Former Professor Kazutomo Inoue moved from Department of Surgery, Kyoto University Hospital with his research group to this Department in 1998, shortly after the foundation of the Institute. He and his research group have been intensely studying innovative therapy for diabetes mellitus, such as islet transplantation, bio-artificial pancreas, pancreas regeneration and so on from the late 1980s. Shoichiro Sumi, as an associate professor, took over Professor Inoue’s job after his retirement in 2003 and promote studies on macro-encapuslated islets and various cell sources toward ready-to-undergo treatment for diabetes mellitus.
Research and EducationThe mission of our department is to study regenerative medicine for endocrine and metabolic diseases in order to develop novel therapeutic approaches. Among such diseases, our major target is Diabetes Mellitus (DM).
DM is a leading cause of morbidity and mortality in industrialized countries and causes severe complications including nephropathy (renal failure) and retinopathy (blindness). Therefore, it is an urgent necessity to develop a universal therapeutic method to cure diabetes mellitus.
To this goal, we are currently working on the following subjects. 1. Bioartificial pancreas (BAP), especially polyvinyl alcohol-macro-encapsulated islets. 2. ES- and iPS-cell differentiation toward islet cells. 3. Robust islet cells by cell-fusion between islet cells and mesenchymal stem cells. 4. Toughened β-cell by knock-down of PHLDA3 (tumor-suppressor gene of islet cell tumor) and 5. Methods of cell sphere formation to obtain terminally differentiated islet cells
Bio-artifical pancreas (BAP) enables allo- or xeno-transplantation of islets or in vitro-processed islet-like cells without immune suppression. Fig.1 shows the mechanism of BAP (islets or islet-like cells surrounded by semi-permeable membrane or hydro-gel).
Fig. 2. We have uniquely developed PVA (poly-vinyl alcohol) macro-encapsulated islets by freezing-thawing method and showed its feasibility in rats and mice. PVA hydrosolution becomes gel through PVA micro-crystallization at low temperature. We combined this and the technique of islet cryopreservation. Now, we are studying this and developing new methods to process this toward future clinical application. Fig.2 shows PVA-macroencapsulated rat islets for intraperitoneal transplantation in mice (20X15X1 mm).
Recent Publications1. Qi Z, Yamamoto C, Imori N, Kinukawa A, Yang KC, Yanai G, Ikenoue E, Shen Y, Shirouzu Y, Hiura A, Inoue K, Sumi S. Immunoisolation effect of polyvinyl alcohol (PVA) macro-encapsulated islets in type 1 diabetes therapy. Cell Transplant. 21: 525-534, 2012.
2. Yang KC, Qi Z, Yanai G, Shirouzu Y, Lu DH, Lee HS, Sumi S. Cell coupling regulates Ins1, Pdx-1 and MafA to promote insulin secretion in mouse pancreatic beta cells. Process Biochemistry 46: 1853-1860, 2011.
3. Yang KC, Qi Z, Wu CC, Shirouza Y, Lin FH, Yanai G, Sumi S. The cytoprotection of chitosan based hydrogels in xenogeneic islet transplantation: An in vivo study in streptozotocin-induced diabetic mouse. Biochem Biophys Res Commun. 393(4): 818-823, 2010.
4. Qi Z, Shen Y, Yanai G, Yang K, Shirouzu Y, Hiura A, Sumi S. The in vivo performance of polyvinyl alcohol macro-encapsulated islets. Biomaterials 31(14): 4026-4031, 2010.
5. Sakata N, Gu Y, Qi M, Yamamoto C, Hiura A, Sumi S, Sunamura M, Matsuno S, Inoue K. Effect of rat-to-mouse bioartificial pancreas xenotransplantation on diabetic renal damage and survival. Pancreas. 32(3): 249-257, 2006.
LaboratoryAssociate professor: Shoichiro Sumi, MD., PhD
Lecturer: Yasumasa Shirouzu, MD, PhD
Office assistant employee: Kikuchi Yuko