1
|
Zacharovová K, Berková Z, Girman P, Saudek F. Adipose tissue-derived mesenchymal stem cells promote the vascularization of pancreatic islets transplanted into decellularized pancreatic skeletons. Transpl Immunol 2024; 86:102106. [PMID: 39128811 DOI: 10.1016/j.trim.2024.102106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 08/08/2024] [Accepted: 08/08/2024] [Indexed: 08/13/2024]
Abstract
We have recently developed a model of pancreatic islet transplantation into a decellularized pancreatic tail in rats. As the pancreatic skeletons completely lack endothelial cells, we investigated the effect of co-transplantation of mesenchymal stem cells and endothelial cells to promote revascularization. Decellularized matrix of the pancreatic tail was prepared by perfusion with Triton X-100, sodium dodecyl sulfate and DNase solution. Isolated pancreatic islets were infused into the skeletons via the splenic vein either alone, together with adipose tissue-derived mesenchymal stem cells (adMSCs), or with a combination of adMSCs and rat endothelial cells (rat ECs). Repopulated skeletons were transplanted into the subcutaneous tissue and explanted 9 days later for histological examination. Possible immunomodulatory effects of rat adMSCs on the survival of highly immunogenic green protein-expressing human ECs were also tested after their transplantation beneath the renal capsule. The immunomodulatory effects of adMSCs were also tested in vitro using the Invitrogen Click-iT EdU system. In the presence of adMSCs, the proliferation of splenocytes as a response to phytohaemagglutinin A was reduced by 47% (the stimulation index decreased from 1.7 to 0.9, P = 0.008) and the reaction to human ECs was reduced by 58% (the stimulation index decreased from 1.6 to 0.7, P = 0.03). Histological examination of the explanted skeletons seeded only with the islets showed their partial disintegration and only a rare presence of CD31-positive cells. However, skeletons seeded with a combination of islets and adMSCs showed preserved islet morphology and rich vascularity. In contrast, the addition of syngeneic rat ECs resulted in islet-cell necrosis with only few endothelial cells present. Live green fluorescence-positive endothelial cells transplanted either alone or with adMSCs were not detected beneath the renal capsule. Though the adMSCs significantly reduced in vitro proliferation stimulated by either phytohaemagglutinin A or by xenogeneic human ECs, in vivo co-transplanted adMSCs did not suppress the post-transplant immune response to xenogeneic ECs. Even in the syngeneic model, ECs co-transplantation did not lead to sufficient vascularization in the transplant area. In contrast, islet co-transplantation together with adMSCs successfully promoted the revascularization of extracellular matrix in the subcutaneous tissue.
Collapse
Affiliation(s)
- Klára Zacharovová
- Laboratory of Pancreatic Islets, Experimental Medicine Center, Institute for Clinical and Experimental Medicine, Videnska 1958/9, 14021 Prague, Czech Republic.
| | - Zuzana Berková
- Laboratory of Pancreatic Islets, Experimental Medicine Center, Institute for Clinical and Experimental Medicine, Videnska 1958/9, 14021 Prague, Czech Republic.
| | - Peter Girman
- Laboratory of Pancreatic Islets, Experimental Medicine Center, Institute for Clinical and Experimental Medicine, Videnska 1958/9, 14021 Prague, Czech Republic; Diabetes Center, Institute for Clinical and Experimental Medicine, Videnska 1958/9, 14021 Prague, Czech Republic.
| | - František Saudek
- Laboratory of Pancreatic Islets, Experimental Medicine Center, Institute for Clinical and Experimental Medicine, Videnska 1958/9, 14021 Prague, Czech Republic; Diabetes Center, Institute for Clinical and Experimental Medicine, Videnska 1958/9, 14021 Prague, Czech Republic.
| |
Collapse
|
2
|
Directed self-assembly of a xenogeneic vascularized endocrine pancreas for type 1 diabetes. Nat Commun 2023; 14:878. [PMID: 36797282 PMCID: PMC9935529 DOI: 10.1038/s41467-023-36582-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 02/06/2023] [Indexed: 02/18/2023] Open
Abstract
Intrahepatic islet transplantation is the standard cell therapy for β cell replacement. However, the shortage of organ donors and an unsatisfactory engraftment limit its application to a selected patients with type 1 diabetes. There is an urgent need to identify alternative strategies based on an unlimited source of insulin producing cells and innovative scaffolds to foster cell interaction and integration to orchestrate physiological endocrine function. We previously proposed the use of decellularized lung as a scaffold for β cell replacement with the final goal of engineering a vascularized endocrine organ. Here, we prototyped this technology with the integration of neonatal porcine islet and healthy subject-derived blood outgrowth endothelial cells to engineer a xenogeneic vascularized endocrine pancreas. We validated ex vivo cell integration and function, its engraftment and performance in a preclinical model of diabetes. Results showed that this technology not only is able to foster neonatal pig islet maturation in vitro, but also to perform in vivo immediately upon transplantation and for over 18 weeks, compared to normal performance within 8 weeks in various state of the art preclinical models. Given the recent progress in donor pig genetic engineering, this technology may enable the assembly of immune-protected functional endocrine organs.
Collapse
|
3
|
Han Z, He X, Feng Y, Jiang W, Zhou N, Huang X. Hsp20 Promotes Endothelial Progenitor Cell Angiogenesis via Activation of PI3K/Akt Signaling Pathway under Hypoxia. Tissue Eng Regen Med 2022; 19:1251-1266. [PMID: 36042130 PMCID: PMC9679071 DOI: 10.1007/s13770-022-00481-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 07/09/2022] [Accepted: 07/13/2022] [Indexed: 10/14/2022] Open
Abstract
BACKGROUND Mandibular distraction osteogenesis (MDO) is a kind of endogenous tissue engineering technology that lengthens the jaw and opens airway so that a patient can breathe safely and comfortably on his or her own. Endothelial progenitor cells (EPCs) are crucial for MDO-related angiogenesis. Moreover, emerging evidence suggests that heat shock protein 20 (Hsp20) modulates angiogenesis under hypoxic conditions. However, the specific role of Hsp20 in EPCs, in the context of MDO, is not yet known. The aim of this study was to explore the expression of Hsp20 during MDO and the effects of Hsp20 on EPCs under hypoxia. METHODS Mandibular distraction osteogenesis and mandibular bone defect (MBD) canine model were established. The expression of CD34, CD133, HIF-1α, and Hsp20 in callus was detected by immunofluorescence on day 14 after surgery. Canine bone marrow EPCs were cultured, with or without optimal cobalt chloride (CoCl2) concentration. Hypoxic effects, caused by CoCl2, were evaluated by means of the cell cycle, cell apoptosis, transwell cell migration, and tube formation assays. The Hsp20/KDR/PI3K/Akt expression levels were evaluated via immunofluorescence, RT-qPCR, and western blot. Next, EPCs were incorporated with either Hsp20-overexpression or Hsp20-siRNA lentivirus. The resulting effects were evaluated as described above. RESULTS CD34, CD133, HIF-1α, and Hsp20 were displayed more positive in the callus of MDO compared with MBD. In addition, hypoxic conditions, generated by 0.1 mM CoCl2, in canine EPCs, accelerated cell proliferation, migration, tube formation, and Hsp20 expression. Hsp20 overexpression in EPCs significantly stimulated cell proliferation, migration, and tube formation, whereas Hsp20 inhibition produced the opposite effect. Additionally, the molecular mechanism was partly dependent on the KDR/PI3K/Akt pathway. CONCLUSION In summary, herein, we present a novel mechanism of Hsp20-mediated regulation of canine EPCs via Akt activation in a hypoxic microenvironment.
Collapse
Affiliation(s)
- Zhiqi Han
- Guangxi Medical University, Nanning, Guangxi, 530021, People's Republic of China
- Department of Oral and Maxillofacial Surgery, College of Stomatology, Hospital of Stomatology, Guangxi Medical University, Nanning, Guangxi, 530021, People's Republic of China
- Guangxi Key Laboratory of Oral and Maxillofacial Rehabilitation and Reconstruction, Guangxi Key Laboratory of Oral and Maxillofacial Surgery Disease Treatment, Nanning, Guangxi, 530021, People's Republic of China
- Guangxi Clinical Research Center for Craniofacial Deformity, Nanning, Guangxi, 530021, People's Republic of China
| | - Xuan He
- Guangxi Medical University, Nanning, Guangxi, 530021, People's Republic of China
- Department of Oral and Maxillofacial Surgery, College of Stomatology, Hospital of Stomatology, Guangxi Medical University, Nanning, Guangxi, 530021, People's Republic of China
- Guangxi Key Laboratory of Oral and Maxillofacial Rehabilitation and Reconstruction, Guangxi Key Laboratory of Oral and Maxillofacial Surgery Disease Treatment, Nanning, Guangxi, 530021, People's Republic of China
- Guangxi Clinical Research Center for Craniofacial Deformity, Nanning, Guangxi, 530021, People's Republic of China
| | - Yuan Feng
- Guangxi Medical University, Nanning, Guangxi, 530021, People's Republic of China
- Department of Oral and Maxillofacial Surgery, College of Stomatology, Hospital of Stomatology, Guangxi Medical University, Nanning, Guangxi, 530021, People's Republic of China
- Guangxi Key Laboratory of Oral and Maxillofacial Rehabilitation and Reconstruction, Guangxi Key Laboratory of Oral and Maxillofacial Surgery Disease Treatment, Nanning, Guangxi, 530021, People's Republic of China
- Guangxi Clinical Research Center for Craniofacial Deformity, Nanning, Guangxi, 530021, People's Republic of China
| | - Weidong Jiang
- Guangxi Medical University, Nanning, Guangxi, 530021, People's Republic of China
- Department of Oral and Maxillofacial Surgery, College of Stomatology, Hospital of Stomatology, Guangxi Medical University, Nanning, Guangxi, 530021, People's Republic of China
- Guangxi Key Laboratory of Oral and Maxillofacial Rehabilitation and Reconstruction, Guangxi Key Laboratory of Oral and Maxillofacial Surgery Disease Treatment, Nanning, Guangxi, 530021, People's Republic of China
- Guangxi Clinical Research Center for Craniofacial Deformity, Nanning, Guangxi, 530021, People's Republic of China
| | - Nuo Zhou
- Guangxi Medical University, Nanning, Guangxi, 530021, People's Republic of China.
- Department of Oral and Maxillofacial Surgery, College of Stomatology, Hospital of Stomatology, Guangxi Medical University, Nanning, Guangxi, 530021, People's Republic of China.
- Guangxi Key Laboratory of Oral and Maxillofacial Rehabilitation and Reconstruction, Guangxi Key Laboratory of Oral and Maxillofacial Surgery Disease Treatment, Nanning, Guangxi, 530021, People's Republic of China.
