Isolation, growth and differentiation of equine mesenchymal stem cells: effect of donor, source, amount of tissue and supplementation with basic fibroblast growth factor

Effect of basic fibroblast growth factor on pluripotent marker expression and colony forming unit capacity of stem cells isolated from human exfoliated deciduous teeth

Human dental pulp of exfoliated deciduous teeth contains the population of cells that exhibited mesenchymal stem cell (MSC) characters. Though, a cell amplification process is indeed required to secure an adequate cell number for such a potential employment. Several publications suggested the alteration of MSCs upon in vitro culture, for example, the decrease in proliferation and the loss of stem cell characters. Here, we investigated an influence of basic fibroblast growth factor (bFGF) on stem cells isolated from human exfoliated deciduous teeth (SHEDs) with respect to cell proliferation, colony forming unit efficiency and stem cell marker expression in both short- and long-term cultures. For short-term bFGF treatment, SHEDs were treated with bFGF for 48 h. While, in long-term bFGF supplementation, SHEDs were maintained in culture and continuous passage upon confluence in medium supplemented with bFGF. Cells at passage (P) 5 and 10 were employed for characterization. Our results showed that short-term bFGF treatment enhanced OCT4, REX1, and NANOG mRNA expression as well as colony forming unit ability. The FGFR inhibitor pretreatment was able to attenuate the influence of bFGF on pluripotent stem cell marker expression, confirming bFGF function. In addition, cells cultured in high passage number had decreased in cell proliferation, colony forming unit capacity, and pluripotent stem cell maker mRNA expression. However, bFGF supplementation in culture medium enhanced both pluripotent stem cell marker expression and colony forming unit capacity in later passage, though the effect was not robust. Together, these results indicate that high passage number may attenuate pluripotent properties of SHEDs and bFGF supplementation could be the beneficial approach to maintain SHEDs' stemness properties.

Isolation and multilineage differentiation of bone marrow mesenchymal stem cells from abattoir-derived bovine fetuses

Background

Mesenchymal stem cells (MSC) are multipotent progenitor cells localized in the stromal compartment of the bone marrow (BM). The potential of MSC for mesenchymal differentiation has been well documented in different animal models predominantly on rodents. However, information regarding bovine MSC (bMSC) is limited, and the differentiation potential of bMSC derived from fetal BM remains unknown. In the present study we sought to isolate bMSC from abattoir-derived fetal BM and to characterize the multipotent and differentiation potential under osteogenic, chondrogenic and adipogenic conditions by quantitative and qualitative analyses.

Results

Plastic-adherent bMSC isolated from fetal BM maintained a fibroblast-like morphology under monolayer culture conditions. These cells expressed high levels of MSC surface markers (CD73, CD90, and CD105) and low levels of hematopoietic surface markers (CD34 and CD45). Culture of bMSC under osteogenic conditions during a 27-day period induced up-regulation of the osteocalcin (OC) gene expression and alkaline phosphatase (ALPL) activity, and promoted mineralization of the matrix. Increasing supplementation levels of ascorbic acid to culture media enhanced osteogenic differentiation of bMSC; whereas, reduction of FBS supplementation compromised osteogenesis. bMSC increased expression of cartilage-specific genes aggrecan (ACAN), collagen 2A1 (COL2A1) and SRY (sex-determining region Y) box 9 (SOX9) at Day 21 of chondrogenic differentiation. Treatment of bMSC with adipogenic factors increased levels of fatty acid-binding protein 2 (AP2) mRNA and accumulation of lipid vacuoles after 18 days of culture. NANOG mRNA levels in differentiating bMSC were not affected during adipogenic culture; however, osteogenic and chondrogenic conditions induced higher and lower levels, respectively.

Conclusions

Our analyses revealed the potential multilineage differentiation of bMSC isolated from abattoir-derived fetal BM. NANOG mRNA pattern in differentiating bMSC varied according to differentiation culture conditions. The osteogenic differentiation of bMSC was affected by ascorbic acid and FBS concentrations in culture media. The simplicity of isolation and the differentiation potential suggest that bMSC from abattoir-derived fetal BM are appropriate candidate for investigating MSC biology and for eventual applications for regenerative therapy.

Investigating the efficacy of amnion-derived compared with bone marrow-derived mesenchymal stromal cells in equine tendon and ligament injuries

BACKGROUND AIMS

This is the first study to compare the treatment of horse tendon and ligament injuries with the use of mesenchymal stromal cells (MSCs) obtained from two different sources: amniotic membrane (AMSCs) and bone marrow (BM-MSCs). The objective was to prove the ability of AMSCs to exert beneficial effects in vivo.

