scholarly journals In vitro co-metabolism of epigallocatechin-3-gallate (EGCG) by the mucin-degrading bacterium Akkermansia muciniphila

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0260757
Author(s):  
Yun Xia ◽  
Xuxiang Zhang ◽  
Mingxin Jiang ◽  
Hongbo Zhang ◽  
Yinfeng Wang ◽  
...  
Keyword(s):  
Growth Stimulation ◽  
Promoting Effect ◽  
Mineral Salts ◽  
Culture Studies ◽  
Akkermansia Muciniphila ◽  
Degrading Bacterium ◽  
Metabolomic Data ◽  
Important Addition ◽  
Growth Promoting

Akkermansia muciniphila is a Gram-negative bacterium that resides within the gut mucus layer, and plays an important role in promoting gut barrier integrity, modulating the immune response and inhibiting gut inflammation. Growth stimulation of A. muciniphila by polyphenols including epigallocatechin-3-gallate (EGCG) from difference sources is well-documented. However, no published in vitro culture data on utilization of polyphenols by A. muciniphila are available, and the mechanism of growth-stimulating prebiotic effect of polyphenols on it remains unclear. Here in vitro culture studies have been carried out on the metabolism of EGCG by A. muciniphila in the presence of either mucin or glucose. We found that A. muciniphila did not metabolize EGCG alone but could co-metabolize it together with both these substrates in the presence of mineral salts and amino acids for mucin and protein sources for glucose. Our metabolomic data show that A. muciniphila converts EGCG to gallic acid, epigallocatechin, and (-)-epicatechin through ester hydrolysis. The (-)-epicatechin formed is then further converted to hydroxyhydroquinone. Co-metabolism of A. muciniphila of EGCG together with either mucin or glucose promoted substantially its growth, which serves as a further demonstration of the growth-promoting effect of polyphenols on A. muciniphila and provides an important addition to the currently available proposed mechanisms of polyphenolic prebiotic effects on A. muciniphila.

scholarly journals PAPA-1 Is a Nuclear Binding Partner of IGFBP-2 and Modulates Its Growth-Promoting Actions

2009 ◽  
Vol 23 (2) ◽  
pp. 169-175 ◽  
Author(s):  
Kenichi Miyako ◽  
Laura J. Cobb ◽  
Malik Francis ◽  
Alden Huang ◽  
Bonnie Peng ◽  
...  
Keyword(s):  
Glutathione S Transferase ◽  
Mouse Embryonic Fibroblasts ◽  
Promoting Effect ◽  
Embryonic Fibroblasts ◽  
Igf Binding Proteins ◽  
Cellular Effects ◽  
Igf Binding ◽  
Growth Promoting ◽  
Interfering Rna

Abstract IGF-binding proteins (IGFBPs) have multiple cellular effects, which occur by both IGF-dependent and -independent mechanisms. IGFBP-2 is involved in the regulation of both normal and carcinogenic cell growth. To further understand the actions of IGFBP-2, we carried out a yeast two-hybrid screen to search for intracellular partner proteins using a human prostate cDNA library. We isolated Pim-1-associated protein-1 (PAP-1)-associated protein-1 (PAPA-1) as an IGFBP-2-binding protein, whose expression and subcellular localization is regulated by both IGFBP-2 and androgens. Coimmunoprecipitation and glutathione S-transferase pull-down assay confirmed the interaction in vitro, and confocal microscopy showed the colocalization of IGFBP-2 and PAPA-1 in the nucleus. Suppression of PAPA-1 by small interfering RNA treatment enhanced the growth-promoting effect of IGFBP-2. Conversely, IGFBP-2-promoted bromodeoxyuridine incorporation into LNCaP cells was abrogated by the simultaneous overexpression of myc-hPAPA-1. Mouse embryonic fibroblasts from IGFBP-2 knockout mouse showed diminished growth activity compared with wild type, and expression of FLAG-mPAPA-1 decreased cell proliferation in IGFBP-2 knockout, but not control mouse embryonic fibroblasts. These studies suggest that the growth-promoting role of IGFBP-2 in prostate cancer is inhibited by its intracellular interaction with PAPA-1.

scholarly journals Necroptosis regulates tumor repopulation after radiotherapy via RIP1/RIP3/MLKL/JNK/IL8 pathway

2019 ◽  
Vol 38 (1) ◽  
Author(s):  
Yiwei Wang ◽  
Minghui Zhao ◽  
Sijia He ◽  
Yuntao Luo ◽  
Yucui Zhao ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Growth Stimulation ◽  
Underlying Mechanism ◽  
Promoting Effect ◽  
Clinical Prognosis ◽  
Associated Proteins ◽  
Radiation Induced ◽  
Colorectal Cancer Patients