- Guangxi Clinical Research Center for Craniofacial Deformity, Nanning, Guangxi, 530021, People's Republic of China.
| | - Xuanping Huang
- Guangxi Medical University, Nanning, Guangxi, 530021, People's Republic of China.
- Department of Oral and Maxillofacial Surgery, College of Stomatology, Hospital of Stomatology, Guangxi Medical University, Nanning, Guangxi, 530021, People's Republic of China.
- Guangxi Key Laboratory of Oral and Maxillofacial Rehabilitation and Reconstruction, Guangxi Key Laboratory of Oral and Maxillofacial Surgery Disease Treatment, Nanning, Guangxi, 530021, People's Republic of China.
- Guangxi Clinical Research Center for Craniofacial Deformity, Nanning, Guangxi, 530021, People's Republic of China.
| |
Collapse
|
4
|
Pignatelli C, Campo F, Neroni A, Piemonti L, Citro A. Bioengineering the Vascularized Endocrine Pancreas: A Fine-Tuned Interplay Between Vascularization, Extracellular-Matrix-Based Scaffold Architecture, and Insulin-Producing Cells. Transpl Int 2022; 35:10555. [PMID: 36090775 PMCID: PMC9452644 DOI: 10.3389/ti.2022.10555] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 08/11/2022] [Indexed: 11/23/2022]
Abstract
Intrahepatic islet transplantation is a promising β-cell replacement strategy for the treatment of type 1 diabetes. Instant blood-mediated inflammatory reactions, acute inflammatory storm, and graft revascularization delay limit islet engraftment in the peri-transplant phase, hampering the success rate of the procedure. Growing evidence has demonstrated that islet engraftment efficiency may take advantage of several bioengineering approaches aimed to recreate both vascular and endocrine compartments either ex vivo or in vivo. To this end, endocrine pancreas bioengineering is an emerging field in β-cell replacement, which might provide endocrine cells with all the building blocks (vascularization, ECM composition, or micro/macro-architecture) useful for their successful engraftment and function in vivo. Studies on reshaping either the endocrine cellular composition or the islet microenvironment have been largely performed, focusing on a single building block element, without, however, grasping that their synergistic effect is indispensable for correct endocrine function. Herein, the review focuses on the minimum building blocks that an ideal vascularized endocrine scaffold should have to resemble the endocrine niche architecture, composition, and function to foster functional connections between the vascular and endocrine compartments. Additionally, this review highlights the possibility of designing bioengineered scaffolds integrating alternative endocrine sources to overcome donor organ shortages and the possibility of combining novel immune-preserving strategies for long-term graft function.
Collapse
Affiliation(s)
- Cataldo Pignatelli
- San Raffaele Diabetes Research Institute, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Francesco Campo
- San Raffaele Diabetes Research Institute, IRCCS San Raffaele Scientific Institute, Milan, Italy
- Università Vita-Salute San Raffaele, Milan, Italy
| | - Alessia Neroni
- San Raffaele Diabetes Research Institute, IRCCS San Raffaele Scientific Institute, Milan, Italy
- Università Vita-Salute San Raffaele, Milan, Italy
| | - Lorenzo Piemonti
- San Raffaele Diabetes Research Institute, IRCCS San Raffaele Scientific Institute, Milan, Italy
- Università Vita-Salute San Raffaele, Milan, Italy
| | - Antonio Citro
- San Raffaele Diabetes Research Institute, IRCCS San Raffaele Scientific Institute, Milan, Italy
| |
Collapse
|
5
|
Ghezelayagh Z, Zabihi M, Kazemi Ashtiani M, Ghezelayagh Z, Lynn FC, Tahamtani Y. Recapitulating pancreatic cell-cell interactions through bioengineering approaches: the momentous role of non-epithelial cells for diabetes cell therapy. Cell Mol Life Sci 2021; 78:7107-7132. [PMID: 34613423 PMCID: PMC11072828 DOI: 10.1007/s00018-021-03951-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Revised: 09/09/2021] [Accepted: 09/23/2021] [Indexed: 12/11/2022]
Abstract
Over the past few years, extensive efforts have been made to generate in-vitro pancreatic micro-tissue, for disease modeling or cell replacement approaches in pancreatic related diseases such as diabetes mellitus. To obtain these goals, a closer look at the diverse cells participating in pancreatic development is necessary. Five major non-epithelial pancreatic (pN-Epi) cell populations namely, pancreatic endothelium, mesothelium, neural crests, pericytes, and stellate cells exist in pancreas throughout its development, and they are hypothesized to be endogenous inducers of the development. In this review, we discuss different pN-Epi cells migrating to and existing within the pancreas and their diverse effects on pancreatic epithelium during organ development mediated via associated signaling pathways, soluble factors or mechanical cell-cell interactions. In-vivo and in-vitro experiments, with a focus on N-Epi cells' impact on pancreas endocrine development, have also been considered. Pluripotent stem cell technology and multicellular three-dimensional organoids as new approaches to generate pancreatic micro-tissues have also been discussed. Main challenges for reaching a detailed understanding of the role of pN-Epi cells in pancreas development in utilizing for in-vitro recapitulation have been summarized. Finally, various novel and innovative large-scale bioengineering approaches which may help to recapitulate cell-cell interactions and are crucial for generation of large-scale in-vitro multicellular pancreatic micro-tissues, are discussed.
Collapse
Affiliation(s)
- Zahra Ghezelayagh
- Department of Developmental Biology, Faculty of Basic Sciences and Advanced Technologies in Biology, University of Science and Culture, ACECR, Tehran, Iran
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
| | - Mahsa Zabihi
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
- Department of Genetics, Faculty of Basic Sciences and Advanced Technologies in Biology, University of Science and Culture, ACECR, Tehran, Iran
| | - Mohammad Kazemi Ashtiani
- Department of Cell Engineering, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
| | - Zeinab Ghezelayagh
- Department of Developmental Biology, Faculty of Basic Sciences and Advanced Technologies in Biology, University of Science and Culture, ACECR, Tehran, Iran
- Department of Embryology, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran
| | - Francis C Lynn
- Diabetes Research Group, BC Children's Hospital Research Institute, Vancouver, BC, Canada
- Department of Surgery and School of Biomedical Engineering , University of British Columbia, Vancouver, BC, Canada
| | - Yaser Tahamtani
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran.
- Reproductive Epidemiology Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran.
| |
Collapse
|
6
|
Cell-based therapies for vascular regeneration: Past, present and future. Pharmacol Ther 2021; 231:107976. [PMID: 34480961 DOI: 10.1016/j.pharmthera.2021.107976] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 06/01/2021] [Accepted: 08/05/2021] [Indexed: 12/27/2022]
Abstract
Tissue vascularization remains one of the outstanding challenges in regenerative medicine. Beyond its role in circulating oxygen and nutrients, the vasculature is critical for organ development, function and homeostasis. Importantly, effective vascular regeneration is key in generating large 3D tissues for regenerative medicine applications to enable the survival of cells post-transplantation, organ growth, and integration into the host system. Therefore, the absence of clinically applicable means of (re)generating vessels is one of the main obstacles in cell replacement therapy. In this review, we highlight cell-based vascularization strategies which demonstrate clinical potential, discuss their strengths and limitations and highlight the main obstacles hindering cell-based therapeutic vascularization.
Collapse
|
7
|
Akolpoglu MB, Inceoglu Y, Bozuyuk U, Sousa AR, Oliveira MB, Mano JF, Kizilel S. Recent advances in the design of implantable insulin secreting heterocellular islet organoids. Biomaterials 2020; 269:120627. [PMID: 33401104 DOI: 10.1016/j.biomaterials.2020.120627] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 12/14/2020] [Accepted: 12/18/2020] [Indexed: 12/11/2022]
Abstract
Islet transplantation has proved one of the most remarkable transmissions from an experimental curiosity into a routine clinical application for the treatment of type I diabetes (T1D). Current efforts for taking this technology one-step further are now focusing on overcoming islet donor shortage, engraftment, prolonged islet availability, post-transplant vascularization, and coming up with new strategies to eliminate lifelong immunosuppression. To this end, insulin secreting 3D cell clusters composed of different types of cells, also referred as heterocellular islet organoids, spheroids, or pseudoislets, have been engineered to overcome the challenges encountered by the current islet transplantation protocols. β-cells or native islets are accompanied by helper cells, also referred to as accessory cells, to generate a cell cluster that is not only able to accurately secrete insulin in response to glucose, but also superior in terms of other key features (e.g. maintaining a vasculature, longer durability in vivo and not necessitating immunosuppression after transplantation). Over the past decade, numerous 3D cell culture techniques have been integrated to create an engineered heterocellular islet organoid that addresses current obstacles. Here, we first discuss the different cell types used to prepare heterocellular organoids for islet transplantation and their contribution to the organoids design. We then introduce various cell culture techniques that are incorporated to prepare a fully functional and insulin secreting organoids with select features. Finally, we discuss the challenges and present a future outlook for improving clinical outcomes of islet transplantation.
Collapse
Affiliation(s)
- M Birgul Akolpoglu
- Chemical and Biological Engineering, Koc University, Sariyer, 34450, Istanbul, Turkey
| | - Yasemin Inceoglu
- Chemical and Biological Engineering, Koc University, Sariyer, 34450, Istanbul, Turkey
| | - Ugur Bozuyuk
- Chemical and Biological Engineering, Koc University, Sariyer, 34450, Istanbul, Turkey
| | - Ana Rita Sousa
- Department of Chemistry, CICECO - Aveiro Institute of Materials. University of Aveiro. Campus Universitário de Santiago. 3810-193 Aveiro. Portugal
| | - Mariana B Oliveira
- Department of Chemistry, CICECO - Aveiro Institute of Materials. University of Aveiro. Campus Universitário de Santiago. 3810-193 Aveiro. Portugal.
| | - João F Mano
- Department of Chemistry, CICECO - Aveiro Institute of Materials. University of Aveiro. Campus Universitário de Santiago. 3810-193 Aveiro. Portugal
| | - Seda Kizilel
- Chemical and Biological Engineering, Koc University, Sariyer, 34450, Istanbul, Turkey.
| |
Collapse
|
8
|
Liao G, Zheng K, Shorr R, Allan DS. Human endothelial colony-forming cells in regenerative therapy: A systematic review of controlled preclinical animal studies. Stem Cells Transl Med 2020; 9:1344-1352. [PMID: 32681814 PMCID: PMC7581447 DOI: 10.1002/sctm.20-0141] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 05/11/2020] [Accepted: 05/24/2020] [Indexed: 12/11/2022] Open
Abstract
Endothelial colony‐forming cells (ECFCs) hold significant promise as candidates for regenerative therapy of vascular injury. Existing studies remain largely preclinical and exhibit marked design heterogeneity. A systematic review of controlled preclinical trials of human ECFCs is needed to guide future study design and to accelerate clinical translation. A systematic search of Medline and EMBASE on 1 April 2019 returned 3131 unique entries of which 66 fulfilled the inclusion criteria. Most studies used ECFCs derived from umbilical cord or adult peripheral blood. Studies used genetically modified immunodeficient mice (n = 52) and/or rats (n = 16). ECFC phenotypes were inconsistently characterized. While >90% of studies used CD31+ and CD45−, CD14− was demonstrated in 73% of studies, CD146+ in 42%, and CD10+ in 35%. Most disease models invoked ischemia. Peripheral vascular ischemia (n = 29), central nervous system ischemia (n = 14), connective tissue injury (n = 10), and cardiovascular ischemia and reperfusion injury (n = 7) were studied most commonly. Studies showed predominantly positive results; only 13 studies reported ≥1 outcome with null results, three reported only null results, and one reported harm. Quality assessment with SYRCLE revealed potential sources of bias in most studies. Preclinical ECFC studies are associated with benefit across several ischemic conditions in animal models, although combining results is limited by marked heterogeneity in study design. In particular, characterization of ECFCs varied and aspects of reporting introduced risk of bias in most studies. More studies with greater focus on standardized cell characterization and consistency of the disease model are needed.
