scholarly journals Proteome dynamics during homeostatic scaling in cultured neurons

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Aline Ricarda Dörrbaum ◽  
Beatriz Alvarez-Castelao ◽  
Belquis Nassim-Assir ◽  
Julian D Langer ◽  
Erin M Schuman
Keyword(s):  
Protein Synthesis ◽  
Protein Function ◽  
Protein Turnover ◽  
Experimental Approach ◽  
Large Fraction ◽  
Synaptic Proteins ◽  
Turnover Rates ◽  
Cellular Environment ◽  
Protein Synthesis And Degradation ◽  
Synthesis And Degradation

Protein turnover, the net result of protein synthesis and degradation, enables cells to remodel their proteomes in response to internal and external cues. Previously, we analyzed protein turnover rates in cultured brain cells under basal neuronal activity and found that protein turnover is influenced by subcellular localization, protein function, complex association, cell type of origin, and by the cellular environment (Dörrbaum et al., 2018). Here, we advanced our experimental approach to quantify changes in protein synthesis and degradation, as well as the resulting changes in protein turnover or abundance in rat primary hippocampal cultures during homeostatic scaling. Our data demonstrate that a large fraction of the neuronal proteome shows changes in protein synthesis and/or degradation during homeostatic up- and down-scaling. More than half of the quantified synaptic proteins were regulated, including pre- as well as postsynaptic proteins with diverse molecular functions.

scholarly journals Serum extracellular vesicle miR-203a-3p content is associated with skeletal muscle mass and protein turnover during disuse atrophy and regrowth

2020 ◽  
Vol 319 (2) ◽  
pp. C419-C431
Author(s):  
Douglas W. Van Pelt ◽  
Ivan J. Vechetti ◽  
Marcus M. Lawrence ◽  
Kathryn L. Van Pelt ◽  
Parth Patel ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Muscle Mass ◽  
Muscle Atrophy ◽  
Protein Turnover ◽  
Muscle Protein ◽  
Weight Bearing ◽  
Mirna Content ◽  
Protein Synthesis And Degradation ◽  
Synthesis And Degradation

Small noncoding microRNAs (miRNAs) are important regulators of skeletal muscle size, and circulating miRNAs within extracellular vesicles (EVs) may contribute to atrophy and its associated systemic effects. The purpose of this study was to understand how muscle atrophy and regrowth alter in vivo serum EV miRNA content. We also associated changes in serum EV miRNA with protein synthesis, protein degradation, and miRNA within muscle, kidney, and liver. We subjected adult (10 mo) F344/BN rats to three conditions: weight bearing (WB), hindlimb suspension (HS) for 7 days to induce muscle atrophy, and HS for 7 days followed by 7 days of reloading (HSR). Microarray analysis of EV miRNA content showed that the overall changes in serum EV miRNA were predicted to target major anabolic, catabolic, and mechanosensitive pathways. MiR-203a-3p was the only miRNA demonstrating substantial differences in HS EVs compared with WB. There was a limited association of EV miRNA content to the corresponding miRNA content within the muscle, kidney, or liver. Stepwise linear regression demonstrated that EV miR-203a-3p was correlated with muscle mass and muscle protein synthesis and degradation across all conditions. Finally, EV miR-203a-3p expression was significantly decreased in human subjects who underwent unilateral lower limb suspension (ULLS) to induce muscle atrophy. Altogether, we show that serum EV miR-203a-3p expression is related to skeletal muscle protein turnover and atrophy. We suggest that serum EV miR-203a-3p content may be a useful biomarker and future work should investigate whether serum EV miR-203a-3p content is mechanistically linked to protein synthesis and degradation.

Skeletal and cardiac muscle protein turnover during short-term cold exposure and rewarming in young rats

1996 ◽  
Vol 270 (6) ◽  
pp. R1231-R1239 ◽  
Author(s):  
S. E. Samuels ◽  
J. R. Thompson ◽  
R. J. Christopherson
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Cardiac Muscle ◽  
Cold Exposure ◽  
Growth Rates ◽  
Protein Turnover ◽  
Short Term ◽  
Ad Libitum ◽  
Protein Synthesis And Degradation ◽  
Synthesis And Degradation

Young animals exposed to cold environmental temperatures typically have decreased skeletal muscle accretion but increased heart masses. To explore these phenomena, we measured protein synthesis and degradation in vivo in cardiac and skeletal muscle in weanling rats during short-term cold exposure and rewarming. Control rats were housed at 25 degrees C throughout the experiment. Ad libitum-fed and pair-fed (to the intake of controls) rats were housed at 5 degrees C (cold) for 5 days and then at 25 degrees C (rewarmed) for another 5 days. Cold exposure decreased rates of protein accretion and synthesis in skeletal muscle, whereas degradation did not differ. The effects of cold exposure on skeletal muscle were similar in both pair-fed and ad libitum-fed rats, except growth was lower in pair-fed rats. In cardiac muscle, cold exposure increased rates of protein synthesis and degradation and resulted in increased cardiac mass. Results in pair-fed animals generally fell between those of control and ad libitum-fed cold rats. During rewarming, growth rates were not higher in skeletal muscle in ad libitum-fed re-warmed rats, although protein turnover returned toward control values; in pair-fed rats, it remained lower. In heart, growth rates of ad libitum-fed and pair-fed rewarmed rats decreased due to lower protein synthesis rates. These alterations appear to be consistent with a strategy designed to improve survival in cold environments.

