Overview: Research on the Genetic Architecture of the Developing Cerebral Cortex in Norms and Diseases

The human brain is characterized by high cell numbers, diverse cell types with diverse functions, and intricate connectivity with an exceedingly broad surface of the cortex. Human-specific brain development was accomplished by a long timeline for maturation from the prenatal period to the third decade of life. The long timeline makes complicated architecture and circuits of human cerebral cortex possible, and it makes human brain vulnerable to intrinsic and extrinsic insults resulting in the development of variety of neuropsychiatric disorders. Unraveling the molecular and cellular processes underlying human brain development under the elaborate regulation of gene expression in a spatiotemporally specific manner, especially that of the cortex will provide a biological understanding of human cognition and behavior in health and diseases. Global research consortia and the advancing technologies in brain science including functional genomics equipped with emergent neuroinformatics such as single-cell multiomics, novel human models, and high-volume databases with high-throughput computation facilitate the biological understanding of the development of the human brain cortex. Knowing the process of interplay of the genome and the environment in cortex development will lead us to understand the human-specific cognitive function and its individual diversity. Thus, it is worthwhile to overview the recent progress in neurotechnology to foresee further understanding of the human brain and norms and diseases.

Association of moderately abnormal behavior and administered neuraminidase inhibitors

Our earlier study investigated the incidence of severe abnormal behavior associated with neuraminidase inhibitors (NIs), but some studies have specifically examined the association of oseltamivir use and moderately abnormal behavior. Therefore, this study was undertaken to assess associations between moderately abnormal behavior and administered drugs. All cases of patients with influenza who exhibited moderately abnormal behavior were reported to us by physicians of all sentinel clinics and hospitals for influenza throughout Japan. Open Data of the National Database of Electronic Medical Claims include the numbers of patients diagnosed as having influenza who were prescribed NI. Incidence by NI was tested using Fisher's exact test. We received 518 moderately abnormal cases in 5-9-year-olds and 207 moderately abnormal behavior cases in 10-19-year-olds. The incidence among NI ranged from 193 per one million influenza patients in laninamivir among 10-19-year-olds to 1021 for peramivir among 5-9-year-olds. Estimation results revealed the order of risk among NIs as peramivir, oseltamivir, zanamivir and laninamivir in moderate abnormal behavior. Because of data limitations, risk among patients with and without NI cannot be compared.

Inquiry into some gap among oseltamivir use and severe abnormal behavior in Japanese children and adolescents with influenza

The Fukushima research has examined data form a cohort study of 10,000 Japanese children under 18 years old with influenza during three months to demonstrate that the relative risk of A-type abnormal behavior of patients with oseltamivir was 30 times greater than without oseltamivir. By contrast, our research group found that patients who had been administered no neuraminidase inhibitors (NI) or those administered peramivir had higher risk of abnormal behavior than those administered oseltamivir, zanamivir, or laninamivir. A plausible explanation for this gap is that the two studies specifically examined different criteria to report abnormal behavior. In actually, some A-type abnormal behavior might not be life-threatening. Our definition of severe abnormal behavior is better matched to public health concerns and comparison among incidents according to the administered drug is more appropriate as an analytical procedure.

Role of Class III phosphoinositide 3-kinase in the brain development: possible involvement in specific learning disorders

Class III phosphoinositide 3-kinase (PIK3C3 or mammalian vacuolar protein sorting 34 homolog, Vps34) regulates vesicular trafficking, autophagy, and nutrient sensing. Recently, we reported that PIK3C3 is expressed in mouse cerebral cortex throughout the developmental process, especially at early embryonic stage. We thus examined the role of PIK3C3 in the development of the mouse cerebral cortex. Acute silencing of PIK3C3 with in utero electroporation method caused positional defects of excitatory neurons during corticogenesis. Time-lapse imaging revealed that the abnormal positioning was at least partially because of the reduced migration velocity. When PIK3C3 was silenced in cortical neurons in one hemisphere, axon extension to the contralateral hemisphere was also delayed. These aberrant phenotypes were rescued by RNAi-resistant PIK3C3. Notably, knockdown of PIK3C3 did not affect the cell cycle of neuronal progenitors and stem cells at the ventricular zone. Taken together, PIK3C3 was thought to play a crucial role in corticogenesis through the regulation of excitatory neuron migration and axon extension. Meanwhile, when we performed comparative genomic hybridization on a patient with specific learning disorders, a 107 Kb-deletion was identified on 18q12.3 (nt. 39554147-39661206) that encompasses exons 5-23 of PIK3C3. Notably, the above aberrant migration and axon growth phenotypes were not rescued by the disease-related truncation mutant (172 amino acids) lacking the C-terminal kinase domain. Thus, functional defects of PIK3C3 might impair corticogenesis and relate to the pathophysiology of specific learning disorders and other neurodevelopmental disorders. Acute knockdown of Class III phosphoinositide 3-kinase (PIK3C3) evokes migration defects of excitatory neurons during corticogenesis. PIK3C3-knockdown also disrupts axon outgrowth, but not progenitor proliferation in vivo. Involvement of PIK3C3 in neurodevelopmental disorders might be an interesting future subject since a deletion mutation in PIK3C3 was detected in a patient with specific learning disorders (SLD).

The association of GPR85 with PSD-95-neuroligin complex and autism spectrum disorder: a molecular analysis

Background

Autism spectrum disorder (ASD) has a complex genetic etiology. Some symptoms and mutated genes, including neuroligin (NLGN), neurexin (NRXN), and SH3 and multiple ankyrin repeat domains protein (SHANK), are shared by schizophrenia and ASD. Little is known about the molecular pathogenesis of ASD. One of the possible molecular pathogenesis is an imbalance of excitatory and inhibitory receptors linked with the NLGN-PSD-95-SHANK complex via postsynaptic density protein/Drosophila disc large tumor suppressor/zonula occludens-1 protein (PDZ) binding. In the present study, we focused on GPR85 as a candidate gene for ASD because the C-terminal amino acid sequence of GPR85 [Thr-Cys-Val-Ile (YCVI)] is classified as a type II PDZ-binding motif, and GPR85 is a risk factor for schizophrenia. GPR85 is an orphan receptor that regulates neural and synaptic plasticity and modulates diverse behaviors, including learning and memory. While searching for molecules that associate with GPR85, we found that GPR85 was associated with postsynaptic density protein (PSD)-95 linked with NLGN in the brain.

