Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
3.
Endocr Pract ; 28(4): 433-448, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35396078

RESUMO

OBJECTIVE: The objective of this disease state clinical review is to provide clinicians with a summary of the nonsurgical, minimally invasive approaches to managing thyroid nodules/malignancy, including their indications, efficacy, side effects, and outcomes. METHODS: A literature search was conducted using PubMed and appropriate key words. Relevant publications on minimally invasive thyroid techniques were used to create this clinical review. RESULTS: Minimally invasive thyroid techniques are effective and safe when performed by experienced centers. To date, percutaneous ethanol injection therapy is recommended for recurrent benign thyroid cysts. Both ultrasound-guided laser and radiofrequency ablation can be safely used for symptomatic solid nodules, both toxic and nontoxic. Microwave ablation and high-intensity focused ultrasound are newer approaches that need further clinical evaluation. Despite limited data, encouraging results suggest that minimally invasive techniques can also be used in small-size primary and locally recurrent thyroid cancer. CONCLUSION: Surgery and radioiodine treatment remain the conventional and established treatments for nodular goiters. However, the new image-guided minimally invasive approaches appear safe and effective alternatives when used appropriately and by trained professionals to treat symptomatic or enlarging thyroid masses.


Assuntos
Ablação por Cateter , Neoplasias da Glândula Tireoide , Nódulo da Glândula Tireoide , Ablação por Cateter/métodos , Humanos , Radioisótopos do Iodo/uso terapêutico , Recidiva Local de Neoplasia/cirurgia , Neoplasias da Glândula Tireoide/cirurgia , Nódulo da Glândula Tireoide/patologia , Nódulo da Glândula Tireoide/cirurgia , Resultado do Tratamento
4.
Obesity (Silver Spring) ; 28(4): O1-O58, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32202076

RESUMO

OBJECTIVE: The development of these updated clinical practice guidelines (CPGs) was commissioned by the American Association of Clinical Endocrinologists (AACE), The Obesity Society (TOS), American Society for Metabolic and Bariatric Surgery (ASMBS), Obesity Medicine Association (OMA), and American Society of Anesthesiologists (ASA) Boards of Directors in adherence with the AACE 2017 protocol for standardized production of CPGs, algorithms, and checklists. METHODS: Each recommendation was evaluated and updated based on new evidence from 2013 to the present and subjective factors provided by experts. RESULTS: New or updated topics in this CPG include: contextualization in an adiposity-based chronic disease complications-centric model, nuance-based and algorithm/checklist-assisted clinical decision-making about procedure selection, novel bariatric procedures, enhanced recovery after bariatric surgery protocols, and logistical concerns (including cost factors) in the current health care arena. There are 85 numbered recommendations that have updated supporting evidence, of which 61 are revised and 12 are new. Noting that there can be multiple recommendation statements within a single numbered recommendation, there are 31 (13%) Grade A, 42 (17%) Grade B, 72 (29%) Grade C, and 101 (41%) Grade D recommendations. There are 858 citations, of which 81 (9.4%) are evidence level (EL) 1 (highest), 562 (65.5%) are EL 2, 72 (8.4%) are EL 3, and 143 (16.7%) are EL 4 (lowest). CONCLUSIONS: Bariatric procedures remain a safe and effective intervention for higher-risk patients with obesity. Clinical decision-making should be evidence based within the context of a chronic disease. A team approach to perioperative care is mandatory, with special attention to nutritional and metabolic issues.


Assuntos
Cirurgia Bariátrica/normas , Bariatria/normas , Obesidade/terapia , Cirurgia Bariátrica/métodos , Bariatria/métodos , Feminino , Humanos , Masculino
5.
Surg Obes Relat Dis ; 16(2): 175-247, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31917200

