Long-term safety and activity of cladribine in patients with extranodal B-cell marginal zone lymphoma of the mucosa-associated lymphoid tissue (MALT) lymphoma

About The Author

Prof. Markus Raderer, M.D.

Medical University of Vienna, Vienna, Austria

Markus Raderer undertook his early medical studies at the Medical University of Vienna, completing his residency in internal medicine between 1993 and 1999, specialising in haematology and oncology in 2001. He received the venia docendi for ‘Applied and Experimental Oncology’ and ‘Internal Medicine’ in 1999 and 2002, respectively.  Professor Raderer is currently the Programme Director for Extranodal Lymphomas and for Endocrine Tumours at the Medical University of Vienna. He has been responsible for the management and conduct of phase II and III clinical trials at his institution since 1992.

Professor Raderer is on the Editorial Board of a number of journals including the Journal of Clinical Oncology, World Journal of Gastroenterology, and Middle European Journal of Medical Oncology. He has participated on consensus panels for the European Gastrointestinal Lymphoma Study Group (EGILS) on the topic of B-cell lymphoma of mucosa-associated lymphoid tissue, and the European Society of Medical Oncology (ESMO) on the subject of the management of lymphoid malignancies.

For a list of publications see http://ift.tt/1R9XUti

About The Author

Barbara Kiesewetter, M.D.

Medical University of Vienna, Vienna, Austria

Barbara Kiesewetter undertook her early medical studies at the Medical University of Vienna. Currently she is doing her residency in internal medicine at the Clinical Division of Oncology, Department of Medicine I, Medical University of Vienna, and is a PhD student of the local doctoral program of “Applied Clinical Science”. Dr. Kiesewetter is part of the study group of Prof. Raderer (Extranodal Lymphomas and Endocrine Tumours) since 2010 and was involved in recent clinical trials and scientific work.

For a list of publications see http://ift.tt/1R9XUJA  

Journal Reference

Hematol Oncol. 2015 Nov 18.

Kiesewetter B¹, Dolak W², Simonitsch-Klupp I³, Mayerhoefer ME⁴, Raderer M¹.

Show Affiliations

1. Department of Internal Medicine I, Clinical Division of Oncology, Medical University of Vienna, Vienna, Austria.
2. Department of Internal Medicine III, Clinical Division of Gastroenterology and Hepatology, Medical University of Vienna, Vienna, Austria.
3. Department of Pathology, Medical University of Vienna, Vienna, Austria.
4. Department of Radiology, Medical University of Vienna, Vienna, Austria.

Abstract

The purine analogue 2-chloro-deoxyadenosine (2-CDA, cladribine) +/- rituximab has been successfully tested in mucosa-associated lymphoid tissue lymphoma (MALT lymphoma) patients. However, studies using cladribine in other indications have reported the potential for prolonged hematological side effects and secondary hematologic and non-hematologic malignancies. To date, there have been no data on long-term effects of cladribine inMALT  lymphoma patients. We have analyzed a large number of 49 patients treated with cladribine at our institution 1997-2011. All patients were treated within clinical trials and had undergone a standardized follow-up protocol minimizing a potential bias in the detection of late sequels and relapses. After a median follow-up time of 61 months (interquartile range: 43-72) for 49 analyzed patients, 35 (71%) are alive, while 14 (29%) have died. In the entire collective, three cases (6%) of prolonged pancytopenia including manifest myelodysplastic syndrome in one patient (2%), three cases (6%) of secondary lymphoid malignancies, and five cases (10%) of non-hematologic cancers were documented. In terms of outcome, 42/49 (86%) patients responded to cladribine-containing treatment, and only 10/42 (24%) responding patients needed further treatment after a median time to progression of 14 months (interquartile range, 8-34). Currently, 25/35 (71%) patients being alive are in ongoing complete remission and 2/35 (6%) in ongoing stable disease, respectively. Eight patients (23%) are free of lymphoma after second-line therapy, with the median overall survival not having been reached. Our data suggest that cladribine might be safely applied in patients with MALT lymphoma, also in terms of long-term toxicities. These data also confirm the potential of cladribine to induce durable remissions.

Copyright © 2015 John Wiley & Sons, Ltd.

