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1.
Cell ; 146(6): 969-79, 2011 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-21906795

RESUMO

Acetylation of histone and nonhistone proteins is an important posttranslational modification affecting many cellular processes. Here, we report that NuA4 acetylation of Sip2, a regulatory ß subunit of the Snf1 complex (yeast AMP-activated protein kinase), decreases as cells age. Sip2 acetylation, controlled by antagonizing NuA4 acetyltransferase and Rpd3 deacetylase, enhances interaction with Snf1, the catalytic subunit of Snf1 complex. Sip2-Snf1 interaction inhibits Snf1 activity, thus decreasing phosphorylation of a downstream target, Sch9 (homolog of Akt/S6K), and ultimately leading to slower growth but extended replicative life span. Sip2 acetylation mimetics are more resistant to oxidative stress. We further demonstrate that the anti-aging effect of Sip2 acetylation is independent of extrinsic nutrient availability and TORC1 activity. We propose a protein acetylation-phosphorylation cascade that regulates Sch9 activity, controls intrinsic aging, and extends replicative life span in yeast.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/citologia , Saccharomyces cerevisiae/fisiologia , Transativadores/metabolismo , Acetilação , Restrição Calórica , Divisão Celular , Histona Acetiltransferases/metabolismo , Histona Desacetilases/metabolismo , Proteínas Quinases/metabolismo , Saccharomyces cerevisiae/enzimologia , Fatores de Transcrição/metabolismo
2.
BMC Bioinformatics ; 21(1): 68, 2020 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-32093643

RESUMO

BACKGROUND: Genome-wide association studies (GWAS) provide a powerful means to identify associations between genetic variants and phenotypes. However, GWAS techniques for detecting epistasis, the interactions between genetic variants associated with phenotypes, are still limited. We believe that developing an efficient and effective GWAS method to detect epistasis will be a key for discovering sophisticated pathogenesis, which is especially important for complex diseases such as Alzheimer's disease (AD). RESULTS: In this regard, this study presents GenEpi, a computational package to uncover epistasis associated with phenotypes by the proposed machine learning approach. GenEpi identifies both within-gene and cross-gene epistasis through a two-stage modeling workflow. In both stages, GenEpi adopts two-element combinatorial encoding when producing features and constructs the prediction models by L1-regularized regression with stability selection. The simulated data showed that GenEpi outperforms other widely-used methods on detecting the ground-truth epistasis. As real data is concerned, this study uses AD as an example to reveal the capability of GenEpi in finding disease-related variants and variant interactions that show both biological meanings and predictive power. CONCLUSIONS: The results on simulation data and AD demonstrated that GenEpi has the ability to detect the epistasis associated with phenotypes effectively and efficiently. The released package can be generalized to largely facilitate the studies of many complex diseases in the near future.


Assuntos
Epistasia Genética , Aprendizado de Máquina , Software , Estudo de Associação Genômica Ampla , Humanos , Fenótipo
3.
Arterioscler Thromb Vasc Biol ; 38(6): 1321-1332, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29724816

RESUMO

OBJECTIVE: Infantile hemangiomas (IHs) are the most common benign vascular neoplasms of infancy, characterized by a rapid growth phase followed by a spontaneous involution, or triggered by propranolol treatment by poorly understood mechanisms. LIN28/let-7 axis plays a central role in the regulation of stem cell self-renewal and tumorigenesis. However, the role of LIN28B/let-7 signaling in IH pathogenesis has not yet been elucidated. APPROACH AND RESULTS: LIN28B is highly expressed in proliferative IH and is less expressed in involuted and in propranolol-treated IH samples as measured by immunofluorescence staining and quantitative RT-PCR. Small RNA sequencing analysis of IH samples revealed a decrease in microRNAs that target LIN28B, including let-7, and an increase in microRNAs in the mir-498(46) cistron. Overexpression of LIN28B in HEK293 cells induced the expression of miR-516b in the mir-498(46) cistron. Propranolol treatment of induced pluripotent stem cells, which express mir-498(46) endogenously, reduced the expression of both LIN28B and mir-498(46) and increased the expression of let-7. Furthermore, propranolol treatment reduced the proliferation of induced pluripotent stem cells and induced epithelial-mesenchymal transition. CONCLUSIONS: This work uncovers the role of the LIN28B/let-7 switch in IH pathogenesis and provides a novel mechanism by which propranolol induces IH involution. Furthermore, it provides therapeutic implications for cancers in which the LIN28/let-7 pathway is imbalanced.


