Simple autogeneic feeder cell preparation for pluripotent stem cells

The use of human amniotic fluid mesenchymal stem cells as the feeder layer to establish human embryonic stem cell lines

Human embryonic stem cells (hESCs) are pluripotent cells that have the potential to differentiate into the three germ layers and possibly all tissues of the human body. To fulfil the clinical potentials for cell-based therapy, banks of hESC lines that express different combinations of the major histocompatibility genes should be established, preferably without exposing such cells to animal cells and proteins. In this study, we tested human amniotic fluid mesenchymal stem cells (AFMSCs) as feeder cells to support the growth of hESCs. Our results indicated that mitomycin-treated AFMSCs were able to support the newly established hESC lines CGLK-1 and CGLK-2. The hESC colonies cultured on AFMSCs expressed alkaline phosphatase (ALK-P), SSEA-4, TRA-1-60, TRA-1-81, Oct-4, Nanog and Sox-2, which are markers for undifferentiated hESCs. Chromosomal analyses of both hESC lines, CGLK-1 and CGLK-2, which were cultured on AFMSC feeders for 22 and 14 passages, respectively, were confirmed to be normal karyotypes (46, XX). The ability of AFMSCs as feeder cells to maintain the undifferentiated growth and pluripotency of hESCs was confirmed by in vivo formation of teratomas derived on AFMSC hESCs in severe combined immune-compromised mice. The use of AFMSCs for feeder cells to culture hESCs has several advantages, in that AFMSCs are not tumourigenic and can be expanded extensively with a short doubling time.

A novel xenogeneic co-culture system to examine neuronal differentiation capability of various adult human stem cells

Background

Targeted differentiation of stem cells is mainly achieved by the sequential administration of defined growth factors and cytokines, although these approaches are quite artificial, cost-intensive and time-consuming. We now present a simple xenogeneic rat brain co-culture system which supports neuronal differentiation of adult human stem cells under more in vivo-like conditions.

Methods and Findings

This system was applied to well-characterized stem cell populations isolated from human skin, parotid gland and pancreas. In addition to general multi-lineage differentiation potential, these cells tend to differentiate spontaneously into neuronal cell types in vitro and are thus ideal candidates for the introduced co-culture system. Consequently, after two days of co-culture up to 12% of the cells showed neuronal morphology and expressed corresponding markers on the mRNA and protein level. Additionally, growth factors with the ability to induce neuronal differentiation in stem cells could be found in the media supernatants of the co-cultures.

Conclusions

The co-culture system described here is suitable for testing neuronal differentiation capability of numerous types of stem cells. Especially in the case of human cells, it may be of clinical relevance for future cell-based therapeutic applications.

Human feeder cell line for derivation and culture of hESc/hiPSc

We have generated a human feeder cell line from early second trimester Placental Stromal Fibroblasts (ihPSF) stably over-expressing the polycomb protein BMI-1. These feeder cells retain the ability to maintain human Embryonic Stem cells (hESc) over long-term culture whereas hTERT or BMI-1/hTERT immortalised feeder cell lines do not. ihPSFs were able to support the derivation of a new hESc line in near xenofree (free of non-human animal components) conditions and support continued culture of newly derived hESc and human induced Pluripotent Stem (hiPS) cell lines in complete xenofree conditions necessary for clinical use.

Strategies for ensuring that regenerative cardiomyocytes function properly and in cooperation with the host myocardium

In developed countries, in which people have nutrient-rich diets, convenient environments, and access to numerous medications, the disease paradigm has changed. Nowadays, heart failure is one of the major causes of death. In spite of this, the therapeutic efficacies of medications are generally unsatisfactory. Although whole heart transplantation is ideal for younger patients with heart failure, many patients are deemed to be unsuitable for this type of surgery due to complications and/or age. The need for therapeutic alternatives to heart transplantation is great. Regenerative therapy is a strong option. For this purpose, several cell sources have been investigated, including intrinsic adult stem or progenitor cells and extrinsic pluripotent stem cells. Most intrinsic stem cells seem to contribute to a regenerative environment via paracrine factors and/or angiogenesis, whereas extrinsic pluripotent stem cells are unlimited sources of cardiomyocytes. In this review, we summarize the various strategies for using regenerative cardiomyocytes including our recent progressions: non-genetic approaches for the purification of cardiomyocytes and efficient transplantation. We expect that use of intrinsic and extrinsic stem cells in combination will enhance therapeutic effectiveness.