Impact of folic acid administration in homocysteine levels, inflammation and in atherosclerotic plaque area in apoE deficient mice

Smooth muscle cells (SMC) are known to migrate and proliferate to form a stabilizing fibrous cap that encapsulates atherosclerotic plaques. It has been shown that CD98hc, a transmembrane protein with a known role in amino acid transport and integrin signaling, is involved in proliferation and survival of various cell types including SMC. Based on these data, we hypothesized that CD98hc deficiency selectively in SMC would have pathogenic effects on atherosclerosis development and plaque composition. To test this, we utilized mice with SMC-specific deletion of the CD98hc ( CD98hc fl/fl SM22Cre + ) to determine the effects of CD98hc deficiency on SMC function in the context of atherosclerosis. We performed in vitro proliferation and survival/apoptosis assays to investigate the role of CD98hc in the proliferation and survival of primary mouse aortic vascular smooth muscle cells. We found that VSMC isolated from whole aortas of CD98hc -/- animals displayed approximately 60% reduced cell counts compared to control (41 ± 8.2% of control) after 5 days in culture. EdU assays in vivo showed a defect in the ability of CD98hc -/- SMC to proliferate, with 25% reduction in EdU-positive VSMC compared to controls (2.3 ± 0.2% vs 3 ± 0.2%). In addition, caspase-3 staining of SMC in vitro displayed a 41% increase in propensity of CD98hc -/- SMC to undergo apoptosis compared to controls (7.9 ± 0.6% vs 5.6 ± 0.5%). Furthermore, the absence of CD98hc in SMC caused a sharp increase in phosphorylated p-38, which was partially abrogated towards control levels when the cells were treated with PDGF-BB to induce proliferation. Long-term atherosclerosis study using SMC-CD98hc -/- /LDLR -/- mice showed that atherosclerotic plaque morphology was altered with increased necrotic core area (25.8 ± 1.9% vs 10.9 ± 1.6% necrotic core area per plaque area) due to a reduction in infiltration of SMC within the plaque (2.1 ± 0.4% vs 4.3 ± 0.4% SM22α positive area per plaque area) compared to control LDLR -/- mice. These data support an important role for CD98hc and its regulation of p-38 MAP kinase signaling in aortic vascular smooth muscle cell proliferation and survival. We conclude that CD98hc is critical for the formation of fibrous cap that is important in maintaining the stability of atherosclerotic plaque.

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5-Aminolevulinic Acid Attenuates Atherosclerotic Plaque Progression in Low-Density Lipoprotein Receptor-Deficient Mice by Heme Oxygenase-1 Induction

Circulation Reports ◽

10.1253/circrep.cr-19-0089 ◽

2020 ◽

Vol 2 (1) ◽

pp. 60-68

Author(s):

Kohsuke Hagisawa ◽

Makoto Ayaori ◽

Katsunori Ikewaki ◽

Motowo Nakajima ◽

Yuji Morimoto

Keyword(s):

Atherosclerotic Plaque ◽

Aminolevulinic Acid ◽

Low Density Lipoprotein ◽

Density Lipoprotein ◽

Heme Oxygenase 1 ◽

Low Density ◽

Lipoprotein Receptor ◽

Plaque Progression ◽

Density Lipoprotein Receptor ◽

Deficient Mice

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Abstract 276: Systemic Delivery of Microrna-146a Improves Endothelial Function and Ameliorates Atherosclerosis in Apolipoprotein E-deficient Mice

Circulation Research ◽

10.1161/res.117.suppl_1.276 ◽

2015 ◽

Vol 117 (suppl_1) ◽

Author(s):

Shuangtao Ma ◽

Xiao Yu Tian ◽

Chaofeng Mu ◽

Haifa Shen ◽

Yunrong Zhang ◽

...

Keyword(s):

Endothelial Function ◽

Apolipoprotein E ◽

Carotid Arteries ◽

Treated Group ◽

Vehicle Group ◽

Early Event ◽

Aortic Tissue ◽

Systemic Delivery ◽

Plaque Area ◽

Deficient Mice

Rationale: Endothelial inflammation is an early event in the development of atherosclerosis. The microRNA (miR)-146a showed anti-inflammatory effects in cultured endothelial cells. In this study, we investigated the therapeutic role of miR-146a in endothelial function and atherosclerosis in apolipoprotein E (ApoE)-deficient mice. Methods and Results: The miR-146a was packaged into a multistage vector (MSV) that was conjugated with an E-selectin-targeting thioaptamer (ESTA) to form an ESTA-MSV microparticle. The ApoE-deficient mice were fed with Western diet and injected through tail vein with 15μg of miR-146a loaded ESTA-MSV microparticles or vehicle vectors biweekly for 12 weeks. The expressions of miR-146a in aortic tissue was increased by five times at two weeks after injection. However, the expressions of miR-146a in heart, lung, liver, spleen, kidney, and skeletal muscle were not increased. The acetylcholine-induced endothelium-dependent relaxations in both carotid arteries and aortas were significantly improved in mice from miR-146a treated group compared with vehicle group. In addition, the endothelium-dependent contractions of carotid arteries were also improved by miR-146a treatment. The en face oil red O staining of whole aortas showed the plaque area was decreased in miR-146a-treated mice. Application of miR-146a also decreased the plaque size, macrophages, and T-lymphocytes, but increased the collagen deposition and vascular smooth muscle cells in the sections of aortic roots. The PCR results showed that expressions of chemokine (C-C motif) ligand (CCL)-2, CCL-5, and CCL-8 were decreased by miR-146a. Conclusions: E-selectin-targeting delivery of miR-146a improves endothelial function and inhibits atherosclerosis.

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