Gonadotropin-releasing hormone alters the T helper cytokine balance in the pregnant rat

Thrombo-inflammation linking androgen suppression with cardiovascular risk in patients with prostate cancer

Androgen deprivation therapy (ADT), a key element of prostate cancer treatment, is associated with increased risk for cardiovascular morbidity and mortality. The underlying mechanisms include adverse metabolic alterations, but further mechanisms are likely. Animal studies suggest increased progression of atherosclerosis in androgen deprived conditions. Based on in vitro studies, lack of androgens may modulate immune cells including monocytes, macrophages, and T-cells towards a pro-inflammatory phenotype and pro-atherogenic function. As a novel aspect, this review summarizes existing data on the effect of androgens and androgen deprivation on platelet activity, which play a major role in inflammation and in the initiation and progression of atherosclerotic lesions. Testosterone modulates platelet aggregation responses which are affected by dose level, source of androgen, and age. Data on the effects of ADT on platelet activity and aggregation are limited and conflicting, as both increased and decreased aggregation responses during ADT have been reported. Gaps in knowledge about the mechanisms leading to increased cardiovascular risk during ADT remain and further research is warranted. Improved understanding of pathogenic pathways linking ADT to cardiovascular risk may help identify clinically useful diagnostic and prognostic biomarkers, and accelerate finding novel therapeutic targets, and thus optimize prostate cancer treatment outcomes.

Gonadotropin-releasing hormone agonist treatment and ischemic heart disease among female patients with breast cancer: A cohort study

BACKGROUND

The risk of ischemic heart disease (IHD) due to the impact of gonadotropin-releasing hormone (GnRH) agonists among female patients with breast cancer remains a controversy.

METHODS

Information from the Registry for Catastrophic Illness, the National Health Insurance Research Database (NHIRD), and the Death Registry Database in Taiwan were analyzed. Female patients with breast cancer were selected from the Registry for Catastrophic Illness from January 1, 2000, to December 31, 2018. All the breast cancer patients were followed until new-onset IHD diagnosis, death, or December 31, 2018. A Kaplan-Meier survival curve was drawn to show the difference between patients treated with and without GnRH agonists. The Cox regression analysis was used to investigate the effects of GnRH agonists and the incidence of IHD.

RESULTS

A total of 172,850 female patients with breast cancer were recognized with a mean age of 52.6 years. Among them, 6071(3.5%) had received GnRH agonist therapy. Kaplan-Meier survival curves showed a significant difference between patients with and without GnRH therapy (log-rank p < 0.0001). Patients who received GnRH therapy had a significantly decreased risk of developing IHD than those without GnRH therapy (HR = 0.18; 95% CI = 0.14-0.23). After adjusting for age, treatment, and comorbidity, patients who received GnRH therapy still had a significantly lower risk of developing IHD (AHR = 0.5, 95% CI = 0.39-0.64).

CONCLUSION

The study showed that the use of GnRH agonists for breast cancer treatment was significantly associated with a reduced risk of IHD. Further research is required to investigate the possible protective effect of GnRH on IHD.

Association between GnRH analogue use and atopic diseases in patients with prostate cancer: A population-based retrospective cohort study

Purpose

Gonadotropin-releasing hormone (GnRH) analogues reduce testosterone levels to castration levels in patients with prostate cancer. However, the role of testosterone in atopic diseases has remained undefined. We aimed to investigate this role.

Materials and methods

This retrospective cohort study was conducted using the National Health Insurance Research Database (NHIRD). Patients with prostate cancer were categorized into two groups according to whether they received GnRH analogue treatment (study group I) or not (study group II), and men without prostate cancer and with no GnRH analogue use were defined to comprise the comparison group after their ages and index years were matched with group II. Cox proportional hazard models were used to assess the hazard ratio (HR) of atopic diseases.

Results

Group I, group II, and the comparison group comprised 663, 2,172, and 8,688 individuals, respectively. Group I had a significantly lower risk of atopic diseases (adjusted HR: 0.66, 95% CI, 0.49–0.89, p < 0.01) than did group II. A reduced risk of atopic diseases was found when GnRH analogues were prescribed for 2 months (adjusted HR 0.53, 95% CI, 0.29–0.97, p = 0.04) and 2–14 months (adjusted HR 0.66, 95% CI, 0.49–0.89, p = 0.007). No significant difference in the risk of atopic diseases between group II and the comparison group was observed.

