Isolation, culture and chondrogenic differentiation of canine adipose tissue- and bone marrow-derived mesenchymal stem cells--a comparative study. Vet Res Commun. 2012;36:139-148. [PMID: 22392598 DOI: 10.1007/s11259-012-9523-0]

Arthritic periosteal tissue from joint replacement surgery: a novel, autologous source of stem cells

The overarching aim of this study is to assess the feasibility of using periosteal tissue from the femoral neck of arthritic hip joints, usually discarded in the normal course of hip replacement surgery, as an autologous source of stem cells. In addition, the study aims to characterize intrinsic differences between periosteum-derived cell (PDC) populations, isolated via either enzymatic digestion or a migration assay, including their proliferative capacity, surface marker expression, and multipotency, relative to commercially available human bone marrow-derived stromal cells (BMSCs) cultured under identical conditions. Commercial BMSCs and PDCs were characterized in vitro, using a growth assay, flow cytometry, as well as assay of Oil Red O, alizarin red, and Safranin O/Fast Green staining after respective culture in adipo-, osteo-, and chondrogenic media. Based on these outcome measures, PDCs exhibited proliferation rate, morphology, surface receptor expression, and multipotency similar to those of BMSCs. No significant correlation was observed between outcome measures and donor age or diagnosis (osteoarthritis [OA] and rheumatoid arthritis [RA], respectively), a profound finding given recent rheumatological studies indicating that OA and RA share not only common biomarkers and molecular mechanisms but also common pathophysiology, ultimately resulting in the need for joint replacement. Furthermore, PDCs isolated via enzymatic digestion and migration assay showed subtle differences in surface marker expression but otherwise no significant differences in proliferation or multipotency; the observed differences in surface marker expression may indicate potential effects of isolation method on the population of cells isolated and/or the behavior of the respective isolated cell populations. This study demonstrates, for the first time to our knowledge, the feasibility of using arthritic tissue resected during hip replacement as a source of autologous stem cells. In sum, periosteum tissue that is resected with the femoral neck in replacing the hip represents an unprecedented and, to date, unstudied source of stem cells from OA and RA patients. Follow-up studies will determine the degree to which this new, autologous source of stem cells can be banked for future use.

Sequential sub-passage decreases the differentiation potential of canine adipose-derived mesenchymal stem cells

Adipose-derived mesenchymal stem cells (AD-MSCs) are abundant in adipose tissue from animals of all ages, are easily isolated, can differentiate into multi-lineage cells, and have a clinical application. This promising potential may only be achieved if the cells are expanding in a large number while maintaining their stemness in sequential passages. In this study, canine AD-MSCs (cAD-MSCs) were individually isolated from five dogs and subjected to proliferative culture with seven sub-passages. The cells at each sub-passage were characterized for properties associated with multipotent MSCs such as proliferation kinetics, expression of MSCs-specific surface markers, expression of molecules associated with self-renewal and differentiation capabilities into mesodermal lineage cells. Proliferation of the cells plateaued at passage 5 by cumulative population doubling level, while cell doubling time gradually increased with passage. MSCs surface markers (CD44, CD90, and CD105) and molecules (Oct 3/4, Sox-2, Nanog and HMGA2) associated with self-renewal were all expressed in the cells between passages 1 to 6 by RT-PCR. In addition, the cells at passage 1, 3 or 6 underwent adipogenic and chondrogenic differentiation under specific induction conditions. However, the level of adipogenic and chondrogenic differentiation was negatively correlated with the number of sub-passage. The present study suggests that sequential sub-passages affect multipotent properties of cAD-MSCs, which should be considered in their therapeutic application in regenerative medicine.

