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. IntroductionAchieving long-lasting insulin independence after portal vein islet transplantation has improved, but remains challenging. Nonspecific immune activation (1-6), along with preexisting and transplant-induced auto-and allospecific immune responses (7-9), are components affecting outcome; these are not fully suppressed by ongoing protocols of generalized immunosuppression. Increasing general immunosuppression potency is not ideal because of side effects. Consequently, the development of novel protocols that specifically target proinflammatory immune cell compartments that impede islet function and survival is compelling.

Chemokines and their receptors have been associated with or implicated in the pathogenesis of type 1 diabetes (T1D), but the identification of a single specific chemokine/receptor pathway that may constitute a suitable target for the development of therapeutic interventions is still lacking. Here, we used multiple low-dose (MLD) streptozotocin (STZ) injections and the NOD mouse model to investigate the potency of CXCR1/2 inhibition to prevent inflammation- and autoimmunity-mediated damage of pancreatic islets. Reparixin and ladarixin, noncompetitive allosteric inhibitors, were used to pharmacologically blockade CXCR1/2. Transient blockade of said receptors was effective in preventing inflammation-mediated damage in MLD-STZ and in preventing and reversing diabetes in NOD mice. Blockade of CXCR1/2 was associated with inhibition of insulitis and modification of leukocytes distribution in blood, spleen, bone marrow, and lymph nodes. Among leukocytes, CXCR2+ myeloid cells were the most decreased subpopulations. Together these results identify CXCR1/2 chemokine receptors as “master regulators” of diabetes pathogenesis. The demonstration that this strategy may be successful in preserving residual β-cells holds the potential to make a significant change in the approach to management of human T1D.

Reparixin is an inhibitor of CXCR1/2 chemokine receptor shown to be an effective anti-inflammatory adjuvant in a pilot clinical trial in allotransplant recipients. RESEARCH DESIGN AND METHODSA phase 3, multicenter, randomized, double-blind, parallel-assignment study (NCT01817959) was conducted in recipients of islet allotransplants randomized (2:1) to reparixin or placebo in addition to immunosuppression. Primary outcome was the area under the curve (AUC) for C-peptide during the mixed-meal tolerance test at day 75 6 5 after the first and day 365 6 14 after the last transplant. Secondary end points included insulin independence and standard measures of glycemic control. RESULTSThe intention-to-treat analysis did not show a significant difference in C-peptide AUC at both day 75 (27 on reparixin vs. 18 on placebo, P 5 0.99) and day 365 (24 on reparixin vs. 15 on placebo, P 5 0.71). There was no statistically significant difference between treatment groups at any time point for any secondary variable. Analysis of patient subsets showed a trend for a higher percentage of subjects retaining insulin independence for 1 year after a single islet infusion in patients receiving reparixin as compared with patients receiving placebo (26.7% vs. 0%, P 5 0.09) when antithymocyte globulin was used as induction immunosuppression. CONCLUSIONSIn this first double-blind randomized trial, islet transplantation data obtained with reparixin do not support a role of CXCR1/2 inhibition in preventing islet inflammationmediated damage.Pancreatic islet transplantation has become a feasible option in the treatment of uncontrolled type 1 diabetes (T1D) that allows long-term sustained function and improved metabolic control even when exogenous insulin is required (1). Although significant progress has been made in islet transplantation, several limitations remain that preclude its widespread application (2). Among others, the loss of up to 75% of

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Glutathione (GSH) is one of the most important defense mechanisms against oxidative stress in the respiratory epithelial lining fluid. Considering that GSH secretion in respiratory cells has been postulated to be at least partially electrogenic, and that the mucoregulator S-carbocysteine lysine salt monohydrate (S-CMC-Lys) can cause an activation of epithelial Cl(-) conductance, the purpose of this study was to verify whether S-CMC-Lys is able to stimulate GSH secretion. Experiments have been performed by patch-clamp technique, by high-performance liquid chromatography (HPLC) assay, and by Western blot analysis on cultured lines of human respiratory cells (WI-26VA4 and CFT1-C2). In whole-cell configuration, after cell exposure to 100 microM S-CMC-Lys, a current due to an outward GSH flux was observed, which was inhibitable by 5-nitro-2-(3-phenylpropylamino)-benzoate and glibenclamide. This current was not observed in CFT1-C2 cells, where a functional cystic fibrosis transmembrane conductance regulator (CFTR) is lacking. Inside-out patch-clamp experiments (GSH on the cytoplasm side, Cl(-) on the extracellular side) showed the activity of a channel, which was able to conduct current in both directions: the single channel conductance was 2-4 pS, and the open probability (P(o)) was low and voltage-independent. After preincubation with 100 microM S-CMC-Lys, there was an increase in P(o), in the number of active channels present in each patch, and in the relative permeability to GSH vs Cl(-). Outwardly directed efflux of GSH could also be increased by protein kinase A, adenosine 5'-triphosphate, and cyclic adenosine monophosphate (cAMP) added to the cytoplasmic side (whole-cell configuration). The increased secretion of GSH observed in the presence of S-CMC-Lys or 8-bromoadenosine-3',5'-cyclic monophosphate was also confirmed by HPLC assay of GSH on a confluent monolayer of respiratory cells. Western blot analysis confirmed the presence of CFTR in WI-26VA4 cells. This study suggests that S-CMC-Lys is able to stimulate a channel-mediated GSH secretion by human respiratory cells: electrophysiological and pharmacological characteristics of this channel are similar to those of the CFTR channel.

