A Search for New Biological Pathways in Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy by Proteomic Research

Background/Objectives: Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is a hereditary small vessel disease leading to significant morbidity and mortality. Despite advances in genetic diagnosis, the underlying pathophysiology remains incompletely understood. Proteomic studies offer insights into disease mechanisms by identifying altered protein expression patterns. Here, we conducted a proteomic analysis to elucidate molecular pathways associated with CADASIL. Methods: We enrolled genetically diagnosed CADASIL patients and healthy, genetically related controls. Plasma samples were subjected to proteomic analysis using the Olink platform, measuring 552 proteins across six panels. The data were analyzed from several approaches by using three different statistical methods: Exploratory Principal Component Analysis (PCA) and Partial Least Squares-Discriminant Analysis (PLS-DA), differential expression with moderated t-test, and gene set enrichment analysis (GSEA). In addition, bioinformatics analysis, including volcano plot, heatmap, and Variable Importance on Projection (VIP) scores from the PLS-DA model were drawn. Results: Significant differences in protein expression were observed between CADASIL patients and controls. RSPO1 and FGF-19 exhibited elevated levels (p < 0.05), while PPY showed downregulation (p < 0.05) in CADASIL patients, suggesting their involvement in disease pathogenesis. Furthermore, MIC-A/B expression varied significantly between patients with mutations in exon 4 versus exon 11 of the NOTCH3 gene (p < 0.05), highlighting potential immunological mechanisms underlying CADASIL. We identified altered pathways using GSEA, applied after ranking the study data. Conclusions: Our study provides novel insights into the proteomic profile of CADASIL, identifying dysregulated proteins associated with vascular pathology, metabolic dysregulation, and immune activation. These findings contribute to a deeper understanding of CADASIL pathophysiology and may inform the development of targeted therapeutic strategies. Further research is warranted to validate these biomarkers and elucidate their functional roles in disease progression.

IL-6 from cerebrospinal fluid causes widespread pain via STAT3-mediated astrocytosis in chronic constriction injury of the infraorbital nerve

BACKGROUND

The spinal inflammatory signal often spreads to distant segments, accompanied by widespread pain symptom under neuropathological conditions. Multiple cytokines are released into the cerebrospinal fluid (CSF), potentially inducing the activation of an inflammatory cascade at remote segments through CSF flow. However, the detailed alteration of CSF in neuropathic pain and its specific role in widespread pain remain obscure.

METHODS

A chronic constriction injury of the infraorbital nerve (CCI-ION) model was constructed, and pain-related behavior was observed on the 7th, 14th, 21st, and 28th days post surgery, in both vibrissa pads and hind paws. CSF from CCI-ION rats was transplanted to naïve rats through intracisternal injection, and thermal and mechanical allodynia were measured in hind paws. The alteration of inflammatory cytokines in CCI-ION's CSF was detected using an antibody array and bioinformatic analysis. Pharmacological intervention targeting the changed cytokine in the CSF and downstream signaling was performed to evaluate its role in widespread pain.

RESULTS

CCI-ION induced local pain in vibrissa pads together with widespread pain in hind paws. CCI-ION's CSF transplantation, compared with sham CSF, contributed to vibrissa pad pain and hind paw pain in recipient rats. Among the measured cytokines, interleukin-6 (IL-6) and leptin were increased in CCI-ION's CSF, while interleukin-13 (IL-13) was significantly reduced. Furthermore, the concentration of CSF IL-6 was correlated with nerve injury extent, which gated the occurrence of widespread pain. Both astrocytes and microglia were increased in remote segments of the CCI-ION model, while the inhibition of astrocytes in remote segments, but not microglia, significantly alleviated widespread pain. Mechanically, astroglial signal transducer and activator of transcription 3 (STAT3) in remote segments were activated by CSF IL-6, the inhibition of which significantly mitigated widespread pain in CCI-ION.

CONCLUSION

IL-6 was induced in the CSF of the CCI-ION model, triggering widespread pain via activating astrocyte STAT3 signal in remote segments. Therapies targeting IL-6/STAT3 signaling might serve as a promising strategy for the widespread pain symptom under neuropathological conditions.

