Genome-scale metabolic model of the human pathogen Candida albicans: a promising platform for drug target prediction

Candida albicans is one of the most impactful fungal pathogens and the most common cause of invasive candidiasis, which is associated with very high mortality rates. With the rise in the frequency of multidrug-resistant clinical isolates, the identification of new drug targets and new drugs is crucial in overcoming the increase in therapeutic failure. In this study, the first validated genome-scale metabolic model for Candida albicans, iRV781, is presented. The model consists of 1221 reactions, 926 metabolites, 781 genes, and four compartments. This model was reconstructed using the open-source software tool merlin 4.0.2. It is provided in the well-established systems biology markup language (SBML) format, thus, being usable in most metabolic engineering platforms, such as OptFlux or COBRA. The model was validated, proving accurate when predicting the capability of utilizing different carbon and nitrogen sources when compared to experimental data. Finally, this genome-scale metabolic reconstruction was tested as a platform for the identification of drug targets, through the comparison between known drug targets and the prediction of gene essentiality in conditions mimicking the human host. Altogether, this model provides a promising platform for global elucidation of the metabolic potential of C. albicans, possibly guiding the identification of new drug targets to tackle human candidiasis.“Fundação para a Ciência e a Tecnologia” (FCT) [Contract PTDC /BII-BIO/28216/2017] and by Programa Operacional Regional de Lisboa 2020 [LISBOA-01-0145-FEDER-022231], through the Biodata.pt Research Infrastructure. Funding received by iBB-Institute for Bioengineering and Biosciences from FCT [Contract UIDB/04565/2020]info:eu-repo/semantics/publishedVersio

Genome-scale metabolic model of the human pathogen C. albicans: aiming the identification of promising new drug targets

Candida albicans is the most common cause of invasive candidiasis, partly due to its ability to acquire drug resistance. With the rise in frequency of multidrug resistant clinical isolates, therapeutic options are running low. The identification of new drug targets and new drugs is crucial to overcome the increase in therapeutic failure. Currently, genome-scale metabolic models can be considered established tools for drug targeting. In this study, we propose the first genome-scale metabolic model for Candida albicans, iRV1930. The model consists of 1556 reactions, 1344 metabolites, 1053 genes, and 5 compartments. This model, currently under validation, proved accurate when predicting the capability of utilizing different carbon and nitrogen sources when compared to experimental data. This model was reconstructed using open source software tool, merlin 3.9.6, and is provided in the well-established systems biology markup language (SBML) format, thus, it can be used in most metabolic engineering platforms, such as OptFlux or Cobra. Altogether, this model provides a promising platform for global elucidation of the metabolism of C. albicans, currently being used to guide the identification of new drug targets to tackle human candidiasis.info:eu-repo/semantics/publishedVersio

Is there Enough Justification for Questioning Body Mass Index (BMI) as Exclusion Criteria of Reduction Mammoplasty in the Surgical Treatment of Symptomatic Macromastia?

Background: Despite the fact that reduction mammaplasty is an effective and efficient treatment to symptomatic macromastia, frequently, women demanding this treatment are accepted or not depending on body mass index criteria. The aim of this work was to compare changes of quality of life on obese and no-obese women who undergoing breast reduction mammaplasty. Methods: A prospective study was performed on 56 consecutive women undergoing bilateral reduction mammaplasty for symptomatic macromastia, 21 of them had a BMI lower than 30 (No-obese group) and 35 with 30 or higher BMI (Obese group). Short Form SF-36 quality of life questionnaires were answered at interviews a week before the surgery and six months after. To evaluate the change of quality of life we used “effect size”. Results: Preoperative SF36 scores did not make differences between both groups. Six months after surgery only postoperative physical score of no-obese patients was significantly higher than obese one (52.11 vs 48.47, p>0.05). Both groups increased clearly their quality of life showing an increment of all SF36 domains with an effect size ranged from 0.53 to 2.07. More than seventy percent of obese women improved their scores exceeding means of preoperative scores. Conclusion: According to our results and the fact that the main goal of the breast reduction is ameliorate the quality of life there is no justification for exclusion obese patients with BMI >30 who suffer from symptomatic macromastia from reduction mammaplasty

High-throughput screen with the l,d-transpeptidase LdtMt2 of Mycobacterium tuberculosis reveals novel classes of covalently reacting inhibitors