Methods

We examined the proteins that associate with the C-terminal sequence of GPR85 by pull-down assay and immunoblot analysis and searched for a mutation of the GPR85 gene in patients with ASD. We used immunostaining to examine the intracellular localization of mutated GPR85 and its influence on the morphology of cells and neurons.

Results

The C-terminal sequence of GPR85 interacted with PSD-95 at PDZ1, while NLGN interacted with PSD-95 at PDZ3. Two male patients with ASD from independent Japanese families possessed inherited missense mutations at conserved sites in GPR85: one had T1033C (M152T) and the other had G1239T (V221L). These mutations were located in a domain related to G protein interaction and signal transduction. In contrast to wild-type GPR85, mutated GPR85 was more preferentially accumulated, causing endoplasmic reticulum stress, and disturbed the dendrite formation of hippocampal neurons.

Conclusions

GPR85 associated with the PSD-95 linked with NLGN, which is related to ASD. GPR85 carrying the mutations detected in ASD patients disturbed dendrite formation that could be the candidate for molecular pathogenesis of ASD through the associated NLGN-PSD-95 receptor complex.

Electronic supplementary material

The online version of this article (doi:10.1186/s13229-015-0012-5) contains supplementary material, which is available to authorized users.

Neuropharmacological effect of atomoxetine on attention network in children with attention deficit hyperactivity disorder during oddball paradigms as assessed using functional near-infrared spectroscopy

The current study aimed to explore the neural substrate for atomoxetine effects on attentional control in school-aged children with attention deficit hyperactivity disorder (ADHD) using functional near-infrared spectroscopy (fNIRS), which can be applied to young children with ADHD more easily than conventional neuroimaging modalities. Using fNIRS, we monitored the oxy-hemoglobin signal changes of 15 ADHD children (6 to 14 years old) performing an oddball task before and 1.5 h after atomoxetine or placebo administration, in a randomized, double-blind, placebo-controlled, crossover design. Fifteen age-, gender-, and intelligence quotient-matched normal controls without atomoxetine administration were also monitored. In the control subjects, the oddball task recruited the right prefrontal and inferior parietal cortices. The right prefrontal and parietal activation was normalized after atomoxetine administration in ADHD children. This was in contrast to our previous study using a similar protocol showing methylphenidate-induced normalization of only the right prefrontal function. fNIRS allows the detection of differential neuropharmacological profiles of both substances in the attentional network: the neuropharmacological effects of atomoxetine to upregulate the noradrenergic system reflected in the right prefrontal and inferior parietal activations and those of methylphenidate to upregulate the dopamine system reflected in the prefrontal cortex activation.

Role of an adaptor protein Lin-7B in brain development: possible involvement in autism spectrum disorders

Using comparative genomic hybridization analysis for an autism spectrum disorder (ASD) patient, a 73-Kb duplication at 19q13.33 (nt. 49 562 755-49 635 956) including LIN7B and 5 other genes was detected. We then identified a novel frameshift mutation in LIN7B in another ASD patient. Since LIN7B encodes a scaffold protein essential for neuronal function, we analyzed the role of Lin-7B in the development of cerebral cortex. Acute knockdown of Lin-7B with in utero electroporation caused a delay in neuronal migration during corticogenesis. When Lin-7B was knocked down in cortical neurons in one hemisphere, their axons failed to extend efficiently into the contralateral hemisphere after leaving the corpus callosum. Meanwhile, enhanced expression of Lin-7B had no effects on both cortical neuron migration and axon growth. Notably, silencing of Lin-7B did not affect the proliferation of neuronal progenitors and stem cells. Taken together, Lin-7B was found to play a pivotal role in corticogenesis through the regulation of excitatory neuron migration and interhemispheric axon growth, while further analyses are required to directly link functional defects of Lin-7B to ASD pathophysiology. Lin-7 plays a pivotal role as a scaffold protein in synaptic development and plasticity. Based on genetic analyses we identified mutations in LIN-7B gene in some ASD (autism-spectrum disorder) patients. Functional defects in Lin-7B caused abnormal neuronal migration and interhemispheric axon growth during mouse brain development. Thus, functional deficiency in Lin-7B could be implicated in clinical phenotypes in some ASD patients through bringing about abnormal cortical architecture.

Acute neuropharmacological effects of atomoxetine on inhibitory control in ADHD children: a fNIRS study

The object of the current study is to explore the neural substrate for effects of atomoxetine (ATX) on inhibitory control in school-aged children with attention deficit hyperactivity disorder (ADHD) using functional near-infrared spectroscopy (fNIRS). We monitored the oxy-hemoglobin signal changes of sixteen ADHD children (6–14 years old) performing a go/no-go task before and 1.5 h after ATX or placebo administration, in a randomized, double-blind, placebo-controlled, crossover design. Sixteen age- and gender-matched normal controls without ATX administration were also monitored. In the control subjects, the go/no-go task recruited the right inferior and middle prefrontal gyri (IFG/MFG), and this activation was absent in pre-medicated ADHD children. The reduction of right IFG/MFG activation was acutely normalized after ATX administration but not placebo administration in ADHD children. These results are reminiscent of the neuropharmacological effects of methylphenidate to up-regulate reduced right IFG/MFG function in ADHD children during inhibitory tasks. As with methylphenidate, activation in the IFG/MFG could serve as an objective neuro-functional biomarker to indicate the effects of ATX on inhibitory control in ADHD children. This promising technique will enhance early clinical diagnosis and treatment of ADHD in children, especially in those with a hyperactivity/impulsivity phenotype.

•

We assessed the effects of atomoxetine administration to ADHD children using fNIRS.

•

Normal healthy control subjects recruited the right IFG/MFG during go/no-go tasks.

•

Pre-medicated ADHD children exhibited reduced right IFG/MFG activation.

•

The activation was acutely normalized by atomoxetine, but not by placebo.

•

The right IFG/MFG activation may serve as an objective neuro-functional biomarker.

