Gene Expression Profiling in Cells with Enhanced γ-Secretase Activity

BACKGROUND: Processing by gamma-secretase of many type-I membrane protein substrates triggers signaling cascades by releasing intracellular domains (ICDs) that, following nuclear translocation, modulate the transcription of different genes regulating a diverse array of cellular and biological processes. Because the list of gamma-secretase substrates is growing quickly and this enzyme is a cancer and Alzheimer's disease therapeutic target, the mapping of gamma-secretase activity susceptible gene transcription is important for sharpening our view of specific affected genes, molecular functions and biological pathways. METHODOLOGY/PRINCIPAL FINDINGS: To identify genes and molecular functions transcriptionally affected by gamma-secretase activity, the cellular transcriptomes of Chinese hamster ovary (CHO) cells with enhanced and inhibited gamma-secretase activity were analyzed and compared by cDNA microarray. The functional clustering by FatiGO of the 1,981 identified genes revealed over- and under-represented groups with multiple activities and functions. Single genes with the most pronounced transcriptional susceptibility to gamma-secretase activity were evaluated by real-time PCR. Among the 21 validated genes, the strikingly decreased transcription of PTPRG and AMN1 and increased transcription of UPP1 potentially support data on cell cycle disturbances relevant to cancer, stem cell and neurodegenerative diseases' research. The mapping of interactions of proteins encoded by the validated genes exclusively relied on evidence-based data and revealed broad effects on Wnt pathway members, including WNT3A and DVL3. Intriguingly, the transcription of TERA, a gene of unknown function, is affected by gamma-secretase activity and was significantly altered in the analyzed human Alzheimer's disease brain cortices. CONCLUSIONS/SIGNIFICANCE: Investigating the effects of gamma-secretase activity on gene transcription has revealed several affected clusters of molecular functions and, more specifically, 21 genes that hold significant potential for a better understanding of the biology of gamma-secretase and its roles in cancer and Alzheimer's disease pathology

Le Commerce contrôlé des produits de santé en pharmacie dans le cadre d'une gérance d'officine

TOURS-BU Sciences Pharmacie (372612104) / SudocSudocFranceF

NGAL is a Novel Target in Hypertension by Modulating the NCC-Mediated Renal Na Balance

International audienceBACKGROUND: The expression of NGAL/lcn2 (neutrophil gelatinase-associated lipocalin) is directly modulated by mineralocorticoid receptor activation but its role in blood pressure control is unclear. METHODS: a potential relationship between NGAL plasma levels, systolic blood pressure and urinary Na excretion was assessed in the STANISLAS cohort. The specific role of NGAL/lcn2 in salt-sensitive hypertension was studied using lcn2-knockout mice (lcn2 KO) fed with low-Na diet (0Na). RESULTS: we show that NGAL plasma levels positively correlate with systolic blood pressure, whereas they negatively correlate with urinary Na excretion in subjects of the STANISLAS cohort. Prolonged feeding of lcn2 KO mice with a 0Na diet induced lower systolic blood pressure than that of the control group (wildtype), suggesting a role for NGAL/lcn2 in Na-balance homeostasis. Short-term or prolonged 0Na increased Na-Cl cotransporter (NCC) phosphorylation in the cortex of wildtype mice, which was prevented in lcn2 KO mice. Recombinant mouse lcn2 injections in lcn2 KO mice induced NCC phosphorylation in the kidney cortex, associated with decreased urinary Na excretion. Ex vivo experiments using kidney slices from lcn2 KO mice showed increased NCC phosphorylation by recombinant murine lcn2. In addition, recombinant murine lcn2 induced activation of CamK2β (calcium/calmodulin-dependent protein kinase II β subunit) phosphorylation in lcn2 KO mice and in kidney slices, providing an underlying mechanism involved in lcn2-induced NCC phosphorylation. Indeed, the inhibition of CamK2β prevented NCC phosphorylation induced by recombinant lcn2 in kidney slices. CONCLUSIONS: we highlight a novel role of NGAL/lcn2 as a modulator of the activity of the renal sodium transporter NCC affecting salt-sensitive blood pressur

Diversity and Distribution of Characeae in the Maghreb (Algeria, Morocco, Tunisia)

International audienceCharaceae are macroscopic green algae present in the Maghreb (Morocco, Algeria, Tunisia) that are known since the 19th century works of Desfontaines (1800) and Braun (1868). Feldmann (1946) published the first regional synthesis, and this study provides a new Maghreb-wide synthesis of all collections made since 1784 (570 observations distributed over 464 sites). Each of the 31 reported species is described in detail with its diagnostic features, ecology and distribution in the three Maghrebian countries. Distribution maps distinguish between the three collection periods: 1780–1939, 1940–1979, and 1980–2016. An illustrated key is provided to help botanists working in the Maghreb to identify the taxa. From a biogeographical perspective, the Characean flora of the Maghreb is dominated by elements originating from northern (European) countries (61.3%) that include regionally very rare species such as Chara strigosa and C. tomentosa. The Mediterranean-Atlantic element is also well represented (32.3%), with some Mediterranean endemics (Chara imperfecta, C. oedophylla, C. vulgaris var. gymnophylla). Finally, two taxa that have an affinity for tropical conditions (Chara zeylanica and Lamprothamnium succinctum) extend to the southern Sahara. In North Africa, 14 species (7 Chara, 2 Lamprothamnium, 4 Nitella and 1 Sphaerochara) are threatened and raise issues about their conservation; three of these are particularly endangered: Chara imperfecta, C. oedophylla and Lamprothamnium papulosum

Intermittent two-drug antiretroviral therapies maintain long-term viral suppression in real life in highly experienced HIV-infected patients

