細(xì)胞的力學(xué)性質(zhì)很大程度上由細(xì)胞骨架決定,，細(xì)胞骨架是由微管,、中間絲和肌動(dòng)蛋白絲這三種主要的蛋白絲構(gòu)成的自組織網(wǎng)狀結(jié)構(gòu),。作為最堅(jiān)硬的細(xì)胞骨架絲,，在活細(xì)胞內(nèi)微管承受壓力,，以平衡細(xì)胞骨架內(nèi)的拉力來(lái)維系細(xì)胞形狀,。
實(shí)驗(yàn)室中經(jīng)常發(fā)現(xiàn)在活細(xì)胞內(nèi),，受壓的微管皺曲為短波長(zhǎng)的形狀。與之相比較，孤立的體外微管則皺曲成單一的長(zhǎng)波長(zhǎng)弧形,。體外微管的關(guān)鍵皺曲力要比活細(xì)胞條件下低兩個(gè)數(shù)量級(jí),。為解釋這個(gè)差別，馬里蘭大學(xué)學(xué)者Teng Li構(gòu)建了一個(gè)活細(xì)胞的微管皺曲力學(xué)模型,。運(yùn)用該模型研究了周圍細(xì)絲網(wǎng)狀結(jié)構(gòu)和胞質(zhì)溶膠對(duì)微管皺曲的作用,。研究結(jié)果顯示，皺曲波長(zhǎng)由微管和周圍彈性細(xì)絲網(wǎng)狀結(jié)構(gòu)的共同作用決定,，皺曲的增長(zhǎng)率由粘性胞質(zhì)溶膠決定,。考慮皺曲的微管的非線性變形,，皺曲振幅可以通過(guò)動(dòng)力學(xué)約束方程決定,。
這個(gè)模型通過(guò)微管的皺曲波長(zhǎng)、增長(zhǎng)率和振幅定量地把微管彎曲強(qiáng)度,、周圍細(xì)絲網(wǎng)狀結(jié)構(gòu)的彈性和胞質(zhì)溶膠的粘性連接起來(lái),。模型所預(yù)測(cè)的短波長(zhǎng)皺曲行為與實(shí)驗(yàn)結(jié)果吻合較好，這一結(jié)果為設(shè)計(jì)統(tǒng)一標(biāo)準(zhǔn)的實(shí)驗(yàn)儀器來(lái)測(cè)量活細(xì)胞條件下亞細(xì)胞結(jié)構(gòu)的各種關(guān)鍵力學(xué)參數(shù)奠定了基礎(chǔ),。
相關(guān)論文發(fā)表在愛(ài)思唯爾期刊《生物力學(xué)雜志》（Journal of Biomechanics）上,。（科學(xué)新聞雜志 牛文鑫/編譯）
生物谷推薦原始出處：
A mechanics model of microtubule buckling in living cells
Teng Li, a,
aDepartment of Mechanical Engineering and Maryland NanoCenter, University of Maryland, 2181 Glenn L. Martin Hall, College Park, MD 20742, USA
Accepted 5 March 2008. Available online 22 April 2008.
Abstract
As the most rigid cytoskeletal filaments, microtubules bear compressive forces in living cells, balancing the tensile forces within the cytoskeleton to maintain the cell shape. It is often observed that, in living cells, microtubules under compression severely buckle into short wavelengths. By contrast, when compressed, isolated microtubules in vitro buckle into single long-wavelength arcs. The critical buckling force of the microtubules in vitro is two orders of magnitude lower than that of the microtubules in living cells. To explain this discrepancy, we describe a mechanics model of microtubule buckling in living cells. The model investigates the effect of the surrounding filament network and the cytosol on the microtubule buckling. The results show that, while the buckling wavelength is set by the interplay between the microtubules and the elastic surrounding filament network, the buckling growth rate is set by the viscous cytosol. By considering the nonlinear deformation of the buckled microtubule, the buckling amplitude can be determined at the kinetically constrained equilibrium. The model quantitatively correlates the microtubule bending rigidity, the surrounding filament network elasticity, and the cytosol viscosity with the buckling wavelength, the buckling growth rate, and the buckling amplitude of the microtubules. Such results shed light on designing a unified experimental protocol to measure various critical mechanical properties of subcellular structures in living cells.
Keywords: Microtubule; Buckling; Cytoskeleton; Mechanics modeling
