scholarly journals HMGB1 Is Involved in the Protective Effect of the PPARαAgonist Fenofibrate against Cardiac Hypertrophy

PPAR Research ◽  
2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Zhankui Jia ◽  
Rui Xue ◽  
Gangqiong Liu ◽  
Ling Li ◽  
Jinjian Yang ◽  
...  

High mobility group box 1 (HMGB1) is a ubiquitous nuclear DNA-binding protein whose function is dependent on its cellular location. Extracellular HMGB1 is regarded as a delayed mediator of proinflammatory cytokines for initiating and amplifying inflammatory responses, whereas nuclear HMGB1 has been found to prevent cardiac hypertrophy and heart failure. Because fenofibrate, a peroxisome proliferator-activated receptorα(PPARα) agonist, has shown both protective effects against cardiac hypertrophy and inhibitory effects against inflammation, the potential modulation of HMGB1 expression and secretion by fenofibrate is of great interest. We herein provide evidence that fenofibrate modulates basal and LPS-stimulated HMGB1 expression and localization in addition to secretion of HMGB1 in cardiomyocytes. In addition, administration of fenofibrate to mice prevented the development of cardiac hypertrophy induced by thoracic transverse aortic constriction (TAC) while increasing levels of nuclear HMGB1. Altogether, these data suggest that fenofibrate may inhibit the development of cardiac hypertrophy by regulating HMGB1 expression, which provides a new potential strategy to treat cardiac hypertrophy.

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.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4208 ◽  
Author(s):  
Jung Seok Hwang ◽  
Eun Sil Kang ◽  
Sung Gu Han ◽  
Dae-Seog Lim ◽  
Kyung Shin Paek ◽  
...  

Background The release of high mobility group box 1 (HMGB1) induced by inflammatory signals acts as a cellular alarmin to trigger a chain of inflammatory responses. Although the inflammatory actions of HMGB1 are well studied, less is known about the therapeutic agents that can impede its release. This study investigated whether the isoflavonoid formononetin can modulate HMGB1 release in cellular inflammatory responses. Methods RAW264.7 murine macrophages were exposed to lipopolysaccharide (LPS) in the presence or absence of formononetin. The levels of HMGB1 release, sirtuin 1 (SIRT1) expression, and HMGB1 acetylation were analyzed by immunoblotting and real-time polymerase chain reaction. The effects of resveratrol and sirtinol, an activator and inhibitor of SIRT1, respectively, on LPS-induced HMGB1 release were also evaluated. Results Formononetin modulated cellular inflammatory responses by suppressing the release of HMGB1 by macrophages exposed to LPS. In RAW264.7 cells, formononetin significantly attenuated LPS-induced release of HMGB1 into the extracellular environment, which was accompanied by a reduction in its translocation from the nucleus to the cytoplasm. In addition, formononetin significantly induced mRNA and protein expression of SIRT1 in a peroxisome proliferator-activated receptor δ (PPARδ)-dependent manner. These effects of formononetin were dramatically attenuated in cells treated with small interfering RNA (siRNA) against PPARδ or with GSK0660, a specific inhibitor of PPARδ, indicating that PPARδ is involved in formononetin-mediated SIRT1 expression. In line with these effects, formononetin-mediated inhibition of HMGB1 release in LPS-treated cells was reversed by treatment with SIRT1-targeting siRNA or sirtinol, a SIRT1 inhibitor. By contrast, resveratrol, a SIRT1 activator, further potentiated the inhibitory effect of formononetin on LPS-induced HMGB1 release, revealing a possible mechanism by which formononetin regulates HMGB1 release through SIRT1. Furthermore, modulation of SIRT1 expression by transfection of SIRT1- or PPARδ-targeting siRNA significantly counteracted the inhibitory effects of formononetin on LPS-induced HMGB1 acetylation, which was responsible for HMGB1 release. Discussion This study shows for the first time that formononetin inhibits HMGB1 release by decreasing HMGB1 acetylation via upregulating SIRT1 in a PPARδ-dependent manner. Formononetin consequently exhibits anti-inflammatory activity. Identification of agents, such as formononetin, which can block HMGB1 release, may help to treat inflammation-related disorders.


