scholarly journals Tafazzin Mutation Affecting Cardiolipin Leads to Increased Mitochondrial Superoxide Anions and Mitophagy Inhibition in Barth Syndrome

Cells ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 2333 ◽  
Author(s):  
Patrice Petit ◽  
Hector Ardilla-Osorio ◽  
Lucile Penalvia ◽  
Nathan E. Rainey
Keyword(s):  
Oxidative Phosphorylation ◽  
Mitochondrial Dysfunction ◽  
Molecular Mechanisms ◽  
Cell Model ◽  
Premature Death ◽  
Barth Syndrome ◽  
Mitochondrial Homeostasis ◽  
Mitochondrial Superoxide ◽  
Promising Treatment ◽  
Tafazzin Gene

Tafazzin is a phospholipid transacylase that catalyzes the remodeling of cardiolipin, a mitochondrial phospholipid required for oxidative phosphorylation. Mutations of the tafazzin gene cause Barth syndrome, which is characterized by mitochondrial dysfunction and dilated cardiomyopathy, leading to premature death. However, the molecular mechanisms underlying the cause of mitochondrial dysfunction in Barth syndrome remain poorly understood. We again highlight the fact that the tafazzin deficiency is also linked to defective oxidative phosphorylation associated with oxidative stress. All the mitochondrial events are positioned in a context where mitophagy is a key element in mitochondrial quality control. Here, we investigated the role of tafazzin in mitochondrial homeostasis dysregulation and mitophagy alteration. Using a HeLa cell model of tafazzin deficiency, we show that dysregulation of tafazzin in HeLa cells induces alteration of mitophagy. Our findings provide some additional insights into mitochondrial dysfunction associated with Barth syndrome, but also show that mitophagy inhibition is concomitant with apoptosis dysfunction through the inability of abnormal mitochondrial cardiolipin to assume its role in cytoplasmic signal transduction. Our work raises hope that pharmacological manipulation of the mitophagic pathway together with mitochondrially targeted antioxidants may provide new insights leading to promising treatment for these highly lethal conditions.

scholarly journals Exogenous Alpha-Synuclein Evoked Parkin Downregulation Promotes Mitochondrial Dysfunction in Neuronal Cells. Implications for Parkinson’s Disease Pathology

2021 ◽  
Vol 13 ◽  
Author(s):  
Anna Wilkaniec ◽  
Anna M. Lenkiewicz ◽  
Lidia Babiec ◽  
Emilia Murawska ◽  
Henryk M. Jęśko ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Fission ◽  
Alpha Synuclein ◽  
Post Translational Modifications ◽  
Protein Levels ◽  
Mitochondrial Homeostasis ◽  
Mitochondrial Superoxide ◽  
Mitochondrial Biosynthesis

Aberrant secretion and accumulation of α-synuclein (α-Syn) as well as the loss of parkin function are associated with the pathogenesis of Parkinson’s disease (PD). Our previous study suggested a functional interaction between those two proteins, showing that the extracellular α-Syn evoked post-translational modifications of parkin, leading to its autoubiquitination and degradation. While parkin plays an important role in mitochondrial biogenesis and turnover, including mitochondrial fission/fusion as well as mitophagy, the involvement of parkin deregulation in α-Syn-induced mitochondrial damage is largely unknown. In the present study, we demonstrated that treatment with exogenous α-Syn triggers mitochondrial dysfunction, reflected by the depolarization of the mitochondrial membrane, elevated synthesis of the mitochondrial superoxide anion, and a decrease in cellular ATP level. At the same time, we observed a protective effect of parkin overexpression on α-Syn-induced mitochondrial dysfunction. α-Syn-dependent disturbances of mitophagy were also shown to be directly related to reduced parkin levels in mitochondria and decreased ubiquitination of mitochondrial proteins. Also, α-Syn impaired mitochondrial biosynthesis due to the parkin-dependent reduction of PGC-1α protein levels. Finally, loss of parkin function as a result of α-Syn treatment induced an overall breakdown of mitochondrial homeostasis that led to the accumulation of abnormal mitochondria. These findings may thus provide the first compelling evidence for the direct association of α-Syn-mediated parkin depletion to impaired mitochondrial function in PD. We suggest that improvement of parkin function may serve as a novel therapeutic strategy to prevent mitochondrial impairment and neurodegeneration in PD (thereby slowing the progression of the disease).

