Identification of biochemical pathways for the metabolism of oxidized low-density lipoprotein derived aldehyde-4-hydroxy trans-2-nonenal in vascular smooth muscle cells

Sanjay Srivastava, Daniel J. Conklin, Si Qi Liu, Nidhi Prakash, Paul J. Boor, Satish Srivastava, Aruni Bhatnagar

Research output: Contribution to journalArticle

66 Citations (Scopus)

Abstract

Oxidation of low-density lipoproteins (LDL) generates high concentrations of unsaturated aldehydes, such as 4-hydroxy trans-2-nonenal (HNE). These aldehydes are mitogenic to vascular smooth muscle cells and sustain a vascular inflammation. Nevertheless, the processes that mediate and regulate the vascular metabolism of these aldehydes have not been examined. In this communication, we report the identification of the major metabolic pathways and products of [3H]-HNE in rat aortic smooth muscle cells in culture. High-performance liquid chromatography separation of the radioactivity recovered from these cells revealed that a large (60-65%) proportion of the metabolism was linked to glutathione (GSH). Electrospray mass spectrometry showed that glutathionyl-1,4 dihydroxynonene (GS-DHN) was the major metabolite of HNE in these cells. The formation of GS-DHN appears to be due aldose reductase (AR)-catalyzed reduction of glutathionyl 4-hydroxynonanal (GS-HNE), since inhibitors of AR (tolrestat or sorbinil) prevented GS-DHN formation, and increased the fraction of the glutathione conjugate remaining as GS-HNE. Gas chromatography-chemical ionization mass spectroscopy of the metabolites identified a subsidiary route of HNE metabolism leading to the formation of 4-hydroxynonanoic acid (HNA). Oxidation to HNA accounted for 25-30% of HNE metabolism. The formation of HNA was inhibited by cyanamide, indicating that the acid is derived from an aldehyde dehydrogenase (ALDH)-catalyzed pathway. The overall rate of HNE metabolism was insensitive to inhibition of AR or ALDH, although inhibition of HNA formation by cyanamide led to a corresponding increase in the fraction of HNE metabolized by the GSH-linked pathway, indicating that ALDH-catalyzed oxidation competes with glutathione conjugation. These metabolic pathways may be the key regulators of the vascular effects of HNE and oxidized LDL.

Original languageEnglish (US)
Pages (from-to)339-350
Number of pages12
JournalAtherosclerosis
Volume158
Issue number2
DOIs
StatePublished - 2001

Fingerprint

Vascular Smooth Muscle
Aldehydes
Smooth Muscle Myocytes
Aldehyde Reductase
Aldehyde Dehydrogenase
Acids
Cyanamide
Glutathione
Blood Vessels
Metabolic Networks and Pathways
Mass Spectrometry
2-nonenal
oxidized low density lipoprotein
4-hydroxy-2-nonenal
LDL Lipoproteins
Gas Chromatography
Radioactivity
Cell Culture Techniques
High Pressure Liquid Chromatography
Inflammation

Keywords

  • 4-Hydroxy-trans-2-nonenal
  • Aldose reductase
  • Atherosclerosis
  • Glutathione conjugates
  • Lipid peroxidation
  • Vascular smooth muscle cells

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine

Cite this

Identification of biochemical pathways for the metabolism of oxidized low-density lipoprotein derived aldehyde-4-hydroxy trans-2-nonenal in vascular smooth muscle cells. / Srivastava, Sanjay; Conklin, Daniel J.; Liu, Si Qi; Prakash, Nidhi; Boor, Paul J.; Srivastava, Satish; Bhatnagar, Aruni.

In: Atherosclerosis, Vol. 158, No. 2, 2001, p. 339-350.