Conclusions

A decreased risk of atopic diseases was observed in patients with prostate cancer treated with GnRH analogues. Further studies are warranted to verify the association between testosterone levels and atopic diseases.

Gut Barrier Dysfunction and Type 2 Immunity: Implications for Compulsive Behavior

To date, much of the focus of gut-brain axis research has been on gut microbiota regulation of anxiety and stress-related behaviors. Much less attention has been directed to potential connections between gut microbiota and compulsive behavior. Here, we discuss a potential link between gut barrier dysfunction and compulsive behavior that is mediated through "type 2" rather than "type 1" inflammation. We examine connections between compulsive behavior and type 2 inflammation in Tourette syndrome, obsessive-compulsive disorder, autism, addiction, and post-traumatic stress disorder. Next, we discuss potential connections between gut barrier dysfunction, type 2 inflammation, and compulsive behavior. We posit a potential mechanism whereby gut barrier dysfunction-associated type 2 inflammation may drive compulsive behavior through histamine regulation of dopamine neurotransmission. Finally, we discuss the possibility of exploiting the greater accessibility of the gut relative to the brain in identifying targets to treat compulsive behavior disorders.

How neuroactive factors mediates immune responses during pregnancy: An interdisciplinary view

Pregnancy, from insemination to parturition, is a highly complex but well-orchestrated process that requires various organs and systems to participate. Immune system and neuroendocrine system are important regulators in healthy pregnancy. Dozens of neuroactive factors have been detected in human placenta, whether they are locally secreted or circulated. Among them, some are vividly studied such as corticotropin-releasing hormone (CRH), human chorionic gonadotropin (hCG), transforming growth factor-β (TGF-β), progesterone and estrogens, while others are relatively lack of research. Though the neuroendocrine-immune interactions are demonstrated in some diseases for decades, the roles of neuroactive factors in immune system and lymphocytes during pregnancy are not fully elucidated. This review aims to provide an interdisciplinary view on how the neuroendocrine system mediate immune system during pregnancy process.

Increased testosterone and proinflammatory cytokines in patients with polycystic ovary syndrome correlate with elevated GnRH receptor autoantibody activity assessed by a fluorescence resonance energy transfer-based bioassay

PURPOSE

The recently identified agonistic autoantibodies (AAb) to the gonadotropin-releasing hormone receptor (GnRHR) are a novel investigative and therapeutic target for polycystic ovary syndrome (PCOS). In this study, we used a new cell-based fluorescence resonance energy transfer (FRET) bioassay to analyze serum GnRHR-AAb activity and examine its relationship with testosterone and proinflammatory cytokines in patients with PCOS.

METHODS

Serum samples from 33 PCOS patients, 39 non-PCOS ovulatory infertile controls and 30 normal controls were tested for GnRHR-AAb activity and proinflammatory cytokines in a FRET-based bioassay and multiplex bead-based immunoassay, respectively. Correlation was analyzed using the Spearman's correlation test.

RESULTS

Serum GnRHR-AAb activity was significantly higher in the PCOS patients than for the ovulatory infertile (p < 0.05) and normal (p < 0.01) controls. GnRHR-AAb were positive in 39% of PCOS patients, 10% of ovulatory infertile controls, and 0% of normal controls. PCOS IgG-induced GnRHR activation was specifically blocked by the GnRHR antagonist cetrorelix. Serum levels of proinflammatory cytokines interleukin-2, interleukin-6, interferon-γ, and tumor necrosis factor-α were significantly increased in PCOS patients compared with ovulatory infertile and normal controls (p < 0.01). Correlation analysis demonstrated positive correlations of GnRHR-AAb activity with testosterone and proinflammatory cytokine levels in the PCOS group.

CONCLUSIONS

Elevated GnRHR-AAb activity, as assessed by a new FRET assay, is associated with increased testosterone and proinflammatory cytokines in PCOS, suggesting autoimmune activation of GnRHR may contribute to the pathogenesis of this common disorder.

