Novel multiparametric bulk and single EV pipeline for adipose cell-specific biomarker discovery in paired human biospecimens

Obesity is a global health crisis that contributes to morbidity and mortality worldwide. Obesity's comorbid association with a variety of diseases, from metabolic syndrome to neurodegenerative disease, underscores the critical need to better understand the pathobiology of obesity. Adipose tissue, once seen as an inert storage depot, is now recognized as an active endocrine organ, regulating metabolic and systemic homeostasis. Recent studies spotlight the theranostic utility of extracellular vesicles (EVs) as novel biomarkers and drivers of disease, including obesity-related complications. Adipose-derived EVs (ADEVs) have garnered increased interest for their roles in diverse diseases, however robust isolation and characterization protocols for human, cell-specific EV subsets are limited. Herein, we directly address this technical challenge by establishing a multiparametric analysis framework that leverages bulk and single EV characterization, mRNA phenotyping and proteomics of human ADEVs directly from paired visceral adipose tissue, cultured mature adipocyte conditioned media, and plasma from obese subjects undergoing bariatric surgery. Importantly, rigorous EV phenotyping at the tissue and cell-specific level identified top 'adipose liquid biopsy' candidates that were validated in circulating plasma EVs from the same patient. In summary, our study paves the way toward a tissue and cell-specific, multiparametric framework for studying tissue and circulating adipose EVs in obesity-driven disease.

Recommendations for reproducibility of cerebrospinal fluid extracellular vesicle studies

Cerebrospinal fluid (CSF) is a clear, transparent fluid derived from blood plasma that protects the brain and spinal cord against mechanical shock, provides buoyancy, clears metabolic waste and transports extracellular components to remote sites in the brain. Given its contact with the brain and the spinal cord, CSF is the most informative biofluid for studies of the central nervous system (CNS). In addition to other components, CSF contains extracellular vesicles (EVs) that carry bioactive cargoes (e.g., lipids, nucleic acids, proteins), and that can have biological functions within and beyond the CNS. Thus, CSF EVs likely serve as both mediators of and contributors to communication in the CNS. Accordingly, their potential as biomarkers for CNS diseases has stimulated much excitement for and attention to CSF EV research. However, studies on CSF EVs present unique challenges relative to EV studies in other biofluids, including the invasive nature of CSF collection, limited CSF volumes and the low numbers of EVs in CSF as compared to plasma. Here, the objectives of the International Society for Extracellular Vesicles CSF Task Force are to promote the reproducibility of CSF EV studies by providing current reporting and best practices, and recommendations and reporting guidelines, for CSF EV studies. To accomplish this, we created and distributed a world-wide survey to ISEV members to assess methods considered 'best practices' for CSF EVs, then performed a detailed literature review for CSF EV publications that was used to curate methods and resources. Based on responses to the survey and curated information from publications, the CSF Task Force herein provides recommendations and reporting guidelines to promote the reproducibility of CSF EV studies in seven domains: (i) CSF Collection, Processing, and Storage; (ii) CSF EV Separation/Concentration; (iii) CSF EV Size and Number Measurements; (iv) CSF EV Protein Studies; (v) CSF EV RNA Studies; (vi) CSF EV Omics Studies and (vii) CSF EV Functional Studies.

Engineering a tunable micropattern-array assay to sort single extracellular vesicles and particles to detect RNA and protein in situ