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Significance information is found in the file below: 

Long-term safety and activity of cladribine in patients with extranodal B-cell marginal zone lymphoma of the mucosa-associated lymphoid tissue (MALT) lymphoma

 

Oncolytic adenovirus targeting cyclin E overexpression repressed tumor growth in syngeneic immunocompetent mice

Significance Statement

Induction of cyclin E by adenoviral E1B55K protein is required for productive virus replication in normal cells. However this viral protein is not required in cancer cells, allowing E1B55K-deleted adenoviruses to conduct oncolytic replication (Fig. A). In many cancer cells cyclin E expression is already deregulated, likely because that the cellular factors targeted by E1B55K may already be activated or there are E1B55K-like factors to relax cyclin E regulation. As the cyclin E promoter is highly active in many types of cancer cells and is further stimulated after adenovirus infection, Cheng and colleagues first applied this unique property of cyclin E promoter into the design of a novel tumor-specific oncolytic adenoviral vector Ad-cycE, in which the cyclin E promoter was used to control the critical regulatory viral E1a gene. Significant and selective antitumor efficacy can be achieved with Ad-cycE (Fig. B). In this study, Cheng et al. further present an interesting new model for the study in an immunocompetent preclinical model of lung cancer. This new model could be of great value in the preclinical development of the new anticancer agents and allow researchers to better evaluate oncolytic adenoviral vectors in a more patient-like setting.

About The Author

Dr. Pei-Hsin Cheng received her Ph.D. degree in Pharmacology and Toxicology from the University of Louisville, in 2013. With the motivation to find innovative biotherapeutics and to develop rational combination strategies for cancer treatments, she joined the St. Jude Children’s Research Hospital as a Postdoctoral Research Associate since 2014. Her research interests include oncolytic virotherapy, gene therapy, miRNA replacement therapy and immunotherapy.

Journal Reference

BMC Cancer. 2015;15:716.

Cheng PH¹, Rao XM², Wechman SL^3,4, Li XF⁵, McMasters KM^6,7, Zhou HS^8,9,10. 

Show Affiliations

1. Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, 40292, USA. paisin.paisin@gmail.com.
2. James Graham Brown Cancer Center, University of Louisville Medical School, 505 South Hancock Street, CTR Building, Room 306, Louisville, KY, 40202, USA. x0rao001@louisville.edu.
3. Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, 40292, USA. slwech01@exchange.louisville.edu.
4. Hiram C. Polk Jr MD Department of Surgery, University of Louisville School of Medicine, Louisville, KY, 40292, USA. slwech01@exchange.louisville.edu.
5. Department of Diagnostic Radiology, University of Louisville School of Medicine, Louisville, KY, 40292, USA. x0li0027@exchange.louisville.edu.
6. Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, 40292, USA. mcmasters@louisville.edu.
7. Hiram C. Polk Jr MD Department of Surgery, University of Louisville School of Medicine, Louisville, KY, 40292, USA. mcmasters@louisville.edu.
8. James Graham Brown Cancer Center, University of Louisville Medical School, 505 South Hancock Street, CTR Building, Room 306, Louisville, KY, 40202, USA. hszhou01@louisville.edu.
9. Hiram C. Polk Jr MD Department of Surgery, University of Louisville School of Medicine, Louisville, KY, 40292, USA. hszhou01@louisville.edu.
10. ⁰Department of Microbiology and Immunology, University of Louisville School of Medicine, Louisville, KY, 40292, USA. hszhou01@louisville.edu.

Abstract

BACKGROUND:

Clinical trials have indicated that preclinical results obtained with human tumor xenografts in mouse models may overstate the potential of adenovirus (Ad)-mediated oncolytic therapies. We have previously demonstrated that the replication of human Ads depends on cyclin E dysregulation or overexpression in cancer cells. ED-1 cell derived from mouse lung adenocarcinomas triggered by transgenic overexpression of human cyclin E may be applied to investigate the antitumor efficacy of oncolytic Ads.

METHODS:

Ad-cycE was used to target cyclin E overexpression in ED-1 cells and repress tumor growth in a syngeneic mouse model for investigation of oncolytic virotherapies.

RESULTS:

Murine ED-1 cells were permissive for human Ad replication and Ad-cycE repressed ED-1 tumor growth in immunocompetent FVB mice. ED-1 cells destroyed by oncolytic Ads in tumors were encircled in capsule-like structures, while cells outside the capsules were not infected and survived the treatment.