Collapse
Affiliation(s)
- Gary Liao
- Clinical Epidemiology and Regenerative Medicine Programs, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.,Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Katina Zheng
- Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Risa Shorr
- Information Services, The Ottawa Hospital, Ottawa, Ontario, Canada
| | - David S Allan
- Clinical Epidemiology and Regenerative Medicine Programs, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.,Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| |
Collapse
|
9
|
Rambøl MH, Han E, Niklason LE. Microvessel Network Formation and Interactions with Pancreatic Islets in Three-Dimensional Chip Cultures. Tissue Eng Part A 2020; 26:556-568. [PMID: 31724494 PMCID: PMC7249478 DOI: 10.1089/ten.tea.2019.0186] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 11/01/2019] [Indexed: 12/13/2022] Open
Abstract
The pancreatic islet is a highly vascularized micro-organ, and rapid revascularization postislet transplantation is important for islet survival and function. However, the various mechanisms involved in islet revascularization are not fully understood, and we currently lack good in vitro platforms to explore this. Our aim for this study was to generate perfusable microvascular networks in a microfluidic chip device, in which islets could be easily integrated, to establish an in vitro platform for investigations on islet-microvasculature interactions. We compared the ability of mesenchymal stem cells (MSCs) and fibroblasts to support microvascular network formation by human umbilical vein endothelial cells (HUVECs) and human induced pluripotent stem cell-derived endothelial colony-forming cell in two-dimensional and three-dimensional models of angiogenesis, and tested the effect of different culture media on microvessel formation. HUVECs that were supported by MSCs formed patent and perfusable networks in a fibrin gel, whereas networks supported by fibroblasts rapidly regressed. Network morphology could be controlled by adjusting relative cell numbers and densities. Incorporation of isolated rat islets demonstrated that islets recruit local microvasculature in vitro, but that the microvessels did not invade islets, at least during the course of these studies. This in vitro microvascularization platform can provide a useful tool to study how various parameters affect islet integration with microvascular networks and could also be utilized for studies of vascularization of other organ systems. Impact statement To improve pancreatic islet graft survival and function posttransplantation, rapid and adequate revascularization is critical. Efforts to improve islet revascularization are demanding due to an insufficient understanding of the mechanisms involved in the process. We have applied a microfluidics platform to generate microvascular networks, and by incorporating pancreatic islets, we were able to study microvasculature-islet interactions in real time. This platform can provide a useful tool to study islet integration with microvascular networks, and could be utilized for studies of vascularization of other organ systems. Moreover, this work may be adapted toward developing a prevascularized islet construct for transplantation.
Collapse
Affiliation(s)
- Mia H. Rambøl
- Department of Molecular Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Edward Han
- Department of Biomedical Engineering and Yale University, New Haven, Connecticut, USA
- Department of Anesthesiology, Yale University, New Haven, Connecticut, USA
| | - Laura E. Niklason
- Department of Biomedical Engineering and Yale University, New Haven, Connecticut, USA
- Department of Anesthesiology, Yale University, New Haven, Connecticut, USA
| |
Collapse
|
10
|
Bowles AC, Ishahak MM, Glover SJ, Correa D, Agarwal A. Evaluating Vascularization of Heterotopic Islet Constructs for Type 1 Diabetes Using an In Vitro Platform. Integr Biol (Camb) 2020; 11:331-341. [PMID: 31724717 DOI: 10.1093/intbio/zyz027] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 09/03/2019] [Accepted: 09/04/2019] [Indexed: 12/20/2022]
Abstract
Type 1 diabetes (T1D) results from the autoimmune destruction of β-cells within the pancreatic islets of Langerhans. Clinical islet transplantation from healthy donors is proposed to ameliorate symptoms, improve quality of life, and enhance the life span of afflicted T1D patients. However, post-transplant outcomes are dependent on the survival of the transplanted islets, which relies on the engraftment of the islets with the recipient's vasculature among other factors. Treatment strategies to improve engraftment include combining islets with supporting cells including endothelial cells (EC) and mesenchymal stem cells (MSC), dynamic cells capable of robust immunomodulatory and vasculogenic effects. In this study, we developed an in vitro model of transplantation to investigate the cellular mechanisms that enhance rapid vascularization of heterotopic islet constructs. Self-assembled vascular beds of fluorescently stained EC served as reproducible in vitro transplantation sites. Heterotopic islet constructs composed of islets, EC, and MSC were transferred to vascular beds for modeling transplantation. Time-lapsed imaging was performed for analysis of the vascular bed remodeling for parameters of neo-vascularization. Moreover, sampling of media following modeled transplantation showed secretory profiles that were correlated with imaging analyses as well as with islet function using glucose-stimulated insulin secretion. Together, evidence revealed that heterotopic constructs consisting of islets, EC, and MSC exhibited the most rapid recruitment and robust branching of cells from the vascular beds suggesting enhanced neo-vascularization compared to islets alone and control constructs. Together, this evidence supports a promising cell transplantation strategy for T1D and also demonstrates a valuable tool for rapidly investigating candidate cellular therapies for transplantation.
Collapse
Affiliation(s)
- Annie C Bowles
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, USA.,DJTMF Biomedical Nanotechnology Institute at the University of Miami, Miami, FL, USA.,Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL, USA.,Department of Orthopaedics, UHealth Sports Medicine Institute, University of Miami, Miami, FL, USA
| | - Matthew M Ishahak
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, USA.,DJTMF Biomedical Nanotechnology Institute at the University of Miami, Miami, FL, USA
| | - Samuel J Glover
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, USA
| | - Diego Correa
- DJTMF Biomedical Nanotechnology Institute at the University of Miami, Miami, FL, USA.,Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL, USA.,Department of Orthopaedics, UHealth Sports Medicine Institute, University of Miami, Miami, FL, USA
| | - Ashutosh Agarwal
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, USA.,DJTMF Biomedical Nanotechnology Institute at the University of Miami, Miami, FL, USA.,Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL, USA
| |
Collapse
|
11
|
Thakur G, Lee HJ, Jeon RH, Lee SL, Rho GJ. Small Molecule-Induced Pancreatic β-Like Cell Development: Mechanistic Approaches and Available Strategies. Int J Mol Sci 2020; 21:E2388. [PMID: 32235681 PMCID: PMC7178115 DOI: 10.3390/ijms21072388] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Revised: 03/26/2020] [Accepted: 03/26/2020] [Indexed: 02/06/2023] Open
Abstract
Diabetes is a metabolic disease which affects not only glucose metabolism but also lipid and protein metabolism. It encompasses two major types: type 1 and 2 diabetes. Despite the different etiologies of type 1 and 2 diabetes mellitus (T1DM and T2DM, respectively), the defining features of the two forms are insulin deficiency and resistance, respectively. Stem cell therapy is an efficient method for the treatment of diabetes, which can be achieved by differentiating pancreatic β-like cells. The consistent generation of glucose-responsive insulin releasing cells remains challenging. In this review article, we present basic concepts of pancreatic organogenesis, which intermittently provides a basis for engineering differentiation procedures, mainly based on the use of small molecules. Small molecules are more auspicious than any other growth factors, as they have unique, valuable properties like cell-permeability, as well as a nonimmunogenic nature; furthermore, they offer immense benefits in terms of generating efficient functional beta-like cells. We also summarize advances in the generation of stem cell-derived pancreatic cell lineages, especially endocrine β-like cells or islet organoids. The successful induction of stem cells depends on the quantity and quality of available stem cells and the efficient use of small molecules.
Collapse
Affiliation(s)
- Gitika Thakur
- Department of Theriogenology and Biotechnology, College of Veterinary Medicine and Research Institute of Life Science, Gyeongsang National University, Jinju 52828, Korea; (G.T.); (H.-J.L.); (S.-L.L.)
| | - Hyeon-Jeong Lee
- Department of Theriogenology and Biotechnology, College of Veterinary Medicine and Research Institute of Life Science, Gyeongsang National University, Jinju 52828, Korea; (G.T.); (H.-J.L.); (S.-L.L.)
| | - Ryoung-Hoon Jeon
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN 55905, USA;
| | - Sung-Lim Lee
- Department of Theriogenology and Biotechnology, College of Veterinary Medicine and Research Institute of Life Science, Gyeongsang National University, Jinju 52828, Korea; (G.T.); (H.-J.L.); (S.-L.L.)
| | - Gyu-Jin Rho
- Department of Theriogenology and Biotechnology, College of Veterinary Medicine and Research Institute of Life Science, Gyeongsang National University, Jinju 52828, Korea; (G.T.); (H.-J.L.); (S.-L.L.)
| |
Collapse
|
12
|
Nguyen TT, Emami F, Yook S, Nguyen HT, Pham TT, Pathak S, Regmi S, Kim JO, Yong CS, Kim JR, Jeong JH. Local release of NECA (5'-(N-ethylcarboxamido)adenosine) from implantable polymeric sheets for enhanced islet revascularization in extrahepatic transplantation site. J Control Release 2020; 321:509-518. [PMID: 32087300 DOI: 10.1016/j.jconrel.2020.02.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Revised: 02/06/2020] [Accepted: 02/16/2020] [Indexed: 12/20/2022]
Abstract
Clinical intraportal pancreatic islet infusion is popular for treating type I diabetes. However, multiple doses of islets and anti-rejection protocols are needed to compensate for early large cell losses post-infusion due to the harsh hepatic environment. Thus, extrahepatic sites are utilized to enable efficient islet engraftment and reduce islet mass. Here, we reported an effective islet revascularization protocol that was based on the co-implantation of islet/fibrin gel construct with poly(lactic-co-glycolic) acid sheet releasing NECA (5'-(N-ethylcarboxamido) adenosine; a potent agonist of adenosine) into mouse epididymal fat pad. Thin, flexible sheets (d = 4 mm) prepared by simple casting exhibited sustained NECA release for up to 21 days, which effectively improved early islet engraftment with a median diabetic reversal time of 18.5 days. Western blotting revealed the facilitative effect of NECA on VEGF expression from islets in vitro and from grafts in vivo. In addition, NECA directly promoted the angiogenic activities of islet-derived endothelial cells by enhancing their proliferation and vessel-like tube formation. As a result, neovasculatures were effectively formed in the engrafted islet vicinity, as evidenced by vasculature imaging and immunofluorescence. Taken together, we suggest NECA-releasing PLGA sheets offer a safe and effective drug delivery system that enhances islet engraftment while reducing islet mass at extrahepatic sites for clinical relevance.
