Effect of TNF, IL-1, and IL-6 on the proliferation of human Tenon's capsule fibroblasts in tissue culture

Lysophosphatidic Acid Modulates TGF-β2-Induced Biological Phenotype in Human Conjunctival Fibroblasts

BACKGROUND

Although lysophosphatidic acid (LPA) is known to have multiple pathophysiological roles, its contributions to ocular tissues, especially conjunctival fibrogenesis, remain to be elucidated.

METHODS

To study this issue, the effects of LPA on transforming growth factor-β2 (TGF-β2)-induced fibrogenesis of two-dimensional (2D) and three-dimensional (3D) cultures of human conjunctival fibroblasts (HconF) were examined by the following analyses: (1) planar proliferation determined by transepithelial electrical resistance (TEER) and fluorescein isothiocyanate (FITC)-dextran permeability measurements, (2) real-time metabolic analyses, (3) measurements of the size and stiffness of 3D spheroids, and (4) mRNA expression of extracellular matrix (ECM) molecules and their modulators.

RESULTS

LPA had no effect on TGF-β2-induced increase in the planar proliferation of HconF cells. LPA induced a more quiescent metabolic state in 2D HconF cells, but this metabolic suppression by LPA was partially blunted in the presence of TGF-β2. In contrast, LPA caused a substantial decrease in the hardness of 3D HconF spheroids independently of TGF-β2. In agreement with these different LPA-induced effects between 2D and 3D cultured HconF cells, mRNA expressions of ECM and their modulators were differently modulated.

CONCLUSION

The findings that LPA induced the inhibition of both TGF-β2-related and -unrelated subepithelial proliferation of HconF cells may be clinically applicable.

Effects of injectable platelet-rich fibrin (i-PRF) on pterygium surgery with conjunctival autograft

OBJECTIVES

To investigate the effects of subconjunctival injectable platelet-rich fibrin (i-PRF) injection on healing and complication rates after pterygium surgery with conjunctival autograft.

METHODS

This retrospective and comparative study evaluated 31 eyes that received i-PRF injections under the donor and graft conjunctiva following pterygium surgery, while 34 eyes did not receive i-PRF after the pterygium surgery. The patients' follow-up period was for 12 months. Postoperative recurrence, epithelial healing time, postoperative pain score, graft edema, and sliding of the graft (need for re-suturation) data were evaluated.

RESULTS

For the 12 months after surgery, one eye (3.2%) in the i-PRF group had developed corneal recurrence, and five eyes (14.7%) in the non-i-PRF group had developed recurrence. The mean corneal epithelial healing time was 2.96 ± 0.70 days in the i-PRF group and 3.58 ± 0.70 days in the non-i-PRF group (p = 0.001). The mean healing time of the donor conjunctiva epithelium was 3.84 ± 0.70 days in the i-PRF group, whereas it was 4.44 ± 0.74 days in the non-i-PRF group (p = 0.006). The mean postoperative pain score was 4.45 ± 1.52 in the i-PRF group and 5.08 ± 1.40 in the non-i-PRF group. In the non-i-PRF group, three cases (8.8%) required re-suturation, whereas, in the i-PRF group, no one required re-suturation.

CONCLUSIONS

Thanks to its platelets-derived growth factors, i-PRF can be a safe and effective adjuvant therapy for faster healing of conjunctival autograft and in the prevention of recurrence.

Aqueous humor cytokine levels are associated with the severity of visual field defects in patients with primary open-angle glaucoma

BACKGROUND

To evaluate the aqueous humor (AH) levels of cytokines in primary open-angle glaucoma (POAG) patients and cataract patients.

METHODS

Thirty-eight POAG patients and 26 cataract patients were recruited. Peripheral blood (PB) was collected from each subject. The POAG group was divided into 2 subgroups according to the severity of visual field defects. The cutoff point of the mean deviation (MD) of the visual field was -12 dB. AH was obtained at the time of anterior chamber puncture during cataract or glaucoma surgery by using a 27-gauge needle attached to a microsyringe. AH and PB levels of interleukin-2 (IL-2), tumor necrosis factor-alpha (TNF-α), transforming growth factor-beta2 (TGF-β2) and IL-4 were assayed by enzyme-linked immunosorbent assay. Postoperative intraocular pressures (IOPs) of POAG patients were recorded during the follow-up period.

RESULTS

TNF-α and TGF-β2 showed significantly higher AH levels in the POAG group than in the cataract group (P < 0.001 and P = 0.001, respectively). For the POAG group, preoperative IOPs were significantly positively correlated with AH levels of TNF-α (r² = 0.129, P = 0.027) and TGF-β2 (r² = 0.273, P = 0.001). AH levels of TGF-β2 were significantly different among cataract patients, POAG patients with MD> -12 dB and POAG patients with MD≤ -12 dB (P = 0.001). AH levels of TNF-α were significantly positively associated with IOP reduction after trabeculectomy (P = 0.025). AH and PB levels of cytokines were not related to the long-term success of trabeculectomy.

CONCLUSION

The levels of TNF-α and TGF-β2 showed different profiles in POAG patients and cataract patients. AH levels of TGF-β2 were correlated with the severity of glaucomatous neuropathy in POAG patients. The findings suggest possible roles for cytokines in the pathogenesis and development of POAG.

Goniotomy for Non-Infectious Uveitic Glaucoma in Children

Secondary glaucoma is still a blinding complication in childhood uveitis, for which most commonly used surgical interventions (trabeculectomy or glaucoma drainage implant) involve multiple re-interventions and/or complications postoperatively. The goniotomy procedure has never been investigated in the current era, in which patients with pediatric uveitis receive biologics as immunosuppressive therapy for a prolonged period, with potential implications for the outcome. The purpose of the study is to evaluate the efficacy and safety of a goniotomy procedure in pediatric non-infectious uveitis in a retrospective, multicenter case series. The primary outcomes were the postoperative intraocular pressure (IOP), number of IOP-lowering medications, and success rate. Postoperative success was defined as 6 ≤ IOP ≤ 21 mmHg, without major complications or re-interventions. Fifteen eyes of ten children were included. Median age of the included patients at goniotomy was 7 years; median follow-up was 59 months. Median (interquartile range) IOP before surgery was 30 (26–34) mmHg with 4 (3–4) IOP-lowering medications. At 1, 2, and 5 years after goniotomy, median IOP was 15, 14, and 15 mmHg with 2 (0–2), 1 (0–2), and 0 (0–2) medications, respectively (p < 0.001 postoperatively versus preoperatively for all timepoints). Success rate was 100%, 93%, and 80% after 1, 2, and 5 years, respectively. There were no significant changes in visual acuity and uveitis activity or its treatment, and there were no major complications. Our results show that the goniotomy is an effective and safe surgery for children with uveitic glaucoma.

Role of fibroblast plasticity and heterogeneity in modulating angiogenesis and healing in the diabetic foot ulcer

Chronic diabetic foot ulcers (DFUs) are an important clinical issue faced by clinicians despite the advanced treatment strategies consisting of wound debridement, off-loading, medication, wound dressings, and keeping the ulcer clean. Non-healing DFUs are associated with the risk of amputation, increased morbidity and mortality, and economic stress. Neo-angiogenesis and granulation tissue formation are necessary for physiological DFU healing and acute inflammation play a key role in healing. However, chronic inflammation in association with diabetic complications holds the ulcer in the inflammatory phase without progressing to the resolution phase contributing to non-healing. Fibroblasts acquiring myofibroblasts phenotype contribute to granulation tissue formation and angiogenesis. However, recent studies suggest the presence of five subtypes of fibroblast population and of changing density in non-healing DFUs. Further, the association of fibroblast plasticity and heterogeneity with wound healing suggests that the switch in fibroblast phenotype may affect wound healing. The fibroblast phenotype shift and altered function may be due to the presence of chronic inflammation or a diabetic wound microenvironment. This review focuses on the role of fibroblast plasticity and heterogeneity, the effect of hyperglycemia and inflammatory cytokines on fibroblasts, and the interaction of fibroblasts with other cells in diabetic wound microenvironment in the perspective of DFU healing. Next, we summarize secretory, angiogenic, and angiostatic phenotypes of fibroblast which have been discussed in other organ systems but not in relation to DFUs followed by the perspective on the role of their phenotypes in promoting angiogenesis in DFUs.

Uveitic glaucoma in children: a systematic review on surgical outcomes

Purpose

To compare the outcomes and complications of different surgical interventions for secondary glaucoma in pediatric uveitis.

Methods

Systematic review following the PRISMA standards. Main inclusion criteria were surgery for secondary glaucoma in pediatric uveitis at a mean age of 16 years or below, a mean follow-up period of at least 1 year after surgery, and at least 10 eyes per surgical intervention per study. We used the GRADE approach to assess study quality. Primary outcomes were intraocular pressure (IOP) and number of IOP lowering medications before and after surgery. Secondary outcomes were success rate and complications.

