Molecular mechanisms of life- and health-span extension: role of calorie restriction and exercise intervention

Body composition measures as a determinant of Alpelisib related toxicity

BACKGROUND

Body composition has emerged as an important prognostic factor in patients treated with cancer. Severe depletion of skeletal muscle, sarcopenia, has been associated with poor performance status and worse oncological outcomes. We studied patients with metastatic breast cancer receiving alpelisib, to determine if sarcopenia and additional body composition measures accounting for muscle and adiposity are associated with toxicity.

METHODS

A retrospective observational analysis was conducted, including 38 women with metastatic breast cancer and a PIK3CA mutation, treated with alpelisib as advanced line of therapy. Sarcopenia was determined by measuring skeletal muscle cross-sectional area at the third lumbar vertebra using computerized tomography. Various body composition metrics were assessed along with drug toxicity, dose reductions, treatment discontinuation, hospitalizations, time to treatment failure and overall survival.

RESULTS

Sarcopenia was observed in half of the patients (n = 19, 50%), spanning normal weight, overweight, and obese individuals. Among the body composition measures, lower skeletal muscle density (SMD) was associated with an increased risk of treatment-related hyperglycaemia (P = 0.03). Additionally, lower visceral adipose tissue (VAT) was associated with alpelisib-induced rash (P = 0.04) and hospitalizations (P = 0.04). Notably, alpelisib treatment discontinuation was not impacted by alpelisib toxicity.

CONCLUSION

Body composition measures, specifically SMD and VAT may provide an opportunity to identify patients at higher risk for severe alpelisib related hyperglycemia, and cutaneous toxicity. These findings suggest the potential use of body composition assessment to caution toxicity risk, allowing for personalized therapeutic observation and intervention.

Association between plant protein intake and grip strength in Koreans aged 50 years or older: Korea National Health and Nutrition Examination Survey 2016-2018

BACKGROUND/OBJECTIVES

We investigated the association of plant and animal protein intake with grip strength in Koreans aged ≥ 50 yrs.

SUBJECTS/METHODS

The data was collected from 3,610 men and 4,691 women (≥ 50 yrs) from the 2016-2018 Korea National Health and Nutrition Examination Survey. We calculated the total energy intake, and the intake of animal and plant protein and collected dietary data using 1-day 24-h dietary recalls. Low grip strength (LGS) was defined as the lowest quintile (men: up to 26.8 kg, women: up to 15.7 kg). The association of protein intake with grip strength was examined using Pearson's correlation and multiple linear regression analysis.

RESULTS

The results proved that participants with LGS had lower daily energy, protein and fat intake, and percent energy from protein than those with normal or high grip strength (P < 0.0001). Total energy intake, animal protein, and plant protein were positively associated with grip strength. A higher intake of total plant protein (P for trend = 0.004 for men, 0.05 for women) and legumes, nuts, and seeds (LNS) protein (P for trend = 0.01 for men, 0.02 for women) was significantly associated with a lower prevalence of LGS. However, non-LNS plant protein intake was not associated with LGS (P for trend = 0.10 for men, 0.15 for women). In women, a higher total animal protein intake was significantly associated with decreased LGS (P for trend = 0.03).

CONCLUSIONS

Higher total plant protein and LNS protein intake are negatively associated with LGS.

Oxidative stress, inflammation and hormesis: The role of dietary and lifestyle modifications on aging

Oxidative stress (OS) is primarily caused by the formation of free radicals and reactive oxygen species; it is considered as one of the prominent factors in slowing down and degrading cellular machinery of an individual, and it eventually leads to aging and age-related diseases by its continuous higher state. The relation between molecular damage and OS should be particularized to understand the beginning of destruction at the cellular levels, extending outwards to affect tissues, organs, and ultimately to the organism. Several OS biomarkers, which are established at the biomolecular level, are useful in investigating the disease susceptibility during aging. Slowing down the aging process is a matter of reducing the rate of oxidative damage to the cellular machinery over time. The breakdown of homeostasis, the mild overcompensation, the reestablishment of homeostasis, and the adaptive nature of the process are the essential features of hormesis, which incorporates several factors, including calorie restriction, nutrition and lifestyle modifications that play an important role in reducing the OS. In the current review, along with the concept and theories of aging (with emphasis on free radical theory), various manifestations of OS with special attention on mitochondrial dysfunction and age-related diseases have been discussed. To alleviate the OS, hormetic approaches including caloric restriction, exercise, and nutrition have also been discussed.

Bidirectional association between visual impairment and frailty among community-dwelling older adults: a longitudinal study

Background

Vision impairment is common among older adults, and it may be related to frailty. However, the longitudinal relationship between visual impairment and frailty is still unclear.

Methods

We used data from Round 1 to Round 5 from the National Health and Aging Trend Study. Two samples were community-dwelling older adults, sample 1 (without visual impairment) was classified according to whether they have pre-frailty/frailty at R1 (N = 3013) and sample 2 (without pre-frailty/frailty) was classified according to whether they have visual impairment at R1 (N = 1422), respectively. Frailty was measured using five criteria: experiencing exhaustion, unintentional weight loss, low physical activity, slow gait, and weak grip strength. Visual impairment was assessed by asking participants if they had any visual impairment. Generalized estimating equation models were used to examine the concurrent and lagged association between visual impairment and frailty.

Results

The participants were on average 76 ± 7 years old, female (59%), non-Hispanic white (74%) with less than bachelor educated (73%), and 44% were pre-frail/frail in the older adults without visual impairment. Approximately 5% of participants had visual impairment at R1, and they tended to be female and non-Hispanic White in the older adults without frailty. The concurrent (OR, 95% CI = 1.55, 1.17-2.02) and lagged (OR, 95% CI = 1.79, 1.25-2.59) associations between frailty and visual impairment were significantly after controlling the covariates. Similarly, the concurrent (OR, 95% CI = 1.63, 1.32-2.04) and lagged (OR, 95% CI = 1.49, 1.20-1.87) associations between visual impairment and frailty were also significant.

Conclusions

Overall, this study provides evidence for a longitudinal, bidirectional association between self-reported visual impairment and frailty. Future intervention programs to delay frailty progression should include strategies that may reduce the incidence of visual impairment.

Objectively measured far vision impairment and sarcopenia among adults aged ≥ 65 years from six low- and middle-income countries

BACKGROUND

There are currently no studies on visual impairment and sarcopenia. We investigated the cross-sectional association between objectively measured far vision impairment and sarcopenia in a nationally representative sample of older adults aged 65 years and over from six low- and middle-income countries (LMICs).

