Precision medicine in neurodegeneration: the IHI-PROMINENT project.

Neurodegenerative diseases are one of the most important contributors to morbidity and mortality in the elderly. In Europe, over 14 million people are currently living with dementia, at a cost of over 400 billion EUR annually. Recent advances in diagnostics and approval for new pharmaceutical treatments for Alzheimer's disease (AD), the most common etiology of dementia, heralds the beginning of precision medicine in this field. However, their implementation will challenge an already over-burdened healthcare systems. There is a need for innovative digital solutions that can drive the related clinical pathways and optimize and personalize care delivery. Public-private partnerships are ideal vehicles to tackle these challenges. Here we describe the Innovative Health Initiative (IHI) public-private partnership project PROMINENT that has been initiated by connecting leading dementia researchers, medical professionals, dementia patients and their care partners with the latest innovative health technologies using a precision medicine based digital platform. The project builds upon the knowledge and already implemented digital tools from several collaborative initiatives that address new models for early detection, diagnosis, and monitoring of AD and other neurodegenerative disorders. The project aims to provide support to improvement efforts to each aspect of the care pathway including diagnosis, prognosis, treatment, and data collection for real world evidence and cost effectiveness studies. Ultimately the PROMINENT project is expected to lead to cost-effective care and improved health outcomes.

Effects of odevixibat on pruritus and bile acids in children with cholestatic liver disease: Phase 2 study.

PURPOSE: Ileal bile acid transporter inhibition is a novel therapeutic concept for cholestatic pruritus and cholestatic liver disease progression. Odevixibat, a potent, selective, reversible ileal bile acid transporter inhibitor, decreases enteric bile acid reuptake with minimal systemic exposure. Oral odevixibat safety, tolerability, and efficacy in pediatric patients with cholestatic liver disease and pruritus were evaluated. PATIENTS AND METHODS: In this phase 2, open-label, multicenter study, children received 10‒200 µg/kg oral odevixibat daily for 4 weeks. Changes in serum bile acid levels (primary efficacy endpoint), pruritus, and sleep disturbance were explored. RESULTS: Twenty patients were enrolled (8 females; 1‒17 years; 4 re-entered at a different dose). Diagnoses included progressive familial intrahepatic cholestasis (n = 13; 3 re-entries), Alagille syndrome (n = 6), biliary atresia (n = 3), and other intrahepatic cholestasis causes (n = 2; 1 re-entry). Mean baseline serum bile acid levels were high (235 µmol/L; range, 26‒564) and were reduced in the majority (-123.1 µmol/L; range, -394 to 14.5, reflecting reductions of up to 98%). Patient-reported diary data documented improved pruritus (3 scales) and sleep. With 100 µg/kg, mean (SEM) decrease was 2.8 (1.1) points for pruritus (visual analogue itch scale 0-10) and 2.9 (0.9) points for sleep disturbance (Patient-Oriented Scoring Atopic Dermatitis scale 0-10). Reduced pruritus correlated significantly with reduced serum bile acids (P ≤ 0.007). Significant correlations were also observed between autotaxin levels and pruritus. All patients completed the study. No serious adverse events were treatment related; most adverse events, including increased transaminases, were transient. CONCLUSIONS: Orally administered odevixibat was well tolerated, reduced serum bile acids, and improved pruritus and sleep disturbance in children with cholestatic diseases.

Modeling the cost-effectiveness of prolonged-release fampridine for the treatment of walking impairment in patients with multiple sclerosis in Sweden.

Aims: To evaluate the cost-effectiveness of adding prolonged-release (PR)-fampridine to best supportive care (BSC) versus BSC alone for the improvement of walking ability in patients with MS.Methods: A cost-utility analysis based on a Markov model was developed to model responders and timed 25-foot walk (T25FW) scores, accumulated costs, and quality-adjusted life-years (QALY) in adults with MS and Expanded Disability Status Scale (EDSS) scores between 4 and 7. The analysis was conducted from a Swedish societal perspective.Results: In the base-case analysis, PR-fampridine plus BSC led to a higher QALY gain than BSC alone. The largest direct cost was professional care provision followed by hospital inpatient stays while the indirect cost was the loss of earnings due to days off work. The incremental cost-effectiveness ratio (ICER) for PR-fampridine plus BSC compared with BSC alone was 57,109 Swedish Kronor (kr)/QALY (€5,607/QALY [1 kr = €0.0981762 on 8 April 2021] and $6,675/QALY [1 kr = $0.116890 on 8 April 2021]). All sensitivity analyses performed resulted in ICERs below 500,000 kr (€49,088 and $58,445).Limitations: Resource use data were not specific to the Swedish market.Conclusions: PR-fampridine represents a cost-effective treatment for MS-related walking impairment in Sweden, due to improvements in patients' quality of life and reduced healthcare resource utilization.

