The Wound Healing Effect of Doxycycline after Corneal Alkali Burn in Rats.

PURPOSE: To evaluate the wound healing effect of doxycycline and its underlying mechanisms in a rat model of corneal alkali burn. METHODS: Male SD rats were administered 1.0 N NaOH in the right cornea for 25 seconds and randomly divided into the doxycycline group and the control group, with 84 rats in each group. 1.0 g·L-1 doxycycline eye drops (doxycycline group) or vehicle (control group) was topically instilled onto the rat cornea after chemical injury. Three days, 7 days, and 14 days after alkali burn, microscopy was used to observe corneal wound healing by fluorescein staining and the degree of corneal opacity. The expression of transforming growth factor-beta 1 (TGF-ß1) and matrix metalloproteinase-9 (MMP-9) was detected by RT-PCR and ELISA, alpha-smooth muscle actin (a-SMA) levels were measured by immunofluorescent staining, and Western blot assays for TGF-ß1, a-SMA, and nuclear factor-kappa B (NF-κB) were also performed. RESULTS: Corneal wound healing and corneal opacity scores were better in the doxycycline group than in the control group. Three, 7, and 14 days after corneal alkali burn, a significant increase in TGF-ß1 was observed in corneas from the control group, compared with the corneas from the doxycycline group (P < 0.05). The corneal levels of MMP-9 in the doxycycline group were lower than those in the control group 3 days and 7 days after alkali burn (P < 0.05). In addition, doxycycline inhibited α-SMA expression and suppressed NF-κB expression. CONCLUSION: Doxycycline treatment promoted corneal healing and reduced corneal opacity in SD rats. Doxycycline protected the cornea from alkali burn injury by reducing TGF-ß1, MMP-9, NF-κB, and α-SMA expression.

A novel four­snoRNA signature for predicting the survival of patients with uveal melanoma.

Uveal melanoma (UM), the predominant histological subtype of intraocular malignant tumors in adults, often results in high rates of mortality; effective prognostic signatures used to predict the survival of patients with UM are limited. Small nucleolar RNAs (snoRNAs) are emerging as important regulators in the processes of carcinogenesis and tumor progression, but knowledge of their application as prognostic markers in UM is limited. In the present study, the expression profiles of snoRNAs in UM were determined; a total of 60 snoRNAs were notably associated with the overall survival of patients with UM via univariate Cox survival analysis. Subsequently, a prognostic signature based on four snoRNAs was proposed, which retained their prognostic significance determined by a multivariate Cox survival analysis. The formula is as follows: ACA17 * (­1.602) + ACA45 * 0.803 + HBII­276 * 0.603 + SNORD12 * 1.348. Furthermore, the results of in silico analysis indicated that perturbation of the phototransduction, GABAergic synapse and amphetamine addiction pathways may be the potential molecular mechanisms underlying the poor prognosis of patients with UM. Collectively, the present study proposed a potential prognostic signature for patients with UM and the prospective mechanisms at the genome­wide level were determined.

[Inhibitory effects of doxycycline on argyrophilic nucleolar organizing regions and a-smooth muscle actin expression in proliferative bovine corneal myofibroblasts in vitro].

