Deregulated expression of TANK in glioblastomas triggers pro-tumorigenic ERK1/2 and AKT signaling pathways.

PubMed

Stellzig, J; Chariot, A; Shostak, K; Ismail Göktuna, S; Renner, F; Acker, T; Pagenstecher, A; Schmitz, M L

2013-11-11

Signal transmission by the noncanonical IkappaB kinases (IKKs), TANK-binding kinase 1 (TBK1) and IKKɛ, requires interaction with adapter proteins such as TRAF associated NF-κB activator (TANK). Although increased expression or dysregulation of both kinases has been described for a variety of human cancers, this study shows that deregulated expression of the TANK protein is frequently occurring in glioblastomas (GBMs). The functional relevance of TANK was analyzed in a panel of GBM-derived cell lines and revealed that knockdown of TANK arrests cells in the S-phase and prohibits tumor cell migration. Deregulated TANK expression affects several signaling pathways controlling cell proliferation and the inflammatory response. Interference with stoichiometrically assembled signaling complexes by overexpression or silencing of TANK prevented constitutive interferon-regulatory factor 3 (IRF3) phosphorylation. Knockdown of TANK frequently prevents constitutive activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2). TANK-mediated ERK1/2 activation is independent from the canonical MAP kinase or ERK kinase (MEK) 1/2-mediated pathway and utilizes an alternative pathway that uses a TBK1/IKKɛ/Akt signaling axis, thus identifying a novel pathway suitable to block constitutive ERK1/2 activity.

Deregulated expression of TANK in glioblastomas triggers pro-tumorigenic ERK1/2 and AKT signaling pathways

PubMed Central

Stellzig, J; Chariot, A; Shostak, K; Ismail Göktuna, S; Renner, F; Acker, T; Pagenstecher, A; Schmitz, M L

2013-01-01

Signal transmission by the noncanonical IkappaB kinases (IKKs), TANK-binding kinase 1 (TBK1) and IKKɛ, requires interaction with adapter proteins such as TRAF associated NF-κB activator (TANK). Although increased expression or dysregulation of both kinases has been described for a variety of human cancers, this study shows that deregulated expression of the TANK protein is frequently occurring in glioblastomas (GBMs). The functional relevance of TANK was analyzed in a panel of GBM-derived cell lines and revealed that knockdown of TANK arrests cells in the S-phase and prohibits tumor cell migration. Deregulated TANK expression affects several signaling pathways controlling cell proliferation and the inflammatory response. Interference with stoichiometrically assembled signaling complexes by overexpression or silencing of TANK prevented constitutive interferon-regulatory factor 3 (IRF3) phosphorylation. Knockdown of TANK frequently prevents constitutive activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2). TANK-mediated ERK1/2 activation is independent from the canonical MAP kinase or ERK kinase (MEK) 1/2-mediated pathway and utilizes an alternative pathway that uses a TBK1/IKKɛ/Akt signaling axis, thus identifying a novel pathway suitable to block constitutive ERK1/2 activity. PMID:24217713

‘N-of-1-pathways’ unveils personal deregulated mechanisms from a single pair of RNA-Seq samples: towards precision medicine

PubMed Central

Gardeux, Vincent; Achour, Ikbel; Li, Jianrong; Maienschein-Cline, Mark; Li, Haiquan; Pesce, Lorenzo; Parinandi, Gurunadh; Bahroos, Neil; Winn, Robert; Foster, Ian; Garcia, Joe G N; Lussier, Yves A

2014-01-01

Background The emergence of precision medicine allowed the incorporation of individual molecular data into patient care. Indeed, DNA sequencing predicts somatic mutations in individual patients. However, these genetic features overlook dynamic epigenetic and phenotypic response to therapy. Meanwhile, accurate personal transcriptome interpretation remains an unmet challenge. Further, N-of-1 (single-subject) efficacy trials are increasingly pursued, but are underpowered for molecular marker discovery. Method ‘N-of-1-pathways’ is a global framework relying on three principles: (i) the statistical universe is a single patient; (ii) significance is derived from geneset/biomodules powered by paired samples from the same patient; and (iii) similarity between genesets/biomodules assesses commonality and differences, within-study and cross-studies. Thus, patient gene-level profiles are transformed into deregulated pathways. From RNA-Seq of 55 lung adenocarcinoma patients, N-of-1-pathways predicts the deregulated pathways of each patient. Results Cross-patient N-of-1-pathways obtains comparable results with conventional genesets enrichment analysis (GSEA) and differentially expressed gene (DEG) enrichment, validated in three external evaluations. Moreover, heatmap and star plots highlight both individual and shared mechanisms ranging from molecular to organ-systems levels (eg, DNA repair, signaling, immune response). Patients were ranked based on the similarity of their deregulated mechanisms to those of an independent gold standard, generating unsupervised clusters of diametric extreme survival phenotypes (p=0.03). Conclusions The N-of-1-pathways framework provides a robust statistical and relevant biological interpretation of individual disease-free survival that is often overlooked in conventional cross-patient studies. It enables mechanism-level classifiers with smaller cohorts as well as N-of-1 studies. Software http://lussierlab.org/publications/N-of-1-pathways PMID:25301808

‘N-of-1- pathways ’ unveils personal deregulated mechanisms from a single pair of RNA-Seq samples: Towards precision medicine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gardeux, Vincent; Achour, Ikbel; Li, Jianrong

Background: The emergence of precision medicine allowed the incorporation of individual molecular data into patient care. This research entails, DNA sequencing predicts somatic mutations in individual patients. However, these genetic features overlook dynamic epigenetic and phenotypic response to therapy. Meanwhile, accurate personal transcriptome interpretation remains an unmet challenge. Further, N-of-1 (single-subject) efficacy trials are increasingly pursued, but are underpowered for molecular marker discovery. Method: ‘N-of-1- pathways’ is a global framework relying on three principles: (i) the statistical universe is a single patient; (ii) significance is derived from geneset/biomodules powered by paired samples from the same patient; and (iii) similarity betweenmore » genesets/biomodules assesses commonality and differences, within-study and cross-studies. Thus, patient gene-level profiles are transformed into deregulated pathways. From RNA-Seq of 55 lung adenocarcinoma patients, N-of-1- pathways predicts the deregulated pathways of each patient. Results: Cross-patient N-of-1- pathways obtains comparable results with conventional genesets enrichment analysis (GSEA) and differentially expressed gene (DEG) enrichment, validated in three external evaluations. Moreover, heatmap and star plots highlight both individual and shared mechanisms ranging from molecular to organ-systems levels (eg, DNA repair, signaling, immune response). Patients were ranked based on the similarity of their deregulated mechanisms to those of an independent gold standard, generating unsupervised clusters of diametric extreme survival phenotypes (p=0.03). Conclusions: The N-of-1- pathways framework provides a robust statistical and relevant biological interpretation of individual disease-free survival that is often overlooked in conventional cross-patient studies. It enables mechanism-level classifiers with smaller cohorts as well as N-of-1 studies.« less

‘N-of-1- pathways ’ unveils personal deregulated mechanisms from a single pair of RNA-Seq samples: Towards precision medicine

DOE PAGES

Gardeux, Vincent; Achour, Ikbel; Li, Jianrong; ...

2014-11-01

Background: The emergence of precision medicine allowed the incorporation of individual molecular data into patient care. This research entails, DNA sequencing predicts somatic mutations in individual patients. However, these genetic features overlook dynamic epigenetic and phenotypic response to therapy. Meanwhile, accurate personal transcriptome interpretation remains an unmet challenge. Further, N-of-1 (single-subject) efficacy trials are increasingly pursued, but are underpowered for molecular marker discovery. Method: ‘N-of-1- pathways’ is a global framework relying on three principles: (i) the statistical universe is a single patient; (ii) significance is derived from geneset/biomodules powered by paired samples from the same patient; and (iii) similarity betweenmore » genesets/biomodules assesses commonality and differences, within-study and cross-studies. Thus, patient gene-level profiles are transformed into deregulated pathways. From RNA-Seq of 55 lung adenocarcinoma patients, N-of-1- pathways predicts the deregulated pathways of each patient. Results: Cross-patient N-of-1- pathways obtains comparable results with conventional genesets enrichment analysis (GSEA) and differentially expressed gene (DEG) enrichment, validated in three external evaluations. Moreover, heatmap and star plots highlight both individual and shared mechanisms ranging from molecular to organ-systems levels (eg, DNA repair, signaling, immune response). Patients were ranked based on the similarity of their deregulated mechanisms to those of an independent gold standard, generating unsupervised clusters of diametric extreme survival phenotypes (p=0.03). Conclusions: The N-of-1- pathways framework provides a robust statistical and relevant biological interpretation of individual disease-free survival that is often overlooked in conventional cross-patient studies. It enables mechanism-level classifiers with smaller cohorts as well as N-of-1 studies.« less

Mechanisms of Resistance to Chemotherapies Targeting BRCA-Mutant Breast Cancer

DTIC Science & Technology

2015-12-01

limiting for mutagenic NHEJ but not for physiological CSR. An implication of our results is that deregulation of the RNF168/53BP1 pathway could alter the...resistance in BRCA-deficient tumors. We have also observed that deregulation of the RNF168/53BP1 pathway can alter the chemosensitivity of BRCA1 deficient...FASEB Summer Research Conference. Big Sky, Montana, 2015 g. Invited Speaker, Conference "Chromatin and Cell Fate", Essen, Germany , 2015 h. Invited

Deregulation upon DNA damage revealed by joint analysis of context-specific perturbation data

PubMed Central

2011-01-01

Background Deregulation between two different cell populations manifests itself in changing gene expression patterns and changing regulatory interactions. Accumulating knowledge about biological networks creates an opportunity to study these changes in their cellular context. Results We analyze re-wiring of regulatory networks based on cell population-specific perturbation data and knowledge about signaling pathways and their target genes. We quantify deregulation by merging regulatory signal from the two cell populations into one score. This joint approach, called JODA, proves advantageous over separate analysis of the cell populations and analysis without incorporation of knowledge. JODA is implemented and freely available in a Bioconductor package 'joda'. Conclusions Using JODA, we show wide-spread re-wiring of gene regulatory networks upon neocarzinostatin-induced DNA damage in Human cells. We recover 645 deregulated genes in thirteen functional clusters performing the rich program of response to damage. We find that the clusters contain many previously characterized neocarzinostatin target genes. We investigate connectivity between those genes, explaining their cooperation in performing the common functions. We review genes with the most extreme deregulation scores, reporting their involvement in response to DNA damage. Finally, we investigate the indirect impact of the ATM pathway on the deregulated genes, and build a hypothetical hierarchy of direct regulation. These results prove that JODA is a step forward to a systems level, mechanistic understanding of changes in gene regulation between different cell populations. PMID:21693013

Deregulation upon DNA damage revealed by joint analysis of context-specific perturbation data.

PubMed

Szczurek, Ewa; Markowetz, Florian; Gat-Viks, Irit; Biecek, Przemysław; Tiuryn, Jerzy; Vingron, Martin

2011-06-21

Deregulation between two different cell populations manifests itself in changing gene expression patterns and changing regulatory interactions. Accumulating knowledge about biological networks creates an opportunity to study these changes in their cellular context. We analyze re-wiring of regulatory networks based on cell population-specific perturbation data and knowledge about signaling pathways and their target genes. We quantify deregulation by merging regulatory signal from the two cell populations into one score. This joint approach, called JODA, proves advantageous over separate analysis of the cell populations and analysis without incorporation of knowledge. JODA is implemented and freely available in a Bioconductor package 'joda'. Using JODA, we show wide-spread re-wiring of gene regulatory networks upon neocarzinostatin-induced DNA damage in Human cells. We recover 645 deregulated genes in thirteen functional clusters performing the rich program of response to damage. We find that the clusters contain many previously characterized neocarzinostatin target genes. We investigate connectivity between those genes, explaining their cooperation in performing the common functions. We review genes with the most extreme deregulation scores, reporting their involvement in response to DNA damage. Finally, we investigate the indirect impact of the ATM pathway on the deregulated genes, and build a hypothetical hierarchy of direct regulation. These results prove that JODA is a step forward to a systems level, mechanistic understanding of changes in gene regulation between different cell populations.

Cross-study and cross-omics comparisons of three nephrotoxic compounds reveal mechanistic insights and new candidate biomarkers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matheis, Katja A., E-mail: katja.matheis@boehringer-ingelheim.com; Com, Emmanuelle; High-Throughput Proteomics Core Facility OUEST-genopole

2011-04-15

The European InnoMed-PredTox project was a collaborative effort between 15 pharmaceutical companies, 2 small and mid-sized enterprises, and 3 universities with the goal of delivering deeper insights into the molecular mechanisms of kidney and liver toxicity and to identify mechanism-linked diagnostic or prognostic safety biomarker candidates by combining conventional toxicological parameters with 'omics' data. Mechanistic toxicity studies with 16 different compounds, 2 dose levels, and 3 time points were performed in male Crl: WI(Han) rats. Three of the 16 investigated compounds, BI-3 (FP007SE), Gentamicin (FP009SF), and IMM125 (FP013NO), induced kidney proximal tubule damage (PTD). In addition to histopathology and clinicalmore » chemistry, transcriptomics microarray and proteomics 2D-DIGE analysis were performed. Data from the three PTD studies were combined for a cross-study and cross-omics meta-analysis of the target organ. The mechanistic interpretation of kidney PTD-associated deregulated transcripts revealed, in addition to previously described kidney damage transcript biomarkers such as KIM-1, CLU and TIMP-1, a number of additional deregulated pathways congruent with histopathology observations on a single animal basis, including a specific effect on the complement system. The identification of new, more specific biomarker candidates for PTD was most successful when transcriptomics data were used. Combining transcriptomics data with proteomics data added extra value.« less

Neuronal Dysfunction Associated with Cholesterol Deregulation

PubMed Central

Loganes, Claudia; Bilel, Sabrine; Celeghini, Claudio; Tommasini, Alberto

2018-01-01

Cholesterol metabolism is crucial for cells and, in particular, its biosynthesis in the central nervous system occurs in situ, and its deregulation involves morphological changes that cause functional variations and trigger programmed cell death. The pathogenesis of rare diseases, such as Mevalonate Kinase Deficiency or Smith–Lemli–Opitz Syndrome, arises due to enzymatic defects in the cholesterol metabolic pathways, resulting in a shortage of downstream products. The most severe clinical manifestations of these diseases appear as neurological defects. Expanding the knowledge of this biological mechanism will be useful for identifying potential targets and preventing neuronal damage. Several studies have demonstrated that deregulation of the cholesterol pathway induces mitochondrial dysfunction as the result of respiratory chain damage. We set out to determine whether mitochondrial damage may be prevented by using protective mitochondria-targeted compounds, such as MitoQ, in a neuronal cell line treated with a statin to induce a biochemical block of the cholesterol pathway. Evidence from the literature suggests that mitochondria play a crucial role in the apoptotic mechanism secondary to blocking the cholesterol pathway. Our study shows that MitoQ, administered as a preventive agent, could counteract the cell damage induced by statins in the early stages, but its protective role fades over time. PMID:29783748

[Design of new anti-tumor agents interrupting deregulated signaling pathways induced by tyrosine kinase proteins. Inhibition of protein-protein interaction involving Grb2].

PubMed

Vidal, Michel; Liu, Wang Qing; Gril, Brunile; Assayag, Franck; Poupon, Marie-France; Garbay, Christiane

2004-01-01

Cellular signaling pathways induced by growth-factor receptors are frequently deregulated in cancer. Anti-tumor agents that inhibit their enzymatic tyrosine kinase activity have been designed and are now used in human chemotherapy. We propose here an alternative way to interrupt over-expressed signaling by inhibiting protein-protein interactions that involve either the over-expressed proteins or proteins located downstream. The adaptor protein Grb2 over-expressed in connection with HER2/ErbB2/neu in Ras signaling pathway was chosen as a target. Peptides with very high affinity for Grb2 were rationally designed from structural data. Their capacity to interrupt the signaling pathway, their anti-proliferative activity as well as their potential anti-tumor properties are described.

The Akt signaling pathway

PubMed Central

Madhunapantula, SubbaRao V; Mosca, Paul J

2011-01-01

Studies using cultured melanoma cells and patient tumor biopsies have demonstrated deregulated PI3 kinase-Akt3 pathway activity in ∼70% of melanomas. Furthermore, targeting Akt3 and downstream PRAS40 has been shown to inhibit melanoma tumor development in mice. Although these preclinical studies and several other reports using small interfering RNAs and pharmacological agents targeting key members of this pathway have been shown to retard melanoma development, analysis of early Phase I and Phase II clinical trials using pharmacological agents to target this pathway demonstrate the need for (1) selection of patients whose tumors have PI3 kinase-Akt pathway deregulation, (2) further optimization of therapeutic agents for increased potency and reduced toxicity, (3) the identification of additional targets in the same pathway or in other signaling cascades that synergistically inhibit the growth and progression of melanoma, and (4) better methods for targeted delivery of pharmaceutical agents inhibiting this pathway. In this review we discuss key potential targets in PI3K-Akt3 signaling, the status of pharmacological agents targeting these proteins, drugs under clinical development, and strategies to improve the efficacy of therapeutic agents targeting this pathway. PMID:22157148

In vitro C3 Deposition on Cryptococcus Capsule Occurs Via Multiple Complement Activation Pathways

PubMed Central

Mershon-Shier, Kileen L.; Vasuthasawat, Alex; Takahashi, Kazue; Morrison, Sherie L.; Beenhouwer, David O.

2011-01-01

Complement can be activated via three pathways: classical, alternative, and lectin. Cryptococcus gattii and C. neoformans are closely related fungal pathogens possessing a polysaccharide capsule composed mainly of glucuronoxylomannan (GXM), which serves as a site for complement activation and deposition of complement components. We determined C3 deposition on Cryptococcus spp. by flow cytometry and confocal microscopy after incubation with serum from C57BL/6J mice as well as mice deficient in complement components C4, C3, factor B, and mannose binding lectin (MBL). C. gattii and C. neoformans activate complement in EGTA-treated serum indicating that they can activate the alternative pathway. However, complement activation was seen with factor B−/− serum suggesting activation could also take place in the absence of a functional alternative pathway. Furthermore, we uncovered a role for C4 in the alternative pathway activation by Cryptococcus spp. We also identified an unexpected and complex role for MBL in complement activation by Cryptococcus spp. No complement activation occurred in the absence of MBL-A and -C proteins although activation took place when the lectin binding activity of MBL was disrupted by calcium chelation. In addition, alternative pathway activation by C. neoformans required both MBL-A and -C, while either MBL-A or -C was sufficient for alternative pathway activation by C. gattii. Thus, complement activation by Cryptococcus spp. can take place through multiple pathways and complement activation via the alternative pathway requires the presence of C4 and MBL proteins. PMID:21723612

Pathway-based personalized analysis of cancer

PubMed Central

Drier, Yotam; Sheffer, Michal; Domany, Eytan

2013-01-01

We introduce Pathifier, an algorithm that infers pathway deregulation scores for each tumor sample on the basis of expression data. This score is determined, in a context-specific manner, for every particular dataset and type of cancer that is being investigated. The algorithm transforms gene-level information into pathway-level information, generating a compact and biologically relevant representation of each sample. We demonstrate the algorithm’s performance on three colorectal cancer datasets and two glioblastoma multiforme datasets and show that our multipathway-based representation is reproducible, preserves much of the original information, and allows inference of complex biologically significant information. We discovered several pathways that were significantly associated with survival of glioblastoma patients and two whose scores are predictive of survival in colorectal cancer: CXCR3-mediated signaling and oxidative phosphorylation. We also identified a subclass of proneural and neural glioblastoma with significantly better survival, and an EGF receptor-deregulated subclass of colon cancers. PMID:23547110

SALO, a novel classical pathway complement inhibitor from saliva of the sand fly Lutzomyia longipalpis

PubMed Central

Ferreira, Viviana P.; Fazito Vale, Vladimir; Pangburn, Michael K.; Abdeladhim, Maha; Ferreira Mendes-Sousa, Antonio; Coutinho-Abreu, Iliano V.; Rasouli, Manoochehr; Brandt, Elizabeth A.; Meneses, Claudio; Lima, Kolyvan Ferreira; Nascimento Araújo, Ricardo; Horácio Pereira, Marcos; Kotsyfakis, Michalis; Oliveira, Fabiano; Kamhawi, Shaden; Ribeiro, Jose M. C.; Gontijo, Nelder F.; Collin, Nicolas; Valenzuela, Jesus G.

2016-01-01

Blood-feeding insects inject potent salivary components including complement inhibitors into their host’s skin to acquire a blood meal. Sand fly saliva was shown to inhibit the classical pathway of complement; however, the molecular identity of the inhibitor remains unknown. Here, we identified SALO as the classical pathway complement inhibitor. SALO, an 11 kDa protein, has no homology to proteins of any other organism apart from New World sand flies. rSALO anti-complement activity has the same chromatographic properties as the Lu. longipalpis salivary gland homogenate (SGH)counterparts and anti-rSALO antibodies blocked the classical pathway complement activity of rSALO and SGH. Both rSALO and SGH inhibited C4b deposition and cleavage of C4. rSALO, however, did not inhibit the protease activity of C1s nor the enzymatic activity of factor Xa, uPA, thrombin, kallikrein, trypsin and plasmin. Importantly, rSALO did not inhibit the alternative or the lectin pathway of complement. In conclusion our data shows that SALO is a specific classical pathway complement inhibitor present in the saliva of Lu. longipalpis. Importantly, due to its small size and specificity, SALO may offer a therapeutic alternative for complement classical pathway-mediated pathogenic effects in human diseases. PMID:26758086

Complement Factor B Mutations in Atypical Hemolytic Uremic Syndrome—Disease-Relevant or Benign?

PubMed Central

Marinozzi, Maria Chiara; Vergoz, Laura; Rybkine, Tania; Ngo, Stephanie; Bettoni, Serena; Pashov, Anastas; Cayla, Mathieu; Tabarin, Fanny; Jablonski, Mathieu; Hue, Christophe; Smith, Richard J.; Noris, Marina; Halbwachs-Mecarelli, Lise; Donadelli, Roberta; Fremeaux-Bacchi, Veronique

2014-01-01

Atypical hemolytic uremic syndrome (aHUS) is a genetic ultrarare renal disease associated with overactivation of the alternative pathway of complement. Four gain-of-function mutations that form a hyperactive or deregulated C3 convertase have been identified in Factor B (FB) ligand binding sites. Here, we studied the functional consequences of 10 FB genetic changes recently identified from different aHUS cohorts. Using several tests for alternative C3 and C5 convertase formation and regulation, we identified two gain-of-function and potentially disease-relevant mutations that formed either an overactive convertase (M433I) or a convertase resistant to decay by FH (K298Q). One mutation (R178Q) produced a partially cleaved protein with no ligand binding or functional activity. Seven genetic changes led to near-normal or only slightly reduced ligand binding and functional activity compared with the most common polymorphism at position 7, R7. Notably, none of the algorithms used to predict the disease relevance of FB mutations agreed completely with the experimental data, suggesting that in silico approaches should be undertaken with caution. These data, combined with previously published results, suggest that 9 of 15 FB genetic changes identified in patients with aHUS are unrelated to disease pathogenesis. This study highlights that functional assessment of identified nucleotide changes in FB is mandatory to confirm disease association. PMID:24652797

Sparking Fire Under the Skin? Answers From the Association of Complement Genes With Pemphigus Foliaceus

PubMed Central

Bumiller-Bini, Valéria; Cipolla, Gabriel Adelman; de Almeida, Rodrigo Coutinho; Petzl-Erler, Maria Luiza; Augusto, Danillo Gardenal; Boldt, Angelica Beate Winter

2018-01-01

Skin blisters of pemphigus foliaceus (PF) present concomitant deposition of autoantibodies and components of the complement system (CS), whose gene polymorphisms are associated with susceptibility to different autoimmune diseases. To investigate these in PF, we evaluated 992 single-nucleotide polymorphisms (SNPs) of 44 CS genes, genotyped through microarray hybridization in 229 PF patients and 194 controls. After excluding SNPs with minor allele frequency <1%, out of Hardy–Weinberg equilibrium in controls or in strong linkage disequilibrium (r2 ≥ 0.8), 201 SNPs remained for logistic regression. Polymorphisms of 11 genes were associated with PF. MASP1 encodes a crucial serine protease of the lectin pathway (rs13094773: OR = 0.5, p = 0.0316; rs850309: OR = 0.23, p = 0.03; rs3864098: OR = 1.53, p = 0.0383; rs698104: OR = 1.52, p = 0.0424; rs72549154: OR = 0.55, p = 0.0453). C9 (rs187875: OR = 1.46, p = 0.0189; rs700218: OR = 0.12, p = 0.0471) and C8A (rs11206934: OR = 4.02, p = 0.0323) encode proteins of the membrane attack complex (MAC) and C5AR1 (rs10404456: OR = 1.43, p = 0.0155), a potent anaphylatoxin-receptor. Two encode complement regulators: MAC-blocking CD59 (rs1047581: OR = 0.62, p = 0.0152) and alternative pathway-blocking CFH (rs34388368: OR = 2.57, p = 0.0195). One encodes opsonin: C3 (rs4807895: OR = 2.52, p = 0.0239), whereas four encode receptors for C3 fragments: CR1 (haplotype with rs6656401: OR = 1.37, p = 0.0382), CR2 (rs2182911: OR = 0.23, p = 0.0263), ITGAM (CR3, rs12928810: OR = 0.66, p = 0.0435), and ITGAX (CR4, rs11574637: OR = 0.63, p = 0.0056). Associations reinforced former findings, regarding differential gene expression, serum levels, C3, and MAC deposition on lesions. Deregulation of previously barely noticed processes, e.g., the lectin and alternative pathways and opsonization-mediated phagocytosis, also modulate PF susceptibility. The results open new crucial avenues for understanding disease etiology and may improve PF treatment through additional therapeutic targets. PMID:29686679

FAS system deregulation in T-cell lymphoblastic lymphoma

PubMed Central

Villa-Morales, M; Cobos, M A; González-Gugel, E; Álvarez-Iglesias, V; Martínez, B; Piris, M A; Carracedo, A; Benítez, J; Fernández-Piqueras, J

2014-01-01

The acquisition of resistance towards FAS-mediated apoptosis may be required for tumor formation. Tumors from various histological origins exhibit FAS mutations, the most frequent being hematological malignancies. However, data regarding FAS mutations or FAS signaling alterations are still lacking in precursor T-cell lymphoblastic lymphomas (T-LBLs). The available data on acute lymphoblastic leukemia, of precursor origin as well, indicate a low frequency of FAS mutations but often report a serious reduction in FAS-mediated apoptosis as well as chemoresistance, thus suggesting the occurrence of mechanisms able to deregulate the FAS signaling pathway, different from FAS mutation. Our aim at this study was to determine whether FAS-mediated apoptotic signaling is compromised in human T-LBL samples and the mechanisms involved. This study on 26 T-LBL samples confirms that the FAS system is impaired to a wide extent in these tumors, with 57.7% of the cases presenting any alteration of the pathway. A variety of mechanisms seems to be involved in such alteration, in order of frequency the downregulation of FAS, the deregulation of other members of the pathway and the occurrence of mutations at FAS. Considering these results together, it seems plausible to think of a cumulative effect of several alterations in each T-LBL, which in turn may result in FAS/FASLG system deregulation. Since defective FAS signaling may render the T-LBL tumor cells resistant to apoptotic cell death, the correct prognosis, diagnosis and thus the success of anticancer therapy may require such an in-depth knowledge of the complete scenario of FAS-signaling alterations. PMID:24603338

Approaches for targeting self-renewal pathways in cancer stem cells: implications for hematological treatments.

PubMed

Horne, Gillian A; Copland, Mhairi

2017-05-01

Self-renewal is considered a defining property of stem cells. Self-renewal is essential in embryogenesis and normal tissue repair and homeostasis. However, in cancer, self-renewal pathways, e.g. WNT, NOTCH, Hedgehog and BMP, frequently become de-regulated in stem cells, or more mature progenitor cells acquire self-renewal properties, resulting in abnormal tissue growth and tumorigenesis. Areas covered: This review considers the conserved embryonic self-renewal pathways, including WNT, NOTCH, Hedgehog and BMP. The article describes recent advances in our understanding of these pathways in leukemia and, more specifically, leukemia stem cells (LSC), how these pathways cross-talk and interact with the LSC microenvironment, and discusses the clinical implications and potential therapeutic strategies, both in preclinical and in clinical trials for hematological malignancies. Expert opinion: The conserved embryonic self-renewal pathways are frequently de-regulated in cancer stem cells (CSC), including LSCs. There is significant cross-talk between self-renewal pathways, and their downstream targets, and the microenvironment. Effective targeting of these pathways is challenging due to cross-talk, and importantly, because these pathways are important for normal stem cells as well as CSC, adverse effects on normal tissues may mean a therapeutic window cannot be identified. Nonetheless, several agents targeting these pathways are currently in clinical trials in hematological malignancies.

The role of complement system in septic shock.

PubMed

Charchaflieh, Jean; Wei, Jiandong; Labaze, Georges; Hou, Yunfang Joan; Babarsh, Benjamin; Stutz, Helen; Lee, Haekyung; Worah, Samrat; Zhang, Ming

2012-01-01

Septic shock is a critical clinical condition with a high mortality rate. A better understanding of the underlying mechanisms is important to develop effective therapies. Basic and clinical studies suggest that activation of complements in the common cascade, for example, complement component 3 (C3) and C5, is involved in the development of septic shock. The involvement of three upstream complement pathways in septic shock is more complicated. Both the classical and alternative pathways appear to be activated in septic shock, but the alternative pathway may be activated earlier than the classical pathway. Activation of these two pathways is essential to clear endotoxin. Recent investigations have shed light on the role of lectin complement pathway in septic shock. Published reports suggest a protective role of mannose-binding lectin (MBL) against sepsis. Our preliminary study of MBL-associated serine protease-2 (MASP-2) in septic shock patients indicated that acute decrease of MASP-2 in the early phase of septic shock might correlate with in-hospital mortality. It is unknown whether excessive activation of these three upstream complement pathways may contribute to the detrimental effects in septic shock. This paper also discusses additional complement-related pathogenic mechanisms and intervention strategies for septic shock.

The therapeutic potential of cell cycle targeting in multiple myeloma.

PubMed

Maes, Anke; Menu, Eline; Veirman, Kim De; Maes, Ken; Vand Erkerken, Karin; De Bruyne, Elke

2017-10-27

Proper cell cycle progression through the interphase and mitosis is regulated by coordinated activation of important cell cycle proteins (including cyclin-dependent kinases and mitotic kinases) and several checkpoint pathways. Aberrant activity of these cell cycle proteins and checkpoint pathways results in deregulation of cell cycle progression, which is one of the key hallmarks of cancer. Consequently, intensive research on targeting these cell cycle regulatory proteins identified several candidate small molecule inhibitors that are able to induce cell cycle arrest and even apoptosis in cancer cells. Importantly, several of these cell cycle regulatory proteins have also been proposed as therapeutic targets in the plasma cell malignancy multiple myeloma (MM). Despite the enormous progress in the treatment of MM the past 5 years, MM still remains most often incurable due to the development of drug resistance. Deregulated expression of the cyclins D is observed in virtually all myeloma patients, emphasizing the potential therapeutic interest of cyclin-dependent kinase inhibitors in MM. Furthermore, other targets have also been identified in MM, such as microtubules, kinesin motor proteins, aurora kinases, polo-like kinases and the anaphase promoting complex/cyclosome. This review will provide an overview of the cell cycle proteins and checkpoint pathways deregulated in MM and discuss the therapeutic potential of targeting proteins or protein complexes involved in cell cycle control in MM.

Genetic control of the alternative pathway of complement in humans and age-related macular degeneration

PubMed Central

Hecker, Laura A.; Edwards, Albert O.; Ryu, Euijung; Tosakulwong, Nirubol; Baratz, Keith H.; Brown, William L.; Issa, Peter Charbel; Scholl, Hendrik P.; Pollok-Kopp, Beatrix; Schmid-Kubista, Katharina E.; Bailey, Kent R.; Oppermann, Martin

2010-01-01

Activation of the alternative pathway of complement is implicated in common neurodegenerative diseases including age-related macular degeneration (AMD). We explored the impact of common variation in genes encoding proteins of the alternative pathway on complement activation in human blood and in AMD. Genetic variation across the genes encoding complement factor H (CFH), factor B (CFB) and component 3 (C3) was determined. The influence of common haplotypes defining transcriptional and translational units on complement activation in blood was determined in a quantitative genomic association study. Individual haplotypes in CFH and CFB were associated with distinct and novel effects on plasma levels of precursors, regulators and activation products of the alternative pathway of complement in human blood. Further, genetic variation in CFH thought to influence cell surface regulation of complement did not alter plasma complement levels in human blood. Plasma markers of chronic activation (split-products Ba and C3d) and an activating enzyme (factor D) were elevated in AMD subjects. Most of the elevation in AMD was accounted for by the genetic variation controlling complement activation in human blood. Activation of the alternative pathway of complement in blood is under genetic control and increases with age. The genetic variation associated with increased activation of complement in human blood also increased the risk of AMD. Our data are consistent with a disease model in which genetic variation in the complement system increases the risk of AMD by a combination of systemic complement activation and abnormal regulation of complement activation in local tissues. PMID:19825847

Complement in autoimmune diseases.

PubMed

Vignesh, Pandiarajan; Rawat, Amit; Sharma, Madhubala; Singh, Surjit

2017-02-01

The complement system is an ancient and evolutionary conserved element of the innate immune mechanism. It comprises of more than 20 serum proteins most of which are synthesized in the liver. These proteins are synthesized as inactive precursor proteins which are activated by appropriate stimuli. The activated forms of these proteins act as proteases and cleave other components successively in amplification pathways leading to exponential generation of final effectors. Three major pathways of complement pathways have been described, namely the classical, alternative and lectin pathways which are activated by different stimuli. However, all the 3 pathways converge on Complement C3. Cleavage of C3 and C5 successively leads to the production of the membrane attack complex which is final common effector. Excessive and uncontrolled activation of the complement has been implicated in the host of autoimmune diseases. But the complement has also been bemusedly described as the proverbial "double edged sword". On one hand, complement is the final effector of tissue injury in autoimmune diseases and on the other, deficiencies of some components of the complement can result in autoimmune diseases. Currently available tools such as enzyme based immunoassays for functional assessment of complement pathways, flow cytometry, next generation sequencing and proteomics-based approaches provide an exciting opportunity to study this ancient yet mysterious element of innate immunity. Copyright © 2017 Elsevier B.V. All rights reserved.

Molecular pathogenesis of splenic and nodal marginal zone lymphoma.

PubMed

Spina, Valeria; Rossi, Davide

Genomic studies have improved our understanding of the biological basis of splenic (SMZL) and nodal (NMZL) marginal zone lymphoma by providing a comprehensive and unbiased view of the genes/pathways that are deregulated in these diseases. Consistent with the physiological involvement of NOTCH, NF-κB, B-cell receptor and toll-like receptor signaling in mature B-cells differentiation into the marginal zone B-cells, many oncogenic mutations of genes involved in these pathways have been identified in SMZL and NMZL. Beside genetic lesions, also epigenetic and post-transcriptional modifications contribute to the deregulation of marginal zone B-cell differentiation pathways in SMZL and NMZL. This review describes the progress in understanding the molecular mechanism underlying SMZL and NMZL, including molecular and post-transcriptional modifications, and discusses how information gained from these efforts has provided new insights on potential targets of diagnostic, prognostic and therapeutic relevance in SMZL and NMZL. Copyright © 2016 Elsevier Ltd. All rights reserved.

Protective immune responses against West Nile virus are primed by distinct complement activation pathways.

PubMed

Mehlhop, Erin; Diamond, Michael S

2006-05-15

West Nile virus (WNV) causes a severe infection of the central nervous system in several vertebrate animals including humans. Prior studies have shown that complement plays a critical role in controlling WNV infection in complement (C) 3(-/-) and complement receptor 1/2(-/-) mice. Here, we dissect the contributions of the individual complement activation pathways to the protection from WNV disease. Genetic deficiencies in C1q, C4, factor B, or factor D all resulted in increased mortality in mice, suggesting that all activation pathways function together to limit WNV spread. In the absence of alternative pathway complement activation, WNV disseminated into the central nervous system at earlier times and was associated with reduced CD8+ T cell responses yet near normal anti-WNV antibody profiles. Animals lacking the classical and lectin pathways had deficits in both B and T cell responses to WNV. Finally, and somewhat surprisingly, C1q was required for productive infection in the spleen but not for development of adaptive immune responses after WNV infection. Our results suggest that individual pathways of complement activation control WNV infection by priming adaptive immune responses through distinct mechanisms.

Non-specific adsorption of complement proteins affects complement activation pathways of gold nanomaterials.

PubMed

Quach, Quang Huy; Kah, James Chen Yong

2017-04-01

The complement system is a key humoral component of innate immunity, serving as the first line of defense against intruders, including foreign synthetic nanomaterials. Although gold nanomaterials (AuNMs) are widely used in nanomedicine, their immunological response is not well understood. Using AuNMs of three shapes commonly used in biomedical applications: spherical gold nanoparticles, gold nanostars and gold nanorods, we demonstrated that AuNMs activated whole complement system, leading to the formation of SC5b-9 complex. All three complement pathways were simultaneously activated by all the AuNMs. Recognition molecules of the complement system interacted with all AuNMs in vitro, except for l-ficolin, but the correlation between these interactions and corresponding complement pathway activation was only observed in the classical and alternative pathways. We also observed the mediating role of complement activation in cellular uptake of all AuNMs by human U937 promonocytic cells, which expresses complement receptors. Taken together, our results highlighted the potential immunological challenges for clinical applications of AuNMs that were often overlooked.

A Rich-Club Organization in Brain Ischemia Protein Interaction Network

PubMed Central

Alawieh, Ali; Sabra, Zahraa; Sabra, Mohammed; Tomlinson, Stephen; Zaraket, Fadi A.

2015-01-01

Ischemic stroke involves multiple pathophysiological mechanisms with complex interactions. Efforts to decipher those mechanisms and understand the evolution of cerebral injury is key for developing successful interventions. In an innovative approach, we use literature mining, natural language processing and systems biology tools to construct, annotate and curate a brain ischemia interactome. The curated interactome includes proteins that are deregulated after cerebral ischemia in human and experimental stroke. Network analysis of the interactome revealed a rich-club organization indicating the presence of a densely interconnected hub structure of prominent contributors to disease pathogenesis. Functional annotation of the interactome uncovered prominent pathways and highlighted the critical role of the complement and coagulation cascade in the initiation and amplification of injury starting by activation of the rich-club. We performed an in-silico screen for putative interventions that have pleiotropic effects on rich-club components and we identified estrogen as a prominent candidate. Our findings show that complex network analysis of disease related interactomes may lead to a better understanding of pathogenic mechanisms and provide cost-effective and mechanism-based discovery of candidate therapeutics. PMID:26310627

Novel Evasion Mechanisms of the Classical Complement Pathway

PubMed Central

Garcia, Brandon L.; Zwarthoff, Seline A.; Rooijakkers, Suzan H. M.; Geisbrecht, Brian V.

2016-01-01

Complement is a network of soluble and cell surface-associated proteins which gives rise to a self-amplifying, yet tightly regulated system with fundamental roles in immune surveillance and clearance. Complement becomes activated on the surface of ‘non-self’ cells by one of three initiating mechanisms known as the classical, lectin, or alternative pathways. Evasion of complement function is a hallmark of invasive pathogens and hematophagous organisms. While many complement inhibition strategies hinge on hijacking activities of endogenous complement regulatory proteins, an increasing number of uniquely evolved evasion molecules have been discovered over the past decade. In this review we focus on several recent investigations which have revealed mechanistically distinct inhibitors of the classical pathway. Because the classical pathway is an important and specific mediator of various autoimmune and inflammatory disorders, in-depth knowledge of novel evasion mechanisms could direct future development of therapeutic anti-inflammatory molecules. PMID:27591336

Novel Evasion Mechanisms of the Classical Complement Pathway.

PubMed

Garcia, Brandon L; Zwarthoff, Seline A; Rooijakkers, Suzan H M; Geisbrecht, Brian V

2016-09-15

Complement is a network of soluble and cell surface-associated proteins that gives rise to a self-amplifying, yet tightly regulated system with fundamental roles in immune surveillance and clearance. Complement becomes activated on the surface of nonself cells by one of three initiating mechanisms known as the classical, lectin, and alternative pathways. Evasion of complement function is a hallmark of invasive pathogens and hematophagous organisms. Although many complement-inhibition strategies hinge on hijacking activities of endogenous complement regulatory proteins, an increasing number of uniquely evolved evasion molecules have been discovered over the past decade. In this review, we focus on several recent investigations that revealed mechanistically distinct inhibitors of the classical pathway. Because the classical pathway is an important and specific mediator of various autoimmune and inflammatory disorders, in-depth knowledge of novel evasion mechanisms could direct future development of therapeutic anti-inflammatory molecules. Copyright © 2016 by The American Association of Immunologists, Inc.

Metabolomics and In-Silico Analysis Reveal Critical Energy Deregulations in Animal Models of Parkinson’s Disease

PubMed Central

Poliquin, Pierre O.; Chen, Jingkui; Cloutier, Mathieu; Trudeau, Louis-Éric; Jolicoeur, Mario

2013-01-01

Parkinson’s disease (PD) is a multifactorial disease known to result from a variety of factors. Although age is the principal risk factor, other etiological mechanisms have been identified, including gene mutations and exposure to toxins. Deregulation of energy metabolism, mostly through the loss of complex I efficiency, is involved in disease progression in both the genetic and sporadic forms of the disease. In this study, we investigated energy deregulation in the cerebral tissue of animal models (genetic and toxin induced) of PD using an approach that combines metabolomics and mathematical modelling. In a first step, quantitative measurements of energy-related metabolites in mouse brain slices revealed most affected pathways. A genetic model of PD, the Park2 knockout, was compared to the effect of CCCP, a complex I blocker. Model simulated and experimental results revealed a significant and sustained decrease in ATP after CCCP exposure, but not in the genetic mice model. In support to data analysis, a mathematical model of the relevant metabolic pathways was developed and calibrated onto experimental data. In this work, we show that a short-term stress response in nucleotide scavenging is most probably induced by the toxin exposure. In turn, the robustness of energy-related pathways in the model explains how genetic perturbations, at least in young animals, are not sufficient to induce significant changes at the metabolite level. PMID:23935941

Complement Evasion by Pathogenic Leptospira.

PubMed

Fraga, Tatiana Rodrigues; Isaac, Lourdes; Barbosa, Angela Silva

2016-01-01

Leptospirosis is a neglected infectious disease caused by spirochetes from the genus Leptospira . Pathogenic microorganisms, notably those which reach the blood circulation such as Leptospira , have evolved multiple strategies to escape the host complement system, which is important for innate and acquired immunity. Leptospira avoid complement-mediated killing through: (i) recruitment of host complement regulators; (ii) acquisition of host proteases that cleave complement proteins on the bacterial surface; and, (iii) secretion of proteases that inactivate complement proteins in the Leptospira surroundings. The recruitment of host soluble complement regulatory proteins includes the acquisition of Factor H (FH) and FH-like-1 (alternative pathway), C4b-binding protein (C4BP) (classical and lectin pathways), and vitronectin (Vn) (terminal pathway). Once bound to the leptospiral surface, FH and C4BP retain cofactor activity of Factor I in the cleavage of C3b and C4b, respectively. Vn acquisition by leptospires may result in terminal pathway inhibition by blocking C9 polymerization. The second evasion mechanism lies in plasminogen (PLG) binding to the leptospiral surface. In the presence of host activators, PLG is converted to enzymatically active plasmin, which is able to degrade C3b, C4b, and C5 at the surface of the pathogen. A third strategy used by leptospires to escape from complement system is the active secretion of proteases. Pathogenic, but not saprophytic leptospires, are able to secrete metalloproteases that cleave C3 (central complement molecule), Factor B (alternative pathway), and C4 and C2 (classical and lectin pathways). The purpose of this review is to fully explore these complement evasion mechanisms, which act together to favor Leptospira survival and multiplication in the host.

Complement Evasion by Pathogenic Leptospira

PubMed Central

Fraga, Tatiana Rodrigues; Isaac, Lourdes; Barbosa, Angela Silva

2016-01-01

Leptospirosis is a neglected infectious disease caused by spirochetes from the genus Leptospira. Pathogenic microorganisms, notably those which reach the blood circulation such as Leptospira, have evolved multiple strategies to escape the host complement system, which is important for innate and acquired immunity. Leptospira avoid complement-mediated killing through: (i) recruitment of host complement regulators; (ii) acquisition of host proteases that cleave complement proteins on the bacterial surface; and, (iii) secretion of proteases that inactivate complement proteins in the Leptospira surroundings. The recruitment of host soluble complement regulatory proteins includes the acquisition of Factor H (FH) and FH-like-1 (alternative pathway), C4b-binding protein (C4BP) (classical and lectin pathways), and vitronectin (Vn) (terminal pathway). Once bound to the leptospiral surface, FH and C4BP retain cofactor activity of Factor I in the cleavage of C3b and C4b, respectively. Vn acquisition by leptospires may result in terminal pathway inhibition by blocking C9 polymerization. The second evasion mechanism lies in plasminogen (PLG) binding to the leptospiral surface. In the presence of host activators, PLG is converted to enzymatically active plasmin, which is able to degrade C3b, C4b, and C5 at the surface of the pathogen. A third strategy used by leptospires to escape from complement system is the active secretion of proteases. Pathogenic, but not saprophytic leptospires, are able to secrete metalloproteases that cleave C3 (central complement molecule), Factor B (alternative pathway), and C4 and C2 (classical and lectin pathways). The purpose of this review is to fully explore these complement evasion mechanisms, which act together to favor Leptospira survival and multiplication in the host. PMID:28066433

Integrative Genome-Scale Analysis Identifies Epigenetic Mechanisms of Transcriptional Deregulation in Unfavorable Neuroblastomas.

PubMed

Henrich, Kai-Oliver; Bender, Sebastian; Saadati, Maral; Dreidax, Daniel; Gartlgruber, Moritz; Shao, Chunxuan; Herrmann, Carl; Wiesenfarth, Manuel; Parzonka, Martha; Wehrmann, Lea; Fischer, Matthias; Duffy, David J; Bell, Emma; Torkov, Alica; Schmezer, Peter; Plass, Christoph; Höfer, Thomas; Benner, Axel; Pfister, Stefan M; Westermann, Frank

2016-09-15

The broad clinical spectrum of neuroblastoma ranges from spontaneous regression to rapid progression despite intensive multimodal therapy. This diversity is not fully explained by known genetic aberrations, suggesting the possibility of epigenetic involvement in pathogenesis. In pursuit of this hypothesis, we took an integrative approach to analyze the methylomes, transcriptomes, and copy number variations in 105 cases of neuroblastoma, complemented by primary tumor- and cell line-derived global histone modification analyses and epigenetic drug treatment in vitro We found that DNA methylation patterns identify divergent patient subgroups with respect to survival and clinicobiologic variables, including amplified MYCN Transcriptome integration and histone modification-based definition of enhancer elements revealed intragenic enhancer methylation as a mechanism for high-risk-associated transcriptional deregulation. Furthermore, in high-risk neuroblastomas, we obtained evidence for cooperation between PRC2 activity and DNA methylation in blocking tumor-suppressive differentiation programs. Notably, these programs could be re-activated by combination treatments, which targeted both PRC2 and DNA methylation. Overall, our results illuminate how epigenetic deregulation contributes to neuroblastoma pathogenesis, with novel implications for its diagnosis and therapy. Cancer Res; 76(18); 5523-37. ©2016 AACR. ©2016 American Association for Cancer Research.

Evasion Mechanisms Used by Pathogens to Escape the Lectin Complement Pathway.

PubMed

Rosbjerg, Anne; Genster, Ninette; Pilely, Katrine; Garred, Peter

2017-01-01

The complement system is a crucial defensive network that protects the host against invading pathogens. It is part of the innate immune system and can be initiated via three pathways: the lectin, classical and alternative activation pathway. Overall the network compiles a group of recognition molecules that bind specific patterns on microbial surfaces, a group of associated proteases that initiates the complement cascade, and a group of proteins that interact in proteolytic complexes or the terminal pore-forming complex. In addition, various regulatory proteins are important for controlling the level of activity. The result is a pro-inflammatory response meant to combat foreign microbes. Microbial elimination is, however, not a straight forward procedure; pathogens have adapted to their environment by evolving a collection of evasion mechanisms that circumvent the human complement system. Complement evasion strategies features different ways of exploiting human complement proteins and moreover features different pathogen-derived proteins that interfere with the normal processes. Accumulated, these mechanisms target all three complement activation pathways as well as the final common part of the cascade. This review will cover the currently known lectin pathway evasion mechanisms and give examples of pathogens that operate these to increase their chance of invasion, survival and dissemination.

THE PATHOPHYSIOLOGY OF GEOGRAPHIC ATROPHY SECONDARY TO AGE-RELATED MACULAR DEGENERATION AND THE COMPLEMENT PATHWAY AS A THERAPEUTIC TARGET

PubMed Central

Schmidt-Erfurth, Ursula; van Lookeren Campagne, Menno; Henry, Erin C.; Brittain, Christopher

2017-01-01

Purpose: Geographic atrophy (GA) is an advanced, vision-threatening form of age-related macular degeneration (AMD) affecting approximately five million individuals worldwide. To date, there are no approved therapeutics for GA treatment; however, several are in clinical trials. This review focuses on the pathophysiology of GA, particularly the role of complement cascade dysregulation and emerging therapies targeting the complement cascade. Methods: Primary literature search on PubMed for GA, complement cascade in age-related macular degeneration. ClinicalTrials.gov was searched for natural history studies in GA and clinical trials of drugs targeting the complement cascade for GA. Results: Cumulative damage to the retina by aging, environmental stress, and other factors triggers inflammation via multiple pathways, including the complement cascade. When regulatory components in these pathways are compromised, as with several GA-linked genetic risk factors in the complement cascade, chronic inflammation can ultimately lead to the retinal cell death characteristic of GA. Complement inhibition has been identified as a key candidate for therapeutic intervention, and drugs targeting the complement pathway are currently in clinical trials. Conclusion: The complement cascade is a strategic target for GA therapy. Further research, including on natural history and genetics, is crucial to expand the understanding of GA pathophysiology and identify effective therapeutic targets. PMID:27902638

Integrated analysis of breast cancer cell lines reveals unique signaling pathways

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heiser, Laura M.; Wang, Nicholas J.; Talcott, Carolyn L.

Cancer is a heterogeneous disease resulting from the accumulation of genetic defects that negatively impact control of cell division, motility, adhesion and apoptosis. Deregulation in signaling along the EGFR-MAPK pathway is common in breast cancer, though the manner in which deregulation occurs varies between both individuals and cancer subtypes. We were interested in identifying subnetworks within the EGFR-MAPK pathway that are similarly deregulated across subsets of breast cancers. To that end, we mapped genomic, transcriptional and proteomic profiles for 30 breast cancer cell lines onto a curated Pathway Logic symbolic systems model of EGFR-MEK signaling. This model was comprised ofmore » 539 molecular states and 396 rules governing signaling between active states. We analyzed these models and identified several subtype specific subnetworks, including one that suggested PAK1 is particularly important in regulating the MAPK cascade when it is over-expressed. We hypothesized that PAK1 overexpressing cell lines would have increased sensitivity to MEK inhibitors. We tested this experimentally by measuring quantitative responses of 20 breast cancer cell lines to three MEK inhibitors. We found that PAK1 over-expressing luminal breast cancer cell lines are significantly more sensitive to MEK inhibition as compared to those that express PAK1 at low levels. This indicates that PAK1 over-expression may be a useful clinical marker to identify patient populations that may be sensitive to MEK inhibitors. All together, our results support the utility of symbolic system biology models for identification of therapeutic approaches that will be effective against breast cancer subsets.« less

Integrated analysis of breast cancer cell lines reveals unique signaling pathways.

PubMed

Heiser, Laura M; Wang, Nicholas J; Talcott, Carolyn L; Laderoute, Keith R; Knapp, Merrill; Guan, Yinghui; Hu, Zhi; Ziyad, Safiyyah; Weber, Barbara L; Laquerre, Sylvie; Jackson, Jeffrey R; Wooster, Richard F; Kuo, Wen Lin; Gray, Joe W; Spellman, Paul T

2009-01-01

Cancer is a heterogeneous disease resulting from the accumulation of genetic defects that negatively impact control of cell division, motility, adhesion and apoptosis. Deregulation in signaling along the EgfR-MAPK pathway is common in breast cancer, though the manner in which deregulation occurs varies between both individuals and cancer subtypes. We were interested in identifying subnetworks within the EgfR-MAPK pathway that are similarly deregulated across subsets of breast cancers. To that end, we mapped genomic, transcriptional and proteomic profiles for 30 breast cancer cell lines onto a curated Pathway Logic symbolic systems model of EgfR-MAPK signaling. This model was composed of 539 molecular states and 396 rules governing signaling between active states. We analyzed these models and identified several subtype-specific subnetworks, including one that suggested Pak1 is particularly important in regulating the MAPK cascade when it is over-expressed. We hypothesized that Pak1 over-expressing cell lines would have increased sensitivity to Mek inhibitors. We tested this experimentally by measuring quantitative responses of 20 breast cancer cell lines to three Mek inhibitors. We found that Pak1 over-expressing luminal breast cancer cell lines are significantly more sensitive to Mek inhibition compared to those that express Pak1 at low levels. This indicates that Pak1 over-expression may be a useful clinical marker to identify patient populations that may be sensitive to Mek inhibitors. All together, our results support the utility of symbolic system biology models for identification of therapeutic approaches that will be effective against breast cancer subsets.

The Pathways Framework Meets Consumer Culture: Young People, Careers, and Commitment

ERIC Educational Resources Information Center

Vaughan, Karen

2005-01-01

This article engages with current debates in New Zealand over the legitimacy of various young people's activities within a transition-to-work framework based around the metaphor of "pathways". The article argues for a more complex understanding of the imperatives young people now face in choosing careers within a deregulated, seamless…

Expression of glnB and a glnB-Like Gene (glnK) in a Ribulose Bisphosphate Carboxylase/Oxygenase-Deficient Mutant of Rhodobacter sphaeroides

PubMed Central

Qian, Yilei; Tabita, F. Robert

1998-01-01

In a ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO)-deficient mutant of Rhodobacter sphaeroides, strain 16PHC, nitrogenase activity was derepressed in the presence of ammonia under photoheterotrophic growth conditions. Previous studies also showed that reintroduction of a functional RubisCO and Calvin-Benson-Bassham (CBB) pathway suppressed the deregulation of nitrogenase synthesis in this strain. In this study, the derepression of nitrogenase synthesis in the presence of ammonia in strain 16PHC was further explored by using a glnB::lacZ fusion, since the product of the glnB gene is known to have a negative effect on ammonia-regulated nif control. It was found that glnB expression was repressed in strain 16PHC under photoheterotrophic growth conditions with either ammonia or glutamate as the nitrogen source; glutamine synthetase (GS) levels were also affected in this strain. However, when cells regained a functional CBB pathway by trans complementation of the deleted genes, wild-type levels of GS and glnB expression were restored. Furthermore, a glnB-like gene, glnK, was isolated from this organism, and its expression was found to be under tight nitrogen control in the wild type. Surprisingly, glnK expression was found to be derepressed in strain 16PHC under photoheterotrophic conditions in the presence of ammonia. PMID:9721307

PDGF-C is an EWS/FLI induced transforming growth factor in Ewing Family Tumors

PubMed Central

Zwerner, Jeffrey P.; May, William A.

2013-01-01

The aberrant transcription factors associated with many human malignancies function by deregulation of tumorigenic pathways. However, identification of these pathways has come slowly. Virtually all cases of Ewing’s Sarcoma and peripheral Primitive Neuroectodermal Tumor (PNET) are associated with aberrant transcription factors which fuse amino-terminal EWS with the DNA binding moiety of an ETS transcription factor (FLI-1 in 90% of cases). Attempts to identify the downstream targets of these chimeras in the Ewing Family Tumors (EFT) on the basis of differential gene regulation have produced little association with tumor biology. As an alternative approach, we have used highly efficient retroviral systems to biologically screen cDNA derived from cells transformed by EWS/FLI-1. We have identified the recently described PDGF-C as target of EWS/ETS transcriptional deregulation. This transcriptional deregulation is specific to EWS/FLI. PDGF-C possesses substantial biologic activity in vitro and in vivo. It is expressed in EFT cell lines and in primary tumors. Within these EFT cell lines, PDGF-C expression is dependent upon EWS/FLI activity. These results suggest that PDGF-C may be a significant mediator of EWS/FLI driven oncogenesis. PMID:11313995

Genomancy: predicting tumour response to cancer therapy based on the oracle of genetics.

PubMed

Williams, P D; Lee, J K; Theodorescu, D

2009-01-01

Cells are complex systems that regulate a multitude of biologic pathways involving a diverse array of molecules. Cancer can develop when these pathways become deregulated as a result of mutations in the genes coding for these proteins or of epigenetic changes that affect gene expression, or both1,2. The diversity and interconnectedness of these pathways and their molecular components implies that a variety of mutations may lead to tumorigenic cellular deregulation3-6. This variety, combined with the requirement to overcome multiple anticancer defence mechanisms7, contributes to the heterogeneous nature of cancer. Consequently, tumours with similar histology may vary in their underlying molecular circuitry8-10, with resultant differences in biologic behaviour, manifested in proliferation rate, invasiveness, metastatic potential, and unfortunately, response to cytotoxic therapy. Thus, cancer can be thought of as a family of related tumour subtypes, highlighting the need for individualized prediction both of disease progression and of treatment response, based on the molecular characteristics of the tumour.

Survivin Selectively Modulates Genes Deregulated in Human Leukemia Stem Cells

PubMed Central

Fukuda, Seiji; Abe, Mariko; Onishi, Chie; Taketani, Takeshi; Purevsuren, Jamiyan; Yamaguchi, Seiji; Conway, Edward M.; Pelus, Louis M.

2011-01-01

ITD-Flt3 mutations are detected in leukemia stem cells (LSCs) in acute myeloid leukemia (AML) patients. While antagonizing Survivin normalizes ITD-Flt3-induced acute leukemia, it also impairs hematopoietic stem cell (HSC) function, indicating that identification of differences in signaling pathways downstream of Survivin between LSC and HSC are crucial to develop selective Survivin-based therapeutic strategies for AML. Using a Survivin-deletion model, we identified 1,096 genes regulated by Survivin in ITD-Flt3-transformed c-kit+, Sca-1+, and lineageneg (KSL) cells, of which 137 are deregulated in human LSC. Of the 137, 124 genes were regulated by Survivin exclusively in ITD-Flt3+ KSL cells but not in normal CD34neg KSL cells. Survivin-regulated genes in LSC connect through a network associated with the epidermal growth factor receptor signaling pathway and falls into various functional categories independent of effects on apoptosis. Pathways downstream of Survivin in LSC that are distinct from HSC can be potentially targeted for selective anti-LSC therapy. PMID:21253548

CREB-binding protein (CBP) regulates β-adrenoceptor (β-AR)−mediated apoptosis

PubMed Central

Lee, Y Y; Moujalled, D; Doerflinger, M; Gangoda, L; Weston, R; Rahimi, A; de Alboran, I; Herold, M; Bouillet, P; Xu, Q; Gao, X; Du, X-J; Puthalakath, H

2013-01-01

Catecholamines regulate the β-adrenoceptor/cyclic AMP-regulated protein kinase A (cAMP/PKA) pathway. Deregulation of this pathway can cause apoptotic cell death and is implicated in a range of human diseases, such as neuronal loss during aging, cardiomyopathy and septic shock. The molecular mechanism of this process is, however, only poorly understood. Here we demonstrate that the β-adrenoceptor/cAMP/PKA pathway triggers apoptosis through the transcriptional induction of the pro-apoptotic BH3-only Bcl-2 family member Bim in tissues such as the thymus and the heart. In these cell types, the catecholamine-mediated apoptosis is abrogated by loss of Bim. Induction of Bim is driven by the transcriptional co-activator CBP (CREB-binding protein) together with the proto-oncogene c-Myc. Association of CBP with c-Myc leads to altered histone acetylation and methylation pattern at the Bim promoter site. Our findings have implications for understanding pathophysiology associated with a deregulated neuroendocrine system and for developing novel therapeutic strategies for these diseases. PMID:23579242

Evasion Mechanisms Used by Pathogens to Escape the Lectin Complement Pathway

PubMed Central

Rosbjerg, Anne; Genster, Ninette; Pilely, Katrine; Garred, Peter

2017-01-01

The complement system is a crucial defensive network that protects the host against invading pathogens. It is part of the innate immune system and can be initiated via three pathways: the lectin, classical and alternative activation pathway. Overall the network compiles a group of recognition molecules that bind specific patterns on microbial surfaces, a group of associated proteases that initiates the complement cascade, and a group of proteins that interact in proteolytic complexes or the terminal pore-forming complex. In addition, various regulatory proteins are important for controlling the level of activity. The result is a pro-inflammatory response meant to combat foreign microbes. Microbial elimination is, however, not a straight forward procedure; pathogens have adapted to their environment by evolving a collection of evasion mechanisms that circumvent the human complement system. Complement evasion strategies features different ways of exploiting human complement proteins and moreover features different pathogen-derived proteins that interfere with the normal processes. Accumulated, these mechanisms target all three complement activation pathways as well as the final common part of the cascade. This review will cover the currently known lectin pathway evasion mechanisms and give examples of pathogens that operate these to increase their chance of invasion, survival and dissemination. PMID:28553281

Transposable Element Misregulation Is Linked to the Divergence between Parental piRNA Pathways in Drosophila Hybrids

PubMed Central

Romero-Soriano, Valèria; Modolo, Laurent; Lopez-Maestre, Hélène; Mugat, Bruno; Pessia, Eugénie; Chambeyron, Séverine; Vieira, Cristina

2017-01-01

Abstract Interspecific hybridization is a genomic stress condition that leads to the activation of transposable elements (TEs) in both animals and plants. In hybrids between Drosophila buzzatii and Drosophila koepferae, mobilization of at least 28 TEs has been described. However, the molecular mechanisms underlying this TE release remain poorly understood. To give insight on the causes of this TE activation, we performed a TE transcriptomic analysis in ovaries (notorious for playing a major role in TE silencing) of parental species and their F1 and backcrossed (BC) hybrids. We find that 15.2% and 10.6% of the expressed TEs are deregulated in F1 and BC1 ovaries, respectively, with a bias toward overexpression in both cases. Although differences between parental piRNA (Piwi-interacting RNA) populations explain only partially these results, we demonstrate that piRNA pathway proteins have divergent sequences and are differentially expressed between parental species. Thus, a functional divergence of the piRNA pathway between parental species, together with some differences between their piRNA pools, might be at the origin of hybrid instabilities and ultimately cause TE misregulation in ovaries. These analyses were complemented with the study of F1 testes, where TEs tend to be less expressed than in D. buzzatii. This can be explained by an increase in piRNA production, which probably acts as a defence mechanism against TE instability in the male germline. Hence, we describe a differential impact of interspecific hybridization in testes and ovaries, which reveals that TE expression and regulation are sex-biased. PMID:28854624

Deregulated hedgehog pathway signaling is inhibited by the smoothened antagonist LDE225 (Sonidegib) in chronic phase chronic myeloid leukaemia

PubMed Central

Irvine, David A.; Zhang, Bin; Kinstrie, Ross; Tarafdar, Anuradha; Morrison, Heather; Campbell, Victoria L.; Moka, Hothri A.; Ho, Yinwei; Nixon, Colin; Manley, Paul W.; Wheadon, Helen; Goodlad, John R.; Holyoake, Tessa L.; Bhatia, Ravi; Copland, Mhairi

2016-01-01

Targeting the Hedgehog (Hh) pathway represents a potential leukaemia stem cell (LSC)-directed therapy which may compliment tyrosine kinase inhibitors (TKIs) to eradicate LSC in chronic phase (CP) chronic myeloid leukaemia (CML). We set out to elucidate the role of Hh signaling in CP-CML and determine if inhibition of Hh signaling, through inhibition of smoothened (SMO), was an effective strategy to target CP-CML LSC. Assessment of Hh pathway gene and protein expression demonstrated that the Hh pathway is activated in CD34+ CP-CML stem/progenitor cells. LDE225 (Sonidegib), a small molecule, clinically investigated SMO inhibitor, used alone and in combination with nilotinib, inhibited the Hh pathway in CD34+ CP-CML cells, reducing the number and self-renewal capacity of CML LSC in vitro. The combination had no effect on normal haemopoietic stem cells. When combined, LDE225 + nilotinib reduced CD34+ CP-CML cell engraftment in NSG mice and, upon administration to EGFP+ /SCLtTA/TRE-BCR-ABL mice, the combination enhanced survival with reduced leukaemia development in secondary transplant recipients. In conclusion, the Hh pathway is deregulated in CML stem and progenitor cells. We identify Hh pathway inhibition, in combination with nilotinib, as a potentially effective therapeutic strategy to improve responses in CP-CML by targeting both stem and progenitor cells. PMID:27157927

Ras-mediated deregulation of the circadian clock in cancer.

PubMed

Relógio, Angela; Thomas, Philippe; Medina-Pérez, Paula; Reischl, Silke; Bervoets, Sander; Gloc, Ewa; Riemer, Pamela; Mang-Fatehi, Shila; Maier, Bert; Schäfer, Reinhold; Leser, Ulf; Herzel, Hanspeter; Kramer, Achim; Sers, Christine

2014-01-01

Circadian rhythms are essential to the temporal regulation of molecular processes in living systems and as such to life itself. Deregulation of these rhythms leads to failures in biological processes and eventually to the manifestation of pathological phenotypes including cancer. To address the questions as to what are the elicitors of a disrupted clock in cancer, we applied a systems biology approach to correlate experimental, bioinformatics and modelling data from several cell line models for colorectal and skin cancer. We found strong and weak circadian oscillators within the same type of cancer and identified a set of genes, which allows the discrimination between the two oscillator-types. Among those genes are IFNGR2, PITX2, RFWD2, PPARγ, LOXL2, Rab6 and SPARC, all involved in cancer-related pathways. Using a bioinformatics approach, we extended the core-clock network and present its interconnection to the discriminative set of genes. Interestingly, such gene signatures link the clock to oncogenic pathways like the RAS/MAPK pathway. To investigate the potential impact of the RAS/MAPK pathway - a major driver of colorectal carcinogenesis - on the circadian clock, we used a computational model which predicted that perturbation of BMAL1-mediated transcription can generate the circadian phenotypes similar to those observed in metastatic cell lines. Using an inducible RAS expression system, we show that overexpression of RAS disrupts the circadian clock and leads to an increase of the circadian period while RAS inhibition causes a shortening of period length, as predicted by our mathematical simulations. Together, our data demonstrate that perturbations induced by a single oncogene are sufficient to deregulate the mammalian circadian clock.

HTLV Deregulation of the NF-κB Pathway: An Update on Tax and Antisense Proteins Role.

PubMed

Fochi, Stefania; Mutascio, Simona; Bertazzoni, Umberto; Zipeto, Donato; Romanelli, Maria G

2018-01-01

Human T-cell lymphotropic virus type 1 (HTLV-1) is the causative agent of adult T-cell leukemia (ATL), an aggressive CD4 + /CD25 + T-cell malignancy and of a severe neurodegenerative disease, HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP). The chronic activation or deregulation of the canonical and non-canonical nuclear factor kappa B (NF-κB) pathways play a crucial role in tumorigenesis. The HTLV-1 Tax-1 oncoprotein is a potent activator of the NF-κB transcription factors and the NF-κB response is required for promoting the development of HTLV-1 transformed cell lines. The homologous retrovirus HTLV-2, which also expresses a Tax-2 transforming protein, is not associated with ATL. In this review, we provide an updated synopsis of the role of Tax-1 in the deregulation of the NF-κB pathway, highlighting the differences with the homologous Tax-2. Special emphasis is directed toward the understanding of the molecular mechanisms involved in NF-κB activation resulting from Tax interaction with host factors affecting several cellular processes, such as cell cycle, apoptosis, senescence, cell proliferation, autophagy, and post-translational modifications. We also discuss the current knowledge on the role of the antisense viral protein HBZ in down-regulating the NF-κB activation induced by Tax, and its implication in cellular senescence. In addition, we review the recent studies on the mechanism of HBZ-mediated inhibition of NF-κB activity as compared to that exerted by the HTLV-2 antisense protein, APH-2. Finally, we discuss recent advances aimed at understanding the role exerted in the development of ATL by the perturbation of NF-κB pathway by viral regulatory proteins.

HTLV Deregulation of the NF-κB Pathway: An Update on Tax and Antisense Proteins Role

PubMed Central

Fochi, Stefania; Mutascio, Simona; Bertazzoni, Umberto; Zipeto, Donato; Romanelli, Maria G.

2018-01-01

Human T-cell lymphotropic virus type 1 (HTLV-1) is the causative agent of adult T-cell leukemia (ATL), an aggressive CD4+/CD25+ T-cell malignancy and of a severe neurodegenerative disease, HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP). The chronic activation or deregulation of the canonical and non-canonical nuclear factor kappa B (NF-κB) pathways play a crucial role in tumorigenesis. The HTLV-1 Tax-1 oncoprotein is a potent activator of the NF-κB transcription factors and the NF-κB response is required for promoting the development of HTLV-1 transformed cell lines. The homologous retrovirus HTLV-2, which also expresses a Tax-2 transforming protein, is not associated with ATL. In this review, we provide an updated synopsis of the role of Tax-1 in the deregulation of the NF-κB pathway, highlighting the differences with the homologous Tax-2. Special emphasis is directed toward the understanding of the molecular mechanisms involved in NF-κB activation resulting from Tax interaction with host factors affecting several cellular processes, such as cell cycle, apoptosis, senescence, cell proliferation, autophagy, and post-translational modifications. We also discuss the current knowledge on the role of the antisense viral protein HBZ in down-regulating the NF-κB activation induced by Tax, and its implication in cellular senescence. In addition, we review the recent studies on the mechanism of HBZ-mediated inhibition of NF-κB activity as compared to that exerted by the HTLV-2 antisense protein, APH-2. Finally, we discuss recent advances aimed at understanding the role exerted in the development of ATL by the perturbation of NF-κB pathway by viral regulatory proteins. PMID:29515558

Ectromelia virus inhibitor of complement enzymes protects intracellular mature virus and infected cells from mouse complement.

PubMed

Moulton, Elizabeth A; Bertram, Paula; Chen, Nanhai; Buller, R Mark L; Atkinson, John P

2010-09-01

Poxviruses produce complement regulatory proteins to subvert the host's immune response. Similar to the human pathogen variola virus, ectromelia virus has a limited host range and provides a mouse model where the virus and the host's immune response have coevolved. We previously demonstrated that multiple components (C3, C4, and factor B) of the classical and alternative pathways are required to survive ectromelia virus infection. Complement's role in the innate and adaptive immune responses likely drove the evolution of a virus-encoded virulence factor that regulates complement activation. In this study, we characterized the ectromelia virus inhibitor of complement enzymes (EMICE). Recombinant EMICE regulated complement activation on the surface of CHO cells, and it protected complement-sensitive intracellular mature virions (IMV) from neutralization in vitro. It accomplished this by serving as a cofactor for the inactivation of C3b and C4b and by dissociating the catalytic domain of the classical pathway C3 convertase. Infected murine cells initiated synthesis of EMICE within 4 to 6 h postinoculation. The levels were sufficient in the supernatant to protect the IMV, upon release, from complement-mediated neutralization. EMICE on the surface of infected murine cells also reduced complement activation by the alternative pathway. In contrast, classical pathway activation by high-titer antibody overwhelmed EMICE's regulatory capacity. These results suggest that EMICE's role is early during infection when it counteracts the innate immune response. In summary, ectromelia virus produced EMICE within a few hours of an infection, and EMICE in turn decreased complement activation on IMV and infected cells.

The Epoxyeicosatrienoic Acid Pathway Enhances Hepatic Insulin Signaling and is Repressed in Insulin-Resistant Mouse Liver*

PubMed Central

Schäfer, Alexander; Neschen, Susanne; Kahle, Melanie; Sarioglu, Hakan; Gaisbauer, Tobias; Imhof, Axel; Adamski, Jerzy; Hauck, Stefanie M.; Ueffing, Marius

2015-01-01

Although it is widely accepted that ectopic lipid accumulation in the liver is associated with hepatic insulin resistance, the underlying molecular mechanisms have not been well characterized. Here we employed time resolved quantitative proteomic profiling of mice fed a high fat diet to determine which pathways were affected during the transition of the liver to an insulin-resistant state. We identified several metabolic pathways underlying altered protein expression. In order to test the functional impact of a critical subset of these alterations, we focused on the epoxyeicosatrienoic acid (EET) eicosanoid pathway, whose deregulation coincided with the onset of hepatic insulin resistance. These results suggested that EETs may be positive modulators of hepatic insulin signaling. Analyzing EET activity in primary hepatocytes, we found that EETs enhance insulin signaling on the level of Akt. In contrast, EETs did not influence insulin receptor or insulin receptor substrate-1 phosphorylation. This effect was mediated through the eicosanoids, as overexpression of the deregulated enzymes in absence of arachidonic acid had no impact on insulin signaling. The stimulation of insulin signaling by EETs and depression of the pathway in insulin resistant liver suggest a likely role in hepatic insulin resistance. Our findings support therapeutic potential for inhibiting EET degradation. PMID:26070664

Sex matters: Systemic complement activity of female C57BL/6J and BALB/cJ mice is limited by serum terminal pathway components.

PubMed

Kotimaa, Juha; Klar-Mohammad, Ngaisah; Gueler, Faikah; Schilders, Geurt; Jansen, Aswin; Rutjes, Helma; Daha, Mohamed R; van Kooten, Cees

2016-08-01

Experimental mouse models have been extensively used to elucidate the role of the complement system in different diseases and injuries. Contribution of gender has revealed an intriguing gender specific difference; female mice often show protection against most complement driven injuries such as ischemia/reperfusion injury, graft rejection and sepsis. Interestingly, early studies to the mouse complement system revealed that female mice have very low total complement activity (CH50), which is related to androgen regulation of hepatic complement synthesis. Here, our aim was to understand at which level the female specific differences in mouse complement resides. We have used recently developed complement assays to study the functional activities of female and male mice at the level of C3 and C9 activation, and furthermore assayed key complement factor levels in serum of age-matched female and male C57BL/6 mice. Our results show that the female mice have normal complement cascade functionality at the level of C3 activation, which was supported by determinations of early complement factors. However, all pathways are strongly reduced at the level of C9 activation, suggesting a terminal pathway specific difference. This was in line with C6 and C9 measurements, showing strongly decreased levels in females. Furthermore, similar gender differences were also found in BALB/cJ mice, but not in CD-1 mice. Our results clearly demonstrate that the complement system in females of frequently used mouse strains is restricted by the terminal pathway components and that the perceived female specific protection against experimental disease and injury might be in part explained by the inability promote inflammation through C5b-9. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

The Group B Streptococcus–Secreted Protein CIP Interacts with C4, Preventing C3b Deposition via the Lectin and Classical Complement Pathways

PubMed Central

Pietrocola, Giampiero; Rindi, Simonetta; Rosini, Roberto; Buccato, Scilla

2016-01-01

The group B Streptococcus (GBS) is a leading cause of neonatal invasive disease. GBS bacteria are surrounded by a thick capsular polysaccharide that is a potent inhibitor of complement deposition via the alternative pathway. Several of its surface molecules can however activate the classical and lectin complement pathways, rendering this species still vulnerable to phagocytic killing. In this study we have identified a novel secreted protein named complement interfering protein (CIP) that downregulates complement activation via the classical and lectin pathways, but not the alternative pathway. The CIP protein showed high affinity toward C4b and inhibited its interaction with C2, presumably preventing the formation of the C4bC2a convertase. Addition of recombinant CIP to GBS cip-negative bacteria resulted in decreased deposition of C3b on their surface and in diminished phagocytic killing in a whole-blood assay. Our data reveal a novel strategy exploited by GBS to counteract innate immunity and could be valuable for the development of anti-infective agents against this important pathogen. PMID:26608922

MicroRNA meta-signature of oral cancer: evidence from a meta-analysis.

PubMed

Zeljic, Katarina; Jovanovic, Ivan; Jovanovic, Jasmina; Magic, Zvonko; Stankovic, Aleksandra; Supic, Gordana

2018-03-01

It was the aim of the study to identify commonly deregulated miRNAs in oral cancer patients by performing a meta-analysis of previously published miRNA expression profiles in cancer and matched normal non-cancerous tissue in such patients. Meta-analysis included seven independent studies analyzed by a vote-counting method followed by bioinformatic enrichment analysis. Amongst seven independent studies included in the meta-analysis, 20 miRNAs were found to be deregulated in oral cancer when compared with non-cancerous tissue. Eleven miRNAs were consistently up-regulated in three or more studies (miR-21-5p, miR-31-5p, miR-135b-5p, miR-31-3p, miR-93-5p, miR-34b-5p, miR-424-5p, miR-18a-5p, miR-455-3p, miR-450a-5p, miR-21-3p), and nine were down-regulated (miR-139-5p, miR-30a-3p, miR-376c-3p, miR-885-5p, miR-375, miR-486-5p, miR-411-5p, miR-133a-3p, miR-30a-5p). The meta-signature of identified miRNAs was functionally characterized by KEGG enrichment analysis. Twenty-four KEGG pathways were significantly enriched, and TGF-beta signaling was the most enriched signaling pathway. The highest number of meta-signature miRNAs was involved in the sphingolipid signaling pathway. Natural killer cell-mediated cytotoxicity was the pathway with most genes regulated by identified miRNAs. The rest of the enriched pathways in our miRNA list describe different malignancies and signaling. The identified miRNA meta-signature might be considered as a potential battery of biomarkers when distinguishing oral cancer tissue from normal, non-cancerous tissue. Further mechanistic studies are warranted in order to confirm and fully elucidate the role of deregulated miRNAs in oral cancer.

The Wnt/β-catenin pathway is deregulated in cemento-ossifying fibromas.

PubMed

Pereira, Thaís Dos Santos Fontes; Diniz, Marina Gonçalves; França, Josiane Alves; Moreira, Rennan Garcias; Menezes, Grazielle Helena Ferreira de; Sousa, Sílvia Ferreira de; Castro, Wagner Henriques de; Gomes, Carolina Cavaliéri; Gomez, Ricardo Santiago

2018-02-01

The molecular pathogenesis of cemento ossifying fibroma (COF) is unclear. The purpose of this study was to investigate mutations in 50 oncogenes and tumor suppressor genes, including APC and CTNNB1, in which mutations in COF have been previously reported. In addition, we assessed the transcriptional levels of the Wnt/β-catenin pathway genes in COF. We used a quantitative polymerase chain reaction array to evaluate the transcriptional levels of 44 Wnt/β-catenin pathway genes in 6 COF samples, in comparison with 6 samples of healthy jaws. By using next-generation sequencing (NGS) in 7 COF samples, we investigated approximately 2800 mutations in 50 genes. The expression assay revealed 12 differentially expressed Wnt/β-catenin pathway genes in COF, including the upregulation of CTNNB1, TCF7, NKD1, and WNT5 A, and downregulation of CTNNBIP1, FRZB, FZD6, RHOU, SFRP4, WNT10 A, WNT3 A, and WNT4, suggesting activation of the Wnt/β-catenin signaling pathway. NGS revealed 5 single nucleotide variants: TP53 (rs1042522), PIK3 CA (rs2230461), MET (rs33917957), KIT (rs3822214), and APC (rs33974176), but none of them was pathogenic. Although NGS detected no oncogenic mutation, deregulation of key Wnt/β-catenin signaling pathway genes appears to be relevant to the molecular pathogenesis of COF. Copyright © 2017 Elsevier Inc. All rights reserved.

Modification of the plasma complement protein profile by exogenous estrogens is indicative of a compromised immune competence in marine medaka (Oryzias melastigma).

PubMed

Dong, Miao; Seemann, Frauke; Humble, Joseph L; Liang, Yimin; Peterson, Drew R; Ye, Rui; Ren, Honglin; Kim, Hui-Su; Lee, Jae-Seong; Au, Doris W T; Lam, Yun Wah

2017-11-01

Growing evidence suggests that the immune system of teleost is vulnerable to xenoestrogens, which are ubiquitous in the marine environment. This study detected and identified the major circulatory immune proteins deregulated by 17α-ethinylestradiol (EE2), which may be linked to fish susceptibility to pathogens in the marine medaka, Oryzias melastigma. Fish immune competence was determined using a host resistance assay to pathogenic bacteria Edwardsiella tarda. Females were consistently more susceptible to infection-induced mortality than males. Exposure to EE2 could narrow the sex gap of mortality by increasing infection-induced death in male fish. Proteomic analysis revealed that the major plasma immune proteins of adult fish were highly sexually dimorphic. EE2 induced pronounced sex-specific changes in the plasma proteome, with the male plasma composition clearly becoming "feminised". Male plasma was found to contain a higher level of fibrinogens, WAP63 and ependymin-2-like protein, which are involved in coagulation, inflammation and regeneration. For the first time, we demonstrated that expression of C1q subunit B (C1Q), an initiating factor of the classical complement pathway, was higher in males and was suppressed in both sexes in response to EE2 and bacterial challenge. Moreover, cleavage and post-translational modification of C3, the central component of the complement system, could be altered by EE2 treatment in males (C3dg down; C3g up). Multiple regression analysis indicated that C1Q is possibly an indicator of fish survival, which warrants further confirmation. The findings support the potential application of plasma immune proteins for prognosis/diagnosis of fish immune competence. Moreover, this study provides the first biochemical basis of the sex-differences in fish immunity and how these differences might be modified by xenoestrogens. Copyright © 2017 Elsevier Ltd. All rights reserved.

Targeting deregulated AMPK/mTORC1 pathways improves muscle function in myotonic dystrophy type I.

PubMed

Brockhoff, Marielle; Rion, Nathalie; Chojnowska, Kathrin; Wiktorowicz, Tatiana; Eickhorst, Christopher; Erne, Beat; Frank, Stephan; Angelini, Corrado; Furling, Denis; Rüegg, Markus A; Sinnreich, Michael; Castets, Perrine

2017-02-01

Myotonic dystrophy type I (DM1) is a disabling multisystemic disease that predominantly affects skeletal muscle. It is caused by expanded CTG repeats in the 3'-UTR of the dystrophia myotonica protein kinase (DMPK) gene. RNA hairpins formed by elongated DMPK transcripts sequester RNA-binding proteins, leading to mis-splicing of numerous pre-mRNAs. Here, we have investigated whether DM1-associated muscle pathology is related to deregulation of central metabolic pathways, which may identify potential therapeutic targets for the disease. In a well-characterized mouse model for DM1 (HSALR mice), activation of AMPK signaling in muscle was impaired under starved conditions, while mTORC1 signaling remained active. In parallel, autophagic flux was perturbed in HSALR muscle and in cultured human DM1 myotubes. Pharmacological approaches targeting AMPK/mTORC1 signaling greatly ameliorated muscle function in HSALR mice. AICAR, an AMPK activator, led to a strong reduction of myotonia, which was accompanied by partial correction of misregulated alternative splicing. Rapamycin, an mTORC1 inhibitor, improved muscle relaxation and increased muscle force in HSALR mice without affecting splicing. These findings highlight the involvement of AMPK/mTORC1 deregulation in DM1 muscle pathophysiology and may open potential avenues for the treatment of this disease.

Exposure to Endocrine Disruptor Induces Transgenerational Epigenetic Deregulation of MicroRNAs in Primordial Germ Cells

PubMed Central

Brieño-Enríquez, Miguel A.; García-López, Jesús; Cárdenas, David B.; Guibert, Sylvain; Cleroux, Elouan; Děd, Lukas; Hourcade, Juan de Dios; Pěknicová, Jana; Weber, Michael; del Mazo, Jesús

2015-01-01

In mammals, germ cell differentiation is initiated in the Primordial Germ Cells (PGCs) during fetal development. Prenatal exposure to environmental toxicants such as endocrine disruptors may alter PGC differentiation, development of the male germline and induce transgenerational epigenetic disorders. The anti-androgenic compound vinclozolin represents a paradigmatic example of molecule causing transgenerational effects on germ cells. We performed prenatal exposure to vinclozolin in mice and analyzed the phenotypic and molecular changes in three successive generations. A reduction in the number of embryonic PGCs and increased rate of apoptotic cells along with decrease of fertility rate in adult males were observed in F1 to F3 generations. Blimp1 is a crucial regulator of PGC differentiation. We show that prenatal exposure to vinclozolin deregulates specific microRNAs in PGCs, such as miR-23b and miR-21, inducing disequilibrium in the Lin28/let-7/Blimp1 pathway in three successive generations of males. As determined by global maps of cytosine methylation, we found no evidence for prominent changes in DNA methylation in PGCs or mature sperm. Our data suggest that embryonic exposure to environmental endocrine disruptors induces transgenerational epigenetic deregulation of expression of microRNAs affecting key regulatory pathways of germ cells differentiation. PMID:25897752

Targeting deregulated AMPK/mTORC1 pathways improves muscle function in myotonic dystrophy type I

PubMed Central

Brockhoff, Marielle; Rion, Nathalie; Chojnowska, Kathrin; Wiktorowicz, Tatiana; Eickhorst, Christopher; Erne, Beat; Frank, Stephan; Angelini, Corrado; Rüegg, Markus A.; Sinnreich, Michael

2017-01-01

Myotonic dystrophy type I (DM1) is a disabling multisystemic disease that predominantly affects skeletal muscle. It is caused by expanded CTG repeats in the 3′-UTR of the dystrophia myotonica protein kinase (DMPK) gene. RNA hairpins formed by elongated DMPK transcripts sequester RNA-binding proteins, leading to mis-splicing of numerous pre-mRNAs. Here, we have investigated whether DM1-associated muscle pathology is related to deregulation of central metabolic pathways, which may identify potential therapeutic targets for the disease. In a well-characterized mouse model for DM1 (HSALR mice), activation of AMPK signaling in muscle was impaired under starved conditions, while mTORC1 signaling remained active. In parallel, autophagic flux was perturbed in HSALR muscle and in cultured human DM1 myotubes. Pharmacological approaches targeting AMPK/mTORC1 signaling greatly ameliorated muscle function in HSALR mice. AICAR, an AMPK activator, led to a strong reduction of myotonia, which was accompanied by partial correction of misregulated alternative splicing. Rapamycin, an mTORC1 inhibitor, improved muscle relaxation and increased muscle force in HSALR mice without affecting splicing. These findings highlight the involvement of AMPK/mTORC1 deregulation in DM1 muscle pathophysiology and may open potential avenues for the treatment of this disease. PMID:28067669

Proteomic Identification of the Galectin-1-Involved Molecular Pathways in Urinary Bladder Urothelial Carcinoma.

PubMed

Li, Chien-Feng; Shen, Kun-Hung; Chien, Lan-Hsiang; Huang, Cheng-Hao; Wu, Ting-Feng; He, Hong-Lin

2018-04-19

Among various heterogeneous types of bladder tumors, urothelial carcinoma is the most prevalent lesion. Some of the urinary bladder urothelial carcinomas (UBUCs) develop local recurrence and may cause distal invasion. Galectin-1 de-regulation significantly affects cell transformation, cell proliferation, angiogenesis, and cell invasiveness. In continuation of our previous investigation on the role of galectin-1 in UBUC tumorigenesis, in this study, proteomics strategies were implemented in order to find more galectin-1-associated signaling pathways. The results of this study showed that galectin-1 knockdown could induce 15 down-regulated proteins and two up-regulated proteins in T24 cells. These de-regulated proteins might participate in lipid/amino acid/energy metabolism, cytoskeleton, cell proliferation, cell-cell interaction, cell apoptosis, metastasis, and protein degradation. The aforementioned dys-regulated proteins were confirmed by western immunoblotting. Proteomics results were further translated to prognostic markers by analyses of biopsy samples. Results of cohort studies demonstrated that over-expressions of glutamine synthetase, alcohol dehydrogenase (NADP⁺), fatty acid binding protein 4, and toll interacting protein in clinical specimens were all significantly associated with galectin-1 up-regulation. Univariate analyses showed that de-regulations of glutamine synthetase and fatty acid binding protein 4 in clinical samples were respectively linked to disease-specific survival and metastasis-free survival.

