Crohn's disease-associated polymorphism within the PTPN2 gene affects muramyl-dipeptide-induced cytokine secretion and autophagy.

BACKGROUND: The single nucleotide polymorphism (SNP) rs2542151 within the gene locus region encoding protein tyrosine phosphatase non-receptor type 2 (PTPN2) has been associated with Crohn's disease (CD), ulcerative colitis (UC), type-I diabetes, and rheumatoid arthritis. We have previously shown that PTPN2 regulates mitogen-activated protein kinase (MAPK) signaling and cytokine secretion in human THP-1 monocytes and intestinal epithelial cells (IEC). Here, we studied whether intronic PTPN2 SNP rs1893217 regulates immune responses to the nucleotide-oligomerization domain 2 (NOD2) ligand, muramyl-dipeptide (MDP). MATERIALS AND METHODS: Genomic DNA samples from 343 CD and 663 non-IBD control patients (male and female) from a combined German, Swiss, and Polish cohort were genotyped for the presence of the PTPN2 SNPs, rs2542151, and rs1893217. PTPN2-variant rs1893217 was introduced into T(84) IEC or THP-1 cells using a lentiviral vector. RESULTS: We identified a novel association between the genetic variant, rs1893217, located in intron 7 of the PTPN2 gene and CD. Human THP-1 monocytes carrying this variant revealed increased MAPK activation as well as elevated mRNA expression of T-bet transcription factor and secretion of interferon-γ in response to the bacterial wall component, MDP. In contrast, secretion of interleukin-8 and tumor necrosis factor were reduced. In both, T(84) IEC and THP-1 monocytes, autophagosome formation was impaired. CONCLUSIONS: We identified a novel CD-associated PTPN2 variant that modulates innate immune responses to bacterial antigens. These findings not only provide key insights into the effects of a functional mutation on a clinically relevant gene, but also reveal how such a mutation could contribute to the onset of disease.

Les biomarqueurs prédictifs dans le cancer colorectal [Predictive biomarkers in colorectal cancer]

While for many years the diagnosis and therapy of colon cancer did not change drastically, recently new drugs (irinotecan and oxaliplatin, used in adjuvant or neo-adjuvant approaches) and even more recently the introduction of therapies targeting the epidermal growth factor receptor (EGFR) through the monoclonal antibodies cetuximab and panitumumab, are revolutionizing the field. The finding that only patients with a tumor with a wild type (non mutated) KRAS gene respond to anti-EGFR therapy has also affected the way pathologists address colorectal cancer. Molecular analysis of the KRAS gene has become almost a routine in a very short period of time. Pathologists will have to be prepared for a new era: from standard morphology based diagnostic procedures to the prediction of response to therapy using molecular tools.

Diabète de type 2: n'oubliez pas les troubles du comportement alimentaire [Patient with type 2 diabetes: don't forget eating disorders!]

The coexistence of diabetes and eating disorder (ED) is more prevalent than we think; indeed it seems to occur in 10 to 20% of cases. Therefore ED deserve attention to be detected and treated in order to permit a decreased in morbidity and better outcomes in body weight loss. The association of type 2 diabetes and ED is frequently seen in younger, overweighed or obese patients suffering of at least one psychiatric co-morbidities and frequently in a difficult psychosocial setting. To succeed in ED treatment, a multidisciplinary and specialised team in eating disorder is requested, however these patients are highly fragile and complex and therapeutic failure has to be feared.

Adipocytokines, Hepatic and Inflammatory Biomarkers and Incidence of Type 2 Diabetes. The CoLaus Study.

