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32,857 result(s) for "Islet"
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Insulin-producing organoids engineered from islet and amniotic epithelial cells to treat diabetes
Maintaining long-term euglycemia after intraportal islet transplantation is hampered by the considerable islet loss in the peri-transplant period attributed to inflammation, ischemia and poor angiogenesis. Here, we show that viable and functional islet organoids can be successfully generated from dissociated islet cells (ICs) and human amniotic epithelial cells (hAECs). Incorporation of hAECs into islet organoids markedly enhances engraftment, viability and graft function in a mouse type 1 diabetes model. Our results demonstrate that the integration of hAECs into islet cell organoids has great potential in the development of cell-based therapies for type 1 diabetes. Engineering of functional mini-organs using this strategy will allow the exploration of more favorable implantation sites, and can be expanded to unlimited (stem-cell-derived or xenogeneic) sources of insulin-producing cells. Islet transplantation is a feasible approach to treat type I diabetes, however inflammation and poor vascularisation impair long-term engraftment. Here the authors show that incorporating human amniotic epithelial cells into islet organoids improves engraftment and function of organoids, through enhanced revascularisation.
Safety, tolerability, pharmacokinetics, and pharmacodynamics of concomitant administration of multiple doses of cagrilintide with semaglutide 2·4 mg for weight management: a randomised, controlled, phase 1b trial
Cagrilintide, a long-acting amylin analogue, and semaglutide 2·4 mg, a glucagon-like peptide-1 analogue, are both being investigated as options for weight management. We aimed to determine the safety, tolerability, pharmacokinetics, and pharmacodynamics of this drug combination. In this randomised, placebo-controlled, multiple-ascending dose, phase 1b trial, individuals aged 18–55 years with a body-mass index 27·0−39·9 kg/m2 and who were otherwise healthy were recruited from a single centre in the USA. The trial included six sequential overlapping cohorts, and in each cohort eligible participants were randomly assigned (3:1) to once-weekly subcutaneous cagrilintide (0·16, 0·30, 0·60, 1·2, 2·4, or 4·5 mg) or matched placebo, in combination with once-weekly subcutaneous semaglutide 2·4 mg, without lifestyle interventions. In each cohort, the doses of cagrilintide and semaglutide were co-escalated in 4-week intervals to the desired dose over 16 weeks, participants were treated at the target dose for 4 weeks, and then followed up for 5 weeks. Participants, investigators, and the sponsor were masked to treatment assignment. The primary endpoint was number of treatment-emergent adverse events from baseline to end of follow-up. Secondary pharmacokinetic endpoints assessed from day of last dose (week 19) to end of treatment (week 20) were area under the plasma concentration-time curve from 0 to 168 h (AUC0–168 h) and maximum concentration [Cmax] of cagrilintide and semaglutide; exploratory pharmacokinetic endpoints were half-life, time to Cmax [tmax], plasma clearance, and volume of distribution of cagrilintide and semaglutide; and exploratory pharmacodynamic endpoints were changes in bodyweight, glycaemic parameters, and hormones. Safety, pharmacokinetic, and pharmacodynamic endpoints were assessed in all participants who were exposed to at least one dose of study drug. This study is registered with ClinicalTrials.gov, NCT03600480, and is now complete. Between July 25, 2018, and Dec 17, 2019, 285 individuals were screened and 96 were randomly assigned to cagrilintide (0·16–2·4 mg group n=12; 4·5 mg group n=11) or placebo (n=24), in combination with semaglutide 2·4 mg, of whom 95 were exposed to treatment (one patient in 0·60 mg cagrilintide group was not exposed) and included in the safety and full analysis datasets. The mean age was 40·6 years (SD 9·2), 56 (59%) of 95 participants were men and 51 (54%) were Black or African American. Of 566 adverse events reported in 92 participants (69 [97%] of 71 participants assigned to 0·16–4·5 mg cagrilintide and 23 [96%] of 24 assigned to placebo), 207 (37%) were gastrointestinal disorders. Most adverse events were mild to moderate in severity and the proportion of participants with one or more adverse event was similar across treatment groups. Exposure was proportional to cagrilintide dose