RESUMEN
Reflux and recirculation in primary varicose veins are not yet completely understood, and the contribution of perforator veins is dual.Reflux origin was assessed as junctional (JP, reflux of the greater saphenous junction or groin recurrences) with/without suspect perforator veins (SPV), or perforator phenotype (PP, reflux from SPV only or for statistical purposes from the small saphenous vein). Flow direction and intensity were recorded under Valsalva (JP) or as spontaneous/under distal compression/decompression (SPV) and weighted with one/two points as reflux/reentry, respectively, in the case of SPV. We compared the origin and extent of axial reflux and diameter/flow direction of SPV with the clinical stage by multivariate analysis.Of 107 limbs, 68 presented with JP, 49 combined with SPV, and 39 with PP. CEAP C3-C6 was associated with the presence of SPV (JP and PP) in 45/65 (11/22) limbs with primaries (recurrences) or in 3/16 (0/4), p < 0.01 (p = 0.01), without SPV. C4-C6 at first manifestation, however, was more frequent in JP and axial reflux below the knee in 14/39 limbs (p = 0.01) or above the knee in 3/11 (p = 0.12) compared with PP (5/31). SPV flow at first manifestation was reentry in the case of JP and axial reflux below the knee (estimate -1.62, p = 0.02) or above the knee (0.29, p = 0.81) compared with PP, but diameter of the most dilated perforator vein was higher in the case of JP and axial reflux above the knee (estimate 0.20, p < 0.01) or below the knee (0.04, p = 0.30) compared with PP. Predominant SPV flow was reentry/reflux during peripheral compression/decompression, respectively (p = 0.009).The data suggest that the reflux origin and extent of axial reflux are associated with diameter/flow direction of SPV and clinical stage in primary varicose veins.
RESUMEN
MAD2L1BP-encoded p31comet mediates Trip13-dependent disassembly of Mad2- and Rev7-containing complexes and, through this antagonism, promotes timely spindle assembly checkpoint (SAC) silencing, faithful chromosome segregation, insulin signaling, and homology-directed repair (HDR) of DNA double-strand breaks. We identified a homozygous MAD2L1BP nonsense variant, R253*, in 2 siblings with microcephaly, epileptic encephalopathy, and juvenile granulosa cell tumors of ovary and testis. Patient-derived cells exhibited high-grade mosaic variegated aneuploidy, slowed-down proliferation, and instability of truncated p31comet mRNA and protein. Corresponding recombinant p31comet was defective in Trip13, Mad2, and Rev7 binding and unable to support SAC silencing or HDR. Furthermore, C-terminal truncation abrogated an identified interaction of p31comet with tp53. Another homozygous truncation, R227*, detected in an early-deceased patient with low-level aneuploidy, severe epileptic encephalopathy, and frequent blood glucose elevations, likely corresponds to complete loss of function, as in Mad2l1bp-/- mice. Thus, human mutations of p31comet are linked to aneuploidy and tumor predisposition.
Asunto(s)
Encefalopatías , Tumor de Células de la Granulosa , Neoplasias Ováricas , Femenino , Humanos , Animales , Ratones , Proteínas Mad2/genética , Proteínas Mad2/metabolismo , Tumor de Células de la Granulosa/genética , Mutación , AneuploidiaRESUMEN
Defects in primary or motile cilia result in a variety of human pathologies, and retinal degeneration is frequently associated with these so-called ciliopathies. We found that homozygosity for a truncating variant in CEP162, a centrosome and microtubule-associated protein required for transition zone assembly during ciliogenesis and neuronal differentiation in the retina, caused late-onset retinitis pigmentosa in 2 unrelated families. The mutant CEP162-E646R*5 protein was expressed and properly localized to the mitotic spindle, but it was missing from the basal body in primary and photoreceptor cilia. This impaired recruitment of transition zone components to the basal body and corresponded to complete loss of CEP162 function at the ciliary compartment, reflected by delayed formation of dysmorphic cilia. In contrast, shRNA knockdown of Cep162 in the developing mouse retina increased cell death, which was rescued by expression of CEP162-E646R*5, indicating that the mutant retains its role for retinal neurogenesis. Human retinal degeneration thus resulted from specific loss of the ciliary function of CEP162.
