MOTS-c promotes muscle differentiation in vitro.

MOTS-c (mitochondrial open reading frame of the 12 S rRNA-c) is a newly discovered peptide that has been shown to have a protective role in whole-body metabolic homeostasis. This could be a consequence of the effect of MOTS-c on muscle tissue. Here, we investigated the role of MOTS-c in the differentiation of human (LHCN-M2) and murine (C2C12) muscle progenitor cells. Cells were treated with peptides at the onset of differentiation or after myotubes had been formed. We identified in silico a putative Src Homology 2 (SH2) binding motif in the YIFY region of the MOTS-c sequence, and created a Y8F mutant MOTS-c peptide to explore the role of this region. In both cellular models, treatment with wild-type MOTS-c peptide increased myotube formation whereas treatment with the Y8F peptide did not. MOTS-c wild-type, but not Y8F peptide, also protected against interleukin-6 (IL-6)-induced reduction of nuclear myogenin staining in myocytes. Thus, we investigated whether MOTS-c interacts with the IL-6/Janus kinase/ Signal transducer and activator of transcription 3 (STAT3) pathway, and found that MOTS-c, but not the Y8F peptide, blocked the transcriptional activity of STAT3 induced by IL-6. Altogether, our findings suggest that, in muscle cells, MOTS-c interacts with STAT3 via the putative SH2 binding motif in the YIFY region to reduce STAT3 transcriptional activity, which enhances myotube formation. This newly discovered mechanism of action highlights MOTS-c as a potential therapeutic target against muscle-wasting in several diseases.

Expression of the human TIMM23 and TIMM23B genes is regulated by the GABP transcription factor.

The TIM23 protein is a key component of the mitochondrial import machinery in yeast and mammals. TIM23 is the channel-forming subunit of the translocase of the inner mitochondrial membrane (TIM23) complex, which mediates preprotein translocation across the mitochondrial inner membrane. In this paper, we aimed to characterize the promoter region of the highly similar human TIM23 orthologs: TIMM23 and TIMM23B. Bioinformatic analysis revealed putative sites for the GA-binding protein (GABP) and the recombination signal binding protein for immunoglobulin kappa J (RBPJ) transcription factors in both promoters. Luciferase reporter assays, electrophoretic mobility shift assays, and chromatin immunoprecipitation experiments showed three functional sites for GABP and one functional site for RBPJ in both promoters. Moreover, silencing of GABPA, the gene encoding the DNA-binding subunit of the GABP transcription factor, resulted in reduced expression of TIMM23 and TIMM23B. Our results show an essential role of GABP in activating TIMM23 expression. More broadly, they suggest that physiological signals involved in activating mitochondrial biogenesis and oxidative function also enhance the transcription but not the protein level of TIMM23, which is essential for maintaining mitochondrial function and homeostasis.

An Eighteen-Minute Submaximal Exercise Test to Assess Cardiac Fitness in Response to Aerobic Training.

Romagnoli, M, Alis, R, Sanchis-Gomar, F, Lippi, G, and Arduini, A. An 18-minute submaximal exercise test to assess cardiac fitness in response to aerobic training. J Strength Cond Res 32(10): 2846-2852, 2018-We aimed to evaluate the utility of a submaximal heart rate recovery (HRR) test to monitor changes in cardiac fitness after aerobic training. Twenty healthy subjects were assigned to a control (n = 10) or a training (n = 10) group. Subjects in the training group performed 8 weeks of bicycle training, followed by 8 weeks of detraining. Heart rate recovery was assessed after exercises at 65% and 80% HRmax. The HRR test was performed at weeks 0 (W0), 4 (W4), 8 (W8), and 16 (W16) in the training group and at W0 and W8 in the control group. Heart rate recovery indices changed in response to training and detraining. Absolute HRR at 60, 120, and 180 seconds after exercise increased at both exercise intensities at W8 of training (p < 0.01, W8 vs. W0) and returned to the pretraining level after detraining (p > 0.05, W16 vs. W0). Time constants of fast HRR recovery (<1 minute) changed with training (p < 0.05-0.01, W8 vs. W0) and detraining (p > 0.05, W16 vs. W0) but only at 65% HRmax. At the end of the 3-minute recovery period, the predicted heart rate (HR) value (A0) and the HR recovered (Amax) from the monoexponential analysis changed with training (p < 0.05-0.01, W8 vs. W0) and detraining (p > 0.05, W16 vs. W0). We conclude that this novel submaximal HRR test is highly sensitive for monitoring cardiac fitness during training and detraining in healthy people. Because this test is simple, inexpensive, and the data are reliable and easy to analyze, we hope that it may be of interest to the sports science community.