and did not affect semaglutide exposure or elimination. AUC0–168 h ranged from 926 nmol × h/L to 24 271 nmol × h/L, and Cmax ranged from 6·14 nmol/L to 170 nmol/L with cagrilintide 0·16–4·5 mg. AUC0–168 h ranged from 12 757 nmol × h/L to 15 305 nmol × h/L, and Cmax ranged from 96·4 nmol/L to 120 nmol/L with semaglutide 2·4 mg. Cagrilintide 0·16−4·5 mg had a half-life of 159–195 h, with a median tmax of 24–72 h. Semaglutide 2·4 mg had a half-life of 145–165 h, with a median tmax of 12–24 h. Plasma clearance and volume of distribution for both cagrilintide and semaglutide were similar across treatment groups. At week 20, mean percentage bodyweight reductions were greater with cagrilintide 1·2 and 2·4 mg than with placebo (15·7% [SE 1·6] for cagrilintide 1·2 mg and 17·1% [1·5] for cagrilintide 2·4 mg vs 9·8% [1·2] for pooled placebo cohorts 1–5; estimated treatment difference of −6·0% [95% CI −9·9 to −2·0] for cagrilintide 1·2 mg and −7·4% [−11·2 to −3·5] for cagrilintide 2·4 mg vs pooled placebo), and with cagrilintide 4·5 mg than with matched placebo (15·4% [1·3] vs 8·0% [2·2]; estimated treatment difference −7·4% [−12·8 to −2·1]), all in combination with semaglutide 2·4 mg. Glycaemic parameters improved in all treatment groups, independently of cagrilintide dose. Changes in hormones were similar across treatment groups. Concomitant treatment with cagrilintide and semaglutide 2·4 mg was well tolerated with an acceptable safety profile. Future larger and longer trials are needed to fully assess the efficacy and safety of this treatment combination. Novo Nordisk A/S.
Long-Term Metabolic and Immunological Follow-Up of Nonimmunosuppressed Patients With Type 1 Diabetes Treated With Microencapsulated Islet Allografts: Four cases
OBJECTIVE: To assess long-term metabolic and immunological follow-up of microencapsulated human islet allografts in nonimmunosuppressed patients with type 1 diabetes (T1DM). RESEARCH DESIGN AND METHODS: Four nonimmunosuppressed patients, with long-standing T1DM, received intraperitoneal transplant (TX) of microencapsulated human islets. Anti-major histocompatibility complex (MHC) class I–II, GAD65, and islet cell antibodies were measured before and long term after TX. RESULTS: All patients turned positive for serum C-peptide response, both in basal and after stimulation, throughout 3 years of posttransplant follow-up. Daily mean blood glucose, as well as HbA1c levels, significantly improved after TX, with daily exogenous insulin consumption declining in all cases and being discontinued, just transiently, only in patient 4. Anti-MHC class I–II and GAD65 antibodies all tested negative at 3 years after TX. CONCLUSIONS: The grafts did not elicit any immune response, even in the cases where more than one preparation was transplanted, as a unique finding, compatible with encapsulation-driven \"bioinvisibility\" of the grafted islets. This result had never been achieved with the recipient’s general immunosuppression.
Stem Cell–Derived, Fully Differentiated Islets for Type 1 Diabetes
Zimislecel is an allogeneic stem cell–derived islet-cell therapy. This phase 1–2 study supports the hypothesis that zimislecel can restore physiologic islet function and thus treat persons with type 1 diabetes.
CXCR1/2 inhibition enhances pancreatic islet survival after transplantation
Although long considered a promising treatment option for type 1 diabetes, pancreatic islet cell transformation has been hindered by immune system rejection of engrafted tissue. The identification of pathways that regulate post-transplant detrimental inflammatory events would improve management and outcome of transplanted patients. Here, we found that CXCR1/2 chemokine receptors and their ligands are crucial negative determinants for islet survival after transplantation. Pancreatic islets released abundant CXCR1/2 ligands (CXCL1 and CXCL8). Accordingly, intrahepatic CXCL1 and circulating CXCL1 and CXCL8 were strongly induced shortly after islet infusion. Genetic and pharmacological blockade of the CXCL1-CXCR1/2 axis in mice improved intrahepatic islet engraftment and reduced intrahepatic recruitment of polymorphonuclear leukocytes and NKT cells after islet infusion. In humans, the CXCR1/2 allosteric inhibitor reparixin improved outcome in a phase 2 randomized, open-label pilot study with a single infusion of allogeneic islets. These findings indicate that the CXCR1/2-mediated pathway is a regulator of islet damage and should be a target for intervention to improve the efficacy of transplantation.
