scholarly journals A Fish-Derived Protein Hydrolysate Induces Postprandial Aminoacidaemia and Skeletal Muscle Anabolism in an In Vitro Cell Model Using Ex Vivo Human Serum

Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 647
Author(s):  
Matthew J. Lees ◽  
David Nolan ◽  
Miryam Amigo-Benavent ◽  
Conor J. Raleigh ◽  
Neda Khatib ◽  
...  
Keyword(s):  
Older Adults ◽  
Skeletal Muscle ◽  
Human Serum ◽  
Body Mass ◽  
Ex Vivo ◽  
Protein Hydrolysate ◽  
C2c12 Myotubes ◽  
The Impact

Fish-derived proteins, particularly fish protein hydrolysates (FPH), offer potential as high-quality sources of dietary protein, whilst enhancing economic and environmental sustainability. This study investigated the impact of a blue whiting-derived protein hydrolysate (BWPH) on aminoacidaemia in vivo and skeletal muscle anabolism in vitro compared with whey protein isolate (WPI) and an isonitrogenous, non-essential amino acid (NEAA) control (0.33 g·kg−1·body mass−1) in an ex vivo, in vitro experimental design. Blood was obtained from seven healthy older adults (two males, five females; age: 72 ± 5 years, body mass index: 24.9 ± 1.6 kg·m2) in three separate trials in a randomised, counterbalanced, double-blind design. C2C12 myotubes were treated with ex vivo human serum-conditioned media (20%) for 4 h. Anabolic signalling (phosphorylation of mTOR, p70S6K, and 4E-BP1) and puromycin incorporation were determined by immunoblotting. Although BWPH and WPI both induced postprandial essential aminoacidaemia in older adults above the NEAA control, peak and area under the curve (AUC) leucine and essential amino acids were more pronounced following WPI ingestion. Insulin was elevated above baseline in WPI and BWPH only, a finding reinforced by higher peak and AUC values compared with NEAA. Muscle protein synthesis, as measured by puromycin incorporation, was greater after incubation with WPI-fed serum compared with fasted serum (P = 0.042), and delta change was greater in WPI (P = 0.028) and BWPH (P = 0.030) compared with NEAA. Myotube hypertrophy was greater in WPI and BWPH compared with NEAA (both P = 0.045), but was similar between bioactive conditions (P = 0.853). Taken together, these preliminary findings demonstrate the anabolic potential of BWPH in vivo and ex vivo, thus providing justification for larger studies in older adults using gold-standard measures of acute and chronic MPS in vivo.

scholarly journals A cell-based evaluation of a non-essential amino acid formulation as a non-bioactive control for activation and stimulation of muscle protein synthesis using ex vivo human serum

2019 ◽  
Author(s):  
Bijal Patel ◽  
Martina Pauk ◽  
Miryam Amigo-Benavent ◽  
Alice B. Nongonierma ◽  
Richard J. Fitzgerald ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Western Blot ◽  
Human Serum ◽  
Ex Vivo ◽  
Muscle Protein ◽  
Muscle Cells ◽  
Skeletal Muscle Cells ◽  
Effective Control ◽  
C2c12 Myotubes

AbstractPurposeThe purpose of this study was to compare the effect of treating skeletal muscle cells with media conditioned by postprandial ex vivo human serum fed with either isonitrogenous NEAA or a whey protein hydrolysate (WPH) on stimulating MPS in C2C12 skeletal muscle cells.MethodsBlood was taken from six young healthy males following overnight fast (fasted) and 60 min postprandial (fed) ingestion of either WPH or NEAA (0.33 g.kg-1 Body Mass). C2C12 myotubes were treated with media conditioned by ex vivo human serum (20%) for 4 h. Activation of MPS signalling (phosphorylation of mTOR, P70S6K and 4E-BP1) were determined in vitro by Western Blot and subsequent de novo MPS were determined in vitro by Western Blot and surface sensing of translation technique (SUnSET) techniques, respectively.ResultsMedia conditioned by NEAA fed serum had no effect on protein signalling or MPS compared to fasted, whereas media conditioned by WPH fed serum significantly increased mTOR, P70S6K and 4E-BP1 phosphorylation (p<0.01, p<0.05) compared to fasted serum. Furthermore, the effect of media conditioned by WPH fed serum on protein signalling and MPS was significantly increased (p<0.01, p<0.05) compared to NEAA fed serum.ConclusionIn summary, media conditioned by NEAA fed serum did not result in activation of MPS. Therefore, these in vitro findings suggest the use of isonitrogenous NEAA acts as an effective control for comparing bioactivity of different proteins on activation of MPS. These findings also confirm that activation of MPS in C2C12 myotubes treated with media conditioned by WPH-fed serum is primarily due to circulating EAA.

