Modulation of the inflammatory response by estrogens with focus on the endothelium and its interactions with leukocytes

Sex-related differences in systemic inflammatory response and outcomes after cardiac surgery and cardiopulmonary bypass

OBJECTIVES

Differences in inflammatory responses between men and women may contribute to sex disparities in cardiac surgery outcomes. We investigated how sex differences influence systemic inflammatory response syndrome (SIRS) and adverse outcomes after cardiac surgery.

METHODS

A single-centre retrospective cohort study of patients undergoing cardiac surgery from 2018 to 2020 was performed. SIRS was defined as per the American College of Chest Physicians/Society of Critical Care Medicine. Predictors of SIRS and composite adverse outcomes (death, transient ischaemic attack/stroke, renal therapy, bleeding, postcardiotomy mechanical circulatory support, prolonged Intensive Care Unit stay) were evaluated using multivariable logistic regression. Mediation effects of SIRS were assessed using structural equation modelling.

RESULTS

The cohort included 1005 patients, of whom 299 (29.8%) were women. SIRS occurred in 28.1% of patients, and 12.7% experienced the composite end point. Female sex was significantly associated with SIRS (odds ratio 1.56; 95% confidence interval 1.12-2.18, P = 0.009) and the composite outcome (odds ratio 1.72; 95% confidence interval 1.10-2.69, P = 0.017). Baseline left ventricular dysfunction and intraoperative hyperlactatemia were additional common predictors. SIRS mediated 50.8% of the effect of female sex, 17.0% of left ventricular dysfunction and 30.9% of intraoperative hyperlactatemia on the composite outcome.

CONCLUSIONS

Female sex is independently associated with postoperative SIRS and poorer outcomes. Systemic inflammation, preoperative anaemia and procedural hyperlactatemia are potentially modifiable factors in the mechanisms through which female sex appears to worsen outcome after cardiac surgery.

Sex-dependent modulation of caerulein-induced acute pancreatitis in C57BL/6J mice

Acute pancreatitis (AP) is a life-threatening condition, with a higher mortality rate in men than women and in which estrogens might play a protective role. This study aimed to investigate sex-dependent differences in a mouse model of caerulein-induced AP. Thirty-six C57BL/6J mice (19 females and 17 males) were treated intraperitoneally with phosphate-buffered saline or caerulein, and sacrificed 12 hours, 2 days, or 7 days after the last injection. Blood was collected for amylase, lipase, and glucose determination. Severity and extent of inflammation, apoptosis, and acinar to ductal metaplasia (ADM) in pancreatic tissue were scored histologically and total macrophages, major histocompatibility complex (MHC)-II+ cells, M2 macrophages, T and B cells, neutrophils, apoptosis, and ADM were marked immunohistochemically and quantified by digital image analysis. Serum amylase had a peak at 12 hours, without differences between the sexes. In females, pancreatitis reached a peak at 12 hours with a fast recovery while, in males, the peak was delayed to day 2 with residual apoptosis still present. Macrophages were the main inflammatory cell population, followed by T cells, B cells and neutrophils, without differences between sexes. In males, CD206+ cells and apoptosis were higher at both days 2 and 7, and cytokeratin-19+ (CK19+) ADM was higher at day 7 compared with females. The results of this study revealed a faster onset and resolution of caerulein-induced AP in female mice compared with male mice, supporting a sex-dependent modulation of acute pancreatitis.

Reduced estrogen signaling contributes to bone loss and cardiac dysfunction in interleukin-10 knockout mice

Characterization of the interleukin (IL)-10 knockout (KO) mouse with chronic gut inflammation, cardiovascular dysfunction, and bone loss suggests a critical role for this cytokine in interorgan communication within the gut, bone, and cardiovascular axis. We sought to understand the role of IL-10 in the cross-talk between these systems. Six-week-old IL-10 KO mice and their wild type (WT) counterparts were maintained on a standard rodent diet for 3 or 6 months. Gene expression of proinflammatory markers and Fgf23, serum 17β-estradiol (E2), and cardiac protein expression were assessed. Ileal Il17a and Tnf mRNA increased while Il6 mRNA increased in the bone and heart by at least 2-fold in IL-10 KO mice. Bone Dmp1 and Phex mRNA were repressed at 6 months in IL-10 KO mice, resulting in increased Fgf23 mRNA (~4-fold) that contributed to increased fibrosis. In the IL-10 KO mice, gut bacterial β-glucuronidase activity and ovarian Cyp19a1 mRNA were lower (p < 0.05), consistent with reduced serum E2 and reduced cardiac pNOS3 (Ser1119 ) in these mice. Treatment of ileal lymphocytes with E2 reduced gut inflammation in WT but not IL-10 KO mice. In conclusion, our data suggest that diminished estrogen and defective bone mineralization increased FGF23 which contributed to cardiac fibrosis in the IL-10 KO mouse.

Aging modulates homeostatic leukocyte trafficking to the peritoneal cavity in a sex-specific manner

Aging is associated with exacerbated systemic inflammation (inflammaging) and the progressive loss of immune system function (immunosenescence). Leukocyte migration is necessary for effective immunity; however, dysregulated trafficking of leukocytes into tissue contributes to inflammaging and the development of age-related inflammatory diseases. Aging modulates leukocyte trafficking under inflammatory conditions; however, whether aging modulates leukocyte trafficking under homeostatic conditions remains to be elucidated. Although immune responses are evidently sexually dimorphic, limited studies have investigated the effect of sex on age-related changes to leukocyte trafficking processes. Here, we investigated age-related and sex-specific changes to the leukocyte populations within the peritoneal cavity of young (3-mo), middle-aged (18-mo) and old (21-mo) male and female wild-type mice in the steady state. We found an age-related increase in the number of leukocytes within the peritoneal cavity of female mice, predominantly B cells, which may reflect increased trafficking through this tissue with age. This was accompanied by an increased inflammatory environment within the aged cavity, including increased levels of chemoattractants, including B cell chemoattractants CXCL13 and CCL21, soluble adhesion molecules, and proinflammatory cytokines, which was more pronounced in aged female mice. Intravital microscopy techniques revealed altered vascular structure and increased vascular permeability within the peritoneal membrane of aged female mice, which may support increased leukocyte trafficking to the cavity with age. Together, these data indicate that aging affects homeostatic leukocyte trafficking processes in a sex-specific fashion.

Endothelial ERα promotes glucose tolerance by enhancing endothelial insulin transport to skeletal muscle

The estrogen receptor (ER) designated ERα has actions in many cell and tissue types that impact glucose homeostasis. It is unknown if these include mechanisms in endothelial cells, which have the potential to influence relative obesity, and processes in adipose tissue and skeletal muscle that impact glucose control. Here we show that independent of impact on events in adipose tissue, endothelial ERα promotes glucose tolerance by enhancing endothelial insulin transport to skeletal muscle. Endothelial ERα-deficient male mice are glucose intolerant and insulin resistant, and in females the antidiabetogenic actions of estradiol (E2) are absent. The glucose dysregulation is due to impaired skeletal muscle glucose disposal that results from attenuated muscle insulin delivery. Endothelial ERα activation stimulates insulin transcytosis by skeletal muscle microvascular endothelial cells. Mechanistically this involves nuclear ERα-dependent upregulation of vesicular trafficking regulator sorting nexin 5 (SNX5) expression, and PI3 kinase activation that drives plasma membrane recruitment of SNX5. Thus, coupled nuclear and non-nuclear actions of ERα promote endothelial insulin transport to skeletal muscle to foster normal glucose homeostasis.

