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Nashimoto Y, Shishido S, Onuma K, Ino K, Inoue M, Shiku H. Oxygen metabolism analysis of a single organoid for non-invasive discrimination of cancer subpopulations with different growth capabilities. Front Bioeng Biotechnol 2023; 11:1184325. [PMID: 37274161 PMCID: PMC10232988 DOI: 10.3389/fbioe.2023.1184325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Accepted: 05/08/2023] [Indexed: 06/06/2023] Open
Abstract
Heterogeneous nature is a pivotal aspect of cancer, rendering treatment problematic and frequently resulting in recurrence. Therefore, advanced techniques for identifying subpopulations of a tumour in an intact state are essential to develop novel screening platforms that can reveal differences in treatment response among subpopulations. Herein, we conducted a non-invasive analysis of oxygen metabolism on multiple subpopulations of patient-derived organoids, examining its potential utility for non-destructive identification of subpopulations. We utilised scanning electrochemical microscopy (SECM) for non-invasive analysis of oxygen metabolism. As models of tumours with heterogeneous subpopulations, we used patient-derived cancer organoids with a distinct growth potential established using the cancer tissue-originated spheroid methodology. Scanning electrochemical microscopy measurements enabled the analysis of the oxygen consumption rate (OCR) for individual organoids as small as 100 µm in diameter and could detect the heterogeneity amongst studied subpopulations, which was not observed in conventional colorectal cancer cell lines. Furthermore, our oxygen metabolism analysis of pre-isolated subpopulations with a slow growth potential revealed that oxygen consumption rate may reflect differences in the growth rate of organoids. Although the proposed technique currently lacks single-cell level sensitivity, the variability of oxygen metabolism across tumour subpopulations is expected to serve as an important indicator for the discrimination of tumour subpopulations and construction of novel drug screening platforms in the future.
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Affiliation(s)
- Yuji Nashimoto
- Institute of Bioengineering and Biomaterials (IBB), Tokyo Medical and Dental University (TMDU), Tokyo, Japan
- Frontier Research Institute for Interdisciplinary Sciences (FRIS), Tohoku University, Sendai, Miyagi, Japan
- Graduate School of Environmental Studies, Tohoku University, Sendai, Miyagi, Japan
- Graduate School of Engineering, Tohoku University, Sendai, Miyagi, Japan
| | - Shotaro Shishido
- Graduate School of Environmental Studies, Tohoku University, Sendai, Miyagi, Japan
| | | | - Kosuke Ino
- Graduate School of Engineering, Tohoku University, Sendai, Miyagi, Japan
| | - Masahiro Inoue
- Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Hitoshi Shiku
- Graduate School of Environmental Studies, Tohoku University, Sendai, Miyagi, Japan
- Graduate School of Engineering, Tohoku University, Sendai, Miyagi, Japan
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Fathi I, Nishimura R, Imura T, Inagaki A, Kanai N, Ushiyama A, Kikuchi M, Maekawa M, Yamaguchi H, Goto M. KRP-203 Is a Desirable Immunomodulator for Islet Allotransplantation. Transplantation 2022; 106:963-972. [PMID: 34241985 PMCID: PMC9038237 DOI: 10.1097/tp.0000000000003870] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 06/04/2021] [Accepted: 06/06/2021] [Indexed: 11/26/2022]
Abstract
BACKGROUND The current standard immunosuppressive regimens, calcineurin inhibitors, have diabetogenic and anti-vascularization effects on islet grafts. KRP-203, a sphingosine-1-phosphate functional antagonist, exerts its immunomodulatory function through lymphocyte sequestration. However, the effect of this antagonist on islets is unclear. We examined the effect of KRP-203 on the islet function and vascularization and sought a calcineurin-free regimen for islet allotransplantation. METHODS KRP-203 was administered for 14 d to mice, then diabetogenic effect was evaluated by blood glucose levels and a glucose tolerance test. Static glucose stimulation, the breathing index, and insulin/DNA were examined using isolated islets. Islet neovascularization was evaluated using a multiphoton laser scanning microscope. After islet allotransplantation with either KRP-203 alone, sirolimus alone, or both in combination, the graft survival was evaluated by blood glucose levels and immunohistochemical analyses. A mixed lymphocyte reaction was also performed to investigate the immunologic characteristics of KRP-203 and sirolimus. RESULTS No significant differences in the blood glucose levels or glucose tolerance were observed between the control and KRP-203 groups. Functional assays after islet isolation were also comparable. The multiphoton laser scanning microscope showed no inhibitory effect of KRP-203 on islet neovascularization. Although allogeneic rejection was effectively inhibited by KRP-203 monotherapy (44%), combination therapy prevented rejection in most transplanted mice (83%). CONCLUSIONS KRP-203 is a desirable immunomodulator for islet transplantation because of the preservation of the endocrine function and lack of interference with islet neovascularization. The combination of KRP-203 with low-dose sirolimus may be promising as a calcineurin-free regimen for islet allotransplantation.
