scholarly journals SPRY4 acts as an indicator of osteoarthritis severity and regulates chondrocyte hypertrophy and ECM protease expression

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Sunghyun Park ◽  
Yoshie Arai ◽  
Alvin Bello ◽  
Hansoo Park ◽  
Dohyun Kim ◽  
...  
Keyword(s):  
Mapk Pathway ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Cartilage Tissue ◽  
Sprague Dawley ◽  
Healthy Human ◽  
Human Cartilage ◽  
Chondrocyte Hypertrophy ◽  
Protease Expression

AbstractOsteoarthritis (OA) causes serious changes in the metabolic and signaling pathways of chondrocytes, including the mitogen-activated protein kinase (MAPK) pathway. However, the role of sprouty RTK signaling antagonist 4 (SPRY4), an inhibitor of MAPK, in the human cartilage tissues and chondrocytes remains to be understood. Here, using SPRY4 gene delivery into healthy and degenerated chondrocytes, we elucidated the role of SPRY4 in preventing chondrocyte hypertrophy. In addition to using the human cartilage tissues with the destabilization of the medial meniscus (DMM) model in Sprague-Dawley (SD) rats, the role of SPRY4 in cartilage tissues and chondrocytes was explored through their molecular and histological analyses. In order to determine the effects of SPRY4 on healthy human chondrocyte hypertrophy, small interfering RNA (siRNA) was used to knock down SPRY4. Lentiviral transduction of SPRY4 into degenerated human chondrocytes allowed us to investigate its ability to prevent hypertrophy. SPRY4 expression levels were higher in healthy human cartilage tissue and chondrocytes than in degenerated human cartilage tissues and hypertrophy-induced chondrocytes. The knockdown of SPRY4 in healthy chondrocytes caused an increase in hypertrophy, senescence, reactive oxygen species (ROS) production, and extracellular matrix (ECM) protease expression. However, all these factors decreased upon overexpression of SPRY4 in degenerated chondrocytes via regulation of the MAPK signaling pathway. We conclude that SPRY4 is a crucial indicator of osteoarthritis (OA) severity and could play an important role in preventing OA in the cartilage by inhibiting chondrocyte hypertrophy.

scholarly journals Role of Phosphatidylinositol Phosphate Signaling in the Regulation of the Filamentous-Growth Mitogen-Activated Protein Kinase Pathway

2015 ◽  
Vol 14 (4) ◽  
pp. 427-440 ◽  
Author(s):  
Hema Adhikari ◽  
Paul J. Cullen
Keyword(s):  
Protein Kinase ◽  
Mapk Pathway ◽  
Filamentous Growth ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Hog Pathway ◽  
Mapk Activity ◽  
Conditional Allele ◽  
Mitogen Activated Protein

ABSTRACTReversible phosphorylation of the phospholipid phosphatidylinositol (PI) is a key event in the determination of organelle identity and an underlying regulatory feature in many biological processes. Here, we investigated the role of PI signaling in the regulation of the mitogen-activated protein kinase (MAPK) pathway that controls filamentous growth in yeast. Lipid kinases that generate phosphatidylinositol 4-phosphate [PI(4)P] at the Golgi (Pik1p) or PI(4,5)P2 at the plasma membrane (PM) (Mss4p and Stt4p) were required for filamentous-growth MAPK pathway signaling. Introduction of a conditional allele ofPIK1(pik1-83) into the filamentous (Σ1278b) background reduced MAPK activity and caused defects in invasive growth and biofilm/mat formation. MAPK regulatory proteins that function at the PM, including Msb2p, Sho1p, and Cdc42p, were mislocalized in thepik1-83mutant, which may account for the signaling defects of the PI(4)P kinase mutants. Other PI kinases (Fab1p and Vps34p), and combinations of PIP (synaptojanin-type) phosphatases, also influenced the filamentous-growth MAPK pathway. Loss of these proteins caused defects in cell polarity, which may underlie the MAPK signaling defect seen in these mutants. In line with this possibility, disruption of the actin cytoskeleton by latrunculin A (LatA) dampened the filamentous-growth pathway. Various PIP signaling mutants were also defective for axial budding in haploid cells, cell wall construction, or proper regulation of the high-osmolarity glycerol response (HOG) pathway. Altogether, the study extends the roles of PI signaling to a differentiation MAPK pathway and other cellular processes.

