C2C12 Skeletal Muscle Cells Research Articles

6′-Sialyllactose Prevents Dexamethasone-Induced Muscle Atrophy by Controlling the Muscle Protein Degradation Pathway

Sarcopenia is associated with various geriatric diseases, such as gait disorders, falls, malnutrition, and osteoporosis. Accordingly, interest in the prevention and treatment of sarcopenia has grown over the years. The human milk oligosaccharide (HMO) 6′-sialyllactose (6′-SL) is known to improve exercise performance, reduce muscle fatigue, and improve GNE myopathy; however, its effect on sarcopenia has not yet been reported. In this study, we aimed to investigate the efficacy of 6′-SL in dexamethasone-induced muscle atrophy, which is a widely used model for the study of sarcopenia. The effects of 6′-SL on differentiated C2C12 skeletal muscle cells and on mice were examined by treatment with 6′-SL in the presence or absence of dexamethasone. 6′-SL was found to inhibit the dexamethasone-induced decrease of MHC expression, as well as to prevent reduction in the number, length, and width of myotubes. Furthermore, the dexamethasone-induced upregulation of myostatin, muscle RING-finger protein-1 (MuRF1), and atrogin-1 were also inhibited by 6′-SL treatment. In mice, intraperitoneal administration of dexamethasone caused decreases in muscle fiber diameter, muscle weight, and exercise performance, most of which were significantly inhibited by oral treatment with 6′-SL. Therefore, utilization of 6′-SL could contribute to the prevention and treatment of muscle atrophy and sarcopenia.

Therapeutic Potential of Rosa davurica Pall. Root Extract as an Antidiabetic Agent: A Comprehensive Analysis from Molecular Mechanisms to In Vivo Efficacy.

Rosa davurica Pall. is widely used in traditional oriental herbal therapy, but its components and molecular mechanisms of action remain unclear. This study investigates the antidiabetic potential of Rosa davurica Pall. root extract (RDR) and elucidates its underlying molecular mechanisms with in vitro and in vivo models. Data from the current study show that RDR exhibits strong antioxidant activity and glucose homeostasis regulatory effects. It significantly impacts glucose homeostasis in C2C12 skeletal muscle cells by inhibiting α-glucosidase activity. Further molecular mechanistic studies revealed that RDR promoted glucose uptake by phosphorylation of AMP-activated protein kinase (AMPK)/acetyl-CoA carboxylase (ACC), but not Phosphatidylinositol 3-kinase (PI 3-kinase)/Akt in C2C12 skeletal muscle cells. These actions increased the expression and translocation of glucose transporter type 4 (GLUT4) to the plasma membrane. In addition, RDR treatment in the STZ-induced diabetic rats remarkably improved the low body weight, polydipsia, polyphagia, hyperglycemia, and islet architecture and increased the insulin/glucose ratio. The liver (ALT and AST) and kidney marker enzyme (BUN and creatinine) levels were restored by RDR treatment as well. Phytochemical analysis identified eight major constituents in RDR, crucial for its antioxidant and antidiabetic activity. Through the molecular docking of representative glucose transporter GLUT4 with these compounds, it was confirmed that the components of RDR had a significantly high binding score in terms of structural binding. These findings from the current study highlight the antidiabetic effects of RDR. Collectively, our data suggest that RDR might be a potential pharmaceutical natural product for diabetic patients.

Activation of α7 Nicotinic Acetylcholine Receptor Improves Muscle Endurance by Upregulating Orosomucoid Expression and Glycogen Content in Mice.

