell histiocytosis.

Engineering DYRK1A overdosage yields Down syndrome-characteristic cortical splicing aberrations.

Down syndrome (DS) associates with impaired brain functions, but the underlying mechanism(s) are yet unclear. The "gene dosage" hypothesis predicts that in DS, overexpression of a single gene can impair multiple brain functions through a signal amplification effect due to impaired regulatory mechanism(s). Here, we report findings attributing to impairments in the splicing process such a regulatory role. We have used DS fetal brain samples in search for initial evidence and employed engineered mice with MMU16 partial trisomy (Ts65Dn) or direct excess of the splicing-associated nuclear kinase Dyrk1A, overdosed in DS for further analyses. We present specific albeit modest changes in the DS brain's splicing machinery with subsequently amplified effects in target transcripts; and we demonstrate that engineered excess of Dyrk1A can largely recapitulate these changes. Specifically, in both the fetal DS brains and the Dyrk1A overdose models, we found ample modestly modified splicing-associated transcripts which apparently induced secondary enhancement in exon inclusion of key synaptic transcripts. Thus, DS-reduced levels of the dominant-negative TRKBT1 transcript, but not other TRKB mRNA transcripts, were accompanied by corresponding decreases in BDNF. In addition, the DS brains and Dyrk1A overdosage models showed selective changes in the transcripts composition of neuroligin mRNAs as well as reductions in the "synaptic" acetylcholinesterase variant AChE-S mRNA and corresponding increases in the stress-inducible AChE-R mRNA variant, yielding key synaptic proteins with unusual features. In cotransfected cells, Dyrk1A overdosage caused parallel changes in the splicing pattern of an AChE mini-gene, suggesting that Dyrk1A overdosage is both essential and sufficient to induce the observed change in the composition of AChE mRNA variants. Furthermore, the Dyrk1A overdosage animal models showed pronounced changes in the structure of neuronal nuclear speckles, where splicing events take place and in SR proteins phosphorylation known to be required for the splicing process. Together, our findings demonstrate DS-like brain splicing machinery malfunctioning in Dyrk1A overexpressing mice. Since individual splicing choices may alter cell fate determination, axon guidance, and synaptogenesis, these findings suggest the retrieval of balanced splicing as a goal for DS therapeutic manipulations early in DS development.

Mechanism of the Dual Activities of Human CYP17A1 and Binding to Anti-Prostate Cancer Drug Abiraterone Revealed by a Novel V366M Mutation Causing 17,20 Lyase Deficiency.

The CYP17A1 gene regulates sex steroid biosynthesis in humans through 17α-hydroxylase/17,20 lyase activities and is a target of anti-prostate cancer drug abiraterone. In a 46, XY patient with female external genitalia, together with a loss of function mutation S441P, we identified a novel missense mutation V366M at the catalytic center of CYP17A1 which preferentially impaired 17,20 lyase activity. Kinetic experiments with bacterially expressed proteins revealed that V366M mutant enzyme can bind and metabolize pregnenolone to 17OH-pregnenolone, but 17OH-pregnenolone binding and conversion to dehydroepiandrosterone (DHEA) was impaired, explaining the patient’s steroid profile. Abiraterone could not bind and inhibit the 17α-hydroxylase activity of the CYP17A1-V366M mutant. Molecular dynamics (MD) simulations showed that V366M creates a “one-way valve” and suggests a mechanism for dual activities of human CYP17A1 where, after the conversion of pregnenolone to 17OH-pregnenolone, the product exits the active site and re-enters for conversion to dehydroepiandrosterone. The V366M mutant also explained the effectiveness of the anti-prostate cancer drug abiraterone as a potent inhibitor of CYP17A1 by binding tightly at the active site in the WT enzyme. The V366M is the first human mutation to be described at the active site of CYP17A1 that causes isolated 17,20 lyase deficiency. Knowledge about the specificity of CYP17A1 activities is of importance for the development of treatments for polycystic ovary syndrome and inhibitors for prostate cancer therapy.

Gray-scale and color Doppler sonography of scrotal disorders in children: an update.

