ABSTRACT
The Collaborative Islet Transplant Registry (CITR) collects data on clinical islet isolations and transplants. This retrospective report analyzed 1017 islet isolation procedures performed for 537 recipients of allogeneic clinical islet transplantation in 1999-2010. This study describes changes in donor and islet isolation variables by era and factors associated with quantity and quality of final islet products. Donor body weight and BMI increased significantly over the period (p<0.001). Islet yield measures have improved with time including islet equivalent (IEQ)/particle ratio and IEQs infused. The average dose of islets infused significantly increased in the era of 2007-2010 when compared to 1999-2002 (445.4±156.8 vs. 421.3±155.4×0(3) IEQ; p<0.05). Islet purity and total number of ß cells significantly improved over the study period (p<0.01 and <0.05, respectively). Otherwise, the quality of clinical islets has remained consistently very high through this period, and differs substantially from nonclinical islets. In multivariate analysis of all recipient, donor and islet factors, and medical management factors, the only islet product characteristic that correlated with clinical outcomes was total IEQs infused. This analysis shows improvements in both quantity and some quality criteria of clinical islets produced over 1999-2010, and these parallel improvements in clinical outcomes over the same period.
Subject(s)
Graft Survival , Islets of Langerhans Transplantation , Registries , Adult , Female , Humans , Male , Middle AgedABSTRACT
Transplantation of mature islets into portal vein has been most effective thus far, although attrition of transplanted islets constitutes a major limitation, and alternative approaches are required. We analyzed the mechanisms by which islets engrafted, vascularized and functioned over the long term in the small intestinal submucosa. To determine engraftment, survival and function, 350 syngenic islets were transplanted into either intestinal segments or portal vein of diabetic rats. Islet reorganization, vascularization and function were analyzed by histological analysis, RT-PCR analysis as well as glycemic control over up to 1 year. Transplantation of syngeneic islets in marginal numbers successfully restored normoglycemia in diabetic rats. Transplantation of semi-pure islet preparation did not impair their engraftment, vascularization and function. Islets were morphologically intact and expressed insulin as well as glucagon over the year. Expression of angiogenic genes permitted revascularization of transplanted islets. We identified the expression of transcription factors required for maintenance of beta cells. These studies demonstrated that marginal mass of transplanted islets was sufficient to restore euglycemia in streptozotocin-treated rats. These superior results were obtained despite use of an impure preparation of islets in animals with small intestinal segment. Our findings will help advance new horizons for cell therapy in patients with diabetes.
Subject(s)
Diabetes Mellitus, Experimental/prevention & control , Graft Survival/physiology , Intestine, Small/surgery , Islets of Langerhans Transplantation , Islets of Langerhans/metabolism , Portal Vein/surgery , Animals , Diabetes Mellitus, Experimental/metabolism , Intestine, Small/blood supply , Intestine, Small/metabolism , Islets of Langerhans/blood supply , Islets of Langerhans/surgery , Portal Vein/metabolism , RNA, Messenger/genetics , Rats , Rats, Inbred Lew , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , Transplantation, IsogeneicABSTRACT
Type 1, or insulin-dependent diabetes mellitus (IDDM) is an autoimmune disease associated with loss of tolerance to several pancreatic islet cell molecules, including insulin, glutamic acid decarboxylase (GAD), ICA69 and the tyrosine phosphatase IA-2 (refs 1-3). Among several predisposing loci, IDDM2 maps to the insulin gene (INS) VNTR (variable number of tandem repeats) minisatellite on chromosome 11p15 (refs 4-9). Allelic variation at this VNTR locus correlates with steady-state levels of INS mRNA in pancreas and transfected rodent cell lines, but it is difficult to reconcile the association of lower INS mRNA levels in the pancreas with class III VNTRs that are dominantly protective from IDDM. We show that during fetal development and childhood, mRNAs for insulin and other islet cell autoantigens (GAD, ICA69, IA-2) are expressed at low levels in the human thymus. Critically, we also detect proinsulin and insulin protein. VNTR alleles correlate with differential INS mRNA expression in the thymus where, in contrast to the pancreas, protective class III VNTRs are associated with higher steady-state levels of INS mRNA expression. This finding provides a plausible explanation for the dominant protective effect of class III VNTRs, and suggests that diabetes susceptibility and resistance associated with IDDM2 may derive from the VNTR influence on INS transcription in the thymus. Higher levels of (pro)insulin in the thymus may promote negative selection (deletion) of insulin-specific T-lymphocytes which play a critical role in the pathogenesis of type-1 diabetes.
