scholarly journals Dietary n-3 vs n-6 PUFA Differentially Modulate Macrophage-Myocyte Inflammatory Cross-Talk

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1644-1644
Author(s):  
Amber Hutchinson ◽  
Danyelle Liddle ◽  
Rufaida Ansari ◽  
Lindsay Robinson
Keyword(s):  
Skeletal Muscle ◽  
Soybean Oil ◽  
Mrna Expression ◽  
Inflammatory Cytokines ◽  
Cross Talk ◽  
Whole Body ◽  
High Fat ◽  
M1 Macrophage ◽  
Tnf Α ◽  
L6 Myocytes

Abstract Objectives Skeletal muscle is the primary site for insulin-stimulated glucose uptake. In obesity, increased circulating inflammatory cytokines interfere with skeletal muscle insulin signaling, leading to local and whole-body insulin resistance (IR). Moreover, obese skeletal muscle is characterized by accumulation of infiltrated M1 macrophages and ensuing macrophage-myocyte paracrine interactions (cross-talk) contribute to local inflammation and IR. Such macrophage-myocyte inflammatory cross-talk provides a potential intervention target for anti-inflammatory nutrients, including dietary long-chain n-3 polyunsaturated fatty acids (PUFA). Methods Using a co-culture model designed to mimic the degree of CD11b+ cell accumulation in obese skeletal muscle (40% of immune cells), differentiated L6 myocytes were co-cultured with purified splenic CD11b+ cells from male Sprague Dawley rats (7-wk old) consuming one of three isocaloric diets: i) high-fat (HF; 54% kcal lard, 6% kcal soybean oil), ii) high-fat with n-3 PUFA (HFn-3; 39% kcal lard + 15% kcal menhaden oil + 6% kcal soybean oil) or iii) high-fat with n-6 PUFA (HFn-6; 45% kcal lard + 15% kcal soybean oil) for 2, 8 or 12-wk (n = 8–12/diet). Co-cultures were stimulated for 24 h with lipopolysaccharide (LPS, 10 ng/mL) to mimic in vivo obese endotoxin levels. CD11b+ cells were also cultured alone for 24 h in conditioned media collected from L6 myocytes stimulated with LPS for 24 h (LCM). Results In co-cultures, HFn-6 increased mRNA expression of inflammatory markers compared to HF and HFn-3 at 8- (iNos; P ≤ 0.05) and 12-wk (Tnf-α, Il-6, Il-1β; P ≤ 0.05). Similarly, at 8-wk CD11b+ cells from HFn-6 rats that were treated with LCM, had increased mRNA expression of inflammatory cytokines (Tnf-α, Il-1β) and M1 polarization markers (iNos, Cd86) compared to both HF and HFn-3, and the same effects were seen with Il-6 and Il-1β at 12-wk (P ≤ 0.05). Lastly, HFn-3 reduced mRNA expression of Tnf-α compared to HF at 12-wk (P ≤ 0.05). Conclusions Together, these data suggest that n-6 PUFA support macrophage-myocyte inflammatory cross-talk, in part by promoting M1 macrophage polarization. Further, these data provide mechanistic insight into the benefits of n-3 vs n-6 PUFA inclusion in a high-fat diet in mitigating skeletal muscle inflammation in obesity. Funding Sources Natural Sciences and Engineering Research Council (NSERC) of Canada.

Anemic Hypoxemia Reduces Myoblast Proliferation and Muscle Growth in Late Gestation Fetal Sheep

2021 ◽  
Author(s):  
Paul J. Rozance ◽  
Stephanie R Wesolowski ◽  
Sonnet S. Jonker ◽  
Laura D Brown
Keyword(s):  
Skeletal Muscle ◽  
Mrna Expression ◽  
Muscle Growth ◽  
Late Gestation ◽  
Whole Body ◽  
Myoblast Differentiation ◽  
Fetal Sheep ◽  
Body Protein ◽  
Skeletal Muscle Growth ◽  
Myoblast Proliferation

