Study of the impact of m6A RNA methylation in altered molecular mechanisms in colorectal cancer and its association with obesity

Although the etiology of colorectal cancer (CRC) is multifactorial and complex, due to the interaction of altered environmental and genetic mechanisms, obesity is considered a crucial risk factor in the initiation and progression of CRC. Alterations in epigenetic mechanisms, such as changes in the methylation pattern of certain genes, have been shown to have a clear effect on tumorigenesis and progression. In recent years, mounting evidence has revealed that the RNA modification machinery is often altered in human cancers, highlighting their enormous potential as drug targets or markers for diagnosis and early detection in obese subjects. Our objective was to identify in circulating leukocytes alterations in the epi-transcriptomic profile (m6A) of circulating leukocytes and their association with dysregulation of the RNA splicing machinery and alterations of the inflammatory response in patients with obesity-associated CRC. The study revealed significant differences in m6A RNA methylation of circulating leukocytes both between CRC patients and healthy overweight or obese patients, as well as between CRC patients with different BMI. It was also observed that obesity in CRC causes alterations in the expression of spliceosome components and factors related to RNA splicing and genes related to the inflammasome and inflammatory response in circulating leukocytes. Obesity in CRC is associated with alterations in the epitranscriptomic profile (m6A) in circulating leukocytes, in addition to alterations in the gene expression of the splicing machinery and inflammatory regulation.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

DNA catabolites in triathletes: effects of supplementation with an aronia–citrus juice (polyphenols-rich juice)

In this study we analyzed whether our aronia–citrus juice (ACJ, the composition is based on a mixture of 95% citrus juice with 5% of Aronia melanocarpa juice), rich in polyphenols, and physical exercise had an effect on seven catabolites of DNA identified in plasma and on a urine isoprostane (8-iso-PGF2α). Sixteen elite triathletes on a controlled diet for triathlon training (45 days) were used in this clinical trial. Our results show a decrease in the 8-hydroxy-2′-deoxyguanosine concentration due to chronic physical exercise. The ACJ intake and physical exercise maintained the guanosine-3′,5′-cyclic monophosphate plasmatic concentrations and decreased the concentration of 8-hydroxyguanine as well as urinary values of 8-iso-PGF2α. Finally, we observed a significant increase in the 8-nitroguanosine levels in triathletes after ACJ intake, compared to the placebo stage. It is concluded that the combination of the intake of ACJ, rich in polyphenolic compounds, with adequate training was able to influence the plasmatic and urinary values of oxidative stress biomarkers. This suggests a positive effect on the oxidative damage and potential associations with DNA repair mechanisms.LAGF was awarded a pre-doctoral FPI fellowship (BES2012-060185) by the Spanish government. This study was supported by the project AGL2011-23690 (CICYT) (Spanish Ministry of Economy and Competitiveness). This work has been partially funded by the “Fundación Séneca de la Región de Murcia” Grupo de Excelencia 19900/GERM/15

Alteraciones del perfil epitranscriptómico (m6A) asociadas a mecanismos biológicos del cáncer colorrectal y obesidad.

La obesidad considerada un factor de riesgo crucial en el inicio y progresión del cáncer colorrectal, podría promover un microentorno favorable a la carcinogénesis mediado por alteraciones epitranscriptómicas, como la metilación m6A del ARN, destapándose como una base genética común en obesidad y cáncer, pudiendo participar en la progresión de ambas enfermedades. El objetivo de este estudio fue identificar en leucocitos circulantes, fuentes potenciales de marcadores diagnósticos no invasivos, la relación entre los perfiles epitranscriptómicos (m6A) de pacientes con CCR y distintos índices de masa corporal como posibles biomarcadores. Así como estudiar la asociación de las alteraciones de la metilación m6A del ARNm con mecanismos biológicos del cáncer colorrectal y obesidad. En este estudio se incluyeron 30 pacientes con CCR y 64 pacientes sin CCR, con distintos índices de IMC. Se analizó la metilación m6A del ARNm de leucocitos circulantes mediante RNA-seq y MeRIP-seq, además se realizaron análisis de expresión génica mediante el sistema de qPCR de alto rendimiento BioMark (Fluidigm). El estudio reveló que el ARNm de leucocitos circulantes de los sujetos con CCR o con sobrepeso u obesidad presentaron menor metilación que los sujetos que presentaron conjuntamente CCR e IMC>25 kg/m2. Además, en los sujetos con CCR y sobrepeso u obesidad se observó una disminución de la expresión génica de componentes del ayustosoma (RNU11 y RNU6), así como de factores asociados al ayuste del ARN (MAGOH, TIA 1, EIF4A3, TRA2B y SF3BTV2). En cuanto al efecto en la respuesta inflamatoria, en este grupo se observó una disminución de los niveles de expresión del inflamasoma (AIM2) y de varios genes relacionados con la inflamación. En conjunto, un IMC>25 kg/m2 en CCR se asocia con alteraciones del perfil epitranscriptómico (m6A) en leucocitos circulantes, además de alteraciones en la expresión génica de la maquinaria de ayuste y la respuesta inflamatoria.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Lipidomic approach in young adult triathletes: effect of supplementation with a polyphenols-rich juice on neuroprostane and F2-dihomo-isoprostane markers

