NGF increases Connexin-43 expression and function in pulmonary arterial smooth muscle cells to induce pulmonary artery hyperreactivity.

AIMS: Pulmonary hypertension (PH) is characterised by an increase in pulmonary arterial pressure, ultimately leading to right ventricular failure and death. We have previously shown that nerve growth factor (NGF) plays a critical role in PH. Our objectives here were to determine whether NGF controls Connexin-43 (Cx43) expression and function in the pulmonary arterial smooth muscle, and whether this mechanism contributes to NGF-induced pulmonary artery hyperreactivity. METHODS AND RESULTS: NGF activates its TrkA receptor to increase Cx43 expression, phosphorylation, and localization at the plasma membrane in human pulmonary arterial smooth muscle cells, thus leading to enhanced activity of Cx43-dependent GAP junctions as shown by Lucifer Yellow dye assay transfer and fluorescence recovery after photobleaching -FRAP- experiments. Using both in vitro pharmacological and in vivo SiRNA approaches, we demonstrate that NGF-dependent increase in Cx43 expression and activity in the rat pulmonary circulation causes pulmonary artery hyperreactivity. We also show that, in a rat model of PH induced by chronic hypoxia, in vivo blockade of NGF or of its TrkA receptor significantly reduces Cx43 increased pulmonary arterial expression induced by chronic hypoxia and displays preventive effects on pulmonary arterial pressure increase and right heart hypertrophy. CONCLUSIONS: Modulation of Cx43 by NGF in pulmonary arterial smooth muscle cells contributes to NGF-induced alterations of pulmonary artery reactivity. Since NGF and its TrkA receptor play a role in vivo in Cx43 increased expression in PH induced by chronic hypoxia, these NGF/Cx43-dependent mechanisms may therefore play a significant role in human PH pathophysiology.

[French national standard for the treatment of squamous cell carcinoma of upper aero-digestive tract - General principles of treatment]. / Référentiel national de traitement des carcinomes épidermoïdes des voies aérodigestives supérieures ­ Principes généraux de traitement.

OBJECTIVES: The management of upper aerodigestive tract cancers is a complex specialty. It is essential to provide an update to establish optimal care. At the initiative of the INCa and under the auspices of the SFORL, the scientific committee, led by Professor Béatrix Barry, Dr. Gilles Dolivet, and Dr. Dominique De Raucourt, decided to develop a reference framework aimed at defining, in a scientific and consensus-based manner, the general principles of treatment for upper aerodigestive tract cancers applicable to all sub-locations. METHODOLOGY: To develop this framework, a multidisciplinary team of practitioners was formed. A systematic analysis of the literature was conducted to produce recommendations classified by grades, in accordance with the standards of the French National Authority for Health (HAS). RESULTS: The grading of recommendations according to HAS standards has allowed the establishment of a reference for patient care based on several criteria. In this framework, patients benefit from differentiated care based on prognostic factors they present (age, comorbidities, TNM status, HPV status, etc.), conditions of implementation, and quality criteria for indicated surgery (operability, resectability, margin quality, mutilation, salvage surgery), as well as quality criteria for radiotherapy (target volume, implementation time, etc.). The role of medical and postoperative treatments was also evaluated based on specific criteria. Finally, supportive care must be organized from the beginning and throughout the patients' care journey. CONCLUSION: All collected data have led to the development of a comprehensive framework aimed at harmonizing practices nationally, facilitating decision-making in multidisciplinary consultation meetings, promoting equality in practices, and providing a state-of-the-art and reference practices for assessing the quality of care. This new framework is intended to be updated every 5 years to best reflect the latest advances in the field.

Fibrocyte accumulation in the airway walls of COPD patients.

The remodelling mechanism and cellular players causing persistent airflow limitation in COPD remain largely elusive. We have recently demonstrated that circulating fibrocytes, a rare population of fibroblast-like cells produced by the bone marrow stroma, are increased in COPD patients during an exacerbation. We aimed to quantify fibrocyte density in situ in bronchial specimens from both control subjects and COPD patients, to define associations with relevant clinical, functional and computed tomography (CT) parameters, and to investigate the effect of the epithelial microenvironment on fibrocyte survival in vitro ("Fibrochir" study).A total of 17 COPD patients and 25 control subjects, all requiring thoracic surgery, were recruited. Using co-immunostaining and image analysis, we identified CD45+ FSP1+ cells as tissue fibrocytes, and quantified their density in distal and proximal bronchial specimens. Fibrocytes, cultured from the blood samples of six COPD patients, were exposed to primary bronchial epithelial cell secretions from control subjects or COPD patients.We demonstrate that fibrocytes are increased in both distal and proximal tissue specimens of COPD patients. The density of fibrocytes is negatively correlated with lung function parameters and positively correlated with bronchial wall thickness as assessed by CT scan. A high density of distal bronchial fibrocytes predicts the presence of COPD with a sensitivity of 83% and a specificity of 70%. Exposure of fibrocytes to COPD epithelial cell supernatant favours cell survival.Our results thus demonstrate an increased density of fibrocytes within the bronchi of COPD patients, which may be promoted by epithelial-derived survival-mediating factors.

