High prevalence of increased interleukin-17A serum levels in postmenopausal estrogen deficiency

Non-Infectious Uveitis and Pregnancy, is There an Optimal Treatment? Uveitis Course and Safety of Uveitis Treatment in Pregnancy

In pregnancy, a plethora of factors causes changes in maternal immunity. Uveitis flare-ups are more frequent in the first trimester and in undertreated patients. Management of non-infectious uveitis during pregnancy remains understudied. A bibliographic review to consolidate existing evidence was performed by a multidisciplinary group of Ophthalmologists, Gynaecologists and Rheumatologists. Our group recommends initial management with minimum-required doses of corticosteroids, preferably locally, to treat intraocular inflammation whilst ensuring good neonatal outcomes. If ineffective, clinicians should consider addition of Cyclosporine, Azathioprine or Certolizumab pegol, which are seemingly safe in pregnancy. Other therapies (such as Methotrexate, Mycophenolate Mofetil and alkylating agents) are teratogenic or have a detrimental effect on the foetus. Furthermore, careful multidisciplinary preconception discussions and close follow-up are recommended, monitoring for flare-ups and actively tapering medication doses, with a primary endpoint focused on protecting ocular tissues from inflammation, whilst giving minimal risk of poor pregnancy and foetal outcomes.

Interleukin-17, C-reactive protein, Neutrophil-to-Lymphocyte ratio, Lymphocyte-to-Monocyte ratio, and lipid profiles in healthy menopausal women with or without hot flashes: A cross-sectional study

INTRODUCTION

The reciprocation between systemic inflammatory markers (SIMs), dyslipidemia, and hot flashes (HFs) can play a part in the pathogenesis of endothelial dysfunction through menopause. This study intended to determine the association between some SIMs, lipids, and HFs in healthy menopausal women.

MATERIALS AND METHODS

We designed a cross-sectional study in which 160 healthy menopausal women aged 40-60 were enrolled. Concerning their HFs status, they were stratified into two groups by consecutive sampling: without HFs (n = 40) and with HFs (n = 120). In addition to clinical variables and HFs experience, we measured the fasting serum levels of SIMs and lipid profiles (LPs), including Interleukin-17 (IL-17), high- sensitivity C-Reactive Protein (hs-CRP), Total Cholesterol (TC), Triglycerides (TG), Low-Density Lipoprotein Cholesterol (LDL-C), and High-Density Lipoprotein Cholesterol (HDL-C) in each group. Then, we calculated TC/HDL-C concerning the related variables and determined Neutrophil-to-Lymphocyte Ratio (NLR), and Lymphocyte-to-Monocyte Ratio (LMR), according to Complete Blood Count (CBC) quantitative parameters in each group. Furthermore, we used logistic regression analysis to assess the association between SIMs, LPs, and HFs.

SETTINGS

We performed this study in a governmental teaching hospital, Guilan/Rasht, Iran, from April to September 2021.

RESULTS

The two groups of menopausal women without and with HFs were not significantly different regarding the median of IL-17, hs-CRP, NLR, LMR, TG, HDL-C, and TC/HDL-C, and the mean of TC and LDL-C. Based on multiple logistic regression, TG levels appeared to be associated with the incidence of HFs (B = 0.004, P = 0.040, Odds Ratio:1.004, 95%CI:1.000-1.009). NLR seemed to have an increasing impact on the HFs severity, according to ordinal logistic regression (B = 0.779, P = 0.005, Odds Ratio = 2.180, 95%CI:1.270-3.744). Furthermore, hs-CRP negatively correlated with TG (r = -0.189, P = 0.039) and TC/HDL-C (r = -0.268, P = 0.003) in menopausal women with HFs.

CONCLUSION

This study indicated an association between SIMs, lipids, and HFs. These connections may suggest HFs as links between SIMs/LPs alterations and their outcomes.

Hyperoside alleviates postmenopausal osteoporosis via regulating miR-19a-5p/IL-17A axis

PROBLEM

Postmenopausal osteoporosis (PMO) is a common osteoporosis. Hyperoside (Hyp), a natural flavonoid compound, has anti-osteoporotic effects, but the underlying mechanisms remain poorly understood. Inflammatory cytokine IL-17A is upregulated in PMO and plays vital roles in bone loss, but the upstream regulatory factors and mechanisms are still unknown.

METHOD OF STUDY

Twenty PMO patients and 20 healthy control subjects were included to analyze IL-17A expression changes and screen dys-regulated miRNAs in the peripheral blood of PMO patients. miR-19a-5p mimics and inhibitor were transfected into RAW264.7 osteoclasts, and injected into bilateral ovariectomized (OVX) mice to explore the regulatory effect of miR-19a-5p on IL-17A. OVX mice were randomly grouped and treated with different doses of Hyp to uncover the effective targets for the medicine in PMO disease.

RESULTS

MiR-19a-5p was downregulated in PMO patients and the expression level was negatively correlated with that of IL-17A. miR-19a-5p could directly bind to the 3'UTR of IL-17A and regulate its expression. Both in vitro and in vivo studies demonstrated that miR-19a-5p mimics decreased the expression of IL-17A, RANK and Cathepsin K, while miR-19a-5p inhibitor significantly increased the expression of IL-17A, RANK, and Cathepsin K. Importantly, the Hyp could improve bone structure of OVX mice by enhancing miR-19a-5p-mediated IL-17A downregulation.

CONCLUSION

Overall, these data demonstrated that miR-19a-5p/IL-17A axis might serve as novel therapeutic candidate for PMO. Hyp could relieve bone resorption by targeting the miR-19a-5p/IL-17A axis in OVX mice and exhibited prospective for the treatment of PMO.

Sex differences in cardiovascular response to sepsis

Recently, there has been increased recognition of the importance of sex as a biological factor affecting disease and health. Many preclinical studies have suggested that males may experience a less favorable outcome in response to sepsis than females. The underlying mechanisms for these differences are still largely unknown but are thought to be related to the beneficial effects of estrogen. Furthermore, the immunosuppressive role of testosterone is also thought to contribute to the sex-dependent differences that are present in clinical sepsis. There are still significant knowledge gaps in this field. This mini-review will provide a brief overview of sex-dependent variables in relation to sepsis and the cardiovascular system. Preclinical animal models for sepsis research will also be discussed. The intent of this mini-review is to inspire interest for future considerations of sex-related variables in sepsis that should be addressed to increase our understanding of the underlying mechanisms in sepsis-induced cardiovascular dysfunction for the identification of therapeutic targets and improved sepsis management and treatment.

