The scaffold protein IB1/JIP-1 controls the activation of JNK in rat stressed urothelium

2002 ◽  
Vol 115 (2) ◽  
pp. 385-393
Author(s):  
Thomas Tawadros ◽  
Andrea Formenton ◽  
Jean Dudler ◽  
Nancy Thompson ◽  
Pascal Nicod ◽  
...  
Keyword(s):  
Critical Role ◽  
In Situ Hybridisation ◽  
Outlet Obstruction ◽  
Scaffold Protein ◽  
Viral Gene ◽  
Urothelial Cells ◽  
Urine Retention ◽  
Jnk Pathway ◽  
Jnk Activation

The c-Jun N-terminal kinase (JNK) is critical for cell survival, differentiation, apoptosis and tumorigenesis. This signalling pathway requires the presence of the scaffold protein Islet-Brain1/c-Jun N-terminal kinase interacting protein-1 (IB1/JIP-1). Immunolabeling and in situ hybridisation of bladder sections showed that IB1/JIP-1 is expressed in urothelial cells. The functional role of IB1/JIP-1 in the urothelium was therefore studied in vivo in a model of complete rat bladder outlet obstruction. This parietal stress, which is due to urine retention, reduced the content of IB1/JIP-1 in urothelial cells and consequently induced a drastic increase in JNK activity and AP-1 binding activity. Using a viral gene transfer approach, the stress-induced activation of JNK was prevented by overexpressing IB1/JIP-1. Conversely, the JNK activity was increased in urothelial cells where the IB1/JIP-1 content was experimentally reduced using an antisense RNA strategy. Furthermore, JNK activation was found to be increased in non-stressed urothelial cells of heterozygous mice carrying a selective disruption of the IB1/JIP-1 gene. These data established that mechanical stress in urothelial cells in vivo induces a robust JNK activation as a consequence of regulated expression of the scaffold protein IB1/JIP-1. This result highlights a critical role for that scaffold protein in the homeostasis of the urothelium and unravels a new potential target to regulate the JNK pathway in this tissue.

scholarly journals Inhibition of JNK activation prolongs survival after smoke inhalation from fires

2007 ◽  
Vol 292 (4) ◽  
pp. L984-L991 ◽  
Author(s):  
Olga L. Syrkina ◽  
Deborah A. Quinn ◽  
Walter Jung ◽  
Bin Ouyang ◽  
Charles A. Hales
Keyword(s):  
Lung Injury ◽  
Critical Role ◽  
Inflammatory Cells ◽  
Smoke Inhalation ◽  
Sprague Dawley ◽  
Jnk Pathway ◽  
Initial Injury ◽  
Acute Inflammatory Cell ◽  
Jnk Activation

Initial injury from smoke inhalation is mainly to the trachea and bronchi and is characterized by mucosal hyperemia and increased microvascular permeability, exfoliation of epithelial lining, mucous secretion, mucous plugging, and an acute inflammatory cell influx. In this study, we explore the role of the c-Jun N-terminal protein kinase (JNK) pathway in smoke inhalation lung injury using a rat model of exposure to smoke from burning cotton. Male Sprague-Dawley rats were exposed to smoke from burning cotton for 15 min, and 1 h after injury a JNK inhibitor (SP-600125) or vehicle was injected. We measured neutrophil influx, cytokine release, percent of apoptotic cells, airway plugging, and survival. Administration of a JNK inhibitor 1 h after smoke inhalation decreased airway apoptosis, mucous plugging, influx of inflammatory cells, and the release of cytokines and significantly prolonged animal survival ( P < 0.05). These in vivo data show that the JNK pathway plays a critical role in smoke-induced lung injury and offer an attractive therapeutic approach for this injury.

scholarly journals The AF-6 Homolog Canoe Acts as a Rap1 Effector During Dorsal Closure of the Drosophila Embryo

Genetics ◽  
2003 ◽  
Vol 165 (1) ◽  
pp. 159-169
Author(s):  
Benjamin Boettner ◽  
Phoebe Harjes ◽  
Satoshi Ishimaru ◽  
Michael Heke ◽  
Hong Qing Fan ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Genetic Interaction ◽  
Critical Role ◽  
Adherens Junction ◽  
Small Gtpases ◽  
Drosophila Embryo ◽  
Dorsal Closure ◽  
Cell Sheets ◽  
Jnk Pathway