Effects of chronic sublethal ammonia and a simulated summer global warming scenario: protein synthesis in juvenile rainbow trout (Oncorhynchus mykiss)

1998 ◽  
Vol 55 (6) ◽  
pp. 1534-1544 ◽  
Author(s):  
Scott D Reid ◽  
T K Linton ◽  
J J Dockray ◽  
D G McDonald ◽  
C M Wood
Keyword(s):  
Protein Synthesis ◽  
Global Warming ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Protein Turnover ◽  
Warming Scenario ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Global Warming Scenario ◽  
Protein Synthesis And Degradation ◽  
Synthesis And Degradation

Protein synthesis, net accretion, and degradation in liver, gill, and white muscle and ribosomal translational efficiency and protein synthesis capacity in liver and gill were measured using a flooding dose of [3H]phenylalanine in juvenile rainbow trout (Oncorhynchus mykiss). The fish were chronically exposed (90 days) in hardwater to the presence or absence of sublethal ammonia (70 µmol total ammonia ·L-1) alone or in combination with a 2°C elevation in the normal temperature profile over the months of June-September 1993 (ambient temperature range 13-22°C). Chronic sublethal exposure to ammonia had little impact on gill protein synthesis and degradation (protein turnover) and even less in muscle. However, in the liver, both protein synthesis and degradation were stimulated following 60 days of the sublethal ammonia exposure. The 2°C elevation in temperature resulted in a slight increase in protein turnover in both gills and liver. However, during the period of peak water temperature, the 2°C elevation in temperature inhibited protein dynamics in these tissues. Overall, elevated environmental ammonia in combination with a summer global warming scenario would challenge the ability of fish to adapt to alterations in the quality of their environment, most notably during periods of peak temperatures.

scholarly journals Response of muscle protein turnover to insulin after acute exercise and training

1986 ◽  
Vol 240 (3) ◽  
pp. 651-657 ◽  
Author(s):  
T A Davis ◽  
I E Karl
Keyword(s):  
Protein Synthesis ◽  
Exercise Training ◽  
Protein Turnover ◽  
Acute Exercise ◽  
Muscle Protein ◽  
Muscle Protein Turnover ◽  
Exercise And Training ◽  
Protein Synthesis And Degradation ◽  
Synthesis And Degradation

To determine whether the enhanced insulin-sensitivity of glucose metabolism in muscle after acute exercise also extends to protein metabolism, untrained and exercise-trained rats were subjected to an acute bout of exercise, and the responses of protein synthesis and degradation to insulin were measured in epitrochlearis muscles in vitro. Acute exercise of both untrained and trained rats decreased protein synthesis in muscle in the absence or presence of insulin, but protein degradation was not altered. Exercise training alone had no effect on protein synthesis or degradation in muscle in the absence or presence of insulin. Acute exercise or training alone enhanced the sensitivities of both protein synthesis and degradation to insulin, but the enhanced insulin-sensitivities from training alone were not additive to those after acute exercise. These results indicate that: a decrease in protein synthesis is the primary change in muscle protein turnover after acute exercise and is not altered by prior exercise training, and the enhanced insulin-sensitivities of metabolism of both glucose and protein after either acute exercise or training suggest post-binding receptor events.

scholarly journals PROTEIN TURNOVER DURING MATURATION OF MOUSE BRAIN TISSUE

1972 ◽  
Vol 53 (1) ◽  
pp. 143-147 ◽  
Author(s):  
Brian E. Gilbert ◽  
Terry C. Johnson
Keyword(s):  
Protein Synthesis ◽  
Protein Turnover ◽  
Dynamic Balance ◽  
Brain Cell ◽  
Brain Cells ◽  
Cyclic Phenomenon ◽  
New Protein ◽  
Protein Synthesis And Degradation ◽  
Synthesis And Degradation ◽  
Newborn Animals

