Loeser Richard F, Pacione Carol A, Chubinskaya Susan
Rheumatology, Rush Medical College of Rush-Presbyterian-St. Luke's Medical Center, 1725 West Harrison, Suite 1017, Chicago, IL 60612, USA.
Arthritis Rheum. 2003 Aug;48(8):2188-96. doi: 10.1002/art.11209.
Although growth factor therapy could be an attractive method for stimulating the repair of damaged cartilage matrix, there is evidence that with aging and/or with the development of osteoarthritis (OA), articular chondrocytes may become unresponsive to growth factor stimulation. The aim of the current study was to compare the ability of insulin-like growth factor+(IGF-1) and osteogenic protein+(OP-1), alone and in combination, to stimulate human normal and OA chondrocytes in culture.
Chondrocytes isolated by enzymatic digestion of cartilage obtained from subjects undergoing knee replacement for OA (n = 6) or from normal ankle joints of tissue donors (n = 7) were cultured in alginate beads in serum-free medium and treated for 21 days with 100 ng/ml IGF-1, 100 ng/ml OP-1, or both. Controls were treated with vehicle alone. The cultures were evaluated for cell survival, cell number by DNA analysis, matrix production by particle exclusion assay, and level of accumulated proteoglycan by dimethylmethylene blue assay.
After 21 days in serum-free alginate culture, survival of cells from OA cartilage was 65 +/- 2% (mean +/- SEM), while survival of cells from normal cartilage was significantly greater (82 +/- 3%). Treatment with either IGF-1 or OP-1 alone minimally improved survival, while the combination IGF +OP significantly improved survival, to 87 +/- 2% for OA cells and 95+/-1% for normal cells. Cell proliferation was noted only in the IGF+OP group; this was significant for both normal and OA cells ( approximately 2-fold increase in DNA levels). Matrix production, assessed by particle exclusion and by proteoglycan accumulation, was greatest in the cells treated with IGF + OP in both normal and OA cultures. When proteoglycan levels were corrected for cell numbers (mg proteoglycan/ng DNA), a significant increase over control was noted with OP-1 alone and IGF IGF-1 alone, in both normal and OA cultures, with the greatest levels in the combination group (3-fold increase over control).
OP-1 was more potent than IGF-1 in stimulating proteoglycan production in both normal and OA cells. However, the best results were obtained with the combination, suggesting that combined therapy with IGF-1 and OP-1 may be an effective strategy for treating OA cartilage damage.
尽管生长因子疗法可能是刺激受损软骨基质修复的一种有吸引力的方法，但有证据表明，随着衰老和/或骨关节炎（OA）的发展，关节软骨细胞可能对生长因子刺激无反应。本研究的目的是比较胰岛素样生长因子+（IGF-1）和成骨蛋白+（OP-1）单独及联合使用时，刺激培养的人正常软骨细胞和OA软骨细胞的能力。
通过酶消化从接受OA膝关节置换术的受试者（n = 6）或组织供体的正常踝关节（n = 7）获得的软骨分离软骨细胞，将其培养在无血清培养基中的藻酸盐珠中，并用100 ng/ml IGF-1、100 ng/ml OP-1或两者处理21天。对照组仅用赋形剂处理。通过DNA分析评估细胞存活率、细胞数量，通过颗粒排除试验评估基质产生，并通过二甲基亚甲基蓝试验评估积累的蛋白聚糖水平。
在无血清藻酸盐培养21天后，OA软骨细胞的存活率为65±2%（平均值±标准误），而正常软骨细胞的存活率显著更高（82±3%）。单独用IGF-1或OP-1处理对存活率的改善最小，而IGF+OP联合处理显著提高了存活率，OA细胞的存活率提高到87±2%，正常细胞的存活率提高到95±1%。仅在IGF+OP组中观察到细胞增殖；这对正常细胞和OA细胞均有显著意义（DNA水平增加约2倍）。通过颗粒排除和蛋白聚糖积累评估的基质产生，在正常和OA培养物中，用IGF+OP处理的细胞中最大。当校正细胞数量后的蛋白聚糖水平（mg蛋白聚糖/ng DNA）时，在正常和OA培养物中，单独使用OP-1和单独使用IGF-1均比对照组有显著增加，联合组水平最高（比对照组增加3倍）。
在刺激正常细胞和OA细胞中的蛋白聚糖产生方面，OP-1比IGF-1更有效。然而，联合使用获得了最佳结果，表明IGF-1和OP-1联合治疗可能是治疗OA软骨损伤的有效策略。
