Oxidative stress and aging

2,2'- Bipyridine Derivatives Exert Anticancer Effects by Inducing Apoptosis in Hepatocellular Carcinoma (HepG2) Cells

Purpose

To elucidate the therapeutic potential of 2,2'-bipyridine derivatives [NPS (1-6)] on hepatocellular carcinoma HepG2 cells.

Methods

The effects on cell survival, colony formation, cellular and nuclear morphology, generation of reactive oxygen species (ROS), change in the integrity of mitochondrial membrane potential (MMP), and apoptosis were investigated. Additionally, docking studies were conducted to analyze and elucidate the interactions between the derivatives and AKT and BRAF proteins.

Results

NPS derivatives (1, 2, 5 and 6) significantly impaired cell viability of HepG2 cell lines at nanogram range concentrations - 72.11 ng/mL, 154.42 ng/mL, 71.78 ng/mL, and 71.43 ng/mL, while other derivatives were also effective at concentrations below 1 µg/mL. These compounds reduced the colony formation capacity of HepG2 cells in a dose-dependent manner following treatment. Mechanistic studies revealed that these derivatives induce reactive oxygen species (ROS) accumulation and cause mitochondrial membrane depolarization, ultimately triggering apoptosis in HepG2 cells. In the presence of these derivatives, cells demonstrated that 75% of cells underwent apoptosis, compared to 25% in the control group. Additionally, there was a marked increase in mitochondrial depolarization (95% cells) and a threefold rise in ROS levels compared to the controls. Docking studies revealed interactions between the derivatives and the signaling proteins AKT (PDB ID: 6HHF) and BRAF (PDB ID: 8C7Y) with binding affinities ranging from -7.10 to -9.91, highlighting their pivotal role in targeting key players in hepatocellular carcinoma progression.

Conclusion

The findings of this study underscore the therapeutic potential of these derivatives against HepG2 cells and offer valuable insights for further experimental validation of their efficacy as inhibitors targeting AKT or BRAF signaling pathways.

Altered glucose kinetics occurs with aging: a new outlook on metabolic flexibility

Our purpose was to determine how age affects metabolic flexibility and underlying glucose kinetics in healthy young and older adults. Therefore, glucose and lactate tracers along with pulmonary gas exchange data were used to determine glucose kinetics and respiratory exchange ratios [RER = carbon dioxide production (V̇co2)/oxygen consumption (V̇o2)] during a 2-h 75-g oral glucose tolerance test (OGTT). After an 12-h overnight fast, 28 participants, 15 young (21-35 yr; 7 men and 8 women) and 13 older (60-80 yr; 7 men and 6 women), received venous primed-continuous infusions of [6,6-2H]glucose and [3-13C]lactate with a [Formula: see text] bolus. After a 90-min metabolic stabilization and tracer equilibration period, volunteers underwent an OGTT. Arterialized glucose concentrations ([glucose]) started to rise 15 min post glucose consumption, peaked at 60 min, and remained elevated. As assessed by rates of appearance (Ra) and disposal (Rd) and metabolic clearance rate (MCR), glucose kinetics were suppressed in older compared to young individuals. As well, unlike in young individuals, fractional gluconeogenesis (fGNG) remained elevated in the older population after the oral glucose challenge. Finally, there were no differences in 12-h fasting baseline or peak RER values following an oral glucose challenge in older compared to young men and women, making RER an incomplete measure of metabolic flexibility in the volunteers we evaluated. Our study revealed that glucose kinetics are significantly altered in a healthy aged population after a glucose challenge. Furthermore, those physiological deficits are not detected from changes in RER during an OGTT.NEW & NOTEWORTHY To determine metabolic flexibility in response to an OGTT, we studied healthy young and older men and women to determine glucose kinetics and changes in RER. Compared to young subjects, glucose kinetics were suppressed in older healthy individuals during an OGTT. Surprisingly, the age-related changes in glucose flux were not reflected in RER measurements; thus, RER measurements do not give a complete view of metabolic flexibility in healthy individuals.

The effect of a rotating magnetic field on the antioxidant system in healthy volunteers - preliminary study

Oxidative stress is characterized by an excessive concentration of reactive oxygen species (ROS) resulting from a disturbance in the balance between ROS production and their removal by antioxidant systems (SOD, CAT, GPx). Prolonged and intense oxidative stress can cause various forms of damage to cells, which markers are total antioxidant capacity (TAC), reactive oxygen species modulator (ROMO1), and malondialdehyde (MDA). It has been demonstrated that magnetic fields can positively affect human health, for example, by reducing oxidative stress. Determination of the effect of a rotating magnetic field (RMF) on the activity/concentration of selected oxidative stress markers. A group of 30 healthy volunteers (15 women and 15 men) (mean age 24.8 ± 5.1) in the study classified into the following groups: internal control group (CG);1 h 25 Hz (samples placed in the field for one hour at 25 Hz); 3 h 25 Hz (samples placed in the field for 3 h at 25 Hz), the 1 h 50 Hz group ( placed in RMF for an hour at 50 Hz), and a group of 3 h 50 Hz (samples placed in the field for 3 h at 50 Hz). Serum samples were collected in K2EDTA tubes.. The magnetic induction value obtained for RMF is 37.06 mT and 42.64 mT.Activity/concentration of selected oxidative stress markers was analyzed by ELISA. The influence of an RMF on the activity/concentration of SOD, MDA, TAC, and ROMO1 was demonstrated (p < 0.001; p = 0.0013; p < 0.001; p = 0.003). The RFM can reduce oxidative stress, as evidenced by higher SOD and CAT activities in the CG than in samples placed in the RFM. Prolonged exposure to the RFM at 50 Hz increased the TAC level, indicating an intensification of oxidative stress in these samples. The optimal conditions for staying in the RFM (reducing oxidative stress) are 1 h 50 Hz for SOD and MDA; 3 h 25 Hz for CAT and TAC. In the case of ROMO1, it is stated that 1 h 25 Hz are the optimal conditions for no increased production of ROS.

Effect of sulfate on the osmoregulatory and physio-biochemical responses of GIFT (Oreochromis niloticus) juveniles reared in potassium-deficient medium saline waters

The inland saline waters were continuously observed to have low potassium concentrations compared to their seawater counterpart of the same salinity. We hypothesize that the toxic effect of sulfate may manifest in low potassium saline (LPSW) waters compared to brackish water of the same salinity. Thus, LC50 trials were performed in GIFT (genetically improved farmed tilapia) fry (0.5 ± 0.02 g) to determine the acute sulfate toxicity in freshwater (FW, 0.5 g L-1), artificial seawater (ASW, 10 g L-1), and LPSW (10 g L-1). The median lethal concentrations (96h LC50) of sulfate ion in FW, LPSW, and ASW for the GIFT were 5.30 g L-1, 2.56 g L-1, and 2.98 g L-1, respectively. A second experiment was conducted for 21 days, exposing fish to a sub-lethal level of sulfate ion (SO42-) concentration (1000 mg L-1, one-fifth of FW LC50) with different types of waters (FW, freshwater, 0.5 g L-1; ASW, artificial seawater, 10 g L-1; LPSW, low potassium saline water, 10 g L-1) with and without sulfate inclusion to constitute the treatments as follows, (FW, FW + SO4, ASW, ASW + SO4, LPSW, LPSW + SO4). The effect of sulfate on GIFT reared in sulfate-rich potassium-deficient medium saline water was evaluated by focusing on the hematological adjustments, stress-induced oxidative damage, and osmoregulatory imbalances. The survival was not altered due to the sulfate concentration and K+ deficiency; however, there were significant changes in branchial NKA (Na+/K+-ATPase) activity and osmolality. The increase in NKA was highest in LPSW treatment, suggesting that internal ionic imbalance was triggered due to an interactive effect of sulfate and K+ deficiency. The cortisol levels showed a pronounced increase due to sulfate inclusion irrespective of K+ deficiency. The antioxidant enzymes, i.e., SOD (superoxide dismutase), catalase, GST (glutathione-S-transferase), and GPX (glutathione peroxidase), reflected a similar pattern of increment in the gills and liver of the LPSW + SO4 groups, suggesting a poor antioxidant status of the exposed group. The hepatic peroxidation status, i.e. TBARS (thiobarbituric acid reactive substances), and the peroxide values were enhanced due to both K+ deficiency and sulfate inclusion, suggesting a possible lipid peroxidation in the liver due to handling the excess sulfate anion concentration. The hematological parameters, including haemoglobin, total erythrocyte count, and hematocrit level, reduced significantly in the LPSW + SO4 group, indicating a reduced blood oxygen capacity due to the sulfate exposure and water potassium deficiency. The hepatic acetylcholine esterase activity was suppressed in all the treatments with sulfate inclusion, while the highest suppression was observed in the LPSW + SO4 group. Thus, it is concluded that sulfate-induced physiological imbalances manifest more in potassium-deficient water, indicating that environmental sulfate is more detrimental to inland saline water than freshwater or brackish water of the same salinity.

