Brainstem levels of transcription factor AP-2 in rat are changed after treatment with phenelzine, but not with citalopram

BACKGROUND: Before therapeutic effect is obtained after treatment with antidepressant drugs, like serotonin selective reuptake inhibitors (SSRIs), tricyclic antidepressants (TCAs) and monoamine oxidase inhibitors (MAO-Is) there is an initial lag-period of a few weeks. Neuronal adaptations on a molecular level are supposed to be involved in the initiation of the antidepressant effect. Transcription factor AP-2 is essential for neuronal development and many genes involved in the brainstem monoaminergic systems have binding sites for AP-2 in their regulatory regions. The genotype of the AP-2β isoform has been associated with e.g. anxiety-related personality traits and with platelet MAO activity. In addition, previous studies have shown that the levels of AP-2α and AP-2β in rat whole brain were decreased after 10 days of treatment with citalopram (SSRI) and imipramine (TCA), and were increased with phenelzine (MAO-I). RESULTS: In the present study, we report that treatment with citalopram for 1, 7 or 21 days did not have effect on the AP-2 levels in rat brainstem. However, after treatment with phenelzine for 1, 7 or 21 days the levels of AP-2α and AP-2β had increased after 7 days, but had returned to control levels at day 21. CONCLUSION: The decrease in AP-2 levels in rat whole brain previously seen after treatment with citalopram does not seem to be localised to the brainstem, it may rather occur in the monoaminergic terminal projection areas. The present data suggest that the increase in AP-2 levels previously seen in rat whole brain after subchronic treatment with phenelzine is located in the brainstem. It cannot, however, be excluded that other brain regions are involved

Does the transcription factor AP-2β have an impact on the genetic and early environmental influence on ethanol consumption?

Genes involved in alcoholism have consensus sites for the transcription factor activator protein (TFAP) 2β. In the present study, we investigated TFAP-2β protein levels in the ethanol-preferring alko, alcohol (AA) and the ethanol-avoiding alko, non-alcohol (ANA) rat lines. Furthermore, basal and ethanol-induced TFAP-2β levels were examined in Wistar rats exposed to different early postnatal environments that are known to affect later ethanol consumption. Taken together, we found differences in brainstem TFAP-2β protein between the AA and ANA rats

Bordetella pertussis Autotransporter Vag8 Binds Human C1 Esterase Inhibitor and Confers Serum Resistance

Bordetella pertussis employs numerous strategies to evade the immune system, including the ability to resist killing via complement. Previously we have shown that B. pertussis binds a complement regulatory protein, C1 esterase inhibitor (C1inh) to its surface in a Bvg-regulated manner (i.e. during its virulence phase), but the B. pertussis factor was not identified. Here we set out to identify the B. pertussis C1inh-binding factor. Using a serum overlay assay, we found that this factor migrates at approximately 100 kDa on an SDS-PAGE gel. To identify this factor, we isolated proteins of approximately 100 kDa from wild type strain BP338 and from BP347, an isogenic Bvg mutant that does not bind C1inh. Using mass spectrometry and bioinformatics, we identified the autotransporter protein Vag8 as the putative C1inh binding protein. To prove that Vag8 binds C1inh, vag8 was disrupted in two different B. pertussis strains, namely BP338 and 18–323, and the mutants were tested for their ability to bind C1inh in a surface-binding assay. Neither mutant strain was capable of binding C1inh, whereas a complemented strain successfully bound C1inh. In addition, the passenger domain of Vag8 was expressed and purified as a histidine-tagged fusion protein and tested for C1inh-binding in an ELISA assay. Whereas the purified Vag8 passenger bound C1inh, the passenger domain of BrkA (a related autotransporter protein) failed to do so. Finally, serum assays were conducted to compare wild type and vag8 mutants. We determined that vag8 mutants from both strains were more susceptible to killing compared to their isogenic wild type counterparts. In conclusion, we have discovered a novel role for the previously uncharacterized protein Vag8 in the immune evasion of B. pertussis. Vag8 binds C1inh to the surface of the bacterium and confers serum resistance

