Hydralazine reduces leukocyte migration through different mechanisms in spontaneously hypertensive and normotensive rats

In addition to reducing blood pressure, hydralazine can reduce the production of inflammatory cytokines and reduce the expression of leukocyte adhesion molecules. Differences in leukocyte behavior and leukocyte adhesion molecule expression in spontaneously hypertensive rats (SHR) compared to normotensive rats have been reported. However, whether hydralazine can reduce leukocyte migration in vivo in hypertension and in normotension remains unknown. To address this question, male SHR and Wistar rats were treated for 15 days with hydralazine at a dose of similar to 3.5 mg/kg or similar to 14 mg/kg in their drinking water. The numbers of rollers and adherent and migrated cells were determined by direct vital microscopy, and blood pressure was assessed by tail plethysmography. In addition, following treatment with the higher dose, immunohistochemistry was used to measure the expression of intercellular adhesion molecule-1 (ICAM-1), P-selectin, and platelet-endothelial cell adhesion molecule-1 (PECAM-1) in endothelial cells, while flow cytometry was used to evaluate the expression of leukocyte CD18 and L-selectin. Hydralazine reduced leukocyte adherence and migration in SHR either at the higher, that reduced blood pressure levels, or lower dose, which did not reduce it. Reduced ICAM-1 expression might be involved in the reduced migration observed in SHR. In Wistar rats, only at the higher dose hydralazine reduced blood pressure levels and leukocyte migration. Reduced P-selectin expression might be involved. We therefore conclude that hydralazine reduces leukocyte migration by different mechanisms in SHR and Wistar rats, specifically by reducing ICAM-1 expression in the former and P-selectin expression in the latter. (c) 2008 Elsevier B.V. All rights reserved.

Insulin inhibits LPS-induced signaling pathways in alveolar macrophages

The systemic inflammatory response syndrome ( SIRS) is triggered by lipopolysaccharide (LPS) from Gram-negative bacteria. Insulin was shown to have a protective role in SIRS related to sepsis. Lungs are particularly affected in this condition and provide a second wave of mediators/cytokines which amplifies SIRS. The aim of the present study was to investigate the effect of insulin on the signaling pathways elicited by LPS in alveolar macrophages (AMs) and its consequence in cellular response to LPS measured as production of tumor necrosis factor (TNF). To this purpose, resident AMs from male Wistar rats were obtained by lung lavage and stimulated by LPS ( 100 ng/mL). Insulin ( 1 mU/mL) was added 10 min before LPS. Activation ( phosphorylation) of signaling molecules by LPS was analyzed by western blot, 30 min after LPS stimulation. TNF was measured in the AMs culture supernatants by bioassay using L-929 tumor cells. Relative to controls, LPS induced a significant increase in the activation of ERK (3.6-fold), p38 (4.4-fold), Tyr-326 Akt (4.7-fold), Ser-473 Akt (6.9-fold), PKCa (4.7-fold) and PKCd (2.3-fold). Treatment of AMs with insulin before LPS stimulation, significantly reduced the activation of ERK (54%), p38 (48%), Tyr-326 Akt (64%), Ser-473 Akt (41%), PKCa (62%) and PKCd (39%). LPS induced TNF production in AMs which was also inhibited by insulin (60%). These results show that insulin down-regulates MAPK, PI3K and PKCs and inhibits a downstream effect of LPS, TNF production, in rat AMs stimulated with LPS and suggest that the protective effect of insulin in sepsis could be through modulation of signal transduction pathways elicited by LPS in lung macrophages. Copyright (c) 2008 S. Karger AG, Basel.