Collapse
Affiliation(s)
- Tiep Tien Nguyen
- College of Pharmacy, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Republic of Korea
| | - Fakhrossadat Emami
- College of Pharmacy, Keimyung University, Daegu 42601, Republic of Korea
| | - Simmyung Yook
- College of Pharmacy, Keimyung University, Daegu 42601, Republic of Korea.
| | - Hanh Thuy Nguyen
- College of Pharmacy, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Republic of Korea
| | - Tung Thanh Pham
- College of Pharmacy, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Republic of Korea
| | - Shiva Pathak
- College of Pharmacy, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Republic of Korea
| | - Shobha Regmi
- College of Pharmacy, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Republic of Korea
| | - Jong Oh Kim
- College of Pharmacy, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Republic of Korea
| | - Chul Soon Yong
- College of Pharmacy, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Republic of Korea
| | - Jae-Ryong Kim
- Department of Biochemistry and Molecular Biology and Smart-Aging Convergence Research Center, College of Medicine, Yeungnam University, Daegu 42415, Republic of Korea
| | - Jee-Heon Jeong
- College of Pharmacy, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Republic of Korea.
| |
Collapse
|
13
|
Staels W, Heremans Y, Heimberg H, De Leu N. VEGF-A and blood vessels: a beta cell perspective. Diabetologia 2019; 62:1961-1968. [PMID: 31414144 DOI: 10.1007/s00125-019-4969-z] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 06/11/2019] [Indexed: 02/07/2023]
Abstract
Reciprocal signalling between the endothelium and the pancreatic epithelium is crucial for coordinated differentiation of the embryonic endocrine and exocrine pancreas. In the adult pancreas, islets depend on their dense capillary network to adequately respond to changes in plasma glucose levels. Vascular changes contribute to the onset and progression of both type 1 and type 2 diabetes. Impaired revascularisation of islets transplanted in individuals with type 1 diabetes is linked to islet graft failure and graft loss. This review summarises our understanding of the role of vascular endothelial growth factor-A (VEGF-A) and endothelial cells in beta cell development, physiology and disease. In addition, the therapeutic potential of modulating VEGF-A levels in beta and beta-like cells for transplantation is discussed.
Collapse
Affiliation(s)
- Willem Staels
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium
- Institut Cochin, CNRS, INSERM, Université de Paris, F-75014, Paris, France
| | - Yves Heremans
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium
| | - Harry Heimberg
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium
| | - Nico De Leu
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium.
- Department of Endocrinology, UZ Brussel, Brussels, Belgium.
- Department of Endocrinology, ASZ Aalst, Aalst, Belgium.
| |
Collapse
|
14
|
Merola J, Reschke M, Pierce RW, Qin L, Spindler S, Baltazar T, Manes TD, Lopez-Giraldez F, Li G, Bracaglia LG, Xie C, Kirkiles-Smith N, Saltzman WM, Tietjen GT, Tellides G, Pober JS. Progenitor-derived human endothelial cells evade alloimmunity by CRISPR/Cas9-mediated complete ablation of MHC expression. JCI Insight 2019; 4:129739. [PMID: 31527312 PMCID: PMC6824302 DOI: 10.1172/jci.insight.129739] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 09/11/2019] [Indexed: 12/20/2022] Open
Abstract
Tissue engineering may address organ shortages currently limiting clinical transplantation. Off-the-shelf engineered vascularized organs will likely use allogeneic endothelial cells (ECs) to construct microvessels required for graft perfusion. Vasculogenic ECs can be differentiated from committed progenitors (human endothelial colony-forming cells or HECFCs) without risk of mutation or teratoma formation associated with reprogrammed stem cells. Like other ECs, these cells can express both class I and class II major histocompatibility complex (MHC) molecules, bind donor-specific antibody (DSA), activate alloreactive T effector memory cells, and initiate rejection in the absence of donor leukocytes. CRISPR/Cas9-mediated dual ablation of β2-microglobulin and class II transactivator (CIITA) in HECFC-derived ECs eliminates both class I and II MHC expression while retaining EC functions and vasculogenic potential. Importantly, dually ablated ECs no longer bind human DSA or activate allogeneic CD4+ effector memory T cells and are resistant to killing by CD8+ alloreactive cytotoxic T lymphocytes in vitro and in vivo. Despite absent class I MHC molecules, these ECs do not activate or elicit cytotoxic activity from allogeneic natural killer cells. These data suggest that HECFC-derived ECs lacking MHC molecule expression can be utilized for engineering vascularized grafts that evade allorejection.
Collapse
Affiliation(s)
- Jonathan Merola
- Department of Surgery, Yale School of Medicine, New Haven, Connecticut, USA
| | - Melanie Reschke
- Department of Biomedical Engineering, Yale School of Engineering and Applied Science, New Haven, Connecticut, USA
| | | | - Lingfeng Qin
- Department of Surgery, Yale School of Medicine, New Haven, Connecticut, USA
| | - Susann Spindler
- Department of Surgery, Yale School of Medicine, New Haven, Connecticut, USA
| | - Tania Baltazar
- Department of Immunobiology, Yale School of Medicine, New Haven, Connecticut, USA
| | - Thomas D. Manes
- Department of Immunobiology, Yale School of Medicine, New Haven, Connecticut, USA
| | - Francesc Lopez-Giraldez
- Yale Center for Genome Analysis and Department of Genetics, Yale University, New Haven, Connecticut, USA
| | - Guangxin Li
- Department of Surgery, Yale School of Medicine, New Haven, Connecticut, USA
| | - Laura G. Bracaglia
- Department of Biomedical Engineering, Yale School of Engineering and Applied Science, New Haven, Connecticut, USA
| | - Catherine Xie
- Department of Immunobiology, Yale School of Medicine, New Haven, Connecticut, USA
| | - Nancy Kirkiles-Smith
- Department of Immunobiology, Yale School of Medicine, New Haven, Connecticut, USA
| | - W. Mark Saltzman
- Department of Biomedical Engineering, Yale School of Engineering and Applied Science, New Haven, Connecticut, USA
| | - Gregory T. Tietjen
- Department of Surgery, Yale School of Medicine, New Haven, Connecticut, USA
| | - George Tellides
- Department of Surgery, Yale School of Medicine, New Haven, Connecticut, USA
| | - Jordan S. Pober
- Department of Immunobiology, Yale School of Medicine, New Haven, Connecticut, USA
| |
Collapse
|
15
|
Replica moulded poly(dimethylsiloxane) microwell arrays induce localized endothelial cell immobilization for coculture with pancreatic islets. Biointerphases 2019; 14:011002. [PMID: 30700091 DOI: 10.1116/1.5087737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
PolyJet three-dimensional (3D) printing allows for the rapid manufacturing of 3D moulds for the fabrication of cross-linked poly(dimethylsiloxane) microwell arrays (PMAs). As this 3D printing technique has a resolution on the micrometer scale, the moulds exhibit a distinct surface roughness. In this study, the authors demonstrate by optical profilometry that the topography of the 3D printed moulds can be transferred to the PMAs and that this roughness induced cell adhesive properties to the material. In particular, the topography facilitated immobilization of endothelial cells on the internal walls of the microwells. The authors also demonstrate that upon immobilization of endothelial cells to the microwells, a second population of cells, namely, pancreatic islets could be introduced, thus producing a 3D coculture platform.
Collapse
|
16
|
Kim J, Shim IK, Hwang DG, Lee YN, Kim M, Kim H, Kim SW, Lee S, Kim SC, Cho DW, Jang J. 3D cell printing of islet-laden pancreatic tissue-derived extracellular matrix bioink constructs for enhancing pancreatic functions. J Mater Chem B 2019; 7:1773-1781. [PMID: 32254919 DOI: 10.1039/c8tb02787k] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Type 1 diabetes mellitus (T1DM) is a form of diabetes that inhibits or halts insulin production in the pancreas. Although various therapeutic options are applied in clinical settings, not all patients are treatable with such methods due to the instability of the T1DM or the unawareness of hypoglycemia. Islet transplantation using a tissue engineering-based approach may mark a clinical significance, but finding ways to increase the function of islets in 3D constructs is a major challenge. In this study, we suggest pancreatic tissue-derived extracellular matrix as a potential candidate to recapitulate the native microenvironment in transplantable 3D pancreatic tissues. Notably, insulin secretion and the maturation of insulin-producing cells derived from human pluripotent stem cells were highly up-regulated when cultured in pdECM bioink. In addition, co-culture with human umbilical vein-derived endothelial cells decreased the central necrosis of islets under 3D culture conditions. Through the convergence of 3D cell printing technology, we validated the possibility of fabricating 3D constructs of a therapeutically applicable transplant size that can potentially be an allogeneic source of islets, such as patient-induced pluripotent stem cell-derived insulin-producing cells.