Clinical characteristics of Kawasaki disease with sterile pyuria

PurposeKawasaki disease (KD) is a systemic vasculitis and affects many organ systems. It often presents sterile pyuria, microscopic hematuria, and proteinuria due to renal involvement. The aims of this study were to define clinical characteristics of acute KD patients with pyuria and to analyze meaning of pyuria in KD.MethodsThe medical records and laboratory findings including serum and urine test of 133 patients with KD admitted to Yeungnam University Hospital from March 2006 to December 2010 were reviewed retrospectively.ResultsForty patients had sterile pyuria and their clinical characteristics including age, gender and body weight were not significantly different with those who did not have pyuria. Fever duration after treatment was significantly longer in KD patients with pyuria. Erythrocyte sedimentation rate, C-reactive protein and serum concentration of alanine aminotransferase were significantly higher in patients with pyuria. Hyponatremia and coronary artery lesion were seen more often in patients with pyuria but there was no significant difference. Also serum blood urea nitrogen was significantly higher in KD patients with pyuria. Urine β2-microglobulin was elevated in both patients groups and showed no difference between two groups.ConclusionWe found more severe inflammatory reaction in KD patients with pyuria. We also found elevation of some useful parameters like β2-microglobulin that indicate renal involvement of KD through the urine test. Careful management and follow up will need for KD patients with pyuria and it is necessary in the future to study the specific parameters for renal involvement of KD

Protein–Protein Interactions Essentials: Key Concepts to Building and Analyzing Interactome Networks

8 páginas, 3 figuras, 1 tabla.-- This is an open-access article distributed under the terms of the Creative Commons Attribution License.This work has been supported by funds provided by the Local Government Junta de Castilla y León (JCyL, ref. project: CSI07A09), by the Spanish Ministry of Science and Innovation (MICINN - ISCiii, ref. projects: PI061153 and PS09/00843) and by the European Commission Research Grant PSIMEx (ref. FP7-HEALTH-2007-223411).Peer Reviewe

Binding of C4b-Binding Protein to Porin: A Molecular Mechanism of Serum Resistance of Neisseria gonorrhoeae

We screened 29 strains of Neisseria gonorrhoeae and found 16/21 strains that resisted killing by normal human serum and 0/8 serum sensitive strains that bound the complement regulator, C4b-binding protein (C4bp). Microbial surface–bound C4bp demonstrated cofactor activity. We constructed gonococcal strains with hybrid porin (Por) molecules derived from each of the major serogroups (Por1A and Por1B) of N. gonorrhoeae, and showed that the loop 1 of Por1A is required for C4bp binding. Por1B loops 5 and 7 of serum-resistant gonococci together formed a negatively charged C4bp-binding domain. C4bp–Por1B interactions were ionic in nature (inhibited by high salt or by heparin), whereas the C4bp–Por1A bond was hydrophobic. Only recombinant C4bp mutant molecules containing the NH2-terminal α-chain short consensus repeat (SCR1) bound to both Por1A and Por1B gonococci, suggesting that SCR1 contained Por binding sites. C4bp α-chain monomers did not bind gonococci, indicating that the polymeric form of C4bp was required for binding. Using fAb fragments against C4bp SCR1, C4bp binding to Por1A and Por1B strains was inhibited in a complement-dependent serum bactericidal assay. This resulted in complete killing of these otherwise fully serum resistant strains in only 10% normal serum, underscoring the importance of C4bp in mediating gonococcal serum resistance

A Computational and Experimental Study of the Regulatory Mechanisms of the Complement System