Subject(s)
Chromosomes, Human, Pair 11 , Diabetes Mellitus, Type 1/genetics , Gene Expression Regulation, Developmental , Insulin/biosynthesis , Insulin/genetics , Minisatellite Repeats , Thymus Gland/metabolism , Transcription, Genetic , Aging , Alleles , Child , Child, Preschool , Chromosome Mapping , DNA Primers , Disease Susceptibility , Embryonic and Fetal Development , Genetic Variation , Humans , Infant , Infant, Newborn , Organ Specificity , Polymerase Chain Reaction , Proinsulin/biosynthesis , RNA, Messenger/biosynthesis , Thymus Gland/embryology , Thymus Gland/growth & developmentABSTRACT
Inflammatory bowel disease (IBD) is defined as a relapsing and remitting condition characterized by chronic inflammation at different sites in the gastrointestinal tract. Crohn's disease (CD) and ulcerative colitis (UC) represents the two major forms of IBD. Even though IBD pathophysiology is still not fully understood, genetic factors, environmental factors, dysregulation of both innate and adaptive immune responses, alterations in gut microbiota composition, excessive consumption of saturated fats and cumulative antibiotic exposure have all been suggested to play a role in the development of this condition. Amongst the environmental factors, vitamin D deficiency has been suggested to participate in IBD pathophysiology. Indeed, vitamin D exerts several pleiotropic effects beyond its well-established regulation of bone and calcium homeostasis, including anti-infective, anti-inflammatory and immunomodulatory effects as well as maintenance of gastrointestinal barrier integrity and beneficial gut microbiota composition. In this narrative review, we discuss the role of vitamin D deficiency in IBD pathophysiology as well as the potential therapeutic use of vitamin D for the management of IBD.
Subject(s)
Colitis, Ulcerative , Crohn Disease , Inflammatory Bowel Diseases , Vitamin D Deficiency , Humans , Vitamin D/therapeutic use , Inflammatory Bowel Diseases/drug therapy , Crohn Disease/drug therapy , Colitis, Ulcerative/drug therapy , Vitamin D Deficiency/drug therapy , Vitamins/therapeutic useABSTRACT
Omega-3 polyunsaturated fatty acids (PUFA) have demonstrated anti-inflammatory properties, while Omega-6 have pro-inflammatory effects, and the balance between the two is an important aspect of healthy nutrition. Over the last 30 years, however, the Western diet has shifted largely from Omega-3 to Omega-6 consumption. Uncontrolled aberrant and chronic inflammation is a leading component of many common diseases, including arthritis, cardiovascular diseases, neurodegenerative diseases, cancer, obesity, autoimmune diseases, and infective diseases. Eicosanoids derived from Omega-6 participate in the inflammatory process, while Omega-3 PUFA have the opposite effect. Many favorable effects of Omega-3 are believed to result from their anti-inflammatory properties, but eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) also have inhibitory effects on immune cells and reduce proinflammatory cytokine release. All these mechanisms can be beneficial in autoimmunity. No effective preventions or definite cures for autoimmune diseases are yet known because pathophysiology is also unclear. Omega-3 fatty acid supplementation is associated with a significant reduction in disease activity in several autoimmune diseases, like type 1 diabetes (T1D), rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and multiple sclerosis (MS). Studies of viral diseases, including COVID-19, show improvement in symptom severity, recovery prognosis, and probability of survival with the use of Omega-3. Finally, the evidence of the beneficial effect of Omega-3 on metabolic diseases associated with aging is persuasive; various studies have demonstrated that their consumption improves lipids, fatty liver disease, obesity, cognitive function, and cardiovascular complications of chronic kidney disease (CKD). Omega-3 PUFA have also been shown to support an anti-inflammatory effect in older age and to have favorable effects on age-related disease's complications, frailty, and mortality. A healthy Omega-6/3 PUFA ratio should be targeted for the modulation of low-grade inflammation, as well as for the prevention of immune dysregulation and complications of uncontrolled inflammation triggered by infections, development, and progression of autoimmune disorders, and the consequences of oxidative stress due to aging. There is still a need for randomized clinical studies to validate current evidence supporting supplementation with correct doses of Omega-3 PUFA in autoimmune and chronic disease prevention.
