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1.
Hum Mol Genet ; 30(22): 2135-2148, 2021 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-34218272

RESUMEN

Germline mutation of PTEN is causally observed in Cowden syndrome (CS) and is one of the most common, penetrant risk genes for autism spectrum disorder (ASD). However, the majority of individuals who present with CS-like clinical features are PTEN-mutation negative. Reassessment of PTEN promoter regulation may help explain abnormal PTEN dosage, as only the minimal promoter and coding regions are currently included in diagnostic PTEN mutation analysis. Therefore, we reanalyzed the architecture of the PTEN promoter using next-generation sequencing datasets. Specifically, run-on sequencing assays identified two additional transcription start regions (TSRs) at -2053 and -1906 basepairs from the canonical start of PTEN, thus extending the PTEN 5'UTR and redefining the PTEN promoter. We show that these novel upstream TSRs are active in cancer cell lines, human cancer and normal tissue. Furthermore, these TSRs can produce novel PTEN transcripts due to the introduction of new splice donors at -2041, -1826 and -1355, which may allow for splicing out of the PTEN 5'UTR or the first and second exon in upstream-initiated transcripts. Combining ENCODE ChIP-seq and pertinent literature, we also compile and analyze all transcription factors (TFs) binding at the redefined PTEN locus. Enrichment analyses suggest that TFs bind specifically to the upstream TSRs may be implicated in inflammatory processes. Altogether, these data redefine the architecture of the PTEN promoter, an important step toward a comprehensive model of PTEN transcription regulation, a basis for future investigations into the new promoters' role in disease pathogenesis.


Asunto(s)
Fosfohidrolasa PTEN/genética , Regiones Promotoras Genéticas , Transcripción Genética , Biología Computacional/métodos , Regulación de la Expresión Génica , Ontología de Genes , Humanos , Sitios de Carácter Cuantitativo , Sitio de Iniciación de la Transcripción
2.
Am J Hum Genet ; 106(6): 818-829, 2020 06 04.
Artículo en Inglés | MEDLINE | ID: mdl-32442409

RESUMEN

Germline variation in PTEN results in variable clinical presentations, including benign and malignant neoplasia and neurodevelopmental disorders. Despite decades of research, it remains unclear how the PTEN genotype is related to clinical outcomes. In this study, we combined two recent deep mutational scanning (DMS) datasets probing the effects of single amino acid variation on enzyme activity and steady-state cellular abundance with a large, well-curated clinical cohort of PTEN-variant carriers. We sought to connect variant-specific molecular phenotypes to the clinical outcomes of individuals with PTEN variants. We found that DMS data partially explain quantitative clinical traits, including head circumference and Cleveland Clinic (CC) score, which is a semiquantitative surrogate of disease burden. We built logistic regression models that use DMS and CADD scores to separate clinical PTEN variation from gnomAD control-only variation with high accuracy. By using a survival-like analysis, we identified molecular phenotype groups with differential risk of early cancer onset as well as lifetime risk of cancer. Finally, we identified classes of DMS-defined variants with significantly different risk levels for classical hamartoma-related features (odds ratio [OR] range of 4.1-102.9). In stark contrast, the risk for developing autism or developmental delay does not significantly change across variant classes (OR range of 5.4-12.4). Together, these findings highlight the potential impact of combining DMS datasets with rich clinical data and provide new insights that might guide personalized clinical decisions for PTEN-variant carriers.


Asunto(s)
Estudios de Asociación Genética , Mutación Missense , Fosfohidrolasa PTEN/genética , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Estudios de Cohortes , Conjuntos de Datos como Asunto , Femenino , Predisposición Genética a la Enfermedad , Hamartoma/genética , Humanos , Incidencia , Modelos Logísticos , Masculino , Persona de Mediana Edad , Neoplasias/clasificación , Neoplasias/genética , Neoplasias/patología , Fosfohidrolasa PTEN/química , Fenotipo , Pronóstico , Adulto Joven
3.
Hum Mol Genet ; 29(14): 2353-2364, 2020 08 11.
Artículo en Inglés | MEDLINE | ID: mdl-32588888