Islet Harvest in Carbon Monoxide-Saturated Medium for Chronic Pancreatitis Patients Undergoing Islet Autotransplantation
Stresses encountered during human islet isolation lead to unavoidable β-cell death after transplantation. This reduces the chance of insulin independence in chronic pancreatitis patients undergoing total pancreatectomy and islet autotransplantation. We tested whether harvesting islets in carbon monoxide-saturated solutions is safe and can enhance islet survival and insulin independence after total pancreatectomy and islet autotransplantation. Chronic pancreatitis patients who consented to the study were randomized into carbon monoxide (islets harvested in a carbon monoxide-saturated medium) or control (islets harvested in a normal medium) groups. Islet yield, viability, oxygen consumption rate, β-cell death (measured by unmethylated insulin DNA), and serum cytokine levels were measured during the peri-transplantation period. Adverse events, metabolic phenotypes, and islet function were measured prior and at 6 months post-transplantation. No adverse events directly related to the infusion of carbon monoxide islets were observed. Carbon monoxide islets showed significantly higher viability before transplantation. Subjects receiving carbon monoxide islets had less β-cell death, decreased CCL23, and increased CXCL12 levels at 1 or 3 days post transplantation compared with controls. Three in 10 (30%) of the carbon monoxide subjects and none of the control subjects were insulin independent. This pilot trial showed for the first time that harvesting human islets in carbon monoxide-saturated solutions is safe for total pancreatectomy and islet autotransplantation patients.
Islet amyloid polypeptide aggregation exerts cytotoxic and proinflammatory effects on the islet vasculature in mice
Aims/hypothesisThe islet vasculature, including its constituent islet endothelial cells, is a key contributor to the microenvironment necessary for normal beta cell health and function. In type 2 diabetes, islet amyloid polypeptide (IAPP) aggregates, forming amyloid deposits that accumulate between beta cells and islet capillaries. This process is known to be toxic to beta cells but its impact on the islet vasculature has not previously been studied. Here, we report the first characterisation of the effects of IAPP aggregation on islet endothelial cells/capillaries using cell-based and animal models.MethodsPrimary and immortalised islet endothelial cells were treated with amyloidogenic human IAPP (hIAPP) alone or in the presence of the amyloid blocker Congo Red or the Toll-like receptor (TLR) 2/4 antagonist OxPAPc. Cell viability was determined0 along with mRNA and protein levels of inflammatory markers. Islet capillary abundance, morphology and pericyte coverage were determined in pancreases from transgenic mice with beta cell expression of hIAPP using conventional and confocal microscopy.ResultsAggregated hIAPP decreased endothelial cell viability in immortalised and primary islet endothelial cells (by 78% and 60%, respectively) and significantly increased expression of inflammatory markers Il6, Vcam1 and Edn1 mRNA relative to vehicle treatment in both cell types (p<0.05; n=4). Both cytotoxicity and the proinflammatory response were ameliorated by Congo Red (p<0.05; n=4); whereas TLR2/4-inhibition blocked inflammatory gene expression (p<0.05; n=6) without improving viability. Islets from high-fat-diet-fed amyloid-laden hIAPP transgenic mice also exhibited significantly increased expression of most markers of endothelial inflammation (p<0.05; n=5) along with decreased capillary density compared with non-transgenic littermates fed the same diet (p<0.01). Moreover, a 16% increase in capillary diameter was observed in amyloid-adjacent capillaries (p<0.01), accompanied by a doubling in pericyte structures positive for neuron-glial antigen 2 (p<0.001).Conclusions/interpretationIslet endothelial cells are susceptible to hIAPP-induced cytotoxicity and exhibit a TLR2/4-dependent proinflammatory response to aggregated hIAPP. Additionally, we observed amyloid-selective effects that decreased islet capillary density, accompanied by increased capillary diameter and increased pericyte number. Together, these data demonstrate that the islet vasculature is a target of the cytotoxic and proinflammatory effects of aggregated hIAPP that likely contribute to the detrimental effects of hIAPP aggregation on beta cell function and survival in type 2 diabetes.
Coadministered Cagrilintide and Semaglutide in Adults with Overweight or Obesity
In a phase 3a randomized trial, semaglutide at a dose of 2.4 mg with cagrilintide at a dose of 2.4 mg led to significant body-weight reduction in adults without diabetes and with overweight or obesity.
