Adaptive mechanisms to oxidative stress during aging

Meta-analysis reveals the species-, dose- and duration-dependent effects of cadmium toxicities in marine bivalves

Cadmium (Cd) is a typical pollutant in marine environment. Increasing studies have focused on the toxicological effects of Cd in marine bivalves. However, there were many conflicting findings of toxicological effects of Cd in marine bivalves. An integrated analysis performed on the published data of Cd toxicity in marine bivalves is still absent. In this study, a meta-analysis was performed on the toxic endpoints in bivalves exposed to aqueous-phase Cd from 87 studies screened from 1519 papers. Subgroup analyses were conducted according to the categories of species, tissue, exposure dose and duration. The results showed significant species-, duration- and dose-dependent responses in bivalves to aqueous-phase Cd exposure. In details, clams were more sensitive to Cd than oysters, mussels and scallops, indicated by the largest effect size in clams. Gill, hepatopancreas and hemolymph were top three tissues used to indicate Cd-induced toxicity and did not present a significant tissue-specific manner among them. With regard to toxicological effect subgroups, oxidative stress and detoxification were top two subgroups indicating Cd toxicities. Detoxification and genotoxicity subgroups presented higher response magnitudes. What is more, toxicological effect subgroups presented multiple dose- and duration-dependent curves. Oxidative stress and genotoxicity related endpoints presented significant increase trends with Cd exposure dose and were preferable biomarkers to marine Cd pollution. Detoxification and energy metabolism related endpoints showed inverted U-shaped and U-shaped dose-response curves, both of which could be explained by hormesis. The linear decrease in oxidative stress and energy metabolism related endpoints over time suggested their involvement into the adaptive mechanism in bivalves. Overall, this study provided not only a better understanding the responsive mechanisms of marine bivalves to Cd stress, but also a selection reference for biomarkers to aqueous-phase Cd pollution in marine environment.

Aging of Liver in Its Different Diseases

The proportion of elderly people in the world population is constantly increasing. With age, the risk of numerous chronic diseases and their complications also rises. Research on the subject of cellular senescence date back to the middle of the last century, and today we know that senescent cells have different morphology, metabolism, phenotypes and many other characteristics. Their main feature is the development of senescence-associated secretory phenotype (SASP), whose pro-inflammatory components affect tissues and organs, and increases the possibility of age-related diseases. The liver is the main metabolic organ of our body, and the results of previous research indicate that its regenerative capacity is greater and that it ages more slowly compared to other organs. With age, liver cells change under the influence of various stressors and the risk of developing chronic liver diseases such as non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), alcoholic steatohepatitis (ASH) and hepatocellular carcinoma (HCC) increases. It has been proven that these diseases progress faster in the elderly population and in some cases lead to end-stage liver disease that requires transplantation. The treatment of elderly people with chronic liver diseases is a challenge and requires an individual approach as well as new research that will reveal other safe and effective therapeutic modalities.

Synergistic protection of quercetin and lycopene against oxidative stress via SIRT1-Nox4-ROS axis in HUVEC cells

Oxidative stress is a potential factor in the promotion of endothelial dysfunction. In this research, flavonoids (quercetin, luteolin) combined with carotenoids (lycopene, lutein), especially quercetin-lycopene combination (molar ratio 5:1), prevented the oxidative stress in HUVEC cells by reducing the reactive oxygen species (ROS) and suppressing the expression of NADPH oxidase 4 (Nox4), a major source of ROS production. RNA-seq analysis indicated quercetin-lycopene combination downregulated inflammatory genes induced by H₂O₂, such as IL-17 and NF-κB. The expression of NF-κB p65 was activated by H₂O₂ but inhibited by the quercetin-lycopene combination. Moreover, the quercetin and lycopene combination promoted the thermostability of Sirtuin 1 (SIRT1) and activated SIRT1 deacetyl activity. SIRT1 inhibitor EX-527 attenuated the inhibitory effects of quercetin, lycopene, and their combination on the expression of p65, Nox4 enzyme, and ROS. Quercetin-lycopene combination could interact with SIRT1 to inhibit Nox4 and prevent endothelial oxidative stress, potentially contributing to the prevention of cardiovascular disease.

Emodin Prevented Depression in Chronic Unpredicted Mild Stress-Exposed Rats by Targeting miR-139-5p/5-Lipoxygenase

Background

The use of medicinal plant ingredients is one of the goals of developing potential drugs for treating depression. Compelling evidence suggests that anti-inflammatory medicines may block the occurrence of depression. We studied the effect of a natural compound, emodin, on the development of psychosocial stress-induced depression and the underlying mechanisms.

Methods

Chronic unpredicted mild stress (CUMS) for 7 weeks was performed to replicate psychosocial stress in rats. The sucrose preference test, force swimming test, and open field test were used to evaluate their behaviors. The differentially expressed proteins in the hippocampus were analyzed using proteomics. Nissl staining and Golgi staining were used to detect the loss of neurons and synapses, immunohistochemical staining was used to detect the activation of microglia, and the enzyme-linked immunosorbent assay was used to detect the levels of pro-inflammatory cytokines. Western blotting, immunofluorescence, and quantitative polymerase chain reaction were also performed.

Results

Hippocampal inflammation with up-regulated 5-lipoxygenase (5-LO) was observed in the depressed rats after CUMS exposure. The upregulation of 5-LO was caused by decreased miR-139-5p. To observe the effect of emodin, we screened out depression-susceptible (DeS) rats during CUMS and treated them with emodin (80 mg/kg/day). Two weeks later, emodin prevented the depression behaviors in DeS rats along with a series of pathological changes in their hippocampi, such as loss of neurons and spines, microglial activation, increased interleukin-1β and tumor necrosis factor-α, and the activation of 5-LO. Furthermore, we demonstrated that emodin inhibited its excess inflammatory response, possibly by targeting miR-139-5p/5-LO and modulating glycogen synthase kinase 3β and nuclear factor erythroid 2-related factor 2.

Conclusion

These results provide important evidence that emodin may be a candidate agent for the treatment of depression and established a key role of miR-139-5p/5-LO in the inflammation of depression.

PPARα Agonist, MHY3200, Alleviates Renal Inflammation during Aging via Regulating ROS/Akt/FoxO1 Signaling

PPARα is a ligand-dependent transcription factor and its activation is known to play an important role in cell defense through anti-inflammatory and antioxidant effects. MHY3200 (2-[4-(5-chlorobenzo[d]thiazol-2-yl)phenoxy]-2,2-difluoroacetic acid), a novel benzothiazole-derived peroxisome proliferator-activated receptor α (PPARα) agonist, is a synthesized PPARα activator. This study examined the beneficial effects of MHY3200 on age-associated alterations in reactive oxygen species (ROS)/Akt/forkhead box (FoxO) 1 signaling in rat kidneys. Young (7-month-old) and old (22-month-old) rats were treated with MHY3200 (1 mg/kg body weight/day or 3 mg/kg body weight/day) for two weeks. MHY3200 treatment led to a notable decrease in triglyceride and insulin levels in serum from old rats. The elevated kidney ROS level, serum insulin level, and Akt phosphorylation in old rats were reduced following MHY3200 treatment; moreover, FoxO1 phosphorylation increased. MHY3200 treatment led to the increased level of FoxO1 and its target gene, MnSOD. MHY3200 suppressed cyclooxygenase-2 expression by activating PPARα and inhibiting the activation of nuclear factor-κB (NF-κB) in the kidneys of old rats. Our results suggest that MHY3200 ameliorates age-associated renal inflammation by regulating NF-κB and FoxO1 via ROS/Akt signaling.

