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1.
JCO Glob Oncol ; 8: e2100371, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35696624

RESUMO

PURPOSE: COVID-19 caused a disruption in cancer management around the world, resulting in an estimated excess burden secondary to screening disruption and excess lag time for treatment initiation. METHODS: We gathered information from primary reimbursement data sets of the public health system of São Paulo, Brazil, from April 2020 to November 2021, and compared these data with those of the pre-COVID-19 period. We used an interrupted time series model to estimate the effect of the COVID-19 pandemic on the rate of key procedures of breast and cervical cancer health care chain. RESULTS: We estimated that 1,149,727, 2,693, and 713,616 pap smears, conizations, and mammograms, respectively, were missed or delayed during the COVID-19 pandemic, compared with those in the years immediately before the COVID-19 stay-at-home restrictions. Specifically, we observed an acute decrease of procedures after the COVID-19 stay-at-home restrictions, with a trend to recovery in the long term. Regarding the systemic treatment analysis, we observed a 25% reduction in the rate of initiation of adjuvant systemic treatment for early breast cancer (stage I/II). However, we did not find a clear effect on the other settings of systemic treatment for breast cancer. We estimated an excess of 156 patients starting palliative care for cervical cancer after the COVID-19 stay-at-home restrictions. CONCLUSION: The COVID-19 pandemic significantly reduced the performance rate of pap smears, conizations, and mammograms. The initiation of adjuvant treatment for early-stage breast cancer was most susceptible to COVID-19's health system disruption. Furthermore, the downward trend of treatment of advanced cervical cancer was interrupted. Therefore, public health policies are urgently needed to decrease the incidence of advanced cervical and breast cancers caused by delayed diagnosis and treatment initiation.The COVID-19 control policies resulted in reduction of cancer patients' delivery of care. This study evaluated the pandemic's influence in key procedures of breast and cervical cancer chain of care in São Paulo, Brazil. We observed a substantial reduction in the number of mammograms, pap smears, and conizations performed since the onset of the COVID-19 pandemic. In addition, stage I and II breast cancer adjuvant treatment presented a reduced realization rate, whereas palliative treatment delivered for advanced cervical cancer increased. Our results support the need for public health policies focused on mitigating the long-term effects of COVID-19 in cancer-related mortality.


Assuntos
Neoplasias da Mama , COVID-19 , Detecção Precoce de Câncer , Neoplasias do Colo do Útero , Brasil/epidemiologia , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/terapia , COVID-19/epidemiologia , Detecção Precoce de Câncer/estatística & dados numéricos , Feminino , Humanos , Análise de Séries Temporais Interrompida , Pandemias , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/terapia
2.
J Glob Oncol ; 5: 1-5, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31393754

RESUMO

PURPOSE: Approximately 4% to 10% of patients diagnosed with Chagas-induced megaesophagus disease develop esophageal carcinoma. However, the natural history and clinical pattern of this entity are not well described. METHODS: Herein, we retrospectively analyzed 593 patients with esophageal carcinoma treated at a single Brazilian institution. We identified 32 patients with Chagas disease, of whom 11 had megaesophagus. The epidemiologic profile and oncological treatment outcomes were evaluated. RESULTS: Although baseline characteristics were similar among the three groups, patients with Chagas megaesophagus-associated carcinoma (CMAC) presented with a lower rate of smoking. This factor reinforced the concept that achalasia is the predominant risk factor for cancer development. The CMAC group had a higher rate of tumor in situ (two of 11 patients) compared with the other groups. These patients were treated with endoscopic resection, and no recurrence was detected. Eight of 11 patients with CMAC were diagnosed with locally advanced disease. Patients with locally advanced CMAC presented with a median progression-free survival of 7.8 months and a median overall survival of 9.1 months. CONCLUSION: If CMAC is not promptly detected, it has a dismal prognosis, indicating that a high index of suspicion of esophageal carcinoma is required for patients with Chagasic megaesophagus. Additional studies are needed to improve the surveillance and treatment approaches for this neglected disease.


Assuntos
Doença de Chagas/complicações , Neoplasias Esofágicas/virologia , Estudos de Casos e Controles , Neoplasias Esofágicas/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Resultado do Tratamento
3.
Gastroenterology ; 153(3): 871, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28864274

RESUMO

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief and Deputy Editor-in-Chief following an investigation into the data that were presented in several figures within the article. A number of images used in this article are believed to be duplicated images. The authors stated that they inadvertently inserted images of the wrong blots in several of the figures, resulting in the duplications; however, they did not address all of the concerns raised. Because the editors were no longer confident in the conclusions of the article based on these incorrect data, a decision was made to retract the paper. All authors have been notified of this decision. The University of Campinas (UNICAMP) in São Paulo, Brazil was contacted regarding these concerns, but to date the journal has received no response.