The effects of dietary linoleic acid on reducing serum cholesterol and atherosclerosis development are nullified by a high-cholesterol diet in male and female apoE-deficient mice

Linoleic acid (LA) has a two-sided effect with regard to serum cholesterol-lowering and pro-inflammation, although whether this fatty acid reduces serum cholesterol and the development of atherosclerosis under high-cholesterol conditions has yet to be ascertained. In this study, we examine the effects of dietary LA on reducing serum cholesterol and atherosclerosis development under high-cholesterol conditions. Male and female apoE-deficient (ApoE^-/-) mice were fed AIN-76-based diets containing 10% SFA and 0·04 % cholesterol, 10% LA and 0·04% low cholesterol (LALC), or 10% LA and 0·1% high cholesterol (LAHC) for 9 weeks. The results revealed significant reduction in serum cholesterol levels and aortic lesions with increasing levels of pro-inflammatory biomarkers (urinary isoprostane and aortic MCP-1 mRNA) in male and female LALC groups compared with those in the SFA groups (P < 0·05). Furthermore, whereas there were significant increases in the serum cholesterol levels and aortic lesions (P < 0·05), there was no difference in aortic MCP-1 mRNA levels in male and female LAHC groups compared with those in the LALC groups. A high-dietary intake of cholesterol eliminated the serum cholesterol-lowering activity of LA but had no significant effect on aortic inflammation in either male or female ApoE^-/- mice. The inhibitory effect of LA on arteriosclerosis is cancelled by a high-cholesterol diet due to a direct increase in serum cholesterol levels. Accordingly, serum cholesterol levels might represent a more prominent pathogenic factor than aortic inflammation in promoting the development of atherosclerosis.

Influence of Sex and Muscarinic Activity on Memory Retrieval in Mouse Model of Traumatic Brain Injury

Traumatic brain injury (TBI) is a serious global risk factor leading to the onset of cognitive impairment and neurodegenerative diseases. Cognitive and memory impairment following a TBI is associated with the dysregulation of cholinergic neurotransmission in the brains of subjects. The extent of memory impairment following a TBI is linked with the sex of the subject. This study aimed to identify the sex-dimorphic role of muscarinic cholinergic modulation in neurological functioning and episodic memory retrieval in a mouse model of TBI. Balb/c mice were divided into four groups of males and four groups of females (i.e., Sham, TBI, TBI + Scopolamine 1 mg/kg, and TBI + Donepezil 1 mg/kg). After training with the Morris water maze test and fear conditioning, all groups were subjected to brain injury (7.84 × 10^-5 J impact force) except for the Sham mice. Following brain injury, scopolamine or donepezil was administered to the respective groups for 5 days. Acute scopolamine immediately after brain trauma showed a neuroprotective effect in the males only, while subchronic donepezil significantly impaired neurological functioning in both sexes. Subchronic scopolamine and donepezil treatment reversed the TBI-induced retrograde amnesia for spatial memory in male mice. Contextual fear memory retrieval was not affected by the TBI and treatments in both sexes. Thus, we concluded that the sex-dimorphic response of the muscarinic receptors in TBI-induced memory impairment depends on the type of memory. This study highlights the potential for therapeutic modalities in TBI subjects.

Effects of biological sex and pregnancy in experimental autoimmune encephalomyelitis: It's complicated

Experimental autoimmune encephalomyelitis (EAE) can be induced in many animal strains by inoculation with central nervous system antigens and adjuvant or by the passive transfer of lymphocytes reactive with these antigens and is widely used as an animal model for multiple sclerosis (MS). There are reports that female sex and pregnancy affect EAE. Here we review the effects of biological sex and the effects of pregnancy on the clinical features (including disease susceptibility) and pathophysiology of EAE. We also review reports of the possible mechanisms underlying these differences. These include sex-related differences in the immune system and in the central nervous system, the effects of hormones and the sex chromosomes and molecules unique to pregnancy. We also review sex differences in the response to factors that can modify the course of EAE. Our conclusion is that the effects of biological sex in EAE vary amongst animal models and should not be widely extrapolated. In EAE, it is therefore essential that studies looking at the effects of biological sex or pregnancy give full information about the model that is used (i.e. animal strain, sex, the inducing antigen, timing of EAE induction in relation to pregnancy, etc.). In addition, it would be preferable if more than one EAE model were used, to show if any observed effects are generalizable. This is clearly a field that requires further work. However, understanding of the mechanisms of sex differences could lead to greater understanding of EAE, and suggest possible therapies for MS.

Too depressed to breathe: The longitudinal association between depressive symptoms and lung function among general middle-aged and older adults

Objective Most previous studies focusing on the association between depressive symptoms and lung function were conducted in patients with chronic lung diseases. This study aims to investigate the association of depressive symptoms with lung function among general Chinese middle-aged and older adults. Participants This study used data from the China Health and Retirement Longitudinal Study (CHARLS). Analyses were conducted with data from three waves (2011, 2013, and 2015) and restricted to those respondents aged 45 and older. Finally, 9487 individuals [mean age (SD) = 58.47 (9.19); female, 53.1%] were included in analysis. Methods Depressive symptoms were measured by the Chinese version of 10-item Center for Epidemiological Studies Depression Scale (CESD-10). Lung function was assessed by peak expiratory flow (PEF). Two-level linear mixed growth models were used to evaluate the longitudinal association between depressive symptoms and PEF. Results Depressive symptoms were significantly associated with PEF among general middle-aged and older adults (b = -1.85, p < 0.001) after adjusting for multiple confounding factors. A significant interaction between depressive symptoms and gender was found (b = 1.29, p < 0.001). The association between depressive symptoms and PEF was greater for men (b = -2.36, p < 0.001) than for women (b = -1.46, p < 0.001). Conclusions This longitudinal study found that increased depressive symptoms were associated with reduced PEF in middle-aged and older adults in China. Compared with women, men with a higher level of depressive symptoms experienced a greater decrement in PEF. Our findings suggest that it is possible to reduce the effects of PEF by improving psychological health among general middle-aged and older populations.

Endogenous estrogen deficiency and the development of chronic musculoskeletal pain: A review

Sexual dimorphism of chronic diseases is a phenomenon determined by differences in the hormonal status of men and women. In this regard, estrogens, which have a complex effect on the body, are of great interest. In particular, estrogens play an important role in the natural control of pain and inflammation. A decrease in estrogen levels associated with menopause or iatrogenic effects (hysterectomy, use of aromotase inhibitors), as well as mutations of genes responsible for the synthesis of structural components of membrane estrogen receptors (ESR1 and ESR2), can significantly reduce the positive effects of these hormones. Deficiency of estrogen can become one of the reasons for the development of serious pathological changes in particular, the formation of chronic pain associated with the pathology of the musculoskeletal system.

Sex Bias in Differentiated Thyroid Cancer

Differentiated thyroid cancers are more frequent in women than in men. These different frequencies may depend on differences in patient's behavior and in thyroid investigations. However, an impact on sexual hormones is likely, although this has been insufficiently elucidated. Estrogens may increase the production of mutagenic molecules in the thyroid cell and favor the proliferation and invasion of tumoral cells by regulating both the thyrocyte enzymatic machinery and the inflammatory process associated with tumor growth. On the other hand, the worse prognosis of thyroid cancer associated with the male gender is poorly explained.

Environmental risk factors are associated with autoimmune hepatitis

BACKGROUND

Failure of immunologic homeostasis and resultant hepatocyte destruction in autoimmune hepatitis (AIH) is likely the result of environmental triggers within a permissive genetic architecture.

AIMS

We aimed to identify risk factors associated with AIH in a well-phenotyped AIH cohort.

METHODS

We prospectively collected environmental questionnaires from 358 AIH cases and 563 healthy controls. Response frequencies were compared using logistic regression, adjusting for age at recruitment, sex and education.

RESULTS

AIH cases were more likely to ever have a urinary tract infection (UTI) (53.6% vs 33.9%, P < .001) and recurrent UTI (more than 1 per year) (23.5% vs 15.9%, P = .002) compared to controls. Female cases more frequently had ever used oral contraceptives (83.0% vs 73.7%, P = .006), fewer pregnancies (median = 1 vs 3, P < .001) and less often used hormone replacement therapy compared to controls (28.5% vs 60.1%, P < .001). Current smoking was more prevalent in cases (18.9% vs 7.4%, P = .022), yet no difference according to historical smoking behaviours was observed. Finally, cases were less likely to have history of mumps (32.4% vs 53.1%, P = .011) and rheumatic fever (1.1% vs 4.4%, P = .028), but reported higher vaccination frequency to chicken pox (38% vs 28.1%), measles (66.5% vs 39.3%), mumps (58.7% vs 34.6%), rubella (55.3% vs 32.7%), pertussis (59.8% vs 40.1%) and pneumococcus (47.2% VS 39.4%) (P < .002).

