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1.
Mol Psychiatry ; 29(5): 1510-1520, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38317011

RESUMO

Humanized mouse models can be used to explore human gene regulatory elements (REs), which frequently lie in non-coding and less conserved genomic regions. Epigenetic modifications of gene REs, also in the context of gene x environment interactions, have not yet been explored in humanized mouse models. We applied high-accuracy measurement of DNA methylation (DNAm) via targeted bisulfite sequencing (HAM-TBS) to investigate DNAm in three tissues/brain regions (blood, prefrontal cortex and hippocampus) of mice carrying the human FK506-binding protein 5 (FKBP5) gene, an important candidate gene associated with stress-related psychiatric disorders. We explored DNAm in three functional intronic glucocorticoid-responsive elements (at introns 2, 5, and 7) of FKBP5 at baseline, in cases of differing genotype (rs1360780 single nucleotide polymorphism), and following application of the synthetic glucocorticoid dexamethasone. We compared DNAm patterns in the humanized mouse (N = 58) to those in human peripheral blood (N = 447 and N = 89) and human postmortem brain prefrontal cortex (N = 86). Overall, DNAm patterns in the humanized mouse model seem to recapitulate DNAm patterns observed in human tissue. At baseline, this was to a higher extent in brain tissue. The animal model also recapitulated effects of dexamethasone on DNAm, especially in peripheral blood and to a lesser extent effects of genotype on DNAm. The humanized mouse model could thus assist in reverse translation of human findings in psychiatry that involve genetic and epigenetic regulation in non-coding elements.


Assuntos
Encéfalo , Metilação de DNA , Epigênese Genética , Córtex Pré-Frontal , Proteínas de Ligação a Tacrolimo , Animais , Humanos , Proteínas de Ligação a Tacrolimo/genética , Proteínas de Ligação a Tacrolimo/metabolismo , Metilação de DNA/genética , Camundongos , Encéfalo/metabolismo , Córtex Pré-Frontal/metabolismo , Masculino , Feminino , Epigênese Genética/genética , Dexametasona/farmacologia , Polimorfismo de Nucleotídeo Único/genética , Sequências Reguladoras de Ácido Nucleico/genética , Adulto , Camundongos Transgênicos , Pessoa de Meia-Idade , Hipocampo/metabolismo , Glucocorticoides/farmacologia , Genótipo
2.
Stress ; 27(1): 2351394, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38752853

RESUMO

Exposure to significant levels of stress and trauma throughout life is a leading risk factor for the development of major psychiatric disorders. Despite this, we do not have a comprehensive understanding of the mechanisms that explain how stress raises psychiatric disorder risk. Stress in humans is complex and produces variable molecular outcomes depending on the stress type, timing, and duration. Deciphering how stress increases disorder risk has consequently been challenging to address with the traditional single-target experimental approaches primarily utilized to date. Importantly, the molecular processes that occur following stress are not fully understood but are needed to find novel treatment targets. Sequencing-based omics technologies, allowing for an unbiased investigation of physiological changes induced by stress, are rapidly accelerating our knowledge of the molecular sequelae of stress at a single-cell resolution. Spatial multi-omics technologies are now also emerging, allowing for simultaneous analysis of functional molecular layers, from epigenome to proteome, with anatomical context. The technology has immense potential to transform our understanding of how disorders develop, which we believe will significantly propel our understanding of how specific risk factors, such as stress, contribute to disease course. Here, we provide our perspective of how we believe these technologies will transform our understanding of the neurobiology of stress, and also provided a technical guide to assist molecular psychiatry and stress researchers who wish to implement spatial omics approaches in their own research. Finally, we identify potential future directions using multi-omics technology in stress research.