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Affiliation(s)
- Ibrahim Fathi
- Division of Transplantation and Regenerative Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
- Department of Surgery, University of Alexandria, Alexandria, Egypt
| | - Ryuichi Nishimura
- Department of Surgery, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Takehiro Imura
- Division of Transplantation and Regenerative Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Akiko Inagaki
- Division of Transplantation and Regenerative Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Norifumi Kanai
- Department of Surgery, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Akira Ushiyama
- Department of Environmental Health, National Institute of Public Health, Wako, Japan
| | - Masafumi Kikuchi
- Department of Pharmaceutical Science, Tohoku University Hospital, Sendai, Japan
| | - Masamitsu Maekawa
- Department of Pharmaceutical Science, Tohoku University Hospital, Sendai, Japan
| | - Hiroaki Yamaguchi
- Department of Pharmacy, Yamagata University Graduate School of Medical Science, Yamagata University Hospital, Yamagata, Japan
| | - Masafumi Goto
- Division of Transplantation and Regenerative Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
- Department of Surgery, Tohoku University Graduate School of Medicine, Sendai, Japan
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Matsumura M, Imura T, Inagaki A, Ogasawara H, Fukuoka K, Fathi I, Miyagi S, Ohashi K, Unno M, Kamei T, Satomi S, Goto M. A Simple and Useful Predictive Assay for Evaluating the Quality of Isolated Hepatocytes for Hepatocyte Transplantation. Sci Rep 2019; 9:6166. [PMID: 30992529 PMCID: PMC6467914 DOI: 10.1038/s41598-019-42720-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 04/08/2019] [Indexed: 12/13/2022] Open
Abstract
No optimal assay for assessing isolated hepatocytes before hepatocyte transplantation (HTx) has been established, therefore reliable and rapid assays are warranted. Isolated rat hepatocytes were dipped in a water bath (necrosis model), and were also cultured with Okadaic acid (apoptosis model) or vehicle, followed by cellular assessment including trypan blue exclusion (TBE) viability, ADP /ATP ratio, plating efficiency (PE), DNA quantity and ammonia elimination. Hepatocytes were transplanted into the liver of analbuminemic rats, subsequently engraftment was assessed by serum albumin and the histology of transplanted grafts. In the necrosis model, the ADP/ATP ratio was strongly and negatively correlated with the TBE (R2 = 0.559, P < 0.001). In the apoptosis model, the ADP/ATP ratio assay, PE, DNA quantification and an ammonia elimination test clearly distinguished the groups (P < 0.001, respectively). The ADP/ATP ratio, PE and DNA quantity were well-correlated and the ammonia elimination was slightly correlated with the transplant outcome. TBE could not distinguish the groups and was not correlated with the outcome. The ADP/ATP ratio assay predicted the transplant outcome. PE and DNA quantification may improve the accuracy of the retrospective (evaluations require several days) quality assessment of hepatocytes. The ADP/ATP ratio assay, alone or with a short-term metabolic assay could improve the efficiency of HTx.