CONCLUSIONS

Environmental factors are important in AIH pathogenesis. Replication of these findings and prospective examination may provide new insight into AIH onset and outcomes.

Endothelial Dysfunction and Extra-Articular Neurological Manifestations in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic, systemic, inflammatory autoimmune disease that affects about 1% of the global population, with a female–male ratio of 3:1. RA preferably affects the joints, with consequent joint swelling and deformities followed by ankylosis. However, evidence has accumulated showing that patients suffering from RA can also develop extra-articular manifestations, including cardiovascular disease states, neuropathies, and multiorgan dysfunction. In particular, peripheral nerve disorders showed a consistent impact in the course of the disease (prevalence about 20%) mostly associated to vasculitis of the nerve vessels leading to vascular ischemia, axonal degeneration, and neuronal demyelination. The pathophysiological basis of this RA-associated microvascular disease, which leads to impairment of assonal functionality, is still to be better clarified. However, endothelial dysfunction and alterations of the so-called brain-nerve barrier (BNB) seem to play a fundamental role. This review aims to assess the potential mechanisms underlying the impairment of endothelial cell functionality in the development of RA and to identify the role of dysfunctional endothelium as a causative mechanism of extra-articular manifestation of RA. On the other hand, the potential impact of lifestyle and nutritional interventions targeting the maintenance of endothelial cell integrity in patients with RA will be discussed as a potential option when approaching therapeutic solutions in the course of the disease.

Ovarian hormones influence immune response to Staphylococcus aureus infection

Objective

Staphylococcus aureus infections remain associated with considerable morbidity and mortality in both hospitals and the community. There is little information regarding the role of ovarian hormones in infections caused by S. aureus. The aim of this study was to evaluate the effects of ovariectomy in the immune response induced by S. aureus.

Methods

Female mice BALB/c were ovariectomized (OVX) to significantly reduce the level of ovarian hormones. We also used sham-operated animals. The mice were inoculated intraperitoneally with S. aureus. Blood samples were collected for leukocyte count and bacterial quantification. The uterus and spleen were removed and weighed to calculate the uterine and splenic indexes. Lungs were removed and fractionated for immunohistochemical analysis for macrophage detection (anti-CD68) and relative gene expression of IL-6, IL-1β and TNF-α by RT-PCR.

Results

Ovariectomy enlarged spleen size and generally increased circulating lymphocytes. OVX females experienced a continuation of the initial reduction of lymphocytes and a monocyte and neutrophil late response compared to shams (p ≥ 0.05). Moreover, OVX females showed neutropenia after 168 h of infection (p ≥ 0.05). Macrophage response in the lungs were less pronounced in OVX females in the initial hours of infection (p ≥ 0.01). OVX females showed a higher relative gene expression of IL-1β, IL-6 and TNF-α in the lung at the beginning of the infection compared to sham females (p ≥ 0.01). Among the uninfected females, the OVX control females showed a higher expression of IL-6 in the lung compared to the sham control females (p ≥ 0.05). In this model, the lack of ovarian hormones caused a minor increase in circulating leukocytes during the initial stage of infection by S. aureus and increased pulmonary gene expression of IL-1β, IL-6, and TNF-α. Ovariectomy alone enlarged the spleen and increased circulating lymphocytes. Ovarian hormones acted as immunoprotectors against S. aureus infection.

Inhibiting Glycogen Synthase Kinase 3 Reverses Obesity-Induced White Adipose Tissue Inflammation by Regulating Apoptosis Inhibitor of Macrophage/CD5L-Mediated Macrophage Migration

Objective- Obesity-induced inflammation in white adipose tissue, characterized by increased macrophage infiltration and associated with macrophage population shift from anti-inflammatory M2 to proinflammatory M1 macrophages, largely contributes to obesity-induced insulin resistance and influences type 2 diabetes mellitus pathogenesis. GSK3 (glycogen synthase kinase 3), a serine/threonine kinase, has been reported to participate in various cellular processes. We sought to examine the potential mechanism by which GSK3, a serine/threonine kinase implicated in various cellular processes, modulates obesity-induced visceral adipose tissue (VAT) inflammation. Approach and Results- Male C57BL/6J mice were fed a high-fat diet for 10 weeks while being treated with vehicle control or GSK3 inhibitors SB216763 or CHIR99021. RNA-sequencing results using VAT demonstrated that GSK3 inhibitor treatment reversed obesity-specific expression of genes associated with inflammation. Consistently, GSK3 inhibition reduced obesity-induced VAT inflammation as characterized by decreased proinflammatory M1 macrophages but increased anti-inflammatory M2 macrophages in the VAT and reduced circulatory inflammatory monocytes. These anti-inflammatory effects of GSK3 inhibition were found to be driven, at least in part, by inhibiting production of apoptosis inhibitor of macrophage in macrophages via inactivating STAT3 to reduce free fatty acid and chemokine level produced from VAT to suppress the migration/chemotaxis of macrophages and monocytes. Conclusions- Our findings suggest that GSK3 may act as an important regulator of obesity-induced inflammation and characterize the novel role of GSK3 in shifting macrophage polarization and reinforce its therapeutic potential for obesity-induced inflammation and its associated diabetes mellitus.

Contributions of sex to cerebrovascular function and pathology

Sex differences exist in how cerebral blood vessels function under both physiological and pathological conditions, contributing to observed sex differences in risk and outcomes of cerebrovascular diseases (CBVDs), such as vascular contributions to cognitive impairment and dementia (VCID) and stroke. Throughout most of the lifespan, women are protected from CBVDs; however, risk increases following menopause, suggesting sex hormones may play a significant role in this protection. The cerebrovasculature is a target for sex hormones, including estrogens, progestins, and androgens, where they can influence numerous vascular functions and pathologies. While there is a plethora of information on estrogen, the effects of progestins and androgens on the cerebrovasculature are less well-defined. Estrogen decreases cerebral tone and increases cerebral blood flow, while androgens increase tone. Both estrogens and androgens enhance angiogenesis/cerebrovascular remodeling. While both estrogens and androgens attenuate cerebrovascular inflammation, pro-inflammatory effects of androgens under physiological conditions have also been demonstrated. Sex hormones exert additional neuroprotective effects by attenuating oxidative stress and maintaining integrity and function of the blood brain barrier. Most animal studies utilize young, healthy, gonadectomized animals, which do not mimic the clinical conditions of aging individuals likely to get CBVDs. This is also concerning, as sex hormones appear to mediate cerebrovascular function differently based on age and disease state (e.g. metabolic syndrome). Through this review, we hope to inspire others to consider sex as a key biological variable in cerebrovascular research, as greater understanding of sex differences in cerebrovascular function will assist in developing personalized approaches to prevent and treat CBVDs.

Sex differences in innate immunity and its impact on opioid pharmacology

Morphine has been and continues to be one of the most potent and widely used drugs for the treatment of pain. Clinical and animal models investigating sex differences in pain and analgesia demonstrate that morphine is a more potent analgesic in males than in females. In addition to binding to the neuronal μ-opioid receptor, morphine binds to the innate immune receptor toll-like receptor 4 (TLR4), located on glial cells. Activation of glial TLR4 initiates a neuroinflammatory response that directly opposes morphine analgesia. Females of many species have a more active immune system than males; however, few studies have investigated glial cells as a potential mechanism driving sexually dimorphic responses to morphine. This Mini-Review illustrates the involvement of glial cells in key processes underlying observed sex differences in morphine analgesia and suggests that targeting glia may improve current treatment strategies for pain. © 2016 Wiley Periodicals, Inc.

