Genetic Variation, Protein Composition and Potential Influences onTendon Properties in Humans

摘要

Sequence variations in genes that code for proteins involved in homeostatic processes within tendons mayinfluence tendon mechanical properties. Since variants of the four genes COL5A1, TNC, MMP3 and GDF5 have beenimplicated in the aetiopathogenesis of tendinopathies, which is ultimately characterised by abnormal structural andregulatory processes, sequence variations in these four genes may also influence how the tendon functions mechanically,even in the absence of tendinopathy. For example, two reports of association between variation in the COL5A1 gene andmeasures of flexibility complement reported associations between genotype and incidence of tendinopathy. Non-geneticfactors such as age, body mass and physical activity status influence risk of tendon injury and physical performancepotential independently from genomics, and also in gene-environment interactions. However, these non-genetic factorsare often not considered in genetic association studies, probably due to their retrospective nature. Further researchexamining COL5A1, TNC, MMP3 and GDF5, as well as other genes that may influence the maintenance of tendonhomeostasis such as COL1A1 which regulates the production of collagen type 1, the most abundant structural componentof tendon is encouraged. Establishing the genetic basis of tendon properties in asymptomatic populations may advanceunderstanding of some aspects relevant to physical performance and of the aetiology of tendinopathies. To improveunderstanding, accurate and reproducible assessments of tendon properties are required. However, no valid and reliableassessments of tendon properties, such as those involving in vivo ultrasound imaging techniques, have yet been applied togenetic association studies in humans.