Import pathways of the mannityl-opines into the bacterial pathogen Agrobacterium tumefaciens: structural, affinity and in vivo approaches

Agrobacterium tumefaciens pathogens use specific compounds denoted opines as nutrients in their plant tumor niche. These opines are produced by the host plant cells genetically modified by agrobacteria. They are imported into bacteria via solute-binding proteins (SBPs) in association with ATP-binding cassette transporters. The mannityl-opine family encompasses mannopine, mannopinic acid, agropine and agropinic acid. Structural and affinity data on mannopinic acid bound to SBPs are currently lacking while those of the three others mannityl opines are available. We investigated the molecular basis of two pathways for mannopinic acid uptake. MoaA was proposed as the specific SBP for mannopinic acid import in mannityl opines-assimilating agrobacteria, which was validated here using genetic studies and affinity measurements. We structurally characterized the mannopinic acid-binding mode of MoaA in two crystal forms at 2.05 and 1.57 Å resolution. We demonstrated that the non-specific SBP MotA, so far characterized as mannopine and Amadori compound importer, was also able to transport mannopinic acid. The structure of MotA bound to mannopinic acid at 2.2 Å resolution defines a different mannopinic acid-binding signature, similar to that of mannopine. Combining in vitro and in vivo approaches, this work allowed us to complete the characterization of the mannityl-opines assimilation pathways, highlighting the important role of two dual imports of agropinic and mannopinic acids. Our data shed new light on how the mannityl-opines contribute to the establishment of the ecological niche of agrobacteria from the early to the late stages of tumor development.

Download Full-text

Репрограммированые in vitro на М3 фенотип макрофаги останавливают рост солидной карциномы in vivo

ZHurnal «Patologicheskaia fiziologiia i eksperimental`naia terapiia» ◽

10.25557/0031-2991.2018.01.41-46 ◽

2018 ◽

pp. 41-46

Author(s):

А.А. Раецкая ◽

С.В. Калиш ◽

С.В. Лямина ◽

Е.В. Малышева ◽

О.П. Буданова ◽

...

Keyword(s):

Solid Tumor ◽

Antitumor Effect ◽

Tumor Development ◽

Significant Inhibition ◽

The Body ◽

Ehrlich Carcinoma ◽

Solid Carcinoma ◽

Ec Cells

Цель исследования. Доказательство гипотезы, что репрограммированные in vitro на М3 фенотип макрофаги при введении в организм будут существенно ограничивать развитие солидной карциномы in vivo . Методика. Рост солидной опухоли инициировали у мышей in vivo путем подкожной инъекции клеток карциномы Эрлиха (КЭ). Инъекцию макрофагов с нативным М0 фенотипом и с репрограммированным M3 фенотипом проводили в область формирования солидной КЭ. Репрограммирование проводили с помощью низких доз сыворотки, блокаторов факторов транскрипции STAT3/6 и SMAD3 и липополисахарида. Использовали две схемы введения макрофагов: раннее и позднее. При раннем введении макрофаги вводили на 1-е, 5-е, 10-е и 15-е сут. после инъекции клеток КЭ путем обкалывания макрофагами с четырех сторон область развития опухоли. При позднем введении, макрофаги вводили на 10-е, 15-е, 20-е и 25-е сут. Через 15 и 30 сут. после введения клеток КЭ солидную опухоль иссекали и измеряли ее объем. Эффект введения макрофагов оценивали качественно по визуальной и пальпаторной характеристикам солидной опухоли и количественно по изменению ее объема по сравнению с группой без введения макрофагов (контроль). Результаты. Установлено, что M3 макрофаги при раннем введении от начала развития опухоли оказывают выраженный антиопухолевый эффект in vivo , который был существенно более выражен, чем при позднем введении макрофагов. Заключение. Установлено, что введение репрограммированных макрофагов M3 ограничивает развитие солидной карциномы в экспериментах in vivo . Противоопухолевый эффект более выражен при раннем введении М3 макрофагов. Обнаруженные в работе факты делают перспективным разработку клинической версии биотехнологии ограничения роста опухоли, путем предварительного программирования антиопухолевого врожденного иммунного ответа «в пробирке». Aim. To verify a hypothesis that macrophages reprogrammed in vitro to the M3 phenotype and injected into the body substantially restrict the development of solid carcinoma in vivo . Methods. Growth of a solid tumor was initiated in mice in vivo with a subcutaneous injection of Ehrlich carcinoma (EC) cells. Macrophages with a native M0 phenotype or reprogrammed towards the M3 phenotype were injected into the region of developing solid EC. Reprogramming was performed using low doses of serum, STAT3/6 and SMAD3 transcription factor blockers, and lipopolysaccharide. Two schemes of macrophage administration were used: early and late. With the early administration, macrophages were injected on days 1, 5, 10, and 15 following the injection of EC cells at four sides of the tumor development area. With the late administration, macrophages were injected on days 10, 15, 20, and 25. At 15 and 30 days after the EC cell injection, the solid tumor was excised and its volume was measured. The effect of macrophage administration was assessed both qualitatively by visual and palpation characteristics of solid tumor and quantitatively by changes in the tumor volume compared with the group without the macrophage treatment. Results. M3 macrophages administered early after the onset of tumor development exerted a pronounced antitumor effect in vivo , which was significantly greater than the antitumor effect of the late administration of M3 macrophages. Conclusion. The observed significant inhibition of in vivo growth of solid carcinoma by M3 macrophages makes promising the development of a clinical version of the biotechnology for restriction of tumor growth by in vitro pre-programming of the antitumor, innate immune response.

