Efecto de la radiación ultravioleta (RUV) sobre los procesos de estrés oxidativo e inmunodepresión cutánea. Efecto protector"

El estrés oxidativo es una consecuencia directa del necesario consumo de oxígeno por parte de los organismos vivos aerobios, y su intensidad y consecuencias dependen de la capacidad de nuestros sistemas de defensa específicos para contrarrestar las especies reactivas del oxígeno (ERO) generadas, entre las cuales destacan los radicales libres del oxígeno (RLO). Numerosas circunstancias, fisiológicas o patológicas, pueden incrementar la producción de RLO y, por tanto, aumentar el estrés oxidativo. Entre ellas está la radiación UV (RUV), a la que todos nosotros estamos expuestos con mayor o menor intensidad y asiduidad.La exposición a la RUV es causa de numerosas alteraciones cutáneas, incluido el cáncer de piel. El progresivo aumento de este tipo de cáncer en las últimas décadas ha suscitado una gran preocupación sanitaria y social, por lo cual todos los aspectos relacionados con la fotoprotección son objeto de investigación desde diversos puntos de vista: físico, químico, biológico y sanitario.En este sentido, no cabe duda de que actualmente disponemos de una información muy valiosa acerca de los riesgos de la exposición a la RUV y, al mismo tiempo, existen fotoprotectores muy eficaces y desarrollados con criterios científicos avanzados. No obstante, y a pesar de que el consumo de fotoprotectores no cesa de incrementarse, la incidencia del cáncer de piel sigue aumentando. Con este trabajo pretendemos llamar la atención sobre la falsa sensación de seguridad que puede derivarse del uso incorrecto de fotoprotectores y sobre la necesidad de revisar en profundidad algunos de los conceptos sobre los que se basa la fotoprotección.En consecuencia, en el protocolo experimental desarrollado, se irradiaron lotes de animales (ratas hairless) de forma aguda, crónica o bien tratados con filtros solares. Y se determinaron parámetros bioquímicos reflejo de los radicales libres tanto en sangre como en epidermis. También se determinó el daño producido sobre el material genético, y el número y capacidad funcional de las células inmunitarias de la piel (células de Langerhans). Las principales conclusiones que se derivan de este trabajo son las siguientes:1. La RUV, a partir de dosis equivalentes a 1 DEM (dosis eritemógena mínima), induce cambios sistémicos y cutáneos en los sistemas de defensa específicos frente al estrés oxidativo, simultáneamente a la pérdida de la inmunidad cutánea.2. Dosis suberitemógenas y repetidas de RUV, asimilables a las que recibe una persona sometida a exposiciones moderadas al sol, también determinan pérdida de la inmunidad cutánea y alteraciones indicativas de desequilibrio oxidativo.3. El número de células de Langerhans de la epidermis se correlaciona con diversos parámetros sanguíneos y epidérmicos relacionados con el estrés oxidativo. El hecho de que la actividad de la glutatión peroxidasa y la concentración de glutatión reducido eritrocitarios sean predictores del número de células de Langerhans, sugiere la posibilidad de que dichos parámetros constituyan una alternativa válida para evaluar indirectamente la capacidad inmunitaria cutánea.4. La determinación del factor de protección solar, basado exclusivamente en la capacidad de prevención del eritema, no ofrece las garantías necesarias para una fotoprotección segura frente a la RUV. Es necesario adoptar nuevos criterios de fotoprotección, basados en indicadores más sensibles y precoces que el eritema.5. Los valores del factor de protección solar que presentan los fotoprotectores actuales deben someterse a un juicio crítico. En este sentido, sería prudente reducir dichos valores a la mitad o a la tercera parte.6. Puesto que muchos de los efectos de la RUV derivan del estrés oxidativo, es muy recomendable desarrollar nuevas fórmulas fotoprotectoras que incluyan principios activos capaces de restaurar el equilibrio oxidativo y de neutralizar los efectos de los radicales libres.The oxidative stress is a direct consequence of the necessary consumption of oxygen by the living aerobic organisms, and its intensity and consequences depend on the capacity of specific defence systems to counteract the generated reactive oxygen species (ROS), among which the most relevant are the oxygen free radicals (OFR). Numerous circumstances, physiological or pathological, can increase the production of OFR and, therefore, increase the oxidative stress. Among them there is the UV radiation (UVR), to which we are all exposed with greater or smaller intensity and frequency. Exposition to UVR cause numerous cutaneous alterations, included the skin cancer. The progressive increase of this type of cancer in the last decades provoke a great social and sanitary concern; in consequence all the aspects related to photoprotection are object of investigation from different points of view: physical, chemical, biological and sanitary. In this sense, there is no doubt that at the present we have very valuable information about the risks of the exposition to the UVR and, at the same time, there are very efficient sunscreens, which are developed with advanced scientific criteria. Nevertheless, and in spite of the fact that the consumption of sunscreens increases day by day, the incidence of skin cancer increases continuously. With this work we intend to point out the false sensation of security that can be derived from the incorrect use of sunscreens and the need of a depth revision about some of the concepts which photoprotecction is based. Consequently, in the development of experimental protocols, we irradiated groups of animals (hairless rats) in the following way: acute radiations, chronic radiations and radiations with sunscreens. Different biochemical parameters related to OFR were determined in blood and in epidermis. The damage produced on the genetic material, and the number and functional capacity of the immune cells of the skin (Langerhans cells) were also evaluated. The main conclusions derived from this work are the following:1. UVR, from equivalent dose to 1 MED (minimal erithemal dose), induces systemic and cutaneous changes in the specific defence systems in front of oxidative stress, simultaneously to the loose of the cutaneous immunity. 2. Suberithemal and repeated doses of UVR, similar to the received by a person exposed to moderate sun exposure, also determine the lost of the cutaneous immunity and produce oxidative stress relative alterations.3. The number of epidermal Langerhans cells correlates with diverse blood and epidermal parameters related to oxidative stress. The fact that the eritrocytari activity of GPx and concentration of GSH can be predictors of the number of Langerhans cells, suggests the possibility that these parameters could constitute a valid alternative to indirectly evaluate the cutaneous immune capacity. 4. The evaluation of the sun protection factor (SPF), based exclusively in the capacity of prevention from erithema, does not offer the needed guarantees for a sure photoprotection against the UVR. It is necessary to adopt new criteria of photoprotection, based on premature and more sensitive indicators than the erithema. 5. The values of SPF of the sunscreens should be submitted to a critical judgment. In this sense, would be prudent the reduction of this values to the half or to the third part.Due to the fact that many of the effects of the UVR derive from the oxidative stress, is very recommendable to develop new photoprotective formulations that include capable active principles to restore the oxidative equilibrium and to neutralize the effects of free radicals