Neuropharmacological effect of methylphenidate on attention network in children with attention deficit hyperactivity disorder during oddball paradigms as assessed using functional near-infrared spectroscopy

The current study aimed to explore the neural substrate for methylphenidate effects on attentional control in school-aged children with attention deficit hyperactivity disorder (ADHD) using functional near-infrared spectroscopy (fNIRS), which can be applied to young children with ADHD more easily than conventional neuroimaging modalities. Using fNIRS, we monitored the oxy-hemoglobin signal changes of 22 ADHD children (6 to 14 years old) performing an oddball task before and 1.5 h after methylphenidate or placebo administration, in a randomized, double-blind, placebo-controlled, crossover design. Twenty-two age- and gender-matched normal controls without methylphenidate administration were also monitored. In the control subjects, the oddball task recruited the right prefrontal and inferior parietal cortices, and this activation was absent in premedicated ADHD children. The reduced right prefrontal activation was normalized after methylphenidate but not placebo administration in ADHD children. These results are consistent with the neuropharmacological effects of methylphenidate to upregulate the dopamine system in the prefrontal cortex innervating from the ventral tegmentum (mesocortical pathway), but not the noradrenergic system from the parietal cortex to the locus coeruleus. Thus, right prefrontal activation would serve as an objective neurofunctional biomarker to indicate the effectiveness of methylphenidate on ADHD children in attentional control. fNIRS monitoring enhances early clinical diagnosis and the treatment of ADHD children, especially those with an inattention phenotype.

Williams-Beuren syndrome with brain malformation and hypertrophic cardiomyopathy

Williams-Beuren syndrome (WBS) is a multisystemic genetic disorder caused by a contiguous gene deletion at 7q11.23. We report a severely affected WBS patient with cerebral and cerebellar dysplasia as well as hypertrophic cardiomyopathy. Microarray comparative genomic hybridization (aCGH) detected a deletion on 7q11.23 expanding from RP11-614D7 to RP11-137E8, which is a typical deletion in WBS. To the best of our knowledge, this is the first case report of a WBS patient with severe congenital central nervous system anomaly and progressive hypertrophic cardiomyopathy. The relationship between the genes deleted in WBS and a CNS anomaly plus hypertrophic cardiomyopathy requires further analysis.

Utility of non-enhanced magnetic resonance imaging to detect acute pyelonephritis

It has been established that enhanced computed tomography (CT) and (99m) Tc-dimercaptosuccinic acid renal scintigraphy ((99m) Tc-DMSA scintigraphy) used in conjunction with single-photon emission CT is a useful tool for the diagnosis of acute pyelonephritis (APN). The utility of non-enhanced magnetic resonance imaging (MRI), however, has not been investigated extensively for the diagnosis of APN or renal abscess in children. We describe the case of a 23-month-old boy with suspected APN who received non-enhanced MRI. Whole body diffusion-weighted imaging (DWI) was used, and a background body-signal suppression sequence was applied. High-intensity focal lesions were identified on DWI and low-intensity lesions on the apparent diffusion coefficient map in the acute phase. This case suggested that non-enhanced MRI could be a useful tool for the diagnosis of APN in children, because it can avoid the risks of not only radiation exposure but also nephrogenic systemic fibrosis associated with gadolinium-based contrast agents, especially in infants.

Cytokine dynamics in a 14-year-old girl with tubulointerstitial nephritis and uveitis syndrome

Tubulointerstitial nephritis and uveitis (TINU) syndrome, which was first described in 1975, has been reported in more than 130 patients, mostly in adolescent or young women. Although data concerning the etiologic background of this inflammatory disease are limited, several humoral factors, including cytokines, have been reported in association with the disease. Here, we report a case of TINU in a 14-year-old girl, whose renal and ophthalmological improvement was associated with the decrease of serum levels of tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), and interleukin-8 (IL-8). This suggests the presence of T-cell-mediated immunity in this unique syndrome.

LIN7A depletion disrupts cerebral cortex development, contributing to intellectual disability in 12q21-deletion syndrome

Interstitial deletion of 12q21 has been reported in four cases, which share several common clinical features, including intellectual disability (ID), low-set ears, and minor cardiac abnormalities. Comparative genomic hybridization (CGH) analysis using the Agilent Human Genome CGH 180K array was performed with the genomic DNA from a two-year-old Japanese boy with these symptoms, as well as hypoplasia of the corpus callosum. Consequently, a 14 Mb deletion at 12q21.2-q21.33 (nt. 77 203 574–91 264 613 bp), which includes 72 genes, was detected. Of these, we focused on LIN7A, which encodes a scaffold protein that is important for synaptic function, as a possible responsible gene for ID, and we analyzed its role in cerebral cortex development. Western blotting analyses revealed that Lin-7A is expressed on embryonic day (E) 13.5, and gradually increases in the mouse brain during the embryonic stage. Biochemical fractionation resulted in the enrichment of Lin-7A in the presynaptic fraction. Suppression of Lin-7A expression by RNAi, using in utero electroporation on E14.5, delayed neuronal migration on postnatal day (P) 2, and Lin-7A-deficient neurons remained in the lower zone of the cortical plate and the intermediate zone. In addition, when Lin-7A was silenced in cortical neurons in one hemisphere, axonal growth in the contralateral hemisphere was delayed; development of these neurons was disrupted such that one half did not extend into the contralateral hemisphere after leaving the corpus callosum. Taken together, LIN7A is a candidate gene responsible for 12q21-deletion syndrome, and abnormal neuronal migration and interhemispheric axon development may contribute to ID and corpus callosum hypoplasia, respectively.

Apolipoprotein AII levels are associated with the UP/UCr levels in idiopathic steroid-sensitive nephrotic syndrome

BACKGROUND

Various humoral factors have been proposed as causal agents of idiopathic steroid-sensitive nephrotic syndrome (ISSNS), resulting in varying data. We used mass spectrometry (MS) to analyze serum proteins in a search for proteins that might be involved in ISSNS pathophysiology.

METHODS

Serial serum samples were obtained from 33 children with ISSNS. Samples were collected during Phase A1 [the acute phase prior to steroid treatment (STx)], Phase A2 (remission with STx), and Phase A3 (remission without any medication). We also included age- and sex-matched two control groups comprising children with normal urinalysis (Group B) and children with a nephrotic syndrome other than ISSNS (Group C). The urinary protein/urinary creatinine (UP/UCr) ratios were not statistically different between Phase A1 and Group C. Samples were analyzed using surface-enhanced laser desorption/ionization time of flight MS.

