Comparison of breast skin resistance against protease digestion between young and elderly individual based on attenuation-of-sound values
Main Article Content
Abstract
The skin is a gateway through which bacteria can establish infection. Evidence has shown that the components of the skin change with age, with elderly individuals exhibiting fewer epidermal rete ridges, dermal collagen, and elastic fibers. In the present study, paraffin sections of breast skin were digested with proteolytic enzymes of bacterial origin, after which skin fragility was assessed by observing attenuation-of-sound (AOS) images over time. Accordingly, studies have shown that AOS values are correlated with tissue viscosity and can serve as a numerical indicator of protein density. Breast skin sections were digested using two types of collagenases and actinase E, a broader peptidase. Notably, our results showed that skin sections from young and elderly patients showed resistance to digestion with the two types of collagenases. However, the epidermis and dermis were successfully digested using actinase over time. All layers of the epidermis, except for the keratin layer, were digested, whereas collagen and elastic fibers in the dermis were broken down, along with a decrease in AOS levels. Although actinase affected both young and aged skin, elderly skin showed much lower AOS values given its naturally reduced thickness and density due to aging. This finding suggests that older patients experience greater damage from proteolytic enzymes. AOS is an excellent approach to visualizing the process of protease digestion over time and statistically comparing proteolytic damage.
Article Details
The Medical Research Archives grants authors the right to publish and reproduce the unrevised contribution in whole or in part at any time and in any form for any scholarly non-commercial purpose with the condition that all publications of the contribution include a full citation to the journal as published by the Medical Research Archives.
References
2. Khavkin J, Ellis DAF. Aging Skin: Histology, Physiology, and Pathology. Facial Plast Surg Clin North Am. 2011;19(2):229-234. doi:10.1016/j.fsc.2011.04.003
3. He T, Fisher GJ, Kim AJ, Quan T. Age-related changes in dermal collagen physical properties in human skin. PLoS One. 2023;18(12 December). doi:10.1371/journal.pone.0292791
4. Kerns M, Chien A, Kang S. Skin aging. In: Kang S, Amagai M, Bruckner A, et al., eds. Fitzpatrick’s Dermatology. Vol 1. 9th ed. Mc Graw Hill; 2019:1779-1791.
5. Lertzman BH, Gaspari AA. Drug Treatment of Skin and Soft Tissue Infections in Elderly Long-Term Care Residents. Vol 9.; 1996.
6. Stevens DL, Bisno AL, Chambers HF, et al. Practice guidelines for the diagnosis and management of skin and soft tissue infections: 2014 update by the infectious diseases society of America. Clinical Infectious Diseases. 2014;59(2). doi:10.1093/cid/ciu296
7. Saijo Y. Recent Applications of Acoustic Microscopy for Quantitative Measurement of Acoustic Properties of Soft Tissues. In: Mamou J, Oelze M, eds. Quantitative Ultrasound in Soft Tissues. Springer; 2013:291–313. doi:10.1007/978-94-007-6952-6_12
8. Miura K, Iwashita T. Observations of amyloid breakdown by proteases over time using scanning acoustic microscopy. Sci Rep. 2023;13(1):20642. doi:10.1038/s41598-023-48033-4
9. Miura K, Yamamoto S. Histological imaging from speed-of-sound through tissues by scanning acoustic microscopy (SAM). Protoc Exch. Published online 2013. doi:10.1038/protex.2013.040
10. Tamura K, Ito K, Yoshida S, Mamou J, Miura K, Yamamoto S. Alteration of speed-of-sound by fixatives and tissue processing methods in scanning acoustic microscopy. Front Phys. 2023;11. doi:10.3389/fphy.2023.1060296
11. Hozumi N, Yamashita R, Lee CK, et al. Time-frequency analysis for pulse driven ultrasonic microscopy for biological tissue characterization. In: Ultrasonics. Vol 42.;2004:717-722. doi:10.1016/j.ultras.2003.11.005
12. Sachs D, Fisher G, Voorhees J. Skin aging. In: Griffiths C, Barker J, Bleiker T, Chalmers R, Creamer D, eds. Rook’s Textbook of Dermatology. Vol 4. 9th ed. Wiley Blackwell; 2016:155.1-155.9.
13. Quan T, Fisher GJ. Role of age-associated alterations of the dermal extracellular matrix microenvironment in human skin aging: A mini-review. Gerontology. 2015;61(5):427-434. doi:10.1159/000371708
14. Miura K, Yamashita K. Mechanical weakness of thoracic aorta related to aging or dissection predicted by speed of sound with collagenase. Ultrasound Med Biol. 2019;45(12):3102-3115. doi:10.1016/j.ultrasmedbio.2019.08.012
15. Wang B, Yang W, McKittrick J, Meyers MA. Keratin: Structure, mechanical properties, occurrence in biological organisms, and efforts at bioinspiration. Prog Mater Sci. 2016;76:229-318. doi:10.1016/j.pmatsci.2015.06.001
16. Miura K, Yamashita K. Evaluation of aging, diabetes mellitus, and skin wounds by scanning acoustic microscopy with protease digestion. Pathobiology of Aging & Age-related Diseases. Published online 2018. doi:10.1080/20010001.2018.1516072
17. Bond JS. Proteases: History, discovery, and roles in health and disease. Journal of Biological Chemistry. 2019;294(5):1643-1651. doi:10.1074/jbc.TM118.004156
18. Mainz ER, Dobes NC, Allbritton NL. Pronase E-Based Generation of Fluorescent Peptide Fragments: Tracking Intracellular Peptide Fate in Single Cells. Anal Chem. 2015;87(15):7987-7995. doi:10.1021/acs.analchem.5b01929