Elevated hydrogen peroxide and decreased catalase and glutathione peroxidase protection are associated with aging sarcopenia

How soon do metabolic alterations and oxidative distress precede the reduction of muscle mass and strength in Wistar rats in aging process?

Here we investigate metabolic changes, the antioxidant system and the accumulation of oxidative damage in muscles with different fiber types during the aging process in Wistar rats and try to map how sooner the changes occur. To do so, 30 male Wistar rats were submitted to behavioral evaluation to determine voluntary strength in the 11, 15, and 19 month old rats, measuring the energy metabolism, antioxidant system, oxidative damage and structure in the soleus and extensor digitorum longus muscles. We detected structural and metabolic changes in both muscles, especially in the EDL of 15 month old rats and in the soleus of 19 month old rats. In the 15 month old rats, there was a reduction in the cross-sectional area of the fibers, and a reduction in the proportion of type I fibers, accompanied by an increase in fiber density and the amount of type IIA fibers. This change in the fiber profile was followed by an increase in the activity of anaerobic metabolism enzymes, suggesting a reduction in the oxidative capacity of the muscle. In addition, there was an increase in the rate of lipid peroxidation, accompanied by a reduced antioxidant capacity. In the 19 month old rats, these disturbances got stronger. In summary, the present study demonstrated that before functional disturbances, there was an accumulation of oxidative damage and structural changes in the skeletal muscle beginning at 15 months old in the EDL and the soleus only in the biochemical parameters. Therefore, the metabolic alterations occurred at 15 months old and not before.

Co-administration of resveratrol rescued lead-induced toxicity in Drosophila melanogaster

Lead toxicity poses a significant environmental concern linked to diverse health issues. This study explores the potential mitigating effects of resveratrol on lead-induced toxicity in Drosophila melanogaster. Adult fruit flies, aged three days, were orally exposed to lead (60 mg/L), Succimer (10 mg), and varying concentrations of resveratrol (50, 100, and 150 mg). The investigation encompassed the assessment of selected biological parameters, biochemical markers, oxidative stress indicators, and antioxidant enzymes. Resveratrol exhibited a dose-dependent enhancement of egg-laying, eclosion rate, filial generation output, locomotor activity, and life span in D. melanogaster, significantly to 150 mg of diet. Most of the investigated biochemical parameters were significantly rescued in lead-exposed fruit flies when co-treated with resveratrol (p < 0.05). However, oxidative stress remained unaffected by resveratrol. The findings suggest that resveratrol effectively protects against lead toxicity in Drosophila melanogaster and may hold therapeutic potential as an agent for managing lead poisoning in humans.

Association between oxidative balance score and sarcopenia in older adults

Sarcopenia is a progressive skeletal muscle disease in which oxidative stress has been proposed as one of the primary markers. The oxidative balance score (OBS) represents the oxidative balance of a person's dietary pattern using the merged intake of anti-oxidants and pro-oxidants. Therefore, the present study assessed the association between OBS and sarcopenia in Iranian older adults. In the current study, 80 people with sarcopenia and 80 without it were considered the case and control groups, respectively. All controls were matched by sex with cases. To confirm sarcopenia, skeletal muscle mass index (SMI), handgrip strength (HGS) measurement, and gait speed were used. Also, body composition was measured by bioelectrical impedance analysis (BIA). A valid and reliable food frequency questionnaire (FFQ) was used to assess all participants' dietary intake of pro-oxidants and anti-oxidants. Conditional logistic regression was applied to assess the association between OBS and sarcopenia. In the bivariate model, we observed lower odds of sarcopenia in the second and last tertile of OBS in comparison to the first tertile (T) (T2 - odds ratio (OR) = 0.414, 95% confidence interval (CI) : 0.186-0.918 and T3 - OR = 0.101, 95% CI: 0.041-0.248). After adjusting for potential confounders, the association was not significant in second and last tertile of OBS in comparision to the first one. The present study's findings demonstrated that overcoming exposure to anti-oxidants over pro-oxidants, as illustrated by a higher OBS, is not related to lower odds of sarcopenia in older adults.

5'-Cytimidine Monophosphate Ameliorates H2O2-Induced Muscular Atrophy in C2C12 Myotubes by Activating IRS-1/Akt/S6K Pathway

Age-related muscle atrophy (sarcopenia), characterized by reduced skeletal muscle mass and muscle strength, is becoming increasingly prevalent worldwide, which is especially true for older people, and can seriously damage health and quality of life in older adults. This study aims to investigate the beneficial effects of 5'-cytimidine monophosphate (CMP) on H2O2-induced muscular atrophy in C2C12 myotubes. C2C12 myotubes were treated with H2O2 in the presence and absence of CMP and the changes in the anti-oxidation, mitochondrial functions, and expression of sarcopenia-related proteins were observed. Immunofluorescence analysis showed that CMP significantly increased the diameter of myotubes. We found that CMP could increase the activity of antioxidant enzymes and improve mitochondrial dysfunction, as well as reduce inflammatory cytokine levels associated with sarcopenia. RNA-seq analysis showed that CMP could relieve insulin resistance and promote protein digestion and absorption. Western blot analysis further confirmed that CMP could promote the activation of the IRS-1/Akt/S6K signaling pathway and decrease the expression of MuRF1 and Atrogin-1, which are important markers of muscle atrophy. The above results suggest that CMP protects myotubes from H2O2-induced atrophy and that its potential mechanism is associated with activating the IRS-1/Akt/S6K pathway to promote protein synthesis by improving mitochondrial dysfunction and insulin resistance. These results indicate that CMP can improve aging-related sarcopenia.

Lemon extract reduces the hepatic oxidative stress and persulfidation levels by upregulating the Nrf2 and Trx1 expression in old rats

Citrus flavanones are recognized as promising bioactives within the concept of healthy aging. Thus, the present study investigated the effects of a nutritionally relevant dose of lemon extract (LE) on liver redox regulation and persulfidation levels in 24-month-old Wistar rats. LE (40 mg/kg b.m.) was administered orally once daily for 4 weeks. Control groups received either vehicle (sunflower oil) or remained intact. The applied methodology considered qPCR, Western blot, protein persulfidation levels evaluation, histochemistry in line with immunofluorescence, liver biochemical assays (glutathione, total -SH groups and malonaldehyde; MDA), liver enzymes in serum and in silico analysis to explore the potential interaction/binding between the proteins studied in the paper. Our results showed that LE increased glutathione peroxidase (GPx), reductase (GR), glutamate-cysteine ligase catalytic and modifier subunit, respectively, as well as Nrf2 gene expressions, but decreased the expression of superoxide dismutase 2 (SOD2). Upon LE application, protein expression showed upregulation of NRF2, SOD2, GPx, GR, and thioredoxin 1 (Trx1). LE significantly decreased the protein persulfidation levels and concentration of MDA, a marker of oxidative damage in the cell. Histological analysis showed a normal liver histoarchitecture without pathological changes, aligning with the normal serum level of hepatic enzymes. Obtained results showed that LE, by modulating hepatic redox regulators Nrf2 and Trx1, diminishes oxidative stress and alters the persulfidation levels, suggesting a considerable beneficial antioxidant potential of lemon flavanones in the old-aged liver.

The contribution of mitochondria to age-related skeletal muscle wasting: A sex-specific perspective

As people age, their skeletal muscle (SkM) experiences a decline in mitochondrial functionality and density, which leads to decreased energy production and increased generation of reactive oxygen species. This cascade of events, in turn, might determine the loss of SkM mass, strength and quality. Even though the mitochondrial processes dysregulated by aging, such as oxidative phosphorylation, mitophagy, antioxidant defenses and mtDNA transcription, are the same in both sexes, mitochondria age differently in the SkM of men and women. Indeed, the onset and magnitude of the impairment of these processes seem to be influenced by sex-specific factors. Sexual hormones play a pivotal role in the regulation of SkM mass through both genomic and non-genomic mechanisms. However, the precise mechanisms by which these hormones regulate mitochondrial plasticity in SkM are not fully understood. Although the presence of estrogen receptors in mitochondria is recognized, it remains unclear whether androgen receptors affect mitochondrial function. This comprehensive review critically dissects the current knowledge on the interplay of sex in the aging of SkM, focusing on the role of sex hormones and the corresponding signaling pathways in shaping mitochondrial plasticity. Improved knowledge on the sex dimorphism of mitochondrial aging may lead to sex-tailored interventions that target mitochondrial health, which could be effective in slowing or preventing age-related muscle loss.