Fetal skeletal muscle growth requires myoblast proliferation, differentiation, and fusion into myofibers in addition to protein accretion for fiber hypertrophy. Oxygen is an important regulator of this process. Therefore, we hypothesized that fetal anemic hypoxemia would inhibit skeletal muscle growth. Studies were performed in late gestation fetal sheep that were bled to anemic, and therefore hypoxemic, conditions beginning at ~125 days of gestation (term = 148 days) for 9 ± 0 days (n=19) and compared to control fetuses (n=16). A metabolic study was performed on gestational day ~134 to measure fetal protein kinetic rates. Myoblast proliferation and myofiber area were determined in biceps femoris (BF), tibialis anterior (TA), and flexor digitorum superficialis (FDS) muscles. mRNA expression of muscle regulatory factors was determined in BF. Fetal arterial hematocrit and oxygen content were 28% and 52% lower, respectively, in anemic fetuses. Fetal weight and whole-body protein synthesis, breakdown, and accretion rates were not different between groups. Hindlimb length, however, was 7% shorter in anemic fetuses. TA and FDS muscles weighed less and FDS myofiber area was smaller in anemic fetuses compared to controls. The percentage of Pax7+ myoblasts that expressed Ki67 was lower in BF and tended to be lower in FDS from anemic fetuses indicating reduced myoblast proliferation. There was less MYOD and MYF6 mRNA expression in anemic vs. control BF consistent with reduced myoblast differentiation. These results indicate that fetal anemic hypoxemia reduced muscle growth. We speculate that fetal muscle growth may be improved by strategies that increase oxygen availability.

scholarly journals Hormone therapy attenuates exercise-induced skeletal muscle damage in postmenopausal women

2009 ◽  
Vol 107 (3) ◽  
pp. 853-858 ◽  
Author(s):  
Christina M. Dieli-Conwright ◽  
Tanya M. Spektor ◽  
Judd C. Rice ◽  
E. Todd Schroeder
Keyword(s):  
Skeletal Muscle ◽  
Hormone Therapy ◽  
Mrna Expression ◽  
Postmenopausal Women ◽  
Muscle Damage ◽  
Exercise Bout ◽  
Control Group ◽  
Skeletal Muscle Damage ◽  
Tnf Α ◽  
Exercise Induced

Hormone therapy (HT) is a potential treatment to relieve symptoms of menopause and prevent the onset of disease such as osteoporosis in postmenopausal women. We evaluated changes in markers of exercise-induced skeletal muscle damage and inflammation [serum creatine kinase (CK), serum lactate dehydrogenase (LDH), and skeletal muscle mRNA expression of IL-6, IL-8, IL-15, and TNF-α] in postmenopausal women after a high-intensity resistance exercise bout. Fourteen postmenopausal women were divided into two groups: women not using HT (control; n = 6, 59 ± 4 yr, 63 ± 17 kg) and women using traditional HT (HT; n = 8, 59 ± 4 yr, 89 ± 24 kg). Both groups performed 10 sets of 10 maximal eccentric repetitions of single-leg extension on the Cybex dynamometer at 60°/s with 20-s rest periods between sets. Muscle biopsies of the vastus lateralis were obtained from the exercised leg at baseline and 4 h after the exercise bout. Gene expression was determined by RT-PCR for IL-6, IL-8, IL-15, and TNF-α. Blood draws were performed at baseline and 3 days after exercise to measure CK and LDH. Independent t-tests were performed to test group differences (control vs. HT). A probability level of P ≤ 0.05 was used to determine statistical significance. We observed significantly greater changes in mRNA expression of IL-6, IL-8, IL-15, and TNF-α ( P ≤ 0.01) in the control group compared with the HT group after the exercise bout. CK and LDH levels were significantly greater after exercise ( P ≤ 0.01) in the control group. Postmenopausal women not using HT experienced greater muscle damage after maximal eccentric exercise, indicating a possible protective effect of HT against exercise-induced skeletal muscle damage.

