Plasma Platelet-Activating Factor–Acetyl Hydrolase Activity and the Levels of Free Forms of Biomarker of Lipid Peroxidation in Cerebrospinal Fluid of Patients With Aneurysmal Subarachnoid Hemorrhage

Neurosurgery ◽  
2011 ◽  
Vol 70 (3) ◽  
pp. 602-609 ◽  
Author(s):  
Yutaka Hirashima ◽  
Masaru Doshi ◽  
Nakamasa Hayashi ◽  
Shunro Endo ◽  
Yoko Akazawa ◽  
...  

Abstract Background: Free radicals and lipid peroxidation are thought to be related to the vasospasm generation after subarachnoid hemorrhage (SAH). Plasma platelet-activating factor-acetyl hydrolase (PAF-AH) degrades phospholipids with an oxidatively modified fatty acyl chain. Objective: To compare plasma PAF-AH activity and free forms of biomarker of lipid peroxidation in cerebrospinal fluid (CSF) between patients with and without symptomatic vasospasm (SVS) after SAH. Methods: The identification of PAF-AH in CSF was performed by Western blotting. The genotype at position 279 of the plasma PAF-AH gene was determined. The activities of PAF-AH and the levels of free 8-iso-prostaglandin F2α (free isoPs), free hydroxyoctadecadienoic acid (free HODE), and free hydroxyeicosatetraenoic acid (free HETE) in CSF were measured. Results: The PAF-AH in CSF was confirmed to be only the plasma type. The genotype of the plasma PAF-AH was not different between patients with and without SVS. Free isoPs, free HODE, and free HETE showed higher values in patients without SVS in 0 to 4 days and 5 to 9 days after SAH. The PAF-AH activity also was higher in patients without SVS in 0 to 4 days and 5 to 9 days after SAH. The associations between PAF-AH activity and free isoPs, and between PAF-AH activity and free HODE were significant. Conclusion: Oxidized lipids of lipoproteins and blood cell membranes produced by reactive oxygen species in CSF when SAH occurs may be the main source of lipid peroxidation. Plasma PAF-AH can hydrolyze oxidized phospholipids, and may attenuate the spreading of lipid peroxidation and participate in defense mechanisms against vasospasm after SAH.

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Anika Männer ◽  
Dominique Thomas ◽  
Marlies Wagner ◽  
Jürgen Konczalla ◽  
Helmuth Steinmetz ◽  
...  

Abstract Background and purpose Sphingosin-1-phosphate (S1P) plays a crucial role as a signaling molecule in the immune system and the vasculature. Previous studies suggested a role as a vasoconstrictor of cerebral arteries via the S1P3-Receptor. Cerebral vasospasm (VS) following aneurysmal subarachnoid hemorrhage (SAH) is a major cause of disability and poor neurological outcome. Early detection of vasospasm could facilitate the prevention of cerebral ischemia in SAH patients. The aim of this prospective case-control study was to characterize the dynamics of S1P in the cerebrospinal fluid (CSF) of patients with SAH in relation to hemorrhage volume, the occurrence of VS, and neurological outcome. Methods S1P levels in CSF of 18 control subjects and 18 SAH patients with placement of an external ventricular drainage (EVD) were determined by high sensitivity mass spectrometry from day 1 through 14 after SAH onset. Hemorrhage volume, development of asymptomatic vasospasm (aVS) and symptomatic vasospasm (sVS), and neurological outcome were correlated to day 1 S1P levels. Results The intrathecal S1P levels of SAH patients were higher than those of the control subjects, and correlated with hemorrhage volume. There was no significant difference in S1P levels between patients with aVS and those with sVS. S1P levels significantly correlated with neurological outcome on a sliding modified Rankin scale. Conclusion S1P levels were highest directly after placement of the EVD and correlated strongly with hemorrhage volume, which may be caused by the intrathecal clot and subsequent lysis of red blood cells, an important source of S1P. We did not detect a second peak of S1P release over the course of the intensive care period.


