Towards the Development of a Bioartificial Pancreas: Effects of Poly-l-Lysine on Alginate Beads with BTC3 Cells

1997 ◽  
Vol 6 (4) ◽  
pp. 395-402 ◽  
Author(s):  
J.P. Benson ◽  
K.K. Papas ◽  
I. Constantinidis ◽  
A. Sambanis
Keyword(s):  
Type I Diabetes ◽  
Alginate Beads ◽  
Transformed Cells ◽  
Type I ◽  
Cell Aggregates ◽  
Bioartificial Pancreas ◽  
Insulin Secreting Cells ◽  
Tissue Construct

A bioartificial tissue construct that consists of insulin-secreting cells entrapped in an alginate/poly-l-lysine (PLL) matrix offers a promising approach for the treatment of type I diabetes. Use of transformed cells has been proposed as a solution to the cell availability problem posed by islets. The growth characteristics of transformed cells in their sequestered environment and the effects of PLL on their metabolic and secretory activities have not yet been characterized. Our data demonstrate that mouse insulinoma βTC3 cells proliferate while they are entrapped in both PLL-free and PLL-coated alginate beads. During this process, cell aggregates develop in the bead periphery, which increase in number and size with time. PLL is crucial for the long-term in vitro structural stability of beads, and it does not appear to affect the metabolic and secretory activities of entrapped βTC3 cells. The implications of these findings in the development of a bioartificial pancreatic construct based on transformed cells are discussed.

Effects of long-term optimization and short-term deterioration of glycemic control on glucose counterregulation in type I diabetes mellitus

Diabetes ◽  
1984 ◽  
Vol 33 (4) ◽  
pp. 394-400 ◽  
Author(s):  
G. Bolli ◽  
P. De Feo ◽  
S. De Cosmo ◽  
G. Perriello ◽  
G. Angeletti ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Glycemic Control ◽  
Type I Diabetes ◽  
Type I Diabetes Mellitus ◽  
Type I ◽  
Short Term

scholarly journals Tolerance and pancreatic islet transplantation

2001 ◽  
Vol 356 (1409) ◽  
pp. 759-765 ◽  
Author(s):  
Luca Inverardi ◽  
Camillo Ricordi
Keyword(s):  
Diabetes Mellitus ◽  
Islet Transplantation ◽  
Type I Diabetes ◽  
Immunological Tolerance ◽  
Type I Diabetes Mellitus ◽  
Current Status ◽  
Type I ◽  
Pancreatic Islet Transplantation ◽  
Term Survival

Islet transplantation holds renewed promise as a cure for type I diabetes mellitus. Results of recent clinical trials have shown remarkable success, and have reignited universal optimism for this procedure. In spite of this success, the need for life–long immunosuppression of the recipient still limits islet transplantation to patients with poorly controlled diabetes or to those requiring kidney transplantation. It is obvious that the achievement of immunological tolerance would broaden the indication for islet transplantation to a much larger cohort of patients with type I diabetes mellitus, most likely preventing long–term complications and contributing to a much improved quality of life. Increased understanding of the basic mechanisms of tolerance induction has resulted in the implementation of numerous experimental approaches to achieve long–term survival of islet grafts in the absence of chronic immunosuppression. In this brief review we will attempt to summarize the current status of research and knowledge.

scholarly journals No Evidence of Viral Transmission following Long-Term Implantation of Agarose Encapsulated Porcine Islets in Diabetic Dogs

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Lawrence S. Gazda ◽  
Horatiu V. Vinerean ◽  
Melissa A. Laramore ◽  
Richard D. Hall ◽  
Joseph W. Carraway ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Type I Diabetes ◽  
Viral Transmission ◽  
Type I Diabetes Mellitus ◽  
Type I ◽  
Safe Procedure ◽  
C Peptide ◽  
Porcine Islets ◽  
Diabetic Dogs

