Estrogen regulates cytokine production and apoptosis in PMA-differentiated, macrophage-like U937 cells

Associations between maternal serum phytoestrogens and liver function markers: a cross-sectional study from China

Phytoestrogens (PEs) may harm liver function. However, studies in pregnant women are limited. Our study was conducted in pregnant women to assess the effect of serum PEs on liver function markers. We conducted a cross-sectional study focusing in the first trimester of pregnancy. A total of 352 pregnant women were enrolled in the study. We used generalized linear model (GLM) to explore the associations between each PE and each marker of liver function. We used Quantile g-computation (Qgcomp) and Bayesian kernel machine regression (BKMR) models to explore the associations between mixed exposure to all PEs and liver function markers. The GLM results showed that equol (EQU), daidzein (DAD), genistein (GEN), enterolactone (ENT), and enterodiol (END) were negatively correlated with albumin (ALB). DAD and GEN were associated with elevated alanine aminotransferase (ALT). DAD, GEN, naringin (NAR), and glycitein (GLY) were related to elevated aspartate aminotransferase (AST). Mixed exposure model results showed that the mixture of PEs was associated with reduced ALB. Our results support the existence of associations between PEs and maternal liver function in the first trimester. Emphasizing the detrimental associations between serum PEs and liver function in pregnant women is essential to ensure maternal liver health during pregnancy.

Regulatory Roles of Estrogens in Psoriasis

Psoriasis is a common chronic inflammatory skin disease of the interleukin (IL)-23/IL-17 axis. The severity of psoriasis has been reported as higher in men than in women. The immunoregulatory role of female sex hormones has been proposed to be one of the factors responsible for sex differences. Among female sex hormones, estrogens have been suggested to be significantly involved in the development of psoriasis by various epidemiological and in vitro studies. For example, the severity of psoriasis is inversely correlated with serum estrogen levels. In vitro, estrogens suppress the production of psoriasis-related cytokines such as IL-1β and IL-23 from neutrophils and dendritic cells, respectively. Furthermore, a recent study using a mouse psoriasis model indicated the inhibitory role of estrogens in psoriatic dermatitis by suppressing IL-1β production from neutrophils and macrophages. Understanding the role and molecular mechanisms of female sex hormones in psoriasis may lead to better control of the disease.

Gradient Boosting Machine Learning Model for Defective Endometrial Receptivity Prediction by Macrophage-Endometrium Interaction Modules

Background

A receptive endometrium is a prerequisite for successful embryo implantation. Mounting evidence shows that nearly one-third of infertility and implantation failures are caused by defective endometrial receptivity. This study pooled 218 subjects from multiple datasets to investigate the association of the immune infiltration level with reproductive outcome. Additionally, macrophage-endometrium interaction modules were constructed to explore an accurate and cost-effective approach to endometrial receptivity assessment.

Methods

Immune-infiltration levels in 4 GEO datasets (n=218) were analyzed and validated through meta-analysis. Macrophage-endometrium interaction modules were selected based on the weighted gene co-expression network in GSE58144 and differentially expressed genes dominated by GSE19834 dataset. Xgboost, random forests, and regression algorithms were applied to predictive models. Subsequently, the efficacy of the models was compared and validated in the GSE165004 dataset. Forty clinical samples (RT-PCR and western blot) were performed for expression and model validation, and the results were compared to those of endometrial thickness in clinical pregnancy assessment.

Results

Altered levels of Mϕs infiltration were shown to critically influence embryo implantation. The three selected modules, manifested as macrophage-endometrium interactions, were enrichment in the immunoreactivity, decidualization, and signaling functions and pathways. Moreover, hub genes within the modules exerted significant reproductive prognostic effects. The xgboost algorithm showed the best performance among the machine learning models, with AUCs of 0.998 (95% CI 0.994-1) and 0.993 (95% CI 0.979-1) in GSE58144 and GSE165004 datasets, respectively. These results were significantly superior to those of the other two models (random forest and regression). Similarly, the model was significantly superior to ultrasonography (endometrial thickness) with a better cost-benefit ratio in the population.

Conclusion

Successful embryo implantation is associated with infiltration levels of Mϕs, manifested in genetic modules involved in macrophage-endometrium interactions. Therefore, utilizing the hub genes in these modules can provide a platform for establishing excellent machine learning models to predict reproductive outcomes in patients with defective endometrial receptivity.

Perimenstrual Asthma in Adolescents: A Shared Condition in Pediatric and Gynecological Endocrinology

Asthma is a frequent medical condition in adolescence. The worsening of the most common symptoms perimenstrually is defined as perimenstrual asthma (PMA). The cause of PMA remains unclear, but a role for hormonal milieu is plausible. Data on PMA in adolescents are limited, and its management is not fully established. We aimed to discuss the PMA phenomenon in young females from pathophysiology to preventive strategies, focusing on the relationship with the hormonal pattern. The fluctuation of estrogens at ovulation and before menstruation and the progesterone secretion during the luteal phase and its subsequent withdrawal seem to be the culprits, because the deterioration of asthma is cyclical during the luteal phase and/or during the first days of the menstrual cycle. Conventional asthma therapies are not always effective for PMA. Preventive strategies may include innovative hormonal contraception. Even a possible beneficial effect of other hormonal treatments, including estrogens, progestogens, and androgens, as well as leukotriene receptor antagonists and explorative approach using microbial-directed therapy, is considered. The underlying mechanisms, through which sex-hormone fluctuations influence asthma symptoms, represent a challenge in the clinical management of such a distressing condition. Further studies focused on young females are mandatory to promote adolescent health.

Epicutaneous Administration of 17β-Estradiol Induces Langerhans Cells Depletion

BACKGROUND

Langerhans cells (LC) number and function in mouse vaginal mucosa are affected by 17β-estradiol (E₂) application; nonetheless, its effect on epidermal LC has not been studied. The purpose of this study was to evaluate the effect of topical administration of E₂ on the number, phenotype, and migratory ability of LC in mouse skin.

METHODS

Ears of adult CD1 male mice were topically treated once with several doses. Immunohistochemical staining for CD207 and TUNEL staining were performed. LC migration to lymph nodes and the effect on the expression of costimulatory molecules on cultured dendritic cells (DC) were also evaluated.

