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BACKGROUND & AIMS: Individuals with Lynch syndrome (LS) have a high lifetime risk of developing colorectal cancer (CRC) due to genetic alterations. Nutrition is one of the main modifiable risk factors for sporadic CRC, however this has not been established in LS patients. The present study aimed to give a detailed overview of dietary intakes in individuals with LS, and associated individual characteristics. METHODS: Dietary behaviours of individuals with LS from the AAS-Lynch clinical trial (2017-2022) were obtained using a food frequency questionnaire. Dietary intakes, food group consumption and overall diet quality (dietary patterns, adherence to the Mediterranean diet) were described according to sociodemographic, anthropometric and clinical characteristics, and compared to participants without LS from the NutriNet-Santé study (matched on sex, age, BMI and region). RESULTS: 280 individuals with LS were included in this analysis and matched with 547 controls. Compared to controls, LS patients consumed less fibre, legumes, fruit and vegetables and more red and processed meat (all p < 0.01). They also had a lower Mediterranean diet score (p = 0.002). Among LS patients, men, younger patients, or those with disadvantaged situation had a diet of poorer nutritional quality with lower adherence to a "Healthy" diet (all p ≤ 0.01). LS Patients with prevalent CRC had a higher consumption of dairy products than recommended, while those with prevalent adenoma consumed more vegetables, and less sugar and sweets (all p ≤ 0.01). CONCLUSIONS: Although patients with LS were aware of their high lifetime risk of developing cancer, their diets were not optimal and included nutritional risk factors associated to CRC.
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Neoplasias Colorrectales Hereditarias sin Poliposis , Dieta Mediterránea , Masculino , Humanos , Verduras , Factores de Riesgo , Dieta SaludableRESUMEN
PURPOSE: Numerous studies, including our previous work with lemon juice, have reported that low-pH meals reduce the glycemic response to starchy foods. However, the underlying mechanism is not yet understood. Tea, for its polyphenol content, has also been investigated. The main objective of this research was to concurrently study gastric emptying, appetite perceptions and glycemic responses to bread consumed with water, tea, or lemon juice. METHODS: In this randomized, crossover intervention, ten participants consumed equal portions of bread (100 g) with 250 mL of water, water-diluted lemon juice, or black tea at breakfast. Gastric volumes, blood glucose concentrations and appetite perceptions were alternately assessed over 180 min using magnetic resonance imaging, the finger-prick method and visual analogue scales, respectively. RESULTS: Compared to water, lemon juice led to a 1.5 fold increase of the volume of gastric contents, 30 min after the meal (454.0 ± 18.6 vs. 298.4 ± 19.5 mL, [Formula: see text] ± SEM P < 0.00001). Gastric emptying was also 1.5 times faster (P < 0.01). Conversely, lemon juice elicited a lower glycemic response than water (blood glucose concentrations at t = 55 min were 35% lower, P = 0.039). Tea had no effect. Changes in appetite perceptions and gastric volumes correlated well, but with no significant differences between the meals. CONCLUSIONS: Lemon juice lowered the glycemic response and increased both gastric secretions and emptying rate. The results are compatible with the hypothesis that the reduction of the glycemic response is mainly due to the interruption of starch hydrolysis via the acid-inhibition of salivary α-amylase. TRIAL REGISTRATION NUMBER: NCT03265392, August 29, 2017.