OBJECTIVE: To investigate the effect of doxycycline on the nucleolar organizing regions and a-smooth muscle actin expression in bovine corneal myofibroblasts in vitro and assess its contribution to ocular surface repair mechanisms. METHODS: Cell culture and identification: bovine corneal fibroblasts were cultured after the stroma was incubated in 1.0 and 2.0 g/L type I collagenase in two stages.Isolated cells were plated at mantaryay culture flask in 10% of BSA RPMI-1640. Vimentin and alpha-smooth muscle actin (α-SMA) organization were evaluated by immunocytochemistry. The cells staining positive for Vimentin and α-SMA indicated the presence of corneal myofibroblasts. Bovine corneal myofibroblasts were treated with different concentrations of doxycycline (10, 20, 40, 60, 80 mg/L) , a bland control group and the dexamethasone group (120 mg/L) were set up, each group had 30 cases. The argyrophilic nucleolar organizing regions (AgNOR) staining and the immunohistochemistry for α-SMA were performed when the cells were treated for 24 hours and 48 hours. The AgNOR count (Ag-c), AgNOR area (Ag-a) and the expression of α-SMA in the bovine corneal myofibroblasts among each experiment group and control group were compared using one-way ANOVA, further pairwise comparisons using Independent-Samples t test. RESULTS: Cell culture techniques were successfully used to establish a method for the isolation and culture of bovine corneal myofibroblasts. Microscopic examination and immunohistochemical staining confirmed that the cells cultured were bovine corneal myofibroblasts. The Ag-c and Ag-a of bovine corneal myofibroblasts progressively decreased as the concentrations of doxycycline was increase. 24 h:bland control group Ag-c was 6.40 ± 0.6, 60 mg/L doxycycline group Ag-c was 2.23 ± 0.43;bland control group Ag-a was (34.80 ± 2.36) µm(2), 60 mg/L doxycycline hormone group Ag-a was (19.91 ± 2.15) µm(2). 48 h: bland control group Ag-c was 7.27 ± 0.6,60 mg/L doxycycline hormone group Ag-c was 2.80 ± 0.76, bland control group Ag-a was (36.27 ± 1.99) µm(2), 60 mg/L doxycycline group Ag-a was (13.75 ± 2.09) µm(2). The differences were statistically significant: in the same time intervention (FAg-c 24 h = 252.55, FAg-a 24 h = 202.16, P < 0.05, FAg-c 48 h = 169.38, FAg-a 48 h = 853.23, P < 0.05), in the same concentrations intervention (tAg-c = 6.98, tAg-a = 11.62, P < 0.05). And 60 mg/L of doxycycline had an obviously inhibitory action as 120 mg/L dexamethasone in the same treated hours (dexamethasone group Ag-a 24 h = 30.56 ± 3.66, dexamethasone group Ag-a 48 h = 28.35 ± 1.23 ),the differences were not statistically significant (tAg-a 24h = 1.182, P = 0.242,tAg-a 48 h = 0.21, P = 0.832). As the concentrations investigated, doxycycline can inhibit the expression of α-SMA in the bovine corneal myofibroblasts (189.90 ± 7.48, 140.20 ± 7.79, 113.20 ± 8.98, 98.00 ± 3.50, 85.50 ± 4.99), the difference was statistically significant (F = 761.79, P = 0.00). While dexamethasone had no significant role in the expression of α-SMA (bland control group was 225.10 ± 6.74, the dexamethasone group was 228.50 ± 7.12), and the statistically difference was not obvious (t = 1.096, P = 0.287). CONCLUSIONS: As the concentrations of doxycycline was increased from 10 mg/L to 80 mg/L, the AgNOR count and AgNOR area of bovine corneal myofibroblasts can be significantly reduced in vitro. Compared with dexamethasone, doxycycline significantly suppressed the expression of α-SMA in bovine corneal myofibroblasts in a dose-dependent positive trend.

[Keratoplasty in the management of Terrien's marginal degeneration].

OBJECTIVE: To evaluate the efficacy and safety of keratoplasty combined with corneal foci resection in the treatment of Terrien's marginal degeneration (TMD). METHODS: In this nonrandomized retrospective case series, the records of 48 eyes from 40 patients with TMD who received keratoplasty from January 1995 to December 2005 in Zhongshan Ophthalmic Center were reviewed retrospectively. Orbscan topography examination was undertaken in 8 eyes of 8 patients and the refractive error of 9 eyes from 9 patients was tested before and after the operation. RESULTS: The mean age of the patients was (30 +/- 6) years old. The mean follow up period was (7 +/- 6) years. It took (3 +/- 1) months postoperatively to obtain a stable visual acuity. Before operation, the naked eye and best corrected visual acuity (VA) (Q25,Q75) were (0.05,0.4), and (0.1,0.5), respectively, while improved to (0.2,0.6) and (0.4,0.7) after operation, respectively (Z = 4.63, 3.85, both P<0.01). VA was improved in 39 eyes (81.3%), remained at the same level in 4 eyes (8.3%), decreased 1-2 lines in 3 eyes (6.3%), and decreased more than 2 lines in 2 eyes (4.1%) after the operation. The median spherical diopter and cylinder diopter were (-2.00 D, -8.50 D) and (2.50 D,12.00 D) before operation, while decreased to ( -1.25 D, -4.75 D) and (0.75 D, 4.25 D) after operation (Z= 2. 49, 2.54, P = 0.01, 0.01). The improvement in Sim K's astigmatism, astigmatism in 3 mm zone and mean power in 3 mm and 5 mm zone were reduced statistically significant after the operation (P <0.05); with the exception of astigmatism in the 5 mm zone, which was not reduced significantly after the operation (Z = 1.86, P = 0.06) . The operative complications included corneal perforation during operation in 5 eyes (10.4%), hydrops between graft and recipient interface in 8 eyes (16.7%), epithelial in-growth in 4 eyes (8.3%), choroidal detachment in 1 eye (2.1%), graft rejection in 7 eyes (14.6%), and recurrence in 3 eyes (6.3%). Secondary surgery was required in 5 eyes (10.4%) for interface hydrops, epithelial in-growth and recurrence of TMD. CONCLUSIONS: Keratoplasty combined with foci resection is effective and safe in the treatment of TMD. This procedure can preserve and improve the visual activity.