Table 1.
Summary of human endometrial epithelial cell studies included.
| Author, year | Sample type and size | Compare with infertile sample | Cycle stage | Relevant results |
| Heneweer et al., 2002 (36) | Cell line: n = 6-15/group | n/a | RL95-2 cell line (MS) | F-actin increases in the apex of cells upon spheroid adhesion, this actin remodeling most likely regulated by RhoA |
| Montazeri et al., 2015 (37) | Cell line: n = 3 | n/a | RL95-2 cell line (MS) | TLR-3 activation led to reduced spheroid adhesion, actin polymerization and CD98 and β3-integrin expression |
| Martin et al., 2000 (38) | Primary cells: unknown; Cell lines: unknown |
no | Endometrial tissue (all L); RL95-2 cell line (MS); Hec-1A cell line (P) |
RL95-2 cells have an adhesion rate of 81% and are associated with reduced ezrin and absent moesin expression compared to HEC-1A cells (46%). Primary cells have an intermediate adhesion rate (67%) |
| Heng et al., 2011 (39) | Tissue: n ≥ 48; Cell line: unknown |
Yes | Endometrial tissue (P n => 10, MS n = 25); Hec-1A cell line (P) |
Reduced PC6, which cleaves the scaffolding protein EBP50, affects the interaction of EBP50 with ezrin, EBP50/ezrin cellular localization and cytoskeleton-membrane connections |
| Demir et al., 2002 (40) | Tissue: n = 18 | No | Endometrial tissue (ES n = 4); Decidua (ED n = 6, LD n = 8) |
Morphological and molecular changes in the LE and GE play a role in cellular defense and limiting trophoblastic invasion during early pregnancy compared to ES endometrium |
| Bentin-Ley et al., 2000 (41) | Primary cells: unknown | No | Endometrial tissue (LH+5 to LH+7) | Blastocysts adhere and invade the endometrium via intrusive penetration simultaneously, leading to syncytium formation |
| Kabir-Salmani et al., 2005 (42) | Tissue: n = 23 | No | Endometrial tissue (EL n = 5, ML n = 10, LL n = 8) | LIF expression increased in uterodomes during the MS phase, and was co-localized with markers of exocytosis |
| Alameda et al., 2007 (43) | Normal and pathological tissue: n = 98 (n = 79 pathological) | No | Endometrial tissue: Normal (P n = 11, S n = 8); 44 endometrial hyperplasia and 35 endometrial adenocarcinomas | MUC-4 is detected in the P GE (36.3%) but is down-regulated in the S (12.5%) wherein MUC-2 is up-regulated (37.5%) |
| Whitby et al., 2018 (44) | Tissue: n ≥ 10/group; Primary cells (SCs): n = 5; Cell line: n = 4 |
no | Endometrial tissue (P n = 10, ES n = 10, MS n = 10, LS n = 10); SCs (P or ES n = 5); ECC-1 cell line (LE) |
TER (as a measure for polarity) was reduced in ECC-1 cells treated with E2 and P4. Stardust, atypical PKC, Crumbs and Scribble are reduced in the LE and Scribble increased in SCs in S versus P endometrium. Scribble KD in ECC-1 cells and SCs enhanced spheroid adhesion and down-regulated decidualization, respectively |
| Greening et al., 2016 (45) | Tissue: n = 5/group; Primary cells: n = 6; Cell line: n = 3 |
no | Endometrial tissue (P, S, and T1); EECs: unknown; ECC-1 cell line (LE) |
157 cellular proteins are altered with progesterone, and 193 are further altered with hCG. 123 proteins are altered in the secretome with progesterone, and 43 are further altered by hCG |
| Van Sinderen et al., 2017 (46) | Tissue: n ≥ 4/group; Flushings: n = 14; Cell line: n = 3/group |
yes | Endometrial tissue (ES or MS); Uterine lavage (S); RL-95 cell line (MS) |
Infertility is associated with increased soluble DLL1, which reduces epithelial adhesive capacity via HES1 mRNA down-regulation, and increased ADAM17 expression in the LE, which cleaves DLL1 to form its soluble form. Soluble DLL1 may inhibit Notch signaling |
n/a, not applicable; L, luteal phase; P, proliferative; S, secretory; T1, first trimester; LE, luminal epithelium; GE, glandular epithelium; ES, early-secretory; MS, mid-secretory; LS, late-secretory; EL, early luteal; ML, mid-luteal; LL, late-luteal; ED, early decidua; LD, late decidua; EECs, endometrial epithelial cells; SCs, stromal cells; LH, luteinizing hormone; TLR-3, toll-like receptor-3; CD98, 4F2 cell-surface antigen heavy chain; RhoA, Ras homolog family member A; hCG, human chorionic gonadotrophin; MUC, mucin; PC6, proprotein convertase 5/6; EBP50, ezrin-radixin-moesin binding phosphoprotein 50; LIF, leukemia inhibitory factor; DLL1, delta-like ligand 1; HES1, hairy and enhancer of split-1; ADAM17, “a disintegrin and metalloprotease” protease-17; TER, trans-epithelial resistance; IHC, immunohistochemistry; E2, estrogen; P4, progesterone; atypical PKC, atypical protein kinase C; KD, knock-down. Cycle stage for cell lines is representative.