4.
J Endocrinol ; 226(3): R29-43, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26112046

RESUMO

Cancer and its morbidities, such as cancer cachexia, constitute a major public health problem. Although cancer cachexia has afflicted humanity for centuries, its underlying multifactorial and complex physiopathology has hindered the understanding of its mechanism. During the last few decades we have witnessed a dramatic increase in the understanding of cancer cachexia pathophysiology. Anorexia and muscle and adipose tissue wasting are the main features of cancer cachexia. These apparently independent symptoms have humoral factors secreted by the tumor as a common cause. Importantly, the hypothalamus has emerged as an organ that senses the peripheral signals emanating from the tumoral environment, and not only elicits anorexia but also contributes to the development of muscle and adipose tissue loss. Herein, we review the roles of factors secreted by the tumor and its effects on the hypothalamus, muscle and adipose tissue, as well as highlighting the key targets that are being exploited for cancer cachexia treatment.


Assuntos
Tecido Adiposo/metabolismo , Caquexia/metabolismo , Músculo Esquelético/metabolismo , Neoplasias/metabolismo , Caquexia/etiologia , Metabolismo Energético/fisiologia , Humanos , Neoplasias/complicações
5.
EMBO Mol Med ; 7(2): 190-210, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25617315

RESUMO

Alzheimer's disease (AD) is associated with peripheral metabolic disorders. Clinical/epidemiological data indicate increased risk of diabetes in AD patients. Here, we show that intracerebroventricular infusion of AD-associated Aß oligomers (AßOs) in mice triggered peripheral glucose intolerance, a phenomenon further verified in two transgenic mouse models of AD. Systemically injected AßOs failed to induce glucose intolerance, suggesting AßOs target brain regions involved in peripheral metabolic control. Accordingly, we show that AßOs affected hypothalamic neurons in culture, inducing eukaryotic translation initiation factor 2α phosphorylation (eIF2α-P). AßOs further induced eIF2α-P and activated pro-inflammatory IKKß/NF-κB signaling in the hypothalamus of mice and macaques. AßOs failed to trigger peripheral glucose intolerance in tumor necrosis factor-α (TNF-α) receptor 1 knockout mice. Pharmacological inhibition of brain inflammation and endoplasmic reticulum stress prevented glucose intolerance in mice, indicating that AßOs act via a central route to affect peripheral glucose homeostasis. While the hypothalamus has been largely ignored in the AD field, our findings indicate that AßOs affect this brain region and reveal novel shared molecular mechanisms between hypothalamic dysfunction in metabolic disorders and AD.


Assuntos
Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Hipotálamo/metabolismo , Oligonucleotídeos/metabolismo , Nervos Periféricos/metabolismo , Doença de Alzheimer/genética , Peptídeos beta-Amiloides/genética , Animais , Feminino , Glucose/metabolismo , Humanos , Macaca , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/genética , NF-kappa B/metabolismo , Neurônios/metabolismo , Oligonucleotídeos/genética , Ratos , Transdução de Sinais , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo
6.
J Urol ; 193(2): 682-9, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25200808

