Sex-related factors in multiple sclerosis susceptibility and progression

Current understanding of cardiovascular autonomic dysfunction in multiple sclerosis

Autoimmune diseases, including multiple sclerosis (MS), are proven to increase the likelihood of developing cardiovascular disease (CVD) due to a robust systemic immune response and inflammation. MS can lead to cardiovascular abnormalities that are related to autonomic nervous system dysfunction by causing inflammatory lesions surrounding tracts of the autonomic nervous system in the brain and spinal cord. CVD in MS patients can affect an already damaged brain, thus worsening the disease course by causing brain atrophy and white matter disease. Currently, the true prevalence of cardiovascular dysfunction and associated death rates in patients with MS are mostly unknown and inconsistent. Treating vascular risk factors is recommended to improve the management of this disease. This review provides an updated summary of CVD prevalence in patients with MS, emphasizing the need for more preclinical studies using animal models to understand the pathogenesis of MS better. However, no distinct studies exist that explore the temporal effects and etiopathogenesis of immune/inflammatory cells on cardiac damage and dysfunction associated with MS, particularly in the cardiac myocardium. To this end, a thorough investigation into the clinical presentation and underlying mechanisms of CVD must be conducted in patients with MS and preclinical animal models. Additionally, clinicians should monitor for cardiovascular complications while prescribing medications to MS patients, as some MS drugs cause severe CVD.

Span of spleen is associated with disability status in multiple sclerosis: a cross-sectional abdominopelvic ultrasonography study

Characteristics of livers and spleens of people with multiple sclerosis (pwMS) could constitute good biomarkers of MS-related characteristics such as the disability status. To test the hypothesis "the gross anatomical features of livers and spleens, are not similar between pwMS with different disease characteristics" a cross-sectional study was conducted on pwMS seen at the Isfahan MS clinic, Iran, from February until December 2023. Definitive, otherwise-healthy, pwMS were enrolled after an initial laboratory evaluation. Presence/absence and grading of non-alcoholic fatty liver disease (NAFLD) and the span of spleen were determined by a radiologist using high-resolution abdominopelvic ultrasonography. 193 pwMS (160 women) were enrolled. Of whom, 143 (74.1%) were receiving first-line disease-modifying therapies (DMTs), 24 (12.4%) fingolimod, and 26 (13.5%) rituximab. The span of spleen was negatively associated with EDSS (adjusted β [SE] - 4.08 [1.52], p < 0.01), as well as 6 m-CDW (adjusted β [SE] - 6.94 [3.56], p = 0.05), unlike age, DMTs, and MS duration (all with p > 0.05). Receiver operating characteristic analysis showed, spleen span performs significant but poor in discrimination of EDSS > 1 from EDSS = 1 (area under curve [AUC] 0.62, SE 0.05, p < 0.01), yet, significant and fair in discrimination of presence from absence of 6 m-CDW (AUC 0.72, SE 0.06, p < 0.01). Other findings were unremarkable. Further longitudinal, prospective studies are warranted to confirm whether smaller spleens are predictive of higher disability accrual rate in pwMS. Particularly, findings require further validation in untreated/treatment-naïve pwMS, and ones with higher EDSS scores.

Sex differences in brain resilience of individuals with multiple sclerosis

BACKGROUND

Brain resilience allows maintenance of neurocognitive function in the face of age or disease-related neural changes.

OBJECTIVE

Test the hypothesis that women and men with MS differ in brain resilience.

METHODS

This cross-sectional analysis of prospective cohort data included 11,297 patients. Linear mixed effects models predicted performance outcomes on tasks of fine motor dexterity and cognitive processing speed for MRI proxies of disease burden: brain parenchymal fraction (BPF), T2 lesion volume, volumes of deep gray, thalamus, white and cortical gray matter. Covariates were age, sex, age-by-sex, current disease-modifying therapy, disease phenotype, education, total brain volume, and total brain volume-by-sex. Sex-by-MRI metric terms tested primary hypothesis of differential brain-behavior relationships between men and women.

RESULTS

Final sample included 10,286 participants. Lower BPF was associated with worse performance (p's<0.001) in men and women; association was smaller for women than men for processing speed (βetaWomen-Men=-0.044, 95 % CI=[-0.087, -0.002], p = 0.041) and manual dexterity (βetaWomen-Men=-0.073, 95 % CI=[-0.124, -0.023], p = 0.005). For each MRI variable, women demonstrated better neurocognitive function controlling for disease burden.

DISCUSSION

Sex differences in brain metric-neurofunctional performance relationships of people with MS suggest women have higher resilience than men in the face of increased disease burden. Future work exploring mechanism is warranted.

Imaging phenotypic differences in multiple sclerosis: at the crossroads of aging, sex, race, and ethnicity

Clear sex differences are observed in clinical and imaging phenotypes of multiple sclerosis (MS), which evolve significantly over the age spectrum, and more specifically, during reproductive milestones such as pregnancy and menopause. With neuroimaging being an outcome measure and also a key subclinical biomarker of subsequent clinical phenotype in MS, this comprehensive review aims to provide an overview of sex and hormone differences in structural and functional imaging biomarkers of MS, including lesion burden and location, atrophy, white matter integrity, functional connectivity, and iron distribution. Furthermore, how therapies aimed at altering sex hormones can impact imaging of women and men with MS over the lifespan is discussed. This review also explores the key intersection between age, sex, and race/ethnicity in MS, and how this intersection may affect imaging biomarkers of MS.

Probing the basis of disease heterogeneity in multiple sclerosis using genetically diverse mice

Multiple sclerosis (MS) is a complex disease with significant heterogeneity in disease course and progression. Genetic studies have identified numerous loci associated with MS risk, but the genetic basis of disease progression remains elusive. To address this, we leveraged the Collaborative Cross (CC), a genetically diverse mouse strain panel, and experimental autoimmune encephalomyelitis (EAE). The thirty-two CC strains studied captured a wide spectrum of EAE severity, trajectory, and presentation, including severe-progressive, monophasic, relapsing remitting, and axial rotary (AR)-EAE, accompanied by distinct immunopathology. Sex differences in EAE severity were observed in six strains. Quantitative trait locus analysis revealed distinct genetic linkage patterns for different EAE phenotypes, including EAE severity and incidence of AR-EAE. Machine learning-based approaches prioritized candidate genes for loci underlying EAE severity ( Abcc4 and Gpc6 ) and AR-EAE ( Yap1 and Dync2h1 ). This work expands the EAE phenotypic repertoire and identifies novel loci controlling unique EAE phenotypes, supporting the hypothesis that heterogeneity in MS disease course is driven by genetic variation.

Summary

The genetic basis of disease heterogeneity in multiple sclerosis (MS) remains elusive. We leveraged the Collaborative Cross to expand the phenotypic repertoire of the experimental autoimmune encephalomyelitis (EAE) model of MS and identify loci controlling EAE severity, trajectory, and presentation.

Disparities in DMT treatment: Demographic and neurocognitive differences between MS patients currently treated versus not treated with disease-modifying therapies

BACKGROUND

Current treatment guidelines recommend consideration of disease-modifying therapy (DMT) for all multiple sclerosis (MS) patients, but barriers to access have begun to be identified. In particular, prior studies have found that people with higher education have better access to DMTs, perhaps explained by the association of higher education with higher income. And while the majority of people with MS are women, being male is also associated with higher income. These factors argue for the need to better understand whether there are differences in DMT uptake based on sex and education. Finally, in addition to well-documented benefits of DMTs for slowing disease progression, there is growing evidence to suggest benefits of DMTs for cognitive functioning.

OBJECTIVE

Determine whether rates of DMT treatment differ based on education and sex. Secondarily, we investigate whether neurocognitive test performance differs in treated versus not treated groups.

METHODS

In cross-sectional data, mixed effects linear regression evaluated differences in education and sex of those treated versus not treated with DMTs. Models included the following predictors: age, disease duration, MS subtype, sex/education, disability, atrophy, and T2 lesion volume. Propensity score weights were extracted to obtain unbiased estimates of the relationship between DMT status and each outcome of interest. The same models evaluated performance differences between groups on an iPad-based processing speed test (PST) and manual dexterity test (MDT).

