Histamine in the kidneys: what is its role in renal pathophysiology?

Starting with a role for histamine role in renal haemodynamics, evidence has accumulated, over time, suggesting a wider range of actions on renal function and this has renewed interest in the pathophysiological role of histamine in the kidney. Here we provide an up-to-date review of this topic. As the kidney expresses enzymes that synthesize and metabolise histamine, along with its receptors, all the components for histaminergic transmission are present in this tissue. The distribution of histamine receptors matches a wide range of effects. We address the questions of the redundancy of H1 and H2 receptors in renal haemodynamics, the complementary role of H1 and H4 receptors in renal filtration and reabsorption, and the dichotomy between local and neuronal H1 and H3 receptors. Experimental models of renal disease raise the possibility of new therapeutic approaches based on histamine. The effects of histamine on renal function are not yet fully understood and their elucidation is still ongoing. LINKED ARTICLES: This article is part of a themed section on New Uses for 21st Century. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.3/issuetoc.

Effects of vitamin D on insulin resistance and myosteatosis in diet-induced obese mice.

Epidemiological studies pointed out to a strong association between vitamin D deficiency and type 2 diabetes prevalence. However, the role of vitamin D supplementation in the skeletal muscle, a tissue that play a crucial role in the maintenance of glucose homeostasis, has been scarcely investigated so far. On this basis, this study aimed to evaluate the effect of vitamin D supplementation in a murine model of diet-induced insulin resistance with particular attention to the effects evoked on the skeletal muscle. Male C57BL/6J mice (n = 40) were fed with a control or a High Fat-High Sugar (HFHS) diet for 4 months. Subsets of animals were treated for 2 months with vitamin D (7 µg·kg-1, i.p. three times/week). HFHS diet induced body weight increase, hyperglycemia and impaired glucose tolerance. HFHS animals showed an impaired insulin signaling and a marked fat accumulation in the skeletal muscle. Vitamin D reduced body weight and improved systemic glucose tolerance. In addition, vitamin D restored the impaired muscle insulin signaling and reverted myosteatosis evoked by the diet. These effects were associated to decreased activation of NF-κB and lower levels of TNF-alpha. Consistently, a significantly decreased activation of the SCAP/SREBP lipogenic pathway and lower levels of CML protein adducts and RAGE expression were observed in skeletal muscle of animals treated with vitamin D. Collectively, these data indicate that vitamin D-induced selective inhibition of signaling pathways (including NF-κB, SCAP/SREBP and CML/RAGE cascades) within the skeletal muscle significantly contributed to the beneficial effects of vitamin D supplementation against diet-induced metabolic derangements.

A cooperation project between hospital pharmacists and general practitioners about drug interactions in clinical practice.

OBJECTIVES: (1) To evaluate drug-drug interactions (DDIs) in general practitioners' (GPs) prescriptions; (2) to implement a cooperation project between pharmacists and GPs to improve DDI management and patient care. METHODS: In 2013, pharmacists from the Community Drug Assistance ASL TO1 launched a cooperation project involving 48 GPs. As a first step, GPs were asked to select, from a list, drug associations for which they recommended analysis of occurrence in their prescriptions. The pharmacists (1) analysed GPs' prescriptions dated 2012-2014, according to the list of DDIs selected (n= 9); (2) evaluated solutions for DDI management, using the Micromedex DDI checker database and literature analysis; they then (3) disseminated DDI-related information to GPs through training meetings and (4) assessed the efficacy of these actions through a questionnaire submitted to the GPs in 2013. RESULTS: (1) Prescriptions analysis: a reduction in the number of DDIs was observed (-14% in 2013 vs 2012, -9% in 2014 vs 2012); in some cases these reductions were statistically significant (calcium carbonate + proton pump inhibitors (PPIs) -50%, p<0.0041, amoxicillin+lansoprazole -42%, p<0.0088). (2) Questionnaire: this was completed by 75% of GPs. The literature analysis was considered interesting by 94% of GPs; solutions were adopted by 89% of GPs and 34% of GPs affirmed that clinical improvements after application of the measures were observed in their patients, even if they could not provide quantitative data for this outcome. CONCLUSION: The cooperation project between pharmacists and GPs was effective because it established a professional exchange between the two health professionals. The pharmacist gave support to GPs, which benefited the patients, who gained clinical improvements and improved satisfaction with their medical care, as declared by the GPs in answers to the questionnaire.