Asunto(s)
Degeneración Retiniana , Animales , Humanos , Ratones , Centrosoma/metabolismo , Cilios/metabolismo , Proteínas Asociadas a Microtúbulos/genética , Neurogénesis/genética , Retina/metabolismo , Degeneración Retiniana/metabolismoRESUMEN
Neonatal Marfan syndrome (nMFS) is a rare and severe form of Marfan syndrome (MFS) with a poor prognosis, that presents with a highly variable phenotype, particularly regarding skeletal, ocular, and cardiovascular manifestations. Mutations in the fibrillin-1 (FBN1) gene are known as the principal cause of MFS and MFS-related syndromes. Here, we report on a full-term female neonate with postnatal characteristics suggestive of nMFS, including severe cardiovascular disease resulting in cardiorespiratory failure and death by 4 mo of age. We identified a novel large genomic in-frame deletion of FBN1 exons 42-45, c.(5065 + 1_5066 - 1)_(5545 + 1_5546 - 1)del. Large FBN1 in-frame deletions between exons 24 and 53 have been associated with severe MFS. The deletion in our patient differs from the FBN1 region associated with the majority of nMFS cases, exons 24-32.
Asunto(s)
Síndrome de Marfan , Femenino , Humanos , Exones/genética , Fibrilina-1/genética , Síndrome de Marfan/genética , Mutación , Fenotipo , Eliminación de Secuencia/genéticaRESUMEN
Biallelic pathogenic variants of OTUD6B have recently been described to cause intellectual disability (ID) with seizures. Here, we report the clinical and molecular characterization of five additional patients (from two unrelated Egyptian families) with ID due to homozygous OTUD6B variants. In Family I, the two affected brothers had additional retinal degeneration, a symptom not yet reported in OTUD6B-related ID. Whole-exome sequencing (WES) identified a novel nonsense variant in OTUD6B (c.271C>T, p.(Gln91Ter)), but also a nonsense variant in RP1L1 (c.5959C>T, p.(Gln1987Ter)), all in homozygous state. Biallelic pathogenic variants in RP1L1 cause autosomal recessive retinitis pigmentosa type 88 (RP88). Thus, RP1L1 dysfunction likely accounts for the visual phenotype in this family with two simultaneous autosomal recessive disorders. In Family II, targeted sequencing revealed a novel homozygous missense variant (c.767G>T, p.(Gly256Val)), confirming the clinically suspected OTUD6B-related ID. Consistent with the clinical variability in previously reported OTUD6B patients, our patients showed inter- and intrafamilial differences with regard to the clinical and brain imaging findings. Interestingly, various orodental features were present including macrodontia, dental crowding, abnormally shaped teeth, and thick alveolar ridges. Broad distal phalanges (especially the thumbs and halluces) with prominent interphalangeal joints and fetal pads were recognized in all patients and hence considered pathognomonic. Our study extends the spectrum of the OTUD6B-associated phenotype. Retinal degeneration, albeit present in both patients from Family I, was shown to be unrelated to OTUD6B, demonstrating the need for in-depth analysis of WES data in consanguineous families to uncover simultaneous autosomal recessive disorders.
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Endopeptidasas/genética , Predisposición Genética a la Enfermedad , Discapacidad Intelectual/diagnóstico , Discapacidad Intelectual/genética , Mutación , Fenotipo , Alelos , Estudios de Asociación Genética , Genotipo , Humanos , Degeneración Retiniana/genética , Secuenciación del ExomaRESUMEN
Here, we report on six unrelated individuals, all presenting with early-onset global developmental delay, associated with impaired motor, speech and cognitive development, partly with developmental epileptic encephalopathy and physical dysmorphisms. All individuals carry heterozygous missense variants of KCND2, which encodes the voltage-gated potassium (Kv) channel α-subunit Kv4.2. The amino acid substitutions associated with the variants, p.(Glu323Lys) (E323K), p.(Pro403Ala) (P403A), p.(Val404Leu) (V404L) and p.(Val404Met) (V404M), affect sites known to be critical for channel gating. To unravel their likely pathogenicity, recombinant mutant channels were studied in the absence and presence of auxiliary ß-subunits under two-electrode voltage clamp in Xenopus oocytes. All channel mutants exhibited slowed and incomplete macroscopic inactivation, and the P403A variant in addition slowed activation. Co-expression of KChIP2 or DPP6 augmented the functional expression of both wild-type and mutant channels; however, the auxiliary ß-subunit-mediated gating modifications differed from wild type and among mutants. To simulate the putative setting in the affected individuals, heteromeric Kv4.2 channels (wild type + mutant) were studied as ternary complexes (containing both KChIP2 and DPP6). In the heteromeric ternary configuration, the E323K variant exhibited only marginal functional alterations compared to homomeric wild-type ternary, compatible with mild loss-of-function. By contrast, the P403A, V404L and V404M variants displayed strong gating impairment in the heteromeric ternary configuration, compatible with loss-of-function or gain-of-function. Our results support the etiological involvement of Kv4.2 channel gating impairment in early-onset monogenic global developmental delay. In addition, they suggest that gain-of-function mechanisms associated with a substitution of V404 increase epileptic seizure susceptibility.
