An engineered, quantifiable in vitro model for analysing the effect of proteostasis-targeting drugs on tissue physical properties
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Cellular function depends on the maintenance of protein homeostasis (proteostasis) by regulated protein degradation. Chronic dysregulation of proteostasis is associated with neurodegenerative and age-related diseases, and drugs targeting components of the protein degradation apparatus are increasingly used in cancer therapies. However, as chronic imbalances rather than loss of function mediate their pathogenesis, research models that allow for the study of the complex effects of drugs on tissue properties in proteostasis-associated diseases are almost completely lacking. Here, to determine the functional effects of impaired proteostatic fine-tuning, we applied a combination of materials science characterisation techniques to a cell-derived, in vitro model of bone-like tissue formation in which we pharmacologically perturbed protein degradation. We show that low-level inhibition of VCP/p97 and the proteasome, two major components of the degradation machinery, have remarkably different effects on the bone-like material that human bone-marrow derived mesenchymal stromal cells (hMSC) form in vitro. Specifically, whilst proteasome inhibition mildly enhances tissue formation, Raman spectroscopic, atomic force microscopy-based indentation, and electron microscopy imaging reveal that VCP/p97 inhibition induces the formation of bone-like tissue that is softer, contains less protein, appears to have more crystalline mineral, and may involve aberrant micro- and ultra-structural tissue organisation. These observations contrast with findings from conventional osteogenic assays that failed to identify any effect on mineralisation. Taken together, these data suggest that mild proteostatic impairment in hMSC alters the bone-like material they form in ways that could explain some pathologies associated with VCP/p97-related diseases. They also demonstrate the utility of quantitative materials science approaches for tackling long-standing questions in biology and medicine, and could form the basis for preclinical drug testing platforms to develop therapies for diseases stemming from perturbed proteostasis or for cancer therapies targeting protein degradation. Our findings may also have important implications for the field of tissue engineering, as the manufacture of cell-derived biomaterial scaffolds may need to consider proteostasis to effectively replicate native tissues.
Date Issued
2018-11
Date Acceptance
2018-08-20
Citation
Biomaterials, 2018, 183, pp.102-113
ISSN
0142-9612
Publisher
Elsevier
Start Page
102
End Page
113
Journal / Book Title
Biomaterials
Volume
183
Copyright Statement
© 2018 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license
(http://creativecommons.org/licenses/BY/4.0/).
(http://creativecommons.org/licenses/BY/4.0/).
Sponsor
CRUK
Identifier
https://www.sciencedirect.com/science/article/pii/S0142961218305969?via=ihub
Grant Number
C41494/A15448
Subjects
Atomic force microscopy
Cancer diagnosis and therapy
Proteasome
Proteostasis
Raman spectroscopy
VCP/p97
MD Multidisciplinary
Biomedical Engineering
Publication Status
Published
Date Publish Online
2018-08-21