Luminal and Glandular Epithelial Cells from the Porcine Endometrium maintain Cell Type-Specific Marker Gene Expression in Air–Liquid Interface Culture

Abstract

Two different types of epithelial cells constitute the inner surface of the endometrium. While luminal epithelial cells line the uterine cavity and build the embryo-maternal contact zone, glandular epithelial cells form tubular glands reaching deeply into the endometrial stroma. To facilitate investigations considering the functional and molecular differences between the two populations of epithelial cells and their contribution to reproductive processes, we aimed at establishing differentiated in vitro models of both the luminal and the glandular epithelium of the porcine endometrium using an air–liquid interface (ALI) approach. We first tested if porcine luminal endometrium epithelial cells (PEEC-L) reproducibly form differentiated epithelial monolayers under ALI conditions by monitoring the morphology and the trans-epithelial electrical resistance (TEER). Subsequently, luminal (PEEC-L) and glandular epithelial cells (PEEC-G) were consecutively isolated from the endometrium of the uterine horn. Both cell types were characterized by marker gene expression analysis immediately after isolation. Cells were separately grown at the ALI and assessed by means of histomorphometry, TEER, and marker gene expression after 3 weeks of culture. PEEC-L and PEEC-G formed polarized monolayers of differentiated epithelial cells with a moderate TEER and in vivo-like morphology at the ALI. They exhibited distinct patterns of functional and cell type-specific marker gene expression after isolation and largely maintained these patterns during the culture period. The here presented cell culture procedure for PEEC-L and -G offers new opportunities to study the impact of embryonic signals, endocrine effectors, and reproductive toxins on both porcine endometrial epithelial cell types under standardized in vitro conditions. Graphical Abstract Created with BioRender.com.

Bioengineering approaches for the endometrial research and application

“…The endometrium is a precisely controlled tissue that comprises a simple columnar epithelium overlying a multicellular stroma ( Fig. 1 ) [ 11 ]. The epithelial layer mainly consists of luminal and glandular epithelial cells that line the intact uterine cavity and cover the pits extending into the myometrium [ 12 ].…”

Ovarian sex steroid and epithelial control of immune responses in the uterus and oviduct: human and animal models

“…The present review centered on the examination of the UECs and OECs. Endometrial epithelial cells are divided into two types: luminal and glandular epithelial cells [ 19 ]. The luminal epithelial cells are the crucial component of the uterine cavity, functioning as a site for embryo-maternal contact.…”

“…The luminal epithelial cells are the crucial component of the uterine cavity, functioning as a site for embryo-maternal contact. The glandular epithelial cells form tubular glands [ 19 ]. These two types of epithelial cells have distinct molecular signatures and are controlled hormonally by the menstrual cycle [ 19 ].…”

“…The glandular epithelial cells form tubular glands [ 19 ]. These two types of epithelial cells have distinct molecular signatures and are controlled hormonally by the menstrual cycle [ 19 ]. For example, the α9β1 integrin exhibits robust expression in the luminal epithelium of the endometrium during all phases of the menstrual cycle in humans [ 20 ].…”