Читать книгу Recent Research in Nutrition and Growth - Группа авторов - Страница 20

The long-bone growth plate represents but one example of a time-specific differentiation process. The body grows as a system of interrelated tissues with dynamic interactions involving time-sensitive cellular life histories, with tissue-specific developmental programs interacting through shared progenitor cells. MSCs, for instance, may have the potential to differentiate into mature cells of cartilage (chondrocytes), bone (osteoblasts), and adipose tissue (adipocytes). While the precise mechanisms of these events remain to be articulated, in brief the differentiation of MSCs into these respective musculoskeletal tissues involves two steps: (1) the commitment of MSC progenitors to tissue-specific lineage progenitors and (2) the maturation of lineage progenitors into specific cell types. How these stages unfold depends on the local confluence of chemical, physical, and biological cues during the critical periods in which a tissue is undergoing growth or turnover [29]. In a constant collaborative interaction, systemic factors can shift the local milieu by activating or repressing an array of transcription factors, growth factors, and cytokines within the MSC niche. While the limiting resource for growth is generally viewed to be a direct reflection of energy availability, the allocation of common precursor cells provides another mechanism by which tissue-specific growth cascades may contribute to growth outcomes at the whole-body level.