We have previously described the use of a double coated agarose-agarose porcine islet macrobead for the treatment of type I diabetes mellitus. In the current study, the long-term viral safety of macrobead implantation into pancreatectomized diabetic dogs treated with pravastatin (n=3) was assessed while 2 dogs served as nonimplanted controls. A more gradual return to preimplant insulin requirements occurred after a 2nd implant procedure (days 148, 189, and >652) when compared to a first macrobead implantation (days 9, 21, and 21) in all macrobead implanted animals. In all three implanted dogs, porcine C-peptide was detected in the blood for at least 10 days following the first implant and for at least 26 days following the second implant. C-peptide was also present in the peritoneal fluid of all three implanted dogs at 6 months after 2nd implant and in 2 of 3 dogs at necropsy. Prescreening results of islet macrobeads and culture media prior to transplantation were negative for 13 viruses. No evidence of PERV or other viral transmission was found throughout the study. This study demonstrates that the long-term (2.4 years) implantation of agarose-agarose encapsulated porcine islets is a safe procedure in a large animal model of type I diabetes mellitus.

DISTINCTIVE FEATURES OF PROCOAGULANT RESPONSE OF MONOCYTES FROM DIABETIC PATIENTS

1987 ◽  
Author(s):  
B JUDE ◽  
A WATEL ◽  
D FONTAINE ◽  
P FONTAINE ◽  
A COSSON
Keyword(s):  
Type I Diabetes ◽  
Vascular Complications ◽  
Coagulation Factor ◽  
Factor Vii ◽  
Diabetic Patients ◽  
Type I ◽  
Factor X ◽  
Female Ratio ◽  
Male Female Ratio

Hypercoagulability is one of the possible factors reported in genesis or aggravation of vascular complications in diabetes mellitus. We therefore examined procoagulant activity (PCA) of disrupted monocytes frcm 26 patients with Type I diabetes and 6 with Type II, versus 32 control subjects (male/ female ratio = 1 in each group).Diabetes monocytes exhibited a slight but detectable PCA before any incubation or in vitro stimulation, whereas control monocytes did not. Data obtained with coagulation factor deficient plasmas or phospholipase C indicated that PCA was tissue factor (TF) alone in 22 cases and TF associated with a significant amount of factor VII/VIIa activity in 10 cases.Incubation in serum free medium led to significant raise of PCA in diabetes cells when stimulated with endotoxin or not, and in control cells only after stimulation. Furthermore, PCA appeared earlier in diabetes monocytes than in control ones, (4 hours, versus 20 hours). PCA frcm control cells was FT-like. PCA frcm diabetes cells was FT-like when no VII/VIIa activity was present on non-stimulated cells, and prothrombinase-like when VII/VIIa activity was early associated with the cells. In the latter case, trace amounts of factor X activity were also detectable. Whether factor VII and factor X activities were of plasmatic origin and associated to the cells, or synthesized in vitro by the cells remains unclear. The characteristics of PCA were net correlated with clinical features (age, diabetic complications) nor with the type of diabetes.Our data suggest that in diabetes patients, monocytes exhibit an increased PCA, possibly corresponding to a baseline stimulation, or at least a higher responsiveness to undergoing stimuli in vitro.

Characterization of insulin glycation in insulin-secreting cells maintained in tissue culture

1997 ◽  
Vol 152 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Y H A Abdel-Wahab ◽  
F P M O'Harte ◽  
C R Barnett ◽  
P R Flatt
Keyword(s):  
Tissue Culture ◽  
Secretory Activity ◽  
Protein Glycation ◽  
Subsequent Exposure ◽  
Insulin Secreting Cells ◽  
Per Se ◽  
Stimulation Of

Abstract Characteristics of cellular insulin glycation were examined in the pancreatic B-cell line, BRIN-BD11. The extent of insulin glycation increased stepwise during 72 h of culture at 5·6–33·3 mmol/l glucose, attaining levels up to 27%. Glycation of insulin at 33·3 mmol/l glucose was rapid, reaching maximal values within 2 h, and not readily reversible during 2 to 24 h of subsequent exposure to 5·6 mmol/l glucose. Glycated insulin was readily secreted by BRIN-BD11 cells upon active stimulation with glucose and other secretagogues. Cellular insulin glycation was decreased by 66–80% by inhibitors of protein glycation, vitamin C, aminoguanidine or acetylsalicylic acid. Modulation of insulin-secretory activity of BRIN-BD11 cells by co-culture at high glucose with diazoxide, l-alanine or glibenclamide indicated that long-term stimulation of secretion was associated with a decrease in the extent of insulin glycation. Glycation of insulin in vitro was substantially less extensive than in BRIN-BD11 cells, although glucose-6-phosphate and glyceraldehyde-3-phosphate were 1·4- to 2·0-fold more reactive than glucose per se. These observations indicate that insulin is readily glycated and secreted from insulin-secreting cells under hyperglycaemic conditions in culture. Journal of Endocrinology (1997) 152, 59–67

