Gene delivery of Tim44 reduces mitochondrial superoxide production and ameliorates neointimal proliferation of injured carotid artery in diabetic rats.
Hyperglycemia induces the production of reactive oxygen species (ROS) from mitochondria, which is closely related to diabetic vascular complications. Mammalian translocase of inner mitochondrial membrane (Tim)44 was identified by upregulation in streptozotocin (STZ)-induced diabetic mouse kidneys; Tim44 functions as a membrane anchor of mtHsp70 to TIM23 complex and is involved in the import of preproteins with mitochondria-targeted presequence into mitochondrial matrix. The process is dependent on inner membrane potential (Delta psi) and ATP hydrolysis on ATPase domain of mtHsp70. Here, we show that the gene delivery of Tim44 using pcDNA3.1 vector (pcDNA3.1/TIM44) into the balloon injury model of STZ-induced diabetic rats ameliorated neointimal proliferation. ROS production, inflammatory responses, and cell proliferation in injured carotid artery were diminished by delivery of pcDNA3.1/TIM44. In vitro experiments using human aortic smooth muscle cells (HASMCs) revealed that the gene delivery of Tim44 normalized high-glucose-induced enhanced ROS production and increased ATP production, alterations in inner membrane potential, and cell proliferation. Transfection of siRNA and pcDNA3.1/TIM44 using HASMC culture clarified that import of antioxidative enzymes such as superoxide dismutase and glutathione peroxidase was facilitated by Tim44. Tim44 and its related molecules in mitochondrial import machinery complex are novel targets in the therapeutic interventions for diabetes and its vascular complications.
Matsuoka
Takashi
T
Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine and Dentistry, Okayama 700-8558, Japan.
Wada
Jun
J
Hashimoto
Izumi
I
Zhang
Yanling
Y
Eguchi
Jun
J
Ogawa
Norio
N
Shikata
Kenichi
K
Kanwar
Yashpal S
YS
Makino
Hirofumi
H
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001011:Aorta; D020212:Carotid Artery Injuries / Q000473:pathology*; D002352:Carrier Proteins / Q000235:genetics*; D002404:Catheterization; D002455:Cell Division; D002478:Cells, Cultured; D016207:Cytokines / Q000235:genetics; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism / Q000473:pathology*; D015870:Gene Expression; D005822:Genetic Vectors; D005947:Glucose / Q000494:pharmacology; D005980:Glutathione Reductase / Q000378:metabolism; D006801:Humans; D006965:Hyperplasia; D008297:Male; D008564:Membrane Potentials; D008565:Membrane Proteins / Q000235:genetics*; D008928:Mitochondria / Q000378:metabolism*; D033681:Mitochondrial Membrane Transport Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D024101:Mitochondrial Proteins / Q000235:genetics*; D009131:Muscle, Smooth, Vascular / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism*; D014162:Transfection; D017539:Tunica Intima / Q000473:pathology*; D019010:Vascular Cell Adhesion Molecule-1 / Q000235:genetics
D002352:Carrier Proteins; D016207:Cytokines; D008565:Membrane Proteins; D033681:Mitochondrial Membrane Transport Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D024101:Mitochondrial Proteins; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; C489672:Timm44 protein, mouse; D019010:Vascular Cell Adhesion Molecule-1; D013481:Superoxides; D000255:Adenosine Triphosphate; D013482:Superoxide Dismutase; D005980:Glutathione Reductase; D005947:Glucose