Tear Matrix Metalloproteinases and Myeloperoxidase Levels in Patients With Boston Keratoprosthesis Type I

Metalloproteinase-9 in the ocular surface of patients with implanted Boston type 1 keratoprosthesis

PURPOSE

To characterize the presence of ocular surface inflammation, using matrix metalloproteinase 9 (MMP-9) as a marker, in the ocular surface of eyes with implanted Boston Keratoprosthesis type 1 (KPro).

METHODS

Patients with implanted KPro at a single tertiary center were recruited to assess ocular inflammation. MMP-9 was measured using InflammaDry^® test in both eyes of each patient. The non-KPro eye served as control. Rate of positivity of MMP-9 was compared between groups. Possible associations between ocular surface inflammation and the development of postoperative complications were evaluated using univariate statistical analysis.

RESULTS

Fifty eyes from 25 patients were included. The mean age was 50 years old. Non-inflammatory indications for KPro were predominant among patients. Eighty eight percent of KPro eyes had a positive test for MMP-9 while only 25% of control eyes were positive (p<001). The most common complications were retroprosthetic membrane, epithelial defects, and sterile corneal melt. The presence of a strong positive result was associated to a higher frequency of complications (80% of eyes) compared to a faint positive test (54%) and a negative test (33%).

CONCLUSION

The KPro device appears to increase MMP-9 levels in the ocular surface. High MMP-9 levels may be associated with higher risk of complications. MMP-9 testing can be useful to assess subclinical ocular surface inflammation with a potential role in the postoperative care of KPro patients.

Recombinant Human Clusterin Seals Damage to the Ocular Surface Barrier in a Mouse Model of Ophthalmic Preservative-Induced Epitheliopathy

There is a significant unmet need for therapeutics to treat ocular surface barrier damage, also called epitheliopathy, due to dry eye and related diseases. We recently reported that the natural tear glycoprotein CLU (clusterin), a molecular chaperone and matrix metalloproteinase inhibitor, seals and heals epitheliopathy in mice subjected to desiccating stress in a model of aqueous-deficient/evaporative dry eye. Here we investigated CLU sealing using a second model with features of ophthalmic preservative-induced dry eye. The ocular surface was stressed by topical application of the ophthalmic preservative benzalkonium chloride (BAC). Then eyes were treated with CLU and sealing was evaluated immediately by quantification of clinical dye uptake. A commercial recombinant form of human CLU (rhCLU), as well as an rhCLU form produced in our laboratory, designed to be compatible with U.S. Food and Drug Administration guidelines on current Good Manufacturing Practices (cGMP), were as effective as natural plasma-derived human CLU (pCLU) in sealing the damaged ocular surface barrier. In contrast, two other proteins found in tears: TIMP1 and LCN1 (tear lipocalin), exhibited no sealing activity. The efficacy and selectivity of rhCLU for sealing of the damaged ocular surface epithelial barrier suggests that it could be of therapeutic value in treating BAC-induced epitheliopathy and related diseases.

Total extract of Anemarrhenae Rhizoma attenuates bleomycin-induced pulmonary fibrosis in rats

Pulmonary fibrosis is a progressive interstitial lung disease with poor prognosis. Anemarrhenae Rhizoma is a traditional Chinese herbal medicine and has been applied in clinical practice for a long history. Recently, components of Anemarrhenae Rhizoma were reported to possess anti-inflammatory and immunomodulatory features; however, the effect of them on pulmonary fibrosis remains unknown. In this study, we explored the therapeutic effect of total extract of Anemarrhenae Rhizoma (TEAR) on bleomycin-induced pulmonary fibrosis. Pulmonary fibrosis rat model was established by a single intratracheal instillation of bleomycin, three doses of TEAR were intragastrically administered for consecutive 28 days. Subsequent to sacrificing of rats, pulmonary fibrosis was observed in rats treated with bleomycin, but administration of TEAR attenuated lung fibrosis, as evidenced by the improved lung histopathological damage and decreased weight loss and lung index. Moreover, TEAR treatment inhibited the inflammatory response in lung fibrosis, which was shown by the reduced nitrogen oxide level and myeloperoxidase activity. Furthermore, TEAR modulated the redox balance in lung tissue by alleviated lipid peroxidation and enhanced enzymatic antioxidants activity. Meanwhile, TEAR protected the rats from fibrosis in a dose-dependent manner, and the anti-fibrotic activity of TEAR may be related to the modulation of TGF-β1/Smad signaling pathway. Collectively, TEAR alleviates bleomycin-induced pulmonary fibrosis, indicating perspectives for development of a potential agent for lung fibrosis therapy.

