Aerobic exercise training-induced alteration of gut microbiota composition affects endurance capacity.

This study aimed to clarify whether aerobic exercise training-induced alterations in the gut microbiota affect physiological adaptation with endurance exercise capacity. In study 1, ICR mice were randomly divided into three groups: vehicle intake + sedentary (V+S), vehicle intake + exercise training (V+Ex) and antibiotic intake + exercise training (AB+Ex). In the exercise training groups, treadmill running was performed for 8 weeks. During the exercise training intervention, the antibiotic-intake group freely drank water containing antibiotics. In study 2, ICR mice were randomly divided into three groups: Sham, transplantation of caecum microbiota from sedentary mice (Sed-CMT) and exercise training mice (Ex-CMT). In study 1, the treadmill running time to exhaustion, an index of maximal aerobic capacity, after aerobic exercise training in the V+Ex group was significantly longer than that in the V+S and AB+Ex groups. Gastrocnemius muscle citrate synthase (CS) activity and PGC-1α protein levels in the V+Ex group were significantly higher than in the V+S and AB+Ex groups. The bacterial Erysipelotrichaceae and Alcaligenaceae families were positively correlated with treadmill running time to exhaustion. In study 2, the treadmill running time to exhaustion after transplantation was significantly higher in the Ex-CMT group than in the Sham and Sed-CMT groups. Furthermore, CS activity and PGC-1α protein levels in the gastrocnemius muscle were significantly higher in the Ex-CMT group than in the Sham and Sed-CMT groups. Thus, gut microbiota altered by aerobic exercise training may be involved in the augmentation of endurance capacity and muscle mitochondrial energy metabolism. KEY POINTS: Aerobic exercise training changes gut microbiota composition, and the Erysipelotrichaceae and Alcaligenaceae families were among the altered gut bacteria. The gut microbiota was associated with endurance performance and metabolic regulator levels in skeletal muscle after aerobic exercise training. Continuous antibiotic treatment attenuated the increase in endurance performance, citrate synthase activity and PGC-1α levels in skeletal muscle induced by aerobic exercise training. Gut microbiota transplantation from exercise-trained mice improved endurance performance and metabolic regulator levels in recipient skeletal muscle, despite the absence of aerobic exercise training.

Icing after skeletal muscle injury with necrosis in a small fraction of myofibers limits inducible nitric oxide synthase-expressing macrophage invasion and facilitates muscle regeneration.

Growing evidence from animal experiments suggests that icing after skeletal muscle injury is harmful to muscle regeneration. However, these previous experimental models yielded massive necrotic myofibers, whereas muscle injury with necrosis in a small myofiber fraction (<10%) frequently occurs in human sports activities. Although macrophages play a proreparative role during muscle regeneration, they exert a cytotoxic effect on muscle cells through an inducible nitric oxide synthase (iNOS)-mediated mechanism. In this study, we established an animal injury model with necrosis limited to a small myofiber fraction and investigated the effect of icing on muscle regeneration with a focus on macrophage-related events. Icing after muscle injury of this model resulted in an enlarged size of regenerating myofibers compared with those in untreated animals. During the regenerative process, icing attenuated the accumulation of iNOS-expressing macrophages, suppressed iNOS expression in the whole damaged muscle, and limited the expansion of the injured myofiber area. In addition, icing increased the ratio of M2 macrophages within the injured site at an earlier time point than that in untreated animals. Following these phenomena in icing-treated muscle regeneration, an early accumulation of activated satellite cells within the damaged/regenerating area occurred. The expression level of myogenic regulatory factors, such as MyoD and myogenin, was not affected by icing. Taken together, our results suggest that icing after muscle injury with necrosis limited to a small fraction of myofibers facilitates muscle regeneration by attenuating iNOS-expressing macrophage invasion, limiting muscle damage expansion, and accelerating the accumulation of myogenic cells which form regenerating myofibers.