Identification of NVP-BKM120 as a Potent, Selective, Orally Bioavailable Class I PI3 Kinase Inhibitor for Treating Cancer.

PubMed

Burger, Matthew T; Pecchi, Sabina; Wagman, Allan; Ni, Zhi-Jie; Knapp, Mark; Hendrickson, Thomas; Atallah, Gordana; Pfister, Keith; Zhang, Yanchen; Bartulis, Sarah; Frazier, Kelly; Ng, Simon; Smith, Aaron; Verhagen, Joelle; Haznedar, Joshua; Huh, Kay; Iwanowicz, Ed; Xin, Xiaohua; Menezes, Daniel; Merritt, Hanne; Lee, Isabelle; Wiesmann, Marion; Kaufman, Susan; Crawford, Kenneth; Chin, Michael; Bussiere, Dirksen; Shoemaker, Kevin; Zaror, Isabel; Maira, Sauveur-Michel; Voliva, Charles F

2011-10-13

Phosphoinositide-3-kinases (PI3Ks) are important oncology targets due to the deregulation of this signaling pathway in a wide variety of human cancers. Herein we describe the structure guided optimization of a series of 2-morpholino, 4-substituted, 6-heterocyclic pyrimidines where the pharmacokinetic properties were improved by modulating the electronics of the 6-position heterocycle, and the overall druglike properties were fine-tuned further by modification of the 4-position substituent. The resulting 2,4-bismorpholino 6-heterocyclic pyrimidines are potent class I PI3K inhibitors showing mechanism modulation in PI3K dependent cell lines and in vivo efficacy in tumor xenograft models with PI3K pathway deregulation (A2780 ovarian and U87MG glioma). These efforts culminated in the discovery of 15 (NVP-BKM120), currently in Phase II clinical trials for the treatment of cancer.

Identification of NVP-BKM120 as a Potent, Selective, Orally Bioavailable Class I PI3 Kinase Inhibitor for Treating Cancer

PubMed Central

2011-01-01

Phosphoinositide-3-kinases (PI3Ks) are important oncology targets due to the deregulation of this signaling pathway in a wide variety of human cancers. Herein we describe the structure guided optimization of a series of 2-morpholino, 4-substituted, 6-heterocyclic pyrimidines where the pharmacokinetic properties were improved by modulating the electronics of the 6-position heterocycle, and the overall druglike properties were fine-tuned further by modification of the 4-position substituent. The resulting 2,4-bismorpholino 6-heterocyclic pyrimidines are potent class I PI3K inhibitors showing mechanism modulation in PI3K dependent cell lines and in vivo efficacy in tumor xenograft models with PI3K pathway deregulation (A2780 ovarian and U87MG glioma). These efforts culminated in the discovery of 15 (NVP-BKM120), currently in Phase II clinical trials for the treatment of cancer. PMID:24900266

Recent advances in understanding the biology of marginal zone lymphoma

PubMed Central

Zucca, Emanuele

2018-01-01

There are three different marginal zone lymphomas (MZLs): the extranodal MZL of mucosa-associated lymphoid tissue (MALT) type (MALT lymphoma), the splenic MZL, and the nodal MZL. The three MZLs share common lesions and deregulated pathways but also present specific alterations that can be used for their differential diagnosis. Although trisomies of chromosomes 3 and 18, deletions at 6q23, deregulation of nuclear factor kappa B, and chromatin remodeling genes are frequent events in all of them, the three MZLs differ in the presence of recurrent translocations, mutations affecting the NOTCH pathway, and the transcription factor Kruppel like factor 2 ( KLF2) or the receptor-type protein tyrosine phosphatase delta ( PTPRD). Since a better understanding of the molecular events underlying each subtype may have practical relevance, this review summarizes the most recent and main advances in our understanding of the genetics and biology of MZLs. PMID:29657712

WDR26 in Advanced Breast Cancer: A Novel Regulator of the P13K/AKT Pathway

DTIC Science & Technology

2017-10-01

AWARD NUMBER: W81XWH-14-1-0539 TITLE: WDR26 in Advanced Breast Cancer : A Novel Regulator of the P13K/ AKT Pathway PRINCIPAL INVESTIGATOR...SUBTITLE 5a. CONTRACT NUMBER WDR26 in Advanced Breast Cancer : A Novel Regulator of the P13K/AKT Pathway 5b. GRANT NUMBER W81XWH-14-1-0539 5c. PROGRAM...NOTES 14. ABSTRACT The PI3K/AKT pathway is one of the most deregulated pathways in breast cancers (>70%), and a major contributor to tumor progression

Differential mechanisms of complement-mediated neutralization of the closely related paramyxoviruses simian virus 5 and mumps virus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, John B.; Capraro, Gerald A.; Parks, Griffith D.

2008-06-20

The complement system is an important component of the innate immune response to virus infection. The role of human complement pathways in the in vitro neutralization of three closely related paramyxoviruses, Simian Virus 5 (SV5), Mumps virus (MuV) and Human Parainfluenza virus type 2 (HPIV2) was investigated. Sera from ten donors showed high levels of neutralization against HPIV2 that was largely complement-independent, whereas nine of ten donor sera were found to neutralize SV5 and MuV only in the presence of active complement pathways. SV5 and MuV neutralization proceeded through the alternative pathway of the complement cascade. Electron microscopy studies andmore » biochemical analyses showed that treatment of purified SV5 with human serum resulted in C3 deposition on virions and the formation of massive aggregates, but there was relatively little evidence of virion lysis. Treatment of MuV with human serum also resulted in C3 deposition on virions, however in contrast to SV5, MuV particles were lysed by serum complement and there was relatively little aggregation. Assays using serum depleted of complement factors showed that SV5 and MuV neutralization in vitro was absolutely dependent on complement factor C3, but was not dependent on downstream complement factors C5 or C8. Our results indicate that even though antibodies exist that recognize both SV5 and MuV, they are mostly non-neutralizing and viral inactivation in vitro occurs through the alternative pathway of complement. The implications of our work for development of paramyxovirus vectors and vaccines are discussed.« less

Tuning complement activation and pathway through controlled molecular architecture of dextran chains in nanoparticle corona.

PubMed

Coty, Jean-Baptiste; Eleamen Oliveira, Elquio; Vauthier, Christine

2017-11-05

The understanding of complement activation by nanomaterials is a key to a rational design of safe and efficient nanomedicines. This work proposed a systematic study investigating how molecular design of nanoparticle coronas made of dextran impacts on mechanisms that trigger complement activation. The nanoparticles used for this work consisted of dextran-coated poly(isobutylcyanoacrylate) (PIBCA) nanoparticles have already been thoroughly characterized. Their different capacity to trigger complement activation established on the cleavage of the protein C3 was also already described making these nanoparticles good models to investigate the relation between the molecular feature of their corona and the mechanism by which they triggered complement activation. Results of this new study show that complement activation pathways can be selected by distinct architectures formed by dextran chains composing the nanoparticle corona. Assumptions that explain the relation between complement activation mechanisms triggered by the nanoparticles and the nanoparticle corona molecular feature were proposed. These results are of interest to better understand how the design of dextran-coated nanomaterials will impact interactions with the complement system. It can open perspectives with regard to the selection of a preferential complement activation pathway or prevent the nanoparticles to activate the complement system, based on a rational choice of the corona configuration. Copyright © 2017 Elsevier B.V. All rights reserved.

An amphioxus gC1q protein binds human IgG and initiates the classical pathway: Implications for a C1q-mediated complement system in the basal chordate.

PubMed

Gao, Zhan; Li, Mengyang; Ma, Jie; Zhang, Shicui

2014-12-01

The origin of the classical complement pathway remains open during chordate evolution. A C1q-like member, BjC1q, was identified in the basal chordate amphioxus. It is predominantly expressed in the hepatic caecum, hindgut, and notochord, and is significantly upregulated following challenge with bacteria or lipoteichoic acid and LPS. Recombinant BjC1q and its globular head domain specifically interact with lipoteichoic acid and LPS, but BjC1q displays little lectin activity. Moreover, rBjC1q can assemble to form the high molecular weight oligomers necessary for binding to proteases C1r/C1s and for complement activation, and binds human C1r/C1s/mannan-binding lectin-associated serine protease-2 as well as amphioxus serine proteases involved in the cleavage of C4/C2, and C3 activation. Importantly, rBjC1q binds with human IgG as well as an amphioxus Ig domain containing protein, resulting in the activation of the classical complement pathway. This is the first report showing that a C1q-like protein in invertebrates is able to initiate classical pathway, raising the possibility that amphioxus possesses a C1q-mediated complement system. It also suggests a new scenario for the emergence of the classical complement pathway, in contrast to the proposal that the lectin pathway evolved into the classical pathway. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Activation of the lectin pathway of complement in experimental human keratitis with Pseudomonas aeruginosa.

PubMed

Osthoff, Michael; Brown, Karl D; Kong, David C M; Daniell, Mark; Eisen, Damon P

2014-01-01

Pseudomonas aeruginosa (P. aeruginosa) microbial keratitis (MK) is a sight-threatening disease. Previous animal studies have identified an important contribution of the complement system to the clearance of P. aeruginosa infection of the cornea. Mannose-binding lectin (MBL), a pattern recognition receptor of the lectin pathway of complement, has been implicated in the host defense against P. aeruginosa. However, studies addressing the role of the lectin pathway in P. aeruginosa MK are lacking. Hence, we sought to determine the activity of the lectin pathway in human MK caused by P. aeruginosa. Primary human corneal epithelial cells (HCECs) from cadaveric donors were exposed to two different P. aeruginosa strains. Gene expression of interleukin (IL)-6, IL-8, MBL, and other complement proteins was determined by reverse transcription-polymerase chain reaction (RT-PCR) and MBL synthesis by enzyme-linked immunosorbent assay and intracellular flow cytometry. MBL gene expression was not detected in unchallenged HCECs. Exposure of HCECs to P. aeruginosa resulted in rapid induction of the transcriptional expression of MBL, IL-6, and IL-8. In addition, expression of several complement proteins of the classical and lectin pathways, but not the alternative pathway, were upregulated after 5 h of challenge, including MBL-associated serine protease 1. However, MBL protein secretion was not detectable 18 h after challenge with P. aeruginosa. MK due to P. aeruginosa triggers activation of MBL and the lectin pathway of complement. However, the physiologic relevance of this finding is unclear, as corresponding MBL oligomer production was not observed.

Activation of the lectin pathway of complement in experimental human keratitis with Pseudomonas aeruginosa

PubMed Central

Osthoff, Michael; Brown, Karl D.; Kong, David C.M.; Daniell, Mark

2014-01-01

Purpose Pseudomonas aeruginosa (P. aeruginosa) microbial keratitis (MK) is a sight-threatening disease. Previous animal studies have identified an important contribution of the complement system to the clearance of P. aeruginosa infection of the cornea. Mannose-binding lectin (MBL), a pattern recognition receptor of the lectin pathway of complement, has been implicated in the host defense against P. aeruginosa. However, studies addressing the role of the lectin pathway in P. aeruginosa MK are lacking. Hence, we sought to determine the activity of the lectin pathway in human MK caused by P. aeruginosa. Methods Primary human corneal epithelial cells (HCECs) from cadaveric donors were exposed to two different P. aeruginosa strains. Gene expression of interleukin (IL)-6, IL-8, MBL, and other complement proteins was determined by reverse transcription-polymerase chain reaction (RT–PCR) and MBL synthesis by enzyme-linked immunosorbent assay and intracellular flow cytometry. Results MBL gene expression was not detected in unchallenged HCECs. Exposure of HCECs to P. aeruginosa resulted in rapid induction of the transcriptional expression of MBL, IL-6, and IL-8. In addition, expression of several complement proteins of the classical and lectin pathways, but not the alternative pathway, were upregulated after 5 h of challenge, including MBL-associated serine protease 1. However, MBL protein secretion was not detectable 18 h after challenge with P. aeruginosa. Conclusions MK due to P. aeruginosa triggers activation of MBL and the lectin pathway of complement. However, the physiologic relevance of this finding is unclear, as corresponding MBL oligomer production was not observed. PMID:24426774

Neutrophil extracellular traps can activate alternative complement pathways.

PubMed

Wang, H; Wang, C; Zhao, M-H; Chen, M

2015-09-01

The interaction between neutrophils and activation of alternative complement pathway plays a pivotal role in the pathogenesis of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). ANCAs activate primed neutrophils to release neutrophil extracellular traps (NETs), which have recently gathered increasing attention in the development of AAV. The relationship between NETs and alternative complement pathway has not been elucidated. The current study aimed to investigate the relationship between NETs and alternative complement pathway. Detection of components of alternative complement pathway on NETs in vitro was assessed by immunostain and confocal microscopy. Complement deposition on NETs were detected after incubation with magnesium salt ethyleneglycol tetraacetic acid (Mg-EGTA)-treated human serum. After incubation of serum with supernatants enriched in ANCA-induced NETs, levels of complement components in supernatants were measured by enzyme-linked immunosorbent assay (ELISA). Complement factor B (Bb) and properdin deposited on NETs in vitro. The deposition of C3b and C5b-9 on NETs incubated with heat-inactivated normal human serum (Hi-NHS) or EGTA-treated Hi-NHS (Mg-EGTA-Hi-NHS) were significantly less than that on NETs incubated with NHS or EGTA-treated NHS (Mg-EGTA-NHS). NETs induced by ANCA could activate the alternative complement cascade in the serum. In the presence of EGTA, C3a, C5a and SC5b-9 concentration decreased from 800·42 ± 244·81 ng/ml, 7·68 ± 1·50 ng/ml, 382·15 ± 159·75 ng/ml in the supernatants enriched in ANCA induced NETs to 479·07 ± 156·2 ng/ml, 4·86 ± 1·26 ng/ml, 212·65 ± 44·40 ng/ml in the supernatants of DNase I-degraded NETs (P < 0·001, P = 0·008, P < 0·001, respectively). NETs could activate the alternative complement pathway, and might thus participate in the pathogenesis of AAV. © 2015 British Society for Immunology.

Protein kinase inhibitors against malignant lymphoma

PubMed Central

D’Cruz, Osmond J; Uckun, Fatih M

2013-01-01

Introduction Tyrosine kinases (TKs) are intimately involved in multiple signal transduction pathways regulating survival, activation, proliferation and differentiation of lymphoid cells. Deregulation or overexpression of specific oncogenic TKs is implicated in maintaining the malignant phenotype in B-lineage lymphoid malignancies. Several novel targeted TK inhibitors (TKIs) have recently emerged as active in the treatment of relapsed or refractory B-cell lymphomas that inhibit critical signaling pathways, promote apoptotic mechanisms or modulate the tumor microenvironment. Areas covered In this review, the authors summarize the clinical outcomes of newer TKIs in various B-cell lymphomas from published and ongoing clinical studies and abstracts from major cancer and hematology conferences. Expert opinion Multiple clinical trials have demonstrated that robust antitumor activity can be obtained with TKIs directed toward specific oncogenic TKs that are genetically deregulated in various subtypes of B-cell lymphomas. Clinical success of targeting TKIs is dependent upon on identifying reliable molecular and clinical markers associated with select cohorts of patients. Further understanding of the signaling pathways should stimulate the identification of novel molecular targets and expand the development of new therapeutic options and individualized therapies. PMID:23496343

Therapeutic Interventions to Disrupt the Protein Synthetic Machinery in Melanoma

PubMed Central

Kardos, Gregory R.; Robertson, Gavin P.

2015-01-01

Control of the protein synthetic machinery is deregulated in many cancers, including melanoma, in order to increase protein production. Tumor suppressors and oncogenes play key roles in protein synthesis from the transcription of rRNA and ribosome biogenesis to mRNA translation initiation and protein synthesis. Major signaling pathways are altered in melanoma to modulate the protein synthetic machinery thereby promoting tumor development. However, despite the importance of this process in melanoma development, involvement of the protein synthetic machinery in this cancer type is an underdeveloped area of study. Here, we review the coupling of melanoma development to deregulation of the protein synthetic machinery. We examine existing knowledge regarding RNA Polymerase I inhibition and mRNA translation focusing on their inhibition for therapeutic applications in melanoma. Furthermore, the contribution of amino acid biosynthesis and involvement of ribosomal proteins are also reviewed as future therapeutic strategies to target deregulated protein production in melanoma. PMID:26139519

Alternative pathway regulation by factor H modulates Streptococcus pneumoniae induced proinflammatory cytokine responses by decreasing C5a receptor crosstalk.

PubMed

van der Maten, Erika; de Bont, Cynthia M; de Groot, Ronald; de Jonge, Marien I; Langereis, Jeroen D; van der Flier, Michiel

2016-12-01

Bacterial pathogens not only stimulate innate immune receptors, but also activate the complement system. Crosstalk between complement C5a receptor (C5aR) and other innate immune receptors is known to enhance the proinflammatory cytokine response. An important determinant of the magnitude of complement activation is the activity of the alternative pathway, which serves as an amplification mechanism for complement activation. Both alternative pathway activity as well as plasma levels of factor H, a key inhibitor of the alternative pathway, show large variation within the human population. Here, we studied the effect of factor H-mediated regulation of the alternative pathway on bacterial-induced proinflammatory cytokine responses. We used the human pathogen Streptococcus pneumoniae as a model stimulus to induce proinflammatory cytokine responses in human peripheral blood mononuclear cells. Serum containing active complement enhanced pneumococcal induced proinflammatory cytokine production through C5a release and C5aR crosstalk. We found that inhibition of the alternative pathway by factor H, with a concentration equivalent to a high physiological level, strongly reduced C5a levels and decreased proinflammatory cytokine production in human peripheral blood mononuclear cells. This suggests that variation in alternative pathway activity due to variation in factor H plasma levels affects individual cytokine responses during infection. Copyright © 2016 Elsevier Ltd. All rights reserved.

Alternative complement pathway activation increases mortality in a model of burn injury in mice.

PubMed Central

Gelfand, J A; Donelan, M; Hawiger, A; Burke, J F

1982-01-01

We have studied the role of the complement system in burn injury in an experimental model in mice. A 25% body surface area, full-thickness scald wound was produced in anesthetized animals. Massive activation of the alternative complement pathway, but not the classical pathway, was seen. This activation was associated with the generation of neutrophil aggregating activity in the plasma, neutrophil aggregates in the lungs, increased pulmonary vascular permeability, and increased lung edema formation. Decomplementation with cobra venom factor (CVF) or genetic C5 deficiency diminished these pathologic changes, and CVF pretreatment substantially reduced burn mortality in the first 24 h. Preliminary data show that human burn patients have a similar pattern of complement activation involving predominantly the alternative pathway, indicating the possible relevance of the murine model to human disease. Images PMID:7174787

Two decades of leukemia oncoprotein epistasis: the MLL1 paradigm for epigenetic deregulation in leukemia

PubMed Central

Li, Bin E.; Ernst, Patricia

2015-01-01

MLL1, located on human chromosome 11, is disrupted in distinct recurrent chromosomal translocations in several leukemia subsets. Studying the MLL1 gene and its oncogenic variants has provided a paradigm for understanding cancer initiation and maintenance through aberrant epigenetic gene regulation. Here we review the historical development of model systems to recapitulate oncogenic MLL1-rearrangement (MLL-r) alleles encoding mixed-lineage leukemia fusion proteins (MLL-FPs) or internal gene rearrangement products. These largely mouse and human cell/xenograft systems have been generated and used to understand how MLL-r alleles affect diverse pathways to result in a highly penetrant, drug-resistant leukemia. The particular features of the animal models influenced the conclusions of mechanisms of transformation. We discuss significant downstream enablers, inhibitors, effectors, and collaborators of MLL-r leukemia, including molecules that directly interact with MLL-FPs and endogenous mixed-lineage leukemia protein, direct target genes of MLL-FPs, and other pathways that have proven to be influential in supporting or suppressing the leukemogenic activity of MLL-FPs. The use of animal models has been complemented with patient sample, genome-wide analyses to delineate the important genomic and epigenomic changes that occur in distinct subsets of MLL-r leukemia. Collectively, these studies have resulted in rapid progress toward developing new strategies for targeting MLL-r leukemia and general cell-biological principles that may broadly inform targeting aberrant epigenetic regulators in other cancers. PMID:25264566

Involvement of aryl hydrocarbon receptor signaling in the development of small cell lung cancer induced by HPV E6/E7 oncoproteins

PubMed Central

2011-01-01

Background Lung cancers consist of four major types that and for clinical-pathological reasons are often divided into two broad categories: small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). All major histological types of lung cancer are associated with smoking, although the association is stronger for SCLC and squamous cell carcinoma than adenocarcinoma. To date, epidemiological studies have identified several environmental, genetic, hormonal and viral factors associated with lung cancer risk. It has been estimated that 15-25% of human cancers may have a viral etiology. The human papillomavirus (HPV) is a proven cause of most human cervical cancers, and might have a role in other malignancies including vulva, skin, oesophagus, head and neck cancer. HPV has also been speculated to have a role in the pathogenesis of lung cancer. To validate the hypothesis of HPV involvement in small cell lung cancer pathogenesis we performed a gene expression profile of transgenic mouse model of SCLC induced by HPV-16 E6/E7 oncoproteins. Methods Gene expression profile of SCLC has been performed using Agilent whole mouse genome (4 × 44k) representing ~ 41000 genes and mouse transcripts. Samples were obtained from two HPV16-E6/E7 transgenic mouse models and from littermate's normal lung. Data analyses were performed using GeneSpring 10 and the functional classification of deregulated genes was performed using Ingenuity Pathway Analysis (Ingenuity® Systems, http://www.ingenuity.com). Results Analysis of deregulated genes induced by the expression of E6/E7 oncoproteins supports the hypothesis of a linkage between HPV infection and SCLC development. As a matter of fact, comparison of deregulated genes in our system and those in human SCLC showed that many of them are located in the Aryl Hydrocarbon Receptor Signal transduction pathway. Conclusions In this study, the global gene expression of transgenic mouse model of SCLC induced by HPV-16 E6/E7 oncoproteins led us to identification of several genes involved in SCLC tumor development. Furthermore, our study reveled that the Aryl Hydrocarbon Receptor Signaling is the primarily affected pathway by the E6/E7 oncoproteins expression and that this pathway is also deregulated in human SCLC. Our results provide the basis for the development of new therapeutic approaches against human SCLC. PMID:21205295

A randomized, first-in-human, healthy volunteer trial of BIVV009, a humanized antibody for the specific inhibition of the classical complement pathway.

PubMed

Bartko, Johann; Schoergenhofer, Christian; Schwameis, Michael; Firbas, Christa; Beliveau, Martin; Chang, Colin; Marier, Jean-Francois; Nix, Darrell; Gilbert, James C; Panicker, Sandip; Jilma, Bernd

2018-05-08

Aberrant activation of the classical complement pathway is the common underlying pathophysiology of orphan diseases such as bullous pemphigoid, antibody-mediated rejection of organ transplants, cold agglutinin disease and warm autoimmune haemolytic anaemia. Therapeutic options for these complement-mediated disorders are limited and BIVV009, a humanized monoclonal antibody directed against complement factor C1s, may be potentially useful for inhibition of the classical complement pathway. A phase-1, first-in-human, double-blind, randomized, placebo-controlled, dose-escalation trial of single and multiple doses of BIVV009 or placebo was conducted in 64 volunteers to evaluate safety, tolerability, pharmacokinetic, and pharmacodynamic profiles. Single and multiple infusions of BIVV009 were well tolerated without any safety concerns. BIVV009 exhibited a steep concentration-effect relationship with a Hill coefficient of 2.4, and an IC90 of 15.5 µg/mL. This study establishes the foundation for using BIVV009 as a highly selective inhibitor of the classical complement pathway in different diseases. This article is protected by copyright. All rights reserved. © 2018 American Society for Clinical Pharmacology and Therapeutics.

The Group B Streptococcus-Secreted Protein CIP Interacts with C4, Preventing C3b Deposition via the Lectin and Classical Complement Pathways.

PubMed

Pietrocola, Giampiero; Rindi, Simonetta; Rosini, Roberto; Buccato, Scilla; Speziale, Pietro; Margarit, Immaculada

2016-01-01

The group B Streptococcus (GBS) is a leading cause of neonatal invasive disease. GBS bacteria are surrounded by a thick capsular polysaccharide that is a potent inhibitor of complement deposition via the alternative pathway. Several of its surface molecules can however activate the classical and lectin complement pathways, rendering this species still vulnerable to phagocytic killing. In this study we have identified a novel secreted protein named complement interfering protein (CIP) that downregulates complement activation via the classical and lectin pathways, but not the alternative pathway. The CIP protein showed high affinity toward C4b and inhibited its interaction with C2, presumably preventing the formation of the C4bC2a convertase. Addition of recombinant CIP to GBS cip-negative bacteria resulted in decreased deposition of C3b on their surface and in diminished phagocytic killing in a whole-blood assay. Our data reveal a novel strategy exploited by GBS to counteract innate immunity and could be valuable for the development of anti-infective agents against this important pathogen. Copyright © 2015 by The American Association of Immunologists, Inc.

21 CFR 866.5320 - Properdin factor B immuno-logical test system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... involvement of the alternative to the classical pathway of activation of complement (a group of plasma... the skin). Other diseases in which the alternate pathway of complement activation has been implicated...

21 CFR 866.5320 - Properdin factor B immuno-logical test system.

Code of Federal Regulations, 2014 CFR

2014-04-01

... involvement of the alternative to the classical pathway of activation of complement (a group of plasma... the skin). Other diseases in which the alternate pathway of complement activation has been implicated...

21 CFR 866.5320 - Properdin factor B immuno-logical test system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... involvement of the alternative to the classical pathway of activation of complement (a group of plasma... the skin). Other diseases in which the alternate pathway of complement activation has been implicated...

MiR-34a-3p alters proliferation and apoptosis of meningioma cells in vitro and is directly targeting SMAD4, FRAT1 and BCL2

PubMed Central

Werner, Tamara V.; Hart, Martin; Nickels, Ruth; Kim, Yoo-Jin; Menger, Michael D.; Bohle, Rainer M.; Keller, Andreas; Ludwig, Nicole; Meese, Eckart

2017-01-01

Micro (mi)RNAs are short, noncoding RNAs and deregulation of miRNAs and their targets are implicated in tumor generation and progression in many cancers. Meningiomas are mostly benign, slow growing tumors of the central nervous system with a small percentage showing a malignant phenotype. Following in silico prediction of potential targets of miR-34a-3p, SMAD4, FRAT1, and BCL2 have been confirmed as targets by dual luciferase assays with co-expression of miR-34a-3p and reporter gene constructs containing the respective 3'UTRs. Disruption of the miR-34a-3p binding sites in the 3'UTRs resulted in loss of responsiveness to miR-34a-3p overexpression. In meningioma cells, overexpression of miR-34a-3p resulted in decreased protein levels of SMAD4, FRAT1 and BCL2, while inhibition of miR-34a-3p led to increased levels of these proteins as confirmed by Western blotting. Furthermore, deregulation of miR-34a-3p altered cell proliferation and apoptosis of meningioma cells in vitro. We show that SMAD4, FRAT1 and BCL2 are direct targets of miR-34a-3p and that deregulation of miR-34a-3p alters proliferation and apoptosis of meningioma cells in vitro. As part of their respective signaling pathways, which are known to play a role in meningioma genesis and progression, deregulation of SMAD4, FRAT1 and BCL2 might contribute to the aberrant activation of these signaling pathways leading to increased proliferation and inhibition of apoptosis in meningiomas. PMID:28340489

MiR-34a-3p alters proliferation and apoptosis of meningioma cells in vitro and is directly targeting SMAD4, FRAT1 and BCL2.

PubMed

Werner, Tamara V; Hart, Martin; Nickels, Ruth; Kim, Yoo-Jin; Menger, Michael D; Bohle, Rainer M; Keller, Andreas; Ludwig, Nicole; Meese, Eckart

2017-03-23

Micro (mi)RNAs are short, noncoding RNAs and deregulation of miRNAs and their targets are implicated in tumor generation and progression in many cancers. Meningiomas are mostly benign, slow growing tumors of the central nervous system with a small percentage showing a malignant phenotype.Following in silico prediction of potential targets of miR-34a-3p, SMAD4 , FRAT1 , and BCL2 have been confirmed as targets by dual luciferase assays with co-expression of miR-34a-3p and reporter gene constructs containing the respective 3'UTRs. Disruption of the miR-34a-3p binding sites in the 3'UTRs resulted in loss of responsiveness to miR-34a-3p overexpression. In meningioma cells, overexpression of miR-34a-3p resulted in decreased protein levels of SMAD4, FRAT1 and BCL2, while inhibition of miR-34a-3p led to increased levels of these proteins as confirmed by Western blotting. Furthermore, deregulation of miR-34a-3p altered cell proliferation and apoptosis of meningioma cells in vitro .We show that SMAD4 , FRAT1 and BCL2 are direct targets of miR-34a-3p and that deregulation of miR-34a-3p alters proliferation and apoptosis of meningioma cells in vitro . As part of their respective signaling pathways, which are known to play a role in meningioma genesis and progression, deregulation of SMAD4 , FRAT1 and BCL2 might contribute to the aberrant activation of these signaling pathways leading to increased proliferation and inhibition of apoptosis in meningiomas.

Metabolic Complementation in Bacterial Communities: Necessary Conditions and Optimality

PubMed Central

Mori, Matteo; Ponce-de-León, Miguel; Peretó, Juli; Montero, Francisco

2016-01-01

Bacterial communities may display metabolic complementation, in which different members of the association partially contribute to the same biosynthetic pathway. In this way, the end product of the pathway is synthesized by the community as a whole. However, the emergence and the benefits of such complementation are poorly understood. Herein, we present a simple model to analyze the metabolic interactions among bacteria, including the host in the case of endosymbiotic bacteria. The model considers two cell populations, with both cell types encoding for the same linear biosynthetic pathway. We have found that, for metabolic complementation to emerge as an optimal strategy, both product inhibition and large permeabilities are needed. In the light of these results, we then consider the patterns found in the case of tryptophan biosynthesis in the endosymbiont consortium hosted by the aphid Cinara cedri. Using in-silico computed physicochemical properties of metabolites of this and other biosynthetic pathways, we verified that the splitting point of the pathway corresponds to the most permeable intermediate. PMID:27774085

Transposable Element Misregulation Is Linked to the Divergence between Parental piRNA Pathways in Drosophila Hybrids.

PubMed

Romero-Soriano, Valèria; Modolo, Laurent; Lopez-Maestre, Hélène; Mugat, Bruno; Pessia, Eugénie; Chambeyron, Séverine; Vieira, Cristina; Garcia Guerreiro, Maria Pilar

2017-06-01

Interspecific hybridization is a genomic stress condition that leads to the activation of transposable elements (TEs) in both animals and plants. In hybrids between Drosophila buzzatii and Drosophila koepferae, mobilization of at least 28 TEs has been described. However, the molecular mechanisms underlying this TE release remain poorly understood. To give insight on the causes of this TE activation, we performed a TE transcriptomic analysis in ovaries (notorious for playing a major role in TE silencing) of parental species and their F1 and backcrossed (BC) hybrids. We find that 15.2% and 10.6% of the expressed TEs are deregulated in F1 and BC1 ovaries, respectively, with a bias toward overexpression in both cases. Although differences between parental piRNA (Piwi-interacting RNA) populations explain only partially these results, we demonstrate that piRNA pathway proteins have divergent sequences and are differentially expressed between parental species. Thus, a functional divergence of the piRNA pathway between parental species, together with some differences between their piRNA pools, might be at the origin of hybrid instabilities and ultimately cause TE misregulation in ovaries. These analyses were complemented with the study of F1 testes, where TEs tend to be less expressed than in D. buzzatii. This can be explained by an increase in piRNA production, which probably acts as a defence mechanism against TE instability in the male germline. Hence, we describe a differential impact of interspecific hybridization in testes and ovaries, which reveals that TE expression and regulation are sex-biased. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Small-molecule factor D inhibitors selectively block the alternative pathway of complement in paroxysmal nocturnal hemoglobinuria and atypical hemolytic uremic syndrome.

PubMed

Yuan, Xuan; Gavriilaki, Eleni; Thanassi, Jane A; Yang, Guangwei; Baines, Andrea C; Podos, Steven D; Huang, Yongqing; Huang, Mingjun; Brodsky, Robert A

2017-03-01

Paroxysmal nocturnal hemoglobinuria and atypical hemolytic uremic syndrome are diseases of excess activation of the alternative pathway of complement that are treated with eculizumab, a humanized monoclonal antibody against the terminal complement component C5. Eculizumab must be administered intravenously, and moreover some patients with paroxysmal nocturnal hemoglobinuria on eculizumab have symptomatic extravascular hemolysis, indicating an unmet need for additional therapeutic approaches. We report the activity of two novel small-molecule inhibitors of the alternative pathway component Factor D using in vitro correlates of both paroxysmal nocturnal hemoglobinuria and atypical hemolytic uremic syndrome. Both compounds bind human Factor D with high affinity and effectively inhibit its proteolytic activity against purified Factor B in complex with C3b. When tested using the traditional Ham test with cells from paroxysmal nocturnal hemoglobinuria patients, the Factor D inhibitors significantly reduced complement-mediated hemolysis at concentrations as low as 0.01 μM. Additionally the compound ACH-4471 significantly decreased C3 fragment deposition on paroxysmal nocturnal hemoglobinuria erythrocytes, indicating a reduced potential relative to eculizumab for extravascular hemolysis. Using the recently described modified Ham test with serum from patients with atypical hemolytic uremic syndrome, the compounds reduced the alternative pathway-mediated killing of PIGA -null reagent cells, thus establishing their potential utility for this disease of alternative pathway of complement dysregulation and validating the modified Ham test as a system for pre-clinical drug development for atypical hemolytic uremic syndrome. Finally, ACH-4471 blocked alternative pathway activity when administered orally to cynomolgus monkeys. In conclusion, the small-molecule Factor D inhibitors show potential as oral therapeutics for human diseases driven by the alternative pathway of complement, including paroxysmal nocturnal hemoglobinuria and atypical hemolytic uremic syndrome. Copyright© Ferrata Storti Foundation.

Human L-ficolin, a recognition molecule of the lectin activation pathway of complement, activates complement by binding to pneumolysin, the major toxin of Streptococcus pneumoniae.

PubMed

Ali, Youssif M; Kenawy, Hany I; Muhammad, Adnan; Sim, Robert B; Andrew, Peter W; Schwaeble, Wilhelm J

2013-01-01

The complement system is an essential component of the immune response, providing a critical line of defense against different pathogens including S. pneumoniae. Complement is activated via three distinct pathways: the classical (CP), the alternative (AP) and the lectin pathway (LP). The role of Pneumolysin (PLY), a bacterial toxin released by S. pneumoniae, in triggering complement activation has been studied in vitro. Our results demonstrate that in both human and mouse sera complement was activated via the CP, initiated by direct binding of even non-specific IgM and IgG3 to PLY. Absence of CP activity in C1q(-/-) mouse serum completely abolished any C3 deposition. However, C1q depleted human serum strongly opsonized PLY through abundant deposition of C3 activation products, indicating that the LP may have a vital role in activating the human complement system on PLY. We identified that human L-ficolin is the critical LP recognition molecule that drives LP activation on PLY, while all of the murine LP recognition components fail to bind and activate complement on PLY. This work elucidates the detailed interactions between PLY and complement and shows for the first time a specific role of the LP in PLY-mediated complement activation in human serum.

Human L-ficolin, a Recognition Molecule of the Lectin Activation Pathway of Complement, Activates Complement by Binding to Pneumolysin, the Major Toxin of Streptococcus pneumoniae

PubMed Central

Ali, Youssif M.; Kenawy, Hany I.; Muhammad, Adnan; Sim, Robert B.

2013-01-01

The complement system is an essential component of the immune response, providing a critical line of defense against different pathogens including S. pneumoniae. Complement is activated via three distinct pathways: the classical (CP), the alternative (AP) and the lectin pathway (LP). The role of Pneumolysin (PLY), a bacterial toxin released by S. pneumoniae, in triggering complement activation has been studied in vitro. Our results demonstrate that in both human and mouse sera complement was activated via the CP, initiated by direct binding of even non-specific IgM and IgG3 to PLY. Absence of CP activity in C1q−/− mouse serum completely abolished any C3 deposition. However, C1q depleted human serum strongly opsonized PLY through abundant deposition of C3 activation products, indicating that the LP may have a vital role in activating the human complement system on PLY. We identified that human L-ficolin is the critical LP recognition molecule that drives LP activation on PLY, while all of the murine LP recognition components fail to bind and activate complement on PLY. This work elucidates the detailed interactions between PLY and complement and shows for the first time a specific role of the LP in PLY-mediated complement activation in human serum. PMID:24349316

Inhibition of the Membrane Attack Complex by Dengue Virus NS1 through Interaction with Vitronectin and Terminal Complement Proteins

PubMed Central

Conde, Jonas Nascimento; da Silva, Emiliana Mandarano; Allonso, Diego; Coelho, Diego Rodrigues; Andrade, Iamara da Silva; de Medeiros, Luciano Neves; Menezes, Joice Lima; Barbosa, Angela Silva

2016-01-01

ABSTRACT Dengue virus (DENV) infects millions of people worldwide and is a major public health problem. DENV nonstructural protein 1 (NS1) is a conserved glycoprotein that associates with membranes and is also secreted into the plasma in DENV-infected patients. The present study describes a novel mechanism by which NS1 inhibits the terminal complement pathway. We first identified the terminal complement regulator vitronectin (VN) as a novel DENV2 NS1 binding partner by using a yeast two-hybrid system. This interaction was further assessed by enzyme-linked immunosorbent assay (ELISA) and surface plasmon resonance (SPR) assay. The NS1-VN complex was also detected in plasmas from DENV-infected patients, suggesting that this interaction occurs during DENV infection. We also demonstrated that the DENV2 NS1 protein, either by itself or by interacting with VN, hinders the formation of the membrane attack complex (MAC) and C9 polymerization. Finally, we showed that DENV2, West Nile virus (WNV), and Zika virus (ZIKV) NS1 proteins produced in mammalian cells inhibited C9 polymerization. Taken together, our results points to a role for NS1 as a terminal pathway inhibitor of the complement system. IMPORTANCE Dengue is the most important arthropod-borne viral disease nowadays and is caused by dengue virus (DENV). The flavivirus NS1 glycoprotein has been characterized functionally as a complement evasion protein that can attenuate the activation of the classical, lectin, and alternative pathways. The present study describes a novel mechanism by which DENV NS1 inhibits the terminal complement pathway. We identified the terminal complement regulator vitronectin (VN) as a novel DENV NS1 binding partner, and the NS1-VN complex was detected in plasmas from DENV-infected patients, suggesting that this interaction occurs during DENV infection. We also demonstrated that the NS1-VN complex inhibited membrane attack complex (MAC) formation, thus interfering with the complement terminal pathway. Interestingly, NS1 itself also inhibited MAC activity, suggesting a direct role of this protein in the inhibition process. Our findings imply a role for NS1 as a terminal pathway inhibitor of the complement system. PMID:27512066

Innate immune humoral factors, C1q and factor H, with differential pattern recognition properties, alter macrophage response to carbon nanotubes.

PubMed

Pondman, Kirsten M; Pednekar, Lina; Paudyal, Basudev; Tsolaki, Anthony G; Kouser, Lubna; Khan, Haseeb A; Shamji, Mohamed H; Ten Haken, Bennie; Stenbeck, Gudrun; Sim, Robert B; Kishore, Uday

2015-11-01

Interaction between the complement system and carbon nanotubes (CNTs) can modify their intended biomedical applications. Pristine and derivatised CNTs can activate complement primarily via the classical pathway which enhances uptake of CNTs and suppresses pro-inflammatory response by immune cells. Here, we report that the interaction of C1q, the classical pathway recognition molecule, with CNTs involves charge pattern and classical pathway activation that is partly inhibited by factor H, a complement regulator. C1q and its globular modules, but not factor H, enhanced uptake of CNTs by macrophages and modulated the pro-inflammatory immune response. Thus, soluble complement factors can interact differentially with CNTs and alter the immune response even without complement activation. Coating CNTs with recombinant C1q globular heads offers a novel way of controlling classical pathway activation in nanotherapeutics. Surprisingly, the globular heads also enhance clearance by phagocytes and down-regulate inflammation, suggesting unexpected complexity in receptor interaction. Carbon nanotubes (CNTs) maybe useful in the clinical setting as targeting drug carriers. However, it is also well known that they can interact and activate the complement system, which may have a negative impact on the applicability of CNTs. In this study, the authors functionalized multi-walled CNT (MWNT), and investigated the interaction with the complement pathway. These studies are important so as to gain further understanding of the underlying mechanism in preparation for future use of CNTs in the clinical setting. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Second hit in cervical carcinogenesis process: involvement of wnt/beta catenin pathway

PubMed Central

Perez-Plasencia, Carlos; Duenas-Gonzalez, Alfonso; Alatorre-Tavera, Brenda

2008-01-01

The Human papillomavirus plays an important role in the initiation and progression of cervical cancer. However, it is a necessary but not sufficient cause to develop invasive carcinoma; hence, other factors are required in the pathogenesis of this malignancy. In this review we explore the hypothesis of the deregulation of wnt/β-catenin signaling pathway as a "second hit" required to develop cervical cancer. PMID:18606007

Activation of the classical pathway of complement by binding of bovine lactoferrin to unencapsulated Streptococcus agalactiae.

PubMed Central

Rainard, P

1993-01-01

The ability of lactoferrin (Lf) bound to Streptococcus agalactiae to interfere with the deposition of complement components on the bacterial surface was investigated by enzyme-linked immunosorbent assay (ELISA). By using a strain of S. agalactiae which activates the alternative pathway of complement in the absence of antibodies, it was found that pretreatment of bacteria with Lf shortened the lag phase preceding the deposition of C3 on bacteria. The kinetics of C3 deposition was comparable to that obtained by adding antibodies against S. agalactiae to agammaglobulinaemic precolostral calf serum (PCS) heated at 56 degrees for 3 min to inactivate the alternative pathway. Accelerated C3 deposition did not occur in the absence of Ca2+ ions. Deposition of C4 on bacteria occurred only when either antibodies or Lf were added to PCS. These results demonstrate that the interaction of lactoferrin with bacteria activated the classical pathway of complement in the absence of antibodies. The binding of purified C1q to bacteria was promoted in a dose-dependent manner by Lf, suggesting that recruitment of classical pathway of complement resulted from the interaction of C1q with Lf adsorbed to the bacterial surface. Phagocytosis of bacteria opsonized with heated PCS (at 56 degrees for 3 min) and Lf was comparable to that occurring in the presence of heated PCS and antibodies. In conclusion, Lf was able to substitute for antibodies in order to activate the classical pathway of complement and to opsonize unencapsulated S. agalactiae efficiently. PMID:8406591

The Lectin Pathway of Complement and Rheumatic Heart Disease

PubMed Central

Beltrame, Marcia Holsbach; Catarino, Sandra Jeremias; Goeldner, Isabela; Boldt, Angelica Beate Winter; de Messias-Reason, Iara José

2014-01-01

The innate immune system is the first line of host defense against infection and is comprised of humoral and cellular mechanisms that recognize potential pathogens within minutes or hours of entry. The effector components of innate immunity include epithelial barriers, phagocytes, and natural killer cells, as well as cytokines and the complement system. Complement plays an important role in the immediate response against microorganisms, including Streptococcus sp. The lectin pathway is one of three pathways by which the complement system can be activated. This pathway is initiated by the binding of mannose-binding lectin (MBL), collectin 11 (CL-K1), and ficolins (Ficolin-1, Ficolin-2, and Ficolin-3) to microbial surface oligosaccharides and acetylated residues, respectively. Upon binding to target molecules, MBL, CL-K1, and ficolins form complexes with MBL-associated serine proteases 1 and 2 (MASP-1 and MASP-2), which cleave C4 and C2 forming the C3 convertase (C4b2a). Subsequent activation of complement cascade leads to opsonization, phagocytosis, and lysis of target microorganisms through the formation of the membrane-attack complex. In addition, activation of complement may induce several inflammatory effects, such as expression of adhesion molecules, chemotaxis and activation of leukocytes, release of reactive oxygen species, and secretion of cytokines and chemokines. In this chapter, we review the general aspects of the structure, function, and genetic polymorphism of lectin-pathway components and discuss most recent understanding on the role of the lectin pathway in the predisposition and clinical progression of Rheumatic Fever. PMID:25654073

Frequent Deregulations in the Hedgehog Signaling Network and Cross-Talks with the Epidermal Growth Factor Receptor Pathway Involved in Cancer Progression and Targeted Therapies

PubMed Central

Mimeault, Murielle

2010-01-01

The hedgehog (Hh)/glioma-associated oncogene (GLI) signaling network is among the most important and fascinating signal transduction systems that provide critical functions in the regulation of many developmental and physiological processes. The coordinated spatiotemporal interplay of the Hh ligands and other growth factors is necessary for the stringent control of the behavior of diverse types of tissue-resident stem/progenitor cells and their progenies. The activation of the Hh cascade might promote the tissue regeneration and repair after severe injury in numerous organs, insulin production in pancreatic β-cells, and neovascularization. Consequently, the stimulation of the Hh pathway constitutes a potential therapeutic strategy to treat diverse human disorders, including severe tissue injuries; diabetes mellitus; and brain, skin, and cardiovascular disorders. In counterbalance, a deregulation of the Hh signaling network might lead to major tissular disorders and the development of a wide variety of aggressive and metastatic cancers. The target gene products induced through the persistent Hh activation can contribute to the self-renewal, survival, migration, and metastasis of cancer stem/progenitor cells and their progenies. Moreover, the pivotal role mediated through the Hh/GLI cascade during cancer progression also implicates the cooperation with other oncogenic products, such as mutated K-RAS and complex cross-talk with different growth factor pathways, including tyrosine kinase receptors, such as epidermal growth factor receptor (EGFR), Wnt/β-catenin, and transforming growth factor-β (TGF-β)/TGF-β receptors. Therefore, the molecular targeting of distinct deregulated gene products, including Hh and EGFR signaling components and other signaling elements that are frequently deregulated in highly tumorigenic cancer-initiating cells and their progenies, might constitute a potential therapeutic strategy to eradicate the total cancer cell mass. Of clinical interest is that these multitargeted approaches offer great promise as adjuvant treatments for improving the current antihormonal therapies, radiotherapies, and/or chemotherapies against locally advanced and metastatic cancers, thereby preventing disease relapse and the death of patients with cancer. PMID:20716670

Comparison of transcriptomic signature of post-Chernobyl and postradiotherapy thyroid tumors.

PubMed

Ory, Catherine; Ugolin, Nicolas; Hofman, Paul; Schlumberger, Martin; Likhtarev, Illya A; Chevillard, Sylvie

2013-11-01

We previously identified two highly discriminating and predictive radiation-induced transcriptomic signatures by comparing series of sporadic and postradiotherapy thyroid tumors (322-gene signature), and by reanalyzing a previously published data set of sporadic and post-Chernobyl thyroid tumors (106-gene signature). The aim of the present work was (i) to compare the two signatures in terms of gene expression deregulations and molecular features/pathways, and (ii) to test the capacity of the postradiotherapy signature in classifying the post-Chernobyl series of tumors and reciprocally of the post-Chernobyl signature in classifying the postradiotherapy-induced tumors. We now explored if postradiotherapy and post-Chernobyl papillary thyroid carcinomas (PTC) display common molecular features by comparing molecular pathways deregulated in the two tumor series, and tested the potential of gene subsets of the postradiotherapy signature to classify the post-Chernobyl series (14 sporadic and 12 post-Chernobyl PTC), and reciprocally of gene subsets of the post-Chernobyl signature to classify the postradiotherapy series (15 sporadic and 12 postradiotherapy PTC), by using conventional principal component analysis. We found that the five genes common to the two signatures classified the learning/training tumors (used to search these signatures) of both the postradiotherapy (seven PTC) and the post-Chernobyl (six PTC) thyroid tumor series as compared with the sporadic tumors (seven sporadic PTC in each series). Importantly, these five genes were also effective for classifying independent series of postradiotherapy (five PTC) and post-Chernobyl (six PTC) tumors compared to independent series of sporadic tumors (eight PTC and six PTC respectively; testing tumors). Moreover, part of each postradiotherapy (32 genes) and post-Chernobyl signature (16 genes) cross-classified the respective series of thyroid tumors. Finally, several molecular pathways deregulated in post-Chernobyl tumors matched those found to be deregulated in postradiotherapy tumors. Overall, our data suggest that thyroid tumors that developed following either external exposure or internal (131)I contamination shared common molecular features, related to DNA repair, oxidative and endoplasmic reticulum stresses, allowing their classification as radiation-induced tumors in comparison with sporadic counterparts, independently of doses and dose rates, which suggests there may be a "general" radiation-induced signature of thyroid tumors.

Discontinuation of dialysis with eculizumab therapy in a pediatric patient with dense deposit disease.

PubMed

Tran, Cheryl L; Sethi, Sanjeev; Murray, David; Cramer, Carl H; Sas, David J; Willrich, Maria; Smith, Richard J; Fervenza, Fernando C

2016-04-01

Dense deposit disease (DDD) is a rare glomerular disease caused by an uncontrolled activation of the alternative complement pathway leading to end-stage renal disease in 50 % of patients. As such, DDD has been classified within the spectrum of complement component 3 (C3) glomerulopathies due to its pathogenesis from alternative pathway dysregulation. Conventional immunosuppressive therapies have no proven effectiveness. Eculizumab, a terminal complement inhibitor, has been reported to mitigate disease in some cases. We report on the efficacy of eculizumab in a pediatric patient who failed to respond to cyclophosphamide, corticosteroids, and plasma exchange. Complement biomarker profiling was remarkable for low serum C3, low properdin, and elevated soluble C5b-9. Consistent with these findings, the alternative pathway functional assay was abnormally low, indicative of alternative pathway activity, although neither C3-nephritic factors nor Factor H autoantibodies were detected. Eculizumab therapy was associated with significant improvement in proteinuria and renal function allowing discontinuation of hemodialysis (HD). Repeat C3 and soluble C5b-9 levels normalized, showing that terminal complement pathway activity was successfully blocked while the patient was receiving eculizumab therapy. Repeat testing for alternative pathway activation allowed for a successful decrease in eculizumab dosing. The case reported here demonstrates the successful recovery of renal function in a pediatric patient on HD following the use of eculizumab.

Relevance of small GTPase Rac1 pathway in drug and radio-resistance mechanisms: Opportunities in cancer therapeutics.

PubMed

Cardama, G A; Alonso, D F; Gonzalez, N; Maggio, J; Gomez, D E; Rolfo, C; Menna, P L

2018-04-01

Rac1 GTPase signaling pathway has a critical role in the regulation of a plethora of cellular functions governing cancer cell behavior. Recently, it has been shown a critical role of Rac1 in the emergence of resistance mechanisms to cancer therapy. This review describes the current knowledge regarding Rac1 pathway deregulation and its association with chemoresistance, radioresistance, resistance to targeted therapies and immune evasion. This supports the idea that interfering Rac1 signaling pathway could be an interesting approach to tackle cancer resistance. Copyright © 2018 Elsevier B.V. All rights reserved.

Deregulation of obesity-relevant genes is associated with progression in BMI and the amount of adipose tissue in pigs.

PubMed

Mentzel, Caroline M Junker; Cardoso, Tainã Figueiredo; Pipper, Christian Bressen; Jacobsen, Mette Juul; Jørgensen, Claus Bøttcher; Cirera, Susanna; Fredholm, Merete

2018-02-01

The aim of this study was to elucidate the relative impact of three phenotypes often used to characterize obesity on perturbation of molecular pathways involved in obesity. The three obesity-related phenotypes are (1) body mass index (BMI), (2) amount of subcutaneous adipose tissue (SATa), and (3) amount of retroperitoneal adipose tissue (RPATa). Although it is generally accepted that increasing amount of RPATa is 'unhealthy', a direct comparison of the relative impact of the three obesity-related phenotypes on gene expression has, to our knowledge, not been performed previously. We have used multiple linear models to analyze altered gene expression of selected obesity-related genes in tissues collected from 19 female pigs phenotypically characterized with respect to the obesity-related phenotypes. Gene expression was assessed by high-throughput qPCR in RNA from liver, skeletal muscle and abdominal adipose tissue. The stringent statistical approach used in the study has increased the power of the analysis compared to the classical approach of analysis in divergent groups of individuals. Our approach led to the identification of key components of cellular pathways that are modulated in the three tissues in association with changes in the three obesity-relevant phenotypes (BMI, SATa and RPATa). The deregulated pathways are involved in biosynthesis and transcript regulation in adipocytes, in lipid transport, lipolysis and metabolism, and in inflammatory responses. Deregulation seemed more comprehensive in liver (23 genes) compared to abdominal adipose tissue (10 genes) and muscle (3 genes). Notably, the study supports the notion that excess amount of intra-abdominal adipose tissue is associated with a greater metabolic disease risk. Our results provide molecular support for this notion by demonstrating that increasing amount of RPATa has a higher impact on perturbation of cellular pathways influencing obesity and obesity-related metabolic traits compared to increase in BMI and amount of SATa.

Human T-Cell Leukemia Virus Type 1 Tax-Deregulated Autophagy Pathway and c-FLIP Expression Contribute to Resistance against Death Receptor-Mediated Apoptosis

PubMed Central

Wang, Weimin; Zhou, Jiansuo; Shi, Juan; Zhang, Yaxi; Liu, Shilian

2014-01-01

ABSTRACT The human T-cell leukemia virus type 1 (HTLV-1) Tax protein is considered to play a central role in the process that leads to adult T-cell leukemia/lymphoma (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). HTLV-1 Tax-expressing cells show resistance to apoptosis induced by Fas ligand (FasL) and tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL). The regulation of Tax on the autophagy pathway in HeLa cells and peripheral T cells was recently reported, but the function and underlying molecular mechanism of the Tax-regulated autophagy are not yet well defined. Here, we report that HTLV-1 Tax deregulates the autophagy pathway, which plays a protective role during the death receptor (DR)-mediated apoptosis of human U251 astroglioma cells. The cellular FLICE-inhibitory protein (c-FLIP), which is upregulated by Tax, also contributes to the resistance against DR-mediated apoptosis. Both Tax-induced autophagy and Tax-induced c-FLIP expression require Tax-induced activation of IκB kinases (IKK). Furthermore, Tax-induced c-FLIP expression is regulated through the Tax-IKK-NF-κB signaling pathway, whereas Tax-triggered autophagy depends on the activation of IKK but not the activation of NF-κB. In addition, DR-mediated apoptosis is correlated with the degradation of Tax, which can be facilitated by the inhibitors of autophagy. IMPORTANCE Our study reveals that Tax-deregulated autophagy is a protective mechanism for DR-mediated apoptosis. The molecular mechanism of Tax-induced autophagy is also illuminated, which is different from Tax-increased c-FLIP. Tax can be degraded via manipulation of autophagy and TRAIL-induced apoptosis. These results outline a complex regulatory network between and among apoptosis, autophagy, and Tax and also present evidence that autophagy represents a new possible target for therapeutic intervention for the HTVL-1 related diseases. PMID:24352466

Complement Evasion Strategies of Viruses: An Overview

PubMed Central

Agrawal, Palak; Nawadkar, Renuka; Ojha, Hina; Kumar, Jitendra; Sahu, Arvind

2017-01-01

Being a major first line of immune defense, the complement system keeps a constant vigil against viruses. Its ability to recognize large panoply of viruses and virus-infected cells, and trigger the effector pathways, results in neutralization of viruses and killing of the infected cells. This selection pressure exerted by complement on viruses has made them evolve a multitude of countermeasures. These include targeting the recognition molecules for the avoidance of detection, targeting key enzymes and complexes of the complement pathways like C3 convertases and C5b-9 formation – either by encoding complement regulators or by recruiting membrane-bound and soluble host complement regulators, cleaving complement proteins by encoding protease, and inhibiting the synthesis of complement proteins. Additionally, viruses also exploit the complement system for their own benefit. For example, they use complement receptors as well as membrane regulators for cellular entry as well as their spread. Here, we provide an overview on the complement subversion mechanisms adopted by the members of various viral families including Poxviridae, Herpesviridae, Adenoviridae, Flaviviridae, Retroviridae, Picornaviridae, Astroviridae, Togaviridae, Orthomyxoviridae and Paramyxoviridae. PMID:28670306

Embryonic Lethality Due to Arrested Cardiac Development in Psip1/Hdgfrp2 Double-Deficient Mice.

PubMed

Wang, Hao; Shun, Ming-Chieh; Dickson, Amy K; Engelman, Alan N

2015-01-01

Hepatoma-derived growth factor (HDGF) related protein 2 (HRP2) and lens epithelium-derived growth factor (LEDGF)/p75 are closely related members of the HRP2 protein family. LEDGF/p75 has been implicated in numerous human pathologies including cancer, autoimmunity, and infectious disease. Knockout of the Psip1 gene, which encodes for LEDGF/p75 and the shorter LEDGF/p52 isoform, was previously shown to cause perinatal lethality in mice. The function of HRP2 was by contrast largely unknown. To learn about the role of HRP2 in development, we knocked out the Hdgfrp2 gene, which encodes for HRP2, in both normal and Psip1 knockout mice. Hdgfrp2 knockout mice developed normally and were fertile. By contrast, the double deficient mice died at approximate embryonic day (E) 13.5. Histological examination revealed ventricular septal defect (VSD) associated with E14.5 double knockout embryos. To investigate the underlying molecular mechanism(s), RNA recovered from ventricular tissue was subjected to RNA-sequencing on the Illumina platform. Bioinformatic analysis revealed several genes and biological pathways that were significantly deregulated by the Psip1 knockout and/or Psip1/Hdgfrp2 double knockout. Among the dozen genes known to encode for LEDGF/p75 binding factors, only the expression of Nova1, which encodes an RNA splicing factor, was significantly deregulated by the knockouts. However the expression of other RNA splicing factors, including the LEDGF/p52-interacting protein ASF/SF2, was not significantly altered, indicating that deregulation of global RNA splicing was not a driving factor in the pathology of the VSD. Tumor growth factor (Tgf) β-signaling, which plays a key role in cardiac morphogenesis during development, was the only pathway significantly deregulated by the double knockout as compared to control and Psip1 knockout samples. We accordingly speculate that deregulated Tgf-β signaling was a contributing factor to the VSD and prenatal lethality of Psip1/Hdgfrp2 double-deficient mice.

Gene Profiling in Patients with Systemic Sclerosis Reveals the Presence of Oncogenic Gene Signatures

PubMed Central

Dolcino, Marzia; Pelosi, Andrea; Fiore, Piera Filomena; Patuzzo, Giuseppe; Tinazzi, Elisa; Lunardi, Claudio; Puccetti, Antonio

2018-01-01

Systemic sclerosis (SSc) is a rare connective tissue disease characterized by three pathogenetic hallmarks: vasculopathy, dysregulation of the immune system, and fibrosis. A particular feature of SSc is the increased frequency of some types of malignancies, namely breast, lung, and hematological malignancies. Moreover, SSc may also be a paraneoplastic disease, again indicating a strong link between cancer and scleroderma. The reason of this association is still unknown; therefore, we aimed at investigating whether particular genetic or epigenetic factors may play a role in promoting cancer development in patients with SSc and whether some features are shared by the two conditions. We therefore performed a gene expression profiling of peripheral blood mononuclear cells (PBMCs) derived from patients with limited and diffuse SSc, showing that the various classes of genes potentially linked to the pathogenesis of SSc (such as apoptosis, endothelial cell activation, extracellular matrix remodeling, immune response, and inflammation) include genes that directly participate in the development of malignancies or that are involved in pathways known to be associated with carcinogenesis. The transcriptional analysis was then complemented by a complex network analysis of modulated genes which further confirmed the presence of signaling pathways associated with carcinogenesis. Since epigenetic mechanisms, such as microRNAs (miRNAs), are believed to play a central role in the pathogenesis of SSc, we also evaluated whether specific cancer-related miRNAs could be deregulated in the serum of SSc patients. We focused our attention on miRNAs already found upregulated in SSc such as miR-21-5p, miR-92a-3p, and on miR-155-5p, miR 126-3p and miR-16-5p known to be deregulated in malignancies associated to SSc, i.e., breast, lung, and hematological malignancies. miR-21-5p, miR-92a-3p, miR-155-5p, and miR-16-5p expression was significantly higher in SSc sera compared to healthy controls. Our findings indicate the presence of modulated genes and miRNAs that can play a predisposing role in the development of malignancies in SSc and are important for a better risk stratification of patients and for the identification of a better individualized precision medicine strategy. PMID:29559981

Sorafenib: targeting multiple tyrosine kinases in cancer.

PubMed

Hasskarl, Jens

2014-01-01

Sorafenib (BAY 43-9006, Nexavar®) is an oral multiple tyrosine kinase inhibitor. Main targets are receptor tyrosine kinase pathways frequently deregulated in cancer such as the Raf-Ras pathway, vascular endothelial growth factor (VEGF) pathway, and FMS-like tyrosine kinase 3 (FLT3). Sorafenib was approved by the FDA in fast track for advanced renal cell cancer and hepatocellular cancer and shows good clinical activity in thyroid cancer. Multiple clinical trials are undertaken to further investigate the role of sorafenib alone or in combination for the treatment of various tumor entities.

Mannose Binding Lectin Is Required for Alphavirus-Induced Arthritis/Myositis

PubMed Central

Whitmore, Alan C.; Blevins, Lance K.; Hueston, Linda; Fraser, Robert J.; Herrero, Lara J.; Ramirez, Ruben; Smith, Paul N.; Mahalingam, Suresh; Heise, Mark T.

2012-01-01

Mosquito-borne alphaviruses such as chikungunya virus and Ross River virus (RRV) are emerging pathogens capable of causing large-scale epidemics of virus-induced arthritis and myositis. The pathology of RRV-induced disease in both humans and mice is associated with induction of the host inflammatory response within the muscle and joints, and prior studies have demonstrated that the host complement system contributes to development of disease. In this study, we have used a mouse model of RRV-induced disease to identify and characterize which complement activation pathways mediate disease progression after infection, and we have identified the mannose binding lectin (MBL) pathway, but not the classical or alternative complement activation pathways, as essential for development of RRV-induced disease. MBL deposition was enhanced in RRV infected muscle tissue from wild type mice and RRV infected MBL deficient mice exhibited reduced disease, tissue damage, and complement deposition compared to wild-type mice. In contrast, mice deficient for key components of the classical or alternative complement activation pathways still developed severe RRV-induced disease. Further characterization of MBL deficient mice demonstrated that similar to C3−/− mice, viral replication and inflammatory cell recruitment were equivalent to wild type animals, suggesting that RRV-mediated induction of complement dependent immune pathology is largely MBL dependent. Consistent with these findings, human patients diagnosed with RRV disease had elevated serum MBL levels compared to healthy controls, and MBL levels in the serum and synovial fluid correlated with severity of disease. These findings demonstrate a role for MBL in promoting RRV-induced disease in both mice and humans and suggest that the MBL pathway of complement activation may be an effective target for therapeutic intervention for humans suffering from RRV-induced arthritis and myositis. PMID:22457620

Glomeruli of Dense Deposit Disease contain components of the alternative and terminal complement pathway

PubMed Central

Sethi, Sanjeev; Gamez, Jeffrey D.; Vrana, Julie A.; Theis, Jason D.; Bergen, H. Robert; Zipfel, Peter F.; Dogan, Ahmet; Smith, Richard J. H.

2009-01-01

Dense Deposit Disease (DDD), or membranoproliferative glomerulonephritis type II, is a rare renal disease characterized by dense deposits in the mesangium and along the glomerular basement membranes that can be seen by electron microscopy. Although these deposits contain complement factor C3, as determined by immunofluorescence microscopy, their precise composition remains unknown. To address this question, we used mass spectrometry to identify the proteins in laser microdissected glomeruli isolated from paraffin-embedded tissue of eight confirmed cases of DDD. Compared to glomeruli from five control patients, we found that all of the glomeruli from patients with DDD contain components of the alternative pathway and terminal complement complex. Factor C9 was uniformly present as well as the two fluid-phase regulators of terminal complement complex clusterin and vitronectin. In contrast, in nine patients with immune complex–mediated membranoproliferative glomerulonephritis, glomerular samples contained mainly immunoglobulins and complement factors C3 and C4. Our study shows that in addition to fluid-phase dysregulation of the alternative pathway, soluble components of the terminal complement complex contribute to glomerular lesions found in DDD. PMID:19177158

The critical protein interactions and structures that elicit growth deregulation in cancer and viral replication

PubMed Central

Ou, Horng D.; May, Andrew P.

2010-01-01

One of the greatest challenges in biomedicine is to define the critical targets and network interactions that are subverted to elicit growth deregulation in human cells. Understanding and developing rational treatments for cancer requires a definition of the key molecular targets and how they interact to elicit the complex growth deregulation phenotype. Viral proteins provide discerning and powerful probes to understand both how cells work and how they can be manipulated using a minimal number of components. The small DNA viruses have evolved to target inherent weaknesses in cellular protein interaction networks to hijack the cellular DNA and protein replication machinery. In the battle to escape the inevitability of senescence and programmed cell death, cancers have converged on similar mechanisms, through the acquisition and selection of somatic mutations that drive unchecked cellular replication in tumors. Understanding the dynamic mechanisms through which a minimal number of viral proteins promote host cells to undergo unscheduled and pathological replication is a powerful strategy to identify critical targets that are also disrupted in cancer. Viruses can therefore be used as tools to probe the system-wide protein-protein interactions and structures that drive growth deregulation in human cells. Ultimately this can provide a path for developing system context-dependent therapeutics. This review will describe ongoing experimental approaches using viruses to study pathways deregulated in cancer, with a particular focus on viral cellular protein-protein interactions and structures. PMID:21061422

Deregulation of Genes Associated with Alternate Drug Resistance Mechanisms in Mycobacterium tuberculosis.

PubMed

Sriraman, Kalpana; Nilgiriwala, Kayzad; Saranath, Dhananjaya; Chatterjee, Anirvan; Mistry, Nerges

2018-04-01

Alternate mechanisms of drug resistance involving intrinsic defense pathways play an important role in development of drug resistance. Deregulation of drug efflux, cellular metabolism, and DNA repair have been indicated to have effect on drug tolerance and persistence. Here we chose eight genes from these pathways to investigate their association with development of multidrug resistance (MDR). We generated mono drug resistant and MDR strains of rifampicin and isoniazid and examined the differential expression of genes belonging to efflux, DNA repair and cell wall lipid synthesis pathways. Rv1687c, recB, ppsD and embC genes showed significant (P <0.05) upregulation in mono-resistant (both rifampicin and isoniazid) as well as MDR strains. mmr showed significant upregulation with rifampicin resistance while Rv1457c showed significant upregulation only with mono-resistant strains. Highest expression change was observed with Rv1687c and ppsD. The study identified potential key genes that are significantly associated with development of drug resistance in vitro. These genes may help identify clinical strains predisposed to acquiring drug resistance in patients during the course of treatment or help in management of MDR forms of tuberculosis.

NF-κB deregulation in splenic marginal zone lymphoma.

PubMed

Spina, Valeria; Rossi, Davide

2016-08-01

Splenic marginal zone lymphoma is a rare mature B-cell malignancy involving the spleen, bone marrow and blood. Over the past years, the rapid expansion of sequencing technologies allowing the genome-wide assessment of genomic, epigenetic and transcriptional changes has revolutionized our understanding of the biological basis of splenic marginal zone lymphoma by providing a comprehensive and unbiased view of the genes/pathways that are deregulated in this disease. NF-κB is a family of transcription factors that plays critical roles in development, survival, and activation of B lymphocytes. Consistent with the physiological involvement of NF-κB signalling in proliferation and commitment of mature B-cells to the marginal zone of the spleen, many oncogenic mutations involved in constitutive activation of the NF-κB pathway were recently identified in splenic marginal zone lymphoma. This review describes the progress in understanding the mechanism of NF-κB activation in splenic marginal zone lymphoma, including molecular, epigenetic and post-transcriptional modifications of NF-κB genes and of upstream pathways, and discusses how information gained from these efforts has provided new insights on potential targets of diagnostic, prognostic and therapeutic relevance for splenic marginal zone lymphoma. Copyright © 2016. Published by Elsevier Ltd.

Neuroendocrine deregulation of food intake, adipose tissue and the gastrointestinal system in obesity and metabolic syndrome.

PubMed

Garruti, Gabriella; Cotecchia, Susanna; Giampetruzzi, Federica; Giorgino, Francesco; Giorgino, Riccardo

2008-06-01

Obesity is an excess of fat mass. Fat mass is an energy depot but also an endocrine organ. A deregulation of the sympathetic nervous system (SNS) might produce obesity. Stress exaggerates diet-induced obesity. After stress, SNS fibers release neuropeptide Y (NPY) which directly increases visceral fat mass producing a metabolic syndrome (MbS)-like phenotype. Adrenergic receptors are the main regulators of lipolysis. In severe obesity, we demonstrated that the adrenergic receptor subtypes are differentially expressed in different fat depots. Liver and visceral fat share a common sympathetic pathway, which might explain the low-grade inflammation which simultaneously occurs in liver and fat of the obese with MbS. The neuroendocrine melanocortinergic system and gastric ghrelin are also greatly deregulated in obesity. A specific mutation in the type 4 melanocortin receptor induces early obesity onset, hyperphagia and insulin-resistance. Nonetheless, it was recently discovered that a mutation in the prohormone convertase 1/3 simultaneously produces severe gastrointestinal dysfunctions and obesity.

Different host complement systems and their interactions with saliva from Lutzomyia longipalpis (Diptera, Psychodidae) and Leishmania infantum promastigotes.

PubMed

Mendes-Sousa, Antonio Ferreira; Nascimento, Alexandre Alves Sousa; Queiroz, Daniel Costa; Vale, Vladimir Fazito; Fujiwara, Ricardo Toshio; Araújo, Ricardo Nascimento; Pereira, Marcos Horácio; Gontijo, Nelder Figueiredo

2013-01-01

Lutzomyia longipalpis is the vector of Leishmania infantum in the New World, and its saliva inhibits classical and alternative human complement system pathways. This inhibition is important in protecting the insect´s midgut from damage by the complement. L. longipalpis is a promiscuous blood feeder and must be protected against its host's complement. The objective of this study was to investigate the action of salivary complement inhibitors on the sera of different host species, such as dogs, guinea pigs, rats and chickens, at a pH of 7.4 (normal blood pH) and 8.15 (the midgut pH immediately after a blood meal). We also investigated the role of the chicken complement system in Leishmania clearance in the presence and absence of vector saliva. The saliva was capable of inhibiting classical pathways in dogs, guinea pigs and rats at both pHs. The alternative pathway was not inhibited except in dogs at a pH of 8.15. The chicken classical pathway was inhibited only by high concentrations of saliva and it was better inhibited by the midgut contents of sand flies. Neither the saliva nor the midgut contents had any effect on the avian alternative pathway. Fowl sera killed L. infantum promastigotes, even at a low concentration (2%), and the addition of L. longipalpis saliva did not protect the parasites. The high body temperature of chickens (40°C) had no effect on Leishmania viability during our assays. Salivary inhibitors act in a species-specific manner. It is important to determine their effects in the natural hosts of Leishmania infantum because they act on canid and rodent complements but not on chickens (which do not harbour the parasite). Moreover, we concluded that the avian complement system is the probable mechanism through which chickens eliminate Leishmania and that their high body temperature does not influence this parasite.

Inhibition of the Membrane Attack Complex by Dengue Virus NS1 through Interaction with Vitronectin and Terminal Complement Proteins.

PubMed

Conde, Jonas Nascimento; da Silva, Emiliana Mandarano; Allonso, Diego; Coelho, Diego Rodrigues; Andrade, Iamara da Silva; de Medeiros, Luciano Neves; Menezes, Joice Lima; Barbosa, Angela Silva; Mohana-Borges, Ronaldo

2016-11-01

Dengue virus (DENV) infects millions of people worldwide and is a major public health problem. DENV nonstructural protein 1 (NS1) is a conserved glycoprotein that associates with membranes and is also secreted into the plasma in DENV-infected patients. The present study describes a novel mechanism by which NS1 inhibits the terminal complement pathway. We first identified the terminal complement regulator vitronectin (VN) as a novel DENV2 NS1 binding partner by using a yeast two-hybrid system. This interaction was further assessed by enzyme-linked immunosorbent assay (ELISA) and surface plasmon resonance (SPR) assay. The NS1-VN complex was also detected in plasmas from DENV-infected patients, suggesting that this interaction occurs during DENV infection. We also demonstrated that the DENV2 NS1 protein, either by itself or by interacting with VN, hinders the formation of the membrane attack complex (MAC) and C9 polymerization. Finally, we showed that DENV2, West Nile virus (WNV), and Zika virus (ZIKV) NS1 proteins produced in mammalian cells inhibited C9 polymerization. Taken together, our results points to a role for NS1 as a terminal pathway inhibitor of the complement system. Dengue is the most important arthropod-borne viral disease nowadays and is caused by dengue virus (DENV). The flavivirus NS1 glycoprotein has been characterized functionally as a complement evasion protein that can attenuate the activation of the classical, lectin, and alternative pathways. The present study describes a novel mechanism by which DENV NS1 inhibits the terminal complement pathway. We identified the terminal complement regulator vitronectin (VN) as a novel DENV NS1 binding partner, and the NS1-VN complex was detected in plasmas from DENV-infected patients, suggesting that this interaction occurs during DENV infection. We also demonstrated that the NS1-VN complex inhibited membrane attack complex (MAC) formation, thus interfering with the complement terminal pathway. Interestingly, NS1 itself also inhibited MAC activity, suggesting a direct role of this protein in the inhibition process. Our findings imply a role for NS1 as a terminal pathway inhibitor of the complement system. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Distinct polymer architecture mediates switching of complement activation pathways at the nanosphere-serum interface: implications for stealth nanoparticle engineering.

PubMed

Hamad, Islam; Al-Hanbali, Othman; Hunter, A Christy; Rutt, Kenneth J; Andresen, Thomas L; Moghimi, S Moein

2010-11-23

Nanoparticles with surface projected polyethyleneoxide (PEO) chains in "mushroom-brush" and "brush" configurations display stealth properties in systemic circulation and have numerous applications in site-specific targeting for controlled drug delivery and release as well as diagnostic imaging. We report on the "structure-activity" relationship pertaining to surface-immobilized PEO of various configurations on model nanoparticles, and the initiation of complement cascade, which is the most ancient component of innate human immunity, and its activation may induce clinically significant adverse reactions in some individuals. Conformational states of surface-projected PEO chains, arising from the block copolymer poloxamine 908 adsorption, on polystyrene nanoparticles trigger complement activation differently. Alteration of copolymer architecture on nanospheres from mushroom to brush configuration not only switches complement activation from C1q-dependent classical to lectin pathway but also reduces the level of generated complement activation products C4d, Bb, C5a, and SC5b-9. Also, changes in adsorbed polymer configuration trigger alternative pathway activation differently and through different initiators. Notably, the role for properdin-mediated activation of alternative pathway was only restricted to particles displaying PEO chains in a transition mushroom-brush configuration. Since nanoparticle-mediated complement activation is of clinical concern, our findings provide a rational basis for improved surface engineering and design of immunologically safer stealth and targetable nanosystems with polymers for use in clinical medicine.

Cyclosporine Induces Endothelial Cell Release of Complement-Activating Microparticles

PubMed Central

Renner, Brandon; Klawitter, Jelena; Goldberg, Ryan; McCullough, James W.; Ferreira, Viviana P.; Cooper, James E.; Christians, Uwe

2013-01-01

Defective control of the alternative pathway of complement is an important risk factor for several renal diseases, including atypical hemolytic uremic syndrome. Infections, drugs, pregnancy, and hemodynamic insults can trigger episodes of atypical hemolytic uremic syndrome in susceptible patients. Although the mechanisms linking these clinical events with disease flares are unknown, recent work has revealed that each of these clinical conditions causes cells to release microparticles. We hypothesized that microparticles released from injured endothelial cells promote intrarenal complement activation. Calcineurin inhibitors cause vascular and renal injury and can trigger hemolytic uremic syndrome. Here, we show that endothelial cells exposed to cyclosporine in vitro and in vivo release microparticles that activate the alternative pathway of complement. Cyclosporine-induced microparticles caused injury to bystander endothelial cells and are associated with complement-mediated injury of the kidneys and vasculature in cyclosporine-treated mice. Cyclosporine-induced microparticles did not bind factor H, an alternative pathway regulatory protein present in plasma, explaining their complement-activating phenotype. Finally, we found that in renal transplant patients, the number of endothelial microparticles in plasma increases 2 weeks after starting tacrolimus, and treatment with tacrolimus associated with increased C3 deposition on endothelial microparticles in the plasma of some patients. These results suggest that injury-associated release of endothelial microparticles is an important mechanism by which systemic insults trigger intravascular complement activation and complement-dependent renal diseases. PMID:24092930

Complement activation promotes muscle inflammation during modified muscle use

NASA Technical Reports Server (NTRS)

Frenette, J.; Cai, B.; Tidball, J. G.

2000-01-01

Modified muscle use can result in muscle inflammation that is triggered by unidentified events. In the present investigation, we tested whether the activation of the complement system is a component of muscle inflammation that results from changes in muscle loading. Modified rat hindlimb muscle loading was achieved by removing weight-bearing from the hindlimbs for 10 days followed by reloading through normal ambulation. Experimental animals were injected with the recombinant, soluble complement receptor sCR1 to inhibit complement activation. Assays for complement C4 or factor B in sera showed that sCR1 produced large reductions in the capacity for activation of the complement system through both the classical and alternative pathways. Analysis of complement C4 concentration in serum in untreated animals showed that the classical pathway was activated during the first 2 hours of reloading. Analysis of factor B concentration in untreated animals showed activation of the alternative pathway at 6 hours of reloading. Administration of sCR1 significantly attenuated the invasion of neutrophils (-49%) and ED1(+) macrophages (-52%) that occurred in nontreated animals after 6 hours of reloading. The presence of sCR1 also reduced significantly the degree of edema by 22% as compared to untreated animals. Together, these data show that increased muscle loading activated the complement system which then briefly contributes to the early recruitment of inflammatory cells during modified muscle loading.

Complement activation by carbon nanotubes and its influence on the phagocytosis and cytokine response by macrophages.

PubMed

Pondman, Kirsten M; Sobik, Martin; Nayak, Annapurna; Tsolaki, Anthony G; Jäkel, Anne; Flahaut, Emmanuel; Hampel, Silke; Ten Haken, Bennie; Sim, Robert B; Kishore, Uday

2014-08-01

Carbon nanotubes (CNTs) have promised a range of applications in biomedicine. Although influenced by the dispersants used, CNTs are recognized by the innate immune system, predominantly by the classical pathway of the complement system. Here, we confirm that complement activation by the CNT used continues up to C3 and C5, indicating that the entire complement system is activated including the formation of membrane-attack complexes. Using recombinant forms of the globular regions of human C1q (gC1q) as inhibitors of CNT-mediated classical pathway activation, we show that C1q, the first recognition subcomponent of the classical pathway, binds CNTs via the gC1q domain. Complement opsonisation of CNTs significantly enhances their uptake by U937 cells, with concomitant downregulation of pro-inflammatory cytokines and up-regulation of anti-inflammatory cytokines in both U937 cells and human monocytes. We propose that CNT-mediated complement activation may cause recruitment of cellular infiltration, followed by phagocytosis without inducing a pro-inflammatory immune response. This study highlights the importance of the complement system in response to carbon nanontube administration, suggesting that the ensuing complement activation may cause recruitment of cellular infiltration, followed by phagocytosis without inducing a pro-inflammatory immune response. Copyright © 2014 Elsevier Inc. All rights reserved.

Role of different pathways of the complement cascade in experimental bullous pemphigoid

PubMed Central

Nelson, Kelly C.; Zhao, Minglang; Schroeder, Pamela R.; Li, Ning; Wetsel, Rick A.; Diaz, Luis A.; Liu, Zhi

2006-01-01

Bullous pemphigoid (BP) is an autoimmune subepidermal blistering disease associated with autoantibodies directed against the hemidesmosomal proteins BP180 and BP230 and inflammation. Passive transfer of antibodies to the murine BP180 (mBP180) induces a skin disease that closely resembles human BP. In the present study, we defined the roles of the different complement activation pathways in this model system. Mice deficient in the alternative pathway component factor B (Fb) and injected with pathogenic anti-mBP180 IgG developed delayed and less intense subepidermal blisters. Mice deficient in the classical pathway component complement component 4 (C4) and WT mice pretreated with neutralizing antibody against the first component of the classical pathway, C1q, were resistant to experimental BP. These mice exhibited a significantly reduced level of mast cell degranulation and polymorphonuclear neutrophil (PMN) infiltration in the skin. Intradermal administration of compound 48/80, a mast cell degranulating agent, restored BP disease in C4–/– mice. Furthermore, C4–/– mice became susceptible to experimental BP after local injection of PMN chemoattractant IL-8 or local reconstitution with PMNs. These findings provide the first direct evidence to our knowledge that complement activation via the classical and alternative pathways is crucial in subepidermal blister formation in experimental BP. PMID:17024247

Molecular Pathways: Disrupting polyamine homeostasis as a therapeutic strategy for neuroblastoma

PubMed Central

Evageliou, Nicholas F.; Hogarty, Michael D.

2009-01-01

MYC genes are deregulated in a plurality of human cancers. Through direct and indirect mechanisms the MYC network regulates the expression of >15% of the human genome, including both protein-coding and non-coding RNAs. This complexity has complicated efforts to define the principal pathways mediating MYC’s oncogenic activity. MYC plays a central role providing for the bioenergetic and biomass needs of proliferating cells, and polyamines are essential cell constituents supporting many of these functions. The rate-limiting enzyme in polyamine biosynthesis, ODC, is a bona fide MYC target, as are other regulatory enzymes in this pathway. A wealth of data link enhanced polyamine biosynthesis to cancer progression, and polyamine-depletion may limit malignant transformation of pre-neoplastic lesions. Studies using transgenic cancer models also supports that the effect of MYC on tumor initiation and progression can be attenuated through repression of polyamine production. High-risk neuroblastomas (an often lethal embryonal tumor in which MYC activation is paramount) deregulate numerous polyamine enzymes to promote expansion of intracellular polyamine pools. Selective inhibition of key enzymes in this pathway, e.g., using DFMO and/or SAM486, reduces tumorigenesis and synergizes with chemotherapy to regress tumors in pre-clinical models. Here we review the potential clinical application of these and additional polyamine-depletion agents to neuroblastoma and other advanced cancers in which MYC is operative. PMID:19789308

Deregulation of the COP9 signalosome-cullin-RING ubiquitin-ligase pathway: mechanisms and roles in urological cancers.

PubMed

Gummlich, Linda; Rabien, Anja; Jung, Klaus; Dubiel, Wolfgang

2013-07-01

The COP9 signalosome (CSN)-cullin-RING ubiquitin (Ub)-ligase (CRL) pathway is a prominent segment of the Ub proteasome system (UPS). It specifically ubiquitinates proteins and targets them for proteolytic elimination. As part of the UPS it maintains essential cellular processes including cell cycle progression, DNA repair, antigen processing and signal transduction. The CSN-CRL pathway consists of the CSN possessing eight subunits (CSN1-CSN8) and one CRL consisting of a cullin, a RING-domain protein and a substrate recognition subunit (SRS). In human cells approximately 250 CRLs exist each of which interacting with a specific set of substrates and the CSN. The CSN-CRL interplay determines the activity and specificity of CRL ubiquitination. The removal of the Ub-like protein Nedd8 from the CRL component cullin by the CSN (deneddylation) reduces the ubiquitinating activity and at the same time enables reassembly of CRLs in order to adapt to substrate specificity requirements. On the other hand, CRLs as well as substrates negatively influence the deneddylating activity of the CSN. In recent years evidence accumulated that deregulation of the CSN-CRL pathway can cause cancer. Here we review current knowledge on modifications of CSN and CRL components including CSN subunits, SRSs and cullins causing tumorigenesis with emphasis on urological neoplasia. The CSN-CRL pathway is a target of tumor-viruses as well as of a multitude of miRNAs. Recently evaluated miRNAs altered in urological cancers might have impact on the CSN-CRL pathway which has to be analyzed in future experiments. We propose that the pathway is a suitable target for future tumor therapy. Copyright © 2013 Elsevier Ltd. All rights reserved.

Inhibitor(s) of the classical complement pathway in mouse serum limit the utility of mice as experimental models of neuromyelitis optica.

PubMed

Ratelade, Julien; Verkman, A S

2014-11-01

Neuromyelitis optica (NMO) is an inflammatory demyelinating disease of the central nervous system in which anti-aquaporin-4 (AQP4) autoantibodies (AQP4-IgG) cause damage to astrocytes by complement-dependent cytotoxicity (CDC). Various approaches have been attempted to produce NMO lesions in rodents, some involving genetically modified mice with altered immune cell function. Here, we found that mouse serum strongly inhibits complement from multiple species, preventing AQP4-IgG-dependent CDC. Effects of mouse serum on complement activation were tested in CDC assays in which AQP4-expressing cells were incubated with AQP4-IgG and complement from different species. Biochemical assays and mass spectrometry were used to characterize complement inhibitor(s) in mouse serum. Sera from different strains of mice produced almost no AQP4-IgG-dependent CDC compared with human, rat and guinea pig sera. Remarkably, addition of mouse serum prevented AQP4-IgG-dependent CDC caused by human, rat or guinea pig serum, with 50% inhibition at <5% mouse serum. Hemolysis assays indicated that the inhibitor(s) in mouse serum target the classical and not the alternative complement pathway. We found that the complement inhibitor(s) in mouse serum were contained in a serum fraction purified with protein-A resin; however, the inhibitor was not IgG as determined using serum from IgG-deficient mice. Mass spectrometry on the protein A-purified fraction produced several inhibitor candidates. The low intrinsic complement activity of mouse serum and the presence of complement inhibitor(s) limit the utility of mouse models to study disorders, such as NMO, involving the classical complement pathway. Copyright © 2014 Elsevier Ltd. All rights reserved.

Human Tamm-Horsfall protein, a renal specific protein, serves as a cofactor in complement 3b degradation

PubMed Central

2017-01-01

Tamm-Horsfall protein (THP) is an abundant urinary protein of renal origin. We hypothesize that THP can act as an inhibitor of complement since THP binds complement 1q (C1q) of the classical complement pathway, inhibits activation of this pathway, and is important in decreasing renal ischemia-reperfusion injury (a complement-mediated condition). In this study, we began to investigate whether THP interacted with the alternate complement pathway via complement factor H (CFH). THP was shown to bind CFH using ligand blots and in an ELISA (KD of 1 × 10−6 M). Next, the ability of THP to alter CFH’s normal action as it functioned as a cofactor in complement factor I (CFI)–mediated complement 3b (C3b) degradation was investigated. Unexpectedly, control experiments in these in vitro assays suggested that THP, without added CFH, could act as a cofactor in CFI-mediated C3b degradation. This cofactor activity was present equally in THP isolated from 10 different individuals. While an ELISA demonstrated small amounts of CFH contaminating THP samples, these CFH amounts were insufficient to explain the degree of cofactor activity present in THP. An ELISA demonstrated that THP directly bound C3b (KD ~ 5 × 10−8 m), a prerequisite for a protein acting as a C3b degradation cofactor. The cofactor activity of THP likely resides in the protein portion of THP since partially deglycosylated THP still retained cofactor activity. In conclusion, THP appears to participate directly in complement inactivation by its ability to act as a cofactor for C3b degradation, thus adding support to the hypothesis that THP might act as an endogenous urinary tract inhibitor of complement. PMID:28742158

Cell-derived microparticles and complement activation in preeclampsia versus normal pregnancy.