Tear Film Cytokine Profile of Patients With the Boston Keratoprosthesis Type 1: Comparing Patients With and Without Glaucoma

Purpose

Inflammatory cytokines are involved in glaucoma pathogenesis. The purpose is to compare cytokine levels in the tear film of Boston keratoprosthesis (KPro) patients with and without glaucoma, relative to controls, and correlate levels with clinical parameters.

Methods

This cross-sectional study enrolled 58 eyes (58 patients): 41 KPro eyes with glaucoma, 7 KPro eyes without glaucoma, and 10 healthy controls. Twenty-seven cytokines were measured by multiplex bead immunoassay. Intraocular pressure (IOP), cup-to-disk ratio (CDR), retinal nerve fiber layer, visual acuity, topical medications, and angle closure were assessed in all KPro eyes. Cytokine levels between groups were analyzed by nonparametric tests, and correlations with clinical parameters by Spearman's test.

Results

Levels of TNF-ɑ, IL-1β, FGF-basic, and IFN-ɣ were significantly higher in KPro with glaucoma compared to KPro without (P = 0.020; 0.008; 0.043; 0.018, respectively). KPro groups had similar characteristics and topical antibiotic/steroid regimen. Levels of IL-1Ra, IL-15, VEGF, and RANTES were significantly higher in KPro with glaucoma compared to controls (P < 0.001; = 0.034; < 0.001; = 0.001, respectively). IL-1β and IFN-ɣ levels were positively correlated with CDR (r = 0.309, P = 0.039 and r = 0.452, P = 0.006, respectively) and IOP (r = 0.292, P = 0.047 and r = 0.368, P = 0.023, respectively). TNF-α and FGF-basic levels were positively correlated with CDR (r = 0.348, P = 0.022 and r = 0.344, P = 0.021, respectively).

Conclusions

TNF-α, IL-1β, FGF-basic, IFN-ɣ are elevated in tears of KPro patients with glaucoma and correlate with CDR and IOP. These results show, for the first time in humans, concordance with documented elevations of TNF-α and IL-1β in the murine KPro model. Ocular surface inflammation may reflect inflammatory processes of KPro glaucoma.

Microporous Drug Delivery System for Sustained Anti-VEGF Delivery to the Eye

Purpose

To describe a novel microporous drug delivery system (DDS) for sustained anti- vascular endothelial growth factor (VEGF) delivery to the eye and to evaluate its efficacy in a corneal injury model.

Methods

A macro-porous DDS (1.5 × 1.5 × 4 mm) loaded with 2 mg of bevacizumab was implanted subconjunctivally in three Dutch-belted pigmented rabbits after corneal alkali injury (2N NaOH). Three rabbits received sham DDS. Animals were followed for three months and assessed in vivo and ex vivo for corneal neovascularization (NV), epithelial defect, stromal scarring, endothelial cell loss, and expression of angiogenic and inflammatory markers in the cornea and retina.

Results

Anti-VEGF DDS treatment led to complete inhibition of superior cornea NV and complete corneal re-epithelialization by day 58 whereas sham DDS resulted in severe cornea NV and persistent epithelial defect (9%∼12% of total cornea area) through the end of the study. Histologically, anti-VEGF DDS significantly reduced CD45⁺ and F4/80 CD11b⁺ cell accumulation (79%, P < 0.05) in the cornea, ameliorated tumor necrosis factor–α expression (90%, P < 0.05), reduced corneal stromal scarring and prevented corneal endothelial cell loss, as compared to sham DDS. Moreover, anti-VEGF DDS achieved retinal penetration and reduction in retinal VEGF levels at 3 months.

Conclusions

Use of subconjunctival anti-VEGF DDS suppresses cornea NV, inflammation, stromal scarring, prevents endothelial cell loss, and abrogates retinal VEGF upregulation in a rabbit corneal alkali burn model. Moreover, it delivers anti-VEGF antibodies to the retina for three months. This delivery platform could enable antibody therapy of other corneal and retinal vascular pathologies.

Translational Relevance

We describe a method for sustained anti-VEGF delivery to the eye for the treatment of ocular injuries.

Syzygium aromaticum aqueous extract inhibits human neutrophils myeloperoxidase and protects mice from LPS-induced lung inflammation

CONTEXT

Syzygium aromaticum (L.) Merr. & Perry (Myrtaceae), commonly known as clove, originally found in the Muluku Islands in East Indonesia, is widely used as a spice and has numerous medicinal properties.

OBJECTIVE

This study investigated the antioxidant potential of S. aromaticum aqueous extract (SAAE) in vitro and its protective effects on lipopolysaccharide (LPS)-induced lung inflammation in mice.

