Liu Yang, Kam Wendy R, Fernandes Prabhavathi, Sullivan David A
a Schepens Eye Research Institute, Massachusetts Eye and Ear, and Department of Ophthalmology , Harvard Medical School , Boston , MA , USA.
b Cempra Pharmaceuticals , Chapel Hill , NC , USA.
Curr Eye Res. 2018 Jun;43(6):683-688. doi: 10.1080/02713683.2017.1418894. Epub 2017 Dec 28.
We previously discovered that azithromycin (AZM) acts directly on immortalized human meibomian gland epithelial cells (IHMGECs) to stimulate their lipid and lysosome accumulation and overall differentiation. We hypothesize that this phospholipidosis-like effect is due to AZM's cationic amphiphilic drug (CAD) nature. If our hypothesis is correct, then other CADs (e.g., solithromycin [SOL]) should be able to duplicate AZM's action on IHMGECs. Our purpose was to test this hypothesis.
IHMGECs were cultured in the presence of vehicle or SOL (2, 10, or 20 µg/ml) for up to 7 days under proliferating or differentiating conditions. Positive (epidermal growth factor and bovine pituitary extract for proliferation; AZM for differentiation) and negative (vehicle) controls were included with the experiments. IHMGECs were evaluated for cell number, neutral lipid content, and lysosome accumulation.
Our results demonstrate that SOL induces a rapid and dose-dependent increase in the accumulation of neutral lipids and lysosomes in HMGECs. The lysosomal effects were most prominent with the 10 and 20 µg/ml doses, and occurred earlier (i.e., 1 day) with SOL than with the AZM (10 µg/ml) control. The effects of SOL and AZM on IHMGEC differentiation were essentially the same after 3 days of culture. SOL did not influence the proliferation of HMGECs during a 7-day time period.
Our results support our hypothesis that SOL, a CAD, is able to reproduce AZM's impact on lysosome and lipid accumulation, as well as the differentiation, of HMGECs. The effect of SOL on lysosome appearance was faster than that of AZM.
我们之前发现阿奇霉素（AZM）可直接作用于永生化人睑板腺上皮细胞（IHMGECs），刺激其脂质和溶酶体积累以及整体分化。我们假设这种类磷脂沉积症样效应归因于AZM的阳离子两亲性药物（CAD）性质。如果我们的假设正确，那么其他CADs（例如，索利霉素[SOL]）应该能够复制AZM对IHMGECs的作用。我们的目的是验证这一假设。
在增殖或分化条件下，将IHMGECs在载体或SOL（2、10或20μg/ml）存在的情况下培养长达7天。实验中纳入了阳性对照（用于增殖的表皮生长因子和牛垂体提取物；用于分化的AZM）和阴性对照（载体）。对IHMGECs的细胞数量、中性脂质含量和溶酶体积累进行评估。
我们的结果表明，SOL可诱导HMGECs中中性脂质和溶酶体积累迅速且呈剂量依赖性增加。溶酶体效应在10和20μg/ml剂量时最为显著，且SOL引起溶酶体效应的时间（即1天）早于AZM（10μg/ml）对照组。培养3天后，SOL和AZM对IHMGECs分化的影响基本相同。在7天的时间段内，SOL不影响HMGECs的增殖。
我们的结果支持我们的假设，即CAD类药物SOL能够复制AZM对HMGECs溶酶体和脂质积累以及分化的影响。SOL对溶酶体出现的影响比AZM更快。