scholarly journals APPL1 mediates adiponectin-stimulated p38 MAPK activation by scaffolding the TAK1-MKK3-p38 MAPK pathway

2011 ◽  
Vol 300 (1) ◽  
pp. E103-E110 ◽  
Author(s):  
Xiaoban Xin ◽  
Lijun Zhou ◽  
Caleb M. Reyes ◽  
Feng Liu ◽  
Lily Q. Dong
Keyword(s):  
Protein Kinase ◽  
P38 Mapk ◽  
Mapk Pathway ◽  
Adaptor Protein ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Scaffolding Protein ◽  
Mapk Activation ◽  
P38 Mapk Pathway ◽  
Mitogen Activated Protein

The adaptor protein APPL1 mediates the stimulatory effect of adiponectin on p38 mitogen-activated protein kinase (MAPK) signaling, yet the underlying mechanism remains unclear. Here we show that, in C2C12 cells, overexpression or suppression of APPL1 enhanced or suppressed, respectively, adiponectin-stimulated p38 MAPK upstream kinase cascade, consisting of transforming growth factor-β-activated kinase 1 (TAK1) and mitogen-activated protein kinase kinase 3 (MKK3). In vitro affinity binding and coimmunoprecipitation experiments revealed that TAK1 and MKK3 bind to different regions of APPL1, suggesting that APPL1 functions as a scaffolding protein to facilitate adiponectin-stimulated p38 MAPK activation. Interestingly, suppressing APPL1 had no effect on TNFα-stimulated p38 MAPK phosphorylation in C2C12 myotubes, indicating that the stimulatory effect of APPL1 on p38 MAPK activation is selective. Taken together, our study demonstrated that the TAK1-MKK3 cascade mediates adiponectin signaling and uncovers a scaffolding role of APPL1 in regulating the TAK1-MKK3-p38 MAPK pathway, specifically in response to adiponectin stimulation.

Sprouty proteins: antagonists of endothelial cell signaling and more

2003 ◽  
Vol 90 (10) ◽  
pp. 586-590 ◽  
Author(s):  
Miguel Cabrita ◽  
Gerhard Christofori
Keyword(s):  
Growth Factor ◽  
Mapk Pathway ◽  
Medical Science ◽  
Receptor Activation ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Dual Function ◽  
Vegf Receptor ◽  
Mapk Activation ◽  
Binding Partners

SummaryAmong many signaling pathways, receptor tyrosine kinases (RTKs) can activate the mitogen-activated protein kinase (MAPK) signaling pathway that subsequently leads to a variety of cellular changes, including proliferation, differentiation and motility. The regulation of growth factor signaling is complex, and various cell types respond differently to the same stimulus for reasons not entirely understood. The recent discovery in Drosophila of Sprouty (dSpry), an inhibitor of RTK-induced MAPK activation, provides clues to how these signals are regulated. In mammals, four orthologues of dSpry, Spry1-4, have been described, and in this review we discuss their functional characteristics. Mammalian Sprys, like dSpry, are ligand-induced feedback inhibitors of a number of growth factor receptors. In endothelial cells, upon fibroblast growth factor (FGF) receptor and vascular endothelial growth factor (VEGF) receptor activation, Sprys translocate to the plasma membrane and inhibit cell growth and proliferation. However, in epidermal growth factor (EGF)-stimulated cells, Sprys can enhance MAPK activation. In addition, Sprys have many binding partners, including different effectors of the MAPK activation pathway. The intersection point where Sprys interfere in the MAPK pathway as well as their interactions with other proteins may partly explain the dual, yet opposing roles, on growth factor-induced MAPK activation. Moreover, Sprys require tyrosine phosphorylation to interact with their binding partners, a prerequisite for their dual function. Hence, Sprys add another layer of complexity to the regulation of RTK-mediated signal transduction that begins to explain the variation in cellular responses to growth factors.This publication was partially financed by Serono Foundation for the Advancement of Medical Science.Part of this paper was originally presented at the 2nd International Workshop on New Therapeutic Targets in Vascular Biology from February 6-9, 2003 in Geneva, Switzerland.