RESULTS

Controlling for covariates, individuals with less education (OR=1.09, 95 % CI=[1.03, 1.14], p = 0.003) and women (OR=0.80, 95 % CI=[0.72, 0.90], p < 0.001) were less likely to be currently treated with DMTs. Small effect size association was shown for DMT treatment with better performance on PST (beta=0.09, CI=[0.06, 0.13], p < 0.001) and MDT (beta=0.05, CI=[0.01,0.08], p = 0.011).

CONCLUSIONS

Women and people with lower education had a lower likelihood of being currently treated with DMTs. After controlling for all relevant variables, an independent (small) association of DMT treatment to better performance on tests of processing speed and fine motor dexterity was found. Reasons for disparities remain to be investigated in future work, and may include employment status, health insurance coverage, or sex differences in risk tolerance.

Mechanisms of sex differences in Alzheimer's disease

Alzheimer's disease (AD) and the mechanisms underlying its etiology and progression are complex and multifactorial. The higher AD risk in women may serve as a clue to better understand these complicated processes. In this review, we examine aspects of AD that demonstrate sex-dependent effects and delve into the potential biological mechanisms responsible, compiling findings from advanced technologies such as single-cell RNA sequencing, metabolomics, and multi-omics analyses. We review evidence that sex hormones and sex chromosomes interact with various disease mechanisms during aging, encompassing inflammation, metabolism, and autophagy, leading to unique characteristics in disease progression between men and women.

Multiple Sclerosis: An Emergency Medicine-Focused Narrative Review

BACKGROUND

Multiple sclerosis (MS) is a rare but serious condition associated with significant morbidity.

OBJECTIVE

This review provides a focused assessment of MS for emergency clinicians, including the presentation, evaluation, and emergency department (ED) management based on current evidence.

DISCUSSION

MS is an autoimmune disorder targeting the central nervous system (CNS), characterized by clinical relapses and radiological lesions disseminated in time and location. Patients with MS most commonly present with long tract signs (e.g., myelopathy, asymmetric spastic paraplegia, urinary dysfunction, Lhermitte's sign), optic neuritis, or brainstem syndromes (bilateral internuclear ophthalmoplegia). Cortical syndromes or multifocal presentations are less common. Radiologically isolated syndrome and clinically isolated syndrome (CIS) may or may not progress to chronic forms of MS, including relapsing remitting MS, primary progressive MS, and secondary progressive MS. The foundation of outpatient management involves disease-modifying therapy, which is typically initiated with the first signs of disease onset. Management of CIS and acute flares of MS in the ED includes corticosteroid therapy, ideally after diagnostic testing with imaging and lumbar puncture for cerebrospinal fluid analysis. Emergency clinicians should evaluate whether patients with MS are presenting with new-onset debilitating neurological symptoms to avoid unnecessary testing and admissions, but failure to appropriately diagnose CIS or MS flare is associated with increased morbidity.

CONCLUSIONS

An understanding of MS can assist emergency clinicians in better diagnosing and managing this neurologically devastating disease.

Interplay between androgen and CXCR4 chemokine signaling in myelin repair

In men, reduced levels of testosterone are associated with the prevalence and progression of multiple sclerosis (MS), a chronic and disabling demyelinating disorder. Testosterone has been shown to promote myelin repair. Here, we demonstrate that the cooperation between testosterone and CXCR4 signaling involving astrocytes is required for myelin regeneration after focal demyelination produced in the ventral mouse spinal cord by the infusion of lysolecithin. The testosterone-dependent remyelination of axons by oligodendrocytes was accompanied by an increase in astrocytes expressing CXCR4, its ligand CXCL12 and the androgen receptor (AR) within the demyelinated area. Depriving males of their testosterone or pharmacological inhibition of CXCR4, with the selective antagonist AMD3100, prevented the appearance of astrocytes expressing CXCR4, CXCL12 and AR within the demyelinated area and the concomitant recruitment of myelin forming oligodendrocytes. Conditional genetic ablation of either CXCR4 or AR in astrocytes also completely blocked the formation of new myelin by oligodendrocytes. Interestingly, the gain of function mutation in CXCR4 causing WHIM syndrome allows remyelination to take place, even in the absence of testosterone, but its potentiating effects remained observable. After testosterone deprivation or CXCR4 inhibition, the absence of astrocytes within the demyelinated area led to the incursion of Schwann cells, most likely derived from spinal nerves, and the formation of peripheral nerve type myelin. In patients with progressive MS, astrocytes expressing CXCR4 and AR surrounded myelin lesions, and their presence opposed the incursion of Schwann cells. These results highlight a mechanism of promyelinating testosterone signaling and the importance of normalizing its levels in combined myelin repair therapies.

Intestinal epithelial dopamine receptor signaling drives sex-specific disease exacerbation in a mouse model of multiple sclerosis

Although the gut microbiota can influence central nervous system (CNS) autoimmune diseases, the contribution of the intestinal epithelium to CNS autoimmunity is less clear. Here, we showed that intestinal epithelial dopamine D2 receptors (IEC DRD2) promoted sex-specific disease progression in an animal model of multiple sclerosis. Female mice lacking Drd2 selectively in intestinal epithelial cells showed a blunted inflammatory response in the CNS and reduced disease progression. In contrast, overexpression or activation of IEC DRD2 by phenylethylamine administration exacerbated disease severity. This was accompanied by altered lysozyme expression and gut microbiota composition, including reduced abundance of Lactobacillus species. Furthermore, treatment with N2-acetyl-L-lysine, a metabolite derived from Lactobacillus, suppressed microglial activation and neurodegeneration. Taken together, our study indicates that IEC DRD2 hyperactivity impacts gut microbial abundances and increases susceptibility to CNS autoimmune diseases in a female-biased manner, opening up future avenues for sex-specific interventions of CNS autoimmune diseases.

The role of genetics and gender specific differences in neurodegenerative disorders: Insights from molecular and immune landscape

Neurodegenerative disorders (NDDs) are the most common neurological disorders with high prevalence and have significant socioeconomic implications. Understanding the underlying cellular and molecular mechanisms associated with the immune system can be effective in disease etiology, leading to more effective therapeutic approaches for both females and males. The central nervous system (CNS) actively participates in immune responses, both within and outside the CNS. Immune system activation is a common feature in NDDs. Gender-specific factors play a significant role in the prevalence, progression, and manifestation of NDDs. Neuroinflammation, in both inflammatory neurological and neurodegenerative conditions, is defined by the triggering of microglia and astrocyte cell activation. This results in the secretion of pro-inflammatory cytokines and chemokines. Numerous studies have documented the role of neuroinflammation in neurological diseases, highlighting the involvement of immune signaling pathways in disease development. Converging evidence support immune system involvement during neurodegeneration in NDDs. In this review, we summarize emerging evidence that reveals gender-dependent differences in immune responses related to NDDs. Also, we highlight sex differences in immune responses and discuss how these sex-specific influences can increase the risk of NDDs. Understanding the role of gender-specific factors can aid in developing targeted therapeutic strategies and improving patient outcomes. Ultimately, the better understanding of these mechanisms contributed to sex-dependent immune response in NDDs, can be critically usful in targeting of immune signaling cascades in such disorders. In this regard, sex-related immune responses in NDDs may be promising and effective targets in therapeutic strategies.

Estrogen receptor beta in astrocytes modulates cognitive function in mid-age female mice

Menopause is associated with cognitive deficits and brain atrophy, but the brain region and cell-specific mechanisms are not fully understood. Here, we identify a sex hormone by age interaction whereby loss of ovarian hormones in female mice at midlife, but not young age, induced hippocampal-dependent cognitive impairment, dorsal hippocampal atrophy, and astrocyte and microglia activation with synaptic loss. Selective deletion of estrogen receptor beta (ERβ) in astrocytes, but not neurons, in gonadally intact female mice induced the same brain effects. RNA sequencing and pathway analyses of gene expression in hippocampal astrocytes from midlife female astrocyte-ERβ conditional knock out (cKO) mice revealed Gluconeogenesis I and Glycolysis I as the most differentially expressed pathways. Enolase 1 gene expression was increased in hippocampi from both astrocyte-ERβ cKO female mice at midlife and from postmenopausal women. Gain of function studies showed that ERβ ligand treatment of midlife female mice reversed dorsal hippocampal neuropathology.

