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等离子膜折叠使成长中的哺乳动物细胞的表面积与体积比保持不变

Weida Wu^1,2, Alice R Lam¹, Kayla Suarez¹

¹Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.

bioRxiv : the preprint server for biology

|July 15, 2024

概括

哺乳动物细胞在生长过程中保持着恒定的表面积与体积比,这与预期相反. 这可以通过增加膜折叠来实现,确保为必要的细胞功能提供足够的表面积.

科学领域:

细胞生物学细胞生物学
生物物理学的生物物理.
生物系统中的几何缩放.

背景情况:

细胞面临着几何限制,特别是表面积与体积 (SA/V) 的比率,影响营养吸收和细胞大小.
一般认为,SA/V比率随着细胞大小的增加而下降,类似于球体.
研究SA/V比在哺乳动物细胞中是复杂的,因为等离子体膜的结构复杂.

研究的目的:

在近球形哺乳动物细胞中研究细胞表面成分与细胞大小的缩放.
为了确定SA/V比率是否保持不变或随着哺乳动物细胞的生长而下降.
探索SA/V比率维护在不同细胞状态中的机制和影响.

主要方法:

单细胞测量细胞质量和血膜蛋白/脂质.
对细胞表面成分缩放的分析作为SA/V比率的代理.
电子显微镜可可视化不同大小的细胞中的等离子体膜结构.

主要成果:

细胞表面成分在增殖细胞系中与细胞大小成比例,表明几乎恒定的SA/V比率.
这种恒定的SA/V比在细胞周期阶段,静止细胞 (包括单细胞) 和多倍化过程中都保持不变.
在较大的细胞中观察到血折叠的增加,这有助于维持恒定的SA/V比率.

结论:

哺乳动物细胞积极保持几乎恒定的SA/V比率,挑战了传统的假设,即SA/V随大小而减少.
血折叠是使这种恒定的SA/V比率成为可能的关键机制,支持关键的细胞功能.
虽然整体SA/V是不变的,但特定的表面蛋白和胆固醇可能会呈现尺寸依赖的偏差.

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