Summary of studies examining the impact of inflammation on amino acid transporter expression in the placenta
Amino acid substrates are taken from Cleal et al., 2018 unless otherwise specified. Drug substrates are italicized and taken from Zhang et al., 2020. ↑ signifies increased expression, ↓ signifies decreased expression, ↔ signifies no change in expression, and X signifies that expression was not assessed. When possible, the approximate magnitude of change is provided as percent increase or decrease. (F) denotes a change in female placentas, (M) denotes a change in male placentas.
| Transporter | Substrates | Model | Condition/Treatment | mRNA | Protein | Reference |
|---|---|---|---|---|---|---|
| EAAT2 (SLC1A2) | Aspartate, glutamate | Rats | Poly(I:C) | ↔ | ↓45% | (McColl and Piquette‐Miller, 2019) |
| ASCT1 (SLC1A4) | Alanine, serine, cysteine, threonine | Mice | Pre-eclampsia | ↔ | X | (Stojanovska et al., 2019) |
| Rats | Poly(I:C) | ↑90% | ↓75% | (McColl and Piquette‐Miller, 2019) | ||
| Horses | Ascending placentitis | ↓ | X | (El-Sheikh Ali et al., 2021) | ||
| ASCT2 (SLC1A5) | Alanine, serine, cysteine, glutamine, threonine, asparagine | Human chorionic plate arteries | Pre-eclampsia (plus TNF-α and IFN-γ) | ↔ | X | (Broekhuizen et al., 2020) |
| Humans | Pre-eclampsia | X | ↔ | (Aiko et al., 2014) | ||
| ↔ | X | (Chen et al., 2006) | ||||
| 4F2hc (SLC3A2) | Chaperone subunit for LAT1 and LAT2 | Humans | Pre-eclampsia | X | ↑25% | (Aiko et al., 2014) |
| Mice | Pre-eclampsia | ↔ | X | (Stojanovska et al., 2019) | ||
| Malaria | ↓65% | X | (Najjar et al., 2019) | |||
| Rats | Poly(I:C) | ↑50% | X | (McColl and Piquette‐Miller, 2019) | ||
| Horses | Ascending placentitis | ↓ | X | (El-Sheikh Ali et al., 2021) | ||
| TAUT (SLC6A6) | Taurine | Rats | Poly(I:C) | ↑75% | ↑75% | (McColl and Piquette‐Miller, 2019) |
| CAT1 (SLC7A1) | Arginine, histidine, lysine | Mice | Malaria | ↓70% | X | (Najjar et al., 2019) |
| CAT2 (SLC7A2) | Arginine, histidine, lysine | HUVEC | TNF-α | ↑380% | X | (Knyazev et al., 2017) |
| Rats | Poly(I:C) | ↑40% | X | (McColl and Piquette‐Miller, 2019) | ||
| CAT3 (SLC7A3) | Arginine, histidine, lysine | Mice | Preimplantation genetic diagnosis | ↓30% | ↓60% | (Yao et al., 2016) |
| LAT1 (SLC7A5) | Leucine, isoleucine, valine, phenylalanine, tyrosine, tryptophan, methionine, histidine, L-DOPA, melphalan, baclofen, gabapentin | Humans | Pre-eclampsia | X | ↑ | (Aiko et al., 2014) |
| Human chorionic plate arteries | Pre-eclampsia (plus TNF-α and IFN-γ) | ↔ | X | (Broekhuizen et al., 2020) | ||
| Mice | Malaria | ↓80% | X | (Najjar et al., 2019) | ||
| LAT2 (SLC7A8) | Leucine, isoleucine, valine, alanine, serine, threonine, cysteine, phenylalanine, tyrosine, tryptophan, asparagine, histidine, methionine, glutamine, glycine | Human chorionic plate arteries | Pre-eclampsia (plus TNF-α and IFN-γ) | ↔ | X | (Broekhuizen et al., 2020) |
| Mice | Preimplantation genetic diagnosis | ↓25% | X | (Yao et al., 2016) | ||
| BAT1 (SLC7A9) | Arginine, histidine, lysine, phenylalanine, tyrosine, tryptophan, threonine, methionine, valine, isoleucine, leucine | Horses | Ascending placentitis | ↓ | X | (El-Sheikh Ali et al., 2021) |
| SNAT1 (SLC38A1) | Glutamine, alanine, asparagine, cysteine, histidine, serine | Primary human trophoblasts | TNF-α | ↔ | ↑70-80% | (Jones et al., 2009; Aye et al., 2015) |
| IL-6 | ↔ | ↑80% | (Jones et al., 2009) | |||
| Poly(I:C) | ↑50% | ↑45% | (Liong and Lappas, 2017) | |||
| LPS | ↑160% | ↑60% | ||||
| BeWo-b30 cells (M) | IL-1β | ↓40% | X | (Thongsong et al., 2005) | ||
| Human placentas | Malaria | ↓50% | X | (Boeuf et al., 2013) | ||
| Mice | Preimplantation genetic diagnosis | ↓20% | X | (Yao et al., 2016) | ||
| Pre-eclampsia | ↓50% (F) ↔ (M) | X | (Stojanovska et al., 2019) | |||
| Rats | Poly(I:C) | ↑35% | X | (McColl and Piquette‐Miller, 2019) | ||
| SNAT2 (SLC38A2) | Alanine, asparagine, cysteine, glutamine, glycine, histidine, methionine, proline, serine | Primary human trophoblasts | TNF-α | ↑50% | ↑70% | (Jones et al., 2009) |
| ↔ | ↑70% | (Aye et al., 2015) | ||||
| IL-6 | ↑80% | ↑55% | (Jones et al., 2009) | |||
| Poly(I:C) | ↑100% | X | (Liong and Lappas, 2017) | |||
| LPS | ↑100% | X | ||||
| BeWo-b30 cells (M) | IL-1β | ↓15% | X | (Thongsong et al., 2005) | ||
| Human placentas | Malaria | ↓50% (trend) | X | (Boeuf et al., 2013) | ||
| Primary murine trophoblasts | TNF-α | ↓40% | X | (Claycombe-Larson et al., 2020) | ||
| IL-1β | ↔ | X | ||||
| Mice | Pre-eclampsia | ↔ | X | (Stojanovska et al., 2019) | ||
| Rats | Poly(I:C) | ↑30% | ↓20% (trend) | (McColl and Piquette‐Miller, 2019) | ||
| SNAT4 (SLC38A4) | Alanine, asparagine, cysteine, glycine, serine, threonine | Primary human trophoblasts | TNF-α | ↔ | ↔ | (Jones et al., 2009; Aye et al., 2015) |
| IL-6 | ↔ | ↔ | (Jones et al., 2009) | |||
| Mice | PE | ↔ | X | (Stojanovska et al., 2019) | ||
| SNAT5 (SLC38A5) | Glutamine, histidine, asparagine, serine | Humans | Pre-eclampsia (with or without IUGR) | X | ↔ | (Huang et al., 2018) |
| SNAT7 (SLC38A7) | Glutamine, histidine, alanine, serine, asparagine (Hagglund et al., 2011) | Horses | Ascending placentitis | ↓ | X | (El-Sheikh Ali et al., 2021) |
HUVEC human umbilical vein endothelial cell; IUGR, intrauterine growth restriction.