TY - JOUR
T1 - Characterization and function of the human macrophage dopaminergic system
T2 - Implications for CNS disease and drug abuse
AU - Gaskill, Peter J.
AU - Carvallo, Loreto
AU - Eugenin, Eliseo A.
AU - Berman, Joan W.
N1 - Funding Information:
We thank all of the members of the Dr. Joan W. Berman Laboratory at Einstein for important discussions of the data and general support during this project. We also thank the Analytical Imaging Facility at Einstein for assistance with the confocal microscopy and the Einstein Center For AIDS Research (AI-051519) for use of their facilities and assistance designing the immunoassays. These studies were funded by the National Institutes of Drug Abuse grants DA029476 (PJG), DA026149 (LC and JWB), DA25567 (JWB) and the National Institutes of Mental Health grants MH096625 (EAE), MH090958 (LC and JWB), and MH075679 (JWB).
PY - 2012/8/18
Y1 - 2012/8/18
N2 - Background: Perivascular macrophages and microglia are critical to CNS function. Drugs of abuse increase extracellular dopamine in the CNS, exposing these cells to elevated levels of dopamine. In rodent macrophages and human T-cells, dopamine was shown to modulate cellular functions through activation of dopamine receptors and other dopaminergic proteins. The expression of these proteins and the effects of dopamine on human macrophage functions had not been studied.Methods: To study dopaminergic gene expression, qRT-PCR was performed on mRNA from primary human monocyte derived macrophages (MDM). Expression and localization of dopaminergic proteins was examined by immunoblotting isolated plasma membrane, total membrane and cytosolic proteins from MDM. To characterize dopamine-mediated changes in cytokine production in basal and inflammatory conditions, macrophages were treated with different concentrations of dopamine in the presence or absence of LPS and cytokine production was assayed by ELISA. Statistical significance was determined using two-tailed Students' T-tests or Wilcoxen Signed Rank tests.Results: These data show that MDM express mRNA for all five subtypes of dopamine receptors, and that dopamine receptors 3 and 4 are expressed on the plasma membrane. MDM also express mRNA for the dopamine transporter (DAT), vesicular monoamine transporter 2 (VMAT2), tyrosine hydroxylase (TH) and aromatic amino acid decarboxylase (AADC). DAT is expressed on the plasma membrane, VMAT2 on cellular membranes and TH and AADC are in the cytosol. Dopamine also alters macrophage cytokine production in both untreated and LPS-treated cells. Untreated macrophages show dopamine mediated increases IL-6 and CCL2. Macrophages treated with LPS show increased IL-6, CCL2, CXCL8 and IL-10 and decreased TNF-α.Conclusions: Monocyte derived macrophages express dopamine receptors and other dopaminergic proteins through which dopamine may modulate macrophage functions. Thus, increased CNS dopamine levels due to drug abuse may exacerbate the development of neurological diseases including Alzheimer's disease and HIV associated neurological disorders.
AB - Background: Perivascular macrophages and microglia are critical to CNS function. Drugs of abuse increase extracellular dopamine in the CNS, exposing these cells to elevated levels of dopamine. In rodent macrophages and human T-cells, dopamine was shown to modulate cellular functions through activation of dopamine receptors and other dopaminergic proteins. The expression of these proteins and the effects of dopamine on human macrophage functions had not been studied.Methods: To study dopaminergic gene expression, qRT-PCR was performed on mRNA from primary human monocyte derived macrophages (MDM). Expression and localization of dopaminergic proteins was examined by immunoblotting isolated plasma membrane, total membrane and cytosolic proteins from MDM. To characterize dopamine-mediated changes in cytokine production in basal and inflammatory conditions, macrophages were treated with different concentrations of dopamine in the presence or absence of LPS and cytokine production was assayed by ELISA. Statistical significance was determined using two-tailed Students' T-tests or Wilcoxen Signed Rank tests.Results: These data show that MDM express mRNA for all five subtypes of dopamine receptors, and that dopamine receptors 3 and 4 are expressed on the plasma membrane. MDM also express mRNA for the dopamine transporter (DAT), vesicular monoamine transporter 2 (VMAT2), tyrosine hydroxylase (TH) and aromatic amino acid decarboxylase (AADC). DAT is expressed on the plasma membrane, VMAT2 on cellular membranes and TH and AADC are in the cytosol. Dopamine also alters macrophage cytokine production in both untreated and LPS-treated cells. Untreated macrophages show dopamine mediated increases IL-6 and CCL2. Macrophages treated with LPS show increased IL-6, CCL2, CXCL8 and IL-10 and decreased TNF-α.Conclusions: Monocyte derived macrophages express dopamine receptors and other dopaminergic proteins through which dopamine may modulate macrophage functions. Thus, increased CNS dopamine levels due to drug abuse may exacerbate the development of neurological diseases including Alzheimer's disease and HIV associated neurological disorders.
KW - Aromatic amino acid decarboxylase
KW - Cytokine
KW - Dopamine
KW - Dopamine transporter
KW - Drug abuse
KW - Monocyte derived macrophage
KW - Neuroinflammation dopamine receptor
KW - Tyrosine hydroxylase
UR - http://www.scopus.com/inward/record.url?scp=84865053439&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84865053439&partnerID=8YFLogxK
U2 - 10.1186/1742-2094-9-203
DO - 10.1186/1742-2094-9-203
M3 - Article
C2 - 22901451
AN - SCOPUS:84865053439
SN - 1742-2094
VL - 9
JO - Journal of neuroinflammation
JF - Journal of neuroinflammation
M1 - 704
ER -