Subject(s)
Autoimmune Diseases , COVID-19 , Fatty Acids, Omega-3 , Humans , Autoimmune Diseases/drug therapy , Disease Progression , Fatty Acids, Omega-3/pharmacology , Inflammation/drug therapyABSTRACT
AIMS/HYPOTHESIS: Low serum 25-hydroxyvitamin D [25(OH)D] concentration may increase risk of insulin-requiring diabetes. METHODS: A nested case-control study was performed using serum collected during 2002-2008 from military service members. One thousand subjects subsequently developed insulin-requiring diabetes. A healthy control was individually matched to each case on blood-draw date (±2 days), age (±3 months), length of service (±30 days) and sex. The median elapsed time between serum collection and first diagnosis of diabetes was 1 year (range 1 month to 10 years). Statistical analysis used matched pairs and conditional logistic regression. RESULTS: ORs for insulin-requiring diabetes by quintile of serum 25(OH)D, from lowest to highest, were 3.5 (95% CI 2.0, 6.0), 2.5 (1.5, 4.2), 0.8 (0.4, 1.4), 1.1 (0.6, 2.8) and 1.0 (reference) (p (trend) <0.001). The quintiles (based on fifths using serum 25(OH)D concentration in the controls) of serum 25(OH)D in nmol/l, were <43 (median 28), 43-59 (median 52), 60-77 (median 70), 78-99 (median 88) and ≥100 (median 128). CONCLUSIONS/INTERPRETATION: Individuals with lower serum 25(OH)D concentrations had higher risk of insulin-requiring diabetes than those with higher concentrations. A 3.5-fold lower risk was associated with a serum 25(OH)D concentration ≥60 nmol/l.
Subject(s)
Diabetes Mellitus, Type 1/diagnosis , Hypoglycemic Agents/administration & dosage , Insulin/administration & dosage , Vitamin D Deficiency/diagnosis , Vitamin D/analogs & derivatives , Adolescent , Adult , Case-Control Studies , Diabetes Mellitus, Type 1/blood , Diabetes Mellitus, Type 1/drug therapy , Diabetes Mellitus, Type 1/epidemiology , Dietary Supplements , Dose-Response Relationship, Drug , Female , Humans , Incidence , Male , Risk Assessment , Risk Factors , United States/epidemiology , Vitamin D/blood , Vitamin D Deficiency/blood , Vitamin D Deficiency/complicationsABSTRACT
The objective of this study was to identify predictors of insulin independence and to establish the best clinical tools to follow patients after pancreatic islet transplantation (PIT). Sequential metabolic responses to intravenous (I.V.) glucose (I.V. glucose tolerance test [IVGTT]), arginine and glucose-potentiated arginine (glucose-potentiated arginine-induced insulin secretion [GPAIS]) were obtained from 30 patients. We determined the correlation between transplanted islet mass and islet engraftment and tested the ability of each assay to predict return to exogenous insulin therapy. We found transplanted islet mass within an average of 16 709 islet equivalents per kg body weight (IEQ/kg BW; range between 6602 and 29 614 IEQ/kg BW) to be a poor predictor of insulin independence at 1 year, having a poor correlation between transplanted islet mass and islet engraftment. Acute insulin response to IVGTT (AIR(GLU) ) and GPAIS (AIR(max) ) were the most accurate methods to determine suboptimal islet mass engraftment. AIR(GLU) performed 3 months after transplant also proved to be a robust early metabolic marker to predict return to insulin therapy and its value was positively correlated with duration of insulin independence. In conclusion, AIR(GLU) is an early metabolic assay capable of anticipating loss of insulin independence at 1 year in T1D patients undergoing PIT and constitutes a valuable, simple and reliable method to follow patients after transplant.
Subject(s)
Biomarkers/blood , Diabetes Mellitus, Type 1/surgery , Graft Rejection/diagnosis , Graft Rejection/etiology , Islets of Langerhans Transplantation/adverse effects , Islets of Langerhans/pathology , Postoperative Complications , Adolescent , Adult , Aged , Blood Glucose/metabolism , C-Peptide/blood , C-Peptide/metabolism , Case-Control Studies , Female , Follow-Up Studies , Glucose Tolerance Test , Graft Rejection/blood , Humans , Insulin/blood , Insulin/metabolism , Insulin Secretion , Male , Middle Aged , Transplantation, Homologous , Young AdultABSTRACT
PURPOSE: Dyslipidemia is common in type 2 diabetes (T2D) and contributes to cardiovascular disease (CVD) by exacerbating atherosclerosis and hypercoagulability. Statins can stabilize atherosclerotic plaque and reduce prothrombotic status. In the present study we aimed to evaluate the coagulation activity and the effect of statins on procoagulant state of T2D patients using a novel activated protein C (APC)-dependent thrombin-generation assay. METHODS: Procoagulant status (by HemosIL ThromboPath (ThP) assay) and in vivo platelet activation (by plasma soluble (s)CD40L levels) were analyzed in a retrospective, cross-sectional study of 198 patients with long-standing T2D and 198 controls. RESULTS: Procoagulant status of T2D patients was enhanced when compared to control subjects (p < 0.0001). Similarly, sCD40L levels were increased in T2D (p < 0.0001). When testing ThP as the dependent variable in a multivariate regression model, sCD40L (p < 0.0001) and statin treatment (p = 0.019) were independent predictors of the procoagulant state of T2D patients. Subgroup analysis showed a significant improvement of coagulability in T2D patients on statins (p = 0.012). CONCLUSIONS: The use of a standardized, easy-to-run, and commercially available APC-dependent thrombin-generation assay detected the presence of a procoagulant status in a large series of patients with long-standing T2D and demonstrated a significant impact of statins in the coagulation status of patients with T2D.