The molecular heterogeneity of extracellular vesicles (EVs) and the co-isolation of physically similar particles, such as lipoproteins (LPs), confounds and limits the sensitivity of EV bulk biomarker characterization. Herein, we present a single-EV and particle (siEVP) protein and RNA assay (siEVP PRA) to simultaneously detect mRNAs, miRNAs, and proteins in subpopulations of EVs and LPs. The siEVP PRA immobilizes and sorts particles via positive immunoselection onto micropatterns and focuses biomolecular signals in situ. By detecting EVPs at a single-particle resolution, the siEVP PRA outperformed the sensitivities of bulk-analysis benchmark assays for RNA and protein. To assess the specificity of RNA detection in complex biofluids, EVs from various glioma cell lines were processed with small RNA sequencing, whereby two mRNAs and two miRNAs associated with glioblastoma multiforme (GBM) were chosen for cross-validation. Despite the presence of single-EV-LP co-isolates in serum, the siEVP PRA detected GBM-associated vesicular RNA profiles in GBM patient siEVPs. The siEVP PRA effectively examines intravesicular, intervesicular, and interparticle heterogeneity with diagnostic promise.

Emerging role of extracellular vesicles in multiple sclerosis: From cellular surrogates to pathogenic mediators and beyond

Multiple Sclerosis (MS) is a chronic, inflammatory demyelinating disease of the central nervous system (CNS) driven by a complex interplay of genetic and environmental factors. While the therapeutic arsenal has expanded significantly for management of relapsing forms of MS, treatment of individuals with progressive MS is suboptimal. This treatment inequality is in part due to an incomplete understanding of pathomechanisms at different stages of the disease-underscoring the critical need for new biomarkers. Extracellular vesicles (EVs) and their bioactive cargo have emerged as endogenous nanoparticles with great theranostic potential-as diagnostic and prognostic biomarkers and ultimately as therapeutic candidates for precision nanotherapeutics. The goals of this review are to: 1) summarize the current data investigating the role of EVs and their bioactive cargo in MS pathogenesis, 2) provide a high level overview of advances and challenges in EV isolation and characterization for translational studies, and 3) conclude with future perspectives on this evolving field.

Do You See What I See? A Case of Alice in Wonderland Syndrome With EEG Correlate

Alice in Wonderland syndrome is a disorienting perceptual disorder characterized by discrete episodes of bizarre visual illusions and spatial distortions which has been associated with numerous neurologic and psychiatric conditions. Little is known regarding the electrophysiologic correlates of the visual symptoms described in this syndrome. The authors report the unique case of an 8-year-old boy presenting with visual distortions consistent with Alice in Wonderland syndrome, and an electroencephalogram demonstrating bilateral temporo-occipital slowing which correlated with symptoms of micropsia, teleopsia, and dysmorphopsia. Identification of this clinical syndrome and its electroclinical features are important for establishing a proper diagnosis and subsequent reassurance or appropriate treatment directed toward the underlying etiology.

Neuromyelitis optica IgG stimulates an immunological response in rat astrocyte cultures

Neuromyelitis optica (NMO) is a primary astrocyte disease associated with central nervous system inflammation, demyelination, and tissue injury. Brain lesions are frequently observed in regions enriched in expression of the aquaporin-4 (AQP4) water channel, an antigenic target of the NMO IgG serologic marker. Based on observations of disease reversibility and careful characterization of NMO lesion development, we propose that the NMO IgG may induce a dynamic immunological response in astrocytes. Using primary rat astrocyte-enriched cultures and treatment with NMO patient-derived serum or purified IgG, we observed a robust pattern of gene expression changes consistent with the induction of a reactive and inflammatory phenotype in astrocytes. The reactive astrocyte factor lipocalin-2 and a broad spectrum of chemokines, cytokines, and stress response factors were induced by either NMO patient serum or purified IgG. Treatment with IgG from healthy controls had no effect. The effect is disease-specific, as serum from patients with relapsing-remitting multiple sclerosis, Sjögren's, or systemic lupus erythematosus did not induce a response in the cultures. We hypothesize that binding of the NMO IgG to AQP4 induces a cellular response that results in transcriptional and translational events within the astrocyte that are consistent with a reactive and inflammatory phenotype. Strategies aimed at reducing the inflammatory response of astrocytes may short circuit an amplification loop associated with NMO lesion development.