A newly identified small tRNA fragment reveals the regulation of different wool types and oxidative stress in lambs

Novel small RNAs derived from tRNAs are continuously identified, however, their biological functions are rarely reported. Here, we accidentally found the reads peak at 32nt during statistical analysis on the miRNA-seq data of lamb skin tissue, and found that it was related to the wool type of lambs. This 32nt peak was composed of small tRNA fragments. The main component sequence of this peak was a novel small tRNA derived from Glycyl tRNA (tRNAGly), the expression level of tRNAGly-derived tRNA fragments (tRFGly) was 5.77 folds higher in the coarse wool lambs than that in the fine wool lambs. However, in contrast, the expression of tRNAGly in the skin of fine wool lambs is 6.28 folds more than that in coarse wool lambs. tRNAGly promoted the synthesis of high glycine protein including KAP6 in fine wool lamb skin. These proteins were reported as the major genes for fine curly wool. Integrative analysis of target gene prediction, proteomics and metabolomics results revealed that tRFGly reduced the level of reactive oxygen species (ROS) in the skin of coarse wool lambs by targeted inhibition of the Metabolic signal and the corresponding Glutathione metabolic pathway, on the contrary, the level of oxidative stress in the skin of fine wool lambs was significantly higher. This study revealed for the first time the relationship between tRNAGly and its derived tRFGly and animal traits. tRFGly has the function of targeting and regulating protein synthesis. At the same time, tRFGly can reduce the expression of its resource complete tRNA, thereby reducing its ability to transport specific amino acid and affecting the expression of corresponding proteins.

Naringenin Induces HepG2 Cell Apoptosis via ROS-Mediated JAK-2/STAT-3 Signaling Pathways

Hepatocarcinoma is one of the most prevalent digestive system tumors worldwide and lacks effective therapy. Recently, naringenin has been isolated from some citrus fruits, and its anticancer effects have been tested. However, the molecular mechanisms of naringenin and the potential implications of oxidative stress in naringenin-induced cytotoxicity in HepG2 cells remain elusive. Based on the above, the present study examined the effect of naringenin on the cytotoxic and anticancer mechanisms of HepG2 cells. Naringenin-induced HepG2 cell apoptosis was confirmed via the accumulation of the sub-G1 cell population, phosphatidylserine exposure, mitochondrial transmembrane potential loss, DNA fragmentation, caspase-3 activation, and caspase-9 activation. Furthermore, naringenin enhanced cytotoxic effects on HepG2 cells and triggered intracellular reactive oxygen species; the signaling pathways of JAK-2/STAT-3 were inhibited, and caspase-3 was activated to advance cell apoptosis. These results suggest that naringenin plays an important role in inducing apoptosis in HepG2 cells and that naringenin may be a promising candidate for cancer therapy.

Decreases of ethanolamine plasmalogen and phosphatidylcholine in erythrocyte are a common phenomenon in Alzheimer's, Parkinson's, and coronary artery diseases

Decreased plasma levels of plasmalogens in neurodegenerative diseases have been watched with interest. We previously reported the decreases of erythrocyte ethanolamine plasmalogen (PlsPE) of blood not only in Alzheimer's disease (AD) and Parkinson's disease (PD), but also in coronary artery disease (CAD). In the present study, by using the same high-performance liquid chromatography (HPLC) method, we investigated the pattern of changes in the phospholipid composition of erythrocyte membrane in AD, PD and CAD compared with healthy individuals. The common patten of changes among them was as follows: The decrease of erythrocyte PlsPE was accompanied by a decrease of phosphatidylcholine although phosphatidylethanolamine remained unchanged. The decreases of PlsPE and phosphatidylcholine were replaced by an increase of sphingomyelin (SM) in the total phospholipids. The dissociated change between PlsPE and phosphatidylethanolamine (PE) may be caused by the differences in molecular structure or in location in the cell membrane. Such special changes provide another piece of biochemical evidence that these different diseases are caused by identical pathological mechanism, suggesting potential biomarkers for these chronic diseases due to aging.

Modulation of 1,2-Dicarbonyl Compounds in Postprandial Responses Mediated by Food Bioactive Components and Mediterranean Diet

Glycoxidative stress with the consequent generation of advanced glycation end products has been implied in the etiology of numerous non-communicable chronic diseases. During the postprandial state, the levels of 1,2-dicarbonyl compounds can increase, depending on numerous factors, including characteristics of the subjects mainly related to glucose metabolism disorders and nutritional status, as well as properties related to the chemical composition of meals, including macronutrient composition and the presence of dietary bioactive molecules and macromolecules. In this review, we examine the chemical, biochemical, and physiological pathways that contribute to postprandial generation of 1,2-dicarbonyl compounds. The modulation of postprandial 1,2-dicarbonyl compounds is discussed in terms of biochemical pathways regulating the levels of these compounds, as well as the effect of phenolic compounds, dietary fiber, and dietary patterns, such as Mediterranean and Western diets.

SOCIAL ENVIRONMENT IMPROVES THE CYTOKINE PROFILE AND LYMPHOPROLIFERATIVE RESPONSE IN CHRONOLOGICALLY OLD AND PREMATURELY AGING MICE

Among the age-associated changes in the immune system, the most evident is the decrease in proliferative responses of lymphocytes to mitogenic stimuli, which is accompanied by the loss of cytokine network homeostasis. Chronic low-grade inflammatory stress, termed as sterile inflammation, is also observed during aging. In chronologically and prematurely aging mice, cohabitation with adult animals for two months favored improvements in several immune functions. This study aimed to determine whether cohabitation could restore several cytokine networks, improve lymphoproliferative responses to mitogens, and diminish sterile inflammation. Chronologically old mice (76±4 weeks) and prematurely aging mice (33±4 weeks) (PAM and TH-HZ) were cohabited with adults (without premature aging) for two months. Subsequently, lymphoproliferation in both basal (unstimulated) conditions and in the presence of mitogenic stimuli lipopolysaccharide A (LPS) or concanavalin A (ConA) was analyzed in cultures of peritoneal leukocytes for 48h. Cytokine secretions (IL-1β, TNF-α, IL-6, IL-10, and IL-17) in these cultures were also evaluated. The results showed that cohabitation restored the levels of these cytokines in old and prematurely aging mice and improved the subsequent lymphoproliferative responses. In addition, this social strategy diminished sterile inflammation and decreased inflammatory stress in unstimulated conditions. Therefore, this strategy seems to be capable of restoring the relevant immune function of lymphocytes and reducing the inflammatory stress, which are the improvements required for an adequate immune response.

