Potential localization of putative stem/progenitor cells in human bulbar conjunctival epithelium.
Although the conjunctival fornix appears to contain the greatest proportion of stem cells, it is likely that pockets of conjunctival epithelial stem cells may also exist throughout the conjunctival epithelium. This study was to investigate the potential localization of putative stem/progenitor cells in the human bulbar conjunctival epithelium by evaluating 6 keratins and 13 molecules that have been previously proposed stem cell associated or differentiation markers. We found that cornea specific cytokeratin (CK) 3 was not expressed by the bulbar conjunctival epithelial cells. In contrast, CK4 and CK7 were expressed by the superficial cells of bulbar conjunctival epithelium. CK14 and CK15 were confined to the basal cell layer. CK19 was strongly expressed by all layers of the bulbar conjunctival epithelium. The expression patterns of molecular markers in the basal cells of human bulbar conjunctival epithelium were found to be similar to the corneal epithelium. Basal conjunctival epithelial cells strongly expressed stem cell associated markers, including ABCG2, p63, nerve growth factor (NGF) with its receptors tyrosine kinase receptor A (TrkA) and neurotrophin low-affinity receptor p75NTR, glial cell-derived neurotrophic factor (GDNF) with its receptor GDNF family receptor alpha 1 (GFRalpha-1), integrin beta1, alpha-enolase, and epidermal growth factor receptor (EGFR). The differentiation associated markers nestin, E-cadherin and involucrin were not expressed by these cells. These findings indicate that the basal cells of bulbar conjunctival epithelium shares a similar expression pattern of stem cell associated markers to the corneal epithelium, but has a unique pattern of differentiation associated cytokeratin expression.
Qi
Hong
H
Ocular Surface Center, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas.
Zheng
Xiaofen
X
Yuan
Xiaoyong
X
Pflugfelder
Stephen C
SC
Li
De-Quan
DQ
D015415:Biomarkers / Q000378:metabolism*; D002454:Cell Differentiation / Q000502:physiology; D003228:Conjunctiva / Q000166:cytology* / Q000378:metabolism; D004847:Epithelial Cells / Q000166:cytology* / Q000378:metabolism*; D019573:Epithelium, Corneal / Q000378:metabolism; D006801:Humans; D007633:Keratins / Q000235:genetics / Q000378:metabolism; D016850:Limbus Corneae / Q000166:cytology / Q000378:metabolism; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism; D014018:Tissue Distribution
D015415:Biomarkers; D020033:Protein Isoforms; D007633:Keratins
Subcell Biochem. 1998;31:71-104
9932490
Trends Cell Biol. 1994 Sep;4(9):321-6
14731469
Invest Ophthalmol Vis Sci. 1995 Jan;36(1):236-46
7822151
BMC Neurosci. 2004 Oct 28;5:41
15511288
Mol Vis. 2007 Oct 16;13:1934-41
17982417
J Cereb Blood Flow Metab. 2000 Oct;20(10):1393-408
11043902
Lab Invest. 2000 Nov;80(11):1701-10
11092530
J Pathol. 2004 Nov;204(4):355-66
15495218
Invest Ophthalmol Vis Sci. 1996 Mar;37(4):523-33
8595952
Microsc Res Tech. 1999 May 15-Jun 1;45(4-5):292-302
10383122
Arch Ophthalmol. 2007 Apr;125(4):523-32
17420373
Clin Sci (Lond). 2006 Feb;110(2):167-73
16411893
Stem Cells. 2004;22(3):355-66
15153612
J Cell Biol. 1981 Sep;90(3):738-42
6895226
Invest Ophthalmol Vis Sci. 2007 Apr;48(4):1543-51
17389483
Exp Eye Res. 2005 Sep;81(3):247-64
16051216
J Biomed Sci. 2004 Sep-Oct;11(5):641-51
15316140
Ocul Surf. 2003 Jan;1(1):5-19
17075625
J Cell Biol. 1999 May 17;145(4):769-82
10330405
J Cell Biol. 1986 Jul;103(1):49-62
2424919
Invest Ophthalmol Vis Sci. 1988 Jun;29(6):969-75
3372169
Biol Reprod. 2005 Nov;73(5):1011-6
16014811
Differentiation. 1992 Oct;51(2):137-48
1282112
Invest Ophthalmol Vis Sci. 1993 Apr;34(5):1814-28
8473120
Clin Exp Ophthalmol. 2001 Jun;29(3):138-42
11446453
Ann N Y Acad Sci. 2005 Dec;1061:94-9
16467260
Histochemistry. 1991;95(6):613-20
1713203
Cell. 1982 Sep;30(2):361-72
6183000
Invest Ophthalmol Vis Sci. 2001 Sep;42(10):2270-82
11527940
Annu Rev Biochem. 2003;72:609-42
12676795
Invest Ophthalmol Vis Sci. 2002 Apr;43(4):987-94
11923238
J Cell Biol. 1981 Sep;90(3):732-7
6895225
Invest Ophthalmol Vis Sci. 1997 Jan;38(1):142-52
9008639
Neurosci Biobehav Rev. 1994 Spring;18(1):143-59
8170621
Invest Ophthalmol Vis Sci. 1998 Jun;39(7):1272-5
9620090
Cell. 1982 Nov;31(1):11-24
6186379
Stem Cells. 2007 Mar;25(3):628-38
17110619
Invest Ophthalmol Vis Sci. 2006 Nov;47(11):4780-6
17065488
J Invest Dermatol. 1993 Jun;100(6):729-34
7684423
Prog Retin Eye Res. 2002 Mar;21(2):241-62
12062536
Ocul Surf. 2005 Jan;3(1):15-26
17131002
Oncogene. 2003 Jun 26;22(26):4017-26
12821936
Adv Anat Embryol Cell Biol. 1992;126:1-82
1381138