The beneficial effects of stem cells in clinical applications to date have been modest, and studies have reported that poor engraftment might be an important reason. As a strategy to overcome such a hurdle, we developed the spheroid three dimensional (3D) bullet as a delivery method for human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) through the maintenance of cell-cell interactions without additional xenofactors, cytokines, or matrix. We made spheroid 3D-bullets from hUCB-MSCs at 24 hours' anchorage-deprived suspension culture. To investigate the in vivo therapeutic efficacy of 3D-bullets, we used rat myocardial infarction (MI) model. Transplantation of 3D-bullet was better than that of single cells from monolayer culture or from 3D-bullet in improving left ventricular (LV) contractility [LV ejection fraction (LVEF) or LV fractional shortening (LVFS)] and preventing pathologic LV dilatation [LV end-systolic diameter (LVESD) or LV end-diastolic diameter (LVEDD)] at 8 weeks. In the mechanism study of 3D-bullet formation, we found that calcium-dependent cell-cell interaction was essential and that E-cadherin is a key inducer mediating hUCB-MSC 3D-bullet formation among several calcium-dependent adhesion molecules which were nominated as candidates after cDNA array analysis. In more specific experiments with E-cadherin overexpression using adenoviral vector or with E-cadherin neutralization using blocking antibody, we found that E-cadherin regulates vascular endothelial growth factor (VEGF) secretion via extracellular signal-regulated kinase (ERK)/v-akt murine thymoma viral oncogene homolog1 (AKT) pathways. During formation of spheroid 3D-bullets, activation of E-cadherin in association with cell-cell interaction turns on ERK/AKT signaling pathway that are essential to proliferative and paracrine activity of MSCs leading to the enhanced therapeutic efficacy.

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Renal denervation is a promising new non-pharmacological treatment for resistant hypertension. However, there is a lack of data from Asian patients. The REQUIRE trial investigated the blood pressure-lowering efficacy of renal denervation in treated patients with resistant hypertension from Japan and South Korea. Adults with resistant hypertension (seated office blood pressure ≥150/90 mmHg and 24-hour ambulatory systolic blood pressure ≥140 mmHg) with suitable renal artery anatomy were randomized to ultrasound renal denervation or a sham procedure. The primary endpoint was change from baseline in 24-hour ambulatory systolic blood pressure at 3 months. A total of 143 patients were included (72 renal denervation, 71 sham control). Reduction from baseline in 24-hour ambulatory systolic blood pressure at 3 months was not significantly different between the renal denervation (−6.6 mmHg) and sham control (−6.5 mmHg) groups (difference: −0.1, 95% confidence interval −5.5, 5.3; p = 0.971). Reductions from baseline in home and office systolic blood pressure (differences: –1.8 mmHg [p = 0.488] and −2.0 mmHg [p = 0.511], respectively), and medication load, did not differ significantly between the two groups. The procedure-/device-related major adverse events was not seen. This study did not show a significant difference in ambulatory blood pressure reductions between renal denervation and a sham procedure in treated patients with resistant hypertension. Although blood pressure reduction after renal denervation was similar to other sham-controlled studies, the sham group in this study showed much greater reduction. This unexpected blood pressure reduction in the sham control group highlights study design issues that will be addressed in a new trial. Clinical trial registration NCT02918305 (http://www.clinicaltrials.gov).

SUMMARYIntroduction: High posttreatment platelet reactivity to clopidogrel (HPPR) is associated with major adverse cardiac events. However, the clinical predictors of HPPR in Asians have not been studied previously. Aims: We sought to determine clinical predictors of HPPR in Koreans. Results: We measured platelet reactivity with the VerifyNow P2Y12 assay in 1431 consecutive patients undergoing coronary angiography. We used the cut-off value of greater than 275 P2Y12 Reaction Unit (PRU) to define patients with HPPR. The clinical characteristics were compared between patients with HPPR (36.3%) and those without HPPR (63.7%). The mean age (65.4 ± 9.1 vs. 62.2 ± 9.7 years) was higher, hypertension (68.5% vs. 62.0%), diabetes mellitus (35.4% vs. 28.5%), chronic kidney disease (36.3% vs. 22.5%), renal replacement treatment (1.2% vs. 0.2%), and congestive heart failure (1.3% vs. 0.3%) were more common among patients with HPPR, while male gender (72.6% vs. 54.8%) and smoking (19.9% vs. 13.1%) were more common among non-HPPR patients. Mean glomerular filtration rate (63.5 ± 18.6 vs. 69.7 ± 16.1 mL/min/1.73 m 3 ) was lower and C-reactive protein (hs-CRP) (6.6 ± 20.5 mg/L vs. 4.2 ± 12.1 mg/L) level was higher among those with HPPR. Independent predictors of HPPR were female gender (OR 1.90, P ≤ 0.001), chronic kidney disease (OR 1.51, 0 = 0.004), diabetes mellitus (OR 1.35, P = 0.024), hs-CRP ≥ 2.0 mg/L (OR 1.31, P = 0.005), and age increase in decades (OR 1.21, P = 0.002), while smoking was negative risk factor (OR 0.63, P = 0.015). The number of risk factors was linearly associated with the risk of HPPR, with most patients having one or two predictors. Conclusion: In Korean population, independent clinical predictors of HPPR included diabetes mellitus, increased age, female gender, chronic kidney disease, and hs-CRP ≥ 2.0 mg/L, while cigarette smoking was associated with better responsiveness. Mean platelet reactivity and HPPR prevalence steadily increased with the number of clinical predictors.