RESULTS

A total of 207 peptide ion peaks were detected in the range of m/z 2000-10000. Four peptide ions (m/z 6444, 6626, 8695, and 8915) were detected at significant elevation during Phase A1 compared with Phase A2, Phase A3, and Group C. The intensities of m/z 6444 and 8695 were higher in Phase A3 than in Group B. There were significant correlations between the intensities of m/z 6626, 8695, and 8915 and UP/UCr levels. The m/z 8695 was identified as apolipoprotein AII.

CONCLUSIONS

Apolipoprotein AII was detected as a protein associated with the UP/UCr levels in pediatric ISSNS. Our findings present an interesting starting point for further investigation into the pathophysiology of ISSNS.

MAOA/B deletion syndrome in male siblings with severe developmental delay and sudden loss of muscle tonus

Deletion of the monoamine oxidase (MAO)-A and MAO-B was detected in two male siblings and in their mother. The approximately 800-kb deletion, extending from about 43.0MB to 43.8MB, was detected by array comparative genomic hybridization analysis. The MAOA and MAOB genes were included in the deletion, but the adjacent Norrie disease gene, NDP, was not deleted. The boys had short stature, hypotonia, severe developmental delays, episodes of sudden loss of muscle tone, exiting behavior, lip-smacking and autistic features. The serotonin levels in their cerebrospinal fluid were extremely elevated. Another set of siblings with this deletion was reported previously. We propose recognition of MAOA/B deletion syndrome as a distinct disorder.

Late-onset Leigh syndrome with myoclonic epilepsy with ragged-red fibers

We report the case of a boy with myoclonic epilepsy with ragged-red fibers (MERRF) who had astatic seizures since 2 years of age and later developed ataxia, absence seizures, and myoclonus. Almost homoplasmic A8344G mutation of mitochondrial DNA (m.8344A>G mutation) was detected in lymphocytes. He developed late-onset Leigh syndrome (LS) when he contracted pneumonia at 6 years. He developed bulbar palsy and deep coma. MRI demonstrated lesions in the brainstem, basal ganglia, and cerebral cortex. Three similar cases have been reported; two carried the almost-homoplasmic m.8344A>G mutation in muscle tissue. These suggested that almost homoplastic m.8344A>G mutation developed clinical phenotype of MERRF in the early stage and late-onset Leigh syndrome in the late course of the disease.

Mutation in Parkinson disease-associated, G-protein-coupled receptor 37 (GPR37/PaelR) is related to autism spectrum disorder

Little is known about the molecular pathogenesis of Autism spectrum disorder (ASD), a neurodevelopmental disorder. Here we identified two mutations in the G-protein-coupled receptor 37 gene (GPR37) localized on chromosome 7q31–33, called the AUTS1 region, of ASD patients; 1585–1587 ttc del (Del312F) in one Japanese patient and G2324A (R558Q) in one Caucasian patient. The Del312F was located in the conserved transmembrane domain, and the R558Q was located in a conserved region just distal to the last transmembrane domain. In addition, a potential ASD-related GPR37 variant, T589M, was found in 7 affected Caucasian men from five different families. Our results suggested that some alleles in GPR37 were related to the deleterious effect of ASD. GPR37 is associated with the dopamine transporter to modulate dopamine uptake, and regulates behavioral responses to dopaminergic drugs. Thus, dopaminergic neurons may be involved in the ASD. However, we also detected the Del321F mutation in the patient's unaffected father and R558Q in not only an affected brother but also an unaffected mother. The identification of unaffected parents that carried the mutated alleles suggested that the manifestation of ASD was also influenced by factors other than these mutations, including endoplasmic reticulum stress of the mutated proteins or gender. Our study will provide the new insight into the molecular pathogenesis of ASD.

Increased α1-antitrypsin levels in acute-phase Kawasaki disease as shown by SELDI-TOF MS analysis

Various agents have been suggested as causal or associated factors in the pathogenesis of Kawasaki disease (KD); however, the underlying factors of KD remain unknown. Plasma exchange is one of the most effective treatments for the acute phase of KD. This indicates that plasma may contain factors associated with the pathogenesis of KD. To search for proteins that may be involved in KD pathogenesis, we analyzed serum proteins with surface-enhanced laser desorption/ionization time of flight mass spectrometry (SELDI-TOF MS). Serum samples were obtained from 17 KD patients. Serum from six of the patients was collected during acute phase before acetylsalicylic acid (ASA) and intravenous immunoglobulin administration (phase A1), during remission with ASA (phase A2), and during remission without any medication (phase A3). Serum from the remaining 11 patients was collected for phases A1 and A2 only. There were two age- and sex-matched control groups comprising 8 afebrile healthy children (group B) and 8 febrile children with several infectious diseases (group C). There were no statistical differences in laboratory examination between phase A1 and group C except for albumin level, alanine aminotransferase, or sodium level. Serum samples were analyzed by SELDI-TOF MS after purification. We detected five peaks, i.e., those were specifically increased or decreased during phase A1, and identified 1 of these as α1-antitrypsin (α1-AT). α1-AT can inhibit neutrophil elastase activity. This elastase is thought to play a role in coronary artery damage. Our findings present an interesting starting point for further investigations into the pathophysiology of KD.

Successful treatment with pulse cyclophosphamide of a steroid-refractory hepatitic variant of liver acute graft-vs.-host disease in a child

A 13-yr-old boy with recurrent acute myeloid leukemia underwent HSCT using cells from an unrelated donor who matched all HLA antigens except one. Forty-two days later, the patient developed a steroid-refractory hepatitic variant of liver GVHD with peak ALT and T.Bil values of 1406 mU/mL and 10.4 mg/dL, respectively. He was successfully treated with pulse Cy (1000 mg/dose × one day) without a change in chimerism being observed or acquiring an infection. All immunosuppressant therapies could be discontinued 12 months after HSCT. Two yr after HSCT, the patient remains in CR without chronic GVHD. This single case report suggests that pulse Cy may be a promising therapy for steroid-refractory GVHD, especially hepatitic GVHD, but needs to be further tested in clinical trials.

