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Einstein SA, Steyn LV, Weegman BP, Suszynski TM, Sambanis A, O'Brien TD, Avgoustiniatos ES, Firpo MT, Graham ML, Janecek J, Eberly LE, Garwood M, Putnam CW, Papas KK. Hypoxia within subcutaneously implanted macroencapsulation devices limits the viability and functionality of densely loaded islets. FRONTIERS IN TRANSPLANTATION 2023; 2:1257029. [PMID: 38993891 PMCID: PMC11235299 DOI: 10.3389/frtra.2023.1257029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 10/20/2023] [Indexed: 07/13/2024]
Abstract
Introduction Subcutaneous macroencapsulation devices circumvent disadvantages of intraportal islet therapy. However, a curative dose of islets within reasonably sized devices requires dense cell packing. We measured internal PO2 of implanted devices, mathematically modeled oxygen availability within devices and tested the predictions with implanted devices containing densely packed human islets. Methods Partial pressure of oxygen (PO2) within implanted empty devices was measured by noninvasive 19F-MRS. A mathematical model was constructed, predicting internal PO2, viability and functionality of densely packed islets as a function of external PO2. Finally, viability was measured by oxygen consumption rate (OCR) in day 7 explants loaded at various islet densities. Results In empty devices, PO2 was 12 mmHg or lower, despite successful external vascularization. Devices loaded with human islets implanted for 7 days, then explanted and assessed by OCR confirmed trends proffered by the model but viability was substantially lower than predicted. Co-localization of insulin and caspase-3 immunostaining suggested that apoptosis contributed to loss of beta cells. Discussion Measured PO2 within empty devices declined during the first few days post-transplant then modestly increased with neovascularization around the device. Viability of islets is inversely related to islet density within devices.
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Affiliation(s)
- Samuel A Einstein
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, United States
- Department of Radiology, The Pennsylvania State University, Hershey, PA, United States
| | - Leah V Steyn
- Department of Surgery, University of Arizona, Tucson, AZ, United States
| | - Bradley P Weegman
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, United States
- Sylvatica Biotech Inc., North Charleston, SC, United States
| | - Thomas M Suszynski
- Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Athanassios Sambanis
- Department of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, United States
| | - Timothy D O'Brien
- Veterinary Population Medicine Department, University of Minnesota, Saint Paul, MN, United States
- Department of Medicine, Stem Cell Institute, University of Minnesota, Minneapolis, MN, United States
| | | | - Meri T Firpo
- Department of Medicine, Stem Cell Institute, University of Minnesota, Minneapolis, MN, United States
| | - Melanie L Graham
- Veterinary Population Medicine Department, University of Minnesota, Saint Paul, MN, United States
- Department of Surgery, Preclinical Research Center, University of Minnesota, Saint Paul, MN, United States
| | - Jody Janecek
- Department of Surgery, Preclinical Research Center, University of Minnesota, Saint Paul, MN, United States
| | - Lynn E Eberly
- Division of Biostatistics, University of Minnesota, Minneapolis, MN, United States
| | - Michael Garwood
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, United States
| | - Charles W Putnam
- Department of Surgery, University of Arizona, Tucson, AZ, United States
| | - Klearchos K Papas
- Department of Surgery, University of Arizona, Tucson, AZ, United States
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Landstra CP, Nijhoff MF, Roelen DL, de Vries APJ, de Koning EJP. Diagnosis and treatment of allograft rejection in islet transplantation. Am J Transplant 2023; 23:1425-1433. [PMID: 37307954 DOI: 10.1016/j.ajt.2023.05.035] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 05/07/2023] [Indexed: 06/14/2023]
Abstract
