Crystal structure at 1.1 angstrom resolution of alpha-conotoxin PnIB: Comparison with alpha-conotoxins PnIA and GI

Conotoxins are small, cysteine-rich peptides isolated from the venom of Conus spp. of predatory marine snails, which selectively target specific receptors and ion channels critical to the functioning of the neuromuscular system. alpha-Conotoxins PnIA and PnIB are both 16-residue peptides (differing in sequence at only two positions) isolated from the molluscivorous snail Conus pennaceus. In contrast to the muscle-selective alpha-conotoxin GI from Conus geographus, PnIA and PnIB block the neuronal nicotinic acetylcholine receptor (nAChR). Here, we describe the crystal structure of PnIB, solved at a resolution of 1.1 Angstrom and phased using the Shake-and-Bake direct methods program. PnIB crystals are orthorhombic and belong to the space group P2(1)2(1)2(1) with the following unit cell dimensions: a = 14.6 Angstrom, b = 26.1 Angstrom, and c = 29.2 Angstrom. The final refined structure of alpha-conotoxin PnIB includes all 16 residues plus 23 solvent molecules and has an overall R-factor of 14.7% (R-free of 15.9%). The crystal structures of the alpha-conotoxins PnIB and PnIA are solved from different crystal forms, with different solvent contents. Comparison of the structures reveals them to be very similar, showing that the unique backbone and disulfide architecture is not strongly influenced by crystal lattice constraints or solvent interactions. This finding supports the notion that this structural scaffold is a rigid support for the presentation of important functional groups. The structures of PnIB and PnIA differ in their shape and surface charge distribution from that of GI.

Pharmacodynamics of PEG-IFN-alpha-2a and HCV Response as a Function of IL28B Polymorphism in HIV/HCV-Coinfected Patients

We examined the association between IL28B single-nucleotide polymorphism rs12979860, hepatitis C virus (HCV) kinetic, and pegylated interferon alpha-2a pharmacodynamic parameters in HIV/HCV-coinfected patients from South America. Twenty-six subjects received pegylated interferon alpha-2a + ribavirin. Serum HCV-RNA and interferon concentrations were measured frequently during the first 12 weeks of therapy and analyzed using mathematical models. African Americans and whites had a similar distribution of IL28B genotypes (P = 0.5). The IL28B CC genotype was overrepresented (P = 0.015) in patients infected with HCV genotype-3 compared with genotype-1. In both genotype-1 and genotype-3, the first-phase viral decline and the average pegylated interferon-alpha-2a effectiveness during the first week of therapy were larger (trend P <= 0.12) in genotype-CC compared with genotypes-TC/TT. In genotype-1 patients, the second slower phase of viral decline (days 2-29) and infected cells loss rate, delta, were larger (P = 0.02 and 0.11, respectively) in genotype-CC than in genotypes-TC/TT. These associations were not observed in genotype-3 patients.

Increased soluble TNF receptor 2 in antidepressant-free patients with late-life depression

Increased pro-inflammatory state has been implicated in the pathophysiology of major depressive disorder. The aim of this study was to determine serum levels of INF-alpha and soluble TNF-alpha receptors 1 and 2 (sTNFR1 and sTNFR2) in anti-depressant free depressed elderly patients as compared to healthy controls. Sixty-seven older adults (28 with major depression and 39 controls) were enrolled to this study. Participants were assessed by the SCID and diagnosis of major depressive episode was made according to the DSM-IV criteria. Serum INF-alpha, 5TNFR1 and sTNFR2 were determined by ELISA. Anti-depressant free patients with late-life depression showed an increased level of the sTNFR2 as compared to controls (p = 0.03). No significant differences were found in serum INF-alpha and sTNFR1 levels (p = 0.1 and p = 0.4, respectively). There was no correlation between serum levels of these inflammatory markers and the severity of depression. Our findings provide additional evidence of the involvement of abnormal pro-inflammatory state in late-life depression. (c) 2010 Elsevier Ltd. All rights reserved.

