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1.
Clin Genet ; 105(5): 499-509, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38221796

RESUMO

Hao-Fountain syndrome (HAFOUS, OMIM: #616863) is a neurodevelopmental disorder caused by pathogenic variants in the gene USP7 coding for USP7, a protein involved in several crucial cellular homeostatic mechanisms and the recently described MUST complex. The phenotype of HAFOUS is insufficiently understood, yet there is a great need to better understand the spectrum of disease, genotype-phenotype correlations, and disease trajectories. We now present a larger cohort of 32 additional individuals and provide further clinical information about six previously reported individuals. A questionnaire-based study was performed to characterize the phenotype of Hao-Fountain syndrome more clearly, to highlight new traits, and to better distinguish the disease from related neurodevelopmental disorders. In addition to confirming previously described features, we report hyperphagia and increased body weight in a subset of individuals. HAFOUS patients present an increased rate of birth complications, congenital anomalies, and abnormal pain thresholds. Speech impairment emerges as a potential hallmark of Hao-Fountain syndrome. Cognitive testing reports reveal borderline intellectual functioning on average, although some individuals score in the range of intellectual disability. Finally, we created a syndrome-specific severity score. This score neither indicates a sex- nor age-specific difference of clinical severity, yet highlights a more severe outcome when amino acid changes colocalize to the catalytic domain of the USP7 protein.


Assuntos
Anormalidades Múltiplas , Doenças do Desenvolvimento Ósseo , Anormalidades Craniofaciais , Surdez , Deficiência Intelectual , Transtornos do Neurodesenvolvimento , Humanos , Peptidase 7 Específica de Ubiquitina/genética , Deficiência Intelectual/genética , Deficiência Intelectual/complicações , Anormalidades Múltiplas/genética , Anormalidades Craniofaciais/genética , Transtornos do Neurodesenvolvimento/genética , Fenótipo
2.
Genet Med ; 26(3): 101050, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38126281

RESUMO

PURPOSE: Hao-Fountain syndrome (HAFOUS) is a neurodevelopmental disorder caused by pathogenic variants in USP7. HAFOUS is characterized by developmental delay, intellectual disability, speech delay, behavioral abnormalities, autism spectrum disorder, seizures, hypogonadism, and mild dysmorphic features. We investigated the phenotype of 18 participants with HAFOUS and performed DNA methylation (DNAm) analysis, aiming to generate a diagnostic biomarker. Furthermore, we performed comparative analysis with known episignatures to gain more insight into the molecular pathophysiology of HAFOUS. METHODS: We assessed genomic DNAm profiles of 18 individuals with pathogenic variants and variants of uncertain significance (VUS) in USP7 to map and validate a specific episignature. The comparison between the USP7 cohort and 56 rare genetic disorders with earlier reported DNAm episignatures was performed with statistical and functional correlation. RESULTS: We mapped a sensitive and specific DNAm episignature for pathogenic variants in USP7 and utilized this to reclassify the VUS. Comparative epigenomic analysis showed evidence of HAFOUS similarity to a number of other rare genetic episignature disorders. CONCLUSION: We discovered a sensitive and specific DNAm episignature as a robust diagnostic biomarker for HAFOUS that enables VUS reclassification in USP7. We also expand the phenotypic spectrum of 9 new and 5 previously reported individuals with HAFOUS.


Assuntos
Anormalidades Múltiplas , Transtorno do Espectro Autista , Doenças do Desenvolvimento Ósseo , Anormalidades Craniofaciais , Surdez , Deficiência Intelectual , Transtornos do Neurodesenvolvimento , Humanos , Metilação de DNA/genética , Transtorno do Espectro Autista/genética , Peptidase 7 Específica de Ubiquitina/genética , Epigenômica , Deficiência Intelectual/genética , Deficiência Intelectual/diagnóstico , Transtornos do Neurodesenvolvimento/genética , Fenótipo , Biomarcadores
3.
medRxiv ; 2023 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-37503210

