Refinement of Culture Conditions for Maintenance of Undifferentiated Equine Umbilical Cord Blood Stem Cells

Outlook of Adipose-Derived Stem Cells: Challenges to Their Clinical Application in Horses

Adipose tissue is recognized as the major endocrine organ, potentially acting as a source of mesenchymal stem cells for various applications in regenerative medicine. Athletic horses are often exposed to traumatic injuries, resulting in severe financial losses. The development of adipose-derived stem cells' regenerative potential depends on many factors. The extraction of stem cells from subcutaneous adipose tissue is non-invasive, non-traumatic, cheaper, and safer than other sources. Since there is a lack of unique standards for identification, the isolated cells and applied differentiation protocols are often not species-specific; therefore, the cells cannot reveal their multipotent properties, so their stemness features remain questionable. The current review discusses some aspects of the specificity of equine adipose stem cells concerning their features, immunophenotyping, secretome profile, differentiation abilities, culturing conditions, and consequent possibilities for clinical application in concrete disorders. The presented new approaches elucidate the possibility of the transition from cell-based to cell-free therapy with regenerative purposes in horses as an alternative treatment to cellular therapy. In conclusion, their clinical benefits should not be underestimated due to the higher yield and the physiological properties of adipose-derived stem cells that facilitate the healing and tissue regeneration process and the ability to amplify the effects of traditional treatments. More profound studies are necessary to apply these innovative approaches when treating traumatic disorders in racing horses.

Current Status of Canine Umbilical Cord Blood-Derived Mesenchymal Stem Cells in Veterinary Medicine

Stem cell therapy has prompted the expansion of veterinary medicine both experimentally and clinically, with the potential to contribute to contemporary treatment strategies for various diseases and conditions for which limited or no therapeutic options are presently available. Although the application of various types of stem cells, such as bone marrow-derived mesenchymal stem cells (BM-MSCs), adipose tissue-derived mesenchymal stem cells (AT-MSCs), and umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs), has promising potential to improve the health of different species, it is crucial that the benefits and drawbacks are completely evaluated before use. Umbilical cord blood (UCB) is a rich source of stem cells; nonetheless, isolation of mesenchymal stem cells (MSCs) from UCB presents technical challenges. Although MSCs have been isolated from UCB of diverse species such as human, equine, sheep, goat, and canine, there are inherent limitations of using UCB from these species for the expansion of MSCs. In this review, we investigated canine UCB (cUCB) and compared it with UCB from other species by reviewing recent articles published from February 2003 to June 2017 to gain an understanding of the limitations of cUCB in the acquisition of MSCs and to determine other suitable sources for the isolation of MSCs from canine. Our review indicates that cUCB is not an ideal source of MSCs because of insufficient volume and ethical issues. However, canine reproductive organs discarded during neutering may help broaden our understanding of effective isolation of MSCs. We recommend exploring canine reproductive and adipose tissue rather than UCB to fulfill the current need in veterinary medicine for the well-designed and ethically approved source of MSCs.

Bezerra-Junior R, Câmara LM, Albuquerque-Pinto LC, Teixeira MF. Isolation, culture and characterization of multipotent mesenchymal stem cells from goat umbilical cord blood

ABSTRACT: Mesenchymal stem cells (MSC) reside in small numbers in many adult tissues and organs, and play an active role in the homeostasis of these sites. Goat derived multipotent MSC have been established from bone marrow, adipose tissues and amniotic fluid. Umbilical cord blood (UCB) is considered an important source of these cells. However, the MSC isolation from the goat UCB has not been demonstrated. Therefore, the aim of the present study was to isolate, culture and characterize goat umbilical cord blood derived mesenchymal stem cells. MSC were isolated from UCB by Ficoll-Paque density centrifugation and cultured in DMEM supplemented with 10% or 20% FBS. FACS analysis was performed and induction lineage differentiation was made to characterize these cells. They exhibited two different populations in flow cytometry, and revealed the positive expression of CD90, CD44 and CD105, but negative staining for CD34 in larger cells, and positive stained for CD90 and CD105, but negative for CD44 and CD34 in the smaller cells. MSC from goat UCB showed capability to differentiate into chondrocytes and osteoblasts when incubated with specific differentiation medium. Present study established that goat mesenchymal stem cells can be derived successfully from umbilical cord blood.

Goat umbilical cord cells are permissive to small ruminant lentivirus infection in vitro

Small ruminant lentiviruses isolated from peripheral blood leukocytes and target organs can be propagated in vitro in fibroblasts derived from goat synovial membrane cells. These cells are obtained from tissues collected from embryos or fetuses and are necessary for the establishment of the fibroblast primary culture. A new alternative type of host cells, derived from goat umbilical cord, was isolated and characterized phenotypically with its main purpose being to obtain cell monolayers that could be used for the diagnosis and isolation of small ruminant lentiviruses in cell culture. To accomplish this goal, cells were isolated from umbilical cords; characterized phenotypically by flow cytometry analysis; differentiate into osteogenic, chondrogenic and adipogenic lineage; and submitted to viral challenge. The proliferation of goat umbilical cord cells was fast and cell monolayers formed after 15 days. These cells exhibited morphology, immunophenotype, growth characteristics, and lineage differentiation potential similar to mesenchymal stem cells of other origins. The goat umbilical cord derived cells stained positive for vimentin and CD90, but negative for cytokeratin, CD34 and CD105 markers. Syncytia and cell lysis were observed in cell monolayers infected by CAEV-Cork and MVV-K1514, showing that the cells are permissive to small ruminant lentivirus infection in vitro. These data demonstrate the proliferative competence of cells derived from goat umbilical cords and provide a sound basis for future research to standardize this cell lineage.

Expression of scleraxis and tenascin C in equine adipose and umbilical cord blood derived stem cells is dependent upon substrata and FGF supplementation

Recovery from tendon injury is based on long periods of rest, which results in sub-optimal repair, often replacing tendon with fibrocartilage scar tissue. Recently, the use of stem cells in equine tendon repair has been attempted with variable success. The objective of this work was to determine the expression of scleraxis (scx) and tenascin C (TnC), two markers of tenocytes, in adipose (AdMSC) and umbilical cord blood (UCB) stem cells during culture on various substrata and in response to fibroblast growth factor (FGF) treatment. Equine UCB and AdMSC were cultured on gelatin-coated plasticware, 30 % matrigel or collagen-coated Cytodex beads and treated with 10 ng/ml FGF2, FGF4 or FGF5 prior to measurement of proliferation, kinase activity and tenocyte gene expression. Supplementation with FGF2 or FGF5 activated the ERK1/2 signaling pathway in AdMSC and UCB; no effect of FGF4 was observed in UCB. FGF2 increased proliferation in AdMSC but not UCB. Conversely, FGF5 stimulated proliferation of UCB. Culture in matrigel increased scx expression in both cell populations and increased TnC in AdMSC. In AdMSC grown in matrigel, supplementation with FGF2 or FGF5 increased TnC expression. Thus, culture conditions (substrata and FGF supplementation) impact markers of tenocytes in AdMSC and UCB stem cells, indicating that careful consideration should be given to culture conditions prior to use of UCB or AdMSC as therapeutic aids. Optimal culture conditions may promote early differentiation of these cells, improving their ability to aid tendon regeneration and facilitating more efficient recovery from tendon injury.