Age-related expressions of p63 and other keratinocyte stem cell markers in rat cornea
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Efficient and Scalable Directed Differentiation of Clinically Compatible Corneal Limbal Epithelial Stem Cells from Human Pluripotent Stem Cells
Published on: October 24, 2018
Yi-Jen Hsueh1, Der-Yuan Wang, Chien-Chia Cheng
1Department of Physiology, College of Medicine, Chang Gung University, Taoyuan, Taiwan.
Insights
This study reveals unique postnatal expression patterns of p63 in rat corneas, differing from humans. P63 marks corneal keratinocyte stem cells and transient amplifying cells in rats.
Area of Science:
- Ophthalmology
- Stem Cell Biology
- Corneal Research
Background:
- Corneal epithelial stem cells are crucial for maintaining corneal transparency and regeneration.
- Identifying reliable stem cell markers is essential for understanding corneal biology and disease.
- p63 is a known marker for epithelial stem cells, but its expression in the cornea varies across species.
Purpose of the Study:
- To investigate the postnatal expression patterns of p63 and other keratinocyte stem cell markers in the rat cornea.
- To identify markers that accurately characterize corneal keratinocyte stem cells in rats.
- To compare p63 expression in rat corneas with that observed in humans.
Main Methods:
- Immunohistochemical staining was employed to examine p63 expression in rat corneas at different postnatal stages.
- Sensitive staining methods were utilized to detect lower levels of p63 expression.
- Co-expression analysis with other markers like beta-catenin, K14, PCNA, and K3 was performed.
Main Results:
- Rat corneal p63 expression exhibits unique age-dependent patterns, differing significantly from human expression.
- p63 expression changes from positive in central, peripheral, and limbal regions to negative in the central cornea with age.
- A more sensitive staining method revealed persistent, albeit lower, p63 expression in the limbus.
- The basal layer of the rat limbal epithelium contains slow-cycling cells positive for beta-catenin and K14, but negative for PCNA and K3.
- p63 is expressed in both stem cells and young transient amplifying cells in the rat cornea, with higher levels in the latter.
Conclusions:
- p63 expression patterns in the rat cornea are distinct from those in humans.
- p63 serves as a marker for both corneal stem cells and transient amplifying cells in rats.
- The basal limbal epithelium harbors slow-cycling cells, indicative of stem cell populations.
- These findings contribute to a better understanding of corneal stem cell biology in rats, with implications for comparative studies.
Abstract:
In this study, we examined the postnatal expression patterns of p63 and other keratinocyte stem cell markers in the rat cornea in an attempt to determine the markers that best represent characteristics of corneal keratinocyte stem cells. We show that the expression of p63 in the rat cornea is unique and differs from that observed in humans. It changes with age, from central cornea-positive, peripheral cornea-positive, and limbus-positive, to central cornea-positive, peripheral cornea-positive, and limbus-negative, and finally to central cornea-negative, peripheral cornea-positive, and limbus-negative, as examined by immunohistochemical staining. However, when a more sensitive staining method was used, the limbus was also shown to be positive for p63, indicating a lower level of expression than that of the peripheral cornea. The basal layer of the rat limbal epithelium is the site where beta-catenin+, K14+, PCNA-, and K3- cells reside. This cell layer is also the site where slow-cycling cells are located. In contrast with observations made in humans, our results clearly indicate that p63 is expressed in stem cells and young transient amplifying cells of the rat cornea, with higher levels of expression in the latter.