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.


2021 ◽  
Vol 12 ◽  
Author(s):  
Ruizhen Huang ◽  
Chiyu Zhang ◽  
Xing Wang ◽  
Honglin Hu

Ischemia-reperfusion injury (IRI) is a complex pathophysiological process that is often characterized as a blood circulation disorder caused due to various factors (such as traumatic shock, surgery, organ transplantation, burn, and thrombus). Severe metabolic dysregulation and tissue structure destruction are observed upon restoration of blood flow to the ischemic tissue. Theoretically, IRI can occur in various tissues and organs, including the kidney, liver, myocardium, and brain, among others. The advances made in research regarding restoring tissue perfusion in ischemic areas have been inadequate with regard to decreasing the mortality and infarct size associated with IRI. Hence, the clinical treatment of patients with severe IRI remains a thorny issue. Peroxisome proliferator-activated receptor γ (PPARγ) is a member of a superfamily of nuclear transcription factors activated by agonists and is a promising therapeutic target for ameliorating IRI. Therefore, this review focuses on the role of PPARγ in IRI. The protective effects of PPARγ, such as attenuating oxidative stress, inhibiting inflammatory responses, and antagonizing apoptosis, are described, envisaging certain therapeutic perspectives.


PPAR Research ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Si-Chi Xu ◽  
Zhen-Guo Ma ◽  
Wen-Ying Wei ◽  
Yu-Pei Yuan ◽  
Qi-Zhu Tang

Background. Peroxisome proliferator-activated receptor-α (PPAR-α) is closely associated with the development of cardiac hypertrophy. Previous studies have indicated that bezafibrate (BZA), a PPAR-α agonist, could attenuate insulin resistance and obesity. This study was designed to determine whether BZA could protect against pressure overload-induced cardiac hypertrophy. Methods. Mice were orally given BZA (100 mg/kg) for 7 weeks beginning 1 week after aortic banding (AB) surgery. Cardiac hypertrophy was assessed based on echocardiographic, histological, and molecular aspects. Moreover, neonatal rat ventricular cardiomyocytes (NRVMs) were used to investigate the effects of BZA on the cardiomyocyte hypertrophic response in vitro. Results. Our study demonstrated that BZA could alleviate cardiac hypertrophy and fibrosis in mice subjected to AB surgery. BZA treatment also reduced the phosphorylation of protein kinase B (AKT)/glycogen synthase kinase-3β (GSK3β) and mitogen-activated protein kinases (MAPKs). BZA suppressed phenylephrine- (PE-) induced hypertrophy of cardiomyocyte in vitro. The protective effects of BZA were abolished by the treatment of the PPAR-α antagonist in vitro. Conclusions. BZA could attenuate pressure overload-induced cardiac hypertrophy and fibrosis.


2021 ◽  
Vol 11 (3) ◽  
pp. 325
Author(s):  
Fatima M. Shakova ◽  
Yuliya I. Kirova ◽  
Denis N. Silachev ◽  
Galina A. Romanova ◽  
Sergey G. Morozov

The pharmacological induction and activation of peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α), a key regulator of ischemic brain tolerance, is a promising direction in neuroprotective therapy. Pharmacological agents with known abilities to modulate cerebral PGC-1α are scarce. This study focused on the potential PGC-1α-modulating activity of Mexidol (2-ethyl-6-methyl-3-hydroxypyridine succinate) and Semax (ACTH(4–7) analog) in a rat model of photochemical-induced thrombosis (PT) in the prefrontal cortex. Mexidol (100 mg/kg) was administered intraperitoneally, and Semax (25 μg/kg) was administered intranasally, for 7 days each. The expression of PGC-1α and PGC-1α-dependent protein markers of mitochondriogenesis, angiogenesis, and synaptogenesis was measured in the penumbra via immunoblotting at Days 1, 3, 7, and 21 after PT. The nuclear content of PGC-1α was measured immunohistochemically. The suppression of PGC-1α expression was observed in the penumbra from 24 h to 21 days following PT and reflected decreases in both the number of neurons and PGC-1α expression in individual neurons. Administration of Mexidol or Semax was associated with preservation of the neuron number and neuronal expression of PGC-1α, stimulation of the nuclear translocation of PGC-1α, and increased contents of protein markers for PGC-1α activation. This study opens new prospects for the pharmacological modulation of PGC-1α in the ischemic brain.