The Key Role of Peroxisomes in Follicular Growth, Oocyte Maturation, Ovulation, and Steroid Biosynthesis

The absence of peroxisomes can cause disease in the human reproductive system, including the ovaries. The available peroxisomal gene-knockout female mouse models, which exhibit pathological changes in the ovary and reduced fertility, are listed in this review. Our review article provides the first systematic presentation of peroxisomal regulation and its possible functions in the ovary. Our immunofluorescence results reveal that peroxisomes are present in all cell types in the ovary; however, peroxisomes exhibit different numerical abundances and strong heterogeneity in their protein composition among distinct ovarian cell types. The peroxisomal compartment is strongly altered during follicular development and during oocyte maturation, which suggests that peroxisomes play protective roles in oocytes against oxidative stress and lipotoxicity during ovulation and in the survival of oocytes before conception. In addition, the peroxisomal compartment is involved in steroid synthesis, and peroxisomal dysfunction leads to disorder in the sexual hormone production process. However, an understanding of the cellular and molecular mechanisms underlying these physiological and pathological processes is lacking. To date, no effective treatment for peroxisome-related disease has been developed, and only supportive methods are available. Thus, further investigation is needed to resolve peroxisome deficiency in the ovary and eventually promote female fertility.

Association of sudden sensorineural hearing loss with increased risk of insomnia: a nationwide population-based cohort study

STUDY OBJECTIVES

To evaluate the risk of insomnia in patients with sudden sensorineural hearing loss (SSNHL).

METHODS

A retrospective propensity score-matched cohort study was conducted using a nationwide representative sample from the National Sample Cohort 2002-2013 data from the Korea National Health Insurance Service. The SSNHL group (n = 631) included patients diagnosed with SSNHL between January 2002 and December 2005. The comparison group (four controls for every patient with SSNHL, n = 2,524) was selected using propensity score matching, according to sociodemographic factors and the year of enrollment. Each patient was monitored until 2013. Survival analysis, log-rank test, and Cox proportional hazards regression models were used to calculate the incidence, survival rate, and hazard ratio (HR) of insomnia for each group.

RESULTS

Among the 3155 individuals included in the study population (male, 48.6%), the overall incidence of insomnia during the 11-year follow-up was 1.4-fold higher in the SSNHL group than in the non-SSNHL group (106.3 vs. 138.3 per 10,000 person-years; adjusted HR 1.38; 95% confidence interval [CI] 1.08-1.78). Moreover, the adjusted HRs for developing insomnia (depression, 3.33 [95% CI, 2.22-5.01]; anxiety, 1.78 [95% CI, 1.27-2.53]; tinnitus, 1.56 [95% CI, 1.2-2.03]; dizziness, 1.76 [95% CI, 1.27-2.44]) were higher in patients with comorbidities.

CONCLUSIONS

This observational study suggests that SSNHL is associated with an increased incidence of insomnia. Specifically, findings from this study show that patients with tinnitus, depression, anxiety and dizziness had a higher risk of developing insomnia than those without tinnitus, depression, anxiety, and dizziness.

An essay on the nominal vs. real definitions of aging

In the current literature, the definitions of aging range from relying on certain sets of distinctive features at the molecular, organismal, populational and/or even evolutional levels/scales to declaring it a treatable disease and, moreover, to treating aging as a mental construct rather than a natural phenomenon. One reason of such a mess may be that it is common in the natural sciences to disregard philosophy of science where several categories of definitions are recognized, among which the nominal are less, and the so-called real ones are more appropriate in scientific contexts. E.g., water is, by its nominal definition, a liquid having certain observable features and, by its real definition, a specific combination (or a product of interaction) of hydrogen and oxygen atoms. Noteworthy, the real definition is senseless for people ignorant of atoms. Likewise, the nominal definition of aging as a set of observable features should be supplemented, if not replaced, with its real definition. The latter is suggested here to imply that aging is the product of chemical interactions between the rapidly turning-over free metabolites and the slowly turning-over metabolites incorporated in macromolecules involved in metabolic control. The phenomenon defined in this way emerged concomitantly with metabolic pathways controlled by enzymes coded for by information-storing macromolecules and is inevitable wherever such conditions coincide. Aging research, thus, is concerned with the elucidation of the pathways and mechanisms that link aging defined as above to its hallmarks and manifestations, including those comprised by its nominal definitions. Esoteric as it may seem, defining aging is important for deciding whether aging is what should be declared as the target of interventions aimed at increasing human life and health spans.

Sex differences in early transcriptomic responses to oxidative stress in the copepod Tigriopus californicus

Background

Patterns of gene expression can be dramatically different between males and females of the same species, in part due to genes on sex chromosomes. Here we test for sex differences in early transcriptomic response to oxidative stress in a species which lacks heteromorphic sex chromosomes, the copepod Tigriopus californicus.

Results

Male and female individuals were separately exposed to control conditions and pro-oxidant conditions (hydrogen peroxide and paraquat) for periods of 3 hours and 6 hours. Variance partitioning showed the greatest expression variance among individuals, highlighting the important information that can be obscured by the common practice of pooling individuals. Gene expression variance between sexes was greater than that among treatments, showing the profound effect of sex even when males and females share the same genome. Males exhibited a larger response to both pro-oxidants, differentially expressing more than four times as many genes, including up-regulation of more antioxidant genes, heat shock proteins and protease genes. While females differentially expressed fewer genes, the magnitudes of fold change were generally greater, indicating a more targeted response. Although females shared a smaller fraction of differentially expressed genes between stressors and time points, expression patterns of antioxidant and protease genes were more similar between stressors and more GO terms were shared between time points.

Conclusions

Early transcriptomic responses to the pro-oxidants H₂O₂ and paraquat in copepods revealed substantial variation among individuals and between sexes. The finding of such profound sex differences in oxidative stress response, even in the absence of sex chromosomes, highlights the importance of studying both sexes and the potential for developing sex-specific strategies to promote optimal health and aging in humans.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-020-07179-5.

Mitochondria and cellular redox state on the route from ageing to Alzheimer's disease

Several theories have been postulated, trying to explain why and how living organisms age. Despite some controversies and still huge open questions, a growing body of evidence suggest alterations of mitochondrial functionality and redox-homeostasis occur during the ageing process. Oxidative damage and mitochondrial dysfunction do not represent the cause of ageing per se but they have to be analyzed within the complexity of those series of processes occurring during lifespan. The establishment of a crosstalk among them is a shared common feature of many chronic age-related diseases, including neurodegenerative disorders, for which ageing is a major risk factor. The challenge is to understand when and how the interplay between these two systems move towards from normal ageing process to a pathological phenotype. Here in this review, we discuss the crosstalk between mitochondria and cytosolic-ROS. Furthermore, through a visual data mining approach, we attempt to describe the dynamic interplay between mitochondria and cellular redox state on the route from ageing to an AD phenotype.

Partially saturated canthaxanthin alleviates aging-associated oxidative stress in D-galactose administered male wistar rats

It has been earlier reported that partially saturated canthaxanthin (PSC) from Aspergillus carbonarius mutant is non-toxic, has anti-lipid peroxidation activity and can induce apoptosis in prostate cancer cell lines. In the present study, the antiaging effect of PSC was explored in D-galactose administered male wistar rats. 8-10 weeks old, male wistar rats were randomly divided into (i) Vehicle Control Group (VCG), (ii) Aged Control Group (ACG), (iii) Aged + α Lipoic Acid Group (ALG) and (iv) Aged + Partially saturated canthaxanthin Group (APG). Rats received D-galactose (300 mg /kg bwt/day; i.p.) alone (ACG) or together with PSC (APG) (20 mg/kg bwt/day; oral) and α Lipoic Acid (ALG) (80 mg/kg bwt/day; oral) for 10 weeks. Rats in VCG were injected with the same volume of physiological saline (i.p.) and fed with olive oil (vehicle). In vitro protein oxidation and DNA oxidation inhibition, in vivo malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), acetylcholinesterase (AChE) and monoamine oxidase (MAO) activities were determined. In addition, brain neurotransmitters, dopamine and serotonin were estimated by NMR. PSC treatment showed inhibition against protein and DNA oxidation. PSC effectively improved D-galactose induced aging rats by inducing a protective effect through up-regulation of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT) and brain neurotransmitters and downregulated malondialdehyde (MDA) and monoamineoxidase (MAO) levels. Thus, PSC appears to be a functional compound having antioxidant and antiaging properties.

