Analysis of CNTNAP1 gene variants in a Chinese pedigree affected with lethal congenital contracture syndrome type 7 / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a couple who had developed polyhydramnios during three pregnancies and given birth to two liveborns featuring limb contracture, dyspnea and neonatal death.@*METHODS@#Whole-exome sequencing (WES) was carried out on fetal tissue and peripheral blood samples from the couple. Suspected variants were verified by Sanger sequencing.@*RESULTS@#The fetus was found to harbor homozygous nonsense c.3718C>T (p.Arg1240Ter) variants of the CNTNAP1 gene, which were respectively inherited from its mother and father. The variant was unreported previously. According to the guidelines of the American College of Medical Genetics and Genomics, the variant was predicted to be pathogenic (PVS1+PM2+PP4).@*CONCLUSION@#The novel homozygous nonsense variants of the CNTNAP1 gene probably underlay the lethal congenital contracture syndrome type 7 (LCCS7) in this pedigree. Above finding has enabled genetic counseling and prenatal diagnosis for the family.

Analysis of NRXN1 gene deletion in an autistic patient / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a patient with autism.@*METHODS@#High-throughput sequencing was carried out to detect copy number variations in the patient.@*RESULTS@#DNA sequencing found that the patient has carried a 0.11 Mb deletion in distal 2p16.3 spanning from genomic position 50 820 001 to 50 922 000, which resulted removal of exon 6 and part of intron 7 of the NRXN1 gene. The same deletion was not found his parents and brother.@*CONCLUSION@#Partial deletion of the NRXN1 gene may underlie the disease in this patient.

Neuroligins Differentially Mediate Subtype-Specific Synapse Formation in Pyramidal Neurons and Interneurons / 神经科学通报·英文版

Neuroligins (NLs) are postsynaptic cell-adhesion proteins that play important roles in synapse formation and the excitatory-inhibitory balance. They have been associated with autism in both human genetic and animal model studies, and affect synaptic connections and synaptic plasticity in several brain regions. Yet current research mainly focuses on pyramidal neurons, while the function of NLs in interneurons remains to be understood. To explore the functional difference among NLs in the subtype-specific synapse formation of both pyramidal neurons and interneurons, we performed viral-mediated shRNA knockdown of NLs in cultured rat cortical neurons and examined the synapses in the two major types of neurons. Our results showed that in both types of neurons, NL1 and NL3 were involved in excitatory synapse formation, and NL2 in GABAergic synapse formation. Interestingly, NL1 affected GABAergic synapse formation more specifically than NL3, and NL2 affected excitatory synapse density preferentially in pyramidal neurons. In summary, our results demonstrated that different NLs play distinct roles in regulating the development and balance of excitatory and inhibitory synapses in pyramidal neurons and interneurons.

Genome-Wide Screening of Aberrant Methylation Loci for Nonsyndromic Cleft Lip / 中华医学杂志(英文版)

Background@#The pathogenicity of cleft lip (CL) is pretty complicated since it is influenced by the interaction of environment and genetic factors. The purpose of this study was to conduct a genome-wide screening of aberrant methylation loci in partial lesion tissues of patients with nonsyndromic CL (NSCL) and preliminarily validate candidate dysmethylated genes associated with NSCL.@*Methods@#Fifteen healthy and sixteen NSCL fetal lip tissue samples were collected. The Infinium HumanMethylation450 BeadChip was used to screen aberrant methylation loci in three NSCL and three healthy lip tissues. The differential methylation sites and functions of the annotated genes between NSCL and healthy lip tissues were analyzed using minfi package of R software, cluster analysis, Gene Ontology (GO) annotation, and metabolic pathway annotation. Gene expression was assessed in nine differentially methylated genes by real-time polymerase chain reaction (PCR). The transcriptions mRNA levels of three out of nine candidate genes were downregulated remarkably in NSCL lip tissues, and these three genes' abnormal methylation loci were validated by pyrosequencing in 16 NSCL cases and 15 healthy cases.@*Results@#In total, 4879 sites in the genes of NSCL odinopoeia fetuses showed aberrant methylation when compared with normal lip tissue genome. Among these, 3661 sites were hypermethylated and 1218 sites were hypomethylated as compared to methylation levels in healthy specimens. These aberrant methylation sites involved 2849 genes and were widely distributed among the chromosomes. Most differentially methylated sites were located in cytosine-phosphoric acid-guanine islands. Based on GO analysis, aberrantly methylated genes were involved in 11 cellular components, 13 molecular functions, and a variety of biological processes. Notably, the transcription of DAB1, REELIN, and FYN was significantly downregulated in lesion tissues of NSCL fetus (P < 0.05). Pyrosequencing results validated that there were two loci in DAB1 with high methylation status in patient tissues (P < 0.05).@*Conclusions@#We detected numerous aberrantly methylated loci in lesion tissues of NSCL fetus. Aberrant gene expression in the REELIN signaling pathway might be related with NSCL. Decreased transcription of DAB1, a member of REELIN signal pathway, resulted from its abnormal high methylation, which might be one of the factors underlying the occurrence of NSCL.