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Affiliation(s)
- Muneyuki Matsumura
- Department of Surgery, Tohoku University Graduate School of Medicine, 980-0872, Sendai, Japan
| | - Takehiro Imura
- Division of Transplantation and Regenerative Medicine, Tohoku University School of Medicine, 980-0872, Sendai, Japan
| | - Akiko Inagaki
- Division of Transplantation and Regenerative Medicine, Tohoku University School of Medicine, 980-0872, Sendai, Japan
| | - Hiroyuki Ogasawara
- Department of Surgery, Tohoku University Graduate School of Medicine, 980-0872, Sendai, Japan
| | - Kengo Fukuoka
- Department of Surgery, Tohoku University Graduate School of Medicine, 980-0872, Sendai, Japan
| | - Ibrahim Fathi
- Division of Transplantation and Regenerative Medicine, Tohoku University School of Medicine, 980-0872, Sendai, Japan
| | - Shigehito Miyagi
- Department of Surgery, Tohoku University Graduate School of Medicine, 980-0872, Sendai, Japan
| | - Kazuo Ohashi
- Graduate School of Pharmaceutical Sciences, Osaka University, 565-0871, Osaka, Japan
| | - Michiaki Unno
- Department of Surgery, Tohoku University Graduate School of Medicine, 980-0872, Sendai, Japan
| | - Takashi Kamei
- Department of Surgery, Tohoku University Graduate School of Medicine, 980-0872, Sendai, Japan
| | - Susumu Satomi
- Department of Surgery, Tohoku University Graduate School of Medicine, 980-0872, Sendai, Japan
| | - Masafumi Goto
- Department of Surgery, Tohoku University Graduate School of Medicine, 980-0872, Sendai, Japan. .,Division of Transplantation and Regenerative Medicine, Tohoku University School of Medicine, 980-0872, Sendai, Japan.
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Hiramoto K, Yasumi M, Ushio H, Shunori A, Ino K, Shiku H, Matsue T. Development of Oxygen Consumption Analysis with an on-Chip Electrochemical Device and Simulation. Anal Chem 2017; 89:10303-10310. [DOI: 10.1021/acs.analchem.7b02074] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Kaoru Hiramoto
- Corporate
Engineering Division, Automotive and Industrial Systems Company, Panasonic Corporation, 1006 Kadoma, Kadomashi, 571-0050, Japan
| | - Masahiro Yasumi
- Corporate
Engineering Division, Automotive and Industrial Systems Company, Panasonic Corporation, 1006 Kadoma, Kadomashi, 571-0050, Japan
| | - Hiroshi Ushio
- Corporate
Engineering Division, Automotive and Industrial Systems Company, Panasonic Corporation, 1006 Kadoma, Kadomashi, 571-0050, Japan
| | - Atsushi Shunori
- Corporate
Engineering Division, Automotive and Industrial Systems Company, Panasonic Corporation, 1006 Kadoma, Kadomashi, 571-0050, Japan
| | - Kosuke Ino
- Graduate
School of Engineering, Tohoku University, 6-6-11-406 Aramaki-aza Aoba, Aoba-ku, Sendai 980-8579, Japan
| | - Hitoshi Shiku
- Graduate
School of Engineering, Tohoku University, 6-6-11-406 Aramaki-aza Aoba, Aoba-ku, Sendai 980-8579, Japan
| | - Tomokazu Matsue
- Graduate School of Environmental Studies, Tohoku University, 6-6-11-605
Aramaki-aza Aoba, Aoba-ku, Sendai, 980-8579, Japan
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The Optimization of Short-Term Hepatocyte Preservation Before Transplantation. Transplant Direct 2017; 3:e176. [PMID: 28706979 PMCID: PMC5498017 DOI: 10.1097/txd.0000000000000687] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 04/10/2017] [Indexed: 01/15/2023] Open
Abstract
Background No optimal methods for short-term hepatocyte preservation have been established. We have recently developed a prominent oxygen-permeable bag (Tohoku Device [TD]) for pancreatic islet culture and transplantation. In this study, we investigated whether TD is also effective for hepatocyte preservation and tried to optimize other conditions. Methods Hepatocytes were preserved in the following conditions, and their outcomes were observed. First, the effectiveness of TD was investigated. Second, hepatocyte medium (HM) and organ preservation solutions with or without fetal bovine serum (FBS) were compared. Third, as supplementations, FBS and human serum albumin (HSA) were compared. Fourth, low, room and high temperature were compared. And finally, hepatocytes preserved in various conditions were transplanted into the subrenal capsule space of nonalbumin rats and engrafted areas were assessed. Results The survival rate of hepatocytes preserved in TD tended to be higher and their viability and function were maintained significantly greater than those of non-TD group. Irrespective of FBS supplementation, the survival rate of HM group was significantly higher than those of organ preservation solution group while viabilities and plating efficiency were similar among them. Although survival rates of groups without FBS were extremely low, results of HSA supplemented group were not inferior to FBS supplemented group. Hepatocytes preserved at high temperature had the worst results. The engrafted area of TD group tended to be higher than those of other groups. Conclusions TD is effective for short-term hepatocyte preservation. HSA is a useful substitute for FBS, and preserving in HM at low temperature is recommended.
