Transient increase in the levels of T-helper 1 cytokines in postmenopausal women and the effects of hormone replacement therapy

The foreign body response: emerging cell types and considerations for targeted therapeutics

The foreign body response (FBR) remains a clinical challenge in the field of biomaterials due to its ability to elicit a chronic and sustained immune response. Modulating the immune response to materials is a modern paradigm in tissue engineering to enhance repair while limiting fibrous encapsulation and implant isolation. Though the classical mediators of the FBR are well-characterized, recent studies highlight that our understanding of the cell types that shape the FBR may be incomplete. In this review, we discuss the emerging role of T cells, stromal-immune cell interactions, and senescent cells in the biomaterial response, particularly to synthetic materials. We emphasize future studies that will deepen the field's understanding of these cell types in the FBR, with the goal of identifying therapeutic targets that will improve implant integration. Finally, we briefly review several considerations that may influence our understanding of the FBR in humans, including rodent models, aging, gut microbiota, and sex differences. A better understanding of the heterogeneous host cell response during the FBR can enable the design and development of immunomodulatory materials that favor healing.

Menopause is an inflection point of age-related immune changes in women

Elevated proinflammatory cytokines in postmenopausal women is considered as one of the causes increasing the incidence of chronic inflammatory diseases. However, the details of postmenopausal immune changes have not yet been fully revealed. Thus, we investigated age-related immune changes in women and compared immune responses in postmenopausal and reproductive-age women. A total of 34 postmenopausal women and 91 reproductive-age women were included in the study. After isolating peripheral blood mononuclear cells, analysis of immunophenotypes and intracellular cytokine profiles were done. The proportion of natural killer (NK) cells was significantly higher, and the ratio of TNF-α- to IL-10-producing CD3+CD4 + T cells (Th1 to Th2) and the ratio of Th17 cells to CD4+CD25+Foxp3+ regulatory T (Treg) cells (Th17 to Treg) were higher, in postmenopausal women than in reproductive-age women. The Treg cell proportion was negatively correlated with the Th1 and Th2 cell proportions in reproductive-age women but not in postmenopausal women. As age increased, the proportion of Tregs was increased in reproductive-age women (r = 0.302, p = 0.004), whereas the proportion of Th1 cells was increased in postmenopausal women (r = 0.466, p = 0.005). FSH levels showed a positive correlation with Fopx3+ T cell and Treg cell (p = 0.04, 0.053, respectively), whereas Th17/Treg ratio and Th1 cell showed negative correlation with FSH.(p = 0.045, 0.024, respectively). In conclusion, postmenopausal women have higher proinflammatory immune statuses, as demonstrated by increased proportions of NK, Th1, and Th17 cells, altered correlations among NK and T cell subsets, and compromised balances between effector T cell subsets.

The Impact of Estrogen in the Tumor Microenvironment

Tumor immune escape is now a hallmark of cancer development, and therapies targeting these pathways have emerged as standard of care. Specifically, immune checkpoint signal blockade offers durable responses and increased overall survival. However, the majority of cancer patients still do not respond to checkpoint blockade immune therapy leading to an unmet need in tumor immunology research. Sex-based differences have been noted in the use of cancer immunotherapy suggesting that sex hormones such as estrogen may play an important role in tumor immune regulation. Estrogen signaling already has a known role in autoimmunity, and the estrogen receptor can be expressed across multiple immune cell populations and effect their regulation. While it has been well established that tumor cells such as ovarian carcinoma, breast carcinoma, and even lung carcinoma can be regulated by estrogen, research into the role of estrogen in the regulation of tumor-associated immune cells is still emerging. In this chapter, we discuss the role of estrogen in the tumor immune microenvironment and the possible immunotherapeutic implications of targeting estrogen in cancer patients.

Medroxyprogesterone Acetate Decreases Th1, Th17, and Increases Th22 Responses via AHR Signaling Which Could Affect Susceptibility to Infections and Inflammatory Disease

A synthetic progestin, medroxyprogesterone acetate (MPA), was used in a novel study to determine progestin effects on human purified macrophages and Th1, Th2, Th17, Th22 cells. MPA concentrations were equivalent to those in the serum of women after 6 and 9 months of progestin use. MPA has no effect on the proliferation of PBMCs and CD4+ T cell clones induced by immobilized anti-CD3 antibodies or by antigen (streptokinase). However, MPA decreases production and mRNA expression of IL-5, IL-13, IFN-γ, T-bet, RORC, and IL-17A but increases production and mRNA expression of IL-22 by CD4+ Th22 cell clones and decreases IL-22 production by Th17 cells. MPA inhibits RORC, but not T-bet and AHR, by Th17 cells but increases AHR mRNA and T-bet expression of established CD4+ Th22 cell clones. This suggests that MPA, at concentrations equivalent to those found in the serum of women after treatment for contraception and hormone replacement therapy, can directly inhibit Th1 responses (against intracellular bacteria and viruses), Th17 (against extracellular bacteria and fungi), Th2 (against parasites) but MPA therapy increases IL-22 produced by Th22 cells mediated by an increased expression of AHR and T-bet controlling inflammation. MPA could be responsible for the tissue damage limited by IL-22 in absence of IL-17A.