Enhanced cytotoxic effect of camptothecin nanosponges in anaplastic thyroid cancer cells in vitro and in vivo on orthotopic xenograft tumors.

Anaplastic carcinoma of the thyroid (ATC) is a lethal human malignant cancer with median survival of 6 months. To date, no treatment has substantially changed its course, which makes urgent need for the development of novel drugs or novel formulations for drug delivery. Nanomedicine has enormous potential to improve the accuracy of cancer therapy by enhancing availability and stability, decreasing effective doses and reducing side effects of drugs. Camptothecin (CPT) is an inhibitor of DNA topoisomerase-I with several anticancer properties but has poor solubility and a high degradation rate. Previously, we reported that CPT encapsulated in ß-cyclodextrin-nanosponges (CN-CPT) increased solubility, was protected from degradation and inhibited the growth of prostate tumor cells both in vitro and in vivo. The aim of this study was to extend that work by assessing the CN-CPT effectiveness on ATC both in vitro and in vivo. Results showed that CN-CPT significantly inhibited viability, clonogenic capacity and cell-cycle progression of ATC cell lines showing a faster and enhanced effect compared to free CPT. Moreover, CN-CPT inhibited tumor cell adhesion to vascular endothelial cells, migration, secretion of pro-angiogenic factors (IL-8 and VEGF-α), expression of ß-PIX, belonging to the Rho family activators, and phosphorylation of the Erk1/2 MAPK. Finally, CN-CPT significantly inhibited the growth, the metastatization and the vascularization of orthotopic ATC xenografts in SCID/beige mice without apparent toxic effects in vivo. This work extends the previous insight showing that ß-cyclodextrin-nanosponges are a promising tool for the treatment of ATC.

Microvesicles released from fat-laden cells promote activation of hepatocellular NLRP3 inflammasome: A pro-inflammatory link between lipotoxicity and non-alcoholic steatohepatitis.

Non-Alcoholic Fatty Liver Disease (NAFLD) is a major form of chronic liver disease in the general population in relation to its high prevalence among overweight/obese individuals and patients with diabetes type II or metabolic syndrome. NAFLD can progress to steatohepatitis (NASH), fibrosis and cirrhosis and end-stage of liver disease but mechanisms involved are still incompletely characterized. Within the mechanisms proposed to mediate the progression of NAFLD, lipotoxicity is believed to play a major role. In the present study we provide data suggesting that microvesicles (MVs) released by fat-laden cells undergoing lipotoxicity can activate NLRP3 inflammasome following internalization by either cells of hepatocellular origin or macrophages. Inflammasome activation involves NF-kB-mediated up-regulation of NLRP3, pro-caspase-1 and pro-Interleukin-1, then inflammasome complex formation and Caspase-1 activation leading finally to an increased release of IL-1ß. Since the release of MVs from lipotoxic cells and the activation of NLRP3 inflammasome have been reported to occur in vivo in either clinical or experimental NASH, these data suggest a novel rational link between lipotoxicity and increased inflammatory response.

Histamine type 1-receptor activation by low dose of histamine undermines human glomerular slit diaphragm integrity.