Sex Hormones as Key Modulators of the Immune Response in Multiple Sclerosis: A Review

BACKGROUND

A variety of autoimmune diseases, including MS, amplify sex-based physiological differences in immunological responsiveness. Female MS patients experience pathophysiological changes during reproductive phases (pregnancy and menopause). Sex hormones can act on immune cells, potentially enabling them to modify MS risk, activity, and progression, and to play a role in treatment.

METHODS

Scientific papers (published between 1998 and 2021) were selected through PubMed, Google Scholar, and Web of Science literature repositories. The search was limited to publications analyzing the hormonal profile of male and female MS patients during different life phases, in particular focusing on sex hormone treatment.

RESULTS

Both men and women with MS have lower testosterone levels compared to healthy controls. The levels of estrogens and progesterone increase during pregnancy and then rapidly decrease after delivery, possibly mediating an immune-stabilizing process. The literature examined herein evidences the neuroprotective effect of testosterone and estrogens in MS, supporting further examinations of their potential therapeutic uses.

CONCLUSIONS

A correlation has been identified between sex hormones and MS clinical activity. The combination of disease-modifying therapies with estrogen or estrogen plus a progestin receptor modulator promoting myelin repair might represent an important strategy for MS treatment in the future.

The Role of Prunes in Modulating Inflammatory Pathways to Improve Bone Health in Postmenopausal Women

The prevalence of osteoporosis among women aged 50 y and older is expected to reach 13.6 million by 2030. Alternative nonpharmaceutical agents for osteoporosis, including nutritional interventions, are becoming increasingly popular. Prunes (dried plums; Prunus domestica L.) have been studied as a potential whole-food dietary intervention to mitigate bone loss in preclinical models of osteoporosis and in osteopenic postmenopausal women. Sixteen preclinical studies using in vivo rodent models of osteopenia or osteoporosis have established that dietary supplementation with prunes confers osteoprotective effects both by preventing and reversing bone loss. Increasing evidence from 10 studies suggests that, in addition to antiresorptive effects, prunes exert anti-inflammatory and antioxidant effects. Ten preclinical studies have found that prunes and/or their polyphenol extracts decrease malondialdehyde and NO secretion, increase antioxidant enzyme expression, or suppress NF-κB activation and proinflammatory cytokine production. Two clinical trials have investigated the impact of dried plum consumption (50-100 g/d for 6-12 mo) on bone health in postmenopausal women and demonstrated promising effects on bone mineral density and bone biomarkers. However, less is known about the impact of prune consumption on oxidative stress and inflammatory mediators in humans and their possible role in modulating bone outcomes. In this review, the current state of knowledge on the relation between inflammation and bone health is outlined. Findings from preclinical and clinical studies that have assessed the effect of prunes on oxidative stress, inflammatory mediators, and bone outcomes are summarized, and evidence supporting a potential role of prunes in modulating inflammatory and immune pathways is highlighted. Key future directions to bridge the knowledge gap in the field are proposed.

Sex-biased adaptive immune regulation in cancer development and therapy

The cancer research field is finally starting to unravel the mystery behind why males have a higher incidence and mortality rate than females for nearly all cancer types of the non-reproductive systems. Here, we explain how sex - specifically sex chromosomes and sex hormones - drives differential adaptive immunity across immune-related disease states including cancer, and why males are consequently more predisposed to tumor development. We highlight emerging data on the roles of cell-intrinsic androgen receptors in driving CD8+ T cell dysfunction or exhaustion in the tumor microenvironment and summarize ongoing clinical efforts to determine the impact of androgen blockade on cancer immunotherapy. Finally, we outline a framework for future research in cancer biology and immuno-oncology, underscoring the importance of a holistic research approach to understanding the mechanisms of sex dimorphisms in cancer, so sex will be considered as an imperative factor for guiding treatment decisions in the future.

Estrogen, the Peripheral Immune System and Major Depression – A Reproductive Lifespan Perspective

Major depression is a significant medical issue impacting millions of individuals worldwide. Identifying factors contributing to its manifestation has been a subject of intense investigation for decades and several targets have emerged including sex hormones and the immune system. Indeed, an extensive body of literature has demonstrated that sex hormones play a critical role in modulating brain function and impacting mental health, especially among female organisms. Emerging findings also indicate an inflammatory etiology of major depression, revealing new opportunities to supplement, or even supersede, currently available pharmacological interventions in some patient populations. Given the established sex differences in immunity and the profound impact of fluctuations of sex hormone levels on the immune system within the female, interrogating how the endocrine, nervous, and immune systems converge to impact women’s mental health is warranted. Here, we review the impacts of endogenous estrogens as well as exogenously administered estrogen-containing therapies on affect and immunity and discuss these observations in the context of distinct reproductive milestones across the female lifespan. A theoretical framework and important considerations for additional study in regards to mental health and major depression are provided.

Deletion of IL-17ra in osteoclast precursors increases bone mass by decreasing osteoclast precursor abundance

Metabolic bone diseases, such as osteoporosis, typically reflect an increase in the number and activity of bone-resorbing osteoclasts that result in a loss of bone mass. Inflammatory mediators have been identified as drivers of both osteoclast formation and activity. The IL-17 family of inflammatory cytokines has gained attention as important contributors to both bone formation and resorption. The majority of IL-17 cytokines signal through receptor complexes containing IL-17a receptor (IL-17ra); however, the role of IL-17ra signaling in osteoclasts remains elusive. In this study, we conditionally deleted Il17ra in osteoclast precursors using LysM-Cre and evaluated the phenotypes of skeletally mature male and female conditional knockout and control mice. The conditional knockout mice displayed an increase in trabecular bone microarchitecture in both the appendicular and axial skeleton. Assessment of osteoclast formation in vitro revealed that deletion of Il17ra decreased osteoclast number, which was confirmed in vivo using histomorphometry. This phenotype was likely driven by a lower abundance of osteoclast precursors in IL-17ra conditional knockout mice. This study suggests that IL-17ra signaling in preosteoclasts can contribute to osteoclast formation and subsequent bone loss.

Serum interleukin-17 and estradiol levels in postmenopausal women in relation to osteoporosis

Background

In post-menopausal women, estrogen deficiency leads to instability between bone formation and resorption which is regulated by osteoclastogenic cytokines leading to resorption. Interleukin-17 (IL-17) a proinflammatory cytokine has been found as an important regulator of osteoclast-genesis induced by estrogen deficiency in favor of bone loss in animal studies.

The study aimed to evaluate levels of IL-17 and estrogen (E2) in relation to bone mineral density (BMD) and risk of fracture in postmenopausal women with and without osteoporosis.

