Martens G A
B-Probe, Diabetes Research Center, Brussels Free University (VUB), Belgium ; Department of Clinical Chemistry & Radioimmunology, University Hospital Brussels, Laarbeeklaan 103, 1090 Brussels, Belgium.
J Diabetes Res. 2015;2015:549818. doi: 10.1155/2015/549818. Epub 2015 May 10.
The core proteomes of human and rat pancreatic beta cells were compared by label-free LC-MS/MS: this resulted in quantification of relative molar abundances of 707 proteins belonging to functional pathways of intermediary metabolism, protein synthesis, and cytoskeleton. Relative molar abundances were conserved both within and between pathways enabling the selection of a housekeeping network for geometric normalization and the analysis of potentially relevant differential expressions. Human beta cells differed from rat beta cells in their lower level of enzymes involved in glucose sensing (MDH1, PC, and ACLY) and upregulation of lysosomal enzymes. Human cells also expressed more heat shock proteins and radical scavenging systems: apart from SOD2, they expressed high levels of H2O2-scavenger peroxiredoxin 3 (PRDX3), confirmed by microarray, Western blotting, and microscopy. Besides conferring lower susceptibility to oxidative stress to human cells PRDX3 might also play a role in physiological redox regulation as, in rat, its expression was restricted to a beta cell subset with higher metabolic glucose responsiveness. In conclusion, although their core proteomic architecture is conserved, human and rat beta cells differ in their molar expression of key enzymes involved in glucose sensing and redox control.
通过无标记液相色谱-串联质谱法比较了人和大鼠胰腺β细胞的核心蛋白质组：这使得能够对属于中间代谢、蛋白质合成和细胞骨架功能途径的707种蛋白质的相对摩尔丰度进行定量。相对摩尔丰度在各途径内部和之间都是保守的，这使得能够选择一个管家网络进行几何归一化，并分析潜在相关的差异表达。人β细胞与大鼠β细胞的不同之处在于，参与葡萄糖感知的酶（MDH1、PC和ACLY）水平较低，而溶酶体酶上调。人细胞还表达了更多的热休克蛋白和自由基清除系统：除了SOD2，它们还高水平表达H2O2清除剂过氧化物酶3（PRDX3），这通过微阵列、蛋白质印迹和显微镜检查得到证实。PRDX3除了使人细胞对氧化应激的敏感性降低外，还可能在生理氧化还原调节中发挥作用，因为在大鼠中，其表达仅限于具有较高代谢葡萄糖反应性的β细胞亚群。总之，尽管人和大鼠β细胞的核心蛋白质组结构是保守的，但它们在参与葡萄糖感知和氧化还原控制的关键酶的摩尔表达上存在差异。