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Glucemia , Pan , Estudios Cruzados , Vaciamiento Gástrico/fisiología , Humanos , Imagen por Resonancia Magnética , Periodo Posprandial , Respuesta de Saciedad , Té , AguaRESUMEN
BACKGROUND: Gastrointestinal angiodysplasias are vascular malformations that often cause red blood cell transfusion-dependent anaemia. Several studies suggest that somatostatin analogues might decrease rebleeding rates, but the true effect size is unknown. We therefore aimed to investigate the efficacy of somatostatin analogues on red blood cell transfusion requirements of patients with gastrointestinal angiodysplasias and to identify subgroups that might benefit the most from somatostatin analogue therapy. METHODS: We did a systematic review and individual patient data meta-analysis. We searched MEDLINE, Embase, and Cochrane on Jan 15, 2016, with an updated search on April 25, 2021. All published randomised controlled trials and cohort studies that reported on somatostatin analogue therapy in patients with gastrointestinal angiodysplasias were eligible for screening. We excluded studies without original patient data, single case reports, small case series (ie, <10 participants), studies in which patients had a specific aetiology of gastrointestinal angiodysplasias, and studies in which somatostatin analogue therapy was initiated simultaneously with other treatment modalities. Authors of eligible studies were invited to share individual patient data. Aggregated data was used if individual patient data were not provided. The primary outcome was the mean reduction in the number of red blood cell transfusions during somatostatin analogue therapy, compared with baseline, expressed as the incidence rate ratio (IRR) and absolute mean decrease. We defined patients as either good responders (≥50% reduction in the number of red blood cell transfusions) or poor responders (<50% reduction). A mixed-effects negative binomial regression was used to account for clustering of patients and skewness in data. This study was registered in the International Prospective Register of Systematic Reviews (PROSPERO), number CRD42020213985. FINDINGS: We identified 11 eligible studies (one randomised controlled trial and ten cohort studies) of moderate-to-high quality and obtained individual patient data from the authors of nine (82%) studies. The remaining two (18%) studies provided sufficient information in the published manuscript to extract individual patient data. In total, we analysed data from 212 patients. Somatostatin analogues reduced the number of red blood cell transfusions with an IRR of 0·18 (95% CI 0·14-0·24; p<0·0001) during a median treatment duration of 12 months (IQR 6·0-12·0) and follow-up period of 12 months (12·0-12·0), correlating with a mean absolute decrease in the number of red blood cell transfusions from 12·8 (95% CI 10·4-15·8) during baseline to 2·3 (1·9-2·9) during follow-up-ie, a reduction of 10·5 red blood cell transfusions (p<0·0001). 177 (83%) of 212 patients had a good response to somatostatin analogue therapy (defined as at least a 50% reduction in the number of red blood cell transfusions). Heterogeneity across studies was moderate (I2=53%; p=0·02). Location of gastrointestinal angiodysplasias in the stomach compared with angiodysplasias in the small bowel and colon (IRR interaction 1·92 [95% CI 1·13-3·26]; p=0·02) was associated with worse treatment response. Octreotide was associated with a better treatment response than lanreotide therapy (IRR interaction 2·13 [95% CI 1·12-4·04]; p=0·02). The certainty of evidence was high for the randomised controlled trial and low for the ten cohort studies. Adverse events occurred in 38 (18%) of 212 patients receiving somatostatin analogue therapy, with ten (5%) discontinuing this therapy because of adverse events. The most common adverse events were loose stools (seven [3%] of 212), cholelithiasis (five [2%]), flatulence (four [2%]), and administration site reactions (erythema, five [2%]). INTERPRETATION: Somatostatin analogue therapy is safe and effective in most patients with red blood cell transfusion-dependent bleeding due to gastrointestinal angiodysplasias. Somatostatin analogue therapy is more effective in patients with angiodysplasias located in the small bowel and colon, and octreotide therapy seems to be more effective than lanreotide therapy. FUNDING: The Netherlands Organisation for Health Research and Development and the Radboud University Medical Center.