Assuntos
Transtornos Mentais , Estresse Psicológico , Humanos , Proteômica , Genômica
3.
J Neurosci ; 42(36): 6823-6834, 2022 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-38377014

RESUMO

Dysregulation of excitatory and inhibitory signaling is commonly observed in major psychiatric disorders, including schizophrenia, depression, and bipolar disorder, and is often targeted by psychological and pharmacological treatment methods. The balance of excitation and inhibition is highly sensitive to severe psychological stress, one of the strongest risk factors for psychiatric disorders. The role of astrocytes in regulating excitatory and inhibitory signaling is now widely recognized; however, the specific involvement of astrocytes in the context of psychiatric disorders with a history of significant stress exposure remains unclear. In this review, we summarize how astrocytes regulate the balance of excitation and inhibition in the context of stress exposure and severe psychopathology, with a focus on the PFC, a brain area highly implicated in psychopathology. We first focus on preclinical models to demonstrate that the duration of stress (particularly acute vs chronic stress) is key to shaping astrocyte function and downstream behavior. We then provide a hypothesis for how astrocytes are involved in stress-associated cortical signaling imbalance, discuss how this directly contributes to phenotypes of psychopathologies, and provide suggestions for future research. We highlight that astrocytes are a key target to understand and treat the dysregulation of cortical signaling associated with stress-related psychiatric disorders.


Assuntos
Transtornos Mentais , Esquizofrenia , Humanos , Astrócitos/fisiologia , Transdução de Sinais , Inibição Psicológica
4.
Acta Neuropathol ; 145(4): 439-459, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36729133

RESUMO

Identification and characterisation of novel targets for treatment is a priority in the field of psychiatry. FKBP5 is a gene with decades of evidence suggesting its pathogenic role in a subset of psychiatric patients, with potential to be leveraged as a therapeutic target for these individuals. While it is widely reported that FKBP5/FKBP51 mRNA/protein (FKBP5/1) expression is impacted by psychiatric disease state, risk genotype and age, it is not known in which cell types and sub-anatomical areas of the human brain this occurs. This knowledge is critical to propel FKBP5/1-targeted treatment development. Here, we performed an extensive, large-scale postmortem study (n = 1024) of FKBP5/1, examining neocortical areas (BA9, BA11 and ventral BA24/BA24a) derived from subjects that lived with schizophrenia, major depression or bipolar disorder. With an extensive battery of RNA (bulk RNA sequencing, single-nucleus RNA sequencing, microarray, qPCR, RNAscope) and protein (immunoblot, immunohistochemistry) analysis approaches, we thoroughly investigated the effects of disease state, ageing and genotype on cortical FKBP5/1 expression including in a cell type-specific manner. We identified consistently heightened FKBP5/1 levels in psychopathology and with age, but not genotype, with these effects strongest in schizophrenia. Using single-nucleus RNA sequencing (snRNAseq; BA9 and BA11) and targeted histology (BA9, BA24a), we established that these disease and ageing effects on FKBP5/1 expression were most pronounced in excitatory superficial layer neurons of the neocortex, and this effect appeared to be consistent in both the granular and agranular areas examined. We then found that this increase in FKBP5 levels may impact on synaptic plasticity, as FKBP5 gex levels strongly and inversely correlated with dendritic mushroom spine density and brain-derived neurotrophic factor (BDNF) levels in superficial layer neurons in BA11. These findings pinpoint a novel cellular and molecular mechanism that has potential to open a new avenue of FKBP51 drug development to treat cognitive symptoms in psychiatric disorders.


Assuntos
Transtornos Mentais , Neocórtex , Humanos , Transtornos Mentais/genética , Envelhecimento/genética , Neurônios , Genótipo , Polimorfismo de Nucleotídeo Único
5.
Neurochem Res ; 43(8): 1683-1691, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29936568