PubMed

Biró, E; Lok, C A R; Hack, C E; van der Post, J A M; Schaap, M C L; Sturk, A; Nieuwland, R

2007-01-01

Inflammation plays a major role in the vascular dysfunction seen in preeclampsia, and several studies suggest involvement of the complement system. To investigate whether complement activation on the surface of microparticles is increased in plasma of preeclamptic patients versus healthy pregnant controls. Microparticles from plasma of preeclamptic (n=10), healthy pregnant (n=10) and healthy nonpregnant (n=10) women were analyzed by flow cytometry for bound complement components (C1q, C4, C3) and complement activator molecules (C-reactive protein [CRP], serum amyloid P component [SAP], immunoglobulin [Ig]M, IgG). Fluid phase complement activation products and activator molecules were also determined. Levels of microparticles with bound complement components showed no increase in complement activation on the microparticle surface in preeclamptic women, in line with levels of fluid phase complement activation products. In healthy nonpregnant and pregnant women, bound CRP was associated with classical pathway activation on the microparticle surface, and in healthy pregnant women IgM and IgG molecules also contributed. In preeclamptic women, microparticles with bound SAP and those with IgG seemed to contribute to C1q binding without a clear association to further classical pathway activation. Furthermore, significantly increased levels of microparticles with bound CRP were present in preeclamptic compared with healthy pregnant women (median 178x10(6)/L versus 47x10(6)/L, P<0.01), but without concomitant increases in complement activation. We found no evidence of increased complement activation on the microparticle surface in preeclamptic women. Microparticles with bound CRP were significantly increased, but in contrast to healthy pregnant and nonpregnant women, this was not associated with increased classical pathway activation on the surface of the microparticles.

Genetic evidence for involvement of classical complement pathway in induction of experimental autoimmune myasthenia gravis.

PubMed

Tüzün, Erdem; Scott, Benjamin G; Goluszko, Elzbieta; Higgs, Stephen; Christadoss, Premkumar

2003-10-01

Abs to acetylcholine receptor (AChR) and complement are the major constituents of pathogenic events causing neuromuscular junction destruction in both myasthenia gravis (MG) and experimental autoimmune MG (EAMG). To analyze the differential roles of the classical vs alternative complement pathways in EAMG induction, we immunized C3(-/-), C4(-/-), C3(+/-), and C4(+/-) mice and their control littermates (C3(+/+) and C4(+/+) mice) with AChR in CFA. C3(-/-) and C4(-/-) mice were resistant to disease, whereas mice heterozygous for C3 or C4 displayed intermediate susceptibility. Although C3(-/-) and C4(-/-) mice had anti-AChR Abs in their sera, anti-AChR IgG production by C3(-/-) mice was significantly suppressed. Both C3(-/-) and C4(-/-) mice had reduced levels of B cells and increased expression of apoptotis inducers (Fas ligand, CD69) and apoptotic cells in lymph nodes. Immunofluorescence studies showed that the neuromuscular junction of C3(-/-) and C4(-/-) mice lacked C3 or membrane attack complex deposits, despite having IgG deposits, thus providing in vivo evidence for the incapacity of anti-AChR IgGs to induce full-blown EAMG without the aid of complements. The data provide the first direct genetic evidence for the classical complement pathway in the induction of EAMG induced by AChR immunization. Accordingly, severe MG and other Ab- and complement-mediated diseases could be effectively treated by inhibiting C4, thus leaving the alternative complement pathway intact.

Systemic Lupus Erythematosus and Deficiencies of Early Components of the Complement Classical Pathway

PubMed Central

Macedo, Ana Catarina Lunz; Isaac, Lourdes

2016-01-01

The complement system plays an important role in the innate and acquired immune response against pathogens. It consists of more than 30 proteins found in soluble form or attached to cell membranes. Most complement proteins circulate in inactive forms and can be sequentially activated by the classical, alternative, or lectin pathways. Biological functions, such as opsonization, removal of apoptotic cells, adjuvant function, activation of B lymphocytes, degranulation of mast cells and basophils, and solubilization and clearance of immune complex and cell lysis, are dependent on complement activation. Although the activation of the complement system is important to avoid infections, it also can contribute to the inflammatory response triggered by immune complex deposition in tissues in autoimmune diseases. Paradoxically, the deficiency of early complement proteins from the classical pathway (CP) is strongly associated with development of systemic lupus erythematous (SLE) – mainly C1q deficiency (93%) and C4 deficiency (75%). The aim of this review is to focus on the deficiencies of early components of the CP (C1q, C1r, C1s, C4, and C2) proteins in SLE patients. PMID:26941740

Capturing the biological impact of CDKN2A and MC1R genes as an early predisposing event in melanoma and non melanoma skin cancer

PubMed Central

Puig-Butille, Joan Anton; Escámez, María José; Garcia-Garcia, Francisco; Tell-Marti, Gemma; Fabra, Àngels; Martínez-Santamaría, Lucía; Badenas, Celia; Aguilera, Paula; Pevida, Marta; Dopazo, Joaquín; del Río, Marcela; Puig, Susana

2014-01-01

Germline mutations in CDKN2A and/or red hair color variants in MC1R genes are associated with an increased susceptibility to develop cutaneous melanoma or non melanoma skin cancer. We studied the impact of the CDKN2A germinal mutation p.G101W and MC1R variants on gene expression and transcription profiles associated with skin cancer. To this end we set-up primary skin cell co-cultures from siblings of melanoma prone-families that were later analyzed using the expression array approach. As a result, we found that 1535 transcripts were deregulated in CDKN2A mutated cells, with over-expression of immunity-related genes (HLA-DPB1, CLEC2B, IFI44, IFI44L, IFI27, IFIT1, IFIT2, SP110 and IFNK) and down-regulation of genes playing a role in the Notch signaling pathway. 3570 transcripts were deregulated in MC1R variant carriers. In particular, genes related to oxidative stress and DNA damage pathways were up-regulated as well as genes associated with neurodegenerative diseases such as Parkinson’s, Alzheimer and Huntington. Finally, we observed that the expression signatures indentified in phenotypically normal cells carrying CDKN2A mutations or MC1R variants are maintained in skin cancer tumors (melanoma and squamous cell carcinoma). These results indicate that transcriptome deregulation represents an early event critical for skin cancer development. PMID:24742402

An ecoimmunological approach to study evolutionary and ancient links between coagulation, complement and Innate immunity

PubMed Central

Kasetty, Gopinath; Alyafei, Saud; Smeds, Emanuel; Salo-Ahen, Outi M. H.; Hansson, Stefan R.; Egesten, Arne; Herwald, Heiko

2018-01-01

ABSTRACT Coagulation, complement, and innate immunity are tightly interwoven and form an alliance that can be traced back to early eukaryotic evolution. Here we employed an ecoimmunological approach using Tissue Factor Pathway Inhibitor (TFPI)-1-derived peptides from the different classes of vertebrates (i.e. fish, reptile, bird, and mammals) and tested whether they can boost killing of various human bacterial pathogens in plasma. We found signs of species-specific conservation and diversification during evolution in these peptides that significantly impact their antibacterial activity. Though all peptides tested executed bactericidal activity in mammalian plasma (with the exception of rodents), no killing was observed in plasma from birds, reptiles, and fish, pointing to a crucial role for the classical pathway of the complement system. We also observed an interference of these peptides with the human intrinsic pathway of coagulation though, unlike complement activation, this mechanism appears not to be evolutionary conserved. PMID:29473457

Sex-specific patterns and deregulation of endocrine pathways in the gene expression profiles of Bangladeshi adults exposed to arsenic contaminated drinking water

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muñoz, Alexandra; Chervona, Yana; Hall, Megan

Arsenic contamination of drinking water occurs globally and is associated with numerous diseases including skin, lung and bladder cancers, and cardiovascular disease. Recent research indicates that arsenic may be an endocrine disruptor. This study was conducted to evaluate the nature of gene expression changes among males and females exposed to arsenic contaminated water in Bangladesh at high and low doses. Twenty-nine (55% male) Bangladeshi adults with water arsenic exposure ranging from 50 to 1000 μg/L were selected from the Folic Acid Creatinine Trial. RNA was extracted from peripheral blood mononuclear cells for gene expression profiling using Affymetrix 1.0 ST arrays.more » Differentially expressed genes were assessed between high and low exposure groups for males and females separately and findings were validated using quantitative real-time PCR. There were 534 and 645 differentially expressed genes (p < 0.05) in the peripheral blood mononuclear cells of males and females, respectively, when high and low water arsenic exposure groups were compared. Only 43 genes overlapped between the two sexes, with 29 changing in opposite directions. Despite the difference in gene sets both males and females exhibited common biological changes including deregulation of 17β-hydroxysteroid dehydrogenase enzymes, deregulation of genes downstream of Sp1 (specificity protein 1) transcription factor, and prediction of estrogen receptor alpha as a key hub in cardiovascular networks. Arsenic-exposed adults exhibit sex-specific gene expression profiles that implicate involvement of the endocrine system. Due to arsenic's possible role as an endocrine disruptor, exposure thresholds for arsenic may require different parameters for males and females. - Highlights: • Males and females exhibit unique gene expression changes in response to arsenic. • Only 23 genes are common among the differentially expressed genes for the sexes. • Male and female gene lists exhibit common biological implications. • Both sexes exhibit deregulation of cardiovascular and endocrine pathways.« less

The lectin pathway in renal disease: old concept and new insights.

PubMed

Gaya da Costa, Mariana; Poppelaars, Felix; Berger, Stefan P; Daha, Mohamed R; Seelen, Marc A

2018-04-26

The complement system is composed of a network of at least 40 proteins, which significantly contributes to health and disease. The lectin pathway (LP) is one of three pathways that can activate the complement system. Next to protection of the host against pathogens, the LP has been shown to play a crucial role in multiple renal diseases as well as during renal replacement therapy. Therefore, several complement-targeted drugs are currently being explored in clinical trials. Among these complement inhibitors, specific LP inhibitors are also being tested in renal abnormalities such as in immunoglobulin A nephropathy and lupus nephritis. Using various in vitro models, Yaseen et al. (Lectin pathway effector enzyme mannan-binding lectin-associated serine protease-2 can activate native complement component 3 (C3) in absence of C4 and/or C2. FASEB J 2017; 31: 2210-2219) showed that Mannan-associated serine protease2 can directly activate C3 thereby bypassing C2 and C4 in the activation of the LP. These new findings broaden our understanding of the mechanisms of complement activation and could potentially impact our strategies to inhibit the LP in renal diseases. In support of these findings, we present data of human renal biopsies, demonstrating the occurrence of the LP bypass mechanism in vivo. In conclusion, this review provides a detailed overview of the LP and clarifies the recently described bypass mechanism and its relevance. Finally, we speculate on the role of the C4 bypass mechanism in other renal diseases.

Determinism and Contingency Shape Metabolic Complementation in an Endosymbiotic Consortium

PubMed Central

Ponce-de-Leon, Miguel; Tamarit, Daniel; Calle-Espinosa, Jorge; Mori, Matteo; Latorre, Amparo; Montero, Francisco; Pereto, Juli

2017-01-01

Bacterial endosymbionts and their insect hosts establish an intimate metabolic relationship. Bacteria offer a variety of essential nutrients to their hosts, whereas insect cells provide the necessary sources of matter and energy to their tiny metabolic allies. These nutritional complementations sustain themselves on a diversity of metabolite exchanges between the cell host and the reduced yet highly specialized bacterial metabolism—which, for instance, overproduces a small set of essential amino acids and vitamins. A well-known case of metabolic complementation is provided by the cedar aphid Cinara cedri that harbors two co-primary endosymbionts, Buchnera aphidicola BCc and Ca. Serratia symbiotica SCc, and in which some metabolic pathways are partitioned between different partners. Here we present a genome-scale metabolic network (GEM) for the bacterial consortium from the cedar aphid iBSCc. The analysis of this GEM allows us the confirmation of cases of metabolic complementation previously described by genome analysis (i.e., tryptophan and biotin biosynthesis) and the redefinition of an event of metabolic pathway sharing between the two endosymbionts, namely the biosynthesis of tetrahydrofolate. In silico knock-out experiments with iBSCc showed that the consortium metabolism is a highly integrated yet fragile network. We also have explored the evolutionary pathways leading to the emergence of metabolic complementation between reduced metabolisms starting from individual, complete networks. Our results suggest that, during the establishment of metabolic complementation in endosymbionts, adaptive evolution is significant in the case of tryptophan biosynthesis, whereas vitamin production pathways seem to adopt suboptimal solutions. PMID:29213256

Determinism and Contingency Shape Metabolic Complementation in an Endosymbiotic Consortium.

PubMed

Ponce-de-Leon, Miguel; Tamarit, Daniel; Calle-Espinosa, Jorge; Mori, Matteo; Latorre, Amparo; Montero, Francisco; Pereto, Juli

2017-01-01

Bacterial endosymbionts and their insect hosts establish an intimate metabolic relationship. Bacteria offer a variety of essential nutrients to their hosts, whereas insect cells provide the necessary sources of matter and energy to their tiny metabolic allies. These nutritional complementations sustain themselves on a diversity of metabolite exchanges between the cell host and the reduced yet highly specialized bacterial metabolism-which, for instance, overproduces a small set of essential amino acids and vitamins. A well-known case of metabolic complementation is provided by the cedar aphid Cinara cedri that harbors two co-primary endosymbionts, Buchnera aphidicola BCc and Ca . Serratia symbiotica SCc, and in which some metabolic pathways are partitioned between different partners. Here we present a genome-scale metabolic network (GEM) for the bacterial consortium from the cedar aphid i BSCc. The analysis of this GEM allows us the confirmation of cases of metabolic complementation previously described by genome analysis (i.e., tryptophan and biotin biosynthesis) and the redefinition of an event of metabolic pathway sharing between the two endosymbionts, namely the biosynthesis of tetrahydrofolate. In silico knock-out experiments with i BSCc showed that the consortium metabolism is a highly integrated yet fragile network. We also have explored the evolutionary pathways leading to the emergence of metabolic complementation between reduced metabolisms starting from individual, complete networks. Our results suggest that, during the establishment of metabolic complementation in endosymbionts, adaptive evolution is significant in the case of tryptophan biosynthesis, whereas vitamin production pathways seem to adopt suboptimal solutions.

Complement is activated in progressive multiple sclerosis cortical grey matter lesions.

PubMed

Watkins, Lewis M; Neal, James W; Loveless, Sam; Michailidou, Iliana; Ramaglia, Valeria; Rees, Mark I; Reynolds, Richard; Robertson, Neil P; Morgan, B Paul; Howell, Owain W

2016-06-22

The symptoms of multiple sclerosis (MS) are caused by damage to myelin and nerve cells in the brain and spinal cord. Inflammation is tightly linked with neurodegeneration, and it is the accumulation of neurodegeneration that underlies increasing neurological disability in progressive MS. Determining pathological mechanisms at play in MS grey matter is therefore a key to our understanding of disease progression. We analysed complement expression and activation by immunocytochemistry and in situ hybridisation in frozen or formalin-fixed paraffin-embedded post-mortem tissue blocks from 22 progressive MS cases and made comparisons to inflammatory central nervous system disease and non-neurological disease controls. Expression of the transcript for C1qA was noted in neurons and the activation fragment and opsonin C3b-labelled neurons and glia in the MS cortical and deep grey matter. The density of immunostained cells positive for the classical complement pathway protein C1q and the alternative complement pathway activation fragment Bb was significantly increased in cortical grey matter lesions in comparison to control grey matter. The number of cells immunostained for the membrane attack complex was elevated in cortical lesions, indicating complement activation to completion. The numbers of classical (C1-inhibitor) and alternative (factor H) pathway regulator-positive cells were unchanged between MS and controls, whilst complement anaphylatoxin receptor-bearing microglia in the MS cortex were found closely apposed to cortical neurons. Complement immunopositive neurons displayed an altered nuclear morphology, indicative of cell stress/damage, supporting our finding of significant neurodegeneration in cortical grey matter lesions. Complement is activated in the MS cortical grey matter lesions in areas of elevated numbers of complement receptor-positive microglia and suggests that complement over-activation may contribute to the worsening pathology that underlies the irreversible progression of MS.

Alternative Splicing in the Hippo Pathway—Implications for Disease and Potential Therapeutic Targets

PubMed Central

Porazinski, Sean; Ladomery, Michael

2018-01-01

Alternative splicing is a well-studied gene regulatory mechanism that produces biological diversity by allowing the production of multiple protein isoforms from a single gene. An involvement of alternative splicing in the key biological signalling Hippo pathway is emerging and offers new therapeutic avenues. This review discusses examples of alternative splicing in the Hippo pathway, how deregulation of these processes may contribute to disease and whether these processes offer new potential therapeutic targets. PMID:29534050

Complement in Non-Antibody-Mediated Kidney Diseases

PubMed Central

Angeletti, Andrea; Reyes-Bahamonde, Joselyn; Cravedi, Paolo; Campbell, Kirk N.

2017-01-01

The complement system is part of the innate immune response that plays important roles in protecting the host from foreign pathogens. The complement components and relative fragment deposition have long been recognized to be strongly involved also in the pathogenesis of autoantibody-related kidney glomerulopathies, leading to direct glomerular injury and recruitment of infiltrating inflammation pathways. More recently, unregulated complement activation has been shown to be associated with progression of non-antibody-mediated kidney diseases, including focal segmental glomerulosclerosis, C3 glomerular disease, thrombotic microangiopathies, or general fibrosis generation in progressive chronic kidney diseases. Some of the specific mechanisms associated with complement activation in these diseases were recently clarified, showing a dominant role of alternative activation pathway. Over the last decade, a growing number of anticomplement agents have been developed, and some of them are being approved for clinical use or already in use. Therefore, anticomplement therapies represent a realistic choice of therapeutic approaches for complement-related diseases. Herein, we review the complement system activation, regulatory mechanisms, their involvement in non-antibody-mediated glomerular diseases, and the recent advances in complement-targeting agents as potential therapeutic strategies. PMID:28748184

Modulation of post-stroke degenerative and regenerative processes and subacute protection by site-targeted inhibition of the alternative pathway of complement.

PubMed

Alawieh, Ali; Elvington, Andrew; Zhu, Hong; Yu, Jin; Kindy, Mark S; Atkinson, Carl; Tomlinson, Stephen

2015-12-30

Complement promotes neuroinflammation and injury in models of stroke. However, complement is also being increasingly implicated in repair and regeneration after central nervous system (CNS) injury, and some complement deficiencies have been shown to provide acute, but not subacute, protection after murine stroke. Here, we investigate the dual role of complement in injury and repair after cerebral ischemia and reperfusion. We used complement-deficient mice and different complement inhibitors in a model of transient middle cerebral artery occlusion to investigate complement-dependent cellular and molecular changes that occur through the subacute phase after stroke. C3 deficiency and site-targeted complement inhibition with either CR2-Crry (inhibits all pathways) or CR2-fH (inhibits alternative pathway) significantly reduced infarct size, reduced apoptotic cell death, and improved neurological deficit score in the acute phase after stroke. However, only in CR2-fH-treated mice was there sustained protection with no evolution of injury in the subacute phase. Whereas both inhibitors significantly reduced microglia/macrophage activation and astrogliosis in the subacute phase, only CR2-fH improved neurological deficit and locomotor function, maintained neurogenesis markers, enhanced neuronal migration, and increased VEGF expression. These findings in CR2-fH-treated mice correlated with improved performance in spatial learning and passive avoidance tasks. The complement anaphylatoxins have been implicated in repair and regenerative mechanisms after CNS injury, and in this context CR2-fH significantly reduced, but did not eliminate the generation of C5a within the brain, unlike CR2-Crry that completely blocked C5a generation. Gene expression profiling revealed that CR2-fH treatment downregulated genes associated with apoptosis, TGFβ signaling, and neutrophil activation, and decreased neutrophil infiltration was confirmed by immunohistochemistry. CR2-fH upregulated genes for neural growth factor and mediators of neurogenesis and neuronal migration. Live animal imaging demonstrated that following intravenous injection, CR2-fH targeted specifically to the post-ischemic brain, with a tissue half-life of 48.5 h. Finally, unlike C3 deficiency, targeted complement inhibition did not increase susceptibility to lethal post-stroke infection, an important consideration for stroke patients. Ischemic brain tissue-targeted and selective inhibition of alternative complement pathway provide self-limiting inhibition of complement activation and reduces acute injury while maintaining complement-dependent recovery mechanisms into the subacute phase after stroke.

A Systematic Study of Dysregulated MicroRNA in Type 2 Diabetes Mellitus.

PubMed

He, Yuqing; Ding, Yuanlin; Liang, Biyu; Lin, Juanjuan; Kim, Taek-Kyun; Yu, Haibing; Hang, Hanwei; Wang, Kai

2017-02-28

MicroRNAs (miRNAs) are small noncoding RNAs that modulate the cellular transcriptome at the post-transcriptional level. miRNA plays important roles in different disease manifestation, including type 2 diabetes mellitus (T2DM). Many studies have characterized the changes of miRNAs in T2DM, a complex systematic disease; however, few studies have integrated these findings and explored the functional effects of the dysregulated miRNAs identified. To investigate the involvement of miRNAs in T2DM, we obtained and analyzed all relevant studies published prior to 18 October 2016 from various literature databases. From 59 independent studies that met the inclusion criteria, we identified 158 dysregulated miRNAs in seven different major sample types. To understand the functional impact of these deregulated miRNAs, we performed targets prediction and pathway enrichment analysis. Results from our analysis suggested that the altered miRNAs are involved in the core processes associated with T2DM, such as carbohydrate and lipid metabolisms, insulin signaling pathway and the adipocytokine signaling pathway. This systematic survey of dysregulated miRNAs provides molecular insights on the effect of deregulated miRNAs in different tissues during the development of diabetes. Some of these miRNAs and their mRNA targets may have diagnostic and/or therapeutic utilities in T2DM.

Aberrant Retinoblastoma (RB)-E2F Transcriptional Regulation Defines Molecular Phenotypes of Osteosarcoma*

PubMed Central

Scott, Milcah C.; Sarver, Aaron L.; Tomiyasu, Hirotaka; Cornax, Ingrid; Van Etten, Jamie; Varshney, Jyotika; O'Sullivan, M. Gerard; Subramanian, Subbaya; Modiano, Jaime F.

2015-01-01

We previously identified two distinct molecular subtypes of osteosarcoma through gene expression profiling. These subtypes are associated with distinct tumor behavior and clinical outcomes. Here, we describe mechanisms that give rise to these molecular subtypes. Using bioinformatic analyses, we identified a significant association between deregulation of the retinoblastoma (RB)-E2F pathway and the molecular subtype with worse clinical outcomes. Xenotransplantation models recapitulated the corresponding behavior for each osteosarcoma subtype; thus, we used cell lines to validate the role of the RB-E2F pathway in regulating the prognostic gene signature. Ectopic RB resets the patterns of E2F regulated gene expression in cells derived from tumors with worse clinical outcomes (molecular phenotype 2) to those comparable with those observed in cells derived from tumors with less aggressive outcomes (molecular phenotype 1), providing a functional association between RB-E2F dysfunction and altered gene expression in osteosarcoma. DNA methyltransferase and histone deacetylase inhibitors similarly reset the transcriptional state of the molecular phenotype 2 cells from a state associated with RB deficiency to one seen with RB sufficiency. Our data indicate that deregulation of RB-E2F pathway alters the epigenetic landscape and biological behavior of osteosarcoma. PMID:26378234

The crossroads of breast cancer progression: insights into the modulation of major signaling pathways

PubMed Central

Farias, Jessica O; Torres, Nadia EC; Ferruzo, Pault YM; Anschau, Valesca; Jesus-Ferreira, Henrique C; Chang, Ted Hung-Tse; Sogayar, Mari Cleide; Zerbini, Luiz F; Correa, Ricardo G

2017-01-01

Cancer is the disease with highest public health impact in developed countries. Particularly, breast cancer has the highest incidence in women worldwide and the fifth highest mortality in the globe, imposing a significant social and economic burden to society. The disease has a complex heterogeneous etiology, being associated with several risk factors that range from lifestyle to age and family history. Breast cancer is usually classified according to the site of tumor occurrence and gene expression profiling. Although mutations in a few key genes, such as BRCA1 and BRCA2, are associated with high breast cancer risk, the large majority of breast cancer cases are related to mutated genes of low penetrance, which are frequently altered in the whole population. Therefore, understanding the molecular basis of breast cancer, including the several deregulated genes and related pathways linked to this pathology, is essential to ensure advances in early tumor detection and prevention. In this review, we outline key cellular pathways whose deregulation has been associated with breast cancer, leading to alterations in cell proliferation, apoptosis, and the delicate hormonal balance of breast tissue cells. Therefore, here we describe some potential breast cancer-related nodes and signaling concepts linked to the disease, which can be positively translated into novel therapeutic approaches and predictive biomarkers. PMID:29200866

Activated complement components and complement activator molecules on the surface of cell‐derived microparticles in patients with rheumatoid arthritis and healthy individuals

PubMed Central

Biró, Éva; Nieuwland, Rienk; Tak, Paul P; Pronk, Loes M; Schaap, Marianne C L; Sturk, Augueste; Hack, C Erik

2007-01-01

Objectives In vitro, microparticles can activate complement via the classical pathway. If demonstrable ex vivo, this mechanism may contribute to the pathogenesis of rheumatoid arthritis (RA). We therefore investigated the presence of activated complement components and complement activator molecules on the surface of cell‐derived microparticles of RA patients and healthy individuals. Methods Microparticles from synovial fluid (n = 8) and plasma (n = 9) of 10 RA patients and plasma of sex‐ and age‐matched healthy individuals (n = 10) were analysed by flow cytometry for bound complement components (C1q, C4, C3) and complement activator molecules (C‐reactive protein (CRP), serum amyloid P component (SAP), immunoglobulin (Ig) M, IgG). Results Microparticles with bound C1q, C4, and/or C3 were abundant in RA synovial fluid, while in RA and control plasma much lower levels were present. Microparticles with bound C1q correlated with those with bound C3 in synovial fluid (r = 0.961, p = 0.0001), and with those with bound C4 in plasma (RA: r = 0.908, p = 0.0007; control: r = 0.632, p = 0.0498), indicating classical pathway activation. In synovial fluid, microparticles with IgM and IgG correlated with those with C1q (r = 0.728, p = 0.0408; r = 0.952, p = 0.0003, respectively), and in plasma, microparticles with CRP correlated with those with C1q (RA: r = 0.903, p = 0.0021; control: r = 0.683, p = 0.0296), implicating IgG and IgM in the classical pathway activation in RA synovial fluid, and CRP in the low level classical pathway activation in plasma. Conclusions This study demonstrates the presence of bound complement components and activator molecules on microparticles ex vivo, and supports their role in low grade complement activation in plasma and increased complement activation in RA synovial fluid. PMID:17261534

Phylogenetic aspects of the complement system.

PubMed

Zarkadis, I K; Mastellos, D; Lambris, J D

2001-01-01

During evolution two general systems of immunity have emerged: innate or, natural immunity and adaptive (acquired), or specific immunity. The innate system is phylogenetically older and is found in some form in all multicellular organisms, whereas the adaptive system appeared about 450 million years ago and is found in all vertebrates except jawless fish. The complement system in higher vertebrates plays an important role as an effector of both the innate and the acquired immune response, and also participates in various immunoregulatory processes. In lower vertebrates complement is activated by the alternative and lectin pathways and is primarily involved in the opsonization of foreign material. The Agnatha (the most primitive vertebrate species) possess the alternative and lectin pathways while cartilaginous fish are the first species in which the classical pathway appears following the emergence of immunoglobulins. The rest of the poikilothermic species, ranging from teleosts to reptilians, appear to contain a well-developed complement system resembling that of the homeothermic vertebrates. It seems that most of the complement components have appeared after the duplication of primordial genes encoding C3/C4/C5, fB/C2, C1s/C1r/MASP-1/MASP-2, and C6/C7/C8/C9 molecules, in a process that led to the formation of distinct activation pathways. However, unlike homeotherms, several species of poikilotherms (e.g. trout) have recently been shown to possess multiple forms of complement components (C3, factor B) that are structurally and functionally more diverse than those of higher vertebrates. We hypothesize that this remarkable diversity has allowed these animals to expand their innate capacity for immune recognition and response. Recent studies have also indicated the possible presence of complement receptors in protochordates and lower vertebrates. In conclusion, there is considerable evidence suggesting that the complement system is present in the entire lineage of deuterostomes, and regulatory complement components have been identified in all species beyond the protochordates, indicating that the mechanisms of complement activation and regulation have developed in parallel.

Transcriptome Analysis of the Innate Immunity-Related Complement System in Spleen Tissue of Ctenopharyngodon idella Infected with Aeromonas hydrophila

PubMed Central

Dang, Yunfei; Xu, Xiaoyan; Shen, Yubang; Hu, Moyan; Zhang, Meng; Li, Lisen; Lv, Liqun; Li, Jiale

2016-01-01

The grass carp (Ctenopharyngodon idella) is an important commercial farmed herbivorous fish species in China, but is susceptible to Aeromonas hydrophila infections. In the present study, we performed de novo RNA-Seq sequencing of spleen tissue from specimens of a disease-resistant family, which were given intra-peritoneal injections containing PBS with or without a dose of A. hydrophila. The fish were sampled from the control group at 0 h, and from the experimental group at 4, 8, 12, 24, 48 and 72 h. 122.18 million clean reads were obtained from the normalized cDNA libraries; these were assembled into 425,260 contigs and then 191,795 transcripts. Of those, 52,668 transcripts were annotated with the NCBI Nr database, and 41,347 of the annotated transcripts were assigned into 90 functional groups. 20,569 unigenes were classified into six main categories, including 38 secondary KEGG pathways. 2,992 unigenes were used in the analysis of differentially expressed genes (DEGs). 89 of the putative DEGs were related to the immune system and 41 of them were involved in the complement and coagulation cascades pathway. This study provides insights into the complement and complement-related pathways involved in innate immunity, through expression profile analysis of the genomic resources in C. idella. We conclude that complement and complement-related genes play important roles during defense against A. hydrophila infection. The immune response is activated at 4 h after the bacterial injections, indicating that the complement pathways are activated at the early stage of bacterial infection. The study has improved our understanding of the immune response mechanisms in C. idella to bacterial pathogens. PMID:27383749

Systemic human CR2-targeted complement alternative pathway inhibitor ameliorates mouse laser-induced choroidal neovascularization.

PubMed

Rohrer, Bärbel; Coughlin, Beth; Bandyopadhyay, Mausumi; Holers, V Michael

2012-08-01

Genetic associations and the presence of complement components within pathological structures of age-related macular degeneration (AMD) have generated the hypothesis that AMD is caused by chronic local complement activation. Since the majority of activity in the common terminal pathway results from engagement of the amplification loop, the alternative pathway has been proposed as a logical therapeutic target. We recently generated a factor H (fH)-based complement inhibitor (CR2-fH) with the capacity to be "targeted" to sites of complement C3 activation. We asked whether the human therapeutic (TT30) is effective in a mouse model of AMD. Choroidal neovascularization (CNV) was induced by argon laser photocoagulation of Bruch's membrane. Every other day, mice received intravenous injections of TT30 or vehicles, and after 6 days, the presence or absence of CNV and CNV-related changes were evaluated. Area of CNV, photoreceptor cell function, gene expression for complement components and cytokines, vascular endothelial growth factor (VEGF) protein levels, and TT30 bioavailability were determined. CNV development, which has previously been shown to require local complement activation, could be reduced by intravenous TT30 delivery. Specific inhibition of the alternative pathway not only reduced angiogenesis in CNV, but also ameliorated changes in several associated disease-related biomarkers, including diminished retinal function and molecular events known to be involved in AMD such as VEGF production. After intravenous injection, TT30 localized to CNV lesion sites in the retinal pigmented epithelium-choroid. Systemic administration of TT30 was found to reduce CNV pathology. These data may open new avenues for novel systemic AMD treatment strategies.

Protection of host cells by complement regulators.

PubMed

Schmidt, Christoph Q; Lambris, John D; Ricklin, Daniel

2016-11-01

The complement cascade is an ancient immune-surveillance system that not only provides protection from pathogen invasion but has also evolved to participate in physiological processes to maintain tissue homeostasis. The alternative pathway (AP) of complement activation is the evolutionarily oldest part of this innate immune cascade. It is unique in that it is continuously activated at a low level and arbitrarily probes foreign, modified-self, and also unaltered self-structures. This indiscriminate activation necessitates the presence of preformed regulators on autologous surfaces to spare self-cells from the undirected nature of AP activation. Although the other two canonical complement activation routes, the classical and lectin pathways, initiate the cascade more specifically through pattern recognition, their activity still needs to be tightly controlled to avoid excessive reactivity. It is the perpetual duty of complement regulators to protect the self from damage inflicted by inadequate complement activation. Here, we review the role of complement regulators as preformed mediators of defense, explain their common and specialized functions, and discuss selected cases in which alterations in complement regulators lead to disease. Finally, rational engineering approaches using natural complement inhibitors as potential therapeutics are highlighted. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Pathways Impacted by Genomic Alterations in Pulmonary Carcinoid Tumors.

PubMed

Asiedu, Michael K; Thomas, Charles F; Dong, Jie; Schulte, Sandra C; Khadka, Prasidda; Sun, Zhifu; Kosari, Farhad; Jen, Jin; Molina, Julian; Vasmatzis, George; Kuang, Ray; Aubry, Marie Christine; Yang, Ping; Wigle, Dennis A

2018-04-01

Purpose: Pulmonary carcinoid tumors account for up to 5% of all lung malignancies in adults, comprise 30% of all carcinoid malignancies, and are defined histologically as typical carcinoid (TC) and atypical carcinoid (AC) tumors. The role of specific genomic alterations in the pathogenesis of pulmonary carcinoid tumors remains poorly understood. We sought to identify genomic alterations and pathways that are deregulated in these tumors to find novel therapeutic targets for pulmonary carcinoid tumors. Experimental Design: We performed integrated genomic analysis of carcinoid tumors comprising whole genome and exome sequencing, mRNA expression profiling and SNP genotyping of specimens from normal lung, TC and AC, and small cell lung carcinoma (SCLC) to fully represent the lung neuroendocrine tumor spectrum. Results: Analysis of sequencing data found recurrent mutations in cancer genes including ATP1A2, CNNM1, MACF1, RAB38, NF1, RAD51C, TAF1L, EPHB2, POLR3B , and AGFG1 The mutated genes are involved in biological processes including cellular metabolism, cell division cycle, cell death, apoptosis, and immune regulation. The top most significantly mutated genes were TMEM41B, DEFB127, WDYHV1, and TBPL1 Pathway analysis of significantly mutated and cancer driver genes implicated MAPK/ERK and amyloid beta precursor protein (APP) pathways whereas analysis of CNV and gene expression data suggested deregulation of the NF-κB and MAPK/ERK pathways. The mutation signature was predominantly C>T and T>C transitions with a minor contribution of T>G transversions. Conclusions: This study identified mutated genes affecting cancer relevant pathways and biological processes that could provide opportunities for developing targeted therapies for pulmonary carcinoid tumors. Clin Cancer Res; 24(7); 1691-704. ©2018 AACR . ©2018 American Association for Cancer Research.

USP22 regulates oncogenic signaling pathways to drive lethal cancer progression.

PubMed

Schrecengost, Randy S; Dean, Jeffry L; Goodwin, Jonathan F; Schiewer, Matthew J; Urban, Mark W; Stanek, Timothy J; Sussman, Robyn T; Hicks, Jessica L; Birbe, Ruth C; Draganova-Tacheva, Rossitza A; Visakorpi, Tapio; DeMarzo, Angelo M; McMahon, Steven B; Knudsen, Karen E

2014-01-01

Increasing evidence links deregulation of the ubiquitin-specific proteases 22 (USP22) deubitiquitylase to cancer development and progression in a select group of tumor types, but its specificity and underlying mechanisms of action are not well defined. Here we show that USP22 is a critical promoter of lethal tumor phenotypes that acts by modulating nuclear receptor and oncogenic signaling. In multiple xenograft models of human cancer, modeling of tumor-associated USP22 deregulation demonstrated that USP22 controls androgen receptor accumulation and signaling, and that it enhances expression of critical target genes coregulated by androgen receptor and MYC. USP22 not only reprogrammed androgen receptor function, but was sufficient to induce the transition to therapeutic resistance. Notably, in vivo depletion experiments revealed that USP22 is critical to maintain phenotypes associated with end-stage disease. This was a significant finding given clinical evidence that USP22 is highly deregulated in tumors, which have achieved therapeutic resistance. Taken together, our findings define USP22 as a critical effector of tumor progression, which drives lethal phenotypes, rationalizing this enzyme as an appealing therapeutic target to treat advanced disease.

Neuroblastoma pathogenesis: deregulation of embryonic neural crest development.

PubMed

Tomolonis, Julie A; Agarwal, Saurabh; Shohet, Jason M

2018-05-01

Neuroblastoma (NB) is an aggressive pediatric cancer that originates from neural crest tissues of the sympathetic nervous system. NB is highly heterogeneous both from a clinical and a molecular perspective. Clinically, this cancer represents a wide range of phenotypes ranging from spontaneous regression of 4S disease to unremitting treatment-refractory progression and death of high-risk metastatic disease. At a cellular level, the heterogeneous behavior of NB likely arises from an arrest and deregulation of normal neural crest development. In the present review, we summarize our current knowledge of neural crest development as it relates to pathways promoting 'stemness' and how deregulation may contribute to the development of tumor-initiating CSCs. There is an emerging consensus that such tumor subpopulations contribute to the evolution of drug resistance, metastasis and relapse in other equally aggressive malignancies. As relapsed, refractory disease remains the primary cause of death for neuroblastoma, the identification and targeting of CSCs or other primary drivers of tumor progression remains a critical, clinically significant goal for neuroblastoma. We will critically review recent and past evidence in the literature supporting the concept of CSCs as drivers of neuroblastoma pathogenesis.

Synergy between the classical and alternative pathways of complement is essential for conferring effective protection against the pandemic influenza A(H1N1) 2009 virus infection

PubMed Central

Rattan, Ajitanuj; Pawar, Shailesh D.; Nawadkar, Renuka; Kulkarni, Neeraja

2017-01-01

The pandemic influenza A(H1N1) 2009 virus caused significant morbidity and mortality worldwide thus necessitating the need to understand the host factors that influence its control. Previously, the complement system has been shown to provide protection during the seasonal influenza virus infection, however, the role of individual complement pathways is not yet clear. Here, we have dissected the role of intact complement as well as of its individual activation pathways during the pandemic influenza virus infection using mouse strains deficient in various complement components. We show that the virus infection in C3-/- mice results in increased viral load and 100% mortality, which can be reversed by adoptive transfer of naïve wild-type (WT) splenocytes, purified splenic B cells, or passive transfer of immune sera from WT, but not C3-/- mice. Blocking of C3a and/or C5a receptor signaling in WT mice using receptor antagonists and use of C3aR-/- and C5aR-/- mice showed significant mortality after blocking/ablation of C3aR, with little or no effect after blocking/ablation of C5aR. Intriguingly, deficiency of C4 and FB in mice resulted in only partial mortality (24%-32%) suggesting a necessary cross-talk between the classical/lectin and alternative pathways for providing effective protection. In vitro virus neutralization experiments performed to probe the cross-talk between the various pathways indicated that activation of the classical and alternative pathways in concert, owing to coating of viral surface by antibodies, is needed for its efficient neutralization. Examination of the virus-specific complement-binding antibodies in virus positive subjects showed that their levels vary among individuals. Together these results indicate that cooperation between the classical and alternative pathways not only result in efficient direct neutralization of the pandemic influenza virus, but also lead to the optimum generation of C3a, which when sensed by the immune cells along with the antigen culminates in generation of effective protective immune responses. PMID:28301559

Cluster Analysis Identifies Distinct Pathogenetic Patterns in C3 Glomerulopathies/Immune Complex-Mediated Membranoproliferative GN.

PubMed

Iatropoulos, Paraskevas; Daina, Erica; Curreri, Manuela; Piras, Rossella; Valoti, Elisabetta; Mele, Caterina; Bresin, Elena; Gamba, Sara; Alberti, Marta; Breno, Matteo; Perna, Annalisa; Bettoni, Serena; Sabadini, Ettore; Murer, Luisa; Vivarelli, Marina; Noris, Marina; Remuzzi, Giuseppe

2018-01-01

Membranoproliferative GN (MPGN) was recently reclassified as alternative pathway complement-mediated C3 glomerulopathy (C3G) and immune complex-mediated membranoproliferative GN (IC-MPGN). However, genetic and acquired alternative pathway abnormalities are also observed in IC-MPGN. Here, we explored the presence of distinct disease entities characterized by specific pathophysiologic mechanisms. We performed unsupervised hierarchical clustering, a data-driven statistical approach, on histologic, genetic, and clinical data and data regarding serum/plasma complement parameters from 173 patients with C3G/IC-MPGN. This approach divided patients into four clusters, indicating the existence of four different pathogenetic patterns. Specifically, this analysis separated patients with fluid-phase complement activation (clusters 1-3) who had low serum C3 levels and a high prevalence of genetic and acquired alternative pathway abnormalities from patients with solid-phase complement activation (cluster 4) who had normal or mildly altered serum C3, late disease onset, and poor renal survival. In patients with fluid-phase complement activation, those in clusters 1 and 2 had massive activation of the alternative pathway, including activation of the terminal pathway, and the highest prevalence of subendothelial deposits, but those in cluster 2 had additional activation of the classic pathway and the highest prevalence of nephrotic syndrome at disease onset. Patients in cluster 3 had prevalent activation of C3 convertase and highly electron-dense intramembranous deposits. In addition, we provide a simple algorithm to assign patients with C3G/IC-MPGN to specific clusters. These distinct clusters may facilitate clarification of disease etiology, improve risk assessment for ESRD, and pave the way for personalized treatment. Copyright © 2018 by the American Society of Nephrology.

Deregulation of Feedback Inhibition of Phosphoenolpyruvate Carboxylase for Improved Lysine Production in Corynebacterium glutamicum

PubMed Central

Chen, Zhen; Bommareddy, Rajesh Reddy; Frank, Doinita; Rappert, Sugima

2014-01-01

Allosteric regulation of phosphoenolpyruvate carboxylase (PEPC) controls the metabolic flux distribution of anaplerotic pathways. In this study, the feedback inhibition of Corynebacterium glutamicum PEPC was rationally deregulated, and its effect on metabolic flux redistribution was evaluated. Based on rational protein design, six PEPC mutants were designed, and all of them showed significantly reduced sensitivity toward aspartate and malate inhibition. Introducing one of the point mutations (N917G) into the ppc gene, encoding PEPC of the lysine-producing strain C. glutamicum LC298, resulted in ∼37% improved lysine production. In vitro enzyme assays and 13C-based metabolic flux analysis showed ca. 20 and 30% increases in the PEPC activity and corresponding flux, respectively, in the mutant strain. Higher demand for NADPH in the mutant strain increased the flux toward pentose phosphate pathway, which increased the supply of NADPH for enhanced lysine production. The present study highlights the importance of allosteric regulation on the flux control of central metabolism. The strategy described here can also be implemented to improve other oxaloacetate-derived products. PMID:24334667

Deregulation of feedback inhibition of phosphoenolpyruvate carboxylase for improved lysine production in Corynebacterium glutamicum.

PubMed

Chen, Zhen; Bommareddy, Rajesh Reddy; Frank, Doinita; Rappert, Sugima; Zeng, An-Ping

2014-02-01

Allosteric regulation of phosphoenolpyruvate carboxylase (PEPC) controls the metabolic flux distribution of anaplerotic pathways. In this study, the feedback inhibition of Corynebacterium glutamicum PEPC was rationally deregulated, and its effect on metabolic flux redistribution was evaluated. Based on rational protein design, six PEPC mutants were designed, and all of them showed significantly reduced sensitivity toward aspartate and malate inhibition. Introducing one of the point mutations (N917G) into the ppc gene, encoding PEPC of the lysine-producing strain C. glutamicum LC298, resulted in ∼37% improved lysine production. In vitro enzyme assays and (13)C-based metabolic flux analysis showed ca. 20 and 30% increases in the PEPC activity and corresponding flux, respectively, in the mutant strain. Higher demand for NADPH in the mutant strain increased the flux toward pentose phosphate pathway, which increased the supply of NADPH for enhanced lysine production. The present study highlights the importance of allosteric regulation on the flux control of central metabolism. The strategy described here can also be implemented to improve other oxaloacetate-derived products.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD)-mediated deregulation of myeloid and sebaceous gland stem/progenitor cell homeostasis.

PubMed

Bock, Karl Walter

2017-06-01

Studies of TCDD toxicity stimulated identification of the responsible aryl hydrocarbon receptor (AHR), a multifunctional, ligand-activated transcription factor of the basic helix-loop-helix/Per-Arnt-Sim family. Accumulating evidence suggests a role of this receptor in homeostasis of stem/progenitor cells, in addition to its known role in xenobiotic metabolism. (1) Regulation of myelopoiesis is complex. As one example, AHR-mediated downregulation of human CD34+ progenitor differentiation to monocytes/macrophages is discussed. (2) Accumulation of TCDD in sebum leads to deregulation of sebocyte differentiation via Blimp1-mediated inhibition of c-Myc signaling and stimulation of Wnt-mediated proliferation of interfollicular epidermis. The resulting sebaceous gland atrophy and formation of dermal cysts may explain the pathogenesis of chloracne, the hallmark of TCDD toxicity. (3) TCDD treatment of confluent liver stem cell-like rat WB-F344 cells leads to release from cell-cell contact inhibition via AHR-mediated crosstalk with multiple signaling pathways. Further work is needed to delineate AHR function in crosstalk with other signaling pathways.

APC sets the Wnt tone necessary for cerebral cortical progenitor development

PubMed Central

Nakagawa, Naoki; Li, Jingjun; Yabuno-Nakagawa, Keiko; Eom, Tae-Yeon; Cowles, Martis; Mapp, Tavien; Taylor, Robin; Anton, E.S.

2017-01-01

Adenomatous polyposis coli (APC) regulates the activity of β-catenin, an integral component of Wnt signaling. However, the selective role of the APC–β-catenin pathway in cerebral cortical development is unknown. Here we genetically dissected the relative contributions of APC-regulated β-catenin signaling in cortical progenitor development, a necessary early step in cerebral cortical formation. Radial progenitor-specific inactivation of the APC–β-catenin pathway indicates that the maintenance of appropriate β-catenin-mediated Wnt tone is necessary for the orderly differentiation of cortical progenitors and the resultant formation of the cerebral cortex. APC deletion deregulates β-catenin, leads to high Wnt tone, and disrupts Notch1 signaling and primary cilium maintenance necessary for radial progenitor functions. β-Catenin deregulation directly disrupts cilium maintenance and signaling via Tulp3, essential for intraflagellar transport of ciliary signaling receptors. Surprisingly, deletion of β-catenin or inhibition of β-catenin activity in APC-null progenitors rescues the APC-null phenotype. These results reveal that APC-regulated β-catenin activity in cortical progenitors sets the appropriate Wnt tone necessary for normal cerebral cortical development. PMID:28916710

Discovering the Deregulated Molecular Functions Involved in Malignant Transformation of Endometriosis to Endometriosis-Associated Ovarian Carcinoma Using a Data-Driven, Function-Based Analysis

PubMed Central

Chang, Chia-Ming; Yang, Yi-Ping; Chuang, Jen-Hua; Chuang, Chi-Mu; Lin, Tzu-Wei; Wang, Peng-Hui; Yu, Mu-Hsien

2017-01-01

The clinical characteristics of clear cell carcinoma (CCC) and endometrioid carcinoma EC) are concomitant with endometriosis (ES), which leads to the postulation of malignant transformation of ES to endometriosis-associated ovarian carcinoma (EAOC). Different deregulated functional areas were proposed accounting for the pathogenesis of EAOC transformation, and there is still a lack of a data-driven analysis with the accumulated experimental data in publicly-available databases to incorporate the deregulated functions involved in the malignant transformation of EOAC. We used the microarray gene expression datasets of ES, CCC and EC downloaded from the National Center for Biotechnology Information Gene Expression Omnibus (NCBI GEO) database. Then, we investigated the pathogenesis of EAOC by a data-driven, function-based analytic model with the quantified molecular functions defined by 1454 Gene Ontology (GO) term gene sets. This model converts the gene expression profiles to the functionome consisting of 1454 quantified GO functions, and then, the key functions involving the malignant transformation of EOAC can be extracted by a series of filters. Our results demonstrate that the deregulated oxidoreductase activity, metabolism, hormone activity, inflammatory response, innate immune response and cell-cell signaling play the key roles in the malignant transformation of EAOC. These results provide the evidence supporting the specific molecular pathways involved in the malignant transformation of EAOC. PMID:29113136

Simple method to distinguish between primary and secondary C3 deficiencies.

PubMed

Pereira de Carvalho Florido, Marlene; Ferreira de Paula, Patrícia; Isaac, Lourdes

2003-03-01

Due to the increasing numbers of reported clinical cases of complement deficiency in medical centers, clinicians are now more aware of the role of the complement system in the protection against infections caused by microorganisms. Therefore, clinical laboratories are now prepared to perform a number of diagnostic tests of the complement system other than the standard 50% hemolytic component assay. Deficiencies of alternative complement pathway proteins are related to severe and recurrent infections; and the application of easy, reliable, and low-cost methods for their detection and distinction are always welcome, notably in developing countries. When activation of the alternative complement pathway is evaluated in hemolytic agarose plates, some but not all human sera cross-react to form a late linear lysis. Since the formation of this linear lysis is dependent on C3 and factor B, it is possible to use late linear lysis to routinely screen for the presence of deficiencies of alternative human complement pathway proteins such as factor B. Furthermore, since linear lysis is observed between normal human serum and primary C3-deficient serum but not between normal human serum and secondary C3-deficient serum caused by the lack of factor H or factor I, this assay may also be used to discriminate between primary and secondary C3 deficiencies.

Defining the Complement Biomarker Profile of C3 Glomerulopathy

PubMed Central

Zhang, Yuzhou; Nester, Carla M.; Martin, Bertha; Skjoedt, Mikkel-Ole; Meyer, Nicole C.; Shao, Dingwu; Borsa, Nicolò; Palarasah, Yaseelan

2014-01-01

Background and objectives C3 glomerulopathy (C3G) applies to a group of renal diseases defined by a specific renal biopsy finding: a dominant pattern of C3 fragment deposition on immunofluorescence. The primary pathogenic mechanism involves abnormal control of the alternative complement pathway, although a full description of the disease spectrum remains to be determined. This study sought to validate and define the association of complement dysregulation with C3G and to determine whether specific complement pathway abnormalities could inform disease definition. Design, setting, participants, & measurements This study included 34 patients with C3G (17 with C3 glomerulonephritis [C3GN] and 17 with dense deposit disease [DDD]) diagnosed between 2008 and 2013 selected from the C3G Registry. Control samples (n=100) were recruited from regional blood drives. Nineteen complement biomarkers were assayed on all samples. Results were compared between C3G disease categories and with normal controls. Results Assessment of the alternative complement pathway showed that compared with controls, patients with C3G had lower levels of serum C3 (P<0.001 for both DDD and C3GN) and factor B (P<0.001 for both DDD and C3GN) as well as higher levels of complement breakdown products including C3d (P<0.001 for both DDD and C3GN) and Bb (P<0.001 for both DDD and C3GN). A comparison of terminal complement pathway proteins showed that although C5 levels were significantly suppressed (P<0.001 for both DDD and C3GN) its breakdown product C5a was significantly higher only in patients with C3GN (P<0.05). Of the other terminal pathway components (C6–C9), the only significant difference was in C7 levels between patients with C3GN and controls (P<0.01). Soluble C5b-9 was elevated in both diseases but only the difference between patients with C3GN and controls reached statistical significance (P<0.001). Levels of C3 nephritic factor activity were qualitatively higher in patients with DDD compared with patients with C3GN. Conclusions Complement biomarkers are significantly abnormal in patients with C3G compared with controls. These data substantiate the link between complement dysregulation and C3G and identify C3G interdisease differences. PMID:25341722

Quantitative proteomic analysis of paired colorectal cancer and non-tumorigenic tissues reveals signature proteins and perturbed pathways involved in CRC progression and metastasis.

PubMed

Sethi, Manveen K; Thaysen-Andersen, Morten; Kim, Hoguen; Park, Cheol Keun; Baker, Mark S; Packer, Nicolle H; Paik, Young-Ki; Hancock, William S; Fanayan, Susan

2015-08-03

Modern proteomics has proven instrumental in our understanding of the molecular deregulations associated with the development and progression of cancer. Herein, we profile membrane-enriched proteome of tumor and adjacent normal tissues from eight CRC patients using label-free nanoLC-MS/MS-based quantitative proteomics and advanced pathway analysis. Of the 948 identified proteins, 184 proteins were differentially expressed (P<0.05, fold change>1.5) between the tumor and non-tumor tissue (69 up-regulated and 115 down-regulated in tumor tissues). The CRC tumor and non-tumor tissues clustered tightly in separate groups using hierarchical cluster analysis of the differentially expressed proteins, indicating a strong CRC-association of this proteome subset. Specifically, cancer associated proteins such as FN1, TNC, DEFA1, ITGB2, MLEC, CDH17, EZR and pathways including actin cytoskeleton and RhoGDI signaling were deregulated. Stage-specific proteome signatures were identified including up-regulated ribosomal proteins and down-regulated annexin proteins in early stage CRC. Finally, EGFR(+) CRC tissues showed an EGFR-dependent down-regulation of cell adhesion molecules, relative to EGFR(-) tissues. Taken together, this study provides a detailed map of the altered proteome and associated protein pathways in CRC, which enhances our mechanistic understanding of CRC biology and opens avenues for a knowledge-driven search for candidate CRC protein markers. Copyright © 2015 Elsevier B.V. All rights reserved.

Pleiotropic Effects of Cell Wall Amidase LytA on Streptococcus pneumoniae Sensitivity to the Host Immune Response

PubMed Central

Ramos-Sevillano, Elisa; Urzainqui, Ana; Campuzano, Susana; Moscoso, Miriam; González-Camacho, Fernando; Domenech, Mirian; Rodríguez de Córdoba, Santiago; Sánchez-Madrid, Francisco; Brown, Jeremy S.; García, Ernesto

2014-01-01

The complement system is a key component of the host immune response for the recognition and clearance of Streptococcus pneumoniae. In this study, we demonstrate that the amidase LytA, the main pneumococcal autolysin, inhibits complement-mediated immunity independently of effects on pneumolysin by a complex process of impaired complement activation, increased binding of complement regulators, and direct degradation of complement C3. The use of human sera depleted of either C1q or factor B confirmed that LytA prevented activation of both the classical and alternative pathways, whereas pneumolysin inhibited only the classical pathway. LytA prevented binding of C1q and the acute-phase protein C-reactive protein to S. pneumoniae, thereby reducing activation of the classical pathway on the bacterial surface. In addition, LytA increased recruitment of the complement downregulators C4BP and factor H to the pneumococcal cell wall and directly cleaved C3b and iC3b to generate degradation products. As a consequence, C3b deposition and phagocytosis increased in the absence of LytA and were markedly enhanced for the lytA ply double mutant, confirming that a combination of LytA and Ply is essential for the establishment of pneumococcal pneumonia and sepsis in a murine model of infection. These data demonstrate that LytA has pleiotropic effects on complement activation, a finding which, in combination with the effects of pneumolysin on complement to assist with pneumococcal complement evasion, confirms a major role of both proteins for the full virulence of the microorganism during septicemia. PMID:25404032

Classical Complement Pathway Activation in the Kidneys of Women With Preeclampsia.

PubMed

Penning, Marlies; Chua, Jamie S; van Kooten, Cees; Zandbergen, Malu; Buurma, Aletta; Schutte, Joke; Bruijn, Jan Anthonie; Khankin, Eliyahu V; Bloemenkamp, Kitty; Karumanchi, S Ananth; Baelde, Hans

2015-07-01

A growing body of evidence suggests that complement dysregulation plays a role in the pathogenesis of preeclampsia. The kidney is one of the major organs affected in preeclampsia. Because the kidney is highly susceptible to complement activation, we hypothesized that preeclampsia is associated with renal complement activation. We performed a nationwide search for renal autopsy material in the Netherlands using a computerized database (PALGA). Renal tissue was obtained from 11 women with preeclampsia, 25 pregnant controls, and 14 nonpregnant controls with hypertension. The samples were immunostained for C4d, C1q, mannose-binding lectin, properdin, C3d, C5b-9, IgA, IgG, and IgM. Preeclampsia was significantly associated with renal C4d-a stable marker of complement activation-and the classical pathway marker C1q. In addition, the prevalence of IgM was significantly higher in the kidneys of the preeclamptic women. No other complement markers studied differed between the groups. Our findings in human samples were validated using a soluble fms-like tyrosine kinase 1 mouse model of preeclampsia. The kidneys in the soluble fms-like tyrosine kinase 1-injected mice had significantly more C4 deposits than the control mice. The association between preeclampsia and renal C4d, C1q, and IgM levels suggests that the classical complement pathway is involved in the renal injury in preeclampsia. Moreover, our finding that soluble fms-like tyrosine kinase 1-injected mice develop excess C4 deposits indicates that angiogenic dysregulation may play a role in complement activation within the kidney. We suggest that inhibiting complement activation may be beneficial for preventing the renal manifestations of preeclampsia. © 2015 American Heart Association, Inc.

Gene Expression Profiling Reveals a Massive, Aneuploidy-Dependent Transcriptional Deregulation and Distinct Differences between Lymph Node–Negative and Lymph Node–Positive Colon Carcinomas

PubMed Central

Grade, Marian; Hörmann, Patrick; Becker, Sandra; Hummon, Amanda B.; Wangsa, Danny; Varma, Sudhir; Simon, Richard; Liersch, Torsten; Becker, Heinz; Difilippantonio, Michael J.; Ghadimi, B. Michael; Ried, Thomas

2016-01-01

To characterize patterns of global transcriptional deregulation in primary colon carcinomas, we did gene expression profiling of 73 tumors [Unio Internationale Contra Cancrum stage II (n = 33) and stage III (n = 40)] using oligonucleotide microarrays. For 30 of the tumors, expression profiles were compared with those from matched normal mucosa samples. We identified a set of 1,950 genes with highly significant deregulation between tumors and mucosa samples (P < 1e–7). A significant proportion of these genes mapped to chromosome 20 (P = 0.01). Seventeen genes had a >5-fold average expression difference between normal colon mucosa and carcinomas, including up-regulation of MYC and of HMGA1, a putative oncogene. Furthermore, we identified 68 genes that were significantly differentially expressed between lymph node–negative and lymph node–positive tumors (P < 0.001), the functional annotation of which revealed a preponderance of genes that play a role in cellular immune response and surveillance. The microarray-derived gene expression levels of 20 deregulated genes were validated using quantitative real-time reverse transcription-PCR in >40 tumor and normal mucosa samples with good concordance between the techniques. Finally, we established a relationship between specific genomic imbalances, which were mapped for 32 of the analyzed colon tumors by comparative genomic hybridization, and alterations of global transcriptional activity. Previously, we had conducted a similar analysis of primary rectal carcinomas. The systematic comparison of colon and rectal carcinomas revealed a significant overlap of genomic imbalances and transcriptional deregulation, including activation of the Wnt/β-catenin signaling cascade, suggesting similar pathogenic pathways. PMID:17210682

Gene expression profiling reveals a massive, aneuploidy-dependent transcriptional deregulation and distinct differences between lymph node-negative and lymph node-positive colon carcinomas.

PubMed

Grade, Marian; Hörmann, Patrick; Becker, Sandra; Hummon, Amanda B; Wangsa, Danny; Varma, Sudhir; Simon, Richard; Liersch, Torsten; Becker, Heinz; Difilippantonio, Michael J; Ghadimi, B Michael; Ried, Thomas

2007-01-01

To characterize patterns of global transcriptional deregulation in primary colon carcinomas, we did gene expression profiling of 73 tumors [Unio Internationale Contra Cancrum stage II (n = 33) and stage III (n = 40)] using oligonucleotide microarrays. For 30 of the tumors, expression profiles were compared with those from matched normal mucosa samples. We identified a set of 1,950 genes with highly significant deregulation between tumors and mucosa samples (P < 1e-7). A significant proportion of these genes mapped to chromosome 20 (P = 0.01). Seventeen genes had a >5-fold average expression difference between normal colon mucosa and carcinomas, including up-regulation of MYC and of HMGA1, a putative oncogene. Furthermore, we identified 68 genes that were significantly differentially expressed between lymph node-negative and lymph node-positive tumors (P < 0.001), the functional annotation of which revealed a preponderance of genes that play a role in cellular immune response and surveillance. The microarray-derived gene expression levels of 20 deregulated genes were validated using quantitative real-time reverse transcription-PCR in >40 tumor and normal mucosa samples with good concordance between the techniques. Finally, we established a relationship between specific genomic imbalances, which were mapped for 32 of the analyzed colon tumors by comparative genomic hybridization, and alterations of global transcriptional activity. Previously, we had conducted a similar analysis of primary rectal carcinomas. The systematic comparison of colon and rectal carcinomas revealed a significant overlap of genomic imbalances and transcriptional deregulation, including activation of the Wnt/beta-catenin signaling cascade, suggesting similar pathogenic pathways.

Role of Ficolin-A and Lectin Complement Pathway in the Innate Defense against Pathogenic Aspergillus Species

PubMed Central

Bidula, Stefan; Kenawy, Hany; Ali, Youssif M.; Sexton, Darren; Schwaeble, Wilhelm J.

2013-01-01

Aspergillus species are saprophytic molds causing life-threatening invasive fungal infections in the immunocompromised host. Innate immune recognition, in particular, the mechanisms of opsonization and complement activation, has been reported to be an integral part of the defense against fungi. We have shown that the complement component ficolin-A significantly binds to Aspergillus conidia and hyphae in a concentration-dependent manner and was inhibited by N-acetylglucosamine and N-acetylgalactosamine. Calcium-independent binding to Aspergillus fumigatus and A. terreus was observed, but binding to A. flavus and A. niger was calcium dependent. Ficolin-A binding to conidia was increased under low-pH conditions, and opsonization led to enhanced binding of conidia to A549 airway epithelial cells. In investigations of the lectin pathway of complement activation, ficolin-A-opsonized conidia did not lead to lectin pathway-specific C4 deposition. In contrast, the collectin mannose binding lectin C (MBL-C) but not MBL-A led to efficient lectin pathway activation on A. fumigatus in the absence of ficolin-A. In addition, ficolin-A opsonization led to a modulation of the proinflammatory cytokine interleukin-8. We conclude that ficolin-A may play an important role in the innate defense against Aspergillus by opsonizing conidia, immobilizing this fungus through enhanced adherence to epithelial cells and modulation of inflammation. However, it appears that other immune pattern recognition molecules, i.e., those of the collectin MBL-C, are involved in the Aspergillus-lectin complement pathway activation rather than ficolin-A. PMID:23478320

Allelic Variants of Complement Genes Associated with Dense Deposit Disease

PubMed Central

Abrera-Abeleda, Maria Asuncion; Nishimura, Carla; Frees, Kathy; Jones, Michael; Maga, Tara; Katz, Louis M.; Zhang, Yuzhou

2011-01-01

The alternative pathway of the complement cascade plays a role in the pathogenesis of dense deposit disease (DDD). Deficiency of complement factor H and mutations in CFH associate with the development of DDD, but it is unknown whether allelic variants in other complement genes also associate with this disease. We studied patients with DDD and identified previously unreported sequence alterations in several genes in addition to allelic variants and haplotypes common to patients with DDD. We found that the likelihood of developing DDD increases with the presence of two or more risk alleles in CFH and C3. To determine the functional consequence of this finding, we measured the activity of the alternative pathway in serum samples from phenotypically normal controls genotyped for variants in CFH and C3. Alternative pathway activity was higher in the presence of variants associated with DDD. Taken together, these data confirm that DDD is a complex genetic disease and may provide targets for the development of disease-specific therapies. PMID:21784901

Plasma Exosomes Contribute to Microvascular Damage in Diabetic Retinopathy (DR) by Activating Classical Complement Pathway.

PubMed

Huang, Chao; Fisher, Kiera P; Hammer, Sandra S; Navitskaya, Svetlana; Blanchard, Gary J; Busik, Julia V

2018-06-04

Diabetic Retinopathy (DR) is a micro-vascular complication of diabetes and is the leading cause of vision loss in working-age adults. Recent studies have implicated the complement system as an emerging player in development of vascular damage and progression of DR. However, the role and activation of the complement system in DR is not well understood. Exosomes, small vesicles that are secreted into the extracellular environment, have a cargo of complement proteins in plasma suggesting that they can participate in causing vascular damage associated with DR. We demonstrate that IgG-laden exosomes in plasma activate the classical complement pathway, and that the quantity of these exosomes is increased in diabetes. Moreover, we show that lack of IgG in exosomes results in a reduction of retinal vascular damage in diabetic mice. Together, the results of this study demonstrate that complement activation by IgG-laden plasma exosomes could contribute to the development of DR. © 2018 by the American Diabetes Association.

Insight into the tumor suppressor function of CBP through the viral oncoprotein tax.

PubMed

Van Orden, K; Nyborg, J K

2000-01-01

CREB binding protein (CBP) is a cellular coactivator protein that regulates essentially all known pathways of gene expression. The transcriptional coactivator properties of CBP are utilized by at least 25 different transcription factors representing nearly all known classes of DNA binding proteins. Once bound to their target genes, these transcription factors are believed to tether CBP to the promoter, leading to activated transcription. CBP functions to stimulate transcription through direct recruitment of the general transcription machinery as well as acetylation of both histone and transcription factor substrates. Recent observations indicate that a critical dosage of CBP is required for normal development and tumor suppression, and that perturbations in CBP concentrations may disrupt cellular homeostasis. Furthermore, there is accumulating evidence that CBP deregulation plays a direct role in hematopoietic malignancies. However, the molecular events linking CBP deregulation and malignant transformation are unclear. Further insight into the function of CBP, and its role as a tumor suppressor, can be gained through recent studies of the human T-cell leukemia virus, type I (HTLV-I) Tax oncoprotein. Tax is known to utilize CBP to stimulate transcription from the viral promoter. However, recent data suggest that as a consequence of the Tax-CBP interaction, many cellular transcription factor pathways may be deregulated. Tax disruption of CBP function may play a key role in transformation of the HTLV-I-infected cell. Thus, Tax derailment of CBP may lend important information about the tumor suppressor properties of CBP and serve as a model for the role of CBP in hematopoietic malignancies.

Homocysteine regulates fatty acid and lipid metabolism in yeast

PubMed Central

Visram, Myriam; Radulovic, Maja; Steiner, Sabine; Malanovic, Nermina; Eichmann, Thomas O.; Wolinski, Heimo; Rechberger, Gerald N.; Tehlivets, Oksana

2018-01-01

S-Adenosyl-l-homocysteine hydrolase (AdoHcy hydrolase; Sah1 in yeast/AHCY in mammals) degrades AdoHcy, a by-product and strong product inhibitor of S-adenosyl-l-methionine (AdoMet)-dependent methylation reactions, to adenosine and homocysteine (Hcy). This reaction is reversible, so any elevation of Hcy levels, such as in hyperhomocysteinemia (HHcy), drives the formation of AdoHcy, with detrimental consequences for cellular methylation reactions. HHcy, a pathological condition linked to cardiovascular and neurological disorders, as well as fatty liver among others, is associated with a deregulation of lipid metabolism. Here, we developed a yeast model of HHcy to identify mechanisms that dysregulate lipid metabolism. Hcy supplementation to wildtype cells up-regulated cellular fatty acid and triacylglycerol content and induced a shift in fatty acid composition, similar to changes observed in mutants lacking Sah1. Expression of the irreversible bacterial pathway for AdoHcy degradation in yeast allowed us to dissect the impact of AdoHcy accumulation on lipid metabolism from the impact of elevated Hcy. Expression of this pathway fully suppressed the growth deficit of sah1 mutants as well as the deregulation of lipid metabolism in both the sah1 mutant and Hcy-exposed wildtype, showing that AdoHcy accumulation mediates the deregulation of lipid metabolism in response to elevated Hcy in yeast. Furthermore, Hcy supplementation in yeast led to increased resistance to cerulenin, an inhibitor of fatty acid synthase, as well as to a concomitant decline of condensing enzymes involved in very long-chain fatty acid synthesis, in line with the observed shift in fatty acid content and composition. PMID:29414770

The Anticomplementary Activity of ’Fusobacterium polymorphum’ in Normal and C-4 Deficient Sources of Guinea Pig Complement.

DTIC Science & Technology

1977-01-12

A complement consumption assay was used to show that the anticomplementary activity of a cell wall preparation from F. polymorphum in guinea pig complement...tests with C𔃾-deficient guinea pig sera confirmed that F. polymorphum cell walls were capable of generating alternate complement pathway activity in guinea pig sera.

Novel Scabies Mite Serpins Inhibit the Three Pathways of the Human Complement System

PubMed Central

Mika, Angela; Reynolds, Simone L.; Mohlin, Frida C.; Willis, Charlene; Swe, Pearl M.; Pickering, Darren A.; Halilovic, Vanja; Wijeyewickrema, Lakshmi C.; Pike, Robert N.; Blom, Anna M.; Kemp, David J.; Fischer, Katja

2012-01-01

Scabies is a parasitic infestation of the skin by the mite Sarcoptes scabiei that causes significant morbidity worldwide, in particular within socially disadvantaged populations. In order to identify mechanisms that enable the scabies mite to evade human immune defenses, we have studied molecules associated with proteolytic systems in the mite, including two novel scabies mite serine protease inhibitors (SMSs) of the serpin superfamily. Immunohistochemical studies revealed that within mite-infected human skin SMSB4 (54 kDa) and SMSB3 (47 kDa) were both localized in the mite gut and feces. Recombinant purified SMSB3 and SMSB4 did not inhibit mite serine and cysteine proteases, but did inhibit mammalian serine proteases, such as chymotrypsin, albeit inefficiently. Detailed functional analysis revealed that both serpins interfered with all three pathways of the human complement system at different stages of their activation. SMSB4 inhibited mostly the initial and progressing steps of the cascades, while SMSB3 showed the strongest effects at the C9 level in the terminal pathway. Additive effects of both serpins were shown at the C9 level in the lectin pathway. Both SMSs were able to interfere with complement factors without protease function. A range of binding assays showed direct binding between SMSB4 and seven complement proteins (C1, properdin, MBL, C4, C3, C6 and C8), while significant binding of SMSB3 occurred exclusively to complement factors without protease function (C4, C3, C8). Direct binding was observed between SMSB4 and the complement proteases C1s and C1r. However no complex formation was observed between either mite serpin and the complement serine proteases C1r, C1s, MASP-1, MASP-2 and MASP-3. No catalytic inhibition by either serpin was observed for any of these enzymes. In summary, the SMSs were acting at several levels mediating overall inhibition of the complement system and thus we propose that they may protect scabies mites from complement-mediated gut damage. PMID:22792350

Evolution and diversity of the complement system of poikilothermic vertebrates.

PubMed

Sunyer, J O; Lambris, J D

1998-12-01

In mammals the complement system plays an important role in innate and acquired host defense mechanisms against infection and in various immunoregulatory processes. The complement system is an ancient defense mechanism that is already present in the invertebrate deuterostomes. In these species as well as in agnathans (the most primitive vertebrate species), both the alternative and lectin pathway of complement activation are already present, and the complement system appears to be involved mainly in opsonization of foreign material. With the emergence of immunoglobulins in cartilaginous fish, the classical and lytic pathways first appear. The rest of the poikilothermic species, from teleosts to reptilians, appear to contain a well-developed complement system resembling that of homeothermic vertebrates. However, important differences remain. Unlike homeotherms, several species of poikilotherms have recently been shown to possess multiple forms of complement components (C3 and factor B) that are structurally and functionally more diverse than those of higher vertebrates. It is noteworthy that the multiple forms of C3 that have been characterized in several teleost fish are able to bind with varying efficiencies to various complement-activating surfaces. We hypothesize that this diversity has allowed these animals to expand their innate capacity for immune recognition.

Classical and alternative complement activation on photoreceptor outer segments drives monocyte-dependent retinal atrophy.

PubMed

Katschke, Kenneth J; Xi, Hongkang; Cox, Christian; Truong, Tom; Malato, Yann; Lee, Wyne P; McKenzie, Brent; Arceo, Rommel; Tao, Jianhua; Rangell, Linda; Reichelt, Mike; Diehl, Lauri; Elstrott, Justin; Weimer, Robby M; Campagne, Menno van Lookeren

2018-05-09

Geographic atrophy (GA), the advanced form of dry age-related macular degeneration (AMD), is characterized by progressive loss of retinal pigment epithelium cells and photoreceptors in the setting of characteristic extracellular deposits and remains a serious unmet medical need. While genetic predisposition to AMD is dominated by polymorphisms in complement genes, it remains unclear how complement activation contributes to retinal atrophy. Here we demonstrate that complement is activated on photoreceptor outer segments (POS) in the retina peripheral to atrophic lesions associated with GA. When exposed to human serum following outer blood-retinal barrier breakdown, POS act as potent activators of the classical and alternative complement pathway. In mouse models of retinal degeneration, classical and alternative pathway complement activation on photoreceptors contributed to the loss of photoreceptor function. This was dependent on C5a-mediated recruitment of peripheral blood monocytes but independent of resident microglia. Genetic or pharmacologic inhibition of both classical and alternative complement C3 and C5 convertases was required to reduce progressive degeneration of photoreceptor rods and cones. Our study implicates systemic classical and alternative complement proteins and peripheral blood monocytes as critical effectors of localized retinal degeneration with potential relevance for the contribution of complement activation to GA.

Defective downregulation of receptor tyrosine kinases in cancer

PubMed Central

Bache, Kristi G; Slagsvold, Thomas; Stenmark, Harald

2004-01-01

Most growth factors control cellular functions by activating specific receptor tyrosine kinases (RTKs). While overactivation of RTK signalling pathways is strongly associated with carcinogenesis, it is becoming increasingly clear that impaired deactivation of RTKs may also be a mechanism in cancer. A major deactivation pathway, receptor downregulation, involves ligand-induced endocytosis of the RTK and subsequent degradation in lysosomes. A complex molecular machinery that uses the small protein ubiquitin as a key regulator assures proper endocytosis and degradation of RTKs. Here we discuss evidence that implicates deregulation of this machinery in cancer. PMID:15229652

Complement activation in the tubulointerstitium: AKI, CKD, and in between.

PubMed

Brar, Jyoti E; Quigg, Richard J

2014-10-01

Complement activation is actively regulated to prevent injudicious activation, such as on peritubular endothelia and basolateral aspects of tubules. Miao et al. studied mice in which the key complement regulator, Crry, was deleted from tubular cells. This lacked functional consequence in unmanipulated animals. Yet, following ischemia-reperfusion, there was greater injury due to alternative pathway activation of C5. When the balance between complement activation and regulation is tipped towards the former, pathologic complement activation can ensue.

Relative Contribution of Cellular Complement Inhibitors CD59, CD46, and CD55 to Parainfluenza Virus 5 Inhibition of Complement-Mediated Neutralization

PubMed Central

Li, Yujia; Parks, Griffith D.

2018-01-01

The complement system is a part of the innate immune system that viruses need to face during infections. Many viruses incorporate cellular regulators of complement activation (RCA) to block complement pathways and our prior work has shown that Parainfluenza virus 5 (PIV5) incorporates CD55 and CD46 to delay complement-mediated neutralization. In this paper, we tested the role of a third individual RCA inhibitor CD59 in PIV5 interactions with complement pathways. Using a cell line engineered to express CD59, we show that small levels of functional CD59 are associated with progeny PIV5, which is capable of blocking assembly of the C5b-C9 membrane attack complex (MAC). PIV5 containing CD59 (PIV5-CD59) showed increased resistance to complement-mediated neutralization in vitro comparing to PIV5 lacking regulators. Infection of A549 cells with PIV5 and RSV upregulated CD59 expression. TGF-beta treatment of PIV5-infected cells also increased cell surface CD59 expression and progeny virions were more resistant to complement-mediated neutralization. A comparison of individual viruses containing only CD55, CD46, or CD59 showed a potency of inhibiting complement-mediated neutralization, which followed a pattern of CD55 > CD46 > CD59. PMID:29693588

Interaction of extremophilic archaeal viruses with human and mouse complement system and viral biodistribution in mice

PubMed Central

Wu, Linping; Uldahl, Kristine Buch; Chen, Fangfang; Benasutti, Halli; Logvinski, Deborah; Vu, Vivian; Banda, Nirmal K.; Peng, Xu; Simberg, Dmitri; Moghimi, Seyed Moein

2017-01-01

Archaeal viruses offer exceptional biophysical properties for modification and exploration of their potential in bionanotechnology, bioengineering and nanotherapeutic developments. However, the interaction of archaeal viruses with elements of the innate immune system has not been explored, which is a necessary prerequisite if their potential for biomedical applications to be realized. Here we show complement activation through lectin (via direct binding of MBL/MASPs) and alternative pathways by two extremophilic archaeal viruses (Sulfolobus monocaudavirus 1 and Sulfolobus spindle-shaped virus 2) in human serum. We further show some differences in initiation of complement activation pathways between these viruses. Since, Sulfolobus monocaudavirus 1 was capable of directly triggering the alternative pathway, we also demonstrate that the complement regulator factor H has no affinity for the viral surface, but factor H deposition is purely C3-dependent. This suggests that unlike some virulent pathogens Sulfolobus monocaudavirus 1 does not acquire factor H for protection. Complement activation with Sulfolobus monocaudavirus 1 also proceeds in murine sera through MBL-A/C as well as factor D-dependent manner, but C3 deficiency has no overall effect on viral clearance by organs of the reticuloendothelial system on intravenous injection. However, splenic deposition was significantly higher in C3 knockout animals compared with the corresponding wild type mice. We discuss the potential application of these viruses in biomedicine in relation to their complement activating properties. PMID:28846925

Alternative complement pathway activation during invasive coronary procedures in acute myocardial infarction and stable angina pectoris.

PubMed

Horváth, Zsófia; Csuka, Dorottya; Vargova, Katarina; Kovács, Andrea; Leé, Sarolta; Varga, Lilian; Préda, István; Tóth Zsámboki, Emese; Prohászka, Zoltán; Kiss, Róbert Gábor

2016-12-01

The effect of invasive percutaneous coronary procedures on complement activation has not been elucidated. We enrolled stable angina patients with elective percutaneous coronary intervention (SA-PCI, n=24), diagnostic coronary angiography (CA, n=52) and 23 patients with ST segment elevation myocardial infarction and primary PCI (STEMI-PCI). Complement activation products (C1rC1sC1inh, C3bBbP and SC5b-9) were measured on admission, 6 and 24h after coronary procedures. The alternative pathway product, C3bBbP significantly and reversibly increased 6h after elective PCI (baseline: 7.81AU/ml, 6h: 16.09AU/ml, 24h: 4.27AU/ml, p<0.01, n=23) and diagnostic angiography (baseline: 6.13AU/ml, 6h: 12.08AU/ml, 24h: 5.4AU/ml, p<0.01, n=52). Six hour C3bBbP values correlated with post-procedural CK, creatinine level and the applied contrast material volume (r=0.41, r=0.4, r=0.3, p<0.05, respectively). In STEMI-PCI, baseline C3bBbP level was higher, compared to SA-PCI or CA patients (11.33AU/ml vs. 7.81AU/ml or 6.13AU/ml, p<0.001). Similarly, the terminal complex (SC5b-9) level was already elevated at baseline compared to SA-PCI group (3.49AU/ml vs. 1.87AU/ml, p=0.011). Complement pathway products did not increase further after primary PCI. Elective coronary procedures induced transient alternative complement pathway activation, influenced by the applied contrast volume. In STEMI, the alternative complement pathway is promptly activated during the atherothrombotic event and PCI itself had no further detectable effect. Copyright © 2016 Elsevier B.V. All rights reserved.

Genetic landscape and deregulated pathways in B-cell lymphoid malignancies.

PubMed

Rosenquist, R; Beà, S; Du, M-Q; Nadel, B; Pan-Hammarström, Q

2017-11-01

With the introduction of next-generation sequencing, the genetic landscape of the complex group of B-cell lymphoid malignancies has rapidly been unravelled in recent years. This has provided important information about recurrent genetic events and identified key pathways deregulated in each lymphoma subtype. In parallel, there has been intense search and development of novel types of targeted therapy that 'hit' central mechanisms in lymphoma pathobiology, such as BTK, PI3K or BCL2 inhibitors. In this review, we will outline the current view of the genetic landscape of selected entities: follicular lymphoma, diffuse large B-cell lymphoma, mantle cell lymphoma, chronic lymphocytic leukaemia and marginal zone lymphoma. We will detail recurrent alterations affecting important signalling pathways, that is the B-cell receptor/NF-κB pathway, NOTCH signalling, JAK-STAT signalling, p53/DNA damage response, apoptosis and cell cycle regulation, as well as other perhaps unexpected cellular processes, such as immune regulation, cell migration, epigenetic regulation and RNA processing. Whilst many of these pathways/processes are commonly altered in different lymphoid tumors, albeit at varying frequencies, others are preferentially targeted in selected B-cell malignancies. Some of these genetic lesions are either involved in disease ontogeny or linked to the evolution of each disease and/or specific clinicobiological features, and some of them have been demonstrated to have prognostic and even predictive impact. Future work is especially needed to understand the therapy-resistant disease, particularly in patients treated with targeted therapy, and to identify novel targets and therapeutic strategies in order to realize true precision medicine in this clinically heterogeneous patient group. © 2017 The Association for the Publication of the Journal of Internal Medicine.

Deficiency in Mannose-Binding Lectin-Associated Serine Protease-2 Does Not Increase Susceptibility to Trypanosoma cruzi Infection

PubMed Central

Ribeiro, Carolina H.; Lynch, Nicholas J.; Stover, Cordula M.; Ali, Youssif M.; Valck, Carolina; Noya-Leal, Francisca; Schwaeble, Wilhelm J.; Ferreira, Arturo

2015-01-01

Trypanosoma cruzi is the causative agent of Chagas' disease, a chronic illness affecting 10 million people around the world. The complement system plays an important role in fighting microbial infections. The recognition molecules of the lectin pathway of complement activation, mannose-binding lectin (MBL), ficolins, and CL-11, bind to specific carbohydrates on pathogens, triggering complement activation through MBL-associated serine protease-2 (MASP-2). Previous in vitro work showed that human MBL and ficolins contribute to T. cruzi lysis. However, MBL-deficient mice are only moderately compromised in their defense against the parasite, as they may still activate the lectin pathway through ficolins and CL-11. Here, we assessed MASP-2-deficient mice, the only presently available mouse line with total lectin pathway deficiency, for a phenotype in T. cruzi infection. Total absence of lectin pathway functional activity did not confer higher susceptibility to T. cruzi infection, suggesting that it plays a minor role in the immune response against this parasite. PMID:25548381

Species Specificity of Vaccinia Virus Complement Control Protein for the Bovine Classical Pathway Is Governed Primarily by Direct Interaction of Its Acidic Residues with Factor I

PubMed Central

Kumar, Jitendra; Yadav, Viveka Nand; Phulera, Swastik; Kamble, Ashish; Gautam, Avneesh Kumar; Panwar, Hemendra Singh

2017-01-01

ABSTRACT Poxviruses display species tropism—variola virus is a human-specific virus, while vaccinia virus causes repeated outbreaks in dairy cattle. Consistent with this, variola virus complement regulator SPICE (smallpox inhibitor of complement enzymes) exhibits selectivity in inhibiting the human alternative complement pathway and vaccinia virus complement regulator VCP (vaccinia virus complement control protein) displays selectivity in inhibiting the bovine alternative complement pathway. In the present study, we examined the species specificity of VCP and SPICE for the classical pathway (CP). We observed that VCP is ∼43-fold superior to SPICE in inhibiting bovine CP. Further, functional assays revealed that increased inhibitory activity of VCP for bovine CP is solely due to its enhanced cofactor activity, with no effect on decay of bovine CP C3-convertase. To probe the structural basis of this specificity, we utilized single- and multi-amino-acid substitution mutants wherein 1 or more of the 11 variant VCP residues were substituted in the SPICE template. Examination of these mutants for their ability to inhibit bovine CP revealed that E108, E120, and E144 are primarily responsible for imparting the specificity and contribute to the enhanced cofactor activity of VCP. Binding and functional assays suggested that these residues interact with bovine factor I but not with bovine C4(H2O) (a moiety conformationally similar to C4b). Mapping of these residues onto the modeled structure of bovine C4b-VCP-bovine factor I supported the mutagenesis data. Taken together, our data help explain why the vaccine strain of vaccinia virus was able to gain a foothold in domesticated animals. IMPORTANCE Vaccinia virus was used for smallpox vaccination. The vaccine-derived virus is now circulating and causing outbreaks in dairy cattle in India and Brazil. However, the reason for this tropism is unknown. It is well recognized that the virus is susceptible to neutralization by the complement classical pathway (CP). Because the virus encodes a soluble complement regulator, VCP, we examined whether this protein displays selectivity in targeting bovine CP. Our data show that it does exhibit selectivity in inhibiting the bovine CP and that this is primarily determined by its amino acids E108, E120, and E144, which interact with bovine serine protease factor I to inactivate bovine C4b—one of the two subunits of CP C3-convertase. Of note, the variola complement regulator SPICE contains positively charged residues at these positions. Thus, these variant residues in VCP help enhance its potency against the bovine CP and thereby the fitness of the virus in cattle. PMID:28724763

Complement Depletion Protects Lupus-prone Mice from Ischemia-reperfusion-initiated Organ Injury

DTIC Science & Technology

2012-10-25

injury, we sought to evaluate whether complement inhibition mitigates organ damage. We found that complement deple- tion with cobra venom factor... venom factor and C5a receptor antagonist were able to protect mice from local tissue damage, treatment with C5a receptor antagonist was not able to...Complement depletion or blockage of the complement pathway using molecules such as cobra venom factor (CVF) (24, 33) and C5a receptor antagonists (C5aRA

NETosing Neutrophils Activate Complement Both on Their Own NETs and Bacteria via Alternative and Non-alternative Pathways

PubMed Central

Yuen, Joshua; Pluthero, Fred G.; Douda, David N.; Riedl, Magdalena; Cherry, Ahmed; Ulanova, Marina; Kahr, Walter H. A.; Palaniyar, Nades; Licht, Christoph

2016-01-01

Neutrophils deposit antimicrobial proteins, such as myeloperoxidase and proteases on chromatin, which they release as neutrophil extracellular traps (NETs). Neutrophils also carry key components of the complement alternative pathway (AP) such as properdin or complement factor P (CFP), complement factor B (CFB), and C3. However, the contribution of these complement components and complement activation during NET formation in the presence and absence of bacteria is poorly understood. We studied complement activation on NETs and a Gram-negative opportunistic bacterial pathogen Pseudomonas aeruginosa (PA01, PAKwt, and PAKgfp). Here, we show that anaphylatoxin C5a, formyl-methionyl-leucyl-phenylalanine (fMLP) and phorbol myristate acetate (PMA), which activates NADPH oxidase, induce the release of CFP, CFB, and C3 from neutrophils. In response to PMA or P. aeruginosa, neutrophils secrete CFP, deposit it on NETs and bacteria, and induce the formation of terminal complement complexes (C5b–9). A blocking anti-CFP antibody inhibited AP-mediated but not non-AP-mediated complement activation on NETs and P. aeruginosa. Therefore, NET-mediated complement activation occurs via both AP- and non AP-based mechanisms, and AP-mediated complement activation during NETosis is dependent on CFP. These findings suggest that neutrophils could use their “AP tool kit” to readily activate complement on NETs and Gram-negative bacteria, such as P. aeruginosa, whereas additional components present in the serum help to fix non-AP-mediated complement both on NETs and bacteria. This unique mechanism may play important roles in host defense and help to explain specific roles of complement activation in NET-related diseases. PMID:27148258

Complement-Mediated Enhancement of Monocyte Adhesion to Endothelial Cells by HLA Antibodies, and Blockade by a Specific Inhibitor of the Classical Complement Cascade, TNT003

PubMed Central

Valenzuela, Nicole M.; Thomas, Kimberly A.; Mulder, Arend; Parry, Graham C.; Panicker, Sandip; Reed, Elaine F.

