A role for sex steroids in autoimmune diseases: a working hypothesis and supporting data

Primary antiphospholipid syndrome during aromatase inhibitors therapy: A case report and review of the literature

RATIONALE

Aromatase inhibitors (AIs) are a class of drugs widely used in the treatment of estrogen sensitive breast and ovarian cancer which convert testosterone to estradiol and androstenedione to estrogen. The AIs of third generation, including anastrazole, letrozole and exemestane, have actually become the standard of care of estrogen-receptor-positive breast cancer in menopausal women and are recommended as adjuvant treatment after surgery in place of/or following tamoxifen. Their main side-effects include reduction in bone mineral density, occurrence of menopausal manifestations and development of musculoskeletal symptoms which are, usually, transient, but sometimes evolve into a typical form of arthritis, such as rheumatoid arthritis (RA). Recently, a pathogenic linkage with other autoimmunity diseases, such as Sjogren syndrome (SjS), anti-synthetase antibody syndrome (ASAS), systemic sclerosis (SS) and subacute cutaneous lupus erythematosus (SCLE), was also described.

PATIENT CONCERNS

Here, we report the first case of a patient with primary antiphospholipid syndrome (APS) developed during treatment with anastrazole.

DIAGNOSIS

The patient developed a sudden onset of speech disturbance and disorientation, due to ischemic lesions, after 6 months of AIs therapy and the laboratory examination showed the positivity of anti-Cardiolipin antibodies, anti-β2 Glycoprotein 1 antibodies and Lupus Anticoagulant, so a certain diagnosis of APS was achieved.

INTERVENTIONS

The patient was treated with warfarin associated to hydroxychloroquine and monthly cycles of low doses intravenous immunoglobulins.

OUTCOMES

A good control of the disease was obtained despite the continuation of anastrazole; the patient's clinical and laboratory situation remained not modified after AIs withdrawal.

LESSONS

We discussed the possible role of anastrazole treatment in inducing APS in our patient, reporting the available literature data about the association between AIs treatment and autoimmune diseases. Furthermore, we analyzed the mechanism of action of estrogens in the pathophysiology of autoimmune rheumatic disorders.

An intracrine view of sex steroids, immunity, and metabolic regulation

Background

Over the past two decades, parallel recognition has grown of the importance of both sex steroids and immune activity in metabolic regulation. More recently, these discrete areas have been integrated in studies examining the metabolic effects of sex steroid immunomodulation. Implicit in these studies has been a traditional, endocrine model of sex steroid delivery from the gonads to target cells, including immune cells. Thus, research to date has focused on the metabolic effects of sex steroid receptor signaling in immune cells. This endocrine model, however, overlooks the extensive capacity of immune cells to generate and metabolize sex steroids, enabling the production of sex steroids for intracrine signaling – that is, sex steroid production for signaling within the cell of origin. Intracrine function allows highly cell-autonomous regulation of sex steroid exposure, and sex steroid secretion by immune cells could confer paracrine signaling effects in neighboring cells within metabolic tissues. In this review, immune cell intracrinology will denote sex steroid production within immune cells for either intracrine or paracrine signaling. This intracrine capacity of immune cells has been well established, and prior work has supported its importance in autoimmune disorders, trauma, and cancer. The potential relevance of immune cell intracrine function to the regulation of energy balance, body weight, body composition, and insulin sensitivity has yet to be explored.

Scope of review

The following review will detail findings to date regarding the steroidogenic and steroid metabolizing capacity of immune cells, the regulation of immune cell intracrine function, and the biological effects of immune-derived sex steroids, including the clinical relevance of immune cell intracrinology in fields other than metabolism. These findings will serve as the basis for a proposed model of immune cell intracrinology constituting a new frontier in metabolism research.

Major conclusions

The development of highly sensitive mass spectrometric methods for sex steroid measurement and quantitation of metabolic flux now allows unprecedented ability to interrogate sex steroid production, metabolism and secretion by immune cells. Immune cell intracrinology could reveal key mechanisms underlying immune cell-mediated metabolic regulation.

