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Female sex hormones modulate the function of LPS-treated macrophages
1Department of Surgery, Chang Gung University College of Medicine, and Chang Gung Memorial Hospital, Taipei, Taiwan. ischen01@ms15.hinet.net
Problem:
To study the effects of estradiol (E2) or progesterone on macrophage function in the presence of lipopolysaccharide (LPS).
Method Of Study:
Male rat peritoneal macrophages were treated in vitro with 0.1 microg/mL of LPS and E2 or progesterone.
Results:
At 10(-2) ng/mL, E2 significantly (P < 0.05; n = 6) enhanced tumor necrosis factor (TNF) release by LPS-treated macrophages. TNF release was significantly (P < 0.05; n = 6) inhibited by 10(2) ng/mL or 10(3) ng/mL of E2 and by progesterone at less than 10(-3) ng/mL or greater than 10(-1) ng/mL. E2 (10(-4) and 10 ng/mL) and progesterone (10(-6)-10(-4) ng/mL and 10(2) ng/mL) each significantly (P < 0.05, n = 8) enhanced H2O2 release by LPS-treated macrophages. E2 ( < 10(-2) and > 10 ng/mL) and progesterone (10(-7)-10(4) ng/mL) each significantly inhibited (P< 0.05; n = 6) NO2- release by LPS-treated macrophages.
Conclusions:
Exposure to LPS tended to diminish the effects of E2 and to enhance the effects of progesterone on the parameters determined here. Such LPS-associated alterations in the dose-response profile of macrophages to female sex hormones may contribute to gender-related differences in the immune response under normal and pathological conditions.
Insights
Estradiol (E2) and progesterone modulate macrophage function differently when exposed to lipopolysaccharide (LPS). LPS alters how macrophages respond to these hormones, potentially explaining sex-based immune differences.
Area of Science:
- Immunology
- Endocrinology
- Cell Biology
Background:
- Macrophages are key immune cells involved in host defense.
- Sex hormones like estradiol (E2) and progesterone can modulate immune cell function.
- Lipopolysaccharide (LPS) is a potent activator of macrophages, often used to mimic bacterial infection.
Purpose of the Study:
- To investigate the impact of E2 and progesterone on macrophage function in the presence of LPS.
- To determine how LPS affects the dose-response of macrophages to E2 and progesterone.
Main Methods:
- Male rat peritoneal macrophages were cultured in vitro.
- Macrophages were treated with LPS (0.1 microg/mL) in combination with varying concentrations of E2 or progesterone.
- Key macrophage functions measured included the release of tumor necrosis factor (TNF), hydrogen peroxide (H2O2), and nitrite (NO2-).
Main Results:
- E2 at low concentrations (10(-2) ng/mL) enhanced TNF release, while higher concentrations (10(2)-10(3) ng/mL) inhibited it. Progesterone showed complex effects on TNF release.
- Both E2 and progesterone significantly enhanced H2O2 release by LPS-treated macrophages across various concentrations.
- E2 and progesterone differentially modulated nitrite release, with both hormones inhibiting NO2- production at specific concentration ranges.
Conclusions:
- LPS exposure appears to reduce the sensitivity of macrophages to E2 while increasing their sensitivity to progesterone.
- These LPS-induced alterations in hormone response may contribute to observed gender-related disparities in immune responses during health and disease.
- Understanding these interactions is crucial for addressing sex differences in inflammatory and infectious conditions.