The Role of c-Jun N-terminal Kinases 1/2 in Transforming Growth Factor β 1 -induced Expression of Connective Tissue Growth Factor and Scar Formation in the Cornea

Abstract

Transforming growth factor β₁ (TGF-β₁) plays an important role in corneal scar formation, mediated by connective tissue growth factor (CTGF). This study was designed to investigate the effect of c-Jun N-terminal kinase (JNK) 1 and 2 on TGF-β₁-regulated CTGF gene expression and corneal scar formation in telomerase-immortalized human corneal stroma fibroblast (THSF) cells. The effects of CTGF, TGF-β₁ and a JNK inhibitor (SP600125) on the proliferation of THSF cells were studied using the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Both CTGF and TGF-β₁ increased THSF cell proliferation and SP600125 inhibited this effect. Immunofluorescence analysis showed that TGF-β₁ stimulated the activation of JNK1/2 and induced cell migration, effects that were inhibited by SP600125. Analysis by real-time reverse transcription–polymerase chain reaction showed that the mRNA levels of the genes for CTGF, fibronectin and collagen Iα₁ in wound and corneal scar formation were reduced by SP600125 pre-treatment.

Keywords

Corneal cells Wound c-Jun N-terminal kinase Connective tissue growth factor Gene expression

References

Munoz

West

: Blindness and visual impairment in the Americas and the Caribbean. Br J Ophthalmol 2002; 86: 498–504.

Netto

Mohan

Ambrosio

: Wound healing in the cornea: A review of refractive surgery complications and new prospects for therapy. Cornea 2005; 24: 509–522.

Schnaper

Hayashida

Hubchak

: TGF-β signal transduction and mesangial cell fibrogenesis. Am J Physiol Renal Physiol 2003; 284: F243–F252.

Brigstock

: The connective tissue growth factor/cysteine-rich 61/nephroblastoma overexpressed (CCN) family. Endocr Rev 1999; 20: 189–206.

Frazier

Williams

Kothapalli

: Stimulation of fibroblast cell growth, matrix production and granulation tissue formation by connective tissue growth factor. J Invest Dermatol 1996; 107: 404–411.

Yang

Guo

: The role of connective tissue growth factor, transforming growth factor β1 and Smad signaling pathway in corneal wound healing. Chin Med J (Engl) 2006; 119: 57–62.

Igarashi

Okochi

Bradham

: Regulation of connective tissue growth factor gene expression in human skin fibroblasts and during wound repair. Mol Biol Cell 1993; 4: 637–645.

Blalock

Yuan

Lewin

: Hammerhead ribozyme targeting connective tissue growth factor mRNA blocks transforming growth factor-beta mediated cell proliferation. Exp Eye Res 2004; 78: 1127–1136.

Utsugi

Dobashi

Ishizuka

: C-Jun-NH2-terminal kinase mediates expression of connective tissue growth factor induced by transforming growth factor-β1 in human lung fibroblasts. Am J Respir Cell Mol Biol 2003; 28: 754–761.

10.

Ljubimov

Alba

Burgeson

: Extracellular matrix changes in human corneas after radial keratotomy. Exp Eye Res 1998; 67: 265–272.

11.

Andrew

: TGFβ, cardiac fibroblasts, and the fibrotic response. Cardiovasc Res 2007; 74: 207–212.

12.

Kang

Cho

Lee

: Transforming growth factor (TGF)-β1 stimulates pulmonary fibrosis and inflammation via a Bax-dependent, Bid-activated pathway that involves matrix metalloproteinase-12. J Biol Chem 2007; 282: 7723–7732.

13.

Leask

Abraham

: All in the CCN family: Essential matricellular signaling modulators emerge from the bunker. J Cell Sci 2006; 119: 4803–4810.

14.

Rosette

Karin

: Ultraviolet light and osmotic stress: Activation of the JNK cascade through multiple growth factor and cytokine receptors. Science 1996; 274: 1194–1197.

15.

Kyriakis

Banerjee

Nikolakaki

: The stress-activated protein kinase subfamily of c-Jun kinases. Nature 1994; 69: 156–160.

16.

Chuang

Wang

Yang

: Roles of JNK, p38 and ERK mitogen-activated protein kinases in the growth inhibition and apoptosis induced by cadmium. Carcinogenesis 2000; 21: 1423–1432.

17.

Gururajan

Chui

Karuppannan

: c-Jun N-terminal kinase (JNK) is required for survival and proliferation of B-lymphoma cells. Blood 2005; 106: 1382–1391.

18.

Barr

Boehm

Attwood

: The critical features and the mechanism of inhibition of a kinase interaction motif-based peptide inhibitor of JNK. J Biol Chem 2004; 35: 36327–36338.