•

Sex steroids exert immunomodulatory effects that may influence metabolic health.

•

Immune cells can synthesize, modify, and metabolize sex steroids.

•

Immune cell-derived sex steroids may play intracrine, autocrine, paracrine, and possibly even endocrine roles.

•

Immune cell steroidogenesis is a largely unexplored area of metabolism research.

The interaction between psychological health and traumatic brain injury: a neuroscience perspective

The occurrence of traumatic brain injury (TBI) and psychological health issues in the current theater of military operations has become a major factor in planning for the long-term healthcare of our wounded warriors. Post-traumatic stress disorder (PTSD) can co-exist with brain injury in military members who have been exposed to blasts. Specific areas of the brain may be more susceptible to damage from blasts. In particular, damage to the prefrontal cortex can lead to disinhibition of cerebral structures that control fear and anxiety. Reactive systemic inflammatory processes related to TBI may also impair psychological health. Impaired psychological health may lead to increased psychological distress that impedes brain repair due to the release of stress-related hormones. Since the external environment has been shown to exert a significant influence on the internal environment of the organism, enriching the external environment may well reduce anxiety and facilitate the neuroplasticity of brain cells, thus promoting recovery of function after TBI.

Signal transducer and activation of transcription (STAT) 4beta, a shorter isoform of interleukin-12-induced STAT4, is preferentially activated by estrogen

Estrogen, a natural immunomodulatory compound, has been shown to promote the induction of a prototype T helper 1 cytokine, interferon (IFN)-gamma, as well as to up-regulate IFNgamma-mediated proinflammatory molecules (nitric oxide, cyclooxygenase 2, monocyte chemoattractant protein 1). Because IL-12 is a major IFNgamma-inducing cytokine, in this study we investigated whether estrogen treatment of wild-type C57BL/6 mice alters IL-12-mediated signaling pathways. A recent study has shown that IL-12 activates two isoforms of signal transducer and activation of transcription (STAT) 4, a normal-sized (full-length STAT4alpha) and a truncated form (STAT4beta). Interestingly, we found that estrogen treatment preferentially up-regulates the phosphorylation of STAT4beta in splenic lymphoid cells. Time kinetic data showed the differential activation of STAT4beta in splenic lymphoid cells from estrogen-treated mice, but not in cells from placebo controls. The activation of STAT4beta was mediated by IL-12 and not IFNgamma because deliberate addition or neutralization of IL-12, but not IFNgamma, affected the activation of STAT4beta. In contrast to IL-12-induced activation of STAT4beta in cells from estrogen-treated mice, STAT4alpha was not increased, rather it tended to be decreased. In this context, STAT4alpha-induced p27(kip1) protein was decreased in concanavalin A + IL-12-activated lymphocytes from estrogen-treated mice only. By using the in vitro DNA binding assay, we confirmed the ability of pSTAT4beta to bind to the IFNgamma-activated sites (IFNgamma activation sequences)/STAT4-binding sites in estrogen-treated mice. Our data are the first to show that estrogen apparently has selective effects on IL-12-mediated signaling by preferentially activating STAT4beta. These novel findings are likely to provide new knowledge with regard to estrogen regulation of inflammation.

27-Hydroxycholesterol: a potential endogenous regulator of estrogen receptor signaling

The selective estrogen receptor modulators (SERMs) are synthetic pharmaceuticals, the relative agonist and antagonist activities of which are not equivalent in all cells. Their discovery has raised the possibility that endogenous small molecules might exist that have similar properties and could have important physiological roles. In support of this hypothesis is the recent demonstration that the oxysterol 27-hydroxycholesterol (27HC) interacts with and modulates the transcriptional activity of both estrogen receptor (ER) subtypes and that the relative agonist and antagonist activity of 27HC is influenced by both cell and promoter context. Although there is limited information available on the role of 27HC in classical estrogen-responsive tissues, that which is available in animal models of cardiovascular disease and cellular models of breast cancer support a role for this ligand in ER signaling. These results provide an interesting potential link between cholesterol (and cholesterol metabolism) and ER function, the physiological and pathological importance of which remains to be determined.