Lipopolysaccharide regulates proinflammatory cytokine expression in mouse myoblasts and skeletal muscle

2002 ◽  
Vol 283 (3) ◽  
pp. R698-R709 ◽  
Author(s):  
Robert A. Frost ◽  
Gerald J. Nystrom ◽  
Charles H. Lang
Keyword(s):  
Skeletal Muscle ◽  
Cell Wall ◽  
Mrna Expression ◽  
Nuclear Factor Κb ◽  
Cytokine Expression ◽  
Mrna Accumulation ◽  
C2c12 Myoblasts ◽  
Tnf Α ◽  
Mrna Content

The purpose of the present study was to examine the regulation of tumor necrosis factor (TNF)-α and interleukin (IL)-6 by lipopolysaccharide (LPS) in C2C12 myoblasts and mouse skeletal muscle. LPS produced dose- and time-dependent increases in TNF-α and IL-6 mRNA content in C2C12 myoblasts. The LPS-induced cytokine response could be mimicked by peptidoglycan from the cell wall of Staphylococcus aureus but not by zymosan A, a cell wall component from Saccharomyces cerevisiae. Ongoing protein synthesis was not necessary for the increase in the two cytokine mRNAs. The transcriptional inhibitor 5,6-dichloro-β-d-ribofuranosyl-benzimidazole blocked LPS-stimulated IL-6 mRNA expression without changing its mRNA half-life. The anti-inflammatory glucocorticoid dexamethasone selectively blocked LPS-stimulated IL-6 mRNA accumulation but not TNF-α. In contrast, the proteasomal inhibitor MG-132 blocked TNF-α mRNA expression but not IL-6. Exposure of myoblasts to LPS was associated with a rapid decrease in the inhibitor of nuclear factor-κB (I κB, α, and ε), and this response was also blocked by MG-132. Treatment of myocytes with IL-1 or TNF-α also increased IL-6 mRNA content, but the increase in IL-6 mRNA due to LPS could not be prevented by pretreatment with antagonists to either IL-1 or TNF. Under in vivo conditions, LPS increased the plasma concentration of TNF-α and IL-6 and stimulated the accumulation of their mRNAs in multiple tissues including skeletal muscle from wild-type mice. In contrast, the ability of LPS to stimulate the same cytokines was markedly decreased in mice that harbor a mutation in the Toll-like receptor 4. Our data suggest that LPS stimulates cytokine expression not only in classical immune tissues but also in skeletal muscle.

scholarly journals Analysis of the physical activity effects and measurement of pro-inflammatory cytokines in irradiated lungs in rats

2012 ◽  
Vol 27 (3) ◽  
pp. 223-230 ◽  
Author(s):  
Renata Cristiane Gennari Bianchi ◽  
Eduardo Rochete Ropelle ◽  
Carlos Kiyoshi Katashima ◽  
José Barreto Campello Carvalheira ◽  
Luiz Roberto Lopes ◽  
...  
Keyword(s):  
Physical Activity ◽  
Western Blotting ◽  
Inflammatory Cytokines ◽  
Lower Lobe ◽  
Whole Body ◽  
Control Group ◽  
Western Blotting Analysis ◽  
Blotting Analysis ◽  
Tnf Α ◽  
Pro Inflammatory Cytokines

PURPOSE: To study if the pre-radiotherapy physical activity has radio-protective elements, by measuring the radio-induced activation of pro-inflammatory cytokines as interleukin-6 (il-6), transforming growth factor -β (tgf -β), tumor necrosis factor -α (tnf-α) and protein beta kinase β (ikkβ), through western blotting analysis. METHODS: A randomized study with 28 Wistar hannover rats, males, with a mean age of 90 days and weighing about 200 grams. The animals were divided into three groups: (GI, GII and GIII). GIII group were submitted to swimming for eight weeks (zero load, three times a week, about 30 minutes). Then, the groups (except the control group) were submitted to irradiation by cobalt therapy, single dose of 3.5 gray in the whole body. All animals were sacrificed by overdose of pentobarbital, according to the time for analysis of cytokines, and then a fragment of the lower lobe of the right lung went to western blotting analysis. RESULTS: The cytokines IKK β, TNF-α and IL-6 induced by radiation in the lung were lower in the exercised animals. However, exercise did not alter the radiation-induced increase in tgf-β. CONCLUSION: The results show a lower response in relation to inflammatory cytokines in the group that practiced the exercise pre-radiotherapy, showing that exercise can protect tissues from tissue damage due to irradiation.