Disruption of bacterial cell wall biosynthesis in Mycobacterium tuberculosis is a promising target for treating tuberculosis. The L,D-transpeptidase LdtMt2, which is responsible for the formation of 3 → 3 cross-links in the cell wall peptidoglycan, has been identified as essential for M. tuberculosis virulence. We optimised a high-throughput assay for LdtMt2, and screened a targeted library of ∼10 000 electrophilic compounds. Potent inhibitor classes were identified, including established (e.g., β-lactams) and unexplored covalently reacting electrophilic groups (e.g., cyanamides). Protein-observed mass spectrometric studies reveal most classes to react covalently and irreversibly with the LdtMt2 catalytic cysteine (Cys354). Crystallographic analyses of seven representative inhibitors reveal induced fit involving a loop enclosing the LdtMt2 active site. Several of the identified compounds have a bactericidal effect on M. tuberculosis within macrophages, one with an MIC50 value of ∼1 μM. The results provide leads for the development of new covalently reaction inhibitors of LdtMt2 and other nucleophilic cysteine enzymes

Mandibular torus as a new index of success for mandibular advancement devices

Background: In obstructive sleep apnoea (OSA), treatment with mandibular advancement devices (MADs) reduces patients' Apnoea-Hypopnoea index (AHI) scores and improves their sleepiness and quality of life. MADs are non-invasive alternatives for patients who cannot tolerate traditional continuous positive airway pressure (CPAP) therapy. The variability of responses to these devices makes it necessary to search for predictors of success. The aim of our study was to evaluate the presence of mandibular torus as a predictor of MAD efficacy in OSA and to identify other potential cephalometric factors that could influence the response to treatment. Methods: This was a retrospective cohort study. The study included 103 patients diagnosed of OSA who met the criteria for initiation of treatment with MAD. Structural variables were collected (cephalometric and the presence or absence of mandibular torus). Statistical analysis was performed to evaluate the existence of predictive factors for the efficacy of MADs. Results: A total of 103 patients who were consecutively referred for treatment with MAD were included (89.3% men); the mean age of the participants was 46.3 years, and the mean AHI before MAD was 31.4 (SD 16.2) and post- MAD 11.3 (SD 9.2). Thirty-three percent of patients had mandibular torus. Torus was associated with a better response (odds ratio (OR) = 2.854 (p = 0.035)) after adjustment for sex, age, body mass index (BMI; kg/m2), the angle formed by the occlusal plane to the sella?nasion plane (OCC plane to SN), overinjection, and smoking. No cephalometric predictors of efficacy were found that were predictive of MAD treatment success. Conclusions: The presence of a mandibular torus practically triples the probability of MAD success. This is the simplest examination with the greatest benefits in terms of the efficacy of MAD treatment for OSA

Tetrahydropyrazolo[1,5-a]Pyrimidine-3-Carboxamide and N-Benzyl-6′,7′-Dihydrospiro[Piperidine-4,4′-Thieno[3,2-c]Pyran] analogues with bactericidal efficacy against Mycobacterium tuberculosis targeting MmpL3

Mycobacterium tuberculosis is a major human pathogen and the causative agent for the pulmonary disease, tuberculosis (TB). Current treatment programs to combat TB are under threat due to the emergence of multi-drug and extensively-drug resistant TB. As part of our efforts towards the discovery of new anti-tubercular leads, a number of potent tetrahydropyrazolo[1,5-a]pyrimidine-3-ca​rboxamide(THPP) and N-benzyl-6′,7′-dihydrospiro[piperidine-4,​4′-thieno[3,2-c]pyran](Spiro) analogues were recently identified against Mycobacterium tuberculosis and Mycobacterium bovis BCG through a high-throughput whole-cell screening campaign. Herein, we describe the attractive in vitro and in vivo anti-tubercular profiles of both lead series. The generation of M. tuberculosis spontaneous mutants and subsequent whole genome sequencing of several resistant mutants identified single mutations in the essential mmpL3 gene. This ‘genetic phenotype’ was further confirmed by a ‘chemical phenotype’, whereby M. bovis BCG treated with both the THPP and Spiro series resulted in the accumulation of trehalose monomycolate. In vivo efficacy evaluation of two optimized THPP and Spiro leads showed how the compounds were able to reduce >2 logs bacterial cfu counts in the lungs of infected mice