2017-01-01

Background Antibody-mediated rejection (AMR) of most solid organs is characterized by evidence of complement activation and/or intragraft macrophages (C4d + and CD68+ biopsies). We previously demonstrated that crosslinking of HLA I by antibodies triggered endothelial activation and monocyte adhesion. We hypothesized that activation of the classical complement pathway at the endothelial cell surface by HLA antibodies would enhance monocyte adhesion through soluble split product generation, in parallel with direct endothelial activation downstream of HLA signaling. Methods Primary human aortic endothelial cells (HAEC) were stimulated with HLA class I antibodies in the presence of intact human serum complement. C3a and C5a generation, endothelial P-selectin expression, and adhesion of human primary and immortalized monocytes (Mono Mac 6) were measured. Alternatively, HAEC or monocytes were directly stimulated with purified C3a or C5a. Classical complement activation was inhibited by pretreatment of complement with an anti-C1s antibody (TNT003). Results Treatment of HAEC with HLA antibody and human complement increased the formation of C3a and C5a. Monocyte recruitment by human HLA antibodies was enhanced in the presence of intact human serum complement or purified C3a or C5a. Specific inhibition of the classical complement pathway using TNT003 or C1q-depleted serum significantly reduced adhesion of monocytes in the presence of human complement. Conclusions Despite persistent endothelial viability in the presence of HLA antibodies and complement, upstream complement anaphylatoxin production exacerbates endothelial exocytosis and leukocyte recruitment. Upstream inhibition of classical complement may be therapeutic to dampen mononuclear cell recruitment and endothelial activation characteristic of microvascular inflammation during AMR. PMID:28640789

Alteration of the microRNA network during the progression of Alzheimer's disease

PubMed Central

Lau, Pierre; Bossers, Koen; Janky, Rekin's; Salta, Evgenia; Frigerio, Carlo Sala; Barbash, Shahar; Rothman, Roy; Sierksma, Annerieke S R; Thathiah, Amantha; Greenberg, David; Papadopoulou, Aikaterini S; Achsel, Tilmann; Ayoubi, Torik; Soreq, Hermona; Verhaagen, Joost; Swaab, Dick F; Aerts, Stein; De Strooper, Bart

2013-01-01

An overview of miRNAs altered in Alzheimer's disease (AD) was established by profiling the hippocampus of a cohort of 41 late-onset AD (LOAD) patients and 23 controls, showing deregulation of 35 miRNAs. Profiling of miRNAs in the prefrontal cortex of a second independent cohort of 49 patients grouped by Braak stages revealed 41 deregulated miRNAs. We focused on miR-132-3p which is strongly altered in both brain areas. Downregulation of this miRNA occurs already at Braak stages III and IV, before loss of neuron-specific miRNAs. Next-generation sequencing confirmed a strong decrease of miR-132-3p and of three family-related miRNAs encoded by the same miRNA cluster on chromosome 17. Deregulation of miR-132-3p in AD brain appears to occur mainly in neurons displaying Tau hyper-phosphorylation. We provide evidence that miR-132-3p may contribute to disease progression through aberrant regulation of mRNA targets in the Tau network. The transcription factor (TF) FOXO1a appears to be a key target of miR-132-3p in this pathway. PMID:24014289

Exploring the Innate Immune System: Using Complement-Medicated Cell Lysis in the Classroom

ERIC Educational Resources Information Center

Fuller, Kevin G.

2008-01-01

The protein complement pathway comprises an important part of the innate immunity. The use of serum to demonstrate complement-mediated destruction across a series of bacterial dilutions allows an instructor to introduce a number of important biological concepts such as bacterial growth, activation cascades, and adaptive versus innate immunity.

Site-targeted complement inhibition by a complement receptor 2-conjugated inhibitor (mTT30) ameliorates post-injury neuropathology in mouse brains.

PubMed

Rich, Megan C; Keene, Chesleigh N; Neher, Miriam D; Johnson, Krista; Yu, Zhao-Xue; Ganivet, Antoine; Holers, V Michael; Stahel, Philip F

2016-03-23

Intracerebral complement activation after severe traumatic brain injury (TBI) leads to a cascade of neuroinflammatory pathological sequelae that propagate host-mediated secondary brain injury and adverse outcomes. There are currently no specific pharmacological agents on the market to prevent or mitigate the development of secondary cerebral insults after TBI. A novel chimeric CR2-fH compound (mTT30) provides targeted inhibition of the alternative complement pathway at the site of tissue injury. This experimental study was designed to test the neuroprotective effects of mTT30 in a mouse model of closed head injury. The administration of 500 μg mTT30 i.v. at 1 h, 4 h and 24 h after head injury attenuated complement C3 deposition in injured brains, reduced the extent of neuronal cell death, and decreased post-injury microglial activation, compared to vehicle-injected placebo controls. These data imply that site-targeted alternative pathway complement inhibition may represent a new promising therapeutic avenue for the future management of severe TBI. Copyright © 2016. Published by Elsevier Ireland Ltd.

Complement proteins bind to nanoparticle protein corona and undergo dynamic exchange in vivo

NASA Astrophysics Data System (ADS)

Chen, Fangfang; Wang, Guankui; Griffin, James I.; Brenneman, Barbara; Banda, Nirmal K.; Holers, V. Michael; Backos, Donald S.; Wu, Linping; Moghimi, Seyed Moein; Simberg, Dmitri

2017-05-01

When nanoparticles are intravenously injected into the body, complement proteins deposit on the surface of nanoparticles in a process called opsonization. These proteins prime the particle for removal by immune cells and may contribute toward infusion-related adverse effects such as allergic responses. The ways complement proteins assemble on nanoparticles have remained unclear. Here, we show that dextran-coated superparamagnetic iron oxide core-shell nanoworms incubated in human serum and plasma are rapidly opsonized with the third complement component (C3) via the alternative pathway. Serum and plasma proteins bound to the nanoworms are mostly intercalated into the nanoworm shell. We show that C3 covalently binds to these absorbed proteins rather than the dextran shell and the protein-bound C3 undergoes dynamic exchange in vitro. Surface-bound proteins accelerate the assembly of the complement components of the alternative pathway on the nanoworm surface. When nanoworms pre-coated with human plasma were injected into mice, C3 and other adsorbed proteins undergo rapid loss. Our results provide important insight into dynamics of protein adsorption and complement opsonization of nanomedicines.

mTOR Pathways in Cancer and Autophagy.

PubMed

Paquette, Mathieu; El-Houjeiri, Leeanna; Pause, Arnim

2018-01-12

TOR (target of rapamycin), an evolutionarily-conserved serine/threonine kinase, acts as a central regulator of cell growth, proliferation and survival in response to nutritional status, growth factor, and stress signals. It plays a crucial role in coordinating the balance between cell growth and cell death, depending on cellular conditions and needs. As such, TOR has been identified as a key modulator of autophagy for more than a decade, and several deregulations of this pathway have been implicated in a variety of pathological disorders, including cancer. At the molecular level, autophagy regulates several survival or death signaling pathways that may decide the fate of cancer cells; however, the relationship between autophagy pathways and cancer are still nascent. In this review, we discuss the recent cellular signaling pathways regulated by TOR, their interconnections to autophagy, and the clinical implications of TOR inhibitors in cancer.

Deregulation of HIF1-alpha and hypoxia-regulated pathways in hepatocellular carcinoma and corresponding non-malignant liver tissue--influence of a modulated host stroma on the prognosis of HCC.

PubMed

Simon, Frank; Bockhorn, Maximilian; Praha, Christian; Baba, Hideo A; Broelsch, Christoph E; Frilling, Andrea; Weber, Frank

2010-04-01

The aim of this study was to elucidate the role of HIF1A expression in hepatocellular carcinoma (HCC) and the corresponding non-malignant liver tissue and to correlate it with the clinical outcome of HCC patients after curative liver resection. HIF1A expression was determined by quantitative RT-PCR in HCC and corresponding non-malignant liver tissue of 53 patients surgically treated for HCC. High-density gene expression analysis and pathway analysis was performed on a selected subset of patients with high and low HIF1A expression in the non-malignant liver tissue. HIF1A over-expression in the apparently non-malignant liver tissue was a predictor of tumor recurrence and survival. The estimated 1-year and 5-year disease-free survival was significantly better in patients with low HIF1A expression in the non-malignant liver tissue when compared to those patients with high HIF1 expression (88.9% vs. 67.9% and 61.0% vs. 22.6%, respectively, p = 0.008). Based on molecular pathway analysis utilizing high-density gene-expression profiling, HIF1A related molecular networks were identified that contained genes involved in cell migration, cell homing, and cell-cell interaction. Our study identified a potential novel mechanism contributing to prognosis of HCC. The deregulation of HIF1A and its related pathways in the apparently non-malignant liver tissue provides for a modulated environment that potentially enhances or allows for HCC recurrence after curative resection.

Contribution of copy number variants involving nonsense-mediated mRNA decay pathway genes to neuro-developmental disorders.

PubMed

Nguyen, Lam S; Kim, Hyung-Goo; Rosenfeld, Jill A; Shen, Yiping; Gusella, James F; Lacassie, Yves; Layman, Lawrence C; Shaffer, Lisa G; Gécz, Jozef

2013-05-01

The nonsense-mediated mRNA decay (NMD) pathway functions not only to degrade transcripts containing premature termination codons (PTC), but also to regulate the transcriptome. UPF3B and RBM8A, important components of NMD, have been implicated in various forms of intellectual disability (ID) and Thrombocytopenia with Absent Radius (TAR) syndrome, which is also associated with ID. To gauge the contribution of other NMD factors to ID, we performed a comprehensive search for copy number variants (CNVs) of 18 NMD genes among individuals with ID and/or congenital anomalies. We identified 11 cases with heterozygous deletions of the genomic region encompassing UPF2, which encodes for a direct interacting protein of UPF3B. Using RNA-Seq, we showed that the genome-wide consequence of reduced expression of UPF2 is similar to that seen in patients with UPF3B mutations. Out of the 1009 genes found deregulated in patients with UPF2 deletions by at least 2-fold, majority (95%) were deregulated similarly in patients with UPF3B mutations. This supports the major role of deletion of UPF2 in ID. Furthermore, we found that four other NMD genes, UPF3A, SMG6, EIF4A3 and RNPS1 are frequently deleted and/or duplicated in the patients. We postulate that dosage imbalances of these NMD genes are likely to be the causes or act as predisposing factors for neuro-developmental disorders. Our findings further emphasize the importance of NMD pathway(s) in learning and memory.

The role of microRNA-155/liver X receptor pathway in experimental and idiopathic pulmonary fibrosis.

PubMed

Kurowska-Stolarska, Mariola; Hasoo, Manhl K; Welsh, David J; Stewart, Lynn; McIntyre, Donna; Morton, Brian E; Johnstone, Steven; Miller, Ashley M; Asquith, Darren L; Millar, Neal L; Millar, Ann B; Feghali-Bostwick, Carol A; Hirani, Nikhil; Crick, Peter J; Wang, Yuqin; Griffiths, William J; McInnes, Iain B; McSharry, Charles

2017-06-01

Idiopathic pulmonary fibrosis (IPF) is progressive and rapidly fatal. Improved understanding of pathogenesis is required to prosper novel therapeutics. Epigenetic changes contribute to IPF; therefore, microRNAs may reveal novel pathogenic pathways. We sought to determine the regulatory role of microRNA (miR)-155 in the profibrotic function of murine lung macrophages and fibroblasts, IPF lung fibroblasts, and its contribution to experimental pulmonary fibrosis. Bleomycin-induced lung fibrosis in wild-type and miR-155 -/- mice was analyzed by histology, collagen, and profibrotic gene expression. Mechanisms were identified by in silico and molecular approaches and validated in mouse lung fibroblasts and macrophages, and in IPF lung fibroblasts, using loss-and-gain of function assays, and in vivo using specific inhibitors. miR-155 -/- mice developed exacerbated lung fibrosis, increased collagen deposition, collagen 1 and 3 mRNA expression, TGF-β production, and activation of alternatively activated macrophages, contributed by deregulation of the miR-155 target gene the liver X receptor (LXR)α in lung fibroblasts and macrophages. Inhibition of LXRα in experimental lung fibrosis and in IPF lung fibroblasts reduced the exacerbated fibrotic response. Similarly, enforced expression of miR-155 reduced the profibrotic phenotype of IPF and miR-155 -/- fibroblasts. We describe herein a molecular pathway comprising miR-155 and its epigenetic LXRα target that when deregulated enables pathogenic pulmonary fibrosis. Manipulation of the miR-155/LXR pathway may have therapeutic potential for IPF. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Endocrine-disrupting chemicals in aquatic environment: what are the risks for fish gametes?

PubMed

Carnevali, Oliana; Santangeli, Stefania; Forner-Piquer, Isabel; Basili, Danilo; Maradonna, Francesca

2018-06-11

Over the past 25 years, extensive research in vertebrate species has identified several genomic pathways altered by exposures to anthropogenic chemicals with hormone-like activity mediated by their interaction with nuclear receptors. In addition, many pollutants have been shown to interfere with non-genomic (non-classical) pathways, but this mechanism of endocrine disruption is still poorly understood. Recently, the number of publications describing the effects of Endocrine disrupting chemicals (EDCs) on fish reproduction, focusing on the deregulation of the hypothalamus-pituitary-gonadal axis as well as on gamete quality, significantly increased. Depending on their ability to mimic endogenous hormones, the may differently affect male or female reproductive physiology. Inhibition of gametogenesis, development of intersex gonads, alteration of the gonadosomatic index, and decreased fertility rate have been largely documented. In males, alterations of sperm density, motility, and fertility have been observed in several wild species. Similar detrimental effects were described in females, including negative outcomes on oocyte growth and maturation plus the occurrence of apoptotic/autophagic processes. These pathways may affect gamete viability considered as one of the major indicators of reproductive endocrine disruption. Pollutants act also at DNA level producing DNA mutations and changes in epigenetic pathways inducing specific mechanisms of toxicity and/or aberrant cellular responses that may affect subsequent generation(s) through the germline. In conclusion, this review summarizes the effects caused by EDC exposure on fish reproduction, focusing on gametogenesis, giving a general overview of the different aspects dealing with this issue, from morphological alteration, deregulation of steroidogenesis, hormonal synthesis, and occurrence of epigenetic process.

Mesophilic Aeromonas sp. serogroup O:11 resistance to complement-mediated killing.

PubMed Central

Merino, S; Rubires, X; Aguilar, A; Albertí, S; Hernandez-Allés, S; Benedí, V J; Tomas, J M

1996-01-01

The complement activation by and resistance to complement-mediated killing of Aeromonas sp. strains from serogroup O:11 were investigated by using different wild-type strains (with an S-layer characteristic of this serogroup) and their isogenic mutants characterized for their surface components (S-layer and lipopolysaccharide [LPS]). All of the Aeromonas sp. serogroup O:11 wild-type strains are unable to activate complement, which suggested that the S-layer completely covered the LPS molecules. We found that the classical complement pathway is involved in serum killing of susceptible Aeromonas sp. mutant strains of serogroup O11, while the alternative complement pathway seems not to be involved, and that the complement activation seems to be independent of antibody. The smooth mutant strains devoid of the S-layer (S-layer isogenic mutants) or isogenic LPS mutant strains with a complete or rather complete LPS core (also without the S-layer) are able to activate complement but are resistant to complement-mediated killing. The reasons for this resistance are that C3b is rapidly degraded, and therefore the lytic membrane attack complex (C5b-9) is not formed. Isogenic LPS rough mutants with an incomplete LPS core are serum sensitive because they bind more C3b than the resistant strains, the C3b is not completely degraded, and therefore the lytic complex (C5b-9) is formed. PMID:8945581

The regulation and deregulation of Wnt signaling by PARK genes in health and disease.

PubMed

Berwick, Daniel C; Harvey, Kirsten

2014-02-01

Wingless/Int (Wnt) signaling pathways are signal transduction mechanisms that have been widely studied in the field of embryogenesis. Recent work has established a critical role for these pathways in brain development, especially of midbrain dopaminergic neurones. However, the fundamental importance of Wnt signaling for the normal function of mature neurones in the adult central nervous system has also lately been demonstrated by an increasing number of studies. Parkinson's disease (PD) is the second most prevalent neurodegenerative disease worldwide and is currently incurable. This debilitating disease is characterized by the progressive loss of a subset of midbrain dopaminergic neurones in the substantia nigra leading to typical extrapyramidal motor symptoms. The aetiology of PD is poorly understood but work performed over the last two decades has identified a growing number of genetic defects that underlie this condition. Here we review a growing body of data connecting genes implicated in PD--most notably the PARK genes--with Wnt signaling. These observations provide clues to the normal function of these proteins in healthy neurones and suggest that deregulated Wnt signaling might be a frequent pathomechanism leading to PD. These observations have implications for the pathogenesis and treatment of neurodegenerative diseases in general.

Effects of dipotassium-trioxohydroxytetrafluorotriborate, K2[B3O3F4OH], on cell viability and gene expression of common human cancer drug targets in a melanoma cell line.

PubMed

Pojskic, Lejla; Haveric, Sanin; Lojo-Kadric, Naida; Hadzic, Maida; Haveric, Anja; Galic, Zoran; Galic, Borivoj; Vullo, Daniela; Supuran, Claudiu T; Milos, Mladen

2016-12-01

Recently it was found that dipotassium-trioxohydroxytetrafluorotriborate, K2(B3O3F4OH), is a potent and highly specific inhibitor of precancerous cell processes. We conducted gene expression profiling of human melanoma cells before and after treatment with two concentrations (0.1 and 1 mM) of this boron inorganic derivative in order to assess its effects on deregulation of genes associated with tumor pathways. Parallel trypan blue exclusion assay was performed to assess the cytotoxicity effects of this chemical. Treatment with K2(B3O3F4OH) induced a significant decrease of cell viability in melanoma cellline at both tested concentrations. Furthermore, these treatments caused deregulation of more than 30 genes known as common anti-tumor drug targets. IGF-1 and hTERT were found to be significantly downregulated and this result may imply potential use of K2(B3O3F4OH) as an inhibitor or human telomerase and insulin-like growth factor 1, both of which are associated with various tumor pathways.

Loss of proteostasis induced by amyloid beta peptide in brain endothelial cells.

PubMed

Fonseca, Ana Catarina; Oliveira, Catarina R; Pereira, Cláudia F; Cardoso, Sandra M

2014-06-01

Abnormal accumulation of amyloid-β (Aβ) peptide in the brain is a pathological hallmark of Alzheimer's disease (AD). In addition to neurotoxic effects, Aβ also damages brain endothelial cells (ECs) and may thus contribute to the degeneration of cerebral vasculature, which has been proposed as an early pathogenic event in the course of AD and is able to trigger and/or potentiate the neurodegenerative process and cognitive decline. However, the mechanisms underlying Aβ-induced endothelial dysfunction are not completely understood. Here we hypothesized that Aβ impairs protein quality control mechanisms both in the secretory pathway and in the cytosol in brain ECs, leading cells to death. In rat brain RBE4 cells, we demonstrated that Aβ1-40 induces the failure of the ER stress-adaptive unfolded protein response (UPR), deregulates the ubiquitin-proteasome system (UPS) decreasing overall proteasome activity with accumulation of ubiquitinated proteins and impairs the autophagic protein degradation pathway due to failure in the autophagic flux, which culminates in cell demise. In conclusion, Aβ deregulates proteostasis in brain ECs and, as a consequence, these cells die by apoptosis. Copyright © 2014 Elsevier B.V. All rights reserved.

Translational Control in Cancer Etiology

PubMed Central

Ruggero, Davide

2013-01-01

The link between perturbations in translational control and cancer etiology is becoming a primary focus in cancer research. It has now been established that genetic alterations in several components of the translational apparatus underlie spontaneous cancers as well as an entire class of inherited syndromes known as “ribosomopathies” associated with increased cancer susceptibility. These discoveries have illuminated the importance of deregulations in translational control to very specific cellular processes that contribute to cancer etiology. In addition, a growing body of evidence supports the view that deregulation of translational control is a common mechanism by which diverse oncogenic pathways promote cellular transformation and tumor development. Indeed, activation of these key oncogenic pathways induces rapid and dramatic translational reprogramming both by increasing overall protein synthesis and by modulating specific mRNA networks. These translational changes promote cellular transformation, impacting almost every phase of tumor development. This paradigm represents a new frontier in the multihit model of cancer formation and offers significant promise for innovative cancer therapies. Current research, in conjunction with cutting edge technologies, will further enable us to explore novel mechanisms of translational control, functionally identify translationally controlled mRNA groups, and unravel their impact on cellular transformation and tumorigenesis. PMID:22767671

APC sets the Wnt tone necessary for cerebral cortical progenitor development.

PubMed

Nakagawa, Naoki; Li, Jingjun; Yabuno-Nakagawa, Keiko; Eom, Tae-Yeon; Cowles, Martis; Mapp, Tavien; Taylor, Robin; Anton, E S

2017-08-15

Adenomatous polyposis coli (APC) regulates the activity of β-catenin, an integral component of Wnt signaling. However, the selective role of the APC-β-catenin pathway in cerebral cortical development is unknown. Here we genetically dissected the relative contributions of APC-regulated β-catenin signaling in cortical progenitor development, a necessary early step in cerebral cortical formation. Radial progenitor-specific inactivation of the APC-β-catenin pathway indicates that the maintenance of appropriate β-catenin-mediated Wnt tone is necessary for the orderly differentiation of cortical progenitors and the resultant formation of the cerebral cortex. APC deletion deregulates β-catenin, leads to high Wnt tone, and disrupts Notch1 signaling and primary cilium maintenance necessary for radial progenitor functions. β-Catenin deregulation directly disrupts cilium maintenance and signaling via Tulp3, essential for intraflagellar transport of ciliary signaling receptors. Surprisingly, deletion of β-catenin or inhibition of β-catenin activity in APC-null progenitors rescues the APC-null phenotype. These results reveal that APC-regulated β-catenin activity in cortical progenitors sets the appropriate Wnt tone necessary for normal cerebral cortical development. © 2017 Nakagawa et al.; Published by Cold Spring Harbor Laboratory Press.

Adenomatous polyposis coli (APC) regulates miR17-92 cluster through β-catenin pathway in colorectal cancer.

PubMed

Li, Yajuan; Lauriola, Mattia; Kim, Donghwa; Francesconi, Mirko; D'Uva, Gabriele; Shibata, Dave; Malafa, Mokenge P; Yeatman, Timothy J; Coppola, Domenico; Solmi, Rossella; Cheng, Jin Q

2016-09-01

Adenomatous polyposis coli (APC) mutation is the most common genetic change in sporadic colorectal cancer (CRC). Although deregulations of miRNAs have been frequently reported in this malignancy, APC-regulated miRNAs have not been extensively documented. Here, by using an APC-inducible cell line and array analysis, we identified a total of 26 deregulated miRNAs. Among them, members of miR-17-92 cluster were dramatically inhibited by APC and induced by enforced expression of β-catenin. Furthermore, we demonstrate that activated β-catenin resulted from APC loss binds to and activates the miR-17-92 promoter. Notably, enforced expression of miR-19a overrides APC tumor suppressor activity, and knockdown of miR-19a in cancer cells with compromised APC function reduced their aggressive features in vitro. Finally, we observed that expression of miR-19a significantly correlates with β-catenin levels in colorectal cancer specimens, and it is associated to the aggressive stage of tumor progression. Thus, our study reveals that miR-17-92 cluster is directly regulated by APC/β-catenin pathway and could be a potential therapeutic target in colon cancers with aberrant APC/β-catenin signaling.

Homocysteine regulates fatty acid and lipid metabolism in yeast.

PubMed

Visram, Myriam; Radulovic, Maja; Steiner, Sabine; Malanovic, Nermina; Eichmann, Thomas O; Wolinski, Heimo; Rechberger, Gerald N; Tehlivets, Oksana

2018-04-13

S -Adenosyl-l-homocysteine hydrolase (AdoHcy hydrolase; Sah1 in yeast/AHCY in mammals) degrades AdoHcy, a by-product and strong product inhibitor of S -adenosyl-l-methionine (AdoMet)-dependent methylation reactions, to adenosine and homocysteine (Hcy). This reaction is reversible, so any elevation of Hcy levels, such as in hyperhomocysteinemia (HHcy), drives the formation of AdoHcy, with detrimental consequences for cellular methylation reactions. HHcy, a pathological condition linked to cardiovascular and neurological disorders, as well as fatty liver among others, is associated with a deregulation of lipid metabolism. Here, we developed a yeast model of HHcy to identify mechanisms that dysregulate lipid metabolism. Hcy supplementation to wildtype cells up-regulated cellular fatty acid and triacylglycerol content and induced a shift in fatty acid composition, similar to changes observed in mutants lacking Sah1. Expression of the irreversible bacterial pathway for AdoHcy degradation in yeast allowed us to dissect the impact of AdoHcy accumulation on lipid metabolism from the impact of elevated Hcy. Expression of this pathway fully suppressed the growth deficit of sah1 mutants as well as the deregulation of lipid metabolism in both the sah1 mutant and Hcy-exposed wildtype, showing that AdoHcy accumulation mediates the deregulation of lipid metabolism in response to elevated Hcy in yeast. Furthermore, Hcy supplementation in yeast led to increased resistance to cerulenin, an inhibitor of fatty acid synthase, as well as to a concomitant decline of condensing enzymes involved in very long-chain fatty acid synthesis, in line with the observed shift in fatty acid content and composition. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

The Hippo component YAP localizes in the nucleus of human papilloma virus positive oropharyngeal squamous cell carcinoma.

PubMed

Alzahrani, Faisal; Clattenburg, Leanne; Muruganandan, Shanmugam; Bullock, Martin; MacIsaac, Kaitlyn; Wigerius, Michael; Williams, Blair A; Graham, M Elise R; Rigby, Matthew H; Trites, Jonathan R B; Taylor, S Mark; Sinal, Christopher J; Fawcett, James P; Hart, Robert D

2017-02-22

HPV infection causes cervical cancer, mediated in part by the degradation of Scribble via the HPV E6 oncoprotein. Recently, Scribble has been shown to be an important regulator of the Hippo signaling cascade. Deregulation of the Hippo pathway induces an abnormal cellular transformation, epithelial to mesenchymal transition, which promotes oncogenic progression. Given the recent rise in oropharyngeal HPV squamous cell carcinoma we sought to determine if Hippo signaling components are implicated in oropharyngeal squamous cell carcinoma. Molecular and cellular techniques including immunoprecipiations, Western blotting and immunocytochemistry were used to identify the key Hippo pathway effector Yes-Associated Protein (YAP)1. Oropharyngeal tissue was collected from CO 2 laser resections, and probed with YAP1 antibody in tumor and pre-malignant regions of HPV positive OPSCC tissue. This study reveals that the Scribble binding protein Nitric Oxide Synthase 1 Adaptor Protein (NOS1AP) forms a complex with YAP. Further, the NOS1APa and NOS1APc isoforms show differential association with activated and non-activated YAP, and impact cellular proliferation. Consistent with deregulated Hippo signaling in OPSCC HPV tumors, we see a delocalization of Scribble and increased nuclear accumulation of YAP1 in an HPV-positive OPSCC. Our preliminary data indicates that NOS1AP isoforms differentially associate with YAP1, which, together with our previous findings, predicts that loss of YAP1 enhances cellular transformation. Moreover, YAP1 is highly accumulated in the nucleus of HPV-positive OPSCC, implying that Hippo signaling and possibly NOS1AP expression are de-regulated in OPSCC. Further studies will help determine if NOS1AP isoforms, Scribble and Hippo components will be useful biomarkers in OPSCC tumor biology.

Triatoma infestans Calreticulin: Gene Cloning and Expression of a Main Domain That Interacts with the Host Complement System.

PubMed

Weinberger, Katherine; Collazo, Norberto; Aguillón, Juan Carlos; Molina, María Carmen; Rosas, Carlos; Peña, Jaime; Pizarro, Javier; Maldonado, Ismael; Cattan, Pedro E; Apt, Werner; Ferreira, Arturo

2017-02-08

Triatoma infestans is an important hematophagous vector of Chagas disease, a neglected chronic illness affecting approximately 6 million people in Latin America. Hematophagous insects possess several molecules in their saliva that counteract host defensive responses. Calreticulin (CRT), a multifunctional protein secreted in saliva, contributes to the feeding process in some insects. Human CRT (HuCRT) and Trypanosoma cruzi CRT (TcCRT) inhibit the classical pathway of complement activation, mainly by interacting through their central S domain with complement component C1. In previous studies, we have detected CRT in salivary gland extracts from T. infestans We have called this molecule TiCRT. Given that the S domain is responsible for C1 binding, we have tested its role in the classical pathway of complement activation in vertebrate blood. We have cloned and characterized the complete nucleotide sequence of CRT from T. infestans , and expressed its S domain. As expected, this S domain binds to human C1 and, as a consequence, it inhibits the classical pathway of complement, at its earliest stage of activation, namely the generation of C4b. Possibly, the presence of TiCRT in the salivary gland represents an evolutionary adaptation in hematophagous insects to control a potential activation of complement proteins, present in the massive blood meal that they ingest, with deleterious consequences at least on the anterior digestive tract of these insects. © The American Society of Tropical Medicine and Hygiene.

Spectrum and management of complement immunodeficiencies (excluding hereditary angioedema) across Europe.

PubMed

Turley, A J; Gathmann, B; Bangs, C; Bradbury, M; Seneviratne, S; Gonzalez-Granado, L I; Hackett, S; Kutukculer, N; Alachkar, H; Hambleton, S; Ritterbusch, H; Kralickova, P; Marodi, L; Seidel, M G; Dueckers, G; Roesler, J; Huissoon, A; Baxendale, H; Litzman, J; Arkwright, P D

2015-02-01

Complement immunodeficiencies (excluding hereditary angioedema and mannose binding lectin deficiency) are rare. Published literature consists largely of case reports and small series. We collated data from 18 cities across Europe to provide an overview of primarily homozygous, rather than partial genotypes and their impact and management. Patients were recruited through the ESID registry. Clinical and laboratory information was collected onto standardized forms and analyzed using SPSS software. Seventy-seven patients aged 1 to 68 years were identified. 44 % presented in their first decade of life. 29 % had C2 deficiency, defects in 11 other complement factors were found. 50 (65 %) had serious invasive infections. 61 % of Neisseria meningitidis infections occurred in patients with terminal pathway defects, while 74 % of Streptococcus pneumoniae infections occurred in patients with classical pathway defects (p < 0.001). Physicians in the UK were more likely to prescribe antibiotic prophylaxis than colleagues on the Continent for patients with classical pathway defects. After diagnosis, 16 % of patients suffered serious bacterial infections. Age of the patient and use of prophylactic antibiotics were not associated with subsequent infection risk. Inflammatory/autoimmune diseases were not seen in patients with terminal pathway, but in one third of patients classical and alternative pathway defects. The clinical phenotypes of specific complement immunodeficiencies vary considerably both in terms of the predominant bacterial pathogen, and the risk and type of auto-inflammatory disease. Appreciation of these phenotypic differences should help both immunologists and other specialists in their diagnosis and management of these rare and complex patients.

The Regulatory Capacity of Bivalent Genes—A Theoretical Approach

PubMed Central

Thalheim, Torsten; Herberg, Maria; Loeffler, Markus; Galle, Joerg

2017-01-01

Bivalent genes are frequently associated with developmental and lineage specification processes. Resolving their bivalency enables fast changes in their expression, which potentially can trigger cell fate decisions. Here, we provide a theoretical model of bivalency that allows for predictions on the occurrence, stability and regulatory capacity of this prominent modification state. We suggest that bivalency enables balanced gene expression heterogeneity that constitutes a prerequisite of robust lineage priming in somatic stem cells. Moreover, we demonstrate that interactions between the histone and DNA methylation machineries together with the proliferation activity control the stability of the bivalent state and can turn it into an unmodified state. We suggest that deregulation of these interactions underlies cell transformation processes as associated with acute myeloid leukemia (AML) and provide a model of AML blast formation following deregulation of the Ten-eleven Translocation (TET) pathway. PMID:28513551

Keeping It All Going-Complement Meets Metabolism.

PubMed

Kolev, Martin; Kemper, Claudia

2017-01-01

The complement system is an evolutionary old and crucial component of innate immunity, which is key to the detection and removal of invading pathogens. It was initially discovered as a liver-derived sentinel system circulating in serum, the lymph, and interstitial fluids that mediate the opsonization and lytic killing of bacteria, fungi, and viruses and the initiation of the general inflammatory responses. Although work performed specifically in the last five decades identified complement also as a critical instructor of adaptive immunity-indicating that complement's function is likely broader than initially anticipated-the dominant opinion among researchers and clinicians was that the key complement functions were in principle defined. However, there is now a growing realization that complement activity goes well beyond "classic" immune functions and that this system is also required for normal (neuronal) development and activity and general cell and tissue integrity and homeostasis. Furthermore, the recent discovery that complement activation is not confined to the extracellular space but occurs within cells led to the surprising understanding that complement is involved in the regulation of basic processes of the cell, particularly those of metabolic nature-mostly via novel crosstalks between complement and intracellular sensor, and effector, pathways that had been overlooked because of their spatial separation. These paradigm shifts in the field led to a renaissance in complement research and provide new platforms to now better understand the molecular pathways underlying the wide-reaching effects of complement functions in immunity and beyond. In this review, we will cover the current knowledge about complement's emerging relationship with the cellular metabolism machinery with a focus on the functional differences between serum-circulating versus intracellularly active complement during normal cell survival and induction of effector functions. We will also discuss how taking a closer look into the evolution of key complement components not only made the functional connection between complement and metabolism rather "predictable" but how it may also give clues for the discovery of additional roles for complement in basic cellular processes.

Complement in Lupus Nephritis: New Perspectives.

PubMed

Bao, Lihua; Cunningham, Patrick N; Quigg, Richard J

2015-09-01

Systemic lupus erythematosus (SLE) is an autoimmune disorder caused by loss of tolerance to self-antigens, the production of autoantibodies and deposition of complement-fixing immune complexes (ICs) in injured tissues. SLE is characterized by a wide range of clinical manifestations and targeted organs, with lupus nephritis being one of the most serious complications. The complement system consists of three pathways and is tightly controlled by a set of regulatory proteins to prevent injudicious complement activation on host tissue. The involvement of the complement system in the pathogenesis of SLE is well accepted; yet, its exact role is still not clear. Complement plays dual roles in the pathogenesis of SLE. On the one hand, the complement system appears to have protective features in that hereditary homozygous deficiencies of classical pathway components, such as C1q and C4, are associated with an increased risk for SLE. On the other hand, IC-mediated activation of complement in affected tissues is clearly evident in both experimental and human SLE along with pathological features that are logical consequences of complement activation. Studies in genetically altered mice have shown that lack of complement inhibitors, such as complement factor H (CFH) or decay-accelerating factor (DAF) accelerates the development of experimental lupus nephritis, while treatment with recombinant protein inhibitors, such as Crry-Ig, CR2-Crry, CR2-DAF and CR2-CFH, ameliorates the disease development. Complement-targeted drugs, including soluble complement receptor 1 (TP10), C1 esterase inhibitor and a monoclonal anti-C5 antibody (eculizumab), have been shown to inhibit complement safely, and are now being investigated in a variety of clinical conditions. SLE is an autoimmune disorder which targets multiple systems. Complement is centrally involved and plays dual roles in the pathogenesis of SLE. Studies from experimental lupus models and clinical trials support the use of complement-targeted therapy in the treatment of SLE.

TGFβ pathway deregulation and abnormal phospho-SMAD2/3 staining in hereditary cerebral hemorrhage with amyloidosis-Dutch type.

PubMed

Grand Moursel, Laure; Munting, Leon P; van der Graaf, Linda M; van Duinen, Sjoerd G; Goumans, Marie-Jose T H; Ueberham, Uwe; Natté, Remco; van Buchem, Mark A; van Roon-Mom, Willeke M C; van der Weerd, Louise

2017-05-29

Hereditary cerebral hemorrhage with amyloidosis-Dutch type (HCHWA-D) is an early onset hereditary form of cerebral amyloid angiopathy (CAA) pathology, caused by the E22Q mutation in the amyloid β (Aβ) peptide. Transforming growth factor β1 (TGFβ1) is a key player in vascular fibrosis and in the formation of angiopathic vessels in transgenic mice. Therefore, we investigated whether the TGFβ pathway is involved in HCHWA-D pathogenesis in human postmortem brain tissue from frontal and occipital lobes. Components of the TGFβ pathway were analyzed with quantitative RT-PCR. TGFβ1 and TGFβ Receptor 2 (TGFBR2) gene expression levels were significantly increased in HCHWA-D in comparison to the controls, in both frontal and occipital lobes. TGFβ-induced pro-fibrotic target genes were also upregulated. We further assessed pathway activation by detecting phospho-SMAD2/3 (pSMAD2/3), a direct TGFβ down-stream signaling mediator, using immunohistochemistry. We found abnormal pSMAD2/3 granular deposits specifically on HCHWA-D angiopathic frontal and occipital vessels. We graded pSMAD2/3 accumulation in angiopathic vessels and found a positive correlation with the CAA load independent of the brain area. We also observed pSMAD2/3 granules in a halo surrounding occipital vessels, which was specific for HCHWA-D. The result of this study indicates an upregulation of TGFβ1 in HCHWA-D, as was found previously in AD with CAA pathology. We discuss the possible origins and implications of the TGFβ pathway deregulation in the microvasculature in HCHWA-D. These findings identify the TGFβ pathway as a potential biomarker of disease progression and a possible target of therapeutic intervention in HCHWA-D. © 2017 The Authors. Brain Pathology published by John Wiley & Sons Ltd on behalf of International Society of Neuropathology.

Nuclear export of RNA: Different sizes, shapes and functions.

PubMed

Williams, Tobias; Ngo, Linh H; Wickramasinghe, Vihandha O

2018-03-01

Export of protein-coding and non-coding RNA molecules from the nucleus to the cytoplasm is critical for gene expression. This necessitates the continuous transport of RNA species of different size, shape and function through nuclear pore complexes via export receptors and adaptor proteins. Here, we provide an overview of the major RNA export pathways in humans, highlighting the similarities and differences between each. Its importance is underscored by the growing appreciation that deregulation of RNA export pathways is associated with human diseases like cancer. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Modeling the effect of pathogenic mutations on the conformational landscape of protein kinases.

PubMed

Saladino, Giorgio; Gervasio, Francesco Luigi

2016-04-01

Most proteins assume different conformations to perform their cellular functions. This conformational dynamics is physiologically regulated by binding events and post-translational modifications, but can also be affected by pathogenic mutations. Atomistic molecular dynamics simulations complemented by enhanced sampling approaches are increasingly used to probe the effect of mutations on the conformational dynamics and on the underlying conformational free energy landscape of proteins. In this short review we discuss recent successful examples of simulations used to understand the molecular mechanism underlying the deregulation of physiological conformational dynamics due to non-synonymous single point mutations. Our examples are mostly drawn from the protein kinase family. Copyright © 2016 Elsevier Ltd. All rights reserved.

Calcium-independent haemolysis via the lectin pathway of complement activation in the guinea-pig and other *

PubMed Central

Zhang, Y; Suankratay, C; Zhang, X-H; Jones, D R; Lint, T F; Gewurz, H

1999-01-01

We previously reported that complement-dependent haemolysis of sheep erythrocytes (E) coated with mannan (M) and sensitized with human mannan-binding lectin (MBL) via the lectin pathway in man occurs in Mg-EGTA and requires alternative pathway amplification. Calcium was required for MBL binding to E-M, but once the E-M-MBL intermediate was formed, MBL was retained and haemolysis occurred in the absence of calcium. Comparable or greater lectin pathway haemolysis in the absence of calcium was observed upon incubation of E-M-MBL in guinea-pig, rat, dog and pig sera, and was further investigated in the guinea-pig, in which titres were much higher (∼14-fold) than in man, and in contrast to humans, greater than classical pathway haemolytic activity. As in human serum, no lysis was observed in C4- or C2-deficient guinea-pig serum until purified C4 or C2, respectively, were restored. However, lectin pathway haemolytic activity in the guinea-pig did not require the alternative pathway. Removal (>98%) of factor D activity by three sequential passages through Sephadex G-75, resulting in serum which retained a normal classical pathway but no alternative pathway haemolytic activity, did not reduce the ability of guinea-pig serum to mediate haemolysis via the lectin pathway. Further, the C3-convertase formed via the lectin pathway (E-M-MBL-C4,2) lysed in C2-deficient guinea-pig but not human serum chelated with EDTA, a condition which precludes alternative pathway amplification. Thus, lectin pathway haemolysis occurs efficiently in guinea-pig serum, in the absence of calcium and without requirement for alternative pathway amplification. The guinea-pig provides a model for studying the assembly and haemolytic function of a lectin pathway which contrasts with the lectin pathway of man, and allows for comparisons that may help clarify the role of this pathway in complement biology. PMID:10457224

Milk complement and the opsonophagocytosis and killing of Staphylococcus aureus mastitis isolates by bovine neutrophils.

PubMed

Barrio, Maria Belén; Rainard, Pascal; Poutrel, Bernard

2003-01-01

Phagocytosis of bacteria by bovine polymorphonuclear neutrophils (PMN) has long been regarded as essential for host defense against mastitis infection. Complement-mediated opsonisation by complement component 3 (C3) binding is an important component of the innate immune system. We investigated the role of milk complement as an opsonin and its involvement in the phagocytosis and killing of Staphylococcus aureus isolates from cases of bovine mastitis by bovine blood PMN. We show that deposition of milk C3 component occurred on six different isolates of S. aureus and that the alternative pathway was the sole complement pathway operating in milk of uninflamed mammary gland. This deposition was shown to occur at the same location as the capsule, but not on capsular antigen. Milk complement enhanced the chemiluminescence response of PMN induced by S. aureus. Nevertheless, the association of S. aureus to cells and the overall killing of bacteria by bovine PMN were not affected by the presence of milk complement. Therefore, as all milk samples contained antibodies to capsular polysaccharide type 5 and to other surface antigens, it is likely that milk antibodies were responsible for these two phagocytic events. Results of this study suggest that the deposition of milk complement components on the surface of S. aureus does not contribute to the defence of the mammary gland against S. aureus.

SCFSlmb E3 ligase-mediated degradation of Expanded is inhibited by the Hippo pathway in Drosophila

PubMed Central

Zhang, Hongtao; Li, Changqing; Chen, Hanqing; Wei, Chuanxian; Dai, Fei; Wu, Honggang; Dui, Wen; Deng, Wu-Min; Jiao, Renjie

2015-01-01

Deregulation of the evolutionarily conserved Hippo pathway has been implicated in abnormal development of animals and in several types of cancer. One mechanism of Hippo pathway regulation is achieved by controlling the stability of its regulatory components. However, the executive E3 ligases that are involved in this process, and how the process is regulated, remain poorly defined. In this study, we identify, through a genetic candidate screen, the SCFSlmb E3 ligase as a novel negative regulator of the Hippo pathway in Drosophila imaginal tissues via mediation of the degradation of Expanded (Ex). Mechanistic study shows that Slmb-mediated degradation of Ex is inhibited by the Hippo signaling. Considering the fact that Hippo signaling suppresses the transcription of ex, we propose that the Hippo pathway employs a double security mechanism to ensure fine-tuned homeostasis during development. PMID:25522691

A Riboproteomic Platform to Identify Novel Targets for Prostate Cancer Therapy

DTIC Science & Technology

2015-10-01

cell lines derived from RWPE1 prostatic epithelial cells after exposure to N-methyl-N- nitrosourea (MNU) (these cell lines are commercially available...is well established that the malignancy of cells is strongly linked to and dependent on aberrant protein synthesis . Current knowledge clearly...highlights deregulation of protein synthesis , in the development of prostate cancer, through aberrant activation of classical signaling pathways. It has

A pore-forming protein implements VLR-activated complement cytotoxicity in lamprey.

PubMed

Wu, Fenfang; Feng, Bo; Ren, Yong; Wu, Di; Chen, Yue; Huang, Shengfeng; Chen, Shangwu; Xu, Anlong

2017-01-01

Lamprey is a basal vertebrate with a unique adaptive immune system, which uses variable lymphocyte receptors (VLRs) for antigen recognition. Our previous study has shown that lamprey possessed a distinctive complement pathway activated by VLR. In this study, we identified a natterin family member-lamprey pore-forming protein (LPFP) with a jacalin-like lectin domain and an aerolysin-like pore-forming domain. LPFP had a high affinity with mannan and could form oligomer in the presence of mannan. LPFP could deposit on the surface of target cells, form pore-like complex resembling a wheel with hub and spokes, and mediate powerful cytotoxicity on target cells. These pore-forming proteins along with VLRs and complement molecules were essential for the specific cytotoxicity against exogenous pathogens and tumor cells. This unique cytotoxicity implemented by LPFP might emerge before or in parallel with the IgG-based classical complement lytic pathway completed by polyC9.

Modeling Signaling Networks to Advance New Cancer Therapies.

PubMed

Saez-Rodriguez, Julio; MacNamara, Aidan; Cook, Simon

2015-01-01

Cell signaling pathways control cells' responses to their environment through an intricate network of proteins and small molecules partitioned by intracellular structures, such as the cytoskeleton and nucleus. Our understanding of these pathways has been revised recently with the advent of more advanced experimental techniques; no longer are signaling pathways viewed as linear cascades of information flowing from membrane-bound receptors to the nucleus. Instead, such pathways must be understood in the context of networks, and studying such networks requires an integration of computational and experimental approaches. This understanding is becoming more important in designing novel therapies for diseases such as cancer. Using the MAPK (mitogen-activated protein kinase) and PI3K (class I phosphoinositide-3' kinase) pathways as case studies of cellular signaling, we give an overview of these pathways and their functions. We then describe, using a number of case studies, how computational modeling has aided in understanding these pathways' deregulation in cancer, and how such understanding can be used to optimally tailor current therapies or help design new therapies against cancer.

Regulation of the Hippo-YAP Pathway by Glucose Sensor O-GlcNAcylation.

PubMed

Peng, Changmin; Zhu, Yue; Zhang, Wanjun; Liao, Qinchao; Chen, Yali; Zhao, Xinyuan; Guo, Qiang; Shen, Pan; Zhen, Bei; Qian, Xiaohong; Yang, Dong; Zhang, Jin-San; Xiao, Dongguang; Qin, Weijie; Pei, Huadong

2017-11-02

The Hippo pathway is crucial in organ size control and tissue homeostasis, with deregulation leading to cancer. An extracellular nutrition signal, such as glucose, regulates the Hippo pathway activation. However, the mechanisms are still not clear. Here, we found that the Hippo pathway is directly regulated by the hexosamine biosynthesis pathway (HBP) in response to metabolic nutrients. Mechanistically, the core component of Hippo pathway (YAP) is O-GlcNAcylated by O-GlcNAc transferase (OGT) at serine 109. YAP O-GlcNAcylation disrupts its interaction with upstream kinase LATS1, prevents its phosphorylation, and activates its transcriptional activity. And this activation is not dependent on AMPK. We also identified OGT as a YAP-regulated gene that forms a feedback loop. Finally, we confirmed that glucose-induced YAP O-GlcNAcylation and activation promoted tumorigenesis. Together, our data establish a molecular mechanism and functional significance of the HBP in directly linking extracellular glucose signal to the Hippo-YAP pathway and tumorigenesis. Copyright © 2017 Elsevier Inc. All rights reserved.

Complement in the Initiation and Evolution of Rheumatoid Arthritis

PubMed Central

Holers, V. Michael; Banda, Nirmal K.

2018-01-01

The complement system is a major component of the immune system and plays a central role in many protective immune processes, including circulating immune complex processing and clearance, recognition of foreign antigens, modulation of humoral and cellular immunity, removal of apoptotic and dead cells, and engagement of injury resolving and tissue regeneration processes. In stark contrast to these beneficial roles, however, inadequately controlled complement activation underlies the pathogenesis of human inflammatory and autoimmune diseases, including rheumatoid arthritis (RA) where the cartilage, bone, and synovium are targeted. Recent studies of this disease have demonstrated that the autoimmune response evolves over time in an asymptomatic preclinical phase that is associated with mucosal inflammation. Notably, experimental models of this disease have demonstrated that each of the three major complement activation pathways plays an important role in recognition of injured joint tissue, although the lectin and amplification pathways exhibit particularly impactful roles in the initiation and amplification of damage. Herein, we review the complement system and focus on its multi-factorial role in human patients with RA and experimental murine models. This understanding will be important to the successful integration of the emerging complement therapeutics pipeline into clinical care for patients with RA. PMID:29892280

Novel insights into the pathways regulating the canine hair cycle and their deregulation in alopecia X.

PubMed

Brunner, Magdalena A T; Jagannathan, Vidhya; Waluk, Dominik P; Roosje, Petra; Linek, Monika; Panakova, Lucia; Leeb, Tosso; Wiener, Dominique J; Welle, Monika M

2017-01-01

Alopecia X is a hair cycle arrest disorder in Pomeranians. Histologically, kenogen and telogen hair follicles predominate, whereas anagen follicles are sparse. The induction of anagen relies on the activation of hair follicle stem cells and their subsequent proliferation and differentiation. Stem cell function depends on finely tuned interactions of signaling molecules and transcription factors, which are not well defined in dogs. We performed transcriptome profiling on skin biopsies to analyze altered molecular pathways in alopecia X. Biopsies from five affected and four non-affected Pomeranians were investigated. Differential gene expression revealed a downregulation of key regulator genes of the Wnt (CTNNB1, LEF1, TCF3, WNT10B) and Shh (SHH, GLI1, SMO, PTCH2) pathways. In mice it has been shown that Wnt and Shh signaling results in stem cell activation and differentiation Thus our findings are in line with the lack of anagen hair follicles in dogs with Alopecia X. We also observed a significant downregulation of the stem cell markers SOX9, LHX2, LGR5, TCF7L1 and GLI1 whereas NFATc1, a quiescence marker, was upregulated in alopecia X. Moreover, genes coding for enzymes directly involved in the sex hormone metabolism (CYP1A1, CYP1B1, HSD17B14) were differentially regulated in alopecia X. These findings are in agreement with the so far proposed but not yet proven deregulation of the sex hormone metabolism in this disease.

Evidence for the Deregulation of Protein Turnover Pathways in Atm-Deficient Mouse Cerebellum: An Organotypic Study.

PubMed

Kim, Catherine D; Reed, Ryan E; Juncker, Meredith A; Fang, Zhide; Desai, Shyamal D

2017-07-01

Interferon-stimulated gene 15 (ISG15), an antagonist of the ubiquitin pathway, is elevated in cells and brain tissues obtained from ataxia telangiectasia (A-T) patients. Previous studies reveal that an elevated ISG15 pathway inhibits ubiquitin-dependent protein degradation, leading to activation of basal autophagy as a compensatory mechanism for protein turnover in A-T cells. Also, genotoxic stress (ultraviolet [UV] radiation) deregulates autophagy and induces aberrant degradation of ubiquitylated proteins in A-T cells. In the current study, we show that, as in A-T cells, ISG15 protein expression is elevated in cerebellums and various other tissues obtained from Atm-compromised mice in an Atm-allele-dependent manner (Atm+/+ < Atm+/- < Atm-/-). Notably, in cerebellums, the brain part primarily affected in A-T, levels of ISG15 were significantly greater (3-fold higher) than cerebrums obtained from the same set of mice. Moreover, as in A-T cell culture, UV induces aberrant degradation of ubiquitylated proteins and autophagy in Atm-deficient, but not in Atm-proficient, cerebellar brain slices grown in culture. Thus, the ex vivo organotypic A-T mouse brain culture model mimics that of an A-T human cell culture model and could be useful for studying the role of ISG15-dependent proteinopathy in cerebellar neurodegeneration, a hallmark of A-T in humans. © 2017 American Association of Neuropathologists, Inc. All rights reserved.

Effect of complement depletion by cobra venom factor on fowlpox virus infection in chickens and chicken embryos.

PubMed Central

Ohta, H; Yoshikawa, Y; Kai, C; Yamanouchi, K; Taniguchi, H; Komine, K; Ishijima, Y; Okada, H

1986-01-01

The course of infection with an attenuated strain of fowlpox virus (FPV), which is known to induce antibody-independent activation of complement via the alternative pathway, was investigated in 1- to 3-day-old chickens and 14-day-old chicken embryos by treatment with cobra venom factor (CVF). CVF was found to inhibit complement activity transiently via the alternative pathway but not via the classical pathway. In chickens treated with CVF, virus growth in the skin was enhanced, and pock lesions tended to disseminate, leading to fatal infection in some birds. Histologically, an acute inflammation at an early stage of infection (within 3 days) was inhibited, and virus content in the pock lesion was increased. In chicken embryos with immature immune capacities, CVF treatment caused changes in pock morphology from clear pocks to diffuse ones, an increase in virus content in the pock, and inhibition of cell infiltration. Thus, FPV infection was aggravated in both CVF-treated chickens and chicken embryos. These results are discussed in relation to roles of complement in the elimination of virus at an early stage of FPV infection. Images PMID:3003397

Smoke Exposure Causes Endoplasmic Reticulum Stress and Lipid Accumulation in Retinal Pigment Epithelium through Oxidative Stress and Complement Activation*

PubMed Central

Kunchithapautham, Kannan; Atkinson, Carl; Rohrer, Bärbel

2014-01-01

Age-related macular degeneration (AMD) is a complex disease caused by genetic and environmental factors, including genetic variants in complement components and smoking. Smoke exposure leads to oxidative stress, complement activation, endoplasmic reticulum (ER) stress, and lipid dysregulation, which have all been proposed to be associated with AMD pathogenesis. Here we examine the effects of smoke exposure on the retinal pigment epithelium (RPE). Mice were exposed to cigarette smoke or filtered air for 6 months. RPE cells grown as stable monolayers were exposed to 5% cigarette smoke extract (CSE). Effects of smoke were determined by biochemical, molecular, and histological measures. Effects of the alternative pathway (AP) of complement and complement C3a anaphylatoxin receptor signaling were analyzed using knock-out mice or specific inhibitors. ER stress markers were elevated after smoke exposure in RPE of intact mice, which was eliminated in AP-deficient mice. To examine this relationship further, RPE monolayers were exposed to CSE. Short term smoke exposure resulted in production and release of complement C3, the generation of C3a, oxidative stress, complement activation on the cell membrane, and ER stress. Long term exposure to CSE resulted in lipid accumulation, and secretion. All measures were reversed by blocking C3a complement receptor (C3aR), alternative complement pathway signaling, and antioxidant therapy. Taken together, our results provide clear evidence that smoke exposure results in oxidative stress and complement activation via the AP, resulting in ER stress-mediated lipid accumulation, and further suggesting that oxidative stress and complement act synergistically in the pathogenesis of AMD. PMID:24711457

Plasma-based proteomics reveals immune response, complement and coagulation cascades pathway shifts in heat-stressed lactating dairy cows.

PubMed

Min, Li; Cheng, Jianbo; Zhao, Shengguo; Tian, He; Zhang, Yangdong; Li, Songli; Yang, Hongjian; Zheng, Nan; Wang, Jiaqi

2016-09-02

Heat stress (HS) has an enormous economic impact on the dairy industry. In recent years, many researchers have investigated changes in the gene expression and metabolomics profiles in dairy cows caused by HS. However, the proteomics profiles of heat-stressed dairy cows have not yet been completely elucidated. We compared plasma proteomics from HS-free and heat-stressed dairy cows using an iTRAQ labeling approach. After the depletion of high abundant proteins in the plasma, 1472 proteins were identified. Of these, 85 proteins were differentially abundant in cows exposed to HS relative to HS-free. Database searches combined with GO and KEGG pathway enrichment analyses revealed that many components of the complement and coagulation cascades were altered in heat-stressed cows compared with HS-free cows. Of these, many factors in the complement system (including complement components C1, C3, C5, C6, C7, C8, and C9, complement factor B, and factor H) were down-regulated by HS, while components of the coagulation system (including coagulation factors, vitamin K-dependent proteins, and fibrinogens) were up-regulated by HS. In conclusion, our results indicate that HS decreases plasma levels of complement system proteins, suggesting that immune function is impaired in dairy cows exposed to HS. Though many aspects of heat stress (HS) have been extensively researched, relatively little is known about the proteomics profile changes that occur during heat exposure. In this work, we employed a proteomics approach to investigate differential abundance of plasma proteins in HS-free and heat-stressed dairy cows. Database searches combined with GO and KEGG pathway enrichment analyses revealed that HS resulted in a decrease in complement components, suggesting that heat-stressed dairy cows have impaired immune function. In addition, through integrative analyses of proteomics and previous metabolomics, we showed enhanced glycolysis, lipid metabolic pathway shifts, and nitrogen repartitioning in dairy cows exposed to HS. Our findings expand our current knowledge on the effects of HS on plasma proteomics in dairy cows and offer a new perspective for future research. Copyright © 2016 Elsevier B.V. All rights reserved.

The Lectin Complement Pathway Is Involved in Protection Against Enteroaggregative Escherichia coli Infection.

PubMed

Adler Sørensen, Camilla; Rosbjerg, Anne; Hebbelstrup Jensen, Betina; Krogfelt, Karen Angeliki; Garred, Peter

2018-01-01

Enteroaggregative Escherichia coli (EAEC) causes acute and persistent diarrhea worldwide. Still, the involvement of host factors in EAEC infections is unresolved. Binding of recognition molecules from the lectin pathway of complement to EAEC strains have been observed, but the importance is not known. Our aim was to uncover the involvement of these molecules in innate complement dependent immune protection toward EAEC. Binding of mannose-binding lectin, ficolin-1, -2, and -3 to four prototypic EAEC strains, and ficolin-2 binding to 56 clinical EAEC isolates were screened by a consumption-based ELISA method. Flow cytometry was used to determine deposition of C4b, C3b, and the bactericidal C5b-9 membrane attack complex (MAC) on the bacteria in combination with different complement inhibitors. In addition, the direct serum bactericidal effect was assessed. Screening of the prototypic EAEC strains revealed that ficolin-2 was the major binder among the lectin pathway recognition molecules. However, among the clinical EAEC isolates only a restricted number ( n  = 5) of the isolates bound ficolin-2. Using the ficolin-2 binding isolate C322-17 as a model, we found that incubation with normal human serum led to deposition of C4b, C3b, and to MAC formation. No inhibition of complement deposition was observed when a C1q inhibitor was added, while partial inhibition was observed when ficolin-2 or factor D inhibitors were used separately. Combining the inhibitors against ficolin-2 and factor D led to virtually complete inhibition of complement deposition and protection against direct bacterial killing. These results demonstrate that ficolin-2 may play an important role in innate immune protection against EAEC when an appropriate ligand is exposed, but many EAEC strains evade lectin pathway recognition and may, therefore, circumvent this strategy of innate host immune protection.

Combining differential expression, chromosomal and pathway analyses for the molecular characterization of renal cell carcinoma

PubMed Central

Furge, Kyle A; Dykema, Karl; Petillo, David; Westphal, Michael; Zhang, Zhongfa; Kort, Eric J; Teh, Bin Tean

2007-01-01

Using high-throughput gene-expression profiling technology, we can now gain a better understanding of the complex biology that is taking place in cancer cells. This complexity is largely dictated by the abnormal genetic makeup of the cancer cells. This abnormal genetic makeup can have profound effects on cellular activities such as cell growth, cell survival and other regulatory processes. Based on the pattern of gene expression, or molecular signatures of the tumours, we can distinguish or subclassify different types of cancers according to their cell of origin, behaviour, and the way they respond to therapeutic agents and radiation. These approaches will lead to better molecular subclassification of tumours, the basis of personalized medicine. We have, to date, done whole-genome microarray gene-expression profiling on several hundreds of kidney tumours. We adopt a combined bioinformatic approach, based on an integrative analysis of the gene-expression data. These data are used to identify both cytogenetic abnormalities and molecular pathways that are deregulated in renal cell carcinoma (RCC). For example, we have identified the deregulation of the VHL-hypoxia pathway in clear-cell RCC, as previously known, and the c-Myc pathway in aggressive papillary RCC. Besides the more common clear-cell, papillary and chromophobe RCCs, we are currently characterizing the molecular signatures of rarer forms of renal neoplasia such as carcinoma of the collecting ducts, mixed epithelial and stromal tumours, chromosome Xp11 translocations associated with papillary RCC, renal medullary carcinoma, mucinous tubular and spindle-cell carcinoma, and a group of unclassified tumours. Continued development and improvement in the field of molecular profiling will better characterize cancer and provide more accurate diagnosis, prognosis and prediction of drug response. PMID:18542781

EBV latent membrane protein 1 activates Akt, NFkappaB, and Stat3 in B cell lymphomas.

PubMed

Shair, Kathy H Y; Bendt, Katherine M; Edwards, Rachel H; Bedford, Elisabeth C; Nielsen, Judith N; Raab-Traub, Nancy

2007-11-01

Latent membrane protein 1 (LMP1) is the major oncoprotein of Epstein-Barr virus (EBV). In transgenic mice, LMP1 promotes increased lymphoma development by 12 mo of age. This study reveals that lymphoma develops in B-1a lymphocytes, a population that is associated with transformation in older mice. The lymphoma cells have deregulated cell cycle markers, and inhibitors of Akt, NFkappaB, and Stat3 block the enhanced viability of LMP1 transgenic lymphocytes and lymphoma cells in vitro. Lymphoma cells are independent of IL4/Stat6 signaling for survival and proliferation, but have constitutively activated Stat3 signaling. These same targets are also deregulated in wild-type B-1a lymphomas that arise spontaneously through age predisposition. These results suggest that Akt, NFkappaB, and Stat3 pathways may serve as effective targets in the treatment of EBV-associated B cell lymphomas.

Prenatal maternal stress and wheeze in children: novel insights into epigenetic regulation

PubMed Central

Trump, Saskia; Bieg, Matthias; Gu, Zuguang; Thürmann, Loreen; Bauer, Tobias; Bauer, Mario; Ishaque, Naveed; Röder, Stefan; Gu, Lei; Herberth, Gunda; Lawerenz, Christian; Borte, Michael; Schlesner, Matthias; Plass, Christoph; Diessl, Nicolle; Eszlinger, Markus; Mücke, Oliver; Elvers, Horst-Dietrich; Wissenbach, Dirk K.; von Bergen, Martin; Herrmann, Carl; Weichenhan, Dieter; Wright, Rosalind J.; Lehmann, Irina; Eils, Roland

2016-01-01

Psychological stress during pregnancy increases the risk of childhood wheeze and asthma. However, the transmitting mechanisms remain largely unknown. Since epigenetic alterations have emerged as a link between perturbations in the prenatal environment and an increased disease risk we used whole genome bisulfite sequencing (WGBS) to analyze changes in DNA methylation in mothers and their children related to prenatal psychosocial stress and assessed its role in the development of wheeze in the child. We evaluated genomic regions altered in their methylation level due to maternal stress based of WGBS data of 10 mother-child-pairs. These data were complemented by longitudinal targeted methylation and transcriptional analyses in children from our prospective mother-child cohort LINA for whom maternal stress and wheezing information was available (n = 443). High maternal stress was associated with an increased risk for persistent wheezing in the child until the age of 5. Both mothers and children showed genome-wide alterations in DNA-methylation specifically in enhancer elements. Deregulated neuroendocrine and neurotransmitter receptor interactions were observed in stressed mothers and their children. In children but not in mothers, calcium- and Wnt-signaling required for lung maturation in the prenatal period were epigenetically deregulated and could be linked with wheezing later in children’s life. PMID:27349968

Prenatal maternal stress and wheeze in children: novel insights into epigenetic regulation.

PubMed

Trump, Saskia; Bieg, Matthias; Gu, Zuguang; Thürmann, Loreen; Bauer, Tobias; Bauer, Mario; Ishaque, Naveed; Röder, Stefan; Gu, Lei; Herberth, Gunda; Lawerenz, Christian; Borte, Michael; Schlesner, Matthias; Plass, Christoph; Diessl, Nicolle; Eszlinger, Markus; Mücke, Oliver; Elvers, Horst-Dietrich; Wissenbach, Dirk K; von Bergen, Martin; Herrmann, Carl; Weichenhan, Dieter; Wright, Rosalind J; Lehmann, Irina; Eils, Roland

2016-06-28

Psychological stress during pregnancy increases the risk of childhood wheeze and asthma. However, the transmitting mechanisms remain largely unknown. Since epigenetic alterations have emerged as a link between perturbations in the prenatal environment and an increased disease risk we used whole genome bisulfite sequencing (WGBS) to analyze changes in DNA methylation in mothers and their children related to prenatal psychosocial stress and assessed its role in the development of wheeze in the child. We evaluated genomic regions altered in their methylation level due to maternal stress based of WGBS data of 10 mother-child-pairs. These data were complemented by longitudinal targeted methylation and transcriptional analyses in children from our prospective mother-child cohort LINA for whom maternal stress and wheezing information was available (n = 443). High maternal stress was associated with an increased risk for persistent wheezing in the child until the age of 5. Both mothers and children showed genome-wide alterations in DNA-methylation specifically in enhancer elements. Deregulated neuroendocrine and neurotransmitter receptor interactions were observed in stressed mothers and their children. In children but not in mothers, calcium- and Wnt-signaling required for lung maturation in the prenatal period were epigenetically deregulated and could be linked with wheezing later in children's life.

Specificity of EIA immunoassay for complement factor Bb testing.

PubMed

Pavlov, Igor Y; De Forest, Nikol; Delgado, Julio C

2011-01-01

During the alternative complement pathway activation, factor B is cleaved in two fragments, Ba and Bb. Concentration of those fragments is about 2 logs lower than of factor B present in the blood, which makes fragment detection challenging because of potential cross-reactivity. Lack of information on Bb assay cross-reactivity stimulated the authors to investigate this issue. We ran 109 healthy donor EDTA plasmas and 80 sera samples with both factor B immunodiffusion (The Binding Site) and Quidel Bb EIA assays. During the study it was shown that physiological concentrations of gently purified factor B demonstrated approximately 0.15% cross-reactivity in the Quidel Bb EIA assay. We also observed that Bb concentration in serum is higher than in plasma due to complement activation during clot formation which let us use sera as samples representing complement activated state. Our study demonstrated that despite the potential 0.15% cross-reactivity between endogenous factor B and cleaved Bb molecule, measuring plasma concentrations of factor Bb is adequate to evaluate the activation of the alternative complement pathway.

Alteration of the microRNA network during the progression of Alzheimer's disease.

PubMed

Lau, Pierre; Bossers, Koen; Janky, Rekin's; Salta, Evgenia; Frigerio, Carlo Sala; Barbash, Shahar; Rothman, Roy; Sierksma, Annerieke S R; Thathiah, Amantha; Greenberg, David; Papadopoulou, Aikaterini S; Achsel, Tilmann; Ayoubi, Torik; Soreq, Hermona; Verhaagen, Joost; Swaab, Dick F; Aerts, Stein; De Strooper, Bart

2013-10-01

An overview of miRNAs altered in Alzheimer's disease (AD) was established by profiling the hippocampus of a cohort of 41 late-onset AD (LOAD) patients and 23 controls, showing deregulation of 35 miRNAs. Profiling of miRNAs in the prefrontal cortex of a second independent cohort of 49 patients grouped by Braak stages revealed 41 deregulated miRNAs. We focused on miR-132-3p which is strongly altered in both brain areas. Downregulation of this miRNA occurs already at Braak stages III and IV, before loss of neuron-specific miRNAs. Next-generation sequencing confirmed a strong decrease of miR-132-3p and of three family-related miRNAs encoded by the same miRNA cluster on chromosome 17. Deregulation of miR-132-3p in AD brain appears to occur mainly in neurons displaying Tau hyper-phosphorylation. We provide evidence that miR-132-3p may contribute to disease progression through aberrant regulation of mRNA targets in the Tau network. The transcription factor (TF) FOXO1a appears to be a key target of miR-132-3p in this pathway. © 2013 The Authors. Published by John Wiley and Sons, Ltd on behalf of EMBO.

Transcriptome and Small RNA Deep Sequencing Reveals Deregulation of miRNA Biogenesis in Human Glioma

PubMed Central

Moore, Lynette M.; Kivinen, Virpi; Liu, Yuexin; Annala, Matti; Cogdell, David; Liu, Xiuping; Liu, Chang-Gong; Sawaya, Raymond; Yli-Harja, Olli; Shmulevich, Ilya; Fuller, Gregory N.; Zhang, Wei; Nykter, Matti

2013-01-01

Altered expression of oncogenic and tumor-suppressing microRNAs (miRNAs) is widely associated with tumorigenesis. However, the regulatory mechanisms underlying these alterations are poorly understood. We sought to shed light on the deregulation of miRNA biogenesis promoting the aberrant miRNA expression profiles identified in these tumors. Using sequencing technology to perform both whole-transcriptome and small RNA sequencing of glioma patient samples, we examined precursor and mature miRNAs to directly evaluate the miRNA maturation process, and interrogated expression profiles for genes involved in the major steps of miRNA biogenesis. We found that ratios of mature to precursor forms of a large number of miRNAs increased with the progression from normal brain to low-grade and then to high-grade gliomas. The expression levels of genes involved in each of the three major steps of miRNA biogenesis (nuclear processing, nucleo-cytoplasmic transport, and cytoplasmic processing) were systematically altered in glioma tissues. Survival analysis of an independent data set demonstrated that the alteration of genes involved in miRNA maturation correlates with survival in glioma patients. Direct quantification of miRNA maturation with deep sequencing demonstrated that deregulation of the miRNA biogenesis pathway is a hallmark for glioma genesis and progression. PMID:23007860

Anopheles Midgut Epithelium Evades Human Complement Activity by Capturing Factor H from the Blood Meal

PubMed Central

Khattab, Ayman; Barroso, Marta; Miettinen, Tiera; Meri, Seppo

2015-01-01

Hematophagous vectors strictly require ingesting blood from their hosts to complete their life cycles. Exposure of the alimentary canal of these vectors to the host immune effectors necessitates efficient counteractive measures by hematophagous vectors. The Anopheles mosquito transmitting the malaria parasite is an example of hematophagous vectors that within seconds can ingest human blood double its weight. The innate immune defense mechanisms, like the complement system, in the human blood should thereby immediately react against foreign cells in the mosquito midgut. A prerequisite for complement activation is that the target cells lack complement regulators on their surfaces. In this work, we analyzed whether human complement is active in the mosquito midgut, and how the mosquito midgut cells protect themselves against complement attack. We found that complement remained active for a considerable time and was able to kill microbes within the mosquito midgut. However, the Anopheles mosquito midgut cells were not injured. These cells were found to protect themselves by capturing factor H, the main soluble inhibitor of the alternative complement pathway. Factor H inhibited complement on the midgut cells by promoting inactivation of C3b to iC3b and preventing the activity of the alternative pathway amplification C3 convertase enzyme. An interference of the FH regulatory activity by monoclonal antibodies, carried to the midgut via blood, resulted in increased mosquito mortality and reduced fecundity. By using a ligand blotting assay, a putative mosquito midgut FH receptor could be detected. Thereby, we have identified a novel mechanism whereby mosquitoes can tolerate human blood. PMID:25679788

From orphan drugs to adopted therapies: Advancing C3-targeted intervention to the clinical stage

PubMed Central

Mastellos, Dimitrios C.; Reis, Edimara S.; Yancopoulou, Despina; Hajishengallis, George; Ricklin, Daniel; Lambris, John D.

2016-01-01

Complement dysregulation is increasingly recognized as an important pathogenic driver in a number of clinical disorders. Complement-triggered pathways intertwine with key inflammatory and tissue destructive processes that can either increase the risk of disease or exacerbate pathology in acute or chronic conditions. The launch of the first complement-targeted drugs in the clinic has undeniably stirred the field of complement therapeutic design, providing new insights into complement's contribution to disease pathogenesis and also helping to leverage a more personalized, comprehensive approach to patient management. In this regard, a rapidly expanding toolbox of complement therapeutics is being developed to address unmet clinical needs in several immune-mediated and inflammatory diseases. Elegant approaches employing both surface-directed and fluid-phase inhibitors have exploited diverse components of the complement cascade as putative points of therapeutic intervention. Targeting C3, the central hub of the system, has proven to be a promising strategy for developing biologics as well as small-molecule inhibitors with clinical potential. Complement modulation at the level of C3 has recently shown promise in preclinical primate models, opening up new avenues for therapeutic intervention in both acute and chronic indications fueled by uncontrolled C3 turnover. This review highlights recent developments in the field of complement therapeutics, focusing on C3-directed inhibitors and alternative pathway (AP) regulator-based approaches. Translational perspectives and considerations are discussed, particularly with regard to the structure-guided drug optimization and clinical advancement of a new generation of C3-targeted peptidic inhibitors. PMID:27353192

Molecular Pathways: Hippo Signaling, a Critical Tumor Suppressor.

PubMed

Sebio, Ana; Lenz, Heinz-Josef

2015-11-15

The Salvador-Warts-Hippo pathway controls cell fate and tissue growth. The main function of the Hippo pathway is to prevent YAP and TAZ translocation to the nucleus where they induce the transcription of genes involved in cell proliferation, survival, and stem cell maintenance. Hippo signaling is, thus, a complex tumor suppressor, and its deregulation is a key feature in many cancers. Recent mounting evidence suggests that the overexpression of Hippo components can be useful prognostic biomarkers. Moreover, Hippo signaling appears to be intimately linked to some of the most important signaling pathways involved in cancer development and progression. A better understanding of the Hippo pathway is thus essential to untangle tumor biology and to develop novel anticancer therapies. Here, we comment on the progress made in understanding Hippo signaling and its connections, and also on how new drugs modulating this pathway, such as Verteporfin and C19, are highly promising cancer therapeutics. ©2015 American Association for Cancer Research.

Deregulation of miR-193b affects the growth of colon cancer cells via transforming growth factor-β and regulation of the SMAD3 pathway

PubMed Central

Wu, Kaiming; Zhao, Zhenxian; Ma, Jun; Chen, Jianhui; Peng, Jianjun; Yang, Shibin; He, Yulong

2017-01-01

MicroRNA-193b (miRNA-193b) is often differentially expressed and is an important regulator of gene expression in colon cancer. The aim of the present study was to determine whether miRNA-193b affects cell growth in colon cancer and to investigate the potential underlying mechanisms. Patients with colorectal cancer (CRC; n=20) and healthy volunteers (n=10) were enrolled from the Department of Gastrointestinal Surgery Center, First Affiliated Hospital of Sun Yat-Sen University (Guangzhou, China). Western blot analysis was used to evaluate the protein expression of SMAD3 and transforming growth factor-β (TGF-β) in the patient samples. It was determined that miRNA-193b expression was markedly elevated in the CRC tissue samples. Furthermore, silencing of miRNA-193bin SW620 CRC cells by specific inhibitors significantly reduced the cell proliferation and induced apoptosis. In addition, the downregulation of miRNA-193b significantly activated the protein expression of SMAD3 and TGF-β, and promoted caspase-3 activity in SW620 cells. The results of the present study suggested that the deregulation of miRNA-193b may affect cell growth in colon cancer via the TGF-β and SMAD3 signaling pathways. PMID:28454433

A novel missense mutation in the HECT domain of NEDD4L identified in a girl with periventricular nodular heterotopia, polymicrogyria and cleft palate.

PubMed

Kato, Koji; Miya, Fuyuki; Hori, Ikumi; Ieda, Daisuke; Ohashi, Kei; Negishi, Yutaka; Hattori, Ayako; Okamoto, Nobuhiko; Kato, Mitsuhiro; Tsunoda, Tatsuhiko; Yamasaki, Mami; Kanemura, Yonehiro; Kosaki, Kenjiro; Saitoh, Shinji

2017-09-01

We identified a novel de novo heterozygous missense mutation in the NEDD4L gene (NM_015277: c.2617G>A; p.Glu873Lys) through whole-exome sequencing in a 3-year-old girl showing severe global developmental delay, infantile spasms, cleft palate, periventricular nodular heterotopia and polymicrogyria. Mutations in the HECT domain of NEDD4L have been reported in patients with a neurodevelopmental disorder along with similar brain malformations. All patients reported with NEDD4L HECT domain mutations showed periventricular nodular heterotopia, and most had seizures, cortex anomalies, cleft palate and syndactyly. The unique constellation of clinical features in patients with NEDD4L mutations might help clinically distinguish them from patients with other genetic mutations including FLNA, which is a well-known causative gene of periventricular nodular heterotopia. Although mutations in the HECT domain of NEDD4L that lead to AKT-mTOR pathway deregulation in forced expression system were reported, our western blot analysis did not show an increased level of AKT-mTOR activity in lymphoblastoid cell lines (LCLs) derived from the patient. In contrast to the forced overexpression system, AKT-mTOR pathway deregulation in LCLs derived from our patient seems to be subtle.

Epigenetic Deregulation of MicroRNAs in Rhabdomyosarcoma and Neuroblastoma and Translational Perspectives

PubMed Central

Romania, Paolo; Bertaina, Alice; Bracaglia, Giorgia; Locatelli, Franco; Fruci, Doriana; Rota, Rossella

2012-01-01

Gene expression control mediated by microRNAs and epigenetic remodeling of chromatin are interconnected processes often involved in feedback regulatory loops, which strictly guide proper tissue differentiation during embryonal development. Altered expression of microRNAs is one of the mechanisms leading to pathologic conditions, such as cancer. Several lines of evidence pointed to epigenetic alterations as responsible for aberrant microRNA expression in human cancers. Rhabdomyosarcoma and neuroblastoma are pediatric cancers derived from cells presenting features of skeletal muscle and neuronal precursors, respectively, blocked at different stages of differentiation. Consistently, tumor cells express tissue markers of origin but are unable to terminally differentiate. Several microRNAs playing a key role during tissue differentiation are often epigenetically downregulated in rhabdomyosarcoma and neuroblastoma and behave as tumor suppressors when re-expressed. Recently, inhibition of epigenetic modulators in adult tumors has provided encouraging results causing re-expression of anti-tumor master gene pathways. Thus, a similar approach could be used to correct the aberrant epigenetic regulation of microRNAs in rhabdomyosarcoma and neuroblastoma. The present review highlights the current insights on epigenetically deregulated microRNAs in rhabdomyosarcoma and neuroblastoma and their role in tumorigenesis and developmental pathways. The translational clinical implications and challenges regarding modulation of epigenetic chromatin remodeling/microRNAs interconnections are also discussed. PMID:23443118

Deregulation of E2-EPF Ubiquitin Carrier Protein in Papillary Renal Cell Carcinoma

PubMed Central

Roos, Frederik C.; Evans, Andrew J.; Brenner, Walburgis; Wondergem, Bill; Klomp, Jeffery; Heir, Pardeep; Roche, Olga; Thomas, Christian; Schimmel, Heiko; Furge, Kyle A.; Teh, Bin T.; Thüroff, Joachim W.; Hampel, Christian; Ohh, Michael

2011-01-01

Molecular pathways associated with pathogenesis of sporadic papillary renal cell carcinoma (PRCC), the second most common form of kidney cancer, are poorly understood. We analyzed primary tumor specimens from 35 PRCC patients treated by nephrectomy via gene expression analysis and tissue microarrays constructed from an additional 57 paraffin-embedded PRCC samples via immunohistochemistry. Gene products were validated and further studied by Western blot analyses using primary PRCC tumor samples and established renal cell carcinoma cell lines, and potential associations with pathologic variables and survival in 27 patients with follow-up information were determined. We show that the expression of E2-EPF ubiquitin carrier protein, which targets the principal negative regulator of hypoxia-inducible factor (HIF), von Hippel-Lindau protein, for proteasome-dependent degradation, is markedly elevated in the majority of PRCC tumors exhibiting increased HIF1α expression, and is associated with poor prognosis. In addition, we identified multiple hypoxia-responsive elements within the E2-EPF promoter, and for the first time we demonstrated that E2-EPF is a hypoxia-inducible gene directly regulated via HIF1. These findings reveal deregulation of the oxygen-sensing pathway impinging on the positive feedback mechanism of HIF1-mediated regulation of E2-EPF in PRCC. PMID:21281817

The Fanconi anemia pathway requires FAA phosphorylation and FAA/FAC nuclear accumulation

PubMed Central

Yamashita, Takayuki; Kupfer, Gary M.; Naf, Dieter; Suliman, Ahmed; Joenje, Hans; Asano, Shigetaka; D’Andrea, Alan D.

1998-01-01

Fanconi anemia (FA) is an autosomal recessive cancer susceptibility syndrome with at least eight complementation groups (A–H). Two FA genes, corresponding to complementation groups A and C, have been cloned, but the function of the FAA and FAC proteins remains unknown. We have recently shown that the FAA and FAC proteins bind and form a nuclear complex. In the current study, we analyzed the FAA and FAC proteins in normal lymphoblasts and lymphoblasts from multiple FA complementation groups. In contrast to normal controls, FA cells derived from groups A, B, C, E, F, G, and H were defective in the formation of the FAA/FAC protein complex, the phosphorylation of the FAA protein, and the accumulation of the FAA/FAC protein complex in the nucleus. These biochemical events seem to define a signaling pathway required for the maintenance of genomic stability and normal hematopoiesis. Our results support the idea that multiple gene products cooperate in the FA Pathway. PMID:9789045

Streptococcus pyogenes Endopeptidase O Contributes to Evasion from Complement-mediated Bacteriolysis via Binding to Human Complement Factor C1q*

PubMed Central

Honda-Ogawa, Mariko; Sumitomo, Tomoko; Mori, Yasushi; Hamd, Dalia Talat; Ogawa, Taiji; Yamaguchi, Masaya; Nakata, Masanobu; Kawabata, Shigetada

2017-01-01

Streptococcus pyogenes secretes various virulence factors for evasion from complement-mediated bacteriolysis. However, full understanding of the molecules possessed by this organism that interact with complement C1q, an initiator of the classical complement pathway, remains elusive. In this study, we identified an endopeptidase of S. pyogenes, PepO, as an interacting molecule, and investigated its effects on complement immunity and pathogenesis. Enzyme-linked immunosorbent assay and surface plasmon resonance analysis findings revealed that S. pyogenes recombinant PepO bound to human C1q in a concentration-dependent manner under physiological conditions. Sites of inflammation are known to have decreased pH levels, thus the effects of PepO on bacterial evasion from complement immunity was analyzed in a low pH condition. Notably, under low pH conditions, PepO exhibited a higher affinity for C1q as compared with IgG, and PepO inhibited the binding of IgG to C1q. In addition, pepO deletion rendered S. pyogenes more susceptible to the bacteriocidal activity of human serum. Also, observations of the morphological features of the pepO mutant strain (ΔpepO) showed damaged irregular surfaces as compared with the wild-type strain (WT). WT-infected tissues exhibited greater severity and lower complement activity as compared with those infected by ΔpepO in a mouse skin infection model. Furthermore, WT infection resulted in a larger accumulation of C1q than that with ΔpepO. Our results suggest that interaction of S. pyogenes PepO with C1q interferes with the complement pathway, which enables S. pyogenes to evade complement-mediated bacteriolysis under acidic conditions, such as seen in inflammatory sites. PMID:28154192

Human Properdin Opsonizes Nanoparticles and Triggers a Potent Pro-inflammatory Response by Macrophages without Involving Complement Activation

PubMed Central

Kouser, Lubna; Paudyal, Basudev; Kaur, Anuvinder; Stenbeck, Gudrun; Jones, Lucy A.; Abozaid, Suhair M.; Stover, Cordula M.; Flahaut, Emmanuel; Sim, Robert B.; Kishore, Uday

2018-01-01

Development of nanoparticles as tissue-specific drug delivery platforms can be considerably influenced by the complement system because of their inherent pro-inflammatory and tumorigenic consequences. The complement activation pathways, and its recognition subcomponents, can modulate clearance of the nanoparticles and subsequent inflammatory response and thus alter the intended translational applications. Here, we report, for the first time, that human properdin, an upregulator of the complement alternative pathway, can opsonize functionalized carbon nanotubes (CNTs) via its thrombospondin type I repeat (TSR) 4 and 5. Binding of properdin and TSR4+5 is likely to involve charge pattern/polarity recognition of the CNT surface since both carboxymethyl cellulose-coated carbon nanotubes (CMC-CNT) and oxidized (Ox-CNT) bound these proteins well. Properdin enhanced the uptake of CMC-CNTs by a macrophage cell line, THP-1, mounting a robust pro-inflammatory immune response, as revealed by qRT-PCR, multiplex cytokine array, and NF-κB nuclear translocation analyses. Properdin can be locally synthesized by immune cells in an inflammatory microenvironment, and thus, its interaction with nanoparticles is of considerable importance. In addition, recombinant TSR4+5 coated on the CMC-CNTs inhibited complement consumption by CMC-CNTs, suggesting that nanoparticle decoration with TSR4+5, can be potentially used as a complement inhibitor in a number of pathological contexts arising due to exaggerated complement activation. PMID:29483907

Crosstalk between Hippo signalling and miRNAs in tumour progression.

PubMed

Li, Nianshuang; Xie, Chuan; Lu, Nonghua

2017-04-01

The Hippo signalling pathway co-ordinately modulates cell regeneration and organ size, and its deregulation contributes to tumorigenesis through many cellular processes, including overproliferation, apoptosis resistance and cell migration. Recent discoveries have shed new light on how microRNAs (miRNAs) are closely linked to the Hippo pathway in tumour progression. Hippo signalling has been reported to affect widespread miRNA biogenesis. In turn, several miRNAs regulate Hippo signalling, which contributes to carcinogenesis. This article will provide an overview of the crosstalk between Hippo signalling and miRNAs in the development of cancer and further appraise potential targets for therapeutic intervention. © 2016 Federation of European Biochemical Societies.

Characterization and expression analysis of a complement component gene in sea cucumber ( Apostichopus japonicus)

NASA Astrophysics Data System (ADS)

Chen, Zhong; Zhou, Zunchun; Yang, Aifu; Dong, Ying; Guan, Xiaoyan; Jiang, Bei; Wang, Bai

2015-12-01

The complement system plays a crucial role in the innate immune system of animals. It can be activated by distinct yet overlapping classical, alternative and lectin pathways. In the alternative pathway, complement factor B (Bf) serves as the catalytic subunit of complement component 3 (C3) convertase, which plays the central role among three activation pathways. In this study, the Bf gene in sea cucumber ( Apostichopus japonicus), termed AjBf, was obtained by rapid amplification of cDNA ends (RACE). The full-length cDNA of AjBf was 3231 bp in length barring the poly (A) tail. It contained an open reading frame (ORF) of 2742 bp encoding 913 amino acids, a 105 bp 5'-UTR (5'-terminal untranslated region) and a 384 bp 3'-UTR. AjBf was a mosaic protein with six CCP (complement control protein) domains, a VWA (von Willebrand factor A) domain, and a serine protease domain. The deduced molecular weight of AjBf protein was 101 kDa. Quantitative real time PCR (qRT-PCR) analysis indicated that the expression level of AjBf in A. japonicus was obviously higher at larval stage than that at embryonic stage. Expression detection in different tissues showed that AjBf expressed higher in coelomocytes than in other four tissues. In addation, AjBf expression in different tissues was induced significantly after LPS or PolyI:C challenge. These results indicated that AjBf plays an important role in immune responses to pathogen infection.

The Role of Complement in Cnidarian-Dinoflagellate Symbiosis and Immune Challenge in the Sea Anemone Aiptasia pallida

PubMed Central

Poole, Angela Z.; Kitchen, Sheila A.; Weis, Virginia M.

2016-01-01

The complement system is an innate immune pathway that in vertebrates, is responsible for initial recognition and ultimately phagocytosis and destruction of microbes. Several complement molecules including C3, Factor B, and mannose binding lectin associated serine proteases (MASP) have been characterized in invertebrates and while most studies have focused on their conserved role in defense against pathogens, little is known about their role in managing beneficial microbes. The purpose of this study was to (1) characterize complement pathway genes in the symbiotic sea anemone Aiptasia pallida, (2) investigate the evolution of complement genes in invertebrates, and (3) examine the potential dual role of complement genes Factor B and MASP in the onset and maintenance of cnidarian-dinoflagellate symbiosis and immune challenge using qPCR based studies. The results demonstrate that A. pallida has multiple Factor B genes (Ap_Bf-1, Ap_Bf-2a, and Ap_Bf-2b) and one MASP gene (Ap_MASP). Phylogenetic analysis indicates that the evolutionary history of complement genes is complex, and there have been many gene duplications or gene loss events, even within members of the same phylum. Gene expression analyses revealed a potential role for complement in both onset and maintenance of cnidarian-dinoflagellate symbiosis and immune challenge. Specifically, Ap_Bf-1 and Ap_MASP are significantly upregulated in the light at the onset of symbiosis and in response to challenge with the pathogen Serratia marcescens suggesting that they play a role in the initial recognition of both beneficial and harmful microbes. Ap_Bf-2b in contrast, was generally downregulated during the onset and maintenance of symbiosis and in response to challenge with S. marcescens. Therefore, the exact role of Ap_Bf-2b in response to microbes remains unclear, but the results suggest that the presence of microbes leads to repressed expression. Together, these results indicate functional divergence between Ap_Bf-1 and Ap_Bf-2b, and that Ap_Bf-1 and Ap_MASP may be functioning together in an ancestral hybrid of the lectin and alternative complement pathways. Overall, this study provides information on the role of the complement system in a basal metazoan and its role in host-microbe interactions. PMID:27148208

The Role of Complement in Cnidarian-Dinoflagellate Symbiosis and Immune Challenge in the Sea Anemone Aiptasia pallida.