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.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Michinari Nakamura ◽  
Peiyong Zhai ◽  
Junichi Sadoshima

Obesity and insulin resistance (IR) lead to impaired cardiac metabolism, resulting in cardiac dysfunction. However, the underlying mechanisms responsible for the development of cardiac dysfunction remain poorly understood. PPARα serves as a key regulator of fatty acid (FA) metabolism in the heart. GSK-3α, a serine/threonine kinase, was dephosphorylated at S21 and activated (2.0 fold, p<0.05) in the hearts of obese mice fed a high-fat diet (HFD) and ob/ob mice. To evaluate the functional significance of GSK-3α upregulation, wild-type (WT) and cardiac specific GSK-3α heterozygous knockout (cGSK-3α HKO) mice were fed a HFD for up to 14 weeks. There was no difference in the food intake or body weight change between WT and cGSK-3α HKO mice. However, cardiac hypertrophy and diastolic dysfunction observed in WT mice were significantly ameliorated in cGSK-3α HKO mice after HFD feeding (8.1± 0.6 and 6.5±0.5, LVW/TL; 24.8±0.9 and 16.6±0.8, deceleration time (DT), all p<0.05). FA oxidation (FAO) (0.81 fold) and ectopic lipid accumulation (Oil Red O staining) were significantly decreased in cGSK-3α HKO mice than in WT mice after HFD feeding. GSK-3α, but not GSK-3β, directly interacted with and phosphorylated PPARα at the ligand binding domain in cardiomyocytes (CMs) and in the heart. PPARα phosphorylation in the heart was significantly increased (2.1 fold, p<0.05) in response to HFD, but it was attenuated in cGSK-3α HKO mice (0.74 fold, p<0.05). Fenofibrate, a PPARα ligand, inhibited GSK-3α-induced PPARα phosphorylation (0.81 fold, p<0.05), reduced ectopic lipid accumulation, FAO (0.84 fold, p<0.05), and attenuated diastolic dysfunction (25.5±3.1 and 18.6±2.5, DT; 0.16±0.04 and 0.08±0.02, EDPVR, all p<0.05) in the heart of HFD fed mice. Collectively, these results suggest that GSK-3α increases PPARα activity through phosphorylation of PPARα, which is inhibited by Fenofibrate. Activation of GSK-3α and consequent phosphorylation of PPARα during obesity and IR could play an important role in the development of cardiac hypertrophy and diastolic dysfunction. Synthetic PPARα ligands inhibit GSK-3α-mediated phosphorylation of PPARα, thereby paradoxically attenuating excessive FA metabolism in cardiomyocytes.


Author(s):  
Xiao- Bei Zhang ◽  
Jintao Li ◽  
Juanhua Gu ◽  
Yue-Qin Zeng

: Alzheimer’s disease (AD) is one of the most common neurodegenerative diseases with chronic, progressive, and irreversible characteristics, affecting nearly 50 million older adults worldwide. The pathogenesis of AD includes the formation of senile plaques, the abnormal aggregation of tau protein and the gradual degeneration and death of cerebral cortical cells. The main symptoms are memory loss, cognitive decline and behavioral disorders. Studies indicate that cannabidiol(CBD) possesses various pharmacological activities including anti-inflammatory, anti-oxidation and neuroprotective activities. It has been suggested as a potential multi-target medicine for treatment of AD. In this review, we aim to summarize the underlying mechanisms and protective effects of CBD on signaling pathways and central receptors involved in the pathogenesis of AD, including the endocannabinoid system(eCBs), the Transient receptor potential vanilloid type 1(TRPV1) receptor, and the Peroxisome proliferator-activated receptor (PPAR) receptor.


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