CONTEXT: There is contradictory information regarding the prognostic importance of adipocytokines, hepatic and inflammatory biomarkers on the incidence of type 2 diabetes. The objective was to assess the prognostic relevance of adipocytokine and inflammatory markers (C-reactive protein - CRP; interleukin-1beta - IL-1β; interleukin-6- IL-6; tumour necrosis factor-^5; - TNF-^5;; leptin and adiponectin) and gamma-glutamyl transpeptidase (γGT) on the incidence of type 2 diabetes. METHODS: Prospective, population-based study including 3,842 non-diabetic participants (43.3% men, age range 35 to 75 years), followed for an average of 5.5 years (2003-2008). The endpoint was the occurrence of type 2 diabetes. RESULTS: 208 participants (5.4%, 66 women) developed type 2 diabetes during follow-up. On univariate analysis, participants who developed type 2 diabetes had significantly higher baseline levels of IL-6, CRP, leptin and γGT, and lower levels of adiponectin than participants who remained free of type 2 diabetes. After adjusting for a validated type 2 diabetes risk score, only the associations with adiponectin: Odds Ratio and (95% confidence interval): 0.97 (0.64-1.47), 0.84 (0.55-1.30) and 0.64 (0.40-1.03) for the second, third and forth gender-specific quartiles respectively, remained significant (P-value for trend = 0.05). Adding each marker to a validated type 2 diabetes risk score (including age, family history of type 2 diabetes, height, waist circumference, resting heart rate, presence of hypertension, HDL cholesterol, triglycerides, fasting glucose and serum uric acid) did not improve the area under the ROC or the net reclassification index; similar findings were obtained when the markers were combined, when the markers were used as continuous (log-transformed) variables or when gender-specific quartiles were used. CONCLUSION: Decreased adiponectin levels are associated with an increased risk for incident type 2 diabetes, but they seem to add little information regarding the risk of developing type 2 diabetes to a validated risk score.

Viral suppression rates in salvage treatment with raltegravir improved with the administration of genotypic partially active or inactive nucleoside/tide reverse transcriptase inhibitors.

BACKGROUND: Nucleoside reverse transcriptase inhibitors (NRTIs) are often administered in salvage therapy even if genotypic resistance tests (GRTs) indicate high-level resistance, but little is known about the benefit of these additional NRTIs. METHODS: The effect of <2 compared with 2 NRTIs on viral suppression (HIV-1 RNA < 50 copies/mL) at week 24 was studied in salvage patients receiving raltegravir. Intent-to-treat and per-protocol analyses were performed; last observation carried forward imputation was used to deal with missing information. Logistic regressions were weighted to create a pseudopopulation in which the probability of receiving <2 and 2 NRTIs was unrelated to baseline factors predicting treatment response. RESULTS: One-hundred thirty patients were included, of whom 58.5% (n = 76) received <2 NRTIs. NRTIs were often replaced by other drug classes. Patients with 2 NRTIs received less additional drug classes compared with patients with <2 NRTIs [median (IQR): 1 (1-2) compared with 2 (1-2), P Wilcoxon < 0.001]. The activity of non-NRTI treatment components was lower in the 2 NRTIs group compared with the <2 NRTIs group [median (IQR) genotypic sensitivity score: 2 (1.5-2.5) compared with 2.5 (2-3), P Wilcoxon < 0.001]. The administration of <2 NRTIs was associated with a worse viral suppression rate at week 24. The odds ratios were 0.34 (95% confidence interval: 0.13 to 0.89, P = 0.027) and 0.19 (95% confidence interval: 0.05 to 0.79, P = 0.023) when performing the last observation carried forward and the per-protocol approach, respectively. CONCLUSIONS: Our findings showed that partially active or inactive NRTIs contribute to treatment response, and thus the use of 2 NRTIs in salvage regimens that include raltegravir seems warranted.

Prevalence, awareness and treatment of type 2 diabetes mellitus in Switzerland: the CoLaus study.