Subject(s)
Blood Coagulation/drug effects , Diabetes Mellitus, Type 2/blood , Hydroxymethylglutaryl-CoA Reductase Inhibitors/pharmacology , Thrombin/chemistry , Aged , CD40 Ligand/blood , Cross-Sectional Studies , Diabetes Mellitus, Type 2/metabolism , Female , Humans , Male , Platelet Activation/drug effects , Protein C/metabolism , Retrospective StudiesABSTRACT
Obesity, metabolic syndrome and diabetes represent multi-factorial conditions resulting from improper balances of hormones and gene expression. In addition, these conditions have a strong inflammatory component that can potentially be impacted by the diet. The purpose of this review is to discuss the molecular targets that can be addressed by anti-inflammatory nutrition. These molecular targets range from reduction of pro-inflammatory eicosanoids that can alter hormonal signaling cascades to the modulation of the innate immune system, via toll-like receptors and gene transcription factors. Working knowledge of the impact of nutrients, especially dietary fatty acids and polyphenols, on these various molecular targets makes it possible to develop a general outline of an anti-inflammatory diet that offers a unique, non-pharmacological approach for treating obesity, metabolic syndrome and diabetes.
Subject(s)
Diabetes Mellitus/prevention & control , Fatty Acids/administration & dosage , Inflammation/prevention & control , Metabolic Syndrome/prevention & control , Obesity/prevention & control , Polyphenols/administration & dosage , Transcription, Genetic , Adipocytes/physiology , Arachidonic Acid/biosynthesis , Humans , Immunity, Innate , Inflammation/geneticsABSTRACT
As part of our ongoing effort to develop biohybrid devices for pancreatic islet transplantation, we are interested in establishing the feasibility of a localized immune-suppressive approach to avoid or minimize the undesirable side effects of existing systemic treatments. Since biohybrid devices can also incorporate biocompatible scaffold constructs to provide a support environment for the transplanted cells that enhances their engraftment and long-term function, we are particularly interested in an approach that would use the same three-dimensional construct, or part of the same construct, to also provide sustained release of therapeutic agents to modulate the inflammatory and immune responses locally. Within this framework, here, we report preliminary results obtained during the investigation of the suitability of organosilicone constructs for providing sustained localized drug release using small, matrix-type polydimethylsiloxane (PDMS) disks and dexamethasone as a model hydrophobic drug. Following a short burst, long-term steady sustained release was observed under in vitro conditions at levels of 0.1-0.5 microg/day/disk with a profile in excellent agreement with that predicted by the Higuchi equation. To verify that therapeutic levels can be achieved, suppression of LPS-induced activation has been shown in THP-1 cells with disks that have been pre-soaked for up to 28 days. These preliminary results prove the feasibility of this approach where an integral part of the biomaterial construct used to enhance cell engraftment and long-term function also serves to provide sustained local drug release.
Subject(s)
Anti-Inflammatory Agents/pharmacology , Cell Transplantation/physiology , Dexamethasone/pharmacology , Immunosuppression Therapy/methods , Silicones/pharmacology , Transplantation Immunology/drug effects , Algorithms , Cell Line, Tumor , Delayed-Action Preparations , Diabetes Mellitus, Type 1/therapy , Dimethylpolysiloxanes , Drug Delivery Systems , Excipients , Humans , Lipopolysaccharides/pharmacology , SolubilityABSTRACT
The large, randomized, double-blind, placebo-controlled trial VITAL (Vitamin D and omega 3 trial) recently confirmed that vitamin D and omega-3 polyunsaturated fatty acid (PUFA) co-supplementation (VIDOM) can reduce the incidence of autoimmune diseases. Based on these relevant results, this commentary summarizes the molecular mechanisms behind the anti-inflammatory and immunomodulatory properties of vitamin D and omega-3 PUFAs. We also describe the potential bidirectional interplay between vitamin D metabolism and omega-3 PUFA metabolism that underlies the rationale for VIDOM co-supplementation and that may contribute to enhance the anti-inflammatory and immunomodulatory actions of vitamin D and omega-3 PUFAs when these compounds are administered in combination.