RESULTS

E₂ decreased the number of CD207+ LC in a dose-dependent manner. One hour after treatment, 1 and 10 µg/mL E₂ significantly reduced the LC number by 21% and 26%, respectively, after two hours, the reduction was 23% and 41%, respectively. After 48 hours, LC recovered, and after 96 hours of treatment, the CD207+/MHCII+ DC numbers were increased in regional lymph nodes. However, CD86 and CD40 molecules were expressed at lower levels than in positive control. The TUNEL assay did not show apoptotic cells. Furthermore, in cultured DC, E₂ promoted a decrease in CD40 and CD86 expression and an increase in CD273, CD274, MHCII, and CCR7.

CONCLUSIONS

The topical administration of E₂ induced a transitory local diminution of LC population and a tolerogenic phenotype. This decrease in epidermal LC suggests that E₂ may affect skin immune responses, inducing an inhibitory response, which should be considered when prescribing topical E₂ medications.

Concurrent and Longitudinal Associations of Sex and Race with Inflammatory Biomarkers during Adolescence

Chronic, systemic inflammation is implicated in physical and mental health; little is known about whether sex and racial differences detected in adulthood are observed during adolescence or about normative changes occurring during adolescence. This longitudinal, United States-based study examined four biomarkers of systemic inflammation [C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and IL-8) in 315 adolescents (51% female; 58% black; baseline age = 16.49 years (SD = 1.56; range: 12.14-21.28)] at three timepoints. Notable results included: general decline in inflammatory biomarkers in older adolescents, lower levels of TNF-α/IL-8 in black adolescents, elevated CRP/IL-6 in females, and especially higher levels of IL-6 in black, female adolescents. Implications are discussed, particularly the potential health implications of elevated IL-6 in black females.

Androgen and Androgen Receptors as Regulators of Monocyte and Macrophage Biology in the Healthy and Diseased Lung

Androgens, the predominant male sex hormones, drive the development and maintenance of male characteristics by binding to androgen receptor (AR). As androgens are systemically distributed throughout the whole organism, they affect many tissues and cell types in addition to those in male sexual organs. It is now clear that the immune system is a target of androgen action. In the lungs, many immune cells express ARs and are responsive to androgens. In this review, we describe the effects of androgens and ARs on lung myeloid immune cells-monocytes and macrophages-as they relate to health and disease. In particular, we highlight the effect of androgens on lung diseases, such as asthma, chronic obstructive pulmonary disease and lung fibrosis. We also discuss the therapeutic use of androgens and how circulating androgens correlate with lung disease. In addition to human studies, we also discuss how mouse models have helped to uncover the effect of androgens on monocytes and macrophages in lung disease. Although the role of estrogen and other female hormones has been broadly analyzed in the literature, we focus on the new perspectives of androgens as modulators of the immune system that target myeloid cells during lung inflammation.

Bosutinib Acts as a Tumor Inhibitor via Downregulating Src/NF-κB/Survivin Expression in HeLa Cells

Efforts have been made to find effective medical drugs for cervical cancer treatment. The incidence of cervical cancer ranks second among women, and is a serious threat to women's health. Aberrant activation of the nonreceptor protein tyrosine kinases such as Src is commonly observed in progressive stages of human tumors. Thus, targeting Src kinase could be a promising strategy for cervical cancer therapy. In this study, we explored the potential utility of bosutinib in the treatment of cervical cancer. We found that bosutinib, as a potent dual Src/Abl inhibitor, could exert anti-tumor effects on cervical cancer. Bosutinib inhibited cervical cancer cells proliferation and colony formation ability in a dose-dependent manner, and also induced apoptosis. Mechanistically, bosutinib effectively decreased the activity of Src/NF-κB/survivin signaling pathway. Our study provided a biological rationale to test bosutinib as a valuable therapeutic option for cervical cancer patients. Anat Rec, 302:2193-2200, 2019. © 2019 American Association for Anatomy.

Role of Macrophages in Pregnancy and Related Complications

Macrophages (MФs) are the leukocytes produced from differentiation of monocytes and are located in almost all tissues of human body. They are involved in various processes, such as phagocytosis, innate and adaptive immunity, proinflammatory (M1) and anti-inflammatory (M2) activity, depending on the tissue microenvironment. They play a crucial role in pregnancy, and their dysfunction or alteration of polarity is involved in pregnancy disorders, like preeclampsia, recurrent spontaneous abortion, infertility, intrauterine growth restriction, and preterm labor. About 50-60% of decidual leukocytes are natural killer (NK) cells followed by MФs (the second largest population). MФs are actively involved in trophoblast invasion, tissue and vascular remodeling during early pregnancy, besides their role as major antigen-presenting cells in the decidua. These cells have different phenotypes and polarities in different stages of pregnancy. They have also been observed to enhance tumor growth by their anti-inflammatory activity (M2 type) and prevent immunogenic rejection. Targeted alteration of polarity (M1-M2 or vice versa) could be a major focus in the future treatment of pregnancy complications. This review is focused on the role of MФs in pregnancy, their involvement in pregnancy disorders, and decidual MФs as possible therapeutic targets for the treatment of pregnancy complications.

Immunotoxicity of estrogen and nonylphenol on apoptosis and expression of ERs in goldfish macrophage: Opening new avenue for discovering the role of experimental model systems and sexes

The expression of estrogen receptors (ERs) and their roles in important cell processes such as apoptosis in the macrophages exposed to estrogen/xenoestrogen have remained a complex secret. This study focused on the expression of estrogen receptors (ERs) and the stimulation of apoptosis in the macrophages from the two sexes of goldfish (Carassius auratus) exposed to 17-βestradiol (E2) and nonylphenol (NP) under in vivo and in vitro conditions. For the in vivo experiment, fish were exposed to NP (10^-6 M and 10^-7 M) and E2 (10^-6 M) for 24 days. Then, the head kidney macrophages from the male and the female goldfish were isolated and assayed. For the in vitro experiments, the macrophages derived from the two sexes were cultured in L-15 medium and exposed to E2 (150 nM) and NP (10 nM and 150 nM) for 3 days. The results showed that the three isoforms of ERs (ERα, ERβ₁, ERβ₂) were expressed in the goldfish macrophages. After the exposure of macrophages to NP and E2, sex-specific increase of ERs expression and apoptosis were observed (P < 0.05). The expression of ERα after NP treatment showed the highest alteration, with the response being concentration-dependent. The most alteration of ERs expression were observed in the in vivo experiment. This study provides insight to understand how exposure of the goldfish macrophages to E2 and NP can up-regulate the transcript levels of estrogen receptor subtypes and stimulate apoptosis.