There are presently no acknowledged therapeutic targets or official drugs for the treatment of muscle fatigue. The alpha7 nicotinic acetylcholine receptor (α7nAChR) is expressed in skeletal muscle, with an unknown role in muscle endurance. Here, we try to explore whether α7nAChR could act as a potential therapeutic target for the treatment of muscle fatigue. Results showed that nicotine and PNU-282987 (PNU), as nonspecific and specific agonists of α7nAChR, respectively, could both significantly increase C57BL6/J mice treadmill-running time in a time- and dose-dependent manner. The improvement effect of PNU on running time and ex vivo muscle fatigue index disappeared when α7nAChR deletion. RNA sequencing revealed that the differential mRNAs affected by PNU were enriched in glycolysis/gluconeogenesis signaling pathways. Further studies found that PNU treatment significantly elevates glycogen content and ATP level in the muscle tissues of α7nAChR+/+ mice but not α7nAChR-/- mice. α7nAChR activation specifically increased endogenous glycogen-targeting protein orosomucoid (ORM) expression both in vivo skeletal muscle tissues and in vitro C2C12 skeletal muscle cells. In ORM1 deficient mice, the positive effects of PNU on running time, glycogen and ATP content, as well as muscle fatigue index, were abolished. Therefore, the activation of α7nAChR could enhance muscle endurance via elevating endogenous anti-fatigue protein ORM and might act as a promising therapeutic strategy for the treatment of muscle fatigue.

Piceatannol Upregulates SIRT1 Expression in Skeletal Muscle Cells and in Human Whole Blood: In Vitro Assay and a Randomized, Double-Blind, Placebo-Controlled, Parallel-Group Comparison Trial.

Piceatannol (PIC), a polyphenol abundant in passion fruit seeds, is reported to promote fat metabolism. This study investigated whether PIC affects sirtuin 1 (SIRT1) expression and metabolic factors in C2C12 skeletal muscle cells. C2C12 myotubes were stimulated with PIC, and alterations in gene expression, protein levels, mitochondrial DNA content, and fatty acid levels were assessed using real-time PCR, Western blotting, and Nile red staining. Furthermore, we examined changes in SIRT1 expression following the consumption of a test food containing 100 mg PIC for 2 weeks among adults with varying age and body mass index ranges. Both PIC and passion fruit seed extract induced SIRT1 expression in C2C12 myotubes to a greater extent than resveratrol. PIC also increased the expression of genes associated with mitochondrial biogenesis and fatty acid utilization, increased mitochondrial DNA content, and suppressed oleic acid-induced fat accumulation. Moreover, participants who consumed PIC exhibited significantly higher SIRT1 mRNA expression in whole blood compared to those in the placebo group. These findings suggest that PIC induces SIRT1 expression both in vitro and in the human body, which may promote mitochondrial biosynthesis and fat metabolism.

Amber (Succinite) Extract Enhances Glucose Uptake through the Up-Regulation of ATP and Down-Regulation of ROS in Mouse C2C12 Cells.

Traditionally, amber (Succinite) has been used to alleviate all types of pain, skin allergies, and headaches. However, no studies have been conducted on its antidiabetic and antioxidant effects. In this study, differentiated skeletal muscle C2C12 cells were used to demonstrate the protective effects of amber (AMB) against H2O2-induced cell death. In addition, the effects of AMB on glucose uptake and ATP production were investigated. Our results showed that AMB at 10, 25, and 50 μg/mL suppressed the elevation of ROS production induced by H2O2 in a dose-dependent manner. Moreover, AMB enhanced glucose utilization in C2C12 cells through the improvement of ATP production and an increase in PGC-1α gene expression resulting in an amelioration of mitochondrial activity. On the other hand, AMB significantly increased the gene expression of glucose transporters GLUT4 and GLUT1. Our finding suggests that AMB can be used as a natural supplement for diabetes treatment and for the promotion of skeletal muscle function.

A method for growing and differentiating the C2C12 muscle cell line in the laboratory

Skeletal muscle-related studies have recently been applied in the combat of obesity and metabolic disorders. Culture skeletal muscle cells in in vitro plays an important role in being a promising model for those researches. In the present study, the C2C12 skeletal muscle cells were grown and differentiated in in vitro. The C2C12 myoblasts were grown in Dulbecco’s modified eagle’s medium (DMEM) containing 10% fetal bovine serum (FBS) for 4 – 5 days. The cells then reached confluent about 70% to 100% and the medium was shifted to DMEM plus 2% horse serum which leads the grown C2C12 cells becoming to differentiated myotubes. Myogenin mRNA levels were found to be significantly higher in the differentiated myotubes than those in the growing cells confirming the successful formation of the differentiated C2C12 cells. These results indicate that the C2C12 cell line is suitable for culture in in vitro to mimic a skeletal muscle microenvironment for further investigations.

