Table 4

Older cartilage demonstrated reduced expression of many important cartilage genes compared with young cartilage.

Gene class

Gene name

Gene symbol

Log2 fold-change

Q value


DGE higher in old

ECM

Collagen, type X, alpha 1

COL10A1

-1.40

3.09 × 10-2

Collagen, type XXV, alpha 1

COL25A1

-2.78

3.62 × 10-4

Lubricin

CSPG4

-2.25

2.53 × 10-5

Growth factor/cytokine

Fibroblast growth factor 9

FGF9

-3.33

4.16 × 10-4

DGE lower in old

Protease

A disintegrin and metallopeptidase with thrombospondin 12

ADAMTS12

2.20

2.31 × 10-2

A disintegrin and metallopeptidase with thrombospondin 2

ADAMTS2

5.41

1.43 × 10-11

A disintegrin and metallopeptidase with thrombospondin 4

ADAMTS4

1.94

8.47 × 10-4

Matrix metallopeptidase 1

MMP1

1.67

6.00 × 10-3

Matrix metallopeptidase 13

MMP13

2.01

3.07 × 10-4

Plasminogen activator inhibitor-1

SERPINE1

4.24

4.04 × 10-16

Plasminogen activator, tissue

PLAT

1.86

4.19 × 10-3

Matrix enzyme

Chondroitin sulfate synthase 3

CHSY3

1.54

2.10 × 10-2

Hyaluronan synthase 3

HAS3

1.64

1.65 × 10-2

Procollagen C-endopeptidase enhancer

PCOLCE

1.90

1.89 × 10-3

ECM

Asporin

ASPN

1.55

2.72 × 10-2

Biglycan

BGN

1.47

2.25 × 10-2

Cartilage intermediate layer protein 2

CILP2

4.92

5.97 × 10-19

Chondroadherin

CHAD

2.55

7.89 × 10-6

Collagen alpha 1(V) chain

COL5A1

3.32

9.05 × 10-11

Collagen, type I, alpha 1

COL1A1

6.55

1.49 × 10-28

Collagen, type I, alpha 2

COL1A2

5.57

4.45 × 10-25

Collagen, type II, alpha 1

COL2A1

6.53

1.29 × 10-32

Collagen, type III, alpha 1

COL3A1

5.11

1.04 × 10-22

Collagen, type IV, alpha 1

COL4A1

30.11

6.16 × 10-3

Collagen, type IV, alpha 5

COL4A5

4.07

2.76 × 10-6

Collagen, type IX, alpha 1

COL9A1

8.02

9.70 × 10-32

Collagen, type IX, alpha 2

COL9A2

4.04

2.47 × 10-15

Collagen, type VIII, alpha 1

COL8A1

3.66

3.79 × 10-10

Collagen, type XI, alpha 1

COL11A1

2.01

2.79 × 10-4

Collagen, type XII, alpha 1

COL12A1

1.68

5.11 × 10-3

Collagen, type XIII, alpha 1

COL13A1

4.14

1.23 × 10-4

Collagen, type XIV, alpha 1

COL14A1

3.66

9.07 × 10-13

Collagen, type XV, alpha 1

COL15A1

2.21

7.11 × 10-5

Collagen, type XVI, alpha 1

COL16A1

2.33

1.28 × 10-5

Fibulin 1

FBLN1

4.83

4.44 × 10-9

Fibulin-7

FBLN7

1.66

1.69 × 10-2

Matrilin 2

MATN2

4.56

3.95 × 10-17

Matrilin 4

MATN4

3.69

6.65 × 10-8

Procollagen V, alpha 2

COL5A2

4.03

2.69 × 10-15

Thrombospondin 2

THBS22

2.41

1.26 × 10-4

Thrombospondin 3

THBS3

2.10

1.54 × 10-4

Growth factor/cytokine

Fibroblast growth factor 12

FGF12

2.34

1.55 × 10-2

Interleukin-11

IL11

1.48

2.46 × 10-2

Interleukin-8

IL8

1.65

1.41 × 10-2

Interleukin-1b

IL1B

6.26

8.91 × 10-10

Tumour necrosis factor, alpha-induced protein 3

TNFAIP3

1.73

1.49 × 10-2


The table illustrates significant differential gene expression (DGE) in young and old cartilage of important cartilage, extracellular matrix (ECM), cytokines and growth factors, proteases (causing cartilage degradation) and matrix enzymes (involved in matrix synthesis). Significance was set at P < 0.05 and ± 1.4 log2 fold-change in gene expression based on mapped reads following normalisation and statistical testing in edgeR [24].

Peffers et al. Arthritis Research & Therapy 2013 15:R98   doi:10.1186/ar4278

Open Data