scholarly journals Estrogen Enhances Matrix Synthesis in Nucleus Pulposus Cell through the Estrogen Receptor β-p38 MAPK Pathway

2016 ◽  
Vol 39 (6) ◽  
pp. 2216-2226 ◽  
Author(s):  
Pei Li ◽  
Yuan Xu ◽  
Yibo Gan ◽  
Liyuan Wang ◽  
Bin Ouyang ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Signaling Pathway ◽  
P38 Mapk ◽  
Mapk Pathway ◽  
Mapk Signaling ◽  
Mapk Signaling Pathway ◽  
Matrix Synthesis ◽  
P38 Mapk Pathway ◽  
Collagen Ii

Background/Aims: Matrix homeostasis within the disc nucleus pulposus (NP) tissue is important for disc function. Increasing evidence indicates that sex hormone can influence the severity of disc degeneration. This study was aimed to study the role of 17β-estradiol (E2) in NP matrix synthesis and its underlying mechanism. Methods: Rat NP cells were cultured with (10-5, 10-7 and 10-9 M) or without (control) E2 for48 hours. The estrogen receptor (ER)-β antagonist PHTPP and ERβ agonist ERB 041 were used to investigate the role mediated by ERβ. The p38 MAPK inhibitor SB203580 was used to investigate the role of p38 MAPK signaling pathway. Gene and protein expression of SOX9, aggrecan and collagen II, glycosaminoglycan (GAG) content, and immunostaining assay for aggrecan and collagen II were analyzed to evaluate matrix production in rat NP cells. Results: E2 enhanced NP matrix synthesis in a concentration-dependent manner regarding gene and proetin expression of SOX9, aggrecan and collagen II, protein deposition of aggrecan and collagen II, and GAG content. Moreover, activation of p38 MAPK signaling pathway was increased with elevating E2 concentration. Further analysis indicated that ERB 041 and PHTPP could respectively enhance and suppress effects of E2 on matrix synthesis in NP cells, as well as activation of p38 MAPK pathway. Additionally, inhibition of p38 MAPK signaling pathway significantly abolished the effects of E2 on matrix synthesis. Conclusion: E2 can enhance matrix synthesis of NP cells and the ERβ/p38 MAPK pathway is involved in this regulatory process.

scholarly journals An adaptive signaling network in melanoma inflammatory niches confers tolerance to MAPK signaling inhibition

2017 ◽  
Vol 214 (6) ◽  
pp. 1691-1710 ◽  
Author(s):  
Helen L. Young ◽  
Emily J. Rowling ◽  
Mattia Bugatti ◽  
Emanuele Giurisato ◽  
Nadia Luheshi ◽  
...  
Keyword(s):  
Mapk Pathway ◽  
Acquired Resistance ◽  
Drug Tolerance ◽  
Mapk Signaling ◽  
Signaling Network ◽  
Mitogen Activated Protein Kinase ◽  
Cytokine Signaling ◽  
Adaptive Responses ◽  
Mapk Inhibitors

Mitogen-activated protein kinase (MAPK) pathway antagonists induce profound clinical responses in advanced cutaneous melanoma, but complete remissions are frustrated by the development of acquired resistance. Before resistance emerges, adaptive responses establish a mutation-independent drug tolerance. Antagonizing these adaptive responses could improve drug effects, thereby thwarting the emergence of acquired resistance. In this study, we reveal that inflammatory niches consisting of tumor-associated macrophages and fibroblasts contribute to treatment tolerance through a cytokine-signaling network that involves macrophage-derived IL-1β and fibroblast-derived CXCR2 ligands. Fibroblasts require IL-1β to produce CXCR2 ligands, and loss of host IL-1R signaling in vivo reduces melanoma growth. In tumors from patients on treatment, signaling from inflammatory niches is amplified in the presence of MAPK inhibitors. Signaling from inflammatory niches counteracts combined BRAF/MEK (MAPK/extracellular signal–regulated kinase kinase) inhibitor treatment, and consequently, inhibiting IL-1R or CXCR2 signaling in vivo enhanced the efficacy of MAPK inhibitors. We conclude that melanoma inflammatory niches adapt to and confer drug tolerance toward BRAF and MEK inhibitors early during treatment.