A complex of synaptic adhesion molecule CADM1, a molecule related to autism spectrum disorder, with MUPP1 in the cerebellum

Mutations in the synaptic adhesion protein CADM1 (RA175/SynCAM1) are associated with autism spectrum disorder (ASD), a neurodevelopmental disorder of uncertain molecular origin. Cadm1-knock out (KO) mice exhibit smaller cerebella with decreased number of synapse of Purkinje cells and some ASD-like symptoms, including impaired ultrasonic vocalization. In this study, we examined the alteration of the Cadm1 synaptic complex in the mouse cerebellum at post-natal stages. The C-terminal peptide of Cadm1 associated with Mupp1 at PSD-95/Dlg/ZO-1 (PDZ)(1-5), a scaffold protein containing 13 PDZ domains, which interacted with gamma-aminobutyric acid type B receptor (GABBR)2 at PDZ13, but not with PSD-95. The GABBR2 was detected in a set of proteins interacting with Cadm1 C-terminal. Cadm1 colocalized with Mupp1 and GABBR2 on the dendrites of Purkinje cells in the molecular layers of the developing cerebellum and on the dendrites of hippocampal neurons cultured in vitro. These observations suggest that the Cadm1 synaptic receptor complex, including Mupp1-GABBR2, is located on the dendrites of Purkinje cells. The amount of GABBR2 protein, but not mRNA, was increased in the cerebella of Cadm1 KO mice, suggesting that lack of Cadm1 does not affect transcription of GABBR2, but may stabilize the Mupp1-GABBR2 complex; the Mupp1-GABBR2 interaction may be stabilized by conformational change in Mupp1 or association with other adhesion molecules and by anchorage to the post-synaptic membrane. Up-regulation of GABBR2 in the cerebellum in the absence of CADM1 may be associated with ASD pathogenesis.

Cadm1-expressing synapses on Purkinje cell dendrites are involved in mouse ultrasonic vocalization activity

Foxp2(R552H) knock-in (KI) mouse pups with a mutation related to human speech-language disorders exhibit poor development of cerebellar Purkinje cells and impaired ultrasonic vocalization (USV), a communication tool for mother-offspring interactions. Thus, human speech and mouse USV appear to have a Foxp2-mediated common molecular basis in the cerebellum. Mutations in the gene encoding the synaptic adhesion molecule CADM1 (RA175/Necl2/SynCAM1/Cadm1) have been identified in people with autism spectrum disorder (ASD) who have impaired speech and language. In the present study, we show that both Cadm1-deficient knockout (KO) pups and Foxp2(R552H) KI pups exhibit impaired USV and smaller cerebellums. Cadm1 was preferentially localized to the apical-distal portion of the dendritic arbor of Purkinje cells in the molecular layer of wild-type pups, and VGluT1 level decreased in the cerebellum of Cadm1 KO mice. In addition, we detected reduced immunoreactivity of Cadm1 and VGluT1 on the poorly developed dendritic arbor of Purkinje cells in the Foxp2(R552H) KI pups. However, Cadm1 mRNA expression was not altered in the Foxp2(R552H) KI pups. These results suggest that although the Foxp2 transcription factor does not target Cadm1, Cadm1 at the synapses of Purkinje cells and parallel fibers is necessary for USV function. The loss of Cadm1-expressing synapses on the dendrites of Purkinje cells may be associated with the USV impairment that Cadm1 KO and Foxp2(R552H) KI mice exhibit.

Elevated serum interleukin-7 level in idiopathic steroid-sensitive nephrotic syndrome

BACKGROUND

Several cytokines have a pathological association with idiopathic steroid-sensitive nephrotic syndrome (ISSNS) in inducing proteinuria or regulating T cells. Because interleukin (IL)-7 plays important roles in regulating T-cell proliferation and sustaining naïve or memory T cells, IL-7 is one of the candidate cytokines in the pathogenesis of ISSNS. Very little is known, however, about the association of IL-7 with ISSNS. To clarify the IL-7 dynamics in children with ISSNS, serum IL-7 level was investigated, from the nephrotic phase before steroid treatment (STx; group A1) to the remission phase with STx (group A2) and without STx (group A3).

METHODS

Eighteen children with ISSNS were included in the present study. A total of 25 paired samples were analyzed for groups A1 and A2, and a total of 10 paired samples for groups A1, A2, and A3 due to recurrence. Two control groups (with normal urinalysis, group B; or with nephrotic syndrome other than ISSNS, group C), matched for age and gender, were also included. Serum cytokine level was measured on bead-based assay.

RESULTS

Each serum IL-7 level in groups A1 and A3 was higher than each serum IL-7 level of groups C and B, respectively. The group A2 serum IL-7 level was higher than that of group A1. There was no statistical significance of serum IL-7 level between group A1 and group A3.

CONCLUSION

Serum IL-7 level was elevated in children with ISSNS regardless of the status of the disease. This brings us one step closer to a better understanding of the pathophysiology of ISSNS in children.

Cntnap2 expression in the cerebellum of Foxp2(R552H) mice, with a mutation related to speech-language disorder

Foxp2(R552H) knock-in (KI) mice carrying a mutation related to human speech-language disorder exhibit impaired ultrasonic vocalization and poor Purkinje cell development. Foxp2 is a forkhead domain-containing transcriptional repressor that associates with its co-repressor CtBP; Foxp2(R552H) displays reduced DNA binding activity. A genetic connection between FOXP2 and CNTNAP2 has been demonstrated in vitro, but not in vivo. Here we show that Cntnap2 mRNA levels significantly increased in the cerebellum of Foxp2(R552H) KI pups, although the cerebellar population of Foxp2-positive Purkinje cells was very small. Furthermore, Cntnap2 immunofluorescence did not decrease in the poorly developed Purkinje cells of Foxp2(R552H) KI pups, although synaptophysin immunofluorescence decreased. Cntnap2 and CtBP were ubiquitously expressed, while Foxp2 co-localized with CtBP only in Purkinje cells. Taken together, these observations suggest that Foxp2 may regulate ultrasonic vocalization by associating with CtBP in Purkinje cells; Cntnap2 may be a target of this co-repressor.

Clinically-oriented monitoring of acute effects of methylphenidate on cerebral hemodynamics in ADHD children using fNIRS

OBJECTIVE

Attention Deficit Hyperactivity Disorder (ADHD), a common developmental syndrome with inattention, hyperactivity, and impulsivity, is typically treated with the psychostimulant drug, methylphenidate (MPH). We explored the feasibility of using functional near-infrared spectroscopy (fNIRS) to search for a clinically implementable biological marker for the acute MPH effect on ADHD children.

