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Schmidt H.H.H.W.,Maastricht University | Stocker R.,Victor Chang Cardiac Research Institute | Stocker R.,University of New South Wales | Vollbracht C.,Fresenius University of Applied Sciences | And 7 more authors.
Antioxidants and Redox Signaling | Year: 2015

Significance: It is generally accepted that reactive oxygen species (ROS) scavenging molecules or antioxidants exert health-promoting effects and thus their consumption as food additives and nutraceuticals has been greatly encouraged. Antioxidants may be beneficial in situations of subclinical deficiency and increased demand or acutely upon high-dose infusion. However, to date, there is little clinical evidence for the long-term benefit of most antioxidants. Alarmingly, recent evidence points even to health risks, in particular for supplements of lipophilic antioxidants. Recent Advances: The biological impact of ROS depends not only on their quantities but also on their chemical nature, (sub)cellular and tissue location, and the rates of their formation and degradation. Moreover, ROS serve important physiological functions; thus, inappropriate removal of ROS may cause paradoxical reductive stress and thereby induce or promote disease. Critical Issues: Any recommendation on antioxidants must be based on solid clinical evidence and patient-relevant outcomes rather than surrogate parameters. Future Directions: Such evidence-based use may include site-directed application, time-limited high dosing, (functional) pharmacological repair of oxidized biomolecules, and triggers of endogenous antioxidant response systems. Ideally, these approaches need guidance by patient stratification through predictive biomarkers and possibly imaging modalities. Antioxid. Redox Signal. 23, 1130-1143. © 2015, Mary Ann Liebert, Inc. Source

Aldamiz-Echevarria T.,Hospital General Universitario Gregorio Maranon | Aldamiz-Echevarria T.,Institute Investigacion Sanitaria Gregorio Maranon IiSGM | Gonzalez-Garcia J.,Hospital Universitario La Paz | Gonzalez-Garcia J.,Institute Investigacion Sanitaria La Paz IdiPAZ | And 15 more authors.
Annals of Hepatology | Year: 2015

Background and rationale for the study. We assessed the association of CD4+ T-cell counts and HIV-RNA on sustained viral response (SVR) after therapy with pegylated interferon and ribavirin (PR) in HIV/HCV coinfected patients. We examined two large cohorts of coinfected patients treated with PR in Spain between 2000 and 2008. SVR was defined as undetectable HCV-RNA at 24 weeks after the end of PR. Results. We studied 1682 patients, of whom 38% achieved SVR. Baseline factors independently associated with reduced odds of SVR included genotype 1 or 4, HCV-RNA > 500,000 IU/mL, advanced liver fibrosis, CDC clinical category C, and detectable HIV-RNA. By multivariate logistic regression analysis, we found that, in comparison with patients with combination antiretroviral therapy (cART) and undetectable HIV-RNA, the odds ratio [95% confidence interval (CI)] of SVR was 0.56 (0.41-0.78) for cART and detectable HIV-RNA, 0.86 (0.56-2.57) for no-cART and detectable HIV-RNA, and 1.38 (0.74-2.57) for no-cART and undetectable HIV-RNA. Conclusions. Detectable HIV-RNA, but not CD4+ T-cell count, was associated with reduced odds of SVR. However, this finding was only confirmed for cART and detectable HIV-RNA, raising the question as whether this represents a true association of HIV-RNA on response to PR or a spurious association due to poor adherence to treatment. © 2015, Fundacion Clinica Medica Sur. All rights reserved. Source

Pajares M.,Institute Investigaciones Biomedicas Alberto Sols CSIC UAM | Pajares M.,Institute Investigacion Sanitaria La Paz IdiPAZ | Pajares M.,CIBER ISCIII | Jimenez-Moreno N.,Institute Investigaciones Biomedicas Alberto Sols CSIC UAM | And 13 more authors.
Redox Biology | Year: 2015