Sarcopenia in a type 2 diabetic state: Reviewing literature on the pathological consequences of oxidative stress and inflammation beyond the neutralizing effect of intracellular antioxidants

Sarcopenia remains one of the major pathological features of type 2 diabetes (T2D), especially in older individuals. This condition describes gradual loss of muscle mass, strength, and function that reduces the overall vitality and fitness, leading to increased hospitalizations and even fatalities to those affected. Preclinical evidence indicates that dysregulated mitochondrial dynamics, together with impaired activity of the NADPH oxidase system, are the major sources of oxidative stress that drive skeletal muscle damage in T2D. While patients with T2D also display relatively higher levels of circulating inflammatory markers in the serum, including high sensitivity-C-reactive protein, interleukin-6, and tumor necrosis factor-α that are independently linked with the deterioration of muscle function and sarcopenia in T2D. In fact, beyond reporting on the pathological consequences of both oxidative stress and inflammation, the current review highlights the importance of strengthening intracellular antioxidant systems to preserve muscle mass, strength, and function in individuals with T2D.

Polarized Desmosome and Hemidesmosome Shedding via Small Extracellular Vesicles is an Early Indicator of Outer Blood-Retina Barrier Dysfunction

The retinal pigmented epithelium (RPE) constitutes the outer blood-retinal barrier, enables photoreceptor function of the eye, and is constantly exposed to oxidative stress. As such, dysfunction of the RPE underlies pathology leading to development of age-related macular degeneration (AMD), the leading cause of vision loss among the elderly in industrialized nations. A major responsibility of the RPE is to process photoreceptor outer segments, which relies on the proper functioning of its endocytic pathways and endosomal trafficking. Exosomes and other extracellular vesicles (EVs) from RPE are an essential part of these pathways and may be early indicators of cellular stress. To test the role of small EVs (sEVs) including exosomes, that may underlie the early stages of AMD, we used a polarized primary RPE cell culture model under chronic subtoxic oxidative stress. Unbiased proteomic analyses of highly purified basolateral sEVs from oxidatively stressed RPE cultures revealed changes in proteins involved in epithelial barrier integrity. There were also significant changes in proteins accumulating in the basal-side sub-RPE extracellular matrix during oxidative stress, that could be prevented with an inhibitor of sEV release. Thus, chronic subtoxic oxidative stress in primary RPE cultures induces changes in sEV content, including basal-side specific desmosome and hemidesmosome shedding via sEVs. These findings provide novel biomarkers of early cellular dysfunction and opportunity for therapeutic intervention in age-related retinal diseases (e.g., AMD).

Metallosis after Hip Arthroplasty Damages Skeletal Muscle: A Case Report

Good musculoskeletal quality dramatically influences the outcome of an arthroplasty operation in geriatric patients, as well as is a key element for optimal osseointegration. In this context, metallosis is a complication associated with the type of prosthesis used, as implants with a chromium-cobalt interface are known to alter the bone microarchitecture and reduce the ratio of muscle to fat, resulting in lipid accumulation. Therefore, the aim of our study was to investigate possible muscle changes by histological, morphometric, and immunohistochemical analyses in a patient undergoing hip replacement revision with elevated blood and urinary concentrations of chromium and cobalt. Interestingly, the muscle tissue showed significant structural changes and a massive infiltration of adipose tissue between muscle fibers in association with an altered expression pattern of important biomarkers of musculoskeletal health and oxidative stress, such as myostatin and NADPH Oxidase 4. Overall, our results confirm the very serious impact of metallosis on musculoskeletal health, suggesting the need for further studies to adopt a diagnostic approach to identify the cause of metallosis early and eliminate it as part of the prosthesis revision surgery.

Chronic Intermittent Hypoxia-Induced Diaphragm Muscle Weakness Is NADPH Oxidase-2 Dependent

Chronic intermittent hypoxia (CIH)-induced redox alterations underlie diaphragm muscle dysfunction. We sought to establish if NADPH oxidase 2 (NOX2)-derived reactive oxygen species (ROS) underpin CIH-induced changes in diaphragm muscle, which manifest as impaired muscle performance. Adult male mice (C57BL/6J) were assigned to one of three groups: normoxic controls (sham); chronic intermittent hypoxia-exposed (CIH, 12 cycles/hour, 8 h/day for 14 days); and CIH + apocynin (NOX2 inhibitor, 2 mM) administered in the drinking water throughout exposure to CIH. In separate studies, we examined sham and CIH-exposed NOX2-null mice (B6.129S-Cybb^TM1Din/J). Apocynin co-treatment or NOX2 deletion proved efficacious in entirely preventing diaphragm muscle dysfunction following exposure to CIH. Exposure to CIH had no effect on NOX2 expression. However, NOX4 mRNA expression was increased following exposure to CIH in wild-type and NOX2 null mice. There was no evidence of overt CIH-induced oxidative stress. A NOX2-dependent increase in genes related to muscle regeneration, antioxidant capacity, and autophagy and atrophy was evident following exposure to CIH. We suggest that NOX-dependent CIH-induced diaphragm muscle weakness has the potential to affect ventilatory and non-ventilatory performance of the respiratory system. Therapeutic strategies employing NOX2 blockade may function as an adjunct therapy to improve diaphragm muscle performance and reduce disease burden in diseases characterised by exposure to CIH, such as obstructive sleep apnoea.

Advances in exercise to alleviate sarcopenia in older adults by improving mitochondrial dysfunction

Sarcopenia is a chronic degenerative disease affecting primarily older adults. A growing aging population is gradually increasing the number of patients suffering from sarcopenia, placing increasing financial pressure on patients' families and society in general. There is a strong link between mitochondrial dysfunction and sarcopenia pathogenesis. As a result, treating sarcopenia by improving mitochondrial dysfunction is an effective strategy. Numerous studies have demonstrated that exercise has a positive effect on mitochondrial dysfunction when treating sarcopenia. Exercise promotes mitochondrial biogenesis and mitochondrial fusion/division to add new mitochondria or improve dysfunctional mitochondria while maintaining mitochondrial calcium homeostasis, mitochondrial antioxidant defense system, and mitochondrial autophagy to promote normal mitochondrial function. Furthermore, exercise can reduce mitochondrial damage caused by aging by inhibiting mitochondrial oxidative stress, mitochondrial DNA damage, and mitochondrial apoptosis. Exercise effectiveness depends on several factors, including exercise duration, exercise intensity, and exercise form. Therefore, Moderate-intensity exercise over 4 weeks potentially mitigates sarcopenia in older adults by ameliorating mitochondrial dysfunction. HIIT has demonstrated potential as a viable approach to addressing sarcopenia in aged rats. However, further investigation is required to validate its efficacy in treating sarcopenia in older adults.

Comparative Proteomics Analysis of Pig Muscle Exudate through Label-Free Liquid Chromatography-Mass Spectrometry

Capital-driven animal husbandry systems undertaken in the last century led to the abandoning of many pig breeds that were not profitable. These local pig breeds and their respective production systems have great potential as they are able to respond to the high criteria and needs of modern society concerning some environmental aspects, animal-welfare, healthiness, etc. This is the case of the black pigs of Italy. The Apulo-Calabrese is a breed of black pig, known by many other names such as Nero d'Abruzzo. In order to further understand the biological differences between different types of porcine genetics (Nero d'Abruzzo and commercial-hybrid) we used a label-free LC-MS strategy and Western-blot to characterize the proteomes of muscle-exudate collected from these pigs. This proteomics approach identified 1669 proteins of which 100 changed significantly in abundance between breeds. Bioinformatics functional analysis indicated that differentially expressed proteins were involved in several biological processes related to energy-metabolism and response to oxidative stress, suggesting that these functions might distinguish between these pigs. Fatty-acid synthase, catalase and glutathione-peroxidase, involved in enzymatic activity were found to be more represented in samples obtained from the Nero d'Abruzzo. This biological information can potentially provide new biological factors that could determine the different production performances of these pigs, distinguished by their different genetic backgrounds.

Compromised conformation and kinetics of catalase in the presence of propylthiouracil: A biophysical study and alleviation by curcumin

In the present study, the inhibitory effect of propylthiouracil (PTU) on bovine liver catalase (BLC) activity was studied in the presence of curcumin (CUR). The results suggest that the PTU-induced decrease in BLC activity was caused by a change in conformation of BLC with reduced α-helical content and decrease in zeta potential. Nevertheless, temperature-dependent activation of CUR protects the activity of BLC by restoring the secondary conformation and zeta potential of BLC. CUR inhibited the time-induced reduction in BLC activity and the protection was increased with increasing concentrations of CUR and found to be significant even from 1:0.1 molar ratios. The enzyme kinetics confirmed the high catalytic efficiency of BLC in presence of CUR than PTU. The protective role of CUR was due to the formation of a more stabilized complex as demonstrated by molecular docking, and fourier-transform infrared study. Isothermal titration calorimetric study supports for a favourable reaction between BLC and PTU or CUR due to the negative ΔH, and positive TΔS. Although the number of binding sites for PTU and CUR was found to be 10 and 7, respectively, the binding affinity between CUR and BLC is approximately 3.72 fold stronger than BLC-PTU complex. The increased melting temperature of BLC was noticed in presence of CUR suggesting the protective potential of CUR towards biomolecules. Indeed, this is the first biophysical study to describe the molecular mechanism of PTU-induced reduction in BLC activity and alleviation by CUR with detail kinetics. Thus, CUR can be further extended to other antioxidant enzymes or compromised biomolecules for therapeutic interventions.