Ultrasonography (US) is well suited to the study of pathologic conditions of the scrotum in children. US provides excellent anatomic detail; when color Doppler and power Doppler imaging are added, testicular perfusion can be assessed. Gray-scale, color Doppler, and power Doppler US were used to study a spectrum of scrotal disorders in 750 boys aged 1 day to 17 years. The entities studied included processus vaginalis-related disorders (cryptorchidism, inguinal-scrotal hernia, and hydrocele); varicocele; acute scrotum (epididymo-orchitis, torsion of the testicular appendages, and testicular torsion); scrotal tumors; testicular microlithiasis; scrotal trauma; and systemic diseases with scrotal involvement. When combined with the results of clinical and physical examination, the information obtained with US is sufficient to enable diagnosis in most cases of scrotal disease. Moreover, color Doppler imaging is essential for differentiation between processes such as epididymo-orchitis or torsion of the testicular appendages and testicular torsion, which have similar clinical manifestations (pain, swelling, and redness) but are managed differently.

DNA methylation abnormalities in congenital heart disease.

Congenital heart defects represent the most common malformation at birth, occurring also in ∼50% of individuals with Down syndrome. Congenital heart defects are thought to have multifactorial etiology, but the main causes are largely unknown. We have explored the global methylation profile of fetal heart DNA in comparison to blood DNA from control subjects: an absolute correlation with the type of tissue was detected. Pathway analysis revealed a significant enrichment of differential methylation at genes related to muscle contraction and cardiomyopathies in the developing heart DNA. We have also searched for abnormal methylation profiles on developing heart-tissue DNA of syndromic and non-syndromic congenital heart defects. On average, 3 regions with aberrant methylation were detected per sample and 18 regions were found differentially methylated between groups. Several epimutations were detected in candidate genes involved in growth regulation, apoptosis and folate pathway. A likely pathogenic hypermethylation of several intragenic sites at the MSX1 gene, involved in outflow tract morphogenesis, was found in a fetus with isolated heart malformation. In addition, hypermethylation of the GATA4 gene was present in fetuses with Down syndrome with or without congenital heart defects, as well as in fetuses with isolated heart malformations. Expression deregulation of the abnormally methylated genes was detected. Our data indicate that epigenetic alterations of relevant genes are present in developing heart DNA in fetuses with both isolated and syndromic heart malformations. These epimutations likely contribute to the pathogenesis of the malformation by cis-acting effects on gene expression.

Increased expression of estrogen receptor beta in pachytene spermatocytes after short-term methoxyacetic acid administration.

Degeneration of primary spermatocytes by apoptosis occurs during normal spermatogenesis, as well as in several pathological conditions, including exposure to specific testicular toxicants. The mechanisms that regulate the death and survival of primary spermatocytes, however, are still not well understood. The recent localization of estrogen receptor beta (ERbeta) and P450 aromatase in pachytene spermatocytes suggests a role for estrogens in this step of spermatogenesis. Using a well-known model of pachytene spermatocyte apoptosis in adult rats consisting of the administration of methoxyacetic acid (MAA), we investigated the participation of ERbeta during the initial phase of apoptosis, prior to germ cell loss. Adult rats were treated with a single intraperitoneal dose of MAA, and DNA laddering analysis confirmed apoptotic cell death in the testis. In enriched germ cell fractions and testis from MAA-treated animals, ERbeta mRNA increased significantly at 3 and 6 hours, respectively. Next, stage-specific induction of ERbeta mRNA was demonstrated by use of laser capture microdissection of seminiferous tubules in combination with semiquantitative reverse transcription-polymerase chain reaction. The ERbeta protein also increased significantly after 6 hours and was mainly immunolocalized in the cytoplasm of pachytene spermatocytes of afflicted tubules. The cytoplasmic localization was confirmed by Western blot analysis of isolated cytoplasmic and nuclear fractions of testicular extracts. Finally, the MAA activation of ERbeta was tested in vitro in HepG2 cells cotransfected with ERbeta and a reporter construct that contained a consensus estrogen responsive element. Addition of MAA at similar doses used in vivo elicited a similar estrogenic activation as did estradiol at 1 nmol/L concentration. The present results raise the possibility that cytoplasmic ERbeta participates in the apoptotic process of pachytene spermatocytes induced by MAA. Whether MAA interacts with ERbeta in the cytoplasm of primary spermatocytes, preventing the progression of the first meiotic division, however, remains to be determined.