Download Full-text

Kinase Targets for Mycolic Acid Biosynthesis in Mycobacterium tuberculosis

Current Molecular Pharmacology ◽

10.2174/1874467211666181025141114 ◽

2019 ◽

Vol 12 (1) ◽

pp. 27-49 ◽

Cited By ~ 6

Author(s):

Shahinda S.R. Alsayed ◽

Chau C. Beh ◽

Neil R. Foster ◽

Alan D. Payne ◽

Yu Yu ◽

...

Keyword(s):

Mycobacterium Tuberculosis ◽

Enzymatic Activity ◽

Bacterial Pathogen ◽

Building Blocks ◽

Mycolic Acid ◽

Adaptive Responses ◽

Mycolic Acids ◽

Hydroxylated Fatty Acids

Background:Mycolic acids (MAs) are the characteristic, integral building blocks for the mycomembrane belonging to the insidious bacterial pathogen Mycobacterium tuberculosis (M.tb). These C60-C90 long α-alkyl-β-hydroxylated fatty acids provide protection to the tubercle bacilli against the outside threats, thus allowing its survival, virulence and resistance to the current antibacterial agents. In the post-genomic era, progress has been made towards understanding the crucial enzymatic machineries involved in the biosynthesis of MAs in M.tb. However, gaps still remain in the exact role of the phosphorylation and dephosphorylation of regulatory mechanisms within these systems. To date, a total of 11 serine-threonine protein kinases (STPKs) are found in M.tb. Most enzymes implicated in the MAs synthesis were found to be phosphorylated in vitro and/or in vivo. For instance, phosphorylation of KasA, KasB, mtFabH, InhA, MabA, and FadD32 downregulated their enzymatic activity, while phosphorylation of VirS increased its enzymatic activity. These observations suggest that the kinases and phosphatases system could play a role in M.tb adaptive responses and survival mechanisms in the human host. As the mycobacterial STPKs do not share a high sequence homology to the human’s, there have been some early drug discovery efforts towards developing potent and selective inhibitors.Objective:Recent updates to the kinases and phosphatases involved in the regulation of MAs biosynthesis will be presented in this mini-review, including their known small molecule inhibitors.Conclusion:Mycobacterial kinases and phosphatases involved in the MAs regulation may serve as a useful avenue for antitubercular therapy.

Download Full-text

Functional Characterization of the mazEF Toxin-Antitoxin System in the Pathogenic Bacterium Agrobacterium tumefaciens

Microorganisms ◽

10.3390/microorganisms9051107 ◽

2021 ◽

Vol 9 (5) ◽

pp. 1107

Author(s):

Wonho Choi ◽

Yoshihiro Yamaguchi ◽

Ji-Young Park ◽

Sang-Hyun Park ◽

Hyeok-Won Lee ◽

...