Cost Effectiveness of Nusinersen in the Treatment of Patients with Infantile-Onset and Later-Onset Spinal Muscular Atrophy in Sweden.

BACKGROUND: Spinal muscular atrophy is a rare neuromuscular disorder with a spectrum of severity related to age at onset and the number of SMN2 gene copies. Infantile-onset (≤ 6 months of age) is the most severe spinal muscular atrophy and is the leading monogenetic cause of infant mortality; patients with later-onset (> 6 months of age) spinal muscular atrophy can survive into adulthood. Nusinersen is a new treatment for spinal muscular atrophy. OBJECTIVE: The objective of this study was to evaluate the cost effectiveness of nusinersen for the treatment of patients with infantile-onset spinal muscular atrophy and later-onset spinal muscular atrophy in Sweden. METHODS: One Markov cohort health-state transition model was developed for each population. The infantile-onset and later-onset models were based on the efficacy results from the ENDEAR phase III trial and the CHERISH phase III trial, respectively. The cost effectiveness of nusinersen in both models was compared with standard of care in Sweden. RESULTS: For a time horizon of 40 years in the infantile-onset model and 80 years in the later-onset model, treatment with nusinersen resulted in 3.86 and 9.54 patient incremental quality-adjusted life-years and 0.02 and 2.39 caregiver incremental quality-adjusted life-years and an incremental cost of 21.9 and 38.0 million SEK (Swedish krona), respectively. These results translated into incremental cost-effectiveness ratios (including caregiver quality-adjusted life-years) of 5.64 million SEK (€551,300) and 3.19 million SEK (€311,800) per quality-adjusted life-year gained in the infantile-onset model and later-onset model, respectively. CONCLUSIONS: Treatment with nusinersen resulted in overall survival and quality-adjusted life-year benefits but with incremental costs above 21 million SEK (€2 million) [mainly associated with maintenance treatment with nusinersen over a patient's lifespan]. Nusinersen was not cost effective when using a willingness-to-pay threshold of 2 million SEK (€195,600), which has been considered in a recent discussion by the Dental and Pharmaceutical Benefits Agency as a reasonable threshold for rare disease. Nonetheless, nusinersen gained reimbursement in Sweden in 2017 for paediatric patients (below 18 years old) with spinal muscular atrophy type I-IIIa.

An open prospective study evaluating efficacy and safety of a new medical device for rectal application of activated carbon in the treatment of chronic, uncomplicated perianal fistulas.

PURPOSE: It has been proposed that biological/chemical substances in the intestine might play a role in the occurrence and deterioration of perianal fistulas. Elimination of such unidentified factors from the lower gastrointestinal tract might offer a new strategy for the management of anal fistulas. The aim of this study was to evaluate the clinical effects on non-Crohn's disease perianal fistula healing, and the safety and tolerability of a new medical device that applies high-purity, high-activity granular activated carbon locally into the rectum twice daily of patients with perianal fistulas without any concomitant medication. METHODS: An open, single-arm, prospective study with active treatment for 8 weeks and an optional follow-up until week 24 ( ClinicalTrial.gov identifier NCT01462747) among patients with chronic, uncomplicated perianal fistulas scheduled for surgery was conducted. RESULTS: Of 28 patients included, 10 patients (35.7%) showed complete fistula healing (closed, no discharge on palpation) after 8 weeks; seven of these patients, corresponding to 25% of the enrolled patients, remained in remission for up to 31 weeks. At week 8, there was a statistically significant reduction in the discharge visual analog scale (p = 0.04), a significant improvement in the patient-perceived quality of life for the category of embarrassment (p = 0.002), and a trend toward improvement in the other assessment categories. CONCLUSIONS: The treatment was well tolerated, and patient acceptance was high. The results support the efficacy and safety of locally administered activated carbon for the treatment of patients with chronic uncomplicated perianal fistulas not receiving any other medication for fistula problems.