Cardiovascular Toxicities of Androgen Deprivation Therapy

OPINION STATEMENT

Prostate cancer is the second leading cause of cancer death in men, and cardiovascular disease is the number one cause of death in patients with prostate cancer. Androgen deprivation therapy, the cornerstone of prostate cancer treatment, has been associated with adverse cardiovascular events. Emerging data supports decreased cardiovascular risk of gonadotropin releasing hormone (GnRH) antagonists compared to agonists. Ongoing clinical trials are assessing the relative safety of different modalities of androgen deprivation therapy. Racial disparities in cardiovascular outcomes in prostate cancer patients are starting to be explored. An intriguing inquiry connects androgen deprivation therapy with reduced risk of COVID-19 infection susceptibility and severity. Recognition of the cardiotoxicity of androgen deprivation therapy and aggressive risk factor modification are crucial for optimal patient care.

Comparing the risk of cardiovascular disease following GnRH agonist and GnRH antagonist therapy for patient with prostate cancer: a systematic review and meta-analysis

INTRODUCTION

The aim of this review is to compare the risk of cardiovascular disease (CVD) following gonadotropin-releasing hormone (GnRH) agonist and GnRH antagonist therapy for patient with prostate cancer (PCa).

EVIDENCE ACQUISITION

We searched PubMed, Web of science, Opengery, Cochrane library databases and international congress reports for studies published before December 2019. This meta-analysis was conducted using Stata v. 12.0. Relative ratios (RRs) and their credible intervals (CI) were applied for the cardiovascular safety evaluation of androgen-deprivation therapy (ADT) medical interventions, including GnRH agonist and GnRH antagonist therapy. In addition, fixed-effect or random-effect models were applied in the statistical analyses according to the heterogeneity.

EVIDENCE SYNTHESIS

Six articles including 32,997 participants were analyzed with a random effects model. The results of meta-analysis showed that compared with GnRH agonist, the incidents of CVD was equal to GnRH antagonist therapy for patient with PCa (RR=0.98, 95% CI: 0.94-1.02). When considering, under sub-group analysis with randomized controlled trials (RCTs) or controlled clinical trials (CCTs), no statistical differences in risk of CVD were found in two sub-group analyses. No evidence of publication bias was found in our meta-analysis by a funnel plot (Pr> | z |=0.26).

CONCLUSIONS

This meta-analysis indicates that compared treatment with GnRH antagonist, risks of CVD in PCa patients was the same as GnRH agonist. Further RCTs are strongly required to provide more definitive evidence.

Degarelix versus luteinizing hormone-releasing hormone agonists for the treatment of prostate cancer

INTRODUCTION

Androgen deprivation therapy (ADT) is the mainstay for advanced, hormone-sensitive prostate cancer, and options include surgical castration, luteinizing hormone-releasing hormone (LHRH) agonist, and more recently, gonadotropin releasing hormone (GnRH) antagonist therapy. Our understanding of the mechanisms and adverse effects of ADT has increased substantially, including the class-specific adverse effects of ADT. Areas covered: This review will summarize the pharmacodynamic and pharmacokinetic properties of the GnRH antagonist degarelix and its role in the management of advanced prostate cancer, the clinical evidence supporting its regulatory approval, as well as potential benefits and disadvantages over traditional LHRH agonist therapy. Expert opinion: Degarelix represents a newer class of ADT that results in a rapid and reliable decline in serum testosterone, a quality that makes it particularly advantageous in men presenting with symptomatic, hormone-sensitive prostate cancer. Due to differences in mechanism of action, there is observational data suggesting a potential cardiovascular and even oncologic benefit over traditional LHRH agonist therapy. Further research is ongoing to more clearly define this potential benefit.

Approach to Androgen Deprivation in the Prostate Cancer Patient with Pre-existing Cardiovascular Disease

PURPOSE OF REVIEW

Androgen deprivation therapy (ADT) is a mainstay of treatment for advanced prostate cancer. Several studies have reported an association between ADT and an increase in cardiovascular events, especially in those receiving gonadotropin-releasing hormone (GnRH) agonists compared to GnRH antagonists. We review the body of literature reporting the association of ADT and cardiovascular morbidity, and discuss the proposed mechanism of cardiovascular disease due to ADT including metabolic changes that may promote atherosclerosis and local hormonal effects that may increase plaque rupture and thrombosis.