Brain Maturation as a Fundamental Factor in Immune-Neurovascular Interactions in Stroke

Injuries in the developing brain cause significant long-term neurological deficits. Emerging clinical and preclinical data have demonstrated that the pathophysiology of neonatal and childhood stroke share similar mechanisms that regulate brain damage, but also have distinct molecular signatures and cellular pathways. The focus of this review is on two different diseases-neonatal and childhood stroke-with emphasis on similarities and distinctions identified thus far in rodent models of these diseases. This includes the susceptibility of distinct cell types to brain injury with particular emphasis on the role of resident and peripheral immune populations in modulating stroke outcome. Furthermore, we discuss some of the most recent and relevant findings in relation to the immune-neurovascular crosstalk and how the influence of inflammatory mediators is dependent on specific brain maturation stages. Finally, we comment on the current state of treatments geared toward inducing neuroprotection and promoting brain repair after injury and highlight that future prophylactic and therapeutic strategies for stroke should be age-specific and consider gender differences in order to achieve optimal translational success.

Cerebral Arteriopathies of Childhood - Current Approaches

Up to more than half of previously healthy children presenting with their first arterial ischemic stroke have a cerebral arteriopathy. Cerebral arteriopathies during childhood can be congenital, reflecting abnormal vessel development, or acquired when caused by disruption of vascular homeostasis. Distinguishing different types of cerebral arteriopathies in children can be challenging but of great clinical value as they may dictate different disease and treatment courses, and clinical and radiologic outcomes. Furthermore, children with stroke due to a specific arteriopathy exhibit distinctive features when compared to those with stroke due to other causes or a different type of arteriopathy. These features become crucial in the management of pediatric stroke by choosing appropriate diagnostic and treatment strategies. The objective of this article is to provide the reader with a comprehensive up-to-date review of the classification, symptoms, diagnosis, treatment, and outcome of cerebral arteriopathies in children.

Laser Needle Knife's Effects on Rabbits Cervical Spondylopathy of Vertebral Artery, Fibrinogen, and Blood Viscosity

Objective

To determine the effect of laser needle-knife on vertebroarterial morphology, fibrinogen and blood viscosity in a rabbit model of cervical spondylotic arteriopathy (CSA) and the mechanism of action involved.

Methods

A number of 40 healthy common grade rabbits were divided into four groups: normal control, model, acupuncture, and laser needle knife group. The normal control group does not establish a CSA rabbit model, and the other groups all establish a CSA rabbit model, but they are treated in different ways. CSA model rabbits were treated with acupuncture and moxibustion at “fengchi” and “cervical Jiaji” points, rabbits in the laser needle knife group were treated with “Jiaji” points, and the acupuncture points were punctured with the laser needle knife. The location of the acupuncture points is determined according to the acupoint map of the experimental map. The right vertebroarterial morphology before and after the treatment was analyzed by scanning electron microscope, and FIB concentration and blood viscosity were determined using the coagulation method.

Results

After the treatment, the capillary and micropore hyperplasia in the laser needle knife group were more evident than that in the model group. Acupuncture and laser needle knife therapy can reduce whole blood viscosity (1/s, 5/s), and that the distinction between the two treatments is not statistically evident.

Conclusion

Acupuncture and laser needle knife can regulate the coagulation and fibrinolysis system in CSA, stimulate capillary and micropore hyperplasia, reduce blood viscosity, and improve blood circulation, which may be one of the therapeutic mechanisms behind the laser needle knife treatment of CSA.

Cerebrospinal fluid free light chain quantitation is a specific biomarker for inflammatory neurological disorders in a paediatric patient cohort

The analysis of cerebrospinal fluid (CSF) is routinely used in the diagnostic work-up of a range of inflammatory, infective, and congenital neurological conditions. Many diagnostic tests used in this analysis have poor sensitivity; as such, we investigated the utility of CSF free light chain (FLC) analysis as an adjunct to currently used assays in a paediatric population with neurological disorders. Kappa (κ) and lambda (λ) FLC levels were quantitated in blinded CSF samples by two nephelometric platforms. Results were correlated to clinical diagnoses and classified according to inflammatory/infective or non-inflammatory pathogenesis. FLC results were also compared to currently used CSF diagnostic tests including oligoclonal bands (OCB), CSF IgG and albumin levels, and differential cell count. Of 70 samples analysed, 29 (41%) had an inflammatory or infective diagnosis and 41 (59%) presented with a range of non-inflammatory aetiologies. Thirteen patients had elevated κFLC or λFLC as detected on the IMMAGE 800, defined as greater than the detection limit of the assay (0.600 mg/L for CSF κFLC, and 0.490 mg/L for CSF λFLC), and of these 12 (92%) had an inflammatory disease (sensitivity 41.4%, specificity 97.6%). On the BN II using optimal cut-offs of 0.27 mg/L and 0.12 mg/L for CSF κFLC and λFLC respectively, 24 (34%) patients had elevated results, of which 21 (88%) had an inflammatory disease (sensitivity 72.4%, specificity 92.7%). Analysis of FLC correlated better with diagnostic classification of the diseases than OCB, cell counts and CSF IgG levels. The results of this study support the use of CSF FLC analysis in the diagnosis of paediatric neuroinflammatory conditions.

