The Secretome of Mesenchymal Stem Cells Prevents Islet Beta Cell Apoptosis via an IL-10-Dependent Mechanism

Buthainah Al-Azzawi1, 3, Declan H. McGuigan2, Fiona N. Manderson Koivula2, Ajile Elttayef1, 3, Tina P. Dale1, Ying Yang1, Catriona Kelly2, Nicholas R. Forsyth1, *
1 School of Pharmacy and Bioengineering, Keele University, Keele, UK
2 Northern Ireland Centre for Stratified Medicine, School of Biomedical Sciences, Ulster University, Northern Ireland, UK
3 Biochemistry Department, College of Medicine, University of Al-Qadisiyah, Al Diwaniyah, Iraq

© 2020 Al-Azzawi et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the Hilton Research Centre, School of Pharmacy and Bioengineering, Keele University, Thornburrow Drive, Stoke-on-Trent, ST4 7QB, Keele, UK, Tel: +44 (0)1782 674388;



Type 1 Diabetes Mellitus (T1DM) is partly driven by autoimmune destruction of the pancreatic beta cell, facilitated by the release of inflammatory cytokines, including IFN-γ, TNF-α and IL-1β by cells of the innate immune system. Mesenchymal Stem Cells (MSCs) have been used to counteract autoimmunity in a range of therapeutic settings due to their secretion of trophic and immunomodulatory factors that ameliorate disease independently of the cells themselves.


The aim of this study was to assess the effect of the secretome of human bone-marrow derived MSCs on cytokine-driven beta cell apoptosis.


All experiments were conducted in two insulin-secreting islet cell lines (BRIN-BD11 and βTC1.6) with selected experiments confirmed in primary islets. MSC secretome was generated by conditioning serum-free media (MSC-CM) for 24 hours on sub-confluent MSC populations. The media was then removed and filtered in readiness for use.


Exposure to IFN-γ, TNF-α and IL-1β induced apoptosis in cell lines and primary islets. The addition of MSC-CM to cell lines and primary islets partially reversed cytokine-driven apoptosis. MSC-CM also restored glucose-stimulated insulin secretion in cytokine-treated cell lines, which was linked to improved cell viability following from cytokine challenge. Characterization of MSC-CM revealed significant concentrations of IL-4, IL-10, PIGF and VEGF. Of these, IL-10 alone prevented cytokine-driven apoptosis. Furthermore, the inhibition of IL-10 through the addition of a blocking antibody reversed the anti-apoptotic effects of MSC-CM.


Overall, the protective effects of MSC-CM on islet beta cell survival appear to be largely IL-10-dependent.

Keywords: Apoptosis, Beta-cell, Islet, IL-10, MSCs, Mesenchymal Stromal Cells, Mesenchymal Stem Cells, Secretome.