Production of secretory leukocyte protease inhibitor by human amniotic membranes and regulation of its concentration in amniotic fluid

Abstract

Secretory leukocyte protease inhibitor (SLPI) is a potent inhibitor of human leukocyte elastase. SLPI is a protein found in various human fluids, including parotid secretions, cervical mucus, seminal plasma and ascites. Western blot analysis revealed that SLPI protein is detected as a 12 kDa band in both the amniotic fluid and the amniotic membrane. The amniotic fluid concentrations of SLPI were assayed by enzyme-linked immunosorbent assay. SLPI concentrations in the amniotic fluid of women in the third trimester were higher than those in the second trimester. Immunohistochemistry using an anti-SLPI polyclonal antibody revealed positive staining in epithelial cells in amniotic membranes. Reverse transcription-polymerase chain reaction demonstrated that SLPI transcripts could be detected in the amniotic membranes. To determine the mechanism of SLPI production by amniotic cells, purified amniotic cells were stimulated with various cytokines. Amniotic cells produced SLPI in a dose-dependent manner when stimulated with interleukin (IL)-1alpha, IL-1beta, and tumour necrosis factor-alpha. The present findings show that SLPI is produced by the amniotic membranes in response to cytokine concentrations. The SLPI in the amniotic fluid may contribute to immunodefence mechanisms during pregnancy.

Antimicrobial peptides and pregnancy

“…SLPI has been localized in first trimester deciduas (King et al 2000) and in the amnion epithelium and deciduas at term (Denison et al 1999, Zhang et al 2001. SLPI is also found in amniotic fluid, with levels shown to rise between the second and the third trimester and continuing to increase at the time of term labor (Denison et al 1999, Zhang et al 2001.…”

“…SLPI is also found in amniotic fluid, with levels shown to rise between the second and the third trimester and continuing to increase at the time of term labor (Denison et al 1999, Zhang et al 2001. High concentrations of SLPI have been identified in the vernix caseosa (Akinbi et al 2004) and in the cervical mucus plug and cervical tissue (Helmig et al 1995, Hein et al 2002.…”

Regulation of Expression of Secretory Leukocyte Protease Inhibitor by Progesterone in BeWo Choriocarcinoma Cells

“…During our studies on the profiling of genes during differentiation of uni-nucleated cytotrophoblasts (CT) into multinucleated syncytiotrophoblasts (ST) by DDRT-PCR and micro array analysis of RNA from CT and ST we found several fold increase in the expression of SLPI in the ST [1]. It is also known that it exhibits a variety of activities, which includes anti-protease, anti-inflammatory, anti-bacterial activities [2]. SLPI is a highly conserved protein and murine SLPI appears to be structurally highly similar to human SLPI [3].…”

Overexpression of histamine H1-receptor by human amniotic epithelial cells in chorioamnionitis correlates with augmented production of secretory leukocyte protease inhibitor

“…Human amniotic epithelial cells (HAEC) produce secretory leukocyte protease inhibitor (SLPI) -an effective regulator of important immunological functions [3]. Anti-inflammatory and anti-microbial activities of SLPI within fetal membranes may modulate the course of CHA.…”