Tian Dawei, Yue Danyang, Zhu Jingchen, Zhang Xiaoyu, Gong Mingliang, Long Mian, Zhang Yan, Pan Jun
Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, College of Bioengineering, Chongqing University, Chongqing 400044, China.
Center for Biomechanics and Bioengineering, Key Laboratory of Microgravity and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China.
ACS Nano. 2025 Jul 15;19(27):24850-24864. doi: 10.1021/acsnano.5c03069. Epub 2025 Jul 7.
The mechanism controlling the differentiation of mesenchymal stromal cells (MSCs) to the target cell is vital for their tissue repair. While integrins, physically connected focal adhesion proteins (FAs), cytoskeleton elements, and lamin A are involved, the quantitative roles of integrin tension and mechanoadaptation remain unknown. Here, we applied reversible shearing DNA-based tension probes (RSDTPs) to assess MSCs' integrin tension during spreading after biochemical induction to osteogenesis and chondrogenesis. The mechanical transmitters of paxillin, F-actin, and lamin A to transduce mechanical stress from integrin to the nucleus as well as differentiation of MSCs were assayed to reveal the mechanical adaptation of integrin tension. Integrin tensions of 44 and 5-18 pN were identified as the critical force for osteogenic and chondrogenic differentiations, respectively. To fit this tension difference, MSCs possessed FAs' orientation to align radially along the cell's normal axis in osteogenesis vs tangentially in chondrogenesis. Cytoskeleton F-actin was found to regulate the osteogenesis through altering the upstream integrin tension and FAs' orientation and the downstream lamin A expression but yield less influences on chondrogenesis. In turn, F-actin tended to be less modulated by lamin A and its accompanying changes in FAs and integrin tension than by biochemical induction. Lamin A favored the regulation of osteogenesis through altering the upstream integrin tension and orientations of FAs and F-actin but might play an inhibitory role in chondrogenic differentiation. This work contributes to the understanding of how integrins generate and transmit different magnitudes of forces to jointly regulate cell morphology and mechanical adaptability and to fit the differentiation fate of MSCs.
控制间充质基质细胞(MSC)向靶细胞分化的机制对其组织修复至关重要。虽然整合素、物理连接的粘着斑蛋白(FA)、细胞骨架元件和核纤层蛋白A都参与其中,但整合素张力和机械适应性的定量作用仍不清楚。在这里,我们应用基于可逆剪切DNA的张力探针(RSDTP)来评估生化诱导成骨和软骨生成后MSC铺展过程中的整合素张力。检测桩蛋白、F-肌动蛋白和核纤层蛋白A的机械传递体,以将机械应力从整合素转导至细胞核以及MSC的分化,以揭示整合素张力的机械适应性。分别确定44 pN和5-18 pN的整合素张力为成骨和软骨生成分化的临界力。为了适应这种张力差异,MSC在成骨过程中FA的方向沿细胞的法线轴径向排列,而在软骨生成过程中则沿切线方向排列。发现细胞骨架F-肌动蛋白通过改变上游整合素张力和FA的方向以及下游核纤层蛋白A的表达来调节成骨,但对软骨生成的影响较小。反过来,与生化诱导相比,F-肌动蛋白受核纤层蛋白A及其伴随的FA和整合素张力变化的调节较小。核纤层蛋白A通过改变上游整合素张力以及FA和F-肌动蛋白的方向来促进成骨调节,但可能在软骨生成分化中起抑制作用。这项工作有助于理解整合素如何产生和传递不同大小的力,以共同调节细胞形态和机械适应性,并适应MSC的分化命运。