Influence of gender and oral contraceptives intake on innate and inflammatory response. Role of neuroendocrine factors

The purpose of the present work was to determine differences between young men (M), and women in the follicular phase (W) and women taking oral contraceptives containing ethinylestradiol (CW) in the phagocytic process of neutrophils (chemotaxis, phagocytosis and microbicide capacity), in the serum concentrations of cytokines both pro-inflammatory (IFNgamma, TNFalpha, IL-12, IL-6, IL-8) and anti-inflammatory ones (IL-10 and IL-13), and in neuroendocrine factors with immunomodulatory capacity (estradiol, prolactin, cortisol, catecolamines and 72 kDa heat shock proteins, Hsp72). Men showed a lower phagocytosis and microbicide capacity than women, and less serum concentrations of the pro-inflammatory cytokines IL-6 and IL-8. CW neutrophils also showed a lower phagocytic capacity than W neutrophils, together with less serum IL-8 concentration. CW showed the highest serum concentration of IL-13. However, no statistical changes were observed in the pro-inflammatory cytokines: INF-gamma, TNF-alpha, IL-12 and in the anti-inflammatory cytokine IL-10. The greater anti-inflammatory status in CW than in W was parallel with lower concentrations of oestrogens. Cortisol, prolactin, and the extracellular Hsp72 seem to be involved in the gender- and contraceptives-induced differences in the inflammatory response. While cortisol (in general an immunosuppressive hormone) showed the highest values in CW, prolactin and Hsp72 (an immunopermissive factors) showed the lowest values in CW and M. Less clear is the participation of catecholamines in the gender-inflammatory differences.

The Multitasking Mast Cell: Positive and Negative Roles in the Progression of Autoimmunity

Among the potential outcomes of an aberrantly functioning immune system are allergic disease and autoimmunity. Although it has been assumed that the underlying mechanisms mediating these conditions are completely different, recent evidence shows that mast cells provide a common link. Mast cells reside in most tissues, are particularly prevalent at sites of Ag entry, and act as sentinel cells of the immune system. They express many inflammatory mediators that affect both innate and adaptive cellular function. They contribute to pathologic allergic inflammation but also serve an important protective role in bacterial and parasite infections. Given the proinflammatory nature of autoimmune responses, it is not surprising that studies using murine models of autoimmunity clearly implicate mast cells in the initiation and/or progression of autoimmune disease. In this review, we discuss the defined and hypothesized mechanisms of mast cell influence on autoimmune diseases, including their surprising and newly discovered role as anti-inflammatory cells.

beta(2)-Adrenergic receptor-dependent sexual dimorphism for murine leukocyte migration

In wild-type FVB mice, leukocyte recruitment to lipopolysaccharide was sexually dimorphic, with a greater number of leukocytes recruited in females. In male beta(2)-adrenergic receptor knock out mice (bred on a congenic FVB background) the number of leukocytes recruited was increased approximately 4-fold, while in females there was no change, eliminating sexual dimorphism in leukocyte migration. While there were significantly fewer recruited CD62L(+) and CD11a(+) leukocytes in wild-type males, only in male beta-adrenergic receptor knock out mice was there an increase in the number of recruited CD11a(+) leukocytes, again eliminating sexual dimorphism. Thus, leukocyte migration and CD11a(+) adhesion molecule expression in male, but not in female, leukocytes is beta-adrenergic receptor-dependent. Our findings provide support for a role of beta(2)-adrenergic receptor mechanisms in the inflammatory response, and suggest that beta(2)-adrenergic receptor on male leukocytes contributes to sexual dimorphism in the effect of stress on inflammatory diseases.

The Disease Activity Score in 28 joints in rheumatoid arthritis and psoriatic arthritis patients

OBJECTIVE

To assess the factorial structure of the Disease Activity Score including a 28-joint count (DAS28) if applied in patients with rheumatoid arthritis (RA) and psoriatic arthritis (PsA).