Assuntos
Antineoplásicos/farmacologia , Hemangioma/tratamento farmacológico , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , MicroRNAs/metabolismo , Células-Tronco Neoplásicas/efeitos dos fármacos , Propranolol/farmacologia , Proteínas de Ligação a RNA/metabolismo , Transdução de Sinais/efeitos dos fármacos , Estudos de Casos e Controles , Proliferação de Células/efeitos dos fármacos , Senescência Celular/efeitos dos fármacos , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica , Células HEK293 , Hemangioma/genética , Hemangioma/metabolismo , Hemangioma/patologia , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Pluripotentes Induzidas/patologia , MicroRNAs/genética , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Proteínas de Ligação a RNA/genética
4.
PLoS Genet ; 12(9): e1006262, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27588417

RESUMO

To maintain a particular cell fate, a unique set of genes should be expressed while another set is repressed. One way to repress gene expression is through Polycomb group (PcG) proteins that compact chromatin into a silent configuration. In addition to cell fate maintenance, PcG proteins also maintain normal cell physiology, for example cell cycle. In the absence of PcG, ectopic activation of the PcG-repressed genes leads to developmental defects and malignant tumors. Little is known about the molecular nature of ectopic gene expression; especially what differentiates expression of a given gene in the orthotopic tissue (orthotopic expression) and the ectopic expression of the same gene due to PcG mutations. Here we present that ectopic gene expression in PcG mutant cells specifically requires dBRWD3, a negative regulator of HIRA/Yemanuclein (YEM)-mediated histone variant H3.3 deposition. dBRWD3 mutations suppress both the ectopic gene expression and aberrant tissue overgrowth in PcG mutants through a YEM-dependent mechanism. Our findings identified dBRWD3 as a critical regulator that is uniquely required for ectopic gene expression and aberrant tissue overgrowth caused by PcG mutations.


Assuntos
Ciclo Celular/genética , Diferenciação Celular/genética , Proteínas de Drosophila/genética , Proteínas do Grupo Polycomb/genética , Fatores de Transcrição/genética , Animais , Proteínas de Ciclo Celular/biossíntese , Proteínas de Ciclo Celular/genética , Cromatina/genética , Proteínas de Ligação a DNA/biossíntese , Proteínas de Ligação a DNA/genética , Proteínas de Drosophila/biossíntese , Drosophila melanogaster/genética , Drosophila melanogaster/crescimento & desenvolvimento , Olho/crescimento & desenvolvimento , Olho/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Chaperonas de Histonas/biossíntese , Chaperonas de Histonas/genética , Histonas/genética , Discos Imaginais/crescimento & desenvolvimento , Discos Imaginais/metabolismo , Mutação , Proteínas Nucleares/biossíntese , Proteínas Nucleares/genética , Proteínas do Grupo Polycomb/biossíntese , Fatores de Transcrição/biossíntese
5.
Int J Mol Sci ; 20(5)2019 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-30866433

RESUMO

Trichostatin A (TSA), an antifungal antibiotic derived from Streptomyces, inhibits mammalian histone deacetylases, and especially, selectively inhibits class I and II histone deacetylase (HDAC) families of enzymes. TSA reportedly elicits an antiproliferative response in multifarious tumors. This study investigated the antitumor effects of TSA alone and in combination with paclitaxel when applied to two high-grade urothelial carcinoma (UC) cell lines (BFTC-905 and BFTC-909). Fluorescence-activated cell sorting, flow cytometry, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium assay were used to assess TSA's cytotoxicity and effects on apoptosis induction. TSA induced synergistic cytotoxicity, when combined with paclitaxel (combination index < 1), resulted in concomitant suppression of paclitaxel-induced activation of phospho-extracellular signal-regulated kinase (ERK) 1/2. A xenograft nude mouse model confirmed that TSA enhances the antitumor effects of paclitaxel. These findings demonstrate that the administration of TSA in combination with paclitaxel elicits a synergistic cytotoxic response. The results of this study indicate that the chemoresistance of UC could be circumvented by combining HDAC inhibitors to target the ERK pathway.


