Atypical chemokine receptor 3 (ACKR3) induces the perturbation of rRNA biogenesis in colonic cells: a novel mechanism of colorectal tumorigenesis

2021 ◽  
Author(s):  
Juan Yang ◽  
Ya-Nan Li ◽  
Ting Pan ◽  
Rong-Rong Miao ◽  
Yue-Ying Zhang ◽  
...  
Keyword(s):  
Chemokine Receptor ◽  
Ribosome Biogenesis ◽  
Nuclear Translocation ◽  
Colonic Cancer ◽  
Coiled Body ◽  
Histone H2a ◽  
Colorectal Tumorigenesis ◽  
Main Regulator

Abstract Background Atypical chemokine receptor 3 (ACKR3) has emerged as a key player in several biologic processes. Its atypical “intercepting receptor” signaling properties have established ACKR3 as the main regulator in many pathophysiological processes. In this study, we investigated the mechanisms of ACKR3 in promoting Colitis and colorectal tumorigenesis. Methods ACKR3 and clinically relevant was evaluated in human colonic cancer specimens. The mechanism of ACKR3-induced perturbation of rRNA biogenesis was performed in Villin-ACKR3-IREF mice specifically expressed ACKR3 in intestines. Nuclear β-arr1 and the interaction of NOLC1 to Fibrillarin were analyzed in vitro and in vivo assays. Results Activation of ACKR3 promotes Colitis and colorectal tumorigenesis, in human and animal model, through NOLC1-induced perturbations of rRNA biogenesis. Human colonic cancer tissues demonstrated higher expression of ACKR3, and high ACKR3 expression was associated with the increased severity of Colitis and colorectal tumorigenesis. Villin-ACKR3 transgenic mice demonstrated the characteristics of ACKR3-induced colorectal cancer, showing the nuclear β-arrestin-1-activated perturbation of rRNA biogenesis. Activation of ACKR3 induced nuclear translocation of β-arrestin-1 (β-arr1), leading to the interaction of β-arr1 with nucleolar and coiled-body phosphoprotein 1 (NOLC1). As the highly phosphorylated protein in the nucleolus, NOLC1 further interacted with Fibrillarin, a conserved nucleolar methyltransferase responsible for ribosomal RNA methylation, leading to the increase of methylation in Histone H2A, resulting in the promotion of rRNA transcription of ribosome biogenesis. Conclusion ACKR3 promotes Colitis and colorectal tumorigenesis through the perturbation of rRNA biogenesis by nuclear β-arr1-induced interaction of NOLC1 with Fibrillarin.

scholarly journals ACKR3 induces the perturbation of rRNA biogenesis: a novel mechanism of colorectal tumorigenesis

2021 ◽  
Author(s):  
Xian Jun Qu ◽  
Juan Yang ◽  
Ya-Nan Li ◽  
Ting Pan ◽  
Rong-Rong Miao ◽  
...  
Keyword(s):  
Ribosomal Rna ◽  
Ribosome Biogenesis ◽  
Nuclear Translocation ◽  
Colonic Cancer ◽  
Coiled Body ◽  
Histone H2a ◽  
Neoplastic Tissue ◽  
Colorectal Tumorigenesis ◽  
Underlying Mechanisms ◽  
Cancer Tissues

Atypical chemokine receptor 3 (ACKR3) has emerged as a key player in several biologic processes. However, much less is known the underlying mechanisms of ACKR3 in promoting tumorigenesis. We found, in human and animal model, that activation of ACKR3 promotes colorectal tumorigenesis through the NOLC1-induced perturbations of rRNA biogenesis. As compared with non-neoplastic tissue, human colonic cancer tissues demonstrated higher expression of ACKR3, and high ACKR3 expression was associated with increased severity of colonic cancer. Villin-ACKR3 transgenic mice demonstrated the characteristics of ACKR3-induced colorectal cancer, showing nuclear β-arrestin-1-activated perturbation of rRNA biogenesis. Activation of ACKR3 induced nuclear translocation of β-arrestin-1 (β-arr1), leading to the interaction of β-arr1 with nucleolar and coiled-body phosphoprotein 1 (NOLC1). As the highly phosphorylated protein in the nucleolus, NOLC1 further interacted with Fibrillarin, a highly conserved nucleolar methyltransferase responsible for ribosomal RNA methylation, leading to the increase of methylation in Histone H2A, resulting in the promotion of rRNA transcription of ribosome biogenesis. Conclusion: ACKR3 promotes colorectal tumorigenesis through the perturbation of rRNA biogenesis by nuclear β-arr1-induced interaction of NOLC1 with Fibrillarin.