Deoiled sunflower seeds ameliorate depression by promoting the production of monoamine neurotransmitters and inhibiting oxidative stress

We aimed to evaluate the antidepressant activity of deoiled sunflower seeds (SFS), which are rich in tryptophan, in our mouse model and explored a possible mechanism of action. Male C57BL/6J mice were subjected to chronic unpredictable mild stress (CUMS) and were administered a diet containing SFS as the main protein source. SFS alleviated CUMS-induced depression-like behaviors, compared to the effects of a whey protein-based diet. This effect was related to increases in the levels of serotonin, dopamine, norepinephrine, acetylcholine, and brain-derived neurotrophic factor in SFS-fed mice. These changes accompanied the amelioration of inflammatory abnormalities and oxidative stress. SFS increased the aromatic amino acid levels, and the ratio of tryptophan to neutral amino acids. Furthermore, the antidepressant-like effects of SFS were involved in lipid, nucleotide, and amino acid metabolism. In summary, SFS was found to attenuate depression-like symptoms in mice. These antidepressant effects may be related to the increase in the levels of aromatic amino acids and neurotransmitters, amelioration of oxidative stress and inflammation, and the regulation of the levels of abnormal metabolites to the normal levels.

Resistance Training Associated with Dietetic Advice Reduces Inflammatory Biomarkers in the Elderly

Aging is a biological process during which chronic low-grade inflammation is present due to changes in the immune system of the elderly. The main objective of this study is to evaluate the effects of resistance training associated with dietary advice on chronic inflammation in the elderly. We conducted a prospective intervention study in which we evaluated anthropometric parameters and inflammatory biomarkers (CRP, IL-8, CCL-2, and leptin) in 40 elderly people before and after long-term progressive resistance training (19 weeks) associated with dietary advice. The participants trained twice a week on nonconsecutive days, and the training lasted one hour with an intensity of 60-85% of 1-MR. Dietary advice was explained in person and individually focusing on foods rich in compounds with anti-inflammatory and antioxidant properties. Participants were instructed at the beginning of the training program, and dietary advice was reinforced verbally weekly. There was an improvement in body composition evidenced by a reduction in waist circumference and body fat percentage and by the increase in arm circumference, calf circumference, and corrected arm muscle area. In addition, there was a reduction in the inflammatory biomarkers CCL-2 (p = 0.01) and leptin (p < 0.01). Resistance training associated with dietary guidance can contribute to a healthy aging due to observed improvements in body composition and in the inflammatory profile of the elderly.

Jugular infusion of arginine has a positive effect on antioxidant mechanisms in lactating dairy cows challenged intravenously with lipopolysaccharide1

The main purpose of this work was to evaluate the effects of jugular l-arginine infusion on antioxidant mechanisms in lactating dairy cows challenged intravenously with lipopolysaccharide (LPS). Eight multiparous Holstein cows (609 ± 32 kg) at midlactation were randomly assigned to 5-d jugular infusions of Control (saline), Arginine (Arg, 18 g/d), LPS (0.2 μg/kg BW per day), and LPS + Arginine (0.2 μg/kg BW per day of LPS and 18 g/d of Arg) in a replicated 4 × 4 Latin square design with 4 infusion periods separated by 10-d. Jugular solutions of saline, Arg, LPS, and LPS + Arg were continuously infused using peristaltic pumps for approximately 6 h/d. Jugular vein serum samples were obtained on the last day of each infusion period before infusion (0 h) and at 3- and 6-h postinfusion. Compared with LPS treatment, Arg infusion increased the total antioxidant capacity and activity of glutathione peroxidase, but decreased malondialdehyde concentration (P < 0.05). The concentration of nitric oxide in serum and the activity of nitric oxide synthase were greater in LPS treatment compared with saline and Arg (P < 0.05). The Arg treatment significantly increased the serum insulin concentration at 3-h postinfusion compared with the saline treatment (P < 0.05), and that of LPS and LPS + Arg treatments were in between Arg and LPS treatments. No treatment effect was observed on the activities of superoxide dismutase and catalase (P > 0.05). In conclusion, enhancing the supply of Arg during an inflammatory challenge enhances antioxidant mechanisms in lactating dairy cows.

Tai Chi is an effective form of exercise to reduce markers of frailty in older age

Frailty affects the quality of life of older age adults by limiting mobility, reducing physiological reserve and reducing independence. The frailty phenotype is typically characterised by exhaustion, loss or lack of physical activity, weight loss and weakness, although more recently there have been proposals to extend the frailty criteria to include physiological characteristics such as inflammation, oxidative stress and vascular function. Exercise has the potential to prevent, delay or even reverse frailty, but not all exercise is perceived as suitable for an older age population. The purpose of this study was to test Tai Chi and Zumba Gold® as exercise interventions in older age adults (65 to 75 years old) to improve characteristics related to the frailty phenotype. Muscle strength and flexibility (functional fitness as a measure of weakness), cardiorespiratory fitness, blood pressure, vascular function (FMD), markers of oxidative stress (total antioxidant capacity, malondialdehyde, 8-isoprostane, protein carbonyl), inflammation (CRP) and aspects of wellbeing related to exhaustion were assessed at baseline (pre-), 6 weeks (mid-) and 12 weeks (post-intervention). Both Tai Chi and Zumba Gold® improved systolic blood pressure, vascular function, and functional fitness following the 12 week intervention to a similar extent. Furthermore Antioxidant capacity was significantly increased (303 ± 15.56 vs. 336 ± 18.82 μm; p = 0.0028) and lipid oxidation significantly reduced (36.41 ± 6.4 vs 13.49 ± 2.5 pg/ml; p = 0.0042) after 12 weeks of Tai Chi compared to baseline. Anxiety, physical and mental fatigue decreased in both groups, with a greater decrease in mental fatigue in the Tai Chi group. Taken together, these changes suggest that Tai Chi has the potential to reduce outcomes related to the extended frailty phenotype in older age adults.

Stress-Based Production, and Characterization of Glutathione Peroxidase and Glutathione S-Transferase Enzymes From Lactobacillus plantarum

More attention has been recently directed toward glutathione peroxidase and s-transferase enzymes because of the great importance they hold with respect to their applications in the pharmaceutical field. This work was conducted to optimize the production and characterize glutathione peroxidase and glutathione s-transferase produced by Lactobacillus plantarum KU720558 using Plackett-Burman and Box-Behnken statistical designs. To assess the impact of the culture conditions on the microbial production of the enzymes, colorimetric methods were used. Following data analysis, the optimum conditions that enhanced the s-transferase yield were the De Man-Rogosa-Sharp (MRS) broth as a basal medium supplemented with 0.1% urea, 0.075% H₂O₂, 0.5% 1-butanol, 0.0125% amino acids, and 0.05% SDS at pH 6.0 and anaerobically incubated for 24 h at 40°C. The optimum s-transferase specific activity was 1789.5 U/mg of protein, which was ~12 times the activity of the basal medium. For peroxidase, the best medium composition was 0.17% urea, 0.025% bile salt, 7.5% Na Cl, 0.05% H₂O₂, 0.05% SDS, and 2% ethanol added to the MRS broth at pH 6.0 and anaerobically incubated for 24 h at 40°C. Furthermore, the optimum peroxidase specific activity was 612.5 U/mg of protein, indicating that its activity was 22 times higher than the activity recorded in the basal medium. After SDS-PAGE analysis, GST and GPx showed a single protein band of 25 and 18 kDa, respectively. They were able to retain their activities at an optimal temperature of 40°C for an hour and pH range 4–7. The 3D model of both enzymes was constructed showing helical structures, sheet and loops. Protein cavities were also detected to define druggable sites. GST model had two large pockets; 185Å3 and 71 Å3 with druggability score 0.5–0.8. For GPx, the pockets were relatively smaller, 71 Å3 and 32 Å3 with druggability score (0.65–0.66). Therefore, the present study showed that the consortium components as well as the stress-based conditions used could express both enzymes with enhanced productivity, recommending their application based on the obtained results.