The ratio of prematurely aging to non-prematurely aging mice cohabiting, conditions their behavior, immunity and lifespan

Adult prematurely aging mice (PAM) show behavioral deterioration, premature immunosenescence and increased oxidative stress, impairments that are associated with their shorter lifespan, compared to the corresponding exceptional non-prematurely aging mice (ENPAM). When PAM live in a predominantly ENPAM environment (2/5, respectively) they exhibit an improvement of immunity and redox state in their spleen and thymus leukocytes, and an increased lifespan. Nevertheless, it is unknown if other PAM/ENPAM ratios could affect behavioral and peritoneal leukocyte functions of PAM and change their lifespan. ENPAM and PAM were divided into the following groups: C-ENPAM (8 ENPAM in the cage); C-PAM (8 PAM in the cage); ENPAM>50% and PAM<50% (5 ENPAM/2 PAM in each cage); ENPAM = 50% and PAM = 50% (4 ENPAM/4 PAM in each cage), and PAM>50% and ENPAM<50% (5 PAM/2 ENPAM in each cage). After two months, mice were submitted to a battery of behavioral tests. Several functions and oxidative stress parameters were then assessed in their peritoneal leukocytes. Animals were maintained in these conditions to analyze their lifespan. The results showed that PAM>50%, PAM = 50% and PAM<50% exhibited better behavioral responses, immunity and redox states in their peritoneal leukocytes than C-PAM. This improvement was higher when the number of ENPAM in the cage was increased, with most of the parameters in PAM<50% reaching similar values to those in C-ENPAM, and an increased lifespan. However, ENPAM that cohabited with PAM showed, in general, an impairment of parameters studied. In conclusion, the PAM/ENPAM cohabitation ratio is relevant to behavior and immunity.

The Role of BDNF on Aging-Modulation Markers

An important link between brain aging and a class of growth/survival factors called neurotrophins has recently been demonstrated. In particular, brain-derived neurotrophic factor (BDNF) plays a fundamental role during age-related synaptic loss, preventing cerebral atrophy and cognitive decline. The aim of the present study was to investigate whether the use of low dose BDNF sequentially kinetic activated (SKA) was able to counteract some mechanisms underlying the degeneration and aging of nervous tissue by increasing endogenous protection mechanisms. Both in vitro and in vivo experiments were performed to assess the ability of BDNF SKA to protect and regenerate survival-related molecular pathways, studying intestinal absorption in vitro and brain function in vivo. Our pioneering results show that BDNF SKA is able to induce the endogenous production of BDNF, using its receptor TrkB and influencing the apolipoprotein E expression. Moreover, BDNF SKA exerted effects on β-Amyloid and Sirtuin 1 proteins, confirming the hypothesis of a fine endogenous regulatory effect exerted by BDNF SKA in maintaining the health of both neurons and astrocytes. For this reason, a change in BDNF turnover is considered as a positive factor against brain aging.

Stress-mediated generation of deleterious ROS in healthy individuals - role of cytochrome c oxidase

Psychosocial stress is known to cause an increased incidence of coronary heart disease. In addition, multiple other diseases like cancer and diabetes mellitus have been related to stress and are mainly based on excessive formation of reactive oxygen species (ROS) in mitochondria. The molecular interactions between stress and ROS, however, are still unknown. Here we describe the missing molecular link between stress and an increased cellular ROS, based on the regulation of cytochrome c oxidase (COX). In normal healthy cells, the "allosteric ATP inhibition of COX" decreases the oxygen uptake of mitochondria at high ATP/ADP ratios and keeps the mitochondrial membrane potential (ΔΨm) low. Above ΔΨm values of 140 mV, the production of ROS in mitochondria increases exponentially. Stress signals like hypoxia, stress hormones, and high glutamate or glucose in neurons increase the cytosolic Ca2+ concentration which activates a mitochondrial phosphatase that dephosphorylates COX. This dephosphorylated COX exhibits no allosteric ATP inhibition; consequently, an increase of ΔΨm and ROS formation takes place. The excess production of mitochondrial ROS causes apoptosis or multiple diseases.

Hypoxia attenuate ionic transport in the isolated gill epithelium of Carcinus maenas

The gills are osmorespiratory organs of aquatic organisms and the prime target of environmentally induced hypoxia. We have studied the impact of severe hypoxia (0.5 mg O₂/L) on the ionic transport across posterior gills of Carcinus maenas acclimated to 12 ppt seawater (DSW). The short-circuit current (Isc) across hemilamellae from gills i.e. active ion transport was studied in micro Ussing chambers. Hypoxia induced by deoxygenation of the basolateral side, and not the apical side, resulted in time-dependent inhibition of Isc and full recovery of Isc after reoxygenation. Exposure of the crabs to severe 7 h hypoxia decreased the specific activity of Na⁺,K⁺-ATPase in the gills by 36%. Full recovery of enzyme activity occurred in fasted crabs after 3 days of reoxygenation. The intensity of Western blotting bands was not different in the gills of oxygenated, hypoxic and reoxygenated crabs. The reversible, nonspecific blocker of K⁺ channels Cs and hypoxia inhibited over 90% of Isc which is after reoxygenation fully recovered. The specific blocker of Cl^- channels NPPB [5-nitro-2-(3-phenylpropylamino)benzoic acid] blocked Isc by 68.5%. Only the rest of not inhibited Isc in aerated saline was blocked by hypoxia and recovered after reoxygenation. The activity of the antioxidant enzyme catalase was not changed during hypoxia and reoxygenation kept the high enzyme activity in the gills at the level of crabs acclimated to DSW. As a response to hypoxia the presence of 2 mM H₂O₂ induce an initial slight transient decrease of Isc followed by a rise and after reoxygenation fully recovered Isc. Incubation of hemilamellae with the antioxidant derivative Trolox did not affect the inhibition of Isc by hypoxia.

Free radicals, antioxidants, nuclear factor-E2-related factor-2 and liver damage

Oxidative/nitrosative stress is proposed to be a critical factor in various diseases, including liver pathologies. Antioxidants derived from medicinal plants have been studied extensively and are relevant to many illnesses, including liver diseases. Several hepatic disorders, such as viral hepatitis and alcoholic or nonalcoholic steatohepatitis, involve free radicals/oxidative stress as agents that cause or at least exacerbate liver injury, which can result in chronic liver diseases, such as liver fibrosis, cirrhosis and end-stage hepatocellular carcinoma. In this scenario, nuclear factor-E2-related factor-2 (Nrf2) appears to be an essential factor to counteract or attenuate oxidative or nitrosative stress in hepatic cells. In fact, a growing body of evidence indicates that Nrf2 plays complex and multicellular roles in hepatic inflammation, fibrosis, hepatocarcinogenesis and regeneration via the induction of its target genes. Inflammation is the most common feature of chronic liver diseases, triggering fibrosis, cirrhosis and hepatocellular carcinoma. Increasing evidence indicates that Nrf2 counteracts the proinflammatory process by modulating the recruitment of inflammatory cells and inducing the endogenous antioxidant response of the cell. In this review, the interactions between antioxidant and inflammatory molecular pathways are analyzed.