Abstract Rap1 belongs to the highly conserved Ras subfamily of small GTPases. In Drosophila, Rap1 plays a critical role in many different morphogenetic processes, but the molecular mechanisms executing its function are unknown. Here, we demonstrate that Canoe (Cno), the Drosophila homolog of mammalian junctional protein AF-6, acts as an effector of Rap1 in vivo. Cno binds to the activated form of Rap1 in a yeast two-hybrid assay, the two molecules colocalize to the adherens junction, and they display very similar phenotypes in embryonic dorsal closure (DC), a process that relies on the elongation and migration of epithelial cell sheets. Genetic interaction experiments show that Rap1 and Cno act in the same molecular pathway during DC and that the function of both molecules in DC depends on their ability to interact. We further show that Rap1 acts upstream of Cno, but that Rap1, unlike Cno, is not involved in the stimulation of JNK pathway activity, indicating that Cno has both a Rap1-dependent and a Rap1-independent function in the DC process.

scholarly journals Lymphomagenic CARD11/BCL10/MALT1 signaling drives malignant B-cell proliferation via cooperative NF-κB and JNK activation

2015 ◽  
Vol 112 (52) ◽  
pp. E7230-E7238 ◽  
Author(s):  
Nathalie Knies ◽  
Begüm Alankus ◽  
Andre Weilemann ◽  
Alexandar Tzankov ◽  
Kristina Brunner ◽  
...  
Keyword(s):  
B Cell ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Cell Receptor ◽  
Jnk Pathway ◽  
Large B Cell Lymphoma ◽  
Jnk Inhibitors ◽  
Jnk Activation ◽  
Large B Cell

The aggressive activated B cell-like subtype of diffuse large B-cell lymphoma is characterized by aberrant B-cell receptor (BCR) signaling and constitutive nuclear factor kappa-B (NF-κB) activation, which is required for tumor cell survival. BCR-induced NF-κB activation requires caspase recruitment domain-containing protein 11 (CARD11), and CARD11 gain-of-function mutations are recurrently detected in human diffuse large B-cell lymphoma (DLBCL). To investigate the consequences of dysregulated CARD11 signaling in vivo, we generated mice that conditionally express the human DLBCL-derived CARD11(L225LI) mutant. Surprisingly, CARD11(L225LI) was sufficient to trigger aggressive B-cell lymphoproliferation, leading to early postnatal lethality. CARD11(L225LI) constitutively associated with B-cell CLL/lymphoma 10 (BCL10) and mucosa-associated lymphoid tissue lymphoma translocation gene 1 (MALT1) to simultaneously activate the NF-κB and c-Jun N-terminal kinase (JNK) signaling cascades. Genetic deficiencies of either BCL10 or MALT1 completely rescued the phenotype, and pharmacological inhibition of JNK was, similar to NF-κB blockage, toxic to autonomously proliferating CARD11(L225LI)-expressing B cells. Moreover, constitutive JNK activity was observed in primary human activated B cell-like (ABC)-DLBCL specimens, and human ABC-DLBCL cells were also sensitive to JNK inhibitors. Thus, our results demonstrate that enforced activation of CARD11/BCL10/MALT1 signaling is sufficient to drive transformed B-cell expansion in vivo and identify the JNK pathway as a therapeutic target for ABC-DLBCL.

scholarly journals Loss offlflTriggers JNK-Dependent Cell Death inDrosophila

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Jiuhong Huang ◽  
Lei Xue
Keyword(s):  
Cell Death ◽  
Function Analysis ◽  
Ectopic Expression ◽  
Negative Regulator ◽  
Loss Of Function ◽  
Jnk Pathway ◽  
Dependent Cell ◽  
Jnk Activation ◽  
First Time

falafel(flfl) encodes aDrosophilahomolog of human SMEK whosein vivofunctions remain elusive. In this study, we performed gain-of-function and loss-of-function analysis inDrosophilaand identified flfl as a negative regulator of JNK pathway-mediated cell death. While ectopic expression offlflsuppresses TNF-triggered JNK-dependent cell death, loss offlflpromotes JNK activation and cell death in the developing eye and wing. These data report for the first time an essential physiological function offlflin maintaining tissue homeostasis and organ development. As the JNK signaling pathway has been evolutionary conserved from fly to human, a similar role of PP4R3 in JNK-mediated physiological process is speculated.