Results

Fourteen studies fulfilled the inclusion criteria, in which one (n = 11) or more (n = 3) surgical interventions were described, comprising in total six different procedures. According to the GRADE criteria, the quality of the studies was low to very low, in particular because of the small size and the applied study designs. All surgical interventions provided a significant decrease in IOP and number of IOP lowering medications. The success rates during follow-up varied widely, with the lowest rates of success after cyclophotocoagulation. The most frequently reported complications were ocular hypertension, hypotony, and hyphema, with an indication for a reoperation in more than one-third of the cases. Permanent vision loss was infrequently seen and was attributed to prolonged hypotony.

Conclusions

The described surgical interventions are able to prevent blindness by lowering a medically uncontrolled IOP to an acceptable level. Therefore, there is a crucial role for surgical intervention in these children. Based on the present studies, no preferences can be made. Given the reported complications, more research with larger sample sizes and direct comparisons is needed to determine the most successful glaucoma treatment in children with uveitis.

Zinc Oxide Tetrapods Modulate Wound Healing and Cytokine Release In Vitro—A New Antiproliferative Substance in Glaucoma Filtering Surgery

Glaucoma filtering surgery is applied to reduce intraocular pressure (IOP) in cases of uncontrolled glaucoma. However, postoperative fibrosis reduces the long-term success of both standard trabeculectomy and microstents. The aim of this study was to test the antiproliferative and anti-inflammatory potential of ZnO-tetrapods (ZnO-T) on human Tenon’s fibroblasts (HTFs) for glaucoma surgery. The toxicity of ZnO-T on HTFs was determined using an MTT test. For analysis of fibroblast proliferation, migration, and transdifferentiation, cultures were stained for Ki67, alpha-smooth muscle actin (α-SMA), and p-SMAD. A fully quantitative multiplex ELISA was used to determine the concentrations of different cytokines, platelet-derived growth factor (PDGF), and hepatocyte growth factor (HGF) in culture supernatants with and without previous ZnO-T treatment. Treatment with higher concentrations (10 and 20 µg/mL) was associated with HTF toxicity, as shown in the wound healing assay. Furthermore, the number of Ki67, α-SMA-positive, and pSMAD-positive cells, as well as IL-6 and HGF in supernatants, were significantly reduced following incubation with ZnO-T. In conclusion, we were able to show the antiproliferative and anti-inflammatory potentials of ZnO-T. Therefore, the use of ZnO-T may provide a new approach to reducing postoperative fibrosis in glaucoma filtering surgery.

Cytokine profile in tear and aqueous humor of primary open-angle patients as a prognostic factor for trabeculectomy outcome

OBJECTIVE

To evaluate the cytokine profile in tear and aqueous humor in primary open-angle glaucoma before trabeculectomy and correlate preoperative cytokine levels with the surgical outcome.

METHODS

Prospective study. Twenty-nine patients with primary open-angle glaucoma undergoing primary trabeculectomy were included. Levels of 27 cytokines were measured in tear an aqueous humor using the Bio-Plex Pro Human Cytokine 27-Plex Immunoassay kit (Bio-Rad Laboratories, Hercules, CA, USA).

RESULTS

29 patients who underwent trabeculectomy were included and their first-year follow-up visits were recorded. Mean age was 76.0 ± 7.0 years (range 56-84), mean intraocular pressure was 18.2 ± 3.6 mmHg and mean number of topical medications was 2.3 ± 0.9. At the one-year visit, 5 patients were classified as surgical failure. In aqueous humor, preoperative cytokine levels of regulated on activation normal T cell expressed and secreted (RANTES) were significantly higher in those patients with surgical failure at one year. IL-8 in tear and interferon gamma-induced protein (IP-10) in aqueous humor correlated positively with one-year IOP reduction. No statistically significant correlations were found with changes in visual field mean defect or global peripapillary retinal nerve fiber layer thickness (all, p >0.05).

CONCLUSIONS

Preoperative RANTES levels in aqueous humor as well as other cytokines could serve as useful biomarkers for trabeculectomy outcome.

The role of polymorphisms rs2070744 and rs1799983 eNOS gene in patients with POAG: a systematic review and meta-analysis

BACKGROUND

Glaucoma is a progressive disease of the optic nerve that has several underlying causes, but in most cases, the cause is unknown. Given the importance of the role of nitric oxide in the occurrence of ocular nerve damage and the effect of eNOS gene polymorphic sites on protein function, to better understand the mechanism of formation of POAG, the relationship between polymorphisms rs2070744 and rs1799983 eNOS gene with POAG risk was investigated in this study using meta-analysis.

METHODS

In this study, systematic review and meta-analysis of study data related to the study of polymorphisms rs2070744 and rs1799983 eNOS gene in patients with POAG using the keywords eNOS, NOS3, Gluuc8898, POAG, primary open-angle glaucoma. It was extracted from SID, MagIran, IranMedex, IranDoc, ScienceDirect, Embase, Scopus, PubMed, Web of Science, and Google Scholar search engines without a time limit until May 2020. To perform the analysis of qualified studies, the model of random effects was used and the inconsistency of studies with the I² index was investigated. Data analysis was performed with Comprehensive Meta-Analysis (Version 2).

RESULTS

In a review of 16 studies (9 studies on polymorphism rs2070744 and seven studies on polymorphism rs1799983) with a sample size of 1631 subjects and a control group of 2405 subjects related to polymorphism rs2070744 and a group of 1456 subjects and a control group of 2240 subjects related to polymorphism 9997 rs1, the odds ratio of TT, CT, and CC genotypes was reported to be 0.95, 1.01, and 1.14, respectively, and the odds ratio of GG, GT and TT genotypes to be 0.88, 0.97, and 1.31, respectively, was reported in patients with POAG.

CONCLUSION

The results of our systematic review and meta-analysis study show that the eNOS gene polymorphisms rs2070744 and rs1799983 may increase the risk of POAG among individuals. However, further studies are needed to confirm these findings.

Elevated levels of prostaglandin E2 in the tears of patients with severe allergic conjunctivitis and primary cultured conjunctival cells are suppressed by ketotifen and dexamethasone

Objective

We examined the production of prostaglandin E₂ (PGE₂), which is the key prostaglandin involved in inflammatory disorders of the ocular surface. Tears and conjunctival fibroblasts were evaluated in order to assess allergic inflammation and the effect of specific drugs.

Methods and analysis

PGE₂ was measured in tears from both patients and normal volunteers. Primary cultures of human conjunctival fibroblasts were incubated with interleukin (IL)-4 and tumour necrosis factor (TNF)-α with or without ketotifen fumarate or dexamethasone. The culture supernatants were removed 24 hours after exposure and the concentrations of PGE₂ were quantified by ELISA.

Results

Significantly higher levels of PGE₂ were observed in the tears of patients with severe allergic conjunctivitis than in those with post-surgical inflammation (p=0.02), and this production was reduced by eye drops. Stimulation with IL-4 and TNF-α induced the generation of PGE₂ in supernatants of conjunctival fibroblasts, and this production was significantly downregulated by ketotifen fumarate or steroids.

Conclusion

PGE₂ may participate in the pathogenesis of severe ocular allergic disease, and both ketotifen fumarate and steroid reduce the production of PGE₂.

Neferine suppresses autophagy-induced inflammation, oxidative stress and adipocyte differentiation in Graves' orbitopathy

Previous studies in Graves’ orbitopathy (GO) patient‐derived fibroblasts showed that inhibition of autophagy suppresses adipogenic differentiation. Autophagy activation is associated with inflammation, production of reactive oxygen species and fibrosis. Neferine is an alkaloid extracted from Nelumbo nucifera, which induces Nrf2 expression and inhibits autophagy. Here, we have elucidated the role of neferine on interleukin (IL)‐13‐induced autophagy using patient‐derived orbital fibroblasts as an in vitro model of GO. GO patient‐derived orbital fibroblasts were isolated and cultured to generate an in vitro model of GO. Autophagy was determined by Western blot detection of the markers such as Beclin‐1, Atg‐5 and LC3 and by immunofluorescence detection of autophagosome formation. Analysis of differentiation towards an adipogenic lineage was performed by Oil red O staining. The expression of inflammatory factors was detected by ELISA and semiquantitative RT‐PCR. Neferine inhibited autophagy in GO orbital fibroblasts, as indicated by the suppression of IL‐13‐induced autophagosome formation, overexpression of autophagy markers, increased LC3‐II/LC3‐I levels and finally down‐regulation of p62. Neferine suppressed IL‐13‐induced inflammation, ROS generation, fibrosis and adipogenic differentiation in GO patient‐derived orbital fibroblasts. The anti‐inflammatory, antioxidant and antiadipogenic effects of neferine were accompanied by the up‐regulation of Nrf2. These results indicated that orbital tissue remodelling and inflammation in GO may be mediated by autophagy, and neferine suppressed autophagy‐related inflammation and adipogenesis through a mechanism involving Nrf2.

Isoliquiritigenin protects against angiotensin II-induced fibrogenesis by inhibiting NF-κB/PPARγ inflammatory pathway in human Tenon's capsule fibroblasts

PURPOSE

To examine the protective effects of Isoliquiritigenin (ISL) in angiotensin II (ANG II)-induced inflammation and fibrosis on Human Tenon's capsule Fibroblasts (HTFs) and Mouse Peritoneal Macrophages (MPMs). This study also investigated the potential mechanism of action of ISL.

METHOD

Methyl-thiazolyl tetrazolium (MTT) assay was used to test ISL toxicity. An ELISA and an RT-qPCR assay detected the inflammatory cytokines (TNF-α, IL-6, COX-2, and ICAM-1). A Western blot investigated the expression levels of inflammation-related signals [nuclear factor-κB (NF-κB), peroxisome proliferator-activated receptor γ (PPARγ)], and fibrogenesis, including fibronectin and alpha-smooth muscle actin (α-SMA)]. Protein expressions of α-SMA were measured by immunofluorescence.

RESULTS

Pre-treatment with ISL (10 or 20 μM) dose-dependently decreased the mRNA levels of TNF-α, IL-6, ICAM-1, and COX-2 induced by ANG II (1 μg/ml) in both MPMs and HTFs. ANG II remarkably increased the amount of P65 in the nuclei and decreased the amount of P65 in the cytoplasm. Additionally, ANG II reduced PPARγ expression levels in a time-dependent manner. Furthermore, these effects which were induced by ISL were remarkably neutralized by ISL pre-treatment. Finally, ANG II markedly elevated the expression of fibronectin and α-SMA.

CONCLUSION

ISL could alleviate ANG II-induced fibrogenesis by inhibiting the NF-κB/PPARγ inflammatory pathway. In addition, ISL may be a potential agent for the treatment of conjunctival fibrosis. Most importantly, the NF-κB/PPARγ signaling pathway could be an effective therapeutic target for the prevention and treatment of conjunctival fibrosis after glaucoma surgery.

The Effect of Cytokine-Stimulation and Pharmacologic Intervention on PGE2 Production in Primary Human Conjunctival and Corneal Cells

We studied the production of PGE2 by human conjunctival and corneal cells in response to inflammation, and reduction of inflammation with non-steroidal anti-inflammatory drugs. Primary cultures of human conjunctival epithelial cells, fibroblasts, corneal epithelial cells, and keratocytes were incubated with IL-4 and TNF-α. PGE2 and COX-2 levels were analyzed. Effects of anti-inflammatory and anti-immune drugs on PGE2 production were also investigated. IL-4 and TNF-α induced the generation of PGE2 and COX-2 in conjunctival and corneal cells. Epithelial PGE2 production was significantly lower than in keratocytes and fibroblasts, which was down-regulated by aspirin. IL-4 and TNF-α enhanced the inflammatory response via prostaglandin production which contributed to ocular surface inflammation. Prostaglandin production was higher in stromal cells than epithelial cells. These results suggest that the epithelial barrier disruption may contribute to ocular allergic inflammation by the PGE2 production from stromal cells. Moreover, NSAIDs were effective in suppressing PGE2 production in our experiment.

Comparison of Photochemical Crosslinking Versus Sutures for Bonding Conjunctival Grafts

BACKGROUND AND OBJECTIVES

To explore whether Rose Bengal-induced photochemical crosslinking (RB-PCL) can be a replacement for sutures in conjunctival autograft bonding, we compared the safety, operating time, postoperative ocular signs, and inflammatory responses of RB-PCL versus nylon suturing for sealing conjunctival autografts in rabbits.

STUDY DESIGN/MATERIALS AND METHODS

Thirty-six New Zealand White rabbits underwent limbal conjunctival autografting using either sutures or RB-PCL to attach conjunctival autografts to the bare sclera. Animals were randomized to one of two groups (18 per group): the suture group or RB-PCL group. Photochemical crosslinking with a wavelength of 532 nm green light with an illumination intensity of 0.6 W/cm² for 250 seconds (150 J/cm² ) or suturing was performed followed by light examination at 3, 7, 28 days after surgery to evaluate the healing condition. Rabbits in each group were euthanized on day 3 (n = 6), 7 (n = 6), or 28 (n = 6) postoperatively, and the graft tissues from the surgical site were processed to evaluate inflammatory response by assessing protein levels of tumor necrosis factor α (TNF-α), and interleukin 6 (IL-6) as well as histological examination. Cell viability was evaluated by counting both total and dead cells on hematoxylin and eosin (H&E) stained tissue samples from both groups at 3 and 7 days after surgery. The surgery procedure time was recorded and the graft surface temperatures were measured before and after illumination.

RESULTS

Photochemical crosslinking effectively secured the limbal conjunctival autograft over an ocular conjunctival defect with no significant difference from the suture group. The time required for this light activated bonding method was ~550 seconds in comparison with the suture method of half hour. The differences of measured temperature on the graft surface before and after RB-PCL treatment were 2.98 ± 0.11°C. The induction of IL-6 and TNF-α protein was remarkably reduced in the RB-PCL group compared with the suture group at 3 and 7 days after surgery. Histology revealed less infiltrated neutrophils were observed in the RB-PCL group than in the suture group at 3 and 7 days postoperatively. Furthermore, the RB-PCL group showed a better healing process with less eye discharge and mild conjunctival congestion. No significant difference in percent dead cells was observed between RB-PCL and suture groups at 3 and 7 days after surgery.

CONCLUSIONS

RB-PCL is a promising alternative for bonding the conjunctival autograft with shorter operation time, less inflammation and better healing outcomes compared to conventional suture. Thermal damage and phototoxicity were not observed using the RB-PCL method in bonding conjunctival grafts. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Investigation of Conjunctival Fibrosis Response Using a 3D Glaucoma Tenon's Capsule + Conjunctival Model

Purpose

Surgical techniques such as trabeculectomy aim to treat glaucoma by making an incision into the scleral tissue, to create an alternative drainage pathway for aqueous to flow into the sub-Tenon's/subconjunctival space. However, tissue fibrosis and wound healing occurring after the procedures can reduce the success rate. This study aims to investigate the synergistic effects of aqueous humor in combination with shear stress on the fibrosis response occurring in Tenon's capsule and conjunctival tissue (TCCT) after glaucoma surgery.

Methods

Two-dimensional (2D) and 3D in vitro TCCT models were constructed by seeding porcine Tenon's capsule + conjunctival fibroblasts in collagen gel. These were used to investigate key growth factors (singular and natural form) with shear stress, which are believed to influence tissue fibrosis after glaucoma surgery. In addition to cell proliferation assessments, a nondestructive assay to quantify neocollagen synthesis in TCCT models, in response to these factors, has been applied up to 14 days.

Results

TCCT fibroblast proliferation increased significantly with doses of TGF-β, TNF-α, and VEGF, in comparison with the control. Furthermore, fibroblasts exposed to 50% aqueous humor had significantly increased proliferation and actin expression. Shear stress-induced mechanotransduction was also found to promote metabolic activity across experimental conditions. Neocollagen labeling cross validated the fibrosis process.

Conclusions

Shear stress appeared to enhance the influence of key growth factors and further promoted fibrotic response within the model. These findings offer a useful insight for further study into the wound-healing response triggered by aqueous fluid outflow after glaucoma surgery.

Sirt1 Protects against Oxidative Stress-Induced Apoptosis in Fibroblasts from Psoriatic Patients: A New Insight into the Pathogenetic Mechanisms of Psoriasis

Psoriasis, a multisystem chronic disease characterized by abnormal keratinocyte proliferation, has an unclear pathogenesis where systemic inflammation and oxidative stress play mutual roles. Dermal fibroblasts, which are known to provide a crucial microenvironment for epidermal keratinocyte function, represented the selected experimental model in our study which aimed to clarify the potential role of SIRT1 in the pathogenetic mechanisms of the disease. We firstly detected the presence of oxidative stress (lipid peroxidation and total antioxidant capacity), significantly reduced SIRT1 expression level and activity, mitochondrial damage and apoptosis (caspase-3, -8 and -9 activities) in psoriatic fibroblasts. Upon SIRT1 activation, redox balance was re-established, mitochondrial function was restored and apoptosis was no longer evident. Furthermore, we examined p38, ERK and JNK activation, which was strongly altered in psoriatic fibroblasts, in response to SIRT1 activation and we measured caspase-3 activity in the presence of specific MAPK inhibitors demonstrating the key role of the SIRT1 pathway against apoptotic cell death via MAPK modulation. Our results clearly demonstrate the involvement of SIRT1 in the protective mechanisms related to fibroblast injury in psoriasis. SIRT1 activation exerts an active role in restoring both mitochondrial function and redox balance via modulation of MAPK signaling. Hence, SIRT1 can be proposed as a specific tool for the treatment of psoriasis.

Endocan Overexpression in Pterygium

PURPOSE

The aim of this study was to evaluate the possible role of endocan in the pathogenesis of pterygium.

METHODS

The study was conducted on 33 patients with primary pterygium and 20 control subjects with normal bulbar conjunctiva. Patients with pterygium were graded into 3 groups as atrophic, fleshy, and intermediate, according to the Tan classification. Primary nasal pterygia and normal bulbar conjunctivas were surgically removed. Endocan expression was immunohistochemically investigated.

RESULTS

Endocan expression in epithelial and endothelial cells was statistically significantly higher in pterygium tissues than control tissues (P = 0.001). No significant correlation was observed between pterygium classification groups and endocan expression in both epithelial and endothelial cells (P > 0.05).

CONCLUSIONS

The results suggest that endocan may have a role in the pathogenesis of pterygium.

Nano-sized carriers in gene therapy for peritoneal fibrosis in vivo

Peritoneal fibrosis is a crucial complication in patients receiving peritoneal dialysis. It is a major pathological feature of peritoneal membrane failure, which leads to withdrawal of peritoneal dialysis. No specific therapy has yet been established for the treatment of peritoneal fibrosis. However, gene therapy may be a viable option, and various nano-sized carriers, including viral and non-viral vectors, have been shown to enhance the delivery and efficacy of gene therapy for peritoneal fibrosis in vivo. This review focuses on the use of nano-sized carriers in gene therapy of peritoneal fibrosis in vivo.

Chemokine (C-C motif) ligand 2 and chemokine (C-C motif) ligand 7 in angle-closure glaucoma

PURPOSE

To compare the concentrations of chemokine (C-C motif) ligand 2 (CCL2) and chemokine (C-C motif) ligand 7 (CCL7) in aqueous humour of eyes with acute primary angle-closure (APAC), primary angle-closure glaucoma (PACG) or with age-related cataract.

METHODS

The prospective investigation included a study group of 56 patients (24 patients with APAC; 32 patients with PACG) undergoing glaucoma surgery and a control group of 21 patients undergoing routine cataract surgery. The interval between glaucoma attack and trabeculectomy was 19.4 ± 9.8 days.

RESULTS

The concentrations of CCL2 (3037 ± 501 versus 1127 ± 141 pg/ml; p = 0.003) and CCL7 (10.5 ± 2.4 versus 2.8 ± 0.4 pg/ml; p < 0.001) were significantly higher in the APAC group than in the PACG group, while the concentrations of both cytokines did not differ significantly between the PACG group and the control group (CCL2: 1190 ± 98 pg/ml; p = 0.10; CCL7: 2.0 ± 0.6; p = 0.18). The concentrations of both cytokines were significantly and inversely correlated with the interval between the acute angle-closure attack and surgery (CCL2: p = 0.02; ρ = -0.48; CCL7: p = 0.04; ρ = -0.42). Higher CCL2 concentrations were associated with higher prevalence of surgical failure (28.6% versus 7.1%; p = 0.036).

CONCLUSIONS

Concentrations of CCL2 and CCL7 as major inflammatory cytokines with potential influence on the risk of filtering surgery failure were significantly elevated after an acute glaucoma attack and decreased with longer interval to the attack. Trabeculectomy may have a lower risk of failure if performed later than earlier after an acute glaucoma attack, with lower CCL2 concentrations associated with better surgical outcome.

Current and Future Techniques in Wound Healing Modulation after Glaucoma Filtering Surgeries

Filtering surgeries are frequently used for controlling intraocular pressure in glaucoma patients. The long-term success of operation is intimately influenced by the process of wound healing at the site of surgery. Indeed, if has not been anticipated and managed accordingly, filtering surgery in high-risk patients could end up in bleb failure. Several strategies have been developed so far to overcome excessive scarring after filtering surgery. The principal step involves meticulous tissue handling and modification of surgical technique, which can minimize the severity of wound healing response at the first place. However, this is usually insufficient, especially in those with high-risk criteria. Thus, several adjuvants have been tried to stifle the exuberant scarring after filtration surgery. Conventionally, corticosteroids and anti-fibrotic agents (including 5-fluorouracil and Mitomycin-C) have been used for over three decades with semi-acceptable outcomes. Blebs and bleb associated complications are catastrophic side effects of anti-fibrotic agents, which occasionally are encountered in a subset of patients. Therefore, research continues to find a safer, yet effective adjuvant for filtering surgery. Recent efforts have primarily focused on selective inhibition of growth factors that promote scarring during wound healing process. Currently, only anti-VEGF agents have gained widespread acceptance to be translated into routine clinical practice. Robust evidence for other agents is still lacking and future confirmative studies are warranted. In this review, we explain the importance of wound healing process during filtering surgery, and describe the conventional as well as potential future adjuvants for filtration surgeries.

Nitric oxide secretion in human conjunctival fibroblasts is inhibited by alpha linolenic acid

Purpose

It is known that both human conjunctival fibroblasts (HCF) and corneal epithelial (HCE) cells contribute to the inflammatory process in the ocular surface by releasing inflammatory cytokines. In addition, nitric oxide (NO) has an important role in inflammatory responses in the ocular surface. In the present study, we aimed to characterize the capacity of these cells to release nitric oxide in response to cytokines and Lipopolysaccharide (LPS), and show that Alpha-linoleic acid (ALA) inhibits these responses.

Methods

HCF, HCE cells, peripheral blood mononuclear cells (PBMCs) and co-culture of HCF and PBMC were treated with different combinations of inflammatory inducers, including interleukin)IL- (6, tumor necrosis factors (TNF)-α, interferon (IFN)- γ and IL-1β and LPS. Nitrite levels were measured in cell supernatants with and without ALA by the Griess reaction test at 24, 48 and 72 h respectively. Expression of nitric oxide synthase 2 (NOS-2) was evaluated by real-time PCR.

Results

All cytokine combinations had an inducible effect on nitrite secretion in HCF, PBMC and co-cultured PBMC and HCF, but not in HCE cells. Treatment with a combination of IL-6, LPS, TNF-α, IFN- γ and IL-1β induced the highest nitrite secretion (2.91 fold, P < 0.01) as compared to cells incubated in medium alone. nitrite secretion was reduced by 38.9 % (P < 0.05) after treatment with ALA alone. Co-culturing PBMC with HCF with and without ALA treatment demonstrated similar results in nitrite level as,compared to PBMC alone. In addition, ALA significantly decreased NOS-2 expression in HCF by 48.9 % (P < 0. 001) after 72 h.

Conclusions

The decrease in nitrite release and inhibition of NOS-2 expression indicate that ALA may have an anti-inflammatory effect both on HCF and on peripheral immune cells. This indicates that ALA may serve as a potent anti-inflammatory agent in ocular surface inflammation.

Modulation of wound healing in glaucoma surgery

Glaucoma is a neurodegenerative disease and is the second most important cause of irreversible blindness. Filtration surgery remains the most effective therapy to reduce intraocular pressure in glaucoma patients. The main determinant of long-term surgical success is the healing response. Excessive postoperative wound healing with subsequent fibrosis may lead to obstruction of the created channel which frequently results in early surgical failure and consequent progression of visual field loss. Preoperative use of antimitotics, such as mitomycin-C and 5-fluorouracyl, effectively improves surgery outcome. However, the use of these nonspecific antiproliferative agents can be associated with severe side effects. This review provides an overview of the most important efforts that have been made to explore novel, more specific, and safer agents to prevent glaucoma filtration failure and improve surgery outcome.

Recurrence After Primary Pterygium Excision: Amniotic Membrane Transplantation with Fibrin Glue Versus Conjunctival Autograft with Fibrin Glue

PURPOSE

The aim of the present study was to compare the surgical results and recurrence rates of primary pterygium excision with conjunctival autografts versus amniotic membrane grafts fixated with fibrin glue.

MATERIALS AND METHODS

In this prospective study, 73 eyes of 65 patients who had undergone conjunctival autograft group (CAG) (n:37) or amniotic membrane group (AMG) (n:36) after pterygium excision were evaluated. Fibrin glue was used for the fixation of grafts in both groups. The patients were followed up for 12 months. Postoperative complications were recorded. The rate of recurrence was defined as the primary outcome measure.

RESULTS

In the CAG, partial dehiscence of the graft was observed on the nasal edge on postoperative day 1 in two (5.4%) eyes that healed with secondary re-epithelialization at week 1. Twelve (32.4%) eyes showed a yellowish-orange or hemorrhagic edema of the graft on postoperative day 7 that spontaneously resolved in 1 to 3 weeks. In the AMG, partial dehiscence and folding of the amniotic membrane occurred in two (5.5%) eyes. Two eyes (5.4 %) in the CAG developed corneal recurrence and five eyes (13.8%) in the amniotic membrane graft group developed recurrence; one limbal (2.7%), four corneal recurrences (11.1%) (p = 0.25).

CONCLUSION

Fibrin glue is a safe and effective method for attaching conjunctival or amniotic membrane grafts for wound closure following pterygium surgery. Although the results were not statistically significant, amniotic membrane grafting using fibrin glue seems to have a higher pterygium recurrence rate compared with conjunctival autografting.

Improving patient outcomes following glaucoma surgery: state of the art and future perspectives

Of all the treatments currently used to lower intraocular pressure in glaucoma patients, filtration surgery is known to be the most effective. However, in a significant percentage of cases, the constructed channel closes due to excessive scar formation, resulting in surgical failure. The process of postoperative wound healing is characterized by the coagulative and inflammatory phase, followed by the proliferative and repair phase, and finally the remodeling phase. Perioperative antimitotic agents, such as mitomycin C and 5-fluorouracil, are known to modulate the process of wound healing and to improve surgical outcome, but they carry a risk of vision-threatening complications. New alternative strategies to prevent filtration failure, such as inhibition of transforming growth factor-β, vascular endothelial growth factor, and placental growth factor, have shown promising results in the improvement of surgical success. However, it remains necessary to broaden the therapeutic approach by focusing on combined therapies and on extended drug delivery.

Hyphema is a risk factor for failure of trabeculectomy in neovascular glaucoma: a retrospective analysis

Background

Several retinal ischemic diseases can cause neovascular glaucoma (NVG). Trabeculectomy with mitomycin C (MMC) is a relatively better treatment modality in the management of eyes with NVG than other glaucoma surgeries. The aim of this study was to investigate the factors that may influence the outcome of trabeculectomy with MMC for NVG.

Methods

Forty-nine NVG eyes from 43 patients (26 males and 17 females) underwent primary trabeculectomy with MMC. The mean follow-up period was 16.8 ± 8.1 months (range, 6 to 34 months). Twenty-one eyes of 21 patients received intravitreal bevacizumab (IVB) 3.6 ± 1.8 days before trabeculectomy with MMC. A Kaplan-Meier survival-curve analysis was used to summarize the cumulative probability of success. We examined the relationship between the surgical outcome and the following surgical factors: gender, age, history of panretinal photocoagulation, history of cataract surgery, history of vitrectomy, preoperative IVB, NVG in the fellow eye, and postoperative complications (hyphema, choroidal detachment, and formation of fibrin) by multivariate analysis.

Results

The survival rate was 83.7% after 6 months, 70.9% after 12 months, and 60.8% after 24 months. The Kaplan-Meier survival curves showed no significant difference in the survival rate between the eyes with preoperative IVB (n = 21) and the eyes without preoperative IVB (n = 28) (p = 0.14). The multiple logistic regression analysis showed that postoperative hyphema (odds ratio, 6.54; 95% confidence interval, 1.41 to 35.97) was significantly associated with the surgical outcome (p = 0.02).

Conclusions

Postoperative hyphema was significantly correlated with the outcome of trabeculectomy for NVG. There was no significant association between preoperative IVB and postoperative hyphema or the results of trabeculectomy.

Expression and activation of toll-like receptor 3 and toll-like receptor 4 on human corneal epithelial and conjunctival fibroblasts

Background

Toll-like receptors (TLRs) are recognized as important contributors to the initiation and modulation of the inflammatory response in the eye. This study investigated the precise expression patterns and functionality of TLRs in human corneal epithelial cells (HCE) and in conjunctival fibroblasts (HCF).

Methods

The cell surface expression of TLRs 2-4, TLR7 and TLR9 in HCE and HCF was examined by flow cytometry with or without stimulation with lipopolysaccharide (LPS) or polyinosinic:polycytidylic acid (poly I:C). The mRNA expression of the TLRs was determined by real-time PCR. The protein content levels of interleukin (IL)-6, IL-8, IL-1β and tumor necrosis factor-α (TNF-α) were measured in HCE and HCF using multiplex fluorescent bead immunoassay (FBI).

Results

The surface expression of TLR3 and TLR4 was detected on both HCE and HCF. Following incubation with LPS, the percentage of HCE cells staining for TLR4 decreased from 10.18% to 0.62% (P < 0.001). Incubation with poly I:C lowered the percentage of HCE cells positive for TLR3 from 10.44% to 2.84% (P < 0.001). The mRNA expression of TLRs2, 4, 7 and 9 was detected in HCE only. Activation of HCE with LPS complex elicited protein secretion up to 4.51 ± 0.85-fold higher levels of IL-6 (P < 0.05), 2.5 ± 0.36-fold IL-8 (P > 0.05), 4.35 ± 1.12-fold IL-1β (P > 0.05) and 29.35 ± 2.3-fold TNFα (P < 0.05) compared to cells incubated in medium.

Conclusions

HCF and HCE both express TLRs that respond to specific ligands by increasing cytokine expression. Following activation, the surface expression of TLR3 and TLR4 on HCE is decreased, thus creating a negative feedback loop, mitigating the effect of TLR activation.

Analysis ofCOCHandTNFAVariants in East Indian Primary Open-Angle Glaucoma Patients

Glaucoma represents a heterogeneous group of optic neuropathies with a complex genetic basis. It is the second-largest cause of blindness in the world that reduces vision without warning and often without symptoms. Among 3 major subtypes of glaucoma, primary open-angle glaucoma (POAG) is the most common form. The focus of this study is to understand the molecular basis of the disease among Indian patients with respect to two genes, Cochlin (COCH) and tumor necrosis factor alpha (TNFA), selected based on reports of possible association with POAG. The genes were screened in patients and controls by PCR and direct sequencing. Although two novel changes (–450 C/T and –79 G/G) were identified in the 5′upstream region of COCH, no causal variant could be identified in either gene. –450 C/T was detected in 3 patients and 2 controls and –79 G/C in a single patient. Further, we did not observe significant association with the promoter SNPs of TNFA that had been previously reported to be associated with POAG pathogenesis. Thus, our study suggests lack of association of both COCH and TNFA with POAG pathogenesis.

Different fibroblast subpopulations of the eye: a therapeutic target to prevent postoperative fibrosis in glaucoma therapy

The aim of this study is the characterization of fibroblasts mainly responsible for fibrosis processes associated with trabeculectomy or microstent implantation for glaucoma therapy. Therefore we isolated human primary fibroblasts from choroidea, sclera, Tenon capsule, and orbital fat tissues. These fibroblast subpopulations were analysed in vitro for expression of the extracellular matrix components which are responsible for postoperative scarring in glaucoma therapy. For scarring the proteins of the collagen family are predominant and so we focused on the expression of collagen I, collagen III and collagen VI in every fibroblast subpopulation. Also, the extracellular matrix protein fibronectin which crosslinks collagen fibres or other extracellular matrix components and cell surfaces, was analyzed. Collagen I, III and VI were prominent in every fibroblast subpopulation. The highest amounts of collagen III were found in hCF and hOF, whereas the signal in hSF and hTF was negligible. Additionally, there is a link between scarring processes and proliferating potential of fibroblasts, in case of microstent implantation triggered through the infiltration of inflammatory cells. Thus we analyzed fibroblast subpopulations for the presence of TGF-β1 which is one of the most important cytokines involved in proliferation processes. TGF-β1 was prominent in all fibroblast subpopulations with lowest expression in hCF cultures. To prevent postoperative fibroblast proliferation we analyzed in vitro the proliferation-inhibitors paclitaxel and mitomycin C which are potential candidates in drug eluting drainage systems on ocular fibroblast subpopulations. These inhibitors arrest fibroblast proliferation and viability, being, however, not very specific and have a cytotoxic potential also on healthy tissues surrounding the microstent outflow area. Significant differences in protein synthesis of fibroblasts subpopulations which could be specific targets for inhibition may help to find out fibroblast specific inhibitors to prevent postoperative scarring and could prevent patients from secondary surgery after microstent implantation.

IL-8, IL-12 and IL-10 cytokines generation by neutrophils, fibroblasts and neutrophils- fibroblasts interaction in psoriasis

PURPOSE

Psoriasis is a common skin disease affecting about 1-3% of the world population. Many types of cells, including lymphocytes, dendritics APCs (antigen presenting cells), NKT (natural killer T) cells, neutrophils, keratinocytes and fibroblasts are involved in the pathogenesis of psoriasis.The aim of our study was to assess in psoriatic patients the production of IL-8, IL-10 and IL-12 cytokines by neutrophils, fibroblasts and fibroblasts - neutrophils interaction.

MATERIAL/METHODS

The production of IL-8, IL-10 and IL-12 cytokines was evaluated in supernatants after cells incubation for 21 h in culture medium alone and in medium in the presence of IL-8 or TNF-α. Concentrations of IL-8, IL-10, IL-12 were measured by enzyme-linked immunosorbent assay (ELISA) method using commercially available kits.

RESULTS

Our results demonstrate that fibroblasts are not able to produce IL-10 and IL-12 but they generate IL-8. The amount of IL-8 depends on the site of derivation of fibroblasts and on the stimuli. Neutrophils released IL-8, IL-12 (at a lower level in psoriatic patients) and IL-10 but only in the case of healthy donors and at a very low concentration. Moreover, we observed higher concentrations of IL-12 and IL-8 in supernatants as a result of fibroblasts-neutrophils interaction in psoriatic patients.

CONCLUSIONS

Our results suggest that fibroblasts take part in the inflammatory reaction in psoriasis via cytokines or direct interaction with neutrophils. Fibroblasts probably do not exert any anti-inflammatory effect.

Inflammatory molecules in aqueous humour and on ocular surface and glaucoma surgery outcome

Purpose. To investigate the influence of inflammatory molecules in the aqueous humour and on the ocular surface on the outcome of glaucoma surgery. Methods. Thirty patients who needed antiglaucomatous surgery were included. The interleukin- (IL-) 8, IL-1β, IL-6, IL-10, tumour necrosis factor- (TNF-) α; and IL-12 were determined from aqueous humour preoperatively and the imprints of conjunctiva were analysed for expression of human leukocyte antigen- (HLA-)-DR after surgery by flow cytometry. The success of trabeculectomy was defined as intraocular pressure less than 21 mmHg without antiglaucoma medication. Results. Eyes with trabeculectomy failure at 3 months showed significantly higher TNF-α and IL-6 levels in the aqueous than eyes with successful surgery. Increased expression of HLA-DR on epithelial cells and antigen-presenting cells was not associated with the trabeculectomy outcome. Conclusions. Higher preoperative levels of TNF-α and IL-6 in aqueous humour may contribute to the development of inflammatory milieu and were associated with worse outcome of glaucoma surgery.

The critical role of the conjunctiva in glaucoma filtration surgery

This review considers the critical role of the conjunctiva in determining the success or failure of glaucoma filtration surgery. Glaucoma filtration surgery can be defined as an attempt to lower intraocular pressure (IOP) by the surgical formation of an artificial drainage pathway from the anterior chamber to the subconjunctival space. Many types of glaucoma filtration surgery have been developed since the first attempts almost 180 years ago. The wide range of new techniques and devices currently under investigation is testament to the limitations of current techniques and the need for improved therapeutic outcomes. Whilst great attention has been paid to surgical techniques and devices to create the drainage pathway, relatively little attention has been given to address the question of why drainage from such artificial pathways is often problematic. This is in contrast to normal drainage pathways which last a lifetime. Furthermore, the consequences of potential changes in aqueous humour properties induced by glaucoma filtration surgery have not been sufficiently addressed. The mechanisms by which aqueous fluid is drained from the subconjunctival space after filtration surgery have also received relatively little attention. We propose that factors such as the degree of tissue damage during surgery, the surrounding tissue reaction to any surgical implant, and the degree of disruption of normal aqueous properties, are all factors which influence the successful formation of long term drainage channels from the conjunctiva, and that these channels are the key to successful filtration surgery. In recent years it has been suggested that the rate of fluid drainage from the subconjunctival space is actually the determining factor in the resultant IOP reduction. Improved knowledge of aqueous humour induced changes in such drainage pathways has the potential to significantly improve the surgical management of glaucoma. We describe for the first time a novel type of drainage surgery which attempts to minimise surgical trauma to the overlying conjunctiva. The rationale is that a healthy conjunctiva allows drainage channels to form and less opportunity for inflammation and scar tissue formation which are a frequent cause of failure in glaucoma filtration surgery. Successful drainage over extended periods of time has been demonstrated in monkey and rabbit eyes. Long lasting drainage pathways were clearly associated with the presence of lymphatic drainage pathways. A new philosophy in glaucoma drainage surgery is proposed in which minimisation of surgical trauma to the conjunctiva and the encouragement of the development of conjunctival drainage pathways, particularly lymphatic pathways, are central pillars to a successful outcome in glaucoma filtration surgery.

Role of conjunctival inflammation in surgical outcome after amniotic membrane transplantation with or without fibrin glue for pterygium

PURPOSE

To determine the clinical significance of postoperative conjunctival inflammation noted at the third or fourth week after intraoperative application of mitomycin C and amniotic membrane transplantation for pterygium.

METHODS

This retrospective study included 27 eyes of 23 patients with primary (n = 12) or recurrent (n = 15) pterygia. All cases were operated by extensive removal of subconjunctival fibrovascular tissue and intraoperative application of 0.04% mitomycin C in the fornix, followed by amniotic membrane transplantation by using either fibrin glue (14 eyes) or sutures (13 eyes). Main outcome measures included development of conjunctival inflammation, pyogenic granuloma, and pterygium recurrence after surgery.

RESULTS

For a follow-up of 29.6 +/- 17.2 months (range, 6-56 months), 16 (59.3%) eyes without postoperative conjunctival inflammation resulted in favorable outcomes. Conjunctival inflammation around the surgical site was noted in the remaining 11 (40.7%) eyes and was significantly more common in eyes with sutures than those with fibrin glue (61.5% vs. 21.4%, respectively; P = 0.05). Among those with this inflammation, 7 eyes receiving subconjunctival injection of triamcinolone resulted in complete resolution and a good aesthetic outcome. Four eyes without this injection gradually developed conjunctival (n = 1) or corneal (n = 1) recurrence and/or pyogenic granuloma (n = 3).

CONCLUSIONS

Host conjunctival inflammation is still common after intraoperative application of mitomycin C and amniotic membrane transplantation, especially when sutures are used in pterygium surgery. If left untreated, persistent inflammation may lead to a poor surgical outcome.

Synergistic effects of combined cytotoxic and apoptosis-inducing drugs on Tenon's capsule fibroblasts in vitro and in vivo

BACKGROUND

Highly toxic antimetabolites have gained access to routine clinical use to modulate and reduce the amount of postoperative scarring following glaucomatous filtering procedures. It could be speculated that by combining two different antiproliferative substances with different mechanisms of action total amounts of the substances could be decreased and side effects reduced.

METHODS

Twenty-two substances were tested that had antiproliferative effects by acting cytotoxically, inhibiting growth factors, or inducing apoptosis. With combinations of each two substances, cell culture experiments using 3T3 and human Tenon's capsule fibroblasts were performed evaluating cell toxicity, proliferation and migration, the extent of free radicals, and the amount of apoptosis (TUNEL, electron microscopy). The five most potent combinations were used in an animal experiment with rabbits performing filtering procedures. The extent of episcleral scarring was evaluated by histopathology.

RESULTS

The results of the various assays revealed consistently strong effects in 5 of the 462 combinations. Of these five combinations, two were highly effective in the rabbit model. Substances with strong effects when applied in combination included staurosporine, mitomycin, and CD95L.

CONCLUSIONS

We found synergistic effects in assays that evaluated different aspects of cell function. The amount of scarring in an animal experiment was inhibited to a level comparable with a high single dose of mitomycin. Combination therapy of two antiproliferative acting substances may be a promising concept.

Investigation of the effects of Chinese medicine on fibroblast viability: implications in wound healing

Diabetes mellitus has been a clinical problem for hundreds of years. Over 194 million people suffer from this disease worldwide. Improper control of diabetes may result in diabetic foot ulcer or even amputation. Granulation formation is an important issue essential for ulcer healing. The CRL-7522 fibroblast cell line and primary fibroblasts from a diabetic foot ulcer patient were used to model the wound healing enhancing activities of two clinically efficacious Chinese herbal formulae, Formula 1 (F1) and Formula 2 (F2) and their component herbs. Results showed that the two formulae and four of their component herbs, Radix Astragali, Radix Rehmanniae, Rhizoma Alismatis and Rhizoma Atractylodis Macrocephalae significantly enhanced CRL-7522 cell viability. However, these component herbs showed compromised effects on the viability of primary fibroblasts cultured from the ulcerous tissue of a diabetic patient. Interestingly, F1 and F2 enhanced the viability of primary cultured fibroblasts from the diabetic patient even in the face of insulin resistance. These results further support the previously reported clinical efficacies of the two formulae on healing diabetic foot ulcers.

Angiogenesis in pterygium: study of microvessel density, vascular endothelial growth factor, and thrombospondin-1

PURPOSE

This retrospective study aims to elucidate the role of angiogenesis in the pathogenesis of pterygium. We evaluated microvessel density (MVD), and expression of vascular endothelial growth factor (VEGF) and thrombospondin-1 (TSP-1).

METHODS

Fifty-two surgically excised pterygia and seven normal conjunctivae were immunohistochemically studied applying the streptavidin-biotin method in paraffin-embedded tissue sections. Monoclonal antibodies were targeted against CD31, VEGF, and TSP-1 proteins.