Evaluation of oxidative stress biomarkers in patients with chronic renal failure: a case control study

<p>Abstract</p> <p>Background</p> <p>Oxidative stress is related to several diseases, including chronic renal insufficiency. The disequilibrium in the oxidant-antioxidant balance is the result of several metabolic changes. The majority of studies to-date have evaluated the grade of oxidative stress with a single biomarker, or a very limited number of them.</p> <p>Findings</p> <p>The present study used several important biomarkers to establish a score relating to oxidative stress status (glutathione S-transferase, superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, reduced and oxidized glutathione, thiobarbituric acid reactive substances and hemolysis test). The score of oxidative stress (SOS) was then applied to a group of patients with renal insufficiency not on hemodialysis, and compared to healthy control individuals.</p> <p>The score for patients with chronic renal insufficiency was significantly different from that of the healthy control group (0.62 ± 1.41 vs. -0.05 ± 0.94; p < 0.001). The comparison between patients with chronic renal insufficiency and control individuals showed significant differences with respect to changes in the enzymatic antioxidant systems (glutathione S-transferase, glutathione reductase), non-enzymatic antioxidant system (oxidized glutathione) and oxidizability (hemolysis test) indicating significant oxidative stress associated with chronic renal insufficiency.</p> <p>Conclusions</p> <p>Patients with chronic renal insufficiency not on hemodialysis are susceptible to oxidative stress. The mechanisms that underlie this status are the consequence of changes in glutathione and related enzymes. The SOS scoring system is a useful biochemical parameter to evaluate the influence of oxidative stress on the clinical status of these patients.</p

Treatment of skeletal and non-skeletal alterations of Mucopolysaccharidosis type IVA by AAV-mediated gene therapy.