Direct and indirect costs for anal fistula in Sweden.

INTRODUCTION: Anal fistula is an abnormal tract with an external and internal opening that cause leakage, discomfort, and occasionally pain. Surgery is standard treatment, but recurrence and anal incontinence is common. The objective of the study was to analyze resource use, costs and sick leave for newly diagnosed patients with anal fistula in Sweden. METHODS: The study was based on register data from linkages between Swedish population-based registers including patients treated for anal fistula in Västra Götaland County, Sweden. Health care resource use, costs and sick leave were estimated. RESULTS: The sample included 362 patients of which 27% had no surgery, 37% had one surgery and 36% had multiple surgeries. Patients with multiple surgeries underwent over four surgeries on average. Approximately 67% of the contacts occurred during the first year after diagnosis. Estimated mean sick leave was 10.4 full-time equivalent days per patient. Total discounted costs were €5,561 per patient where approximately 80% were direct costs. DISCUSSION: To our knowledge this is the first study of resource use, costs and sick leave related to anal fistulas. The study indicates that anal fistula is a condition that is costly for society and that the burden of anal fistula in terms of health care resources and sick leave is especially high for patients experiencing multiple surgeries. CONCLUSION: Anal fistula is a condition that is costly for society and there is an unmet need for the group of patients with multiple surgeries to find appropriate treatment interventions.

All-cause pneumonia hospitalizations in children <2 years old in sweden, 1998 to 2012: impact of pneumococcal conjugate vaccine introduction.

BACKGROUND: In late 2007, some Swedish County Councils started 7-valent pneumococcal conjugate vaccine (PCV7) implementation for children, and PCV7 was included in the national immunization program in 2009. By 2010, both PCV10 and PCV13 were licensed, and the selection of vaccine was subject to County Councils tenders. This study investigated the impact of the order of PCV introduction into vaccination programs on the incidence of all-cause pneumonia hospitalizations in children <2 years-old. METHODS: Using population-based data from the publicly available National Inpatient Registry, the incidence of inpatient pneumonia (ICD-10 J12-J18) hospitalizations by County Councils among children <2 years old was identified between 1998 and 2012. Incidence rate ratios (IRR; 95% CI) were calculated during the nationwide implementation of PCV7 and then between County Councils, as based on the higher-valent vaccine chosen for a program. RESULTS: There was a lower risk of all-cause pneumonia hospitalization among <2 year-old children following the introduction of PCV7, as compared to the pre-PCV7 period (0.77; 0.63-0.93). A decreased risk of all-cause pneumonia was also observed in the County Councils that followed the order PCV7 then PCV13 (0.82; 0.66-1.01), while no trend was observed in County Councils with a program in the order PCV7 then PCV10 (1.03; 0.82-1.30). When comparing the higher-valent vaccines, there was a 21% (0.79; 0.66-0.96) lower risk for childhood pneumonia hospitalization in County Councils finally using PCV13 as compared to the experience in County Councils that ultimately adopted PCV10. CONCLUSIONS: Among children <2 years-old, all-cause pneumonia hospitalizations were significantly reduced by 23% one to two years after introduction of PCV7 vaccination in Sweden. In those County Councils that next introduced PCV13, a further decline in all-cause pneumonia hospitalization was observed, in contrast to those County Councils that followed with PCV10; this 21% lower risk for childhood pneumonia hospitalization was statistically significant.

A cost-effectiveness analysis of celecoxib compared with diclofenac in the treatment of pain in osteoarthritis (OA) within the Swedish health system using an adaptation of the NICE OA model.