scholarly journals In vitro morphogenesis of chick embryo hypertrophic cartilage.

1987 ◽  
Vol 105 (2) ◽  
pp. 999-1006 ◽  
Author(s):  
C Tacchetti ◽  
R Quarto ◽  
L Nitsch ◽  
D J Hartmann ◽  
R Cancedda
Keyword(s):  
Chick Embryo ◽  
Type I ◽  
Cell Aggregates ◽  
In Vitro Morphogenesis ◽  
Temporal And Spatial Distribution ◽  
Hypertrophic Cartilage ◽  
Histologic Appearance ◽  
Temporal And Spatial

Dedifferentiated chick embryo chondrocytes (Castagnola, P., G. Moro, F. Descalzi-Cancedda, and R. Cancedda, 1986, J. Cell Biol., 102:2310-2317), when transferred to suspension culture on agarose-coated dishes in the presence of ascorbic acid, aggregate and remain clustered. With time in culture, clusters grow in size and adhere to each other, forming structures that may be several millimeters in dimension. These structures after 7 d of culture have the histologic appearance of mature hypertrophic cartilage partially surrounded by a layer of elongated cells resembling the perichondrium. Cells inside the aggregates have ultrastructural features of stage I (proliferating) or stage II (hypertrophic) chondrocytes depending on their location. Occurrence and distribution of type I, II, and X collagens in the in vitro-formed cartilage at different times of culture, show a temporal and spatial distribution of these antigens reminiscent of the maturation events occurring in the cartilage in vivo. A comparable histologic appearance is shown also by cell aggregates obtained starting with a population of cells derived from a single, cloned, dedifferentiated chondrocyte.

Plasma endothelin-1 and total insulin exposure in diabetes mellitus

1999 ◽  
Vol 97 (2) ◽  
pp. 149-156 ◽  
Author(s):  
Flemming WOLLESEN ◽  
Lars BERGLUND ◽  
Christian BERNE
Keyword(s):  
Type Ii Diabetes ◽  
Type I Diabetes ◽  
Insulin Dose ◽  
Albumin Excretion Rate ◽  
Wall Structure ◽  
Type I ◽  
Type Ii ◽  
C Peptide ◽  
Patients With Diabetes

Insulin stimulates endothelin-1 (ET-1) expression in a dose-response relationship, and ET-1 effects on vascular wall structure are similar to the long-term complications of diabetes. We therefore determined whether the plasma ET-1 concentration in patients with diabetes is associated with their total insulin exposure to see if plasma ET-1 might be a link between insulin exposure and long-term complications of diabetes. We studied 69 patients with Type I and 40 patients with Type II diabetes mellitus in equally tight glycaemic control for 2 years in a cross-sectional design. We measured basal and glucagon-stimulated plasma C-peptide, abdominal sagittal diameter, skinfold thickness, glomerular filtration rate, albumin excretion rate and standard clinical characteristics. Mean HbA1c was 6.4% in Type I and 6.3% in Type II diabetes. Patients with an albumin excretion rate > 300 μg/min were excluded. Adjusted mean plasma ET-1 was 4.11 (S.E.M. 0.39) pg/ml in 21 normal subjects, 3.47 (0.19) pg/ml in Type I diabetes and 4.84 (0.26) pg/ml in Type II diabetes (P = 0.0001). In all patients with measurable plasma C-peptide, plasma ET-1 was associated with basal plasma C-peptide (r = 0.5018, P < 0.0001), with stimulated plasma C-peptide (r = 0.5379, P < 0.0001), and with total daily insulin dose (r = 0.2219, P = 0.00851). Abdominal obesity, metabolic abnormalities, blood pressure and glomerular filtration rate were not associated with plasma ET-1, when corrected for C-peptide and daily insulin dose. Our study shows that the plasma concentration of ET-1 is closely associated with insulin secretion and insulin dose in patients with diabetes. Plasma ET-1 is higher in Type II diabetes than in Type I diabetes. Increased insulin exposure in patients with diabetes may have long-term effects on vascular wall structure through its stimulation of ET-1 expression.

