Search

Multiple sclerosis (MS) is a progressive inflammatory demyelinating disease of the CNS. Increasing evidence suggests that vulnerable neurons in MS exhibit fatal metabolic exhaustion over time, a phenomenon hypothesized to be caused by chronic hyperexcitability. Axonal Kv7 (outward-rectifying) and oligodendroglial Kir4.1 (inward-rectifying) potassium channels have important roles in regulating neuronal excitability at and around the nodes of Ranvier. Here, we studied the spatial and functional relationship between neuronal Kv7 and oligodendroglial Kir4.1 channels and assessed the transcriptional and functional signatures of cortical and retinal projection neurons under physiological and inflammatory demyelinating conditions. We found that both channels became dysregulated in MS and experimental autoimmune encephalomyelitis (EAE), with Kir4.1 channels being chronically downregulated and Kv7 channel subunits being transiently upregulated during inflammatory demyelination. Further, we observed that pharmacological Kv7 channel opening with retigabine reduced neuronal hyperexcitability in human and EAE neurons, improved clinical EAE signs, and rescued neuronal pathology in oligodendrocyte-Kir4.1-deficient (OL-Kir4.1-deficient) mice. In summary, our findings indicate that neuron-OL compensatory interactions promoted resilience through Kv7 and Kir4.1 channels and identify pharmacological activation of nodal Kv7 channels as a neuroprotective strategy against inflammatory demyelination.

The Major Histocompatibility Complex (MHC) makes the largest genetic contribution to multiple sclerosis (MS) susceptibility, with 32 independent effects across the region explaining 20% of the heritability in European populations. Variation is high across populations with allele frequency differences and population-specific risk alleles identified. We sought to identify MHC-specific MS susceptibility variants and assess the effect of ancestral risk modification within 2652 Latinx and Hispanic individuals as well as 2435 Black and African American individuals. We have identified several novel susceptibility alleles which are rare in European populations including HLA-B*53:01, and we have utilized the differing linkage disequilibrium patterns inherent to these populations to identify an independent role for HLA-DRB1*15:01 and HLA-DQB1*06:02 on MS risk. We found a decrease in Native American ancestry in MS cases vs controls across the MHC, peaking near the previously identified MICB locus with a decrease of ~5.5% in Hispanics and ~0.4% in African Americans. We have identified several susceptibility variants, including within the MICB gene region, which show global ancestry risk modification and indicate ancestral differences which may be due in part to correlated environmental factors. We have also identified several susceptibility variants for which MS risk is modified by local ancestry and indicate true ancestral genetic differences; including HLA-DQB1*06:02 for which MS risk for European allele carriers is almost two times the risk for African allele carriers. These results validate the importance of investigating MS susceptibility at an ancestral level and offer insight into the epidemiology of MS phenotypic diversity.

BackgroundDiet is a modifiable risk factor that may influence cognition in people with HIV.ObjectivesWe examined the association between dietary intake and cognition in women with HIV (WWH) and HIV-seronegative women.MethodsAn 18-item dietary National Cancer Institute screener was completed by 729 WWH and 346 HIV-seronegative Women's Interagency HIV Study participants. Daily intake frequencies of processed meats, sweet beverages, fish, whole milk, and vegetables were calculated. Participants completed biennial neuropsychological (NP) testing. NP domains included attention/working memory, executive function, processing speed, memory, learning, fluency, and motor function. NP impairment was defined as demographically adjusted T-scores (mean = 50; SD = 10) ≤40 at ≥1 visit after completing the dietary screener. Multivariable logistic regression, stratified by HIV serostatus, examined associations between intake frequency tertile (referent = lowest intake) and NP performance.ResultsDietary intake frequencies of individual food line items were similar between WWH and HIV-seronegative women, except for sweet beverages, for which HIV-seronegative women reported higher intake frequencies than WWH (P values