Single intracoronary injection of encapsulated antagomir-92a promotes angiogenesis and prevents adverse infarct remodeling.

BACKGROUND: Small and large preclinical animal models have shown that antagomir-92a-based therapy reduces early postischemic loss of function, but its effect on postinfarction remodeling is not known. In addition, the reported remote miR-92a inhibition in noncardiac organs prevents the translation of nonvectorized miR-targeted therapy to the clinical setting. We investigated whether a single intracoronary administration of antagomir-92a encapsulated in microspheres could prevent deleterious remodeling of myocardium 1 month after acute myocardial infarction AUTHOR: Should "acute" be added before "myocardial infarction" (since abbreviation is AMI)? Also check at first mention in main text (AMI) without adverse effects. METHODS AND RESULTS: In a percutaneous pig model of reperfused AMI, a single intracoronary administration of antagomir-92a encapsulated in specific microspheres (9 µm poly-d,-lactide-co-glycolide [PLGA]) inhibited miR-92a in a local, selective, and sustained manner (n=3 pigs euthanized 1, 3, and 10 days after treatment; 8×, 2×, and 5×-fold inhibition at 1, 3, and 10 days). Downregulation of miR-92a resulted in significant vessel growth (n=27 adult minipigs randomly allocated to blind receive encapsulated antagomir-92a, encapsulated placebo, or saline [n=8, 9, 9]; P=0.001), reduced regional wall-motion dysfunction (P=0.03), and prevented adverse remodeling in the infarct area 1 month after injury (P=0.03). Intracoronary injection of microspheres had no significant adverse effect in downstream myocardium in healthy pigs (n=2), and fluorescein isothiocyanate albumin-PLGA microspheres were not found in myocardium outside the left anterior descending coronary artery territory (n=4) or in other organs (n=2). CONCLUSIONS: Early single intracoronary administration of encapsulated antagomir-92a in an adult pig model of reperfused AMI prevents left ventricular remodeling with no local or distant adverse effects, emerging as a promising therapeutic approach to translate to patients who suffer a large AMI.

Caveolin-1 is down-regulated in alveolar rhabdomyosarcomas and negatively regulates tumor growth.

Rhabdomyosarcoma is the most common soft tissue sarcoma of childhood and adolescence. Despite advances in therapy, patients with histological variant of rhabdomyosarcoma known as alveolar rhabdomyosarcoma (ARMS) have a 5-year survival of less than 30%. Caveolin-1 (CAV1), encoding the structural component of cellular caveolae, is a suggested tumor suppressor gene involved in cell signaling. In the present study we report that compared to other forms of rhabdomyosarcoma (RMS) CAV1 expression is either undetectable or very low in ARMS cell lines and tumor samples. DNA methylation analysis of the promoter region and azacytidine-induced re-expression suggest the involvement of epigenetic mechanisms in the silencing of CAV1. Reintroduction of CAV1 in three of these cell lines impairs their clonogenic capacity and promotes features of muscular differentiation. In vitro, CAV1-expressing cells show high expression of Caveolin-3 (CAV3), a muscular differentiation marker. Blockade of MAPK signaling is also observed. In vivo, CAV1-expressing xenografts show growth delay, features of muscular differentiation and increased cell death. In summary, our results suggest that CAV1 could function as a potent tumor suppressor in ARMS tumors. Inhibition of CAV1 function therefore, could contribute to aberrant cell proliferation, leading to ARMS development.

Reduction in neural injury with earlier delivery in a mouse model of congenital myelomeningocele: laboratory investigation.

