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).

CASPR2 forms a complex with GPR37 via MUPP1 but not with GPR37(R558Q), an autism spectrum disorder-related mutation.

Autism spectrum disorder (ASD) is a developmental brain disorder. Mutations in synaptic components including synaptic adhesion molecules have been found in ASD patients. Contactin-associated protein-like 2 (CASPR2) is one of the synaptic adhesion molecules associated with ASD. CASPR2 forms a complex with receptors via interaction with multiple PDZ domain protein 1 (MUPP1). Little is known about the relationship between impaired CASPR2-MUPP1-receptor complex and the pathogenesis of ASD. GPR37 is a receptor for survival factors. We recently identified mutations including R558Q in the G-protein-coupled receptor 37 (GPR37) gene in ASD patients. The mutated GPR37s accumulate in the endoplasmic reticulum. In this study, we show that GPR37 is a component of the CASPR2-MUPP1 receptor complex in the mouse brain. CASPR2 and GPR37 mainly interacted with the PDZ3 and PDZ11 domains of MUPP1, respectively. Compared to GPR37, GPR37(R558Q) slightly interacted with MUPP1 and caused dendritic alteration. GPR37, but not GPR37(R558Q) nor GPR37-deltaC which lacks its PDZ binding domain, was transported to the cell surface by MUPP1. In primary hippocampal neurons, GPR37 co-localized with MUPP1 and CASPR2 at the synapse, but not GPR37(R558Q). Thus, ASD-related mutation of GPR37 may cause the impaired CASPR2-MUPP1-GPR37 complex on the dendrites associated with one of the pathogenesis of ASD. In this study, we identified that GPR37 is a component of the MUPP1 and CASPR2 receptor complex. Autism deleterious mutated GPR37(R558Q) slightly interacts with MUPP1 and retains in ER, resulting in dendritic alteration. In neuron, GPR37, but not GPR37(R558Q), is transported to the dendrite and synapse by MUPP1. Thus, ASD-related mutation of GPR37 may cause the impaired CASPR2-MUPP1-GPR37 complex on the dendrites associated with one of the pathogenesis of ASD.

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.

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.

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.

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.

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.

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.

Monitoring of anti-L-asparaginase antibody and L-asparaginase activity levels in a pediatric patient with acute lymphoblastic leukemia and hypersensitivity to native Escherichia coli L-asparaginase during desensitization courses.

A patient with acute lymphoblastic leukemia who was hypersensitive to native Escherichia coli L-asparaginase (L-asp) underwent readministration of the L-asp without serious adverse effects for 11 doses using a desensitization protocol every time. Monitoring of anti-L-asp antibody and L-asp activity levels revealed that the serum L-asp activity was below the effective levels during the administration of first 6 to 7 doses because of extremely high levels of anti-L-asp IgG. Sustained L-asp activity was attained since the eighth dose was administered, when the antibody levels were <5 U/mL. L-asp activity levels in patients with L-asp hypersensitivity should be monitored during the desensitization courses to ensure a sufficient L-asp activity.

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.

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.

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.

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.

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.

An Xp22.12 microduplication including RPS6KA3 identified in a family with variably affected intellectual and behavioral disabilities.

The ribosomal protein S6 kinase, 90 kb, polypeptide 3 gene (RPS6KA3) is responsible for Coffin-Lowry syndrome (CLS), which is characterized by intellectual disability (ID) and facial and bony abnormalities. This gene also affects nonsyndromic X-linked ID and nonsyndromic X-linked ID without bony abnormalities. Two families have been previously reported to have genetic microduplication including RPS6KA3. In the present study, we used array-comparative genomic hybridization (CGH) analysis with Agilent Human genome CGH 180K and detected a 584-kb microduplication spanning 19.92-20.50 Mb of Xp22.12 (including RPS6KA3) in the members of one family, including three brothers, two sisters, and their mother. The 15-year-old male proband and one of his brothers had mild ID and localization-related epilepsy, whereas his other brother presented borderline intelligence quotient (IQ) and attention-deficit-hyperactivity disorder (ADHD). One sister presented pervasive development disorder (PDD). Analysis of this family suggests that RPS6KA3 duplication is responsible for mild ID, ADHD, and localization-related epilepsy, and possibly for PDD.

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.