scholarly journals Progranulin modulates cartilage-specific gene expression via sirtuin 1–mediated deacetylation of the transcription factors SOX9 and P65

2020 ◽  
Vol 295 (39) ◽  
pp. 13640-13650 ◽  
Author(s):  
Dongxu Feng ◽  
Xiaomin Kang ◽  
Ruiqi Wang ◽  
He Chen ◽  
Kun Zhang ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Molecular Mechanisms ◽  
Sirtuin 1 ◽  
Cartilage Tissue ◽  
Nuclear Accumulation ◽  
Specific Gene ◽  
Causative Role ◽  
Human Cartilage ◽  
Cartilage Homeostasis

Progranulin (PGRN) is an autocrine growth factor that exerts crucial roles within cartilage tissue; however, the molecular mechanisms underlying PGRN-mediated cartilage homeostasis remain elusive. In the present study, we investigated the role of PGRN in regulating chondrocyte homeostasis and its therapeutic potential for managing osteoarthritis (OA). We found that PGRN levels are significantly increased in human cartilage in mild OA and that its expression is decreased in the cartilage in severe OA. In vitro, treatment of primary rat chondrocytes with recombinant PGRN significantly enhanced the levels of collagen type II α 1 chain (COL2A1) and aggrecan, and attenuated TNFα-induced up-regulation of matrix metallopeptidase 13 (MMP13) and ADAM metallopeptidase with thrombospondin type 1 motif 5 (ADAMTS5) in chondrocytes. These effects were abrogated in SIRT1−/− cells, indicating a causative role of SIRT1 in the effects of PGRN on protein expression in chondrocytes. Mechanistically, PGRN increased SIRT1 expression and activity, which reduced the acetylation levels of SRY-box transcription factor (SOX9) and transcription factor P65 (P65) and thereby promoted nuclear translocation of SOX9 and inhibited TNFα-induced P65 nuclear accumulation to maintain chondrocyte homeostasis. In conclusion, our findings reveal a mechanism of action for PGRN that maintains cartilage homeostasis and supports the notion that PGRN up-regulation may be a promising strategy for managing OA.

scholarly journals Avβ3 Single-Stranded DNA Aptamer Attenuates Vascular Smooth Muscle Cell Proliferation and Migration via Ras-PI3K/MAPK Pathway

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Hong-Bing Wu ◽  
Zhi-Wei Wang ◽  
Feng Shi ◽  
Zong-Li Ren ◽  
Luo-Cheng Li ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Cell Cycle Progression ◽  
Mapk Pathway ◽  
Mapk Signaling ◽  
Dna Aptamer ◽  
Mitogen Activated Protein Kinase ◽  
Vsmc Proliferation ◽  
And Migration ◽  
Proliferation And Migration