RESUMEN

Individuals with germline mutations in the gene encoding phosphatase and tensin homolog on chromosome ten (PTEN) are diagnosed with PTEN hamartoma tumor syndrome (PHTS) and are at high risk for developing breast, thyroid and other cancers and/or autoimmunity or neurodevelopmental issues including autism spectrum disorders. Although well recognized as a tumor suppressor, involvement of PTEN mutations in mediating such a diverse range of phenotypes indicates a more central involvement for PTEN in immunity than previously recognized. To address this, sequencing of the T-cell receptor variable-region ß-chain was performed on peripheral blood from PHTS patients. Based on patient findings, we performed mechanistic studies in two Pten knock-in murine models, distinct from each other in cell compartment-specific predominance of Pten. We found that PTEN mutations in humans and mice are associated with a skewed T- and B-cell gene repertoire, characterized by increased prevalence of high-frequency clones. Immunological characterization showed that Pten mutants have increased B-cell proliferation and a proclivity towards increased T-cell reactivity upon Toll-like-receptor stimulation. Furthermore, decreases in nuclear but not cytoplasmic Pten levels associated with a reduction in expression of the autoimmune regulator (Aire), a critical mediator of central immune tolerance. Mechanistically, we show that nuclear PTEN most likely regulates Aire expression via its emerging role in splicing regulation. We conclude that germline disruption of PTEN, both in human and mouse, results in compromised central immune tolerance processes that may significantly impact individual stress responses and therefore predisposition to autoimmunity and cancer.


Asunto(s)
Síndrome de Hamartoma Múltiple/genética , Fosfohidrolasa PTEN/genética , Receptores de Antígenos de Linfocitos T alfa-beta/genética , Factores de Transcripción/genética , Animales , Linfocitos B/inmunología , Linfocitos B/patología , Proliferación Celular/genética , Modelos Animales de Enfermedad , Femenino , Técnicas de Sustitución del Gen , Mutación de Línea Germinal/genética , Síndrome de Hamartoma Múltiple/sangre , Síndrome de Hamartoma Múltiple/inmunología , Síndrome de Hamartoma Múltiple/patología , Humanos , Tolerancia Inmunológica/genética , Masculino , Ratones , Receptores de Antígenos de Linfocitos T alfa-beta/inmunología , Linfocitos T/inmunología , Linfocitos T/patología , Receptores Toll-Like/genética , Receptores Toll-Like/inmunología , Proteína AIRE
4.
Am J Hum Genet ; 104(5): 861-878, 2019 05 02.
Artículo en Inglés | MEDLINE | ID: mdl-31006514

RESUMEN

Individuals with germline PTEN tumor-suppressor variants have PTEN hamartoma tumor syndrome (PHTS). Clinically, PHTS has variable presentations; there are distinct subsets of PHTS-affected individuals, such as those diagnosed with autism spectrum disorder (ASD) or cancer. It remains unclear why mutations in one gene can lead to such seemingly disparate phenotypes. Therefore, we sought to determine whether it is possible to predict a given PHTS-affected individual's a priori risk of ASD, cancer, or the co-occurrence of both phenotypes. By integrating network proximity analysis performed on the human interactome, molecular simulations, and residue-interaction networks, we demonstrate the role of conformational dynamics in the structural communication and long-range allosteric regulation of germline PTEN variants associated with ASD or cancer. We show that the PTEN interactome shares significant overlap with the ASD and cancer interactomes, providing network-based evidence that PTEN is a crucial player in the biology of both disorders. Importantly, this finding suggests that a germline PTEN variant might perturb the ASD or cancer networks differently, thus favoring one disease outcome at any one time. Furthermore, protein-dynamic structural-network analysis reveals small-world structural communication mediated by highly conserved functional residues and potential allosteric regulation of PTEN. We identified a salient structural-communication pathway that extends across the inter-domain interface for cancer-only mutations. In contrast, the structural-communication pathway is predominantly restricted to the phosphatase domain for ASD-only mutations. Our integrative approach supports the prediction and potential modulation of the relevant conformational states that influence structural communication and long-range perturbations associated with mutational effects that lead to PTEN-ASD or PTEN-cancer phenotypes.