METHODS

DAS28 values from 85 consecutive PsA outpatients and 2 RA patient cohorts comprising 85 patients each were compared. The first RA cohort (RA1) consisted of age- and sex-matched patients seen during the same period as the patients with PsA. The first 85 RA outpatients from September 2003 were included in the second cohort (RA2). Item weighting, factor loading, and internal consistency were assessed by factor analysis, principal component analysis, and calculation of Cronbach's alpha.

RESULTS

The mean +/- SD DAS28 scores of patients in the PsA, RA1, and RA2 cohorts were 3.2 +/- 1.31, 3.21 +/- 1.45, and 3.79 +/- 1.44, respectively. A significant difference between the PsA and RA2 cohorts was found for DAS28 (P = 0.0063), swollen joint count (P = 0.007), and patient's global assessment (P < 0.001), but not for erythrocyte sedimentation rate. Internal consistency of the DAS28 in patients with PsA was considerably lower, item weighting showed remarkable differences, and factor analysis revealed that the DAS28 constitutes a bidimensional instrument in patients with PsA, whereas in both RA cohorts it appeared to be monodimensional.

CONCLUSION

With respect to its statistical properties, the DAS28 proved to be considerably different in PsA compared with RA. Therefore its application for disease activity assessment in patients with PsA cannot be recommended without a formal validation procedure.

Estrogen stimulates transcription of human immunodeficiency virus type 1 (HIV-1)

Gene expression from human immunodeficiency virus (HIV) provirus is a crucial step for the viral replication. Here we examined a potential role of 17beta-estradiol (E2) in HIV-1 transcription. Transient luciferase expression studies revealed that E2 activated HIV-LTR reporter gene in HEK293 cells when the cells were co-transfected with estrogen receptor alpha (ERalpha) but not ERbeta expression plasmid. This E2 effect was abrogated by a specific antagonist to ER, ICI 182,780, indicating that it was mediated by ERalpha. Mutation analysis revealed that Sp1 binding site but not nuclear factor-kappa B (NF-kappaB) binding site of HIV-1 LTR is critical to the E2 effect. In addition, whereas E2 could not induce DNA-binding activity of NF-kappaB, E2 could augment both Sp1 DNA-binding and transcriptional activity. These findings suggest a contribution of estrogen for HIV-1 replication through ERalpha by augmenting Sp1 DNA-binding and transcriptional activity.

Estrogen up-regulates inducible nitric oxide synthase, nitric oxide, and cyclooxygenase-2 in splenocytes activated with T cell stimulants: role of interferon-gamma

Estrogen is implicated in many autoimmune diseases and is a robust immunomodulator. For example, it regulates interferon (IFN)-gamma, a cytokine believed to up-regulate inducible nitric oxide synthase (iNOS). A notable gap in the literature is a lack of information on the regulation of nitric oxide in immune tissues by estrogen. We now show that activation of splenocytes with T cell stimulants [concanavalin-A (Con-A) or anti-CD3 antibodies] results in copious release of nitric oxide in splenocyte cultures from estrogen-treated but not placebo-treated mice. Moreover, even a low dose of T cell stimulants induced nitric oxide in splenocytes from estrogen-treated, but not placebo-treated, mice. Con-A-activated splenocytes from estrogen-treated mice also have up-regulated iNOS mRNA, iNOS protein, and cyclooxygenase-2 (a nitric oxide-regulated downstream proinflammatory protein) when compared with controls. Our studies suggest that the induction of nitric oxide by activated splenocytes from estrogen-treated mice is mediated in part by IFNgamma. First, blocking costimulatory signals mediated through interactions of CD28 and B7 molecules by CTLA-4Ig markedly decreased not only IFNgamma but also nitric oxide. Second, estrogen treatment of IFNgamma-knockout (IFNgamma(-)/(-)) mice did not induce iNOS protein or nitric oxide. Finally, in vitro addition of recombinant IFNgamma to Con-A-activated splenocytes from IFNgamma((-)/(-)) mice induced iNOS protein primarily in estrogen-treated mice. Overall, this is the first report to show that estrogen treatment up-regulates IFNgamma-inducible-iNOS gene expression, iNOS protein, nitric oxide, and cyclooxygenase-2 as an indirect consequence of activation of T cells. These findings may have wide implications to immunity and inflammatory disorders including female-predominant autoimmune diseases.