The measurement of protein turnover involves the product of the rates of protein synthesis and degradation. It is the dynamic balance between these two components that determines the measured net rate of protein synthesis. The data reported here show that brain cells from newborn animals incorporate arginine-14C into acid-insoluble protein at a rate 10-fold greater than the rate for brain cells obtained from 15-day old animals. This difference in incorporation occurred even though the rate of arginine accumulation and the resulting pool size of radioactive precursor were similar for both ages. The measurement of protein turnover in brain cell suspensions prepared from 1-day old animals was shown to be complex and to exhibit a cyclic phenomenon in regard to arginine-14C incorporation into and release from protein. The variation in half-life calculations (0.5–3.5 hr) due to this cyclic phenomenon is discussed. Although puromycin was added in an attempt to amplify the rate of degradation by preventing the synthesis of new protein, it was found that degradation was inhibited as well, suggesting a relationship between protein synthesis and degradation.

scholarly journals A comparison of rates of protein turnover in rat diaphragm in vivo and in vitro

1986 ◽  
Vol 233 (1) ◽  
pp. 279-282 ◽  
Author(s):  
V R Preedy ◽  
D M Smith ◽  
P H Sugden
Keyword(s):  
Protein Synthesis ◽  
Protein Turnover ◽  
Rat Diaphragm ◽  
Degradation Rates ◽  
Protein Synthesis And Degradation ◽  
Synthesis And Degradation

Protein synthesis and degradation rates in diaphragms from fed or starved rats were compared in vivo and in vitro. For fed rats, synthesis rates in vivo were approximately twice those in vitro, but for starved rats rates were similar. Degradation rates were less in vivo than in vitro in diaphragms from either fed or starved rats.

Protein turnover in different types of skeletal muscle during experimental hyperthyroidism in rats

1985 ◽  
Vol 109 (1) ◽  
pp. 90-95 ◽  
Author(s):  
Ulf Angerås ◽  
Per-Olof Hasseigren
Keyword(s):  
Protein Synthesis ◽  
Protein Content ◽  
Protein Turnover ◽  
Extensor Digitorum Longus ◽  
Muscle Protein ◽  
Slow Muscle ◽  
Protein Breakdown ◽  
Different Types ◽  
Protein Synthesis And Degradation ◽  
Synthesis And Degradation

Abstract. Exeprimental hyperthyroidism was induced in rats by daily ip injection of triiodothyronine (T3; 100 μg/100 g body weight) during 3 or 10 days. Protein synthesis and degradation were measured in incubated soleus and extensor digitorum longus (EDL) muscles by determining rate of tyrosine incorporation into protein and release of tyrosine to the incubation medium respectively. Protein synthesis was unaffected by T3 administration during 3 or 10 days. Protein breakdown was significantly increased in soleus but unchanged in EDL in the 3-days experiment. Following administration of T3 for 10 days proteolysis was increased in both muslces. Weight of the soleus muscle was reduced after T3 for 3 days. After 10 days weight and protein content were reduced in both muscles. The study demonstrated that reduced muscle protein content following administration of T3 was the result of increased proteolysis, not decreased protein synthesis. The results further indicate that slow muscle (soleus) is more sensitive to the effects of thyroid hormone than fast muscle (EDL).

scholarly journals Slowed Protein Turnover in Aging Drosophila Reflects a Shift in Cellular Priorities

2021 ◽  
Author(s):  
Evelyn S Vincow ◽  
Ruth E Thomas ◽  
Gennifer E Merrihew ◽  
Michael J MacCoss ◽  
Leo J Pallanck
Keyword(s):  
Quality Control ◽  
Protein Turnover ◽  
Protein Quality ◽  
Fruit Fly ◽  
Turnover Rates ◽  
High Turnover ◽  
Age Related ◽  
System Collapse ◽  
Protein Synthesis And Degradation ◽  
Synthesis And Degradation

Abstract The accumulation of protein aggregates and dysfunctional organelles as organisms age has led to the hypothesis that aging involves general breakdown of protein quality control. We tested this hypothesis using a proteomic and informatic approach in the fruit fly Drosophila melanogaster. Turnover of most proteins was markedly slower in old flies. However, ribosomal and proteasomal proteins maintained high turnover rates, suggesting that the observed slowdowns in protein turnover might not be due to a global failure of quality control. As protein turnover reflects the balance of protein synthesis and degradation, we investigated whether decreases in synthesis or decreases in degradation would best explain the observed slowdowns in protein turnover. We found that while many individual proteins in old flies showed slower turnover due to decreased degradation, an approximately equal number showed slower turnover due to decreased synthesis, and enrichment analyses revealed that translation machinery itself was less abundant. Mitochondrial complex I subunits and glycolytic enzymes were decreased in abundance as well, and proteins involved in glutamine-dependent anaplerosis were increased, suggesting that old flies modify energy production to limit oxidative damage. Together, our findings suggest that age-related proteostasis changes in Drosophila represent a coordinated adaptation rather than a system collapse.