The MDS and EVI1 complex locus (MECOM) isoforms regulate their own transcription and have different roles in the transformation of hematopoietic stem and progenitor cells.

Transcriptional activation of the EVI1 oncogene (3q26) leads to aggressive forms of human acute myeloid leukemia (AML). However, the mechanism of EVI1-mediated leukemogenesis has not been fully elucidated. Previously, by characterizing the EVI1 promoter, we have shown that RUNX1 and ELK1 directly regulate EVI1 transcription. Intriguingly, bioinformatic analysis of the EVI1 promoter region identified the presence of several EVI1 potential binding sites. Thus, we hypothesized that EVI1 could bind to these sites regulating its own transcription. In this study, we show that there is a functional interaction between EVI1 and its promoter, and that the different EVI1 isoforms (EVI1-145kDa, EVI1-Δ324 and MDS1-EVI1) regulate the transcription of EVI1 transcripts through distinct promoter regions. Moreover, we determine that the EVI1-145kDa isoform activates EVI1 transcription, whereas EVI1-Δ324 and MDS1-EVI1 act as repressors. Finally, we demonstrate that these EVI1 isoforms are involved in cell transformation; functional experiments show that EVI1-145kDa prolongs the maintenance of hematopoietic stem and progenitor cells; conversely, MDS1-EVI1 repressed hematopoietic stem and progenitor colony replating capacity. We demonstrate for the first time that EVI1 acts as a regulator of its own expression, highlighting the complex regulation of EVI1, and open new directions to better understand the mechanisms of EVI1 overexpressing leukemias.

Immune Complex Membranoproliferative Glomerulonephritis Associated with Transjugular Intrahepatic Portosystemic Shunts in Alcoholic Cirrhosis: Two Case Reports.

OBJECTIVE: To report on 2 patients with alcoholic cirrhosis who were treated with transjugular intrahepatic portosystemic shunt (TIPS) placement. CLINICAL PRESENTATION AND INTERVENTION: The 2 patients had a history of alcoholic cirrhosis, and TIPS surgery was performed on them. In both cases, 4 months after TIPS placement, proteinuria was observed along with histological alterations characteristic of immune complex membranoproliferative glomerulonephritis (MPGN). CONCLUSION: The TIPS in one patient was successful without immediate complications, while the other patient was referred for a combined liver-kidney transplant. In both cases, immune complex MPGN might have developed after TIPS placement probably due to a reduced immune complex clearance.

Alpha-amylase serum levels in professional soccer players are not related with physical fitness.

BACKGORUND: Recent evidence has showed that serum or salivary values of α-amylase predict endurance running performance. In this study we investigate whether serum α-amylase concentration may be associated with training status during a competitive season and after a detraining period in professional soccer players. METHODS: The study population consisted in 15 male professional soccer players from an Italian major league team (age [mean±SD] 27±5 years, weight 76.9±4.1 kg, height 1.82±0.05 m). Serum α-amylase levels were measured 3 times during the last part of a competitive season (January, March and May) and just before preseason training (July). RESULTS: Metabolic and cardiovascular fitness of soccer players was improved during the last part of the season. The levels of α-amylase did not change significantly throughout the study period (χ2=7.331, P=0.062), nor they were found to be associated with variation of physical fitness and training status. CONCLUSIONS: The α-amylase fluctuations throughout a competitive season and after vacation time were meaningless in professional soccer players. No significant associations with physical fitness variations could be observed. These results suggest that α-amylase concentration may be a useful parameter for identifying individual inclination to endurance exercise, but not for predicting actual training status.

Muscle-Related Polymorphisms (MSTN rs1805086 and ACTN3 rs1815739) Are Not Associated with Exceptional Longevity in Japanese Centenarians.

Myostatin (MSTN) and α-actinin-3 (ACTN3) genes are potentially associated with preservation of muscle mass and oxidative capacity, respectively. To explore the possible role of these genes in exceptional longevity (EL), the allele/genotype frequency distribution of two polymorphisms in MSTN (rs1805086, K153R) and ACTN3 (rs1815739, R577X) was studied in Japanese centenarians of both sexes (n = 742) and healthy controls (n = 814). The rs1805086 R-allele (theoretically associated with muscle mass preservation at the expense of oxidative capacity) was virtually absent in the two groups, where genotype distributions were virtually identical. Likewise, no differences in allele (p = 0.838 (women); p = 0.193 (men); p = 0.587 (both sexes)) or genotype distribution were found between groups for ACTN3 rs1815739 (p = 0.975 (women), p = 0.136 (men), p = 0.752 (both sexes)). Of note, however, the frequency of the rs1805086 R-allele observed here is the lowest been reported to date whereas that of the 'highly oxidative/efficient' rs1815739 XX genotype in Japanese male centenarians (33.3%) or supercentenarians of both sexes (≥110 years) are the highest (32.6%), for a non-American population. No definite conclusions can be inferred in relation to EL owing to its lack of association with both rs1815739 and rs1805086. However, it cannot be excluded that these gene variants could eventually be related to a "healthy" metabolic phenotype in the Japanese population. Further research might determine if such metabolic profile is among the factors that can potentially predispose these individuals to live longer than Caucasians and what genetic variants might be actually involved.

