Novel mineralocorticoid receptor mechanisms regulate cardiac tissue inflammation in male mice

MR activation in macrophages is critical for the development of cardiac inflammation and fibrosis. We previously showed that MR activation modifies macrophage pro-inflammatory signalling, changing the cardiac tissue response to injury via both direct gene transcription and JNK/AP-1 second messenger pathways. In contrast, MR-mediated renal electrolyte homeostasis is critically determined by DNA-binding-dependent processes. Hence, ascertaining the relative contribution of MR actions via DNA binding or alternative pathways on macrophage behaviour and cardiac inflammation may provide therapeutic opportunities which separate the cardioprotective effects of MR antagonists from their undesirable renal potassium-conserving effects. We developed new macrophage cell lines either lacking MR or harbouring a mutant MR incapable of DNA binding. Western blot analysis demonstrated that MR DNA binding is required for lipopolysaccharide (LPS), but not phorbol 12-myristate-13-acetate (PMA), induction of the MAPK/pJNK pathway in macrophages. Quantitative RTPCR for pro-inflammatory and pro-fibrotic targets revealed subsets of LPS- and PMA-induced genes that were either enhanced or repressed by the MR via actions that do not always require direct MR-DNA binding. Analysis of the MR target gene and profibrotic factor MMP12 identified promoter elements that are regulated by combined MR/MAPK/JNK signalling. Evaluation of cardiac tissue responses to an 8-day DOC/salt challenge in mice selectively lacking MR DNA-binding in macrophages demonstrated levels of inflammatory markers equivalent to WT, indicating non-DNA binding-dependent MR signalling in macrophages is sufficient for DOC/salt-induced tissue inflammation. Our data demonstrate that the MR regulates a macrophage pro-inflammatory phenotype and cardiac tissue inflammation, partially via pathways that do not require DNA binding.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:246

Enthalten in:

The Journal of endocrinology - 246(2020), 2 vom: 27. Aug., Seite 123-134

Sprache:

Englisch

Beteiligte Personen:

Ong, Gregory S Y [VerfasserIn]
Cole, Timothy J [VerfasserIn]
Tesch, Gregory H [VerfasserIn]
Morgan, James [VerfasserIn]
Dowling, Jennifer K [VerfasserIn]
Mansell, Ashley [VerfasserIn]
Fuller, Peter J [VerfasserIn]
Young, Morag J [VerfasserIn]

Links:

Volltext

Themen:

Cardiac fibrosis
EC 3.4.24.65
JNK
Journal Article
Lipopolysaccharides
Macrophage
Matrix Metalloproteinase 12
Mineralocorticoid receptor
Non-genomic
Nuclear receptor
Receptors, Cytoplasmic and Nuclear
Receptors, Mineralocorticoid
Research Support, Non-U.S. Gov't

Anmerkungen:

Date Completed 25.01.2021

Date Revised 25.01.2021

published: Print

Citation Status MEDLINE

doi:

10.1530/JOE-20-0161

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM310464536