Stevioside Ameliorates Palmitic Acid-Induced Abnormal Glucose Uptake via the PDK4/AMPK/TBC1D1 Pathway in C2C12 Myotubes.

Stevioside (SV) with minimal calories is widely used as a natural sweetener in beverages due to its high sweetness and safety. However, the effects of SV on glucose uptake and the pyruvate dehydrogenase kinase isoenzyme (PDK4) as an important protein in the regulation of glucose metabolism, remain largely unexplored. In this study, we used C2C12 skeletal muscle cells that was induced by palmitic acid (PA) to assess the effects and mechanisms of SV on glucose uptake and PDK4. The glucose uptake of C2C12 cells was determined by 2-NBDG; expression of the Pdk4 gene was measured by quantitative real-time PCR; and expression of the proteins PDK4, p-AMPK, TBC1D1 and GLUT4 was assessed by Western blotting. In PA-induced C2C12 myotubes, SV could significantly promote cellular glucose uptake by decreasing PDK4 levels and increasing p-AMPK and TBC1D1 levels. SV could promote the translocation of GLUT4 from the cytoplasm to the cell membrane in cells. Moreover, in Pdk4-overexpressing C2C12 myotubes, SV decreased the level of PDK4 and increased the levels of p-AMPK and TBC1D1. SV was found to ameliorate PA-induced abnormal glucose uptake via the PDK4/AMPK/TBC1D1 pathway in C2C12 myotubes. Although these results warranted further investigation for validation, they may provide some evidence of SV as a safe natural sweetener for its use in sugar-free beverages to prevent and control T2DM.

Biological Activities of Deer Antler-Derived Peptides on Human Chondrocyte and Bone Metabolism.

Orally administered "tortoiseshell and deer antler gelatin" is a common traditional medicine for patients with osteoporosis or osteoarthritis. From the pepsin-digested gelatin, we previously isolated and identified the osteoblast-stimulating pentapeptide, TSKYR. Its trypsin digestion products include the dipeptide YR, enhancing calcium ion uptake, and tripeptide TSK, resulting in remarkable 30- and 50-fold increases in mineralized nodule area and density in human osteoblast cells. These peptides were chemically synthesized in this study. The composition of deer antler preparations comprises not only proteins and peptides but also a significant quantity of metal ion salts. By analyzing osteoblast growth in the presence of peptide YR and various metal ions, we observed a synergistic effect of calcium and strontium on the effects of YR. Those peptides could also stimulate the growth of C2C12 skeletal muscle cells and human chondrocytes, increasing collagen and glycosaminoglycan content in a three-dimensional environment. The maintenance of bone homeostasis relies on a balance between osteoclasts and osteoblasts. Deer antler peptides were observed to inhibit osteoclast differentiation, as evidenced by ROS generation, tartrate-resistant acid phosphatase (TRACP) activity assays, and gene expression in RAW264.7 cells. In summary, our findings provide a deep understanding of the efficacy of this folk medicine.

Glycolipids Derived from the Korean Endemic Plant Aruncus aethusifolius Inducing Glucose Uptake in Mouse Skeletal Muscle C2C12 Cells.

Aruncus spp. has been used as a traditional folk medicine worldwide for its anti-inflammatory, hemostatic, and detoxifying properties. The well-known species A. dioicus var. kamtschaticus has long been used for multifunctional purposes in Eastern Asia. Recently, it was reported that its extract has antioxidant and anti-diabetic effects. In this respect, it is likely that other Aruncus spp. possess various biological activities; however, little research has been conducted thus far. The present study aims to biologically identify active compounds against diabetes in the Korean endemic plant A. aethusifolius and evaluate the underlying mechanisms. A. aethusifolius extract enhanced glucose uptake without toxicity to C2C12 cells. A bioassay-guided isolation of A. aethusifolius yielded two pure compounds, and their structures were characterized as glycolipid derivatives, gingerglycolipid A, and (2S)-3-linolenoylglycerol-O-β-d-galactopyranoside by an interpretation of nuclear magnetic resonance and high-resolution mass spectrometric data. Both compounds showed glucose uptake activity, and both compounds increased the phosphorylation levels of insulin receptor substrate 1 (IRS-1) and 5'-AMP-activated protein kinase (AMPK) and protein expression of peroxisome proliferator-activated receptor γ (PPARγ). Gingerglycolipid A docked computationally into the active site of IRS-1, AMPK1, AMPK2, and PPARγ (-5.8, -6.9, -6.8, and -6.8 kcal/mol).