Research output: Contribution to journalArticle

Srivastava, Sanjay ; Conklin, Daniel J. ; Liu, Si Qi ; Prakash, Nidhi ; Boor, Paul J. ; Srivastava, Satish ; Bhatnagar, Aruni. / Identification of biochemical pathways for the metabolism of oxidized low-density lipoprotein derived aldehyde-4-hydroxy trans-2-nonenal in vascular smooth muscle cells. In: Atherosclerosis. 2001 ; Vol. 158, No. 2. pp. 339-350.
@article{1ae3b7df18504203b401f98376fc7eb0,
title = "Identification of biochemical pathways for the metabolism of oxidized low-density lipoprotein derived aldehyde-4-hydroxy trans-2-nonenal in vascular smooth muscle cells",
abstract = "Oxidation of low-density lipoproteins (LDL) generates high concentrations of unsaturated aldehydes, such as 4-hydroxy trans-2-nonenal (HNE). These aldehydes are mitogenic to vascular smooth muscle cells and sustain a vascular inflammation. Nevertheless, the processes that mediate and regulate the vascular metabolism of these aldehydes have not been examined. In this communication, we report the identification of the major metabolic pathways and products of [3H]-HNE in rat aortic smooth muscle cells in culture. High-performance liquid chromatography separation of the radioactivity recovered from these cells revealed that a large (60-65{\%}) proportion of the metabolism was linked to glutathione (GSH). Electrospray mass spectrometry showed that glutathionyl-1,4 dihydroxynonene (GS-DHN) was the major metabolite of HNE in these cells. The formation of GS-DHN appears to be due aldose reductase (AR)-catalyzed reduction of glutathionyl 4-hydroxynonanal (GS-HNE), since inhibitors of AR (tolrestat or sorbinil) prevented GS-DHN formation, and increased the fraction of the glutathione conjugate remaining as GS-HNE. Gas chromatography-chemical ionization mass spectroscopy of the metabolites identified a subsidiary route of HNE metabolism leading to the formation of 4-hydroxynonanoic acid (HNA). Oxidation to HNA accounted for 25-30{\%} of HNE metabolism. The formation of HNA was inhibited by cyanamide, indicating that the acid is derived from an aldehyde dehydrogenase (ALDH)-catalyzed pathway. The overall rate of HNE metabolism was insensitive to inhibition of AR or ALDH, although inhibition of HNA formation by cyanamide led to a corresponding increase in the fraction of HNE metabolized by the GSH-linked pathway, indicating that ALDH-catalyzed oxidation competes with glutathione conjugation. These metabolic pathways may be the key regulators of the vascular effects of HNE and oxidized LDL.",
keywords = "4-Hydroxy-trans-2-nonenal, Aldose reductase, Atherosclerosis, Glutathione conjugates, Lipid peroxidation, Vascular smooth muscle cells",
author = "Sanjay Srivastava and Conklin, {Daniel J.} and Liu, {Si Qi} and Nidhi Prakash and Boor, {Paul J.} and Satish Srivastava and Aruni Bhatnagar",
year = "2001",
doi = "10.1016/S0021-9150(01)00454-3",
language = "English (US)",
volume = "158",
pages = "339--350",
journal = "Atherosclerosis",
issn = "0021-9150",
publisher = "Elsevier Ireland Ltd",
number = "2",

}

TY - JOUR

T1 - Identification of biochemical pathways for the metabolism of oxidized low-density lipoprotein derived aldehyde-4-hydroxy trans-2-nonenal in vascular smooth muscle cells

AU - Srivastava, Sanjay

AU - Conklin, Daniel J.

AU - Liu, Si Qi

AU - Prakash, Nidhi

AU - Boor, Paul J.

