because brain endothelial cells exist at the neurovascular interface, they may serve as cellular reporters of brain dysfunction by releasing biomarkers into the circulation.
we used proteomic techniques to screen conditioned media from human brain endothelial cultures subjected to oxidative stress induced by nitric oxide over 24 hours. Plasma samples from human stroke patients were analyzed by enzyme-linked immunosorbent assay.
in healthy endothelial cells, interaction mapping demonstrated cross-talk involving secreted factors, membrane receptors, and matrix components. In oxidatively challenged endothelial cells, networks of interacting proteins failed to emerge. Instead, inflammatory markers increased, secreted factors oscillated over time, and endothelial injury repair was manifested as changes in factors related to matrix integrity. Elevated inflammatory markers included heat shock protein, chemokine ligand-1, serum amyloid-A1, annexin-A5, and thrombospondin-1. Neurotrophic factors (prosaposin, nucleobindin-1, and tachykinin precursors) peaked at 12 hours, then rapidly decreased by 24 hours. Basement membrane components (fibronectin, desomoglein, profiling-1) were decreased. Cytoskeletal markers (actin, vimentin, nidogen, and filamin B) increased over time. From this initial analysis, the high-ranking candidate thrombospondin-1 was further explored in human plasma. Acute ischemic stroke patients had significantly higher thrombospondin-1 levels within 8 hours of symptom onset compared to controls with similar clinical risk factors (659 ± 81 vs 1132 ± 98 ng/mL; P<0.05; n=20).
screening of simplified cell culture systems may aid the discovery of novel biomarkers in clinical neurovascular injury. Further collaborative efforts are warranted to discover and validate more candidates of interest.
"Intriguingly, CD200 has been proposed to play a role in the immune privileged status of the CNS when CD200-mediated immune suppression occurs via neuron-microglial as well as glial-glial interactions in inflammatory conditions . THBS1 is linked to neuroinflammatory processes involving astrocyte and microglia through its role in processing and activating the TGF-β ligand  and is also implicated in responses to oxidative stress . Likewise, Notch1 is involved in microglial associated inflammation . "
[Show abstract][Hide abstract] ABSTRACT: Introduction
X-linked adrenoleukodystrophy (X-ALD) is a complex disorder with variable expressivity that affects the nervous, adrenocortical and male reproductive systems. Although ABCD1 mutations are known to provide the genetic basis for X-ALD, its pathogenesis is not fully elucidated. While elevated very long chain fatty acid (VLCFA) levels in blood and reduced VLCFA catabolic activity in cultured fibroblasts are biomarkers used to identify ABCD1 mutation carriers, the roles peroxisomal lipid metabolism play in disease etiology are unknown.
Primary skin fibroblasts from two male patients with the childhood cerebral form of the disease (CCALD) caused by ABCD1 frameshift or missense mutations and three healthy donors were transduced with retroviral vectors expressing the OCT4, SOX2, KLF4 and c-MYC factors. Candidate induced pluripotent stem cells (iPSCs) were subject to global gene expression, DNA methylation, DNA copy number variation, and genotyping analysis and tested for pluripotency through in vitro differentiation and teratoma formation. Saturated VLCFA (sVLCFA) and plasmalogen levels in primary fibroblasts and iPSCs from healthy donors as well as CCALD patients were determined through mass spectroscopy.
Skin fibroblasts from CCALD patients and healthy donors were reprogrammed into validated iPSCs. Unlike fibroblasts, CCALD patient iPSCs show differentially expressed genes (DEGs) relevant to both peroxisome abundance and neuroinflammation. Also, in contrast to fibroblasts, iPSCs from patients showed no significant difference in sVLCFA levels relative to those from controls. In all cell types, the plasmalogen levels tested did not correlate with ABCD1 mutation status.
Normal ABCD1 gene function is not required for reprogramming skin fibroblasts into iPSCs or maintaining pluripotency. Relative to DEGs found in fibroblasts, DEGs uncovered in comparisons of CCALD patient and control iPSCs are more consistent with major hypotheses regarding disease pathogenesis. These DEGs were independent of differences in sVLCFA levels, which did not vary according to ABCD1 mutation status. The highlighted genes provide new leads for pathogenic mechanisms that can be explored in animal models and human tissue specimens. We suggest that these iPSC resources will have applications that include assisting efforts to identify genetic and environmental modifiers and screening for therapeutic interventions tailored towards affected cell populations and patient genotypes.
[Show abstract][Hide abstract] ABSTRACT: Stroke-related translational research is multifaceted. Herein, we highlight genome-wide association studies and genetic studies of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, COL4A1 mutations, and cerebral cavernous malformations; advances in molecular biology and biomarkers; newer brain imaging research; and recovery from stroke emphasizing cell-based and other rehabilitative modalities. Arch Neurol. 2011;68(9):1110-1123. Published online May 9, 2011. doi:10.1001/archneurol.2011.99
Archives of neurology 05/2011; 68(9):1110-23. DOI:10.1001/archneurol.2011.99 · 7.42 Impact Factor
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