RESUMO

OBJECTIVE: The development of these updated clinical practice guidelines (CPG) was commissioned by the American Association of Clinical Endocrinologists, The Obesity Society, the American Society of Metabolic and Bariatric Surgery, the Obesity Medicine Association, and the American Society of Anesthesiologists boards of directors in adherence to the American Association of Clinical Endocrinologists 2017 protocol for standardized production of CPG, algorithms, and checklists. METHODS: Each recommendation was evaluated and updated based on new evidence from 2013 to the present and subjective factors provided by experts. RESULTS: New or updated topics in this CPG include contextualization in an adiposity-based, chronic disease complications-centric model, nuance-based, and algorithm/checklist-assisted clinical decision-making about procedure selection, novel bariatric procedures, enhanced recovery after bariatric surgery protocols, and logistical concerns (including cost factors) in the current healthcare arena. There are 85 numbered recommendations that have updated supporting evidence, of which 61 are revised and 12 are new. Noting that there can be multiple recommendation statements within a single numbered recommendation, there are 31 (13%) Grade A, 42 (17%) Grade B, 72 (29%) Grade C, and 101 (41%) Grade D recommendations. There are 858 citations, of which 81 (9.4%) are evidence level (EL) 1 (highest), 562 (65.5%) are EL 2, 72 (8.4%) are EL 3, and 143 (16.7%) are EL 4 (lowest). CONCLUSIONS: Bariatric procedures remain a safe and effective intervention for higher-risk patients with obesity. Clinical decision-making should be evidence-based within the context of a chronic disease. A team approach to perioperative care is mandatory with special attention to nutritional and metabolic issues.


Assuntos
Cirurgia Bariátrica , Bariatria , Anestesiologistas , Endocrinologistas , Humanos , Obesidade/cirurgia , Estados Unidos
6.
Endocr Pract ; 25(12): 1346-1359, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31682518

RESUMO

Objective: The development of these updated clinical practice guidelines (CPGs) was commissioned by the American Association of Clinical Endocrinologists (AACE), The Obesity Society, American Society of Metabolic and Bariatric Surgery, Obesity Medicine Association, and American Society of Anesthesiologists Boards of Directors in adherence with the AACE 2017 protocol for standardized production of CPGs, algorithms, and checklists. Methods: Each recommendation was evaluated and updated based on new evidence from 2013 to the present and subjective factors provided by experts. Results: New or updated topics in this CPG include: contextualization in an adiposity-based chronic disease complications-centric model, nuance-based and algorithm/checklist-assisted clinical decision-making about procedure selection, novel bariatric procedures, enhanced recovery after bariatric surgery protocols, and logistical concerns (including cost factors) in the current health-care arena. There are 85 numbered recommendations that have updated supporting evidence, of which 61 are revised and 12 are new. Noting that there can be multiple recommendation statements within a single numbered recommendation, there are 31 (13%) Grade A, 42 (17%) Grade B, 72 (29%) Grade C, and 101 (41%) Grade D recommendations. There are 858 citations, of which 81 (9.4%) are evidence level (EL) 1 (highest), 562 (65.5%) are EL 2, 72 (8.4%) are EL 3, and 143 (16.7%) are EL 4 (lowest). Conclusion: Bariatric procedures remain a safe and effective intervention for higher-risk patients with obesity. Clinical decision-making should be evidence based within the context of a chronic disease. A team approach to perioperative care is mandatory, with special attention to nutritional and metabolic issues. A1C = hemoglobin A1c; AACE = American Association of Clinical Endocrinologists; ABCD = adiposity-based chronic disease; ACE = American College of Endocrinology; ADA = American Diabetes Association; AHI = Apnea-Hypopnea Index; ASA = American Society of Anesthesiologists; ASMBS = American Society of Metabolic and Bariatric Surgery; BMI = body mass index; BPD = biliopancreatic diversion; BPD/DS = biliopancreatic diversion with duodenal switch; CI = confidence interval; CPAP = continuous positive airway pressure; CPG = clinical practice guideline; CRP = C-reactive protein; CT = computed tomography; CVD = cardiovascular disease; DBCD = dysglycemia-based chronic disease; DS = duodenal switch; DVT = deep venous thrombosis; DXA = dual-energy X-ray absorptiometry; EFA = essential fatty acid; EL = evidence level; EN = enteral nutrition; ERABS = enhanced recovery after bariatric surgery; FDA = U.S. Food and Drug Administration; G4G = Guidelines for Guidelines; GERD = gastroesophageal reflux disease; GI = gastrointestinal; HCP = health-care professional(s); HTN = hypertension; ICU = intensive care unit; IGB = intragastric balloon(s); IV = intravenous; LAGB = laparoscopic adjustable gastric band; LAGBP = laparoscopic adjustable gastric banded plication; LGP = laparoscopic greater curvature (gastric) plication; LRYGB = laparoscopic Roux-en-Y gastric bypass; LSG = laparoscopic sleeve gastrectomy; MetS = metabolic syndrome; NAFLD = nonalcoholic fatty liver disease; NASH = nonalcoholic steatohepatitis; NSAID = nonsteroidal anti-inflammatory drug; OA = osteoarthritis; OAGB = one-anastomosis gastric bypass; OMA = Obesity Medicine Association; OR = odds ratio; ORC = obesity-related complication(s); OSA = obstructive sleep apnea; PE = pulmonary embolism; PN = parenteral nutrition; PRM = pulmonary recruitment maneuver; RCT = randomized controlled trial; RD = registered dietician; RDA = recommended daily allowance; RYGB = Roux-en-Y gastric bypass; SG = sleeve gastrectomy; SIBO = small intestinal bacterial overgrowth; TOS = The Obesity Society; TSH = thyroid-stimulating hormone; T1D = type 1 diabetes; T2D = type 2 diabetes; VTE = venous thromboembolism; WE = Wernicke encephalopathy; WHO = World Health Organization.