THE ROLE OF INNATE IMMUNITY IN SEPTIC ACUTE KIDNEY INJURIES

Acute kidney injury (AKI) is an important clinical syndrome characterized by abnormalities in the hydroelectrolytic balance. Because of high rates of morbidity and mortality (from 15% to 60%) associated with AKI, the study of its pathophysiology is critical in searching for clinical targets and therapeutic strategies. Severe sepsis is the major cause of AKI. The host response to sepsis involves an inflammatory response, whereby the pathogen is initially sensed by innate immune receptors (pattern recognition receptors [PRRs]). When it persists, this immune response leads to secretion of proinflammatory products that induce organ dysfunction such as renal failure and consequently increased mortality. Moreover, the injured tissue releases molecules resulting from extracellular matrix degradation or dying cells that function as alarmines, which are recognized by PRR in the absence of pathogens in a second wave of injury. Toll-like receptors (TLRs) and NOD-like receptors (NLRs) are the best characterized PRRs. They are expressed in many cell types and throughout the nephron. Their activation leads to translocation of nuclear factors and synthesis of proinflammatory cytokines and chemokines. TLRs` signaling primes the cells for a robust inflammatory response dependent on NLRs; the interaction of TLRs and NLRs gives rise to the multiprotein complex known as the inflammasome, which in turn activates secretion of mature interleukin 1 beta and interleukin 18. Experimental data show that innate immune receptors, the inflammasome components, and proinflammatory cytokines play crucial roles not only in sepsis, but also in organ-induced dysfunction, especially in the kidneys. In this review, we discuss the significance of the innate immune receptors in the development of acute renal injury secondary to sepsis.

Diapocynin versus apocynin as pretranscriptional inhibitors of NADPH oxidase and cytokine production by peripheral blood mononuclear cells

Apocynin has been extensively used as an inhibitor of NADPH oxidase (NOX) in many experimental models using phagocytic and non-phagocytic cells. Currently, there is some controversy about the efficacy of apocynin in non-phagocytic cells, but in phagocytes the reported results are consistent, which could be due to the presence of myeloperoxidase in these cells. This enzyme has been proposed as responsible for activating apocynin by generating its dimer, diapocynin, which is supposed to be the active compound that prevents NADPH oxidase complex assembly and activation. Here, we synthesized diapocynin and studied its effect on inhibition of gp91(phox) RNA expression. We found that diapocynin strongly inhibited the expression of gp91(phox)mRNA in peripheral blood mononuclear cells (PBMC). Only at a higher concentration, apocynin was able to exert the same effect. We also compared the apocynin and diapocynin efficacy as inhibitors of tumor necrosis factor-alpha (TNF-alpha) and interleukin-10 (IL-10) production in response to lipopolysaccharide (LPS)-activated PBMC. Although apocynin did inhibit TNF-alpha production, diapocynin had a much more pronounced effect, on both TNF-alpha and IL-10 production. In conclusion, these findings suggest that the bioconversion of apocynin to diapocynin is an important issue not limited to enzymatic activity inhibition, but also for other biological effects as gp91(phox) mRNA expression and cytokine production. Hence, as diapocynin can be easily prepared from apocynin, a one-step synthesis, we recommend its use in studies where the biological effects of apocynin are searched. (C) 2010 Elsevier Inc. All rights reserved.

Mesenchymal Stem Cells Attenuate Renal Fibrosis Through Immune Modulation and Remodeling Properties in a Rat Remnant Kidney Model

Mesenchymal stem cells (MSCs) have regenerative properties in acute kidney injury, but their role in chronic kidney diseases is still unknown. More specifically, it is not known whether MSCs halt fibrosis. The purpose of this work was to investigate the role of MSCs in fibrogenesis using a model of chronic renal failure. MSCs were obtained from the tibias and femurs of male Wistar-EPM rats. Female Wistar rats were subjected to the remnant model, and 2 vertical bar x vertical bar 10(5) MSCs were intravenously administrated to each rat every other week for 8 weeks or only once and followed for 12 weeks. SRY gene expression was observed in female rats treated with male MSCs, and immune localization of CD73(+)CD90(+) cells at 8 weeks was also assessed. Serum and urine analyses showed an amelioration of functional parameters in MSC-treated animals at 8 weeks, but not at 12 weeks. Masson`s trichrome and Sirius red staining demonstrated reduced levels of fibrosis in MSC-treated animals. These results were corroborated by reduced vimentin, type I collagen, transforming growth factor beta, fibroblast specific protein 1 (FSP-1), monocyte chemoattractant protein 1, and Smad3 mRNA expression and alpha smooth muscle actin and FSP-1 protein expression. Renal interleukin (IL)-6 and tumor necrosis factor alpha mRNA expression levels were significantly decreased after MSC treatment, whereas IL-4 and IL-10 expression levels were increased. All serum cytokine expression levels were decreased in MSC-treated animals. Taken together, these results suggested that MSC therapy can indeed modulate the inflammatory response that follows the initial phase of a chronic renal injury. The immunosuppressive and remodeling properties of MSCs may be involved in the decreased fibrosis in the kidney. STEM CELLS 2009;27:3063-3073