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Angiodisplasia/tratamiento farmacológico , Fármacos Gastrointestinales/uso terapéutico , Enfermedades Gastrointestinales/tratamiento farmacológico , Octreótido/uso terapéutico , Péptidos Cíclicos/uso terapéutico , Somatostatina/análogos & derivados , Angiodisplasia/complicaciones , Transfusión de Eritrocitos/estadística & datos numéricos , Enfermedades Gastrointestinales/complicaciones , Hemorragia Gastrointestinal/etiología , Hemorragia Gastrointestinal/terapia , Humanos , Somatostatina/uso terapéutico , Resultado del TratamientoRESUMEN
PURPOSE: The inhibition of enzymes that hydrolyze starch during digestion could constitute an opportunity to slow down the release, and ultimately the uptake, of starch-derived glucose. Simple dietary approaches consisting in pairing starch-rich foods with beverages that have the capacity to inhibit such enzymes could be an effective and easily implementable strategy. The objective of this work was to test the impact of black tea and lemon juice on the glycemic response to bread and subsequent energy intake in healthy adults. METHODS: A randomized crossover study was conducted with equal portions of bread (100 g) and 250 ml of water, black tea or lemon juice. Capillary blood glucose concentrations were monitored during 180 min using the finger-prick method. Ad libitum energy intake was assessed 3 h later. RESULTS: Tea had no effect on the glycemic response. Lemon juice significantly lowered the mean blood glucose concentration peak by 30% (p < 0.01) and delayed it more than 35 min (78 vs. 41 min with water, p < 0.0001). None of the tested beverages had an effect on ad libitum energy intake. CONCLUSION: These results are in agreement with previous in vitro studies showing that lowering the pH of a meal can slow down starch digestion through premature inhibition of salivary α-amylase. Furthermore, the effect of lemon juice was similar to what has been repeatedly observed with vinegar and other acidic foods. Including acidic beverages or foods in starchy meals thus appears to be a simple and effective strategy to reduce their glycemic impact.
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Glucemia , Pan , Adulto , Estudios Cruzados , Jugos de Frutas y Vegetales , Índice Glucémico , Humanos , Insulina , Periodo PosprandialRESUMEN
Lynch syndrome (LS) is the most common cause of inherited colorectal cancer (CRC) and confers a high lifetime risk of CRC estimated to be up to 60%. Colonoscopy is recommended every 2 years in LS patients above the 20-25-year-old age bracket, and every year when colonic neoplasia has been detected. Efficient chemoprevention has the potential to represent a cost-effective intervention in these high-risk patients and could allow a delay in colonoscopy surveillance. Several epidemiological studies have shown that regular use of low dose aspirin is associated with a 20 to 30% reduction in the risk of sporadic colonic adenomas and colorectal cancer regardless of family risk. However, in recent large randomized trials in specific populations, aspirin use showed no protection for colorectal cancer. A prospective randomized CAPP-2 trial evaluated the effect of aspirin use in LS patients. The primary analysis of this trial showed no significant decrease in CRC in LS patients under daily aspirin. However, a preplanned secondary analysis after an extended follow-up showed a significant reduced risk of CRC in the aspirin group in the per-protocol analysis. The real effect and clinical benefit of aspirin are still to be consolidated in this population. The AAS-Lynch trial-a prospective, multicentric, double-blind, placebo-controlled, randomized clinical trial-was designed to investigate if daily aspirin therapy, at a dose of 100 or 300 mg, would decrease the occurrence or recurrence of colorectal adenomas in patients under 75 years of age, compared with placebo. TRIAL REGISTRATION: ClinicalTrials.gov NCT02813824 . Registered on 27 June 2016. The trial was prospectively registered.
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Adenoma , Neoplasias Colorrectales Hereditarias sin Poliposis , Neoplasias Colorrectales , Adenoma/diagnóstico , Adenoma/prevención & control , Adulto , Aspirina/efectos adversos , Quimioprevención , Neoplasias Colorrectales/diagnóstico , Neoplasias Colorrectales/prevención & control , Neoplasias Colorrectales Hereditarias sin Poliposis/diagnóstico , Neoplasias Colorrectales Hereditarias sin Poliposis/genética , Neoplasias Colorrectales Hereditarias sin Poliposis/prevención & control , Método Doble Ciego , Humanos , Estudios Multicéntricos como Asunto , Recurrencia Local de Neoplasia , Estudios Prospectivos , Ensayos Clínicos Controlados Aleatorios como Asunto , Adulto JovenRESUMEN
BACKGROUND: Gastrointestinal angiodysplasias (GIADs) could be responsible for recurrent bleeding and severe anemia. Somatostatin analogs could reduce transfusion requirements in these patients but no randomized controlled study is available. The main objective of the ANGIOPAS phase II double-blinded randomized, noncomparative study was to assess the effectiveness of pasireotide-LAR in reducing transfusion requirements in patients with refractory GIADs bleeding. METHODS: A total of 22 patients with transfusion requirements ⩾6 units of packed red blood cells (pRBCs) during the 6 months prior to inclusion were randomized to receive pasireotide-LAR 60 mg (n = 10) or placebo (n = 12) every 28 days for 6 months. Patients were then followed for an additional 6 months after stopping treatment. RESULTS: The pasireotide-LAR and placebo groups were equivalent for age, sex, comorbidities and transfusion requirement during the reference period (median 13 and 9.5 pRBCs). A 50 and 83% success rate (success defined as a decrease of at least 30% of transfused pRBCs) was observed in the pasireotide-LAR arm in the Intent to Treat (ITT) and per protocol (PP) analysis respectively. The need for transfusion during the intervention period was 3 pRBC units in the pasireotide-LAR group (range 0-26) and 11.5 pRBC units in the placebo group (range 0-23). Overall, three cases with glycemic control impairment were observed in the pasireotide-LAR group including one de novo diabetes. CONCLUSION: This double-blinded noncomparative randomized phase II study suggests, for the first time, the effectiveness of pasireotide-LAR 60 mg every 28 days to decrease the transfusion requirement in patients with recurrent bleeding due to GIADs.
