Moon Hwa Hong

Curcumin attenuates inflammatory responses of TNF-alpha-stimulated human endothelial cells.

Curcumin, a yellow pigment of turmeric in curry, is reported to interfere with nuclear factor (NF)-κB. This study was designed to investigate the underlying pathway of antiinflammation of curcumin on endothelial cells. Human umbilical vein endothelial cells (HUVECs) were stimulated with 10 ng/mL tumor necrosis factor (TNF)-α. Curcumin blocked the activation of NF-κB by TNF-α. Curcumin also reduced the intracellular reactive oxygen species (ROS), monocyte adhesion, phosphorylation of c-Jun N-terminal kinase (JNK), p38, and signal transducer and activator of transcription (STAT)-3 in TNF-α-stimulated HUVECs. The expression of intracellular cell adhesion molecule (ICAM)-1, monocyte chemoattractant protein (MCP)-1, and interleukin (IL)-8 were attenuated by curcumin at both mRNA and protein level. Curcumin, however, did not affect the expression of TNF receptor I and II in TNF-α-stimulated HUVECs. We suggest that curcumin could contribute to protection against the adverse vascular effect of the proinflammatory response through the modulation of p38 and STAT-3 in addition to NF-κB and JNK in endothelial cells.

Rosuvastatin suppresses the inflammatory responses through inhibition of c-Jun N-terminal kinase and Nuclear Factor-kappaB in endothelial cells.

Background: Rosuvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, has pleiotropic effects that are anti-inflammatory and antiatherothrombotic. It is important to understand the cardioprotective effects of rosuvastatin in order to optimize its additional advantages in the treatment and prevention of cardiovascular diseases. Methods: Human umbilical vein endothelial cells (HUVEC) were treated with tumor necrosis factor (TNF)-α (10 ng/mL) alone or with rosuvastatin (100 μM). The extent of inflammation was determined by U937 adhesion assay as well as analysis of the expression of intercellular adhesion molecule (ICAM)-1, monocyte chemoattractant protein (MCP)-1, interleukin (IL)-8, IL-6, cyclooxygenase (COX)-2, c-Jun N-terminal kinase (JNK), extracellular signal-regulated protein kinase (ERK), p38, and signal transducer and activator of transcription (STAT)-3. The activation of nuclear factor kappa B (NF-κB) was determined by Western blot. Results: Rosuvastatin decreased the extent of U937 adhesion to TNF-α-stimulated HUVEC. Rosuvastatin inhibited the expressions of ICAM-1, MCP-1, IL-8, IL-6, and COX-2 mRNA and protein levels. The activation of JNK and NF-κB was also blocked by rosuvastatin. The inhibitors of JNK, NF-κB, and STAT-3 produced a statistically significant decrease of the TNF-α induced U937 adhesion and IL-6 protein release. Conclusions: This study suggests that the anti-inflammatory activity of rosuvastatin is accompanied by the inhibition of JNK and NF-κB.

TNF-alpha enhances engraftment of mesenchymal stem cells into infarcted myocardium.

TNF-alpha released from ischemic heart after acute MI increases the production of other cytokines such as interleukin-1 (IL-1), interleukin-6 (IL-6) and adhesion molecules such as intercellular adhesion molecule-1 (ICAM-1). Activation of nuclear factor kappa B (NF-kappa B) by TNF-alpha , up-regulates the expression of molecules which are involved in inflammation and cell adhesion. For these reasons, we assessed the extent that treatment of MSC with tumor necrosis factor (TNF)-alpha modifies the characteristics of MSC, important to their engraftment in experimental myocardial infarct. Here, we show that pre-treatment of MSC prior to transplantation with tumor necrosis factor (TNF)-alpha increases adhesiveness, and migration of MSC in vitro and leads to increased expression of bone morphogenetic protein (BMP)-2 by MSC. Moreover, this treatment increases the rate of engraftment of MSC and improves recovery of cardiac function after myocardial infarction. These insights might provide better strategies for the treatment of myocardial infarction.

