The X chromosome and immune associated genes

Sex- or Gender-specific Differences in the Clinical Presentation, Outcome, and Treatment of SARS-CoV-2

This review describes the sex and gender differences in COVID-19 presentation, treatment, and outcomes. We discuss the differences between the sexes in susceptibility to infection, the role of sex chromosomes on the body's immunologic response and the influence of hormones on the body's response to the virus. Additionally, the sex differences in clinical and laboratory presentation, complications of infection and outcomes, as well as differences in response to treatment and prevention are reviewed.

An enhanced level of LAMP-2A participates in CD4+T cell hyperactivity in patients with primary biliary cholangitis

Background

Primary biliary cholangitis (PBC) is an immune-mediated chronic cholestasis, in which T cell homeostasis plays an important role. Lysosomal-associated membrane protein 2 isoform A (LAMP-2A) has been implicated in the regulation of CD4⁺T cell responses.

Methods

We comprehensively evaluated the immunobiology of CD4⁺T cells in patients with PBC (PBC, n=42), chronic hepatitis B (CHB, n=20), and healthy control subjects (HC, n=20) by flow cytometry including activation status and LAMP-2A expression. Additionally, we investigated the activation responses of PBC-naïve CD4⁺T cells by stimulation in vitro and tested the changes caused by deleting the gene encoding LAMP-2A.

Results

Firstly, we found an increased activation status of circulating CD4⁺T cells from PBC patients compared to the HC subjects, and PBC-naïve CD4⁺T cells showed enhanced responses after stimulation in vitro. Secondly, PBC-naïve CD4⁺T cells expressed a significantly higher level of LAMP-2A compared to the HC and CHB groups [PBC vs. HC, 1,954.74 (1,254.28-3,057.14) vs. 1,542.12 (961.18-2,277.98), P=0.03; vs. CHB, 1,153.59 (726.87-1,275.48), P=0.02], and the overreactions of PBC-naïve CD4⁺T cells could be reversed by interfering with LAMP-2A expression in vitro. Thirdly, the LAMP-2A expression level of PBC-naïve CD4⁺T cells was related to disease severity and drug response.

Conclusions

An abnormally increased LAMP-2A expression of PBC-naïve CD4⁺T cells might be related to excessive activation responses. LAMP-2A could be a novel therapeutic target for the treatment of PBC by reversing excessive responses and consequently reducing biliary injury.

Male sex identified by global COVID-19 meta-analysis as a risk factor for death and ITU admission

Anecdotal evidence suggests that Coronavirus disease 2019 (COVID-19), caused by the coronavirus SARS-CoV-2, exhibits differences in morbidity and mortality between sexes. Here, we present a meta-analysis of 3,111,714 reported global cases to demonstrate that, whilst there is no difference in the proportion of males and females with confirmed COVID-19, male patients have almost three times the odds of requiring intensive treatment unit (ITU) admission (OR = 2.84; 95% CI = 2.06, 3.92) and higher odds of death (OR = 1.39; 95% CI = 1.31, 1.47) compared to females. With few exceptions, the sex bias observed in COVID-19 is a worldwide phenomenon. An appreciation of how sex is influencing COVID-19 outcomes will have important implications for clinical management and mitigation strategies for this disease.

Sexual Dimorphism in Colon Cancer

A higher incidence of colorectal cancer (CRC) is found in males compared to females. Young women (18-44 years) with CRC have a better survival outcome compared to men of the same age or compared to older women (over 50 years), indicating a global incidence of sexual dimorphism in CRC rates and survival. This suggests a protective role for the sex steroid hormone estrogen in CRC development. Key proliferative pathways in CRC tumorigenesis exhibit sexual dimorphism, which confer better survival in females through estrogen regulated genes and cell signaling. Estrogen regulates the activity of a class of Kv channels (KCNQ1:KCNE3), which control fundamental ion transport functions of the colon and epithelial mesenchymal transition through bi-directional interactions with the Wnt/β-catenin signalling pathway. Estrogen also modulates CRC proliferative responses in hypoxia via the novel membrane estrogen receptor GPER and HIF1A and VEGF signaling. Here we critically review recent clinical and molecular insights into sexual dimorphism of CRC biology modulated by the tumor microenvironment, estrogen, Wnt/β-catenin signalling, ion channels, and X-linked genes.

Male sex identified by global COVID-19 meta-analysis as a risk factor for death and ITU admission

Anecdotal evidence suggests that Coronavirus disease 2019 (COVID-19), caused by the coronavirus SARS-CoV-2, exhibits differences in morbidity and mortality between sexes. Here, we present a meta-analysis of 3,111,714 reported global cases to demonstrate that, whilst there is no difference in the proportion of males and females with confirmed COVID-19, male patients have almost three times the odds of requiring intensive treatment unit (ITU) admission (OR = 2.84; 95% CI = 2.06, 3.92) and higher odds of death (OR = 1.39; 95% CI = 1.31, 1.47) compared to females. With few exceptions, the sex bias observed in COVID-19 is a worldwide phenomenon. An appreciation of how sex is influencing COVID-19 outcomes will have important implications for clinical management and mitigation strategies for this disease.

Male sex identified by global COVID-19 meta-analysis as a risk factor for death and ITU admission

Anecdotal evidence suggests that Coronavirus disease 2019 (COVID-19), caused by the coronavirus SARS-CoV-2, exhibits differences in morbidity and mortality between sexes. Here, we present a meta-analysis of 3,111,714 reported global cases to demonstrate that, whilst there is no difference in the proportion of males and females with confirmed COVID-19, male patients have almost three times the odds of requiring intensive treatment unit (ITU) admission (OR = 2.84; 95% CI = 2.06, 3.92) and higher odds of death (OR = 1.39; 95% CI = 1.31, 1.47) compared to females. With few exceptions, the sex bias observed in COVID-19 is a worldwide phenomenon. An appreciation of how sex is influencing COVID-19 outcomes will have important implications for clinical management and mitigation strategies for this disease.

Sex differences in neuro(auto)immunity and chronic sciatic nerve pain

Chronic pain occurs with greater frequency in women, with a parallel sexually dimorphic trend reported in sufferers of many autoimmune diseases. There is a need to continue examining neuro-immune-endocrine crosstalk in the context of sexual dimorphisms in chronic pain. Several phenomena in particular need to be further explored. In patients, autoantibodies to neural antigens have been associated with sensory pathway hyper-excitability, and the role of self-antigens released by damaged nerves remains to be defined. In addition, specific immune cells release pro-nociceptive cytokines that directly influence neural firing, while T lymphocytes activated by specific antigens secrete factors that either support nerve repair or exacerbate the damage. Modulating specific immune cell populations could therefore be a means to promote nerve recovery, with sex-specific outcomes. Understanding biological sex differences that maintain, or fail to maintain, neuroimmune homeostasis may inform the selection of sex-specific treatment regimens, improving chronic pain management by rebalancing neuroimmune feedback. Given the significance of interactions between nerves and immune cells in the generation and maintenance of neuropathic pain, this review focuses on sex differences and possible links with persistent autoimmune activity using sciatica as an example.