Female gonadal hormone effects on microglial activation and functional outcomes in a mouse model of moderate traumatic brain injury

AIM

To address the hypothesis that young, gonad-intact female mice have improved long-term recovery associated with decreased neuroinflammation compared to male mice.

METHODS

Eight to ten week-old male, female, and ovariectomized (OVX) mice underwent closed cranial impact. Gonad-intact female mice were injured only in estrus state. After injury, between group differences were assessed using complementary immunohistochemical staining for microglial cells at 1 h, mRNA polymerase chain reaction for inflammatory markers at 1 h after injury, Rotarod over days 1-7, and water maze on days 28-31 after injury.

RESULTS

Male mice had a greater area of injury (P = 0.0063), F4/80-positive cells (P = 0.032), and up regulation of inflammatory genes compared to female mice. Male and OVX mice had higher mortality after injury when compared to female mice (P = 0.043). No group differences were demonstrated in Rotarod latencies (P = 0.62). OVX mice demonstrated decreased water maze latencies compared to other groups (P = 0.049).

CONCLUSION

Differences in mortality, long-term neurological recovery, and markers of neuroinflammation exist between female and male mice after moderate traumatic brain injury (MTBI). Unexpectedly, OVX mice have decreased long term neurological function after MTBI when compared to gonad intact male and female mice. As such, it can be concluded that the presence of female gonadal hormones may influence behavioural outcomes after MTBI, though mechanisms involved are unclear.

Estrogen regulation of gene expression in the teleost fish immune system

Elucidating the mechanisms of estrogens-induced immunomodulation in teleost fish is of great importance due to the observed worldwide continuing decrease in pristine environments. However, little is know about the immunotoxicological consequences of exposure to these chemicals in fish, or of the mechanisms through which these effects are mediated. In this review, we summarize the results showing estrogens (natural or synthetic) acting through estrogen receptors and regulating specific target genes, also through microRNAs (miRNAs), leading to modulation of the immune functioning. The identification and characterization of miRNAs will provide new opportunities for functional genome research on teleost immune system and can also be useful when screening for novel molecule biomarkers for environmental pollution.

The restorative role of annexin A1 at the blood-brain barrier

Annexin A1 is a potent anti-inflammatory molecule that has been extensively studied in the peripheral immune system, but has not as yet been exploited as a therapeutic target/agent. In the last decade, we have undertaken the study of this molecule in the central nervous system (CNS), focusing particularly on the primary interface between the peripheral body and CNS: the blood-brain barrier. In this review, we provide an overview of the role of this molecule in the brain, with a particular emphasis on its functions in the endothelium of the blood-brain barrier, and the protective actions the molecule may exert in neuroinflammatory, neurovascular and metabolic disease. We focus on the possible new therapeutic avenues opened up by an increased understanding of the role of annexin A1 in the CNS vasculature, and its potential for repairing blood-brain barrier damage in disease and aging.

Sex differences in the impact of CYP2C19 polymorphisms and low-grade inflammation on coronary microvascular disorder

Categorization as a cytochrome P-450 (CYP) 2C19 poor metabolizer (PM) is reported to be an independent risk factor for cardiovascular disease. It is correlated with an increase in the circulating levels of high-sense C-reactive protein (hs-CRP) in women only, although its role in coronary microcirculation is unclear. We examined sex differences in the impact of the CYP2C19 genotype and low-grade inflammation on coronary microvascular disorder (CMVD). We examined CYP2C19 genotypes in patients with CMVD (n = 81) and in healthy subjects as control (n = 81). CMVD was defined as the absence of coronary artery stenosis and epicardial spasms, the presence of inverted lactic acid levels between the intracoronary and coronary sinuses, or an adenosine triphosphate-induced coronary flow reserve ratio < 2.5. CYP2C19 PMs have two loss-of-function (LOF) alleles (*2, *3). Extensive metabolizers have no LOF alleles, and intermediate metabolizers have one LOF allele. The ratio of CYP2C19 PM and hs-CRP levels in CMVD was significantly higher than that of controls, especially in women (40.9 vs. 13.8%, P = 0.013; 0.11 ± 0.06 vs. 0.07 ± 0.04 mg/dl, P = 0.001). Moreover, in each CYP2C19 genotype, hs-CRP levels in CMVD in CYP2C19 PMs were significantly higher than those of the controls, especially in women (0.15 ± 0.06 vs. 0.07 ± 0.03, P = 0.004). Multivariate analysis for CMVD indicated that the female sex, current smoking, and hypertension were predictive factors, and that high levels of hs-CRP and CYP2C19 PM were predictive factors in women only (odds ratio 3.5, 95% confidence interval 1.26-9.93, P = 0.033; odds ratio 4.1, 95% confidence interval 1.15-14.1, P = 0.038). CYP2C19 PM genotype may be a new candidate risk factor for CMVD via inflammation exclusively in the female population.

Time-dependent behavioral, neurochemical, and metabolic dysregulation in female C57BL/6 mice caused by chronic high-fat diet intake

High-fat diet (HFD) induced obesity is associated not only with metabolic dysregulation, e.g., impaired glucose homeostasis and insulin sensitivity, but also with neurological dysfunction manifested with aberrant behavior and/or neurotransmitter imbalance. Most studies have examined HFD's effects predominantly in male subjects, either in the periphery or on the brain, in isolation and after a finite feeding period. In this study, we evaluated the time-course of selected metabolic, behavioral, and neurochemical effects of HFD intake in parallel and at multiple time points in female (C57BL/6) mice. Peripheral effects were evaluated at three feeding intervals (short: 5-6 weeks, long: 20-22 weeks, and prolonged: 33-36 weeks). Central effects were evaluated only after long and prolonged feeding durations; we have previously reported those effects after the short (5-6 weeks) feeding duration. Ongoing HFD feeding resulted in an obese phenotype characterized by increased visceral adiposity and, after prolonged HFD intake, an increase in liver and kidney weights. Peripherally, 5 weeks of HFD intake was sufficient to impair glucose tolerance significantly, with the deleterious effects of HFD being greater with prolonged intake. Similarly, 5 weeks of HFD consumption was sufficient to impair insulin sensitivity. However, sensitivity to insulin after prolonged HFD intake was not different between control, low-fat diet (LFD) and HFD-fed mice, most likely due to age-dependent decrease in insulin sensitivity in the LFD-fed mice. HFD intake also induced bi-phasic hepatic inflammation and it increased gut permeability. Behaviorally, prolonged intake of HFD caused mice to be hypoactive and bury fewer marbles in a marble burying task; the latter was associated with significantly impaired hippocampal serotonin homeostasis. Cognitive (short-term recognition memory) function of mice was unaffected by chronic HFD feeding. Considering our prior findings of short-term (5-6 weeks) HFD-induced central (hyperactivity/anxiety and altered ventral hippocampal neurochemistry) effects and our current results, it seems that in female mice some metabolic/inflammatory dysregulations caused by HFD, such as gut permeability, appear early and persist, whereas others, such as glucose intolerance, are exaggerated with continuous HFD feeding; behaviorally, prolonged HFD consumption mainly affects locomotor activity and anxiety-like responses, likely due to the advanced obesity phenotype; neurochemically, the serotonergic system appears to be most sensitive to continued HFD feeding.