Constitutive TGF-β1 Deficiency Induces a Defect in Hematopoietic Stem/Progenitor Cell Compartment in Fetus and Neonate.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1397-1397
Author(s):  
Claude Capron ◽  
Catherine Lacout ◽  
Yann Lecluse ◽  
Valérie Jalbert ◽  
Elisabeth Cramer Bordé ◽  
...  
Keyword(s):  
Fetal Liver ◽  
Hematopoietic Cells ◽  
Type I ◽  
Activated T Cells ◽  
Hematopoietic Stem ◽  
Tgf Β1

Abstract TGF-β1 is a cytokine with pleiotropic effects. It has been considered that TGF-β1plays a major role on hematopoietic stem cells (HSC) based on in vitro experiment. Achieving in vivo experiments proved to be difficult because constitutive TGF-β1 knock-out (KO) in mice leads to lethality during the first 4 weeks of life from a wasting syndrome related to tissue infiltration by activated T cells and macrophages. For this reason, hematopoiesis of TGF-β1−/− mice has not been studied in details. In contrast the role of TGF-β1 has been recently extensively studied in conditional TGF-β type I receptor (TβRI) KO mice. No clear effect was observed on HSC functions, suggesting that TGF-β1 was not a key physiological regulator of hematopoiesis in the adult. However, these experiments have some limitations. They do not exclude a putative role for TGF-β1 during fetal hematopoiesis and they do not specifically address the role of TGF-β1 on hematopoiesis because KO of TGF-β receptor leads to signaling arrest for all TGF-βs. In addition, other receptors may be involved in TGF-β1 signaling. For these reasons, we have investigated the hematopoiesis of constitutive TGF-β1 KO mice with a mixed Sv129 × CF-1 genetic background allowing the birth of a high proportion of homozygotes. In 2 week-old neonate mice, we have shown a decrease of bone marrow (BM) and spleen progenitors and a decrease of immature progenitors colony forming unit of the spleen (CFU-s). Moreover this was associated with a loss in reconstitutive activity of TGF-β1−/− HSC from BM. However, although asymptomatic, these mice had an excess of activated lymphocytes and an augmentation of Sca-1 antigen on hematopoietic cells suggesting an excess of γ-interferon release. Thus we studied hematopoiesis of 7 to 10 days-old neonate mice, before phenotypic modification and inflammatory cytokine release. Similar results were observed with a decrease in the number of progenitors and in the proliferation of TGF-β1−/− BM cells along with an increased differentiation but without an augmentation in apoptosis. Moreoever, a loss of long term reconstitutive capacity of BM Lineage negative (Lin−) TGF-β1−/− cells along with a diminution of homing of TGF-β1−/− progenitors was found. These results demonstrate that TGF-β1 may play a major role on the HSC/Progenitor compartment in vivo and that this defect does not seem to be linked to the immune disease. To completely overpass the risk of the inflammatory syndrome, we analyzed hematopoiesis of fetal liver (FL) of TGF-β1−/− mice and still found a decrease in progenitors, a profound defect in the proliferative capacities, in long term reconstitutive activity and homing potential of primitive FL hematopoietic cells. Our results demonstrate that TGF-β1 plays an important role during hematopoietic embryonic development. Altogether these findings suggest that TGF-β1 is a potent positive regulator for the in vivo homeostasis of the HSC compartment.

scholarly journals The tyrosine kinase FRK/RAK participates in cytokine-induced islet cell cytotoxicity