Assuntos
Carcinoma de Células de Transição/tratamento farmacológico , Inibidores de Histona Desacetilases/administração & dosagem , Ácidos Hidroxâmicos/administração & dosagem , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Paclitaxel/administração & dosagem , Neoplasias da Bexiga Urinária/tratamento farmacológico , Animais , Carcinoma de Células de Transição/metabolismo , Carcinoma de Células de Transição/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Sinergismo Farmacológico , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Inibidores de Histona Desacetilases/farmacologia , Humanos , Ácidos Hidroxâmicos/farmacologia , Camundongos , Paclitaxel/farmacologia , Resultado do Tratamento , Neoplasias da Bexiga Urinária/metabolismo , Neoplasias da Bexiga Urinária/patologia , Ensaios Antitumorais Modelo de Xenoenxerto
6.
PLoS Genet ; 11(11): e1005642, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26540204

RESUMO

During development, certain Drosophila sensory neurons undergo dendrite pruning that selectively eliminates their dendrites but leaves the axons intact. How these neurons regulate pruning activity in the dendrites remains unknown. Here, we identify a coiled-coil protein Spindle-F (Spn-F) that is required for dendrite pruning in Drosophila sensory neurons. Spn-F acts downstream of IKK-related kinase Ik2 in the same pathway for dendrite pruning. Spn-F exhibits a punctate pattern in larval neurons, whereas these Spn-F puncta become redistributed in pupal neurons, a step that is essential for dendrite pruning. The redistribution of Spn-F from puncta in pupal neurons requires the phosphorylation of Spn-F by Ik2 kinase to decrease Spn-F self-association, and depends on the function of microtubule motor dynein complex. Spn-F is a key component to link Ik2 kinase to dynein motor complex, and the formation of Ik2/Spn-F/dynein complex is critical for Spn-F redistribution and for dendrite pruning. Our findings reveal a novel regulatory mechanism for dendrite pruning achieved by temporal activation of Ik2 kinase and dynein-mediated redistribution of Ik2/Spn-F complex in neurons.


Assuntos
Dendritos/fisiologia , Proteínas de Drosophila/fisiologia , Quinase I-kappa B/metabolismo , Células Receptoras Sensoriais/citologia , Animais , Citoplasma/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster , Dineínas/metabolismo , Fosforilação
7.
EMBO Rep ; 16(4): 528-38, 2015 04.
Artigo em Inglês | MEDLINE | ID: mdl-25666827

RESUMO

Many causal mutations of intellectual disability have been found in genes involved in epigenetic regulations. Replication-independent deposition of the histone H3.3 variant by the HIRA complex is a prominent nucleosome replacement mechanism affecting gene transcription, especially in postmitotic neurons. However, how HIRA-mediated H3.3 deposition is regulated in these cells remains unclear. Here, we report that dBRWD3, the Drosophila ortholog of the intellectual disability gene BRWD3, regulates gene expression through H3.3, HIRA, and its associated chaperone Yemanuclein (YEM), the fly ortholog of mammalian Ubinuclein1. In dBRWD3 mutants, increased H3.3 levels disrupt gene expression, dendritic morphogenesis, and sensory organ differentiation. Inactivation of yem or H3.3 remarkably suppresses the global transcriptome changes and various developmental defects caused by dBRWD3 mutations. Our work thus establishes a previously unknown negative regulation of H3.3 and advances our understanding of BRWD3-dependent intellectual disability.


Assuntos
Proteínas de Ciclo Celular/genética , Proteínas de Ligação a DNA/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Regulação da Expressão Gênica no Desenvolvimento , Chaperonas de Histonas/genética , Histonas/genética , Proteínas Nucleares/genética , Fatores de Transcrição/genética , Animais , Proteínas de Ciclo Celular/metabolismo , Cromatina/química , Cromatina/metabolismo , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/metabolismo , Proteínas de Drosophila/antagonistas & inibidores , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/crescimento & desenvolvimento , Drosophila melanogaster/metabolismo , Chaperonas de Histonas/metabolismo , Histonas/antagonistas & inibidores , Histonas/metabolismo , Humanos , Deficiência Intelectual/genética , Deficiência Intelectual/metabolismo , Deficiência Intelectual/patologia , Morfogênese/genética , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Homologia de Sequência de Aminoácidos , Transdução de Sinais , Fatores de Transcrição/metabolismo
8.
PLoS Genet ; 10(11): e1004760, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25393278