Nonproductive cough is a frequent and distressing symptom in patients with lung cancer, and it is not even relieved by palliative chemotherapy. A double-blind, randomized clinical trial regarding the treatment of nonproductive cough was performed in 140 adults with primary lung cancer or metastatic cancer of the lungs. The therapeutic efficacy and the tolerability of a 7-day treatment with levodropropizine drops (75 mg t.i.d.) were evaluated in comparison with dihydrocodeine drops (10 mg t.i.d.; 7 days). Efficacy was assessed on the basis of cough severity scores, number of night awakenings due to cough, and overall estimate of antitussive efficacy. Tolerability was evaluated by laboratory results, vital signs and any adverse event occurring during the clinical trial, including presence or absence of somnolence. Subjective cough severity was significantly reduced during treatment with either levodropropizine and dihydrocodeine, the antitussive effect and its time-profile being similar for both drugs. Also, according to the investigator's evaluation, both levodropropizine and dihydrocodeine produced a significant decrease in cough severity. Concurrently with the relief of cough, the number of night awakenings was decreased significantly by both drugs, with no difference between the two treatments. No change in laboratory test values was considered clinically relevant, and vital signs were not clinically affected. The number of patients reporting adverse events was similar in the levodropropizine (n=6) and dihydrocodeine (n=4) group. However, the percentage of patients experiencing somnolence in the group receiving levodropropizine (8%) was significantly lower as compared with that of the dihydrocodeine group (22%). These results confirm the antitussive effectiveness of levodropropizine and suggest a more favourable benefit/risk profile when compared to dihydrocodeine.

Anaphylactic bronchoconstriction provoked by aerosol challenge, and its pharmacological modulation, has been investigated in anaesthetized pump‐ventilated guinea‐pigs actively sensitized to ovalbumin (OA). Aerosol challenge (OA 0.03–10 mg ml−1) provoked immediate bronchoconstriction, the degree of which, and its rate of development, was directly related to antigen concentration. Concomitant changes in heart rate and systemic arterial blood pressure following aerosol challenge were reduced compared with systemic (OA, 1 mg kg−1 i.v.) challenge. Unlike systemic challenge, aerosol challenge did not cause a concomitant fall in either circulating leukocyte or platelet count. When a submaximal (microshock) aerosol challenge stimulus (OA, 0.3 mg ml−1, 5 s) was employed, bronchoconstriction was markedly reduced by mepyramine (2 mg kg−1 i.v.). The residual component of bronchoconstriction was enhanced by indomethacin (10 mg kg−1 i.v.), an effect which was reversed by either BW755C (30 mg kg−1 i.v.) or FPL55712 (10 mg kg−1 i.v.). When a supramaximal (macroshock) aerosol challenge stimulus (OA, 10 mg ml−1, 5 s) was employed, bronchoconstriction was also markedly reduced by mepyramine. Residual bronchoconstriction was not altered by indomethacin, slowed but not reduced by indomethacin plus BW755C, and substantially reduced by indomethacin plus FPL55712. The successive incremental antagonism of anaphylactic bronchoconstriction by mepyramine and mepyramine plus indomethacin and FPL55712 indicates that the predominant mediators involved are histamine and leukotrienes, respectively. The failure of indomethacin plus BW755C to inhibit the mepyramine‐resistant bronchoconstriction provoked by OA macroshock may reflect the increased generation of leukotrienes via a 5‐lipoxygenase isoenzyme resistant to inhibition by BW755C. Aerosol challenge of actively sensitized anaesthetized guinea‐pigs by this method may be a useful model of human allergic bronchoconstriction, particularly when the effects of a drug given itself as an aerosol are being evaluated.

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