scholarly journals A novel mode of control of nickel uptake by a multifunctional metallochaperone

2021 ◽  
Vol 17 (1) ◽  
pp. e1009193
Author(s):  
Milica Denic ◽  
Evelyne Turlin ◽  
Valérie Michel ◽  
Frédéric Fischer ◽  
Mozhgan Khorasani-Motlagh ◽  
...  
Keyword(s):  
Metal Binding ◽  
Translational Regulation ◽  
Acid Resistance ◽  
Transcriptional Level ◽  
Ppiase Activity ◽  
Metal Transporters ◽  
Nickel Uptake

Cellular metal homeostasis is a critical process for all organisms, requiring tight regulation. In the major pathogen Helicobacter pylori, the acquisition of nickel is an essential virulence determinant as this metal is a cofactor for the acid-resistance enzyme, urease. Nickel uptake relies on the NixA permease and the NiuBDE ABC transporter. Till now, bacterial metal transporters were reported to be controlled at their transcriptional level. Here we uncovered post-translational regulation of the essential Niu transporter in H. pylori. Indeed, we demonstrate that SlyD, a protein combining peptidyl-prolyl isomerase (PPIase), chaperone, and metal-binding properties, is required for the activity of the Niu transporter. Using two-hybrid assays, we found that SlyD directly interacts with the NiuD permease subunit and identified a motif critical for this contact. Mutants of the different SlyD functional domains were constructed and used to perform in vitro PPIase activity assays and four different in vivo tests measuring nickel intracellular accumulation or transport in H. pylori. In vitro, SlyD PPIase activity is down-regulated by nickel, independently of its C-terminal region reported to bind metals. In vivo, a role of SlyD PPIase function was only revealed upon exposure to high nickel concentrations. Most importantly, the IF chaperone domain of SlyD was shown to be mandatory for Niu activation under all in vivo conditions. These data suggest that SlyD is required for the active functional conformation of the Niu permease and regulates its activity through a novel mechanism implying direct protein interaction, thereby acting as a gatekeeper of nickel uptake. Finally, in agreement with a central role of SlyD, this protein is essential for the colonization of the mouse model by H. pylori.

Abstract 12880: Up-Regulation of Microrna-208b Contributes to Diabetic Myocardial Fibrosis in Mouse

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Zhi Xin Shan ◽  
Lin lin Guo ◽  
Jie ning Zhu ◽  
Qiu xiong Lin ◽  
Chun yu Deng ◽  
...  
Keyword(s):  
Myocardial Fibrosis ◽  
Recombinant Adenovirus ◽  
Cardiac Fibroblasts ◽  
Transcriptional Level ◽  
Dependent Manner ◽  
Genes Expression ◽  
Diabetic Myocardium

MicroRNAs play important roles in myocardial fibrosis during diabetic cardiomyopathy. The present study aimed to investigate the role of microRNA-208b (miR-208b) in diabetic myocardial fibrosis. Compared to the db/m control mice, Smad3 was activated , fibrosis-related genes expression were significantly up-regulated, and miRNAs were dysregulated in the myocardium of the 16-week-old diabetic db/db mice. miR-208b was confirmed up-regulated in the db/db diabetic myocardium in vivo and in mouse cardiomyocytes and cardiac fibroblasts after treatment with Ang-II, TGF-β and high glucose/glucose oxidase (HG/Go) in vitro , respectively. By using recombinant adenovirus expressing CD63-GFP, rAd-CD63-GFP, we infected neonatal mouse cardiomyocytes with rAd-CD63-GFP and tracked the secreted exosomes with GFP. We found that miR-208b was increased in the secreted exosomes from HG/Go-treated cardiomyocytes, and the exosomes with increased miR-208b could enhance fibrosis associated Col1a1, α-SMA and CTGF expressions in cardiac fibroblasts. Transfection of miR-208b mimic could increase Col1a1, α-SMA and CTGF expression in a dose-dependent manner in cardiac fibroblasts. However, blockage of miR-208b could inhibit fibrosis related genes expression. Mtf2 and Pgrmc1 were verified modulated by miR-208b at post transcriptional level in vitro . Consistently, Mtf2 and Pgrmc1 expressions were decreased in the diabetic myocardium, and knockdown of Mtf2 or Pgrmc1could increase fibrosis related genes expression in cardiac fibroblasts. Smad3 inhibitor, Naringenin, could dramatically inhibit miR-208b expression in cardiac fibroblasts. Taken together, we demonstrated that miR-208b was up-regulated in diabetic fibrotic myocardium, Mtf2 and Pgrmc1 mediated the effect of miR-208b on enhancing Col1a1, α-SMA and CTGF expression in diabetic myocardial fibrosis.