OBJECTIVES: Celecoxib for the treatment of pain resulting from osteoarthritis (OA) was reviewed by the Tandvårds- och läkemedelsförmånsverket-Dental and Pharmaceutical Benefits Board (TLV) in Sweden in late 2010. This study aimed to evaluate the incremental cost-effectiveness ratio (ICER) of celecoxib plus a proton pump inhibitor (PPI) compared to diclofenac plus a PPI in a Swedish setting. METHODS: The National Institute for Health and Care Excellence (NICE) in the UK developed a health economic model as part of their 2008 assessment of treatments for OA. In this analysis, the model was reconstructed and adapted to a Swedish perspective. Drug costs were updated using the TLV database. Adverse event costs were calculated using the regional price list of Southern Sweden and the standard treatment guidelines from the county council of Stockholm. Costs for treating cardiovascular (CV) events were taken from the Swedish DRG codes and the literature. RESULTS: Over a patient's lifetime treatment with celecoxib plus a PPI was associated with a quality-adjusted life year (QALY) gain of 0.006 per patient when compared to diclofenac plus a PPI. There was an increase in discounted costs of 529 kr per patient, which resulted in an incremental cost-effectiveness ratio (ICER) of 82,313 kr ($12,141). Sensitivity analysis showed that treatment was more cost effective in patients with an increased risk of bleeding or gastrointestinal (GI) complications. CONCLUSIONS: The results suggest that celecoxib plus a PPI is a cost effective treatment for OA when compared to diclofenac plus a PPI. Treatment is shown to be more cost effective in Sweden for patients with a high risk of bleeding or GI complications. It was in this population that the TLV gave a positive recommendation. There are known limitations on efficacy in the original NICE model.

A higher score on the dermatology life quality index, being on systemic treatment and having a diagnosis of psoriatic arthritis is associated with increased costs in patients with plaque psoriasis.

The aim of this study was to examine the relationship between measures of disease severity and costs from a societal perspective in patients with plaque psoriasis. Dermatologists in Sweden recruited 443 consecutive patients who had had no biological treatment during the past 12 months. Following a Psoriasis Area and Severity Index (PASI) assessment, subjects completed self-assessments on health status/quality of life and a healthcare resource utilization/work status questionnaire. The costs of healthcare resources and sick-leave due to plaque psoriasis were estimated and related to the subject's health status. A patient's Dermatology Life Quality Index (DLQI) and being on systemic therapy, or having diagnosis of psoriatic arthritis, appeared to be more strongly associated with direct and indirect costs than did their PASI. The cost of biological therapy should be considered from the perspective of the already high costs of patients with high DLQI undergoing traditional systemic treatment.

Cost-effectiveness of a 10- versus 13-valent pneumococcal conjugate vaccine in Denmark and Sweden.

BACKGROUND: The introduction of a 7-valent pneumococcal polysaccharide-protein conjugate vaccine (PCV7) had profound public health effects across the globe. PCV7 vaccination in a national immunization program is generally considered cost-effective and potentially cost-saving. Two new PCVs have been launched, a 10-valent pneumococcal conjugate vaccine (PCV10) and a 13-valent pneumococcal conjugate vaccine (PCV13). OBJECTIVE: This article examines the public health and economic effects of pediatric national immunization programs of PCV10 and PCV13 in Denmark and Sweden. METHODS: A previously published decision-analytic model was used to estimate the impact of PCV10 and PCV13 on reducing cases of invasive pneumococcal disease (IPD), pneumonia (PNE), and acute otitis media (AOM) by using country-specific incidence, serotype coverage, disease sequelae, mortality, vaccine effectiveness, indirect effects, costs, and utilities. Direct effects for PCV13- and PCV10-covered serotypes were assumed similar to PCV7. PCV13 was assumed to confer an indirect effect, similar to PCV7, whereas PCV10 was not. Assumptions were tested in sensitivity analyses. RESULTS: PCV13 is expected to save 280.7 million DKK (Danish kroner) in Denmark and 288.2 million SEK (Swedish kronor) in Sweden in direct costs compared with a vaccination program with PCV10. In both Denmark and Sweden, the results of this study indicate that, compared with PCV10, PCV13 will have a greater impact on disease in life-years gained (LYG), quality-adjusted life-years (QALYs) gained, IPD cases avoided, PNE cases avoided, AOM cases avoided, and in deaths avoided. For Denmark PCV13, it was estimated to result in 10,051 LYG; 9063 QALYs gained; 237 additional IPD cases avoided; 12,094 additional PNE cases avoided; 958 additional cases of AOM avoided; and 882 additional deaths avoided. For Sweden PCV13, it was estimated to result in 4245 LYG; 3953 QALYs gained; 379 additional IPD cases avoided; 8210 additional PNE cases avoided; 1459 additional cases of AOM avoided; and 378 additional deaths avoided. In all sensitivity analyses, PCV13 was less costly and more effective compared with PCV10. CONCLUSIONS: In this analysis, a national immunization program with PCV13 was found to be good value for money and estimated to prevent additional cases of disease among children and nonvaccinated individuals and save additional costs due to treatment of pneumococcal disease, when compared with PCV10 in Denmark and Sweden.

