Elkhenany Hoda, Amelse Lisa, Caldwell Marc, Abdelwahed Ramadan, Dhar Madhu
Department of Large Animal Clinical Sciences, University of Tennessee, Knoxville, TN 37996 USA ; Department of Surgery, Faculty of Veterinary Medicine, Alexandria University, Edfina, Behera, 22785 Egypt.
Department of Large Animal Clinical Sciences, University of Tennessee, Knoxville, TN 37996 USA.
J Anim Sci Biotechnol. 2016 Mar 5;7:16. doi: 10.1186/s40104-016-0074-z. eCollection 2016.
Adult mesenchymal stem cells (MSCs) can be conveniently sampled from bone marrow, peripheral blood, muscle, adipose and connective tissue, harvested from various species, including, rodents, dogs, cats, horses, sheep, goats and human beings. The MSCs isolated from adult tissues vary in their morphological and functional properties. These variations are further complicated when cells are expanded by passaging in culture. These differences and changes in MSCs must be considered prior to their application in the clinic or in a basic research study. Goats are commonly used as animal models for bone tissue engineering to test the potential of stem cells for bone regeneration. As a result, goat MSCs isolated from bone marrow or adipose tissue should be evaluated using in vitro assays, prior to their application in a tissue engineering project.
In this study, we compared the stem cell properties of MSCs isolated from goat bone marrow and adipose tissue. We used quantitative and qualitative assays with a focus on osteogenesis, including, colony forming unit, rate of cell proliferation, tri-lineage differentiation and expression profiling of key signal transduction proteins to compare MSCs from low and high passages. Primary cultures generated from each source displayed the stem cell characteristics, with variations in their osteogenic potentials. Most importantly, low passaged bone marrow MSCs displayed a significantly higher and superior osteogenic potential, and hence, will be the preferred choice for bone tissue engineering in future in vivo experiments. In the bone marrow MSCs, this process is potentially mediated by the p38 MAPK pathway. On the other hand, osteogenic differentiation in the adipose tissue MSCs may involve the p44/42 MAPK pathway.
Based on these data, we can conclude that bone marrow and fat-derived MSCs undergo osteogenesis via two distinct signaling pathways. Even though the bone marrow MSCs are the preferred source for bone tissue engineering, the adipose tissue MSCs are an attractive alternative source and undergo osteo-differentiation differently from the bone marrow MSCs and hence, might require a cell-based enhancer/inducer to improve their osteogenic regenerative capacity.
成人间充质干细胞（MSCs）可方便地从骨髓、外周血、肌肉、脂肪和结缔组织中获取，这些组织取自包括啮齿动物、狗、猫、马、绵羊、山羊和人类等多种物种。从成人组织中分离出的间充质干细胞在形态和功能特性上存在差异。当细胞在培养中传代扩增时，这些差异会进一步复杂化。在将间充质干细胞应用于临床或基础研究之前，必须考虑这些差异和变化。山羊通常被用作骨组织工程的动物模型，以测试干细胞促进骨再生的潜力。因此，从山羊骨髓或脂肪组织中分离出的间充质干细胞在应用于组织工程项目之前，应使用体外试验进行评估。
在本研究中，我们比较了从山羊骨髓和脂肪组织中分离出的间充质干细胞的干细胞特性。我们使用了定量和定性分析方法，重点关注成骨作用，包括集落形成单位、细胞增殖率、三系分化以及关键信号转导蛋白的表达谱分析，以比较低代和高代的间充质干细胞。从每个来源获得的原代培养物均表现出干细胞特征，但其成骨潜力存在差异。最重要的是，低代骨髓间充质干细胞表现出显著更高且更优的成骨潜力，因此，在未来的体内实验中，它将是骨组织工程的首选。在骨髓间充质干细胞中，这一过程可能由p38丝裂原活化蛋白激酶（MAPK）途径介导。另一方面，脂肪组织间充质干细胞的成骨分化可能涉及p44/42 MAPK途径。
基于这些数据，我们可以得出结论，骨髓和脂肪来源的间充质干细胞通过两种不同的信号通路进行成骨。尽管骨髓间充质干细胞是骨组织工程的首选来源，但脂肪组织间充质干细胞是一种有吸引力的替代来源，其成骨分化方式与骨髓间充质干细胞不同，因此，可能需要基于细胞的增强剂/诱导剂来提高其成骨再生能力。