METHODS

Five million allogeneic frozen-thawed AMSCs or autologous fresh BM-MSCs were injected intralesionally in horses belonging to group A (51 horses) and group B (44 horses). The interval lesion/implantation was of 6-15 days for the AMSCs and 16-35 days for the BM-MSCs. Healing was assessed clinically and ultrasonographically. Follow-up was monitored for 2 further years from return to full work.

RESULTS

No significant adverse effects after MSCs treatment were seen in any of the horses studied, independent of the type of stromal cell implanted. All animals belonging to group A resumed their activities between 4-5 months after treatment, whereas animals of group B resumed their activities after 4-12 months. The rate of re-injury in horses treated with AMSCs is lower (4.00%) compared with the average observed when horses were treated with BM-MSCs (23.08%).

CONCLUSIONS

The possibility to inject allogeneic AMSCs in real time, before any ultrasonographic change occurs within the injured tendon and ligament, together with the higher plasticity and proliferative capacity of these cells compared with BM-MSCs, represents the main features of interest for this novel approach for the treatment of equine tendon diseases. An obvious active proliferative healing in the area injected with AMSCs makes these cells more effective than BM-MSCs.

Exposure to transforming growth factor-β1 after basic fibroblast growth factor promotes the fibroblastic differentiation of human periodontal ligament stem/progenitor cell lines

Basic fibroblast growth factor (bFGF) is a cytokine that promotes the regeneration of the periodontium, the specialized tissues supporting the teeth. bFGF, does not, however, induce the synthesis of smooth muscle actin alpha 2 (ACTA2), type I collagen (COL1), or COL3, which are principal molecules in periodontal ligament (PDL) tissue, a component of the periodontium. We have suggested the feasibility of using transforming growth factor-β1 (TGFβ1) to induce fibroblastic differentiation of PDL stem/progenitor cells (PDLSCs). Here, we investigated the effect of the subsequent application of TGFβ1 after bFGF (bFGF/TGFβ1) on the differentiation of PDLSCs into fibroblastic cells. We first confirmed the expression of bFGF and TGFβ1 in rat PDL tissue and primary human PDL cells. Receptors for both bFGF and TGFβ1 were expressed in the human PDLSC lines 1-11 and 1-17. Exposure to bFGF for 2 days promoted vascular endothelial growth factor gene and protein expression in both cell lines and down-regulated the expression of ACTA2, COL1, and COL3 mRNA in both cell lines and the gene fibrillin 1 (FBN1) in cell line 1-11 alone. Furthermore, bFGF stimulated cell proliferation of these cell lines and significantly increased the number of cells in phase G2/M in the cell lines. Exposure to TGFβ1 for 2 days induced gene expression of ACTA2 and COL1 in both cell lines and FBN1 in cell line 1-11 alone. BFGF/TGFβ1 treatment significantly up-regulated ACTA2, COL1, and FBN1 expression as compared with the group treated with bFGF alone or the untreated control. This method might thus be useful for accelerating the generation and regeneration of functional periodontium.

Collection and propagation methods for mesenchymal stromal cells

Mesenchymal stromal cells (MSC) are derived from adult mesenchymal tissues and have the ability to undergo differentiation into bone, cartilage, and fat, and have therefore attracted great interest in regenerative medicine. Many isolation and culture methods have been described, making comparison between laboratories and quality-control protocols difficult. A uniform protocol to characterize equine MSC has recently been proposed, aiming to introduce consistency across the equine stem cell research field. This article reviews the published techniques for collection and propagation of equine MSC, focusing on bone marrow-derived and adipose-derived cells.

Mesenchymal stem cells: characteristics, sources, and mechanisms of action

This article provides an overview of mesenchymal stem cell (MSC) biology. In the first section, the characteristics that are routinely used to define MSCs-adherence, proliferation, multi-lineage potential, and "cluster of differentiation" marker profiles-are discussed. In the second section, the major tissues and body fluids that are used as sources for equine MSCs are presented, along with the comparative biologic activities of MSCs from specific locations. Finally, the current understanding of the mechanisms by which MSCs influence repair and regeneration are discussed, with an emphasis on the clinical importance of MSC trophic activities.