Beyond the amyloid hypothesis: how current research implicates autoimmunity in Alzheimer's disease pathogenesis

The amyloid hypothesis has so far been at the forefront of explaining the pathogenesis of Alzheimer's Disease (AD), a progressive neurodegenerative disorder that leads to cognitive decline and eventual death. Recent evidence, however, points to additional factors that contribute to the pathogenesis of this disease. These include the neurovascular hypothesis, the mitochondrial cascade hypothesis, the inflammatory hypothesis, the prion hypothesis, the mutational accumulation hypothesis, and the autoimmunity hypothesis. The purpose of this review was to briefly discuss the factors that are associated with autoimmunity in humans, including sex, the gut and lung microbiomes, age, genetics, and environmental factors. Subsequently, it was to examine the rise of autoimmune phenomena in AD, which can be instigated by a blood-brain barrier breakdown, pathogen infections, and dysfunction of the glymphatic system. Lastly, it was to discuss the various ways by which immune system dysregulation leads to AD, immunomodulating therapies, and future directions in the field of autoimmunity and neurodegeneration. A comprehensive account of the recent research done in the field was extracted from PubMed on 31 January 2022, with the keywords "Alzheimer's disease" and "autoantibodies" for the first search input, and "Alzheimer's disease" with "IgG" for the second. From the first search, 19 papers were selected, because they contained recent research on the autoantibodies found in the biofluids of patients with AD. From the second search, four papers were selected. The analysis of the literature has led to support the autoimmune hypothesis in AD. Autoantibodies were found in biofluids (serum/plasma, cerebrospinal fluid) of patients with AD with multiple methods, including ELISA, Mass Spectrometry, and microarray analysis. Through continuous research, the understanding of the synergistic effects of the various components that lead to AD will pave the way for better therapeutic methods and a deeper understanding of the disease.

Sex shapes cell-type-specific transcriptional signatures of stress exposure in the mouse hypothalamus

Stress-related psychiatric disorders and the stress system show prominent differences between males and females, as well as strongly divergent transcriptional changes. Despite several proposed mechanisms, we still lack the understanding of the molecular processes at play. Here, we explore the contribution of cell types to transcriptional sex dimorphism using single-cell RNA sequencing. We identify cell-type-specific signatures of acute restraint stress in the paraventricular nucleus of the hypothalamus, a central hub of the stress response, in male and female mice. Further, we show that a history of chronic mild stress alters these signatures in a sex-specific way, and we identify oligodendrocytes as a major target for these sex-specific effects. This dataset, which we provide as an online interactive app, offers the transcriptomes of thousands of individual cells as a molecular resource for an in-depth dissection of the interplay between cell types and sex on the mechanisms of the stress response.

Sex differences in alpha-synucleinopathies: a systematic review

Background

Past research indicates a higher prevalence, incidence, and severe clinical manifestations of alpha-synucleinopathies in men, leading to a suggestion of neuroprotective properties of female sex hormones (especially estrogen). The potential pathomechanisms of any such effect on alpha-synucleinopathies, however, are far from understood. With that aim, we undertook to systematically review, and to critically assess, contemporary evidence on sex and gender differences in alpha-synucleinopathies using a bench-to-bedside approach.

Methods

In this systematic review, studies investigating sex and gender differences in alpha-synucleinopathies (Rapid Eye Movement (REM) Behavior Disorder (RBD), Parkinson's Disease (PD), Dementia with Lewy Bodies (DLB), Multiple System Atrophy (MSA)) from 2012 to 2022 were identified using electronic database searches of PubMed, Embase and Ovid.

Results

One hundred sixty-two studies were included; 5 RBD, 6 MSA, 20 DLB and 131 PD studies. Overall, there is conclusive evidence to suggest sex-and gender-specific manifestation in demographics, biomarkers, genetics, clinical features, interventions, and quality of life in alpha-synucleinopathies. Only limited data exists on the effects of distinct sex hormones, with majority of studies concentrating on estrogen and its speculated neuroprotective effects.

Conclusion

Future studies disentangling the underlying sex-specific mechanisms of alpha-synucleinopathies are urgently needed in order to enable novel sex-specific therapeutics.

Dilatation of the bridging cerebral veins in multiple sclerosis correlates with fatigue and suggests an increase in pressure

BACKGROUND

There is a significant increase in the parenchymal microvessel blood volume in the earliest forms of multiple sclerosis (MS) which may be due to venular dilatation. Increased cortical venous pressure could account for this finding. Venous pressure is also implicated in the physiology of fatigue. The purpose of this study is to discover if there is dilatation of the veins within the subarachnoid space in multiple sclerosis and to estimate the pressures required to maintain any enlargement found. These findings will be correlated with the fatigue symptoms found in MS.

METHODS

103 patients with MS were compared with a control group of 50 patients. Post contrast 3DT1 images were used. The cross-sectional area of the bridging cortical veins and the vein of Galen were measured.

RESULTS

In MS, the superficial territory cortical veins were 29% larger and the veins of Galen were 25% larger than the controls.

CONCLUSION

There is evidence of a significant increase in the bridging vein transmural pressure in MS, estimated to be approximately 6.5 mmHg in the superficial cortical veins. MS patients with significant fatigue have larger cortical veins than those who are not significantly fatigued.

Survival and Its Correlates in Multiple Sclerosis Patients under a Universal Health Insurance Program in Taiwan: An 18-Year Nationwide Cohort Study

Despite the global decline in the standardized mortality rate of multiple sclerosis (MS), recent research on MS patient survival, especially in Taiwan, remains limited. This study aimed to investigate survival, mortality causes, and associated factors among MS patients in Taiwan. The Taiwan National Health Insurance Research Database was used as the primary data source, and a Cox proportional hazard model was employed to estimate and analyze factors related to survival. We analyzed data from 1444 MS patients diagnosed between 2000 and 2018. Age at diagnosis was positively correlated with the risk of death. Among the 190 patients who died, the leading causes of disease-related deaths were nervous system diseases (n = 83, 43.68%), followed by respiratory system diseases and certain infectious and parasitic diseases. The 8-, 13-, and 18-year survival rates for MS patients were 0.97, 0.91, and 0.81, respectively. This study highlights that the MS patient's socioeconomic status, environmental factors, comorbidity severity, and related medical variables were not significantly associated with survival.

The impact of menopause on multiple sclerosis

Menopause, defined as the permanent cessation of ovarian function, represents a period of significant fluctuation in sex hormone concentrations. Sex hormones including oestrogen, progesterone, testosterone and anti-Mullerian hormone are thought have neuroinflammatory effects and are implicated in both neuroprotection and neurodegeneration. Sex hormones are thought to have a role in modifying clinical trajectory in multiple sclerosis (MS) throughout the lifespan. Multiple sclerosis predominantly effects women and is typically diagnosed early in a woman's reproductive life. Most women with MS will undergo menopause. Despite this, the effect of menopause on MS disease course remains unclear. This review examines the relationship between sex hormones and MS disease activity and clinical course, particularly around the time of menopause. It will consider the role of interventions such as exogenous hormone replacement therapy in modulating clinical outcomes in this period. Understanding the impact of menopause on multiple sclerosis is fundamental for delivering optimal care to women with MS as they age and will inform treatment decisions with the aim of minimising relapses, disease accrual and improving quality of life.