Role of Combined Lipoic Acid and Vitamin D3 on Astrocytes as a Way to Prevent Brain Ageing by Induced Oxidative Stress and Iron Accumulation

Brain ageing is a complex multifactorial process characterized by gradual and continuous loss of neuronal functions. It is hypothesized that at the basis of brain ageing as well as age-related diseases, there is an impairment of the antioxidant defense system leading to an increase of oxidative stress. In this study, two different biological aspects involved in brain ageing and neurodegeneration have been investigated: oxidative stress and iron accumulation damage. In primary mouse astrocytes, the stimulation with 50 μM lipoic acid (LA) and 100 nM vitamin D (vitD) was first investigated in a time-course study to determine the dosages to be used in combination and then in a permeability test using an in vitro blood-brain barrier. In a second set of experiments, the role of oxidative stress was investigated pretreating astrocytes with 200 μM H₂O₂ for 30 min. The ability of vitD and LA alone and combined together to prevent or repair the damage caused by oxidative stress was investigated after 24 h of stimulation by the MTT test, mitochondrial membrane potential measurement, and Western blot analysis. To induce neurodegeneration, cells were pretreated with 300 μM catalytic iron for 6 days and then treated with vitD and LA alone and combined for additional 6 days to investigate the protection exerted by combination, analyzing viability, ROS production, iron concentration, and activation of intracellular pathways. In our study, the combination of LA and vitD showed beneficial effects on viability of astrocytes, since the substances are able to cross the brain barrier. In addition, combined LA and vitD attenuated the H₂O₂-induced apoptosis through the mitochondrial-mediated pathway. The combination was also able to counteract the adverse conditions caused by iron, preventing its accumulation. All these data support the hypothesis of the synergistic and cooperative activity exerted by LA and vitD in astrocytes indicating a possible new strategy to slow down ageing.

Resistance of Listeria monocytogenes to Stress Conditions Encountered in Food and Food Processing Environments

Listeria monocytogenes is a human food-borne facultative intracellular pathogen that is resistant to a wide range of stress conditions. As a consequence, L. monocytogenes is extremely difficult to control along the entire food chain from production to storage and consumption. Frequent and recent outbreaks of L. monocytogenes infections illustrate that current measures of decontamination and preservation are suboptimal to control L. monocytogenes in food. In order to develop efficient measures to prevent contamination during processing and control growth during storage of food it is crucial to understand the mechanisms utilized by L. monocytogenes to tolerate the stress conditions in food matrices and food processing environments. Food-related stress conditions encountered by L. monocytogenes along the food chain are acidity, oxidative and osmotic stress, low or high temperatures, presence of bacteriocins and other preserving additives, and stresses as a consequence of applying alternative decontamination and preservation technologies such high hydrostatic pressure, pulsed and continuous UV light, pulsed electric fields (PEF). This review is aimed at providing a summary of the current knowledge on the response of L. monocytogenes toward these stresses and the mechanisms of stress resistance employed by this important food-borne bacterium. Circumstances when L. monocytogenes cells become more sensitive or more resistant are mentioned and existence of a cross-resistance when multiple stresses are present is pointed out.

A Tale of Two Concepts: Harmonizing the Free Radical and Antagonistic Pleiotropy Theories of Aging

SIGNIFICANCE

The two foremost concepts of aging are the mechanistic free radical theory (FRT) of how we age and the evolutionary antagonistic pleiotropy theory (APT) of why we age. Both date from the late 1950s. The FRT holds that reactive oxygen species (ROS) are the principal contributors to the lifelong cumulative damage suffered by cells, whereas the APT is generally understood as positing that genes that are good for young organisms can take over a population even if they are bad for the old organisms. Recent Advances: Here, we provide a common ground for the two theories by showing how aging can result from the inherent chemical reactivity of many biomolecules, not just ROS, which imposes a fundamental constraint on biological evolution. Chemically reactive metabolites spontaneously modify slowly renewable macromolecules in a continuous way over time; the resulting buildup of damage wrought by the genes coding for enzymes that generate such small molecules eventually masquerades as late-acting pleiotropic effects. In aerobic organisms, ROS are major agents of this damage but they are far from alone.

CRITICAL ISSUES

Being related to two sides of the same phenomenon, these theories should be compatible. However, the interface between them is obscured by the FRT mistaking a subset of damaging processes for the whole, and the APT mistaking a cumulative quantitative process for a qualitative switch.

FUTURE DIRECTIONS

The manifestations of ROS-mediated cumulative chemical damage at the population level may include the often-observed negative correlation between fitness and the rate of its decline with increasing age, further linking FRT and APT. Antioxid. Redox Signal. 29, 1003-1017.

Effects of vitamin C and E on toxic action of alcohol on partial hepatectomy-induced liver regeneration in rats

The purpose of this study was to investigate the influence of vitamins C and E on the toxic action of alcohol in rat liver regeneration. Male Sprague-Dawley rats subjected to 70% partial hepatectomy were divided into five groups (Groups 1 to 5). Rats in Groups 2 to 5 were only provided alcohol for drinking. Additionally, vitamin C, vitamin E, and vitamin C in combination with vitamin E were administered to Groups 3, 4, and 5, respectively. Alcohol inhibits liver regeneration, resulting in an increase in free radicals produced by alcohol metabolism and thus causing cellular damage and altering liver function. During liver regeneration, vitamins C and E significantly ameliorated liver injury from alcohol administration by reducing hepatic lipid peroxidation. Vitamins C and E protect against liver injury and dysfunction, attenuate lipid peroxidation, and thus may be more effective in combination than either vitamin alone against alcohol-mediated toxic effects during liver regeneration.

Role of recombination and faithfulness to partner in sex chromosome degeneration

Sex determination in mammals is strongly linked to sex chromosomes. In most cases, females possess two copies of X chromosome while males have one X and one Y chromosome. It is assumed that these chromosomes originated from a pair of homologous autosomes, which diverged when recombination between them was suppressed. However, it is still debated why the sex chromosomes stopped recombining and how this process spread out over most part of the chromosomes. To study this problem, we developed a simulation model, in which the recombination rate between the sex chromosomes can freely evolve. We found that the suppression of recombination between the X and Y is spontaneous and proceeds very quickly during the evolution of population, which leads to the degeneration of the Y in males. Interestingly, the degeneration happens only when mating pairs are unfaithful. This evolutionary strategy purifies the X chromosome from defective alleles and leads to the larger number of females than males in the population. In consequence, the reproductive potential of the whole population increases. Our results imply that both the suppression of recombination and the degeneration of Y chromosome may be associated with reproductive strategy and favoured in polygamous populations with faithless mating partners.

PQQ ameliorates D-galactose induced cognitive impairments by reducing glutamate neurotoxicity via the GSK-3β/Akt signaling pathway in mouse

Oxidative stress is known to be associated with various age-related diseases. D-galactose (D-gal) has been considered a senescent model which induces oxidative stress response resulting in memory dysfunction. Pyrroloquinoline quinone (PQQ) is a redox cofactor which is found in various foods. In our previous study, we found that PQQ may be converted into a derivative by binding with amino acid, which is beneficial to several pathological processes. In this study, we found a beneficial glutamate mixture which may diminish neurotoxicity by oxidative stress in D-gal induced mouse. Our results showed that PQQ may influence the generation of proinflammatory mediators, including cytokines and prostaglandins during aging process. D-gal-induced mouse showed increased MDA and ROS levels, and decreased T-AOC activities in the hippocampus, these changes were reversed by PQQ supplementation. Furthermore, PQQ statistically enhanced Superoxide Dismutase SOD2 mRNA expression. PQQ could ameliorate the memory deficits and neurotoxicity induced by D-gal via binding with excess glutamate, which provide a link between glutamate-mediated neurotoxicity, inflammation and oxidative stress. In addition, PQQ reduced the up-regulated expression of p-Akt by D-gal and maintained the activity of GSK-3β, resulting in a down-regulation of p-Tau level in hippocampus. PQQ modulated memory ability partly via Akt/GSK-3β pathway.