METHODS

Following an MPH washout period, twelve ADHD children performed a go/no-go task before and 1.5 h after MPH intake. fNIRS was used to monitor the lateral prefrontal cortical hemodynamics of ADHD children performing a go/no-go task.

RESULTS

There was no significant activation in the lateral prefrontal cortices examined before MPH intake. However, after MPH intake, significant MPH-elicited activation (oxygenated hemoglobin signal increase) was detected in the right lateral prefrontal cortex (LPFC) implicated with response inhibition functions. There was a large significant correlation between increases in task performance and activation in the right LPFC.

CONCLUSIONS

The improved cognitive performance was associated with activation in the right LPFC, which might serve as a biological marker to monitor the effect of MPH in ADHD children.

SIGNIFICANCE

MPH-effect assessment in ADHD children using fNIRS can be performed within a 3 h stay at a hospital during a single visit, and thus may be integrated into clinical practice.

Selectively high level of serum interleukin 5 in a newborn infant with cow's milk allergy

Cow's milk allergy (CMA) in the neonatal period is thought to include several clinical conditions, yet the pathophysiology remains unclear. We report here the case of a term newborn infant who showed hematochezia 36 hours after the first feeding with cow's milk formula. His serum immunoglobulin E levels were not elevated, although eosinophils were detected in the stool. Elimination of cow's milk formula resolved the symptoms, and from the clinical course and laboratory data the infant was diagnosed with CMA. The serum interleukin 5 (IL-5) (125 pg/mL) level in this patient was selectively elevated. However, serum levels of other T-helper 2 (Th2) cytokines (including IL-4 and IL-13), Th1 cytokines (including interferon γ), and proinflammatory cytokines (including tumor necrosis factor α) were not elevated. These findings suggest that, for this patient, IL-5 and eosinophils might have played a role in the development of neonatal CMA. Although this finding is reported from only 1 case, it highlights the need for serum IL-5 to be determined in more neonatal patients with CMA to further clarify the pathophysiology of this condition in the neonatal period.

Association of development of chronic lung disease of newborns with neonatal colonization of Ureaplasma and cord blood interleukin-8 level

BACKGROUND

The aim of the present study was to investigate the association of chronic lung disease (CLD), neonatal Ureaplasma colonization, and interleukin-8 (IL-8) level of cord blood in preterm infants.

METHODS

In 77 infants of <32 weeks gestation, the relationship between IL-8 level of cord blood, neonatal colonization of Ureaplasma, histological chorioamnionitis (CAM), and development of CLD was studied.

RESULTS

Five infants died and 29 infants developed CLD. The CLD group had significantly lower gestation (mean ± SD: 26.6 ± 1.8 weeks) compared with the infants without CLD (28.9 ± 1.9 weeks, P < 0.0001). Logistic analysis showed that the development of CLD was associated with gestational age (odds ratio [OR], 0.5; 95% confidence interval (CI): 0.4-0.8) and Ureaplasma colonization (OR, 4.1; 95%CI: 1.2-14.4). Ureaplasma colonization was also associated with CAM (OR, 6.5; 95%CI: 1.8-23.5), absence of respiratory distress syndrome (OR, 6.2; 95%CI: 1.3-30.5), and development of CLD (OR, 4.0; 95%CI: 1.1-15.3). Elevated cord blood IL-8 ≥100 pg/mL was associated with female sex and the isolation of microorganisms (OR, 49.4; 95%CI: 4.6-525).

CONCLUSION

The development of CLD defined by oxygen requirement at 36 weeks was associated with neonatal Ureaplasma colonization but not with IL-8 level of cord blood. Elevated cord blood IL-8 was associated with neonatal microorganisms isolation.

Selectively high levels of serum interleukin 17 in a newborn infant with progressive severe cholestasis

We present here the unusual case of a male newborn infant who showed progressive severe cholestasis. The infant's gestational age was 37 weeks, and his birth weight was 2134 g. His serum level of direct bilirubin gradually increased from the 6th day of life and reached 257.5 micromol/L on the 22nd day of life. We could not find any cause for his cholestasis, but his serum level of ferritin was extremely elevated at 9211.0 ng/mL. Because we felt that his clinical condition might be related to hypercytokinemia caused by an immunologic reaction, steroid pulse therapy and cyclosporine were administered. His condition improved, and his direct bilirubin and ferritin levels declined. From the investigation of his cytokine profile, we found a preferentially elevated level of serum interleukin 17 (IL-17) (96.1 pg/mL) and high level of chemokines IL-8 and macrophage inflammatory protein 1beta. The IL-17 level gradually decreased to 7.5 pg/mL by the 124th day of life. The infant was successfully discharged from the children's hospital but later developed epilepsy at 11 months and asthma at 1 year, 2 months of age. Although we have not yet reached a definitive diagnosis, this case may be the first to show a relationship between cholestasis and an elevated serum IL-17 level in the neonatal period.

Autism spectrum disorder is related to endoplasmic reticulum stress induced by mutations in the synaptic cell adhesion molecule, CADM1

Autism spectrum disorder (ASD) is a neurodevelopmental disorder with an unknown molecular pathogenesis. A recent molecular focus has been the mutated neuroligin 3, neuroligin 3(R451C), in gain-of-function studies and for its role in induced impairment of synaptic function, but endoplasmic reticulum (ER) stress induced by mutated molecules also deserves investigation. We previously found two missense mutations, H246N and Y251S, in the gene-encoding synaptic cell adhesion molecule-1 (CADM1) in ASD patients, including cleavage of the mutated CADM1 and its intracellular accumulation. In this study, we found that the mutated CADM1 showed slightly reduced homophilic interactions in vitro but that most of its interactions persist. The mutated CADM1 also showed morphological abnormalities, including shorter dendrites, and impaired synaptogenesis in neurons. Wild-type CADM1 was partly localized to the ER of C2C5 cells, whereas mutated CADM1 mainly accumulated in the ER despite different sensitivities toward 4-phenyl butyric acid with chemical chaperone activity and rapamycin with promotion activity for degradation of the aggregated protein. Modeling analysis suggested a direct relationship between the mutations and the conformation alteration. Both mutated CADM1 and neuroligin 3(R451C) induced upregulation of C/EBP-homologous protein (CHOP), an ER stress marker, suggesting that in addition to the trafficking impairment, this CHOP upregulation may also be involved in ASD pathogenesis.