RECENT FINDINGS

GnRH agonists appear to increase the risk of cardiovascular morbidity by 20-25% in men on these agents compared those who do not receive ADT. GnRH antagonists may appear to have halve this risk while improving PSA progression-free survival. GnRH antagonists may be superior to GnRH agonists for patients with significant cardiovascular disease, significant metastatic disease burden, or severe lower urinary tract symptoms.

Effect of gonadotropin-releasing hormone vaccination on T lymphocyte changes in male rats

The aim of this study was to detect the effect of immunization against gonadotropin-releasing hormone (GnRH) on cell-meditated immunity. Three-week-old male Sprague-Dawley rats (n=32) were randomly and equally assigned to two groups: 1) GnRH-tandem-ovalbumin immunized group; and 2) the control group (injected with an equivalent Al(OH)₃ adjuvant). Blood samples were collected at two-week intervals to assess the level of GnRH-specific antibodies and testosterone. Moreover, blood and thymus samples were also collected to analyze the T lymphocyte subpopulations one and two months after the last booster immunization. T lymphocyte immunity against GnRH was activated during the first month post-immunization as exhibited by increased numbers of CD3+ (P<0.05) and CD4+ (P<0.05)T lymphocytes following testosterone suppression (P<0.01), which was then restored and maintained at appropriate levels in the second month. In contrast, the differentiation of T lymphocytes in the thymus was reduced during the first month after immunization as exhibited by the significant decreased number of CD3+ (P<0.05) cells, followed by the restoration and heightened numbers at later time points for both the number of CD3+ (P<0.05) and CD4+ (P<0.01)T lymphocytes. These results suggest that immunization against GnRH interferes with the number of lymphocytes during the early time points following immunization. The number of T lymphocytes initially decreased in the peripheral blood following immunization, but was replenished by newly exported cells from the thymus which eventually restored the T lymphocytes to normal levels.

A meta-analysis of cardiovascular events in intermittent androgen-deprivation therapy versus continuous androgen-deprivation therapy for prostate cancer patients

BACKGROUND

Androgen-deprivation therapy (ADT) is the standard treatment for advanced and recurrent prostate cancer but it has been shown to cause adverse effects on the cardiovascular system. Intermittent androgen deprivation has been studied as an alternative therapy. To conduct a meta-analysis comparing the incidence of cardiovascular events in patients with prostate cancer receiving intermittent (IADT) versus continuous ADT (CADT).

METHODS

We searched Cochrane CENTRAL, PubMed/Medline, Embase, Web of Science, The National Cancer Institute Clinical Trials and The Clinical Trials Register of Trials Central, and Google Scholar from inception of each database through February 2016. References from published guidelines, reviews and other relevant articles were also considered. We selected randomized clinical trials comparing IADT versus CADT in patients with prostate cancer that reported data on cardiovascular events. Two reviewers performed the study selection, data abstraction and risk of bias assessment. We calculated risk ratios with the Mantel-Haenszel method, using random effect models. We assessed heterogeneity using I² index. The primary outcome was incidence of cardiovascular events. Secondary outcomes were thromboembolic events and cardiovascular-related mortality.

RESULTS

Out of 106 references, we included seven articles from six trials (4810 patients) published between 2009 and 2015. We observed no significant difference between intermittent versus continuous androgen deprivation with respect to cardiovascular events (risk ratio (RR): 0.95; confidence interval (CI) 95%=0.83-1.08; seven trials, 4810 patients) and thromboembolic events (RR: 1.05; CI 95%=0.85-1.30; three trials, 1816 patients). There was marginally significant difference with respect to cardiovascular-related mortality (RR: 0.85; CI 95%=0.71-1.00; five trials, 4170 patients).

CONCLUSIONS

Compared with CADT, IADT shows no difference in terms of cardiovascular events and thromboembolic events. However, there was an association between lower cardiovascular-related mortality and intermittent androgen deprivation.

[Castration modalities in prostate cancer: Are they all equal?]

AIM

The aim of this literature review was to focus on the new highlights regarding oncologic and safety outcomes depending on the type of castration used.

MATERIAL

Literature search using various algorithms "prostate cancer", "castration", "agonist", "antagonist", "orchiectomy", "GnRH", "FSH", "androgen deprivation therapy" has been performed in April 2015, through the PubMed and Embase databases.

