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Objective@#To explore the imaging characteristics and related influencing factors of in-stent neoatherosclerosis (ISNA) in patients with restenosis after drug-eluting stent(DES) implantation with optical coherence tomography(OCT).@*Methods@#A total of 25 cases of coronary heart disease patients(DES placement time ≥8 months) with coronary artery angiography showing DES in-stent restenosis (ISR) in Zunyi medical college affiliated hospital from July 2013 to December 2015 were included in this study and patient's data were retrospectively analyzed.In these patients with ISR, OCT images were acquired before percutaneous coronary intervention. Patients were divided into the ISNA group (12 patients and 12 lesions) and non-ISNA group(13 patients and 13 lesions) according to the result of OCT. ISNA on OCT was defined as neointima formation with the presence of lipids or calcification.@*Results@#(1) The incidence of chronic kidney disease and increased low-density lipoprotein cholesterol level in ISNA group were significant higher than that in non-ISNA group(all P<0.05). The stent implantation time in ISNA group was longer than that in the non-ISNA group(53.0(14.0, 81.0) months vs. 15.0(8.5, 32.5) months, P<0.01). In addition, clinical manifestation of acute coronary syndrome was present in 8 out of 12 patientsin ISNA group, and stable angina pectoris was found in 10 out of 13 casesin non-ISNA group(P<0.01). (2) Quantitative analysis of OCT showed that the lumen area was less in ISNA group than in non-ISNA group((3.45±1.82)mm2 vs. (4.17±1.68)mm2, P<0.01), and neointimal area(3.89(2.26, 5.52)mm2 vs. 2.96(1.99, 4.22)mm2, P<0.01), neointimal load (53.15(40.18, 67.30)% vs. 41.54(32.08, 56.91)%, P<0.01), neointimal thickness(0.98(0.63, 1.36)μm vs. 0.72(0.51, 1.03)μm, P<0.01) were higher in ISNA group than in non-ISNA group.(3)Qualitative analysis of OCT showed that the prevalence of homogeneous intima was less in the ISNA group than in the non-ISNA group ((41.42±22.56)% vs.(72.06±18.68)%, P<0.05), on the contrary, the heterogeneous intima was more common in the ISNA group ((58.57±22.56)% vs. (27.94±18.68)%, P<0.05). There was no significant difference between two groups in the peri-stentmicrovessels (9/12 vs. 5/13,P>0.05), and prevalence of intraintimalmicrovessels was higher in the ISNA group than in non-ISNA group (7/12 vs. 2/13, P<0.05). In addition, thin cap fibrous plaque(7/12 vs. 0, P<0.01), disrupted intima with visible cavity (7/12 vs. 1/13, P<0.05),andintraluminal red thrombus(7/12 vs. 1/13, P<0.05) were significantly higher in ISNA group than in non-ISNA group.@*Conclusions@#Results of OCT show that ISNA occurs frequently in patients with ISR after DES implantation. The stent implantation time, incidence of chronic kidney disease and higher low-density lipoprotein cholesterol level are associated with the formation of ISNA in these patients.
ABSTRACT
Objective@#To explored the effect and related mechanism of miRNA-21 on hydrogen peroxide-induced C-kit+ cardiac stem cells apoptosis.@*Methods@#C-kit+ cardiac stem cells were isolated from SD rats by the methods of enzyme digestion and magnetic bead. Cells were divided into the following experimental groups: (1) negative control mimics (NCM)group: cells were transfected with negative control miRNA-21 mimics for 48 hours; (2)mimics group: cells were transfected with miRNA-21 mimics for 48 hours; (3) NCM+ H2O2 group: negative control miRNA-21 mimics were transfected into cells for 48 hours and then treated with 100 μmol H2O2 for 2 hours; (4)mimics+ H2O2 group: miRNA-21 mimics were transfected into cells for 48 hours and then treated with 100 μmol H2O2 for 2 hours. mRNA of miRNA-21 was detected by RT-PCR. The apoptosis rate of C-kit+ cardiac stem cells was determined using the annexin V-FITC/PI staining assay. Western blot was employed to measure the expression of apoptosis related proteins(Caspase-3, Bax, and Bcl-2).@*Results@#(1) Compared with the NCM group, the mRNA expression level of miRNA-21 was significantly up-regulated in mimics group, while obviously down-regulated in NCM+ H2O2 group(all P<0.05). Compared with the mimics group, the mRNA expression levels of miRNA-21 in mimics+ H2O2 group was significantly downregulated (P<0.05), but remarkably upregulated compared with the NCM+ H2O2 group(P<0.05). (2) Flow cytometry results indicated that the early apoptosis rates were similar between the NCM group and mimics group ((4.57±3.45)% vs. (5.13±3.21)%, P>0.05). Compared with the NCM group, the early apoptosis rates were remarkably increased ((79.07±5.75)% vs.(4.57±3.45)%, P<0.05) in NCM+ H2O2 group. Compared with the mimics group, the early apoptosis was significantly up-regulated in the mimics+ H2O2 group ((30.27±1.36)% vs.(5.13±3.21)%, P<0.05), which were further down-regulated in mimics+ H2O2 group compared with the NCM+ H2O2 group ((30.27±1.36)% vs.(79.07±5.75)%, P<0.05). (3) Western blot results showed similar protein expression of Caspase-3, Bax and Bcl-2 between NCM group and mimics group(all P>0.05). Compared with the NCM group, the Caspase-3 and Bax protein expression was significantly increased in NCM+ H2O2 group (all P<0.05), but the protein expression level of Bcl-2 was similar between the 2 groups(P>0.05). The Caspase-3 and Bax protein expression was markedly decreased, while Bcl-2 apparently increased in the mimics+ H2O2 group compared with the NCM+ H2O2 group(all P<0.05).@*Conclusion@#Overexpression of miRNA-21 protects the C-kit+ cardiac stem cells from apoptosis caused by oxidative stress through downregulating proapoptotic and upregulating the antiapoptotic proteins.
ABSTRACT
AIM: To investigate the function and the mechanism of transplanting bone marrow derived peripheral blood mesenchymal stem cells(PBMSCs) on restenosis after carotid balloon angioplasty in the model of carotid atherosclerosis rabbits,and to determine if the functions of PBMSCs are enhanced after hypoxia preconditioning.METHODS: Bone marrow cells were mobilized by granulocyte colony-stimulating factor(G-CSF),and PBMSCs were collected through density gradient centrifugation and adherent culture,labeled with enhancement type green fluorescent protein(EGFP) genes.All animals with carotid atherosclerosis stenosis were randomly divided into three groups: hypoxia preconditioning group(n=24,received intravenous transplantation of PBMSCs with hypoxia preconditioning),non-hypoxia preconditioning group(n=24,received normal culture of PBMSCs) and control group(n=24,only received equal-volume of culture medium).Vascular endothelial growth factor(VEGF) was determined by enzyme linked immunosorbent assay(ELISA) at 7 d,14 d and 28 d post-angioplasty,respectively.The vessel morphology,the homing of MSCs and the reendothelialization were analyzed with Weigert staining and immunohistochemistry.RESULTS: Compared to control group,the level of VEGF significantly increased in both hypoxia preconditioning group and non-hypoxia preconditioning group at all time points(P