The role of resistance training and creatine supplementation on oxidative stress, antioxidant defense, muscle strength, and quality of life in older adults

Background

The aim of this study was to evaluate the effect of resistance training (RT) with creatine monohydrate supplementation (CS) on serum levels of 8-hydroxydeoxyguanosine (8-OHdG), malondialdehyde (MDA), glutathione peroxidase (GPX), and total antioxidant capacity (TAC) in older adults.

Objectives

This study evaluated the effect of resistance training with creatine monohydrate supplementation on oxidative stress and antioxidant defense, muscle strength and quality of life in older adults.

Methods

We examined 45 non-athlete volunteer older men and women (mean, 68.1 ± 7.2  years old), were randomly selected and divided into three groups of 15: RT with creatine supplementation (RT + CS), RT with placebo (RT + P) and control group. RT protocol was performed for 10  weeks, three sessions per week. Creatine supplement was taken daily at a dose of 0.1 g/kg of body weight, while the placebo group consumed the same amount of starch. Fasting blood samples were taken before the start of program and at the end of the RT period.

Results

In the training groups, after 10  weeks of RT, a significant decrease in MDA and 8 - OHDG as well as a significant increase in serum levels of GPX and TAC were observed (in all cases, p =  0.001). In addition, creatinine levels were enhanced in the RT + CS (p =  0.014). Training intervention also improved quality of life and muscle strength in the experimental groups (p =  0.001), although muscle strength changes were more visible in the RT + CS group than in the RT + P group (p <  0/05).

Conclusion

Regular resistance training can be recommended as a very suitable non-pharmacological approach to strengthen the body's antioxidant system, muscle strength and quality of life in older adults. There are no definite findings on the role of creatine on the antioxidant system and quality of life in older adults, but the use of this supplement in addition to RT can double the amount of strength gained from resistance training.

Exercise and mitochondrial mechanisms in patients with sarcopenia

Sarcopenia is a severe loss of muscle mass and functional decline during aging that can lead to reduced quality of life, limited patient independence, and increased risk of falls. The causes of sarcopenia include inactivity, oxidant production, reduction of antioxidant defense, disruption of mitochondrial activity, disruption of mitophagy, and change in mitochondrial biogenesis. There is evidence that mitochondrial dysfunction is an important cause of sarcopenia. Oxidative stress and reduction of antioxidant defenses in mitochondria form a vicious cycle that leads to the intensification of mitochondrial separation, suppression of mitochondrial fusion/fission, inhibition of electron transport chain, reduction of ATP production, an increase of mitochondrial DNA damage, and mitochondrial biogenesis disorder. On the other hand, exercise adds to the healthy mitochondrial network by increasing markers of mitochondrial fusion and fission, and transforms defective mitochondria into efficient mitochondria. Sarcopenia also leads to a decrease in mitochondrial dynamics, mitophagy markers, and mitochondrial network efficiency by increasing the level of ROS and apoptosis. In contrast, exercise increases mitochondrial biogenesis by activating genes affected by PGC1-ɑ (such as CaMK, AMPK, MAPKs) and altering cellular calcium, ATP-AMP ratio, and cellular stress. Activation of PGC1-ɑ also regulates transcription factors (such as TFAM, MEFs, and NRFs) and leads to the formation of new mitochondrial networks. Hence, moderate-intensity exercise can be used as a non-invasive treatment for sarcopenia by activating pathways that regulate the mitochondrial network in skeletal muscle.

Catalase-deficient mice induce aging faster through lysosomal dysfunction

BACKGROUND

Lysosomes are a central hub for cellular metabolism and are involved in the regulation of cell homeostasis through the degradation or recycling of unwanted or dysfunctional organelles through the autophagy pathway. Catalase, a peroxisomal enzyme, plays an important role in cellular antioxidant defense by decomposing hydrogen peroxide into water and oxygen. In accordance with pleiotropic significance, both impaired lysosomes and catalase have been linked to many age-related pathologies with a decline in lifespan. Aging is characterized by progressive accumulation of macromolecular damage and the production of high levels of reactive oxygen species. Although lysosomes degrade the most long-lived proteins and organelles via the autophagic pathway, the role of lysosomes and their effect on catalase during aging is not known. The present study investigated the role of catalase and lysosomal function in catalase-knockout (KO) mice.

METHODS

We performed experiments on WT and catalase KO younger (9 weeks) and mature adult (53 weeks) male mice and Mouse embryonic fibroblasts isolated from WT and KO mice from E13.5 embryos as in vivo and in ex-vivo respectively. Mouse phenotyping studies were performed with controls, and a minimum of two independent experiments were performed with more than five mice in each group.

RESULTS

We found that at the age of 53 weeks (mature adult), catalase-KO mice exhibited an aging phenotype faster than wild-type (WT) mice. We also found that mature adult catalase-KO mice induced leaky lysosome by progressive accumulation of lysosomal content, such as cathespin D, into the cytosol. Leaky lysosomes inhibited autophagosome formation and triggered impaired autophagy. The dysregulation of autophagy triggered mTORC1 (mechanistic target of rapamycin complex 1) activation. However, the antioxidant N-acetyl-L-cysteine and mTORC1 inhibitor rapamycin rescued leaky lysosomes and aging phenotypes in catalase-deficient mature adult mice.

CONCLUSIONS

This study unveils the new role of catalase and its role in lysosomal function during aging. Video abstract.

A Label-Free Quantitative Analysis for the Search of Proteomic Differences between Goat Breeds

The intensification and standardization of livestock farming are causing a decline in the number of animal breeds in many species, such as the goat. The availability of more studies on the potentiality of goat breeds could raise awareness of their importance, conservation and productive possibilities. Label-free quantitative analysis was applied in this study to investigate the proteomic differences between the autochthon Teramana and Saanen goats that could be useful for defining peculiar features of these breeds. A total of 2093 proteins were characterized in the muscle exudate proteome of the Teramana and Saanen breeds. A total of 41 proteins clearly separated the two breeds. Eukaryotic initiation factor proteins and aldehyde-dehydrogenase 7 family-member A1 were up-regulated in the autochthon breed and associated with its resilience, whereas catalase was down-regulated and associated with lower muscular mass. This study is the most detailed report of goat muscle proteome. Several differentially regulated proteins between the two breeds were identified, providing insights into functional pathways that define this organism and its biology.

Resistance Training Modulates Reticulum Endoplasmic Stress, Independent of Oxidative and Inflammatory Responses, in Elderly People

Aging is related to changes in the redox status, low-grade inflammation, and decreased endoplasmic reticulum unfolded protein response (UPR). Exercise has been shown to regulate the inflammatory response, balance redox homeostasis, and ameliorate the UPR. This work aimed to investigate the effects of resistance training on changes in the UPR, oxidative status, and inflammatory responses in peripheral blood mononuclear cells of elderly subjects. Thirty elderly subjects volunteered to participate in an 8-week resistance training program, and 11 youth subjects were included for basal assessments. Klotho, heat shock protein 60 (HSP60), oxidative marker expression (catalase, glutathione, lipid peroxidation, nuclear factor erythroid 2-related factor 2, protein carbonyls, reactive oxygen species, and superoxide dismutase 1 and 2), the IRE1 arm of UPR, and TLR4/TRAF6/pIRAK1 pathway activation were evaluated before and following training. No changes in the HSP60 and Klotho protein content, oxidative status markers, and TLR4/TRAF6/pIRAK1 pathway activation were found with exercise. However, an attenuation of the reduced pIRE1/IRE1 ratio was observed following training. Systems biology analysis showed that a low number of proteins (RPS27A, SYVN1, HSPA5, and XBP1) are associated with IRE1, where XBP1 and RPS27A are essential nodes according to the centrality analysis. Additionally, a gene ontology analysis confirms that endoplasmic reticulum stress is a key mechanism modulated by IRE1. These findings might partially support the modulatory effect of resistance training on the endoplasmic reticulum in the elderly.

