scholarly journals Quality Matters? The Involvement of Mitochondrial Quality Control in Cardiovascular Disease

Author(s):  
Kai-Lieh Lin ◽  
Shang-Der Chen ◽  
Kai-Jung Lin ◽  
Chia-Wei Liou ◽  
Yao-Chung Chuang ◽  
...  

Cardiovascular diseases are one of the leading causes of death and global health problems worldwide. Multiple factors are known to affect the cardiovascular system from lifestyles, genes, underlying comorbidities, and age. Requiring high workload, metabolism of the heart is largely dependent on continuous power supply via mitochondria through effective oxidative respiration. Mitochondria not only serve as cellular power plants, but are also involved in many critical cellular processes, including the generation of intracellular reactive oxygen species (ROS) and regulating cellular survival. To cope with environmental stress, mitochondrial function has been suggested to be essential during bioenergetics adaptation resulting in cardiac pathological remodeling. Thus, mitochondrial dysfunction has been advocated in various aspects of cardiovascular pathology including the response to ischemia/reperfusion (I/R) injury, hypertension (HTN), and cardiovascular complications related to type 2 diabetes mellitus (DM). Therefore, mitochondrial homeostasis through mitochondrial dynamics and quality control is pivotal in the maintenance of cardiac health. Impairment of the segregation of damaged components and degradation of unhealthy mitochondria through autophagic mechanisms may play a crucial role in the pathogenesis of various cardiac disorders. This article provides in-depth understanding of the current literature regarding mitochondrial remodeling and dynamics in cardiovascular diseases.

Author(s):  
Guoyong Li ◽  
Junli Li ◽  
Ruochen Shao ◽  
Jiahao Zhao ◽  
Mao Chen

Mitochondrial autophagy (or mitophagy) regulates the mitochondrial network and function to contribute to multiple cellular processes. The protective effect of homeostatic mitophagy in cardiovascular diseases (CVDs) has attracted increasing attention. FUN14 domain containing 1 (FUNDC1), an identified mitophagy receptor, plays an essential role in CVDs. Different expression levels of FUNDC1 and its phosphorylated state at different sites alleviate or exacerbate hypoxia and ischemia/reperfusion injury, cardiac hypertrophy, or metabolic damage through promotion or inhibition of mitophagy. In addition, FUNDC1 can be enriched at contact sites between mitochondria and the endoplasmic reticulum (ER), determining the formation of mitochondria-associated membranes (MAMs) that regulate cellular calcium (Ca2+) homeostasis and mitochondrial dynamics to prevent heart dysfunction. Moreover, FUNDC1 has also been involved in inflammatory cardiac diseases such as septic cardiomyopathy. In this review, we collect and summarize the evidence on the roles of FUNDC1 exclusively in various CVDs, describing its interactions with different cellular organelles, its involvement in multiple cellular processes, and its associated signaling pathways. FUNDC1 may become a promising therapeutic target for the prevention and management of various CVDs.


Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Inna Rabinovich-Nikitin ◽  
Illana Posen ◽  
Victoria Margulets ◽  
Tami A Martino ◽  
Lorrie A Kirshenbaum

Cardiac function is highly reliant on mitochondrial oxidative metabolism and fitness. The circadian clock is critically linked to vital physiological process including mitochondrial fission, fusion and quality control mechanisms. However, little is known of how the circadian clock regulates these vital processes in the heart. Herein, we identified a putative circadian Clock - mitochondrial interactome that gates an adaptive stress response for cell viability during myocardial ischemia reperfusion (I-R) injury. We show that Clock transcriptionally coordinates expression of mitochondrial dynamic fusion and fission, bioenergetic and quality control proteins in cardiac myocytes. Transcriptome and gene ontology mapping revealed Clock defective hearts subjected to I-R exhibited major transcriptional deficits in several key survival processes including mitochondrial dynamics, bioenergetics and autophagy that were reduced further following I-R. Gain of function of Clock activity re-established gene transcription of mitochondrial respiratory complex activity, quality control mechanisms and cell viability. Collectively, our data show that mitochondrial fitness and cell survival is mutually dependent upon and obligatorily linked to transcription of the circadian Clock gene in cardiac myocytes. Our data suggest the functional loss of Clock activity predisposes cardiac myocytes to metabolic catastrophe. Hence, therapeutic strategies designed to preserve circadian clock activity in the hearts may prove beneficial in reducing morbidity and mortality following ischemia -related pathologies such as myocardial infarction.


