Abstract 292: Brain Derived Neurotrophic Factor Induced Upregulation Of Peroxisome Proliferator-activated Receptor Gamma Coactivator 1-alpha Signaling Prevents Hearts From Heart Failure Progression Against Pressure Overload

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Ning Feng ◽  
Guangshuo Zhu ◽  
vidhya Sivakumaran ◽  
Manling Zhang ◽  
Djahida Bedja ◽  
...  

Background: The heart is under the influence of neurotrophins (NTs) secreted from peripheral sympathetic nerves, including brain derived neurotrophic factor (BDNF). BDNF is indispensible for cardiac development and vascular wall integrity. Yet, whether BDNF signaling plays a role in governing cardiac function in response to stress is unclear. Hypothesis: BDNF signaling contributes to maintain proper cardiac structure/function in pressure overloaded mice. Results: BDNF expression is markedly down-regulated in hearts subjected to transverse aortic constriction (TAC). Cardiac specific over-expression of BDNF (BDNF-TG) or administration of a BDNF-mimetic agonist (LM22A-4) preserved cardiac function against pressure overload. In contrast, cardiac-selective deletion of the BDNF receptor, Tropomyosin related kinase receptor B (TrkB), further exacerbated heart failure. In neurons, BDNF up-regulates Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) that regulates energy metabolism and mitochondrial function/biogenesis. Oxidative stress is a major negative modulator of PGC-1a expression/activity. Exposing neonatal rat ventricular myocytes (NRVMs) to hydrogen peroxide downregulated PGC-1α, and BDNF restored it to normal levels, with a concomitant up-regulation of downstream genes involved in both mitochondrial biogenesis and oxidative stress, resulting in attenuated ROS production and increased mitochondrial biogenesis. Consistent with the cultured myocyte findings, PGC-1α and downstream genes were up-regulated in BDNF-TG mice subjected to TAC, associated with attenuated oxidative stress and improved mitochondrial biogenesis; whereas TrkB-/- mice subjected to TAC displayed further decreased PGC-1α expression with worsened oxidative stress and impaired mitochondrial biogenesis. Conclusion: Our data show that BDNF confers protection against pressure overload via enhanced PGC-1α signaling that in turn prevents oxidative stress and improves mitochondrial biogenesis. Our data suggest BDNF/trkB is a promising new therapeutic avenue to prevent or retard heart failure.

2018 ◽  
Vol 32 (4) ◽  
pp. 469-481 ◽  
Author(s):  
Yu-Fei Ni ◽  
Hao Wang ◽  
Qiu-Yan Gu ◽  
Fei-Ying Wang ◽  
Ying-Jie Wang ◽  
...  

Major depressive disorder has become one of the most serious neuropsychiatric disorders worldwide. However, currently available antidepressants used in clinical practice are ineffective for a substantial proportion of patients and always have side effects. Besides being a lipid-regulating agent, gemfibrozil is an agonist of peroxisome proliferator-activated receptor-α (PPAR-α). We investigated the antidepressant effects of gemfibrozil on C57BL/6J mice using the forced swim test (FST) and tail suspension test (TST), as well as the chronic unpredictable mild stress (CUMS) model of depression. The changes in brain-derived neurotrophic factor (BDNF) signaling cascade in the brain after CUMS and gemfibrozil treatment were further assessed. Pharmacological inhibitors and lentivirus-expressed short hairpin RNA (shRNA) were also used to clarify the antidepressant mechanisms of gemfibrozil. Gemfibrozil exhibited significant antidepressant actions in the FST and TST without affecting the locomotor activity of mice. Chronic gemfibrozil administration fully reversed CUMS-induced depressive-like behaviors in the FST, TST and sucrose preference test. Gemfibrozil treatment also restored CUMS-induced inhibition of the hippocampal BDNF signaling pathway. Blocking PPAR-α and BDNF but not the serotonergic system abolished the antidepressant effects of gemfibrozil on mice. Gemfibrozil produced antidepressant effects in mice by promoting the hippocampal BDNF system.


2021 ◽  
Vol 19 ◽  
Author(s):  
Nihar Ranjan Das ◽  
Bhupesh Vaidya ◽  
Pragyanshu Khare ◽  
Mahendra Bishnoi ◽  
Shyam Sunder Sharma

