Muscular Protein Synthesis Research Articles

МИКРОБИОТА КИШЕЧНИКА И ЗДОРОВЬЕ СПОРТСМЕНОВ

Purpose: A synthesis of world literature on actual knowledge of intestine microbiota influence on athletes’ health. Methods and materials: National and foreign literature on actual knowledge of intestine microbiota influence on athletes’ health was analyzed. MEDLINE, Embase, Scopus, Web of Science, eLIBRARY, PubMed data Google Academy data bases were used for searching the literature for the period from 2012 to 2024. The following key words and their combinations were applied for search: “athletes”, “gut microbiota “, “butyrate”. Results: A microbiota is a key factor of human organism homeostasis maintenance. It provides next functions: energy metabolism, maturation and maintenance of immune system, synthesis of vitamins, regulation of bile acids reabsorption in intestine and lots of other functions. Furthermore, bacteria produce some human hormones analogues: serotonin, histamine, dopamine, norepinephrine, testosterone. According to the recent information, intestine microbiota modification could provide a beneficial influence on human organism that cause a sport results improvement. Modulation of immune response, oxidative stress, metabolic processes and nutrients bioavailability is a general mechanism of microbiota influence on training adaptation. Microbiome affects the muscular protein synthesis, biogenesis and function of mitochondria and the muscular glycogen accumulation. Conclusion: Currently there is a necessity of further investigations of “microbiome-muscles” relationship.

Amiloride ameliorates muscle wasting in cancer cachexia through inhibiting tumor-derived exosome release

BackgroundCancer cachexia (CAC) reduces patient survival and quality of life. Developments of efficient therapeutic strategies are required for the CAC treatments. This long-term process could be shortened by the drug-repositioning approach which exploits old drugs approved for non-cachexia disease. Amiloride, a diuretic drug, is clinically used for treatments of hypertension and edema due to heart failure. Here, we explored the effects of the amiloride treatment for ameliorating muscle wasting in murine models of cancer cachexia.MethodsThe CT26 and LLC tumor cells were subcutaneously injected into mice to induce colon cancer cachexia and lung cancer cachexia, respectively. Amiloride was intraperitoneally injected daily once tumors were formed. Cachexia features of the CT26 model and the LLC model were separately characterized by phenotypic, histopathologic and biochemical analyses. Plasma exosomes and muscle atrophy-related proteins were quantitatively analyzed. Integrative NMR-based metabolomic and transcriptomic analyses were conducted to identify significantly altered metabolic pathways and distinctly changed metabolism-related biological processes in gastrocnemius.ResultsThe CT26 and LLC cachexia models displayed prominent cachexia features including decreases in body weight, skeletal muscle, adipose tissue, and muscle strength. The amiloride treatment in tumor-bearing mice distinctly alleviated muscle atrophy and relieved cachexia-related features without affecting tumor growth. Both the CT26 and LLC cachexia mice showed increased plasma exosome densities which were largely derived from tumors. Significantly, the amiloride treatment inhibited tumor-derived exosome release, which did not obviously affect exosome secretion from non-neoplastic tissues or induce observable systemic toxicities in normal healthy mice. Integrative-omics revealed significant metabolic impairments in cachectic gastrocnemius, including promoted muscular catabolism, inhibited muscular protein synthesis, blocked glycolysis, and impeded ketone body oxidation. The amiloride treatment evidently improved the metabolic impairments in cachectic gastrocnemius.ConclusionsAmiloride ameliorates cachectic muscle wasting and alleviates cancer cachexia progression through inhibiting tumor-derived exosome release. Our results are beneficial to understanding the underlying molecular mechanisms, shedding light on the potentials of amiloride in cachexia therapy.

Six1 induces protein synthesis signaling expression in duck myoblasts mainly via up-regulation of mTOR.

As a critical transcription factor, Six1 plays an important role in the regulation of myogenesis and muscle development. However, little is known about its regulatory mechanism associated with muscular protein synthesis. The objective of this study was to investigate the effects of overexpression ofSix1 on the expression of key protein metabolism-related genes in duck myoblasts. Through an experimental model where duck myoblasts were transfected with a pEGFP-duSix1 construct, we found that overexpression of duckSix1 could enhance cell proliferation activity and increase mRNA expression levels of key genes involved in the PI3K/Akt/mTOR signaling pathway, while the expression of FOXO1, MuRF1and MAFbx was not significantly altered, indicating thatSix1 could promote protein synthesis in myoblasts through up-regulating the expression of several related genes. Additionally, in duck myoblasts treated with LY294002 and rapamycin, the specific inhibitors ofPI3K and mTOR, respectively, the overexpression of Six1 could significantly ameliorate inhibitive effects of these inhibitors on protein synthesis. Especially, the mRNA expression levels of mTOR and S6K1 were observed to undergo a visible change, and a significant increase in protein expression of S6K1 was seen. These data suggested that Six1plays an important role in protein synthesis, which may be mainly due to activation of the mTOR signaling pathway.

