Combined aerobic exercise and enzyme replacement therapy rejuvenates the mitochondrial-lysosomal axis and alleviates autophagic blockage in Pompe disease.

A unifying feature in the pathogenesis of aging, neurodegenerative disease, and lysosomal storage disorders is the progressive deposition of macromolecular debris impervious to enzyme catalysis by cellular waste disposal mechanisms (e.g., lipofuscin). Aerobic exercise training (AET) has pleiotropic effects and stimulates mitochondrial biogenesis, antioxidant defense systems, and autophagic flux in multiple organs and tissues. Our aim was to explore the therapeutic potential of AET as an ancillary therapy to mitigate autophagic buildup and oxidative damage and rejuvenate the mitochondrial-lysosomal axis in Pompe disease (GSD II/PD). Fourteen weeks of combined recombinant acid α-glucosidase (rhGAA) and AET polytherapy attenuated mitochondrial swelling, fortified antioxidant defense systems, reduced oxidative damage, and augmented glycogen clearance and removal of autophagic debris/lipofuscin in fast-twitch skeletal muscle of GAA-KO mice. Ancillary AET potently augmented the pool of PI4KA transcripts and exerted a mild restorative effect on Syt VII and VAMP-5/myobrevin, collectively suggesting improved endosomal transport and Ca(2+)- mediated lysosomal exocytosis. Compared with traditional rhGAA monotherapy, AET and rhGAA polytherapy effectively mitigated buildup of protein carbonyls, autophagic debris/lipofuscin, and P62/SQSTM1, while enhancing MnSOD expression, nuclear translocation of Nrf-2, muscle mass, and motor function in GAA-KO mice. Combined AET and rhGAA therapy reactivates cellular clearance pathways, mitigates mitochondrial senescence, and strengthens antioxidant defense systems in GSD II/PD. Aerobic exercise training (or pharmacologic targeting of contractile-activity-induced pathways) may have therapeutic potential for mitochondrial-lysosomal axis rejuvenation in lysosomal storage disorders and related conditions (e.g., aging and neurodegenerative disease).

Prolonged swimming promotes cellular oxidative stress and p66Shc phosphorylation, but does not induce oxidative stress in mitochondria in the rat heart.

Exercise-induced changes in p66Shc-dependent signaling pathway are still not fully understood. The p66Shc protein is one of the key players in cell signaling, particularly in response to oxidative stress. Therefore, the aim of this study was to investigate the effect of prolonged swimming on the phosphorylation of p66Shc as well as the induction of mitochondrial and cellular oxidative stress in rat hearts. Male Wistar rats were divided into a sedentary control group and an exercise group. The exercised rats swam for 3 hours and were burdened with an additional 3% of their body weight. After the cessation of exercise, their hearts were removed immediately for experiments. The exercise protocol caused increased levels of the following oxidative stress parameters in cardiac cells: DNA damage, protein carbonyls, and lipid dienes. There was also increased phosphorylation of p66Shc without any alterations in Akt and extracellular signal-regulated kinases. Changes in the ferritin L levels and the L to H subunit ratio were also observed in the exercised hearts compared with the control hearts. Despite increased phosphorylation of p66Shc, no significant increase was observed in either mitochondrial H2O2 release or mitochondrial oxidative stress markers. Regardless of the changes in phosphorylation of p66Shc, the antioxidant enzyme activities (superoxide dismutase and catalase) and anti-apoptotic (Bcl2), and pro-apoptotic (Bax) protein levels were not affected by prolonged swimming. Further studies are required to investigate whether p66Shc phosphorylation is beneficial or detrimental to cardiac cells after exercise cessation.

Changes in skeletal muscle iron metabolism outpace amyotrophic lateral sclerosis onset in transgenic rats bearing the G93A hmSOD1 gene mutation.

OBJECTIVE: Recently, iron and the adaptor protein "p66Shc" have been shown to play an important role in the development of amyotrophic lateral sclerosis (ALS) in rats. We hypothesized that changes in muscle p66Shc activity and iron metabolism would appear before visible symptoms of the disease occurred. METHODS: In the present study, we used transgenic rats bearing the G93A hmSOD1 gene mutation and their non-transgenic littermates to test this hypothesis. We examined muscle p66Shc phosphorylation and iron metabolism in relation to oxidative stress in animals at three disease stages: asymptomatic (ALS I), disease onset (ALS II), and end-stage disease (ALS III). RESULTS: Significant changes in iron metabolism and markers of lipid and protein oxidation were detected in ALS I animals, which manifested as decreased levels of ferritin H and ferroportin 1 (Fpn1) and increased levels of ferritin L levels. Muscles of ALS I rats possessed increased levels of p66Shc phosphorylated at Ser(36) compared with muscles of control rats. During disease progression, level of ferritin H significantly increased and was accompanied by iron accumulation. CONCLUSIONS: This study showed that multiple mechanisms may underlie iron accumulation in muscles of ALS transgenic rats, which include changes in blood hepcidin and muscle Fpn1 and increased level of muscle ferritin H. These data suggest that impaired iron metabolism is not a result of changes in motor activity.

Running a 100-km ultra-marathon induces an inflammatory response but does not raise the level of the plasma iron-regulatory protein hepcidin.