Impairment of social and emotional behaviors in Cadm1-knockout mice

Cell adhesion molecule 1 (CADM1), a member of the immunoglobulin superfamily, mediates synaptic cell adhesion. Missense mutations in the CADM1 gene have been identified in autism spectrum disorder (ASD) patients. In the present study, we examined emotional behaviors, social behaviors and motor performances in Cadm1-knockout (KO) mice. Cadm1-KO mice showed increased anxiety-related behavior in open-field and light-dark transition tests. Social behaviors of Cadm1-KO mice were impaired in social interaction, resident-intruder and social memory/recognition tests. Furthermore, motor coordination and gait of Cadm1-KO mice were impaired in rotarod and footprint tests. Our study demonstrates that CADM1 plays roles in regulating emotional behaviors, social behaviors and motor performances, and that CADM1 has important implications for psychiatric disorders with disruptions in social behavior, such as autism.

Various types of LRP5 mutations in four patients with osteoporosis-pseudoglioma syndrome: identification of a 7.2-kb microdeletion using oligonucleotide tiling microarray

Osteoporosis-pseudoglioma syndrome (OPS; OMIM 259770) is an autosomal-recessive genetic disorder characterized by severe osteoporosis and visual disturbance from childhood. Biallelic mutations in the low-density lipoprotein receptor-related protein 5 gene (LRP5) have been frequently detected, while a subset of patients had only one or no detectable mutation. We report on the clinical and molecular findings of four unrelated Japanese patients with the syndrome. The four patients had typical skeletal and ocular phenotypes of OPS, namely severe juvenile osteoporosis and early-onset visual disturbance, with or without mental retardation. We undertook standard PCR-based sequencing for LRP5 and found four missense mutations (p.L145F, p.T244M, p.P382L, and p.T552M), one nonsense mutation (p.R1534X), and one splice site mutation (c.1584+1G>A) among four OPS patients. Although three patients had two heterozygous mutations, one had only one heterozygous splice site mutation. In this patient, RT-PCR from lymphocytic RNA demonstrated splice error resulting in 63-bp insertion between exons 7 and 8. Furthermore, the patient was found to have only mutated RT-PCR fragment, implying that a seemingly normal allele did not express LRP5 mRNA. We then conducted custom- designed oligonucleotide tiling microarray analyses targeted to a 600-kb genome region harboring LRP5 and discovered a 7.2-kb microdeletion encompassing exons 22 and 23 of LRP5. We found various types of LRP5 mutations, including an exon-level deletion that is undetectable by standard PCR-based mutation screening. Oligonucleotide tiling microarray seems to be a powerful tool in identifying cryptic structural mutations.

Prolonged maternal magnesium administration and bone metabolism in neonates

BACKGROUND

Magnesium sulfate (MgSO(4)) has been used as a tocolytic agent in cases of refractory preterm labor. Prolonged maternal administration of MgSO(4) may induce bone demineralization in the neonate. However, the effects of MgSO(4) on serum biochemistry related to bone metabolism in neonates remain unclear.

AIM

To assess the effects of prolonged maternal administration of MgSO(4) on fetuses and neonates.

STUDY DESIGN

This retrospective case-control study examined 167 neonates. Cases comprised 58 neonates whose mothers had received intravenous MgSO(4) administration for >5 days. Neonatal serum levels of magnesium (Mg), calcium (Ca), phosphorus (P) and alkaline phosphatase (ALP) were reviewed. We also investigated whether subject neonates showed appearance of osteopenia at the metaphyseal lines on radiography at birth.

RESULTS

Mean serum Mg and P levels were significantly higher, and Ca levels were significantly lower, in cases than in controls at birth. Mean serum ALP level was 1188.5IU/l in cases, significantly higher than that in controls at birth. Bone abnormalities were noted on radiography in 2 subjects. By 3 weeks old, serum ALP levels did not differ significantly between cases and controls. Logistic regression analysis revealed maternal administration of MgSO(4) and multiple pregnancies were significantly related to serum ALP level in neonates at birth.

CONCLUSION

Prolonged maternal administration of MgSO(4) significantly affects neonatal serum biochemistry related to bone metabolism. Potential long-term adverse effects on neonates and how Mg affects fetal bone metabolism in utero need to be investigated in future studies.

Unilaterally and rapidly progressing white matter lesion and elevated cytokines in a patient with Tay-Sachs disease

We report the case of a girl with Tay-Sachs disease who had convulsions and deteriorated rapidly after an upper respiratory infection at the age of 11 months. At the age of 16 months, her seizures became intractable and magnetic resonance imaging of the brain showed high signal intensity on T2-weighted images and marked swelling in the white matter and basal nucelei of the right hemisphere. Her seizures and right hemisphere lesion improved with glycerol and dexamethasone treatment. When dexamethasone was discontinued, her symptoms worsened and lesions later appeared in the left hemisphere. Her cerebrospinal fluid showed elevated levels of the cytokines TNF-alpha and IL-5. It is considered that inflammation contributes to disease progression in Tay-Sachs disease.

Grown-up Kawasaki disease patients who have giant coronary aneurysms

BACKGROUND

Many Kawasaki disease (KD) patients have reached adulthood in Japan. The current status of adult patients who have giant coronary aneurysms with KD is not well understood.

METHODS

Medical records of 48 KD patients (33 males and 15 females) with giant coronary aneurysms (maximum coronary artery internal diameter >8 mm) aged 20 years or over were retrospectively reviewed.

RESULTS

The age of the patients at the diagnosis of KD ranged from 0.3 to 12.8 years (median 2.9 years) and the age of the patients in this review ranged from 20.0 to 33.1 years (median 25.2 years). During the follow-up period, the maximum coronary artery internal diameter ranged from 8.2 to 30.0 mm (median 10 mm). Giant coronary aneurysms progressed to coronary artery stenosis and/or complete occlusion in 34 (74%) of 46 patients. Coronary artery bypass graft surgery was performed in 9 (19%) of 48 patients. Myocardial infarction occurred in 14 (31%) of 45 patients. Other complications or problems occurred in 5 patients with angina pectoris, low left ventricular ejection fraction, ventricular tachycardia, hemorrhagic cerebral infarction, or thyroid carcinoma respectively. In the patients followed up, 4 dropped out. In addition, 1 patient succeeded in pregnancy and delivered a baby.