Immune Tumor Microenvironment in Breast Cancer and the Participation of Estrogen and Its Receptors in Cancer Physiopathology

Breast cancer is characterized by cellular and molecular heterogeneity. Several molecular events are involved in controlling malignant cell process. In this sense, the importance of studying multiple cell alterations in this pathology is overriding. A well-identified fact on immune response is that it can vary depend on sex. Steroid hormones and their receptors may regulate different functions and the responses of several subpopulations of the immune system. Few reports are focused on the function of estrogen receptors (ERs) on immune cells and their roles in different breast cancer subtypes. Thus, the aim of this review is to investigate the immune infiltrating tumor microenvironment and prognosis conferred by it in different breast cancer subtypes, discuss the current knowledge and point out the roles of estrogens and its receptors on the infiltrating immune cells, as well as to identify how different immune subsets are modulated after anti-hormonal treatments in breast cancer patients.

Sex differences in abdominal aortic aneurysms

Abdominal aortic aneurysm (AAA) is a vascular disorder with a high case fatality rate in the instance of rupture. AAA is a multifactorial disease, and the etiology is still not fully understood. AAA is more likely to occur in men, but women have a greater risk of rupture and worse prognosis. Women are reportedly protected against AAA possibly by premenopausal levels of estrogen and are, on average, diagnosed at older ages than men. Here, we review the present body of research on AAA pathophysiology in humans, animal models, and cultured cells, with an emphasis on sex differences and sex steroid hormone signaling.

Sarcoidosis of female reproductive organs in a postmenopausal woman: a case report and review of the literature: is there a potential for hormone therapy?

OBJECTIVE

Sarcoidosis is a multisystem inflammatory disorder of unknown cause that affects multiple organs. To date, only isolated cases of extrapulmonary sarcoidosis of the female reproductive tract, which rarely affects postmenopausal women, have been reported.

METHODS

We describe the case of a postmenopausal woman with sarcoidosis of multiple structures of the genital tract accompanied by pulmonary involvement. A review of the literature was performed to examine the role of sex hormones in the pathogenesis of sarcoidosis.

RESULTS

We describe the case of a 60-year-old white, nulliparous, nulligravid postmenopausal woman with sarcoidosis of the cervix, uterus, mesosalpinx, and right ovary, accompanied by pulmonary involvement. The diagnosis was based on the identification of noncaseating granulomas in reproductive tract organs. Although imaging methods (high-resolution CT and chest x-ray) and pulmonary function tests did not reveal any abnormality, lung involvement was confirmed histologically by transbronchial biopsy. Treatment with steroids was successful and led to normalization of serum biomarker (serum angiotensin-converting enzyme, soluble interleukin-2 receptor, and neopterin) levels.

CONCLUSIONS

This particular case and a brief literature review of female genital tract sarcoidosis in postmenopausal women suggest the role of sex hormones in the pathogenesis of sarcoidosis. Hormone therapy may be a prospective therapeutic alternative to corticosteroids in postmenopausal women.

A pooled multisite analysis of the effects of female reproductive hormones on glioma risk

PURPOSE

The association between female reproductive factors and glioma risk is unclear, but most published studies have been limited by small sample size. We conducted a pooled multisite study of pre- and postmenopausal women, investigating the effect of female reproductive factors, including hormonal medications.

METHODS

Unconditional logistic regression was used to calculate odds ratios (ORs) and 95 % confidence intervals (95 % CIs) assessing the effects of female reproductive factors and female hormonal medications in glioma cases and unrelated controls.