RESUMO

The value of computer-assisted image analysis has been shown in several studies. The performance of tools with artificial intelligence (AI), such as GestaltMatcher, is improved with the size and diversity of the training set, but properly labeled training data is currently the biggest bottleneck in developing next-generation phenotyping (NGP) applications. Therefore, we developed GestaltMatcher Database (GMDB) - a database for machine-readable medical image data that complies with the FAIR principles and improves the openness and accessibility of scientific findings in Medical Genetics. An entry in GMDB consists of a medical image such as a portrait, X-ray, or fundoscopy, and machine-readable meta information such as a clinical feature encoded in HPO terminology or a disease-causing mutation reported in HGVS format. In the beginning, data was mainly collected by curators gathering images from the literature. Currently, clinicians and individuals recruited from patient support groups provide their previously unpublished data. For this patient-centered approach, we developed a digital consent form. GMDB is a modern publication medium for case reports that complements preprints, e.g., on medRxiv. To enable inter-cohort comparisons, we implemented a research feature in GMDB that computes the pairwise syndromic similarity between hand-picked cases. Through a community-driven effort, we compiled an image collection of over 7,533 cases with 792 disorders in GMDB. Most of the data was collected from 2,058 publications. In addition, about 1,018 frontal images of 498 previously unpublished cases were obtained. The web interface enables gene- and phenotype-centered queries or infinite scrolls in the gallery. Digital consent has led to increasing adoption of the approach by patients. The research app within GMDB was used to generate syndromic similarity matrices to characterize two novel phenotypes (CSNK2B, PSMC3). GMDB is the first FAIR database for NGP, where data are findable, accessible, interoperable, and reusable. It is a repository for medical images that cannot be included in medRxiv. That means GMDB connects clinicians with a shared interest in particular phenotypes and improves the performance of AI.

4.
Am J Med Genet A ; 188(9): 2627-2636, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35789103

RESUMO

We present the phenotypes of seven previously unreported patients with Marbach-Schaaf neurodevelopmental syndrome, all carrying the same recurrent heterozygous missense variant c.1003C>T (p.Arg335Trp) in PRKAR1B. Clinical features of this cohort include global developmental delay and reduced sensitivity to pain, as well as behavioral anomalies. Only one of the seven patients reported here was formally diagnosed with autism spectrum disorder (ASD), while ASD-like features were described in others, overall indicating a lower prevalence of ASD in Marbach-Schaaf neurodevelopmental syndrome than previously assumed. The clinical spectrum of the current cohort is similar to that reported in the initial publication, delineating a complex developmental disorder with behavioral and neurologic features. PRKAR1B encodes the regulatory subunit R1ß of the protein kinase A complex (PKA), and is expressed in the adult and embryonal central nervous system in humans. PKA is crucial to a plethora of cellular signaling pathways, and its composition of different regulatory and catalytic subunits is cell-type specific. We discuss potential molecular disease mechanisms underlying the patients' phenotypes with respect to the different known functions of PKA in neurons, and the phenotypes of existing R1ß-deficient animal models.


Assuntos
Transtorno do Espectro Autista , Transtornos do Neurodesenvolvimento , Adulto , Animais , Transtorno do Espectro Autista/genética , Estudos de Coortes , Humanos , Transtornos do Neurodesenvolvimento/genética , Fenótipo , Síndrome
5.
Front Cell Dev Biol ; 10: 1020609, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36726590

RESUMO

In 2016 and 2018, Chung, Jansen and others described a new syndrome caused by haploinsufficiency of PHIP (pleckstrin homology domain interacting protein, OMIM *612,870) and mainly characterized by developmental delay (DD), learning difficulties/intellectual disability (ID), behavioral abnormalities, facial dysmorphism and obesity (CHUJANS, OMIM #617991). So far, PHIP alterations appear to be a rare cause of DD/ID. "Omics" technologies such as exome sequencing or array analyses have led to the identification of distinct types of alterations of PHIP, including, truncating variants, missense substitutions, splice variants and large deletions encompassing portions of the gene or the entire gene as well as adjacent genomic regions. We collected clinical and genetic data of 23 individuals with PHIP-associated Chung-Jansen syndrome (CHUJANS) from all over Europe. Follow-up investigations (e.g. Sanger sequencing, qPCR or Fluorescence-in-situ-Hybridization) and segregation analysis showed either de novo occurrence or inheritance from an also (mildly) affected parent. In accordance with previously described patients, almost all individuals reported here show developmental delay (22/23), learning disability or ID (22/23), behavioral abnormalities (20/23), weight problems (13/23) and characteristic craniofacial features (i.e. large ears/earlobes, prominent eyebrows, anteverted nares and long philtrum (23/23)). To further investigate the facial gestalt of individuals with CHUJANS, we performed facial analysis using the GestaltMatcher approach. By this, we could establish that PHIP patients are indistinguishable based on the type of PHIP alteration (e.g. missense, loss-of-function, splice site) but show a significant difference to the average face of healthy individuals as well as to individuals with Prader-Willi syndrome (PWS, OMIM #176270) or with a CUL4B-alteration (Intellectual developmental disorder, X-linked, syndromic, Cabezas type, OMIM #300354). Our findings expand the mutational and clinical spectrum of CHUJANS. We discuss the molecular and clinical features in comparison to the published individuals. The fact that some variants were inherited from a mildly affected parent further illustrates the variability of the associated phenotype and outlines the importance of a thorough clinical evaluation combined with genetic analyses for accurate diagnosis and counselling.