Schizophrenia and reelin: a model based on prenatal stress to study epigenetics, brain development and behavior

Schizophrenia is a severe psychiatric disorder that results in a significant disability for the patient. The disorder is characterized by impairment of the adaptive orchestration of actions, a cognitive function that is mainly dependent on the prefrontal cortex. This behavioral deficit, together with cellular and neurophysiological alterations in the prefrontal cortex, as well as reduced density of GABAergic cells and aberrant oscillatory activity, all indicate structural and functional deficits of the prefrontal cortex in schizophrenia. Among the several risk factors for the development of schizophrenia, stress during the prenatal period has been identified as crucial. Thus, it is proposed that prenatal stress induces neurodevelopmental alterations in the prefrontal cortex that are expressed as cognitive impairment observed in schizophrenia. However, the precise mechanisms that link prenatal stress with the impairment of prefrontal cortex function is largely unknown. Reelin is an extracellular matrix protein involved in the development of cortical neural connectivity at embryonic stages, and in synaptic plasticity at postnatal stages. Interestingly, down-regulation of reelin expression has been associated with epigenetic changes in the reelin gene of the prefrontal cortex of schizophrenic patients. We recently showed that, similar to schizophrenic patients, prenatal stress induces down-expression of reelin associated with the methylation of its promoter in the rodent prefrontal cortex. These alterations were paralleled with altered prefrontal cortex functional connectivity and impairment in prefrontal cortex-dependent behavioral tasks. Therefore, considering molecular, cellular, physiological and behavioral evidence, we propose a unifying framework that links prenatal stress and prefrontal malfunction through epigenetic alterations of the reelin gene.

Microenvironments induce iPSCs and BMSCs into neuron-like cells--Reelin's regulative role in cell differentiation and polarization / 生理学报

The present study was aimed to investigate how the induced pluripotent stem cells (iPSCs) and bone marrow mesenchymal stem cells (BMSCs) differentiate into neuron-like cells under the induction of hippocampal microenvironments and Reelin's regulation. iPSCs or BMSCs were co-cultured with WT (wild type) or genotypic hippocampal slice and cerebral homogenate supernatant, then the stem cells' differentiation under the induction of hippocampal environment was observed by using immunofluorescence technique. In the meantime, stem cells were co-cultured with hippocampal slice and cerebral conditioned medium of reeler (Reelin deletion) mouse respectively. The results showed that both adhesive iPSCs and BMSCs on WT hippocampal slice exhibited lamination of double "C" shape with high density on granular and pyramidal layers. The stem cells could differentiate into neuron-like cells with obvious polarization on WT hippocampal slice. In pyramidal cell layer, the differentiated neuron-like cells were oriented vertically with similar shapes of pyramidal cell in vivo, and the cells within molecule layer were arranged horizontally. In addition, adhesive iPSCs and BMSCs could differentiate into Nestin positive neural stem cells and NeuN positive neurons, respectively, under WT hippocampal microenvironment. On the other hand, under induction of hippocampal microenvironment of reeler mouse, iPSCs and BMSCs differentiation could also be seen, but their lamination was in disorder, and cell polarization was irregular. Moreover, differentiation and polarization of the iPSCs and BMSCs were delayed. These results suggest both iPSCs and BMSCs can differentiate into neuron-like cells under the induction of hippocampal microenvironments. Reelin is involved in the regulation of neuronal differentiation and cell polarization. Without Reelin, the cellular lamination and polarization appear irregular, and the stem cells' differentiation is delayed.

