Association between sex hormones and anti-S/RBD antibody responses to COVID-19 vaccines in healthcare workers.

Healthcare workers (HCWs) are the target population for vaccination against coronavirus disease (COVID-19) as they are at a high risk of exposure and transmission of pathogens to patients. Neutralizing antibodies developed after COVID-19 vaccination decline within few months of vaccination. Several factors, including age and sex, can affect the intensity, efficacy, and duration of immune response to vaccines. However, sex-specific analyses of humoral responses to COVID-19 vaccines are lacking. This study aimed to evaluate sex-based differences in anti-S/RBD (Receptor Binding Domain) responses at three different time points after the second dose of mRNA COVID-19 vaccine in HCWs in relation to age, and to investigate the role of sex hormones as potential markers of response. Anti-S/RBD levels after two doses of the mRNA vaccine were collected from 521 HCWs naïve to COVID-19, working at two Italian Clinical Centers. Multiple regression analysis was applied to evaluate the association between anti-S levels and sex, age, and plasma levels of sex hormones. Significantly higher anti-S/RBD response to the COVID-19 vaccination was found in female HCWs, and a significant and more abrupt decline in response with time was observed in women than that in men. A novel, positive association of testosterone plasma levels and higher anti-S levels in male HCWs was found, suggesting its potential role as sex specific marker in males. In conclusion, understanding the sex-based differences in humoral immune responses to vaccines may potentially improve vaccination strategies and optimize surveillance programs for HCWs.

Sex-oriented perspectives in immunopharmacology.

Several immunopharmacological agents are effective in the treatment of cancer and immune-mediated conditions, with a favorable impact on life expectancy and clinical outcomes for a large number of patients. Nevertheless, response variation and undesirable effects of these drugs represent major issues, and overall efficacy remains unpredictable. Males and females show a distinct difference in immune system responses, with females generally mounting stronger responses to a variety of stimuli. Therefore, exploring sex differences in the efficacy and safety of immunopharmacological agents would strengthen the practice of precision medicine. As a pharmacological target highlight, programmed cell death 1 ligand 1 (PD-L1) is the first functionally characterized ligand of the coinhibitory programmed death receptor 1 (PD-1). The PD-L1/PD-1 crosstalk plays an important role in the immune response and is relevant in cancer, infectious and autoimmune disease. Sex differences in the response to immune checkpoint inhibitors are well documented, with male patients responding better than female patients. Similarly, higher efficacy of and adherence to tumor necrosis factor inhibitors in chronic inflammatory conditions including rheumatoid arthritis and Crohn's disease have been reported in male patients. The pharmacological basis of sex-specific responses to immune system modulating drugs is actively investigated in other settings such as stroke and type 1 diabetes. Advances in therapeutics targeting the endothelium could soon be wielded against autoimmunity and metabolic disorders. Based on the established sexual dimorphism in immune-related pathophysiology and disease presentation, sex-specific immunopharmacological protocols should be integrated into clinical guidelines.

The Role of Sex Differences in Bone Health and Healing.

Fracture healing is a long-term and complex process influenced by a huge variety of factors. Among these, there is a sex/gender disparity. Based on significant differences observed in the outcome of bone healing in males and females, in the present review, we report the main findings, hypotheses and pitfalls that could lead to these differences. In particular, the role of sex hormones and inflammation has been reported to have a role in the observed less efficient bone healing in females in comparison with that observed in males. In addition, estrogen-induced cellular processes such as autophagic cell cycle impairment and molecular signals suppressing cell cycle progression seem also to play a role in female fracture healing delay. In conclusion, it seems conceivable that a complex framework of events could contribute to the female bias in bone healing, and we suggest that a reappraisal of the compelling factors could contribute to the mitigation of sex/gender disparity and improve bone healing outcomes.

Human Monocyte-Derived Dendritic Cells Are the Pharmacological Target of the Immunosuppressant Flavonoid Silibinin.

