Keloid-derived fibroblasts show increased secretion of factors involved in collagen turnover and depend on matrix metalloproteinase for migration.

BACKGROUND: A keloid is a specific skin lesion that expands beyond the boundaries of the original injury as it heals. Histologically, it is characterized by the excessive accumulation of collagen. However, the reasons for the expansion and the invasive nature of keloids remain unknown. OBJECTIVES: We evaluated collagen degradation and migration by cultured keloid fibroblasts based on the assumption that these variables were of functional relevance to the expanding and invasive nature of keloid lesions. METHODS: Collagen production was investigated by the detection of type 1 collagen (procollagen type 1C peptide: P1P). Matrix metalloproteinase (MMP)-1 (interstitial collagenase) and MMP-2 (gelatinase-A), were investigated as elements of the collagen degradation system. Enzyme immunoassays were performed to measure the production of P1P, MMP-1, MMP-2, and tissue inhibitor of metalloproteinase (TIMP)-1. To assess the production of MMP-2 its gelatinolytic activity was measured by zymography using gelatin-containing gels. The participation of transforming growth factor-beta1 (TGF-beta1) in the production and degradation of collagen was also investigated. Finally, the migratory activity of keloid fibroblasts was evaluated using a colony dispersion assay. RESULTS: The production of type 1 collagen, MMP-1, MMP-2, and TIMP-1 by keloid fibroblasts was 3-fold, 6-fold, 2.4-fold, and 2-fold greater than that of normal dermal fibroblasts, respectively. Production of P1P was increased when TGF-beta1 was added to cultures of keloid fibroblasts, while it was decreased when anti-TGF-beta1 antibody was added to the cultures. In contrast, the production of MMP-1 was decreased by the addition of TGF-beta1 to cultured keloid fibroblasts, while it was increased when anti-TGF-beta1 antibody was added to the cultures. The production of MMP-2 increased after treatment with TGF-beta1, but did not change significantly when anti-TGF-beta1 antibody was added to the cultures. Production of TIMP-1 did not change significantly when either TGF-beta1 or anti-TGF-beta1 antibody was added to the cultures. Keloid fibroblasts showed a 2.5-fold increase of migratory activity compared with normal dermal fibroblasts, while the migratory activity of these fibroblasts was reduced to the control level by treatment with a broad-spectrum MMP inhibitor (GM 6001). CONCLUSIONS: Cultured keloid fibroblasts showed increased production of collagen and MMPs, and TGF-beta1 played a role in this regulation of production. In addition, increased production of MMPs had a role in the high migratory activity of cultured keloid fibroblasts.

TGFbeta-Smad signalling in postoperative human lens epithelial cells.

AIMS: To localise Smads3/4 proteins in lens epithelial cells (LECs) of fresh and postoperative human specimens. Smads3/4 are involved in signal transduction between transforming growth factor beta (TGFbeta) cell surface receptors and gene promoters. Nuclear localisation of Smads indicates achievement of endogenous TGFbeta signalling in cells. METHODS: Three circular sections of the anterior capsule, one lens, and 17 capsules undergoing postoperative healing were studied. Immunohistochemistry was performed for Smads3/4 in paraffin sections of the specimens. The effect of exogenous TGFbeta2 on Smad3 subcellular localisation was examined in explant cultures of extracted human anterior lens epithelium. RESULTS: The cytoplasm, but not the nuclei, of LECs of uninjured lenses was immunoreactive for Smads3/4. In contrast, nuclear immunoreactivity for Smads3/4 was detected in LECs during capsular healing. Nuclei positive for Smads3/4 were observed in monolayered LECs adjacent to the regenerated lens fibres of Sommerring's ring. Interestingly, the nuclei of LECs that were somewhat elongated, and appeared to be differentiating into fibre-like cells, were negative for Smads3/4. Fibroblast-like, spindle-shaped lens cells with nuclear immunoreactivity for nuclear Smads3/4 were occasionally observed in the extracellular matrix accumulated in capsular opacification. Exogenous TGFbeta induced nuclear translocation of Smad3 in LECs of anterior capsule specimens in explant culture. CONCLUSIONS: This is consistent with TGFbeta induced Smad signalling being involved in regulating the behaviour of LECs during wound healing after cataract surgery.

Latent TGFbeta binding protein-1 and fibrillin-1 in human capsular opacification and in cultured lens epithelial cells.