The aim of the this study was to determine the effect of a polyphenols-rich juice (aronia-citrus juice, ACJ) on F4-neuroprostanes and F2-dihomo-isoprostanes—markers of oxidative stress associated with the central nervous system (CNS)—in 16 elite triathletes under a controlled diet for triathlon training (145 days). In the triathletes, a decrease of the lipid peroxidation markers after ACJ intake, associated with neuronal membrane degradation (10-epi-10-F4t-neuroprostane and 10-F4t-neuroprostane), was observed when compared with placebo stage values. Regarding the F2-dihomo-isoprostanes, a significant decrease of the neuromotor system damage biomarkers (17-F2t-dihomo-isoprostane) with an increase of training load during the study was observed, although the decrease of the load training at the last stage showed a significant increase of the values of ent-7-(RS)-7-F2t-dihomo-IsoP, suggesting a possible role in adaptation post-training. On the other hand, the changes in the excretion of 17-epi-17-F2t-dihomo-IsoP provided a positive connection between physical exercise and ACJ intake. Thus, the results showed in this clinical study in young triathletes will help to elucidate novel interactions and mechanisms between the excretion of lipid peroxidation metabolites from CNS, supplementation of polyphenols-rich juice in the diet and physical exercise during a training season.This study was supported by the project AGL2011-23690 (CICYT) (Spanish Ministry of Economy and Competitiveness). This work has been partially funded by the “Fundación Séneca de la Región de Murcia” Grupo de Excelencia 19900/GERM/15. LAGF was granted a pre-doctoral FPI fellowship (BES2012-060185) by the Spanish government

8-oxoguanine DNA glycosylase 1 upregulation as a risk factor for obesity and colorectal cancer

DNA damage has been extensively studied as a potentially helpful tool in assessing and preventing cancer, having been widely associated with the deregulation of DNA damage repair (DDR) genes and with an increased risk of cancer. Adipose tissue and tumoral cells engage in a reciprocal interaction to establish an inflammatory microenvironment that enhances cancer growth by modifying epigenetic and gene expression patterns. Here, we hypothesize that 8-oxoguanine DNA glycosylase 1 (OGG1)—a DNA repair enzyme—may represent an attractive target that connects colorectal cancer (CRC) and obesity. In order to understand the mechanisms underlying the development of CRC and obesity, the expression and methylation of DDR genes were analyzed in visceral adipose tissue from CRC and healthy participants. Gene expression analysis revealed an upregulation of OGG1 expression in CRC participants (p < 0.005) and a downregulation of OGG1 in normal-weight healthy patients (p < 0.05). Interestingly, the methylation analysis showed the hypermethylation of OGG1 in CRC patients (p < 0.05). Moreover, expression patterns of OGG1 were found to be regulated by vitamin D and inflammatory genes. In general, our results showed evidence that OGG1 can regulate CRC risk through obesity and may act as a biomarker for CRC.Partial funding for open access charge: Universidad de Málag

Assessment oxidative stress biomarkers –neuroprostanes and dihomo-isoprostanes- in elite triathletes urine after two weeks of moderate altitude training

This randomized and controlled trial investigated whether the increase in elite training at different altitudes altered the oxidative stress biomarkers of the nervous system. This is the first study to investigate four F4-neuroprostanes and four F2-dihomo-isoprostanes quantified in 24-hour urine. The quantification was carried out by Ultra High Pressure Liquid Chromatography-triple Quadrupole-Tandem Mass Spectrometry (UHPLC-QqQ-MS/MS). Sixteen elite triathletes agreed to participate in the project. They were randomized in two groups, a group submitted to Altitude Training (n=8) and a group submitted to Sea Level Training (n=8), with a Control group of non-athletes (n=8). After experimental period, the Altitude Training group triathletes gave significant data: 17-epi-17-F2t-dihomo-IsoP (from 5.2 ± 1.4 µg/mL 24 h-1 to 6.6 ± 0.6 µg/mL 24 h-1), ent-7(RS)-7-F2t-dihomo-IsoP (from 6.6 ± 1.7 µg/mL 24 h-1 to 8.6 ± 0.9 µg /mL 24 h-1), and ent-7-epi-7-F2t-dihomo-IsoP (from 8.4 ± 2.2 µg/mL 24 h-1 to 11.3 ± 1.8 µg/mL 24 h-1) increased, while, of the neuronal degeneration-related compounds, only 10-epi-10-F4t-NeuroP (8.4 ± 1.7 µg/mL 24 h-1) and 10-F4t-NeuroP (5.2 ± 2.9 µg/mL 24 h-1) were detected in this group. For the control group and sea level training groups, no significant changes had occurred at the end of the 2-weeks experimental period. Therefore, and as the main conclusion, the training at moderate altitude increased the F4-NeuroPs- and F2-dihomo-isoPs-related oxidative damage of the central nervous system (CNS) compared to similar training at sea level.This study was supported by the project AGL2011-23690 (CICYT) (Spanish Ministry of Economy and Competitiveness). LAGF was granted with a pre-doctoral FPI fellowship BES2012-060185 by the Spanish government. The authors are also grateful to the University of Alicante for its collaboration. Sonia Medina was appointed under a research contract from the project AGL2011-23690 (CICYT)