Assuntos
Cirurgia Bariátrica , Diabetes Mellitus Tipo 2 , Balão Gástrico , Derivação Gástrica , Laparoscopia , Obesidade , Anestesiologistas , Endocrinologistas , Humanos , Estados Unidos
7.
J Alzheimers Dis ; 68(1): 357-365, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30775993

RESUMO

Genome-wide association studies identified a single nucleotide polymorphism (SNP) in the MSRB3 gene encoding Methionine Sulfoxide Reductase-B3 (MsrB3) to be associated with the risk for low hippocampal volume and late onset Alzheimer's disease (AD). Subsequently, we identified AD-associated abnormal patterns of neuronal and vascular MsrB3 expression in postmortem hippocampi. The present study investigated the relationship between the MSRB3 SNP rs61921502, G (minor/risk allele) and MRI measures of brain injury including total brain volume, hippocampal volume, and white matter hyperintensities using linear regression models; the presence of brain infarcts using logistic regression models; and the incidence of stroke, dementia, and AD using Cox proportional hazards models in 2,038 Framingham Heart Study Offspring participants with MRI administered close to examination cycle 7 (1998-2001). Participants with neurological conditions that impede evaluation of vascular pathology by MRI, i.e., brain tumors, multiple sclerosis, and major head trauma, were excluded from the study. When adjusted for age and age squared at MRI exam, sex, and presence of Apolipoproteinɛ4 allele (APOE4), individuals with MSRB3 rs61921502 minor allele had increased odds for brain infarcts on MRI compared to those with no minor allele. However, in stratified analyses, MSRB3 rs61921502 minor allele was significantly associated with increased odds for MRI brain infarcts only in the absence of APOE4.


Assuntos
Alelos , Infarto Encefálico/genética , Demência/genética , Predisposição Genética para Doença , Hipocampo/diagnóstico por imagem , Metionina Sulfóxido Redutases/genética , Polimorfismo de Nucleotídeo Único , Idoso , Infarto Encefálico/diagnóstico por imagem , Infarto Encefálico/epidemiologia , Demência/diagnóstico por imagem , Demência/epidemiologia , Feminino , Humanos , Incidência , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade
8.
J Alzheimers Dis ; 63(4): 1433-1443, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29843236