2004 ◽  
Vol 382 (1) ◽  
pp. 261-268 ◽  
Author(s):  
Michael WELSH ◽  
Charlotte WELSH ◽  
Maria EKMAN ◽  
Johan DIXELIUS ◽  
Robert HÄGERKVIST ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Cell Death ◽  
Tyrosine Kinase ◽  
Tyrosine Kinases ◽  
Kinase Inhibitors ◽  
Type I Diabetes ◽  
Type I ◽  
Β Cell ◽  
Main Site

Hallmarks of the inflammatory process in Type I diabetes are macrophage activation, local release of β-cell-toxic cytokines and infiltration of cytotoxic T lymphocytes. We have observed recently that mice overexpressing active FRK (fyn-related kinase)/RAK (previously named GTK/Bsk/IYK, where GTK stands for gut tyrosine kinase, Bsk for β-cell Src-homology kinase and IYK for intestinal tyrosine kinase) in β-cells exhibit increased susceptibility to β-cell-toxic events, and therefore, we now attempt to find a more precise role for FRK/RAK in these processes. Phosphopeptide mapping of baculovirus-produced mouse FRK/RAK revealed an autophosphorylation pattern compatible with Tyr-394 being the main site. No evidence for in vitro phosphorylation of the C-terminal regulatory sites Tyr-497 and Tyr-504 was obtained, nor was there any indication of in vitro regulation of FRK/RAK kinase activity. Screening a panel of known tyrosine kinase inhibitors for their ability to inhibit FRK/RAK revealed several compounds that inhibited FRK/RAK, with a potency similar to that reported for their ability to inhibit other tyrosine kinases. Cytokine-induced islet toxicity was reduced in islets isolated from FRK/RAK knockout mice and this occurred without effects on the production of nitric oxide. Addition of the nitric oxide inhibitor nitroarginine to FRK/RAK knockout islets exposed to cytokines decreased cell death to a basal level. In normal islets, cytokine-induced cell death was inhibited by the addition of two FRK/RAK inhibitors, SU4984 and D-65495, or by transfection with short interfering RNA against FRK/RAK. It is concluded that FRK/RAK contributes to cytokine-induced β-cell death, and inhibition of this kinase could provide means to suppress β-cell destruction in Type I diabetes.

scholarly journals In vitro glycoxidation alters the interactions between collagens and human polymorphonuclear leucocytes

2000 ◽  
Vol 350 (3) ◽  
pp. 777-783 ◽  
Author(s):  
Jean-Claude MONBOISSE ◽  
Laure RITTIE ◽  
Hasnae LAMFARRAJ ◽  
Roselyne GARNOTEL ◽  
Philippe GILLERY
Keyword(s):  
Diabetes Mellitus ◽  
Type I Collagen ◽  
Inhibitory Effect ◽  
Type I ◽  
Polymorphonuclear Leucocytes ◽  
Type Iv ◽  
And Migration ◽  
Significant Stimulatory Effect

Glycation and glycoxidation processes, which are increased in diabetes mellitus, are generally considered causative mechanisms of long-term complications. With reference to our previous studies, type-I and -IV collagens could induce differentially the adhesion and stimulation of polymorphonuclear leucocytes (PMNs). As PMNs play a role in sustained diabetic oxidative stress, the present study was designed to determine whether in vitro glycoxidation of these macromolecules could alter PMN adhesion, activation and migration. The adhesion of PMNs to in vitro-glycoxidized collagens was significantly increased when compared with control collagens: +37% (P < 0.05) and +99% (P < 0.01) for collagens I and IV, respectively. Glycoxidized type-I collagen increased the chemotactic properties of PMNs without significant stimulatory effect on respiratory burst, whereas pre-incubation of PMNs with glycoxidized type-I collagen induced a priming on subsequent stimulation by N-formyl-methionyl-leucyl-phenylalanine. Glycoxidation of type-IV collagen suppressed its inhibitory effect on further PMN stimulation or migration. Collectively, these results indicate that glycoxidation of two major extracellular-matrix collagens considerably alters their ability to modulate PMN migration and production of reactive oxygen species. This imbalance in PMN metabolism may be a major event in the increased oxidative status that characterizes diabetes mellitus.

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