Early modulation of inflammation by mesenchymal stem cell after acute kidney injury

Therapy with stem cells has showed to be promising for acute kidney injury (AKI), although how it works is still controversial. Modulation of the inflammatory response is one possible mechanism. Most of published data relies on early time and whether the protection is still maintained after that is not known. Here, we analyzed whether immune modulation continues after 24 h of reperfusion. MSC were obtained from male Wistar rats. After 3-5 passages, cells were screened for CD73, CD90, CD44, CD45, CD29 and CD 31. In addition, MSC were submitted to differentiation in adipocyte and in osteocyte. AKI was induced by bilaterally clamping of renal pedicles for 60 min. Six hours after injury, MSC (2 x 105 cells) were administered intravenously. MSC-treated animals presented the lowest serum creatinine compared to non-treated animals (24 h: 1.3 +/- 0.21 vs. 3.23 +/- 0.89 mg/dl, p<0.05). The improvement in renal function was followed by a lower expression of IL-1b, IL-6 and TNF-alpha and higher expression of IL-4 and IL-10. However, 48 h after reperfusion, this cytokine profile has changed. The decrease in Th1 cytokines was less evident and IL-6 was markedly up regulated. PCNA analysis showed that regeneration occurs faster in kidney tissues of MSC-treated animals than in controls at 24 h. And also ratio of Bcl-2/Bad was higher at treated animals after 24 and 48 h. Our data demonstrated that the immunomodulatory effects of MSC occur at very early time point, changing the inflammation profile toward a Th2 profile. (C) 2009 Elsevier B.V. All rights reserved.

INSULIN REGULATES CYTOKINES AND INTERCELLULAR ADHESION MOLECULE-1 GENE EXPRESSION THROUGH NUCLEAR FACTOR-kappa B ACTIVATION IN LPS-INDUCED ACUTE LUNG INJURY IN RATS

Diabetic patients have increased susceptibility to infection, which may be related to impaired inflammatory response observed in experimental models of diabetes, and restored by insulin treatment. The goal of this study was to investigate whether insulin regulates transcription of cytokines and intercellular adhesion molecule 1 (ICAM-1) via nuclear factor-kappa B (NF-kappa B) signaling pathway in Escherichia coli LIPS-induced lung inflammation. Diabetic male Wistar rats (alloxan, 42 mg/kg, iv., 10 days) and controls were instilled intratracheally with saline containing LPS (750 mu g/0.4 mL) or saline only. Some diabetic rats were given neutral protamine Hagedorn insulin (4 IU, s.c.) 2 h before LIPS. Analyses performed 6 h after LPS included: (a) lung and mesenteric lymph node IL-1 beta, TNF-alpha, IL-10, and ICAM-1 messenger RNA (mRNA) were quantified by real-time reverse transcriptase-polymerase chain reaction; (b) number of neutrophils in the bronchoalveolar lavage (BAL) fluid, and concentrations of IL-1 beta, TNF-alpha, and IL-10 in the BAL were determined by the enzyme-linked immunosorbent assay; and (c) activation of NF-kappa B p65 subunit and phosphorylation of I-kappa B alpha were quantified by Western blot analysis. Relative to controls, diabetic rats exhibited a reduction in lung and mesenteric lymph node IL-1 beta (40%), TNF-alpha (similar to 30%), and IL-10 (similar to 40%) mRNA levels and reduced concentrations of IL-1 beta (52%), TNF-alpha (62%), IL-10 (43%), and neutrophil counts (72%) in the BAL. Activation of NF-kappa B p65 subunit and phosphorylation of I-kappa B alpha were almost suppressed in diabetic rats. Treatment of diabetic rats with insulin completely restored mRNA and protein levels of these cytokines and potentiated lung ICAM-1 mRNA levels (30%) and number of neutrophils (72%) in the BAL. Activation of NF-kappa B p65 subunit and phosphorylation of I-kappa B alpha were partially restored by insulin treatment. In conclusion, data presented suggest that insulin regulates transcription of proinflammatory (IL-1 beta, TNF-alpha) and anti-inflammatory (IL-10) cytokines, and expression of ICAM-1 via the NF-kappa B signaling pathway.