scholarly journals Molecular Docking and Admet Analyses of Photochemicals from Nigella sativa (blackseed), Trigonella foenum-graecum (Fenugreek) and Anona muricata (Soursop) on SARS-CoV-2 Target

2020 ◽  
Author(s):  
OLUWASEUN TAOFEEK
Keyword(s):  
Molecular Docking ◽  
Electrostatic Interactions ◽  
Nigella Sativa ◽  
Critical Role ◽  
In Vivo Studies ◽  
Viral Gene ◽  
Discovery Studio ◽  
Trigonella Foenum Graecum

The novel severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) responsible for the 2019 coronavirus disease (COVID-19) has caused a global health challenge. The SARS-COV-2 main protease, 3CLpro/Mpro plays a critical role in the viral gene expression and replication and has been a major target for inhibiting viral maturation and enhancing host innate immune responses against COVID-19. In this study, we screened a library of 38 phytochemicals from Nigella sativa (blackseed), Trigonella foenum-graecum (Fenugreek) and Anona muricata (Soursop) potent medicinal plants with reported antiviral properties - in a molecular docking protocol on 3CLpro using Autodock4.0 tool implanted in PyRx followed by docking validation and insilico absorption, distribution, metabolism, excretion, and toxicology (ADMET) evaluations. The docking results were visualized using Accelrys Discovery Studio and Pymol software. Among the 38 ligands screened, 19 showed significant interaction through non-covalent hydrogen bonding, hydrophobic, and electrostatic interactions with binding affinities from -5.3kcal/mol to -8.1kcal/mol indicating significant binding interactions at the active site binding pocket. Another important interaction observed in the study which mostly involve the transfer of charges was pi-interactions such as Pi-Pi interaction, Pi-Alkyl interaction, Pi-Sulfur interaction, Pi- Sigma, and Pi-Pi stacking. The docking results revealed that phytochemicals from T. foenum-graecum showed more 3CLpro inhibitory potential compared to those from N. sativa and A. muricata. Insilico ADMET evaluations for drug-like and lead-like characteristics however demonstrated that only 8 ligands - apigenin, kaempferol, luteolin, dithymoquinone, naringenine, nornuciferine, quercetin and nigellidine were actually drug-like; showed best activities against 3CLpro, and lack hepatotoxicity effects while none was lead-like. Insilico results of this study further suggested that drug repurposing candidates, remdesivir, indinavir,hydroxychloroquine, chloroquine and ritonavir,exhibited various interactions with 3CLpro. Hence, further in vitro and in vivo studies are proposed.

Agonist-Induced Binding of the Regulatory Scaffold Protein Spinophilin to Protein Phosphatase-1 In Platelets

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 2029-2029
Author(s):  
Andrew Sinnamon ◽  
Peisong Ma ◽  
Lawrence F. Brass
Keyword(s):  
Platelet Activation ◽  
Conflicts Of Interest ◽  
Thrombus Formation ◽  
Tyrosine Phosphatase ◽  
Critical Role ◽  
Scaffold Protein ◽  
Western Blots ◽  
Co Precipitation

Abstract Abstract 2029 Platelet regulation plays a critical role in hemostasis. Underactivation can result in failure to stop bleeding, whereas inappropriate platelet activation can cause thrombus formation. The 130-kDa scaffold protein spinophilin (SPL) has recently been shown to play a role in preventing platelet overactivation by forming a complex with the proteins RGS10, RGS18, and the tyrosine phosphatase SHP-1. This complex dissociates when platelet are activated by thrombin or thromboxane A2 and evidence from spinophilin knockout mice suggests that this regulates platelet activation in vitro and in vivo. Spinophilin was originally isolated as a binding partner for the serine/threonine phosphatase, PP-1, in neurons. Here we asked whether PP-1 forms a complex with spinophilin in human platelets and, if so, whether the complex is affected by platelet activation. The approaches that we used to answer this question included Western blotting with antibodies to PP-1 and spinophilin, and co-precipitation studies looking for an association between spinophilin and PP-1. The results of the Western blots confirm the presence of PP-1 in platelets. The initial co-precipitation studies show that little, if any, PP-1 is associated with spinophilin in resting platelets, but there is a time-dependent increase in the SPL/PP-1 complex when platelets are activated with the PAR1 (thrombin receptor) activating peptide, SFLLRN. Thus it appears that within approximately the same time frame that the SPL/RGS/SHP-1 complex is decaying in activated platelets, the SPL/PP-1 complex is forming. Targets for PP1 have not been fully identified in platelets, but it is known that spinophilin localizes to the plasma membrane upon platelet activation. Since spinophilin is thought to direct PP1 targeting in neurons, it is reasonable to propose that it may be directing PP1 to targets in platelets in a similar manner. The studies described in this abstract were supported in part by a 2010 ASH Trainee Research Award to Andrew Sinnamon, who is a first year medical student at the University of Pennsylvania. Disclosures: No relevant conflicts of interest to declare.