Beneficial plasma exchange response in central nervous system inflammatory demyelination

BACKGROUND

Plasma exchange (PLEX) is a beneficial rescue therapy for acute, steroid-refractory central nervous system inflammatory demyelinating disease (CNS-IDD). Despite the approximately 45% PLEX response rate reported among patients with CNS-IDD, determinants of interindividual differences in PLEX response are not well characterized.

OBJECTIVE

To perform an exploratory analysis of clinical, radiographic, and serological features associated with beneficial PLEX response.

DESIGN

Historical cohort study.

SETTING

Neurology practice, Mayo Clinic College of Medicine, Rochester, Minnesota. Patients All Mayo Clinic patients treated with PLEX between January 5, 1999, and November 12, 2007, for a steroid-refractory CNS-IDD attack.

MAIN OUTCOME MEASURE

The PLEX response in attack-related, targeted neurological deficit(s) assessed within the 6-month period following PLEX.

RESULTS

We identified 153 patients treated with PLEX for a steroid-refractory CNS-IDD, of whom 90 (59%) exhibited moderate to marked functional neurological improvement within 6 months following treatment. Pre-PLEX clinical features associated with a beneficial PLEX response were shorter disease duration (P = .02) and preserved deep tendon reflexes (P = .001); post-PLEX variables included a diagnosis of relapsing-remitting multiple sclerosis (P = .008) and a lower Expanded Disability Status Scale score (P < .001) at last follow-up. Plasma exchange was less effective for patients with multiple sclerosis who subsequently developed a progressive disease course (P = .046). Radiographic features associated with a beneficial PLEX response were presence of ring-enhancing lesions (odds ratio = 4.00; P = .03) and/or mass effect (odds ratio = 3.00; P = .02). No association was found between neuromyelitis optica-IgG serostatus and PLEX response.

CONCLUSIONS

We have identified clinical and radiographic features that may aid in identifying patients with fulminant, steroid-refractory CNS-IDD attacks who are more likely to respond to PLEX.

Neuromyelitis optica IgG serostatus in fulminant central nervous system inflammatory demyelinating disease

BACKGROUND

The aquaporin-4-specific serum autoantibody neuromyelitis optica (NMO) IgG is a validated biomarker distinguishing NMO spectrum disorders from multiple sclerosis (MS). Because fulminant attacks are more common in NMO spectrum disorders than in MS, some investigators suggest that NMO IgG may be a marker of destructive demyelination rather than a disease-specific biomarker. To our knowledge, this study is the first to compare NMO IgG serostatus among patients with fulminant central nervous system inflammatory demyelinating disease (CNS IDD).

OBJECTIVE

To determine whether NMO IgG distinguishes patients with NMO spectrum disorders from those with other fulminant corticosteroid-refractory CNS IDD.

DESIGN

Descriptive historical cohort.

SETTING

Neuroimmunology laboratory and neurology practice, Mayo Clinic College of Medicine, Rochester, Minnesota. Patients Serum samples from 74 patients who underwent plasmapheresis between February 24, 1993, and November 22, 2007, for a corticosteroid-refractory CNS IDD were tested for NMO IgG by indirect immunofluorescence assay.

MAIN OUTCOME MEASURES

Two blinded observers scored serum samples tested at 1:120 dilution. Clinical data were obtained by medical record review.

RESULTS

Preplasmapheresis serum samples were available from 74 patients (ratio of women to men, 2:5); the mean interval between blood draw and plasmapheresis was 13 days. At the time of plasmapheresis, the mean age of patients was 46 years (age range, 7-80 years); the mean Expanded Disability Status Scale score was 7.0 (score range, 3.5-9.5 [10.0 is death]). Diagnoses included MS (18 patients with definite and 11 patients with probable), longitudinally extensive transverse myelitis involving at least 3 vertebral segments (20 patients), NMO (14 patients), transverse myelitis involving fewer than 3 vertebral segments (8 patients), optic neuritis (2 patients), and acute disseminated encephalomyelitis (1 patient). Neuromyelitis optica IgG was detected in 20 patients (27%) (10 with longitudinally extensive transverse myelitis, 9 with NMO, and 1 with recurrent optic neuritis) and was not detected in any patient with MS, short transverse myelitis, monophasic optic neuritis, or acute disseminated encephalomyelitis.