Mucopolysaccharidosis type IVA (MPSIVA) or Morquio A disease, a lysosomal storage disorder, is caused by N-acetylgalactosamine-6-sulfate sulfatase (GALNS) deficiency, resulting in keratan sulfate (KS) and chondroitin-6-sulfate accumulation. Patients develop severe skeletal dysplasia, early cartilage deterioration and life-threatening heart and tracheal complications. There is no cure and enzyme replacement therapy cannot correct skeletal abnormalities. Here, using CRISPR/Cas9 technology, we generate the first MPSIVA rat model recapitulating all skeletal and non-skeletal alterations experienced by patients. Treatment of MPSIVA rats with adeno-associated viral vector serotype 9 encoding Galns (AAV9-Galns) results in widespread transduction of bones, cartilage and peripheral tissues. This led to long-term (1 year) increase of GALNS activity and whole-body correction of KS levels, thus preventing body size reduction and severe alterations of bones, teeth, joints, trachea and heart. This study demonstrates the potential of AAV9-Galns gene therapy to correct the disabling MPSIVA pathology, providing strong rationale for future clinical translation to MPSIVA patients.We thank A. Arbos, S. Turon, M. Morro, J. Barrero, L. Hernandez, a. Vazquez, V. Melgarejo, and L. Noya for technical assistance. This work was supported by grants from the Ministerio de Ciencia, Innovacion y Universidades, Plan Nacional I+D+I and the European Union through Regional Development Funds (ERDF) (SAF2017-86166-R), Generalitat de Catalunya (2017SGR1508 and ICREA Academia Award to F.B.) and MPS Espana Foundation. This work is part of a public-private partnership on gene therapy between UAB and ESTEVE Pharmaceuticals, Spain. V.S. and G.E. received a predoctoral fellowship from the Generalitat de Catalunya, Spain.S

Chrononutrition and Polyphenols: Roles and Diseases

Biological rhythms can influence the activity of bioactive compounds, and at the same time, the intake of these compounds can modulate biological rhythms. In this context, chrononutrition has appeared as a research field centered on the study of the interactions among biological rhythms, nutrition, and metabolism. This review summarizes the role of phenolic compounds in the modulation of biological rhythms, focusing on their effects in the treatment or prevention of chronic diseases. Heterotrophs are able to sense chemical cues mediated by phytochemicals such as phenolic compounds, promoting their adaptation to environmental conditions. This is called xenohormesis. Hence, the consumption of fruits and vegetables rich in phenolic compounds exerts several health benefits, mainly attributed to the product of their metabolism. However, the profile of phenolic compounds present in plants differs among species and is highly variable depending on agricultural and technological factors. In this sense, the seasonal consumption of polyphenol-rich fruits could induce important changes in the regulation of physiology and metabolism due to the particular phenolic profile that the fruits contain. This fact highlights the need for studies that evaluate the impact of these specific phenolic profiles on health to establish more accurate dietary recommendations.España MINISTERIO DE ECONOMÍA, INDUSTRIA Y COMPETITIVIDAD (AGL2016-77105-R

A Pilot Study for Metabolic Profiling of Obesity-Associated Microbial Gut Dysbiosis in Male Wistar Rats

Obesity is one of the most incident and concerning disease worldwide. Definite strategies to prevent obesity and related complications remain elusive. Among the risk factors of the onset of obesity, gut microbiota might play an important role in the pathogenesis of the disease, and it has received extensive attention because it affects the host metabolism. In this study, we aimed to define a metabolic profile of the segregated obesity-associated gut dysbiosis risk factor. The study of the metabolome, in an obesity-associated gut dysbiosis model, provides a relevant way for the discrimination on the different biomarkers in the obesity onset. Thus, we developed a model of this obesity risk factors through the transference of gut microbiota from obese to non-obese male Wistar rats and performed a subsequent metabolic analysis in the receptor rats. Our results showed alterations in the lipid metabolism in plasma and in the phenylalanine metabolism in urine. In consequence, we have identified metabolic changes characterized by: (1) an increase in DG:34:2 in plasma, a decrease in hippurate, (2) an increase in 3-HPPA, and (3) an increase in o-coumaric acid. Hereby, we propose these metabolites as a metabolic profile associated to a segregated dysbiosis state related to obesity disease