Islet transplantation stabilizes glycemic control in patients with complicated diabetes mellitus. Rapid functional decline could be due to islet allograft rejection. However, there is no reliable method to assess rejection, and treatment protocols are absent. We aimed to characterize diagnostic features of islet allograft rejection and assess effectiveness of high-dose methylprednisolone treatment. Over a median follow-up of 61.8 months, 22% (9 of 41) of islet transplant recipients experienced 10 suspected rejection episodes (SREs). All first SREs occurred within 18 months after transplantation. Important features were unexplained hyperglycemia (all cases), unexplained C-peptide decrease (ΔC-peptide, 77.1% [-59.1% to -91.6%]; ΔC-peptide:glucose, -76.3% [-49.2% to -90.4%]), predisposing event (5 of 10 cases), and increased immunologic risk (5 of 10 cases). At 6 months post-SRE, patients who received protocolized methylprednisolone (n = 4) had significantly better islet function than untreated patients (n = 4), according to C-peptide (1.39 ± 0.59 vs 0.14 ± 0.19 nmol/L; P = .007), Igls score (good [4 of 4 cases] vs failure [3 of 4 cases] or marginal [1 of 4 cases]; P = .018) and β score (6.0 [6.0-6.0] vs 1.0 [0.0-3.5]; P = .013). SREs are prevalent among islet transplant recipients and are associated with loss of islet graft function. Timely treatment with high-dose methylprednisolone mitigates this loss. Unexplained hyperglycemia, unexpected C-peptide decrease, a predisposing event, and elevated immunologic risk are diagnostic indicators for SRE.
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Affiliation(s)
- Cyril P Landstra
- Department of Internal Medicine, Leiden University Medical Center, Leiden, The Netherlands
| | - Michiel F Nijhoff
- Department of Internal Medicine, Leiden University Medical Center, Leiden, The Netherlands; Leiden Transplant Center, Leiden University Medical Center, Leiden, The Netherlands
| | - Dave L Roelen
- Leiden Transplant Center, Leiden University Medical Center, Leiden, The Netherlands; Department of Immunohematology, Leiden University Medical Center, Leiden, The Netherlands
| | - Aiko P J de Vries
- Department of Internal Medicine, Leiden University Medical Center, Leiden, The Netherlands; Leiden Transplant Center, Leiden University Medical Center, Leiden, The Netherlands
| | - Eelco J P de Koning
- Department of Internal Medicine, Leiden University Medical Center, Leiden, The Netherlands; Leiden Transplant Center, Leiden University Medical Center, Leiden, The Netherlands.
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Safety Evaluation of Oral Sirolimus in the Treatment of Childhood Diseases: A Systematic Review. CHILDREN (BASEL, SWITZERLAND) 2022; 9:children9091295. [PMID: 36138604 PMCID: PMC9497617 DOI: 10.3390/children9091295] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 08/18/2022] [Accepted: 08/24/2022] [Indexed: 11/17/2022]
Abstract
Background: Sirolimus, a mammalian target of rapamycin inhibitor, has been widely used in pediatric patients, but the safety of sirolimus in pediatric patients has not been well determined. Objective: The objective of this study was to systematically evaluate prospective studies reporting the safety of sirolimus in the treatment of childhood diseases. Methods: The following data were extracted in a standardized manner: study design, demographic characteristics, intervention, and safety outcomes. Results: In total, 9 studies were included, encompassing 575 patients who received oral sirolimus for at least 6 months. Various adverse events occurred. The most common adverse event was oral mucositis (8.2%, 95% CI: 0.054 to 0.110). Through comparative analysis of the subgroups based on the targeted concentration range, we discovered that many adverse events were significantly higher in the high concentration group (≥10 ng/mL) than in the low concentration group (<10 ng/mL) (p < 0.01). More interestingly, we found that oral mucositis was more frequently reported in children with vascular anomalies than tuberous sclerosis complex. Conclusions: This study shows that oral sirolimus in the treatment of childhood diseases is safe and reliable. However, sirolimus treatment in the pediatric population should be strictly monitored to reduce the occurrence of serious or fatal adverse events.
