在小鼠肝细胞中,Cosmc调节O-甘氨酸扩展
Rajindra P Aryal1, Maxence Noel1, Junwei Zeng1
1Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, CLS 11087 - 3 Blackfan Circle, Boston, MA 02115, United States.
Glycobiology
|August 31, 2024
概括
肝细胞通常产生复杂的O-甘氨酸,但在小鼠中删除Cosmc (C1Galt1c1) 会导致它们只产生简单的Tn抗原. 令人惊的是,这种O-糖化变化并没有影响胆固醇代谢或引起可观察到的表型.
科学领域:
- 生物化学 生物化学
- 葡萄糖生物学 葡萄糖生物学
- 分子生物学分子生物学
背景情况:
- 肝细胞通过O-甘氨酸合成众多的葡萄糖蛋白,这对细胞功能至关重要.
- 精确的角色和O-甘氨酸在肝细胞糖蛋白上的分布仍然不完全理解.
- 核心1O-甘氨酸 (T抗原/CD176) 在野生型 (WT) 鼠肝中是典型的,而Tn抗原 (CD175) 是一个更简单的前体.
研究的目的:
- 为了研究Cosmc (C1Galt1c1) 在肝脏O-糖化中的作用.
- 为了确定肝脏Cosmc删除对糖蛋白结构和血清成分的影响.
- 评估改变的O-糖化对胆固醇代谢和整体小鼠表型的影响.
主要方法:
- 产生肝细胞特异性Cosmc淘汰 (HEP-Cosmc-KO) 的小鼠.
- 从WT和HEP-Cosmc-KO小鼠的肝脏组织和血清中分析O-甘氨酸的概况.
- 对O-糖化蛋白质的西部斑分析,包括LDL受体 (LDLR) 和HMG-CoA减少酶.
主要成果:
- HEP-Cosmc-KO肝细胞缺乏扩展的O-甘氨酸,仅表达Tn抗原 (CD175) 而不是T抗原 (CD176).
- 在HEP-Cosmc-KO小鼠的血清中检测到含有Tn的糖蛋白,但在WT小鼠中没有检测到.
- LDL受体 (LDLR) 的分子量从WT中的~145kDa转移到HEP-Cosmc-KO小鼠中的~120kDa,而不会影响LDLR或HMG-CoA减小酶表达或胆固醇代谢.
结论:
- 肝脏Cosmc对于复杂O-甘氨酸的合成至关重要,特别是核心1结构.
- 由于Cosmc删除而导致的肝脏O-糖化变化不会显著影响胆固醇稳态,也不会导致明显的生理表型.
- 这项研究揭示了对肝细胞中O-糖化酶的途径和后果的新见解.
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