Systematic review of the effect of propanolol on hypermetabolism in burn injuries

BackgroundThe use of propranolol has been proposed to reduce the hypermetabolic response of patients with burn injuries. ObjectivesTo review the studies published up to December 2013 on the effects of propranolol in burn patients. MethodsA PubMed search was conducted using the terms “burns”, “thermal injury”, “beta-blocker” and “propranolol”, with the filters “human” and “English” and “Spanish”. A total of 42 citations were retrieved, 15 of which were randomized clinical trials. The main results are summarized. Main resultsPropranolol at doses adjusted to decrease the heart rate by 20% of the baseline value (4–6mg/kg/day p.o.) reduces supraphysiological thermogenesis, cardiac work, resting energy expenditure and peripheral lipolysis. It likewise increases the efficiency of muscular protein synthesis and reduces central mass accretion. Most studies have been conducted in pediatric burn patients. ConclusionsPropranolol reduces the hypermetabolic response in pediatric burn patients. More studies on its effects in adult burn patients are needed.

Revisión sistemática del efecto del propranolol sobre el hipermetabolismo del quemado

BackgroundThe use of propranolol has been proposed to reduce the hypermetabolic response of patients with burn injuries. ObjectivesTo review the studies published up to December 2013 on the effects of propranolol in burn patients. MethodsA PubMed search was conducted using the terms «burns», «thermal injury», «beta-blocker» and «propranolol», with the filters «human» and «English» and «Spanish». A total of 42 citations were retrieved, 15 of which were randomized clinical trials. The main results are summarized. Main resultsPropranolol at doses adjusted to decrease the heart rate by 20% of the baseline value (4-6mg/kg/day p.o.) reduces supraphysiological thermogenesis, cardiac work, resting energy expenditure and peripheral lipolysis. It likewise increases the efficiency of muscular protein synthesis and reduces central mass accretion. Most studies have been conducted in pediatric burn patients. ConclusionsPropranolol reduces the hypermetabolic response in pediatric burn patients. More studies on its effects in adult burn patients are needed.

Cryptosporidium infection impairs growth and muscular protein synthesis in suckling rats

This study aimed to explore the metabolic consequences of cryptosporidiosis in an acute experimental model both at the peak of infection and after parasite clearance. Four-day-old suckling rats were infected with 10(6) oocysts of Cryptosporidium parvum. At the peak of infection (day 8 PI), C. parvum resulted in a dramatic reduction both in nutrient intake (-50%) and body weight (16.3+/-5.2 vs 27.3+/-1.0 g, P<0.01) with a decrease in both lean body mass and adipose tissue. Muscular fractional and absolute synthesis rate were reduced (-15 and -55%, respectively). After parasite clearance (day 17 PI), body weight remained reduced in formerly infected animals (37.8+/-8.0 vs 47.8+/-4.2 g, P<0.01) whereas nutrient intake normalized and fractional synthesis rate slightly increased (+22%) compared to controls. Overall, our results show that the impact and consequences of cryptosporidiosis are far greater than generally appreciated, leading to major malnutrition in suckling rats.

Improvement in muscular performance and decrease in tumor necrosis factor level in old age after antioxidant treatment

Aging-related loss of muscle function is a predictor of mortality and a surrogate parameter of the aging process. Its consequences include a high risk for falls, hip fractures, and loss of autonomy. Aging is associated with changes in the oxidant/antioxidant balance including a decrease in plasma thiol (cysteine) concentration. To assess the importance of cysteine, we determined in a double-blind study the effects of N-acetylcysteine on the functional capacity of frail geriatric patients and their response to physical exercise. The subjects on placebo showed only a relatively weak response, and 31% showed even a decrease in more than one parameter during the observation period. Low plasma arginine levels were correlated with a weak overall performance before exercise and a poor response to exercise. N-Acetylcysteine strongly enhanced the increase in knee extensor strength and significantly increased the sum of all strength parameters if adjusted for baseline arginine level as a confounding parameter. N-acetylcysteine had no significant effect on growth hormone and IGF-1 levels but caused a significant decrease in plasma TNF-alpha. These findings may provide a basis for therapeutic intervention and suggest that the loss of function involves limitations in cysteine and one or more other amino acids which may compromise muscular protein synthesis.