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Electrochemical evidence for asialoglycoprotein receptor – mediated hepatocyte adhesion and proliferation in three dimensional tissue engineering scaffolds. Anal Chim Acta 2015; 890:83-90. [DOI: 10.1016/j.aca.2015.06.057] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 04/30/2015] [Accepted: 06/30/2015] [Indexed: 11/18/2022]
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Re-engineering islet cell transplantation. Pharmacol Res 2015; 98:76-85. [PMID: 25814189 DOI: 10.1016/j.phrs.2015.02.010] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 02/23/2015] [Accepted: 02/23/2015] [Indexed: 12/12/2022]
Abstract
We are living exciting times in the field of beta cell replacement therapies for the treatment of diabetes. While steady progress has been recorded thus far in clinical islet transplantation, novel approaches are needed to make cell-based therapies more reproducible and leading to long-lasting success. The multiple facets of diabetes impose the need for a transdisciplinary approach to attain this goal, by targeting immunity, promoting engraftment and sustained functional potency. We discuss herein the emerging technologies applied to this rapidly evolving field.
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Shiku H, Arai T, Zhou Y, Aoki N, Nishijo T, Horiguchi Y, Ino K, Matsue T. Noninvasive measurement of respiratory activity of mouse embryoid bodies and its correlation with mRNA levels of undifferentiation/differentiation markers. MOLECULAR BIOSYSTEMS 2013; 9:2701-11. [DOI: 10.1039/c3mb70223e] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Ductal injection does not increase the islet yield or function after cold storage in a vascular perfusion model. PLoS One 2012; 7:e42319. [PMID: 22900012 PMCID: PMC3416830 DOI: 10.1371/journal.pone.0042319] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Accepted: 07/03/2012] [Indexed: 11/19/2022] Open
Abstract
Several studies have reported that pancreatic ductal preservation greatly improved the islet yield and function after cold storage. However, these studies were devoid of appropriate controls, such as vascular perfusion, which is routinely performed to preserve organs in the clinical setting. In this study, we created a vascular perfusion model using inbred rats, and investigated the effect of ductal injection on the islet yield and function after cold storage. Rat pancreases after 10 h cold ischemia were classified as follows: without ductal/vascular perfusion; with ductal injection; with vascular perfusion; and with ductal/vascular perfusion. The islet yield, function, viability, release of inflammatory mediators, and pathological changes in the exocrine tissues were assessed in the Hanks' Balanced Salt Solution (HBSS) model. The islet yield was also assesed by introducing University of Wisconsin Solution (UWS) and Histidine-Tryptophan-Ketoglutarate solution (HTK), which are the standard clinical preservation solutions. In the HBSS model, ductal injection and vascular perfusion significantly improved the islet yield compared with the control group. However, ductal injection showed no additional effects on the islet yield, function, viability and suppressing the release of inflammatory mediators when vascular perfusion was performed. Although ductal injection significantly decreased the apoptosis of exocrine cells, no beneficial effect on vacuolation was observed. In contrast, vascular perfusion significantly suppressed vacuolation in the exocrine tissues. Likewise, in the UWS and HTK model, ductal injection and vascular perfusion improved the islet yield compared with the control group. Nevertheless, the combination group showed no additional effects. These data suggest that ductal injection has no additional effect on islet yield and function after cold storage in a vascular perfusion model. We propose that ductal injection can be an effective and simple alternative for vascular perfusion prior to pancreas harvest, but is not necessary in most cases, since vascular perfusion is routinely performed.
