Effects of oestrogen deprivation on interleukin-6 production by peripheral blood mononuclear cells of postmenopausal women

Abstract

Various hormones can influence the expression of interleukin-6 (IL-6) and oestrogens are the most extensively studied. There is, however, controversy about the nature of the IL-6 secreted by human cells and its regulation by 17 -oestradiol. The aim of this work was to clarify whether oestrogen deprivation after menopause may contribute to an enhanced IL-6 production by peripheral blood mononuclear cells (PBMC) in postmenopausal women. Twenty-two healthy postmenopausal women, age range 45-63 years, with clinical symptoms of oestrogen deficiency were enrolled in the study. The control group consisted of 16 healthy young women, age range 22-31 years, with regular menses and who were not taking oral contraceptives. Levels of IL-6 in the sera and PBMC culture supernatants were measured by the biological B9 cell-proliferation assay and expression of the IL-6 gene in non-stimulated PBMC was detected by RT-PCR. The effect of 17 -oestradiol on spontaneous IL-6 production by the PBMC of postmenopausal women was also studied in vitro and in vivo. Seventeen out of the twenty-two postmenopausal women were given hormonal replacement therapy of 50 µg 17 -oestradiol/day transdermally and the spontaneous production of IL-6 by the PBMC was analysed after 6 and 12 months of treatment.The postmenopausal women had significantly higher serum levels of IL-6 than the young controls. The spontaneous production of IL-6 by non-stimulated PBMC into the culture supernatants was also significantly higher in the postmenopausal women compared with the young. We also found that IL-6 gene expression was present in the non-stimulated PBMC isolated directly from the venous blood of the majority of the postmenopausal women. Women with IL-6 gene expression in the nonstimulated PBMC had significantly lower serum levels of 17 -oestradiol compared with those where the IL-6 gene was not expressed in the PBMC. Our in vitro experiments showed that 17 -oestradiol at concentrations of 10 9 M and 10 10 M decreased spontaneous IL-6 production by the PBMC of postmenopausal women. In vivo treatment with 17 -oestradiol transdermally also significantly decreased spontaneous IL-6 production by the PBMC of postmenopausal women after 12 months of the therapy.Our results indicate that oestrogen deprivation after menopause may enhance IL-6 production by the PBMC of postmenopausal women. We suspect that the late complications of oestrogen deficiency, such as osteoporosis, coronary heart disease and Alzheimer's disease, may be mediated by an exaggerated production of IL-6 -a cytokine which seems to play a pivotal role in the pathogenesis of these age-related diseases.

Effects of aging and menopause on serum interleukin-6 levels and peripheral blood mononuclear cell cytokine production in healthy nonobese women

“…This result might reflect a loss in the regulatory effect of estrogen on PBMC cytokine production in postmenopausal women. This is consistent with the finding of Rachoń et al (2002), who determined that women with non-stimulated PBMCs that express IL-6 have significantly lower serum levels of estradiol, as compared to women with PBMCs that do not express IL-6. It has also been suggested that increased cytokine production in healthy, older individuals result from reduced levels of sex hormones (Ershler and Keller 2000).…”

“…Postmenopausal status (n=94) was defined as an absence of menstruation for at least 12 months and the presence of estrogen deficiency symptoms including "hot flushes," increased sweating, nervousness, irritability, depression, palpitations, insomnia, headaches, dyspareunia, and joint pains. The cessation of ovarian function was confirmed by measurement of serum levels of follicle-stimulating hormone (FSH), which should be above 40 IU/L if loss of ovarian function has occurred (Rachoń et al 2002). Premenopausal status (n=114) was defined as the presence of regular menses (Rachoń et al 2002).…”

“…The cessation of ovarian function was confirmed by measurement of serum levels of follicle-stimulating hormone (FSH), which should be above 40 IU/L if loss of ovarian function has occurred (Rachoń et al 2002). Premenopausal status (n=114) was defined as the presence of regular menses (Rachoń et al 2002). All participants were clinically healthy and were not taking any medications known to affect their immunological status including oral contraceptives, lipid-lowering agents, anti-hypertension drugs, functional foods, and vitamin and/or mineral supplementation.…”

“…Isolated PBMCs were cultured in RPMI 1640 (Gibco, Invitrogen, Carlsbad, CA, USA) supplemented with 10% fetal bovine serum (Gibco, Invitrogen, Carlsbad, CA, USA) and seeded in 12-well plates (1×10 6 cells/ml; Nunc, Roskilde, Denmark) and incubated at 37°C with 5% CO 2 for 24 h. Then, cells were stimulated with increasing concentrations of LPS (Escherichia coli 0111: B4, Sigma, St Louis, MO, USA; 0, 5, and 10 ng/mL). After a 24-h incubation, supernatants were collected and stored at −80°C until IL-1β, IL-6, and TNF-α levels were assayed (Rachoń et al 2002;von Haehling et al 2003).…”

Replacing with whole grains and legumes reduces Lp-PLA2 activities in plasma and PBMCs in patients with prediabetes or T2D

“…After the separation, a thin layer of PBMCs was isolated and washed twice with RPMI 1640. The pellet was resuspended in RPMI 1640 supplemented with 10% fetal bovine serum (Gibco, Invitrogen) and seeded in 12-well plates (1 × 106 cells/ml; Nunc, Roskilde, Denmark) and incubated at 37°C with 5% CO 2 for 24 h. After 24 h incubation, supernatants were collected and stored at 80°C until interleukin (IL)-1 ␤ , IL-6, TNF-␣ , and Lp-PLA 2 activity levels were assayed ( 13,14 ).…”