Immunomodulatory effects of testosterone evaluated in all-trans retinoic acid differentiated HL-60 cells, granulocytes, and monocytes

Inflammation dynamically regulates steroid hormone metabolism and action within macrophages in rheumatoid arthritis

RATIONALE

In inflammatory diseases such as rheumatoid arthritis (RA), steroid metabolism is a central component mediating the actions of immuno-modulatory glucocorticoids and sex steroids. However, the regulation and function of cellular steroid metabolism within key leukocyte populations such as macrophages remain poorly defined. In this study, the inflammatory regulation of global steroid metabolism was assessed in RA macrophages.

METHODS

Bulk RNA-seq data from RA synovial macrophages was used to assess transcripts encoding key enzymes in steroid metabolism and signalling. Changes in metabolism were assessed in synovial fluids, correlated to measures of disease activity and functionally validated in primary macrophage cultures.

RESULTS

RNA-seq revealed a unique pattern of differentially expressed genes, including changes in genes encoding the enzymes 11β-HSD1, SRD5A1, AKR1C2 and AKR1C3. These correlated with disease activity, favouring increased glucocorticoid and androgen levels. Synovial fluid 11β-HSD1 activity correlated with local inflammatory mediators (TNFα, IL-6, IL-17), whilst 11β-HSD1, SRD5A1 and AKR1C3 activity correlated with systemic measures of disease and patient pain (ESR, DAS28 ESR, global disease activity). Changes in enzyme activity were evident in inflammatory activated macrophages in vitro and revealed a novel androgen activating role for 11β-HSD1. Together, increased glucocorticoids and androgens were able to suppress inflammation in macrophages and fibroblast-like-synoviocytes.

CONCLUSIONS

This study underscores the significant increase in androgen and glucocorticoid activation within inflammatory polarized macrophages of the synovium, contributing to local suppression of inflammation. The diminished profile of inactive steroid precursors in postmenopausal women may contribute to disturbances in this process, leading to increased disease incidence and severity.

Ex Vivo 13C-Metabolic Flux Analysis of Porcine Circulating Immune Cells Reveals Cell Type-Specific Metabolic Patterns and Sex Differences in the Pentose Phosphate Pathway

In general, females present with stronger immune responses than males, but scarce data are available on sex-specific differences in immunometabolism. In this study, we characterized porcine peripheral blood mononuclear cell (PBMC) and granulocyte energy metabolism using a Bayesian 13C-metabolic flux analysis, which allowed precise determination of the glycolytic, pentose phosphate pathway (PPP), and tricarboxylic acid cycle (TCA) fluxes, together with an assessment of the superoxide anion radical (O2•-) production and mitochondrial O2 consumption. A principal component analysis allowed for identifying the cell type-specific patterns of metabolic plasticity. PBMCs displayed higher TCA cycle activity, especially glutamine-derived aspartate biosynthesis, which was directly related to mitochondrial respiratory activity and inversely related to O2•- production. In contrast, the granulocytes mainly utilized glucose via glycolysis, which was coupled to oxidative PPP utilization and O2•- production rates. The granulocytes of the males had higher oxidative PPP fluxes compared to the females, while the PBMCs of the females displayed higher non-oxidative PPP fluxes compared to the males associated with the T helper cell (CD3+CD4+) subpopulation of PBMCs. The observed sex-specific differences were not directly attributable to sex steroid plasma levels, but we detected an inverse correlation between testosterone and aldosterone plasma levels and showed that aldosterone levels were related with non-oxidative PPP fluxes of both cell types.

Forsythiaside A prevents zymosan A-induced cell migration in neutrophil-differentiated HL-60 cells via PD-1/PD-L1 pathway

Neutrophils, which account for more than 80% of leukocyte, play an important role in resolution of inflammation. Immune checkpoint molecules could be potential biomarkers in immunosuppression. Forsythiaside A (FTA), a main constituent of Forsythia suspensa (Thunb.) Vahl, provides a very significant anti-inflammatory activity. Here we defined the immunological mechanisms of FTA by taking programmed cell death-1 (PD-1)/programmed cell death-Ligand 1 (PD-L1) pathway into consideration. FTA could inhibited cell migration in HL-60-derived neutrophils in vitro, and this action appeared to be mediated via PD-1/PD-L1 depended JNK and p38 MAPK pathways. In vivo, FTA prevented PD-L1⁺ neutrophils infiltration and reduced the levels of tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1) and interferon-gamma (IFN-γ) after zymosan A-induced peritonitis. PD-1/PD-L1 inhibitor could abolish the suppression of FTA. The expression of inflammatory cytokines and chemokines were positively correlated with PD-L1. Molecular docking showed that FTA could bind to PD-L1. Taken together, FTA might prevent neutrophils infiltration to exert inflammation resolution through PD-1/PD-L1 pathway.