TFOS DEWS II Sex, Gender, and Hormones Report

One of the most compelling features of dry eye disease (DED) is that it occurs more frequently in women than men. In fact, the female sex is a significant risk factor for the development of DED. This sex-related difference in DED prevalence is attributed in large part to the effects of sex steroids (e.g. androgens, estrogens), hypothalamic-pituitary hormones, glucocorticoids, insulin, insulin-like growth factor 1 and thyroid hormones, as well as to the sex chromosome complement, sex-specific autosomal factors and epigenetics (e.g. microRNAs). In addition to sex, gender also appears to be a risk factor for DED. "Gender" and "sex" are words that are often used interchangeably, but they have distinct meanings. "Gender" refers to a person's self-representation as a man or woman, whereas "sex" distinguishes males and females based on their biological characteristics. Both gender and sex affect DED risk, presentation of the disease, immune responses, pain, care-seeking behaviors, service utilization, and myriad other facets of eye health. Overall, sex, gender and hormones play a major role in the regulation of ocular surface and adnexal tissues, and in the difference in DED prevalence between women and men. The purpose of this Subcommittee report is to review and critique the nature of this role, as well as to recommend areas for future research to advance our understanding of the interrelationships between sex, gender, hormones and DED.

Aromatase and regulation of the estrogen-to-androgen ratio in synovial tissue inflammation: common pathway in both sexes

Sex hormones play an active role in inflammatory responses, with androgens being anti-inflammatory, whereas estrogens have both pro- and anti-inflammatory effects. In rheumatoid arthritis (RA) patients, low levels of androgens and high levels of estrone are found in the synovial fluid. Aromatase is the key enzyme for the conversion of androgens into estrogens. Proinflammatory cytokines stimulate aromatase activity so that the inflammatory milieu can induce conversion of androgens to estrogens. Moreover, testosterone inhibits aromatase activity. As local androgen levels are low in RA, this can contribute to high aromatase activity in the synovium. Importantly, aromatase-converted estrogens are converted into proproliferative and proinflammatory 16-hydroxylated estrogens. A hormone involved in aromatase activity is vitamin D, which downregulates aromatase in human RA macrophages. Collectively, evidence suggests a key role of aromatase in sex hormone balance during chronic inflammation and points to the importance of vitamin D as a possible new tool for aromatase modulation.

Effect of estrogen on Th1, Th2 and Th17 cytokines production by proteolipid protein and PHA activated peripheral blood mononuclear cells isolated from multiple sclerosis patients

BACKGROUND AND AIMS

A large body of studies has shown that 17-β estradiol (E2) has a protective effect on susceptibility to experimental autoimmune encephalomyelitis (EAE). Clinical improvement in multiple sclerosis and its animal model, EAE, during pregnancy, when estrogen levels are high, suggests an immunomodulatory role for estrogens. The immune basis for this protection is poorly understood. In this study we evaluated the effect of E2 on the synthesis of inflammatory, antiinflammatory and regulatory cytokines.

METHODS

We analyzed the effect of E2 on IL-4, IL-10, IL-17, TNF-α and IFN-γ cytokines produced by proteolipid protein (PLP) or mitogen phytohemagglutinin (PHA)-activated peripheral blood mononuclear cells isolated from multiple sclerosis patients in comparison to healthy control group. We used RT-PCR and ELISA to detect the level of cytokines.

RESULTS

We found that E2 significantly increased IL-10 expression and secretion and decreased expression of TNF-α in both groups and IL-4 in patients in cells stimulated with PLP or PHA (p <0.0001).

CONCLUSION

These data indicated that E2 could affect expression and secretion of inflammatory and anti-inflammatory cytokines and could regulate immune responses especially in the differentiation towards regulatory responses, and this finding might have therapeutic value in multiple sclerosis.

Role of the innate immunity in female reproductive tract

The mucosal immune system in the female reproductive tract (FRT) is well equipped to meet the sexually transmitted pathogens, allogeneic sperm, and the immunologically distinct fetus. Analysis of the FRT indicates that epithelial cells provide a physical barrier against pathogens and microbial infections as well as secretions containing anti-microbial peptides, cytokines, and chemokines which recruit and activate immune cells. Epithelial and immune cells confer protection in part through Toll-like receptors. The aim of this literature is to review the diverse components of the innate immune system, contributing to an exclusive protection system throughout the FRT.

Recombinant human mannose-binding lectin dampens human alveolar macrophage inflammatory responses to influenza A virus in vitro

IAV pneumonia remains a serious global health problem, and preventative and therapeutic strategies remain limited. AM are critical effector cells in the control of influenza, impairing IAV replication, promoting IAV clearance, and promoting efferocytosis and resolution of lung inflammation. MBL, an innate immune pattern recognition molecule, present in the lungs, binds IAV, and plasma MBL deficiency is associated with increased susceptibility to IAV, although the mechanism remains incompletely understood, and the influence of MBL on the IAV-AM interaction has not been established. In the current study, focusing on human macrophages (U937 cell line and clinically relevant human AM), data demonstrated that unopsonized IAV is readily internalized, induced release of TNF and ROS, and promoted macrophage apoptosis. In contrast, IAV, opsonized with rhMBL, reduced IAV uptake and macrophage apoptosis and dramatically reduced TNF release and ROS. Macrophage host-defense responses were reduced further in the presence of MASPs. Taken together, these data support the concept that rhMBL may serve a protective innate host response and a critical biological response modifier function by limiting AM inflammation, oxidative injury, and AM apoptosis, which may allow effective IAV clearance while limiting collateral damage to vital organs, such as the lungs.

Do androgen deprivation drugs affect the immune cross-talk between mononuclear and prostate cancer cells?

