# Mineralocorticoid Receptor Signaling in Peripheral Blood Cells in Patients with Multiple Sclerosis

## TL;DR

This study explores how mineralocorticoid receptor signaling in blood cells differs in multiple sclerosis patients and how it might help guide treatment decisions.

## Contribution

The study identifies OTUD1 as a marker of MR signaling and shows its reduced expression in MS patients compared to controls.

## Key findings

- MR and OTUD1 mRNA expression is significantly lower in MS patients compared to controls.
- MR expression is particularly low in patients treated with fingolimod.
- OTUD1 may serve as a biomarker for MR signaling in MS.

## Abstract

Multiple sclerosis (MS) is associated with alterations in neuroendocrine function, primarily the hypothalamic–pituitary–adrenal axis, including lower expression of the glucocorticoid receptor (GR) and its target genes in peripheral blood mononuclear cells (PBMC) or full blood. We previously found reduced mineralocorticoid receptor (MR) expression in MS patients’ peripheral blood. MS is being treated with a widening variety of disease-modifying treatments (DMT), some of which have similar efficacy but different mechanisms of action; body-fluid biomarkers to support the choice of the optimal initial DMT and/or to indicate an unsatisfactory response before clinical activity are unavailable. Using cell culture of volunteers’ PBMCs and subsequent gene expression analysis (microarray and qPCR validation), we identified the mRNA expression of OTUD1 to represent MR signaling. The MR and MR target gene expression levels were then measured in full blood samples. In 119 MS (or CIS) patients, the expression of both MR and OTUD1 was lower than in 42 controls. The expression pattern was related to treatment, with the MR expression being particularly low in patients treated with fingolimod. While MR signaling may be involved in the therapeutic effects of some disease-modifying treatments, MR and OTUD1 expression can complement the neuroendocrine assessment of MS disease course. If confirmed, such assessment may support clinical decision-making.