METHODS

Cross-sectional, community-based data from the study on global ageing and adult health (SAGE) were analyzed. Far vision acuity was measured using the tumbling E LogMAR chart and classified as: no vision impairment (6/12 or better); mild vision impairment (6/18 or better but worse than 6/12); moderate vision impairment (6/60 or better but worse than 6/18); severe vision impairment (worse than 6/60). Sarcopenia was defined as having low skeletal muscle mass and either a slow gait speed or a weak handgrip strength. Associations were assessed with multivariable logistic regression.

RESULTS

Fourteen thousand five hundred and eighty five individuals aged ≥ 65 years were included in the analysis [mean (SD) age 72.6 (11.5) years; 54.1% females]. After adjustment for multiple potential confounders, compared to those with no vision impairment, the OR (95% CI) for sarcopenia in those with mild, moderate, and severe vision impairment were 1.10 (0.87-1.40), 1.69 (1.25-2.27), and 3.38 (1.69-6.77), respectively. The estimates for females and males were similar.

CONCLUSIONS

The odds for sarcopenia increased with increasing severity of far vision impairment among older people in LMICs. The mere co-occurrence of these conditions is concerning, and it may be prudent to implement interventions to address/prevent sarcopenia in those with far vision impairment through the promotion of physical activity and appropriate nutrition.

Thiol-disulfide homeostasis and ischemia-modified albumin as a marker of oxidative stress in patients with sarcopenia

AIM

Sarcopenia is characterized by progressive and generalized loss of skeletal muscle mass and strength. Chronic inflammatory conditions and increased oxidative stress are in the pathogenesis of sarcopenia. Our aim was to evaluate the relationship between sarcopenia and thiol-disulfide homeostasis and ischemia-modified albumin levels as an oxidative stress marker.

METHODS

Patients aged ≥65 years were recruited in this study. Sarcopenia was diagnosed according to the European Working Group on Sarcopenia in Older People criterion. Total thiol, native thiol, disulfide and ischemia-modified albumin levels were measures according to clinical and laboratory features. Patients were divided into two groups according to their sarcopenia presence; thiol-disulfide homeostasis and ischemia-modified albumin levels were evaluated between these groups.

RESULTS

Overall, 94 patients were analyzed. The mean age was 75.0 ± 6.71 years. A total of 39% of the patients were diagnosed as probable sarcopenia, 3.2% had sarcopenia, 6.4% had severe sarcopenia and 51.1% were diagnosed as normal. The levels of native thiol, total thiol, disulfide level and disulfide-native thiol, native thiol-total thiol and disulfide-total thiol ratios were similar in patients with sarcopenia when compared with the control group. In addition, there were no differences between albumin and ischemia-modified albumin levels. In univariate regression analysis, handgrip strength was found to be an independent predictor of native thiol and total thiol, and disulfide levels.

CONCLUSION

This is the first study in the literature that evaluates the thiol-disulfide homeostasis and ischemia-modified albumin levels in sarcopenic older patients. Long-term studies are warranted to confirm the relationship between oxidative stress markers and sarcopenia. Geriatr Gerontol Int 2021; 21: 584-589.

Comorbid Depressive Symptoms, Visual Impairment, and Sarcopenia among Middle-Aged and Older Women: Findings from the West China Health and Aging Trend study

Previous reports have described close relationships between sarcopenia and either visual impairment or depression, but there have been few analyses investigating the association between sarcopenia and the coexistence of both visual impairment and depression. Herein, we sought to explore the associations between sarcopenia and comorbid depressive symptoms and visual impairment among older females. A cross-sectional analysis of females between the ages of 50 and 95 (n = 2454) from the West China Health and Aging Trend (WCHAT) study was conducted. Patient muscle mass was assessed via a bioimpedance-based approach using an InBody 770 device, while muscle strength was estimated based on handgrip strength as quantified with a digital grip strength dynamometer. Depressive systems were evaluated with the 15-item Geriatric Depression Scale (GDS-15), and a questionnaire was employed to evaluate patient visual functionality. Associations between sarcopenia and comorbid depressive status and visual impairment were explored through logistic regression analyses. Comorbid depressive symptoms and visual impairment were observed in 6.2% of the women included in this study, while 18.9% suffered from sarcopenia. Following adjustment for covariates, relative to normal controls, study subjects with only depression (OR=1.45, 95%CI=1.04-2.02), only visual impairment (OR=1.69, 95%CI=1.27-2.26), or comorbid depression and visual impairment (OR=1.76, 95% CI=1.16-2.67) exhibited a higher risk of sarcopenia. These results suggest that comorbid depression and visual impairment are linked to the prevalence of sarcopenia in older Chinese women. As such, further efforts to screen older women for these two comorbid conditions may thus be necessary.

Dietary restriction and/or exercise training impairs spermatogenesis in normal rats

Dietary restriction and/or exercise has been shown to have multiple benefits for health. However, its effects on reproductive health and the mechanisms by which it regulates reproductive function remain unclear. Here, to evaluate its effects on spermatogenesis and sperm function, rats were divided into 4 groups: ad libitum-fed sedentary control, dietary restriction (DR), exercise training (ET), and dietary restriction plus exercise training (DR+ET) groups. Results indicated that body weight, epididymal fat pad weight, and sperm counts were significantly reduced in the DR, ET, and DR+ET groups. Moreover, sperm motility and capacitation-associated protein tyrosine phosphorylation were suppressed in the DR and DR+ET groups, but not the ET group. Microarray analysis revealed that the number of downregulated genes was higher than that of upregulated genes in the DR and/or ET groups. About half of the downregulated genes are common after exercise training and/or diet restriction. Gene ontology analysis showed that downregulated genes in the DR, ET, and DR+ET groups affected spermatogenesis through overlapping pathways, including glucocorticoid, corticosteroid, extracellular structure organization, and estradiol responses. Our findings suggest that diet restriction and/or exercise training may present potential risks to male reproductive dysfunction by disrupting normal gene expression patterns in the testis. Novelty: Dietary restriction and/or exercise can lead to the damage of spermatogenesis as well as sperm maturation. Sperm functional changes are more sensitive to dietary restriction than exercise training. Dietary restriction and exercise impair spermatogenesis through overlapping biological pathways in the testis.