BACKGROUND/AIM: It was previously reported that collagenous extracellular matrix (ECM) in human capsular opacification contained isoforms of transforming growth factor beta (TGFbeta). In the present study, the authors performed immunohistochemistry to examine whether ECM in human capsular opacification and in cultures of bovine lens epithelial cells (LECs) contained latent TGFbeta binding protein-1 (LTBP-1), TGFbeta1 latency associated peptide (beta1-LAP), and fibrillin-1, a suspected ligand of LTBP-1 as well as a component of the extracellular microfibrillar apparatus. The aim of the study was to further clarify the mechanism of TGFbeta1 deposition in ECM of capsular opacification. METHODS: Human capsular opacification specimens and uninjured lens capsules, as well as cultured bovine LECs, were processed for immunohistochemistry using antibodies against LTBP-1, beta1-LAP, fibrillin-1, and collagen type I. RESULTS: LTBP-1, beta1-LAP, and fibrillin-1 all were localised to the ECM in human capsular opacification. Uninjured lens epithelium stained for beta1-LAP, but not for LTBP-1 and fibrillin-1. ECM deposited in confluent LEC cultures stained for LTBP-1, beta1-LAP, and fibrillin-1, while cultures with only sparse cellularity were unstained for LTBP-1 or fibrillin-1. CONCLUSIONS: LECs upregulate LTBP-1 and fibrillin-1 during postoperative healing. LTBP-1, beta1-LAP, and fibrillin-1 colocalised to the ECM in capsular opacification and in confluent LEC cultures. TGFbeta1 is considered to deposit in ECM in the large latent form. ECM secreted by LEC may function as a scavenger or repository of TGFbeta.

Lens epithelial cell regeneration of a capsule-like structure during postoperative healing in rabbits.

PURPOSE: To determine whether lens epithelial cells (LECs) can regenerate the lens capsule during healing after lens extraction and intraocular lens (IOL) implantation. SETTING: Department of Ophthalmology, Wakayama Medical College, Japan. METHODS: Extracapsular lens extraction and IOL implantation were performed in 5 adult albino rabbits. Lens capsules were examined histologically and immunohistochemically 3 and 5 months later. RESULTS: Lens epithelial cells proliferated and regenerated lens fibers within the capsular bag. A multilayered homogenous capsule-like structure was present in the equatorial region. The structures contained type IV collagen but not type I collagen. CONCLUSION: Lens epithelial cells can regenerate lens capsule-like structures during healing after lens extraction. Postoperative LECs without phenotypic conversion to a fibroblastic type may produce this structure.

Decreased type III and V collagen expression in chorionic villi of hydatidiform mole.

To investigate the characteristic structure of hydatidiform mole, various types of collagen expression were determined in human villous tissues obtained from normal pregnancies (n = 17) and complete hydatidiform moles (n = 10). Indirect immunofluorescent staining was performed to detect type I, III, and VI collagen with specific monoclonal antibodies. Collagens were also extracted from the villous tissues obtained from normal pregnancy and hydatidiform mole by the salt precipitation method. Immunohistochemical staining for type I, III, and VI collagen revealed weak staining of the villous stroma in hydatidiform mole compared with that in normal pregnancy. Both the ratios of type III to type I collagen and the ratios of type V to type I collagen in the villous tissues were significantly decreased (P < 0.05) in molar pregnancy compared with those in normal pregnancy. These results suggest that alterations in the distribution and composition of collagen might play an important role in determining the pathophysiology and structure of hydatidiform mole.

Smad translocation and growth suppression in lens epithelial cells by endogenous TGFbeta2 during wound repair.

To determine whether endogenous TGFbeta affects lens epithelial cells during repair after an anterior capsule injury in mice, we studied translocation of Smad proteins, which carry the TGFbeta signal from cell surface receptors to promoters in nuclei. We immunolocalized Smads in murine lenses at intervals up to 8 weeks following capsular injury. Effects of injecting TGFbeta neutralizing antibodies on Smad4 location and cell proliferation were examined at 24 hr after injury. Finally, we examined whether exogenous TGFbeta2 induced Smad nuclear translocation in murine lenses in organ culture. Cell proliferation was quantitated by 5-bromo-2'-deoxyuridine (BrdU) labelling. In uninjured lenses, Smads were located in the cytoplasm. In injured lenses, nuclear localization of Smads was observed in cells next to the capsular break from 8 to 24 hr after the injury, and was observed peripheral to the break at 48 hr. Nuclear Smads then continued to be observed occasionally in a minority of cells. Injection of antibodies neutralizing TGFbeta2, but not TGFbeta1 or TGFbeta3, inhibited Smad4 nuclear translocation and resulted in the appearance of BrdU-positive anterior epithelial cells. With the lenses in culture, transient nuclear localization of Smads occurred between 3 and 24 hr in response to continuous exposure to TGFbeta2. No nuclear translocation was seen at 48 hr. Endogenous TGFbeta2 affects lens cells during wound repair after anterior capsule injury, inhibiting lens cell proliferation during the early phase. Nuclear translocation of Smads in lens epithelial cells is transient even with continuous exposure to TGFbeta2.

