TY - JOUR
T1 - Melanocytes in the corneal limbus interact with K19-positive basal epithelial cells
AU - Higa, Kazunari
AU - Shimmura, Shigeto
AU - Miyashita, Hideyuki
AU - Shimazaki, Jun
AU - Tsubota, Kazuo
N1 - Funding Information:
The authors thank Ms Mifuyu Oshima and Ms Hiroe Fujikawa for their technical assistance, and the staff of the Cornea Center Eye Bank for administrative support. This work was supported by a grant from the Advanced and Innovational Research Program in Life Sciences of the Japanese Ministry of Education, Culture, Sports, Science and Technology, Japan.
PY - 2005/8
Y1 - 2005/8
N2 - The human corneal limbus is identified by the distinct features of the palisades of Vogt (POV), which contain pigment granules that are aligned with the microplicae of the epithelium. Although it is presumed that pigments are produced by melanocytes, the characterization of melanocytes in the limbus has not been clearly documented. We examined human limbal tissues by whole mounts and serial histological sections to localize epithelial cells containing melanin granules. Most of the pigmented cells observed by immunohistochemistry were K19 (+) cells in the basal limbal epithelium. A superimposed image revealed that melanin granules were oriented towards the apex of each K19 (+) cell, acting as a pigmented cap facing the ocular surface. Melanocytes were identified by MART1, an antigen specific to melanocyte-lineage cells. Melanocytes were shown to exist as sporadic cells with dendritic processes that extend to surrounding epithelial cells. Melanocytes were also found in light-pigmented donor tissue when visualized by the tyrosinase assay using the enzyme substrate DOPA. Since tyrosinase activity was not found in epithelial cells, the production of melanin is exclusively the role of melanocytes that comprised 5·3± 2·7% of the total cells in cytospin samples (N=3). Melanocytes and K19 (+) epithelial cells may form a functional network similar to the melanin unit of the skin.
AB - The human corneal limbus is identified by the distinct features of the palisades of Vogt (POV), which contain pigment granules that are aligned with the microplicae of the epithelium. Although it is presumed that pigments are produced by melanocytes, the characterization of melanocytes in the limbus has not been clearly documented. We examined human limbal tissues by whole mounts and serial histological sections to localize epithelial cells containing melanin granules. Most of the pigmented cells observed by immunohistochemistry were K19 (+) cells in the basal limbal epithelium. A superimposed image revealed that melanin granules were oriented towards the apex of each K19 (+) cell, acting as a pigmented cap facing the ocular surface. Melanocytes were identified by MART1, an antigen specific to melanocyte-lineage cells. Melanocytes were shown to exist as sporadic cells with dendritic processes that extend to surrounding epithelial cells. Melanocytes were also found in light-pigmented donor tissue when visualized by the tyrosinase assay using the enzyme substrate DOPA. Since tyrosinase activity was not found in epithelial cells, the production of melanin is exclusively the role of melanocytes that comprised 5·3± 2·7% of the total cells in cytospin samples (N=3). Melanocytes and K19 (+) epithelial cells may form a functional network similar to the melanin unit of the skin.
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U2 - 10.1016/j.exer.2005.01.023
DO - 10.1016/j.exer.2005.01.023
M3 - Article
C2 - 16080916
AN - SCOPUS:23144444289
SN - 0014-4835
VL - 81
SP - 218
EP - 223
JO - Experimental Eye Research
JF - Experimental Eye Research
IS - 2
ER -