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PURPOSE: Perioperative chemotherapy with 5-fluorouracil and cisplatin, with or without epirubicin, improves overall survival in resectable gastroesophageal junction and gastric adenocarcinoma. The aim of this retrospective multicenter study was to evaluate the safety and efficacy of perioperative chemotherapy with a FOLFOX-based regimen. PATIENTS AND METHODS: We enrolled patients with resectable gastric or gastroesophageal adenocarcinoma, who had at least 3 cycles of a pre-operative FOLFOX-based regimen. The primary end point was the feasibility of the peri-operative chemotherapy. RESULTS: We enrolled 109 patients from 2007 to 2012 in 12 centres. Their median age was 66, 67% were men and 73% had gastric tumours. The median number of chemotherapy courses was 6 with a median of 4 pre-operative cycles and 2 post-operative cycles. Twenty-three patients received at least 8 cycles of chemotherapy. In univariate analysis, the Karnofsky index at inclusion was the only factor associated with 8 cycles of chemotherapy. An R0 resection was achieved in 100 patients (95.2%). CONCLUSION: The FOLFOX-based perioperative regimen achieves favourable results in real life practice. The optimal number of chemotherapy cycle remains to be determined. FOLFOX regimen may be used as an alternative treatment option to a cisplatin-based regimen in resectable gastroesophageal adenocarcinoma. A prospective randomized trial is needed to confirm these results.
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Adenocarcinoma/terapia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Procedimientos Quirúrgicos del Sistema Digestivo , Neoplasias Esofágicas/terapia , Neoplasias Gástricas/terapia , Adenocarcinoma/patología , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias Esofágicas/patología , Femenino , Fluorouracilo/uso terapéutico , Francia , Humanos , Estimación de Kaplan-Meier , Leucovorina/uso terapéutico , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/epidemiología , Compuestos Organoplatinos/uso terapéutico , Periodo Perioperatorio , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Neoplasias Gástricas/patología , Tasa de SupervivenciaRESUMEN
The paradoxical coexistence of spontaneous tumor antigen-specific immune responses with progressive disease in cancer patients furthers the need to dissect the molecular pathways involved in tumor-induced T cell dysfunction. In patients with advanced melanoma, we have previously shown that the cancer-germline antigen NY-ESO-1 stimulates spontaneous NY-ESO-1-specific CD8(+) T cells that up-regulate PD-1 expression. We also observed that PD-1 regulates NY-ESO-1-specific CD8(+) T cell expansion upon chronic antigen stimulation. In the present study, we show that a fraction of PD-1(+) NY-ESO-1-specific CD8(+) T cells in patients with advanced melanoma up-regulates Tim-3 expression and that Tim-3(+)PD-1(+) NY-ESO-1-specific CD8(+) T cells are more dysfunctional than Tim-3(-)PD-1(+) and Tim-3(-)PD-1(-) NY-ESO-1-specific CD8(+) T cells, producing less IFN-γ, TNF, and IL-2. Tim-3-Tim-3L blockade enhanced cytokine production by NY-ESO-1-specific CD8(+) T cells upon short ex vivo stimulation with cognate peptide, thus enhancing their functional capacity. In addition, Tim-3-Tim-3L blockade enhanced cytokine production and proliferation of NY-ESO-1-specific CD8(+) T cells upon prolonged antigen stimulation and acted in synergy with PD-1-PD-L1 blockade. Collectively, our findings support the use of Tim-3-Tim-3L blockade together with PD-1-PD-L1 blockade to reverse tumor-induced T cell exhaustion/dysfunction in patients with advanced melanoma.
