Replicative aging and differentiation potential of human adipose tissue-derived mesenchymal stromal cells expanded in pooled human or fetal bovine serum

A xeno-free culture method that enhances Wharton's jelly mesenchymal stromal cell culture efficiency over traditional animal serum-supplemented cultures

BACKGROUND AIMS

Mesenchymal stromal cell (MSC) transplantation holds great promise for use in medical therapies. Several key features of MSCs, including efficient cell growth, generation of sufficient cell numbers and safety, as determined by teratoma formation, make MSCs an ideal candidate for clinical use. However, MSCs derived under standard culture conditions, co-cultured with animal by-products, are inappropriate for therapy because of the risks of graft rejection and animal virus transmission to humans. Alternative serum sources have been sought for stem cell production.

METHODS

We demonstrate for the first time that human serum from umbilical cord blood (hUCS) is an effective co-culture reagent for MSC production from Wharton's jelly MSCs (WJMSCs). Ten umbilical cords were used to generate parallel cultures of WJMSC lines under medium supplemented with hUCS and embryonic stem cell-qualified fetal bovine serum. The WJMSC lines from each medium were analyzed and compared with regard to cell line derivation, proliferation ability and characteristic stability.

RESULTS

The phenotypic characteristics of WJMSC derived under either medium showed no differences. WJMSC lines derived under hUCS medium displayed comparable primary culture cell outgrowth, lineage differentiation capacity and cell recovery after cryopreservation compared with supplementation with embryonic stem cell-qualified fetal bovine serum medium. However, superior cell proliferation rates and retention of in vitro propagation (>22 passages) were observed in WJMSC cultures supplemented with hUCS. Additionally, more robust population doubling times were observed in hUCS-supplemented cultures.

CONCLUSIONS

We conclude that hUCS is an efficient and effective serum source for animal product-free WJMSC line production and can generate MSC lines that may be appropriate for therapeutic use.

Serum-free media for the production of human mesenchymal stromal cells: a review

The regenerative potential of mesenchymal stromal cells (MSC) holds great promise in using them for treatment of a wide range of debilitating diseases. Several types of culture media and systems have been used for large-scale expansion of MSCs in vitro; however, the majority of them rely heavily on using foetal bovine serum (FBS)-supplement for optimal cell proliferation. FBS-based cultures pose the potential threat of spread of transmissible spongiform encephalopathy and bovine spongiform encephalopathy to MSCs and then to their recipients. A recent trend in cell culture is to change from serum-use to serum-free media (SFM). In this context, the current review focuses specifically on employment of various SFM for MSCs and discusses existences of various options with which to substitute FBS. In addition, we analyse MSC population growth kinetic patterns using various SFM for large-scale production of MSCs.

Character comparison of abdomen-derived and eyelid-derived mesenchymal stem cells

OBJECTIVES

While most human adipose tissues, such as those located in the abdomen, hip and thigh, are of mesodermal origin, adipose tissues located in the face are of ectodermal origin. The present study has compared stem cell-related features of abdomen-derived adult stem cells (A-ASCs) with those of eyelid-derived adult stem cells (E-ASCs).

MATERIALS AND METHODS

Adipose tissue-derived cells were maintained in DMEM supplemented with 10% FBS. Before passage 6, cells were analysed using FACS, immunocytochemistry and quantitative real time PCR (qRT-PCR). To examine multi-differentiational potential, early passage ASCs were cultivated in each of a commercial Stempro(®) Differentiation kit.

RESULTS

Unlike fibroblast-like morphology of A-ASCs, E-ASCs had bipolar morphology. Both types of cell exhibited similar surface antigens, and neuronal cell-related genes and proteins. However, there were differences in mRNA expression levels of CD90 and CD146; neuron-specific enolase (NSE) and nuclear receptor-related protein 1 (Nurr1) were different between the two cell types. There was no difference in multi-differentiational potential between 3 E-ASCs lines, however, E-ASCs had higher expression levels of chondrocyte-related genes compared to A-ASCs. These cells underwent senescence and maintained normal karyotypes.

CONCLUSIONS

Although isolated from similar adipose tissues, both types of cells displayed many contrasting characteristics. Understanding defining phenotypes of such cells is useful for making suitable choices in differing clinical indications.

