Improved growth of Escherichia coli in aminoglycoside antibiotics by the zor-orz toxin-antitoxin system

2021 ◽  
Author(s):  
Bikash Bogati ◽  
Nicholas Wadsworth ◽  
Francisco Barrera ◽  
Elizabeth M. Fozo
Keyword(s):  
Cell Growth ◽  
Growth Inhibition ◽  
Small Rna ◽  
Translational Control ◽  
Bacterial Species ◽  
Aminoglycoside Antibiotics ◽  
Atp Depletion ◽  
Protective Measure ◽  
Type I ◽  
Small Protein

Type I toxin-antitoxin systems consist of a small protein (under 60 amino acids) whose overproduction can result in cell growth stasis or death, and a small RNA that represses translation of the toxin mRNA. Despite their potential toxicity, type I toxin proteins are increasingly linked to improved survival of bacteria in stressful environments and antibiotic persistence. While the interaction of toxin mRNAs with their cognate antitoxin sRNAs in some systems are well characterized, additional translational control of many toxins and their biological roles are not well understood. Using an ectopic overexpression system, we show that the efficient translation of a chromosomally encoded type I toxin, ZorO, requires mRNA processing of its long 5’ untranslated region (UTR; Δ28 UTR). The severity of ZorO induced toxicity on growth inhibition, membrane depolarization, and ATP depletion were significantly increased if expressed from the Δ28 UTR versus the full-length UTR. ZorO did not form large pores as evident via a liposomal leakage assay, in vivo morphological analyses, and measurement of ATP loss. Further, increasing the copy number of the entire zor-orz locus significantly improved growth of bacterial cells in the presence of kanamycin and increased the minimum inhibitory concentration against kanamycin and gentamycin; however, no such benefit was observed against other antibiotics. This supports a role for the zor-orz locus as a protective measure against specific stress agents and is likely not part of a general stress response mechanism. Combined, these data shed more insights into the possible native functions for type I toxin proteins. IMPORTANCE Bacterial species can harbor gene pairs known as type I toxin-antitoxin systems where one gene encodes a small protein that is toxic to the bacteria producing it and a second gene that encodes a small RNA antitoxin to prevent toxicity. While artificial overproduction of type I toxin proteins can lead to cell growth inhibition and cell lysis, the endogenous translation of type I toxins appears to be tightly regulated. Here, we show translational regulation controls production of the ZorO type I toxin and prevents subsequent negative effects on the cell. Further, we demonstrate a role for zorO and its cognate antitoxin in improved growth of E. coli in the presence of aminoglycoside antibiotics.

Transforming growth factor-β1 signaling contributes to Caco-2 cell growth inhibition induced by 1,25(OH)2D3

2002 ◽  
Vol 283 (4) ◽  
pp. G864-G874 ◽  
Author(s):  
Anping Chen ◽  
Bernard H. Davis ◽  
Michael D. Sitrin ◽  
Thomas A. Brasitus ◽  
Marc Bissonnette
Keyword(s):  
Cell Growth ◽  
Growth Inhibition ◽  
Neutralizing Antibodies ◽  
Transforming Growth Factor ◽  
Type I ◽  
Inhibitory Effects ◽  
Human Colon Cancer ◽  
Growth Inhibitory ◽  
Sw480 Cells ◽  
Tgf Β1