Understanding the Physiological Links Between Physical Frailty and Cognitive Decline

Declines in both physical and cognitive function are associated with increasing age. Understanding the physiological link between physical frailty and cognitive decline may allow us to develop interventions that prevent and treat both conditions. Although there is significant epidemiological evidence linking physical frailty to cognitive decline, a complete understanding of the underpinning biological basis of the two disorders remains fragmented. This narrative review discusses insights into the potential roles of chronic inflammation, impaired hypothalamic-pituitary axis stress response, imbalanced energy metabolism, mitochondrial dysfunction, oxidative stress, and neuroendocrine dysfunction linking physical frailty with cognitive decline. We highlight the importance of easier identification of strategic approaches delaying the progression and onset of physical frailty and cognitive decline as well as preventing disability in the older population.

Corticosterone-Mediated Body Weight Loss Is an Important Catabolic Process for Poststroke Immunity and Survival

Background and Purpose- Stroke-induced acute severe body weight (BW) loss is associated with a high rate of mortality during a critical poststroke period. Several interventions to reduce weight loss, however, have not been successful. Currently, the biological significance of this extraordinary catabolic process is not well understood. Spleen-derived monocytes/macrophages (MMs) are the major immune cells recruited to the injured brain. The trafficking of MMs has been shown to be important for tissue repair and recovery. The purpose of the study is to investigate whether the BW reduction is essential for MM-mediated immune response for mice to survive and whether a corticosterone-mediated catabolic event underlies the processes. Methods- C57BL/6 male mice (12-week-old) were subjected to transient middle cerebral artery occlusion. BW, total MMs, and their Ly-6Chigh and Ly-6Clow subsets were determined in the spleen, blood, and the brain in poststroke mice. Poststroke survival rate and MM subsets were determined in mice with adrenalectomy, sham-adrenalectomy, and adrenalectomy mice supplemented with corticosterone. Results- Stroke reduced BW with a maximum reduction at day 3 poststroke (17.2±5.2%). The reduction at day 3 was positively linked to injury severity and selective depletion of MMs, but no other types of immune cells, in the spleen. Notably, the splenic MM depletion was significantly greater in mice with severe BW reduction (≥18% at day 3). In the blood, stroke depleted circulating MMs to a similar degree in animals with moderate and severe BW loss. Ly-6C+ monocyte infiltration in the poststroke brain was greater in mice with severe BW loss. Blocking the catabolic process by adrenalectomy significantly increased poststroke mortality, but the mortality was partially rescued by corticosterone supplement in adrenalectomy mice. Conclusions- Stroke-induced BW loss facilitates MM-mediated immune response, and the adrenal corticosterone-mediated catabolic process is necessary for poststroke survival. Visual Overview- An online visual overview is available for this article.

Oxidative stress and anti-oxidant responses to regular resistance training in young and older adult women

AIM

The aging process is associated with increased production of free radicals, but regular exercise training might create a balance between oxidative stress and the anti-oxidant system. The aim of the present study was to investigate the effect of resistance training (RT) on the serum levels of tumor necrosis factor-α, malondialdehyde, total anti-oxidant capacity and nuclear factor-κB in young and older adult women.

METHODS

A total of 44 women were divided into four groups: older-training, older-control, young-training and young-control. The experimental groups carried out 12 weeks of RT with an intensity of 75% one repetition maximum.

RESULTS

After finishing the RT program, total anti-oxidant capacity and nuclear factor-κB in both the young and older adult training groups were significantly increased, whereas malondialdehyde in the young and the older exercising groups decreased. In addition, malondialdehyde in both the older and young groups, and total anti-oxidant capacity in only the young group, were respectively lower and higher compared with their inactive counterparts. No significant changes in tumor necrosis factor-α occurred in training groups after the 12-week intervention, but the older and younger training groups had a significant difference with the young control group in the post-test.

CONCLUSIONS

It seems that the strengthening of the anti-oxidant system resulting from regular RT in older adults is similar to those of young people. Geriatr Gerontol Int 2019; 19: 419-422.

Nuclear Accumulation of HSP70 in Mouse Skeletal Muscles in Response to Heat Stress, Aging, and Unloading With or Without Reloading

The purpose of this study was to investigate the nuclear accumulation of heat shock protein 70 (HSP70), a molecular chaperonin in mouse skeletal muscle in response to aging, heat stress, and hindlimb unloading with or without reloading. Profiles of HSP70-specific nuclear transporter Hikeshi in skeletal muscles were also evaluated. Heat stress-associated nuclear accumulation of HSP70 was observed in slow soleus (SOL) and fast plantaris (PLA) muscles of young (10-week-old) mice. Mean nuclear expression level of HSP70 in slow medial gastrocnemius (MGAS) and PLA muscles of aged (100-week-old) mice increased ~4.8 and ~1.7 times, compared to that of young (10-week-old) mice. Reloading following 2-week hindlimb unloading caused accumulation of HSP70 in myonuclei in MGAS and PLA of young mice ( p < 0.05). However, reloading-associated nuclear accumulation of HSP70 was not observed in both types of muscles of aged mice. On the other hand, 2-week hindlimb unloading had no impact on the nuclear accumulation of HSP70 in both muscles of young and aged mice. Nuclear expression level of Hikeshi in both MGAS and PLA in mice was suppressed by aging. No significant changes in the nuclear Hikeshi in both muscles were induced by unloading with or without reloading. Results of this study indicate that the nuclear accumulation of HSP70 might show a protective response against cellular stresses in skeletal muscle and that the protective response may be suppressed by aging. Protective response to aging might depend on muscle fiber types.

Aerobic and strength training induce changes in oxidative stress parameters and elicit modifications of various cellular components in skeletal muscle of aged rats

Skeletal muscle aging is associated with loss of mass, function, and strength-a condition known as sarcopenia. It has been reported that sarcopenia can be attenuated by physical exercise. Therefore, we investigated whether 2 different physical exercise protocols could modulate and induce changes in oxidative and inflammatory parameters, as well as in BDNF and DNA repair enzyme levels in skeletal muscle tissue of aged rats. Aging Wistar rats performed treadmill or strength training for 50 min 3 to 4 times a week for 8 weeks. Strength training decreased 2',7'-dichlorofluorescein (DCFH) oxidation (P = 0.0062); however, nitric oxide, protein deglycase DJ-1, and tumor necrosis factor alpha (TNF-α) levels increased after aerobic training (P = 0.04, P = 0.027 and P = 0.009, respectively). Both exercise protocols increased superoxide dismutase (SOD) and catalase (CAT) activity (P = 0.0017 and P = 0.0326) whereas the activity of glutathione (GSH) (P = 0.0001) was decreased. Brain-derived neurotropic factor (BDNF) levels were not affected by exercise, but 8-oxoguanine glycosylase (OGG1) decreased after strength training (P = 0.0007). In conclusion, oxidative parameters showed that skeletal muscle adapt to increased ROS levels, reducing the risk of free radical damage to the tissue after both exercise protocols. These results show that the effects of physical exercise on skeletal muscle are mediated in an exercise type-dependent manner.