Accumulation of latent transforming growth factor-beta binding protein-1 and TGF beta 1 in extracellular matrix of filtering bleb and of cultured human subconjunctival fibroblasts.

PURPOSE: To examine immunohistochemically whether extracellular matrix (ECM) of the filtering bleb and of cultured human subconjunctival fibroblasts contains latent TGF beta binding protein-1 (LTBP-1) and TGF beta. METHODS: An enucleated human eye that had undergone trabeculectomy and cultured human subconjunctival fibroblasts were processed for light microscopic immunohistochemistry. Antibodies against LTBP-1, collagen types, fibrillin-1 and TGF beta s were used. TGF beta 1 was located by detecting beta 1-latency associated peptide (LAP). RESULTS: LTBP-1, beta 1-LAP and fibrillin-1 were all located in the subepithelial ECM as well as in the basal epithelial cells of the conjunctiva over the filtering bleb. TGF beta 2 and beta 3 were immunolocated to epithelium and/or fibroblasts/keratocytes. ECM deposited in confluent fibroblast cultures was positive for beta 1-LAP, LTBP-1 and fibrillin-1, whereas sparse cells were negative. CONCLUSIONS: LTBP-1, beta 1-LAP and fibrillin-1 are co-localized to the ECM of the filtering bleb and of cultured conjunctival fibroblasts. Both conjunctival epithelium and fibroblasts are considered to be the source of TGF beta in healing bleb. ECM secreted by in vivo and in vitro subconjunctival fibroblasts may works as a scavenger or repository of TGF beta.

Overexpression of type IV collagen in chorionic villi in hydatidiform mole.

To investigate the characteristic structure of hydatidiform mole, type IV collagen expression was determined in human villous tissues obtained from normal pregnancies (n = 17) and complete hydatidiform moles (n = 10). Indirect immunofluorescent staining was performed to detect type IV collagen with specific monoclonal antibody, and Northern blot analysis was performed to assess expression of messenger ribonucleic acid for the alpha1(IV) chain. In addition, serum levels of type I, III, and IV collagen were measured by RIA. Immunohistochemical staining for type IV collagen revealed stronger staining of the trophoblastic basement membrane in hydatidiform mole than in normal pregnancy. Northern blot analysis revealed that the villous expression of messenger ribonucleic acid for the alpha1(IV) chain was significantly increased in hydatidiform moles compared with normal pregnancy (P < 0.01). Although there were no differences in the serum type I and III collagen levels between hydatidiform mole and normal pregnancy, the type IV collagen level was significantly higher in patients with hydatidiform mole than in normal pregnancy (P < 0.05). These results suggest that type IV collagen might play an important role in determining the pathophysiology and structure of hydatidiform mole.

Extracellular matrix components in a case of retrocorneal membrane associated with syphilitic interstitial keratitis.

PURPOSE: A web-like retrocorneal membrane (RCM) is an uncommon complication of chronic syphilitic interstitial keratitis. Extracellular matrix components have not yet been defined in this structure, although previous histologic examinations have suggested the presence of collagen. We examined the presence and distribution of extracellular matrix components in a patient with an RCM. METHODS: A specimen of the opaque cornea affected by syphilitic interstitial keratitis with RCM formation was obtained during penetrating keratoplasty in a 62-year-old woman and was evaluated by histology, immunohistochemistry, and scanning electron microscopy (SEM). Antibodies against collagen types I, III, and IV; fibronectin; vimentin; alpha-smooth muscle actin (alpha-SMA); heat shock protein 47 (Hsp 47); proliferating cell nuclear antigen (PCNA); and Ki67 were used. RESULTS: Histologic analysis detected multiple concentric, acellular layers positive for collagen types I, III, and IV. The corneal endothelial cells (CECs) were positive for vimentin, collagen I, fibronectin, and Hsp 47 but not for alpha-SMA. Furthermore, the CECs were negative for PCNA and Ki67, indicating that they were not proliferating. SEM revealed the RCM was covered by CECs with a fibroblastic appearance. CONCLUSION: RCM associated with syphilitic interstitial keratitis contained collagen types I, III, and IV and fibroblast-like CECs. These CECs may secrete the extracellular matrix components found in the RCM. Hsp 47 up-regulation in the CECs may play an important role in RCM formation. These findings provide further insights into the phenotypic modulation of CECs.