Skeletal muscle oxidative stress and inflammation in aging: Focus on antioxidant and anti-inflammatory therapy

With aging, the progressive loss of skeletal muscle will have negative effect on multiple physiological parameters, such as exercise, respiration, thermoregulation, and metabolic homeostasis. Accumulating evidence reveals that oxidative stress and inflammation are the main pathological characteristics of skeletal muscle during aging. Here, we focus on aging-related sarcopenia, summarize the relationship between aging and sarcopenia, and elaborate on aging-mediated oxidative stress and oxidative damage in skeletal muscle and its critical role in the occurrence and development of sarcopenia. In addition, we discuss the production of excessive reactive oxygen species in aging skeletal muscle, which reduces the ability of skeletal muscle satellite cells to participate in muscle regeneration, and analyze the potential molecular mechanism of ROS-mediated mitochondrial dysfunction in aging skeletal muscle. Furthermore, we have also paid extensive attention to the possibility and potential regulatory pathways of skeletal muscle aging and oxidative stress mediate inflammation. Finally, in response to the abnormal activity of oxidative stress and inflammation during aging, we summarize several potential antioxidant and anti-inflammatory strategies for the treatment of sarcopenia, which may provide beneficial help for improving sarcopenia during aging.

Ranolazine Counteracts Strength Impairment and Oxidative Stress in Aged Sarcopenic Mice

Sarcopenia is defined as the loss of muscle mass associated with reduced strength leading to poor quality of life in elderly people. The decline of skeletal muscle performance is characterized by bioenergetic impairment and severe oxidative stress, and does not always strictly correlate with muscle mass loss. We chose to investigate the ability of the metabolic modulator Ranolazine to counteract skeletal muscle dysfunctions that occur with aging. For this purpose, we treated aged C57BL/6 mice with Ranolazine/vehicle for 14 days and collected the tibialis anterior and gastrocnemius muscles for histological and gene expression analyses, respectively. We found that Ranolazine treatment significantly increased the muscle strength of aged mice. At the histological level, we found an increase in centrally nucleated fibers associated with an up-regulation of genes encoding MyoD, Periostin and Osteopontin, thus suggesting a remodeling of the muscle even in the absence of physical exercise. Notably, these beneficial effects of Ranolazine were also accompanied by an up-regulation of antioxidant and mitochondrial genes as well as of NADH-dehydrogenase activity, together with a more efficient protection from oxidative damage in the skeletal muscle. These data indicate that the protection of muscle from oxidative stress by Ranolazine might represent a valuable approach to increase skeletal muscle strength in elderly populations.

Targeted Plasmalogen Supplementation: Effects on Blood Plasmalogens, Oxidative Stress Biomarkers, Cognition, and Mobility in Cognitively Impaired Persons

Plasmalogens are a specific type of glycerophospholipid found in especially high levels in neuronal membranes. Decreased blood and brain levels of docosahexaenoic acid (DHA) containing plasmalogens are associated with decreased cognition and neuromuscular function in humans. Administration of 1-O-alkyl-2-acylglycerol (AAG) plasmalogen precursors containing DHA at the sn-2 position dose-dependently increase blood DHA plasmalogens and are neuroprotective in animal models of neurodegeneration at doses between 10 and 50 mg/kg. We conducted an investigational clinical trial in 22 cognitively impaired persons to evaluate the effects of an escalating oral dosing regimen of DHA-AAG from 900 to 3,600 mg/day over a 4-month period on blood serum plasmalogen and non-plasmalogen phospholipids and oxidative stress biomarkers. Safety, tolerability and therapeutic effects on cognition and mobility were also evaluated. DHA plasmalogen levels increased with increasing dose and remained significantly elevated at all treatment doses and durations. DHA plasmalogen levels were positively associated with catalase activity and negatively associated with malondialdehyde (MDA) levels. DHA-AAG supplementation normalized catalase activity in persons with low baseline catalase activity, normalized MDA levels in persons with high baseline MDA levels, and normalized superoxide dismutase activity in persons with high baseline SOD activity. Cognition improved in nine participants, was unchanged in nine, and declined in four. Mobility improved in twelve, was unchanged in five and declined in four participants. Changes in cognition and mobility were statistically significant versus a random outcome. Baseline DHA-plasmalogen levels were not predictive of clinical response. DHA-AAG was well tolerated at all dosages and no adverse reactions were observed.

Assessment of deep eutectic solvents toxicity in zebrafish (Danio rerio)

Deep Eutectic Systems (DES) have emerged as a "green alternative" to organic solvents and have been coined as biocompatible and biodegradable. However, the number of studies concerning the real biodegradability and biocompatibility are scarce. Thus, to study the toxicity of certain DES, two different approaches were used: i) zebrafish exposure via water, where the system (DES) was tested at potentially realistic environmental concentrations and ii) via intraperitoneal injection, where the system was tested in different concentrations, relevant to the pharmaceutical industry. These studies were performed using zebrafish, a standardized animal model often used in biomedicine and toxicological assays. The results show low toxicity according to tested concentrations (up to 73.47 μM), when the system CA:T:W, with a 2:1:3 molar ratio, was tested through exposure via water and also in the intraperitoneal injection tests with concentrations up to 6000 μM. The activity of different enzymes involved in antioxidant pathways (glutathione S-transferase, catalase, glutathione peroxidase), the total antioxidant capacity (TAC) and lipoperoxidation (MDA content) were determined suggesting low toxicity of the tested system (DES). The promising results herein presented show that DES present the potential to be used as the new class of green solvents, not only for use in the pharmaceutical industry, but also in cosmetic and chemical engineering processes without causing negative impact on living organisms.

Benzo[a]pyrene exposure in muscle triggers sarcopenia through aryl hydrocarbon receptor-mediated reactive oxygen species production

BACKGROUND

Benzo[a]pyrene (BaP), a toxic carcinogen, is associated with various adverse effects but is rarely discussed in muscle-related disorders. This study investigated in vitro and in vivo effects triggered by BaP exposure in muscles and hypothesized that exposure might induce conditions similar to sarcopenia due to the shared mechanism of oxidative stress. In vitro experiments used C2C12 mouse myoblasts to examine effects induced by BaP exposure in control (untreated) and BaP-treated (10 µM/ml) muscle cells. An established TNF-α-treated sarcopenia model was utilized to verify our results. In vivo experiments compared immunohistochemical staining of sarcopenia-related markers in rats exposed to clean air and polluted air.

RESULTS

In C2C12 cells, after 2-72 h of BaP exposure, elevated mRNA and protein expressions were observed in aryl hydrocarbon receptor (AhR) and cytochrome P450 1A1, subsequently in ROS (NOX2 and NOX4) production, inflammatory cytokines (IL-6, TNF-α, and NF-kB), and proteins mediating apoptotic cell death (caspase-3 and PARP). Two myokines also altered mRNA and protein expressions akin to changes in sarcopenia, namely decreased irisin levels and increased myostatin levels. In addition, N-acetylcysteine, a well-known antioxidant, led to decrease in oxidative markers induced by BaP. The validation by TNF-α-treated sarcopenia model revealed comparable biological responses in either TNF-α or BaP treated C2C12 cells. In vivo experiments with rats exposed to air pollution showed increased expression of BaP, AhR, 8-hydroxydeoxyguanosine, and myostatin and decreased irisin expression in immunohistochemical staining.

CONCLUSIONS

Our results suggest that BaP exerts deleterious effects on the muscle, leading to conditions indicative of sarcopenia. Antioxidant supplementation may be a treatment option for BaP-induced sarcopenia, but further validation studies are needed.

Effect of 32-Weeks High-Intensity Interval Training and Resistance Training on Delaying Sarcopenia: Focus on Endogenous Apoptosis

Sarcopenia caused by aging is an important factor leading to a decline in the quality of life of older people. Apoptosis in muscle atrophy accelerates the process of muscle loss in older populations. The present study aimed to investigate the effects of 32 weeks of high-intensity interval training (HIIT) and resistance training (RT) on the skeletal muscle-related indices and provide a theoretical basis for regulating the mitochondrial-mediated pathway to delay sarcopenia. We randomly selected 10 from eight-month-old male SD rats (N = 130) as the baseline group; after 1 week of adaptive feeding, the rats were sacrificed. The remaining rats were randomly assigned to one of three groups: control group (C, N = 40, natural aging for 32 weeks), HIIT group (H, N = 40, performed six loops of 3 min at 90% and 3 min at 50% VO2 max speed treadmill running, with 5 min at 70% VO2 max speed at the beginning and the end of the training, 3 times a week for 32 weeks), and resistance group (R, n = 40, 46 min per day, 3 days per week, with a 30% maximum load on a treadmill with a slope of 35°, 15 m/min). The soleus muscles were collected for analysis at baseline and every 8 weeks. Aging resulted in decreased soleus muscle mass and Bcl-2 levels in the mitochondria, while the levels of reactive oxygen species (ROS) and Bax did not change. HIIT reversed the age-associated activation of pro-apoptotic processes, but RT did not. In addition, when rats were aged from 8 to 16 months, the level of Cyt-C did not change, the Caspase-9 levels and Caspase-3 levels decreased gradually in the soleus muscles, the rats of both the HIIT and RT groups had these indices decreased at 32 weeks. The results suggest that the age-associated loss of muscle mass was reversed by training, and the effect of RT was better than that of HIIT. Both the HIIT and RT rats showed a decrease in the apoptosis of skeletal muscle cells after 32 weeks of intervention. HIIT performed better for long-term intervention regarding the pro-apoptotic factors. This study warranted further research to delineate the underlying mechanism of effects of different exercise methods on the changes of aging skeletal muscle at in vivo level.