Histamine has been reported to decrease the ultrafiltration coefficient, which inversely correlates with glomerular permselectivity, however the mechanism(s) underling this effect have never been investigated. This study aimed to assess whether histamine could exert a direct detrimental effect on podocyte permeability and the possible involvement of two key proteins for the glomerular slit diaphragm (SD) integrity, zonula occludens-1 (ZO-1) and P-cadherin. The effect of histamine (100 pM-1000nM) on coloured podocytes junctional integrity was evaluated functionally by a transwell assay of monolayer permeability and morphologically by electron microscopy. Histamine receptor (H1-4R) presence was evaluated at both mRNA (RT-PCR) and protein (immunofluorescence) levels. The Kd and Bmax values for [3H]mepyramine were determined by saturation binding analysis; IP1 and cAMP production evoked by histamine were measured by TR-FRET. ZO-1, P-cadherin and vimentin expression was assessed by qRT-PCR and quantitative immunoblotting. Histamine elicited a time- and sigmoidal dose-dependent (maximum effect at 8h, 10nM) increase in podocyte paracellular permeability widening the paracellular spaces. Only H1R was predominantly localised to the podocyte membrane. Consistently, histamine elicited a sigmoidal dose-dependent increase in IP1, but not in cAMP. Histamine exposure evoked a concentration-dependent reduction in both ZO-1 and P-cadherin and a parallel induction of vimentin mRNA expression with a maximum effect after 6h, and protein expression with a maximum effect after 8h. These effects were prevented by the selective H1R antagonist chlorpheniramine. In conclusion, our data demonstrate that histamine, via the H1R, modifies SD morphological and functional integrity, in part, by decreasing the expression of ZO-1 and P-cadherin.

Enhanced selective sonosensitizing efficacy of ultrasound-based anticancer treatment by targeted gold nanoparticles.

AIM: This study investigates cancer targeted gold nanoparticles as ultrasound sensitizers for the treatment of cancer. METHODS: The ultrasound sensitizer activity of folate-PEG decorated gold nanoparticles (FA-PEG-GNP) has been studied on human cancer cell lines that overexpress folate receptors (KB and HCT-116) and another that does not (MCF7), at two ultrasound energy densities (8 × 10-6 J cm-2 and 8 × 10-5 J cm-2, for 5 min at 1.866 MHz). RESULTS: FA-PEG-GNP selectively targeted KB and HCT-116 cells and a remarkable reduction in cancer cell growth was observed upon ultrasound exposure, along with significant reactive oxygen species generation and increase in necrotic cells. CONCLUSION: The combined use of targeting capacity and the ultrasound sensitizing effect, make FA-PEG-GNP promising candidates for the site-specific cancer treatment.

Empagliflozin Protects against Diet-Induced NLRP-3 Inflammasome Activation and Lipid Accumulation.

The aim of this study was to evaluate the effects of chronic treatment with empagliflozin, a potent and selective sodium glucose cotransporter-2 inhibitor, in a murine model of diet-induced obesity and insulin resistance, focusing on drug effects on body weight reduction and nucleotide-binding domain, leucine-rich repeat containing protein (NLRP)-3 inflammasome activation, which have never been investigated to date. Male C57BL/6 mice were fed control or a high fat-high sugar (HFHS) diet for 4 months. Over the last 2 months, subsets of animals were treated with empagliflozin (1-10 mg/kg) added to the diet. Empagliflozin evoked body weight reduction (P < 0.001 for the highest dose) and positive effects on fasting glycemia and homeostasis model assessment of insulin resistance. In addition, the drug was able to reduce renal tubular damage and liver triglycerides level in a dose-dependent manner. Interestingly, empagliflozin also decreased cardiac lipid accumulation. Moreover, diet-induced activation of NLRP-3 in kidney and liver (not observed in the heart) was dose-dependently attenuated by empagliflozin. Our results clearly demonstrate the ability of empagliflozin to counteract the deleterious effects evoked by chronic exposure to HFHS diet. Most notably, empagliflozin treatment was associated with NLRP-3 inflammasome signaling modulation, suggesting that this inhibition may contribute to the drug therapeutic effects.

In Vitro and In Vivo Therapeutic Evaluation of Camptothecin-Encapsulated ß-Cyclodextrin Nanosponges in Prostate Cancer.

Camptothecin (CPT), a pentacyclic alkaloid, is an inhibitor of DNA Topoisomerase-I and shows a wide spectrum of anti-cancer activities. The use of CPT has been hampered by poor aqueous solubility and a high degradation rate. Previously, it has been reported that CPT encapsulated in ß-cyclodextrin-nanosponges (CN-CPT) overcomes these disadvantages and improves the CPT's inhibitory effect on DU145 prostate tumor cell lines, and PC-3 growth in vitro. This work extends these observations by showing that CN-CPT significantly inhibits the adhesion and migration of these tumor cells and their STAT3 phosphorylation. The anti-adhesive effect is exerted also in human endothelial cells, in which CN-CPT also inhibits the angiogenic activity as assessed by the tubulogenesis and sprouting assays. Finally, CN-CPT substantially delays the growth of PC-3 cell engraftment in SCID mice in vivo without apparent toxic effects. These results support the use of ß-cyclodextrin nanosponge nanotechnology as a potential nanocarrier for delivery of anticancer drugs in the treatment of prostate cancers.