PubMed

Poole, Angela Z; Kitchen, Sheila A; Weis, Virginia M

2016-01-01

The complement system is an innate immune pathway that in vertebrates, is responsible for initial recognition and ultimately phagocytosis and destruction of microbes. Several complement molecules including C3, Factor B, and mannose binding lectin associated serine proteases (MASP) have been characterized in invertebrates and while most studies have focused on their conserved role in defense against pathogens, little is known about their role in managing beneficial microbes. The purpose of this study was to (1) characterize complement pathway genes in the symbiotic sea anemone Aiptasia pallida, (2) investigate the evolution of complement genes in invertebrates, and (3) examine the potential dual role of complement genes Factor B and MASP in the onset and maintenance of cnidarian-dinoflagellate symbiosis and immune challenge using qPCR based studies. The results demonstrate that A. pallida has multiple Factor B genes (Ap_Bf-1, Ap_Bf-2a, and Ap_Bf-2b) and one MASP gene (Ap_MASP). Phylogenetic analysis indicates that the evolutionary history of complement genes is complex, and there have been many gene duplications or gene loss events, even within members of the same phylum. Gene expression analyses revealed a potential role for complement in both onset and maintenance of cnidarian-dinoflagellate symbiosis and immune challenge. Specifically, Ap_Bf-1 and Ap_MASP are significantly upregulated in the light at the onset of symbiosis and in response to challenge with the pathogen Serratia marcescens suggesting that they play a role in the initial recognition of both beneficial and harmful microbes. Ap_Bf-2b in contrast, was generally downregulated during the onset and maintenance of symbiosis and in response to challenge with S. marcescens. Therefore, the exact role of Ap_Bf-2b in response to microbes remains unclear, but the results suggest that the presence of microbes leads to repressed expression. Together, these results indicate functional divergence between Ap_Bf-1 and Ap_Bf-2b, and that Ap_Bf-1 and Ap_MASP may be functioning together in an ancestral hybrid of the lectin and alternative complement pathways. Overall, this study provides information on the role of the complement system in a basal metazoan and its role in host-microbe interactions.

Trichinella spiralis Calreticulin Binds Human Complement C1q As an Immune Evasion Strategy.

PubMed

Zhao, Limei; Shao, Shuai; Chen, Yi; Sun, Ximeng; Sun, Ran; Huang, Jingjing; Zhan, Bin; Zhu, Xinping

2017-01-01

As a multicellular parasitic nematode, Trichinella spiralis regulates host immune responses by producing a variety of immunomodulatory molecules to escape from host immune attack, but the mechanisms underlying the immune evasion are not well understood. Here, we identified that T. spiralis calreticulin ( Ts -CRT), a Ca 2+ -binding protein, facilitated T. spiralis immune evasion by interacting with the first component of human classical complement pathway, C1q. In the present study, Ts -CRT was found to be expressed on the surface of different developmental stages of T. spiralis as well as in the secreted products of adult and muscle larval worms. Functional analysis identified that Ts -CRT was able to bind to human C1q, resulting in the inhibition of C1q-initiated complement classical activation pathway reflected by reduced C4/C3 generation and C1q-dependent lysis of antibody-sensitized sheep erythrocytes. Moreover, recombinant Ts -CRT (r Ts -CRT) binding to C1q suppressed C1q-induced THP-1-derived macrophages chemotaxis and reduced monocyte-macrophages release of reactive oxygen intermediates (ROIs). Blocking Ts -CRT on the surface of newborn larvae (NBL) of T. spiralis with anti- Ts -CRT antibody increased the C1q-mediated adherence of monocyte-macrophages to larvae and impaired larval infectivity. All of these results suggest that T. spiralis -expressed Ts -CRT plays crucial roles in T. spiralis immune evasion and survival in host mostly by directly binding to host complement C1q, which not only reduces C1q-mediated activation of classical complement pathway but also inhibits the C1q-induced non-complement activation of macrophages.

Trichinella spiralis Calreticulin Binds Human Complement C1q As an Immune Evasion Strategy

PubMed Central

Zhao, Limei; Shao, Shuai; Chen, Yi; Sun, Ximeng; Sun, Ran; Huang, Jingjing; Zhan, Bin; Zhu, Xinping

2017-01-01

As a multicellular parasitic nematode, Trichinella spiralis regulates host immune responses by producing a variety of immunomodulatory molecules to escape from host immune attack, but the mechanisms underlying the immune evasion are not well understood. Here, we identified that T. spiralis calreticulin (Ts-CRT), a Ca2+-binding protein, facilitated T. spiralis immune evasion by interacting with the first component of human classical complement pathway, C1q. In the present study, Ts-CRT was found to be expressed on the surface of different developmental stages of T. spiralis as well as in the secreted products of adult and muscle larval worms. Functional analysis identified that Ts-CRT was able to bind to human C1q, resulting in the inhibition of C1q-initiated complement classical activation pathway reflected by reduced C4/C3 generation and C1q-dependent lysis of antibody-sensitized sheep erythrocytes. Moreover, recombinant Ts-CRT (rTs-CRT) binding to C1q suppressed C1q-induced THP-1-derived macrophages chemotaxis and reduced monocyte–macrophages release of reactive oxygen intermediates (ROIs). Blocking Ts-CRT on the surface of newborn larvae (NBL) of T. spiralis with anti-Ts-CRT antibody increased the C1q-mediated adherence of monocyte–macrophages to larvae and impaired larval infectivity. All of these results suggest that T. spiralis-expressed Ts-CRT plays crucial roles in T. spiralis immune evasion and survival in host mostly by directly binding to host complement C1q, which not only reduces C1q-mediated activation of classical complement pathway but also inhibits the C1q-induced non-complement activation of macrophages. PMID:28620388

Defining Causative Factors Contributing in the Activation of Hedgehog Signaling in Diffuse Large B-Cell Lymphoma

PubMed Central

Ramirez, Elisa; Singh, Rajesh R; Kunkalla, Kranthi; Liu, Yadong; Qu, Changju; Cain, Christine; Multani, Asha S.; Lennon, Patrick A; Jackacky, Jared; Ho, Michael; Dawud, Sity; Gu, Jun; Yang, Su; Hu, Peter C; Vega, Francisco

2012-01-01

Hedgehog (Hh) signaling pathway is activated in diffuse large B-cell lymphoma (DLBCL). Genetic abnormalities that explain activation of Hh signaling in DLBCL are unknown. We investigate the presence of amplifications of Hh genes that might result in activation of this pathway in DLBCL. Our data showed few extra copies of GLI1 and SMO due to chromosomal aneuploidies in a subset of DLBCL cell lines. We also showed that pharmacologic inhibition of PI3K/AKT and NF-KB pathways resulted in decreased expression of GLI1 and Hh ligands. In conclusion, our data support the hypothesis that aberrant activation of Hh signaling in DLBCL mainly results from integration of deregulated oncogenic signaling inputs converging into Hh signaling. PMID:22809693

Gene Variations in the Protein C and Fibrinolytic Pathway: Relevance for Severity and Outcome in Pediatric Sepsis.

PubMed

Boeddha, Navin P; Emonts, Marieke; Cnossen, Marjon H; de Maat, Moniek P; Leebeek, Frank W; Driessen, Gertjan J; Hazelzet, Jan A

2017-02-01

The host response to infection involves complex interplays between inflammation, coagulation, and fibrinolysis. Deregulation of hemostasis and fibrinolysis are major causes of critical illness and important determinants of outcome in severe sepsis. The hemostatic responses to infection vary widely between individuals, and are in part explained by polymorphisms in genes responsible for the protein C and fibrinolytic pathway. This review gives an overview of genetic polymorphisms in the protein C and fibrinolytic pathway associated with susceptibility and severity of pediatric sepsis. In addition, genetic polymorphisms associated with adult sepsis and other pediatric thromboembolic disorders are discussed, as these polymorphisms might be candidates for future molecular genetic research in pediatric sepsis. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Deposition of mannose-binding lectin and ficolins and activation of the lectin pathway of complement on the surface of polyurethane tubing used for cardiopulmonary bypass.

PubMed

Eppa, Łukasz; Pągowska-Klimek, Izabela; Świerzko, Anna S; Moll, Maciej; Krajewski, Wojciech R; Cedzyński, Maciej

2018-04-01

The artificial surface used for cardiopulmonary bypass (CPB) is a crucial factor activating the complement system and thus contributing to the generation of a systemic inflammatory response. The activation of classical and alternative pathways on this artificial surface is well known. In contrast, lectin pathway (LP) activation has not been fully investigated, although noted during CPB in several studies. Moreover, we have recently proved the contribution of the LP to the generation of the systemic inflammatory response syndrome after pediatric cardiac surgery. The aim of this study was to assess LP-mediated complement activation on the surface of polyurethane CPB circuit tubing (noncoated Chalice ® ), used for CPB procedures in children with congenital heart disease. We found deposition of mannose-binding lectin, ficolin-1, -2, and -3 on the surface of unused tubing and on tubing used for CPB from a small minority of patients. Furthermore, we observed deposition of complement C4 activation products on tubing used for CPB and previously unused tubing after incubation with normal serum. The latter finding indicates LP activation in vitro on the polyurethane surface. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1202-1208, 2018. © 2017 Wiley Periodicals, Inc.

Genetic variation: effect on prostate cancer

PubMed Central

Sissung, Tristan M.; Price, Douglas K.; Del Re, Marzia; Ley, Ariel M.; Giovannetti, Elisa; Danesi, Romano

2014-01-01

Summary The crucial role of androgens in the development of prostate cancer is well established. The aim of this review is to examine the role of constitutional (germline) and tumor-specific (somatic) polymorphisms within important regulatory genes of prostate cancer. These include genes encoding enzymes of the androgen biosynthetic pathway, the androgen receptor gene, genes that encode proteins of the signal transduction pathways that may have a role in disease progression and survival, and genes involved in prostate cancer angiogenesis. Characterization of deregulated pathways critical to cancer cell growth have lead to the development of new treatments, including the CYP17 inhibitor abiraterone and clinical trials using novel drugs that are ongoing or recently completed [1]. The pharmacogenetics of the drugs used to treat prostate cancer will also be addressed. This review will define how germline polymorphisms are known affect a multitude of pathways, and therefore phenotypes, in prostate cancer etiology, progression, and treatment. PMID:25199985

RAS oncogene-mediated deregulation of the transcriptome: from molecular signature to function.

PubMed

Schäfer, Reinhold; Sers, Christine

2011-01-01

Transcriptome analysis of cancer cells has developed into a standard procedure to elucidate multiple features of the malignant process and to link gene expression to clinical properties. Gene expression profiling based on microarrays provides essentially correlative information and needs to be transferred to the functional level in order to understand the activity and contribution of individual genes or sets of genes as elements of the gene signature. To date, there exist significant gaps in the functional understanding of gene expression profiles. Moreover, the processes that drive the profound transcriptional alterations that characterize cancer cells remain mainly elusive. We have used pathway-restricted gene expression profiles derived from RAS oncogene-transformed cells and from RAS-expressing cancer cells to identify regulators downstream of the MAPK pathway.We describe the role of epigenetic regulation exemplified by the control of several immune genes in generic cell lines and colorectal cancer cells, particularly the functional interaction between signaling and DNA methylation. Moreover, we assess the role of the architectural transcription factor high mobility AT-hook 2 (HMGA2) as a regulator of the RAS-responsive transcriptome in ovarian epithelial cells. Finally, we describe an integrated approach combining pathway interference in colorectal cancer cells, gene expression profiling and computational analysis of regulatory elements of deregulated target genes. This strategy resulted in the identification of Y-box binding protein 1 (YBX1) as a regulator of MAPK-dependent proliferation and gene expression. The implications for a therapeutic application of HMGA2 gene silencing and the role of YBX1 as a prognostic factor are discussed.

Disruption of SF3B1 results in deregulated expression and splicing of key genes and pathways in myelodysplastic syndrome hematopoietic stem and progenitor cells.

PubMed

Dolatshad, H; Pellagatti, A; Fernandez-Mercado, M; Yip, B H; Malcovati, L; Attwood, M; Przychodzen, B; Sahgal, N; Kanapin, A A; Lockstone, H; Scifo, L; Vandenberghe, P; Papaemmanuil, E; Smith, C W J; Campbell, P J; Ogawa, S; Maciejewski, J P; Cazzola, M; Savage, K I; Boultwood, J

2015-05-01

The splicing factor SF3B1 is the most commonly mutated gene in the myelodysplastic syndrome (MDS), particularly in patients with refractory anemia with ring sideroblasts (RARS). We investigated the functional effects of SF3B1 disruption in myeloid cell lines: SF3B1 knockdown resulted in growth inhibition, cell cycle arrest and impaired erythroid differentiation and deregulation of many genes and pathways, including cell cycle regulation and RNA processing. MDS is a disorder of the hematopoietic stem cell and we thus studied the transcriptome of CD34(+) cells from MDS patients with SF3B1 mutations using RNA sequencing. Genes significantly differentially expressed at the transcript and/or exon level in SF3B1 mutant compared with wild-type cases include genes that are involved in MDS pathogenesis (ASXL1 and CBL), iron homeostasis and mitochondrial metabolism (ALAS2, ABCB7 and SLC25A37) and RNA splicing/processing (PRPF8 and HNRNPD). Many genes regulated by a DNA damage-induced BRCA1-BCLAF1-SF3B1 protein complex showed differential expression/splicing in SF3B1 mutant cases. This is the first study to determine the target genes of SF3B1 mutation in MDS CD34(+) cells. Our data indicate that SF3B1 has a critical role in MDS by affecting the expression and splicing of genes involved in specific cellular processes/pathways, many of which are relevant to the known RARS pathophysiology, suggesting a causal link.

TFII-I regulates target genes in the PI-3K and TGF-β signaling pathways through a novel DNA binding motif.

PubMed

Segura-Puimedon, Maria; Borralleras, Cristina; Pérez-Jurado, Luis A; Campuzano, Victoria

2013-09-25

General transcription factor (TFII-I) is a multi-functional protein involved in the transcriptional regulation of critical developmental genes, encoded by the GTF2I gene located on chromosome 7q11.23. Haploinsufficiency at GTF2I has been shown to play a major role in the neurodevelopmental features of Williams-Beuren syndrome (WBS). Identification of genes regulated by TFII-I is thus critical to detect molecular determinants of WBS as well as to identify potential new targets for specific pharmacological interventions, which are currently absent. We performed a microarray screening for transcriptional targets of TFII-I in cortex and embryonic cells from Gtf2i mutant and wild-type mice. Candidate genes with altered expression were verified using real-time PCR. A novel motif shared by deregulated genes was found and chromatin immunoprecipitation assays in embryonic fibroblasts were used to document in vitro TFII-I binding to this motif in the promoter regions of deregulated genes. Interestingly, the PI3K and TGFβ signaling pathways were over-represented among TFII-I-modulated genes. In this study we have found a highly conserved DNA element, common to a set of genes regulated by TFII-I, and identified and validated novel in vivo neuronal targets of this protein affecting the PI3K and TGFβ signaling pathways. Overall, our data further contribute to unravel the complexity and variability of the different genetic programs orchestrated by TFII-I. © 2013 Elsevier B.V. All rights reserved.

Deregulated expression of p16INK4a and p53 pathway members in benign and malignant myoepithelial tumours of the salivary glands.

PubMed

Vékony, H; Röser, K; Löning, T; Raaphorst, F M; Leemans, C R; Van der Waal, I; Bloemena, E

2008-12-01

Myoepithelial salivary gland tumours are uncommon and follow an unpredictable biological course. The aim was to examine their molecular background to acquire a better understanding of their clinical behaviour. Expression of protein (E2F1, p16(INK4a), p53, cyclin D1, Ki67 and Polycomb group proteins BMI-1, MEL-18 and EZH2) was investigated in 49 benign and 30 primary malignant myoepithelial tumours and five histologically benign recurrences by immunohistochemistry and the findings correlated with histopathological characteristics. Benign tumours showed a higher percentage of cells with expression of p16(INK4a) pathway members [p16(INK4a) and E2F1 (both P < 0.001), and cyclin D1, P = 0.002] compared with normal salivary gland. Furthermore, malignant tumours expressed p53 (P = 0.003) and EZH2 (P = 0.09) in a higher percentage. Recurrences displayed more p53 + tumour cells (P = 0.02) than benign primaries. Amongst the benign tumours, the clear cell type had the highest proliferation fraction (P = 0.05) and a higher percentage of EZH2 was detected in the plasmacytoid cell type (P = 0.002). This study is the first to demonstrate that deregulation of the p16(INK4a) senescence pathway is involved in the development of myoepithelial tumours. We propose that additional inactivation of p53 in malignant primaries and benign recurrences contributes to myoepithelial neoplastic transformation and aggressive tumour growth.

Molecular aspects of diabetes mellitus: Resistin, microRNA, and exosome.

PubMed

Saeedi Borujeni, Mohammad Javad; Esfandiary, Ebrahim; Taheripak, Gholamreza; Codoñer-Franch, Pilar; Alonso-Iglesias, Eulalia; Mirzaei, Hamed

2018-02-01

Diabetes mellitus (DM) is known as one of important common endocrine disorders which could due to deregulation of a variety of cellular and molecular pathways. A large numbers studies indicated that various pathogenesis events including mutation, serin phosphorylation, and increasing/decreasing expression of many genes could contribute to initiation and progression of DM. Insulin resistance is one of important factors which could play critical roles in DM pathogenesis. It has been showed that insulin resistance via targeting a sequence of cellular and molecular pathways (eg, PI3 kinases, PPARγ co-activator-1, microRNAs, serine/threonine kinase Akt, and serin phosphorylation) could induce DM. Among of various factors involved in DM pathogenesis, microRNAs, and exosomes have been emerged as effective factors in initiation and progression of DM. A variety of studies indicated that deregulation of these molecules could change behavior of various types of cells and contribute to progression of DM. Resistin is other main factor which is known as signal molecule involved in insulin resistance. Multiple lines evidence indicated that resistin exerts its effects via affecting on glucose metabolism, inhibition of fatty acid uptake and metabolism with affecting on a variety of targets such as CD36, fatty acid transport protein 1, Acetyl-CoA carboxylase, and AMP-activated protein kinase. Here, we summarized various molecular aspects are associated with DM particularly the molecular pathways involved in insulin resistance and resistin in DM. Moreover, we highlighted exosomes and microRNAs as effective players in initiation and progression of DM. © 2017 Wiley Periodicals, Inc.

Drug-Path: a database for drug-induced pathways

PubMed Central

Zeng, Hui; Cui, Qinghua

2015-01-01

Some databases for drug-associated pathways have been built and are publicly available. However, the pathways curated in most of these databases are drug-action or drug-metabolism pathways. In recent years, high-throughput technologies such as microarray and RNA-sequencing have produced lots of drug-induced gene expression profiles. Interestingly, drug-induced gene expression profile frequently show distinct patterns, indicating that drugs normally induce the activation or repression of distinct pathways. Therefore, these pathways contribute to study the mechanisms of drugs and drug-repurposing. Here, we present Drug-Path, a database of drug-induced pathways, which was generated by KEGG pathway enrichment analysis for drug-induced upregulated genes and downregulated genes based on drug-induced gene expression datasets in Connectivity Map. Drug-Path provides user-friendly interfaces to retrieve, visualize and download the drug-induced pathway data in the database. In addition, the genes deregulated by a given drug are highlighted in the pathways. All data were organized using SQLite. The web site was implemented using Django, a Python web framework. Finally, we believe that this database will be useful for related researches. Database URL: http://www.cuilab.cn/drugpath PMID:26130661

Drug-Path: a database for drug-induced pathways.

PubMed

Zeng, Hui; Qiu, Chengxiang; Cui, Qinghua

2015-01-01

Some databases for drug-associated pathways have been built and are publicly available. However, the pathways curated in most of these databases are drug-action or drug-metabolism pathways. In recent years, high-throughput technologies such as microarray and RNA-sequencing have produced lots of drug-induced gene expression profiles. Interestingly, drug-induced gene expression profile frequently show distinct patterns, indicating that drugs normally induce the activation or repression of distinct pathways. Therefore, these pathways contribute to study the mechanisms of drugs and drug-repurposing. Here, we present Drug-Path, a database of drug-induced pathways, which was generated by KEGG pathway enrichment analysis for drug-induced upregulated genes and downregulated genes based on drug-induced gene expression datasets in Connectivity Map. Drug-Path provides user-friendly interfaces to retrieve, visualize and download the drug-induced pathway data in the database. In addition, the genes deregulated by a given drug are highlighted in the pathways. All data were organized using SQLite. The web site was implemented using Django, a Python web framework. Finally, we believe that this database will be useful for related researches. © The Author(s) 2015. Published by Oxford University Press.

Mutations and Deregulation of Ras/Raf/MEK/ERK and PI3K/PTEN/Akt/mTOR Cascades Which Alter Therapy Response

PubMed Central

McCubrey, James A.; Steelman, Linda S.; Chappell, William H.; Abrams, Stephen L.; Montalto, Giuseppe; Cervello, Melchiorre; Nicoletti, Ferdinando; Fagone, Paolo; Malaponte, Grazia; Mazzarino, Maria C.; Candido, Saverio; Libra, Massimo; Bäsecke, Jörg; Mijatovic, Sanja; Maksimovic-Ivanic, Danijela; Milella, Michele; Tafuri, Agostino; Cocco, Lucio; Evangelisti, Camilla; Chiarini, Francesca; Martelli, Alberto M.

2012-01-01

The Ras/Raf/MEK/ERK and PI3K/PTEN/Akt/mTOR cascades are often activated by genetic alterations in upstream signaling molecules such as receptor tyrosine kinases (RTK). Certain components of these pathways, RAS, NF1, BRAF, MEK1, DUSP5, PP2A, PIK3CA, PIK3R1, PIK3R4, PIK3R5, IRS4, AKT, NFKB1, MTOR, PTEN, TSC1, and TSC2 may also be activated/inactivated by mutations or epigenetic silencing. Upstream mutations in one signaling pathway or even in downstream components of the same pathway can alter the sensitivity of the cells to certain small molecule inhibitors. These pathways have profound effects on proliferative, apoptotic and differentiation pathways. Dysregulation of components of these cascades can contribute to: resistance to other pathway inhibitors, chemotherapeutic drug resistance, premature aging as well as other diseases. This review will first describe these pathways and discuss how genetic mutations and epigenetic alterations can result in resistance to various inhibitors. PMID:23006971

Evidence for possible non-canonical pathway(s) driven early-onset colorectal cancer in India

PubMed Central

Raman, Ratheesh; Kotapalli, Viswakalyan; Adduri, Raju; Gowrishankar, Swarnalata; Bashyam, Leena; Chaudhary, Ajay; Vamsy, Mohana; Patnaik, Sujith; Srinivasulu, Mukta; Sastry, Regulagadda; Rao, Subramanyeshwar; Vasala, Anjayneyulu; Kalidindi, NarasimhaRaju; Pollack, Jonathan; Murthy, Sudha; Bashyam, Murali

2012-01-01

Two genetic instability pathways viz. chromosomal instability, driven primarily by APC mutation induced deregulated Wnt signaling, and microsatellite instability (MSI) caused by mismatch repair (MMR) inactivation, together account for greater than 90% of late-onset colorectal cancer. Our understanding of early-onset sporadic CRC is however comparatively limited. In addition, most seminal studies have been performed in the western population and analyses of tumorigenesis pathway(s) causing CRC in developing nations have been rare. We performed a comparative analysis of early and late-onset CRC from India with respect to common genetic aberrations including Wnt, KRAS and p53 (constituting the classical CRC progression sequence) in addition to MSI. Our results revealed the absence of Wnt and MSI in a significant proportion of early-onset as against late-onset CRC in India. In addition, KRAS mutation frequency was significantly lower in early-onset CRC indicating that a significant proportion of CRC in India may follow tumorigenesis pathways distinct from the classical CRC progression sequence. Our study has therefore revealed the possible existence of non-canonical tumorigenesis pathways in early-onset CRC in India. PMID:23168910

Ulex europaeus agglutinin II (UEA-II) is a novel, potent inhibitor of complement activation.

PubMed

Lekowski, R; Collard, C D; Reenstra, W R; Stahl, G L

2001-02-01

Complement is an important mediator of vascular injury following oxidative stress. We recently demonstrated that complement activation following endothelial oxidative stress is mediated by mannose-binding lectin (MBL) and activation of the lectin complement pathway. Here, we investigated whether nine plant lectins which have a binding profile similar to that of MBL competitively inhibit MBL deposition and subsequent complement activation following human umbilical vein endothelial cell (HUVEC) oxidative stress. HUVEC oxidative stress (1% O(2), 24 hr) significantly increased Ulex europaeus agglutinin II (UEA-II) binding by 72 +/- 9% compared to normoxic cells. UEA-II inhibited MBL binding to HUVEC in a concentration-dependent manner following oxidative stress. Further, MBL inhibited UEA-II binding to HUVEC in a concentration-dependent manner following oxidative stress, suggesting a common ligand. UEA-II (< or = 100 micromol/L) did not attenuate the hemolytic activity, nor did it inhibit C3a des Arg formation from alternative or classical complement pathway-specific hemolytic assays. C3 deposition (measured by ELISA) following HUVEC oxidative stress was inhibited by UEA-II in a concentration-dependent manner (IC(50) = 10 pmol/L). UEA-II inhibited C3 and MBL co-localization (confocal microscopy) in a concentration-dependent manner on HUVEC following oxidative stress (IC(50) approximately 1 pmol/L). Finally, UEA-II significantly inhibited complement-dependent neutrophil chemotaxis, but failed to inhibit fMLP-mediated chemotaxis, following endothelial oxidative stress. These data demonstrate that UEA-II is a novel, potent inhibitor of human MBL deposition and complement activation following human endothelial oxidative stress.

Ulex europaeus agglutinin II (UEA-II) is a novel, potent inhibitor of complement activation

PubMed Central

Lekowski, Robert; Collard, Charles D.; Reenstra, Wende R.; Stahl, Gregory L.

2001-01-01

Complement is an important mediator of vascular injury following oxidative stress. We recently demonstrated that complement activation following endothelial oxidative stress is mediated by mannose-binding lectin (MBL) and activation of the lectin complement pathway. Here, we investigated whether nine plant lectins which have a binding profile similar to that of MBL competitively inhibit MBL deposition and subsequent complement activation following human umbilical vein endothelial cell (HUVEC) oxidative stress. HUVEC oxidative stress (1% O2, 24 hr) significantly increased Ulex europaeus agglutinin II (UEA-II) binding by 72 ± 9% compared to normoxic cells. UEA-II inhibited MBL binding to HUVEC in a concentration-dependent manner following oxidative stress. Further, MBL inhibited UEA-II binding to HUVEC in a concentration-dependent manner following oxidative stress, suggesting a common ligand. UEA-II (≤ 100 μmol/L) did not attenuate the hemolytic activity, nor did it inhibit C3a des Arg formation from alternative or classical complement pathway-specific hemolytic assays. C3 deposition (measured by ELISA) following HUVEC oxidative stress was inhibited by UEA-II in a concentration-dependent manner (IC50 = 10 pmol/L). UEA-II inhibited C3 and MBL co-localization (confocal microscopy) in a concentration-dependent manner on HUVEC following oxidative stress (IC50 ≈ 1 pmol/L). Finally, UEA-II significantly inhibited complement-dependent neutrophil chemotaxis, but failed to inhibit fMLP-mediated chemotaxis, following endothelial oxidative stress. These data demonstrate that UEA-II is a novel, potent inhibitor of human MBL deposition and complement activation following human endothelial oxidative stress. PMID:11266613

FANCJ Helicase Operates in the Fanconi Anemia DNA Repair Pathway and the Response to Replicational Stress

PubMed Central

Wu, Yuliang; Brosh, Robert M.

2009-01-01

Fanconi anemia (FA) is an autosomal recessive disorder characterized by multiple congenital anomalies, progressive bone marrow failure, and high cancer risk. Cells from FA patients exhibit spontaneous chromosomal instability and hypersensitivity to DNA interstrand cross-linking (ICL) agents. Although the precise mechanistic details of the FA/BRCA pathway of ICL-repair are not well understood, progress has been made in the identification of the FA proteins that are required for the pathway. Among the 13 FA complementation groups from which all the FA genes have been cloned, only a few of the FA proteins are predicted to have direct roles in DNA metabolism. One of the more recently identified FA proteins, shown to be responsible for complementation of the FA complementation group J, is the BRCA1 Associated C-terminal Helicase (BACH1, designated FANCJ), originally identified as a protein associated with breast cancer. FANCJ has been proposed to function downstream of FANCD2 monoubiquitination, a critical event in the FA pathway. Evidence supports a role for FANCJ in a homologous recombination (HR) pathway of double strand break (DSB) repair. In this review, we will summarize the current knowledge in terms of FANCJ functions through its enzymatic activities and protein interactions. The molecular roles of FANCJ in DNA repair and the response to replicational stress will be discussed. PMID:19519404

The Surface-Exposed Protein SntA Contributes to Complement Evasion in Zoonotic Streptococcus suis.

PubMed

Deng, Simin; Xu, Tong; Fang, Qiong; Yu, Lei; Zhu, Jiaqi; Chen, Long; Liu, Jiahui; Zhou, Rui

2018-01-01

Streptococcus suis is an emerging zoonotic pathogen causing streptococcal toxic shock like syndrome (STSLS), meningitis, septicemia, and even sudden death in human and pigs. Serious septicemia indicates this bacterium can evade the host complement surveillance. In our previous study, a functionally unknown protein SntA of S. suis has been identified as a heme-binding protein, and contributes to virulence in pigs. SntA can interact with the host antioxidant protein AOP2 and consequently inhibit its antioxidant activity. In the present study, SntA is identified as a cell wall anchored protein that functions as an important player in S. suis complement evasion. The C3 deposition and membrane attack complex (MAC) formation on the surface of sntA -deleted mutant strain Δ sntA are demonstrated to be significantly higher than the parental strain SC-19 and the complementary strain CΔ sntA . The abilities of anti-phagocytosis, survival in blood, and in vivo colonization of Δ sntA are obviously reduced. SntA can interact with C1q and inhibit hemolytic activity via the classical pathway. Complement activation assays reveal that SntA can also directly activate classical and lectin pathways, resulting in complement consumption. These two complement evasion strategies may be crucial for the pathogenesis of this zoonotic pathogen. Concerning that SntA is a bifunctional 2',3'-cyclic nucleotide 2'-phosphodiesterase/3'-nucleotidase in many species of Gram-positive bacteria, these complement evasion strategies may have common biological significance.

Microfibrillar associated protein 4 mfap4 genes in catfish play a novel role in innate immune responses

USDA-ARS?s Scientific Manuscript database

The lectin pathway of the complement system is characterized by two groups of soluble pattern recognition molecules, mannose-binding lectins (MBLs) and ficolins. These molecules recognize and bind carbohydrates in pathogens and activate complement leading to opsonization, leukocyte activation, and d...

Inherited mitochondrial DNA variants can affect complement, inflammation and apoptosis pathways: insights into mitochondrial–nuclear interactions

PubMed Central

Cristina Kenney, M.; Chwa, Marilyn; Atilano, Shari R.; Falatoonzadeh, Payam; Ramirez, Claudio; Malik, Deepika; Tarek, Mohamed; Cáceres-del-Carpio, Javier; Nesburn, Anthony B.; Boyer, David S.; Kuppermann, Baruch D.; Vawter, Marquis; Michal Jazwinski, S.; Miceli, Michael; Wallace, Douglas C.; Udar, Nitin

2014-01-01

Age-related macular degeneration (AMD) is the leading cause of vision loss in developed countries. While linked to genetic polymorphisms in the complement pathway, there are many individuals with high risk alleles that do not develop AMD, suggesting that other ‘modifiers’ may be involved. Mitochondrial (mt) haplogroups, defined by accumulations of specific mtDNA single nucleotide polymorphisms (SNPs) which represent population origins, may be one such modifier. J haplogroup has been associated with high risk for AMD while the H haplogroup is protective. It has been difficult to assign biological consequences for haplogroups so we created human ARPE-19 cybrids (cytoplasmic hybrids), which have identical nuclei but mitochondria of either J or H haplogroups, to investigate their effects upon bioenergetics and molecular pathways. J cybrids have altered bioenergetic profiles compared with H cybrids. Q-PCR analyses show significantly lower expression levels for seven respiratory complex genes encoded by mtDNA. J and H cybrids have significantly altered expression of eight nuclear genes of the alternative complement, inflammation and apoptosis pathways. Sequencing of the entire mtDNA was carried out for all the cybrids to identify haplogroup and non-haplogroup defining SNPs. mtDNA can mediate cellular bioenergetics and expression levels of nuclear genes related to complement, inflammation and apoptosis. Sequencing data suggest that observed effects are not due to rare mtDNA variants but rather the combination of SNPs representing the J versus H haplogroups. These findings represent a paradigm shift in our concepts of mt–nuclear interactions. PMID:24584571

Aneuploidy-dependent massive deregulation of the cellular transcriptome and apparent divergence of the Wnt/beta-catenin signaling pathway in human rectal carcinomas.

PubMed

Grade, Marian; Ghadimi, B Michael; Varma, Sudhir; Simon, Richard; Wangsa, Danny; Barenboim-Stapleton, Linda; Liersch, Torsten; Becker, Heinz; Ried, Thomas; Difilippantonio, Michael J

2006-01-01

To identify genetic alterations underlying rectal carcinogenesis, we used global gene expression profiling of a series of 17 locally advanced rectal adenocarcinomas and 20 normal rectal mucosa biopsies on oligonucleotide arrays. A total of 351 genes were differentially expressed (P < 1.0e-7) between normal rectal mucosa and rectal carcinomas, 77 genes had a >5-fold difference, and 85 genes always had at least a 2-fold change in all of the matched samples. Twelve genes satisfied all three of these criteria. Altered expression of genes such as PTGS2 (COX-2), WNT1, TGFB1, VEGF, and MYC was confirmed, whereas our data for other genes, like PPARD and LEF1, were inconsistent with previous reports. In addition, we found deregulated expression of many genes whose involvement in rectal carcinogenesis has not been reported. By mapping the genomic imbalances in the tumors using comparative genomic hybridization, we could show that DNA copy number gains of recurrently aneuploid chromosome arms 7p, 8q, 13q, 18q, 20p, and 20q correlated significantly with their average chromosome arm expression profile. Taken together, our results show that both the high-level, significant transcriptional deregulation of specific genes and general modification of the average transcriptional activity of genes residing on aneuploid chromosomes coexist in rectal adenocarcinomas.

Aneuploidy-Dependent Massive Deregulation of the Cellular Transcriptome and Apparent Divergence of the Wnt/β-catenin Signaling Pathway in Human Rectal Carcinomas

PubMed Central

Grade, Marian; Ghadimi, B. Michael; Varma, Sudhir; Simon, Richard; Wangsa, Danny; Barenboim-Stapleton, Linda; Liersch, Torsten; Becker, Heinz; Ried, Thomas; Difilippantonio, Michael J.

2016-01-01

To identify genetic alterations underlying rectal carcinogenesis, we used global gene expression profiling of a series of 17 locally advanced rectal adenocarcinomas and 20 normal rectal mucosa biopsies on oligonucleotide arrays. A total of 351 genes were differentially expressed (P < 1.0e–7) between normal rectal mucosa and rectal carcinomas, 77 genes had a >5-fold difference, and 85 genes always had at least a 2-fold change in all of the matched samples. Twelve genes satisfied all three of these criteria. Altered expression of genes such as PTGS2 (COX-2), WNT1, TGFB1, VEGF, and MYC was confirmed, whereas our data for other genes, like PPARD and LEF1, were inconsistent with previous reports. In addition, we found deregulated expression of many genes whose involvement in rectal carcinogenesis has not been reported. By mapping the genomic imbalances in the tumors using comparative genomic hybridization, we could show that DNA copy number gains of recurrently aneuploid chromosome arms 7p, 8q, 13q, 18q, 20p, and 20q correlated significantly with their average chromosome arm expression profile. Taken together, our results show that both the high-level, significant transcriptional deregulation of specific genes and general modification of the average transcriptional activity of genes residing on aneuploid chromosomes coexist in rectal adenocarcinomas. PMID:16397240

Hypothermia mediates age-dependent increase of tau phosphorylation in db/db mice.

PubMed

El Khoury, Noura B; Gratuze, Maud; Petry, Franck; Papon, Marie-Amélie; Julien, Carl; Marcouiller, François; Morin, Françoise; Nicholls, Samantha B; Calon, Frédéric; Hébert, Sébastien S; Marette, André; Planel, Emmanuel

2016-04-01

Accumulating evidence from epidemiological studies suggest that type 2 diabetes is linked to an increased risk of Alzheimer's disease (AD). However, the consequences of type 2 diabetes on AD pathologies, such as tau hyperphosphorylation, are not well understood. Here, we evaluated the impact of type 2 diabetes on tau phosphorylation in db/db diabetic mice aged 4 and 26weeks. We found increased tau phosphorylation at the CP13 epitope correlating with a deregulation of c-Jun. N-terminal kinase (JNK) and Protein Phosphatase 2A (PP2A) in 4-week-old db/db mice. 26-week-old db/db mice displayed tau hyperphosphorylation at multiple epitopes (CP13, AT8, PHF-1), but no obvious change in kinases or phosphatases, no cleavage of tau, and no deregulation of central insulin signaling pathways. In contrast to younger animals, 26-week-old db/db mice were hypothermic and restoration of normothermia rescued phosphorylation at most epitopes. Our results suggest that, at early stages of type 2 diabetes, changes in tau phosphorylation may be due to deregulation of JNK and PP2A, while at later stages hyperphosphorylation is mostly a consequence of hypothermia. These results provide a novel link between diabetes and tau pathology, and underlie the importance of recording body temperature to better understand the relationship between diabetes and AD. Copyright © 2016 Elsevier Inc. All rights reserved.

Deficiency of RITA results in multiple mitotic defects by affecting microtubule dynamics.

PubMed

Steinhäuser, K; Klöble, P; Kreis, N-N; Ritter, A; Friemel, A; Roth, S; Reichel, J M; Michaelis, J; Rieger, M A; Louwen, F; Oswald, F; Yuan, J

2017-04-01

Deregulation of mitotic microtubule (MT) dynamics results in defective spindle assembly and chromosome missegregation, leading further to chromosome instability, a hallmark of tumor cells. RBP-J interacting and tubulin-associated protein (RITA) has been identified as a negative regulator of the Notch signaling pathway. Intriguingly, deregulated RITA is involved in primary hepatocellular carcinoma and other malignant entities. We were interested in the potential molecular mechanisms behind its involvement. We show here that RITA binds to tubulin and localizes to various mitotic MT structures. RITA coats MTs and affects their structures in vitro as well as in vivo. Tumor cell lines deficient of RITA display increased acetylated α-tubulin, enhanced MT stability and reduced MT dynamics, accompanied by multiple mitotic defects, including chromosome misalignment and segregation errors. Re-expression of wild-type RITA, but not RITA Δtub ineffectively binding to tubulin, restores the phenotypes, suggesting that the role of RITA in MT modulation is mediated via its interaction with tubulin. Mechanistically, RITA interacts with tubulin/histone deacetylase 6 (HDAC6) and its suppression decreases the binding of the deacetylase HDAC6 to tubulin/MTs. Furthermore, the mitotic defects and increased MT stability are also observed in RITA -/- mouse embryonic fibroblasts. RITA has thus a novel role in modulating MT dynamics and its deregulation results in erroneous chromosome segregation, one of the major reasons for chromosome instability in tumor cells.

Copper-induced deregulation of microRNA expression in the zebrafish olfactory system

PubMed Central

Wang, Lu; Bammler, Theo K.; Beyer, Richard P.; Gallagher, Evan P.

2016-01-01

Although environmental trace metals, such as copper (Cu), can disrupt normal olfactory function in fish, the underlying molecular mechanisms of metal-induced olfactory injury have not been elucidated. Current research has suggested the involvement of epigenetic modifications. To address this hypothesis, we analyzed microRNA (miRNA) profiles in the olfactory system of Cu-exposed zebrafish. Our data revealed 2, 10, and 28 differentially expressed miRNAs in a dose-response manner corresponding to three increasing Cu concentrations. Numerous deregulated miRNAs were involved in neurogenesis (e.g. let-7, miR-7a, miR-128 and miR-138), indicating a role for Cu-mediated toxicity via interference with neurogenesis processes. Putative gene targets of deregulated miRNAs were identified when interrogating our previously published microarray database, including those involved in cell growth and proliferation, cell death, and cell morphology. Moreover, several miRNAs (e.g. miR-203a, miR-199*, miR-16a, miR-16c, and miR-25) may contribute to decreased mRNA levels of their host genes involved in olfactory signal transduction pathways and other critical neurological processes via a post-transcriptional mechanism. Our findings provide novel insight into the epigenetic regulatory mechanisms of metal-induced neurotoxicity of the fish olfactory system, and identify novel miRNA biomarkers of metal exposures. PMID:23745839

Rituximab fails where eculizumab restores renal function in C3nef-related DDD.

PubMed

Rousset-Rouvière, Caroline; Cailliez, Mathilde; Garaix, Florentine; Bruno, Daniele; Laurent, Daniel; Tsimaratos, Michel

2014-06-01

Dense deposit disease (DDD), a C3 glomerulopathy (C3G), is a rare disease with unfavorable progression towards end-stage kidney disease. The pathogenesis of DDD is due to cytotoxic effects related to acquired or genetic dysregulation of the complement alternative pathway, which is at times accompanied by the production of C3 nephritic factor (C3NeF), an auto-antibody directed against the alternative C3 convertase. Available treatments include plasma exchange, CD20-targeted antibodies, and a terminal complement blockade via the anti-C5 monoclonal antibody eculizumab. We report here the case of an 8-year-old child with C3NeF and refractory DDD who presented with a nephritic syndrome. She tested positive for C3NeF activity; C3 was undetectable. Genetic analyses of the alternative complement pathway were normal. Methylprednisolone pulses and mycophenolate mofetil treatment resulted in complete recovery of renal function and a reduction in proteinuria. Corticosteroids were tapered and then withdrawn. Four months after corticosteroid discontinuation, hematuria and proteinuria recurred, and a renal biopsy confirmed an active DDD with a majority of extracapillary crescents. Despite an increase in immunosuppressive drugs, including methylprednisolone pulses and rituximab therapy, the patient suffered acute renal failure within 3 weeks, requiring dialysis. Eculizumab treatment resulted in a quick and impressive response. Hematuria very quickly resolved, kidney function improved, and no further dialysis was required. The patient received bimonthly eculizumab injections of 600 mg, allowing for normalization of renal function and reduction of proteinuria to <0.5 g per day. Since then, she continues to receive eculizumab. Complement regulation pathway-targeted therapy may be a specific and useful treatment for rapidly progressing DDD prior to the development of glomerulosclerosis. Our data provide evidence supporting the pivotal role of complement alternative pathway abnormalities in C3G with DDD.

Complement opsonization of HIV-1 results in a different intracellular processing pattern and enhanced MHC class I presentation by dendritic cells

PubMed Central

Tjomsland, Veronica; Ellegård, Rada; Burgener, Adam; Mogk, Kenzie; Che, Karlhans F; Westmacott, Garrett; Hinkula, Jorma; Lifson, Jeffrey D; Larsson, Marie

2013-01-01

Induction of optimal HIV-1-specific T-cell responses, which can contribute to controlling viral infection in vivo, depends on antigen processing and presentation processes occurring in DCs. Opsonization can influence the routing of antigen processing and pathways used for presentation. We studied antigen proteolysis and the role of endocytic receptors in MHC class I (MHCI) and II (MHCII) presentation of antigens derived from HIV-1 in human monocyte-derived immature DCs (IDCs) and mature DCs, comparing free and complement opsonized HIV-1 particles. Opsonization of virions promoted MHCI presentation by DCs, indicating that complement opsonization routes more virions toward the MHCI presentation pathway. Blockade of macrophage mannose receptor (MMR) and β7-integrin enhanced MHCI and MHCII presentation by IDCs and mature DCs, whereas the block of complement receptor 3 decreased MHCI and MHCII presentation. In addition, we found that IDC and MDC proteolytic activities were modulated by HIV-1 exposure; complement-opsonized HIV-1 induced an increased proteasome activity in IDCs. Taken together, these findings indicate that endocytic receptors such as MMR, complement receptor 3, and β7-integrin can promote or disfavor antigen presentation probably by routing HIV-1 into different endosomal compartments with distinct efficiencies for degradation of viral antigens and MHCI and MHCII presentation, and that HIV-1 affects the antigen-processing machinery. PMID:23526630

Evidence for a role of Collapsin response mediator protein-2 in signaling pathways that regulate the proliferation of non-neuronal cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tahimic, Candice Ginn T.; Tomimatsu, Nozomi; Nishigaki, Ryuichi

Collapsin response mediator protein-2 or Crmp-2 plays a critical role in the establishment of neuronal polarity. In this study, we present evidence that apart from its functions in neurodevelopment, Crmp-2 is also involved in pathways that regulate the proliferation of non-neuronal cells through its phosphorylation by regulatory proteins. We show that Crmp-2 undergoes dynamic phosphorylation changes in response to contact inhibition-induced quiescence and that hyperphosphorylation of Crmp-2 occurs in a tumor. We further suggest that de-regulation of Crmp-2 phosphorylation levels at certain amino acid residues may lead to aberrant cell proliferation and consequently, tumorigenesis.

Epigenetics of oropharyngeal squamous cell carcinoma: opportunities for novel chemotherapeutic targets.

PubMed

Lindsay, Cameron; Seikaly, Hadi; Biron, Vincent L

2017-01-31

Epigenetic modifications are heritable changes in gene expression that do not directly alter DNA sequence. These modifications include DNA methylation, histone post-translational modifications, small and non-coding RNAs. Alterations in epigenetic profiles cause deregulation of fundamental gene expression pathways associated with carcinogenesis. The role of epigenetics in oropharyngeal squamous cell carcinoma (OPSCC) has recently been recognized, with implications for novel biomarkers, molecular diagnostics and chemotherapeutics. In this review, important epigenetic pathways in human papillomavirus (HPV) positive and negative OPSCC are summarized, as well as the potential clinical utility of this knowledge.This material has never been published and is not currently under evaluation in any other peer-reviewed publication.

Necroptosis and Cancer.

PubMed

Najafov, Ayaz; Chen, Hongbo; Yuan, Junying

2017-04-01

Necroptosis is a programmed lytic cell death pathway, deregulation of which is linked to various inflammatory disorders. Escape from programmed cell death and inflammation play a significant role in cancer, and therefore, investigating the role of necroptosis in cancer has been of high interest. Necroptosis has been shown to promote cancer metastasis and T cells death. Escape from necroptosis via loss of RIPK3 expression is a feature of some cancers. While necroptosis is a promising novel target for cancer therapies, further investigation into its biological role in carcinogenesis is warranted. In this article, we review the recently-identified interplay points between necroptosis and cancer, and outline major biological questions that require further inquiry on the road to targeting this pathway in cancer.

Targeting the adaptive molecular landscape of castration-resistant prostate cancer

PubMed Central

Wyatt, Alexander W; Gleave, Martin E

2015-01-01

Castration and androgen receptor (AR) pathway inhibitors induce profound and sustained responses in advanced prostate cancer. However, the inevitable recurrence is associated with reactivation of the AR and progression to a more aggressive phenotype termed castration-resistant prostate cancer (CRPC). AR reactivation can occur directly through genomic modification of the AR gene, or indirectly via co-factor and co-chaperone deregulation. This mechanistic heterogeneity is further complicated by the stress-driven induction of a myriad of overlapping cellular survival pathways. In this review, we describe the heterogeneous and evolvable molecular landscape of CRPC and explore recent successes and failures of therapeutic strategies designed to target AR reactivation and adaptive survival pathways. We also discuss exciting areas of burgeoning anti-tumour research, and their potential to improve the survival and management of patients with CRPC. PMID:25896606

MarvelD3 regulates the c-Jun N-terminal kinase pathway during eye development in Xenopus

PubMed Central

Vacca, Barbara; Sanchez-Heras, Elena; Steed, Emily; Balda, Maria S.; Ohnuma, Shin-Ichi; Sasai, Noriaki; Mayor, Roberto

2016-01-01

ABSTRACT Ocular morphogenesis requires several signalling pathways controlling the expression of transcription factors and cell-cycle regulators. However, despite a well-known mechanism, the dialogue between those signals and factors remains to be unveiled. Here, we identify a requirement for MarvelD3, a tight junction transmembrane protein, in eye morphogenesis in Xenopus. MarvelD3 depletion led to an abnormally pigmented eye or even an eye-less phenotype, which was rescued by ectopic MarvelD3 expression. Altering MarvelD3 expression led to deregulated expression of cell-cycle regulators and transcription factors required for eye development. The eye phenotype was rescued by increased c-Jun terminal Kinase activation. Thus, MarvelD3 links tight junctions and modulation of the JNK pathway to eye morphogenesis. PMID:27870636

Streptococcus pyogenes Endopeptidase O Contributes to Evasion from Complement-mediated Bacteriolysis via Binding to Human Complement Factor C1q.

PubMed

Honda-Ogawa, Mariko; Sumitomo, Tomoko; Mori, Yasushi; Hamd, Dalia Talat; Ogawa, Taiji; Yamaguchi, Masaya; Nakata, Masanobu; Kawabata, Shigetada

2017-03-10

Streptococcus pyogenes secretes various virulence factors for evasion from complement-mediated bacteriolysis. However, full understanding of the molecules possessed by this organism that interact with complement C1q, an initiator of the classical complement pathway, remains elusive. In this study, we identified an endopeptidase of S. pyogenes , PepO, as an interacting molecule, and investigated its effects on complement immunity and pathogenesis. Enzyme-linked immunosorbent assay and surface plasmon resonance analysis findings revealed that S. pyogenes recombinant PepO bound to human C1q in a concentration-dependent manner under physiological conditions. Sites of inflammation are known to have decreased pH levels, thus the effects of PepO on bacterial evasion from complement immunity was analyzed in a low pH condition. Notably, under low pH conditions, PepO exhibited a higher affinity for C1q as compared with IgG, and PepO inhibited the binding of IgG to C1q. In addition, pepO deletion rendered S. pyogenes more susceptible to the bacteriocidal activity of human serum. Also, observations of the morphological features of the pepO mutant strain (Δ pepO ) showed damaged irregular surfaces as compared with the wild-type strain (WT). WT-infected tissues exhibited greater severity and lower complement activity as compared with those infected by Δ pepO in a mouse skin infection model. Furthermore, WT infection resulted in a larger accumulation of C1q than that with Δ pepO. Our results suggest that interaction of S. pyogenes PepO with C1q interferes with the complement pathway, which enables S. pyogenes to evade complement-mediated bacteriolysis under acidic conditions, such as seen in inflammatory sites. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Characterization of mTOR-Responsive Truncated mRNAs in Cell Proliferation

DTIC Science & Technology

2017-07-01

AWARD NUMBER: W81XWH-16-1-0135 TITLE: Characterization of mTOR-Responsive Truncated mRNAs in Cell Proliferation PRINCIPAL INVESTIGATOR...TITLE AND SUBTITLE 5a. CONTRACT NUMBER Characterization of mTOR-Responsive Truncated mRNAs in Cell Proliferation 5b. GRANT NUMBER 8W1XWH-16-1...Sclerosis Complex (TSC) 1 or 2 gene leads to deregulated mTOR activation and consequent cell proliferation/growth. Thus, studying the mTOR pathway

Mechanisms of NF-κB deregulation in lymphoid malignancies.

PubMed

Krappmann, Daniel; Vincendeau, Michelle

2016-08-01

Deregulations promoting constitutive activation of canonical and non-canonical NF-κB signaling are a common feature of many lymphoid malignancies. Due to their cellular origin and the pivotal role of NF-κB for the normal function of B lymphocytes, B-cell malignancies are particularly prone to genetic aberrations that affect the pathway. Key positive regulators of NF-κB signaling can act as oncogenes that are often prone to chromosomal translocation, amplifications or activating mutations. Negative regulators of NF-κB have tumor suppressor functions and are frequently inactivated either by genomic deletions or point mutations. Whereas some aberrations are found in a variety of different lymphoid malignancies, some oncogenic alterations are very restricted to distinct lymphoma subsets, reflecting the clonal and cellular origin of specific lymphoma entities. NF-κB activation in many lymphoma cells is also driven by the microenvironment or chronic signaling that does not rely on genetic alterations. A number of drugs that target the NF-κB pathway are in preclinical or clinical development, revealing that there will be new options for therapies in the future. Since each lymphoma entity utilizes distinct mechanisms to activate NF-κB, a major challenge is to elucidate the exact pathological processes in order to faithfully predict clinical responses to the different therapeutic approaches. Copyright © 2016 Elsevier Ltd. All rights reserved.

Identification of deregulation of apoptosis and cell cycle in neuroendocrine tumors of the lung via NanoString nCounter expression analysis.

PubMed

Walter, Robert Fred Henry; Werner, Robert; Ting, Saskia; Vollbrecht, Claudia; Theegarten, Dirk; Christoph, Daniel Christian; Schmid, Kurt Werner; Wohlschlaeger, Jeremias; Mairinger, Fabian Dominik

2015-09-22

Neuroendocrine tumors of the lung comprise typical (TC) and atypical carcinoids (AC), large-cell neuroendocrine cancer (LCNEC) and small-cell lung cancer (SCLC). Cell cycle and apoptosis are key pathways of multicellular homeostasis and deregulation of these pathways is associated with cancerogenesis. Sixty representative FFPE-specimens (16 TC, 13 AC, 16 LCNEC and 15 SCLC) were used for mRNA expression analysis using the NanoString technique. Eight genes related to apoptosis and ten genes regulating key points of cell cycle were investigated. ASCL1, BCL2, CASP8, CCNE1, CDK1, CDK2, CDKN1A and CDKN2A showed lower expression in carcinoids compared to carcinomas. In contrast, CCNE1 and CDK6 showed elevated expression in carcinoids compared to carcinomas. The calculated BCL2/BAX ratio showed increasing values from TC to SCLC. Between SCLC and LCNEC CDK2, CDKN1B, CDKN2A and PNN expression was significantly different with higher expression in SCLC. Carcinoids have increased CDK4/6 and CCND1 expression controlling RB1 phosphorylation via this signaling cascade. CDK2 and CCNE1 were increased in carcinomas showing that these use the opposite way to control RB1. BAX and BCL2 are antagonists in regulating apoptosis. BCL2 expression increased over BAX expression with increasing malignancy of the tumor from TC to SCLC.

Temperature sensitivity of phospho-Ser{sup 473}-PKB/AKT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oehler-Jaenne, Christoph; Bueren, Andre O. von; Vuong, Van

2008-10-24

The phospho-PKB/Akt status is often used as surrogate marker to measure activation of the PI3K/Akt/mTOR signal transduction pathway. Though, inconsistencies of the p-Ser{sup 473}-PKB/Akt status have raised doubts in the validity of p-Ser{sup 473}-PKB/Akt phosphorylation as endpoint. Here, we determined that p-Ser{sup 473}-PKB/Akt but not p-Thr{sup 308}-PKB/Akt phosphorylation is highly temperature sensitive. p-Ser{sup 473}-PKB/Akt phosphorylation was rapidly reduced to levels below 50% on exposure to 20-25 deg. C in murine and human cell lines including cells expressing constitutively active PI3K or lacking PTEN. Down-regulation of p-Ser{sup 473}-PKB/Akt was reversible and re-exposure to physiological temperature resulted in increased p-Ser{sup 473}-PKB/Akt phosphorylationmore » levels. Phosphatase activity at low temperature was sustained at 75% baseline level and phosphatase inhibition prevented p-Ser{sup 473}-PKB/Akt dephosphorylation induced by the low temperature shift. Interestingly temperature-dependent deregulation of the p-Ser{sup 473}-PKB/Akt status was also observed in response to irradiation. Thus our data demonstrate that minimal additional stress factors deregulate the PI3K/Akt-survival pathway and the p-Ser{sup 473}-PKB/Akt status as experimental endpoint.« less

Periosteal chondrosarcoma: a histopathological and molecular analysis of a rare chondrosarcoma subtype.

PubMed

Cleven, Arjen H G; Zwartkruis, Evita; Hogendoorn, Pancras C W; Kroon, Herman M; Briaire-de Bruijn, Inge; Bovée, Judith V M G

2015-10-01

Periosteal chondrosarcoma is a rare, malignant cartilage-forming neoplasm originating from the periosteal surface of bone. We collected 38 cases from the archives of the Netherlands Committee on Bone Tumours, with the aim of studying histological features and evaluating the involvement of isocitrate dehydrogenase 1 (IDH1), EXT, Wnt/β-catenin, the pRB pathway (CDK4 and p16), and the TP53 pathway (p53 and MDM2). Histology showed a moderately cellular matrix with mucoid-myxoid changes and, in 42% of cases, formation of a neocortex. Occasional intramedullary extension (26%) and subsequent host bone entrapment (40%) were seen. Histological grading revealed grade 1 (53%) and grade 2 (45%). The EXT1 protein was normally expressed, and mutations in IDH1 were observed in only 15% of cases. pRb signalling was deregulated by loss of p16 expression in 50% of cases, and Wnt signalling was lost in 89%. No alterations were found in CDK4, p53, or MDM2. We report the first large histological and molecular study on periosteal chondrosarcoma showing that histopathological examination and molecular aberrations do not predict prognosis. Although the mutation frequency of IDH1 was low, we confirm the supposed relationship with central chondrosarcoma. Moreover, we identify loss of canonical Wnt signalling and deregulation of pRb signalling as possible events contributing to its histogenesis. © 2015 John Wiley & Sons Ltd.

Critical protein GAPDH and its regulatory mechanisms in cancer cells

PubMed Central

Zhang, Jin-Ying; Zhang, Fan; Hong, Chao-Qun; Giuliano, Armando E.; Cui, Xiao-Jiang; Zhou, Guang-Ji; Zhang, Guo-Jun; Cui, Yu-Kun

2015-01-01

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), initially identified as a glycolytic enzyme and considered as a housekeeping gene, is widely used as an internal control in experiments on proteins, mRNA, and DNA. However, emerging evidence indicates that GAPDH is implicated in diverse functions independent of its role in energy metabolism; the expression status of GAPDH is also deregulated in various cancer cells. One of the most common effects of GAPDH is its inconsistent role in the determination of cancer cell fate. Furthermore, studies have described GAPDH as a regulator of cell death; other studies have suggested that GAPDH participates in tumor progression and serves as a new therapeutic target. However, related regulatory mechanisms of its numerous cellular functions and deregulated expression levels remain unclear. GAPDH is tightly regulated at transcriptional and posttranscriptional levels, which are involved in the regulation of diverse GAPDH functions. Several cancer-related factors, such as insulin, hypoxia inducible factor-1 (HIF-1), p53, nitric oxide (NO), and acetylated histone, not only modulate GAPDH gene expression but also affect protein functions via common pathways. Moreover, posttranslational modifications (PTMs) occurring in GAPDH in cancer cells result in new activities unrelated to the original glycolytic function of GAPDH. In this review, recent findings related to GAPDH transcriptional regulation and PTMs are summarized. Mechanisms and pathways involved in GAPDH regulation and its different roles in cancer cells are also described. PMID:25859407

Deregulation of E2-EPF ubiquitin carrier protein in papillary renal cell carcinoma.

PubMed

Roos, Frederik C; Evans, Andrew J; Brenner, Walburgis; Wondergem, Bill; Klomp, Jeffery; Heir, Pardeep; Roche, Olga; Thomas, Christian; Schimmel, Heiko; Furge, Kyle A; Teh, Bin T; Thüroff, Joachim W; Hampel, Christian; Ohh, Michael

2011-02-01

Molecular pathways associated with pathogenesis of sporadic papillary renal cell carcinoma (PRCC), the second most common form of kidney cancer, are poorly understood. We analyzed primary tumor specimens from 35 PRCC patients treated by nephrectomy via gene expression analysis and tissue microarrays constructed from an additional 57 paraffin-embedded PRCC samples via immunohistochemistry. Gene products were validated and further studied by Western blot analyses using primary PRCC tumor samples and established renal cell carcinoma cell lines, and potential associations with pathologic variables and survival in 27 patients with follow-up information were determined. We show that the expression of E2-EPF ubiquitin carrier protein, which targets the principal negative regulator of hypoxia-inducible factor (HIF), von Hippel-Lindau protein, for proteasome-dependent degradation, is markedly elevated in the majority of PRCC tumors exhibiting increased HIF1α expression, and is associated with poor prognosis. In addition, we identified multiple hypoxia-responsive elements within the E2-EPF promoter, and for the first time we demonstrated that E2-EPF is a hypoxia-inducible gene directly regulated via HIF1. These findings reveal deregulation of the oxygen-sensing pathway impinging on the positive feedback mechanism of HIF1-mediated regulation of E2-EPF in PRCC. Copyright © 2011 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

A new role under sortilin's belt in cancer

PubMed Central

Wilson, Cornelia M.; Naves, Thomas; Akhrass, Hussein Al; Vincent, François; Melloni, Boris; Bonnaud, François; Lalloué, Fabrice; Jauberteau, Marie-Odile

2016-01-01

ABSTRACT The neurotensin receptor-3 also known as sortilin was the first member of the small family of vacuolar protein sorting 10 protein domain (Vps10p) discovered two decades ago in the human brain. The expression of sortilin is not confined to the nervous system but sortilin is ubiquitously expressed in many tissues. Sortilin has multiple roles in the cell as a receptor or a co-receptor, in protein transport of many interacting partners to the plasma membrane, to the endocytic pathway and to the lysosomes for protein degradation. Sortilin could be considered as the cells own shuttle system. In many human diseases including neurological diseases and cancer, sortilin expression has been shown to be deregulated. In addition, some studies have highlighted that the extracellular domain of sortilin is shedded into the culture media by an unknown mechanism. Sortilin can be released in exosomes and appears to control some mechanisms of exosome biogenesis. In lung cancer cells, sortilin can associate with two receptor tyrosine kinase receptors called the TES complex found in exosomes. Exosomes carrying the TES complex can convey a microenvironment control through the activation of ErbB signaling pathways and the release of angiogenic factors. Deregulation of sortilin function is now emerging to be implicated in four major human diseases- cardiovascular disease, Type 2 diabetes mellitus, Alzheimer disease and cancer. PMID:27066187

Gene signature critical to cancer phenotype as a paradigm for anti-cancer drug discovery

PubMed Central

Sampson, Erik R.; McMurray, Helene R.; Hassane, Duane C.; Newman, Laurel; Salzman, Peter; Jordan, Craig T.; Land, Hartmut

2013-01-01

Malignant cell transformation commonly results in the deregulation of thousands of cellular genes, an observation that suggests a complex biological process and an inherently challenging scenario for the development of effective cancer interventions. To better define the genes/pathways essential to regulating the malignant phenotype, we recently described a novel strategy based on the cooperative nature of carcinogenesis that focuses on genes synergistically deregulated in response to cooperating oncogenic mutations. These so-called “cooperation response genes” (CRGs) are highly enriched for genes critical for the cancer phenotype, thereby suggesting their causal role in the malignant state. Here we show that CRGs play an essential role in drug-mediated anti-cancer activity and that anti-cancer agents can be identified through their ability to antagonize the CRG expression profile. These findings provide proof-of-concept for the use of the CRG signature as a novel means of drug discovery with relevance to underlying anti-cancer drug mechanisms. PMID:22964631

Itch/β-arrestin2-dependent non-proteolytic ubiquitylation of SuFu controls Hedgehog signalling and medulloblastoma tumorigenesis.

PubMed

Infante, Paola; Faedda, Roberta; Bernardi, Flavia; Bufalieri, Francesca; Lospinoso Severini, Ludovica; Alfonsi, Romina; Mazzà, Daniela; Siler, Mariangela; Coni, Sonia; Po, Agnese; Petroni, Marialaura; Ferretti, Elisabetta; Mori, Mattia; De Smaele, Enrico; Canettieri, Gianluca; Capalbo, Carlo; Maroder, Marella; Screpanti, Isabella; Kool, Marcel; Pfister, Stefan M; Guardavaccaro, Daniele; Gulino, Alberto; Di Marcotullio, Lucia

2018-03-07

Suppressor of Fused (SuFu), a tumour suppressor mutated in medulloblastoma, is a central player of Hh signalling, a pathway crucial for development and deregulated in cancer. Although the control of Gli transcription factors by SuFu is critical in Hh signalling, our understanding of the mechanism regulating this key event remains limited. Here, we show that the Itch/β-arrestin2 complex binds SuFu and induces its Lys63-linked polyubiquitylation without affecting its stability. This process increases the association of SuFu with Gli3, promoting the conversion of Gli3 into a repressor, which keeps Hh signalling off. Activation of Hh signalling antagonises the Itch-dependent polyubiquitylation of SuFu. Notably, different SuFu mutations occurring in medulloblastoma patients are insensitive to Itch activity, thus leading to deregulated Hh signalling and enhancing medulloblastoma cell growth. Our findings uncover mechanisms controlling the tumour suppressive functions of SuFu and reveal that their alterations are implicated in medulloblastoma tumorigenesis.

Bioinformatics in protein kinases regulatory network and drug discovery.

PubMed

Chen, Qingfeng; Luo, Haiqiong; Zhang, Chengqi; Chen, Yi-Ping Phoebe

2015-04-01

Protein kinases have been implicated in a number of diseases, where kinases participate many aspects that control cell growth, movement and death. The deregulated kinase activities and the knowledge of these disorders are of great clinical interest of drug discovery. The most critical issue is the development of safe and efficient disease diagnosis and treatment for less cost and in less time. It is critical to develop innovative approaches that aim at the root cause of a disease, not just its symptoms. Bioinformatics including genetic, genomic, mathematics and computational technologies, has become the most promising option for effective drug discovery, and has showed its potential in early stage of drug-target identification and target validation. It is essential that these aspects are understood and integrated into new methods used in drug discovery for diseases arisen from deregulated kinase activity. This article reviews bioinformatics techniques for protein kinase data management and analysis, kinase pathways and drug targets and describes their potential application in pharma ceutical industry. Copyright © 2015 Elsevier Inc. All rights reserved.

Cdk5: one of the links between senile plaques and neurofibrillary tangles?

PubMed

Lee, Ming-Sum; Tsai, Li-Huei

2003-04-01

The relationship between amyloid plaques and neurofibrillary tangles, the two pathologic hallmarks of Alzheimer's disease (AD), is an unknown and controversial subject. However, emerging evidence from genetic and biochemical studies suggests that accumulation of amyloid beta peptides may play a causative role in AD pathogenesis. This led to the amyloid hypothesis, which proposes that amyloid beta peptides disrupt neuronal metabolic and ionic homeostasis and cause aberrant activation of kinases and/or inhibition of phosphatases. The resulting alteration in kinase and phosphatase activities ultimately leads to hyperphosphorylation of tau and formation of neurofibrillary tangles. Cyclin-dependent kinase 5 (Cdk5) is a tau kinase whose activity is induced by amyloid beta peptides. Its deregulation may represent one of the signal transduction pathways that connect amyloid beta toxicity to tau hyperphosphorylation. This article reviews the functions and regulation of Cdk5. Evidence that suggests deregulation of Cdk5 activity in AD by virtue of calpain cleavage of its activator p35 to p25 will be discussed.

Complement-Mediated Regulation of Metabolism and Basic Cellular Processes.

PubMed

Hess, Christoph; Kemper, Claudia

2016-08-16

Complement is well appreciated as a critical arm of innate immunity. It is required for the removal of invading pathogens and works by directly destroying them through the activation of innate and adaptive immune cells. However, complement activation and function is not confined to the extracellular space but also occurs within cells. Recent work indicates that complement activation regulates key metabolic pathways and thus can impact fundamental cellular processes, such as survival, proliferation, and autophagy. Newly identified functions of complement include a key role in shaping metabolic reprogramming, which underlies T cell effector differentiation, and a role as a nexus for interactions with other effector systems, in particular the inflammasome and Notch transcription-factor networks. This review focuses on the contributions of complement to basic processes of the cell, in particular the integration of complement with cellular metabolism and the potential implications in infection and other disease settings. Copyright © 2016 Elsevier Inc. All rights reserved.

Regulation of the Wnt/β-Catenin Signaling Pathway by Human Papillomavirus E6 and E7 Oncoproteins

PubMed Central

Muñoz Bello, Jesus Omar; Olmedo Nieva, Leslie; Contreras Paredes, Adriana; Fuentes Gonzalez, Alma Mariana; Rocha Zavaleta, Leticia; Lizano, Marcela

2015-01-01

Cell signaling pathways are the mechanisms by which cells transduce external stimuli, which control the transcription of genes, to regulate diverse biological effects. In cancer, distinct signaling pathways, such as the Wnt/β-catenin pathway, have been implicated in the deregulation of critical molecular processes that affect cell proliferation and differentiation. For example, changes in β-catenin localization have been identified in Human Papillomavirus (HPV)-related cancers as the lesion progresses. Specifically, β-catenin relocates from the membrane/cytoplasm to the nucleus, suggesting that this transcription regulator participates in cervical carcinogenesis. The E6 and E7 oncoproteins are responsible for the transforming activity of HPV, and some studies have implicated these viral oncoproteins in the regulation of the Wnt/β-catenin pathway. Nevertheless, new interactions of HPV oncoproteins with cellular proteins are emerging, and the study of the biological effects of such interactions will help to understand HPV-related carcinogenesis. This review addresses the accumulated evidence of the involvement of the HPV E6 and E7 oncoproteins in the activation of the Wnt/β-catenin pathway. PMID:26295406

C1q-Mediated Complement Activation and C3 Opsonization Trigger Recognition of Stealth Poly(2-methyl-2-oxazoline)-Coated Silica Nanoparticles by Human Phagocytes.

PubMed

Tavano, Regina; Gabrielli, Luca; Lubian, Elisa; Fedeli, Chiara; Visentin, Silvia; Polverino De Laureto, Patrizia; Arrigoni, Giorgio; Geffner-Smith, Alessandra; Chen, Fangfang; Simberg, Dmitri; Morgese, Giulia; Benetti, Edmondo M; Wu, Linping; Moghimi, Seyed Moein; Mancin, Fabrizio; Papini, Emanuele

2018-05-23

Poly(2-methyl-2-oxazoline) (PMOXA) is an alternative promising polymer to poly(ethylene glycol) (PEG) for design and engineering of macrophage-evading nanoparticles (NPs). Although PMOXA-engineered NPs have shown comparable pharmacokinetics and in vivo performance to PEGylated stealth NPs in the murine model, its interaction with elements of the human innate immune system has not been studied. From a translational angle, we studied the interaction of fully characterized PMOXA-coated vinyltriethoxysilane-derived organically modified silica NPs (PMOXA-coated NPs) of approximately 100 nm in diameter with human complement system, blood leukocytes, and macrophages and compared their performance with PEGylated and uncoated NP counterparts. Through detailed immunological and proteomic profiling, we show that PMOXA-coated NPs extensively trigger complement activation in human sera exclusively through the classical pathway. Complement activation is initiated by the sensing molecule C1q, where C1q binds with high affinity ( K d = 11 ± 1 nM) to NP surfaces independent of immunoglobulin binding. C1q-mediated complement activation accelerates PMOXA opsonization with the third complement protein (C3) through the amplification loop of the alternative pathway. This promoted NP recognition by human blood leukocytes and monocyte-derived macrophages. The macrophage capture of PMOXA-coated NPs correlates with sera donor variability in complement activation and opsonization but not with other major corona proteins, including clusterin and a wide range of apolipoproteins. In contrast to these observations, PMOXA-coated NPs poorly activated the murine complement system and were marginally recognized by mouse macrophages. These studies provide important insights into compatibility of engineered NPs with elements of the human innate immune system for translational steps.

Targeting the Hippo Signaling Pathway for Tissue Regeneration and Cancer Therapy

PubMed Central

Juan, Wen Chun; Hong, Wanjin

2016-01-01

The Hippo signaling pathway is a highly-conserved developmental pathway that plays an essential role in organ size control, tumor suppression, tissue regeneration and stem cell self-renewal. The YES-associated protein (YAP) and the transcriptional co-activator with PDZ-binding motif (TAZ) are two important transcriptional co-activators that are negatively regulated by the Hippo signaling pathway. By binding to transcription factors, especially the TEA domain transcription factors (TEADs), YAP and TAZ induce the expression of growth-promoting genes, which can promote organ regeneration after injury. Therefore, controlled activation of YAP and TAZ can be useful for regenerative medicine. However, aberrant activation of YAP and TAZ due to deregulation of the Hippo pathway or overexpression of YAP/TAZ and TEADs can promote cancer development. Hence, pharmacological inhibition of YAP and TAZ may be a useful approach to treat tumors with high YAP and/or TAZ activity. In this review, we present the mechanisms regulating the Hippo pathway, the role of the Hippo pathway in tissue repair and cancer, as well as a detailed analysis of the different strategies to target the Hippo signaling pathway and the genes regulated by YAP and TAZ for regenerative medicine and cancer therapy. PMID:27589805

Targeting the Hippo Signaling Pathway for Tissue Regeneration and Cancer Therapy.

PubMed

Juan, Wen Chun; Hong, Wanjin

2016-08-30

The Hippo signaling pathway is a highly-conserved developmental pathway that plays an essential role in organ size control, tumor suppression, tissue regeneration and stem cell self-renewal. The YES-associated protein (YAP) and the transcriptional co-activator with PDZ-binding motif (TAZ) are two important transcriptional co-activators that are negatively regulated by the Hippo signaling pathway. By binding to transcription factors, especially the TEA domain transcription factors (TEADs), YAP and TAZ induce the expression of growth-promoting genes, which can promote organ regeneration after injury. Therefore, controlled activation of YAP and TAZ can be useful for regenerative medicine. However, aberrant activation of YAP and TAZ due to deregulation of the Hippo pathway or overexpression of YAP/TAZ and TEADs can promote cancer development. Hence, pharmacological inhibition of YAP and TAZ may be a useful approach to treat tumors with high YAP and/or TAZ activity. In this review, we present the mechanisms regulating the Hippo pathway, the role of the Hippo pathway in tissue repair and cancer, as well as a detailed analysis of the different strategies to target the Hippo signaling pathway and the genes regulated by YAP and TAZ for regenerative medicine and cancer therapy.

The MST/Hippo Pathway and Cell Death: A Non-Canonical Affair

PubMed Central

Fallahi, Emma; O’Driscoll, Niamh A.; Matallanas, David

2016-01-01

The MST/Hippo signalling pathway was first described over a decade ago in Drosophila melanogaster and the core of the pathway is evolutionary conserved in mammals. The mammalian MST/Hippo pathway regulates organ size, cell proliferation and cell death. In addition, it has been shown to play a central role in the regulation of cellular homeostasis and it is commonly deregulated in human tumours. The delineation of the canonical pathway resembles the behaviour of the Hippo pathway in the fly where the activation of the core kinases of the pathway prevents the proliferative signal mediated by the key effector of the pathway YAP. Nevertheless, several lines of evidence support the idea that the mammalian MST/Hippo pathway has acquired new features during evolution, including different regulators and effectors, crosstalk with other essential signalling pathways involved in cellular homeostasis and the ability to actively trigger cell death. Here we describe the current knowledge of the mechanisms that mediate MST/Hippo dependent cell death, especially apoptosis. We include evidence for the existence of complex signalling networks where the core proteins of the pathway play a central role in controlling the balance between survival and cell death. Finally, we discuss the possible involvement of these signalling networks in several human diseases such as cancer, diabetes and neurodegenerative disorders. PMID:27322327

The Gly-54-->Asp allelic form of human mannose-binding protein (MBP) fails to bind MBP-associated serine protease.

PubMed Central

Matsushita, M; Ezekowitz, R A; Fujita, T

1995-01-01

The human mannose-binding protein (MBP) is a pattern recognition molecule that appears to play a role in initial host defence. MBP activates the complement cascade and it may act as an opsonin both in the absence and in the presence of complement. A number of distinct MBP allelic forms exist in different population groups. An allele that occurs in 5-7% of Caucasians was identified by an inability to activate the complement system. A homozygous mutation at base pair 230 of the MBP gene results in a Gly-to-Asp substitution at the fifth collagen repeat. It appears that the resultant protein, MBPD, is able to form high-order multimers that bind bacteria but do not support complement activation. Recently a novel serine protease, the MBP-associated serine protease (MASP), has been described. MBP-MASP complexes circulate in serum and result in the direct activation of a novel complement pathway (lectin pathway) in the absence of the first complement components. In this study we demonstrate that MASP and its proenzyme proMASP are unable to bind to recombinant (r)MBPD. This lack of a MASP-rMBPD association corresponds to a failure of the Gly-54-->Asp form of MBP to activate complement. Our results provide a biochemical basis for the functional deficit in the Gly-54-->Asp allelic form of MBP and suggest that the proMASP/MASP binding site maps to the fifth collagen repeat of MBP. Images Figure 1 PMID:7487919

Complement Inhibition Alleviates Paraquat-Induced Acute Lung Injury

PubMed Central

Sun, Shihui; Wang, Hanbin; Zhao, Guangyu; An, Yingbo; Guo, Yan; Du, Lanying; Song, Hongbin; Qiao, Fei; Yu, Hong; Wu, Xiaohong; Atkinson, Carl; Jiang, Shibo; Tomlinson, Stephen

2011-01-01

The widely used herbicide, paraquat (PQ), is highly toxic and claims thousands of lives from both accidental and voluntary ingestion. The pathological mechanisms of PQ poisoning–induced acute lung injury (ALI) are not well understood, and the role of complement in PQ-induced ALI has not been elucidated. We developed and characterized a mouse model of PQ-induced ALI and studied the role of complement in the pathogenesis of PQ poisoning. Intraperitoneal administration of PQ caused dose- and time-dependent lung damage and mortality, with associated inflammatory response. Within 24 hours of PQ-induced ALI, there was significantly increased expression of the complement proteins, C1q and C3, in the lung. Expression of the anaphylatoxin receptors, C3aR and C5aR, was also increased. Compared with wild-type mice, C3-deficient mice survived significantly longer and displayed significantly reduced lung inflammation and pathology after PQ treatment. Similar reductions in PQ-induced inflammation, pathology, and mortality were recorded in mice treated with the C3 inhibitors, CR2-Crry, and alternative pathway specific CR2-fH. A similar therapeutic effect was also observed by treatment with either C3a receptor antagonist or a blocking C5a receptor monoclonal antibody. Together, these studies indicate that PQ-induced ALI is mediated through receptor signaling by the C3a and C5a complement activation products that are generated via the alternative complement pathway, and that complement inhibition may be an effective clinical intervention for postexposure treatment of PQ-induced ALI. PMID:21421909

LMW-E/CDK2 Deregulates Acinar Morphogenesis, Induces Tumorigenesis, and Associates with the Activated b-Raf-ERK1/2-mTOR Pathway in Breast Cancer Patients

PubMed Central

Duong, MyLinh T.; Akli, Said; Wei, Caimiao; Wingate, Hannah F.; Liu, Wenbin; Lu, Yiling; Yi, Min; Mills, Gordon B.; Hunt, Kelly K.; Keyomarsi, Khandan

2012-01-01

Elastase-mediated cleavage of cyclin E generates low molecular weight cyclin E (LMW-E) isoforms exhibiting enhanced CDK2–associated kinase activity and resistance to inhibition by CDK inhibitors p21 and p27. Approximately 27% of breast cancers express high LMW-E protein levels, which significantly correlates with poor survival. The objective of this study was to identify the signaling pathway(s) deregulated by LMW-E expression in breast cancer patients and to identify pharmaceutical agents to effectively target this pathway. Ectopic LMW-E expression in nontumorigenic human mammary epithelial cells (hMECs) was sufficient to generate xenografts with greater tumorigenic potential than full-length cyclin E, and the tumorigenicity was augmented by in vivo passaging. However, cyclin E mutants unable to interact with CDK2 protected hMECs from tumor development. When hMECs were cultured on Matrigel, LMW-E mediated aberrant acinar morphogenesis, including enlargement of acinar structures and formation of multi-acinar complexes, as denoted by reduced BIM and elevated Ki67 expression. Similarly, inducible expression of LMW-E in transgenic mice generated hyper-proliferative terminal end buds resulting in enhanced mammary tumor development. Reverse-phase protein array assay of 276 breast tumor patient samples and cells cultured on monolayer and in three-dimensional Matrigel demonstrated that, in terms of protein expression profile, hMECs cultured in Matrigel more closely resembled patient tissues than did cells cultured on monolayer. Additionally, the b-Raf-ERK1/2-mTOR pathway was activated in LMW-E–expressing patient samples, and activation of this pathway was associated with poor disease-specific survival. Combination treatment using roscovitine (CDK inhibitor) plus either rapamycin (mTOR inhibitor) or sorafenib (a pan kinase inhibitor targeting b-Raf) effectively prevented aberrant acinar formation in LMW-E–expressing cells by inducing G1/S cell cycle arrest. LMW-E requires CDK2–associated kinase activity to induce mammary tumor formation by disrupting acinar development. The b-Raf-ERK1/2-mTOR signaling pathway is aberrantly activated in breast cancer and can be suppressed by combination treatment with roscovitine plus either rapamycin or sorafenib. PMID:22479189

Complement C5-inhibiting therapy for the thrombotic microangiopathies: accumulating evidence, but not a panacea

PubMed Central

Brocklebank, Vicky

2017-01-01

Abstract Thrombotic microangiopathy (TMA), characterized by organ injury occurring consequent to severe endothelial damage, can manifest in a diverse range of diseases. In complement-mediated atypical haemolytic uraemic syndrome (aHUS) a primary defect in complement, such as a mutation or autoantibody leading to over activation of the alternative pathway, predisposes to the development of disease, usually following exposure to an environmental trigger. The elucidation of the pathogenesis of aHUS resulted in the successful introduction of the complement inhibitor eculizumab into clinical practice. In other TMAs, although complement activation may be seen, its role in the pathogenesis remains to be confirmed by an interventional trial. Although many case reports in TMAs other than complement-mediated aHUS hint at efficacy, publication bias, concurrent therapies and in some cases the self-limiting nature of disease make broader interpretation difficult. In this article, we will review the evidence for the role of complement inhibition in complement-mediated aHUS and other TMAs. PMID:28980670

Innate Immune Mechanisms in Transplant Allograft Vasculopathy

PubMed Central

Jane-wit, D; Fang, C; Goldstein, DR

2016-01-01

Purpose of Review Allograft vasculopathy (AV) is the leading cause of late allograft loss following solid organ transplantation. Ischemia reperfusion injury (IRI) and donor specific antibody (DSA)-induced complement activation confer heightened risk for AV via numerous innate immune mechanisms including MyD88, HMGB1, and complement induced non-canonical NF-kB signaling. Recent Findings The role of MyD88, a signal adaptor downstream of the toll-like receptors (TLR), has been defined in an experimental heart transplant model, which demonstrated that recipient MyD88 enhanced AV. Importantly, triggering receptor on myeloid receptor 1(Trem1), a MyD88 amplifying signal, was present in rejecting human cardiac transplant biopsies and enhanced the development of AV in mice. HMGB1, a nuclear protein that activates TLRs, also enhanced the development of AV. Complement activation elicits assembly of membrane attack complexes (MAC) on endothelial cells which activate non-canonical NF-kB signaling, a novel complement effector pathway that induces pro-inflammatory genes and potentiates endothelial cell mediated alloimmune T cell activation, processes which enhance AV. Summary Innate immune mediators including HMGB1, MyD88, and non-canonical NFκB signaling via complement activation contribute to AV. These pathways represent potential therapeutic targets to reduce AV after solid organ transplantation. PMID:27077602

Differential microRNA expression in the prefrontal cortex of mouse offspring induced by glyphosate exposure during pregnancy and lactation.

PubMed

Ji, Hua; Xu, Linhao; Wang, Zheng; Fan, Xinli; Wu, Lihui

2018-03-01

Glyphosate is the active ingredient in numerous herbicide formulations. The role of glyphosate in neurotoxicity has been reported in human and animal models. However, the detailed mechanism of the role of glyphosate in neuronal development remains unknown. Recently, several studies have reported evidence linking neurodevelopmental disorders (NDDs) with gestational glyphosate exposure. The current group previously identified microRNAs (miRNAs) that are associated with the etiology of NDDs, but their expression levels in the developing brain following glyphosate exposure have not been characterized. In the present study, miRNA expression patterns were evaluated in the prefrontal cortex (PFC) of 28 postnatal day mouse offspring following glyphosate exposure during pregnancy and lactation. An miRNA microarray detected 55 upregulated and 19 downregulated miRNAs in the PFC of mouse offspring, and 20 selected deregulated miRNAs were further evaluated by quantitative polymerase chain reaction (PCR). A total of 11 targets of these selected deregulated miRNAs were analyzed using bioinformatics. Gene Ontology (GO) terms associated with the relevant miRNAs included neurogenesis (GO:0050769), neuron differentiation (GO:0030182) and brain development (GO:0007420). The genes Cdkn1a, Numbl, Notch1, Fosl1 and Lef1 are involved in the Wnt and Notch signaling pathways, which are closely associated with neural development. PCR arrays for the mouse Wnt and Notch signaling pathways were used to validate the effects of glyphosate on the expression pattern of genes involved in the Wnt and Notch pathways. Nr4a2 and Wnt7b were downregulated, while Dkk1, Dixdc1, Runx1, Shh, Lef-1 and Axin2 were upregulated in the PFC of mice offspring following glyphosate exposure during pregnancy and lactation. These results indicated abnormalities of the Wnt/β-catenin and Notch pathways. These findings may be of particular interest for understanding the mechanism of glyphosate-induced neurotoxicity, as well as helping to clarify the association between glyphosate and NDDs.

Differential microRNA expression in the prefrontal cortex of mouse offspring induced by glyphosate exposure during pregnancy and lactation

PubMed Central

Ji, Hua; Xu, Linhao; Wang, Zheng; Fan, Xinli; Wu, Lihui

2018-01-01

Glyphosate is the active ingredient in numerous herbicide formulations. The role of glyphosate in neurotoxicity has been reported in human and animal models. However, the detailed mechanism of the role of glyphosate in neuronal development remains unknown. Recently, several studies have reported evidence linking neurodevelopmental disorders (NDDs) with gestational glyphosate exposure. The current group previously identified microRNAs (miRNAs) that are associated with the etiology of NDDs, but their expression levels in the developing brain following glyphosate exposure have not been characterized. In the present study, miRNA expression patterns were evaluated in the prefrontal cortex (PFC) of 28 postnatal day mouse offspring following glyphosate exposure during pregnancy and lactation. An miRNA microarray detected 55 upregulated and 19 downregulated miRNAs in the PFC of mouse offspring, and 20 selected deregulated miRNAs were further evaluated by quantitative polymerase chain reaction (PCR). A total of 11 targets of these selected deregulated miRNAs were analyzed using bioinformatics. Gene Ontology (GO) terms associated with the relevant miRNAs included neurogenesis (GO:0050769), neuron differentiation (GO:0030182) and brain development (GO:0007420). The genes Cdkn1a, Numbl, Notch1, Fosl1 and Lef1 are involved in the Wnt and Notch signaling pathways, which are closely associated with neural development. PCR arrays for the mouse Wnt and Notch signaling pathways were used to validate the effects of glyphosate on the expression pattern of genes involved in the Wnt and Notch pathways. Nr4a2 and Wnt7b were downregulated, while Dkk1, Dixdc1, Runx1, Shh, Lef-1 and Axin2 were upregulated in the PFC of mice offspring following glyphosate exposure during pregnancy and lactation. These results indicated abnormalities of the Wnt/β-catenin and Notch pathways. These findings may be of particular interest for understanding the mechanism of glyphosate-induced neurotoxicity, as well as helping to clarify the association between glyphosate and NDDs. PMID:29467848

PI3K and Bcl-2 inhibition primes glioblastoma cells to apoptosis through downregulation of Mcl-1 and Phospho-BAD.

