Raman spectroscopy as a predictive tool for monitoring osteoporosis therapy in a rat model of postmenopausal osteoporosis
Pharmacological therapy of osteoporosis reduces bone loss and risk of fracture in patients. Modulation of bone mineral density cannot explain all effects. Other aspects of bone quality affecting fragility and ways to monitor them need to be better understood. Keratinous tissue acts as surrogate marker for bone protein deterioration caused by oestrogen deficiency in rats. Ovariectomised rats were treated with alendronate (ALN), parathyroid hormone (PTH) or estrogen (E2). MicroCT assessed macro structural changes. Raman spectroscopy assessed biochemical changes. Micro CT confirmed that all treatments prevented ovariectomy-induced macro structural bone loss in rats. PTH induced macro structural changes unrelated to ovariectomy. Raman analysis revealed ALN and PTH partially protect against molecular level changes to bone collagen (80% protection) and mineral (50% protection) phases. E2 failed to prevent biochemical change. The treatments induced alterations unassociated with the ovariectomy; increased beta sheet with E2, globular alpha helices with PTH and fibrous alpha helices with both ALN and PTH. ALN is closest to maintaining physiological status of the animals, while PTH (comparable protective effect) induces side effects. E2 is unable to prevent molecular level changes associated with ovariectomy. Raman spectroscopy can act as predictive tool for monitoring pharmacological therapy of osteoporosis in rodents. Keratinous tissue is a useful surrogate marker for the protein related impact of these therapies.The results demonstrate utility of surrogates where a clear systemic causation connects the surrogate to the target tissue. It demonstrates the need to assess broader biomolecular impact of interventions to examine side effects.
Osteoporotic treatments exhibit substantial differences in biochemical impact.
Alendronate preserved the bone tissue in the state closest to the sham group.
Parathyroid hormone prevents ovariectomy changes, induces different changes.
Estrogen preserves tissue macro structure, but unable to prevent biochemical changes.
Systemic conditions affect structural proteins in both bone and claw.
ovariectomised treated with alendronate
ovariectomised treated with estrogen
ovariectomised treated with parathyroid hormone
standard error of the mean
bone mineral density
Dual energy X-ray Absorptiometry
micro computed tomography
Principle Component Analysis
linear discriminant analysis
area under the curve for the receiver operator characteristics
region of interest
This work was supported by Crescent Diagnostics Ltd. and Intertrade Ireland (FUSION programme 2012).
Compliance with ethical standards
Conflict of interest
RB and MCC are former employees of Crescent Ops Ltd, a company which owns intellectual property on the relationship between Raman spectroscopy, nail structure and fracture risk. MT and RB are shareholders in Crescent Ops Ltd. MT, NC, OOD and RB have served as consultants for Crescent Ops Ltd. Crescent Diagnostics Ltd funded the work carried out by MCC, JRB, (OD), NMC, MT and SHR. AI and AS declare no conflict of interest.
- 1.NIH Consensus Development Panel on Osteoporosis Prevention, Diagnosis, and Therapy. Osteoporosis prevention, diagnosis, and therapy. JAMA 2001;285:785–95. https://doi.org/10.1001/jama.285.6.785
- 7.Beattie JR, Cummins NM, Caraher C, O’Driscoll OM, Bansal AT, Eastell R et al. Raman spectroscopic analysis of fingernail clippings can help differentiate between postmenopausal women who have and have not suffered a fracture. Clin Med Insights Arthritis Musculoskelet Disord. 2016;9:109–16. https://doi.org/10.4137/CMAMD.S38493 CrossRefGoogle Scholar
- 9.Beattie JR, Feskanich D, Caraher MC, Towler MR. A preliminary evaluation of the ability of keratotic tissue to act as a prognostic indicator of hip fracture risk. Clin Med Insights Arthritis Musculoskelet Disord. 2018;11:117954411775405 https://doi.org/10.1177/1179544117754050 CrossRefGoogle Scholar
- 11.Bruyere O, Roux C, Detilleux J, Slosman DO, Spector TD, Fardellone P et al. Relationship between bone mineral density changes and fracture risk reduction in patients treated with strontium ranelate. J Clin Endocrinol Metab. 2007;92:3076–81. https://doi.org/10.1210/jc.2006-2758 CrossRefGoogle Scholar
- 17.Cummings SR, Black DM, Thompson DE, Applegate WB, Barrett-Connor E, Musliner TA et al. Effect of alendronate on risk of fracture in women with low bone density but without vertebral fractures: results from the fracture intervention trial. JAMA. 1998;280:2077 https://doi.org/10.1001/jama.280.24.2077 CrossRefGoogle Scholar
- 18.Cauley JA, Seeley DG, Ensrud K, Ettinger B, Black D, Cummings SR. Estrogen replacement therapy and fractures in older women. Ann Intern Med. 1995;122:9 https://doi.org/10.7326/0003-4819-122-1-199501010-00002 CrossRefGoogle Scholar
- 23.A Sophocleous, AI Idris, Rodent models of osteoporosis, Bonekey Rep. 3 (2014). https://doi.org/10.1038/bonekey.2014.109
- 28.Mandair GS, Esmonde-White FWL, Akhter MP, Swift AM, Kreider J, Goldstein SA et al. Potential of Raman spectroscopy for evaluation of bone quality in osteoporosis patients: results of a prospective study, In: Kollias N, Choi B, Zeng H, Malek RS, Wong BJ, Ilgner JFR (eds). USA: International Society for Optics and Photonics; 2010: p. 754846. https://doi.org/10.1117/12.842515
- 30.Campbell GM, Sophocleous A, Quantitative analysis of bone and soft tissue by micro-computed tomography: applications to ex vivo and in vivo studies, Bonekey Rep. 3 (2014). https://doi.org/10.1038/bonekey.2014.59
- 32.Lindsay R, Gallagher JC, Kagan R, Pickar JH, Constantine G. Efficacy of tissue-selective estrogen complex of bazedoxifene/conjugated estrogens for osteoporosis prevention in at-risk postmenopausal women. Fertil Steril. 2009;92:1045–52. https://doi.org/10.1016/J.FERTNSTERT.2009.02.093 CrossRefGoogle Scholar
- 33.Hodsman AB, Hanley DA, Ettinger MP, Bolognese MA, Fox J, Metcalfe AJ et al. Efficacy and safety of human parathyroid Hormone-(1–84) in increasing bone mineral density in postmenopausal osteoporosis. J Clin Endocrinol Metab. 2003;88:5212–20. https://doi.org/10.1210/jc.2003-030768 CrossRefGoogle Scholar
- 34.Cosman F, Combination therapy for osteoporosis: a reappraisal, Bonekey Rep. 3 (2014). https://doi.org/10.1038/bonekey.2014.13
- 36.Saito M, Marumo K, Kida Y, Ushiku C, Kato S, Takao-Kawabata R et al. Changes in the contents of enzymatic immature, mature, and non-enzymatic senescent cross-links of collagen after once-weekly treatment with human parathyroid hormone (1–34) for 18 months contribute to improvement of bone strength in ovariectomized monkeys. Osteoporos Int. 2011;22:2373–83. https://doi.org/10.1007/s00198-010-1454-4 CrossRefGoogle Scholar
- 43.Ascenzi M-G, Liao VP, Lee BM, Billi F, Zhou H, Lindsay R et al. Parathyroid hormone treatment improves the cortical bone microstructure by improving the distribution of type I collagen in postmenopausal women with osteoporosis. J Bone Miner Res. 2012;27:702–12. https://doi.org/10.1002/jbmr.1497 CrossRefGoogle Scholar