The complement system is key to innate immunity and its activation is necessary for the clearance of bacteria and apoptotic cells. However, insufficient or excessive complement activation will lead to immune-related diseases. It is so far unknown how the complement activity is up- or down- regulated and what the associated pathophysiological mechanisms are. To quantitatively understand the modulatory mechanisms of the complement system, we built a computational model involving the enhancement and suppression mechanisms that regulate complement activity. Our model consists of a large system of Ordinary Differential Equations (ODEs) accompanied by a dynamic Bayesian network as a probabilistic approximation of the ODE dynamics. Applying Bayesian inference techniques, this approximation was used to perform parameter estimation and sensitivity analysis. Our combined computational and experimental study showed that the antimicrobial response is sensitive to changes in pH and calcium levels, which determines the strength of the crosstalk between CRP and L-ficolin. Our study also revealed differential regulatory effects of C4BP. While C4BP delays but does not decrease the classical complement activation, it attenuates but does not significantly delay the lectin pathway activation. We also found that the major inhibitory role of C4BP is to facilitate the decay of C3 convertase. In summary, the present work elucidates the regulatory mechanisms of the complement system and demonstrates how the bio-pathway machinery maintains the balance between activation and inhibition. The insights we have gained could contribute to the development of therapies targeting the complement system.Singapore. Ministry of Education (Grant T208B3109)Singapore. Agency for Science, Technology and Research (BMRC 08/1/21/19/574)Singapore-MIT Alliance (Computational and Systems Biology Flagship Project)Swedish Research Counci

Knockdown of MTDH Sensitizes Endometrial Cancer Cells to Cell Death Induction by Death Receptor Ligand TRAIL and HDAC Inhibitor LBH589 Co-Treatment

Understanding the molecular underpinnings of chemoresistance is vital to design therapies to restore chemosensitivity. In particular, metadherin (MTDH) has been demonstrated to have a critical role in chemoresistance. Over-expression of MTDH correlates with poor clinical outcome in breast cancer, neuroblastoma, hepatocellular carcinoma and prostate cancer. MTDH is also highly expressed in advanced endometrial cancers, a disease for which new therapies are urgently needed. In this present study, we focused on the therapeutic benefit of MTDH depletion in endometrial cancer cells to restore sensitivity to cell death. Cells were treated with a combination of tumor necrosis factor-α-related apoptosis-inducing ligand (TRAIL), which promotes death of malignant cells of the human reproductive tract, and histone deacetylase (HDAC) inhibitors, which have been shown to increase the sensitivity of cancer cells to TRAIL-induced apoptosis. Our data indicate that depletion of MTDH in endometrial cancer cells resulted in sensitization of cells that were previously resistant in response to combinatorial treatment with TRAIL and the HDAC inhibitor LBH589. MTDH knockdown reduced the proportion of cells in S and increased cell arrest in G2/M in cells treated with LBH589 alone or LBH589 in combination with TRAIL, suggesting that MTDH functions at the cell cycle checkpoint to accomplish resistance. Using microarray technology, we identified 57 downstream target genes of MTDH, including calbindin 1 and galectin-1, which may contribute to MTDH-mediated therapeutic resistance. On the other hand, in MTDH depleted cells, inhibition of PDK1 and AKT phosphorylation along with increased Bim expression and XIAP degradation correlated with enhanced sensitivity to cell death in response to TRAIL and LBH589. These findings indicate that targeting or depleting MTDH is a potentially novel avenue for reversing therapeutic resistance in patients with endometrial cancer

Human Complement Regulators C4b-Binding Protein and C1 Esterase Inhibitor Interact with a Novel Outer Surface Protein of Borrelia recurrentis

The spirochete Borrelia recurrentis is the causal agent of louse-borne relapsing fever and is transmitted to humans by the infected body louse Pediculus humanus. We have recently demonstrated that the B. recurrentis surface receptor, HcpA, specifically binds factor H, the regulator of the alternative pathway of complement activation, thereby inhibiting complement mediated bacteriolysis. Here, we show that B. recurrentis spirochetes express another potential outer membrane lipoprotein, termed CihC, and acquire C4b-binding protein (C4bp) and human C1 esterase inhibitor (C1-Inh), the major inhibitors of the classical and lectin pathway of complement activation. A highly homologous receptor for C4bp was also found in the African tick-borne relapsing fever spirochete B. duttonii. Upon its binding to B. recurrentis or recombinant CihC, C4bp retains its functional potential, i.e. facilitating the factor I-mediated degradation of C4b. The additional finding that ectopic expression of CihC in serum sensitive B. burgdorferi significantly increased spirochetal resistance against human complement suggests this receptor to substantially contribute, together with other known strategies, to immune evasion of B. recurrentis