In vivo bioluminescence imaging of cord blood derived mesenchymal stem cell transplantation into rat myocardium

ObjectiveThe conventional method for the analysis of myocardial cell transplantation depends on postmortem histology. Here, we have sought to demonstrate the feasibility of a longitudinal monitoring of transplanted cell survival in living animals, accomplished with optical imaging techniques and pharmacological interventions.MethodsHuman cord blood (50 ml) was donated with parental consent. After getting cord blood derived mesenchymal stem cells (CBMSCs), cells were transfected (MOI = 100) overnight with adenovirus encoding firefly luciferase gene (Ad-CMV-Fluc). Our experimental Sprague-Dawley rats (n = 12) were given intramyocardial injections containing 1 × 106 CBMSCs, which had been made to express the firefly luciferase (Fluc) reporter gene. Optical bioluminescence imaging was then conducted using a cooled charged-coupled device (CCD) camera (Xenogen), beginning on the day after the transplantation (day 1). Groups of mice were intraperitoneally injected with cyclosporine (5 mg/kg) or tacrolimus (1 mg/kg), in an attempt to determine the degree to which cell survival had been prolonged, and these values were then compared with the cell survival values of the negative control group. The presence of transplanted CBMSCs on in vivo images confirmed by in situ hybridization for human specific Alu in the myocardium.ResultsCardiac bioluminescence signals were determined to be present for 6 days after transplantation: day 1 (97000 ± 9100 × 105 p/s/cm2/sr), day 3 (9600 ±1110 p/s/cm2/sr), and day 5 (3200 ± 550 p/s/cm2/sr). The six mice that received either cyclosporine or tacrolimus displayed cardiac bioluminescence signals for a period of 8 days after transplantation. We observed significant differences between the treated group and the non-treated group, beginning on day 3 (tacrolimus; 26500 ± 4340 p/s/cm2/sr, cyclosporine; 27200 ± 3340 p/s/cm2/sr, non-treated; 9630 ± 1180 p/s/cm2/sr, p < 0.01), and persisting until day 7 (tacrolimus; 12500 ± 2946 p/s/cm2/sr, cyclosporine; 7310 ±1258 p/s/cm2/sr, non-treated; 2460 ± 160 p/s/cm2/sr, p < 0.01). The human-derived CBMSCs were detected in the myocardium 3 days after transplantation by in situ hybridization.ConclusionsThe locations, magnitude, and survival duration of the CBMSCs were noninvasively monitored with a bioluminescence optical imaging system. We determined that optical molecular imaging expedites the fast throughput screening of pharmaceutical agents, allowing for the noninvasive tracking of cell survival within animals. In rat cardiac CBMSC transplant models, transient immunosuppressive treatment with tacrolimus or cyclosporine was shown to improve donor cell survival.

Promigratory activity of oxytocin on umbilical cord blood-derived mesenchymal stem cells.

Recent studies show that oxytocin has various effects on cellular behaviors. Oxytocin is reported to stimulate cardiomyogenesis of embryonic stem cells and endothelial cell proliferation. Mesenchymal stem cells (MSCs) are widely used for cardiac repair, and we elucidated the effect of oxytocin on umbilical cord derived-MSCs (UCB-MSCs). UCB-MSCs were pretreated with oxytocin (100 nM) and washed with saline prior to experiments. To evaluate their angiogenic potential and migration activity, tube formation assay and Boyden chamber assay were performed. For in vivo study, ischemia-reperfusion was induced in rats, and UCB-MSCs with or without oxytocin pretreatment were injected into the infarcted myocardium to evaluate the engraftment of injected cells. Histological and hemodynamic studies were performed. Oxytocin-treated UCB-MSCs showed a decrease in tube formation but a drastic increase in transwell migration activity. The transcription level of matrix metalloproteinase (MMP)-2 was increased in oxytocin-treated UCB-MSCs. Knock-down of MMP-2 by use of siRNA restored the tube formation, while reducing transmigration activity. In rats injected with oxytocin-treated UCB-MSCs, cardiac fibrosis and CD68 infiltration in the peri-infarct zone were reduced, whereas cell engraftment and connexin43 expression were greater than in rats injected with untreated UCB-MSCs. By contrast, angiogenesis did not differ significantly between the two groups. Cardiac contractility was higher in the group injected with oxytocin-treated UCB-MSCs than in the group injected with phosphate-buffered saline alone. Collectively, oxytocin is an effective priming reagent for stem cells for application to damaged heart tissue.

Enhanced angiogenesis mediated by vascular endothelial growth factor plasmid-loaded thermo-responsive amphiphilic polymer in a rat myocardial infarction model

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.

