Table 1.
New subsets of placental trophoblasts during early pregnancy identified by single cell RNA seq.
| CTB | EVT | |
|---|---|---|
| Subsets | Proliferative (Replenishment of the CBT pool) | RRM2+ (cell cycle and division) The proximal end of cell column |
| Non-proliferative | RRM2low/− The distal end of cell column |
|
| Receptors | EGFR | HLA-C |
| NRP2 | HLA-E | |
| HGFR | HLA-G | |
| ACKR2 | ||
| CXCR6 | ||
| Functions | Proliferation | Immunomodulation |
| Differentiation | Invasion |
There are three CTB subsets present in the first trimester placenta according to cell cycle analysis: the proliferative subset and other two non- proliferative subsets (17). Based on the expression level of RRM2 EVT can be divided into three subtypes: the positive one located at the proximal end of cell column and the other two subtypes with little or low expression of RRM2 which locates at the distal end of cell column (17). CTB, cytotrophoblast; EVT, extravillous trophoblast; EGFR, epidermal growth factor receptor; NRP2, neuropilin-2; HGFR, hepatocyte growth factor receptor; RRM2, ribonucleotide reductase regulatory subunit M2; HLA, human leukocyte antigen; ACKR2, atypical chemokine receptor 2; CXCR6, C-X-C chemokine receptor type 6.