Rictor/mTORC2 involves mitochondrial function in ES cells derived cardiomyocytes via mitochondrial Connexin 43.

Rictor is a key component of the mammalian target of rapamycin complex 2 (mTORC2) and is required for Akt phosphorylation (Ser473). Our previous study shows that knockdown of Rictor prevents cardiomyocyte differentiation from mouse embryonic stem (ES) cells and induces abnormal electrophysiology of ES cell-derived cardiomyocytes (ESC-CMs). Besides, knockdown of Rictor causes down-expression of connexin 43 (Cx43), the predominant gap junction protein, that is located in both the sarcolemma and mitochondria in cardiomyocytes.

[Rictor regulates mitochondrial calcium signaling in mouse embryo stem cell-derived cardiomyocytes].

Objective: To explore the expression, localization and regulatory effect on mitochondrial calcium signaling of Rictor in embryonic stem cell-derived cardiomyocytes (ESC-CMs).

Methods: Classical embryonic stem cell cardiomyogenesis model was used for differentiation of mouse embryonic stem cells into cardiomyocytes. The location of Rictor in ESC-CMs was investigated by immunofluorescence and Western blot.

Mitochondrial toxicity of perfluorooctane sulfonate in mouse embryonic stem cell-derived cardiomyocytes.

Perfluorooctane sulfonate (PFOS) is a persistent organic contaminant that may cause cardiotoxicity in animals and humans. However, little is known about the underlying mechanism by which it affects the organelle toxicity in cardiomyocytes during the cardiogenesis. Our previous proteomic study showed that differences of protein expression mainly existed in mitochondria of cardiomyocytes differentiated from embryonic stem (ES) cells after exposure to PFOS.

mTORC1 and mTORC2 play different roles in regulating cardiomyocyte differentiation from embryonic stem cells.

Mammalian target of rapamycin (mTOR) is a serine/threonine kinase and functions through two distinct complexes, mTOR complex 1 (mTORC1) and complex 2 (mTORC2), with their key components Raptor and Rictor, to play crucial roles in cellular survival and growth. However, the roles of mTORC1 and mTORC2 in regulating cardiomyocyte differentiation from mouse embryonic stem (mES) cells are not clear. In this study, we performed Raptor or Rictor knockdown experiments to investigate the roles of mTORC1 and mTORC2 in cardiomyocyte differentiation.

Involvement of Rictor/mTORC2 in cardiomyocyte differentiation of mouse embryonic stem cells .

Rictor is a key regulatory/structural subunit of the mammalian target of rapamycin complex 2 (mTORC2) and is required for phosphorylation of Akt at serine 473. It plays an important role in cell survival, actin cytoskeleton organization and other processes in embryogenesis. However, the role of Rictor/mTORC2 in the embryonic cardiac differentiation has been uncovered.