β-Adrenoceptor Blockade Moderates Neuroinflammation in Male and Female EAE Rats and Abrogates Sexual Dimorphisms in the Major Neuroinflammatory Pathways by Being More Efficient in Males

Our previous studies showed more severe experimental autoimmune encephalomyelitis (EAE) in male compared with female adult rats, and moderating effect of propranolol-induced β-adrenoceptor blockade on EAE in females, the effect associated with transcriptional stimulation of Nrf2/HO-1 axis in spinal cord microglia. This study examined putative sexual dimorphism in propranolol action on EAE severity. Propranolol treatment beginning from the onset of clinical EAE mitigated EAE severity in rats of both sexes, but to a greater extent in males exhibiting higher noradrenaline levels and myeloid cell β₂-adrenoceptor expression in spinal cord. This correlated with more prominent stimulatory effects of propranolol not only on CX3CL1/CX3CR1/Nrf2/HO-1 cascade, but also on Stat3/Socs3 signaling axis in spinal cord microglia/myeloid cells (mirrored in the decreased Stat3 and the increased Socs3 expression) from male rats compared with their female counterparts. Propranolol diminished the frequency of activated cells among microglia, increased their phagocyting/endocyting capacity, and shifted cytokine secretory profile of microglia/blood-borne myeloid cells towards an anti-inflammatory/neuroprotective phenotype. Additionally, it downregulated the expression of chemokines (CCL2, CCL19/21) driving T-cell/monocyte trafficking into spinal cord. Consequently, in propranolol-treated rats fewer activated CD4+ T cells and IL-17+ T cells, including CD4+IL17+ cells coexpressing IFN-γ/GM-CSF, were recovered from spinal cord of propranolol-treated rats compared with sex-matched saline-injected controls. All the effects of propranolol were more prominent in males. The study as a whole disclosed that sexual dimorphism in multiple molecular mechanisms implicated in EAE development may be responsible for greater severity of EAE in male rats and sexually dimorphic action of substances affecting them. Propranolol moderated EAE severity more effectively in male rats, exhibiting greater spinal cord noradrenaline (NA) levels and myeloid cell β₂-adrenoceptor (β₂-AR) expression than females. Propranolol affected CX3CR1/Nrf2/HO-1 and Stat3/Socs3 signaling axes in myeloid cells, favored their anti-inflammatory/neuroprotective phenotype and, consequently, reduced Th cell reactivation and differentiation into highly pathogenic IL-17/IFN-γ/GM-CSF-producing cells.

Sex and Gender Differences in Neurodegenerative Diseases: Challenges for Therapeutic Opportunities

The term “neurodegenerative diseases” (NDs) identifies a group of heterogeneous diseases characterized by progressive loss of selectively vulnerable populations of neurons, which progressively deteriorates over time, leading to neuronal dysfunction. Protein aggregation and neuronal loss have been considered the most characteristic hallmarks of NDs, but growing evidence confirms that significant dysregulation of innate immune pathways plays a crucial role as well. NDs vary from multiple sclerosis, in which the autoimmune inflammatory component is predominant, to more “classical” NDs, such as Parkinson’s disease, Alzheimer’s disease, amyotrophic lateral sclerosis, and spinal muscular atrophy. Of interest, many of the clinical differences reported in NDs seem to be closely linked to sex, which may be justified by the significant changes in immune mechanisms between affected females and males. In this review, we examined some of the most studied NDs by looking at their pathogenic and phenotypical features to highlight sex-related discrepancies, if any, with particular interest in the individuals’ responses to treatment. We believe that pointing out these differences in clinical practice may help achieve more successful precision and personalized care.

Androgens show sex-dependent differences in myelination in immune and non-immune murine models of CNS demyelination

Neuroprotective, anti-inflammatory, and remyelinating properties of androgens are well-characterized in demyelinated male mice and men suffering from multiple sclerosis. However, androgen effects mediated by the androgen receptor (AR), have been only poorly studied in females who make low androgen levels. Here, we show a predominant microglial AR expression in demyelinated lesions from female mice and women with multiple sclerosis, but virtually undetectable AR expression in lesions from male animals and men with multiple sclerosis. In female mice, androgens and estrogens act in a synergistic way while androgens drive microglia response towards regeneration. Transcriptomic comparisons of demyelinated mouse spinal cords indicate that, regardless of the sex, androgens up-regulate genes related to neuronal function integrity and myelin production. Depending on the sex, androgens down-regulate genes related to the immune system in females and lipid catabolism in males. Thus, androgens are required for proper myelin regeneration in females and therapeutic approaches of demyelinating diseases need to consider male-female differences.

Pregnancy Is Associated with Impaired Transcription of Human Endogenous Retroviruses and of TRIM28 and SETDB1, Particularly in Mothers Affected by Multiple Sclerosis

Accumulating evidence highlights the pathogenetic role of human endogenous retroviruses (HERVs) in eliciting and maintaining multiple sclerosis (MS). Epigenetic mechanisms, such as those regulated by TRIM 28 and SETDB1, are implicated in HERV activation and in neuroinflammatory disorders, including MS. Pregnancy markedly improves the course of MS, but no study explored the expressions of HERVs and of TRIM28 and SETDB1 during gestation. Using a polymerase chain reaction real-time Taqman amplification assay, we assessed and compared the transcriptional levels of pol genes of HERV-H, HERV-K, HERV-W; of env genes of Syncytin (SYN)1, SYN2, and multiple sclerosis associated retrovirus (MSRV); and of TRIM28 and SETDB1 in peripheral blood and placenta from 20 mothers affected by MS; from 27 healthy mothers, in cord blood from their neonates; and in blood from healthy women of child-bearing age. The HERV mRNA levels were significantly lower in pregnant than in nonpregnant women. Expressions of all HERVs were downregulated in the chorion and in the decidua basalis of MS mothers compared to healthy mothers. The former also showed lower mRNA levels of HERV-K-pol and of SYN1, SYN2, and MSRV in peripheral blood. Significantly lower expressions of TRIM28 and SETDB1 also emerged in pregnant vs. nonpregnant women and in blood, chorion, and decidua of mothers with MS vs. healthy mothers. In contrast, HERV and TRIM28/SETDB1 expressions were comparable between their neonates. These results show that gestation is characterized by impaired expressions of HERVs and TRIM28/SETDB1, particularly in mothers with MS. Given the beneficial effects of pregnancy on MS and the wealth of data suggesting the putative contribution of HERVs and epigenetic processes in the pathogenesis of the disease, our findings may further support innovative therapeutic interventions to block HERV activation and to control aberrant epigenetic pathways in MS-affected patients.

Estrogen receptor alpha signaling in dendritic cells modulates autoimmune disease phenotype in mice

Estrogen is a disease-modifying factor in multiple sclerosis (MS) and its animal model experimental autoimmune encephalomyelitis (EAE) via estrogen receptor alpha (ERα). However, the mechanisms by which ERα signaling contributes to changes in disease pathogenesis have not been completely elucidated. Here, we demonstrate that ERα deletion in dendritic cells (DCs) of mice induces severe neurodegeneration in the central nervous system in a mouse EAE model and resistance to interferon beta (IFNβ), a first-line MS treatment. Estrogen synthesized by extragonadal sources is crucial for controlling disease phenotypes. Mechanistically, activated ERα directly interacts with TRAF3, a TLR4 downstream signaling molecule, to degrade TRAF3 via ubiquitination, resulting in reduced IRF3 nuclear translocation and transcription of membrane lymphotoxin (mLT) and IFNβ components. Diminished ERα signaling in DCs generates neurotoxic effector CD4+ T cells via mLT-lymphotoxin beta receptor (LTβR) signaling. Lymphotoxin beta receptor antagonist abolished EAE disease symptoms in the DC-specific ERα-deficient mice. These findings indicate that estrogen derived from extragonadal sources, such as lymph nodes, controls TRAF3-mediated cytokine production in DCs to modulate the EAE disease phenotype.

Sleep in multiple sclerosis: a systematic review and meta-analysis of polysomnographic findings

STUDY OBJECTIVES

This study aims to explore the polysomnographically measured sleep differences between patients with multiple sclerosis (MS) and healthy control patients.

METHODS

An electronic literature search was conducted in EMBASE, MEDLINE, all EBM databases, CINAHL, and PsycINFO from inception to March 2022. A random-effects model was applied to explore the pooled effect sizes of polysomnographic differences between patients with MS and control patients.

RESULTS

Thirteen studies were identified for meta-analysis. The meta-analyses revealed significant reductions in stage N2 sleep and sleep efficiency and increases in wake time after sleep onset, the periodic limb movement index, and the periodic limb movement arousal index in patients with MS compared with control patients. Meta-regression analyses showed that some of the heterogeneity was explained by age and daytime sleepiness of patients with MS.

CONCLUSIONS

Our study showed that polysomnographic abnormalities are present in MS. Our findings also underscore the need for a comprehensive polysomnographic assessment of sleep changes in patients with MS. Furthermore, the effects of age and daytime sleepiness in patients with MS on sleep changes should also be carefully considered and closely monitored in the management of MS.

CITATION

Zhang Y, Ren R, Yang L, et al. Sleep in multiple sclerosis: a systematic review and meta-analysis of polysomnographic findings. J Clin Sleep Med. 2023;19(2):253-265.

