Intense Correlation Between Brain Infarction and Protein-Conjugated Acrolein

Abstract

Background and Purpose-We recently found that increases in plasma levels of protein-conjugated acrolein and polyamine oxidases, enzymes that produce acrolein, are good markers for stroke. The aim of this study was to determine whether the level of protein-conjugated acrolein is increased and levels of spermine and spermidine, the substrates of acrolein production, are decreased at the locus of infarction. Methods-A unilateral infarction was induced in mouse brain by photoinduction after injection of Rose Bengal. The volume of the infarction was analyzed using the public domain National Institutes of Health image program. The level of protein-conjugated acrolein at the locus of infarction and in plasma was measured by Western blotting and enzyme-linked immunosorbent assay, respectively. The levels of polyamines at the locus of infarction and in plasma were measured by high-performance liquid chromatography. Results-The level of protein-conjugated acrolein was greatly increased, and levels of spermine and spermidine were decreased at the locus of infarction at 24 hours after the induction of stroke. The size of infarction was significantly decreased by N-acetylcysteine, a scavenger of acrolein. It was also found that the increases in the protein-conjugated acrolein, polyamines, and polyamine oxidases in plasma were observed after the induction of stroke. Key Words: acrolein Ⅲ brain infarction Ⅲ neuroprotective agents Ⅲ polyamines Ⅲ risk factors B rain stroke is a serious pathology. However, there is a lack of good biomarkers for the early phase of stroke. We recently found that increased levels of protein-conjugated acrolein (PC-Acro) and the enzymes responsible for its production, polyamine oxidases (spermine oxidase and acetylpolyamine oxidase), are good biomarkers for human stroke. 1 We also found that measurement of PC-Acro together with interleukin-6 and C-reactive protein makes it possible to identify small infarctions, that is, silent brain infarction, with high sensitivity (89%) and specificity (91%). 2 This tool for early identification of stroke may help in the application of suitable therapy to delay or reduce aggravation of stroke. Conclusions-The results indicate that the induction of infarction is well correlated with the increase in protein-It is thought that cell damage is mainly caused by reactive oxygen species (ROS) 3 such as superoxide anion radical (O 2 Ϫ⅐ ), hydrogen peroxide (H 2 O 2 ), and hydroxyl radical (⅐OH). However, when we compared the toxicity of acrolein (CH 2 ϭCHCHO) and ROS, we found that acrolein was more toxic than H 2 O 2 4 and slightly more toxic than ⅐OH 5 in cell culture systems. Furthermore, acrolein is thought to be produced by lipid peroxidation, 6 but we found that it was more effectively produced from 2 polyamines (spermine and spermidine), 1 which are abundant and essential for cell growth in eukaryotic cells. 7 Acrolein is spontaneously formed from 3-aminopropanal (NH 2 [CH 2 ] 2 CHO) produced from spermine by spermine oxidase (SMO) and less effectively from 3-acetam...

Protective Effects of Brain Infarction by N -Acetylcysteine Derivatives

“…If it is possible to protect or delay the aggravation of brain infarction and dementia, it could greatly contribute to the maintenance of quality of life of the elderly. We have previously reported that a toxic compound, acrolein, becomes a good biomarker for brain infarction 11 and dementia. 23 Thus, we looked for compounds that decrease the level of acrolein during brain damage and do not have severe side effects.…”

“…acrolein scavengers, such as N-acetylcysteine (NAC) 11 and N-benzylhydroxylamine, 12 decreased the size of brain infarction using photochemically induced thrombosis (PIT) mice.…”

“…PIT model mice were prepared using 8-week-old male C57BL/6 mice (22-26 g) as described previously. 11 Animals were randomized to treatment groups ahead of time. Mice were anesthetized with 4% isoflurane and then maintained on 1.5% isoflurane using a smallanimal anesthesia system.…”

“…The level of PC-Acro was measured by Western blotting 15 as described previously, 11 using antibody against FDP-lysine [N ε -(3-formyl-3,4-dehydropiperidino-lysine)]. 18 mmol) and stirred for 1.5 hours at room temperature.…”

“…11 However, it may be difficult to deliver NAC to the brain because it is hydrophilic. Thus, 2 kinds of NAC derivatives (NAC ethyl ester [NACEt] and NAC benzyl ester [NACBn]) were synthesized ( Figure 1A), and the effects of these derivatives together with NAC on brain infarction were evaluated by simultaneous administration during brain ischemia or by preadministration before ischemia.…”