A lipidomics approach reveals novel phospholipid changes in palmitate-treated C2C12 myotubes.

Type 2 diabetes mellitus (T2DM) is a highly prevalent metabolic disorder. Insulin resistance and oxidative stress are associated with T2DM development. The hypothesis that patients with T2DM show excess accumulation of lipids, such as ceramides (Cers) and diacylglycerols (DAGs), in their skeletal muscles has been widely supported; however, detailed lipidomic data at the molecular species level are limited. Therefore, in this study, we aimed to investigate the in vitro dynamics of total lipids, including phospholipids (PLs), sphingolipids, and neutral lipids, in palmitic acid-induced insulin-resistant C2C12 skeletal muscle cells. Our data demonstrated that the profiles of not only Cers and DAGs but also those of PLs showed considerably differences after palmitate treatment. We found that PL synthesis reduced and PL degradation increased after palmitate treatment. These findings may aid in the development of treatments to ameliorate muscle dysfunction caused by lipid accumulation in muscles.

The Effect and Mechanism of Fructus lycii on Improvement of Exercise Fatigue Using a Network Pharmacological Approach with in vitro Experimental Verification

ObjectiveThis study aimed to investigate the effect and underlying mechanism of Fructus lycii in improving exercise fatigue. MethodsA network pharmacological approach was used to explore potential mechanisms of action of Fructus lycii. Skeletal muscle C2C12 cells and immunofluorescence were employed to verify the effect and mechanism of the representative components in Fructus lycii predicted by network pharmacological analysis. ResultsSix potential active components, namely quercetin, β-sitosterol, stigmasterol, 7-Omethylluteolin-6-C-beta-glucoside_qt, atropine, and glycitein, were identified to have potency in improving exercise fatigue via multiple pathways, such as the PI3K-Akt, neuroactive ligand-receptor interaction, IL-17, TNF, and MAPK signaling pathways. The immunofluorescence results indicated that quercetin, a significant active component in Fructus lycii, increased the mean staining area of 2-NBDG, TMRM, and MitoTracker, and decreased the area of CellRox compared to the control. Furthermore, the protein expression levels of p-38 MAPK, p-MAPK, p-JNK, p-PI3K, and p-AKT markedly increased after quercetin treatment. ConclusionFructus lycii might alleviate exercise fatigue through multiple components and pathways. Among these, quercetin appears to improve exercise fatigue by enhancing energy metabolism and reducing oxidative stress. The PI3K-AKT and MAPK signaling pathways also appear to play a role in this process.

Comprehensive Assessment of Graphene Oxide Nanoparticles: Effects on Liver Enzymes and Cardiovascular System in Animal Models and Skeletal Muscle Cells.

The growing interest in graphene oxide (GO) for different biomedical applications requires thoroughly examining its safety. Therefore, there is an urgent need for reliable data on how GO nanoparticles affect healthy cells and organs. In the current work, we adopted a comprehensive approach to assess the influence of GO and its polyethylene glycol-modified form (GO-PEG) under near-infrared (NIR) exposure on several biological aspects. We evaluated the contractility of isolated frog hearts, the activity of two rat liver enzymes-mitochondrial ATPase and diamine oxidase (DAO), and the production of reactive oxygen species (ROS) in C2C12 skeletal muscle cells following direct exposure to GO nanoparticles. The aim was to study the influence of GO nanoparticles at multiple levels-organ; cellular; and subcellular-to provide a broader understanding of their effects. Our data demonstrated that GO and GO-PEG negatively affect heart contractility in frogs, inducing stronger arrhythmic contractions. They increased ROS production in C2C12 myoblasts, whose effects diminished after NIR irradiation. Both nanoparticles in the rat liver significantly stimulated DAO activity, with amplification of this effect after NIR irradiation. GO did not uncouple intact rat liver mitochondria but caused a concentration-dependent decline in ATPase activity in freeze/thaw mitochondria. This multifaceted investigation provides crucial insights into GOs potential for diverse implications in biological systems.