RESUMO

Dysfunction of the glutamatergic system is believed to underlie many neurodevelopmental disorders including autism, Rett syndrome and schizophrenia. Metabotropic glutamate receptor (mGluR5) positive allosteric modulators (PAM) potentiate glutamatergic signaling, particularly indirectly via the NMDA receptor. Preclinical studies report mGluR5 PAMs can improve schizophrenia-relevant behaviours. Furthermore, adolescent administration has shown to prevent cognitive induced deficits in adult rodents. However, there is limited understanding of the short- and long-term neurochemical effects of mGluR5 PAMs, which may underlie their therapeutic effects. We examined the effect of 7-day adolescent (PN28-34) treatment with the mGluR5 PAM, CDDPB (30 mg/kg), on glutamatergic receptor expression at adolescence (PN35) and adulthood (PN96). Immunoblot analysis revealed that 7-day adolescent CDPPB treatment increased protein expression of glutamatergic receptors including the NMDA receptor subunits, NR1 and NR2A and the AMPA subunits (GluA1 and GluA2) in the adolescent hippocampus, changes that did not extend to adulthood. In contrast, there were no changes in the adolescent frontal cortex, however elevated mGluR5 protein expression was observed at adulthood following adolescent CDPPB treatment. The present study indicates adolescent CDPPB treatment may cause brain region dependent effects on the glutamatergic system, which do not persist into adulthood. These findings may have implications for the preclinical development of mGluR5 PAMs for the treatment of neurodevelopmental disorders.


Assuntos
Benzamidas/farmacologia , Pirazóis/farmacologia , Receptor de Glutamato Metabotrópico 5/metabolismo , Animais , Feminino , Lobo Frontal/metabolismo , Hipocampo/metabolismo , Masculino , Gravidez , Ratos Sprague-Dawley , Fatores de Tempo
6.
Acta Neuropathol ; 130(1): 119-29, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25778620

RESUMO

Knockout of genes encoding metabotropic glutamate receptor 5 (mGluR5) or its endogenous regulators, such as Norbin, induce a schizophrenia-like phenotype in rodents, suggesting dysregulation of mGluR5 in schizophrenia. Human genetic and pharmacological animal studies support this hypothesis, but no studies have explored mGluR5 dysfunction at the molecular level in the postmortem schizophrenia brain. We assessed mGluR5 mRNA and protein levels in the dorsolateral prefrontal cortex (DLPFC) using a large cohort of schizophrenia and control subjects (n = 37/group), and additionally measured protein levels of recently discovered mGluR5 endogenous regulators, Norbin (neurochondrin), Tamalin (GRASP-1), and Preso1 (FRMPD4), which regulate mGluR5 localization, internalization and signaling. While mGluR5 mRNA expression was unchanged, mGluR5 protein levels were significantly higher in schizophrenia subjects compared to controls (total: +22%; dimer: +54%; p < 0.001). Conversely, mGluR5 regulatory proteins were expressed at lower levels in schizophrenia subjects compared to controls (Norbin -37%, p < 0.001; Tamalin -30%, p = 0.084; Preso1 -29%, p = 0.001). mGluR5 protein was significantly associated with mGluR5 mRNA and mGluR5 endogenous regulators in control subjects, but these associations were lost in schizophrenia subjects. Lastly, there were no associations between protein measures and lifetime antipsychotic history in schizophrenia subjects. To confirm no antipsychotic influence, all proteins were measured in the prefrontal cortex of rats exposed to haloperidol or olanzapine; there were no effects of antipsychotic drug treatment on mGluR5, Norbin, Tamalin or Preso1. The results from our study provide compelling evidence that mGluR5 regulation is altered in schizophrenia, likely contributing to the altered glutamatergic signaling that is associated with the disorder.


Assuntos
Córtex Pré-Frontal/metabolismo , Receptor de Glutamato Metabotrópico 5/metabolismo , Esquizofrenia/metabolismo , Adolescente , Adulto , Idoso , Animais , Antipsicóticos/farmacologia , Proteínas de Transporte/metabolismo , Estudos de Coortes , Modelos Animais de Doenças , Feminino , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Masculino , Proteínas de Membrana/metabolismo , Pessoa de Meia-Idade , Proteínas do Tecido Nervoso/metabolismo , Neuropeptídeos/metabolismo , Córtex Pré-Frontal/efeitos dos fármacos , RNA Mensageiro/metabolismo , Ratos Sprague-Dawley , Esquizofrenia/tratamento farmacológico , Adulto Jovem
7.
J Psychiatry Neurosci ; 39(6): 407-16, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24949866