RESUMO

PURPOSE: We characterized the functional consequences of intravesical bacillus Calmette-Guérin on the molecular mechanism of the AKT/mTOR signaling pathway in nonmuscle invasive bladder cancer. To our knowledge this has not been reported previously. MATERIALS AND METHODS: At age 7 weeks female Fischer 344 rats received 1.5 mg/kg MNU intravesically every other week for 6 weeks. They were randomized at 10 per group to MNU (0.2 ml vehicle), bacillus Calmette-Guérin (10(6) cfu Connaught strain), rapamycin (15 µg/ml) and bacillus Calmette-Guérin plus simultaneous rapamycin, each intravesically for 6 weeks. At week 15 the bladders were collected for histopathology, immunohistochemistry and immunoblot to determine p-AKT, Rictor, Raptor, p-4E-BP1, p-p70S6K1, p-AMPK-α, p-mTOR and p-p53. RESULTS: Papillary carcinoma (pTa) and high grade intraepithelial neoplasia (pTis) predominated in the MNU group while normal urothelium, papillary and flat hyperplasia were more common in treated groups. Nonmuscle invasive bladder cancer treated with bacillus Calmette-Guérin showed suppression of p70S6K1 but not 4E-BP1 phosphorylation. This suggests that 4E-BP1 is regulated differently than p70S6K1, escaping the bacillus Calmette-Guérin action that occurs in a mTOR independent manner. The association of bacillus Calmette-Guérin with rapamycin but not rapamycin monotherapy affected p70S6K1 and 4E-BP1 phosphorylation with no features of in situ carcinoma (pTis). CONCLUSIONS: The activation status of p70S6K1 and 4E-BP1 might be used to stratify patients who could benefit from targeting such molecular elements with multitarget/multidrug intravesical therapy. In the future 4E-BP1 might be a worthwhile new target for bacillus Calmette-Guérin refractory nonmuscle invasive bladder cancer.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Adjuvantes Imunológicos/administração & dosagem , Vacina BCG/administração & dosagem , Fosfoproteínas/metabolismo , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Neoplasias da Bexiga Urinária/metabolismo , Adjuvantes Imunológicos/uso terapêutico , Administração Intravesical , Animais , Vacina BCG/uso terapêutico , Proteínas de Ciclo Celular , Feminino , Invasividade Neoplásica , Fosforilação , Ratos , Ratos Endogâmicos F344 , Neoplasias da Bexiga Urinária/tratamento farmacológico , Neoplasias da Bexiga Urinária/patologia
7.
Nat Commun ; 5: 4859, 2014 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-25255053

RESUMO

Sphingosine 1-phosphate receptor 1 (S1PR1) is a G-protein-coupled receptor for sphingosine-1-phosphate (S1P) that has a role in many physiological and pathophysiological processes. Here we show that the S1P/S1PR1 signalling pathway in hypothalamic neurons regulates energy homeostasis in rodents. We demonstrate that S1PR1 protein is highly enriched in hypothalamic POMC neurons of rats. Intracerebroventricular injections of the bioactive lipid, S1P, reduce food consumption and increase rat energy expenditure through persistent activation of STAT3 and the melanocortin system. Similarly, the selective disruption of hypothalamic S1PR1 increases food intake and reduces the respiratory exchange ratio. We further show that STAT3 controls S1PR1 expression in neurons via a positive feedback mechanism. Interestingly, several models of obesity and cancer anorexia display an imbalance of hypothalamic S1P/S1PR1/STAT3 axis, whereas pharmacological intervention ameliorates these phenotypes. Taken together, our data demonstrate that the neuronal S1P/S1PR1/STAT3 signalling axis plays a critical role in the control of energy homeostasis in rats.


Assuntos
Metabolismo Energético , Hipotálamo/metabolismo , Lisofosfolipídeos/metabolismo , Receptores de Lisoesfingolipídeo/metabolismo , Esfingosina/análogos & derivados , Animais , Homeostase , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , Pró-Opiomelanocortina/metabolismo , Ratos , Ratos Wistar , Receptores de Lisoesfingolipídeo/genética , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Esfingosina/metabolismo , Receptores de Esfingosina-1-Fosfato
8.
Mol Cell Endocrinol ; 397(1-2): 15-22, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24952114

RESUMO

The control of energy homeostasis relies on robust neuronal circuits that regulate food intake and energy expenditure. Although the physiology of these circuits is well understood, the molecular and cellular response of this program to chronic diseases is still largely unclear. Hypothalamic inflammation has emerged as a major driver of energy homeostasis dysfunction in both obesity and anorexia. Importantly, this inflammation disrupts the action of metabolic signals promoting anabolism or supporting catabolism. In this review, we address the evidence that favors hypothalamic inflammation as a factor that resets energy homeostasis in pathological states.


Assuntos
Sistema Nervoso Central/fisiologia , Metabolismo Energético , Homeostase , Hipotálamo/patologia , Animais , Anorexia/complicações , Anorexia/metabolismo , Anorexia/patologia , Humanos , Hipotálamo/metabolismo , Inflamação/complicações , Insulina/metabolismo , Leptina/metabolismo , Modelos Biológicos , Obesidade/complicações , Obesidade/metabolismo , Obesidade/patologia , Transdução de Sinais
10.
Cell Metab ; 18(6): 831-43, 2013 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-24315369