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Buchwald P. A local glucose-and oxygen concentration-based insulin secretion model for pancreatic islets. Theor Biol Med Model 2011; 8:20. [PMID: 21693022 PMCID: PMC3138450 DOI: 10.1186/1742-4682-8-20] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2011] [Accepted: 06/21/2011] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Because insulin is the main regulator of glucose homeostasis, quantitative models describing the dynamics of glucose-induced insulin secretion are of obvious interest. Here, a computational model is introduced that focuses not on organism-level concentrations, but on the quantitative modeling of local, cellular-level glucose-insulin dynamics by incorporating the detailed spatial distribution of the concentrations of interest within isolated avascular pancreatic islets. METHODS All nutrient consumption and hormone release rates were assumed to follow Hill-type sigmoid dependences on local concentrations. Insulin secretion rates depend on both the glucose concentration and its time-gradient, resulting in second-and first-phase responses, respectively. Since hypoxia may also be an important limiting factor in avascular islets, oxygen and cell viability considerations were also built in by incorporating and extending our previous islet cell oxygen consumption model. A finite element method (FEM) framework is used to combine reactive rates with mass transport by convection and diffusion as well as fluid-mechanics. RESULTS The model was calibrated using experimental results from dynamic glucose-stimulated insulin release (GSIR) perifusion studies with isolated islets. Further optimization is still needed, but calculated insulin responses to stepwise increments in the incoming glucose concentration are in good agreement with existing experimental insulin release data characterizing glucose and oxygen dependence. The model makes possible the detailed description of the intraislet spatial distributions of insulin, glucose, and oxygen levels. In agreement with recent observations, modeling also suggests that smaller islets perform better when transplanted and/or encapsulated. CONCLUSIONS An insulin secretion model was implemented by coupling local consumption and release rates to calculations of the spatial distributions of all species of interest. The resulting glucose-insulin control system fits in the general framework of a sigmoid proportional-integral-derivative controller, a generalized PID controller, more suitable for biological systems, which are always nonlinear due to the maximum response being limited. Because of the general framework of the implementation, simulations can be carried out for arbitrary geometries including cultured, perifused, transplanted, and encapsulated islets.
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Affiliation(s)
- Peter Buchwald
- Diabetes Research Institute and the Department of Molecular and Cellular Pharmacology, University of Miami, Miller School of Medicine, Miami, FL, USA.
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Johnson AS, O'Sullivan E, D'Aoust LN, Omer A, Bonner-Weir S, Fisher RJ, Weir GC, Colton CK. Quantitative assessment of islets of Langerhans encapsulated in alginate. Tissue Eng Part C Methods 2011; 17:435-49. [PMID: 21067465 DOI: 10.1089/ten.tec.2009.0510] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Improved methods have recently been developed for assessing islet viability and quantity in human islet preparations for transplantation, and these measurements have proven useful for predicting transplantation outcome. The objectives of this study were to adapt these methods for use with microencapsulated islets, to verify that they provide meaningful quantitative measurements, and to test them with two model systems: (1) barium alginate and (2) barium alginate containing a 70% (w/v) perfluorocarbon (PFC) emulsion, which presents challenges to use of these assays and is of interest in its own right as a means for reducing oxygen supply limitations to encapsulated tissue. Mitochondrial function was assessed by oxygen consumption rate measurements, and the analysis of data was modified to account for the increased solubility of oxygen in the PFC-alginate capsules. Capsules were dissolved and tissue recovered for nuclei counting to measure the number of cells. Capsule volume was determined from alginate or PFC content and used to normalize measurements. After low oxygen culture for 2 days, islets in normal alginate lost substantial viable tissue and displayed necrotic cores, whereas most of the original oxygen consumption rate was recovered with PFC alginate, and little necrosis was observed. All nuclei were recovered with normal alginate, but some nuclei from nonrespiring cells were lost with PFC alginate. Biocompatibility tests revealed toxicity at the islet periphery associated with the lipid emulsion used to provide surfactants during the emulsification process. We conclude that these new assay methods can be applied to islets encapsulated in materials as complex as PFC-alginate. Measurements made with these materials revealed that enhancement of oxygen permeability of the encapsulating material with a concentrated PFC emulsion improves survival of encapsulated islets under hypoxic conditions, but reformulation of the PFC emulsion is needed to reduce toxicity.