scholarly journals Targeting miR-18a sensitizes chondrocytes to anticytokine therapy to prevent osteoarthritis progression

2020 ◽  
Vol 11 (11) ◽  
Author(s):  
Chengjie Lian ◽  
Tianyu Tao ◽  
Peiqiang Su ◽  
Zhiheng Liao ◽  
Xudong Wang ◽  
...  
Keyword(s):  
Inflammatory Factors ◽  
Transcriptional Level ◽  
Inhibitory Effects ◽  
Osteoarthritis Progression ◽  
Anticytokine Therapy ◽  
Potential Strategy ◽  
Underlying Inflammation

Abstract Inflammation participates in the development of OA and targeting inflammatory signaling pathways is a potential strategy for OA treatment. IL-1β is one of the most important inflammatory factors to trigger the activation of NF-κB signaling and accelerate OA progression, whereas OA patients could hardly benefit from inhibiting IL-1β in clinic, suggesting the importance to further explore the details of OA inflammation. We here showed that expression of miR-18a in chondrocytes was specifically induced in response to IL-1β in vitro as well as in rat model of OA during which NF-κB signaling was involved, and that nuclear-translocated p65 directly upregulated miR-18a expression at transcriptional level. Further, increased miR-18a mediated hypertrophy of chondrocytes, resulting in OA degeneration, by targeting TGFβ1, SMAD2, and SMAD3 and subsequently leading to repression of TGF-β signaling. And the level of serum miR-18a was positively correlated to severity of OA. Interestingly, other than IL-1β, pro-inflammation cytokines involving TNFα could also remarkably upregulate miR-18a via activating NF-κB signaling and subsequently induce chondrocytes hypertrophy, suggesting a pivotal central role of miR-18a in inflammatory OA progression. Thus, our study revealed a novel convergence of NF-κB and TGF-β signaling mediated by miR-18a, and a novel mechanism underlying inflammation-regulated OA dependent of NF-κB/miR-18a/TGF-β axis. Notably, in vivo assay showed that targeting miR-18a sensitized OA chondrocytes to IL-1β inhibitor as targeting IL-1β and miR-18a simultaneously had much stronger inhibitory effects on OA progression than suppressing IL-1β alone. Therefore, the diagnostic and therapeutic potentials of miR-18a for OA were also revealed.

scholarly journals LncRNA TUG1 sponges miR-204-5p to promote osteoblast differentiation through upregulating Runx2 in aortic valve calcification

2017 ◽  
Vol 114 (1) ◽  
pp. 168-179 ◽  
Author(s):  
Cong Yu ◽  
Lifu Li ◽  
Fei Xie ◽  
Shichao Guo ◽  
Fayuan Liu ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Osteoblast Differentiation ◽  
Vital Role ◽  
Transcriptional Level ◽  
Calcific Aortic Valve Disease ◽  
Mirna Sponge ◽  
Lncrna Tug1

Abstract Aims Emerging evidence indicates that long non-coding RNAs (lncRNAs) play a vital role in cardiovascular physiology and pathology. Although the lncRNA TUG1 is implicated in atherosclerosis, its function in calcific aortic valve disease (CAVD) remains unknown. Methods and results In this study, we found that TUG1 was highly expressed in human aortic valves and primary valve interstitial cells (VICs). Moreover, TUG1 knockdown induced inhibition of osteoblast differentiation in CAVD both in vitro and in vivo. Mechanistically, silencing of TUG1 increased the expression of miR-204-5p and subsequently inhibited Runx2 expression at the post-transcriptional level. Importantly, TUG1 directly interacted with miR-204-5p and downregulation of miR-204-5p efficiently reversed the suppression of Runx2 induced by TUG1 short hairpin RNA (shRNA). Thus, TUG1 positively regulated the expression of Runx2, through sponging miR-204-5p, and promoted osteogenic differentiation in CAVD. Conclusion All together, the evidence generated by our study elucidates the role of lncRNA TUG1 as a miRNA sponge in CAVD, and sheds new light on lncRNA-directed diagnostics and therapeutics in CAVD.

scholarly journals The UreEF Fusion Protein Provides a Soluble and Functional Form of the UreF Urease Accessory Protein

2006 ◽  
Vol 188 (24) ◽  
pp. 8413-8420 ◽  
Author(s):  
Jong Kyong Kim ◽  
Scott B. Mulrooney ◽  
Robert P. Hausinger
Keyword(s):  
Fusion Protein ◽  
Metal Binding ◽  
Accessory Proteins ◽  
Wild Type ◽  
Binding Properties ◽  
C Terminus ◽  
Urease Accessory Protein