6.
J Pathol ; 255(3): 270-284, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34309874

RESUMO

Activation of the mechanistic target of rapamycin (mTOR) pathway is frequently found in cancer, but mTOR inhibitors have thus far failed to demonstrate significant antiproliferative efficacy in the majority of cancer types. Besides cancer cell-intrinsic resistance mechanisms, it is conceivable that mTOR inhibitors impact on non-malignant host cells in a manner that ultimately supports resistance of cancer cells. Against this background, we sought to analyze the functional consequences of mTOR inhibition in hepatocytes for the growth of metastatic colon cancer. To this end, we established liver epithelial cell (LEC)-specific knockout (KO) of mTOR (mTORLEC ) mice. We used these mice to characterize the growth of colorectal liver metastases with or without partial hepatectomy to model different clinical settings. Although the LEC-specific loss of mTOR remained without effect on metastasis growth in intact liver, partial liver resection resulted in the formation of larger metastases in mTORLEC mice compared with wildtype controls. This was accompanied by significantly enhanced inflammatory activity in LEC-specific mTOR KO livers after partial liver resection. Analysis of NF-ĸB target gene expression and immunohistochemistry of p65 displayed a significant activation of NF-ĸB in mTORLEC mice, suggesting a functional importance of this pathway for the observed inflammatory phenotype. Taken together, we show an unexpected acceleration of liver metastases upon deletion of mTOR in LECs. Our results support the notion that non-malignant host cells can contribute to resistance against mTOR inhibitors and encourage testing whether anti-inflammatory drugs are able to improve the efficacy of mTOR inhibitors for cancer therapy. © 2021 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.


Assuntos
Neoplasias do Colo/patologia , Hepatócitos/metabolismo , Neoplasias Hepáticas/secundário , Serina-Treonina Quinases TOR/metabolismo , Animais , Neoplasias Hepáticas/metabolismo , Camundongos , Camundongos Knockout , Metástase Neoplásica/patologia
7.
Clin Genet ; 100(3): 298-307, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34013972

RESUMO

Short stature is a common phenotype in children with Schaaf-Yang syndrome (SYS). Prader-Willi syndrome (PWS) and SYS share several phenotypic features including short stature, muscular hypotonia and developmental delay/intellectual disability. Evidence exists that similar to PWS, growth hormone (GH) deficiency may also be a feature of SYS. Recombinant human GH (rhGH) therapy has been approved for PWS, but the effects of rhGH therapy in individuals with SYS have not yet been documented. This retrospective, questionnaire-based study analyzes the prevalence of rhGH therapy in children with SYS, the effects of rhGH therapy on anthropometric measures, and parental perception of the treatment. Twenty-six individuals with SYS were sent a clinical questionnaire and a request for growth charts. We found a significant increase in height z-score (p* = 0.04) as well as a significant decrease in body mass index 6 months after rhGH therapy initiation (p* = 0.04). Furthermore, height z-scores of the treated group (mean z-score = -1.00) were significantly higher than those of the untreated group (mean z-score = -3.36, p = 0.01) at time of enrollment. All parents reported an increase in muscle strength and endurance, and several families noted beneficial effects such as improved cognition and motor development.


