Basic Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Diabetes. Nov 15, 2016; 7(19): 523-533
Published online Nov 15, 2016. doi: 10.4239/wjd.v7.i19.523
Implanting 1.1B4 human β-cell pseudoislets improves glycaemic control in diabetic severe combined immune deficient mice
Alastair D Green, Srividya Vasu, Neville H McClenaghan, Peter R Flatt
Alastair D Green, Neville H McClenaghan, Peter R Flatt, SAAD Centre for Pharmacy and Diabetes, University of Ulster, Coleraine, Northern Ireland BT52 1SA, United Kingdom
Srividya Vasu, Cell Growth and Metabolism Section, National Institute for Diabetes and Digestive and Kidney diseases, National Institutes of Health, Bethesda, MD 20892, United States
Author contributions: Flatt PR designed the study; Green AD and Vasu S conducted the experimental work and data analysis; Green AD, Vasu S, McClenaghan NH and Flatt PR wrote the manuscript; all authors approved the final version submitted for publication.
Supported by University of Ulster Research Strategic funding; and the award of a Northern Ireland Department of Employment and Learning Research Studentship to Alastair D Green.
Institutional review board statement: All the experiments were approved by Animal Welfare and Ethical Review Body at Ulster University.
Institutional animal care and use committee statement: All animal procedures were performed in adherence to the United Kingdom home office regulations (United Kingdom Animal Scientific Procedures Act 1986) and “Principles of laboratory animal care” (NIH Publication No. 86-23, revised 1985). The experiments were approved by the Northern Ireland Department of Health, Social Services and Public Safety and performed under the project license 2691 (Hormonal and Metabolic Studies).
Conflict-of-interest statement: The authors declare no conflicts of interest.
Data sharing statement: All data are included within the manuscript.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Srividya Vasu, PhD, Visiting Fellow, Cell Growth and Metabolism Section, National Institute for Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Old Georgetown Road and Center Drive, Bethesda, MD 20892, United States. s.vasu@outlook.com
Telephone: +1-301-4517001
Received: April 10, 2016
Peer-review started: April 12, 2016
First decision: May 19, 2016
Revised: August 20, 2016
Accepted: August 30, 2016
Article in press: August 31, 2016
Published online: November 15, 2016
Processing time: 214 Days and 7.2 Hours
Abstract
AIM

To investigate the potential of implanting pseudoislets formed from human insulin-releasing β-cell lines as an alternative to islet transplantation.

METHODS

In this study, the anti-diabetic potential of novel human insulin releasing 1.1B4 β-cells was evaluated by implanting the cells, either as free cell suspensions, or as three-dimensional pseudoislets, into the subscapular region of severe combined immune deficient mice rendered diabetic by single high-dose administration of streptozotocin. Metabolic parameters including food and fluid intake, bodyweight and blood glucose were monitored throughout the study. At the end of the study animals were given an intraperitoneal glucose tolerance test. Animals were then culled and blood and tissues were collected for analysis. Insulin and glucagon contents of plasma and tissues were measured by insulin radioimmunoassay and chemiluminescent enzyme-linked immunosorbance assay respectively. Histological analyses of pancreatic islets were carried out by quantitative fluorescence immunohistochemistry staining.

RESULTS

Both pseudoislet and cell suspension implants yielded well vascularised β-cell masses of similar insulin content. This was associated with progressive amelioration of hyperphagia (P < 0.05), polydipsia (P < 0.05), body weight loss (P < 0.05), hypoinsulinaemia (P < 0.05), hyperglycaemia (P < 0.05 - P < 0.001) and glucose tolerance (P < 0.01). Islet morphology was also significantly improved in both groups of transplanted mice, with increased β-cell (P < 0.05 - P < 0.001) and decreased alpha cell (P < 0.05 - P < 0.001) areas. Whereas mice receiving 1.1B4 cell suspensions eventually exhibited hypoglycaemic complications, pseudoislet recipients displayed a more gradual amelioration of diabetes, and achieved stable blood glucose control similar to non-diabetic mice at the end of the study.

CONCLUSION

Although further work is needed to address safety issues, these results provide proof of concept for possible therapeutic applicability of human β-cell line pseudoislets in diabetes.

Keywords: Human β-cell line; 1.1B4; Cell therapy; Insulin; Pseudoislets

Core tip: Human insulin-releasing 1.1B4 β-cell suspensions and psuedoislets were implanted in streptozotocin-diabetic severe combined immune deficient mice to assess their antidiabetic potential. Both cell configurations yielded vascularised, insulin positive β-cell masses. These were associated with beneficial effects on hyperphagia, polydipsia, body weight, hypoinsulinaemia, hyperglycaemia and glucose tolerance. Both treatments were also associated with significant improvements in islet morphology and increased β:α-cell ratio. Pseudoislet recipients displayed gradual glucose normalization, while cell suspension recipients ultimately presented with hypoglycaemic complications. These results provide proof of concept for possible clinical artificial human β-cell psuedoislets, although further work is needed to address the tumourigenicity of clonal cell-lines.