alpha-Melanocyte Stimulating Hormone Analogue AP214 Protects Against Ischemia Induced Acute Kidney Injury in a Porcine Surgical Model

Purpose: alpha-Melanocyte stimulating hormone protects kidneys against ischemia and sepsis induced acute kidney injury in rodents. We examined the efficacy of a-melanocyte stimulating hormone analogue AP214 to protect against acute kidney injury in higher vertebrates. Materials and Methods: We performed a prospective, blinded, randomized, placebo controlled study in 26 pigs. Laparoscopic technique was used for left nephrectomy and to induce complete warm ischemia in the right kidney for 120 minutes. AP214 (200 mu g/kg intravenously) was administered daily on the day of surgery and for 5 days thereafter. Kidney function was measured for 9 days. We measured changes in serum creatinine, estimated glomerular filtration rate, serum C-reactive protein and urine interleukin-18. Results: In the placebo control and AP214 groups mean peak serum creatinine was 10.2 vs 3.92 mg/dl and the estimated glomerular filtration rate nadir was 22.9 vs 62.6 ml per minute per kg (each p = 0.001). Functional nadir occurred at 72 vs 24 hours in the control vs AP214 groups. Estimated glomerular filtration rate outcome on postoperative day 9 was 118 vs 156 ml per minute per kg in the control vs AP214 groups (p = 0.04). Conclusions: We noted a robust renoprotective effect of AP214. A similar AP214 effect may be observed in humans. Future research includes mechanistic studies in pigs and a phase II human clinical trial of AP214 in kidney transplant and partial nephrectomy populations.

CO(2) Abdominal Insufflation Decreases Local and Systemic Inflammatory Response in Experimental Acute Pancreatitis

Objectives: Acute pancreatitis (AP) is a serious disease that is amplified by an associated systemic inflammatory response. We investigated the effect of CO(2) pneumoperitoneum on the local and systemic inflammatory response in AP. Methods: Acute pancreatitis was induced in Wistar rats by 5% taurocholate intraductal injection. Carbon dioxide pneumoperitoneum was applied for 30 minutes before the induction of AP. Inflammatory parameters were evaluated in the peritoneum (ascites, cell number, and tumor necrosis factor alpha [TNF-alpha]), serum (amylase, TNF-alpha, interleukin-6 [IL-6], and IL-10), pancreas (myeloperoxidase [MPO] activity, cyclooxygenase 2 and inducible nitric oxide synthase expression, and histological diagnosis), liver, and lung (mitochondria dysfunction and MPO activity). Results: Abdominal insufflation with CO(2) before induction of AP caused a significant decrease in ascites volume, cells, and TNF-alpha in the peritoneal cavity and in serum TNF-alpha and IL-6 but not IL-10 levels. In the pancreas, this treatment reduced MPO activity, acinar and fat necrosis, and the expression of inducible nitric oxide synthase and cyclooxygenase 2. There were no significant differences on serum amylase levels, liver mitochondrial function, and pulmonary MPO between groups. Conclusions: Our data demonstrated that CO(2) pneumoperitoneum reduced pancreatic inflammation and attenuated systemic inflammatory response in AP. This article suggests that CO(2) pneumoperitoneum plays a critical role on the better outcome in patients undergoing laparoscopic pancreatic surgery.

Changes in slow and fast alpha bands in subjects submitted to different amounts of functional electrostimulation

Objective: To examine the changes in slow (8-10 Hz)and fast (10-12 Hz) alpha bands of EEG in three groups of subjects submitted to different amounts of functional electrostimulation (FES). Our hypothesis is that different amounts of electrostimulation may cause different patterns of activation in the sensorimotor cortex. In particular, we expect to see an increase in alpha power due to habituation effects. We examine the two bands comprised by alpha rhythm (i.e., slow and fast alpha), since these two sub-rhythms are related to distinct aspects: general energy demands and specific motor aspects, respectively. Methods: The sample was composed of 27 students, both sexes, aging between 25 and 40 years old. The subjects were randomly distributed in three groups: control (n = 9), G24 (n = 9) and G36 (n = 9). A FES equipment (Neuro Compact-2462) was used to stimulate the right index finger extension. Simultaneously, the electroencephalographic signal was acquired. We investigated the absolute power in slow and fast alpha bands in the sensorimotor cortex. Results: The G36 indicated a significant increasing in absolute power values in lower and higher alpha components, respectively, when compared with the control group. Particularly, in the following regions: pre-motor cortex and primary motor cortex. Discussion: FES seems to promote cortical adaptations that are similar to those observed when someone learns a procedural task. FES application in the G36 was more effective in promoting such neural changes. The lower and higher components of alpha rhythms behave differently in their topographical distribution during FES application. These results suggest a somatotopic organization in primary motor cortex which can be represented by the fast alpha component. (C) 2008 Elsevier Ireland Ltd. All rights reserved.