The effects of graded levels of calorie restriction : XVI. Metabolomic changes in the cerebellum indicate activation of hypothalamocerebellar connections driven by hunger responses

The work was supported by the UK Biotechnology and Biological Sciences Research Council BBSRC (BB/G009953/1, BB/P009875/1 and BB/J020028/1 to J.R.S.) and a grant from the National Science foundation of China also to J.R.S. A studentship supported C.L.G. from the BBSRC EastBio Doctoral Training Partnership (1438803). C.L.G. received support from the laboratory of D.E.L.P.; D.E.L.P was supported in part by National Institute of Health grant AGO49494.Peer reviewedPostprin

Snapshot situation of oxidative degradation of the nervous system, kidney, and adrenal glands biomarkers-neuroprostane and dihomo-isoprostanes- urinary biomarkers from infancy to elderly adults

International audienceWe analyzed biomarkers of lipid peroxidation of the nervous system-F 2-dihomo-isoprostanes, F 3-neuropros-tanes, and F 4-neuroprostanes-in urine samples from 158 healthy volunteers ranging from 4 to 88 years old with the aim of analyzing possible associations between their excretion values and age (years). Ten biomarkers were screened in the urine samples by UHPLC-QqQ-MS/MS. Four F 2-dihomo-isoprostanes (ent−7-(R)−7-F 2t-dihomo-isoprostane, ent−7-epi−7-F 2t-dihomo-isoprostane, 17-F 2t-dihomo-isoprostane, 17-epi−17-F 2t-diho-mo-isoprostane), and one DPA-neuroprostane (4-F 3t-neuroprostane) were detected in the samples. On the one hand, we found a significant, positive correlation (Rho: 0.197, P=0.015) between the age increase and the amount of total F 2-dihomo-IsoPs. On the other hand, the values were significantly higher in the childhood group (4-12 years old), when compared to the adolescence group (13-17 years old) and the young adult group (18-35 years old). Surprisingly, no significant differences were found between the middle-aged adults (36-64 years old) and the elderly adults (65-88 years old). We display a snapshot situation of excretory values of oxidative stress biomarkers of the nervous system, using healthy volunteers representative of the different stages of human growth and development. The values reported in this study could be used as a basal or starting point in clinical interventions related to aging processes and/or pathologies associated with the nervous system

Aronia–citrus juice (polyphenol-rich juice) intake and elite triathlon training: a lipidomic approach using representative oxylipins in urine

In the present study, we examined whether particular urinary oxylipins (isoprostanes (IsoPs), leukotrienes (LTs), prostaglandins (PGs), and thromboxanes (TXs)) in 16 elite triathletes could alter during 145 days of training. Within this time span, 45 days were dedicated to examining the effects of the intake of a beverage rich in polyphenols (one serving: 200 mL per day) supplemented in their diet. The beverage was a mixture of citrus juice (95%) and Aronia melanocarpa juice (5%) (ACJ). Fifty-two oxylipins were analyzed in the urine. The quantification was carried out using solid-phase extraction, liquid chromatography coupled with triple quadrupole mass spectrometry. The physical activity decreased the excretion of some PG, IsoP, TX, and LT metabolites from arachidonic acid, γ-dihomo-linolenic acid, and eicosapentaenoic acid. The ACJ also reduced the excretion of 2,3-dinor-11β-PGF2α and 11-dehydro-TXB2, although the levels of other metabolites increased after juice supplementation (PGE2, 15-keto-15-F2t-IsoP, 20-OH-PGE2, LTE4, and 15-epi-15-E2t-IsoP), compared to the placebo. The metabolites that increased in abundance have been related to vascular homeostasis and smooth muscle function, suggesting a positive effect on the cardiovascular system. In conclusion, exercise influences mainly the decrease in oxidative stress and the inflammation status in elite triathletes, while ACJ supplementation has a potential benefit regarding the cardiovascular system that is connected in a synergistic manner with elite physical activity.This study was supported by the Project AGL2011-23690 (CICYT) (Spanish Ministry of Economy and Competitiveness). This work was partially funded by the “Fundación Séneca de la Región de Murcia” Grupo de Excelencia 19900/GERM/15. This work is included in the framework of the collaboration between the Spanish Research Council (CEBAS-CSIC) and CNRS-University of Montpellier as “Projets Internationaux de Cooperation Scientifique” (PICS-2015-261141). LAGF was granted a pre-doctoral FPI fellowship by the Spanish government as well as a scholarship that allowed the collaboration with Dr Craig Wheelock’s group (Department of Medical Biochemistry and Biophysics (MBB)) at the Karolinska Institute. The authors are also grateful to the University of Alicante for its collaboration. Sonia Medina was appointed under a research contract from the Project AGL2011-23690 (CICYT)