RESULTS

GnRH agonists and antagonists are both currently used in clinical practice. Nevertheless, differences regarding their pharmacologic properties have been highlighted in recent studies, specifically regarding the rapidity, sustainability and depth of the castration, but also the decrease in FSH level. Such differences may have oncological impact on the patient, regarding the disease biological control and the time to progression, and a tolerability impact, especially on the cardiovascular risks. The role of the depth and the sustainability of the castration in one hand, the FSH impact in the other hand, as well as a direct inhibition on extra-pituitary GnRH receptors by antagonist might explain these differences.

CONCLUSIONS

Recent studies suggest differences between GnRH agonists and antagonist that could impact the patient clinical outcomes. However, further high level of evidence comparative studies remains warranted.

Differences in Hypercholesterolemia and Atherogenesis Induced by Common Androgen Deprivation Therapies in Male Mice

BACKGROUND

Treatment of prostate cancer often involves androgen deprivation therapy (ADT) by gonadotropin-releasing hormone (GnRH) receptor agonists, GnRH receptor antagonists, or orchiectomy. ADT may increase the rate of cardiovascular disease events, but recent clinical studies suggested that not all means of ADT carry the same risk, raising the possibility of non-testosterone-mediated effects of different forms of ADT on atherosclerosis. Here we compared effects of ADT on atherosclerosis in intact and orchiectomized Apoe-deficient mice.

METHODS AND RESULTS

Chow-fed Apoe-deficient mice were allocated to orchiectomy and/or monthly injections with the GnRH receptor agonist leuprolide or the GnRH receptor antagonist degarelix. Atherosclerosis was quantified at 26 weeks of age in the aortic arch by en face examination and in the aortic root by histology. In intact Apoe-deficient mice, all types of ADT reduced testosterone production to castration levels. Although hypercholesterolemia was accentuated in leuprolide-treated mice, the amount and composition of atherosclerosis was not different between the different types of ADT. In orchiectomized Apoe-deficient mice, leuprolide, but not degarelix, augmented hypercholesterolemia, changed body, thymus, and spleen weights, and increased atherosclerosis in the aortic root. No direct effects of the drugs were detectable on cytokine secretion from murine bone marrow-derived macrophages or on splenocyte proliferation.

CONCLUSIONS

No differences in the development of atherosclerosis were detected among groups of intact Apoe-deficient mice treated with different types of ADT. A pro-atherogenic, possibly cholesterol-mediated, effect of leuprolide was seen in orchiectomized mice that might be relevant for understanding the potential cardiovascular risk associated with GnRH agonist-based ADT.

Pharmacokinetic and pharmacodynamic profile of degarelix for prostate cancer

INTRODUCTION

Luteinizing hormone-releasing hormone (LHRH) agonists have been the mainstay of androgen deprivation therapy (ADT) for advanced prostate cancer for over two decades. However, their limitations include a transient initial rise in testosterone, failure to reduce testosterone to castrate levels in some patients, incomplete suppression of follicle-stimulating hormone (FSH), and an increased risk of cardiovascular (CV) events in those with pre-existing CV disease. This article considers whether the LHRH antagonist degarelix offers significant advantages over LHRH agonists.

AREAS COVERED

This review covers the development and introduction of degarelix, its pharmacodynamic and pharmacokinetic properties, and the efficacy and safety results of Phase II and III clinical studies.

EXPERT OPINION

Degarelix has clear pharmacodynamic advantages over the LHRH agonist leuprolide in terms of almost immediate suppression of testosterone to castrate levels and sustained suppression of FSH levels. It reduces the risk of CV events vs agonists in men with pre-existing CV disease. This finding, which may reflect differential effects on FSH and/or endothelial plaques, requires confirmation in a prospective study; however, it is the view of the author that the differential effects on CV events are real and suggest that men with pre-existing CV disease requiring ADT should preferentially be treated with degarelix.

Gonadotropin-releasing hormone agonists and acute kidney injury in patients with prostate cancer

BACKGROUND

Androgen deprivation therapy (ADT) might increase the risk of acute kidney injury (AKI) in patients with prostate cancer (PCa).

OBJECTIVE

To examine the impact of ADT on AKI in a large contemporary cohort of patients with nonmetastatic PCa representing the US population.

DESIGN, SETTING, AND PARTICIPANTS

Overall, 69 292 patients diagnosed with nonmetastatic PCa between 1995 and 2009 were abstracted from the Surveillance Epidemiology and End Results-Medicare database.