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Discapacidades del Desarrollo/etiología , Discapacidades del Desarrollo/metabolismo , Variación Genética , Activación del Canal Iónico , Canales de Potasio Shal/genética , Canales de Potasio Shal/metabolismo , Alelos , Sustitución de Aminoácidos , Biomarcadores , Discapacidades del Desarrollo/diagnóstico , Susceptibilidad a Enfermedades , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Mutación , Fenotipo , Subunidades de Proteína , Canales de Potasio Shal/químicaRESUMEN
Antiphospholipid antibodies (aPLs) cause severe autoimmune disease characterized by vascular pathologies and pregnancy complications. Here, we identify endosomal lysobisphosphatidic acid (LBPA) presented by the CD1d-like endothelial protein C receptor (EPCR) as a pathogenic cell surface antigen recognized by aPLs for induction of thrombosis and endosomal inflammatory signaling. The engagement of aPLs with EPCR-LBPA expressed on innate immune cells sustains interferon- and toll-like receptor 7-dependent B1a cell expansion and autoantibody production. Specific pharmacological interruption of EPCR-LBPA signaling attenuates major aPL-elicited pathologies and the development of autoimmunity in a mouse model of systemic lupus erythematosus. Thus, aPLs recognize a single cell surface lipid-protein receptor complex to perpetuate a self-amplifying autoimmune signaling loop dependent on the cooperation with the innate immune complement and coagulation pathways.
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Presentación de Antígeno , Autoinmunidad , Coagulación Sanguínea/inmunología , Receptor de Proteína C Endotelial/inmunología , Lupus Eritematoso Sistémico/inmunología , Lisofosfolípidos/inmunología , Monoglicéridos/inmunología , Animales , Anticuerpos Antifosfolípidos/biosíntesis , Autoanticuerpos/biosíntesis , Modelos Animales de Enfermedad , Pérdida del Embrión/inmunología , Endosomas/inmunología , Receptor de Proteína C Endotelial/genética , Humanos , Inmunidad Innata , Lupus Eritematoso Sistémico/sangre , Ratones , Ratones Mutantes , Esfingomielina Fosfodiesterasa/metabolismo , Trombosis/inmunología , Receptor Toll-Like 7/inmunologíaRESUMEN
BACKGROUND: Patients with head and neck squamous cell carcinoma (HNSCC) can develop lung squamous cell carcinoma (LuSCC), which could be the second primary tumor or HNSCC metastasis. Morphologically it is difficult to distinguish metastatic HNSCC from a second primary tumor which presents a significant diagnostic challenge. Differentiation of those two malignancies is important because the recommended treatments for metastatic HNSCC and primary LuSCC differ significantly. We investigated if the quantification of the promotor methylation status in HNSCC and LuSCC differs. METHODS: Primary HNSCC (N = 36) and LuSCC (N = 17) were included in this study. Methylation status in the ASC/TMS1/PYCARD (apoptosis-associated speck-like protein containing a caspase recruitment domain; 8 CpG sites) and MyD88 (Myeloid differentiation primary response protein 88; 10 CpG sites) promoters was analyzed. Bisulfite converted DNA, isolated from tumor tissue was quantified using pyrosequencing. Results of pyrosequencing analysis were expressed as a percentage for each tested CpG site. Receiver-operating characteristic (ROC) curve analysis was used for the evaluation of the diagnostic properties of selected biomarkers. RESULTS: CpG sites located in the promoters of ASC/TMS1/PYCARD_CpG8 (- 65 upstream) and MyD88_CpG4 (- 278 upstream) are significantly hypermethylated in the HNSCC when compared with LuSCC (p ≤ 0.0001). By performing ROC curve analysis we showed that corresponding areas under the curve (AUC) were 85-95%, indicating that selected CpG sites are useful for a distinction between primary LuSCC and primary HNSCC. CONCLUSIONS: Results of the present study indicate that there is a significant difference in the methylation status of tested genes between primary HNSCC and LuSCC. However, to prove this approach as a useful tool for distinguishing second primary LuSCC from HNSCC metastasis, it would be necessary to include a larger number of samples, and most importantly, metastatic samples.