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Pancreatic Islet Changes in Human Whole Organ Pancreas Explants: What Can Be Learned From Explanted Samples? Transplant Direct 2020; 6:e613. [PMID: 33134489 PMCID: PMC7575169 DOI: 10.1097/txd.0000000000001059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 06/24/2020] [Accepted: 07/14/2020] [Indexed: 01/09/2023] Open
Abstract
Background. Whole pancreas transplantation (Tx) is a successful treatment for type 1 diabetes resulting in independence from antidiabetic therapies. Transplant-related factors contributing to pancreatic islet failure are largely unknown; both recurring insulitis and pancreatitis have been implicated. The aim was to determine if cellular changes in islets and exocrine tissue are evident early in Tx, which could contribute to eventual graft failure using well-preserved tissue of grafts explanted from largely normoglycemic recipients. Methods. Histological specimens of explants (n = 31), Tx duration 1 day–8 years (median 29 d), cold ischemia time 7.2–17.3 hours (median 11.1 h), donor age 13–54 years (median 38 y) were examined; sections were labeled for inflammation, islet amyloidosis, and tissue fibrosis, and morphometry performed on immunolabeled insulin and glucagon positive islet cells. Data were related to clinical details of donor, recipient, and features of Tx. Results. Islet inflammation consistent with recurrent insulitis was not seen in any sample. Insulin-labeled islet cell proportion decreased with donor age (P < 0.05) and cold ischemia (P < 0.01) in explants from 26 normoglycemic patients; glucagon-labeled area proportion increased with cold ischemia (P < 0.05). Clinical pancreatitis was the explant reason in 12 of 28 normoglycemic cases. Exocrine fibrotic area/pancreas was variable (0.7%–55%) and unrelated to clinical/pathological features. Islet amyloid was present in 3 normoglycemic cases (donor ages 58, 42, and 31 y; Tx duration 8 y, 31 and 33 d, respectively). In 1 patient receiving antidiabetic therapy, the insulin-labeled area was reduced but with no evidence of islet inflammation. Conclusions. Explant histological changes after short-term Tx are similar to those seen in type 2 diabetes and occur in the absence of immunologic rejection without causing hyperglycemia. This suggests that factors associated with Tx affect islet stability; persistent deterioration of islet integrity and exocrine tissue fibrosis could impact on sustainability of islet function.
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Kolic J, Beet L, Overby P, Cen HH, Panzhinskiy E, Ure DR, Cross JL, Huizinga RB, Johnson JD. Differential Effects of Voclosporin and Tacrolimus on Insulin Secretion From Human Islets. Endocrinology 2020; 161:5902465. [PMID: 32894758 PMCID: PMC7567406 DOI: 10.1210/endocr/bqaa162] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 09/02/2020] [Indexed: 12/16/2022]
Abstract
The incidence of new onset diabetes after transplant (NODAT) has increased over the past decade, likely due to calcineurin inhibitor-based immunosuppressants, including tacrolimus (TAC) and cyclosporin. Voclosporin (VCS), a next-generation calcineurin inhibitor, is reported to cause fewer incidences of NODAT but the reason is unclear. While calcineurin signaling plays important roles in pancreatic β-cell survival, proliferation, and function, its effects on human β-cells remain understudied. In particular, we do not understand why some calcineurin inhibitors have more profound effects on the incidence of NODAT. We compared the effects of TAC and VCS on the dynamics of insulin secretory function, programmed cell death rate, and the transcriptomic profile of human islets. We studied 2 clinically relevant doses of TAC (10 ng/mL, 30 ng/mL) and VCS (20 ng/mL, 60 ng/mL), meant to approximate the clinical trough and peak concentrations. TAC, but not VCS, caused a significant impairment of 15 mM glucose-stimulated and 30 mM KCl-stimulated insulin secretion. This points to molecular defects in the distal stages of exocytosis after voltage-gated Ca2+ entry. No significant effects on islet cell survival or total insulin content were identified. RNA sequencing showed that TAC significantly decreased the expression of 17 genes, including direct and indirect regulators of exocytosis (SYT16, TBC1D30, PCK1, SMOC1, SYT5, PDK4, and CREM), whereas VCS has less broad, and milder, effects on gene expression. Clinically relevant doses of TAC, but not VCS, directly inhibit insulin secretion from human islets, likely via transcriptional control of exocytosis machinery.