Results

IL-17 levels were significantly higher and E2 levels were significantly lower in the osteoporotic group compared to the non-osteoporotic group (P value ≤ 0.01). There was a highly significant difference in DEXA score and FRAX index between two groups: with higher values of FRAX and lower values of DEXA score among osteoporotic group (P value ≤ 0.01). IL-17 was inversely correlated to estrogen level and highly significant negative correlation with DEXA as well as a highly significant positive one with FRAX index. IL-17 serum level was able to diagnose osteoporosis at a cutoff level of > 80 pg/mL with 100% sensitivity, 100% specificity, 100% positive predictive value (PPV), and 100% negative predictive value (NPV).

Conclusions

Serum IL-17 was significantly elevated in osteoporotic postmenopausal women when compared to healthy postmenopausal ones and was inversely correlated with estrogen level and DEXA.

Increased frequency of Th17 cells and IL-17 levels are associated with low bone mineral density in postmenopausal women

Osteoporosis is one of the chronic and often neglected bone diseases in aging postmenopausal women that affect the quality of life. Studies on ovariectomized mice models indicated the reciprocal role of Th17 cells and Treg cells in the aetiology of osteoporosis. While Th17 cells promote osteoclastogenesis, Treg cells exhibit anti-osteoclastogenic activity. This exploratory study aimed to determine the difference in the frequency of these T-cell subtypes in pre-and postmenopausal women and to examine their association with BMD. In our study, the frequency of Treg cells, analyzed by flow cytometry, did not differ between pre-and postmenopausal women. However, plasma levels of IL-10 along with IL-10+CD4+T cells were higher in post- compared to premenopausal women. The frequency of Th17 cells was higher in postmenopausal women irrespective of their BMD, however, only postmenopausal women with low BMD had elevated IL-17 levels and their T-scores were associated with Th17 frequency. Collectively, the results suggest that estrogen insufficiency in postmenopausal women may lead to increased Th17 cell frequency and elevated IL-17 levels which are associated with low BMD. This study highlights, Th17 cells and IL-17 as key players in the pathogenesis of osteoporosis and they can be the potential targets for immunotherapy in the treatment of osteoporosis.

Revisiting steroidogenesis and its role in immune regulation with the advanced tools and technologies

Historically tools and technologies facilitated scientific discoveries. Steroid hormone research is not an exception. Unfortunately, the dramatic advancement of the field faded this research area and flagged it as a solved topic. However, it should have been the opposite. The area should glitter with its strong foundation and attract next-generation scientists. Over the past century, a myriad of new facts on biochemistry, molecular biology, cell biology, physiology and pathology of the steroid hormones was discovered. Several innovations were made and translated into life-saving treatment strategies such as synthetic steroids, and inhibitors of steroidogenesis and steroid signaling. Steroid molecules exhibit their diverse effects on cell metabolism, salt and water balance, development and function of the reproductive system, pregnancy, and immune-cell function. Despite vigorous research, the molecular basis of the immunomodulatory effect of steroids is still mysterious. The recent excitement on local extra-glandular steroidogenesis in regulating inflammation and immunity is revitalizing the topic with a new perspective. Therefore, here we review the role of steroidogenesis in regulating inflammation and immunity, discuss the unresolved questions, and how this area can bring another golden age of steroid hormone research with the development of new tools and technologies and advancement of the scientific methods.

Sex Hormones and Lung Inflammation

Inflammation is a characteristic marker in numerous lung disorders. Several immune cells, such as macrophages, dendritic cells, eosinophils, as well as T and B lymphocytes, synthetize and release cytokines involved in the inflammatory process. Gender differences in the incidence and severity of inflammatory lung ailments including asthma, chronic obstructive pulmonary disease (COPD), pulmonary fibrosis (PF), lung cancer (LC), and infectious related illnesses have been reported. Moreover, the effects of sex hormones on both androgens and estrogens, such as testosterone (TES) and 17β-estradiol (E2), driving characteristic inflammatory patterns in those lung inflammatory diseases have been investigated. In general, androgens seem to display anti-inflammatory actions, whereas estrogens produce pro-inflammatory effects. For instance, androgens regulate negatively inflammation in asthma by targeting type 2 innate lymphoid cells (ILC2s) and T-helper (Th)-2 cells to attenuate interleukin (IL)-17A-mediated responses and leukotriene (LT) biosynthesis pathway. Estrogens may promote neutrophilic inflammation in subjects with asthma and COPD. Moreover, the activation of estrogen receptors might induce tumorigenesis. In this chapter, we summarize the most recent advances in the functional roles and associated signaling pathways of inflammatory cellular responses in asthma, COPD, PF, LC, and newly occurring COVID-19 disease. We also meticulously deliberate the influence of sex steroids on the development and progress of these common and severe lung diseases.

Epigenetics, pregnancy and autoimmune rheumatic diseases

Autoimmune rheumatic diseases (ARDs) are chronic conditions with a striking female predominance, frequently affecting women of childbearing age. Sex hormones and gender dimorphism of immune response are major determinants in the multifactorial pathogenesis of ARDs, with significant implications throughout reproductive life. Particularly, pregnancy represents a challenging condition in the context of autoimmunity, baring profound hormonal and immunologic changes, which are responsible for the bi-directional interaction between ARDs outcome and pregnancy course. In the latest years epigenetics has proven to be an important player in ARDs pathogenesis, finely modulating major immune functions and variably tuning the significant gender effects in autoimmunity. Additionally, epigenetics is a recognised influencer of the physiological dynamic modifications occurring during pregnancy. Still, there is currently little evidence on the pregnancy-related epigenetic modulation of immune response in ARDs patients. This review aims to overview the current knowledge of the role of epigenetics in the context of autoimmunity, as well as during physiologic and pathologic pregnancy, discussing under-regarded aspects in the interplay between ARDs and pregnancy pathology. The outline of a new ongoing European project will be presented.

Phytochemicals affect T helper 17 and T regulatory cells and gut integrity: implications on the gut-bone axis

The pathology of osteoporosis is multifactorial, but a growing body of evidence supports an important role of the gut-bone axis, especially in bone loss associated with menopause, rheumatoid arthritis, and periodontal disease. Aberrant T cell responses favoring an increase in the ratio of T helper 17 cells to T regulatory cells play a critical role in the underlying etiology of this bone loss. Many of the dietary phytochemicals known to have osteoprotective activity such as flavonoids, organosulfur compounds, phenolic acids, as well as the oligosaccharides also improve gut barrier function and affect T cell differentiation and activation within gut-associated lymphoid tissues and at distal sites. Here, we examine the potential of these phytochemicals to act as prebiotics and immunomodulating agents, in part targeting the gut to mediate their effects on bone.