Background: PPAR gamma co-activator 1α (PGC-1α) is known as the master regulator of mitochondrial biogenesis. It is also a co-activator of peroxisome proliferator-activated receptor-gamma (PPARγ) and plays a role in preventing mitochondrial dysfunction in several neurodegenerative disorders, including Parkinson’s disease (PD). Depletion in the levels of these proteins has been linked to oxidative stress, inflammation, and DNA damage, all of which are known to contribute to the pathogenesis of PD. Objective: In the present study, combination therapy of PPARγ agonist (GW1929) and PGC-1α activator (alpha-lipoic acid) was employed to ameliorate cognitive deficits, oxidative stress, and inflammation associated with the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of PD. Results: Our study showed that MPTP-induced PD rats exhibited an increase in oxidative stress and inflammation, leading to cognitive deficits. Furthermore, MPTP-induced PD rats also exhibited reduced mitochondrial biogenesis in comparison to control and sham animals. Intraperitoneal administration of GW 1929 and alpha-lipoic acid in doses lower than those earlier reported individually in literature led to an improvement in the cognitive deficits in comparison to MPTP-induced PD rats. These improvements were accompanied by a reduction in the levels of oxidative stress and inflammation. In addition, an increase in mitochondrial biogenesis was also observed after the combination of these pharmacological agents. Conclusion: Our results provide a rationale for the development of agents targeting PPARγ and PGC-1α as potent therapeutics for the treatment of neurological diseases like PD.


2020 ◽  
Vol 127 (Suppl_1) ◽  
Author(s):  
Natasha Fillmore ◽  
Junhui Sun ◽  
Danielle Springer ◽  
Elizabeth Murphy

Alterations in glucose and fatty acid metabolism are believed to contribute to the development of heart failure. Peroxisome Proliferator Activated Receptor α (PPARα) is a transcription factor that regulates fatty acid metabolism and is frequently reported to be reduced in heart failure. However, it is controversial whether this decline in PPARα mediates the development of cardiac hypertrophy and heart failure. To improve our understanding of the role of cardiac PPARα we generated a tamoxifen inducible cardiac-specific PPARα knockout mouse (cPPAR -/- ). Control (Mer-Cre-Mer and Flox -/- ) mice and cPPAR -/- (Mer-Cre-Mer and Flox +/+ ) mice were treated with tamoxifen at ~2.5 months and were studied 5 weeks after treatment. We verified loss of cardiac PPARα using western blot. cPPAR -/- mice appear healthy with normal body weight gain and survival. To examine the impact of cardiac deletion of PPARα on cardiac function we performed echocardiography on control and cPPAR -/- . There was no reduction in systolic function between control and cPPAR -/- mice. Ejection fraction (Control, 56.3±0.9; cPPAR -/- , 59.7±0.1) and fractional shortening (Control, 29.1±0.5; cPPAR -/- , 31.5±0.1) were similar in cPPAR -/- compared to control hearts. Interestingly however, baseline heart rate was significantly lower in cPPAR -/- versus control mice (Control, 531.3±18.3; cPPAR -/- , 459.8±2.9 bpm). In addition to having normal cardiac function, heart weights were similar between control and cPPAR -/- mice. Overall, these data indicate that an acute reduction in myocardial PPARα per se does not cause cardiac dysfunction. However these data do not exclude the possibility that loss of PPARα could drive cardiac pathology in the context of other signals.


2020 ◽  
Vol 11 (7) ◽  
Author(s):  
Junyan Wang ◽  
Bo Deng ◽  
Qing Liu ◽  
Yusheng Huang ◽  
Weitao Chen ◽  
...  

Abstract Chronic heart failure (CHF) is the final outcome of many cardiovascular diseases, and is a severe health issue faced by the elderly population. Mixed lineage kinase 3 (MLK3), a member of MAP3K family, is associated with aging, inflammation, oxidative stress, and related diseases, such as CHF. MLK3 has also been reported to play an important role in protecting against cardiomyocyte injury; however, its function in myocardial fibrosis is unknown. To investigate the role of MLK3 in myocardial fibrosis, we inhibited the expression of MLK3, and examined cardiac function and remodeling in TAC mice. In addition, we assessed the expression of MLK3 protein in ventricular cells and its downstream associated protein. We found that MLK3 mainly regulates NF-κB/NLRP3 signaling pathway-mediated inflammation and that pyroptosis causes myocardial fibrosis in the early stages of CHF. Similarly, MLK3 mainly regulates the JNK/p53 signaling pathway-mediated oxidative stress and that ferroptosis causes myocardial fibrosis in the advanced stages of CHF. We also found that promoting the expression of miR-351 can inhibit the expression of MLK3, and significantly improve cardiac function in mice subjected to TAC. These results suggest the pyroptosis and ferroptosis induced by MLK3 signaling in cardiomyocytes are essential for adverse myocardial fibrosis, in response to pressure overload. Furthermore, miR-351, which has a protective effect on ventricular remodeling in heart failure caused by pressure overload, may be a key target for the regulation of MLK3.


2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Xue Han ◽  
Daili Chen ◽  
Ning Liufu ◽  
Fengtao Ji ◽  
Qingshi Zeng ◽  
...  