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Antígenos CD/inmunología , Proteínas Reguladoras de la Apoptosis/inmunología , Linfocitos T CD8-positivos/inmunología , Melanoma/inmunología , Proteínas de la Membrana/inmunología , Antígenos CD/biosíntesis , Antígenos de Neoplasias/inmunología , Proteínas Reguladoras de la Apoptosis/biosíntesis , Linfocitos T CD8-positivos/metabolismo , Linfocitos T CD8-positivos/patología , Epítopos de Linfocito T/inmunología , Receptor 2 Celular del Virus de la Hepatitis A , Humanos , Inmunidad Celular , Interferón gamma/biosíntesis , Interferón gamma/inmunología , Interleucina-2/biosíntesis , Interleucina-2/inmunología , Melanoma/patología , Proteínas de la Membrana/biosíntesis , Receptor de Muerte Celular Programada 1 , Factor de Necrosis Tumoral alfa/biosíntesis , Factor de Necrosis Tumoral alfa/inmunología , Regulación hacia ArribaRESUMEN
We investigated the role of heme oxygenase-1 (HO-1), a powerful anti-inflammatory and anti-oxidant enzyme, in modulating cigarette smoke (CS)-induced mucus secretion. In both rats and mice, 5-day CS exposure increased HO-1 expression and activity, mucus secretion, MUCIN 5AC (MUC5AC) gene and protein expression, and local inflammation, along with up-regulation of dual oxidase 1 gene expression and both the activity and phosphorylation of the epidermal growth factor receptor, which is involved in MUC5AC induction. Pharmacological induction of HO-1 prevented these actions and inhibition of HO-1 expression by a specific siRNA potentiated them. In French participants to the European Community Respiratory Health Survey II (n = 210, 30 to 53 years of age, 50% males) exposed to CS, a significant increase in the percentage of participants with chronic sputum was observed in those harboring at least one allele with a long (GT)(n) in the HO-1 promoter gene (>33 repeats), which is associated with a low level of HO-1 protein expression, compared with those with a short number of (GT)n repeats (21.7% versus 8.6%, P = 0.047). No such results were observed in those who had never smoked (n = 297). We conclude that HO-1 has a significant protective effect against airway mucus hypersecretion in animals and humans exposed to CS.