Debaryomyces hansenii UFV-1 Intracellular alpha-Galactosidase Characterization and Comparative Studies with the Extracellular Enzyme

Debaryomyces hansenii cells cultivated on galactose produced extracellular and intracellular alpha-galactosidases, which showed 54.5 and 54.8 kDa molecular mass (MALDI-TOF), 60 and 61 kDa (SDS-PAGE) and 5.15 and 4.15 pI values, respectively. The extracellular and intracellular deglycosylated forms presented 36 and 40 kDa molecular mass, with 40 and 34% carbohydrate content, respectively. The N-terminal sequences of the alpha-galactosidases were identical. Intracellular alpha-galactosidase showed smaller thermostability when compared to the extracellular enzyme. D. hansenii UFV-1 extracellular alpha-galactosidase presented higher k(cat) than the intracellular enzyme (7.16 vs 3.29 s(-1), respectively) for the p-nitrophenyl-alpha-D-galactopyranoside substrate. The K(m) for hydrolysis of pNP alpha Gal, melibiose, stachyose, and raffinose were 0.32, 2.12, 10.8, and 32.8 mM, respectively. The intracellular enzyme was acompetitively inhibited by galactose (K(i) = 0.70 mM), and it was inactivated by Cu(II) and Ag(I). Enzyme incubation with soy milk for 6 h at 55 degrees C reduced stachyose and raffinose amounts by 100 and 73%, respectively.

The macrophage-derived neutrophil chemotactic factor, MNCF: A lectin with TNF-alpha-like activities on neutrophils

The macro phage-derived neutrophil chemotactic factor (MNCF) is an alpha-galactoside-binding lectin, known to induce dexamethasone-insensitive neutrophil recruitment. We further characterized MNCF effects on neutrophils and showed that it shares with TNF-alpha the ability to delay apoptosis and to trigger degranulation. MNCF and TNF-alpha effects show similar kinetics and involve Src kinases and MAPKinases dependent pathways. They were, however, clearly distinguished, since the soluble TNF-receptor etanercept prevented TNF but not MNCF effects, while melibiose disaccharide inhibited MNCF but not TNF effects. Absorption of MNCF on detoxi-gel did not alter its properties, precluding an LPS contamination effect. By contrast, galectin-3 required LPS to activate neutrophils. Specific antibodies allowed to further demonstrate that MNCF and galectin-3 are two distinct molecules. Finally, MNCF- and IL-8-induced neutrophil activation differed by their kinetic and sensitivity to pertussis toxin. In conclusion, MNCF is a distinct neutrophil agonist, with pro-inflammatory activities involving its carbohydrate recognition domain. (C) 2008 Elsevier Inc. All rights reserved.

Effect of the glycemic control on intracellular cytokine production from peripheral blood mononuclear cells of type 1 and type 2 diabetic patients