RESUMO

BACKGROUND: Metabotropic glutamate receptors 2/3 (mGluR2/3) and 5 (mGluR5) are novel therapeutic targets for major depression (MD), bipolar disorder (BD) and schizophrenia. We aimed to determine whether mGluR2/3 and mGluR5 binding in the anterior cingulate cortex (ACC), a brain region essential for the regulation of mood, cognition and emotion, were differentially altered in these pathologies. METHODS: Using postmortem human brains derived from 2 cohorts, [(3)H]LY341495 binding to mGluR2/3 and [(3)H]MPEP binding to mGluR5 were measured by receptor autoradiography in the ACC. The first cohort comprised samples from individuals who had MD with psychosis (MDP), MD without psychosis (MDNP) and matched controls (n = 11-12 per group). The second cohort comprised samples from individuals who had MDNP, BD, schizophrenia and matched controls (n = 15 per group). RESULTS: No differences in mGluR2/3 or mGluR5 binding were observed in the MDP, MDNP, BD or schizophrenia groups compared with the control group (all p > 0.05). Importantly, there were also no differences in binding densities between the psychiatric disorders (p > 0.05). We did, however, observe age-related effects, with consistent negative associations between mGluR2/3 and age in the control group (r < -0.575, p < 0.025) and the psychotic disorder groups (MDP and schizophrenia: r = -0.765 to -0.515, p < 0.05), but not in the mood disorder groups (MDNP, BD). LIMITATIONS: Replication in larger independent cohorts and medication-naive individuals would strengthen these findings. CONCLUSION: Our findings suggest that mGluRs are unaltered in the ACC; however, the presence of altered receptor function cannot be discounted and requires further investigation. Taken together with previous studies, which report differential changes in mGluR2, 3 and 5 across these disorders, we suggest mGluRs may be affected in a brain region-specific manner.


Assuntos
Transtorno Bipolar/metabolismo , Transtorno Depressivo Maior/metabolismo , Giro do Cíngulo/metabolismo , Transtornos Psicóticos/metabolismo , Receptores de Glutamato Metabotrópico/metabolismo , Esquizofrenia/metabolismo , Adulto , Envelhecimento/metabolismo , Autorradiografia , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Receptor de Glutamato Metabotrópico 5/metabolismo , Adulto Jovem
8.
BMC Psychiatry ; 14: 23, 2014 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-24472577

RESUMO

BACKGROUND: Pharmacological modulation of metabotropic glutamate receptor 5 (mGluR5) is of marked interest as a novel therapeutic mechanism to treat schizophrenia and major depression. However, the status of mGluR5 in the pathophysiology of these disorders remains unknown. DISCUSSION: The majority of studies in the schizophrenia post-mortem brain indicate that total mGluR5 expression is unaltered. However, close examination of the literature suggests that these findings are superficial, and in actuality, a number of critical factors have not yet been considered; alterations may be highly dependent on brain region, neuronal population or molecular organisation in specific cellular compartments. A number of genetic knockout studies (mGluR5, Norbin, Homer1 etc.) continue to lend support to a role of mGluR5 in the pathology of schizophrenia, providing impetus to explore the regulation of mGluR5 beyond total mGluR5 protein and mRNA levels. With regards to major depression, preliminary evidence to date shows a reduction in total mGluR5 protein and mRNA levels; however, as in schizophrenia, there are no studies examining mGluR5 function or regulation in the pathological state. A comprehensive understanding of mGluR5 regulation in major depression, particularly in comparison to schizophrenia, is crucial as this has extensive implications for mGluR5 targeting novel therapeutics, especially considering that opposing modulation of mGluR5 is of therapeutic interest for these two disorders. SUMMARY: Despite the complexities, examinations of post-mortem human brain provide valuable insights into the pathologies of these inherently human disorders. It is important, especially with regards to the identification of novel therapeutic drug targets, to have an in depth understanding of the pathophysiologies of these disorders. We posit that brain region- and cell type-specific alterations exist in mGluR5 in schizophrenia and depression, with evidence pointing towards altered regulation of this receptor in psychiatric pathology. We consider the implications of these alterations, as well as the distinction between schizophrenia and depression, in the context of novel mGluR5 based therapeutics.


