Yonsei Med J.  2009 Jun;50(3):375-379. 10.3349/ymj.2009.50.3.375.

Phenotypic Characterization of Ligamentum Flavum Cells from Patients with Ossification of Ligamentum Flavum

• Zhong ZM
• Chen JT

• KMID: 1758565
• DOI: http://doi.org/10.3349/ymj.2009.50.3.375

Abstract

PURPOSE: The objective of this study was to determine the phenotypic characterization of ligamentum flavum cells from patients with ossification of the ligamentum flavum (OLF).
MATERIALS AND METHODS
Ligamentum flavum tissues were harvested from OLF and non-OLF patients during surgery. OLF and non-OLF cells were isolated from explant cultures. Cultured cells were analyzed using immunofluorescence staining and reverse transcription-polymerase chain reaction.
RESULTS
OLF cells exhibited various appearances compared with the typical fibroblast-like morphology of non-OLF cells. Expressions of collagen type I and collagen type III were observed in OLF and non-OLF cells. OLF cells uniquely expressed osteocalcin, which is a marker for osteoblasts, and collagen type II which is a marker for chondrocytes, whereas they were negative in non-OLF cells.
CONCLUSION
These findings indicate that OLF cells have phenotypic characterization of osteoblasts and chondrocytes which could play a role in the pathophysiology of OLF.

Keyword

Cell phenotype; ossification; ligamentum flavum

MeSH Terms

Adolescent
Adult
Aged
Cells, Cultured
Collagen Type I/genetics/metabolism
Collagen Type II/genetics/metabolism
Collagen Type VI/genetics/metabolism
Female
Humans
Ligamentum Flavum/metabolism/*pathology
Male
Microscopy, Fluorescence
Middle Aged
Ossification, Heterotopic/metabolism/*pathology
Osteocalcin/genetics/metabolism
Reverse Transcriptase Polymerase Chain Reaction
Young Adult

Figure

• 

  Fig. 1 Histological characterization of the OLF. Ossification (arrowhead) and chondroid cells (arrow) were observed in the ossified ligamentum flavum (hematoxylin and eosin stain, bar = 100 µm).

• 

  Fig. 2 Immunofluorescence analysis of OLF cells and non-OLF cells. Immunofluorescence was visualized using FITC (green) and the nuclei by PI (red). OLF cells expressed osteocalcin, collagen type I, II and III; non-OLF cells expressed collagen type I and III, but not osteocalcin and collagen type II (bar = 20 µm).

• 

  Fig. 3 Gene expression analysis for osteocalcin, collagen type I, collagen type II and collagen type III in OLF cells and non-OLF cells by RT-PCR. Data shown are agarose gel electrophoresis of amplification products.

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