Growth of Caco-2 and many cancer cells is inhibited by 1,25(OH)2D3. Whereas TGF-β1 inhibits normal colonic epithelial cell growth, most human colon cancer-derived cells, including Caco-2 and SW480 cells, are resistant to it. The mechanisms underlying these antiproliferative actions and resistance to TGF-β growth inhibition are largely unknown. We observed that 1,25-dihydroxyvitamin D3[1,25(OH)2D3] sensitized Caco-2 and SW480 cells to TGF-β1 growth inhibitory effects. Versus 1,25(OH)2D3 alone, the combination of 1,25(OH)2D3 and TGF-β1 significantly reduced cell numbers. Also, the amount of active TGF-β1 was increased (∼4-fold) by this secosteroid in conditioned media from Caco-2 cells. The 1,25(OH)2D3 increased the expression of IGF-II receptors (IGF-IIR), which facilitated activation of latent TGF-β1, and was found to activate TGF-β signaling in Caco-2 cells. By using neutralizing antibodies to human TGF-β1, we showed that this cytokine contributes to secosteroid-induced inhibition of Caco-2 cell growth. Also, 1,25(OH)2D3 was found to enhance the type I TGF-β receptor mRNA and protein abundance in Caco-2 cells. Whereas the 1,25(OH)2D3-induced sensitization of Caco-2 cells to TGF-β1 was IGF-IIR independent, the type I TGF-β1 receptor was required for this sensitization. Thus 1,25(OH)2D3 treatment of Caco-2 cells results in activation of latent TGF-β1, facilitated by the enhanced expression of IGF-IIR by this secosteroid. Also, 1,25(OH)2D3 sensitized Caco-2 cells to growth inhibitory effects of TGF-β1, contributing to the inhibition of Caco-2 cell growth by this secosteroid.

Jab1-siRNA Induces Cell Growth Inhibition and Cell Cycle Arrest in Gall Bladder Cancer Cells via Targeting Jab1 Signalosome

2020 ◽  
Vol 19 (16) ◽  
pp. 2019-2033 ◽  
Author(s):  
Pratibha Pandey ◽  
Mohammad H. Siddiqui ◽  
Anu Behari ◽  
Vinay K. Kapoor ◽  
Kumudesh Mishra ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Bladder Cancer ◽  
Cell Growth ◽  
Gall Bladder ◽  
Growth Inhibition ◽  
Cell Cycle Arrest ◽  
Gall Bladder Cancer ◽  
Cell Growth Inhibition ◽  
Cycle Arrest ◽  
Apoptotic Induction

Background: The aberrant alteration in Jab1 signalosome (COP9 Signalosome Complex Subunit 5) has been proven to be associated with the progression of several carcinomas. However the specific role and mechanism of action of Jab1 signalosome in carcinogenesis of gall bladder cancer (GBC) are poorly understood. Objective: The main objective of our study was to elucidate the role and mechanism of Jab1 signalosome in gall bladder cancer by employing siRNA. Methods: Jab1 overexpression was identified in gall bladder cancer tissue sample. The role of Jab1-siRNA approach in cell growth inhibition and apoptotic induction was then examined by RT-PCR, Western Blotting, MTT, ROS, Hoechst and FITC/Annexin-V staining. Results: In the current study, we have shown that overexpression of Jab1 stimulated the proliferation of GBC cells; whereas downregulation of Jab1 by using Jab1-siRNA approach resulted incell growth inhibition and apoptotic induction. Furthermore, we found that downregulation of Jab1 induces cell cycle arrest at G1 phase and upregulated the expression of p27, p53 and Bax gene. Moreover, Jab1-siRNA induces apoptosis by enhancing ROS generation and caspase-3 activation. In addition, combined treatment with Jab1-siRNA and gemicitabine demonstrated an enhanced decline in cell proliferation which further suggested increased efficacy of gemcitabine at a very lower dose (5μM) in combination with Jab1-siRNA. Conclusion: In conclusion, our study strongly suggests that targeting Jab1 signalosome could be a promising therapeutic target for the treatment of gall bladder cancer.

scholarly journals TAMI-38. CYSTEINE-PROMOTING COMPOUNDS INDUCE MITOCHONDRIAL TOXICITY IN GLIOBLASTOMA THROUGH ALTERED PYRUVATE AND SERINE METABOLISM