Relationship of Motor Impairment with Cognitive and Emotional Alterations in Patients with Multiple Sclerosis

Introduction. Multiple sclerosis (MS) is a neurodegenerative disease that, despite mainly affecting women, is more severe in men and causes motor, cognitive and emotional alterations. The objective of this study was to determine the possible relationship between motor, cognitive and emotional alterations. Materials and Methods. This is a descriptive, observational and cross-sectional study, with 67 patients with MS (20 men and 47 women), who were given the following questionnaires: Expanded Disability Status Scale (EDSS), Two-Minute Walk Test (2MWT), Berg Balance Scale, Beck’s Depression Inventory (BDI-II), State-Trait Anxiety Inventory (STAI) and Prefrontal Symptoms Inventory (PSI) to analyze their cognitive level, body mass index (BMI) and percentage of muscle mass. In addition, regression analysis was conducted to study the relationship among variables. Results. No significant differences were found between men and women in any of the variables. Regarding the relationship between parameters, the regression analysis was statistically significant, showing an effect of age on the walking and balance performance (β ≅ −0.4, p < 0.05); in addition, there was a relationship between 2MWT and STAI A/S, indicating that both older age and a high anxiety state could impact walking performance. On the other hand, prefrontal symptoms showed moderate relationships with both anxiety and depression (β ≅ 0.6, p < 0.05); thus, high levels of anxiety and depression could increase prefrontal alterations. Conclusions. There is a relationship between motor and emotional variables. Specifically, state anxiety is related to walking resistance. No relationship was found between depression and cognitive alteration and balance or walking ability. Only age has an effect in these relationships.

Evaluation of Selected Oxidant/Antioxidant Parameters in Patients with Relapsing-Remitting Multiple Sclerosis Undergoing Disease-Modifying Therapies

The aim of this study was to evaluate oxidative stress parameters, specifically the concentration of advanced oxidation protein products (AOPP) and ferric-reducing antioxidant power (FRAP), in the serum of patients with relapsing-remitting multiple sclerosis (RRMS). We also analyzed the relationships between each parameter and selected clinical/laboratory multiple-sclerosis-related parameters. The study group comprised 204 patients with RRMS and 29 healthy, age-matched controls. The concentration of AOPP was significantly higher in the RRMS patients than in controls. ROC analysis showed the ability of AOPP to distinguish between the patients with RRMS and controls (the value of AUC was 94.8%, with a sensitivity of 89.69% and specificity of 89.3%). AOPP and FRAP were significantly higher in male than in female RRMS patients. Correlations were found between AOPP and the laboratory markers of inflammation. AOPP differed in the subgroups of patients treated with particular medications. Our findings indicate an increase in the markers of oxidative stress in the serum of RRMS patients, possibly linked with chronic inflammation. Gender and type of treatment affected the markers of oxidative stress.

The X factor in neurodegeneration

Given the aging population, it is important to better understand neurodegeneration in aging healthy people and to address the increasing incidence of neurodegenerative diseases. It is imperative to apply novel strategies to identify neuroprotective therapeutics. The study of sex differences in neurodegeneration can reveal new candidate treatment targets tailored for women and men. Sex chromosome effects on neurodegeneration remain understudied and represent a promising frontier for discovery. Here, we will review sex differences in neurodegeneration, focusing on the study of sex chromosome effects in the context of declining levels of sex hormones during aging.

Sex Hormones as Key Modulators of the Immune Response in Multiple Sclerosis: A Review

BACKGROUND

A variety of autoimmune diseases, including MS, amplify sex-based physiological differences in immunological responsiveness. Female MS patients experience pathophysiological changes during reproductive phases (pregnancy and menopause). Sex hormones can act on immune cells, potentially enabling them to modify MS risk, activity, and progression, and to play a role in treatment.

METHODS

Scientific papers (published between 1998 and 2021) were selected through PubMed, Google Scholar, and Web of Science literature repositories. The search was limited to publications analyzing the hormonal profile of male and female MS patients during different life phases, in particular focusing on sex hormone treatment.

RESULTS

Both men and women with MS have lower testosterone levels compared to healthy controls. The levels of estrogens and progesterone increase during pregnancy and then rapidly decrease after delivery, possibly mediating an immune-stabilizing process. The literature examined herein evidences the neuroprotective effect of testosterone and estrogens in MS, supporting further examinations of their potential therapeutic uses.

CONCLUSIONS

A correlation has been identified between sex hormones and MS clinical activity. The combination of disease-modifying therapies with estrogen or estrogen plus a progestin receptor modulator promoting myelin repair might represent an important strategy for MS treatment in the future.

X chromosome agents of sexual differentiation

Understanding sex differences in physiology and disease requires the identification of the molecular agents that cause phenotypic sex differences. Two groups of such agents are genes located on the sex chromosomes, and gonadal hormones. The former have coherent linkage to chromosomes that form differently in the two sexes under the influence of genomic forces that are not related to reproductive function, whereas the latter have a direct or indirect relationship to reproduction. Evidence published in the past 5 years supports the identification of several agents of sexual differentiation encoded by the X chromosome in mice, including Kdm5c, Kdm6a, Ogt and Xist. These X chromosome agents have wide pleiotropic effects, potentially influencing sex differences in many different tissues, a characteristic shared with the gonadal hormones. The identification of X chromosome agents of sexual differentiation will facilitate understanding of complex intersecting gene pathways underlying sex differences in disease.

Sex and gender differences in autoimmune demyelinating CNS disorders: Multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD) and myelin-oligodendrocyte-glycoprotein antibody associated disorder (MOGAD)

Multiple sclerosis (MS), Neuromyelitis optica spectrum disorder (NMOSD) and Myelin-Oligodendrocyte-Glycoprotein antibody associated disorder (MOGAD) are demyelinating disorders of the central nervous system (CNS) of autoimmune origin. Here, we summarize general considerations on sex-specific differences in the immunopathogenesis and hormonal influences as well as key clinical and epidemiological elements. Gender-specific issues are widely neglected starting with the lacking separation of sex as a biological variable and gender comprising the sociocultural components. As for other autoimmune diseases, female preponderance is common in MS and NMOSD. However, sex distribution in MOGAD seems equal. As in MS, immunotherapy in NMOSD and MOGAD is crucial to prevent further disease activity. Therefore, we assessed data on sex differences of the currently licensed disease-modifying treatments for efficacy and safety. This topic seems widely neglected with only fragmented information resulting from post-hoc analyses of clinical trials or real-world post-marketing studies afflicted with lacking power and/or inherent sources of bias. In summary, biological hypotheses of sex differences including genetic factors, the constitution of the immune system and hormonal influences are based upon human and preclinical data, especially for the paradigmatic disease of MS whereas specific data for NMOSD and MOGAD are widely lacking. Epidemiological and clinical differences between men and women are well described for MS and to some extent for NMOSD, yet, with remaining contradictory findings. MOGAD needs further detailed investigation. Sex-specific analyses of safety and efficacy of long-term immunotherapies need to be addressed in future studies designed and powered to answer the pressing questions and to optimize and individualize treatment.

Biological Sex As a Critical Variable in CD4+ Effector T Cell Function in Preclinical Models of Multiple Sclerosis

Significance: T cells play a pivotal role in maintaining adaptive immune responses against pathogens. However, misdirected T cell responses against self-tissues may lead to autoimmune disease. Biological sex has profound effects on T cell function and is an important determinant of disease incidence and severity in autoimmune diseases such as multiple sclerosis (MS). Recent Advances: Many autoimmune diseases skew toward higher female incidence, including MS; however, it is has become increasingly more accepted that men living with MS are more prone to developing a progressive disease course and to having worsened disease outcomes. Critical Issues: In this review, we discuss what is known about the role of biological sex on T cell development and differentiation, examining evidence that male sex can augment T helper 17 (Th17) responses. Next, we outline what is known about sex differences in animal models of MS, and about the distinct roles played by sex hormones versus sex chromosomes in pathogenesis in these models. Finally, we discuss recent advances that examine the molecular basis for worsened disease outcomes in males, with a particular focus on the role played by Th17 cells in these models. Future Directions: Better understanding the role of biological sex in T cell function may pave the way to effective personalized treatment strategies in MS and other autoimmune diseases. Antioxid. Redox Signal. 37, 135-149.