Targeting the NLRP3 Inflammasome to Reduce Diet-Induced Metabolic Abnormalities in Mice.

Although the molecular links underlying the causative relationship between chronic low-grade inflammation and insulin resistance are not completely understood, compelling evidence suggests a pivotal role of the nucleotide-binding oligomerization domain (NOD)-like receptor pyrin domain containing 3 (NLRP3) inflammasome. Here we tested the hypothesis that either a selective pharmacological inhibition or a genetic downregulation of the NLRP3 inflammasome results in reduction of the diet-induced metabolic alterations. Male C57/BL6 wild-type mice and NLRP3-/- littermates were fed control diet or high-fat, high-fructose diet (HD). A subgroup of HD-fed wild-type mice was treated with the NLRP3 inflammasome inhibitor BAY 11-7082 (3 mg/kg intraperitoneally [IP]). HD feeding increased plasma and hepatic lipids and impaired glucose homeostasis and renal function. Renal and hepatic injury was associated with robust increases in profibrogenic markers, while only minimal fibrosis was recorded. None of these metabolic abnormalities were detected in HD-fed NLRP3-/- mice, and they were dramatically reduced in HD-mice treated with the NLRP3 inflammasome inhibitor. BAY 11-7082 also attenuated the diet-induced increase in NLRP3 inflammasome expression, resulting in inhibition of caspase-1 activation and interleukin (IL)-1ß and IL-18 production (in liver and kidney). Interestingly, BAY 11-7082, but not gene silencing, inhibited nuclear factor (NF)-κB nuclear translocation. Overall, these results demonstrate that the selective pharmacological modulation of the NLRP3 inflammasome attenuates the metabolic abnormalities and the related organ injury/dysfunction caused by chronic exposure to HD, with effects similar to those obtained by NLRP3 gene silencing.

Fumaric acid esters prevent the NLRP3 inflammasome-mediated and ATP-triggered pyroptosis of differentiated THP-1 cells.

Fumaric acid esters (FAEs) exert therapeutic effects in patients with psoriasis and multiple sclerosis, however their mode of action remains elusive. Pyroptosis is a caspase-1-dependent pro-inflammatory form of programmed cell death, mediated by the activation of inflammasomes. To understand the pharmacological basis of the therapeutic effects of FAEs, the anti-pyroptotic activity of dimethyl fumarate (DMF) and its hydrolysis metabolite monomethyl fumarate (MMF) was studied in a model of NLRP3 inflammasome-mediated pyroptosis of human macrophages. Phorbol myristate acetate-differentiated THP-1 cells were exposed to lipopolysaccharide (5 µg/ml; 4h), then pulsed with ATP (5mM; 1h). MMF, DMF, or parthenolide (positive control) were added 1h before the ATP pulse. The pyroptotic cell death was evaluated by morphological examination and quantified by measuring the lactate dehydrogenase leakage. The ATP-triggered death of THP-1 cells (60.4 ± 4.0%) was significantly (P<0.01) prevented by DMF, in a time- and concentration-dependent manner (pIC50 and maximal effect were 6.6 and 67.6 ± 1.2%, respectively). MMF was less efficacious than DMF. These effects were accompanied by a decreased intracellular activation of caspase-1 and interleukin-1ß release from ATP-treated cells, thus suggesting that FAEs antagonise the effects of ATP by preventing the activation of the pyroptotic molecular cascade leading to cell death. These results indicate that FAEs are endowed with anti-pyroptotic activity, which may contribute to their therapeutic effects.

Electrophilic warhead-based design of compounds preventing NLRP3 inflammasome-dependent pyroptosis.