The aim of the study was to examine the effect of androgen deprivation drugs, i.e. leuprolide and bicalutamide on the immune cross-talk between human peripheral blood mononuclear cells (PBMC) and cells from PC-3 and LNCaP human prostate cancer lines. PBMC, PC-3 and LNCaP were separately incubated without and with two androgen-deprivation drugs, i.e. leuprolide and bicalutamide, and the secretion of IL-1β, IL-6, IL-1ra and IL-10 was examined. In addition, the effect of both drugs on the production of those cytokines was carried out after 24 hours incubation of PBMC with both types of cancer cells. Leuprolide or bicalutamide did not affect the production of the cytokines by PBMC or by the prostate cancer cells from the two lines. Incubation of PBMC with PC-3 or LNCaP cells caused increased production of IL-1β, IL-6 and IL-10 as compared with PBMC incubated without malignant cells. While 10(-7) M and 10(-8) M of leuprolide caused a decreased secretion of IL-1β by PBMC previously incubated with prostate cancer cells without the drug, bicalutamide did not affect this PBMC activity at any drug concentration. This observation suggests the existence of an additional mechanism explaining the effect of androgen deprivation therapy in prostate cancer patients.

Estrogens and atherosclerosis: insights from animal models and cell systems

Estrogens not only play a pivotal role in sexual development but are also involved in several physiological processes in various tissues including vasculature. While several epidemiological studies documented an inverse relationship between plasma estrogen levels and the incidence of cardiovascular disease and related it to the inhibition of atherosclerosis, an interventional trial showed an increase in cardiovascular events among postmenopausal women on estrogen treatment. The development of atherosclerotic lesions involves complex interplay between various pro- or anti-atherogenic processes that can be effectively studied only in vivo in appropriate animal models. With the advent of genetic engineering, transgenic mouse models of atherosclerosis have supplemented classical dietary cholesterol-induced disease models such as the cholesterol-fed rabbit. In the last two decades, these models were widely applied along with in vitro cell systems to specifically investigate the influence of estrogens on the development of early and advanced atherosclerotic lesions. The present review summarizes the results of these studies and assesses their contribution toward better understanding of molecular mechanisms underlying anti- and/or pro-atherogenic effects of estrogens in humans.

Secreted human glycyl-tRNA synthetase implicated in defense against ERK-activated tumorigenesis

Although adaptive systems of immunity against tumor initiation and destruction are well investigated, less understood is the role, if any, of endogenous factors that have conventional functions. Here we show that glycyl-tRNA synthetase (GRS), an essential component of the translation apparatus, circulates in serum and can be secreted from macrophages in response to Fas ligand that is released from tumor cells. Through cadherin (CDH)6 (K-cadherin), GRS bound to different ERK-activated tumor cells, and released phosphatase 2A (PP2A) from CDH6. The activated PP2A then suppressed ERK signaling through dephosphorylation of ERK and induced apoptosis. These activities were inhibited by blocking GRS with a soluble fragment of CDH6. With in vivo administration of GRS, growth of tumors with a high level of CDH6 and ERK activation were strongly suppressed. Our results implicate a conventional cytoplasmic enzyme in translation as an intrinsic component of the defense against ERK-activated tumor formation.

Estradiol and progesterone strongly inhibit the innate immune response of mononuclear cells in newborns

Newborns are particularly susceptible to bacterial infections due to qualitative and quantitative deficiencies of the neonatal innate immune system. However, the mechanisms underlying these deficiencies are poorly understood. Given that fetuses are exposed to high concentrations of estradiol and progesterone during gestation and at time of delivery, we analyzed the effects of these hormones on the response of neonatal innate immune cells to endotoxin, bacterial lipopeptide, and Escherichia coli and group B Streptococcus, the two most common causes of early-onset neonatal sepsis. Here we show that at concentrations present in umbilical cord blood, estradiol and progesterone are as powerful as hydrocortisone for inhibition of cytokine production by cord blood mononuclear cells (CBMCs) and newborn monocytes. Interestingly, CBMCs and newborn monocytes are more sensitive to the effects of estradiol and progesterone than adult peripheral blood mononuclear cells and monocytes. This increased sensitivity is associated with higher expression levels of estrogen and membrane progesterone receptors but is independent of a downregulation of Toll-like receptor 2 (TLR2), TLR4, and myeloid differentiation primary response gene 88 in newborn cells. Estradiol and progesterone mediate their anti-inflammatory activity through inhibition of the NF-κB pathway but not the mitogen-activated protein kinase pathway in CBMCs. Altogether, these results suggest that elevated umbilical cord blood concentrations of estradiol and progesterone acting on mononuclear cells expressing high levels of steroid receptors contribute to impair innate immune responses in newborns. Therefore, intrauterine exposure to estradiol and progesterone may participate in increasing susceptibility to infection during the neonatal period.

Oestrogen modulates human macrophage apoptosis via differential signalling through oestrogen receptor-alpha and beta

Human macrophages express oestrogen receptors and are therefore competent to respond to the hormone present in their microenvironment, which is implicated in sexual dimorphism observed in several immune and autoimmune phenomena. An earlier study from this laboratory demonstrated 17beta-oestradiol (E2) induced apoptosis in macrophages derived from human peripheral blood monocytes and THP-1 acute monocytic leukaemia cell line when Bcl-2 was down-regulated; however, the involvement of E2 receptor subtypes in the modulation of death pathways in these cells remain unknown. Using macrophages derived from THP-1 human acute monocytic leukaemia cells as a model, we demonstrate that plasma membrane associated oestrogen receptor (ER) -alpha participate in E2 induced Bcl-2 increase, through activation of the mitogen activated protein kinase (MAPK) pathway whereas cytosolic ER-beta transmits signals for the pro-apoptotic event of Bax translocation. The mechanistic basis of Bax translocation comprised of ER-beta mediated increase in intracellular pH, facilitated by activation of the Na(+)-H(+) exchanger. Intracellular alkalinization accompanied by concomitant Bcl-2 increase and Bax migration does not cause cellular apoptosis; however, siRNA mediated down-regulation of ER-alpha during E2 exposure leads to inhibition of Bcl-2 increase and consequently apoptosis due to the unopposed action of mitochondrial Bax. In summary, this study underscores the importance of integrative signalling modality from multiple oestrogen receptor pools in modulating oestrogen effects on human monocyte-derived macrophage apoptotic signalling pathway, which opens new vistas to explore the use of selective oestrogen receptor modulators in apoptosis-based therapies.