ABSTRACT Four accessory proteins (UreD, UreE, UreF, and UreG) are typically required to form the nickel-containing active site in the urease apoprotein (UreABC). Among the accessory proteins, UreD and UreF have been elusive targets for biochemical and structural characterization because they are not overproduced as soluble proteins. Using the best-studied urease system, in which the Klebsiella aerogenes genes are expressed in Escherichia coli, a translational fusion of ureE and ureF was generated. The UreEF fusion protein was overproduced as a soluble protein with a convenient tag involving the His-rich region of UreE. The fusion protein was able to form a UreD(EF)G-UreABC complex and to activate urease in vivo, and it interacted with UreD-UreABC in vitro to form a UreD(EF)-UreABC complex. While the UreF portion of UreEF is fully functional, the fusion significantly affected the role of the UreE portion by interrupting its dimerization and altering its metal binding properties compared to those of the wild-type UreE. Analysis of a series of UreEF deletion mutants revealed that the C terminus of UreF is required to form the UreD(EF)G-UreABC complex, while the N terminus of UreF is essential for activation of urease.

scholarly journals C1QBP regulates apoptosis of renal cell carcinoma via modulating xanthine dehydrogenase (XDH) mediated ROS generation

2020 ◽  
Author(s):  
Yiting Wang ◽  
Qiqi Cui ◽  
Chao Wang ◽  
Shuang Liu ◽  
Runxuan Du ◽  
...  
Keyword(s):  
Renal Cell Carcinoma ◽  
Cell Carcinoma ◽  
Renal Cell ◽  
Xanthine Dehydrogenase ◽  
Ros Generation ◽  
Transcriptional Level ◽  
Fuhrman Grade

Abstract Background Complement component 1 Q subcomponent binding protein (C1QBP) is a multifunctional protein and plays a vital role in the progression and metabolism of cancer. Our previous study has revealed that the low expression of C1QBP in renal cell carcinoma (RCC) and knockdown of C1QBP promotes the adhesion and invasion of RCC cells. However, its functions in the metabolism, oxidative stress and apoptosis of RCC cells have not yet been explored. Methods Metabolomics assay was applied to investigate the role of C1QBP in RCC metabolism. C1QBP knockdown and overexpression cells were established via lentiviral infection and subjected to apoptosis and ROS assay in vitro. RNA stability assay and pre-mRNA detection were applied to characterize the mechanism of C1QBP regulating XDH transcription. In vivo, orthotopic tumor xenografts assay was performed to investigate the role of C1QBP progression. Results Metabolomics investigations revealed that C1QBP dramatically diminished the hypoxanthine content in RCC cells. C1QBP promoted the mRNA and protein expression of hypoxanthine catabolic enzyme xanthine dehydrogenase (XDH). Meanwhile, C1QBP regulated the expression of XDH gene at the pre-transcriptional level by regulating XDH transcriptional stimulators IL-6, TNF-α and IFN-γ. Moreover, the expression of C1QBP and XDH was lower in RCC tumors compared with the para-tumor normal tissues, and their down-regulation was associated with higher levels of Fuhrman grade. In RCC cells, C1QBP significantly increased produces reactive oxygen species (ROS) levels, apoptosis, and the expression of apoptotic proteins cleaved caspase-3 and bax/bcl2 via regulating XDH.Conclusions C1QBP promotes the catabolism of hypoxanthine and elevates the apoptosis of RCC cells by modulating XDH-mediated ROS generation.

scholarly journals Circ-GALNT16 restrains colorectal cancer progression by enhancing the SUMOylation of hnRNPK

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Chaofan Peng ◽  
Yuqian Tan ◽  
Peng Yang ◽  
Kangpeng Jin ◽  
Chuan Zhang ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Dna Binding ◽  
Rna Sequencing ◽  
Cancer Progression ◽  
Transcriptional Level ◽  
Binding Ability ◽  
Transcriptional Complex