Collapse
Affiliation(s)
- Jaewook Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Korea.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Keighron C, Lyons CJ, Creane M, O'Brien T, Liew A. Recent Advances in Endothelial Progenitor Cells Toward Their Use in Clinical Translation. Front Med (Lausanne) 2018; 5:354. [PMID: 30619864 PMCID: PMC6305310 DOI: 10.3389/fmed.2018.00354] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 12/03/2018] [Indexed: 12/28/2022] Open
Abstract
Since the discovery of Endothelial Progenitor Cells (EPC) by Asahara and colleagues in 1997, an increasing number of preclinical studies have shown that EPC based therapy is feasible, safe, and efficacious in multiple disease states. Subsequently, this has led to several, mainly early phase, clinical trials demonstrating the feasibility and safety profile of EPC therapy, with the suggestion of efficacy in several conditions including ischemic heart disease, pulmonary arterial hypertension and decompensated liver cirrhosis. Despite the use of the common term “EPC,” the characteristics, manufacturing methods and subset of the cell type used in these studies often vary significantly, rendering clinical translation challenging. It has recently been acknowledged that the true EPC is the endothelial colony forming cells (ECFC). The objective of this review was to summarize and critically appraise the registered and published clinical studies using the term “EPC,” which encompasses a heterogeneous cell population, as a therapeutic agent. Furthermore, the preclinical data using ECFC from the PubMed and Web of Science databases were searched and analyzed. We noted that despite the promising effect of ECFC on vascular regeneration, no clinical study has stemmed from these preclinical studies. We showed that there is a lack of information registered on www.clinicaltrials.gov for EPC clinical trials, specifically on cell culture methods. We also highlighted the importance of a detailed definition of the cell type used in EPC clinical trials to facilitate comparisons between trials and better understanding of the potential clinical benefit of EPC based therapy. We concluded our review by discussing the potential and limitations of EPC based therapy in clinical settings.
Collapse
Affiliation(s)
- Cameron Keighron
- Regenerative Medicine Institute, National Centre for Biomedical Engineering Science and Centre for Research in Medical Devices, National University of Ireland, Galway, Ireland
| | - Caomhán J Lyons
- Regenerative Medicine Institute, National Centre for Biomedical Engineering Science and Centre for Research in Medical Devices, National University of Ireland, Galway, Ireland
| | - Michael Creane
- Regenerative Medicine Institute, National Centre for Biomedical Engineering Science and Centre for Research in Medical Devices, National University of Ireland, Galway, Ireland
| | - Timothy O'Brien
- Regenerative Medicine Institute, National Centre for Biomedical Engineering Science and Centre for Research in Medical Devices, National University of Ireland, Galway, Ireland
| | - Aaron Liew
- Regenerative Medicine Institute, National Centre for Biomedical Engineering Science and Centre for Research in Medical Devices, National University of Ireland, Galway, Ireland
| |
Collapse
|
18
|
Perez-Basterrechea M, Esteban MM, Vega JA, Obaya AJ. Tissue-engineering approaches in pancreatic islet transplantation. Biotechnol Bioeng 2018; 115:3009-3029. [PMID: 30144310 DOI: 10.1002/bit.26821] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 08/08/2018] [Accepted: 08/14/2018] [Indexed: 12/15/2022]
Abstract
Pancreatic islet transplantation is a promising alternative to whole-pancreas transplantation as a treatment of type 1 diabetes mellitus. This technique has been extensively developed during the past few years, with the main purpose of minimizing the complications arising from the standard protocols used in organ transplantation. By using a variety of strategies used in tissue engineering and regenerative medicine, pancreatic islets have been successfully introduced in host patients with different outcomes in terms of islet survival and functionality, as well as the desired normoglycemic control. Here, we describe and discuss those strategies to transplant islets together with different scaffolds, in combination with various cell types and diffusible factors, and always with the aim of reducing host immune response and achieving islet survival, regardless of the site of transplantation.
Collapse
Affiliation(s)
- Marcos Perez-Basterrechea
- Unidad de Terapia Celular y Medicina Regenerativa, Servicio de Hematología y Hemoterapia, Hospital Universitario Central de Asturias (HUCA), Oviedo, Spain.,Plataforma de Terapias Avanzadas, Instituto de Investigación Biosanitaria del Principado de Asturias (ISPA), Oviedo, Spain
| | - Manuel M Esteban
- Departamento de Biología Funcional, Universidad de Oviedo, Oviedo, Spain
| | - Jose A Vega
- Departamento de Morfología y Biología Celular, Universidad de Oviedo, Oviedo, Spain.,Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Santiago, Chile
| | - Alvaro J Obaya
- Departamento de Biología Funcional, Universidad de Oviedo, Oviedo, Spain
| |
Collapse
|
19
|
Staels W, Verdonck Y, Heremans Y, Leuckx G, De Groef S, Heirman C, de Koning E, Gysemans C, Thielemans K, Baeyens L, Heimberg H, De Leu N. Vegf-A mRNA transfection as a novel approach to improve mouse and human islet graft revascularisation. Diabetologia 2018; 61:1804-1810. [PMID: 29789879 DOI: 10.1007/s00125-018-4646-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 04/23/2018] [Indexed: 12/28/2022]
Abstract
AIMS/HYPOTHESIS The initial avascular period following islet transplantation seriously compromises graft function and survival. Enhancing graft revascularisation to improve engraftment has been attempted through virus-based delivery of angiogenic triggers, but risks associated with viral vectors have hampered clinical translation. In vitro transcribed mRNA transfection circumvents these risks and may be used for improving islet engraftment. METHODS Mouse and human pancreatic islet cells were transfected with mRNA encoding the angiogenic growth factor vascular endothelial growth factor A (VEGF-A) before transplantation under the kidney capsule in mice. RESULTS At day 7 post transplantation, revascularisation of grafts transfected with Vegf-A (also known as Vegfa) mRNA was significantly higher compared with non-transfected or Gfp mRNA-transfected controls in mouse islet grafts (2.11- and 1.87-fold, respectively) (vessel area/graft area, mean ± SEM: 0.118 ± 0.01 [n = 3] in Vegf-A mRNA transfected group (VEGF) vs 0.056 ± 0.01 [n = 3] in no RNA [p < 0.05] vs 0.063 ± 0.02 [n = 4] in Gfp mRNA transfected group (GFP) [p < 0.05]); EndoC-bH3 grafts (2.85- and 2.48-fold. respectively) (0.085 ± 0.02 [n = 4] in VEGF vs 0.030 ± 0.004 [n = 4] in no RNA [p < 0.05] vs 0.034 ± 0.01 [n = 5] in GFP [p < 0.05]); and human islet grafts (3.17- and 3.80-fold, respectively) (0.048 ± 0.013 [n = 3] in VEGF vs 0.015 ± 0.0051 [n = 4] in no RNA [p < 0.01] vs 0.013 ± 0.0046 [n = 4] in GFP [p < 0.01]). At day 30 post transplantation, human islet grafts maintained a vascularisation benefit (1.70- and 1.82-fold, respectively) (0.049 ± 0.0042 [n = 8] in VEGF vs 0.029 ± 0.0052 [n = 5] in no RNA [p < 0.05] vs 0.027 ± 0.0056 [n = 4] in GFP [p < 0.05]) and a higher beta cell volume (1.64- and 2.26-fold, respectively) (0.0292 ± 0.0032 μl [n = 7] in VEGF vs 0.0178 ± 0.0021 μl [n = 5] in no RNA [p < 0.01] vs 0.0129 ± 0.0012 μl [n = 4] in GFP [p < 0.001]). CONCLUSIONS/INTERPRETATION Vegf-A mRNA transfection before transplantation provides a promising and safe strategy to improve engraftment of islets and other cell-based implants.
Collapse
Affiliation(s)
- Willem Staels
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium
- Department of Paediatrics, Division of Paediatric Endocrinology, Ghent University, Ghent, Belgium
| | - Yannick Verdonck
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium
| | - Yves Heremans
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium
| | - Gunter Leuckx
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium
| | - Sofie De Groef
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium
| | - Carlo Heirman
- Laboratory of Molecular and Cellular Therapy, Vrije Universiteit Brussel, Brussels, Belgium
| | - Eelco de Koning
- Department of Medicine, Section of Endocrinology, Leiden University Medical Center, Leiden, the Netherlands
| | - Conny Gysemans
- Laboratory of Clinical and Experimental Endocrinology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Kris Thielemans
- Laboratory of Molecular and Cellular Therapy, Vrije Universiteit Brussel, Brussels, Belgium
| | - Luc Baeyens
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium
| | - Harry Heimberg
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium.
| | - Nico De Leu
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium.
- Department of Endocrinology, UZ Brussel, Brussels, Belgium.
- Department of Endocrinology, ASZ Aalst, Aalst, Belgium.
| |
Collapse
|
20
|
Takahashi Y, Sekine K, Kin T, Takebe T, Taniguchi H. Self-Condensation Culture Enables Vascularization of Tissue Fragments for Efficient Therapeutic Transplantation. Cell Rep 2018; 23:1620-1629. [PMID: 29742420 PMCID: PMC8289710 DOI: 10.1016/j.celrep.2018.03.123] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 02/21/2018] [Accepted: 03/26/2018] [Indexed: 02/07/2023] Open
Abstract
Clinical transplantation of tissue fragments, including islets, faces a critical challenge because of a lack of effective strategies that ensure efficient engraftment through the timely integration of vascular networks. We recently developed a complex organoid engineering method by "self-condensation" culture based on mesenchymal cell-dependent contraction, thereby enabling dissociated heterotypic lineages including endothelial cells to self-organize in a spatiotemporal manner. Here, we report the successful adaptation of this method for generating complex tissues from diverse tissue fragments derived from various organs, including pancreatic islets. The self-condensation of human and mouse islets with endothelial cells not only promoted functionalization in culture but also massively improved post-transplant engraftment. Therapeutically, fulminant diabetic mice were more efficiently treated by a vascularized islet transplant compared with the conventional approach. Given the general limitations of post-transplant vascularization associated with 3D tissue-based therapy, our approach offers a promising means of enhancing efficacy in the context of therapeutic tissue transplantation.