RESUMO

During development, neural competence is conferred and maintained by integrating spatial and temporal regulations. The Drosophila sensory bristles that detect mechanical and chemical stimulations are arranged in stereotypical positions. The anterior wing margin (AWM) is arrayed with neuron-innervated sensory bristles, while posterior wing margin (PWM) bristles are non-innervated. We found that the COP9 signalosome (CSN) suppresses the neural competence of non-innervated bristles at the PWM. In CSN mutants, PWM bristles are transformed into neuron-innervated, which is attributed to sustained expression of the neural-determining factor Senseless (Sens). The CSN suppresses Sens through repression of the ecdysone signaling target gene broad (br) that encodes the BR-Z1 transcription factor to activate sens expression. Strikingly, CSN suppression of BR-Z1 is initiated at the prepupa-to-pupa transition, leading to Sens downregulation, and termination of the neural competence of PWM bristles. The role of ecdysone signaling to repress br after the prepupa-to-pupa transition is distinct from its conventional role in activation, and requires CSN deneddylating activity and multiple cullins, the major substrates of deneddylation. Several CSN subunits physically associate with ecdysone receptors to represses br at the transcriptional level. We propose a model in which nuclear hormone receptors cooperate with the deneddylation machinery to temporally shutdown downstream target gene expression, conferring a spatial restriction on neural competence at the PWM.


Assuntos
Proteínas de Drosophila/genética , Complexos Multiproteicos/genética , Proteínas Nucleares/genética , Peptídeo Hidrolases/genética , Fatores de Transcrição/genética , Asas de Animais/crescimento & desenvolvimento , Animais , Complexo do Signalossomo COP9 , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/crescimento & desenvolvimento , Ecdisona/genética , Ecdisona/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Complexos Multiproteicos/metabolismo , Mutação , Neurônios/metabolismo , Proteínas Nucleares/metabolismo , Peptídeo Hidrolases/metabolismo , Fatores de Transcrição/metabolismo
9.
Pediatr Dermatol ; 34(4): 386-391, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28548465

RESUMO

BACKGROUND/OBJECTIVES: Infantile hemangiomas (IHs) are vascular tumors with the potential for significant morbidity. There is a lack of validated objective tools to assess IH severity and response to treatment. Diffuse optical spectroscopy (DOS), a noninvasive, nonionizing imaging modality, can measure total hemoglobin concentration and hemoglobin oxygen saturation in tissue to assess IH vascularity and response to treatment. Our objective was to evaluate the utility of a wireless, handheld DOS system to assess IH characteristics at selected points during their clinical course. METHODS: Thirteen subjects (initial age 5.8 ± 2.0 mos) with 15 IHs were enrolled. IHs were classified as proliferative, plateau phase, or involuting. Nine patients with 11 IHs were untreated; four patients with 4 IHs were treated with timolol or propranolol. Each IH was evaluated by placing the DOS system directly on the lesion as well a normal contralateral skin site. IH vascularity and oxygenation were scored using a newly defined normalized hypoxia fraction (NHF) coefficient. Measurements were recorded at various intervals from the initial visit to 1 to 2 years of age. RESULTS: For the nine untreated IHs, the NHF was highest at 6 months of age, during proliferation. Differences in NHFs between the proliferation and the plateau (p = 0.02) and involuting (p < 0.001) stages were statistically significant. In treated patients, the NHF normalized to 60% after 2 months. One treated IH came within 5% of the NHF for normal skin after 12 months. CONCLUSIONS: DOS can be used to assess the vascularity and tissue oxygenation of IHs and monitor their progression and response to treatment.


Assuntos
Hemangioma/diagnóstico por imagem , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Antagonistas Adrenérgicos beta/uso terapêutico , Criança , Pré-Escolar , Feminino , Hemangioma/tratamento farmacológico , Humanos , Lactente , Estudos Longitudinais , Projetos Piloto , Tecnologia sem Fio
10.
BMC Genomics ; 17: 220, 2016 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-26969372