Isolation, culture and chondrogenic differentiation of canine adipose tissue- and bone marrow-derived mesenchymal stem cells--a comparative study

In the dog, mesenchymal stem cells (MSCs) have been shown to reside in the bone marrow (bone marrow-derived mesenchymal stem cells: BM-MSCs) as well as in the adipose tissue (adipose tissue-derived stem cells: ADSCs). Potential application fields for these multipotent MSCs in small animal practice are joint diseases as MSCs of both sources have shown to possess chondrogenic differentiation ability. However, it is not clear whether the chondrogenic differentiation potential of cells of these two distinct tissues is truly equal. Therefore, we compared MSCs of both origins in this study in terms of their chondrogenic differentiation ability and suitability for clinical application. BM-MSCs harvested from the femoral neck and ADSCs from intra-abdominal fat tissue were examined for their morphology, population doubling time (PDT) and CD90 surface antigen expression. RT-PCR served to assess expression of pluripotency marker Oct4 and early differentiation marker genes. Chondrogenic differentiation ability was compared and validated using histochemistry, transmission electron microscopy (TEM) and quantitative RT-PCR. Both cell populations presented a highly similar morphology and marker expression in an undifferentiated stage except that freshly isolated ADSCs demonstrated a significantly faster PDT than BM-MSCs. In contrast, BM-MSCs revealed a morphological superior cartilage formation by the production of a more abundant and structured hyaline matrix and higher expression of lineage specific genes under the applied standard differentiation protocol. However, further investigations are necessary in order to find out if chondrogenic differentiation can be improved in canine ADSCs using different protocols and/or supplements.

Stem cell-based tissue engineering in veterinary orthopaedics

Regenerative medicine is one of the most intensively researched medical branches, with enormous progress every year. When it comes to translating research from bench to bedside, many of the pioneering innovations are achieved by cooperating teams of human and veterinary medical scientists. The veterinary profession has an important role to play in this new and evolving technology, holding a great scientific potential, because animals serve widely as models for human medicine and results obtained from animals may serve as preclinical results for human medicine. Regenerative veterinary medicine utilizing mesenchymal stromal cells (MSC) for the treatment of acute injuries as well as chronic disorders is gradually turning into clinical routine. As orthopaedic disorders represent a major part of all cases in veterinary clinical practice, it is not surprising that they are currently taking a leading role in MSC therapies. Therefore, the purpose of this paper is to give an overview on past and current achievements as well as future perspectives in stem cell-based tissue engineering in veterinary orthopaedics.

Isolation, characterization and differentiation of mesenchymal stem cells from amniotic fluid, umbilical cord blood and Wharton's jelly in the horse

Mesenchymal stem cells (MSCs) have been derived from multiple sources of the horse including umbilical cord blood (UCB) and amnion. This work aimed to identify and characterize stem cells from equine amniotic fluid (AF), CB and Wharton's Jelly (WJ). Samples were obtained from 13 mares at labour. AF and CB cells were isolated by centrifugation, while WJ was prepared by incubating with an enzymatic solution for 2  h. All cell lines were cultured in DMEM/TCM199 plus fetal bovine serum. Fibroblast-like cells were observed in 7/10 (70%) AF, 6/8 (75%) CB and 8/12 (66.7%) WJ samples. Statistically significant differences were found between cell-doubling times (DTs): cells isolated from WJ expanded more rapidly (2.0±0.6 days) than those isolated from CB (2.6±1.3 days) and AF (2.3±1.0 days) (P<0.05). Positive von Kossa and Alizarin Red S staining confirmed osteogenesis. Alcian Blue staining of matrix glycosaminoglycans illustrated chondrogenesis and positive Oil Red O lipid droplets staining suggested adipogenesis. All cell lines isolated were positive for CD90, CD44, CD105; and negative for CD34, CD14 and CD45. These findings suggest that equine MSCs from AF, UCB and WJ appeared to be a readily obtainable and highly proliferative cell lines from a uninvasive source that may represent a good model system for stem cell biology and cellular therapy applications in horses. However, to assess their use as an allogenic cell source, further studies are needed for evaluating the expression of markers related to cell immunogenicity.

Immunophenotype and gene expression profiles of cell surface markers of mesenchymal stem cells derived from equine bone marrow and adipose tissue

Bone marrow and adipose tissue are the two main sources of mesenchymal stem cell (MSC). The aim of this work was to analyse the immunophenotype of 7 surface markers and the expression of a panel of 13 genes coding for cell surface markers in equine bone marrow and adipose tissue-derived MSCs obtained from 9 horses at third passage. The tri-lineage differentiation was confirmed by specific staining. Equine MSCs from both sources were positive for the MSC markers CD29 and CD90, while were negative for CD44, CD73, CD105, CD45 and CD34. The gene expression of these molecules was also evaluated by reverse transcriptase real-time quantitative PCR along with the expression of 5 other MSC markers. Both populations of cells expressed CD13, CD29, CD44, CD49d, CD73, CD90, CD105, CD106, CD146 and CD166 transcripts. Significant differences in gene expression levels between BM- and AT-MSCs were observed for CD44, CD90, CD29 and CD34. Both cell types were negative for CD45 and CD31. The surface antigens tested revealed a similar phenotypic profile between horse and human MSCs, although specific differences in some surface antigens were noticed.