Objectives. To observe the effect of avβ3 single-stranded (ss) DNA on proliferation and migration of vascular smooth muscle cells (VSMCs) and its potential mechanism. Background. Percutaneous transluminal coronary angioplasty (PTCA) is currently the preferred method for the treatment of coronary heart disease. However, vascular restenosis still occurs after PTCA treatment, severely affecting the clinical efficacy of PTCA. Integrin avβ3, which is widely expressed on various cell surfaces, plays an important role in the proliferation and migration of VSMCs. Methods. In this experiment, we used systematic evolution of ligands by exponential enrichment (SELEX) to screen out avβ3 ssDNA, which has high affinity and specificity to the avβ3 protein. MTT, Transwell, and cell scratch assays were carried out to examine the effect of avβ3 ssDNA on the proliferation and migration of VSMCs. Flow cytometry was performed to detect apoptosis and cell cycle progression. The effect of avβ3 ssDNA on the Ras-phosphatidylinositol-4,5-bisphosphate 3-kinase/mitogen-activated protein kinase (PI3K/MAPK) signaling pathway was evaluated by quantitative reverse transcription polymerase chain reaction and western blot. Results. In the present study, we found that avβ3 ssDNA significantly decreased the expression of osteopontin, focal adhesion kinase, Ras, p-PI3K, and p-MAPK at both mRNA and protein levels (P<0.05). Avβ3 ssDNA also inhibited VSMC proliferation and migration while promoting apoptosis (P<0.05), as demonstrated by the upregulation of the proapoptotic proteins Bax and active caspase 3 (P<0.05). Conclusions. The findings suggest that avβ3 ssDNA inhibited the proliferation and migration of VSMCs by suppressing the activation of Ras-PI3K/MAPK signaling.

scholarly journals miR-19 Promotes Cell Proliferation, Invasion, Migration, and EMT by Inhibiting SPRED2-mediated Autophagy in Osteosarcoma Cells

2020 ◽  
Vol 29 ◽  
pp. 096368972096246
Author(s):  
Chuhai Xie ◽  
Shengyao Liu ◽  
Boyi Wu ◽  
Yu Zhao ◽  
Binwei Chen ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Mapk Pathway ◽  
Biological Effects ◽  
Rapid Development ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Luciferase Reporter ◽  
Osteosarcoma Cells ◽  
Mesenchymal Transition ◽  
Erk Mapk

Osteosarcoma is an aggressive malignancy with rapid development and poor prognosis. microRNA-19 (miR-19) plays an important role in several biological processes. Sprouty-related EVH1 domain protein 2 (SPRED2) is a suppressor of extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK) signaling to inhibit tumor development and progression by promoting autophagy. In this study, we investigated the roles of miR-19, SPRED2, and autophagy in osteosarcoma. We detected the expression of miR-19, SPRED2, epithelial–mesenchymal transition (EMT) markers, and autophagy-related proteins via quantitative real-time polymerase chain reaction or western blot. To evaluate the function of miR-19 and SPRED2, we used MTT and colony formation assays to detect cell proliferation, Transwell, and wound-healing assays to detect cell invasion and migration. Targetscan and luciferase reporter assays confirmed the relationship between SPRED2 and miR-19. The expression of miR-19 was significantly upregulated in osteosarcoma, while SPRED2 was downregulated. miR-19 inhibitor reduced cell proliferation, invasion, migration, and EMT, while its cell biological effects were partially reversed by addition of autophagy inhibitor 3-methyladenine (3-MA) or SPRED2 siRNA in osteosarcoma. SPRED2, a suppressor of ERK/MAPK pathway that is known to trigger autophagy, was identified as a direct target of miR-19. SPRED2 overexpression increased cell proliferation, invasion, migration, and EMT by promoting autophagy, and the effects could be inhibited by 3-MA. Collectively, these findings reveal an underlying mechanism for development of osteosarcoma. miR-19 was upregulated in osteosarcoma cells, and negatively regulated SPRED2, thus promoting the malignant transformation of osteosarcoma cells via inhibiting SPRED2-induced autophagy. Therefore, miR-19/SPRED2 may be a potential target for the treatment of osteosarcoma.

scholarly journals Long noncoding RNA 00976 promotes pancreatic cancer progression through OTUD7B by sponging miR-137 involving EGFR/MAPK pathway

2019 ◽  
Vol 38 (1) ◽  
Author(s):  
Shan Lei ◽  
Zhiwei He ◽  
Tengxiang Chen ◽  
Xingjun Guo ◽  
Zhirui Zeng ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Cell Proliferation ◽  
Signaling Pathway ◽  
Mapk Pathway ◽  
Mapk Signaling ◽  
Mapk Signaling Pathway ◽  
Migration And Invasion ◽  
Potential Biomarker