Silibinin, a natural polyphenolic flavonoid, is known to possess anti-inflammatory, anticancer, antioxidant, and immunomodulatory properties. However, the effects of Silibinin on the maturation and immunostimulatory functions of human dendritic cells (DC) remain to be elucidated. In this study, we have attempted to ascertain whether Silibinin influences the maturation, cytokine production, and antigen-presenting capacity of human monocyte-derived DC. We show that Silibinin significantly suppresses the upregulation of costimulatory and MHC molecules in LPS-stimulated mature DC and inhibits lipopolysaccharide (LPS)-induced interleukin (IL)-12, IL-23, and TNF-α production. Furthermore, Silibinin impairs the proliferation response of the allogenic memory CD4 T lymphocytes elicited by LPS-matured DC and their Th1/Th17 profile. These findings demonstrate that Silibinin displays immunosuppressive activity by inhibiting the maturation and activation of human DC and support its potential application of adjuvant therapy in the treatment of autoimmune diseases.

Anti-Inflammatory Effects of 1,25(OH)2D/Calcitriol in T Cell Immunity: Does Sex Make a Difference?

Hypovitaminosis D is involved in various inflammatory, infectious and autoimmune diseases such as rheumatoid arthritis and multiple sclerosis. Moreover, the active form of vitamin D, calcitriol, has been shown to modulate the immune response, playing an anti-inflammatory effect. However little is known about the mechanisms underlying this anti-inflammatory effect and the potential sex differences of calcitriol immune regulation. Hence, the aim of this study was to investigate whether calcitriol could act differently in modulating T cell immunity of age-matched male and female healthy donors. We analyzed the effects of calcitriol in T lymphocytes from healthy women and men on the expression levels of the vitamin D receptor (VDR) and pro- and anti-inflammatory cytokine production. We showed that a treatment with calcitriol induced a significant increase in the VDR expression levels of activated T lymphocytes from male and female healthy subjects. Moreover, we found that calcitriol significantly reduced the expression level of pro-inflammatory cytokines IL-17, INF-γ and TNF-α in the T lymphocytes of both sexes. Notably, we observed that calcitriol induced a significant increase in the expression level of anti-inflammatory cytokine IL-10 only in the T lymphocytes from female healthy donors. In conclusion, our study provides new insights regarding the sex-specific anti-inflammatory role of calcitriol in T cell immunity.

The Natural Estrogen Receptor Beta Agonist Silibinin as a Promising Therapeutic Tool in Diffuse Large B-cell Lymphoma.

BACKGROUND/AIM: About 40% of patients with diffuse large cell lymphoma (DLBCL) still have a poor prognosis. Additionally, DLBCL patients treated with doxorubicin are at risk of cardiac failure. Growing evidence suggests an antitumor and cardioprotective activity exerted by estrogen via its binding to estrogen receptor (ER) ß. The aim of this study was to evaluate the anticancer activity of the phytoestrogen silibinin, an ERß selective agonist, on DLBCL growth, and its potential cardioprotective effect. MATERIALS AND METHODS: DLBCL cell lines SUDHL-8, SUDHL-6, and RIVA were used. The anti-tumor activity of silibinin was also evaluated in vivo in NOD/SCID/IL2Rg-/- (NSG) xenografted mice. AC16 human ventricular cardiomyocytes were used to investigate the cardioprotective effects of silibinin. RESULTS: In vitro silibinin induced apoptosis and autophagy, and blocked tumor cell proliferation, also protecting AC16 cardiomyocytes from doxorubicin-induced toxicity. In vivo silibinin induced cell death and autophagy, and reduced tumor volume. CONCLUSION: Silibinin represents a promising therapeutic tool.

Predicting respiratory failure in patients infected by SARS-CoV-2 by admission sex-specific biomarkers.