RESUMO

BACKGROUND: Recent advances in sequencing technology have opened a new era in RNA studies. Novel types of RNAs such as long non-coding RNAs (lncRNAs) have been discovered by transcriptomic sequencing and some lncRNAs have been found to play essential roles in biological processes. However, only limited information is available for lncRNAs in Drosophila melanogaster, an important model organism. Therefore, the characterization of lncRNAs and identification of new lncRNAs in D. melanogaster is an important area of research. Moreover, there is an increasing interest in the use of ChIP-seq data (H3K4me3, H3K36me3 and Pol II) to detect signatures of active transcription for reported lncRNAs. RESULTS: We have developed a computational approach to identify new lncRNAs from two tissue-specific RNA-seq datasets using the poly(A)-enriched and the ribo-zero method, respectively. In our results, we identified 462 novel lncRNA transcripts, which we combined with 4137 previously published lncRNA transcripts into a curated dataset. We then utilized 61 RNA-seq and 32 ChIP-seq datasets to improve the annotation of the curated lncRNAs with regards to transcriptional direction, exon regions, classification, expression in the brain, possession of a poly(A) tail, and presence of conventional chromatin signatures. Furthermore, we used 30 time-course RNA-seq datasets and 32 ChIP-seq datasets to investigate whether the lncRNAs reported by RNA-seq have active transcription signatures. The results showed that more than half of the reported lncRNAs did not have chromatin signatures related to active transcription. To clarify this issue, we conducted RT-qPCR experiments and found that ~95.24% of the selected lncRNAs were truly transcribed, regardless of whether they were associated with active chromatin signatures or not. CONCLUSIONS: In this study, we discovered a large number of novel lncRNAs, which suggests that many remain to be identified in D. melanogaster. For the lncRNAs that are known, we improved their characterization by integrating a large number of sequencing datasets (93 sets in total) from multiple sources (lncRNAs, RNA-seq and ChIP-seq). The RT-qPCR experiments demonstrated that RNA-seq is a reliable platform to discover lncRNAs. This set of curated lncRNAs with improved annotations can serve as an important resource for investigating the function of lncRNAs in D. melanogaster.


Assuntos
Drosophila melanogaster/genética , RNA Longo não Codificante/genética , Animais , Cromatina/genética , Imunoprecipitação da Cromatina , Anotação de Sequência Molecular , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de RNA
11.
Stem Cells ; 33(8): 2483-95, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26010009

RESUMO

Adipogenesis is essential for soft tissue reconstruction following trauma or tumor resection. We demonstrate that CD31(-)/34(+)/146(-) cells, a subpopulation of the stromal vascular fraction (SVF) of human adipose tissue, were robustly adipogenic. Insulin growth factor-1 (IGF1) promoted a lineage bias towards CD31(-)/34(+)/146(-) cells at the expense of CD31(-)/34(+)/146(+) cells. IGF1 was microencapsulated in poly(lactic-co-glycolic acid) scaffolds and implanted in the inguinal fat pad of C57Bl6 mice. Control-released IGF1 induced remarkable adipogenesis in vivo by recruiting endogenous cells. In comparison with the CD31(-)/34(+)/146(+) cells, CD31(-)/34(+)/146(-) cells had a weaker Wnt/ß-catenin signal. IGF1 attenuated Wnt/ß-catenin signaling by activating Axin2/PPARγ pathways in SVF cells, suggesting IGF1 promotes CD31(-)/34(+)/146(-) bias through tuning Wnt signal. PPARγ response element (PPRE) in Axin2 promoter was crucial for Axin2 upregulation, suggesting that PPARγ transcriptionally activates Axin2. Together, these findings illustrate an Axin2/PPARγ axis in adipogenesis that is particularly attributable to a lineage bias towards CD31(-)/34(+)/146(-) cells, with implications in adipose regeneration.


Assuntos
Adipócitos/metabolismo , Adipogenia , Antígenos de Diferenciação/metabolismo , Diferenciação Celular , Fator de Crescimento Insulin-Like I/metabolismo , Células-Tronco/metabolismo , Adulto , Animais , Feminino , Humanos , Camundongos , Pessoa de Meia-Idade
12.
RNA ; 19(2): 208-18, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23249746

RESUMO

Here, we show that dBCAS2 (CG4980, human Breast Carcinoma Amplified Sequence 2 ortholog) is essential for the viability of Drosophila melanogaster. We find that ubiquitous or tissue-specific depletion of dBCAS2 leads to larval lethality, wing deformities, impaired splicing, and apoptosis. More importantly, overexpression of hBCAS2 rescues these defects. Furthermore, the C-terminal coiled-coil domain of hBCAS2 binds directly to CDC5L and recruits hPrp19/PLRG1 to form a core complex for splicing in mammalian cells and can partially restore wing damage induced by knocking down dBCAS2 in flies. In summary, Drosophila and human BCAS2 share a similar function in RNA splicing, which affects cell viability.