Abstract Background Accumulation evidence indicates the vital role of long non-coding RNAs (lncRNAs) in tumorigenesis and the progression of malignant tumors, including pancreatic cancer (PC). However, the role and the molecular mechanism of long non-coding RNA 00976 is unclear in pancreatic cancer. Methods In situ hybridization (ISH) and qRT-PCR was performed to investigate the association between linc00976 expression and the clinicopathological characteristics and prognosis of patients with PC. Subsequently, linc00976 over-expression vector and shRNAs were transfected into PC cells to up-regulate or down-regulate linc00976 expression. Loss- and gain-of function assays were performed to investigate the role of linc00976 in proliferation and metastasis in vitro and vivo. ITRAQ, bioinformatic analysis and rescue assay were used to illustrate the ceRNA mechanism network of linc00976/miR-137/OTUD7B and its downstream EGFR/MAPK signaling pathway. Results linc00976 expression was overexpressed in PC tissues and cell lines and was positively associated with poorer survival in patients with PC. Function studies revealed that linc00976 knockdown significantly suppressed cell proliferation, migration and invasion in vivo and in vitro, whereas its overexpression reversed these effects. Based on Itraq results and online database prediction, Ovarian tumor proteases OTUD7B was found as a downstream gene of linc00976, which deubiquitinated EGFR mediates MAPK signaling activation. Furthermore, Bioinformatics analysis and luciferase assays and rescue experiments revealed that linc00976/miR137/OTUD7B established the ceRNA network modulating PC cell proliferation and tumor growth. Conclusion The present study demonstrates that linc00976 enhances the proliferation and invasion ability of PC cells by upregulating OTUD7B expression, which was a target of miR-137. Ultimately, OTUD7B mediates EGFR and MAPK signaling pathway, suggesting that linc00976/miR-137/OTUD7B/EGFR axis may act as a potential biomarker and therapeutic target for PC.

scholarly journals 15-deoxy-Δ12,14-prostaglandin J2Down-Regulates Activin-Induced Activin Receptor, Smad, and Cytokines Expression via Suppression of NF-κB and MAPK Signaling in HepG2 Cells

PPAR Research ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Seung-Won Park ◽  
Chunghee Cho ◽  
Byung-Nam Cho ◽  
Youngchul Kim ◽  
Tae Won Goo ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Hepg2 Cells ◽  
Mapk Pathway ◽  
Mapk Signaling ◽  
Activin A ◽  
Mitogen Activated Protein Kinase ◽  
Erk Phosphorylation ◽  
Mitogen Activated Protein ◽  
Regulatory Effects ◽  
Activin Receptors

15-Deoxy-Δ12,14-prostaglandin J2(15d-PGJ2) and activin are implicated in the control of apoptosis, cell proliferation, and inflammation in cells. We examined both the mechanism by which 15d-PGJ2regulates the transcription of activin-induced activin receptors (ActR) and Smads in HepG2 cells and the involvement of the nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) pathways in this regulation. Activin A (25 ng/mL) inhibited HepG2 cell proliferation, whereas 15d-PGJ2(2 μM and 5 μM) had no effect. Activin A and 15d-PGJ2showed different regulatory effects on ActR and Smad expression, NF-κB p65 activity and MEK/ERK phosphorylation, whereas they both decreased IL-6 production and increased IL-8 production. When co-stimulated with 15d-PGJ2and activin, 15d-PGJ2inhibited the activin-induced increases in ActR and Smad expression, and decreased activin-induced IL-6 production. However, it increased activin-induced IL-8 production. In addition, 15d-PGJ2inhibited activin-induced NF-κB p65 activity and activin-induced MEK/ERK phosphorylation. These results suggest that 15d-PGJ2suppresses activin-induced ActR and Smad expression, down-regulates IL-6 production, and up-regulates IL-8 production via suppression of NF-κB and MAPK signaling pathway in HepG2 cells. Regulation of ActR and Smad transcript expression and cytokine production involves NF-κB and the MAPK pathway via interaction with 15d-PGJ2/activin/Smad signaling.

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