FTIR study of Achilles tendinopathy: protein secondary structure changes in tendon post injury
Introduction: Tendinopathy, a disease involving tendon inflammation and damage, results in considerable productivity and economic losses for the patient and the society. Currently available diagnosis/ treatment monitoring modalities are less efficacious and highly subjective, underlying the need for better tools. Previously, we have shown that Fourier Transform Infrared (FTIR) spectroscopy has potential in tendinopathy diagnosis/ monitoring, when combined with multivariate statistical analysis. The current study explores the spectral range that gave the best results in statistical analysis, to discover protein secondary structures associated with tendon injury and recovery that can act as markers of disease. Methods: Animals (n=60) underwent a surgery in which Achilles tendon were injured by dropping a 20g weight. Rats were divided into three groups (n=20) – control (C), Achilles tendon injury (I) and Achilles tendon injury treated with amniotic membrane fragment treated (T). FTIR spectra were obtained from each group 3, 7, 14, and 28 days post injury/ treatment. Results: Triple helix, β-turn, and disordered structure levels differ between control, injured and treated tendons over the time period studied. Parallel β-sheets increase steadily over time in treated tendons compared to control and injured. Conclusion: Combined analysis of Triple helix, β- sheets, β-turn, and disordered structure levels may be useful for tendinopathy diagnosis and treatment monitoring. However, further studies in this area are required to confirm the findings.
Alfredson H, Cook J. A treatment algorithm for managing Achilles tendinopathy: new treatment options. Br J Sports Med. 2007; 41(4):211-6. http://dx.doi.org/10.1136/bjsm.2007.035543. PMid:17311806.
Barth A. Infrared spectroscopy of proteins. Biochim Biophys Acta. 2007; 1767(9):1073-101. http://dx.doi.org/10.1016/j.bbabio.2007.06.004. PMid:17692815.
Bhatnagar BS, Bogner RH, Pikal MJ. Protein stability during freezing: separation of stresses and mechanisms of protein stabilization. Pharm Dev Technol. 2007; 12(5):505-23. http://dx.doi.org/10.1080/10837450701481157. PMid:17963151.
Bhattacharjee TT, Nicodemo MC, Sant’Anna LB, Lo Schiavo Arisawa EA, Raniero L. Tendinopathy diagnosis and treatment monitoring using attenuated total reflectance-Fourier transform infrared spectroscopy. J Biophotonics. 2018; 11(4):e201700256. http://dx.doi.org/10.1002/jbio.201700256. PMid:29160619.
Chadefaux C, Le Hô A-S, Bellot-Gurlet L, Reiche I. Curve-fitting Micro-ATR-FTIR studies of the amide I and II bands of type I collagen in archaeological bone materials. e-Preservation Science. 2009; 6:129-37.
Docking SI, Ooi CC, Connell D. Tendinopathy: is imaging telling us the entire story? J Orthop Sports Phys Ther. 2015; 45(11):842-52. http://dx.doi.org/10.2519/jospt.2015.5880. PMid:26390270.
Holey L. Tendon and ligament healing. Physiother. 2000; 86(6):326. http://dx.doi.org/10.1016/S0031-9406(05)61010-3.
Hopkins C, Fu S-C, Chua E, Hu X, Rolf C, Mattila VM, Qin L, Yung PS, Chan KM. Critical review on the socio-economic impact of tendinopathy. Asia Pac J Sports Med Arthrosc Rehabil Technol. 2016; 4:9-20. PMid:29264258.
Kvist M. Achilles tendon injuries in athletes. Sports Med. 1994; 18(3):173-201. http://dx.doi.org/10.2165/00007256-199418030-00004. PMid:7809555.
Lohrer H, David S, Nauck T. Surgical treatment for Achilles tendinopathy: a systematic review. BMC Musculoskelet Disord. 2016; 17(1):207. http://dx.doi.org/10.1186/s12891-016-1061-4. PMid:27165287.
Neves MAI, Pinfildi CE, Wood VT, Gobbato RC, Silva FM, Parizotto NA, Hochman B, Ferreira LM. Different power settings of LLLT on the repair of the calcaneal tendon. Photomed Laser Surg. 2011; 29(10):663-8. http://dx.doi.org/10.1089/pho.2010.2919. PMid:21668375.
Pedowitz D, Kirwan G. Achilles tendon ruptures. Curr Rev Musculoskelet Med. 2013; 6(4):285-93. http://dx.doi.org/10.1007/s12178-013-9185-8. PMid:24151122.
Roy I, Gupta MN. Freeze-drying of proteins: some emerging concerns. Biotechnol Appl Biochem. 2004; 39(2):165-77. http://dx.doi.org/10.1042/BA20030133. PMid:15032737.
Scott A, Backman LJ, Speed C. Tendinopathy: update on pathophysiology. J Orthop Sports Phys Ther. 2015; 45(11):833-41. http://dx.doi.org/10.2519/jospt.2015.5884. PMid:26390273.
Silver I, Rossdale P. Biochemistry and pathology of tendon injury and healing. Equine Vet J Suppl. 1983; 1:5-22.
Weintraub W. Tendon and ligament healing: a new approach to sports and overuse injury. New Mexico: Paradigm Publications; 2003.
Xu Y, Murrell GA. The basic science of tendinopathy. Clin Orthop Relat Res. 2008; 466(7):1528-38. http://dx.doi.org/10.1007/s11999-008-0286-4. PMid:18478310.