Genome-Wide Association Study of Lung Cancer in Korean Non-Smoking Women

Lung cancer in never-smokers ranks as the seventh most common cause of cancer death worldwide, and the incidence of lung cancer in non-smoking Korean women appears to be steadily increasing. To identify the effect of genetic polymorphisms on lung cancer risk in non-smoking Korean women, we conducted a genome-wide association study of Korean female non-smokers with lung cancer. We analyzed 440,794 genotype data of 285 cases and 1,455 controls, and nineteen SNPs were associated with lung cancer development (P < 0.001). For external validation, nineteen SNPs were replicated in another sample set composed of 293 cases and 495 controls, and only rs10187911 on 2p16.3 was significantly associated with lung cancer development (dominant model, OR of TG or GG, 1.58, P = 0.025). We confirmed this SNP again in another replication set composed of 546 cases and 744 controls (recessive model, OR of GG, 1.32, P = 0.027). OR and P value in combined set were 1.37 and < 0.001 in additive model, 1.51 and < 0.001 in dominant model, and 1.54 and < 0.001 in recessive model. The effect of this SNP was found to be consistent only in adenocarcinoma patients (1.36 and < 0.001 in additive model, 1.49 and < 0.001 in dominant model, and 1.54 and < 0.001 in recessive model). Furthermore, after imputation with HapMap data, we found regional significance near rs10187911, and five SNPs showed P value less than that of rs10187911 (rs12478012, rs4377361, rs13005521, rs12475464, and rs7564130). Therefore, we concluded that a region on chromosome 2 is significantly associated with lung cancer risk in Korean non-smoking women.

A review on the current neuroligin mouse models / 生理学报

Neuroligins (NLs) are postsynaptic membrane proteins expressed in the brain and mediate synaptogenesis. Neuroligin family proteins can specifically induce either excitatory or inhibitory synapses. Deletions or point mutations in neuroligin genes are found in patients with autism spectrum disorders (ASD) or mental retardations. The dysfunctions of these mutations have been tested in multiple neuroligin mouse models. In most of the models, including the human autism-linked NL3 and NL4 mutation mice, there are social interaction defects, memory impairment and repetitive behaviors. Researchers also found the excitatory/inhibitory synapse ratio altered in those mice, as well as receptor subunit composition. However, inconsistencies and debates also exist between different research approaches. In this review, we summarize the neuroligin mouse models currently available, examine the detailed alterations detected in those mice and compare the differences within different mouse models or different investigation methods, to obtain an overall picture of the current progress on neuroligin mouse models.

Genome-wide scan of granular corneal dystrophy, type II: confirmation of chromosome 5q31 and identification of new co-segregated loci on chromosome 3q26.3

Granular corneal dystrophy, type II (CGD2; Avellino corneal dystrophy) is the most common corneal dystrophy among Koreans, but its pathophysiology is still poorly understood. Many reports showed that even though the causative mutation is the same TGFBI R124H mutation, there are severe and mild phenotypes of the corneal dystrophy. We also observed the phenotype differences in our samples. For this reason, we focused our effort on the identification of unknown genetic factor related to phenotype variation. A total 551 individuals from 59 families were genotyped with SNP chip and used in genome-wide linkage analysis. From single-point linkage analyses, we confirmed the known 5q31 region for TGFBI gene, and selected novel nine candidate loci for CGD2. In simulation analysis, the only 3q26.3 region including neuroligin 1 gene (NLGN1) was supported by empirical statistic significance. To investigate the effect of genetic heterogeneity in linkage analysis, we classified CGD2 families into two subgroups. Although we could not find a significant evidence for correlation between the 3q26.3 region and CGD2 phenotypes, this first genome-wide analysis with CGD2 families in Korea has a very important value for offering insights in genetics of CGD2. In addition, the co-segregating loci with CGD2 including 3q26.3 would be a good target for further study to understand the pathophysiology of CGD2.

