Human Placental Tissue Contains A Placental Lactogen-Derived Vasoinhibin

Abstract

Hormonal factors affecting the vascular adaptions of the uteroplacental unit in noncomplicated and complicated pregnancies are of interest. Here, 4 human placentas from women with and without preeclampsia (PE) were investigated for the presence of placental lactogen (PL)-derived, antiangiogenic vasoinhibin. Western blotting and mass spectrometry of placental tissue revealed the presence of a 9-kDa PL-derived vasoinhibin, the normal 22-kDa full-length PL, and a 28-kDa immunoreactive protein of undetermined nature. The sequence of the 9-kDa vasoinhibin includes the antiangiogenic determinant of vasoinhibin and could constitute a relevant factor in normal pregnancy and PE.

Keywords: placenta; placental lactogen; preeclampsia; vasoinhibin.

Figure 1.

Western blot analysis of human placental lactogen (hPL) and human placental tissue lysates. Western blot probed with A, anti–full-length polyclonal PL antibodies; B, anti–N-terminal PL polyclonal antibodies; and C, anti–C-terminal PL polyclonal antibodies showing immunoreactive protein bands (indicated by arrowheads on left and right sides of blots) in the hPL standard (hPL Std) and in placental tissue extracts from preeclamptic and healthy individuals. The amino acid (AA) sequence and corresponding residue number of the peptides obtained after the enzymatic degradation of the 9-kDa protein from each placental tissue sample revealed by mass spectrometry is indicated in A (upward black arrowheads).