Assuntos
Transtorno Depressivo Maior/tratamento farmacológico , Terapia de Alvo Molecular , Psicotrópicos/uso terapêutico , Receptor de Glutamato Metabotrópico 5/antagonistas & inibidores , Esquizofrenia/tratamento farmacológico , Encéfalo/metabolismo , Transtorno Depressivo Maior/metabolismo , Desenho de Fármacos , Humanos , Psicotrópicos/farmacologia , Receptor de Glutamato Metabotrópico 5/genética , Receptor de Glutamato Metabotrópico 5/fisiologia
9.
Neuroscientist ; : 10738584241252581, 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38757781

RESUMO

The existence of neurogenesis in the adult human hippocampus has been under considerable debate within the past three decades due to the diverging conclusions originating mostly from immunohistochemistry studies. While some of these reports conclude that hippocampal neurogenesis in humans occurs throughout physiologic aging, others indicate that this phenomenon ends by early childhood. More recently, some groups have adopted next-generation sequencing technologies to characterize with more acuity the extent of this phenomenon in humans. Here, we review the current state of research on adult hippocampal neurogenesis in the human brain with an emphasis on the challenges and limitations of using immunohistochemistry and next-generation sequencing technologies for its study.

10.
Life (Basel) ; 14(5)2024 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-38792645

RESUMO

Familial Alzheimer's disease (FAD) can be caused by mutations in PSEN1 that encode presenilin-1, a component of the gamma-secretase complex that cleaves amyloid precursor protein. Alterations in calcium (Ca2+) homeostasis and glutamate signaling are implicated in the pathogenesis of FAD; however, it has been difficult to assess in humans whether or not these phenotypes are the result of amyloid or tau pathology. This study aimed to assess the early calcium and glutamate phenotypes of FAD by measuring the Ca2+ response of induced pluripotent stem cell (iPSC)-derived neurons bearing PSEN1 mutations to glutamate and the ionotropic glutamate receptor agonists NMDA, AMPA, and kainate compared to isogenic control and healthy lines. The data show that in early neurons, even in the absence of amyloid and tau phenotypes, FAD neurons exhibit increased Ca2+ responses to glutamate and AMPA, but not NMDA or kainate. Together, this suggests that PSEN1 mutations alter Ca2+ and glutamate signaling as an early phenotype of FAD.

12.
Transl Psychiatry ; 12(1): 257, 2022 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-35732622

RESUMO

Alzheimer's disease (AD) is a progressive neurodegenerative disorder leading to loss of cognitive abilities and ultimately, death. With no cure available, limited treatments mostly focus on symptom management. Identifying early changes in the disease course may provide new therapeutic targets to halt or reverse disease progression. Clinical studies have shown that cortical and hippocampal hyperactivity are a feature shared by patients in the early stages of disease, progressing to hypoactivity during later stages of neurodegeneration. The exact mechanisms causing neuronal excitability changes are not fully characterized; however, animal and cell models have provided insights into some of the factors involved in this phenotype. In this review, we summarize the evidence for neuronal excitability changes over the course of AD onset and progression and the molecular mechanisms underpinning these differences. Specifically, we discuss contributors to aberrant neuronal excitability, including abnormal levels of intracellular Ca2+ and glutamate, pathological amyloid ß (Aß) and tau, genetic risk factors, including APOE, and impaired inhibitory interneuron and glial function. In light of recent research indicating hyperexcitability could be a predictive marker of cognitive dysfunction, we further argue that the hyperexcitability phenotype could be leveraged to improve the diagnosis and treatment of AD, and present potential targets for future AD treatment development.