Cerebrospinal fluid in COVID-19 neurological complications: no cytokine storm or neuroinflammation

BACKGROUND

Neurological complications occur in COVID-19. We aimed to examine cerebrospinal fluid (CSF) of COVID-19 subjects with neurological complications and determine presence of neuroinflammatory changes implicated in pathogenesis.

METHODS

Cross-sectional study of CSF neuroinflammatory profiles from 18 COVID-19 subjects with neurological complications categorized by diagnosis (stroke, encephalopathy, headache) and illness severity (critical, severe, moderate, mild). COVID-19 CSF was compared with CSF from healthy, infectious and neuroinflammatory disorders and stroke controls (n=82). Cytokines (IL-6, TNFα, IFNγ, IL-10, IL-12p70, IL-17A), inflammation and coagulation markers (high-sensitivity-C Reactive Protein [hsCRP], ferritin, fibrinogen, D-dimer, Factor VIII) and neurofilament light chain (NF-L), were quantified. SARS-CoV2 RNA and SARS-CoV2 IgG and IgA antibodies in CSF were tested with RT-PCR and ELISA.

RESULTS

CSF from COVID-19 subjects showed a paucity of neuroinflammatory changes, absence of pleocytosis or specific increases in pro-inflammatory markers or cytokines (IL-6, ferritin, or D-dimer). Anti-SARS-CoV2 antibodies in CSF of COVID-19 subjects (77%) were observed despite no evidence of SARS-CoV2 viral RNA. A similar increase of pro-inflammatory cytokines (IL-6, TNFα, IL-12p70) and IL-10 in CSF of COVID-19 and non-COVID-19 stroke subjects was observed compared to controls. CSF-NF-L was elevated in subjects with stroke and critical COVID-19. CSF-hsCRP was present almost exclusively in COVID-19 cases.

CONCLUSION

The paucity of neuroinflammatory changes in CSF of COVID-19 subjects and lack of SARS-CoV2 RNA do not support the presumed neurovirulence of SARS-CoV2 or neuroinflammation in pathogenesis of neurological complications in COVID-19. Elevated CSF-NF-L indicates neuroaxonal injury in COVID-19 cases. The role of CSF SARS-CoV2 IgG antibodies is still undetermined.

FUNDING

This work was supported by NIH R01-NS110122 and The Bart McLean Fund for Neuroimmunology Research.

MRI Vessel Wall Enhancement and Other Imaging Biomarkers in Pediatric Focal Cerebral Arteriopathy-Inflammatory Subtype

Background and Purpose—

Focal cerebral arteriopathy-inflammatory type (FCA-i) is a common cause of pediatric arterial ischemic stroke characterized angiographically by unifocal and unilateral stenosis/irregularity of the large anterior circulation arteries with a presumed inflammatory cause. Arterial vessel wall enhancement (VWE) on vessel wall magnetic resonance imaging is a potential biomarker of inflammation that may improve diagnosis, guide treatment, and predict outcomes in patients with FCA-i. We hypothesized that patients with FCA-i with more severe or extensive VWE would have worse arteriopathy, larger infarcts, worse clinical outcome, and increased risk for infarct progression/recurrence.

Methods—

Pediatric patients with arterial ischemic stroke, classified as FCA-i, and who underwent vessel wall imaging were retrospectively identified at our institution. Clinical data were reviewed and the Pediatric Stroke Outcome Measure at 1 year was determined as the primary clinical end point. Neuroimaging studies were assessed for infarct size, arteriopathy severity (Focal Cerebral Arteriopathy Severity Score), and VWE.

Results—

Nine cases of FCA-i with vessel wall imaging were evaluated, and there was a strong correlation between clinical outcome at 1-year with initial infarct volume (Spearman correlation coefficient rho=0.84; P <0.01) and arteriopathy severity (Focal Cerebral Arteriopathy Severity Score; rho=0.85; P <0.01). Patients with infarct progression/recurrence had worse Focal Cerebral Arteriopathy Severity Score at presentation compared with those without progression/recurrence (median [IQR]; 9.0 [8.0–11.8] and 5.0 [4.0–7.0], respectively; P <0.05). On the contrary, measures of VWE were not correlated with arteriopathy severity, infarct size, clinical outcome, or risk of infarct progression/recurrence. Moreover, not all patients with FCA-i demonstrated VWE.

Conclusions—

VWE may not be a reliable biomarker for the diagnosis or assessment of FCA-i, and future work is needed to assess the utility of vessel wall imaging in pediatric arterial ischemic stroke and FCA-i.