相关实验视频
Updated: May 15, 2025

07:20
Exploring the Regulation of Lipid Droplet Catabolism through Lipophagy
Published on: January 31, 2025
377
斯芬哥辛激酶2的缺陷通过抑制mTORC2酸化和激活伴侣介导的自酶来损害VLDL分泌
Shuangshuang Zhang1, Gaoxiang Li1, Lianping He2
1School of Life Sciences, Anhui Medical University, Hefei, 230032, Anhui, China.
Cell death and differentiation
|April 8, 2025
概括
斯芬哥辛激酶2 (SphK2) 缺乏会通过加快SNARE蛋白降解,通过伴侣介导的自,损害极低密度脂蛋白 (VLDL) 的分泌. 激活mTORC2或补充S1P可以恢复VLDL分泌,提供潜在的MASLD治疗方法.
科学领域:
- 肝病学和脂质代谢 肝病学和脂质代谢
- 分子细胞生物学 分子细胞生物学
- 酶的功能和调节
背景情况:
- 肝脏非常低密度脂蛋白 (VLDL) 对于脂质代谢至关重要.
- 斯芬戈氨基酶 (SphKs),特别是SphK1和SphK2,是脂代谢中的关键酶.
- 已知SphK1在肝炎和药物代谢中的作用,但SphK2在脂质代谢中的作用不太清楚.
研究的目的:
- 调查斯芬哥辛激酶2 (SphK2) 在调节肝脂代谢中的作用.
- 具体来说,是为了确定SphK2对非常低密度脂蛋白 (VLDL) 分泌的影响.
- 阐明SphK2在脂质平衡中的功能背后的分子机制.
主要方法:
- 来自MASLD患者的肝脏组织的免疫组织化学染色.
- 对Sphk2淘汰赛 (Sphk2-/-) 小鼠进行分析,这些小鼠表现出脂质积累和改变的VLDL分泌.
- 蛋白质组分析以确定受SphK2缺乏影响的蛋白质相互作用.
- 研究蛋白质降解途径,包括伴侣介导的自 (CMA).
主要成果:
- 在MASLD中,在靠近肝脏脂质积累的地方观察到降低的SphK2蛋白水平.
- Sphk2-/-小鼠表现出自发的肝细胞脂质积累和受损的VLDL分泌.
- 缺少SphK2会破坏SNARE复杂相互作用,并通过CMA加速SEC22B,STX5A和GS28蛋白质的降解.
- 通过MYH1485或S1P补充激活mTORC2,抵消了SphK2缺乏效应,恢复了VLDL分泌.
结论:
- SphK2在调节肝脏VLDL分泌和脂质代谢方面发挥着至关重要的作用.
- 通过mTORC2酸化,SphK2调节伴侣介导自 (CMA),影响SNARE蛋白的稳定性.
- 这些发现揭示了VLDL分泌的新型调节机制,并表明了MASLD的潜在治疗点.
相关概念视频
PI3K/mTOR/AKT Signaling Pathway
3.3K
The mammalian target of rapamycin (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast, mTORC2 consists of a...
3.3K
Lysosomal Hydrolases
3.7K
Lysosomes are the site for the degradation of macromolecules and biological polymers released during membrane trafficking events such as secretory, endocytic, autophagic, and phagocytic pathways. The membrane-enclosed area of the lysosome, called the lumen, contains hydrolytic enzymes active in an acidic environment. These acid hydrolases are functional at a pH between 4.5 and 5 and are involved in cellular processes such as cell signaling, energy metabolism, restoration of the plasma membrane,...
3.7K
mTOR Signaling and Cancer Progression
3.7K
The mammalian target of rapamycin or mTOR protein was discovered in 1994 due to its direct interaction with rapamycin. The protein gets its name from a yeast homolog called TOR. The mTOR protein complex in mammalian cells plays a major role in balancing anabolic processes such as the synthesis of proteins, lipids, and nucleotides and catabolic processes, such as autophagy in response to environmental cues, such as availability of nutrients and growth factors.
The mTOR pathway or the...
The mTOR pathway or the...
3.7K
The JAK-STAT Signaling Pathway
8.5K
Several cytokine receptors have tightly bound Janus kinase or JAK proteins attached at their cytosolic tail. Small signaling molecules such as cytokines, growth hormones, or prolactins bind to the cytokine receptors and initiate their dimerization. The dimerization brings the cytosolic JAKs together that trans-phosphorylate and activates each other. The activated JAKs now phosphorylate cytosolic tails of the cytokine receptors, which serve as binding sites for adaptor proteins such as SH2...
8.5K
Receptor Downregulation in MVBs
2.0K
Multivesicular bodies (MVBs) are mature endosomes that sort ubiquitinated proteins and then fuse with lysosomes to degrade the sorted proteins. Epidermal growth factor (EGF) and its receptor (EGFR) form a complex that can be internalized through endocytosis, sorted into an MVB, and later degraded.
The EGFR can initiate signaling pathways that lead to cell proliferation, migration, and differentiation. Overexpression of EGFR stimulates cells to proliferate. Excessive EGFR...
The EGFR can initiate signaling pathways that lead to cell proliferation, migration, and differentiation. Overexpression of EGFR stimulates cells to proliferate. Excessive EGFR...
2.0K