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Islas de CpG/genética , Regulación Neoplásica de la Expresión Génica/genética , Neoplasias de Cabeza y Cuello/genética , Factor 88 de Diferenciación Mieloide/genética , Carcinoma de Células Escamosas de Cabeza y Cuello/genética , Proteínas Adaptadoras Transductoras de Señales/genética , Adulto , Anciano , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patología , Epigénesis Genética/genética , Femenino , Neoplasias de Cabeza y Cuello/patología , Humanos , Neoplasias Pulmonares/genética , Masculino , Persona de Mediana Edad , Factor 88 de Diferenciación Mieloide/metabolismo , Regiones Promotoras Genéticas/genética , Carcinoma de Células Escamosas de Cabeza y Cuello/patologíaRESUMEN
Inherited retinal dystrophies (IRDs) are characterized by high clinical and genetic heterogeneity. A precise characterization is desirable for diagnosis and has impact on prognosis, patient counseling, and potential therapeutic options. Here, we demonstrate the effectiveness of the combination of in-depth retinal phenotyping and molecular genetic testing in complex pedigrees with different IRDs. Four affected Caucasians and two unaffected relatives were characterized including multimodal retinal imaging, functional testing, and targeted next-generation sequencing. A considerable intrafamilial phenotypic and genotypic heterogeneity was identified. While the parents of the index family presented with rod-cone dystrophy and ABCA4-related retinopathy, their two sons revealed characteristics in the spectrum of incomplete congenital stationary night blindness and ocular albinism, respectively. Molecular testing revealed previously described variants in RHO, ABCA4, and MITF as well as a novel variant in CACNA1F. Identified variants were verified by intrafamilial co-segregation, bioinformatic annotations, and in silico analysis. The coexistence of four independent IRDs caused by distinct mutations and inheritance modes in one pedigree is demonstrated. These findings highlight the complexity of IRDs and underscore the need for the combination of extensive molecular genetic testing and clinical characterization. In addition, a novel variant in the CACNA1F gene is reported associated with incomplete congenital stationary night blindness.
Asunto(s)
Transportadoras de Casetes de Unión a ATP/genética , Albinismo Ocular/diagnóstico , Canales de Calcio Tipo L/genética , Distrofias de Conos y Bastones/diagnóstico , Enfermedades Hereditarias del Ojo/diagnóstico , Enfermedades Genéticas Ligadas al Cromosoma X/diagnóstico , Factor de Transcripción Asociado a Microftalmía/genética , Miopía/diagnóstico , Ceguera Nocturna/diagnóstico , Adolescente , Albinismo Ocular/genética , Niño , Distrofias de Conos y Bastones/genética , Enfermedades Hereditarias del Ojo/genética , Femenino , Angiografía con Fluoresceína , Enfermedades Genéticas Ligadas al Cromosoma X/genética , Pruebas Genéticas , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Masculino , Persona de Mediana Edad , Mutación , Miopía/genética , Ceguera Nocturna/genética , Padres , Linaje , Fenotipo , Polimorfismo de Nucleótido Simple , Análisis de Secuencia de ADNRESUMEN
Mutations in the actively expressed, maternal allele of the imprinted KCNK9 gene cause Birk-Barel intellectual disability syndrome (BBIDS). Using a BBIDS mouse model, we identify here a partial rescue of the BBIDS-like behavioral and neuronal phenotypes mediated via residual expression from the paternal Kcnk9 (Kcnk9pat) allele. We further demonstrate that the second-generation HDAC inhibitor CI-994 induces enhanced expression from the paternally silenced Kcnk9 allele and leads to a full rescue of the behavioral phenotype suggesting CI-994 as a promising molecule for BBIDS therapy. Thus, these findings suggest a potential approach to improve cognitive dysfunction in a mouse model of an imprinting disorder.