Kras oncogene ablation prevents resistance in advanced lung adenocarcinomas

KRASG12C inhibitors have revolutionized the clinical management of patients with KRASG12C-mutant lung adenocarcinoma. However, patient exposure to these inhibitors leads to the rapid onset of resistance. In this study, we have used genetically engineered mice to compare the therapeutic efficacy and the emergence of tumor resistance between genetic ablation of mutant Kras expression and pharmacological inhibition of oncogenic KRAS activity. Whereas Kras ablation induces massive tumor regression and prevents the appearance of resistant cells in vivo, treatment of KrasG12C/Trp53-driven lung adenocarcinomas with sotorasib, a selective KRASG12C inhibitor, caused a limited antitumor response similar to that observed in the clinic, including the rapid onset of resistance. Unlike in human tumors, we did not observe mutations in components of the RAS-signaling pathways. Instead, sotorasib-resistant tumors displayed amplification of the mutant Kras allele and activation of xenobiotic metabolism pathways, suggesting that reduction of the on-target activity of KRASG12C inhibitors is the main mechanism responsible for the onset of resistance. In sum, our results suggest that resistance to KRAS inhibitors could be prevented by achieving a more robust inhibition of KRAS signaling mimicking the results obtained upon Kras ablation.This work was supported by grants from the European Research Council (ERC-GA 695566, THERACAN); the Agencia Estatal de Investigación, Ministerio de Ciencia e Innovación (MCIN/AEI/10.13039/501100011033) (grant RTC2017-6576-1), cofunded by ERDF “A way of making Europe”; the Autonomous Community of Madrid (B2017/BMD-3884 iLung-CM), cofunded by FSE and ERDF “A way of making Europe”; the CRIS Cancer Foundation, the Scientific Foundation of the Spanish Association Against Cancer (GC166173694BARB); an ERA PerMed grant, funded by the Instituto de Salud Carlos III (AC20/00114), the Scientific Foundation of the Spanish Association Against Cancer (PERME20707BARB) and the European Union’s Horizon 2020 program (779282) to MB; and the Agencia Estatal de Investigación, Ministerio de Ciencia e Innovación (grant RTI2018-094664-B-I00), cofunded by ERDF “A way of making Europe” to MM and MB. Additional funding included grants from the Spanish National Research and Development Plan, Instituto de Salud Carlos III, ERDF “A way of making Europe” (PI20/01837 and DTS19/00111); the Scientific Foundation of the Spanish Association Against Cancer (LABAE20049RODR) to SRP; the Instituto de Salud Carlos III (PI19/00514), cofunded by ERDF “A way of making Europe” to CG; the Agencia Estatal de Investigación, Ministerio de Ciencia e Innovación (grant PID2020-116705RB-I00); and the Scientific Foundation of the Spanish Association Against Cancer (LABAE211678DROS) to MD. MB is a recipient of an endowed chair from the AXA Research Fund. M Salmón was supported by a predoctoral contract “Severo Ochoa” (BES-2016-079096) from the Agencia Estatal de Investigación, Ministerio de Ciencia e Innovación. OB is a recipient of a fellowship from the Formación de Personal Investigador (FPI) program of the Agencia Estatal de Investigación, Ministerio de Ciencia e Innovación. FFG was supported by a Formación de Profesorado Universitario (FPU) fellowship from the Ministerio de Universidades

External validity of clinical trials with diverse trastuzumab-based chemotherapy regimens in advanced gastroesophageal adenocarcinoma: data from the AGAMENON-SEOM registry