Regulation of cyclooxygenase-2 expression in rat oviductal epithelial cells: Evidence for involvement of GPR30/Src kinase-mediated EGFR signaling

The oviduct plays a crucial role in female reproduction by regulating gamete transport, providing a specific microenvironment for fertilization and early embryonic development. Cyclooxygenase (COX)-derived prostaglandins play essential role in carrying out these oviduct-specific functions. Estrogen upregulates COX-2 expression in rat oviduct; however, the mechanisms responsible for regulation of COX-2 expression in rat oviductal epithelial cells (OECs) remain unclear. In the present study, we proposed that estrogen induces COX-2 expression via G-protein coupled receptor i.e., GPR30 in OECs. To investigate this hypothesis, we examined the effects of E2-BSA, ICI 182,780, GPR30 agonist and GPR30 antagonist on COX-2 expression and explored potential signaling pathway leading to COX-2 expression. Co-localization experiments revealed GPR30 to be primarily located in the peri-nuclear space, which was also the site of E2-BSA-fluorescein isothiocyanate (E2-BSA-FITC) binding. The E2-BSA induced-COX-2 and prostaglandin release were subjected to regulation by both EGFR and PI3K signaling as inhibitors of c-Src kinase (PP2), EGFR (EGFR inhibitor) and PI-3 kinase (LY294002) attenuated E2-BSA mediated effect. These results suggest that EGFR transactivation leading to activation of PI-3K/Akt pathway participates in COX-2 expression in rat OECs. Interestingly, E2-BSA induced COX-2 expression and subsequent prostaglandin release were abolished by NF-κB inhibitor. In addition, E2-BSA induced the nuclear translocation of p65-NF-κB and up-regulated the NF-κB promoter activity in rat OECs. Taken together, results demonstrated that E2-BSA induced the COX-2 expression and consequent PGE2 and PGF2α release in rat OECs. These effects are mediated through GPR30-derived EGFR transactivation and PI-3K/Akt cascade leading to NF-κB activation.

Gender-Specific Effect of CYP2C8*3 on the Risk of Essential Hypertension in Bulgarian Patients

We conducted a case-control study to determine the contribution of polymorphisms in CYP2C8 (CYP2C8*3) and CYP2J2 (CYP2J2*7) to increased risk of coronary artery disease and essential hypertension in Bulgarians. The current analysis included 192 unrelated hypertensive patients, 261 patients with angiographically documented CAD (153 with myocardial infarction and 108 without myocardial infarction), and 496 population controls. The CYP2C8*3 and CYP2J2*7 polymorphisms were genotyped by TaqMan SNP Genotyping Assay. PLINK version 1.07 was used for the statistical analysis. No overall association was observed for the studied polymorphisms with coronary artery disease and essential hypertension. The frequency of -50T mutant allele of CYP2J2*7 was significantly higher in male with coronary artery disease without history of myocardial infarction (OR 2.16 95% CI 1.04-4.48 p = 0.035) compared to population control group, but this association did not survive after Bonferroni correction (p adj = 0.07). A significant association of CYP2C8*3 allele with increased risk of essential hypertension has found in men (OR 2.12 95% CI 1.18-3.81 p = 0.015) and this relationship remained significant after adjustment for multiple comparisons (p adj = 0.03). This is the first study showing significant gene-sex interaction for CYP2C8*3 with twofold increase in the relative risk of essential hypertension and a similar tendency for CYP2J2*7 associated with coronary artery disease without myocardial infarction in Bulgarian males. The association is not seen in females and in the whole group of patients. This result could be partly explained by the effect of estrogens on the vascular tone of coronary arteries and CYP2C8 gene expression.

Age- and sex-specific differences in blood-borne microvesicles from apparently healthy humans

Background

Sex differences in incidence of cardiovascular disease may reflect age-associated intravascular cellular activation resulting in shedding of cell membrane-derived bioactive microvesicles (MV or microparticles) into the blood. Concentrations of cell-specific MV in blood have the potential to be a diagnostic/prognostic marker of pathology, but ranges of MV must first be established in healthy individuals. This study identified cellular origin of blood-borne MV >0.2 μm in blood of apparently healthy women and men aged from 20–70 years.

Methods

Venous blood from apparently healthy participants in the Mayo Clinic Biobank was collected into tubes containing protease inhibitors as the anticoagulant. MV were isolated by standardized differential centrifugation and characterized by digital flow cytometer. Each cellular origin of MV was verified by two different antibodies with strong correlation between the two distinct antibodies (e.g., for platelet-derived MV, r² = 0.97).

Results

MV derived from platelets were the most abundant type of MV in blood from women and men in all age groups. Total numbers of phosphatidylserine, P-selectin, and platelet- and endothelium-derived MV were significantly (P < 0.05) greater in women than men. Numbers of MV from erythrocytes and stem/progenitor cells were significantly lower in premenopausal women than age-matched men. Number of tissue factor pathway inhibitor positive MV were significantly (P < 0.05) lower whereas erythrocyte-derived MV were significantly higher in postmenopausal women compared to premenopausal women. In women, there was a positive relationship between age and erythrocyte-derived MV (ρ = 0.28; P = 0.009), while in men adipocyte-derived MV increased with age (ρ = 0.33; P = 0.01).

Conclusions

This study provides ranges for cellular origin of blood-borne MV in age-matched, apparently healthy women and men from which to compare diagnostic and prognostic uses of blood-borne MV in larger studies and patient population. In addition, sex- and age-specific differences in phosphatidylserine, platelet-, endothelium-, erythrocyte-, and adipocyte-derived blood-borne MV may contribute to differential progression of cardiovascular disease in women compared to men.

A comprehensive assessment of environmental exposures among 1000 North American patients with primary sclerosing cholangitis, with and without inflammatory bowel disease

BACKGROUND

The relationships between primary sclerosing cholangitis (PSC) and the environment are largely unknown.

AIM

To validate associations reported in previous studies and to identify novel environmental exposures among PSC patients.

METHODS

We performed a multicenter, case-control analysis utilising self-administered questionnaires. Responses between cases (n = 1000) and controls (n = 663) were compared using multivariable logistic regression adjusted for age and gender. The model was further stratified based on inflammatory bowel disease (IBD) status (with IBD n = 741 without IBD n = 259).

RESULTS

Smoking was associated with PSC only when IBD was present (OR, 0.5; 95% CI 0.4-0.7) but not among those PSC patients without IBD (OR, 0.9; 95% CI 0.7-1.2). Compared to controls, women with PSC (irrespective of the presence of IBD) were less likely to have received hormone replacement therapy (HRT; OR, 0.5; 95% CI 0.4-0.7) and were more likely to have recurrent urinary tract infections (OR, 1.6; 95% CI 1.2-2.3). PSC patients regardless of gender or IBD status were less likely to eat fish (OR, 0.4; 95% CI 0.3-0.6) and grilled/barbecued meat (OR, 0.8; 95% CI 0.7-0.9). In contrast, PSC patients with and without IBD were more likely to consume steak/burgers that were more well done (OR, 1.3; 95% CI 1.2-1.5).

CONCLUSIONS

IBD (rather than PSC) is associated with smoking. Women with PSC are more likely to have recurrent urinary tract infections and less likely to receive HRT. Dietary intake and methods of food preparation differ in PSC patients when compared to controls.

Symptomatology of irritable bowel syndrome and inflammatory bowel disease during the menstrual cycle

Gender-related physiological variations in gastrointestinal (GI) symptomatology have been observed in women of reproductive age. Many women experience cyclical changes in GI symptomatology during their menstrual cycle, particularly alteration in their bowel habits. Physiological studies of healthy women during the menstrual cycle showed a prolonged GI transit time during the luteal phase, either in the oro-cecum route or in the colon. Worsened GI symptoms, such as abdominal pain, bloating or diarrhea are observed in patients with irritable bowel syndrome (IBS) during menses. This may be due to elevated prostaglandin levels during menses, with an enhanced perception of viscera-somatic stimuli resulting in nausea, abdominal distension and pain. Also patients with IBS or IBD demonstrate a cyclical pattern more closely related to their bowel habits than healthy controls. Women with inflammatory bowel disease (IBD) also have exacerbated symptoms during menses; however, it is unclear whether this relates to physiological variation or disease exacerbation in IBS or IBD. Studies examining the association of the menstrual cycle and GI symptomatology in patients with IBS or IBD, have not yet clarified the underlying mechanisms. Moreover medications—such as non-steroidal anti-inflammatory drugs and oral contraceptive pills used for dysmenorrhea and menstrual migraine in those patients have not well been controlled for in the previous studies, which can contribute to further bias. Understanding changes in GI symptomatology during the menstrual cycle may help to determine the true extent of disease exacerbation and proper management strategy.

