Placental protein 13

Abstract

Placental protein 13 (PP13), a glycan binding protein predominantly expressed in syncytiotrophoblast, dimeric in nature, lacks N-terminal signal peptide, bypasses the endoplasmic reticulum, and secretes into maternal circulation as exosomes or microvesicles. PP13 has jelly roll fold conformation with conserved carbohydrate recognition domain which specifically binds to β-galactosides of the glycan receptors during placentation. PP13 binds to glycosylated receptors on human erythrocytes and brings about hemagglutination by the property of lectin activity; other functions are immunoregulation and vasodilation during placentation and vascularization. The gene LGALS13 located on 19q13.2 comprising four exons expresses a 32-kDa protein with 139 amino acid residues, PP13. Impaired expression due to mutation in the gene leads to a nonfunctional truncated PP13. The low serum levels predict high risk for the onset of preeclampsia or obstetric complications. Hence, PP13 turned to be an early marker for risk assessment of preeclampsia. The recombinant PP13 and monoclonal antibodies availability help for replenishing PP13 in conditions with low serum levels and for detection and prevention of preeclampsia, respectively.

First‐trimester plasma extracellular heat shock proteins levels and risk of preeclampsia

“…Recently, Martin et al 55 showed that the e Hsp‐27 concentration increases up to twofold in the first and second trimesters in patients with PE compared with healthy term patients. Also, this was associated with a decrease in placental protein‐13, which is involved in normal placentation 56,57 . Unfortunately, in this study, the functional role of e Hsp‐27 in the regulation of the inflammatory response was not addressed.…”

“…Also, this was associated with a decrease in placental protein-13, which is involved in normal placentation. 56,57 Unfortunately, in this study, the functional role of eHsp-27 in the regulation of the inflammatory response was not addressed.…”

Circulating biomarkers associated with placental dysfunction and their utility for predicting fetal growth restriction

“…PP13 is a glycan-binding protein mainly expressed in syncytiotrophoblast and secreted into the maternal circulation via exosomes or microvesicles [ 38 ]. Although an earlier observational study showed an association between low first trimester PP13 concentrations in maternal serum and FGR [ 39 ], subsequent studies [ 33 , 40 ] found limited predictive utility with no significant differences in median PP13 MoM levels in FGR-affected pregnancies even when combined with other first trimester screening markers such as PAPP-A [ 33 ] and ADAM12 [ 40 ].…”

The Role and Application of Exosomes and Their Cargos in Reproductive Diseases: A Systematic Review

“…It is decreased in the early stage of preeclampsia and increased in the later stage and through regulating the release of prostacycline to reshape the maternal spiral artery of the early placenta [35].…”