Вывод из высокоочищенных кардиомиоцитов из человеческих индуцированных плюрипотентных стволовых клеток с использованием малой молекулы-модулированный Дифференциация и последующих глюкозы Голод

Primary human cardiomyocytes are difficult to obtain because of the requirement for invasive cardiac biopsies, difficulty in dissociating to single cells, and because of poor long-term cell survival in culture. Given this lack of primary human cardiomyocytes, patient-specific human induced pluripotent stem cell-derived cardiomyocyte (hiPSC-CM) technology has been regarded as a powerful alternative cardiomyocyte source for basic research as well as clinical and translational applications such as disease modeling and drug discovery¹. Early efforts in differentiating pluripotent stem cells into cardiomyocytes employed differentiation protocols using embryoid bodies (EBs), but this method is inefficient in producing cardiomyocytes because often less than 25% of cells in an EB are beating cardiomyocytes^2,3. Comparatively, a monolayer-based differentiation protocol using the cytokines activin A and BMP4 displayed a higher efficiency than EBs, but this protocol is still relatively inefficient, requires expensive growth factors, and only functions in a limited number of human pluripotent stem cell lines⁴. Recently, a highly efficient, hiPSC monolayer-based cardiomyocyte differentiation protocol was developed by modulating Wnt/β-Catenin signaling⁵. These hiPSC-CMs express cardiac troponin T and alpha actinin, two sarcomeric proteins that are standard markers of cardiomyocytes⁶. The protocol describe here is an adaptation of this small molecule-based, feeder cell-free, monolayer differentiation method^5,7. We are able to obtain beating cardiomyocytes from hiPSCs after 7-10 days (Figure 1). However, following a cardiomyocyte differentiation resulting in 50% beating cells, immunostaining consistently shows the existence of a population of non-cardiomyocytes that are negative for cardiomyocyte-specific markers such as cardiac-specific troponin T and alpha-actinin. To further purify cardiomyocytes and eliminate non-cardiomyocytes, heterogeneous differentiated cell populations were subjected to glucose starvation by treating them with an extremely low glucose culture medium for multiple days (Figure 2). This treatment selectively eliminates non-cardiomyocytes due to the ability of cardiomyocytes, but not non-cardiomyocytes, to metabolize lactate as the primary energy source in order to survive in a low glucose environment⁸. After this purification step, a 40% increase in the ratio of cardiomyocytes to non-cardiomyocytes is observed, (Figure 3, Figure 4) and these cells can be used for downstream gene expression analysis, disease modeling, and drug screening assays.