Sex—the most underappreciated variable in research: insights from helminth-infected hosts

The sex of a host affects the intensity, prevalence, and severity of helminth infection. In many cases, one sex has been found to be more susceptible than the other, with the prevalence and intensity of helminth infections being generally higher among male than female hosts; however, many exceptions exist. This observed sex bias in parasitism results primarily from ecological, behavioural, and physiological differences between males and females. Complex interactions between these influences modulate the risk of infection. Indeed, an interplay among sex hormones, sex chromosomes, the microbiome and the immune system significantly contributes to the generation of sex bias among helminth-infected hosts. However, sex hormones not only can modulate the course of infection but also can be exploited by the parasites, and helminths appear to have developed molecules and pathways for this purpose. Furthermore, host sex may influence the efficacy of anti-helminth vaccines; however, although little data exist regarding this sex-dependent efficacy, host sex is known to influence the response to vaccines. Despite its importance, host sex is frequently overlooked in parasitological studies. This review focuses on the key contributors to sex bias in the case of helminth infection. The precise nature of the mechanisms/factors determining these sex-specific differences generally remains largely unknown, and this represents an obstacle in the development of control methods. There is an urgent need to identify any protective elements that could be targeted in future therapies to provide optimal disease management with regard to host sex. Hence, more research is needed into the impact of host sex on immunity and protection.

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

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

The extent to which immunity, apoptosis and detoxification gene expression interact with 17 alpha-methyltestosterone

Innate immunity is the first line of defence against invasion by foreign pathogens. One widely used synthetic androgen for the production of all-male fish, particularly commercially valuable Nile tilapia, Oreochromis niloticus, is 17 alpha-methyltestosterone (MT). The present study investigates the effect of MT on innate immunity, cellular apoptosis and detoxification and the mortality rate, during and after the feeding of fry with 0-, 40-and 60-mg MT/kg. Expression analysis was completed on interleukin 1 beta (il1β), interleukin 8 (il8), tumour necrosis factor alpha (tnfα), CXC2- and CC-chemokines, interferon (ifn), myxovirus resistance (mx), toll-like receptor 7 (tlr7), immunoglobulin M heavy chain (IgM heavy chain), vitellogenin (vtg), cellular apoptosis susceptibility (cas) and glutathione S-transferase α1 (gstα1). Expression analysis revealed that MT had a significant impact on these genes, and this impact varied from induction to repression during and after the treatment. Linear regression analysis showed a significant association between the majority of the tested gene transcript levels and mortality rates on the 7^th and 21^st days of hormonal treatment and 2 weeks following hormonal cessation. The results are thoroughly discussed in this article. This is the first report concerning the hazardous effect of MT on a series of genes involved in immunity, apoptosis and detoxification in the Nile tilapia fry.

Testosterone therapy and prostate cancer

The use of exogenous testosterone to treat hypogonadism in the men with a history of prostate cancer (CaP) remains controversial due to fears of cancer recurrence or progression. Due to the detrimental impact of hypogonadism on patient quality of life, recent work has examined the safety of testosterone therapy (TTh) in men with a history of CaP. In this review, we evaluate the literature with regards to the safety of TTh in men with a history of CaP. TTh results in improvements in quality of life with little evidence of biochemical recurrence or progression in men with a history of CaP, or de novo cancer in unaffected men. An insufficient amount of evidence is currently available to truly demonstrate the safe use of TTh in men with low risk CaP. In men with high-risk cancer, more limited data suggest that TTh may be safe, but these findings remain inconclusive. Despite the historic avoidance of TTh in men with a history of CaP, the existing body of evidence largely supports the safe and effective use of testosterone in these men, although additional study is needed before unequivocal safety can be demonstrated.

Reactive oxygen species: players in the cardiovascular effects of testosterone

Androgens are essential for the development and maintenance of male reproductive tissues and sexual function and for overall health and well being. Testosterone, the predominant and most important androgen, not only affects the male reproductive system, but also influences the activity of many other organs. In the cardiovascular system, the actions of testosterone are still controversial, its effects ranging from protective to deleterious. While early studies showed that testosterone replacement therapy exerted beneficial effects on cardiovascular disease, some recent safety studies point to a positive association between endogenous and supraphysiological levels of androgens/testosterone and cardiovascular disease risk. Among the possible mechanisms involved in the actions of testosterone on the cardiovascular system, indirect actions (changes in the lipid profile, insulin sensitivity, and hemostatic mechanisms, modulation of the sympathetic nervous system and renin-angiotensin-aldosterone system), as well as direct actions (modulatory effects on proinflammatory enzymes, on the generation of reactive oxygen species, nitric oxide bioavailability, and on vasoconstrictor signaling pathways) have been reported. This mini-review focuses on evidence indicating that testosterone has prooxidative actions that may contribute to its deleterious actions in the cardiovascular system. The controversial effects of testosterone on ROS generation and oxidant status, both prooxidant and antioxidant, in the cardiovascular system and in cells and tissues of other systems are reviewed.

Regulation of neutrophil phagocytosis of Escherichia coli by antipsychotic drugs

Antipsychotic drugs (APDs) have been used to ease the symptoms of schizophrenia. APDs have recently been reported to regulate the immune response. Our previous studies revealed that the atypical APDs risperidone and clozapine and the typical APD haloperidol can inhibit the phagocytic ability of macrophages. Our research next determined the effects of APDs on the phagocytic ability of neutrophils, which are the most abundant type of white blood cells in mammals. Here we provide evidence that clozapine and haloperidol can induce increased phagocytic uptake of Escherichia coli by differentiated HL-60 cells and by purified human neutrophils. Furthermore, clozapine and haloperidol can increase the myeloperoxidase activity and IL-8 production in neutrophils. Our results also show that clozapine can inhibit E. coli survival within differentiated HL-60 cells. Furthermore, clozapine and haloperidol are shown to enhance cell surface Mac-1 expression and the activated AKT signaling pathway in purified neutrophils exposed to E. coli. These results indicate that clozapine and haloperidol can increase the phagocytic ability of neutrophils by increasing AKT activation when cells are exposed to bacteria.