ABSTRACT: Aims To assess the prevalence, awareness and treatment levels of Type 2 diabetes in a Swiss city. Methods Population-based cross-sectional study of 6181 subjects (3246 women) aged 35-75 years living in Lausanne, Switzerland. Type 2 diabetes was defined as fasting plasma glucose >/= 7 mmol/l and/or oral hypoglycaemic treatment and/or insulin. Results Total prevalence of Type 2 diabetes was 6.3% (95% confidence interval: 5.7-7.0%), higher in men (9.1%) than in women (3.8%, P < 0.001) and increased with age. Two-thirds (65.3%; 60.4-70.0%) of participants with Type 2 diabetes were aware of their status and among those aware 86.0% (81.5-90.3%) were treated. Treatment was more frequent in men (91.3%) than in women (75.9%, P < 0.001). Two-thirds of those treated for Type 2 diabetes were on monotherapy. Biguanides were prescribed in 65.0% of Type 2 diabetes patients and represented 48% of all antidiabetic drugs. Multivariable analysis showed male gender, increasing age, waist or BMI to be positively associated with prevalence of Type 2 diabetes, while leisure-time physical activity and alcohol consumption were negatively associated. Among participants presenting with Type 2 diabetes, increasing age was positively associated with awareness of Type 2 diabetes. Among subjects diagnosed with Type 2 diabetes, male gender and increasing age were positively associated with treatment. Conclusion Prevalence of Type 2 diabetes in Switzerland is estimated to be between 5.7% and 7.0%. Two-thirds of patients with Type 2 diabetes are aware of their status, and over three quarters of those aware are treated.

L'implication des cellules de type cellules souches cancéreuses dans la résistance aux drogues du neuroblastome

Le neuroblastome (NB), tumeur spécifique de l'enfant, se situe au second rang en terme de¦fréquence des tumeurs solides dans la population pédiatrique (1). Il dérive des cellules¦primitives de la crête neurale, une population de cellules embryonnaires dotées d'une¦capacité de différentiation en une panoplie de tissus très variés, dont le système nerveux¦sympathique (2). Cette origine explique la très grande hétérogénéité du NB, tant du point de¦vue biologique que clinique (3). Malgré un traitement intensif et multimodal (chirurgie,¦chimiothérapie à haute dose, greffe de moelle osseuse et immunothérapie), seuls 30 % des¦patients de haut risque (stade IV) survivent sans rechute. La forte résistance du¦neuroblastome de haut grade aux diverses thérapies est une des causes probable du¦pronostic sombre de cette tumeur. Les thérapies actuelles étant insuffisamment efficaces, il¦est primordial de comprendre les mécanismes impliqués dans le processus de résistance¦afin d'élaborer de nouveaux traitements, mieux ciblés, capables de contrer toute résistance¦(4).¦Il a été démontré que certains cancers, tels que les tumeurs du poumon, du sein, de la¦prostate ou du colon, possédaient des cellules souches cancéreuses (CSCs) (5). Ces¦dernières, définies comme étant une petite sous-population de cellules malignes, jouent un¦rôle prépondérant dans l'initiation et la progression tumorale. Elles partagent certaines¦propriétés avec les cellules souches physiologiques, telles que la capacité d'autorenouvellement,¦un potentiel de prolifération indéfini, une dépendance à un¦microenvironnement spécifique, une faculté de pluripotence et une résistance accrue aux¦drogues (6). Ce modèle de CSCs a également été étudié pour le NB (7), permettant ainsi¦d'avancer l'hypothèse selon laquelle cette population de CSCs serait responsable de la¦résistance aux chimiothérapies des cellules tumorales du NB.¦Afin de tenter d'éclaircir le caractère résistant aux drogues des CSCs du NB, nous avons¦sélectionné des sous-populations cellulaires résistantes, en traitant par divers agents¦cytotoxiques (cisplatine, doxorubicine, rapamycine et vincristine) cinq lignées différentes de¦neuroblastes. Dans le but d'établir un potentiel enrichissement en CSCs au sein de ces¦sous-populations par rapport aux populations contrôles non traitées, nous avons testé leurs¦fonctions d'auto-renouvellement et de clonogénicité. Ces propriétés ont été respectivement¦mises en évidence par la capacité des cellules à former des sphères de plusieurs¦générations dans des conditions de culture inhibant l'adhésion cellulaire et par la mesure de¦la croissance cellulaire en milieu semi-solide (soft agar assay). Une analyse d'expression¦génique effectuée préalablement par microarray (Human Genome U133Plus 2.0 Affymetrix¦GeneChip oligonucleotide) dans le laboratoire avait révélé une liste de gènes surexprimés¦dans les CSCs, dont fait partie mdr1 (8). Ce gène code la protéine de transport Pgp (Pglycoprotein),¦impliquée dans le mécanisme de résistance (9,10). Une étude par cytométrie¦en flux de l'expression de MDR1 dans nos diverses populations a également été réalisée¦afin de mettre en évidence une potentielle surexpression de ce gène au sein des cellules¦résistantes aux chimiothérapies.