Deficiency of thrombospondin-1 reduces Th17 differentiation and attenuates experimental autoimmune encephalomyelitis

Transforming growth factor beta (TGF-beta) plays a role both in the induction of Treg and in the differentiation of the IL-17-secreting T cells (Th17) which drive inflammation in experimental autoimmune encephalomyelitis (EAE). We investigated the role that thrombospondin-1 (TSP-1) dependent activation of TGF-beta played in the generation of an encephalitic Th17 response in EAE. Upon immunization with myelin oligodendrocyte glycoprotein peptide (MOG(35-55)), TSP-1 deficient (TSP-1(null)) mice and MOG(35-55) TCR transgenic mice that lack of TSP-1 (2D2.TSP-1(null)) exhibited an attenuated form of EAE, and secreted lower levels of IL-17. Adoptive transfer of in vitro-activated 2D2.TSP-1(null) T cells induced a milder form of EAE, independent of TSP-1 expression in the recipient mice. Furthermore, in vitro studies demonstrated that anti-CD3/anti-CD28 pre-activated CD4+ T cells transiently upregulated latent TGF-beta in a TSP-1 dependent way, and such activation of latent TGF-beta was required for the differentiation of Th17 cells. These results demonstrate that TSP-1 participates in the differentiation of Th17 cells through its ability to activate latent TGF-beta, and enhances the inflammatory response in EAE. (C) 2009 Elsevier Ltd. All rights reserved.

MyD88 Signaling Is Required for Efficient Innate and Adaptive Immune Responses to Paracoccidioides brasiliensis Infection

The mechanisms that govern the initial interaction between Paracoccidioides brasiliensis, a primary dimorphic fungal pathogen, and cells of the innate immunity need to be clarified. Our previous studies showed that Toll-like receptor 2 (TLR2) and TLR4 regulate the initial interaction of fungal cells with macrophages and the pattern of adaptive immunity that further develops. The aim of the present investigation was to assess the role of MyD88, an adaptor molecule used by TLRs to activate genes of the inflammatory response in pulmonary paracoccidioidomycosis. Studies were performed with normal and MyD88(-/-) C57BL/6 mice intratracheally infected with P. brasiliensis yeast cells. MyD88(-/-) macrophages displayed impaired interaction with fungal yeast cells and produced low levels of IL-12, MCP-1, and nitric oxide, thus allowing increased fungal growth. Compared with wild-type (WT) mice, MyD88(-/-) mice developed a more severe infection of the lungs and had marked dissemination of fungal cells to the liver and spleen. MyD88(-/-) mice presented low levels of Th1, Th2, and Th17 cytokines, suppressed lymphoproliferation, and impaired influx of inflammatory cells to the lungs, and this group of cells comprised lower numbers of neutrophils, activated macrophages, and T cells. Nonorganized, coalescent granulomas, which contained high numbers of fungal cells, characterized the severe lesions of MyD88(-/-) mice; the lesions replaced extensive areas of several organs. Therefore, MyD88(-/-) mice were unable to control fungal growth and showed a significantly decreased survival time. In conclusion, our findings demonstrate that MyD88 signaling is important in the activation of fungicidal mechanisms and the induction of protective innate and adaptive immune responses against P. brasiliensis.

