Differentiation of human mesenchymal stem cells and articular chondrocytes: analysis of chondrogenic potential and expression pattern of differentiation-related transcription factors.

• Mesenchymal stem cells (MSCs) are a candidate for replacing chondrocytes in cell-based repair of cartilage lesions. However, it has not been clarified if these cells can acquire the hyaline phenotype, and whether chondrocytes and MSCs show the same expression patterns of critical control genes in development. In order to study this, articular chondrocytes and iliac crest derived MSCs were allowed to differentiate in pellet mass cultures. Gene expression of markers for the cartilage phenotype, helix-loop-helix (HLH) transcription factors, and chondrogenic transcription factors were analyzed by real-time PCR. Matrix production was assayed using biochemical analysis for hydroxyproline, glycosaminoglycans, and immunohistochemistry for collagen types I and II. Significantly decreased expression of collagen type I was accompanied by increased expression of collagen types IIA and IIB during differentiation of chondrocytes, indicating differentiation towards a hyaline phenotype. Chondrogenesis in MSCs on the other hand resulted in up-regulation of collagen types I, IIA, IIB, and X, demonstrating differentiation towards cartilage of a mixed phenotype. Expression of HES1 increased significantly during chondrogenesis in chondrocytes while expression in MSCs was maintained at a low level. The HLH gene HES5 on the other hand was only detected in chondrocytes. Expression of ID1 decreased significantly in chondrocytes while the opposite was seen in MSCs. These findings suggest that chondrocytes and MSCs differentiated and formed different subtypes of cartilage, the hyaline and a mixed cartilage phenotype, respectively. Differentially regulated HLH genes indicated the possibility for HLH proteins in regulating chondrogenic differentiation. This information is important to understand the potential use of MSCs in cartilage repair.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Kirurgi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Surgery (hsv//eng)

Nyckelord

Adult

Basic Helix-Loop-Helix Transcription Factors

genetics

metabolism

Cell Differentiation

genetics

physiology

Cells

Cultured

Chondrocytes

cytology

physiology

Chondrogenesis

genetics

physiology

Collagen Type I

genetics

metabolism

Collagen Type X

genetics

metabolism

Flow Cytometry

methods

Gene Expression Regulation

physiology

Helix-Loop-Helix Motifs

genetics

Homeodomain Proteins

genetics

metabolism

Humans

Immunohistochemistry

methods

Inhibitor of Differentiation Protein 1

genetics

metabolism

Mesenchymal Stem Cells

cytology

physiology

Middle Aged

Repressor Proteins

genetics

metabolism

Reverse Transcriptase Polymerase Chain Reaction

Transcription Factors

genetics

metabolism

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)