P0915PROTEIN ENERGY WASTING IS ASSOCIATED WITH A DECLINE IN MUSCLE PROTEIN SYNTHESIS IN CKD PATIENTS

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Michela Saio ◽  
Antonella Sofia ◽  
Rodolfo Russo ◽  
Leda Cipriani ◽  
Giacomo Garibotto ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Protein Metabolism ◽  
Protein Turnover ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Stage Iv ◽  
Kinetic Studies ◽  
Ckd Stage ◽  
Protein Synthesis And Degradation ◽  
Synthesis And Degradation

Abstract Background and Aims Skeletal muscle is a highly adaptive tissue, however even small imbalances between protein synthesis and degradation can lead to substantial protein loss. Althought proteolysis plays a major role in the development of cachexia in CKD (chronic kidney disease), the responses of muscle protein metabolism to malnutrition had not been completely elucidated. We evaluated retrospectively the results of kinetic studies of protein turnover estimated by the forearm perfusion method associated with H2phenylalanine kinetic, obtained in CKD patients and controls in the last 25 years. Method We analyzed 59 forearm H2phenylalanine kinetic studies obtained in 14 controls (C) (M 11, F 3) and 45 patients with CKD, of whom 15 (M 10, F 5) were on conservative treatment (CKD stage IV-V), 16 (M 14, F 2) under maintenance hemodialysis (HD), 14 (M 12, F 2) in peritoneal dialysis (DP); all subjects were on non-restricted protein/calorie (0.8-1.1 g/kg and 28-32 kcal/kg, respectively) diets. Ten (M 9, F 1) HD patients had Protein Energy Wasting. Acidosis was corrected in all patients (HCO3 24.2±1.9 mmol/L) and studies were performed in the post-absorptive overnight fasted state at rest. Results Overall, Muscle protein synthesis and degradation were similar (p=NS) in patients and controls. Protein net balance was reduced in patients with PD and those with CKD Stage IV-V (p <0.003 - p <0.014) indicating a reduced catabolic state and nitrogen conservation. However PEW HD patients showed reduced rates of protein synthesis and degradation (p <0.048 and p <0.04 respectively). In addition the efficiency of muscle protein turnover, a parameter expressing muscle's ability to reuse amino acids derived from degradation into protein synthesis, was significantly reduced in HD PEW patients vs. controls (55.5 vs. 61.2 %, p <0.018, respectively) and vs. not malnourished patients in conservative treatment (70.1 % p <0.0025) or in PD (74.6 % p <0.005). Conclusion In CKD patients, in absence of acidosis, muscle is able to increase the efficiency of protein metabolism for the maintenance of nitrogen balance. However, in PEW patients, combined alterations of protein synthesis and degradation proceed together to a reduced efficiency of amino acids recycled into protein synthesis and contribute to maintaining wasting. These data also suggest that calorie/protein requirements of CKD patients with PEW may be higher than currently theorized.

Abnormalities in protein synthesis and degradation induced by extracellular pH in BC3H1 myocytes

1991 ◽  
Vol 260 (2) ◽  
pp. C277-C282 ◽  
Author(s):  
B. K. England ◽  
J. L. Chastain ◽  
W. E. Mitch
Keyword(s):  
Protein Synthesis ◽  
Protein Turnover ◽  
Acid Metabolism ◽  
Cellular Protein ◽  
Extracellular Acidification ◽  
Physiological Concentration ◽  
Bicarbonate Buffer ◽  
Ethanesulfonic Acid ◽  
Protein Synthesis And Degradation ◽  
Synthesis And Degradation

Metabolic acidosis impairs protein and amino acid metabolism in rat muscle. To examine how extracellular acidification affects cellular protein turnover, we studied the BC3H1 myocyte. At pH 7.1 vs. 7.4, intracellular pH was lower; the decrease was greater in cells incubated in N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid-tris(hydroxymethyl)aminomethane compared with bicarbonate buffer. We monitored degradation of proteins labeled with L-[14C]phenylalanine by measuring radioactivity released into media containing an excess of unlabeled phenylalanine. Extracellular acidification increased degradation compared with incubation at pH 7.4. Adding a physiological concentration of insulin (1 nM) decreased protein degradation at pH 7.1 and 7.4; a supraphysiological (71 nM) insulin concentration decreased degradation at pH 7.1 to the same rate as cells incubated at pH 7.4 without insulin. Compared with pH 7.4, protein synthesis decreased 29% at pH 7.2; at pH 7.6 it increased 129%. Insulin stimulated protein synthesis at all pHs, but at pH 7.4 the insulin-induced increase was less than the rate at pH 7.6 without insulin. Dexamethasone did not change protein breakdown regardless of the pH; it had variable effects on protein synthesis. Thus extracellular acidification causes marked changes in protein turnover in BC3H1 myocytes.

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