Immunologic function is an important determinant of cognition. Here we examined the contribution of early immune signatures to cognitive performance among HIV-infected, virally suppressed women (HIV+VS) and in HIV-uninfected (HIV-) women. Specifically, we measured serum inflammatory markers, developed combinatory immune signatures, and evaluated their associations with cognition. Forty-nine HIV+VS women in the Women's Interagency HIV Study (WIHS) who achieved viral suppression shortly after effective antiretroviral therapy (ART) initiation, and 56 matched HIV- women were selected. Forty-two serum inflammatory markers were measured within 2 years of effective ART initiation for HIV+VS women, and at an initial timepoint for HIV- women. The same inflammatory markers were also measured approximately 1, 7, and 12 years later for all women. Of the 105 women with complete immune data, 83 (34 HIV+VS, 49 HIV-) also had cognitive data available 12 years later at ≥1 time points (median = 3.1). We searched for combinatory immune signatures by adapting a dynamic matrix factorization analytic method that builds upon Tucker decomposition followed by Ingenuity® Pathway Analysis to facilitate data interpretation. Seven combinatory immune signatures emerged based on the Frobenius residual. Three signatures were common between HIV+VS and HIV- women, while four signatures were unique. These inflammatory signatures predicted subsequent cognitive performance in both groups using mixed-effects modeling, but more domain-specific associations were significant in HIV+VS than HIV- women. Leukocyte influx into brain was a major contributor to cognitive function in HIV+VS women, while T cell exhaustion, inflammatory response indicative of depressive/psychiatric disorders, microglial activity, and cytokine signaling predicted both global and domain-specific performance for HIV- women. Our findings suggest that immune signatures may be useful diagnostic, prognostic, and immunotherapeutic targets predictive of subsequent cognitive performance. Importantly, they also provide insight into common and distinct inflammatory mechanisms underlying cognition in HIV- and HIV+VS women.

Multiple sclerosis is a heterogeneous disease with an unpredictable course and a wide range of severity; some individuals rapidly progress to a disabled state whereas others experience only mild symptoms. Though genetic studies have identified variants that are associated with an increased risk of developing multiple sclerosis, no variants have been consistently associated with multiple sclerosis severity. In part, the lack of findings is related to inherent limitations of clinical rating scales; these scales are insensitive to early degenerative changes that underlie disease progression. Optical coherence tomography imaging of the retina and low-contrast letter acuity correlate with and predict clinical and imaging-based outcomes in multiple sclerosis. Therefore, they may serve as sensitive phenotypes to discover genetic predictors of disease course. We conducted a set of genome-wide association studies of longitudinal structural and functional visual pathway phenotypes in multiple sclerosis. First, we assessed genetic predictors of ganglion cell/inner plexiform layer atrophy in a discovery cohort of 374 patients with multiple sclerosis using mixed-effects models adjusting for age, sex, disease duration, optic neuritis and genetic ancestry and using a combination of single-variant and network-based analyses. For candidate variants identified in discovery, we conducted a similar set of analyses of ganglion cell/inner plexiform layer thinning in a replication cohort (n = 376). Second, we assessed genetic predictors of sustained loss of 5-letters in low-contrast letter acuity in discovery (n = 582) using multivariable-adjusted Cox proportional hazards models. We then evaluated candidate variants/pathways in a replication cohort. (n = 253). Results of both studies revealed novel subnetworks highly enriched for connected genes in early complement activation linked to measures of disease severity. Within these networks, C3 was the gene most strongly associated with ganglion cell/inner plexiform layer atrophy (P = 0.004) and C1QA and CR1 were top results in analysis of sustained low-contrast letter acuity loss. Namely, variant rs158772, linked to C1QA, and rs61822967, linked to CR1, were associated with 71% and 40% increases in risk of sustained LCLA loss, respectively, in meta-analysis pooling discovery and replication cohorts (rs158772: hazard ratio: 1.71; 95% confidence interval 1.30-2.25; P = 1.3 × 10-4; rs61822967: hazard ratio: 1.40; 95% confidence interval: 1.16-1.68; P = 4.1 × 10-4). In conclusion, early complement pathway gene variants were consistently associated with structural and functional measures of multiple sclerosis severity. These results from unbiased analyses are strongly supported by several prior reports that mechanistically implicated early complement factors in neurodegeneration.