RESUMO

The pathophysiology of Alzheimer's disease (AD) includes signaling defects mediated by the transforming growth factor ß-bone morphogenetic protein-growth and differentiation factor (TGFß-BMP-GDF) family of proteins. In animal models of AD, administration of BMP9/GDF2 improves memory and reduces amyloidosis. The best characterized type I receptor of BMP9 is ALK1. We characterized ALK1 expression in the hippocampus using immunohistochemistry. In the rat, ALK1 immunoreactivity was found in CA pyramidal neurons, most frequently and robustly in the CA2 and CA3 fields. In addition, there were sporadic ALK1-immunoreactive cells in the stratum oriens, mainly in CA1. The ALK1 expression pattern in human hippocampus was similar to that of rat. Pyramidal neurons within the CA2, CA3, and CA4 were strongly ALK1-immunoreactive in hippocampi of cognitively intact subjects with no neurofibrillary tangles. ALK1 signal was found in the axons of alveus and fimbria, and in the neuropil across CA fields. Relatively strongest ALK1 neuropil signal was observed in CA1 where pyramidal neurons were occasionally ALK1-immunoractive. As in the rat, horizontally oriented neurons in the stratum oriens of CA1 were both ALK1- and GAD67-immunoreactive. Analysis of ALK1 immunoreactivity across stages of AD pathology revealed that disease progression was characterized by overall reduction of the ALK1 signal in CA3 in advanced, but not early, stages of AD. These data suggest that the CA3 pyramidal neurons may remain responsive to the ALK1 ligands, e.g., BMP9, during initial stages of AD and that ALK1 may constitute a therapeutic target in early and moderate AD.


Assuntos
Receptores de Activinas Tipo II/metabolismo , Receptores de Ativinas/metabolismo , Doença de Alzheimer/patologia , Região CA3 Hipocampal/metabolismo , Progressão da Doença , Idoso , Doença de Alzheimer/metabolismo , Animais , Feminino , Glutamato Descarboxilase/metabolismo , Fator 2 de Diferenciação de Crescimento , Fatores de Diferenciação de Crescimento/metabolismo , Humanos , Masculino , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Ratos , Ratos Wistar
9.
Biochemistry ; 55(24): 3447-60, 2016 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-27254467

RESUMO

Protein structure, ligand binding, and catalytic turnover contributes to the governance of catalytic events occurring at spatially distinct domains in multifunctional enzymes. Coordination of these catalytic events partially rests on the ability of spatially discrete active sites to communicate with other allosteric and active sites on the same polypeptide chain (intramolecular) or on different polypeptide chains (intermolecular) within the holoenzyme. Often, communication results in long-range effects on substrate binding or product release. For example, pyruvate binding to the carboxyl transferase (CT) domain of pyruvate carboxylase (PC) increases the rate of product release in the biotin carboxylase (BC) domain. In order to address how CT domain ligand occupancy is "sensed" by other domains, we generated functional, mixed hybrid tetramers using the E218A (inactive BC domain) and T882S (low pyruvate binding, low activity) mutant forms of PC. The apparent Ka pyruvate for the pyruvate-stimulated release of Pi catalyzed by the T882S:E218A[1:1] hybrid tetramer was comparable to the wild-type enzyme and nearly 10-fold lower than that for the T882S homotetramer. In addition, the ratio of the rates of oxaloacetate formation to Pi release for the WT:T882S[1:1] and E218A:T882S[1:1] hybrid tetramer-catalyzed reactions was 0.5 and 0.6, respectively, while the T882S homotetramer exhibited a near 1:1 coupling of the two domains, suggesting that the mechanisms coordinating catalytic events is more complicated that we initially assumed. The results presented here are consistent with an intermolecular communication mechanism, where pyruvate binding to the CT domain is "sensed" by domains on a different polypeptide chain within the tetramer.


Assuntos
Proteínas de Bactérias/química , Biotina/metabolismo , Carbono-Nitrogênio Ligases/química , Carboxil e Carbamoil Transferases/química , Piruvato Carboxilase/química , Ácido Pirúvico/química , Sequência de Aminoácidos , Proteínas de Bactérias/metabolismo , Sítios de Ligação , Carbono-Nitrogênio Ligases/metabolismo , Carboxil e Carbamoil Transferases/metabolismo , Domínio Catalítico , Cristalografia por Raios X , Cinética , Modelos Moleculares , Mutagênese Sítio-Dirigida , Mutação/genética , Conformação Proteica , Piruvato Carboxilase/genética , Piruvato Carboxilase/metabolismo , Ácido Pirúvico/metabolismo , Homologia de Sequência de Aminoácidos
10.
J Neuropathol Exp Neurol ; 75(8): 779-790, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27346750