Relation of Moderate Physical Activity to Blood Markers of Oxidative Stress and Antioxidant Defense in the Elderly

The aim of the present study was to establish whether markers of oxidative stress and the enzymatic defense system of the blood are related to moderate physical activity in younger old and the oldest old men. They were divided into four groups according to the age and level of physical activity (groups YN and YA—inactive and active younger old men aged 65-74 years, groups ON and OA—inactive and active oldest old men aged 90-99 years). Venous blood was collected from the subjects in the morning before breakfast. MDA concentration and antioxidant enzyme activities (SOD, CAT, GPx, and GR) in erythrocyte hemolysates were assayed. The concentration of isoprostanes (8-iso-PGF2α) and carbonyl groups in protein (CP) was measured in plasma and serum. All assayed antioxidant enzyme activities and the SOD/GPx ratios were significantly higher in the active younger old males than in all the inactive ones. In the group of oldest old active participants, only the GPx activity was significantly higher compared to the inactive oldest old males. The activity of CAT and GPx in the younger old inactive men was significantly lower than that in the oldest old inactive subjects. However, SOD, CAT, and GR activities and SOD/GPx ratio were significantly higher in the younger old active men compared to the oldest old active participants. The concentrations of isoprostanes, protein carbonyls, and MDA were significantly lower in both active and inactive younger old males than in the respective groups of the oldest old men and in both groups of active men, independently of age, compared to the respective inactive subjects. The present study confirmed that oxidative stress is related to age. Physical activity caused a decrease of oxidative stress markers independently of age and resulted in an increase of GPx activity in both younger old and the oldest old active groups.

Effects of flight activity and age on oxidative damage in the honey bee, Apis mellifera

Frequent and highly aerobic behaviors likely contribute to naturally occurring stress, accelerate senescence and limit lifespan. To understand how the physiological and cellular mechanisms that determine the onset and duration of senescence are shaped by behavioral development and behavioral duration, we exploited the tractability of the honey bee (Apis mellifera) model system. First, we determined whether a cause-effect relationship exists between honey bee flight and oxidative stress by comparing oxidative damage accrued from intense flight bouts to damage accrued from d-galactose ingestion, which induces oxidative stress and limits lifespan in other insects. Second, we experimentally manipulated the duration of honey bee flight across a range of ages to determine the effects on reactive oxygen species (ROS) accumulation and associated enzymatic antioxidant protective mechanisms. In bees fed d-galactose, lipid peroxidation (assessed by measuring malondialdehyde levels) was higher than in bees fed sucrose and age-matched bees with a high and low number of flight experiences collected from a colony. Bees with high amounts of flight experience exhibited elevated 8-hydroxy-2'-deoxyguanosine, a marker of oxidative DNA damage, relative to bees with less flight experience. Bees with high amounts of flight experience also showed increased levels of pro-oxidants (superoxide and hydrogen peroxide) and decreased or unchanged levels of antioxidants (superoxide dismutase and catalase). These data implicate an imbalance of pro- to anti-oxidants in flight-associated oxidative stress, and reveal how behavior can damage a cell and consequently limit lifespan.

Ginsenoside Rg1 ameliorates testicular senescence changes in D‑gal‑induced aging mice via anti‑inflammatory and antioxidative mechanisms

With the growing population, aging, extended lifespans and anti-aging have become popular areas of research in the life and social sciences. With increasing age, the structure and function of the testes, the spermatogenetic and androgen-producing organ in the male reproductive system, gradually declines. Ginsenoside Rg1 is an extract of Panax ginseng in traditional Chinese medicine. The extract facilitates anti-aging through its anti-inflammatory and antioxidant properties. However, it has not been reported whether ginsenoside Rg1 delays testicular aging. The present study established D-galactose (D-gal)-induced aging mouse models to examine the protective effects of ginsenoside Rg1 on the structure and function of the testes, and the underlying mechanism. A total of 60 healthy specific pathogen-free male C57BL/6 mice were randomly divided into four groups: Control group; Rg1 group; D-gal + Rg1 group; and D-gal group. The tissues of the mice were used for further experiments. The present study further investigated the effects of Rg1 on the volume of serum testosterone, the testicular index, testicular microscopic structures, the senescence of spermatogenetic cells, the apoptosis of spermatogenetic cells, the activity of the antioxidant enzymes, the levels of inflammatory cytokines, and the levels of S-phase kinase-associated protein (p19), cyclin-dependent kinase inhibitor 1 (p21) and cellular tumor antigen p53 (p53) in D-gal-induced aging mice. In general, compared with the D-gal group, the treatment of Rg1 increased the testis index, serum testosterone level and the active content of superoxide dismutase and the total antioxidant capacity. The percentage of senescence-associated β-galactosidase-positive cells, the level of apoptosis and the volume of methane dicarboxylic aldehyde, tumor necrosis factor-α, interleukin (IL)-1β and IL-6 in testicular tissues were significantly decreased, and the expression of p19, p53 and p21 was downregulated due to the treatment with Rg1. The results of the present study demonstrated that ginsenoside Rg1 was able to protect the testes against D-gal-induced aging in mice. In addition, the protective effect of Rg1 may be achieved via antioxidation and downregulation of the p19/p53/p21 signaling pathway.

The Impact of Aging on Cardio and Cerebrovascular Diseases

A growing number of evidences report that aging represents the major risk factor for the development of cardio and cerebrovascular diseases. Understanding Aging from a genetic, biochemical and physiological point of view could be helpful to design a better medical approach and to elaborate the best therapeutic strategy to adopt, without neglecting all the risk factors associated with advanced age. Of course, the better way should always be understanding risk-to-benefit ratio, maintenance of independence and reduction of symptoms. Although improvements in treatment of cardiovascular diseases in the elderly population have increased the survival rate, several studies are needed to understand the best management option to improve therapeutic outcomes. The aim of this review is to give a 360° panorama on what goes on in the fragile ecosystem of elderly, why it happens and what we can do, right now, with the tools at our disposal to slow down aging, until new discoveries on aging, cardio and cerebrovascular diseases are at hand.

Effects of age-related shifts in cellular function and local microenvironment upon the innate immune response to implants

The host macrophage response is now well recognized as a predictor of the success or failure of biomaterial implants following placement. More specifically, shifts from an "M1" pro-inflammatory towards a more "M2-like" anti-inflammatory macrophage polarization profile have been shown to result in enhanced material integration and/or tissue regeneration downstream. As a result, a number of biomaterials-based approaches to controlling macrophage polarization have been developed. However, the ability to promote such activity is predicated upon an in-depth, context-dependent understanding of the host response to biomaterials. Recent work has shown the impacts of both tissue location and tissue status (i.e. underlying pathology) upon the host innate immune response to implants, representing a departure from a focus upon implant material composition and form. Thus, the ideas of "biocompatibility," the host macrophage reaction, and ideal material requirements and modification strategies may need to be revisited on a patient, tissue, and disease basis. Immunosenescence, dysregulation of macrophage function, and delayed resolution of immune responses in aged individuals have all been demonstrated, suggesting that the host response to biomaterials in aged individuals should differ from that in younger individuals. However, despite the increasing usage of implantable medical devices in aged patients, few studies examining the effects of aging upon the host response to biomaterials and the implications of this response for long-term integration and function have been performed. The objective of the present manuscript is to review the putative effects of aging upon the host response to implanted materials and to advance the hypothesis that age-related changes in the local microenvrionement, with emphasis on the extracellular matrix, play a previously unrecognized role in determining the host response to implants.

Magnesium Lithospermate B from Salvia miltiorrhiza Bunge Ameliorates Aging-Induced Renal Inflammation and Senescence via NADPH Oxidase-Mediated Reactive Oxygen Generation

The present study was conducted to examine whether magnesium lithospermate B (MLB) extracted from Salviae miltiorrhizae radix was renoprotective in pathways related to age-related oxidative stress in aged rats. Magnesium lithospermate B was orally administered at a dose of 2- or 8-mg/kg body weight for 16 consecutive days, and the effects were compared with those of vehicle in old and young rats. Magnesium lithospermate B administration to old rats ameliorated renal oxidative stress through reduction of reactive oxygen species. The old rats exhibited a dysregulation of the expression of proteins related to oxidative stress and inflammation in the kidneys, and MLB administration significantly reduced the protein expression of major subunits of nicotinamide adenine dinucleotide phosphate oxidase (Nox4 and p22^phox ), phospho-p38, nuclear factor-kappa B p65, cyclooxygenase-2, and inducible nitric oxide synthase. In addition, MLB-treated old rats showed lower levels of senescence-related proteins such as p16, ADP-ribosylation factor 6, p53, and p21 through effects on the mitogen-activated protein kinase pathway. Magnesium lithospermate B administration also significantly attenuated the age-related increase in serum urea nitrogen, reflecting renal dysfunction, up-regulated podocyte structural proteins, and reduced renal structural injury. Our results provide important evidence that MLB reduces the renal damage of oxidative stress in old rats. Copyright © 2017 John Wiley & Sons, Ltd.