Mesenchymal stromal cells from unconventional model organisms

Mesenchymal stromal cells (MSCs) are multipotent, plastic, adherent cells able to differentiate into osteoblasts, chondroblasts and adipocytes. MSCs can be isolated from many different body compartments of adult and fetal individuals. The most commonly studied MSCs are isolated from humans, mice and rats. However, studies are also being conducted with the use of MSCs that originate from different model organisms, such as cats, dogs, guinea pigs, ducks, chickens, buffalo, cattle, sheep, goats, horses, rabbits and pigs. MSCs derived from unconventional model organisms all present classic fibroblast-like morphology, the expression of MSC-associated cell surface markers such as CD44, CD73, CD90 and CD105 and the absence of CD34 and CD45. Moreover, these MSCs have the ability to differentiate into osteoblasts, chondroblasts and adipocytes. The MSCs isolated from unconventional model organisms are being studied for their potential to heal different tissue defects and injuries and for the development of scaffold compositions that improve the proliferation and differentiation of MSCs for tissue engineering.

Expression of surface markers and myogenic potential of rat bone marrow- and adipose-derived stem cells: a comparative study

In recent years, examination and comparison of the biological characteristics of bone marrow- and adipose-derived mesenchymal stem cells (MSCs) from various perspectives have come into the focus of stem cell research, as these cells should be well characterized in order to utilize them in future cellular therapies. Therefore, in the present study, surface protein markers and the skeletal myogenic differentiation potential of rat bone marrow- and adipose-derived MSCs were examined. The expression of CD44, CD45, CD73, and CD90 on bone marrow- and adipose-derived MSCs was characterized using flow cytometry. Subsequently, the stem cells were differentiated into myogenic lineages, and the expression of the skeletal myogenic markers MyoD1, Myog, and Myh2 was studied in cells using real time polymerase chain reaction and immunofluorescence. Our results reveal that the pattern of CD marker expression differs between these 2 types of MSCs to some extent, whereas no significant difference was observed with respect to their myogenic differentiation potential. Therefore, we concluded that despite the differences observed in the biological features of these 2 types of MSCs, their myogenic potential appears to be similar, and that adipose-derived stem cells may be useful in skeletal muscle tissue engineering, due to their easy isolation and capacity for rapid expansion in a short time span.

Regeneration of articular cartilage by adipose tissue derived mesenchymal stem cells: perspectives from stem cell biology and molecular medicine

Adipose-derived stem cells (ASCs) have been discovered for more than a decade. Due to the large numbers of cells that can be harvested with relatively little donor morbidity, they are considered to be an attractive alternative to bone marrow derived mesenchymal stem cells. Consequently, isolation and differentiation of ASCs draw great attention in the research of tissue engineering and regenerative medicine. Cartilage defects cause big therapeutic problems because of their low self-repair capacity. Application of ASCs in cartilage regeneration gives hope to treat cartilage defects with autologous stem cells. In recent years, a lot of studies have been performed to test the possibility of using ASCs to re-construct damaged cartilage tissue. In this article, we have reviewed the most up-to-date articles utilizing ASCs for cartilage regeneration in basic and translational research. Our topic covers differentiation of adipose tissue derived mesenchymal stem cells into chondrocytes, increased cartilage formation by co-culture of ASCs with chondrocytes and enhancing chondrogenic differentiation of ASCs by gene manipulation.

Advanced Strategies for Articular Cartilage Defect Repair

Articular cartilage is a unique tissue owing to its ability to withstand repetitive compressive stress throughout an individual's lifetime. However, its major limitation is the inability to heal even the most minor injuries. There still remains an inherent lack of strategies that stimulate hyaline-like articular cartilage growth with appropriate functional properties. Recent scientific advances in tissue engineering have made significant steps towards development of constructs for articular cartilage repair. In particular, research has shown the potential of biomaterial physico-chemical properties significantly influencing the proliferation, differentiation and matrix deposition by progenitor cells. Accordingly, this highlights the potential of using such properties to direct the lineage towards which such cells follow. Moreover, the use of soluble growth factors to enhance the bioactivity and regenerative capacity of biomaterials has recently been adopted by researchers in the field of tissue engineering. In addition, gene therapy is a growing area that has found noteworthy use in tissue engineering partly due to the potential to overcome some drawbacks associated with current growth factor delivery systems. In this context, such advanced strategies in biomaterial science, cell-based and growth factor-based therapies that have been employed in the restoration and repair of damaged articular cartilage will be the focus of this review article.

