Cell Polarity in the Anulus of the Human Intervertebral Disc: Morphologic, Immunocytochemical, and Molecular Evidence.

Gruber, Helen E.;   Ingram, Jane;  Hoelscher, Gretchen L.;  Norton, H James;  Hanley, Edward N.

The objective of this stucy was to determine if there is morphologic and molecular evidence for polarity in cells of the human anulus.  Human disc specimens from donor and surgical patients were examined with light and electron microscopy to assess morphology. Specimens were examined for immunocytochemical localization of PAR3 and claudin-1 and -11, recognized polarity proteins, and additional anulus specimens were examined for expression of polarity-related genes using microarray analysis.  At the macroscopic level, the characteristic anular lamellar morphology implies a specialized architectural formation and organization, which is achieved by the tissue-specific function of polarized cells. Morphologic and molecular studies provided evidence for the presence of polarity in cells in the anulus. These findings advance our understanding of anulus disc cell function in production of highly aligned collagen fibrils and macroaggregates of these collagen fibrils into lamellar collagen bundles. Such disc cell activity is important in development and maintenance of the tissue-specific extracellular matrix of the disc.

Spine, 2007, 32, 12, 1287-1294.

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