RESUMO

Genome-wide association studies have established BIN1 (Bridging Integrator 1) as the most significant late-onset Alzheimer disease (AD) susceptibility locus after APOE We analyzed BIN1 protein expression using automated immunohistochemistry on the hippocampal CA1 region in 19 patients with either no, mild, or moderate-to-marked AD pathology, who had been assessed by Clinical Dementia Rating and CERAD scores. We also examined the amygdala, prefrontal, temporal, and occipital regions in a subset of these patients. In non-demented controls without AD pathology, BIN1 protein was expressed in white matter, glia, particularly oligodendrocytes, and in the neuropil in which the BIN1 signal decorated axons. With increasing severity of AD, BIN1 in the CA1 region showed: 1) sustained expression in glial cells, 2) decreased areas of neuropil expression, and 3) increased cytoplasmic neuronal expression that did not correlate with neurofibrillary tangle load. In patients with AD, both the prefrontal cortex and CA1 showed a decrease in BIN1-immunoreactive (BIN1-ir) neuropil areas and increases in numbers of BIN1-ir neurons. The numbers of CA1 BIN1-ir pyramidal neurons correlated with hippocampal CERAD neuritic plaque scores; BIN1 neuropil signal was absent in neuritic plaques. Our data provide novel insight into the relationship between BIN1 protein expression and the progression of AD-associated pathology and its diagnostic hallmarks.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/biossíntese , Doença de Alzheimer/metabolismo , Córtex Cerebral/metabolismo , Progressão da Doença , Proteínas Nucleares/biossíntese , Proteínas Supressoras de Tumor/biossíntese , Proteínas Adaptadoras de Transdução de Sinal/genética , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Córtex Cerebral/patologia , Feminino , Expressão Gênica , Humanos , Espaço Intracelular/genética , Espaço Intracelular/metabolismo , Masculino , Pessoa de Meia-Idade , Proteínas Nucleares/genética , Proteínas Supressoras de Tumor/genética
11.
Ann Neurol ; 67(1): 136-40, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20186852

RESUMO

We investigated a large German family (n = 37) with male members who had contractures, rigid spine syndrome, and hypertrophic cardiomyopathy. Muscle weakness or atrophy was not prominent in affected individuals. Muscle biopsy disclosed a myopathic pattern with cytoplasmic bodies. We used microsatellite markers and found linkage to a locus at Xq26-28, a region harboring the FHL1 gene. We sequenced FHL1 and identified a new missense mutation within the third LIM domain that replaces a highly conserved cysteine by an arginine (c.625T>C; p.C209R). Our finding expands the phenotypic spectrum of the recently identified FHL1-associated myopathies and widens the differential diagnosis of Emery-Dreifuss-like syndromes.


Assuntos
Cardiomiopatia Hipertrófica/genética , Contratura/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteínas Musculares/genética , Mutação de Sentido Incorreto , Adolescente , Adulto , Cardiomiopatia Hipertrófica/patologia , Criança , Contratura/patologia , Família , Feminino , Ligação Genética , Alemanha , Humanos , Proteínas com Domínio LIM , Masculino , Repetições de Microssatélites , Pessoa de Meia-Idade , Linhagem , Fenótipo , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Fatores Sexuais , Adulto Jovem
12.
Exp Cell Res ; 316(5): 728-36, 2010 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-20025869

RESUMO

We could recently demonstrate an important role of receptor interacting protein 4 (RIP4) in the regulation of keratinocyte differentiation. Now, we analyzed a potential role of the RIP4 homolog RIP2 in keratinocytes. Specifically, we demonstrate here that rip2 expression is induced by scratch-wounding and after the induction of differentiation in these cells. Furthermore, serum growth factors and cytokines can induce rip2, with TNF-alpha-dependent induction being dependent on p38 MAPK. In addition, we demonstrate that scratch-induced upregulation of rip2 expression is completely blocked by the steroid dexamethasone. Since we also show that RIP2 is an important player in the regulation of keratinocyte proliferation, these data suggest that inhibition of rip2 upregulation after wounding might contribute to the reduced and delayed wound re-epithelialization phenotype seen in glucocorticoid-treated patients.