Reduction of direct and indirect costs in patients with AS receiving etanercept: results from an open-label 36-week extension of the ASCEND study in four European countries.

OBJECTIVE: To characterize the impact of etanercept (ETN) in AS on cost, work productivity and quality of life (QoL). METHODS: A Phase 4, open-label, multi-centre (UK, Scandinavia) extension study in AS. Eligible subjects (n = 84) were treated for 36-52 weeks with ETN 50 mg s.c. once weekly. Analysis included direct costs (transformed out-patient and in-patient care elements), indirect costs (sick leave and lost working days), efficacy and QoL. RESULTS: Annualized direct and indirect costs decreased (55.5%, P ≤ 0.008) during ETN treatment, as did out-patient and in-patient episodes (physiotherapist/physician visits, P = 0.012). Work productivity and QoL increased. CONCLUSION: ETN therapy significantly reduces direct and indirect health-care costs and increases work ability and QoL in AS. Trial Registration. EUDRACT, https://eudract.ema.europa.eu/, 2006-001061-42.

Cost-effectiveness of treatment with etanercept for psoriasis in Sweden.

OBJECTIVE: To estimate the cost-effectiveness, from a Swedish societal perspective, of intermittent use of etanercept (Enbrel) with interruptions of use after 24 weeks compared to continuous use of adalimumab (Humira) as well as non-systemic standard of care in patients with moderate to severe psoriasis. METHODS: A Markov decision-tree model was constructed from clinical trials results. Patients starting etanercept, adalimumab, or non-systemic therapy moved through the model's 10-years horizon. Model input parameters included clinical response rates. Outcome measures included direct and indirect costs and quality-adjusted life-years (QALYs). RESULTS: The incremental total (direct and indirect) costs per QALY were 1,559,939 kr (165,354) for adalimumab 40 mg every other week, compared with intermittent once-weekly Enbrel 50 mg, and 93,629 kr (9,925) for once-weekly intermittent etanercept 50 mg compared with non-systemic standard of care. CONCLUSIONS: This analysis showed that, with a 470,000 kr (50,000) per QALY willingness-to-pay threshold, once-weekly etanercept 50 mg, used intermittently, is a cost-effective treatment for moderate to severe psoriasis compared with adalimumab and non-systemic standard of care.

Multicentre phase II trial of capecitabine and oxaliplatin in combination with radiotherapy for unresectable colorectal cancer: the CORGI-L Study.

AIMS: This study assessed radiotherapy combined with capecitabine and oxaliplatin in patients with primary, inextirpable colorectal adenocarcinoma. PATIENTS AND METHODS: Forty-nine patients entered the trial. Two cycles of XELOX (capecitabine 1000 mg/m(2) bid d1-14+oxaliplatin 130 mg/m(2) d1, q3w) were followed by radiotherapy (50.4 Gy), combined with capecitabine 825 mg/m(2) bid every radiotherapy day and oxaliplatin 60 mg/m(2) once weekly. The primary end-point was objective response. RESULTS: Forty-seven patients were evaluable. Twenty-nine (62% [95% CI: 46-75%]) achieved complete or partial response. Thirty-eight (81%) went through surgery of whom 37 (97%) had an R0 resection and five (13%) had a pathological complete response. Seventy-eight percent were alive and estimated local progression rate was 11% at 2 years. The most common grade 3+ toxicity during chemoradiotherapy was diarrhoea (24%). CONCLUSIONS: XELOX-RT was feasible and showed promising efficacy when treating patients with primary inextirpable colorectal cancer, establishing high local control rate.

Muscular exercise can cause highly pathological liver function tests in healthy men.