RESUMO

Alzheimer's disease (AD) and type 2 diabetes appear to share similar pathogenic mechanisms. dsRNA-dependent protein kinase (PKR) underlies peripheral insulin resistance in metabolic disorders. PKR phosphorylates eukaryotic translation initiation factor 2α (eIF2α-P), and AD brains exhibit elevated phospho-PKR and eIF2α-P levels. Whether and how PKR and eIF2α-P participate in defective brain insulin signaling and cognitive impairment in AD are unknown. We report that ß-amyloid oligomers, AD-associated toxins, activate PKR in a tumor necrosis factor α (TNF-α)-dependent manner, resulting in eIF2α-P, neuronal insulin receptor substrate (IRS-1) inhibition, synapse loss, and memory impairment. Brain phospho-PKR and eIF2α-P were elevated in AD animal models, including monkeys given intracerebroventricular oligomer infusions. Oligomers failed to trigger eIF2α-P and cognitive impairment in PKR(-/-) and TNFR1(-/-) mice. Bolstering insulin signaling rescued phospho-PKR and eIF2α-P. Results reveal pathogenic mechanisms shared by AD and diabetes and establish that proinflammatory signaling mediates oligomer-induced IRS-1 inhibition and PKR-dependent synapse and memory loss.


Assuntos
Peptídeos beta-Amiloides/toxicidade , Encéfalo/efeitos dos fármacos , Proteínas Substratos do Receptor de Insulina/metabolismo , Polímeros/toxicidade , Fator de Necrose Tumoral alfa/metabolismo , eIF-2 Quinase/metabolismo , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/química , Animais , Encéfalo/metabolismo , Modelos Animais de Doenças , Haplorrinos/metabolismo , Hipoglicemiantes/farmacologia , Proteínas Substratos do Receptor de Insulina/antagonistas & inibidores , Transtornos da Memória/metabolismo , Transtornos da Memória/patologia , Camundongos , Camundongos Knockout , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fosforilação/efeitos dos fármacos , Polímeros/química , Receptores Tipo I de Fatores de Necrose Tumoral/deficiência , Receptores Tipo I de Fatores de Necrose Tumoral/genética , Receptores Tipo I de Fatores de Necrose Tumoral/metabolismo , Transdução de Sinais/efeitos dos fármacos , Sinapses/efeitos dos fármacos , Sinapses/metabolismo , Fator de Necrose Tumoral alfa/antagonistas & inibidores , eIF-2 Quinase/deficiência , eIF-2 Quinase/genética
11.
Onkologie ; 36(9): 502-4, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24051927

RESUMO

BACKGROUND: Gastric neuroendocrine tumors (NET) are rare and are classified into 3 types: type 1 and 2 (characterized by hypergastrinemia), and type 3 (characterized by normal gastrin). Surgery is the standard procedure, and systemic treatment is reserved for unresectable disease. Currently, targeted therapies are being evaluated in NET. The activity of everolimus, an mTOR inhibitor, has been shown in pancreatic NET but not reported in type 3 gastric carcinoid tumors. CASE REPORT: Here we report a case of a patient who, after multiple lines of systemic therapy, had a prolonged disease control of nearly 1 year, significant clinical benefit, and minor tumor shrinkage with oral everolimus 10 mg continuously. CONCLUSION: There is no effective treatment for type 3 gastric carcinoid tumors. The frequency of mTOR expression in these tumors is not known, but the case reported here suggests that inhibition of this pathway may play an important role.


Assuntos
Tumores Neuroendócrinos/diagnóstico por imagem , Tumores Neuroendócrinos/tratamento farmacológico , Sirolimo/análogos & derivados , Neoplasias Gástricas/diagnóstico por imagem , Neoplasias Gástricas/tratamento farmacológico , Tomografia Computadorizada por Raios X , Antineoplásicos/uso terapêutico , Everolimo , Humanos , Masculino , Pessoa de Meia-Idade , Sirolimo/uso terapêutico , Resultado do Tratamento
12.
Am J Physiol Endocrinol Metab ; 305(5): E649-59, 2013 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-23880311