Abstract Background Recent studies have investigated the role of circular RNAs (circRNAs) as significant regulatory factors in multiple cancer progression. Nevertheless, the biological functions of circRNAs and the underlying mechanisms by which they regulate colorectal cancer (CRC) progression remain unclear. Methods A novel circRNA (circ-GALNT16) was identified by microarray and qRT-PCR. A series of in vitro and in vivo phenotype experiments were performed to investigate the role of circ-GALNT16 in CRC. The FISH, RNA pulldown assay, RIP assay, RNA sequencing, coimmunoprecipitation, and ChIP were performed to investigate the molecular mechanisms of circ-GALNT16 in CRC progression. Results Circ-GALNT16 was downregulated in CRC and was negatively correlated with poor prognosis. Circ-GALNT16 suppressed the proliferation and metastatic ability of CRC cells in vitro and in vivo. Mechanistically, circ-GALNT16 could bind to the KH3 domain of heterogeneous nuclear ribonucleoprotein K (hnRNPK), which promoted the SUMOylation of hnRNPK. Additionally, circ-GALNT16 could enhance the formation of the hnRNPK-p53 complex by facilitating the SUMOylation of hnRNPK. RNA sequencing assay identified serpin family E member 1 as the target gene of circ-GALNT16 at the transcriptional level. Rescue assays revealed that circ-GALNT16 regulated the expression of Serpine1 by inhibiting the deSUMOylation of hnRNPK mediated by SUMO-specific peptidase 2 and then regulating the sequence-specific DNA binding ability of the hnRNPK-p53 transcriptional complex. Conclusions Circ-GALNT16 suppressed CRC progression by inhibiting Serpine1 expression through regulating the sequence-specific DNA binding ability of the SENP2-mediated hnRNPK-p53 transcriptional complex and might function as a biomarker and therapeutic target for CRC.

scholarly journals In Situ Characterization of Hfq Bacterial Amyloid: A Fourier-Transform Infrared Spectroscopy Study

Pathogens ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 36 ◽  
Author(s):  
David Partouche ◽  
Valeria Militello ◽  
Andrea Gomez-Zavaglia ◽  
Frank Wien ◽  
Christophe Sandt ◽  
...  
Keyword(s):  
Self Assembly ◽  
Transcriptional Level ◽  
In Situ Characterization ◽  
Bacterial Adaptation ◽  
Amyloid A

Hfq is a bacterial protein that regulates gene expression at the post-transcriptional level in Gram-negative bacteria. We have previously shown that Escherichia coli Hfq protein, and more precisely its C-terminal region (CTR), self-assembles into an amyloid-like structure in vitro. In the present work, we present evidence that Hfq unambiguously forms amyloid structures also in vivo. Taking into account the role of this protein in bacterial adaptation and virulence, our work opens possibilities to target Hfq amyloid self-assembly and cell location, with important potential to block bacterial adaptation and treat infections.

Suppression of miRNA let-7i-5p promotes cardiomyocyte proliferation and repairs heart function post injury by targetting CCND2 and E2F2

2019 ◽  
Vol 133 (3) ◽  
pp. 425-441 ◽  
Author(s):  
Yinlan Hu ◽  
Guoqing Jin ◽  
Bing Li ◽  
Yanmei Chen ◽  
Lintao Zhong ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Therapeutic Strategy ◽  
Heart Function ◽  
Terminal Differentiation ◽  
Transcriptional Level ◽  
Cardiomyocyte Proliferation ◽  
Post Injury

Abstract MiRNAs regulate the cardiomyocyte (CM) cell cycle at the post-transcriptional level, affect cell proliferation, and intervene in harmed CM repair post-injury. The present study was undertaken to characterize the role of let-7i-5p in the processes of CM cell cycle and proliferation and to reveal the mechanisms thereof. In the present study, we used real-time qPCR (RT-qPCR) to determine the up-regulated let-7i-5p in CMs during the postnatal switch from proliferation to terminal differentiation and further validated the role of let-7i-5p by loss- and gain-of-function of let-7i-5p in CMs in vitro and in vivo. We found that the overexpression of let-7i-5p inhibited CM proliferation, whereas the suppression of let-7i-5p significantly facilitated CM proliferation. E2F2 and CCND2 were identified as the targets of let-7i-5p, mediating its effect in regulating the cell cycle of CMs. Supperession of let-7i-5p promoted the recovery of heart function post-myocardial infarction by enhancing E2F2 and CCND2. Collectively, our results revealed that let-7i-5p is involved in the regulation of the CM cell cycle and further impacts proliferation, which may offer a new potential therapeutic strategy for cardiac repair after ischemic injury.

The Role of Polyphenols in the Modulation of Plasma Non-Enzymatic Antioxidant Capacity (NEAC)

2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito
Keyword(s):  
Antioxidant Capacity ◽  
Dietary Intervention ◽  
Ex Vivo ◽  
The Body ◽  
Dietary Polyphenols ◽  
Enzymatic Antioxidant ◽  
Endogenous Antioxidant

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.

Anti-obesity role of Aster glehni extract: in vivo and in vitro effects

Planta Medica ◽  
2012 ◽  
Vol 78 (11) ◽  
Author(s):  
HM Lee ◽  
TG Ahn ◽  
CW Kim ◽  
HJ An
Keyword(s):  
In Vitro Effects
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