RESUMO
The present study describes the hair growth-promoting effects of sodium thiosulfate (STS), a widely used compound, in mice. STS accelerated hair growth in the "telogen model", suggesting that it stimulates telogen hair follicles to reenter the anagen phase of hair growth. In the same model, STS potentiated hair growth in an additive manner with minoxidil (MXD), a drug used for the treatment of androgenic alopecia. Furthermore, in the "anagen model", STS promoted hair growth, probably by promoting hair follicle proliferation. Since STS elevated the skin surface temperature, its hair growth-promoting activity may be partly due to vasorelaxation, similar to MXD. In addition, STS is known to generate a gaseous mediator, H2S, which has vasorelaxation and anti-inflammatory/anti-oxidative stress activities. Therefore, STS and/or provisionally its metabolite, H2S, may aid the hair growth process. Collectively, these results suggest that salts of thiosulfate may represent a novel and beneficial remedy for hair loss.
Assuntos
Folículo Piloso/efeitos dos fármacos , Folículo Piloso/crescimento & desenvolvimento , Modelos Animais , Tiossulfatos/farmacologia , Alopecia/tratamento farmacológico , Animais , Sinergismo Farmacológico , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Camundongos Endogâmicos C3H , Minoxidil/administração & dosagem , Minoxidil/efeitos adversos , Minoxidil/farmacologia , Modelos Biológicos , Temperatura Cutânea/efeitos dos fármacos , Sulfurtransferases/genética , Sulfurtransferases/metabolismo , Tiossulfatos/administração & dosagem , Tiossulfatos/efeitos adversosRESUMO
BACKGROUND: Genes responsible for reduced pigmentation phenotypes in rodents are associated with human developmental defects, such as Waardenburg syndrome, where patients display congenital deafness along with various abnormalities mostly related to neural crest development deficiency. OBJECTIVE: In this study, we identified a spontaneous mutant mouse line Rwa, which displays variable white spots on mouse bellies and white digits and tail, on a C57BL/6N genetic background. Curly tail and spina bifida were also observed, although at a lower penetrance. These phenotypes were dominantly inherited by offspring. We searched for the genetic mechanism of the observed phenotypes. METHODS: We harnessed a rapid mouse gene mapping system newly developed in our laboratories to identify a responsible gene. RESULTS: We detected a region within chromosome 1 as a probable locus for the causal mutation. Dense mapping using interval markers narrowed the locus down to a 670-kbp region, containing four genes including Pax3, a gene known to be implicated in the types I and III Waardenburg syndrome. Extensive mutation screening of Pax3 detected an 841-bp deletion, spanning the promoter region and intron 1 of the gene. The defective allele of Pax3, named Pax3Rwa, lacked the first coding exon and co-segregated perfectly with the phenotypes, confirming its causal nature. The genetic background of Rwa mice is almost identical to that of inbred C57BL/6N. CONCLUSION: These results highlight Pax3Rwa mice as a beneficial tool for analyzing biological processes involving Pax3, in particular the development and migration of neural crest cells and melanocytes.
Assuntos
Modelos Animais de Doenças , Defeitos do Tubo Neural/genética , Fator de Transcrição PAX3/genética , Síndrome de Waardenburg/genética , Animais , Éxons , Feminino , Masculino , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Defeitos do Tubo Neural/etiologia , Síndrome de Waardenburg/etiologiaRESUMO
Involvement of the gamma-aminobutyric acid (GABA)-ergic system in schizophrenia pathogenesis through disrupted neurodevelopment has been highlighted in numerous studies. However, the function of common genetic variants of this system in determining schizophrenia risk is unknown. We therefore tested the association of 375 tagged SNPs in genes derived from the GABAergic system, such as GABAA receptor subunit genes, and GABA related genes (glutamate decarboxylase genes, GABAergic-marker gene, genes involved in GABA receptor trafficking and scaffolding) in Japanese schizophrenia case-control samples (n=2926; 1415 cases and 1511 controls). We observed nominal association of SNPs in nine GABAA receptor subunit genes and the GPHN gene with schizophrenia, although none survived correction for study-wide multiple testing. Two SNPs located in the GABRA1 gene, rs4263535 (Pallele=0.002; uncorrected) and rs1157122 (Pallele=0.006; uncorrected) showed top hits, followed by rs723432 (Pallele=0.007; uncorrected) in the GPHN gene. All three were significantly associated with schizophrenia and survived gene-wide multiple testing. Haplotypes containing associated variants in GABRA1 but not GPHN were significantly associated with schizophrenia. To conclude, we provided substantiating genetic evidence for the involvement of the GABAergic system in schizophrenia susceptibility. These results warrant further investigations to replicate the association of GABRA1 and GPHN with schizophrenia and to discern the precise mechanisms of disease pathophysiology.