Abstract Background Tumor cell repopulation after radiotherapy is a major cause for the tumor radioresistance and recurrence. This study aims to investigate the underlying mechanism of tumor repopulation after radiotherapy, with focus on whether and how necroptosis takes part in this process. Methods Necroptosis after irradiation were examined in vitro and in vivo. And the growth-promoting effect of necroptotic cells was investigated by chemical inhibitors or shRNA against necroptosis associated proteins and genes in in vitro and in vivo tumor repopulation models. Downstream relevance factors of necroptosis were identified by western blot and chemiluminescent immunoassays. Finally, the immunohistochemistry staining of identified necroptosis association growth stimulation factor was conducted in human colorectal tumor specimens to verify the relationship with clinical outcome. Results Radiation-induced necroptosis depended on activation of RIP1/RIP3/MLKL pathway, and the evidence in vitro and in vivo demonstrated that the inhibition of necroptosis attenuated growth-stimulating effects of irradiated tumor cells on living tumor reporter cells. The JNK/IL-8 were identified as downstream molecules of pMLKL during necroptosis, and inhibition of JNK, IL-8 or IL-8 receptor significantly reduced tumor repopulation after radiotherapy. Moreover, the high expression of IL-8 was associated with poor clinical prognosis in colorectal cancer patients. Conclusions Necroptosis associated tumor repopulation after radiotherapy depended on activation of RIP1/RIP3/MLKL/JNK/IL-8 pathway. This novel pathway provided new insight into understanding the mechanism of tumor radioresistance and repopulation, and MLKL/JNK/IL-8 could be developed as promising targets for blocking tumor repopulation to enhance the efficacy of colorectal cancer radiotherapy.

scholarly journals Biodegradation of propiconazole by Pseudomonas putida isolated from tea rhizosphere

2009 ◽  
Vol 55 (No. 5) ◽  
pp. 196-201 ◽  
Author(s):  
S. Sarkar ◽  
S. Seenivasan ◽  
R. Premkumar
Keyword(s):  
Pseudomonas Putida ◽  
Ammonium Nitrate ◽  
Carbon Sources ◽  
Nitrogen Sources ◽  
Nutritional Requirements ◽  
Mineral Salts ◽  
Tolerance Level ◽  
Triazole Fungicide ◽  
Growth Promoting

Biodegradation of triazole fungicide propiconazole was carried out <I>in vitro</I> by selected <I>Pseudomonas</I> strains isolated from tea rhizosphere. A total number of twelve strains were isolated and further screened based on their tolerance level to propiconazole. Four best strains were selected and further tested for their nutritional requirements. Among the different carbon sources tested glucose exhibited the highest growth promoting capacity and among nitrogen sources ammonium nitrate supported the growth to the maximum. The four selected <I>Pseudomonas</I> strains exhibited a range of degradation capabilities. Mineral salts medium (MSM) amended with glucose provided better environment for degradation with the highest degradation potential in strain MPR 4 followed by MPR 12 (72.8% and 67.8%, respectively).

Compatibility of plant growth promoting rhizobacterial strains with agrichemicals applied to seed

1992 ◽  
Vol 38 (1) ◽  
pp. 45-50 ◽  
Author(s):  
Robert M. Zablotowicz ◽  
Caroline M. Press ◽  
Nicola Lyng ◽  
Gerry L. Brown ◽  
Joseph W. Kloepper
Keyword(s):  
Plant Growth ◽  
Plant Growth Promoting Rhizobacteria ◽  
Growth Stimulation ◽  
Seed Treatments ◽  
Greenhouse Study ◽  
Select Group ◽  
Plant Growth Promoting ◽  
Growth Promoting

The compatibility of a select group of plant growth promoting rhizobacterial strains with chemicals commonly used as seed treatments was investigated. Strains in several genera (Serratia, Pseudomonas, and coryneform-like bacteria) were found to be tolerant to Vitavax RS (containing lindane, carboxin, and thiram), Epic (iprodione), and (or) captan tested in vitro at commercial rates. Six of 10 strains survived equally, and exhibited similar root colonization, on Vitavax RS treated and nontreated seed. Four of seven strains tested (Serratia spp. and P. fluorescens) were likewise found to be compatible with a captan seed treatment on supersweet corn, using the same criteria. Ability of bacteria to grow on pesticide-amended media did not always indicate compatibility with chemical seed treatments in vivo. A greenhouse study demonstrated that enhanced emergence occurred with the coryneform-like strain 44-9 on Vitavax RS treated canola seed grown under conditions favoring disease due to Rhizoctonia solani. The ability to combine plant growth promoting rhizobacterial strains with current agrichemicals for plant growth stimulation and disease control is indicated. Key words: pesticide compatibility, Pseudomonas, agrichemicals, Serratia, damping-off, plant growth promoting rhizobacteria.

scholarly journals Selenite is More Efficient than Selenate in Alleviation of Salt Stress in Lettuce Plants

2015 ◽  
Vol 57 (2) ◽  
pp. 49-54 ◽  
Author(s):  
Barbara Hawrylak-Nowak
Keyword(s):  
Salt Stress ◽  
Antioxidant Defense ◽  
Antioxidative Activity ◽  
Photosynthetic Pigment ◽  
Growth Stimulation ◽  
Promoting Effect ◽  
Induced Stress ◽  
Growth Promoting ◽  
Butterhead Lettuce ◽  
Low Selenium