Integrating Sex Chromosome and Endocrine Theories to Improve Teaching of Sexual Differentiation

Major sex differences in mammalian tissues are functionally tied to reproduction and evolved as adaptations to meet different reproductive needs of females and males. They were thus directly controlled by gonadal hormones. Factors encoded on the sex chromosomes also cause many sex differences in diverse tissues because they are present in different doses in XX and XY cells. The sex chromosome effects likely evolved not because of demands of reproduction, but as side effects of genomic forces that adaptively reduced sexual inequality. Sex-specific effects of particular factors, including gonadal hormones, therefore, are not necessarily explained as adaptations for reproduction, but also as potential factors offsetting, rather than producing, sex differences. The incorporation of these concepts would improve future teaching about sexual differentiation.

Precision Exercise Medicine: Sex Specific Differences in Immune and CNS Responses to Physical Activity

Physical activity is a powerful lifestyle factor capable of improving cognitive function, modifying the risk for dementia associated with neurodegeneration and possibly slowing neurodegenerative disease progression in both men and women. However, men and women show differences in the biological responses to physical activity and in the vulnerabilities to the onset, progression and outcome of neurodegenerative diseases, prompting the question of whether sex-specific regulatory mechanisms might differentially modulate the benefits of exercise on the brain. Mechanistic studies aimed to better understand how physical activity improves brain health and function suggest that the brain responds to physical exercise by overall reducing neuroinflammation and increasing neuroplasticity. Here, we review the emerging literature considering sex-specific differences in the immune system response to exercise as a potential mechanism by which physical activity affects the brain. Although the literature addressing sex differences in this light is limited, the initial findings suggest a potential influence of biological sex in the brain benefits of exercise, and lay out a scientific foundation to support very much needed studies investigating the potential effects of sex-differences on exercise neurobiology. Considering biological sex and sex-differences in the neurobiological hallmarks of exercise will help to enhance our understanding of the mechanisms by which physical activity benefits the brain and also improve the development of treatments and interventions for diseases of the central nervous system.

Sexual Health and Women Living With Spinal Cord Injury: The Unheard Voice

Women's sexual health within the context of sexual function and psychosocial dimensions while living with a spinal cord injury (SCI) has rarely been discussed separately from men living with a SCI or from a collective with other chronic conditions. To date, over 64,000 women in the U.S. are currently living with SCI, with total numbers increasing each year, as well as the demographics shifting to include more diversity in race and incidences occurring later in life. On average, SCI tends to be acquired during the childbearing years (~30–50 years old), as well as when women experience other health concerns associated with aging, including perimenopause and menopause. Additionally, women's sexual health is often conceptualized from the position of the absence of disease and dysfunction. However, consistent with definitions furthered by the World Health Organization (WHO) and World Association of Sexual Health (WAS), we believe women's sexual health is multifaceted, moving beyond a focus on reproduction to also encompass sexual function and the psychosocial dimensions of sexual health both living with and without disabling conditions and diseases. Within this lens, we present prior research that has been conducted, conclusions from these studies, implications for practice, and recommendations for future research. Thus, the paper will expand the understanding of both sexual function and psychosocial dimensions for women living with SCI.

Relative contributions of sex hormones, sex chromosomes, and gonads to sex differences in tissue gene regulation

Sex differences in physiology and disease in mammals result from the effects of three classes of factors that are inherently unequal in males and females: reversible (activational) effects of gonadal hormones, permanent (organizational) effects of gonadal hormones, and cell-autonomous effects of sex chromosomes, as well as genes driven by these classes of factors. Often, these factors act together to cause sex differences in specific phenotypes, but the relative contribution of each and the interactions among them remain unclear. Here, we used the four core genotypes (FCG) mouse model with or without hormone replacement to distinguish the effects of each class of sex-biasing factors on transcriptome regulation in liver and adipose tissues. We found that the activational hormone levels have the strongest influence on gene expression, followed by the organizational gonadal sex effect, and last, sex chromosomal effect, along with interactions among the three factors. Tissue specificity was prominent, with a major impact of estradiol on adipose tissue gene regulation and of testosterone on the liver transcriptome. The networks affected by the three sex-biasing factors include development, immunity and metabolism, and tissue-specific regulators were identified for these networks. Furthermore, the genes affected by individual sex-biasing factors and interactions among factors are associated with human disease traits such as coronary artery disease, diabetes, and inflammatory bowel disease. Our study offers a tissue-specific account of the individual and interactive contributions of major sex-biasing factors to gene regulation that have broad impact on systemic metabolic, endocrine, and immune functions.

Oral contraceptives do not modify the risk of a second attack and disability accrual in a prospective cohort of women with a clinically isolated syndrome and early multiple sclerosis

OBJECTIVE

To evaluate whether oral contraceptive (OC) use is associated with the risk of a second attack and disability accrual in women with a clinically isolated syndrome (CIS) and early multiple sclerosis (MS).

METHODS

Reproductive information from women included in the Barcelona CIS prospective cohort was collected through a self-reported cross-sectional survey. We examined the relationship of OC exposure with the risk of a second attack and confirmed Expanded Disability Status Scale of 3.0 using multivariate Cox regression models, adjusted by age, topography of CIS, oligoclonal bands, baseline brain T2 lesions, body size at menarche, smoking, and disease-modifying treatment (DMT). OC and DMT exposures were considered as time-varying variables. Findings were confirmed with sensitivity analyses using propensity score models.

RESULTS

A total of 495 women were included, 389 (78.6%) referred to ever use OC and 341 (68.9%) started OC before the CIS. Exposure to OC was not associated with a second attack (adjusted hazard ratio (aHR) = 0.73, 95% confidence interval (CI) = 0.33-1.61) or disability accrual (aHR = 0.81, 95% CI = 0.17-3.76). Sensitivity analyses confirmed these results.

CONCLUSION

OC use does not modify the risk of second attack or disability accrual in patients with CIS and early MS, once considered as a time-dependent exposure and adjusted by other potential confounders.

Rank-Rankl-Opg Axis in Multiple Sclerosis: The Contribution of Placenta

Women with multiple sclerosis (MS) can safely become pregnant and give birth, with no side effects or impediments. Pregnancy is generally accepted as a period of well-being in which relapses have a softer evolution, particularly in the third trimester. Herein, we hypothesized that the placenta, via its “secretome”, could contribute to the recognized beneficial effects of pregnancy on MS activity. We focused on a well-known receptor/ligand/decoy receptor system, such as the one composed by the receptor activator of nuclear factor-kB (RANK), its ligand (RANKL), and the decoy receptor osteoprotegerin (OPG), which have never been investigated in an integrated way in MS, pregnancy, and placenta. We reported that pregnancy at the term of gestation influences the balance between circulating RANKL and its endogenous inhibitor OPG in MS women. We demonstrated that the placenta at term is an invaluable source of homodimeric OPG. By functional studies on astrocytes, we showed that placental OPG suppresses the mRNA expression of the CCL20, a chemokine responsible for Th17 cell recruitment. We propose placental OPG as a crucial molecule for the recognized beneficial effect of late pregnancy on MS and its potential utility for the development of new and more effective therapeutic approaches.

The Eph receptor A4 plays a role in demyelination and depression-related behavior

Proper myelination of axons is crucial for normal sensory, motor, and cognitive function. Abnormal myelination is seen in brain disorders such as major depressive disorder (MDD), but the molecular mechanisms connecting demyelination with the pathobiology remain largely unknown. We observed demyelination and synaptic deficits in mice exposed to either chronic, unpredictable mild stress (CUMS) or LPS, 2 paradigms for inducing depression-like states. Pharmacological restoration of myelination normalized both synaptic deficits and depression-related behaviors. Furthermore, we found increased ephrin A4 receptor (EphA4) expression in the excitatory neurons of mice subjected to CUMS, and shRNA knockdown of EphA4 prevented demyelination and depression-like behaviors. These animal data are consistent with the decrease in myelin basic protein and the increase in EphA4 levels we observed in postmortem brain samples from patients with MDD. Our results provide insights into the etiology of depressive symptoms in some patients and suggest that inhibition of EphA4 or the promotion of myelination could be a promising strategy for treating depression.

Eighteen-month safety analysis of offspring breastfed by mothers receiving glatiramer acetate therapy for relapsing multiple sclerosis - COBRA study

Background:

Safety data on disease-modifying therapies (DMTs) for relapsing multiple sclerosis (RMS) during breastfeeding are limited.

Objective:

Assess safety outcomes for offspring breastfed by mothers undergoing glatiramer acetate (GA; Copaxone^®) treatment.

