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Increasing evidence indicates an involvement of B cells in multiple sclerosis (MS). However, little is known about antigenic targets recognized by antibodies present in blood and cerebrospinal fluid (CSF) of MS patients. This study was therefore aimed at identifying the antigen reactivity of antibodies present in CSF and compares the identified antibody profile with that of the serum of the same patient using cDNA phage display. Selection rounds on paired CSF and serum of this patient identified 13 antigenic targets of which 5 were enriched by serum antibodies and 2 were identified by CSF antibodies. Interestingly, the six remaining antigenic targets were shown to be recognized by both CSF and serum antibodies. These findings point towards both common as well as distinct antibody profiles in CSF and serum of MS patients. [ABSTRACT FROM AUTHOR]

We applied a cDNA phage display method called serological antigen selection (SAS) to identify immunogenic targets that evoke an autoantibody response in the serum of multiple sclerosis (MS) patients. This method involves the display of a cDNA expression library, in this study a MS brain library, on filamentous phage and subsequent selection using patient immunoglobulin G (IgG). To apply the SAS technology for autoantibodies in the serum of MS patients, an optimization was necessary to deplete cDNA products that encode IgG fragments derived from B cells present in the MS brain plaques. We describe a differential screening procedure in which positive selection rounds on MS serum and negative selection rounds on healthy control serum were alternated to optimize the selection procedure. As a result, a substantial decrease of IgG-displaying phage clones was observed after each negative selection round, thereby preventing an overgrowth of IgG-displaying phage clones. Our depletion strategy was therefore successful in preventing the enrichment of IgG-displaying phage clones. This approach will facilitate the identification of possible MS-related antigens. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To determine whether either of the gene variants associated with age-related macular degeneration is associated with coronary artery disease (CAD). PATIENTS AND METHODS: This study consisted of 493 patients who underwent clinically indicated coronary angiography between June 1, 1998, and January 1, 1999. The Y402H variant of the complement factor H (CFH) gene and the A69S variant of the LOC387715 gene locus were examined by restriction fragment length polymorphism. Multiple logistic regression models were used to assess the association of CFH and LOC gene variants with CAD. Covariates with well-established associations with CAD were also evaluated. RESULTS: Seventy patients (14%) were homozygous for the histidine variant (HH) of CFH, 237 (48%) were heterozygous for the histidine variant (HY), and 186 (38%) were homozygous for the tyrosine variant (YY). Three hundred eight patients (62%) were homozygous for the alanine allele of LOC387715, 170 (34%) were heterozygous for Ala and Ser alleles, and 15 (3%) were homozygous for the serine variant. The overall association of the CFH genotype with CAD was not statistically significant (P=.08). However, some evidence (P=-.046) suggested that CAD was increased for the HH genotype compared to the homozygous wild-type YY genotype (odds ratio, 1.95; 95% confidence interval, 1.01-3.76). Male sex, hypertension, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and age were other variables that demonstrated significant associations with CAD. The overall effect of the LOC genotype was not statistically significant (P=-.06). Heterozygosity for the serine variant was (P=-.02) associated with the absence of CAD vs the AS genotype (odds ratio, 0.59; confidence interval, 0.38-0.91; P=-.02). CONCLUSION: The CFH genotype may have an independent association with CAD, although our evidence did not show statistical significance. Controlling for known risk factors, the age-related macular degeneration-associated HH variant appears to be associated with CAD. The LOC387715 gene may also play a role in CAD. [ABSTRACT FROM AUTHOR]

A non-invasive model-based approach to the estimation of sinus node dynamic properties is proposed. The model exploits the spontaneous beat-to-beat variability of heart period and systolic arterial pressure and the sampled respiration, thus surrogating the information from direct measures of neural activity. The residual heart period variability not related to baroreflex, to direct effects of respiration and to low frequency influences independent of baroreflex, is interpreted as the effect of the dynamic properties of the sinus node and modelled as a regression of the RR interval over its previous value. Therefore the sinus node transfer function is modelled by means of a filter with a real pole z = mu (and a zero in the origin). It was found that: first, in young healthy subjects the nodal tissue responded as a low-pass filter with mu = 0.76 +/- 0.12 (mean +/- SD); secondly, ageing did not significantly modify either its shape or gain at 0 Hz; thirdly, in heart transplant recipients, the dynamic transduction properties were lost (all-pass filter, p = 0.06 +/- 0.16, p < 0.001); fourthly, low-dose atropine left the sinus node dynamic properties unmodified; fifthly, high-dose atropine affected the dynamic transduction properties by increasing the gain at 0 Hz and rendering steeper its roll-off (the percent increase of mu with respect to baseline was 18.3 +/- 22.3, p < 0.05). [ABSTRACT FROM AUTHOR]