AU - Srivastava, Satish

AU - Bhatnagar, Aruni

PY - 2001

Y1 - 2001

N2 - Oxidation of low-density lipoproteins (LDL) generates high concentrations of unsaturated aldehydes, such as 4-hydroxy trans-2-nonenal (HNE). These aldehydes are mitogenic to vascular smooth muscle cells and sustain a vascular inflammation. Nevertheless, the processes that mediate and regulate the vascular metabolism of these aldehydes have not been examined. In this communication, we report the identification of the major metabolic pathways and products of [3H]-HNE in rat aortic smooth muscle cells in culture. High-performance liquid chromatography separation of the radioactivity recovered from these cells revealed that a large (60-65%) proportion of the metabolism was linked to glutathione (GSH). Electrospray mass spectrometry showed that glutathionyl-1,4 dihydroxynonene (GS-DHN) was the major metabolite of HNE in these cells. The formation of GS-DHN appears to be due aldose reductase (AR)-catalyzed reduction of glutathionyl 4-hydroxynonanal (GS-HNE), since inhibitors of AR (tolrestat or sorbinil) prevented GS-DHN formation, and increased the fraction of the glutathione conjugate remaining as GS-HNE. Gas chromatography-chemical ionization mass spectroscopy of the metabolites identified a subsidiary route of HNE metabolism leading to the formation of 4-hydroxynonanoic acid (HNA). Oxidation to HNA accounted for 25-30% of HNE metabolism. The formation of HNA was inhibited by cyanamide, indicating that the acid is derived from an aldehyde dehydrogenase (ALDH)-catalyzed pathway. The overall rate of HNE metabolism was insensitive to inhibition of AR or ALDH, although inhibition of HNA formation by cyanamide led to a corresponding increase in the fraction of HNE metabolized by the GSH-linked pathway, indicating that ALDH-catalyzed oxidation competes with glutathione conjugation. These metabolic pathways may be the key regulators of the vascular effects of HNE and oxidized LDL.

AB - Oxidation of low-density lipoproteins (LDL) generates high concentrations of unsaturated aldehydes, such as 4-hydroxy trans-2-nonenal (HNE). These aldehydes are mitogenic to vascular smooth muscle cells and sustain a vascular inflammation. Nevertheless, the processes that mediate and regulate the vascular metabolism of these aldehydes have not been examined. In this communication, we report the identification of the major metabolic pathways and products of [3H]-HNE in rat aortic smooth muscle cells in culture. High-performance liquid chromatography separation of the radioactivity recovered from these cells revealed that a large (60-65%) proportion of the metabolism was linked to glutathione (GSH). Electrospray mass spectrometry showed that glutathionyl-1,4 dihydroxynonene (GS-DHN) was the major metabolite of HNE in these cells. The formation of GS-DHN appears to be due aldose reductase (AR)-catalyzed reduction of glutathionyl 4-hydroxynonanal (GS-HNE), since inhibitors of AR (tolrestat or sorbinil) prevented GS-DHN formation, and increased the fraction of the glutathione conjugate remaining as GS-HNE. Gas chromatography-chemical ionization mass spectroscopy of the metabolites identified a subsidiary route of HNE metabolism leading to the formation of 4-hydroxynonanoic acid (HNA). Oxidation to HNA accounted for 25-30% of HNE metabolism. The formation of HNA was inhibited by cyanamide, indicating that the acid is derived from an aldehyde dehydrogenase (ALDH)-catalyzed pathway. The overall rate of HNE metabolism was insensitive to inhibition of AR or ALDH, although inhibition of HNA formation by cyanamide led to a corresponding increase in the fraction of HNE metabolized by the GSH-linked pathway, indicating that ALDH-catalyzed oxidation competes with glutathione conjugation. These metabolic pathways may be the key regulators of the vascular effects of HNE and oxidized LDL.

KW - 4-Hydroxy-trans-2-nonenal

KW - Aldose reductase

KW - Atherosclerosis

KW - Glutathione conjugates

KW - Lipid peroxidation

KW - Vascular smooth muscle cells

UR - http://www.scopus.com/inward/record.url?scp=0034816167&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0034816167&partnerID=8YFLogxK

U2 - 10.1016/S0021-9150(01)00454-3

DO - 10.1016/S0021-9150(01)00454-3

M3 - Article

C2 - 11583712

AN - SCOPUS:0034816167

VL - 158

SP - 339

EP - 350

JO - Atherosclerosis

JF - Atherosclerosis

SN - 0021-9150

IS - 2

ER -