Suppression of Injury-Induced Conjunctiva Scarring by Peroxisome Proliferator-Activated Receptor Gene Transfer in Mice (original) (raw)
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Modulating conjunctival wound healing
Eye (London, England), 2000
Advances in molecular and cell biology have led to an expansion in our knowledge and understanding of the processes involved in wound healing. We review existing and potential therapies modulating the conjunctival scarring response, with particular reference to glaucoma filtration surgery. We discuss how the refinement of present antimetabolite regimens can minimise complications and improve surgical results, and advocate their use in carefully selected patient groups. Perhaps the most promising approach is targeting biological molecules. Hence, use of fully human neutralising monoclonal antibodies to the growth factor TGFf3 has potential as a useful strategy for modifying conjunctival scarring. Combination therapies may also afford an improved therapeutic index. It is hoped that future therapies can offer safer, more specific, focal and titratable treatment, with far-reaching clinical applications.
PURPOSE. Connective tissue growth factor (CTGF) has been linked to fibrosis in several tissues. In this study, the interactions between CTGF and transforming growth factor (TGF)- were assessed in human corneal fibroblasts, and the levels and location of CTGF protein and mRNA were measured during healing of excimer laser ablation wounds in rat corneas. METHODS. Human corneal fibroblasts were incubated with TGF-1, -2, and -3 isoforms, and CTGF mRNA and protein were measured. CTGF was immunolocalized in the cultured fibroblasts by using a specific antibody. Regulation of collagen synthesis by TGF- and CTGF was assessed in human corneal fibroblasts with a neutralizing antibody and an antisense oligonucleotide to CTGF. CTGF mRNA and protein were measured in rat corneas up to day 21 after excimer ablation of the cornea. CTGF protein was immunolocalized in rat corneas after photorefractive keratectomy (PRK), and the presence of CTGF mRNA and protein in ex vivo rat corneal scrapings was established. RESULTS. All three TGF- isoforms stimulated expression of CTGF in human corneal fibroblasts, and CTGF was immunolocalized in the cells. Both TGF- and CTGF increased collagen synthesis in corneal fibroblasts. Furthermore, CTGF antibody or antisense oligonucleotide blocked TGF--stimulated collagen synthesis. CTGF protein and mRNA increased in rat corneas through day 21 after PRK. CTGF expression was also detected in ex vivo scrapings of rat corneas. CONCLUSIONS. These data demonstrate that CTGF is expressed by corneal cells after stimulation by TGF-, that CTGF expression increases significantly during corneal wound healing, and that CTGF mediates the effects of TGF- induction of collagen synthesis by corneal fibroblasts. These data support the hypothesis that CTGF promotes corneal scar formation and imply that regulating CTGF synthesis and action may be an important goal for reducing corneal scarring. (Invest Ophthalmol Vis Sci.
Clinical <html_ent glyph="@amp;" ascii="&"/> Experimental Allergy, 2005
Background Nerve growth factor (NGF) and nerve growth factor receptor (NGFR) expressions have been found to be increased in sub-conjunctival scarring. Objective The aim of this study was to investigate the in vitro effects of NGF on some profibrogenic properties of human conjunctival fibroblasts. Methods Expression of NGF, trkA NGFR and p75 NTR on human fibroblasts grown from conjunctival biopsies and incubated for 2 or 6 days with NGF were evaluated by immunofluorescence, RT-PCR, flow cytometry and ELISA. The fibrogenic effect of NGF on conjunctival fibroblasts was investigated by evaluating their migration (wound model), proliferation ([ 3 H]-thymidine incorporation), collagen production (3 H]-proline incorporation), expression of alpha-smooth muscle actin (a-SMA) (cell surface ELISA) and contraction of 3D collagen gels. Results NGF induced the expression of p75 NTR in the fibroblasts that constitutively expressed only trkA NGF and increased the migration of wounded fibroblasts, but not their proliferation and collagen production. NGF induced the conversion of fibroblasts into myofibroblasts expressing a-SMA, and enhanced their contraction of a collagen matrix. Interestingly, chronic NGF treatment induced transforming growth factor-b1 (TGF-b1) production by fibroblasts, and following specific TGF-b neutralization, all the NGF-induced effects were completely abrogated. Conclusion Our findings indicate that NGF, via TGF-b induction, is likely to be involved in the healing or fibrotic processes occurring in conjunctiva during some pathological conditions.