Microarchitected Compliant Scaffolds of Pyrolytic Carbon for 3D Muscle Cell Growth.

The integration of additive manufacturing technologies with the pyrolysis of polymeric precursors enables the design-controlled fabrication of architected 3D pyrolytic carbon (PyC) structures with complex architectural details. Despite great promise, their use in cellular interaction remains unexplored. This study pioneers the utilization of microarchitected 3D PyC structures as biocompatible scaffolds for the colonization of muscle cells in a 3D environment. PyC scaffolds are fabricated using micro-stereolithography, followed by pyrolysis. Furthermore, an innovative design strategy using revolute joints is employed to obtain novel, compliant structures of architected PyC. The pyrolysis process results in a pyrolysis temperature- and design-geometry-dependent shrinkage of up to 73%, enabling the geometrical features of microarchitected compatible with skeletal muscle cells. The stiffness of architected PyC varies with the pyrolysis temperature, with the highest value of 29.57±0.78GPa for 900°C. The PyC scaffolds exhibit excellent biocompatibility and yield 3D cell colonization while culturing skeletal muscle C2C12 cells. They further induce good actin fiber alignment along the compliant PyC construction. However, no conclusive myogenic differentiation is observed here. Nevertheless, these results are highly promising for architected PyC scaffolds as multifunctional tissue implants and encourage more investigations in employing compliant architected PyC structures for high-performance tissue engineeringapplications.

Increased expression of GLUT4, catalase and nitric oxide by a crystalised fraction from ethanolic extracts of oak leaf lettuce and okra seed in C2C12 cell line

The fractions obtained from low temperature-induced crystallisation of ethanolic extracts of green- and red-oak leaf and okra seed were accounted for total polyphenol content and the DPPH antioxidant activity, resulting in 5.99, 4.44, and 12.35 mg gallic acid equivalent per g sample, and 0.45, 0.35, and 0.99 mg Trolox equivalent per g sample, respectively. Insulin resistance was the result after incubating C2C12 skeletal muscle cells in high glucose DMEM for 20 h. Oxidative stress and inflammation were triggered by re-incubating these resistant cells with insulin. The expression of p-p38 MAPK and NF-B proteins and the NF-B p65 transcription factor activity were enhanced. Such inflammatory protein markers were reduced when the crystalised extracts replaced insulin. Increased catalase activity and NO production were also determined for the incubations using the crystalised extracts. It was suitable to include these vegetables in the daily diets of prediabetic individuals for better management of the patient’s health status by increasing insulin sensitivity and decreasing inflammation.

L-VALINE TREATMENT IMPROVES CELLULAR MITOCHONDRIAL FUNCTION

Abstract Branched-chain amino acids (BCAAs) are pivotal for the health of the human body. Leucine, isoleucine, and valine, which make up the BCAAs, are α-amino acids that promote skeletal muscle growth and development. Valine is one of the essential BCAAs required for the synthesis of muscle proteins and the support growth of skeletal muscles. Valine also plays a favorable role in enhancing insulin sensitivity, preserving intestinal health, and optimizing lipid metabolism. Considering the relevance of valine in promoting muscle growth and metabolism, we utilized C2C12 skeletal muscle cell line to investigate the role of valine in regulating mitochondrial functions. C2C12 cells grown on physiological normal glucose media (100mg/dL) were used for the experiments. Cells were treated with a 1.0 mM concentration of valine for 24 h. The effect of valine treatment on gene expression of important mitochondrial-related genes such as PGC-1α, and PGC-1β and mitofusin (MFN1, MFN), and mitochondrial fission 1 (Fis 1) was determined. Further, Oroboros oxygraph-O2K high-resolution respirometer was used to analyze the mitochondrial respiration in the intact C2C12 cells after valine treatment. The results showed increased gene expression of PGC-1α, PGC-1β, and mitochondrial fission and fusin genes after treatment with valine. The basal respiration, leak respiration, as well as maximal capacity of mitochondrial ETC (Electron Transport Chain), were also significantly improved after valine treatment. The findings from this study enhance our understanding of valine as an important nutrient to improve mitochondrial function to drive cellular function and biological processes.

