Mesenchymal stem cells from amnion and amniotic fluid in the bovine

Amnion and amniotic fluid (AF) are noncontroversial and inexhaustible sources of mesenchymal stem cells (MSCs) that can be harvested noninvasively at low cost. As in humans, also in veterinary field, presumptive stem cells derived from these tissues reveal as promising candidates for disease treatment, specifically for their plasticity, their reduced immunogenicity, and high anti-inflammatory potential. The aim of this work is to obtain and characterize, for the first time in bovine species, presumptive MSCs from the epithelial portion of the amnion (AECs) and from the AF (AF-MSCs) to be used for clinical applications. AECs display a polygonal morphology, whereas AF-MSCs exhibit a fibroblastic-like morphology only starting from the second passage, being heterogeneous during the primary culture. For both lines, the proliferative ability has been found constant over the ten passages studied and AECs show a statistically lower (P<0.05) doubling time with respect to AF-MSCs. AECs express MSC-specific markers (ITGB1(CD29),CD44,ALCAM(CD166),ENG(CD105), andNT5E(CD73)) from P1 to P3; in AF-MSCs, onlyITGB1,CD44, andALCAMmRNAs are detected;NT5Eis expressed from P2 andENGhas not been found at any passage. AF-MSCs and AECs are positive for the pluripotent markers (POU5F1(OCT4) andMYC(c-Myc)) and lack of the hematopoietic markers. When appropriately induced, both cell lines are capable of differentiating into ectodermal and mesodermal lineages. This study contributes to reinforce the emerging importance of these cells as ideal tools in veterinary medicine. A deeper evaluation of the immunological properties needs to be performed in order to better understand their role in cellular therapy.

Characteristics of equine mesenchymal stem cells derived from amnion and bone marrow: in vitro proliferative and multilineage potential assessment

REASONS FOR PERFORMING STUDY

This is the first study comparing stemness features of equine mesenchymal progenitor cells derived from amniotic membrane and bone marrow.

OBJECTIVES

To investigate an alternative and noninvasive stromal cell source for equine tissue engineering.

STUDY DESIGN

In vitro experimental study of the characteristics of equine mesenchymal progenitor cells derived from amnion and bone marrow.

METHODS

Cells isolated from amniotic membrane and bone marrow were analysed for proliferation (growth curve, doubling time, colony forming unit). Immunocytochemical detection of pluripotency markers and gene expression of stromal cell markers were also performed and these cells were studied for multilineage plasticity.

RESULTS

Amniotic stromal cells (AMSCs) and bone marrow mesenchymal cells (BM-MSCs) both exhibited mature stromal cell-specific gene expression and immunocytochemical properties, but showed substantial differences in their proliferative and differentiation potential. The mean doubling time for AMSCs was significantly lower (P<0.05) than that observed for BM-MSCs (1.17 ± 0.15 vs. 3.27 ± 0.19 days, respectively). Compared to AMSCs, BM-MSCs also demonstrated a significantly (P<0.05) lower clonogenic capability (one fibroblast-like colony forming unit from a mean of 590.15 cells seeded for BM-MSCs vs. 242.73 cells seeded for AMSCs). BM-MSCs did not differentiate into glial cells, and the osteogenic differentiation process was longer than for AMSCs.

CONCLUSIONS AND POTENTIAL RELEVANCE

The amniotic membrane could be a valuable source of MSCs to be used both for allogenic and/or autologous therapies. The noninvasive nature and low cost of collection, the rapid proliferation along with a greater differentiation potential and the 'off the shelf' preparation potential could make AMCs useful for cell therapy.

Fluorescent multiple staining and CASA system to assess boar sperm viability and membranes integrity in short and long-term extenders

The aim of this study was to assess the effect on boar spermatozoa quality of in vitro storage in short and long-term extenders by fluorescent multiple staining (FMS) and computer assisted semen analyzer (CASA). Fresh ejaculates from three healthy, sexually mature boars were diluted with equal volumes of six short-term or three long-term commercial extenders and stored at 19°C for 6 days (short-term) or 12 days (long-term). The integrity of spermatozoa membranes was analyzed by FMS using propidium iodide, 5,5',6,6'-tetrachloro-1,1',3,3' tetraethylbenzimidazolyl-carbocyanine iodide (JC-1) and fluorescein isothiocyanate-conjugated peanut agglutinin (PNA). The results obtained from this staining were compared with spermatozoa motility assessed by CASA. Our study showed that the number of viable spermatozoa with non-reacted acrosomes and intact mitochondria was positively correlated with the rate of motile spermatozoa (r(2)>0.9) irrespective of the extender used. In all extenders the number of motile spermatozoa significantly decreased as preservation period increased (P<0.05). FMS test is a potent indicator of sperm motility because it analyses mitochondrial integrity independently from observable alterations in motility. The best performing extenders were BTS for short-term storage and TRI-x-Cell for long-term storage.

295 EQUINE AMNION-DERIVED MESENCHYMAL STEM CELLS: POSSIBLE IMPLICATION IN ENDOMETRIAL REGENERATION

In veterinary medicine, as in human, amnion is an attractive source of mesenchymal stem cells (MSC), which poses no ethical dilemmas, allows highly efficient recovery of cells without the requirement of invasive procedures and shows immunomodulatory properties. We previously demonstrated that equine amniotic membrane-derived cells (AMC) not only exhibit specific stem cell properties with respect to expression of pluripotent (OCT-4, TRA-1-60, and SSEA-4) and adult (CD44, CD105, CD29, and CD166) stem cell markers but also possess differentiation potential in vitro and the capability to regenerate tendons in vivo after spontaneous lesions when allogeneically transplanted. Moreover, we reported evidence that at the first passages (P) in culture (until P5), AMC express MHC-class I but not MHC-class II and are well tolerated in vivo. In the present study, we further characterised AMC in vitro in order to evaluate their potential application in the treatment of endometritis in vivo. In particular, the amniotic membrane in toto and AMC have been compared to the endometrial tissue in toto and to cells isolated from endometrium for the expression of genes involved in the proliferation and differentiation of uterine MSC during early pregnancy (AbdB-like Hoxa genes) and those influencing preimplantation conceptus development (progesterone receptor, PR, and oestrogen receptors ERα and ERβ). The AMC were isolated as recently reported by Lange-Consiglio et al. (2011 Open J. Tissue Eng. Regen. Med. 4), and endometrial cells were obtained according to the protocol described by Donofrio et al. (2008 Reprod. Biol. Endocrinol. 6, 65) for bovine cells, and slightly modified for equine cells. Total RNA was extracted from both tissues and from AMC and endometrium-derived cells immediately after isolation (P0). Reverse transcription-PCR was performed according to the standard procedures, using GAPDH and HPRT1 as reference genes. Expression of HOXA9 and PR was confirmed in all samples examined, whereas mRNA for ERβ was only detected in endometrial tissue and in cells derived from it. Expression of ERα was observed only in endometrial tissue. The expression of genes crucially involved in patterning of the female reproductive tract (HOXA9 and PR) in amnion and cells derived from it suggests that this source shares similar molecular properties with endometrium. Further studies are required to explore uterine mesenchymal-like features shared by AMC (i.e. verifying the expression of Wnt7α, Wnt5α, and Wnt4α, or the presence of the more recently characterised membrane-bound intracellular progesterone receptors PGRMC1 and mPR). These preliminary results provide an intriguing indication of the possible implication of amnion-derived cells in endometrial regeneration, in particular when poor endometrial proliferation is associated with infertility or poor pregnancy outcome.