scholarly journals Intestinal IgA Regulates Expression of a Fructan Polysaccharide Utilization Locus in Colonizing Gut Commensal Bacteroides thetaiotaomicron

mBio ◽  
2019 ◽  
Vol 10 (6) ◽  
Author(s):  
Payal Joglekar ◽  
Hua Ding ◽  
Pablo Canales-Herrerias ◽  
Pankaj Jay Pasricha ◽  
Justin L. Sonnenburg ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Ex Vivo ◽  
Microbial Colonization ◽  
Bacteroides Thetaiotaomicron ◽  
Content Type ◽  
Microbial Utilization ◽  
Polysaccharide Utilization Locus ◽  
The Impact

ABSTRACT Gut-derived immunoglobulin A (IgA) is the most abundant antibody secreted in the gut that shapes gut microbiota composition and functionality. However, most of the microbial antigens targeted by gut IgA remain unknown, and the functional effects of IgA targeting these antigens are currently understudied. This study provides a framework for identifying and characterizing gut microbiota antigens targeted by gut IgA. We developed a small intestinal ex vivo culture assay to harvest lamina propria IgA from gnotobiotic mice, with the aim of identifying antigenic targets in a model human gut commensal, Bacteroides thetaiotaomicron VPI-5482. Colonization by B. thetaiotaomicron induced a microbe-specific IgA response that was reactive against diverse antigens, including capsular polysaccharides, lipopolysaccharides, and proteins. IgA against microbial protein antigens targeted membrane and secreted proteins with diverse functionalities, including an IgA specific against proteins of the polysaccharide utilization locus (PUL) that are necessary for utilization of fructan, which is an important dietary polysaccharide. Further analyses demonstrated that the presence of dietary fructan increased the production of fructan PUL-specific IgA, which then downregulated the expression of fructan PUL in B. thetaiotaomicron, both in vivo and in vitro. Since the expression of fructan PUL has been associated with the ability of B. thetaiotaomicron to colonize the gut in the presence of dietary fructans, our work suggests a novel role for gut IgA in regulating microbial colonization by modulating their metabolism. IMPORTANCE Given the significant impact that gut microbes have on our health, it is essential to identify key host and environmental factors that shape this diverse community. While many studies have highlighted the impact of diet on gut microbiota, little is known about how the host regulates this critical diet-microbiota interaction. In our present study, we discovered that gut IgA targeted a protein complex involved in the utilization of an important dietary polysaccharide: fructan. While the presence of dietary fructans was previously thought to allow unrestricted growth of fructan-utilizing bacteria, our work shows that gut IgA, by targeting proteins responsible for fructan utilization, provides the host with tools that can restrict the microbial utilization of such polysaccharides, thereby controlling their growth.

scholarly journals Image-based modelling of skeletal muscle oxygenation

2017 ◽  
Vol 14 (127) ◽  
pp. 20160992 ◽  
Author(s):  
B. Zeller-Plumhoff ◽  
T. Roose ◽  
G. F. Clough ◽  
P. Schneider
Keyword(s):  
Skeletal Muscle ◽  
Blood Vessel ◽  
Ex Vivo ◽  
Imaging Techniques ◽  
Muscle Oxygenation ◽  
Skeletal Muscle Oxygenation ◽  
Health And Disease ◽  
Vessel Networks