Methods:

This non-interventional, retrospective study used German Multiple Sclerosis and Pregnancy Registry data. Participants had RMS, a live birth, and received GA or no DMT during breastfeeding.

Results:

GA cohort: 58 mothers/60 offspring; matched controls: 60 mothers/60 offspring; 86.7% (GA) and 25% (control) of offspring were born to mothers who had GA at some point during pregnancy. Maternal demographics and disease activity were comparable. Annualized number of hospitalizations was similar for breastfed offspring: 0.20 (95% confidence interval: 0.09–0.31; GA) and 0.25 (0.12–0.38, controls). Proportion of offspring requiring hospitalization was comparable between cohorts (18.33% vs. 20.00%). Annualized number of antibiotic uses was similar in both cohorts (0.22, 0.10–0.33 (GA) vs. 0.17, 0.06–0.27 (controls)) The proportion of offspring requiring antibiotics was 15.00% (both cohorts). More developmental delays were identified in controls versus the GA cohort (3 (5.36%) vs. 0). Growth parameters were comparable between cohorts.

Conclusion:

Maternal intake of GA during breastfeeding did not adversely affect offspring safety outcomes assessed during the first 18 months of life.

Sexual Dimorphism in Extracellular Matrix Composition and Viscoelasticity of the Healthy and Inflamed Mouse Brain

Simple Summary

In multiple sclerosis (MS), an autoimmune disease of the central nervous system that primarily affects women, gender differences in disease course and in brain softening have been reported. It has been shown that the molecular network found between the cells of the tissue, the extracellular matrix (ECM), influences tissue stiffness. However, it is still unclear if sex influences ECM composition. Therefore, here we investigated how brain ECM and stiffness differ between sexes in the healthy mouse, and in an MS mouse model. We applied multifrequency magnetic resonance elastography and gene expression analysis for associating in vivo brain stiffness with ECM protein content in the brain, such as collagen and laminin. We found that the cortex was softer in males than in females in both healthy and sick mice. Softening was associated with sex differences in expression levels of collagen and laminin. Our findings underscore the importance of considering sex when studying the constitution of brain tissue in health and disease, particularly when investigating the processes underlying gender differences in MS.

Abstract

Magnetic resonance elastography (MRE) has revealed sexual dimorphism in brain stiffness in healthy individuals and multiple sclerosis (MS) patients. In an animal model of MS, named experimental autoimmune encephalomyelitis (EAE), we have previously shown that inflammation-induced brain softening was associated with alterations of the extracellular matrix (ECM). However, it remained unclear whether the brain ECM presents sex-specific properties that can be visualized by MRE. Therefore, here we aimed at quantifying sexual dimorphism in brain viscoelasticity in association with ECM changes in healthy and inflamed brains. Multifrequency MRE was applied to the midbrain of healthy and EAE mice of both sexes to quantitatively map regional stiffness. To define differences in brain ECM composition, the gene expression of the key basement membrane components laminin (Lama4, Lama5), collagen (Col4a1, Col1a1), and fibronectin (Fn1) were investigated by RT-qPCR. We showed that the healthy male cortex expressed less Lama4, Lama5, and Col4a1, but more Fn1 (all p < 0.05) than the healthy female cortex, which was associated with 9% softer properties (p = 0.044) in that region. At peak EAE cortical softening was similar in both sexes compared to healthy tissue, with an 8% difference remaining between males and females (p = 0.006). Cortical Lama4, Lama5 and Col4a1 expression increased 2 to 3-fold in EAE in both sexes while Fn1 decreased only in males (all p < 0.05). No significant sex differences in stiffness were detected in other brain regions. In conclusion, sexual dimorphism in the ECM composition of cortical tissue in the mouse brain is reflected by in vivo stiffness measured with MRE and should be considered in future studies by sex-specific reference values.

Incidence of neuromyelitis optica spectrum disorders in China: a large cohort study using claim data

OBJECTIVES

Population-based studies estimating the incidence of neuromyelitis optica spectrum disorders (NMOSDs) in Asia are limited, and the relationship between latitude and incidence has been scarcely investigated. We aimed to estimate the incidence of NMOSDs in Chinese adults and explore their relationship to latitude.

DESIGN

Cohort study based on data from the Urban Employee Basic Medical Insurance in China.

PARTICIPANTS

177 million people were followed from 2016 to 2017 in 20 provinces.

PRIMARY OUTCOME MEASURES

The incidence rate was estimated by Poisson distribution and reported as age-adjusted and sex-adjusted rates using the standard population.

RESULTS

There were 1313 incident NMOSD cases, with an overall incidence of 0.41 (95% CIs: 0.39 to 0.43) per 100 000 person-years. The incidence in females was higher, with a female-to-male IRR of 4.52. The incidence increased with age, peaking at 55-64 years in females and 65-74 years in males and then decreasing thereafter. The female-to-male IRRs were higher in those <55 years. The association between latitude and incidence was not statistically significant.

CONCLUSIONS

The incidence of NMOSD in Chinese adults was 0.41 per 100 000 person-years. There is no latitude gradient observed. Sex and age influence the risk of NMOSD, suggesting the role of genetic, hormonal and other related factors in the pathophysiology.

Updated Perspectives on the Challenges of Managing Multiple Sclerosis During Pregnancy

Multiple sclerosis (MS) is a chronic immune-mediated, inflammatory, and degenerative disease that is up to three times more frequent in young women. MS does not alter fertility and has no impact on fetal development, the course of pregnancy, or childbirth. The Pregnancy in Multiple Sclerosis Study in 1998 showed that pregnancy, mostly in untreated women, did not adversely affect MS, as disease activity decreased during pregnancy (although it significantly increased in the first trimester postpartum). These findings, together with the limited information available on the potential risks of fetal exposure to disease modifying treatments (DMTs), meant that women were advised to delay the onset of DMTs, stop them prior to conception, or, in case of unplanned pregnancy, discontinue them when pregnancy was confirmed. Now, many women with MS receive DMTs before pregnancy and, despite being considered a period of MS stability, up to 30% of patients could relapse in the first trimester postpartum. Factors associated with an increased risk of relapse and disability during pregnancy and postpartum include relapses before and during pregnancy, a greater disability at the time of conception, the occurrence of relapses after DMT cessation before conception, and the use of high-efficacy DMTs before conception, especially natalizumab or fingolimod. Strategies to prevent postpartum activity are needed in some patients, but consensus is lacking regarding the therapeutic strategies for women with MS of a fertile age. This, along with the increasing number of DMTs, means that the decision-making processes in aspects related to family planning and therapeutic strategies before, during, and after pregnancy are increasingly more complex. The purpose of this review is to provide an update on pregnancy-related issues in women with MS, including recommendations for counseling, general management, use of DMTs in pre-pregnancy, pregnancy, and postpartum periods, and breastfeeding-related aspects of DMTs.

Sex Differences in Neurodegeneration: The Role of the Immune System in Humans

Growing evidence supports significant involvement of immune dysfunction in the etiology of neurodegenerative diseases, several of which also display prominent sex differences across prevalence, pathology, and symptomology. In this review, we summarize evidence from human studies of established and recent findings of sex differences in multiple sclerosis, Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis and discuss how sex-specific central nervous system innate immune activity could contribute to downstream sex differences in these diseases. We examine human genomic and transcriptomics studies in each neurodegenerative disease through the lens of sex differences in the neuroimmune system and highlight the importance of stratifying sex in clinical and translational research studies. Finally, we discuss the limitations of the existing studies and outline recommendations for further advancing sex-based analyses to uncover novel disease mechanisms that could ultimately help treat both sexes.

A higher burden of multiple sclerosis genetic risk confers an earlier onset

BACKGROUND

Age at onset of multiple sclerosis (MS) is an objective, influential predictor of the evolution of MS independent of disease duration.

OBJECTIVES

Determine the influence of MS genetic predisposition on age of onset.

METHODS

We conducted a comprehensive investigation of MS risk variants and age at onset in 3495 non-Latinx white individuals, including for combinations of HLA-DRB1*15:01 alleles and quintiles of an unweighted genetic risk score (GRS) for 198 of 200 autosomal MS risk variants that reside outside the major histocompatibility complex.