Subject(s)
Autoimmune Diseases , Fatty Acids, Omega-3 , Anti-Inflammatory Agents , Autoimmune Diseases/drug therapy , Autoimmunity , Dietary Supplements , Double-Blind Method , Fatty Acids, Omega-3/pharmacology , Humans , Immunomodulation , Randomized Controlled Trials as Topic , Vitamin D , VitaminsABSTRACT
AIMS/HYPOTHESIS: The aim of this study was to provide evidence that the anterior chamber of the eye serves as a novel clinical islet implantation site. METHODS: In a preclinical model, allogeneic pancreatic islets were transplanted into the anterior chamber of the eye of a baboon model for diabetes, and metabolic and ophthalmological outcomes were assessed. RESULTS: Islets readily engrafted on the iris and there was a decrease in exogenous insulin requirements due to insulin secretion from the intraocular grafts. No major adverse effects on eye structure and function could be observed during the transplantation period. CONCLUSIONS/INTERPRETATION: Our study demonstrates the long-term survival and function of allogeneic islets after transplantation into the anterior chamber of the eye. The safety and simplicity of this procedure provides support for further studies aimed at translating this technology into the clinic.
Subject(s)
Anterior Chamber/surgery , Diabetes Mellitus, Experimental/therapy , Islets of Langerhans Transplantation/methods , Animals , PapioABSTRACT
OBJECTIVE: We aimed at explaining the mechanism of therapeutic effect of Umbilical Cord Mesenchymal Stem Cells (UC-MSC) in subjects with COVID-19 Acute Respiratory Distress Syndrome (ARDS). Patients with COVID-19 ARDS present with a hyperinflammatory response characterized by high levels of circulating pro-inflammatory mediators, including tumor necrosis factor α and ß (TNFα and TNFß). Inflammatory functions of these TNFs can be inhibited by soluble TNF Receptor 2 (sTNFR2). In patients with COVID-19 ARDS, UC-MSC appear to impart a robust anti-inflammatory effect, and treatment is associated with remarkable clinical improvements. We investigated the levels of TNFα, TNFß and sTNFR2 in blood plasma samples collected from subjects with COVID-19 ARDS enrolled in our trial of UC-MSC treatment. PATIENTS AND METHODS: We analyzed plasma samples from subjects with COVID-19 ARDS (n=24) enrolled in a Phase 1/2a randomized controlled trial of UC-MSC treatment. Plasma samples were obtained at Day 0 (baseline, before UC-MSC or control infusion), and Day 6 post infusion. Plasma concentrations of sTNFR2, TNFα, and TNFß were evaluated using a quantitative multiplex protein array. RESULTS: Our data indicate that at Day 6 after infusion, UC-MSC recipients develop significantly increased levels of plasma sTNFR2 and significantly decreased levels of TNFα and TNFß, compared to controls. CONCLUSIONS: These observations suggest that sTNFR2 plays a mechanistic role in mediating UC-MSC effect on TNFα and TNFß plasma levels, determining a decrease in inflammation in COVID-19 ARDS.
