33 research outputs found

    Gender Differences in S-Nitrosoglutathione Reductase Activity in the Lung

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    S-nitrosothiols have been implicated in the etiology of various pulmonary diseases. Many of these diseases display gender preferences in presentation or altered severity that occurs with puberty, the mechanism by which is unknown. Estrogen has been shown to influence the expression and activity of endothelial nitric oxide synthase (eNOS) which is associated with increased S-nitrosothiol production. The effects of gender hormones on the expression and activity of the de-nitrosylating enzyme S-nitrosoglutathione reductase (GSNO-R) are undefined. This report evaluates the effects of gender hormones on the activity and expression of GSNO-R and its relationship to N-acetyl cysteine (NAC)-induced pulmonary hypertension (PH). GSNO-R activity was elevated in lung homogenates from female compared to male mice. Increased activity was not due to changes in GSNO-R expression, but correlated with GSNO-R S-nitrosylation: females were greater than males. The ability of GSNO-R to be activated by S-nitrosylation was confirmed by: 1) the ability of S-nitrosoglutathione (GSNO) to increase the activity of GSNO-R in murine pulmonary endothelial cells and 2) reduced activity of GSNO-R in lung homogenates from eNOS−/− mice. Gender differences in GSNO-R activity appear to explain the difference in the ability of NAC to induce PH: female and castrated male animals are protected from NAC-induced PH. Castration results in elevated GSNO-R activity that is similar to that seen in female animals. The data suggest that GSNO-R activity is modulated by both estrogens and androgens in conjunction with hormonal regulation of eNOS to maintain S-nitrosothiol homeostasis. Moreover, disruption of this eNOS-GSNO-R axis contributes to the development of PH

    Regulation of monocyte chemoattractant protein-1 expression by tumor necrosis factor-alpha and interleukin-1beta in first trimester human decidual cells: implications for preeclampsia.

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    The current study describes a statistically significant increase in macrophages (CD68-positive cells) in the decidua of preeclamptic patients. To elucidate the regulation of this monocyte infiltration, expression of monocyte chemoattractant protein-1 (MCP-1) was assessed in leukocyte-free first trimester decidual cells. Confluent decidual cells were primed for 7 days in either estradiol or estradiol plus medroxyprogesterone acetate to mimic the decidualizing steroidal milieu of the luteal phase and early pregnancy. The medium was exchanged for a serum-free defined medium containing corresponding steroids / tumor necrosis factor (TNF)- or interleukin (IL)-1. After 24 hours, enzyme-linked immunosorbent assay measurements indicated that the addition of medroxyprogesterone acetate did not affect MCP-1 output, whereas 10 ng/ml of TNF- or IL-1 increased output by 83.5-fold 20.6 and 103.1-fold 14.7, respectively (mean SEM, n 8, P < 0.05). Concentration-response comparisons revealed that even 0.01 ng/ml of TNF- or IL-1 elevated MCP-1 output by more than 15-fold. Western blotting confirmed the enzymelinked immunosorbent assay results, and quantitative reverse transcriptase-polymerase chain reaction confirmed corresponding effects on MCP-1 mRNA levels. The current study demonstrates that TNF- and IL-1 enhance MCP-1 in first trimester decidua. This finding suggests a mechanism by which recruitment of excess macrophages to the decidua impairs endovascular trophoblast invasion, the primary placental defect of preeclampsia
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