RESULTS

The mean age at onset was 32 years, 29% were male, and 46% were HLA-DRB1*15:01 carriers. For those with the greatest genetic risk burden (the highest GRS quintile with two HLA-DRB1*15:01 alleles) were on average 5 years younger at onset (p = 0.002) than those with the lowest genetic risk burden (the lowest GRS quintile with no HLA-DRB1*15:01 alleles). There was a strong inverse relationship between the MS genetic risk burden and age at onset of MS (p < 5 × 10^-8).

CONCLUSION

We demonstrate a significant gradient between elevated MS genetic risk burden and an earlier onset of MS, suggesting that a higher MS genetic risk burden accelerates onset of the disease.

Sex-specific signatures of intrinsic hippocampal networks and regional integrity underlying cognitive status in multiple sclerosis

The hippocampus is an anatomically compartmentalized structure embedded in highly wired networks that are essential for cognitive functions. The hippocampal vulnerability has been postulated in acute and chronic neuroinflammation in multiple sclerosis, while the patterns of occurring inflammation, neurodegeneration or compensation have not yet been described. Besides focal damage to hippocampal tissue, network disruption is an important contributor to cognitive decline in multiple sclerosis patients. We postulate sex-specific trajectories in hippocampal network reorganization and regional integrity and address their relationship to markers of neuroinflammation, cognitive/memory performance and clinical severity. In a large cohort of multiple sclerosis patients (n = 476; 337 females, age 35 ± 10 years, disease duration 16 ± 14 months) and healthy subjects (n = 110, 54 females; age 34 ± 15 years), we utilized MRI at baseline and at 2-year follow-up to quantify regional hippocampal volumetry and reconstruct single-subject hippocampal networks. Through graph analytical tools we assessed the clustered topology of the hippocampal networks. Mixed-effects analyses served to model sex-based differences in hippocampal network and subfield integrity between multiple sclerosis patients and healthy subjects at both time points and longitudinally. Afterwards, hippocampal network and subfield integrity were related to clinical and radiological variables in dependency of sex attribution. We found a more clustered network architecture in both female and male patients compared to their healthy counterparts. At both time points, female patients displayed a more clustered network topology in comparison to male patients. Over time, multiple sclerosis patients developed an even more clustered network architecture, though with a greater magnitude in females. We detected reduced regional volumes in most of the addressed hippocampal subfields in both female and male patients compared to healthy subjects. Compared to male patients, females displayed lower volumes of para- and presubiculum but higher volumes of the molecular layer. Longitudinally, volumetric alterations were more pronounced in female patients, which showed a more extensive regional tissue loss. Despite a comparable cognitive/memory performance between female and male patients over the follow-up period, we identified a strong interrelation between hippocampal network properties and cognitive/memory performance only in female patients. Our findings evidence a more clustered hippocampal network topology in female patients with a more extensive subfield volume loss over time. A stronger relation between cognitive/memory performance and the network topology in female patients suggests greater entrainment of the brain’s reserve. These results may serve to adapt sex-targeted neuropsychological interventions.

Gender-Related Differences in Prodromal Multiple Sclerosis Characteristics: A 7-Year Observation Study

Increasing evidence supports the observation that multiple sclerosis (MS) has a preclinical period, with various prodromal signs and symptoms more frequently represented in patients with confirmed MS many years later. Considering the apparent gender differences in the incidence and clinical course of MS, it remains unclear whether it could be reflected in prodromal symptom features. This study aimed to compare a broad spectrum of prodromal signs and symptoms between males and females in the 7-year period before the definite diagnosis of MS. Data came from the central register of the national payer of services, financed under the public healthcare system in Poland. They covered a 7-year period of patient health record claims, from 2009 to 2016. The following groups of symptoms were significant with women: musculoskeletal (p < 0.001), ophthalmic (p < 0.001), laryngological (p < 0.001), digestive system (p < 0.001), urinary tract (p < 0.001), mental (p < 0.001), cardiovascular (p < 0.001), complaints and headaches (p < 0.001). There was also a weak correlation with head injuries (p = 0.03) while dermatological and reproductive system complaints did not appear to be significant (p < 0.05). For males, the following groups of symptoms were significant: musculoskeletal (p < 0.001), ophthalmic (p < 0.001), laryngological (p = 0.007), cardiovascular system symptoms (p < 0.001), and headaches (p < 0.001). Interestingly, reproductive system problems were overrepresented in the male population (p = 0.008). There was no significant correlation with MS risk for dermatological, digestive, urinary, and mental complaints. Similarly, head injuries were not significant. Our results shed more light on well-known differences in the epidemiological and clinical characteristics between sexes in multiple sclerosis, and show differences in prodromal complaints before MS onset.

Possible Markers of Venous Sinus Pressure Elevation in Multiple Sclerosis: Correlations with Gender and Disease Progression

BACKGROUND

In a previous study, multiple sclerosis (MS) was found to be associated with an increase in intracranial arterial pulsation volume and a reduction in venous sinus compliance, affecting pulsation dampening. There was a suggestion that the reduction in compliance of the sagittal sinus in MS was caused by an increase in venous pressure, secondary to transverse sinus stenosis. Some differences were noted depending on the gender of the patients, however, the original study was relatively underpowered for further sub-classification. The purpose of the current study is to enroll a larger number of patients to allow sub-classification on gender and disease type to further evaluate the markers of possible venous pressure alteration.

METHODS

103 patients with MS were prospectively recruited from an MS clinic and compared to 50 matched non-MS patients. Using 3DT1 post contrast images, the sagittal sinus cross-sectional area was measured. The narrowest portion of the transverse sinuses was located and the cross sectional areas and wetted circumferences were measured to calculate the minimum hydraulic and effective diameters. The jugular bulb heights were measured. Voxel wise brain morphometry was performed to evaluate atrophy. Statistical analysis was performed using non-parametric methods and was assessed using α≤0.05.

RESULTS

Compared to controls, the MS patients' sagittal sinuses were 23% larger in cross-section (p<0.0001), the transverse sinuses had an average effective stenosis of 39% by area (p<0.0001) and there was a 62% increase in jugular bulb height (p=0.0001). The MS patients showed a reduction in normalized grey matter volume of 2.8% (p= 0.0001). Males with MS showed worse outcomes compared to females, with an increased EDSS and grey matter loss and had a 23% larger sagittal sinus area (p=0.02), 22% higher jugular bulb height (p=0.03) but a lower transverse sinus stenosis percentage (19% vs 48%, p<0.0001). Progressive forms of MS also had worse outcomes and had a 19% larger sagittal sinus area (p=0.04) compared to relapsing remitting MS.

CONCLUSION

In this larger cohort, worse outcomes in both males and progressive forms of MS were associated with larger sagittal sinuses. The possible cause of the altered sinus pressure in females was narrower transverse sinuses. In males, higher jugular bulbs may be associated with increased venous sinus pressure.

Diversity of Reactive Astrogliosis in CNS Pathology: Heterogeneity or Plasticity?

Astrocytes are essential for the development and homeostatic maintenance of the central nervous system (CNS). They are also critical players in the CNS injury response during which they undergo a process referred to as "reactive astrogliosis." Diversity in astrocyte morphology and gene expression, as revealed by transcriptional analysis, is well-recognized and has been reported in several CNS pathologies, including ischemic stroke, CNS demyelination, and traumatic injury. This diversity appears unique to the specific pathology, with significant variance across temporal, topographical, age, and sex-specific variables. Despite this, there is limited functional data corroborating this diversity. Furthermore, as reactive astrocytes display significant environmental-dependent plasticity and fate-mapping data on astrocyte subsets in the adult CNS is limited, it remains unclear whether this diversity represents heterogeneity or plasticity. As astrocytes are important for neuronal survival and CNS function post-injury, establishing to what extent this diversity reflects distinct established heterogeneous astrocyte subpopulations vs. environmentally dependent plasticity within established astrocyte subsets will be critical for guiding therapeutic development. To that end, we review the current state of knowledge on astrocyte diversity in the context of three representative CNS pathologies: ischemic stroke, demyelination, and traumatic injury, with the goal of identifying key limitations in our current knowledge and suggesting future areas of research needed to address them. We suggest that the majority of identified astrocyte diversity in CNS pathologies to date represents plasticity in response to dynamically changing post-injury environments as opposed to heterogeneity, an important consideration for the understanding of disease pathogenesis and the development of therapeutic interventions.