scholarly journals Chlorogenic Acid and Geniposide Combination Prevents NASH in Rats Fed High-fat diet via Microbiota and TLR4-LPS Pathway

2021 ◽  
Author(s):  
Zhijia Zhou ◽  
Lingxia Xu ◽  
Shaoliang Zhang ◽  
Shilin Xu ◽  
Yanmiao Yang ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Chlorogenic Acid ◽  
Inflammatory Cytokines ◽  
High Fat Diet ◽  
Oral Treatment ◽  
Variable Region ◽  
High Fat ◽  
Tnf Α ◽  
Abundance And Diversity ◽  
Factor Α

Abstract Objective: Chlorogenic acid and geniposide (CG) are derived from traditional Chinese medicine, Yinchenhao Recipe (QCHR), and can improve the clinical efficacy of NASH patients. This study investigated the effects of CG on NASH and expounded its Potential mechanism of action through the LPS-TLR4 pathway and microbiota. Methods: Rats were randomized into Control (C), Model (M), Chlorogenic Acid and Geniposide (CG), Pioglitazone (PH) and Bifico (B) groups. After an 8-week high-fat diet (HFD), CG, PH and B oral treatment were initiated and carried out for a further 8 weeks. The stool samples were used in a16S rDNA V4 highly variable region measurement method in order to regulate the role of CG in gut microbiota. The concentrations of triglyceride (TG), cholesterol (CHO), interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) in LPS were detected by the corresponding methods. Results: Observations were made that CG significantly improved the pathology of the liver and terminal ileum tissue. The accumulation of TG and the content of inflammatory cytokines in the liver were significantly decreased and the abundance of Proteobacteria was significantly down-regulated. The expression of TLR4, AP-1, MyD88, and phosphorylated NF-κB p65 were significantly decreased. All the findings above indicated that CG was highly effective in improving the composition of gut microbiota, decreasing the production of endogenous LPS, and reducing the secretion of inflammatory cytokines through the gut-liver axis.Conclusion: CG can regulate the abundance and diversity of the intestinal microbial community and improve liver inflammation and steatosis in NASH rats by reducing LPS-TLR4-mediated inflammation.

Prevention of skeletal muscle insulin resistance by dietary cod protein in high fat-fed rats

2001 ◽  
Vol 281 (1) ◽  
pp. E62-E71 ◽  
Author(s):  
Charles Lavigne ◽  
Frédéric Tremblay ◽  
Geneviève Asselin ◽  
Hélène Jacques ◽  
André Marette
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Amino Acids ◽  
Glucose Uptake ◽  
Soy Protein ◽  
Whole Body ◽  
Glucose Disposal ◽  
High Fat ◽  
Muscle Insulin Resistance ◽  
Skeletal Muscle Insulin Resistance

In the present study, we tested the hypothesis that fish protein may represent a key constituent of fish with glucoregulatory activity. Three groups of rats were fed a high-fat diet in which the protein source was casein, fish (cod) protein, or soy protein; these groups were compared with a group of chow-fed controls. High-fat feeding led to severe whole body and skeletal muscle insulin resistance in casein- or soy protein-fed rats, as assessed by the euglycemic clamp technique coupled with measurements of 2-deoxy-d-[3H]glucose uptake rates by individual tissues. However, feeding cod protein fully prevented the development of insulin resistance in high fat-fed rats. These animals exhibited higher rates of insulin-mediated muscle glucose disposal that were comparable to those of chow-fed rats. The beneficial effects of cod protein occurred without any reductions in body weight gain, adipose tissue accretion, or expression of tumor necrosis factor-α in fat and muscle. Moreover, L6 myocytes exposed to cod protein-derived amino acids showed greater rates of insulin-stimulated glucose uptake compared with cells incubated with casein- or soy protein-derived amino acids. These data demonstrate that feeding cod protein prevents obesity-induced muscle insulin resistance in high fat-fed obese rats at least in part through a direct action of amino acids on insulin-stimulated glucose uptake in skeletal muscle cells.