RESUMO

Hypothalamic inflammation is associated with insulin and leptin resistance, hyperphagia, and obesity. In this scenario, hypothalamic protein tyrosine phosphatase 1B (PTP1B) has emerged as the key phosphatase induced by inflammation that is responsible for the central insulin and leptin resistance. Here, we demonstrated that acute exercise reduced inflammation and PTP1B protein level/activity in the hypothalamus of obese rodents. Exercise disrupted the interaction between PTP1B with proteins involved in the early steps of insulin (IRß and IRS-1) and leptin (JAK2) signaling, increased the tyrosine phosphorylation of these molecules, and restored the anorexigenic effects of insulin and leptin in obese rats. Interestingly, the anti-inflammatory action and the reduction of PTP1B activity mediated by exercise occurred in an interleukin-6 (IL-6)-dependent manner because exercise failed to reduce inflammation and PTP1B protein level after the disruption of hypothalamic-specific IL-6 action in obese rats. Conversely, intracerebroventricular administration of recombinant IL-6 reproduced the effects of exercise, improving hypothalamic insulin and leptin action by reducing the inflammatory signaling and PTP1B activity in obese rats at rest. Taken together, our study reports that physical exercise restores insulin and leptin signaling, at least in part, by reducing hypothalamic PTP1B protein level through the central anti-inflammatory response.


Assuntos
Hipotálamo/metabolismo , Inflamação/metabolismo , Insulina/metabolismo , Leptina/metabolismo , Obesidade/metabolismo , Condicionamento Físico Animal/fisiologia , Proteína Tirosina Fosfatase não Receptora Tipo 1/metabolismo , Animais , Western Blotting , Corticosterona/urina , Hipotálamo/enzimologia , Imuno-Histoquímica , Inflamação/enzimologia , Insulina/sangue , Interleucina-6/sangue , Interleucina-6/metabolismo , Leptina/sangue , Masculino , Camundongos , Camundongos Obesos , Obesidade/enzimologia , Distribuição Aleatória , Ratos , Ratos Wistar , Transdução de Sinais , Organismos Livres de Patógenos Específicos
13.
Obesity (Silver Spring) ; 21(12): 2452-7, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23519983

RESUMO

OBJECTIVE: The double-stranded RNA-dependent protein kinase (PKR) was recently implicated in regulating molecular integration of nutrient- and pathogen-sensing pathways in obese mice. However, its modulation in human tissues in situations of insulin resistance has not been investigated. The present study was performed to first determine the tissue expression and phosphorylation levels of PKR in the liver, muscle, and adipose tissue in obese humans, and also the modulation of this protein in the adipose tissue of obese patients after bariatric surgery. DESIGN AND METHODS: Eleven obese subjects who were scheduled to undergo Roux-en-Y Gastric Bypass Procedure participated in this study. Nine apparently healthy lean subjects as a control group were also included. RESULTS: Our data show that PKR is activated in liver, muscle, and adipose tissue of obese humans and, after bariatric surgery, there is a clear reduction in PKR activation accompanied by a decrease in protein kinase-like endoplasmic reticulum kinase, c-Jun N-terminal kinase, inhibitor of kappa ß kinase, and insulin receptor substrate-1 serine 312 phosphorylation in subcutaneous adipose tissue from these patients. CONCLUSION: Thus, it is proposed that PKR is an important mediator of obesity-induced insulin resistance and a potential target for the therapy.


Assuntos
Resistência à Insulina , Obesidade/enzimologia , eIF-2 Quinase/metabolismo , Adulto , Antropometria , Glicemia/metabolismo , Índice de Massa Corporal , Estudos de Casos e Controles , Feminino , Derivação Gástrica , Humanos , Insulina/sangue , Proteínas Substratos do Receptor de Insulina/genética , Proteínas Substratos do Receptor de Insulina/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/genética , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Fígado/enzimologia , Masculino , Músculo Esquelético/enzimologia , Obesidade/cirurgia , Fosforilação , Gordura Subcutânea/enzimologia , eIF-2 Quinase/genética
14.
Metabolism ; 62(2): 171-8, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22898253

RESUMO

Hypothalamic 5'-adenosine monophosphate-activated protein kinase (AMPK) senses intracellular metabolic stress, i.e., an increase in the cellular AMP:ATP ratio, and integrates diverse hormonal and nutritional signals to restore energy balance. Recent evidence suggests that different nutrients can modulate AMPK activity in the hypothalamus, thereby controlling weight gain through a leptin-independent mechanism. Understanding the mechanisms by which nutrients control hypothalamic AMPK activity is crucial to the development of effective nutritional interventions for the treatment of food intake-related disorders, such as anorexia and obesity. This article highlights the current evidence for the intricate relationship between nutrients and hypothalamic AMPK activity.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Ingestão de Alimentos/fisiologia , Hipotálamo/metabolismo , Animais , Metabolismo Energético/fisiologia , Homeostase/fisiologia , Humanos , Hipotálamo/enzimologia
15.
Endocrinology ; 153(12): 5760-9, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23024263