Assuntos
Apoptose/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Proteínas de Neoplasias/metabolismo , Splicing de RNA/genética , Asas de Animais/anormalidades , Animais , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular , Proteínas de Drosophila/genética , Drosophila melanogaster/anatomia & histologia , Drosophila melanogaster/crescimento & desenvolvimento , Drosophila melanogaster/metabolismo , Técnicas de Silenciamento de Genes , Humanos , Imuno-Histoquímica , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Larva/crescimento & desenvolvimento , Proteínas de Neoplasias/genética , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Especificidade de Órgãos , Fenótipo , Regiões Promotoras Genéticas , Mapeamento de Interação de Proteínas , Estrutura Terciária de Proteína , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Proteínas Recombinantes de Fusão , Asas de Animais/crescimento & desenvolvimento
13.
Pediatr Dermatol ; 32(4): 539-43, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25690955

RESUMO

Infantile hemangiomas (IHs) are the most common benign tumor of infancy, characterized by a natural history of early proliferation in the first months of life to eventual involution during childhood, often with residual fibrofatty tissue. Once involution has been achieved, IHs do not typically recur. We present two cases of exogenous growth hormone therapy resulting in the recurrence of IHs in late childhood, supported by radiological, immunohistochemical, in vitro, and in vivo evidence.


Assuntos
Hemangioma/induzido quimicamente , Hormônio do Crescimento Humano/efeitos adversos , Recidiva Local de Neoplasia/induzido quimicamente , Neoplasias Cutâneas/induzido quimicamente , Biópsia , Criança , Feminino , Hemangioma/patologia , Hemangioma/cirurgia , Hormônio do Crescimento Humano/deficiência , Humanos , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/cirurgia , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/cirurgia
14.
Pediatr Dermatol ; 32(1): 76-84, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25040287

RESUMO

Capillary malformation-arteriovenous malformation syndrome (CM-AVM) is an autosomal dominant disorder caused by RASA1 mutations. The prevalence and phenotypic spectrum are unknown. Evaluation of patients with multiple CMs is challenging because associated AVMs can be life threatening. The objective of this study was to describe the clinical characteristics of children presenting with features of CM-AVM to an academic pediatric dermatology practice. After institutional review board approval was received, a retrospective chart review was performed of patients presenting between 2009 and 2012 with features of CM-AVM. We report nine cases. Presenting symptoms ranged from extensive vascular stains and cardiac failure to CMs noted incidentally during routine skin examination. All demonstrated multiple CMs, two had Parkes Weber syndrome, and two had multiple infantile hemangiomas. Seven patients had family histories of multiple CMs; three had family histories of large, atypical CMs. Six had personal or family histories of AVMs. Genetic evaluation was recommended for all and was pursued by six families; four RASA1 mutations were identified, including one de novo. Consultations with neurology, cardiology, and orthopedics were recommended. Most patients (89%) have not required treatment to date. CM-AVM is an underrecognized condition with a wide clinical spectrum that often presents in childhood. Further evaluation may be indicated in patients with multiple CMs. This study is limited by its small and retrospective nature.


Assuntos
Malformações Arteriovenosas/diagnóstico , Capilares/anormalidades , Mancha Vinho do Porto/diagnóstico , Malformações Arteriovenosas/genética , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Mutação/genética , Mancha Vinho do Porto/genética , Estudos Retrospectivos , Proteína p120 Ativadora de GTPase/genética
15.
Pediatr Transplant ; 18(5): E174-9, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25041331

RESUMO

Intestinal transplantation is a well-accepted treatment for SBS. However, patients with SBS often have decreased abdominal capacity, which makes size-matching of donor organs more difficult, thus decreasing organ availability. Reported approaches for addressing this problem include surgically reducing the graft size, leaving an open abdomen for a prolonged period, and cotransplanting rectus fascia as a non-vascularized allograft. Each approach has significant disadvantages. There has been one previous report of tissue expanders used intra-abdominally and two reports of subcutaneous use to increase intra-abdominal capacity prior to transplantation. We report the first use of bi-planar expander placement for this purpose. In our case, a two-yr-old male child with SBS due to malrotation was treated with tissue expanders 10 months prior to intestinal transplantation, thus allowing transplantation of a larger graft with the ability to close the abdomen safely. There were no complications, and the patient is now doing well and tolerating diet off PN. The use of tissue expanders prior to intestinal transplantation is a promising approach for such patients and avoids the morbidity associated with other approaches. This approach requires a multidisciplinary effort by gastroenterology, transplant surgery, and plastic surgery teams.