No evidence of adverse cardiac remodeling in former elite endurance athletes.

BACKGROUND: The impact of high exercise loads on a previously healthy heart remains controversial. We examined the consequences of decades of strenuous endurance exercise at the highest competition level on heart dimensions and volumes as well as on serum biomarkers of cardiac fibrosis/remodeling. METHODS AND RESULTS: We compared echocardiographic measurements and serum biomarkers of cardiac fibrosis/remodeling [troponin I, galectin-3, matrix metallopeptidase-2 and -9, N-terminal pro-brain natriuretic peptide, carboxy-terminal propeptide of type I procollagen, and soluble suppressor of tumorigenicity-2 (sST-2)/interleukin(IL)-1R4] in 53 male athletes [11 former professional ('elite') and 42 amateur-level ('sub-elite') cyclists or runners, aged 40-70years] and 18 aged-matched controls. A subset of 15 subjects (5 controls, 3 sub-elite and 7 elite athletes) also underwent cardiac magnetic resonance imaging (cMRI). Elite and sub-elite athletes had greater echocardiography-determined left ventricular myocardial mass indexed to body surface area than controls (113±22, 115.2±23.1 and 94.8±21g/m(2), respectively, p=0.008 for group effect), with similar results for left (50.5±4.4, 48.2±4.3 and 46.4±5.2mm, p=0.008) and right (38.6±3.8, 41.1±5.5 and 34.7±4.3mm, p<0.001) ventricular end-diastolic diameter, and cMRI-determined left atrial volume indexed to body surface area (62.7±8.1, 56.4±16.0 and 39.0±14.1ml/m(2), p=0.026). Two athletes showed a non-coronary pattern of small, fibrotic left ventricular patches detected by late gadolinium enhancement. No group effect was noted for biomarkers. CONCLUSIONS: Regardless of their competition level at a younger age, veteran endurance athletes showed an overall healthy, non-pathological pattern of cardiac remodeling. Nonetheless, the physiopathology of the ventricular fibrotic patches detected warrants further investigation.

Topical application of the Wnt/ß-catenin activator methyl vanillate increases hair count and hair mass index in women with androgenetic alopecia.

BACKGROUND: Activation of the WNT/ß-catenin pathway has emerged as a potential therapeutic target in androgenetic alopecia (AGA). Methyl vanillate (MV) - a safe plant-derived ingredient - has been recently shown to activate the WNT/ß-catenin signaling. Objectives Two distinct substudies were conducted. First, we designed a 6-month, uncontrolled, open-label clinical study to investigate whether topically applied MV may increase hair count and hair mass index (HMI) in female AGA. Second, we conducted a molecular study on the effect of MV on WNT10B mRNA expression in scalp biopsies of women with AGA. METHODS: A total of 20 Caucasian women (age range: 25-57 years) with AGA (Sinclair grade 1-2) were included. The research product was an alcohol-free formulation supplied in the form of a spray containing 0.2% MV as the active ingredient. RESULTS: In the clinical study, hair count and HMI were found to increase at 6 months by 6% (P < 0.01) and 12% (P < 0.001), respectively, compared with baseline. No participant discontinued treatment due to adverse effects, and the overall patient satisfaction was good. At the molecular level, the topical application of the research product resulted in a 32% increase in WNT10B mRNA expression levels in the temporal scalp area (P < 0.001). CONCLUSION: Our pilot data suggest that topical MV can increase hair count and HMI by inducing WNT10B expression in the scalp, potentially serving as a novel treatment strategy for female AGA.

Trace elements levels in centenarian 'dodgers'.