Severe congestive heart failure (CHF) is associated with Cheyne-Stokes (C-S) respiration, which may be an index of poorer prognosis. The mechanisms linking C-S respiration to poorer functional status and prognosis in patients with CHF are unknown. We tested the hypothesis that C-S respiration increases muscle sympathetic nerve activity (MSNA) in 9 patients with CHF. Oxygen saturation was 96 +/- 1% during normal breathing and 91 +/- 1% after the apneic episodes (p < 0.05). Mean blood pressure was 79 +/- 8 mm Hg during normal breathing and 85 +/- 8 mm Hg during C-S respiration (p = 0.001). C-S respiration increased MSNA burst frequency (from 45 +/- 5 bursts/min during normal breathing to 50 +/- 5 bursts/min during C-S respiration; p < 0.05) and total integrated nerve activity (to 117 +/- 7%; p < 0.05). We also studied an additional 5 patients in whom C-S breathing was constant, without any periods of spontaneous normal breathing. In these patients, MSNA was higher (65 +/- 5 bursts/min) than MSNA in patients in whom C-S breathing was only intermittent (45 +/- 5 bursts/min; p < 0.05). In all 14 patients, the effects of different phases of C-S respiration were examined. MSNA was highest during the second half of each apnea (increasing to 152 +/- 14%; p < 0.01) and blood pressure was highest during mild hyperventilation occurring after termination of apnea (p < 0.0001). We conclude that C-S respiration decreases oxygen saturation, increases MSNA, and induces transient elevations in blood pressure in patients with CHF. [ABSTRACT FROM AUTHOR]

Introduction: Complex sleep apnea syndrome (CompSAS) presumably involves unstable ventilatory control mechanisms, possibly including cortical brain arousal indexed by NREM cyclic alternating pattern (CAP) sleep microarchitecture. CompSAS has been associated with opiate use, but may also be idiopathic or associated with underlying cardiac disease. We aimed to determine whether cortical arousal propensity indexed by NREM CAP differed between CompSAS opiate users (OU) and non-opiate users (NOU), and OSA controls. Materials and methods: A retrospective analysis of clinical and diagnostic polysomnographic data of 39 consecutive CompSAS patients (18 OU, 21 NOU) and 18 OSA controls without CompSAS matched for age, gender, body mass index, and polysomnographic apnea-hypopnea index (AHI) was performed. Polysomnograms were manually analyzed for CAP and log transformed CAP A Ratio Index (ARI, with higher values indicating higher sleep-preservation propensity) according to standard methods using Hypnolab scoring software (ATES Medica Labs, Verona, Italy). Groups were compared utilizing Wilcoxon Rank Sum tests, and multivariable regression was performed to determine associations between predictor variables and CompSAS. Results: AHI (p = 0.66) and arousal indices (p = 0.42) were similar between OU, NOU, and OSA controls. CAP rate was lower in OU than NOU or OSA controls (66 vs. 77 vs. 77, p = 0.13). OU had lower CAP A1 and higher A2 indices (A1: 52 vs. 94 vs. 88, p = 0.096; A2: 39.7 vs. 24.0 vs. 21.1, p = 0.068), resulting in a signifi cantly lower ARI in OU (p = 0.02) with ARI below 0.55 associated with CompSAS (p = 0.0026). Conclusion: CompSAS OU demonstrated a higher cortical arousal propensity when compared to CompSAS NOU and OSA controls, resulting from reduced A1 (slow, sleep promoting) and higher A2 (fast, sleep fragmenting) CAP rhythms. Our fi ndings suggest that opiates alter cortical arousal mechanisms that could induce central apnea, possibly causing postarousal/sleep-onset central apneas during positive airway pressure treatment. [Copyright &y& Elsevier]

