Expression in Escherichia coli, purification, refolding and antifungal activity of an osmotin from Solanum nigrum

This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

LGR5 regulates pro-survival MEK/ERK and proliferative Wnt/β-catenin signalling in neuroblastoma.

LGR5 is a marker of normal and cancer stem cells in various tissues where it functions as a receptor for R-spondins and increases canonical Wnt signalling amplitude. Here we report that LGR5 is also highly expressed in a subset of high grade neuroblastomas. Neuroblastoma is a clinically heterogenous paediatric cancer comprising a high proportion of poor prognosis cases (~40%) which are frequently lethal. Unlike many cancers, Wnt pathway mutations are not apparent in neuroblastoma, although previous microarray analyses have implicated deregulated Wnt signalling in high-risk neuroblastoma. We demonstrate that LGR5 facilitates high Wnt signalling in neuroblastoma cell lines treated with Wnt3a and R-spondins, with SK-N-BE(2)-C, SK-N-NAS and SH-SY5Y cell-lines all displaying strong Wnt induction. These lines represent MYCN-amplified, NRAS and ALK mutant neuroblastoma subtypes respectively. Wnt3a/R-Spondin treatment also promoted nuclear translocation of β-catenin, increased proliferation and activation of Wnt target genes. Strikingly, short-interfering RNA mediated knockdown of LGR5 induces dramatic Wnt-independent apoptosis in all three cell-lines, accompanied by greatly diminished phosphorylation of mitogen/extracellular signal-regulated kinases (MEK1/2) and extracellular signal-regulated kinases (ERK1/2), and an increase of BimEL, an apoptosis facilitator downstream of ERK. Akt signalling is also decreased by a Rictor dependent, PDK1-independent mechanism. LGR5 expression is cell cycle regulated and LGR5 depletion triggers G1 cell-cycle arrest, increased p27 and decreased phosphorylated retinoblastoma protein. Our study therefore characterises new cancer-associated pathways regulated by LGR5, and suggest that targeting of LGR5 may be of therapeutic benefit for neuroblastomas with diverse etiologies, as well as other cancers expressing high LGR5

Predictors of response to TNF blockers in patients with polyarticular psoriatic arthritis

Psoriatic arthritis (PsA) is a chronic inflammatory rheumatic disease with a broad clinical spectrum. PsA can affect the axialskeleton, peripheral joints, entheses, synovial sheaths of tendons, skin, nails and extra-articular organs. Tumour necrosis factor alpha blockers (TNF blockers) were a breakthrough development in the treatment of PsA. Identifying predictors of response to biological therapiesin patients with PsA is of utmost importance, especially in view of the costs and potential side effects of these agents. The aims of the present study were to determine baseline predictive factors of response to biological therapies, at 3 and 6 months, in PsA patients with polyarticular involvement (with or without axial involvement). Data were collected from the RheumaticDiseases Portuguese Register(Reuma.pt). Eligible patients had to be anti-TNF-naive at baseline and to have at least 3 months of follow-up after the beginning of TNF blocker therapy. Only patients with information on at least one of the response measures (at 3 or 6 months of follow-up) were included in the analysis. Univariable logistic regression analysis of potential baseline predictors of European League Against Rheu-matism (EULAR) good clinical response, EULAR good/ /moderate response, 28-joint Disease Activity Score with three variables including the erythrocyte sedimentation rate (DAS28-3V-ESR) remission and Health Assessment Questionnaire (HAQ) response were performed. Multivariable logistic regression using a forward selection procedure was used until the best-fit model was obtained, taking confounding effects into account. A total of 180 patients were eligible for the study (mean age 52 years, 54% women). In multivariable analysis at 3 months, females were less likely to attain a good EULAR response [OR=0.082 (95% CI=0.024, 0.278)], a DAS28-3V-ESR remission [OR=0.083 (95% CI=0.017, 0.416)], a moderate or good EULAR response [OR=0.091 (95% CI=0.011, 0.091)] and a HAQ response [OR=0.074 (95% CI=0.009, 0.608)]. At 6 months, female gender was also less likely to achieve a good EULAR response [OR=0.060 (95% CI=0.011, 0.325)], DAS28-3V-ESR remission [OR=0.060 (95% CI=0.012, 0.297)], and a HAQ response [OR=0.138 (95% CI= 0.029, 0.654)]. In this study we found that gender was the most consistent predictor of response to TNF blocker therapy in patients with polyarticular PsA, with females having a lower probability ofresponse compared to males. These findings suggest that gender-related biochemical, hormonal and psychological factors could play an importantrole in the response to TNF blockertherapy in PsA

The incidence of liver injury in Uyghur patients treated for TB in Xinjiang Uyghur autonomous region, China, and its association with hepatic enzyme polymorphisms nat2, cyp2e1, gstm1 and gstt1.