Role of metabolic stress for enhancing muscle adaptations: Practical applications

Metabolic stress is a physiological process that occurs during exercise in response to low energy that leads to metabolite accumulation [lactate, phosphate inorganic (Pi) and ions of hydrogen (H⁺)] in muscle cells. Traditional exercise protocol (i.e., Resistance training) has an important impact on the increase of metabolite accumulation, which influences hormonal release, hypoxia, reactive oxygen species (ROS) production and cell swelling. Changes in acute exercise routines, such as intensity, volume and rest between sets, are determinants for the magnitude of metabolic stress, furthermore, different types of training, such as low-intensity resistance training plus blood flow restriction and high intensity interval training, could be used to maximize metabolic stress during exercise. Thus, the objective of this review is to describe practical applications that induce metabolic stress and the potential effects of metabolic stress to increase systemic hormonal release, hypoxia, ROS production, cell swelling and muscle adaptations.

Exercise, oxidants, and antioxidants change the shape of the bell-shaped hormesis curve

It is debated whether exercise-induced ROS production is obligatory to cause adaptive response. It is also claimed that antioxidant treatment could eliminate the adaptive response, which appears to be systemic and reportedly reduces the incidence of a wide range of diseases. Here we suggest that if the antioxidant treatment occurs before the physiological function-ROS dose-response curve reaches peak level, the antioxidants can attenuate function. On the other hand, if the antioxidant treatment takes place after the summit of the bell-shaped dose response curve, antioxidant treatment would have beneficial effects on function. We suggest that the effects of antioxidant treatment are dependent on the intensity of exercise, since the adaptive response, which is multi pathway dependent, is strongly influenced by exercise intensity. It is further suggested that levels of ROS concentration are associated with peak physiological function and can be extended by physical fitness level and this could be the basis for exercise pre-conditioning. Physical inactivity, aging or pathological disorders increase the sensitivity to oxidative stress by altering the bell-shaped dose response curve.

Adherence to a Mediterranean-Style Diet and Effects on Cognition in Adults: A Qualitative Evaluation and Systematic Review of Longitudinal and Prospective Trials

The Mediterranean-style diet (MedDiet) involves substantial intake of fruits, vegetables, and fish, and a lower consumption of dairy, red meat, and sugars. Over the past 15 years, much empirical evidence supports the suggestion that a MedDiet may be beneficial with respect to reducing the incidence of cardiovascular disease, cancer, metabolic syndrome, and dementia. A number of cross-sectional studies that have examined the impact of MedDiet on cognition have yielded largely positive results. The objective of this review is to evaluate longitudinal and prospective trials to gain an understanding of how a MedDiet may impact cognitive processes over time. The included studies were aimed at improving cognition or minimizing of cognitive decline. Studies reviewed included assessments of dietary status using either a food frequency questionnaire or a food diary assessment. Eighteen articles meeting our inclusion criteria were subjected to systematic review. These revealed that higher adherence to a MedDiet is associated with slower rates of cognitive decline, reduced conversion to Alzheimer's disease, and improvements in cognitive function. The specific cognitive domains that were found to benefit with improved Mediterranean Diet Score were memory (delayed recognition, long-term, and working memory), executive function, and visual constructs. The current review has also considered a number of methodological issues in making recommendations for future research. The utilization of a dietary pattern, such as the MedDiet, will be essential as part of the armamentarium to maintain quality of life and reduce the potential social and economic burden of dementia.

Radical Oxygen Species, Exercise and Aging: An Update

It is now well established that reactive oxygen species (ROS) play a dual role as both deleterious and beneficial species. In fact, ROS act as secondary messengers in intracellular signalling cascades; however, they can also induce cellular senescence and apoptosis. Aging is an intricate phenomenon characterized by a progressive decline in physiological functions and an increase in mortality, which is often accompanied by many pathological diseases. ROS are involved in age-associated damage to macromolecules, and this may cause derangement in ROS-mediated cell signalling, resulting in stress and diseases. Moreover, the role of oxidative stress in age-related sarcopenia provides strong evidence for the important contribution of physical activity to limit this process. Regular physical activity is considered a preventive measure against oxidative stress-related diseases. The aim of this review is to summarize the currently available studies investigating the effects of chronic and/or acute physical exercise on the oxidative stress process in healthy elderly subjects. Although studies on oxidative stress and physical activity are limited, the available information shows that acute exercise increases ROS production and oxidative stress damage in older adults, whereas chronic exercise could protect elderly subjects from oxidative stress damage and reinforce their antioxidant defences. The available studies reveal that to promote beneficial effects of physical activity on oxidative stress, elderly subjects require moderate-intensity training rather than high-intensity exercise.

Redox Characterization of Functioning Skeletal Muscle

Skeletal muscle physiology is influenced by the presence of chemically reactive molecules such as reactive oxygen species (ROS). These molecules regulate multiple redox-sensitive signaling pathways that play a critical role in cellular processes including gene expression and protein modification. While ROS have gained much attention for their harmful effects in muscle fatigue and dysfunction, research has also shown ROS to facilitate muscle adaptation after stressors such as physical exercise. This manuscript aims to provide a comprehensive review of the current understanding of redox signaling in skeletal muscle. ROS-induced oxidative stress and its role in the aging process are discussed. Mitochondria have been shown to generate large amounts of ROS during muscular contractions, and thus are susceptible to oxidative stress. ROS can modify proteins located in the mitochondrial membrane leading to cell death and osmotic swelling. ROS also contribute to the necrosis and inflammation of muscle fibers that is associated with muscular diseases including Duchenne muscular dystrophy. It is imperative that future research continues to investigate the exact role of ROS in normal skeletal muscle function as well as muscular dysfunction and disease.

Rapamycin Versus Intermittent Feeding: Dissociable Effects on Physiological and Behavioral Outcomes When Initiated Early and Late in Life

Rapamycin, an inhibitor of the mammalian target of rapamycin pathway, has been shown to increase mammalian life span; less is known concerning its effect on healthspan. The primary aim of this study was to examine rapamycin's role in the alteration of several physiological and behavioral outcomes compared with the healthspan-inducing effects of intermittent feeding (IF), another life-span-enhancing intervention. Male Fisher 344 × Brown Norway rats (6 and 25 months of age) were treated with rapamycin or IF for 5 weeks. IF and rapamycin reduced food consumption and body weight. Rapamycin increased relative lean mass and decreased fat mass. IF failed to alter fat mass but lowered relative lean mass. Behaviorally, rapamycin resulted in high activity levels in old animals, IF increased levels of "anxiety" for both ages, and grip strength was not significantly altered by either treatment. Rapamycin, not IF, decreased circulating leptin in older animals to the level of young animals. Glucose levels were unchanged with age or treatment. Hypothalamic AMPK and pAMPK levels decreased in both older treated groups. This pattern of results suggests that rapamycin has more selective and healthspan-inducing effects when initiated late in life.