cGMP-dependent protein kinase type I is implicated in the regulation of the timing and quality of sleep and wakefulness.

Many effects of nitric oxide (NO) are mediated by the activation of guanylyl cyclases and subsequent production of the second messenger cyclic guanosine-3',5'-monophosphate (cGMP). cGMP activates cGMP-dependent protein kinases (PRKGs), which can therefore be considered downstream effectors of NO signaling. Since NO is thought to be involved in the regulation of both sleep and circadian rhythms, we analyzed these two processes in mice deficient for cGMP-dependent protein kinase type I (PRKG1) in the brain. Prkg1 mutant mice showed a strikingly altered distribution of sleep and wakefulness over the 24 hours of a day as well as reductions in rapid-eye-movement sleep (REMS) duration and in non-REM sleep (NREMS) consolidation, and their ability to sustain waking episodes was compromised. Furthermore, they displayed a drastic decrease in electroencephalogram (EEG) power in the delta frequency range (1-4 Hz) under baseline conditions, which could be normalized after sleep deprivation. In line with the re-distribution of sleep and wakefulness, the analysis of wheel-running and drinking activity revealed more rest bouts during the activity phase and a higher percentage of daytime activity in mutant animals. No changes were observed in internal period length and phase-shifting properties of the circadian clock while chi-squared periodogram amplitude was significantly reduced, hinting at a less robust oscillator. These results indicate that PRKG1 might be involved in the stabilization and output strength of the circadian oscillator in mice. Moreover, PRKG1 deficiency results in an aberrant pattern, and consequently a reduced quality, of sleep and wakefulness, possibly due to a decreased wake-promoting output of the circadian system impinging upon sleep.

The ADVANCE trial: clarifying the role of perindopril/indapamide fixed-dose combination in the reduction of cardiovascular and renal events in patients with diabetes mellitus.

Patients with type 2 diabetes mellitus exhibit a marked increase in cardiovascular and renal risk. A number of interventional trials have shown that these patients benefit greatly from aggressive BP lowering, especially when the drug regimen comprises an inhibitor of the renin-angiotensin system. The results of the placebo-controlled ADVANCE (Action in Diabetes and Vascular disease: PreterAx and DiamicroN MR Controlled Evaluation) trial, conducted in patients with type 2 diabetes, are exemplary in this respect. The systematic use of a fixed-dose combination containing the ACE inhibitor perindopril and the diuretic indapamide afforded substantial protection against cardiovascular mortality and myocardial infarction, while providing important renoprotection, reducing the development of micro- and macroalbuminuria, and allowing regression of nephropathy. The beneficial effects were obtained regardless of baseline BP and whether or not the patients were receiving antihypertensive therapy.

Phenotypic and molecular characterization of a novel case of dyssegmental dysplasia, Silverman-Handmaker type.