BACKGROUND AND OBJECTIVE: Of three first-line anti-tuberculosis (anti-TB) drugs, isoniazid is most commonly associated with hepatotoxicity. Differences in INH-induced toxicity have been attributed to genetic variability at several loci, NAT2, CYP2E1, GSTM1and GSTT1, that code for drug-metabolizing enzymes. This study evaluated whether the polymorphisms in these enzymes were associated with an increased risk of anti-TB drug-induced hepatitis in patients and could potentially be used to identify patients at risk of liver injury. METHODS AND DESIGN: In a cross-sectional study, 2244 tuberculosis patients were assessed two months after the start of treatment. Anti-TB drug-induced liver injury (ATLI) was defined as an ALT, AST or bilirubin value more than twice the upper limit of normal. NAT2, CYP2E1, GSTM1 and GSTT1 genotypes were determined using the PCR/ligase detection reaction assays. RESULTS: 2244 patients were evaluated, there were 89 cases of ATLI, a prevalence of 4% 9 patients (0.4%) had ALT levels more than 5 times the upper limit of normal. The prevalence of ATLI was greater among men than women, and there was a weak association with NAT2*5 genotypes, with ATLI more common among patients with the NAT2*5*CT genotype. The sensitivity of the CT genotype for identifying patients with ATLI was 42% and the positive predictive value 5.9%. CT ATLI was more common among slow acetylators (prevalence ratio 2.0 (95% CI 0.95,4.20) )compared to rapid acetylators. There was no evidence that ATLI was associated with CYP2E1 RsaIc1/c1genotype, CYP2E1 RsaIc1/c2 or c2/c2 genotypes, or GSTM1/GSTT1 null genotypes. CONCLUSIONS: In Xinjiang Uyghur TB patients, liver injury was associated with the genetic variant NAT2*5, however the genetic markers studied are unlikely to be useful for screening patients due to the low sensitivity and low positive predictive values for identifying persons at risk of liver injury

Synchronization modulation increases transepithelial potentials in MDCK monolayers through Na/K pumps

Peer reviewedPublisher PD

Graph-based analysis of the metabolic exchanges between two co-resident intracellular symbionts, baumannia cicadellinicola and sulcia muelleri with their insect host, homalodisca coagulata

International audienceEndosymbiotic bacteria from different species can live inside cells of the same eukaryotic organism. Metabolic exchanges occur between host and bacteria but also between different endocytobionts. Since a complete genome annotation is available for both, we built the metabolic network of two endosymbiotic bacteria, Sulcia muelleri and Baumannia cicadellinicola, that live inside specific cells of the sharpshooter Homalodisca coagulata and studied the metabolic exchanges involving transfers of carbon atoms between the three. We automatically determined the set of metabolites potentially exogenously acquired (seeds) for both metabolic networks. We show that the number of seeds needed by both bacteria in the carbon metabolism is extremely reduced. Moreover, only three seeds are common to both metabolic networks, indicating that the complementarity of the two metabolisms is not only manifested in the metabolic capabilities of each bacterium, but also by their different use of the same environment. Furthermore, our results show that the carbon metabolism of S. muelleri may be completely independent of the metabolic network of B. cicadellinicola. On the contrary, the carbon metabolism of the latter appears dependent on the metabolism of S. muelleri, at least for two essential amino acids, threonine and lysine. Next, in order to define which subsets of seeds (precursor sets) are sufficient to produce the metabolites involved in a symbiotic function, we used a graph-based method, PITUFO, that we recently developed. Our results highly refine our knowledge about the complementarity between the metabolisms of the two bacteria and their host. We thus indicate seeds that appear obligatory in the synthesis of metabolites are involved in the symbiotic function. Our results suggest both B. cicadellinicola and S. muelleri may be completely independent of the metabolites provided by the co-resident endocytobiont to produce the carbon backbone of the metabolites provided to the symbiotic system (., thr and lys are only exploited by B. cicadellinicola to produce its proteins)