title: Expression of GABA receptors subunits in peripheral blood mononuclear cells is gender dependent, altered in pregnancy and modified by mental health.
abstract: OBJECTIVE
  The concept of nerve-driven immunity recognizes a link between the nervous and the immune system. γ-aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the brain, and receptors activated by GABA can be expressed by immune cells. Here, we examined whether the expression of GABA receptors and chloride transporters in human peripheral blood mononuclear cells (PBMCs) was influenced by gender, pregnancy or mental health.
  
  
  METHODS
  We used RT-qPCR to determine the mRNA expression level in PBMCs from men (n = 16), non-pregnant women (n = 19), healthy pregnant women (n = 27) and depressed pregnant women (n = 15).
  
  
  RESULTS
  The ρ2 subunit had the most prominent expression level of the GABA-A receptor subunits in all samples. The δ and ρ2 subunits were up-regulated by pregnancy, whereas the ε subunit was more frequently expressed in healthy pregnant women than non-pregnant women who, in turn, commonly expressed the α6 and the γ2 subunits. The β1 and ε subunits expression was altered by depression in pregnant women. The GABA-B1 receptor was up-regulated by depression in pregnant women, while the transporters NKCC1 and KCC4 were down-regulated by pregnancy. The changes recorded in the mRNA expression levels imply participation of GABA receptors in establishing and maintaining tolerance in pregnancy. Importantly, the correlation of mental health with the expression of specific receptor subunits reveals a connection between the immune cells and the brain. Biomarkers for mental health may be identified in PBMCs.
  
  
  CONCLUSIONS
  The results demonstrate the impact gender, pregnancy and mental health have on the expression of GABA receptors and chloride transporters expressed in human PBMCs.
authors.affiliation: Department of Neuroscience, Uppsala University, Uppsala, Sweden.
authors.forename: A K
authors.initials: AK
authors.lastname: Bhandage
authors.forename: C
authors.initials: C
authors.lastname: Hellgren
authors.forename: Z
authors.initials: Z
authors.lastname: Jin
authors.forename: E B
authors.initials: EB
authors.lastname: Olafsson
authors.forename: I
authors.initials: I
authors.lastname: Sundström-Poromaa
authors.forename: B
authors.initials: B
authors.lastname: Birnir
mesh_terms: D000328:Adult; D003863:Depression / Q000175:diagnosis / Q000235:genetics* / Q000523:psychology; D005260:Female; D005819:Genetic Markers; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000737:chemistry*; D008297:Male; D008603:Mental Health; D011247:Pregnancy; D021122:Protein Subunits; D012333:RNA, Messenger / Q000032:analysis*; D011963:Receptors, GABA-A / Q000235:genetics*; D018080:Receptors, GABA-B / Q000235:genetics*; D012737:Sex Factors; D064506:Solute Carrier Family 12, Member 2 / Q000235:genetics; D027981:Symporters / Q000235:genetics; D055815:Young Adult; D000096922:K Cl- Cotransporters
chemical_list: D005819:Genetic Markers; D021122:Protein Subunits; D012333:RNA, Messenger; D011963:Receptors, GABA-A; D018080:Receptors, GABA-B; D064506:Solute Carrier Family 12, Member 2; D027981:Symporters; C578877:SLC12A2 protein, human; C119651:SLC12A7 protein, human; D000096922:K Cl- Cotransporters
keywords: GABA-A; GABA-B; NKCC1; PBMC; depression; pregnancy