Keyword(s):

Agrobacterium Tumefaciens ◽

Physiological Function ◽

Functional Characterization ◽

Site Directed Mutagenesis ◽

In Vitro Assays ◽

Cell Growth Inhibition ◽

The Right

Agrobacterium tumefaciens is a pathogen of various plants which transfers its own DNA (T-DNA) to the host plants. It is used for producing genetically modified plants with this ability. To control T-DNA transfer to the right place, toxin-antitoxin (TA) systems of A. tumefaciens were used to control the target site of transfer without any unintentional targeting. Here, we describe a toxin-antitoxin system, Atu0939 (mazE-at) and Atu0940 (mazF-at), in the chromosome of Agrobacterium tumefaciens. The toxin in the TA system has 33.3% identity and 45.5% similarity with MazF in Escherichia coli. The expression of MazF-at caused cell growth inhibition, while cells with MazF-at co-expressed with MazE-at grew normally. In vivo and in vitro assays revealed that MazF-at inhibited protein synthesis by decreasing the cellular mRNA stability. Moreover, the catalytic residue of MazF-at was determined to be the 24th glutamic acid using site-directed mutagenesis. From the results, we concluded that MazF-at is a type II toxin-antitoxin system and a ribosome-independent endoribonuclease. Here, we characterized a TA system in A. tumefaciens whose understanding might help to find its physiological function and to develop further applications.

Download Full-text

TMOD-02. GENERATION OF A NOVEL MOUSE MODEL FOR BRAIN TUMORS OF THE DNA METHYLATION CLASS “GBM MYCN”

Neuro-Oncology ◽

10.1093/neuonc/noab196.864 ◽

2021 ◽

Vol 23 (Supplement_6) ◽

pp. vi215-vi216

Author(s):

Melanie Schoof ◽

Carolin Göbel ◽

Dörthe Holdhof ◽

Sina Al-Kershi ◽

Ulrich Schüller

Keyword(s):

Dna Methylation ◽

Brain Tumors ◽

Molecular Mechanisms ◽

Treatment Options ◽

Tumor Development ◽

Model Systems ◽

Preclinical Research ◽

Human Gbm

Abstract DNA methylation based classification of brain tumors has revealed a high heterogeneity between tumors and led to the description of multiple distinct subclasses. The increasing subdivision of tumors can help to understand molecular mechanisms of tumor development and to improve therapy if appropriate model systems for preclinical research are available. Multiple recent publications have described a subgroup of pediatric glioblastoma which is clearly separable from other pediatric and adult glioblastoma in its DNA methylation profile (GBM MYCN). Many cases in this group are driven by MYCN amplifications and harbor TP53 mutations. These tumors almost exclusively occur in children and were further described as highly aggressive with a median overall survival of only 14 months. In order to further investigate the biology and treatment options of these tumors, we generated hGFAP-cre::TP53 Fl/Fl ::lsl-MYCN mice. These mice carry a loss of TP53 and show aberrant MYCN expression in neural precursors of the central nervous system. The animals develop large forebrain tumors within the first 80 days of life with 100 % penetrance. These tumors resemble human GBM MYCN tumors histologically and are sensitive to AURKA and ATR inhibitors in vitro. We believe that further characterization of the model and in vivo treatment studies will pave the way to improve treatment of patients with these highly aggressive tumors.

Download Full-text

Dual oxidase 1 limits the IFNγ-associated antitumor effect of macrophages

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2020-000622 ◽

2020 ◽

Vol 8 (1) ◽

pp. e000622

Author(s):

Lydia Meziani ◽

Marine Gerbé de Thoré ◽

Pauline Hamon ◽

Sophie Bockel ◽

Ruy Andrade Louzada ◽

...