RESUMO

Insulin resistance is present in obesity and in type 2 diabetes and is associated with islet cell hyperplasia and hyperinsulinemia, but the driving forces behind this compensatory mechanism are incompletely understood. Previous data have suggested the involvement of an unknown circulating insulin resistance-related ß-cell growth factor. In this context, looking for candidates to be a circulating factor, we realized that hepatocyte growth factor (HGF) is a strong candidate as a link between insulin resistance and increased mass of islets/hyperinsulinemia. Our approach aimed to show a possible cause-effect relationship between increase in circulating HGF levels and compensatory islet hyperplasia/hyperinsulinemia by showing the strength of the association, whether or not is a dose-dependent response, the temporality, consistency, plausibility, and reversibility of the association. In this regard, our data showed: 1) a strong and consistent correlation between HGF and the compensatory mechanism in three animal models of insulin resistance; 2) HGF increases ß-cell mass in a dose-dependent manner; 3) blocking HGF shuts down the compensatory mechanisms; and 4) an increase in HGF levels seems to precede the compensatory response associated with insulin resistance, indicating that these events occur in a sequential mode. Additionally, blockages of HGF receptor (Met) worsen the impaired insulin-induced insulin signaling in liver of diet-induced obesity rats. Overall, our data indicate that HGF is a growth factor playing a key role in islet mass increase and hyperinsulinemia in diet-induced obesity rats and suggest that the HGF-Met axis may have a role on insulin signaling in the liver.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Fator de Crescimento de Hepatócito/metabolismo , Resistência à Insulina , Proteínas Proto-Oncogênicas c-met/metabolismo , Ração Animal , Animais , Dieta , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Fígado/metabolismo , Masculino , Camundongos , Obesidade/metabolismo , Ratos , Ratos Wistar , Transdução de Sinais , Fatores de Tempo
16.
Crit Care ; 16(4): R158, 2012 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-22897821

RESUMO

INTRODUCTION: Hyperglycemia and insulin resistance have been associated with a worse outcome in sepsis. Although tight glycemic control through insulin therapy has been shown to reduce morbidity and mortality rates, the effect of intensive insulin therapy in patients with severe sepsis is controversial because of the increased risk of serious adverse events related to hypoglycemia. Recently, knowledge about diacerhein, an anthraquinone drug with powerful antiinflammatory properties, revealed that this drug improves insulin sensitivity, mediated by the reversal of chronic subclinical inflammation. The aim of the present study was to evaluate whether the antiinflammatory effects of diacerhein after onset of sepsis-induced glycemic alterations is beneficial and whether the survival rate is prolonged in this situation. METHODS: Diffuse sepsis was induced by cecal ligation and puncture surgery (CLP) in male Wistar rats. Blood glucose and inflammatory cytokine levels were assessed 24 hours after CLP. The effect of diacerhein on survival of septic animals was investigated in parallel with insulin signaling and its modulators in liver, muscle, and adipose tissue. RESULTS: Here we demonstrated that diacerhein treatment improves survival during peritoneal-induced sepsis and inhibits sepsis-induced insulin resistance by improving insulin signaling via increased insulin-receptor substrate-1-associated phosphatidylinositol 3-kinase activity and Akt phosphorylation. Diacerhein also decreases the activation of endoplasmic reticulum stress signaling that involves upregulation of proinflammatory pathways, such as the I kappa B kinase and c-Jun NH2-terminal kinase, which blunts insulin-induced insulin signaling in liver, muscle, and adipose tissue. Additionally, our data show that this drug promoted downregulation of proinflammatory signaling cascades that culminate in transcription of immunomodulatory factors such interleukin (IL)-1ß, IL-6, and tumor necrosis factor-α. CONCLUSIONS: This study demonstrated that diacerhein treatment increases survival and attenuates the inflammatory response with a significant effect on insulin sensitivity. On the basis of efficacy and safety profile, diacerhein represents a novel antiinflammatory therapy for management of insulin resistance in sepsis and a potential approach for future clinical trials.