Aims: To evaluate the intracellular production of tumor necrosis factor (TNF-alpha), interleukine-6 (IL-6), INF-gamma, IL-8 and IL-10 in peripheral blood lympbomononuclear cells from type 1 and type 2 diabetic patients, stratified according to the glycemic control. Methods: Thirty-five diabetic patients (17 type 1 and 18 type 2) and nine healthy individuals paired to patients in terms of sex and age were studied. Nine patients of each group were on inadequate glycemic controls. Intracellular cytokines were evaluated using flow cytometry. Cell cultures were stimulated with LPS to evaluate TNF-alpha and IL-6 or with PMA and lonomycin to evaluate IFN-gamma, IL-8 and IL-10 intracellular staining. Results: The percentages of CD33(+) cells bearing TNF-alpha and CD3(+) cells bearing IL-10 were increased in type 1 diabetic patients with inadequate glycemic control in relation to those with adequate control. In contrast, the percentage of CD3(+) cells bearing IL-8 was decreased in type 2 patients under inadequate glycemic control. Conclusions: The glycemic control is important for the detection of intracellular cytokines, and may contribute towards the susceptibility to infections in diabetic patients. (c) 2008 Elsevier Ireland Ltd. All rights reserved.

Crucial Role of TNF Receptors 1 and 2 in the Control of Polymicrobial Sepsis

Sepsis is still a major cause of mortality in the intensive critical care unit and results from an overwhelming immune response to the infection. TNF signaling pathway plays a central role in the activation of innate immunity in response to pathogens. Using a model of polymicrobial sepsis by i.p. injection of cecal microflora, we demonstrate a critical role of TNFR1 and R2 activation in the deregulated immune responses and death associated with sepsis. A large and persistent production of TNF was found in wild-type (B6) mice. TNFR1/R2-deficient mice, compared with B6 mice, survive lethal polymicrobial infection with enhanced neutrophil recruitment and bacterial clearance in the peritoneal cavity. Absence of TNFR signaling leads to a decreased local and systemic inflammatory response with diminished organ injury. Furthermore, using TNFR1/R2-deficient mice, TNF was found to be responsible for a decrease in CXCR2 expression, explaining reduced neutrophil extravasation and migration to the infectious site, and in neutrophil apoptosis. In line with the clinical experience, administration of Enbrel, a TNF-neutralizing protein, induced however only a partial protection in B6 mice, with no improvement of clinical settings, suggesting that future TNF immunomodulatory strategies should target TNFR1 and R2. In conclusion, the present data suggest that the endogenous TNFR1/R2 signaling pathway in polymicrobial sepsis reduces neutrophil recruitment contributing to mortality and as opposed to pan-TNF blockade is an important therapeutic target for the treatment of polymicrobial sepsis. The Journal of Immunology, 2009, 182: 7855-7864.

TNF-alpha Infusion Impairs Corpora Cavernosa Reactivity

Introduction. Erectile dysfunction (ED), as well as cardiovascular diseases (CVDs), is associated with endothelial dysfunction and increased levels of proinflammatory cytokines, such as tumor necrosis factor-alpha (TNF-alpha). Aim. We hypothesized that increased TNF-alpha levels impair cavernosal function. Methods. In vitro organ bath studies were used to measure cavernosal reactivity in mice infused with vehicle or TNF-alpha-(220 ng/kg/min) for 14 days. Gene expression of nitric oxide synthase isoforms was evaluated by real-time polymerase chain reaction. Results. Cavernosal strips from the TNF-alpha-infused mice displayed decreased nonadrenergic-noncholinergic (NANC)-induced relaxation (59.4 +/- 6.2 vs. control: 76.2 +/- 4.7; 16 Hz) compared with the control animals. These responses were associated with decreased gene expression of eNOS and nNOS (P < 0.05). Sympathetic-mediated, as well as phenylephrine (PE)-induced, contractile responses (PE-induced contraction; 1.32 +/- 0.06 vs. control: 0.9 +/- 0.09, mN) were increased in cavernosal strips from TNF-alpha-infused mice. Additionally, infusion of TNF-alpha increased cavernosal responses to endothelin-1 and endothelin receptor A subtype (ET(A)) receptor expression (P < 0.05) and slightly decreased tumor necrosis factor-alpha receptor 1 (TNFRI) expression (P=0.063). Conclusion. Corpora cavernosa from TNF-alpha-infused mice display increased contractile responses and decreased NANC nerve-mediated relaxation associated with decreased eNOS and nNOS gene expression. There changes may trigger ED and indicate that TNF-alpha plays a detrimental role in erectile function. Blockade of TNF-alpha actions may represent an alternative therapeutic approach for ED, especially in pathologic conditions associated with increased levels of this cytokine. Carneiro FS, Zemse S, Giachini FRC, Carneiro ZN, Lima W, Clinton Webb R, and Tostes RC. TNF-alpha infusion impairs corpora cavernosa reactivity. J Sex Med 2009;6(suppl 3):311-319.