Assuntos
Doença de Alzheimer , Doença de Alzheimer/genética , Peptídeos beta-Amiloides/metabolismo , Animais , Hipocampo/metabolismo , Humanos , Neurônios/metabolismo , Fenótipo
13.
Neurosci Biobehav Rev ; 124: 193-215, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33556389

RESUMO

Severe stress is among the most robust risk factors for the development of psychiatric disorders. Imaging studies indicate that life stress is integral to shaping the human brain, especially regions involved in processing the stress response. Although this is likely underpinned by changes to the cytoarchitecture of cellular networks in the brain, we are yet to clearly understand how these define a role for stress in human psychopathology. In this review, we consolidate evidence of macro-structural morphometric changes and the cellular mechanisms that likely underlie them. Focusing on stress-sensitive regions of the brain, we illustrate how stress throughout life may lead to persistent remodelling of the both neurons and glia in cellular networks and how these may lead to psychopathology. We support that greater translation of cellular alterations to human cohorts will support parsing the psychological sequalae of severe stress and improve our understanding of how stress shapes the human brain. This will remain a critical step for improving treatment interventions and prevention outcomes.


Assuntos
Transtornos Mentais , Córtex Pré-Frontal , Encéfalo , Forma Celular , Humanos , Estresse Psicológico
14.
Psychiatry Res ; 296: 113661, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33373807

RESUMO

Displacement of people from their homes, families and countries is a current global crisis, with over 70 million people forcibly on the move. A substantial proportion of these people will end up in regions with a different language and culture, where they are registered as refugees or asylum seekers. Due to the underlying reasons for displacement (including conflicts, persecution or violation of human rights), displaced people are severely stress-exposed, which continues into their post-migration life and increases risk for developing psychiatric disorders such as post-traumatic stress disorder and other anxiety disorders and mood disorders. While landmark studies have illustrated the increased prevalence of psychopathology in asylum seeker and refugee populations following pre-/post-displacement stress, few studies add to our understanding of the basic biological mechanisms underpinning risk to psychiatric disorders in these populations. Additionally, the mechanisms underlying resilience despite significant adversity remain unclear. Understanding the molecular mechanisms underpinning the development of psychiatric disorders in refugees can propel treatments (both drug and non-drug) that are capable of influencing biology at the molecular level, and the design of interventions. In the following review, we summarise the status quo of research investigating the pathophysiology of psychiatric disorders in refugees, and propose new ways to address gaps in knowledge with multidisciplinary research.


Assuntos
Transtornos Mentais/epidemiologia , Saúde Mental/etnologia , Trauma Psicológico/etnologia , Psicopatologia , Refugiados/psicologia , Transtornos de Estresse Pós-Traumáticos/psicologia , Estresse Psicológico/etnologia , Transtornos de Ansiedade , Humanos , Hidrocortisona/sangue , Masculino , Transtornos do Humor , Prevalência , Trauma Psicológico/diagnóstico , Trauma Psicológico/psicologia , Refugiados/estatística & dados numéricos , Transtornos de Estresse Pós-Traumáticos/diagnóstico , Transtornos de Estresse Pós-Traumáticos/etnologia , Estresse Psicológico/diagnóstico , Estresse Psicológico/psicologia
15.
Front Psychiatry ; 11: 718, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32793006