Estrogen, estrogen-like molecules and autoimmune diseases

In western countries, the slope of autoimmune disease (AD) incidence is increasing and affects 5-8% of the population. Mainly prevalent in women, these pathologies are due to thymic tolerance processes breakdown. The female sex hormone, estrogen, is involved in this AD female susceptibility. However, predisposition factors have to act in concert with unknown triggering environmental factors (virus, microbiota, pollution) to initiate AD. Individuals are exposed to various environmental compounds that display endocrine disruption abilities. The cellular effects of some of these molecules may be mediated through the aryl hydrocarbon receptor (AhR). Here, we review the effects of these molecules on the homeostasis of the thymic cells, the immune tolerance intrinsic factors (transcription factors, epigenetic marks) and on the immune tolerance extrinsic factors (microbiota, virus sensibility). This review highlights the contribution of estrogen and endocrine disruptors on the dysregulation of mechanisms sustaining AD development.

Interactions among thyroid hormone (FT4), chemokine (MCP-1) and neurotrophin (NGF-β) levels studied in Hungarian postmenopausal and obese women

Thyroid dysfunction is more frequent in postmenopause and metabolic syndrome characterized by increased proinflammatory cytokines (IL-1, IL-6, TNFα), insulin resistance and overweight. Serum levels of monocyte chemoattractant protein-1 (MCP-1) chemokine and nerve growth factor-β (NGF-β) and their effects were studied on thyroid hormone levels in 133 Hungarian women (postmenopausal 66, obese 32, control 35). MCP-1 and NGF-β levels were measured with enzyme-linked, and thyroid hormones with chemiluminescence immunoassays. Subclinical hypothyroidism in postmenopause (7/66 vs 1/32 cases) and the presence of low FT₄ levels in obese women were more frequent (6/32 vs 2/66 cases, p < 0.0447). Obese women showed reduced serum FT₄ and higher MCP-1 or NGF-β levels compared to those in postmenopausal women [geometric mean (95%CI): 13.6 (10.9-21.69) vs 15.37 (9.06-20.42) pmol/l, p < 0.003 for FT₄, and 19.36 (14.27-26.26) vs 17.29 (12.65-23.63) ng/ml, p < 0.0013 for MCP-1 or 18.64 (6.8-51.11) vs 14.01 (8.59-22.83) ng/ml, p < 0.0003 for NGF-β]. Serum FT₄ levels inversely associated with MCP-1 (p < 0.0023, r = -0.1971) or estradiol levels (p < 0.0286, r = -0.1913), and positively associated with age (p < 0.0175, r = 0.2058). As opposed to estradiol and NGF-β levels, BMI had no effects on serum FT₄ levels in postmenopausal and obese women forming 3 subgroups displaying only MCP-1, both MCP-1 and NGF-β positivities or no positivities at all. In summary, not only proinflammatory cytokines, but also MCP-1 chemokine and NGF-β levels can play a role in reduced serum FT₄ levels in postmenopausal and obese women. Particularly, the decreased FT₄ levels were connected to both increased MCP-1 and NGF-β levels in obese women.

Plasma Cytokine Levels in Overweight Versus Obese Disease-Free Perimenopausal Women

OBJECTIVE

To evaluate the plasma cytokine levels during T cell-mediated inflammatory responses and compare the metabolic markers between overweight and obese perimenopausal women without systemic diseases.

METHODS

Sixty perimenopausal women were divided into two groups (overweight and obese). Participants in both groups had their waist-to-height ratio (WHtR) measured and blood samples collected for the evaluation of estradiol, fasting glucose, leptin, high-sensitivity C-reactive protein (hs-CRP), interleukin (IL)-6, IL-10, IL-17A levels, and lipid profile.

RESULTS

In univariate analysis, women with obesity showed increased WHtR, fasting glucose, leptin, and IL-6 (p < 0.05) levels; however, significant differences were not observed in IL-10 or IL-17A (p > 0.05) levels. In the receiver operating characteristic curve, the highest areas under the curve were shown for leptin (0.856) and IL-6 (0.706). IL-6 levels correlated with both hs-CRP (r = 0.302, p = 0.020) and leptin (r = 0.294, p = 0.022). However, in multivariate analysis, IL-6 was not associated with a greater likelihood of obesity (OR = 1.61; 95% CI: 0.82-3.15; p = 0.16), when potential confounders were considered.

CONCLUSION

IL-6 levels varied between overweight and obese perimenopausal women, and this association was weaker when adjusted for other clinical variables.

Interleukin-17: Potential Target for Chronic Wounds

Chronic wounds exhibit persistent inflammation with markedly delayed healing. The significant burden of chronic wounds, which are often resistant to standard therapy, prompts further research on novel therapies. Since the interleukin-17 family has been implicated as a group of proinflammatory cytokines in immune-mediated diseases in the gut and connective tissue, as well as inflammatory skin conditions, we consider here if it may contribute to the pathogenesis of chronic wounds. In this review, we discuss the interleukin-17 family's signaling pathways and role in tissue repair. A PubMed review of the English literature on interleukin-17, wound healing, chronic wounds, and inflammatory skin conditions was conducted. Interleukin-17 family signaling is reviewed in the context of tissue repair, and preclinical and clinical studies examining its role in the skin and other organ systems are critically reviewed. The published work supports a pathologic role for interleukin-17 family members in chronic wounds, though this needs to be more conclusively proven. Clinical studies using monoclonal interleukin-17 antibodies to improve healing of chronic skin wounds have not yet been performed, and only a few studies have examined interleukin-17 family expression in chronic skin wounds. Furthermore, different interleukin-17 family members could be playing selective roles in the repair process. These studies suggest a therapeutic role for targeting interleukin-17A to promote wound healing; therefore, interleukin-17A may be a target worthy of pursuing in the near future.