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Anomalías Craneofaciales/genética , Anomalías Craneofaciales/metabolismo , Histonas/metabolismo , Discapacidad Intelectual/genética , Discapacidad Intelectual/metabolismo , Hipotonía Muscular/genética , Hipotonía Muscular/metabolismo , Canales de Potasio/genética , Animales , Conducta Animal , Benzamidas , Encéfalo/metabolismo , Anomalías Craneofaciales/tratamiento farmacológico , Modelos Animales de Enfermedad , Femenino , Técnicas de Silenciamiento del Gen , Impresión Genómica , Inhibidores de Histona Desacetilasas/farmacología , Humanos , Discapacidad Intelectual/tratamiento farmacológico , Locus Coeruleus/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Hipotonía Muscular/tratamiento farmacológico , Mutación , Fenotipo , Fenilendiaminas/farmacología , Canales de Potasio/deficiencia , Canales de Potasio/metabolismo , Regulación hacia Arriba/efectos de los fármacosRESUMEN
We previously reported that inactivation of the transmembrane taurine transporter (TauT or solute carrier 6a6) causes early retinal degeneration in mice. Compatible with taurine's indispensability for cell volume homeostasis, protein stabilization, cytoprotection, antioxidation, and immuno- and neuromodulation, mice develop multisystemic dysfunctions (hearing loss; liver fibrosis; and behavioral, heart, and skeletal muscle abnormalities) later on. Here, by genetic, cell biologic, in vivo1H-magnetic resonance spectroscopy and molecular dynamics simulation studies, we conducted in-depth characterization of a novel disorder: human TAUT deficiency. Loss of TAUT function due to a homozygous missense mutation caused panretinal degeneration in 2 brothers. TAUTp.A78E still localized in the plasma membrane but is predicted to impact structural stabilization. 3H-taurine uptake by peripheral blood mononuclear cells was reduced by 95%, and taurine levels were severely reduced in plasma, skeletal muscle, and brain. Extraocular dysfunctions were not yet detected, but significantly increased urinary excretion of 8-oxo-7,8-dihydroguanosine indicated generally enhanced (yet clinically unapparent) oxidative stress and RNA oxidation, warranting continuous broad surveillance.-Preising, M. N., Görg, B., Friedburg, C., Qvartskhava, N., Budde, B. S., Bonus, M., Toliat, M. R., Pfleger, C., Altmüller, J., Herebian, D., Beyer, M., Zöllner, H. J., Wittsack, H.-J., Schaper, J., Klee, D., Zechner, U., Nürnberg, P., Schipper, J., Schnitzler, A., Gohlke, H., Lorenz, B., Häussinger, D., Bolz, H. J. Biallelic mutation of human SLC6A6 encoding the taurine transporter TAUT is linked to early retinal degeneration.