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Hemo-Oxigenasa 1/metabolismo , Pulmón/enzimología , Pulmón/metabolismo , Moco/metabolismo , Fumar/efectos adversos , Adulto , Animales , Regulación hacia Abajo/efectos de los fármacos , Oxidasas Duales , Inducción Enzimática/efectos de los fármacos , Femenino , Hemo-Oxigenasa 1/biosíntesis , Hemo-Oxigenasa 1/genética , Hemina/farmacología , Humanos , Técnicas In Vitro , Inflamación , Pulmón/patología , Masculino , Ratones , Ratones Endogámicos BALB C , Mucina 5AC , Mucinas/metabolismo , NADPH Oxidasas/genética , NADPH Oxidasas/metabolismo , Regiones Promotoras Genéticas/genética , Ratas , Ratas Sprague-Dawley , Secuencias Repetitivas de Ácidos Nucleicos/genética , Esputo/enzimologíaRESUMEN
OBJECTIVE: To determine the consequences of pharmacologic up-regulation of heme oxygenase 1 (HO-1), and inhibition of HO-1 by injection of an anti-HO-1 small interfering RNA (siRNA), in vivo in the acute phase of a mouse model of nonautoimmune arthritis. METHODS: In the K/BxN mouse serum transfer model, which mimics human inflammatory arthritis without lymphocyte influence, HO-1 was up-regulated by intraperitoneal injection of cobalt protoporphyrin IX (CoPP), a potent pharmacologic inducer, and was inhibited using a specific siRNA. The clinical progress of arthritis was monitored by measurement of paw thickness. Interleukin-1beta (IL-1beta), IL-6, tumor necrosis factor alpha (TNFalpha), serum antioxidant, and nitric oxide (NO) levels, prostaglandin E(2) (PGE(2)) production, and matrix metalloproteinase 9 (MMP-9) activity were measured in serum. At the end of the experiments, joints were examined for immunohistopathologic changes. RESULTS: Intraperitoneal injection of CoPP alleviated disease symptoms, such as joint swelling, cartilage degradation, and proliferation of inflammatory tissue in joints, in the acute phase of inflammatory arthritis. The CoPP-induced expression of HO-1 in the joints and liver was associated with marked decreases in IL-1beta, IL-6, and TNFalpha levels, PGE(2) secretion, and MMP-9 activity in serum, and with a marked increase in systemic antioxidant activity. In contrast, NO production in serum and inducible NO synthase expression in chondrocytes were not affected by HO-1 induction. Specific inhibition of HO-1 by in vivo delivery of anti-HO-1 siRNA repressed the protective effects. CONCLUSION: Our data provide the first evidence that pharmacologically induced up-regulation of HO-1 triggers a robust protective antiinflammatory response in a model of nonautoimmune arthritis in mice. This suggests that exogenously induced HO-1 may have potential as therapy in the acute phase of inflammatory arthritis in humans.
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Artritis Experimental/enzimología , Artritis Experimental/terapia , Hemo-Oxigenasa 1/biosíntesis , Protoporfirinas/farmacología , Animales , Artritis Experimental/sangre , Biomarcadores/sangre , Modelos Animales de Enfermedad , Activación Enzimática/efectos de los fármacos , Inducción Enzimática/efectos de los fármacos , Inducción Enzimática/genética , Inhibidores Enzimáticos/farmacología , Hemo-Oxigenasa 1/antagonistas & inhibidores , Hemo-Oxigenasa 1/genética , Miembro Posterior/efectos de los fármacos , Miembro Posterior/patología , Inyecciones Intraperitoneales , Articulaciones/efectos de los fármacos , Articulaciones/enzimología , Articulaciones/patología , Hígado/efectos de los fármacos , Hígado/enzimología , Hígado/patología , Pulmón/efectos de los fármacos , Pulmón/enzimología , Pulmón/patología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos NOD , Ratones Transgénicos , ARN Interferente Pequeño/farmacología , Regulación hacia ArribaRESUMEN
OBJECTIVES: To investigate the presence and functionality of oestrogen receptor alpha (ERalpha) in interleukin (IL)1beta-treated rabbit articular chondrocytes in culture, and to determine the mechanisms of 17beta oestradiol (E2) effects on IL1beta-induced inducible nitric oxide synthase (iNOS) expression. METHODS: The presence and functionality of ERalpha were investigated by immunocytochemistry and transient expression of an E2-responsive reporter construct. iNOS expression and production were determined by transient expression of a chimeric iNOS promoter-luciferase construct and protein immunoblotting. Nitric oxide (NO) production was determined by the Griess reaction. DNA-binding activities of nuclear factor-kappaB (NF-kappaB) and activated protein 1 were determined by electrophoretic mobility shift assay (EMSA)-ELISA assays. Nuclear translocation of p65 was studied by immunocytochemistry. RESULTS: ERalpha was identified in the nucleus of chondrocytes. ERalpha efficiently transactivated a transiently expressed E2-responsive construct. On IL1beta treatment, ERalpha partially diffused from its nuclear localisation into the cytoplasm and its transactivation ability was impaired. Nevertheless, E2, tamoxifen and raloxifene efficiently inhibited IL1beta-induced NO production (-34%, -31% and -36%, respectively). E2 decreased IL1beta-induced iNOS protein expression (-40%). Transient expression of an iNOS promoter construct strongly suggested that iNOS expression was inhibited at the transcriptional level, and EMSA-ELISA assays showed that E2 reduced (-60%) the IL1beta-induced p65 DNA-binding capacity. Finally, the p65 nuclear translocation induced by IL1beta was also strongly decreased by E2. CONCLUSIONS: Our data support a reciprocal antagonism between oestrogens and IL1beta, ultimately resulting in the decrease of cytokine-dependent NO production through transcriptional inhibition of iNOS expression. This effect was associated with selective inhibition of p65 DNA binding and nuclear translocation.