The Adaptive Immune System in Multiple Sclerosis: An Estrogen-Mediated Point of View

Multiple sclerosis (MS) is a chronic central nervous system inflammatory disease that leads to demyelination and neurodegeneration. The third trimester of pregnancy, which is characterized by high levels of estrogens, has been shown to be associated with reduced relapse rates compared with the rates before pregnancy. These effects could be related to the anti-inflammatory properties of estrogens, which orchestrate the reshuffling of the immune system toward immunotolerance to allow for fetal growth. The action of these hormones is mediated by the transcriptional regulation activity of estrogen receptors (ERs). Estrogen levels and ER expression define a specific balance of immune cell types. In this review, we explore the role of estradiol (E2) and ERs in the adaptive immune system, with a focus on estrogen-mediated cellular, molecular, and epigenetic mechanisms related to immune tolerance and neuroprotection in MS. The epigenome dynamics of immune systems are described as key molecular mechanisms that act on the regulation of immune cell identity. This is a completely unexplored field, suggesting a future path for more extensive research on estrogen-induced coregulatory complexes and molecular circuitry as targets for therapeutics in MS.

Microbial osteoporosis: The interplay between the gut microbiota and bones via host metabolism and immunity

The complex relationship between intestinal microbiota and host is a novel field in recent years. A large number of studies are being conducted on the relationship between intestinal microbiota and bone metabolism. Bone metabolism consisted of bone absorption and formation exists in the whole process of human growth and development. The nutrient components, inflammatory factors, and hormone environment play important roles in bone metabolism. Recently, intestinal microbiota has been found to influence bone metabolism via influencing the host metabolism, immune function, and hormone secretion. Here, we searched relevant literature on Pubmed and reviewed the effect of intestinal microbiota on bone metabolism through the three aspects, which may provide new ideas and targets for the clinical treatment of osteoporosis.

Autoimmune Disease in Women: Endocrine Transition and Risk Across the Lifespan

Women have a higher incidence and prevalence of autoimmune diseases than men, and 85% or more patients of multiple autoimmune diseases are female. Women undergo sweeping endocrinological changes at least twice during their lifetime, puberty and menopause, with many women undergoing an additional transition: pregnancy, which may or may not be accompanied by breastfeeding. These endocrinological transitions exert significant effects on the immune system due to interactions between the hormonal milieu, innate, and adaptive immune systems as well as pro- and anti-inflammatory cytokines, and thereby modulate the susceptibility of women to autoimmune diseases. Conversely, pre-existing autoimmune diseases themselves impact endocrine transitions. Concentration-dependent effects of estrogen on the immune system; the role of progesterone, androgens, leptin, oxytocin, and prolactin; and the interplay between Th1 and Th2 immune responses together maintain a delicate balance between host defense, immunological tolerance and autoimmunity. In this review, multiple autoimmune diseases have been analyzed in the context of each of the three endocrinological transitions in women. We provide evidence from human epidemiological data and animal studies that endocrine transitions exert profound impact on the development of autoimmune diseases in women through complex mechanisms. Greater understanding of endocrine transitions and their role in autoimmune diseases could aid in prediction, prevention, and cures of these debilitating diseases in women.

Increased IL-17 and/or IFN-γ producing T-cell subsets in gut mucosa of long-term-treated HIV-1-infected women

OBJECTIVE

The influence of sex on gut mucosal T-cell response in HIV-1 infection remains largely unknown. We explored whether the frequencies of interferon-γ and/or IL-17 producing naive, T central memory and T effector memory (TEM) CD4+ (Th1, Th17) and CD8+ T (Tc1, Tc17) cells measured in gut and peripheral districts differed between female and male HIV-1-infected patients.

METHODS

Thirty long-term-treated HIV-1-infected individuals were enrolled. The frequencies of Th1, Th17, Tc1, Tc17-cell subsets (single and double) were evaluated by multiparametric flow cytometry in lamina propria lymphocytes and peripheral blood mononuclear cells (PBMC).

RESULTS

A sex-based pattern was recorded in the differences of Th1, Th17, Tc1, Tc17-cell subset (single and double) frequencies between gut and peripheral blood. Female patients had stronger alterations in the gut mucosal T-cell repertoire, especially increased Th1, Th17, and Th1/Th17-cell subset frequencies, compared with the blood district than their male counterparts. Higher naive Tc1, Tc17, Tc1/Tc17, TEM Tc17, and TEM Tc1/Tc17 levels were also recorded in the gut mucosa than in the PBMC of HIV-1-infected women. Males and females also differed in their gut T-cell response, with women being characterized by higher Th1, Th17, Tc1, Tc17, and Th1/Th17 cells subset levels than men. By contrast, only TEM Th1/Th17 and TEM Tc17 in PBMC differed between males and females.

CONCLUSION

Sex-based differences observed in the gut T-cell response of HIV-1-infected patients might contribute to the disease dimorphism.

Sex Hormones in Acquired Immunity and Autoimmune Disease

Women have stronger immune responses to infections and vaccination than men. Paradoxically, the stronger immune response comes at a steep price, which is the high incidence of autoimmune diseases in women. The reasons why women have stronger immunity and higher incidence of autoimmunity are not clear. Besides gender, sex hormones contribute to the development and activity of the immune system, accounting for differences in gender-related immune responses. Both innate and adaptive immune systems bear receptors for sex hormones and respond to hormonal cues. This review focuses on the role of sex hormones particularly estrogen, in the adaptive immune response, in health, and autoimmune disease with an emphasis on systemic lupus erythematosus.

Glucocorticoids, Sex Hormones, and Immunity

Glucocorticoid hormones regulate essential body functions in mammals, control cell metabolism, growth, differentiation, and apoptosis. Importantly, they are potent suppressors of inflammation, and multiple immune-modulatory mechanisms involving leukocyte apoptosis, differentiation, and cytokine production have been described. Due to their potent anti-inflammatory and immune-suppressive activity, synthetic glucocorticoids (GCs) are the most prescribed drugs used for treatment of autoimmune and inflammatory diseases. It is long been noted that males and females exhibit differences in the prevalence in several autoimmune diseases (AD). This can be due to the role of sexual hormones in regulation of the immune responses, acting through their endogenous nuclear receptors to mediate gene expression and generate unique gender-specific cellular environments. Given the fact that GCs are the primary physiological anti-inflammatory hormones, and that sex hormones may also exert immune-modulatory functions, the link between GCs and sex hormones may exist. Understanding the nature of this possible crosstalk is important to unravel the reason of sexual disparity in AD and to carefully prescribe these drugs for the treatment of inflammatory diseases. In this review, we discuss similarities and differences between the effects of sex hormones and GCs on the immune system, to highlight possible axes of functional interaction.