The supply of oxygen in sufficient quantity is vital for the correct functioning of all organs in the human body, in particular for skeletal muscle during exercise. Disease is often associated with both an inhibition of the microvascular supply capability and is thought to relate to changes in the structure of blood vessel networks. Different methods exist to investigate the influence of the microvascular structure on tissue oxygenation, varying over a range of application areas, i.e. biological in vivo and in vitro experiments, imaging and mathematical modelling. Ideally, all of these methods should be combined within the same framework in order to fully understand the processes involved. This review discusses the mathematical models of skeletal muscle oxygenation currently available that are based upon images taken of the muscle microvasculature in vivo and ex vivo . Imaging systems suitable for capturing the blood vessel networks are discussed and respective contrasting methods presented. The review further informs the association between anatomical characteristics in health and disease. With this review we give the reader a tool to understand and establish the workflow of developing an image-based model of skeletal muscle oxygenation. Finally, we give an outlook for improvements needed for measurements and imaging techniques to adequately investigate the microvascular capability for oxygen exchange.

scholarly journals EZH2 inhibition reduces cartilage loss and functional impairment related to osteoarthritis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Lyess Allas ◽  
Sybille Brochard ◽  
Quitterie Rochoux ◽  
Jules Ribet ◽  
Cleo Dujarrier ◽  
...  
Keyword(s):  
Functional Disability ◽  
Ex Vivo ◽  
Cartilage Degradation ◽  
Motor Functions ◽  
Methyl Transferase ◽  
Expression Of Genes ◽  
Medial Meniscectomy ◽  
The Impact

Abstract Histone methyltransferase EZH2 is upregulated during osteoarthritis (OA), which is the most widespread rheumatic disease worldwide, and a leading cause of disability. This study aimed to assess the impact of EZH2 inhibition on cartilage degradation, inflammation and functional disability. In vitro, gain and loss of EZH2 function were performed in human articular OA chondrocytes stimulated with IL-1β. In vivo, the effects of EZH2 inhibition were investigated on medial meniscectomy (MMX) OA mouse model. The tissue alterations were assayed by histology and the functional disabilities of the mice by actimetry and running wheel. In vitro, EZH2 overexpression exacerbated the action of IL-1β in chondrocytes increasing the expression of genes involved in inflammation, pain (NO, PGE2, IL6, NGF) and catabolism (MMPs), whereas EZH2 inhibition by a pharmacological inhibitor, EPZ-6438, reduced IL-1β effects. Ex vivo, EZH2 inhibition decreased IL-1β-induced degradation of cartilage. In vivo, intra-articular injections of the EZH2 inhibitor reduced cartilage degradation and improved motor functions of OA mice. This study demonstrates that the pharmacological inhibition of the histone methyl-transferase EZH2 slows the progression of osteoarthritis and improves motor functions in an experimental OA model, suggesting that EZH2 could be an effective target for the treatment of OA by reducing catabolism, inflammation and pain.

Effects of aging on cardiac and skeletal muscle AMPK activity: basal activity, allosteric activation, and response to in vivo hypoxemia in mice

2004 ◽  
Vol 287 (5) ◽  
pp. R1270-R1275 ◽  
Author(s):  
Asensio A. Gonzalez ◽  
Reetu Kumar ◽  
Jacob D. Mulligan ◽  
Ashley J. Davis ◽  
Kurt W. Saupe
Keyword(s):  
Skeletal Muscle ◽  
Ex Vivo ◽  
Allosteric Activation ◽  
Biochemical Basis ◽  
Hypoxic Tolerance ◽  
Ampk Activity ◽  
Effects Of Aging ◽  
Amp Activated Protein Kinase