Toll-like receptor 4 agonists adsorbed to aluminium hydroxide adjuvant attenuate ovalbumin-specific allergic airway disease: role of MyD88 adaptor molecule and interleukin-12/interferon-gamma axis

Background Epidemiological and experimental data suggest that bacteria] lipopolysaccharides (LPS) can either protect from or exacerbate allergic asthma. Lipopolysaccharides trigger immune responses through toll-like receptor 4 (TLR4) that in turn activates two major signalling pathways via either MyD88 or TRIF adaptor proteins. The LPS is a pro-Type 1 T helper cells (Th 1) adjuvant while aluminium hydroxide (alum) is a strong Type 2 T helper cells (Th2) adjuvant, but the effect of the mixing of both adjuvants on the development of lung allergy has not been investigated. Objective We determined whether natural (LPS) or synthetic (ER-803022) TLR4 agonists adsorbed onto alum adjuvant affect allergen sensitization and development of airway allergic disease. To dissect LPS-induced molecular pathways, we used TLR4-, MyD88-, TRIF-, or IL-12/IFN-gamma-deficient mice. Methods Mice were sensitized with subcutaneous injections of ovalbumin (OVA) with or without TLR4 agonists co-adsorbed onto alum and challenged with intranasally with OVA. The development of allergic lung disease was evaluated 24 h after last OVA challenge. Results Sensitization with OVA plus LPS co-adsorbed onto alum impaired in dose-dependent manner OVA-induced Th2-mediated allergic responses such as airway eosinophilia, type-2 cytokines secretion, airway hyper-reactivity, mucus hyper production and serum levels of IgE or IgG1 anaphylactic antibodies. Although the levels of IgG2a, Th1 -affiliated isotype increased, investigation into the lung-specific effects revealed that LPS did not induce a Th1 pattern of inflammation. Lipopolysaccharides impaired the development of Th2 immunity, signaling via TLR4 and MyD88 molecules and via the IL-12/IFN-gamma axis, but not through TRIF pathway. Moreover, the synthetic TLR4 agonists that proved to have a less systemic inflammatory response than LPS also protected against allergic asthma development. Conclusion Toll-like receptor 4 agonists co-adsorbed with allergen onto alum down-modulate allergic lung disease and prevent the development of polarized T cell-mediated airway inflammation.

A Role for galectin-3 in renal tissue damage triggered by ischemia and reperfusion injury

Ischemic-reperfusion injury (IRI) triggers an inflammatory response involving neutrophils/macrophages, lymphocytes and endothelial cells. Galectin-3 is a multi-functional lectin with a broad range of action such as promotion of neutrophil adhesion, induction of oxidative stress, mastocyte migration and degranulation, and production of pro-inflammatory cytokines. The aim of this study was evaluate the role of galectin-3 in the inflammation triggered by IRI. Galectin-3 knockout (KO) and wild type (wt) mice were subjected to 45 min of renal pedicle occlusion. Blood and kidney samples were collected at 6, 24, 48 and 120 h. Blood urea was analyzed enzymatically, while MCP-1, IL-6 and IL-1 beta were studied by real-time PCR. Reactive oxygen species (ROS) was investigated by flow cytometry. Morphometric analyses were performed at 6, 24, 48 and 120 h after reperfusion. Urea peaked at 24 h, being significantly lower in knockout animals (wt = 264.4 +/- 85.21 mg/dl vs. gal-3 KO = 123.74 +/- 29.64 mg/dl, P = 0.001). Galectin-3 knockout animals presented less acute tubular necrosis and a more prominent tubular regeneration when compared with controls concurrently with lower expression of MCP-1, IL-6, IL-1 beta, less macrophage infiltration and lower ROS production at early time points. Galectin-3 seems to play a role in renal IRI involving the secretion of macrophage-related chemokine, pro-inflammatory cytokines and ROS production.

