» Articles » PMID: 16275928

Molecular Basis for Keratoconus: Lack of TrkA Expression and Its Transcriptional Repression by Sp3

Overview
Specialty Science
Date 2005 Nov 9
PMID 16275928
Citations 15
Authors
Affiliations
Soon will be listed here.
Abstract

Keratoconus is the most common corneal dystrophy that leads to severe visual impairment. Although the major etiological factors are genetic, the pathogenetic mechanism(s) is unknown. No medical treatments exist, and the only therapeutic approach is corneal transplantation. Recent data demonstrate the involvement of nerve growth factor (NGF) in trophism and corneal wound healing. In this study, we investigated alterations in the NGF pathway in keratoconus-affected corneas and found a total absence of the NGF-receptor TrkA (TrkA(NGFR)) expression and a decreased expression of NGF and p75(NTR). The absence of TrkA(NGFR) expression was associated with a strong increase in the Sp3 repressor short isoform(s) and a lack of the Sp3 activator long isoform. Sp3 is a bifunctional transcription factor that has been reported to stimulate or repress the transcription of numerous genes. Indeed, we found that Sp3 short isoform(s) overexpression in cell culture results in a down-regulation of TrkA(NGFR) expression. We suggest that an imbalance in Sp transcription-factor isoforms may play a role in controlling the NGF signaling, thus contributing to the pathogenesis of keratoconus. This mechanism for the transcriptional repression of the TrkA(NGFR) gene can provide the platform for the development of a therapeutic strategy.

Citing Articles

Level of Secretion and the Role of the Nerve Growth Factor in Patients with Keratoconus before and after Collagen Fibre Cross-Linking Surgery.

Krok M, Wroblewska-Czajka E, Lach-Wojnarowicz O, Bronikowska J, Czuba Z, Wylegala E Int J Mol Sci. 2024; 25(1).

PMID: 38203537 PMC: 10779167. DOI: 10.3390/ijms25010366.


Systematically Displaying the Pathogenesis of Keratoconus Multi-Level Related Gene Enrichment-Based Review.

Hao X, Gao H, Xu W, Shan C, Liu Y, Zhou Z Front Med (Lausanne). 2022; 8:770138.

PMID: 35141241 PMC: 8818795. DOI: 10.3389/fmed.2021.770138.


Tear Mediators in Corneal Ectatic Disorders.

Pasztor D, Kolozsvari B, Csutak A, Berta A, Hassan Z, Ujhelyi B PLoS One. 2016; 11(4):e0153186.

PMID: 27074131 PMC: 4830513. DOI: 10.1371/journal.pone.0153186.


Presence of Fleischer ring and prominent corneal nerves in keratoconus relatives and normal controls.

Kriszt A, Losonczy G, Berta A, Takacs L Int J Ophthalmol. 2015; 8(5):922-7.

PMID: 26558202 PMC: 4631017. DOI: 10.3980/j.issn.2222-3959.2015.05.12.


Lacritin and other autophagy associated proteins in ocular surface health.

Karnati R, Talla V, Peterson K, Laurie G Exp Eye Res. 2015; 144:4-13.

PMID: 26318608 PMC: 4698016. DOI: 10.1016/j.exer.2015.08.015.


References
1.
Ruddle J, Mackey D, Downie N . Clinical progression of keratoconus following a Vth nerve palsy. Clin Exp Ophthalmol. 2003; 31(4):363-5. DOI: 10.1046/j.1442-9071.2003.00673.x. View

2.
Brookes N, Loh I, Clover G, Poole C, Sherwin T . Involvement of corneal nerves in the progression of keratoconus. Exp Eye Res. 2003; 77(4):515-24. DOI: 10.1016/s0014-4835(03)00148-9. View

3.
Ghayor C, Chadjichristos C, Herrouin J, Ala-Kokko L, Suske G, Pujol J . Sp3 represses the Sp1-mediated transactivation of the human COL2A1 gene in primary and de-differentiated chondrocytes. J Biol Chem. 2001; 276(40):36881-95. DOI: 10.1074/jbc.M105083200. View

4.
Micera A, Vigneti E, Pickholtz D, Reich R, Pappo O, Bonini S . Nerve growth factor displays stimulatory effects on human skin and lung fibroblasts, demonstrating a direct role for this factor in tissue repair. Proc Natl Acad Sci U S A. 2001; 98(11):6162-7. PMC: 33439. DOI: 10.1073/pnas.101130898. View

5.
Lambiase A, Aloe L, Rama P, Bonini S . Anti-inflammatory and healing properties of nerve growth factor in immune corneal ulcers with stromal melting. Arch Ophthalmol. 2000; 118(10):1446-9. DOI: 10.1001/archopht.118.10.1446. View