Chae Eun Kim

Effects of Quercetin in a Mouse Model of Experimental Dry Eye.

Purpose: To evaluate the effect of treatment with quercetin in a mouse model of dry eye. Methods: 0.5% quercetin eye drops were prepared and an experimental dry eye model was induced in NOD.B10.H2b mice through desiccation stress. The mice were divided into 3 groups according to the treatment regimen: the DS 10D group (desiccation stress for 10 days), the phosphate buffered saline (PBS) group, and the quercetin group. Tear volumes and corneal irregularity scores were measured at 3, 5, 7, and 10 days after treatment. Hematoxylin and eosin staining, periodic acid–Schiff staining, and immunohistochemistry were performed at the end of the experiment. Results: The quercetin group had increased tear volumes (0.2 ± 0.03 &mgr;m, P < 0.05) and decreased corneal irregularity scores (0.7 ± 0.6, P < 0.05) compared with those of the PBS group. On histological examination, the quercetin group exhibited restored smooth corneal surfaces without detaching corneal epithelial cells and had significantly increased goblet cell density (13.8 ± 0.8 cells/0.1 mm2, P < 0.05) compared with the PBS group. The quercetin group also exhibited significant declines of MMP-2 (5.1-fold of control, P < 0.01), MMP-9 (2.5-fold of control, P < 0.01), ICAM-1 (2.2-fold of control, P < 0.01), and VCAM-1 (2.3-fold of control, P < 0.01) levels in the lacrimal gland than did the PBS group. Conclusions: Topical application of quercetin can help to improve ocular surface disorders of dry eye not only by decreasing the corneal surface irregularity but also by increasing the tear volume and goblet cell density. Moreover, quercetin has the potential for use in eye drops as a treatment for dry eye disease with antiinflammatory effects on the lacrimal functional unit.

Effects of silk fibroin in murine dry eye

The study aimed to investigate the effects of silk fibroin in a mouse model of dry eye. The experimental dry eye mouse model was developed using more than twelve-weeks-old NOD.B10.H2b mice exposing them to 30–40% ambient humidity and injecting them with scopolamine hydrobromide for 10 days. Tear production and corneal irregularity score were measured by the instillation of phosphate buffered saline or silk fibroin. Corneal detachment and conjunctival goblet cell density were observed by hematoxylin and eosin or periodic acid Schiff staining in the cornea or conjunctiva. The expression of inflammatory markers was detected by immunohistochemistry in the lacrimal gland. The silk group tear production was increased, and corneal smoothness was improved. The corneal epithelial cells and conjunctival goblet cells were recovered in the silk groups. The expression of inflammatory factors was inhibited in the lacrimal gland of the silk group. These results show that silk fibroin improved the cornea, conjunctiva, and lacrimal gland in the mouse model of dry eye. These findings suggest that silk fibroin has anti-inflammatory effects in the experimental models of dry eye.

Therapeutic Efficacy of Nanocomplex of Poly(Ethylene Glycol) and Catechin for Dry Eye Disease in a Mouse Model

Purpose We investigated the possibility of the nanocomplex of poly(ethylene glycol) (PEG) and catechin as a new biomedical material to treat dry eye disease. Methods NOD.B10.H2b mice were exposed to an air draft and injected with scopolamine for 10 days. Ten days later, the mice were treated with normal saline (n = 11), 1% catechin (n = 11), 1% PEG (n = 11), and 1% catechin/PEG nanocomplex solution mixture containing catechin and PEG at weight ratios of 1:1 (CP1, n = 11), 1:5 (CP5, n = 11), and 1:10 (CP10, n = 11). All treatments were administered five times a day for 10 days. We estimated the effect of PEG/catechin nanocomplexes on inflammation, tear production, epithelium stabilization, and goblet cell density. Results Desiccation stress significantly decreased tear production and increased the corneal irregularity score. Furthermore, desiccation stress markedly increased the detached epithelium and decreased the numbers of conjunctival goblet cells. In addition, the expression of proinflammatory-related factors was markedly induced by desiccation stress in the lacrimal glands. However, the PEG/catechin nanocomplex effectively induced an increase in tear production, stabilization of the corneal epithelium, and an increase in conjunctival goblet cells and anti-inflammatory improvements in a PEG dose-dependent manner. Conclusions In this study, we found that PEG may increase bioavailability of catechin. Therefore, the PEG/catechin nanocomplex can be used as a new biomedical material to treat dry eye disease through stabilization of the tear film and inhibition of inflammation.

