Author
CHI, ZHI-HONG - CHINA MEDICAL UNIVERSITY | |
REN, HAO - CHINA MEDICAL UNIVERSITY | |
WANG, XIN - CHINA MEDICAL UNIVERSITY | |
RONG, MING - CHINA MEDICAL UNIVERSITY | |
Huang, Liping | |
WANG, ZHAN-YOU - CHINA MEDICAL UNIVERSITY |
Submitted to: Trade Journal Publication
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 4/1/2008 Publication Date: 7/1/2008 Citation: Chi, Z., Ren, H., Wang, X., Rong, M., Huang, L., Wang, Z. 2008. The cellular and subcellular localization of zinc transporter 7 in the mouse spinal cord. Histology and Histopathology Cellular and Molecular Biology, Vol.23:781-787 Interpretive Summary: The present work addresses the location of the zinc transporter 7 (ZNT7, SLC30a7) protein in the cell and the distribution of zinc ions (Zn2+) in the mouse spinal cord. Our results indicated that neurons containing ZNT7 protein were widely distributed in the Rexed’s laminae, a system comprising of ten layers of grey matter (I-X), in all spinal segments examined. The ependyma cell, which is involved in the production of cerebrospinal fluid, in the central canal and the glia cell, which provides support and nutrition for the neurons, in the white matter were also shown ZNT7-positive. The ZNT7 immunoreactivity was mainly detected in the perinuclear regions of ZNT7- positive cells in the spinal gray matter. For ependyma cells, the immunoreactivity of ZNT7 was detected in the cytoplasm near the lumina of the central canal. Ultrastructural localization showed that ZNT7 was predominately present in the membrane of the Golgi stacks, an organelle that processes and packages the macromolecules such as proteins and lipids that are synthesized by the cell. The double immunofluorescence studies confirmed this result. Other intracellular organelles including the endoplasmic reticulum, mitochondria and lysosomes were not stained positive for ZNT7. The chelatable (free and loosely bound) Zn2+ ions in the spinal cord were found predominantly in the terminals of the neuron rather than the cell body in the gray matter. However, overlapping distribution of chelatable Zn2+ ions and ZNT7 was found in the ependyma cells. The present study supports the notion that ZNT7 may function to supply zinc ions to the newly synthesized metalloproteins in the secretory pathway of the spinal neuron and the ependyma cell. Technical Abstract: The present work addresses the cellular and subcellular localization of the zinc transporter 7 (ZNT7, SLC30a7) protein and the distribution of zinc ions (Zn2+) in the mouse spinal cord. Our results indicated that the ZNT7 immunoreactive neurons were widely distributed in the Rexed’s laminae of the gray matter in all spinal segments examined. The ependyma cells of the central canal and glia cells in the white matter were also shown ZNT7-positive. The ZNT7 immunoreactivity was mainly detected in the perinuclear regions of ZNT7- positive cells in the spinal gray matter. For ependyma cells, the immunoreactivity of ZNT7 was detected in the cytoplasm near the lumina of the central canal. Ultrastructural localization showed that ZNT7 was predominately present in the membrane of the Golgi stacks. The double immunofluorescence studies confirmed this result. Other intracellular organelles including the endoplasmic reticulum, mitochondria and lysosomes were devoid of ZNT7-immunostaining. The chelatable Zn2+ ions in the spinal cord were found predominantly in the terminals of the neuron rather than the cell body in the gray matter. However, overlapping distribution of chelatable Zn2+ ions and ZNT7 was found in the ependyma cells. The present study supports the notion that ZNT7 may function to supply zinc ions to the newly synthesized metalloproteins in the secretory pathway of the spinal neuron and the ependyma cell. |