Characterization of Parathyroid Hormone-Related Protein in the Human Term Placenta.

Abstract

To characterize parathyroid hormone-related protein (PTHrP) in the human placenta, we measured PTHrP-like immunoreactivity (PRP-LI) in the term placenta and studied the elution profiles of placental tissue extracts on Sephadex G-75 chromatography with a specific RIA. We also examined the gene expression of PTHrP mRNA by Northern blot analysis and the localization of PRP-LI in the placenta by immunohistochemistry. The amount of PRP-LI in placental extracts (n = 7) was 20.9 +/- 2.2 pg/g wet tissue (mean +/- SE). Dilution curves of placental tissue ran parallel to those of synthetic PTHrP (1-34) standards. Sephadex G-75 gel chromatography demonstrated two major PRP-LI peaks; the first peak was eluted around the molecular size between 10 kilodaltons (Kda) and 20 Kda and the other around 5 Kda. Northern blot analysis of PTHrP mRNA extracted from placental tissues showed a major hybridization signal around 18S. PTHrP immunohistochemistry showed PRP-LI staining in the cytoplasm of syncytiotrophoblasts and stroma cells (Hofbauer cells) in the term placenta. These results suggest that syncytiotrophoblasts and stroma cells in the term placenta synthesize PTHrP in two major molecular forms, 10 Kda-20 Kda and around 5 Kda.

Hypercalcemia associated with parathyroid hormone-related protein produced by B-cell type primary malignant lymphoma of the kidney

“…The tissue was also stained with anti-pan B-cell monoclonal antibodies (mAbs) L26, MB1 (anti-CD20), and with anti-T-cell mAb UCHL-1 (anti-CD45RO) by the ABC method. Northern blotting analysis of PTHrP was carried out using 10 mg of total mRNA extracted from the lymph node, or from normal liver obtained by surgery as a control tissue [13]. Table 1 shows laboratory findings at the time of hypercalcemia.…”

The Effect of Cytokines on Parathyroid Hormone-Related Protein (PTH-rP) Production in Human Amnion Cells.

“…While PTH gene has a simple structure and appears to be expressed principally by the parathyroid gland, the PTH-rP gene has a complex organization and is expressed in a wide variety of normal tissues and cell types including the tissues of fetus and those of the reproductive tract [2][3][4][5][6][7][8].…”

Undifferentiated Carcinoma in the Cardioesophageal Junction which Produces Parathyroid Hormone Related Protein.

“…Immunohistochemistry was carried out by the method described in a previous report (3). Tissues were fixed in 5% paraformaldehyde solution buffered with phosphate-buffered saline (50 mM,pH 7.4) and embedded in paraffin.…”

“…Serum PTHrP Serum PTHrPlevels were measured by radioimmunoassay (RIA) using the antisera against human PTHrP 109-141 (CPTHrP) and PTHrP 1-34 (N-PTHrP) as described previously (2,3). Figure 4 shows changes in serum C-PTHrP and Ca levels in response to medical treatments.…”