Vaccinomics and Adversomics in the Era of Precision Medicine: A Review Based on HBV, MMR, HPV, and COVID-19 Vaccines

Precision medicine approaches based on pharmacogenomics are now being successfully implemented to enable physicians to predict more efficient treatments and prevention strategies for a given disease based on the genetic background of the patient. This approach has already been proposed for vaccines, but research is lagging behind the needs of society, and precision medicine is far from being implemented here. While vaccinomics concerns the effectiveness of vaccines, adversomics concerns their side effects. This area has great potential to address public concerns about vaccine safety and to promote increased public confidence, higher vaccination rates, and fewer serious adverse events in genetically predisposed individuals. The aim here is to explore the contemporary scientific literature related to the vaccinomic and adversomic aspects of the three most-controversial vaccines: those against hepatitis B, against measles, mumps, and rubella, and against human Papilloma virus. We provide detailed information on the genes that encode human leukocyte antigen, cytokines and their receptors, and transcription factors and regulators associated with the efficacy and safety of the Hepatitis B and Measles, Mumps and Rubella virus vaccines. We also investigate the future prospects of vaccinomics and adversomics of a COVID-19 vaccine, which might represent the fastest development of a vaccine ever.

Sex-Biased Molecular Signature for Overall Survival of Liver Cancer Patients

Sex/gender disparity has been shown in the incidence and prognosis of many types of diseases, probably due to differences in genes, physiological conditions such as hormones, and lifestyle between the sexes. The mortality and survival rates of many cancers, especially liver cancer, differ between men and women. Due to the pronounced sex/gender disparity, considering sex/gender may be necessary for the diagnosis and treatment of liver cancer. By analyzing research articles through a PubMed literature search, the present review identified 12 genes which showed practical relevance to cancer and sex disparities. Among the 12 sex-specific genes, 7 genes (BAP1, CTNNB1, FOXA1, GSTO1, GSTP1, IL6, and SRPK1) showed sex-biased function in liver cancer. Here we summarized previous findings of cancer molecular signature including our own analysis, and showed that sex-biased molecular signature CTNNB1^High, IL6^High, RHOA^High and GLIPR1^Low may serve as a female-specific index for prediction and evaluation of OS in liver cancer patients. This review suggests a potential implication of sex-biased molecular signature in liver cancer, providing a useful information on diagnosis and prediction of disease progression based on gender.

Sex differences in health and disease: A review of biological sex differences relevant to cancer with a spotlight on glioma

The influence of biological sex differences on human health and disease, while being increasingly recognized, has long been underappreciated and underexplored. While humans of all sexes are more alike than different, there is evidence for sex differences in the most basic aspects of human biology and these differences have consequences for the etiology and pathophysiology of many diseases. In a disease like cancer, these consequences manifest in the sex biases in incidence and outcome of many cancer types. The ability to deliver precise, targeted therapies to complex cancer cases is limited by our current understanding of the underlying sex differences. Gaining a better understanding of the implications and interplay of sex differences in diseases like cancer will thus be informative for clinical practice and biological research. Here we review the evidence for a broad array of biological sex differences in humans and discuss how these differences may relate to observed sex differences in various diseases, including many cancers and specifically glioblastoma. We focus on areas of human biology that play vital roles in healthy and disease states, including metabolism, development, hormones, and the immune system, and emphasize that the intersection of sex differences in these areas should not go overlooked. We further propose that mathematical approaches can be useful for exploring the extent to which sex differences affect disease outcomes and accounting for those in the development of therapeutic strategies.

Massive pericardial effusion and cardiac tamponade revealed undiagnosed Turner syndrome: a case report

Background

Patients with Turner syndrome (TS) are prone to autoimmune disorders. Although most patients with TS are diagnosed at younger ages, delayed diagnosis is not rare.

Case presentation

A 31-year-old woman was presented with facial edema, chest tightness and dyspnea. She had primary amenorrhea. Physical examination revealed short stature, dry skin and coarse hair. Periorbital edema with puffy eyelids were also noticed with mild goiter. Bilateral cardiac enlargement, distant heart sounds and pulsus paradoxus, in combination with hepatomegaly and jugular venous distention were observed. Her hircus and pubic hair was absent. The development of her breast was at 1st tanner period and gynecological examination revealed infantile vulva. Echocardiography suggested massive pericardial effusion. She was diagnosed with cardiac tamponade based on low systolic pressure, decreased pulse pressure and pulsus paradoxus. Pericardiocentesis was performed. Thyroid function test and thyroid ultrasound indicated Hashimoto’s thyroiditis and severe hypothyroidism. Sex hormone test revealed hypergonadotropin hypogonadism. Further karyotyping revealed a karyotype of 45, X [21]/46, X, i(X) (q10) [29] and she was diagnosed with mosaic + variant type of TS. L-T4 supplement, estrogen therapy, and antiosteoporosis treatment was initiated. Euthyroidism and complete resolution of the pericardial effusion was obtained within 2 months.

Conclusion

Hypothyroidism should be considered in the patients with pericardial effusion. The association between autoimmune thyroid diseases and TS should be kept in mind. Both congenital and acquired cardiovascular diseases should be screened in patients with TS.

Epigenetics, pregnancy and autoimmune rheumatic diseases

Autoimmune rheumatic diseases (ARDs) are chronic conditions with a striking female predominance, frequently affecting women of childbearing age. Sex hormones and gender dimorphism of immune response are major determinants in the multifactorial pathogenesis of ARDs, with significant implications throughout reproductive life. Particularly, pregnancy represents a challenging condition in the context of autoimmunity, baring profound hormonal and immunologic changes, which are responsible for the bi-directional interaction between ARDs outcome and pregnancy course. In the latest years epigenetics has proven to be an important player in ARDs pathogenesis, finely modulating major immune functions and variably tuning the significant gender effects in autoimmunity. Additionally, epigenetics is a recognised influencer of the physiological dynamic modifications occurring during pregnancy. Still, there is currently little evidence on the pregnancy-related epigenetic modulation of immune response in ARDs patients. This review aims to overview the current knowledge of the role of epigenetics in the context of autoimmunity, as well as during physiologic and pathologic pregnancy, discussing under-regarded aspects in the interplay between ARDs and pregnancy pathology. The outline of a new ongoing European project will be presented.

Gender differences in COVID-19 attitudes and behavior: Panel evidence from eight countries

The initial public health response to the breakout of COVID-19 required fundamental changes in individual behavior, such as isolation at home or wearing masks. The effectiveness of these policies hinges on generalized public obedience. Yet, people's level of compliance may depend on their beliefs regarding the pandemic. We use original data from two waves of a survey conducted in March and April 2020 in eight Organisation for Economic Co-operation and Development countries (n = 21,649) to study gender differences in COVID-19-related beliefs and behaviors. We show that women are more likely to perceive COVID-19 as a very serious health problem, to agree with restraining public policy measures, and to comply with them. Gender differences in attitudes and behavior are sizable in all countries. They are accounted for neither by sociodemographic and employment characteristics nor by psychological and behavioral factors. They are only partially mitigated for individuals who cohabit or have direct exposure to the virus. We show that our results are not due to differential social desirability bias. This evidence has important implications for public health policies and communication on COVID-19, which may need to be gender based, and it unveils a domain of gender differences: behavioral changes in response to a new risk.

Time to get ill: the intersection of viral infections, sex, and the X chromosome

Females have more robust immune responses than males, and viral infections are more severe for males. Hormones and genetic sex, namely the X chromosome, influence sex differences with immune responses. Here, we review recent findings underlying sexual dimorphism of disease susceptibility for two prevalent viral infections, influenza and SARS-CoV-2, which exhibit male-biased disease severity. Viral infections are proposed to be an initiating event for autoimmunity, which exhibits a female bias. We also review recent work elucidating the epigenetic and genetic contribution of X-Chromosome Inactivation maintenance, and X-linked gene expression, for the autoimmune disorder Systemic Lupus Erythematosus, and highlight the complex considerations required for identifying underlying hormonal and genetic contributions responsible for sex differences in immune responses.

What microRNAs could tell us about the human X chromosome

MicroRNAs (miRNA) are small-non coding RNAs endowed with great regulatory power, thus playing key roles not only in almost all physiological pathways, but also in the pathogenesis of several diseases. Surprisingly, genomic distribution analysis revealed the highest density of miRNA sequences on the X chromosome; this evolutionary conserved mammalian feature equips females with a larger miRNA machinery than males. However, miRNAs contribution to some X-related conditions, properties or functions is still poorly explored. With the aim to support and focus research in the field, this review analyzes the literature and databases about X-linked miRNAs, trying to understand how miRNAs could contribute to emerging gender-biased functions and pathological mechanisms, such as immunity and cancer. A fine map of miRNA sequences on the X chromosome is reported, and their known functions are discussed; in addition, bioinformatics functional analyses of the whole X-linked miRNA targetome (predicted and validated) were performed. The emerging scenario points to different gaps in the knowledge that should be filled with future experimental investigations, also in terms of possible implications and pathological perspectives for X chromosome aneuploidy syndromes, such as Turner and Klinefelter syndromes.

Could Estrogen Protect Women From COVID-19?

The apparent gender differences in favor of women in the risk of contracting and dying from coronavirus disease 2019 (COVID-19), and the fact that such trends have also been observed in recent epidemics including severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS), have prompted the obvious question: Are the reasons life-style or biological? True, women generally make healthier lifestyle choices as compared to men. Women do not smoke or drink as much as men, and they have a lower burden of those diseases (heart disease, diabetes or chronic lung conditions) that are known to be significant factors in the higher death rates among men with COVID-19. But there is compelling evidence for a role for biological factors. Genes are likely to play an important role. The X chromosome, of which women possess two, contains the largest number of immune-related genes of the whole human genome, theoretically giving women double the advantage over men in mounting an efficient and rapid immune response. A fundamental difference between women and men is their hormonal milieu, and it is not unreasonable to suppose that the dominant female hormone estrogen could influence the response to infection. In this paper we evaluate the evidence and mechanisms by which estrogen could provide protection to women from a variety of viruses, perhaps including the coronavirus that causes COVID-19.

Autoimmunity as the comet tail of COVID-19 pandemic

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can give rise to different clinical manifestations that are directly related to viral tissue damage or indirectly induced by the antiviral immune response. Hyper-activation of the immune system in an attempt to eradicate the infection may trigger autoimmunity. Several immune-mediated disorders have been described in SARS-CoV-2-infected individuals. These include cutaneous rashes and vasculitis, autoimmune cytopenia, anti-phospholipid syndrome, central or peripheral neuropathy, myositis and myocarditis. On the other hand, rheumatic patients were reported to have similar coronavirus disease 2019 (COVID-19) incidence, morbidity and mortality rates compared to general population. This opinion review will summarize the crucial immunologic steps which occur during SARS-CoV-2-infection that may link autoimmunity to COVID-19 and provides an opportunity for further discussion regarding this association.

The Effects of Androgens on T Cells: Clues to Female Predominance in Autoimmune Liver Diseases?

The immune system responds differently in women and in men. Generally speaking, adult females show stronger innate and adaptive immune responses than males. This results in lower risk of developing most of the infectious diseases and a better ability to clear viral infection in women (1–5). On the other hand, women are at increased risk of developing autoimmune diseases (AID) such as rheumatoid arthritis, multiple sclerosis (MS), systemic lupus erythematosus (SLE), Sjögren's syndrome, and the autoimmune liver diseases autoimmune hepatitis (AIH) and primary biliary cholangitis (PBC) (6). Factors contributing to the female sex bias in autoimmune diseases include environmental exposure, e.g., microbiome, behavior, and genetics including X chromosomal inactivation of genes. Several lines of evidence and clinical observations clearly indicate that sex hormones contribute significantly to disease pathogenesis, and the role of estrogen in autoimmune diseases has been extensively studied. In many of these diseases, including the autoimmune liver diseases, T cells are thought to play an important pathogenetic role. We will use this mini-review to focus on the effects of androgens on T cells and how the two major androgens, testosterone and dihydrotestosterone, potentially contribute to the pathogenesis of autoimmune liver diseases (AILD).

Gender differences in anaphylaxis

PURPOSE OF REVIEW

Is sexual dimorphism also true in anaphylaxis as described in other allergic diseases? Possible gender differences in the epidemiology, triggers, severity, outcomes of anaphylaxis as well as in the pathogenesis of the disease are discussed.

RECENT FINDINGS

Hormonal status and the X-chromosome-coded factors deeply involved in the regulation of T-cell and B-cell responses may influence the gender difference noticed in allergic diseases, such as asthma and rhinitis. Little is known if sex is also relevant for anaphylaxis, although the description of catamenial anaphylaxis is intriguing. However, epidemiologic bias, lack of reliable animal models for the human disease, differences into diagnostic codes and not harmonized clinical grading unfortunately represent hurdles to obtain meaningful information on this topic.

SUMMARY

The female sex predisposes to a dysregulation of the immune response as suggested by the increased prevalence of autoimmunity and atopy. In anaphylaxis, pathomechanisms are not fully disclosed, triggers are numerous and IgE-dependent mast cell degranulation only represents a part of the story. Improvement into the definition of the disease including a more careful coding system and better investigations about triggers seem the only way to allow a more precise assessment of the possible different risk for women to develop anaphylaxis.

SeXX Matters in Multiple Sclerosis

Multiple sclerosis (MS) is the most common chronic inflammatory and neurodegenerative disease of the central nervous system (CNS). An interesting feature that this debilitating disease shares with many other inflammatory disorders is that susceptibility is higher in females than in males, with the risk of MS being three times higher in women compared to men. Nonetheless, while men have a decreased risk of developing MS, many studies suggest that males have a worse clinical outcome. MS exhibits an apparent sexual dimorphism in both the immune response and the pathophysiology of the CNS damage, ultimately affecting disease susceptibility and progression differently. Overall, women are predisposed to higher rates of inflammatory relapses than men, but men are more likely to manifest signs of disease progression and worse CNS damage. The observed sexual dimorphism in MS may be due to sex hormones and sex chromosomes, acting in parallel or combination. In this review, we outline current knowledge on the sexual dimorphism in MS and discuss the interplay of sex chromosomes, sex hormones, and the immune system in driving MS disease susceptibility and progression.

The Role of Genetic Sex and Mitochondria in Response to COVID-19 Infection

The difference between the female and male immune response to COVID-19 infection, and infections in general, is multifactorial. The well-known determiners of the immune response, such as X and Y chromosomes, sex hormones, and microbiota, are functionally interconnected and influence each other in shaping the organism's immunity. We focus our commentary on the interplay between the genetic sex and mitochondria and how this may affect a sex-dependent immune response in COVID-19 infection. Realizing the existence of these interactions may help in designing novel methods or fine-tuning the existing and routine therapies to fight COVID-19 and other infections.

Microbiota and Lifestyle: A Special Focus on Diet

It is widely known that a good balance and healthy function for bacteria groups in the colon are necessary to maintain homeostasis and preserve health. However, the lack of consensus on what defines a healthy gut microbiota and the multitude of factors that influence human gut microbiota composition complicate the development of appropriate dietary recommendations for our gut microbiota. Furthermore, the varied response to the intake of probiotics and prebiotics observed in healthy adults suggests the existence of potential inter- and intra-individual factors, which might account for gut microbiota changes to a greater extent than diet. The changing dietary habits worldwide involving consumption of processed foods containing artificial ingredients, such as sweeteners; the coincident rise in emotional disorders; and the worsening of other lifestyle habits, such as smoking habits, drug consumption, and sleep, can together contribute to gut dysbiosis and health impairment, as well as the development of chronic diseases. This review summarizes the current literature on the effects of specific dietary ingredients (probiotics, prebiotics, alcohol, refined sugars and sweeteners, fats) in the gut microbiota of healthy adults and the potential inter- and intra-individual factors involved, as well as the influence of other potential lifestyle factors that are dramatically increasing nowadays.

Cardiovascular Complications in Patients with Turner's Syndrome

Turner's or Turner syndrome (TS) is the most prevalent chromosomal abnormality in live female births. Patients with TS are predisposed to an increased risk of cardiovascular diseases (CVD), mainly due to the frequently observed congenital structural cardiovascular defects, such as valvular and aortic abnormalities (coarctation, dilatation, and dissection). The increased prevalence of cardiometabolic risk factors, such as arterial hypertension, insulin resistance, diabetes mellitus, dyslipidaemia, central obesity, and increased carotid intima-media thickness, also contribute to increased morbidity and mortality in TS patients. Menopausal hormone therapy (MHT) is the treatment of choice, combined with growth hormone (GH). Although MHT may, in general, ameliorate CVD risk factors, its effect on CVD mortality in TS has not yet been established. The exact effect of GH on these parameters has not been clarified. Specific considerations should be provided in TS cases during pregnancy, due to the higher risk of CVD complications, such as aortic dissection. Optimal cardiovascular monitoring, including physical examination, electrocardiogram, CVD risk factor assessment, and transthoracic echocardiography, is recommended. Moreover, the cardiac magnetic resonance from the age of 12 years is recommended due to the high risk of aortic aneurysm and other anatomical vascular complications.

The lethal sex gap: COVID-19

While Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is disrupting lives across the globe for everyone, it has a more devastating impact on the health of older adults, especially that of older men. This pandemic has highlighted the crucial importance of considering an individual’s age and biological sex in the clinic in addition to other confounding diseases (Kuchel, G.A, J Am Geriatr Soc, 67, 203, 2019, Tannenbaum, C., Nature, 575 451-458, 2009) As an interdisciplinary team of scientists in immunology, hematology, genomics, bioinformatics, and geriatrics, we have been studying how age and sex shape the human immune system. Herein we reflect on how our recent findings on the alterations of the immune system in aging might contribute to our current understanding of COVID-19 infection rate and disease risk.

Malignant pleural effusion survival prognostication in an Asian population

BACKGROUND AND OBJECTIVE

LENT and PROMISE scores prognosticate survival in patients with MPE. Prognostication guides the selection of interventions and management. However, the predictive value of these scores and their refinements (modified-LENT) in Asians remain unclear. We aim to evaluate the performance of LENT, modified-LENT and clinical PROMISE scores; identify predictors of survival; and develop an alternative prognostication tool should current scores lack accuracy.

METHODS

Retrospective medical record review of an Asian pleuroscopy database from 2011 to 2018 of patients with MPE was conducted. The prognostic capability of current available scores were evaluated using C-statistics. Demographic and clinical variables as predictors of survival were assessed, and an alternative model was developed using logistic regression.

RESULTS

In 130 patients, the C-statistics for modified-LENT was not significantly different from LENT (0.59 (95% CI: 0.52-0.67) vs 0.56 (95% CI: 0.49-0.63); P = 0.403). In 57 patients, the PROMISE C-statistics was 0.72 (95% CI: 0.53-0.91). In our alternative prognostication model (n = 147), Sex, Eastern Cooperative Oncology Group status, Leukocyte count, EGFR mutation, Chemotherapy and primary Tumour type (SELECT) were predictors of 90-day mortality (C-statistic = 0.87 (95% CI: 0.79-0.95)). SELECT sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios using a predicted probability of 90-day mortality cut-off point of 10% were 0.91, 0.68, 0.34, 0.98, 2.83 and 0.13, respectively.

CONCLUSION

The LENT, modified-LENT and PROMISE scores have poor accuracy of survival prognostication in Asian patients with MPE undergoing pleuroscopy. The proposed SELECT prognostication model is accurate at identifying patients with high probability of survival at 90 days.

A new view of sexual differentiation of mammalian brain

Establishment of enduring sex differences in brain and behavior occurs during pre- or perinatal development, depending on species. For over 50 years the focus has been on gonadal steroid production by male fetuses and the impact on developing brain. An increasing awareness of the importance of sex chromosome complement has broadened the focus but identifying specific roles in development has yet to be achieved. Recent emphasis on transcriptomics has revealed myriad and unexpected differences in gene expression in specific regions of male and female brains which may produce sex differences, serve a compensatory role or provide latent sex differences revealed only in response to challenge. More surprising, however, has been the consistent observation of a central role for inflammatory signaling molecules and immune cells in masculinization of brain and behavior. The signal transduction pathways and specific immune cells vary by brain region, as does the neuroanatomical substrate subject to differentiation, reflecting substantial complexity emerging from what may be a common origin, the maternal immune system. A working hypothesis integrating these various ideas is proposed.

Xist attenuates acute inflammatory response by female cells

Biological sex influences inflammatory response, as there is a greater incidence of acute inflammation in men and chronic inflammation in women. Here, we report that acute inflammation is attenuated by X-inactive specific transcript (Xist), a female cell-specific nuclear long noncoding RNA crucial for X-chromosome inactivation. Lipopolysaccharide-mediated acute inflammation increased Xist levels in the cytoplasm of female mouse J774A.1 macrophages and human AML193 monocytes. In both cell types, cytoplasmic Xist colocalizes with the p65 subunit of NF-κB. This interaction was associated with reduced NF-κB nuclear migration, suggesting a novel mechanism to suppress acute inflammation. Further supporting this hypothesis, expression of 5' XIST in male cells significantly reduced IL-6 and NF-κB activity. Adoptive transfer of male splenocytes expressing Xist reduced acute paw swelling in male mice indicating that Xist can have a protective anti-inflammatory effect. These findings show that XIST has functions beyond X chromosome inactivation and suggest that XIST can contribute to sex-specific differences underlying inflammatory response by attenuating acute inflammation in women.

Immune System Sex Differences May Bridge the Gap Between Sex and Gender in Fibromyalgia

The fibromyalgia syndrome (FMS) is characterized by chronic widespread pain, sleep disturbances, fatigue, and cognitive alterations. A limited efficacy of targeted treatment and a high FMS prevalence (2–5% of the adult population) sums up to high morbidity. Although, altered nociception has been explained with the central sensitization hypothesis, which may occur after neuropathy, its molecular mechanism is not understood. The marked female predominance among FMS patients is often attributed to a psychosocial predisposition of the female gender, but here we will focus on sex differences in neurobiological processes, specifically those of the immune system, as various immunological biomarkers are altered in FMS. The activation of innate immune sensors is compatible with a neuropathy or virus-induced autoimmune diseases. Considering sex differences in the immune system and the clustering of FMS with autoimmune diseases, we hypothesize that the female predominance in FMS is due to a neuropathy-induced autoimmune pathophysiology. We invite the scientific community to verify the autoimmune hypothesis for FMS.

SeXY chromosomes and the immune system: reflections after a comparative study

Background

Sex bias in immune function has been contributed in part to a preponderance of immune system-related genes (ISRG) on the X-chromosome. We verified whether ISRG are more abundant on the X chromosome as compared to autosomal chromosomes and reflected on the impact of our findings.

Methods

Consulting freely accessible databases, we performed a comparative study consisting of three complementary strategies. First, among coding X/Y-linked genes, the abundance of ISRG was compared to the abundance of genes dedicated to other systems. Genes were assigned considering three criteria: disease, tissue expression, and function (DEF approach). In addition, we carried out two genome-wide approaches to compare the contribution of sex and autosomal chromosomes to immune genes defined by an elevated expression in lymphatic tissues (LTEEG approach) or annotation to an immune system process, GO:0002376 (GO approach).

Results

The X chromosome had less immune genes than the median of the autosomal chromosomes. Among X-linked genes, ISRG ranked fourth after the reproductive and nervous systems and genes dedicated to development, proliferation and apoptosis. On the Y chromosome, ISRG ranked second, and at the pseudoautosomal region (PAR) first. According to studies on the expression of X-linked genes in a variety of (mostly non-lymphatic) tissues, almost two-thirds of ISRG are expressed without sex bias, and the remaining ISRG presented female and male bias with similar frequency. Various epigenetic controllers, X-linked MSL3 and Y-linked KDM5D and UTY, were preferentially expressed in leukocytes and deserve further attention for a possible role in sex biased expression or its neutralisation.

Conclusions

The X chromosome is not enriched for ISRG, though particular X-linked genes may be responsible for sex differences in certain immune responses. So far, there is insufficient information on sex-biased expression of X/Y-linked ISRG in leukocytes to draw general conclusions on the impact of X/Y-linked ISRG in immune function. More research on the regulation of the expression X-linked genes is required with attention to 1) female and male mechanisms that may either augment or diminish sex biased expression and 2) tissue-specific expression studies.

Prevalence of Celiac Disease in Patients with Primary Biliary Cholangitis

Background

Primary biliary cholangitis (PBC) frequently coexists with other autoimmune diseases, including celiac disease (CeD). Although the prevalence of CeD is high among cohorts with PBC, few studies have directly compared this prevalence to those among individuals with other liver diseases (OLD).

Aim

To compare the prevalence of CeD between a cohort with PBC and a cohort with OLD.

Methods

Retrospective study from January 2013 to December 2016. All consecutive patients with an anti-transglutaminase (tTG) assay requested by a hepatologist and a diagnosis of chronic liver disease were included. CeD diagnosis was confirmed by duodenal biopsies.

Results

We included 399 consecutive patients (53.1 years SD 14.0, 54.1% women), notably 51 individuals with PBC and 348 individuals with OLD. PBC group included significantly more women (90.2% versus 48.9% P < 0.0001). The prevalence of CeD was higher in the group with PBC compared to the group with OLD (11.8 versus 2.9%, P < 0.003). In the OLD group, the prevalence of CeD was comparable regardless of the etiologic subgroup (nonalcoholic steatohepatitis 2.7% versus alcoholic liver disease 4.3%, versus viral 1.5% versus other autoimmune liver diseases 3.3%, NS). The presence of gastrointestinal symptoms at the time of the tTG assay was comparable between PBC and OLD groups (31.4 versus 29.6%, NS).

Conclusion

There is a higher prevalence of CeD in the PBC group compared to other liver diseases.

Bioinformatic Analysis Identifies Potential Key Genes in the Pathogenesis of Turner Syndrome

Background: Turner syndrome (TS) is a sex chromosome aneuploidy with a variable spectrum of symptoms including short stature, ovarian failure and skeletal abnormalities. The etiology of TS is complex, and the mechanisms driving its pathogenesis remain unclear. Methods: In our study, we used the online Gene Expression Omnibus (GEO) microarray expression profiling dataset GSE46687 to identify differentially expressed genes (DEGs) between monosomy X TS patients and normal female individuals. The relevant data on 26 subjects with TS (45,XO) and 10 subjects with the normal karyotype (46,XX) was investigated. Then, tissue-specific gene expression, functional enrichment, and protein-protein interaction (PPI) network analyses were performed, and the key modules were identified. Results: In total, 25 upregulated and 60 downregulated genes were identified in the differential expression analysis. The tissue-specific gene expression analysis of the DEGs revealed that the system with the most highly enriched tissue-specific gene expression was the hematologic/immune system, followed by the skin/skeletal muscle and neurologic systems. The PPI network analysis, construction of key modules and manual screening of tissue-specific gene expression resulted in the identification of the following five genes of interest: CD99, CSF2RA, MYL9, MYLPF, and IGFBP2. CD99 and CSF2RA are involved in the hematologic/immune system, MYL9 and MYLPF are related to the circulatory system, and IGFBP2 is related to skeletal abnormalities. In addition, several genes of interest with possible roles in the pathogenesis of TS were identified as being associated with the hematologic/immune system or metabolism. Conclusion: This discovery-driven analysis may be a useful method for elucidating novel mechanisms underlying TS. However, more experiments are needed to further explore the relationships between these genes and TS in the future.

Association of LAG3 genetic variation with an increased risk of PD in Chinese female population

BACKGROUND

Emerging evidence suggests that α-synuclein (α-syn) aggregation and intercellular transmission contributes to pathogenesis of Parkinson's disease (PD) and the toxic fibrillary α-syn binds lymphocyte-activation gene 3 (LAG3) receptor that mediates α-syn transmission. The deletion of LAG3 in animal models was shown to limit α-syn spreading and alleviate the pathological changes of dopaminergic neurons and animal behavioral deficits induced by α-syn aggregation. However, little is known about the genetic association of LAG3 variation with human PD development.

OBJECTIVE

Here we investigated LAG3 single nucleotide polymorphisms (SNPs) and examined the levels of soluble LAG3 (sLAG3) of CSF and serum from Chinese PD patients.

METHODS

We enrolled 646 PD patients and 536 healthy controls to conduct a case-control study. All the participants were genotyped using Sequenom iPLEX Assay and the partial cerebrospinal fluid (CSF) and serum samples were assessed by Meso Scale Discovery electrochemiluminescence (MSD-ECL) immunoassay to measure sLAG3 concentration.

RESULTS

As a result, distributions of rs1922452-AA (1.975, 95% confidence interval (CI) 1.311-2.888, p = 0.001) and rs951818-CC (OR = 2.03, 95% CI 1.369-3.010, p = 0.001) genotype frequencies were found higher in the female PD patients than controls, respectively, and a strong linkage disequilibrium (LD) was calculated on the variants. The level of sLAG3 in CSF of PD patients was found to significantly differ from that of controls (51.56 ± 15.05 pg/ml vs 88.49 ± 62.96 pg/ml, p < 0.0001). Meanwhile, the concentration of α-synuclein in CSF of patients was significantly lower than that of controls (939.9 ± 2900 pg/ml vs 2476 ± 4403 pg/ml, p < 0.0001) and the level of sLAG3 was detected to be positive correlation with that of α-synuclein in the control group (r = 0.597, p = 0.0042), but not in PD group (r = 0.111, p = 0.408).

CONCLUSION

In summary, our data suggested that LAG3 SNPs increase the PD risk of Chinese female population and the sLAG3 may be a potential biomarker predicted for PD development.

Parent-of-origin differences in DNA methylation of X chromosome genes in T lymphocytes

Sex differences are naturally occurring disease modifiers that, if understood, could lead to novel targets for drug development. Autoimmune diseases are more prevalent in women than in men, and sex differences in immune responses have been shown in humans and mice. Here, we discover a global parent-of-origin difference in DNA methylation on the X chromosome that affects gene expression in activated CD4⁺ T lymphocytes. The paternal X has more methylation than the maternal X, with higher expression of X genes in XY cells since they only express from the maternal X. Thus, parent-of-origin differences in DNA methylation of X genes can play a role in sex differences in immune responses.

Many autoimmune diseases are more frequent in females than in males in humans and their mouse models, and sex differences in immune responses have been shown. Despite extensive studies of sex hormones, mechanisms underlying these sex differences remain unclear. Here, we focused on sex chromosomes using the “four core genotypes” model in C57BL/6 mice and discovered that the transcriptomes of both autoantigen and anti-CD3/CD28 stimulated CD4⁺ T lymphocytes showed higher expression of a cluster of 5 X genes when derived from XY as compared to XX mice. We next determined if higher expression of an X gene in XY compared to XX could be due to parent-of-origin differences in DNA methylation of the X chromosome. We found a global increase in DNA methylation on the X chromosome of paternal as compared to maternal origin. Since DNA methylation usually suppresses gene expression, this result was consistent with higher expression of X genes in XY cells because XY cells always express from the maternal X chromosome. In addition, gene expression analysis of F1 hybrid mice from CAST × FVB reciprocal crosses showed preferential gene expression from the maternal X compared to paternal X chromosome, revealing that these parent-of-origin effects are not strain-specific. SJL mice also showed a parent-of-origin effect on DNA methylation and X gene expression; however, which X genes were affected differed from those in C57BL/6. Together, this demonstrates how parent-of-origin differences in DNA methylation of the X chromosome can lead to sex differences in gene expression during immune responses.

Nonendocrine mechanisms of sex bias in rheumatic diseases

Rheumatic diseases affect a wide range of individuals of all ages, but the most common diseases occur more frequently in women than in men, at ratios of up to ten women to one man. Despite a growing number of studies on sex bias in rheumatic diseases, sex-specific health care is limited and sex specificity is not systematically integrated into treatment regimens. Women and men differ in three major biological points: the number of X chromosomes per cell, the type and quantities of sex hormones present and the ability to be pregnant, all of which have immunological consequences. Could a greater understanding of these differences lead to a new era of personalized sex-specific medicine? This Review focuses on the main genetic and epigenetic mechanisms that have been put forward to explain sex bias in rheumatic diseases, including X chromosome inactivation, sex chromosome aneuploidy and microchimerism. The influence of sex hormones is not discussed in detail in this Review, as it has been well described elsewhere. Understanding the sex-specific factors that contribute to the initiation and progression of rheumatic diseases will enable progress to be made in the diagnosis, treatment and management of all patients with these conditions.

When the balance is broken: X-linked gene dosage from two X chromosomes and female-biased autoimmunity

Women and men exhibit differences in innate and adaptive immunity, and women are more susceptible to numerous autoimmune disorders. Two or more X chromosomes increases the risk for some autoimmune diseases, and increased expression of some X-linked immune genes is frequently observed in female lymphocytes from autoimmune patients. Evidence from mouse models of autoimmunity also supports the idea that increased expression of X-linked genes is a feature of female-biased autoimmunity. Recent studies have begun to elucidate the correlation between abnormal X-chromosome inactivation (XCI), an essential mechanism female somatic cells use to equalize X-linked gene dosage between the sexes, and autoimmunity in lymphocytes. In this review, we highlight research describing overexpression of X-linked immunity-related genes and female-biased autoimmunity in both humans and mouse models, and make connections with our recent work elucidating lymphocyte-specific mechanisms of XCI maintenance that become altered in lupus patients.

Sex and autoimmune disease: Four mechanisms pointing at women

The ultimate goal of modern medicine is a personalized approach being tailored on the single patient, ie, tailored, based on a finely tuned definition of the immunogenetics, epigenetics, microbiome, and biomarkers, to maximize results and minimize risks particularly of new targeted treatments. Among individual factors around which to tailor the patient management are sex and age, with gender-medicine finally becoming central to the research agenda. Of note, we are not convinced that a whole personalized medicine approach in its current form will necessarily include gender medicine and thus this should remain central to the research agenda. To tackle this crucial issue, however, we should first be able to answer a question of paramount importance, that is, why does autoimmunity affect women more than men? The growing number of experimental works in this area militate against an easy answer to this question, but we will herein briefly discuss four major candidates (sex hormones, sex chromosomes, environmental factors, and the microbiome) to which some unsuspected others may be ancillary.

Mosaicism of XX and XXY cells accounts for high copy number of Toll like Receptor 7 and 8 genes in peripheral blood of men with Rheumatoid Arthritis

The X chromosome, hemizygous in males, contains numerous genes important to immunological and hormonal function. Alterations in X-linked gene dosage are suspected to contribute to female predominance in autoimmunity. A powerful example of X-linked dosage involvement comes from the BXSB murine lupus model, where the duplication of the X-linked Toll-Like Receptor 7 (Tlr7) gene aggravates autoimmunity in male mice. Such alterations are possible in men with autoimmune diseases. Here we showed that a quarter to a third of men with rheumatoid arthritis (RA) had significantly increased copy numbers (CN) of TLR7 gene and its paralog TLR8. Patients with high CN had an upregulated pro-inflammatory JNK/p38 signaling pathway. By fluorescence in situ hybridization, we further demonstrated that the increase in X-linked genes CN was due to the presence of an extra X chromosome in some cells. Men with RA had a significant cellular mosaicism of female (46,XX) and/or Klinefelter (47,XXY) cells among male (46,XY) cells, reaching up to 1.4% in peripheral blood. Our results present a new potential trigger for RA in men and opens a new field of investigation particularly relevant for gender-biased autoimmune diseases.

Gender differences in innate responses and gene expression profiles in memory CD4 T cells are apparent very early during acute simian immunodeficiency virus infection

Gender differences in Human immunodeficiency virus (HIV) disease progression and comorbidities have been extensively reported. Using the simian immunodeficiency virus (SIV) infected rhesus macaque model, we show that these differences are apparent very early during the course of infection. Though there were no major changes in the proportions of CD4 T cells or its subsets, central memory CD4 T cells from female macaques were found to differentially regulate a significantly larger number of genes at day 4 post-infection (PI) as compared to males. Pathway analysis revealed divergence of both canonical and biological pathways that persisted at day 10 PI. Changes in gene expression profiles were accompanied by a significant increase in plasma levels of pro-inflammatory mediators such as MCP-1/CCL2, I-TAC/CXCL11, and MIF. Though plasma levels of IFNα did not differ between male and female macaques, the expression levels of IFNα subtype-14, 16, IFNβ, and IFNω were significantly upregulated in the lymph nodes of female macaques at day 10 PI as compared to male macaques. Our results suggest that the pathogenic sequelae seen during chronic infection may be shaped by gender differences in immune responses induced very early during the course of HIV infection.

