122 research outputs found

    Autophagy upregulation and loss of NF-kB in oxidative stress-related immunodeficient SAMP8 mice

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    Aged spleens from senescence-accelerated prone mice 8 (SAMP8) and senescence-accelerated resistant mice 1 (SAMR1) were examined to determine whether sex or melatonin had an effect on oxidative stress-related immune impairments. We observed that the immunosenescence of SAMP8 mice was associated with a redox imbalance, leading to an age-related increase in oxidative damage, resulting from a decrease in antioxidant defense and protease activity. Moreover, increased apoptotic cell death, a decrease in proliferative activity and the loss of NF-kB activation were also related to the immunodeficiency seen in SAMP8 compared to SAMR1 mice. Females demonstrated higher oxidative stress-related alterations in the immune response, and subsequent, melatonin treatment provided the best protective effects. Pathways involved in autophagy were upregulated in SAMP8 as an adaptive response to oxidative stress, in an attempt to rescue the cell from increased apoptosis and age-related immunodeficiency. However, the NF-kB signaling and autophagic processes were unaffected by treatment with melatonin. Therefore, we propose a key role for NF-kB signaling and autophagy in the oxidative stress-related immunosenescent spleens of SAMP8 mice

    Effect of animal mixing as a stressor on biomarkers of autophagy and oxidative stress during pig muscle maturation

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    The objective of this work was to study the postmortem evolution of potential biomarkers of autophagy (Beclin 1, LC3-II/LC3-I ratio) and oxidative stress (total antioxidant activity, TAA; superoxide dismutase activity, SOD and catalase activity, CAT) in the Longissimus dorsi muscle of entire male ((Large White × Landrace) × Duroc) pigs subjected to different management treatments that may promote stress, such as mixing unfamiliar animals at the farm and/or during transport and lairage before slaughter. During the rearing period at the farm, five animals were never mixed after the initial formation of the experimental groups (unmixed group at the farm, UF), whereas 10 animals were subjected to a common routine of being mixed with unfamiliar animals (mixed group at the farm, MF). Furthermore, two different treatments were used during the transport and lairage before slaughter: 10 pigs were not mixed (unmixed group during transport and lairage, UTL), whereas five pigs were mixed with unfamiliar animals on the lorry and during lairage (mixed group during transport and lairage, MTL). These mixing treatments were then combined into three pre-slaughter treatments – namely, UF-UTL, MF-UTL and MF-MTL. The results show that MF-UTL and MF-MTL increased significantly the muscle antioxidant defense (TAA, SOD and CAT) at short postmortem times (4 and 8 h; P < 0.001), followed by an earlier depletion of the antioxidant activity at 24 h postmortem (P < 0.05). We also found that mixing unfamiliar animals, both at the farm and during transport and lairage, triggers postmortem muscle autophagy, which showed an earlier activation (higher expression of Beclin 1 and LC3-II/LC3-I ratio at 4 h postmortem followed by a decreasing pattern of this ratio along first 24 h postmortem) in the muscle tissues of animals from the MF-UTL and MF-MTL groups, as an adaptive strategy of the muscle cells for counteracting induced stress. From these results, we propose that monitoring the evolution of the main biomarkers of autophagy (Beclin 1, LC3-II/LC3-I ratio) and muscle antioxidant defense (TAA, SOD, CAT) in the muscle tissue within the first 24 h postmortem may help the detection of animal stress and its potential effect on the postmortem muscle metabolism.info:eu-repo/semantics/publishedVersio

    Defective Adaption of Erythrocytes During Acute Hypoxia Injury in an Elderly Population

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    The present study investigated the changes in several erythrocyte oxidative stress biomarkers in hypoxic elderly individuals to analyze the deleterious effects of low oxyhemoglobin saturation in an elderly population. We collected blood samples from one normoxic middle-aged group and two groups composed of individuals older than 75 years of age: one normoxic group and one hypoxic group. Aging appeared to provoke a defective erythrocyte antioxidant defense associated with increased oxidative damage in the elderly population. Acute hypoxia activated an insufficient antioxidant defense response as suggested by the oxidative damage observed. The oxidative imbalance presented in older participants and increased in hypoxia participants had a direct effect on glyceraldehyde-3-phosphate dehydrogenase cell distribution. Oxidative stress levels altered Band 3 protein and mediated caspase-3 activation in erythrocyte from the aged group although it was not extended to hypoxic individuals. Therefore, aged participants appeared to activate an insufficient antioxidant response against hypoxia-related oxidative stress.Instituto Carlos III (FISS-06-RD06/0013/0011); Ministerio de Agricultura and FEDER (INIA RTA2007-00087-C02-02); FICYT (Gobierno del Principado de Asturias) (IB09-134)

    Preliminary definitions for the sonographic features of synovitis in children

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    Objectives Musculoskeletal ultrasonography (US) has the potential to be an important tool in the assessment of disease activity in childhood arthritides. To assess pathology, clear definitions for synovitis need to be developed first. The aim of this study was to develop and validate these definitions through an international consensus process. Methods The decision on which US techniques to use, the components to be included in the definitions as well as the final wording were developed by 31 ultrasound experts in a consensus process. A Likert scale of 1-5 with 1 indicating complete disagreement and 5 complete agreement was used. A minimum of 80% of the experts scoring 4 or 5 was required for final approval. The definitions were then validated on 120 standardized US images of the wrist, MCP and tibiotalar joints displaying various degrees of synovitis at various ages. Results B-Mode and Doppler should be used for assessing synovitis in children. A US definition of the various components (i.e. synovial hypertrophy, effusion and Doppler signal within the synovium) was developed. The definition was validated on still images with a median of 89% (range 80-100) of participants scoring it as 4 or 5 on a Likert scale. Conclusions US definitions of synovitis and its elementary components covering the entire pediatric age range were successfully developed through a Delphi process and validated in a web-based still images exercise. These results provide the basis for the standardized US assessment of synovitis in clinical practice and research
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