Modulation of heat shock proteins during macrophage differentiation.
OBJECTIVE
To evaluate the heat shock protein (HSP) variation during the differentiation and polarization of human macrophages.


METHODS
Gene expression analysis was investigated by real-time PCR from mRNA of human monocytes obtained from the buffy coats of healthy volunteers, polarized to classically activated macrophages (or M1), whose prototypical activating stimuli are interferon-gamma and lipopolysaccharide, and alternatively activated macrophages (or M2) obtained by interleukin-4 exposure. The modulation of HSPs at the transcriptomic levels was investigated using oligonucleotide microarray in the process of primary human monocyte-to-macrophage maturation and subsequent polarization into M1 or M2 cells.


RESULTS
We found that 11 HSPs transcripts were modulated throughout monocyte-to-macrophage differentiation. Furthermore a considerable effect on HSP expression was detected in conjunction with the M1 polarizing condition. This affected 21 transcripts in M1 cells, with 6 of them significantly upregulated in comparison to unpolarized macrophages, whereas 15 were downregulated. Slight changes in HSPs expression were observed in M2 cells when compared to unpolarized macrophages. Under these circumstances only five transcripts were significantly modulated. Interestingly, HSPBAP1 was the only HSP significantly downregulated in both M1 and M2 conditions parallel to a significant up-regulation of its target HSPB1.


CONCLUSIONS
Our study revealed that monocytes undergoing maturation differentially regulate the expression of several members of HSPs and that distinct patterns of HSP expression characterize the M1 and M2 effector stages of macrophage life.
Department of Bio-medical Sciences, University of Catania, Via Androne 83, 95124 Catania, Italy.
Paolo
P
Fagone
Michelino
M
Di Rosa
Maria
M
Palumbo
Corinne
C
De Gregorio
Ferdinando
F
Nicoletti
Lucia
L
Malaguarnera
D002454:Cell Differentiation / Q000235:genetics*; D002478:Cells, Cultured; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D006360:Heat-Shock Proteins / Q000235:genetics*; D006801:Humans; D008264:Macrophages / Q000166:cytology* / Q000378:metabolism; D009000:Monocytes / Q000166:cytology / Q000378:metabolism; D012333:RNA, Messenger
D006360:Heat-Shock Proteins; D012333:RNA, Messenger