Background. The heart is one of the most commonly affected organs during sepsis. Mitsugumin-53 (MG53) has attracted attention in research due to its cardioprotective function. However, the role of MG53 in sepsis-induced myocardial dysfunction (SIMD) remains unknown. The purpose of this study was to explore the underlying mechanism of MG53 in SIMD and investigate its potential relationship with peroxisome proliferator-activated receptor-α (PPARα). Methods. The cecal ligation and puncture (CLP) model was created to induce SIMD in rats. Protein levels of MG53 and PPARα, cardiac function, cardiomyocyte injury, myocardial oxidative stress and inflammatory indicators, and cardiomyocyte apoptosis were measured at 18 h after CLP. The effects of MG53 on PPARα in SIMD were investigated via preconditioning recombinant human MG53 (rhMG53) and PPARα antagonist GW6471. Results. The expression of MG53 and PPARα sharply decreased in the myocardium at 18 h after CLP. Compared with the sham group, cardiac function was significantly depressed, which was associated with the destructed myocardium, upregulated oxidative stress indicators and proinflammatory cytokines, and excessive cardiomyocyte apoptosis in the CLP group. Supplementation with rhMG53 enhanced myocardial MG53, increased the survival rate with improved cardiac function, and reduced oxidative stress, inflammation, and myocardial apoptosis, which were associated with PPARα upregulation. Pretreatment with GW6471 abolished the abovementioned protective effects induced by MG53. Conclusions. Both MG53 and PPARα were downregulated after sepsis shock. MG53 supplement protects the heart against SIMD by upregulating PPARα expression. Our results provide a new treatment strategy for SIMD.


2021 ◽  
Vol 12 ◽  
Author(s):  
Zhihui Yin ◽  
Xinyue Geng ◽  
Zhengyi Zhang ◽  
Ying Wang ◽  
Xiaoyan Gao

Neuronal mitochondrial oxidative stress induced by β-amyloid (Aβ) is an early event of Alzheimer’s disease (AD). Emerging evidence has shown that antioxidant therapy represents a promising therapeutic strategy for the treatment of AD. In this study, we investigated the antioxidant activity of rhein against Aβ1-42 oligomer-induced mitochondrial oxidative stress in primary neurons and proposed a potential antioxidant pathway involved. The results suggested that rhein significantly reduced reactive oxygen species (ROS) level, reversed the depletion of mitochondrial membrane potential, and protected neurons from oxidative stress-associated apoptosis. Moreover, further study indicated that rhein activated mitochondrial biogenesis accompanied by increased cytochrome C oxidase (CytOx) and superoxide dismutase (SOD) activities. CytOx on the respiratory chain inhibited the production of ROS from electron leakage and SOD helped to eliminate excess ROS. Finally, western blot analysis confirmed that rhein remarkedly increased the protein expression of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) together with its upstream deacetylase sirtuin 1 (SIRT1), and activated downstream transcription factor nuclear respiratory factor 1, promoting mitochondrial biogenesis. In conclusion, our results demonstrate that rhein activates mitochondrial biogenesis regulated by the SIRT1/PGC-1α pathway as an antioxidant defense system against Aβ1-42 oligomer-induced oxidative stress. These findings broaden our knowledge of improving mitochondrial biogenesis as an approach for relieving neuronal oxidative stress in AD.


2013 ◽  
Vol 115 (11) ◽  
pp. 1618-1625 ◽  
Author(s):  
Chounghun Kang ◽  
Li Li Ji

Prolonged immobilization (IM) results in skeletal muscle atrophy accompanied by increased reactive oxygen species (ROS) generation, inflammation, and protein degradation. However, the biological consequence of remobilizing such muscle has been studied only sparsely. In this study, we examined the peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α)-controlled mitochondrial biogenesis pathway and inflammatory response in mice subjected to 2 wk of hindlimb IM followed by 5 days of remobilization (RM). We hypothesized that ROS generation and activation of redox-sensitive signaling pathways play important roles in the etiology of muscle injury. FVB/N mice (age 2 mo) were randomly assigned to either 14 days of IM by casting one of the hindlimbs ( n = 7), IM followed by 5 days of RM with casting removed ( n = 7), or to a control group (Con; n = 7). Muscle to body weight ratios of three major leg muscles were significantly decreased as a result of IM. Two ubiquitin-proteasome pathway enzymes, muscle atrophy F-box (MAFb or atrogin-1) and muscle ring finger-1 (MuRF-1), were upregulated with IM and maintained at high levels during RM. Protein contents of PGC-1α and nuclear respiratory factors 1 and 2 in tibialis anterior (TA) muscle were reduced by 50% ( P < 0.01) in IM vs. Con, with no recovery observed during RM. IM suppressed mitochondrial transcription factor A and cytochrome- c content by 57% and 63% ( P < 0.01), respectively, and cytochrome- c oxidase activity by 58% ( P < 0.05). Furthermore, mitochondrial DNA content was reduced by 71% ( P < 0.01) with IM. None of these changes were reversed after RM. With RM, TA muscle showed a 2.3-fold ( P < 0.05) higher H2O2 content and a 4-fold ( P < 0.01) higher 8-isoprostane content compared with Con, indicating oxidative stress. Tumor necrosis factor-α and interleukin-6 levels in TA muscle were 4- and 3-fold higher ( P < 0.05), respectively, in IM and RM vs. CON. The nuclear factor-κB (NF-κB) pathway activation was observed only after RM, but not after IM alone. These data indicate an increase in ROS generation during the initial phase of muscle RM that could activate the NF-κB pathway, and elicit inflammation and oxidative stress. These events may hinder muscle recovery from IM-induced mitochondrial deterioration and protein loss.