CONCLUSION:

Ad-cycE can target cyclin E overexpression in cancer cells and repress tumor growth in syngeneic mouse models. The capsule structures formed after Ad intratumoral injection may prevent viral particles from spreading to the entire tumor.

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Molecular Mechanism of V(D)J Recombination from Synaptic RAG1-RAG2 Complex Structures

Significance Statement

Adaptive immunity is the highest form of specific immunity in jawed vertebrates. Its power is predominantly due to the large and diverse repertoire of antigen receptor genes including antibodies as well as T and B cell receptors for both humoral and cell-mediated immune response during pathogen invasion and tumor surveillance. The diversity of antibody and T and B cell receptors are generated through the combinatorial splicing of V, D and J gene segments in the variable region of antigen receptor genes at the DNA level during lymphocyte development. The V(D)J recombination is initiated by the dimeric (RAG1-RAG2)₂ complex which specifically recognizes a pair of recombination signal sequences, combinatorially pairs gene segments, and presents hairpin gene segments for opening and ligation by DNA damage repair machineries. An important dogma for RAG functions has been the so-called 12/23 rule, which governs the fidelity of the recombination process. In this study, Ru and his colleagues solved the cryo-EM structures of synaptic RAG in complex with various forms of DNA intermediates and products, at near-atomic resolutions. The structures of the synaptic RAG complexes reveal a closed dimer conformation with generation of new intermolecular interactions between two RAG1-RAG2 monomers upon DNA binding, compared to the Apo-RAG complex which constitutes as an open conformation. Both RAG1 molecules in the closed dimer are involved in the cooperative binding of the 12-RSS and 23-RSS intermediates with base specific interactions in the heptamer of the signal end. The first base of the heptamer in the signal end is flipped out to avoid the clash in the active center. Each coding end of the nicked-RSS intermediate is stabilized exclusively by one RAG1-RAG2 monomer with non-specific protein-DNA interactions. The coding end is highly distorted with one base flipped out from the DNA duplex in the active center, which facilitates the hairpin formation by a potential two-metal ion catalytic mechanism. The 12-RSS and 23-RSS intermediates are highly bent and asymmetrically bound to the synaptic RAG complex with the nonamer binding domain dimer tilts towards the nonamer of the 12-RSS but away from the nonamer of the 23-RSS, which emphasizes the 12/23 rule. Two HMGB1 molecules bind at each side of 12-RSS and 23-RSS to stabilize the highly bent RSSs. These structures elaborate the molecular mechanisms for DNA recognition, catalysis and the unique synapsis underlying the 12/23 rule, provide new insights into the RAG-associated human diseases, and represent a most complete set of complexes in the catalytic pathways of any DDE family recombinases, transposases or integrases.

About The Author

Dr. Heng Ru obtained his Ph.D. in Biochemistry and Molecular Biology from the Institute of Biophysics, Chinese Academy of Sciences in 2012. During his Ph.D. training, he mainly focused on mechanistic understanding of innate immune responses against pathogen infections, especially on the molecular mechanism of DNA recognition by cytosolic double-stranded DNA (dsDNA) sensors as well as its downstream signaling. He determined several structures of HIN domains of AIM2-like receptors (ALRs) including AIM2, Ifi16 and p202, and their complexes with dsDNA, as well as the adaptor molecule STING in the apo-form and the pathogenic agonist, c-di-GMP cyclic dinucleotide bound state, by X-ray crystallography. He then joined Dr. Hao Wu’s Lab as a postdoc research fellow at Program in Cellular and Molecular Medicine, Boston Children’s Hospital, and Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School after his graduation. His research focuses on the molecular mechanism and structural basis of RAG1-RAG2 complex in the initial stage of V(D)J recombination.  

About The Author

Dr. Hao Wu received her pre-medical training at Peking University from 1982-1985 and studied Medicine at Peking Union Medical College from 1995-1988. She obtained her Ph.D. from Purdue University in 1992 and performed postdoctoral research at Columbia University. She became an Assistant Professor at Weill Cornell Medical College in 1997 and was promoted to Professor in 2003. In 2012, Dr. Wu moved to Harvard Medical School as the Asa and Patricia Springer Professor of Biological Chemistry and Molecular Pharmacology, and Boston Children’s Hospital as Senior Investigator in the Program in Cellular and Molecular Medicine. Dr. Wu has received a number of honors, including the Pew Scholar award, the Rita Allen Scholar award, the Margaret Dayhoff Memorial Award from the Biophysical Society. She is an elected member of the National Academy of Sciences.  