Methyl deficient diet aggravates experimental colitis in rats.

Inflammatory bowel diseases (IBD) result from complex interactions between environmental and genetic factors. Low blood levels of vitamin B12 and folate and genetic variants of related target enzymes are associated with IBD risk, in population studies. To investigate the underlying mechanisms, we evaluated the effects of a methyl-deficient diet (MDD, folate, vitamin B12 and choline) in an experimental model of colitis induced by dextran sodium sulphate (DSS), in rat pups from dams subjected to the MDD during gestation and lactation. Four groups were considered (n = 12-16 per group): C DSS(-) (control/DSS(-)), D DSS(-) (deficient/DSS(-)), C DSS(+) (control/DSS(+)) and D DSS(+) (deficient/DSS(+)). Changes in apoptosis, oxidant stress and pro-inflammatory pathways were studied within colonic mucosa. In rat pups, the MDD produced a decreased plasma concentration of vitamin B12 and folate and an increased homocysteine (7.8 ± 0.9 versus 22.6 ± 1.2 µmol/l, P < 0.001). The DSS-induced colitis was dramatically more severe in the D DSS(+) group compared with each other group, with no change in superoxide dismutase and glutathione peroxidase activity, but decreased expression of caspase-3 and Bax, and increased Bcl-2 levels. The mRNA levels of tumour necrosis factor (TNF)-α and protein levels of p38, cytosolic phospolipase A2 and cyclooxygenase 2 were significantly increased in the D DSS(+) pups and were accompanied by a decrease in the protein level of tissue inhibitor of metalloproteinases (TIMP)3, a negative regulator of TNF-α. MDD may cause an overexpression of pro-inflammatory pathways, indicating an aggravating effect of folate and/or vitamin B12 deficiency in experimental IBD. These findings suggest paying attention to vitamin B12 and folate deficits, frequently reported in IBD patients.

Attempts to quit smoking and relapse: factors associated with success or failure from the ATTEMPT cohort study.

OBJECTIVE: To identify predictors of attempts to stop smoking and predictors of relapse. METHODS: This study included 2431 smokers from pre-existing Internet panels in the United States, United Kingdom, Canada, France, and Spain. These panel members are Internet users who have registered voluntarily and agreed to participate in various online research studies. Respondents were aged 35-65 years, smoked >or= five cigarettes per day and intended to stop smoking in the next 3 months. They were followed every 3 months for up to 18 months via Internet contact on measures relating to quit attempts, smoking status, motivation to quit, nicotine cue, weight and weight concern, health-related factors, withdrawal symptoms, and smoking cessation aids. RESULTS: In this study, recent quit attempts strongly predicted future attempts, but also predicted subsequent relapse. Motivation to quit was predictive of future attempts but not of relapse/abstinence following the attempts. Relapse to smoking was associated with nicotine dependence, exposure to smoking cues, craving, withdrawal symptoms, and lack of smoking cessation aids. CONCLUSIONS: The findings lend support to a model of cessation in which level of motivation to stop generates quit attempts but plays little role in relapse. Dependence, social smoking cues, and a recently failed quit attempt are important factors in relapse.

The ATTEMPT cohort: a multi-national longitudinal study of predictors, patterns and consequences of smoking cessation; introduction and evaluation of internet recruitment and data collection methods.

AIMS: The ATTEMPT study was designed to chart the natural history of smoking cessation and associated short-term health outcomes and effects on medical resource utilization among a cohort recruited across multiple countries. This paper describes the methods for recruitment and follow-up, the baseline population characteristics of the enrolled population and 1-year response rates. DESIGN: ATTEMPT is a multi-national prospective cohort study that used the internet for subject recruitment and online assessments every 3 months for 2.5 years. SETTING: Subjects were recruited via e-mail from existing internet panels [Canada (n = 208), France (n = 201), the United Kingdom (n = 200) and the United States (n = 1400]. SUBJECTS: Panel members who were aged 35-65 years, smoked at least five cigarettes per day and at initiation stated an intention to quit smoking within the next 3 months were eligible for this study. MEASUREMENTS: Measures included: attempts to quit, smoking status, smoking history, nicotine dependence and craving, methods used to quit smoking, reasons for quitting or failing to quit smoking, short-term health effects, health resource utilization, wellbeing, concern over weight gain, confidence in preventing weight gain, body weight and demographics. In addition, in-home assessments of weight were undertaken by field staff for a random sample of US participants. FINDINGS: Country-specific recruitment was completed within 17 days. The recruitment method produced a sample with characteristics broadly similar to those found in national surveys of smokers except for higher prevalence of obesity in the US and Canadian samples and higher educational level. At the end of 1 year the response rate was 52%, and there was little evidence of differential loss to follow-up by key subject characteristics. Weight reported in the survey was found to correlate highly with weight measured during in-home visits. CONCLUSION: This paper demonstrates the feasibility of enrolling and following a diverse cohort of smokers for self-reported health and behaviour measures via the internet.