Collagens XII and XIV (FACITs) in capsular opacification and in cultured lens epithelial cells.

PURPOSE: We previously reported that extracellular matrix (ECM) accumulation in human capsular opacification included collagen types I, III, IV, V, and VI. To further characterize the ECM in capsular opacification we performed immunohistochemistry to localize collagen types XII and XIV (fibril-associated collagens with interrupted triple helices, or FACITs) in specimens of human capsular opacification and in cultures of bovine lens epithelial cells (LECs). METHODS: Cryosections and paraffin sections of human capsular opacification specimens or uninjured lens capsules, as well as cultured bovine LECs, were processed for immunohistochemistry using antibodies against collagen types I to VI, XII, and XIV. A rat crystalline lens was punctured through the central cornea and the eye was processed for immunohistochemistry for FACITs after healing intervals. RESULTS: In the absence of injury human LECs were unstained for FACITs, but as early as 10 days after operation, LECs in healing capsules were immunoreactive. Collagen types I, III, IV, V, and VI were also detected. ECM deposited in confluent LEC cultures stained for FACITs. Normal rat LECs were not stained for FACITs, but ECM accumulated in injured lens stained for them. CONCLUSIONS: LECs up-regulate FACITs during post-opera-tive healing. FACITs, as well as other collagen types, are deposited in ECM in healing injured rat lens, in human capsular opacification and in LEC cultures. ECM components may regulate LEC behavior during postoperative healing.

Alterations in ultrastructure and c-met expression in a case of ocular epithelial dysplasia following topical mitomycin C treatment.

PURPOSE: Topical mitomycin C (MMC) administration is reportedly effective in treating ocular surface neoplasms such as squamous cell carcinoma. We treated a case of ocular epithelial dysplasia that had spread too diffusely to be completely removed. We examined the ultrastructure of and c-met (hepatocyte growth factor receptor) expression in dysplastic epithelial cells from this case to evaluate the efficacy of MMC treatment. METHODS: Specimens of dysplastic epithelial tissue from the corneo-limbal region of a 62-year-old man were obtained before and after topical application of MMC. Specimens were examined ultrastructurally and immunohistochemically with an antibody against human c-met. RESULTS: Following topical application of MMC, the dysplastic epithelium exhibited multilayered epithelial cells similar to those seen before treatment. However, ultrastructural examination showed tight interdigitation between neighboring cells, with no intercellular spaces. Also, the marked immunoreactivity to c-met in the dysplastic epithelial cells before MMC treatment was decreased after treatment. CONCLUSIONS: Ultrastructural observations indicated a restoration of epithelial cellular differentiation following MMC application. The expression of c-met protein was also reduced. Thus, topical MMC was effective in treating epithelial dysplasia of the ocular surface, with no recurrence 15 months post-therapy.

Type VI collagen expression during growth of human ovarian follicles.

OBJECTIVE: To identify type VI collagen expression in human ovarian follicles during follicular growth. DESIGN: In vitro experiment. SETTING: Department of Obstetrics and Gynecology, Wakayama Medical College, Japan. PATIENT(S): Regularly cycling women who underwent adnexectomy. INTERVENTION(S): Immunohistochemistry and in situ hybridization for human type VI collagen. MAIN OUTCOME MEASURE(S): Expression of type VI collagen. RESULT(S): Expression of type VI collagen was observed in the theca cell layers during folliculogenesis, whereas no expression of type VI collagen was observed in the granulosa cell layers at the mRNA and protein levels. As the follicles grew, immunostaining for type VI collagen became intense in the theca cell layers, especially the theca externa. In preovulatory follicles, however, weak, fragmented, or discontinuous immunostaining of the theca cell layers was observed. This fragmented or discontinuous immunostaining was evident predominantly in the apical area of preovulatory follicles rather than in the basal area. CONCLUSION(S): Type VI collagen is present in the theca cell layers of follicles during folliculogenesis and plays an important role in interactions between the theca cells and extracellular matrix. These interactions may lead to changes in the shape, proliferation, migration, or differentiation of follicular cells during follicular development, maturation, and ovulation.