Collapse
Affiliation(s)
- Yoshinobu Takahashi
- Department of Regenerative Medicine, Yokohama City University Graduate School of Medicine, Kanazawa-ku 3-9, Yokohama, Kanagawa 236-0004, Japan
| | - Keisuke Sekine
- Department of Regenerative Medicine, Yokohama City University Graduate School of Medicine, Kanazawa-ku 3-9, Yokohama, Kanagawa 236-0004, Japan
| | - Tatsuya Kin
- Clinical Islet Laboratory, University of Alberta, Edmonton, AB, Canada
| | - Takanori Takebe
- Department of Regenerative Medicine, Yokohama City University Graduate School of Medicine, Kanazawa-ku 3-9, Yokohama, Kanagawa 236-0004, Japan; Advanced Medical Research Center, Yokohama City University, Kanazawa-ku 3-9, Yokohama, Kanagawa 236-0004, Japan; Division of Gastroenterology, Hepatology & Nutrition, Developmental Biology, Center for Stem Cell and Organoid Medicine (CuSTOM), Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45229-3039, USA; Department of Pediatrics, University of Cincinnati College of Medicine, 3333 Burnet Avenue, Cincinnati, OH 45229-3039, USA; Institute of Research, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510, Japan.
| | - Hideki Taniguchi
- Department of Regenerative Medicine, Yokohama City University Graduate School of Medicine, Kanazawa-ku 3-9, Yokohama, Kanagawa 236-0004, Japan; Advanced Medical Research Center, Yokohama City University, Kanazawa-ku 3-9, Yokohama, Kanagawa 236-0004, Japan.
| |
Collapse
|
21
|
Staels W, Heremans Y, Leuckx G, Van Gassen N, Salinno C, De Groef S, Cools M, Keshet E, Dor Y, Heimberg H, De Leu N. Conditional islet hypovascularisation does not preclude beta cell expansion during pregnancy in mice. Diabetologia 2017; 60:1051-1056. [PMID: 28299380 DOI: 10.1007/s00125-017-4243-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 02/23/2017] [Indexed: 12/25/2022]
Abstract
AIMS/HYPOTHESIS Endothelial-endocrine cell interactions and vascular endothelial growth factor (VEGF)-A signalling are deemed essential for maternal islet vascularisation, glucose control and beta cell expansion during mouse pregnancy. The aim of this study was to assess whether pregnancy-associated beta cell expansion was affected under conditions of islet hypovascularisation. METHODS Soluble fms-like tyrosine kinase 1 (sFLT1), a VEGF-A decoy receptor, was conditionally overexpressed in maternal mouse beta cells from 1.5 to 14.5 days post coitum. Islet vascularisation, glycaemic control, beta cell proliferation, individual beta cell size and total beta cell volume were assessed in both pregnant mice and non-pregnant littermates. RESULTS Conditional overexpression of sFLT1 in beta cells resulted in islet hypovascularisation and glucose intolerance in both pregnant and non-pregnant mice. In contrast to non-pregnant littermates, glucose intolerance in pregnant mice was transient. sFLT1 overexpression did not affect pregnancy-associated changes in beta cell proliferation, individual beta cell size or total beta cell volume. CONCLUSIONS/INTERPRETATION Reduced intra-islet VEGF-A signalling results in maternal islet hypovascularisation and impaired glycaemic control but does not preclude beta cell expansion during mouse pregnancy.
Collapse
Affiliation(s)
- Willem Staels
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium
- Department of Paediatrics, Division of Paediatric Endocrinology, Ghent University Hospital and Ghent University, Ghent, Belgium
| | - Yves Heremans
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium
| | - Gunter Leuckx
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium
| | - Naomi Van Gassen
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium
| | - Ciro Salinno
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium
| | - Sofie De Groef
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium
| | - Martine Cools
- Department of Paediatrics, Division of Paediatric Endocrinology, Ghent University Hospital and Ghent University, Ghent, Belgium
| | - Eli Keshet
- Department of Developmental Biology and Cancer Research, Institute of Medical Research Israel-Canada, Hebrew University Hadassah Medical School, Jerusalem, Israel
| | - Yuval Dor
- Department of Developmental Biology and Cancer Research, Institute of Medical Research Israel-Canada, Hebrew University Hadassah Medical School, Jerusalem, Israel
| | - Harry Heimberg
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium.
| | - Nico De Leu
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium.
- Department of Endocrinology, Universitair Ziekenhuis Brussel, Brussels, Belgium.
- Department of Endocrinology, Algemeen Stedelijk Ziekenhuis Aalst, Aalst, Belgium.
| |
Collapse
|
22
|
Cunha JPMCM, Leuckx G, Sterkendries P, Korf H, Bomfim-Ferreira G, Overbergh L, Vaes B, Heimberg H, Gysemans C, Mathieu C. Human multipotent adult progenitor cells enhance islet function and revascularisation when co-transplanted as a composite pellet in a mouse model of diabetes. Diabetologia 2017; 60:134-142. [PMID: 27704164 PMCID: PMC6518081 DOI: 10.1007/s00125-016-4120-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 09/06/2016] [Indexed: 12/28/2022]
Abstract
AIMS/HYPOTHESIS Hypoxia in the initial days after islet transplantation leads to considerable loss of islet mass and contributes to disappointing outcomes in the clinical setting. The aim of the present study was to investigate whether co-transplantation of human non-endothelial bone marrow-derived multipotent adult progenitor cells (MAPCs), which are non-immunogenic and can secrete angiogenic growth factors during the initial days after implantation, could improve islet engraftment and survival. METHODS Islets (150) were co-transplanted, with or without human MAPCs (2.5 × 105) as separate or composite pellets, under the kidney capsule of syngeneic alloxan-induced diabetic C57BL/6 mice. Blood glucose levels were frequently monitored and IPGTTs were carried out. Grafts and serum were harvested at 2 and 5 weeks after transplantation to assess outcome. RESULTS Human MAPCs produced high amounts of angiogenic growth factors, including vascular endothelial growth factor, in vitro and in vivo, as demonstrated by the induction of neo-angiogenesis in the chorioallantoic membrane assay. Islet-human MAPC co-transplantation as a composite pellet significantly improved the outcome of islet transplantation as measured by the initial glycaemic control, diabetes reversal rate, glucose tolerance and serum C-peptide concentration compared with the outcome following transplantation of islets alone. Histologically, a higher blood vessel area and density in addition to a higher vessel/islet ratio were detected in recipients of islet-human MAPC composites. CONCLUSIONS/INTERPRETATION The present data suggest that co-transplantation of mouse pancreatic islets with human MAPCs, which secrete high amounts of angiogenic growth factors, enhance islet graft revascularisation and subsequently improve islet graft function.
Collapse
Affiliation(s)
- João Paulo M C M Cunha
- Laboratory of Clinical and Experimental Endocrinology, Katholieke Universiteit Leuven (KULEUVEN), Campus Gasthuisberg O&N1, Herestraat 49 bus 902, 3000, Leuven, Belgium
| | - Gunter Leuckx
- Beta cell neogenesis laboratory, Diabetes Research Center, Vrije Universiteit Brussel, Brussels, Belgium
| | | | - Hannelie Korf
- Laboratory of Clinical and Experimental Endocrinology, Katholieke Universiteit Leuven (KULEUVEN), Campus Gasthuisberg O&N1, Herestraat 49 bus 902, 3000, Leuven, Belgium
| | - Gabriela Bomfim-Ferreira
- Laboratory of Clinical and Experimental Endocrinology, Katholieke Universiteit Leuven (KULEUVEN), Campus Gasthuisberg O&N1, Herestraat 49 bus 902, 3000, Leuven, Belgium
| | - Lutgart Overbergh
- Laboratory of Clinical and Experimental Endocrinology, Katholieke Universiteit Leuven (KULEUVEN), Campus Gasthuisberg O&N1, Herestraat 49 bus 902, 3000, Leuven, Belgium
| | | | - Harry Heimberg
- Beta cell neogenesis laboratory, Diabetes Research Center, Vrije Universiteit Brussel, Brussels, Belgium
| | - Conny Gysemans
- Laboratory of Clinical and Experimental Endocrinology, Katholieke Universiteit Leuven (KULEUVEN), Campus Gasthuisberg O&N1, Herestraat 49 bus 902, 3000, Leuven, Belgium.
| | - Chantal Mathieu
- Laboratory of Clinical and Experimental Endocrinology, Katholieke Universiteit Leuven (KULEUVEN), Campus Gasthuisberg O&N1, Herestraat 49 bus 902, 3000, Leuven, Belgium
| |
Collapse
|
23
|
Langlois A, Dal S, Vivot K, Mura C, Seyfritz E, Bietiger W, Dollinger C, Peronet C, Maillard E, Pinget M, Jeandidier N, Sigrist S. Improvement of islet graft function using liraglutide is correlated with its anti-inflammatory properties. Br J Pharmacol 2016; 173:3443-3453. [PMID: 27515367 PMCID: PMC5120160 DOI: 10.1111/bph.13575] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 06/27/2016] [Accepted: 07/20/2016] [Indexed: 01/15/2023] Open
Abstract
Background and Purpose Liraglutide improves the metabolic control of diabetic animals after islet transplantation. However, the mechanisms underlying this effect remain unknown. The objective of this study was to evaluate the anti‐inflammatory and anti‐oxidative properties of liraglutide on rat pancreatic islets in vitro and in vivo. Experimental Approach In vitro, rat islets were incubated with 10 μmol·L−1 liraglutide for 12 and 24 h. Islet viability functionality was assessed. The anti‐inflammatory properties of liraglutide were evaluated by measuring CCL2, IL‐6 and IL‐10 secretion and macrophage chemotaxis. The anti‐oxidative effect of liraglutide was evaluated by measuring intracellular ROS and the total anti‐oxidative capacity. In vivo, 1000 islets were cultured for 24 h with or without liraglutide and then transplanted into the liver of streptozotocin‐induced diabetic Lewis rats with or without injections of liraglutide. Effects of liraglutide on metabolic control were evaluated for 1 month. Key Results Islet viability and function were preserved and enhanced with liraglutide treatment. Liraglutide decreased CCL2 and IL‐6 secretion and macrophage activation after 12 h of culture, while IL‐10 secretion was unchanged. However, intracellular levels of ROS were increased with liraglutide treatment at 12 h. This result was correlated with an increase of anti‐oxidative capacity. In vivo, liraglutide decreased macrophage infiltration and reduced fasting blood glucose in transplanted rats. Conclusions and Implications The beneficial effects of liraglutide on pancreatic islets appear to be linked to its anti‐inflammatory and anti‐oxidative properties. These findings indicated that analogues of glucagon‐like peptide‐1 could be used to improve graft survival.
