Notariale Rosaria, Moriello Claudia, Alessio Nicola, Del Vecchio Vitale, Mele Luigi, Perrone Pasquale, Manna Caterina
Department of Medical, Surgical, Neurological, Metabolic and Aging Sciences, University of Campania "Luigi Vanvitelli", 80138, Naples, Italy.
Department of Experimental Medicine, University of Campania "Luigi Vanvitelli", 80138, Naples, Italy.
Redox Biol. 2025 Jul 21;85:103783. doi: 10.1016/j.redox.2025.103783.
Diabetes is a widespread chronic disease that poses serious health concerns due to its numerous associated complications, including an increased risk of cardiovascular diseases. Under conditions of prolonged hyperglycemia, erythrocytes (RBC) undergo the breakdown of the natural phospholipid asymmetry, triggered by cell surface exposure of phosphatidylserine (PS) associated with increased prothrombotic activity. The aim of the present study was to provide insights into the potential molecular mechanisms underlying, focusing on two phospholipid translocases, ATP-dependent flippase ATP11C and calcium-dependent scramblase PLSCR1. The possible protective effect exerted by the hydroxytyrosol (HT), a powerful phenolic antioxidant present in olive oil, was also tested. Exposure of intact human RBC to high glucose (25-50 mM) results in a dose-dependent increase in PS-exposing RBC, which can be prevented by HT at concentrations as low as 5 μM. Furthermore, our study reveals that PLSCR1 activity is significantly higher under hyperglycemic conditions. In line with this finding, immunocytochemical analysis indicates increased membrane expression of this enzyme. Both alterations can be prevented by HT pre-treatment. Conversely, no variation in ATP11C is observable. Importantly, intracellular calcium measurement reveals a significant rise, suggesting that dysregulation of calcium homeostasis may be a key mechanism underlying both the change in scramblase activity as well as the HT protective effect observed. In this case too, in fact, HT exhibits a protective effect. Accordingly, when cells are exposed to high glucose in a calcium-free medium no variation is observable. Finally, we report that HT is able to prevent glucose-induced alteration in redox balance by reducing ROS formation and the decline in intracellular glutathione, likely due to its high scavenging potential as well as to the proposed recycling process cycle that could regenerate reduced glutathione from its radical. All together our findings point to RBC as an additional target in the management of the cardiovascular complications associated with diabetes and indicate HT as nutritional/nutraceutical strategy for their prevention in diabetic patients.
糖尿病是一种广泛存在的慢性疾病，由于其众多相关并发症，包括心血管疾病风险增加，引发了严重的健康问题。在长期高血糖的情况下，红细胞（RBC）会经历天然磷脂不对称性的破坏，这是由与促血栓活性增加相关的磷脂酰丝氨酸（PS）在细胞表面暴露所触发的。本研究的目的是深入了解潜在的分子机制，重点关注两种磷脂转位酶，即ATP依赖性翻转酶ATP11C和钙依赖性磷脂翻转酶PLSCR1。还测试了橄榄油中存在的一种强大的酚类抗氧化剂羟基酪醇（HT）可能发挥的保护作用。完整的人红细胞暴露于高葡萄糖（25 - 50 mM）会导致暴露PS的红细胞呈剂量依赖性增加，而低至5 μM浓度的HT即可预防这种情况。此外，我们的研究表明，在高血糖条件下PLSCR1的活性显著更高。与此发现一致，免疫细胞化学分析表明该酶的膜表达增加。这两种改变都可以通过HT预处理来预防。相反，未观察到ATP11C有变化。重要的是，细胞内钙测量显示显著升高，这表明钙稳态失调可能是磷脂翻转酶活性变化以及观察到的HT保护作用的关键机制。事实上，在这种情况下HT也表现出保护作用。因此，当细胞在无钙培养基中暴露于高葡萄糖时，未观察到变化。最后，我们报告HT能够通过减少ROS形成和细胞内谷胱甘肽的下降来预防葡萄糖诱导的氧化还原平衡改变，这可能是由于其高清除潜力以及所提出的循环过程，该过程可以从其自由基中再生还原型谷胱甘肽。我们所有的发现都表明红细胞是糖尿病相关心血管并发症管理中的另一个靶点，并表明HT是糖尿病患者预防这些并发症的营养/营养补充策略。