The Effects of Calorie Restriction in Depression and Potential Mechanisms

Depression, also called major depressive disorder, is a neuropsychiatric disorder jeopardizing an increasing number of the population worldwide. To date, a large number of studies have devoted great attention to this problematic condition and raised several hypotheses of depression. Based on these theories, many antidepressant drugs were developed for the treatment of depression. Yet, the depressed patients are often refractory to the antidepressant therapies. Recently, increasing experimental evidences demonstrated the effects of calorie restriction in neuroendocrine system and in depression. Both basic and clinical investigations indicated that short-term calorie restriction might induce an antidepressant efficacy in depression, providing a novel avenue for treatment. Molecular basis underlying the antidepressant actions of calorie restriction might involve multiple physiological processes, primarily including orexin signaling activation, increased CREB phosphorylation and neurotrophic effects, release of endorphin and ketone production. However, the effects of chronic calorie restriction were quite controversial, in the cases that it often resulted in the long-term detrimental effects via inhibiting the function of 5-HT system and decreasing leptin levels. Here we review such dual effects of calorie restriction in depression and potential molecular basis behind these effects, especially focusing on antidepressant effects.

Age-dependent effect of every-other-day feeding and aerobic exercise in ubiquinone levels and related antioxidant activities in mice muscle

Aging affects many biochemical, cellular, and physiological processes in the organisms. Accumulation of damage based on oxidized macromolecules is found in many age-associated diseases. Coenzyme Q (Q) is one of the main molecules involved in metabolic and antioxidant activities in cells. Q-dependent antioxidant activities are importantly involved on the protection of cell membranes against oxidation. Many studies indicate that Q decay in most of the organs during aging. In our study, no changes in Q levels were found in old animals in comparison with young animals. On the other hand, the interventions, caloric restriction based on every-other-day feeding procedure, and physical exercise were able to increase Q levels in muscle, but only in old and not in young animals. Probably, this effect prevented the increase in lipid peroxidation found in aged animals and also protein carbonylation. Further, Q-dependent antioxidant activities such as NADH-cytochrome b5 reductase and NAD(P)H-quinone oxidoreductase 1 are also modulated by both exercise and every other day feeding. Taken together, we demonstrate that exercise and dietary restriction as every-other-day procedure can regulate endogenous synthesized Q levels and Q-dependent antioxidant activities in muscle, preventing oxidative damage in aged muscle.

Age- and calorie restriction-related changes in rat brain mitochondrial DNA and TFAM binding

Aging markedly affects mitochondrial biogenesis and functions particularly in tissues highly dependent on the organelle's bioenergetics capability such as the brain's frontal cortex. Calorie restriction (CR) diet is, so far, the only intervention able to delay or prevent the onset of several age-related alterations in different organisms. We determined the contents of mitochondrial transcription factor A (TFAM), mitochondrial DNA (mtDNA), and the 4.8-kb mtDNA deletion in the frontal cortex from young (6-month-old) and aged (26-month-old), ad libitum-fed (AL) and calorie-restricted (CR), rats. We found a 70 % increase in TFAM amount, a 25 % loss in mtDNA content, and a 35 % increase in the 4.8-kb deletion content in the aged AL animals with respect to the young rats. TFAM-specific binding to six mtDNA regions was analyzed by mtDNA immunoprecipitation and semiquantitative polymerase chain reaction (PCR), showing a marked age-related decrease. Quantitative real-time PCR at two subregions involved in mtDNA replication demonstrated, in aged AL rats, a remarkable decrease (60-70 %) of TFAM-bound mtDNA. The decreased TFAM binding is a novel finding that may explain the mtDNA loss in spite of the compensatory TFAM increased amount. In aged CR rats, TFAM amount increased and mtDNA content decreased with respect to young rats' values, but the extent of the changes was smaller than in aged AL rats. Attenuation of the age-related effects due to the diet in the CR animals was further evidenced by the unchanged content of the 4.8-kb deletion with respect to that of young animals and by the partial prevention of the age-related decrease in TFAM binding to mtDNA.

PGC-1α transcriptional response and mitochondrial adaptation to acute exercise is maintained in skeletal muscle of sedentary elderly males

The aim of the present study was to examine the effects of ageing and training status on (1) markers of skeletal muscle mitochondrial content and (2) the ability to activate the acute signalling pathways associated with regulating exercise-induced mitochondrial biogenesis. Muscle biopsies were obtained from the vastus lateralis muscle of young untrained (24 ± 4 years, n = 6; YU), young trained (22 ± 3 years, n = 6; YT), old untrained (65 ± 6 years, n = 6; OU) and old trained (64 ± 3 years, n = 6; OT) healthy males before and after (3 h and 3 days post-exercise) completion of high-intensity interval cycling exercise. In resting muscle, lifelong training preserved mtDNA, PGC-1α and COXIV protein content such that muscles from OT individuals were comparable to muscles from both YU and YT individuals, whereas lifelong sedentary behaviour reduced such markers of mitochondrial content. Regardless of age or training status, acute exercise induced comparable increases in p38MAPK phosphorylation immediately post-exercise, PGC-1α and COXIV mRNA expression at 3 h post-exercise and COXIV protein at 3 days post-exercise. Data demonstrate that lifelong endurance training preserves skeletal muscle PGC-1α content and that despite the mitochondrial dysfunction typically observed with sedentary ageing, muscles from sedentary elderly individuals retain the capacity to activate the acute signalling pathways associated with regulating the early processes of mitochondrial biogenesis. We consider our data to have immediate translational potential as they highlight the potential therapeutic effects of exercise to induce skeletal muscle mitochondrial biogenesis persist late in adulthood, even after a lifetime of physical inactivity.