BACKGROUND: Several biomarkers have been identified to predict the outcome of COVID-19 severity, but few data are available regarding sex differences in their predictive role. Aim of this study was to identify sex-specific biomarkers of severity and progression of acute respiratory distress syndrome (ARDS) in COVID-19. METHODS: Plasma levels of sex hormones (testosterone and 17ß-estradiol), sex-hormone dependent circulating molecules (ACE2 and Angiotensin1-7) and other known biomarkers for COVID-19 severity were measured in male and female COVID-19 patients at admission to hospital. The association of plasma biomarker levels with ARDS severity at admission and with the occurrence of respiratory deterioration during hospitalization was analysed in aggregated and sex disaggregated form. RESULTS: Our data show that some biomarkers could be predictive both for males and female patients and others only for one sex. Angiotensin1-7 plasma levels and neutrophil count predicted the outcome of ARDS only in females, whereas testosterone plasma levels and lymphocytes counts only in males. CONCLUSIONS: Sex is a biological variable affecting the choice of the correct biomarker that might predict worsening of COVID-19 to severe respiratory failure. The definition of sex specific biomarkers can be useful to alert patients to be safely discharged versus those who need respiratory monitoring.

Sex-tailored pharmacology and COVID-19: Next steps towards appropriateness and health equity.

Making gender bias visible allows to fill the gaps in knowledge and understand health records and risks of women and men. The coronavirus disease 2019 (COVID-19) pandemic has shown a clear gender difference in health outcomes. The more severe symptoms and higher mortality in men as compared to women are likely due to sex and age differences in immune responses. Age-associated decline in sex steroid hormone levels may mediate proinflammatory reactions in older adults, thereby increasing their risk of adverse outcomes, whereas sex hormones and/or sex hormone receptor modulators may attenuate the inflammatory response and provide benefit to COVID-19 patients. While multiple pharmacological options including anticoagulants, glucocorticoids, antivirals, anti-inflammatory agents and traditional Chinese medicine preparations have been tested to treat COVID-19 patients with varied levels of evidence in terms of efficacy and safety, information on sex-targeted treatment strategies is currently limited. Women may have more benefit from COVID-19 vaccines than men, despite the occurrence of more frequent adverse effects, and long-term safety data with newly developed vectors are eagerly awaited. The prevalent inclusion of men in randomized clinical trials (RCTs) with subsequent extrapolation of results to women needs to be addressed, as reinforcing sex-neutral claims into COVID-19 research may insidiously lead to increased inequities in health care. The huge worldwide effort with over 3000 ongoing RCTs of pharmacological agents should focus on improving knowledge on sex, gender and age as pillars of individual variation in drug responses and enforce appropriateness.

Chronic Isolation Stress Affects Central Neuroendocrine Signaling Leading to a Metabolically Active Microenvironment in a Mouse Model of Breast Cancer.

Social isolation is a powerful stressor capable of affecting brain plasticity and function. In the case of breast cancer, previous data indicate that stressful experiences may contribute to a worse prognosis, activating neuroendocrine and metabolism pathways, although the mechanisms underlying these effects are still poorly understood. In this study, we tested the hypothesis that chronic isolation stress (IS) may boost hypothalamic-pituitary-adrenal (HPA) axis activity, leading to changes in the hypothalamic expression of genes modulating both mood and metabolism in an animal model of breast cancer. This centrally activated signaling cascade would, in turn, affect the mammary gland microenvironment specifically targeting fat metabolism, leading to accelerated tumor onset. MMTVNeuTg female mice (a model of breast cancer developing mammary hyperplasia at 5 months of age) were either group-housed (GH) or subjected to IS from weaning until 5 months of age. At this time, half of these subjects underwent acute restraint stress to assess corticosterone (CORT) levels, while the remaining subjects were characterized for their emotional profile in the forced swimming and saccharin preference tests. At the end of the procedures, all the mice were sacrificed to assess hypothalamic expression levels of Brain-derived neurotrophic factor (Bdnf), Neuropeptide Y (NpY), Agouti-Related Peptide (AgRP), and Serum/Glucocorticoid-Regulated Protein Kinase 1 (SgK1). Leptin and adiponectin expression levels, as well as the presence of brown adipose tissue (BAT), were assessed in mammary fat pads. The IS mice showed higher CORT levels following acute stress and decreased expression of NpY, AgRP, and SgK1, associated with greater behavioral despair in the forced swimming test. Furthermore, they were characterized by increased consumption of saccharin in a preference test, suggesting an enhanced hedonic profile. The IS mice also showed an earlier onset of breast lumps (assessed by palpation) accompanied by elevated levels of adipokines (leptin and adiponectin) and BAT in the mammary fat pads. Overall, these data point to IS as a pervasive stressor that is able to specifically target neuronal circuits, mastered by the hypothalamus, modulating mood, stress reactivity and energy homeostasis. The activation of such IS-driven machinery may hold main implications for the onset and maintenance of pro-tumorigenic environments.