Background: Trastuzumab combined with cisplatin and fluoropyrimidines, either capecitabine or 5-fluorouracile (XP/FP), is the standard first-line treatment for advanced, HER2-positive, gastric cancer patients based on the ToGA trial. Despite the lack of phase III trials, many clinicians administer trastuzumab with alternative regimens. One meta-analysis suggests that substituting cisplatin for oxaliplatin might lead to greater efficacy and less toxicity. Methods: 594 patients with HER2-positive gastroesophageal adenocarcinoma were recruited from the AGAMENON-SEOM registry. The objective was to evaluate the external validity of clinical trials with chemotherapy and trastuzumab. Results: The regimens used in at least 5% of the patients were XP (27%), oxaliplatin and capecitabine (CAPOX) (26%), oxaliplatin and 5-fluorouracil (FOLFOX) (14%), FP (14%), triplet with anthracycline/docetaxel (7%), and carboplatin-FU (5%). Median exposure to trastuzumab was longer with FOLFOX (11.4 months, 95% CI, 9.1-21.0) versus ToGA regimens (7.5, 6.4-8.5), p < 0.001. Patients with HER2-IHC 3+ cancers had higher response rates than those with IHC 2+/FISH+, odds-ratio 1.97 (95% CI, 1.25-3.09). The results achieved with CAPOX-trastuzumab were comparable to those attained with ToGA regimens. FOLFOX-trastuzumab was superior to ToGA schemes in terms of overall survival (OS), with a greater magnitude of effect in IHC 2+/FISH+ tumors (HR 0.47, 0.24-0.92) compared with IHC 3+ (HR 0.69, 0.49-0.96), and in diffuse (HR 0.37, 0.20-0.69) versus intestinal-type tumors (HR 0.76, 0.54-1.06). Conclusion: We have updated the external validity of clinical trials with trastuzumab in first-line treatment of gastric cancer. Our data confirm the comparable outcomes of ToGA regimens and CAPOX-trastuzumab in clinical practice and point toward a possible benefit of FOLFOX-trastuzumab, contingent on the subtypes typically less sensitive to trastuzumab, to be confirmed in clinical trials

Tratamiento multicomponente del tabaquismo en Atención Primaria: seguimiento transcurridos más de 5 años

Resumen: Objetivos: Analizar la eficacia de un tratamiento multicomponente para dejar de fumar llevado a cabo en Atención Primaria y evaluar la evolución del consumo de tabaco que tuvieron las personas que participaron, transcurridos más de 5 años desde la finalización del tratamiento. Diseño: Estudio longitudinal de 307 personas participantes en un programa multicomponente en formato grupal de deshabituación de tabaco. Emplazamiento: Centro de Salud de Atención Primaria de Santander. Participantes: Personas fumadoras de la Zona Básica de Salud que deseaban dejar de fumar entre 2006 y 2012 y solicitaron ayuda. Intervenciones: Tratamiento multicomponente de 5 sesiones presenciales y seguimiento hasta los 12 meses. Mediciones principales: La actividad se evaluó en 263 sujetos, una vez transcurridos más de 5 años desde que finalizaron el tratamiento. Los resultados de abstinencia continua y puntual se obtuvieron por autodeclaración y los datos registrados en la historia clínica. La puntual se validó también con cooximetría. Resultados: Al año declararon abstinencia continua el 42,7% de las participantes. Transcurridos entre 5 y 12 años, la abstinencia continua declarada mayor de 12 meses fue del 40,7%. No volvieron a fumar desde que finalizaron el tratamiento 66 personas. El 68,0% de las que recayeron realizaron nuevos intentos y de ellas el 45,5% solicitaron ayuda para dejar de fumar. Conclusiones: El tratamiento multicomponente propuesto es eficaz. La abstinencia a los 12 meses predice el mantenimiento a largo plazo y participar en grupos de deshabituación favorece la realización de nuevos intentos en caso de recaída y la solicitud de ayuda para dejar de fumar. Abstract: Objectives: To analyze the effectiveness of a multicomponent treatment for smoking cessation carried out in primary care and to evaluate the evolution of the consumption of tobacco that the people who participated had, more than 5 years after the end of the treatment. Design: Longitudinal study of 307 participants in a multicomponent program in group format of tobacco cessation. Emplacement: Santander (Spain) Primary Care Health Center. Participants: Smokers from the basic health zone who wanted to quit smoking between 2006 and 2012 and requested help. Interventions: Multicomponent treatment of 5 face-to-face sessions and follow-up for up to 12 months. Primary measurements: The activity was evaluated in 263 participants more than 5 years after the end of treatment. The results of continuous and punctual withdrawal were obtained by self-declaration and the data recorded in the medical record. The punctual was also validated with co-oximetry. Results: After a year 42.7% of participants declared continuous abstinence. From 5 to 12 years later, the continuous declared abstinence further than 12 months was 40.7%. They did not smoke again since the end of the treatment 66 people; 68.0% of those who relapsed made new attempts and 45.5% of them requested help to quit smoking. Conclusions: The proposed multi-component treatment is effective. Abstinence at 12 months predicts long-term maintenance and participating in disabling groups favors further attempts in case of relapse and the request for help to quit smoking