Effect of high glucose on glycosaminoglycans in cultured retinal endothelial cells and rat retina
Effect of high glucose on glycosaminoglycans in cultured retinal endothelial cells and rat retina
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DOI：
10.1093/glycob/cwac029
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发表时间：
2022-05-12
期刊：
影响因子：
4.3
通讯作者：
Harris, Norman R.
中科院分区：
文献类型：
--
作者：
Kaur, Gaganpreet;Song, Yuefan;Harris, Norman R.
内皮糖萼调节血管通透性，炎症和凝血，并作为一个机械传感器。糖萼的缺失可导致内皮损伤，并导致几种微血管并发症，因此可能促进糖尿病视网膜病变。研究表明，糖尿病患者视网膜糖萼部分缺失，但糖胺聚糖（GAG）组成变化的分子细节很少。因此，我们的研究目的是探讨高血糖对视网膜内皮糖萼糖胺酸的影响。方法从大鼠视网膜微血管内皮细胞（RRMEC）、培养液和视网膜中分离GAG，然后用液相色谱-质谱分析。采用实时定量聚合酶链反应研究GAG生物合成相关酶的mRNA转录物。结果与结论高血压可显著增加硫酸乙酰肝素（HS）、硫酸软骨素（CS）和透明质酸（HA）的脱落。高糖培养的RRMEC单层细胞HS水平无明显变化，但CS和HA水平显著下降。同样，虽然糖尿病大鼠视网膜中的HA降低，但总GAG和CS水平升高。RRMEC中的高脂血症导致参与GAG生物合成的酶（包括EXTL-1，2，3、EXT-1，2、ChSY-1，3和HAS-2，3）的mRNA水平显著增加，这些增加可能是对总体糖萼损失的代偿性反应。糖尿病大鼠的RRMEC和视网膜均表现出葡萄糖诱导的二糖组成和HS和CS的硫酸化的改变，其中硫酸化的改变包括HS上的N，6-O-硫酸化和CS上的4-O-硫酸化。
Introduction The endothelial glycocalyx regulates vascular permeability, inflammation, and coagulation, and acts as a mechanosensor. The loss of glycocalyx can cause endothelial injury and contribute to several microvascular complications and, therefore, may promote diabetic retinopathy. Studies have shown a partial loss of retinal glycocalyx in diabetes, but with few molecular details of the changes in glycosaminoglycan (GAG) composition. Therefore, the purpose of our study was to investigate the effect of hyperglycemia on GAGs of the retinal endothelial glycocalyx. Methods GAGs were isolated from rat retinal microvascular endothelial cells (RRMECs), media, and retinas, followed by liquid chromatography-mass spectrometry assays. Quantitative real-time polymerase chain reaction was used to study mRNA transcripts of the enzymes involved in GAG biosynthesis. Results and Conclusions Hyperglycemia significantly increased the shedding of heparan sulfate (HS), chondroitin sulfate (CS), and hyaluronic acid (HA). There were no changes to the levels of HS in RRMEC monolayers grown in high-glucose media, but the levels of CS and HA decreased dramatically. Similarly, while HA decreased in the retinas of diabetic rats, the total GAG and CS levels increased. Hyperglycemia in RRMECs caused a significant increase in the mRNA levels of the enzymes involved in GAG biosynthesis (including EXTL-1,2,3, EXT-1,2, ChSY-1,3, and HAS-2,3), with these increases potentially being compensatory responses to overall glycocalyx loss. Both RRMECs and retinas of diabetic rats exhibited glucose- induced alterations in the disaccharide compositions and sulfation of HS and CS, with the changes in sulfation including N,6-O-sulfation on HS and 4-O-sulfation on CS.