Fig 2: Cd39 deletion results in less necrosis in advanced lesions from Western diet-fed mice. A: Acellular necrotic area was measured by hematoxylin and eosin staining on aortic sinus. B: Intra-lesion apoptosis was evaluated by TUNEL assay on aortic sinus. C: Intra-lesion collagen content was quantified by Sirius red staining on aortic sinus. Necrotic and collagen-rich fibrotic areas were measured in four 50 µm distant sections per each animal, while the TUNEL-positive area was measured in one section per animal (n = 8 ApoE KO and 7 DKO mice for all the analyses). Representative images are shown (scale bar is 250 µm in (A) and (C), 50 µm in (B). All quantification data are presented as mean ± SEM of the percentage staining of the total plaque area. Setting a color threshold in ImageJ identified positive staining. **P < 0.01.

Fig 3: Cd39 deletion attenuates the formation of atherosclerotic lesions in ApoE-deficient mice. Male ApoE KO and DKO mice were fed a chow diet (n = 9 and 7 mice, respectively) (A) or a Western diet (n = 12 and 8 mice, respectively) (C) for up to 20 weeks and atherosclerotic lesion sizes were determined by Oil Red O staining of the whole aorta. Atherosclerotic lesions were also evaluated by Elastica van Gieson staining of the aortic root of ApoE KO and DKO mice fed a chow diet (n = 8 and 10 mice, respectively) (B) or a Western Diet (n = 7 mice in both groups) (D). Intimal plaque area was measured in four 50 µm distant sections per each animal. Data are presented as mean ± SEM. Representative images are shown. Scale bar in (B) and (D) is 250 µm. *P < 0.05; **P < 0.01.

Fig 4: Cd39 deletion results in higher HDL levels in serum from Western diet-fed mice. Peripheral blood from Western diet-fed ApoE KO and DKO mice was analyzed for levels of total cholesterol (A), LDL-C (B), and HDL-C (C) (n = 4–5 mice per group). Data are presented as mean ± SEM. **P < 0.01.

Fig 5: Cd39 deletion impairs platelet activation. A: In vitro aggregometry response of platelets from ApoE KO and DKO mice fed the standard chow diet following 2.5 μM ADP stimulation. Data are presented as percent of light transmission over the time of incubation. Trace 1 (blue): platelets from ApoE KO mice; trace 2 (black): platelets from DKO mice. Aggregometry response is representative of three ApoE KO and four DKO mice. B: In vivo platelet turnover in ApoE KO and DKO mice fed the standard chow diet. Platelets were labeled and then counted every 24 h for 4 days, as described in the Materials and Methods. Data are presented as mean ± SEM of the percentage of labeled platelets to total platelets over the time of analysis (n = 5 ApoE KO and 4 DKO mice). **P < 0.01, ***P < 0.001.