From Osteoimmunology to Osteomicrobiology: How the Microbiota and the Immune System Regulate Bone

Osteomicrobiology refers to the role of microbiota in bone health and the mechanisms by which the microbiota regulates post-natal skeletal development, bone aging, and pathologic bone loss. Here, we review recent reports linking gut microbiota to changes in bone phenotype. A pro-inflammatory cytokine milieu drives bone resorption in conditions such as sex steroid hormone deficiency. The response of the immune system to activation by the microbiome results in increased circulating osteoclastogenic cytokines in a T cell-dependent mechanism. Additionally, gut microbiota affect bone homeostasis through nutrient absorption, mediation of the IGF-1 pathway, and short chain fatty acid and metabolic products. Manipulation of microbiota through prebiotics or probiotics reduces inflammatory cytokine production, leading to changes in bone density. One mechanism of probiotic action is through upregulating tight junction proteins, increasing the strength of the gut epithelial layer, and leading to less antigen presentation and less activation of intestinal immune cells. Thus, prebiotics or probiotics may represent a future therapeutic avenue for ameliorating the risk of postmenopausal bone loss in humans.

Bone Remodeling and the Microbiome

Exposed surfaces of mammals are colonized with 100 trillion indigenous bacteria, fungi, and viruses, creating a diverse ecosystem known as the microbiome. The gastrointestinal tract harbors the greatest numbers of these microorganisms, which regulate human nutrition, metabolism, and immune system function. Moreover, the intestinal microbiota contains pro- and anti-inflammatory products that modulate immune responses and may play a role in maintaining gut barrier function. Therefore, the community composition of the microbiota has profound effects on the immune status of the host and impacts the development and/or progression of inflammatory diseases. Accordingly, numerous studies have shown differences in the microbiota of patients with and without a given inflammatory condition. There is now strong evidence that the gut microbiome regulates bone homeostasis in health and disease, and that prebiotic and probiotics protect against bone loss. Herein, the evidence supporting the role of the microbiota and the effects of prebiotic and probiotics will be reviewed.

Estrogen Stimulation Differentially Impacts Human Male and Female Antigen-Specific T Cell Anti-Tumor Function and Polyfunctionality

Sex-specific differences exist in innate and adaptive immune responses and are mediated by hormone signaling. Estrogen is able to differentially modulate the development and differentiation of immune cells, including T cells. However, the effect of estrogen on T cell function, especially at concentrations other than physiological, remains controversial and incompletely understood. Immunotherapy is one of the most promising cancer treatments to date with a high probability of future enhancements. The adoptive transfer of genetically modified T cells can mediate tumor regression but there are still many hurdles to enhancing the proficiency of this treatment. This study demonstrates for the first time that one major aspect to consider for designing potent immunotherapies for cancer is the impact of the patient's sex. Herein, using two different Ag-specific T cell groups, we investigated the effect of sex and estrogen in antitumor effector responses, T helper cytokine secretion, and, importantly, on T cell whole polyfunctionality important for memory T cell development and survival. Major differences were observed in T cell function and polyfunctionality between sexes and on E2 treatment. The findings of this study may be critical to understand the results of immunotherapy on different patients and for the enhancement of immunotherapy for cancer.

Intestinal microbiota: a potential target for the treatment of postmenopausal osteoporosis

Postmenopausal osteoporosis (PMO) is a prevalent metabolic bone disease characterized by bone loss and structural destruction, which increases the risk of fracture in postmenopausal women. Owing to the high morbidity and serious complications of PMO, many efforts have been devoted to its prophylaxis and treatment. The intestinal microbiota is the complex community of microorganisms colonizing the gastrointestinal tract. Probiotics, which are dietary or medical supplements consisting of beneficial intestinal bacteria, work in concert with endogenous intestinal microorganisms to maintain host health. Recent studies have revealed that bone loss in PMO is closely related to host immunity, which is influenced by the intestinal microbiota. The curative effects of probiotics on metabolic bone diseases have also been demonstrated. The effects of the intestinal microbiota on bone metabolism suggest a promising target for PMO management. This review seeks to summarize the critical effects of the intestinal microbiota and probiotics on PMO, with a focus on the molecular mechanisms underlying the pathogenic relationship between bacteria and host, and to define the possible treatment options.

Postmenopausal osteoporosis in rheumatoid arthritis: The estrogen deficiency-immune mechanisms link

Rheumatoid arthritis (RA) is characterized, among other factors, by systemic bone loss, reaching ~50% prevalence of osteoporosis in postmenopausal women. This is roughly a doubled prevalence in comparison with age-matched non-RA women. Postmenopausal RA women are more likely to be sero-positive for the anti-citrullinated peptide antibody (ACPA). Our extensive review of recent scientific literature enabled us to propose several mechanisms as responsible for the accelerated bone loss in ACPA(+) RA postmenopausal women. Menopause-associated estrogen deficiency plays a major role in these pathological mechanisms, as follows.

Rheumatoid arthritis onset in postmenopausal women: Does the ACPA seropositive subset result from genetic effects, estrogen deficiency, skewed profile of CD4(+) T-cells, and their interactions?

Rheumatoid arthritis (RA) incidence displays a differentiated age-dependent female-to-male ratio in which women outnumber men. Evidence that the peak incidence of RA in women coincides with menopause age, suggests a potential estrogenic role to disease etiology. Estrogens exert physiologically both stimulatory and inhibitory effects on the immune system. Epidemiologic and animal model studies with estrogen deprivation or supplementation suggested estrogens as to play, mainly, a protective role in RA immunopathology. In this review, we propose that some yet unidentified disturbances associated with estrogen circulating levels, differentiated by the menopausal status, play a major role in women's RA susceptibility. We focus on the interaction between estrogen deprivation and genetic risk alleles for anti-citrullinated protein antibodies (ACPA) seropositive RA, as a major driving force for increased immune reactivity and RA susceptibility, in postmenopausal women. This opens up new fields for research concerning the association among different irregular estrogenic conditions, the cytokine milieu, and age/menopausal status bias in RA.

Sex steroid deficiency-associated bone loss is microbiota dependent and prevented by probiotics

A eubiotic microbiota influences many physiological processes in the metazoan host, including development and intestinal homeostasis. Here, we have shown that the intestinal microbiota modulates inflammatory responses caused by sex steroid deficiency, leading to trabecular bone loss. In murine models, sex steroid deficiency increased gut permeability, expanded Th17 cells, and upregulated the osteoclastogenic cytokines TNFα (TNF), RANKL, and IL-17 in the small intestine and the BM. In germ-free (GF) mice, sex steroid deficiency failed to increase osteoclastogenic cytokine production, stimulate bone resorption, and cause trabecular bone loss, demonstrating that the gut microbiota is central in sex steroid deficiency-induced trabecular bone loss. Furthermore, we demonstrated that twice-weekly treatment of sex steroid-deficient mice with the probiotics Lactobacillus rhamnosus GG (LGG) or the commercially available probiotic supplement VSL#3 reduces gut permeability, dampens intestinal and BM inflammation, and completely protects against bone loss. In contrast, supplementation with a nonprobiotic strain of E. coli or a mutant LGG was not protective. Together, these data highlight the role that the gut luminal microbiota and increased gut permeability play in triggering inflammatory pathways that are critical for inducing bone loss in sex steroid-deficient mice. Our data further suggest that probiotics that decrease gut permeability have potential as a therapeutic strategy for postmenopausal osteoporosis.

