Marín-Llera Jessica Cristina, García-García Damián, Garay-Pacheco Estefania, Adrian Cortes-Morales Victor, Montesinos-Montesinos Juan Jose, Chimal-Monroy Jesus
Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Coyoacan 04510, Mexico.
Laboratorio de Células Troncales Mesenquimales, Unidad de Investigación Médica en Enfermedades Oncológicas, Hospital de Oncología Centro Medico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City 06720, Mexico.
World J Stem Cells. 2023 Jul 26;15(7):701-712. doi: 10.4252/wjsc.v15.i7.701.
Mesenchymal stromal cells (MSCs) are multipotent cell populations obtained from fetal and adult tissues. They share some characteristics with limb bud mesodermal cells such as differentiation potential into osteogenic, chondrogenic, and tenogenic lineages and an embryonic mesodermal origin. Although MSCs differentiate into skeletal-related lineages , they have not been shown to self-organize into complex skeletal structures or connective tissues, as in the limb. In this work, we demonstrate that the expression of molecular markers to commit MSCs to skeletal lineages is not sufficient to generate skeletal elements .
To evaluate the potential of MSCs to differentiate into skeletal lineages and generate complex skeletal structures using the recombinant limb (RL) system.
We used the experimental system of RLs from dissociated-reaggregated human placenta (PL) and umbilical cord blood (UCB) MSCs. After being harvested and reaggregated in a pellet, cultured cells were introduced into an ectodermal cover obtained from an early chicken limb bud. Next, this filled ectoderm was grafted into the back of a donor chick embryo. Under these conditions, the cells received and responded to the ectoderm's embryonic signals in a spatiotemporal manner to differentiate and pattern into skeletal elements. Their response to differentiation and morphogenetic signals was evaluated by quantitative polymerase chain reaction, histology, immunofluorescence, scanning electron microscopy, and hybridization.
We found that human PL-MSCs and UCB-MSCs constituting the RLs expressed chondrogenic, osteogenic, and tenogenic molecular markers while differentially committing into limb lineages but could not generate complex structures . MSCs-RL from PL or UCB were committed early to chondrogenic lineage. Nevertheless, the UCB-RL osteogenic commitment was favored, although preferentially to a tenogenic cell fate. These findings suggest that the commitment of MSCs to differentiate into skeletal lineages differs according to the source and is independent of their capacity to generate skeletal elements or connective tissue . Our results suggest that the failure to form skeletal structures may be due to the intrinsic characteristics of MSCs. Thus, it is necessary to thoroughly evaluate the biological aspects of MSCs and how they respond to morphogenetic signals in an context.
PL-MSCs and UCB-MSCs express molecular markers of differentiation into skeletal lineages, but they are not sufficient to generate complex skeletal structures .
间充质基质细胞（MSCs）是从胎儿和成人组织中获得的多能细胞群体。它们与肢芽中胚层细胞具有一些共同特征，例如具有分化为成骨、软骨生成和肌腱生成谱系的潜力以及胚胎中胚层起源。尽管MSCs可分化为与骨骼相关的谱系，但它们尚未像在肢体中那样自组织形成复杂的骨骼结构或结缔组织。在这项研究中，我们证明使MSCs定向分化为骨骼谱系的分子标志物的表达不足以生成骨骼成分。
使用重组肢体（RL）系统评估MSCs分化为骨骼谱系并生成复杂骨骼结构的潜力。
我们使用了来自解离后重新聚集的人胎盘（PL）和脐带血（UCB）MSCs的RL实验系统。收获细胞并在沉淀中重新聚集后，将培养的细胞引入从早期鸡肢芽获得的外胚层覆盖物中。接下来，将这个填充有细胞的外胚层移植到供体鸡胚的背部。在这些条件下，细胞以时空方式接收并响应外胚层的胚胎信号，从而分化并形成骨骼成分的模式。通过定量聚合酶链反应、组织学、免疫荧光、扫描电子显微镜和杂交技术评估它们对分化和形态发生信号的反应。
我们发现构成RLs的人PL-MSCs和UCB-MSCs表达软骨生成、成骨和肌腱生成的分子标志物，同时在不同程度上定向分化为肢体谱系，但无法生成复杂结构。来自PL或UCB的MSCs-RL早期定向分化为软骨生成谱系。然而，UCB-RL的成骨定向更受青睐，尽管优先倾向于肌腱生成细胞命运。这些发现表明，MSCs定向分化为骨骼谱系的情况因来源而异，并且与其生成骨骼成分或结缔组织的能力无关。我们的结果表明，未能形成骨骼结构可能是由于MSCs的内在特性。因此，有必要全面评估MSCs的生物学特性以及它们在特定环境中对形态发生信号的反应方式。
PL-MSCs和UCB-MSCs表达分化为骨骼谱系的分子标志物，但它们不足以生成复杂的骨骼结构。
