Wang Yiqun, Li La, Wang Hongde, Cheng Jin, Du Cancan, Xu Luzheng, Fan Yifei, Hu Xiaoqing, Yin Yu, Wang Ruimin, Ao Yingfang
Department of Sports Medicine, Peking University Third Hospital, Institute of Sports Medicine of Peking University, Beijing, China.
Beijing Key Laboratory of Sports Injuries, Beijing, China.
EJNMMI Res. 2024 Oct 2;14(1):88. doi: 10.1186/s13550-024-01147-w.
Skeletal muscles are vital for daily function, yet assessing their injuries remain challenging. We aimed to elucidate the effectiveness of Ga-FAPI-04 in evaluating skeletal muscle remodeling.
C2C12 cells were subjected to graded HO stimulation in vitro, revealing an initial rise and subsequent decline in fibroblast activation protein (FAP) expression as HO concentration increased. In vivo, a murine triceps surae injury model was created using various solutions to simulate normal repair, mild repair failure, and severe repair failure. Assessments were conducted on days 1, 3, 7, and 14 using PET, MRI, and ultrasound. With Ga-FAPI-04, the normal and mild repair failure groups showed significantly higher SUVmax and T/B ratios on day 1 compared to the severe repair failure group. These values gradually decreased in the normal repair group, becoming negligible after day 7. MRI results for the normal repair group showed low to moderate signal intensity by day 7. A clinical study retrospectively evaluated post-hip arthroplasty patient images at intervals of 1 month, 2-3 months, 5-6 months, and over 7 months. In these patients, F-FDG SUVmax and volume remained relatively stable over time, while Ga-FAPI-04 SUVmax initially increased, then decreased, with a consistent reduction in volume.
In skeletal muscle injuries, FAP demonstrates a distinctive mechanism of action, and Ga-FAPI-04, in comparison to other tests, more precisely captures alterations in lesion site uptake intensity and volume.
Trial registration: ChiCTR2000041204. Registered 22 December 2020, https://www.chictr.org.cn/showproj.html?proj=66211.
骨骼肌对日常功能至关重要，但评估其损伤仍具有挑战性。我们旨在阐明镓标记的成纤维细胞活化蛋白抑制剂04（Ga-FAPI-04）在评估骨骼肌重塑中的有效性。
在体外对C2C12细胞进行分级的异位骨化（HO）刺激，结果显示随着HO浓度增加，成纤维细胞活化蛋白（FAP）表达先升高后降低。在体内，使用不同溶液创建了小鼠比目鱼肌损伤模型，以模拟正常修复、轻度修复失败和重度修复失败。在第1、3、7和14天使用正电子发射断层扫描（PET）、磁共振成像（MRI）和超声进行评估。使用Ga-FAPI-04时，与重度修复失败组相比，正常和轻度修复失败组在第1天的最大标准摄取值（SUVmax）和靶本比（T/B）显著更高。这些值在正常修复组中逐渐降低，在第7天后变得微不足道。正常修复组的MRI结果显示到第7天时信号强度为低至中度。一项临床研究回顾性评估了髋关节置换术后患者在1个月、2至3个月、5至6个月和7个月以上的图像。在这些患者中，氟代脱氧葡萄糖（F-FDG）的SUVmax和体积随时间保持相对稳定，而Ga-FAPI-04的SUVmax最初升高，然后降低，体积持续减小。
在骨骼肌损伤中，FAP表现出独特的作用机制，与其他检测方法相比，Ga-FAPI-04能更精确地捕捉病变部位摄取强度和体积的变化。
试验注册：中国临床试验注册中心标识符：ChiCTR2000041204。于2020年12月22日注册，https://www.chictr.org.cn/showproj.html?proj=662