Assuntos
Proteínas de Transporte/genética , Predisposição Genética para Doença , Proteínas de Membrana/genética , Polimorfismo de Nucleotídeo Único/genética , Esquizofrenia/genética , Transdução de Sinais/genética , Adulto , Idoso , Povo Asiático , Feminino , Frequência do Gene , Testes Genéticos , Glutamato Descarboxilase/genética , Humanos , Desequilíbrio de Ligação , Masculino , Pessoa de Meia-Idade , Receptores de GABA/genética , Esquizofrenia/metabolismo , Ácido gama-Aminobutírico/genética , Ácido gama-Aminobutírico/metabolismoRESUMO
Fatty acid binding protein 7 (FABP7) expressed by astrocytes in developing and mature brains is involved in uptake and transportation of fatty acids, signal transduction, and gene transcription. Fabp7 knockout (Fabp7 KO) mice show behavioral phenotypes reminiscent of human neuropsychiatric disorders such as schizophrenia. However, direct evidence showing how FABP7 deficiency in astrocytes leads to altered brain function is lacking. Here, we examined neuronal dendritic morphology and synaptic plasticity in medial prefrontal cortex (mPFC) of Fabp7 KO mice and in primary cortical neuronal cultures. Golgi staining of cortical pyramidal neurons in Fabp7 KO mice revealed aberrant dendritic morphology and decreased spine density compared with those in wild-type (WT) mice. Aberrant dendritic morphology was also observed in primary cortical neurons co-cultured with FABP7-deficient astrocytes and neurons cultured in Fabp7 KO astrocyte-conditioned medium. Excitatory synapse number was decreased in mPFC of Fabp7 KO mice and in neurons co-cultured with Fabp7 KO astrocytes. Accordingly, whole-cell voltage-clamp recording in brain slices from pyramidal cells in the mPFC showed that both amplitude and frequency of action potential-independent miniature excitatory postsynaptic currents (mEPSCs) were decreased in Fabp7 KO mice. Moreover, transplantation of WT astrocytes into the mPFC of Fabp7 KO mice partially attenuated behavioral impairments. Collectively, these results suggest that astrocytic FABP7 is important for dendritic arbor growth, neuronal excitatory synapse formation, and synaptic transmission, and provide new insights linking FABP7, lipid homeostasis, and neuropsychiatric disorders, leading to novel therapeutic interventions.
