Bermejo Nuria, López José Javier, Berna-Erro Alejandro, Fernández Esperanza, Corbacho Antonio Jesús, Vázquez Maria Teresa, Granados Maria Purificación, Redondo Pedro Cosme
Department of Hematology, Hospital San Pedro de Alcántara, 10005 Cáceres, Spain.
Department of Physiology, University of Extremadura, 10003 Cáceres, Spain.
Int J Mol Sci. 2025 Oct 14;26(20):9999. doi: 10.3390/ijms26209999.
STC2 (stanniocalcin 2) controls calcium (Ca) homeostasis in human platelets and other cell lines. The regulation of intracellular Ca homeostasis is crucial for platelet activation; thus, the alteration in intracellular Ca concentration or the mechanism involved in its regulation has been proposed to underlie some thrombotic disorders. Our previous studies evidenced that the knockdown of STC2 altered murine platelet activation; furthermore, a reduction in STC2 expression resulted in enhanced Ca homeostasis in diabetic patients and, therefore, would contribute to the prothrombotic condition as a hallmark of diabetes mellitus type 2 (DM2). In this study, we examine a possible link between the expression of stanniocalcins (STCs) and different thrombotic events in humans. The expression of STCs was determined by Western blotting (WB); meanwhile, the analysis of protein interaction and phosphorylation was performed by completing a previous immunoprecipitation protocol (IP) of the proteins of interest. Thus, our results from patients with stroke/ictus presented a clear reduction in STC2 expression in their platelets, finding less STC2 content in the youngest thrombotic patients. Furthermore, acetyl-salicylic acid (ASA) administration reversed the decrease in the expression of STC2 in patients who did not suffer additional thrombotic episodes, as evidenced by the longitudinal analysis of up to 10 years of follow-up. Additionally, the increase in STC2 phosphorylation at the serine residues revealed increased activity of STC2 in thrombotic patients. Finally, we suggest that store-operated Ca entry (SOCE) is over-activated in patients suffering from stroke/ictus, as revealed by the increase in the STIM1/Orai1 interaction found under resting conditions and, further, because MEG-01 cells transfected with siRNA STC2 to evoke artificial reduction in the STC2 expression presented an increased SOCE with respect to the control cells transfected with siRNA A. Conversely, the expression of the non-capacitative Ca channels, Orai3 and TRPC6, was found to be reduced in patients with stroke. Altogether, our data allow us to conclude that STC2 represents a promising marker of stroke/ictus in thrombotic patients.
STC2（鲽鱼降钙素2）调控人类血小板及其他细胞系中的钙（Ca）稳态。细胞内钙稳态的调节对血小板激活至关重要；因此，细胞内钙浓度的改变或其调节机制被认为是某些血栓性疾病的基础。我们之前的研究证明，STC2基因敲低会改变小鼠血小板的激活；此外，STC2表达的降低导致糖尿病患者的钙稳态增强，因此会导致作为2型糖尿病（DM2）标志的血栓前状态。在本研究中，我们探讨了鲽鱼降钙素（STCs）的表达与人类不同血栓形成事件之间的可能联系。通过蛋白质免疫印迹法（WB）测定STCs的表达；同时，通过完成对目标蛋白的先前免疫沉淀实验方案（IP）来进行蛋白质相互作用和磷酸化分析。因此，我们对中风/卒中患者的研究结果显示，他们血小板中STC2的表达明显降低，在最年轻的血栓形成患者中发现STC2含量更少。此外，阿司匹林（ASA）给药可逆转未发生额外血栓形成事件患者中STC2表达的降低，长达10年的随访纵向分析证明了这一点。此外，血栓形成患者中丝氨酸残基处STC2磷酸化的增加表明STC2的活性增强。最后，我们发现，静息状态下STIM1/Orai1相互作用增加，表明中风/卒中患者的钙库操纵性钙内流（SOCE）过度激活，此外，用siRNA STC2转染MEG - 01细胞以人工降低STC2表达，与用siRNA A转染的对照细胞相比，SOCE增加。相反，中风患者中发现非容量性钙通道Orai3和TRPC6的表达降低。总之，我们的数据使我们得出结论，STC2是血栓形成患者中风/卒中的一个有前景的标志物。