Transforming growth factor-beta isoform proteins in cell and matrix deposits on intraocular lenses.

PURPOSE: To determine whether the cells that adhere to poly(methyl methacrylate) (PMMA) posterior chamber intraocular lenses (PC IOLs) implanted in human eyes produce transforming growth factor-beta (TGF-beta) isoforms and whether the acellular proteinaceous deposits on these IOLs contain TGF-beta. SETTING: Department of Ophthalmology, Wakayama Medical College, Japan. METHODS: Thirty-two PMMA PC IOLs explanted from Japanese patients were immunostained for TGF-beta1, -beta2, or -beta3, and observed under light microscopy. RESULTS: Cell deposits were observed on 12 IOLs and proteinaceous deposits on 16. Components of the cell deposits were mainly of macrophage origin. The cell and matrix deposits tested positive for each isoform of TGF-beta. CONCLUSION: The cells that adhered to implanted PMMA PC IOLs produced TGF-beta, and the extracellular matrix that accumulated on the surface of the IOLs contained TGF-beta. Transforming growth factor-beta from the cells on IOLs may influence the healing process of residual lens capsules after cataract surgery with IOL implantation.

Immunolocalization of TGF-beta1, -beta2, and -beta3, and TGF-beta receptors in human lens capsules with lens implants.

PURPOSE: To establish the alteration in expression pattern of transforming growth factor (TGF)-betas and their receptors during repair of lens capsules after cataract surgery, we immunohistochemically located TGF-beta isoforms and their receptors in human lens capsules before and after cataract surgery. METHODS: Ten post-cataract surgery capsular specimens were obtained during vitrectomy. Three sections of the anterior capsules were obtained during cataract surgery. A whole lens capsular bag immediately after lens extraction was obtained during vitrectomy. Cryosections of these specimens were processed for immunohistochemical analysis for TGF-beta1, TGF-beta2, TGF-beta3, TGF-beta receptor type I (TbetaR-I), type II (TbetaR-II) and type III (TbetaR-III), and were observed under light micros-copy. RESULTS: Lens epithelial cells (LECs) lining the inner surface of the anterior capsules exhibited immunoreactivity for TGF-beta2 and TbetaR-II. Immunoreactivity for TGF-beta1, -beta3, TbetaR-I and TbetaR-III was negative. In the whole capsular bag specimen, equatorial LECs were positive for TGF-beta1 and -beta2, but not for -beta3. In post-cataract surgery specimens, antibodies for each TGF-beta isoform labelled either the LECs or ECM accumulated on the capsules. Post-surgical LECs expressed TbetaR-I and TbetaR-II, and had also TbetaR-III in seven of the nine specimens examined. CONCLUSION: Expression pattern of TGF-beta s in quiescent LECs showed regional heterogeneity. Anterior LECs exhibited TGF-beta2 immunoreactivity, while equatorial LECs were positive for TGF-beta1 and -beta2. Quiescent LECs expressed TbetaR-II. LECs proliferating around IOLs expressed proteins of each TGF-beta isoform and each TbetaR. TGF-beta s were also localized in the ECM on capsules undergoing repair. TGF-beta3, TbetaR-I and TbetaR-III are up-regulated in LECs after cataract surgery.

[Clinical study of an outbreak of aseptic meningitis due to echovirus type 30 in Munakata City in 1997-1998].

From October, 1997 through July, 1998, an outbreak of aseptic meningitis due to echovirus type 30 occurred in the northern part of Kyushu area in Japan. In this outbreak, clinical and virologic observations were carried out on 157 in-patients with aseptic meningitis at our hospital. The age of the patients ranged from 1 year and 9 months to 57-year old. One hundred and twenty out of 157 cases were the children under 15 years of age, and in this age group, male/female ratio was 2:1. The largest proportion of cases occurred in the 5- to 9-year age group. The number of cases reached a peak in December, 1997, but the epidemic extended to the next summer. In 12 families, more than one person became ill (total 22 cases). Virus isolation from cerebrospinal fluid (CSF) was tried on 130 out of 157 cases. Echovirus 30 was isolated in 74 cases (58 children, 16 adults), and echovirus 18 in 9 cases from June, 1998 until the end of the study. Paired acute and convalescent sera were available from the 25 patients with negative virus isolation, and 7 out of 25 patients had a fourfold or greater rise in neutralizing antibodies. Headache, fever, vomiting, nuchal rigidity were detectable in most cases, but in this outbreak, continued severe headache was characteristic. Eye pain was experienced by 2% of the total cases. In children, gastrointestinal symptoms were noted in 12% of the cases, but were not in adult patients. The CSF cell counts ranged from 2 to 3,478 cells per cubic millimeter. Fifty-eight percent were predominantly lymphocytic, while 42% were polymorphonuclear predominant. Virus was highly isolated from the CSF when the specimens were obtained within three days after the onset of the acute illness, but in one case, virus was isolated on day 7. In a few cases, virus was isolated without pleocytosis in CSF.