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT: The occurrence of idiosyncratic drug hepatotoxicity is a major problem in all phases of clinical drug development and the leading cause of postmarketing warnings and withdrawals. Physical exercise can result in transient elevations of liver function tests. There is no consensus in the literature on which forms of exercise may cause changes in liver function tests and to what extent. WHAT THIS STUDY ADDS: Weightlifting results in profound increases in liver function tests in healthy men used to moderate physical activity, not including weightlifting. Liver function tests are significantly increased for at least 7 days after weightlifting. It is important to impose relevant restrictions on heavy muscular exercise prior to and during clinical studies. AIM: To investigate the effect of intensive muscular exercise (weightlifting) on clinical chemistry parameters reflecting liver function in healthy men. METHODS: Fifteen healthy men, used to moderate physical activity not including weightlifting, performed an 1 h long weightlifting programme. Blood was sampled for clinical chemistry parameters [aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LD), gamma-glutamyl transferase (gamma GT), alkaline phosphatase (ALP), bilirubin, creatine kinase (CK) and myoglobin] at repeated intervals during 7 days postexercise and at a follow-up examination 10-12 days postexercise. RESULTS: Five out of eight studied clinical chemistry parameters (AST, ALT, LD, CK and myoglobin) increased significantly after exercise (P < 0.01) and remained increased for at least 7 days postexercise. Bilirubin, gamma GT and ALP remained within the normal range. CONCLUSION: The liver function parameters, AST and ALT, were significantly increased for at least 7 days after the exercise. In addition, LD and, in particular, CK and myoglobin showed highly elevated levels. These findings highlight the importance of imposing restrictions on weightlifting prior to and during clinical studies. Intensive muscular exercise, e.g. weightlifting, should also be considered as a cause of asymptomatic elevations of liver function tests in daily clinical practice.

Total parenteral nutrition causes circumferential intestinal atrophy, remodeling of the intestinal wall, and redistribution of eosinophils in the rat gastrointestinal tract.

Total parenteral nutrition (TPN) is held to cause intestinal atrophy and weaken mechanical and immunological barriers. To monitor the degree of atrophy caused by TPN, female Sprague-Dawley rats were, for 8 days, maintained on TPN (n = 6) and compared to identically housed controls given food and water ad libitum (n = 6). Specimens from jejunum, ileum, and colon were taken for histology and morphometric analysis. Topographic distribution and presence of eosinophils, by eosinophil peroxidase (EPO) staining, were examined in the gastric fundus, jejunum, ileum, and colon. Atrophy in terms of a markedly reduced circumference was noted throughout the intestinal tract in all rats subjected to TPN. The width of jejunal and ileal villi was narrowed and the length of jejunal villi was decreased. Furthermore, submucosal thickness in the jejunum and ileum increased. The height of ileal enterocytes remained unaltered. The number of goblet cells decreased in jejunal but not in ileal villi. The Paneth cells, suggested to play important roles in innate defense, increased in size. In the gastric fundus a marked increase in eosinophils was revealed predominantly in the mucosa and submucosa. The number and distribution of jejunal and ileal eosinophils were identical to those of controls. In colon from TPN rats, a redistribution of eosinophils was noted, causing a "band-like" accumulation of eosinophils in the basal portion of the mucosa. In conclusion, TPN causes gut atrophy and an increase in Paneth cell size. Eosinophils increase in number in the gastric fundus and a topographic redistribution occurs in the colon.

Gene and protein expression of P-glycoprotein, MRP1, MRP2, and CYP3A4 in the small and large human intestine.

The cytochrome P450 3A4 enzyme and the ABC-transporters may affect the first-pass extraction and bioavailability of drugs and metabolites. Conflicting reports can be found in the literature on the expression levels of efflux transporters in human intestine and how they vary along the intestine. The relative levels of mRNA and protein of CYP3A4 and the ABC tranporters Pgp (ABCB1), MRP1 (ABCC1), and MRP2 (ABCC2) were determined using RT-PCR and Western blot for human intestinal tissues (n = 14) from jejunum, ileum and colon. The expression of mRNA for CYP3A4, Pgp, and MRP2 was highest in jejunum and decreased toward more distal regions, whereas MRP1 was equally distributed in all intestinal regions. For CYP3A4, a more significant correlation could be established between mRNA and protein expression than for the ABC transporters. The samples showed considerable interindividual variability, especially at the protein level. The apically located Pgp and MRP2 showed a similar expression pattern along the human intestine as for CYP3A4. The gene expression of MRP1 exhibited a more uniform distribution.