Intracellular proteolysis is critical to maintain timely degradation of altered proteins including oxidized proteins. This review attempts to summarize the most relevant findings about oxidant protein modification, as well as the impact of reactive oxygen species on the proteolytic systems that regulate cell response to an oxidant environment: the ubiquitin-proteasome system (UPS), autophagy and the unfolded protein response (UPR). In the presence of an oxidant environment, these systems are critical to ensure proteostasis and cell survival. An example of altered degradation of oxidized proteins in pathology is provided for neurodegenerative diseases. Future work will determine if protein oxidation is a valid target to combat proteinopathies. © 2015 The Authors. Source

Gonzalez-Rodriguez A.,Institute Investigaciones Biomedicas Alberto Sols CSIC UAM | Gonzalez-Rodriguez A.,Research Center Biomedica En Red Of Diabetes fermedades Metabolicas Asociadas Ciberdem | Gonzalez-Rodriguez A.,Hospital Universitario Santa Cristina | Santamaria B.,Institute Investigaciones Biomedicas Alberto Sols CSIC UAM | And 18 more authors.
Molecular Nutrition and Food Research | Year: 2015

Scope: Mice with deletion of insulin receptor substrate (IRS) 2 develop hyperglycaemia, impaired hepatic insulin signaling and elevated gluconeogenesis. Protein tyrosine phosphatase 1B (PTP1B) inhibition by resveratrol improves peripheral insulin sensitivity of these mice. Although resveratrol activates Sirtuin1 (Sirt1), the mechanisms underlying its beneficial effects are not totally elucidated. In this study, we have investigated whether Sirt1 mediates the effects of resveratrol in controlling insulin resistance in diabetic mice. Methods and results: We attempted to ameliorate peripheral insulin resistance in two diabetic models, Irs2-deficient (Irs2-/-) mice and streptozotocin (STZ)-injected mice by resveratrol treatment or Sirt1 overexpression. Resveratrol improved systemic insulin sensitivity of Irs2-deficient mice. Irs2-deficient mice are characterized by high levels of PTP1B expression in liver and muscle. Interestingly, resveratrol decreased PTP1B in both tissues, thereby restoring IRS1-mediated insulin signaling. Moreover, resveratrol also restored insulin sensitivity and hepatic insulin signaling in STZ-diabetic mice. In contrast, moderate overexpression of Sirt1 neither normalized PTP1B levels nor restored insulin signaling in Irs2-deficient mice or STZ-diabetic mice. Conclusion: Resveratrol improves peripheral insulin signaling independently of Sirt1 in diabetic mice in association with the inhibition of PTP1B and, therefore, this polyphenol could be an effective adjuvant for the treatment of diabetes. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Dao V.T.-V.,Maastricht University | Casas A.I.,Maastricht University | Maghzal G.J.,Victor Chang Cardiac Research Institute | Seredenina T.,University of Geneva | And 14 more authors.
Antioxidants and Redox Signaling | Year: 2015

Significance: Oxidative stress is suggested to be a disease mechanism common to a wide range of disorders affecting human health. However, so far, the pharmacotherapeutic exploitation of this, for example, based on chemical scavenging of pro-oxidant molecules, has been unsuccessful. Recent Advances: An alternative emerging approach is to target the enzymatic sources of disease-relevant oxidative stress. Several such enzymes and isoforms have been identified and linked to different pathologies. For some targets, the respective pharmacology is quite advanced, that is, up to late-stage clinical development or even on the market; for others, drugs are already in clinical use, although not for indications based on oxidative stress, and repurposing seems to be a viable option. Critical Issues: For all other targets, reliable preclinical validation and drug ability are key factors for any translation into the clinic. In this study, specific pharmacological agents with optimal pharmacokinetic profiles are still lacking. Moreover, these enzymes also serve largely unknown physiological functions and their inhibition may lead to unwanted side effects. Future Directions: The current promising data based on new targets, drugs, and drug repurposing are mainly a result of academic efforts. With the availability of optimized compounds and coordinated efforts from academia and industry scientists, unambiguous validation and translation into proof-of-principle studies seem achievable in the very near future, possibly leading towards a new era of redox medicine. Antioxid. Redox Signal. 23, 1113-1129. © 2015, Mary Ann Liebert, Inc. Source

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