Background: Little is known about how multiple sclerosis (MS) presents in Hispanic/Latinx (HL) people with MS (pwMS). Objective: Compare age at onset (AAO) and onset severity between HL versus non-Hispanic White (NHW) pwMS. Methods: A cross-sectional study leveraged the MS PATHS registry spanning seven US tertiary care institutions. HL was subcategorized as HL White (HLW) and HL Other (HLO; all other races). Multivariable models examined relationships between ethnoracial variables and AAO and self-reported presenting disease course. Models were repeated restricting to those born ⩾1970. Results: The study population included 8231 pwMS, including 540 HL (200 HLW, 340 HLO). The sex distribution did not differ across ethnoracial subgroups. From the statistical models (1) HLO pwMS had an earlier AAO and a higher prevalence of initial progressive disease course than NHW pwMS; (2) among all HL pwMS, irrespective of race, AAO did not differ by sex or between relapsing and progressive MS at onset. In younger HLO adults (born ⩾1970), those with progressive MS at onset had an earlier AAO than those with relapsing MS; and (3) in HL pwMS there was no sex-bias in presenting disease course. Discussion: Distinct differences in the presentation of MS in HL compared with NHW individuals were observed. [ABSTRACT FROM AUTHOR]

Background: Retrograde trans-synaptic degeneration (TSD) following retro-chiasmal pathology, typically retro-geniculate in multiple sclerosis (MS), may manifest as homonymous hemi-macular atrophy (HHMA) of the ganglion cell/inner plexiform layer (GCIPL). Objective: To determine the frequency, association with clinical outcomes, and retinal and radiological features of HHMA in people with MS (PwMS). Methods: In this cross-sectional study, healthy controls (HC) and PwMS underwent retinal optical coherence tomography scanning. For quantitative identification of HHMA, a normalized asymmetry ratio was used, and its normative cutoffs were established from the HC. HHMA PwMS were propensity score matched 1:2 to non-HHMA PwMS. Mixed-effects linear regression models were used in analyses. Results: Based on normative data from 238 HC (466 eyes), 79 out of 942 PwMS exhibited HHMA (8.4%; 143 eyes). Compared to non-HHMA eyes from matched PwMS (158 PwMS; 308 eyes), HHMA eyes had lower average GCIPL (diff: −5.7 μm (95% CI −7.6 to −3.8); p < 0.001) but also inner nuclear layer (diff: −0.9 μm (95% CI −1.6 to −0.1); p = 0.02), and outer nuclear layer (diff: −1.9 μm (95% CI −3.4 to −0.4); p = 0.02) thicknesses; in further analyses, these differences were exclusive to the homonymous side of HHMA. HHMA participants also exhibited higher expanded disability status scale scores (diff: 0.5 (95% CI 0.1 to 0.9); p = 0.02), worse 100% and 2.5% visual acuity scores (diff: −3.2 (95% CI −4.1 to −1.0); p = 0.002, −5.4 (95% CI −7.5 to −3.5); p < 0.001), and higher frequency of microcystoid macular changes (10.1% vs. 3.2%; p = 0.03) compared to non-HHMA participants. Conclusions: HHMA, possibly as a marker of TSD, may signify higher disability in MS. [ABSTRACT FROM AUTHOR]