Factors involved in the T helper type 1 and type 2 cell commitment and osteoclast regulation in inflammatory apical diseases

Periapical chronic lesion formation involves activation of the immune response and alveolar bone resorption around the tooth apex. However, the overall roles of T helper type 1 (Th1), Th2, and T-regulatory cell (Treg) responses and osteoclast regulatory factors in periapical cysts and granulomas have not been fully determined. This study aimed to investigate whether different forms of apical periodontitis, namely cysts and granulomas, show different balances of Th1, Th2 regulators, Treg markers, and factors involved in osteoclast chemotaxis and activation. Gene expression of these factors was assessed using quantitative real-time polymerase chain reaction, in samples obtained from healthy gingiva (n = 8), periapical granulomas (n = 20), and cysts (n = 10). Periapical cysts exhibited a greater expression of GATA-3, while a greater expression of T-bet, Foxp3, and interleukin-10 (IL-10) was seen in granulomas. The expression of interferon-gamma, IL-4, and transforming growth factor-beta was similar in both lesions. Regarding osteoclastic factors, while the expression of SDF-1 alpha/CXCL12 and CCR1 was higher in cysts, the expression of RANKL was significantly higher in granulomas. Both lesions exhibited similar expression of CXCR4, CK beta 8/CCL23, and osteoprotegerin, which were significantly higher than in control. Our results showed a predominance of osteoclast activity in granulomas that was correlated with the Th1 response. The concomitant expression of Treg cell markers suggests a possible suppression of the Th1 response in granulomas. On the other hand, in cysts the Th2 activity is augmented. The mechanisms of periradicular lesion development are still not fully understood but the imbalance of immune and osteoclastic cell activity in cysts and granulomas seems to be critically regulated by Treg cells.

TNF-alpha Knockout Mice Have Increased Corpora Cavernosa Relaxation

Erectile dysfunction is considered an early clinical manifestation of vascular disease and an independent risk factor for cardiovascular events associated with endothelial dysfunction and increased levels of pro-inflammatory cytokines. Tumor necrosis factor-alpha (TNF-alpha), a pro-inflammatory cytokine, suppresses endothelial nitric oxide synthase (eNOS) expression. Considering that nitric oxide (NO) is of critical importance in penile erection, we hypothesized that blockade of TNF-alpha actions would increase cavernosal smooth muscle relaxation. In vitro organ bath studies were used to measure cavernosal reactivity in wild type and TNF-alpha knockout (TNF-alpha KO) mice and NOS expression was evaluated by western blot. In addition, spontaneous erections (in vivo) were evaluated by videomonitoring the animals (30 minutes). Collagen and elastin expression were evaluated by Masson trichrome and Verhoff-van Gieson stain reaction, respectively. Corpora cavernosa from TNF-alpha KO mice exhibited increased NO-dependent relaxation, which was associated with increased eNOS and neuronal NOS (nNOS) cavernosal expression. Cavernosal strips from TNF-alpha KO mice displayed increased endothelium-dependent (97.4 +/- 5.3 vs. Control: 76.3 +/- 6.3, %) and nonadrenergic-noncholinergic (93.3 +/- 3.0 vs. Control: 67.5 +/- 16.0; 16 Hz) relaxation compared to control animals. These responses were associated with increased protein expression of eNOS and nNOS (P < 0.05). Sympathetic-mediated (0.69 +/- 0.16 vs. Control: 1.22 +/- 0.22; 16 Hz) as well as phenylephrine-induced contractile responses (1.6 +/- 0.1 vs. Control: 2.5 +/- 0.1, mN) were attenuated in cavernosal strips from TNF-alpha KO mice. Additionally, corpora cavernosa from TNF-alpha KO mice displayed increased collagen and elastin expression. In vivo experiments demonstrated that TNF-alpha KO mice display increased number of spontaneous erections. Corpora cavernosa from TNF-alpha KO mice display alterations that favor penile tumescence, indicating that TNF-alpha plays a detrimental role in erectile function. A key role for TNF-alpha in mediating endothelial dysfunction in ED is markedly relevant since we now have access to anti-TNF-alpha therapies. Carneiro FS, Sturgis LC, Giachini FRC, Carneiro ZN, Lima VV, Wynne BM, Martin SS, Brands MW, Tostes RC, and Webb RC. TNF-alpha knockout mice have increased corpora cavernosa relaxation. J Sex Med 2009;6:115-125.