IL-2 and IL-10 gene polymorphisms are associated with respiratory tract infection and may modulate the effect of vitamin E on lower respiratory tract infections in elderly nursing home residents

BACKGROUND

Vitamin E supplementation may be a potential strategy to prevent respiratory tract infections (RIs) in the elderly. The efficacy of vitamin E supplementation may depend on individual factors including specific single nucleotide polymorphisms (SNPs) at immunoregulatory genes.

OBJECTIVE

We examined whether the effect of vitamin E on RIs in the elderly was dependent on genetic backgrounds as indicated by SNPs at cytokine genes.

DESIGN

We used data and DNA from a previous vitamin E intervention study (200 IU vitamin E or a placebo daily for 1 y) in elderly nursing home residents to examine vitamin E-gene interactions for incidence of RI. We determined the genotypes of common SNPs at IL-1beta, IL-2, IL-6, IL-10, TNF-alpha, and IFN-gamma in 500 participants. We used negative binomial regression to analyze the association between genotype and incidence of infection.

RESULTS

The effect of vitamin E on lower RI depended on sex and the SNP at IL-10 -819G-->A (P = 0.03 for interaction for lower RI). Furthermore, we observed that subjects with the least prevalent genotypes at IL-2 -330A-->C (P = 0.02 for upper RI), IL-10 -819G-->A (P = 0.08 for upper RI), and IL-10 -1082C-->T (P < 0.001 for lower RI in men) had a lower incidence of RI independent of vitamin E supplementation.

CONCLUSIONS

Studies that evaluate the effect of vitamin E on RIs should consider both genetic factors and sex because our results suggest that both may have a significant bearing on the efficacy of vitamin E. Furthermore, common SNPs at cytokine genes may contribute to the individual risk of RIs in the elderly. This trial was registered at clinicaltrials.gov as NCT00758914.

Environmental toxin 4-nonylphenol and autoimmune diseases: using DNA microarray to examine genetic markers of cytokine expression

INTRODUCTION

Adverse progression of autoimmune diseases is linked to the dysregulation of cytokines. In this regard we investigated the role of 4-nonylphenol (4-NP), as a potential contributing factor in the development of immune diseases and compared it to estrogens actions since 4-NP may work via estrogen processes.

MATERIAL AND METHODS

The study made cytokine level expression changes in U937 cells by microarray technology coupled to RT PCR as a validating technique.

RESULTS

It was determined that 4-NP significantly up-regulated proinflammatory cytokine expression (toll-like-receptor [TLR]-6, TLR-10, interleukin [IL]-1, IL-5, IL-6, IL-17C, IL-23A, IL-8RB, IL-receptor-associated-kinase [IRAK-2], tumor-necrosis-factor-receptor [TNFR]-5, and TNFR-10). Estrogen caused insignificant increases but the changes parralelled that of 4-NP. Simultaneously, 4-NP down-regulated the expression of anti-inflammatory cytokines (IL-4 and IL-10), while estrogen up-regulated them.

CONCLUSIONS

4-Nonylphenol may initiate its toxic effects and pose a risk to autoimmunity-prone individuals by eliciting effects up to 4 times more potent than estrogen. Overall, exposure to 4-NP may contribute to autoimmune susceptibility and/or exacerbate existing autoimmune conditions by dys-regulating normal expression of cytokines.

17{beta}-Estradiol modulates the macrophage migration inhibitory factor secretory pathway by regulating ABCA1 expression in human first-trimester placenta

Successful pregnancy involves a series of events, most of them mediated by hormones and cytokines. Estrogens, besides being important for placental growth and embryo development, have a marked effect on the immune system exerting either pro- or anti-inflammatory properties. Numerous studies suggest that estrogens directly affect cellular function, including cytokine production. Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine involved in pregnancy, particularly during the earlier stages of placentation. Since reports on mice have shown that estrogens modulate MIF, herein we investigated the effect of estrogens on human placental MIF. By using an in vitro model of first-trimester chorionic villous explants, we found that 17beta-estradiol (E(2)) was able to modulate the release of MIF in a dose-dependent manner (10(-12) vs. 10(-9) M, P < 0.05; 10(-9) vs. 10(-5) M, P < 0.05; 10(-12) vs. 10(-5) M, P < 0.001). Unlike MIF release, no significant change in tissue MIF protein or MIF mRNA was observed. We showed evidence that E(2) concentrations (10(-9) and 10(-5) M) act on placental tissue downregulating the mRNA and protein expression of the ATP-binding cassette transporter protein A1, a membrane transporter involved in MIF secretion. These findings emphasize the mutual cooperation between hormones and cytokines and suggest that increasing estrogen levels with advancing gestation may have a major role in regulating placental MIF secretion.

Auto/paracrine control of inflammatory cytokines by acetylcholine in macrophage-like U937 cells through nicotinic receptors

Although acetylcholine (ACh) is well known for its neurotransmitter function, recent studies have indicated that it also functions as an immune cytokine that prevents macrophage activation through a 'cholinergic (nicotinic) anti-inflammatory pathway'. In this study, we used the macrophage-like U937 cells to elucidate the mechanisms of the physiologic control of cytokine production by auto/paracrine ACh through the nicotinic class of ACh receptors (nAChRs) expressed in these cells. Stimulation of cells with lipopolysaccharide up-regulated expression of alpha1, alpha4, alpha5, alpha7, alpha10, beta1 and beta3 subunits, down-regulated alpha6 and beta2 subunits, and did not alter the relative quantity of alpha9 and beta4 mRNAs. Distinct nAChR subtypes showed differential regulation of the production of pro- and anti-inflammatory cytokines. While inhibition of the expression of the TNF-alpha gene was mediated predominantly by the alpha-bungarotoxin sensitive nAChRs, that of the IL-6 and IL-18 genes-by the mecamylamine-sensitive nAChRs. Both the Mec- and alphaBtx-sensitive nAChRs regulated expression of the IL-1beta gene equally efficiently. Upregulation of IL-10 production by auto/paracrine ACh was mediated predominantly through alpha7 nAChR. These findings offer a new insight on how nicotinic agonists control inflammation, thus laying a groundwork for the development of novel immunomodulatory therapies based on the nAChR subtype selectivity of nicotinic agonists.