Asunto(s)
Trastorno Autístico/genética , Redes Reguladoras de Genes , Mutación de Línea Germinal , Simulación de Dinámica Molecular , Neoplasias/genética , Fosfohidrolasa PTEN/química , Regulación Alostérica , Trastorno Autístico/patología , Humanos , Neoplasias/patología , Fosfohidrolasa PTEN/genética , Fenotipo , Conformación Proteica , Termodinámica
5.
Mol Psychiatry ; 26(5): 1458-1471, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-32055008

RESUMEN

Germline mutations in PTEN account for ~10% of cases of autism spectrum disorder (ASD) with coincident macrocephaly. To explore the importance of nuclear PTEN in the development of ASD and macrocephaly, we previously generated a mouse model with predominantly cytoplasmic localization of Pten (Ptenm3m4/m3m4).Cytoplasmic predominant Pten localization results in a phenotype of extreme macrocephaly and autistic-like traits. Transcriptomic analysis of the Ptenm3m4/m3m4 cortex found upregulated gene pathways related to myeloid cell activation, myeloid cell migration, and phagocytosis. These transcriptomic findings were used to direct in vitro assays on Pten wild-type and Ptenm3m4/m3m4 microglia. We found increased Iba1 and C1q expression with enhanced phagocytic capacity in Ptenm3m4/m3m4 microglia, indicating microglial activation. Moreover, through a series of neuron-microglia co-culture experiments, we found Ptenm3m4/m3m4 microglia are more efficient at synaptic pruning compared with wild-type controls. In addition, we found evidence for neuron-microglia cross-talk, where Ptenm3m4/m3m4 neurons elicit enhanced pruning from innately activated microglia. Subsequent in vivo studies validated our in vitro findings. We observed a concurrent decline in the expression of Pten and synaptic markers in the Ptenm3m4/m3m4 cortex. At ~3 weeks of age, with a 50% drop in Pten expression compared with wild-type levels, we observed enhanced activation of microglia in the Ptenm3m4/m3m4 brain. Collectively, our data provide evidence that dysregulated Pten in microglia has an etiological role in microglial activation, phagocytosis, and synaptic pruning, creating avenues for future studies on the importance of PTEN in maintaining microglia homeostasis.


Asunto(s)
Trastorno del Espectro Autista , Trastorno Autístico , Fosfohidrolasa PTEN/genética , Animales , Trastorno del Espectro Autista/genética , Trastorno Autístico/genética , Modelos Animales de Enfermedad , Ratones , Microglía , Plasticidad Neuronal , Fenotipo
6.
J Chem Inf Model ; 62(17): 4175-4190, 2022 09 12.
Artículo en Inglés | MEDLINE | ID: mdl-36001481

RESUMEN

The phosphatase and tensin homologue deleted on chromosome 10 (PTEN) tumor suppressor gene encodes a tightly regulated dual-specificity phosphatase that serves as the master regulator of PI3K/AKT/mTOR signaling. The carboxy-terminal tail (CTT) is key to regulation and harbors multiple phosphorylation sites (Ser/Thr residues 380-385). CTT phosphorylation suppresses the phosphatase activity by inducing a stable, closed conformation. However, little is known about the mechanisms of phosphorylation-induced CTT-deactivation dynamics. Using explicit solvent microsecond molecular dynamics simulations, we show that CTT phosphorylation leads to a partially collapsed conformation, which alters the secondary structure of PTEN and induces long-range conformational rearrangements that encompass the active site. The active site rearrangements prevent localization of PTEN to the membrane, precluding lipid phosphatase activity. Notably, we have identified phosphorylation-induced allosteric coupling between the interdomain region and a hydrophobic site neighboring the active site in the phosphatase domain. Collectively, the results provide a mechanistic understanding of CTT phosphorylation dynamics and reveal potential druggable allosteric sites in a previously believed clinically undruggable protein.


