Assessment of the potential of the human mesenchymal stem cells for cardiac tissue engineering

  • Dr Azar Asgari, O’Brian Institute, Fitzroy, VIC, Australia
  • Mr YuSuk Chio, O’Brian Institute, Fitzroy, VIC, Australia
  • Dr Takashi Ajiki, O’Brian Institute, Fitzroy, VIC, Australia
  • Dr Nicholas Rufaut, Department of Dermatology, St Vincent’s Hospital, VIC, Australia
  • Dr Rondey Dilley, O’Brian Institute, Fitzroy, VIC, Australia
  • Dr Robert Kapsa, Australia
  • Prof Rodney Sinclair, Department of Dermatology, St Vincent’s Hospital, VIC, Australia

The adult hair follicle is a rich source of multi-potent stem cells. Cells from the follicle mesenchyme, the dermal papilla and dermal sheath, can reconstitute multiple lineages of the haematopoietic system in lethally irradiated mice. They can also differentiate towards the adipogenic, osteogenic, and chondrogenic lineages in vitro, similar to bone marrow mesenchymal stem cells. We have previously shown that bovine papilla cells undergo skeletal muscle differentiation in vitro. We are currently studying the ability of dermal stem cells from human follicles to undergo cardiac muscle differentiation.

Dermal cells from human hair follicles were cultured to passage 3-6 for in vivo and in vitro experiments. Adipose differentiation was tested with inductive culture medium. Skeletal muscle differentiation was tested by co-culture with differentiating myoblasts. Cardiac differentiation in vitro was tested by co-culture with neonatal rat cardiomyocytes; expression of cardiac differentiation markers was evaluated by PCR. Cardiac differentiation in vivo was tested by co-implantation of Di-I labelled cells with cardiomyocytes in a vascularised tissue chamber implanted in a nude rat.

Follicle dermal cells underwent both adipose and skeletal muscle differentiation, confirming their multipotency. In co-cultures with cardiomyocytes, mRNA expression of cardiac actin and troponin T increased after one and two weeks by 10 and 20 times respectively. In the in vivo experiments, Di-I labelled cells were not seen in the cardiac tissue that formed in the tissue chamber. However a few labelled cells were associated with blood vessels and adipose tissue.

Our in vitro experiments suggest follicle dermal cells from humans have some potential for both skeletal and cardiac muscle differentiation. We are currently further evaluating the fate of these cells in the in vivo cardiac differentiation model. Because the Di-I label is lost with cell proliferation, we will use immune-staining for human-specific nuclear antigens to trace progeny of the implanted cells.