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii221-ii221
Author(s):  
Evan Noch ◽  
Laura Palma ◽  
Isaiah Yim ◽  
Bhavneet Binder ◽  
Elisa Benedetti ◽  
...  
Keyword(s):  
Amino Acid ◽  
Cell Growth ◽  
Growth Inhibition ◽  
Glucose Deprivation ◽  
Tumor Metabolism ◽  
Metabolic Phenotype ◽  
Low Grade ◽  
Mitochondrial Toxicity ◽  
Human Cancers ◽  
Pathway Gene

Abstract Glioblastoma (GBM) remains a poorly treatable disease with high mortality. Tumor metabolism in GBM is a critical mechanism responsible for accelerated growth because of upregulation of glucose, amino acid, and fatty acid utilization. However, little is known about the metabolic alterations that are specific to GBM and that are targetable with FDA-approved compounds. To investigate tumor metabolism signatures unique to GBM, we interrogated the TCGA and a cancer metabolite database for alterations in glucose and amino acid signatures in GBM relative to other human cancers and relative to low-grade glioma. From these analyses, we found that GBM exhibits the highest levels of cysteine and methionine pathway gene expression of 32 human cancers and that GBM exhibits high levels of cysteine-related metabolites compared to low-grade gliomas. To study the role of cysteine in GBM pathogenesis, we treated patient-derived GBM cells with a variety of FDA-approved cyst(e)ine-promoting compounds in vitro, including N-acetylcysteine (NAC) and the cephalosporin antibiotic, Ceftriaxone (CTX), which induces cystine import through System Xc transporter upregulation. Cysteine-promoting compounds, including NAC and CTX, inhibit growth of GBM cells, which is exacerbated by glucose deprivation. This growth inhibition is associated with reduced mitochondrial metabolism, manifest by reduction in ATP, NADPH/NADP+ ratio, mitochondrial membrane potential, and oxygen consumption rate. Metabolic tracing experiments with 13C6-glucose demonstrate that L-serine is rapidly depleted in GBM cells upon treatment with NAC and CTX, and exogenous serine rescues NAC- and CTX-mediated cell growth inhibition. In addition, these compounds reduce GBM mitochondrial pyruvate transport. We show that cysteine-promoting compounds reduce cell growth and induce mitochondrial toxicity in GBM, which may be due to rapid serine depletion and reduced mitochondrial pyruvate transport. This metabolic phenotype is exacerbated by glucose deprivation. This pathway is targetable with FDA-approved cysteine-promoting compounds and could synergize with glucose-lowering treatments, including the ketogenic diet, for GBM.

scholarly journals Profiling PRMT methylome reveals roles of hnRNPA1 arginine methylation in RNA splicing and cell growth

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Wen-juan Li ◽  
Yao-hui He ◽  
Jing-jing Yang ◽  
Guo-sheng Hu ◽  
Yi-an Lin ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Cell Growth ◽  
Rna Splicing ◽  
Synergistic Effects ◽  
Arginine Methylation ◽  
Type I ◽  
Prostate Cancer Cells ◽  
Cancer Cell Growth ◽  
Cancer Mutations ◽  
Substrate Spectrum

AbstractNumerous substrates have been identified for Type I and II arginine methyltransferases (PRMTs). However, the full substrate spectrum of the only type III PRMT, PRMT7, and its connection to type I and II PRMT substrates remains unknown. Here, we use mass spectrometry to reveal features of PRMT7-regulated methylation. We find that PRMT7 predominantly methylates a glycine and arginine motif; multiple PRMT7-regulated arginine methylation sites are close to phosphorylations sites; methylation sites and proximal sequences are vulnerable to cancer mutations; and methylation is enriched in proteins associated with spliceosome and RNA-related pathways. We show that PRMT4/5/7-mediated arginine methylation regulates hnRNPA1 binding to RNA and several alternative splicing events. In breast, colorectal and prostate cancer cells, PRMT4/5/7 are upregulated and associated with high levels of hnRNPA1 arginine methylation and aberrant alternative splicing. Pharmacological inhibition of PRMT4/5/7 suppresses cancer cell growth and their co-inhibition shows synergistic effects, suggesting them as targets for cancer therapy.