Assuntos
Anormalidades Múltiplas/tratamento farmacológico , Tamanho Corporal/efeitos dos fármacos , Transtornos do Crescimento/tratamento farmacológico , Hormônio do Crescimento Humano/uso terapêutico , Anormalidades Múltiplas/genética , Adolescente , Composição Corporal/efeitos dos fármacos , Criança , Pré-Escolar , Revisão de Uso de Medicamentos , Feminino , Hormônio do Crescimento Humano/efeitos adversos , Humanos , Lactente , Recém-Nascido , Masculino , Proteínas Recombinantes/efeitos adversos , Proteínas Recombinantes/uso terapêutico , Estudos Retrospectivos , Inquéritos e Questionários , Síndrome
8.
Radiographics ; 41(1): 8-31, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33337967

RESUMO

Acute chest pain is a common reason for visits to the emergency department. It is important to distinguish among the various causes of acute chest pain, because treatment and prognosis are substantially different among the various conditions. It is critical to exclude acute coronary syndrome (ACS), which is a major cause of hospitalization, death, and health care costs worldwide. Myocardial ischemia is defined as potential myocyte death secondary to an imbalance between oxygen supply and demand due to obstruction of an epicardial coronary artery. Unobstructed coronary artery disease can have cardiac causes (eg, myocarditis, myocardial infarction with nonobstructed coronary arteries, and Takotsubo cardiomyopathy), and noncardiac diseases can manifest with acute chest pain and increased serum cardiac biomarker levels. In the emergency department, cardiac MRI may aid in the identification of patients with non-ST-segment elevation myocardial infarction or unstable angina or ACS with unobstructed coronary artery disease, if the patient's clinical history is known to be atypical. Also, cardiac MRI is excellent for risk stratification of patients for adverse left ventricular remodeling or major adverse cardiac events. Cardiac MRI should be performed early in the course of the disease (<2 weeks after onset of symptoms). Steady-state free-precession T2-weighted MRI with late gadolinium enhancement is the mainstay of the cardiac MRI protocol. Further sequences can be used to analyze the different pathophysiologic subjacent mechanisms of the disease, such as microvascular obstruction or intramyocardial hemorrhage. Finally, cardiac MRI may provide several prognostic biomarkers that help in follow-up of these patients. Online supplemental material is available for this article. ©RSNA, 2020.


Assuntos
Meios de Contraste , Infarto do Miocárdio , Dor no Peito/diagnóstico por imagem , Dor no Peito/etiologia , Gadolínio , Humanos , Imageamento por Ressonância Magnética
10.
Nat Commun ; 10(1): 2030, 2019 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-31048689

RESUMO

Acquired resistance to MEK1/2 inhibitors (MEKi) arises through amplification of BRAFV600E or KRASG13D to reinstate ERK1/2 signalling. Here we show that BRAFV600E amplification and MEKi resistance are reversible following drug withdrawal. Cells with BRAFV600E amplification are addicted to MEKi to maintain a precise level of ERK1/2 signalling that is optimal for cell proliferation and survival, and tumour growth in vivo. Robust ERK1/2 activation following MEKi withdrawal drives a p57KIP2-dependent G1 cell cycle arrest and senescence or expression of NOXA and cell death, selecting against those cells with amplified BRAFV600E. p57KIP2 expression is required for loss of BRAFV600E amplification and reversal of MEKi resistance. Thus, BRAFV600E amplification confers a selective disadvantage during drug withdrawal, validating intermittent dosing to forestall resistance. In contrast, resistance driven by KRASG13D amplification is not reversible; rather ERK1/2 hyperactivation drives ZEB1-dependent epithelial-to-mesenchymal transition and chemoresistance, arguing strongly against the use of drug holidays in cases of KRASG13D amplification.