Subject(s)
COVID-19/blood , Lymphotoxin-alpha/blood , Mesenchymal Stem Cell Transplantation/methods , Receptors, Tumor Necrosis Factor, Type II/blood , Respiratory Distress Syndrome/blood , Tumor Necrosis Factor-alpha/blood , Umbilical Cord/transplantation , Biomarkers/blood , COVID-19/therapy , Double-Blind Method , Humans , Respiratory Distress Syndrome/therapy , Umbilical Cord/cytologyABSTRACT
AIMS: Pancreatic islet transplantation (PIT) represents a potential curative treatment for patients with type 1 diabetes, but only 10-15% of patients remain insulin independent 5 years post-transplant. It is not known whether intrinsic insulin resistance exacerbated by immunosuppression plays a pivotal role in low graft survival. The study objective was to understand the changes in insulin resistance, glucose effectiveness (S(g)) and free fatty acid dynamics (FFAd) before and after PIT. METHODS: Insulin sensitivity index (S(i)), S(g) and FFAd were measured before and after PIT in 10 lean patients, 8 of whom reached insulin independence. Modified Bergman minimal model of frequently sampled intravenous glucose tolerance tests were performed pretransplant and at 12 months post-transplant. Nine non-diabetic control (NDC) subjects matched by age, gender and BMI were used. RESULTS: Pretransplant S(i) and S(g) were 3.5 ± 0.8 × 10(-5)/min/(pmol/l) and 0.74 ± 0.24 × 10(-2)/min, respectively. S(i) was significantly lower than matched NDCs [10.8 ± 0.6 × 10(-5)/min/(pmol/l), p < 0.004]; S(g) did not reach statistical significance (1.27 ± 0.22 × 10(-2)/min, p = 0.25). Compared to pretransplant values, mean post-transplant S(i) and S(g) were 9.6 ± 1.3 × 10(-5)/min/(pmol/l)and 1.28 ± 0.22 ×10(-2)/min, respectively, indicating significant improvement for S(i) but not S(g) (p = 0.008 and p = 0.06). Twelve-month post-PIT compared to NDC values were not significantly different (p = 0.58 and 0.97, respectively). In addition, fractional disposal rate for FFA which directly depends on the endogenous insulin release (10-20 min) nearly normalized after PIT (p = 0.06). CONCLUSION: These preliminary findings demonstrate that PIT can restore glucose disposal and insulin sensitivity and partially correct glucose effectiveness and FFAd.
Subject(s)
Diabetes Mellitus, Type 1/physiopathology , Fatty Acids, Nonesterified/physiology , Glucose/metabolism , Insulin Resistance/physiology , Insulin/physiology , Islets of Langerhans Transplantation , Adolescent , Adult , Aged , Diabetes Mellitus, Type 1/surgery , Female , Glucose Tolerance Test , Humans , Insulin/metabolism , Insulin Secretion , Islets of Langerhans Transplantation/methods , Male , Middle Aged , Treatment Outcome , Young AdultABSTRACT
BACKGROUND: Quantification of islet mass is a crucial criterion for defining the quality of the islet product ensuring a potent islet transplant when used as a therapeutic intervention for select patients with type I diabetes. METHODS: This multi-center study involved all eight member institutions of the National Institutes of Health-supported Islet Cell Resources Consortium. The study was designed to validate the standard counting procedure for quantifying isolated, dithizone-stained human islets as a reliable methodology by ascertaining the accuracy, repeatability (intra-observer variability), and intermediate precision (inter-observer variability). The secondary aim of the study was to evaluate a new software-assisted digital image analysis method as a supplement for islet quantification. RESULTS: The study demonstrated the accuracy, repeatability and intermediate precision of the standard counting procedure for isolated human islets. This study also demonstrated that software-assisted digital image analysis as a supplemental method for islet quantification was more accurate and consistent than the standard manual counting method. CONCLUSIONS: Standard counting procedures for enumerating isolated stained human islets is a valid methodology, but computer-assisted digital image analysis assessment of islet mass has the added benefit of providing a permanent record of the isolated islet product being evaluated that improves quality assurance operations of current good manufacturing practice.
Subject(s)
Image Processing, Computer-Assisted/methods , Islets of Langerhans Transplantation , Islets of Langerhans/cytology , Cell Separation/methods , Cell Size , Delphi Technique , Flow Cytometry , Humans , Islets of Langerhans Transplantation/methods , Reproducibility of ResultsABSTRACT
Emerging biotechnologies, such as the use of biohybrid devices for cellular therapies, are showing increasing therapeutic promise for the treatment of various diseases, including type 1 diabetes mellitus. The functionality of such devices could be greatly enhanced if successful localized immunosuppression regimens could be established, since they would eliminate the many otherwise unavoidable side effects of currently used systemic immunosuppressive therapies. The existence of local immune privilege at some specialized tissues, such as the eye, CNS, or pregnant uterus, supports the feasibility of localized immunomodulation, and such an approach is particularly well-suited for cell transplant therapies where all transplanted tissue is localized within a device. Following the success of syngeneic transplantation in a subcutaneous prevascularized device as a bioartificial pancreas in a rodent model, we now report the first results of exploratory in vivo islet allograft studies in rats using locally delivered glucocorticoids (dexamethasone phosphate and the soft steroid loteprednol etabonate). Following in vitro assessments, in silico drug distribution models were used to establish tentative therapeutic dose ranges. Sustained local delivery was achieved via implantable osmotic mini-pumps through a central sprinkler, as well as with a sustained-delivery formulation for loteprednol etabonate using poly(D,L-lactic) acid (PLA) microspheres. Doses delivered locally were approximately hundred-fold smaller than those typically used in systemic treatments. While several solubility, stability, and implantation problems still remain to be addressed, both compounds showed promise in their ability to prolong graft survival after tapering of systemic immunosuppression, compared to control groups.