Assuntos
Proliferação de Células , Queratinócitos/fisiologia , Proteína Serina-Treonina Quinase 2 de Interação com Receptor/metabolismo , Cicatrização/fisiologia , Diferenciação Celular/fisiologia , Células Cultivadas , Citocinas/metabolismo , Dexametasona/metabolismo , Glucocorticoides/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Queratinócitos/citologia , Proteína Serina-Treonina Quinase 2 de Interação com Receptor/genética , Fator de Necrose Tumoral alfa/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
13.
Eur J Cell Biol ; 87(3): 163-72, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17961803

RESUMO

RIP2 is an important regulator of myoblast proliferation and differentiation. We have previously demonstrated that in the myoblast cell line C2C12 and in primary myoblasts, downregulation of rip2 gene expression is a prerequisite for differentiation. To further study the role of rip genes in myogenesis, we compared expression patterns of rip1-4 in two myoblast cell lines, C2C12 and C2F3, after the induction of differentiation. These two cell lines are derived from the same clonal origin, but differ with respect to their differentiation behaviour: specifically, the differentiation process is slower and more incomplete in C2F3 cells. When analyzing cells up to 4 days after the induction of differentiation, we found no downregulation of rip2 gene expression in C2F3 cells, which might be linked to the low differentiation potential of these cells. In addition, in contrast to C2C12 cells, the rip3 gene was not expressed in C2F3 cells. To further study the role of rip genes in the regulation of myoblast growth and differentiation, we analyzed expression patterns of rip1-4 in rhabdomyosarcoma cell lines. We found that in these cells, rip2 expression was not downregulated after the induction of differentiation. Furthermore, in contrast to normal myoblasts, they did not express the rip3 and rip4 genes. Thus, we focused on the functional role of RIP2 in rhabdomyosarcoma cells. Inhibition of rip2 gene expression in C2C12 and in rhabdomyosarcoma cells using specific siRNAs led to decreased proliferation and promoted the differentiation process of these cells. These data indicate that differential expression of rip genes can be associated with abnormal growth and differentiation behaviour of skeletal myoblasts.


Assuntos
Mioblastos Esqueléticos/metabolismo , Proteína Serina-Treonina Quinases de Interação com Receptores/genética , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Rabdomiossarcoma/metabolismo , Animais , Diferenciação Celular , Linhagem Celular , Proliferação de Células , Regulação da Expressão Gênica , Camundongos , Desenvolvimento Muscular , Mioblastos Esqueléticos/citologia , RNA Interferente Pequeno/metabolismo , Proteína Serina-Treonina Quinase 2 de Interação com Receptor , Rabdomiossarcoma/patologia , Transfecção
14.
J Invest Dermatol ; 127(3): 538-44, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17039240

RESUMO

Receptor-interacting proteins (RIPs) are important regulators of cell proliferation and differentiation. As RIP4 is a crucial modulator of epidermal differentiation, we analyzed the expression of different rip genes in healing skin wounds. Rip4 expression was strongly downregulated in keratinocytes of the hyperproliferative epithelium at the wound edge early after injury and only returned to basal levels after completion of wound repair. Rip3 expression was strongly induced as early as 1 day after wounding. In contrast, rip and rip2 expression remained unaltered. To determine the factors that regulate rip4 gene expression in keratinocytes, human HaCaT keratinocytes were used as a model system. We found that scratch wounding as well as treatment with whole serum, phorbol esters, the growth/differentiation factors epidermal growth factor, transforming growth factor-beta, and activin A, or the proinflammatory cytokines tumor necrosis factor-alpha and IL-1beta strongly suppressed rip4 expression in these cells. In contrast, the steroid dexamethasone and all-trans retinoic acid slightly stimulated rip4 expression. Suppression of rip4 expression in keratinocytes using small interfering RNA technology reduced the activation of NF-kappaB, and enhanced the expression of epidermal differentiation markers in these cells. These data suggest important and unique functions of different RIP proteins in keratinocytes of normal and wounded skin.