RESUMO

Cathepsins are proteases with functions in cellular homeostasis, lysosomal degradation and autophagy. Their role in the development of neurodegenerative diseases has been extensively studied. It is well established that impairment of proper cathepsin function plays a crucial role in the pathophysiology of neurodegenerative diseases, and in recent years a role for cathepsins in mental disorders has emerged given the involvement of cathepsins in memory function, hyperactivity, and in depression- and anxiety-like behavior. Here we review putative cathepsin functions with a special focus on their role in the pathophysiology of psychiatric diseases. Specifically, cathepsins are crucial for maintaining cellular homeostasis, particularly as part of the autophagy machinery of neural strategies underlying acute stress response. Disruption of cathepsin functions can lead to psychiatric diseases such as major depressive disease (MDD), bipolar disorder, and schizophrenia. Specifically, cathepsins can be excreted via a process called secretory autophagy. Thereby, they are able to regulate extracellular factors such as brain-derived neurotrophic factor and perlecan c-terminal fragment LG3 providing maintenance of neuronal homeostasis and mediating neuronal plasticity in response to acute stress or trauma. In addition, impairment of proper cathepsin function can result in impaired synaptic transmission by compromised recycling and biogenesis of synaptic vesicles. Taken together, further investigations on cathepsin functions and stress response, neuroplasticity, and synaptic transmission will be of great interest in understanding the pathophysiology of psychiatric disorders.

16.
Neurobiol Stress ; 13: 100270, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33344723

RESUMO

Severe stress exposure causes the loss of dendritic spines on cortical pyramidal neurons and induces psychiatric-like symptoms in rodent models. These effects are strongest following early-life stress and are most persistent on apical dendrites. However, the long-term impacts and temporal effects of stress exposure on the human brain remain poorly understood. Using a novel postmortem cohort of psychiatric cases with severe stress experienced in childhood, adulthood, or no severe stress, and matched controls, we aimed to determine the impact of stress timing on pyramidal neuron structure in the human orbitofrontal cortex (OFC). We performed Golgi Cox staining and manually measured the morphology and density of over 22,000 dendritic spines on layer-specific pyramidal neuron apical dendrites. We also quantified glucocorticoid receptor mRNA and protein as a marker of stress dysregulation. Both childhood and adulthood stress were associated with large reductions in mature mushroom spine density (up to 56% loss) in both the superficial (II/III) and deeper layers (V) of the OFC. However, childhood stress caused more substantial reductions to both total and mature mushroom spines. No difference in glucocorticoid receptor mRNA and protein were seen between groups, although both negatively correlated with total spine density within the whole cohort. These findings indicate that severe stress, especially when experienced during childhood, persistently affects the fine morphological properties of neurons in the human OFC. This may impact on cell connectivity in this brain area, and at least partly explain the social and emotional symptoms that originate in the OFC in psychiatric disorders.

17.
Biol Psychiatry ; 83(10): 821-830, 2018 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-29573791

RESUMO

Epidemiologic and genetic studies suggest common environmental and genetic risk factors for a number of psychiatric disorders, including depression, bipolar disorder, and schizophrenia. Genetic and environmental factors, especially adverse life events, not only have main effects on disease development but also may interact to shape risk and resilience. Such gene by adversity interactions have been described for FKBP5, an endogenous regulator of the stress-neuroendocrine system, conferring risk for a number of psychiatric disorders. In this review, we present a molecular and cellular model of the consequences of FKBP5 by early adversity interactions. We illustrate how altered genetic and epigenetic regulation of FKBP5 may contribute to disease risk by covering evidence from clinical and preclinical studies of FKBP5 dysregulation, known cell-type and tissue-type expression patterns of FKBP5 in humans and animals, and the role of FKBP5 as a stress-responsive molecular hub modulating many cellular pathways. FKBP5 presents the possibility to better understand the molecular and cellular factors contributing to a disease-relevant gene by environment interaction, with implications for the development of biomarkers and interventions for psychiatric disorders.