The Immune System Is a Natural Target for Estrogen Action: Opposing Effects of Estrogen in Two Prototypical Autoimmune Diseases

Analogous to other physiological systems, the immune system also demonstrates remarkable sex differences. Although the reasons for sex differences in immune responses are not precisely understood, it potentially involves differences in sex hormones (estrogens, androgens, and differential sex hormone receptor-mediated events), X-chromosomes, microbiome, epigenetics among others. Overall, females tend to have more responsive and robust immune system compared to their male counterparts. It is therefore not surprising that females respond more aggressively to self-antigens and are more susceptible to autoimmune diseases. Female hormone (estrogen or 17β-estradiol) can potentially act on all cellular subsets of the immune system through estrogen receptor-dependent and -independent mechanisms. This minireview highlights differential expression of estrogen receptors on immune cells, major estrogen-mediated signaling pathways, and their effect on immune cells. Since estrogen has varied effects in female-predominant autoimmune diseases such as multiple sclerosis and systemic lupus erythematosus, we will mechanistically postulate the potential differential role of estrogen in these chronic debilitating diseases.

Interleukin-17A Levels Vary in Relapsing-Remitting Multiple Sclerosis Patients in Association with Their Age, Treatment and the Time of Evolution of the Disease

OBJECTIVE

The present study was specifically designed to discern the possible existence of subgroups of patients with the relapsing-remitting form of multiple sclerosis (RRMS) depending on their gender, age, disease stage (relapsing or remitting), time of disease evolution and response to different treatments.

METHODS

We analyzed samples from patients with RRMS (50 females and 32 males) and healthy individuals (25 matched for age and gender) and determined serum concentrations of IFN-γ, IL-10 and IL-17A. We stratified patients by gender, age, treatment and disease evolution time, and subsequently correlated these independent variables with the concentrations of the previously mentioned cytokines.

RESULTS

We provided initial evidence that treatment exerted possible differential effects depending on the time of disease duration. Results evidence the existence of different subgroups of patients with MS, who can be classified as follows: (a) male or female under or over 40 years of age; (b) disease duration according to treatment (under or over 8 years of disease); (c) classification according to fluctuating levels of IFN-γ, IL-10 and IL-17A in the following three stages of disease evolution: <5 years, between 5 and 10 years, and >10 years.

CONCLUSION

These subgroups must be taken into account for the clinical follow-up of patients with MS in order to provide them with a better and more personalized treatment, and also for a deep and detailed analysis of progressive disease, in an attempt to comprehend fluctuations and clinical variability by means of a better understanding of intrinsically physiological variables of the disease.

T cells, osteoblasts, and osteocytes: interacting lineages key for the bone anabolic and catabolic activities of parathyroid hormone

Osteoimmunology is a field of research dedicated to the study of the interactions between the immune system and bone. Among the cells of the immune system that regulate bone turnover and the responsiveness of bone cells to calciothropic hormones are bone marrow T lymphocytes. T cells secrete osteoclastogenic cytokines such as RANKL and TNF-α, as well as factors that stimulate bone formation, one of which is Wnt10b. In addition, T cells regulate the differentiation and life span of stromal cells (SCs) and their responsiveness to parathyroid hormone (PTH) via costimulatory molecules expressed on their surface. The conditioning effect of T cells on SCs is inherited by the osteoblastic and osteocytic progeny of SCs. As a result, osteoblastic cells of T cell-deficient mice have functional characteristics different from corresponding cells of T cell-replete mice. These differences include the ratio of RANKL/OPG produced in response to continuous PTH treatment, and the osteoblastogenic response to intermittent PTH treatment. This article reviews the evidence indicating that the effects of PTH are mediated not only by osteoblasts and osteocytes but also by T cells.

Regulatory effect of traditional Chinese medicinal formula Zuo-Gui-Wan on the Th17/Treg paradigm in mice with bone loss induced by estrogen deficiency

ETHNOPHARMACOLOGICAL RELEVANCE

Bone loss is a common pathological condition induced by estrogen deficiency. The Th17/Treg paradigm, which can be skewed by estrogen, plays an important role in regulating bone metabolism

AIM OF THE STUDY

The purpose of this study was to determine the role of the Th17/Treg shift in estrogen deficiency-induced bone loss in mouse models and to elucidate the immunopharmacologic mechanism of Zuo-Gui-Wan (ZGW) in preventing bone loss in this process by regulating Th17/Treg paradigm.

MATERIALS AND METHODS

Splenocytes of ovariectomized (Ovx) mice and naturally aged mice were isolated and Flow cytometry was used to detect the Th17/Treg subsets. In addition, serum estrodiol (E2) and serum C-terminal telopeptides of type Ι collagen (CTx) were detected by ELISA assay. Bone mineral density (BMD) of the left tibiae was measured by dual-energy X-ray absorptiometry. Moreover, Ovx mice were administrated with different doses of ZGW for 12 weeks, and BMD and Th17/Treg subsets were determined. Bone histomorphometry was observed by Hematoxylin and eosin (H&E) staining and serum protein levels of IL-6 were analyzed by ELISA assay. In addition, the mRNA and protein expression of RORγt and Foxp3 were detected by RT-PCR and Western blot respectively.

RESULT

The Th17/Treg paradigm shifted to Th17 in estrogen-deficient mice both in the Ovx mice and the naturally aged mice. BMD and E2 levels negatively correlated with the Th17/Treg ratio. After ZGW administration, the BMD was enhanced markedly in the Ovx mice as well as in the naturally aged mice. Both the mRNA and protein expressions of IL-6 and RORγt were decreased, whereas those of Foxp3 were increased significantly after ZGW administration.

CONCLUSION

Th17/Treg shift involved in the bone loss induced by estrogen deficiency. ZGW prevented bone loss efficiently and skewed Th17/Treg paradigm towards Treg without enhancing E2.

High prevalence of nickel allergy in an overweight female population: a pilot observational analysis

Context

In our Allergy Unit, we incidentally observed that a low Nickel diet, prescribed for delayed allergy to Nickel sulfate, reduced body mass index (BMI) and waist circumference in overweight patients.