Asunto(s)
Glicoproteínas de Membrana/genética , Proteínas de Transporte de Membrana/genética , Mutación Missense/genética , Degeneración Retiniana/metabolismo , Taurina/metabolismo , Transporte Biológico/fisiología , Membrana Celular/metabolismo , Células Cultivadas , Guanosina/análogos & derivados , Guanosina/metabolismo , Humanos , Leucocitos Mononucleares/metabolismo , Músculo Esquelético/metabolismo , Estrés Oxidativo/fisiologíaRESUMEN
Human spermatogonial stem cells (hSSCs) have potential in fertility preservation of prepubertal boys or in treatment of male adults suffering from meiotic arrest. Prior to therapeutic application, in vitro propagation of rare hSSCs is mandatory. As the published data points to epigenetic alterations in long-term cell culture of spermatogonia (SPG), an initial characterisation of their DNA methylation state is important. Testicular biopsies from five adult normogonadotropic patients were converted into aggregate-free cell suspensions. FGFR3-positive (FGFR3+) SPG, resembling a very early stem cell state, were labelled with magnetic beads and isolated in addition to unlabelled SPG (FGFR3-). DNA methylation was assessed by limiting dilution bisulfite pyrosequencing for paternally imprinted (H19 and MEG3), maternally imprinted (KCNQ1OT1, PEG3, and SNRPN), pluripotency (POU5F1/OCT4 and NANOG), and spermatogonial/hSSC marker (FGFR3, GFRA1, PLZF, and L1TD1) genes on either single cells or pools of 10 cells. Both spermatogonial subpopulations exhibited a methylation pattern largely equivalent to sperm, with hypomethylation of hSSC marker and maternally imprinted genes and hypermethylation of pluripotency and paternally imprinted genes. Interestingly, we detected fine differences between the two spermatogonial subpopulations, which were reflected by an inverse methylation pattern of imprinted genes, i.e. decreasing methylation in hypomethylated genes and increasing methylation in hypermethylated genes, from FGFR3+ through FGFR3- SPG to sperm. Limitations of this study are due to it not being performed on a genome-wide level and being based on previously published regulatory gene regions. However, the concordance of DNA methylation between SPG and sperm implies that hSSC regulation and germ cell differentiation do not occur at the DNA methylation level.
Asunto(s)
Metilación de ADN/fisiología , Espermatogonias/metabolismo , Alelos , Diferenciación Celular/genética , Diferenciación Celular/fisiología , Metilación de ADN/genética , Epigénesis Genética/genética , Humanos , Masculino , Receptor Tipo 3 de Factor de Crecimiento de Fibroblastos/genética , Espermatogénesis/genética , Espermatogénesis/fisiología , Espermatozoides/metabolismo , Células Madre/metabolismoRESUMEN
BACKGROUND: Lung cancer is the leading cause of cancer-related death worldwide, with 5-year overall survival less than 15%. Therefore, it is essential to find biomarkers for early detection and prognosis. Aberrant DNA methylation is a common feature of human cancers and its utility is already recognized in cancer management. The aim of this study was to explore the diagnostic and prognostic value of the promoter methylation status of the ASC/TMS1/PYCARD and MyD88 genes, key adaptor molecules in the activation of the innate immune response and apoptosis pathways. METHODS: A total of 50 non-small cell lung cancer (NSCLC) patients were enrolled in the study. Methylation of bisulphite converted DNA was quantified by pyrosequencing in fresh frozen malignant tissues and adjacent non-malignant tissues. Associations between methylation and lung function, tumor grade and overall survival were evaluated using receiver-operating characteristics (ROC) analysis and statistical tests of hypothesis. RESULTS: Methylation level of tested genes is generally low but significantly decreased in tumor tissues (ASC/TMS1/PYCARD, P<0.0001; MyD88, P<0.0002), which correlates with increased protein expression. Three CpG sites were identified as promising diagnostic marker candidates; CpG11 (-63 position) in ASC/TMS1/PYCARD and CpG1 (-253 position) and 2 (-265 position) in MyD88. The association study showed that the methylation status of the ASC/TMS1 CpG4 site (-34 position) in malignant and non-malignant tissues is associated with the overall survival (P=0.019) and the methylation status of CpG8 site (-92 position) is associated with TNM-stage (P=0.011). CONCLUSIONS: The methylation status of the ASC/TMS1/PYCARD and MyD88 promoters are promising prognostic biomarker candidates. However, presented results should be considered as a preliminary and should be confirmed on the larger number of the samples.
RESUMEN
Although an essential component of assisted reproductive technologies, ovarian stimulation, or superovulation, may interfere with the epigenetic reprogramming machinery during early embryogenesis and gametogenesis. To investigate the possible impact of superovulation particularly on the methylation reprogramming process directly after fertilization, we performed immunofluorescence staining of pronuclear (PN) stage embryos with antibodies against 5mC and 5hmC. PN stage embryos obtained by superovulation displayed an increased incidence of abnormal methylation and hydroxymethylation patterns in both maternal and paternal pronuclear DNA. Subsequent single-cell RT-qPCR analyses of the Tet1, Tet2, and Tet3 genes revealed no significant expression differences between PN stage embryos from spontaneously and superovulated matings that could be causative for the abnormal methylation and hydroxymethylation patterns. To analyze the possible contribution of TET-independent replication-associated demethylation mechanisms, we then determined the 5mC and 5hmC levels of PN stage mouse embryos using immunofluorescence analyses after inhibition of DNA replication with aphidicolin. Inhibition of DNA replication had no effect on abnormal methylation and hydroxymethylation patterns that still persisted in the superovulated group. Interestingly, the onset of DNA replication, which was also analyzed in these experiments, was remarkably delayed in the superovulated group. Our findings imply an impact of superovulation on both replication-dependent and -independent or yet unknown demethylation mechanisms in PN stage mouse embryos. In addition, they reveal for the first time a negative effect of superovulation on the initiation of DNA replication in PN stage mouse embryos.
