Anti-KRT18 monoclonal antibody, clone D-15 [FITC]

Purpose: The lacrimal gland secretes tear fluids that protect the ocular surface epithelium, and its dysfunction leads to dry eye disease (DED). The functional restoration of the lacrimal gland by engraftment of a bioengineered lacrimal gland using lacrimal gland germ epithelial cells has been proposed to cure DED in mice. Here, we investigate the expression profile of cytokeratins in the lacrimal gland germ epithelium to clarify their unique characteristics. Methods: We performed quantitative polymerase chain reaction (Q-PCR) and immunohistochemistry (IHC) analysis to clarify the expression profile of cytokeratin in the lacrimal gland germ epithelium. Results: The mRNA expression of keratin (KRT) 5, KRT8, KRT14, KRT15, and KRT18 in the lacrimal gland germ epithelium was increased compared with that in mouse embryonic stem cells and the lacrimal gland germ mesenchyme, as analyzed by Q-PCR. The expression level of KRT15 increased in the transition from stem cells to lacrimal gland germ epithelium, then decreased as the lacrimal gland matured. IHC revealed that the expression set of these cytokeratins in the lacrimal gland germ epithelium was different from that in the adult lacrimal gland. The expression of KRT15 was observed in the lacrimal gland germ epithelium, and it segmentalized into some of the basal cells in the intercanulated duct in mature gland. Conclusion: We determined the expression profile of cytokeratins in the lacrimal gland epithelium, and identified KRT15 as a candidate unique cellular marker for the lacrimal gland germ epithelium. (C) 2015 Elsevier Ltd. All rights reserved.

Are human trophectoderm (TE) cells committed or still able to develop into inner cell mass (ICM) cells? Human full blastocyst TE cells still have the capacity to develop into ICM cells expressing the pluripotency marker NANOG, thus they are not yet committed. Human Day 5 full blastocyst TE cells express the pluripotency markers POU5F1, SOX2 and SALL4 as well as the TE markers HLA-G and KRT18 but not yet CDX2, therefore their developmental direction may not yet be definite. The potency of human blastocyst TE cells was investigated by determining their in vitro capacity to develop into a blastocyst with ICM cells expressing NANOG; TE cells were isolated either by aspiration under visual control or after labeling with fluorescent 594-wheat germ agglutinin. Further on, aspirated TE cells were also labeled with fluorescent PKH67 and repositioned in the center of the original embryo. Human preimplantation embryos were used for research after obtaining informed consent from IVF patients. The experiments were approved by the Local Ethical Committee and the oBelgian Federal Committee on medical and scientific research on embryos in vitro'. Outer cells were isolated and reaggregated by micromanipulation. Reconstituted embryos were analyzed by immunocytochemistry. Isolated and reaggregated TE cells from full human blastocysts are able to develop into blastocysts with ICM cells expressing the pluripotency marker NANOG. Moreover, the majority of the isolated TE cells which were repositioned in the center of the embryo do not sort back to their original position but integrate within the ICM and start to express NANOG. Owing to legal and ethical restrictions, manipulated human embryos cannot be transferred into the uterus to determine their totipotent capacity. The definitive demonstration that embryos reconstructed with TE cells are a source of pluripotent cells is to obtain human embryonic stem cell olike' line(s), which will allow full characterization of the cells. Our finding has important implications in reproductive medicine and stem cell biology because TE cells have a greater developmental potential than assumed previously. Scientific Research FoundationuFlanders (FWO-Vlaanderen) and Research Council (OZR) of the Vrije Universiteit Brussel. None of the authors declared a conflict of interest.