Human dental pulp stem cells derived from cryopreserved dental pulp tissues of vital extracted teeth with disease demonstrate hepatic-like differentiation.

Reviewing the literature, hepatic differentiation of human dental pulp stem cells (hDPSCs) from cryopreserved dental pulp tissues of vital extracted teeth with disease has not been studied. This study is aimed to evaluate the hypothesis that hDPSCs from cryopreserved dental pulp tissues of vital extracted teeth with disease could possess potential hepatic differentiation. Forty vital extracted teeth with disease recruited for hDPSCs isolation, stem cell characterization and hepatic differentiation were randomly and equally divided into group A (liquid nitrogen-stored dental pulp tissues) and group B (freshly derived dental pulp tissues). Samples of hDPSCs isolated from groups A and B but without hepatic growth factors formed negative controls. A well-differentiated hepatocellular carcinoma cell line was employed as a positive control. All the isolated hDPSCs from groups A and B showed hepatic-like differentiation with morphological change from a spindle-shaped to a polygonal shape and normal karyotype. Differentiated hDPSCs and the positive control expressed hepatic metabolic function genes and liver-specific genes. Glycogen storage of differentiated hDPSCs was noted from day 7 of differentiation-medium culture. Positive immunofluorescence staining of low-density lipoprotein and albumin was observed from day 14 of differentiation-medium culture; urea production in the medium was noted from week 6. No hepatic differentiation was observed for any of the samples of the negative controls. We not only demonstrated the feasibility of hepatic-like differentiation of hDPSCs from cryopreserved dental pulp tissues of vital extracted teeth with disease but also indicated that the differentiated cells possessed normal karyotype and were functionally close to normal hepatic-like cells. Copyright © 2013 John Wiley & Sons, Ltd.

Reversal of cellular phenotypes in neural cells derived from Huntington's disease monkey-induced pluripotent stem cells.

Huntington's disease (HD) is a dominant neurodegenerative disorder caused by the expansion of glutamine residues in the N-terminal region of the huntingtin (HTT) protein. The disease results in progressive neuronal loss, leading to motor, cognitive, and psychiatric impairment. Here, we report the establishment of neural progenitor cell (NPC) lines derived from induced pluripotent stem cells (iPSCs) of transgenic HD monkeys. Upon differentiation to neurons, HD neural cells develop cellular features of HD, including the formation of nuclear inclusions and oligomeric mutant HTT (mHTT) aggregates, as well as increased apoptosis. These phenotypes are rescued by genetic suppression of HTT and pharmacological treatment, demonstrating the ability of our HD cell model to respond to therapeutic treatment. The development and reversal of HD-associated phenotypes in neural cells from HD monkeys provides a unique nonhuman primate (NHP) model for exploring HD pathogenesis and evaluating therapeutics that could be assessed further in HD monkeys.

Characterization of dental pulp stem/stromal cells of Huntington monkey tooth germs.

BACKGROUND: Dental pulp stem/stromal cells (DPSCs) are categorized as adult stem cells (ASCs) that retain multipotent differentiation capabilities. DPSCs can be isolated from individuals at any age and are considered to be true personal stem cells, making DPSCs one of the potential options for stem cell therapy. However, the properties of DPSCs from individuals with an inherited genetic disorder, such as Huntington's disease (HD), have not been fully investigated. RESULTS: To examine if mutant huntingtin (htt) protein impacts DPSC properties, we have established DPSCs from tooth germ of transgenic monkeys that expressed both mutant htt and green fluorescent protein (GFP) genes (rHD/G-DPSCs), and from a monkey that expressed only the GFP gene (rG-DPSCs), which served as a control. Although mutant htt and oligomeric htt aggregates were overtly present in rHD/G-DPSCs, all rHD/G-DPSCs and rG-DPSCs shared similar characteristics, including self-renewal, multipotent differentiation capabilities, expression of stemness and differentiation markers, and cell surface antigen profile. CONCLUSIONS: Our results suggest that DPSCs from Huntington monkeys retain ASC properties. Thus DPSCs derived from individuals with genetic disorders such as HD could be a potential source of personal stem cells for therapeutic purposes.