Pyroptosis is a caspase-1-dependent pro-inflammatory form of programmed cell death implicated in the pathogenesis of autoinflammatory diseases as well as in disorders characterized by excessive cell death and inflammation. Activation of NLRP3 inflammasome is a key event in the pyroptotic cascade. In this study, we describe the synthesis and chemical tuning of α,ß-unsaturated electrophilic warheads toward the development of antipyroptotic compounds. Their pharmacological evaluation and structure-activity relationships are also described. Compound 9 was selected as a model of this series, and it proved to be a reactive Michael acceptor, irreversibly trapping thiol nucleophiles, which prevented both ATP- and nigericin-triggered pyroptosis of human THP-1 cells in a time- and concentration-dependent manner. Moreover, 9 and other structurally related compounds, inhibited caspase-1 and NLRP3 ATPase activities. Our findings can contribute to the development of covalent, multitarget antipyroptotic compounds targeting molecular components of the NLRP3 inflammasome regulatory pathway.

B7h triggering inhibits the migration of tumor cell lines.

Vascular endothelial cells (ECs) and several cancer cells express B7h, which is the ligand of the ICOS T cell costimulatory molecule. We have previously shown that B7h triggering via a soluble form of ICOS (ICOS-Fc) inhibits the adhesion of polymorphonuclear and tumor cell lines to HUVECs; thus, we suggested that ICOS-Fc may act as an anti-inflammatory and antitumor agent. Because cancer cell migration and angiogenesis are crucial for metastasis dissemination, the aim of this work was to evaluate the effect of ICOS-Fc on the migration of cancer cells and ECs. ICOS-Fc specifically inhibited the migration of HUVECs, human dermal lymphatic ECs, and the HT29, HCT116, PC-3, HepG2, JR8, and M14 tumor cell lines expressing high levels of B7h, whereas it was ineffective in the RPMI7932, PCF-2, LM, and BHT-101 cell lines expressing low levels of B7h. Furthermore, ICOS-Fc downmodulated hepatocyte growth factor facilitated the epithelial-to-mesenchymal transition in HepG2 cells. Moreover, ICOS-Fc downmodulated the phosphorylation of focal adhesion kinase and the expression of ß-Pix in both HUVECs and tumor cell lines. Finally, treatment with ICOS-Fc inhibited the development of lung metastases upon injection of NOD-SCID-IL2Rγnull mice with CF-PAC1 cells, as well as C57BL/6 mice with B16-F10 cells. Therefore, the B7h-ICOS interaction may modulate the spread of cancer metastases, which suggests the novel use of ICOS-Fc as an immunomodulatory drug. However, in the B16-F10-metastasized lungs, ICOS-Fc also increased IL-17A/RORc and decreased IL-10/Foxp3 expression, which indicates that it also exerts positive effects on the antitumor immune response.

New chitosan nanospheres for the delivery of 5-fluorouracil: preparation, characterization and in vitro studies.

The aim of this work was to develop new chitosan nanospheres for the delivery of 5-fluorouracil (5-FU). Drug loaded nanospheres were prepared using a technique derived from a combination of coacervation and emulsion droplet coalescence methods. The size and morphology of nanospheres were characterized by laser light scattering and transmission electron microscopy. The 5-FU interaction with chitosan nanospheres was investigated by DSC analysis and FT-IR spectroscopy. The in vitro release was studied by dialysis bag technique. Cytotoxicity of 5-FU loaded chitosan nanospheres was evaluated in vitro on HT29 and PC-3 cell lines. The effects of 5-FU loaded chitosan nanospheres on adhesion of tumor cells to human umbilical vein endothelial cells (HUVEC) were also investigated. 5-FU loaded chitosan nanospheres appeared with a spherical shape, with a mean diameter of about 200 nm and a negative zeta potential of about - 6.0 mV. The successful interaction between drug and chitosan nanosphere matrix was demonstrated by both DSC and FT-IR analyses. The quantitative determination of 5-FU was assayed by UV-Vis analysis. The encapsulation efficiency of 5-FU content was about 70%. A kinetic study of in vitro release demonstrated that the percentages of 5-FU delivered from nanospheres was approx. 10% after 3 hours. The in vitro studies showed that 5-FU loaded nanospheres were effective in reducing tumor cell proliferation in a time- and concentration-dependent manner. 5-FU nanospheres were also able to inhibit both HT29 and PC-3 adhesion to HUVEC after 48 hours of treatment.

