title: Aldosterone synergizes with peripheral inflammation to induce brain IL-1β expression and depressive-like effects.
abstract: Recent findings have shown that the physiological functions of the hormone aldosterone go far beyond its well-known role in blood-pressure regulation and salt/water homeostasis. Aldosterone is for example involved in the regulation of inflammation, and also binds directly to mineralocorticoid receptors in specific brain regions. Interestingly, depressive symptoms appear to correlate with alterations of the aldosterone system but the underlying mechanisms have not been elucidated. In this study aldosterone (2 μg/100g body weight/day) was continuously administered via osmotic minipumps for 5 days. Lipopolysaccharide (LPS) was administered once a day for 5 days in a dose of 1mg/kg ip. The rats were tested for depressive-like behavior 24h after the last LPS injection. Protein levels of cytokines were measured in serum and cerebrospinal fluid (CSF). mRNA expression of interleukin (IL)-1β and IL-6 in the prefrontal cortex (PFC) was analyzed using reverse transcriptase qPCR. We found that aldosterone treatment increased LPS-induced IL-1β mRNA expression in the PFC and CSF. Moreover, there was a positive correlation between IL-1β in CSF and depressive-like behaviors. These findings suggest that IL-1β is affected by the renin-aldosterone-angiotensin system (RAAS) activity and connected to symptoms of depression.
authors.affiliation: Psychoimmunology Unit, Division of Psychiatry, Department of Clinical Sciences, Lund University, Kioskgatan 19, 22185 Lund, Sweden. Cecilie.Bay_Richter@med.lu.se
authors.forename: Cecilie
authors.initials: C
authors.lastname: Bay-Richter
authors.forename: Ludvig
authors.initials: L
authors.lastname: Hallberg
authors.forename: Filip
authors.initials: F
authors.lastname: Ventorp
authors.forename: Shorena
authors.initials: S
authors.lastname: Janelidze
authors.forename: Lena
authors.initials: L
authors.lastname: Brundin
mesh_terms: D000450:Aldosterone / Q000008:administration & dosage / Q000502:physiology*; D000818:Animals; D001522:Behavior, Animal; D016207:Cytokines / Q000097:blood / Q000134:cerebrospinal fluid; D003863:Depression / Q000378:metabolism; D003866:Depressive Disorder / Q000378:metabolism*; D007249:Inflammation; D053583:Interleukin-1beta / Q000097:blood* / Q000134:cerebrospinal fluid* / Q000235:genetics; D015850:Interleukin-6 / Q000235:genetics; D008070:Lipopolysaccharides / Q000276:immunology; D008297:Male; D017397:Prefrontal Cortex / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012084:Renin-Angiotensin System
chemical_list: D016207:Cytokines; D053583:Interleukin-1beta; D015850:Interleukin-6; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D000450:Aldosterone