Abstract:
Prematurity has physical consequences, such as lower birth weight, decreased muscle mass and increased risk of adult-onset metabolic disease. Insulin-like growth factor 1 (IGF-1) has therapeutic potential to improve the growth and quality of muscle and tendon in premature births, and thus attenuate some of these sequalae. We investigated the effect of IGF-1 on extensor carpi radialis muscle and biceps brachii tendon of preterm piglets. The preterm group consisted of 19-day-old preterm (10 days early) piglets, treated with either IGF-1 or vehicle. Term controls consisted of groups of 9-day-old piglets (D9) and 19-day-old piglets (D19). Muscle samples were analysed by immunofluorescence to determine the cross-sectional area (CSA) of muscle fibres, fibre type composition, satellite cell content and central nuclei-containing fibres in the muscle. Tendon samples were analysed for CSA, collagen content and maturation, and vascularization. Gene expression of the tendon was measured by RT-qPCR. Across all endpoints, we found no significant effect of IGF-1 treatment on preterm piglets. Preterm piglets had smaller muscle fibre CSA compared to D9 and D19 control group. Satellite cell content was similar across all groups. For tendon, we found an effect of age on tendon CSA, and mRNA levels of COL1A1, tenomodulin and scleraxis. Immunoreactivity for elastin and CD31, and several markers of tendon maturation, were increased in D9 compared to the preterm piglets. Collagen content was similar across groups. IGF-1 treatment of preterm-born piglets does not influence the growth and maturation of skeletal muscle and tendon.
摘要:
早产有身体后果,例如较低的出生体重,肌肉质量下降,成人发病代谢性疾病的风险增加。胰岛素样生长因子1(IGF-1)具有改善早产的肌肉和肌腱生长和质量的治疗潜力,从而削弱了这些后遗症中的一些。我们研究了IGF-1对早产仔猪的radi腕伸肌和肱二头肌肌腱的影响。早产组由19日龄早产(提前10天)仔猪组成,用IGF-1或媒介物治疗。足月对照包括9日龄仔猪(D9)和19日龄仔猪(D19)的组。通过免疫荧光分析肌肉样品以确定肌肉纤维的横截面积(CSA),纤维类型成分,卫星细胞含量和肌肉中含有中央细胞核的纤维。分析了肌腱样本的CSA,胶原蛋白含量和成熟度,和血管化。通过RT-qPCR测量肌腱的基因表达。在所有端点中,我们发现IGF-1治疗对早产仔猪没有显著影响.与D9和D19对照组相比,早产仔猪的肌纤维CSA较小。所有组的卫星细胞含量相似。对于肌腱,我们发现年龄对肌腱CSA有影响,和COL1A1,腱调节素和巩膜的mRNA水平。弹性蛋白和CD31的免疫反应性,以及肌腱成熟的几种标志物,与早产仔猪相比,D9增加。各组的胶原含量相似。IGF-1治疗早产仔猪不影响骨骼肌和肌腱的生长和成熟。