Phlebotomine salivas inhibit immune inflammation-induced neutrophil migration via an autocrine DC-derived PGE(2)/IL-10 sequential pathway

In the present study, we investigated whether saliva from Phlebotomus papatasi and Phlebotomus duboscqi inhibited antigen-induced neutrophil migration and the mechanisms involved in these effects. The pretreatment of immunized mice with salivary gland extracts (SGE) of both phlebotomines inhibited OVA challenge-induced neutrophil migration and release of the neutrophil chemotactic mediators, MIP-1 alpha, TNF-alpha, and leukotriene B-4 (LTB4). Furthermore, SGE treatment enhanced the production of anti-inflammatory mediators, IL-10 and PGE(2). SGE treatments failed to inhibit neutrophil migration and MIP-1 alpha and LTB4 production in IL-10(-/-) mice, also failing in mice treated with nonselective (indomethacin) or selective (rofecoxibe) cyclooxygenase (COX) inhibitors. COX inhibition resulted in diminished SGE-induced IL-10 production, and PGE(2) release triggered by SGE remained increased in IL-10(-/-) mice, suggesting that prostanoids are acting through an IL-10-dependent mechanism. SGE treatments in vivo reduced the OVA-induced lymphoproliferation of spleen-derived cells. Further, the in vitro incubation of bone marrow-derived dendritic cells (DC) with SGE inhibited the proliferation of CD4(+) T cells from OVA-immunized mice, which was reversed by indomethacin and anti-IL-10 antibody treatments. Supporting these results, SGE induced the production of PGE(2) and IL-10 by DC, which were blocked by COX inhibition. These effects were associated with the reduction of DC-membrane expression of MHC-II and CD86 by SGE treatment. Altogether, the results showed that Phlebotomine saliva inhibits immune inflammation-induced neutrophil migration by an autocrine DC sequential production of PGE(2)/IL-10, suggesting that the saliva constituents might be promising therapeutic molecules to target immune inflammatory diseases.

Increased activities of cardiac matrix metalloproteinases matrix metalloproteinase (MMP)-2 and MMP-9 are associated with mortality during the acute phase of experimental Trypanosoma cruzi infection

The strong inflammatory reaction that occurs in the heart during the acute phase of Trypanosoma cruzi infection is modulated by cytokines and chemokines produced by leukocytes and cardiomyocytes. Matrix metalloproteinases (MMPs) have recently emerged as modulators of cardiovascular inflammation. In the present study we investigated the role of MMP-2 and MMP-9 in T. cruzi-induced myocarditis, by use of immunohistochemical analysis, gelatin zymography, enzyme-linked immunosorbent assay, and real-time polymerase chain reaction to analyze the cardiac tissues of T. cruzi-infected C57BL/6 mice. Increased transcripts levels, immunoreactivity, and enzymatic activity for MMP-2 and MMP-9 were observed by day 14 after infection. Mice treated with an MMP inhibitor showed significantly decreased heart inflammation, delayed peak in parasitemia, and improved survival rates, compared with the control group. Reduced levels of cardiac tumor necrosis factor-alpha, interferon-gamma, serum nitrite, and serum nitrate were also observed in the treated group. These results suggest an important role for MMPs in the induction of T. cruzi-induced acute myocarditis.