Antioxidant Properties of Salvia officinalis Decoction Extract and Mechanism of Its Protective Effects on Ethanol-Induced Liver and Kidney Injuries

This study assessed the hepato- and nephroprotective effects of Salvia officinalis flowers decoction extract (SODE) against ethanol (EtOH)-induced oxidative stress in rats as well as the possible mechanism implicated in such protection. Animals were divided into four groups: control, EtOH, and EtOH+SODE. Wistar rats were pretreated with SODE (50, 100, and 200 mg/kg, body weight [b.w.], p.o.) for 15 days and intoxicated during 2 h by acute oral administration of EtOH (4 g/kg, b.w.) 60 min after the last dose of SODE. We found that SODE pretreatment, in vivo, protected against EtOH-induced liver and kidney injuries evident by plasma transaminases activity and preservation of the hepatic tissue structure. Compared with the control group, the animals treated with the SODE showed a significant decrease (68.81 ± 6.89-50.65 ± 3.97 UI/L) of alanine aminotransferase (ALT) and aspartate aminotransferase (AST; 144.38 ± 6.58-113.64 ± 8.03 UI/L) in a dose-dependent manner. By contrast, the plant extract significantly and dose dependently increased (0.175 ± 0.077-0.302 ± 0.011 mmol/L) the uric acid. The SODE counteracted EtOH-induced liver and kidney lipoperoxidation, preserved sulfhydryl groups (-SH) and glutathione reduced (GSH) contents. Our extract prevented the depletion of antioxidant enzyme activities such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). We also showed that acute alcohol administration increased tissue and plasma hydrogen peroxide (H₂O₂), calcium and free iron levels. Of interest, SODE pretreatment reversed all EtOH-induced disturbances in intracellular mediators. More importantly, SODE treatment significantly protected against alcohol-induced inflammation by reducing C-reactive protein (CRP) and alkaline phosphatase (ALP) activities in plasma. It was concluded that the SODE exerted a potential protective effect against EtOH-induced inflammation and oxidative stress in the rat organs. This study recommends that the consumption of sage flowers is useful for patients who suffer from hepato- and nephrotoxicity.

From the Bench to the Bedside: Branched Amino Acid and Micronutrient Strategies to Improve Mitochondrial Dysfunction Leading to Sarcopenia

With extended life expectancy, the older population is constantly increasing, and consequently, so too is the prevalence of age-related disorders. Sarcopenia, the pathological age-related loss of muscle mass and function; and malnutrition, the imbalance in nutrient intake and resultant energy production, are both commonly occurring conditions in old adults. Altered nutrition plays a crucial role in the onset of sarcopenia, and both these disorders are associated with detrimental consequences for patients (e.g., frailty, morbidity, and mortality) and society (e.g., healthcare costs). Importantly, sarcopenia and malnutrition also share critical molecular alterations, such as mitochondrial dysfunction, increased oxidative stress, and a chronic state of low grade and sterile inflammation, defined as inflammageing. Given the connection between malnutrition and sarcopenia, nutritional interventions capable of affecting mitochondrial health and correcting inflammageing are emerging as possible strategies to target sarcopenia. Here, we discuss mitochondrial dysfunction, oxidative stress, and inflammageing as key features leading to sarcopenia. Moreover, we examine the effects of some branched amino acids, omega-3 PUFA, and selected micronutrients on these pathways, and their potential role in modulating sarcopenia, warranting further clinical investigation.

Are oxidative stress biomarkers and respiratory muscles strength associated with COPD-related sarcopenia in older adults?

BACKGROUND

Patients with chronic obstructive pulmonary disease (COPD) often present with sarcopenia, a condition marked by the loss in quality and quantity of muscle mass that can affect the strength of respiratory muscles. COPD and sarcopenia are also independently associated with oxidative stress. This study aimed to investigate whether oxidative stress biomarkers and respiratory muscle strength are associated with sarcopenia in COPD patients.

METHODS

In a cross-sectional study, 86 elderly subjects, including subjects with and without COPD were assessed for body composition, maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) and oxidative stress parameters [substances reactive to thiobarbituric acid (TBARS), ferric reducing ability of plasma (FRAP), superoxide dismutase (SOD), and catalase (CAT)].

RESULTS

The sample was mainly composed by males (72.1%) and eutrophic subjects. COPD-related sarcopenia was evidenced in 51.1% (22/43) of subjects with COPD. The highest TBARS and CAT, and lower MIP and MEP were associated with a high probability of having COPD-related sarcopenia. In the multivariate analysis, TBARS (OR: 4.89, 95% CI 1.52 to 15.54, p = 0.006), CAT (OR: 1.22, 95% CI 1.03 to 1.45, p = 0.020) and MEP (OR: 0.97, 95% CI 0.95 to 0.99, p = 0.020) were independent determinants of COPD-related sarcopenia.

CONCLUSION

The increase in oxidative stress-related factors and the reduction of respiratory muscle strength are associated with COPD-related sarcopenia.

Redox Signaling and Sarcopenia: Searching for the Primary Suspect

Sarcopenia, the age-related decline in muscle mass and function, derives from multiple etiological mechanisms. Accumulative research suggests that reactive oxygen species (ROS) generation plays a critical role in the development of this pathophysiological disorder. In this communication, we review the various signaling pathways that control muscle metabolic and functional integrity such as protein turnover, cell death and regeneration, inflammation, organismic damage, and metabolic functions. Although no single pathway can be identified as the most crucial factor that causes sarcopenia, age-associated dysregulation of redox signaling appears to underlie many deteriorations at physiological, subcellular, and molecular levels. Furthermore, discord of mitochondrial homeostasis with aging affects most observed problems and requires our attention. The search for the primary suspect of the fundamental mechanism for sarcopenia will likely take more intense research for the secret of this health hazard to the elderly to be unlocked.

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.

Sarcopenia and serum biomarkers of oxidative stress after a 6-month physical activity intervention in women with metastatic breast cancer: results from the ABLE feasibility trial

Purpose

Sarcopenia has been identified as an important prognostic factor for patients with cancer. This study aimed at exploring the potential associations between a 6-month physical activity intervention and muscle characteristics, sarcopenia, oxidative stress and toxicities in patients with metastatic breast cancer.

Methods

Women newly diagnosed with metastatic breast cancer (N = 49) participated in an unsupervised, personalized, 6-month physical activity intervention with activity tracker. Computerized tomography images at the third lumbar vertebra were analysed at baseline, three months and six months to assess sarcopenia (muscle mass index < 40 cm²/m²) and muscle quality (poor if muscle attenuation < 37.8 Hounsfield Units). Oxidative markers included plasma antioxidant enzymes (catalase, glutathione peroxidase and superoxide dismutase activities), prooxidant enzymes (NADPH oxidase and myeloperoxidase activities) and oxidative stress damage markers (advanced oxidation protein products, malondialdehyde (MDA) and DNA oxidation.

Results

At baseline 53% (mean age 55 years (SD 10.41)) were sarcopenic and 75% had poor muscle quality. Muscle cross sectional area, skeletal muscle radiodensity, lean body mass remained constant over the six months (p = 0.75, p = 0.07 and p = 0.75 respectively), but differed significantly between sarcopenic and non-sarcopenic patients at baseline and 6-months. Sarcopenic patients at baseline were more likely to have an increase of MDA (p = 0.02) at 6 months. Being sarcopenic during at least one moment during the 6-month study was associated with a higher risk of developing severe toxicities (grade > 2) (p = 0.02).

Conclusions

This study suggests potential benefits of physical activity for maintenance of muscle mass. Sarcopenia can alter many parameters and disturb the pro and antioxidant balance.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10549-021-06238-z.