Assuntos
Antineoplásicos/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Apoptose/genética , Benzimidazóis/farmacologia , Benzimidazóis/uso terapêutico , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Transição Epitelial-Mesenquimal/genética , Feminino , Amplificação de Genes/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , MAP Quinase Quinase 1/antagonistas & inibidores , MAP Quinase Quinase 2/antagonistas & inibidores , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/genética , Masculino , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Neoplasias/genética , Inibidores de Proteínas Quinases/uso terapêutico , Suspensão de Tratamento , Homeobox 1 de Ligação a E-box em Dedo de Zinco/metabolismo
12.
Int J Neonatal Screen ; 5(3): 32, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33072991

RESUMO

Identifying newborns at risk for cystic fibrosis (CF) by newborn screening (NBS) using dried blood spot (DBS) specimens provides an opportunity for presymptomatic detection. All NBS strategies for CF begin with measuring immunoreactive trypsinogen (IRT). Pancreatitis-associated protein (PAP) has been suggested as second-tier testing. The main objective of this study was to evaluate the analytical performance of an IRT/PAP/IRT strategy versus the current IRT/IRT strategy over a two-year pilot study including 68,502 newborns. The design of the study, carried out in a prospective and parallel manner, allowed us to compare four different CF-NBS protocols after performing a post hoc analysis. The best PAP cutoff point and the potential sources of PAP false positive results in our non-CF newborn population were also studied. 14 CF newborns were detected, resulting in an overall CF prevalence of 1/4, 893 newborns. The IRT/IRT algorithm detected all CF cases, but the IRT/PAP/IRT algorithm failed to detect one case of CF. The IRT/PAP/IRT with an IRT-dependent safety net protocol was a good alternative to improve sensitivity to 100%. The IRT × PAP/IRT strategy clearly performed better, with a sensitivity of 100% and a positive predictive value (PPV) of 39%. Our calculated optimal cutoffs were 2.31 µg/L for PAP and 167.4 µg2/L2 for IRT × PAP. PAP levels were higher in females and newborns with low birth weight. PAP false positive results were found mainly in newborns with conditions such as prematurity, sepsis, and hypoxic-ischemic encephalopathy.

13.
Nefrologia ; 37 Suppl 1: 1-191, 2017 Nov.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-29248052

RESUMO

Vascular access for haemodialysis is key in renal patients both due to its associated morbidity and mortality and due to its impact on quality of life. The process, from the creation and maintenance of vascular access to the treatment of its complications, represents a challenge when it comes to decision-making, due to the complexity of the existing disease and the diversity of the specialities involved. With a view to finding a common approach, the Spanish Multidisciplinary Group on Vascular Access (GEMAV), which includes experts from the five scientific societies involved (nephrology [S.E.N.], vascular surgery [SEACV], vascular and interventional radiology [SERAM-SERVEI], infectious diseases [SEIMC] and nephrology nursing [SEDEN]), along with the methodological support of the Cochrane Center, has updated the Guidelines on Vascular Access for Haemodialysis, published in 2005. These guidelines maintain a similar structure, in that they review the evidence without compromising the educational aspects. However, on one hand, they provide an update to methodology development following the guidelines of the GRADE system in order to translate this systematic review of evidence into recommendations that facilitate decision-making in routine clinical practice, and, on the other hand, the guidelines establish quality indicators which make it possible to monitor the quality of healthcare.


Assuntos
Derivação Arteriovenosa Cirúrgica/normas , Diálise Renal/métodos , Dispositivos de Acesso Vascular/normas , Aneurisma/etiologia , Aneurisma/cirurgia , Angioplastia/métodos , Antibioticoprofilaxia/normas , Derivação Arteriovenosa Cirúrgica/efeitos adversos , Derivação Arteriovenosa Cirúrgica/instrumentação , Cateterismo Periférico/efeitos adversos , Cateterismo Periférico/métodos , Cateterismo Periférico/normas , Tomada de Decisão Clínica , Constrição Patológica , Falha de Equipamento , Medicina Baseada em Evidências , Humanos , Controle de Infecções , Agulhas , Exame Físico , Reologia , Espanha , Trombose/etiologia , Trombose/prevenção & controle , Trombose/terapia , Dispositivos de Acesso Vascular/efeitos adversos
14.
Nefrología (Madr.) ; 37(supl.1): 1-193, nov. 2017. graf, tab, ilus
Artigo em Espanhol | IBECS | ID: ibc-169903

