1Front Cell Neurosci 2013 -1 7: 61
PMID23675315
TitleImpact of structural aberrancy of polysialic acid and its synthetic enzyme ST8SIA2 in schizophrenia.
AbstractPsychiatric disorders are a group of human diseases that impair higher cognitive functions. Whole-genomic analyses have recently identified susceptibility genes for several psychiatric disorders, including schizophrenia. Among the genes reported to be involved in psychiatric disorders, a gene encoding a polysialyltransferase involved in the biosynthesis of polysialic acid (polySia or PSA) on cell surfaces has attracted attention for its potential role in emotion, learning, memory, circadian rhythm, and behaviors. PolySia is a unique polymer that spatio-temporally modifies neural cell adhesion molecule (NCAM) and is predominantly found in embryonic brains, although it persists in areas of the adult brain where neural plasticity, remodeling of neural connections, or neural generation is ongoing, such as the hippocampus, subventricular zone (SVZ), thalamus, prefrontal cortex, and amygdala. PolySia is thought to be involved in the regulation of cell-cell interactions; however, recent evidence suggests that it is also involved in the functional regulation of ion channels and neurologically active molecules, such as Brain-derived neurotrophic factor (BDNF), FGF2, and dopamine (DA) that are deeply involved in psychiatric disorders. In this review, the possible involvement of polysialyltransferase (ST8SIA2/ST8SiaII/STX/Siat8B) and its enzymatic product, polySia, in schizophrenia is discussed.
SCZ Keywordsschizophrenia
2Psychoneuroendocrinology 2013 Apr 38: 509-21
PMID22910687
TitlePrenatal stress delays inhibitory neuron progenitor migration in the developing neocortex.
AbstractPrenatal stress has been widely demonstrated to have links with behavioral problems in clinical populations and animal models, however, few investigations have examined the immediate developmental events that are affected by prenatal stress. Here, we utilize GAD67GFP transgenic mice in which GABAergic progenitors express green fluorescent protein (GFP) to examine the impact of prenatal stress on the development of these precursors to inhibitory neurons. Pregnant female mice were exposed to restraint stress three times daily from embryonic day 12 (E12) onwards. Their offspring demonstrated changes in the distribution of GFP-positive (GFP+) GABAergic progenitors in the telencephalon as early as E13 and persisting until postnatal day 0. Changes in distribution reflected alterations in tangential migration and radial integration of GFP+ cells into the developing cortical plate. Fate mapping of GAD67GFP+ progenitors with bromodeoxyuridine injected at E13 demonstrated a significant increase of these cells at P0 in anterior white matter. An overall decrease in GAD67GFP+ progenitors at P0 in medial frontal cortex could not be attributed to a reduction in cell proliferation. Significant changes in dlx2, nkx2.1 and their downstream target erbb4, transcription factors which regulate interneuron migration, were found within the prenatally stressed developing forebrain, while no differences were seen in mash1, a determinant of interneuron fate, bdnf, a maturation factor for GABAergic cells or FGF2, an early growth/differentiation factor. These results demonstrate that early disruption in GABAergic progenitor migration caused by prenatal stress may be responsible for neuronal defects in disorders with GABAergic abnormalities like schizophrenia.
SCZ Keywordsschizophrenia
3Schizophr Bull 2013 Jul 39: 848-56
PMID22532702
TitleIntermediate phenotype analysis of patients, unaffected siblings, and healthy controls identifies VMAT2 as a candidate gene for psychotic disorder and neurocognition.
AbstractPsychotic disorders are associated with neurocognitive alterations that aggregate in unaffected family members, suggesting that genetic vulnerability to psychotic disorder impacts neurocognition. The aim of the present study was to investigate whether selected schizophrenia candidate single nucleotide polymorphisms (SNPs) are associated with (1) neurocognitive functioning across populations at different genetic risk for psychosis (2) and psychotic disorder. The association between 152 SNPs in 43 candidate genes and a composite measure of neurocognitive functioning was examined in 718 patients with psychotic disorder. Follow-up analyses were carried out in 750 unaffected siblings and 389 healthy comparison subjects. In the patients, 13 associations between SNPs and cognitive functioning were significant at P < .05, situated in DRD1, DRD3, SLC6A3, BDNF, FGF2, SLC18A2, FKBP5, and DNMT3B. Follow-up of these SNPs revealed a significant and directionally similar association for SLC18A2 (alternatively VMAT2) rs363227 in siblings (B = -0.13, P = .04) and a trend association in control subjects (B = -0.10, P = .12). This association was accompanied by a significantly increased risk for psychotic disorder associated with the T allele (linear OR = 1.51, 95% CI 1.10-2.07, P = .01), which was reduced when covarying for cognitive performance (OR = 1.29, 95% CI 0.92-1.81, P = .14), suggesting mediation. Genetic variation in VMAT2 may be linked to alterations in cognitive functioning underlying psychotic disorder, possibly through altered transport of monoamines into synaptic vesicles.
