Karmakar Shilpita, Saha Sutapa, Banerjee Debasis, Chakrabarti Abhijit
Biophysics and Structural Genomics Division, Saha Institute of Nuclear Physics, Kolkata, India.
Eur J Haematol. 2015 Jan;94(1):43-50. doi: 10.1111/ejh.12398. Epub 2014 Jul 16.
Harris platelet syndrome (HPS), also known as asymptomatic constitutional macrothrombocytopenia (ACMT), is an autosomal dominant platelet disorder characterized by mild-to-severe thrombocytopenia and giant platelets with normal platelet aggregation and absence of bleeding symptoms. We have attempted a comparative proteomics study for profiling of platelet proteins in healthy vs. pathological states to discover characteristic protein expression changes in macrothrombocytes and decipher the factors responsible for the functionally active yet morphologically distinct platelets.
We have used 2-D gel-based protein separation techniques coupled with MALDI-ToF/ToF-based mass spectrometric identification and characterization of the proteins to investigate the differential proteome profiling of platelet proteins isolated from the peripheral blood samples of patients and normal volunteers.
Our study revealed altered levels of actin-binding proteins such as myosin light chain, coactosin-like protein, actin-related protein 2/3 complex, and transgelin2 that hint toward the cytoskeletal changes necessary to maintain the structural and functional integrity of macrothrombocytes. We have also observed over expressed levels of peroxiredoxin2 that signifies the prevailing oxidative stress in these cells. Additionally, altered levels of protein disulfide isomerase and transthyretin provide insights into the measures adapted by the macrothrombocytes to maintain their normal functional activity. This first proteomics study of platelets from ACMT may provide an understanding of the structural stability and normal functioning of these platelets in spite of their large size.
哈里斯血小板综合征（HPS），也称为无症状性体质性大血小板减少症（ACMT），是一种常染色体显性血小板疾病，其特征为轻度至重度血小板减少以及存在正常血小板聚集且无出血症状的巨大血小板。我们尝试进行一项比较蛋白质组学研究，以分析健康状态与病理状态下的血小板蛋白质，从而发现大血小板中特征性的蛋白质表达变化，并解读导致功能活跃但形态独特的血小板的相关因素。
我们使用基于二维凝胶的蛋白质分离技术，结合基于基质辅助激光解吸电离飞行时间串联质谱（MALDI-ToF/ToF）的蛋白质鉴定和表征方法，来研究从患者和正常志愿者外周血样本中分离出的血小板蛋白质的差异蛋白质组图谱。
我们的研究揭示了肌动蛋白结合蛋白水平的改变，如肌球蛋白轻链、类辅肌动蛋白、肌动蛋白相关蛋白2/3复合物和原肌球蛋白2，这暗示了维持大血小板结构和功能完整性所需的细胞骨架变化。我们还观察到过氧化物酶2表达水平升高，这表明这些细胞中存在普遍的氧化应激。此外，蛋白质二硫键异构酶和转甲状腺素蛋白水平的改变为大血小板维持其正常功能活性所采取的措施提供了见解。这项对ACMT患者血小板的首次蛋白质组学研究可能有助于理解这些血小板尽管体积较大但仍具有的结构稳定性和正常功能。