PubMed

Pareja, Fresia; Macleod, David; Shu, Chang; Crary, John F; Canoll, Peter D; Ross, Alonzo H; Siegelin, Markus D

2014-07-01

Glioblastoma multiforme (GBM) is a highly malignant human brain neoplasm with limited therapeutic options. GBMs display a deregulated apoptotic pathway with high levels of the antiapoptotic Bcl-2 family of proteins and overt activity of the phosphatidylinositol 3-kinase (PI3K) signaling pathway. Therefore, combined interference of the PI3K pathway and the Bcl-2 family of proteins is a reasonable therapeutic strategy. ABT-263 (Navitoclax), an orally available small-molecule Bcl-2 inhibitor, and GDC-0941, a PI3K inhibitor, were used to treat established glioblastoma and glioblastoma neurosphere cells, alone or in combination. Although GDC-0941 alone had a modest effect on cell viability, treatment with ABT-263 displayed a marked reduction of cell viability and induction of apoptotic cell death. Moreover, combinatorial therapy using ABT-263 and GDC-0941 showed an enhanced effect, with a further decrease in cellular viability. Furthermore, combination treatment abrogated the ability of stem cell-like glioma cells to form neurospheres. ABT-263 and GDC-0941, in combination, resulted in a consistent and significant increase of Annexin V positive cells and loss of mitochondrial membrane potential compared with either monotherapy. The combination treatment led to enhanced cleavage of both initiator and effector caspases. Mechanistically, GDC-0941 depleted pAKT (Serine 473) levels and suppressed Mcl-1 protein levels, lowering the threshold for the cytotoxic actions of ABT-263. GDC-0941 decreased Mcl-1 in a posttranslational manner and significantly decreased the half-life of Mcl-1 protein. Ectopic expression of human Mcl-1 mitigated apoptotic cell death induced by the drug combination. Furthermore, GDC-0941 modulated the phosphorylation status of BAD, thereby further enhancing ABT-263-mediated cell death. Combination therapy with ABT-263 and GDC-0941 has novel therapeutic potential by specifically targeting aberrantly active, deregulated pathways in GBM, overcoming endogenous resistance to apoptosis. ©2014 American Association for Cancer Research.

The biological kinship of hypoxia with CSC and EMT and their relationship with deregulated expression of miRNAs and tumor aggressiveness

PubMed Central

Bao, Bin; Azmi, Asfar S.; Ali, Shadan; Ahmad, Aamir; Li, Yiwei; Banerjee, Sanjeev; Kong, Dejuan; Sarkar, Fazlul H.

2013-01-01

Hypoxia is one of the fundamental biological phenomena that are intricately associated with the development and aggressiveness of a variety of solid tumors. Hypoxia-inducible factors (HIF) function as a master transcription factor, which regulates hypoxia responsive genes and has been recognized to play critical roles in tumor invasion, metastasis, and chemo-radiation resistance, and contributes to increased cell proliferation, survival, angiogenesis and metastasis. Therefore, tumor hypoxia with deregulated expression of HIF and its biological consequence lead to poor prognosis of patients diagnosed with solid tumors, resulting in higher mortality, suggesting that understanding of the molecular relationship of hypoxia with other cellular features of tumor aggressiveness would be invaluable for developing newer targeted therapy for solid tumors. It has been well recognized that cancer stem cells (CSCs) and epithelial-to-mesenchymal transition (EMT) phenotypic cells are associated with therapeutic resistance and contribute to aggressive tumor growth, invasion, metastasis and believed to be the cause of tumor recurrence. Interestingly, hypoxia and HIF signaling pathway are known to play an important role in the regulation and sustenance of CSCs and EMT phenotype. However, the molecular relationship between HIF signaling pathway with the biology of CSCs and EMT remains unclear although NF-κB, PI3K/Akt/mTOR, Notch, Wnt/β-catenin, and Hedgehog signaling pathways have been recognized as important regulators of CSCs and EMT. In this article, we will discuss the state of our knowledge on the role of HIF-hypoxia signaling pathway and its kinship with CSCs and EMT within the tumor microenvironment. We will also discuss the potential role of hypoxia-induced microRNAs (miRNAs) in tumor development and aggressiveness, and finally discuss the potential effects of nutraceuticals on the biology of CSCs and EMT in the context of tumor hypoxia. PMID:22579961

TIC10/ONC201 synergizes with Bcl-2/Bcl-xL inhibition in glioblastoma by suppression of Mcl-1 and its binding partners in vitro and in vivo

PubMed Central

Karpel-Massler, Georg; Bâ, Maïmouna; Shu, Chang; Halatsch, Marc-Eric; Westhoff, Mike-Andrew; Bruce, Jeffrey N.; Canoll, Peter; Siegelin, Markus D.

2015-01-01

Glioblastoma is the most frequent primary brain tumor in adults. Current therapeutic options are sparse and the prognosis of patients suffering from this disease is grim. Abundance in intratumoral heterogeneity among different deregulated signaling pathways is a hallmark of glioblastoma and likely accounts for its recurrence and resistance to treatment. Glioblastomas harbor a plethora of deregulated pathways driving tumor formation and growth. In this study, we show that TIC10/ONC201, a promising compound that is currently in planned clinical development, along with Bcl-2/Bcl-xL inhibition by ABT263 yields a strong synergistic antiproliferative effect on pediatric, adult, proneural glioblastoma and glioma stem-like cells. On the molecular level, treatment with TIC10/ONC201 results in a posttranslational decrease of the anti-apoptotic Bcl-2 family member, myeloid cell leukemia 1 (Mcl-1), through modulation of the chaperone Bag3 and the deubiquitinase Usp9X. Consistently, the combination treatment of TIC10/ONC201 and ABT263 required the presence of functional BAX and BAK to drive intrinsic apoptosis, but is surprisingly independent of the extrinsic apoptotic pathway. Moreover, the expression of Noxa protein was required for efficient apoptosis induction by TIC10/ONC201 and ABT263. Importantly, the drug combination of TIC10/ONC201 and the BH3-mimetic, ABT263, led to a regression of tumors in vivo, without any notable toxicity and side effects. Overall, TIC10/ONC201 along with Bcl-2/Bcl-xL inhibition holds significant promise as a novel potential approach for the treatment of recalcitrant tumors such as glioblastoma. PMID:26474387

TIC10/ONC201 synergizes with Bcl-2/Bcl-xL inhibition in glioblastoma by suppression of Mcl-1 and its binding partners in vitro and in vivo.

PubMed

Karpel-Massler, Georg; Bâ, Maïmouna; Shu, Chang; Halatsch, Marc-Eric; Westhoff, Mike-Andrew; Bruce, Jeffrey N; Canoll, Peter; Siegelin, Markus D

2015-11-03

Glioblastoma is the most frequent primary brain tumor in adults. Current therapeutic options are sparse and the prognosis of patients suffering from this disease is grim. Abundance in intratumoral heterogeneity among different deregulated signaling pathways is a hallmark of glioblastoma and likely accounts for its recurrence and resistance to treatment. Glioblastomas harbor a plethora of deregulated pathways driving tumor formation and growth. In this study, we show that TIC10/ONC201, a promising compound that is currently in planned clinical development, along with Bcl-2/Bcl-xL inhibition by ABT263 yields a strong synergistic antiproliferative effect on pediatric, adult, proneural glioblastoma and glioma stem-like cells. On the molecular level, treatment with TIC10/ONC201 results in a posttranslational decrease of the anti-apoptotic Bcl-2 family member, myeloid cell leukemia 1 (Mcl-1), through modulation of the chaperone Bag3 and the deubiquitinase Usp9X. Consistently, the combination treatment of TIC10/ONC201 and ABT263 required the presence of functional BAX and BAK to drive intrinsic apoptosis, but is surprisingly independent of the extrinsic apoptotic pathway. Moreover, the expression of Noxa protein was required for efficient apoptosis induction by TIC10/ONC201 and ABT263. Importantly, the drug combination of TIC10/ONC201 and the BH3-mimetic, ABT263, led to a regression of tumors in vivo, without any notable toxicity and side effects. Overall, TIC10/ONC201 along with Bcl-2/Bcl-xL inhibition holds significant promise as a novel potential approach for the treatment of recalcitrant tumors such as glioblastoma.

In silico pathway analysis in cervical carcinoma reveals potential new targets for treatment

PubMed Central

van Dam, Peter A.; van Dam, Pieter-Jan H. H.; Rolfo, Christian; Giallombardo, Marco; van Berckelaer, Christophe; Trinh, Xuan Bich; Altintas, Sevilay; Huizing, Manon; Papadimitriou, Kostas; Tjalma, Wiebren A. A.; van Laere, Steven

2016-01-01

An in silico pathway analysis was performed in order to improve current knowledge on the molecular drivers of cervical cancer and detect potential targets for treatment. Three publicly available Affymetrix gene expression data-sets (GSE5787, GSE7803, GSE9750) were retrieved, vouching for a total of 9 cervical cancer cell lines (CCCLs), 39 normal cervical samples, 7 CIN3 samples and 111 cervical cancer samples (CCSs). Predication analysis of microarrays was performed in the Affymetrix sets to identify cervical cancer biomarkers. To select cancer cell-specific genes the CCSs were compared to the CCCLs. Validated genes were submitted to a gene set enrichment analysis (GSEA) and Expression2Kinases (E2K). In the CCSs a total of 1,547 probe sets were identified that were overexpressed (FDR < 0.1). Comparing to CCCLs 560 probe sets (481 unique genes) had a cancer cell-specific expression profile, and 315 of these genes (65%) were validated. GSEA identified 5 cancer hallmarks enriched in CCSs (P < 0.01 and FDR < 0.25) showing that deregulation of the cell cycle is a major component of cervical cancer biology. E2K identified a protein-protein interaction (PPI) network of 162 nodes (including 20 drugable kinases) and 1626 edges. This PPI-network consists of 5 signaling modules associated with MYC signaling (Module 1), cell cycle deregulation (Module 2), TGFβ-signaling (Module 3), MAPK signaling (Module 4) and chromatin modeling (Module 5). Potential targets for treatment which could be identified were CDK1, CDK2, ABL1, ATM, AKT1, MAPK1, MAPK3 among others. The present study identified important driver pathways in cervical carcinogenesis which should be assessed for their potential therapeutic drugability. PMID:26701206

Structural basis for activation of the complement system by component C4 cleavage

PubMed Central

Kidmose, Rune T.; Laursen, Nick S.; Dobó, József; Kjaer, Troels R.; Sirotkina, Sofia; Yatime, Laure; Sottrup-Jensen, Lars; Thiel, Steffen; Gál, Péter; Andersen, Gregers R.

2012-01-01

An essential aspect of innate immunity is recognition of molecular patterns on the surface of pathogens or altered self through the lectin and classical pathways, two of the three well-established activation pathways of the complement system. This recognition causes activation of the MASP-2 or the C1s serine proteases followed by cleavage of the protein C4. Here we present the crystal structures of the 203-kDa human C4 and the 245-kDa C4⋅MASP-2 substrate⋅enzyme complex. When C4 binds to MASP-2, substantial conformational changes in C4 are induced, and its scissile bond region becomes ordered and inserted into the protease catalytic site in a manner canonical to serine proteases. In MASP-2, an exosite located within the CCP domains recognizes the C4 C345C domain 60 Å from the scissile bond. Mutations in C4 and MASP-2 residues at the C345C–CCP interface inhibit the intermolecular interaction and C4 cleavage. The possible assembly of the huge in vivo enzyme–substrate complex consisting of glycan-bound mannan-binding lectin, MASP-2, and C4 is discussed. Our own and prior functional data suggest that C1s in the classical pathway of complement activated by, e.g., antigen–antibody complexes, also recognizes the C4 C345C domain through a CCP exosite. Our results provide a unified structural framework for understanding the early and essential step of C4 cleavage in the elimination of pathogens and altered self through two major pathways of complement activation. PMID:22949645

Dengue virus induces increased activity of the complement alternative pathway in infected cells.

PubMed

Cabezas, Sheila; Bracho, Gustavo; L Aloia, Amanda; Adamson, Penelope J; Bonder, Claudine S; Smith, Justine R; Gordon, David L; Carr, Jillian M

2018-05-09

Severe dengue virus (DENV) infection is associated with overactivity of the complement alternative pathway (AP) in patient studies. Here, the molecular changes in components of the AP during DENV infection in vitro are investigated. mRNA for factor H (FH) a major negative regulator of the AP, is significantly increased in DENV-infected endothelial cells (EC) and macrophages but in contrast production of extracellular FH protein is not. This discord is not seen for the AP activator, factor B (FB), with DENV induction of both FB mRNA and protein, nor with Toll-like receptor 3 or 4 stimulation of EC and macrophages, which induces both FH and FB mRNA and protein. Surface bound and intracellular FH protein is however induced by DENV, but only in DENV antigen-positive cells, while in two other DENV-susceptible immortalised cell lines (ARPE-19 and HREC) FH protein is induced both intracellularly and extracellularly by DENV infection. Regardless of the cell type, there is an imbalance in AP components and an increase in markers of complement AP activity associated with DENV-infected cells - with lower FH relative to FB protein, increased ability to promote AP-mediated lytic activity and increased deposition of complement component C3b on the surface of DENV-infected cells. For EC in particular, these changes are predicted to result in higher complement activity in the local cellular microenvironment, with the potential to induce functional changes that may result in increased vascular permeability, a hallmark of dengue disease. IMPORTANCE Dengue virus (DENV) is a significant human viral pathogen with global medical and economic impact. DENV may cause serious and life-threatening disease with increased vascular permeability and plasma leakage. The pathogenic mechanisms underlying these features remain unclear; however overactivity of the complement alternative pathway has been suggested to play a role. In this study we investigate the molecular events that may be responsible for this observed alternative pathway overactivity and provide novel findings of changes in the complement system in response to DENV infection in primary cell types that are a major target for DENV infection (macrophages) and pathogenesis (endothelial cells) in vivo Our results suggest a new dimension of cellular events that may influence endothelial cell barrier function during DENV infection that could expand strategies for developing therapeutics to prevent or control DENV-mediated vascular disease. Copyright © 2018 American Society for Microbiology.

Micrurus snake venoms activate human complement system and generate anaphylatoxins

PubMed Central

2012-01-01

Background The genus Micrurus, coral snakes (Serpentes, Elapidae), comprises more than 120 species and subspecies distributed from the south United States to the south of South America. Micrurus snake bites can cause death by muscle paralysis and further respiratory arrest within a few hours after envenomation. Clinical observations show mainly neurotoxic symptoms, although other biological activities have also been experimentally observed, including cardiotoxicity, hemolysis, edema and myotoxicity. Results In the present study we have investigated the action of venoms from seven species of snakes from the genus Micrurus on the complement system in in vitro studies. Several of the Micrurus species could consume the classical and/or the lectin pathways, but not the alternative pathway, and C3a, C4a and C5a were generated in sera treated with the venoms as result of this complement activation. Micrurus venoms were also able to directly cleave the α chain of the component C3, but not of the C4, which was inhibited by 1,10 Phenanthroline, suggesting the presence of a C3α chain specific metalloprotease in Micrurus spp venoms. Furthermore, complement activation was in part associated with the cleavage of C1-Inhibitor by protease(s) present in the venoms, which disrupts complement activation control. Conclusion Micrurus venoms can activate the complement system, generating a significant amount of anaphylatoxins, which may assist due to their vasodilatory effects, to enhance the spreading of other venom components during the envenomation process. PMID:22248157

Micrurus snake venoms activate human complement system and generate anaphylatoxins.

PubMed

Tanaka, Gabriela D; Pidde-Queiroz, Giselle; de Fátima D Furtado, Maria; van den Berg, Carmen; Tambourgi, Denise V

2012-01-16

The genus Micrurus, coral snakes (Serpentes, Elapidae), comprises more than 120 species and subspecies distributed from the south United States to the south of South America. Micrurus snake bites can cause death by muscle paralysis and further respiratory arrest within a few hours after envenomation. Clinical observations show mainly neurotoxic symptoms, although other biological activities have also been experimentally observed, including cardiotoxicity, hemolysis, edema and myotoxicity. In the present study we have investigated the action of venoms from seven species of snakes from the genus Micrurus on the complement system in in vitro studies. Several of the Micrurus species could consume the classical and/or the lectin pathways, but not the alternative pathway, and C3a, C4a and C5a were generated in sera treated with the venoms as result of this complement activation. Micrurus venoms were also able to directly cleave the α chain of the component C3, but not of the C4, which was inhibited by 1,10 Phenanthroline, suggesting the presence of a C3α chain specific metalloprotease in Micrurus spp venoms. Furthermore, complement activation was in part associated with the cleavage of C1-Inhibitor by protease(s) present in the venoms, which disrupts complement activation control. Micrurus venoms can activate the complement system, generating a significant amount of anaphylatoxins, which may assist due to their vasodilatory effects, to enhance the spreading of other venom components during the envenomation process.

Functional Characterization of LcpA, a Surface-Exposed Protein of Leptospira spp. That Binds the Human Complement Regulator C4BP▿

PubMed Central

Barbosa, Angela S.; Monaris, Denize; Silva, Ludmila B.; Morais, Zenaide M.; Vasconcellos, Sílvio A.; Cianciarullo, Aurora M.; Isaac, Lourdes; Abreu, Patricia A. E.

2010-01-01

We have previously shown that pathogenic leptospiral strains are able to bind C4b binding protein (C4BP). Surface-bound C4BP retains its cofactor activity, indicating that acquisition of this complement regulator may contribute to leptospiral serum resistance. In the present study, the abilities of seven recombinant putative leptospiral outer membrane proteins to interact with C4BP were evaluated. The protein encoded by LIC11947 interacted with this human complement regulator in a dose-dependent manner. The cofactor activity of C4BP bound to immobilized recombinant LIC11947 (rLIC11947) was confirmed by detecting factor I-mediated cleavage of C4b. rLIC11947 was therefore named LcpA (for leptospiral complement regulator-acquiring protein A). LcpA was shown to be an outer membrane protein by using immunoelectron microscopy, cell surface proteolysis, and Triton X-114 fractionation. The gene coding for LcpA is conserved among pathogenic leptospiral strains. This is the first characterization of a Leptospira surface protein that binds to the human complement regulator C4BP in a manner that allows this important regulator to control complement system activation mediated either by the classical pathway or by the lectin pathway. This newly identified protein may play a role in immune evasion by Leptospira spp. and may therefore represent a target for the development of a human vaccine against leptospirosis. PMID:20404075

Mannose-binding lectin binds to Ebola and Marburg envelope glycoproteins, resulting in blocking of virus interaction with DC-SIGN and complement-mediated virus neutralization.

PubMed

Ji, Xin; Olinger, Gene G; Aris, Sheena; Chen, Ying; Gewurz, Henry; Spear, Gregory T

2005-09-01

Mannose-binding lectin (MBL), a serum lectin that mediates innate immune functions including activation of the lectin complement pathway, binds to carbohydrates expressed on some viral glycoproteins. In this study, the ability of MBL to bind to virus particles pseudotyped with Ebola and Marburg envelope glycoproteins was evaluated. Virus particles bearing either Ebola (Zaire strain) or Marburg (Musoke strain) envelope glycoproteins bound at significantly higher levels to immobilized MBL compared with virus particles pseudotyped with vesicular stomatitis virus glycoprotein or with no virus glycoprotein. As observed in previous studies, Ebola-pseudotyped virus bound to cells expressing the lectin DC-SIGN (dendritic cell-specific intercellular adhesion molecule 3-grabbing non-integrin). However, pre-incubation of virus with MBL blocked DC-SIGN-mediated binding to cells, suggesting that the two lectins bind at the same or overlapping sites on the Ebola glycoprotein. Neutralization experiments showed that virus pseudotyped with Ebola or Marburg (Musoke) glycoprotein was neutralized by complement, while the Marburg (Ravn strain) glycoprotein-pseudotyped virus was less sensitive to neutralization. Neutralization was partially mediated through the lectin complement pathway, since a complement source deficient in MBL was significantly less effective at neutralizing viruses pseudotyped with filovirus glycoproteins and addition of purified MBL to the MBL-deficient complement increased neutralization. These experiments demonstrated that MBL binds to filovirus envelope glycoproteins resulting in important biological effects and suggest that MBL can interact with filoviruses during infection in humans.

Discovery of a Highly Selective JAK2 Inhibitor, BMS-911543, for the Treatment of Myeloproliferative Neoplasms

PubMed Central

2015-01-01

JAK2 kinase inhibitors are a promising new class of agents for the treatment of myeloproliferative neoplasms and have potential for the treatment of other diseases possessing a deregulated JAK2-STAT pathway. X-ray structure and ADME guided refinement of C-4 heterocycles to address metabolic liability present in dialkylthiazole 1 led to the discovery of a clinical candidate, BMS-911543 (11), with excellent kinome selectivity, in vivo PD activity, and safety profile. PMID:26288683

Functional roles of fibroblast growth factor receptors (FGFRs) signaling in human cancers.

PubMed

Tiong, Kai Hung; Mah, Li Yen; Leong, Chee-Onn

2013-12-01

The fibroblast growth factor receptors (FGFRs) regulate important biological processes including cell proliferation and differentiation during development and tissue repair. Over the past decades, numerous pathological conditions and developmental syndromes have emerged as a consequence of deregulation in the FGFRs signaling network. This review aims to provide an overview of FGFR family, their complex signaling pathways in tumorigenesis, and the current development and application of therapeutics targeting the FGFRs signaling for treatment of refractory human cancers.

Graded effects of unregulated smooth muscle myosin on intestinal architecture, intestinal motility and vascular function in zebrafish.

PubMed

Abrams, Joshua; Einhorn, Zev; Seiler, Christoph; Zong, Alan B; Sweeney, H Lee; Pack, Michael

2016-05-01

Smooth muscle contraction is controlled by the regulated activity of the myosin heavy chain ATPase (Myh11). Myh11 mutations have diverse effects in the cardiovascular, digestive and genitourinary systems in humans and animal models. We previously reported a recessive missense mutation, meltdown (mlt), which converts a highly conserved tryptophan to arginine (W512R) in the rigid relay loop of zebrafish Myh11. The mlt mutation disrupts myosin regulation and non-autonomously induces invasive expansion of the intestinal epithelium. Here, we report two newly identified missense mutations in the switch-1 (S237Y) and coil-coiled (L1287M) domains of Myh11 that fail to complement mlt Cell invasion was not detected in either homozygous mutant but could be induced by oxidative stress and activation of oncogenic signaling pathways. The smooth muscle defect imparted by the mlt and S237Y mutations also delayed intestinal transit, and altered vascular function, as measured by blood flow in the dorsal aorta. The cell-invasion phenotype induced by the three myh11 mutants correlated with the degree of myosin deregulation. These findings suggest that the vertebrate intestinal epithelium is tuned to the physical state of the surrounding stroma, which, in turn, governs its response to physiologic and pathologic stimuli. Genetic variants that alter the regulation of smooth muscle myosin might be risk factors for diseases affecting the intestine, vasculature, and other tissues that contain smooth muscle or contractile cells that express smooth muscle proteins, particularly in the setting of redox stress. © 2016. Published by The Company of Biologists Ltd.

The mTOR signalling pathway in cancer and the potential mTOR inhibitory activities of natural phytochemicals.

PubMed

Tan, Heng Kean; Moad, Ahmed Ismail Hassan; Tan, Mei Lan

2014-01-01

The mammalian target of rapamycin (mTOR) kinase plays an important role in regulating cell growth and cell cycle progression in response to cellular signals. It is a key regulator of cell proliferation and many upstream activators and downstream effectors of mTOR are known to be deregulated in various types of cancers. Since the mTOR signalling pathway is commonly activated in human cancers, many researchers are actively developing inhibitors that target key components in the pathway and some of these drugs are already on the market. Numerous preclinical investigations have also suggested that some herbs and natural phytochemicals, such as curcumin, resveratrol, timosaponin III, gallic acid, diosgenin, pomegranate, epigallocatechin gallate (EGCC), genistein and 3,3'-diindolylmethane inhibit the mTOR pathway either directly or indirectly. Some of these natural compounds are also in the clinical trial stage. In this review, the potential anti-cancer and chemopreventive activities and the current status of clinical trials of these phytochemicals are discussed.

Airline Deregulation and Public Policy

NASA Astrophysics Data System (ADS)

Morrison, Steven A.; Winston, Clifford

1989-08-01

An assessment of the effects of airline deregulation on travelers and carriers indicates that deregulation has provided travelers and carriers with 14.9 billion of annual benefits (1988 dollars). Airport congestion, airline safety, airline bankruptcy, and mergers are also analyzed and found in most cases to have reduced benefits. But, these costs should not be attributed to deregulation per se, but to failures by the government to pursue appropriate policies in these areas. Pursuit of policies that promote airline competition and efficient use of airport capacity would significantly increase the benefits from deregulation and would provide valuable guidance for other industries undergoing the transition to deregulation.

Does deregulation in community pharmacy impact accessibility of medicines, quality of pharmacy services and costs? Evidence from nine European countries.

PubMed

Vogler, Sabine; Habimana, Katharina; Arts, Danielle

2014-09-01

To analyse the impact of deregulation in community pharmacy on accessibility of medicines, quality of pharmacy services and costs. We analysed and compared community pharmacy systems in five rather deregulated countries (England, Ireland, the Netherlands, Norway, Sweden) and four rather regulated countries (Austria, Denmark, Finland, Spain). Data were collected by literature review, a questionnaire survey and interviews. Following a deregulation, several new pharmacies and dispensaries of Over-the-Counter (OTC) medicines tended to be established, predominantly in urban areas. Unless prevented by regulation, specific stakeholders, e.g. wholesalers, were seen to gain market dominance which limited envisaged competition. There were indications for an increased workload for pharmacists in some deregulated countries. Economic pressure to increase the pharmacy turnover through the sale of OTC medicines and non-pharmaceuticals was observed in deregulated and regulated countries. Prices of OTC medicines were not found to decrease after a deregulation in pharmacy. Access to pharmacies usually increases after a deregulation but this is likely to favour urban populations with already good accessibility. Policy-makers are recommended to take action to ensure equitable accessibility and sustainable competition in a more deregulated environment. No association between pharmaceutical expenditure and the extent of regulation/deregulation appears to exist. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

HPV: Molecular pathways and targets.

PubMed

Gupta, Shilpi; Kumar, Prabhat; Das, Bhudev C

2018-04-05

Infection of high-risk human papillomaviruses (HPVs) is a prerequisite for the development of cervical carcinoma. HPV infections are also implicated in the development of other types of carcinomas. Chronic or persistent infection of HPV is essential but HPV alone is inadequate, additional endogenous or exogenous cues are needed along with HPV to induce cervical carcinogenesis. The strategies that high-risk HPVs have developed in differentiating epithelial cells to reach a DNA-synthesis competent state leading to tumorigenic transformation are basically due to overexpression of the E6 and E7 oncoproteins and the activation of diverse cellular regulatory or signaling pathways that are targeted by them. Moreover, the Wnt/β-catenin/Notch and phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) pathways are deregulated in various cancers, and have also been implicated in HPV-induced cancers. These are basically related to the "cancer hallmarks," and include sustaining proliferative signals, the evasion of growth suppression and immune destruction, replicative immortality, inflammation, invasion, metastasis and angiogenesis, as well as genome instability, resisting cell death, and deregulation of cellular energetics. These information could eventually aid in identifying or developing new diagnostic, prognostic biomarkers, and may contribute to design more effective targeted therapeutics and treatment strategies. Although surgery, chemotherapy and radiotherapy can cure more than 90% of women with early stage cervical cancer, the recurrent and metastatic disease remains a major cause of cancer mortality. Numerous efforts have been made to design new drugs and develop gene therapies to treat cervical cancer. In recent years, research on treatment strategies has proposed several options, including the role of HPV E5, E6, and E7 oncogenes, which are retained and overexpressed in most of the cervical cancers and whose respective oncoproteins are critical to the induction and maintenance of the malignant phenotype. Other efforts have been focused on antitumor immunotherapy strategies. It is known that during the development of cervical cancer, a cascade of abnormal events is induced, including disruption of cell cycle control, perturbation of antitumor immune response, alteration of gene expression, deregulation of microRNA and cancer stem cell and stemness related markers expression could serve as novel molecular targets for reliable diagnosis and treatment of HPV-positive cancers. However, the search for new proposals for disease control and prevention has brought new findings and approaches in the context of molecular biology indicating innovations and perspectives in the early detection and prevention of the disease. Thus, in this article, we discuss molecular signaling pathways activated by HPV and potential targets or biomarkers for early detection or prevention and the treatment of HPV-associated cancers. Copyright © 2018 Elsevier Inc. All rights reserved.

Role and Therapeutic Targeting of the HGF/MET Pathway in Glioblastoma

PubMed Central

Cruickshanks, Nichola; Zhang, Ying; Yuan, Fang; Pahuski, Mary; Gibert, Myron; Abounader, Roger

2017-01-01

Glioblastoma (GBM) is a lethal brain tumor with dismal prognosis. Current therapeutic options, consisting of surgery, chemotherapy and radiation, have only served to marginally increase patient survival. Receptor tyrosine kinases (RTKs) are dysregulated in approximately 90% of GBM; attributed to this, research has focused on inhibiting RTKs as a novel and effective therapy for GBM. Overexpression of RTK mesenchymal epithelial transition (MET), and its ligand, hepatocyte growth factor (HGF), in GBM highlights a promising new therapeutic target. This review will discuss the role of MET in cell cycle regulation, cell proliferation, evasion of apoptosis, cell migration and invasion, angiogenesis and therapeutic resistance in GBM. It will also discuss the modes of deregulation of HGF/MET and their regulation by microRNAs. As the HGF/MET pathway is a vital regulator of multiple pro-survival pathways, efforts and strategies for its exploitation for GBM therapy are also described. PMID:28696366

Complement inhibiting properties of dragon's blood from Croton draco.

PubMed

Tsacheva, Ivanka; Rostan, Joerg; Iossifova, Tania; Vogler, Bernhard; Odjakova, Mariela; Navas, Hernan; Kostova, Ivanka; Kojouharova, Michaela; Kraus, Wolfgang

2004-01-01

The latex of Croton draco, its extracts and several latex components have been investigated for their influence on both classical (CP) and alternative (AP) activation pathways of the complement system using a hemolytic assay. The best inhibition was found for the classical pathway. The latex, ethyl acetate and ethyl ether extracts exhibited extremely high inhibition on the CP (94, 90 and 77%, respectively) at a concentration of 1 mg/ml. The flavonoid myricitrin, the alkaloid taspine and the cyclopeptides P1 and P2 showed high inhibition on CP (83, 91, 78 and 63%, respectively) at a concentration of 0.9 mM.

The role of metabolic reprogramming in γ-herpesvirus-associated oncogenesis.

PubMed

Lo, Angela Kwok-Fung; Dawson, Christopher W; Young, Lawrence S; Lo, Kwok-Wai

2017-10-15

The γ-herpesviruses, EBV and KSHV, are closely associated with a number of human cancers. While the signal transduction pathways exploited by γ-herpesviruses to promote cell growth, survival and transformation have been reported, recent studies have uncovered the impact of γ-herpesvirus infection on host cell metabolism. Here, we review the mechanisms used by γ-herpesviruses to induce metabolic reprogramming in host cells, focusing on their ability to modulate the activity of metabolic regulators and manipulate metabolic pathways. While γ-herpesviruses alter metabolic phenotypes as a means to support viral infection and long-term persistence, this modulation can inadvertently contribute to cancer development. Strategies that target deregulated metabolic phenotypes induced by γ-herpesviruses provide new opportunities for therapeutic intervention. © 2017 UICC.

Recent Advances in Microbial Production of Aromatic Chemicals and Derivatives.

PubMed

Noda, Shuhei; Kondo, Akihiko

2017-08-01

Along with the development of metabolic engineering and synthetic biology tools, various microbes are being used to produce aromatic chemicals. In microbes, aromatics are mainly produced via a common important precursor, chorismate, in the shikimate pathway. Natural or non-natural aromatics have been produced by engineering metabolic pathways involving chorismate. In the past decade, novel approaches have appeared to produce various aromatics or to increase their productivity, whereas previously, the targets were mainly aromatic amino acids and the strategy was deregulating feedback inhibition. In this review, we summarize recent studies of microbial production of aromatics based on metabolic engineering approaches. In addition, future perspectives and challenges in this research area are discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Protein Kinases and Phosphatases in the Control of Cell Fate

PubMed Central

Bononi, Angela; Agnoletto, Chiara; De Marchi, Elena; Marchi, Saverio; Patergnani, Simone; Bonora, Massimo; Giorgi, Carlotta; Missiroli, Sonia; Poletti, Federica; Rimessi, Alessandro; Pinton, Paolo

2011-01-01

Protein phosphorylation controls many aspects of cell fate and is often deregulated in pathological conditions. Several recent findings have provided an intriguing insight into the spatial regulation of protein phosphorylation across different subcellular compartments and how this can be finely orchestrated by specific kinases and phosphatases. In this review, the focus will be placed on (i) the phosphoinositide 3-kinase (PI3K) pathway, specifically on the kinases Akt and mTOR and on the phosphatases PP2a and PTEN, and on (ii) the PKC family of serine/threonine kinases. We will look at general aspects of cell physiology controlled by these kinases and phosphatases, highlighting the signalling pathways that drive cell division, proliferation, and apoptosis. PMID:21904669

Necroptosis and Cancer

PubMed Central

Najafov, Ayaz; Chen, Hongbo; Yuan, Junying

2017-01-01

Necroptosis is a programmed lytic cell death pathway, deregulation of which is linked to various inflammatory disorders. Escape from programmed cell death and inflammation play a significant role in cancer, and therefore, investigating the role of necroptosis in cancer has been of high interest. Necroptosis has been shown to promote cancer metastasis and T cells death. Escape from necroptosis via loss of RIPK3 expression is a feature of some cancers. While necroptosis is a promising novel target for cancer therapies, further investigation into its biological role in carcinogenesis is warranted. In this article, we review the recently-identified interplay points between necroptosis and cancer, and outline major biological questions that require further inquiry on the road to targeting this pathway in cancer. PMID:28451648

The alternative complement component factor B regulates UV-induced oedema, systemic suppression of contact and delayed hypersensitivity, and mast cell infiltration into the skin.

PubMed

Byrne, Scott N; Hammond, Kirsten J L; Chan, Carling Y-Y; Rogers, Linda J; Beaugie, Clare; Rana, Sabita; Marsh-Wakefield, Felix; Thurman, Joshua M; Halliday, Gary M

2015-04-01

Ultraviolet (UV) wavelengths in sunlight are the prime cause of skin cancer in humans with both the UVA and UVB wavebands making a contribution to photocarcinogenesis. UV has many different biological effects on the skin that contribute to carcinogenesis, including suppression of adaptive immunity, sunburn and altering the migration of mast cells into and away from irradiated skin. Many molecular mechanisms have been identified as contributing to skin responses to UV. Recently, using gene set enrichment analysis of microarray data, we identified the alternative complement pathway with a central role for factor B (fB) in UVA-induced immunosuppression. In the current study we used mice genetically deficient in fB (fB-/- mice) to study the functional role of the alternative complement pathway in skin responses to UV. We found that fB is required for not only UVA but also UVB-induced immunosuppression and solar-simulated UV induction of the oedemal component of sunburn. Factor B-/- mice had a larger number of resident skin mast cells than control mice, but unlike the controls did not respond to UV by increasing mast cell infiltration into the skin. This study provides evidence for a function role for fB in skin responses to UV radiation. Factor B regulates UVA and UVB induced immunosuppression, UV induced oedema and mast cell infiltration into the skin. The alternative complement pathway is therefore an important regulator of skin responses to UV.

Hepatic expression of the GH/JAK/STAT/IGF pathway, acute-phase response signalling and complement system are affected in mouse offspring by prenatal and early postnatal exposure to maternal high-protein diet.

PubMed

Vanselow, Jens; Kucia, Marzena; Langhammer, Martina; Koczan, Dirk; Rehfeldt, Charlotte; Metges, Cornelia C

2011-12-01

Effects of pre- and early postnatal exposure to maternal high-protein diets are not well understood. Transcription profiling was performed in male mouse offspring exposed to maternal high-protein diet during pregnancy and/or lactation to identify affected hepatic molecular pathways. Dams were fed isoenergetic diets with control (20% w/w) or high protein levels (40%). The hepatic expression profiles were evaluated by differential microarray analysis 3 days (d3) and 3 weeks (d21) after birth. Offspring from three different high-protein dietary groups, HP (d3, high-protein diet during pregnancy), HPHP (d21, high-protein diet during pregnancy and lactation) and CHP (d21, control diet during pregnancy and high-protein diet during lactation), were compared with age-matched offspring from dams fed control diet. Offspring body and liver mass of all high-protein groups were decreased. Prenatal high-protein diet affected hepatic expression of genes mapping to the acute response/complement system and the GH/JAK/STAT/IGF signalling pathways. Maternal exposure to high-protein diet during lactation affected hepatic gene expression of the same pathways but additionally affected genes mapping to protein, fatty acid, hexose and pyruvate metabolism. (1) Genes of the acute response/complement system and GH/JAK/STAT/IGF pathways were down-regulated in offspring of dams exposed to high-protein diets during pregnancy and/or lactation. (2) Genes related to nutrient and energy metabolism, however, were only affected when high-protein diet was administered during lactation. (3) Modulation of the GH/JAK/STAT/IGF pathway might be responsible for reduced body and liver masses by maternal high-protein diet.

A MEK Inhibitor Abrogates Myeloproliferative Disease in Kras Mutant Mice

PubMed Central

Lyubynska, Natalya; Gorman, Matthew F.; Lauchle, Jennifer O.; Hong, Wan Xing; Akutagawa, Jon K.; Shannon, Kevin; Braun, Benjamin S.

2012-01-01

Chronic and juvenile myelomonocytic leukemias (CMML and JMML) are aggressive myeloproliferative neoplasms that are incurable with conventional chemotherapy. Mutations that deregulate Ras signaling play a central pathogenic role in both disorders, and Mx1-Cre, KrasLSL-G12D mice that express the Kras oncogene develop a fatal disease that closely mimics these two leukemias in humans. Activated Ras controls multiple downstream effectors, but the specific pathways that mediate the leukemogenic effects of hyperactive Ras are unknown. We used PD0325901, a highly selective pharmacological inhibitor of mitogen-activated protein kinase kinase (MEK), a downstream component of the Ras signaling network, to address how deregulated Raf/MEK/ERK signaling drives neoplasm formation in Mx1-Cre, KrasLSL-G12D mice. PD0325901 treatment induced a rapid and sustained reduction in leukocyte counts, enhanced erythropoiesis, prolonged mouse survival, and corrected the aberrant proliferation and differentiation of bone marrow progenitor cells. These responses were due to direct effects of PD0325901 on Kras mutant cells rather than to stimulation of normal hematopoietic cell proliferation. Consistent with the in vivo response, inhibition of MEK reversed the cytokine hypersensitivity characteristic of KrasG12D hematopoietic progenitor cells in vitro. Our data demonstrate that deregulated Raf/MEK/ERK signaling is integral to the growth of Kras-mediated myeloproliferative neoplasias, and further suggest that MEK inhibition could be a useful way to ameliorate functional hematologic abnormalities in patients with CMML and JMML. PMID:21451123

Complement Involvement in Periodontitis: Molecular Mechanisms and Rational Therapeutic Approaches.

PubMed

Hajishengallis, George; Maekawa, Tomoki; Abe, Toshiharu; Hajishengallis, Evlambia; Lambris, John D

2015-01-01

The complement system is a network of interacting fluid-phase and cell surface-associated molecules that trigger, amplify, and regulate immune and inflammatory signaling pathways. Dysregulation of this finely balanced network can destabilize host-microbe homeostasis and cause inflammatory tissue damage. Evidence from clinical and animal model-based studies suggests that complement is implicated in the pathogenesis of periodontitis, a polymicrobial community-induced chronic inflammatory disease that destroys the tooth-supporting tissues. This review discusses molecular mechanisms of complement involvement in the dysbiotic transformation of the periodontal microbiome and the resulting destructive inflammation, culminating in loss of periodontal bone support. These mechanistic studies have additionally identified potential therapeutic targets. In this regard, interventional studies in preclinical models have provided proof-of-concept for using complement inhibitors for the treatment of human periodontitis.

Fibroblast Growth Factor Receptors: From the Oncogenic Pathway to Targeted Therapy.

PubMed

Saichaemchan, S; Ariyawutyakorn, W; Varella-Garcia, M

2016-01-01

The family of fibroblast growth factor (FGFs) and their receptors (FGFRs) regulates vital roles in many biological processes affecting cell proliferation, migration, differentiation and survival. Deregulation of the FGF/FGFR signaling pathway in cancers has been better understood and the main molecular mechanisms responsible for the activation of this pathway are gene mutations, gene fusions and gene amplification. DNA and RNA-based technologies have been used to detect these abnormalities, especially in FGFR1, FGFR2 and FGFR3 and tests have been developed for their detection, but no assay has been proved ideal for molecular diagnosis. Interestingly, the increase in the molecular biology knowledge has supported and assisted the development of therapeutic drugs targeting the most important components of this pathway. Multi- and selective tyrosine kinase inhibitors (TKIs) as well as monoclonal antibodies anti-FGFR are under investigation in preclinical and clinical trials. In this article, we reviewed those aspects with special emphasis on the pathway genomic alterations related to solid tumors, and the molecular diagnostic assays potentially able to stratify patients for the treatment with FGFR TKIs.

Novel targets for prostate cancer chemoprevention

PubMed Central

Sarkar, Fazlul H; Li, Yiwei; Wang, Zhiwei; Kong, Dejuan

2010-01-01

Among many endocrine-related cancers, prostate cancer (PCa) is the most frequent male malignancy, and it is the second most common cause of cancer-related death in men in the United States. Therefore, this review focuses on summarizing the knowledge of molecular signaling pathways in PCa because, in order to better design new preventive strategies for the fight against PCa, documentation of the knowledge on the pathogenesis of PCa at the molecular level is very important. Cancer cells are known to have alterations in multiple cellular signaling pathways; indeed, the development and the progression of PCa are known to be caused by the deregulation of several selective signaling pathways such as the androgen receptor, Akt, nuclear factor-κB, Wnt, Hedgehog, and Notch. Therefore, strategies targeting these important pathways and their upstream and downstream signaling could be promising for the prevention of PCa progression. In this review, we summarize the current knowledge regarding the alterations in cell signaling pathways during the development and progression of PCa, and document compelling evidence showing that these are the targets of several natural agents against PCa progression and its metastases. PMID:20576802

Aberrant activity of NKL homeobox gene NKX3-2 in a T-ALL subset

PubMed Central

Meyer, Corinna; Kaufmann, Maren; Zaborski, Margarete; MacLeod, Roderick A. F.; Drexler, Hans G.

2018-01-01

T-cell acute lymphoblastic leukemia (T-ALL) is a hematopoietic malignancy originating from T-cell progenitors in which differentiation is blocked at early stages. Physiological expression of specific NKL homeobox genes obeys a hematopoietic NKL-code implicated in the process of lymphopoiesis while in differentiated T-cells these genes are silenced. We propose that this developmental expression pattern underlies the observation that NKL homeobox genes are the most ubiquitous group of transcription factors deregulated in T-ALL, including TLX1, TLX3, NKX2-5 and NKX3-1. Here, we describe a novel member of the NKL homeobox gene subclass, NKX3-2 (BAPX1), which is aberrantly activated in 18% of pediatric T-ALL patients analyzed while being normally expressed in developing spleen. Identification of NKX3-2 expression in T-ALL cell line CCRF-CEM qualified these cells to model its deregulation and function in a leukemic context. Genomic and chromosomal analyses demonstrated normal configuration of the NKX3-2 locus at chromosome 4p15, thus excluding cytogenetic dysregulation. Comparative expression profiling analysis of NKX3-2 patient data revealed deregulated activity of BMP- and MAPK-signalling. These candidate pathways were experimentally confirmed to mediate aberrant NKX3-2 expression. We also show that homeobox gene SIX6, plus MIR17HG and GATA3 are downstream targets of NKX3-2 and plausibly contribute to the pathogenesis of this malignancy by suppressing T-cell differentiation. Finally, NKL homeobox gene NKX2-5 was activated by NKX3-2 in CCRF-CEM and by FOXG1 in PEER, representing mutually inhibitory activators of this translocated oncogene. Together, our findings reveal a novel oncogenic NKL homeobox gene subclass member which is aberrantly expressed in a large subset of T-ALL patients and participates in a deregulated gene network likely to arise in developing spleen. PMID:29746601

Aberrant activity of NKL homeobox gene NKX3-2 in a T-ALL subset.

PubMed

Nagel, Stefan; Meyer, Corinna; Kaufmann, Maren; Zaborski, Margarete; MacLeod, Roderick A F; Drexler, Hans G

2018-01-01

T-cell acute lymphoblastic leukemia (T-ALL) is a hematopoietic malignancy originating from T-cell progenitors in which differentiation is blocked at early stages. Physiological expression of specific NKL homeobox genes obeys a hematopoietic NKL-code implicated in the process of lymphopoiesis while in differentiated T-cells these genes are silenced. We propose that this developmental expression pattern underlies the observation that NKL homeobox genes are the most ubiquitous group of transcription factors deregulated in T-ALL, including TLX1, TLX3, NKX2-5 and NKX3-1. Here, we describe a novel member of the NKL homeobox gene subclass, NKX3-2 (BAPX1), which is aberrantly activated in 18% of pediatric T-ALL patients analyzed while being normally expressed in developing spleen. Identification of NKX3-2 expression in T-ALL cell line CCRF-CEM qualified these cells to model its deregulation and function in a leukemic context. Genomic and chromosomal analyses demonstrated normal configuration of the NKX3-2 locus at chromosome 4p15, thus excluding cytogenetic dysregulation. Comparative expression profiling analysis of NKX3-2 patient data revealed deregulated activity of BMP- and MAPK-signalling. These candidate pathways were experimentally confirmed to mediate aberrant NKX3-2 expression. We also show that homeobox gene SIX6, plus MIR17HG and GATA3 are downstream targets of NKX3-2 and plausibly contribute to the pathogenesis of this malignancy by suppressing T-cell differentiation. Finally, NKL homeobox gene NKX2-5 was activated by NKX3-2 in CCRF-CEM and by FOXG1 in PEER, representing mutually inhibitory activators of this translocated oncogene. Together, our findings reveal a novel oncogenic NKL homeobox gene subclass member which is aberrantly expressed in a large subset of T-ALL patients and participates in a deregulated gene network likely to arise in developing spleen.

Tinnitus sensitization: a neurophysiological pathway of chronic complex tinnitus.

PubMed

Zenner, Hans P

2006-01-01

A novel neuro- and psychophysiological pathway for central cognition of tinnitus, i.e. tinnitus sensitization, is presented here. As a complement to the neurophysiological pathway for the conditioned reflex according to Jastreboff, which permits therapeutic procedures to bring about an extinction of the tinnitus (e.g. by the acoustic tinnitus retraining therapy), sensitization can be treated with procedures that act at the cognitive level. Since on the one hand therapeutic extinction procedures (e.g. the therapeutic application of sound) are still to be proven effective in controlled studies, while on the other cognitive interventions such as cognitive behavioral therapies have in fact acquired evidence level IIa in prospective studies, it is indeed appropriate to discuss whether the earlier neurophysiological model of a conditioned reflex is sufficient on its own, and whether in fact it needs to be complemented with the sensitization model.

Enhanced susceptibility to acute pneumococcal otitis media in mice deficient in complement C1qa, factor B, and factor B/C2.

PubMed

Tong, Hua Hua; Li, Yong Xing; Stahl, Gregory L; Thurman, Joshua M

2010-03-01

To define the roles of specific complement activation pathways in host defense against Streptococcus pneumoniae in acute otitis media (AOM), we investigated the susceptibility to AOM in mice deficient in complement factor B and C2 (Bf/C2(-/)(-)), C1qa (C1qa(-/)(-)), and factor B (Bf(-)(/)(-)). Bacterial titers of both S. pneumoniae serotype 6A and 14 in the middle ear lavage fluid samples from Bf/C2(-/)(-), Bf(-)(/)(-), and C1qa(-/)(-) mice were significantly higher than in samples from wild-type mice 24 h after transtympanical infection (P < 0.05) and remained persistently higher in samples from Bf/C2(-/)(-) mice than in samples from wild-type mice. Bacteremia occurred in Bf/C2(-/)(-), Bf(-)(/)(-), and C1qa(-/)(-) mice infected with both strains, but not in wild-type mice. Recruitment of inflammatory cells was paralleled by enhanced production of inflammatory mediators in the middle ear lavage samples from Bf/C2(-/)(-) mice. C3b deposition on both strains was greatest for sera obtained from wild-type mice, followed by C1qa(-)(/)(-) and Bf(-)(/)(-) mice, and least for Bf/C2(-)(/)(-) mice. Opsonophagocytosis and whole-blood killing capacity of both strains were significantly decreased in the presence of sera or whole blood from complement-deficient mice compared to wild-type mice. These findings indicate that both the classical and alternative complement pathways are critical for middle ear immune defense against S. pneumoniae. The reduced capacity of complement-mediated opsonization and phagocytosis in the complement-deficient mice appears to be responsible for the impaired clearance of S. pneumoniae from the middle ear and dissemination to the bloodstream during AOM.

Testing the effectiveness of deregulation in the electric utility industry: A market-based approach

NASA Astrophysics Data System (ADS)

Wang, Manfen

In this paper, I investigate one stated purpose of deregulation in the electric utility industry---to make utility operations more responsive to news releases, a proxy for market forces. My premise is that utilities providing electricity to highly deregulated states will be more responsive to market forces than those providing electricity to non-deregulated states. I employ intraday data from April to June 2001, the year after deregulation, and from 1994, the year before deregulation. I also employ the Brown-Forsythe-Modified Levene (BFL) test to determine the volatility differences between days with released news and days without released news. The results of BFL F tests for the year 2001 indicate that utilities headquartered in and serving states that have undergone substantial deregulation respond to news releases more strongly than those utilities headquartered in and serving states that are still regulated. The BFL F tests for utilities in 1994 confirm the premise that regulated utilities are less responsive to news releases. Finally, I conduct regression tests for utilities, the results of which support the findings from BFL tests---that all utilities serving highly deregulated states show pronounced responses to macroeconomic news releases. It appears that deregulation in the electric utility industry does, in fact, make utility operations more responsive to market forces and that deregulation is effective for states that implement a customer-choice model.

Identification and characterization of properdin in amphioxus: Implications for a functional alternative complement pathway in the basal chordate.

PubMed

Gao, Zhan; Ma, Zengyu; Qu, Baozhen; Jiao, Deyan; Zhang, Shicui

2017-06-01

A complement system operating via the alternative pathway similar to that of vertebrates has been demonstrated in the primitive chordate amphioxus. However, the factor P (fP), a positive regulator of the alternative pathway, remains elusive in amphioxus to date. In this study, we identified and characterized a properdin gene in the amphioxus B. japonicum, BjfP, which represents an archetype of vertebrate properdins. Real-time PCR analysis showed that the BjfP was ubiquitously expressed and its expression was significantly up-regulated following the challenge with bacteria or lipopolysaccharide (LPS) and lipoteichoic acid (LTA). Recombinant BjfP (rBjfP) and its truncated proteins including rTSR1-3, rTSR4-6 and rTSR7-8, were all capable of interacting with both Gram-negative and positive bacteria as well as LPS and LTA. Moreover, rBjfP, rTSR1-3 and rTSR4-6 could also specifically bind to C3b. Importantly, both rTSR1-3 and rTSR4-6 could inhibit the binding of rBjfP to C3b, and thus suppress the activation of the alternative pathway of complement, suggesting the involvement of BjfP in the alternative pathway. This is the first report showing that a properdin protein in invertebrates plays similar roles to vertebrate properdins. Collectively, these data suggest that BjfP might represent the ancient molecule from which vertebrate properdins evolved. Copyright © 2017 Elsevier Ltd. All rights reserved.

Anticomplementary activity of horse IgG and F(ab')2 antivenoms.

PubMed

Squaiella-Baptistão, Carla Cristina; Marcelino, José Roberto; Ribeiro da Cunha, Luiz Eduardo; Gutiérrez, José María; Tambourgi, Denise V

2014-03-01

Envenomation by poisonous animals is a neglected condition according to the World Health Organization (WHO). Antivenoms are included in the WHO Essential Medicines List. It has been assumed that immunoglobulin G (IgG) antivenoms could activate the complement system through Fc and induce early adverse reactions (EARs). However, data in the literature indicate that F(ab')2 fragments can also activate the complement system. Herein, we show that several batches of IgG and F(ab')2 antivenoms from the Butantan, Vital Brazil, and Clodomiro Picado Institutes activated the complement classical pathway and induced the production of C3a; however, only those antivenoms from Clodomiro Picado generated C5a. Different protein profiles (IgG heavy chain, protein contaminants, and aggregates) were observed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analyses. Our results show that various antivenoms from different producers are able to activate the classical pathway of the complement system and generate anaphylatoxins, and these findings suggest that factors, such as composition, contaminant proteins, and aggregates, may influence the anticomplementary activity of antivenoms in vitro. Therefore, there is a need to further improve antivenom production methods to reduce their anticomplementary activity and potential to cause EARs.

High-Mobility Group Box 1-Induced Complement Activation Causes Sterile Inflammation.

PubMed

Kim, Sook Young; Son, Myoungsun; Lee, Sang Eun; Park, In Ho; Kwak, Man Sup; Han, Myeonggil; Lee, Hyun Sook; Kim, Eun Sook; Kim, Jae-Young; Lee, Jong Eun; Choi, Ji Eun; Diamond, Betty; Shin, Jeon-Soo

2018-01-01

High-mobility group box 1 (HMGB1), a well-known danger-associated molecular pattern molecule, acts as a pro-inflammatory molecule when secreted by activated immune cells or released after necrotic cell damage. HMGB1 binds to immunogenic bacterial components and augments septic inflammation. In this study, we show how HMGB1 mediates complement activation, promoting sterile inflammation. We show that HMGB1 activates the classical pathway of complement system in an antibody-independent manner after binding to C1q. The C3a complement activation product in human plasma and C5b-9 membrane attack complexes on cell membrane surface are detected after the addition of HMGB1. In an acetaminophen (APAP)-induced hepatotoxicity model, APAP injection reduced HMGB1 levels and elevated C3 levels in C1q-deficient mouse serum samples, compared to that in wild-type (WT) mice. APAP-induced C3 consumption was inhibited by sRAGE treatment in WT mice. Moreover, in a mouse model of brain ischemia-reperfusion injury based on middle cerebral arterial occlusion, C5b-9 complexes were deposited on vessels where HMGB1 was accumulated, an effect that was suppressed upon HMGB1 neutralization. We propose that the HMGB1 released after cell necrosis and in ischemic condition can trigger the classical pathway of complement activation to exacerbate sterile inflammation.

High-Mobility Group Box 1-Induced Complement Activation Causes Sterile Inflammation

PubMed Central

Kim, Sook Young; Son, Myoungsun; Lee, Sang Eun; Park, In Ho; Kwak, Man Sup; Han, Myeonggil; Lee, Hyun Sook; Kim, Eun Sook; Kim, Jae-Young; Lee, Jong Eun; Choi, Ji Eun; Diamond, Betty; Shin, Jeon-Soo

2018-01-01

High-mobility group box 1 (HMGB1), a well-known danger-associated molecular pattern molecule, acts as a pro-inflammatory molecule when secreted by activated immune cells or released after necrotic cell damage. HMGB1 binds to immunogenic bacterial components and augments septic inflammation. In this study, we show how HMGB1 mediates complement activation, promoting sterile inflammation. We show that HMGB1 activates the classical pathway of complement system in an antibody-independent manner after binding to C1q. The C3a complement activation product in human plasma and C5b-9 membrane attack complexes on cell membrane surface are detected after the addition of HMGB1. In an acetaminophen (APAP)-induced hepatotoxicity model, APAP injection reduced HMGB1 levels and elevated C3 levels in C1q-deficient mouse serum samples, compared to that in wild-type (WT) mice. APAP-induced C3 consumption was inhibited by sRAGE treatment in WT mice. Moreover, in a mouse model of brain ischemia–reperfusion injury based on middle cerebral arterial occlusion, C5b-9 complexes were deposited on vessels where HMGB1 was accumulated, an effect that was suppressed upon HMGB1 neutralization. We propose that the HMGB1 released after cell necrosis and in ischemic condition can trigger the classical pathway of complement activation to exacerbate sterile inflammation. PMID:29696019

Transcriptomic profiling of Melon necrotic spot virus-infected melon plants revealed virus strain and plant cultivar-specific alterations.

PubMed

Gómez-Aix, Cristina; Pascual, Laura; Cañizares, Joaquín; Sánchez-Pina, María Amelia; Aranda, Miguel A

2016-06-07

Viruses are among the most destructive and difficult to control plant pathogens. Melon (Cucumis melo L.) has become the model species for the agriculturally important Cucurbitaceae family. Approaches that take advantage of recently developed genomic tools in melon have been extremely useful for understanding viral pathogenesis and can contribute to the identification of target genes for breeding new resistant cultivars. In this work, we have used a recently described melon microarray for transcriptome profiling of two melon cultivars infected with two strains of Melon necrotic spot virus (MNSV) that only differ on their 3'-untranslated regions. Melon plant tissues from the cultivars Tendral or Planters Jumbo were locally infected with either MNSV-Mα5 or MNSV-Mα5/3'264 and analysed in a time-course experiment. Principal component and hierarchical clustering analyses identified treatment (healthy vs. infected) and sampling date (3 vs. 5 dpi) as the primary and secondary variables, respectively. Out of 7566 and 7074 genes deregulated by MNSV-Mα5 and MNSV-Mα5/3'264, 1851 and 1356, respectively, were strain-specific. Likewise, MNSV-Mα5/3'264 specifically deregulated 2925 and 1618 genes in Tendral and Planters Jumbo, respectively. The GO categories that were significantly affected were clearly different for the different virus/host combinations. Grouping genes according to their patterns of expression allowed for the identification of two groups that were specifically deregulated by MNSV-Mα5/3'264 with respect to MNSV-Mα5 in Tendral, and one group that was antagonistically regulated in Planters Jumbo vs. Tendral after MNSV-Mα5/3'264 infection. Genes in these three groups belonged to diverse functional classes, and no obvious regulatory commonalities were identified. When data on MNSV-Mα5/Tendral infections were compared to equivalent data on cucumber mosaic virus or watermelon mosaic virus infections, cytokinin-O-glucosyltransferase2 was identified as the only gene that was deregulated by all three viruses, with infection dynamics correlating with the amplitude of transcriptome remodeling. Strain-specific changes, as well as cultivar-specific changes, were identified by profiling the transcriptomes of plants from two melon cultivars infected with two MNSV strains. No obvious regulatory features shared among deregulated genes have been identified, pointing toward regulation through differential functional pathways.

Cloning and characterization of the Bacillus subtilis birA gene encoding a repressor of the biotin operon.

PubMed

Bower, S; Perkins, J; Yocum, R R; Serror, P; Sorokin, A; Rahaim, P; Howitt, C L; Prasad, N; Ehrlich, S D; Pero, J

1995-05-01

The Bacillus subtilis birA gene, which regulates biotin biosynthesis, has been cloned and characterized. The birA gene maps at 202 degrees on the B. subtilis chromosome and encodes a 36,200-Da protein that is 27% identical to Escherichia coli BirA protein. Three independent mutations in birA that lead to deregulation of biotin synthesis alter single amino acids in the amino-terminal end of the protein. The amino-terminal region that is affected by these three birA mutations shows sequence similarity to the helix-turn-helix DNA binding motif previously identified in E. coli BirA protein. B. subtilis BirA protein also possesses biotin-protein ligase activity, as judged by its ability to complement a conditional lethal birA mutant of E. coli.

Cloning and characterization of the Bacillus subtilis birA gene encoding a repressor of the biotin operon.

PubMed Central

Bower, S; Perkins, J; Yocum, R R; Serror, P; Sorokin, A; Rahaim, P; Howitt, C L; Prasad, N; Ehrlich, S D; Pero, J

1995-01-01

The Bacillus subtilis birA gene, which regulates biotin biosynthesis, has been cloned and characterized. The birA gene maps at 202 degrees on the B. subtilis chromosome and encodes a 36,200-Da protein that is 27% identical to Escherichia coli BirA protein. Three independent mutations in birA that lead to deregulation of biotin synthesis alter single amino acids in the amino-terminal end of the protein. The amino-terminal region that is affected by these three birA mutations shows sequence similarity to the helix-turn-helix DNA binding motif previously identified in E. coli BirA protein. B. subtilis BirA protein also possesses biotin-protein ligase activity, as judged by its ability to complement a conditional lethal birA mutant of E. coli. PMID:7730294

Using animal models to determine the significance of complement activation in Alzheimer's disease

PubMed Central

Loeffler, David A

2004-01-01

Complement inflammation is a major inflammatory mechanism whose function is to promote the removal of microorganisms and the processing of immune complexes. Numerous studies have provided evidence for an increase in this process in areas of pathology in the Alzheimer's disease (AD) brain. Because complement activation proteins have been demonstrated in vitro to exert both neuroprotective and neurotoxic effects, the significance of this process in the development and progression of AD is unclear. Studies in animal models of AD, in which brain complement activation can be experimentally altered, should be of value for clarifying this issue. However, surprisingly little is known about complement activation in the transgenic animal models that are popular for studying this disorder. An optimal animal model for studying the significance of complement activation on Alzheimer's – related neuropathology should have complete complement activation associated with senile plaques, neurofibrillary tangles (if present), and dystrophic neurites. Other desirable features include both classical and alternative pathway activation, increased neuronal synthesis of native complement proteins, and evidence for an increase in complement activation prior to the development of extensive pathology. In order to determine the suitability of different animal models for studying the role of complement activation in AD, the extent of complement activation and its association with neuropathology in these models must be understood. PMID:15479474

Intricacies of hedgehog signaling pathways: A perspective in tumorigenesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kar, Swayamsiddha; Deb, Moonmoon; Sengupta, Dipta

The hedgehog (HH) signaling pathway is a crucial negotiator of developmental proceedings in the embryo governing a diverse array of processes including cell proliferation, differentiation, and tissue patterning. The overall activity of the pathway is significantly curtailed after embryogenesis as well as in adults, yet it retains many of its functional capacities. However, aberration in HH signaling mediates the initiation, proliferation and continued sustenance of malignancy in different tissues to varying degrees through different mechanisms. In this review, we provide an overview of the role of constitutively active aberrant HH signaling pathway in different types of human cancer and themore » underlying molecular and genetic mechanisms that drive tumorigenesis in that particular tissue. An insight into the various modes of anomalous HH signaling in different organs will provide a comprehensive knowledge of the pathway in these tissues and open a window for individually tailored, tissue-specific therapeutic interventions. The synergistic cross talking of HH pathway with many other regulatory molecules and developmentally inclined signaling pathways may offer many avenues for pharmacological advances. Understanding the molecular basis of abnormal HH signaling in cancer will provide an opportunity to inhibit the deregulated pathway in many aggressive and therapeutically challenging cancers where promising options are not available.« less

Pathway-related modules involved in the application of sevoflurane or propofol in off-pump coronary artery bypass graft surgery.

PubMed

Bu, Xiangmei; Wang, Bo; Wang, Yaoqi; Wang, Zhigang; Gong, Chunzhi; Qi, Feng; Zhang, Caixia

2017-07-01

Off-pump coronary artery bypass graft (CABG) surgery has recently emerged as a means to avoid the sequelae of extracorporeal circulation, including the whole-body inflammatory response, coagulation disorders and multiple organ dysfunction. At present, gas anesthesia, sevoflurane and intravenous anesthesia and propofol have been widely used during the CABG. To further understand the underlying mechanisms of these anesthetics on the gene level, the present study conducted pathway-related module analysis based on a co-expression network. This was performed in order to identify significant pathways in coronary artery disease patients who had undergone off-pump CABG surgery before and after applying sevoflurane or propofol. A total of 269 and 129 differentially expressed genes were obtained in the sevoflurane and propofol groups, respectively. In total, eight and seven pathways (P<0.05) in the sevoflurane and propofol groups were separately obtained via Kyoto Encyclopedia of Genes and Genome pathway analysis. Finally, eight and seven pathway-related modules in the sevoflurane and propofol groups were obtained, respectively. Furthermore, the mean degree of complement and coagulation cascades pathway-related module in both of the groups was the highest. It was predicted that during the CABG, the anesthetics might activate the complement and coagulation systems in order to possess some cardioprotective properties.

Identification of deregulation of apoptosis and cell cycle in neuroendocrine tumors of the lung via NanoString nCounter expression analysis

PubMed Central

Walter, Robert Fred Henry; Werner, Robert; Ting, Saskia; Vollbrecht, Claudia; Theegarten, Dirk; Christoph, Daniel Christian; Schmid, Kurt Werner; Wohlschlaeger, Jeremias; Mairinger, Fabian Dominik

2015-01-01

Background Neuroendocrine tumors of the lung comprise typical (TC) and atypical carcinoids (AC), large-cell neuroendocrine cancer (LCNEC) and small-cell lung cancer (SCLC). Cell cycle and apoptosis are key pathways of multicellular homeostasis and deregulation of these pathways is associated with cancerogenesis. Materials and Methods Sixty representative FFPE-specimens (16 TC, 13 AC, 16 LCNEC and 15 SCLC) were used for mRNA expression analysis using the NanoString technique. Eight genes related to apoptosis and ten genes regulating key points of cell cycle were investigated. Results ASCL1, BCL2, CASP8, CCNE1, CDK1, CDK2, CDKN1A and CDKN2A showed lower expression in carcinoids compared to carcinomas. In contrast, CCNE1 and CDK6 showed elevated expression in carcinoids compared to carcinomas. The calculated BCL2/BAX ratio showed increasing values from TC to SCLC. Between SCLC and LCNEC CDK2, CDKN1B, CDKN2A and PNN expression was significantly different with higher expression in SCLC. Conclusion Carcinoids have increased CDK4/6 and CCND1 expression controlling RB1 phosphorylation via this signaling cascade. CDK2 and CCNE1 were increased in carcinomas showing that these use the opposite way to control RB1. BAX and BCL2 are antagonists in regulating apoptosis. BCL2 expression increased over BAX expression with increasing malignancy of the tumor from TC to SCLC. PMID:26008974

ODC1 is a critical determinant of MYCN oncogenesis and a therapeutic target in neuroblastoma

PubMed Central

Hogarty, Michael D.; Norris, Murray D.; Davis, Kim; Liu, Xueyuan; Evageliou, Nicholas F.; Hayes, Candace S.; Pawel, Bruce; Guo, Rong; Zhao, Huaqing; Sekyere, Eric; Keating, Joanna; Thomas, Wayne; Cheng, Ngan Ching; Murray, Jayne; Smith, Janice; Sutton, Rosemary; Venn, Nicola; London, Wendy B.; Buxton, Allan; Gilmour, Susan K.; Marshall, Glenn M; Haber, Michelle

2008-01-01

Neuroblastoma is a frequently lethal childhood tumor in which MYC gene deregulation, commonly as MYCN amplification, portends poor outcome. Identifying the requisite biopathways downstream of MYC may provide therapeutic opportunities. We used transcriptome analyses to show that MYCN-amplified neuroblastomas have co-ordinately deregulated myriad polyamine enzymes (including ODC1, SRM, SMS, AMD1, OAZ2, and SMOX) to enhance polyamine biosynthesis. High-risk tumors without MYCN amplification also overexpress ODC1, the rate-limiting enzyme in polyamine biosynthesis, when compared with lower risk tumors, suggesting this pathway may be pivotal. Indeed, elevated ODC1 (independent of MYCN amplification) was associated with reduced survival in a large independent neuroblastoma cohort. As polyamines are essential for cell survival and linked to cancer progression, we studied polyamine antagonism to test for metabolic dependence on this pathway in neuroblastoma. The Odc inhibitor α-difluoromethylornithine (DFMO) inhibited neuroblast proliferation in vitro and suppressed oncogenesis in vivo. DFMO treatment of neuroblastoma-prone genetically-engineered mice (TH-MYCN GEM) extended tumor latency and survival in homozygous mice, and prevented oncogenesis in hemizygous mice. In the latter, transient Odc ablation permanently prevented tumor onset consistent with a time-limited window for embryonal tumor initiation. Importantly, we show that DFMO augments anti-tumor efficacy of conventional cytotoxics in vivo. This work implicates polyamine biosynthesis as an arbiter of MYCN oncogenesis and demonstrates initial efficacy for polyamine depletion strategies in neuroblastoma, a strategy that may have utility for this and other MYC-driven embryonal tumors. PMID:19047152

ODC1 is a critical determinant of MYCN oncogenesis and a therapeutic target in neuroblastoma.

PubMed

Hogarty, Michael D; Norris, Murray D; Davis, Kimberly; Liu, Xueyuan; Evageliou, Nicholas F; Hayes, Candace S; Pawel, Bruce; Guo, Rong; Zhao, Huaqing; Sekyere, Eric; Keating, Joanna; Thomas, Wayne; Cheng, Ngan Ching; Murray, Jayne; Smith, Janice; Sutton, Rosemary; Venn, Nicola; London, Wendy B; Buxton, Allen; Gilmour, Susan K; Marshall, Glenn M; Haber, Michelle

2008-12-01

Neuroblastoma is a frequently lethal childhood tumor in which MYC gene deregulation, commonly as MYCN amplification, portends poor outcome. Identifying the requisite biopathways downstream of MYC may provide therapeutic opportunities. We used transcriptome analyses to show that MYCN-amplified neuroblastomas have coordinately deregulated myriad polyamine enzymes (including ODC1, SRM, SMS, AMD1, OAZ2, and SMOX) to enhance polyamine biosynthesis. High-risk tumors without MYCN amplification also overexpress ODC1, the rate-limiting enzyme in polyamine biosynthesis, when compared with lower-risk tumors, suggesting that this pathway may be pivotal. Indeed, elevated ODC1 (independent of MYCN amplification) was associated with reduced survival in a large independent neuroblastoma cohort. As polyamines are essential for cell survival and linked to cancer progression, we studied polyamine antagonism to test for metabolic dependence on this pathway in neuroblastoma. The Odc inhibitor alpha-difluoromethylornithine (DFMO) inhibited neuroblast proliferation in vitro and suppressed oncogenesis in vivo. DFMO treatment of neuroblastoma-prone genetically engineered mice (TH-MYCN) extended tumor latency and survival in homozygous mice and prevented oncogenesis in hemizygous mice. In the latter, transient Odc ablation permanently prevented tumor onset consistent with a time-limited window for embryonal tumor initiation. Importantly, we show that DFMO augments antitumor efficacy of conventional cytotoxics in vivo. This work implicates polyamine biosynthesis as an arbiter of MYCN oncogenesis and shows initial efficacy for polyamine depletion strategies in neuroblastoma, a strategy that may have utility for this and other MYC-driven embryonal tumors.

Copy number profiling of adult relapsed B-cell precursor acute lymphoblastic leukemia reveals potential leukemia progression mechanisms.

PubMed

Ribera, Jordi; Zamora, Lurdes; Morgades, Mireia; Mallo, Mar; Solanes, Neus; Batlle, Montserrat; Vives, Susana; Granada, Isabel; Juncà, Jordi; Malinverni, Roberto; Genescà, Eulàlia; Guàrdia, Ramon; Mercadal, Santiago; Escoda, Lourdes; Martinez-Lopez, Joaquín; Tormo, Mar; Esteve, Jordi; Pratcorona, Marta; Martinez-Losada, Carmen; Solé, Francesc; Feliu, Evarist; Ribera, Josep-Maria

2017-11-01

The outcome of relapsed adult acute lymphoblastic leukemia (ALL) remains dismal despite new therapeutic approaches. Previous studies analyzing relapse samples have shown a high degree of heterogeneity regarding gene alterations without an evident relapse signature. Bone marrow or peripheral blood samples from 31 adult B-cell precursor ALL patients at first relapse, and 21 paired diagnostic samples were analyzed by multiplex ligation probe-dependent amplification (MLPA). Nineteen paired diagnostic and relapse samples of these 21 patients were also analyzed by SNP arrays. A trend to acquire homozygous CDKN2A/B deletions and a significant increase in the number of copy number alterations (CNA) was observed from diagnosis to first relapse. Evolution from an ancestral clone was the main pattern of clonal evolution. Relapse samples were extremely heterogeneous regarding CNA frequencies. However, CDKN2A/B, PAX5, ETV6, ATM, IKZF1, VPREB1, and TP53 deletions and duplications of 1q, 8q, 17q, 21, X/Y PAR1, and Xp were frequently detected at relapse. Duplications of genes involved in cell proliferation, drug resistance and stem cell homeostasis regulation, as well as deletions of KDM6A and STAG2 genes emerged as specific alterations at relapse. Genomics of relapsed adult B-cell precursor ALL is highly heterogeneous, although some recurrent lesions involved in essential pathways deregulation were frequently observed. Selective and simultaneous targeting of these deregulated pathways may improve the results of current salvage therapies. © 2017 Wiley Periodicals, Inc.

Apoptosis transcriptional mechanism of feline infectious peritonitis virus infected cells.

PubMed

Shuid, Ahmad Naqib; Safi, Nikoo; Haghani, Amin; Mehrbod, Parvaneh; Haron, Mohd Syamsul Reza; Tan, Sheau Wei; Omar, Abdul Rahman

2015-11-01

Apoptosis has been postulated to play an important role during feline infectious peritonitis virus (FIPV) infection; however, its mechanism is not well characterized. This study is focused on apoptosis and transcriptional profiling of FIPV-infected cells following in vitro infection of CRFK cells with FIPV 79-1146 WSU. Flow cytometry was used to determine mode of cell death in first 42 h post infection (hpi). FIPV infected cells underwent early apoptosis at 9 hpi (p < 0.05) followed by late apoptosis at 12 hpi (p < 0.05) and necrosis from 24 hpi (p < 0.05). Then, next generation sequencing was performed on 9 hpi and control uninfected cells by Illumina analyzer. An aggregate of 4546 genes (2229 down-regulated and 2317 up-regulated) from 17 cellular process, 11 molecular functions and 130 possible biological pathways were affected by FIPV. 131 genes from apoptosis cluster (80 down-regulated and 51 up-regulated) along with increase of apoptosis, p53, p38 MAPK, VEGF and chemokines/cytokines signaling pathways were probably involved in apoptosis process. Six of the de-regulated genes expression (RASSF1, BATF2, MAGEB16, PDCD5, TNFα and TRAF2) and TNFα protein concentration were analyzed by RT-qPCR and ELISA, respectively, at different time-points. Up-regulations of both pro-apoptotic (i.e. PDCD5) and anti-apoptotic (i.e. TRAF2) were detected from first hpi and continuing to deregulate during apoptosis process in the infected cells.

Acute WNT signalling activation perturbs differentiation within the adult stomach and rapidly leads to tumour formation

PubMed Central

Radulescu, S; Ridgway, R A; Cordero, J; Athineos, D; Salgueiro, P; Poulsom, R; Neumann, J; Jung, A; Patel, S; Woodgett, J; Barker, N; Pritchard, D M; Oien, K; Sansom, O J

2013-01-01

A role for WNT signalling in gastric carcinogenesis has been suggested due to two major observations. First, patients with germline mutations in adenomatous polyposis coli (APC) are susceptible to stomach polyps and second, in gastric cancer, WNT activation confers a poor prognosis. However, the functional significance of deregulated WNT signalling in gastric homoeostasis and cancer is still unclear. In this study we have addressed this by investigating the immediate effects of WNT signalling activation within the stomach epithelium. We have specifically activated the WNT signalling pathway within the mouse adult gastric epithelium via deletion of either glycogen synthase kinase 3 (GSK3) or APC or via expression of a constitutively active β-catenin protein. WNT pathway deregulation dramatically affects stomach homoeostasis at very short latencies. In the corpus, there is rapid loss of parietal cells with fundic gland polyp (FGP) formation and adenomatous change, which are similar to those observed in familial adenomatous polyposis. In the antrum, adenomas occur from 4 days post-WNT activation. Taken together, these data show a pivotal role for WNT signalling in gastric homoeostasis, FGP formation and adenomagenesis. Loss of the parietal cell population and corresponding FGP formation, an early event in gastric carcinogenesis, as well as antral adenoma formation are immediate effects of nuclear β-catenin translocation and WNT target gene expression. Furthermore, our inducible murine model will permit a better understanding of the molecular changes required to drive tumourigenesis in the stomach. PMID:22665058

The mTORC1-4E-BP-eIF4E axis controls de novo Bcl6 protein synthesis in T cells and systemic autoimmunity.

PubMed

Yi, Woelsung; Gupta, Sanjay; Ricker, Edd; Manni, Michela; Jessberger, Rolf; Chinenov, Yurii; Molina, Henrik; Pernis, Alessandra B

2017-08-15

Post-transcriptional modifications can control protein abundance, but the extent to which these alterations contribute to the expression of T helper (T H ) lineage-defining factors is unknown. Tight regulation of Bcl6 expression, an essential transcription factor for T follicular helper (T FH ) cells, is critical as aberrant T FH cell expansion is associated with autoimmune diseases, such as systemic lupus erythematosus (SLE). Here we show that lack of the SLE risk variant Def6 results in deregulation of Bcl6 protein synthesis in T cells as a result of enhanced activation of the mTORC1-4E-BP-eIF4E axis, secondary to aberrant assembly of a raptor-p62-TRAF6 complex. Proteomic analysis reveals that this pathway selectively controls the abundance of a subset of proteins. Rapamycin or raptor deletion ameliorates the aberrant T FH cell expansion in mice lacking Def6. Thus deregulation of mTORC1-dependent pathways controlling protein synthesis can result in T-cell dysfunction, indicating a mechanism by which mTORC1 can promote autoimmunity.Excessive expansion of the T follicular helper (T FH ) cell pool is associated with autoimmune disease and Def6 has been identified as an SLE risk variant. Here the authors show that Def6 limits proliferation of T FH cells in mice via alteration of mTORC1 signaling and inhibition of Bcl6 expression.

Integrated genomic analyses identify KDM1A's role in cell proliferation via modulating E2F signaling activity and associate with poor clinical outcome in oral cancer.

PubMed

Narayanan, Sathiya Pandi; Singh, Smriti; Gupta, Amit; Yadav, Sandhya; Singh, Shree Ram; Shukla, Sanjeev

2015-10-28

The histone demethylase KDM1A specifically demethylates lysine residues and its deregulation has been implicated in the initiation and progression of various cancers. However, KDM1A's molecular role and its pathological consequences, and prognostic significance in oral cancer remain less understood. In the present study, we sought to investigate the expression of KDM1A and its downstream role in oral cancer pathogenesis. By comparing mRNA expression profiles, we identified an elevated KDM1A expression in oral tumors when compared to normal oral tissues. In silico pathway prediction identified the association between KDM1A and E2F1 signaling in oral cancer. Pathway scanning, functional annotation analysis and In vitro assays showed the KDM1A's involvement in oral cancer cell proliferation and the cell cycle. Moreover, real time PCR and luciferase assays confirmed KDM1A's role in regulation of E2F1 signaling activity in oral cancer. Elevated KDM1A expression is associated with poor clinical outcome in oral cancer. Our data indicate that deregulated KDM1A expression is positively associated with proliferative phenotype of oral cancer and confers poor clinical outcome. These cumulative data suggest that KDM1A might be a potential diagnostic and therapeutic target for oral cancer. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

A conceptual framework to advance exposure science research and complement the Adverse Outcome Pathway framework

EPA Science Inventory

A tremendous amount of data on environmental stressors has been accumulated in exposure science, epidemiology, and toxicology, yet most of these data reside in different silos. The Adverse Outcome Pathway (AOP) framework was developed as an organizing principle for toxicological ...

Synergy between the KEAP1/NRF2 and PI3K Pathways Drives Non-Small-Cell Lung Cancer with an Altered Immune Microenvironment.

PubMed

Best, Sarah A; De Souza, David P; Kersbergen, Ariena; Policheni, Antonia N; Dayalan, Saravanan; Tull, Dedreia; Rathi, Vivek; Gray, Daniel H; Ritchie, Matthew E; McConville, Malcolm J; Sutherland, Kate D

2018-04-03

The lung presents a highly oxidative environment, which is tolerated through engagement of tightly controlled stress response pathways. A critical stress response mediator is the transcription factor nuclear factor erythroid-2-related factor 2 (NFE2L2/NRF2), which is negatively regulated by Kelch-like ECH-associated protein 1 (KEAP1). Alterations in the KEAP1/NRF2 pathway have been identified in 23% of lung adenocarcinomas, suggesting that deregulation of the pathway is a major cancer driver. We demonstrate that inactivation of Keap1 and Pten in the mouse lung promotes adenocarcinoma formation. Notably, metabolites identified in the plasma of Keap1 f/f /Pten f/f tumor-bearing mice indicate that tumorigenesis is associated with reprogramming of the pentose phosphate pathway. Furthermore, the immune milieu was dramatically changed by Keap1 and Pten deletion, and tumor regression was achieved utilizing immune checkpoint inhibition. Thus, our study highlights the ability to exploit both metabolic and immune characteristics in the detection and treatment of lung tumors harboring KEAP1/NRF2 pathway alterations. Copyright © 2018 Elsevier Inc. All rights reserved.

O-GlcNAcylation affects β-catenin and E-cadherin expression, cell motility and tumorigenicity of colorectal cancer.

PubMed

Harosh-Davidovich, Shani Ben; Khalaila, Isam

2018-03-01

O-GlcNAcylation, the addition of β-N-acetylglucosamine (O-GlcNAc) moiety to Ser/Thr residues, is a sensor of the cell metabolic state. Cancer diseases such as colon, lung and breast cancer, possess deregulated O-GlcNAcylation. Studies during the last decade revealed that O-GlcNAcylation is implicated in cancer tumorigenesis and proliferation. The Wnt/β-catenin signaling pathway and cadherin-mediated adhesion are also implicated in epithelial-mesenchymal transition (EMT), a key cellular process in invasion and cancer metastasis. Often, deregulation of the Wnt pathway is caused by altered phosphorylation of its components. Specifically, phosphorylation of Ser or Thr residues of β-catenin affects its location and interaction with E-cadherin, thus facilitating cell-cell adhesion. Consistent with previous studies, the current study indicates that β-catenin is O-GlcNAcylated. To test the effect of O-GlcNAcylation on cell motility and how O-GlcNAcylation might affect β-catenin and E-cadherin functions, the enzyme machinery of O-GlcNAcylation was modulated either with chemical inhibitors or by gene silencing. When O-GlcNAcase (OGA) was inhibited, a global elevation of protein O-GlcNAcylation and increase in the expression of E-cadherin and β-catenin were noted. Concomitantly with enhanced O-GlcNAcylation, β-catenin transcriptional activity were elevated. Additionally, fibroblast cell motility was enhanced. Stable silenced cell lines with adenoviral OGA or adenoviral O-GlcNAc transferase (OGT) were established. Consistent with the results obtained by OGA chemical inhibition by TMG, OGT-silencing led to a significant reduction in β-catenin level. In vivo, murine orthotropic colorectal cancer model indicates that elevated O-GlcNAcylation leads to increased mortality rate, tumor and metastasis development. However, reduction in O-GlcNAcylation promoted survival that could be attributed to attenuated tumor and metastasis development. The results described herein provide circumstantial clues that O-GlcNAcylation deregulates β-catenin and E-cadherin expression and activity in fibroblast cell lines and this might influence EMT and cell motility, which may further influence tumor development and metastasis. Copyright © 2018 Elsevier Inc. All rights reserved.

Deregulation, the New Federalism, and Scarcity: The End of Additive Reform.

ERIC Educational Resources Information Center

Doyle, Denis P.

The current trend toward deregulation of education at the federal level will not prove particularly significant if deregulation does not also occur at the state level. The Reagan administration's handling of deregulation has been clumsy, slow, inappropriate, and apparently guided by motivations other than the easing of administrative burdens.…

The renaissance of complement therapeutics

PubMed Central

Ricklin, Daniel; Mastellos, Dimitrios C.; Reis, Edimara S.; Lambris, John D.

2018-01-01

The increasing number of clinical conditions that involve a pathological contribution from the complement system — many of which affect the kidneys — has spurred a regained interest in therapeutic options to modulate this host defence pathway. Molecular insight, technological advances, and the first decade of clinical experience with the complement-specific drug eculizumab, have contributed to a growing confidence in therapeutic complement inhibition. More than 20 candidate drugs that target various stages of the complement cascade are currently being evaluated in clinical trials, and additional agents are in preclinical development. Such diversity is clearly needed in view of the complex and distinct involvement of complement in a wide range of clinical conditions, including rare kidney disorders, transplant rejection and haemodialysis-induced inflammation. The existing drugs cannot be applied to all complement-driven diseases, and each indication has to be assessed individually. Alongside considerations concerning optimal points of intervention and economic factors, patient stratification will become essential to identify the best complement-specific therapy for each individual patient. This Review provides an overview of the therapeutic concepts, targets and candidate drugs, summarizes insights from clinical trials, and reflects on existing challenges for the development of complement therapeutics for kidney diseases and beyond. PMID:29199277

Complement factor H family proteins in their non-canonical role as modulators of cellular functions.

PubMed

Józsi, Mihály; Schneider, Andrea E; Kárpáti, Éva; Sándor, Noémi

2018-01-04

Complement factor H is a major regulator of the alternative pathway of the complement system. The factor H-related proteins are less characterized, but recent data indicate that they rather promote complement activation. These proteins have some common ligands with factor H and have both overlapping and distinct functions depending on domain composition and the degree of conservation of amino acid sequence. Factor H and some of the factor H-related proteins also appear in a non-canonical function that is beyond their role in the modulation of complement activation. This review covers our current understanding on this emerging role of factor H family proteins in modulating the activation and function of various cells by binding to receptors or receptor ligands. Copyright © 2018 Elsevier Ltd. All rights reserved.

Isolation and purification of C3 from human plasma.

PubMed

O'Rear, L D; Ross, G D

2001-05-01

The alternative pathway of complement shares its terminal components (C3 and C5 through 9) with the classical pathway, but has several unique components, including factors D, B, and P (properdin). This unit presents methods for assaying total alternative pathway activity and the activity of factors B and D. Radial immunodiffusion (RID) can also be used to measure factor D, B, and P concentrations.

The Complement System and Adverse Pregnancy Outcomes

PubMed Central

Regal, Jean F.; Gilbert, Jeffrey S.; Burwick, Richard M.