Melatonin As a Modulator of Degenerative and Regenerative Signaling Pathways in Injured Retinal Ganglion Cells

2019 ◽  
Vol 25 (28) ◽  
pp. 3057-3073 ◽  
Author(s):  
Kobra B. Juybari ◽  
Azam Hosseinzadeh ◽  
Habib Ghaznavi ◽  
Mahboobeh Kamali ◽  
Ahad Sedaghat ◽  
...  
Keyword(s):  
Optic Nerve ◽  
Mitochondrial Dysfunction ◽  
Signaling Pathways ◽  
Retinal Ganglion Cells ◽  
Molecular Mechanisms ◽  
Nitrosative Stress ◽  
Ganglion Cells ◽  
Axon Growth ◽  
Nerve Fibers ◽  
Retinal Ganglion

Optic neuropathies refer to the dysfunction or degeneration of optic nerve fibers caused by any reasons including ischemia, inflammation, trauma, tumor, mitochondrial dysfunction, toxins, nutritional deficiency, inheritance, etc. Post-mitotic CNS neurons, including retinal ganglion cells (RGCs) intrinsically have a limited capacity for axon growth after either trauma or disease, leading to irreversible vision loss. In recent years, an increasing number of laboratory evidence has evaluated optic nerve injuries, focusing on molecular signaling pathways involved in RGC death. Trophic factor deprivation (TFD), inflammation, oxidative stress, mitochondrial dysfunction, glutamate-induced excitotoxicity, ischemia, hypoxia, etc. have been recognized as important molecular mechanisms leading to RGC apoptosis. Understanding these obstacles provides a better view to find out new strategies against retinal cell damage. Melatonin, as a wide-spectrum antioxidant and powerful freeradical scavenger, has the ability to protect RGCs or other cells against a variety of deleterious conditions such as oxidative/nitrosative stress, hypoxia/ischemia, inflammatory processes, and apoptosis. In this review, we primarily highlight the molecular regenerative and degenerative mechanisms involved in RGC survival/death and then summarize the possible protective effects of melatonin in the process of RGC death in some ocular diseases including optic neuropathies. Based on the information provided in this review, melatonin may act as a promising agent to reduce RGC death in various retinal pathologic conditions.

scholarly journals The TGFβ Family in Human Placental Development at the Fetal-Maternal Interface

Biomolecules ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 453
Author(s):  
Susana M. Chuva de Sousa Lopes ◽  
Marta S. Alexdottir ◽  
Gudrun Valdimarsdottir
Keyword(s):  
Stem Cell ◽  
Transforming Growth Factor Beta ◽  
Molecular Mechanisms ◽  
Transforming Growth Factor ◽  
Cell Model ◽  
Embryonic Stem ◽  
Model Systems ◽  
Special Focus ◽  
Placental Development

Emerging data suggest that a trophoblast stem cell (TSC) population exists in the early human placenta. However, in vitro stem cell culture models are still in development and it remains under debate how well they reflect primary trophoblast (TB) cells. The absence of robust protocols to generate TSCs from humans has resulted in limited knowledge of the molecular mechanisms that regulate human placental development and TB lineage specification when compared to other human embryonic stem cells (hESCs). As placentation in mouse and human differ considerably, it is only with the development of human-based disease models using TSCs that we will be able to understand the various diseases caused by abnormal placentation in humans, such as preeclampsia. In this review, we summarize the knowledge on normal human placental development, the placental disease preeclampsia, and current stem cell model systems used to mimic TB differentiation. A special focus is given to the transforming growth factor-beta (TGFβ) family as it has been shown that the TGFβ family has an important role in human placental development and disease.

scholarly journals Imaging mass cytometry reveals generalised deficiency in OXPHOS complexes in Parkinson’s disease

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Chun Chen ◽  
David McDonald ◽  
Alasdair Blain ◽  
Ashwin Sachdeva ◽  
Laura Bone ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Oxidative Phosphorylation ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Disease ◽  
Dopaminergic Neurons ◽  
Neuronal Response ◽  
Proteomic Profiling ◽  
Mass Cytometry ◽  
And Control

