Inhibition of phosphoinositide 3-kinase/protein kinase B signaling hampers the vasopressin-dependent stimulation of myogenic differentiation

Arginine-vasopressin (AVP) promotes muscle differentiation, hypertrophy, and regeneration through the combined activation of the calcineurin and Calcium/Calmodulin-dependent Protein Kinase (CaMK) pathways. The AVP system is impaired in several neuromuscular diseases, suggesting that AVP may act as a physiological factor in skeletal muscle. Since the Phosphoinositide 3-kinases/Protein Kinase B/mammalian Target Of Rapamycin (PI3K/Akt/mTOR) signaling plays a significant role in regulating muscle mass, we evaluated its role in the AVP myogenic effect. In L6 cells AKT1 expression was knocked down, and the AVP-dependent expression of mTOR and Forkhead box O3 (FoxO) was analyzed by Western blotting. The effect of the PI3K inhibitor LY294002 was evaluated by cellular and molecular techniques. Akt knockdown hampered the AVP-dependent mTOR expression while increased the levels of FoxO transcription factor. LY294002 treatment inhibited the AVP-dependent expression of Myocyte Enhancer Factor-2 (MEF2) and myogenin and prevented the nuclear translocation of MEF2. LY294002 also repressed the AVP-dependent nuclear export of histone deacetylase 4 (HDAC4) interfering with the formation of multifactorial complexes on the myogenin promoter. We demonstrate that the PI3K/Akt pathway is essential for the full myogenic effect of AVP and that, by targeting this pathway, one may highlight novel strategies to counteract muscle wasting in aging or neuromuscular disorders

A longitudinal study defined circulating microRNAs as reliable biomarkers for disease prognosis and progression in ALS human patients

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease associated with motor neuron degeneration, muscle atrophy and paralysis. To date, multiple panels of biomarkers have been described in ALS patients and murine models. Nevertheless, none of them has sufficient specificity and thus the molecular signature for ALS prognosis and progression remains to be elucidated. Here we overcome this limitation through a longitudinal study, analyzing serum levels of circulating miRNAs, stable molecules that are recently used as promising biomarkers for many types of human disorders, in ALS patients during the progression of the pathology. We performed next-generation sequencing (NGS) analysis and absolute RT quantification of serum samples of ALS patients and healthy controls. The expression levels of five selected miRNAs were quantitatively analyzed during disease progression in each patient and we demonstrated that high levels of miR-206, miR-133a and miR-151a-5p can predict a slower clinical decline of patient functionality. In particular, we found that miR-206 and miR-151a-5p serum levels were significantly up-regulated at the mild stage of ALS pathology, to decrease in the following moderate and severe stages, whereas the expression levels of miR-133a and miR-199a-5p remained low throughout the course of the disease, showing a diagnostic significance in moderate and severe stages for miR-133a and in mild and terminal ones for miR-199a-5p. Moreover, we found that miR-423\u20133p and 151a-5p were significantly downregulated respectively in mild and terminal stages of the disease. These data suggest that these miRNAs represent potential prognostic markers for ALS disease

Effects of increasing dietary level of organic acids and nature-identical compounds on growth, intestinal cytokine gene expression and gut microbiota of rainbow trout (Oncorhynchus mykiss) reared at normal and high temperature

Organic acids (OA) and nature-identical compounds (NIC) such as monoterpenes and aldehydes are well-known growth and health promoters in terrestrial livestock while their application for fish production is recent and their mechanisms of action require further study. Hence, this study tested the increasing dietary level (D0, D250, D500, D1000; 0, 250, 500 and 1000 mg kg feed−1 respectively) of a microencapsulated blend containing citric and sorbic acid, thymol and vanillin over 82 days on rainbow trout to assess the effects on growth, feed utilization, intestine cytokine gene expression and gut microbiota (GM). Furthermore, the effects on intestinal cytokine gene expression and GM were also explored after one week at high water temperature (23 °C). OA and NIC improved specific growth rate (SGR) and feed conversion rate (FCR) during the second half (day 40–82) of the feeding trial, while at the end of the trial protein (PER) and lipid efficiency (LER) increased with increasing dietary level. GM diversity and composition and cytokine gene expression analysis showed no significant differences in fish fed with increasing doses of OA and NIC (82 days) demonstrating the absence of inflammatory activity in the intestinal mucosa. Although there were no statistical differences, GM structure showed a tendency in clustering D0 group separately from the other dietary groups and a trend towards reduction of Streptococcus spp. was observed in the D250 and D1000 groups. After exposure to high water temperature, lower GM diversity and increased gene expression of inflammatory intestinal cytokines were observed for both inclusions (D0 vs. D1000) compared to groups in standard condition. However, the gene up-regulation involved a limited number of cytokines showing the absence of a substantial inflammation process able to compromise the functional activity of the intestine. Despite further study should be conducted to fully clarify this mechanism, cytokines up-regulation seems to be concomitant to the reduction of the GM diversity and, particularly, to the reduction of specific lactic acid bacteria such as Leuconostoc. The application of the microencapsulate blend tested can be a useful strategy to improve growth and feed utilization in rainbow trout under normal temperature conditions. According to the results organic acids and nature-identical compounds did not revert the effects triggered by the increased temperature of water

Distinct Properties of Hexameric but Functionally Conserved Mycobacterium tuberculosis Transcription-Repair Coupling Factor