Growth factors and ocular wound healing
Eye, 1994
Protein growth factors regulate many of the processes in vitro that are essential for the process of normal ocular wound healing, including migration, mitosis and differ entiation of cells. This has led to the hypothesis that pep tide growth factors play key roles in regulating normal ocular wound healing in vivo. A corollary to this concept is that insufficient action of growth factors causes impaired healing, and prolonged action of growth factors produces excessive scarring. If both of these concepts are correct, then the addition of exogenous protein growth factors should enhance healing of chronic ocular wounds and reducing prolonged actions of growth factors should limit excessive scarring. Although much remains to be understood about the role of growth factors in ocular development and wound healing, results of a substantial number of laboratory and clinical experiments indicate that these hypotheses are generally correct. This article reviews the results of pre-clinical experiments and clini cal trials investigating the roles of protein growth factors in ocular development and wound healing.
Transforming growth factor-?1 expression in cultured corneal fibroblasts in response to injury
Journal of Cellular Biochemistry, 2000
Aims: To evaluate the expression of transforming growth factor β1 (TGF-β1) and fibroblast growth factor 2 (FGF-2) mRNA in stromal cells in response to injury in the presence of either TGF-β1 or FGF-2. It has been shown previously that heparan sulfate proteoglycans and FGF-2 are present transiently during wound repair in vivo and that an increase in TGF-β1 mRNA is detected rapidly after injury. Methods: Primary corneal fibroblasts were cultured to confluency, serum starved, and linear wound(s) were made in medium containing TGF-β1 or FGF-2. TGF-β1 and FGF-2 mRNA expression were evaluated using both northern blot analysis and in situ hybridisation. Both dose dependent and time course experiments were performed. Whole eye organ culture experiments were also carried out and growth factor expression was assessed.
Gene transfer of Smad7 modulates injury-induced conjunctival wound healing in mice
2006
PURPOSE Smad7 is a molecule that blocks the Smad2/3 signal. Herein, we examined the effects of Smad7 gene introduction on post-injury conjunctival wound healing in mice. Its effects on the cultured human subconjunctival fibroblasts (SCFs) were also investigated. METHODS A circumferential incision was made in the equatorial conjunctiva by using scissors in the right eye of fully anesthetized adult C57BL/6 mice (n=72). Smad7 cDNA-expressing adenoviral vector was topically applied. The control eye received nonfunctioning adenoviral vector. After 2, 5, 7, and 30 days the eyes were processed for histological or immunohistochemical examination to evaluate wound healing of conjunctiva. The expressions of type-I collagen and growth factors were evaluated by real time-reverse transcriptase-polymerase chain reaction. The effects of Smad7 gene introduction on the cultured human SCFs were also studied. RESULTS Marked Smad7 protein expression was detected in the vector-treated conjunctival epith...
Bali Medical Journal, 2022
Background: Conjunctiva, when injured, can heal spontaneously. However, in extensive wounds, wound healing is often accompanied by scarring and wound contraction. Currently, for cases of disease and trauma to the surface of the eyeball, it can be reconstructed using the amniotic membrane, but there are still weaknesses in the use of amnion. Platelet-rich fibrin (PRF) is currently being developed for the reconstruction of ocular surface wounds. Methods: A total of 20 male New Zealand rabbits (20 eyes) were divided into two groups. In the first group, conjunctival excision and PRF membrane graft suturing were performed on the right eye conjunctival defect, while the second group had an amniotic membrane sutured on the right eye conjunctival defect. On the 14 th day, enucleation was carried out and continued with histopathological examination using immunohistochemistry using TGF antibodies and type 1 collagen to evaluate the levels of TGF and type 1 collagen in the conjunctiva. Results: The results after 14 days of treatment showed that there was a very significant difference in TGF Beta expression between the AMT group and the PRF group (p = 0.007*; <0.05). However, in the expression of type 1 collagen, there was no significant difference in the expression of type 1 collagen between the AMT group and the PRF group (p = 0.791; >0.05). Conclusion: There were differences in the expression of TGF-β and type 1 collagen in the administration of the PRF membrane compared to the administration of the amniotic membrane after conjunctival excision of experimental male New Zealand rabbits on day 14.