OUTCOMES MEASUREMENTS AND STATISTICAL ANALYSES

Patient in both treatment arms (ADT vs. no ADT) were matched using propensity-score methodology. Ten-year AKI rates were estimated. Competing-risks regression analyses tested the association between ADT and AKI, after adjusting for the risk of death during follow-up.

RESULTS AND LIMITATIONS

Overall, the 10-yr AKI rates were 24.9% versus 30.7% for ADT-naive patients versus those treated with ADT, respectively (p<0.001). When patients were stratified according to the type of ADT, the 10-yr AKI rates were 31.1% versus 26.0% for men treated with gonadotropin-releasing hormone (GnRH) agonists and bilateral orchiectomy, respectively (p<0.001). In multivariable analyses, the administration of GnRH agonists (hazard ratio [HR]: 1.24; 95% confidence interval [CI], 1.18-1.31; p<0.001), but not bilateral orchiectomy (HR: 1.11; 95% CI, 0.96-1.29; p=0.1), was associated with the risk of experiencing AKI. Our study is limited by its retrospective design.

CONCLUSIONS

ADT is associated with an increased risk of AKI in patients with nonmetastatic PCa. In particular, the administration of GnRH agonists, but not surgical castration, may substantially increase the risk of experiencing AKI. These observations should help provide physicians with better patient selection to reduce the risk of AKI.

PATIENT SUMMARY

The administration of gonadotropin-releasing hormone agonists, but not bilateral orchiectomy, increases the risk of acute kidney injury (AKI) in patients with prostate cancer (PCa). These observations should help provide physicians with better patient selection to reduce the risk of AKI in PCa patients.

Cardiovascular morbidity associated with gonadotropin releasing hormone agonists and an antagonist

BACKGROUND

Androgen deprivation therapy (ADT) is associated with increased cardiovascular morbidity.

OBJECTIVE

To determine whether cardiovascular morbidity differs following initiation of gonadotropin-releasing hormone (GnRH) agonists compared with an antagonist.

DESIGN, SETTING, AND PARTICIPANTS

Pooled data from six phase 3 prospective randomized trials that recruited 2328 men between 2005 and 2012 to compare the efficacy of GnRH agonists against an antagonist. Men recruited had pathologically confirmed prostate cancer, an Eastern Cooperative Oncology Group score <2, a minimum life expectancy of 12 mo, and were naïve to ADT. Men were excluded if they had a prolonged baseline QT/corrected QT interval, other risk factors for heart failure, hypokalemia or a family history of long QT syndrome, or had another cancer diagnosed within 5 yr.

INTERVENTION

Men were randomized to receive a GnRH agonist or an antagonist for either 3-7 mo (n=642) or 12 mo (n=1686). Treatment groups were balanced for common baseline characteristics.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Event analysis was based on death from any cause or cardiac events. Data documenting adverse experiences were classified based on the Medical Dictionary for Regulatory Activities. The following conditions defined a cardiac event: arterial embolic or thrombotic events, hemorrhagic or ischemic cerebrovascular conditions, myocardial infarction, and other ischemic heart disease. Kaplan-Meier curves and log-rank tests were used to compare time to a cardiovascular event or death.

RESULTS AND LIMITATIONS

Among men with preexisting cardiovascular disease, the risk of cardiac events within 1 yr of initiating therapy was significantly lower among men treated with a GnRH antagonist compared with GnRH agonists (hazard ratio: 0.44; 95% confidence interval, 0.26-0.74; p=0.002). Since our analysis is post hoc, our findings should only be interpreted as hypothesis generating.

CONCLUSIONS

GnRH antagonists appear to halve the number of cardiac events experienced by men with preexisting cardiovascular disease during the first year of ADT when compared to GnRH agonists.

Hypothalamic neurohormones and immune responses

The aim of this review is to provide a comprehensive examination of the current literature describing the neural-immune interactions, with emphasis on the most recent findings of the effects of neurohormones on immune system. Particularly, the role of hypothalamic hormones such as Thyrotropin-releasing hormone (TRH), Corticotropin-releasing hormone (CRH) and Gonadotropin-releasing hormone (GnRH). In the past few years, interest has been raised in extrapituitary actions of these neurohormones due to their receptors have been found in many non-pituitary tissues. Also, the receptors are present in immune cells, suggesting an autocrine or paracrine role within the immune system. In general, these neurohormones have been reported to exert immunomodulatory effects on cell proliferation, immune mediators release and cell function. The implications of these findings in understanding the network of hypothalamic neuropeptides and immune system are discussed.

