Measuring Steroids in Teeth with LC-MS/MS

A recent study at the University of British Columbia (Vancouver, Canada) and published in PLoS One (1) introduced the first assay developed and validated to measure steroids in human primary teeth using liquid chromatography-tandem spectrometry (LC-MS/MS). The authors report that this assay is highly sensitive, specific, accurate, and precise, allowing for the simultaneous quantification of 17 steroids in primary teeth (16 of which have not been examined previously in primary teeth). In addition, the data culled from this assay demonstrates that multiple steroids can be quantified by LC-MS/MS in human primary teeth, and potentially provides a powerful new way to retrospectively assess early-life stress and developmental endocrine pathologies.

Steroid hormones are important modulators of a myriad of physiological processes, including metabolism, mood and cognition, and reproduction (2-5). Secreted by the adrenal glands and gonads, these hormones are regulated by the hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-gonadal (HPG) axes (5). The dysregulation of steroid hormone secretion by, for example, chronic stress or endocrine disrupting chemicals (EDCs), may lead to various diseases, such metabolic syndrome, mood disorders, and infertility (6,7).

Overall, steroid levels in primary teeth were found to be relatively low, and eight steroids were quantifiable. Levels of dehydroepiandrosterone, cortisol, and progesterone were the highest of the 17 steroids examined. The researchers then used this assay to perform steroid profiling in primary teeth from women and men. The same eight steroids were quantifiable, with no differences due to sex found. Levels of androgens (androstenedione and testosterone) were positively correlated, as were the levels of levels of glucocorticoids (cortisol, cortisone, corticosterone, 11-dehydrocorticosterone).

The authors believe that future investigations would be useful, admitting to the possibility that steroids in teeth exist as conjugated metabolites, as in urine. Therefore, conjugated steroids in primary teeth should be examined. Furthermore, they are of the opinion that the measurement of sex steroids in adult teeth, and possible sex differences uncovered, would be informative. They also believe that it would be of interest to measure glucocorticoid (GC) levels in primary teeth and associations with developmental stressors such as maternal illness and low socioeconomic status. Fourth, tooth GC levels can be correlated with growth marks in primary teeth, which have previously been used to track early-life stress (ELS). Additionally, teeth can be separated at these growth marks to allow for temporal resolution. For example, separating teeth at the neonatal line, the growth mark that denotes an individual’s birth, could allow the scientists to tease apart prenatal and postnatal GC levels. Such studies would shed light on the potential of using primary teeth GCs to assess ELS and other developmental conditions.

Closeup with perfect female teeth. © Catalin Pop- stock.adobe.com

References

1. Wu, R. S.; Hamden, J. E.; Salehzadeh, M.; Li, M.X.; Poudel, A.; Schmidt, K. L,; Kobor, M. S.; Soma, K. K. Steroid Profiling in Human Primary Teeth via Liquid Chromatography-Tandem Mass Spectrometry for Long-Term Retrospective Steroid Measurement. PLoS One 2024, 19 (8), e0309478. DOI: 10.1371/journal.pone.0309478

2. McEwen, B. S.; Bowles, N. P.; Gray, J. D.; Hill, M. N.; Hunter, R. G.; Karatsoreos, I. N. et al. Mechanisms of Stress in the Brain. Nat. Neurosci. 2015, 18 (10), 1353–1363. DOI: 10.1038/nn.4086

3. Baulieu, E. E. Neurosteroids: A New Function in the Brain. Biol Cell. 1991, 71 (1–2), 3–10. DOI: 10.1016/0248-4900(91)90045-O

4. Zitzmann M. Testosterone Mood, Behaviour and Quality of Life. Andrology 2020, 8 (6), 1598–1605. DOI: 10.1111/andr.12867

5. Cole, T. J.; Short, K. L.; Hooper, S. B. The Science of Steroids. Semin. Fetal. Neonatal. Med. 2019, 24 (3), 170–175. DOI: 10.1016/j.siny.2019.05.005

6. Honour, J. W. Diagnosis of Diseases of Steroid Hormone Production, Metabolism and Action. J. Clin. Res. Pediatr. Endocrinol. 2009, 1(5), 209–226. DOI: 10.4274/jcrpe.v1i5.209

7. Wang, M.; Backstrom, T.; Sundstrom, I.; Wahlstrom, G.; Olsson, T.; Zhu, D. et al. Neuroactive Steroids and Central Nervous System Disorders. Int. Rev. Neurobiol. 2001, 46, 421–459. DOI: 10.1016/S0074-7742(01)46071-5