Objectives

This pilot cross-sectional analysis was undertaken to compare the prevalence of Nickel allergy of overweight individuals versus the general population. We also had the chance to report the efficacy of a low Nickel diet on BMI and waist circumference in Nickel-sensitive overweight subjects.

Methods

Eighty-seven overweight subjects, with a BMI >26 Kg/m², were consecutively enrolled in a health prevention program, and screened for the presence of Nickel allergy. The enrolled population was mostly females (72/87) (82.8%). Forty-three overweight women and two men showed a Nickel allergy and started a low Nickel diet. After 6-months of dieting, 24 overweight allergic women could be traced and changes in BMI and waist circumference were calculated.

Main Outcome Measurements

Prevalence of Nickel allergy in overweight.

Results

Prevalence of Nickel allergy in overweight female was 59.7%, compared with a prevalence rate of 12.5% in the general population. A significant reduction in BMI was observed in 24 out of 43 overweight females with Nickel allergy after 24 weeks of a low Nickel diet. Relative to baseline, mean BMI decrease was 4.2±0.5 (P <0.001) and the mean decline in waist circumference was 11.7±0.6 cm (P< 0.001).

Conclusions

This pilot observational analysis showed a substantially higher prevalence of Nickel allergy among overweight females, especially those with metabolic syndrome and fatty liver disease. A normocaloric low Nickel diet was effective in reducing BMI in this population. Further research is strongly needed to confirm these preliminary findings.

Changes of serum cytokines-related Th1/Th2/Th17 concentration in patients with postmenopausal osteoporosis

BACKGROUND

Postmenopausal osteoporosis is now hypothetically considered to be an autoimmune and inflammatory process in which many pro-inflammatory and T cell-derived cytokines play important roles in the loss of bone mass. For instance, interleukin-2 (IL-2), interferon-γ (IFN-γ), and tumor necrosis factor-α (TNF-α) secreted by Th1 and IL-6, IL-4, and IL-10 secreted by Th2 have been shown to be involved in the pathogenesis of osteoporosis. Interleukin-17 (IL-17) is a characteristic cytokine secreted by Th17 cells of the CD4 + subgroup. Although IL-17 has been shown to enhance bone resorption in ovariectomized mouse model, bone cells and genetic research, human-related studies of IL-17 are few.

METHODS

According to WHO classification of osteoporosis by the T scores of BMD, the subjects were divided into the postmenopausal osteoporosis group (T scores≤-2.5), the postmenopausal osteopenia group (-2.5 < T scores<-1), and the postmenopausal normal BMD group (T scores≥-1); 30 subjects in each group. Cytometric bead array (CBA) technique was employed for serum determination of the primary indexes including IL-17A, IL-2, IFN-γ, TNF-α, IL-6, IL-4, and IL-10 concentrations in the 90 volunteers. In the meantime, serum calcium, phosphorus, magnesium, and alkaline phosphatase concentrations were also determined in the patients. One-way analysis of variance (one-way ANOVA) was employed in data analysis to determine whether the testing results of various parameters had significant differences. The bivariate correlation was tested with the Pearson correlation coefficient. When p < 0.05, the difference was considered to have statistical significance.

RESULTS

Serum IL-17A concentration was significantly higher in the postmenopausal osteoporosis group than in the postmenopausal osteopenia group and the postmenopausal normal BMD group, but the difference between the postmenopausal osteopenia group and the postmenopausal normal BMD group had no statistical significance. IL-17A was negatively correlated with BMD. To our knowledge, we discovered for the first time that serum concentrations of IFN-γ and IL-4 were significantly lower in the postmenopausal osteoporosis group than in the postmenopausal normal BMD group; IFN-γ and IL-4 were positively correlated with BMD. In addition, we also determined that BMI was negatively correlated with BMD; IL-17A was positively correlated with serum calcium. However, no significant differences in IL-6, TNF-α, IL-2, and IL-10 were observed among the three groups; these three factors were not correlated with BMD.

CONCLUSIONS

Our experiments have confirmed the roles of IL-17 in the pathogenesis of postmenopausal osteoporosis and in the promotion of bone resorption. Targeted therapy of IL-17, IFN-γ, and IL-4 may be beneficial in the treatment of patients with postmenopausal osteoporosis. Our experiments have also confirmed the roles of IFN-γ and IL-4 in the pathogenesis of postmenopausal osteoporosis and in the inhibition of bone resorption.

IL-17A-mediated sRANK ligand elevation involved in postmenopausal osteoporosis

The role of proinflammatory IL-17 cytokine was studied in postmenopausal bone loss between 31 osteopenic and 41 osteoporotic women. The effect of serum IL-17A, soluble receptor activator of NF-κB (sRANK) ligand, and osteoprotegerin (OPG) levels on lumbar bone mineral densities was measured. The results demonstrated an increased IL-17A-mediated sRANK ligand elevation in postmenopausal osteoporotic bone loss.

INTRODUCTION

IL-17 proinflammatory cytokine is a new inducer of bone loss. Postmenopausal osteoporosis represents a cross talk between estrogen deprivation and increased immune reactivity. The role of IL-17 was studied in the bone loss of postmenopausal osteoporosis.

METHODS

Serum IL-17A, sRANK ligand, and OPG levels were investigated on bone mineral densities (BMDs) in the total lumbar (L1-L4) region in 18 pre- and 72 postmenopausal women. IL-17A, sRANK ligand, OPG levels, and BMDs were measured with enzyme-linked immunosorbent assay (ELISA) and dual-energy X-ray absorptiometry (DXA).

RESULTS

Increased serum IL-17A, sRANK ligand, and OPG levels were demonstrated in postmenopausal osteoporotic women compared to osteopenic women (3.65 ± 0.61 vs 3.31 ± 0.43 ng/ml for IL-17A, P < 0.007; 2.88 ± 0.84 vs 2.49 ± 0.61 ng/ml for sRANK ligand, P < 0.027; and 1.43 ± 0.07 vs 1.39 ± 0.07 ng/ml for OPG, P < 0.038). In postmenopausal women, IL-17A levels correlated inversely with total lumbar BMDs (P < 0.008, r = -0.279) and positively with sRANK ligand levels (P < 0.0001, r = 0.387) or the ratio of sRANK ligand and OPG (P < 0.013, r = 0.261), but did not with OPG levels alone.

CONCLUSION

Increased IL-17A levels are involved in postmenopausal osteoporosis, playing a role in the bone-resorpting processes.