Objective: To discover antibody biomarkers that can predict a lack of response to first-line therapy in rheumatoid arthritis (RA) patients., Methods: Two RA cDNA phage display libraries were screened for novel antibodies in baseline RA sera from the Care in early RA (CareRA) trial, differentiating between patients who did or did not reach remission after first-line therapy (n=20 each). Antibody reactivity to identified University Hasselt (UH)-RA antigens was validated in baseline samples from 136 additional CareRA participants. The novel antibodies' potential to predict failure to reach remission or low disease activity (LDA), according to the Disease Activity Score 28-joint C-reactive protein/erythrocyte sedimentation rate (DAS28CRP/ESR) and Clinical/Simplified Disease Activity Index (CDAI/SDAI), was studied by multivariate analyses. The presence of the antibody targets in RA synovial tissue and the fibroblast-like synoviocyte (FLS) cell line SW982 was determined by immunofluorescence., Results: We identified antibodies to 41 novel antigens. Antibodies against any of three antigens, UH-RA.305/318/329, discriminated between RA patients not reaching week (w)8 DAS28CRP remission and those that did (36% vs 13%,p=0.0031). In all patients, anti-UH-RA.305/318/329 antibody reactivity was associated with failure to reach week 8 DAS28CRP and DAS28ESR remission (OR 3.63,p=0.0031; OR 2.92,p=0.016; respectively), SDAI/CDAI sustained remission (OR 5.59,p=0.039 for both) and DAS28CRP and DAS28ESR sustained LDA (OR 3.7,p=0.009; OR 2.76,p=0.042; respectively). In rheumatoid factor/anti-citrullinated protein antibody (RF/ACPA) seronegative patients, these antibodies were strongly associated with failure to achieve week 8 DAS28CRP remission (OR 17.3,p=0.0029). Anti-UH-RA.305/329 antibodies were shown to target FLS in RA synovial tissue and SW982 cells., Conclusion: We identified three antibody biomarkers that are associated with failure to achieve remission/LDA after first-line RA therapy., Competing Interests: Competing interests: PVandormael, VS and PVerschueren have a patent application filed on the biomarkers described in this report., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

The water channel aquaporin 4 (AQP4) contributes to water flow and waste removal across the blood-brain barrier and its levels, organization and localization are perturbed in various neurological diseases, including Alzheimer's Disease. This renders AQP4 a potentially valuable therapeutic target. However, most functional assays aimed at identifying modulators of AQP4 function are performed with primary rodent cells and do not consider inter-cellular variations in AQP4 abundance and presentation. To address this, we have established and applied a robust live cell microscopy assay that captures the contribution of AQP4 in the osmotically driven (de-)quenching of the vital dye Calcein-AM with single-cell resolution. Using human astrocytoma cells, we found that performing measurements on cellular regions instead of whole fields of view yielded a more sensitive readout of the osmotic response, which correlated with AQP4 abundance. Stable co-expression of the two major AQP4 isoforms, but not of the individual isoforms, provoked a faster adaptation to osmotic changes, while siRNA-mediated knockdown of AQP4 had the opposite effect. Post-hoc correlation with the canonical membrane marker CD44 revealed that the speed of the osmotic response scaled with AQP4 membrane enrichment. Coating the substrate with laminin promoted AQP4 membrane enrichment, while cell confinement with fixed-size micropatterns further increased the speed of osmoregulation, underscoring the influence of extracellular factors. The osmotic response of primary fetal astrocytes and human iPSC-derived astrocyte models was comparable to AQP4-deficient astrocytoma cells, in line with their low AQP4 levels and indicative of their immature state. In conclusion, a correlative single-cell approach based on the quantification of Calcein-AM quenching capacity, AQP4 abundance and AQP4 membrane enrichment, allows resolving osmoregulation in a more sensitive manner and reveals heterogeneity between and within human astrocyte (-like) cultures, which could prove crucial for future screens aimed at identifying AQP4 modulators., (© 2024 International Society for Advancement of Cytometry.)

