transforming-growth-factor-beta and Conjunctivitis

Macrophage migration inhibitory factor (MIF) is a pleiotropic, proinflammatory cytokine that mediates various immunoinflammatory processes. Ocular cicatricial pemphigoid (OCP) is an autoimmune disease in which affected conjunctivae show features of an immunoinflammatory disease. In this study, the role of MIF in the pathogenesis of OCP was examined.. The expression of MIF in conjunctival tissues of patients with OCP (n = 10) and normal subjects (n = 5) was studied by quantitative real-time PCR and immunohistochemistry. The production of MIF by conjunctival fibroblasts of normal control subjects and patients with OCP was determined, by using quantitative real-time PCR and enzyme-linked immunosorbent assay (ELISA). In addition, the effects of interleukin (IL)-1, tumor necrosis factor (TNF)-alpha, and transforming growth factor (TGF)-beta1 on the induction of MIF by conjunctival fibroblasts were studied by quantitative real-time PCR. To determine the relationship between conjunctival expression of MIF and accumulation of macrophages, in patients with OCP, a correlation study was performed.. An increased conjunctival expression of MIF was detected in patients with OCP, both at the mRNA (by real-time PCR) and protein level (by immunohistochemistry), compared with normal control patients. The expression of MIF was detected in the epithelial cells and occasionally in the stromal cells in control conjunctival tissues, by immunohistochemistry. In contrast, a statistically significant increase (P < 0.0001) in the expression of MIF was detected in the stromal cells of conjunctival tissues obtained from patients with OCP (control: 4.89 +/- 0.5; OCP: 19.82 +/- 1.34). By quantitative real-time PCR, compared with control conjunctiva, an increase in the expression of MIF was detected in the conjunctiva obtained from patients with OCP. A similar increase in the expression of MIF was also detected in conjunctival fibroblasts of patients with OCP, compared with control fibroblasts, by quantitative real-time PCR. A significantly increased (P < 0.001) level of MIF was also detected in supernatant collected from conjunctival fibroblasts of patients with OCP (186 +/- 5.4), compared with supernatant collected from control fibroblasts (9.3 +/- 7.6). Moreover, IL-1, TNF-alpha, and TGF-beta1, known factors involved in the pathogenesis of OCP, were found to induce the expression of MIF by conjunctival fibroblasts. A statistically significant correlation (P < 0.0001, r(2) = 0.4465) was observed between the expression of MIF and accumulation of CD68-positive macrophages in conjunctiva of patients with OCP.. This study demonstrated an increased conjunctival expression of MIF in patients with OCP. MIF may be actively involved in the pathogenesis of OCP, possibly regulating the inflammatory events of the disease process.

Topics: Conjunctiva; Conjunctivitis; Enzyme-Linked Immunosorbent Assay; Fibroblasts; Humans; Immunohistochemistry; Interleukin-1; Macrophage Migration-Inhibitory Factors; Pemphigoid, Benign Mucous Membrane; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Transforming Growth Factor beta; Transforming Growth Factor beta1; Tumor Necrosis Factor-alpha

Transforming growth factor-beta(TGF-beta) is an important mediator of wound healing responses. In the eye, TGF-beta activity has been implicated in causing corneal haze after laser surgery and subconjunctival scarring following glaucoma surgery. The purpose of the study was to determine whether small interference RNAs (siRNAs) targeting the type II receptor of TGF-beta (TbetaRII) could be used to suppress the TGF-beta action.. TbetaRII specific siRNAs designed from the human gene sequence were transfected into cultured human corneal fibroblasts. The protein and transcript levels of the receptor were determined by immunofluorescence, western blotting, and real time PCR. Immunofluorescence and immunoblotting were carried out to examine fibronectin assembly. A wound closure assay was used to assess cell migration in in vitro fibroblast cultures. In addition, the in vivo effects of TbetaRII siRNA were evaluated in a mouse model of ocular inflammation and fibrosis generated by subconjunctival injection of phosphate buffered saline and latex beads. Mouse TbetaRII siRNA was introduced into experimental eyes. Cellularity on tissue sections was evaluated after staining with hematoxylin and eosin. Collagen deposition was visualized by picrosirius red staining.. TbetaRII siRNAs abrogated the receptor transcript and protein expression in cultured corneal fibroblasts. The gene knockdown inhibited fibronectin assembly and retarded cell migration. In the mouse model, introduction of TbetaRII specific siRNA significantly reduced the inflammatory response and matrix deposition.. TbetaRII specific siRNAs were efficacious both in vitro and in vivo in knocking down the TGF-beta action. A direct application of siRNA into eyes to downregulate TbetaRII expression may provide a novel therapy for preventing ocular inflammation and scarring.