Acute treatment with relaxin protects the kidney against ischaemia/reperfusion injury.

Although recent preclinical and clinical studies have demonstrated that recombinant human relaxin (rhRLX) may have important therapeutic potential in acute heart failure and chronic kidney diseases, the effects of acute rhRLX administration against renal ischaemia/reperfusion (I/R) injury have never been investigated. Using a rat model of 1-hr bilateral renal artery occlusion followed by 6-hr reperfusion, we investigated the effects of rhRLX (5 µg/Kg i.v.) given both at the beginning and after 3 hrs of reperfusion. Acute rhRLX administration attenuated the functional renal injury (increase in serum urea and creatinine), glomerular dysfunction (decrease in creatinine clearance) and tubular dysfunction (increase in urinary excretion of N-acetyl-ß-glucosaminidase) evoked by renal I/R. These beneficial effects were accompanied by a significant reduction in local lipid peroxidation, free radical-induced DNA damage and increase in the expression/activity of the endogenous antioxidant enzymes Mn- and CuZn-superoxide dismutases (SOD). Furthermore, rhRLX administration attenuated the increase in leucocyte activation, as suggested by inhibition of myeloperoxidase activity, intercellular-adhesion-molecule-1 expression, interleukin (IL)-1ß, IL-18 and tumour necrosis factor-α production as well as increase in IL-10 production. Interestingly, the reduced oxidative stress status and neutrophil activation here reported were associated with rhRLX-induced activation of endothelial nitric oxide synthase and up-regulation of inducible nitric oxide synthase, possibly secondary to activation of Akt and the extracellular signal-regulated protein kinase (ERK) 1/2, respectively. Thus, we report herein that rhRLX protects the kidney against I/R injury by a mechanism that involves changes in nitric oxide signalling pathway.

High sugar intake and development of skeletal muscle insulin resistance and inflammation in mice: a protective role for PPAR- δ agonism.

Peroxisome Proliferator Activated Receptor (PPAR)- δ agonists may serve for treating metabolic diseases. However, the effects of PPAR- δ agonism within the skeletal muscle, which plays a key role in whole-body glucose metabolism, remain unclear. This study aimed to investigate the signaling pathways activated in the gastrocnemius muscle by chronic administration of the selective PPAR- δ agonist, GW0742 (1 mg/kg/day for 16 weeks), in male C57Bl6/J mice treated for 30 weeks with high-fructose corn syrup (HFCS), the major sweetener in foods and soft-drinks (15% wt/vol in drinking water). Mice fed with the HFCS diet exhibited hyperlipidemia, hyperinsulinemia, hyperleptinemia, and hypoadiponectinemia. In the gastrocnemius muscle, HFCS impaired insulin and AMP-activated protein kinase signaling pathways and reduced GLUT-4 and GLUT-5 expression and membrane translocation. GW0742 administration induced PPAR- δ upregulation and improvement in glucose and lipid metabolism. Diet-induced activation of nuclear factor-κB and expression of inducible-nitric-oxide-synthase and intercellular-adhesion-molecule-1 were attenuated by drug treatment. These effects were accompanied by reduction in the serum concentration of interleukin-6 and increase in muscular expression of fibroblast growth factor-21. Overall, here we show that PPAR- δ activation protects the skeletal muscle against the metabolic abnormalities caused by chronic HFCS exposure by affecting multiple levels of the insulin and inflammatory cascades.

Beneficial effect of prolonged heme oxygenase 1 activation in a rat model of chronic heart failure.