Isolation, characterization, and transduction of endometrial decidual tissue multipotent mesenchymal stromal/stem cells from menstrual blood

Mesenchymal stromal/stem cells (MSCs) reveal progenitor cells-like features including proliferation and differentiation capacities. One of the most historically recognized sources of MSC has been the bone marrow, while other sources recently include adipose tissue, teeth, bone, muscle, placenta, liver, pancreas, umbilical cord, and cord blood. Frequently, progenitor isolation requires traumatic procedures that are poorly feasible and associated with patient discomfort. In the attempt to identify a more approachable MSC source, we focused on endometrial decidual tissue (EDT) found within menstrual blood. Based also on recent literature findings, we hypothesized that EDT may contain heterogeneous populations including some having MSC-like features. Thus, we here sought to isolate EDT-MSC processing menstrual samples from multiple donors. Cytofluorimetric analyses revealed that resulting adherent cells were expressing mesenchymal surface markers, including CD56, CD73, CD90, CD105 and CD146, and pluripotency markers such as SSEA-4. Moreover, EDT-MSC showed a robust clonogenic potential and could be largely expanded in vitro as fibroblastoid elements. In addition, differentiation assays drove these cells towards osteogenic, adipogenic, and chondrogenic lineages. Finally, for the first time, we were able to gene modify these progenitors by a retroviral vector carrying the green fluorescent protein. From these data, we suggest that EDT-MSC could represent a new promising tool having potential within cell and gene therapy applications.

Effects of different serum conditions on osteogenic differentiation of human adipose stem cells in vitro

INTRODUCTION

Currently, human adipose stem cells (hASCs) are differentiated towards osteogenic lineages using culture medium supplemented with L-ascorbic acid 2-phosphate (AsA2-P), dexamethasone (Dex) and beta-glycerophosphate (β-GP). Because this osteogenic medium (OM1) was initially generated for the differentiation of bone marrow-derived mesenchymal stem cells, the component concentrations may not be optimal for the differentiation of hASCs. After preliminary screening, two efficient osteogenic media (OM2 and OM3) were chosen to be compared with the commonly used osteogenic medium (OM1). To further develop the culture conditions towards clinical usage, the osteo-inductive efficiencies of OM1, OM2 and OM3 were compared using human serum (HS)-based medium and a defined, xeno-free medium (RegES), with fetal bovine serum (FBS)-based medium serving as a control.

METHODS

To compare the osteo-inductive efficiency of OM1, OM2 and OM3 in FBS-, HS- and RegES-based medium, the osteogenic differentiation was assessed by alkaline phosphatase (ALP) activity, mineralization, and expression of osteogenic marker genes (runx2A, DLX5, collagen type I, osteocalcin, and ALP).

RESULTS

In HS-based medium, the ALP activity increased significantly by OM3, and mineralization was enhanced by both OM2 and OM3, which have high AsA2-P and low Dex concentrations. ALP activity and mineralization of hASCs was the weakest in FBS-based medium, with no significant differences between the OM compositions due to donor variation. However, the qRT-PCR data demonstrated significant upregulation of runx2A mRNA under osteogenic differentiation in FBS- and HS-based medium, particularly by OM3 under FBS conditions. Further, the expression of DLX5 was greatly stimulated by OM1 to 3 on day 7 when compared to control. The regulation of collagen type I, ALP, and osteocalcin mRNA was modest under induction by OM1 to 3. The RegES medium was found to support the proliferation and osteogenic differentiation of hASCs, but the composition of the RegES medium hindered the comparison of OM1, OM2 and OM3.

CONCLUSIONS

Serum conditions affect hASC proliferation and differentiation significantly. The ALP activity and mineralization was the weakest in FBS-based medium, although osteogenic markers were upregulated on mRNA level. When comparing the OM composition, the commonly used OM1 was least effective. Accordingly, higher concentration of AsA2-P and lower concentration of Dex, as in OM2 and OM3, should be used for the osteogenic differentiation of hASCs in vitro.

Expansion of Mesenchymal Stem/Stromal cells under xenogenic-free culture conditions

Mesenchymal Stem/Stromal cells (MSCs) are increasingly applied in cell-based regenerative medicine. To yield clinically relevant cell doses, ex vivo expansion of MSCs is required to be compliant with good manufacturing practice (GMP) guidelines. A lack of standardization and harmonization seems to hamper rapid progress in the translational phase. Most protocols still use fetal bovine serum (FBS) to expand MSCs. However, the high lot-to-lot variability, risk of contamination and immunization call for xenogenic-free culture conditions. Chemically defined media are the ultimate achievement in terms of standardization. These media, however, need to maintain all key cellular and therapy-relevant features of MSCs. Because of the numerous constituents of FBS, the development of such chemically defined media with an optimal composition of the few essential factors is only beginning. Meanwhile, various human blood-derived components are under investigation, including human plasma, human serum, human umbilical cord blood serum and human platelet derivatives such as platelet lysate.