SCZ Keywordsschizophrenia
4Neuroscientist 2013 Oct 19: 479-94
PMID23343917
TitleFibroblast growth factors in neurodevelopment and psychopathology.
AbstractIn psychiatric disorders, the effect of genetic and environmental factors may converge on molecular pathways and brain circuits related to growth factor functioning. In this review, we describe how disturbances in fibroblast growth factors (FGFs) and their receptors influence behavior by affecting brain development. Recently, several studies reported associations of members of the FGF family with psychiatric disorders. FGFs are key candidates to modulate the impact of environmental factors, such as stress. Mutant mice for FGF receptor 1 show schizophrenia-like behaviors that are related to general loss of neurons and postnatal glia dysfunction. Mice lacking FGF2, a FGFR1 ligand, show similar reductions in brain volume and hyperactivity, as well as increased anxiety behaviors. FGFR2 and FGF17 are involved in the development of frontal brain regions and impairments in cognitive and social behaviors, respectively. Moreover, treatment with FGF2 was beneficial for depressive and cognitive measures in several animal studies and one human study. These findings indicate the importance of the FGF system with respect to developing novel etiology-directed treatments for psychopathology.
SCZ Keywordsschizophrenia
5Ross Fiziol Zh Im I M Sechenova 2014 Sep 100: 1025-37
PMID25697011
Title[The administration of interleukin-1beta during early postnatal develop ment impairs FGF2, but not TIMP1, mRNA expression in brain structures of adult rats].
AbstractAccording to the Neurodevelopmental hypothesis, the long-lasting cognitive deficit in schizophrenia and other types of neuropathology may occur by injurious factors, such as hypoxia, traumas, infections that take place during pre- and postnatal development, at least at early stages. These pathological conditions are often associated with the high production of pro-inflammatory cytokine interleukin-1B (IL-1B) by the cells of immune and nervous systems. We investigated the expression of genes involved in the neuroplastic regulation (FGF2 and Timp2) in medial prefrontal cortex and dorsal and ventral regions of hippocampus of adult rats that were treated with IL-1beta between P15 and P21. The learning impairment in IL-1beta-treated rats is accompanied by lower FGF-2 mRNA levels in medial prefrontal cortex and ventral (not dorsal) hippocampus, but TIMP-1 was not affected. No differences in TIMP-1 and FGF-2 mRNA expressions were observed in untrained IL-1beta-treated when compared to control rats.
SCZ Keywordsschizophrenia
6Glycobiology 2015 Oct 25: 1112-24
PMID26163659
TitleProtective effects of polysialic acid on proteolytic cleavage of FGF2 and proBDNF/BDNF.
AbstractPolysialic acid (polySia) is a linear polymer of sialic acid that modifies neural cell adhesion molecule (NCAM) in the vertebrate brain. PolySia is a large and exclusive molecule that functions as a negative regulator of cell-cell interactions. Recently, we demonstrated that polySia can specifically bind fibroblast growth factor 2 (FGF2) and BDNF; however, the protective effects of polySia on the proteolytic cleavage of these proteins remain unknown, although heparin/heparan sulfate has been shown to impair the cleavage of FGF2 by trypsin. Here, we analyzed the protective effects of polySia on the proteolytic cleavage of FGF2 and proBDNF/BDNF. We found that polySia protected intact FGF2 from tryptic activity via the specific binding of extended polySia chains on NCAM to FGF2. Oligo/polySia also functioned to impair the processing of proBDNF by plasmin via binding of oligo/polySia chains on NCAM. In addition, the polySia structure synthesized by mutated polysialyltransferase, ST8SIA2/STX(SNP7), which was previously identified from a schizophrenia patient, was impaired for these functions compared with polySia produced by normal ST8SIA2. Taken together, these data suggest that the protective effects of polySia toward FGF2 and proBDNF may be involved in the regulation of the concentrations of these neurologically active molecules.
SCZ Keywordsschizophrenia