Assuntos
Regulação da Expressão Gênica , Queratinócitos/citologia , NF-kappa B/metabolismo , Proteínas Quinases/fisiologia , Proteínas Serina-Treonina Quinases/fisiologia , Pele/metabolismo , Cicatrização , Animais , Diferenciação Celular , Proliferação de Células , Feminino , Humanos , Queratinócitos/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Microscopia de Fluorescência , Pele/patologia
15.
J Biol Chem ; 281(41): 30471-8, 2006 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-16912050

RESUMO

The deposition of beta-amyloid in the brain is a pathological hallmark of Alzheimer disease (AD). Normally, the accumulation of beta-amyloid is prevented in part by the activities of several degradative enzymes, including the endothelin-converting enzymes, neprilysin, insulin-degrading enzyme, and plasmin. Recent reports indicate that another metalloprotease, angiotensin-converting enzyme (ACE), can degrade beta-amyloid in vitro and in cellular overexpression experiments. In addition, ACE gene variants are linked to AD risk in several populations. Angiotensin-converting enzyme, neprilysin and endothelin-converting enzyme function as vasopeptidases and are the targets of drugs designed to treat cardiovascular disorders, and ACE inhibitors are commonly prescribed. We investigated the potential physiological role of ACE in regulating endogenous brain beta-amyloid levels for two reasons: first, to determine whether beta-amyloid degradation might be the mechanism by which ACE is associated with AD, and second, to determine whether ACE inhibitor drugs might block beta-amyloid degradation in the brain and potentially increase the risk for AD. We analyzed beta-amyloid accumulation in brains from ACE-deficient mice and in mice treated with ACE inhibitors and found that ACE deficiency did not alter steady-state beta-amyloid concentration. In contrast, beta-amyloid levels are significantly elevated in endothelin-converting enzyme and neprilysin knock-out mice, and inhibitors of these enzymes cause a rapid increase in beta-amyloid concentration in the brain. The results of these studies do not support a physiological role for ACE in the degradation of beta-amyloid in the brain but confirm roles for endothelin-converting enzyme and neprilysin and indicate that reductions in these enzymes result in additive increases in brain amyloid beta-peptide levels.


Assuntos
Peptídeos beta-Amiloides/química , Ácido Aspártico Endopeptidases/metabolismo , Regulação Enzimológica da Expressão Gênica , Metaloendopeptidases/metabolismo , Neprilisina/fisiologia , Peptidil Dipeptidase A/metabolismo , Administração Oral , Peptídeos beta-Amiloides/metabolismo , Animais , Encéfalo/metabolismo , Enzimas Conversoras de Endotelina , Inibidores Enzimáticos/farmacologia , Humanos , Camundongos , Camundongos Knockout
16.
Proc Natl Acad Sci U S A ; 103(32): 11993-8, 2006 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-16880393

RESUMO

PU.1 is essential for early stages of mouse T cell development but antagonizes it if expressed constitutively. Two separable mechanisms are involved: attenuation and diversion. Dysregulated PU.1 expression inhibits pro-T cell survival, proliferation, and passage through beta-selection by blocking essential T cell transcription factors, signaling molecules, and Rag gene expression, which expression of a rearranged T cell antigen receptor transgene cannot rescue. However, Bcl2 transgenic cells are protected from this attenuation and may even undergo beta-selection, as shown by PU.1 transduction of defined subsets of Bcl2 transgenic fetal thymocytes with differentiation in OP9-DL1 and OP9 control cultures. The outcome of PU.1 expression in these cells depends on Notch/Delta signaling. PU.1 can efficiently divert thymocytes toward a myeloid-like state with multigene regulatory changes, but Notch/Delta signaling vetoes diversion. Gene expression analysis distinguishes sets of critical T lineage regulatory genes with different combinatorial responses to PU.1 and Notch/Delta signals, suggesting particular importance for inhibition of E proteins, Myb, and/or Gfi1 (growth factor independence 1) in diversion. However, Notch signaling only protects against diversion of cells that have undergone T lineage specification after Thy-1 and CD25 up-regulation. The results imply that in T cell precursors, Notch/Delta signaling normally acts to modulate and channel PU.1 transcriptional activities during the stages from T lineage specification until commitment.


Assuntos
Regulação da Expressão Gênica , Proteínas Proto-Oncogênicas/fisiologia , Receptor Notch1/fisiologia , Transdução de Sinais , Linfócitos T/metabolismo , Transativadores/fisiologia , Animais , Linhagem da Célula , Sobrevivência Celular , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Modelos Biológicos , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Receptor Notch1/metabolismo , Receptores de Interleucina-2/biossíntese , Transativadores/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA