Xist Deletion in B Cells Results in Systemic Lupus Erythematosus Phenotypes.

Systemic lupus erythematosus (SLE) is an autoimmune disease preferentially observed in females. X-linked gene expression in XX females is normalized to that of XY males by X-Chromosome Inactivation (XCI). However, B cells from female SLE patients and mouse models of SLE exhibit mislocalization of Xist RNA, a critical regulator of XCI, and aberrant expression of X-linked genes, suggesting that impairment of XCI may contribute to disease. Here, we find that a subset of female mice harboring a conditional deletion of Xis t in B cells ("Xist cKO") spontaneously develop SLE phenotypes, including expanded activated B cell subsets, disease-specific autoantibodies, and glomerulonephritis. Moreover, pristane-induced SLE-like disease is more severe in Xist cKO mice. Activated B cells from Xist cKO mice with SLE phenotypes have increased expression of proinflammatory X-linked genes implicated in SLE. Together, this work indicates that impaired XCI maintenance in B cells directly contributes to the female-bias of SLE.

Type I interferon alters invasive extravillous trophoblast function.

Inappropriate type I interferon (IFN) signaling during embryo implantation and placentation is linked to poor pregnancy outcomes. Here, we evaluated the consequence of elevated type I IFN exposure on implantation using a biomimetic model of human implantation in an organ-on-a-chip device. We found that type I IFN reduced extravillous trophoblast (EVT) invasion capacity. Analyzing single-cell transcriptomes, we uncovered that IFN truncated endovascular EVT emergence in the implantation-on-a-chip device by stunting EVT epithelial-to-mesenchymal transition. Disruptions to the epithelial-to-mesenchymal transition is associated with the pathogenesis of preeclampsia, a life-threatening hypertensive disorder of pregnancy. Strikingly, unwarranted IFN stimulation induced genes associated with increased preeclampsia risk and a preeclamptic gene-like signature in EVTs. These dysregulated EVT phenotypes ultimately reduced EVT-mediated endothelial cell vascular remodeling in the implantation-on-a-chip device. Overall, our work indicates IFN signaling can alter EVT epithelial-to-mesenchymal transition progression which results in diminished EVT-mediated spiral artery remodeling and a preeclampsia gene signature upon sustained stimulation. Our work implicates unwarranted type I IFN as a maternal disturbance that can result in abnormal EVT function that could trigger preeclampsia.

The conneXion between sex and immune responses.

There are notable sex-based differences in immune responses to pathogens and self-antigens, with female individuals exhibiting increased susceptibility to various autoimmune diseases, and male individuals displaying preferential susceptibility to some viral, bacterial, parasitic and fungal infections. Although sex hormones clearly contribute to sex differences in immune cell composition and function, the presence of two X chromosomes in female individuals suggests that differential gene expression of numerous X chromosome-linked immune-related genes may also influence sex-biased innate and adaptive immune cell function in health and disease. Here, we review the sex differences in immune system composition and function, examining how hormones and genetics influence the immune system. We focus on the genetic and epigenetic contributions responsible for altered X chromosome-linked gene expression, and how this impacts sex-biased immune responses in the context of pathogen infection and systemic autoimmunity.

NF-κB Signaling is Required for X-Chromosome Inactivation Maintenance Following T cell Activation.

X Chromosome Inactivation (XCI) is a female-specific process which balances X-linked gene dosage between sexes. Unstimulated T cells lack cytological enrichment of Xist RNA and heterochromatic modifications on the inactive X chromosome (Xi), and these modifications become enriched at the Xi after cell stimulation. Here, we examined allele-specific gene expression and the epigenomic profiles of the Xi following T cell stimulation. We found that the Xi in unstimulated T cells is largely dosage compensated and is enriched with the repressive H3K27me3 modification, but not the H2AK119-ubiquitin (Ub) mark, even at promoters of XCI escape genes. Upon CD3/CD28-mediated T cell stimulation, the Xi accumulates H2AK119-Ub and H3K27me3 across the Xi. Next, we examined the T cell signaling pathways responsible for Xist RNA localization to the Xi and found that T cell receptor (TCR) engagement, specifically NF-κB signaling downstream of TCR, is required. Disruption of NF-κB signaling, using inhibitors or genetic deletions, in mice and patients with immunodeficiencies prevents Xist/XIST RNA accumulation at the Xi and alters expression of some X-linked genes. Our findings reveal a novel connection between NF-κB signaling pathways which impact XCI maintenance in female T cells.

Cost of Treating Cutaneous T-Cell Lymphoma in Spain: Analysis of MICADOS Study Data by Disease Stage. / Evaluación de los costes asociados a la enfermedad de pacientes con linfoma cutáneo de células T en España: análisis en función del estadio clínico (estudio MICADOS).

BACKGROUND AND OBJECTIVE: The cost of treating cutaneous T-cell lymphoma (CTCL) in Spain is unknown. With the advent of new treatments, it is more important than ever to gain an accurate picture of the true costs involved. The MICADOS study had 2 primary objectives: 1)to evaluate the impact of CTCL on patient quality of life, and 2)to evaluate the costs associated with the disease. This article reports the results of the cost analysis. METHODS: We estimated the cost of treating CTCL over a period of 1year from the perspective of the Spanish National Health System. Twenty-three dermatologists and hematologists from 15 public hospitals analyzed data for adult patients with mycosis fungoides (MF) or Sézary syndrome (SS). RESULTS: A total of 141 patients (57.4% male) with a mean age of 63.6 years (95%CI: 61.4-65.7 years) were included. The mean direct annual cost of treating CTCL was €34,214 per patient. The corresponding costs by stage were €11,952.47 for stageI disease, €23,506.21 for stageII disease, €38,771.81 for stageIII disease, and €72,748.84 for stageIV disease. The total direct annual cost of treating MF/SS in public hospitals in Spain was estimated at €78,301,171; stageI disease accounted for 81% of all costs, stageII for 7%, and stagesIII andIV for 6% each. CONCLUSIONS: The MICADOS study offers an accurate picture of the direct cost of treating CTCL in patients with MF/SS in Spain and shows that costs vary significantly according to disease stage. Patient-borne and indirect costs should be analyzed in future studies.

[Translated article] Cost of Treating Cutaneous T-Cell Lymphoma in Spain: Analysis of MICADOS Study Data by Disease Stage.

BACKGROUND AND OBJECTIVE: The cost of treating cutaneous T-cell lymphoma (CTCL) in Spain is unknown. With the advent of new treatments, it is more important than ever to gain an accurate picture of the true costs involved. The MICADOS study had 2 primary objectives: 1)to evaluate the impact of CTCL on patient quality of life, and 2)to evaluate the costs associated with the disease. This article reports the results of the cost analysis. METHODS: We estimated the cost of treating CTCL over a period of 1year from the perspective of the Spanish National Health System. Twenty-three dermatologists and hematologists from 15 public hospitals analyzed data for adult patients with mycosis fungoides (MF) or Sézary syndrome (SS). RESULTS: A total of 141 patients (57.4% male) with a mean age of 63.6 years (95%CI: 61.4-65.7 years) were included. The mean direct annual cost of treating CTCL was €34,214 per patient. The corresponding costs by stage were €11,952.47 for stageI disease, €23,506.21 for stageII disease, €38,771.81 for stageIII disease, and €72,748.84 for stageIV disease. The total direct annual cost of treating MF/SS in public hospitals in Spain was estimated at €78,301,171; stageI disease accounted for 81% of all costs, stageII for 7%, and stagesIII andIV for 6% each. CONCLUSIONS: The MICADOS study offers an accurate picture of the direct cost of treating CTCL in patients with MF/SS in Spain and shows that costs vary significantly according to disease stage. Patient-borne and indirect costs should be analyzed in future studies.

Impaired dynamic X-chromosome inactivation maintenance in T cells is a feature of spontaneous murine SLE that is exacerbated in female-biased models.

OBJECTIVE: Systemic lupus erythematosus (SLE) is a highly female-biased systemic autoimmune disease, but the molecular basis for this female bias remains incompletely elucidated. B and T lymphocytes from patients with SLE and female-biased mouse models of SLE exhibit features of epigenetic dysregulation on the X chromosome which may contribute to this strong female bias. We therefore examined the fidelity of dynamic X-chromosome inactivation maintenance (dXCIm) in the pathogenesis of two murine models of spontaneous lupus-NZM2328 and MRL/lpr-with disparate levels of female-bias to determine whether impaired dXCIm contributes to the female bias of disease. METHODS: CD23+ B cells and CD3+ T cells were purified from age-matched C57BL/6 (B6), MRL/lpr, and NZM2328 male and female mice, activated in vitro, and processed for Xist RNA fluorescence in situ hybridization, H3K27me3 immunofluorescence imaging, qPCR, and RNA sequencing analyses. RESULTS: The dynamic relocalization of Xist RNA and the canonical heterochromatin mark, H3K27me3, to the inactive X chromosome was preserved in CD23+ B cells, but impaired in activated CD3+ T cells from the MRL/lpr model (p < 0.01 vs. B6), and even more impaired in the heavily female-biased NZM2328 model (p < 0.001 vs. B6; p < 0.05 vs. MRL/lpr). RNAseq of activated T cells from NZM2328 mice revealed the female-biased upregulation of 32 X-linked genes distributed broadly across the X chromosome, many of which have roles in immune function. Many genes encoding Xist RNA-interacting proteins were also differentially expressed and predominantly downregulated, which may account for the observed mislocalization of Xist RNA to the inactive X chromosome. CONCLUSIONS: Although evident in T cells from both the MRL/lpr and NZM2328 models of spontaneous SLE, impaired dXCIm is more severe in the heavily female-biased NZM2328 model. The aberrant X-linked gene dosage in female NZM2328 mice may contribute towards the development of female-biased immune responses in SLE-prone hosts. These findings provide important insights into the epigenetic mechanisms contributing to female-biased autoimmunity.

Unusual X chromosome inactivation maintenance in female alveolar type 2 cells is correlated with increased numbers of X-linked escape genes and sex-biased gene expression.

Sex differences exist for many lung pathologies, including COVID-19 and pulmonary fibrosis, but the mechanistic basis for this remains unclear. Alveolar type 2 cells (AT2s), which play a key role in alveolar lung regeneration, express the X-linked Ace2 gene that has roles in lung repair and SARS-CoV-2 pathogenesis, suggesting that X chromosome inactivation (XCI) in AT2s might impact sex-biased lung pathology. Here we investigate XCI maintenance and sex-specific gene expression profiles using male and female AT2s. Remarkably, the inactive X chromosome (Xi) lacks robust canonical Xist RNA "clouds" and less enrichment of heterochromatic modifications in human and mouse AT2s. We demonstrate that about 68% of expressed X-linked genes in mouse AT2s, including Ace2, escape XCI. There are genome-wide expression differences between male and female AT2s, likely influencing both lung physiology and pathophysiologic responses. These studies support a renewed focus on AT2s as a potential contributor to sex-biased differences in lung disease.

The X in seX-biased immunity and autoimmune rheumatic disease.

Sexual dimorphism in the composition and function of the human immune system has important clinical implications, as males and females differ in their susceptibility to infectious diseases, cancers, and especially systemic autoimmune rheumatic diseases. Both sex hormones and the X chromosome, which bears a number of immune-related genes, play critical roles in establishing the molecular basis for the observed sex differences in immune function and dysfunction. Here, we review our current understanding of sex differences in immune composition and function in health and disease, with a specific focus on the contribution of the X chromosome to the striking female bias of three autoimmune rheumatic diseases.

Long Noncoding RNAs That Function in Nutrition: Lnc-ing Nutritional Cues to Metabolic Pathways.

Long noncoding RNAs (lncRNAs) are sensitive to changing environments and play key roles in health and disease. Emerging evidence indicates that lncRNAs regulate gene expression to shape metabolic processes in response to changing nutritional cues. Here we review various lncRNAs sensitive to fasting, feeding, and high-fat diet in key metabolic tissues (liver, adipose, and muscle), highlighting regulatory mechanisms that trigger expression changes of lncRNAs themselves, and how these lncRNAs regulate gene expression of key metabolic genes in specific cell types or across tissues. Determining how lncRNAs respond to changes in nutrition is critical for our understanding of the complex downstream cascades following dietary changes and can shape how we treat metabolic disease. Furthermore, investigating sex biases that might influence lncRNA-regulated responses will likely reveal contributions toward the observed disparities between the sexes in metabolic diseases.

Linfoma cutáneo primario T CD8+ tipo acral inducido por hipersensibilidad retardada persistente a pendientes de oro / Primary Cutaneous Acral CD8+ T-cell Lymphoma Induced by Persistent Delayed Hypersensitivity to Gold Earrings

El linfoma cutáneo primario T CD8+ tipo acral ha sido incluido como entidad provisional dentro de la nueva clasificación revisada de las neoplasias linfoides de la Organización Mundial de la Salud en 20161. Inicialmente fue descrito como proliferación linfoide CD8+ indolente de la oreja2, y se han publicado en la literatura un total de 29 casos de dicha neoplasia. Ninguno de ellos se ha relacionado con reacciones de hipersensibilidad retardada de contacto. Presentamos un caso de linfoma cutáneo primario T CD8+ tipo acral auricular bilobular en clara relación etiológica con el uso prolongado de unos pendientes de oro confirmada con pruebas epicutáneas, estudio histológico, inmunohistoquímico y molecular. Las lesiones cutáneas bilobulares fueron inducidas de nuevo con un test de uso e idénticos resultados a los iniciales y misma clonalidad, lo cual terminó de confirmar tanto el diagnóstico del linfoma como su inducción por el estímulo antigénico del oro (AU)

Primary cutaneous CD8+ T-cell lymphoma has been included as a provisional entity within the new revised classification of lymphoid neoplasms of the World Health Organization in 20161. It was initially described as indolent CD8+ lymphoid proliferation of the ear2 and a total of 29 cases of such neoplasm have been published in the literature so far. None of them have been linked to delayed contact hypersensitivity reactions. We present a case of acral type primary cutaneous lymphoma T CD8+ involving both earlobes clearly related with the prolonged use of gold earrings, confirmed with epicutaneous tests, histopathology, immunohistochemical and molecular studies. Auricular skin lesions were induced again with a provocation test with identical histopathologycal and the same clonality, confirming both the diagnosis of lymphoma and its induction by the antigenic stimulus of gold (AU)

The dynamic epigenetic regulation of the inactive X chromosome in healthy human B cells is dysregulated in lupus patients.

Systemic lupus erythematous (SLE) is a female-predominant disease characterized by autoimmune B cells and pathogenic autoantibody production. Individuals with two or more X chromosomes are at increased risk for SLE, suggesting that X-linked genes contribute to the observed sex bias of this disease. To normalize X-linked gene expression between sexes, one X in female cells is randomly selected for transcriptional silencing through X-chromosome inactivation (XCI), resulting in allele-specific enrichment of epigenetic modifications, including histone methylation and the long noncoding RNA XIST/Xist on the inactive X (Xi). As we have previously shown that epigenetic regulation of the Xi in female lymphocytes from mice is unexpectedly dynamic, we used RNA fluorescence in situ hybridization and immunofluorescence to profile epigenetic features of the Xi at the single-cell level in human B cell subsets from pediatric and adult SLE patients and healthy controls. Our data reveal that abnormal XCI maintenance in B cells is a feature of SLE. Using single-cell and bulk-cell RNA sequencing datasets, we found that X-linked immunity genes escape XCI in specific healthy human B cell subsets and that human SLE B cells exhibit aberrant expression of X-linked genes and XIST RNA interactome genes. Our data reveal that mislocalized XIST RNA, coupled with a dramatic reduction in heterochromatic modifications at the Xi in SLE, predispose for aberrant X-linked gene expression from the Xi, thus defining a genetic and epigenetic pathway that affects X-linked gene expression in human SLE B cells and likely contributes to the female bias in SLE.

Primary Cutaneous Acral CD8+ T-cell Lymphoma Induced by Persistent Delayed Hypersensitivity to Gold Earrings. / Linfoma cutáneo primario T CD8+ tipo acral inducido por hipersensibilidad retardada persistente a pendientes de oro.

Primary cutaneous CD8+ T-cell lymphoma has been included as a provisional entity within the new revised classification of lymphoid neoplasms of the World Health Organization in 20161. It was initially described as indolent CD8+ lymphoid proliferation of the ear2 and a total of 29 cases of such neoplasm have been published in the literature so far. None of them have been linked to delayed contact hypersensitivity reactions. We present a case of acral type primary cutaneous lymphoma T CD8+ involving both earlobes clearly related with the prolonged use of gold earrings, confirmed with epicutaneous tests, histopathology, immunohistochemical and molecular studies. Auricular skin lesions were induced again with a provocation test with identical histopathologycal and the same clonality, confirming both the diagnosis of lymphoma and its induction by the antigenic stimulus of gold.

Derivation and investigation of the first human cell-based model of Beckwith-Wiedemann syndrome.

Genomic imprinting is a rare form of gene expression in mammals in which a small number of genes are expressed in a parent-of-origin-specific manner. The aetiology of human imprinting disorders is diverse and includes chromosomal abnormalities, mutations, and epigenetic dysregulation of imprinted genes. The most common human imprinting disorder is Beckwith-Wiedemann syndrome (BWS), frequently caused by uniparental isodisomy and DNA methylation alterations. Because these lesions cannot be easily engineered, induced pluripotent stem cells (iPSC) are a compelling alternative. Here, we describe the first iPSC model derived from patients with BWS. Due to the mosaic nature of BWS patients, both BWS and non-BWS iPSC lines were derived from the same patient's fibroblasts. Importantly, we determine that DNA methylation and gene expression patterns of the imprinted region in the iPSC lines reflect the parental cells and are stable over time. Additionally, we demonstrate that differential expression in insulin signalling, cell proliferation, and cell cycle pathways was seen in hepatocyte lineages derived from BWS lines compared to controls. Thus, this cell based-model can be used to investigate the role of imprinting in the pathogenesis of BWS in disease-relevant cell types.

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.

Estradiol promotes and progesterone reduces anxiety-like behavior produced by nicotine withdrawal in female rats.

This study assessed sex differences and the role of ovarian hormones in nicotine withdrawal. Study 1 compared physical signs, anxiety-like behavior, and corticosterone levels in male, intact female, and ovariectomized (OVX) female rats during nicotine withdrawal. Estradiol (E2) and progesterone levels were also assessed in intact females that were tested during different phases of the 4-day estrous cycle. Study 2 assessed the role of ovarian hormones in withdrawal by comparing the same measures in OVX rats that received vehicle, E2, or E2+progesterone prior to testing. Briefly, rats received a sham surgery or an ovariectomy procedure. Fifteen days later, rats were prepared with a pump that delivered nicotine for 14 days. On the test day, rats received saline or the nicotinic receptor antagonist, mecamylamine to precipitate withdrawal. Physical signs and anxiety-like behavior were assessed on the elevated plus maze (EPM) and light-dark transfer (LDT) tests. During withdrawal, intact females displayed greater anxiety-like behavior and increases in corticosterone levels as compared to male and OVX rats. Females tested in the estrus phase (when E2 is relatively low) displayed less anxiety-like behavior and had lower corticosterone levels versus all other phases. Anxiety-like behavior and corticosterone levels were positively correlated with E2 and negatively correlated with progesterone levels. Intact females displaying high E2/low progesterone showed greater anxiety-like behavior and corticosterone levels as compared to females displaying low E2/high progesterone. Lastly, OVX-E2 rats displayed greater anxiety-like behavior than OVX-E2+progesterone rats. These data suggest that E2 promotes and progesterone reduces anxiety-like behavior produced by nicotine withdrawal.

Loss of epigenetic modifications on the inactive X chromosome and sex-biased gene expression profiles in B cells from NZB/W F1 mice with lupus-like disease.

The mechanisms underlying the female-bias in autoimmunity are poorly understood. The contribution of genetic and epigenetic factors from the inactive X chromosome (Xi) are beginning to emerge as critical mediators of autoimmunity in females. Here, we ask how epigenetic features of the Xi change during disease development in B cells from the NZB/W F1 spontaneous mouse model of lupus, which is female-biased. We find that Xist RNA becomes increasingly mislocalized from the Xi with disease onset. While NZB/W F1 naïve B cells have H3K27me3 foci on the Xi, which are missing from healthy C57BL/6 and BALB/c mice, these foci are progressively lost in stimulated B cells during disease. Using single-molecule RNA FISH, we show that the X-linked gene Tlr7 is biallelically expressed in ~20% of NZB/W F1 B cells, and that the amount of biallelic expression does not change with disease. We also present sex-specific gene expression profiles for diseased NZB/W F1 B cells, and find female-specific upregulation of 20 genes, including the autoimmunity-related genes Cxcl13, Msr1, Igj, and Prdm1. Together, these studies provide important insight into the loss of epigenetic modifications from the Xi and changes with gene expression in a mouse model of female-biased SLE.

Sex differences in cholinergic systems in the interpeduncular nucleus following nicotine exposure and withdrawal.

The medial habenula-interpeduncular nucleus (MHb-IPN) pathway modulates negative affective states produced by nicotine withdrawal. Sex differences in the contribution of acetylcholine (ACh) systems in this pathway have not been explored. Thus, this study assessed ACh levels and gene expression of α- and ß-containing nicotinic acetylcholine receptor (nAChR) subunits in the IPN of female and male rats following nicotine treatment and withdrawal. Rats were prepared with a pump that delivered nicotine for 14 days, and naïve controls received a sham surgery. In Study 1, rats were prepared with a probe in the IPN, and ACh levels were measured following saline and then mecamylamine administration. In Study 2, separate groups of naïve control or nicotine-treated rats received saline or mecamylamine and physical signs and anxiety-like behavior were assessed using elevated plus maze (EPM) procedures. The IPN was then dissected and mRNA levels were assessed using RT-qPCR methods. Nicotine treatment increased ACh levels to a larger extent in females than males. Nicotine withdrawal produced a similar increase in physical signs; however, females displayed greater anxiety-like behavior than males. In females, gene expression of α5 increased following nicotine treatment and withdrawal. In males, α7 increased following nicotine treatment and α2 and α3 increased during nicotine withdrawal. Both females and males displayed an increase in ß3 and ß4 during nicotine withdrawal. In females, anxiety-like behavior was correlated with α4, α5, and ß2 gene expression in the IPN. These results suggest that sex differences in withdrawal are modulated via cholinergic systems in the IPN.