Assuntos
Antraquinonas/uso terapêutico , Anti-Inflamatórios/uso terapêutico , Inflamação/fisiopatologia , Sepse/tratamento farmacológico , Sepse/fisiopatologia , Tecido Adiposo/metabolismo , Animais , Glicemia/metabolismo , Citocinas/sangue , Insulina/metabolismo , Resistência à Insulina , Fígado/metabolismo , Masculino , Músculo Esquelético/metabolismo , Ratos Wistar , Transdução de Sinais
17.
Gastroenterology ; 143(3): 741-753.e4, 2012 09.
Artigo em Inglês | MEDLINE | ID: mdl-22677195

RESUMO

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief and Deputy Editor-in-Chief following an investigation into the data that were presented in several figures within the article. A number of images used in this article are believed to be duplicated images. The authors stated that they inadvertently inserted images of the wrong blots in several of the figures, resulting in the duplications; however, they did not address all of the concerns raised. Because the editors were no longer confident in the conclusions of the article based on these incorrect data, a decision was made to retract the paper. All authors have been notified of this decision. The University of Campinas (UNICAMP) in São Paulo, Brazil was contacted regarding these concerns, but to date the journal has received no response.


Assuntos
Colite/etiologia , Colo/imunologia , Neoplasias do Colo/etiologia , Mediadores da Inflamação/metabolismo , Obesidade/complicações , Fator de Necrose Tumoral alfa/metabolismo , Animais , Anticorpos Monoclonais/farmacologia , Antineoplásicos/farmacologia , Apoptose , Azoximetano , Western Blotting , Proliferação de Células , Colite/genética , Colite/imunologia , Colite/metabolismo , Colite/patologia , Colite/prevenção & controle , Colo/efeitos dos fármacos , Colo/metabolismo , Neoplasias do Colo/genética , Neoplasias do Colo/imunologia , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Neoplasias do Colo/prevenção & controle , Sulfato de Dextrana , Modelos Animais de Doenças , Ativação Enzimática , Células HT29 , Humanos , Hiperinsulinismo/tratamento farmacológico , Hiperinsulinismo/etiologia , Hiperinsulinismo/metabolismo , Hipoglicemiantes/farmacologia , Quinase I-kappa B/metabolismo , Imuno-Histoquímica , Mediadores da Inflamação/antagonistas & inibidores , Infliximab , Insulina/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos SCID , Obesidade/genética , Obesidade/imunologia , Obesidade/metabolismo , Fosfatidilinositol 3-Quinase , Pioglitazona , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Tiazolidinedionas/farmacologia , Fatores de Tempo , Carga Tumoral , Fator de Necrose Tumoral alfa/antagonistas & inibidores
18.
PLoS One ; 7(5): e36974, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22662132

RESUMO

BACKGROUND: Wound healing is impaired in diabetes mellitus, but the mechanisms involved in this process are virtually unknown. Proteins belonging to the insulin signaling pathway respond to insulin in the skin of rats. OBJECTIVE: The purpose of this study was to investigate the regulation of the insulin signaling pathway in wound healing and skin repair of normal and diabetic rats, and, in parallel, the effect of a topical insulin cream on wound healing and on the activation of this pathway. RESEARCH DESIGN AND METHODS: We investigated insulin signaling by immunoblotting during wound healing of control and diabetic animals with or without topical insulin. Diabetic patients with ulcers were randomized to receive topical insulin or placebo in a prospective, double-blind and placebo-controlled, randomized clinical trial (NCT 01295177) of wound healing. RESULTS AND CONCLUSIONS: Expression of IR, IRS-1, IRS-2, SHC, ERK, and AKT are increased in the tissue of healing wounds compared to intact skin, suggesting that the insulin signaling pathway may have an important role in this process. These pathways were attenuated in the wounded skin of diabetic rats, in parallel with an increase in the time of complete wound healing. Upon topical application of insulin cream, the wound healing time of diabetic animals was normalized, followed by a reversal of defective insulin signal transduction. In addition, the treatment also increased expression of other proteins, such as eNOS (also in bone marrow), VEGF, and SDF-1α in wounded skin. In diabetic patients, topical insulin cream markedly improved wound healing, representing an attractive and cost-free method for treating this devastating complication of diabetes. TRIAL REGISTRATION: ClinicalTrials.gov NCT01295177.