Resection of non-small cell lung cancers reverses tumor-induced gene expression changes in the peripheral immune system

PURPOSE

To characterize the interactions of non-small cell lung cancer (NSCLC) tumors with the immune system at the level of mRNA and microRNA (miRNA) expression and to define expression signatures that characterize the presence of a malignant tumor versus a nonmalignant nodule.

EXPERIMENTAL DESIGN

We have examined the changes of both mRNA and miRNA expression levels in peripheral blood mononuclear cells (PBMC) between paired samples collected from NSCLC patients before and after tumor removal using Illumina gene expression arrays.

RESULTS

We found that malignant tumor removal significantly changes expression of more than 3,000 protein-coding genes, especially genes in pathways associated with suppression of the innate immune response, including natural killer cell signaling and apoptosis-associated ceramide signaling. Binding sites for the ETS domain transcription factors ELK1, ELK4, and SPI1 were enriched in promoter regions of genes upregulated in the presence of a tumor. Additional important regulators included five miRNAs expressed at significantly higher levels before tumor removal. Repressed protein-coding targets of those miRNAs included many transcription factors, several involved in immunologically important pathways. Although there was a significant overlap in the effects of malignant tumors and benign lung nodules on PBMC gene expression, we identified one gene panel which indicates a tumor or nodule presence and a second panel that can distinguish malignant from nonmalignant nodules.

CONCLUSIONS

A tumor presence in the lung influences mRNA and miRNA expression in PBMC and this influence is reversed by tumor removal. These results suggest that PBMC gene expression signatures could be used for lung cancer diagnosis.

Thymic involution: where endocrinology meets immunology

The decline in immune function with aging represents a major clinical challenge in many disease conditions. It is manifest in many parameters but is essentially linked to the adaptive immune responses. The prediction would be that abnormalities in both T and B lymphocytes underlie the loss of cellular and humoral capacity, respectively. Somewhat surprisingly, this is not reflected in numerical losses but more in alterations at the population and single cell levels. There is a major reduction in naïve T cells with a proportional increase in memory cells, and also a generally reduced function of these cells. While bone marrow function reduces with age, the most obvious reason for the T cell defects is the severe atrophy of the thymus. This is closely aligned with puberty, thereby implicating a major aetiological role for sex steroids in both thymus and immune system deterioration with age. Accordingly surgical or chemical castration (utilizing luteinizing hormone-releasing hormone) blocks sex steroids resulting in profound rejuvenation of the immune system.

The role of sex steroids and gonadectomy in the control of thymic involution

A major underlying cause for aging of the immune system is the structural and functional atrophy of the thymus, and associated decline in T cell genesis. This loss of naïve T cells reduces adaptive immunity to new stimuli and precipitates a peripheral bias to memory cells against prior antigens. Whilst multiple mechanisms may contribute to this process, the temporal alliance of thymic decline with puberty has implicated a causative role for sex steroids. Accordingly ablation of sex steroids induces profound thymic rejuvenation. Although the thymus retains some, albeit highly limited, function in healthy adults, this is insufficient for resurrecting the T cell pool following cytoablative treatments such as chemo- and radiation-therapy and AIDS. Increased risk of opportunistic infections and cancer relapse or appearance, are a direct consequence. Temporary sex steroid ablation may thus provide a clinically effective means to regenerate the thymus and immune system in immunodeficiency states.

Regulation of maternal serum and amniotic fluid cytokine profiles in the mouse: Possible roles in the onset of labour

Murine pregnancy is characterised by marked increases in serum cytokine profiles with advancing gestation, but whether these changes reflect concentrations in amniotic fluid is unknown. This study therefore profiled 23 cytokines by fluid-phase multiplex immunoassay of amniotic fluid and serum collected from naturally mated mice during mid- and late pregnancy (days 11 and 18, respectively). The marked increase in serum profile of many cytokines from days 11 to 18 was not reflected in amniotic fluid, wherein most cytokine concentrations were lower on day 18. Serum and amniotic fluid cytokine concentrations were largely inversely related, indicating separate, localised regulatory mechanisms geared towards the maintenance of pregnancy, modulation of immune effector cell function and optimisation of fetal development. We suggest that, while maternal systemic inflammatory priming prepares the mother for birth, the amniotic compartment exhibits a tightly regulated inflammatory quiescence. These findings are discussed in relation to the onset of labour, which ultimately results in the elevated cytokine amniotic levels traditionally associated with the final stages of pregnancy.