Danshensu Attenuates Apoptosis and Ferroptosis in Hypoxia Induced C2C12 Skeletal Muscle Cell Injury

Exercise-induced muscle damage can be caused by excessive or unfamiliar eccentric exercises. Hypoxia induces oxidative stress in C2C12 myoblasts, mimicking intracellular muscle injury. Under hypoxic conditions, the accumulation of reactive oxygen species causes cell death through apoptosis and ferroptosis. Identifying candidate natural products involved in oxidative stress and developing strategies to mitigate these effects have garnered significant attention. In the present study, we used Danshensu as a candidate product to determine its protective effects against hypoxia-induced C2C12 cell damage via apoptosis and ferroptosis. The results showed that Danshensu restored cell death and apoptosis by regulating B-cell lymphoma 2 protein, its associated X Protein and cleaved-caspase 3. Additionally, Danshensu restored ferroptosis by regulating glutathione peroxidase 4 and solute carrier family 7 member 11 protein under hypoxic conditions. Moreover, the accumulation of reactive oxygen species caused by hypoxia was attenuated in the presence of Danshensu. These findings provide new insights into the potential of Danshensu as an alternative treatment for hypoxia-induced damage to the skeletal muscle C2C12 cell line.

Effect of Uncaria tomentosa aqueous extract on the response to palmitate-induced lipotoxicity in cultured skeletal muscle cells

BackgroundType 2 diabetes mellitus (T2DM) is frequently associated with dyslipidemia, which corresponds to the increase in the triglycerides and fatty acid concentrations in tissues, such as the skeletal muscle. Also, T2DM molecular mechanism involves increasing in reactive oxygen species (ROS) production and oxidative stress. The use of herbal medicines such as Uncaria tomentosa (Ut) has been proposed as an auxiliary treatment for patients with T2DM. In this study, it was evaluated the effect of Ut aqueous extract on cell viability and ROS production, in skeletal myoblasts from C2C12 lineage exposed to the free fatty acid palmitate (PA).MethodsCells were incubated with PA in different concentrations ranging from 10 to 1000 μM, for 24 or 48 h, for cytotoxicity assay. Cell death, DNA fragmentation and ROS production assays were performed in cell cultures incubated with PA for 24 h, in the pre (preventive condition) or post treatment (therapeutic condition) with 250 μg/ml Ut aqueous extract, for 2 or 6 h. Cell death was evaluated by MTT method or flow cytometry. ROS generation was measured by fluorescence spectroscopy using the DCFDA probe.ResultsCell viability was reduced to approximately 44% after the incubation with PA for 24 h from the concentration of 500 µM. In the incubation of cells with 500 μM PA and Ut extract for 6 h, in both conditions (preventive or therapeutic), it was observed an increase of 27 and 70% in cell viability respectively, in comparison to the cultures incubated with only PA. Also, the incubation of cultures with 500 μM PA, for 24 h, increased 20-fold the ROS formation, while the treatment with Ut extract, for 6 h, both in the preventive or therapeutic conditions, promoted decrease of 21 and 55%, respectively.ConclusionThe Ut extract was efficient in promoting cell protection against PA lipotoxicity and ROS generation, potentially preventing oxidative stress in C2C12 skeletal muscle cells. Since T2DM molecular mechanism involves oxidative stress condition and it is often associated with dyslipidemia and fatty acid accumulation in muscle tissue, these results open perspectives for the use of Ut as an auxiliary strategy for T2DM management.

Skeletal muscle cells opto-stimulation by intramembrane molecular transducers

Optical stimulation and control of muscle cell contraction opens up a number of interesting applications in hybrid robotic and medicine. Here we show that recently designed molecular phototransducer can be used to stimulate C2C12 skeletal muscle cells, properly grown to exhibit collective behaviour. C2C12 is a skeletal muscle cell line that does not require animal sacrifice Furthermore, it is an ideal cell model for evaluating the phototransducer pacing ability due to its negligible spontaneous activity. We study the stimulation process and analyse the distribution of responses in multinuclear cells, in particular looking at the consistency between stimulus and contraction. Contractions are detected by using an imaging software for object recognition. We find a deterministic response to light stimuli, yet with a certain distribution of erratic behaviour that is quantified and correlated to light intensity or stimulation frequency. Finally, we compare our optical stimulation with electrical stimulation showing advantages of the optical approach, like the reduced cell stress.