Although a diminished ability of tissues and organisms to tolerate stress is a clinically important hallmark of normal aging, little is known regarding its biochemical basis. Our goal was to determine whether age-associated changes in AMP-activated protein kinase (AMPK), a key regulator of cellular metabolism during the stress response, might contribute to the poor stress tolerance of aged cardiac and skeletal muscle. Basal AMPK activity and the degree of activation of AMPK by AMP and by in vivo hypoxemia (arterial Po2 of 39 mmHg) were measured in cardiac and skeletal muscle (gastrocnemius) from 5- and 24-mo-old C57Bl/6 mice. In the heart, neither basal AMPK activity nor its allosteric activation by AMP was affected by age. However, after 10 min of hypoxemia, the activity of α2-AMPK, but not α1-AMPK, was significantly higher in the hearts from old than from young mice ( P < 0.005), this difference being due to differences in phosphorylation of α2-AMPK. Significant activation of AMPK in the young hearts did not occur until 30 min of hypoxemia ( P < 0.01), stress that was poorly tolerated by the old mice (mortality = 67%). In contrast, AMPK activity in gastrocnemius muscle was unaffected by age or hypoxemia. We conclude that the age-associated decline in hypoxic tolerance in cardiac and skeletal muscle is not caused by changes in basal AMPK activity or a blunted AMPK response to hypoxia. Activation of AMPK by in vivo hypoxia is slower and more modest than might be predicted from in vitro and ex vivo experiments.

scholarly journals MR imaging of model drug distribution in simulated vitreous

2015 ◽  
Vol 1 (1) ◽  
pp. 236-239 ◽  
Author(s):  
Sandra Stein ◽  
Christian Simroth-Loch ◽  
Sönke Langner ◽  
Stefan Hadlich ◽  
Oliver Stachs ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Ex Vivo ◽  
Drug Distribution ◽  
Injection Technique ◽  
Innovative Therapy ◽  
Age Related ◽  
The Impact

AbstractThe in vitro and in vivo characterization of intravitreal injections plays an important role in developing innovative therapy approaches. Using the established vitreous model (VM) and eye movement system (EyeMoS) the distribution of contrast agents with different molecular weight was studied in vitro. The impact of the simulated age-related vitreal liquefaction (VL) on drug distribution in VM was examined either with injection through the gel phase or through the liquid phase. For comparison the distribution was studied ex vivo in the porcine vitreous. The studies were performed in a magnetic resonance (MR) scanner. As expected, with increasing molecular weight the diffusion velocity and the visual distribution of the injected substances decreased. Similar drug distribution was observed in VM and in porcine eye. VL causes enhanced convective flow and faster distribution in VM. Confirming the importance of the injection technique in progress of VL, injection through gelatinous phase caused faster distribution into peripheral regions of the VM than following injection through liquefied phase. VM and MR scanner in combination present a new approach for the in vitro characterization of drug release and distribution of intravitreal dosage forms.

scholarly journals PL - 033 A translational model of muscle protein synthetic bioactivity in vitro, ex vivo and in vivo

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Brian Carson ◽  
Robert Davies ◽  
Joseph Bass ◽  
Catherine Norton ◽  
Bijal Patel ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Stable Isotope ◽  
Resistance Exercise ◽  
Ex Vivo ◽  
Muscle Protein ◽  
Muscle Growth ◽  
Translational Model ◽  
Nutrient Feeding