scholarly journals Combining Sandblasting, Alkaline Etching, and Collagen Immobilization to Promote Cell Growth on Biomedical Titanium Implants

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2550
Author(s):  
Chia-Fei Liu ◽  
Kai-Chun Chang ◽  
Ying-Sui Sun ◽  
Diem Thuy Nguyen ◽  
Her-Hsiung Huang
Keyword(s):  
Cell Growth ◽  
Type I Collagen ◽  
Bone Cells ◽  
Surface Characteristics ◽  
Attenuated Total Reflection ◽  
Titanium Implants ◽  
Type I ◽  
Alkaline Etching ◽  
Marrow Mesenchymal Stem Cells ◽  
Collagen Immobilization

Our objective in this study was to promote the growth of bone cells on biomedical titanium (Ti) implant surfaces via surface modification involving sandblasting, alkaline etching, and type I collagen immobilization using the natural cross-linker genipin. The resulting surface was characterized in terms topography, roughness, wettability, and functional groups, respectively using field emission scanning electron microscopy, 3D profilometry, and attenuated total reflection-Fourier transform infrared spectroscopy. We then evaluated the adhesion, proliferation, initial differentiation, and mineralization of human bone marrow mesenchymal stem cells (hMSCs). Results show that sandblasting treatment greatly enhanced surface roughness to promote cell adhesion and proliferation and that the immobilization of type I collagen using genipin enhanced initial cell differentiation as well as mineralization in the extracellular matrix of hMSCs. Interestingly, the nano/submicro-scale pore network and/or hydrophilic features on sandblasted rough Ti surfaces were insufficient to promote cell growth. However, the combination of all proposed surface treatments produced ideal surface characteristics suited to Ti implant applications.

scholarly journals Effect of β-carotene-rich tomato lycopene β-cyclase (tlcy-b) on cell growth inhibition in HT-29 colon adenocarcinoma cells

2008 ◽  
Vol 102 (2) ◽  
pp. 207-214 ◽  
Author(s):  
Paola Palozza ◽  
Diana Bellovino ◽  
Rossella Simone ◽  
Alma Boninsegna ◽  
Francesco Cellini ◽  
...  
Keyword(s):  
Cell Growth ◽  
Growth Inhibition ◽  
Colon Adenocarcinoma ◽  
Human Colon ◽  
Cell Growth Inhibition ◽  
Adenocarcinoma Cells ◽  
Ht 29 ◽  
Colon Adenocarcinoma Cells ◽  
Β Carotene

Lycopene β-cyclase (tlcy-b) tomatoes, obtained by modulating carotenogenesis via genetic engineering, contain a large amount of β-carotene, as clearly visible by their intense orange colour. In the present study we have subjected tlcy-b tomatoes to an in vitro simulated digestion and analysed the effects of digestate on cell proliferation. To this aim we used HT-29 human colon adenocarcinoma cells, grown in monolayers, as a model. Digested tomatoes were diluted (20 ml, 50 ml and 100 ml/l) in culture medium and added to the cells for different incubation times (24 h, 48 h and 72 h). Inhibition of cell growth by tomato digestate was dose-dependent and resulted from an arrest of cell cycle progression at the G0/G1 and G2/M phase and by apoptosis induction. A down-regulation of cyclin D1, Bcl-2 and Bcl-xl expression was observed. We also found that heat treatment of samples before digestion enhanced β-carotene release and therefore cell growth inhibition. To induce with purified β-carotene solubilised in tetrahydrofuran the same cell growth inhibition obtained with the tomato digestate, a higher amount of the carotenoid was necessary, suggesting that β-carotene micellarised during digestion is utilised more efficiently by the cells, but also that other tomato molecules, reasonably made available during digestion, may be present and cooperate with β-carotene in promoting cell growth arrest.

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