CONCLUSION

Neuromyelitis optica IgG is a specific biomarker for NMO spectrum disorders and is not simply a marker of destructive CNS IDD.

Posterior reversible encephalopathy syndrome in neuromyelitis optica spectrum disorders

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) is characterized by vasogenic subcortical edema without infarction. It has been associated with hypertensive crises and with immunosuppressive medications but not with neuromyelitis optica (NMO).

METHODS

We reviewed the clinical and neuroimaging features of five NMO-immunoglobulin G (IgG) seropositive white women who experienced an episode of PRES and had a coexisting NMO spectrum disorder (NMOSD). We also tested for the aquaporin-4 (AQP4) water channel autoantibody (NMO-IgG) in 14 patients from an independently ascertained cohort of individuals with PRES.

RESULTS

All five patients developed abrupt confusion and depressed consciousness consistent with PRES. The encephalopathy resolved completely within 7 days. Comorbid conditions or interventions recognized to be associated with PRES included orthostatic hypotension with supine hypertension, plasma exchange, IV immunoglobulin treatment, and high-dose IV methylprednisolone. Brain MRI studies revealed bilateral T2-weighted (T2W) hyperintense signal abnormalities, primarily in frontal, parieto-occipital, and cerebellar regions. Three patients had highly symmetric lesions and three had gadolinium-enhancing lesions. Follow-up neuroimaging revealed partial or complete disappearance of T2W hyperintensity or gadolinium-enhancing lesions in all five patients. Patients with PRES without NMOSD were uniformly NMO-IgG seronegative.

CONCLUSIONS

Brain lesions in some patients with neuromyelitis optica spectrum disorder (NMOSD) may be accompanied by vasogenic edema and manifest as posterior reversible encephalopathy syndrome (PRES). Water flux impairment due to aquaporin-4 autoimmunity may predispose to PRES in patients with NMOSD who experience blood pressure fluctuations or who are treated with therapies that can cause rapid fluid shifts.

Mental retardation research methods in Latino communities

The importance of understanding specific methods and strategies for conducting mental retardation research in Latino communities is discussed. Research methods used in the recruitment and analysis of a sample of 72 Puerto Rican mothers of a son or daughter with mental retardation are described. The emphasis is on the importance of involving the community in many aspects of the study in order to (a) ensure that the community benefits, (b) strengthen the scientific integrity of the study, and (c) facilitate sample recruitment.

Mental retardation research methods in Latino communities

The importance of understanding specific methods and strategies for conducting mental retardation research in Latino communities is discussed. Research methods used in the recruitment and analysis of a sample of 72 Puerto Rican mothers of a son or daughter with mental retardation are described. The emphasis is on the importance of involving the community in many aspects of the study in order to (a) ensure that the community benefits, (b) strengthen the scientific integrity of the study, and (c) facilitate sample recruitment.

Puerto Rican families caring for an adult with mental retardation: role of familism

The role of familism (a cultural value including interdependence among nuclear and extended family members for support, loyalty, and solidarity) in caregiving was explored for Puerto Rican mothers with children with mental retardation living at home. Familism--defined here as direct caregiving provided by family members to the person with mental retardation, mothers' social support networks, and mothers' obligations to other family members--was hypothesized to account for variation in maternal well-being. Better maternal well-being was predicted by larger social support networks, greater satisfaction with social support, and more minor children living in the household. A troubling but not unexpected finding is that these mothers faced many socioeconomic challenges and were in poor health in addition to the challenges of parenting a child with mental retardation.