About The Author

Dr. Maofu Liao received his Bachelor of Science degree in 1999 in Tsinghua University. He joined the Biomedical Science graduate program in Albert Einstein College of Medicine, worked in Dr. Margaret Kielian’s laboratory to study the mechanism of membrane fusion mediated by viral proteins, and obtined his Ph.D. degree in 2006. He then joined Dr. Yifan Cheng’s laboratory at UCSF in 2008 to study protein structure and fuction using cryo-electron microscopy (cryo-EM). Taking the advantage of the newest technologies in single-particle cryo-EM, he determined the near-atomic resolution structures of the TRPV1 ion channel, without the need of forming protein crystals. In 2014, he became an assistant professor in the Department of Cell Biology at Harvard Medical School. The research interests of his laboratory focus on understanding the structure and function of membrane proteins and protein-DNA complexes, and he mainly uses single-particle cryo-EM and a variety of biochemical assays to reveal the underlying mechanisms of these molecular machines in their native environments.

 

Journal Reference

Cell. 2015;163(5):1138-52.

Ru H¹, Chambers MG², Fu TM¹, Tong AB¹, Liao M³, Wu H⁴.

Show Affiliations

1. Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Program in Cellular and Molecular Medicine, Boston Children’s Hospital, Boston, MA 02115, USA.
2. Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
3. Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA. Electronic address: maofu_liao@hms.harvard.edu.
4. Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Program in Cellular and Molecular Medicine, Boston Children’s Hospital, Boston, MA 02115, USA. Electronic address: wu@crystal.harvard.edu. 

Abstract

Diverse repertoires of antigen-receptor genes that result from combinatorial splicing of coding segments by V(D)J recombination are hallmarks of vertebrate immunity. The (RAG1-RAG2)2 recombinase (RAG) recognizes recombination signal sequences (RSSs) containing a heptamer, a spacer of 12 or 23 base pairs, and a nonamer (12-RSS or 23-RSS) and introduces precise breaks at RSS-coding segment junctions. RAG forms synaptic complexes only with one 12-RSS and one 23-RSS, a dogma known as the 12/23 rule that governs the recombination fidelity. We report cryo-electron microscopy structures of synaptic RAG complexes at up to 3.4 Å resolution, which reveal a closed conformation with base flipping and base-specific recognition of RSSs. Distortion at RSS-coding segment junctions and base flipping in coding segments uncover the two-metal-ion catalytic mechanism. Induced asymmetry involving tilting of the nonamer-binding domain dimer of RAG1 upon binding of HMGB1-bent 12-RSS or 23-RSS underlies the molecular mechanism for the 12/23 rule.

Copyright © 2015 Elsevier Inc. All rights reserved.

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Heterogeneous glioblastoma cell cross-talk promotes phenotype alterations and enhanced drug resistance

Journal Reference

Oncotarget. 2015;6(38):40998-1017.

Motaln H¹, Koren A², Gruden K³, Ramšak Ž³, Schichor C⁴, Lah TT^1,5.

Show Affiliations

1. Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, Ljubljana, Slovenia.
2. Laboratory for Clinical Immunology and Molecular Genetics, University Clinic Golnik, Golnik, Slovenia.
3. Department of Biotechnology and Systems Biology, National Institute of Biology, Ljubljana, Slovenia.
4. Department of Neurosurgery, Klinikum Großhadern, Ludwig-Maximilians-Universität, Munich, Germany.
5. Department of Biochemistry, Faculty of Chemistry and Chemical Engineering, University of Ljubljana, Ljubljana, Slovenia.