Asunto(s)
Fosfohidrolasa PTEN , Fosfatidilinositol 3-Quinasas , Simulación de Dinámica Molecular , Fosfohidrolasa PTEN/química , Fosfohidrolasa PTEN/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Fosforilación , Estructura Secundaria de Proteína , Transducción de Señal
7.
medRxiv ; 2024 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-38766118

RESUMEN

Background: Despite monogenic and polygenic contributions to cardiovascular disease (CVD), genetic testing is not widely adopted, and current tests are limited by the breadth of surveyed conditions and interpretation burden. Methods: We developed a comprehensive clinical genome CVD test with semi-automated interpretation. Monogenic conditions and risk alleles were selected based on the strength of disease association and evidence for increased disease risk, respectively. Non-CVD secondary findings genes, pharmacogenomic (PGx) variants and CVD polygenic risk scores (PRS) were assessed for inclusion. Test performance was modeled using 2,594 genomes from the 1000 Genomes Project, and further investigated in 20 previously tested individuals. Results: The CVD genome test is composed of a panel of 215 CVD gene-disease pairs, 35 non-CVD secondary findings genes, 4 risk alleles or genotypes, 10 PGx genes and a PRS for coronary artery disease. Modeling of test performance using samples from the 1000 Genomes Project revealed ~6% of individuals with a monogenic finding in a CVD-associated gene, 6% with a risk allele finding, ~1% with a non-CVD secondary finding, and 93% with CVD-associated PGx variants. Assessment of blinded clinical samples showed complete concordance with prior testing. An average of 4 variants were reviewed per case, with interpretation and reporting time ranging from 9-96 min. Conclusions: A genome sequencing based CVD genetic risk assessment can provide comprehensive genetic disease and genetic risk information to patients with CVD. The semi-automated and limited interpretation burden suggest that this testing approach could be scaled to support population-level initiatives.

8.
NPJ Genom Med ; 6(1): 42, 2021 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-34078911

RESUMEN

PTEN has a strong Mendelian association with autism spectrum disorder (ASD), representing a special case in autism's complex genetic architecture. Animal modeling for constitutional Pten mutation creates an opportunity to study how disruption of Pten affects neurobiology and glean potential insight into ASD pathogenesis. Subsequently, we comprehensively characterized the neural (phospho)proteome of Ptenm3m4/m3m4 mice, which exhibits cytoplasmic-predominant Pten expression, by applying mass spectrometry technology to their brains at two-weeks- (P14) and six-weeks-of-age (P40). The differentially expressed/phosphorylated proteins were subjected to gene enrichment, pathway, and network analyses to assess the affected biology. We identified numerous differentially expressed/phosphorylated proteins, finding greater dysregulation at P40 consistent with prior transcriptomic data. The affected pathways were largely related to PTEN function or neurological processes, while scant direct overlap was found across datasets. Network analysis pointed to ASD risk genes like Pten and Psd-95 as major regulatory hubs, suggesting they likely contribute to initiation or maintenance of cellular and perhaps organismal phenotypes related to ASD.

9.
Mol Autism ; 12(1): 41, 2021 06 04.
Artículo en Inglés | MEDLINE | ID: mdl-34088332

RESUMEN

BACKGROUND: Autism spectrum disorder (ASD) has a strong genetic etiology. Germline mutation in the tumor suppressor gene PTEN is one of the best described monogenic risk cases for ASD. Animal modeling of cell-specific Pten loss or mutation has provided insight into how disruptions to the function of PTEN affect neurodevelopment, neurobiology, and social behavior. As such, there is a growing need to understand more about how various aspects of PTEN activity and cell-compartment-specific functions, contribute to certain neurological or behavior phenotypes. METHODS: To understand more about the relationship between Pten localization and downstream effects on neurophenotypes, we generated the nuclear-predominant PtenY68H/+ mouse, which is identical to the genotype of some PTEN-ASD individuals. We subjected the PtenY68H/+ mouse to morphological and behavioral phenotyping, including the three-chamber sociability, open field, rotarod, and marble burying tests. We subsequently performed in vivo and in vitro cellular phenotyping and concluded the work with a transcriptomic survey of the PtenY68H/+ cortex, which profiled gene expression. RESULTS: We observe a significant increase in P-Akt downstream of canonical Pten signaling, macrocephaly, decreased sociability, decreased preference for novel social stimuli, increased repetitive behavior, and increased thigmotaxis in PtenY68H/+ six-week-old (P40) mice. In addition, we found significant microglial activation with increased expression of complement and neuroinflammatory proteins in vivo and in vitro accompanied by enhanced phagocytosis. These observations were subsequently validated with RNA-seq and qRT-PCR, which revealed overexpression of many genes involved in neuroinflammation and neuronal function, including oxytocin. Oxytocin transcript was fivefold overexpressed (P = 0.0018), and oxytocin protein was strongly overexpressed in the PtenY68H/+ hypothalamus. CONCLUSIONS: The nuclear-predominant PtenY68H/+ model has clarified that Pten dysfunction links to microglial pathology and this associates with increased Akt signaling. We also demonstrate that Pten dysfunction associates with changes in the oxytocin system, an important connection between a prominent ASD risk gene and a potent neuroendocrine regulator of social behavior. These cellular and molecular pathologies may related to the observed changes in social behavior. Ultimately, the findings from this work may reveal important biomarkers and/or novel therapeutic modalities that could be explored in individuals with germline mutations in PTEN with ASD.