Autoimmune diseases in Turner syndrome: an overview

Turner syndrome (TS) results from a sex-chromosomal anomaly characterized by presence of one normal X chromosome and the loss of the second X-chromosome in phenotypic females. Autoimmunity has been recognized as one of the more prominent characteristics of TS. The risk of autoimmune diseases in patients with TS is approximately twice as high as in the general female population. The spectrum includes, Hashimoto’s thyroiditis, coeliac disease (CD), type 1 diabetes (T1DM), alopecia areata, inflammatory bowel disease, juvenile rheumatoid arthritis and some cutaneous disorders as vitiligo and Halo nevus. This review will address the autoimmune disorders associated with TS, their pathophysiologic mechanisms and clinical characteristics. (www.actabiomedica.it)

Recent Advances in Understanding the Reversal of Gene Silencing During X Chromosome Reactivation

Dosage compensation between XX female and XY male cells is achieved by a process known as X chromosome inactivation (XCI) in mammals. XCI is initiated early during development in female cells and is subsequently stably maintained in most somatic cells. Despite its stability, the robust transcriptional silencing of XCI is reversible, in the embryo and also in a number of reprogramming settings. Although XCI has been intensively studied, the dynamics, factors, and mechanisms of X chromosome reactivation (XCR) remain largely unknown. In this review, we discuss how new sequencing technologies and reprogramming approaches have enabled recent advances that revealed the timing of transcriptional activation during XCR. We also discuss the factors and chromatin features that might be important to understand the dynamics and mechanisms of the erasure of transcriptional gene silencing on the inactive X chromosome (Xi).

Genes known to escape X chromosome inactivation predict co-morbid chronic musculoskeletal pain and posttraumatic stress symptom development in women following trauma exposure

Co-morbid chronic musculoskeletal pain (CMSP) and posttraumatic stress symptoms (PTSS) are frequent sequelae of motor vehicle collision, are associated with greater disability than either outcome alone, and are more prevalent in women than men. In the current study we assessed for evidence that gene transcripts originating from the X chromosome contribute to sex differences in vulnerability to CMSP and PTSS after motor vehicle collision. Nested samples were drawn from a longitudinal study of African American individuals, and CMSP (0-10 numeric rating scale) and PTSS (impact of events scale, revised) outcomes were assessed 6 months following motor vehicle collision. Blood RNA were sequenced (n = 101) and the relationship between X chromosome mRNA expression levels and co-morbid CMSP and PTSS outcomes was evaluated using logistic regression analyses. A disproportionate number of peritraumatic X chromosome mRNA predicting CMSP and PTSS in women were genes previously found to escape X chromosome inactivation (11/40, z = -2.9, p = .004). Secondary analyses assessing gene ontology relationships between these genes identified an enrichment in genes known to influence neuronal plasticity. Further, the relationship of expression of two critical regulators of X chromosome inactivation, X-inactive specific transcript (XIST) and Yin Yang 1 (YY1), was different in women developing CMSP and PTSS. Together, these data suggest that X chromosome genes that escape inactivation may contribute to sex differences in vulnerability to CMSP and PTSS after motor vehicle collision.

Drug-induced liver injury

Drug-induced liver injury (DILI) is an adverse reaction to drugs or other xenobiotics that occurs either as a predictable event when an individual is exposed to toxic doses of some compounds or as an unpredictable event with many drugs in common use. Drugs can be harmful to the liver in susceptible individuals owing to genetic and environmental risk factors. These risk factors modify hepatic metabolism and excretion of the DILI-causative agent leading to cellular stress, cell death, activation of an adaptive immune response and a failure to adapt, with progression to overt liver injury. Idiosyncratic DILI is a relative rare hepatic disorder but can be severe and, in some cases, fatal, presenting with a variety of phenotypes, which mimic other hepatic diseases. The diagnosis of DILI relies on the exclusion of other aetiologies of liver disease as specific biomarkers are still lacking. Clinical scales such as CIOMS/RUCAM can support the diagnostic process but need refinement. A number of clinical variables, validated in prospective cohorts, can be used to predict a more severe DILI outcome. Although no pharmacological therapy has been adequately tested in randomized clinical trials, corticosteroids can be useful, particularly in the emergent form of DILI related to immune-checkpoint inhibitors in patients with cancer.

The X-linked histone demethylase Kdm6a in CD4+ T lymphocytes modulates autoimmunity

Multiple sclerosis (MS) is a putative T cell-mediated autoimmune disease. As with many autoimmune diseases, females are more susceptible than males. Sexual dimorphisms may be due to differences in sex hormones, sex chromosomes, or both. Regarding sex chromosome genes, a small percentage of X chromosome genes escape X inactivation and have higher expression in females (XX) compared with males (XY). Here, high-throughput gene expression analysis in CD4+ T cells showed that the top sexually dimorphic gene was Kdm6a, a histone demethylase on the X chromosome. There was higher expression of Kdm6a in females compared with males in humans and mice, and the four core genotypes (FCG) mouse model showed higher expression in XX compared with XY. Deletion of Kdm6a in CD4+ T cells ameliorated clinical disease and reduced neuropathology in the classic CD4+ T cell-mediated autoimmune disease experimental autoimmune encephalomyelitis (EAE). Global transcriptome analysis in CD4+ T cells from EAE mice with a specific deletion of Kdm6a showed upregulation of Th2 and Th1 activation pathways and downregulation of neuroinflammation signaling pathways. Together, these data demonstrate that the X escapee Kdm6a regulates multiple immune response genes, providing a mechanism for sex differences in autoimmune disease susceptibility.

The impact of sex and age on T cell immunity and ischemic stroke outcomes

Sex differences are well-recognized in ischemic stroke, a disease mainly affecting the elderly. Stroke results in robust activation of central and peripheral immune responses which contributes to functional outcome. Aging is associated with increased low-grade chronic inflammation known as "inflammaging" that renders aged males and females more susceptible to poor outcomes after ischemic stroke. Despite the fact that sex differences are well-documented in immunity and inflammation, few studies have focused on sex differences in inflammatory responses after ischemic stroke and even fewer have been performed in the context of aging. The role of T cell responses in ischemic stroke have gained increasing attention over the past decade as data suggest a major role in the pathophysiology/recovery after ischemic injury. T cells offer an attractive therapeutic target due to their relatively delayed infiltration into the ischemic brain. This review will focus on T cell immune responses in ischemic stroke, highlighting studies examining the effects of aging and biological sex.