Assuntos
Complicações do Diabetes/tratamento farmacológico , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Insulina/administração & dosagem , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Administração Tópica , Idoso , Animais , Medula Óssea/metabolismo , Quimiocina CXCL12/metabolismo , Cromonas/farmacologia , Complicações do Diabetes/metabolismo , Diabetes Mellitus Experimental/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Morfolinas/farmacologia , Óxido Nítrico Sintase Tipo III/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Ratos , Ratos Wistar , Pele/efeitos dos fármacos , Pele/metabolismo , Pele/patologia , Fator A de Crescimento do Endotélio Vascular/metabolismo
19.
Clin Cancer Res ; 17(12): 3993-4005, 2011 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-21543517

RESUMO

PURPOSE: Metformin is a widely used antidiabetic drug whose anticancer effects, mediated by the activation of AMP-activated protein kinase (AMPK) and reduction of mTOR signaling, have become noteworthy. Chemotherapy produces genotoxic stress and induces p53 activity, which can cross-talk with AMPK/mTOR pathway. Herein, we investigate whether the combination of metformin and paclitaxel has an effect in cancer cell lines. EXPERIMENTAL DESIGN: Human tumors were xenografted into severe combined immunodeficient (SCID) mice and the cancer cell lines were treated with only paclitaxel or only metformin, or a combination of both drugs. Western blotting, flow cytometry, and immunohistochemistry were then used to characterize the effects of the different treatments. RESULTS: The results presented herein show that the addition of metformin to paclitaxel leads to quantitative potentialization of molecular signaling through AMPK and a subsequent potent inhibition of the mTOR signaling pathway. Treatment with metformin and paclitaxel resulted in an increase in the number of cells arrested in the G(2)-M phase of the cell cycle, and decreased the tumor growth and increased apoptosis in tumor-bearing mice, when compared with individual drug treatments. CONCLUSION: We have provided evidence for a convergence of metformin and paclitaxel induced signaling at the level of AMPK. This mechanism shows how different drugs may cooperate to augment antigrowth signals, and suggests that target activation of AMPK by metformin may be a compelling ally in cancer treatment.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Antineoplásicos/farmacologia , Ativação Enzimática/efeitos dos fármacos , Hipoglicemiantes/farmacologia , Metformina/farmacologia , Neoplasias/metabolismo , Animais , Antimetabólitos/farmacologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Desoxiglucose/farmacologia , Sinergismo Farmacológico , Humanos , Masculino , Camundongos , Camundongos SCID , Paclitaxel/farmacologia , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/antagonistas & inibidores , Ensaios Antitumorais Modelo de Xenoenxerto
20.
Diabetes ; 60(3): 784-96, 2011 03.
Artigo em Inglês | MEDLINE | ID: mdl-21282367

RESUMO

OBJECTIVE: Insulin resistance in diet-induced obesity (DIO) is associated with a chronic systemic low-grade inflammation, and Toll-like receptor 4 (TLR4) plays an important role in the link among insulin resistance, inflammation, and obesity. The current study aimed to analyze the effect of exercise on TLR4 expression and activation in obese rats and its consequences on insulin sensitivity and signaling. RESEARCH DESIGN AND METHODS: The effect of chronic and acute exercise was investigated on insulin sensitivity, insulin signaling, TLR4 activation, c-Jun NH(2)-terminal kinase (JNK) and IκB kinase (IKKß) activity, and lipopolysaccharide (LPS) serum levels in tissues of DIO rats. RESULTS: The results showed that chronic exercise reduced TLR4 mRNA and protein expression in liver, muscle, and adipose tissue. However, both acute and chronic exercise blunted TLR4 signaling in these tissues, including a reduction in JNK and IKKß phosphorylation and IRS-1 serine 307 phosphorylation, and, in parallel, improved insulin-induced IR, IRS-1 tyrosine phosphorylation, and Akt serine phosphorylation, and reduced LPS serum levels. CONCLUSIONS: Our results show that physical exercise in DIO rats, both acute and chronic, induces an important suppression in the TLR4 signaling pathway in the liver, muscle, and adipose tissue, reduces LPS serum levels, and improves insulin signaling and sensitivity. These data provide considerable progress in our understanding of the molecular events that link physical exercise to an improvement in inflammation and insulin resistance.


Assuntos
Resistência à Insulina/fisiologia , Insulina/metabolismo , Lipopolissacarídeos/sangue , Obesidade/metabolismo , Condicionamento Físico Animal/fisiologia , Receptor 4 Toll-Like/metabolismo , Tecido Adiposo/metabolismo , Análise de Variância , Animais , Western Blotting , Dieta , Ensaio de Imunoadsorção Enzimática , Técnica Clamp de Glucose , Quinase I-kappa B/metabolismo , Interleucina-6/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Fígado/metabolismo , Masculino , Camundongos , Músculo Esquelético/metabolismo , Obesidade/fisiopatologia , Fosforilação , Distribuição Aleatória , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais
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