RESULTS

Menarche over the age of 15 as compared to under 12 was associated with a statistically significant risk for glioma (OR 2.00, 95 % CI 1.47-2.71). Use of oral contraceptive pills (OCP) was inversely associated with risk of glioma (OR 0.61, 95 % CI 0.50-0.74), and there was an inverse trend with longer duration of OCP use (p for trend <0.0001). Use of hormone replacement therapy (HRT) was also inversely associated with risk of glioma (OR 0.55, 95 % CI 0.44-0.68), and there was an inverse trend with longer duration of use (p for trend <0.0001). Compared to those reporting neither OCP use nor HRT use, those who reported using both were less likely to have a diagnosis of glioma (OR 0.34, 95 % CI 0.24-0.48).

CONCLUSIONS

Female reproductive hormones may decrease the risk for glioma. The association appears to be strongest with greater length of use and use of both HRT and OCP.

Menstrual cycle and detectable human papillomavirus in reproductive-age women: a time series study

BACKGROUND

Current evidence on the relationship between human papillomavirus (HPV) DNA detection and menstrual cycle has been inconsistent.

METHODS

We included 21 nonoral contraceptive pill (non-OCP) users who self-collected vaginal samples twice per week for 16 weeks. We explored whether variable detection of HPV DNA exhibited cyclic or other structured temporal patterns. We also evaluated relationships between serial HPV prevalence, sexual behavior, and suspected bacterial vaginosis (BV) as defined by Nugent Gram stain score ≥7.

RESULTS

During follow-up, any-type HPV prevalence varied between 61.1% and 85.0%. Although not statistically significant, we observed a maximum autocorrelation in serial HPV prevalence lagging 14 days (correlation coefficient [ρ], -0.24). Any-type HPV detection had a periodic behavior, generally repeating every 28.0 days (bootstrapped interquartile range, 22.4-28.0) and peaking around the ovulation time (adjusted odds ratio, 1.96; 95% confidence interval [CI], 1.06-3.62) as compared to menstruation. We also showed that an increase in any-type HPV prevalence preceded the beginning of a menstrual cycle by 9-12 days. There was no evidence of relationships between HPV prevalence and sexual activity or Nugent score.

CONCLUSIONS

Serially detected any-type HPV DNA showed a periodic behavior and was likely to peak in the periovulatory phase among non-OCP users.

The influence of sex and gender on the immune response

The immune system and its orchestrated response are affected by a multitude of endogenous and exogenous factors, modulators and challenges. One of the most frequent differences described in the immune response is its vigor and activity in females compared to males, leading to the consequent increase in autoimmune conditions seen in the female population as well as differences in the immune response to pathogens and viruses. The following review summarizes our present knowledge on sex differences in the immune response, detailing the hormonal and genetic effects that have been proposed as explanatory mechanisms. Sexual hormones, mostly estrogen but also progesterone and testosterone, affect immune cells quantitatively and qualitatively. Relevant research has focused on the impact of hormones on cytokine production by the different effector cells, as well as impact on immunoglobulin production by B lymphocytes and activity of granulocytes and NK cells. The biological aspects are complemented by research data on the possible modulatory role of the X chromosome. In addition to biological differences, the frequently neglected role of gender as an immunomodulator is introduced and explored. Gender affects all areas of human life and consequently affects the different steps of an immune response. Exposure to various types of antigens, access to health promotion programs and health care, as well as prioritization of health needs and household resource allocation all affect the different response of females and males to immunologic challenges.

Effects of raloxifene on the production of cytokines in stimulated whole blood in ex vivo and in vitro studies

PURPOSE

The aims of this study were to determine the effects of raloxifene therapy on production of cytokines and in vitro effects of raloxifene on production of cytokines by whole blood cultures.

METHODS

We obtained samples of peripheral blood from 6 postmenopausal women with osteopenia at baseline and after 3 and 6 months of raloxifene therapy and 10 postmenopausal women who did not receive raloxifene therapy. Whole blood from raloxifene-treated women was stimulated with lipopolysaccharide (LPS) or phytohemeagglutinin (PHA). Whole blood from postmenopausal women who were not treated with raloxifene was preincubated with raloxifene at concentrations of 10(-10)-10(-7) M and then stimulated with LPS or PHA. Concentrations of IL-1β, IL-4, IL-6, IL-12p40, IL-12p70, TNF-α and IFN-γ in the supernatant were measured by respective ELISAs.

RESULTS

In ex vivo cultures, raloxifene therapy inhibited LPS-stimulated production of IL-1β, IL-6, IL-12p40, IL-12p70 and TNF-α, but not PHA-stimulated production of IL-4 and IFN-γ. In in vitro cultures, raloxifene at a concentration (10(-9) M) inhibited LPS-stimulated production of IL-1β, IL-6 and IL-12p40 and PHA-stimulated production of IFN-γ.