Keyword(s):

Antitumor Effect ◽

Therapeutic Strategy ◽

Critical Role ◽

Tumor Development ◽

Intratumoral Injection ◽

Histocompatibility Complex ◽

Dual Oxidase

BackgroundMacrophages play pivotal roles in tumor progression and the response to anticancer therapies, including radiotherapy (RT). Dual oxidase (DUOX) 1 is a transmembrane enzyme that plays a critical role in oxidant generation.MethodsSince we found DUOX1 expression in macrophages from human lung samples exposed to ionizing radiation, we aimed to assess the involvement of DUOX1 in macrophage activation and the role of these macrophages in tumor development.ResultsUsing Duox1−/− mice, we demonstrated that the lack of DUOX1 in proinflammatory macrophages improved the antitumor effect of these cells. Furthermore, intratumoral injection of Duox1−/− proinflammatory macrophages significantly enhanced the antitumor effect of RT. Mechanistically, DUOX1 deficiency increased the production of proinflammatory cytokines (IFNγ, CXCL9, CCL3 and TNFα) by activated macrophages in vitro and the expression of major histocompatibility complex class II in the membranes of macrophages. We also demonstrated that DUOX1 was involved in the phagocytotic function of macrophages in vitro and in vivo. The antitumor effect of Duox1−/− macrophages was associated with a significant increase in IFNγ production by both lymphoid and myeloid immune cells.ConclusionsOur data indicate that DUOX1 is a new target for macrophage reprogramming and suggest that DUOX1 inhibition in macrophages combined with RT is a new therapeutic strategy for the management of cancers.

Download Full-text

Yanghe Huayan decoction inhibits the capability of trans-endothelium and angiogenesis of HER2+ breast cancer via pAkt signaling

Bioscience Reports ◽

10.1042/bsr20181260 ◽

2019 ◽

Vol 39 (2) ◽

Cited By ~ 1

Author(s):

Xiao-Fei Liu ◽

Jing-Wei Li ◽

Hong-Zhi Chen ◽

Zi-Yuan Sun ◽

Guang-Xi Shi ◽

...

Keyword(s):

Breast Cancer ◽

Chinese Medicine ◽

Precancerous Lesion ◽

Tumor Development ◽

Akt Activation ◽

Her2 Breast Cancer ◽

Prevention And Treatment

Abstract Background: Yanghe Huayan Decoction (YHD), a traditional Chinese medicine, is one of the most common complementary medicine currently used in the treatment of breast cancer (BC). It has been recently linked to suppress precancerous lesion and tumor development. The current study sought to explore the role of YHD on trans-endothelium and angiogenesis of BC. Methods: HER2+ BC cells were treated with YHD, Trastuzumab, or the combination in vitro and in vivo to compare the effects of them on trans-endothelium and angiogenesis features. The present study also investigated the potential molecular mechanism of YHD in inhibiting angiogenesis of BC. Results: YHD significantly suppressed the invasion and angiogenesis of BC cells via elevated pAkt signaling. Administration of YHD in vivo also strikingly repressed angiogenesis in tumor grafts. Conclusion: YHD could partially inhibit and reverse tumorigenesis of BC. It also could inhibit Akt activation and angiogenesis in vitro and in vivo. Its effect was superior to trastuzumab. Thus it was suitable for prevention and treatment of BC.

Download Full-text

Staufen1 reads out structure and sequence features in ARF1 dsRNA for target recognition

Nucleic Acids Research ◽

10.1093/nar/gkz1163 ◽

2019 ◽

Vol 48 (4) ◽

pp. 2091-2106 ◽

Cited By ~ 2

Author(s):

Deepak Kumar Yadav ◽

Dagmar Zigáčková ◽

Maria Zlobina ◽

Tomáš Klumpler ◽

Christelle Beaumont ◽

...

Keyword(s):

Translational Control ◽

Target Recognition ◽

Target Selection ◽

Binding Mode ◽

Minor Groove ◽

Mrna Levels ◽

Mrna Targets ◽

Dsrna Binding

Abstract Staufen1 (STAU1) is a dsRNA binding protein mediating mRNA transport and localization, translational control and STAU1-mediated mRNA decay (SMD). The STAU1 binding site (SBS) within human ADP-ribosylation factor1 (ARF1) 3′UTR binds STAU1 and this downregulates ARF1 cytoplasmic mRNA levels by SMD. However, how STAU1 recognizes specific mRNA targets is still under debate. Our structure of the ARF1 SBS–STAU1 complex uncovers target recognition by STAU1. STAU1 dsRNA binding domain (dsRBD) 4 interacts with two pyrimidines and one purine from the minor groove side via helix α1, the β1–β2 loop anchors the dsRBD at the end of the dsRNA and lysines in helix α2 bind to the phosphodiester backbone from the major groove side. STAU1 dsRBD3 displays the same binding mode with specific recognition of one guanine base. Mutants disrupting minor groove recognition of ARF1 SBS affect in vitro binding and reduce SMD in vivo. Our data thus reveal how STAU1 recognizes minor groove features in dsRNA relevant for target selection.