Premature aging in behavior and immune functions in tyrosine hydroxylase haploinsufficient female mice. A longitudinal study

Aging is accompanied by impairment in the nervous, immune, and endocrine systems as well as in neuroimmunoendocrine communication. In this context, there is an age-related alteration of the physiological response to acute stress, which is modulated by catecholamine (CA), final products of the sympathetic-adreno-medullary axis. The involvement of CA in essential functions of the nervous system is consistent with the neuropsychological deficits found in mice with haploinsufficiency (hemizygous; HZ) of tyrosine hydroxylase (TH) enzyme (TH-HZ). However, other possible alterations in regulatory systems have not been studied in these animals. The aim of the present work was to analyze whether adult TH-HZ female mice presented the impairment of behavioral traits and immunological responses that occurs with aging and whether they had affected their mean lifespan. ICR-CD1 female TH-HZ and wild type (WT) mice were used in a longitudinal study. Behavioral tests were performed on adult and old mice in order to evaluate their sensorimotor abilities and exploratory capacity, as well as anxiety-like behaviors. At the ages of 2 ± 1, 4 ± 1, 9 ± 1, 13 ± 1 and 20 ± 1 months, peritoneal leukocytes were extracted and several immune functions were assessed (phagocytic capacity, Natural Killer (NK) cytotoxicity, and lymphoproliferative response to lipopolysaccharide (LPS) and concanavalin A (ConA)). In addition, several oxidative stress parameters (catalase, glutathione reductase and glutathione peroxidase activities, and reduced glutathione (GSH) concentrations as antioxidant compounds as well as xanthine oxidase activity, oxidized glutathione (GSSG) concentrations, and GSSG/GSH ratio as oxidants) were analyzed. As inflammatory stress parameters TNF-alpha and IL-10 concentrations, and TNF-alpha/IL-10 ratios as inflammatory/anti-inflammatory markers, were measured. Animals were maintained in standard conditions until their natural death. The results indicate that adult TH-HZ mice presented worse sensorimotor abilities and exploratory capacity than their WT littermates as well as greater anxiety-like behaviors. With regards to the immune system, adult TH-HZ animals exhibited lower values of phagocytic capacity, NK cytotoxicity, and lymphoproliferative response to LPS and ConA than WT mice. Moreover, immune cells of TH-HZ mice showed higher oxidative and inflammatory stress than those of WT animals. Although these differences between TH-HZ and WT, in general, decreased with aging, this premature immunosenescence and impairment of behavior of TH-HZ mice was accompanied by a shorter mean lifespan in comparison to WT counterparts. In conclusion, haploinsufficiency of th gene in female mice appears to provoke premature aging of the regulatory systems affecting mean lifespan.

Effects of parsley supplementation on the seminal quality, blood lipid profile and oxidant status of young and old male rabbits

<p>The high unsaturation levels of spermatozoal membrane make it very susceptible to oxidative damage and this problem increases with advancing age. In this study, the aim is to investigate whether parsley seed (PS) has a protective effect on semen quality, serum lipid profile and antioxidative status of old and young bucks. Male rabbits (n= 36) (18 young 9-12 mo old and 18 old 36-42 mo old) were each assigned to 3 dietary treatments (a control and 2 levels of PS: 0.3 and 0.6 kg/100 kg diet) to evaluate the ability of parsley to enhance bucks’ reproductive status. Most of the studied traits were adversely affected by age of rabbit bucks. On the other hand, the inclusion of PS significantly boosted ejaculate volume and improved mass motility concentration and total sperm output. Seminal plasma and blood serum total antioxidant capacity increased, while serum lipid peroxidase decreased with parsley treatments. In conclusion, dietary supplementation of parsley seed alleviates most semen quality parameters and counteracts oxidative stress, especially with the advance of age (seminal plasma and blood serum of total antioxidant capacity and malondialdehyde.</p>

Association between dietary patterns and cognitive function among 70-year-old Japanese elderly: a cross-sectional analysis of the SONIC study

BACKGROUND

An increasing number of studies in Western countries have shown that healthy dietary patterns may have a protective effect against cognitive decline and dementia. However, information on this relationship among non-Western populations with different cultural settings is extremely limited. We aim to examine the relationship between dietary patterns and cognitive function among older Japanese people.

METHODS

This cross-sectional study included 635 community-dwelling people aged 69-71 years who participated in the prospective cohort study titled Septuagenarians, Octogenarians, Nonagenarians Investigation with Centenarians (SONIC). Diet was assessed over a one-month period with a validated, brief-type, self-administered diet history questionnaire. Dietary patterns from thirty-three predefined food groups [energy-adjusted food (g/d)] were extracted by factor analysis. Cognitive function was assessed using the Japanese version of the Montreal Cognitive Assessment (MoCA-J). Multivariate regression analysis was performed to examine the relationship between dietary patterns and cognitive function.

RESULTS

Three dietary patterns were identified: the 'Plant foods and fish', 'Rice and miso soup', and 'Animal food' patterns. The 'Plant foods and fish' pattern, characterized by high intakes of green and other vegetables, soy products, seaweeds, mushrooms, potatoes, fruit, fish, and green tea, was significantly associated with a higher MoCA-J score [MoCA-J score per one-quartile increase in dietary pattern: β = 0.56 (95% CI: 0.33, 0.79), P for trend <0.001]. This association was still evident after adjustment for potential confounding factors [β = 0.41 (95% CI: 0.17, 0.65), P for trend <0.001]. In contrast, neither the 'Rice and miso soup' nor the 'Animal food' pattern was related to cognitive function. To confirm the possibility of reverse causation we also conducted a sensitivity analysis excluding 186 subjects who reported substantial changes in their diet for any reason, but the results did not change materially.

CONCLUSION

This preliminary cross-sectional study suggests that a diet with high intakes of vegetables, soy products, fruit, and fish may have a beneficial effect on cognitive function in older Japanese people. Further prospective studies are needed to confirm this finding.

Relationship between hyposalivation and oxidative stress in aging mice

The increase in oxidative stress that accompanies aging has been implicated in the abnormal advance of aging and in the onset of various systemic diseases. However, the details of what effects the increase in oxidative stress that accompanies aging has on saliva secretion are not known. In this study, naturally aging mice were used to examine the stimulated whole saliva flow rate, saliva and serum oxidative stress, antioxidant level, submandibular gland H-E staining, and immunofluorescence staining to investigate the effect of aging on the volume of saliva secretion and the relationship with oxidative stress, as well as the effect of aging on the structure of salivary gland tissue. The stimulated whole saliva flow rate decreased significantly with age. Also, oxidative stress increased significantly with age. Antioxidant levels, however, decreased significantly with age. Structural changes of the submandibular gland accompanying aging included atrophy of parenchyma cells and fatty degeneration and fibrosis of stroma, and the submandibular gland weight ratio decreased. These results suggest that oxidative stress increases with age, not just systemically but also locally in the submandibular gland, and that oxidative stress causes changes in the structure of the salivary gland and is involved in hyposalivation.

Evidence that a mitochondrial death spiral underlies antagonistic pleiotropy

The antagonistic pleiotropy (AP) theory posits that aging occurs because alleles that are detrimental in older organisms are beneficial to growth early in life and thus are maintained in populations. Although genes of the insulin signaling pathway likely participate in AP, the insulin‐regulated cellular correlates of AP have not been identified. The mitochondrial quality control process called mitochondrial autophagy (mitophagy), which is inhibited by insulin signaling, might represent a cellular correlate of AP. In this view, rapidly growing cells are limited by ATP production; these cells thus actively inhibit mitophagy to maximize mitochondrial ATP production and compete successfully for scarce nutrients. This process maximizes early growth and reproduction, but by permitting the persistence of damaged mitochondria with mitochondrial DNA mutations, becomes detrimental in the longer term. I suggest that as mitochondrial ATP output drops, cells respond by further inhibiting mitophagy, leading to a further decrease in ATP output in a classic death spiral. I suggest that this increasing ATP deficit is communicated by progressive increases in mitochondrial ROS generation, which signals inhibition of mitophagy via ROS‐dependent activation of insulin signaling. This hypothesis clarifies a role for ROS in aging, explains why insulin signaling inhibits autophagy, and why cells become progressively more oxidized during aging with increased levels of insulin signaling and decreased levels of autophagy. I suggest that the mitochondrial death spiral is not an error in cell physiology but rather a rational approach to the problem of enabling successful growth and reproduction in a competitive world of scarce nutrients.