Assuntos
Epigênese Genética/genética , Interação Gene-Ambiente , Transtornos Mentais/genética , Mutação/genética , Proteínas de Ligação a Tacrolimo/genética , Genótipo , Humanos , Transtornos Mentais/epidemiologia , Estresse Psicológico
19.
Neuronal Signal ; 2(3): NS20180059, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32714588

RESUMO

Postnatal administration of phencyclidine (PCP) in rodents causes major brain dysfunction leading to severe disturbances in behavior lasting into adulthood. This model is routinely employed to model psychiatric disorders such as schizophrenia, as it reflects schizophrenia-related brain disturbances including increased apoptosis, and disruptions to myelin and plasticity processes. Leucine-rich repeat and Immunoglobin-like domain-containing protein 1 (Lingo-1) is a potent negative regulator of both axonal myelination and neurite extension. The Nogo receptor (NgR)/tumor necrosis factor (TNF) receptor orphan Y (TROY) and/or p75 neurotrophin receptor (p75) complex, with no lysine (K) (WNK1) and myelin transcription factor 1 (Myt1) are co-receptors or cofactors in Lingo-1 signaling pathways in the brain. We have examined the developmental trajectory of these proteins in a neurodevelopmental model of schizophrenia using PCP to determine if Lingo-1 pathways are altered in the prefrontal cortex throughout different stages of life. Sprague-Dawley rats were injected with PCP (10 mg/kg) or saline on postnatal days (PN)7, 9, and 11 and killed at PN12, 5 or 14 weeks for measurement of Lingo-1 signaling proteins in the prefrontal cortex. Myt1 was decreased by PCP at PN12 (P=0.045), and at 14 weeks PCP increased Lingo-1 (P=0.037), TROY (P=0.017), and WNK1 (P=0.003) expression. This is the first study reporting an alteration in Lingo-1 signaling proteins in the rat prefrontal cortex both directly after PCP treatment in early development and in adulthood. We propose that Lingo-1 pathways may be negatively regulating myelination and neurite outgrowth following the administration of PCP, and that this may have implications for the cortical dysfunction observed in schizophrenia.

20.
Artigo em Inglês | MEDLINE | ID: mdl-29247760

RESUMO

BACKGROUND: The single nucleotide polymorphism (SNP) rs1344706 [A>C] within intron 2 of the zinc finger protein 804A gene (ZNF804A) is associated with schizophrenia at the genome-wide level, but its function in relation to the development of psychotic disorders, including its influence on brain morphology remains unclear. METHODS: Using both univariate (voxel-based morphometry, VBM; cortical thickness) and multivariate (source-based morphometry, SBM) approaches, we examined the effects of variation of the rs1344706 polymorphism on grey matter integrity in 214 Caucasian schizophrenia cases and 94 Caucasian healthy individuals selected from the Australian Schizophrenia Research Bank. RESULTS: Neither univariate nor multivariate analyses showed any associations between indices of grey matter and rs1344706 variation in schizophrenia or healthy participants. This was revealed in the context of the typical pattern of decreased grey matter integrity in schizophrenia compared to healthy individuals, including: (1) large grey matter volume reductions in the orbitofrontal and anterior cingulate cortices and the left fusiform/inferior temporal gyri; (2) decreased cortical thickness in the left inferior temporal and fusiform gyri, the left orbitofrontal gyrus, as well as in the right pars opercularis/precentral gyrus; and (3) decreased covariation of grey matter concentration in frontal and limbic brain regions emerging from the SBM analyses. CONCLUSIONS: Contrary to some - but not all - previous findings, this study of a large sample of schizophrenia cases and healthy controls reveals no evidence for association between grey matter alterations and variation in rs1344706 (ZNF804A). Differences in sample sizes and ethnicities may account for discrepant findings between the present and previous studies.


Assuntos
Encéfalo/diagnóstico por imagem , Fatores de Transcrição Kruppel-Like/genética , Transtornos Psicóticos/diagnóstico por imagem , Transtornos Psicóticos/genética , Esquizofrenia/diagnóstico por imagem , Esquizofrenia/genética , Adulto , Encéfalo/anatomia & histologia , Encéfalo/patologia , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Estudos de Associação Genética , Substância Cinzenta/anatomia & histologia , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/patologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Tamanho do Órgão , Polimorfismo de Nucleotídeo Único , Transtornos Psicóticos/patologia , Esquizofrenia/patologia , População Branca/genética
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