Abstract

Glioblastoma multiforme is the most lethal of brain cancer, and it comprises a heterogeneous mixture of functionally distinct cancer cells that affect tumor progression. We examined the U87, U251, and U373 malignant cell lines as in vitro models to determine the impact of cellular cross-talk on their phenotypic alterations in co-cultures. These cells were also studied at the transcriptome level, to define the mechanisms of their observed mutually affected genomic stability, proliferation, invasion and resistance to temozolomide. This is the first direct demonstration of the neural and mesenchymal molecular fingerprints of U87 and U373 cells, respectively. U87-cell conditioned medium lowered the genomic stability of U373 (U251) cells, without affecting cell proliferation. In contrast, upon exposure of U87 cells to U373 (U251) conditioned medium, U87 cells showed increased genomic stability, decreased proliferation rates and increased invasion, due to a plethora of produced cytokines identified in the co-culture media. This cross talk altered the expression 264 genes in U87 cells that are associated with proliferation, inflammation, migration, and adhesion, and 221 genes in U373 cells that are associated with apoptosis, the cell cycle, cell differentiation and migration. Indirect and direct co-culturing of U87 and U373 cells showed mutually opposite effects on temozolomide resistance. In conclusion, definition of transcriptional alterations of distinct glioblastoma cells upon co-culturing provides better understanding of the mechanisms of glioblastoma heterogeneity, which will provide the basis for more informed glioma treatment in the future.

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Phenolic profile of Dunaliella tertiolecta growing under high levels of copper and iron

Journal Reference

Environ Sci Pollut Res Int. 2015;22(19):14820-8.

López A¹, Rico M², Santana-Casiano JM¹, González AG¹, González-Dávila M¹.

Show Affiliations

1. Departamento de Química, Facultad de Ciencias del Mar, Universidad de Las Palmas de Gran Canaria, Campus de Tafira, 35017, Las Palmas de Gran Canaria, Canary Islands, Spain.
2. Departamento de Química, Facultad de Ciencias del Mar, Universidad de Las Palmas de Gran Canaria, Campus de Tafira, 35017, Las Palmas de Gran Canaria, Canary Islands, Spain. milagros.ricosantos@ulpgc.es.

Abstract

The present study investigates the phenolic profile of exudates and extracts of the green algae Dunaliella tertiolecta, harvested in natural seawater in the absence (control) and in the presence of Cu(II) (315 and 790 nmol L(-1)) and Fe(III) (900 nmol L(-1)) in order to identify and quantify the phenolic compounds produced under metallic stress conditions. The presence of metal ions modifies the growth of cells and changes cell metabolism by producing phenolic compounds adapted to the solution. The use of reversed-phase high-performance liquid chromatography (RP-HPLC) permitted the identification of 14 phenolic constituents. The concentration and type of polyphenols detected in cell extracts and in solution are directly related with the metal and its concentration during growth cultures, achieving 1.4 times higher levels of polyphenols under 790 nmol Cu(II) L(-1) with respect to the control experiments. Microalga excretes polyphenols to be adapted to the environmental conditions. Gentisic acid, (+) catechin and (-) epicatechin, the most prominent phenolic compounds detected in the algae extracts, showed high antioxidant activity in inhibiting 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. This potent activity may be related to its presence in cells and exudates in high concentrations.

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Apoptotic neurons induce proliferative responses of progenitor cells in the postnatal neocortex

Journal Reference

Exp Neurol. 2015 Nov;273:126-37.

Petrenko V¹, Mihhailova J¹, Salmon P¹, Kiss JZ².

Show Affiliations

1. Department of Neurosciences, University of Geneva Medical School, CH-1211 Geneva 4, Switzerland.
2. Department of Neurosciences, University of Geneva Medical School, CH-1211 Geneva 4, Switzerland. Electronic address: Jozsef.Kiss@unige.ch.

Abstract

Apoptotic cell death is the leading cause of neuronal loss after neonatal brain injury. Little is known about the intrinsic capacity of the immature cerebral cortex for replacing dead cells. Here we test the hypothesis that neuronal apoptosis is able to trigger compensatory proliferation in surrounding cells. In order to establish a “pure” apoptotic cell death model and to avoid the confounding effects of broken blood-brain barrier and inflammatory reactions, we used a diphtheria toxin (DT) and diphtheria toxin receptor (DTR) system to induce ablation of layer IV neurons in the rodent somatosensory cortex during the early postnatal period. We found that DT-triggered apoptosis is a slowly progressing event lasting about for 7days. While dying cells expressed the morphological features of apoptosis, we could not detect immunoreactivity for activated caspase-3 in these cells. Microglia activation and proliferation represented the earliest cellular responses to apoptotic cell death. In addition, we found that induced apoptosis triggered a massive proliferation of undifferentiated progenitor cell pool including Sox2 as well as NG2 cells. The default differentiation pattern of proliferating progenitors appears to be the glial phenotype; we could not find evidence for newly generated neurons in response to apoptotic neuronal death. These results suggest that mitotically active progenitor populations are intrinsically capable to contribute to the repair process of injured cortical tissue and may represent a potential target for neuronal replacement strategies.