AbstractHere we report the application of a mass spectrometry-based technology, imaging mass cytometry, to perform in-depth proteomic profiling of mitochondrial complexes in single neurons, using metal-conjugated antibodies to label post-mortem human midbrain sections. Mitochondrial dysfunction, particularly deficiency in complex I has previously been associated with the degeneration of dopaminergic neurons in Parkinson’s disease. To further our understanding of the nature of this dysfunction, and to identify Parkinson’s disease specific changes, we validated a panel of antibodies targeting subunits of all five mitochondrial oxidative phosphorylation complexes in dopaminergic neurons from Parkinson’s disease, mitochondrial disease, and control cases. Detailed analysis of the expression profile of these proteins, highlighted heterogeneity between individuals. There is a widespread decrease in expression of all complexes in Parkinson’s neurons, although more severe in mitochondrial disease neurons, however, the combination of affected complexes varies between the two groups. We also provide evidence of a potential neuronal response to mitochondrial dysfunction through a compensatory increase in mitochondrial mass. This study highlights the use of imaging mass cytometry in the assessment and analysis of expression of oxidative phosphorylation proteins, revealing the complexity of deficiencies of these proteins within individual neurons which may contribute to and drive neurodegeneration in Parkinson’s disease.

scholarly journals Molecular Mechanisms behind Inherited Neurodegeneration of the Optic Nerve

Biomolecules ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 496
Author(s):  
Alessandra Maresca ◽  
Valerio Carelli
Keyword(s):  
Optic Nerve ◽  
Mitochondrial Dysfunction ◽  
Molecular Mechanisms ◽  
Ganglion Cells ◽  
Mitochondrial Dynamics ◽  
Unmet Need ◽  
Deep Understanding ◽  
Genetic Landscape ◽  
Innovative Therapies ◽  
Energy Dependent

Inherited neurodegeneration of the optic nerve is a paradigm in neurology, as many forms of isolated or syndromic optic atrophy are encountered in clinical practice. The retinal ganglion cells originate the axons that form the optic nerve. They are particularly vulnerable to mitochondrial dysfunction, as they present a peculiar cellular architecture, with axons that are not myelinated for a long intra-retinal segment, thus, very energy dependent. The genetic landscape of causative mutations and genes greatly enlarged in the last decade, pointing to common pathways. These mostly imply mitochondrial dysfunction, which leads to a similar outcome in terms of neurodegeneration. We here critically review these pathways, which include (1) complex I-related oxidative phosphorylation (OXPHOS) dysfunction, (2) mitochondrial dynamics, and (3) endoplasmic reticulum-mitochondrial inter-organellar crosstalk. These major pathogenic mechanisms are in turn interconnected and represent the target for therapeutic strategies. Thus, their deep understanding is the basis to set and test new effective therapies, an urgent unmet need for these patients. New tools are now available to capture all interlinked mechanistic intricacies for the pathogenesis of optic nerve neurodegeneration, casting hope for innovative therapies to be rapidly transferred into the clinic and effectively cure inherited optic neuropathies.

scholarly journals Adipocyte-Mineralocorticoid Receptor Alters Mitochondrial Quality Control Leading to Mitochondrial Dysfunction and Senescence of Visceral Adipose Tissue

2021 ◽  
Vol 22 (6) ◽  
pp. 2881
Author(s):  
Clara Lefranc ◽  
Malou Friederich-Persson ◽  
Fabienne Foufelle ◽  
Aurélie Nguyen Dinh Cat ◽  
Frédéric Jaisser
Keyword(s):  
Quality Control ◽  
Adipose Tissue ◽  
Mitochondrial Dysfunction ◽  
Cellular Senescence ◽  
Mineralocorticoid Receptor ◽  
Molecular Mechanisms ◽  
Mitochondrial Dynamics ◽  
Mitochondrial Quality Control ◽  
Mitochondrial Oxidative Stress ◽  
Specific Effects

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.

scholarly journals Epilepsy in Mitochondrial Diseases—Current State of Knowledge on Aetiology and Treatment