Differential effects of female sex hormones on cellular recruitment and tracheal reactivity after formaldehyde exposure

Female sex hormones (FSHs) exert profound regulatory effects on the course of lung inflammation due to allergic and non-allergic immune responses. As pollution is one of the pivotal factors to induce lung dysfunction, in this study we investigated the modulatory role of FSHs on lung inflammation after a formaldehyde (FA) exposure. For this purpose, lung and systemic inflammatory responses were evaluated in terms of leukocytes countings in bronchoalveolar lavage (BAL), peripheral blood and bone marrow lavage from 7-day ovariectomized (OVx) and Sham-OVx rats subjected to FA inhalation for 3 consecutive days. The hypothesized link between effects of FSHs on expression of adhesion molecules and mast cells degranulation was also studied. Once exposed to FA, Sham-OVx rats increased the number of total cells recovered in BAL and of leukocytes in peripheral blood, and decreased the counts in bone marrow. By contrast, in OVx rats upon FA exposure there was a reduction of the total cells counts in BAL and of blood leukocytes: lung expressions of ICAM-1 and Mac-1 were depressed, but the number of bone marrow cells did not vary. Estradiol treatment of OVx rats increased the total cells in BAL and decreased the number of blood leukocytes, whereas the number of bone marrow cell remained unaltered. Progesterone treatment, in turn increased the total cells in BAL and blood leukocytes, but decreased the number of bone marrow cells. OVx rats exposed to FA developed tracheal hyperresponsiveness to methacholine (MCh). A similarly altered response was found between the tracheal segments of Sham-OVx rats after FA exposure and that found in tracheae of naive rats. Estradiol treatment prevented FA-induced tracheal hyperresponsiveness to MCh whereas progesterone was ineffective in this regard. In addition, OVx rats upon FA exposure significantly increased both, the ability of mast cell degranulation and serum corticosterone levels. In conclusion, it was found that FSHs act by distinct control mechanisms on FA-induced lung inflammation and tracheal hyperresponsiveness, since at low circulating levels of FSHs (such as those after OVx) there is some resistance to the development of a lung inflammatory response, but the cholinergic tracheal responsiveness is exacerbated. Our data also help to understand the involvement of FSHs on mast cells activity after pollutants exposure and add information regarding the role of FSHs on the mechanisms related to endothelium-leukocyte interactions. (C) 2011 Elsevier Ireland Ltd. All rights reserved.

Bradykinin inducible receptor is essential to lipopolysaccharide-induced acute lung injury in mice

Lipopolysaccharides from gram-negative bacteria are amongst the most common causative agents of acute lung injury, which is characterized by an inflammatory response, with cellular infiltration and the release of mediators/cytokines. There is evidence that bradykinin plays a role in lung inflammation in asthma but in other types of lung inflammation its role is less clear. In the present study we evaluated the role of the bradykinin B(1) receptor in acute lung injury caused by lipopolysaccharide inhalation and the mechanisms behind bradykinin actions participating in the inflammatory response. We found that in C57BI/6 mice, the bradykinin B(1) receptor expression was up-regulated 24 h after lipopolysaccharide inhalation. At this time, the number of cells and protein concentration were significantly increased in the bronchoalveolar lavage fluid and the mice developed airway hyperreactivity to methacholine. In addition, there was an increased expression of tumor necrosis factor-alpha, interleukin-1 beta and interferon-gamma and chemokines (monocytes chemotactic protein-1 and KC) in the bronchoalveolar lavage fluid and in the lung tissue. We then treated the mice with a bradykinin B, receptor antagonist, R-954 (Ac-Orn-[Oic(2), alpha-MePhe(5), D-beta Nal(7), Ile(8)]desArg(9)-bradykinin), 30 min after lipopolysaccharide administration. We observed that this treatment prevented the airway hyperreactivity as well as the increased cellular infiltration and protein content in the bronchoalveolar lavage fluid. Moreover, R-954 inhibited the expression of cytokines/chemokines. These results implicate bradykinin, acting through B(1) receptor, in the development of acute lung injury caused by lipopolysaccharide inhalation. (C) 2010 Elsevier B.V. All rights reserved.