Objective The aim of this research was the development and validation of a translational model for the evaluation of exercise and nutrient stimulated muscle protein synthesis (MPS). To achieve this overall aim, three primary objectives had to be realised: (i) Development of an in vitro skeletal muscle cell bioassay to measure muscle growth and MPS; (ii) Development of an ex vivo model to evaluate the humoral effect on MPS in response to nutrient feeding and exercise; (iii) Use of a stable isotope technique to evaluate MPS in response to nutrient feeding and exercise in vivo. Methods To develop a novel in vitro skeletal muscle cell bioassay to measure muscle growth and MPS, C2C12 myoblasts were proliferated and subsequently differentiated to myotubes over 8 days in DMEM (2% HS). Changes in cell behavior and adhesion properties were monitored by measuring impedance via interdigitated microelectrodes using the xCELLigence system. MPS was measured by puromycin incorporation using the SUnSET technique, intracellular signalling measured by western blot, and myotube thickness by microscopy. To demonstrate the capability to monitor nutrient regulation of muscle growth, media was conditioned with a known potent regulator of MPS (leucine) in a dose response experiment (0.20 - 2.0 mM). To establish the ability of the bioassay to measure the humoral effect of MPS in response to feeding and exercise, media was conditioned by ex vivo human serum from fasted, rested, fed (protein and isonitrogenous non-essential amino acid (NEAA) control)  and post-exercise conditions. To evaluate MPS in response to nutrient feeding and exercise in vivo, acute MPS (5 h) was assessed by measuring stable isotope deuterium oxide (D2O) incorporation into m. vastus lateralis skeletal muscle following consumption of either a Whey Protein (WP) or an isonitrogenous NEAA control combined with resistance exercise in resistance trained males. Results In vitro experiments observed a dose-response effect with a 32 % increase in cell index and a 27 % increase in cell thickness after 2 h in the presence of 2.0 mM leucine when compared with control myotubes. Ex vivo serum following ingestion of NEAA had no effect on protein signalling or MPS whereas WP fed serum significantly increased mTOR, P70S6K and 4E-BP1 phosphorylation (p<0.01, p<0.05) compared to fasted serum. Furthermore, the effect of WP fed serum on protein signalling and MPS was significantly increased (p<0.01, p<0.05) compared to NEAA fed serum.  Ex vivo human serum following resistance exercise was also increased MPS (29 %) and phosphorylation of mTOR (6 %), p70S6K (12 %) and 4EBP1 (7 %), compared with resting serum. These ex vivo/in vitro findings translated to the in vivo model as myofibrillar fractional synthetic rates (myoFSR) (Basal 0.068±0.002%h-1 vs. WP 0.084±0.006 %h-1, p=0.033) and absolute synthetic rates (ASR) (Basal 10.34±1.01 vs. WP 13.18±0.71 g.day-1, p=0.026) were increased from basal levels only when resistance exercise was combined with WP ingestion and not the NEAA control (NEAA MPS 0.072±0.004%h-1, NEAA ASR 10.23±0.80 g.day-1).  Thus, ingestion of WP in combination with resistance training augments acute MPS responses in resistance trained young men. Conclusions We have developed a translational model of muscle protein synthetic bioactivity using in vitro, ex vivo and in vivo methodologies. We have shown that we can impact MPS in vitro using ex vivo human serum to condition media, that MPS in vitro is differentially regulated by ex vivo serum containing bioactive WP compared to a non-bioactive NEAA control, and that this tranlates for resistance exercise combined with WP in humans when MyoFSR is measured using stable isotope technology.  These experiments demonstrate that ex vivo/in vitro experiments translate to the in vivo model and these methods can be used to inform both exercise and nutrient human interventions. 

scholarly journals Hyperthermia increases interleukin-6 in mouse skeletal muscle

2012 ◽  
Vol 303 (4) ◽  
pp. C455-C466 ◽  
Author(s):  
Steven S. Welc ◽  
Neil A. Phillips ◽  
Jose Oca-Cossio ◽  
Shannon M. Wallet ◽  
Daniel L. Chen ◽  
...  
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Core Temperature ◽  
Ex Vivo ◽  
C2c12 Myotubes ◽  
Tnf Α ◽  
Passive Hyperthermia ◽  
Circulating Levels ◽  
Cell Supernatant