scholarly journals The L4 22-Kilodalton Protein Plays a Role in Packaging of the Adenovirus Genome

2006 ◽  
Vol 80 (14) ◽  
pp. 6973-6981 ◽  
Author(s):  
Philomena Ostapchuk ◽  
Mary E. Anderson ◽  
Sharanya Chandrasekhar ◽  
Patrick Hearing
Keyword(s):  
Consensus Sequence ◽  
Critical Role ◽  
Viral Gene Expression ◽  
Specific Protein ◽  
Viral Gene ◽  
Sequence Motif ◽  
Binding Studies ◽  
Viral Dna

ABSTRACT Packaging of the adenovirus (Ad) genome into a capsid is absolutely dependent upon the presence of a cis-acting region located at the left end of the genome referred to as the packaging domain. The functionally significant sequences within this domain consist of at least seven similar repeats, referred to as the A repeats, which have the consensus sequence 5′ TTTG-N8-CG 3′. In vitro and in vivo binding studies have demonstrated that the adenovirus protein IVa2 binds to the CG motif of the packaging sequences. In conjunction with IVa2, another virus-specific protein binds to the TTTG motifs in vitro. The efficient formation of these protein-DNA complexes in vitro was precisely correlated with efficient packaging activity in vivo. We demonstrate that the binding activity to the TTTG packaging sequence motif is the product of the L4 22-kDa open reading frame. Previously, no function had been ascribed to this protein. Truncation of the L4 22-kDa protein in the context of the viral genome did not reduce viral gene expression or viral DNA replication but eliminated the production of infectious virus. We suggest that the L4 22-kDa protein, in conjunction with IVa2, plays a critical role in the recognition of the packaging domain of the Ad genome that leads to viral DNA encapsidation. The L4 22-kDa protein is also involved in recognition of transcription elements of the Ad major late promoter.

scholarly journals Berberine Induces NSCLC Apoptosis Via Activation of ROS/ASK1/JNK Pathway in Vitro and Vivo

2021 ◽  
Author(s):  
qianqian chen ◽  
Yaqin Hou ◽  
Bingjie Hao ◽  
Zhou Ding ◽  
Qing Xia ◽  
...  
Keyword(s):  
Caspase 3 ◽  
Cell Counting ◽  
Ros Generation ◽  
Dependent Manner ◽  
Jnk Pathway ◽  
Mitochondrial Membrane Depolarization ◽  
Induced Apoptosis ◽  
Jnk Activation

Abstract BackgroundNon-small cell lung cancer (NSCLC) accounts for approximately 85% of all lung cancers. Berberine (BBR), as an isoquinoline alkaloid, is commonly utilized in traditional Chinese medicine. Previous studies have proven that BBR possesses potential anti-tumor effect. However, the mechanism of on mitochondrial function in anti-NSCLC are still unknown.MethodsCell Counting Kit-8 (CCK-8), flow cytometry and western blotting were utilized to characterize the roles and relationships among BBR, ROS, ASK1, JNK, coxIV,caspase-3, cytochrome c ,bcl-2 and bax in NSCLC. Immunohistochemical (IHC) analysis was built to examine their expression in vivo.ResultsIn this study, we found that BBR potently suppressed NSCLC cells (A549 and PC9) growth by inducing apoptosis in a dose- and time-dependent manner. BBR induced apoptosis in NSCLC as evidenced by caspase-3 cleavage, cytochrome c release, and mitochondrial membrane depolarization. Furthermore, BBR induced ROS generation and ASK1 and JNK activation. To explore whether such apoptosis was linked to ROS production and ASK1 and JNK activation, we treated cells with a JNK inhibitor (SP600125), which significantly suppressed BBR-induced apoptosis. We further found that treating these cells with the anti-oxidant N-acetyl cysteine (NAC) was sufficient to both suppress ASK1 and JNK activation and to disrupt apoptotic induction.ConclusionsTogether, these data suggest that BBR induces NSCLC cells apoptosis via ROS-mediated ASK1/JNK and mitochondrial pathway activation.