Traumatic spinal cord injury (SCI) is a severe condition leading to long-term impairment of motor, sensory, and autonomic functions. Following the initial injury, a series of additional events is initiated further damaging the spinal cord. During this secondary injury phase, both an inflammatory and immune modulatory response are triggered that have damaging and anti-inflammatory properties, respectively. The proinflammatory cytokine macrophage migration inhibitory factor (MIF) and its receptor CD74 have been extensively studied in traumatic SCI. MIF expression is increased in spinal cord tissue after experimental SCI, mainly in astrocytes and microglia, as well as in the plasma of SCI patients. Functionally, MIF and CD74 were shown to regulate astrocyte viability, proliferation and cholesterol metabolism, microglia migration, and neuronal viability. Moreover, inhibition of the MIF/CD74 axis improved the functional recovery of SCI animals. We provide a detailed overview of studies analyzing the role of MIF and CD74 in traumatic SCI. We describe results from animal studies, using rat and mouse models for SCI, and human studies. Furthermore, we propose a new path for investigation, focused on B cells, that might lead to a better understanding of how MIF and CD74 contribute to the secondary injury cascade following traumatic SCI., (© 2024 Wiley‐VCH GmbH.)

Purpose: Cardiovascular health disparities are present in African Americans, but it remains unknown whether this phenomenon affect Somali Americans. Study of Somali Americans is warranted due to distinct genetic and cultural differences from African Americans of western African ancestry. Orthostatic hemodynamic responses have implications for cardiovascular risk, especially among African American females. We sought to examine race and sex differences in systolic (SAP) and diastolic (DAP) arterial pressure and heart rate (HR) responsiveness to standing. We hypothesized that SAP, DAP, and HR change from supine to standing position would be higher in Somali Americans., Methods: We studied blood pressure and HR responsiveness in 139 (70 Somali; age: 29±10 years, 69 White; age: 31±9 years) participants. Supine SAP, DAP, and HR were measured after at least five minutes of supine rest, and again after one minute of standing. SAP, DAP, and HR change was compared between groups., Results: ΔSAP and ΔDAP were similar between groups (race × sex: p>0.05). However, HR responsiveness to orthostasis varied between race and sex comparisons (race×sex: p=0.011). Somali females exhibited an augmented HR response to orthostasis compared to White females (Δ19±13 vs. 11±9 beats/min, p=0.005) and Somali males (Δ19±13 vs. 12±9 beats/min, p=0.020)., Conclusion: ΔHR to standing is augmented in young female Somali Americans. These findings highlight an early potential impairment in hemodynamic regulation that may heighten future cardiovascular risk. Further work is warranted to identify the potential autonomic nervous system underpinnings that may contribute to potentiated orthostatic responses and cardiovascular risk in Somali American females., Clinical Trial Registration: www.clinicaltrials.gov; unique identifier, NCT04124848; NCT05411029; NCT03308578., Competing Interests: Declarations VKS has consulted for Lilly, Zoll, Jazz Pharma, Axsome, and Know Labs and is on the Sleep Number Scientific Advisory Board. All other authors have no relevant conflicts to disclose.

In autoimmunity, FOXP3+ Tregs skew toward a proinflammatory, nonsuppressive phenotype and are, therefore, unable to control the exaggerated autoimmune response. This largely affects the success of autologous Treg therapy, which is currently under investigation for autoimmune diseases, including multiple sclerosis (MS). There is a need to ensure in vivo Treg stability before successful application of Treg therapy. Using genetic fate-mapping mice, we demonstrate that inflammatory, cytokine-expressing exFOXP3 T cells accumulate in the CNS during experimental autoimmune encephalomyelitis. In a human in vitro model, we discovered that interaction with inflamed blood-brain barrier endothelial cells (BBB-ECs) induces loss of function by Tregs. Transcriptome and cytokine analysis revealed that in vitro migrated Tregs have disrupted regenerative potential and a proinflammatory Th1/17 signature, and they upregulate the mTORC1 signaling pathway. In vitro treatment of migrated human Tregs with the clinically approved mTORC1 inhibitor rapamycin restored suppression. Finally, flow cytometric analysis indicated an enrichment of inflammatory, less-suppressive CD49d+ Tregs in the cerebrospinal fluid of people with MS. In summary, interaction with BBB-ECs is sufficient to affect Treg function, and transmigration triggers an additive proinflammatory phenotype switch. These insights help improve the efficacy of autologous Treg therapy of MS.