Topics: Adolescent; Adult; Animals; Blotting, Western; Cell Movement; Cells, Cultured; Collagen; Conjunctiva; Conjunctivitis; Cornea; Disease Models, Animal; Down-Regulation; Fibroblasts; Fibronectins; Fibrosis; Fluorescent Antibody Technique, Indirect; Humans; Mice; Mice, Inbred C57BL; Microscopy, Fluorescence; Middle Aged; Protein Serine-Threonine Kinases; Receptor, Transforming Growth Factor-beta Type II; Receptors, Transforming Growth Factor beta; Reverse Transcriptase Polymerase Chain Reaction; RNA Interference; RNA, Messenger; RNA, Small Interfering; Transfection; Transforming Growth Factor beta

Submucosal fibrosis due to excessive accumulation of collagens is an important histologic feature in the pathogenesis of ocular cicatricial pemphigoid (OCP). Heat shock protein 47 (HSP47), a collagen-binding protein, plays an important role in the biosynthesis of procollagens. In the present study, we examined the role of HSP47 in conjunctival scarring in patients with OCP.. Biopsy specimens of the conjunctiva of 15 patients with OCP and 5 normal subjects were studied for the expression of HSP47, transforming growth factor (TGF)-beta1, type I collagen, and type III collagen. The role of TGF-beta1 on the induction of HSP47 and type I collagen by conjunctival fibroblasts was studied by immunostaining, Western blot analysis, and quantitative real-time PCR.. Compared with the control, increased accumulations of type I and type III collagens were detected by immunohistochemistry in fibrotic conjunctiva of patients with OCP. Weak and sparse expression of HSP47 was detected in the epithelial cells and stromal fibroblasts in control conjunctival tissues. In contrast to the control, the expression of HSP47 was markedly increased in the stromal fibroblasts in conjunctival tissues obtained from patients with OCP, as detected by immunohistochemistry. By quantitative real-time PCR, compared with control conjunctival tissues, a 3.4-fold increase in the expression of HSP47 was noted in the conjunctival tissues obtained from patients with OCP. Similar to conjunctival tissues, fibroblasts isolated from conjunctiva of patients with OCP exhibited 4.8-fold increase in the expression of HSP47, compared with control fibroblasts. When conjunctival fibroblasts were treated with various concentration of TGF-beta1, upregulation in the expression of HSP47 and type I collagen was detected.. This study demonstrated increased expression of HSP47 and TGF-beta1 by conjunctival fibroblasts in biopsy specimens obtained from patients with OCP. TGF-beta1 induced the expression of HSP47 and type I collagen by conjunctival fibroblasts. Increased levels of TGF-beta1 and HSP47 may regulate increased synthesis, assembly, and production of collagens and thereby could significantly contribute to the process of conjunctival scarring in patients with OCP.

Topics: Blotting, Western; Collagen Type I; Collagen Type III; Conjunctiva; Conjunctivitis; Fibroblasts; Heat-Shock Proteins; HSP47 Heat-Shock Proteins; Humans; Immunoenzyme Techniques; Pemphigoid, Benign Mucous Membrane; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Transforming Growth Factor beta; Transforming Growth Factor beta1; Up-Regulation

Conjunctival fibrosis due to excessive accumulation of collagens is an important histologic feature in ocular cicatricial pemphigoid (OCP). Studies have suggested a role of transforming growth factor (TGF)-beta1 in conjunctival fibrosis in patients with OCP. Connective tissue growth factor (CTGF) is an important downstream mediator of TGF-beta1-induced collagen synthesis. CTGF usually acts synergistically with TGF-beta1 during the process of fibrosis in various organs. Hence, studying the mechanism by which CTGF influences TGF-beta1-induced synthesis of collagen in conjunctiva of patients with OCP would provide insight into the mechanism of conjunctival fibrosis in patients with OCP.. Biopsy specimens from conjunctiva of 10 patients with OCP and 5 normal subjects, were studied, with immunohistochemistry and real-time PCR, for the expression of CTGF and interstitial type I collagen. Using fibroblasts cultured from conjunctival biopsies we determined the effects of TGF-beta1 on the induction of CTGF and type I collagen by immunostaining, and quantitative real-time PCR. The effects of blocking the bioactivity of TGF-beta1 on the expression of CTGF and type I collagen were determined in TGF-beta1-stimulated fibroblasts, before and after treatment with type II receptor neutralizing antibody.. An increased stromal accumulation of interstitial type I collagen with an increased expression of CTGF was observed in biopsy sections of patients with OCP, compared with the control. By quantitative real-time PCR, a 3.2-fold increase in the expression of CTGF was detected in conjunctival tissues obtained from patients with OCP, compared with control conjunctiva. Fibroblasts isolated from conjunctiva of patients with OCP expressed 4.4-fold more CTGF, compared with control conjunctival fibroblasts, by real-time PCR. When these cultured fibroblasts were immunostained, an increased expression of CTGF was detected in fibroblasts isolated from patients with OCP, compared with control. Furthermore, when conjunctival fibroblasts were treated with TGF-beta1, an approximately ninefold increase in the expression of CTGF and an approximately threefold increase in the expression of type I collagen were detected by real-time PCR, compared with unstimulated fibroblasts. Finally, when antibody to TGF-beta type II receptor was added before TGF-beta1 treatment of these fibroblasts, the expression of type I collagen and CTGF was significantly reduced.. In the present study, an increased expression of CTGF was recorded in conjunctiva of patients with OCP. TGF-beta1 can induce production of CTGF and type I collagen by fibroblasts obtained from conjunctiva in OCP. This induction of CTGF by TGF-beta1 can be blocked by antibody to TGF-beta type II receptors. The findings lead to the conclusion that CTGF is one of the molecules involved in the pathogenesis of conjunctival fibrosis in patients with OCP.