scholarly journals Ribosomal Protein L12 Uses a Distinct Nuclear Import Pathway Mediated by Importin 11

2002 ◽  
Vol 22 (4) ◽  
pp. 1266-1275 ◽  
Author(s):  
Scott M. Plafker ◽  
Ian G. Macara
Keyword(s):  
Ribosomal Protein ◽  
Nuclear Import ◽  
Ribosomal Proteins ◽  
Ribosome Biogenesis ◽  
Protein Import ◽  
Nuclear Translocation ◽  
Nuclear Accumulation ◽  
Transient Transfection Assay

ABSTRACT Ribosome biogenesis requires the nuclear translocation of ribosomal proteins from their site of synthesis in the cytoplasm to the nucleus. Analyses of the import mechanisms have revealed that most ribosomal proteins can be delivered to the nucleus by multiple transport receptors (karyopherins or importins). We now provide evidence that ribosomal protein L12 (rpL12) is distinguished from the bulk of ribosomal proteins because it accesses the importin 11 pathway as a major route into the nucleus. rpL12 specifically and directly interacted with importin 11 in vitro and in vivo. Both rpL12 binding to and import by importin 11 were inhibited by another importin 11 substrate, UbcM2, indicating that these two cargoes may bind overlapping sites on the transport receptor. In contrast, the import of rpL23a, a ribosomal protein that uses the general ribosomal protein import system, was not competed by UbcM2, and in an in vitro binding assay, importin 11 did not bind to the nuclear localization signal of rpL23a. Furthermore, in a transient transfection assay, the nuclear accumulation of rpL12 was increased by coexpressed importin 11, but not by other importins. These data are consistent with importin 11 being a mediator of rpL12 nuclear import. Taken together, these results indicate that rpL12 uses a distinct nuclear import pathway that may contribute to a mechanism for regulating ribosome synthesis and/or maturation.

scholarly journals Inhibition of RANKL-Induced Osteoclastogenesis by Novel Mutant RANKL

2021 ◽  
Vol 22 (1) ◽  
pp. 434
Author(s):  
Yuria Jang ◽  
Hong Moon Sohn ◽  
Young Jong Ko ◽  
Hoon Hyun ◽  
Wonbong Lim
Keyword(s):  
Nuclear Translocation ◽  
Critical Role ◽  
Osteoclast Differentiation ◽  
Point Mutations ◽  
Tartrate Resistant Acid Phosphatase ◽  
Mice Model ◽  
Gsk 3Β ◽  
Rank Signaling

Background: Recently, it was reported that leucine-rich repeat-containing G-protein-coupled receptor 4 (LGR4, also called GPR48) is another receptor for RANKL and was shown to compete with RANK to bind RANKL and suppress canonical RANK signaling during osteoclast differentiation. The critical role of the protein triad RANK–RANKL in osteoclastogenesis has made their binding an important target for the development of drugs against osteoporosis. In this study, point-mutations were introduced in the RANKL protein based on the crystal structure of the RANKL complex and its counterpart receptor RANK, and we investigated whether LGR4 signaling in the absence of the RANK signal could lead to the inhibition of osteoclastogenesis.; Methods: The effects of point-mutated RANKL (mRANKL-MT) on osteoclastogenesis were assessed by tartrate-resistant acid phosphatase (TRAP), resorption pit formation, quantitative real-time polymerase chain reaction (qPCR), western blot, NFATc1 nuclear translocation, micro-CT and histomorphological assay in wild type RANKL (mRANKL-WT)-induced in vitro and in vivo experimental mice model. Results: As a proof of concept, treatment with the mutant RANKL led to the stimulation of GSK-3β phosphorylation, as well as the inhibition of NFATc1 translocation, mRNA expression of TRAP and OSCAR, TRAP activity, and bone resorption, in RANKL-induced mouse models; and Conclusions: The results of our study demonstrate that the mutant RANKL can be used as a therapeutic agent for osteoporosis by inhibiting RANKL-induced osteoclastogenesis via comparative inhibition of RANKL. Moreover, the mutant RANKL was found to lack the toxic side effects of most osteoporosis treatments.