The ketogenic diet preserves skeletal muscle with aging in mice

The causes of the decline in skeletal muscle mass and function with age, known as sarcopenia, are poorly understood. Nutrition (calorie restriction) interventions impact many cellular processes and increase lifespan and preserve muscle mass and function with age. As we previously observed an increase in life span and muscle function in aging mice on a ketogenic diet (KD), we aimed to investigate the effect of a KD on the maintenance of skeletal muscle mass with age and the potential molecular mechanisms of this action. Twelve‐month‐old mice were assigned to an isocaloric control or KD until 16 or 26 months of age, at which time skeletal muscle was collected for evaluating mass, morphology, and biochemical properties. Skeletal muscle mass was significantly greater at 26 months in the gastrocnemius of mice on the KD. This result in KD mice was associated with a shift in fiber type from type IIb to IIa fibers and a range of molecular parameters including increased markers of NMJ remodeling, mitochondrial biogenesis, oxidative metabolism, and antioxidant capacity, while decreasing endoplasmic reticulum (ER) stress, protein synthesis, and proteasome activity. Overall, this study shows the effectiveness of a long‐term KD in mitigating sarcopenia. The diet preferentially preserved oxidative muscle fibers and improved mitochondrial and antioxidant capacity. These adaptations may result in a healthier cellular environment, decreasing oxidative and ER stress resulting in less protein turnover. These shifts allow mice to better maintain muscle mass and function with age.

Mitochondria Homeostasis and Oxidant/Antioxidant Balance in Skeletal Muscle-Do Myokines Play a Role?

Mitochondria are the cellular powerhouses that generate adenosine triphosphate (ATP) to substantiate various biochemical activities. Instead of being a static intracellular structure, they are dynamic organelles that perform constant structural and functional remodeling in response to different metabolic stresses. In situations that require a high ATP supply, new mitochondria are assembled (mitochondrial biogenesis) or formed by fusing the existing mitochondria (mitochondrial fusion) to maximize the oxidative capacity. On the other hand, nutrient overload may produce detrimental metabolites such as reactive oxidative species (ROS) that wreck the organelle, leading to the split of damaged mitochondria (mitofission) for clearance (mitophagy). These vital processes are tightly regulated by a sophisticated quality control system involving energy sensing, intracellular membrane interaction, autophagy, and proteasomal degradation to optimize the number of healthy mitochondria. The effective mitochondrial surveillance is particularly important to skeletal muscle fitness because of its large tissue mass as well as its high metabolic activities for supporting the intensive myofiber contractility. Indeed, the failure of the mitochondrial quality control system in skeletal muscle is associated with diseases such as insulin resistance, aging, and muscle wasting. While the mitochondrial dynamics in cells are believed to be intrinsically controlled by the energy content and nutrient availability, other upstream regulators such as hormonal signals from distal organs or factors generated by the muscle itself may also play a critical role. It is now clear that skeletal muscle actively participates in systemic energy homeostasis via producing hundreds of myokines. Acting either as autocrine/paracrine or circulating hormones to crosstalk with other organs, these secretory myokines regulate a large number of physiological activities including insulin sensitivity, fuel utilization, cell differentiation, and appetite behavior. In this article, we will review the mechanism of myokines in mitochondrial quality control and ROS balance, and discuss their translational potential.

Age-related alteration in HNE elimination enzymes

4-hydroxynonenal (HNE, 4-hydroxy-2-nonenal) is a primary α,β-unsaturated aldehyde product of lipid peroxidation. The accumulation of HNE increases with aging and the mechanisms are mainly attributable to increased oxidative stress and decreased capacity of HNE elimination. In this review article, we summarize the studies on age-related change of HNE concentration and alteration of HNE metabolizing enzymes (GCL, GST, ALDHs, aldose reductase, and 20S-proteasome), and discuss potential mechanism of age-related decrease in HNE-elimination capacity by focusing on Nrf2 redox signaling.

Effect of high-intensity resistance exercise on cardiometabolic health in older men with osteosarcopenia: the randomised controlled Franconian Osteopenia and Sarcopenia Trial (FrOST)

OBJECTIVES

Sarcopenia is related to the metabolic syndrome (MetS), a cluster of cardiometabolic risk-factors (CRF). Most exercise trials apply aerobic rather than resistance exercise to address CRF, while the strategy for maintaining muscle and bone is the opposite. However, there is considerable evidence that resistance exercise positively affects CRF. In the present study, we determined the effect of high-intensity resistance exercise training (HIT-RT) on CRF represented by the MetS in older men.

METHODS

Forty-three osteosarcopenic and predominately obese older men (>72 years) living independently in Erlangen-Nürnberg, Germany were randomly assigned to two study arms. The HIT-RT group (n=21) conducted a periodised high intensity/effort protocol dedicated to muscle and bone mass and function two times per week, while the control group (CG: n=22) maintained their habitual physical activities. Both groups were supplemented with protein, cholecalciferol and calcium. Study outcomes presented here were the MetS-Z (MetSZ) score and its underlying risk-factors.

RESULTS

After 18 months of intervention, we observed significant effects for the MetSZ score (p<0.001), with significant improvements in the HIT-RT and significant worsening in the CG. In detail, all parameters constituting the MetS contributed to this result, however, only waist-circumference, HDL-cholesterol and mean arterial blood pressure revealed significant effects. No adverse events were reported and high adherence was determined for the HIT-RT-protocol.

CONCLUSION

Continuously supervised HIT-RT is an effective, attractive, feasible and safe method to address cardiometabolic risk factors in community-dwelling men aged 72 years and older. Further, considering the proven effects on musculoskeletal risk factors, the present results indicate a more prominent role for HIT-RT within non-pharmacological prevention strategies of older adults.

TRIAL REGISTRATION NUMBER

NCT03453463.

Effects of High-Intensity Resistance Training on Osteopenia and Sarcopenia Parameters in Older Men with Osteosarcopenia-One-Year Results of the Randomized Controlled Franconian Osteopenia and Sarcopenia Trial (FrOST)

Dynamic resistance exercise (DRT) might be the most promising agent for fighting sarcopenia in older people. However, the positive effect of DRT on osteopenia/osteoporosis in men has still to be confirmed. To evaluate the effect of low-volume/high-intensity (HIT)-DRT on bone mineral density (BMD) and skeletal muscle mass index (SMI) in men with osteosarcopenia, we initiated the Franconian Osteopenia and Sarcopenia Trial (FrOST). Forty-three sedentary community-dwelling older men (aged 73 to 91 years) with osteopenia/osteoporosis and SMI-based sarcopenia were randomly assigned to a HIT-RT exercise group (EG; n = 21) or a control group (CG; n = 22). HIT-RT provided a progressive, periodized single-set DRT on machines with high intensity, effort, and velocity twice a week, while CG maintained their lifestyle. Both groups were adequately supplemented with whey protein, vitamin D, and calcium. Primary study endpoint was integral lumbar spine (LS) BMD as determined by quantitative computed tomography. Core secondary study endpoint was SMI as determined by dual-energy X-ray absorptiometry. Additional study endpoints were BMD at the total hip and maximum isokinetic hip-/leg-extensor strength (leg press). After 12 months of exercise, LS-BMD was maintained in the EG and decreased significantly in the CG, resulting in significant between-group differences (p < 0.001; standardized mean difference [SMD] = 0.90). In parallel, SMI increased significantly in the EG and decreased significantly in the CG (p < 0.001; SMD = 1.95). Total hip BMD changes did not differ significantly between the groups (p = 0.064; SMD = 0.65), whereas changes in maximum hip-/leg-extensor strength were much more prominent (p < 0.001; SMD = 1.92) in the EG. Considering dropout (n = 2), attendance rate (95%), and unintended side effects/injuries (n = 0), we believe our HIT-RT protocol to be feasible, attractive, and safe. In summary, we conclude that our combined low-threshold HIT-RT/protein/vitamin D/calcium intervention was feasible, safe, and effective for tackling sarcopenia and osteopenia/osteoporosis in older men with osteosarcopenia. © 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.