2014 ◽  
Vol 307 (9) ◽  
pp. H1307-H1316 ◽  
Author(s):  
Georgios Karamanlidis ◽  
Lorena Garcia-Menendez ◽  
Stephen C. Kolwicz ◽  
Chi Fung Lee ◽  
Rong Tian

Mitochondrial dysfunction in animal models of heart failure is associated with downregulation of the peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α pathway. To test whether PGC-1α is an appropriate therapeutic target for increasing mitochondrial biogenesis and improving function in heart failure, we used a transgenic (TG) mouse model of moderate overexpression of PGC-1α (∼3-fold) in the heart. TG mice had small increases in citrate synthase activity and mitochondria size in the heart without alterations in myocardial energetics or cardiac function at baseline. In vivo dobutamine stress increased fractional shortening in wild-type mice, but this increase was attenuated in TG mice, whereas ex vivo isolated perfused TG hearts demonstrated normal functional and energetic response to high workload challenge. When subjected to pressure overload by transverse aortic constriction (TAC), TG mice displayed a significantly greater acute mortality for both male and female mice; however, long-term survival up to 8 wk was similar between the two groups. TG mice also showed a greater decrease in fractional shortening and a greater increase in left ventricular chamber dimension in response to TAC. Mitochondrial gene expression and citrate synthase activity were mildly increased in TG mice compared with wild-type mice, and this difference was also maintained after TAC. Our data suggest that a moderate level of PGC-1α overexpression in the heart compromises acute survival and does not improve cardiac function during chronic pressure overload in mice.


2021 ◽  
Vol 5 (Supplement_2) ◽  
pp. 45-45
Author(s):  
Kara Robinson ◽  
Bethany Hatter ◽  
Karley Washburn ◽  
James Bothwell ◽  
Kendall Anderson ◽  
...  

Abstract Objectives Sarcopenia, the progressive loss of muscle mass and strength, accelerates with age. Current recommendations to prevent sarcopenia focus on exercise and protein intake. Tart cherry (TC) has shown beneficial effects on muscle recovery following exercise. In this study, we investigated the effects of TC alone and in combination with exercise on lean mass, mitochondrial biogenesis, and oxidative stress in young compared to older mice. Methods In two cohorts (6 & 52 wk-old), female C57BL/6 mice were randomly assigned to 4 groups in a 2 × 2 factorial design with diet (AIN-93 control or TC supplemented at 10% w/w) and exercise as factors. Exercise consisted of treadmill running for 30 min, 5 d/wk, at 12 m/min and a 5° incline. Food intake was recorded daily and body weights weekly. After 8 wks, body composition was assessed using dual-energy x-ray absorptiometry. The gastrocnemius muscle was collected for protein analysis. Western blotting techniques were used to probe for superoxide dismutase 2 (SOD2) and peroxisome proliferator-activated receptor-gamma coactivator 1-alpha (PGC1a), indicators of oxidative stress and mitochondrial biogenesis. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) was used as loading control. Data were analyzed using 2-way ANOVA with α = 0.05. Results In young mice, TC had no effect on body weight and % lean mass, but led to decreased (P &lt; 0.05) % fat mass compared to controls. Exercise decreased (P &lt; 0.05) body weight and % fat, and tended to increase (P = 0.069) % lean mass. In contrast, TC and exercise independently decreased body weight and % fat, and increased % lean mass in older mice compared to controls. The combination of TC and exercise tended to have a synergistic effect on % lean mass (P = 0.056). Preliminary results show that TC significantly up-regulated SOD2 protein expression in young mice, but no effect was observed with exercise or combined treatments. PGC1α expression tended to be suppressed (P = 0.064) in young animals fed TC. To date, we have been unable to detect changes in SOD2 and PGC1α in older mice. Conclusions TC had a protective effect on lean tissue in older mice, preliminary analyses revealed no alterations in oxidative stress or mitochondrial biogenesis. Further investigation is warranted to understand the benefits of TC on lean muscle mass in older mice. Funding Sources Cherry Research Committee of the Cherry Marketing Institute


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