Trace element bioavailability can play a role in several metabolic and physiological pathways known to be altered during the aging process. We aimed to explore the association of trace elements with increased lifespan by analyzing the circulating levels of seven trace elements (Cr, Cu, Fe, Mn, Mo, Se and Zn) in a cohort of healthy centenarians or 'dodgers' (≥100 years, free of major age-related diseases) in comparison with sex-matched younger elderly controls. Centenarians showed significant lower Cu (783.7 (76.7, 1608.9) vs 962.5 (676.3, 2064.4)µg/mL, P<0.001), but higher Fe (1.3 (0.4, 4.7) vs 1.1 (0.5, 8.4)µg/mL, P=0.003) and Se (85.7 (43.0, 256.7) vs 77.8 (24.3, 143.8)ng/mL, P=0.002) values compared with elderly controls. The logistic regression analysis identified the combination of Cu and Se as significant predictor variables associated with successful aging (P=0.001), while receiver operating characteristic (ROC) analysis confirmed that Cu and Se (either alone or in combination) were independent variables associated with healthy aging. An 'improved' trace element profile (reduced Cu and elevated Se, which are involved in key physiological processes) could play a role in the resistance to disease showed by centenarian 'dodgers', and, therefore, at least partly, be involved in the healthy aging phenotype shown by these subjects. These results should be confirmed in larger cohorts of other geographic/ethnic origin and the potential cause-effect association tested in mechanistic experimental settings.

Xanthine Oxidase Pathway and Muscle Damage. Insights from McArdle Disease.

The intent of this article is to summarize current body of knowledge on the potential implication of the xanthine oxidase pathway (XO) on skeletal muscle damage. The possible involvement of the XO pathway in muscle damage is exemplified by the role of XO inhibitors (e.g., allopurinol) in attenuating muscle damage. Reliance on this pathway (as well as on the purine nucleotide cycle) could be exacerbated in conditions of low muscle glycogen availability. Thus, we also summarize current hypotheses on the etiology of both baseline and exertional muscle damage in McArdle disease, a condition caused by inherited deficiency of myophosphorylase. Because myophosphorylase catalyzes the first step of muscle glycogen breakdown, patients are unable to obtain energy from their muscle glycogen stores. Finally, we provide preliminary data from our laboratory on the potential implication of the XO pathway in the muscle damage that is commonly experienced by these patients.

Changes in muscle damage, inflammation, and fatigue-related parameters in young elite soccer players after a match.

BACKGROUND: Professional soccer players are subjected to substantial physical loads during competitive seasons. We aimed to explore the changes induced by a soccer match on muscle damage and inflammation biomarkers, and their relationship with fatigue parameters. METHODS: Twenty young male professional in-field soccer players from an Italian Serie A team (age 17-20 years, weight 73.0±7.0 kg, height 1.81±0.05m) played a 90-minute soccer match. Players' distances and velocities were recorded during the match. Before the match and 30 minutes, 24 and 48 hours after the match, blood samples were drawn and a full blood cell count was determined, along with serum creatine kinase (CK), interleukin 6 (hsIL-6), cortisol and testosterone. At the same time intervals, counter-movement jump (CMJ) performance was recorded. RESULTS: The players covered fewer meters at low velocities in the second period while the meters covered at higher intensity remained unchanged. CMJ height was lower at all postgame time-points compared to the pregame measurement. Immediately after the match, CK, hs-IL6 and neutrophil counts were elevated. 24 and 48 hours after the match, CK and neutrophil counts remained significantly elevated. The distance covered during the game was found to be correlated with the values for postmatch hsIL-6 (ρ=0.521, P=0.027), post 24-hour cortisol (r=0.502, P=0.034) and the increase in cortisol at 48 hours with respect to prematch values (r=0.515, P=0.029). CONCLUSIONS: A soccer match provokes a transient systemic imbalance that results in muscle damage and inflammatory and performance-related parameter changes. HsIL-6 and cortisol could be used to monitor recovery processes and as fatigue markers, even for short time periods.

Microcentrifuge or Automated Hematological Analyzer to Assess Hematocrit in Exercise? Effect on Plasma Volume Loss Calculations.

The assessment of plasma volume loss (∆PV) induced by exercise can be estimated from changes in hematocrit (Htc) and hemoglobin (Hb), and it is essential when investigating the metabolic or biologic response to exercise of circulating biomarkers. We aimed to ascertain whether the estimation of ∆PV may differ when Hb and Htc are determined by automated hematological analyzer (AHA) versus manual methods. Twenty-five healthy male subjects performed a maximal running incremental exercise. Blood samples were taken before exercise, immediately after exercise, and after a 30-min recovery. Hb and Htc (Htc-AHA) were determined by an AHA. Htc was also determined by microcentrifugation (Htc-M). The ∆PV immediately after exercise and after recovery was calculated. The serum concentrations of several specimens were determined and corrected for ∆PV derived from Htc-AHA (∆PVAHA) and from Htc-M (∆PVM). Htc-M was found to be higher than Htc-AHA at all time points (p < 0.001). However, no differences were observed between ∆PVM and ∆PVAHA either post exercise (∆PVM -12.43% versus ∆PVAHA -12.41%, p = 0.929) or after recovery (∆PVM 1.47% versus ∆PVAHA 1.97%, p = 0.171). No significant differences were found between both ∆PV corrected concentrations of any biomarker (p ≥ 0.076). In conclusion, both AHA and the microcentrifuge may be reliably used to estimate ∆PV during exercise.