Copyright © 2015. Published by Elsevier Inc.

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DDX3 functions in antiviral innate immunity through translational control of PACT

Journal Reference

FEBS J. 2016 Jan;283(1):88-101.

Lai MC¹, Sun HS², Wang SW², Tarn WY³.

Show Affiliations

1. Department of Biomedical Sciences, Chang Gung University, Taoyuan, Taiwan.
2. Institute of Molecular Medicine, National Cheng Kung University, Tainan, Taiwan.
3. Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan.

Abstract

It has emerged that DDX3 plays a role in antiviral innate immunity. However, the exact mechanism by which DDX3 functions in antiviral innate immunity remains to be determined. We found that the expression of the protein activator of the interferon-induced protein kinase (PACT) was regulated by DDX3 in human cells. PACT acts as a cellular activator of retinoic acid-inducible gene-I-like receptors in the sensing of viral RNAs. DDX3 facilitated the translation of PACT mRNA that may contain a structured 5′ UTR. Knockdown of DDX3 decreased the viral RNA detection sensitivity of the cells. PACT partially rescued defects of interferon-β1 and chemokine (C-C motif) ligand 5/RANTES (regulated on activation normal T cell expressed and secreted) induction in DDX3-knockdown HEK293 cells. Therefore, DDX3 may participate in antiviral innate immunity, at least in part, by translational control of PACT. Moreover, we show that overexpression of the hepatitis C virus (HCV) core protein inhibited the translation of a reporter mRNA harboring the PACT 5′ UTR. The HCV core protein was associated and colocalized with DDX3 in cytoplasmic stress granules, suggesting that the HCV core may abrogate the function of DDX3 by sequestering DDX3 in stress granules. The perturbation of DDX3 by viral proteins delineates a critical role for DDX3 in antiviral host defense.

© 2015 FEBS.

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Effects of sodium ions on rat thyrocyte (FRTL-5 cells) swelling- and thyrotropin-activated taurine efflux dependent on cAMP and Epac

Significance Statement

The present paper proposes a novel role of the thyrotropin receptor that belongs to the class A of cell membrane located G-protein coupled receptors. Its activation both from hormone stimulation and from cellular swelling leads to release of the osmolyte taurine. It is suggested that the TSH-receptor protein detects cell volume changes based on its Na+-sensitivity. Activation of this class of hormone receptors appear to involve release of a sodium ion bound in the receptor, and such a release may occur also during swelling activation, associated with a reduced cytosol Na+-concentration. The thyrotropin receptor induced signal that stimulates taurine efflux comprises adenylyl cyclase, cAMP and Epac. Additional strong modulations of signaling elements appeared to occur at locations downstream of cAMP that affects taurine efflux, conditions that were related to cellular volume.

Journal Reference

Amino Acids. 2015 Nov 5. 

Fugelli K.

Department of Biosciences, University of Oslo, POBox 1066, Blindern, 0316, Oslo, Norway. kjell.fugelli@ibv.uio.no.

