Mimetogen Pharmaceuticals, Montreal, Quebec, Canada.
Exp Eye Res. 2011 Oct;93(4):503-12. doi: 10.1016/j.exer.2011.06.014. Epub 2011 Jun 25.
The aim of this study was to evaluate the efficacy of MIM-D3, a small molecule nerve growth factor (NGF) peptidomimetic, as a therapeutic agent in rats with scopolamine induced dry eye. NGF plays an important role in ocular surface maintenance and corneal wound healing and was recently shown to have mucin secretagogue activity in conjunctival cells. We investigated whether MIM-D3 increased glycoconjugate secretion in conjunctival cells in vitro and in rat tear fluids in vivo. Primary rat conjunctival cell cultures were treated with increasing concentrations of MIM-D3 and evaluated for glycoconjugate secretion, proliferation and MAPK1/2 activation. Glycoconjugates were quantitated in tear fluids from normal rats treated topically with increasing doses of MIM-D3 (0.4%, 1% and 2.5%). Dry eye was induced in rats by subcutaneous scopolamine treatment, administered by surgically implanted osmotic pumps for 14 or 28 days. Aqueous tear production, tear clearance, fluorescein corneal staining and tear break-up time (tBUT) were evaluated. Glycoconjugates and NGF were quantitated in the tear fluids by enzyme-linked lectin assay (ELLA) and enzyme-linked immunosorbant assay (ELISA), respectively. We found that 50 μM MIM-D3 statistically significantly induced a 1.3-fold increase in glycoconjugate secretion and a 2.3-fold increase in MAPK1/2 activation without increasing proliferation from conjunctival cell cultures. Application of 2.5% MIM-D3 in normal rat eyes statistically significantly increased tear glycoconjugate concentration by 2.3-fold. In the experimental dry eye model, application of 1% MIM-D3 to rat eyes for either 1 or 17 consecutive days, followed by 1 week of no dosing produced a statistically significant decrease in corneal staining (p < 0.001), a slight increase in tBUT, and increases in tear glycoconjugates (p < 0.05) compared to vehicle. Scopolamine treatment also caused a statistically significant increase of endogenous NGF in tears (p < 0.005). We concluded that the increase in glycoconjugate concentration by the 1% MIM-D3 dose may have improved the quality and stability of the tear film, and thereby improved healing on the ocular surface in dry eye. Therefore, MIM-D3 may have therapeutic potential as a topical agent for the treatment of dry eye.
本研究旨在评估小分子神经生长因子（NGF）类似物 MIM-D3 作为一种治疗药物在东莨菪碱诱导的干眼症大鼠中的疗效。NGF 在眼表面维持和角膜愈合中起重要作用，最近研究表明其具有结膜细胞中粘蛋白分泌激动剂的活性。我们研究了 MIM-D3 是否能增加体外结膜细胞和体内大鼠泪液中的糖缀合物分泌。用递增浓度的 MIM-D3 处理原代大鼠结膜细胞培养物，并评估糖缀合物分泌、增殖和 MAPK1/2 激活情况。用递增剂量的 MIM-D3（0.4%、1%和 2.5%）局部处理正常大鼠，定量检测其泪液中的糖缀合物。通过手术植入的渗透泵皮下给予东莨菪碱处理诱导大鼠干眼症，持续 14 或 28 天。评估基础泪液分泌、泪液清除率、荧光素角膜染色和泪膜破裂时间（tBUT）。通过酶联凝集素测定法（ELLA）和酶联免疫吸附测定法（ELISA）分别定量检测泪液中的糖缀合物和 NGF。我们发现，50 μM MIM-D3 可统计学显著诱导糖缀合物分泌增加 1.3 倍，MAPK1/2 激活增加 2.3 倍，而不会增加结膜细胞培养物的增殖。2.5% MIM-D3 应用于正常大鼠眼睛，可统计学显著增加泪液糖缀合物浓度 2.3 倍。在实验性干眼症模型中，1% MIM-D3 连续 1 天或 17 天应用于大鼠眼睛，然后停药 1 周，与载体相比，可统计学显著降低角膜染色（p<0.001），泪膜破裂时间略有增加（p<0.05），并增加泪液糖缀合物（p<0.05）。东莨菪碱处理还导致泪液中内源性 NGF 统计学显著增加（p<0.005）。我们得出结论，1% MIM-D3 剂量增加糖缀合物浓度可能改善了泪膜的质量和稳定性，从而改善了干眼症眼表面的愈合。因此，MIM-D3 可能具有作为干眼症治疗的局部治疗剂的治疗潜力。