CONCLUSIONS

Raloxifene therapy decreases the production of IL-1β, IL-6, IL-12 and TNF-α but not that of IL-4 and IFN-γ, suggesting that modulation of cytokines could play a role in the mechanisms of the osteoprotective effect of raloxifene.

Sex hormones alter Th1 responses and enhance granuloma formation in the lung

BACKGROUND

The lung is one of the sites of granulomatous responses, which are characterized by the recruitment and organization of activated macrophages and lymphocytes. There have been several reports that have shown that some pulmonary granulomatous diseases, such as sarcoidosis and nontuberculous mycobacterial disease, are likely to be characterized by a preponderance in postmenopausal females. Although sex hormones have been shown to play an important role in the regulation of the immune system, the influence of sex hormones on pulmonary granuloma formation is still unclear.

OBJECTIVES

The purpose of this study was to assess whether sex hormones are involved in granulomatous inflammation and to evaluate how sex hormones modulate this response in the lung.

METHODS

Ovariectomized rats were used as an experimental postmenopausal model in which chronic pulmonary granulomatous inflammation was induced by intravenous injection of complete Freund's adjuvant.

RESULTS

Histological analysis of lung tissues demonstrated enhancement of granuloma formation in the ovariectomized group. Such enhanced granuloma formation was significantly associated with generalized Th1-biased cytokine production in the bronchoalveolar lavage fluid.

CONCLUSION

These results indicate that sex hormones play an important role in pulmonary granuloma formation by altering the Th1 responses.

Endocrine immune interactions in human parturition

Human parturition is an inflammatory event, modulated and influenced by a host of other environmental and physiological processes, including the endocrine hormones. Complex bidirectional communication occurs between the two systems to bring about some of the changes that are seen in labour, an event that is not yet fully understood. Preterm birth is a major problem in obstetrics and neonatology, with dysfunctional labour or prolonged pregnancy also making increasingly significant contributions to maternal morbidity. With better understanding of normal and abnormal parturition we may be able to develop novel ways of treating these complications of pregnancy and reduce maternal and neonatal morbidity and mortality. This review discusses the crucial role that endocrine-immune interaction plays in the process of labour and in the processes of abnormal and preterm labour. We propose that amongst these complex interactions it is the immune system that is the driving force behind human parturition.

Sex hormones and autoimmunity

Autoimmune diseases occur more in women than in men, and this may be attributable to the role of estrogens. Androgens promote autoimmune diseases with a profile of type 1 cytokines, such as rheumatoid arthritis, whereas estrogens promote autoimmune diseases with a type 2 cytokine profile, like systemic lupus erythematosus. Both androgens and estrogens regulate the Th1/Th2 balance. Type 1 autoimmune diseases are improved when decrease type 1 cytokines (i.e. during fasting), or when there is a rise in type 2 cytokines (increased estrogens, as in pregnancy). Type 2 autoimmune diseases improve when type 2 cytokines are diminished (decreased estrogen, as in post-partum period) or when type 1 response is stimulated.

Estrogen receptor signaling and its relationship to cytokines in systemic lupus erythematosus

Dysregulation of cytokines is among the main abnormalities in Systemic Lupus Erythematosus (SLE). However, although, estrogens, which are known to be involved in lupus disease, influence cytokine production, the underlying molecular mechanisms remain poorly defined. Recent evidence demonstrates the presence of estrogen receptor in various cell types of the immune system, while divergent effects of estrogens on the cytokine regulation are thought to be implicated. In this paper, we provide an overview of the current knowledge as to how estrogen-induced modulation of cytokine production in SLE is mediated by the estrogen receptor while simultaneously clarifying various aspects of estrogen receptor signaling in this disease. The estrogen receptor subtypes, their structure, and the mode of action of estrogens by gene activation and via extranuclear effects are briefly presented. Results regarding the possible correlation between estrogen receptor gene polymorphisms and quantitative changes in the receptor protein to SLE pathology and cytokine production are reviewed.