Asunto(s)
Trastorno del Espectro Autista , Animales , Trastorno del Espectro Autista/genética , Conducta Animal , Modelos Animales de Enfermedad , Células Germinativas/metabolismo , Ratones , Microglía/metabolismo , Neuronas/metabolismo , Conducta Social
10.
Transl Psychiatry ; 10(1): 380, 2020 11 06.
Artículo en Inglés | MEDLINE | ID: mdl-33159038

RESUMEN

Alternative splicing (AS) is a posttranscriptional mechanism regulating gene expression that complex organisms utilize to expand proteome diversity from a comparatively limited set of genes. Recent research has increasingly associated AS with increased functional complexity in the central nervous systems in higher order mammals. This work has heavily implicated aberrant AS in several neurocognitive and neurodevelopmental disorders, including autism. Due to the strong genetic association between germline PTEN mutations and autism spectrum disorder (ASD), we hypothesized that germline PTEN mutations would alter AS patterns, contributing to the pathophysiology of ASD. In a murine model of constitutional mislocalization of Pten, recapitulating an autism-like phenotype, we found significant changes in AS patterns across the neural transcriptome by analyzing RNA-sequencing data with the program rMATS. A few hundred significant alternative splicing events (ASEs) that differentiate each m3m4 genotype were identified. These ASEs occur in genes enriched in PTEN signaling, inositol metabolism, and several other pathways relevant to the pathophysiology of ASD. In addition, we identified expression changes in several splicing factors known to be enriched in the nervous system. For instance, the master regulator of microexons, Srrm4, has decreased expression, and consequently, we found decreased inclusion of microexons in the Ptenm3m4/m3m4 cortex (~10% decrease). We also demonstrated that the m3m4 mutation disrupts the interaction between Pten and U2af2, a member of the spliceosome. In sum, our observations point to germline Pten disruption changing the landscape of alternative splicing in the brain, and these changes may be relevant to the pathogenesis and/or maintenance of PTEN-ASD phenotypes.


Asunto(s)
Empalme Alternativo , Trastorno del Espectro Autista , Trastorno Autístico , Animales , Trastorno del Espectro Autista/genética , Trastorno Autístico/genética , Modelos Animales de Enfermedad , Ratones , Fosfohidrolasa PTEN/genética , Fosfohidrolasa PTEN/metabolismo , Transcriptoma
11.
Mol Autism ; 11(1): 43, 2020 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-32487265