2021 ◽  
Author(s):  
Kevin Akeret ◽  
Raphael M. Buzzi ◽  
Christian A. Schaer ◽  
Bart R. Thomson ◽  
Florence Vallelian ◽  
...  

AbstractSecondary brain injury after aneurysmal subarachnoid hemorrhage (SAH-SBI) is a significant contributor to poor outcomes in patients after rupture of an intracranial aneurysm. The lack of diagnostic biomarkers and novel drug targets represent an unmet need. Prior experimental evidence has suggested cell-free hemoglobin in the cerebrospinal fluid (CSF-Hb) as a pathophysiological driver of SAH-SBI. The aim of this study was to investigate the clinical and pathophysiological association between CSF-Hb and SAH-SBI. We prospectively enrolled 47 consecutive patients and collected daily CSF samples within 14 days after aneurysm rupture. There was very strong evidence for a positive association between CSF-Hb and SAH-SBI. The diagnostic accuracy of CSF-Hb for SAH-SBI markedly exceeded that of established methods (area under the curve: 0.89 [0.85-0.92]). Temporal LC-MS/MS CSF proteomics demonstrated that erythrolysis accompanied by an adaptive macrophage response are the two dominant biological processes occurring in the CSF space after aneurysm rupture. To further investigate the pathophysiology between CSF-Hb and SAH-SBI, we explored the vasoconstrictive and lipid peroxidation activities of Hb ex-vivo. These experiments revealed critical inflection points overlapping CSF-Hb concentration thresholds in patients with SAH-SBI. Selective Hb depletion and in-solution neutralization by the Hb-scavenger haptoglobin or the heme-scavenger hemopexin efficiently attenuated the vasoconstrictive and lipid peroxidation activities of CSF-Hb in patient CSF. Collectively, the clinical association between high CSF-Hb levels and SAH-SBI, the underlying pathophysiological rationale, and the favorable effects of haptoglobin and hemopexin in ex-vivo experiments position CSF-Hb as a highly attractive biomarker and potential drug target.


Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1925 ◽  
Author(s):  
Giulia Coliva ◽  
Mike Lange ◽  
Simone Colombo ◽  
Jean-Pierre Chervet ◽  
M. Rosario Domingues ◽  
...  

Free radical driven lipid peroxidation is a chain reaction which can lead to oxidative degradation of biological membranes. Propagation vs. termination rates of peroxidation in biological membranes are determined by a variety of factors including fatty acyl chain composition, presence of antioxidants, as well as biophysical properties of mono- or bilayers. Sphingomyelins (SMs), a class of sphingophospholipids, were previously described to inhibit lipid oxidation most probably via the formation of H-bond network within membranes. To address the “antioxidant” potential of SMs, we performed LC-MS/MS analysis of model SM/glycerophosphatidylcholine (PC) liposomes with different SM fraction after induction of radical driven lipid peroxidation. Increasing SM fraction led to a strong suppression of lipid peroxidation. Electrochemical oxidation of non-liposomal SMs eliminated the observed effect, indicating the importance of membrane structure for inhibition of peroxidation propagation. High resolution MS analysis of lipid peroxidation products (LPPs) observed in in vitro oxidized SM/PC liposomes allowed to identify and relatively quantify SM- and PC-derived LPPs. Moreover, mapping quantified LPPs to the known pathways of lipid peroxidation allowed to demonstrate significant decrease in mono-hydroxy(epoxy) LPPs relative to mono-keto derivatives in SM-rich liposomes. The results presented here illustrate an important property of SMs in biological membranes, acting as “biophysical antioxidant”. Furthermore, a ratio between mono-keto/mono-hydroxy(epoxy) oxidized species can be used as a marker of lipid peroxidation propagation in the presence of different antioxidants.