Exercise-induced hormesis and skeletal muscle health

Hormesis refers to the phenomenon that an exposure or repeated exposures of a toxin can elicit adaptive changes within the organism to resist to higher doses of toxin with reduced harm. Skeletal muscle shows considerable plasticity and adaptions in response to a single bout of acute exercise or chronic training, especially in antioxidant defense capacity and metabolic functions mainly due to remodeling of mitochondria. It has thus been hypothesized that contraction-induced production of reactive oxygen species (ROS) may stimulate the hormesis-like adaptations. Furthermore, there has been considerable evidence that select ROS such as hydrogen peroxide and nitric oxide, or even oxidatively degraded macromolecules, may serve as signaling molecules to stimulate such hermetic adaptations due to the activation of redox-sensitive signaling pathways. Recent research has highlighted the important role of nuclear factor (NF) κB, mitogen-activated protein kinase (MAPK), and peroxisome proliferator-activated receptor γ co-activator 1α (PGC-1α), along with other newly discovered signaling pathways, in some of the most vital biological functions such as mitochondrial biogenesis, antioxidant defense, inflammation, protein turnover, apoptosis, and autophagy. The inability of the cell to maintain proper redox signaling underlies mechanisms of biological aging, during which inflammatory and catabolic pathways prevail. Research evidence and mechanisms connecting exercise-induced hormesis and redox signaling are reviewed.

Redox signaling in skeletal muscle: role of aging and exercise

Skeletal muscle contraction is associated with the production of ROS due to altered O2 distribution and flux in the cell. Despite a highly efficient antioxidant defense, a small surplus of ROS, such as hydrogen peroxide and nitric oxide, may serve as signaling molecules to stimulate cellular adaptation to reach new homeostasis largely due to the activation of redox-sensitive signaling pathways. Recent research has highlighted the important role of NF-κB, MAPK, and peroxisome proliferator-activated receptor-γ coactivator-1α, along with other newly discovered signaling pathways, in some of the most vital biological functions, such as mitochondrial biogenesis, antioxidant defense, inflammation, protein turnover, apoptosis, and autophagy. There is evidence that the inability of the cell to maintain proper redox signaling underlies some basic mechanisms of biological aging, during which inflammatory and catabolic pathways eventually predominate. Physical exercise has been shown to activate various redox signaling pathways that control the adaptation and remodeling process. Although this stimulatory effect of exercise declines with aging, it is not completed abolished. Thus, aged people can still benefit from regular physical activity in the appropriate forms and at proper intensity to preserve muscle function.

Physical Activity- and Alcohol-dependent Association Between Air Pollution Exposure and Elevated Liver Enzyme Levels: An Elderly Panel Study

OBJECTIVES

The deleterious effects of air pollution on various health outcomes have been demonstrated. However, few studies have examined the effects of air pollution on liver enzyme levels.

METHODS

Blood samples were drawn up to three times between 2008 and 2010 from 545 elderly individuals who regularly visited a community welfare center in Seoul, Korea. Data regarding ambient air pollutants (particulate matter ≤2.5 μm [PM2.5], nitrogen dioxide [NO2], ozone [O3], carbon monoxide, and sulfur dioxide) from monitoring stations were used to estimate air pollution exposure. The effects of the air pollutants on the concentrations of three liver enzymes (aspartate aminotransferase [AST], alanine aminotransferase [ALT], and γ-glutamyltranspeptidase [γ-GTP)]) were evaluated using generalized additive and linear mixed models.

RESULTS

Interquartile range increases in the concentrations of the pollutants showed significant associations of PM2.5 with AST (3.0% increase, p=0.0052), ALT (3.2% increase, p=0.0313), and γ-GTP (5.0% increase, p=0.0051) levels; NO2 with AST (3.5% increase, p=0.0060) and ALT (3.8% increase, p=0.0179) levels; and O3 with γ-GTP (5.3% increase, p=0.0324) levels. Significant modification of these effects by exercise and alcohol consumption was found (p for interaction <0.05). The effects of air pollutants were greater in non-exercisers and heavy drinkers.

CONCLUSIONS

Short-term exposure to air pollutants such as PM2.5, NO2, and O3 is associated with increased liver enzyme levels in the elderly. These adverse effects can be reduced by exercising regularly and abstinence from alcohol.

Adaptive cellular stress pathways as therapeutic targets of dietary phytochemicals: focus on the nervous system

During the past 5 decades, it has been widely promulgated that the chemicals in plants that are good for health act as direct scavengers of free radicals. Here we review evidence that favors a different hypothesis for the health benefits of plant consumption, namely, that some phytochemicals exert disease-preventive and therapeutic actions by engaging one or more adaptive cellular response pathways in cells. The evolutionary basis for the latter mechanism is grounded in the fact that plants produce natural antifeedant/noxious chemicals that discourage insects and other organisms from eating them. However, in the amounts typically consumed by humans, the phytochemicals activate one or more conserved adaptive cellular stress response pathways and thereby enhance the ability of cells to resist injury and disease. Examplesof such pathways include those involving the transcription factors nuclear factor erythroid 2-related factor 2, nuclear factor-κB, hypoxia-inducible factor 1α, peroxisome proliferator-activated receptor γ, and forkhead box subgroup O, as well as the production and action of trophic factors and hormones. Translational research to develop interventions that target these pathways may lead to new classes of therapeutic agents that act by stimulating adaptive stress response pathways to bolster endogenous defenses against tissue injury and disease. Because neurons are particularly sensitive to potentially noxious phytochemicals, we focus on the nervous system but also include findings from other cell types in which actions of phytochemicals on specific signal transduction pathways have been more thoroughly studied.

5-Lypoxygenase products are involved in renal tubulointerstitial injury induced by albumin overload in proximal tubules in mice

The role of albumin overload in proximal tubules (PT) in the development of tubulointerstitial injury and, consequently, in the progression of renal disease has become more relevant in recent years. Despite the importance of leukotrienes (LTs) in renal disease, little is known about their role in tubulointerstitial injury. The aim of the present work was to investigate the possible role of LTs on tubulointerstitial injury induced by albumin overload. An animal model of tubulointerstitial injury challenged by bovine serum albumin was developed in SV129 mice (wild-type) and 5-lipoxygenase-deficient mice (5-LO^–/–). The changes in glomerular morphology and nestin expression observed in wild-type mice subjected to kidney insult were also observed in 5-LO^–/– mice. The levels of urinary protein observed in the 5-LO^–/– mice subjected or not to kidney insult were lower than those observed in respective wild-type mice. Furthermore, the increase in lactate dehydrogenase activity, a marker of tubule damage, observed in wild-type mice subjected to kidney insult did not occur in 5-LO^–/– mice. LTB₄ and LTD₄, 5-LO products, decreased the uptake of albumin in LLC-PK1 cells, a well-characterized porcine PT cell line. This effect correlated with activation of protein kinase C and inhibition of protein kinase B. The level of proinflammatory cytokines, tumor necrosis factor-α and interleukin (IL)-6, increased in mice subjected to kidney insult but this effect was not modified in 5-LO^–/– mice. However, 5-LO^–/– mice subjected to kidney insult presented lower macrophage infiltration and higher levels of IL-10 than wild-type mice. Our results reveal that LTs have an important role in tubulointerstitial disease induced by albumin overload.

