弯月面,膝关节的坐垫,是将机械力传递到细胞外基质(ECM)和组织驻留细胞的承重组织。人组织驻留在半月板中的干/祖细胞(hMeSPCs)的机械反应对组织稳态和再生很重要,但尚未得到充分了解。这项研究报告说,接种在三维(3D)光交联明胶甲基丙烯酰(GelMA)水凝胶中的hMeSPCs上的〜1800负载/天的温和循环拉伸加载方案对于维持细胞稳态至关重要。实验上,“慢走”仿生循环负荷方案(10%拉伸应变,0.5Hz,1小时/天,长达15天)应用于具有磁力控制的加载致动器的封装在GelMA水凝胶中的hMeSPC。加载显著增加细胞分化和纤维软骨样ECM沉积而不影响细胞活力。转录组分析揭示了332个机械响应基因,集群成细胞衰老,机械灵敏度,和ECM动力学,与白细胞介素有关,整合素,和胶原/基质金属蛋白酶途径。细胞-GelMA构建体显示活性ECM重塑,使用绿色荧光标记(GFT)-GelMA水凝胶示踪。负载通过封装的hMeSPCs增强新生的细胞周基质的产生,这逐渐补偿了培养物中的水凝胶损失。这些发现证明了hMeSPCs强大的组织形成能力,以及机械因素在维持半月板稳态中的重要性。
Meniscus, the cushion in knee joint, is a load-bearing tissue that transfers mechanical forces to extracellular matrix (ECM) and tissue resident cells. The mechanoresponse of human tissue resident stem/progenitor cells in meniscus (hMeSPCs) is significant to tissue homeostasis and regeneration but is not well understood. This study reports that a mild cyclic tensile loading regimen of ∼1800 loads/day on hMeSPCs seeded in 3-dimensional (3D) photocrosslinked gelatin methacryloyl (GelMA) hydrogel is critical in maintaining cellular homeostasis. Experimentally, a \"slow walk\" biomimetic cyclic loading regimen (10% tensile strain, 0.5 Hz, 1 h/day, up to 15 days) is applied to hMeSPCs encapsulated in GelMA hydrogel with a magnetic force-controlled loading actuator. The loading significantly increases cell differentiation and fibrocartilage-like ECM deposition without affecting cell viability. Transcriptomic analysis reveals 332 mechanoresponsive genes, clustered into cell senescence, mechanical sensitivity, and ECM dynamics, associated with interleukins, integrins, and collagens/matrix metalloproteinase pathways. The cell-GelMA constructs show active ECM remodeling, traced using a green fluorescence tagged (GFT)-GelMA hydrogel. Loading enhances nascent pericellular matrix production by the encapsulated hMeSPCs, which gradually compensates for the hydrogel loss in the cultures. These findings demonstrate the strong tissue-forming ability of hMeSPCs, and the importance of mechanical factors in maintaining meniscus homeostasis.