Abstract There is increasing evidence showing that low selenium (Se) concentrations may increase tolerance of crop plants to several environmental stresses. The aim of this study was to compare the influence of two chemical forms of Se (selenite or selenate) at different concentrations (2 or 6 μM) on the resistance of butterhead lettuce (Lactuca sativa L. var. capitata) cv. Justyna to NaCl-induced stress (40 mM NaCl). Plant growth was negatively affected by salinity, but the level of photosynthetic pigments was not reduced. Se application at a concentration of 2 μM significantly improved the growth of salt-stressed plants, but selenite was much more effective than selenate in enhancing salt-tolerance of lettuce. The growth-promoting effect of Se was also noted at 6 μM of selenite, but did not appear at 6 μM of selenate. The beneficial effect of Se in salt-stressed lettuce could be due to antioxidative activity of Se, root system growth stimulation, and/or increase in photosynthetic pigment concentration after Se supplementation; however, it was not related to either increase in proline accumulation or reduction in foliar Na+ or Cl− concentration. These results imply that Se application, especially in the form of selenite, can enhance antioxidant defense of lettuce under salt stress, and Se supplementation may be recommended for areas of lettuce cultivation with excessive salt accumulation.

Some biological effects of volatiles emanating from wood

1970 ◽  
Vol 48 (4) ◽  
pp. 719-735 ◽  
Author(s):  
P. F. Rice
Keyword(s):  
Higher Plants ◽  
Biological Effects ◽  
Nutrient Status ◽  
Growth Stimulation ◽  
Test Organisms ◽  
Growth Promoting ◽  
Dose Levels ◽  
Fixed Period ◽  
Fungus Growth

Early in vitro observations on the biological activity of volatiles from heat-dried woods indicated two major properties: one of retarding growth of higher plants and another of stimulating growth of a wood-inhabiting Basidiomycete. For the purpose of determining the chemical nature of the active volatiles and their parent sources principally in red pine wood (Pinus resinosa), these two properties were investigated separately with the aid of bioassay techniques. Two test organisms were used: germinated kidney beans (Phaseolus vulgaris) and the fungus Fomes annosus. Various dose levels of volatile sources were suspended over the test organisms for a fixed period of time, after which growth was measured.Experimental evidence indicated that bean growth inhibition and fungus growth stimulation could be attributed to volatile autoxidation products derived from certain unsaturated fatty components of wood. In particular, linoleic acid appeared to be a major phytoactive source. A number of aliphatic aldehydes, reported in the literature as fat autoxidation products, were found to be phytotoxic to beans in appropriate quantities, but none had any growth promoting properties on the fungus. Also, indications were that fungus response to wood volatiles was largely independent of the nutrient status of the substrate, provided a suitable nutrient complement was present. It was proposed that yet unidentified non-aldehydic substances, or specific untested aldehydes, functioned as the growth factors.

Improved growth and viability of lactobacilli in the presence of Bacillus subtilis (natto), catalase, or subtilisin

2000 ◽  
Vol 46 (10) ◽  
pp. 892-897 ◽  
Author(s):  
Tomohiro Hosoi ◽  
Akio Ametani ◽  
Kan Kiuchi ◽  
Shuichi Kaminogawa
Keyword(s):  
Hydrogen Peroxide ◽  
Bacillus Subtilis ◽  
Culture Medium ◽  
Lactobacillus Reuteri ◽  
Promoting Effect ◽  
Viable Cells ◽  
Bacillus Subtilis Natto ◽  
Growth Promoting ◽  
Similar Growth

In an effort to demonstrate the potential usefulness of Bacillus subtilis (natto) as a probiotic, we examined the effect of this organism on the growth of three strains of lactobacilli co-cultured aerobically in vitro. Addition of B. subtilis (natto) to the culture medium resulted in an increase in the number of viable cells of all lactobacilli tested. Since B. subtilis (natto) can produce catalase, which has been reported to exhibit a similar growth-promoting effect on lactobacilli, we also examined the effect of bovine catalase on the growth of Lactobacillus reuteri JCM 1112 and L. acidophilus JCM 1132. Both catalase and B. subtilis (natto) enhanced the growth of L. reuteri JCM 1112, whereas B. subtilis (natto) but not catalase enhanced the growth of L. acidophilus JCM 1132. In a medium containing 0.1 mM hydrogen peroxide, its toxic effect on L. reuteri JCM 1112 was abolished by catalase or B. subtilis (natto). In addition, a serine protease from B. licheniformis, subtilisin, improved the growth and viability of L. reuteri JCM 1112 and L. acidophilus JCM 1132 in the absence of hydrogen peroxide. These results indicate that B. subtilis (natto) enhances the growth and (or) viability of lactobacilli, possibly through production of catalase and subtilisin.Key words: Bacillus subtilis (natto), Lactobacillus, probiotic, catalase, subtilisin.

Sign in / Sign up

Export Citation Format

Share Document