RESUMEN

BACKGROUND: PTEN, a syndromic autism spectrum disorder (ASD) risk gene, is mutated in approximately 10% of macrocephalic ASD cases. Despite the described genetic association between PTEN and ASD and ensuing studies, we continue to have a limited understanding of how PTEN disruption drives ASD pathogenesis and maintenance. METHODS: We derived neural stem cells (NSCs) from the dentate gyrus (DG) of Ptenm3m4 mice, a model that recapitulates PTEN-ASD phenotypes. We subsequently characterized the expression of stemness factors, proliferation, and differentiation of neurons and glia in Ptenm3m4 NSCs using immunofluorescent and immunoblotting approaches. We also measured Creb phosphorylation by Western blot analysis and expression of Creb-regulated genes with qRT-PCR. RESULTS: The m3m4 mutation decreases Pten localization to the nucleus and its global expression over time. Ptenm3m4 NSCs exhibit persistent stemness characteristics associated with increased proliferation and a resistance to neuronal maturation during differentiation. Given the increased proliferation of Ptenm3m4 NSCs, a significant increase in the population of immature neurons relative to mature neurons occurs, an approximately tenfold decrease in the ratio between the homozygous mutant and wildtype. There is an opposite pattern of differentiation in some Ptenm3m4 glia, specifically an increase in astrocytes. These aberrant differentiation patterns associate with changes in Creb activation in Ptenm3m4/m3m4 NSCs. We specifically observed loss of Creb phosphorylation at S133 in Ptenm3m4/m3m4 NSCs and a subsequent decrease in expression of Creb-regulated genes important to neuronal function (i.e., Bdnf). Interestingly, Bdnf treatment is able to partially rescue the stunted neuronal maturation phenotype in Ptenm3m4/m3m4 NSCs. CONCLUSIONS: Constitutional disruption of Pten nuclear localization with subsequent global decrease in Pten expression generates abnormal patterns of differentiation, a stunting of neuronal maturation. The propensity of Pten disruption to restrain neurons to a more progenitor-like state may be an important feature contributing to PTEN-ASD pathogenesis.


Asunto(s)
Diferenciación Celular/genética , Células-Madre Neurales/citología , Células-Madre Neurales/metabolismo , Neurogénesis/genética , Neuronas/citología , Neuronas/metabolismo , Fosfohidrolasa PTEN/genética , Animales , Trastorno del Espectro Autista/etiología , Trastorno del Espectro Autista/metabolismo , Biomarcadores , Núcleo Celular , Proliferación Celular , Autorrenovación de las Células , Células Cultivadas , Modelos Animales de Enfermedad , Ratones , Ratones Noqueados , Mutación , Neuroglía/citología , Neuroglía/metabolismo , Fosfohidrolasa PTEN/metabolismo
12.
J Biomol Struct Dyn ; 37(7): 1766-1782, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29663862

RESUMEN

Individuals with germline mutations in the tumor suppressor gene phosphatase and tensin homolog (PTEN), irrespective of clinical presentation, are diagnosed with PTEN hamartoma tumor syndrome (PHTS). PHTS confers a high risk of breast, thyroid, and other cancers or autism spectrum disorder (ASD) with macrocephaly. It remains unclear why mutations in one gene can lead to seemingly disparate phenotypes. Thus, we sought to identify differences in ASD vs. cancer-associated germline PTEN missense mutations by investigating putative structural effects induced by each mutation. We utilized a theoretical computational approach combining in silico structural analysis and molecular dynamics (MD) to interrogate 17 selected mutations from our patient population: six mutations were observed in patients with ASD (only), six mutations in patients with PHTS-associated cancer (only), four mutations shared across both phenotypes, and one mutation with both ASD and cancer. We demonstrate structural stability changes where all six cancer-associated mutations showed a global decrease in structural stability and increased dynamics across the domain interface with a proclivity to unfold, mediating a closed (inactive) active site. In contrast, five of the six ASD-associated mutations showed localized destabilization that contribute to the partial opening of the active site. Our results lend insight into distinctive structural effects of germline PTEN mutations associated with PTEN-ASD vs. those associated with PTEN-cancer, potentially aiding in identification of the shared and separate molecular features that contribute to autism or cancer, thus, providing a deeper understanding of genotype-phenotype relationships for germline PTEN mutations.


Asunto(s)
Trastorno del Espectro Autista/genética , Mutación de Línea Germinal , Simulación de Dinámica Molecular , Neoplasias/genética , Fosfohidrolasa PTEN/química , Fosfohidrolasa PTEN/genética , Conformación Proteica , Alelos , Sustitución de Aminoácidos , Sitios de Unión , Dominio Catalítico , Predisposición Genética a la Enfermedad , Humanos , Mutación Missense , Unión Proteica , Estabilidad Proteica , Relación Estructura-Actividad
13.
Transl Psychiatry ; 9(1): 13, 2019 01 17.
Artículo en Inglés | MEDLINE | ID: mdl-30664625