Antidepressant properties of voluntary exercise mediated by gut microbiota.

Although regular exercise has been reported to prevent depression, it has not been clarified whether the gut microbiota is involved in the factors that prevent depression through exercise. We investigated the effects of voluntary exercise on the gut microbiota and the prevention of depression-like behaviors using mice. C57BL/6 J male mice were subjected to 10 weeks of sedentary control or wheel running, then they were subjected to social defeat stress (SDS). Exercise attenuated that sucrose drinking was decreased by SDS treatment. Exercise increased the expression of Bdnf and decreased expression of Zo-1 and Claudin5 in the brain. Fecal Turicibacter, Allobaculum, and Clostridium sensu stricto, and propionate in the cecum were decreased by the exercise. Voluntary exercise-induced antidepressant properties might be partially caused by suppression of serotonin uptake into gut microbiota and increase the permeability of the blood-brain barrier via reduced propionate production.

Gain-of-function mutations in ALPK1 cause an NF-κB-mediated autoinflammatory disease: functional assessment, clinical phenotyping and disease course of patients with ROSAH syndrome.

OBJECTIVES: To test the hypothesis that ROSAH (retinal dystrophy, optic nerve oedema, splenomegaly, anhidrosis and headache) syndrome, caused by dominant mutation in ALPK1, is an autoinflammatory disease. METHODS: This cohort study systematically evaluated 27 patients with ROSAH syndrome for inflammatory features and investigated the effect of ALPK1 mutations on immune signalling. Clinical, immunologic and radiographical examinations were performed, and 10 patients were empirically initiated on anticytokine therapy and monitored. Exome sequencing was used to identify a new pathogenic variant. Cytokine profiling, transcriptomics, immunoblotting and knock-in mice were used to assess the impact of ALPK1 mutations on protein function and immune signalling. RESULTS: The majority of the cohort carried the p.Thr237Met mutation but we also identified a new ROSAH-associated mutation, p.Tyr254Cys.Nearly all patients exhibited at least one feature consistent with inflammation including recurrent fever, headaches with meningeal enhancement and premature basal ganglia/brainstem mineralisation on MRI, deforming arthritis and AA amyloidosis. However, there was significant phenotypic variation, even within families and some adults lacked functional visual deficits. While anti-TNF and anti-IL-1 therapies suppressed systemic inflammation and improved quality of life, anti-IL-6 (tocilizumab) was the only anticytokine therapy that improved intraocular inflammation (two of two patients).Patients' primary samples and in vitro assays with mutated ALPK1 constructs showed immune activation with increased NF-κB signalling, STAT1 phosphorylation and interferon gene expression signature. Knock-in mice with the Alpk1 T237M mutation exhibited subclinical inflammation.Clinical features not conventionally attributed to inflammation were also common in the cohort and included short dental roots, enamel defects and decreased salivary flow. CONCLUSION: ROSAH syndrome is an autoinflammatory disease caused by gain-of-function mutations in ALPK1 and some features of disease are amenable to immunomodulatory therapy.

Acetyl-L-carnitine attenuates Poly I:C-induced sickness behavior in mice.

Fatigue is accompanied by a decrease in physical activity or malaise, and might be reduced by acetyl-L-carnitine (ALC) administration. The purpose of this study was to investigate the preventive effects of ALC on Poly I:C-induced sickness behavior in mice. For the experiment, male C3H/HeN mice were used and treated with ALC for 5 days before Poly I:C administration. ALC administration attenuated the decrease in wheel behavior activity of mice at 24 h after Poly I:C administration and ALC-treated mice quickly recovered from the sickness behavior. The gene expression of brain-derived neurotrophic factor (BDNF) in the cerebrum and hippocampus, which is associated with physical activity, was higher in the ALC-treated group. Translocator protein 18kDa (TSPO), which has cytoprotective effects, was up-regulated in the cerebrum and hippocampus, suggesting that ALC suppressed the decrease in activity induced by Poly I:C treatment through enhancement of cytoprotective effects in the brain.