2021 ◽  
Vol 8 ◽  
Author(s):  
Yanguo Xin ◽  
Xiaodong Zhang ◽  
Jingye Li ◽  
Hui Gao ◽  
Jiayu Li ◽  
...  

IHD is a significant cause of mortality and morbidity worldwide. In the acute phase, it's demonstrated as myocardial infarction and ischemia-reperfusion injury, while in the chronic stage, the ischemic heart is mainly characterised by adverse myocardial remodelling. Although interventions such as thrombolysis and percutaneous coronary intervention could reduce the death risk of these patients, the underlying cellular and molecular mechanisms need more exploration. Mitochondria are crucial to maintain the physiological function of the heart. During IHD, mitochondrial dysfunction results in the pathogenesis of ischemic heart disease. Ischemia drives mitochondrial damage not only due to energy deprivation, but also to other aspects such as mitochondrial dynamics, mitochondria-related inflammation, etc. Given the critical roles of mitochondrial quality control in the pathological process of ischemic heart disease, in this review, we will summarise the efforts in targeting mitochondria (such as mitophagy, mtROS, and mitochondria-related inflammation) on IHD. In addition, we will briefly revisit the emerging therapeutic targets in this field.


Cells ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 214 ◽  
Author(s):  
Andrew R. Kulek ◽  
Anthony Anzell ◽  
Joseph M. Wider ◽  
Thomas H. Sanderson ◽  
Karin Przyklenk

The current standard of care for acute myocardial infarction or ‘heart attack’ is timely restoration of blood flow to the ischemic region of the heart. While reperfusion is essential for the salvage of ischemic myocardium, re-introduction of blood flow paradoxically kills (rather than rescues) a population of previously ischemic cardiomyocytes—a phenomenon referred to as ‘lethal myocardial ischemia-reperfusion (IR) injury’. There is long-standing and exhaustive evidence that mitochondria are at the nexus of lethal IR injury. However, during the past decade, the paradigm of mitochondria as mediators of IR-induced cardiomyocyte death has been expanded to include the highly orchestrated process of mitochondrial quality control. Our aims in this review are to: (1) briefly summarize the current understanding of the pathogenesis of IR injury, and (2) incorporating landmark data from a broad spectrum of models (including immortalized cells, primary cardiomyocytes and intact hearts), provide a critical discussion of the emerging concept that mitochondrial dynamics and mitophagy (the components of mitochondrial quality control) may contribute to the pathogenesis of cardiomyocyte death in the setting of ischemia-reperfusion.


2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Anthony R. Anzell ◽  
Garrett M. Fogo ◽  
Zoya Gurm ◽  
Sarita Raghunayakula ◽  
Joseph M. Wider ◽  
...  