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Affiliation(s)
- Amy S Johnson
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307, USA
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Goto M, Imura T, Inagaki A, Ogawa N, Yamaya H, Fujimori K, Kurokawa Y, Satomi S. The impact of ischemic stress on the quality of isolated pancreatic islets. Transplant Proc 2011; 42:2040-2. [PMID: 20692402 DOI: 10.1016/j.transproceed.2010.05.101] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Although the ischemic stress of donated organs has been shown to have strong negative effects on islet recovery, the impact on islet quality remains uncertain. In the present study, therefore, we examined the influence of ischemic stress on the expression of inflammatory mediators among isolated islets. MATERIALS AND METHODS Islets were isolated from adult porcine pancreata subjected to 16-hour cold ischemia time (CIT) in addition to 40-minute warm ischemia time (WIT). We evaluated the islet yield, islet loss during the first 24 hours in culture, adenosine diphosphate (ADP)/adenosine triphosphate (ATP) ratio, ATP/DNA ratio, glucose-stimulated respiratory activity, in vivo bioassay, and the expression of inflammatory mediators (tissue factor [TF], [MCP-1], macrophage migration inhibitory factor) on the isolated islets. We also analyzed ATP/DNA ratios of the exocrine tissues during isolation procedures. RESULTS The islet yield, survival rate during culture, and glucose-stimulated respiratory activity were significantly lower in cases of 16-hour CIT plus 40-minute WIT compared with the control group (P < .0001, .0006, and .002, respectively). In contrast, ADP/ATP ratio as well as TF and MCP-1 expressions on the isolated islets were higher among the ischemic group (P = .005, .16, and .005, respectively). During isolation procedures, the ATP/DNA of the exocrine tissues was extremely lower in the ischemic compared to the control group (P < .0001). Notably, however, both ATP/DNA and ADP/ATP ratio of isolated islets were well preserved even in the ischemic group (P = .45 and .40). DISCUSSION These data suggest that ischemic stress during the preservation period negatively affects the energy status of exocrine tissues. Destruction of the exocrine tissues, in combination with warm ischemic stress during the isolation procedures, subsequently decreases isolated islet activity, inducing the expression of inflammatory mediators.
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Affiliation(s)
- M Goto
- Tohoku University International Advanced Research and Education Organization, Tohoku University, Sendai, Japan.
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Saito Y, Goto M, Maya K, Ogawa N, Fujimori K, Kurokawa Y, Satomi S. Brain Death in Combination with Warm Ischemic Stress during Isolation Procedures Induces the Expression of Crucial Inflammatory Mediators in the Isolated Islets. Cell Transplant 2010; 19:775-82. [DOI: 10.3727/096368910x508889] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Tissue factor (TF) and monocyte chemoattractant protein-1 (MCP-1) expressed on the islets have been identified as the main trigger of the instant blood-mediated inflammatory reaction (IBMIR) in islet transplantation. Because the key steps that directly induce TF and MCP-1 remain to be determined, we focused on the influence of brain death (BD) on TF and MCP-1 expression in the pancreatic tissues and isolated islets using a rodent model. TF and MCP-1 mRNA levels in the pancreatic tissues were similar between the BD and the control group. However, TF and MCP-1 mRNA in the fresh islets of the BD group were significantly higher than that of the control group ( p < 0.01). BD may thus be suggested to be of great importance as an initiator of TF and MCP-1 induction in the isolated islets. Furthermore, the upregulation of crucial inflammatory mediators induced by BD could be exacerbated by warm ischemic damage during digestion procedures. In the present study, the islet yield and purity were affected by BD. However, almost no influences were observed with respect to islet viability, indicating that the expression of inflammatory mediators rather than islet viability is more susceptible to BD. According to the change in time course of TF and MCP-1 expression in the isolated islets, the selected time point for islet infusion in current clinical islet transplantation was thus shown to be at its worst level, at least with respect to the damage caused by BD and ischemic stress. In conclusion, BD in combination with warm ischemic stress during isolation procedures induces a high expression of TF and MCP-1 in the isolated islets. In order to reduce the expression of crucial inflammatory mediators in the islet grafts, the management of the pancreas from brain-dead donors with early anti-inflammatory treatments is thus warranted.