Of mice and men: the benefits of caloric restriction, exercise, and mimetics

During aging there is an increasing imbalance of energy intake and expenditure resulting in obesity, frailty, and metabolic disorders. For decades, research has shown that caloric restriction (CR) and exercise can postpone detrimental aspects of aging. These two interventions invoke a similar physiological signature involving pathways associated with stress responses and mitochondrial homeostasis. Nonetheless, CR is able to delay aging processes that result in an increase of both mean and maximum lifespan, whereas exercise primarily increases healthspan. Due to the strict dietary regime necessary to achieve the beneficial effects of CR, most studies to date have focused on rodents and non-human primates. As a consequence, there is vast interest in the development of compounds such as resveratrol, metformin and rapamycin that would activate the same metabolic- and stress-response pathways induced by these interventions without actually restricting caloric intake. Therefore the scope of this review is to (i) describe the benefits of CR and exercise in healthy individuals, (ii) discuss the role of these interventions in the diseased state, and (iii) examine some of the promising pharmacological alternatives such as CR- and exercise-mimetics.

Envelhecimento, estresse oxidativo e sarcopenia: uma abordagem sistêmica

INTRODUÇÃO: a sarcopenia é caracterizada pela perda de massa e funcionalidade muscular e está associada a uma série de disfunções e doenças sistêmicas que acometem os idosos. Também é um dos parâmetros utilizados para definição da síndrome de fragilidade, que é altamente prevalente em idosos, conferindo maior risco para quedas, fraturas, incapacidade, dependência, hospitalização recorrente e mortalidade. Recentemente, a literatura tem reportado que a etiopatogenia da sarcopenia está intimamente relacionada com um aumento na taxa de produção de espécie reativa de oxigênio (ERO), o que pode ocasionar a denervação, perda e atrofia de fibras musculares e consequente perda da força muscular. OBJETIVO: realizar uma revisão narrativa da literatura sobre o papel do estresse oxidativo na gênese da sarcopenia. MÉTODO: revisão narrativa. Foram consultadas as bases de dados MEDLINE, LILACS e SciElo. As buscas foram feitas através das expressões: sarcopenia e envelhecimento, perda de massa muscular em idosos, estresse oxidativo, inflamação e sarcopenia e epidemiologia da sarcopenia. Resultados: a etiologia da sarcopenia é multifatorial e envolve a interação de diversos fatores, incluindo aspectos genéticos, metabólicos, estilo de vida, como os hábitos alimentares (ingestão protéica) e de gasto energético (atividade física), e as EROs desempenham papel-chave na mediação do processo de perda de massa e função muscular associado ao envelhecimento. CONCLUSÃO: ao longo do processo de envelhecimento, o estresse oxidativo torna-se mais perigoso, uma vez que, associado ao declínio dos hormônios sexuais, que exercem efeitos anabólicos sobre o tecido músculo-esquelético, pode acelerar a perda e atrofia desse tecido.

Oxidative stress, frailty and cognitive decline

The causes of frailty are complex and must be accepted as multidimensional based on the interplay of genetic, biological, physical, psychological, social and environmental factors, although inflammation and oxidative stress are two factors that play an important role in the development of symptoms with those fragile states.

OBJECTIVE

to establish the relationship between oxidative stress, frailty and decline cognitive.

METHODS

A review of the literature and data abstraction from papers are showing the relationship between a) oxidative stress and frailty, b) oxidative stress and decline cognitive.

RESULTS

The papers reviewed showed that we can establish a relationship between the progress of neurodegenerative disorders and increased oxidative stress. Also found in frailty, that oxidative stress plays an important role as one of the starting points for the appearance of permanent inflammatory states.

CONCLUSIONS

Although the literature indicates the relationship between oxidative stress, frailty and decline cognitive, more studies are needed in this regard, especially interventions that asses whether increased intake of antioxidants in older frailty may improve the progress of disease and slow cognitive decline.

Neurophysiological and epigenetic effects of physical exercise on the aging process

Aging is a gradual process during which molecular and cellular processes deteriorate progressively, often leading to such pathological conditions as vascular and metabolic disorders and cognitive decline. Although the mechanisms of aging are not yet fully understood, inflammation, oxidative damage, mitochondrial dysfunction, functional alterations in specific neuronal circuits and a restricted degree of apoptosis are involved. Physical exercise improves the efficiency of the capillary system and increases the oxygen supply to the brain, thus enhancing metabolic activity and oxygen intake in neurons, and increases neurotrophin levels and resistance to stress. Regular exercise and an active lifestyle during adulthood have been associated with reduced risk and protective effects for mild cognitive impairment and Alzheimer's disease. Similarly, studies in animal models show that physical activity has positive physiological and cognitive effects that correlate with changes in transcriptional profiles. According to numerous studies, epigenetic events that include changes in DNA methylation patterns, histone modification and alterations in microRNA profiles seem to be a signature of aging. Hence, insight into the epigenetic mechanisms involved in the aging process and their modulation through lifestyle interventions such as physical exercise might open new avenues for the development of preventive and therapeutic strategies to treat aging-related diseases.

Usefulness of preclinical models for assessing the efficacy of late-life interventions for sarcopenia

Caloric restriction and physical exercise have proven beneficial against age-associated changes in body composition and declining physical performance; however, little is known regarding what benefit these interventions might have when initiated late in life. The study of mimetics of diet and exercise and the combination thereof may provide additional treatments for a vulnerable elderly population; however, how and when to initiate such interventions requires consideration in developing the most safe and efficacious treatment strategies. In this review, we focus on preclinical late-life intervention studies, which assess the relationship between physical function, sarcopenia, and body composition. We provide a conceptual framework for the ever-changing definition of sarcopenia and a rationale for the use of an appropriate rodent model of this condition. We finish by providing our perspective regarding the implications of this body of work and future areas of research that may also contribute to the ultimate goal of extending healthspan.

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.

Development of a serum profile for healthy aging

Increasing numbers of Americans are reaching 85 years of age or older, yet there are no reliable biomarkers to predict who will live this long. The goal of this pilot study therefore was: (1) to identify a potential serum pattern that could identify proteins involved in longevity and (2) to determine if this pattern was a marker of longevity in an independent sample of individuals. Serum samples were analyzed in three cohorts of individuals (n = 12 in each) aged 20-34, 60-74, and ≥ 90 years who participated in The Louisiana Healthy Aging Study. The 12 most abundant proteins were removed and the remaining proteins separated by two-dimensional gel electrophoresis. Gels were matched and the intensity of each spot quantified. Multivariate discriminant analysis was used to identify a serum pattern that could separate these three age cohorts. Seven protein spots were found that correctly distinguished the subjects into the three groups. However, these spots were not as successful in discriminating the ages in a second set of 15 individuals as only eight of these subjects were placed into their correct group. These preliminary results show that the proteomics approach can be used to identify potential proteins or markers that may be involved in the aging process and/or be important determinants of longevity.

