Karim A, Hall A C
Centre for Integrative Physiology, Deanery of Biomedical Sciences, Hugh Robson Building, George Square, Edinburgh EH8 9XD, Scotland,
Eur Cell Mater. 2016 Mar 29;31:205-20. doi: 10.22203/ecm.v031a14.
Partial-thickness cartilage injuries do not heal effectively, potentially leading to degeneration as occurs in post-traumatic osteoarthritis (PTOA). The role of chondrocytes could be crucial in determining the nature of the repair; however, their response to this injury is poorly understood. We have utilised an in vitro bovine osteochondral partial-thickness scalpel injury model and determined chondrocyte properties at and distant from the injury in the presence/absence of (a) serum-free DMEM (340 mOsm), (b) synovial fluid DMEM (SF-DMEM), (c) foetal calf serum DMEM (FCS-DMEM), (d) hyperosmolar serum-free DMEM (600 mOsm), or (e) hyperosmolar FCS-DMEM for up to two weeks. Chondrocytes were fluorescently-labelled with 5-chloromethylfluorescein-diacetate (CMFDA)/propidium iodide (PI) for live/dead cells and imaged using confocal microscopy. Quantitative data were obtained on chondrocyte properties (cell volume, clusters, morphology) at and distant from the injury. In serum-free DMEM, chondrocyte morphology at the injury remained unaffected throughout culture. However, with SF-DMEM or FCS-DMEM the chondrocytes displayed an increase in volume (p < 0.0001), cluster formation (FCS; p < 0.01) and abnormal morphology (p < 0.001) compared to serum-free DMEM. Cluster formation and shape changes during FCS-DMEM culture were more pronounced than with SF-DMEM. SF-DMEM or FCS-DMEM stimulated these changes to chondrocytes at the injury with only small effects on distant cells. Hyperosmolarity inhibited the morphological and volume changes to chondrocytes induced by FCS-DMEM (p < 0.001) and the injured cartilage had the appearance of that in serum-free DMEM. Raised osmolarity may therefore have benefit in preserving the morphological phenotype of chondrocytes at the site of injury, and thus promote more effective integrative repair in partial-thickness cartilage injury.
部分厚度软骨损伤无法有效愈合，可能会导致创伤后骨关节炎（PTOA）中出现的退变。软骨细胞在决定修复性质方面的作用可能至关重要；然而，人们对它们对这种损伤的反应了解甚少。我们利用体外牛骨软骨部分厚度手术刀损伤模型，在存在/不存在（a）无血清DMEM（340 mOsm）、（b）滑膜液DMEM（SF-DMEM）、（c）胎牛血清DMEM（FCS-DMEM）、（d）高渗无血清DMEM（600 mOsm）或（e）高渗FCS-DMEM的情况下，测定损伤处及远离损伤处的软骨细胞特性，最长达两周。用5-氯甲基荧光素二乙酸酯（CMFDA）/碘化丙啶（PI）对软骨细胞进行荧光标记以区分活细胞和死细胞，并使用共聚焦显微镜成像。获得了损伤处及远离损伤处软骨细胞特性（细胞体积、聚集、形态）的定量数据。在无血清DMEM中，损伤处软骨细胞的形态在整个培养过程中保持不变。然而，与无血清DMEM相比，在SF-DMEM或FCS-DMEM中，软骨细胞的体积增加（p < 0.0001）、形成聚集（FCS；p < 0.01）且形态异常（p < 0.001）。在FCS-DMEM培养过程中聚集形成和形状变化比在SF-DMEM中更明显。SF-DMEM或FCS-DMEM刺激损伤处软骨细胞发生这些变化，对远离损伤处的细胞影响较小。高渗抑制了FCS-DMEM诱导的软骨细胞形态和体积变化（p < 0.001），损伤软骨的外观与无血清DMEM中的相似。因此，提高渗透压可能有利于在损伤部位保留软骨细胞的形态表型，从而促进部分厚度软骨损伤的更有效整合修复。