Assuntos
Intestinos/transplante , Hipertensão Intra-Abdominal/cirurgia , Síndrome do Intestino Curto/cirurgia , Dispositivos para Expansão de Tecidos , Transplante/instrumentação , Transplante/métodos , Cavidade Abdominal/cirurgia , Pré-Escolar , Humanos , Intestinos/diagnóstico por imagem , Hipertensão Intra-Abdominal/diagnóstico por imagem , Masculino , Complicações Pós-Operatórias , Radiografia , Procedimentos de Cirurgia Plástica , Reoperação , Síndrome do Intestino Curto/diagnóstico por imagem , Resultado do Tratamento
16.
Ann Plast Surg ; 73 Suppl 1: S119-24, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25115372

RESUMO

BACKGROUND: Infantile hemangiomas (IHs) are the most common tumor of infancy, yet there are no Food and Drug Administration-approved therapeutics to date. Recently, the nonselective ß-adrenergic-blocker propranolol has been shown to be a safe and effective means of treating IHs, although its mechanism has yet to be elucidated. We have previously demonstrated that propranolol induces early and incomplete adipogenesis in stem cells derived from hemangiomas. We hypothesize that propranolol promotes dysregulated adipogenesis via the improper regulation of adipogenic genes. METHODS: Hemangioma stem cells (HemSCs) isolated from resected IH specimens were treated with adipogenic medium for 1 or 4 days in either propranolol or vehicle. Cell death was measured by the incorporation of annexin V and propidium iodide by flow cytometry. Adipogenesis was assessed by visualizing lipid droplet formation by Oil Red O staining. Proadipogenic genes C/EBPα, C/EBPß, C/EBPδ, PPARδ, PPARγ, RXRα, and RXRγ were analyzed by quantitative reverse transcription and polymerase chain reaction. RESULTS: Hemangioma stem cells treated with propranolol increased lipid droplet formation compared to vehicle-treated cells indicating increased adipogenesis. Cell death as measured by FACS analysis indicated that the propranolol-treated cells died due to necrosis and not apoptosis. During adipogenesis, transcript levels of PPARδ, PPARγ, C/EBPß, and C/EBPδ were significantly increased (P<0.01) in propranolol-treated cells relative to control cells. In contrast, RXRα and RXRγ levels were significantly decreased (P<0.05), and C/EBPα, a gene required for terminal adipocyte differentiation, was strongly suppressed by propranolol when compared to vehicle-treated cells (P<0.01). CONCLUSIONS: In HemSCs, propranolol accelerated dysregulated adipogenic differentiation characterized by improper adipogenic gene expression. Consistent with accelerated adipogenesis, propranolol significantly increased the expression of the proadipogenic genes, PPARγ, C/EBPß, and C/EBPγ compared to control. However, propranolol treatment also led to improper induction of PPARδ and suppression of C/EBPα, RXRα, and RXRγ. Taken together these data indicate that propranolol promoted dysregulated adipogenesis and inhibited the HemSCs from becoming functional adipocytes, ultimately resulting in cell death. Understanding this mechanism behind propranolol's effectiveness will be a vital factor in producing more effective therapies in the future.


Assuntos
Adipogenia/efeitos dos fármacos , Hemangioma/patologia , Células-Tronco Neoplásicas/patologia , Propranolol/farmacologia , Humanos , Fatores de Tempo , Células Tumorais Cultivadas
17.
Plast Reconstr Surg Glob Open ; 12(5): e5832, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38798935