Amycretin, a novel, unimolecular GLP-1 and amylin receptor agonist administered subcutaneously: results from a phase 1b/2a randomised controlled study
Amycretin is a novel, unimolecular GLP-1 and amylin receptor agonist. The aim of this study was to investigate the safety, tolerability, pharmacokinetics, and effects on bodyweight of subcutaneous amycretin administered over a treatment period of up to 36 weeks in participants with overweight or obesity. In this randomised, placebo-controlled, phase 1b/2a study, we investigated the safety, tolerability, pharmacokinetics, and effects on bodyweight of subcutaneous injection of amycretin in participants aged 18–55 years with overweight or obesity (BMI 27·0–39·9 kg/m2). The study took place at a single clinical research centre in San Antonio, TX, USA. Participants were randomly allocated to receive amycretin or placebo, with participants and investigators masked to trial product allocation. There were five parts: Part A (single ascending dose); Part B (multiple ascending dose [MAD]—dose escalation), once-weekly amycretin escalated from 0·3 mg to 60 mg for a total treatment duration of 36 weeks; and Parts C, D, and E (MAD—dose response), once-weekly amycretin escalated from 0·3 mg up to maintenance doses of 20 mg for a total treatment duration of 36 weeks, 5 mg for a total of 28 weeks, or 1·25 mg for a total of 20 weeks (maintenance dose sustained for the last 12 weeks). The primary endpoint was the number of treatment-emergent adverse events measured from baseline to end of study (Parts A–E). Secondary endpoints were area under the plasma concentration–time curve, maximum plasma concentration, and relative change in bodyweight from baseline. The safety analysis set comprised all participants exposed to treatment, and the full analysis set comprised all randomly allocated participants. This study is registered with ClinicalTrials.gov, NCT06064006. Between Sept 15, 2023, and April 24, 2024, 125 participants were randomly allocated to amycretin (n=101) or placebo (n=24). Mean baseline bodyweight was 88·3–99·1 kg across Parts B–E. The most common treatment-emergent adverse events were gastrointestinal, and the majority were mild to moderate in severity and resolved by the end of the study. A large number of participants withdrew from the study, with a high proportion of discontinuations occurring due to reasons unrelated to treatment-emergent adverse events. Estimated mean bodyweight change from baseline was significantly (Parts A–D: p<0·0001; Part E: p=0·0003) higher with amycretin versus placebo in Part B (60 mg, –24·3% vs –1·1%; week 36), Part C (20 mg, –22·0% vs 1·9%; week 36), Part D (5 mg, –16·2% vs 2·3%; week 28), and Part E (1·25 mg, –9·7% vs 2·0%; week 20). In people with overweight or obesity, once-weekly subcutaneous amycretin up to 60 mg had a safety and tolerability profile consistent with GLP-1 and amylin agonists. Although a high frequency of gastrointestinal events was reported, rates were similar to those seen in early-phase studies of these molecules. These results support further investigation into the weight loss properties of amycretin. Novo Nordisk.
Shorter Digestion Times of Donor Islets Is Associated With Better Islet Graft Function After Islet Transplantation
Although islet transplantation is effective in reducing severe hypoglycemia events and controlling blood glucose in patients with type 1 diabetes, maintaining islet graft function long-term is a significant challenge. Islets from multiple donors are often needed to achieve insulin independence, and even then, islet function can decline over time when metabolic demand exceeds islet mass/insulin secretory capacity. We previously developed a method that calculated the islet graft function index (GFI) and a patient’s predicted insulin requirement (PIR) using mathematical nonlinear regression. Both PIR and GFI could be used by physicians as tools to monitor islet graft function and to guide supplementing the patient with exogenous insulin to prevent beta-cell exhaustion. This study investigates the factors relating to the islet preparation process, as well as donor and recipient characteristics, and assessed their associations with PIR and GFI after transplantation. The goal is to determine the most relevant factors that influence islet graft function after transplantation. We examined the effects of donor and recipient characteristics, and islet processing factors on posttransplanted PIR and GFI. The PIR and GFI at 3 months were calculated using patients’ baseline insulin intake, posttransplant 2-h postprandial blood glucose, and glucagon-stimulated C-peptide. Thirteen transplants that resulted in progressive decline in patients’ weekly averaged insulin intake over the initial weeks after transplant (assuming constant glucose level) with available 3-month PIR and GFI data were chosen for the investigation. Univariate analyses were performed to assess the effects of donor and recipient characteristics and islet processing factors on islet graft function as reflected by PIR and GFI. The PIR and GFI were treated as continuous response variables in separate linear regression models. Shorter digestion time of isolated donor islets were associated with lower PIR (P = 0.014) and a higher GFI (P = 0.027) after transplantation. Islet injury related to digestion enzyme exposure influenced islet function as estimated using PIR and GFI post-transplantation.