Somatotropina recombinante en la finalización de cerdos en dos condiciones climáticas

Brana VD, Angeles L, Loeza LR, Angeles MAA, Cuaron IJA. Tec Pecu Mex 2001,39(3)215-228. A total of 48 gilts and 48 barrows were used to measure the effects on productive performance, carcass characteristics and meat quality in pigs exposed to different environments (temperate or tropical). Pigs were treated or not with exogenous recombinant porcine Somatotropin (STp, 3 mg.pig- 1×d-1). Treatment, Location and Sex were considered as factors in a 23 factorial arrangement of a completely randomized design. Pigs initial weight was 53.8 ± 2.11 kg, and performance was followed upon an average body weight of 104.2 ± 1.7 kg. Somatotropin reduced feed intake by 6 % (2.95 vs STp, 2.77 kg.d-1, P<0.005), but improved growth rate (0.82 vs STp, 0.94 kg.d-1, P<0.001). Efficiency of feed utilization was greater for pigs in the temperate environment (temperate, 0.317 vs 0.299, P<0.004). Location and STp interacted for the yield of 5 primal cuts (P<0.02): The STp effect was greater under tropical conditions (+14 %) than under the temperate environment (+7 %). Fat free lean tissue was increased by STp (10 %, P<0.001). A higher environmental temperature (i.e., tropical) is an important limitation of the productive response. However, the STp effects (to a lesser extent than in tropical) were noticed. It is suggested that STp effects on energy utilization should be considered in the promotion of muscular protein synthesis. It was clear that STp is a useful tool to correct factors that prevent greater protein deposition or the efficiency of the process in finishing pigs.

Catabolic aspects of cranial trauma

During their stay in the intensive care unit, head-trauma patients develop a hypermetabolic and a hypercatabolic status. Their nitrogen balance is highly negative and the muscular proteolysis is largely increased. The nitrogen losses originate mainly in muscles, resulting in muscle wasting and weakness. The whole protein synthesis remains quite normal, but this does not reflect the reality, as muscular protein synthesis is decreased, while hepatic protein synthesis is increased. The increased proteolysis seems to be due to the activation of the three proteolytic pathways, particularly the ATP-ubiquitin-dependent pathway. The causes of the increased muscle proteolysis in head trauma patients remain unclear. The increased glucocorticoid release, which is integrated in the acute phase response to injury, could be one of them. Glutamin, vitamin or zinc supplementation has been proposed in head trauma patients. The use of glucocorticoid antagonists, recombinant growth hormone or anti-cytokines are our fields of research.

Effect of inhibitors of cyclooxygenase and androgens on muscular protein synthesis in vitro

Journal Article Effect of inhibitors of cyclooxygenase and androgens on muscular protein synthesis in vitro Get access M Komjati, M Komjati I. Medizinische Universitätsklinik, Abteilungfür Klinische Endokrinologie & Diabetologie, Wien Search for other works by this author on: Oxford Academic Google Scholar H Vierhapper, H Vierhapper I. Medizinische Universitätsklinik, Abteilungfür Klinische Endokrinologie & Diabetologie, Wien Search for other works by this author on: Oxford Academic Google Scholar W Waldhäusl W Waldhäusl I. Medizinische Universitätsklinik, Abteilungfür Klinische Endokrinologie & Diabetologie, Wien Search for other works by this author on: Oxford Academic Google Scholar Acta Endocrinologica (Norway), Volume 120, Issue 3_Supplement, Jun 1989, Pages S19–S20, https://doi.org/10.1530/acta.0.120S019 Published: 01 June 1989

Evaluation of Clinical and Biological Parameters in Marastic Kwashiorkor Children Treated by Parenteral Nutrition

Reduction of hospital stay and mortality rate due to dehydration and electrolyte imbalance in children suffering from severe marasmic Kwashiorkor was attempted. A program of parenteral nutrition providing 70 to 100 milliliters water, 30 to 40 kilocalories, and 3 to 4 grams amino acids per kilogram daily was given. Seventy-seven African children suffering from protein deficiency and calorie deficiency were given an intravenous perfusion of casein hydrolysate or cristalloid amino acids for a mean period of 6 days. An oral supplement of tea and sugar, boiled rice, and palm oil was also given. The total mortality has not been modified in comparison with that in children given an oral diet (semi-liquid) consisting of low fat milk and locally available proteins. In more than half of the cases, the parenteral nutrition has favored water and salt retention and the development of cardiac failure possibly due to adynamic circulatory state. Weight curve, serum albumins, serum and urine amino acids were followed closely for 1 month. In eleven patients, nitrogen balance studies were done. All were positive independently of the coexisting infectious pathology. Correlating the increase in serum proteins with the cumulative nitrogen balance allowed us to consider casein hydrolysate as particularly useful for hepatic protein synthesis while cristalloid amino acids seem to favor muscular protein synthesis. The introduction of parenteral nutrition as a therapeutic regimen for standard use in the malnourished child seems less favorable than oral realimentation programs and does not seem desirable in developing countries.

Neural control of gene expression in the skeletal muscle fibre: the nature of the lesion in the muscular protein-synthesizing machinery following denervation.

Experiments are reported showing that following 8 days of denervation the function of the protein-synthesizing machinery, operating in the rat gastrocnemius fibres, is altered, probably as a consequence of decreased amounts of ribosomes and actively translated mRNA. In addition, the data obtained show that the amount per muscle and the availability per ribosome of the soluble factors involved in the process of protein synthesis are markedly decreased, thus suggesting that the amounts of ribosomes, mRNA and soluble factors are regulated in a concerted fashion when muscular protein synthesis is decreased after denervation.