Advanced glycation end products inhibit proliferation and primary cilia formation of myoblasts through receptor for advanced glycation end products pathway

The loss of skeletal muscle mass leads to various adverse conditions and shortened lifespan. The inhibition of myoblast proliferation is one of the causes that trigger muscle atrophy. Advanced glycation end products (AGEs) contribute to muscle atrophy. Since primary cilia are crucial organelles for proliferation, AGEs may inhibit primary cilia formation of myoblasts, thereby leading to impaired proliferation. Therefore, we aimed to clarify whether AGEs impeded the proliferation and formation of primary cilia of C2C12 skeletal muscle cells. AGE treatment inhibited the proliferation and formation of primary cilia. However, the inhibitor of the receptor for advanced glycosylation end products (RAGEs) abolished the inhibition of the proliferation and the primary cilia formation of C2C12 cells by AGEs, suggesting that AGEs cause these inhibitions through the RAGE pathway. In summary, our findings suggested that AGEs suppress the proliferation and formation of primary cilia of myoblasts through the RAGE pathway.

SAT128 Low Concentration Of Butyrate Reverts PA-induced Atrophic Condition On C2C12 Myotubes

Abstract Disclosure: S. Tini: None. A. Antonioli: None. S. Reano: None. T. Raiteri: None. A. Scircoli: None. V. Antoniotti: None. I. Zaggia: None. N. Filigheddu: None. F. Prodam: None. Sarcobesity is a well-defined medical condition characterized by the coexistence between skeletal muscle atrophy and increased fat mass representing, nowadays, a relevant public health issue among the world population. Sarcobesity is often associated with the development of metabolic syndrome (MetS), insulin-resistance (IR), dyslipidaemia, and other pathologies such as cardiovascular diseases (CVDs) and type 2 diabetes (T2DM). The global increment of this condition has been favoured by changes in lifestyle and dietary habits as largely demonstrated. Particularly, Western Diet (WD), rich in saturated fats and sugars and poor in fibers, vitamins, and minerals seems to be the main cause of sarcobesity in association with low levels of physical activity. In recent years, Ketogenic Diet (KD) has been proposed as a fighting obesity therapy and as a new possible therapeutic strategy to counteract the WD detrimental effects on different tissues, i.e skeletal muscle that plays a key role in whole-body metabolism, glucose homeostasis and lipid use. KD regimen consists in a very low carbohydrates intake, high fat and adequate protein contents that cause the so-called “nutritional ketosis” with the production of Ketone bodies (KBs). KBs, such as beta-hydroxybutyrate (BHB), acetoacetate and acetone are the final products of the partial beta-oxidation of free fatty acid. They are short chain fatty acid produced in liver with different role on metabolism and they are used as a source of energy instead of glucose by different tissues including skeletal muscle. Preliminary experiments in our laboratory demonstrated that palmitate (PA), which is a saturated fat highly present in WD regimen, induces myotubes atrophy in dose dependent manner (100, 250, 500uM). The aim of the present study is to investigate not only if KBs have a direct effect on C2C12 skeletal muscle cells, but also if they are able to contrast the PA-induced atrophy in myotubes. We demonstrated with a co-treatment that sodium butyrate (s-BU), which is the main KB produced during ketogenesis, is able to prevent PA negative effects in skeletal muscle cells when it is used at low concentration. In contrast, high doses of BU reduced C2C12 diameters suggesting that KBs could have opposite effects depending on their concentration. Currently, other short chain fatty acids and KBs, i.e pyruvate and acetoacetate are under investigation in our laboratory. Collectively, these data suggest that KD could represent a promising intervention to contrast WD damages on skeletal muscle in overweight/obese individuals. Presentation: Saturday, June 17, 2023