Novel aspects of parenchymal-mesenchymal interactions: from cell types to molecules and beyond

Mesenchymal stem or stromal cells (MSCs) were initially isolated from the bone marrow and received their name on the basis of their ability to differentiate into multiple lineages such as bone, cartilage, fat and muscle. However, more recent studies suggest that MSCs residing in perivascular compartments of the small and large blood vessels play a regulatory function supporting physiologic and pathologic responses of parenchymal cells, which define the functional representation of an organ or tissue. MSCs secrete or express factors that reach neighbouring parenchymal cells via either a paracrine effect or a direct cell-to-cell interaction promoting functional activity, survival and proliferation of the parenchymal cells. Previous concept of 'epithelial-stromal' interactions can now be widened. Given that MSC can also support hematopoietic, neuronal and other non-epithelial parenchymal lineages, terms 'parenchymal-stromal' or 'parenchymal-mesenchymal' interactions may better describe the supportive or 'trophic' functions of MSC. Importantly, in many cases, MSCs specifically provide supportive microenvironment for the most primitive stem or progenitor populations and therefore can play a role as 'stem/progenitor niche' forming cells. So far, regulatory roles of MSCs have been reported in many tissues. In this review article, we summarize the latest studies that focused on the supportive function of MSC. This thread of research leads to a new perspective on the interactions between parenchymal and mesenchymal cells and justifies a principally novel approach for regenerative medicine based on co-application of MSC and parenchymal cell for the most efficient tissue repair.

Isolation and characterization of antler-derived multipotent stem cells

Recent studies have reported that stem cells can be isolated from various tissues such as bone marrow, fatty tissue, umbilical cord blood, Wharton's jelly, and placenta. These types of stem cell studies have also arisen in veterinary medicine. Deer antlers show a seasonal regrowth of tissue, an unusual feature in mammals. Antler tissue therefore might offer a source of stem cells. To explore the possibility of stem cell populations within deer antlers, we isolated and successfully cultured antler-derived multipotent stem cells (MSCs). Antler MSCs were maintained in a growth medium, and the proliferation potential was measured via an assay called the cumulative population doubling level. Immunophenotyping and immunostaining revealed the intrinsic characteristic stem cell markers of antler MSCs. To confirm the ability to differentiate, we conducted osteogenic, adipogenic, and chondrogenic induction under the respective differentiation conditions. We discovered that antler MSCs have the ability to differentiate into multiple lineages. In conclusion, our results show that deer antler tissue may contain MSCs and therefore may be a potential source for veterinary regenerative therapeutics.

The role of steroids in mesenchymal stem cell differentiation: molecular and clinical perspectives

Mesenchymal stem cells (MSCs) are multipotent stem cells capable of either self-regeneration or differentiation into more mature cell types, depending on the environmental stimuli. MSCs originate from the mesoderm and differentiate readily into mesodermal tissue. The tissues most studied in that respect are bone, fat and cartilage, and the key molecular elements in these three differentiation pathways are RUNX2, PPARγ and SOX9, respectively. Steroidal molecules play an important role in determining the fate of MSCs, mainly by altering the expression of key cellular molecules. Not all steroids exert the same effects on these cells. This review discusses the effects of sex steroids and glucocorticoids on the proliferative capacity and differentiation patterns of MSCs. With stem-cell-based therapy gaining worldwide attention, we explore the role of steroids in modulating MSCs for clinical and therapeutic purposes. The ease with which some MSCs, such as adipose-derived stem cells, can be harvested from the body and manipulated in the laboratory may lead to increased interest in this era of stem cells.