Assuntos
Astrócitos/fisiologia , Dendritos/fisiologia , Proteínas de Ligação a Ácido Graxo/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Córtex Pré-Frontal/fisiologia , Células Piramidais/fisiologia , Sinapses/fisiologia , Animais , Astrócitos/transplante , Técnicas de Cocultura , Potenciais Pós-Sinápticos Excitadores/fisiologia , Proteína 7 de Ligação a Ácidos Graxos , Proteínas de Ligação a Ácido Graxo/genética , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Potenciais Pós-Sinápticos em Miniatura/fisiologia , Atividade Motora/fisiologia , Proteínas do Tecido Nervoso/genética , Córtex Pré-Frontal/citologia , Córtex Pré-Frontal/cirurgia , Células Piramidais/citologiaRESUMO
The solute carrier 27A (SLC27A) gene family encodes fatty acid transport proteins (FATPs) and includes 6 members. During fetal and postnatal periods of development, the growing brain requires a reliable supply of fatty acids. Because autism spectrum disorders (ASD) are now recognized as disorders caused by impaired early brain development, it is possible that functional abnormalities of SLC27A genes may contribute to the pathogenesis of ASD. Here, we confirmed the expression of SLC27A3 and SLC27A4 in human neural stem cells derived from human induced pluripotent stem cells, which suggested their involvement in the developmental stage of the central nervous system. Additionally, we resequenced the SLC27A3 and SLC27A4 genes using 267 ASD patient and 1140 control samples and detected 47 (44 novel and 29 nonsynonymous) and 30 (17 novel and 14 nonsynonymous) variants for the SLC27A3 and SLC27A4, respectively, revealing that they are highly polymorphic with multiple rare variants. The SLC27A4 Ser209 allele was more frequently represented in ASD samples. Furthermore, we showed that a SLC27A4 Ser209 mutant resulted in significantly higher fluorescently-labeled fatty acid uptake into bEnd3 cells, a mouse brain capillary-derived endothelial cell line, compared with SLC27A4 Gly209, suggesting that the functional change may contribute to ASD pathophysiology.
Assuntos
Transtorno do Espectro Autista/genética , Proteínas de Transporte de Ácido Graxo/genética , Ácidos Graxos/metabolismo , Estudos de Associação Genética , Sequência de Aminoácidos/genética , Animais , Transtorno do Espectro Autista/metabolismo , Transtorno do Espectro Autista/patologia , Encéfalo/crescimento & desenvolvimento , Encéfalo/metabolismo , Proteínas de Transporte de Ácido Graxo/biossíntese , Ácidos Graxos/genética , Feminino , Humanos , Masculino , Camundongos , Mutação , Células-Tronco Neurais/metabolismo , Conformação Proteica , Análise de Sequência de DNARESUMO
Disruption of synaptic networks has been advocated in the pathogenesis of psychiatric diseases like schizophrenia. The majority of synaptic proteins involved in neuronal communications are localized in lipid rafts. These rafts form the platform for coordinating neuronal signal transduction, by clustering interacting partners. The PAG1 protein is a transmembrane adaptor protein in the lipid raft signaling cluster that regulates Src family kinases (SFKs), a convergent point for multiple pathways regulating N-methyl-D-aspartate (NMDA) receptors. Reports of de novo missense mutations in PAG1 and SFK mediated reductions in tyrosine phosphorylation of NMDA receptor subunit proteins in schizophrenia patients, point to a putative role in schizophrenia pathogenesis. To evaluate this, we resequenced the entire coding region of PAG1 in Japanese schizophrenia patients (n = 1,140) and controls (n = 1,140). We identified eight missense variants, of which four were previously unreported. Case-control genetic association analysis of these variants in a larger cohort (n = 4,182) showed neither a statistically significant association of the individual variants with schizophrenia, nor any increased burden of the rare alleles in the patient group. Expression levels of PAG1 in post-mortem brain samples from schizophrenia patients and controls also showed no significant differences. To assess the precise role of PAG1 in schizophrenia, future studies with larger sample sizes are needed.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Encéfalo/metabolismo , Regulação da Expressão Gênica/genética , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Mutação de Sentido Incorreto/genética , Esquizofrenia , Adulto , Idoso , Estudos de Casos e Controles , Estudos de Coortes , Éxons/genética , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Haplótipos , Humanos , Japão , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/metabolismo , Esquizofrenia/genética , Esquizofrenia/metabolismo , Esquizofrenia/patologiaRESUMO
BACKGROUND: Identifying beneficial surrogate genetic markers in psychiatric disorders is crucial but challenging. METHODS: Given that scalp hair follicles are easily accessible and, like the brain, are derived from the ectoderm, expressions of messenger RNA (mRNA) and microRNA in the organ were examined between schizophrenia (n for first/second = 52/42) and control subjects (n = 62/55) in two sets of cohort. Genes of significance were also analyzed using postmortem brains (n for case/control = 35/35 in Brodmann area 46, 20/20 in cornu ammonis 1) and induced pluripotent stem cells (n = 4/4) and pluripotent stem cell-derived neurospheres (n = 12/12) to see their role in the central nervous system. Expression levels of mRNA for autism (n for case/control = 18/24) were also examined using scalp hair follicles. RESULTS: Among mRNA examined, FABP4 was downregulated in schizophrenia subjects by two independent sample sets. Receiver operating characteristic curve analysis determined that the sensitivity and specificity were 71.8% and 66.7%, respectively. FABP4 was expressed from the stage of neurosphere. Additionally, microarray-based microRNA analysis showed a trend of increased expression of hsa-miR-4449 (p = .0634) in hair follicles from schizophrenia. hsa-miR-4449 expression was increased in Brodmann area 46 from schizophrenia (p = .0007). Finally, we tested the expression of nine putative autism candidate genes in hair follicles and found decreased CNTNAP2 expression in the autism cohort. CONCLUSIONS: Scalp hair follicles could be a beneficial genetic biomarker resource for brain diseases, and further studies of FABP4 are merited in schizophrenia pathogenesis.