The role of genetic variants in human longevity

Human longevity is a complex phenotype with a strong genetic predisposition. Increasing evidence has revealed the genetic antecedents of human longevity. This article aims to review the data of various case/control association studies that examine the difference in genetic polymorphisms between long-lived people and younger subjects across different human populations. There are more than 100 candidate genes potentially involved in human longevity; this article particularly focuses on genes of the insulin/IGF-1 pathway, FOXO3A, FOXO1A, lipoprotein metabolism (e.g., APOE and PON1), and cell-cycle regulators (e.g., TP53 and P21). Since the confirmed genetic components for human longevity are few to date, further precise assessment of the genetic contributions is required. Gaining a better understanding of the contribution of genetics to human longevity may assist in the design of improved treatment methods for age-related diseases, delay the aging process, and, ultimately, prolong the human lifespan.

Oxidative stress, molecular inflammation and sarcopenia

Sarcopenia is the decline of muscle mass and strength with age. Evidence suggests that oxidative stress and molecular inflammation play important roles in age-related muscle atrophy. The two factors may interfere with the balance between protein synthesis and breakdown, cause mitochondrial dysfunction, and induce apoptosis. The purpose of this review is to discuss some of the major signaling pathways that are activated or inactivated during the oxidative stress and molecular inflammation seen in aged skeletal muscle. Combined interventions that may be required to reverse sarcopenia, such as exercise, caloric restriction, and nutrition, will also be discussed.

Antiaging, longevity and calorie restriction

PURPOSE OF REVIEW

The role of calorie restriction in humans is controversial. Recently, new data in monkeys and humans have provided new insights into the potential role of calorie restriction in longevity.

RECENT FINDINGS

A study in rhesus monkeys showed a reduction in aging-associated mortality. A number of controlled studies have suggested a variety of beneficial effects during studies of 6-12 months in humans. Major negative effects in humans were loss of muscle mass, muscle strength and loss of bone.

SUMMARY

Dietary restriction in rodents has not been shown to be effective when started in older rodents. Weight loss in humans over 60 years of age is associated with increased mortality, hip fracture and increased institutionalization. Calorie restriction in older persons should be considered experimental and potentially dangerous. Exercise at present appears to be a preferable treatment for older persons.

The IRS2 Gly1057Asp variant is associated with human longevity

BACKGROUND

Reduced insulin and insulin-like growth factor-1 (IGF-1) signaling extends the life span of invertebrate and mammals. Recently, reduced insulin receptor substrate-2 (IRS2) signaling was found associated with increased longevity in mice. The aim of our study was to evaluate whether a common polymorphism (Gly1057Asp) in human IRS2 gene is associated with human longevity.

METHODS

Six hundred seventy-seven participants (289 males and 388 females) between 16 and 104 years of age, categorized as long lived (LL; >85 years old) or controls (C; <85 years old), were genotyped for Gly1057Asp-IRS2 locus variability (rs1805097). All participants, contacted at home or in their institution or selected from Italian geriatric and internal medicine or geriatric rehabilitation structures, underwent to a clinical, biochemical, and functional characterization, with particular attention to the insulin and IGF-1 signaling. Insulin resistance (Homeostasis Model Assessment [HOMA]-IR), insulin sensitivity (HOMA IS), and ss-cell function (HOMA-B cell) were calculated by the HOMA2 calculator v2.2 (www.dtu.ox.ac.uk/homa).

RESULTS

In the whole population, homozygous IRS2(Asp/Asp) participants were more represented among LL versus C participants (16.7% vs 12.0%; p = .04). The association between IRS2 gene polymorphism with longevity (being LL) was independent of anthropometric and metabolic covariates (odds ratio: 2.07, 95% confidence interval [CI] = 1.38-3.12; p = .001). Categorizing participants into percentiles by age, IRS2(Asp/Asp) participants were more likely to reach extreme old age (>or=90 percentile, 96-104 years; odds ratio: 2.03, 95% CI = 1.39-2.99; p = .0003).

CONCLUSIONS

These results support the hypothesis that the IRS2 branch of the insulin and IGF signaling is associated with human longevity. Further studies will be necessary for replicating our finding in an independent larger population group with sufficient power before the association between IRS2 gene polymorphism and longevity can be regarded as proven. Furthermore, studies of genetic and/or environmental background interactions may be useful after basic replication is complete.

Pyrroloquinoline quinone stimulates mitochondrial biogenesis through cAMP response element-binding protein phosphorylation and increased PGC-1alpha expression

Bioactive compounds reported to stimulate mitochondrial biogenesis are linked to many health benefits such increased longevity, improved energy utilization, and protection from reactive oxygen species. Previously studies have shown that mice and rats fed diets lacking in pyrroloquinoline quinone (PQQ) have reduced mitochondrial content. Therefore, we hypothesized that PQQ can induce mitochondrial biogenesis in mouse hepatocytes. Exposure of mouse Hepa1-6 cells to 10-30 microm PQQ for 24-48 h resulted in increased citrate synthase and cytochrome c oxidase activity, Mitotracker staining, mitochondrial DNA content, and cellular oxygen respiration. The induction of this process occurred through the activation of cAMP response element-binding protein (CREB) and peroxisome proliferator-activated receptor-gamma coactivator-1alpha (PGC-1alpha), a pathway known to regulate mitochondrial biogenesis. PQQ exposure stimulated phosphorylation of CREB at serine 133, activated the promoter of PGC-1alpha, and increased PGC-1alpha mRNA and protein expression. PQQ did not stimulate mitochondrial biogenesis after small interfering RNA-mediated reduction in either PGC-1alpha or CREB expression. Consistent with activation of the PGC-1alpha pathway, PQQ increased nuclear respiratory factor activation (NRF-1 and NRF-2) and Tfam, TFB1M, and TFB2M mRNA expression. Moreover, PQQ protected cells from mitochondrial inhibition by rotenone, 3-nitropropionic acid, antimycin A, and sodium azide. The ability of PQQ to stimulate mitochondrial biogenesis accounts in part for action of this compound and suggests that PQQ may be beneficial in diseases associated with mitochondrial dysfunction.

Caloric restriction, SIRT1 and longevity

More than 70 years after its initial report, caloric restriction stands strong as the most consistent non-pharmacological intervention increasing lifespan and protecting against metabolic disease. Among the different mechanisms by which caloric restriction might act, Sir2/SIRT1 (Silent information regulator 2/Silent information regulator T1) has been the focus of much attention because of its ability to integrate sensing of the metabolic status with adaptive transcriptional outputs. This review focuses on gathered evidence suggesting that Sir2/SIRT1 is a key mediator of the beneficial effects of caloric restriction and addresses the main questions that still need to be answered to consolidate this hypothesis.