AIM: Exercise may induce an inflammatory response that may lead to changes in iron metabolism. The aim of this study was to examine the relationship between the inflammation induced by a 100 km run and the level of hepcidin, which is a hormone regulating iron metabolism. METHODS: Six males, age 44.5±13.5 years, running 100 km. SETTING: the CRP protein, IL-6 and leucocyte count were measured as an index of inflammation. RESULTS: A 100 km run caused a progressive increase in blood IL-6 concentration, which reached the highest values after 75 km. Furthermore, an increase in levels of CRP, a marker of inflammation, was observed after the 100 km run and continued to increase after a 14 h recovery period. Leucocyte number and markers of muscle damage were significantly elevated after the 100 km run. This was accompanied by a decrease in transferrin saturation and an increase in blood haemoglobin and ferritin. Despite all these changes, the 100 km race did not affect blood hepcidin concentration either during the run or after a 14 h recovery period. CONCLUSION: The study shows that a 100 km run induces an inflammatory response but does not trigger changes in the blood hepcidin level. Thus it can be concluded that changes in IL-6 are not sufficient to increase the blood hepcidin level in runners.

Sensitivity of natural killer cells to activation in the process of ageing is related to the oxidative and inflammatory status of the elderly.

The role of the innate immunity during human ageing is not well understood. The aim of the study was to estimate reactivity of NK (natural killer) cells in the very old (mean age 91 years) and old subjects (mean age 78 years) compared to young individuals (mean age 26 years) in respect to the indices of the oxidative stress (telomere length of NK cells, serum content of -H groups), serum total antioxidant status and serum concentrations of interleukin 6 and tumor necrosis factor-α (TNF-α). The activation state of NK cells, reflected by telomerase activity and intracellular interferon γ (IFNγ) content, was also measured. We found that length of telomeres in NK cells and serum concentration of -SH groups decreased both in the old and the oldest subjects as compared to young individuals. The oldest seniors, on the contrary to the old ones, revealed similar level of serum antioxidant status as the young subjects. The serum level of IL-6, not detectable in the young subjects, did not differ in the oldest and old seniors. TNF-α serum concentrations progressively increased with age. After stimulation, NK cells of both old groups showed higher intracellular levels of IFNγ than young subjects. IL-2-activated NK cells of the oldest seniors showed the highest increase of telomerase activity as compared to the other age groups. Serum level of IL-6 correlated positively with activation markers of NK cells. Moreover, in seniors but not in young subjects, the number of active, IFNγ-expressing NK cells, correlated positively with the serum content of the -SH groups. These findings indicate that sensitivity of NK cells to activation is maintained during ageing and this phenomenon may be related to the oxidative and inflammatory status of the elderly.

Does the septic shock interfere experimental acute pancreatitis in rats?

INTRODUCTION: Acute pancreatitis is a disease involving pro-inflammatory mediators. Two complex and multifactorial pathogenetic ways lead to edematous or necrotizing pancreatitis. The course of the disease is thought to be the consequence of an acute inflammatory response. AIM: The authors examined the impact of Escherichia coli LPS on the acute cerulein pancreatitis in rats. METHODS: The study was performed on rats using the ceruleine pancreatitis model. The activation status of polymorphonuclear cells, blood IL-6 concentration, oxidative stress parameters, pancreatic enzymes concentration and microscopic alterations were determined at 5th and 9th h observations. RESULTS: In acute pancreatitis and acute pancreatitis with LPS groups, the peripheral polymorphonuclear cells activity was lower than in control one. Authors noticed the same neutrophil activation in acute pancreatitis after lipopolysaccharide administration although the peripheral blood polymorphonuclear cells count was significantly higher at the 9th h observation. LPS neither changed the oxidative stress within pancreatic gland, nor amylase or serum lipase activity. LPS given to acute pancreatitis animals resulted in significant increase of serum IL-6 concentration at 5th observation turning normal after 9th h. CONCLUSIONS: Collected data supports thesis of early polymorphonuclear cells involvement in acute pancreatitis and oxidative stress evidence in pancreatic parenchyma. However, results did not reveal that administration of LPS amplified inflammatory response during the course of acute pancreatitis.

Content and redistribution of vitamin E in tissues of Wistar rats under oxidative stress induced by hydrazine.

Hydrazine toxicity is associated with generation of several kinds of free radicals and oxidative stress in cell. Experiments in vivo have demonstrated that oxidative stress could either diminish or increase concentration of vitamin E in some tissues. Thus in the present study we performed experiments to determine whether hydrazine-induced oxidative stress would change the tissue levels of the vitamin. Seven days of hydrazine intoxication led to accumulation of different amounts of vitamin E: 215% in the liver, 118% in the heart, 135% in the spleen, and 100% in the muscle over control value. There were no changes in the level of the vitamin in kidney and pancreas, despite its significant depletion in the serum. In tissue that accumulated vitamin E after hydrazine treatment, an increased of oxidative stress measured by the concentration of lipid-soluble fluorophore was observed. Significant increases of 107%, 46%, 72%, and 58% over control values were observed in the liver, heart, spleen, and muscle, respectively. Rats treated with hydrazine and pharmacological doses of alpha-tocopherol accumulated higher concentrations of vitamin E in all studied tissues compared with the alpha-tocopherol-only treated rats. However, in tissues with elevated levels of fluorophore as liver, heart, spleen, and muscle, the accumulation of vitamin E was 5.03, 4.5, 4.03, and 4.6 times higher than in alpha-tocopherol-treated rats, respectively. Vitamin E concentration was much higher than in kidney and pancreas, where the accumulation was only 2.31 and 2.6 times higher. On the other hand, 3 days of hydrazine treatment did not change either the level of lipid-soluble fluorophore or the level of vitamin E in the liver mitochondria, microsomes, and homogenate. In skeletal muscle vitamin E caused decreased lipofuscin accumulation, and in pancreas vitamin E increased lipofuscin accumulation. Our data indicate that hydrazine is able to modify significantly vitamin E status in different rat tissues.