[Show abstract][Hide abstract] ABSTRACT: Aims
We elucidated the therapeutic potential of human umbilical vein endothelial cells (HUVECs) for ameliorating progressive heart failure in a myocardial infarction (MI) rat model.
MI was induced by ligation of left anterior descending artery, and HUVEC was transplanted 1 week after MI. Cardiac function was evaluated by echocardiography, and histological analyses were performed.
Phosphate-buffered saline (MI-V, n = 5) or HUVEC (MI-HV, n = 5) were injected into the border zone and infarcted area 7 days after ligation of the left coronary artery in rats. The MI-HV group showed attenuation of left ventricular (LV) remodeling compared with the MI-V group. In the infarcted myocardium, a few of injected HUVEC was retained up to 28 days. The ratios of matrix metalloproteinase (MMP)-2 or MMP-9 to tissue inhibitor of metalloproteinase (TIMP)-1 or TIMP-3 were decreased MI-HV group compared with MI-V group. In vivo zymography analysis showed that HUVEC transplantation decreased the activities of MMP-2 and MMP-9. In immunohistochemistry, decreased MMP-2 and increased TIMP-1 and TIMP-3 expression were observed at 48 hours after HUVEC transplantation. These effects on MMP/TIMP balance were inhibited by L-NAME administration (an eNOS inhibitor, 10 mg/kg). NOS inhibition decreased the protein expressions of TIMP-1 and TIMP-3 but did not change the protein expressions of MMP-2 and MMP-9.
Our data suggest that altered balance between MMP and TIMP by HUVEC transplantation contributed to attenuation of ventricular remodeling after MI via eNOS.
[Show abstract][Hide abstract] ABSTRACT: The cellular and molecular mechanisms and safety after drug-eluting stent (DES) implantation in diabetic patients are still poorly understood; therefore, in this study, we evaluated the pathologic responses of the sirolimus-eluting stent (SES) or paclitaxel-eluting stent (PES) in a type I diabetes mellitus (DM) rat model.
The type I DM rat model was manipulated by intra-peritoneal streptozotocin injection. Two weeks later, DES was implanted in the aorta of rats with hyperglycemia or not as a control. Four weeks after DES implantation, the stented aorta was isolated and histomorphometric analysis was performed.
On histomorphometric analysis, increased thrombus, inflammatory cell infiltration, and neointimal hyperplasia (NIH) without change of the smooth muscle cell number after DES implantation were observed in DM rats compared with non-DM (NDM) rats. Furthermore, delayed coverage of mature endothelial cells defined as a von Willebrand factor expression and increased immature endothelial cells as a c-kit expression after DES implantation were observed in DM rats compared with NDM rats. Increased fibrin deposition and decreased hyaluronic acid accumulation at NIH after DES implantation were also observed in DM rats compared with NDM rats.
In conclusion, the main mechanism of restenosis after DES implantation under hyperglycemic conditions was initial thrombus with changes of the extracellular matrix rather than SMC proliferation. These results provided a therapeutic clue for the selection of DES and application of combination therapy using anti-thrombotic and anti-inflammatory drugs in diabetic patients.
No preview · Article · Jun 2011 · Journal of atherosclerosis and thrombosis
[Show abstract][Hide abstract] ABSTRACT: Mast cells are multifunctional cells containing various mediators, such as cytokines, tryptase, and histamine, and they have been identified in infarct myocardium. Here, we elucidated the roles of mast cells in a myocardial infarction (MI) rat model. We studied the physiological and functional roles of mast cell granules (MCGs), isolated from rat peritoneal fluid, on endothelial cells, neonatal cardiomyocytes, and infarct heart (1-hour occlusion of left coronary artery followed by reperfusion). The number of mast cells had two peak time points of appearance in the infarct region at 1day and 21days after MI induction in rats (p<0.05 in each compared with sham-operated heart). Simultaneous injection of an optimal dose of MCGs modulated the microenvironment and resulted in the increased infiltration of macrophages and decreased apoptosis of cardiomyocytes without change in the mast cell number in infarct myocardium. Moreover, MCG injection attenuated the progression of MI through angiogenesis and preserved left ventricular function after MI. MCG-treated cardiomyocytes were more resistant to hypoxic injury through phosphorylation of Akt, and MCG-treated endothelial cells showed enhanced migration and tube formation. We have shown that MCGs have novel cardioprotective roles in MI via the prolonged survival of cardiomyocytes and the induction of angiogenesis.
No preview · Article · Feb 2011 · Journal of Molecular and Cellular Cardiology
[Show abstract][Hide abstract] ABSTRACT: Thermo-responsive hydrogel-mediated gene transfer may be preferred for the muscle, because the release of DNA into the surrounding tissue can be controlled by the 3-dimensional structure of the hydrogel. Such a system for the controlled release of a therapeutic gene may extend the duration of gene expression. Here, a thermo-responsive, biodegradable polymeric hydrogel was synthesized for local gene transfer in the heart. Initially, the luciferase gene was delivered into mouse heart. The intensity of gene expression assessed by optical imaging was closely correlated with the expressed protein concentration measured by luciferase assay in homogenized heart. Polymeric hydrogel-based gene transfer enhanced gene expression up to 4 fold, compared with naked plasmid, and displayed 2 bi-modal expression profiles with peaks at 2 days and around 25 days after local injection. Histological analyses showed that gene expression was initially highest in the myocardium, whereas lower and longer expression was seen mainly in fibrotic or inflammatory cells that infiltrated the injury site during injection. Next, a rat myocardial infarction model was made for 1 week, and human vascular endothelial growth factor (hVEGF) plasmid was injected into the infarct area with an amphiphilic thermo-responsive polymer. Enhanced and sustained hVEGF expression in the infarct region mediated by amphiphilic thermo-responsive polymer increased capillary density and larger vessel formation, thus enabling effective angiogenesis.
No preview · Article · Jun 2009 · Journal of Controlled Release