Progesterone and 17beta-estradiol enhance regulatory responses to human papillomavirus type 16 virus-like particles in peripheral blood mononuclear cells from healthy women

Human papillomavirus (HPV) virus-like particle (VLP) vaccines are highly effective at preventing viral infections and the development of precancerous lesions through the induction of high-titer neutralizing antibodies and strong cell-mediated immune responses. Women taking combined oral contraceptives (COCs), however, show large variabilities in the magnitudes of their antibody responses. The goal of the present study was to determine the effects of 17beta-estradiol (E2) and progesterone (P4) alone and in combination on the cellular immune response to HPV type 16 (HPV-16) VLPs in vitro. Peripheral blood mononuclear cells (PBMCs) from healthy donor women were stimulated in vitro with HPV-16 VLPs (2.5 microg/ml) in the presence of E2 and P4 administered either alone or in combination; and lymphoproliferation, cytokine production, transcription factor expression, and steroid hormone receptor expression were analyzed. HPV-16 VLPs significantly increased the levels of lymphoproliferation, proinflammatory cytokine (gamma interferon [IFN-gamma], interleukin-1beta [IL-1beta], IL-2, IL-6, IL-8, IL-12p70, IL-17, tumor necrosis factor alpha [TNF-alpha]) production, anti-inflammatory cytokine (IL-1ra, IL-10) production, and the expression of Eralpha and Erbeta but decreased the levels of Foxp3 expression and production of transforming growth factor beta (TGF-beta). Exposure of PBMCs to E2 and P4 either alone or in combination significantly decreased the levels of lymphoproliferation and production of proinflammatory cytokines (IFN-gamma, IL-12p70, TNF-alpha) but increased the levels of production of IL-10 and TGF-beta and the expression of Foxp3 in response to HPV-16 VLPs. Treatment of cells with biologically relevant concentrations of sex steroid hormones suppressed the inflammatory response and enhanced the regulatory response to HPV-16 VLPs, which may have implications for predicting the long-term efficacy of HPV vaccines, adverse events, and cross-protection among women taking COCs.

Effects of estrogen replacement therapy on estrogen receptor expression and immunoregulatory cytokine secretion in surgically induced menopausal women

To investigate the effect of oral and transdermal estrogen replacement therapy (ERT) on the expression of different estrogen receptor (ER) subtypes and the secretion of immunoregulatory cytokines, we performed a clinical investigation on previously healthy women who had undergone a total hysterectomy and bilateral salpingo-oopherectomy. These women were randomly distributed into two groups: an oral ERT group and transdermal ERT group. Before and after ERT, the serum levels of estradiol (E2) and follicle stimulating hormone (FSH) were measured, ERalpha and ERbeta expression of peripheral blood T lymphocytes was tested, and secretion of specific immunoregulatory cytokines (IFNgamma, IL-2 and IL-4) by T lymphocytes was examined. Our results confirm that for both groups, the serum E2 level was increased after ERT (P<0.01) and the serum FSH level was decreased after ERT (P<0.01), with no significant difference in hormone levels between the two groups. ERalpha expression by T lymphocytes was significantly higher after ERT than before (P<0.01) in both groups. Levels of type 1 cytokines (IL-2 and IFNgamma), which were secreted by T helper 1 (Th1), after ERT were substantially decreased. The level of type 2 cytokine (IL-4), which were secreted by T helper 2 (Th2), was significantly increased after ERT (P<0.01 for the oral group and P<0.05 for the transdermal group). In summary, both oral and transdermal ERT increased serum E2 levels, decreased serum FSH levels and relieved the effects of peri-menopausal symptoms. These data suggest that both oral and transdermal ERT act to improve the balance of Th1/Th2 cytokines by the effects of estrogen potentially acting in T lymphocytes mainly through ERalpha.

Interleukin-4 stimulates proliferation of endometriotic stromal cells

Several lines of evidence indicate that the Th2 immune response is associated with endometriosis. Although an increased concentration of interleukin (IL)-4, a typical Th2 cytokine, has been reported in endometriotic tissues, the implication of this for endometriosis has not been determined. To investigate a possible role of IL-4 in the development of endometriosis, we examined the presence of IL-4-producing cells in endometriotic tissues and the effect of IL-4 on proliferation of endometriotic stromal cells. Endometriotic stromal cells were isolated from endometriotic tissues obtained from women undergoing surgery for endometrioma. Immunohistochemistry of endometriotic tissues revealed that IL-4-positive cells were abundant in the stroma. The effect of IL-4 on proliferation of endometriotic stromal cells was studied using cell counting and BrdU incorporation assays. IL-4 (0.1 to 10 ng/ml) significantly increased cell number and BrdU incorporation in a dose-dependent manner, and the proliferative effect of IL-4 was inhibited by anti-IL-4 receptor antibody. IL-4-induced activation of mitogen-activated protein kinases in endometriotic stromal cells was examined by Western blotting. IL-4 induced phosphorylation of p38 mitogen-activated protein kinase, stress-activated protein kinase/c-Jun kinase, and p42/44 mitogen-activated protein kinase and inhibitors of these kinases suppressed IL-4-induced proliferation of endometriotic stromal cells. These findings suggest that proliferation of endometriotic stromal cells induced by locally produced IL-4 is involved in the development of endometriosis.