2015-01-01

Adverse pregnancy outcomes significantly contribute to morbidity and mortality for mother and child, with lifelong health consequences for both. The innate and adaptive immune system must be regulated to insure survival of the feta allograft, and the complement system is no exception. An intact complement system optimizes placental development and function and is essential to maintain host defense and fetal survival. Complement regulation is apparent at the placental interface from early pregnancy with some degree of complement activation occurring normally throughout gestation. However, a number of pregnancy complications including early pregnancy loss, fetal growth restriction, hypertensive disorders of pregnancy and preterm birth are associated with excessive or misdirected complement activation, and are more frequent in women with inherited or acquired complement system disorders or complement gene mutations. Clinical studies employing complement biomarkers in plasma and urine implicate dysregulated complement activation in components of each of the adverse pregnancy outcomes. In addition, mechanistic studies in rat and mouse models of adverse pregnancy outcomes address the complement pathways or activation products of importance and allow critical analysis of the pathophysiology. Targeted complement therapeutics are already in use to control adverse pregnancy outcomes in select situations. A clearer understanding of the role of the complement system in both normal pregnancy and complicated or failed pregnancy will allow a rational approach to future therapeutic strategies for manipulating complement with the goal of mitigating adverse pregnancy outcomes, preserving host defense, and improving long term outcomes for both mother and child. PMID:25802092

UV Light Potentiates STING (Stimulator of Interferon Genes)-dependent Innate Immune Signaling through Deregulation of ULK1 (Unc51-like Kinase 1)*

PubMed Central

Kemp, Michael G.; Lindsey-Boltz, Laura A.; Sancar, Aziz

2015-01-01

The mechanism by which ultraviolet (UV) wavelengths of sunlight trigger or exacerbate the symptoms of the autoimmune disorder lupus erythematosus is not known but may involve a role for the innate immune system. Here we show that UV radiation potentiates STING (stimulator of interferon genes)-dependent activation of the immune signaling transcription factor interferon regulatory factor 3 (IRF3) in response to cytosolic DNA and cyclic dinucleotides in keratinocytes and other human cells. Furthermore, we find that modulation of this innate immune response also occurs with UV-mimetic chemical carcinogens and in a manner that is independent of DNA repair and several DNA damage and cell stress response signaling pathways. Rather, we find that the stimulation of STING-dependent IRF3 activation by UV is due to apoptotic signaling-dependent disruption of ULK1 (Unc51-like kinase 1), a pro-autophagic protein that negatively regulates STING. Thus, deregulation of ULK1 signaling by UV-induced DNA damage may contribute to the negative effects of sunlight UV exposure in patients with autoimmune disorders. PMID:25792739

The transcription factor Cabut coordinates energy metabolism and the circadian clock in response to sugar sensing

PubMed Central

Bartok, Osnat; Teesalu, Mari; Ashwall-Fluss, Reut; Pandey, Varun; Hanan, Mor; Rovenko, Bohdana M; Poukkula, Minna; Havula, Essi; Moussaieff, Arieh; Vodala, Sadanand; Nahmias, Yaakov; Kadener, Sebastian; Hietakangas, Ville

2015-01-01

Nutrient sensing pathways adjust metabolism and physiological functions in response to food intake. For example, sugar feeding promotes lipogenesis by activating glycolytic and lipogenic genes through the Mondo/ChREBP-Mlx transcription factor complex. Concomitantly, other metabolic routes are inhibited, but the mechanisms of transcriptional repression upon sugar sensing have remained elusive. Here, we characterize cabut (cbt), a transcription factor responsible for the repressive branch of the sugar sensing transcriptional network in Drosophila. We demonstrate that cbt is rapidly induced upon sugar feeding through direct regulation by Mondo-Mlx. We found that CBT represses several metabolic targets in response to sugar feeding, including both isoforms of phosphoenolpyruvate carboxykinase (pepck). Deregulation of pepck1 (CG17725) in mlx mutants underlies imbalance of glycerol and glucose metabolism as well as developmental lethality. Furthermore, we demonstrate that cbt provides a regulatory link between nutrient sensing and the circadian clock. Specifically, we show that a subset of genes regulated by the circadian clock are also targets of CBT. Moreover, perturbation of CBT levels leads to deregulation of the circadian transcriptome and circadian behavioral patterns. PMID:25916830

Complement activation by ligand-driven juxtaposition of discrete pattern recognition complexes

PubMed Central

Degn, Søren E.; Kjaer, Troels R.; Kidmose, Rune T.; Jensen, Lisbeth; Hansen, Annette G.; Tekin, Mustafa; Jensenius, Jens C.; Andersen, Gregers R.; Thiel, Steffen

2014-01-01

Defining mechanisms governing translation of molecular binding events into immune activation is central to understanding immune function. In the lectin pathway of complement, the pattern recognition molecules (PRMs) mannan-binding lectin (MBL) and ficolins complexed with the MBL-associated serine proteases (MASP)-1 and MASP-2 cleave C4 and C2 to generate C3 convertase. MASP-1 was recently found to be the exclusive activator of MASP-2 under physiological conditions, yet the predominant oligomeric forms of MBL carry only a single MASP homodimer. This prompted us to investigate whether activation of MASP-2 by MASP-1 occurs through PRM-driven juxtaposition on ligand surfaces. We demonstrate that intercomplex activation occurs between discrete PRM/MASP complexes. PRM ligand binding does not directly escort the transition of MASP from zymogen to active enzyme in the PRM/MASP complex; rather, clustering of PRM/MASP complexes directly causes activation. Our results support a clustering-based mechanism of activation, fundamentally different from the conformational model suggested for the classical pathway of complement. PMID:25197071

Novel roles of complement in renal diseases and their therapeutic consequences.

PubMed

Wada, Takehiko; Nangaku, Masaomi

2013-09-01

The complement system functions as a part of the innate immune system. Inappropriate activation of the complement pathways has a deleterious effect on kidneys. Recent advances in complement research have provided new insights into the pathogenesis of glomerular and tubulointerstitial injury associated with complement activation. A new disease entity termed 'C3 glomerulopathy' has recently been proposed and is characterized by isolated C3 deposition in glomeruli without positive staining for immunoglobulins. Genetic and functional studies have demonstrated that several different mutations and disease variants, as well as the generation of autoantibodies, are potentially associated with its pathogenesis. The data from comprehensive analyses suggest that complement dysregulation can also be associated with hemolytic uremic syndrome and more common glomerular diseases, such as IgA nephropathy and diabetic kidney disease. In addition, animal studies utilizing genetically modified mice have begun to elucidate the molecular pathomechanisms associated with the complement system. From a diagnostic point of view, a noninvasive, MRI-based method for detecting C3 has recently been developed to serve as a novel tool for diagnosing complement-mediated kidney diseases. While novel therapeutic tools related to complement regulation are emerging, studies evaluating the precise roles of the complement system in kidney diseases will still be useful for developing new therapeutic approaches.

Everolimus.

PubMed

Hasskarl, Jens

2014-01-01

Everolimus (RAD001, Afinitor®) is an oral protein kinase inhibitor of the mammalian target of rapamycin (mTOR) serine/threonine kinase signal transduction pathway. The mTOR pathway regulates cell growth, proliferation, and survival and is frequently deregulated in cancer. Everolimus has been approved by the FDA and the EMA for the treatment of advanced renal cell carcinoma (RCC), subependymal giant cell astrocytoma (SEGA) associated with tuberous sclerosis (TSC), pancreatic neuroendocrine tumors (PNET), in combination with exemestane in advanced hormone-receptor (HR)-positive, HER2-negative breast cancer. Everolimus shows promising clinical activity in additional indications. Multiple phase 2 and phase 3 trials of everolimus alone or in combination are ongoing and will help to further elucidate the role of mTOR in oncology. For a review on everolimus as immunosuppressant, please consult other sources.

Mechanisms of DNA damage, repair and mutagenesis

PubMed Central

Chatterjee, Nimrat; Walker, Graham C.

2017-01-01

Living organisms are continuously exposed to a myriad of DNA damaging agents that can impact health and modulate disease-states. However, robust DNA repair and damage-bypass mechanisms faithfully protect the DNA by either removing or tolerating the damage to ensure an overall survival. Deviations in this fine-tuning are known to destabilize cellular metabolic homeostasis, as exemplified in diverse cancers where disruption or deregulation of DNA repair pathways results in genome instability. Because routinely used biological, physical and chemical agents impact human health, testing their genotoxicity and regulating their use have become important. In this introductory review, we will delineate mechanisms of DNA damage and the counteracting repair/tolerance pathways to provide insights into the molecular basis of genotoxicity in cells that lays the foundation for subsequent articles in this issue. PMID:28485537

Mechanisms to Control Rereplication and Implications for Cancer

PubMed Central

Hook, Sara S.; Lin, Jie Jessie; Dutta, Anindya

2007-01-01

Recent advances in the replication field have highlighted how the replication initiator proteins are negatively regulated by inhibitor proteins and ubiquitin-mediated degradation in mammalian cells to prevent rereplication. When these regulatory pathways go awry, uncontrolled rereplication ensues and a G2/M checkpoint is evoked to prevent cellular death. Many components of the checkpoints activated by rereplicaton are important for cancer prevention by facilitating DNA damage repair processes. The pathways that prevent rereplication themselves have also recently been implicated in preventing tumorigenesis. Studies from patient tumors, genetically altered mice, and mammalian cell culture suggest that deregulation of replication licensing proteins results in an increase in aneuploidy, chromosomal fusions, and DNA breaks. These studies provide a framework to address how regulators of replication function to maintain genomic stability. PMID:18053699

Molecular mechanisms of the mammalian Hippo signaling pathway.

PubMed

Ji, Xin-yan; Zhong, Guoxuan; Zhao, Bin

2017-07-20

The Hippo pathway plays an evolutionarily conserved fundamental role in controlling organ size in multicellular organisms. Importantly, evidence from studies of patient samples and mouse models clearly indicates that deregulation of the Hippo signaling pathway plays a crucial role in the initiation and progression of many different types of human cancers. The Hippo signaling pathway is regulated by various stimuli, such as mechanical stress, G-protein coupled receptor signaling, and cellular energy status. When activated, the Hippo kinase cascade phosphorylates and inhibits the transcription co-activator YAP (Yes-associated protein), and its paralog TAZ (transcriptional coactivator with PDZ-binding motif), resulting in their cytoplasmic retention and degradation. When the Hippo signaling pathway is inactive, dephosphorylated YAP/TAZ translocate into the nucleus and activate gene transcription through binding to TEAD (TEA domain) family and other transcription factors. Such changes in gene expression promote cell proliferation and stem cell/progenitor cell self-renewal but inhibit apoptosis, thereby coordinately promote increase in organ size, tissue regeneration, and tumorigenesis. In this review, we summarize the molecular mechanisms of the mammalian Hippo signaling pathway with special emphasis on the Hippo kinase cascade and its upstream signals, the Hippo signaling pathway regulation of YAP and the mechanisms of YAP in regulation of gene transcription.

Potential of apoptotic pathway-targeted cancer therapeutic research: Where do we stand?

PubMed Central

Baig, S; Seevasant, I; Mohamad, J; Mukheem, A; Huri, H Z; Kamarul, T

2016-01-01

Underneath the intricacy of every cancer lies mysterious events that impel the tumour cell and its posterity into abnormal growth and tissue invasion. Oncogenic mutations disturb the regulatory circuits responsible for the governance of versatile cellular functions, permitting tumour cells to endure deregulated proliferation, resist to proapoptotic insults, invade and erode normal tissues and above all escape apoptosis. This disruption of apoptosis has been highly implicated in various malignancies and has been exploited as an anticancer strategy. Owing to the fact that apoptosis causes minimal inflammation and damage to the tissue, apoptotic cell death-based therapy has been the centre of attraction for the development of anticancer drugs. Increased understanding of the molecular pathways underlying apoptosis has enabled scientists to establish unique approaches targeting apoptosis pathways in cancer therapeutics. In this review, we reconnoitre the two major pathways (intrinsic and extrinsic) targeted cancer therapeutics, steering toward chief modulators of these pathways, such as B-cell lymphoma 2 protein family members (pro- and antiapoptotic), inhibitor of apoptosis proteins, and the foremost thespian of extrinsic pathway regulator, tumour necrosis factor-related apoptosis-inducing agent. Together, we also will have a look from clinical perspective to address the agents (drugs) and therapeutic strategies adopted to target these specific proteins/pathways that have entered clinical trials. PMID:26775709

IgG Fc domains that bind C1q but not effector Fcγ receptors delineate the importance of complement-mediated effector functions.

PubMed

Lee, Chang-Han; Romain, Gabrielle; Yan, Wupeng; Watanabe, Makiko; Charab, Wissam; Todorova, Biliana; Lee, Jiwon; Triplett, Kendra; Donkor, Moses; Lungu, Oana I; Lux, Anja; Marshall, Nicholas; Lindorfer, Margaret A; Goff, Odile Richard-Le; Balbino, Bianca; Kang, Tae Hyun; Tanno, Hidetaka; Delidakis, George; Alford, Corrine; Taylor, Ronald P; Nimmerjahn, Falk; Varadarajan, Navin; Bruhns, Pierre; Zhang, Yan Jessie; Georgiou, George

2017-08-01

Engineered crystallizable fragment (Fc) regions of antibody domains, which assume a unique and unprecedented asymmetric structure within the homodimeric Fc polypeptide, enable completely selective binding to the complement component C1q and activation of complement via the classical pathway without any concomitant engagement of the Fcγ receptor (FcγR). We used the engineered Fc domains to demonstrate in vitro and in mouse models that for therapeutic antibodies, complement-dependent cell-mediated cytotoxicity (CDCC) and complement-dependent cell-mediated phagocytosis (CDCP) by immunological effector molecules mediated the clearance of target cells with kinetics and efficacy comparable to those of the FcγR-dependent effector functions that are much better studied, while they circumvented certain adverse reactions associated with FcγR engagement. Collectively, our data highlight the importance of CDCC and CDCP in monoclonal-antibody function and provide an experimental approach for delineating the effect of complement-dependent effector-cell engagement in various therapeutic settings.

Human antibodies fix complement to inhibit Plasmodium falciparum invasion of erythrocytes and are associated with protection against malaria.

PubMed

Boyle, Michelle J; Reiling, Linda; Feng, Gaoqian; Langer, Christine; Osier, Faith H; Aspeling-Jones, Harvey; Cheng, Yik Sheng; Stubbs, Janine; Tetteh, Kevin K A; Conway, David J; McCarthy, James S; Muller, Ivo; Marsh, Kevin; Anders, Robin F; Beeson, James G

2015-03-17

Antibodies play major roles in immunity to malaria; however, a limited understanding of mechanisms mediating protection is a major barrier to vaccine development. We have demonstrated that acquired human anti-malarial antibodies promote complement deposition on the merozoite to mediate inhibition of erythrocyte invasion through C1q fixation and activation of the classical complement pathway. Antibody-mediated complement-dependent (Ab-C') inhibition was the predominant invasion-inhibitory activity of human antibodies; most antibodies were non-inhibitory without complement. Inhibitory activity was mediated predominately via C1q fixation, and merozoite surface proteins 1 and 2 were identified as major targets. Complement fixation by antibodies was very strongly associated with protection from both clinical malaria and high-density parasitemia in a prospective longitudinal study of children. Ab-C' inhibitory activity could be induced by human immunization with a candidate merozoite surface-protein vaccine. Our findings demonstrate that human anti-malarial antibodies have evolved to function by fixing complement for potent invasion-inhibitory activity and protective immunity. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Combined roles of human IgG subclass, alternative complement pathway activation, and epitope density in the bactericidal activity of antibodies to meningococcal factor h binding protein.

PubMed

Giuntini, Serena; Reason, Donald C; Granoff, Dan M

2012-01-01

Meningococcal vaccines containing factor H binding protein (fHbp) are in clinical development. fHbp binds human fH, which enables the meningococcus to resist complement-mediated bacteriolysis. Previously, we found that chimeric human IgG1 mouse anti-fHbp monoclonal antibodies (MAbs) had human complement-mediated bactericidal activity only if the MAb inhibited fH binding. Since IgG subclasses differ in their ability to activate complement, we investigated the role of human IgG subclasses on antibody functional activity. We constructed chimeric MAbs in which three different murine fHbp-specific binding domains were each paired with human IgG1, IgG2, or IgG3. Against a wild-type group B isolate, all three IgG3 MAbs, irrespective of their ability to inhibit fH binding, had bactericidal activity that was >5-fold higher than the respective IgG1 MAbs, while the IgG2 MAbs had the least activity. Against a mutant with increased fHbp expression, the anti-fHbp MAbs elicited greater C4b deposition (classical pathway) and greater bactericidal activity than against the wild-type strain, and the IgG1 MAbs had similar or greater activity than the respective IgG3 MAbs. The bactericidal activity against both wild-type and mutant strains also was dependent, in part, on activation of the alternative complement pathway. Thus, at lower epitope density in the wild-type strain, the IgG3 anti-fHbp MAbs had the greatest bactericidal activity. At a higher epitope density in the mutant, the IgG1 MAbs had similar or greater bactericidal activity than the IgG3 MAbs, and the activity was less dependent on the inhibition of fH binding than at a lower epitope density.

Epigenetic polypharmacology: from combination therapy to multitargeted drugs.

PubMed

de Lera, Angel R; Ganesan, A

The modern drug discovery process has largely focused its attention in the so-called magic bullets, single chemical entities that exhibit high selectivity and potency for a particular target. This approach was based on the assumption that the deregulation of a protein was causally linked to a disease state, and the pharmacological intervention through inhibition of the deregulated target was able to restore normal cell function. However, the use of cocktails or multicomponent drugs to address several targets simultaneously is also popular to treat multifactorial diseases such as cancer and neurological disorders. We review the state of the art with such combinations that have an epigenetic target as one of their mechanisms of action. Epigenetic drug discovery is a rapidly advancing field, and drugs targeting epigenetic enzymes are in the clinic for the treatment of hematological cancers. Approved and experimental epigenetic drugs are undergoing clinical trials in combination with other therapeutic agents via fused or linked pharmacophores in order to benefit from synergistic effects of polypharmacology. In addition, ligands are being discovered which, as single chemical entities, are able to modulate multiple epigenetic targets simultaneously (multitarget epigenetic drugs). These multiple ligands should in principle have a lower risk of drug-drug interactions and drug resistance compared to cocktails or multicomponent drugs. This new generation may rival the so-called magic bullets in the treatment of diseases that arise as a consequence of the deregulation of multiple signaling pathways provided the challenge of optimization of the activities shown by the pharmacophores with the different targets is addressed.

Aberrantly Expressed OTX Homeobox Genes Deregulate B-Cell Differentiation in Hodgkin Lymphoma.

PubMed

Nagel, Stefan; Ehrentraut, Stefan; Meyer, Corinna; Kaufmann, Maren; Drexler, Hans G; MacLeod, Roderick A F

2015-01-01

In Hodgkin lymphoma (HL) we recently reported that deregulated homeobox gene MSX1 mediates repression of the B-cell specific transcription factor ZHX2. In this study we investigated regulation of MSX1 in this B-cell malignancy. Accordingly, we analyzed expression and function of OTX homeobox genes which activate MSX1 transcription during embryonal development in the neural plate border region. Our data demonstrate that OTX1 and OTX2 are aberrantly expressed in both HL patients and cell lines. Moreover, both OTX loci are targeted by genomic gains in overexpressing cell lines. Comparative expression profiling and subsequent pathway modulations in HL cell lines indicated that aberrantly enhanced FGF2-signalling activates the expression of OTX2. Downstream analyses of OTX2 demonstrated transcriptional activation of genes encoding transcription factors MSX1, FOXC1 and ZHX1. Interestingly, examination of the physiological expression profile of ZHX1 in normal hematopoietic cells revealed elevated levels in T-cells and reduced expression in B-cells, indicating a discriminatory role in lymphopoiesis. Furthermore, two OTX-negative HL cell lines overexpressed ZHX1 in correlation with genomic amplification of its locus at chromosomal band 8q24, supporting the oncogenic potential of this gene in HL. Taken together, our data demonstrate that deregulated homeobox genes MSX1 and OTX2 respectively impact transcriptional inhibition of (B-cell specific) ZHX2 and activation of (T-cell specific) ZHX1. Thus, we show how reactivation of a specific embryonal gene regulatory network promotes disturbed B-cell differentiation in HL.

Cyclic 3',5'-adenosine monophosphate (cAMP) signaling in the anterior pituitary gland in health and disease.

PubMed

Hernández-Ramírez, Laura C; Trivellin, Giampaolo; Stratakis, Constantine A

2018-03-05

The cyclic 3',5'-adenosine monophosphate (cAMP) was the first among the so-called "second messengers" to be described. It is conserved in most organisms and functions as a signal transducer by mediating the intracellular effects of multiple hormones and neurotransmitters. In this review, we first delineate how different members of the cAMP pathway ensure its correct compartmentalization and activity, mediate the terminal intracellular effects, and allow the crosstalk with other signaling pathways. We then focus on the pituitary gland, where cAMP exerts a crucial function by controlling the responsiveness of the cells to hypothalamic hormones, neurotransmitters and peripheral factors. We discuss the most relevant physiological functions mediated by cAMP in the different pituitary cell types, and summarize the defects affecting this pathway that have been reported in the literature. We finally discuss how a deregulated cAMP pathway is involved in the pathogenesis of pituitary disorders and how it affects the response to therapy. Copyright © 2017. Published by Elsevier B.V.

The Endoplasmic Reticulum Stress Response in Neuroprogressive Diseases: Emerging Pathophysiological Role and Translational Implications.

PubMed

Morris, Gerwyn; Puri, Basant K; Walder, Ken; Berk, Michael; Stubbs, Brendon; Maes, Michael; Carvalho, André F

2018-03-29

The endoplasmic reticulum (ER) is the main cellular organelle involved in protein synthesis, assembly and secretion. Accumulating evidence shows that across several neurodegenerative and neuroprogressive diseases, ER stress ensues, which is accompanied by over-activation of the unfolded protein response (UPR). Although the UPR could initially serve adaptive purposes in conditions associated with higher cellular demands and after exposure to a range of pathophysiological insults, over time the UPR may become detrimental, thus contributing to neuroprogression. Herein, we propose that immune-inflammatory, neuro-oxidative, neuro-nitrosative, as well as mitochondrial pathways may reciprocally interact with aberrations in UPR pathways. Furthermore, ER stress may contribute to a deregulation in calcium homoeostasis. The common denominator of these pathways is a decrease in neuronal resilience, synaptic dysfunction and even cell death. This review also discusses how mechanisms related to ER stress could be explored as a source for novel therapeutic targets for neurodegenerative and neuroprogressive diseases. The design of randomised controlled trials testing compounds that target aberrant UPR-related pathways within the emerging framework of precision psychiatry is warranted.

Aging: Molecular Pathways and Implications on the Cardiovascular System.

PubMed

de Almeida, Arthur José Pontes Oliveira; Ribeiro, Thaís Porto; de Medeiros, Isac Almeida

2017-01-01

The world's population over 60 years is growing rapidly, reaching 22% of the global population in the next decades. Despite the increase in global longevity, individual healthspan needs to follow this growth. Several diseases have their prevalence increased by age, such as cardiovascular diseases, the leading cause of morbidity and mortality worldwide. Understanding the aging biology mechanisms is fundamental to the pursuit of cardiovascular health. In this way, aging is characterized by a gradual decline in physiological functions, involving the increased number in senescent cells into the body. Several pathways lead to senescence, including oxidative stress and persistent inflammation, as well as energy failure such as mitochondrial dysfunction and deregulated autophagy, being ROS, AMPK, SIRTs, mTOR, IGF-1, and p53 key regulators of the metabolic control, connecting aging to the pathways which drive towards diseases. In addition, senescence can be induced by cellular replication, which resulted from telomere shortening. Taken together, it is possible to draw a common pathway unifying aging to cardiovascular diseases, and the central point of this process, senescence, can be the target for new therapies, which may result in the healthspan matching the lifespan.

Complement pathway biomarkers and age-related macular degeneration

PubMed Central

Gemenetzi, M; Lotery, A J

2016-01-01

In the age-related macular degeneration (AMD) ‘inflammation model', local inflammation plus complement activation contributes to the pathogenesis and progression of the disease. Multiple genetic associations have now been established correlating the risk of development or progression of AMD. Stratifying patients by their AMD genetic profile may facilitate future AMD therapeutic trials resulting in meaningful clinical trial end points with smaller sample sizes and study duration. PMID:26493033

The Microbiome and Complement Activation: A Mechanistic Model for Preterm Birth

PubMed Central

Dunn, Alexis B.; Dunlop, Anne L.; Hogue, Carol J.; Miller, Andrew; Corwin, Elizabeth J.

2018-01-01

Preterm Birth (PTB, < 37 completed weeks' gestation) is one of the leading obstetrical problems in the United States affecting approximately 1 of every 9 births. Even more concerning are the persistent racial disparities in PTB with particularly high rates in African Americans. There are several recognized pathophysiologic pathways to PTB, including infection and/or exaggerated systemic or local inflammation. Intrauterine infection is a causal factor linked to PTB, thought to result most commonly from inflammatory processes triggered by microbial invasion of bacteria ascending from the vaginal microbiome. Trials to treat various infections have shown limited efficacy in reducing PTB risk, suggesting that other complex mechanisms, including those associated with inflammation, may be involved in the relationship between microbes, infection, and PTB. A key mediator of the inflammatory response, and recently shown to be associated with PTB, is the complement system, an innate defense mechanism involved in both normal physiologic processes that occur during pregnancy implantation, as well as processes that promote the elimination of pathogenic microbes. The purpose of this paper is to present a mechanistic model of inflammation-associated PTB, which hypothesizes a relationship between the microbiome and dysregulation of the complement system. Exploring the relationships between the microbial environment and complement biomarkers may elucidate a potentially modifiable biological pathway to preterm birth. PMID:28073296

Internet-based wide area measurement applications in deregulated power systems

NASA Astrophysics Data System (ADS)

Khatib, Abdel-Rahman Amin

Since the deregulation of power systems was started in 1989 in the UK, many countries have been motivated to undergo deregulation. The United State started deregulation in the energy sector in California back in 1996. Since that time many other states have also started the deregulation procedures in different utilities. Most of the deregulation market in the United States now is in the wholesale market area, however, the retail market is still undergoing changes. Deregulation has many impacts on power system network operation and control. The number of power transactions among the utilities has increased and many Independent Power Producers (IPPs) now have a rich market for competition especially in the green power market. The Federal Energy Regulatory Commission (FERC) called upon utilities to develop the Regional Transmission Organization (RTO). The RTO is a step toward the national transmission grid. RTO is an independent entity that will operate the transmission system in a large region. The main goal of forming RTOs is to increase the operation efficiency of the power network under the impact of the deregulated market. The objective of this work is to study Internet based Wide Area Information Sharing (WAIS) applications in the deregulated power system. The study is the first step toward building a national transmission grid picture using information sharing among utilities. Two main topics are covered as applications for the WAIS in the deregulated power system, state estimation and Total Transfer Capability (TTC) calculations. As a first step for building this national transmission grid picture, WAIS and the level of information sharing of the state estimation calculations have been discussed. WAIS impacts to the TTC calculations are also covered. A new technique to update the TTC using on line measurements based on WAIS created by sharing state estimation is presented.

Expression Profile of Long Noncoding RNAs in Human Earlobe Keloids: A Microarray Analysis

PubMed Central

Guo, Liang; Xu, Kai; Yan, Hongbo; Feng, Haifeng

2016-01-01

Background. Long noncoding RNAs (lncRNAs) play key roles in a wide range of biological processes and their deregulation results in human disease, including keloids. Earlobe keloid is a type of pathological skin scar, and the molecular pathogenesis of this disease remains largely unknown. Methods. In this study, microarray analysis was used to determine the expression profiles of lncRNAs and mRNAs between 3 pairs of earlobe keloid and normal specimens. Gene Ontology (GO) categories and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed to identify the main functions of the differentially expressed genes and earlobe keloid-related pathways. Results. A total of 2068 lncRNAs and 1511 mRNAs were differentially expressed between earlobe keloid and normal tissues. Among them, 1290 lncRNAs and 1092 mRNAs were upregulated, and 778 lncRNAs and 419 mRNAs were downregulated. Pathway analysis revealed that 24 pathways were correlated to the upregulated transcripts, while 11 pathways were associated with the downregulated transcripts. Conclusion. We characterized the expression profiles of lncRNA and mRNA in earlobe keloids and suggest that lncRNAs may serve as diagnostic biomarkers for the therapy of earlobe keloid. PMID:28101509

Protective effect of quercetin on high-fat diet-induced non-alcoholic fatty liver disease in mice is mediated by modulating intestinal microbiota imbalance and related gut-liver axis activation.

PubMed

Porras, David; Nistal, Esther; Martínez-Flórez, Susana; Pisonero-Vaquero, Sandra; Olcoz, José Luis; Jover, Ramiro; González-Gallego, Javier; García-Mediavilla, María Victoria; Sánchez-Campos, Sonia

2017-01-01

Gut microbiota is involved in obesity, metabolic syndrome and the progression of nonalcoholic fatty liver disease (NAFLD). It has been recently suggested that the flavonoid quercetin may have the ability to modulate the intestinal microbiota composition, suggesting a prebiotic capacity which highlights a great therapeutic potential in NAFLD. The present study aims to investigate benefits of experimental treatment with quercetin on gut microbial balance and related gut-liver axis activation in a nutritional animal model of NAFLD associated to obesity. C57BL/6J mice were challenged with high fat diet (HFD) supplemented or not with quercetin for 16 weeks. HFD induced obesity, metabolic syndrome and the development of hepatic steatosis as main hepatic histological finding. Increased accumulation of intrahepatic lipids was associated with altered gene expression related to lipid metabolism, as a result of deregulation of their major modulators. Quercetin supplementation decreased insulin resistance and NAFLD activity score, by reducing the intrahepatic lipid accumulation through its ability to modulate lipid metabolism gene expression, cytochrome P450 2E1 (CYP2E1)-dependent lipoperoxidation and related lipotoxicity. Microbiota composition was determined via 16S ribosomal RNA Illumina next-generation sequencing. Metagenomic studies revealed HFD-dependent differences at phylum, class and genus levels leading to dysbiosis, characterized by an increase in Firmicutes/Bacteroidetes ratio and in Gram-negative bacteria, and a dramatically increased detection of Helicobacter genus. Dysbiosis was accompanied by endotoxemia, intestinal barrier dysfunction and gut-liver axis alteration and subsequent inflammatory gene overexpression. Dysbiosis-mediated toll-like receptor 4 (TLR-4)-NF-κB signaling pathway activation was associated with inflammasome initiation response and reticulum stress pathway induction. Quercetin reverted gut microbiota imbalance and related endotoxemia-mediated TLR-4 pathway induction, with subsequent inhibition of inflammasome response and reticulum stress pathway activation, leading to the blockage of lipid metabolism gene expression deregulation. Our results support the suitability of quercetin as a therapeutic approach for obesity-associated NAFLD via its anti-inflammatory, antioxidant and prebiotic integrative response. Copyright © 2016 Elsevier Inc. All rights reserved.

Mitochondrial Dysfunction, Through Impaired Autophagy, Leads to Endoplasmic Reticulum Stress, Deregulated Lipid Metabolism, and Pancreatitis in Animal Models.

PubMed

Biczo, Gyorgy; Vegh, Eszter T; Shalbueva, Natalia; Mareninova, Olga A; Elperin, Jason; Lotshaw, Ethan; Gretler, Sophie; Lugea, Aurelia; Malla, Sudarshan R; Dawson, David; Ruchala, Piotr; Whitelegge, Julian; French, Samuel W; Wen, Li; Husain, Sohail Z; Gorelick, Fred S; Hegyi, Peter; Rakonczay, Zoltan; Gukovsky, Ilya; Gukovskaya, Anna S

2018-02-01

Little is known about the signaling pathways that initiate and promote acute pancreatitis (AP). The pathogenesis of AP has been associated with abnormal increases in cytosolic Ca 2+ , mitochondrial dysfunction, impaired autophagy, and endoplasmic reticulum (ER) stress. We analyzed the mechanisms of these dysfunctions and their relationships, and how these contribute to development of AP in mice and rats. Pancreatitis was induced in C57BL/6J mice (control) and mice deficient in peptidylprolyl isomerase D (cyclophilin D, encoded by Ppid) by administration of L-arginine (also in rats), caerulein, bile acid, or an AP-inducing diet. Parameters of pancreatitis, mitochondrial function, autophagy, ER stress, and lipid metabolism were measured in pancreatic tissue, acinar cells, and isolated mitochondria. Some mice with AP were given trehalose to enhance autophagic efficiency. Human pancreatitis tissues were analyzed by immunofluorescence. Mitochondrial dysfunction in pancreas of mice with AP was induced by either mitochondrial Ca 2+ overload or through a Ca 2+ overload-independent pathway that involved reduced activity of ATP synthase (80% inhibition in pancreatic mitochondria isolated from rats or mice given L-arginine). Both pathways were mediated by cyclophilin D and led to mitochondrial depolarization and fragmentation. Mitochondrial dysfunction caused pancreatic ER stress, impaired autophagy, and deregulation of lipid metabolism. These pathologic responses were abrogated in cyclophilin D-knockout mice. Administration of trehalose largely prevented trypsinogen activation, necrosis, and other parameters of pancreatic injury in mice with L-arginine AP. Tissues from patients with pancreatitis had markers of mitochondrial damage and impaired autophagy, compared with normal pancreas. In different animal models, we find a central role for mitochondrial dysfunction, and for impaired autophagy as its principal downstream effector, in development of AP. In particular, the pathway involving enhanced interaction of cyclophilin D with ATP synthase mediates L-arginine-induced pancreatitis, a model of severe AP the pathogenesis of which has remained unknown. Strategies to restore mitochondrial and/or autophagic function might be developed for treatment of AP. Copyright © 2018 AGA Institute. Published by Elsevier Inc. All rights reserved.

Hormonal therapy deregulates prostaglandin-endoperoxidase synthase 2 (PTGS2) expression in endometriotic tissues.

PubMed

Santulli, Pietro; Borghese, Bruno; Noël, Jean-Christophe; Fayt, Isabelle; Anaf, Vincent; de Ziegler, Dominique; Batteux, Frederic; Vaiman, Daniel; Chapron, Charles

2014-03-01

Endometriosis is a common gynecologic condition characterized by an important inflammatory process mediated by the prostaglandin pathway. Oral contraceptives are the treatment of choice for symptomatic endometriotic women. However the effects of oral contraceptives use and prostaglandin pathway in endometriotic women are actually still unknown. To investigate the expression of prostaglandin pathway key genes in endometriotic tissue, affected or not by hormonal therapy, as compared with healthy endometrial tissue. This was a comparative laboratory study. This study was conducted in a tertiary-care university hospital. Seventy-six women, with (n = 46) and without (n = 30) histologically proven endometriosis. Prostaglandin-endoperoxidase synthase (PTGS)1, PTGS2, prostaglandin E receptor (PTGER)1, PTGER2, PTGER3, and PTGER4 mRNA levels in endometrium of disease-free women and in eutopic and ectopic endometrium of endometriosis-affected women. PTGS2 expression was further investigated by immunohistochemistry, using specific monoclonal antibodies. PTGS2 expression was analyzed at mRNA and protein levels and correlated with taking hormonal treatment. PTGS2 expression was significantly increased in eutopic and ectopic endometrium as compared with healthy tissue (induction of 9.6- and 6.3-fold, respectively; P = .001). PTGS2 immunoreactivity increased gradually from normal endometrium to eutopic and ectopic endometrium (h-score of 96.7 ± 55.0, 128.3 ± 66.1, and 226.7 ± 62.6, respectively, P < .001). PTGER2, PTGER3, and PTGER4 expression increased significantly and gradually from normal to eutopic and ectopic endometrium, whereas PTGER1 remained unchanged. Patients under hormonal treatment had a higher PTGS2 expression at transcriptional and protein levels as compared with those without treatment (P = .002 and P = .025, respectively). Prostaglandin pathway is strongly deregulated in eutopic and ectopic endometrium of women suffering from endometriosis for the benefit of an increased PTGS2 expression. We show for the first time that hormonal treatment appears to enhance even more PTGS2 expression. These results contribute to explain why medical treatment could fail to control endometriosis progression.

In-vivo detection of binary PKA network interactions upon activation of endogenous GPCRs

PubMed Central

Röck, Ruth; Bachmann, Verena; Bhang, Hyo-eun C; Malleshaiah, Mohan; Raffeiner, Philipp; Mayrhofer, Johanna E; Tschaikner, Philipp M; Bister, Klaus; Aanstad, Pia; Pomper, Martin G; Michnick, Stephen W; Stefan, Eduard

2015-01-01

Membrane receptor-sensed input signals affect and modulate intracellular protein-protein interactions (PPIs). Consequent changes occur to the compositions of protein complexes, protein localization and intermolecular binding affinities. Alterations of compartmentalized PPIs emanating from certain deregulated kinases are implicated in the manifestation of diseases such as cancer. Here we describe the application of a genetically encoded Protein-fragment Complementation Assay (PCA) based on the Renilla Luciferase (Rluc) enzyme to compare binary PPIs of the spatially and temporally controlled protein kinase A (PKA) network in diverse eukaryotic model systems. The simplicity and sensitivity of this cell-based reporter allows for real-time recordings of mutually exclusive PPIs of PKA upon activation of selected endogenous G protein-coupled receptors (GPCRs) in cancer cells, xenografts of mice, budding yeast, and zebrafish embryos. This extends the application spectrum of Rluc PCA for the quantification of PPI-based receptor-effector relationships in physiological and pathological model systems. PMID:26099953

The Murine Factor H-Related Protein FHR-B Promotes Complement Activation.

PubMed

Cserhalmi, Marcell; Csincsi, Ádám I; Mezei, Zoltán; Kopp, Anne; Hebecker, Mario; Uzonyi, Barbara; Józsi, Mihály

2017-01-01

Factor H-related (FHR) proteins consist of varying number of complement control protein domains that display various degrees of sequence identity to respective domains of the alternative pathway complement inhibitor factor H (FH). While such FHR proteins are described in several species, only human FHRs were functionally investigated. Their biological role is still poorly understood and in part controversial. Recent studies on some of the human FHRs strongly suggest a role for FHRs in enhancing complement activation via competing with FH for binding to certain ligands and surfaces. The aim of the current study was the functional characterization of a murine FHR, FHR-B. To this end, FHR-B was expressed in recombinant form. Recombinant FHR-B bound to human C3b and was able to compete with human FH for C3b binding. FHR-B supported the assembly of functionally active C3bBb alternative pathway C3 convertase via its interaction with C3b. This activity was confirmed by demonstrating C3 activation in murine serum. In addition, FHR-B bound to murine pentraxin 3 (PTX3), and this interaction resulted in murine C3 fragment deposition due to enhanced complement activation in mouse serum. FHR-B also induced C3 deposition on C-reactive protein, the extracellular matrix (ECM) extract Matrigel, and endothelial cell-derived ECM when exposed to mouse serum. Moreover, mouse C3 deposition was strongly enhanced on necrotic Jurkat T cells and the mouse B cell line A20 by FHR-B. FHR-B also induced lysis of sheep erythrocytes when incubated in mouse serum with FHR-B added in excess. Altogether, these data demonstrate that, similar to human FHR-1 and FHR-5, mouse FHR-B modulates complement activity by promoting complement activation via interaction with C3b and via competition with murine FH.

Scabies Mite Peritrophins Are Potential Targets of Human Host Innate Immunity

PubMed Central

Holt, Deborah C.; Kemp, Dave J.; Fischer, Katja

2011-01-01

Background Pruritic scabies lesions caused by Sarcoptes scabiei burrowing in the stratum corneum of human skin facilitate opportunistic bacterial infections. Emerging resistance to current therapeutics emphasizes the need to identify novel targets for protective intervention. We have characterized several protein families located in the mite gut as crucial factors for host-parasite interactions. Among these multiple proteins inhibit human complement, presumably to avoid complement-mediated damage of gut epithelial cells. Peritrophins are major components of the peritrophic matrix often found in the gut of arthropods. We hypothesized that a peritrophin, if abundant in the scabies mite gut, could be an activator of complement. Methodology/Principal Findings A novel full length scabies mite peritrophin (SsPTP1) was identified in a cDNA library from scabies mites. The amino acid sequence revealed four putative chitin binding domains (CBD). Recombinant expression of one CBD of the highly repetitive SsPTP1 sequence as TSP-hexaHis-fusion protein resulted in soluble protein, which demonstrated chitin binding activity in affinity chromatography assays. Antibodies against a recombinant SsPTP1 fragment were used to immunohistochemically localize native SsPTP1 in the mite gut and in fecal pellets within the upper epidermis, co-localizing with serum components such as host IgG and complement. Enzymatic deglycosylation confirmed strong N- and O-glycosylation of the native peritrophin. Serum incubation followed by immunoblotting with a monoclonal antibody against mannan binding lectin (MBL), the recognition molecule of the lectin pathway of human complement activation, indicated that MBL may specifically bind to glycosylated SsPTP1. Conclusions/Significance This study adds a new aspect to the accumulating evidence that complement plays a major role in scabies mite biology. It identifies a novel peritrophin localized in the mite gut as a potential target of the lectin pathway of the complement cascade. These initial findings indicate a novel role of scabies mite peritrophins in triggering a host innate immune response within the mite gut. PMID:21980545

[Parasites and cancer: is there a causal link?

PubMed

Cheeseman, Kevin; Certad, Gabriela; Weitzman, Jonathan B

2016-10-01

Over 20 % of cancers have infectious origins, including well-known examples of microbes such as viruses (HPV, EBV) and bacteria (H. pylori). The contribution of intracellular eukaryotic parasites to cancer etiology is largely unexplored. Epidemiological and clinical reports indicate that eukaryotic protozoan, such as intracellular apicomplexan that cause diseases of medical or economic importance, can be linked to various cancers: Theileria and Cryptosporidium induce host cell transformation while Plasmodium was linked epidemiologically to the "African lymphoma belt" over fifty years ago. These intracellular eukaryotic parasites hijack cellular pathways to manipulate the host cell epigenome, cellular machinery, signaling pathways and epigenetic programs and marks, such as methylation and acetylation, for their own benefit. In doing so, they tinker with the same pathways as those deregulated during cancer onset. Here we discuss how epidemiological evidence linking eukaryotic intracellular parasites to cancer onset are further strengthened by recent mechanistic studies in three apicomplexan parasites. © 2016 médecine/sciences – Inserm.

Regulation of endocytosis via the oxygen-sensing pathway.

PubMed

Wang, Yi; Roche, Olga; Yan, Mathew S; Finak, Greg; Evans, Andrew J; Metcalf, Julie L; Hast, Bridgid E; Hanna, Sara C; Wondergem, Bill; Furge, Kyle A; Irwin, Meredith S; Kim, William Y; Teh, Bin T; Grinstein, Sergio; Park, Morag; Marsden, Philip A; Ohh, Michael

2009-03-01

Tumor hypoxia is associated with disease progression, resistance to conventional cancer therapies and poor prognosis. Hypoxia, by largely unknown mechanisms, leads to deregulated accumulation of and signaling via receptor tyrosine kinases (RTKs) that are critical for driving oncogenesis. Here, we show that hypoxia or loss of von Hippel-Lindau protein--the principal negative regulator of hypoxia-inducible factor (HIF)--prolongs the activation of epidermal growth factor receptor that is attributable to lengthened receptor half-life and retention in the endocytic pathway. The deceleration in endocytosis is due to the attenuation of Rab5-mediated early endosome fusion via HIF-dependent downregulation of a critical Rab5 effector, rabaptin-5, at the level of transcription. Primary kidney and breast tumors with strong hypoxic signatures show significantly lower expression of rabaptin-5 RNA and protein. These findings reveal a general role of the oxygen-sensing pathway in endocytosis and support a model in which tumor hypoxia or oncogenic activation of HIF prolongs RTK-mediated signaling by delaying endocytosis-mediated deactivation of receptors.

Existence of Inverted Profile in Chemically Responsive Molecular Pathways in the Zebrafish Liver

PubMed Central

Zhang, Xun; Li, Hu; Ma, Jing; Zhang, Louxin; Li, Baowen; Gong, Zhiyuan

2011-01-01

How a living organism maintains its healthy equilibrium in response to endless exposure of potentially harmful chemicals is an important question in current biology. By transcriptomic analysis of zebrafish livers treated by various chemicals, we defined hubs as molecular pathways that are frequently perturbed by chemicals and have high degree of functional connectivity to other pathways. Our network analysis revealed that these hubs were organized into two groups showing inverted functionality with each other. Intriguingly, the inverted activity profiles in these two groups of hubs were observed to associate only with toxicopathological states but not with physiological changes. Furthermore, these inverted profiles were also present in rat, mouse, and human under certain toxicopathological conditions. Thus, toxicopathological-associated anti-correlated profiles in hubs not only indicate their potential use in diagnosis but also development of systems-based therapeutics to modulate gene expression by chemical approach in order to rewire the deregulated activities of hubs back to normal physiology. PMID:22140468

Mutations in PCYT1A cause spondylometaphyseal dysplasia with cone-rod dystrophy.

PubMed

Yamamoto, Guilherme L; Baratela, Wagner A R; Almeida, Tatiana F; Lazar, Monize; Afonso, Clara L; Oyamada, Maria K; Suzuki, Lisa; Oliveira, Luiz A N; Ramos, Ester S; Kim, Chong A; Passos-Bueno, Maria Rita; Bertola, Débora R

2014-01-02

Spondylometaphyseal dysplasia with cone-rod dystrophy is a rare autosomal-recessive disorder characterized by severe short stature, progressive lower-limb bowing, flattened vertebral bodies, metaphyseal involvement, and visual impairment caused by cone-rod dystrophy. Whole-exome sequencing of four individuals affected by this disorder from two Brazilian families identified two previously unreported homozygous mutations in PCYT1A. This gene encodes the alpha isoform of the phosphate cytidylyltransferase 1 choline enzyme, which is responsible for converting phosphocholine into cytidine diphosphate-choline, a key intermediate step in the phosphatidylcholine biosynthesis pathway. A different enzymatic defect in this pathway has been previously associated with a muscular dystrophy with mitochondrial structural abnormalities that does not have cartilage and/or bone or retinal involvement. Thus, the deregulation of the phosphatidylcholine pathway may play a role in multiple genetic diseases in humans, and further studies are necessary to uncover its precise pathogenic mechanisms and the entirety of its phenotypic spectrum. Copyright © 2014 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Loss of the six3/6 controlling pathways might have resulted in pinhole-eye evolution in Nautilus.

PubMed

Ogura, Atsushi; Yoshida, Masa-aki; Moritaki, Takeya; Okuda, Yuki; Sese, Jun; Shimizu, Kentaro K; Sousounis, Konstantinos; Tsonis, Panagiotis A

2013-01-01

Coleoid cephalopods have an elaborate camera eye whereas nautiloids have primitive pinhole eye without lens and cornea. The Nautilus pinhole eye provides a unique example to explore the module of lens formation and its evolutionary mechanism. Here, we conducted an RNA-seq study of developing eyes of Nautilus and pygmy squid. First, we found that evolutionary distances from the common ancestor to Nautilus or squid are almost the same. Although most upstream eye development controlling genes were expressed in both species, six3/6 that are required for lens formation in vertebrates was not expressed in Nautilus. Furthermore, many downstream target genes of six3/6 including crystallin genes and other lens protein related genes were not expressed in Nautilus. As six3/6 and its controlling pathways are widely conserved among molluscs other than Nautilus, the present data suggest that deregulation of the six3/6 pathway led to the pinhole eye evolution in Nautilus.

Loss of the six3/6 controlling pathways might have resulted in pinhole-eye evolution in Nautilus

PubMed Central

Ogura, Atsushi; Yoshida, Masa-aki; Moritaki, Takeya; Okuda, Yuki; Sese, Jun; Shimizu, Kentaro K.; Sousounis, Konstantinos; Tsonis, Panagiotis A.

2013-01-01

Coleoid cephalopods have an elaborate camera eye whereas nautiloids have primitive pinhole eye without lens and cornea. The Nautilus pinhole eye provides a unique example to explore the module of lens formation and its evolutionary mechanism. Here, we conducted an RNA-seq study of developing eyes of Nautilus and pygmy squid. First, we found that evolutionary distances from the common ancestor to Nautilus or squid are almost the same. Although most upstream eye development controlling genes were expressed in both species, six3/6 that are required for lens formation in vertebrates was not expressed in Nautilus. Furthermore, many downstream target genes of six3/6 including crystallin genes and other lens protein related genes were not expressed in Nautilus. As six3/6 and its controlling pathways are widely conserved among molluscs other than Nautilus, the present data suggest that deregulation of the six3/6 pathway led to the pinhole eye evolution in Nautilus. PMID:23478590

Mitochondrial dysfunction associated with nitric oxide pathways in glutamate neurotoxicity.

PubMed

Manucha, Walter

Multiple mechanisms underlying glutamate-induced neurotoxicity have recently been discussed. Likewise, a clear deregulation of the mitochondrial respiratory mechanism has been described in patients with neurodegeneration, oxidative stress, and inflammation. This article highlights nitric oxide, an atypical neurotransmitter synthesized and released on demand by the post-synaptic neurons, and has many important implications for nerve cell survival and differentiation. Consequently, synaptogenesis, synapse elimination, and neurotransmitter release, are nitric oxide-modulated. Interesting, an emergent role of nitric oxide pathways has been discussed as regards neurotoxicity from glutamate-induced apoptosis. These findings suggest that nitric oxide pathways modulation could prevent oxidative damage to neurons through apoptosis inhibition. This review aims to highlight the emergent aspects of nitric oxide-mediated signaling in the brain, and how they can be related to neurotoxicity, as well as the development of neurodegenerative diseases development. Copyright © 2016 Sociedad Española de Arteriosclerosis. Publicado por Elsevier España, S.L.U. All rights reserved.

The HDAC inhibitor SAHA regulates CBX2 stability via a SUMO-triggered ubiquitin-mediated pathway in leukemia.

PubMed

Di Costanzo, Antonella; Del Gaudio, Nunzio; Conte, Lidio; Dell'Aversana, Carmela; Vermeulen, Michiel; de Thé, Hugues; Migliaccio, Antimo; Nebbioso, Angela; Altucci, Lucia

2018-05-01

Polycomb group (PcG) proteins regulate transcription, playing a key role in stemness and differentiation. Deregulation of PcG members is known to be involved in cancer pathogenesis. Emerging evidence suggests that CBX2, a member of the PcG protein family, is overexpressed in several human tumors, correlating with lower overall survival. Unraveling the mechanisms regulating CBX2 expression may thus provide a promising new target for anticancer strategies. Here we show that the HDAC inhibitor SAHA regulates CBX2 stability via a SUMO-triggered ubiquitin-mediated pathway in leukemia. We identify CBX4 and RNF4 as the E3 SUMO and E3 ubiquitin ligase, respectively, and describe the specific molecular mechanism regulating CBX2 protein stability. Finally, we show that CBX2-depleted leukemic cells display impaired proliferation, underscoring its critical role in regulating leukemia cell tumorogenicity. Our results show that SAHA affects CBX2 stability, revealing a potential SAHA-mediated anti-leukemic activity though SUMO2/3 pathway.

O-GlcNAc cycling: Emerging Roles in Development and Epigenetics

PubMed Central

Love, Dona C.; Krause, Michael W.; Hanover, John A.

2010-01-01

The nutrient-sensing hexosamine signaling pathway modulates the levels of O-linked N-acetylglucosamine (O-GlcNAc) on key targets impacting cellular signaling, protein turnover and gene expression. O-GlcNAc cycling may be deregulated in neurodegenerative disease, cancer, and diabetes. Studies in model organisms demonstrate that the O-GlcNAc transferase (OGT/Sxc) is essential for Polycomb group (PcG) repression of the homeotic genes, clusters of genes responsible for the adult body plan. Surprisingly, from flies to man, the O-GlcNAcase (OGA, MGEA5) gene is embedded within the NK cluster, the most evolutionarily ancient of three homeobox gene clusters regulated by PcG repression. PcG repression also plays a key role in maintaining stem cell identity, recruiting the DNA methyltransferase machinery for imprinting, and in X-chromosome inactivation. Intriguingly, the Ogt gene resides near the Xist locus in vertebrates and is subject to regulation by PcG-dependent X-inactivation. OGT is also an enzymatic component of the human dosage compensation complex. These ‘evo-devo’ relationships linking O-GlcNAc cycling to higher order chromatin structure provide insights into how nutrient availability may influence the epigenetic regulation of gene expression. O-GlcNAc cycling at promoters and PcG repression represent concrete mechanisms by which nutritional information may be transmitted across generations in the intra-uterine environment. Thus, the nutrient-sensing hexosamine signaling pathway may be a key contributor to the metabolic deregulation resulting from prenatal exposure to famine, or the ‘vicious cycle’ observed in children of mothers with type-2 diabetes and metabolic disease. PMID:20488252

Phloretin exhibits an anticancer effect and enhances the anticancer ability of cisplatin on non-small cell lung cancer cell lines by regulating expression of apoptotic pathways and matrix metalloproteinases.

PubMed

Ma, Lijie; Wang, Ruixuan; Nan, Yandong; Li, Wangping; Wang, Qingwei; Jin, Faguang

2016-02-01

Non-small cell lung cancer (NSCLC) accounts for 80-85% of all lung cancer cases and the prognosis of NSCLC patients is unsatisfactory since 5-year survival rate of NSCLC is still as low as 11%. Natural compounds derived from plants with few or no side effects have been recognized as alternative or auxiliary cure for cancer patients. Phloretin is such an agent possessing various pharmacological activities; however, there is scarce information on its anticancer effects on NSCLC. It was evaluated and confirmed, in the present study, that phloretin inhibited proliferation and induced apoptosis in A549, Calu-1, H838 and H520 cells in a dose-dependent manner, phloretin also suppressed the invasion and migration of NSCLC cells. We further confirmed that phloretin dose-dependently suppressed the expression of Bcl-2, increased the protein expression of cleaved-caspase-3 and -9, and deregulated the expression of matrix metalloproteinases (MMP)-2 and -9 on gene and protein levels. Besides, evaluations revealed that phloretin enhanced the anticancer effects of cisplatin on inhibition of proliferation and induction of apoptosis in NSCLC cells. Moreover, phloretin facilitated the effects of cisplatin on deregulation of Bcl-2, MMP-2 and -9, and upregulation of cleaved-caspase-3 and -9. In conclusion, the present study demonstrated that phloretin possessed anticancer effects and enhanced the anticancer effects of cisplatin on NSCLC cell lines by suppressing proliferation, inducing apoptosis and inhibiting invasion and migration of the cells through regulating apoptotic pathways and MMPs.

A data-driven network model of primary myelofibrosis: transcriptional and post-transcriptional alterations in CD34+ cells.

PubMed

Calura, E; Pizzini, S; Bisognin, A; Coppe, A; Sales, G; Gaffo, E; Fanelli, T; Mannarelli, C; Zini, R; Norfo, R; Pennucci, V; Manfredini, R; Romualdi, C; Guglielmelli, P; Vannucchi, A M; Bortoluzzi, S

2016-06-24

microRNAs (miRNAs) are relevant in the pathogenesis of primary myelofibrosis (PMF) but our understanding is limited to specific target genes and the overall systemic scenario islacking. By both knowledge-based and ab initio approaches for comparative analysis of CD34+ cells of PMF patients and healthy controls, we identified the deregulated pathways involving miRNAs and genes and new transcriptional and post-transcriptional regulatory circuits in PMF cells. These converge in a unique and integrated cellular process, in which the role of specific miRNAs is to wire, co-regulate and allow a fine crosstalk between the involved processes. The PMF pathway includes Akt signaling, linked to Rho GTPases, CDC42, PLD2, PTEN crosstalk with the hypoxia response and Calcium-linked cellular processes connected to cyclic AMP signaling. Nested on the depicted transcriptional scenario, predicted circuits are reported, opening new hypotheses. Links between miRNAs (miR-106a-5p, miR-20b-5p, miR-20a-5p, miR-17-5p, miR-19b-3p and let-7d-5p) and key transcription factors (MYCN, ATF, CEBPA, REL, IRF and FOXJ2) and their common target genes tantalizingly suggest new path to approach the disease. The study provides a global overview of transcriptional and post-transcriptional deregulations in PMF, and, unifying consolidated and predicted data, could be helpful to identify new combinatorial therapeutic strategy. Interactive PMF network model: http://compgen.bio.unipd.it/pmf-net/.

Constitutional trisomy 8 mosaicism as a model for epigenetic studies of aneuploidy

PubMed Central

2013-01-01

Background To investigate epigenetic patterns associated with aneuploidy we used constitutional trisomy 8 mosaicism (CT8M) as a model, enabling analyses of single cell clones, harboring either trisomy or disomy 8, from the same patient; this circumvents any bias introduced by using cells from unrelated, healthy individuals as controls. We profiled gene and miRNA expression as well as genome-wide and promoter specific DNA methylation and hydroxymethylation patterns in trisomic and disomic fibroblasts, using microarrays and methylated DNA immunoprecipitation. Results Trisomy 8-positive fibroblasts displayed a characteristic expression and methylation phenotype distinct from disomic fibroblasts, with the majority (65%) of chromosome 8 genes in the trisomic cells being overexpressed. However, 69% of all deregulated genes and non-coding RNAs were not located on this chromosome. Pathway analysis of the deregulated genes revealed that cancer, genetic disorder, and hematopoiesis were top ranked. The trisomy 8-positive cells displayed depletion of 5-hydroxymethylcytosine and global hypomethylation of gene-poor regions on chromosome 8, thus partly mimicking the inactivated X chromosome in females. Conclusions Trisomy 8 affects genes situated also on other chromosomes which, in cooperation with the observed chromosome 8 gene dosage effect, has an impact on the clinical features of CT8M, as demonstrated by the pathway analysis revealing key features that might explain the increased incidence of hematologic malignancies in CT8M patients. Furthermore, we hypothesize that the general depletion of hydroxymethylation and global hypomethylation of chromosome 8 may be unrelated to gene expression regulation, instead being associated with a general mechanism of chromatin processing and compartmentalization of additional chromosomes. PMID:23816241

Methylthioadenosine (MTA) Regulates Liver Cells Proteome and Methylproteome: Implications in Liver Biology and Disease*

PubMed Central

Bigaud, Emilie; Corrales, Fernando J.

2016-01-01

Methylthioadenosine phosphorylase (MTAP), a key enzyme in the adenine and methionine salvage pathways, catalyzes the hydrolysis of methylthioadenosine (MTA), a compound suggested to affect pivotal cellular processes in part through the regulation of protein methylation. MTAP is expressed in a wide range of cell types and tissues, and its deletion is common to cancer cells and in liver injury. The aim of this study was to investigate the proteome and methyl proteome alterations triggered by MTAP deficiency in liver cells to define novel regulatory mechanisms that may explain the pathogenic processes of liver diseases. iTRAQ analysis resulted in the identification of 216 differential proteins (p < 0.05) that suggest deregulation of cellular pathways as those mediated by ERK or NFκB. R-methyl proteome analysis led to the identification of 74 differentially methylated proteins between SK-Hep1 and SK-Hep1+ cells, including 116 new methylation sites. Restoring normal MTA levels in SK-Hep1+ cells parallels the specific methylation of 56 proteins, including KRT8, TGF, and CTF8A, which provides a novel regulatory mechanism of their activity with potential implications in carcinogenesis. Inhibition of RNA-binding proteins methylation is especially relevant upon accumulation of MTA. As an example, methylation of quaking protein in Arg242 and Arg256 in SK-Hep1+ cells may play a pivotal role in the regulation of its activity as indicated by the up-regulation of its target protein p27kip1. The phenotype associated with a MTAP deficiency was further verified in the liver of MTAP± mice. Our data support that MTAP deficiency leads to MTA accumulation and deregulation of central cellular pathways, increasing proliferation and decreasing the susceptibility to chemotherapeutic drugs, which involves differential protein methylation. Data are available via ProteomeXchange with identifier PXD002957 (http://www.ebi.ac.uk/pride/archive/projects/PXD002957). PMID:26819315

The Extracellular Adherence Protein from Staphylococcus aureus Inhibits the Classical and Lectin Pathways of Complement by Blocking Formation of the C3 Pro-Convertase

PubMed Central

Garcia, Brandon L.; Ramyar, Kasra X.; Keightley, Andrew; Ruyken, Maartje; Syriga, Maria; Sfyroera, Georgia; Weber, Alexander B.; Zolkiewski, Michal; Ricklin, Daniel; Lambris, John D.; Rooijakkers, Suzan H.M.; Geisbrecht, Brian V.

2014-01-01

The pathogenic bacterium Staphylococcus aureus actively evades many aspects of human innate immunity by expressing a series of small inhibitory proteins. A number of these proteins inhibit the complement system, which labels bacteria for phagocytosis and generates inflammatory chemoattractants. While the majority of staphylococcal complement inhibitors act on the alternative pathway (AP) to block the amplification loop, only a few proteins act on the initial recognition cascades that constitute the classical (CP) and lectin (LP) pathways. We screened a collection of recombinant, secreted staphylococcal proteins to determine if S. aureus produces other molecules that inhibit either the CP and/or LP. Using this approach, we identified the extracellular adherence protein (Eap) as a potent, specific inhibitor of both the CP and LP. We found that Eap blocked CP/LP-dependent activation of C3, but not C4, and that Eap likewise inhibited deposition of C3b on the surface of S. aureus cells. In turn, this significantly diminished the extent of S. aureus opsonophagocytosis and killing by neutrophils. This combination of functional properties suggested that Eap acts specifically at the level of the CP/LP C3 convertase (C4b2a). Indeed, we demonstrated a direct, nanomolar-affinity interaction of Eap with C4b. Eap binding to C4b inhibited binding of both full-length C2 and its C2b fragment, which indicated that Eap disrupts formation of the CP/LP C3 pro-convertase (C4b2). As a whole, our results demonstrate that S. aureus inhibits the two initiation routes of complement by expression of the Eap protein, and thereby define a novel mechanism of immune evasion. PMID:25381436

Overexpression of the Transcription Factor Sp1 Activates the OAS-RNAse L-RIG-I Pathway

PubMed Central

Dupuis-Maurin, Valéryane; Brinza, Lilia; Baguet, Joël; Plantamura, Emilie; Schicklin, Stéphane; Chambion, Solène; Macari, Claire; Tomkowiak, Martine; Deniaud, Emmanuelle; Leverrier, Yann

2015-01-01

Deregulated expression of oncogenes or transcription factors such as specificity protein 1 (Sp1) is observed in many human cancers and plays a role in tumor maintenance. Paradoxically in untransformed cells, Sp1 overexpression induces late apoptosis but the early intrinsic response is poorly characterized. In the present work, we studied increased Sp1 level consequences in untransformed cells and showed that it turns on an early innate immune transcriptome. Sp1 overexpression does not activate known cellular stress pathways such as DNA damage response or endoplasmic reticulum stress, but induces the activation of the OAS-RNase L pathway and the generation of small self-RNAs, leading to the upregulation of genes of the antiviral RIG-I pathway at the transcriptional and translational levels. Finally, Sp1-induced intrinsic innate immune response leads to the production of the chemokine CXCL4 and to the recruitment of inflammatory cells in vitro and in vivo. Altogether our results showed that increased Sp1 level in untransformed cells constitutes a novel danger signal sensed by the OAS-RNase L axis leading to the activation of the RIG-I pathway. These results suggested that the OAS-RNase L-RIG-I pathway may be activated in sterile condition in absence of pathogen. PMID:25738304

Molecular chaperone Hsp27 regulates the Hippo tumor suppressor pathway in cancer

PubMed Central

Vahid, Sepideh; Thaper, Daksh; Gibson, Kate F.; Bishop, Jennifer L.; Zoubeidi, Amina

2016-01-01

Heat shock protein 27 (Hsp27) is a molecular chaperone highly expressed in aggressive cancers, where it is involved in numerous pro-tumorigenic signaling pathways. Using functional genomics we identified for the first time that Hsp27 regulates the gene signature of transcriptional co-activators YAP and TAZ, which are negatively regulated by the Hippo Tumor Suppressor pathway. The Hippo pathway inactivates YAP by phosphorylating and increasing its cytoplasmic retention with the 14.3.3 proteins. Gain and loss of function experiments in prostate, breast and lung cancer cells showed that Hsp27 knockdown induced YAP phosphorylation and cytoplasmic localization while overexpression of Hsp27 displayed opposite results. Mechanistically, Hsp27 regulates the Hippo pathway by accelerating the proteasomal degradation of ubiquitinated MST1, the core Hippo kinase, resulting in reduced phosphorylation/activity of LATS1 and MOB1, its downstream effectors. Importantly, our in vitro results were supported by data from human tumors; clinically, high expression of Hsp27 in prostate tumors is correlated with increased expression of YAP gene signature and reduced phosphorylation of YAP in lung and invasive breast cancer clinical samples. This study reveals for the first time a link between Hsp27 and the Hippo cascade, providing a novel mechanism of deregulation of this tumor suppressor pathway across multiple cancers. PMID:27555231

Molecular chaperone Hsp27 regulates the Hippo tumor suppressor pathway in cancer.

PubMed

Vahid, Sepideh; Thaper, Daksh; Gibson, Kate F; Bishop, Jennifer L; Zoubeidi, Amina

2016-08-24

Heat shock protein 27 (Hsp27) is a molecular chaperone highly expressed in aggressive cancers, where it is involved in numerous pro-tumorigenic signaling pathways. Using functional genomics we identified for the first time that Hsp27 regulates the gene signature of transcriptional co-activators YAP and TAZ, which are negatively regulated by the Hippo Tumor Suppressor pathway. The Hippo pathway inactivates YAP by phosphorylating and increasing its cytoplasmic retention with the 14.3.3 proteins. Gain and loss of function experiments in prostate, breast and lung cancer cells showed that Hsp27 knockdown induced YAP phosphorylation and cytoplasmic localization while overexpression of Hsp27 displayed opposite results. Mechanistically, Hsp27 regulates the Hippo pathway by accelerating the proteasomal degradation of ubiquitinated MST1, the core Hippo kinase, resulting in reduced phosphorylation/activity of LATS1 and MOB1, its downstream effectors. Importantly, our in vitro results were supported by data from human tumors; clinically, high expression of Hsp27 in prostate tumors is correlated with increased expression of YAP gene signature and reduced phosphorylation of YAP in lung and invasive breast cancer clinical samples. This study reveals for the first time a link between Hsp27 and the Hippo cascade, providing a novel mechanism of deregulation of this tumor suppressor pathway across multiple cancers.

On the Functional Overlap between Complement and Anti-Microbial Peptides.

PubMed

Zimmer, Jana; Hobkirk, James; Mohamed, Fatima; Browning, Michael J; Stover, Cordula M

2014-01-01

Intriguingly, activated complement and anti-microbial peptides share certain functionalities; lytic, phagocytic, and chemo-attractant activities and each may, in addition, exert cell instructive roles. Each has been shown to have distinct LPS detoxifying activity and may play a role in the development of endotoxin tolerance. In search of the origin of complement, a functional homolog of complement C3 involved in opsonization has been identified in horseshoe crabs. Horseshoe crabs possess anti-microbial peptides able to bind to acyl chains or phosphate groups/saccharides of endotoxin, LPS. Complement activity as a whole is detectable in marine invertebrates. These are also a source of anti-microbial peptides with potential pharmaceutical applicability. Investigating the locality for the production of complement pathway proteins and their role in modulating cellular immune responses are emerging fields. The significance of local synthesis of complement components is becoming clearer from in vivo studies of parenchymatous disease involving specifically generated, complement-deficient mouse lines. Complement C3 is a central component of complement activation. Its provision by cells of the myeloid lineage varies. Their effector functions in turn are increased in the presence of anti-microbial peptides. This may point to a potentiating range of activities, which should serve the maintenance of health but may also cause disease. Because of the therapeutic implications, this review will consider closely studies dealing with complement activation and anti-microbial peptide activity in acute inflammation (e.g., dialysis-related peritonitis, appendicitis, and ischemia).

Bacteria-Phagocyte Interactions: Emerging Tactics in an Ancient Rivalry

DTIC Science & Technology

1990-01-01

afhitan. mechanisms by which microbes cvade the deposi- Mimicry of decay -accelerating factor aExample. T ’ruzi tion of immunogiobulin and complement on...their , Possible Isis of decay accelerating factor on host cell, surfaces have been well-studied (Table 2). For Example. Bacterial phospholipase example...activators of protein that mimics the action of decay accelerat- the alternate complement pathway 1171. ing factor (DAF) [261. This protein is part of a

The integrative epigenomic-transcriptomic landscape of ER positive breast cancer.

PubMed

Gao, Yang; Jones, Allison; Fasching, Peter A; Ruebner, Matthias; Beckmann, Matthias W; Widschwendter, Martin; Teschendorff, Andrew E

2015-01-01

While recent integrative analyses of copy number and gene expression data in breast cancer have revealed a complex molecular landscape with multiple subtypes and many oncogenic/tumour suppressor driver events, much less is known about the role of DNA methylation in shaping breast cancer taxonomy and defining driver events. Here, we applied a powerful integrative network algorithm to matched DNA methylation and RNA-Seq data for 724 estrogen receptor (ER)-positive (ER+) breast cancers and 111 normal adjacent tissue specimens from The Cancer Genome Atlas (TCGA) project, in order to identify putative epigenetic driver events and to explore the resulting molecular taxonomy. This revealed the existence of nine functionally deregulated epigenetic hotspots encompassing a total of 146 genes, which we were able to validate in independent data sets encompassing over 1000 ER+ breast cancers. Integrative clustering of the matched messenger RNA (mRNA) and DNA methylation data over these genes resulted in only two clusters, which correlated very strongly with the luminal-A and luminal B subtypes. Overall, luminal-A and luminal-B breast cancers shared the same epigenetically deregulated hotspots but with luminal-B cancers exhibiting increased aberrant DNA methylation patterns relative to normal tissue. We show that increased levels of DNA methylation and mRNA expression deviation from the normal state define a marker of poor prognosis. Our data further implicates epigenetic silencing of WNT signalling antagonists and bone morphogenetic proteins (BMP) as key events underlying both luminal subtypes but specially of luminal-B breast cancer. Finally, we show that DNA methylation changes within the identified epigenetic interactome hotspots do not exhibit mutually exclusive patterns within the same cancer sample, instead exhibiting coordinated changes within the sample. Our results indicate that the integrative DNA methylation and transcriptomic landscape of ER+ breast cancer is surprisingly homogeneous, defining two main subtypes which strongly correlate with luminal-A/B subtype status. In particular, we identify WNT and BMP signalling as key epigenetically deregulated tumour suppressor pathways in luminal ER+ breast cancer, with increased deregulation seen in luminal-B breast cancer.

Urinary Exosomal miRNA Signature in Type II Diabetic Nephropathy Patients

PubMed Central

Delić, Denis; Eisele, Claudia; Schmid, Ramona; Baum, Patrick; Wiech, Franziska; Gerl, Martin; Zimdahl, Heike; Pullen, Steven S.; Urquhart, Richard

2016-01-01

MicroRNAs (miRNAs) are short non-coding RNA species which are important post-transcriptional regulators of gene expression and play an important role in the pathogenesis of diabetic nephropathy. miRNAs are present in urine in a remarkably stable form packaged in extracellular vesicles, predominantly exosomes. In the present study, urinary exosomal miRNA profiling was conducted in urinary exosomes obtained from 8 healthy controls (C), 8 patients with type II diabetes (T2D) and 8 patients with type II diabetic nephropathy (DN) using Agilent´s miRNA microarrays. In total, the expression of 16 miRNA species was deregulated (>2-fold) in DN patients compared to healthy donors and T2D patients: the expression of 14 miRNAs (miR-320c, miR-6068, miR-1234-5p, miR-6133, miR-4270, miR-4739, miR-371b-5p, miR-638, miR-572, miR-1227-5p, miR-6126, miR-1915-5p, miR-4778-5p and miR-2861) was up-regulated whereas the expression of 2 miRNAs (miR-30d-5p and miR-30e-5p) was down-regulated. Most of the deregulated miRNAs are involved in progression of renal diseases. Deregulation of urinary exosomal miRNAs occurred in micro-albuminuric DN patients but not in normo-albuminuric DN patients. We used qRT-PCR based analysis of the most strongly up-regulated miRNAs in urinary exosomes from DN patients, miRNAs miR-320c and miR-6068. The correlation of miRNA expression and micro-albuminuria levels could be replicated in a confirmation cohort. In conclusion, urinary exosomal miRNA content is altered in type II diabetic patients with DN. Deregulated miR-320c, which might have an impact on the TGF-β-signaling pathway via targeting thrombospondin 1 (TSP-1) shows promise as a novel candidate marker for disease progression in type II DN that should be evaluated in future studies. PMID:26930277

Wound Healing and Cancer Stem Cells: Inflammation as a Driver of Treatment Resistance in Breast Cancer

PubMed Central

Arnold, Kimberly M; Opdenaker, Lynn M; Flynn, Daniel; Sims-Mourtada, Jennifer

2015-01-01

The relationship between wound healing and cancer has long been recognized. The mechanisms that regulate wound healing have been shown to promote transformation and growth of malignant cells. In addition, chronic inflammation has been associated with malignant transformation in many tissues. Recently, pathways involved in inflammation and wound healing have been reported to enhance cancer stem cell (CSC) populations. These cells, which are highly resistant to current treatments, are capable of repopulating the tumor after treatment, causing local and systemic recurrences. In this review, we highlight proinflammatory cytokines and developmental pathways involved in tissue repair, whose deregulation in the tumor microenvironment may promote growth and survival of CSCs. We propose that the addition of anti-inflammatory agents to current treatment regimens may slow the growth of CSCs and improve therapeutic outcomes. PMID:25674014

Can innate and autoimmune reactivity forecast early and advance stages of age-related macular degeneration?

PubMed

Adamus, Grazyna

2017-03-01

Age-related macular degeneration (AMD) is a major cause of central vision loss in persons over 55years of age in developed countries. AMD is a complex disease in which genetic, environmental and inflammatory factors influence its onset and progression. Elevation in serum anti-retinal autoantibodies, plasma and local activation of complement proteins of the alternative pathway, and increase in secretion of proinflammatory cytokines have been seen over the course of disease. Genetic studies of AMD patients confirmed that genetic variants affecting the alternative complement pathway have a major influence on AMD risk. Because the heterogeneity of this disease, there is no sufficient strategy to identify the disease onset and progression sole based eye examination, thus identification of reliable serological biomarkers for diagnosis, prognosis and response to treatment by sampling patient's blood is necessary. This review provides an outline of the current knowledge on possible serological (autoantibodies, complement factors, cytokines, chemokines) and related genetic biomarkers relevant to the pathology of AMD, and discusses their application for prediction of disease activity and prognosis in AMD. Copyright © 2017 Elsevier B.V. All rights reserved.

Regulation of macrophage migration by products of the complement system.

PubMed Central

Bianco, C; Götze, O; Cohn, Z A

1979-01-01

Agents formerly shown to induce rapid macrophage spreading were examined for their ability to modify the migration of macrophages in the capillary tube assay. Products of the activation of the contact phase of blood coagulation as well as the purified component Bb, the large cleavage fragment of factor B of the alternative complement pathway produced a dose-dependent inhibition of migration. In addition, inflammatory macrophages elicited with either a lipopolysaccharide endotoxin or thioglycollate medium exhibited rapid spreading and inhibited migration, whereas resident cells did not. A close correlation existed, therefore, between enhanced spreading and inhibited migration under both in vitro induced and in vivo situations. Cleavage products of component C5 of the classical complement pathway enhanced macrophage migration and did not alter spreading. In mixtures of C5 cleavage products and Bb, the predominant peptide determined the outcome of the reaction. Factor B, a normal secretory product of macrophages, may represent a common substrate for several of the proteases that induce spreading, inhibit migration, and lead to the generation of the enzymatically active fragment Bb. PMID:284412

Two mannose-binding lectin homologues and an MBL-associated serine protease are expressed in the gut epithelia of the urochordate species Ciona intestinalis.

PubMed

Skjoedt, Mikkel-Ole; Palarasah, Yaseelan; Rasmussen, Karina; Vitved, Lars; Salomonsen, Jan; Kliem, Anette; Hansen, Soren; Koch, Claus; Skjodt, Karsten

2010-01-01

The lectin complement pathway has important functions in vertebrate host defence and accumulating evidence of primordial complement components trace its emergence to invertebrate phyla. We introduce two putative mannose-binding lectin homologues (CioMBLs) from the urochordate species Ciona intestinalis. The CioMBLs display similarities with vertebrate MBLs and comprise a collagen-like region, alpha-helical coiled-coils and a carbohydrate recognition domain (CRD) with conserved residues involved in calcium and carbohydrate binding. Structural analysis revealed an oligomerization through interchain disulphide bridges between N-terminal cysteine residues and cysteines located between the neck region and the CRD. RT-PCR showed a tissue specific expression of CioMBL in the gut and by immunohistochemistry analysis we also demonstrated that CioMBL co-localize with an MBL-associated serine protease in the epithelia cells lining the stomach and intestine. In conclusion we present two urochordate MBLs and identify an associated serine protease, which support the concept of an evolutionary ancient origin of the lectin complement pathway.

Evasion of Complement-Mediated Lysis and Complement C3 Deposition Are Regulated by Francisella tularensis Lipopolysaccharide O Antigen1

PubMed Central

Clay, Corey D.; Soni, Shilpa; Gunn, John S.; Schlesinger, Larry S.

2009-01-01

The bacterium Francisella tularensis (Ft) is a potential weapon of bioterrorism when aerosolized. Macrophage infection is necessary for disease progression and efficient phagocytosis by human macrophages requires serum opsonization by complement. Microbial complement activation leads to surface deposition of a highly regulated protein complex resulting in opsonization or membrane lysis. The nature of complement component C3 deposition, i.e., C3b (opsonization and lysis) or C3bi (opsonization only) fragment deposition, is central to the outcome of activation. In this study, we examine the mechanisms of Ft resistance to complement-mediated lysis, C3 component deposition on the Ft surface, and complement activation. Upon incubation in fresh nonimmune human serum, Schu S4 (Ft subsp. tularensis), Fn (Ft subsp. novicida), and LVS (Ft subsp. holarctica live vaccine strain) were resistant to complement-mediated lysis, but LVSG and LVSR (LVS strains altered in surface carbohydrate structures) were susceptible. C3 deposition, however, occurred on all strains. Complement-susceptible strains had markedly increased C3 fragment deposition, including the persistent presence of C3b compared with C3bi, which indicates that C3b inactivation results in survival of complement-resistant strains. C1q, an essential component of the classical activation pathway, was necessary for lysis of complement-susceptible strains and optimal C3 deposition on all strains. Finally, use of Francisella LPS mutants confirmed O Ag as a major regulator of complement resistance. These data provide evidence that pathogenic Francisella activate complement, but are resistant to complement-mediated lysis in part due to limited C3 deposition, rapid conversion of surface-bound C3b to C3bi, and the presence of LPS O Ag. PMID:18832715

Soya bean Gα proteins with distinct biochemical properties exhibit differential ability to complement Saccharomyces cerevisiae gpa1 mutant.

PubMed

Roy Choudhury, Swarup; Wang, Yuqi; Pandey, Sona

2014-07-01

Signalling pathways mediated by heterotrimeric G-proteins are common to all eukaryotes. Plants have a limited number of each of the G-protein subunits, with the most elaborate G-protein network discovered so far in soya bean (Glycine max, also known as soybean) which has four Gα, four Gβ and ten Gγ proteins. Biochemical characterization of Gα proteins from plants suggests significant variation in their properties compared with the well-characterized non-plant proteins. Furthermore, the four soya bean Gα (GmGα) proteins exhibit distinct biochemical activities among themselves, but the extent to which such biochemical differences contribute to their in vivo function is also not known. We used the yeast gpa1 mutant which displays constitutive signalling and growth arrest in the pheromone-response pathway as an in vivo model to evaluate the effect of distinct biochemical activities of GmGα proteins. We showed that specific GmGα proteins can be activated during pheromone-dependent receptor-mediated signalling in yeast and they display different strengths towards complementation of yeast gpa1 phenotypes. We also identified amino acids that are responsible for differential complementation abilities of specific Gα proteins. These data establish that specific plant Gα proteins are functional in the receptor-mediated pheromone-response pathway in yeast and that the subtle biochemical differences in their activity are physiologically relevant.

Transcriptional Changes That Characterize the Immune Reactions of Leprosy

PubMed Central

Dupnik, Kathryn M.; Bair, Thomas B.; Maia, Andressa O.; Amorim, Francianne M.; Costa, Marcos R.; Keesen, Tatjana S. L.; Valverde, Joanna G.; Queiroz, Maria do Carmo A. P.; Medeiros, Lúcio L.; de Lucena, Nelly L.; Wilson, Mary E.; Nobre, Mauricio L.; Johnson, Warren D.; Jeronimo, Selma M. B.

2015-01-01

Background. Leprosy morbidity is increased by 2 pathologic immune reactions, reversal reaction (RR) and erythema nodosum leprosum (ENL). Methods. To discover host factors related to immune reactions, global transcriptional profiles of peripheral blood mononuclear cells were compared between 11 RR, 11 ENL, and 19 matched control patients, with confirmation by quantitative polymerase chain reaction. Encoded proteins were investigated in skin biopsy specimens by means of immunohistochemistry. Results. There were 275 genes differentially expressed in RR and 517 differentially expressed in ENL on the microarray. Pathway analysis showed immunity-related pathways represented in RR and ENL transcriptional profiles, with the “complement and coagulation” pathway common to both. Interferon γ was identified as a significant upstream regulator of the expression changes for RR and ENL. Immunohistochemical staining of skin lesions showed increased C1q in both RR and ENL. Conclusions. These data suggest a previously underrecognized role for complement in the pathogenesis of both RR and ENL, and we propose new hypotheses for reaction pathogenesis. PMID:25398459

Deregulating electricity in the American states

NASA Astrophysics Data System (ADS)

Terbush, Thomas Lee

This dissertation develops nine stylized facts that summarize the major consequences of deregulation and tests these against recent experience in the electric utility industry. The experience of the electric utility industry matches the predictions of the stylized facts, except in one instance: although real electricity prices fell between 1982 and 1999, real prices fell less in states that deregulated. This dissertation presents three possible explanations for this discrepancy. First, through dynamic efficiency, consumers may benefit in the long run through lower rates and better service in the electricity market, or deregulation may be a public good that benefits electricity consumers through economy-wide improvements in efficiency. Second, higher prices may be a long-run outcome as predicted by the theory of the second best. Or third, both regulators and utilities may use deregulation to generate new rents. Because the original rents from regulation had dissipated, new rents could be generated under deregulation by making consumers pay off the utilities and then creating more new rents through re-regulation of the industry. Close examination tends to support the first and third explanations, although the second-best explanation cannot yet be ruled out completely. Higher prices appear to be a transitional phenomenon, resulting from a short-term payoff from consumers to incumbent utilities that was required to move deregulation forward. This payoff occurs as residential and commercial consumers bear relatively higher rates over three to five years to compensate utilities for stranded costs, investments thought to be unrecoverable under full competition. All states are benefiting from deregulation, but states that are deregulating are benefiting less while stranded costs are being recovered. This dissertation also examines California electricity deregulation and finds that the experience in California conforms with to the stylized facts, and that certain structural, demand and supply factors caused the electricity crisis in 2000 and 2001. The most important factor was the disallowance of long-term contracts and other instruments for shedding price risk, which discouraged the construction of new generating plants.

Complement factor H is expressed in adipose tissue in association with insulin resistance.

PubMed

Moreno-Navarrete, José María; Martínez-Barricarte, Rubén; Catalán, Victoria; Sabater, Mònica; Gómez-Ambrosi, Javier; Ortega, Francisco José; Ricart, Wifredo; Blüher, Mathias; Frühbeck, Gema; Rodríguez de Cordoba, Santiago; Fernández-Real, José Manuel

2010-01-01

Activation of the alternative pathway of the complement system, in which factor H (fH; complement fH [CFH]) is a key regulatory component, has been suggested as a link between obesity and metabolic disorders. Our objective was to study the associations between circulating and adipose tissue gene expressions of CFH and complement factor B (fB; CFB) with obesity and insulin resistance. Circulating fH and fB were determined by enzyme-linked immunosorbent assay in 398 subjects. CFH and CFB gene expressions were evaluated in 76 adipose tissue samples, in isolated adipocytes, and in stromovascular cells (SVC) (n = 13). The effects of weight loss and rosiglitazone were investigated in independent cohorts. Both circulating fH and fB were associated positively with BMI, waist circumference, triglycerides, and inflammatory parameters and negatively with insulin sensitivity and HDL cholesterol. For the first time, CFH gene expression was detected in human adipose tissue (significantly increased in subcutaneous compared with omental fat). CFH gene expression in omental fat was significantly associated with insulin resistance. In contrast, CFB gene expression was significantly increased in omental fat but also in association with fasting glucose and triglycerides. The SVC fraction was responsible for these differences, although isolated adipocytes also expressed fB and fH at low levels. Both weight loss and rosiglitazone led to significantly decreased circulating fB and fH levels. Increased circulating fH and fB concentrations in subjects with altered glucose tolerance could reflect increased SVC-induced activation of the alternative pathway of complement in omental adipose tissue linked to insulin resistance and metabolic disturbances.

Characterization of the complement inhibitory function of rhesus rhadinovirus complement control protein (RCP).

PubMed

Okroj, Marcin; Mark, Linda; Stokowska, Anna; Wong, Scott W; Rose, Nicola; Blackbourn, David J; Villoutreix, Bruno O; Spiller, O Brad; Blom, Anna M

2009-01-02

Rhesus rhadinovirus (RRV) is currently the closest known, fully sequenced homolog of human Kaposi sarcoma-associated herpesvirus. Both these viruses encode complement inhibitors as follows: Kaposi sarcoma-associated herpesvirus-complement control protein (KCP) and RRV-complement control protein (RCP). Previously we characterized in detail the functional properties of KCP as a complement inhibitor. Here, we performed comparative analyses for two variants of RCP protein, encoded by RRV strains H26-95 and 17577. Both RCP variants and KCP inhibited human and rhesus complement when tested in hemolytic assays measuring all steps of activation via the classical and the alternative pathway. RCP variants from both RRV strains supported C3b and C4b degradation by factor I and decay acceleration of the classical C3 convertase, similar to KCP. Additionally, the 17577 RCP variant accelerated decay of the alternative C3 convertase, which was not seen for KCP. In contrast to KCP, RCP showed no affinity to heparin and is the first described complement inhibitor in which the binding site for C3b/C4b does not interact with heparin. Molecular modeling shows a structural disruption in the region of RCP that corresponds to the KCP-heparin-binding site. This makes RRV a superior model for future in vivo investigations of complement evasion, as RCP does not play a supportive role in viral attachment as KCP does.

Epigenetic Heterogeneity of B-Cell Lymphoma: Chromatin Modifiers

PubMed Central

Hopp, Lydia; Nersisyan, Lilit; Löffler-Wirth, Henry; Arakelyan, Arsen; Binder, Hans

2015-01-01

We systematically studied the expression of more than fifty histone and DNA (de)methylating enzymes in lymphoma and healthy controls. As a main result, we found that the expression levels of nearly all enzymes become markedly disturbed in lymphoma, suggesting deregulation of large parts of the epigenetic machinery. We discuss the effect of DNA promoter methylation and of transcriptional activity in the context of mutated epigenetic modifiers such as EZH2 and MLL2. As another mechanism, we studied the coupling between the energy metabolism and epigenetics via metabolites that act as cofactors of JmjC-type demethylases. Our study results suggest that Burkitt’s lymphoma and diffuse large B-cell Lymphoma differ by an imbalance of repressive and poised promoters, which is governed predominantly by the activity of methyltransferases and the underrepresentation of demethylases in this regulation. The data further suggest that coupling of epigenetics with the energy metabolism can also be an important factor in lymphomagenesis in the absence of direct mutations of genes in metabolic pathways. Understanding of epigenetic deregulation in lymphoma and possibly in cancers in general must go beyond simple schemes using only a few modes of regulation. PMID:26506391

Multiple myeloma-related deregulation of bone marrow-derived CD34(+) hematopoietic stem and progenitor cells.

PubMed

Bruns, Ingmar; Cadeddu, Ron-Patrick; Brueckmann, Ines; Fröbel, Julia; Geyh, Stefanie; Büst, Sebastian; Fischer, Johannes C; Roels, Frederik; Wilk, Christian Matthias; Schildberg, Frank A; Hünerlitürkoglu, Ali-Nuri; Zilkens, Christoph; Jäger, Marcus; Steidl, Ulrich; Zohren, Fabian; Fenk, Roland; Kobbe, Guido; Brors, Benedict; Czibere, Akos; Schroeder, Thomas; Trumpp, Andreas; Haas, Rainer

2012-09-27

Multiple myeloma (MM) is a clonal plasma cell disorder frequently accompanied by hematopoietic impairment. We show that hematopoietic stem and progenitor cells (HSPCs), in particular megakaryocyte-erythrocyte progenitors, are diminished in the BM of MM patients. Genomic profiling of HSPC subsets revealed deregulations of signaling cascades, most notably TGFβ signaling, and pathways involved in cytoskeletal organization, migration, adhesion, and cell-cycle regulation in the patients. Functionally, proliferation, colony formation, and long-term self-renewal were impaired as a consequence of activated TGFβ signaling. In accordance, TGFβ levels in the BM extracellular fluid were elevated and mesenchymal stromal cells (MSCs) had a reduced capacity to support long-term hematopoiesis of HSPCs that completely recovered on blockade of TGFβ signaling. Furthermore, we found defective actin assembly and down-regulation of the adhesion receptor CD44 in MM HSPCs functionally reflected by impaired migration and adhesion. Still, transplantation into myeloma-free NOG mice revealed even enhanced engraftment and normal differentiation capacities of MM HSPCs, which underlines that functional impairment of HSPCs depends on MM-related microenvironmental cues and is reversible. Taken together, these data implicate that hematopoietic suppression in MM emerges from the HSPCs as a result of MM-related microenvironmental alterations.

RSK regulates activated BRAF signalling to mTORC1 and promotes melanoma growth

PubMed Central

Zindy, Pierre-Joachim; Saba-El-Leil, Marc; Lavoie, Geneviève; Dandachi, Farah; Baptissart, Marine; Borden, Katherine L. B.; Meloche, Sylvain; Roux, Philippe P.