Assuntos
Biomarcadores/metabolismo , Folículo Piloso , Esquizofrenia/diagnóstico , Esquizofrenia/genética , Adulto , Transtorno Autístico/diagnóstico , Transtorno Autístico/genética , Encéfalo/metabolismo , Proteínas de Ligação a Ácido Graxo/sangue , Proteínas de Ligação a Ácido Graxo/genética , Feminino , Expressão Gênica , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Masculino , Proteínas de Membrana/genética , MicroRNAs/metabolismo , Pessoa de Meia-Idade , Proteínas do Tecido Nervoso/genética , Células-Tronco Neurais/metabolismo , RNA Mensageiro/metabolismo , Couro CabeludoRESUMO
BACKGROUND: Histone H3 methylation at lysine 9 (H3K9) is a conserved epigenetic signal, mediating heterochromatin formation by trimethylation, and transcriptional silencing by dimethylation. Defective GLP (Ehmt1) and G9a (Ehmt2) histone lysine methyltransferases, involved in mono and dimethylation of H3K9, confer autistic phenotypes and behavioral abnormalities in animal models. Moreover, EHMT1 loss of function results in Kleefstra syndrome, characterized by severe intellectual disability, developmental delays and psychiatric disorders. We examined the possible role of histone methyltransferases in the etiology of autism spectrum disorders (ASD) and suggest that rare functional variants in these genes that regulate H3K9 methylation may be associated with ASD. METHODS: Since G9a-GLP-Wiz forms a heteromeric methyltransferase complex, all the protein-coding regions and exon/intron boundaries of EHMT1, EHMT2 and WIZ were sequenced in Japanese ASD subjects. The detected variants were prioritized based on novelty and functionality. The expression levels of these genes were tested in blood cells and postmortem brain samples from ASD and control subjects. Expression of EHMT1 and EHMT2 isoforms were determined by digital PCR. RESULTS: We identified six nonsynonymous variants: three in EHMT1, two in EHMT2 and one in WIZ. Two variants, the EHMT1 ankyrin repeat domain (Lys968Arg) and EHMT2 SET domain (Thr961Ile) variants were present exclusively in cases, but showed no statistically significant association with ASD. The EHMT2 transcript expression was significantly elevated in the peripheral blood cells of ASD when compared with control samples; but not for EHMT1 and WIZ. Gene expression levels of EHMT1, EHMT2 and WIZ in Brodmann area (BA) 9, BA21, BA40 and the dorsal raphe nucleus (DoRN) regions from postmortem brain samples showed no significant changes between ASD and control subjects. Nor did expression levels of EHMT1 and EHMT2 isoforms in the prefrontal cortex differ significantly between ASD and control groups. CONCLUSIONS: We identified two novel rare missense variants in the EHMT1 and EHMT2 genes of ASD patients. We surmise that these variants alone may not be sufficient to exert a significant effect on ASD pathogenesis. The elevated expression of EHMT2 in the peripheral blood cells may support the notion of a restrictive chromatin state in ASD, similar to schizophrenia.