CONCLUSIONS

Close attention should be paid to ventricular tachycardia in adult KD patients with giant coronary aneurysms, especially for those who have low left ventricular ejection fraction. To reduce the number of dropped out patients, it is important that the patients should be referred to a new doctor when they change their place of residence.

Expression analysis and mutation detection of DLX5 and DLX6 in autism

Linkage analysis has reported the chromosomal region 7q21 to be related with autism. This region contains an imprinting region with MECP2-binding sites, and DLX5 is reported to be modulated by MECP2. DLX5 and adjacent DLX6 are homeobox genes working in neurogenesis. From these points, DLX5 and DLX6 are candidate genes for autism. Therefore, we analyzed the expression of DLX5 and DLX6, and also PEG10 as a control in the lymphoblasts of autistic spectrum disorder (ASD) patients by real-time PCR to identify potential abnormality of expression. And we also analyzed DLX5 and DLX6 on ASD patients for mutation by direct sequence. The expression level of DLX5 was not different between ASD and controls but was higher in four ASD patients compared to controls. Clinical features of these four patients were variable. DLX5 expression was biallelic in two ASD patients and two controls, indicating that DLX5 was not imprinted. There was no mutation in DLX5 in ASD. Although DLX5 was not likely to play major role in ASD, genes relating to DLX5 expression and downstream of DLX5 are considered to be candidate genes for some of the ASD patients. In DLX6, we detected a G656A base change (R219H) in two ASD patients who were male siblings. DLX6 may contribute to the pathogenesis of ASD.

Change of specific T cells in an emerging neonatal infectious disease induced by a bacterial superantigen

A new epidemic, NTED, has recently occurred in Japan. The cause of NTED is a bacterial superantigen, TSST-1. The aim of the present study was to analyze the change in Vbeta2(+) T cells reactive to TSST-1 in NTED in order to establish T-cell-targeted diagnostic criteria for NTED. Blood samples from 75 patients with clinically diagnosed NTED were collected from 13 neonatal intensive care units throughout Japan. We investigated the percentages of Vbeta2(+), Vbeta3(+) and Vbeta12(+) T cells and their CD45RO expressions in the samples using flow cytometry. In 18 of the 75 patients, we conducted multiple examinations of the T cells and monitored serial changes. The Vbeta2(+) T-cell population rapidly changed over three phases of the disease. Whereas the percentage of Vbeta2(+) T cells was widely distributed over the entire control range, CD45RO expression on Vbeta2(+) T cells in CD4(+) in all 75 patients was consistently higher than the control range. Patients cannot necessarily be diagnosed as having NTED based on expansion of Vbeta2(+) T cells alone in the early acute phase. Instead, CD45RO expression on specific Vbeta2(+) cells is a potential diagnostic marker for a rapid diagnosis of NTED. We present three diagnostic categories of NTED. Fifty patients (66.7%) were included in the category 'definitive NTED'. It is important to demonstrate an increase of Vbeta2(+) T cells in the following phase in cases of 'probable NTED' or 'possible NTED'.

Macrophage inflammatory protein-1beta and interleukin-8 associated with idiopathic steroid-sensitive nephrotic syndrome

BACKGROUND

The cytokines associated with idiopathic steroid-sensitive nephrotic syndrome (ISSNS) have not been identified definitively, because previous studies had variable sampling and population heterogeneity. To clarify the cytokines involved, serum cytokine levels were measured using uniform sampling in a homogeneous population.

METHODS

Five children meeting the following criteria were included: (i) ISSNS; (ii) selectivity index <0.1; (iii) paired sera obtained in the nephrotic phase before steroid treatment (STx; group A) and in the remission phase under STx (group B); (iv) no infection; and (v) no immunosuppressant. Control groups were as follows: group C, four children with ISSNS in the remission phase without STx; group D, five with normal urinalysis; group E, five with symptomatic secondary nephrotic syndrome before STx. Cytokine levels were measured using bead-based assay.

RESULTS

Serum macrophage inflammatory protein-1beta (MIP-1beta) levels were higher in group B compared to group A, and group C was lower than groups A and B. Serum interleukin-8 (IL-8) levels were higher in group A than in groups B and C, and groups B and C did not differ. With regard to both cytokine levels, there were no differences between groups C and D, and groups A and E.

CONCLUSION

Serum MIP-1beta and IL-8 are associated with the clinical status of ISSNS in children. A relationship between MIP-1beta and ISSNS has not been previously reported. The mechanism by which MIP-1beta and IL-8 affect ISSNS is unclear. Nevertheless, the present findings are an interesting starting point for further investigations into the pathophysiology of ISSNS in children.

A case of meningoencephalitis associated with G1P[8] rotavirus infection in a Japanese child

We report the case of a 2-y, 11-month-old boy with G1P[8] rotavirus infection accompanied by acute meningoencephalitis. Substitutions in both the VP4 and VP7 genes were found in the identified strain. A commonly circulating G1P[8] rotavirus with such mutations might be associated with the pathogenesis of CNS complications, including meningoencephalitis.

Mutations in the gene encoding CADM1 are associated with autism spectrum disorder

The unified idea on the molecular pathogenesis of Autism Spectrum Disorder (ASD) is still unknown although mutations in genes encoding neuroligins and SHANK3 have been shown in a small part of the patients. RA175/SynCAM1/CADM1(CADM1), a member of immunoglobulin superfamily, is another synaptic cell adhesion molecule. To clarify the idea that impaired synaptogenesis underlies the pathogenesis of ASD, we examined the relationship between mutations in the CADM1 gene and ASD. We found two missense mutations, C739A(H246N) and A755C(Y251S), in the CADM1 gene of male Caucasian ASD patients and their family members. Both mutations were located in the third immunoglobulin domain, which is essential for trans-active interaction. The mutated CADM1 exhibited less amount of high molecular weight with the matured oligosaccharide, defective trafficking to the cell surface, and more susceptibility to the cleavage and or degradation. Our findings provide key support for the unified idea that impaired synaptogenesis underlies the pathogenesis of ASD.