SIGNALING PATHWAYS AND MEDIATORS IN LPS-INDUCED LUNG INFLAMMATION IN DIABETIC RATS: ROLE OF INSULIN

Diabetic patients are more susceptible to infections, and their inflammatory response is impaired. This is restored by insulin treatment. In the present study, we investigated the effect of insulin on LPS-induced signaling pathways and mediators in the lung of diabetic rats. Diabetic male Wistar rats (alloxan, 42 mg/kg i.v., 10 days) and control rats received intratracheal instillation of LPS (750 mu g/0.4 mL) or saline. Some diabetic rats were given neutral protamine Hagedorn insulin (4 IU s.c.) 2 h before LPS. After 6 h, bronchoalveolar lavage was performed for the release of mediators, and lung tissue was homogenized for analysis of LPS-induced signaling pathways. Relative to control rats, diabetic rats exhibited a significant reduction in the LPS-induced phosphorylation of extracellular signal-regulated kinase (64%), p38 (70%), protein kinase B (67%), and protein kinase C alpha (57%) and delta (65%) and in the expression of iNOS (32%) and cyclooxygenase 2 (67%) in the lung homogenates. The bronchoalveolar lavage fluid concentrations of NO (47%) and IL-6 (49%) were also reduced in diabetic rats, whereas the cytokine-induced neutrophil chemoattractant 2 (CINC-2) levels were increased 23%, and CINC-1 was not different from control animals. Treatment of diabetic rats with insulin completely or partially restored all these parameters. In conclusion, data presented show that insulin regulates mitogen-activated protein kinase, phosphatidylinositol 3`-kinase, protein kinase C pathways, expression of the inducible enzymes, cyclooxygenase 2 and iNOS, and levels of IL-6 and CINC-2 in LPS-induced lung inflammation in diabetic rats. These results suggest that the protective effect of insulin in sepsis could be due to modulation of cellular signal transduction factors.

Preventive and curative glycoside kaempferol treatments attenuate the TH2-driven allergic airway disease

Asthma is a chronic respiratory disease characterized by airway inflammation and airway hyperresponsiveness (AHR). One strategy to treat allergic diseases is the development of new drugs. Flavonoids are compounds derived from plants and are known to have antiallergic, anti-inflammatory, and antioxidant properties. To investigate whether the flavonoid kaempferol glycoside 3-O-[beta-D-glycopiranosil-(1 -> 6)-alpha-L-ramnopiranosil]-7-O-alpha-L-ramnopiranosil-kaempferol (GRRK) would be capable of modulating allergic airway disease (AAD) either as a preventive (GRRK P) or curative (GRRK C) treatment in an experimental model of asthma. At weekly intervals, BALB/c mice were subcutaneously (sc) sensitized twice with ovalbumin (OVA)/alum and challenged twice with OVA administered intranasally. To evaluate any preventive effects GRRK was administered 1 h (hour) before each OVA-sensitization and challenge, while to analyze the curative effects mice were first sensitized with OVA, followed by GRRK given at day 18 through 21. The onset: of AAD was evaluated 24 h after the last OVA challenge. Both treatments resulted in a dose-dependent reduction in total leukocyte and eosinophil counts in the bronchoalveolar lavage fluid (BAL). GRRK also decreased CD4(+), B220(+), MHC class II and CD40 molecule expressions in BAL cells. Histology and lung mechanic showed that GRRK suppressed mucus production and ameliorated the AHR induced by OVA challenge. Furthermore, GRRK impaired Th2 cytokine production (IL-5 and IL-13) and did not induce a Th1 pattern of inflammation. These findings demonstrate that GRRK treatment before or after established allergic lung disease down-regulates key asthmatic features. Therefore. GRRK has a potential clinical use for the treatment of allergic asthma. (C) 2009 Elsevier B.V. All rights reserved.