Blood and Urinary Abnormalities Induced During and After 24-Hour Continuous Running: A Case Report.

In this reported clinical case, a healthy and well-trained male subject [aged 37 years, maximal oxygen uptake (V[Combining Dot Above]O2max) 64 mL·kg·min] ran for 23 hours and 35 minutes covering 160 km (6.7 km/h average running speed). The analysis of hematological and biochemical parameters 3 days before the event, just after termination of exercise, and after 24 and 48 hours of recovery revealed important changes on muscle and liver function, and hemolysis. The analysis of urine sediments showed an increment of red and white blood cells filtrations, compatible with transient nephritis. After 48 hours, most of these alterations were recovered. Physicians and health professionals who monitor such athletic events should be aware that these athletes could exhibit transient symptoms compatible with severe pathologies and diseases, although the genesis of these blood and urinary abnormalities are attributable to transient physiological adaptations rather to pathological status.

Effect of training status on the changes in platelet parameters induced by short-duration exhaustive exercise.

It is now well known that hemostasis is directly involved in the benefits induced by physical activity. It has recently been shown that the baseline mean platelet volume (MPV) may be a predictor of endurance performance. We aimed to explore whether platelet parameters are associated with VO2max as well as running duration and speed in a short-duration exhaustive exercise test. Thirty healthy male subjects (10 sedentary and 20 trained) performed an incremental running test until exhaustion. MPV, platelet distribution width (PDW), platelet (Plt) count, and plateletcrit (Pct) were determined before exercise, immediately after exercise and after 30' recovery. Training status did not produce any difference in the baseline levels or in the post-exercise increases found in all the parameters tested. VO2max, test duration, and running speed were not correlated with any baseline parameter. Although MPV was found to be a predictor of endurance performance in long-duration exercise, the results of the present study are consistent with the hypothesis that MPV may not be a significant marker of performance in short-duration exhaustive exercise. Likewise, more research is needed to ascertain whether platelet activation is a reliable performance predictor in other exercise settings.

Galectin-3, osteopontin and successful aging.

BACKGROUND: Individuals who reach exceptional longevity (100+ years of age) free of common chronic age diseases (i.e. 'dodgers') arguably represent the paradigm of successful aging in humans. As such, identification of potential biomarkers associated with this phenomenon is of medical interest. METHODS: We measured serum levels of galectin-3 and osteopontin, both of which have been shown to be linked with major chronic or aging-related disorders in younger populations, in centenarian 'dodgers' (n=81; 40 men; 100-104 years) and healthy controls (n=41; 24 men, 70-80 years). RESULTS: Both biomarkers showed significantly lower values (p<0.001) in the former (galectin-3: 2.4±1.7 vs. 4.8±2.8 ng/mL; osteopontin: 38.1±27.7 vs. 72.6±33.1 µg/mL). Logistic regression analysis identified the combination of these two biomarkers as a significant predictor variable associated with successful aging regardless of sex (p<0.001). The area under the curve (AUC) classified the ability of galectin-3 and osteopontin to predict the likelihood of successful aging as 'fair' (AUC=0.75) and 'good' (AUC=0.80), respectively. Particularly, the combination of the two biomarkers showed good discriminatory power for successful aging (AUC=0.86), with sensitivity=83% and specificity=74%. CONCLUSIONS: Lower levels of both galectin-3 and osteopontin are associated with successful aging, representing potential biomarkers of this condition. Our cross-sectional data must be however approached with caution. Further research is necessary to replicate the present preliminary results in other cohorts and to identify the potential use of galectin-3 and osteopontin as potential targets (or at least predictors) in future personalized anti-aging therapies.

The mitochondrial-derived peptide MOTS-c: a player in exceptional longevity?

Mitochondrial-derived peptides (MDP) are encoded by functional short open reading frames in the mitochondrial DNA (mtDNA). These include humanin, and the recently discovered mitochondrial open reading frame of the 12S rRNA-c (MOTS-c). Although more research is needed, we suggest that the m.1382A>C polymorphism located in the MOTS-c encoding mtDNA, which is specific for the Northeast Asian population, may be among the putative biological mechanisms explaining the high longevity of Japanese people.