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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

Atorvastatin reduces intracellular and extracellular ROS levels within the atherosclerotic aortic arch.Female Apoe-/- mice were fed Western diet to induce advanced atherosclerotic lesions in the aortic arch. Then, mice were treated with vehicle (DMSO) or oral atorvastatin (100 mg/kg per day) for 5 days. (A) ROS levels were analyzed in the aortic arch (red areas). (B–D) Atorvastatin treatment reduced intracellular (B and C) and extracellular ROS levels (D). (E and F) Plasma cholesterol (E) and triglycerides (F) was reduced by atorvastatin and, to larger extent, by lipid lowering by diet. n = 6 in each group. **p<0.01 vs vehicle, *p<0.05 vs vehicle. One sample t-test (C and D). ANOVA with Dunnet’s test for multiple comparisons (E and F).
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pone.0130898.g006: Atorvastatin reduces intracellular and extracellular ROS levels within the atherosclerotic aortic arch.Female Apoe-/- mice were fed Western diet to induce advanced atherosclerotic lesions in the aortic arch. Then, mice were treated with vehicle (DMSO) or oral atorvastatin (100 mg/kg per day) for 5 days. (A) ROS levels were analyzed in the aortic arch (red areas). (B–D) Atorvastatin treatment reduced intracellular (B and C) and extracellular ROS levels (D). (E and F) Plasma cholesterol (E) and triglycerides (F) was reduced by atorvastatin and, to larger extent, by lipid lowering by diet. n = 6 in each group. **p<0.01 vs vehicle, *p<0.05 vs vehicle. One sample t-test (C and D). ANOVA with Dunnet’s test for multiple comparisons (E and F).

Mentions: We then investigated if lipid lowering by atorvastatin intervention affects ROS levels within established atherosclerotic lesions. Atorvastatin was administered to Apoe-/- mice during the final 5 days on a 7 week Western diet. We used short treatment to avoid statin-induced changes in lesion composition since prolonged statin treatment is known to have anti-inflammatory and stabilizing effects on atherosclerotic lesions [13, 14, 19]. The short intervention with atorvastatin did not affect lesion area, lesion cell composition, or mRNA levels of inflammatory mediators in the aortic arch (Fig 5). However, atorvastatin significantly decreased both extracellular and intracellular ROS levels within the atherosclerotic aortic arch (Fig 6A and 6B). Interestingly, atorvastatin decreased plasma cholesterol and triglycerides less than diet induced lipid lowering (Fig 6C and 6D). Thus, atorvastatin treatment decreased ROS in atherosclerotic lesions but the effect was not linked to its lipid-lowering effect, changed lesion composition, or reduced inflammation.


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)

Atorvastatin reduces intracellular and extracellular ROS levels within the atherosclerotic aortic arch.Female Apoe-/- mice were fed Western diet to induce advanced atherosclerotic lesions in the aortic arch. Then, mice were treated with vehicle (DMSO) or oral atorvastatin (100 mg/kg per day) for 5 days. (A) ROS levels were analyzed in the aortic arch (red areas). (B–D) Atorvastatin treatment reduced intracellular (B and C) and extracellular ROS levels (D). (E and F) Plasma cholesterol (E) and triglycerides (F) was reduced by atorvastatin and, to larger extent, by lipid lowering by diet. n = 6 in each group. **p<0.01 vs vehicle, *p<0.05 vs vehicle. One sample t-test (C and D). ANOVA with Dunnet’s test for multiple comparisons (E and F).
© Copyright Policy
Related In: Results  -  Collection

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

pone.0130898.g006: Atorvastatin reduces intracellular and extracellular ROS levels within the atherosclerotic aortic arch.Female Apoe-/- mice were fed Western diet to induce advanced atherosclerotic lesions in the aortic arch. Then, mice were treated with vehicle (DMSO) or oral atorvastatin (100 mg/kg per day) for 5 days. (A) ROS levels were analyzed in the aortic arch (red areas). (B–D) Atorvastatin treatment reduced intracellular (B and C) and extracellular ROS levels (D). (E and F) Plasma cholesterol (E) and triglycerides (F) was reduced by atorvastatin and, to larger extent, by lipid lowering by diet. n = 6 in each group. **p<0.01 vs vehicle, *p<0.05 vs vehicle. One sample t-test (C and D). ANOVA with Dunnet’s test for multiple comparisons (E and F).
Mentions: We then investigated if lipid lowering by atorvastatin intervention affects ROS levels within established atherosclerotic lesions. Atorvastatin was administered to Apoe-/- mice during the final 5 days on a 7 week Western diet. We used short treatment to avoid statin-induced changes in lesion composition since prolonged statin treatment is known to have anti-inflammatory and stabilizing effects on atherosclerotic lesions [13, 14, 19]. The short intervention with atorvastatin did not affect lesion area, lesion cell composition, or mRNA levels of inflammatory mediators in the aortic arch (Fig 5). However, atorvastatin significantly decreased both extracellular and intracellular ROS levels within the atherosclerotic aortic arch (Fig 6A and 6B). Interestingly, atorvastatin decreased plasma cholesterol and triglycerides less than diet induced lipid lowering (Fig 6C and 6D). Thus, atorvastatin treatment decreased ROS in atherosclerotic lesions but the effect was not linked to its lipid-lowering effect, changed lesion composition, or reduced inflammation.

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