scholarly journals Phaseolin Attenuates Lipopolysaccharide-Induced Inflammation in RAW 264.7 Cells and Zebrafish

Biomedicines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 420
Author(s):  
Su-Jung Hwang ◽  
Ye-Seul Song ◽  
Hyo-Jong Lee
Keyword(s):  
Nitric Oxide ◽  
Nuclear Translocation ◽  
Raw 264.7 Cells ◽  
Network Pharmacology ◽  
Raw 264.7 ◽  
Dependent Manner ◽  
Bioactive Constituents

Kushen (Radix Sophorae flavescentis) is used to treat ulcerative colitis, tumors, and pruritus. Recently, phaseolin, formononetin, matrine, luteolin, and quercetin, through a network pharmacology approach, were tentatively identified as five bioactive constituents responsible for the anti-inflammatory effects of S. flavescentis. However, the role of phaseolin (one of the primary components of S. flavescentis) in the direct regulation of inflammation and inflammatory processes is not well known. In this study, the beneficial role of phaseolin against inflammation was explored in lipopolysaccharide (LPS)-induced inflammation models of RAW 264.7 macrophages and zebrafish larvae. Phaseolin inhibited LPS-mediated production of nitric oxide (NO) and the expression of inducible nitric oxide synthase (iNOS), without affecting cell viability. In addition, phaseolin suppressed pro-inflammatory mediators such as cyclooxygenase 2 (COX-2), interleukin-1β (IL-1β), tumor necrosis factor α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), and interleukin-6 (IL-6) in a dose-dependent manner. Furthermore, phaseolin reduced matrix metalloproteinase (MMP) activity as well as macrophage adhesion in vitro and the recruitment of leukocytes in vivo by downregulating Ninjurin 1 (Ninj1), an adhesion molecule. Finally, phaseolin inhibited the nuclear translocation of nuclear factor-kappa B (NF-κB). In view of the above, our results suggest that phaseolin could be a potential therapeutic candidate for the management of inflammation.

scholarly journals LINGO-1 shRNA protects the brain against ischemia/reperfusion injury by inhibiting the activation of NF-κB and JAK2/STAT3

Human Cell ◽  
2021 ◽  
Author(s):  
Jiaying Zhu ◽  
Zhu Zhu ◽  
Yipin Ren ◽  
Yukang Dong ◽  
Yaqi Li ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Nuclear Translocation ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Mice Model ◽  
Down Regulation

AbstractLINGO-1 may be involved in the pathogenesis of cerebral ischemia. However, its biological function and underlying molecular mechanism in cerebral ischemia remain to be further defined. In our study, middle cerebral artery occlusion/reperfusion (MACO/R) mice model and HT22 cell oxygen–glucose deprivation/reperfusion (OGD/R) were established to simulate the pathological process of cerebral ischemia in vivo and in vitro and to detect the relevant mechanism. We found that LINGO-1 mRNA and protein were upregulated in mice and cell models. Down-regulation LINGO-1 improved the neurological symptoms and reduced pathological changes and the infarct size of the mice after MACO/R. In addition, LINGO-1 interference alleviated apoptosis and promoted cell proliferation in HT22 of OGD/R. Moreover, down-regulation of LINGO-1 proved to inhibit nuclear translocation of p-NF-κB and reduce the expression level of p-JAK2 and p-STAT3. In conclusion, our data suggest that shLINGO-1 attenuated ischemic injury by negatively regulating NF-KB and JAK2/STAT3 pathways, highlighting a novel therapeutic target for ischemic stroke.

scholarly journals RIP3 impedes transcription factor EB to suppress autophagic degradation in septic acute kidney injury

2021 ◽  
Vol 12 (6) ◽  
Author(s):  
Ruizhao Li ◽  
Xingchen Zhao ◽  
Shu Zhang ◽  
Wei Dong ◽  
Li Zhang ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
Transcription Factor ◽  
Nuclear Translocation ◽  
Kidney Injury ◽  
Septic Acute Kidney Injury ◽  
Transcription Factor Eb ◽  
Autophagic Degradation ◽  
Lps Treatment