Commercial cell-based therapies for musculoskeletal injuries in horses

Several cell-based therapeutic options to treat musculoskeletal injuries in horses are commercially available. The current literature supports the use of cell-based therapies to treat equine musculoskeletal injuries. Researchers continue to search for more effective cell-based therapies to provide practitioners with optimal treatment tools for musculoskeletal injuries in horses. Cell-based therapies require specialized facilities and technical competencies that might not be available or economically justifiable in many private practices. This review provides a summary of current commercially available cell-based therapeutic products for equine applications, their similarities and differences, and current objective data relating to their clinical efficacy.

Further insights into the characterization of equine adipose tissue-derived mesenchymal stem cells

Adipose tissue-derived stem cells (ADSCs) represent a promising subpopulation of adult stem cells for tissue engineering applications in veterinary medicine. In this study we focused on the morphological and molecular biological properties of the ADSCs. The expression of stem cell markers Oct4, Nanog and the surface markers CD90 and CD105 were detected using RT-PCR. ADSCs showed a proliferative potential and were capable of adipogenic and osteogenic differentiation. Expression of Alkaline phosphatase (AP), phosphoprotein (SPP1), Runx2 and osteocalcin (OC) mRNA were positive in osteogenic lineages and peroxisome proliferator activated receptor (Pparγ2) mRNA was positive in adipogenic lineages. ADSCs show stem cell and surface marker profiles and differentiation characteristics that are similar to but distinct from other adult stem cells, such as bone marrow-derived mesenchymal stem cells (BM-MSCs). The availability of an easily accessible and reproducible cell source may greatly facilitate the development of stem cell based tissue engineering and therapies for regenerative equine medicine.

The regenerative medicine laboratory: facilitating stem cell therapy for equine disease

This article focuses on the emerging field of equine regenerative medicine with an emphasis on the use of mesenchymal stem cells (MSCs) for orthopedic diseases. We detail laboratory procedures and protocols for tissue handling and MSC isolation, characterization, expansion, and cryopreservation from bone marrow, fat, and placental tissues. We provide an overview of current clinical uses for equine MSCs and how MSCs function to heal tissues. Current laboratory practices in equine regenerative medicine mirror those in the human field. However, the translational use of autologous and allogeneic MSCs for patient therapy far exceeds what is currently permitted in human medicine.

Adipogenic differentiation of adult equine mesenchymal stromal cells

Equine adipose tissue-derived mesenchymal stem cells (ASCs) have only recently been investigated for their adipogenic, chondrogenic, and osteogenic differentiation potential. This chapter will briefly outline the molecular mechanisms leading to adipogenesis and the methods of equine adipose tissue harvest, ASC isolation, and adipogenic differentiation. The reader is also directed to other reported methods of adipogenesis for ASCs and mesenchymal stem cells (MSCs) from other tissues.

Virally and physically transgenized equine adipose-derived stromal cells as a cargo for paracrine secreted factors

BACKGROUND

Adipose-Derived Stromal Cells have been shown to have multiple lineage differentiation properties and to be suitable for tissues regeneration in many degenerative processes. Their use has been proposed for the therapy of joint diseases and tendon injuries in the horse. In the present report the genetic manipulation of Equine Adipose-Derived Stromal Cells has been investigated.

RESULTS

Equine Adipose-Derived Stromal Cells were successfully virally transduced as well as transiently and stably transfected with appropriate parameters, without detrimental effect on their differentiation properties. Moreover, green fluorescent protein alone, fused to neo gene, or co-expressed as bi-cistronic reporter constructs, driven by viral and house-keeping gene promoters, were tested. The better expressed cassette was employed to stably transfect Adipose-Derived Stromal Cells for cell therapy purposes. Stably transfected Equine Adipose-Derived Stromal Cells with a heterologous secreted viral antigen were able to immunize horses upon injection into the lateral wall of the neck.

CONCLUSION

This study provides the methods to successfully transgenize Adipose-Derived Stromal Cells both by lentiviral vector and by transfection using optimized constructs with suitable promoters and reporter genes. In conclusion these findings provide a working platform for the delivery of potentially therapeutic proteins to the site of cells injection via transgenized Equine Adipose-Derived Stromal Cells.