Downregulation of Dynamin-Related Protein 1 Contributes to Impaired Autophagic Flux and Angiogenic Function in Senescent Endothelial Cells

Objective—Recent studies have shown that altered mitochondrial dynamics impairs the function in senescent endothelial cells (ECs). However, the underlying molecular mechanism remains to be elucidated. Herein, we investigated the role and underlying mechanism of mitochondrial fission protein dynamin-related protein 1 (DRP1) in vascular aging. Approach and Results—We found that DRP1 expression is decreased in senescent ECs, accompanied with long interconnected mitochondria and impaired angiogenic function. In addition, there was marked increase of autophagosomes but not of autolysosomes (assessed as punctate dual fluorescent mCherry-GFP (green fluorescent protein) tandem-tagged light chain 3 expression) in senescent ECs, indicating impaired autophagic flux. DRP1 knockdown or pharmacological inhibition in young ECs resulted in elongated mitochondria, suppressed autophagic flux, premature senescence, and impaired angiogenic function. In contrast, adenoviral-mediated overexpression of DRP1 in senescent ECs restored autophagic flux and improved angiogenic function. EC senescence was associated with the increase of mitochondrial reactive oxygen species and antioxidant N-acetyl-cysteine restored autophagosome clearance and improved angiogenic function. Consistently, en face staining of old rat thoracic aorta revealed a decrease of DRP1 expression and increase of autophagosomes accumulation. Furthermore, in vivo knockdown of Drp1 in common carotid arteries significantly impaired the autophagosome clearance. Importantly, downregulation of Drp1 directly abrogated microvessels outgrowth from ex vivo aortic rings. Conclusions—These results suggest that loss of DRP1 during senescence exacerbates ECs dysfunction by increasing mitochondrial reactive oxygen species and subsequently inhibiting autophagic flux.

[1]  M. Grootaert,et al.  Autophagy in Vascular Disease , 2015, Circulation research.

[2]  M. Abdellatif,et al.  Endogenous Drp1 Mediates Mitochondrial Autophagy and Protects the Heart Against Energy Stress , 2015, Circulation research.

[3]  Zhisheng Jiang,et al.  Autophagy Regulates Vascular Endothelial Cell eNOS and ET-1 Expression Induced by Laminar Shear Stress in an Ex Vivo Perfused System , 2014, Annals of Biomedical Engineering.

[4]  C. K. Chong,et al.  Disturbed Flow Promotes Endothelial Senescence via a p53-Dependent Pathway , 2014, Arteriosclerosis, thrombosis, and vascular biology.

[5]  In Hye Lee,et al.  Autophagy regulates endothelial cell processing, maturation and secretion of von Willebrand factor , 2013, Nature Medicine.

[6]  A. Bratić,et al.  The role of mitochondria in aging. , 2013, The Journal of clinical investigation.

[7]  K. Dharmashankar,et al.  Adverse Alterations in Mitochondrial Function Contribute to Type 2 Diabetes Mellitus–Related Endothelial Dysfunction in Humans , 2012, Arteriosclerosis, thrombosis, and vascular biology.

[8]  A. Thorburn,et al.  Translational evidence that impaired autophagy contributes to arterial ageing , 2012, The Journal of physiology.

[9]  H. Sesaki,et al.  Mitochondrial division prevents neurodegeneration , 2012, Autophagy.

[10]  Xianhua Wang,et al.  Central Role of Mitofusin 2 in Autophagosome-Lysosome Fusion in Cardiomyocytes* , 2012, The Journal of Biological Chemistry.

[11]  P. Reddy,et al.  Mitochondrial division ensures the survival of postmitotic neurons by suppressing oxidative damage , 2012, The Journal of cell biology.

[12]  D. Klionsky,et al.  Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition) , 2012, Autophagy.

[13]  Robert Clarke,et al.  Guidelines for the use and interpretation of assays for monitoring autophagy , 2012 .

[14]  William A Dunn,et al.  Autophagy suppresses age-dependent ischemia and reperfusion injury in livers of mice. , 2011, Gastroenterology.

[15]  Youngil Lee,et al.  Mitochondrial autophagy by Bnip3 involves Drp1-mediated mitochondrial fission and recruitment of Parkin in cardiac myocytes. , 2011, American journal of physiology. Heart and circulatory physiology.

[16]  D. Rubinsztein,et al.  Autophagy and Aging , 2011, Cell.

[17]  M. Burnett,et al.  Aging Causes Collateral Rarefaction and Increased Severity of Ischemic Injury in Multiple Tissues , 2011, Arteriosclerosis, thrombosis, and vascular biology.