Dyssegmental dysplasia, Silverman-Handmaker type (DDSH; #MIM 224410) is an autosomal recessive form of lethal dwarfism characterized by a defect in segmentation and fusion of vertebral bodies components ("anisospondyly") and by severe limb shortening. It is caused by mutations in the perlecan gene (HSPG2), but so far, only three molecularly confirmed cases have been reported. We report a novel case of DDSH in a fetus that presented at 15 weeks gestation with encephalocele, severe micromelic dwarfism and narrow thorax. After termination of pregnancy, radiographs showed short ribs, short and bent long bones and anisospondyly of two vertebral bodies. The fetus was homozygous for a previously undescribed null mutation in HSPG2.

PDZ domain-binding motif regulates cardiomyocyte compartment-specific NaV1.5 channel expression and function.

BACKGROUND: Sodium channel NaV1.5 underlies cardiac excitability and conduction. The last 3 residues of NaV1.5 (Ser-Ile-Val) constitute a PDZ domain-binding motif that interacts with PDZ proteins such as syntrophins and SAP97 at different locations within the cardiomyocyte, thus defining distinct pools of NaV1.5 multiprotein complexes. Here, we explored the in vivo and clinical impact of this motif through characterization of mutant mice and genetic screening of patients. METHODS AND RESULTS: To investigate in vivo the regulatory role of this motif, we generated knock-in mice lacking the SIV domain (ΔSIV). ΔSIV mice displayed reduced NaV1.5 expression and sodium current (INa), specifically at the lateral myocyte membrane, whereas NaV1.5 expression and INa at the intercalated disks were unaffected. Optical mapping of ΔSIV hearts revealed that ventricular conduction velocity was preferentially decreased in the transversal direction to myocardial fiber orientation, leading to increased anisotropy of ventricular conduction. Internalization of wild-type and ΔSIV channels was unchanged in HEK293 cells. However, the proteasome inhibitor MG132 rescued ΔSIV INa, suggesting that the SIV motif is important for regulation of NaV1.5 degradation. A missense mutation within the SIV motif (p.V2016M) was identified in a patient with Brugada syndrome. The mutation decreased NaV1.5 cell surface expression and INa when expressed in HEK293 cells. CONCLUSIONS: Our results demonstrate the in vivo significance of the PDZ domain-binding motif in the correct expression of NaV1.5 at the lateral cardiomyocyte membrane and underline the functional role of lateral NaV1.5 in ventricular conduction. Furthermore, we reveal a clinical relevance of the SIV motif in cardiac disease.

ALK inhibitors in the treatment of advanced NSCLC.

Pharmacologic agents that target protein products of oncogenes in tumors are playing an increasing clinical role in the treatment of cancer. Currently, the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) represent the standard of care for patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) harboring activating EGFR mutations. Subsequently other genetic abnormalities with "driver" characteristics - implying transforming and tumor maintenance capabilities have been extensively reported in several small distinct subsets of NSCLC. Among these rare genetic changes, anaplastic lymphoma kinase (ALK) gene rearrangements, most often consisting in a chromosome 2 inversion leading to a fusion with the echinoderm microtubule-associated protein like 4 (EML4) gene, results in the abnormal expression and activation of this tyrosine kinase in the cytoplasm of cancer cells. This rearrangement occurs in 2-5% of NSCLC, predominantly in young (50 years or younger), never- or former-smokers with adenocarcinoma. This aberration most commonly occurs a independently of EGFR and KRAS gene mutations. A fluorescent in situ hybridization assay was approved by the US Food and Drug Administration (FDA) as the standard method for the detection of ALK gene rearrangement in clinical practice and is considered the gold standard. Crizotinib, a first-in-class dual ALK and c-MET inhibitor, has been shown to be particularly effective against ALK positive NSCLC, showing dramatic and prolonged responses with low toxicity, predominantly restricted to the gastro-intestinal and visual systems, and generally self-limiting or easily managed. However, resistance to crizotinib inevitably emerges. The molecular mechanisms of resistance are currently under investigation, as are therapeutic approaches including crizotinib-based combination therapy and novel agents such as Hsp90 inhibitors. This review aims to present the current knowledge on this fusion gene, the clinic-pathological profile of ALK rearranged NSCLC, and to review the existing literature on ALK inhibitors, focusing on their role in the treatment of NSCLC.

