Browsing by Author "Zhang, Donghui"

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    Tissue-engineered cardiac patch for advanced functional maturation of human ESC-derived cardiomyocytes.
    (Biomaterials, 2013-07) Zhang, Donghui; Shadrin, Ilya Y; Lam, Jason; Xian, Hai-Qian; Snodgrass, H Ralph; Bursac, Nenad
    Human embryonic stem cell-derived cardiomyocytes (hESC-CMs) provide a promising source for cell therapy and drug screening. Several high-yield protocols exist for hESC-CM production; however, methods to significantly advance hESC-CM maturation are still lacking. Building on our previous experience with mouse ESC-CMs, we investigated the effects of 3-dimensional (3D) tissue-engineered culture environment and cardiomyocyte purity on structural and functional maturation of hESC-CMs. 2D monolayer and 3D fibrin-based cardiac patch cultures were generated using dissociated cells from differentiated Hes2 embryoid bodies containing varying percentage (48-90%) of CD172a (SIRPA)-positive cardiomyocytes. hESC-CMs within the patch were aligned uniformly by locally controlling the direction of passive tension. Compared to hESC-CMs in age (2 weeks) and purity (48-65%) matched 2D monolayers, hESC-CMs in 3D patches exhibited significantly higher conduction velocities (CVs), longer sarcomeres (2.09 ± 0.02 vs. 1.77 ± 0.01 μm), and enhanced expression of genes involved in cardiac contractile function, including cTnT, αMHC, CASQ2 and SERCA2. The CVs in cardiac patches increased with cardiomyocyte purity, reaching 25.1 cm/s in patches constructed with 90% hESC-CMs. Maximum contractile force amplitudes and active stresses of cardiac patches averaged to 3.0 ± 1.1 mN and 11.8 ± 4.5 mN/mm(2), respectively. Moreover, contractile force per input cardiomyocyte averaged to 5.7 ± 1.1 nN/cell and showed a negative correlation with hESC-CM purity. Finally, patches exhibited significant positive inotropy with isoproterenol administration (1.7 ± 0.3-fold force increase, EC50 = 95.1 nm). These results demonstrate highly advanced levels of hESC-CM maturation after 2 weeks of 3D cardiac patch culture and carry important implications for future drug development and cell therapy studies.
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    WNT3 is a biomarker capable of predicting the definitive endoderm differentiation potential of hESCs.
    (Stem Cell Reports, 2013) Jiang, Wei; Zhang, Donghui; Bursac, Nenad; Zhang, Yi
    Generation of functional cells from human pluripotent stem cells (PSCs) through in vitro differentiation is a promising approach for drug screening and cell therapy. However, the observed large and unavoidable variation in the differentiation potential of different human embryonic stem cell (hESC)/induced PSC (iPSC) lines makes the selection of an appropriate cell line for the differentiation of a particular cell lineage difficult. Here, we report identification of WNT3 as a biomarker capable of predicting definitive endoderm (DE) differentiation potential of hESCs. We show that the mRNA level of WNT3 in hESCs correlates with their DE differentiation efficiency. In addition, manipulations of hESCs through WNT3 knockdown or overexpression can respectively inhibit or promote DE differentiation in a WNT3 level-dependent manner. Finally, analysis of several hESC lines based on their WNT3 expression levels allowed accurate prediction of their DE differentiation potential. Collectively, our study supports the notion that WNT3 can serve as a biomarker for predicting DE differentiation potential of hESCs.