Hing W A, Sherwin A F, Poole C A
Division of Anatomy with Radiology, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand.
Osteoarthritis Cartilage. 2002 Apr;10(4):297-307. doi: 10.1053/joca.2002.0517.
To examine whether differences in the pericellular microenvironment of different chondron preparations influence the chondrocyte volume regulatory response to experimental osmotic challenge.
Mechanically extracted chondrons (MC), enzymatically extracted chondrons (EC) and isolated chondrocytes (IC) were seeded into agarose and sampled at 1, 3 and 7 days. Samples mounted in a perfusion chamber were subjected to osmotic challenge. The cross-sectional areas of the chondrocyte and pericellular microenvironment were measured under isotonic, hypertonic and hypotonic conditions, and percentage change calculated. Separate samples were immunolabeled for type VI collagen and keratan sulfate.
Initially, the microenvironment of MC represented 60% of the chondron area and was occupied by type VI collagen and keratan sulfate. In EC, the microenvironment comprised 18% of the chondron area with narrow bands of type VI collagen and keratan sulfate. IC had no visible microenvironment, with small amounts of type VI collagen and keratan sulfate present. All preparations sequestered additional pericellular macromolecules during culture. Under isotonic conditions, the EC and IC chondrocytes were larger than those of MC. All chondrocytes shrank under hypertonic conditions and swelled under hypotonic conditions. MC were the least responsive, displaying the most efficient volume regulation. IC showed the largest response initially but this decreased with time. EC exhibited intermediate responses that decreased as the microenvironment increased in size.
The composition and structural integrity of the pericellular microenvironment do influence the cellular response to experimental osmotic challenge. This suggests that the microenvironment functions in situ to mediate the chondrocyte response to physicochemical changes associated with joint loading.
研究不同软骨粒制剂细胞周围微环境的差异是否会影响软骨细胞对实验性渗透压挑战的体积调节反应。
将机械提取的软骨粒（MC）、酶提取的软骨粒（EC）和分离的软骨细胞（IC）接种到琼脂糖中，并在第1、3和7天取样。将安装在灌注室中的样品进行渗透压挑战。在等渗、高渗和低渗条件下测量软骨细胞和细胞周围微环境的横截面积，并计算百分比变化。对单独的样品进行VI型胶原和硫酸角质素的免疫标记。
最初，MC的微环境占软骨粒面积的60%，由VI型胶原和硫酸角质素占据。在EC中，微环境占软骨粒面积的18%，有狭窄的VI型胶原和硫酸角质素带。IC没有可见的微环境，仅存在少量的VI型胶原和硫酸角质素。所有制剂在培养过程中都会隔离额外的细胞周围大分子。在等渗条件下，EC和IC软骨细胞比MC的大。所有软骨细胞在高渗条件下收缩，在低渗条件下肿胀。MC的反应最小，显示出最有效的体积调节。IC最初显示出最大的反应，但随着时间的推移而降低。EC表现出中等反应，随着微环境尺寸的增加而降低。
细胞周围微环境的组成和结构完整性确实会影响细胞对实验性渗透压挑战的反应。这表明微环境在原位发挥作用，介导软骨细胞对与关节负荷相关的物理化学变化的反应。