A simple questionnaire for the detection of testosterone deficiency in men with late-onset hypogonadism.

The Aging Males' Symptoms (AMS) score, developed to screen for late-onset hypogonadism (LOH), contains 17 questions regarding mental, physical, and sexual parameters. In the Japanese guidelines, a free testosterone (FT) <8.5 pg/mL is recommended for testosterone treatment. However, previous studies have shown no correlation between total AMS scores and testosterone concentration. We aimed to develop a better questionnaire for the detection of testosterone deficiency in men, for the diagnosis of LOH. In 234 Japanese men, aged 40-64 years, we analyzed the relationships of AMS with serum total testosterone (TT), FT, calculated FT (cFT), and calculated bioavailable testosterone (cBT), and identified useful questions for the detection of testosterone deficiency. Four scores, a decrease in muscular strength, a decrease in ability to perform sexually or the frequency, a decrease in the number of morning erections, and a decrease in sexual desire/libido, were negatively associated with two or more of the above four testosterone parameters, and the sum of these four scores (named the selective score) correlated with TT and cFT, independent of age. Statistical analysis revealed an association between insulin resistance and testosterone deficiency, and a higher selective score in smokers than non-smokers. Cubic function model analysis and logistic regression analysis revealed that selective scores ≥10 corresponded with the testosterone concentrations recommended for the diagnosis of LOH, including FT <8.5 pg/mL, independent of age, insulin resistance, and smoking. Thus, the selective score represents a simple and useful means for screening of testosterone deficiency in Japanese men, as an indicator of LOH.

Effect of dietary cellulose nanofiber and exercise on obesity and gut microbiota in mice fed a high-fat-diet.

Cellulose nanofiber (CN) consumption with exercise could be a potential strategy to control obesity. Here, we studied the effects of CN supplementation and voluntary exercise on obesity and gut microbiota in high-fat diet (HFD)-fed mice. Consumption of CN increased voluntary wheel running activity. CN intake and exercise together suppressed the increase in body weight and fat mass, and improved glucose tolerance. The fecal gut microbiota was analyzed by sequencing 16S ribosomal RNA genes. Principal component analysis revealed a shift in the microbiota composition resulting from exercise, but not from CN supplementation. Erysipelotrichaceae and Rikenellaceae decreased with exercise. Exercise also increased Ruminococcaceae, whereas exercise and CN intake together increased Eubacteriaceae. These two families are butyrate producers. Exercise increased the amount of acetate in the cecum. These results suggest that CN consumption improves exercise performance and exerts anti-obesity effects by modulating the balance of the gut microbiota.

Resistance training prevents muscle fibrosis and atrophy via down-regulation of C1q-induced Wnt signaling in senescent mice.

Increased complement component 1q (C1q) secretion with aging leads to muscle fibrosis and atrophy whereas resistance training attenuates circulating C1q levels. This study aimed to clarify whether resistance exercise-induced reduction of C1q secretion contributes to the inhibition of fibrosis and atrophy in aged muscles. Young (13-wk-old) and aged (38-wk-old) senescence-accelerated mouse prone 1 mice were randomly assigned to one of 4 groups: a young or aged sedentary control group, or a young or aged resistance training (climbing a ladder 3 d/wk for 12 wk) group. We found that resistance training ameliorated muscle fibrosis and atrophy in aged mice, concomitant with decreased circulating and muscle C1q levels and attenuated activation of muscle Wnt signaling (glycogen synthase kinase ß/ß-catenin), including ß-catenin in satellite (Pax7+/DAPI+) and fibroblast (vimentin+/DAPI+) cells. Furthermore, during muscle regeneration after mice were injured by cardiotoxin injection, we observed a reduction in circulating C1q levels, the inhibition of muscle fibrosis and repair, and decreased in the activation of muscle cytoplasmic and nuclear ß-catenin in aged mice from the resistance training group, but these effects were cancelled by a single preadministration of exogenous recombinant C1q. In addition, resistance training attenuated aging-related muscle loss concomitant with decreased expression of both muscle ring-finger protein 1 and muscle atrophy F-box in the muscle. Thus, resistance training-induced changes in circulating C1q levels may contribute to the prevention of muscle fibrosis and atrophy via muscle Wnt signaling in senescent mice.-Horii, N., Uchida, M., Hasegawa, N., Fujie, S., Oyanagi, E., Yano, H., Hashimoto, T., Iemitsu, M. Resistance training prevents muscle fibrosis and atrophy via down-regulation of C1q-induced Wnt signaling in senescent mice.

