scholarly journals The 5,7-Dimethoxyflavone Suppresses Sarcopenia by Regulating Protein Turnover and Mitochondria Biogenesis-Related Pathways

Nutrients ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1079 ◽  
Author(s):  
Changhee Kim ◽  
Jae-Kwan Hwang

Sarcopenia is a muscle disease featured by the loss of muscle mass and dysfunction with advancing age. The 5,7-dimethoxyflavone (DMF), a major flavone found in Kaempferia parviflora, has biological activities, including anti-diabetes, anti-obesity, and anti-inflammation. However, its anti-sarcopenic effect remains to be elucidated. This current study investigated the inhibitory activity of DMF on sarcopenia. Eighteen-month-old mice were orally administered DMF at the dose of 25 mg·kg−1·day−1 or 50 mg·kg−1·day−1 for 8 weeks. DMF not only stimulated grip strength and exercise endurance but also increased muscle mass and volume. Besides, DMF stimulated the phosphatidylinositol 3-kinase-Akt pathway, consequently activating the mammalian target of rapamycin-eukaryotic initiation factor 4E-binding protein 1-70-kDa ribosomal protein S6 kinase pathway for protein synthesis. DMF reduced the mRNA expression of E3 ubiquitin ligase- and autophagy-lysosomal-related genes involved in proteolysis via the phosphorylation of Forkhead box O3. DMF upregulated peroxisome proliferator-activated receptor-gamma coactivator 1 alpha, nuclear respiratory factor 1, and mitochondrial transcription factor A along with the increase of relative mitochondrial DNA content. DMF alleviated inflammatory responses by reducing the tumor necrosis factor-alpha and interleukin-6 serum and mRNA levels. Collectively, DMF can be used as a natural agent to inhibit sarcopenia via improving protein turnover and mitochondria function.

2001 ◽  
Vol 193 (7) ◽  
pp. 827-838 ◽  
Author(s):  
Pierre Desreumaux ◽  
Laurent Dubuquoy ◽  
Sophie Nutten ◽  
Michel Peuchmaur ◽  
Walter Englaro ◽  
...  

The peroxisome proliferator–activated receptor γ (PPARγ) is highly expressed in the colon mucosa and its activation has been reported to protect against colitis. We studied the involvement of PPARγ and its heterodimeric partner, the retinoid X receptor (RXR) in intestinal inflammatory responses. PPARγ1/− and RXRα1/− mice both displayed a significantly enhanced susceptibility to 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis compared with their wild-type littermates. A role for the RXR/PPARγ heterodimer in the protection against colon inflammation was explored by the use of selective RXR and PPARγ agonists. TNBS-induced colitis was significantly reduced by the administration of both PPARγ and RXR agonists. This beneficial effect was reflected by increased survival rates, an improvement of macroscopic and histologic scores, a decrease in tumor necrosis factor α and interleukin 1β mRNA levels, a diminished myeloperoxidase concentration, and reduction of nuclear factor κB DNA binding activity, c-Jun NH2-terminal kinase, and p38 activities in the colon. When coadministered, a significant synergistic effect of PPARγ and RXR ligands was observed. In combination, these data demonstrate that activation of the RXR/PPARγ heterodimer protects against colon inflammation and suggest that combination therapy with both RXR and PPARγ ligands might hold promise in the clinic due to their synergistic effects.


2020 ◽  
Author(s):  
Dennis Awuah ◽  
Alisa Ruisinger ◽  
Meshal Alobaid ◽  
Chidimma Mbadugha ◽  
Amir M. Ghaemmaghami

AbstractThe peroxisome proliferator activated receptor gamma (PPARγ) is a ligand activated transcription factor expressed in dendritic cells (DCs), where it exerts anti-inflammatory responses against TLR4-induced inflammation. Recently, microRNA-511 (miR-511) has also emerged as a key player in controlling TLR4-mediated signalling, and in regulating the function of DCs. Interestingly, PPARγ has been previously highlighted as a putative target of miR-511 activity; however the link between miR-511 and PPARγ and its influence on human DC function within the context of LPS-induced inflammatory responses is unknown. Using a selection of miR-511-3p-specific inhibitors and mimics, we demonstrate for the first time that up or downregulation of miR-511-3p inversely correlates with PPARγ mRNA levels and transcriptional activity following treatment with PPARγ synthetic agonist rosiglitazone (RSG), in the presence or absence of LPS. Additionally, we show that PPARγ activation with RSG modulates LPS-induced DC activation and downregulates pro-inflammatory cytokine production following downregulation of miR-511-3p. Lastly, PPARγ activation was shown to suppress LPS-mediated induction of indoleamine 2,3-dioxygenase (IDO) activity in DCs, most likely due to changes in miR-511-3p expression. These data suggest that PPARγ-induced modulation of DC phenotype and function is influenced by miR-511-3p expression, which may serve as a potential therapeutic target against inflammatory diseases.