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Affiliation(s)
- Jelena Kolic
- Diabetes Research Group, Life Sciences Institute, Department of Cellular and Physiological Sciences & Department of Surgery, University of British Columbia, Vancouver, Canada
| | - Leanne Beet
- Diabetes Research Group, Life Sciences Institute, Department of Cellular and Physiological Sciences & Department of Surgery, University of British Columbia, Vancouver, Canada
| | - Peter Overby
- Diabetes Research Group, Life Sciences Institute, Department of Cellular and Physiological Sciences & Department of Surgery, University of British Columbia, Vancouver, Canada
| | - Haoning Howard Cen
- Diabetes Research Group, Life Sciences Institute, Department of Cellular and Physiological Sciences & Department of Surgery, University of British Columbia, Vancouver, Canada
| | - Evgeniy Panzhinskiy
- Diabetes Research Group, Life Sciences Institute, Department of Cellular and Physiological Sciences & Department of Surgery, University of British Columbia, Vancouver, Canada
| | - Daren R Ure
- Hepion Pharmaceuticals, Edmonton, Alberta, Canada
| | | | | | - James D Johnson
- Correspondence: Professor James D. Johnson, PhD, Faculty of Medicine, Department of Cellular and Physiological Sciences & Department of Surgery, The University of British Columbia, Life Sciences Institute, 5358 – 2350 Health Sciences Mall, Vancouver, British Columbia, Canada, V6T 1Z3. E-mail: ; Twitter: @JimJohnsonSci
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Differential influence of tacrolimus and sirolimus on mitochondrial-dependent signaling for apoptosis in pancreatic cells. Mol Cell Biochem 2016; 418:91-102. [PMID: 27344165 DOI: 10.1007/s11010-016-2736-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 06/15/2016] [Indexed: 01/21/2023]
Abstract
To examine and compare the mitochondria-related cellular mechanisms by which tacrolimus (TAC) or sirolimus (SIR) immunosuppressive drugs alter the pancreatic exocrine and endocrine β-cell fate. Human exocrine PANC-1 and rat endocrine insulin-secreting RIN-m5F cells and isolated rat islets were submitted to 1-100 nM TAC or SIR. In cultures, insulin secretion was measured as endocrine cell function marker. Apoptosis was quantified by annexin 5 and propidium iodide staining. Cleaved caspase-3, Bax apoptosis indicators, and p53, p21 cell cycle regulators were detected by Western blot. Cell cycle and mitochondrial membrane potential (ΔΨm) were analyzed by flow cytometry and SA-beta-galactosidase (SA-β-gal) activity by fluorescence microscopy. Only TAC reduced insulin secretion by RIN-m5F after 24 h. TAC and SIR promoted moderate apoptosis in both PANC-1 and RIN-m5F after 24 h. Apoptosis was associated with up-regulated Bax (threefold) and cleaved caspase-3 (fivefold) but only in PANC-1, while p53 and p21 were up-regulated (twofold) in both cell lines. ΔΨm was impaired only in PANC-1 by TAC and SIR. Only SIR prompted cell cycle arrest in both cell lines. The induction of a premature senescence-like phenotype was confirmed in isolated islets by SA-β-gal activity. TAC and SIR are early inducers of pancreatic cell dysfunction and apoptosis but differentially alter endocrine and exocrine cells via mitochondrial-driven pathways. In rat islets, TAC and SIR prompt a senescence-like phenotype.
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