Dermatomyositis and cutaneous metastases from breast cancer: simultaneous development and parallel course

The association between dermatomyositis (DM) and various types of malignancies has been reported in several studies, with an estimated frequency of about 20-25%. Cancer may appear before the onset of DM, concurrently with DM or after its onset. In the present report, the occurrence of typical DM in concomitance with development of skin metastases from previously treated breast cancer is described, suggesting the role of DM as paraneoplastic marker not only in association with the primary tumor but also in case of cutaneous involvement by cancer.

Interleukin-10 promoter polymorphisms influence susceptibility to ulcerative colitis in a gender-specific manner

OBJECTIVE

Pathological evidence supports a potential role of the pro- and anti-inflammatory cytokine network in the pathogenesis of inflammatory bowel disease (IBD). Moreover, associated studies suggest a possible involvement of cytokine-related genes in IBD susceptibility. In this study, we evaluated the effect of the anti-inflammatory interleukin-10 (IL10) gene on ulcerative colitis (UC).

MATERIAL AND METHODS

Two functional single nucleotide polymorphisms (-1082 G/A, -819 T/C) in the IL10 promoter in 203 Italian sporadic UC patients and 391 controls were determined using high-resolution melting analysis.

RESULTS

The frequency of the -1082A allele was significantly higher in the UC patients than in controls (p=0.00003); -1082 genotype frequencies were also significantly different between UC patients and controls (p=0.0001). Allele and genotype frequencies of -819 T/C were not significantly associated with UC. Furthermore, the frequencies of haplotypes -1082A/-819C and -1082A/-819T, which have been reported to have a lower promoter activity, were significantly higher in UC patients than in controls (p=0.0004). After gender stratification, we found a significant difference in the -1082A allele (p=0.00004) and genotype (p=0.0002) frequencies only between female UC patients and controls; the same result was obtained for the -1082A/-819C and -1082A/-819T haplotypes (p=0.0006).

CONCLUSIONS

A gender effect is observed, with women of AG/AA IL10 genotypes and AC/AT haplotypes having a higher risk of developing UC at a younger age. This finding could be related to the previously documented lower IL10 production associated with the -1082A allele and to the IL10 down-regulating effect of estrogens.

Up-regulation of Bcl-2 through ERK phosphorylation is associated with human macrophage survival in an estrogen microenvironment

Estrogen is a known immunomodulator with pleiotropic effects on macrophage function that partly accounts for the gender bias observed in numerous autoimmune, cardiovascular, and neurodegenerative disorders. The effect of estrogen on the survival of human macrophages is largely unknown, and in this study we demonstrate that 17beta-estradiol (E2) provokes a death response in human THP-1 macrophages by initiating Bax translocation from cytosol to the mitochondria; however, a concomitant up-regulation of Bcl-2 creates a Bax to Bcl-2 ratio favorable for Bcl-2, thus ensuring cell survival. Both Bcl-2 up-regulation and Bax translocation are estrogen receptor-dependent events; however, Bcl-2 augmentation but not Bax translocation is dependent on Ca(2+) increase, activation of protein kinase C, and ERK phosphorylation. This estrogen-induced Bcl-2 increase is crucial for the survival of THP-1 macrophages as well as that of human peripheral blood monocyte-derived macrophages, which is evident from E2-induced cell death under small interfering RNA-mediated Bcl-2 knockdown conditions. Hence, this study demonstrates that E2-induced Bcl-2 up-regulation is a homeostatic survival mechanism necessary for the manifestation of immunomodulatory effect of estrogen on human macrophages.

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.

Sex differences in monocyte expression of IL-6: role of autonomic mechanisms

Sex differences in the prevalence of inflammatory disorders exist, perhaps due to sex differences in cellular mechanisms that contribute to proinflammatory cytokine activity. This study analyzed sex differences of monocyte intracellular expression of IL-6 and its associations with reproductive hormones and autonomic mechanisms in 14 matched pairs of men and women ( n = 28). Monocyte intracellular IL-6 production was repeatedly assessed over two circadian periods. Sympathetic balance was estimated by heart rate variability and the ratio of power in the low-frequency (LF) to high-frequency (HF); vagal tone was indexed by the power of HF component. As compared to men, women showed greater monocyte expression of IL-6 across the circadian period. In addition, women showed lower sympathetic balance (LF/HF ratio), and greater levels of vagal tone (HF power). In women, but not men, sympathovagal balance was negatively associated with monocyte IL-6 expression, whereas vagal tone was positively associated with production of this cytokine. Levels of reproductive hormones were not related to monocyte IL-6 expression. The marked increase in monocyte expression of interleukin-6 in women has implications for understanding sex differences in risk of inflammatory disorders. Additionally, these data suggest that sex differences in sympathovagal balance or vagal tone may be a pathway to explain sex differences in IL-6 expression. Interventions that target autonomic mechanisms might constitute new strategies to constrain IL-6 production with impacts on inflammatory disease risk in women.

Oestrogen receptor negative breast cancers exhibit high cytokine content

Introduction

An emerging hypothesis suggests that cytokines could play an important role in cancer as potential modulators of angiogenesis and leucocyte infiltration.

Methods

A novel multiplexed flow cytometry technology was used to measure the expression of 17 cytokines (IL-1β, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12 [p70], IL-13, IL-17, granulocyte colony-stimulating factor [CSF], granulocyte-macrophage CSF, IFN-γ, monocyte chemoattractant protein [MCP]-1, macrophage inflammatory protein [MIP]-1β, tumour necrosis factor [TNF]-α) at the protein level in 105 breast carcinoma. B lymphocyte, T lymphocyte and macrophage levels were determined by immunohistochemistry.