Nampt Expression Decreases Age-Related Senescence in Rat Bone Marrow Mesenchymal Stem Cells by Targeting Sirt1

Senescence restricts the development of applications involving mesenchymal stem cells (MSCs) in research fields, such as tissue engineering, and stem cell therapeutic strategies. Understanding the mechanisms underlying natural aging processes may contribute to the development of novel approaches to preventing age-related diseases or slowing individual aging processes. Nampt is a rate-limiting NAD biosynthetic enzyme that plays critical roles in energy metabolism, cell senescence and maintaining life spans. However, it remains unknown whether Nampt influences stem cell senescence. In this study, the function of Nampt was investigated using a rat model of natural aging. Our data show that Nampt expression was significantly lower in MSCs obtained from aged rats than in those obtained from young rats during physiological aging. Reducing the level of Nampt in aged MSCs resulted in lower intracellular concentrations of NAD+ and downregulated Sirt1 expression and activity. After the Nampt inhibitor FK866 was added, young MSCs were induced to become aged cells. The enhanced senescence was correlated with NAD+ depletion and Sirt1 activity attenuation. In addition, Nampt overexpression attenuated cell senescence in aged MSCs. Our findings provide a new explanation for the mechanisms underlying stem cell senescence and a novel target for delaying stem cell senescence and preventing and treating age-related diseases.

Chironomus riparius exposure to fullerene-contaminated sediment results in oxidative stress and may impact life cycle parameters

A key component of understanding the potential environmental risks of fullerenes (C60) is their potential effects on benthic invertebrates. Using the sediment dwelling invertebrate Chironomus riparius we explored the effects of acute (12h and 24h) and chronic (10d, 15d, and 28d) exposures of sediment associated fullerenes. The aims of this study were to assess the impact of exposure to C60 in the sediment top layer ((0.025, 0.18 and 0.48) C60 mg/cm2) on larval growth, oxidative stress and emergence rates and to quantify larval body burdens in similarly exposed organisms. Oxidative stress localization was observed in the tissues next to the microvilli and exoskeleton through a method for identifying oxidative stress reactions generated by reactive oxygen species. Rapid intake of fullerenes was shown in acute experiments, whereas body residues decreased after chronic exposure. Transmission electron microscopy analysis revealed oxidative damage and structural changes in cells located between the lipid droplets and next to the microvilli layer in fullerene exposed samples. Fullerene associated sediments also caused changes in the emergence rate of males and females, suggesting that the cellular interactions described above or other effects from the fullerenes may influence reproduction rates.

TRAIL facilitates cytokine expression and macrophage migration during hypoxia/reoxygenation via ER stress-dependent NF-κB pathway

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), which is known as a key molecule to induce cancer cell apoptosis, has also been found to participate in the process of ischemia/reperfusion (I/R) injury. Infiltrated macrophages play dual roles in inflammatory injury and healing following I/R. Whether TRAIL has any effect on macrophages during this process remains elusive. Here we showed that I/R triggered the expressions of TRAIL, DR5 and cytokines (IL-1β, TNFα, CCL-2 and ICAM-1), in addition to macrophage infiltration, which could be abolished by TRAIL neutralizing antibody. In vitro, TRAIL enhanced DR5 expression and facilitated the macrophages migration following hypoxia/reoxygenation (H/R) treatment in a dose-dependent manner via ER stress and NF-κB signaling pathways, which is accompanied by inflammatory factors expression. The increased cytokines production (such as TNFα and IL-1β) stimulated by TRAIL can be blocked by the NF-κB and ER stress inhibitor. The results also suggested that NF-κB activation of macrophages during H/R was regulated by ER stress. Thus, our research present that TRAIL affects functional activities of macrophages during I/R injury, which may be a potential therapeutic target for ischemic heart disease.

Implications of oxidative stress on viral pathogenesis

Reactive species are frequently formed after viral infections. Antioxidant defences, including enzymatic and non-enzymatic components, protect against reactive species, but sometimes these defences are not completely adequate. An imbalance in the production of reactive species and the body's inability to detoxify these reactive species is referred to as oxidative stress. The aim of this review is to analyse the role of oxidative stress in the pathogenesis of viral infections and highlight some major therapeutic approaches that have gained importance, with regards to controlling virus-induced oxidative injury. Attention will be focused on DNA viruses (papillomaviruses, hepadnaviruses), RNA viruses (flaviviruses, orthomyxoviruses, paramyxoviruses, togaviruses) and retroviruses (human immunodeficiency virus). In general, viruses cause an imbalance in the cellular redox environment, which depending on the virus and the cell can result in different responses, e.g. cell signaling, antioxidant defences, reactive species, and other processes. Therefore, the modulation of reactive species production and oxidative stress potentially represents a novel pharmacological approach for reducing the consequences of viral pathogenesis.

Dysregulation of Intracellular Ca2+ in Dystrophic Cortical and Hippocampal Neurons

Duchenne muscular dystrophy (DMD) is an inherited X-linked disorder characterized by skeletal muscle wasting, cardiomyopathy, as well as cognitive impairment. Lack of dystrophin in striated muscle produces dyshomeostasis of resting intracellular Ca²⁺ ([Ca²⁺]_i), Na⁺ ([Na⁺]_i), and oxidative stress. Here, we test the hypothesis that similar to striated muscle cells, an absence of dystrophin in neurons from mdx mice (a mouse model for DMD) is also associated with dysfunction of [Ca²⁺]_i homeostasis and oxidative stress. [Ca²⁺]_i and [Na⁺]_i in pyramidal cortical and hippocampal neurons from 3 and 6 months mdx mice were elevated compared to WT in an age-dependent manner. Removal of extracellular Ca²⁺ reduced [Ca²⁺]_i in both WT and mdx neurons, but the decrease was greater and age-dependent in the latter. GsMTx-4 (a blocker of stretch-activated cation channels) significantly decreased [Ca²⁺]_i and [Na⁺]_i in an age-dependent manner in all mdx neurons. Blockade of ryanodine receptors (RyR) or inositol triphosphate receptors (IP3R) reduced [Ca²⁺]_i in mdx. Mdx neurons showed elevated and age-dependent reactive oxygen species (ROS) production and an increase in neuronal damage. In addition, mdx mice showed a spatial learning deficit compared to WT. GsMTx-4 intraperitoneal injection reduced neural [Ca²⁺]_i and improved learning deficit in mdx mice. In summary, mdx neurons show an age-dependent dysregulation in [Ca²⁺]_i and [Na⁺]_i which is mediated by plasmalemmal cation influx and by intracellular Ca²⁺ release through the RyR and IP3R. Also, mdx neurons have elevated ROS production and more extensive cell damage. Finally, a reduction of [Ca²⁺]_i improved cognitive function in mdx mice.

Environmental preconditioning rejuvenates adult stem cells' proliferation and chondrogenic potential

Adult stem cells are a promising cell source for cartilage regeneration. Unfortunately, due to donor age and ex vivo expansion, stem cell senescence becomes a huge hurdle for these cells to be used clinically. Increasing evidence indicates that environmental preconditioning is a powerful approach in promoting stem cells' ability to resist a harsh environment post-engraftment, such as hypoxia and inflammation. However, few reports organize and evaluate the literature regarding the rejuvenation effect of environmental preconditioning on stem cell proliferation and chondrogenic differentiation capacity, which are important variables for stem cell based tissue regeneration. This report aims to identify several critical environmental factors such as oxygen concentration, growth factors, and extracellular matrix and to discuss their preconditioning influence on stem cells' rejuvenation including proliferation and chondrogenic potential as well as underlying molecular mechanisms. We believe that environmental preconditioning based rejuvenation is a simpler and safer strategy to program pre-engraftment stem cells for better survival and enhanced proliferation and differentiation capacity without the undesired effects of some treatments, such as genetic manipulation.