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Haplotypes of the Gabra2 gene encoding the α2-subunit of the GABAA receptor (GABAAR) are associated with drug abuse, suggesting that α2-GABAARs may play an important role in the circuitry underlying drug misuse. The genetic association of Gabra2 haplotypes with cocaine addiction appears to be evident primarily in individuals who had experienced childhood trauma. Given this association of childhood trauma, cocaine abuse and the Gabra2 haplotypes, we have explored in a mouse model of early life adversity (ELA) whether such events influence the behavioral effects of cocaine and if, as suggested by the human studies, α2-GABAARs in the nucleus accumbens (NAc) are involved in these perturbed behaviors. In adult mice prior ELA caused a selective decrease of accumbal α2-subunit mRNA, resulting in a selective decrease in the number and size of the α2-subunit (but not the α1-subunit) immunoreactive clusters in NAc core medium spiny neurons (MSNs). Functionally, in adult MSNs ELA decreased the amplitude and frequency of GABAAR-mediated miniature inhibitory postsynaptic currents (mIPSCs), a profile similar to that of α2 "knock-out" (α2-/-) mice. Behaviourally, adult male ELA and α2-/- mice exhibited an enhanced locomotor response to acute cocaine and blunted sensitisation upon repeated cocaine administration, when compared to their appropriate controls. Collectively, these findings reveal a neurobiological mechanism which may relate to the clinical observation that early trauma increases the risk for substance abuse disorder (SAD) in individuals harbouring haplotypic variations in the Gabra2 gene.
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Cocaína/farmacología , Locomoción/efectos de los fármacos , Núcleo Accumbens/efectos de los fármacos , Núcleo Accumbens/fisiología , Receptores de GABA-A/biosíntesis , Animales , Sensibilización del Sistema Nervioso Central/fisiología , Femenino , Potenciales Postsinápticos Inhibidores/fisiología , Masculino , Ratones , Ratones Noqueados , Potenciales Postsinápticos Miniatura/fisiología , Neuronas/metabolismo , Neuronas/fisiología , Núcleo Accumbens/metabolismo , Receptores de GABA-A/genética , Receptores de GABA-A/metabolismo , Estrés Fisiológico/efectos de los fármacos , Estrés Fisiológico/fisiologíaRESUMEN
BACKGROUND: Many of the genetic childhood disorders leading to death in the pre- or neonatal period or during early childhood follow autosomal recessive modes of inheritance and bear specific challenges for genetic counseling and prenatal diagnostics. Parents are carriers but clinically unaffected, and diseases are rare but have recurrence risks of 25% in the same family. Often, affected children (or fetuses) die before a genetic diagnosis can be established, post-mortem analysis and phenotypic descriptions are insufficient and DNA from affected fetuses or children is not available for later analysis. A genetic diagnosis showing biallelic causative mutations is, however, the requirement for targeted carrier testing in parents and prenatal and preimplantation genetic diagnosis in further pregnancies. METHODS: We undertook targeted next-generation sequencing (NGS) for carrier screening of autosomal recessive lethal disorders in 8 consanguineous and 5 non-consanguineous couples with one or more affected children. We searched for heterozygous variants (non-synonymous coding or splice variants) in parents' DNA, using a set of 430 genes known to be causative for rare autosomal recessive diseases with poor prognosis, and then filtering for variants present in genes overlapping in both partners. Putative pathogenic variants were tested for cosegregation in affected fetuses or children where material was available. RESULTS: The diagnosis for the premature death in children was established in 5 of the 13 couples. Out of the 8 couples in which no causative diagnosis could be established 4 consented to undergo further analysis, in two of those a potentially causative variant in a novel candidate gene was identified. CONCLUSIONS: For the families in whom causative variants could be identified, these may now be used for prenatal and preimplantation genetic diagnostics. Our data show that NGS based gene panel sequencing of selected genes involved in lethal autosomal recessive disorders is an effective tool for carrier screening in parents and for the identification of recessive gene defects and offers the possibility of prenatal and preimplantation genetic diagnosis in further pregnancies in families that have experienced deaths in early childhood and /or multiple abortions.