Effects of a preovulatory administered depot gonadotrophin-releasing hormone agonist on reproductive hormone levels and pregnancy outcome in gilts

The present study aimed to explore the influence of a preovulatory administered depot gonadotrophin-releasing hormone (GnRH) agonist (GnRHa; Decapeptyl Depot) on the endocrine parameters and pregnancy outcome of gilts (n = 6). A GnRHa-supported preovulatory luteinising hormone (LH) surge was detected in all treated gilts. LH pulses were abolished completely by depot GnRHa on Day 7 and partly on Day 21 of pregnancy. In this treatment group (n = 6) four gilts were pregnant at slaughter on Day 28. In the control group receiving Gonavet, a non-formulated GnRHa (n = 6), all pigs showed LH pulses and were pregnant at slaughter on Day 28 of gestation. Mean progesterone concentrations were elevated in controls during the early luteal phase and were similar for both groups during the implantation period. Mean concentration of unoccupied progesterone receptor was significantly higher in uterine myometrium than in endometrium, but without treatment effects. Peripheral estrone sulfate concentrations showed a similar increase in all pregnant gilts on Days 17 and 18, and remained elevated. In summary, treatment with a depot GnRHa for synchronisation of ovulation alters pulsatile LH secretion during early pregnancy in pigs. In general, this alteration seems not to exert an injurious influence on luteal function and, therefore, on embryo and early fetal development.

The Chemokine SDF-1/CXCL12 Contributes to T Lymphocyte Recruitment in Human Pre-ovulatory Follicles and Coordinates with Lymphocytes to Increase Granulosa Cell Survival and Embryo Quality

We investigated the production and the role of the chemokine stromal cell-derived factor-1 (SDF-1/CXCL12) in pre-ovulatory follicles of women undergoing in vitro fertilization. We detected CXCL12 and its receptor CXCR4 by flow cytometry, western blotting and RT-PCR. We tested cell migration in Transwell experiments. We measured apoptosis using delta psi m-sensitive fluorescent probe DiOC6(3) and we screened apoptosis-related gene expression with macro-arrays. Granulosa cells from follicular aspirates produce CXCL12 that contributes to T lymphocytes recruitment. CXCL12 reduces early apoptosis of granulosa cells. This effect is accompanied by a shift of bcl2/bax ratio, and decreased expression of p53-targeted genes (pig7, pig8, p21, gadd45). Removal of lymphocytes disables CXCL12-mediated anti-apoptotic effect on granulosa cells. Anti-apoptotic activity of CXCL12 is positively correlated to high quality of embryos. In conclusion, CXCL12 is locally produced by luteinizing granulosa cells. It specifically contributes to T lymphocytes recruitment and coordinates with local lymphocytes to increase granulosa cell survival and embryo quality.

Insights into thymic aging and regeneration

The deterioration of the immune system with progressive aging is believed to contribute to morbidity and mortality in elderly humans due to the increased incidence of infection, autoimmunity, and cancer. Dysregulation of T-cell function is thought to play a critical part in these processes. One of the consequences of an aging immune system is the process termed thymic involution, where the thymus undergoes a progressive reduction in size due to profound changes in its anatomy associated with loss of thymic epithelial cells and a decrease in thymopoiesis. This decline in the output of newly developed T cells results in diminished numbers of circulating naive T cells and impaired cell-mediated immunity. A number of theories have been forwarded to explain this 'thymic menopause' including the possible loss of thymic progenitors or epithelial cells, a diminished capacity to rearrange T-cell receptor genes and alterations in the production of growth factors and hormones. Although to date no interventions fully restore thymic function in the aging host, systemic administration of various cytokines and hormones or bone marrow transplantation have resulted in increased thymic activity and T-cell output with age. In this review, we shall examine the current literature on thymic involution and discuss several interventional strategies currently being explored to restore thymic function in elderly subjects.