RESULTS

Pterygium presented with statistically significant higher average count of microvessels compared to normal conjunctivae (17.97+/-8.5 vs5.72+/-5 per high power field, P=0.001). In 24/52 (46.2%) cases of pterygium, high expression levels for VEGF were demonstrated, whereas the mean percentage of VEGF-positive epithelial cells was 58.03%. Furthermore, normal conjunctival presented statistically significant higher expression levels for VEGF in epithelial cells (83.14+/-36.08 vs58.03+/-31.23%, P=0.007). On the contrary, the presence of VEGF immunoreactivity in vascular endothelial and stromal cells was significantly higher in pterygium tissues (P<0.0001). Stromal staining for TSP-1 was detected in only 29/52 (55.8%) of the cases and no correlation with normal conjunctivae was found. Finally, statistically significant positive correlation between MVD values and stromal VEGF expression was found (P=0.049).

CONCLUSION

The angiogenesis-related factors that were studied proved to be highly expressed in pterygium tissue. On the contrary, TSP expression level was low, allowing inducers of angiogenesis to act uninhibited. This phenomenon could provide the pathogenic basis of pterygium formation.

A sequential, multiple-treatment, targeted approach to reduce wound healing and failure of glaucoma filtration surgery in a rabbit model (an American Ophthalmological Society thesis)

PURPOSE

The purpose of this study was to evaluate the concept of targeting mediators of the scarring process at multiple points across the course of bleb failure, in order to prolong bleb survival.

METHODS

There were three linked parts to the experiment. In the first part, a cannula glaucoma filtration surgery (GFS) was performed on 32 New Zealand White (NZW) rabbits, and bleb survival was assessed for six different regimens plus controls by grading bleb height and width. For the second part of the study, the same GFS surgery was performed on an additional 10 NZW rabbits. Two additional filtering blebs were treated with balanced saline solution (BSS), two received mitomycin-C (MMC) (0.4 mg/mL), and for the remaining six, a sequential regimen was given consisting of 200 mmol/L mannose-6-phosphate (M-6-P) solution at the time of surgery, followed by subconjunctival injections of antibody to connective tissue growth factor at days 2 and 4, and Ilomastat, a broad-spectrum matrix metalloproteinase inhibitor, at days 7, 12, and 20 postoperatively. Bleb survival was again assessed. In the final part of the experiment, blebs treated with either BSS, MMC, or the above sequential multitreatment regimen were examined histologically at 14 days postoperatively in three additional NZW rabbits.

RESULTS

All six individual therapies selected resulted in some improvement of bleb survival compared to BSS control. Blebs treated with the new sequential, multitreatment protocol survived an average of 29 days (regression slope, P < .0001 compared to control), those receiving BSS an average of 17 days, and those treated with MMC (0.4 mg/mL) an average of 36 days. The sequential, multitreatment regimen was significantly superior to any of the six monotherapies for time to zero analysis (flattening) of the bleb (P < .002). Histologic examination of the bleb tissues showed a markedly less epithelial thinning, subepithelial collagen thinning, and goblet cell loss in the multitreatment group, when compared with the MMC blebs.

CONCLUSIONS

In a rabbit model of GFS, a sequential, targeted, multitreatment approach prolonged bleb survival compared to BSS controls and decreased bleb tissue morphological changes when compared to those treated with MMC. It is not known whether these findings can be reproduced in humans, and further work is needed to determine an optimum regimen and timing of therapeutic delivery.

APC0576 decreases production of pro-inflammatory chemokine and extracellular matrix by human Tenon's capsule fibroblasts

PURPOSE

To control intraocular pressure in patients treated by trabeculectomy, progressive inflammation, fibroblast proliferation, and the enhanced expression of extracellular matrix (ECM), causes of scar formation at the bleb, must be prevented. Using human Tenon's capsule fibroblasts (TCFs), we examined the effect of APC0576, a suppressor of NF-kappaB-dependent gene activation of human vascular endothelial cells that does not adversely affect cell viability, on the production of pro-inflammatory chemokine and ECM. Its effect on TCF proliferation was also assessed.

METHODS

Enzyme-linked immunosorbent assay was used to detect the pro-inflammatory cytokines IL-8 and MCP-1 in the supernatant of TCFs stimulated with IL-1alpha in the presence or absence of APCO576 and ECM proteins, COOH-terminal peptide of type I procollagen (PIP), fibronectin (FN), and laminin (LN) in supernatants and lysates of TCFs stimulated with IL-1alpha or TGF-beta. The proliferative response of IL-1alpha-stimulated TCFs was examined using the SF formazan solution reaction.

RESULTS

APC0576 significantly suppressed the production by TCFs of IL-8 (p<0.0001), MCP-1(p<0.0001), PIP (supernatants: p<0.0001, cell lysates: p<0.0001), LN (supernatants: p<0.0001, lysates: p<0.0001), and FN (supernatants: p<0.0001, lysates: p<0.0001) as well as their proliferation (p<0.0001).

CONCLUSIONS

APC0576 suppressed pro-inflammatory chemokine and ECM production in TCFs as well as their proliferation. It may represent a novel candidate for the postoperative management of patients treated by trabeculectomy.

Antiglaucoma eye drop pulses--increased interleukin-6 secretion by Tenon's capsule fibroblast cultures

PURPOSE

Long-term antiglaucoma eye drop therapy prior to trabeculectomy is a risk factor for surgical failure resulting from Tenon's capsule fibrosis at the fistula site. The study tested the hypothesis that secretion of the proinflammatory cytokine interleukin (IL)-6 by wounded Tenon's capsule-fibroblasts is elevated by prior long-term antiglaucoma eye drop treatment.

METHODS

Fibroblast cultures were established from Tenon's capsule biopsies during trabeculectomy. Twice daily and for four and a half days, confluent secondary (2-4 passages) cultures were treated (30 minutes at 37 degrees C) with the following drugs (diluted at 1:400-1:100): 0.2% brimonidine-tartrate (Alphagan), 2.0% dorzolamide-HCl (Trusopt), 0.5% timolol-maleate (Timoptic), 2.0% dorzolamide-HCl/0.5% timolol-maleate (Cosopt), 2 and 4% pilocarpine-HCl (Akarpine and Pilocar), 0.005% latanoprost (Xalatan), placebos for Trusopt and Timoptic, and 0.01% benzalkonium chloride. Subsequently, cultures were wounded by removing cells grown on half of each culture dishes along with the medium and conditioned for 20 hours in serum-free growth medium, which was then collected for ELISA for IL-6 (and TNF-alpha and IL-1 beta). Cultures were grown for four additional days to show the maintenance of culture sterility.

RESULTS

Latanoprost, pilocarpine-HCl, and timolol-maleate increased IL-6 levels in the conditioned medium in a dilution factor-dependent manner (P < 0.05, ANOVA). IL-6 concentrations were increased most significantly by latanoprost and were (pg/ml; mean +/- SEM; N = 3 cultures) 186 +/- 37, 187 +/- 33, 295 +/- 46 and 336 +/- 76 in cultures treated at 1:400, 1:250, 1:150, and 1:100 dilutions, respectively, whereas those of six control cultures averaged 80 +/- 9. Benzalkonium chloride, brimonidine-tartrate, dorzolamide-HCl, Cosopt placebo, Timoptic placebo, and dorzolamide-HCl/timolol-maleate did not significantly elevate IL-6 concentrations. IL-1 beta and TNF-alpha were not detected in the medium of control cultures and those treated with pilocarpine (1:200).

CONCLUSIONS

The present study demonstrated for the first time that the level of IL-6 secretion by wounded Tenon's capsule fibroblast cell cultures was increased by repeat pulsing of these cultures with some, but not all, antiglaucoma eye drops prior to wounding.

Evaluation of TNF-α and IL-1β polymorphisms in Taiwan Chinese patients with pterygium

PURPOSE

Pterygium, a complex disease, is associated with ultraviolet radiation, immunoinflammatory process, genetic factors, and virus infection. Ultraviolet radiation induces secretion of proinflammatory cytokines by the ocular surface epithelium, inflammatory cells in the tear fluid, or both. Among these cytokines, tumour necrosis factor (TNF)alpha and interleukin (IL)-1beta activate pterygium body fibroblasts, resulting in a phenotype capable of expressing various proteinases associated with extracellular matrix remodelling, angiogenesis, and fibroblast proliferation, which are important for pterygium formation and recurrence. The genetic factor was proposed to play a role in pterygium formation, but there were few studies to clarify this proposition. For investigating genetic factors, the association between pterygium and TNF-alpha and IL-1beta polymorphisms is evaluated in this study.

METHODS

A total of 128 pterygium patients and 103 volunteers without pterygium were enrolled in this study. Polymerase chain reaction-based analysis was used to resolve the TNF-alpha-308 promoter, IL-1beta-511 promoter, IL-1beta exon 5, and IL-1 receptor antagonist (IL-1 Ra) polymorphisms.