AbstractMitochondrial dynamics and mitophagy are constitutive and complex systems that ensure a healthy mitochondrial network through the segregation and subsequent degradation of damaged mitochondria. Disruption of these systems can lead to mitochondrial dysfunction and has been established as a central mechanism of ischemia/reperfusion (I/R) injury. Emerging evidence suggests that mitochondrial dynamics and mitophagy are integrated systems; however, the role of this relationship in the context of I/R injury remains unclear. To investigate this concept, we utilized primary cortical neurons isolated from the novel dual-reporter mitochondrial quality control knockin mice (C57BL/6-Gt(ROSA)26Sortm1(CAG-mCherry/GFP)Ganl/J) with conditional knockout (KO) of Drp1 to investigate changes in mitochondrial dynamics and mitophagic flux during in vitro I/R injury. Mitochondrial dynamics was quantitatively measured in an unbiased manner using a machine learning mitochondrial morphology classification system, which consisted of four different classifications: network, unbranched, swollen, and punctate. Evaluation of mitochondrial morphology and mitophagic flux in primary neurons exposed to oxygen-glucose deprivation (OGD) and reoxygenation (OGD/R) revealed extensive mitochondrial fragmentation and swelling, together with a significant upregulation in mitophagic flux. Furthermore, the primary morphology of mitochondria undergoing mitophagy was classified as punctate. Colocalization using immunofluorescence as well as western blot analysis revealed that the PINK1/Parkin pathway of mitophagy was activated following OGD/R. Conditional KO of Drp1 prevented mitochondrial fragmentation and swelling following OGD/R but did not alter mitophagic flux. These data provide novel evidence that Drp1 plays a causal role in the progression of I/R injury, but mitophagy does not require Drp1-mediated mitochondrial fission.


2021 ◽  
Vol 22 (2) ◽  
pp. 677
Author(s):  
Tausif Altamash ◽  
Wesam Ahmed ◽  
Saad Rasool ◽  
Kabir H. Biswas

Intracellular ionic strength regulates myriad cellular processes that are fundamental to cellular survival and proliferation, including protein activity, aggregation, phase separation, and cell volume. It could be altered by changes in the activity of cellular signaling pathways, such as those that impact the activity of membrane-localized ion channels or by alterations in the microenvironmental osmolarity. Therefore, there is a demand for the development of sensitive tools for real-time monitoring of intracellular ionic strength. Here, we developed a bioluminescence-based intracellular ionic strength sensing strategy using the Nano Luciferase (NanoLuc) protein that has gained tremendous utility due to its high, long-lived bioluminescence output and thermal stability. Biochemical experiments using a recombinantly purified protein showed that NanoLuc bioluminescence is dependent on the ionic strength of the reaction buffer for a wide range of ionic strength conditions. Importantly, the decrease in the NanoLuc activity observed at higher ionic strengths could be reversed by decreasing the ionic strength of the reaction, thus making it suitable for sensing intracellular ionic strength alterations. Finally, we used an mNeonGreen–NanoLuc fusion protein to successfully monitor ionic strength alterations in a ratiometric manner through independent fluorescence and bioluminescence measurements in cell lysates and live cells. We envisage that the biosensing strategy developed here for detecting alterations in intracellular ionic strength will be applicable in a wide range of experiments, including high throughput cellular signaling, ion channel functional genomics, and drug discovery.


Author(s):  
Roberta A. Gottlieb ◽  
Honit Piplani ◽  
Jon Sin ◽  
Savannah Sawaged ◽  
Syed M. Hamid ◽  
...  

AbstractMitochondrial quality control depends upon selective elimination of damaged mitochondria, replacement by mitochondrial biogenesis, redistribution of mitochondrial components across the network by fusion, and segregation of damaged mitochondria by fission prior to mitophagy. In this review, we focus on mitochondrial dynamics (fusion/fission), mitophagy, and other mechanisms supporting mitochondrial quality control including maintenance of mtDNA and the mitochondrial unfolded protein response, particularly in the context of the heart.