MATERIAL AND METHODS

Neutrophils were isolated from healthy donors and reactive oxygen species (ROS) generation was measured by luminol-amplified chemiluminescence. Superoxide anion generation was detected by cytochrome c reduction assay. H₂O₂ was detected by DCFH fluorescence assay. Myeloperoxidase (MPO) activity was mesured by tetramethyl benzidine oxidation method. To study the anti-inflammatory activity of SAAE, lung inflammation was induced in mice (BALB/c) by intra-tracheal instillation of lypopolysaccharide (5 µg/mouse), and SAAE (200 mg/kg body weight) was injected intraperitoneally prior to LPS administration. Bronchoalveolar lavage and lung tissue were collected to assess inflammatory cells count and total protein content. Metalloproteinases activity was detected by zymography technique.

RESULTS

SAAE inhibited luminol-amplified chemiluminescence of resting neutrophils and N-formyl-methionyl-leucyl-phenylalanine- or phorbol myristate acetate-stimulated neutrophils, with an inhibitory effect starting at a concentration as low as 0.5 µg/mL. Moreover, SAAE reduced significantly MPO activity and it exhibits a dose-dependent action (IC₅₀ = 0.5 µg/mL). In vivo results showed that SAAE decreased markedly neutrophil count (From 61% to 15%) and proteins leakage into bronchoalveolar lavage fluid. Gelatin zymography assay showed that S. aromaticum inhibited MMP-2 (15%) and MMP-9 (18%) activity in lung homogenates.

DISCUSSION AND CONCLUSION

Our results suggest that the anti-inflammatory activity of SAAE, in vivo, is due to the inhibition of ROS production and metalloproteinases activity via its action on MPO. According to these findings, SAAE could be a potential source of new compounds with anti-inflammatory activity.

Clusterin from human clinical tear samples: Positive correlation between tear concentration and Schirmer strip test results

PURPOSE

To investigate the relationship between tear concentration of the homeostatic protein clusterin (CLU) and dry eye signs and symptoms, and to characterize tear CLU protein.

METHODS

Two independent studies were conducted, one in Tucson (44 subjects), the other in Los Angeles (52 subjects). A cohort study design was employed to enroll patients without regard to dry eye diagnosis. Dry eye signs and symptoms were assessed using clinical tests. Tear samples were collected by Schirmer strip, and also by micropipette at slit lamp when possible. CLU from both sample types was quantified by immunoassay. The relationship between CLU concentration and clinical test scores was determined by Pearson's correlation coefficient (for individual eyes) and multiple linear regression analysis (including both eyes). CLU was also evaluated biochemically by western blotting.

RESULTS

In the Tucson cohort, a positive correlation was observed between tear CLU concentration and results of the Schirmer strip test, a measure of tear flow (p = 0.021 includes both eyes). This result was corroborated in the Los Angeles cohort (p = 0.013). The mean tear CLU concentration was 31 ± 14 μg/mL (n = 18 subjects, 33 eyes; range = 7-48 μg/mL). CLU from clinical tear samples appeared biochemically similar to CLU from a non-clinical tear sample and from blood plasma.

CONCLUSIONS

Results support the hypothesis that an optimal concentration of tear CLU is important for ocular surface health, and that this drops below the effective threshold in dry eye. Tear CLU measurement might identify patients that could benefit from supplementation. Information about concentration will aid development of therapeutic dosage parameters.

Corneal Melt after Boston Keratoprosthesis: Clinical Presentation, Management, Outcomes and Risk Factor Analysis

PURPOSE

To determine the presentation, risk factors, and outcomes of keratolysis after Boston type I keratoprosthesis (B-KPro).

METHODS

Retrospective chart review.

RESULTS

A total of 16 (14%) of the 110 eyes (96 patients) which underwent B-KPro implantation developed keratolysis at an average 20 ± 11 months. Retroprosthetic membrane (RPM), infectious keratitis, and corneal dellen were identified in 31%, 25%, and 13% of corneal melts, respectively. Five eyes had keratolysis without a readily identifiable cause. RPM (odds-ratio, OR = 4.4, p = 0.02) and infectious keratitis (OR = 17.6, p<0.0005) were confirmed as significant risk factors. Retinal detachment (p = 0.001) and choroidal detachment (p = 0.003) were more common in eyes with keratolysis. Management included B-KPro removal or exchange (n = 7), amniotic membrane transplantation (n = 1), tectonic corneal transplantation (n = 2), medical treatment (n = 4), and observation (n = 2).

CONCLUSIONS

The risk of keratolysis following B-Kpro increases with the development of RPM and infectious keratitis. Patients with keratolysis had higher complication rates and should receive rigorous monitoring.