RESUMEN

There is a strong genetic association between germline PTEN mutation and autism spectrum disorder (ASD), making Pten-mutant models exemplary for the study of ASD pathophysiology. We developed the Ptenm3m4 mouse, where Pten is largely restricted from the nucleus, which recapitulates patient-like, autism-related phenotypes: behavioral changes, macrocephaly, and white matter abnormalities. This study aimed to investigate the contribution of oligodendrocyte (OL) lineage differentiation and functional changes in myelination to the white matter phenotype. OL lineage differentiation and myelination in Ptenm3m4 mice was studied using immunohistochemical and electron microscopic analyses. We also used primary oligodendrocyte progenitor cells (OPCs) to determine the effect of the Ptenm3m4 mutation on OPC proliferation, migration and maturation. Finally, we assessed the myelinating competency of mutant OLs via co-culture with wildtype dorsal root ganglia (DRG) neurons. The in vivo analyses of Ptenm3m4/m3m4 murine brains showed deficits in proteolipid protein (Plp) trafficking in myelinating OLs. Despite the increased expression of myelin proteins in the brain, myelin deposition was observed to be abnormal, often occurring adjacent to, rather than around axons. Mutant primary OPCs showed enhanced proliferation and migration. Furthermore, mutant OPCs matured precociously, exhibiting aberrant myelination in vitro. Mutant OPCs, when co-cultured with wildtype DRG neurons, showed an inability to properly ensheath axons. Our findings provide evidence that the Ptenm3m4 mutation disrupts the differentiation and myelination programs of developing OLs. OL dysfunction in the Ptenm3m4 model explains the leukodystrophy phenotype, a feature commonly associated with autism, and highlights the growing importance of glial dysfunction in autism pathogenesis.


Asunto(s)
Trastorno del Espectro Autista/fisiopatología , Encéfalo/fisiopatología , Neuroglía/citología , Fosfohidrolasa PTEN/metabolismo , Animales , Diferenciación Celular , Células Cultivadas , Modelos Animales de Enfermedad , Femenino , Masculino , Ratones , Mutación Missense , Proteínas de la Mielina/metabolismo , Neurogénesis , Células Precursoras de Oligodendrocitos/citología , Fosfohidrolasa PTEN/genética
14.
Matrix Biol ; 82: 38-53, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-30738849

RESUMEN

Geleophysic dysplasia is a rare, frequently lethal condition characterized by severe short stature with progressive joint contractures, cardiac, pulmonary, and skin anomalies. Geleophysic dysplasia results from dominant fibrillin-1 (FBN1) or recessive ADAMTSL2 mutations, suggesting a functional link between ADAMTSL2 and fibrillin microfibrils. Mice lacking ADAMTSL2 die at birth, which has precluded analysis of postnatal limb development and mechanisms underlying the skeletal anomalies of geleophysic dysplasia. Here, detailed expression analysis of Adamtsl2 using an intragenic lacZ reporter shows strong Adamtsl2 expression in limb tendons. Expression in developing and growing bones is present in regions that are destined to become articular cartilage but is absent in growth plate cartilage. Consistent with strong tendon expression, Adamtsl2 conditional deletion in limb mesenchyme using Prx1-Cre led to tendon anomalies, albeit with normal collagen fibrils, and distal limb shortening, providing a mouse model for geleophysic dysplasia. Unexpectedly, conditional Adamtsl2 deletion using Scx-Cre, a tendon-specific Cre-deleter strain, which does not delete in cartilage, also impaired skeletal growth. Recombinant ADAMTSL2 is shown here to colocalize with fibrillin microfibrils in vitro, and enhanced staining of fibrillin-1 microfibrils was observed in Prx1-Cre Adamtsl2 tendons. The findings show that ADAMTSL2 specifically regulates microfibril assembly in tendons and that proper microfibril composition in tendons is necessary for tendon growth. We speculate that reduced bone growth in geleophysic dysplasia may result from external tethering by short tendons rather than intrinsic growth plate anomalies. Taken together with previous work, we suggest that GD results from abnormal microfibril assembly in tissues, and that ADAMTSL2 may limit the assembly of fibrillin microfibrils.