Topics: Cells, Cultured; Collagen Type I; Conjunctiva; Conjunctivitis; Connective Tissue Growth Factor; Fibroblasts; Fibrosis; Humans; Immediate-Early Proteins; Immunoenzyme Techniques; Intercellular Signaling Peptides and Proteins; Pemphigoid, Benign Mucous Membrane; Protein Serine-Threonine Kinases; Receptor, Transforming Growth Factor-beta Type II; Receptors, Transforming Growth Factor beta; Reverse Transcriptase Polymerase Chain Reaction; Transforming Growth Factor beta; Transforming Growth Factor beta1

Oral administration of allergens can induce immune tolerance to specific allergens in rodents and hence might be a possibility to prevent and treat allergic diseases in human subjects. However, the gastrointestinal tract of mice is different from that of human subjects. The absorption of specific antigens and subsequent antigen presentation to intestinal T cells is different in both species, making it difficult to extrapolate results.. We investigated primary oral tolerance to ovalbumin (OVA) in an IgE high-responder dog model, which is more predictive for human allergic diseases than corresponding rodent models.. Oral tolerance was induced by means of a 28-day treatment with OVA dissolved in cow's milk.. We observed reduced OVA-specific IgE and IgG production in response to ensuing subcutaneous challenges. Allergic conjunctivitis induced by means of ocular and airway provocation was significantly reduced in tolerized animals compared with that seen in nontolerized control animals. In addition, eosinophilia and neutrophilia in bronchoalveolar lavage fluid and bronchoconstriction after airway allergen challenge were significantly suppressed in tolerized animals. Cytokine analysis by means of real-time PCR on bronchoalveloar fluid cells after allergen challenge revealed a high-level expression of IL-10 and transforming growth factor beta, predominantly in the CD14(+) population.. Feeding infant beagles with OVA for 4 weeks is sufficient to prevent hallmark manifestations of asthma and allergy in adult life. The mechanism of oral tolerance involved an increased expression of IL-10 and transforming growth factor beta cytokines.

Topics: Administration, Oral; Animals; Asthma; Conjunctivitis; Dogs; Hypersensitivity; Immune Tolerance; Immunoglobulin E; Immunoglobulin G; Interleukin-10; Ovalbumin; RNA, Messenger; Transforming Growth Factor beta

To characterise temporal changes in corneal wound repair at the LASIK flap margin.. 18 rabbits received monocular LASIK and were evaluated during 6 months using slit lamp and in vivo confocal microscopy. In three corneas, the exposed stroma was stained with DTAF. At various time points, corneas were processed for histology and stained for nuclei, f-actin, ED-A fibronectin, alpha-smooth muscle actin, TGF-beta1, TGF-beta2, TGF-beta receptor II, and CTGF.. At day 1, leucocytes migrated from the conjunctival vessels into the cornea. Near the limbus, the leucocytes were organised in long chains stretching towards the flap edge. From day 4, elongated fibroblasts migrated from the periphery to align in a circumferential band (approximately 250 microm wide) next to the flap edge. The lateral extension of this stromal band was delimited by the incisional gap in the epithelial basement membrane. TGF-beta1, TGF-beta2, TGF-beta receptor II, and CTGF were expressed in the band from day 2. Myofibroblasts were identified at week 3 and over time a 50 microm thick layer of fibrotic matrix was deposited. Concurrently, the peripheral circumferential band became narrower (width decreasing to 33% (SD 7%) at 4 months; n = 5) and showed an increased organisation with a gradual decline in reflectivity. At all time points, keratocytes within and below the flap remained quiescent and only minimal fibrosis developed at the interface.. Fibrotic wound repair following LASIK is restricted to a narrow band peripheral to the corneal flap edge. The lateral extension of the fibrosis is sharply delimited by the incisional gap in the epithelial basement membrane. The fibrotic wound healing at the LASIK flap margin is associated with myofibroblast transformation and wound contraction and involves a TGF-beta signalling pathway.

Topics: Actins; Animals; Basement Membrane; Conjunctivitis; Connective Tissue Growth Factor; Cornea; Corneal Stroma; Fibronectins; Fibrosis; Immediate-Early Proteins; Intercellular Signaling Peptides and Proteins; Keratitis; Keratomileusis, Laser In Situ; Microscopy, Confocal; Ophthalmoscopy; Protein Serine-Threonine Kinases; Rabbits; Receptor, Transforming Growth Factor-beta Type II; Receptors, Transforming Growth Factor beta; Transforming Growth Factor beta; Wound Healing