FGF21 gene therapy as treatment for obesity and insulin resistance

Prevalence of type 2 diabetes (T2D) and obesity is increasing worldwide. Currently available therapies are not suited for all patients in the heterogeneous obese/T2D population, hence the need for novel treatments. Fibroblast growth factor 21 (FGF21) is considered a promising therapeutic agent for T2D/obesity. Native FGF21 has, however, poor pharmacokinetic properties, making gene therapy an attractive strategy to achieve sustained circulating levels of this protein. Here, adeno-associated viral vectors (AAV) were used to genetically engineer liver, adipose tissue, or skeletal muscle to secrete FGF21. Treatment of animals under long-term high-fat diet feeding or of ob/ob mice resulted in marked reductions in body weight, adipose tissue hypertrophy and inflammation, hepatic steatosis, inflammation and fibrosis, and insulin resistance for > 1 year. This therapeutic effect was achieved in the absence of side effects despite continuously elevated serum FGF21. Furthermore, FGF21 overproduction in healthy animals fed a standard diet prevented the increase in weight and insulin resistance associated with aging. Our study underscores the potential of FGF21 gene therapy to treat obesity, insulin resistance, and T2D.This work was supported by grants from Ministerio de Economía y Competi- tividad (MINECO) and FEDER, Plan Nacional I+D+I (SAF2014-54866R), andGeneralitat de Catalunya (2014SGR1669and ICREA Academia Award to F.B.), Spain, from the European Commission (MYOCURE, PHC-14-2015 667751) and the European Foundation for the Study of Diabetes (EFSD/MSD European Research Programme on Novel Therapies for Type 2 Diabetes,2013). V.J. was recipient of a post-doctoral research fellowship from EFSD/ Lilly. E.C., V.S., and C.M. received a predoctoral fellowship from Ministerio de Educación, Cultura y Deporte, and J.R. from Ministerio de Economía y Competitividad, Spain. The authors thank Marta Moya and Maria Molas for technical assistance.S

Alterations in Metabolome and Microbiome Associated with an Early Stress Stage in Male Wistar Rats: A Multi-Omics Approach

Stress disorders have dramatically increased in recent decades becoming the most prevalent psychiatric disorder in the United States and Europe. However, the diagnosis of stress disorders is currently based on symptom checklist and psychological questionnaires, thus making the identification of candidate biomarkers necessary to gain better insights into this pathology and its related metabolic alterations. Regarding the identification of potential biomarkers, omic profiling and metabolic footprint arise as promising approaches to recognize early biochemical changes in such disease and provide opportunities for the development of integrative candidate biomarkers. Here, we studied plasma and urine metabolites together with metagenomics in a 3 days Chronic Unpredictable Mild Stress (3d CUMS) animal approach that aims to focus on the early stress period of a well-established depression model. The multi-omics integration showed a profile composed by a signature of eight plasma metabolites, six urine metabolites and five microbes. Specifically, threonic acid, malic acid, alpha-ketoglutarate, succinic acid and cholesterol were proposed as key metabolites that could serve as key potential biomarkers in plasma metabolome of early stages of stress. Such findings targeted the threonic acid metabolism and the tricarboxylic acid (TCA) cycle as important pathways in early stress. Additionally, an increase in opportunistic microbes as virus of the Herpesvirales was observed in the microbiota as an effect of the primary stress stages. Our results provide an experimental biochemical characterization of the early stage of CUMS accompanied by a subsequent omic profiling and a metabolic footprinting that provide potential candidate biomarkers

Identification of Human IKK-2 Inhibitors of Natural Origin (Part I): Modeling of the IKK-2 Kinase Domain, Virtual Screening and Activity Assays