Kinetics of Xist-induced gene silencing can be predicted from combinations of epigenetic and genomic features

To initiate X-Chromosome inactivation (XCI), the long noncoding RNA Xist mediates chromosome-wide gene silencing of one X Chromosome in female mammals to equalize gene dosage between the sexes. The efficiency of gene silencing is highly variable across genes, with some genes even escaping XCI in somatic cells. A gene's susceptibility to Xist-mediated silencing appears to be determined by a complex interplay of epigenetic and genomic features; however, the underlying rules remain poorly understood. We have quantified chromosome-wide gene silencing kinetics at the level of the nascent transcriptome using allele-specific Precision nuclear Run-On sequencing (PRO-seq). We have developed a Random Forest machine-learning model that can predict the measured silencing dynamics based on a large set of epigenetic and genomic features and tested its predictive power experimentally. The genomic distance to the Xist locus, followed by gene density and distance to LINE elements, are the prime determinants of the speed of gene silencing. Moreover, we find two distinct gene classes associated with different silencing pathways: a class that requires Xist-repeat A for silencing, which is known to activate the SPEN pathway, and a second class in which genes are premarked by Polycomb complexes and tend to rely on the B repeat in Xist for silencing, known to recruit Polycomb complexes during XCI. Moreover, a series of features associated with active transcriptional elongation and chromatin 3D structure are enriched at rapidly silenced genes. Our machine-learning approach can thus uncover the complex combinatorial rules underlying gene silencing during X inactivation.

The Pregnancy Pickle: Evolved Immune Compensation Due to Pregnancy Underlies Sex Differences in Human Diseases

We hypothesize that, ancestrally, sex-specific immune modulation evolved to facilitate survival of the pregnant person in the presence of an invasive placenta and an immunologically challenging pregnancy - an idea we term the 'pregnancy compensation hypothesis' (PCH). Further, we propose that sex differences in immune function are mediated, at least in part, by the evolution of gene content and dosage on the sex chromosomes, and are regulated by reproductive hormones. Finally, we propose that changes in reproductive ecology in industrialized environments exacerbate these evolved sex differences, resulting in the increasing risk of autoimmune disease observed in females, and a counteracting reduction in diseases such as cancer that can be combated by heightened immune surveillance. The PCH generates a series of expectations that can be tested empirically and that may help to identify the mechanisms underlying sex differences in modern human diseases.

An isolated Xp deletion is linked to autoimmune diseases in Turner syndrome

Background Females with Turner syndrome (TS) are prone to develop autoimmune diseases (AIDs). The X chromosome contains several immune-related genes. Growth hormone (GH) and estrogens modulate the immune system. We aimed to clarify whether the loss of a specific X chromosome gene locus and the administration of GH and estradiol facilitate the development of AIDs in TS females. Methods Retrospective data on clinical course, AIDs, karyotype and treatment were analyzed from a cohort of 286 Czech females with TS (current age 2.8-43.3 years; median age 18.7 years). The karyotypes were sorted using two different classification systems: a mosaicism-focused and an isochromosome (isoXq)-focused approach. Karyotype subgroups with a significantly higher prevalence of AIDs were further evaluated. Data of common therapies were correlated with the prevalence of AIDs. Results The most frequent AIDs were autoimmune thyroid disease (AITD; 37.4%; n = 107) and celiac disease (CD; 8.7%; n = 25). All karyotype subgroups were prone to develop AIDs. Females with an isolated Xp deletion had a significantly higher prevalence of AITD and CD compared to all other individuals with TS (AITD: 66.0% vs. 31.5%, p < 0.0001; CD: 17.4% vs. 7.2%; p = 0.04, respectively). We observed no link between the mean age at initiation as well as the duration of GH and/or estrogen administration and the occurrence of AIDs. Conclusions Isolated Xp deletion contributes to the development of AIDs in TS patients. The haploinsufficiency of genes located in Xpter-p11.2 may explain this observation. Common therapies used in TS do not modify the risk of AIDs.

Ontogenetic and Pathogenetic Views on Somatic Chromosomal Mosaicism

Intercellular karyotypic variability has been a focus of genetic research for more than 50 years. It has been repeatedly shown that chromosome heterogeneity manifesting as chromosomal mosaicism is associated with a variety of human diseases. Due to the ability of changing dynamically throughout the ontogeny, chromosomal mosaicism may mediate genome/chromosome instability and intercellular diversity in health and disease in a bottleneck fashion. However, the ubiquity of negligibly small populations of cells with abnormal karyotypes results in difficulties of the interpretation and detection, which may be nonetheless solved by post-genomic cytogenomic technologies. In the post-genomic era, it has become possible to uncover molecular and cellular pathways to genome/chromosome instability (chromosomal mosaicism or heterogeneity) using advanced whole-genome scanning technologies and bioinformatic tools. Furthermore, the opportunities to determine the effect of chromosomal abnormalities on the cellular phenotype seem to be useful for uncovering the intrinsic consequences of chromosomal mosaicism. Accordingly, a post-genomic review of chromosomal mosaicism in the ontogenetic and pathogenetic contexts appears to be required. Here, we review chromosomal mosaicism in its widest sense and discuss further directions of cyto(post)genomic research dedicated to chromosomal heterogeneity.

Sex Effects on Gene Expression in Lacrimal Glands of Mouse Models of Sjögren Syndrome

Purpose

Sjögren syndrome is an autoimmune disease that occurs primarily in women, and is associated with lacrimal gland inflammation and aqueous-deficient dry eye. We hypothesize that sex-associated differences in lacrimal gland gene expression are very important in promoting lymphocyte accumulation in this tissue and contribute to the onset, progression, and/or severity of the inflammatory disease process. To test our hypothesis, we explored the nature and extent of sex-related differences in gene expression in autoimmune lacrimal glands.

Methods

Lacrimal glands were collected from age-matched, adult, male and female MRL/MpJ-Tnfrsf6^lpr (MRL/lpr) and nonobese diabetic/LtJ (NOD) mice. Glands were processed for the analysis of differentially expressed mRNAs by using CodeLink Bioarrays and Affymetrix GeneChips. Data were evaluated with bioinformatics and statistical software.

Results

Our results show that sex significantly influences the expression of thousands of genes in lacrimal glands of MRL/lpr and NOD mice. The immune nature of this glandular response is very dependent on the Sjögren syndrome model. Lacrimal glands of female, as compared with male, MRL/lpr mice contain a significant increase in the expression of genes related to inflammatory responses, antigen processing, and chemokine pathways. In contrast, it is the lacrimal tissue of NOD males, and not females, that presents with a significantly greater expression of immune-related genes.

Conclusions

These data support our hypothesis that sex-related differences in gene expression contribute to lacrimal gland disease in Sjögren syndrome. Our findings also suggest that factors in the lacrimal gland microenvironment are critically important in mediating these sex-associated immune effects.

Sex and autoimmunity: proposed mechanisms of disease onset and severity

INTRODUCTION

Chronic autoimmune diseases affect 5-10% of the population worldwide and are largely predominant in women. Sex hormone changes have been widely investigated based on changes in the clinical phenotypes observed during pregnancy and menopause. It is known that females with autoimmune diseases manifest a higher rate of circulating leukocytes with a single X chromosome, and there have been several reports on the role of X chromosome gene dosage through inactivation or duplication in autoimmunity. However, it is also important not to overlook men with autoimmune diseases, who might manifest a more frequent loss of the Y chromosome in circulating leukocytes. Areas covered: In the present review, we will discuss the current evidence supporting the mechanisms of female predominance in rheumatic diseases, by discussing the role of reproductive history, sex hormones and abnormalities related to them, clinical differences between male and female patients, and epigenetic changes that have been evaluated through twin studies on genetic and environmental changes in rheumatic patients. Expert opinion: The influence of sex hormones and chromosomes on the function of the innate and adaptive immune systems needs to be clarified, to better understand the risk of autoimmune diseases, early diagnostic tools, and therapeutic response.