RESUMO

El acceso vascular para hemodiálisis es esencial para el enfermo renal tanto por su morbimortalidad asociada como por su repercusión en la calidad de vida. El proceso que va desde la creación y mantenimiento del acceso vascular hasta el tratamiento de sus complicaciones constituye un reto para la toma de decisiones debido a la complejidad de la patología existente y a la diversidad de especialidades involucradas. Con el fin de conseguir un abordaje consensuado, el Grupo Español Multidisciplinar del Acceso Vascular (GEMAV), que incluye expertos de las cinco sociedades científicas implicadas (nefrología [S.E.N.], cirugía vascular [SEACV], radiología vascular e intervencionista [SERAM-SERVEI], enfermedades infecciosas [SEIMC] y enfermería nefrológica [SEDEN]), con el soporte metodológico del Centro Cochrane Iberoamericano, ha realizado una actualización de la Guía del Acceso Vascular para Hemodiálisis publicada en 2005. Esta guía mantiene una estructura similar, revisando la evidencia sin renunciar a la vertiente docente, pero se aportan como novedades, por un lado, la metodología en su elaboración, siguiendo las directrices del sistema GRADE con el objetivo de traducir esta revisión sistemática de la evidencia en recomendaciones que faciliten la toma de decisiones en la práctica clínica habitual y, por otro, el establecimiento de indicadores de calidad que permitan monitorizar la calidad asistencial (AU)


Vascular access for haemodialysis is key in renal patients both due to its associated morbidity and mortality and due to its impact on quality of life. The process, from the creation and maintenance of vascular access to the treatment of its complications, represents a challenge when it comes to decision-making, due to the complexity of the existing disease and the diversity of the specialities involved. With a view to finding a common approach, the Spanish Multidisciplinary Group on Vascular Access (GEMAV), which includes experts from the five scientific societies involved (nephrology [S.E.N.], vascular surgery [SEACV], vascular and interventional radiology [SERAM-SERVEI], infectious diseases [SEIMC] and nephrology nursing [SEDEN]), along with the methodological support of the Cochrane Center, has updated the Guidelines on Vascular Access for Haemodialysis, published in 2005. These guidelines maintain a similar structure, in that they review the evidence without compromising the educational aspects. However, on one hand, they provide an update to methodology development following the guidelines of the GRADE system in order to translate this systematic review of evidence into recommendations that facilitate decision-making in routine clinical practice, and, on the other hand, the guidelines establish quality indicators which make it possible to monitor the quality of healthcare (AU)


Assuntos
Humanos , Dispositivos de Acesso Vascular , Diálise Renal/métodos , Diálise Renal/tendências , Fístula Arteriovenosa/epidemiologia , Cateterismo Venoso Central/métodos , Qualidade de Vida , Diálise Renal/instrumentação , Fístula Arteriovenosa/prevenção & controle , Ablação por Cateter/métodos , Indicadores de Qualidade em Assistência à Saúde , Angioplastia/métodos
17.
Mol Cell Biol ; 35(5): 831-46, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25535334

RESUMO

Sustained Akt activation induces cardiac hypertrophy (LVH), which may lead to heart failure. This study tested the hypothesis that Akt activation contributes to mitochondrial dysfunction in pathological LVH. Akt activation induced LVH and progressive repression of mitochondrial fatty acid oxidation (FAO) pathways. Preventing LVH by inhibiting mTOR failed to prevent the decline in mitochondrial function, but glucose utilization was maintained. Akt activation represses expression of mitochondrial regulatory, FAO, and oxidative phosphorylation genes in vivo that correlate with the duration of Akt activation in part by reducing FOXO-mediated transcriptional activation of mitochondrion-targeted nuclear genes in concert with reduced signaling via peroxisome proliferator-activated receptor α (PPARα)/PGC-1α and other transcriptional regulators. In cultured myocytes, Akt activation disrupted mitochondrial bioenergetics, which could be partially reversed by maintaining nuclear FOXO but not by increasing PGC-1α. Thus, although short-term Akt activation may be cardioprotective during ischemia by reducing mitochondrial metabolism and increasing glycolysis, long-term Akt activation in the adult heart contributes to pathological LVH in part by reducing mitochondrial oxidative capacity.


