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Imaging of Intracellular and Extracellular ROS Levels in Atherosclerotic Mouse Aortas Ex Vivo: Effects of Lipid Lowering by Diet or Atorvastatin.

Ekstrand M, Gustafsson Trajkovska M, Perman-Sundelin J, Fogelstrand P, Adiels M, Johansson M, Mattsson-Hultén L, Borén J, Levin M - PLoS ONE (2015)

Bottom Line: Atorvastatin treatment did not affect lesion inflammation (aortic arch mRNA levels of CXCL 1, ICAM-1, MCP-1, TNF-α, VCAM, IL-6, and IL-1β) or cellular composition (smooth muscle cell, macrophage, and T-cell content).Our results suggest that within lesions, macrophages produce mainly intracellular ROS whereas smooth muscle cells produce extracellular ROS.Short term atorvastatin treatment, but not lipid lowering by diet, decreases ROS levels within established advanced lesions; this may help explain the lesion stabilizing and anti-inflammatory effects of long term statin treatment.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular and Clinical Medicine/Wallenberg Laboratory, University of Gothenburg and Sahlgrenska University Hospital, SE-413 45, Gothenburg, Sweden.

ABSTRACT

Objective: The first objective was to investigate if intracellular and extracellular levels of reactive oxygen species (ROS) within the mouse aorta increase before or after diet-induced lesion formation. The second objective was to investigate if intracellular and extracellular ROS correlates to cell composition in atherosclerotic lesions. The third objective was to investigate if intracellular and extracellular ROS levels within established atherosclerotic lesions can be reduced by lipid lowering by diet or atorvastatin.

Approach and results: To address our objectives, we established a new imaging technique to visualize and quantify intracellular and extracellular ROS levels within intact mouse aortas ex vivo. Using this technique, we found that intracellular, but not extracellular, ROS levels increased prior to lesion formation in mouse aortas. Both intracellular and extracellular ROS levels were increased in advanced lesions. Intracellular ROS correlated with lesion content of macrophages. Extracellular ROS correlated with lesion content of smooth muscle cells. The high levels of ROS in advanced lesions were reduced by 5 days high dose atorvastatin treatment but not by lipid lowering by diet. Atorvastatin treatment did not affect lesion inflammation (aortic arch mRNA levels of CXCL 1, ICAM-1, MCP-1, TNF-α, VCAM, IL-6, and IL-1β) or cellular composition (smooth muscle cell, macrophage, and T-cell content).

Conclusions: Aortic levels of intracellular ROS increase prior to lesion formation and may be important in initiation of atherosclerosis. Our results suggest that within lesions, macrophages produce mainly intracellular ROS whereas smooth muscle cells produce extracellular ROS. Short term atorvastatin treatment, but not lipid lowering by diet, decreases ROS levels within established advanced lesions; this may help explain the lesion stabilizing and anti-inflammatory effects of long term statin treatment.

No MeSH data available.


Related in: MedlinePlus

Lipid lowering by diet does not affect ROS levels within the atherosclerotic aortic arch Female Apoe-/- mice were first fed Western diet to induce advanced lesions in the aortic arch.Then, lipids were lowered by switching to chow diet for five days. A control group was maintained on Western diet. (A) Intracellular and extracellular ROS were assessed in the atherosclerotic arch (red). (B) Lipid lowering by diet did not affect intracellular ROS. (C) Lipid lowering by diet did not affect extracellular ROS. NS—non significant. One sample t-test. n = 6 in each group.
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pone.0130898.g004: Lipid lowering by diet does not affect ROS levels within the atherosclerotic aortic arch Female Apoe-/- mice were first fed Western diet to induce advanced lesions in the aortic arch.Then, lipids were lowered by switching to chow diet for five days. A control group was maintained on Western diet. (A) Intracellular and extracellular ROS were assessed in the atherosclerotic arch (red). (B) Lipid lowering by diet did not affect intracellular ROS. (C) Lipid lowering by diet did not affect extracellular ROS. NS—non significant. One sample t-test. n = 6 in each group.

Mentions: We then investigated if diet-induced or pharmacologically induced lipid lowering affects ROS in atherosclerotic lesions. We first tested if diet-induced lipid lowering reduces ROS levels in atherosclerotic lesions. To this end, one group of Apoe-/- mice was fed Western diet for 7 weeks and another group had Western diet replaced by chow diet for the last 5 days. Diet-induced lipid lowering did not change intracellular or extracellular ROS levels within lesions (Fig 4). Thus, short term lipid lowering does not influence ROS levels within atherosclerotic lesions.