Skeletal muscles produce and contribute to circulating levels of IL-6 during exercise. However, when core temperature is reduced, the response is attenuated. Therefore, we hypothesized that hyperthermia may be an important and independent stimulus for muscle IL-6. In cultured C2C12 myotubes, hyperthermia (42°C) increased IL-6 gene expression 14-fold after 1 h and 35-fold after 5 h of 37°C recovery; whereas exposure to 41°C resulted in a 2.6-fold elevation at 1 h. IL-6 protein was secreted and significantly elevated in the cell supernatant. Similar but reduced responses to heat were seen in C2C12 myoblasts. Isolated soleus muscles from mice, exposed ex vivo to 41°C for 1 h, yielded similar IL-6 gene responses (>3-fold) but without a significant effect on protein release. When whole animals were exposed to passive hyperthermia, such that core temperature increased to 42.4°C, IL-6 mRNA in soleus increased 5.4-fold compared with time matched controls. Interestingly, TNF-α gene expression was routinely suppressed at all levels of hyperthermia (40.5–42°C) in the isolated models, but TNF-α was elevated (4.2-fold) in the soleus taken from intact mice exposed, in vivo, to hyperthermia. Muscle HSP72 mRNA increased as a function of the level of hyperthermia, and IL-6 mRNA responses increased proportionally with HSP72. In cultured C2C12 myotubes, when heat shock factor was pharmacologically blocked with KNK437, both HSP72 and IL-6 mRNA elevations, induced by heat, were suppressed. These findings implicate skeletal muscle as a “heat stress sensor” at physiologically relevant hyperthermia, responding with a programmed cytokine expression pattern characterized by elevated IL-6.

Trastuzumab versus MYL-1401O (a proposed trastuzumab biosimilar) in a phase I bioequivalence study: In vivo and in vitro immunomodulation.

2017 ◽  
Vol 35 (7_suppl) ◽  
pp. 10-10
Author(s):  
Régine Audran ◽  
Haithem Chtioui ◽  
Anne-Christine Thierry ◽  
Carole Mayor ◽  
Laure Vallotton ◽  
...  
Keyword(s):  
Phase I ◽  
Mononuclear Cell ◽  
Ex Vivo ◽  
Reference Drug ◽  
Gm Csf ◽  
Significant Difference ◽  
Ifn Γ ◽  
The Impact

10 Background: Trastuzumab is a humanized monoclonal antibody targeting breast cancer cells overexpressing the HER2-oncoprotein. During a Phase-I single centre, single dose, randomized, double-blind, cross-over study assessing the bioequivalence of a proposed trastuzumab biosimilar (MYL-1401O) versus the initially marketed drug (Herceptin), we investigated in addition a large panel of pharmacodynamics parameters comparing the immunomodulatory activity of both drugs. Methods: 22 healthy males were included, 19 subjects receiving randomly a single intravenous infusion of MYL-1401O and 22 of Herceptin, separated by 16 to 22 week wash-out. Blood samples drawn pre- and post- infusion were assessed for in vivo serum cytokines induction (IL-1β, IL-2, IL-6, IL-10, IL-12, TNF-α, GM-CSF and IFN-γ) whereas the impact of treatment on mononuclear cell subsets and their level of activation was tested ex vivo. Volunteers’ PBMC (peripheral blood monocnuclear cells) were stimulated in vitro with recall antigens and mitogen for cytokine production. At baseline, we performed in addition a cytokine release assay on PBMC upon stimulation with trastuzumab as a preclinical safety test. Results: Trastuzumab infusion induced a transient and weak peak of serum IL-6 at 6h, and a modulation of mononuclear cell subset profile and level of activation. Notably CD16+ cells frequency decreased at 3h and peaked at 48h. Except for CD8+ T cells, there were no significant differences between Herceptin and its proposed biosimilar ex vivo. PBMC stimulated in vitro with trastuzumab secreted IL-6, TNF-a, IL-1β, GM-CSF, IFN-γ, and IL-10, but no IL-2. There was no significant difference between the two mAbs. Conclusions: Based on these in vivo, ex vivo and in vitro experiments, there is a strong assumption that MYL-1401O is biosimilar to the reference drug Herceptin for its immunomodulation properties as already proven for its bioequivalence. Clinical trial information: 2011-001406-94.

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