[18]  O. Shirihai,et al.  Altered Mitochondrial Dynamics Contributes to Endothelial Dysfunction in Diabetes Mellitus , 2011, Circulation.

[19]  Benedikt Westermann,et al.  Mitochondrial fusion and fission in cell life and death , 2010, Nature Reviews Molecular Cell Biology.

[20]  C. Leeuwenburgh,et al.  New insights into the role of mitochondria in aging: mitochondrial dynamics and more , 2010, Journal of Cell Science.

[21]  R. D. de Boer,et al.  Glucagon-Like Peptide 1 Prevents Reactive Oxygen Species–Induced Endothelial Cell Senescence Through the Activation of Protein Kinase A , 2010, Arteriosclerosis, thrombosis, and vascular biology.

[22]  J. Bereiter-Hahn,et al.  Decreased expression of Drp1 and Fis1 mediates mitochondrial elongation in senescent cells and enhances resistance to oxidative stress through PINK1 , 2010, Journal of Cell Science.

[23]  N. Mizushima,et al.  Methods in Mammalian Autophagy Research , 2010, Cell.

[24]  Marc Liesa,et al.  Mitochondrial dynamics in mammalian health and disease. , 2009, Physiological reviews.

[25]  R. Henning,et al.  Bradykinin Protects Against Oxidative Stress–Induced Endothelial Cell Senescence , 2009, Hypertension.

[26]  R. Youle,et al.  Parkin is recruited selectively to impaired mitochondria and promotes their autophagy , 2008, The Journal of cell biology.

[27]  O. Shirihai,et al.  Mitochondrial fusion, fission and autophagy as a quality control axis: the bioenergetic view. , 2008, Biochimica et biophysica acta.

[28]  R. Youle,et al.  Mitochondrial Fission and Fusion Mediators, hFis1 and OPA1, Modulate Cellular Senescence* , 2007, Journal of Biological Chemistry.

[29]  T. Noda,et al.  Dissection of the Autophagosome Maturation Process by a Novel Reporter Protein, Tandem Fluorescent-Tagged LC3 , 2007, Autophagy.

[30]  H. Waterham,et al.  A lethal defect of mitochondrial and peroxisomal fission. , 2007, The New England journal of medicine.

[31]  T. Rabelink,et al.  Endothelial function and dysfunction: testing and clinical relevance. , 2007, Circulation.

[32]  I. Komuro,et al.  Vascular Cell Senescence: Contribution to Atherosclerosis , 2007, Circulation research.

[33]  D. Chan.  Mitochondrial fusion and fission in mammals. , 2006, Annual review of cell and developmental biology.

[34]  D. Kurz,et al.  Cellular senescence in vivo: Its relevance in ageing and cardiovascular disease , 2005, Experimental Gerontology.

[35]  T. Zglinicki,et al.  Mitochondria, telomeres and cell senescence , 2005, Experimental Gerontology.

[36]  R. Weindruch,et al.  Ageing, oxidative stress, and mitochondrial uncoupling. , 2004, Acta physiologica Scandinavica.

[37]  D. Hall,et al.  Autophagy Genes Are Essential for Dauer Development and Life-Span Extension in C. elegans , 2003, Science.

[38]  Daniel Levy,et al.  Arterial and cardiac aging: major shareholders in cardiovascular disease enterprises: Part I: aging arteries: a "set up" for vascular disease. , 2003, Circulation.

[39]  K. Irani,et al.  Constitutive Activation of rac 1 Results in Mitochondrial Oxidative Stress and Induces Premature Endothelial Cell Senescence , 2003, Arteriosclerosis, thrombosis, and vascular biology.

[40]  J. Grosgeorge,et al.  Nuclear gene OPA1, encoding a mitochondrial dynamin-related protein, is mutated in dominant optic atrophy , 2000, Nature Genetics.

[41]  V. Dulic,et al.  Differential Roles for Cyclin-Dependent Kinase Inhibitors p21 and p16 in the Mechanisms of Senescence and Differentiation in Human Fibroblasts , 1999, Molecular and Cellular Biology.

[42]  James M. Roberts,et al.  Inhibitors of mammalian G1 cyclin-dependent kinases. , 1995, Genes & development.

[43]  B. Ames,et al.  Oxidative damage and mitochondrial decay in aging. , 1994, Proceedings of the National Academy of Sciences of the United States of America.

[44]  J. Erusalimsky.  Vascular endothelial senescence: from mechanisms to pathophysiology. , 2009, Journal of applied physiology.

[45]  J. Erusalimsky.  From Mechanisms to Pathophysiology , 2008 .

[46]  T. Nyström,et al.  Reducing mitochondrial fission results in increased life span and fitness of two fungal ageing models , 2007, Nature Cell Biology.