Iguchi Kohta, Hatano Etsuro, Nirasawa Takashi, Iwasaki Noriyuki, Sato Motohiko, Yamamoto Gen, Yamanaka Kenya, Okamoto Tatsuya, Kasai Yosuke, Nakamura Naohiko, Fuji Hiroaki, Sakai Tomohito, Kakuda Nobuto, Seo Satoru, Taura Kojiro, Tashiro Kei, Uemoto Shinji, Ikegawa Masaya
Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Bruker Daltonics K. K., Yokohama, Japan.
PLoS One. 2017 Jan 6;12(1):e0167647. doi: 10.1371/journal.pone.0167647. eCollection 2017.
Liver regeneration after partial hepatectomy (PHx) is a time-dependent process, which is tightly regulated by multiple signaling cascades. Failure of this complex process leads to posthepatectomy liver failure (PHLF), which is associated with a high rate of mortality. Thus, it is extremely important to establish a useful biomarker of liver regeneration to help prevent PHLF. Here, we hypothesized that alterations in the plasma peptide profile may predict liver regeneration following PHx and hence we set up a diagnostic platform for monitoring posthepatectomy outcome. We chronologically analyzed plasma peptidomic profiles of 5 partially hepatectomized microminipigs using the ClinProtTM system, which consists of magnetic beads and MALDI-TOF/TOF MS. We identified endogenous circulating peptides specific to each phase of the postoperative course after PHx in pigs. Notably, peptide fragments of histones were detected immediately after PHx; the presence of these fragments may trigger liver regeneration in the very acute phase after PHx. An N-terminal fragment of hemoglobin subunit α (3627 m/z) was detected as an acute-phase-specific peptide. In the recovery phase, the short N-terminal fragments of albumin (3028, 3042 m/z) were decreased, whereas the long N-terminal fragment of the protein (8926 m/z) was increased. To further validate and extract phase-specific biomarkers using plasma peptidome after PHx, plasma specimens of 4 patients who underwent PHx were analyzed using the same method as we applied to pigs. It revealed that there was also phase-specificity in peptide profiles, one of which was represented by a fragment of complement C4b (2378 m/z). The strategy described herein is highly efficient for the identification and characterization of peptide biomarkers of liver regeneration in a swine PHx model. This strategy is feasible for application to human biomarker studies and will yield clues for understanding liver regeneration in human clinical trials.
部分肝切除术后（PHx）的肝脏再生是一个时间依赖性过程，受到多种信号级联的严格调控。这一复杂过程的失败会导致肝切除术后肝衰竭（PHLF），其死亡率很高。因此，建立一种有用的肝脏再生生物标志物以帮助预防PHLF极其重要。在此，我们假设血浆肽谱的改变可能预测PHx后的肝脏再生，因此我们建立了一个用于监测肝切除术后结果的诊断平台。我们使用由磁珠和MALDI-TOF/TOF MS组成的ClinProtTM系统，按时间顺序分析了5只接受部分肝切除的微型猪的血浆肽组学谱。我们鉴定出了猪PHx术后各阶段特有的内源性循环肽。值得注意的是，PHx后立即检测到组蛋白的肽片段；这些片段的存在可能在PHx后的极急性期触发肝脏再生。血红蛋白亚基α的N端片段（3627 m/z）被检测为急性期特异性肽。在恢复阶段，白蛋白的短N端片段（3028、3042 m/z）减少，而该蛋白的长N端片段（8926 m/z）增加。为了使用PHx后的血浆肽组进一步验证和提取阶段特异性生物标志物，我们采用与猪相同的方法分析了4例接受PHx患者的血浆样本。结果显示肽谱也存在阶段特异性，其中之一由补体C4b的一个片段（2378 m/z）代表。本文所述策略对于在猪PHx模型中鉴定和表征肝脏再生的肽生物标志物非常有效。该策略可应用于人类生物标志物研究，将为理解人类临床试验中的肝脏再生提供线索。
