BackgroundCirculating endothelial progenitor cells (EPCs) reflect endothelial repair capacity and may be a significant marker for the clinical outcomes of cardiovascular disease. While some high-dose statin treatments may improve endothelial function, it is not known whether different statins may have similar effects on EPCs.This study aimed to investigate the potential class effects of different statin treatment including pitavastatin and atorvastatin on circulating EPCs in clinical setting.MethodsA pilot prospective, double-blind, randomized study was conducted to evaluate the ordinary dose of pitavastatin (2 mg daily) or atorvastatin (10 mg daily) treatment for 12 weeks on circulating EPCs in patients with cardiovascular risk such as hypercholesterolemia and type 2 diabetes mellitus (T2DM). Additional in vitro study was conducted to clarify the direct effects of both statins on EPCs from the patients.ResultsA total of 26 patients (19 with T2DM) completed the study. While the lipid-lowering effects were similar in both treatments, the counts of circulating CD34+KDR+EPCs were significantly increased (from 0.021 ± 0.015 to 0.054 ± 0.044% of gated mononuclear cells, P < 0.05) only by pitavastatin treatment. Besides, plasma asymmetric dimethylarginine level was reduced (from 0.68 ± 0.10 to 0.53 ± 0.12 μmol/L, P < 0.05) by atorvastatin, and plasma vascular endothelial growth factor (VEGF) level was increased (from 74.33 ± 32.26 to 98.65 ± 46.64 pg/mL, P < 0.05) by pitavastatin. In the in vitro study, while both statins increased endothelial nitric oxide synthase (eNOS) expression, only pitavastatin increased the phosphorylation of eNOS in EPCs. Pitavastatin but not atorvastatin ameliorated the adhesion ability of early EPCs and the migration and tube formation capacities of late EPCs.ConclusionsWhile both statins similarly reduced plasma lipids, only pitavastatin increased plasma VEGF level and circulating EPCs in high-risk patients, which is probably related to the differential pleiotropic effects of different statins.Trial registrationThis trial is registered at ClinicalTrials.gov, NCT01386853.

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Background: Plasma advanced glycation end products (AGEs) activates the receptor for advanced glycation end products (RAGE) and the activation of RAGE is implicated to be the pathogenesis of type 2 diabetic mellitus patient vascular complications. Attenuating the activation of RAGE may exert a protective effect against the development of cardiovascular disease. Dipeptidyl peptidase-4 (DPP4) inhibitors are a new class of oral hypoglycemic agents for the treatment of type 2 diabetes mellitus. Whether sitagliptin, a DPP-4 inhibitor, has a beneficial effect on vascular calcification remains undetermined. Methods: In the present study, we fed low-density lipoprotein receptor knockout (LDLR-/-) mice a high fat diet to induce diabetic mellitus and studied the effect of orally administered sitagliptin on the high fat diet fed LDLR-/- mice aorta medial calcification, RAGE expression, oxidative stress, aorta calcium content. Tumor necrosis factor (TNF)-α combined with S100A12 was used to induce HASMC oxidative stress, activation of NADPH, up-regulation of the bone markers and RAGE expression, and cell calcium deposition. Effect of sitagliptin, siRNA for RAGE and apocynin on blunting TNF-α and S100A12 induced HASMC oxidative stress, calcification and NADPH activation were also investigated. Results: Sitagliptin attenuated the HFD-induced LDLR-/- mice hyperlipidemia, hyperglycemia, increase in serum TNF-α, aorta calcium deposition and the expression of RAGE in the medial layer of the aorta. TNF-α combined with S100A12 stimulated HASMC RAGE expression, calcium deposition, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (Nox) activation, and up-regulation of bone marker (bone morphogenetic protein-2, Msh homeobox 2, and runt‑related transcription factor 2) expression. Sitagliptin and apocynin (APO), an NADPH oxidase inhibitor, suppressed the TNF-α+S100A12 treatment effects on the activation of NADPH oxidase and Nuclear factor (NF)-κB and the resultant oxidative stress, up-regulation of RAGE and bone markers expression and calcium deposition. Our findings suggest that sitagliptin imparts its protective effect by suppressing NADPH oxidase and NF-κB activation to blunt the up-regulation of RAGE expression.Conclusion: Our findings suggest that sitagliptin may suppress the initiation and progression of artery calcification by inhibiting the activation of NADPH oxidase and NF-κB and the resultant up-regulation of expression of RAGE.

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Abdominal aortic aneurysm (AAA) is a multifactorial cardiovascular disease with a high risk of death, and it occurs in the infrarenal aorta with vascular dilatation. High blood pressure acts on the aortic wall, resulting in rupture and causing life-threatening intra-abdominal hemorrhage. Vascular smooth muscle cell (VSMC) dysregulation and extracellular matrix (ECM) degradation, especially elastin breaks, contribute to structural changes in the aortic wall. The pathogenesis of AAA includes the occurrence of oxidative stress, inflammatory cell infiltration, elastic fiber fragmentation, VSMC apoptosis, and phenotypic transformation. Tributyrin (TB) is decomposed by intestinal lipase and has a function similar to that of butyrate. Whether TB has a protective effect against AAA remains uncertain. In the present study, we established an AAA murine model by angiotensin II (AngII) induction in low-density lipoprotein receptor knockout (LDLR-/-) mice and investigated the effects of orally administered TB on the AAA size, ratio of macrophage infiltration, levels of matrix metalloproteinase (MMP) expression, and epigenetic regulation. TB attenuates AngII-induced AAA size and decreases elastin fragmentation, macrophage infiltration, and MMP expression in the medial layer of the aorta and reduces the levels of SBP (systolic blood pressure, p < 0.001) and MMP-2 (p < 0.02) in the serum. TB reduces the AngII-stimulated expression levels of MMP2 (p < 0.05), MMP9 (p < 0.05), MMP12, and MMP14 in human aortic smooth muscle cells (HASMCs). Moreover, TB and valproic acid (VPA), a histone deacetylase (HDAC) inhibitor, suppress AngII receptor type 1 (AT1R, p < 0.05) activation and increase the expression of acetyl histone H3 by HDAC activity inhibition (p < 0.05). Our findings suggest that TB exerts its protective effect by suppressing the activation of HDAC to attenuate the AngII-induced AT1R signaling cascade.