Combining a recombinant cancer vaccine with standard definitive radiotherapy in patients with localized prostate cancer

PURPOSE

Many patients with clinically localized prostate cancer develop biochemical failure despite excellent local therapy perhaps due to occult metastatic disease. One potential solution is the utilization of a well-tolerated systemic therapy (e.g., vaccine) in concert with local therapy.

EXPERIMENTAL DESIGN

We present a randomized phase II clinical trial designed to determine if a poxviral vaccine encoding prostate-specific antigen (PSA) can induce a PSA-specific T-cell response when combined with radiotherapy in patients with clinically localized prostate cancer. Thirty patients were randomized in a 2:1 ratio into vaccine plus radiotherapy or radiotherapy-only arms. Those patients in the combination arm received a "priming" vaccine with recombinant vaccinia (rV) PSA plus r V containing the T-cell costimulatory molecule B7.1 (rV-B7.1) followed by monthly booster vaccines with recombinant fowlpox PSA. The vaccines were given with local granulocyte-macrophage colony-stimulating factor and low-dose systemic interleukin-2. Standard external beam radiation therapy was given between the fourth and the sixth vaccinations.

RESULTS

Seventeen of 19 patients in the combination arm completed all eight vaccinations and 13 of these 17 patients had increases in PSA-specific T cells of at least 3-fold versus no detectable increases in the radiotherapy-only arm (P < 0.0005). There was also evidence of de novo generation of T cells to well-described prostate-associated antigens not found in the vaccine, providing indirect evidence of immune-mediated tumor killing. The vaccine was well tolerated.

CONCLUSION

This vaccine regimen can be safely given in patients undergoing radiation therapy for localized prostate cancer, with the majority of patients generating a PSA-specific cellular immune response to vaccine.

Estrogens and their receptors in breast cancer progression: a dual role in cancer proliferation and invasion

Estrogens play an important role in regulating the growth and differentiation of normal, premalignant and malignant cell types, especially breast epithelial cells, through interaction with two nuclear estrogen receptors (ERalpha and ERbeta). In this review, we present a brief overview of the actions of estrogens in the different steps of breast carcinogenesis, including cancer progression to metastasis, and of their clinical consequences in the prevention, prognosis and treatment of the disease. The requirement of estrogen receptors, mainly of the alpha subtype, in normal mammary gland differentiation and growth has been evidenced by estrogen receptor deficiency in animals. The promotion of breast cancer carcinogenesis by prolonged exposure to estrogens is well-documented and this has logically led to the use of anti-estrogens as potentially chemopreventive agents. In breast cancer progression, however, the exact roles of estrogen receptors have been less well established but they may possibly be dual. Estrogens are mitogenic in ER-positive cells and anti-estrogens are an efficient adjuvant therapy for these tumors. On the other hand, the fact that estrogens and their receptors protect against cancer cell invasiveness through distinct mechanisms in experimental models may explain why the presence of ER is associated with well-differentiated and less invasive tumors.

Beta 2-adrenergic receptor regulation of human neutrophil function is sexually dimorphic