scholarly journals Leptin administration improves skeletal muscle insulin responsiveness in diet-induced insulin-resistant rats

2001 ◽  
Vol 280 (1) ◽  
pp. E130-E142 ◽  
Author(s):  
Ben B. Yaspelkis ◽  
James R. Davis ◽  
Maziyar Saberi ◽  
Toby L. Smith ◽  
Reza Jazayeri ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Insulin Secretion ◽  
Glucose Tolerance ◽  
Glucose Uptake ◽  
Whole Body ◽  
Glucose Disposal ◽  
High Fat ◽  
Insulin Resistant ◽  
Skeletal Muscle Glucose Uptake ◽  
Uptake And Transport

In addition to suppressing appetite, leptin may also modulate insulin secretion and action. Leptin was administered here to insulin-resistant rats to determine its effects on secretagogue-stimulated insulin release, whole body glucose disposal, and insulin-stimulated skeletal muscle glucose uptake and transport. Male Wistar rats were fed either a normal (Con) or a high-fat (HF) diet for 3 or 6 mo. HF rats were then treated with either vehicle (HF), leptin (HF-Lep, 10 mg · kg−1 · day−1 sc), or food restriction (HF-FR) for 12–15 days. Glucose tolerance and skeletal muscle glucose uptake and transport were significantly impaired in HF compared with Con. Whole body glucose tolerance and rates of insulin-stimulated skeletal muscle glucose uptake and transport in HF-Lep were similar to those of Con and greater than those of HF and HF-FR. The insulin secretory response to either glucose or tolbutamide (a pancreatic β-cell secretagogue) was not significantly diminished in HF-Lep. Total and plasma membrane skeletal muscle GLUT-4 protein concentrations were similar in Con and HF-Lep and greater than those in HF and HF-FR. The findings suggest that chronic leptin administration reversed a high-fat diet-induced insulin-resistant state, without compromising insulin secretion.

scholarly journals Carvacrol and Thymol Modulate the Cross-Talk between TNF-α and IGF-1 Signaling in Radiotherapy-Induced Ovarian Failure

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Yasmen F. Mahran ◽  
Amira M. Badr ◽  
Alhanouf Aldosari ◽  
Raghad Bin-Zaid ◽  
Hind N. Alotaibi
Keyword(s):  
Oxidative Stress ◽  
Cross Talk ◽  
Ovarian Failure ◽  
Radioprotective Effect ◽  
Whole Body ◽  
Nuclear Antigen ◽  
Hormonal Changes ◽  
Tnf Α ◽  
Ovarian Damage ◽  
The Cross

Premature ovarian failure (POF) is a common cause of infertility in premenopausal women who are unavoidably exposed to cytotoxic therapy. Radiotherapy is one of the most effective cytotoxic treatments. However, the radiosensitivity of ovarian tissues limits its therapeutic outcome and results in the depletion of the primordial follicle and loss of fertility. Therefore, the need for an effective radioprotective therapy is evident especially when none of the current clinically used modalities for radioprotection succeeds efficiently. The present study investigated the potential radioprotective effect of carvacrol (CAR) (80 mg) or thymol (80 mg) on gamma- (γ-) irradiation-induced ovarian damage as well as their role in the cross-talk between IGF-1 and TNF-α signaling and antioxidative activity. In immature female Wister rats, a single dose of whole-body irradiation (3.2 Gy, L D 20 ) produced considerable ovarian damage, which was evident by histopathological findings and hormonal changes. Interestingly, pretreatment with CAR or thymol significantly enhanced the follicular development and restored the anti-Mullerian hormone (AMH), E2, and FSH levels. Both essential oils improved the irradiation-mediated oxidative stress and reduction in proliferating cell nuclear antigen (PCNA) expression. Moreover, irradiated rats exhibited an inverse relationship between IGF-1 and TNF-α levels two days post irradiation, which was further inverted by the pretreatment with CAR and thymol and ought to contribute in their radioprotective mechanisms. In conclusion, CAR and thymol showed a radioprotective effect and rescued the ovarian reserve mainly through counteracting oxidative stress and the dysregulated cross-talk between IGF-1 and TNF-α.