Role of cell adhesion molecules Necl1 in synaptogenesis in primary cultured rat neurons / 中国医学科学院学报

<p><b>OBJECTIVE</b>To study the role of cell adhesion molecules Necl1 in synaptogenesis in primary cultured neurons.</p><p><b>METHODS</b>Semi-quantitive reverse transcription polymerase chain reaction (RT-PCR) was used to detect the expression pattern of Necl1 in the neuronal differentiation cell model in vitro. Western blot was performed to detect the expression pattern of Necl1 in primary cultured rat neurons and in purified synaptosome. Immunofluoresence was used to detect the synapse formation in primary neurons and in 293 cells co-culture and to detect the density of synapses in primary neuron with ectopic expression of Necl1.</p><p><b>RESULTS</b>Necl1 expression increased after retinoic acid (RA) induction in SH-SY5Y and P19 cells. The increase of Necl1 expression was consistent with the days of primary neurons culture in vitro, and Necl1 partly localized in synaptosome. The overexpression of Necl1 in 293 cells induced the synapse formation between cocultured 293 cells and neurons. Ectopic expression of Necl1 in primary neurons increased the density of synapses.</p><p><b>CONCLUSION</b>Necl1 plays an important role in neuronal synapse formation.</p>

The extracellular matrix provides directional cues for neuronal migration during cerebellar development

Normal central nervous system development relies on accurate intrinsic cellular programs as well as on extrinsic informative cues provided by extracellular molecules. Migration of neuronal progenitors from defined proliferative zones to their final location is a key event during embryonic and postnatal development. Extracellular matrix components play important roles in these processes, and interactions between neurons and extracellular matrix are fundamental for the normal development of the central nervous system. Guidance cues are provided by extracellular factors that orient neuronal migration. During cerebellar development, the extracellular matrix molecules laminin and fibronectin give support to neuronal precursor migration, while other molecules such as reelin, tenascin, and netrin orient their migration. Reelin and tenascin are extracellular matrix components that attract or repel neuronal precursors and axons during development through interaction with membrane receptors, and netrin associates with laminin and heparan sulfate proteoglycans, and binds to the extracellular matrix receptor integrins present on the neuronal surface. Altogether, the dynamic changes in the composition and distribution of extracellular matrix components provide external cues that direct neurons leaving their birthplaces to reach their correct final location. Understanding the molecular mechanisms that orient neurons to reach precisely their final location during development is fundamental to understand how neuronal misplacement leads to neurological diseases and eventually to find ways to treat them.

A modified method to isolate and identify the adult mesenchymal stem cells from human bone marrow / 中国实验血液学杂志

The study was aimed to establish a protocol of isolating and culturing adult mesenchymal stem cells (MSC) from human bone marrow aspirate and identify them by surface antigen analysis and committed differentiation in order to provide an experimental foundation for achieving a therapeutic benefit in applying MSC in hematopoietic stem cell transplantation. MSCs were obtained from fresh human bone marrow aspirate by gradient centrifugation with Percoll (1.073 g/ml) and anchoring culture in L-DMEM with 10% fetal bovine serum by a full medium exchange every 3 days. The MSC surface antigens, including CD34, CD45, CD73, CD105, CD166, were analyzed on FACScan flow cytometer. Under culture in conditioned medium for osteogenesis (the hormone cocktail containing 0.1 micromol/L dexamethasone, 10 mmol/L glycerol-2-phosphate and 50 micromol/L ascorbic acid) and adipogenesis (the cocktail containing 1 micromol/L dexamethasone, 5 mg/L insulin, 0.5 mmol/L 1-methyl-3-isobutylxanthine and 60 micromol/L indomethacin), MSCs committedly differentiated into osteoblasts and adipocytes. The differentiated mesenchymal stem cells were identified by morphological observation and immunohistochemical staining. The results showed that by gradient centrifugation and adhesion culture, MSCs could be isolated and culture-expanded from human bone marrow aspirate. These cells were uniformly negative for CD34, CD45 and positive for CD73, CD105 and CD166. The osteogenic differentiated cells were positive for alkaline phosphatase (ALP) and the adipogenic differentiated cells displayed accumulation of lipid vacuoles, as detected by oil red O. It is concluded that MSC can be isolated and expand-cultured from adult human bone marrow aspirate and committedly differentiate into osteoblasts and adipocytes. MSC primary identification can be accomplished by flow cytometry and induced differentiation. The set of methods in current experiment shows somewhat practical value for basic research and clinical application.