OBJECT: The authors undertook this study to assess the effect of preterm delivery with respect to neural protection in a congenital myelomeningocele (MMC) mouse model. METHODS: After confirmation of pregnancy in 15 female mice, a congenital MMC model was produced by administration of retinoic acid on the 7th day of gestation. The pregnant mice underwent cesarean sections on Days 15 (n = 5, Group E15), 17 (n = 5, Group E17), and 19 (n = 5, Group E19). Histological analyses were conducted on the lumbar defect and on the craniocervical junction in all fetuses with MMC. RESULTS: Fetuses in Group E19 showed the most significant injury to neural tissue of the spinal cord at the MMC area followed by those in Group E17, with Group E15 being the least affected. All groups exhibited a degree of Chiari malformation; Group E19 was the most affected, followed by Group E17, and Group E15 was the least affected. CONCLUSIONS: Development of both Chiari malformation and exposed spinal cord injury are progressive during gestation. Preterm delivery in this mouse model of congenital MMC may minimize the degree of injury to the spinal cord neural tissue and the degree of Chiari malformation.

Contribution of rare copy number variants to isolated human malformations.

BACKGROUND: Congenital malformations are present in approximately 2-3% of liveborn babies and 20% of stillborn fetuses. The mechanisms underlying the majority of sporadic and isolated congenital malformations are poorly understood, although it is hypothesized that the accumulation of rare genetic, genomic and epigenetic variants converge to deregulate developmental networks. METHODOLOGY/PRINCIPAL FINDINGS: We selected samples from 95 fetuses with congenital malformations not ascribed to a specific syndrome (68 with isolated malformations, 27 with multiple malformations). Karyotyping and Multiplex Ligation-dependent Probe Amplification (MLPA) discarded recurrent genomic and cytogenetic rearrangements. DNA extracted from the affected tissue (46%) or from lung or liver (54%) was analyzed by molecular karyotyping. Validations and inheritance were obtained by MLPA. We identified 22 rare copy number variants (CNV) [>100 kb, either absent (n = 7) or very uncommon (n = 15, <1/2,000) in the control population] in 20/95 fetuses with congenital malformations (21%), including 11 deletions and 11 duplications. One of the 9 tested rearrangements was de novo while the remaining were inherited from a healthy parent. The highest frequency was observed in fetuses with heart hypoplasia (8/17, 62.5%), with two events previously related with the phenotype. Double events hitting candidate genes were detected in two samples with brain malformations. Globally, the burden of deletions was significantly higher in fetuses with malformations compared to controls. CONCLUSIONS/SIGNIFICANCE: Our data reveal a significant contribution of rare deletion-type CNV, mostly inherited but also de novo, to human congenital malformations, especially heart hypoplasia, and reinforce the hypothesis of a multifactorial etiology in most cases.

Association of ventricular noncompaction and histiocytoid cardiomyopathy: case report and review of the literature.

We report an association between ventricular noncompaction and histiocytoid cardiomyopathy. Both entities are rare, and only 2 cases of their association have been reported previously in the medical literature. Ventricular noncompaction is believed to be caused by an arrest of the normal endomyocardial development, resulting in a thin and compacted epicardial layer and a thickened noncompacted endocardial layer. Histiocytoid cardiomyopathy is a rare arrhythmogenic disorder characterized by aggregates of oncocytic cells involving predominantly the subendocardium. These cells are thought to be abnormal Purkinje cells. In our case, the histiocytoid cells showed strong cytoplasmic expression for the skeletal muscle transcription factor MyoD1, which could be attributed to cross reactivity with an undetermined cytoplasmic antigen.

A gel-based proteomic method reveals several protein pathway abnormalities in fetal Down syndrome brain.

