Application of human embryonic stem cells (hESCs) to stem-cell therapy is not feasible because of the risk of tumorigenicity and rejection. In contrast, human mesenchymal stem cells (hMSCs) are free from the risk of tumorigenicity and also have immune privilege. However, hMSCs obtained from adults have infinite variety in terms of the biological characteristics and functionality. We report here a new derivation method of hMSCs from hESCs. The derivation of hMSCs from three different hESC lines (SNUhES3, CHA3-hESC, and H9) was performed by embryoid bodies formation and subsequent culture with stage-different media without using inductive xenogenic feeder and mechanical selection procedure. The derived cells were morphologically similar to the unique fingerprint-like pattern of hMSCs and grew stably for at least 35 passages in vitro. These cells had hMSCs-like immunophenotypes: negative for CD34 and CD45; positive for CD29, CD44, CD73, CD90, and CD105. They could be differentiated into multiple lineages including osteocytes, chondrocytes, adipocytes, and myocytes. They maintained normal karyotype during the long-term cultivation and did not show tumorigenicity when transplanted into the immunodeficient mice. In conclusion, the new embryoid body–based derivation method of hMSCs from hESCs is simple, safe, and reproducible in three different hESC lines. We expect that this method will provide a more effective and powerful tool to derive hMSCs from various hESC lines.

Stem cell transplantation in acute myocardial infarction (AMI) has emerged as a promising therapeutic option. We evaluated the impact of AMI on mesenchymal stem cell (MSC) differentiation into cardiomyocyte lineage. Cord blood-derived human MSCs were exposed to in vitro conditions simulating in vivo environments of the beating heart with acute ischemia, as follows: (a) myocardial proteins or serum obtained from sham-operated rats, and (b) myocardial proteins or serum from AMI rats, with or without application of oscillating pressure. Expression of cardiac-specific markers on MSCs was greatly induced by the infarcted myocardial proteins, compared with the normal proteins. It was also induced by application of oscillating pressure to MSCs. Treatment of MSCs with infarcted myocardial proteins and oscillating pressure greatly augmented expression of cardiac-specific genes. Such expression was blocked by inhibitor of transforming growth factor β1 (TGF-β1) or bone morphogenetic protein-2 (BMP-2). In vitro cellular and electrophysiologic experiments showed that these differentiated MSCs expressing cardiomyocyte-specific markers were able to make a coupling with cardiomyocytes but not to selfbeat. The pathophysiologic significance of in vitro results was confirmed using the rat AMI model. The protein amount of TGF-β1 and BMP-2 in myocardium of AMI was significantly higher than that in normal myocardium. When MSCs were transplanted to the heart and analyzed 8 weeks later, they expressed cardiomyocyte-specific markers, leading to improved cardiac function. These in vitro and in vivo results suggest that infarct-related biological and physical factors in AMI induce commitment of MSCs to cardiomyocyte-like cells through TGF-β/BMP-2 pathways. Disclosure of potential conflicts of interest is found at the end of this article.

Korean Circulation Journal 대한심장학회지 순환기 Shin DH, et al. Korean Circ J. 2019 Dec;49(12):1136-1151. https://doi.org/10.4070/kcj.2018.0413

To demonstrate the association of the serum creatinine/serum cystatin C ratio (sarcopenia index, SI) with clinical outcomes including cardiovascular and bleeding risk in older patients who underwent percutaneous coronary intervention (PCI), we analyzed a multicenter nation-wide pooled registry. A total of 1086 older patients (65 years or older) who underwent PCI with second-generation drug-eluting stents (DES) were enrolled. The total population was divided into quartiles according to the SI, stratified by sex. The primary clinical outcomes were major adverse cardiovascular events (MACE, all-cause death, myocardial infarction and target lesion revascularization) and thrombolysis in myocardial infarction major and minor bleeding during a 3-year follow-up period. In the total population, MACE occurred within 3 years in 154 (14.2%) patients. The lowest SI quartile group (Q1) had a significantly higher 3-year MACE rate (Q1 vs. Q2–4; 23.1% vs. 11.2%, p < 0.001), while bleeding event rates were similar between the groups (Q1 vs. Q2–4; 2.6% vs. 2.2%, p = 0.656). The Cox proportional hazard model showed that lower SI is an independent predictor for MACE events (HR 2.23, 95% CI 1.62–3.07, p < 0.001). The SI, a surrogate for the degree of muscle mass, is associated with cardiovascular and non-cardiovascular death, but not with bleeding in older patients who underwent PCI.

Paravalvular leak (PVL) is an important complication of transcatheter aortic valve implantation (TAVI) and is associated with poor prognosis. We aimed to identify the risk factors for PVL after TAVI including patient (calcium amount or location), device (leakage-proof or not), and procedural (oversizing index (OI)) factors. The primary outcome was mild or greater PVL at 1-month follow-up echocardiography. Overall, 238 patients who underwent TAVI using eight types of valves (Edwards Sapien, Sapien XT, Sapien 3, CoreValve, Evolut R, Evolut PRO, Lotus, and Lotus Edge) were included. The incidence of significant PVL (≥mild PVL) was 24.4%. Although patient factors (calcification of valve) were not predictors of PVL, valve without leakage-proof function (Edwards Sapien, Sapien XT, and CoreValve) was a significant predictor of PVL (adjusted odds ratio, 3.194, 95% CI, 1.620–6.299). Furthermore, OI has a significant protective role against PVL (PVL increased by 45% when OI decreased by 5%). The best cutoff value of OI to predict the absence of PVL was ≥17.6% for the Evolut system and ≥10.2% for the Sapien system. The predictors of PVL after TAVI included factors from the device (valve without leakage-proof function) and procedure (under-sizing). In patients with a high risk of PVL, the procedure should be optimized using valves with leakage-proof function and adequate OI.