Department of Pharmacology, Physiology, and Neuroscience, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Newark, NJ, 07103, USA.
School of Arts and Sciences, Department of Psychology, Utica College, 1600 Burrstone Road, Utica, NY, 13502, USA.
Neurotox Res. 2018 May;33(4):781-789. doi: 10.1007/s12640-017-9826-6. Epub 2017 Nov 2.
Antibiotics such as gentamicin (an aminoglycoside) and penicillin (a beta-lactam antibiotic) are routinely used in retinal cell and explant cultures. In many cases, these in vitro systems are testing parameters regarding photoreceptor transplantation or preparing cells for transplantation. In vivo, milligram doses of gentamicin are neurotoxic to the retina. However, little is known about the effects of antibiotics to retina in vitro and whether smaller doses of gentamicin are toxic to retinal cells. To test toxicity, retinal cells were dissociated from tiger salamander, placed in culture, and treated with either 20 μg/ml gentamicin, 100 μg/ml streptomycin, 100 U/ml antibiotic/antimycotic, 0.25 μg/ml amphotericin B, or 100 U/ml penicillin G. All dosages were within manufacturer's recommended levels. Control cultures had defined medium only. Cells were fixed at 2 h or 7 days. Three criteria were used to assess toxicity: (1) survival of retinal neurons, (2) neuritic growth of photoreceptors assessed by the development of presynaptic varicosities, and (3) survival and morphology of Mueller cells. Rod cells were immunolabeled for rod opsin, Mueller cells for glial fibrillary acidic protein, and varicosities for synaptophysin. Neuronal cell density was reduced with all pharmacological treatments. The number of presynaptic varicosities was also significantly lower in both rod and cone photoreceptors in treated compared to control cultures; further, rods were more sensitive to gentamicin than cones. Penicillin G (100 U/ml) was overall the least inhibitory and amphotericin B the most toxic of all the agents to photoreceptors. Mueller cell survival was reduced with all treatments; reduced survival was accompanied by the appearance of proportionally fewer stellate and more rounded glial morphologies. These findings suggest that even microgram doses of antibiotic and antimycotic drugs can be neurotoxic to retinal cells and reduce neuritic regeneration in cell culture systems.
庆大霉素（一种氨基糖苷类抗生素）和青霉素（一种β-内酰胺类抗生素）等抗生素通常用于视网膜细胞和外植体培养。在许多情况下，这些体外系统正在测试关于光感受器移植的参数或为移植做准备。在体内，毫克剂量的庆大霉素对视网膜具有神经毒性。然而，对于抗生素在体外对视网膜的影响以及较小剂量的庆大霉素是否对视网膜细胞有毒性知之甚少。为了测试毒性，将虎螈的视网膜细胞分离出来，置于培养物中，并分别用 20μg/ml 庆大霉素、100μg/ml 链霉素、100U/ml 抗生素/抗真菌药、0.25μg/ml 两性霉素 B 或 100U/ml 青霉素 G 处理。所有剂量均在制造商推荐的范围内。对照培养物仅含有定义培养基。细胞在 2 小时或 7 天时固定。使用三种标准来评估毒性：（1）视网膜神经元的存活，（2）通过突触前膨体的发育评估光感受器的神经突生长，以及（3）穆勒细胞的存活和形态。杆状细胞用杆状视蛋白免疫标记，穆勒细胞用神经胶质纤维酸性蛋白标记，膨体用突触素标记。用所有药理处理后，杆状细胞的密度均降低。与对照培养物相比，处理过的培养物中的杆状和锥状光感受器中的突触前膨体数量也明显减少；此外，杆状细胞对庆大霉素比锥状细胞更敏感。青霉素 G（100U/ml）总体上是对光感受器最不抑制的，两性霉素 B 是所有药物中最有毒的。所有处理均降低了穆勒细胞的存活率；存活率降低伴随着星形和圆形胶质形态比例的减少。这些发现表明，即使是微克剂量的抗生素和抗真菌药物也可能对视网膜细胞有毒性，并减少细胞培养系统中的神经突再生。
