Key Matrix Proteins Within the Pancreatic Islet Basement Membrane Are Differentially Digested During Human Islet Isolation

Cross, Sarah E.; Vaughan, R H; Willcox, Abby; McBride, A.J.; Abraham, Anju; Han, Bing; Johnson, Janyne; Maillard, Élisa; Bateman, Paul A.; Ramracheya, Reshma; Rorsman, Patrik; Kadler, Karl E.; Dunne, Mark J.; Hughes, Stephen J.; Johnson, Paul

doi:10.1111/ajt.13975

Cited by 54 publications

(46 citation statements)

References 57 publications

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“…Tissue samples from control ( n = 3) and K ATP HI ( n = 3) after surgery were fixed and processed for transmission electron microscopy (TEM) and serial block face-scanning electron microscopy using a high-contrast protocol as previously described (24,25). Raw data files were converted to an MRC (Medical Research Council, U.K.) file stack using IMOD software (Boulder, CA) (http://bio3d.colorado.edu/imod/), which was also used in three-dimensional reconstruction (24,25). …”

Section: Methodsmentioning

confidence: 99%

Functional and Metabolomic Consequences of KATP Channel Inactivation in Human Islets

Ackermann

Boodhansingh

et al. 2017

Diabetes

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Loss-of-function mutations of β-cell KATP channels cause the most severe form of congenital hyperinsulinism (KATPHI). KATPHI is characterized by fasting and protein-induced hypoglycemia that is unresponsive to medical therapy. For a better understanding of the pathophysiology of KATPHI, we examined cytosolic calcium ([Ca2+]i), insulin secretion, oxygen consumption, and [U-13C]glucose metabolism in islets isolated from the pancreases of children with KATPHI who required pancreatectomy. Basal [Ca2+]i and insulin secretion were higher in KATPHI islets compared with controls. Unlike controls, insulin secretion in KATPHI islets increased in response to amino acids but not to glucose. KATPHI islets have an increased basal rate of oxygen consumption and mitochondrial mass. [U-13C]glucose metabolism showed a twofold increase in alanine levels and sixfold increase in 13C enrichment of alanine in KATPHI islets, suggesting increased rates of glycolysis. KATPHI islets also exhibited increased serine/glycine and glutamine biosynthesis. In contrast, KATPHI islets had low γ-aminobutyric acid (GABA) levels and lacked 13C incorporation into GABA in response to glucose stimulation. The expression of key genes involved in these metabolic pathways was significantly different in KATPHI β-cells compared with control, providing a mechanism for the observed changes. These findings demonstrate that the pathophysiology of KATPHI is complex, and they provide a framework for the identification of new potential therapeutic targets for this devastating condition.

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Section: Methodsmentioning

confidence: 99%

Functional and Metabolomic Consequences of KATP Channel Inactivation in Human Islets

Ackermann

Boodhansingh

et al. 2017

Diabetes

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“…T1D patients rely on life-long medication and treatment, such as exogeneous insulin replacement or, in more severe cases, immunosuppression after pancreatic b-cell transplantation. 4,5,6 Attempts toward the long-term treatment of T1D by b-cell transplantation frequently fails due to an impaired graft survival as a result of lost extracellular matrix (ECM) 7,8 or lack of vascularization accompanied by hypoxia after islet isolation. 4,9,10 The pancreas is a highly vascularized organ, 11 which is particularly true for the b-cell-containing islets of Langerhans, with a capillary density of 400 capillaries/mm 2 .…”

Section: Introductionmentioning

confidence: 99%

Controlled Heterotypic Pseudo-Islet Assembly of Human β-Cells and Human Umbilical Vein Endothelial Cells Using Magnetic Levitation

Urbanczyk

Zbinden

Layland

et al. 2020

Tissue Engineering Part A

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b-Cell functionality and survival are highly dependent on the cells' microenvironment and cell-cell interactions. Since the pancreas is a highly vascularized organ, the crosstalk between b-cells and endothelial cells (ECs) is vital to ensure proper function. To understand the interaction of pancreatic b-cells with vascular ECs, we sought to investigate the impact of the spatial distribution on the interaction of human cell line-based b-cells (EndoC-bH3) and human umbilical vein endothelial cells (HUVECs). We focused on the evaluation of three major spatial distributions, which can be found within human islets in vivo, in tissue-engineered heterotypic cell spheroids, socalled pseudo-islets, by controlling the aggregation process using magnetic levitation. We report that heterotypic spheroids formed by spontaneous aggregation cannot be maintained in culture due to HUVEC disassembly over time. In contrast, magnetic levitation allows the formation of stable heterotypic spheroids with defined spatial distribution and significantly facilitated HUVEC integration. To the best of our knowledge, this is the first study that introduces a human-only cell line-based in vitro test system composed of a coculture of b-cells and ECs with a successful stimulation of b-cell secretory function monitored by a glucose-stimulated insulin secretion assays. In addition, we systematically investigate the impact of the spatial distribution on cocultures of human b-cells and ECs, showing that the architecture of pseudo-islets significantly affects b-cell functionality.

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“…The pancreas digestion step, in particular, remains an empirical undertaking dependent on the activity of tissue‐digesting enzymes. Research efforts should focus on understanding the detailed molecular ultrastructure of the pancreatic islet‐exocrine matrix within the full range of donors (age, body mass index etc. ), and on developing new, targeted clinical grade enzyme (recombinant) blends that can be used on all available donor pancreata …”

Section: Refinements In Islet Transplantationmentioning

confidence: 99%

Current state and future evolution of pancreatic islet transplantation

Anazawa

Okajima

Masui

et al. 2018

Annals of Gastroent Surgery

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Pancreatic islet transplantation provides an effective treatment option for patients with type 1 diabetes (T1D) with intractable impaired awareness of hypoglycemia and severe hypoglycemic events. Currently, the primary goal of islet transplantation should be excellent glycemic control without severe hypoglycemia, rather than insulin independence. Islet transplant recipients were less likely to achieve insulin independence, whereas solid pancreas transplant recipients substantially had greater procedure‐related morbidity. Excellent therapeutic effects of islet transplantation as a result of accurate blood glucose level–reactive insulin secretion, which cannot be reproduced by current drug therapy, have been confirmed. Recent improvement of islet transplantation outcome has been achieved by refinement of the pancreatic islet isolation technique, improvement of islet engraftment method, and introduction of effective immunosuppressive therapy. A disadvantage of islet transplantation is that donors are essential, and donor shortage has become a hindrance to its development. With the development of alternative transplantation sites and new cell sources, including porcine islet cells and embryonic stem/induced pluripotent stem (ES/iPS)‐derived β cells, “On‐demand” and “Unlimited” cell therapy for T1D can be established.

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Key Matrix Proteins Within the Pancreatic Islet Basement Membrane Are Differentially Digested During Human Islet Isolation

Cited by 54 publications

References 57 publications

Functional and Metabolomic Consequences of KATP Channel Inactivation in Human Islets

Functional and Metabolomic Consequences of KATP Channel Inactivation in Human Islets

Controlled Heterotypic Pseudo-Islet Assembly of Human β-Cells and Human Umbilical Vein Endothelial Cells Using Magnetic Levitation

Current state and future evolution of pancreatic islet transplantation

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