Collapse
Affiliation(s)
- A Langlois
- UMR DIATHEC, EA 7294, Centre Européen d'Etude du Diabète, Université de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Strasbourg, France
| | - S Dal
- UMR DIATHEC, EA 7294, Centre Européen d'Etude du Diabète, Université de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Strasbourg, France
| | - K Vivot
- UMR DIATHEC, EA 7294, Centre Européen d'Etude du Diabète, Université de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Strasbourg, France
| | - C Mura
- UMR DIATHEC, EA 7294, Centre Européen d'Etude du Diabète, Université de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Strasbourg, France
| | - E Seyfritz
- UMR DIATHEC, EA 7294, Centre Européen d'Etude du Diabète, Université de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Strasbourg, France
| | - W Bietiger
- UMR DIATHEC, EA 7294, Centre Européen d'Etude du Diabète, Université de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Strasbourg, France
| | - C Dollinger
- UMR DIATHEC, EA 7294, Centre Européen d'Etude du Diabète, Université de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Strasbourg, France
| | - C Peronet
- UMR DIATHEC, EA 7294, Centre Européen d'Etude du Diabète, Université de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Strasbourg, France
| | - E Maillard
- UMR DIATHEC, EA 7294, Centre Européen d'Etude du Diabète, Université de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Strasbourg, France
| | - M Pinget
- UMR DIATHEC, EA 7294, Centre Européen d'Etude du Diabète, Université de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Strasbourg, France.,Service d'Endocrinologie, Diabète, Maladies Métaboliques, Pôle NUDE, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - N Jeandidier
- UMR DIATHEC, EA 7294, Centre Européen d'Etude du Diabète, Université de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Strasbourg, France.,Service d'Endocrinologie, Diabète, Maladies Métaboliques, Pôle NUDE, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - S Sigrist
- UMR DIATHEC, EA 7294, Centre Européen d'Etude du Diabète, Université de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Strasbourg, France
| |
Collapse
|
24
|
Tasev D, Koolwijk P, van Hinsbergh VWM. Therapeutic Potential of Human-Derived Endothelial Colony-Forming Cells in Animal Models. TISSUE ENGINEERING PART B-REVIEWS 2016; 22:371-382. [PMID: 27032435 DOI: 10.1089/ten.teb.2016.0050] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
PURPOSE OF REVIEW Tissue regeneration requires proper vascularization. In vivo studies identified that the endothelial colony-forming cells (ECFCs), a subtype of endothelial progenitor cells that can be isolated from umbilical cord or peripheral blood, represent a promising cell source for therapeutic neovascularization. ECFCs not only are able to initiate and facilitate neovascularization in diseased tissue but also can, by acting in a paracrine manner, contribute to the creation of favorable conditions for efficient and appropriate differentiation of tissue-resident stem or progenitor cells. This review outlines the progress in the field of in vivo regenerative and tissue engineering studies and surveys why, when, and how ECFCs can be used for tissue regeneration. RECENT FINDINGS Reviewed literature that regard human-derived ECFCs in xenogeneic animal models implicates that ECFCs should be considered as an endothelial cell source of preference for induction of neovascularization. Their neovascularization and regenerative potential is augmented in combination with other types of stem or progenitor cells. Biocompatible scaffolds prevascularized with ECFCs interconnect faster and better with the host vasculature. The physical incorporation of ECFCs in newly formed blood vessels grants prolonged release of trophic factors of interest, which also makes ECFCs an interesting cell source candidate for gene therapy and delivery of bioactive compounds in targeted area. SUMMARY ECFCs possess all biological features to be considered as a cell source of preference for tissue engineering and repair of blood supply. Investigation of regenerative potential of ECFCs in autologous settings in large animal models before clinical application is the next step to clearly outline the most efficient strategy for using ECFCs as treatment.
Collapse
Affiliation(s)
- Dimitar Tasev
- 1 Department of Physiology, Institute for Cardiovascular Research, VU University Medical Center Amsterdam , Amsterdam, The Netherlands .,2 A-Skin Nederland BV , Amsterdam, The Netherlands
| | - Pieter Koolwijk
- 1 Department of Physiology, Institute for Cardiovascular Research, VU University Medical Center Amsterdam , Amsterdam, The Netherlands
| | - Victor W M van Hinsbergh
- 1 Department of Physiology, Institute for Cardiovascular Research, VU University Medical Center Amsterdam , Amsterdam, The Netherlands
| |
Collapse
|
25
|
Xiao X, Fischbach S, Song Z, Gaffar I, Zimmerman R, Wiersch J, Prasadan K, Shiota C, Guo P, Ramachandran S, Witkowski P, Gittes GK. Transient Suppression of TGFβ Receptor Signaling Facilitates Human Islet Transplantation. Endocrinology 2016; 157:1348-56. [PMID: 26872091 PMCID: PMC4816736 DOI: 10.1210/en.2015-1986] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Although islet transplantation is an effective treatment for severe diabetes, its broad application is greatly limited due to a shortage of donor islets. Suppression of TGFβ receptor signaling in β-cells has been shown to increase β-cell proliferation in mice, but has not been rigorously examined in humans. Here, treatment of human islets with a TGFβ receptor I inhibitor, SB-431542 (SB), significantly improved C-peptide secretion by β-cells, and significantly increased β-cell number by increasing β-cell proliferation. In addition, SB increased cell-cycle activators and decreased cell-cycle suppressors in human β-cells. Transplantation of SB-treated human islets into diabetic immune-deficient mice resulted in significant improvement in blood glucose control, significantly higher serum and graft insulin content, and significantly greater increases in β-cell proliferation in the graft, compared with controls. Thus, our data suggest that transient suppression of TGFβ receptor signaling may improve the outcome of human islet transplantation, seemingly through increasing β-cell number and function.
Collapse
|
26
|
Langlois A, Mura C, Bietiger W, Seyfritz E, Dollinger C, Peronet C, Maillard E, Pinget M, Jeandidier N, Sigrist S. In Vitro and In Vivo Investigation of the Angiogenic Effects of Liraglutide during Islet Transplantation. PLoS One 2016; 11:e0147068. [PMID: 26974949 PMCID: PMC4790919 DOI: 10.1371/journal.pone.0147068] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 12/27/2015] [Indexed: 11/19/2022] Open
Abstract
INTRODUCTION This study investigated the angiogenic properties of liraglutide in vitro and in vivo and the mechanisms involved, with a focus on Hypoxia Inducible Factor-1α (HIF-1α) and mammalian target of rapamycin (mTOR). MATERIALS AND METHODS Rat pancreatic islets were incubated in vitro with 10 μmol/L of liraglutide (Lira) for 12, 24 and 48 h. Islet viability was studied by fluorescein diacetate/propidium iodide staining and their function was assessed by glucose stimulation. The angiogenic effect of liraglutide was determined in vitro by the measure of vascular endothelial growth factor (VEGF) secretion using enzyme-linked immunosorbent assay and by the evaluation of VEGF and platelet-derived growth factor-α (PDGFα) expression with quantitative polymerase chain reaction technic. Then, in vitro and in vivo, angiogenic property of Lira was evaluated using immunofluorescence staining targeting the cluster of differentiation 31 (CD31). To understand angiogenic mechanisms involved by Lira, HIF-1α and mTOR activation were studied using western blotting. In vivo, islets (1000/kg body-weight) were transplanted into diabetic (streptozotocin) Lewis rats. Metabolic control was assessed for 1 month by measuring body-weight gain and fasting blood glucose. RESULTS Islet viability and function were respectively preserved and enhanced (p<0.05) with Lira, versus control. Lira increased CD31-positive cells, expression of VEGF and PDGFα (p<0.05) after 24 h in culture. Increased VEGF secretion versus control was also observed at 48 h (p<0.05). Moreover, Lira activated mTOR (p<0.05) signalling pathway. In vivo, Lira improved vascular density (p<0.01), body-weight gain (p<0.01) and reduced fasting blood glucose in transplanted rats (p<0.001). CONCLUSION The beneficial effects of liraglutide on islets appeared to be linked to its angiogenic properties. These findings indicated that glucagon-like peptide-1 analogues could be used to improve transplanted islet revascularisation.
Collapse
Affiliation(s)
- Allan Langlois
- UMR DIATHEC, EA 7294, Centre Européen d’Etude du Diabète, Université de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Bld René Leriche, 67200 Strasbourg, France
| | - Carole Mura
- UMR DIATHEC, EA 7294, Centre Européen d’Etude du Diabète, Université de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Bld René Leriche, 67200 Strasbourg, France
| | - William Bietiger
- UMR DIATHEC, EA 7294, Centre Européen d’Etude du Diabète, Université de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Bld René Leriche, 67200 Strasbourg, France
| | - Elodie Seyfritz
- UMR DIATHEC, EA 7294, Centre Européen d’Etude du Diabète, Université de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Bld René Leriche, 67200 Strasbourg, France
| | - Camille Dollinger
- UMR DIATHEC, EA 7294, Centre Européen d’Etude du Diabète, Université de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Bld René Leriche, 67200 Strasbourg, France
| | - Claude Peronet
- UMR DIATHEC, EA 7294, Centre Européen d’Etude du Diabète, Université de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Bld René Leriche, 67200 Strasbourg, France
| | - Elisa Maillard
- UMR DIATHEC, EA 7294, Centre Européen d’Etude du Diabète, Université de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Bld René Leriche, 67200 Strasbourg, France
| | - Michel Pinget
- UMR DIATHEC, EA 7294, Centre Européen d’Etude du Diabète, Université de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Bld René Leriche, 67200 Strasbourg, France
- Service d’Endocrinologie, Diabète, Maladies Métaboliques, Pôle NUDE, Hôpitaux Universitaires de Strasbourg, 67000 Strasbourg, France
| | - Nathalie Jeandidier
- UMR DIATHEC, EA 7294, Centre Européen d’Etude du Diabète, Université de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Bld René Leriche, 67200 Strasbourg, France
- Service d’Endocrinologie, Diabète, Maladies Métaboliques, Pôle NUDE, Hôpitaux Universitaires de Strasbourg, 67000 Strasbourg, France
| | - Séverine Sigrist
- UMR DIATHEC, EA 7294, Centre Européen d’Etude du Diabète, Université de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Bld René Leriche, 67200 Strasbourg, France
| |
Collapse
|
27
|
Staels W, De Groef S, Heremans Y, Coppens V, Van Gassen N, Leuckx G, Van de Casteele M, Van Riet I, Luttun A, Heimberg H, De Leu N. Accessory cells for β-cell transplantation. Diabetes Obes Metab 2016; 18:115-24. [PMID: 26289770 DOI: 10.1111/dom.12556] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 07/22/2015] [Accepted: 08/13/2015] [Indexed: 12/16/2022]
Abstract
Despite recent advances, insulin therapy remains a treatment, not a cure, for diabetes mellitus with persistent risk of glycaemic alterations and life-threatening complications. Restoration of the endogenous β-cell mass through regeneration or transplantation offers an attractive alternative. Unfortunately, signals that drive β-cell regeneration remain enigmatic and β-cell replacement therapy still faces major hurdles that prevent its widespread application. Co-transplantation of accessory non-islet cells with islet cells has been shown to improve the outcome of experimental islet transplantation. This review will highlight current travails in β-cell therapy and focuses on the potential benefits of accessory cells for islet transplantation in diabetes.