Download Full-text

STRUCTURE-BASED MULTITARGETED MOLECULAR DOCKING ANALYSIS OF PYRAZOLE-CONDENSED HETEROCYCLICS AGAINST LUNG CANCER

International Journal of Applied Pharmaceutics ◽

10.22159/ijap.2021v13i6.42801 ◽

2021 ◽

pp. 157-169

Author(s):

JAINEY P. JAMES ◽

AISWARYA T. C. ◽

SNEH PRIYA ◽

DIVYA JYOTHI ◽

SHESHAGIRI R. DIXIT

Keyword(s):

Lung Cancer ◽

Molecular Docking ◽

Binding Mode ◽

Pharmacophore Modeling ◽

In Vivo Studies ◽

Spectral Studies ◽

Pyrazole Derivatives ◽

Anticancer Activities

Objective: The significant drawbacks of chemotherapy are that it destroys healthy cells, resulting in adverse effects. Hence, there is a need to adopt new techniques to develop cancer-specific chemicals that target the molecular pathways in a non-toxic fashion. This study aims to screen pyrazole-condensed heterocyclics for their anticancer activities and analyse their enzyme inhibitory potentials EGFR, ALK, VEGFR and TNKS receptors. Methods: The structures of the compounds were confirmed by IR, NMR and Mass spectral studies. The in silico techniques applied in this study were molecular docking and pharmacophore modeling to analyse the protein-ligand interactions, as they have a significant role in drug discovery. Drug-likeness properties were assessed by the Lipinski rule of five and ADMET properties. Anticancer activity was performed by in vitro MTT assay on lung cancer cell lines. Results: The results confirm that all the synthesised pyrazole derivatives interacted well with the selected targets showing docking scores above-5 kcal/mol. Pyrazole 2e interacted well with all the four lung cancer targets with its stable binding mode and was found to be potent as per the in vitro reports, followed by compounds 3d and 2d. Pharmacophore modeling exposed the responsible features responsible for the anticancer action. ADMET properties reported that all the compounds were found to have properties within the standard limit. The activity spectra of the pyrazoles predicted that pyrazolopyridines (2a-2e) are more effective against specific receptors such as EGFR, ALK and Tankyrase. Conclusion: Thus, this study suggests that the synthesised pyrazole derivatives can be further investigated to validate their enzyme inhibitory potentials by in vivo studies.

Download Full-text

Remodeling tumor microenvironment by liposomal co-delivery of DMXAA and simvastatin inhibits malignant melanoma progression

10.1101/2021.04.26.441259 ◽

2021 ◽

Author(s):

Valentin Florian Rauca ◽

Laura Patras ◽

Lavinia Luput ◽

Emilia Licarete ◽

Vlad Alexandru Toma ◽

...

Keyword(s):