A large series of protein pathway components have been shown to be dysregulated in Down syndrome (DS) brain. No information about pathomechanisms linked to the trisomic state can be obtained from adult DS brain, however, as neurodegeneration occurs from the fourth decade. The aim of the study was to search for protein dysregulation in fetal DS brain before neurodegenerative changes are observed. Proteins were extracted from fetal DS and control frontal cortex, run on 2-DE, followed by quantification of protein spots with subsequent nano-ESI-LC-MS/MS analysis using an ion trap. Aberrant expression of proteins tropomodulin-2, tubulin alpha 1A chain, and alpha-internexin may indicate disturbed synaptic plasticity; fatty acid binding protein 7 suggests impaired maintenance of neuroepithelial cells; and creatine kinase B may reflect defective energy metabolism. RNA binding protein 4B derangement may represent impaired splicing, altered retrotransposon gag domain-containing protein 1 levels may be pointing to altered retrotransposition, and level changes of the potassium-chloride transporter solute carrier family 12 member 7 may lead to impaired ion fluxes with electrophysiological consequences. Taken together, aberrant protein levels from several pathways in fetal DS are challenging as well as fertilizing the area of research and providing the basis for additional neurochemical and functional studies.

Effects of birth advancement in Chiari malformation in a surgical myelomeningocele model in rabbits.

BACKGROUND/PURPOSE: In myelomeningocele (MMC), Chiari II malformation progresses during gestation because of the continuous loss of cerebrospinal fluid at the site of the defect. Our purpose was to assess the impact of birth advancement (BA) and prenatal corticosteroid treatment (PCT) on Chiari malformation in a surgical MMC model in rabbits. METHODS: A surgical MMC-like defect was created in 75 fetal rabbits. Animals were distributed into 4 groups depending on the treatment received: not treated and those undergoing BA + PCT, BA, or PCT. The degree of Chiari malformation in newborn rabbits was defined as the percentage of downward protrusion of the hindbrain between the end of the occipital bone and the beginning of the first vertebral arch. RESULTS: The degree of hindbrain herniation was 80% (8.15) in the not treated group, 36.8% (10.57) in BA + PCT, 41.8% (8.27) in BA, and 44.4% (8.32) in PCT. The BA + PCT, BA, and PCT groups showed less severe hindbrain herniation than not treated animals (mean decrease, 39.86%; SD, 10.57; P = .000). There were no significant differences between the BA + PCT, BA, and PCT groups (P = .311). CONCLUSIONS: Birth advancement and prenatal administration of corticosteroids decrease the severity of the hindbrain herniation component of Chiari II malformation in surgical MMC in fetal rabbits.

The calcium-sensing receptor and parathyroid hormone-related protein are expressed in differentiated, favorable neuroblastic tumors.

BACKGROUND: Differentiated histopathology is a favorable prognostic factor in neuroblastic tumors, and molecular pathways underlying neuroblastoma differentiation can be modulated pharmacologically. The calcium-sensing receptor (CaR) and parathyroid hormone-related protein (PTHrP) regulate differentiation processes in some cellular contexts. CaR is up-regulated when neural stem cells are specified to the oligodendrocyte lineage and regulates PTHrP production in astrocytes. The objective of the current study was to assess whether CaR and PTHrP participate in neuroblastoma differentiation pathways. METHODS: CaR and PTHrP messenger RNA (mRNA) and protein expression were analyzed in neuroblastic tumors, and correlation with prognostic factors was assessed. CaR and PTHrP expression levels were analyzed in neuroblastoma cell lines treated with all-trans-retinoic acid or 5-bromo-2'-deoxyuridine (BrdU). RESULTS: CaR expression was correlated with favorable histology, age at diagnosis <1 year, low clinical stage, and low clinical risk. CaR was absent in undifferentiated neuroblasts and was expressed in differentiating neuroblasts. CaR and PTHrP were highly expressed in ganglion and in Schwann-like cells. PTHrP mRNA levels were higher in ganglioneuroblastomas and ganglioneuromas than in neuroblastomas (P < .0001). Both genes were up-regulated in neuroblastomas with treatment-induced maturation features. CaR, but not PTHrP, was up-regulated at early phases of in vitro neuronal differentiation induction. Substrate-adherent, non-neuronal cell lines displayed the highest PTHrP levels among the neuroblastoma cell lines examined. The up-regulation of PTHrP and of 2 glial differentiation markers was observed in 2 cell lines that were treated with BrdU, whereas CaR was induced in only 1 cell line. CONCLUSIONS: CaR and PTHrP were expressed in differentiated, favorable neuroblastic tumors, and both genes were up-regulated by inducing differentiation.