BACKGROUND: Their large scaffold diversity and properties, such as structural complexity and drug similarity, form the basis of claims that natural products are ideal starting points for drug design and development. Consequently, there has been great interest in determining whether such molecules show biological activity toward protein targets of pharmacological relevance. One target of particular interest is hIKK-2, a serine-threonine protein kinase belonging to the IKK complex that is the primary component responsible for activating NF-κB in response to various inflammatory stimuli. Indeed, this has led to the development of synthetic ATP-competitive inhibitors for hIKK-2. Therefore, the main goals of this study were (a) to use virtual screening to identify potential hIKK-2 inhibitors of natural origin that compete with ATP and (b) to evaluate the reliability of our virtual-screening protocol by experimentally testing the in vitro activity of selected natural-product hits. METHODOLOGY/PRINCIPAL FINDINGS: We thus predicted that 1,061 out of the 89,425 natural products present in the studied database would inhibit hIKK-2 with good ADMET properties. Notably, when these 1,061 molecules were merged with the 98 synthetic hIKK-2 inhibitors used in this study and the resulting set was classified into ten clusters according to chemical similarity, there were three clusters that contained only natural products. Five molecules from these three clusters (for which no anti-inflammatory activity has been previously described) were then selected for in vitro activity testing, in which three out of the five molecules were shown to inhibit hIKK-2. CONCLUSIONS/SIGNIFICANCE: We demonstrated that our virtual-screening protocol was successful in identifying lead compounds for developing new inhibitors for hIKK-2, a target of great interest in medicinal chemistry. Additionally, all the tools developed during the current study (i.e., the homology model for the hIKK-2 kinase domain and the pharmacophore) will be made available to interested readers upon request

Analysis of RXR/THR and RXR/PPARG2 heterodimerization by bioluminescence resonance energy transfer (BRET)

Nuclear receptors (NR) regulate transcription of genes involved in many biological processes such as development, cell proliferation, differentiation and cell death. Amongst them, PPARG2 and THR control tissue glucose and lipid homeostasis which are deregulated in severe pathophysiological conditions such as metabolic syndromes. Here, we describe a real time BRET approach to monitor heterodimerization between RXR and PPARG2 or THR in vitro or in living cells. The presence of a specific DNA target was required to induce in vitro a BRET shift reflecting heterodimerization of RXR/PPARG2 or RXR/THR. As in electrophoretic mobility shift assay (EMSA), the stringency and specificity of the BRET shift assay depended upon assay condition optimization including MgCl2 concentration. For the nuclear receptors, we found by mutagenesis analysis that each heterodimer partner must harbor an intact DNA binding domain to induce BRET and heterodimerization on a DNA target. Moreover the interaction between the PPARG2 ligand binding domain and the RXR DNA binding domain stabilized the heterodimer on its DNA target. BRET microscopy in living cells highlighted the heterodimerization of RXR/PPARG2 within the nucleus clustered in discrete foci that may represent active target gene transcription regulation regions. BRET imaging also suggested that heterodimerization between RXR and PPARG2 required the DNA binding of PPARG2. The BRET approach described here allowed us to study the dynamic interactions which exist between NR in vitro or in living cells and can provide important information on heterodimerization modes, affinity with a given RE and subcellular localization of the heterodimers. This method could be used to study real time changes of NR heterodimers occurring on DNA depending upon cell activation, chromatin state and help to define the mechanisms of ligands or drug action designed to target NRs

Photoperiodic Remodeling of Adiposity and Energy Metabolism in Non-Human Mammals

Energy homeostasis and metabolism in mammals are strongly influenced by seasonal changes. Variations in photoperiod patterns drive adaptations in body weight and adiposity, reflecting changes in the regulation of food intake and energy expenditure. Humans also show distinct patterns of energy balance depending on the season, being more susceptible to gaining weight during a specific time of the year. Changes in body weight are mainly reflected by the adipose tissue, which is a key metabolic tissue and is highly affected by circannual rhythms. Mostly, in summer-like (long-active) photoperiod, adipocytes adopt a rather anabolic profile, more predisposed to store energy, while food intake increases and energy expenditure is reduced. These metabolic adaptations involve molecular modifications, some of which have been studied during the last years and are summarized in this review. In addition, there is a bidirectional relation between obesity and the seasonal responses, with obesity disrupting some of the seasonal responses observed in healthy mammals, and altered seasonality being highly associated with increased risk of developing obesity. This suggests that changes in photoperiod produce important metabolic alterations in healthy organisms. Biological rhythms impact the regulation of metabolism to different extents, some of which are already known, but further research is needed to fully understand the relationship between energy balance and seasonality