Tumor Microenvironment ◽

Hypoxia Inducible Factor ◽

Tumor Development ◽

Novel Therapy ◽

Drug Induced ◽

Angiogenic Therapy ◽

Melanoma Model ◽

M1 Phenotype

Anti-angiogenic therapies for melanoma have not yet been translated into meaningful clinical benefit for patients, due to development of drug-induced resistance in cancer cells, mainly caused by hypoxia-inducible factor 1α (HIF-1α) overexpression and enhanced oxidative stress mediated by tumor-associated macrophages (TAMs). Our previous study demonstrated synergistic antitumor actions of simvastatin (SIM) and 5,6-dimethylxanthenone-4-acetic acid (DMXAA) on an in vitro melanoma model via suppression of the aggressive phenotype of melanoma cells and inhibition of TAMs-mediated angiogenesis. Therefore, we took the advantage of long circulating liposomes (LCL) superior tumor targeting capacity to efficiently deliver SIM and DMXAA to B16.F10 melanoma in vivo, with the final aim of improving the outcome of the anti-angiogenic therapy. Thus, we assessed the effects of this novel combined tumor-targeted treatment on s.c. B16.F10 murine melanoma growth and on the production of critical markers involved in tumor development and progression. Our results showed that the combined liposomal therapy inhibited almost totally the growth of melanoma tumors, due to the enhancement of anti-angiogenic effects of LCL-DMXAA by LCL-SIM and induction of a pro-apoptotic state in the tumor microenvironment (TME). These effects were favoured by the partial re-education of TAMs towards a M1 phenotype and maintained via suppression of major invasion and metastasis promoters (HIF-1α, pAP-1 c-Jun, and MMPs). Thus, this novel therapy holds the potential to remodel the tumor microenvironment, by suppressing its most important malignant biological capabilities.

Download Full-text

In Vitro and in Vivo Characterisation of P. Aeruginosa Oxidoreductase Enzymes in Pathogenesis and Therapy

10.26686/wgtn.17003215 ◽

2021 ◽

Author(s):

◽

Laura Kay Green

Keyword(s):

Bacterial Pathogen ◽

Protective Role ◽

Infection Model ◽

Virulence Determinants ◽

Genetic Redundancy ◽

Quinone Oxidoreductase ◽

Native Form ◽

Enzyme Prodrug Therapy

<p>Pseudomonas aeruginosa, an increasingly multi-drug resistant human pathogen, is now one of the top three causes of opportunistic infection and there is much interest in identifying novel therapeutic targets for treatment. As a bacterial pathogen, P. aeruginosa encounters innate immune system defences and must continue to adapt to its defence strategies to accommodate the ever-changing environment. Though P. aeruginosa virulence determinants have been heavily characterised over the last several decades, most recent work acknowledges the complex interaction between the human host and the pathogen as an on-going dialogue of virulence factors adapting to the continuum that is the immune response. A major challenge that P. aeruginosa must overcome are reactive oxygen species (ROS) that are released at all stages of infection. Based on previous work which demonstrated a role for soluble nitro- and quinone oxidoreductase (NQOR) enzymes in protecting a related bacterium (Pseudomonas putida) from oxidative stress, we hypothesized that P. aeruginosa would similarly utilize NQORs to withstand ROS. This thesis seeks to understand the role of ROS-protecting enzymes in pathogenesis as well as their potential applications in a therapeutic context. Several NQORs of P. aeruginosa were identified to possess biochemical characteristics consistent with the enzymatic capacity to indirectly reduce reactive species like H₂O₂. However, when individual genes encoding NQORs were deleted from P. aeruginosa, no apparent H₂O₂ sensitivity was seen. In contrast, when candidate genes were over-expressed, certain NQOR enzymes conferred the ability to tolerate H₂O₂ challenge at low concentrations; indicating that these NQORs may play a protective role whose effects are masked in vitro by genetic redundancy as well as a highly active endogenous catalase. By developing a novel in vivo cell culture infection model, the survival of P. aeruginosa post exposure to immunocompetent murine macrophages was also assessed. This not only demonstrated that several putative NQORs were activated in the presence of macrophages but also that an in vivo modelling system is likely to be more appropriate for discovering virulence determinants. In a different aspect of this study it was investigated whether the reductive capacity of the P. aeruginosa-derived NQORs might hold potential for gene-directed enzyme-prodrug therapy (GDEPT). Prodrugs, such as 5-(aziridin-1-yl)-2,4-dinitrobenzamide (CB1954) or the nitro-chloromethyl benzindoline SN 26438, are nontoxic in their native form, but become highly toxic upon reduction of their nitro functional groups. The P. aeruginosa NQORs, were tested to identify enzymes capable of efficient activation of CB1954 or SN 26438. Although none of these enzymes exhibited greater activity with CB1954 than the “best in class” Eschericha coli enzymes NfsA or NfsB, the P. aeruginosa NfsB orthologue (PA5190) demonstrated greater than 20-fold improved activity over NfsB from Escherichia coli in its ability to sensitise human cells to SN 26438. This finding offers promise for development of PA5190 and SN 26438 as a novel enzyme-prodrug paradigm for GDEPT.</p>

Download Full-text