Author(s): Martina Absinta [sup.1] [sup.2] [sup.3] , Dragan Maric [sup.4] , Marjan Gharagozloo [sup.1] , Thomas Garton [sup.1] , Matthew D. Smith [sup.1] , Jing Jin [sup.1] , Kathryn C. [...], Multiple sclerosis (MS) lesions that do not resolve in the months after they form harbour ongoing demyelination and axon degeneration, and are identifiable in vivo by their paramagnetic rims on MRI scans.sup.1-3. Here, to define mechanisms underlying this disabling, progressive neurodegenerative state.sup.4-6 and foster development of new therapeutic agents, we used MRI-informed single-nucleus RNA sequencing to profile the edge of demyelinated white matter lesions at various stages of inflammation. We uncovered notable glial and immune cell diversity, especially at the chronically inflamed lesion edge. We define &apos;microglia inflamed in MS&apos; (MIMS) and &apos;astrocytes inflamed in MS&apos;, glial phenotypes that demonstrate neurodegenerative programming. The MIMS transcriptional profile overlaps with that of microglia in other neurodegenerative diseases, suggesting that primary and secondary neurodegeneration share common mechanisms and could benefit from similar therapeutic approaches. We identify complement component 1q (C1q) as a critical mediator of MIMS activation, validated immunohistochemically in MS tissue, genetically by microglia-specific C1q ablation in mice with experimental autoimmune encephalomyelitis, and therapeutically by treating chronic experimental autoimmune encephalomyelitis with C1q blockade. C1q inhibition is a potential therapeutic avenue to address chronic white matter inflammation, which could be monitored by longitudinal assessment of its dynamic biomarker, paramagnetic rim lesions, using advanced MRI methods. Single-nucleus transcriptomics defines a diverse set of immune and glial cells at the chronically inflamed leading edge of demyelinated white matter lesions in patients with multiple sclerosis.

Introduction Multiple sclerosis (MS) is a chronic demyelinating disorder characterized by inflammation and neurodegeneration (1). Both genetic and environmental factors play a role in the etiopathogenesis of this disease (2-4). [...], Multiple sclerosis (MS) is an inflammatory demyelinating disorder of the CNS. Bile acids are cholesterol metabolites that can signal through receptors on cells throughout the body, including in the CNS and the immune system. Whether bile acid metabolism is abnormal in MS is unknown. Using global and targeted metabolomic profiling, we identified lower levels of circulating bile acid metabolites in multiple cohorts of adult and pediatric patients with MS compared with controls. In white matter lesions from MS brain tissue, we noted the presence of bile acid receptors on immune and glial cells. To mechanistically examine the implications of lower levels of bile acids in MS, we studied the in vitro effects of an endogenous bile acid, tauroursodeoxycholic acid (TUDCA), on astrocyte and microglial polarization. TUDCA prevented neurotoxic (A1) polarization of astrocytes and proinflammatory polarization of microglia in a dose-dependent manner. TUDCA supplementation in experimental autoimmune encephalomyelitis reduced the severity of disease through its effects on G protein-coupled bile acid receptor 1 (GPBAR1). We demonstrate that bile acid metabolism was altered in MS and that bile acid supplementation prevented polarization of astrocytes and microglia to neurotoxic phenotypes and ameliorated neuropathology in an animal model of MS. These findings identify dysregulated bile acid metabolism as a potential therapeutic target in MS.

Background: There is a paucity of studies examining quality of life (QoL) in people with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). Methods: A cross-sectional, online, self-administered survey was distributed. Data elements included demographic and clinical characteristics, and QoL in Neurological Disorders (Neuro-QoL) short form questionnaires. Neuro-QoL domain scores were compared to reference populations, yielding standardized T-scores. Symptom severity was categorized as mild, moderate, or severe, using standard Neuro-QoL cut points. Results: A total of 259 participants completed the survey. Neuro-QoL domain impairment was present in a significant proportion of respondents (anxiety: 58.1%, depression: 30.7%, stigma 29.8%, cognition: 58.5%, social function: 57.7%). T-scores were significantly worse than the reference population for anxiety (p<0.001), stigma (p=0.005), cognitive function (p<0.001) and social interactions (p<0.001). There was no clear association between QoL domains and demographics, disease-modifying therapy class, or type of clinical presentation. A relapsing vs monophasic disease course was associated with worse anxiety, stigma, cognition, and social interactions (p<0.05). Conclusion: People with MOGAD may exhibit impairment in multiple domains of QoL. Practicing clinicians should be aware of this burden in MOGAD. Further research is needed to better understand factors associated with QoL impairment in MOGAD. [ABSTRACT FROM AUTHOR]