scholarly journals Selective overexpression of Toll-like receptor-4 in skeletal muscle impairs metabolic adaptation to high-fat feeding

2015 ◽  
Vol 309 (3) ◽  
pp. R304-R313 ◽  
Author(s):  
Ryan P. McMillan ◽  
Yaru Wu ◽  
Kevin Voelker ◽  
Gabrielle Fundaro ◽  
John Kavanaugh ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
High Fat Diet ◽  
Whole Body ◽  
Metabolic Adaptation ◽  
Acid Oxidation ◽  
Chow Diet ◽  
Toll Like Receptor ◽  
High Fat ◽  
Toll Like Receptor 4 ◽  
Fat Feeding

Toll-like receptor-4 (TLR-4) is elevated in skeletal muscle of obese humans, and data from our laboratory have shown that activation of TLR-4 in skeletal muscle via LPS results in decreased fatty acid oxidation (FAO). The purpose of this study was to determine whether overexpression of TLR-4 in skeletal muscle alters mitochondrial function and whole body metabolism in the context of a chow and high-fat diet. C57BL/6J mice (males, 6–8 mo of age) with skeletal muscle-specific overexpression of the TLR-4 (mTLR-4) gene were created and used for this study. Isolated mitochondria and whole muscle homogenates from rodent skeletal muscle (gastrocnemius and quadriceps) were investigated. TLR-4 overexpression resulted in a significant reduction in FAO in muscle homogenates; however, mitochondrial respiration and reactive oxygen species (ROS) production did not appear to be affected on a standard chow diet. To determine the role of TLR-4 overexpression in skeletal muscle in response to high-fat feeding, mTLR-4 mice and WT control mice were fed low- and high-fat diets for 16 wk. The high-fat diet significantly decreased FAO in mTLR-4 mice, which was observed in concert with elevated body weight and fat, greater glucose intolerance, and increase in production of ROS and cellular oxidative damage compared with WT littermates. These findings suggest that TLR-4 plays an important role in the metabolic response in skeletal muscle to high-fat feeding.

scholarly journals The Dietary Replacement of Soybean Oil by Canola Oil Does Not Prevent Liver Fatty Acid Accumulation and Liver Inflammation in Mice

Nutrients ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3667
Author(s):  
Marina Masetto Antunes ◽  
Guilherme Godoy ◽  
Ingrid de Lima Fernandes ◽  
Luciana Pelissari Manin ◽  
Caroline Zappielo ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Soybean Oil ◽  
Mrna Expression ◽  
Canola Oil ◽  
Liver Inflammation ◽  
Liver Fatty Acid ◽  
Lipid Source ◽  
Fatty Acid Accumulation ◽  
Tnf Α ◽  
Acid Accumulation

A high-carbohydrate diet (HCD) is a well-established experimental model of accelerated liver fatty acid (FA) deposition and inflammation. In this study, we evaluated whether canola oil can prevent these physiopathological changes. We evaluated hepatic FA accumulation and inflammation in mice fed with a HCD (72.1% carbohydrates) and either canola oil (C group) or soybean oil (S group) as a lipid source for 0, 7, 14, 28, or 56 days. Liver FA compositions were analyzed by gas chromatography. The mRNA expression of acetyl-CoA carboxylase 1 (ACC1) was measured as an indicator of lipogenesis. The mRNA expression of F4/80, tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, and IL-10, as mediators of liver inflammation, were also measured. The C group stored less n-6 polyunsaturated FAs (n-6 PUFAs) and had more intense lipid deposition of monounsaturated FAs (MUFAs), n-3 PUFAs, and total FAs. The C group also showed higher ACC1 expression. Moreover, on day 56, the C group showed higher expressions of the inflammatory genes F4/80, TNF-α, IL-1β, and IL-6, as well as the anti-inflammatory IL-10. In conclusion, a diet containing canola oil as a lipid source does not prevent the fatty acid accumulation and inflammation induced by a HCD.

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