Exercise-training in young Drosophila melanogaster reduces age-related decline in mobility and cardiac performance

Declining mobility is a major concern, as well as a major source of health care costs, among the elderly population. Lack of mobility is a primary cause of entry into managed care facilities, and a contributing factor to the frequency of damaging falls. Exercise-based therapies have shown great promise in sustaining mobility in elderly patients, as well as in rodent models. However, the genetic basis of the changing physiological responses to exercise during aging is not well understood. Here, we describe the first exercise-training paradigm in an invertebrate genetic model system. Flies are exercised by a mechanized platform, known as the Power Tower, that rapidly, repeatedly, induces their innate instinct for negative geotaxis. When young flies are subjected to a carefully controlled, ramped paradigm of exercise-training, they display significant reduction in age-related decline in mobility and cardiac performance. Fly lines with improved mitochondrial efficiency display some of the phenotypes observed in wild-type exercised flies. The exercise response in flies is influenced by the amount of protein and lipid, but not carbohydrate, in the diet. The development of an exercise-training model in Drosophila melanogaster opens the way to direct testing of single-gene based genetic therapies for improved mobility in aged animals, as well as unbiased genetic screens for loci involved in the changing response to exercise during aging.

Influence of calorie restriction on measures of age-related cognitive decline: role of increased physical activity

Controversy exists as to whether lifelong 40% calorie restriction (CR) enhances, has no effect on, or disrupts cognitive function during aging. Here, we report the effects of CR versus ad-lib feeding on cognitive function in male Brown Norway x Fisher344 rats across a range of ages (8-38 months), using two tasks that are differentially sensitive to age-related cognitive decline: object recognition and Morris water maze (MWM). All ages performed equally in object recognition, whereas, as a group, CR rats were impaired. In contrast, there was an age-related impairment in the MWM that was attenuated by CR as measured by time in proximity with and latency to reach the platform. Distance to the platform, a more sensitive measure, was not affected by CR. Finally, CR resulted in an overall increase in physical activity, one of several behavioral confounders to consider in the interpretation of cognitive outcomes in both tasks.

Dietary patterns associated with Alzheimer's disease: population based study

Recently dietary pattern analysis has emerged as a way for examining diet-disease relations in Alzheimer’s disease. In contrast with the conventional approach, which focuses on a single nutrient or a few nutrients or foods, this method considers overall eating patterns. We examined the dietary patterns defined by factor analysis using data collected with a food-frequency questionnaire in people with Alzheimer’s disease (AD) as compared to healthy controls. The diet data were obtained during population based study of the prevalence of Alzheimer’s disease in a population in Poland. Stratified sampling and random selection strategies were combined to obtain a representative population for screening (age group > 55). From the population screened three times, 71 people were diagnosed with Alzheimer’s according to DSM-IV, and were recruited for further diet risk factors assessment. A group of people with Alzheimer disease (n = 71; F/M 42/29) and the same number of healthy, age and gender matched control were recruited for the study. Patients and their caregivers as well as controls were presented with a food frequency questionnaire based on the 12 food groups. Factor analysis (principal component) was used to derive food patterns. The analysis was conducted using the factor procedure. The factors were rotated by an orthogonal transformation (Varimax rotation) to achieve simpler structure with greater interpretability. Using factor analysis, we identified major eating patterns, one for Alzheimer’s patients and a different one for control group. The AD dietary pattern, FACTOR AD was characterized by a high intake of meat, butter, high-fat dairy products, eggs, and refined sugar, whereas the other pattern, (FACTOR C) was characterized by a high intake of grains and vegetables. These data indicate the existence of dietary patterns defined by factor analysis with data from a food frequency questionnaire, characteristic for Alzheimer’s disease in a Polish population.

Molecular inflammation: underpinnings of aging and age-related diseases

Recent scientific studies have advanced the notion of chronic inflammation as a major risk factor underlying aging and age-related diseases. In this review, low-grade, unresolved, molecular inflammation is described as an underlying mechanism of aging and age-related diseases, which may serve as a bridge between normal aging and age-related pathological processes. Accumulated data strongly suggest that continuous (chronic) upregulation of pro-inflammatory mediators (e.g., TNF-alpha, IL-1beta, IL-6, COX-2, iNOS) are induced during the aging process due to an age-related redox imbalance that activates many pro-inflammatory signaling pathways, including the NF-kappaB signaling pathway. These pro-inflammatory molecular events are discussed in relation to their role as basic mechanisms underlying aging and age-related diseases. Further, the anti-inflammatory actions of aging-retarding caloric restriction and exercise are reviewed. Thus, the purpose of this review is to describe the molecular roles of age-related physiological functional declines and the accompanying chronic diseases associated with aging. This new view on the role of molecular inflammation as a mechanism of aging and age-related pathogenesis can provide insights into potential interventions that may affect the aging process and reduce age-related diseases, thereby promoting healthy longevity.

Relationship between physical activity level, telomere length, and telomerase activity

PURPOSE

The purpose of this study was to examine the relationship of exercise energy expenditure (EEE) with both telomere length and telomerase activity in addition to accounting for hTERT C-1327T promoter genotype.

METHODS

Sixty-nine (n = 34 males; n = 35 females) participants 50-70 yr were assessed for weekly EEE level using the Yale Physical Activity Survey. Lifetime consistency of EEE was also determined. Subjects were recruited across a large range of EEE levels and separated into quartiles: 0-990, 991-2340, 2341-3540, and >3541 kcal x wk(-1). Relative telomere length and telomerase activity were measured in peripheral blood mononuclear cells (PBMC).

RESULTS

The second EEE quartile exhibited significantly longer telomere lengths [1.12 +/- 0.03 relative units (RU)] than both the first and fourth EEE quartiles (0.94 +/- 0.03 and 0.96 +/- 0.03 RU, respectively; P < 0.05) but was not different from the third quartile. Telomerase activity was not different among the EEE quartiles. An association was observed between telomerase enzyme activity and hTERT genotype with the TT genotype (1.0 x 10(-2) +/- 4.0 x 10(-3) attomoles (amol) per 10,000 cells; n = 19) having significantly greater telomerase enzyme activity than both the CT (1.3 x 10(-3) +/- 3.2 x 10(-3); n = 30) and CC groups (5.0 x 10(-4) +/- 3.9 x 10(-3); n = 20; P = 0.01).

CONCLUSION

These results indicate that moderate physical activity levels may provide a protective effect on PBMC telomere length compared with both low and high EEE levels.