French Swiss physicians' attitude toward palliative sedation: Influence of prognosis and type of suffering.

OBJECTIVE: Palliative sedation is a last resort medical act aimed at relieving intolerable suffering induced by intractable symptoms in patients at the end-of-life. This act is generally accepted as being medically indicated under certain circumstances. A controversy remains in the literature as to its ethical validity. There is a certain vagueness in the literature regarding the legitimacy of palliative sedation in cases of non-physical refractory symptoms, especially "existential suffering." This pilot study aims to measure the influence of two independent variables (short/long prognosis and physical/existential suffering) on the physicians' attitudes toward palliative sedation (dependent variable). METHODS: We used a 2 × 2 experimental design as described by Blondeau et al. Four clinical vignettes were developed (vignette 1: short prognosis/existential suffering; vignette 2: long prognosis/existential suffering; vignette 3: short prognosis/physical suffering; vignette 4: long prognosis/physical suffering). Each vignette presented a terminally ill patient with a summary description of his physical and psychological condition, medication, and family situation. The respondents' attitude towards sedation was assessed with a six-point Likert scale. A total of 240 vignettes were sent to selected Swiss physicians. RESULTS: 74 vignettes were completed (36%). The means scores for attitudes were 2.62 ± 2.06 (v1), 1.88 ± 1.54 (v2), 4.54 ± 1.67 (v3), and 4.75 ± 1.71 (v4). General linear model analyses indicated that only the type of suffering had a significant impact on the attitude towards sedation (F = 33.92, df = 1, p = 0.000). Significance of the results: The French Swiss physicians' attitude toward palliative sedation is more favorable in case of physical suffering than in existential suffering. These results are in line with those found in the study of Blondeau et al. with Canadian physicians and will be discussed in light of the arguments given by physicians to explain their decisions.

The prolyl-aminodipeptidases and their inhibitors as therapeutic targets for fibrogenic disorders

Many biologically active peptides are protected from general proteolytic degradation by evolutionary conserved prolines (Pro), due to conformational constraints imposed by the Pro residue. Thus the biological importance of prolyl-specific peptidases points to a high potential for drug discovery for this family of enzymes. Panels of inhibitors have been synthesized and their effects, determined in biological models, suggest the inhibition of families of enzymes with similar activities. Prolyl-specific aminodipeptidases include dipeptidyl-aminodipeptidase IV (DPP IV)/CD26, DPP8, DPP9 and fibroblast activation protease-alpha (FAP-alpha)/seprase, able to release X-Pro dipeptides from the N-terminus of peptides. DPP IV inhibitors are in clinical use for type 2 diabetes. In this review, the expression and the potential functions of prolyl-aminodipeptidases are reviewed in diseases, and the inhibitors developed for these enzymes are discussed, with a specific focus on inhibitors able to discriminate between DPP IV and fibroblast activation protease-alpha (FAPalpha)/seprase as potential leads for the treatment of fibrogenic diseases.

Stratégies thérapeutiques en présence d'un diabète de type 2 [Therapeutic strategies in type 2 diabetes]

UKPDS and DCCT studies have demonstrated the critical role of tight glycaemic control to reduce the micro- and macro-vascular damage linked to diabetes. Unfortunately, the insulin requirement of type 2 diabetic patients remains elevated since 5 to 7% of these patients will required, yearly, a change from oral antidiabetic drug to insulin treatment to maintain a good glycaemic control. This manuscript is intended to review the currently available oral antidiabetic drugs, their benefits as well as potential arms and to propose a simplified therapeutic strategy in presence of type 2 diabetes.