Chen Ming, Wu Cuiping, Cui Yaqi, Ke Bingbing, Mao Linfei, Wang Hongyang, Shen Jinhong, Yin Shankai, Hu Mu, Li Chunyan
Department of Otolaryngology-Head and Neck Surgery, Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China.
Chinese PLA Institute of Otolaryngology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing 100853, China.
ACS Chem Neurosci. 2025 Jul 16;16(14):2602-2616. doi: 10.1021/acschemneuro.5c00117. Epub 2025 Jul 7.
Hypobilirubinemia, characterized by low bilirubin levels, is increasingly recognized as a pathological condition linked to various neurodevelopmental and neurodegenerative diseases. However, the neuropathological mechanisms of hypobilirubinemia remain unclear. In this study, we aimed to elucidate the potential molecular mechanism of neuronal structural and functional damage through integrated phosphoproteomics and proteomics analysis. Proteomic analysis of brain tissues from Biliverdin reductase-A knockout () mice and wild-type (WT) mice identified 133 differentially expressed proteins. Proteins with decreased abundance were enriched in axonogenesis, while proteins showing increased abundance were primarily involved in the PI3K-Akt signaling pathway, including LAMA4 and ITGA1. Phosphoproteomic analysis revealed 390 proteins with decreased phosphorylation at 542 sites, while 82 proteins had increased phosphorylation at 96 sites. Proteins associated with phosphosites showing decreased phosphorylation were enriched in neurogenesis and the axon guidance pathway, while those associated with increased phosphorylation sites were linked to neuronal apoptosis. Western blotting validation confirmed the modulation of key proteins, such as DPYSL2, MAPK8, and PRKCD, within the protein-protein interaction network of differentially expressed phosphorylated proteins, which have previously been implicated in neuronal development and degeneration. Golgi staining further revealed reduced number of dendritic intersections, branch points, shortened neurite length, and decreased dendritic complexity in mice compared to WT mice. These results indicated that low bilirubin levels disrupt brain protein phosphorylation regulatory networks, which may drive neuroinflammation, promote neuronal apoptosis, and impair neuronal growth, potentially contributing to neurodevelopmental and neurodegenerative diseases.
低胆红素血症，其特征为胆红素水平低下，越来越被认为是一种与各种神经发育和神经退行性疾病相关的病理状态。然而，低胆红素血症的神经病理机制仍不清楚。在本研究中，我们旨在通过整合磷酸化蛋白质组学和蛋白质组学分析来阐明神经元结构和功能损伤的潜在分子机制。对胆红素还原酶-A基因敲除（）小鼠和野生型（WT）小鼠的脑组织进行蛋白质组学分析，鉴定出133种差异表达蛋白。丰度降低的蛋白富集于轴突发生过程，而丰度增加的蛋白主要参与PI3K-Akt信号通路，包括层粘连蛋白A4（LAMA4）和整合素α1（ITGA1）。磷酸化蛋白质组学分析显示，有390种蛋白在542个位点的磷酸化水平降低，而82种蛋白在96个位点的磷酸化水平升高。与磷酸化水平降低的磷酸化位点相关的蛋白富集于神经发生和轴突导向通路，而与磷酸化水平升高的位点相关的蛋白则与神经元凋亡有关。蛋白质印迹验证证实了差异表达的磷酸化蛋白的蛋白质-蛋白质相互作用网络内关键蛋白（如双皮质素样2（DPYSL2）、丝裂原活化蛋白激酶8（MAPK8）和蛋白激酶Cδ（PRKCD））的调节，这些蛋白先前已被认为与神经元发育和退化有关。高尔基染色进一步显示，与野生型小鼠相比，基因敲除小鼠的树突交叉点、分支点数量减少，神经突长度缩短，树突复杂性降低。这些结果表明，低胆红素水平破坏了脑蛋白磷酸化调节网络，这可能会引发神经炎症，促进神经元凋亡，并损害神经元生长，从而可能导致神经发育和神经退行性疾病。