Age-related inflammation and insulin resistance: a review of their intricate interdependency

Chronic inflammation is a major risk factor underlying aging and the associated diseases of aging; of particular interest is insulin resistance during aging. Chronic inflammation impairs normal lipid accumulation, adipose tissue function, mitochondrial function, and causes endoplasmic reticulum (ER) stress, which lead to insulin resistance. However, some studies show that insulin resistance itself amplifies chronic inflammation. The activity of the insulin-dependent Akt signaling pathway is highlighted because of its decrease in insulin-sensitive organs, like liver and muscle, which may underlie insulin resistance and hyperinsulinemia, and its increased levels in non-metabolic organs, such as kidney and aorta. In that the prevalence of obesity has increased substantially for all age groups in recent years, our review summarizes the data showing the involvement of chronic inflammation in obesity-induced insulin resistance, which perpetuates reciprocal interactions between the chronic inflammatory process and increased adiposity, thereby accelerating the aging process.

Anti-inflammation effect of Exercise and Korean red ginseng in aging model rats with diet-induced atherosclerosis

BACKGROUND/OBJECTIVES

The aim of this study was to investigate the effects of exercise (EX) and Korean red ginseng (KRG) on inflammation mechanism in aging model rats with diet-induced atherosclerosis.

MATERIALS/METHODS

Forty-eight male Sprague-Dawley rats were divided into 6 groups: Young control (Y-C), Aging control (A-C), A-C with HFD (AHF), AHF with EX (AHF-EX), AHF-EX with KRG (AHF-EX+RG), and AHF with KRG (AHF-RG). Aging was induced by D-gal (100mg/kg) and atherosclerosis was induced by HFD (60% fat) for 9 weeks. The experimental rats were performed swimming (60 min/day, 5 days/week) and supplied KRG orally (dose of 200 mg/kg) for 8 weeks. All rat aorta samples were harvested for biochemical and immunohistochemical analyses.

REULTS

The EX and KRG supplementation significantly inhibited body weight and levels of TC, TG, LDL-C, and enhance of HDL-C compared with untreated AHF groups. AHF-EX, AHF-EX+RG, and AHF-RG group showed a decreased plasma CRP and increase plasma NO activities compared to AHF group. In addition, these groups revealed reduced 4-HNE, NF-kB, TNF-α, IL-6, COX-2, ICAM-1, VCAM-1 and enhanced eNOS expression in the aorta.

CONCLUSION

These results suggest that EX alone, KRG alone, and combined treatment of EX and KRG may be an effective anti-inflammatory therapeutic for the atherosclerosis, possibly acting via the decreased of CRP and pro-inflammation proteins and the increased NO and eNOS.

Comparison of oxidative stress markers in umbilical cord blood after vaginal and cesarean delivery

Objective

The purpose of our study was to investigate the effect of the mode of delivery on the oxidant and antioxidant system in umbilical cord blood.

Methods

We performed gas analysis of umbilical venous blood and umbilical arterial blood immediately after delivery in 38 women; eighteen women had a vaginal delivery while 20 women delivered via cesarean section at over 37 weeks gestation. We examined lipid peroxide concentration by thiobarbituric acid reaction, protein carbonyl content by 2,4-dinitrophenylhydrazine reaction, and total antioxidant capacity by oxygen radical absorbance capacity assay.

Results

Lipid peroxide levels in umbilical venous blood were significantly higher in patients delivering by planned cesarean section (1.81 ± 0.06 nmol/mg protein) than those with vaginal delivery (1.24 ± 0.05 nmol/mg protein) (P < 0.05). Antioxidant capacity in umbilical venous blood was significantly higher in patients delivering by planned cesarean section (119.70 ± 0.13 µM/µL) than those with a vaginal delivery (118.70 ± 0.29 µM/µL) (P < 0.05). There was no significant difference in the carbonyl content of umbilical venous blood or in the lipid peroxide, carbonyl content, and total antioxidant capacity of umbilical arterial blood.

Conclusion

Lipid peroxidation levels and antioxidant capacity in umbilical venous blood were higher in patients delivering by planned cesarean section than those with a vaginal delivery. Therefore, we propose that both the mother and neonate are exposed to higher oxidative stress during cesarean section delivery.

Oxidative stress responses to a graded maximal exercise test in older adults following explosive-type resistance training

We recently demonstrated that low frequency, moderate intensity, explosive-type resistance training (EMRT) is highly beneficial in elderly subjects towards muscle strength and power, with a systemic adaptive response of anti-oxidant and stress-induced markers. In the present study, we aimed to evaluate the impact of EMRT on oxidative stress biomarkers induced in old people (70–75 years) by a single bout of acute, intense exercise. Sixteen subjects randomly assigned to either a control, not exercising group (n=8) or a trained group performing EMRT protocol for 12-weeks (n=8), were submitted to a graded maximal exercise stress test (GXT) at baseline and after the 12-weeks of EMRT protocol, with blood samples collected before, immediately after, 1 and 24 h post-GXT test. Blood glutathione (GSH, GSSG, GSH/GSSG), plasma malonaldehyde (MDA), protein carbonyls and creatine kinase (CK) levels, as well as PBMCs cellular damage (Comet assay, apoptosis) and stress–protein response (Hsp70 and Hsp27 expression) were evaluated. The use of multiple biomarkers allowed us to confirm that EMRT per se neither affected redox homeostasis nor induced any cellular and oxidative damage. Following the GXT, the EMRT group displayed a higher GSH/GSSG ratio and a less pronounced increase in MDA, protein carbonyls and CK levels compared to control group. Moreover, we found that Hsp70 and Hsp27 proteins were induced after GXT only in EMRT group, while any significant modification within 24 h was detected in untrained group. Apoptosis rates and DNA damage did not show any significant variation in relation to EMRT and/or GXT.

In conclusion, the adherence to an EMRT protocol is able to induce a cellular adaptation allowing healthy elderly trained subjects to cope with the oxidative stress induced by an acute exercise more effectively than the aged-matched sedentary subjects.

•

A low frequency, moderate intensity, explosive-type resistance training (EMRT) does not affect redox homeostasis at rest.

•

EMRT improves the general adaptive response to oxidative stress induced by graded maximal effort.

•

EMRT is effective intervention for improving the overall health of the older people.

Oxidative stress and vascular inflammation in aging

Vascular aging, a determinant factor for cardiovascular disease and health status in the elderly, is now viewed as a modifiable risk factor. Impaired endothelial vasodilation is a early hallmark of arterial aging that precedes the clinical manifestations of vascular dysfunction, the first step to cardiovascular disease and influencing vascular outcomes in the elderly. Accordingly, the preservation of endothelial function is thought to be an essential determinant of healthy aging. With special attention on the effects of aging on the endothelial function, this review is focused on the two main mechanisms of aging-related endothelial dysfunction: oxidative stress and inflammation. Aging vasculature generates an excess of the reactive oxygen species (ROS), superoxide and hydrogen peroxide, that compromise the vasodilatory activity of nitric oxide (NO) and facilitate the formation of the deleterious radical, peroxynitrite. Main sources of ROS are mitochondrial respiratory chain and NADPH oxidases, although NOS uncoupling could also account for ROS generation. In addition, reduced antioxidant response mediated by erythroid-2-related factor-2 (Nrf2) and downregulation of mitochondrial manganese superoxide dismutase (SOD2) contributes to the establishment of chronic oxidative stress in aged vessels. This is accompanied by a chronic low-grade inflammatory phenotype that participates in defective endothelial vasodilation. The redox-sensitive transcription factor, nuclear factor-κB (NF-κB), is upregulated in vascular cells from old subjects and drives a proinflammatory shift that feedbacks oxidative stress. This chronic NF-κB activation is contributed by increased angiotensin-II signaling and downregulated sirtuins and precludes adequate cellular response to acute ROS generation. Interventions targeted to recover endogenous antioxidant capacity and cellular stress response rather than exogenous antioxidants could reverse oxidative stress-inflammation vicious cycle in vascular aging. Lifestyle attitudes such as caloric restriction and exercise training appear as effective ways to overcome defective antioxidant response and inflammation, favoring successful vascular aging and decreasing the risk for cardiovascular disease.