Abstract

Cellular osmolyte release is important in preventing water accumulation and swelling. However, the signaling pathways that detect volume increase and activate solute efflux are still not fully understood. We investigated efflux activation of the osmolyte taurine which is actively accumulated in rat thyrocytes (FRTL-5). Efflux of accumulated [³H]taurine was stimulated by cellular swelling and thyrotropin (TSH). These effects were significantly diminished in cells having reduced TSH receptor concentrations. Phosphodiesterase inhibitors (IBMX, Rolipram) enhanced both responses. An analog of forskolin (FSK; 7-deacetyl-7-[O-(N-methylpiperazino)-γ-butyryl] dihydrochloride) and an analog of cAMP, specific for activating exchange protein activated directly by cAMP (Epac; 8-(4-chlorophenylthio)-2′-O-methyladenosine-3′,5′-cyclic monophosphate, acetoxymethyl ester), significantly stimulated [³H]taurine efflux. A cAMP analog specific for activating protein kinase A (PKA; N6-benzoyladenosine-3′,5′-cyclic monophosphate, acetoxymethyl ester) had no significant stimulatory effect on [³H]taurine efflux rate. The amiloride analog, 5-(N-ethyl-N-isopropyl)-amiloride, which inhibits a TSH-stimulated Na⁺/H⁺ exchanger, enhanced (100 %) and ouabain inhibited (50 %) the TSH-stimulated [³H]taurine efflux rate. The effect of FSK on efflux was strongly potentiated by Na⁺-free iso-osmotic conditions and by osmolality/cell volume that affected also the db-cAMP-stimulated efflux. The TSH receptors and downstream elements of the signaling pathway comprising adenylyl cyclase, cAMP and Epac appeared to mediate the hormone-induced signal for [³H]taurine efflux from FRTL-5 cells. With less evidence, the cell volume/osmolality-induced [³H]taurine efflux cascade appeared to share some of the hormone signaling elements and to modulate the hormone signaling pathway at two levels through cellular Na⁺.

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Immunomodulatory Effects of Psyllium Extract on Helicobacter pylori Interaction With Gastric Epithelial Cells.

Significance Statement

Plantago ovata (Psyllium, Ispaghul) is a herb of Plantaginaceae family is found widely across the world. Psyllium contains active principals including e.g., 4-O-methylglucuronic acid, aucubin, campesterol, linoleic acid, oleic acid, mucilage, etc, polysaccharides, and arabinoxylans with high gel-forming property Refined Psyllium is used as a prebiotic, in functional bowel disorder, and intestinal inflammation. Plant derived phenolic compounds and flavonoids have reported clinical benefits and pharmacologic effects.  They demonstrate  antiinflammatory activity by modulating the expression levels of cytokines including interleukin- (IL-1), nuclear kappa  B (NF-κB), tumor necrosis factor-alpha (TNF-α), cyclooxygenase (Cox-2), etc.

 Helicobacter pylori (H. pylori) is a Gram negative organism that causes gastritis and is associated with gastrointestinal disorder such as peptic ulcers, gastric malignancies. H. pylori adhere to gastric epithelial cells and stimulate interleukin 8 (IL-8) productions to attract components of the innate and adaptive immune systems. This results in neutrophil infiltration of the gastric epithelium.  H. pylori infection activates NF-κB in gastric epithelial cells in vitro and in vivo. NF-κappa B is a transcriptional regulator of IL-8 production, and its activation is an important defense response in gastrointestinal epithelial cells. Toll-like receptor 2 (TLR2) and TLR5 recognize H. pylori and initiate signaling pathways that activates NF-κB.  H. pylori induced a time-dependent expression of mRNA and protein for IL-8 via activation of NF-κB and increased the levels of IL-8 and IL-6, which were inhibited by NF-κB inhibitor, pyrrolidine dithiocarbamate (PDTC). NF-κB activity is inhibited by glucocorticoids and non-steroidal anti-inflammatory agents. In gastric cancer-derived cell line, MKN45 produce an increased amount of IL-8 upon coculture with live H. pylori indicating that IL-8 production requires a direct contact between the cells and H. pylori. H. pylori directly induced IL-8 mRNA expression and protein secretion and cagA positive and negative strains of H. pylori varied in inducing epithelial IL-8 production. Cell lines are used to model and study drug effects, genetic and immune responses, etc as cells can be grown and treated with drugs under the same condition. We determined the effect of Psyllium husk extract on IL-8 and NF-κB secretion by gastric epithelial cell in response to H. pylori. AGS cell line (Human gastric adenocarcinoma cell line) cells were exposed to Psyllium extract in different concentrations before H. pylori infection. ELISA for IL-8 and NF- κB was used to analyze cell culture supernatant. RNA from cells was used for Real-Time-PCR for messenger RNA expression of IL-8. Psyllium extract 5 and 10μg/ml markedly (P<0.001) lowered basal IL-8 by 64.71% and 74.51%, respectively and H. pylori stimulated IL-8 was also (P<0.001) lowered by 41.67% and 66.67%, respectively. Psyllium 5 and 10μg/ml also reduced (P<0.0001) cagA positive H. pylori induced IL-8 mRNA expression by 42.3% and 67.6%, respectively. Psyllium also reduced (P=0.0001) NF-κB in response to H. pylori strains confirming its role as anti-inflammatory agent. This shows that the Psyllium can play a role in the treatment of H. pylori associated diseases. Psyllium contained compounds will prevent H. pylori contact with gastric epithelial cell important for the pathogenecity of the H. pylori with essential contributions by outer membrane proteins e.g., HopQ, BabA, etc. and its virulence marker e.g., cagA, vacA alleles, etc. Treatment of AGS cells with psyllium decreases IL-8 expression in the presence and absence of H. pylori. It prevents H. pylori from eliciting a proinflammatory host cell response via the activation of NF-κB and mitogen activated protein kinases. Hence psyllium keep dendritic cell and T cells function from being modified by H. pylori. The down regulation of proinflammatory responses makes Psyllium useful for diverse indication. This study showed that Psyllium has an immune modifying effect on gastric epithelial cells. However, randomized controlled study is required to establish the efficacy of Psyllium husk in the treatment of H. pylori infection that can effect secretion of IL-8 by H. pylori.

