Cells derived from human umbilical cord blood support the long-term growth of undifferentiated human embryonic stem cells

Hair follicle-derived mesenchymal cells support undifferentiated growth of embryonic stem cells

The aim of the present study was to investigate whether feeder layers composed of human hair follicle-derived mesenchymal stem cells (hHFDCs) are able to support human embryonic stem cells (hESCs). hHFDCs and mouse embryonic fibroblasts (MEFs) were isolated and cultured in Dulbecco's modified Eagle's medium (DMEM)/F-12 and low-glucose DMEM, respectively. hHFDCs were passaged three times and subsequently characterized. hHFDCs and MEFs were mitotically inactivated with mitomycin C for 3 h prior to co-culture with H9-hESCs. hESCs were initially established on a mouse feeder layer, subsequently transferred onto a human feeder layer and split every 5 days. Cell morphology, expression of specific 'undifferentiation' markers and growth factors, and the differentiation capacity of hESCs grown on the hHFDC feeder layer were analyzed. hHFDCs are adherent to plastic, possess the classic mesenchymal stem cell phenotype [they express cluster of differentiation (CD)90, CD73 and CD105] and are able to differentiate into adipocytes, chondroblasts and osteocytes, indicating that these cells are multipotent. Population-doubling time analysis revealed that hHFDCs rapidly proliferate over 34.5 h. As a feeder layer, hHFDC behaved similarly to MEF in maintaining the morphology of hESCs. The results of alkaline phosphatase activity, reverse transcription-quantitative polymerase chain reaction analysis of the expression of pluripotency transcription factors [octamer-binding transcription factor 4 (Oct4), Nanog and sex determining region Y-box 2], and immunofluorescence assays of markers (stage-specific embryonic antigen-4 and Oct4) in hESCs co-cultured over hHFDC, indicated that the undifferentiated state of hESCs was preserved. No change in the level of growth factor transcripts (bone morphogenetic protein 4, fibroblast growth factor-2, vascular endothelial growth factor, Pigment epithelium-derived factor and transforming growth factor-β1) was detected for either feeder layer prior to or following inactivation. Similar phenotypes of embryoid body formation, size and morphology were observed in the hHFDC and MEF feeders. In conclusion, hHFDC maintained hESCs in an undifferentiated state comparable to MEF in standard conditions, which may be an important finding regarding the establishment of stem cell-based translational applications.

Urine--a waste or the future of regenerative medicine?

In recent years, urine has emerged as a source of urine cells. Two different types of cells can be isolated from urine: urine derived stem cells (USCs) and renal tubular cells called urine cells (UCs). USCs have great differentiation properties and can be potentially used in genitourinary tract regeneration. Within this paper, we attempt to demonstrate that such as easily accessible source of cells, collected during completely non-invasive procedures, can be better utilized. Cells derived from urine can be isolated, stored, and used for the creation of urine stem cell banks. In the future, urine holds great potential to become a main source of cells for tissue engineering and regenerative medicine.

Human Menstrual Blood-Derived Mesenchymal Cells as New Human Feeder Layer System for Human Embryonic Stem Cells

Human embryonic stem cells (hESCs) in general require coculture with feeder layers in order to remain undifferentiated. However, the use of animal-derived feeder layers is incompatible with the clinical setting. The objective of this work was to investigate whether human menstrual blood-derived mesenchymal cells (MBMCs) can substitute mouse embryonic fibroblasts (MEFs) as a feeder layer for H9-hESCs. Both feeder cell types were isolated and cultured in DMEM F-12 and high glucose DMEM, respectively. After three passages, they were inactivated with mitomycin C. To test MBMC feeder layer capacity, hESCs were grown over MBMCs and MEFs under standard conditions. hESC growth, proliferation, survival, and maintenance of the undifferentiated state were evaluated. hESCs grown over MBMCs preserved their undifferentiated state presenting standard morphology, expressing alkaline phosphatase, transcription factors OCT3/4, SOX2, and NANOG by RT-PCR and SSEA-4 and OCT3/4 by immunofluorescence assays. It is noteworthy that none of the feeder cells expressed these proteins. The average colony size of the hESCs on MBMCs was higher when compared to MEFs (p < 0.05; mean ± SD, n = 3). Growth factor analysis revealed amplification of the transcripts for FGF-2, BMP4, TGF-β, VEGF, and PEDF by RT-PCR in MBMCs and MEFs before and after inactivation. Furthermore, similar embryoid body formation, size, and morphology were observed in both feeder layers. In addition, EBs expressed marker genes for the three germ layers cultured on both feeder cells. In conclusion, MBMCs are able to maintain hESCs in an undifferentiated state with comparable efficiency to MEFs. Therefore, MBMCs are a suitable alternative to animal-derived feeder layers for growing hESCs.

Tissue engineering and ureter regeneration: is it possible?

Large ureter damages are difficult to reconstruct. Current techniques are complicated, difficult to perform, and often associated with failures. The ureter has never been regenerated thus far. Therefore the use of tissue engineering techniques for ureter reconstruction and regeneration seems to be a promising way to resolve these problems. For proper ureter regeneration the following problems must be considered: the physiological aspects of the tissue, the type and shape of the scaffold, the type of cells, and the specific environment (urine). 
This review presents tissue engineering achievements in the field of ureter regeneration focusing on the scaffold, the cells, and ureter healing.