Asunto(s)
Genes Recesivos/genética , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Femenino , Humanos , Masculino , Análisis por Micromatrices/métodos , LinajeRESUMEN
Poorly differentiated thyroid carcinoma (PDTC) is a rare malignancy with higher mortality than well-differentiated thyroid carcinoma. The histological diagnosis can be difficult as well as the therapy. Improved diagnosis and new targeted therapies require knowledge of DNA sequence changes in cancer-relevant genes. The TruSeq Amplicon Cancer Panel was used to screen cancer genomes from 25 PDTC patients for somatic single-nucleotide variants in 48 genes known to represent mutational hotspots. A total of 4490 variants were found in 23 tissue samples of PDTC. Ninety-eight percent (4392) of these variants did not meet the inclusion criteria, while 98 potentially pathogenic or pathogenic variants remained after filtering. These variants were distributed over 33 genes and were all present in a heterozygous state. Five tissue samples harboured not a single variant. Predominantly, variants in P53 (43% of tissue samples) were identified, while less frequently, variants in APC, ERBB4, FLT3, KIT, SMAD4 and BRAF (each in 17% of tissue samples) as well as ATM, EGFR and FBXW7 (each in 13% of tissue samples) were observed. This study identified new potential genetic targets for further research in PDTC. Of particular interest are four observed ERBB4 (alias HER4) variants, which have not been connected to this type of thyroid carcinoma so far. In addition, APC and SMAD4 mutations have not been reported in this subtype of cancer either. In contrast to other reports, we did not find CTNNB1 variants.
RESUMEN
The transcription repressor FOXP2 is a crucial player in nervous system evolution and development of humans and songbirds. In order to provide an additional insight into its functional role we compared target gene expression levels between human neuroblastoma cells (SH-SY5Y) stably overexpressing FOXP2 cDNA of either humans or the common chimpanzee, Rhesus monkey, and marmoset, respectively. RNA-seq led to identification of 27 genes with differential regulation under the control of human FOXP2, which were previously reported to have FOXP2-driven and/or songbird song-related expression regulation. RT-qPCR and Western blotting indicated differential regulation of additional 13 new target genes in response to overexpression of human FOXP2. These genes may be directly regulated by FOXP2 considering numerous matches of established FOXP2-binding motifs as well as publicly available FOXP2-ChIP-seq reads within their putative promoters. Ontology analysis of the new and reproduced targets, along with their interactors in a network, revealed an enrichment of terms relating to cellular signaling and communication, metabolism and catabolism, cellular migration and differentiation, and expression regulation. Notably, terms including the words "neuron" or "axonogenesis" were also enriched. Complementary literature screening uncovered many connections to human developmental (autism spectrum disease, schizophrenia, Down syndrome, agenesis of corpus callosum, trismus-pseudocamptodactyly, ankyloglossia, facial dysmorphology) and neurodegenerative diseases and disorders (Alzheimer's, Parkinson's, and Huntington's diseases, Lewy body dementia, amyotrophic lateral sclerosis). Links to deafness and dyslexia were detected, too. Such relations existed for single proteins (e.g., DCDC2, NURR1, PHOX2B, MYH8, and MYH13) and groups of proteins which conjointly function in mRNA processing, ribosomal recruitment, cell-cell adhesion (e.g., CDH4), cytoskeleton organization, neuro-inflammation, and processing of amyloid precursor protein. Conspicuously, many links pointed to an involvement of the FOXP2-driven network in JAK/STAT signaling and the regulation of the ezrin-radixin-moesin complex. Altogether, the applied phylogenetic perspective substantiated FOXP2's importance for nervous system development, maintenance, and functioning. However, the study also disclosed new regulatory pathways that might prove to be useful for understanding the molecular background of the aforementioned developmental disorders and neurodegenerative diseases.