Steroid hormone bioavailability is controlled by the lymphatic system

Rahel Klossner,Michael Groessl,Geneviève Escher,Nadine Schumacher,Markus G Mohaupt,Bruno Vogt,Carine Gennari-Moser,Sophia Verouti,Michaela Fux,Heidi Jamin

doi:10.1038/s41598-021-88508-w

Abstract

The steroid hormone progesterone accounts for immune tolerance in pregnancy. Enhanced progesterone metabolism to 6α-OH-pregnanolone occurs in complicated pregnancies such as in preeclampsia with preterm delivery or intrauterine growth restriction, and in cancer. As lymphatic endothelial cells (LECs) promote tumor immunity, we hypothesized that human LECs modify progesterone bioavailability. Primary human LECs and mice lymph nodes were incubated with progesterone and progesterone metabolism was analyzed by thin layer chromatography and liquid chromatography-mass spectrometry. Expression of steroidogenic enzymes, down-stream signal and steroid hormone receptors was assessed by Real-time PCR. The placental cell line HTR-8/SV neo was used as reference. The impact of the progesterone metabolites of interest was investigated on the immune system by fluorescence-activated cell sorting analysis. LECs metabolize progesterone to 6α-OH-pregnanolone and reactivate progesterone from a precursor. LECs highly express 17β-hydroxysteroid dehydrogenase 2 and are therefore antiandrogenic and antiestrogenic. LECs express several steroid hormone receptors and PIBF1. Progesterone and its metabolites reduced TNF-α and IFN-γ production in CD4+ and CD8+ T cells. LECs modify progesterone bioavailability and are a target of steroid hormones. Given the global area represented by LECs, they might have a critical immunomodulatory control in pregnancy and cancer.

Highlights

Several reports have demonstrated that the 5α- and 5β-DHP metabolites are biologically active in pregnancy[18,19,20,21,22], but the mechanism leading to these metabolites remains to be elucidated
First, progesterone metabolism was assessed in primary human lymphatic endothelial cells (LECs) isolated from lymph nodes (HLEC) and results were confirmed in LECs isolated from lymphatic skin vessels; second, the resulting progesterone metabolite was identified and characterized by LC–MS; third, the enzymatic steps involved were clarified; fourth, human cell culture results were matched to ex-vivo mouse lymph node; fifth, the impact of the found progesterone metabolites 5α-dihydroprogesterone (5α-DHP) and 6α-OH-pregnanolone (6α-OH-Pregn) was tested on immune cells
HLECs and dLECs were cultured in steroid-free medium and incubated with 3H-cholesterol to quantify the de-novo synthesis of progesterone, corticosterone, cortisol, testosterone and estradiol (HLEC), and of progesterone, 11-deoxycortisol, corticosterone, aldosterone and cortisol, after an incubation time of 24 h

Summary

Introduction

Several reports have demonstrated that the 5α- and 5β-DHP metabolites are biologically active in pregnancy[18,19,20,21,22], but the mechanism leading to these metabolites remains to be elucidated. Several enzymes accounting for steroid hormone metabolism, progesterone metabolism, have been involved in cancer. These are the 6α-hydroxylase, the 5α-reductase, the 3β-hydroxysteroid dehydrogenase and 17β-hydroxysteroid dehydrogenase 2 (HSD17B2)[24,25,26,27,28,29]. The progesterone metabolite 5α-DHP produced by the enzyme 5α-reductase, is a target for prostate cancer and glioblastoma t herapy[30,31,32,33]. Many compounds targeting HSD17B2 activity in various cancers are under investigation[39]. The hypothesis of this investigation is that human LECs modify the bioavailability of progesterone. The placental cell line HTR-8/SVneo was used as a control and reference for the experiments with lymphatic endothelial cells

Methods

Results

Conclusion