T helper 1/t helper 2 cell immunity in preeclamptic twin pregnancy

Preeclampsia has been classified into two types on the basis of the T helper (Th)1/Th2 balance: Th1-predominant type and Th2 predominant type. In this study, we examined the Th1/Th2 ratio in peripheral Th cells in 11 patients with preeclamptic twin pregnancies, 11 normal (nonpreeclamptic) twin pregnancies, 11 preeclamptic singleton pregnancies, and 11 normal singleton pregnancies. The average Th1/Th2 ratio in the patients with preeclamptic twin pregnancy was 8.3 +/- 3.4 (mean +/- SD), which was similar to those in patients with normal singleton and twin pregnancies and significant lower than that in patients with preeclamptic singleton pregnancies (p = 0.003). The present results suggest that the mechanisms of preeclampsia differ between singleton and twin pregnancies.

Influence of ovarian hormones deprivation on gene expression in the lower urinary tract of rats

OBJECTIVE

Identify the influence of ovarian hormone deprivation in expression genes on the lower urinary tract of rats.

MATERIALS AND METHODS

This study deals with gene screening on lower urinary tract of rats. Fifty isogenic rats divided in two groups of twenty-five animals have their lower urinary tract surgically removed: group I, ovariectomized rats 30 days prior to surgery; group II, non-ovariectomized rats. Total RNA was isolated from bladder and urethra, and differential expression of genes was analyzed quantitative, qualitative and comparatively by array technology and RT-PCR.

RESULTS

A total of 76 candidate genes were identified as differentially expressed between the groups, 26 being lower expressed in group II, and 50 in group I. Among them, differential expression validation was confirmed by RT-PCR for three lower expressed genes in group I: Vascular Endothelial Growth Factor (VEGF), Beta-2 Microglobulin (B2M) and Cytochrome c Oxidase subunit I (COX I).

CONCLUSION

Ovarian hormone deprivation influences the expression genes on lower urinary tract. We demonstrated that a 30-day period of castration down regulate the expression of VEGF, B2M and COX I in adult rats which are involved in activities of angiogenesis, immune responses and cellular metabolism respectively.

The complex role of estrogens in inflammation

There is still an unresolved paradox with respect to the immunomodulating role of estrogens. On one side, we recognize inhibition of bone resorption and suppression of inflammation in several animal models of chronic inflammatory diseases. On the other hand, we realize the immunosupportive role of estrogens in trauma/sepsis and the proinflammatory effects in some chronic autoimmune diseases in humans. This review examines possible causes for this paradox. This review delineates how the effects of estrogens are dependent on criteria such as: 1) the immune stimulus (foreign antigens or autoantigens) and subsequent antigen-specific immune responses (e.g., T cell inhibited by estrogens vs. activation of B cell); 2) the cell types involved during different phases of the disease; 3) the target organ with its specific microenvironment; 4) timing of 17beta-estradiol administration in relation to the disease course (and the reproductive status of a woman); 5) the concentration of estrogens; 6) the variability in expression of estrogen receptor alpha and beta depending on the microenvironment and the cell type; and 7) intracellular metabolism of estrogens leading to important biologically active metabolites with quite different anti- and proinflammatory function. Also mentioned are systemic supersystems such as the hypothalamic-pituitary-adrenal axis, the sensory nervous system, and the sympathetic nervous system and how they are influenced by estrogens. This review reinforces the concept that estrogens have antiinflammatory but also proinflammatory roles depending on above-mentioned criteria. It also explains that a uniform concept as to the action of estrogens cannot be found for all inflammatory diseases due to the enormous variable responses of immune and repair systems.

Changes in serum cytokine concentrations during the menopausal transition

OBJECTIVE

The purpose of the present study was to clarify the changes in serum concentrations of 17 cytokines in healthy women during the menopausal transition by using a multiplexed cytokine assay and to clarify the associations of these cytokines with serum estradiol concentration.

METHODS

Sixteen premenopausal, 54 perimenopausal and 52 postmenopausal women were enrolled in this study. Seventeen cytokines in serum samples were measured simultaneously using a Bio-Plex human cytokine 17-Plex assay.