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Wei Zhang ◽  
Ming Peng ◽  
Yang Yang ◽  
Zhangwu Xiao ◽  
Bin Song ◽  
...  

Exertional heat stroke (EHS) results in a constellation of systemic inflammatory responses resulting in multiorgan failure and an extremely high mortality. The present study was designed to evaluate the protective effects of salidroside on EHS by improving mitochondrial functions in the rat model. Liver and heart mitochondria were observed by transmission electron microscopy and mitochondrial membrane potential (ΔΨm) was detected by a fluorescent probe. Intramitochondrial free Ca2+concentration, mitochondrial respiratory control ratio (RCR), reactive oxygen species (ROS) levels, superoxide dismutase (SOD), and malondialdehyde (MDA) activity were detected by the corresponding kits. RT-PCR was performed to estimate peroxisome proliferator-activated receptor-γcoactivator-1α(PGC-1α) and manganese form of SOD (MnSOD) mRNA expression. The results demonstrated that salidroside was able to relieve EHS damage by reducing the swelling of mitochondria, ROS levels, and MDA activity, as well as increasing ΔΨm, RCR, free Ca2+concentration, SOD, PGC-1α, and MnSOD mRNA levels. In conclusion, salidroside has protective effects on mitochondrial functions against exertional heat stroke-induced organ damage in the rat.


Immuno ◽  
2022 ◽  
Vol 2 (1) ◽  
pp. 104-117
Author(s):  
Dennis Awuah ◽  
Alisa Ruisinger ◽  
Meshal Alobaid ◽  
Chidimma Mbadugha ◽  
Amir M. Ghaemmaghami

The peroxisome proliferator-activated receptor gamma (PPARγ) is a ligand-activated transcription factor expressed in dendritic cells (DCs), where it exerts anti-inflammatory responses against TLR4-induced inflammation. Recently, microRNA-511 (miR-511) has also emerged as a key player in controlling TLR4-mediated signalling and in regulating the function of DCs. Interestingly, PPARγ has been previously highlighted as a putative target of miR-511 activity; however, the link between miR-511 and PPARγ and its influence on human DC function within the context of LPS-induced inflammatory responses is unknown. Using a selection of miR-511-3p-specific inhibitors and mimics, we demonstrate for the first time that knockdown or overexpression of miR-511-3p inversely correlates with PPARγ mRNA levels and affects its transcriptional activity following treatment with rosiglitazone (RSG; PPARγ agonist), in the presence or absence of LPS. Additionally, we show that PPARγ-mediated suppression of DC activation and pro-inflammatory cytokine production in miR-511-3p knockdown DCs is abrogated following overexpression of miR-511-3p. Lastly, PPARγ activation suppressed LPS-mediated induction of indoleamine 2,3-dioxygenase (IDO) activity in DCs, most likely due to changes in miR-511-3p expression. Our data thus suggests that PPARγ-induced modulation of DC phenotype and function is influenced by miR-511-3p expression, which may serve as a potential therapeutic target against inflammatory diseases.


Author(s):  
Ryuni Kim ◽  
Hyebeen Kim ◽  
Minju Im ◽  
Sun Kyu Park ◽  
Hae Jung Han ◽  
...  

BST204 is a purified ginseng dry extract that has an inhibitory effect on lipopolysaccharide-induced inflammatory responses, but its effect on muscle atrophy is yet to be investigated. In this study, C2C12 myoblasts were induced to differentiate for three days followed by the treatment of dexamethasone (DEX), a corticosteroid drug, with vehicle or BST204 for one day and subjected to immunoblotting, immunocytochemistry, qRT-PCR and biochemical analysis for mitochondrial function. BST204 alleviates the myotube atrophic effect mediated by DEX via the activation of protein kinase B/mammalian target of rapamycin (Akt/mTOR) signaling. Through this pathway, BST204 suppresses the expression of muscle-specific E3 ubiquitin ligases contributing to the enhanced myotube formation and enlarged myotube diameter in DEX-treated myotubes. In addition, BST204 treatment significantly decreases the mitochondrial reactive oxygen species production in DEX-treated myotubes. Furthermore, BST204 improves mitochondrial function by upregulating the expression of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC1α) in DEX-induced myotube atrophy. This study provides a mechanistic insight into the effect of BST204 on DEX-induced myotube atrophy, suggesting that BST204 has protective effects against the toxicity of a corticosteroid drug in muscle and promising potential as a nutraceutical remedy for the treatment of muscle weakness and atrophy.


2008 ◽  
Vol 294 (1) ◽  
pp. E69-E77 ◽  
Author(s):  
Nathalie Koulmann ◽  
Lahoucine Bahi ◽  
Florence Ribera ◽  
Hervé Sanchez ◽  
Bernard Serrurier ◽  
...  

