title: ATP-containing vesicles in stria vascular marginal cell cytoplasms in neonatal rat cochlea are lysosomes.
abstract: We confirmed that ATP is released from cochlear marginal cells in the stria vascular but the cell organelle in which ATP stores was not identified until now. Thus, we studied the ATP-containing cell organelles and suggest that these are lysosomes. Primary cultures of marginal cells of Sprague-Dawley rats aged 1-3 days was established. Vesicles within marginal cells stained with markers were identified under confocal laser scanning microscope and transmission electron microscope (TEM). Then ATP release from marginal cells was measured after glycyl-L-phenylalanine-ß- naphthylamide (GPN) treatment using a bioluminescent assay. Quinacrine-stained granules within marginal cells were labeled with LysoTracker, a lysosome tracer, and lysosomal-associated membrane protein 1(LAMP1), but not labeled with the mitochondrial tracer MitoTracker. Furthermore, LysoTracker-labelled puncta showed accumulation of Mant-ATP, an ATP analog. Treatment with 200 μM GPN quenched fluorescently labeled puncta after incubation with LysoTracker or quinacrine, but not MitoTracker. Quinacrine-labeled organelles observed by TEM were lysosomes, and an average 27.7 percent increase in ATP luminescence was observed in marginal cells extracellular fluid after GPN treatment. ATP-containing vesicles in cochlear marginal cells of the stria vascular from neonatal rats are likely lysosomes. ATP release from marginal cells may be via Ca(2+)-dependent lysosomal exocytosis.
authors: Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.|Shanghai Jiaotong University School of Medicine Ear Institute, Shanghai, China.|Shanghai Key Laboratory of Translational Medicine on Ear and Nose diseases, Shanghai, China.|Department of Otorhinolaryngology, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
authors: Jun
authors: J
authors: Liu
authors: Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.|Shanghai Jiaotong University School of Medicine Ear Institute, Shanghai, China.|Shanghai Key Laboratory of Translational Medicine on Ear and Nose diseases, Shanghai, China.
authors: Wenjing
authors: W
authors: Liu
authors: Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.|Shanghai Jiaotong University School of Medicine Ear Institute, Shanghai, China.|Shanghai Key Laboratory of Translational Medicine on Ear and Nose diseases, Shanghai, China.
authors: Jun
authors: J
authors: Yang
mesh_terms: D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000378:metabolism* / Q000494:pharmacology; D000588:Amines / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D002118:Calcium / Q000378:metabolism; D003593:Cytoplasm / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D022162:Cytoplasmic Vesicles / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D004151:Dipeptides / Q000494:pharmacology; D005089:Exocytosis; D015870:Gene Expression; D008163:Luminescent Measurements; D051907:Lysosomal Membrane Proteins / Q000235:genetics / Q000378:metabolism; D008247:Lysosomes / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D009930:Organic Chemicals / Q000737:chemistry / Q000378:metabolism; D061251:Primary Cell Culture; D011796:Quinacrine / Q000737:chemistry / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013194:Staining and Labeling; D013316:Stria Vascularis / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D062367:ortho-Aminobenzoates / Q000494:pharmacology; D052118:Lysosomal-Associated Membrane Protein 1
chemical_list: D000255:Adenosine Triphosphate; D000588:Amines; D002118:Calcium; D004151:Dipeptides; D051907:Lysosomal Membrane Proteins; D009930:Organic Chemicals; D011796:Quinacrine; D062367:ortho-Aminobenzoates; C489117:Lamp1 protein, rat; D052118:Lysosomal-Associated Membrane Protein 1; C493330:Red DND-99; C107472:red dye CMXRos; C041865:glycylphenylalanine 2-naphthylamide; C045473:3'-O-(N-methylanthraniloyl) ATP