RESULTS

Serum IL-6 concentration showed a weak positive correlation with age (r=0.196, p<0.05). Postmenopausal women for whom less than 5 years had passed since menopause showed significant (p<0.05) increase in serum concentrations of IL-2, GM-CSF and G-CSF, while serum IL-4 concentration was significantly (p<0.05) increased in postmenopausal women for whom more than 5 years had passed since menopause. Serum estradiol concentration showed a significant negative correlation with serum IL-6 concentration and weak negative correlations with serum concentrations of IL-2, IL-8 and GM-CSF.

CONCLUSION

We were able to simultaneously measure the levels of 17 cytokines using a highly sensitive cytokine assay, and we found that the changes in serum cytokine concentrations during the menopausal transition differed. We also found that serum IL-6 concentration during the menopausal transition was negatively correlated with serum estradiol concentration.

TNFalpha mediates the skeletal effects of thyroid-stimulating hormone

We have shown recently that by acting on the thyroid-stimulating hormone (TSH) receptor (TSHR), TSH negatively regulates osteoclast differentiation. Both heterozygotic and homozygotic TSHR null mice are osteopenic with evidence of enhanced osteoclast differentiation. Here, we report that the accompanying elevation of TNFalpha, an osteoclastogenic cytokine, causes the increased osteoclast differentiation. This enhancement in TSHR-/- and TSHR+/- mice is abrogated in compound TSHR-/-/TNFalpha-/- and TSHR+/-/TNFalpha+/- mice, respectively. In parallel studies, we find that TSH directly inhibits TNFalpha production, reduces the number of TNFalpha-producing osteoclast precursors, and attenuates the induction of TNFalpha expression by IL-1, TNFalpha, and receptor activator of NF-kappaB ligand. TSH also suppresses osteoclast formation in murine macrophages and RAW-C3 cells. The suppression is more profound in cells that overexpress the TSHR than those transfected with empty vector. The overexpression of ligand-independent, constitutively active TSHR abrogates osteoclast formation even under basal conditions and in the absence of TSH. Finally, IL-1/TNFalpha and receptor activator of NF-kappaB ligand fail to stimulate AP-1 and NF-kappaB binding to DNA in cells transfected with TSHR or constitutively active TSHR. The results suggest that TNFalpha is the critical cytokine mediating the downstream antiresorptive effects of TSH on the skeleton.

Spotlight on the role of hormonal factors in the emergence of autoreactive B-lymphocytes

Pathogenic autoimmunity requires a combination of inherited and acquired factors. In as much as hormones influence the sexual dimorphism of the immune system, it is possible that they can initiate or accelerate an autoimmune process, and contribute to gender-biased autoimmune disorders. Not only natural hormones, but also endocrine disruptors, such as environmental estrogens, may act in conjunction with other factors to override immune tolerance to self-antigens. In lupus, murine and human studies demonstrate that female sex hormones are implicated in disease pathogenesis. In the B cell compartment, both prolactin and estrogen are immunomodulators that affect maturation, selection and antibody secretion. Their impact may be based on their capacity to allow autoreactive B cells to escape the normal mechanisms of tolerance and to accumulate in sufficient numbers to cause clinically apparent disease. Both hormones lead to the survival and activation of autoreactive B cells, but they skew B cell maturation towards different directions, with prolactin inducing T cell-dependent autoreactive follicular B cells and estrogen eliciting T cell-independent autoreactive marginal zone B cells. Differential modulation of the cytokine milieu by hormones may also affect the development and activation of specific mature B cell subsets. This novel insight suggests that targeted manipulation of these pathways may represent a promising avenue in the treatment of lupus and other gender-biased autoimmune diseases.

Sex hormones and the immune response in humans

In addition to their effects on sexual differentiation and reproduction, sex hormones appear to influence the immune system. This results in a sexual dimorphism in the immune response in humans: for instance, females produce more vigorous cellular and more vigorous humoral immune reactions, are more resistant to certain infections, and suffer a higher incidence of autoimmune diseases. Disease expression is also affected by the reproductive status of the female. As sex steroids--estrogens, progesterone and testosterone--differ between gender and within different reproductive stages, a lot of research has focussed on the effects of sex hormones on immune responses. Although there is also a vast literature on the effects of sex hormones on immune responses in animals, in this review we will focus on the most intriguing effects and mechanisms by which sex hormones affect different components of the immune system in humans.

