Purification of a factor from CSF in patient after SAH which induces the cytosolic free calcium elevation in vascular smooth muscle cells

Comparative proteomic analysis of ventricular and cisternal cerebrospinal fluid in haemorrhagic stroke patients

BACKGROUND

Analysis of cerebrospinal fluid (CSF) using mass spectrometry is a relatively novel analytical tool, and comparisons of ventricular and cisternal proteomes are yet to be performed. This may have implications for clinical medicine, particularly in demonstrating continuity of the ventricular system with preserved flow in the presence of ventricular blood. Other uses include the identification of novel biomarkers, including for diagnosis of subarachnoid haemorrhage and of aetiology. The primary objective was therefore to characterise and compare the proteomes of ventricular and CSF after haemorrhagic stroke.

METHODS

Paired CSF samples were prospectively collected from the optico-carotid cistern and the frontal horn of the lateral ventricle at the time of craniotomy and clipping in 8 patients with haemorrhagic stroke. Six patients had an aneurysmal subarachnoid haemorrhage (aSAH) from a ruptured saccular aneurysm, one patient had an aSAH after rupture of a mycotic aneurysm and one patient had a spontaneous intracerebral haemorrhage (IPH) with an adjacent unruptured saccular aneurysm. Samples were processed and proteins identified and quantified using data-dependent liquid chromatography tandem mass spectrometry (DDA LC-MSMS).

RESULTS

There was no systematic difference between the cisternal and ventricular proteomes. However, blinded principal component analysis (PCA) of the cisternal and ventricular samples separated patients according to pathophysiology. Additionally CSF D-Dimer levels were not detected in the IPH patient but were reliably measured in aSAH patients.

CONCLUSIONS

Ventricular CSF is representative of cisternal CSF after aSAH. CSF proteomic PCA analysis can distinguish between haemorrhage types. CSF D-dimer levels may represent a novel diagnostic marker for aSAH. Label free DDA LC-MSMS CSF analysis may inform possible biomarkers.

Brain iron metabolism and brain injury following subarachnoid hemorrhage: iCeFISH-pilot (CSF iron in SAH)

INTRODUCTION

Iron-mediated oxidative damage has been implicated in the genesis of cerebral vasospasm in animal models of SAH. We sought to explore the relationship between levels of non-protein bound iron in cerebrospinal fluid and the development of brain injury in patients with aneurysmal SAH.

METHODS

Patients admitted with aneurysmal subarachnoid hemorrhage to a Neurointensive care unit of an academic, tertiary medical center, with Hunt and Hess grades 2-4 requiring ventriculostomy insertion as part of their clinical management were included in this pilot study. Samples of cerebrospinal fluid (CSF) were obtained on days 1, 3, and 5. A fluorometric assay that relies on an oxidation sensitive probe was used to measure unbound iron, and levels of iron-handling proteins were measured by means of enzyme-linked immunosorbent assays. We prospectively collected and recorded demographic, clinical, and radiological data.

RESULTS

A total of 12 patients were included in this analysis. Median Hunt and Hess score on admission was 3.5 (IQR: 1) and median modified Fisher scale score was 4 (IQR: 1). Seven of 12 patients (58 %) developed delayed cerebral ischemia (DCI). Day 5 non-transferrin bound iron (NTBI) (7.88 ± 1 vs. 3.58 ± 0.8, p = 0.02) and mean NTBI (7.39 ± 0.4 vs. 3.34 + 0.4 p = 0.03) were significantly higher in patients who developed DCI. Mean redox-active iron, as well as day 3 levels of redox-active iron correlated with development of angiographic vasospasm in logistic regression analysis (p = 0.02); while mean redox-active iron and lower levels of ceruloplasmin on days 3, 5, and peak concentration were correlated with development of deep cerebral infarcts.

CONCLUSIONS

Our preliminary data indicate a causal relationship between unbound iron and brain injury following SAH and suggest a possible protective role for ceruloplasmin in this setting, particularly in the prevention of cerebral ischemia. Further studies are needed to validate these findings and to probe their clinical significance.

Vascular smooth muscle function: The physiology and pathology of vasoconstriction

Vascular smooth muscle is the contractile component of arteries and veins. The control of contraction and relaxation is dependent upon intracellular and extracellular signals. Abnormal contractions can cause and or contribute to pathology such as hypertension, ischemia and infarction. In this review, we address the vascular pathogenesis associated with hypertension and subarachnoid hemorrhage induced cerebral vasospasm. Hypertension is a multifactorial disease with many causes and a profound impact on the cardiovascular system, whereas subarachnoid hemorrhage induced cerebral vasospasm is a pathological vasoconstriction often causing infarction that is thought to be 'caused' by a factor or factors in the CSF following the hemorrhage. However, the mechanism by which the vessels are constricted is unknown. Although the causes for these two pathological vasoconstrictions remain to be determined, we conclude that the common denominator is that these contractile changes result in pathology with devastating consequences to human health.

Molecular keys to the problems of cerebral vasospasm

The mechanisms responsible for subarachnoid hemorrhage (SAH)-induced vasospasm are under intense investigation but remain incompletely understood. A consequence of SAH-induced vasospasm, cerebral infarction, produces a nonrecoverable ischemic tissue core surrounded by a potentially amenable penumbra. However, successful treatment has been inconsistent. In this review, we summarize the basic molecular biology of cerebrovascular regulation, describe recent developments in molecular biology to elucidate the mechanisms of SAH-induced vasospasm, and discuss the potential contribution of cerebral microcirculation regulation to the control of ischemia. Our understanding of the pathogenesis of SAH-induced vasospasm remains a major scientific challenge; however, molecular biological techniques are beginning to uncover the intracellular mechanisms involved in vascular regulation and its failure. Recent findings of microvascular regulatory mechanisms and their failure after SAH suggest a role in the development and size of the ischemia. Progress is being made in identifying the various components in the blood that cause SAH-induced vasospasm. Thus, our evolving understanding of the underlying molecular mechanism may provide the basis for improved treatment after SAH-induced vasospasm, especially at the level of the microcirculation.