RESULTS

There were no significant differences in the frequency of genotypes and alleles of TNF-alpha-308 promoter, IL-1beta-511 promoter, IL-1beta exon 5, and IL-1 Ra polymorphisms between both groups.

CONCLUSIONS

The correlation between pterygium and TNF-alpha-308 promoter, IL-1beta-511 promoter, IL-1beta exon 5, and IL-1 Ra polymorphisms does not exist and those polymorphisms are not useful genetic markers for pterygium susceptibility. Further studies on other polymorphisms or haplotypes of TNF-alpha and IL-1beta are necessary.

Effect of growth factors on the activation of human Tenon's capsule fibroblasts

PURPOSE

To investigate stimulatory effects of PDGF-AA, PDGF-AB, PDGF-BB, bFGF, IL-1beta, TGF-beta1 and TGF-beta2 on the proliferation and myofibroblast transformation of cultured human Tenon's capsule fibroblasts and to characterize expression of PDGF- and TGF-beta-receptors in these cells.

METHODS

To determine cell proliferation, cell number of 2nd passage cultured human Tenon's capsule fibroblasts was measured before and after addition of growth factors using a computer-based cell counter system. Immunoblotting was used to detect and quantitate alpha-smooth-muscle actin (alpha-SMA) expression. Expression of PDGF- and TGF-beta-receptor mRNA was detected by RT-PCR, expression of the corresponding protein was demonstrated using Western blot.

RESULTS

A significant increase in proliferation (p < or = 0.05) was detected after exogenous stimulation with PDGF-AA (10 ng/ml and 100 ng/ml), PDGF-AB (10 ng/ml and 100 ng/ml), PDGF-BB (10 ng/ml and 100 ng/ml), bFGF (100 ng/ml), IL-1beta (1 ng/ml and 10 ng/ml), TGF-beta1 (0.5 ng/ml) and TGF-beta2 (0.5 ng/ml). Both TGF-beta1 and TGF-beta2 stimulated expression of alpha-SMA in a dose dependent manner with peak activity at a concentration of 50 ng/ml (TGF-beta1) and 500 ng/ml (TGF-beta2). Protein and mRNA of PDGF-receptor type alpha and type beta and TGF-beta-receptors type I, II and III are expressed in cultured human Tenon's capsule fibroblasts.

CONCLUSIONS

The present investigation strongly supports the hypothesis that PDGF-isoforms are major stimulators of proliferation of Tenon's capsule fibroblasts after glaucoma filtering surgery while TGF-beta-isoforms are essential for the transformation of Tenon's capsule fibroblasts into myofibroblasts.

Relationship between Helicobacter pylori infection and glaucoma

OBJECTIVE

To determine the frequency of Helicobacter pylori (H. pylori) infection in glaucoma patients and in anemic control participants.

DESIGN

Prospective, nonrandomized, comparative study.

PARTICIPANTS

The authors investigated 32 patients with chronic open-angle glaucoma (COAG), 9 patients with pseudoexfoliation glaucoma (PEG), and 30 age-matched anemic control participants.

METHODS

Upper gastrointestinal endoscopy was performed to evaluate macroscopic abnormalities, and gastric mucosal biopsy specimens were obtained for the presence of H. pylori infection tested by rapid urease slide test (CLO test) and by Cresyl fast violet staining, Giemsa staining, or both. The presence of gastritis was classified in accordance with the Sydney system by using hematoxylin and eosin stain. In addition, intestinal metaplasia was evaluated with Alcian blue stain. Saliva samples were also tested by CLO. Serum was analyzed for the presence of H. pylori-specific IgG antibodies by enzyme-linked immunosorbent assay.

MAIN OUTCOME MEASURE

Histologic examination for the presence of H. pylori.

RESULTS

In 87.5% of the COAG patients, 88.9% of the PEG patients, and 46.7% of the anemic control participants, H. pylori infection was histologically confirmed (odds ratio, 8.00; chi-square, 11.81; P = 0.0006 and 9.14; chi-square, 5.01; P = 0.02, respectively). H. pylori was detected by urease test: (1) in the gastric mucosa in 71.9% of the COAG patients, in 77.8% of the PEG patients, and in 46.7% of the anemic control participants (P = 0.03 and P > 0.05, respectively); and (2) in the saliva in 37.5% of the COAG patients, in 55.6% of the PEG patients, and in 30% of the anemic control participants (P > 0.05). Sixty-eight percent of glaucoma patients and 30% of anemic control participants were seropositive for H. pylori (P = 0.002). When compared with anemic control participants, glaucoma patients exhibited less often endoscopic normal appearance of gastric mucosa (P = 0.01), and more often antral gastritis (P = 0.0004) or peptic ulcer disease (P = 0.01). Histologic grade 3 gastritis was observed only in the glaucoma patients (P = 0.03).

CONCLUSIONS

H. pylori infection seems more frequent in glaucoma patients. If confirmed, this may indicate either a common factor that causes susceptibilities to both glaucoma and H. pylori infection or that H. pylori may be a causal factor for developing glaucoma.

The role of the immune system in conjunctival wound healing after glaucoma surgery

The immune system has a fundamental role in the development and regulation of ocular healing, which plays an important role in the pathogenesis of most blinding diseases. This review discusses the mechanisms of normal wound healing, describing the animal and fetal wound healing models used to provide further insight into normal wound repair. In particular, conjunctival wound repair after glaucoma filtration surgery will be used to illustrate the contributions that the different components of the immune system make to the healing process. The potential role of macrophages, the possible regulatory effect of lymphocytes, and the important role of growth factors and cytokines in the wound healing reaction are discussed. The significance of the immune system in the pathogenesis of aggressive conjunctival scarring is addressed, particularly assessing the predisposing factors, including drugs, age, and ethnicity. The rationale behind the pharmacological agents currently used to modulate the wound healing response and the effects these drugs have on the function of the immune system are described. Finally, potential new therapeutic approaches to regulating the wound healing response are reported.

Collagen type I and III synthesis by Tenon's capsule fibroblasts in culture: individual patient characteristics and response to mitomycin C, 5-fluorouracil, and ascorbic acid

PURPOSE

This study was performed to better understand the differences between patients in specific components of wound healing as it may pertain to glaucoma filtration surgery, including the use of antimetabolites.

METHODS

Human Tenon's capsule fibroblasts were obtained at the time of glaucoma filtering surgery and established in individual cell cultures from 35 glaucoma patients. The dose-response to 5-fluorouracil (5FU) and mitomycin C (MMC) was determined. The individual cell lines were exposed to the antimetabolites and ascorbic acid with measurement of collagen type I and III production by an ELISA-type dot blot assay. These results were then statistically compared to the individual patient characteristics including age, race, previous surgery and medications, and type of glaucoma.

RESULTS

5-FU had little effect on collagen type I and III production or protein synthesis. MMC had an inhibitory effect on collagen secretion and total protein synthesis with increasing concentration. Photomicrographs of the cells after each treatment condition revealed characteristic morphologic changes when compared to controls. There was a large range of collagen type I and III production with correlation between the amounts of each collagen type secreted in response to the antimetabolites. However, there was no correlation with accepted risk factors for filtration failure.

CONCLUSION

These antimetabolites act similarly on different cell lines in a nonspecific manner. The results suggest that the increased risk of filtration failure due to age, race, diagnosis, and previous conjunctival surgery is not due to differences in secretion of collagen types I and III by Tenon's capsule fibroblasts.

Decorin and suramin inhibit ocular fibroblast collagen production

BACKGROUND

The process of ocular wound healing with respect to glaucomatous filtering procedures is of current interest. Delaying this response in patients could possibly lead to more favorable surgical results. So far, only highly toxic antimetabolites have come into frequent clinical use. The possible efficacy of other groups of substances such as growth factor inhibitors has not yet been examined in vitro.

METHODS

We exposed Tenon's capsule fibroblasts in tissue culture to various concentrations of decorin and suramin. The dose responses of type I and type III collagen to these inhibitors were measured using an ELISA-type dot blot assay. Total cellular protein production was assayed by measuring the incorporation of tritiated leucine.

RESULTS

At a concentration of 10 micrograms/ml, suramin reduced the collagen production by more than 80%. Decorin, at a concentration of 100 micrograms/ml, reduced type I collagen production by about 50% while type III collagen was reduced by 80%. At these concentrations, the total cellular protein production was not inhibited.

CONCLUSIONS

Both suramin and decorin, which specifically inhibit the action of growth factors on target cells, reduce the production of collagen synthesis by Tenon's capsule fibroblasts. This is a specific effect, because total protein production is not influenced. This sets these substances apart from antimetabolites. Decorin and suramin may have clinical relevance in that they appear to interfere with ocular wound healing more specifically than the substances so far frequently used.