Results

Fourteen of the 17 cytokines were expressed in breast carcinoma, whereas only nine cytokines could be detected in normal breast. Most cytokines were more abundant in breast carcinoma than in normal breast, with IL-6, IL-8, granulocyte CSF, IFN-γ, MCP-1 and MIP-1β being very abundant. IL-2, IL-6, IL-8, IL-10, IFN-γ, MCP-1, MIP-1β and TNF-α, and to a lesser extent IL-1β and IL-13 exhibited levels of expression that were inversely correlated to oestrogen receptor and progesterone receptor status. Most cytokines were not correlated with age at cancer diagnosis, tumour size, histological type, or lymph node status. However, IL-1β, IL-6, IL-8, IL-10, IL-12, MCP-1 and MIP-1β were more abundant in high-grade tumours than in low-grade tumours. In addition, IL-8 and MIP-1β were expressed to a greater degree in HER2-positive than in HER2-negative patients. The expression of most of the studied cytokines was correlated to levels of activator protein-1, which is known to regulate numerous cytokines. Overexpression of MCP-1 and MIP-1β were linked to B lymphocyte, T lymphocyte and macrophage infiltration, whereas high levels of IL-8 were correlated with high macrophage content in tumour. Moreover, IL-8 positive tumours exhibited increased vascularization.

Conclusion

We found that multiple cytokines were overexpressed in oestrogen receptor negative breast carcinoma, and that the three major cytokines – MCP-1, MIP-1β and IL-8 – were correlated with inflammatory cell component, which could account for the aggressiveness of these tumours.

The Generation of Extracellular DNA in SLE: the Role of Death and Sex

DNA is a large macromolecule that plays a central role in the pathogenesis of systemic lupus erythematosus (SLE), serving as a target antigen of autoantibodies as well as a major component of immune complexes. These complexes can both promote immune disturbances as well as deposit in the kidney to incite inflammation. While the origin of anti-DNA autoantibodies in SLE has received intense investigation, the mechanisms by which DNA exits cells to form immune complexes in the circulation is not well understood. To determine the origin of DNA circulating in the blood in SLE, our laboratory has been using a murine model system to track the in vivo fate of DNA from Jurkat T cells that have been made apoptotic or necrotic in vitro and then administered to mice. Results of these studies indicate that DNA from apoptotic and necrotic cells appears in the blood in a time- and dose-dependent manner. Irrespective of origin, this DNA has properties of nucleosomes as shown by its molecular weight. The process of release requires the presence of macrophages and can be modified by glucocorticoids as well as inflammation. In addition, sex may play a role in the generation of extracellular DNA from dead cells as male and female mice differ in their responses in this model. Together, these studies clarify the origin of extracellular DNA circulating in the blood in SLE and suggest steps in this process that can be interdicted by novel therapy.

Role of Estrogens in Inflammatory Response: Expression of Estrogen Receptors in Peritoneal Fluid Macrophages from Endometriosis

Estrogens are involved in the immune response, and macrophages express estrogen receptors (ER). Moreover, macrophages are the predominant cell type in the peritoneal fluid from endometriosis patients. On this basis, the aim of our study was to evaluate the expression of ER on peritoneal macrophages from endometriosis patients and to compare these results with what is already known about ER and macrophages in RA. After macrophage extraction from peritoneal fluids we performed the immunohistochemical localization of ERalpha and ERbeta and then the image analysis. We found that both ERs were significantly overexpressed in macrophages of women with endometriosis compared with controls. These results suggest that estrogens, through their functional receptors, might modulate the immune response at least on macrophages. Therefore, estrogens seem to play an important role in the immune response, independently from the pathology.

Estrogen down-regulates nicotine-induced adhesion molecule expression via nongenomic signal pathway in endothelial cells

Although gonadal hormone mostly causes genotropic actions through the members of nuclear receptor family, it also can regulate these actions via membrane receptor. To explore the possibility of plasma membrane estrogen receptors (mER) mediating genotropic events, we have investigated estrogen's effect on nicotine-stimulated adhesion molecule expression and evaluated whether this effect depends on calcium, MAPK signal pathway. Fluorescence Spectroscopy analysis of Ca2+ from human umbilical vein endothelial cells (HUVECs) showed through mER, estrogen induced a rapid rise of intracellular free Ca2+ concentration and this rise could not be inhibited by tamoxifen (classic ER inhibitor). In the context of nicotine stimulating, however, estrogen attenuated phosphorylation of mitogen-activated protein kinase (MAPK) family members, extracellular signal regulated kinase 1/2 (ERK1/2), p38 but not c-Jun-N-terminal kinase (JNK) in HUVECs and this effect could not still be prevented by tamoxifen. In the meantime, estrogen also down-regulated surface/soluble vascular cell adhesion molecule (VCAM-1, sVCAM-1) and endothelial selectin (E-selectin, sE-selectin) levels, which was not abolished by tamoxifen either. Moreover, calcium chelator BAPTA, ERK1/2 inhibitor PD98059, p38 inhibitor SB203580 significantly reduced the production of nicotine-activated surface/soluble VCAM-1 and E-selectin and both of the remained levels were no longer regulated by estrogen. Our study here provides the information of decrease effect of mER-mediated estrogen through Ca2+ and ERK1/2, p38 MAPK signaling pathway on nicotine-stimulated expression of surface/soluble VCAM-1 and E-selectin in HUVECs.

Estrogen regulation of nitric oxide and inducible nitric oxide synthase (iNOS) in immune cells: implications for immunity, autoimmune diseases, and apoptosis

Nitric oxide plays a central role in the physiology and pathology of diverse tissues including the immune system. It is clear that the levels of nitric oxide must be carefully regulated to maintain homeostasis. Appropriate levels of nitric oxide derived from iNOS assist in mounting an effective defense against invading microbes. Conversely, inability to generate nitric oxide results in serious, even fatal, susceptibility to infections. Further, dysregulation or overproduction of nitric oxide has been implicated in the pathogenesis of many disorders, including atherosclerosis, neurodegenerative diseases, inflammatory autoimmune diseases, and cancer. Therefore, depending upon the levels of nitric oxide generated, the potential exists for nitric oxide to behave like a "double-edged" biological sword. Taking these issues into consideration, it is thus pivotal to understand the regulation of nitric oxide. Nitric oxide is regulated by many endogenous factors including hormones such as estrogens. While the effects of estrogen on the generation of nitric oxide in non-immune tissues are relatively well documented, the effect of estrogen on iNOS/nitric oxide in immune cells is only now becoming apparent. Our laboratory has recently shown that estrogen treatment of mice markedly upregulates the levels of iNOS mRNA, iNOS protein, and nitric oxide in activated splenocytes. This upregulation of nitric oxide is in part mediated through interferon-gamma (IFN-gamma), a pro-inflammatory cytokine that is enhanced by estrogen. These findings are important considering that estrogens are not only involved in regulation of normal immune responses, but also are implicated in many autoimmune and inflammatory diseases. To date, there are no reviews on the effects of estrogen on immune tissue-derived nitric oxide and therefore this review will address this critical gap in the literature. Given the increasing importance of immune-tissue-derived iNOS in health and disease, studies on estrogen-induced regulation of iNOS may offer a better understanding of diseases and aid in devising new therapeutic interventions.