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Cartílago Articular/citología , Condrocitos/enzimología , Estradiol/farmacología , Receptor alfa de Estrógeno/fisiología , Interleucina-1beta/antagonistas & inhibidores , Óxido Nítrico Sintasa/metabolismo , Animales , Cartílago Articular/efectos de los fármacos , Cartílago Articular/enzimología , Cartílago Articular/metabolismo , Células Cultivadas , Condrocitos/efectos de los fármacos , Condrocitos/metabolismo , Relación Dosis-Respuesta a Droga , Receptor alfa de Estrógeno/metabolismo , Femenino , Interleucina-1beta/farmacología , FN-kappa B/metabolismo , FN-kappa B/fisiología , Óxido Nítrico/biosíntesis , Óxido Nítrico Sintasa/genética , Regiones Promotoras Genéticas , Conejos , Transducción de Señal/efectos de los fármacos , Activación Transcripcional/efectos de los fármacos , Translocación Genética/efectos de los fármacosRESUMEN
Proteoglycan production is one of the major extracellular matrix components implicated in the dynamic process of intervertebral disc degeneration. Mechanical stress is an important modulator of the degeneration, but the underlying molecular mechanism at the proteoglycan level remains unclear. The aim of this work was to study the regulation of proteoglycan production by cyclic tensile stretch applied to intervertebral disc annulus fibrosus cells. Matrix metalloproteinases do not seem to be implicated in the regulation of proteoglycan production. By contrast, nitrite oxide production is induced by cyclic tensile stretch, in a time, intensity, and frequency dependant manner. Using a non-specific nitric oxide synthases inhibitor [NG-methyl-L-arginine (L-NMA)], we suppress totally the inhibition of proteoglycan production induced by cyclic tensile stretch suggesting the implication of nitric oxide synthases in the observed phenomenon. Introducing the transcriptional inhibitor 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole or a more specific inhibitor of nitric oxide synthases II [N-iminoethyl-L-lysine (L-NIL)] did not affect the decreased proteoglycan production, which suggests a post-translational regulation. In contrast, N-omega nitro-L-arginine (L-NNA) a more specific inhibitor of NOS I and III abrogated the cyclic tensile stretch-dependant inhibition of proteoglycan production. These results suggest that cyclic tensile stretch regulates proteoglycan production through a post-translational mechanism involving nitrite oxide. This result could be of interest in the development of local therapeutic strategies aimed at controlling intervertebral disc degeneration.