Immunolocalization of c-Fos and c-Jun in rat ocular surface epithelium.

We immunohistochemically located c-Fos and c-Jun, the major components of transcription factor activator protein 1 (AP1), in normal epithelia of rat cornea and conjunctiva to determine the expression of these genes in the ocular surface epithelia. Immunoreactivity for c-Fos was detected in the nuclei of basal cells of the limbal and conjunctival epithelia, while that for c-Jun was detected in the cytoplasm of the cells of these epithelia. The corneal epithelium lacked immunoreactivity for either protein. AP1 may have an important role in the maintenance of homeostasis of limbal and conjunctival epithelia.

Expression of involucrin by ocular surface epithelia of patients with benign and malignant disorders.

PURPOSE: Keratinization of the ocular surface epithelium is associated with various disorders impairing vision. We immunohistochemically determined whether the ocular surface epithelia express involucrin, and whether its expression pattern may differ in benign vs. malignant disorders. Expression of cytokeratins was also examined to provide further information relative to the epithelial differentiation. METHODS: We evaluated 17 specimens; 6 specimens of the normal ocular surface epithelia, 3 specimens from cases of conjunctival intraepithelial neoplasia (CIN), 6 of conjunctival squamous cell carcinoma (SCC) and 2 of conjunctivae from cases of superior limbic keratoconjunctivitis (SLK). RESULTS: Corneal epithelium exhibited intracellular immunoreactivity for involucrin. Four of the 6 specimens of bulbar conjunctival epithelium showed involucrin immunoreactivity in the perimembranous region, whereas the fornical conjunctiva was negative. Cornified envelope in SLK specimens was positive for involucrin. The CIN showed its immunoreactivity in the perimembranous region in all levels of the hyperproliferative epithelium without keratinization, i.e., similar to the bulbar conjunctiva. The neoplastic cells of well-differentiated SCC showed involucrin in the perimembranous region, and those of moderately- to poorly-differentiated SCC have involucrin in their cytoplasm. The expression pattern of cytokeratins was unrelated to grade of malignancy in ocular SCC. CONCLUSION: The epithelia of normal subjects and of CIN expresses involucrin without keratinization. In contrary, the keratinized SLK epithelium markedly expresses involucrin in the cornified envelope. The subcellular immunolocalization of involucrin in the ocular SCC may help in evaluating the differentiation, i.e., malignancy, of neoplastic cells.

Immunolocalization of transcription factor AP1 in human ocular surface epithelia.

PURPOSE: The present study examined whether normal human ocular surfcae epithelia express AP1 components. Changes in expression patterns of these components in a case of ocular surface epithelial dysplasia was also evaluated before and after topical mitomycin C treatment. METHODS: Specimens of normal corneas (n = 2) and conjunctiva (n = 4) were obtained from 4 patients during cataract surgery or post mortem, while specimens of dysplastic epithelial tissue from the limbus were obtained from one patient. Specimens were immunohistochemically studied using antibodies against components of AP1. RESULTS: The normal corneal epithelium showed no staining with antibodies against c-Fos, Fra-2, FosB, c-Jun or JunB, whereas the limbal and bulbar conjunctival epithelia were positive for c-Fos, Fra-2, and c-Jun. Anti-FosB and -JunB antibodies reacted weakly with the conjunctival epithelium. JunD was absent in normal corneal and conjunctival epithelia. The dsyplastic epithelium showed positive labelling for c-Fos, Fra-2, c-Jun, and JunD throughout its thickness. Fra-1 was present in all specimens of epithelia examined. The dysplastic epithelium treated with mitomycin C was not labeled by anti-c-Fos or -Fra-2 antibody. CONCLUSION: Individual AP1 components show specific expression patterns in normal ocular surface epithelia and a case of dysplastic epithelium before and after topical MMC treatment, implying that these factors may play important roles in modulating epithelial cell function, e.g., proliferation and differentiation.