International audienceObjectives: To assess in real life whether two-drug regimens (2-DRs) given 4-5 days a week in virally suppressed patients can maintain viral suppression over 48 and 96 weeks.Methods: This observational single-centre study enrolled all patients who initiated an intermittent 2-DR between 01/01/2016 and 30/06/2019. The primary outcome was the rate of virological failure (VF), defined as confirmed plasma viral load (pVL) ≥50 copies/mL or single pVL ≥50 copies/mL followed by ART change at week 48 (W48) and W96. Secondary outcomes were the 2-DR intermittent strategy success rate (pVL <50 copies/mL with no ART change), change in CD4 count, CD4/CD8 ratio and rate of residual viraemia.Results: Eighty-five patients were included; 67/85 (79%) were men, median age = 57 years (IQR = 50-63), CD4 nadir = 233 cells/mm3 (110-327), ART duration = 21 years (13-24), duration of virological suppression = 6.5 years (3.7-10.8) and CD4 count = 658 cells/mm3 (519-867). Intermittent 2-DRs consisted of integrase strand transfer inhibitor (INSTI)/NNRTI (58%), INSTI/NRTI (13%), two NRTIs (11%), PI/NRTI (7%) and other combinations (11%). The median follow-up was 90 weeks (IQR = 64-111). Overall, four VFs occurred, leading to a virological success rate of 98.8% (95% CI = 93.6-100) at W48 and 95.3% (95% CI = 88.4-98.7) at W96. Resuming the same 2-DR 7 days a week led to viral resuppression in three patients, whereas the M184V mutation emerged in one patient, leading to ART modification. There was no significant change in the CD4 count or residual viraemia rate, but a small increase in the CD4/CD8 ratio (P = 0.009) occurred over the study period.Conclusions: This observational study shows the potential for intermittent 2-DRs to maintain a high virological success rate, which should be assessed in larger prospective randomized studies

Phase II trial of cetuximab in combination with fluorouracil, leucovorin, and oxaliplatin in the first-line treatment of metastatic colorectal cancer.

This phase II study investigated the efficacy and safety of cetuximab combined with standard oxaliplatin-based chemotherapy (infusional fluorouracil, leucovorin, and oxaliplatin [FOLFOX-4]) in the first-line treatment of epidermal growth factor receptor-expressing metastatic colorectal cancer (mCRC).Clinical Trial, Phase IIJournal ArticleMulticenter Studyinfo:eu-repo/semantics/publishe

Serum Detection of Nonadherence to Adjuvant Tamoxifen and Breast Cancer Recurrence Risk

International audienc

Prognosis value of a genetic score based on germline genetic variants in a prospective cohort of early triple negative breast cancer patients

International audienceBackground: Triple-negative breast cancers (TNBC) are a heterogeneous group of tumors with poor outcome. In this study, the association between germline genetic variants and invasive disease-free survival (iDFS) was analyzed in TNBC patients. Methods: A genome wide-association study (GWAS) aimed to identify variants (single nucleotide polymorphisms – SNPs) associated with prognosis in 1121 patients with TNBC in the SIGNAL prospective cohort. Associations between gene variants and iDFS were assessed in univariate Cox regression models. Variants were combined in a score to identify risk categories. A prognostic model based on breast cancer stage and genetic variants was estimated using a multivariate Cox regression. Interaction between stage and genetic score was tested. Discrimination of the model was assessed by the Harrell’s C statistic and internal validity by bootstrap method. Results: The characteristics of the 1121 patients were representative of a population with early TNBC. Four SNPs on chromosomes 9 and 2 were found significantly associated to iDFS in univariate Cox models. Homozygous status for the most frequent allele was associated with poorer iDFS for two SNPs and this status was present in 50% and 57% of the population. For the two other SNPs, the most frequent allele was associated with more favorable iDFS. Three prognostic categories were derived from the genetic score. The following table presents the results from the multivariate Cox model including genetic score and disease stage. Clinical trial information: RECF1098. Conclusions: In a prospective cohort of 1121 patients with early TNBC, 4 genetic variants (SNPs) were associated with iDFS. A score involving SNPs provided similar prognostic indications as breast cancer stages. A search assessing the function and the role of the involved genes is ongoing

Intra-database validation of case-identifying algorithms using reconstituted electronic health records from healthcare claims data

BACKGROUND: Diagnosis performances of case-identifying algorithms developed in healthcare database are usually assessed by comparing identified cases with an external data source. When this is not feasible, intra-database validation can present an appropriate alternative. OBJECTIVES: To illustrate through two practical examples how to perform intra-database validations of case-identifying algorithms using reconstituted Electronic Health Records (rEHRs). METHODS: Patients with 1) multiple sclerosis (MS) relapses and 2) metastatic castration-resistant prostate cancer (mCRPC) were identified in the French nationwide healthcare database (SNDS) using two case-identifying algorithms. A validation study was then conducted to estimate diagnostic performances of these algorithms through the calculation of their positive predictive value (PPV) and negative predictive value (NPV). To that end, anonymized rEHRs were generated based on the overall information captured in the SNDS over time (e.g. procedure, hospital stays, drug dispensing, medical visits) for a random selection of patients identified as cases or non-cases according to the predefined algorithms. For each disease, an independent validation committee reviewed the rEHRs of 100 cases and 100 non-cases in order to adjudicate on the status of the selected patients (true case/ true non-case), blinded with respect to the result of the corresponding algorithm. RESULTS: Algorithm for relapses identification in MS showed a 95% PPV and 100% NPV. Algorithm for mCRPC identification showed a 97% PPV and 99% NPV. CONCLUSION: The use of rEHRs to conduct an intra-database validation appears to be a valuable tool to estimate the performances of a case-identifying algorithm and assess its validity, in the absence of alternative