Expression of islet inducible nitric oxide synthase and inhibition of glucose-stimulated insulin release after long-term lipid infusion in the rat is counteracted by PACAP27.

Chronic exposure of pancreatic islets to elevated plasma lipids (lipotoxicity) can lead to beta-cell dysfunction, with overtime becoming irreversible. We examined, by confocal microscopy and biochemistry, whether the expression of islet inducible nitric oxide synthase (iNOS) and the concomitant inhibition of glucose-stimulated insulin release seen after lipid infusion in rats was modulated by the islet neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP)27. Lipid infusion for 8 days induced a strong expression of islet iNOS, which was mainly confined to beta-cells and was still evident after incubating islets at 8.3 mmol/l glucose. This was accompanied by a high iNOS-derived NO generation, a decreased insulin release, and increased cyclic GMP accumulation. No iNOS expression was found in control islets. Addition of PACAP27 to incubated islets from lipid-infused rats resulted in loss of iNOS protein expression, increased cyclic AMP, decreased cyclic GMP, and suppression of the activities of neuronal constitutive (nc)NOS and iNOS and increased glucose-stimulated insulin response. These effects were reversed by the PKA inhibitor H-89. The suppression of islet iNOS expression induced by PACAP27 was not affected by the proteasome inhibitor MG-132, which by itself induced the loss of iNOS protein, making a direct proteasomal involvement less likely. Our results suggest that PACAP27 through its cyclic AMP- and PKA-stimulating capacity strongly suppresses not only ncNOS but, importantly, also the lipid-induced stimulation of iNOS expression, possibly by a nonproteasomal mechanism. Thus PACAP27 restores the impairment of glucose-stimulated insulin release and additionally might induce cytoprotection against deleterious actions of iNOS-derived NO in beta-cells.

Selective induction of inducible nitric oxide synthase in pancreatic islet of rat after an intravenous glucose or intralipid challenge.

OBJECTIVE: Constant exposure of pancreatic islets to high levels of glucose or free fatty acids can lead to irreversible beta-cell dysfunction, a process referred to as glucotoxicity or lipotoxicity, respectively. In this context a role for nitric oxide generated by pancreatic islet has been suggested. The present investigation examined whether the route of glucose administration, i.e., given orally (OG) or infused intravenously (IVG), could have any effect on the expression and activity of inducible nitric oxide synthase (iNOS) in pancreatic islets. METHODS: Rats were infused with glucose (50%) or Intralipid intravenously for 24 h or given glucose orally. A freely fed control group (FF) was also included. At 24 h rats were killed and blood samples were drawn for analysis of plasma insulin, glucagon, and glucose. Pancreatic islets were harvested from each animal and investigated for the occurrence of iNOS by the use of confocal microscopy, western blot, and high-performance liquid chromatographic analysis. The effect of intravenously infused glucose was then compared with the effect of an intravenous infusion of Intralipid (IL). RESULTS: Plasma insulin levels were markedly decreased after 24 h of infusion of glucose (IVG group) or Intralipid (IL group) compared with the FF or OG group. Plasma glucagon and glucose levels were markedly increased in the IVG group, whereas both parameters were decreased in the IL group. No significant differences in plasma insulin, glucagon, or glucose were found between the OG and FF groups. Immunocytochemical (confocal microscopy), western blot, and biochemical (high-performance liquid chromatographic) analyses showed that a sustained increase in plasma level of glucose or free fatty acids by an intravenous infusion of either nutrient for 24 h resulted in a marked expression and activity of iNOS in pancreatic islets. No sign of iNOS expression could, however, be detected in the islets of FF control or OG rats. CONCLUSION: The data suggest that impaired beta-cell function found after 24 h of an intravenous infusion of glucose or Intralipid might be mediated, at least in part, by the induction of iNOS in pancreatic islets. This may subsequently result in an exclusive production of nitric oxide, which is deleterious for beta-cells.