Children ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 532
Author(s):  
Dorota Wesół-Kucharska ◽  
Dariusz Rokicki ◽  
Aleksandra Jezela-Stanek
Keyword(s):  
Oxidative Phosphorylation ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Disease ◽  
Clinical Picture ◽  
Poor Prognosis ◽  
Treatment Options ◽  
Mitochondrial Diseases ◽  
Energy Deficit ◽  
Atp Production ◽  
Current State

Mitochondrial diseases are a heterogeneous group of diseases resulting from energy deficit and reduced adenosine triphosphate (ATP) production due to impaired oxidative phosphorylation. The manifestation of mitochondrial disease is usually multi-organ. Epilepsy is one of the most common manifestations of diseases resulting from mitochondrial dysfunction, especially in children. The onset of epilepsy is associated with poor prognosis, while its treatment is very challenging, which further adversely affects the course of these disorders. Fortunately, our knowledge of mitochondrial diseases is still growing, which gives hope for patients to improve their condition in the future. The paper presents the pathophysiology, clinical picture and treatment options for epilepsy in patients with mitochondrial disease.

microRNA-4458 Regulates Insulin Resistance in Hepatic Cells by Targeting the Insulin-Like Growth Factor 1 Receptor

2021 ◽  
Vol 11 (9) ◽  
pp. 1812-1817
Author(s):  
Jingjing Zhou ◽  
Wenjuan Zhu ◽  
Zheng Mao ◽  
Zhen Li ◽  
Xiaoqin Li ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Mrna Expression ◽  
Glucose Uptake ◽  
Hepg2 Cell ◽  
Molecular Mechanisms ◽  
Cell Model ◽  
Serum Insulin ◽  
Luciferase Reporter ◽  
Control Group ◽  
Hepatic Cells

Background: The objective of the research was to investigate the roles of miR-4458 in the regulation of insulin resistance in hepatic cells and to explore the underlying molecular mechanisms. Methods: The blood samples were collected from the T2D patients and the health controls, and the liver tissues were collected from the DM and control rats. The relationship between IGF1R and miR-4458 was predicted by TargetScan and verified by the dual luciferase reporter gene system. qRT-PCR was used to measure the mRNA expression of miR-4458, IGF1R, G6Pase and PEPCK. The protein expression of IGF1R, p-AKT and AKT were measured by Western blot analysis. The rat insulin ELISA Kit and glucose Uptake Colorimteric Assay Kit were used to determine the level of serum insulin and the glucose uptake. Results: miR-4458 was high expressed in T2D patients. We predicted and verified that IGF1R was a direct target of miR-4458, and the mRNA expression of IGF1R was reduced in type 2 diabetes patients. We established the diabetes model (DM) and IR HepG2 cell model, and found that the blood glucose and serum insulin levels were significantly elevated in the DM group. miR-4458 expression was up-regulated, while the expression of IGF1R and p-AKT, and p-AKT/AKT ratio were reduced in the DM group and IR HepG2 cell model. miR-4458 inhibitor and IGF1R-siRNA significantly decreased the expression of miR-4458 and IGF1R respectively. In comparison with IR+inhibitor control group, miR-4458 inhibitor increased 2-DG6P content, IGF1R expression, p-AKT expression and p-AKT/AKT ratio, reduced the expression of G6Pase and PEPCK, and all the effects were reversed by down-regulating IGF1R. Conclusion: miR-4458 regulated the insulin resistance in hepatic cells by regulating the IGF1R/PI3K/AKT signal pathway, which will be a potential target for the treatment of diabetes.

Abstract P233: Diabetic Cardiomyopathy is Reversed by Increased Mitochondrial Bioenergetics Due to PGC-1α Activation by EET Treatment of Obese Mice

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Jian Cao ◽  
John A McClung ◽  
Shailendra P Singh ◽  
Lars Bellner ◽  
Maayan Waldman ◽  
...  
Keyword(s):  
Heart Failure ◽  
Insulin Resistance ◽  
Oxidative Phosphorylation ◽  
Mitochondrial Dysfunction ◽  
Diabetic Cardiomyopathy ◽  
Cardiac Fibrosis ◽  
Systolic Function ◽  
Control Group ◽  
Protein Markers ◽  
Obesity And Diabetes