While the mechanisms underlying the marked sexual dimorphism in inflammatory diseases are not well understood, the sexually dimorphic sympathoadrenal axis profoundly affects the inflammatory response. We tested whether adrenergic receptor-mediated activation of human neutrophil function is sexually dimorphic, since neutrophils provide the first line of defense in the inflammatory response. There was a marked sexual dimorphism in beta(2)-adrenergic receptor binding, using the specific beta(2)-adrenergic receptor ligand, [(3)H]-dihydroalprenolol, with almost three times more binding sites on neutrophils from females (20,878 +/- 2470) compared to males (7331 +/- 3179). There was also a marked sexual dimorphism in the effects of isoprenaline, a beta-adrenergic receptor agonist, which increased nondirected locomotion (chemokinesis) in neutrophils obtained from females, while having no effect on neutrophils from males. Isoprenaline stimulated the release of a chemotactic factor from neutrophils obtained from females, but not from males. This chemotactic factor acts on the G protein-coupled CXC chemokine receptor 2 (CXCR2) chemokine receptor, since an anti-CXCR2 antibody and the selective nonpeptide CXCR2 antagonist SB225002, inhibited chemotaxis produced by this factor. While interleukin- (IL-) 8 is a principal CXCR2 ligand, isoprenaline did not produce an increase in IL-8 release from neutrophils. IL-8-induced chemotaxis was inhibited in a sexually dimorphic manner by isoprenaline, which also stimulated release of a mediator from neutrophils that induced chemotaxis, that was inhibited by anti-CXCR2 antibodies. These findings indicate an important role for adrenergic receptors in the modulation of neutrophil trafficking, which could contribute to sex-differences in the inflammatory response.

Estradiol Treatment Redirects the Isotype of the Autoantibody Response and Prevents the Development of Autoimmune Arthritis

A number of clinical and experimental observations have been made relating elevated estrogen levels with the amelioration of autoimmune diseases, yet questions remain about the levels required for efficacy as well as the mechanism of disease inhibition. Using the collagen-induced arthritis (CIA) model, we have studied the effects of physiological, sustained levels of 17beta-estradiol in preventing the development of autoimmune arthritis and analyzed the changes in the autoimmune response. Using time-release pellets of 17beta-estradiol, arthritis development was significantly inhibited in three different strains of CIA-susceptible mice compared with the effect of placebo treatment, and serum estradiol levels similar to those of mice in estrus were found to be equally effective as higher estradiol concentrations. Analysis of the autoimmune response in the estradiol-treated mice indicated that T cell production of IFN-gamma was markedly decreased, and significant decreases were also observed in levels of IL-10 and GM-CSF produced by lymph nodes cells from estradiol-treated mice. Although the total IgG anti-CII response was only minimally affected by estrogen treatment, a significant reduction in the levels of IgG2a anti-CII Abs and an increase in the levels of IgG1 anti-CII Abs were observed in estradiol-treated mice. These data indicate that estradiol treatment altered the Th profile of the autoimmune T cell response, which, in turn, altered the production of IgG Abs to an isotype that is poor at fixing complement, an important component in the immunopathogenesis of CIA.

Evolution of the thymus size in response to physiological and random events throughout life

During embryogenesis and in the early stages of life, the thymus is a crucial organ for the generation of the T cell repertoire. T cells are generated from hematopoietic stem cells already differentiated to precursor T cells in the bone marrow. These cells enter the thymus guided by chemotactic factors secreted by this organ. The complex maturation process takes place that ensures self-tolerance and homeostasis. Thymocytes that show autoreactivity do not leave the thymus, but rather die by apoptosis. The final percentage of mature T cells that survive to migrate from the thymus to the periphery is very low: at most 5%, under optimal conditions. The highest migration occurs in childhood and adulthood, at least in mice and humans; however, it declines throughout life and is minimal in the elderly. Under normal circumstances, the thymus commences involution soon after birth, and this involution correlates with the capacity to export mature T cells to the periphery. Hormones, cytokines, and neurotransmitters all play a role in this age-associated process, but the reasons for and mechanisms of this involution remain unknown. Apart from physiological conditions that change throughout life and govern age-related thymus evolution, random states and events provoked by intrinsic or extrinsic factors can induce either thymus involution, as in reversible transient thymic hypoplasias, or thymic hyperplasias. The age-associated involution, unlike transient involutions, follows a regular pattern for all individuals, though there are clear differences between the sexes. Nevertheless, even the age-associated involution seems to be reversible, raising the possibility of therapeutic strategies aimed at enhancing thymus function in the elderly.