Asunto(s)
Proteínas ADAMTS/genética , Enfermedades del Desarrollo Óseo/genética , Extremidades/crecimiento & desarrollo , Eliminación de Gen , Deformidades Congénitas de las Extremidades/genética , Tendones/crecimiento & desarrollo , Proteínas ADAMTS/metabolismo , Animales , Animales Recién Nacidos , Modelos Animales de Enfermedad , Fibrilina-1/metabolismo , Fibrilina-2/metabolismo , Fibrilinas/metabolismo , Regulación del Desarrollo de la Expresión Génica , Humanos , Ratones , Especificidad de Órganos , Tendones/metabolismo
16.
Mol Autism ; 6: 63, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26579216

RESUMEN

BACKGROUND: Autism spectrum disorder (ASD) is a group of neurodevelopmental disorders characterized by impairment in social communication/interaction and inflexible/repetitive behavior. Several lines of evidence support genetic factors as a predominant cause of ASD. Among those autism susceptibility genes that have been identified, the PTEN tumor suppressor gene, initially identified as predisposing to Cowden heritable cancer syndrome, was found to be mutated in a subset of ASD patients with extreme macrocephaly. However, the ASD-relevant molecular mechanism mediating the effect of PTEN mutations remains elusive. METHODS: We developed a Pten knock-in murine model to study the effects of Pten germline mutations, specifically altering subcellular localization, in ASD. Proteins were isolated from the hemispheres of the male littermates, and Western blots were performed to determine protein expression levels of tyrosine hydroxylase (TH). Immunohistochemical stains were carried out to validate the localization of TH and dopamine D2 receptors (D2R). PC12 cells ectopically expressing either wild-type or missense mutant PTEN were then compared for the differences in TH expression. RESULTS: Mice carrying Pten mutations have high TH and D2R in the striatum and prefrontal cortex. They also have increased phosphorylation of cAMP response element-binding protein (CREB) and TH. Mechanistically, PTEN downregulates TH production in PC12 cells via inhibiting the phosphoinositide 3-kinase (PI3K)/CREB signaling pathway, while PTEN reduces TH phosphorylation via suppressing MAPK pathway. Unlike wild-type PTEN but similar to the mouse knock-in mutant Pten, three naturally occurring missense mutations of PTEN that we previously identified in ASD patients, H93R, F241S, and D252G, were not able to suppress TH when overexpressed in PC12 cells. In addition, two other PTEN missense mutations, C124S (pan phosphatase dead) and G129E (lipid phosphatase dead), failed to suppress TH when ectopically expressed in PC12 cells. CONCLUSIONS: Our data reveal a non-canonical PTEN-TH pathway in the brain that may work as a core regulator of dopamine signaling, which when dysfunctional is pathogenic in ASD.

17.
Fertil Steril ; 95(8): 2745-8, 2011 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-21536282

RESUMEN

In this study, the sperm protein profile was compared between fertile and infertile men using 2-dimensional gel electrophoresis, liquid chromatography mass spectrometer analysis, and matrix-assisted laser desorption ionization-time-of-flight-mass spectrometry. Four unique proteins, semenogelin II precursor, prolactin-induced protein, clusterin isoform 1, and prostate-specific antigen isoform 1 preproprotein, were predominantly present in the semen of healthy men; however, semenogelin II precursor and clusterin isoform 1 were not seen in the semen of infertile men, suggesting unique differences in the spermatozoa protein profiles of fertile and infertile men.


Asunto(s)
Fertilidad , Infertilidad Masculina/metabolismo , Proteómica , Proteínas de Plasma Seminal/análisis , Espermatozoides/química , Secuencia de Aminoácidos , Biomarcadores/análisis , Proteínas Portadoras/análisis , Estudios de Casos y Controles , Cromatografía de Fase Inversa , Clusterina/análisis , Electroforesis en Gel Bidimensional , Glicoproteínas/análisis , Humanos , Infertilidad Masculina/fisiopatología , Masculino , Proteínas de Transporte de Membrana , Peso Molecular , Ohio , Proyectos Piloto , Antígeno Prostático Específico/análisis , Proteómica/métodos , Proteínas de Plasma Seminal/química , Proteínas de Secreción de la Vesícula Seminal/análisis , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
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