Imaging of Intracellular and Extracellular ROS Levels in Atherosclerotic Mouse Aortas Ex Vivo: Effects of Lipid Lowering by Diet or Atorvastatin.

Ekstrand M, Gustafsson Trajkovska M, Perman-Sundelin J, Fogelstrand P, Adiels M, Johansson M, Mattsson-Hultén L, Borén J, Levin M - PLoS ONE (2015)

Lipid lowering by diet does not affect ROS levels within the atherosclerotic aortic arch Female Apoe-/- mice were first fed Western diet to induce advanced lesions in the aortic arch.Then, lipids were lowered by switching to chow diet for five days. A control group was maintained on Western diet. (A) Intracellular and extracellular ROS were assessed in the atherosclerotic arch (red). (B) Lipid lowering by diet did not affect intracellular ROS. (C) Lipid lowering by diet did not affect extracellular ROS. NS—non significant. One sample t-test. n = 6 in each group.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4476734&req=5

pone.0130898.g004: Lipid lowering by diet does not affect ROS levels within the atherosclerotic aortic arch Female Apoe-/- mice were first fed Western diet to induce advanced lesions in the aortic arch.Then, lipids were lowered by switching to chow diet for five days. A control group was maintained on Western diet. (A) Intracellular and extracellular ROS were assessed in the atherosclerotic arch (red). (B) Lipid lowering by diet did not affect intracellular ROS. (C) Lipid lowering by diet did not affect extracellular ROS. NS—non significant. One sample t-test. n = 6 in each group.
Mentions: We then investigated if diet-induced or pharmacologically induced lipid lowering affects ROS in atherosclerotic lesions. We first tested if diet-induced lipid lowering reduces ROS levels in atherosclerotic lesions. To this end, one group of Apoe-/- mice was fed Western diet for 7 weeks and another group had Western diet replaced by chow diet for the last 5 days. Diet-induced lipid lowering did not change intracellular or extracellular ROS levels within lesions (Fig 4). Thus, short term lipid lowering does not influence ROS levels within atherosclerotic lesions.

Bottom Line: Atorvastatin treatment did not affect lesion inflammation (aortic arch mRNA levels of CXCL 1, ICAM-1, MCP-1, TNF-α, VCAM, IL-6, and IL-1β) or cellular composition (smooth muscle cell, macrophage, and T-cell content).Our results suggest that within lesions, macrophages produce mainly intracellular ROS whereas smooth muscle cells produce extracellular ROS.Short term atorvastatin treatment, but not lipid lowering by diet, decreases ROS levels within established advanced lesions; this may help explain the lesion stabilizing and anti-inflammatory effects of long term statin treatment.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular and Clinical Medicine/Wallenberg Laboratory, University of Gothenburg and Sahlgrenska University Hospital, SE-413 45, Gothenburg, Sweden.

ABSTRACT

Objective: The first objective was to investigate if intracellular and extracellular levels of reactive oxygen species (ROS) within the mouse aorta increase before or after diet-induced lesion formation. The second objective was to investigate if intracellular and extracellular ROS correlates to cell composition in atherosclerotic lesions. The third objective was to investigate if intracellular and extracellular ROS levels within established atherosclerotic lesions can be reduced by lipid lowering by diet or atorvastatin.

Approach and results: To address our objectives, we established a new imaging technique to visualize and quantify intracellular and extracellular ROS levels within intact mouse aortas ex vivo. Using this technique, we found that intracellular, but not extracellular, ROS levels increased prior to lesion formation in mouse aortas. Both intracellular and extracellular ROS levels were increased in advanced lesions. Intracellular ROS correlated with lesion content of macrophages. Extracellular ROS correlated with lesion content of smooth muscle cells. The high levels of ROS in advanced lesions were reduced by 5 days high dose atorvastatin treatment but not by lipid lowering by diet. Atorvastatin treatment did not affect lesion inflammation (aortic arch mRNA levels of CXCL 1, ICAM-1, MCP-1, TNF-α, VCAM, IL-6, and IL-1β) or cellular composition (smooth muscle cell, macrophage, and T-cell content).

Conclusions: Aortic levels of intracellular ROS increase prior to lesion formation and may be important in initiation of atherosclerosis. Our results suggest that within lesions, macrophages produce mainly intracellular ROS whereas smooth muscle cells produce extracellular ROS. Short term atorvastatin treatment, but not lipid lowering by diet, decreases ROS levels within established advanced lesions; this may help explain the lesion stabilizing and anti-inflammatory effects of long term statin treatment.

No MeSH data available.


Related in: MedlinePlus