1984 ◽  
Vol 62 (11) ◽  
pp. 1134-1150 ◽  
Author(s):  
P. M. Macdonald ◽  
B. D. Sykes ◽  
R. N. McElhaney

The orientational order parameters of monofluoropalmitic acids biosynthetically incorporated into membranes of Acholeplasma laidlawii B in the presence of a large excess of a variety of structurally diverse fatty acids have been determined via 19F nuclear magnetic resonance (19F NMR) spectroscopy. It is demonstrated that these monofluoropalmitic acids are relatively nonperturbing membrane probes based upon physical (differential scanning calorimetry), biochemical (membrane lipid analysis), and biological (growth studies) criteria. 19F NMR is shown to convey the same qualitative and quantitative picture of membrane lipid order provided by 2H-NMR techniques and to be sensitive to the structural characteristics of the membrane fatty acyl chains, as well as to the lipid phase transition. Representatives of each naturally occurring class of fatty acyl chain structures, including straight-chain saturated, methyl-branched, monounsaturated, and alicyclic-ring-substituted fatty acids, were studied and the 19F-NMR order parameters were correlated with the lipid phase transitions (determined calorimetrically). The lipid phase transition was the prime determinant of overall orientational order regardless of fatty acid structure. Effects upon orientational order attributable to specific structural substituents were discernible, but were secondary to the effects of the lipid phase transition. In the gel state, relative overall order was directly proportional to the temperature of the particular lipid phase transition. Not only the overall order, but also the order profile across the membrane was sensitive to the presence of particular structural substituents. In particular, in the gel state specific fatty acyl structures demonstrated a characteristic disordering effect in the membrane order profile. These various observations can be merged to provide a unified picture of the manner in which fatty acyl chain chemistry modulates the physical state of membrane lipids.


Cancers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2475
Author(s):  
Megan Sheridan ◽  
Besim Ogretmen

Sphingolipids are bioactive lipids responsible for regulating diverse cellular functions such as proliferation, migration, senescence, and death. These lipids are characterized by a long-chain sphingosine backbone amide-linked to a fatty acyl chain with variable length. The length of the fatty acyl chain is determined by specific ceramide synthases, and this fatty acyl length also determines the sphingolipid’s specialized functions within the cell. One function in particular, the regulation of the selective autophagy of mitochondria, or mitophagy, is closely regulated by ceramide, a key regulatory sphingolipid. Mitophagy alterations have important implications for cancer cell proliferation, response to chemotherapeutics, and mitophagy-mediated cell death. This review will focus on the alterations of ceramide synthases in cancer and sphingolipid regulation of lethal mitophagy, concerning cancer therapy.


2000 ◽  
Vol 28 (4) ◽  
pp. 984-990 ◽  
Author(s):  
Adnan I. Qureshi ◽  
Gene Y. Sung ◽  
Alexander Y. Razumovsky ◽  
Karen Lane ◽  
Robert N. Straw ◽  
...  

Neurosurgery ◽  
1990 ◽  
Vol 27 (6) ◽  
pp. 921-928 ◽  
Author(s):  
Yoshihiro Yamamoto ◽  
David H. Bernanke ◽  
Robert R. Smith

Abstract The cause of chronic cerebral vasospasm after subarachnoid hemorrhage has been studied intensively, but it is still controversial whether the observable luminal narrowing should be attributed to the contraction of vascular smooth muscle cells or whether it results from some organic change in the wall. A proliferation of myointimal cells, accompanied by increased deposition of collagen, as well as myonecrosis, have been frequently observed several days after aneurysm rupture. Studies from our laboratory showed that these myointimal cells had characteristics identical to myofibroblasts. In this study, we quantitatively and morphologically examined the effect of cerebrospinal fluid on the ability of myofibroblasts to alter collagen matrices using an in vitro model. Myofibroblasts contract the collagen matrix by rearranging or compacting the framework of collagen fibers. Cerebrospinal fluid obtained from patients with recently ruptured aneurysms significantly accelerated lattice contraction, especially when the patient developed symptomatic vasospasm. This study suggests that myofibroblasts in the spastic artery can produce a contractile force that contributes to chronic vasospasm, tightening the proliferated collagen. Some unknown agent present in bloody cerebrospinal fluid accelerates the rearrangement of the collagen lattice by myofibroblasts, both of which have, until now, been considered non-contractile components.


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