Sex hormones and SLE: influencing the fate of autoreactive B cells

The prevalence of systemic lupus erythematosus (SLE) is far higher in females than in males and numerous investigations to understand this gender bias have been conducted. While it is plausible that some sex-linked genes may contribute to the genetic predisposition for the disease, other likely culprits are the sex hormones estrogen and prolactin. In this chapter we review studies that have addressed the influence of sex hormones in SLE activity and discuss the recent data established in a BALB/c mouse transgenic for the heavy chain of an anti-DNA antibody. These mice are prone to develop lupus following exposure to exogenous sex hormones. We describe how estrogen and prolactin influence B cell maturation and selection, permitting B cells to mature to immunocompetence. Finally, we discuss the relevance and implications of these data for human disease.

Innate and adaptive immunity in female genital tract: cellular responses and interactions

The mucosal immune system in the female reproductive tract (FRT) has evolved to meet the unique requirements of dealing with sexually transmitted bacterial and viral pathogens, allogeneic spermatozoa, and the immunologically distinct fetus. Analysis of the FRT indicates that the key cells of the innate and adaptive immune systems are present and functionally responsive to antigens. Acting through Toll-like receptors in the Fallopian tubes, uterus, cervix, and in the vagina, epithelial cells, macrophages, natural killer cells, and neutrophils confer protection through the production of chemokines and cytokines, which recruit and activate immune cells, as well as bactericidal and virucidal agents, which confer protection at times when adaptive immunity is downregulated by sex hormones to meet the constraints of procreation. The overall goal of this paper is to define the innate immune system in the FRT and, where possible, to define the regulatory influences that occur during the menstrual cycle that contribute to protection from and susceptibility to potential pathogens. By understanding the nature of this protection and the ways in which innate and adaptive immunity interact, these studies provide the opportunity to contribute to the foundation of information essential for ensuring reproductive health.

Estrogen as an immunomodulator

Estrogen's role in the sex differences observed in autoimmune diseases such as systemic lupus, multiple sclerosis, and rheumatoid arthritis have remained unclear. Complicating the understanding of the immunomodulatory effects of estrogen are (1) the effects of estrogen on multiple components of the immune response; (2) its varied effects on different systems in which it appears pro-autoimmune, as in murine lupus, or anti-inflammatory, as in EAE; and (3) its effects on other hormones which are potentially immunomodulatory. Recent reports have shed light on the role of estrogen in the modulation of lymphocyte survival and expansion and in the elaboration of Th1 versus Th2 cytokines and on the mechanisms by which estrogen can activate via multiple signaling and genomic pathways in immune cells.

Estrogen in cardiovascular disease

PURPOSE OF REVIEW

The controversy surrounding hormone replacement therapy has induced fear in patients and left many researchers with the impression that estrogen produces negative effects on cardiovascular function. The aim of this review is to summarize recent findings illustrating that estrogen also has positive effects even if estrogen replacement therapy is not a cure-all.

RECENT FINDINGS

Studies have unveiled new aspects of estrogen action in the cardiovascular system; however, clinical trials have not demonstrated a protective effect of the most widely used modalities of hormone replacement therapy against cardiovascular disease. New information has emerged showing that estrogen has both beneficial and detrimental effects. Further mechanistic studies and use of well defined forms of estrogens and selective estrogen receptor modulators will continue to provide novel mechanistic information that will likely lead to the development of new avenues for therapeutic interventions.

SUMMARY

Estrogens, like other steroid hormones, are potent actors in the cardiovascular system. Since half the population have high levels of estrogen most of their lives it is plain that estrogen has a variety of beneficial physiologic functions. Clinical studies, however, have demonstrated that a specific formulation of a combination of potent estrogens and metabolites is not a magic bullet, but induces both positive and negative impacts on different organ systems. More research into the mechanistic actions of estrogens in specific pathways in individual cell types is necessary to determine appropriate therapeutic interventions to replace the loss of positive effects of estrogens while minimizing the negative effects in postmenopausal women.

Estrogen replacement, aging, and cell-mediated immunity after injury

We recently demonstrated that aged mice are less likely to survive following traumatic injury and are more immunosuppressed than young mice who sustain comparable injuries. Immunosuppression in severely injured patients and in rodent models of burn injury is associated with a marked elevation in proinflammatory cytokines, including interleukin-6 (IL-6). We reported that after sustaining a moderate-size scald injury, aged mice have higher circulating levels of IL-6 than young, injured mice. As proestrus levels of estrogen have been reported to boost immune responses and attenuate IL-6 production, in the present study, we went on to determine if estrogen replacement in aged female mice restored cellular immunity and proinflammatory cytokine production. After injury, in placebo-treated, aged animals, there was a >75% suppression in the delayed-type hypersensitivity response relative to placebo-treated, sham-injured, aged mice (P<0.05). In contrast, estrogen supplementation before injury yielded a partial recovery in this response, such that the mice were suppressed by only 40% relative to sham-injured, aged mice (P<0.05). There was a fourfold increase in the circulating level of IL-6 in burn-injured, aged mice who received placebo hormone replacement relative to sham-injured mice given placebo (P<0.05). This level of cytokine was lowered by nearly 50% in aged, estrogen-treated mice. Most remarkably, estrogen replacement improved survival from 42% (in the absence of estrogen) to 70% in aged, burn-injured mice. Further investigation will be needed to determine if age- and gender-specific therapies are needed for the treatment of all trauma patients.