scholarly journals Protein Phosphatase 4 Promotes Hepatocyte Lipoapoptosis by Regulating RAC1/MLK3/JNK Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Xiuqing Huang ◽  
Guang Yang ◽  
Li Zhao ◽  
Huiping Yuan ◽  
Hao Chen ◽  
...  
Keyword(s):  
Protein Phosphatase ◽  
Hepatic Insulin Resistance ◽  
Jnk Pathway ◽  
Pathway Activation ◽  
Jnk Signaling Pathway ◽  
Induced Apoptosis ◽  
Jnk Activation ◽  
First Time

Lipotoxicity-induced apoptosis, also referred to as lipoapoptosis, is one of the important initial factors promoting the progression from hepatosteatosis to nonalcoholic steatohepatitis (NASH). Saturated free fatty acids (SFAs), which are increased significantly in NASH, are directly hepatotoxic which induce hepatocyte lipoapoptosis. Previously, we reported that protein phosphatase 4 (PP4) was a novel regulator of hepatic insulin resistance and lipid metabolism, but its role in hepatic lipoapoptosis remains unexplored. In this study, we found out that PP4 was upregulated in the livers of western diet-fed-induced NASH mice and SFA-treated murine primary hepatocytes and HepG2 cells. In addition, we found for the first time that suppression of PP4 decreased SFA-induced JNK activation and expression of key modulators of hepatocyte lipoapoptosis including p53-upregulated modulator of apoptosis (PUMA) and Bcl-2-interacting mediator (Bim) and reduced hepatocyte lipoapoptosis level as well both in vitro and in vivo. Further study revealed that PP4 induced JNK activation and lipoapoptosis-related protein expression by regulating the RAC1/MLK3 pathway instead of the PERK/CHOP pathway. The effects of palmitate-treated and PP4-induced lipoapoptosis pathway activation were largely abolished by RAC1 inhibition. Moreover, we identified that PP4 interacted with RAC1 and regulated GTPase activity of RAC1. In conclusion, these results demonstrated that PP4 was a novel regulator of hepatocyte lipoapoptosis and mediated hepatocyte lipoapoptosis by regulating the RAC1/MLK3/JNK signaling pathway. Our finding provided new insights into the mechanisms of this process.

scholarly journals MarvelD3 couples tight junctions to the MEKK1–JNK pathway to regulate cell behavior and survival

2014 ◽  
Vol 204 (5) ◽  
pp. 821-838 ◽  
Author(s):  
Emily Steed ◽  
Ahmed Elbediwy ◽  
Barbara Vacca ◽  
Sébastien Dupasquier ◽  
Sandra A. Hemkemeyer ◽  
...  
Keyword(s):  
Tight Junctions ◽  
Tumor Cell Line ◽  
Metastatic Tumor ◽  
Tumor Formation ◽  
Cell Behavior ◽  
Permeability Barrier ◽  
Jnk Pathway ◽  
Junctional Permeability ◽  
Jnk Activation

MarvelD3 is a transmembrane component of tight junctions, but there is little evidence for a direct involvement in the junctional permeability barrier. Tight junctions also regulate signaling mechanisms that guide cell proliferation; however, the transmembrane components that link the junction to such signaling pathways are not well understood. In this paper, we show that MarvelD3 is a dynamic junctional regulator of the MEKK1–c-Jun NH2-terminal kinase (JNK) pathway. Loss of MarvelD3 expression in differentiating Caco-2 cells resulted in increased cell migration and proliferation, whereas reexpression in a metastatic tumor cell line inhibited migration, proliferation, and in vivo tumor formation. Expression levels of MarvelD3 inversely correlated with JNK activity, as MarvelD3 recruited MEKK1 to junctions, leading to down-regulation of JNK phosphorylation and inhibition of JNK-regulated transcriptional mechanisms. Interplay between MarvelD3 internalization and JNK activation tuned activation of MEKK1 during osmotic stress, leading to junction dissociation and cell death in MarvelD3-depleted cells. MarvelD3 thus couples tight junctions to the MEKK1–JNK pathway to regulate cell behavior and survival.

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