RESUMO

Background: Infantile hemangiomas (IHs) are benign endothelial cell (EC) tumors that undergo a predictable natural history, with rapid proliferation, stabilization, and involution. However, mechanisms regulating these transitions are not well understood. We have observed loss of vascular endothelial cadherin (VECAD) in involuting/involuted IHs. VECAD plays a critical role in angiogenesis, cell cycle progression, and EC survival. We hypothesize that loss of VECAD is associated with apoptosis occurring during IH involution. Methods: Resected IH samples were clinically categorized as proliferating (n = 4), stable (n = 4), or involuting/involuted (n = 5). Neonatal dermal tissues were used as controls (n = 5). Immunohistochemistry was conducted on sectioned specimens using antibodies against EC markers VECAD and CD31. Apoptosis was assessed with terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling assay. Results: CD31 signal intensity in proliferating, stable, and involuting/involuted IH ECs was unchanged relative to each other and to control ECs. VECAD signal significantly and progressively diminished as IHs progressed from proliferation to involution. Involuting/involuted IHs had significantly reduced VECAD expression compared with control ECs (P < 0.0001), proliferating IHs (P < 0.0001), and stable IHs (P < 0.001). As expected, the number of terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling-positive ECs was significantly higher in involuting/involuted IHs (P < 0.05) relative to control ECs and proliferating IHs. Conclusions: Loss of VECAD expression in IH endothelium corresponded to IH involution and increased apoptosis. It is unclear whether loss of VECAD is causative of IH involution; further studies are needed to elucidate the role of VECAD function in EC survival.

18.
J Plast Reconstr Aesthet Surg ; 90: 224-226, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38387419

RESUMO

BACKGROUND: Recent trials have demonstrated clinical benefits to a combined orthoplastic approach for complex reconstructive surgery of the hand, upper and lower extremity. PURPOSE: We sought to assess recent trends in exposure to orthoplastic-type procedures among plastic surgery residents training in the United States. METHODS: Independent plastic surgery residents' case logs were extracted from the Accreditation Council for Graduate Medical Education (2011-2022). Select reconstructive procedure were taken as proxies for orthoplastic-type cases and analyzed by descriptive statistical analysis. RESULTS: The average number of orthoplastic-type cases completed per resident per year increased from 168.2 to 189.2 (12.5% increase) between 2011-2022. The greatest increase was in exposure to peripheral nerve injury repair of the hand and upper extremity (22.6 to 39.1, 73% increase). As a proportion of total procedures during the study period, orthoplastic-type procedures remained relatively unchanged (range 9.5-10.4%). CONCLUSIONS: Our findings suggest that plastic surgery residents may be increasingly well-prepared to contribute to orthoplastic care during and following their training. The steady proportion of cases that orthoplastic-type procedures represented over the study period suggests the increase in relevant orthoplastic case volume may be incidental and secondary to an overall rise among all procedures. Given evidence of the benefits of an orthoplastic approach, we recommend consideration of explicit benchmarks for orthoplastic training among plastic surgery residents.


Assuntos
Cirurgia Geral , Internato e Residência , Procedimentos de Cirurgia Plástica , Cirurgia Plástica , Humanos , Estados Unidos , Cirurgia Plástica/educação , Educação de Pós-Graduação em Medicina/métodos , Acreditação , Competência Clínica , Cirurgia Geral/educação
20.
Pediatr Dermatol ; 30(6): e180-90, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23025620

RESUMO

We present a case of a large congenital hemangioma (CH) on the neck causing cardiac failure and thrombocytopenia in a female neonate. A trial of medical therapy with corticosteroids and propranolol was attempted, but the patient ultimately underwent definitive treatment with embolization and surgical resection with a positive outcome. A review of the English language literature revealed 16 previously reported cases of CHs complicated by congestive heart failure. This series supports known demographic features of CHs, including a lack of gender discrepancy and a predilection to affect the head and neck. These CHs are rarely diagnosed in utero; most patients present with a mass at birth. Cardiac failure is identified prenatally or in the first days of life. A mild to moderate thrombocytopenia and coagulopathy, which is likely transient and distinct from classic Kasabach-Merritt phenomenon, accompanies many of these cases. There is a 30% associated mortality rate. Both medical and interventional treatment modalities have been reported. Steroids are the most commonly used medication, but without any clear benefit. We hypothesize that, based on its possible mechanisms of action,propranolol may be a more effective treatment for CHs requiring treatment. As surgical intervention may be necessary, we recommend a multidisciplinary approach to treating patients with problematic CHs.


Assuntos
Insuficiência Cardíaca/etiologia , Hemangioma/congênito , Hemangioma/complicações , Neoplasias Cutâneas/congênito , Neoplasias Cutâneas/complicações , Cardiomegalia/etiologia , Feminino , Doenças Fetais/patologia , Hemangioma/cirurgia , Humanos , Recém-Nascido , Imageamento por Ressonância Magnética , Neoplasias Cutâneas/cirurgia
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