Human fetal trophonema matrix and uterine endometrium support better human embryonic stem cell growth and neural differentiation than mouse embryonic fibroblasts

The concerns over xenogeneic pathogens and immunogenic molecules derived from mouse embryonic fibroblasts (MEFs) trigger the development of human-derived feeder layers for human embryonic stem cell (hESC) maintenance. It is essential to evaluate the capability of these human feeder layers to retain the stemness and pluripotency of hESCs. In the present study, two Chinese hESC lines, SDU-hESCm-1 and SDU-hESCm-2, were continuously cultured on human adult uterine endometrial cells (hUEC), human fetal trophonema matrix cells (hFTMC), and MEFs for at least two month (up to 10 passages). A side-by-side comparison of the abilities to support: (1) self-renewal of the hESCs, (2) expression of undifferentiated markers, and (3) neural differentiation, was made between the human and mouse feeder layers. We demonstrated that the hESCs maintained on hUEC and hFTMC exhibited significantly higher growth rates and generated higher levels of DNA content than those on MEFs. Under neural differentiation-promoting conditions, greater neural differentiation was found in the hESCs maintained on human than on mouse feeder layers. These results suggest that human feeder layers derived from hUECs and hFTMCs are more efficient in supporting a long-term growth and neural differentiation of hESCs than MEFs.

Proliferation and pluripotency of human embryonic stem cells maintained on type I collagen

Human embryonic stem cells (hESC) require a balance of growth factors and signaling molecules to proliferate and retain pluripotency. Conditioned medium (CM) from a human embryonic germ-cell-derived cell culture, SDEC, was observed to support the growth of hESC on type I collagen (COL I) and on Matrigel (MAT) biomatricies. After 1 month, the population doubling of hESC grown in SDEC CM on COL I was equivalent to that of hESC grown in mouse embryonic fibroblast (MEF) CM on MAT. hESC grown in SDEC CM on COL I expressed OCT4, NANOG, SSEA-4, alkaline phosphatase (AP), and TRA-1-60; retained a normal karyotype; and were capable of forming teratomas. DNA microarray analysis was used to compare the transcriptional profiles of SDEC and the less supportive WI38 and Detroit 551 human cell lines. The mRNA level of secreted frizzled-related protein (sFRP-1), a known antagonist of the WNT/β-catenin signaling pathway, was significantly reduced in SDEC as compared with the other 2 cell lines, whereas the mRNA levels of prostaglandin-endoperoxide synthase 2 (PTGS2 or COX-2) and prostaglandin I₂ synthase (PGIS), two prostaglandin biosynthesis genes, were significantly increased in SDEC. The level of sFRP-1 protein was significantly reduced, and levels of 2 prostaglandins that are downstream products of PTGS2 and PGIS, prostaglandin E₂ and 6-keto-prostaglandin F(1α), were significantly elevated in SDEC CM compared with WI38, Detroit 551, and MEF CM. Further, addition of purified sFRP-1 to SDEC CM reduced the proliferation of hESC grown on COL I as well as MAT in a dose-dependent manner.

Cell-based therapies for Parkinson's disease: past, present, and future

Parkinson's disease (PD) researchers have pioneered the use of cell-based therapies (CBTs) in the central nervous system. CBTs for PD were originally envisioned as a way to replace the dopaminergic nigral neurons lost with the disease. Several sources of catecholaminergic cells, including autografts of adrenal medulla and allografts or xenografts of mesencephalic fetal tissue, were successfully assessed in animal models, but their clinical translation has yielded poor results and much controversy. Recent breakthroughs on cell biology are helping to develop novel cell lines that could be used for regenerative medicine. Their future successful clinical application depends on identifying and solving the problems encountered in previous CBTs trials. In this review, we critically analyze past CBTs' clinical translation, the impact of the host in graft survival, and the role of preclinical studies and emerging new cell lines. We propose that the prediction of clinical results from preclinical studies requires experimental designs that allow blind data acquisition and statistical analysis, assessment of the therapy in models that parallel clinical conditions, looking for sources of complications or side effects, and limiting optimism bias when reporting outcomes.

Preclinical assessment of stem cell therapies for neurological diseases

Stem cells, as subjects of study for use in treating neurological diseases, are envisioned as a replacement for lost neurons and glia, a means of trophic support, a therapeutic vehicle, and, more recently, a tool for in vitro modeling to understand disease and to screen and personalize treatments. In this review we analyze the requirements of stem cell-based therapy for clinical translation, advances in stem cell research toward clinical application for neurological disorders, and different animal models used for analysis of these potential therapies. We focus on Parkinson's disease (typically defined by the progressive loss of dopaminergic nigral neurons), stroke (neurodegeneration associated with decreased blood perfusion in the brain), and multiple sclerosis (an autoimmune disorder that generates demyelination, axonal damage, astrocytic scarring, and neurodegeneration in the brain and spinal cord). We chose these disorders for their diversity and the number of people affected by them. An additional important consideration was the availability of multiple animal models in which to test stem cell applications for these diseases. We also discuss the relationship between the limited number of systematic stem cell studies performed in animals, in particular nonhuman primates and the delayed progress in advancing stem cell therapies to clinical success.