AbstractAutophagy is an important renal-protective mechanism in septic acute kidney injury (AKI). Receptor interacting protein kinase 3 (RIP3) has been implicated in the renal tubular injury and renal dysfunction during septic AKI. Here we investigated the role and mechanism of RIP3 on autophagy in septic AKI. We showed an activation of RIP3, accompanied by an accumulation of the autophagosome marker LC3II and the autophagic substrate p62, in the kidneys of lipopolysaccharide (LPS)-induced septic AKI mice and LPS-treated cultured renal proximal tubular epithelial cells (PTECs). The lysosome inhibitor did not further increase the levels of LCII or p62 in LPS-treated PTECs. Moreover, inhibition of RIP3 attenuated the aberrant accumulation of LC3II and p62 under LPS treatment in vivo and in vitro. By utilizing mCherry-GFP-LC3 autophagy reporter mice in vivo and PTECs overexpression mRFP-GFP-LC3 in vitro, we observed that inhibition of RIP3 restored the formation of autolysosomes and eliminated the accumulated autophagosomes under LPS treatment. These results indicated that RIP3 impaired autophagic degradation, contributing to the accumulation of autophagosomes. Mechanistically, the nuclear translocation of transcription factor EB (TFEB), a master regulator of the lysosome and autophagy pathway, was inhibited in LPS-induced mice and LPS-treated PTECs. Inhibition of RIP3 restored the nuclear translocation of TFEB in vivo and in vitro. Co-immunoprecipitation further showed an interaction of RIP3 and TFEB in LPS-treated PTECs. Also, the expression of LAMP1 and cathepsin B, two potential target genes of TFEB involved in lysosome function, were decreased under LPS treatment in vivo and in vitro, and this decrease was rescued by inhibiting RIP3. Finally, overexpression of TFEB restored the autophagic degradation in LPS-treated PTECs. Together, the present study has identified a pivotal role of RIP3 in suppressing autophagic degradation through impeding the TFEB-lysosome pathway in septic AKI, providing potential therapeutic targets for the prevention and treatment of septic AKI.

scholarly journals Dephosphorylation of the C-terminal Tyrosyl Residue of the DNA Damage-related Histone H2A.X Is Mediated by the Protein Phosphatase Eyes Absent

2009 ◽  
Vol 284 (24) ◽  
pp. 16066-16070 ◽  
Author(s):  
Navasona Krishnan ◽  
Dae Gwin Jeong ◽  
Suk-Kyeong Jung ◽  
Seong Eon Ryu ◽  
Andrew Xiao ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Damage Response ◽  
Mammalian Cells ◽  
Protein Tyrosine Phosphatases ◽  
Histone H2a ◽  
Eyes Absent ◽  
Damage Repair ◽  
Damage Response

In mammalian cells, the DNA damage-related histone H2A variant H2A.X is characterized by a C-terminal tyrosyl residue, Tyr-142, which is phosphorylated by an atypical kinase, WSTF. The phosphorylation status of Tyr-142 in H2A.X has been shown to be an important regulator of the DNA damage response by controlling the formation of γH2A.X foci, which are platforms for recruiting molecules involved in DNA damage repair and signaling. In this work, we present evidence to support the identification of the Eyes Absent (EYA) phosphatases, protein-tyrosine phosphatases of the haloacid dehalogenase superfamily, as being responsible for dephosphorylating the C-terminal tyrosyl residue of histone H2A.X. We demonstrate that EYA2 and EYA3 displayed specificity for Tyr-142 of H2A.X in assays in vitro. Suppression of eya3 by RNA interference resulted in elevated basal phosphorylation and inhibited DNA damage-induced dephosphorylation of Tyr-142 of H2A.X in vivo. This study provides the first indication of a physiological substrate for the EYA phosphatases and suggests a novel role for these enzymes in regulation of the DNA damage response.

Role of the ligand in intracellular receptor function: receptor affinity determines activation in vitro of the latent dioxin receptor to a DNA-binding form

1991 ◽  
Vol 11 (1) ◽  
pp. 401-411
Author(s):  
S Cuthill ◽  
A Wilhelmsson ◽  
L Poellinger
Keyword(s):  
Dna Binding ◽  
Cellular Response ◽  
Molecular Mechanisms ◽  
Nuclear Translocation ◽  
Rank Order ◽  
Receptor Ligands ◽  
Free System ◽  
Dioxin Receptor

To reconstitute the molecular mechanisms underlying the cellular response to soluble receptor ligands, we have exploited a cell-free system that exhibits signal- (dioxin-)induced activation of the latent cytosolic dioxin receptor to an active DNA-binding species. The DNA-binding properties of the in vitro-activated form were qualitatively indistinguishable from those of in vivo-activated nuclear receptor extracted from dioxin-treated cells. In vitro activation of the receptor by dioxin was dose dependent and was mimicked by other dioxin receptor ligands in a manner that followed the rank order of their relative affinities for the receptor in vitro and their relative potencies to induce target gene transcription in vivo. Thus, in addition to triggering the initial release of inhibition of DNA binding and presumably allowing nuclear translocation, the ligand appears to play a crucial role in the direct control of the level of functional activity of a given ligand-receptor complex.

