title: Human forniceal region is the stem cell-rich zone of the conjunctival epithelium.
abstract: The anterior surface of the eye is covered by several physically contiguous but histologically distinguishable epithelia overlying the cornea, limbus, bulbar conjunctiva, fornix conjunctiva, and palpebral conjunctiva. The self-renewing nature of the conjunctival epithelia makes their long-term survival ultimately dependent on small populations of stem cells. Hence, the objective of this study was to investigate the expression of the stem cell genes Sox2, OCT4, NANOG, Rex1, NES, and ABCG2 in cultured human conjunctival epithelium from different conjunctival zones, namely, the bulbar, palpebral and fornix zones. Three samples were taken from patients with primary pterygium and cataract (age range 56-66 years) who presented to our eye clinic at the UKM Medical Centre. The eye was examined with slit lamp to ensure there was no underlying ocular surface diseases and glaucoma. Conjunctival tissue was taken from patients who underwent a standard cataract or pterygium operation as a primary procedure. Tissues were digested, cultured, and propagated until an adequate number of cells was obtained. Total RNA was extracted and subjected to expression analysis of conjunctival epithelium genes (KRT4, KRT13, KRT19) and stem cell genes (Sox2, OCT4, NANOG, Rex1, NES, ABCG2) by reverse transcriptase-PCR and 2% agarose gel electrophoresis. The expression of Sox2, OCT4, and NANOG genes were detected in the fornical cells, while bulbar cells only expressed Sox2 and palpebral cells only expressed OCT4. Based on these results, the human forniceal region expresses a higher number of stem cell genes than the palpebral and bulbar conjunctiva.
authors: Department of Ophthalmology, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latif, 56000, Kuala Lumpur, Malaysia.
authors: Mohd Hairul Nizam
authors: MH
authors: Harun
authors: Siti Norzalehawati
authors: SN
authors: Sepian
authors: Kien-Hui
authors: KH
authors: Chua
authors: Abd Rahman
authors: AR
authors: Ropilah
authors: Norzana
authors: N
authors: Abd Ghafar
authors: Jemaima
authors: J
authors: Che-Hamzah
authors: Ruszymah
authors: R
authors: Bt Hj Idrus
authors: Faridah Hanom
authors: FH
authors: Annuar
mesh_terms: D000368:Aged; D002478:Cells, Cultured; D003228:Conjunctiva / Q000166:cytology*; D004848:Epithelium; D015870:Gene Expression; D018398:Homeodomain Proteins; D006801:Humans; D008875:Middle Aged; D000071317:Nanog Homeobox Protein; D050814:Octamer Transcription Factor-3; D020133:Reverse Transcriptase Polymerase Chain Reaction; D055748:SOXB1 Transcription Factors; D013234:Stem Cells
chemical_list: D018398:Homeodomain Proteins; C486780:NANOG protein, human; D000071317:Nanog Homeobox Protein; D050814:Octamer Transcription Factor-3; C494173:POU5F1 protein, human; C527782:SOX2 protein, human; D055748:SOXB1 Transcription Factors