Mitochondrial peroxiredoxins are essential in regulating the relationship between Drosophila immunity and aging

Previously, we have shown that flies under-expressing the two mitochondrial peroxiredoxins (Prxs), dPrx3 and dPrx5, display increases in tissue-specific apoptosis and dramatically shortened life span, associated with a redox crisis, manifested as changes in GSH:GSSG and accumulation of protein mixed disulfides. To identify specific pathways responsible for the observed biological effects, we performed a transcriptome analysis. Functional clustering revealed a prominent group enriched for immunity-related genes, including a considerable number of NF-kB-dependent antimicrobial peptides (AMP) that are up-regulated in the Prx double mutant. Using qRT-PCR analysis we determined that the age-dependent changes in AMP levels in mutant flies were similar to those observed in controls when scaled to percentage of life span. To further clarify the role of Prx-dependent mitochondrial signaling, we expressed different forms of dPrx5, which unlike the uniquely mitochondrial dPrx3 is found in multiple subcellular compartments, including mitochondrion, nucleus and cytosol. Ectopic expression of dPrx5 in mitochondria but not nucleus or cytosol partially extended longevity under normal or oxidative stress conditions while complete restoration of life span occurred when all three forms of dPrx5 were expressed from the wild type dPrx5 transgene. When dPrx5 was expressed in mitochondria or in all three compartments, it substantially delayed the development of hyperactive immunity while expression of cytosolic or nuclear forms had no effect on the immune phenotype. The data suggest a critical role of mitochondria in development of chronic activation of the immune response triggered by impaired redox control.

Hearing impairment, cochlear morphology, and peroxynitrite (ONOO(-)) formation in adult and aging NOS II knockout mice

CONCLUSION

Nitric oxide synthase (NOS) II induction is a protective mechanism against age-related degeneration of the cochlea.

OBJECTIVES

An induction of NOS II has been described in different inner ear pathologies. The objective was to examine the role of NOS II in age-related degeneration of the cochlea.

METHODS

The hearing ability in adult and aging NOS II knockout mice (KO) and their wildtype (WT) littermates was explored via auditory brainstem response (ABR) measurements. Inner ear morphological differences were studied with scanning electron microscopy (SEM). Immunohistochemistry was used to examine the induction of NOS II in the inner ear of aging WT mice. Expression of nitrotyrosin, a marker protein for the reactive oxygen species peroxynitrite, was compared between KO and WT mice using immunohistochemistry.

RESULTS

Adult KO mice exhibited a mild hearing impairment. WT mice showed an induction of NOS II after 6 months of age. Age-related hearing deterioration was accelerated in KO mice, which was accompanied by increased nitrotyrosin formation and outer hair cell loss.

In Vivo Detection of Reactive Oxygen Species and Redox Status in Caenorhabditis elegans

SIGNIFICANCE

Due to its large families of redox-active enzymes, genetic amenability, and complete transparency, the nematode Caenorhabditis elegans has the potential to become an important model for the in vivo study of redox biology.

RECENT ADVANCES

The recent development of several genetically encoded ratiometric reactive oxygen species (ROS) and redox sensors has revolutionized the quantification and precise localization of ROS and redox signals in living organisms. Only few exploratory studies have applied these sensors in C. elegans and undoubtedly much remains to be discovered in this model. As a follow-up to our recent findings that the C. elegans somatic gonad uses superoxide and hydrogen peroxide (H2O2) signals to communicate with the germline, we here analyze the patterns of H2O2 inside the C. elegans germline.

CRITICAL ISSUES

Despite the advantages of genetically encoded ROS and redox sensors over classic chemical sensors, still several general as well as C. elegans-specific issues need to be addressed. The major concerns for the application of these sensors in C. elegans are (i) decreased vitality of some reporter strains, (ii) interference of autofluorescent compartments with the sensor signal, and (iii) the use of immobilization methods that do not influence the worm's redox physiology.

FUTURE DIRECTIONS

We propose that several of the current issues may be solved by designing reporter strains carrying single copies of codon-optimized sensors. Preferably, these sensors should have their emission wavelengths in the red region, where autofluorescence is absent. Worm analysis could be optimized using four-dimensional ratiometric fluorescence microscopy of worms immobilized in microfluidic chips. Antioxid. Redox Signal. 25, 577-592.

Protective Effects of Selenium, Vitamin E, and Purple Carrot Anthocyanins on D-Galactose-Induced Oxidative Damage in Blood, Liver, Heart and Kidney Rats

The present study was performed to investigate the protective effects of selenium (Se), vitamin E (Vit E) and anthocyanins from purple carrots and their combination against the oxidative stress induced by D-galactose in rats. A total of 80 male rats were equally divided into 11 groups, one of which acted as control (I) just receiving intraperitoneal injections of physiological saline. The remaining ten groups (II-XI) were intraperitoneally injected with D-galactose at a dose of 400 mg kg(-1) body weight (BW) per day for 42 consecutive days. Rats in groups III-XI were treated with antioxidants via gavage per day as follows: group III: Se-methylselenocysteine (SeMSC), IV: Se as sodium selenite (Na2SeO3), V: Se-enriched yeast (SeY), VI: Vit E as α-tocopherol acetate, VII: anthocyanin from purple carrots (APC), VIII: APC + Vit E, IX: SeMSC + APC+ Vit E, X: Na2SeO3 + APC + Vit E, XI: SeY + Ant + Vit E. The results showed that the rats treated with antioxidants (III-XI) showed significant decreases in the levels of malondialdehyde (MDA) and carbonyl protein (PCO) compared with the D-galactose-treated group (II) in the heart, liver, kidneys, and blood. Moreover, there were significant increases in the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), glutathione (GSH) concentration, and total antioxidant capacity (T-AOC) in the heart, liver, kidneys, and blood of antioxidant-treated animals (III-XI) than those in control group (I). In addition, the combined treatments of two or three antioxidants showed greater antioxidant activities than those of individual treatments, suggesting the synergistic antioxidant effects of Se, Vit E, and APC. In conclusion, all the antioxidants exhibited protective effects against D-galactose-induced oxidative damage in rats, and these antioxidants showed a synergistic effect.

The critical shoulder angle is associated with rotator cuff tears and shoulder osteoarthritis and is better assessed with radiographs over MRI

PURPOSE

The purpose of this study was to determine whether there is an association between the critical shoulder angle (CSA) and rotator cuff tears (RCT) as well as osteoarthritis (OA), and to compare the reproducibility and accuracy of CSA values as measured with radiograph and MRI.

METHODS

Based on a pre hoc power analysis, three independent reviewers measured CSAs for three groups of 10 age-matched patients each (RCT group, OA group, and non-RCT/non-OA group) using radiographs and MRIs. Inter- and intra-observer agreements of CSAs were determined with intraclass correlation coefficients. ANOVA analysis was performed.

RESULTS

Interobserver and intra-observer agreements on radiographs were 0.87 (95 % CI 0.78-0.93) and 0.91 (95 % CI 0.82-0.96), respectively. Significant differences in mean CSAs by radiographs were found between the groups (RCT 37.3° ± 2.6°; OA 28.7° ± 2.2°; non-RCT/non-OA 32.7° ± 2.5°; p < 0.001). CSAs obtained from MRI scans had interobserver agreement of 0.62 (95 % CI 0.43-0.78) and intra-observer agreement of 0.68 (95 % CI 0.50-0.80). There was a significant correlation between the patients' pathologies and CSAs measured by radiographs (r = 0.44; p = 0.02) and MRI (r = 0.50; p = 0.01). A significant difference in mean CSAs measured on radiograph versus MRI was seen in the OA group (28.7° ± 2.2° vs. 31.3° ± 4.4°; p = 0.01).

CONCLUSION

CSA measurements obtained from radiographs demonstrated excellent interobserver agreement with less variability than CSAs from MRI, especially in OA patients. This study confirms an association between the CSA and RCTs as well as OA pathology. Assessing the CSA may be helpful during diagnostic evaluation of patients with shoulder pain and can help predict pathology.

LEVEL OF EVIDENCE

Retrospective cohort study, Level IV.