The Sex-Related Interplay between TME and Cancer: On the Critical Role of Estrogen, MicroRNAs and Autophagy.

The interplay between cancer cells and the tumor microenvironment (TME) has a fundamental role in tumor progression and response to therapy. The plethora of components constituting the TME, such as stroma, fibroblasts, endothelial and immune cells, as well as macromolecules, e.g., hormones and cytokines, and epigenetic factors, such as microRNAs, can modulate the survival or death of cancer cells. Actually, the TME can stimulate the genetically regulated programs that the cell puts in place under stress: apoptosis or, of interest here, autophagy. However, the implication of autophagy in tumor growth appears still undefined. Autophagy mainly represents a cyto-protective mechanism that allows cell survival but, in certain circumstances, also leads to the blocking of cell cycle progression, possibly leading to cell death. Since significant sex/gender differences in the incidence, progression and response to cancer therapy have been widely described in the literature, in this review, we analyzed the roles played by key components of the TME, e.g., estrogen and microRNAs, on autophagy regulation from a sex/gender-based perspective. We focused our attention on four paradigmatic and different forms of cancers-colon cancer, melanoma, lymphoma, and lung cancer-concluding that sex-specific differences may exert a significant impact on TME/cancer interaction and, thus, tumor growth.

Synergy Between Vitamin D and Sex Hormones in Respiratory Functionality of Patients Affected by COVID-19.

The outcome of COVID-19 appears to be influenced by vitamin D status of population. Although epidemiological data indicate that COVID-19 produces more severe symptoms and higher mortality in elderly in comparison to young patients and in men in comparison to women to date sex and age differences in vitamin D status in infected patients have not been evaluated yet. In this study we evaluated the levels of circulating 25(OH)D in patients hospitalized for COVID-19 divided accordingly to their sex and age. We also correlated 25(OH)D levels with patient's respiratory status (i.e., PaO2/FiO2 ratio) and with sex hormones plasma levels to analyze the potential relationship of these parameters. We found no significant differences in plasma levels of 25(OH)D between pre- and post-menopausal female patients and age matched male patients. Interestingly, the 25(OH)D plasma levels positively correlated to PaO2/FiO2 ratio only in young patients, regardless of their sex. We also found a significantly positive correlation between 17ß-estradiol and 25(OH)D in elderly women and between testosterone and 25(OH)D in elderly men, supporting the role of sex hormones in maintaining 25(OH)D levels. In conclusion, we suggest that a synergy between vitamin D and sex hormones could contribute to the age-related outcome of COVID-19.

A Sex Perspective in Neurodegenerative Diseases: microRNAs as Possible Peripheral Biomarkers.

Sex is a significant variable in the prevalence and incidence of neurological disorders. Sex differences exist in neurodegenerative disorders (NDs), where sex dimorphisms play important roles in the development and progression of Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. In the last few years, some sex specific biomarkers for the identification of NDs have been described and recent studies have suggested that microRNA (miRNA) could be included among these, as influenced by the hormonal and genetic background. Failing to consider the possible differences between males and females in miRNA evaluation could introduce a sex bias in studies by not considering some of these sex-related biomarkers. In this review, we recapitulate what is known about the sex-specific differences in peripheral miRNA levels in neurodegenerative diseases. Several studies have reported sex-linked disparities, and from the literature analysis miR-206 particularly has been shown to have a sex-specific involvement. Hopefully, in the near future, patient stratification will provide important additional clues in diagnosis, prognosis, and tailoring of the best therapeutic approaches for each patient. Sex-specific biomarkers, such as miRNAs, could represent a useful tool for characterizing subgroups of patients.