Protective role of 5-azacytidine on myocardial infarction is associated with modulation of macrophage phenotype and inhibition of fibrosis

We examined whether a shift in macrophage phenotype could be therapeutic for myocardial infarction (MI). The mouse macrophage cell line RAW264.7 was stimulated with peptidoglycan (PGN), with or without 5‐azacytidine (5AZ) treatment. MI was induced by ligation of the left anterior descending coronary artery in rats, and the rats were divided into two groups; a saline‐injection group and a 5AZ‐injection group (2.5 mg/kg/day, intraperitoneal injection). LV function was evaluated and immunohistochemical analyses were performed 2 weeks after MI. Cardiac fibrosis was induced by angiotensin II (AngII) infusion with or without 5AZ (5 mg/kg/day) in mice. Nitric oxide was produced by PGN, which was reduced by 77.87% after 5AZ treatment. Both induction of inducible nitric oxide synthase (iNOS) and iNOS promoter activity by PGN were inhibited by 5AZ. Ejection fraction (59.00 ± 8.03% versus 42.52 ± 2.58%), contractility (LV dP/dt‐max, 8299.76 ± 411.56 mmHg versus 6610.36 ± 282.37 mmHg) and relaxation indices (LV dP/dt‐min, −4661.37 ± 210.73 mmHg versus −4219.50 ± 162.98 mmHg) were improved after 5AZ administration. Cardiac fibrosis in the MI+5AZ was 8.14 ± 1.00%, compared with 14.93 ± 2.98% in the MI group (P < 0.05). Arginase‐1(+)CD68(+) macrophages with anti‐inflammatory phenotype were predominant in the infarct border zone of the MI+5AZ group, in comparison with the MI group. AngII‐induced cardiac fibrosis was also attenuated after 5AZ administration. In cardiac fibroblasts, pro‐fibrotic mediators and cell proliferation were increased by AngII, and these increases were attenuated after 5AZ treatment. 5AZ exerts its cardiac protective role through modulation of macrophages and cardiac fibroblasts.

Restoration of angiogenic capacity of diabetes-insulted mesenchymal stem cells by oxytocin

BackgroundAngiogenesis is the main therapeutic mechanism of cell therapy for cardiovascular diseases, but diabetes is reported to reduce the function and number of progenitor cells. Therefore, we studied the effect of streptozotocin-induced diabetes on the bone marrow-mesenchymal stem cell (MSC) function, and examined whether diabetes-impaired MSC could be rescued by pretreatment with oxytocin.ResultsMSCs were isolated and cultured from diabetic (DM) or non-diabetic (non-DM) rat, and proliferation rate was compared. DM-MSC was pretreated with oxytocin and compared with non-DM-MSC. Angiogenic capacity was estimated by tube formation and Matrigel plug assay, and therapeutic efficacy was studied in rat myocardial infarction (MI) model.The proliferation and angiogenic activity of DM-MSC were severely impaired but significantly improved by pretreatment with oxytocin. Krüppel-like factor 2 (KLF2), a critical angiogenic factor, was dramatically reduced in DM-MSC and significantly restored by oxytocin. In the Matrigel plug assay, vessel formation of DM-BMSCs was attenuated but was recovered by oxytocin. In rat MI model, DM-MSC injection did not ameliorate cardiac injury, whereas oxytocin-pretreated DM-MSC improved cardiac function and reduced fibrosis.ConclusionsOur results show that diabetes influenced MSC by reducing angiogenic capacity and therapeutic potential. We demonstrate the striking effect of oxytocin on stem cell dysfunction and suggest the use of oxytocin as a priming reagent in autologous stem cell therapy.

The novel role of mast cells in the microenvironment of acute myocardial infarction

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.

5-Azacytidine modulates interferon regulatory factor 1 in macrophages to exert a cardioprotective effect

Macrophages are actively involved in inflammatory responses during the progression of cardiac injury, including myocardial infarction (MI). A previous study showed that 5-azacytidine (5AZ), a DNA methylation inhibitor, can ameliorate cardiac injury by shifting macrophages toward an anti-inflammatory phenotype via iNOS inhibition. Here, we show that the beneficial effect of 5AZ is associated with sumoylation of interferon regulatory factor-1 (IRF1) in macrophages. IRF1 is a critical transcription factor for iNOS induction and is antagonized by IRF2. In the stimulated macrophages, IRF1 accumulated in the nucleus without degradation by 5AZ treatment. In animal study, 5AZ administration resulted in significant improvements in cardiac function and fibrosis. IRF1-expressing macrophages were more abundant in the 5AZ-treated MI group than in the PBS-treated MI group. Because sumoylated IRF1 is known to mimic IRF2, we examined the IRF1 sumoylation. Sumoylated IRF1 was resistant to degradation and significantly increased in the 5AZ-treated MI group. Collectively, 5AZ had a protective effect after MI by potentiation of IRF1 sumoylation and is suggested as a novel therapeutic intervention for cardiac repair.