Effects of High-Intensity Resistance Training on Fitness and Fatness in Older Men With Osteosarcopenia

To date, there has been no study on the long-term effects of resistance exercise on sarcopenia and obesity indices for people with sarcopenia. The present study thus aimed to determine the effect of 18 months of periodized, high-velocity/intensity/effort progressive resistance training (HIT-RT) on body composition and strength in older men with osteosarcopenia. Using a single-blind, two-group parallel design, 43 community-dwelling men, 72 years and older, with osteopenia and sarcopenia in Erlangen-Nürnberg, Germany, were randomly assigned to two study arms by drawing lots: (1) an exercise group that conducted a consistently supervised periodized high-velocity/intensity/effort protocol (HIT-RT; n = 21) on machines twice a week for 18 months or (2) a control group (CG; n = 22) that maintained their physical activity/exercise habits. Both groups were supplied with protein, cholecalciferol, and calcium according to current recommendations. The study outcomes were lean body mass (LBM), total and abdominal body fat as determined by dual-energy X-ray absorptiometry and maximum hip/leg extensor strength as assessed on an isokinetic leg press at baseline and after 8, 12, and 18 months of follow-up. The intention-to-treat principle and multiple imputation were applied to calculated study outcomes. After 18 months of HIT-RT, altogether five participants were lost to follow up (HIT-RT: n = 2, CG: n = 3). The attendance rates (95%) for HIT-RT were high; relevant adverse effects were not observed. Significant effects (i.e., differences between HIT-RT vs. CG) in favor of HIT-RT were determined for LBM (+1.73 kg, 95% CI: +1.13 to +2.32 kg), total body fat mass (-2.44 kg, 95% CI: -1.28 to 3.60 kg), abdominal body fat percentage (-2.68, 95% CI: -1.70 to -3.66), and maximum hip/leg extensor strength (+533 N, 95% CI: +397 to +670 N; all p < 0.001). Even after adjusting for multiple testing, all effects remained significant. Of note, after 8 months of HIT-RT, only slight (LBM and fat indices) to moderate (maximum strength) ongoing effects were observed. Carefully introduced, continuously supervised HIT-RT is an effective, attractive, feasible, and safe method to improve body composition and muscle strength in older community-dwelling men with sarcopenia. However, even when consequently applying principles of exercise intensity progression within the RT protocol, only slight further positive changes were observed after 8 months of exercise.

Effects of High Intensity Dynamic Resistance Exercise and Whey Protein Supplements on Osteosarcopenia in Older Men with Low Bone and Muscle Mass. Final Results of the Randomized Controlled FrOST Study

The present study aimed to evaluate the effect of high intensity dynamic resistance exercise (HIT-DRT) and whey protein supplementation (WPS) on bone mineral density (BMD) and sarcopenia parameters in osteosarcopenic men. Men ≥ 72 years with osteosarcopenia (n = 43) were randomly assigned to a HIT-RT (HIT-RT: n = 21) or a non-training control group (n = 22). Supervised HIT-RT twice/week was applied for 18 months, while the control group maintained their habitual lifestyle. Supplying WPS, total protein intake amounted to 1.5-1.6 (HIT-RT) and 1.2 g/kg/body mass/d (control). Both groups were supplied with calcium and vitamin D. Primary study outcomes were BMD and the sarcopenia Z-score. After adjusting for multiplicity, we observed significant positive effects for sarcopenia Z-score (standardized mean difference (SMD): 1.40), BMD at lumbar spine (SMD: 0.72) and total hip (SMD: 0.72). In detail, effect sizes for skeletal muscle mass changes were very pronounced (1.97, p < 0.001), while effects for functional sarcopenia parameters were moderate (0.87, p = 0.008; handgrip strength) or low (0.39, p = 0.209; gait velocity). Apart from one man who reported short periods of temporary worsening of existing joint pain, no HIT-RT/WPS-related adverse effects or injuries were reported. We consider HIT-RT supported by whey protein supplementation as a feasible, attractive, safe and highly effective option to fight osteosarcopenia in older men.

Renoprotective effect of Capsicum annum against ethanol-induced oxidative stress and renal apoptosis

The present study explored the ameliorative potency of aqueous extract of Capsicum annum (AqCA), against oxidative imbalance and renal toxicity induced by ethanol. Randomly grouped male Wistar rats (n = 6), were marked as ethanol-treated (2 g/kg bw, i.p.), CA₁₂₅ (125 mg/kg bw, i.p.), CA₂₅₀ (250 mg/kg bw, i.p.), ethanol pre-treated with CA (similar doses), and control (0.5 ml normal saline, i.p.), and treated for 30 consecutive days. Biochemical analysis of tissue and serum parameters was performed, along with histopathological and histochemical studies. Also, we performed TUNEL assay and western blotting for our experimental groups. Statistical analysis revealed significant (p ≤ .001) alteration in the levels of antioxidant enzymes, serum urea, creatinine, pro-inflammatory cytokines, and cleaved caspases, along with histopathological alterations in the ethanol-treated group. Prior treatment with AqCA prevented ethanol-induced alterations in tissue and serum parameters. These findings indicate that the extract of CA can protect renal cells from ethanol-induced damage by inhibiting oxidative stress, inflammatory response, and apoptosis. PRACTICAL APPLICATIONS: Chronic alcohol consumption is a major public health concern that leads to various diseases and social problems as well. It affects both the affluent and non-affluent society equally. Alcohol (ethanol) is a renowned hepato-toxicant and a well-documented risk factor for oxidative stress, with less known effect on the kidney. Thus, it is essential to investigate the effect of alcohol metabolism on the kidney to find a remedy to prevent it. The present investigation depicts the anti-oxidative and anti-inflammatory role of Capsicum annum against ethanol-induced renal damage. The outcome of this study can be utilized in the future for phytotherapeutic herbal drug formulation. Besides, the bioactive components identified in the study can be further explored by researchers or pharmaceutical corporates for potential therapeutic purpose against renal impairment.

Experimental Models of Sarcopenia: Bridging Molecular Mechanism and Therapeutic Strategy

Sarcopenia has been defined as a progressive decline of skeletal muscle mass, strength, and functions in elderly people. It is accompanied by physical frailty, functional disability, falls, hospitalization, and mortality, and is becoming a major geriatric disorder owing to the increasing life expectancy and growing older population worldwide. Experimental models are critical to understand the pathophysiology of sarcopenia and develop therapeutic strategies. Although its etiologies remain to be further elucidated, several mechanisms of sarcopenia have been identified, including cellular senescence, proteostasis imbalance, oxidative stress, and "inflammaging." In this article, we address three main aspects. First, we describe the fundamental aging mechanisms. Next, we discuss both in vitro and in vivo experimental models based on molecular mechanisms that have the potential to elucidate the biochemical processes integral to sarcopenia. The use of appropriate models to reflect sarcopenia and/or its underlying pathways will enable researchers to understand sarcopenia and develop novel therapeutic strategies for sarcopenia. Lastly, we discuss the possible molecular targets and the current status of drug candidates for sarcopenia treatment. In conclusion, the development of experimental models for sarcopenia is essential to discover molecular targets that are valuable as biochemical biomarkers and/or therapeutic targets for sarcopenia.

Effects of the Combination of β-Hydroxy-β-Methyl Butyrate and R(+) Lipoic Acid in a Cellular Model of Sarcopenia

: Sarcopenia is a clinical problem associated with several pathological and non-pathological conditions. The aim of the present research is the evaluation of the pharmacological profile of the leucine metabolite β-hydroxy-β-methyl butyrate (HMB) associated with the natural R(+) stereoisomer of lipoic acid (R(+)LA) in a cellular model of muscle wasting. The C2C12 cell line is used as myoblasts or is differentiated in myotubes, sarcopenia is induced by dexamethasone (DEX). A Bonferroni significant difference procedure is used for a post hoc comparison. DEX toxicity (0.01-300 µM concentration range) is evaluated in myoblasts to measure cell viability and caspase 3 activation after 24 h and 48 h; cell incubation with 1 µM DEX for 48 h is chosen as optimal treatment for decreasing cell viability and increasing caspase 3 activity. R(+)LA or HMB significantly prevents DEX-induced cell mortality; the efficacy is improved when 100 µM R(+)LA is combined with 1 mM HMB. Regarding myoblasts, this combination significantly reduces DEX-evoked O2- production and protein oxidative damage. During the early phase of myotube formation, the mixture preserves the number of myogenin-positive cells, whereas it completely prevents the DEX-dependent damage in a later phase of myotube differentiation (7 days), as evaluated by cell diameter and percentage of multinucleated cells. R(+)LA in association with HMB is suggested for sarcopenia therapy.

Biomarkers of sarcopenia in very old patients with hip fracture

BACKGROUND

Hip fracture is both a cause and a consequence of sarcopenia. Older persons with sarcopenia have an increased risk of falling, and the prevalence of sarcopenia may be increased in those who suffer a hip fracture. The aim of this study was to explore potential biomarkers (neuromuscular and peripheral pro-inflammatory and oxidative stress markers) that may be associated with sarcopenia in very old persons with hip fracture.