Introduction: Obesity and diabetes are associated with progressive cardiac fibrosis that, sequentially, results in diastolic dysfunction, reduced contractility, and ultimately heart failure. Contributing factors include hyperglycemia, insulin resistance, mitochondrial dysfunction, and a reduction in AMPK signaling. PGC-1α activates mitochondrial biogenesis and oxidative phosphorylation and is decreased in patients with diabetes mellitus (DM). We hypothesize that an epoxyeicosatrienoic acids (EETs) agonist (EET-A) will increase PGC-1α levels in a db mouse model of DM attenuate cardiomyopathy, and prevent heart failure. Methods: Db mice (4-wks), were allowed to acclimatize for 16-wks and were then divided into 3 treatment groups for an additional 16 wks: A) control, B) EET-A 1.5mg/100g BW 2 weeks and C) EET-A-Ln-PGC-1α shRNA. Ln-PGC-1α shRNA suppressed PGC-1α protein in heart tissue by 40-50%. Oxygen consumption (VO 2 ), and blood glucose was determined. Heart tissues were harvested to measure PGC-1α, HO-1, pAMPK, PGC-1α, echocardiographic fractional shortening, mitochondrial oxidative phosphorylation (OXPHOS) and mitofusion protein markers. Results: All mice developed heart failure by the end of 16 weeks and were characterized by a decrease in myocardial contractility, an increase in insulin resistance and blood pressure, decreased VO 2 , the appearance of mitochondria dysfunction and a decrease in AMPK and downstream PGC-1α signaling. Mice treated with EET-A demonstrated an increase in PGC-1α levels, improved mitochondrial function and oxidative phosphorylation (p<0.01 vs control), increased NO bioavailability (p<0.05 vs control), and normalization of glucose metabolism, insulin levels, VO 2 and LV systolic function (p<0.05 vs control). All of these findings were suppressed by PGC-1α inhibition which was accompanied by the onset of even more severe LV dysfunction than in the control group. Conclusion: Increased EET levels result in activation of PGC-1α-HO-1 which reverses diabetes induced insulin resistance, mitochondrial dysfunction, and cardiomyopathy. EET may have potential as a powerful agent for therapeutic application in the treatment of diabetic cardiomyopathy.

scholarly journals Salvia officinalis L. extract and its new food antioxidant formulations induce apoptosis through mitochondrial/ caspase pathway in leukemia L1210 cells

2014 ◽  
Vol 7 (3) ◽  
pp. 146-153 ◽  
Author(s):  
Soňa Jantová ◽  
Roman Hudec ◽  
Stanislav Sekretár ◽  
Juraj Kučerák ◽  
Martina Melušová
Keyword(s):  
Molecular Mechanisms ◽  
Cell Model ◽  
Ethanolic Extract ◽  
Salvia Officinalis ◽  
Protective Properties ◽  
Cellular Effects ◽  
L1210 Cells ◽  
Salvia Officinalis L ◽  
Induced Apoptosis ◽  
Herbal Species

ABSTRACT Salvia officinalis, L. (Lamiaceae) is one of the most widespread herbal species used in the area of human health and in the foodprocessing industry. Salvia and its extracts are known to be a rich source of antioxidants. As shown previously, the crude ethanolic extract of salvia (SE) exerts lower anti-oxidative properties in lard compared to the new salvia food formulations No. 1 (SF1; 32% of SE + 68% of the emulsifier Dimodan S-T) and No. 2 (SF2; 32% of SE + 68% of the emulsifier Topcithin 50). The aim of the present study was to investigate and compare the effects of the SE and its food formulations SF1 and SF2 on the toxicity and/or proliferation of L1210 leukemia cells. We found that SE and both SF1 and SF2 demonstrated different concentration- and time-dependent cytotoxic/antiproliferative cellular effects already within the first 24 h of the treatment. However, SE was nearly 10 times more effective than the new salvia food formulations SF1 and SF2. We investigated partially also the molecular mechanisms lying behind the action of SE, SF1 and SF2 induced apoptosis in our cell model. We found an apparent involvement of the mitochondrial/caspase-dependent pathway in the described processes. Nevertheless, further investigation is needed before salvia extract and its new antioxidant formulations can be included among the potential food antioxidants with protective properties against cancer.

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