Toll-like receptor 4-mediated growth of endometriosis by human heat-shock protein 70.
BACKGROUND
We investigated the role of human heat-shock protein 70 (Hsp70) in Toll-like receptor 4 (TLR4)-mediated growth of endometriosis.


METHODS
TLR4 expression was examined in macrophages (M) isolated in primary culture from the peritoneal fluid of women with and without endometriosis. The production of a number of macromolecules by non-treated M, Hsp70-treated M and after treatment with anti-TLR4 antibody was examined by enzyme linked immunosorbent assay (ELISA). The single and combined effects of Hsp70 and lipopolysaccharide (LPS) on the growth of endometrial stromal cells were analyzed by 5-bromo-2-deoxyuridine (BrdU) incorporation study. Hsp70 levels in eutopic and ectopic endometria were measured by ELISA.


RESULTS
TLR4 was detected in isolated M at protein and gene level. Hsp70 (10 microg/ml) significantly stimulated the production of hepatocyte growth factor, vascular endothelial cell growth factor, interleukin-6 and tumor necrosis factor alpha by M derived from women with endometriosis compared with M derived from women with no endometriosis (P < 0.05 for each). This effect of Hsp70 was abrogated after pretreatment of M with anti-TLR4 antibody. BrdU incorporation indicated that Hsp70 significantly enhanced the growth of endometrial stromal cells ( approximately 50% increase) from women with endometriosis compared to non-treated cells. A synergistic effect on cell proliferation was observed between exogenous Hsp70 and LPS and this was significantly suppressed by pretreatment of cells with anti-TLR4 antibody (P < 0.05). Tissue levels of Hsp70 were significantly higher in the eutopic endometria (P < 0.05) and opaque red lesions (P < 0.01) derived from women with endometriosis than from other peritoneal lesions or from women with no endometriosis.


CONCLUSIONS
A prominent stress reaction was observed in blood-filled opaque red peritoneal lesions. Human Hsp70 induces pelvic inflammation and may be involved in TLR4-mediated growth of endometrial cells derived from women with endometriosis.
Khan
Khaleque Newaz
KN
Department of Obstetrics and Gynecology, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki 852-8501, Japan. nemokhan@nagasaki-u.ac.jp
Kitajima
Michio
M
Imamura
Takehito
T
Hiraki
Koichi
K
Fujishita
Akira
A
Sekine
Ichiro
I
Ishimaru
Tadayuki
T
Masuzaki
Hideaki
H
D000328:Adult; D049109:Cell Proliferation / Q000187:drug effects; D016207:Cytokines / Q000378:metabolism; D004715:Endometriosis / Q000378:metabolism* / Q000473:pathology; D004717:Endometrium; D004731:Endotoxins / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005786:Gene Expression Regulation; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism / Q000494:pharmacology / Q000502:physiology*; D017228:Hepatocyte Growth Factor / Q000235:genetics / Q000378:metabolism; D006801:Humans; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000378:metabolism; D017154:Stromal Cells / Q000166:cytology / Q000187:drug effects; D051197:Toll-Like Receptor 4 / Q000378:metabolism / Q000502:physiology*
D016207:Cytokines; D004731:Endotoxins; C066855:HGF protein, human; D018840:HSP70 Heat-Shock Proteins; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4; D017228:Hepatocyte Growth Factor