Comparative effect of Piper betle, Chlorella vulgaris and tocotrienol-rich fraction on antioxidant enzymes activity in cellular ageing of human diploid fibroblasts

Background

Human diploid fibroblasts (HDFs) undergo a limited number of cellular divisions in culture and progressively reach a state of irreversible growth arrest, a process termed cellular ageing. Even though beneficial effects of Piper betle, Chlorella vulgaris and tocotrienol-rich fraction (TRF) have been reported, ongoing studies in relation to ageing is of interest to determine possible protective effects that may reverse the effect of ageing. The aim of this study was to evaluate the effect of P. betle, C. vulgaris and TRF in preventing cellular ageing of HDFs by determining the activity of antioxidant enzymes viz.; catalase, superoxide dismutase (SOD) and glutathione peroxidase.

Methods

Different passages of HDFs were treated with P. betle, C. vulgaris and TRF for 24 h prior to enzymes activity determination. Senescence-associated beta-galactosidase (SA β-gal) expression was assayed to validate cellular ageing.

Results

In cellular ageing of HDFs, catalase and glutathione peroxidase activities were reduced, but SOD activity was heightened during pre-senescence. P. betle exhibited the strongest antioxidant activity by reducing SA β-gal expression, catalase activities in all age groups, and SOD activity. TRF exhibited a strong antioxidant activity by reducing SA β-gal expression, and SOD activity in senescent HDFs. C. vulgaris extract managed to reduce SOD activity in senescent HDFs.

Conclusion

P. betle, C. vulgaris, and TRF have the potential as anti-ageing entities which compensated the role of antioxidant enzymes in cellular ageing of HDFs.

Chronic training increases blood oxidative damage but promotes health in elderly men

The objective of the present study was to investigate a large panel of oxidative stress biomarkers in long-term trained elderly men to analyse the effects of chronic training on an aged population. We collected blood samples from two groups of male volunteers older than 65 years who maintain a measure of functional independence: one group of sedentary subjects without a history of regular physical activity and the other of subjects who have sustained training, starting during middle age (mean training time=49 ± 8 years). We studied morbidity and polypharmacy, as well as haematological parameters including red cell count, haemoglobin concentration, haematocrit, mean corpuscular volume, red cell distribution width and several oxidative biomarkers including protein carbonyl content and lipid peroxidation in plasma and erythrocytes, red blood cell H2O2-induced haemolysis test, plasma total antioxidant activity and the main antioxidant enzymes of erythrocytes: superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glutathione-S-transferase. After adjusting for confounding factors, we observed an increase in all oxidative damage biomarkers in the plasma and erythrocytes of the long-term exercise group. However, we reported a decrease in the number of diseases per subject with statistical differences nearly significant (p=0.061), reduced intake of medications per subject and lower levels of red cell distribution width in the chronic exercise group. These results indicate that chronic exercise from middle age to old age increases oxidative damage; however, chronic exercise appears to be an effective strategy to attenuate the age-related decline in the elderly.

Treadmill exercise induces age-related changes in aversive memory, neuroinflammatory and epigenetic processes in the rat hippocampus

It has been described that exercise can modulate both inflammatory response and epigenetic modifications, although the effect of exercise on these parameters during the normal brain aging process yet remains poorly understood. Here, we investigated the effect of aging and treadmill exercise on inflammatory and epigenetic parameters specifically pro and anti-inflammatory cytokines levels, activation of NF-kB and histone H4 acetylation levels in hippocampus from Wistar rats. Additionally, we evaluated aversive memory through inhibitory avoidance task. Rats of 3 and 20 months of age were assigned to non-exercised (sedentary) and exercised (running daily for 20 min for 2 weeks) groups. The effect of daily forced exercise in the treadmill was assessed. The levels of inflammatory and epigenetic parameters were determined 1h, 18 h, 3 days or 7 days after the last training session of exercise. It was observed an age-related decline on aversive memory, as well as aged rats showed increased hippocampal levels of inflammatory markers, such as TNFα, IL1-β and NF-kB and decreased IL-4 levels, an anti-inflammatory cytokine. Moreover, lower levels of global histone H4 acetylation were also observed in hippocampi from aged rats. Interestingly, there was a significant correlation between the biochemical markers and the inhibitory avoidance test performance. The forced exercise protocol ameliorated aging-related memory decline, decreased pro-inflammatory markers and increased histone H4 acetylation levels in hippocampi 20-months-old rats, while increased acutely IL-4 levels in hippocampi from young adult rats. Together, these results suggest that an imbalance of inflammatory markers might be involved to the aging-related aversive memory impairment. Additionally, our exercise protocol may reverse aging-related memory decline through improving cytokine profile.

Dietary supplementation with N-acetyl cysteine, α-tocopherol and α-lipoic acid reduces the extent of oxidative stress and proinflammatory state in aged rat brain

The present study has attempted to understand how oxidative stress contributes to the development of proinflammatory state in the brain during aging. Three groups of rats have been used in this study: young (4-6 months, Group I), aged (22-24 months, Group II) and aged with dietary antioxidant supplementation (Group III). The antioxidants were given daily from 18 months onwards in the form of a combination of N-acetyl cysteine (50 mg/100 g body weight), α-lipoic acid (3 mg/100 g body weight), and α-tocopherol (1.5 mg/100 g body weight) till the animals were used for the experiments between 22 and 24 months. Several measurements have been made to evaluate the ROS (reactive oxygen species) production rate, the levels of proinflammatory cytokines (IL-1β, IL-6 and TNF-α) and the activation status of NF-κβ (p65 subunit) in brain of the three groups of rats under the study. Our results reveal that brain aging is accompanied with a significant increase in NADPH oxidase activity and mitochondrial ROS production, a distinct elevation of IL-1β, IL-6 and TNF-α levels along with increased nuclear translocation of NF-κβ (p65 subunit) and all these phenomena are partially but significantly prevented by the long-term dietary antioxidant treatment. The results imply that chronic dietary antioxidants by preventing oxidative stress and proinflammatory state may produce beneficial effects against multiple age-related deficits of the brain.

Tai chi diminishes oxidative stress in Mexican older adults

OBJECTIVE

To determine the effect of Tai Chi on oxidative stress in a population of elderly Mexican subjects.

DESIGN

It was carried out a quasi-experimental study with a sample of 55 healthy subjects randomly divided into two age-matched groups: (i) a control group with 23 subjects and (ii) an experimental group with 32 subjects. The experimental group received daily training in Tai Chi for 50 min.

MEASUREMENTS

It was measured before and after 6-month of exercise period: thiobarbituric acid reactive substances (TBARS), total antioxidant status (TAS), superoxide dismutase (SOD), and glutathione peroxidase (GPx).

RESULTS

It was found that the experimental group exhibited a statistically significant decrease in glucose levels, total cholesterol, low-density lipoprotein cholesterol (LDLC), and systolic blood pressure, as well as an increase in SOD and GPx activity and TAS compared with the control group (p < 0.05).

CONCLUSIONS

Our findings suggest that the daily practice of Tai Chi is useful for reducing OxS in healthy older adults.

Relationship of advanced oxidative protein products in human saliva and plasma: age- and gender-related changes and stability during storage

The blood levels of advanced oxidative protein products (AOPP) elevate in aging and age-related diseases. However, saliva AOPP in healthy humans have been unexplored. Thus, we investigated 143 Chinese healthy adults to assay age- and gender-related changes in saliva and plasma AOPP levels and the stability of saliva AOPP stored both at - 20°C and - 80°C. We found the mean AOPP levels in saliva and plasma of 119 subjects were 7.51 ± 3.20 and 28.31 ± 5.53 μmol/L (μM). An age-dependent increase was observed in both saliva and plasma AOPP levels. This increase was particularly significant in the elderly subjects compared with that in the young and middle-aged ones. A significant positive correlation among age, saliva and plasma AOPP levels was observed. No gender-dependent difference was observed in either saliva or plasma AOPP levels during the aging process. Furthermore, AOPP levels in the 24 saliva samples showed no significant change at every successive determination during 4 weeks at - 80°C, whereas those levels significantly increased after 7 days of storage at - 20°C. These results indicate the feasibility to screen aging biochemical indicators using saliva AOPP as an alternative to blood AOPP. Saliva AOPP samples are suitable to be stored at - 80°C.