Transcription coupled nucleotide excision repair (TC-NER) is involved in correcting UV-induced damage and other road-blocks encountered in the transcribed strand. Mutation frequency decline (Mfd) is a transcription repair coupling factor, involved in repair of template strand during transcription. Mfd from M. tuberculosis (MtbMfd) is 1234 amino-acids long harboring characteristic modules for different activities. Mtbmfd complemented Escherichia coli mfd (Ecomfd) deficient strain, enhanced survival of UV irradiated cells and increased the road-block repression in vivo. The protein exhibited ATPase activity, which was stimulated ∼1.5-fold in the presence of DNA. While the C-terminal domain (CTD) comprising amino acids 630 to 1234 showed ∼2-fold elevated ATPase activity than MtbMfd, the N-terminal domain (NTD) containing the first 433 amino acid residues was able to bind ATP but deficient in hydrolysis. Overexpression of NTD of MtbMfd led to growth defect and hypersensitivity to UV light. Deletion of 184 amino acids from the C-terminal end of MtbMfd (MfdΔC) increased the ATPase activity by ∼10-fold and correspondingly exhibited efficient translocation along DNA as compared to the MtbMfd and CTD. Surprisingly, MtbMfd was found to be distributed in monomer and hexamer forms both in vivo and in vitro and the monomer showed increased susceptibility to proteases compared to the hexamer. MfdΔC, on the other hand, was predominantly monomeric in solution implicating the extreme C-terminal region in oligomerization of the protein. Thus, although the MtbMfd resembles EcoMfd in many of its reaction characteristics, some of its hitherto unknown distinct properties hint at its species specific role in mycobacteria during transcription-coupled repair

Italy: The Archaeology of Palaeoshorelines, Coastal Caves and Seafaring Connections

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Apolipoprotein E gene polymorphism modifies fasting total cholesterol concentrations in response to replacement of dietary saturated with monounsaturated fatty acids in adults at moderate cardiovascular disease risk

Consumption of ≤10% total energy from fat as saturated fatty acids (SFA) is recommended for cardiovascular disease risk reduction in the UK; however there is no clear guidance on the optimum replacement nutrient. Lipid-associated single-nucleotide polymorphisms (SNPs) have been shown to modify the lipid responses to dietary fat interventions. Hence, we performed a retrospective analysis in 120 participants from the Dietary Intervention and VAScular function (DIVAS) study to investigate whether lipoprotein lipase (LPL) and apolipoprotein E (APOE) SNPs modify the fasting lipid response to replacement of SFA with monounsaturated (MUFA) or n-6 polyunsaturated (PUFA) fatty acids. The DIVAS study was a randomized, single-blinded, parallel dietary intervention study performed in adults with a moderate cardiovascular risk who received one of three isoenergetic diets rich in SFA, MUFA or n-6 PUFA for 16 weeks. After the 16-week intervention, a significant diet-gene interaction was observed for changes in fasting total cholesterol (P = 0.001). For the APOE SNP rs1064725, only TT homozygotes showed a significant reduction in total cholesterol after the MUFA diet (n = 33; -0.71 ± 1.88 mmol/l) compared to the SFA (n = 38; 0.34 ± 0.55 mmol/l) or n-6 PUFA diets (n = 37; -0.08 ± 0.73 mmol/l) (P = 0.004). None of the interactions were statistically significant for the other SNPs. In summary, our findings have demonstrated a greater sensitivity of the APOE SNP rs1064725 to dietary fat composition, with a total cholesterol lowering effect observed following substitution of SFA with MUFA but not n-6 PUFA. Further large intervention studies incorporating prospective genotyping are required to confirm or refute our findings. The trial was registered at www.clinicaltrials.gov as NCT01478958

Adaptation of Mouse Skeletal Muscle to Long-Term Microgravity in the MDS Mission

The effect of microgravity on skeletal muscles has so far been examined in rat and mice only after short-term (5–20 day) spaceflights. The mice drawer system (MDS) program, sponsored by Italian Space Agency, for the first time aimed to investigate the consequences of long-term (91 days) exposure to microgravity in mice within the International Space Station. Muscle atrophy was present indistinctly in all fiber types of the slow-twitch soleus muscle, but was only slightly greater than that observed after 20 days of spaceflight. Myosin heavy chain analysis indicated a concomitant slow-to-fast transition of soleus. In addition, spaceflight induced translocation of sarcolemmal nitric oxide synthase-1 (NOS1) into the cytosol in soleus but not in the fast-twitch extensor digitorum longus (EDL) muscle. Most of the sarcolemmal ion channel subunits were up-regulated, more in soleus than EDL, whereas Ca2+-activated K+ channels were down-regulated, consistent with the phenotype transition. Gene expression of the atrophy-related ubiquitin-ligases was up-regulated in both spaceflown soleus and EDL muscles, whereas autophagy genes were in the control range. Muscle-specific IGF-1 and interleukin-6 were down-regulated in soleus but up-regulated in EDL. Also, various stress-related genes were up-regulated in spaceflown EDL, not in soleus. Altogether, these results suggest that EDL muscle may resist to microgravity-induced atrophy by activating compensatory and protective pathways. Our study shows the extended sensitivity of antigravity soleus muscle after prolonged exposition to microgravity, suggests possible mechanisms accounting for the resistance of EDL, and individuates some molecular targets for the development of countermeasures