Electrofusion of Mesenchymal Stem Cells and Islet Cells for Diabetes Therapy: A Rat Model
et al. (2013) Electrofusion of Mesenchymal Stem Cells and Islet Cells for Diabetes Therapy: A Rat
Model. PLoS ONE 8(5): e64499. doi:10.1371/journal.pone.0064499
Electrofusion of Mesenchymal Stem Cells and Islet Cells for Diabetes Therapy: A Rat Model
Goichi Yanai 0
Takashi Hayashi 0
Qi Zhi 0
Kai-Chiang Yang 0
Yasumasa Shirouzu 0
Takashi Shimabukuro 0
Akihito Hiura 0
Kazutomo Inoue 0
Shoichiro Sumi 0
Kathrin Maedler, University of Bremen, Germany
0 1 Department of Organ Reconstruction, Institute for Frontier Medical Sciences, Kyoto University , Kyoto , Japan , 2 Gakkentoshi Hospital , Kyoto , Japan , 3 Department of Histology and Embryology, School of Medicine, Nankai University , Tianjin , China , 4 School of Dentistry, College of Oral Medicine, Taipei Medical University , Taipei, Taiwan , 5 Takeda Bio Health Research Center, Kyoto, Japan, 6 Inoue Clinic Diabetes Center , Kyoto , Japan
Islet transplantation is a minimally invasive treatment for severe diabetes. However, it often requires multiple donors to accomplish insulin-independence and the long-term results are not yet satisfying. Therefore, novel ways to overcome these problems have been explored. Isolated islets are fragile and susceptible to pro-apoptotic factors and poorly proliferative. In contrast, mesenchymal stem cells (MSCs) are highly proliferative, anti-apoptotic and pluripotent to differentiate toward various cell types, promote angiogenesis and modulate inflammation, thereby studied as an enhancer of islet function and engraftment. Electrofusion is an efficient method of cell fusion and nuclear reprogramming occurs in hybrid cells between different cell types. Therefore, we hypothesized that electrofusion between MSC and islet cells may yield robust islet cells for diabetes therapy. We establish a method of electrofusion between dispersed islet cells and MSCs in rats. The fusion cells maintained glucose-responsive insulin release for 20 days in vitro. Renal subcapsular transplantation of fusion cells prepared from suboptimal islet mass (1,000 islets) that did not correct hyperglycemia even if co-transplanted with MSCs, caused slow but consistent lowering of blood glucose with significant weight gain within the observation period in streptozotocininduced diabetic rats. In the fusion cells between rat islet cells and mouse MSCs, RT-PCR showed new expression of both rat MSC-related genes and mouse b-cell-related genes, indicating bidirectional reprogramming of both b-cell and MSCs nuclei. Moreover, decreased caspase3 expression and new expression of Ki-67 in the islet cell nuclei suggested alleviated apoptosis and gain of proliferative capability, respectively. These results show that electrofusion between MSCs and islet cells yield special cells with b-cell function and robustness of MSCs and seems feasible for novel therapeutic strategy for diabetes mellitus.
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Funding: This study was supported in part by grants from the Japan Society for the Promotion of Science (Grants-in-Aid for Scientific Research (B), No. 18390364)
and Japan Science and Technology Agency (Core Research for Evolutional Science and Technology, No. 100083300006). The funders had no role in study design,
data collection and analysis, decision to publish, or preparation of the manuscript.
Competing Interests: The authors have declared that no competing interests exist.
Diabetes mellitus (DM) is a leading cause of morbidity and
mortality in industrialized countries, and the number of patients
affected is estimated to be 366 million in 2011 with an increase to
552 million by 2030 [1]. Among several types of DM, Type 1 DM
(T1DM) is characterized by the selective destruction of pancreatic
b-cells caused by an autoimmune attack or other unknown causes.
b-cell reconstruction is currently achieved only by either pancreas
or islet transplantation in clinical setting. Although clinical trials of
encapsulated islets that enable transplantation without immune
suppression are on-going [2], these transplantation therapies share
common problems of donor scarcity and adverse effects related to
immune suppression.
Islet transplantation is an effective therapy for T1DM, but
limited donor sources restrict it from becoming a major treatment
option [3,4]. In islet transplantation, a diabetic patient often
requires two or even three donor pancreata to accomplish
insulinindependence in current mainstream protocols, which makes the
problem of a donor shortage even more serious [5]. Even though
insulin-independence is achieved by islet transplantation, islet graft
function is rarely sustained with only 7.5% of these patients
remaining insulin-independent at 5 years post transplantation [3].
Loss of functional isolated islets occurs during the culture period
after isolation and purification [6]. It is established that apoptosis
triggered by withdrawal of growth factors [7], disruption of
extracellular matrix [6,8], and endotoxin contamination [9]
participates in islet loss under culture c (...truncated)