RGN-259 (thymosin β4) improves clinically important dry eye efficacies in comparison with prescription drugs in a dry eye model.

This study evaluated the clinical activity of RGN-259 (thymosin β4) in comparison with cyclosporine A (CsA), diquafosol (DQS), and lifitegrast (LFA) in a murine model of dry eye. The model was NOD.B10-H2b mice in a 30–40% humidified environment together with daily scopolamine hydrobromide injections for 10 days. After desiccation stress, all drugs were evaluated after 10 treatment days. RGN-259 increased tear production similar to that in the DQS- and LFA-treated mice while CsA was inactive. RGN-259 improved corneal smoothness and decreased fluorescein staining similar to that of LFA group while CsA and DQS were inactive. Corneal epithelial detachment was reduced by RGN-259, and DQS and LFA showed similar activity but the CsA was inactive. RGN-259 increased conjunctival goblet cells and mucin production comparable to that seen with CsA, while DQS and LFA were inactive. RGN-259 reduced the over-expression of inflammatory factors comparable to that with CsA and LFA, while DQS was inactive. RGN-259 increased mucin production comparable to that observed with CsA, while DQS and LFA were inactive. In conclusion, RGN-259 promoted recovery of mucins and goblet cells, improved corneal integrity, and reduced inflammation in a dry eye mouse model and was equal to or more effective than prescription treatments.

Anti-inflammatory effect of hydroxyproline-GQDGLAGPK in desiccation stress-induced experimental dry eye mouse

The purpose of this study has been the investigation of the effect of novel peptide hydroxyproline-GQDGLAGPK (Hyp-GQDGLAGPK) in desiccation stress-induced dry eye mouse model and compared medicines for dry eye disease including cyclosporine, diquafosol and sodium hyaluronate. Seventy eight NOD.B10.H2b mice were injected with scopolamine and exposed to an air draft for 10 days, and then the mice were treated with normal saline (n = 13), 1% Hyp-GQDGLAGPK (n = 13), 0.05% cyclosporine (n = 13), 3% diquafosol (n = 13), and 0.1% hyaluronate (n = 13) for 10 days. Thirteen mice were used for histopathologic analysis at DS 10d. The desiccation stress significantly decreased tear production, but the topical treatment of Hyp-GQDGLAGPK recovered to the baseline levels, which was similar to cyclosporine and diquafosol. In addition, Hyp-GQDGLAGPK improved facilitating epithelium stabilization including the corneal irregularity score, fluorescein score and detachment of the corneal epithelium. These improvements in stabilization of the corneal epithelium was superior to that in the cyclosporine and sodium hyaluronate groups. Furthermore, desiccation stress markedly induced expression of autoimmune inflammation-related factors in the lacrimal glands, but it was significantly suppressed by Hyp-GQDGLAGPK treatment. Overall, we found that novel peptide Hyp-GQDGLAGPK has multi-functional effects such as stabilizing the tear film and inhibiting inflammation.

Erratum: Corrigendum: Effects of silk fibroin in murine dry eye

Scientific Reports 7: Article number: 44364; published online: 10 March 2017; updated: 07 April 2017 This Article contains an error in the Acknowledgements section: “This study was supported by a grant from the Korea Healthcare Technology R&D Project of the Ministry of Health and Welfare Affairs, Republic of Korea (Grant No.