Disruption of estrous cycle homeostasis in mice with experimental autoimmune encephalomyelitis

Multiple sclerosis (MS) is widely viewed as a prototypic human autoimmune disease involving proinflammatory T cells that induce lesions in the central nervous system (CNS) in response to myelin self proteins. Although the impact of sex hormones on MS is well recognized, the converse effects of autoimmunity on sex hormones are still unclear. The current study was designed to assess the impact of CNS autoimmunity on female reproductive physiology. In order to identify subtle hormonal disturbances as a result of autoimmunity, we analyzed the estrous cycle in SJL/J mice after active induction of experimental autoimmune encephalomyelitis (EAE), an animal model with substantial similarities to MS. Here we show that CNS autoimmunity significantly shortens the murine estrous cycle. This shortening of the estrous cycle is characterized by a dramatic decrease in the length of the metestrus-diestrus luteal phase partially offset by a highly significant but less dramatic elongation of the proestrus-estrus follicular phase of the uterine cycle. Thus, our study provides experimental evidence for a direct causal link between CNS autoimmunity and disruption of the homeostatic balance of the uterine cycle often observed in women with MS.

A pathway approach to evaluating the association between the CHIEF pathway and risk of colorectal cancer

Inflammation, hormones and energy-related factors have been associated with colorectal cancer (CRC) and it has been proposed that convergence and interactions of these factors importantly influence CRC risk. We have previously hypothesized that genetic variation in the CHIEF (convergence of hormones, inflammation and energy-related factors) pathway would influence risk of CRC. In this paper, we utilize an Adaptive Rank Truncation Product (ARTP) statistical method to determine the overall pathway significance and then use that method to identify the key elements within the pathway associated with disease risk. Data from two population-based case-control studies of colon (n = 1555 cases and 1956 controls) and rectal (n = 754 cases and 959 controls) cancer were used. We use ARTP to estimate pathway and gene significance and polygenic scores based on ARTP findings to further estimate the risk associated with the pathway. Associations were further assessed based on tumor molecular phenotype. The CHIEF pathway was statistically significant for colon cancer (P(ARTP)= 0.03) with the most significant interferons (P(ARTP) = 0.0253), JAK/STAT/SOCS (P(ARTP) = 0.0111), telomere (P(ARTP) = 0.0399) and transforming growth factor β (P(ARTP) = 0.0043) being the most significant subpathways for colon cancer. For rectal cancer, interleukins (P(ARTP) = 0.0235) and selenoproteins (P ARTP = 0.0047) were statistically significant although the pathway overall was of borderline significance (P(ARTP) = 0.06). Interleukins (P(ARTP) = 0.0456) and mitogen-activated protein kinase (P(ARTP) = 0.0392) subpathways were uniquely significant for CpG island methylator phenotype-positive colon tumors. Increasing number of at-risk alleles was significantly associated with both colon [odds ratio (OR) = 6.21, 95% confidence interval (CI): 4.72, 8.16] and rectal (OR = 7.82, 95% CI: 5.26, 11.62) cancer. We conclude that elements of the CHIEF pathway are important for CRC risk.

Pregnancy-induced gingivitis and OMICS in dentistry: in silico modeling and in vivo prospective validation of estradiol-modulated inflammatory biomarkers

Pregnancy-associated gingivitis is a bacterial-induced inflammatory disease with a remarkably high prevalence ranging from 35% to 100% across studies. Yet little is known about the attendant mechanisms or diagnostic biomarkers that can help predict individual susceptibility for rational personalized medicine. We aimed to define inflammatory proteins in saliva, induced or inhibited by estradiol, as early diagnostic biomarkers or target proteins in relation to pregnancy-associated gingivitis. An in silico gene/protein interaction network model was developed by using the STITCH 3.1 with "experiments" and "databases" as input options and a confidence score of 0.700 (high confidence). Salivary estradiol, interleukin (IL)-1β and -8, myeloperoxidase (MPO), matrix metalloproteinase (MMP)-2, -8, and -9, and tissue inhibitor of matrix metalloproteinase (TIMP)-1 levels from 30 women were measured prospectively three times during pregnancy and twice during postpartum. In silico analysis revealed that estradiol interacts with IL-1β and -8 by an activation link when the "actions view" was consulted. In saliva, estradiol concentrations associated positively with TIMP-1 and negatively with MPO and MMP-8 concentrations. When the gingival bleeding on probing percentage (BOP%) was included in the model as an effect modifier, the only association, a negative one, was found between estradiol and MMP-8. Throughout gestation, estradiol modulates the inflammatory response by inhibiting neutrophilic enzymes, such as MMP-8. The interactions between salivary degradative enzymes and proinflammatory cytokines during pregnancy suggest promising ways to identify candidate biomarkers for pregnancy-associated gingivitis, and for personalized medicine in the field of dentistry. Finally, we call for greater investments in, and action for biomarker research in periodontology and dentistry that have surprisingly lagged behind in personalized medicine compared to other fields, such as cancer research.

Female, but not male, mice show delayed cutaneous wound healing following aspirin administration

Cyclo-oxygenase (COX) is an enzyme that participates in the wound healing process. Aspirin, a non-steroidal anti-inflammatory drug, simultaneously inhibits the aromatase activity of COX-1 and COX-2 isoforms, which is needed for prostaglandin synthesis. The aim of the present study was to determine whether aspirin, and thus COX inhibition, distinctly affects cutaneous wound healing in female and male mice. Female and male BALB/c mice were treated with aspirin (25 mg/kg per day) for 16 days until they were killed. The control group received vehicle (saline) only. A full-thickness excisional lesion was made on the back, 2 days after aspirin administration started, and macroscopic, histological and biochemical parameters were evaluated. Sections were stained and immunostained for microscopic analysis. Myeloperoxidase (MPO) activity, hydroxyproline quantity and the protein expression of von Willebrand factor (vWF) and vascular endothelial growth factor (VEGF) were also determined. Female control and aspirin-treated groups exhibited delayed wound closure and re-epithelization compared with the male control and aspirin-treated groups, respectively. The female control group exhibited reduced MPO activity and a decreased number of macrophage inhibitory factor-positive cells compared with the male control group. In the female aspirin-treated group, MPO activity and the number of F4/80-positive macrophages was higher than in the control group. Collagen was reduced only in the female aspirin-treated group. The expression of vWF and VEGF protein was increased in the female aspirin-treated group. In conclusion, aspirin administration impaired the wound healing process in BALB/c female, but not male, mice.

The G protein-coupled estrogen receptor 1 (GPER1/GPR30) agonist G-1 regulates vascular smooth muscle cell Ca²⁺ handling

The G protein-coupled estrogen receptor GPER1/GPR30 is implicated in blood pressure regulation but the mechanisms are not identified. Here, we hypothesize that GPER1 controls blood pressure by regulating vascular smooth muscle cell Ca(2+) handling. Treatment with the GPER1 agonist G-1 (in the µM concentration range) acutely reduced spontaneous and synchronous Ca(2+) spike activity in A7r5 vascular smooth muscle cells expressing mRNA for GPER1. Furthermore, G-1 (1 µM) attenuated the thromboxane A2 analogue U46619-stimulated Ca(2+) spike activity but had no effect on the U46619-induced increase in the basal level of Ca(2+). The voltage-sensitive L-type Ca(2+) channel blocker nifedipine (100 nM) reduced Ca(2+) spike activity similar to G-1. Pharmacological, but not physiological, concentrations of the estrogen 17β-estradiol reduced Ca(2+) spike activity. The GPER1 antagonist G-15 blocked G-1-induced downregulation of Ca(2+) spike activity, supporting a GPER1-dependent mechanism. G-1 (1 µM) and nifedipine (100 nM) attenuated the 30-mM KCl-evoked rise in intracellular Ca(2+) concentration, suggesting that G-1 blocks inflow of Ca(2+) via voltage-sensitive Ca(2+) channels. In conclusion, we demonstrate that the GPER1 agonist G-1 regulates vascular smooth muscle cell Ca(2+) handling by lowering Ca(2+) spike activity, suggesting a role for this mechanism in GPER1-mediated control of blood pressure. © 2013 S. Karger AG, Basel.

