|
|||||
|
|
ATP is stored in lysosomes of greater epithelial ridge supporting cells in newborn rat cochleae |
|
| Authors: | Jiarui Chen Shule Hou Jun Yang |
| Institution: | 1. Department of Otorhinolaryngology-Head & Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
Department of Otorhinolaryngology-Head & Neck Surgery, Shanghai Children's Hospital, Shanghai Jiaotong University, Shanghai, China Ear Institute, Shanghai Jiaotong University School of Medicine, Shanghai, China Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China Jiarui Chen and Shule Hou contributed equally to this work.;2. Department of Otorhinolaryngology-Head & Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China Ear Institute, Shanghai Jiaotong University School of Medicine, Shanghai, China Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China Jiarui Chen and Shule Hou contributed equally to this work.;3. Department of Otorhinolaryngology-Head & Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China |
| Abstract: | Adenosine triphosphate (ATP), which plays a crucial role in both developing and mature cochleae, is released from greater epithelial ridge (GER) supporting cells of the rat cochlea, but the organelles in which ATP is stored have not yet been identified. Thus, we studied the organelles involved in ATP storage and suggest that lysosomes provide this function. GER supporting cells of newborn rats were isolated, purified, and cultured, and labeled vesicles within the supporting cells were identified via confocal microscopy and transmission electron microscopy (TEM). ATP release from GER supporting cells after glycyl-L -phenylalanine-β-naphthylamide (GPN) treatment was measured. The specifically labeled organelles observed by confocal microscopy and TEM were lysosomes, and GPN treatment enhanced ATP luminescence in the extracellular fluid of the supporting cells. The release of ATP from supporting cells was affected by changes in intra- and extracellular Ca2+ concentrations. In addition, changes in the intracellular Ca2+ caused by inhibiting the phospholipase signaling pathway affected the release of ATP from supporting cells. We demonstrated that ATP is stored in the lysosomes of GER supporting cells within newborn rat cochleae and that ATP release from GER supporting cells may be Ca2+-dependent. |
| Keywords: | ATP cochlea greater epithelial ridge lysosomes supporting cells |