High sex hormone-binding globulin concentration is a risk factor for high fibrosis-4 index in middle-aged Japanese men.

Low endogenous testosterone and sex hormone-binding globulin (SHBG) concentrations have been reported to be associated with metabolic syndrome (MetS) and non-alcoholic fatty liver disease (NAFLD). However, little is known about the relationships between testosterone or SHBG and liver fibrosis in NAFLD. Thus, we aimed to clarify the relationships between serum testosterone or SHBG concentration and fibrosis-4 (FIB-4) index, a marker of liver fibrosis. Serum testosterone was assayed in various forms (total testosterone [TT], calculated free testosterone [cFT], calculated bioavailable testosterone [cbT], and SHBG) and metabolic markers were also measured in 363 Japanese men (mean age 51.1 ± 8.7 years) at routine health examinations. We then attempted to identify the factors contributing to liver fibrosis by investigating the associations between the metabolic markers, including testosterone, and FIB-4 index. People with a relatively high FIB-4 index (≥1.3) demonstrated lower cFT, cbT, homeostasis model assessment (HOMA)-ß, low-density lipoprotein-cholesterol, and blood urea nitrogen, but higher SHBG, than those with a lower FIB-4 index (<1.3). There were no significant differences in HbA1c, fasting glucose concentration, HOMA-R, or metabolic syndrome prevalence between the two groups. Binary regression analysis revealed that SHBG ≥52 nmol/L and cFT <8.0 ng/dL were statistically significant risk factors for FIB-4 index ≥1.3. Receiver operating characteristic analysis revealed that cFT <7.62 ng/dL (area under the curve [AUC] = 0.639) and SHBG ≥49.8 nmol/L (AUC = 0.649) were the strongest risk factors for FIB-4 index ≥1.3. In contrast to previous findings showing low SHBG concentrations in NAFLD, we provide evidence that high SHBG and low bioactive testosterone are associated with liver fibrosis.

Palmitoleic acid induces the cardiac mitochondrial membrane permeability transition despite the presence of L-carnitine.

Although palmitoleic acid (C16:1) is associated with arrhythmias, and increases in an age-dependent matter, the effects of L-carnitine, which is essential for the transport of long-chain fatty acids into the mitochondria, are unclear. It has been postulated that L-carnitine may attenuate palmitate (C16:0)-induced mitochondrial dysfunction and the apoptosis of cardiomyocytes. The aim of this study was to elucidate the activity of L-carnitine in the prevention of the palmitoleic acid-induced mitochondrial membrane permeability transition and cytochrome c release using isolated cardiac mitochondria from rats. Palmitoleoyl-CoA-induced mitochondrial respiration was not accelerated by L-carnitine treatment, and this respiration was slightly inhibited by oligomycin, which is an inhibitor of ATP synthase. Despite pretreatment with L-carnitine, the mitochondrial membrane potential decreased and mitochondrial swelling was induced by palmitoleoyl-CoA. In the presence of a combination of L-carnitine and tiron, a free radical scavenger, there was attenuated mitochondrial swelling and cytochrome c release following palmitoleoyl-CoA treatment. We concluded that palmitoleic acid, but not palmitate, induces the cardiac mitochondrial membrane permeability transition despite the presence of L-carnitine.