Human Amniocytes Are Receptive to Chemically Induced Reprogramming to Pluripotency.

Restoring pluripotency using chemical compounds alone would be a major step forward in developing clinical-grade pluripotent stem cells, but this has not yet been reported in human cells. We previously demonstrated that VPA_AFS cells, human amniocytes cultivated with valproic acid (VPA) acquired functional pluripotency while remaining distinct from human embryonic stem cells (hESCs), questioning the relationship between the modulation of cell fate and molecular regulation of the pluripotency network. Here, we used single-cell analysis and functional assays to reveal that VPA treatment resulted in a homogeneous population of self-renewing non-transformed cells that fulfill the hallmarks of pluripotency, i.

Counteracting bone fragility with human amniotic mesenchymal stem cells.

The impaired maturation of bone-forming osteoblasts results in reduced bone formation and subsequent bone weakening, which leads to a number of conditions such as osteogenesis imperfecta (OI). Transplantation of human fetal mesenchymal stem cells has been proposed as skeletal anabolic therapy to enhance bone formation, but the mechanisms underlying the contribution of the donor cells to bone health are poorly understood and require further elucidation. Here, we show that intraperitoneal injection of human amniotic mesenchymal stem cells (AFSCs) into a mouse model of OI (oim mice) reduced fracture susceptibility, increased bone strength, improved bone quality and micro-architecture, normalised bone remodelling and reduced TNFα and TGFβ sigalling.

Human Chorionic Stem Cells: Podocyte Differentiation and Potential for the Treatment of Alport Syndrome.

Alport syndrome (AS) is a hereditary glomerulopathy caused by a mutation in type IV collagen genes, which disrupts glomerular basement membrane, leading to progressive glomerulosclerosis and end-stage renal failure. There is at present no cure for AS, and cell-based therapies offer promise to improve renal function. In this study, we found that human first trimester fetal chorionic stem cells (CSC) are able to migrate to glomeruli and differentiate down the podocyte lineage in vitro and in vivo.

Molecular signature of human amniotic fluid stem cells during fetal development.

Mid-gestation c-KIT(+) amniotic fluid stem cells (AFSC) have an intermediate phenotype between embryonic and adult stem cells and are easy to reprogram to pluripotency. We previously showed that 1st trimester AFSC can be reprogrammed to functional pluripotency in a transgene-free approach. Despite both parental populations sharing a common phenotype, expressing CD29, CD44, CD73, CD90, CD105, SSEA4 and OCT4, 2nd trimester AFSC, contrary to 1st trimester cells, do not express NANOG, SSEA3, TRA-1-60 and TRA-1-81, and have slower growth kinetics.

Upregulating CXCR4 in human fetal mesenchymal stem cells enhances engraftment and bone mechanics in a mouse model of osteogenesis imperfecta.

Stem cells have considerable potential to repair damaged organs and tissues. We previously showed that prenatal transplantation of human first trimester fetal blood mesenchymal stem cells (hfMSCs) in a mouse model of osteogenesis imperfecta (oim mice) led to a phenotypic improvement, with a marked decrease in fracture rate. Donor cells differentiated into mature osteoblasts, producing bone proteins and minerals, including collagen type Iα2, which is absent in nontransplanted mice.

Ontological differences in first compared to third trimester human fetal placental chorionic stem cells.

Human mesenchymal stromal/stem cells (MSC) isolated from fetal tissues hold promise for use in tissue engineering applications and cell-based therapies, but their collection is restricted ethically and technically. In contrast, the placenta is a potential source of readily-obtainable stem cells throughout pregnancy. In fetal tissues, early gestational stem cells are known to have advantageous characteristics over neonatal and adult stem cells.

Valproic acid confers functional pluripotency to human amniotic fluid stem cells in a transgene-free approach.

Induced pluripotent stem cells (iPSCs) with potential for therapeutic applications can be derived from somatic cells via ectopic expression of a set of limited and defined transcription factors. However, due to risks of random integration of the reprogramming transgenes into the host genome, the low efficiency of the process, and the potential risk of virally induced tumorigenicity, alternative methods have been developed to generate pluripotent cells using nonintegrating systems, albeit with limited success. Here, we show that c-KIT+ human first-trimester amniotic fluid stem cells (AFSCs) can be fully reprogrammed to pluripotency without ectopic factors, by culture on Matrigel in human embryonic stem cell (hESC) medium supplemented with the histone deacetylase inhibitor (HDACi) valproic acid (VPA).

The effects of culture on genomic imprinting profiles in human embryonic and fetal mesenchymal stem cells.

Human embryonic stem (hES) cells and fetal mesenchymal stem cells (fMSC) offer great potential for regenerative therapy strategies. It is therefore important to characterise the properties of these cells in vitro. One major way the environment impacts on cellular physiology is through changes to epigenetic mechanisms.

Biological characteristics of stem cells from foetal, cord blood and extraembryonic tissues.

Foetal stem cells (FSCs) can be isolated during gestation from many different tissues such as blood, liver and bone marrow as well as from a variety of extraembryonic tissues such as amniotic fluid and placenta. Strong evidence suggests that these cells differ on many biological aspects such as growth kinetics, morphology, immunophenotype, differentiation potential and engraftment capacity in vivo. Despite these differences, FSCs appear to be more primitive and have greater multi-potentiality than their adult counterparts.