Differential effects of LPS from Escherichia coli and Porphyromonas gingivalis on IL-6 production in human periodontal ligament cells

OBJECTIVE

Periodontal ligament (PDL) cells produce IL-6 upon stimulation with inflammation promoters, but the signaling pathways involved have not been characterized. This study investigates underlying mechanisms behind regulation of PDL cell IL-6 production by E. coli and P. gingivalis LPS.

MATERIALS AND METHODS

Human PDL cells, endothelial cells and monocytes were stimulated with E. coli or P. gingivalis LPS in the presence or absence of pharmacological agents in order to disclose pathways involved in LPS signaling. Gene expression and cellular protein levels were assessed by quantitative real-time PCR and ELISA, respectively.

RESULTS

Stimulation with LPS from E. coli (1 µg/ml) for 24 h enhanced PDL cell IL-6 expression several fold, demonstrated both on transcript and protein levels, but P. gingivalis LPS (1-5 µg/ml) had no effect. TLR2 mRNA was more highly expressed than TLR4 transcript in PDL cells. Treatment with the non-selective nitric oxide synthase inhibitor L-NAME (100 µM) reduced E. coli LPS-induced PDL cell IL-6 by 30%, while neither aminoguanidine (10 µM), an inhibitor of inducible nitric oxide synthase, nor estrogen (17β-estradiol, 100 nM) influenced IL-6. Treatment with the glucocorticoid dexamethasone (1 µM) totally prevented the E. coli LPS-induced PDL cell IL-6. In endothelial cells, neither E. coli LPS nor P. gingivalis LPS promoted IL-6 production. In monocytes, serving as positive control, both E. coli and P. gingivalis LPS stimulated IL-6.

CONCLUSIONS

E. coli LPS but not P. gingivalis LPS stimulates PDL cell IL-6 production through a glucocorticoid-sensitive mechanism involving nitric oxide formation, probably via endothelial nitric oxide synthase.

Sex, stroke, and inflammation: the potential for estrogen-mediated immunoprotection in stroke

Stroke is the third leading cause of death and the primary cause of disability in the developed world. Experimental and clinical data indicate that stroke is a sexually dimorphic disease, with males demonstrating an enhanced intrinsic sensitivity to ischemic damage throughout most of their lifespan. The neuroprotective role of estrogen in the female brain is well established, however, estrogen exposure can also be deleterious, especially in older women. The mechanisms for this remain unclear. Our current understanding is based on studies examining estrogen as it relates to neuronal injury, yet cerebral ischemia also induces a robust sterile inflammatory response involving local and systemic immune cells. Despite the potent anti-inflammatory effects of estrogen, few studies have investigated the contribution of estrogen to sex differences in the inflammatory response to stroke. This review examines the potential role for estrogen-mediated immunoprotection in ischemic injury.

Sex differences in effects and use of anti-inflammatory drugs

Gender accounts for important differences in the incidence, prevalence, and course of many immunoinflammatory diseases. However, similar treatment strategies, such as the use of nonsteroidal anti-inflammatory drugs (NSAIDs) and tumor necrosis factor-α (TNF-α) inhibitors, have been advocated for both genders. Experimental studies found that molecular mechanisms of inflammation differ in males and females. In our chapter we summarize the data concerning gender-specific aspects about prevalence of use, drug survival, responsiveness, and adverse drug effects of NSAIDs and TNF-α inhibitors. Gender-related differences in the prevalence and course of many autoimmune diseases as well as differences in effects of anti-inflammatory drugs should be considered for the tailored treatment options for these patients.

Female mice are protected against high-fat diet induced metabolic syndrome and increase the regulatory T cell population in adipose tissue

Sex differences in obesity-induced complications such as type 2 diabetes have been reported. The aim of the study was to pinpoint the mechanisms resulting in different outcome of female and male mice on a high-fat diet (HFD). Mice fed control or HFD were monitored for weight, blood glucose, and insulin for 14 weeks. Circulating chemokines, islet endocrine function and blood flow, as well as adipose tissue populations of macrophages and regulatory T-lymphocytes (T_reg) were thereafter assessed. Despite similar weight (43.8±1.0 and 40.2±1.5 g, respectively), male but not female mice developed hyperinsulinemia on HFD as previously described (2.5±0.7 and 0.5±0.1 pmol/l, respectively) consistent with glucose intolerance. Male mice also exhibited hypertrophic islets with intact function in terms of insulin release and blood perfusion. Low-grade, systemic inflammation was absent in obese female but present in obese male mice (IL-6 and mKC, males: 77.4±17 and 1795±563; females: 14.6±4.9 and 240±22 pg/ml), and the population of inflammatory macrophages was increased in intra-abdominal adipose tissues of high-fat-fed male but not female mice. In contrast, the anti-inflammatory T_reg cell population increased in the adipose tissue of female mice in response to weight gain, while the number decreased in high-fat-fed male mice. In conclusion, female mice are protected against HFD-induced metabolic changes while maintaining an anti-inflammatory environment in the intra-abdominal adipose tissue with expanded T_reg cell population, whereas HFD-fed male mice develop adipose tissue inflammation, glucose intolerance, hyperinsulinemia, and islet hypertrophy.

The G protein-coupled oestrogen receptor 1 agonist G-1 disrupts endothelial cell microtubule structure in a receptor-independent manner

The G protein-coupled oestrogen receptor GPER1, also known as GPR30, has been implicated in oestrogen signalling, but the physiological importance of GPER1 is not fully understood. The GPER1 agonist G-1 has become an important tool to assess GPER1-mediated cellular effects. Here, we report that this substance, besides acting via GPER1, affects the microtubule network in endothelial cells. Treatment with G-1 (3 μM) for 24 h reduced DNA synthesis by about 60 % in mouse microvascular endothelial bEnd.3 cells. Treatment with 3 μM G-1 prevented outgrowth of primary endothelial cells from mouse aortic explants embedded in Matrigel. Treatment with G-1 (0.3-3 μM) for 24 h disrupted bEnd.3 cell and HUVEC microtubule structure in a concentration-dependent manner as assessed by laser-scanning confocal immunofluorescence microscopy. G-1-induced (3 μM) disruption of microtubule was observed also after acute (3 and 6 h) treatment and in the presence of the protein synthesis inhibitor cycloheximide. Disruption of microtubules by 3 μM G-1 was observed in aortic smooth muscle cells obtained from both GPER1 knockout and wild-type mice, suggesting that G-1 influences microtubules through a mechanism independent of GPER1. G-1 dose dependently (10-50 μM) stimulated microtubule assembly in vitro. On the other hand, microtubules appeared normal in the presence of 10-50 μM G-1 as determined by electron microscopy. We suggest that G-1-promoted endothelial cell anti-proliferation is due in part to alteration of microtubule organization through a mechanism independent of GPER1. This G-1-promoted mechanism may be used to block unwanted endothelial cell proliferation and angiogenesis such as that observed in, e.g. cancer.

Estrogen inhibits apoptosis and promotes CC motif chemokine ligand 13 expression on synovial fibroblasts in rheumatoid arthritis

OBJECTIVE

Female patients have a higher prevalence of rheumatoid arthritis (RA) than male patients, suggesting that female sex hormones contribute to the disease pathogenesis. We herein report the findings of our study, which was conducted to clarify the role of estrogen in the pathogenesis of RA.

METHODS

Cultured human synovial fibroblasts from a patient with RA were treated with 17β-estradiol (E(2)). The effects of E(2) against cellular activation and apoptosis were evaluated. To identify the disease-related genes altered by E(2) treatment, the changes in the gene expression of the cells stimulated with and without E(2) were evaluated using a microarray analysis.

RESULTS

We found that E(2)-mediated cellular activation signaling through extracellular signal-regulated kinase (ERK)-1/2. E(2) possessed a suppressive effect for apoptosis and a promotive effect for tumor necrosis factor (TNF)-α-induced matrix metalloproteinase (MMP)-3 production on the synovial fibroblasts. A microarray analysis revealed that E(2) profoundly upregulated CC motif chemokine ligand 13 (CCL13) gene expression.