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Affiliation(s)
- Yukihiko Saito
- Division of Advanced Surgical Science and Technology, Tohoku University, Sendai, Japan
| | - Masafumi Goto
- Division of Advanced Surgical Science and Technology, Tohoku University, Sendai, Japan
- Tohoku University International Advanced Research and Education Organization, Tohoku University, Sendai, Japan
| | - Kozue Maya
- Tohoku University International Advanced Research and Education Organization, Tohoku University, Sendai, Japan
| | - Norihiko Ogawa
- Division of Advanced Surgical Science and Technology, Tohoku University, Sendai, Japan
| | - Keisei Fujimori
- Medical Safety Management Office, Tohoku University, Sendai, Japan
| | - Yoshimochi Kurokawa
- Tohoku University Innovation of New Biomedical Engineering Center, Tohoku University, Sendai, Japan
| | - Susumu Satomi
- Division of Advanced Surgical Science and Technology, Tohoku University, Sendai, Japan
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Abstract
PURPOSE OF REVIEW There is a critical need for meaningful viability and potency assays that characterize islet preparations for release prior to clinical islet cell transplantation. Development, testing, and validation of such assays have been the subject of intense investigation for the last decade. These efforts are reviewed, highlighting the most recent results while focusing on the most promising assays. RECENT FINDINGS Assays based on membrane integrity do not reflect true viability when applied to either intact islets or dispersed islet cells. Assays requiring disaggregation of intact islets into individual cells for assessment introduce additional problems of cell damage and loss. Assays evaluating mitochondrial function, specifically mitochondrial membrane potential, bioenergetic status, and cellular oxygen consumption rate, especially when conducted with intact islets, appear most promising in evaluating their quality prior to islet cell transplantation. Prospective, quantitative assays based on measurements of oxygen consumption rate with intact islets have been developed, validated, and their results correlated with transplant outcomes in the diabetic nude mouse bioassay. CONCLUSION More sensitive and reliable islet viability and potency tests have been recently developed and tested. Those evaluating mitochondrial function are most promising, correlate with transplant outcomes in mice, and are currently being evaluated in the clinical setting.
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Schulte A, Nebel M, Schuhmann W. Scanning electrochemical microscopy in neuroscience. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2010; 3:299-318. [PMID: 20636044 DOI: 10.1146/annurev.anchem.111808.073651] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
This article reviews recent work involving the application of scanning electrochemical microscopy (SECM) to the study of individual cultured living cells, with an emphasis on topographical and functional imaging of neuronal and secretory cells of the nervous and endocrine system. The basic principles of biological SECM and associated negative amperometric-feedback and generator/collector-mode SECM imaging are discussed, and successful use of the methodology for screening soft and fragile membranous objects is outlined. The drawbacks of the constant-height mode of probe movement and the benefits of the constant-distance mode of SECM operation are described. Finally, representative examples of constant-height and constant-distance mode SECM on a variety of live cells are highlighted to demonstrate the current status of single-cell SECM in general and of SECM in neuroscience in particular.
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Affiliation(s)
- Albert Schulte
- Institute of Science, Suranaree University of Technology, Nakhon Ratchasima, Thailand.
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