Institute of Scientific Research, Hans Selye, Querétaro, Qro., Mexico.
Department of Embriology, Faculty of Medicine, BUAP, Puebla, Mexico.
Int J Vitam Nutr Res. 2021 Sep;91(5-6):491-499. doi: 10.1024/0300-9831/a000650. Epub 2020 Mar 31.
Although thiamine pyrophosphate (TPP) is considered a protective agent for endothelial cells, it is still unknown if this is associated with nitric oxide (NO) synthesis. Our aim was to evaluate the synthesis of NO in endothelial cells incubated with TPP and high glucose concentrations. Endothelial cells from the umbilical cord vein from newborns (n = 20), were incubated with 5, 15 or 30 mmol/L glucose, in absence or presence of 0.625 mg/ml of TPP. Our results showed a significant increase in cell proliferation (> 40%; P < 0.05), and cell viability (> 90%; P < 0.001) after 48 h in endothelial cells cultured with glucose plus TPP. Likewise, in the presence of glucose and TPP an important rise in the consumption of glucose by the endothelial cells was observed after 24 h (> 7%; P < 0.001) and 48 h (> 10%; P < 0.05). Additionally, the levels of lactate after incubation with glucose and TPP showed only slight variations after 48 h (P < 0.05). However, these changes were clearly different from those observed in the absence of TPP. Interestingly, we found that the changes mentioned were linked with reduced levels of nitrites both at 24 h (< 171 pmol/μg protein; P < 0.001), and 48 h (< 250 pmol/μg protein; P < 0.05), which was associated with a reduced expression of mRNA of eNOS in endothelial cells incubated with TPP and high glucose. In conclusion, the presence of TPP regulates the consumption of glucose and the synthesis of NO, which would explain its protective effect in the endothelium of diabetic patients.
尽管焦磷酸硫胺素（TPP）被认为是内皮细胞的保护剂，但目前尚不清楚这是否与一氧化氮（NO）的合成有关。我们的目的是评估内皮细胞在 TPP 和高葡萄糖浓度孵育下 NO 的合成。从新生儿脐带静脉中分离出内皮细胞（n=20），在 5、15 或 30mmol/L 葡萄糖存在或不存在 0.625mg/ml TPP 的情况下孵育。结果显示，在 TPP 存在的情况下，内皮细胞在 48 小时时细胞增殖（>40%；P<0.05）和细胞活力（>90%；P<0.001）显著增加。同样，在葡萄糖和 TPP 存在的情况下，内皮细胞在 24 小时后观察到葡萄糖消耗显著增加（>7%；P<0.001），在 48 小时后观察到葡萄糖消耗显著增加（>10%；P<0.05）。此外，在与葡萄糖和 TPP 孵育 48 小时后，乳酸水平仅略有变化（P<0.05）。然而，这些变化与 TPP 缺乏时观察到的变化明显不同。有趣的是，我们发现，24 小时时（<171pmol/μg 蛋白；P<0.001）和 48 小时时（<250pmol/μg 蛋白；P<0.05）亚硝酸盐水平的降低与内皮细胞中 eNOS mRNA 表达减少有关，内皮细胞在 TPP 和高葡萄糖存在的情况下被孵育。总之，TPP 的存在调节了葡萄糖的消耗和 NO 的合成，这可以解释其在糖尿病患者内皮中的保护作用。