The present experiment was designed to examine the effects of hypothyroidism and calcineurin inhibition induced by cyclosporin A (CsA) administration on both contractile and metabolic soleus muscle phenotypes, with a novel approach to the signaling pathway controlling mitochondrial biogenesis. Twenty-eight rats were randomly assigned to four groups, normothyroid, hypothyroid, and orally treated with either CsA (25 mg/kg, N-CsA and H-CsA) or vehicle (N-Vh and H-Vh), for 3 wk. Muscle phenotype was estimated by the MHC profile and activities of oxidative and glycolytic enzymes. We measured mRNA levels of the peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), the major regulator of mitochondrial content. We also studied the expression of the catalytic A-subunit of calcineurin (CnA) both at protein and transcript levels and mRNA levels of modulatory calcineurin inhibitor proteins (MCIP)-1 and -2, which are differentially regulated by calcineurin activity and thyroid hormone, respectively. CsA-administration induced a slow-to-fast MHC transition limited to the type IIA isoform, which is associated with increased oxidative capacities. Hypothyroidism strongly decreased both the expression of fast MHC isoforms and oxidative capacities. Effects of CsA administration on muscle phenotype were blocked in conditions of thyroid hormone deficiency. Changes in the oxidative profile were strongly related to PGC-1α changes and associated with phosphorylation of p38 MAPK. Calcineurin and MCIPs mRNA levels were decreased by both hypothyroidism and CsA without additive effects. Taken together, these results suggest that adult muscle phenotype is primarily under the control of thyroid state. Physiological levels of thyroid hormone are required for the effects of calcineurin inhibition on slow oxidative muscle phenotype.


2021 ◽  
Vol 11 ◽  
Author(s):  
Elisabetta Murru ◽  
Gianfranca Carta ◽  
Claudia Manca ◽  
Valeria Sogos ◽  
Marco Pistis ◽  
...  

Fatty acids play a crucial role in the brain as specific receptor ligands and as precursors of bioactive metabolites. Conjugated linoleic acid (CLA), a group of positional and geometric isomers of linoleic acid (LA, 18:2 n-6) present in meat and dairy products of ruminants and synthesized endogenously in non-ruminants and humans, has been shown to possess different nutritional properties associated with health benefits. Its ability to bind to peroxisome proliferator-activated receptor (PPAR) α, a nuclear receptor key regulator of fatty acid metabolism and inflammatory responses, partly mediates these beneficial effects. CLA is incorporated and metabolized into brain tissue where induces the biosynthesis of endogenous PPARα ligands palmitoylethanolamide (PEA) and oleoylethanolamide (OEA), likely through a positive feedback mechanism where PPARα activation sustains its own cellular effects through ligand biosynthesis. In addition to PPARα, PEA and OEA may as well bind to other receptors such as TRPV1, further extending CLA own anti-neuroinflammatory actions. Future studies are needed to investigate whether dietary CLA may exert anti-inflammatory activity, particularly in the setting of neurodegenerative diseases and neuropsychiatric disorders with a neuroinflammatory basis.


2010 ◽  
Vol 56 (4) ◽  
pp. 480-489
Author(s):  
E.N. Pivovarova ◽  
N.V. Baginskaya ◽  
M.L. Perepechaeva ◽  
S.I. Ilnitskaya ◽  
M.I. Dushkin

Earlier it was shown that male mice of the DD/He strain were highly susceptible to ortho-aminoasotoluene (OAT) induced hepatocarcinogenesis, and resistant to spontaneous liver tumor development as compared to the СС57BR/Mv strain. In the present work we have made a comparative investigation of peroxisome proliferator-activated receptor (PPAR), liver X-receptor (LXR) and retinoic X-receptor (RXR) mRNA levels in liver as well as concentrations of corticosterone, glucose, lipids and insulin in blood of male DD/He and СС57BR/Mv mice. Using the multiplex RT-PCR method it was found that PPAR-α, PPAR-γ, RXR-α and RXR-β mRNA content was essentially decreased in the liver of DD mice as compared to mice of the СС57BR strain. No significant interstrain differences of LXR-α and LXR-β mRNA content were found. In DD micetere was more then the 3-fold decrease of blood content of corticosterone, which is involved in PPAR and RXR regulation. DD mice demonstrated a significant decrease in blood serum glucose and insulin concentrations as well as higher reactivity to insulin as compared with СС57BR mice. Elevated blood total cholesterol and cholesterol HDL level were found in DD mice whereas triglyceride content was basically the same in both mouse strains. It is known that glucocorticoids, PPAR and RXR play crucial role in transcription regulation of inflammation response. Therefore our data allow to suggest that decreased corticosterone level in blood, PPAR and RXR mRNA content in liver of the DD strain may lead to induction of inflammation by OAT exposure, resulting in a high incidence of tumorigenesis in this strain.


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