Mechanisms involved in the aging-induced vascular dysfunction

Vascular aging is a key process determining health status of aged population. Aging is an independent cardiovascular risk factor associated to an impairment of endothelial function, which is a very early and important event leading to cardiovascular disease. Vascular aging, formerly being considered an immutable and inexorable risk factor, is now viewed as a target process for intervention in order to achieve a healthier old age. A further knowledge of the mechanisms underlying the age-related vascular dysfunction is required to design an adequate therapeutic strategy to prevent or restore this impairment of vascular functionality. Among the proposed mechanisms that contribute to age-dependent endothelial dysfunction, this review is focused on the following aspects occurring into the vascular wall: (1) the reduction of nitric oxide (NO) bioavailability, caused by diminished NO synthesis and/or by augmented NO scavenging due to oxidative stress, leading to peroxynitrite formation (ONOO(-)); (2) the possible sources involved in the enhancement of oxidative stress; (3) the increased activity of vasoconstrictor factors; and (4) the development of a low-grade pro-inflammatory environment. Synergisms and interactions between all these pathways are also analyzed. Finally, a brief summary of some cellular mechanisms related to endothelial cell senescence (including telomere and telomerase, stress-induced senescence, as well as sirtuins) are implemented, as they are likely involved in the age-dependent endothelial dysfunction, as well as in the lower vascular repairing capacity observed in the elderly. Prevention or reversion of those mechanisms leading to endothelial dysfunction through life style modifications or pharmacological interventions could markedly improve cardiovascular health in older people.

Mechanism of Ang II involvement in activation of NF-κB through phosphorylation of p65 during aging

Angiotensin II (Ang II), a major effector of the renin-angiotensin system, is now recognized as a pro-inflammatory mediator. This Ang II signaling, which causes transcription of pro-inflammatory genes, is regulated through nuclear factor-κB (NF-κB). At present, the molecular mechanisms underlying the effect of aging on Ang II signaling and NF-κB activation are not fully understood. The purpose of this study was to document altered molecular events involved in age-related changes in Ang II signaling and NF-κB activation. Experimentations were carried out using kidney tissues from Fischer 344 rats at 6, 12, 18, and 24 months of age, and the rat endothelial cell line, YPEN-1 for the detailed molecular work. Results show that increases in Ang II and Ang II type 1 receptor during aging were accompanied by the generation of reactive species. Increased Ang II activated NF-κB by phosphorylating IκBα and p65. Increased phosphorylation of p65 at Ser 536 was mediated by the enhanced phosphorylation of IκB kinase αβ, while phosphorylation site Ser 276 of p65 was mediated by upregulated mitogen-activated and stress-activated protein kinase-1. These altered molecular events in aged animals were partly verified by experiments using YPEN-1 cells. Collectively, our findings provide molecular insights into the pro-inflammatory actions of Ang II, actions that influence the phosphorylation of p65-mediated NF-κB activation during aging. Our study demonstrates the age-related pleiotropic nature of the physiologically important Ang II can change into a deleterious culprit that contributes to an increased incidence of many chronic diseases such as atherosclerosis, diabetes, and dementia.

Reactive oxygen species in skeletal muscle signaling

Generation of reactive oxygen species (ROS) is a ubiquitous phenomenon in eukaryotic cells' life. Up to the 1990s of the past century, ROS have been solely considered as toxic species resulting in oxidative stress, pathogenesis and aging. However, there is now clear evidence that ROS are not merely toxic species but also-within certain concentrations-useful signaling molecules regulating physiological processes. During intense skeletal muscle contractile activity myotubes' mitochondria generate high ROS flows: this renders skeletal muscle a tissue where ROS hold a particular relevance. According to their hormetic nature, in muscles ROS may trigger different signaling pathways leading to diverging responses, from adaptation to cell death. Whether a "positive" or "negative" response will prevail depends on many variables such as, among others, the site of ROS production, the persistence of ROS flow or target cells' antioxidant status. In this light, a specific threshold of physiological ROS concentrations above which ROS exert negative, toxic effects is hard to determine, and the concept of "physiologically compatible" levels of ROS would better fit with such a dynamic scenario. In this review these concepts will be discussed along with the most relevant signaling pathways triggered and/or affected by ROS in skeletal muscle.

Combined effect of antioxidant supplementation and resistance training on oxidative stress markers, muscle and body composition in an elderly population

This study was aimed to examine the effect of vitamin C/E intake alone or combined with resistance training on antioxidant/pro-oxidant status, muscle strength and body composition in an elderly population. Fifty-seven men and women with a mean age of 65.6 ± 3.8 years were recruited and randomized in a double-blind fashion into four groups: control-placebo; resistance training (RT); vitamins C/E supplementation (AS); AS+RT. Oxidative stress status and metabolic and lipid profiles were determined at baseline and after six months. Fat-free mass and fat mass measured by DXA were similar at baseline for all groups. At six month, there was a significant difference among the groups as a function of vitamin E supplementation. Moreover, although there was no effect on pro-oxidative parameters, a significant effect on body composition was noted, but no difference was noted on strength gain. The combination of RT+AS had a positive effect on the plasma antioxidant profile but not on the pro-oxidant status.

Effects of the association of aging and obesity on lipids, lipoproteins and oxidative stress biomarkers: a comparison of older with young men

In this study, plasma lipids, lipoproteins and markers of oxidant/antioxidant status were investigated in young (n = 45) and older (n = 40) obese men and compared to those in young (n = 65) and older (n = 55) normal weight controls. The purpose was to determine whether obesity exacerbates or not lipid, lipoprotein abnormalities and oxidative stress in older men. Our findings showed that all obese patients had increased plasma triglyceride, cholesterol, LDL-cholesterol, -triglyceride and HDL-triglyceride levels concentrations compared to controls (P < 0.01). However, the younger obese men had relatively larger and accentuated changes in plasma lipids and lipoproteins than the older patients. Additionally, total antioxidant capacity (ORAC), vitamins C and E were lower while hydroperoxides and carbonyl proteins were higher in young and older obese patients compared to their respective controls (P < 0.001). Erythrocyte antioxidant SOD and catalase activities were enhanced in obese young patients, but reduced in obese older men. Glutathione peroxidase activity was low in obesity irrespective of age. In multiple regression analysis, BMI significantly predicted total cholesterol, LDL-C, LDL-TG and HDL-TG (P < 0.0001). These relationships were not modified by age. BMI alone was a not a significant predictor for ORAC, vitamins C, E, catalase and Glutathione peroxidase. However, the interaction BMI-age significantly predicted these parameters and explained 28-45% of their changes. BMI was a significant predictor of SOD, carbonyl proteins and hydroperoxides. This effect became more significant (P < 0.0001) and worsened with BMI-age interaction. In conclusion, lipoprotein metabolism and oxidant/antioxidant status are altered in obesity irrespective of age. However, obesity-related lipid and lipoprotein alterations were attenuated while oxidative stress was aggravated in older adults.

Physiopathology of radiation-induced neurotoxicity

Ionizing irradiation for the treatment of malignant brain tumors has associated with it a risk of inducing serious morphologic and functional deficits. While obvious tissue damage generally occurs after relatively high radiation doses, cognitive impairment can be seen after lower exposures. The mechanisms responsible for cognitive injury are not well understood, but may involve neurogenesis, a process that is affected by microenvironmental factors including oxidative stress and inflammation. In addition, damage to neurons, either directly or through environmental influences may have a profound impact on cognition. The relationships between cellular response, environmental factors and behavior are complex and difficult to study. However, understanding such issues should provide critical information relevant to the development of strategies and approaches to ameliorate or treat radiation-induced injuries that are associated with behavioral performance.

Accelerated vascular aging in CuZnSOD-deficient mice: impact on EPC function and reparative neovascularization

Objective

Aging is associated with increased oxidative stress levels and impaired neovascularization following ischemia. CuZnSOD has an important role to limit oxidative stress in the vasculature. Here we investigated the role of CuZnSOD for the modulation of ischemia-induced neovascularisation during aging.