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Disco Intervertebral/metabolismo , Procesamiento Proteico-Postraduccional , Proteoglicanos/biosíntesis , Animales , Células Cultivadas , Condrocitos/metabolismo , Condrocitos/fisiología , Disco Intervertebral/citología , Metaloproteinasas de la Matriz/metabolismo , Mecanotransducción Celular/fisiología , Óxido Nítrico Sintasa/fisiología , Nitritos/metabolismo , Proteoglicanos/genética , Conejos , Estrés MecánicoRESUMEN
OBJECTIVE: To determine whether peroxisome proliferator-activated receptor alpha (PPARalpha) agonists protect chondrocytes against the effects of interleukin-1beta (IL-1beta). METHODS: PPARalpha expression and function in cultured rabbit articular chondrocytes were studied by Northern blotting, electrophoretic mobility shift assay, and transient expression of a luciferase reporter construct bearing the human IL-1 receptor antagonist (Il-1Ra) gene promoter. Chondrocytes were incubated in vitro with IL-1beta alone or in combination with CloFibrate (CloF) or other PPAR ligands. Proteoglycans were evaluated by 35S-sulfate incorporation, matrix metalloproteinase (MMP) levels were assessed by zymography and enzyme-linked immunosorbent assay (ELISA), and MMP messenger RNA (mRNA) levels were measured by Northern blotting and real-time reverse transcriptase-polymerase chain reaction. IL-1beta and IL-1Ra soluble contents were measured by ELISA. RESULTS: CloF counteracted IL-1beta-induced 35S-proteoglycan degradation, gelatinolytic activity, and MMP-1, -3, and -13 mRNA expression. CloF also maximized IL-1beta-induced endogenous production of soluble IL-1Ra (sIL-1Ra). This stimulating effect on IL-1Ra gene expression was shown, by transient expression assay, to be transcriptional. Inhibition of sIL-1Ra expression by a specific small interfering RNA suppressed the effect of CloF on IL-1beta-induced MMP expression. The stimulatory effect of CloF was enhanced by cotransfection with wild-type PPARalpha and abolished by a dominant-negative PPARalpha mutant. Fenofibrate and WY-14643 displayed a similar stimulating effect on the IL-1Ra promoter, while rosiglitazone did not. Two PPAR response elements, an NF-kappaB-binding site, and a CCAAT/enhancer binding protein-binding site were identified in the IL-1Ra promoter. All 4 sites were necessary for mediation of the effects of CloF. CONCLUSION: Our findings support the notion that there is a PPARalpha-dependent mechanism that inhibits IL-1beta function in chondrocytes, which operates via an increase in sIL-1Ra production.
Asunto(s)
Condrocitos/inmunología , PPAR alfa/fisiología , Sialoglicoproteínas/biosíntesis , Animales , Proteína de la Matriz Oligomérica del Cartílago , Células Cultivadas , Condrocitos/efectos de los fármacos , Condrocitos/metabolismo , Clofibrato/farmacología , Proteínas de la Matriz Extracelular/metabolismo , Glicoproteínas/metabolismo , Proteína Antagonista del Receptor de Interleucina 1 , Interleucina-1/antagonistas & inhibidores , Interleucina-1/fisiología , Proteínas Matrilinas , ConejosRESUMEN
Degeneration of the intervertebral disc is the main pathophysiological process implicated in low back pain and is a prerequisite to disc herniation. Clinically, mechanical forces are important modulators of the degeneration, but the underlying molecular mechanism is not known and needs investigation to identify the biological target. The aim of this work was to study, at the molecular level, the effects of cyclic tensile stretch (CTS) on the production of proteoglycan by intervertebral disc annulus fibrosus cells since proteoglycans seem to be implicated in the dynamic process of intervertebral disc degeneration. Such cells of rabbit were cultured at high density on plates with a flexible bottom. CTS was applied with use of a pressure-operated instrument to deform the plates. With CTS at 1% elongation (1 Hz frequency), the level of (35)S-labeled neosynthesized proteoglycans that accumulated in the cellular pool or were secreted in the culture medium did not change, but at 5% elongation, the level was significantly reduced after 8 h of stimulation (30 and 21%, respectively) and further reduced at 24 h (43 and 41%, respectively). Introducing the protein synthesis inhibitor cycloheximide had no effect on this result. Neither aggrecan and biglycan expression nor proteoglycan physical properties were modified. The level of nitrite oxide production significantly increased by 3.5 times after 8 h of 5% elongation. Introducing the nitric oxide synthase (NOS) inhibitors N(G)-methyl-l-arginine or N-omega nitro-l-arginine diminished the effects of CTS on the production of nitrite oxide and proteoglycans. By contrast, introducing N-iminoethyl-l-lysine (a more specific inhibitor of inductible NOS [iNOS]) had little or no effect. Taken together, these results suggest that cNOS activation seems to be more implicated in the 5% CTS modulation of proteoglycan production than iNOS activation. These results suggest that CTS can help regulate the intervertebral disc matrix by decreasing proteoglycan production through a post-translational regulation involving nitrite oxide. This result could be of interest in the development of local therapeutic strategies aimed at controlling intervertebral disc degeneration.