2015-01-01

The Ras/mitogen-activated protein kinase (MAPK) signalling cascade regulates various biological functions, including cell growth, proliferation and survival. As such, this pathway is often deregulated in cancer, including melanomas, which frequently harbour activating mutations in the NRAS and BRAF oncogenes. Hyperactive MAPK signalling is known to promote protein synthesis, but the mechanisms by which this occurs remain poorly understood. Here, we show that expression of oncogenic forms of Ras and Raf promotes the constitutive activation of the mammalian target of rapamycin (mTOR). Using pharmacological inhibitors and RNA interference we find that the MAPK-activated protein kinase RSK (p90 ribosomal S6 kinase) is partly required for these effects. Using melanoma cell lines carrying activating BRAF mutations we show that ERK/RSK signalling regulates assembly of the translation initiation complex and polysome formation, as well as the translation of growth-related mRNAs containing a 5’ terminal oligopyrimidine (TOP) motif. Accordingly, we find that RSK inhibition abrogates tumour growth in mice. Our findings indicate that RSK may be a valuable therapeutic target for the treatment of tumours characterized by deregulated MAPK signalling, such as melanoma. PMID:22797077

Interorgan Communication Pathways in Physiology: Focus on Drosophila

PubMed Central

Droujinine, Ilia A.; Perrimon, Norbert

2017-01-01

Studies in mammals and Drosophila have demonstrated the existence and significance of secreted factors involved in communication between distal organs. In this review, primarily focusing on Drosophila, we examine the known interorgan communication factors and their functions, physiological inducers, and integration in regulating physiology. Moreover, we describe how organ-sensing screens in Drosophila can systematically identify novel conserved interorgan communication factors. Finally, we discuss how interorgan communication enabled and evolved as a result of specialization of organs. Together, we anticipate that future studies will establish a model for metazoan interorgan communication network (ICN) and how it is deregulated in disease. PMID:27732790

Interorgan Communication Pathways in Physiology: Focus on Drosophila.

PubMed

Droujinine, Ilia A; Perrimon, Norbert

2016-11-23

Studies in mammals and Drosophila have demonstrated the existence and significance of secreted factors involved in communication between distal organs. In this review, primarily focusing on Drosophila, we examine the known interorgan communication factors and their functions, physiological inducers, and integration in regulating physiology. Moreover, we describe how organ-sensing screens in Drosophila can systematically identify novel conserved interorgan communication factors. Finally, we discuss how interorgan communication enabled and evolved as a result of specialization of organs. Together, we anticipate that future studies will establish a model for metazoan interorgan communication network (ICN) and how it is deregulated in disease.

Converging roles for sphingolipids and cell stress in the progression of neurological dysfunction in AIDS

PubMed Central

Haughey, Norman J.; Steiner, Joesph; Nath, Avindra; McArthur, Justin; Sacktor, Ned; Pardo, Carlos; Bandaru, Veera Venkata Ratnam

2009-01-01

Sphingolipids are a class of lipids enriched in the central nervous system that have important roles in signal transduction. Recent advances in our understanding of how sphingolipids are involved in the control of life and death signaling have uncovered roles for these lipids in the neuropathogenesis of HIV-associated neurocognitive disorders (HAND). In this review we briefly summarize the molecular mechanisms involved in the pathological production of the toxic sphingolipid, ceramide and address questions of how cytokine and cellular stress pathways that are perturbed in HAND converge to deregulate ceramide-associated signaling. PMID:18508574

Integration of targeted metabolomics and transcriptomics identifies deregulation of phosphatidylcholine metabolism in Huntington's disease peripheral blood samples.

PubMed

Mastrokolias, Anastasios; Pool, Rene; Mina, Eleni; Hettne, Kristina M; van Duijn, Erik; van der Mast, Roos C; van Ommen, GertJan; 't Hoen, Peter A C; Prehn, Cornelia; Adamski, Jerzy; van Roon-Mom, Willeke

Metabolic changes have been frequently associated with Huntington's disease (HD). At the same time peripheral blood represents a minimally invasive sampling avenue with little distress to Huntington's disease patients especially when brain or other tissue samples are difficult to collect. We investigated the levels of 163 metabolites in HD patient and control serum samples in order to identify disease related changes. Additionally, we integrated the metabolomics data with our previously published next generation sequencing-based gene expression data from the same patients in order to interconnect the metabolomics changes with transcriptional alterations. This analysis was performed using targeted metabolomics and flow injection electrospray ionization tandem mass spectrometry in 133 serum samples from 97 Huntington's disease patients (29 pre-symptomatic and 68 symptomatic) and 36 controls. By comparing HD mutation carriers with controls we identified 3 metabolites significantly changed in HD (serine and threonine and one phosphatidylcholine-PC ae C36:0) and an additional 8 phosphatidylcholines (PC aa C38:6, PC aa C36:0, PC ae C38:0, PC aa C38:0, PC ae C38:6, PC ae C42:0, PC aa C36:5 and PC ae C36:0) that exhibited a significant association with disease severity. Using workflow based exploitation of pathway databases and by integrating our metabolomics data with our gene expression data from the same patients we identified 4 deregulated phosphatidylcholine metabolism related genes ( ALDH1B1 , MBOAT1 , MTRR and PLB1 ) that showed significant association with the changes in metabolite concentrations. Our results support the notion that phosphatidylcholine metabolism is deregulated in HD blood and that these metabolite alterations are associated with specific gene expression changes.

Folliculin (Flcn) inactivation leads to murine cardiac hypertrophy through mTORC1 deregulation

PubMed Central

Hasumi, Yukiko; Baba, Masaya; Hasumi, Hisashi; Huang, Ying; Lang, Martin; Reindorf, Rachel; Oh, Hyoung-bin; Sciarretta, Sebastiano; Nagashima, Kunio; Haines, Diana C.; Schneider, Michael D.; Adelstein, Robert S.; Schmidt, Laura S.; Sadoshima, Junichi; Marston Linehan, W.

2014-01-01

Cardiac hypertrophy, an adaptive process that responds to increased wall stress, is characterized by the enlargement of cardiomyocytes and structural remodeling. It is stimulated by various growth signals, of which the mTORC1 pathway is a well-recognized source. Here, we show that loss of Flcn, a novel AMPK–mTOR interacting molecule, causes severe cardiac hypertrophy with deregulated energy homeostasis leading to dilated cardiomyopathy in mice. We found that mTORC1 activity was upregulated in Flcn-deficient hearts, and that rapamycin treatment significantly reduced heart mass and ameliorated cardiac dysfunction. Phospho-AMP-activated protein kinase (AMPK)-alpha (T172) was reduced in Flcn-deficient hearts and nonresponsive to various stimulations including metformin and AICAR (5-amino-1-β-D-ribofuranosyl-imidazole-4-carboxamide). ATP levels were elevated and mitochondrial function was increased in Flcn-deficient hearts, suggesting that excess energy resulting from up-regulated mitochondrial metabolism under Flcn deficiency might attenuate AMPK activation. Expression of Ppargc1a, a central molecule for mitochondrial metabolism, was increased in Flcn-deficient hearts and indeed, inactivation of Ppargc1a in Flcn-deficient hearts significantly reduced heart mass and prolonged survival. Ppargc1a inactivation restored phospho-AMPK-alpha levels and suppressed mTORC1 activity in Flcn-deficient hearts, suggesting that up-regulated Ppargc1a confers increased mitochondrial metabolism and excess energy, leading to inactivation of AMPK and activation of mTORC1. Rapamycin treatment did not affect the heart size of Flcn/Ppargc1a doubly inactivated hearts, further supporting the idea that Ppargc1a is the critical element leading to deregulation of the AMPK–mTOR-axis and resulting in cardiac hypertrophy under Flcn deficiency. These data support an important role for Flcn in cardiac homeostasis in the murine model. PMID:24908670

Global microRNA profiling of peripheral blood mononuclear cells in patients with Behçet's disease.

PubMed

Erre, Gian Luca; Piga, Matteo; Carru, Ciriaco; Angius, Andrea; Carcangiu, Laura; Piras, Marco; Sotgia, Salvatore; Zinellu, Angelo; Mathieu, Alessandro; Passiu, Giuseppe; Pescatori, Mario

2015-01-01

To explore the post-transcriptional regulation of the peripheral blood mononuclear cells (PBMCs) transcriptome by microRNAs in Behçet's disease (BD). Using TaqMan Low Density Array-based microRNAs expression profiling, the expression of 750 mature human microRNAs in PBMCs from 5 BD patients and 3 healthy controls (HC) was compared. The expression of deregulated microRNAs was then validated by quantitative real time-polymerase chain reaction (qRT-PCR), in 42 BD patients and 8 HC. In the initial screening, 13 microRNAs appeared deregulated in BD vs HC. Among them, the differential expression of miR-720 and miR-139-3p was confirmed by qRT-PCR, (p<0.05 and FDR<5%). Areas under the receiver operating characteristic curve for miR-139-3p, miR-720 and miR-139-3p+miR-720 in the validation cohort were 0.84, 0.87 and 0.92 respectively, indicating good discrimination between BD patients and HC. Post-hoc analysis showed that 9 out of 13 microRNAs from the discovery phase were significantly upregulated in active vs. quiescent BD, suggesting inflammation as a key regulator of microRNAs machinery in BD. In silico analysis revealed that several BD candidate susceptibility genes are predicted target of significantly deregulated microRNAs in active BD. A significant enrichment in microRNAs targeting elements of the Toll-like receptor (TLR) and T-cell receptor signalling pathways was also assumed. miR199-3p and miR720 deserve further confirmation as biomarkers of BD in larger studies. PBMCs from active BD displayed a unique signature of microRNAs which may be implicated in regulation of innate immunity activation and T-cell function.

Integrated expression analysis identifies transcription networks in mouse and human gastric neoplasia.

PubMed

Chen, Zheng; Soutto, Mohammed; Rahman, Bushra; Fazili, Muhammad W; Peng, DunFa; Blanca Piazuelo, Maria; Chen, Heidi; Kay Washington, M; Shyr, Yu; El-Rifai, Wael

2017-07-01

Gastric cancer (GC) is a leading cause of cancer-related deaths worldwide. The Tff1 knockout (KO) mouse model develops gastric lesions that include low-grade dysplasia (LGD), high-grade dysplasia (HGD), and adenocarcinomas. In this study, we used Affymetrix microarrays gene expression platforms for analysis of molecular signatures in the mouse stomach [Tff1-KO (LGD) and Tff1 wild-type (normal)] and human gastric cancer tissues and their adjacent normal tissue samples. Combined integrated bioinformatics analysis of mouse and human datasets indicated that 172 genes were consistently deregulated in both human gastric cancer samples and Tff1-KO LGD lesions (P < .05). Using Ingenuity pathway analysis, these genes mapped to important transcription networks that include MYC, STAT3, β-catenin, RELA, NFATC2, HIF1A, and ETS1 in both human and mouse. Further analysis demonstrated activation of FOXM1 and inhibition of TP53 transcription networks in human gastric cancers but not in Tff1-KO LGD lesions. Using real-time RT-PCR, we validated the deregulated expression of several genes (VCAM1, BGN, CLDN2, COL1A1, COL1A2, COL3A1, EpCAM, IFITM1, MMP9, MMP12, MMP14, PDGFRB, PLAU, and TIMP1) that map to altered transcription networks in both mouse and human gastric neoplasia. Our study demonstrates significant similarities in deregulated transcription networks in human gastric cancer and gastric tumorigenesis in the Tff1-KO mouse model. The data also suggest that activation of MYC, STAT3, RELA, and β-catenin transcription networks could be an early molecular step in gastric carcinogenesis. © 2017 Wiley Periodicals, Inc.

Progress with palbociclib in breast cancer: latest evidence and clinical considerations

PubMed Central

Rocca, Andrea; Schirone, Alessio; Maltoni, Roberta; Bravaccini, Sara; Cecconetto, Lorenzo; Farolfi, Alberto; Bronte, Giuseppe; Andreis, Daniele

2016-01-01

Deregulation of the cell cycle is a hallmark of cancer, and research on cell cycle control has allowed identification of potential targets for anticancer treatment. Palbociclib is a selective inhibitor of the cyclin-dependent kinases 4 and 6 (CDK4/6), which are involved, with their coregulatory partners cyclin D, in the G1-S transition. Inhibition of this step halts cell cycle progression in cells in which the involved pathway, including the retinoblastoma protein (Rb) and the E2F family of transcription factors, is functioning, although having been deregulated. Among breast cancers, those with functioning cyclin D-CDK4/6-Rb-E2F are mainly hormone-receptor (HR) positive, with some HER2-positive and rare triple-negative cases. Deregulation results from genetic or otherwise occurring hyperactivation of molecules subtending cell cycle progression, or inactivation of cell cycle inhibitors. Based on results of randomized clinical trials, palbociclib was granted accelerated approval by the US Food and Drug Administration (FDA) for use in combination with letrozole as initial endocrine-based therapy for metastatic disease in postmenopausal women with HR-positive, HER2-negative breast cancer, and was approved for use in combination with fulvestrant in women with HR-positive, HER2-negative advanced breast cancer with disease progression following endocrine therapy. This review provides an update of the available knowledge on the cell cycle and its regulation, on the alterations in cyclin D-CDK4/6-Rb-E2F axis in breast cancer and their roles in endocrine resistance, on the preclinical activity of CDK4/6 inhibitors in breast cancer, both as monotherapy and as partners of combinatorial synergic treatments, and on the clinical development of palbociclib in breast cancer. PMID:28203301

Differential Gene Expression in Colon Tissue Associated With Diet, Lifestyle, and Related Oxidative Stress.

PubMed

Slattery, Martha L; Pellatt, Daniel F; Mullany, Lila E; Wolff, Roger K

2015-01-01

Several diet and lifestyle factors may impact health by influencing oxidative stress levels. We hypothesize that level of cigarette smoking, alcohol, anti-inflammatory drugs, and diet alter gene expression. We analyzed RNA-seq data from 144 colon cancer patients who had information on recent cigarette smoking, recent alcohol consumption, diet, and recent aspirin/non-steroidal anti-inflammatory use. Using a false discovery rate of 0.1, we evaluated gene differential expression between high and low levels of exposure using DESeq2. Ingenuity Pathway Analysis (IPA) was used to determine networks associated with de-regulated genes in our data. We identified 46 deregulated genes associated with recent cigarette use; these genes enriched causal networks regulated by TEK and MAP2K3. Different differentially expressed genes were associated with type of alcohol intake; five genes were associated with total alcohol, six were associated with beer intake, six were associated with wine intake, and four were associated with liquor consumption. Recent use of aspirin and/or ibuprofen was associated with differential expression of TMC06, ST8SIA4, and STEAP3 while a summary oxidative balance score (OBS) was associated with SYCP3, HDX, and NRG4 (all up-regulated with greater oxidative balance). Of the dietary antioxidants and carotenoids evaluated only intake of beta carotene (1 gene), Lutein/Zeaxanthine (5 genes), and Vitamin E (4 genes) were associated with differential gene expression. There were similarities in biological function of de-regulated genes associated with various dietary and lifestyle factors. Our data support the hypothesis that diet and lifestyle factors associated with oxidative stress can alter gene expression. However genes altered were unique to type of alcohol and type of antioxidant. Because of potential differences in associations observed between platforms these findings need replication in other populations.

Telecommunications Policy Research Conference. Regulation, Deregulation & Competition Section. Papers.

ERIC Educational Resources Information Center

Telecommunications Policy Research Conference, Inc., Washington, DC.

Three papers discuss aspects of telecommunications regulation in a deregulated environment. The first paper, "Implementing Telephone Deregulation: The Political Economy of State Regulation in the Post-Divestiture Era" (Paul E. Teske), analyzed the variation in state regulation of local telephone operating companies using regression…

Complement Interaction with Trypanosomatid Promastigotes in Normal Human Serum

PubMed Central

Domínguez, Mercedes; Moreno, Inmaculada; López-Trascasa, Margarita; Toraño, Alfredo

2002-01-01

In normal human serum (NHS), axenic promastigotes of Crithidia, Phytomonas, and Leishmania trigger complement activation, and from 1.2 to 1.8 × 105 C3 molecules are deposited per promastigote within 2.5 min. In Leishmania, promastigote C3 binding capacity remains constant during in vitro metacyclogenesis. C3 deposition on promastigotes activated through the classical complement pathway reaches a 50% maximum after ∼50 s, and represents >85% of total C3 bound. In C1q- and C2-deficient human sera, promastigotes cannot activate the classical pathway (CP) unless purified C1q or C2 factors, respectively, are supplemented, demonstrating a requirement for CP factor in promastigote C3 opsonization. NHS depleted of natural anti-Leishmania antibodies cannot trigger promastigote CP activation, but IgM addition restores C3 binding. Furthermore, Leishmania binds natural antibodies in ethylenediaminetetracetic acid (EDTA)-treated NHS; after EDTA removal, promastigote-bound IgM triggers C3 deposition in natural antibody-depleted NHS. Serum collectins and pentraxins thus do not participate significantly in NHS promastigote C3 opsonization. Real-time kinetic analysis of promastigote CP-mediated lysis indicates that between 85–95% of parasites are killed within 2.5 min of serum contact. These data indicate that successful Leishmania infection in man must immediately follow promastigote transmission, and that Leishmania evasion strategies are shaped by the selective pressure exerted by complement. PMID:11854358

Maternal and fetal alternative complement pathway activation in early severe preeclampsia.

PubMed

Hoffman, M Camille; Rumer, Kristen K; Kramer, Anita; Lynch, Anne M; Winn, Virginia D

2014-01-01

We sought to determine whether alternative complement activation fragment Bb (Bb) levels are elevated in the maternal, fetal, and placental blood in cases of severe preeclampsia (PE) compared with normotensive controls. This was a cross-sectional study of women admitted at ≥24 weeks gestation with or without severe PE. Maternal plasma was collected at the time of enrollment. Umbilical venous cord and intervillous space blood were collected at delivery. Plasma Bb levels were assessed using ELISA. Bb levels were compared between cases and controls. Median Bb levels were higher in the maternal plasma of severe PE subjects (n = 24) than in controls (n = 20), 1.45 ± 1.03 versus 0.65 ± 0.23 μg/mL, P < 0.001. In umbilical venous plasma, Bb levels were higher in severe PE subjects (n = 15) compared with controls (n = 15), 2.48 ± 1.40 versus 1.01 ± 0.57 μg/mL, P = 0.01. Activation fragment Bb is increased in the maternal and umbilical venous blood of cases of severe PE when compared with normotensive controls. These data provide support for alternative complement pathway involvement in the pathogenesis of severe PE and demonstrate that alternative complement activation occurs not only in the maternal but also in the fetal compartment. © 2013 John Wiley & Sons Ltd.

DEREGULATION OF DUX4 AND ERG IN ACUTE LYMPHOBLASTIC LEUKEMIA

PubMed Central

Zhang, Jinghui; McCastlain, Kelly; Yoshihara, Hiroki; Xu, Beisi; Chang, Yunchao; Churchman, Michelle L.; Wu, Gang; Li, Yongjin; Wei, Lei; Iacobucci, Ilaria; Liu, Yu; Qu, Chunxu; Wen, Ji; Edmonson, Michael; Payne-Turner, Debbie; Kaufmann, Kerstin B.; Takayanagi, Shin-ichiro; Wienholds, Erno; Waanders, Esmé; Ntziachristos, Panagiotis; Bakogianni, Sofia; Wang, Jingjing; Aifantis, Iannis; Roberts, Kathryn G.; Ma, Jing; Song, Guangchun; Easton, John; Mulder, Heather L.; Chen, Xiang; Newman, Scott; Ma, Xiaotu; Rusch, Michael; Gupta, Pankaj; Boggs, Kristy; Vadodaria, Bhavin; Dalton, James; Liu, Yanling; Valentine, Marcus L; Ding, Li; Lu, Charles; Fulton, Robert S.; Fulton, Lucinda; Tabib, Yashodhan; Ochoa, Kerri; Devidas, Meenakshi; Pei, Deqing; Cheng, Cheng; Yang, Jun; Evans, William E.; Relling, Mary V.; Pui, Ching-Hon; Jeha, Sima; Harvey, Richard C.; Chen, I-Ming L; Willman, Cheryl L.; Marcucci, Guido; Bloomfield, Clara D.; Kohlschmidt, Jessica; Mrózek, Krzysztof; Paietta, Elisabeth; Tallman, Martin S.; Stock, Wendy; Foster, Matthew C.; Racevskis, Janis; Rowe, Jacob M.; Luger, Selina; Kornblau, Steven M.; Shurtleff, Sheila A; Raimondi, Susana C.; Mardis, Elaine R.; Wilson, Richard K.; Dick, John E.; Hunger, Stephen P; Loh, Mignon L.; Downing, James R.; Mullighan, Charles G.

2016-01-01

Chromosomal rearrangements deregulating hematopoietic transcription factors are common in acute lymphoblastic leukemia (ALL).1,2 Here, we show that deregulation of the homeobox transcription factor gene DUX4 and the ETS transcription factor gene ERG are hallmarks of a subtype of B-progenitor ALL that comprises up to 7% of B-ALL. DUX4 rearrangement and overexpression was present in all cases, and was accompanied by transcriptional deregulation of ERG, expression of a novel ERG isoform, ERGalt, and frequent ERG deletion. ERGalt utilizes a non-canonical first exon whose transcription was initiated by DUX4 binding. ERGalt retains the DNA-binding and transactivating domains of ERG, but inhibits wild-type ERG transcriptional activity and is transforming. These results illustrate a unique paradigm of transcription factor deregulation in leukemia, in which DUX4 deregulation results in loss-of-function of ERG, either by deletion or induction of expression of an isoform that is a dominant negative inhibitor of wild type ERG function. PMID:27776115

Nine Steps to Prepare for Electricity Deregulation.

ERIC Educational Resources Information Center

Robertson, Wayne

1997-01-01

Discusses the prospects of electricity deregulation and highlights nine steps school districts can take to reassess and update their plans for maximizing the benefits of deregulation. Suggestions include forming an energy management team, seeking discounts and rate incentives, getting involved in competitive user groups, and aggressively seeking…

75 FR 68321 - Forage Genetics International; Supplemental Request for Partial Deregulation of Roundup Ready...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-05

...] Forage Genetics International; Supplemental Request for Partial Deregulation of Roundup Ready Alfalfa... Inspection Service has received a supplemental request for ``partial deregulation'' from Forage Genetics... affected persons of the availability of the documents submitted to the Agency from Forage Genetics...

Deregulation: Implications for Community College Leaders.

ERIC Educational Resources Information Center

Bender, Louis W.

1986-01-01

Looks at the ways in which the deregulation of business and industry may affect community colleges in the years ahead, using the banking industry as an illustration. Argues that the deregulation of higher education requires that community college leadership programs examine past assumptions and develop new strategies. (LAL)

Power Buying: Planning For Your Deregulated Future.

ERIC Educational Resources Information Center

Robertson, Wayne K.

1997-01-01

Colleges and universities can benefit from the coming deregulation of utilities. Deregulation creates opportunity for facility managers to aggressively negotiate agreements, implement changes to the physical plant to make the institution a more attractive customer, and explore new, less expensive energy supply options and alternatives. Some action…

Characterization of the GDP-D-mannose biosynthesis pathway in Coxiella burnetii: the initial steps for GDP-β-D-virenose biosynthesis.

PubMed

Narasaki, Craig T; Mertens, Katja; Samuel, James E

2011-01-01

Coxiella burnetii, the etiologic agent of human Q fever, is a gram-negative and naturally obligate intracellular bacterium. The O-specific polysaccharide chain (O-PS) of the lipopolysaccharide (LPS) of C. burnetii is considered a heteropolymer of the two unusual sugars β-D-virenose and dihydrohydroxystreptose and mannose. We hypothesize that GDP-D-mannose is a metabolic intermediate to GDP-β-D-virenose. GDP-D-mannose is synthesized from fructose-6-phosphate in 3 successive reactions; Isomerization to mannose-6-phosphate catalyzed by a phosphomannose isomerase (PMI), followed by conversion to mannose-1-phosphate mediated by a phosphomannomutase (PMM) and addition of GDP by a GDP-mannose pyrophosphorylase (GMP). GDP-D-mannose is then likely converted to GDP-6-deoxy-D-lyxo-hex-4-ulopyranose (GDP-Sug), a virenose intermediate, by a GDP-mannose-4,6-dehydratase (GMD). To test the validity of this pathway in C. burnetii, three open reading frames (CBU0671, CBU0294 and CBU0689) annotated as bifunctional type II PMI, as PMM or GMD were functionally characterized by complementation of corresponding E. coli mutant strains and in enzymatic assays. CBU0671, failed to complement an Escherichia coli manA (PMM) mutant strain. However, complementation of an E. coli manC (GMP) mutant strain restored capsular polysaccharide biosynthesis. CBU0294 complemented a Pseudomonas aeruginosa algC (GMP) mutant strain and showed phosphoglucomutase activity (PGM) in a pgm E. coli mutant strain. Despite the inability to complement a manA mutant, recombinant C. burnetii PMI protein showed PMM enzymatic activity in biochemical assays. CBU0689 showed dehydratase activity and determined kinetic parameters were consistent with previously reported data from other organisms. These results show the biological function of three C. burnetii LPS biosynthesis enzymes required for the formation of GDP-D-mannose and GDP-Sug. A fundamental understanding of C. burnetii genes that encode PMI, PMM and GMP is critical to fully understand the biosynthesic pathway of GDP-β-D-virenose and LPS structure in C. burnetii.

Identification of key candidate genes and pathways in hepatitis B virus-associated acute liver failure by bioinformatical analysis

PubMed Central

Lin, Huapeng; Zhang, Qian; Li, Xiaocheng; Wu, Yushen; Liu, Ye; Hu, Yingchun

2018-01-01

Abstract Hepatitis B virus-associated acute liver failure (HBV-ALF) is a rare but life-threatening syndrome that carried a high morbidity and mortality. Our study aimed to explore the possible molecular mechanisms of HBV-ALF by means of bioinformatics analysis. In this study, genes expression microarray datasets of HBV-ALF from Gene Expression Omnibus were collected, and then we identified differentially expressed genes (DEGs) by the limma package in R. After functional enrichment analysis, we constructed the protein–protein interaction (PPI) network by the Search Tool for the Retrieval of Interacting Genes online database and weighted genes coexpression network by the WGCNA package in R. Subsequently, we picked out the hub genes among the DEGs. A total of 423 DEGs with 198 upregulated genes and 225 downregulated genes were identified between HBV-ALF and normal samples. The upregulated genes were mainly enriched in immune response, and the downregulated genes were mainly enriched in complement and coagulation cascades. Orosomucoid 1 (ORM1), orosomucoid 2 (ORM2), plasminogen (PLG), and aldehyde oxidase 1 (AOX1) were picked out as the hub genes that with a high degree in both PPI network and weighted genes coexpression network. The weighted genes coexpression network analysis found out 3 of the 5 modules that upregulated genes enriched in were closely related to immune system. The downregulated genes enriched in only one module, and the genes in this module majorly enriched in the complement and coagulation cascades pathway. In conclusion, 4 genes (ORM1, ORM2, PLG, and AOX1) with immune response and the complement and coagulation cascades pathway may take part in the pathogenesis of HBV-ALF, and these candidate genes and pathways could be therapeutic targets for HBV-ALF. PMID:29384847

Cancer cell specific cytotoxic gene expression mediated by ARF tumor suppressor promoter constructs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kurayoshi, Kenta; Ozono, Eiko; Iwanaga, Ritsuko

Highlights: • ARF promoter showed higher responsiveness to deregulated E2F activity than the E2F1 promoter. • ARF promoter showed higher cancer cell-specificity than E2F1 promoter to drive gene expression. • HSV-TK driven by ARF promoter showed higher cancer cell-specific cytotoxicity than that driven by E2F1 promoter. - Abstract: In current cancer treatment protocols, such as radiation and chemotherapy, side effects on normal cells are major obstacles to radical therapy. To avoid these side effects, a cancer cell-specific approach is needed. One way to specifically target cancer cells is to utilize a cancer specific promoter to express a cytotoxic gene (suicidemore » gene therapy) or a viral gene required for viral replication (oncolytic virotherapy). For this purpose, the selected promoter should have minimal activity in normal cells to avoid side effects, and high activity in a wide variety of cancers to obtain optimal therapeutic efficacy. In contrast to the AFP, CEA and PSA promoters, which have high activity only in a limited spectrum of tumors, the E2F1 promoter exhibits high activity in wide variety of cancers. This is based on the mechanism of carcinogenesis. Defects in the RB pathway and activation of the transcription factor E2F, the main target of the RB pathway, are observed in almost all cancers. Consequently, the E2F1 promoter, which is mainly regulated by E2F, has high activity in wide variety of cancers. However, E2F is also activated by growth stimulation in normal growing cells, suggesting that the E2F1 promoter may also be highly active in normal growing cells. In contrast, we found that the tumor suppressor ARF promoter is activated by deregulated E2F activity, induced by forced inactivation of pRB, but does not respond to physiological E2F activity induced by growth stimulation. We also found that the deregulated E2F activity, which activates the ARF promoter, is detected only in cancer cell lines. These observations suggest that ARF promoter is activated by E2F only in cancer cells and therefore may be more cancer cell-specific than E2F1 promoter to drive gene expression. We show here that the ARF promoter has lower activity in normal growing fibroblasts and shows higher cancer cell-specificity compared to the E2F1 promoter. We also demonstrate that adenovirus expressing HSV-TK under the control of the ARF promoter shows lower cytotoxicity than that of the E2F1 promoter, in normal growing fibroblasts but has equivalent cytotoxicity in cancer cell lines. These results suggest that the ARF promoter, which is specifically activated by deregulated E2F activity, is an excellent candidate to drive therapeutic cytotoxic gene expression, specifically in cancer cells.« less

Effects of the Deregulation on the Concentration of the Brazilian Air Transportation Industry

NASA Technical Reports Server (NTRS)

Guterres, Marcelo Xavier; Muller, Carlos

2003-01-01

This paper addresses the effects of the deregulation of the Brazilian air transportation industry in terms of the concentration of the market. We will show some metrics that are commonly used to study the concentration of the industry. This paper uses the Herfindhal- Hirschman Index. This index tends to zero in the competitive scenario, with a large number of small firms, and to one in case of a monopolistic scenario. The paper analyses the dynamics of the concentration of the Brazilian domestic air transportation market, in order to evaluate the effects of deregulation. We conclude that the Brazilian market presents oligopoly characteristics and aspects in its current structure that maintain the market concentrated in spite of the Deregulation measures adopted by the aeronautical authority. Keywords: Herfindhal-Hirschman Index, concentration, Deregulation

Effect of deregulation on the prices of nicotine replacement therapy products in Finland.

PubMed

Aalto-Setälä, Ville; Alaranta, Antti

2008-05-01

The sales of nicotine replacement therapy (NRT) products were deregulated in Finland in February 2006. Previously all medications were sold only in pharmacies, and retail mark-ups and prices were fixed; following deregulation pricing of NRT products has been free. Further more, grocery shops, petrol stations and kiosks are now licensed to sell NRT products. The objective of this study is to evaluate the impact of deregulation on prices of NRT products. We utilized price data on NRT products (n=2106) from pharmacies, grocery shops, kiosks and petrol stations. Market prices are compared with former regulated prices, as are the prices at different types of outlets. We examined the relationship between competition and prices by regression analysis. The average price of NRT products decreased 15% after deregulation. About half of the price decrease was due to exemption of NRT products from the pharmacy fee as part of deregulation, and the other half to increased competition. The least expensive NRT products are obtainable in hypermarkets; however, pharmacies have the largest variety. Deregulation of NRT products in Finland was successful in that the prices of these products have decreased and their availability increased. Based on international experience, however, it is not clear whether these decreased prices and increased availabilities have increased smoking cessation.

Deregulation of the EGFR/PI3K/PTEN/Akt/mTORC1 pathway in breast cancer: possibilities for therapeutic intervention

PubMed Central

Davis, Nicole M.; Sokolosky, Melissa; Stadelman, Kristin; Abrams, Stephen L.; Libra, Massimo; Candido, Saverio; Nicoletti, Ferdinando; Polesel, Jerry; Maestro, Roberta; D’Assoro, Antonino; Drobot, Lyudmyla; Rakus, Dariusz; Gizak, Agnieszka; Laidler, Piotr; Dulińska-Litewka, Joanna; Basecke, Joerg; Mijatovic, Sanja; Maksimovic-Ivanic, Danijela; Montalto, Giuseppe; Cervello, Melchiorre; Fitzgerald, Timothy L.; Demidenko, Zoya N.; Martelli, Alberto M.; Cocco, Lucio; Steelman, Linda S.; McCubrey, James A.

2014-01-01

The EGFR/PI3K/PTEN/Akt/mTORC1/GSK-3 pathway plays prominent roles in malignant transformation, prevention of apoptosis, drug resistance and metastasis. The expression of this pathway is frequently altered in breast cancer due to mutations at or aberrant expression of: HER2, ERalpha, BRCA1, BRCA2, EGFR1, PIK3CA, PTEN, TP53, RB as well as other oncogenes and tumor suppressor genes. In some breast cancer cases, mutations at certain components of this pathway (e.g., PIK3CA) are associated with a better prognosis than breast cancers lacking these mutations. The expression of this pathway and upstream HER2 has been associated with breast cancer initiating cells (CICs) and in some cases resistance to treatment. The anti-diabetes drug metformin can suppress the growth of breast CICs and herceptin-resistant HER2+ cells. This review will discuss the importance of the EGFR/PI3K/PTEN/Akt/mTORC1/GSK-3 pathway primarily in breast cancer but will also include relevant examples from other cancer types. The targeting of this pathway will be discussed as well as clinical trials with novel small molecule inhibitors. The targeting of the hormone receptor, HER2 and EGFR1 in breast cancer will be reviewed in association with suppression of the EGFR/PI3K/PTEN/Akt/mTORC1/GSK-3 pathway. PMID:25051360

Deregulation of the EGFR/PI3K/PTEN/Akt/mTORC1 pathway in breast cancer: possibilities for therapeutic intervention.

PubMed

Davis, Nicole M; Sokolosky, Melissa; Stadelman, Kristin; Abrams, Steve L; Libra, Massimo; Candido, Saverio; Nicoletti, Ferdinando; Polesel, Jerry; Maestro, Roberta; D'Assoro, Antonino; Drobot, Lyudmyla; Rakus, Dariusz; Gizak, Agnieszka; Laidler, Piotr; Dulińska-Litewka, Joanna; Basecke, Joerg; Mijatovic, Sanja; Maksimovic-Ivanic, Danijela; Montalto, Giuseppe; Cervello, Melchiorre; Fitzgerald, Timothy L; Demidenko, Zoya; Martelli, Alberto M; Cocco, Lucio; Steelman, Linda S; McCubrey, James A

2014-07-15

The EGFR/PI3K/PTEN/Akt/mTORC1/GSK-3 pathway plays prominent roles in malignant transformation, prevention of apoptosis, drug resistance and metastasis. The expression of this pathway is frequently altered in breast cancer due to mutations at or aberrant expression of: HER2, ERalpha, BRCA1, BRCA2, EGFR1, PIK3CA, PTEN, TP53, RB as well as other oncogenes and tumor suppressor genes. In some breast cancer cases, mutations at certain components of this pathway (e.g., PIK3CA) are associated with a better prognosis than breast cancers lacking these mutations. The expression of this pathway and upstream HER2 has been associated with breast cancer initiating cells (CICs) and in some cases resistance to treatment. The anti-diabetes drug metformin can suppress the growth of breast CICs and herceptin-resistant HER2+ cells. This review will discuss the importance of the EGFR/PI3K/PTEN/Akt/mTORC1/GSK-3 pathway primarily in breast cancer but will also include relevant examples from other cancer types. The targeting of this pathway will be discussed as well as clinical trials with novel small molecule inhibitors. The targeting of the hormone receptor, HER2 and EGFR1 in breast cancer will be reviewed in association with suppression of the EGFR/PI3K/PTEN/Akt/mTORC1/GSK-3 pathway.

Cross-talk between estradiol receptor and EGFR/IGF-IR signaling pathways in estrogen-responsive breast cancers: focus on the role and impact of proteoglycans.

PubMed

Skandalis, Spyros S; Afratis, Nikolaos; Smirlaki, Gianna; Nikitovic, Dragana; Theocharis, Achilleas D; Tzanakakis, George N; Karamanos, Nikos K

2014-04-01

In hormone-dependent breast cancer, estrogen receptors are the principal signaling molecules that regulate several cell functions either by the genomic pathway acting directly as transcription factors in the nucleus or by the non-genomic pathway interacting with other receptors and their adjacent pathways like EGFR/IGFR. It is well established in literature that EGFR and IGFR signaling pathways promote cell proliferation and differentiation. Moreover, recent data indicate the cross-talk between ERs and EGFR/IGFR signaling pathways causing a transformation of cell functions as well as deregulation on normal expression pattern of matrix molecules. Specifically, proteoglycans, a major category of extracellular matrix (ECM) and cell surface macromolecules, are modified during malignancy and cause alterations in cancer cell signaling, affecting eventually functional cell properties such as proliferation, adhesion and migration. The on-going strategies to block only one of the above signaling effectors result cancer cells to overcome such inactivation using alternative signaling pathways. In this article, we therefore review the underlying mechanisms in respect to the role of ERs and the involvement of cross-talk between ERs, IGFR and EGFR in breast cancer cell properties and expression of extracellular secreted and cell bound proteoglycans involved in cancer progression. Understanding such signaling pathways may help to establish new potential pharmacological targets in terms of using ECM molecules to design novel anticancer therapies. © 2013. Published by Elsevier B.V. All rights reserved.

Hippo pathway regulates somatic development and cell proliferation of silkworm.

PubMed

Li, Niannian; Tong, Xiaoling; Zeng, Jie; Meng, Gang; Sun, Fuze; Hu, Hai; Song, Jiangbo; Lu, Cheng; Dai, Fangyin

2018-03-01

Hippo signaling pathway (signaling pathway Hippo, hereinafter referred to as the Hippo pathway) was the earliest found in Drosophila (Schneck [1]), which can regulate the development of tissues and organs, even some components of the pathway were identified as tumor suppressor [2]. The pathway was more concerned in fruit flies and mice (Schneck [1]), but little attention has been given in silkworm, an important economic and lepidopteran model insect. In this manuscript, we identified major Hippo pathway related genes (Hippo, Salvador, Warts, Mats, Yorkie) in silkworm and named BmHpo, BmSav, BmWts, BmMats, BmYki. The domain organization of these genes was highly conserved in silkworm and other organisms suggesting that they could use similar protein-protein interactions to construct the Hippo kinase cascades. The expression profiles of these genes in silkworm during embryonic, larval, wandering, pupal and adult stages were analyzed, 14 tissues/organs of the day 3, 5th instar larvae (L5D3) as well. Experimental results showed that the expression of Hippo pathway had some influence on the development of silkworm. In order to find out the mechanism of Hippo pathway affecting silkworm development, BmHpo and BmYki were up-regulated and de-regulated in the cell line of Bombyx mori-BmN-SWU1(NS), and the changes of cell proliferation activity and cell cycle were detected. The distribution of BmYki was detected by immunofluorescence technique. This study provides insights into the genes of Hippo pathway which have a certain effect on somatic development and cell proliferation in silkworm. Copyright © 2018 Elsevier Inc. All rights reserved.

NutrimiRAging: Micromanaging Nutrient Sensing Pathways through Nutrition to Promote Healthy Aging.

PubMed

Micó, Víctor; Berninches, Laura; Tapia, Javier; Daimiel, Lidia

2017-04-26

Current sociodemographic predictions point to a demographic shift in developed and developing countries that will result in an unprecedented increase of the elderly population. This will be accompanied by an increase in age-related conditions that will strongly impair human health and quality of life. For this reason, aging is a major concern worldwide. Healthy aging depends on a combination of individual genetic factors and external environmental factors. Diet has been proved to be a powerful tool to modulate aging and caloric restriction has emerged as a valuable intervention in this regard. However, many questions about how a controlled caloric restriction intervention affects aging-related processes are still unanswered. Nutrient sensing pathways become deregulated with age and lose effectiveness with age. These pathways are a link between diet and aging. Thus, fully understanding this link is a mandatory step before bringing caloric restriction into practice. MicroRNAs have emerged as important regulators of cellular functions and can be modified by diet. Some microRNAs target genes encoding proteins and enzymes belonging to the nutrient sensing pathways and, therefore, may play key roles in the modulation of the aging process. In this review, we aimed to show the relationship between diet, nutrient sensing pathways and microRNAs in the context of aging.

Nrf2-p62 autophagy pathway and its response to oxidative stress in hepatocellular carcinoma.

PubMed

Bartolini, Desirée; Dallaglio, Katiuscia; Torquato, Pierangelo; Piroddi, Marta; Galli, Francesco

2018-03-01

Deregulation of autophagy is proposed to play a key pathogenic role in hepatocellular carcinoma (HCC), the most common primary malignancy of the liver and the third leading cause of cancer death. Autophagy is an evolutionarily conserved catabolic process activated to degrade and recycle cell's components. Under stress conditions, such as oxidative stress and nutrient deprivation, autophagy is an essential survival pathway that operates in harmony with other stress response pathways. These include the redox-sensitive transcription complex Nrf2-Keap1 that controls groups of genes with roles in detoxification and antioxidant processes, intermediary metabolism, and cell cycle regulation. Recently, a functional association between a dysfunctional autophagy and Nrf2 pathway activation has been identified in HCC. This appears to occur through the physical interaction of the autophagy adaptor p62 with the Nrf2 inhibitor Keap1, thus leading to increased stabilization and transcriptional activity of Nrf2, a key event in reprogramming metabolic and stress response pathways of proliferating hepatocarcinoma cells. These emerging molecular mechanisms and the therapeutic perspective of targeting Nrf2-p62 interaction in HCC are discussed in this paper along with the prognostic value of autophagy in this type of cancer. Copyright © 2017 Elsevier Inc. All rights reserved.

PI3K/Akt/mTOR Intracellular Pathway and Breast Cancer: Factors, Mechanism and Regulation.

PubMed

Sharma, Var Ruchi; Gupta, Girish Kumar; Sharma, A K; Batra, Navneet; Sharma, Daljit K; Joshi, Amit; Sharma, Anil K

2017-01-01

The most recurrent and considered second most frequent cause of cancer-related deaths worldwide in women is the breast cancer. The key to diagnosis is early prediction and a curable stage but still treatment remains a great clinical challenge. Origin of the Problem: A number of studies have been carried out for the treatment of breast cancer which includes the targeted therapies and increased survival rates in women. Essential PI3K/mTOR signaling pathway activation has been observed in most breast cancers. The cell growth and tumor development in such cases involve phosphoinositide 3 kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) complex intracellular pathway. Through preclinical and clinical trials, it has been observed that there are a number of other inhibitors of PI3K/Akt/mTOR pathway, which either alone or in combination with cytotoxic agents can be used for endocrine therapies. Structure and regulation/deregulation of mTOR provides a greater insight into the action mechanism. Also, through this review, one could easily scan first and second generation inhibitors for PI3K/Akt/mTOR pathway besides targeted therapies for breast cancer and the precise role of mTOR. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

GLI1 inhibition promotes epithelial-to-mesenchymal transition in pancreatic cancer cells

PubMed Central

Joost, Simon; Almada, Luciana L.; Rohnalter, Verena; Holz, Philipp S.; Vrabel, Anne M.; Fernandez-Barrena, Maite G.; McWilliams, Robert R.; Krause, Michael; Fernandez-Zapico, Martin E.; Lauth, Matthias

2011-01-01

The Hedgehog (HH) pathway has been identified as an important deregulated signal transduction pathway in pancreatic ductal adenocarcinoma (PDAC), a cancer type characterized by a highly metastatic phenotype. In PDAC, the canonical HH pathway activity is restricted to the stromal compartment while HH signaling in the tumor cells is reduced as a consequence of constitutive KRAS activation. Here we report that in the tumor compartment of PDAC the HH pathway effector transcription factor GLI1 regulates epithelial differentiation. RNAi-mediated knockdown of GLI1 abolished characteristics of epithelial differentiation, increased cell motility and synergized with TGFβ to induce an epithelial-to-mesenchymal transition (EMT). Notably, EMT conversion in PDAC cells occurred in the absence of induction of SNAIL or SLUG, two canonical inducers of EMT in many other settings. Further mechanistic analysis revealed that GLI1 directly regulated the transcription of E-cadherin, a key determinant of epithelial tissue organization. Collectively, our findings identify GLI1 as an important positive regulator of epithelial differentiation, and they offer an explanation for how decreased levels of GLI1 are likely to contribute to the highly metastatic phenotype of PDAC. PMID:22086851

Aging: Molecular Pathways and Implications on the Cardiovascular System

PubMed Central

Ribeiro, Thaís Porto

2017-01-01

The world's population over 60 years is growing rapidly, reaching 22% of the global population in the next decades. Despite the increase in global longevity, individual healthspan needs to follow this growth. Several diseases have their prevalence increased by age, such as cardiovascular diseases, the leading cause of morbidity and mortality worldwide. Understanding the aging biology mechanisms is fundamental to the pursuit of cardiovascular health. In this way, aging is characterized by a gradual decline in physiological functions, involving the increased number in senescent cells into the body. Several pathways lead to senescence, including oxidative stress and persistent inflammation, as well as energy failure such as mitochondrial dysfunction and deregulated autophagy, being ROS, AMPK, SIRTs, mTOR, IGF-1, and p53 key regulators of the metabolic control, connecting aging to the pathways which drive towards diseases. In addition, senescence can be induced by cellular replication, which resulted from telomere shortening. Taken together, it is possible to draw a common pathway unifying aging to cardiovascular diseases, and the central point of this process, senescence, can be the target for new therapies, which may result in the healthspan matching the lifespan. PMID:28874954

The Hippo Pathway as Drug Targets in Cancer Therapy and Regenerative Medicine.

PubMed

Nagashima, Shunta; Bao, Yijun; Hata, Yutaka

2017-01-01

Yes-associated protein 1 (YAP1) and transcriptional co-activator with PDZ-binding motif (TAZ) co-operate with numerous transcription factors to regulate gene transcriptions. YAP1 and TAZ are negatively regulated by the tumor suppressive Hippo pathway. In human cancers, the Hippo pathway is frequently deregulated and YAP1 and TAZ escape the inhibition by the Hippo pathway. The upregulation of YAP1 and TAZ induces epithelial-mesenchymal transition and increases drug resistance in cancer cells. TAZ is implicated in cancer stemness. In consequence cancers with hyperactive YAP1 and TAZ are associated with poor clinical prognosis. Inhibitors of YAP1 and TAZ are reasoned to be beneficial in cancer therapy. On the other hand, since YAP1 and TAZ play important roles in the regulation of various tissue stem cells and in tissue repair, activators of YAP1 and TAZ are useful in the regenerative medicine. We discuss the potential application of inhibitors and activators of YAP1 and TAZ in human diseases and review the progress of drug screenings to search for them. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Crocodile choline from Crocodylus siamensis induces apoptosis of human gastric cancer.

PubMed

Mao, Xiao-Mei; Fu, Qi-Rui; Li, Hua-Liang; Zheng, Ya-Hui; Chen, Shu-Ming; Hu, Xin-Yi; Chen, Qing-Xi; Chen, Qiong-Hua

2017-03-01

Crocodile choline, an active compound isolated from Crocodylus siamensis, was found to exert potent anti-cancer activities against human gastric cancer cells in vitro and in vivo. Our study revealed that crocodile choline led to cell cycle arrest at the G2/M phase through attenuating the expressions of cyclins, Cyclin B1, and CDK-1. Furthermore, crocodile choline accelerated apoptosis through the mitochondrial apoptotic pathway with the decrease in mitochondrial membrane potential, the increase in reactive oxygen species production and Bax/Bcl-2 ratio, and the activation of caspase-3 along with the release of cytochrome c. In addition, this study, for the first time, shows that Notch pathway is remarkably deregulated by crocodile choline. The combination of crocodile choline and Notch1 short interfering RNA led to dramatically increased cytotoxicity than observed with either agent alone. Notch1 short interfering RNA sensitized and potentiated the capability of crocodile choline to suppress the cell progression and invasion of gastric cancer. Taken together, these data suggested that crocodile choline was a potent progression inhibitor of gastric cancer cells, which was correlated with mitochondrial apoptotic pathway and Notch pathway. Combining Notch1 inhibitors with crocodile choline might represent a novel approach for gastric cancer.

Gene expression profiles in liver of mouse after chronic exposure to drinking water.

PubMed

Wu, Bing; Zhang, Yan; Zhao, Dayong; Zhang, Xuxiang; Kong, Zhiming; Cheng, Shupei

2009-10-01

cDNA micorarray approach was applied to hepatic transcriptional profile analysis in male mouse (Mus musculus, ICR) to assess the potential health effects of drinking water in Nanjing, China. Mice were treated with continuous exposure to drinking water for 90 days. Hepatic gene expression was analyzed with Affymetrix Mouse Genome 430A 2.0 arrays, and pathway analysis was carried out by Molecule Annotation System 2.0 and KEGG pathway database. A total of 836 genes were found to be significantly altered (1.5-fold, P < or = 0.05), including 294 up-regulated genes and 542 down-regulated genes. According to biological pathway analysis, drinking water exposure resulted in aberration of gene expression and biological pathways linked to xenobiotic metabolism, signal transduction, cell cycle and oxidative stress response. Further, deregulation of several genes associated with carcinogenesis or tumor progression including Ccnd1, Egfr, Map2k3, Mcm2, Orc2l and Smad2 was observed. Although transcription changes in identified genes are unlikely to be used as a sole indicator of adverse health effects, the results of this study could enhance our understanding of early toxic effects of drinking water exposure and support future studies on drinking water safety.

Potassium Channels in Peripheral Pain Pathways: Expression, Function and Therapeutic Potential

PubMed Central

Du, Xiaona; Gamper, Nikita

2013-01-01

Electrical excitation of peripheral somatosensory nerves is a first step in generation of most pain signals in mammalian nervous system. Such excitation is controlled by an intricate set of ion channels that are coordinated to produce a degree of excitation that is proportional to the strength of the external stimulation. However, in many disease states this coordination is disrupted resulting in deregulated peripheral excitability which, in turn, may underpin pathological pain states (i.e. migraine, neuralgia, neuropathic and inflammatory pains). One of the major groups of ion channels that are essential for controlling neuronal excitability is potassium channel family and, hereby, the focus of this review is on the K+ channels in peripheral pain pathways. The aim of the review is threefold. First, we will discuss current evidence for the expression and functional role of various K+ channels in peripheral nociceptive fibres. Second, we will consider a hypothesis suggesting that reduced functional activity of K+ channels within peripheral nociceptive pathways is a general feature of many types of pain. Third, we will evaluate the perspectives of pharmacological enhancement of K+ channels in nociceptive pathways as a strategy for new analgesic drug design. PMID:24396338

Crosstalk Between Apoptosis and Autophagy: Environmental Genotoxins, Infection, and Innate Immunity.

PubMed

Kemp, Michael G

2017-01-01

Autoimmune disorders constitute a major and growing health concern. However, the genetic and environmental factors that contribute to or exacerbate disease symptoms remain unclear. Type I interferons (IFNs) are known to break immune tolerance and be elevated in the serum of patients with autoimmune diseases such as lupus. Extensive work over the past decade has characterized the role of a protein termed stimulator of interferon genes, or STING, in mediating IFN expression and activation in response to cytosolic DNA and cyclic dinucleotides. Interestingly, this STING-dependent innate immune pathway both utilizes and is targeted by the cell's autophagic machinery. Given that aberrant interplay between the apoptotic and autophagic machineries contributes to deregulation of the STING-dependent pathway, IFN-regulated autoimmune phenotypes may be influenced by the combined exposure to environmental carcinogens and pathogenic microorganisms and viruses. This review therefore summarizes recent data regarding these important issues in the field of autoimmunity.

Epstein-Barr Virus Hijacks DNA Damage Response Transducers to Orchestrate Its Life Cycle.

PubMed

Hau, Pok Man; Tsao, Sai Wah

2017-11-16

The Epstein-Barr virus (EBV) is a ubiquitous virus that infects most of the human population. EBV infection is associated with multiple human cancers, including Burkitt's lymphoma, Hodgkin's lymphoma, a subset of gastric carcinomas, and almost all undifferentiated non-keratinizing nasopharyngeal carcinoma. Intensive research has shown that EBV triggers a DNA damage response (DDR) during primary infection and lytic reactivation. The EBV-encoded viral proteins have been implicated in deregulating the DDR signaling pathways. The consequences of DDR inactivation lead to genomic instability and promote cellular transformation. This review summarizes the current understanding of the relationship between EBV infection and the DDR transducers, including ATM (ataxia telangiectasia mutated), ATR (ATM and Rad3-related), and DNA-PK (DNA-dependent protein kinase), and discusses how EBV manipulates the DDR signaling pathways to complete the replication process of viral DNA during lytic reactivation.

Integrative Analysis Reveals an Outcome-associated and Targetable Pattern of p53 and Cell Cycle Deregulation in Diffuse Large B-cell Lymphoma

PubMed Central

Monti, Stefano; Chapuy, Bjoern; Takeyama, Kunihiko; Rodig, Scott J; Hao, Yangsheng; Yeda, Kelly T.; Inguilizian, Haig; Mermel, Craig; Curie, Treeve; Dogan, Ahmed; Kutok, Jeffery L; Beroukim, Rameen; Neuberg, Donna; Habermann, Thomas; Getz, Gad; Kung, Andrew L; Golub, Todd R; Shipp, Margaret A

2013-01-01

Summary Diffuse large B-cell lymphoma (DLBCL) is a clinically and biologically heterogeneous disease with a high proliferation rate. By integrating copy number data with transcriptional profiles and performing pathway analysis in primary DLBCLs, we identified a comprehensive set of copy number alterations (CNAs) that decreased p53 activity and perturbed cell cycle regulation. Primary tumors either had multiple complementary alterations of p53 and cell cycle components or largely lacked these lesions. DLBCLs with p53 and cell cycle pathway CNAs had decreased abundance of p53 target transcripts and increased expression of E2F target genes and the Ki67 proliferation marker. CNAs of the CDKN2A-TP53-RB-E2F axis provide a structural basis for increased proliferation in DLBCL, predict outcome with current therapy and suggest targeted treatment approaches. PMID:22975378

Anticancer molecules targeting fibroblast growth factor receptors.

PubMed

Liang, Guang; Liu, Zhiguo; Wu, Jianzhang; Cai, Yuepiao; Li, Xiaokun

2012-10-01

The fibroblast growth factor receptor (FGFR) family includes four highly conserved receptor tyrosine kinases: FGFR1-4. Upon ligand binding, FGFRs activate an array of downstream signaling pathways, such as the mitogen activated protein kinase (MAPK) and the phosphoinositide-3-kinase (PI3K)/Akt pathways. These FGFR cascades play crucial roles in tumor cell proliferation, angiogenesis, migration, and survival. The combination of knockdown studies and pharmaceutical inhibition in preclinical models demonstrates that FGFRs are attractive targets for therapeutic intervention in cancer. Multiple FGFR inhibitors with various structural skeletons have been designed, synthesized, and evaluated. Reviews on FGFRs have recently focused on FGFR signaling, pathophysiology, and functions in cancer or other diseases. In this article, we review recent advances in structure-activity relationships (SAR) of FGFR inhibitors, as well as the FGFR-targeting drug design strategies currently employed in targeting deregulated FGFRs by antibodies and small molecule inhibitors. Copyright © 2012 Elsevier Ltd. All rights reserved.

Molecular Insights on Post-chemotherapy Retinoblastoma by Microarray Gene Expression Analysis

PubMed Central

Nalini, Venkatesan; Segu, Ramya; Deepa, Perinkulam Ravi; Khetan, Vikas; Vasudevan, Madavan; Krishnakumar, Subramanian

2013-01-01

Purpose Management of Retinoblastoma (RB), a pediatric ocular cancer is limited by drug-resistance and drug-dosage related side effects during chemotherapy. Molecular de-regulation in post-chemotherapy RB tumors was investigated. Materials and Methods cDNA microarray analysis of two post-chemotherapy and one pre-chemotherapy RB tumor tissues was performed, followed by Principle Component Analysis, Gene ontology, Pathway Enrichment analysis and Biological Analysis Network (BAN) modeling. The drug modulation role of two significantly up-regulated genes (p≤0.05) − Ect2 (Epithelial-cell-transforming-sequence-2), and PRAME (preferentially-expressed-Antigen-in-Melanoma) was assessed by qRT-PCR, immunohistochemistry and cell viability assays. Results Differential up-regulation of 1672 genes and down-regulation of 2538 genes was observed in RB tissues (relative to normal adult retina), while 1419 genes were commonly de-regulated between pre-chemotherapy and post- chemotherapy RB. Twenty one key gene ontology categories, pathways, biomarkers and phenotype groups harboring 250 differentially expressed genes were dys-regulated (EZH2, NCoR1, MYBL2, RB1, STAMN1, SYK, JAK1/2, STAT1/2, PLK2/4, BIRC5, LAMN1, Ect2, PRAME and ABCC4). Differential molecular expressions of PRAME and Ect2 in RB tumors with and without chemotherapy were analyzed. There was neither up- regulation of MRP1, nor any significant shift in chemotherapeutic IC50, in PRAME over-expressed versus non-transfected RB cells. Conclusion Cell cycle regulatory genes were dys-regulated post-chemotherapy. Ect2 gene was expressed in response to chemotherapy-induced stress. PRAME does not contribute to drug resistance in RB, yet its nuclear localization and BAN information, points to its possible regulatory role in RB. PMID:24092970

Friend spleen focus-forming virus transforms rodent fibroblasts in cooperation with a short form of the receptor tyrosine kinase Stk

PubMed Central

Nishigaki, Kazuo; Hanson, Charlotte; Jelacic, Tanya; Thompson, Delores; Ruscetti, Sandra

2005-01-01

Friend spleen focus-forming virus (SFFV) causes rapid erythroleukemia in mice due to expression of its unique envelope glycoprotein, gp55. Erythroid cells expressing SFFV gp55 proliferate in the absence of their normal regulator erythropoietin (Epo) because of constitutive activation of Epo signal transduction pathways. Although SFFV infects many cell types, deregulation of cell growth occurs only when SFFV infects erythroid cells, suggesting that these cells express unique proteins that the virus requires to mediate its biological effects. Not only do erythroid cells express the Epo receptor (EpoR), but those from mice susceptible to SFFV-induced erythroleukemia also express a short form of the receptor tyrosine kinase Stk (sf-Stk). In erythroid cells, SFFV gp55 interacts with the EpoR complex and sf-Stk, leading to activation of the kinase and constitutive activation of signal transducing molecules. In this study, we demonstrate that SFFV gp55 can also deregulate the growth of nonerythroid cells when it is coexpressed with sf-Stk. Expression of SFFV gp55 in rodent fibroblasts engineered to express sf-Stk induced their transformation, as demonstrated by focus formation and anchorage-independent growth in vitro. This transformation by SFFV gp55 requires the kinase activity of sf-Stk and the presence of its extracellular domain but not expression of the EpoR or the tyrosine kinase Jak2, which is required for activation of signal transduction pathways through the EpoR. Thus, expression of SFFV gp55 in nonerythroid cells coexpressing sf-Stk results in their uncontrolled growth, demonstrating a previously unrecognized mechanism for retrovirus transformation of rodent fibroblasts and providing insight into SFFV-induced disease. PMID:16223879

Revealing the Molecular Portrait of Triple Negative Breast Tumors in an Understudied Population through Omics Analysis of Formalin-Fixed and Paraffin-Embedded Tissues

PubMed Central

Vaca-Paniagua, Felipe; Alvarez-Gomez, Rosa María; Maldonado-Martínez, Hector Aquiles; Pérez-Plasencia, Carlos; Fragoso-Ontiveros, Veronica; Lasa-Gonsebatt, Federico; Herrera, Luis Alonso; Cantú, David; Bargallo-Rocha, Enrique; Mohar, Alejandro; Durand, Geoffroy; Forey, Nathalie; Voegele, Catherine; Vallée, Maxime; Le Calvez-Kelm, Florence; McKay, James; Ardin, Maude; Villar, Stéphanie; Zavadil, Jiri; Olivier, Magali

2015-01-01

Triple negative breast cancer (TNBC), defined by the lack of expression of the estrogen receptor, progesterone receptor and human epidermal receptor 2, is an aggressive form of breast cancer that is more prevalent in certain populations, in particular in low- and middle-income regions. The detailed molecular features of TNBC in these regions remain unexplored as samples are mostly accessible as formalin-fixed paraffin embedded (FFPE) archived tissues, a challenging material for advanced genomic and transcriptomic studies. Using dedicated reagents and analysis pipelines, we performed whole exome sequencing and miRNA and mRNA profiling of 12 FFPE tumor tissues collected from pathological archives in Mexico. Sequencing analyses of the tumor tissues and their blood pairs identified TP53 and RB1 genes as the most frequently mutated genes, with a somatic mutation load of 1.7 mutations/exome Mb on average. Transcriptional analyses revealed an overexpression of growth-promoting signals (EGFR, PDGFR, VEGF, PIK3CA, FOXM1), a repression of cell cycle control pathways (TP53, RB1), a deregulation of DNA-repair pathways, and alterations in epigenetic modifiers through miRNA:mRNA network de-regulation. The molecular programs identified were typical of those described in basal-like tumors in other populations. This work demonstrates the feasibility of using archived clinical samples for advanced integrated genomics analyses. It thus opens up opportunities for investigating molecular features of tumors from regions where only FFPE tissues are available, allowing retrospective studies on the search for treatment strategies or on the exploration of the geographic diversity of breast cancer. PMID:25961742

Complement Activation: An Emerging Player in the Pathogenesis of Cardiovascular Disease

PubMed Central

Carter, Angela M.

2012-01-01

A wealth of evidence indicates a fundamental role for inflammation in the pathogenesis of cardiovascular disease (CVD), contributing to the development and progression of atherosclerotic lesion formation, plaque rupture, and thrombosis. An increasing body of evidence supports a functional role for complement activation in the pathogenesis of CVD through pleiotropic effects on endothelial and haematopoietic cell function and haemostasis. Prospective and case control studies have reported strong relationships between several complement components and cardiovascular outcomes, and in vitro studies and animal models support a functional effect. Complement activation, in particular, generation of C5a and C5b-9, influences many processes involved in the development and progression of atherosclerosis, including promotion of endothelial cell activation, leukocyte infiltration into the extracellular matrix, stimulation of cytokine release from vascular smooth muscle cells, and promotion of plaque rupture. Complement activation also influences thrombosis, involving components of the mannose-binding lectin pathway, and C5b-9 in particular, through activation of platelets, promotion of fibrin formation, and impairment of fibrinolysis. The participation of the complement system in inflammation and thrombosis is consistent with the physiological role of the complement system as a rapid effector system conferring protection following vessel injury. However, in the context of CVD, these same processes contribute to development of atherosclerosis, plaque rupture, and thrombosis. PMID:24278688

Dealing with failed deregulation: what would price c. Watts do?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rothkopf, Michael H.

2007-08-15

There has been much thought given to ways that might fix deregulated markets, and there is still no agreement on the correct fix. The once-pseudonymous Price C. Watts thinks it is time to think seriously about ways to reregulate where deregulation has failed. Here are some steps to get us there. (author)

Complement in Action: An Analysis of Patent Trends from 1976 Through 2011.

PubMed

Yang, Kun; Deangelis, Robert A; Reed, Janet E; Ricklin, Daniel; Lambris, John D

2013-01-01

Complement is an essential part of the innate immune response. It interacts with diverse endogenous pathways and contributes to the maintenance of homeostasis, the modulation of adaptive immune responses, and the development of various pathologies. The potential usefulness, in both research and clinical settings, of compounds that detect or modulate complement activity has resulted in thousands of publications on complement-related innovations in fields such as drug discovery, disease diagnosis and treatment, and immunoassays, among others. This study highlights the distribution and publication trends of patents related to the complement system that were granted by the United States Patent and Trademark Office from 1976 to the present day. A comparison to complement-related documents published by the World Intellectual Property Organization is also included. Statistical analyses revealed increasing diversity in complement-related research interests over time. More than half of the patents were found to focus on the discovery of inhibitors; interest in various inhibitor classes exhibited a remarkable transformation from chemical compounds early on to proteins and antibodies in more recent years. Among clinical applications, complement proteins and their modulators have been extensively patented for the diagnosis and treatment of eye diseases (especially age-related macular degeneration), graft rejection, cancer, sepsis, and a variety of other inflammatory and immune diseases. All of the patents discussed in this chapter, as well as those from other databases, are available from our newly constructed complement patent database: www.innateimmunity.us/patent .

Complement in action: an analysis of patent trends from 1976 through 2011.

PubMed

Yang, Kun; DeAngelis, Robert A; Reed, Janet E; Ricklin, Daniel; Lambris, John D

2013-01-01

Complement is an essential part of the innate immune response. It interacts with diverse endogenous pathways and contributes to the maintenance of homeostasis, the modulation of adaptive immune responses, and the development of various pathologies. The potential usefulness, in both research and clinical settings, of compounds that detect or modulate complement activity has resulted in thousands of publications on complement-related innovations in fields such as drug discovery, disease diagnosis and treatment, and immunoassays, among others. This study highlights the distribution and publication trends of patents related to the complement system that were granted by the United States Patent and Trademark Office from 1976 to the present day. A comparison to complement-related documents published by the World Intellectual Property Organization is also included. Statistical analyses revealed increasing diversity in complement-related research interests over time. More than half of the patents were found to focus on the discovery of inhibitors; interest in various inhibitor classes exhibited a remarkable transformation from chemical compounds early on to proteins and antibodies in more recent years. Among clinical applications, complement proteins and their modulators have been extensively patented for the diagnosis and treatment of eye diseases (especially age-related macular degeneration), graft rejection, cancer, sepsis, and a variety of other inflammatory and immune diseases. All of the patents discussed in this chapter, as well as those from other databases, are available from our newly constructed complement patent database: www.innateimmunity.us/patent.

A zebrafish model for uremic toxicity: role of the complement pathway.

PubMed

Berman, Nathaniel; Lectura, Melisa; Thurman, Josh; Reinecke, James; Raff, Amanda C; Melamed, Michal L; Reinecke, James; Quan, Zhe; Evans, Todd; Meyer, Timothy W; Hostetter, Thomas H

2013-01-01

Many organic solutes accumulate in end-stage renal disease (ESRD) and some are poorly removed with urea-based prescriptions for hemodialysis. However, their toxicities have been difficult to assess. We have employed an animal model, the zebrafish embryo, to test the toxicity of uremic serum compared to control. Serum was obtained from stable ESRD patients predialysis or from normal subjects. Zebrafish embryos 24 h postfertilization were exposed to experimental media at a water:human serum ratio of 3:1. Those exposed to serum from uremic subjects had significantly reduced survival at 8 h (19 ± 18 vs. 94 ± 6%, p < 0.05, uremic serum vs. control, respectively). Embryos exposed to serum from ESRD subjects fractionated at 50 kDa showed significantly greater toxicity with the larger molecular weight fraction (83 ± 11 vs. 7 ± 17% survival, p < 0.05, <50 vs. >50 kDa, respectively). Heating serum abrogated its toxicity. EDTA, a potent inhibitor of complement by virtue of calcium chelation, reduced the toxicity of uremic serum compared to untreated uremic serum (96 ± 5 vs. 28 ± 20% survival, p < 0.016, chelated vs. nonchelated serum, respectively). Anti-factor B, a specific inhibitor of the alternative complement pathway, reduced the toxicity of uremic serum, compared to untreated uremic serum (98 ± 6 vs. 3 ± 9% survival, p < 0.016, anti-factor B treated vs. nontreated, respectively). Uremic serum is thus more toxic to zebrafish embryos than normal serum. Furthermore, this toxicity is associated with a fraction of large size, is inactivated by heat, and is reduced by both specific and nonspecific inhibitors of complement activation. Together these data lend support to the hypothesis that at least some uremic toxicities may be mediated by complement. Copyright © 2013 S. Karger AG, Basel.

A Zebrafish Model for Uremic Toxicity: Role of the Complement Pathway

PubMed Central

Thurman, Josh; Reinecke, James; Raff, Amanda C.; Melamed, Michal L.; Reinecke, James; Quan, Zhe; Evans, Todd; Meyer, Timothy W.; Hostetter, Thomas H

2016-01-01

Many organic solutes accumulate in ESRD and some are poorly removed removed with urea based prescriptions for hemodialysis. However, their toxicities have been difficult to assess. We have employed an animal model, the zebrafish embryo, to test the toxicity of uremic serum compared to control. Serum was obtained from stable ESRD patients pre-dialysis or from normal subjects. Zebrafish embryos 24 hours post fertilization were exposed to experimental media at a ratio of 3:1 water:human serum. Those exposed to serum from uremic subjects had significantly reduced survival at 8 hours (19% +/− 18% vs. 94% +/− 6%; p < 0.05, uremic serum vs control, respectively). Embryos exposed to serum from ESRD subjects fractionated at 50kD showed significantly greater toxicity with the larger molecular weight fraction (83% +/− 11% vs 7% +/−17% survival, p < 0.05, <50kD vs >50 kD, respectively). Heating serum abrogated its toxicity. EDTA, a potent inhibitor of complement by virtue of calcium chelation, reduced the toxicity of uremic serum compared to untreated uremic serum (96%+/− 5% vs 28%+/− 20% survival, p < 0.016, chelated vs non chelated serum respectively). Anti- factor B, a specific inhibitor of the alternative complement pathway, reduced the toxicity of uremic serum, compared to untreated uremic serum (98% +/− 6% vs. 3% +/− 9% survival, p < 0.016, anti- factor B treated vs non treated, respectively).Uremic serum is thus more toxic to zebrafish embryos than normal serum. Furthermore, this toxicity is associated with a fraction of large size, is inactivated by heat, and is reduced by both specific and non-specific inhibitors of complement activation. Together these data lend support to the hypothesis that at least some uremic toxicities may be mediated by complement. PMID:23689420

Binding of Soluble Yeast β-Glucan to Human Neutrophils and Monocytes is Complement-Dependent

PubMed Central

Bose, Nandita; Chan, Anissa S. H.; Guerrero, Faimola; Maristany, Carolyn M.; Qiu, Xiaohong; Walsh, Richard M.; Ertelt, Kathleen E.; Jonas, Adria Bykowski; Gorden, Keith B.; Dudney, Christine M.; Wurst, Lindsay R.; Danielson, Michael E.; Elmasry, Natalie; Magee, Andrew S.; Patchen, Myra L.; Vasilakos, John P.

2013-01-01

The immunomodulatory properties of yeast β-1,3/1,6 glucans are mediated through their ability to be recognized by human innate immune cells. While several studies have investigated binding of opsonized and unopsonized particulate β-glucans to human immune cells mainly via complement receptor 3 (CR3) or Dectin-1, few have focused on understanding the binding characteristics of soluble β-glucans. Using a well-characterized, pharmaceutical-grade, soluble yeast β-glucan, this study evaluated and characterized the binding of soluble β-glucan to human neutrophils and monocytes. The results demonstrated that soluble β-glucan bound to both human neutrophils and monocytes in a concentration-dependent and receptor-specific manner. Antibodies blocking the CD11b and CD18 chains of CR3 significantly inhibited binding to both cell types, establishing CR3 as the key receptor recognizing the soluble β-glucan in these cells. Binding of soluble β-glucan to human neutrophils and monocytes required serum and was also dependent on incubation time and temperature, strongly suggesting that binding was complement-mediated. Indeed, binding was reduced in heat-inactivated serum, or in serum treated with methylamine or in serum reacted with the C3-specific inhibitor compstatin. Opsonization of soluble β-glucan was demonstrated by detection of iC3b, the complement opsonin on β-glucan-bound cells, as well as by the direct binding of iC3b to β-glucan in the absence of cells. Binding of β-glucan to cells was partially inhibited by blockade of the alternative pathway of complement, suggesting that the C3 activation amplification step mediated by this pathway also contributed to binding. PMID:23964276

Complement Factor H Is Expressed in Adipose Tissue in Association With Insulin Resistance

PubMed Central

Moreno-Navarrete, José María; Martínez-Barricarte, Rubén; Catalán, Victoria; Sabater, Mònica; Gómez-Ambrosi, Javier; Ortega, Francisco José; Ricart, Wifredo; Blüher, Mathias; Frühbeck, Gema; Rodríguez de Cordoba, Santiago; Fernández-Real, José Manuel

2010-01-01

OBJECTIVE Activation of the alternative pathway of the complement system, in which factor H (fH; complement fH [CFH]) is a key regulatory component, has been suggested as a link between obesity and metabolic disorders. Our objective was to study the associations between circulating and adipose tissue gene expressions of CFH and complement factor B (fB; CFB) with obesity and insulin resistance. RESEARCH DESIGN AND METHODS Circulating fH and fB were determined by enzyme-linked immunosorbent assay in 398 subjects. CFH and CFB gene expressions were evaluated in 76 adipose tissue samples, in isolated adipocytes, and in stromovascular cells (SVC) (n = 13). The effects of weight loss and rosiglitazone were investigated in independent cohorts. RESULTS Both circulating fH and fB were associated positively with BMI, waist circumference, triglycerides, and inflammatory parameters and negatively with insulin sensitivity and HDL cholesterol. For the first time, CFH gene expression was detected in human adipose tissue (significantly increased in subcutaneous compared with omental fat). CFH gene expression in omental fat was significantly associated with insulin resistance. In contrast, CFB gene expression was significantly increased in omental fat but also in association with fasting glucose and triglycerides. The SVC fraction was responsible for these differences, although isolated adipocytes also expressed fB and fH at low levels. Both weight loss and rosiglitazone led to significantly decreased circulating fB and fH levels. CONCLUSIONS Increased circulating fH and fB concentrations in subjects with altered glucose tolerance could reflect increased SVC-induced activation of the alternative pathway of complement in omental adipose tissue linked to insulin resistance and metabolic disturbances. PMID:19833879

Future perspectives in target-specific immunotherapies of myasthenia gravis

PubMed Central

Dalakas, Marinos C.

2015-01-01

Myasthenia gravis (MG) is an autoimmune disease caused by complement-fixing antibodies against acetylcholine receptors (AChR); antigen-specific CD4+ T cells, regulatory T cells (Tregs) and T helper (Th) 17+ cells are essential in antibody production. Target-specific therapeutic interventions should therefore be directed against antibodies, B cells, complement and molecules associated with T cell signaling. Even though the progress in the immunopathogenesis of the disease probably exceeds any other autoimmune disorder, MG is still treated with traditional drugs or procedures that exert a non-antigen specific immunosuppression or immunomodulation. Novel biological agents currently on the market, directed against the following molecular pathways, are relevant and specific therapeutic targets that can be tested in MG: (a) T cell intracellular signaling molecules, such as anti-CD52, anti-interleukin (IL) 2 receptors, anti- costimulatory molecules, and anti-Janus tyrosine kinases (JAK1, JAK3) that block the intracellular cascade associated with T-cell activation; (b) B cells and their trophic factors, directed against key B-cell molecules; (c) complement C3 or C5, intercepting the destructive effect of complement-fixing antibodies; (d) cytokines and cytokine receptors, such as those targeting IL-6 which promotes antibody production and IL-17, or the p40 subunit of IL-12/1L-23 that affect regulatory T cells; and (e) T and B cell transmigration molecules associated with lymphocyte egress from the lymphoid organs. All drugs against these molecular pathways require testing in controlled trials, although some have already been tried in small case series. Construction of recombinant AChR antibodies that block binding of the pathogenic antibodies, thereby eliminating complement and antibody-depended-cell-mediated cytotoxicity, are additional novel molecular tools that require exploration in experimental MG. PMID:26600875

Germline Variation in Complement Genes and Event-Free Survival in Follicular and Diffuse Large B-Cell Lymphoma

PubMed Central

Charbonneau, Bridget; Maurer, Matthew J.; Fredericksen, Zachary S.; Zent, Clive S.; Link, Brian K.; Novak, Anne J.; Ansell, Stephen M.; Weiner, George J.; Wang, Alice H.; Witzig, Thomas E.; Dogan, Ahmet; Slager, Susan L.; Habermann, Thomas M.; Cerhan, James R.

2013-01-01

The complement pathway plays a central role in innate immunity, and also functions as a regulator of the overall immune response. We evaluated whether polymorphisms in complement genes are associated with event-free survival (EFS) in follicular (FL) and diffuse large B-cell (DLBCL) lymphoma. We genotyped 167 single nucleotide polymorphisms (SNPs) from 30 complement pathway genes in a prospective cohort study of newly diagnosed FL (N=107) and DLBCL (N=82) patients enrolled at the Mayo Clinic from 2002–2005. Cox regression was used to estimate Hazard Ratios (HRs) for individual SNPs with EFS, adjusting for FLIPI or IPI and treatment. For gene-level analyses, we used a principal components based gene-level test. In gene-level analyses for FL EFS, CFH (p=0.009), CD55 (p=0.006), CFHR5 (p=0.01), C9 (p=0.02), CFHR1 (p=0.03), and CD46 (p=0.03) were significant at p<0.05, and these genes remained noteworthy after accounting for multiple testing (q<0.15). SNPs in CFH, CFHR1, and CFHR5 showed stronger associations among patients receiving any rituximab, while SNPs from CD55 and CD46 showed stronger associations among patients who were observed. For DLBCL, only CLU (p=0.001) and C7 (p=0.03) were associated with EFS, but did not remain noteworthy after accounting for multiple testing (q>0.15). Genes from the Regulators of Complement Activation (CFH, CD55, CFHR1, CFHR5, CD46) at 1q32-q32.1, along with C9, were associated with FL EFS after adjusting for clinical variables, and if replicated, these findings add further support for the role of host innate immunity in FL prognosis. PMID:22718493

Natural IgM mediates complement-dependent uptake of Francisella tularensis by human neutrophils via CR1 and CR3 in nonimmune serum

PubMed Central

Schwartz, Justin T.; Barker, Jason H.; Long, Matthew E.; Kaufman, Justin; McCracken, Jenna; Allen, Lee-Ann H.

2012-01-01

A fundamental step in the life cycle of F. tularensis is bacterial entry into host cells. F. tularensis activates complement, and recent data suggest that the classical pathway is required for complement factor C3 deposition on the bacterial surface. Nevertheless, C3 deposition is inefficient and neither the specific serum components necessary for classical pathway activation by F. tularensis in nonimmune human serum, nor the receptors that mediate infection of neutrophils has been defined. Herein human neutrophil uptake of GFP-expressing F. tularensis strains LVS and Schu S4 was quantified with high efficiency by flow cytometry. Using depleted sera and purified complement components we demonstrated first that C1q and C3 were essential for F. tularensis phagocytosis whereas C5 was not. Second, we used purification and immuno-depletion approaches to identify a critical role for natural IgM in this process, and then used a wbtA2 mutant to identify LPS O-antigen and capsule as prominent targets of these antibodies on the bacterial surface. Finally, we demonstrate using receptor-blocking antibodies that CR1 (CD35) and CR3 (CD11b/CD18) acted in concert for phagocytosis of opsonized F. tularensis by human neutrophils, whereas CR3 and CR4 (CD11c/CD18) mediated infection of human monocyte-derived macrophages. Altogether, our data provide fundamental insight into mechanisms of F. tularensis phagocytosis and support a model whereby natural IgM binds to surface capsular and O-antigen polysaccharides of F. tularensis and initiates the classical complement cascade via C1q to promote C3-opsonization of the bacterium and phagocytosis via CR3 and either CR1 or CR4 in a phagocyte-specific manner. PMID:22888138

AMD and the alternative complement pathway: genetics and functional implications.

PubMed

Tan, Perciliz L; Bowes Rickman, Catherine; Katsanis, Nicholas

2016-06-21

Age-related macular degeneration (AMD) is an ocular neurodegenerative disorder and is the leading cause of legal blindness in Western societies, with a prevalence of up to 8 % over the age of 60, which continues to increase with age. AMD is characterized by the progressive breakdown of the macula (the central region of the retina), resulting in the loss of central vision including visual acuity. While its molecular etiology remains unclear, advances in genetics and genomics have illuminated the genetic architecture of the disease and have generated attractive pathomechanistic hypotheses. Here, we review the genetic architecture of AMD, considering the contribution of both common and rare alleles to susceptibility, and we explore the possible mechanistic links between photoreceptor degeneration and the alternative complement pathway, a cascade that has emerged as the most potent genetic driver of this disorder.

Function of Serum Complement in Drinking Water Arsenic Toxicity

PubMed Central

Islam, Laila N.; Zahid, M. Shamim Hasan; Nabi, A. H. M. Nurun; Hossain, Mahmud

2012-01-01

Serum complement function was evaluated in 125 affected subjects suffering from drinking water arsenic toxicity. Their mean duration of exposure was 7.4 ± 5.3 yrs, and the levels of arsenic in drinking water and urine samples were 216 ± 211 and 223 ± 302 μg/L, respectively. The mean bactericidal activity of complement from the arsenic patients was 92% and that in the unexposed controls was 99% (P < 0.01), but heat-inactivated serum showed slightly elevated activity than in controls. In patients, the mean complement C3 was 1.56 g/L, and C4 was 0.29 g/L compared to 1.68 g/L and 0.25 g/L, respectively, in the controls. The mean IgG in the arsenic patients was 24.3 g/L that was highly significantly elevated (P < 0.001). Arsenic patients showed a significant direct correlation between C3 and bactericidal activity (P = 0.014). Elevated levels of C4 indicated underutilization and possibly impaired activity of the classical complement pathway. We conclude reduced function of serum complement in drinking water arsenic toxicity. PMID:22545044

Complement research in the 18th-21st centuries: Progress comes with new technology.

PubMed

Sim, R B; Schwaeble, W; Fujita, T

2016-10-01

The complement system has been studied for about 120 years. Progress in defining this large and complex system has been dependent on the research technologies available, but since the introduction of protein chromatography, electrophoresis, and antibody-based assay methods in the 1950s and 60s, and sequencing of proteins and DNA in the 70s and 80s, there has been very rapid accumulation of data. With more recent improvements in 3D structure determination (nmr and X-ray crystallography), the structures of most of the complement proteins have now been solved. Complement research since 1990 has been greatly stimulated by the discoveries of the multiple proteins in the lectin pathway, the strong association of Factor H, C3, Factor B allelic variants with adult macular degeneration and atypical haemolytic uremic syndrome, and the introduction of the anti-C5 monoclonal antibody as a therapy for paroxysmal nocturnal hemoglobinuria and atypical haemolytic uremic syndrome. Potential new roles for complement in tissue development and the search for novel therapeutics suggest a very active future for complement research. Copyright © 2016 Elsevier GmbH. All rights reserved.

Biological effects of contaminated silicon carbide particles from a workstation in a plant producing abrasives.

PubMed

Governa, M; Valentino, M; Amati, M; Visonà, I; Botta, G C; Marcer, G; Gemignani, C

1997-06-01

A sample of silicon carbide dust taken in the field from a plant producing abrasives was studied in vitro. The SiC particles (part unmilled and part milled) were able to disturb the structure of erythrocyte membranes and to lead to blood red-cell lysis; they also either interfered with complement and activated the alternate pathway, or interacted with biological media and polymorphonuclear leucocyte membranes, thus eliciting reactive oxygen species production. These in vitro properties were detected both in original large particles and unmilled particles, over 40% of which were of respirable size. The ability of these SiC particles to produce complement activation in vitro lends support to the previous hypothesis, that the radiographic opacities found in two workers employed in the same area of the plant from which the dust tested was taken are due to a reaction by pulmonary interstitial structures to SiC particle inhalation. It is speculated that SiC particles could act like asbestos, the ability of which to activate complement through the alternate pathway is considered to be one of the mechanisms by which the initial asbestotic lesions and subsequent fibrotic inflammatory infiltrates are generated in the lung.

Ouabain rescues rat nephrogenesis during intrauterine growth restriction by regulating the complement and coagulation cascades and calcium signaling pathway.

PubMed

Chen, L; Yue, J; Han, X; Li, J; Hu, Y

2016-02-01

Intrauterine growth restriction (IUGR) is associated with a reduction in the numbers of nephrons in neonates, which increases the risk of hypertension. Our previous study showed that ouabain protects the development of the embryonic kidney during IUGR. To explore this molecular mechanism, IUGR rats were induced by protein and calorie restriction throughout pregnancy, and ouabain was delivered using a mini osmotic pump. RNA sequencing technology was used to identify the differentially expressed genes (DEGs) of the embryonic kidneys. DEGs were submitted to the Database for Annotation and Visualization and Integrated Discovery, and gene ontology enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were conducted. Maternal malnutrition significantly reduced fetal weight, but ouabain treatment had no significant effect on body weight. A total of 322 (177 upregulated and 145 downregulated) DEGs were detected between control and the IUGR group. Meanwhile, 318 DEGs were found to be differentially expressed (180 increased and 138 decreased) between the IUGR group and the ouabain-treated group. KEGG pathway analysis indicated that maternal undernutrition mainly disrupts the complement and coagulation cascades and the calcium signaling pathway, which could be protected by ouabain treatment. Taken together, these two biological pathways may play an important role in nephrogenesis, indicating potential novel therapeutic targets against the unfavorable effects of IUGR.

THE GENOMIC LANDSCAPE OF PEDIATRIC AND YOUNG ADULT T-LINEAGE ACUTE LYMPHOBLASTIC LEUKEMIA

PubMed Central

Liu, Yu; Easton, John; Shao, Ying; Maciaszek, Jamie; Wang, Zhaoming; Wilkinson, Mark R.; McCastlain, Kelly; Edmonson, Michael; Pounds, Stanley B.; Shi, Lei; Zhou, Xin; Ma, Xiaotu; Sioson, Edgar; Li, Yongjin; Rusch, Michael; Gupta, Pankaj; Pei, Deqing; Cheng, Cheng; Smith, Malcolm A.; Auvil, Jaime Guidry; Gerhard, Daniela S.; Relling, Mary V.; Winick, Naomi J.; Carroll, Andrew J.; Heerema, Nyla A.; Raetz, Elizabeth; Devidas, Meenakshi; Willman, Cheryl L.; Harvey, Richard C.; Carroll, William L.; Dunsmore, Kimberly P.; Winter, Stuart S.; Wood, Brent L; Sorrentino, Brian P.; Downing, James R.; Loh, Mignon L.; Hunger, Stephen P; Zhang, Jinghui; Mullighan, Charles G.

2017-01-01

Genetic alterations activating NOTCH1 signaling and T cell transcription factors, coupled with inactivation of the INK4/ARF tumor suppressors are hallmarks of T-ALL, but detailed genome-wide sequencing of large T-ALL cohorts has not been performed. Using integrated genomic analysis of 264 T-ALL cases, we identify 106 putative driver genes, half of which were not previously described in childhood T-ALL (e.g. CCND3, CTCF, MYB, SMARCA4, ZFP36L2 and MYCN). We described new mechanisms of coding and non-coding alteration, and identify 10 recurrently altered pathways, with associations between mutated genes and pathways, and stage or subtype of T-ALL. For example, NRAS/FLT3 mutations were associated with immature T-ALL, JAK3/STAT5B mutations in HOX1 deregulated ALL, PTPN2 mutations in TLX1 T-ALL, and PIK3R1/PTEN mutations in TAL1 ALL, suggesting that different signaling pathways have distinct roles according to maturational stage. This genomic landscape provides a logical framework for the development of faithful genetic models and new therapeutic approaches. PMID:28671688

[New perspectives on molecular and genic therapies in Down syndrome].

PubMed

Delabar, Jean Maurice

2010-04-01

Trisomy 21 was first described as a syndrome in the middle of the nineteenth century and associated to a chromosomic anomaly one hundred years later: the most salient feature of this syndrome is a mental retardation of variable intensity. Molecular mapping and DNA sequencing have allowed identifying the gene content of chromosome 21. Molecular quantitative analyses indicated that trisomy is inducing an overexpression for a large part of the triplicated genes and deregulates also pathways involving non HSA21 genes. Together with the physiological description of murine models overexpressing orthologous genes, these data have allowed to elaborate hypotheses on the cause of cognitive impairment. From these hypotheses and using murine models it is now possible to assess the efficiency of various therapeutic strategies. This paper reviews these new perspectives starting from the strategies targeting the level of HSA21 RNAs or HSA21 proteins; then it describes methods targeting activities either of proteins involved in cell cycle pathways or of proteins controlling the synaptic plasticity. It is promising that strategies targeting specific genes or specific pathways are already giving positive results.