2021 ◽  
Vol 22 (6) ◽  
pp. 2881
Author(s):  
Clara Lefranc ◽  
Malou Friederich-Persson ◽  
Fabienne Foufelle ◽  
Aurélie Nguyen Dinh Cat ◽  
Frédéric Jaisser

Mineralocorticoid receptor (MR) expression is increased in the adipose tissue (AT) of obese patients and animals. We previously demonstrated that adipocyte-MR overexpression in mice (Adipo-MROE mice) is associated with metabolic alterations. Moreover, we showed that MR regulates mitochondrial dysfunction and cellular senescence in the visceral AT of obese db/db mice. Our hypothesis is that adipocyte-MR overactivation triggers mitochondrial dysfunction and cellular senescence, through increased mitochondrial oxidative stress (OS). Using the Adipo-MROE mice with conditional adipocyte-MR expression, we evaluated the specific effects of adipocyte-MR on global and mitochondrial OS, as well as on OS-induced damage. Mitochondrial function was assessed by high throughput respirometry. Molecular mechanisms were probed in AT focusing on mitochondrial quality control and senescence markers. Adipo-MROE mice exhibited increased mitochondrial OS and altered mitochondrial respiration, associated with reduced biogenesis and increased fission. This was associated with OS-induced DNA-damage and AT premature senescence. In conclusion, targeted adipocyte-MR overexpression leads to an imbalance in mitochondrial dynamics and regeneration, to mitochondrial dysfunction and to ageing in visceral AT. These data bring new insights into the MR-dependent AT dysfunction in obesity.


2015 ◽  
Vol 309 (3) ◽  
pp. E275-E282 ◽  
Author(s):  
Yanqing Zhang ◽  
Jianli Zhao ◽  
Rui Li ◽  
Wayne Bond Lau ◽  
Yue-Xing Yuan ◽  
...  

Adiponectin (APN) is a cardioprotective molecule. Its reduction in diabetes exacerbates myocardial ischemia/reperfusion (MI/R) injury. Although APN administration in animals attenuates MI/R injury, multiple factors limit its clinical application. The current study investigated whether AdipoRon, the first orally active molecule that binds APN receptors, may protect the heart against MI/R injury, and if so, to delineate the involved mechanisms. Wild-type (WT), APN knockout (APN-KO), and cardiomyocyte specific-AMPK dominant negative (AMPK-DN) mice were treated with vehicle or AdipoRon (50 mg/kg, 10 min prior to MI) and subjected to MI/R (30 min/3–24 h). Compared with vehicle, oral administration of AdipoRon to WT mice significantly improved cardiac function and attenuated postischemic cardiomyocyte apoptosis, determined by DNA ladder formation, TUNEL staining, and caspase-3 activation (all P < 0.01). MI/R-induced apoptotic cell death was significantly enhanced in mice deficient in either APN (APN-KO) or AMPK (AMPK-DN). In APN-KO mice, AdipoRon attenuated MI/R injury to the same degree as observed in WT mice. In AMPK-DN mice, AdipoRon's antiapoptotic action was partially inhibited but not lost. Finally, AdipoRon significantly attenuated postischemic oxidative stress, as evidenced by reduced NADPH oxidase expression and superoxide production. Collectively, these results demonstrate for the first time that AdipoRon, an orally active APN receptor activator, effectively attenuated postischemic cardiac injury, supporting APN receptor agonists as a promising novel therapeutic approach treating cardiovascular complications caused by obesity-related disorders such as type 2 diabetes.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Sweeka Meshram ◽  
Ganga Agnihotri ◽  
Sushma Gupta

The renewable energy systems (RESs) are an attractive option to electrify the community as they are environment friendly, free of cost, and all-pervading. The efficiency of these energy systems is very low and can be improved by integrating them in parallel. In this paper, hydro (7.5 kW) and solar systems (10 kW) are taken as RESs and connected with the utility grid. Due to the intermittent nature of both the hydro and photovoltaic energy sources, utility grid is connected to the system for ensuring the continuous power flow. The hydro power generation system uses the self excited induction generator (SEIG) and converters. The AC/DC/AC converter is used as interface to connect the hydro turbine to the utility grid to adjust the generated voltage to the utility grid voltage. The solar generation system is the combination of PV array, boost converter, and solar inverter. The control of both the hydro and solar power plants is provided through the constant current controller. The analysis has been done to verify the existence of the proposed system. Results demonstrate that the proposed system is able to be put into service and can feed the community.


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