Ehi neonatal: Lem, o el premio a la superviviencia / Ehi newborn: Lem, or the prize to the survival

La hipoxia- isquemica es la principal causa de injuria del sistema nerviosos central en el feto y en el recién nacido, situación agravada, en algunas circunstancias, por infección intrauterina y respuesta inflamatoria fetal. La reducción en las cifras de mortalidad ha producido un incremento de morbilidad, la posibilidad de asistir a las secuelas de aquellas lesiones. En el niño pretérmino que sobrevive, el sustrato morfológico más frecuente de parálisis cerebral es la lucoencefalomalacia pereventricular, la cual forma parte de un expectro más amplio. Las secuelas son déficit en la mielinización, la pérdida de volúmen de sustancia blanca con consecuente ventriculomegalia, el compromiso de vías largas relacionado con el déficit motor del cuadro clínico de páralisis cerebral. En este artículo se sitúa a la leucoencefalomalacia periventricular en el expectro de lesiones hipóxico, isquémica del recién nacido, se detallan sus características clínicas y macra-microscópicas, y se comentan los recientes aportes de la fisiopatología celular. El rol principal del glutamato, la teoría de la excototoxicidad, las citoquinas, y la cascada inflamatoria operan a través de ventanas de vulnerabilidad, que exponen a la oligodendroglia como target esencial, y a la apoptosis como un mecanismo importante de lesión cerebral

Ubiquitous overexpression of a transgene encoding the extracellular portion of the Drosophila Roughest-Irregular Chiasm C protein induces early embryonic lethality

The cell adhesion molecule Rst-irreC is a transmembrane glycoprotein of the immunoglobulin superfamily involved in several important developmental processes in Drosophila, including axonal pathfinding in the optic lobe and programmed cell death and pigment cell differentiation in the pupal retina. As an initial step towards the "in vivo" functional analysis of this protein we have generated transgenic fly stocks carrying a truncated cDNA construct encoding only the extracellular domain of Rst-IrreC under the transcriptional control of the heat shock inducible promoter hsp70. We show that heat-shocking embryos bearing the transgene during the first 8hs of development lead to a 3-4 fold reduction in their viability compared to wild type controls. The embryonic lethality can already be produced by applying the heat pulse in the first 3hs of embryonic development, does not seem to be suppressed in the absence of wildtype product and is progressively reduced as the heat treatment is applied later in embryogenesis. These results are compatible with the hypothesis of the lethal phenotype being primarily due to heterophilic interactions between Rst-IrreC extracellular domain and an yet unknown ligand.

Immunohistochemical Localization of NCAM at Neuromuscular Contacts in Rat Muscle-Rat Nerve Cocultures / 대한해부학회지

Neuromuscular junction formation is one of the hot research area for understanding synapse formation, and the contact and adhesion between muscle and neurons during this procedure is regarded as one of important steps for synaptogenesis. The changes of neuronal cell adhesion molecules during nerve-muscle contats has not been revealed yet. In this study, we isolated skeletal muscle cells and ventral spinal cord neurons from Sprague-Dawley rats and observed the contact areas with a transmission electron microscpe and studied the presence of NCAM at the contact sites by immunohistochemistry. The ventral spinal cord neuronal processes contact intimately with skeletal muscle cells, some of which were submerged into the muscle surface and had synaptic vesicles. NCAM was expressed on neuronal processes, only sialylated form were associated with acetylcholine receptor aggregates. These results confirmed the significance of adhesion in neuromuscular junction formation and NCAM may participate in this process by preventing the separation of 2 cells at the contact site.