Subject(s)
Cell Transplantation/instrumentation , Glucocorticoids/pharmacology , Immunosuppressive Agents , Islets of Langerhans Transplantation/immunology , Algorithms , Androstadienes/administration & dosage , Animals , Biotechnology , Computer Simulation , Delayed-Action Preparations , Drug Delivery Systems , Drug Implants , Feasibility Studies , Female , Glucocorticoids/administration & dosage , Glucocorticoids/adverse effects , Humans , Immunosuppressive Agents/adverse effects , Kaplan-Meier Estimate , Lactic Acid , Loteprednol Etabonate , Microspheres , Polyglycolic Acid , Polylactic Acid-Polyglycolic Acid Copolymer , Pregnancy , Rats , Tissue DistributionABSTRACT
OBJECTIVE: Our goal was to assess the efficacy of encapsulated allogeneic islets transplanted in diabetic NOD mice and streptozotocin (STZ)-diabetic nonhuman primates (NHPs). MATERIALS AND METHODS: Murine or NHP islets were microencapsulated and transplanted in non-immunosuppressed mice or NHPs given clinically-acceptable immunosuppressive regimens, respectively. Two NHPs were treated with autologous mesenchymal stem cells (MSCs) and peri-transplant oxygen therapy. Different transplant sites (intraperitoneal [i.p.], omental pouch, omental surface, and bursa omentalis) were tested in separate NHPs. Graft function was monitored by exogenous insulin requirements, fasting blood glucose levels, glucose tolerance tests, percent hemoglobin A1c (% HbA1c), and C-peptide levels. In vitro assessment of grafts included histology, immunohistochemistry, and viability staining; host immune responses were characterized by flow cytometry and cytokine/chemokine multiplex ELISAS. RESULTS: Microencapsulated islet allografts functioned long-term i.p. in diabetic NOD mice without immunosuppression, but for a relatively short time in immunosuppressed NHPs. In the NHPs, encapsulated allo-islets initially reduced hyperglycemia, decreased exogenous insulin requirements, elevated C-peptide levels, and lowered % HbA1c in plasma, but graft function diminished with time, regardless of transplant site. At necropsy, microcapsules were intact and non-fibrotic, but many islets exhibited volume loss, central necrosis and endogenous markers of hypoxia. Animals receiving supplemental oxygen and autologous MSCs showed improved graft function for a longer post-transplant period. In diabetic NHPs and mice, cell-free microcapsules did not elicit a fibrotic response. CONCLUSIONS: The evidence suggested that hypoxia was a major factor for damage to encapsulated islets in vivo. To achieve long-term function, new approaches must be developed to increase the oxygen supply to microencapsulated islets and/or identify donor insulin-secreting cells which can tolerate hypoxia.
Subject(s)
Allografts , Diabetes Mellitus, Experimental/therapy , Islets of Langerhans Transplantation , Animals , Capsules/chemistry , Mice , Mice, Inbred NODABSTRACT
The coronavirus SARS-CoV-2 is cause of a global pandemic of a pneumonia-like disease termed Coronavirus Disease 2019 (COVID-19). COVID-19 presents a high mortality rate, estimated at 3.4%. More than 1 out of 4 hospitalized COVID-19 patients require admission to an Intensive Care Unit (ICU) for respiratory support, and a large proportion of these ICU-COVID-19 patients, between 17% and 46%, have died. In these patients COVID-19 infection causes an inflammatory response in the lungs that can progress to inflammation with cytokine storm, Acute Lung Injury (ALI), Acute Respiratory Distress Syndrome (ARDS), thromboembolic events, disseminated intravascular coagulation, organ failure, and death. Mesenchymal Stem Cells (MSCs) are potent immunomodulatory cells that recognize sites of injury, limit effector T cell reactions, and positively modulate regulatory cell populations. MSCs also stimulate local tissue regeneration via paracrine effects inducing angiogenic, anti-fibrotic and remodeling responses. MSCs can be derived in large number from the Umbilical Cord (UC). UC-MSCs, utilized in the allogeneic setting, have demonstrated safety and efficacy in clinical trials for a number of disease conditions including inflammatory and immune-based diseases. UC-MSCs have been shown to inhibit inflammation and fibrosis in the lungs and have been utilized to treat patients with severe COVID-19 in pilot, uncontrolled clinical trials, that reported promising results. UC-MSCs processed at our facility have been authorized by the FDA for clinical trials in patients with an Alzheimer's Disease, and in patients with Type 1 Diabetes (T1D). We hypothesize that UC-MSC will also exert beneficial therapeutic effects in COVID-19 patients with cytokine storm and ARDS. We propose an early phase controlled, randomized clinical trial in COVID-19 patients