METHODS

We recruited 150 consecutive patients ≥80 years old admitted to an orthogeriatric unit for an osteoporotic hip fracture. Muscle mass was assessed pre-operatively using bioelectrical impedance analysis; Janssen's (J) and Masanés' (M) reference cut-off points were used to define low muscle mass. Muscle strength was assessed with handgrip strength (Jamar's dynamometer). Sarcopenia was defined by having both low muscle mass and strength and using the European Working Group on Sarcopenia in Older People 2 definition of probable sarcopenia (low grip strength). Peripheral markers-pro-inflammatory and oxidative stress parameters-were determined either in the plasma or in the erythrocyte fraction obtained from peripheral whole blood of every patient pre-operatively.

RESULTS

Mean age was 87.6 ± 4.9 years, and 78.7% were women. The prevalence of sarcopenia was 11.5% with Janssen's, 34.9% with Masanés' cut-offs, and 93.3% with the European Working Group on Sarcopenia in Older People 2 definition of probable sarcopenia. Among the four pro-inflammatory cytokines tested in plasma, only tumour necrosis factor-α was different (lower) in sarcopenic than in non-sarcopenic participants using both muscle mass cut-offs (J 7.9 ± 6.2 vs. 8.3 ± 5.8, M 6.8 ± 4.7 vs. 9.1 ± 6.2). Erythrocyte glutathione system showed a non-significant tendency to lower glutathione levels and glutathione/oxidized glutathione ratios in sarcopenic participants compared with non-sarcopenic subjects. Catalase activity was also lower in sarcopenic participants (J 2904 ± 1429 vs. 3329 ± 1483, M 3037 ± 1430 vs. 3431 ± 1498). No significant differences were found between groups in chymotrypsin-like activity of the 20S proteasome, superoxide dismutase, glutathione peroxidase and butyrylcholinesterase activity, C-terminal agrin fragment, interferon-γ, or interleukin-1β.

CONCLUSIONS

The prevalence of sarcopenia in patients with hip fracture varies according to the definition and the muscle mass reference cut-off points used. We did not find differences in most neuromuscular, pro-inflammatory, or oxidative stress markers, except for lower peripheral tumour necrosis factor-α levels and catalase activity in sarcopenic participants, which may be markers of an early inflammatory reaction that is hampered in sarcopenic patients.

Bacopa Monnieri Protects the Directly Affected Organ as Well as Distant Organs Against I/R Injury by Modulating Anti-Inflammatory and Anti-Nitrosative Pathways in A Rat Model for Infra-Renal Aortic Occlusion

OBJECTIVE

To investigate the protective effect and underlying mechanisms of B. monnieri, a medicinal plant, on kidney and skeletal muscle injury induced by infra-renal abdominal aorta clamping for 2-hours (ischemia) and following removal of the clamp (reperfusion, 2-hours).

METHODS

Rats were divided into four groups (n = 6): (I) animals given only saline (sham-control); (II) animals given B. monnieri extract for 10-days (300 mg/kg/day) (Bacopa-treated sham); (III) animals subjected to ischemia/reperfusion (I/R); (IV) animals given B. monnieri extract and then subjected to I/R. Kidneys and lower extremity muscles were examined for GPx, CAT, iNOS, 3-NT, IL-1β and TNF-α. Apoptosis and injury were evaluated by TUNEL and H&E staining, respectively.

RESULTS

I/R resulted in TUNEL positive cells, periarterial edema and glomerular capillary dilatation, decreased GPx activity, unchanged CAT, iNOS, 3-NT, IL-1β and TNF-α in kidney. B. monnieri minimized renal remote reperfusion injury, and Group IV showed a lower degree of renal histopathology score when compared to the others. B. monnieri mitigated muscle I/R injury, decreased muscle hypertrophy, myofibril abnormalities and apoptosis. Muscle 3-NT and cytokine levels were increased by I/R, and B. monnieri inhibited iNOS and 3-NT both in sham-control and I/R groups. Muscle GPx unaffected by I/R or B. monnieri, but CAT was inhibited only in B. monnieri-treated I/R group. Muscle iNOS, 3-NT, IL-1β, TNF-α levels and CAT activity of B. monnieri-treated I/R rats were lower than those in sham-control or Bacopa-treated sham.

CONCLUSIONS

B. monnieri can protect the directly affected organ as well as distant organs against I/R injury by modulating anti-inflammatory and anti-nitrosative pathways.

High Intensity Resistance Exercise Training to Improve Body Composition and Strength in Older Men With Osteosarcopenia. Results of the Randomized Controlled Franconian Osteopenia and Sarcopenia Trial (FrOST)

Considerably decreased muscle mass and function are subsumed under "sarcopenia," a geriatric syndrome. Dedicated exercise programs maintain muscle mass and function; however, due to the limited enthusiasm of older adults to exercise, it is important to generate low-threshold interventions for this vulnerable cohort. Thus, the primary aim of this study was to determine the effect of low volume/high intensity resistance exercise training (HIT-RT) combined with protein supplementation on body composition and strength in older men with sarcopenia and osteopenia (osteosarcopenia). Forty-three community-dwelling (cdw) older men (78 ± 4 years) with osteosarcopenia were randomly allocated to a consistently supervised HIT-RT (n = 21) or an inactive control group (CG, n = 22). HIT-RT scheduled a single set protocol with high intensity and effort applied twice a week for 36 weeks so far. Both groups were supplemented with Vit-D (800 IE/d), calcium (1,000 mg/d) and whey-protein (CG: 1.2 vs. HIT-RT: 1.5-1.7 g/kg/d). Study endpoints were body composition (dual-energy x-ray absorptiometry) and maximum isokinetic hip/leg-extensor strength (MIES) by leg-press. After 36 weeks, one participant who developed prostate cancer after inclusion in the study (HIT-RT) and two participants who lost interest (CG, HIT-RT) quit the study. Attendance rate for HIT-RT averaged 93 ± 5%. Total and thigh lean body mass (LBM) significantly (p < 0.001) increased in the HIT-RT and was maintained in the CG (p = 0.46 and 0.37). Differences between the groups for changes of total and thigh LBM were pronounced (p < 0.001; SMD d' = 1.17 and 1.20). Total and abdominal body fat percentage decreased significantly in the HIT-RT (p < 0.001) and increased in the CG (p = 0.039 and p = 0.097). Intergroup differences were significant (p < 0.001; SMD: d' = 1.35 and 1.28). Finally, MIES was maintained in the CG (p = 0.860), and improved significantly (p < 0.001) in the HIT-RT. Differences between the groups were significant (p < 0.001, SMD: d' = 2.41). No adverse effects of the intervention were observed. In summary, the HIT-RT/protein protocol significantly affected body composition and strength in cdw men 72 years+ with osteosarcopenia. In the absence of negative side effects, the intervention was feasible, attractive and time effective. Thus, we conclude that supervised HIT-RT might be an exercise option for older men.

Detection of HNE Modification of Proteins in Aging Mouse Tissues: A Western Blot-Based Approach

4-Hydroxenonenal (HNE) is one of the major α,β-unsaturated aldehyde products of lipid peroxidation. HNE can form conjugates with macromolecules, including protein, and thereby alter their function. HNE and its conjugation with proteins are increased in aging and age-related diseases. To elucidate how HNE is involved in these aging-related pathophysiological changes, it is necessary to assess HNE modification of proteins. Here a simple and convenient Western-blot based method is presented to detect HNE modification of proteins in tissues of aging mice.

The Emerging Roles of Nicotinamide Adenine Dinucleotide Phosphate Oxidase 2 in Skeletal Muscle Redox Signaling and Metabolism

Significance: Skeletal muscle is a crucial tissue to whole-body locomotion and metabolic health. Reactive oxygen species (ROS) have emerged as intracellular messengers participating in both physiological and pathological adaptations in skeletal muscle. A complex interplay between ROS-producing enzymes and antioxidant networks exists in different subcellular compartments of mature skeletal muscle. Recent evidence suggests that nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (NOXs) are a major source of contraction- and insulin-stimulated oxidants production, but they may paradoxically also contribute to muscle insulin resistance and atrophy. Recent Advances: Pharmacological and molecular biological tools, including redox-sensitive probes and transgenic mouse models, have generated novel insights into compartmentalized redox signaling and suggested that NOX2 contributes to redox control of skeletal muscle metabolism. Critical Issues: Major outstanding questions in skeletal muscle include where NOX2 activation occurs under different conditions in health and disease, how NOX2 activation is regulated, how superoxide/hydrogen peroxide generated by NOX2 reaches the cytosol, what the signaling mediators are downstream of NOX2, and the role of NOX2 for different physiological and pathophysiological processes. Future Directions: Future research should utilize and expand the current redox-signaling toolbox to clarify the NOX2-dependent mechanisms in skeletal muscle and determine whether the proposed functions of NOX2 in cells and animal models are conserved into humans.