We and others have previously demonstrated that heme oxygenase 1 (HO-1) induction by acute hemin administration exerts cardioprotective effects. Here, we developed a rat model of heart failure to investigate whether a long-term induction of HO-1 by chronic hemin administration exerted protective effects. Sprague Dawley rats that underwent permanent ligation of the left coronary artery were closely monitored for survival rate analysis and sacrificed on day 28 post-operation. Administration of hemin (4 mg/kg body weight) every other day for 4 weeks induced a massive increase in HO-1 expression and activity, as shown by the increased levels of the two main metabolic products of heme degradation, bilirubin and carbon monoxide (CO). These effects were associated with significant improvement in survival and reduced the extension of myocardial damage. The ischemic hearts of the hemin-treated animals displayed reduced oxidative stress and apoptosis in comparison with the non-treated rats, as shown by the decreased levels of lipid peroxidation, free-radical-induced DNA damage, caspase-3 activity and Bax expression. Besides, chronic HO-1 activation suppressed the elevated levels of myeloperoxidase (MPO) activity, interleukin 1ß (IL-1ß) production and tumor necrosis factor-α (TNFα) production that were evoked by the ischemic injury, and increased the plasma level of the anti-inflammatory cytokine IL-10. Interestingly, HO-1 inhibitor zinc protoporphyrin IX (ZnPP-IX; 1 mg/kg) lowered bilirubin and CO concentrations to control values, thus abolishing all the cardioprotective effects of hemin. In conclusion, the results demonstrate that chronic HO-1 activation by prolonged administration of hemin improves survival and exerts protective effects in a rat model of myocardial ischemia by exerting a potent antioxidant activity and disrupting multiple levels of the apoptotic and inflammatory cascade.

Triggering of B7h by the ICOS modulates maturation and migration of monocyte-derived dendritic cells.

B7h, expressed by several cell types, binds ICOS expressed by activated T cells. We have previously shown that B7h triggering by ICOS-Fc inhibits human endothelial cell adhesiveness. This work investigated the effect of ICOS-Fc on human monocyte-derived dendritic cells (DCs). We found that DCs matured with LPS in the presence of ICOS-Fc (mDCs(ICOS)) produced greater amounts of IL-23 and IL-10, and promoted a higher secretion of IL-17A and IL-17F in MLCs than did those DCs matured with LPS alone (mDCs). Moreover, mDCs(ICOS) pulsed with the keyhole limpet hemocyanin Ag during the maturation phase were better stimulators of Ag-specific MHC class I-, but not class II-restricted T cells than mDCs. This was probably due to promotion of cross-presentation because it was not detected when the Flu-MA(58-66) Ag was directly loaded on already matured DCs and mDCs(ICOS). Finally, ICOS-Fc inhibited the adhesion of both immature DCs and mDCs to vascular and lymphoid endothelial cells, their migratory activity, and the expression of the Rac-1 activator ß-Pix involved in cell motility. These data suggest that B7h stimulation modulates DC function with effects on their maturation and recruitment into tissues. This opens a novel view on the use of interactors of the ICOS:B7h system as immunomodulatory drugs.

Reversal of the deleterious effects of chronic dietary HFCS-55 intake by PPAR-δ agonism correlates with impaired NLRP3 inflammasome activation.

Although high-fructose corn syrup (HFCS-55) is the major sweetener in foods and soft-drinks, its potential role in the pathophysiology of diabetes and obesity ("diabesity") remains unclear. Peroxisome-proliferator activated receptor (PPAR)-δ agonists have never been tested in models of sugar-induced metabolic abnormalities. This study was designed to evaluate (i) the metabolic and renal consequences of HFCS-55 administration (15% wt/vol in drinking water) for 30 weeks on male C57Bl6/J mice and (ii) the effects of the selective PPAR-δ agonist GW0742 (1 mg/kg/day for 16 weeks) in this condition. HFCS-55 caused (i) hyperlipidemia, (ii) insulin resistance, and (iii) renal injury/inflammation. In the liver, HFCS-55 enhanced the expression of fructokinase resulting in hyperuricemia and caused abnormalities in known insulin-driven signaling events. In the kidney, HFCS-55 enhanced the expression of the NLRP3 (nucleotide-binding domain and leucine-rich-repeat-protein 3) inflammasome complex, resulting in caspase-1 activation and interleukin-1ß production. All of the above effects of HFCS-55 were attenuated by the specific PPAR-δ agonist GW0742. Thus, we demonstrate for the first time that the specific PPAR-δ agonist GW0742 attenuates the metabolic abnormalities and the renal dysfunction/inflammation caused by chronic HFCS-55 exposure by preventing upregulation of fructokinase (liver) and activation of the NLRP3 inflammasome (kidney).