Assuntos
Cardiomegalia/metabolismo , Núcleo Celular/metabolismo , Mitocôndrias/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Ácidos Graxos/metabolismo , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Glicólise , Coração/fisiologia , Hemodinâmica , Hipertrofia , Masculino , Camundongos , Células Musculares/citologia , Oxigênio/metabolismo , PPAR alfa/metabolismo , Proteômica , Transdução de Sinais , Transcrição Gênica , Transgenes
18.
J Clin Microbiol ; 52(8): 3053-6, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24850345

RESUMO

Amplification of hepatitis C virus (HCV) RNA from blood detected occult HCV infections in 30.9% of 210 HCV-seronegative dialysis patients with abnormal liver enzyme levels that had evaded standard HCV testing practices. Isolated HCV core-specific antibody detection identified three additional anti-HCV screening-negative patients lacking HCV RNA amplification in blood who were considered potentially infectious. Together, these findings may affect management of the dialysis setting.


Assuntos
Anticorpos Anti-Hepatite C/sangue , Hepatite C/diagnóstico , Fragmentos de Peptídeos/imunologia , RNA Viral/sangue , Diálise Renal/efeitos adversos , Proteínas do Core Viral/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Enzimas/sangue , Feminino , Hepatite C/virologia , Humanos , Testes de Função Hepática , Masculino , Pessoa de Meia-Idade
19.
Amino Acids ; 44(2): 361-71, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22722543

RESUMO

Maillard reaction contributes to the chemical modification and cross-linking of proteins. This process plays a significant role in the aging process and determination of animal longevity. Oxidative conditions promote the Maillard reaction. Mitochondria are the primary site of oxidants due to the reactive molecular species production. Mitochondrial proteome cysteine residues are targets of oxidative attack due to their specific chemistry and localization. Their chemical, non-enzymatic modification leads to dysfunctional proteins, which entail cellular senescence and organismal aging. Previous studies have consistently shown that caloric and methionine restrictions, nutritional interventions that increase longevity, decrease the rate of mitochondrial oxidant production and the physiological steady-state levels of markers of oxidative damage to macromolecules. In this scenario, we have detected S-(carboxymethyl)-cysteine (CMC) as a new irreversible chemical modification in mitochondrial proteins. CMC content in mitochondrial proteins significantly correlated with that of the lysine-derived analog N (ε)-(carboxymethyl)-lysine. The concentration of CMC is, however, one order of magnitude lower compared with CML likely due in part to the lower content of cysteine with respect to lysine of the mitochondrial proteome. CMC concentrations decreases in liver mitochondrial proteins of rats subjected to 8.5 and 25 % caloric restriction, as well as in 40 and 80 % methionine restriction. This is associated with a concomitant and significant increase in the protein content of sulfhydryl groups. Data presented here evidence that CMC, a marker of Cys-AGE formation, could be candidate as a biomarker of mitochondrial damage during aging.


Assuntos
Carbocisteína/metabolismo , Fígado/metabolismo , Metionina/metabolismo , Proteínas Mitocondriais/metabolismo , Animais , Restrição Calórica , Carbocisteína/química , Fígado/química , Masculino , Metionina/análise , Mitocôndrias/metabolismo , Proteínas Mitocondriais/química , Estrutura Molecular , Estresse Oxidativo , Ratos , Ratos Wistar
20.
Cancer Cell ; 22(4): 547-60, 2012 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-23079663

RESUMO

Molecular signatures have identified several subsets of diffuse large B cell lymphoma (DLBCL) and rational targets within the B cell receptor (BCR) signaling axis. The OxPhos-DLBCL subset, which harbors the signature of genes involved in mitochondrial metabolism, is insensitive to inhibition of BCR survival signaling but is functionally undefined. We show that, compared with BCR-DLBCLs, OxPhos-DLBCLs display enhanced mitochondrial energy transduction, greater incorporation of nutrient-derived carbons into the tricarboxylic acid cycle, and increased glutathione levels. Moreover, perturbation of the fatty acid oxidation program and glutathione synthesis proved selectively toxic to this tumor subset. Our analysis provides evidence for distinct metabolic fingerprints and associated survival mechanisms in DLBCL and may have therapeutic implications.


Assuntos
Linfoma Difuso de Grandes Células B/metabolismo , Sobrevivência Celular , Ciclo do Ácido Cítrico , Ácidos Graxos/metabolismo , Humanos , Linfoma Difuso de Grandes Células B/patologia , Linfoma Difuso de Grandes Células B/terapia , Mitocôndrias/metabolismo , Oxirredução , Fosforilação Oxidativa , Proteoma , Receptores de Antígenos de Linfócitos B/fisiologia
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