RESUMO
Disturbances of lipid metabolism have been implicated in psychiatric illnesses. We previously reported an association between the gene for fatty acid binding protein 7 (FABP7) and schizophrenia. Furthermore, we identified and reported several rare non-synonymous polymorphisms of the brain-expressed genes FABP3, FABP5 and FABP7 from schizophrenia and autism spectrum disorder (ASD), diseases known to part share genetic architecture. Here, we conducted further studies to better understand the contribution these genes make to the pathogenesis of schizophrenia and ASD. In postmortem brains, we detected altered mRNA expression levels of FABP5 in schizophrenia, and of FABP7 in ASD and altered FABP5 in peripheral lymphocytes. Using a patient cohort, comprehensive mutation screening identified six missense and two frameshift variants from the three FABP genes. The two frameshift proteins, FABP3 E132fs and FABP7 N80fs, formed cellular aggregates and were unstable when expressed in cultured cells. The four missense mutants with predicted possible damaging outcomes showed no changes in intracellular localization. Examining ligand binding properties, FABP7 S86G and FABP7 V126L lost their preference for docosahexaenoic acid to linoleic acid. Finally, mice deficient in Fabp3, Fabp5 and Fabp7 were evaluated in a systematic behavioral test battery. The Fabp3 knockout (KO) mice showed decreased social memory and novelty seeking, and Fabp7 KO mice displayed hyperactive and anxiety-related phenotypes, while Fabp5 KO mice showed no apparent phenotypes. In conclusion, disturbances in brain-expressed FABPs could represent an underlying disease mechanism in a proportion of schizophrenia and ASD sufferers.
Assuntos
Comportamento Animal , Proteínas de Transporte/genética , Transtornos Globais do Desenvolvimento Infantil/genética , Proteínas de Ligação a Ácido Graxo/genética , Esquizofrenia/genética , Proteínas Supressoras de Tumor/genética , Sequência de Aminoácidos , Animais , Ansiedade/genética , Ansiedade/fisiopatologia , Encéfalo/metabolismo , Encéfalo/patologia , Proteínas de Transporte/metabolismo , Transtornos Globais do Desenvolvimento Infantil/metabolismo , Transtornos Globais do Desenvolvimento Infantil/fisiopatologia , Ácidos Docosa-Hexaenoicos/metabolismo , Comportamento Exploratório , Proteína 3 Ligante de Ácido Graxo , Proteína 7 de Ligação a Ácidos Graxos , Proteínas de Ligação a Ácido Graxo/metabolismo , Mutação da Fase de Leitura , Humanos , Ácido Linoleico/metabolismo , Linfócitos/metabolismo , Camundongos , Camundongos Transgênicos , Modelos Moleculares , Dados de Sequência Molecular , Mutação de Sentido Incorreto , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Esquizofrenia/metabolismo , Esquizofrenia/fisiopatologia , Alinhamento de Sequência , Proteínas Supressoras de Tumor/metabolismoRESUMO
Cyclic phosphatidic acid (cPA), an analog of lysophosphatidic acid (LPA), was previously identified in human serum. Although cPA possesses distinct physiological activities not elicited by LPA, its biochemical origins have scarcely been studied. In the present study, we assayed cPA formation from lysophosphatidylcholine in fetal bovine serum and found significant activity of transphosphatidylation that generated cPA. The cPA-producing enzyme was purified from fetal bovine serum using five chromatographic steps yielding a 100-kDa protein with cPA biosynthetic activity. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry of its tryptic peptides revealed that the enzyme shared identical fragments with human autotaxin, a serum lysophospholipase D that produces LPA. Western blot analysis demonstrated that the 100-kDa protein was specifically recognized by an anti-human autotaxin antibody. Moreover, recombinant rat autotaxin was found to generate cPA in addition to LPA. No significant cPA- or LPA-producing activity was detected in autotaxin-depleted serum from bovine or human prepared by immunoprecipitation with an anti-autotaxin monoclonal antibody. These results indicate that the generation of cPA and LPA in serum is mainly attributed to autotaxin.