Methods and Results

Hindlimb ischemia was surgically induced in young (2- month-old) or older (8-month-old) wild type (WT) and CuZnSOD^−/− mice. We found that blood flow recovery after ischemia and vascular density in ischemic muscles were significantly reduced in older compared to young WT mice. Both in young and older mice, CuZnSOD deficiency led to a further reduction of neovascularization. Accordingly, the resulting neovascularisation potential in a young CuZnSOD^−/− mouse was similar to that of an older WT mouse. Oxidative stress levels were also increased to similar levels in the ischemic muscles of young CuZnSOD^−/− and older WT mice. To identify potential mechanisms involved, we investigated the effect of aging and CuZnSOD deficiency on the number and the function of endothelial progenitor cells (EPCs). Both aging and CuZnSOD deficiency were associated with reduced number of bone marrow and peripheral EPCs. The effect of moderate aging alone on specific functional activities of EPCs (migration, integration into tubules) was modest. However, CuZnSOD deficiency was associated with severe age-dependent defects in EPC functional activities.

Conclusions

CuZnSOD deficiency is associated with accelerated vascular aging and impaired ischemia-induced neovascularization. Our results suggest that in the context of aging, CuZnSOD has an essential role to protect against excessive oxidative stress in ischemic tissues and preserve the function of EPCs.

Molecular inflammation as an underlying mechanism of the aging process and age-related diseases

Aging is a biological process characterized by time-dependent functional declines that are influenced by changes in redox status and by oxidative stress-induced inflammatory reactions. An organism's pro-inflammatory status may underlie the aging process and age-related diseases. In this review, we explore the molecular basis of low-grade, unresolved, subclinical inflammation as a major risk factor for exacerbating the aging process and age-related diseases. We focus on the redox-sensitive transcription factors, NF-κB and FOXO, which play essential roles in the expression of pro-inflammatory mediators and anti-oxidant enzymes, respectively. Major players in molecular inflammation are discussed with respect to the age-related up-regulation of pro-inflammatory cytokines and adhesion molecules, cyclo-oxygenase-2, lipoxygenase, and inducible nitric oxide synthase. The molecular inflammation hypothesis proposed by our laboratory is briefly described to give further molecular insights into the intricate interplay among redox balance, pro-inflammatory gene activation, and chronic age-related inflammatory diseases. The final section discusses calorie restriction as an aging-retarding intervention that also exhibits extraordinarily effective anti-inflammatory activity by modulating GSH redox, NF-κB, SIRT1, PPARs, and FOXOs.

Neuroprotective effects of Abacopterin E from Abacopteris penangiana against oxidative stress-induced neurotoxicity

AIM OF THE STUDY

Abacopterin E (AE) was isolated from Abacopteris penangiana (Hook.) Ching. This study was to elucidate its neuroprotective effects against hydrogen peroxide (H(2)O(2)) induced oxidative damage in PC12 cells and d-galactose (d-Gal) induced neurotoxicity in mice brain.

MATERIALS AND METHODS

In vitro, the protective effect of AE against H(2)O(2)-induced oxidative damage in the PC12 was investigated by the method of MTT (3,(4,5-dimethylthiazole-2-yl)2,5-diphenyl-tetrazolium bromide). In vivo, the protective effect of AE against d-Gal-induced neurotoxicity in mice was studied. The mice in the model group and the AE treatment groups were injected with the d-Gal 150 mg/(kg d) for 7 weeks while the mice in the control group were injected with the same volume of saline (0.9%). From the sixth week, the treatment groups were subcutaneously injected 4 or 8 mg/(kg d) of AE. In order to explore the potential mechanism of AE's action, the mice were assessed by behavioral and electrophysiological tests at the end of the administration. Then the mice brain tissues were measured for the levels of superoxide dismutases (SOD), glutathione peroxidase (GSH-Px), and malondialdehyde (MDA).

RESULTS

This study showed that AE lowered the H(2)O(2)-induced cytotoxicity, and AE significantly improved the learning and memory ability in behavioral performance. The biochemical examination revealed that AE restored the activities of SOD and GSH-Px, and attenuated the increase of MDA. Moreover, the electrophysiological analysis evidently showed that AE ameliorated the long-term potentiation (LTP).

CONCLUSIONS

These results suggested that AE had neuroprotective effects, and its beneficial effects may be linked with inhibiting the generation of free radical and enhancing the activities of endogenous antioxidant enzymes.

Mitophagy in yeast: actors and physiological roles

Mitochondria are essential for oxidative energy production in aerobic eukaryotic cells, where they are also required for multiple biosynthetic pathways to take place. Mitochondria also monitor and evaluate complex information from the environment and intracellular milieu, including the presence or absence of growth factors, oxygen, reactive oxygen species, and DNA damage. It follows that disturbances of the integrity of mitochondrial function lead to the disruption of cell function, expressed as disease, aging, or cell death. It has been assumed that the degradation of damaged mitochondria by an autophagy-related pathway specific to mitochondria (mitophagy), recently found to be strictly regulated, is a fundamental process essential for cell homeostasis. Until now, the main role of mitophagy has been tentatively defined as a 'house-cleaning' pathway that allows to eliminate altered mitochondria, but mitophagy may also play a role in the adaptation of the number and quality of mitochondria to new environmental conditions. In yeast, recent data defined two categories of mitophagy actors: ones constitutively required for mitophagy and those with mitophagy-regulatory functions. Situations were also uncovered in normal physiology in which cells utilize mitophagy to eliminate damaged, dysfunctional, and superfluous mitochondria to adjust to changing physiological demands.

Somatic cell nuclear reprogramming of mouse oocytes endures beyond reproductive decline

The mammalian oocyte has the unique feature of supporting fertilization and normal development, while capable of reprogramming nuclei of somatic cells toward pluripotency, and occasionally even totipotency. While oocyte quality is known to decay with somatic aging, it is not a given that different biological functions decay concurrently. In this study, we tested whether oocyte's reprogramming ability decreases with aging. We show that oocytes isolated from mice aged beyond the usual reproductive age (climacteric) yield ooplasts that retain reprogramming capacity after somatic nuclear transfer (SCNT), giving rise to higher blastocysts rates compared to young donors ooplasts. Despite the differences in transcriptome between climacteric and young ooplasts, gene expression profiles of SCNT blastocysts were very similar. Importantly, embryonic stem cell lines with capacity to differentiate into tissues from all germ layers were derived from SCNT blastocysts obtained from climacteric ooplasts. Although apoptosis-related genes were down-regulated in climacteric ooplasts, and reprogramming by transcription factors (direct-induced pluripotency) benefits from the inhibition of p53-mediated apoptosis, reprogramming capacity of young ooplasts was not improved by blocking p53. However, more outgrowths were derived from SCNT blastocysts developed in the presence of a p53 inhibitor, indicating a beneficial effect on trophectoderm function. Results strongly suggest that oocyte-induced reprogramming outcome is determined by the availability and balance of intrinsic pro- and anti-reprogramming factors tightly regulated and even improved throughout aging, leading to the proposal that oocytes can still be a resource for somatic reprogramming when they cease to be considered safe for sexual reproduction.

Mesenchymal stem cells: biological properties and clinical applications

IMPORTANCE OF THE FIELD

In the last decade, knowledge of mesenchymal stem cells (MSCs) has evolved rapidly; their immunomodulatory properties and paracrine interactions with specific cell types in damaged tissues and promising results in some clinical applications have made these cells an attractive option for the treatment of certain diseases.

AREAS COVERED IN THIS REVIEW

We present some relevant methodological issues and biological properties of MSCs, as well as clinical applications of MSC therapies with particular emphasis in the treatment of graft versus host disease (GVHD), complex perianal fistula and refractory metastatic neuroblastoma. Other topical aspects relevant to the application of cellular therapies such as biosafety studies and cellular production of MSCs are also discussed in this review.

WHAT THE READER WILL GAIN

The growing optimism regarding MSCs research is based on the promising results obtained in in vitro and in vivo studies. The rapid translational research with MSCs necessitated standardization of methodology and terminology and greater focus on other aspects such as biosafety and cellular production, especially for clinical use of MSCs.

TAKE HOME MESSAGE

Much has been learned about the biology and applications of MSCs and much remains to be learned.