The role of vitamin D in autoimmune diseases: could sex make the difference?

Over the last decades, a central role for vitamin D in immune modulation has been well established. The active form of vitamin D, i.e., 1,25-dihydroxyvitamin D, through the interaction with vitamin D receptor, exerts different activities on the innate and adaptive immune system, among which suppression of inflammation and promotion of tolerogenic responses. Vitamin D insufficiency has been linked to autoimmune disorders that commonly display significant differences between females and males due to genetic, epigenetic, hormonal, and environmental factors. Notably, a number of studies recently showed a cross-talk between vitamin D and the sex hormone estrogen. Estrogen-mediated effects on immune response may favor a Th1 profile or a Th2 profile, depending on hormone concentration. Thus, estrogen-mediated effects appear to be variable on autoimmunity depending on its concentration but also on the pathogenic mechanisms underlying the different autoimmune diseases (i.e., Th1- or Th2-mediated diseases). Notably, estrogen has been demonstrated to enhance vitamin D function favoring its accumulation, and increasing the expression of vitamin D receptor, thus resulting in a more potent anti-inflammatory response in females than males. On the other hand, vitamin D has been shown to downregulate in immune cells the expression of aromatase, which converts testosterone to estrogen, leading to a decrease in estrogen level. Overall, available data allow us to hypothesize a higher protective effect of vitamin D-based therapeutic approaches in women, at least in fertile age, than in men. Future studies are needed to expand current knowledge on the immunomodulatory role of vitamin D in a sex and gender perspective, paving the way to a more personalized therapeutic approach in autoimmune diseases.

Stress and coping in women with breast cancer:unravelling the mechanisms to improve resilience.

Breast cancer diagnosis, surgery, adjuvant therapies and survivorship can all be extremely stressful. In women, concerns about body image are common as a result of the disease and can affect interpersonal relationships, possibly leading to social isolation, increasing the likelihood for mood disorders. This is particularly relevant as women are at greater risk to develop anxiety and depressive symptoms in response to highly stressful situations. Here we address the mechanisms and the pathways activated as a result of stress and contributing to changes in the pathophysiology of breast cancer, as well as the potential of stress management factors and interventions in buffering the deleterious effects of chronic stress in a gender perspective. An improved understanding of the biological mechanisms linking stress-management resources to health-relevant biological processes in breast cancer patients could reveal novel therapeutic targets and help clarifying which psychosocial interventions can improve cancer outcomes, ultimately offering a unique opportunity to improve contemporary cancer treatments.

A Role for Estrogen Receptor alpha36 in Cancer Progression.

Estrogen receptor α (ERα) functions as a ligand dependent transcription factor that directly binds specific estrogen responsive elements, thus regulating the transcription of estrogen sensitive genes. ERα has also been shown to be associated with the plasma membrane (membrane associated ERα, mERα), concentrated in lipid rafts, plasma membrane microdomains with a distinct lipid composition, where it transduces membrane-initiated estrogen-dependent activation of the mitogen-activated protein (MAP) kinase signaling pathway. Two isoforms of ERα have been described: the "traditional" ERα66 (66 kDa) and a lower molecular weight variant: the ERα46 (46 kDa). More recently, a novel ERα variant with a molecular mass of 36 kDa (ERα36) has been discovered. Notably, ERα36 has been found expressed in different human tumor cells, including both ER- positive and ER- negative breast cancer cells. Estrogen signaling at the cell membrane via ERα36 appears as capable of activating multiple pathways of importance for cancer aggressiveness and metastatic potential. The presence of serum autoantibodies reacting with mERα (anti-ERα Abs) in a large percentage of patients with breast cancer has recently been reported by our group. These anti-ERα Abs seem to act as estrogen agonists rapidly triggering MAP kinase pathway activation thus inducing tumor cell proliferation and overcoming cell resistance to anti-estrogen drug tamoxifen. In this review, we describe the involvement of ERα36 in different tumors. We also report the potential pathogenetic activity of anti-ERα Abs and their implication in drug resistance.