with ALI/ARDS. Subjects in the treatment group will be treated with two doses of UC-MSC (l00 × 106 cells). The first dose will be infused within 24 hours following study enrollment. A second dose will be administered 72 ± 6 hours after the first infusion. Subject in the control group will receive infusion of vehicle (DPBS supplemented with 1% HSA and 70 U/kg unfractionated Heparin, delivered IV) following the same timeline. Subjects will be evaluated daily during the first 6 days, then at 14, 28, 60, and 90 days following enrollment (see Schedule of Assessment for time window details). Safety will be determined by adverse events (AEs) and serious adverse events (SAEs) during the follow-up period. Efficacy will be defined by clinical outcomes, as well as a variety of pulmonary, biochemical and immunological tests. Success of the current study will provide a framework for larger controlled, randomized clinical trials and a means of accelerating a possible solution for this urgent but unmet medical need. The proposed early phase clinical trial will be performed at the University of Miami (UM), in the facilities of the Diabetes Research Institute (DRI), UHealth Intensive Care Unit (ICU) and the Clinical Translational Research Site (CTRS) at the University of Miami Miller School of Medicine and at the Jackson Memorial Hospital (JMH).
ABSTRACT
AIMS/HYPOTHESIS: The aim of the study was to determine age- and race-related, and overall incidence rates of insulin-requiring diabetes in adults in the US military. METHODS: Electronic records for admissions to US military and Tricare hospitals during 1990-2005 and visits to military clinics during 2000-2005 were identified using the Career History Archival Medical and Personnel System at the Naval Health Research Center, San Diego, CA, USA. Population data were obtained from the Defense Manpower Data Center and Defense Medical Epidemiology Database. RESULTS: In men there were 2,918 new cases of insulin-requiring diabetes in 20,427,038 person-years at ages 18-44 years (median age 28 years) for a total age-adjusted incidence rate of 17.5 per 100,000 person-years (95% CI 16.4-18.6). Incidence rates were twice as high in black men as in white men (31.5 vs 14.5 per 100,000, p < 0.001). In women there were 414 new cases in 3,285,000 person-years at ages 18-44 years (median age 27 years), for a total age-adjusted incidence rate of 13.6 per 100,000 (95% CI 12.4-14.9). Incidence rates were twice as high in black women as in white women (21.8 vs 9.7 per 100,000, p < 0.001). In a regression model, incidence of insulin-requiring diabetes peaked annually in the winter-spring season (OR 1.46, p < 0.01). Race and seasonal differences persisted in the multivariate analysis. CONCLUSIONS/INTERPRETATION: Differences in incidence rates by race and season suggest a need for further research into possible reasons, including the possibility of a contribution from vitamin D deficiency. Cohort studies using prediagnostic serum 25-hydroxyvitamin D should be conducted to further evaluate this relationship.
Subject(s)
Diabetes Mellitus/drug therapy , Diabetes Mellitus/epidemiology , Hypoglycemic Agents/therapeutic use , Insulin/therapeutic use , Military Personnel , Adult , Age Factors , Black People , Diabetes Mellitus/ethnology , Female , Humans , Male , Sex Factors , United States , White People , Young AdultABSTRACT
The aim of this study was to test whether an omental pouch can be used as an alternative site for islet implantation in diabetic monkeys. Here we report the successful engraftment of islets in diabetic cynomolgus monkeys when loaded on a synthetic biodegradable scaffold and placed in an omental pouch. One autologous and five allogeneic diabetic monkey transplants under the cover of steroid-free immune suppression (SFIS) were undertaken. Fasting blood glucose (FBG) and C-peptide (CP), exogenous insulin requirements (EIR), intravenous glucose tolerance test (IVGTT), A1C and histopathology were used to assess islet engraftment and survival. All animals achieved CP levels > 1.0 ng/mL following transplant, a 66-92% posttransplant decrease in EIR and reduced A1C. Following graft removal, CP became negative and histopathological analysis of the explanted grafts demonstrated well-granulated and well-vascularized, insulin-positive islets, surrounded by T-cell subsets and macrophages. Compared to intrahepatic allogeneic islet transplants (n = 20), there was a delayed engraftment for omental pouch recipients but similar levels of CP production were ultimately achieved, with a broad range of IEQ/kg transplanted in both sites. Our results suggest this extrahepatic transplantation site has potential as an alternative site for clinical islet cell transplantation.