Journal Reference

J Evid Based Complementary Altern Med. 2015 Oct 16. 

Javed Yakoob^*#, Wasim Jafri^*, Malik Hassan Mehmood^#, Zaigham Abbas^*, Kanwal Tariq^*

Department of Medicine^* and Biological Biomedical Sciences^#, Aga Khan University, Karachi, Pakistan

Abstract

Natural plant product Psyllium has anti-inflammatory activity that can modulate the function of cytokines. We determined the effect of Psyllium huskextract on interleukin (IL)-8 and NF-κB secretion by gastric epithelial cells in response to Helicobacter pylori. Human gastric adenocarcinoma cell line (AGS) cells were pretreated with Psyllium extract in different concentrations before H pylori infection. Cell culture supernatant was analyzed for IL-8 and NF-κB by ELISA. RNA from cells was used for real-time polymerase chain reaction for messenger RNA expression of IL-8. Psyllium extract 5 and 10 μg/mL markedly (P < .001) lowered basal IL-8 by 64.71% and 74.51%, respectively, and H pylori-stimulated IL-8 was also (P < .001) lowered by 41.67% and 66.67%, respectively. Psyllium 5 and 10 μg/mL also reduced (P < .0001) cagA-positive H pylori-induced IL-8 mRNA expression by 42.3% and 67.6%, respectively. Psyllium also reduced (P = .0001) NF-κB in response to H pylori strains confirming its role as an anti-inflammatory agent.

© The Author(s) 2015.

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Differential caspase activity in the cortex and striatum with chronic infusion of 3-nitropropionic acid

Journal Reference

Biochem Biophys Res Commun. 2015;465(3):631-7.

Cho KJ¹, Kim GW².

Show Affiliations

1. Department of Neurology, Severance Hospital, Yonsei University College of Medicine, 50 Yonsei-ro, Seoul, South Korea.
2. Department of Neurology, Severance Hospital, Yonsei University College of Medicine, 50 Yonsei-ro, Seoul, South Korea. Electronic address: gyungkim@yuhs.ac.

Abstract

Systemic administration of 3-nitropropionic acid (3-NP) facilitates the development of select striatal lesions, and some reports provide clues about this pathology. In this study, we investigated the relationship between reduced levels of brain-derived neurotrophic factor (BDNF) in lesioned brain regions and caspase activity, as well as involvement of apoptosis signal-regulating kinase 1 (ASK1) in caspase activation. We analyzed apoptotic cell death, BDNF distribution, caspase-3 activity, caspase-6 activity, ASK1 expression level, and active ASK1 in the cortex and striatum. There were different levels and distributions of these factors within each sub-region. Caspase-6 activity was reduced with down-regulation of ASK1 in the cortex. BDNF protein levels did not decrease in the cortex, but there was replenishment of severely reduced BDNF in the striatum. The present study suggests that an increase in ASK1 in the damaged cortex is related to caspase-6 activation and is involved in cortical depletion of BDNF in the striatum. Furthermore, with systemic infusion of 3-NP, differential expression of ASK1 in the cortex and striatum suggests that this kinase may modulate caspase activation and striatal degeneration.

Copyright © 2015 Elsevier Inc. All rights reserved.

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