Effects of Bak Foong Pills and Menoease Pills on white blood cell distribution in old age female rats

This study examined the effects of Bak Foong Pills (BFP) and the new BFP-derived post-menopause formula, Menoease Pills (MBFP), on the distribution of peripheral white blood cells (WBC) between BFP/MBFP-treated and non-treated rats. Eighteen months old female SD rats were used to mimic post-menopausal and old age animal models. The percentage distribution of lymphocytes, monocytes and granulocytes were measured using flow cytometry with and without treatments of BFP or MBFP. Results showed that WBC distribution in old age rats were significantly different from that of adult rats, suggesting that as the animal aged, their WBC distributions were altered. Old age rats were observed to have much lower percentages of lymphocytes, but higher percentages of granulocytes when compared to the adult rats, indicating possible attenuated immunity. Following treatment with BFP or MBFP, WBC populations were found to be redistributed back into the ranges observed in adult animals. Furthermore, MBFP, was found to alter WBC distribution in a dose-dependent manner. When compared to estrogen (E(2)), a well documented regulator of immune function, results showed that MBFP was able to show significantly greater effects on WBC redistribution compared to E(2). However, in ovariectomised (ovx) old age rats, neither MBFP nor E(2) treated groups showed any changes in WBC redistribution. These results indicate that MBFP may share similarities to E(2). Indeed, the effect of MBFP and E(2) seems to require intact ovaries, which are believed to be necessary for the modulation of WBC distributions and immune functions. Overall, our findings suggest that BFP and MBFP may be able to regulate WBC population in old age female rats, and thus, indicate their potential role on improving the attenuated immunity evident in post-menopausal and elderly women.

Estrogen replacement raises rat CRP without evidence of complement activation

Given current controversies regarding anti- and pro-inflammatory effects of estrogen, there is a need to explore relationships between gonadal hormones and inflammation using appropriate animal models. It has been proposed that rats are not appropriate for such research since, contrary to the effect of estrogen in humans, earlier animal studies had reported that estrogen downregulates serum C-reactive protein (rCRP) levels in the rat. With these considerations in mind, we re-examined the effects of estrogen withdrawal and replacement on CRP expression and complement activation in the rat. F-344 rats underwent bilateral ovariectomy or sham surgery at 9-10 months of age. Four months later, ovariectomized rats were treated with traditional high-dose 17beta-estradiol (Hi-E2) capsules, lower-dose (Lo-E2) 17beta-estradiol capsules, or placebo capsules for 7 days prior to sacrifice. Levels of plasma rat C-reactive protein (rCRP) were significantly lower in ovariectomized vs. sham-operated animals (415.5 +/- 10.6 vs. 626.6 +/- 23.0 mg/L, p < 0.001). Estrogen replacement significantly raised rCRP levels in ovariectomized animals (690.0 +/- 28.0 mg/L in Lo-E2 and 735.5 +/- 35.8 mg/L in Hi-E2, respectively, p < 0.001). Plasma rCRP levels correlated significantly with both hepatic rCRP (r = 0.79, p < 0.001) and serum estradiol (r = 0.70, p < 0.001) levels. However, no significant differences were observed in indices of complement activation (C4b/c) or CRP-complement complex generation (rCRP-C3 complex). In the mature female rat, ovariectomy reduces and estrogen replacement raises rCRP. Effects of estrogen on plasma rCRP induction are mediated, at least in part, through hepatic mechanisms and do not appear to require or be associated with complement activation.

Tumor necrosis factor-α: molecular and cellular mechanisms in skeletal pathology

Tumor necrosis factor-alpha (TNF) is one member of a large family of inflammatory cytokines that share common signal pathways, including activation of the transcription factor nuclear factor kappa B (Nf-kappa B) and stimulation of the apoptotic pathway. Data derived from early work supported a role for TNF as a skeletal catabolic agent that stimulates osteoclastogenesis while simultaneously inhibiting osteoblast function. The finding that estrogen deficiency was associated with increased production of cytokines led to a barrage of studies and lively debate on the relative contributions of TNF and other cytokines on bone loss, on the potential cell sources of TNF in the bone microenvironment, and on the mechanism of TNF action. TNF has a central role in bone pathophysiology. TNF is necessary for stimulation of osteoclastogenesis along with the receptor activator of Nf-kappa B ligand (RANKL). TNF also stimulates osteoblasts in a manner that hinders their bone-formative action. TNF suppresses recruitment of osteoblasts from progenitor cells, inhibits the expression of matrix protein genes, and stimulates expression of genes that amplify osteoclastogenesis. TNF may also affect skeletal metabolism by inducing resistance to 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) by a mechanism that extends to other members of the steroid hormone nuclear receptor family. Thus, TNF assails bone at many levels. This review will focus on the cellular and molecular mechanisms of TNF action in the skeleton that result in increased bone resorption and impaired formation. TNF and its signal pathway remains an important target for the development of new therapies for bone loss from osteoporosis and inflammatory arthritis.