Pharmacological Blocker of NF-κb and Mitochondrial Ros Restrict NLRP3 Inflammasome Activation and Rescue Dopaminergic Neurons in Vitro and in Vivo Parkinson’s Disease

2021 ◽  
Author(s):  
Sahabuddin Ahmed ◽  
Samir Ranjan Panda ◽  
Mohit Kwatra ◽  
Bidya Dhar Sahu ◽  
VGM Naidu
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Free Radicals ◽  
Nlrp3 Inflammasome ◽  
Nuclear Translocation ◽  
Inflammasome Activation ◽  
Mitochondrial Ros ◽  
Nlrp3 Inflammasome Activation

Abstract Several activators of NLRP3 inflammasome have been described; however, the central mechanisms of NLRP3 inflammasome activation in brain microglia, especially at the activating step through free radical generation, still require further clarification. Hence the present study aimed to investigate the role of free radicals in activating NLRP3 inflammasome driven neurodegeneration and elucidated the neuroprotective role of perillyl alcohol (PA) in vitro and in vivo models of Parkinson’s disease. Initial priming of microglial cells with lipopolysaccharide (LPS) following treatment with hydrogen peroxide (H2O2) induces NF-κB translocation to nucleus with robust generation of free radicals that act as Signal 2 in augmenting NLRP3 inflammasome assembly and its downstream targets. PA treatment suppresses nuclear translocation of NF-κB and maintains cellular redox homeostasis in microglia that limits NLRP3 inflammasome activation along with processing active caspase-1, IL-1β and IL-18. To further correlates the in vitro study with in vivo MPTP model, treatment with PA also inhibits the nuclear translocation of NF-κB and downregulates the NLRP3 inflammasome activation. PA administration upregulates various antioxidant enzymes levels and restored the level of dopamine and other neurotransmitters in the striatum of the mice brain with improved behavioural activities. Additionally, treatment with Mito-TEMPO (a mitochondrial ROS inhibitor) was also seen to inhibit NLRP3 inflammasome and rescue dopaminergic neuron loss in the mice brain. Therefore, we conclude that NLRP3 inflammasome activation requires a signal from damaged mitochondria for its activation. Further pharmacological scavenging of free radicals restricts microglia activation and simultaneously supports neuronal survival via targeting NLRP3 inflammasome pathway in Parkinson’s disease.

scholarly journals Formation of a Complex between Nucleolin and Replication Protein a after Cell Stress Prevents Initiation of DNA Replication

2000 ◽  
Vol 149 (4) ◽  
pp. 799-810 ◽  
Author(s):  
Yaron Daniely ◽  
James A. Borowiec
Keyword(s):  
Dna Replication ◽  
Ribosome Biogenesis ◽  
Protein A ◽  
Simian Virus 40 ◽  
Replication Protein A ◽  
Cell Stress ◽  
Replication Protein ◽  
Binding Studies

We used a biochemical screen to identify nucleolin, a key factor in ribosome biogenesis, as a high-affinity binding partner for the heterotrimeric human replication protein A (hRPA). Binding studies in vitro demonstrated that the two proteins physically interact, with nucleolin using an unusual contact with the small hRPA subunit. Nucleolin significantly inhibited both simian virus 40 (SV-40) origin unwinding and SV-40 DNA replication in vitro, likely by nucleolin preventing hRPA from productive interaction with the SV-40 initiation complex. In vivo, use of epifluorescence and confocal microscopy showed that heat shock caused a dramatic redistribution of nucleolin from the nucleolus to the nucleoplasm. Nucleolin relocalization was concomitant with a tenfold increase in nucleolin–hRPA complex formation. The relocalized nucleolin significantly overlapped with the position of hRPA, but only poorly with sites of ongoing DNA synthesis. We suggest that the induced nucleolin–hRPA interaction signifies a novel mechanism that represses chromosomal replication after cell stress.

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