CONCLUSIONS

E(2) could mediate cellular activation signaling through ERK-1/2 on the synovial fibroblasts. The present data suggest that E(2) has adverse effects on the pathogenesis of RA as a result of unregulated cell death, increased TNF-α-induced MMP-3 production, and CCL13 overproduction, subsequently resulting in the disease progression of RA.

G protein-coupled oestrogen receptor 1 (GPER1)/GPR30: a new player in cardiovascular and metabolic oestrogenic signalling

Oestrogens are important sex hormones central to health and disease in both genders that have protective effects on the cardiovascular and metabolic systems. These hormones act in complex ways via both genomic and non-genomic mechanisms. The genomic mechanisms are relatively well characterized, whereas the non-genomic ones are only beginning to be explored. Two oestrogen receptors (ER), ERα and ERβ, have been described that act as nuclear transcription factors but can also associate with the plasma membrane and influence cytosolic signalling. ERα has been shown to mediate both anti-atherogenic effects and pro-survival effects in pancreatic β-cells. In recent years, a third membrane-bound ER has emerged, G protein-coupled receptor 30 or G protein-coupled oestrogen receptor 1 (GPER1), which mediates oestrogenic responses in cardiovascular and metabolic regulation. Both GPER1 knock-out models and pharmacological agents are now available to study GPER1 function. These tools have revealed that GPER1 activation may have several beneficial effects in the cardiovascular system including vasorelaxation, inhibition of smooth muscle cell proliferation, and protection of the myocardium against ischaemia/reperfusion injury, and in the metabolic system including stimulation of insulin release and protection against pancreatic β-cell apoptosis. Thus, GPER1 is emerging as a candidate therapeutic target in both cardiovascular and metabolic disease.

Association between social isolation and inflammatory markers in depressed and non-depressed individuals: results from the MONICA/KORA study

INTRODUCTION

Depressed individuals not only suffer from chronic low grade inflammation, but also exhibit an inflammatory hyper-responsiveness to acute stress. We investigate whether chronic stress also induces an exaggerated inflammatory response in individuals with increased depression features. As model for chronic stress, social isolation was chosen.

METHODS

Interleukin (IL)-6 and hs-CRP levels were assessed in 1547 subjects (847 men and 700 women), derived from the population-based MONICA/KORA study. Standardized questionnaires were used to assess depressed mood (depression and exhaustion subscale) and social isolation (social network index). The relationship between the two inflammatory markers, social isolation and depressed mood was examined taking into account interactions social isolation × depressed mood using multivariable linear regression models, adjusted for age, BMI, smoking, alcohol, and physical activity. Analyses were performed in men and women separately.

RESULTS

We observed a significant interaction between depressed mood and social isolation regarding IL-6 and hs-CRP, respectively in men (p-value=0.02 for IL-6 and <0.01 for hs-CRP), evidencing a substantial synergistic effect of social isolation, and depressed mood on inflammatory responses. Furthermore, depressed and socially isolated men had highly significantly elevated IL-6 levels (geometric mean: 3.76 vs. 1.92 pg/ml, p-value <0.01) and heightened hs-CRP levels (geometric mean: 2.01 vs. 1.39 mg/l, p=0.08) in comparison with non-depressed and socially integrated men. In women, no significant associations were seen.

CONCLUSION

The interaction of depressed mood and social isolation elicits a substantial synergistic impact on inflammatory markers in men, but not in depressed women.

Estrogen-responsive genes in macrophages of the bony fish gilthead seabream: a transcriptomic approach

The role of sex steroids in the modulation of fish immune responses has received little attention. Previous studies have demonstrated that 17β-estradiol (E(2)) is able to alter the response of gilthead seabream leukocytes to infectious agents. We have used suppression subtractive hybridization to identify genes upregulated by E(2) (50 ng/ml) in macrophage cultures from gilthead seabream. We isolated 393 up-regulated cDNA fragments that led to the identification of 162 candidate estrogen-responsive genes. Functional analyses revealed the presence of several enriched immune processes and molecular pathways. The E(2) up-regulation of some immune-relevant genes was further confirmed by real time RT-PCR. Bioinformatics analysis revealed the ability of E(2) to orchestrate profound alterations in the macrophage expression profile, especially immune-related processes and pathways. This is the first report on E(2)-dependent modifications of fish macrophage transcriptome and lends weight to a suggested role for estrogen in the immune system, the possible significance of which is discussed.

Effects of progesterone and estradiol sex hormones on the release of microparticles by RAW 264.7 macrophages stimulated by Poly(I:C)

Microparticles (MPs) are small membrane-bound vesicles that display proinflammatory and prothrombotic properties. These particles can be released by macrophages stimulated by ligands of the Toll-like receptors (TLRs) in a process that depends on nitric oxide (NO) production. Since sex hormones can modulate macrophage responses, we investigated the effects of progesterone and estradiol on macrophage particle release in vitro, comparing the responses with those induced by the glucocorticoid dexamethasone. As a model system for particle release, RAW 264.7 cells were stimulated in vitro with poly(I:C), a ligand of TLR3. Microparticles were measured by flow cytometry, while NO was measured by the Griess reaction. As the results of these studies showed, progesterone but not estradiol can block particle release by RAW264.7 cells treated with poly(I:C); dexamethasone was also active. Furthermore, while progesterone and dexamethasone inhibited NO production under the same culture conditions, neither agent blocked the production of particles stimulated by the NO donors dipropylenetriamine NONOate {(z)-1-[N-(3-aminopropyl)-N-(3-ammoniopropyl)amino] diazen-1-ium-1,2-diolate} and (z)-1-[(2-aminoethyl)-N-(2-ammonioethyl)amino] diazen-1-ium-1,2-diolate. Studies using RU486 to assess the role of hormone receptors indicated that while this agent blocked the inhibition of particle and NO production by dexamethasone, it did not affect the inhibition by progesterone. Together, these results indicate that progesterone but not estradiol can inhibit particle release by stimulated macrophages and suggest a mechanism that may contribute to the immunomodulatory effects of this sex hormone.

Role of gender in multiple sclerosis: clinical effects and potential molecular mechanisms

Multiple sclerosis (MS) is more prevalent in females than males, and this female predominance is increasing as time goes by. Additionally, gender appears to play critical roles in development, progression and treatment of MS, and is therefore an aspect that should always be considered in the design and interpretation of research and clinical trials for MS. In this review, factors that could potentially explain the gender-biased observations in MS are discussed. These include sex-specific differences between the male and female immune systems and nervous systems, genetic and epigenetic or environmental-related effects, the effects of gonadal hormones, and materno-fetal interactions.

Role of the estrogen/estrogen-receptor-beta axis in the genomic response to pressure overload-induced hypertrophy

Cardiac hypertrophy, the adaptive response of the heart to overload, is a major risk factor for heart failure and sudden death. Estrogen (E2) and estrogen receptor beta (ERbeta) offer protection against hypertrophy and in the transition to heart failure. However, the underlying pathways remain incompletely defined. We employed a publicly available microarray dataset of female wild-type (WT) and ERbeta knockout (BERKO) mice subjected to pressure overload-induced hypertrophy to perform a systematic investigation of the mechanisms involved in the protection conferred by the E2/ERbeta axis. We show that considerably more genes were modulated in response to pressure overload in BERKO mice than in WT mice. The majority of the identified candidates in BERKO mice were induced, while those in WT mice were repressed. Pathway analysis revealed a similar pattern. This study is the first to demonstrate that the lack of ERbeta led to a significant increase of inflammatory pathways. Mitochondrial bioenergetics- and oxidative stress-related pathways were also modulated. In conclusion, ERbeta acquires the role of gatekeeper of the genomic response of the heart to pressure overload-induced hypertrophy. This may offer the molecular explanation for its cardioprotective role. We consider the present study to be a useful resource and that it will contribute to downstream functional analysis and to the characterization of pathways with previously unknown role in hypertrophy.