Collapse
MESH Headings
- Animals
- Cell Proliferation
- Cell Separation/trends
- Cells, Cultured
- Diabetes Mellitus, Type 1/immunology
- Diabetes Mellitus, Type 1/metabolism
- Diabetes Mellitus, Type 1/pathology
- Diabetes Mellitus, Type 1/surgery
- Diabetes Mellitus, Type 2/immunology
- Diabetes Mellitus, Type 2/metabolism
- Diabetes Mellitus, Type 2/pathology
- Diabetes Mellitus, Type 2/surgery
- Endothelial Progenitor Cells/cytology
- Endothelial Progenitor Cells/immunology
- Endothelial Progenitor Cells/pathology
- Endothelial Progenitor Cells/transplantation
- Graft Rejection/immunology
- Graft Rejection/metabolism
- Graft Rejection/prevention & control
- Graft Survival
- Humans
- Immune Tolerance
- Insulin-Secreting Cells/cytology
- Insulin-Secreting Cells/immunology
- Insulin-Secreting Cells/metabolism
- Insulin-Secreting Cells/transplantation
- Islets of Langerhans Transplantation/adverse effects
- Islets of Langerhans Transplantation/immunology
- Mesenchymal Stem Cell Transplantation/adverse effects
- Mesenchymal Stem Cell Transplantation/trends
- Neural Crest/cytology
- Neural Crest/immunology
- Neural Crest/pathology
- Neural Crest/transplantation
- Stem Cell Transplantation/adverse effects
- Stem Cell Transplantation/trends
- T-Lymphocytes, Regulatory/cytology
- T-Lymphocytes, Regulatory/immunology
- T-Lymphocytes, Regulatory/pathology
- T-Lymphocytes, Regulatory/transplantation
- Transplantation, Autologous/adverse effects
- Transplantation, Autologous/trends
- Transplantation, Heterotopic/adverse effects
- Transplantation, Heterotopic/trends
- Transplantation, Homologous/adverse effects
- Transplantation, Homologous/trends
Collapse
Affiliation(s)
- W Staels
- Diabetes Research Center, Vrije Universiteit Brussel, Brussels, Belgium
- Division of Pediatric Endocrinology, Department of Pediatrics, Ghent University Hospital, Ghent, Belgium
- Department of Pediatrics and Genetics, Ghent University, Ghent, Belgium
| | - S De Groef
- Diabetes Research Center, Vrije Universiteit Brussel, Brussels, Belgium
| | - Y Heremans
- Diabetes Research Center, Vrije Universiteit Brussel, Brussels, Belgium
| | - V Coppens
- Diabetes Research Center, Vrije Universiteit Brussel, Brussels, Belgium
| | - N Van Gassen
- Diabetes Research Center, Vrije Universiteit Brussel, Brussels, Belgium
| | - G Leuckx
- Diabetes Research Center, Vrije Universiteit Brussel, Brussels, Belgium
| | - M Van de Casteele
- Diabetes Research Center, Vrije Universiteit Brussel, Brussels, Belgium
| | - I Van Riet
- Department Hematology Immunology, Vrije Universiteit Brussel, Brussels, Belgium
| | - A Luttun
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, KU Leuven, Leuven, Belgium
| | - H Heimberg
- Diabetes Research Center, Vrije Universiteit Brussel, Brussels, Belgium
| | - N De Leu
- Diabetes Research Center, Vrije Universiteit Brussel, Brussels, Belgium
- Department of Endocrinology, UZ Brussel, Brussels, Belgium
- Department of Endocrinology, ASZ Aalst, Aalst, Belgium
| |
Collapse
|
28
|
Quaranta P, Antonini S, Spiga S, Mazzanti B, Curcio M, Mulas G, Diana M, Marzola P, Mosca F, Longoni B. Co-transplantation of endothelial progenitor cells and pancreatic islets to induce long-lasting normoglycemia in streptozotocin-treated diabetic rats. PLoS One 2014; 9:e94783. [PMID: 24733186 PMCID: PMC3986409 DOI: 10.1371/journal.pone.0094783] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 03/20/2014] [Indexed: 01/09/2023] Open
Abstract
Graft vascularization is a crucial step to obtain stable normoglycemia in pancreatic islet transplantation. Endothelial progenitor cells (EPCs) contribute to neoangiogenesis and to the revascularization process during ischaemic events and play a key role in the response to pancreatic islet injury. In this work we co-transplanted EPCs and islets in the portal vein of chemically-induced diabetic rats to restore islet vascularization and to improve graft survival. Syngenic islets were transplanted, either alone or with EPCs derived from green fluorescent protein (GFP) transgenic rats, into the portal vein of streptozotocin-induced diabetic rats. Blood glucose levels were monitored and intraperitoneal glucose tolerance tests were performed. Real time-PCR was carried out to evaluate the gene expression of angiogenic factors. Diabetic-induced rats showed long-lasting (6 months) normoglycemia upon co-transplantation of syngenic islets and EPCs. After 3–5 days from transplantation, hyperglycaemic levels dropped to normal values and lasted unmodified as long as they were checked. Further, glucose tolerance tests revealed the animals' ability to produce insulin on-demand as indexed by a prompt response in blood glucose clearance. Graft neovascularization was evaluated by immunohistochemistry: for the first time the measure of endothelial thickness revealed a donor-EPC-related neovascularization supporting viable islets up to six months after transplant. Our results highlight the importance of a newly formed viable vascular network together with pancreatic islets to provide de novo adequate supply in order to obtain enduring normoglycemia and prevent diabetes-related long-term health hazards.
Collapse
Affiliation(s)
- Paola Quaranta
- Department of Translational Research and New Technology in Medicine, University of Pisa, Pisa, Italy
| | - Sara Antonini
- Department of Translational Research and New Technology in Medicine, University of Pisa, Pisa, Italy
| | - Saturnino Spiga
- Department of Life and Environmental Sciences, University of Cagliari, Cagliari, Italy
| | - Benedetta Mazzanti
- Department of Clinical and Experimental Medicine, Haematology Section, University of Florence, Florence, Italy
| | - Michele Curcio
- U.O. Immunohaematology, Azienda Ospedaliera-Universitaria Pisana, Pisa, Italy
| | - Giovanna Mulas
- Department of Life and Environmental Sciences, University of Cagliari, Cagliari, Italy
| | - Marco Diana
- Department of Chemistry and Pharmacy, “G. Minardi” Laboratory of Cognitive Neuroscience, University of Sassari, Sassari, Italy
| | - Pasquina Marzola
- Department of Computer Science, University of Verona, Verona, Italy
| | - Franco Mosca
- Department of Translational Research and New Technology in Medicine, University of Pisa, Pisa, Italy
| | - Biancamaria Longoni
- Department of Translational Research and New Technology in Medicine, University of Pisa, Pisa, Italy
- * E-mail:
| |
Collapse
|
29
|
Coppens V, Heremans Y, Leuckx G, Suenens K, Jacobs-Tulleneers-Thevissen D, Verdonck K, Luttun A, Heimberg H, De Leu N. Reversal of hyperglycemia in diabetic mice by a marginal islet mass together with human blood outgrowth endothelial cells is independent of the delivery technique and blood clot-induced processes. Islets 2013; 5:196-200. [PMID: 24213480 PMCID: PMC4010571 DOI: 10.4161/isl.26778] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
We recently reported that human blood outgrowth endothelial cells (BOEC) are supportive to reverse hyperglycemia in marginal islet mass-transplanted diabetic mice. In this report, we investigated whether the observed effect was evoked by islet packing in a blood clot prior to transplantation or could be mimicked by another method of islet/cell delivery. A marginal islet mass with or without BOEC was grafted underneath the kidney capsule of diabetic recipient mice via a (blood clot-independent) tubing system and compared with previous islet packing in a blood clot. The effect on metabolic outcome of both delivery techniques as well as the additive effect of BOEC was subsequently evaluated. Marginal islet mass transplantation via a tubing system required more islets per recipient than via a blood clot. Using the tubing method, transplantation of a marginal islet mass combined with 5x10 (5) BOEC resulted in reversal of hyperglycemia, improved glucose tolerance and increased kidney insulin content. The present study provides evidence that (1) previous packing in a blood clot results in more effective islet delivery compared with tubing; (2) BOEC exert a beneficial effect on marginal islet transplantation, independent of grafting technique and potential blood clot-induced processes. These data further support the use of BOEC in (pre-) clinical studies that aim to improve current islet transplantation protocols.
Collapse
Affiliation(s)
- Violette Coppens
- Diabetes Research Center; Vrije Universiteit Brussel; Brussels, Belgium
| | - Yves Heremans
- Diabetes Research Center; Vrije Universiteit Brussel; Brussels, Belgium
| | - Gunter Leuckx
- Diabetes Research Center; Vrije Universiteit Brussel; Brussels, Belgium
| | - Krista Suenens
- Diabetes Research Center; Vrije Universiteit Brussel; Brussels, Belgium
| | | | - Kristoff Verdonck
- Department of Cardiovascular Sciences; Center for Molecular and Vascular Biology; KU Leuven; Leuven, Belgium
| | - Aernout Luttun
- Department of Cardiovascular Sciences; Center for Molecular and Vascular Biology; KU Leuven; Leuven, Belgium
| | - Harry Heimberg
- Diabetes Research Center; Vrije Universiteit Brussel; Brussels, Belgium
| | - Nico De Leu
- Diabetes Research Center; Vrije Universiteit Brussel; Brussels, Belgium
- Correspondence to: Nico De Leu,
| |
Collapse
|
30
|
Transplantation of pancreatic islets to adrenal gland is promoted by agonists of growth-hormone-releasing hormone. Proc Natl Acad Sci U S A 2013; 110:2288-93. [PMID: 23345449 DOI: 10.1073/pnas.1221505110] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Here, we evaluate an alternative approach of preconditioning pancreatic islets before transplantation using a potent agonist of growth-hormone-releasing hormone (GHRH) to promote islet viability and function, and we explore the adrenal gland as an alternative transplantation site for islet engraftment. The endocrine microenvironment of the adrenal represents a promising niche with the unique advantages of exceptional high oxygen tension and local anti-inflammatory and immunosuppressive properties. GHRH agonists have been shown to promote islet graft survival and function, which may help to reduce the islet mass necessary to reverse diabetes. In the present study, the most potent GHRH agonist MR403 was tested on insulinoma cells, isolated rat islets, and adrenal β-cell cocultures in vitro. GHRH receptor is expressed on both adrenal cells and islets. MR403 caused a significant increase in cell viability and proliferation and revealed an antiapoptotic effect on insulinoma cells. Viability of rat islets was increased after treatment with the agonist and in coculture with adrenal cells. Rat islets were transplanted into diabetic mice to the intraadrenal transplant site and compared with the classical transplants underneath the kidney capsule. Graft function and integration were tested by metabolic follow-up and immunohistochemical staining of intraadrenal grafts. A rapid decrease occurred in blood glucose levels in both models, and all animals reached normoglycemia within the first days after transplantation. Our studies demonstrated that the adrenal may be an attractive site for islet transplantation and that GHRH analogs might allow reduction of the islet mass needed to reverse a diabetic status.
Collapse
|