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Sinnett-Smith J, Torres-Marquez ME, Chang JK, Shimizu Y, Hao F, Martin MG, Rozengurt E. Statins inhibit protein kinase D (PKD) activation in intestinal cells and prevent PKD1-induced growth of murine enteroids. Am J Physiol Cell Physiol 2023; 324:C807-C820. [PMID: 36779664 PMCID: PMC10042602 DOI: 10.1152/ajpcell.00286.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 01/10/2023] [Accepted: 01/10/2023] [Indexed: 02/14/2023]
Abstract
We examined the impact of statins on protein kinase D (PKD) activation by G protein-coupled receptor (GPCR) agonists. Treatment of intestinal IEC-18 cells with cerivastatin inhibited PKD autophosphorylation at Ser916 induced by angiotensin II (ANG II) or vasopressin in a dose-dependent manner with half-maximal inhibition at 0.2 µM. Cerivastatin treatment inhibited PKD activation stimulated by these agonists for different times (5-60 min) and blunted HDAC5 phosphorylation, a substrate of PKD. Other lipophilic statins, including simvastatin, atorvastatin, and fluvastatin also prevented PKD activation in a dose-dependent manner. Using IEC-18 cell lines expressing PKD1 tagged with EGFP (enhanced green fluorescent protein), cerivastatin or simvastatin blocked GPCR-mediated PKD1-EGFP translocation to the plasma membrane and its subsequent nuclear accumulation. Similar results were obtained in IEC-18 cells expressing PKD3-EGFP. Mechanistically, statins inhibited agonist-dependent PKD activation rather than acting directly on PKD catalytic activity since exposure to cerivastatin or simvastatin did not impair PKD autophosphorylation or PKD1-EGFP membrane translocation in response to phorbol dibutyrate, which bypasses GPCRs and directly stimulates PKC and PKD. Furthermore, cerivastatin did not inhibit recombinant PKD activity determined via an in vitro kinase assay. Using enteroids generated from intestinal crypt-derived epithelial cells from PKD1 transgenic mice as a model of intestinal regeneration, we show that statins oppose PKD1-mediated increase in enteroid area, complexity (number of crypt-like buds), and DNA synthesis. Our results revealed a previously unappreciated inhibitory effect of statins on receptor-mediated PKD activation and in opposing the growth-promoting effects of PKD1 on intestinal epithelial cells.
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Affiliation(s)
- James Sinnett-Smith
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
- VA Greater Los Angeles Health Care System, Los Angeles, California, United States
| | - M Eugenia Torres-Marquez
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
| | - Jen-Kuan Chang
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
| | - Yuki Shimizu
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
| | - Fang Hao
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
| | - Martin G Martin
- Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
| | - Enrique Rozengurt
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, United States
- VA Greater Los Angeles Health Care System, Los Angeles, California, United States
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An overview of kinin mediated events in cancer progression and therapeutic applications. Biochim Biophys Acta Rev Cancer 2022; 1877:188807. [PMID: 36167271 DOI: 10.1016/j.bbcan.2022.188807] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 09/12/2022] [Accepted: 09/21/2022] [Indexed: 11/22/2022]
Abstract
Kinins are bioactive peptides generated in the inflammatory milieu of the tissue microenvironment, which is involved in cancer progression and inflammatory response. Kinins signals through activation of two G-protein coupled receptors; inducible Bradykinin Receptor B1 (B1R) and constitutive receptor B2 (B2R). Activation of kinin receptors and its cross-talk with receptor tyrosine kinases activates multiple signaling pathways, including ERK/MAPK, PI3K, PKC, and p38 pathways regulating cancer hallmarks. Perturbations of the kinin-mediated events are implicated in various aspects of cancer invasion, matrix remodeling, and metastasis. In the tumor microenvironment, kinins initiate fibroblast activation, mesenchymal stem cell interactions, and recruitment of immune cells. Albeit the precise nature of kinin function in the metastasis and tumor microenvironment are not completely clear yet, several kinin receptor antagonists show anti-metastatic potential. Here, we showcase an overview of the complex biology of kinins and their role in cancer pathogenesis and therapeutic aspects.
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Zhang X, Connelly J, Chao Y, Wang QJ. Multifaceted Functions of Protein Kinase D in Pathological Processes and Human Diseases. Biomolecules 2021; 11:biom11030483. [PMID: 33807058 PMCID: PMC8005150 DOI: 10.3390/biom11030483] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 03/13/2021] [Accepted: 03/15/2021] [Indexed: 02/06/2023] Open
Abstract
Protein kinase D (PKD) is a family of serine/threonine protein kinases operating in the signaling network of the second messenger diacylglycerol. The three family members, PKD1, PKD2, and PKD3, are activated by a variety of extracellular stimuli and transduce cell signals affecting many aspects of basic cell functions including secretion, migration, proliferation, survival, angiogenesis, and immune response. Dysregulation of PKD in expression and activity has been detected in many human diseases. Further loss- or gain-of-function studies at cellular levels and in animal models provide strong support for crucial roles of PKD in many pathological conditions, including cancer, metabolic disorders, cardiac diseases, central nervous system disorders, inflammatory diseases, and immune dysregulation. Complexity in enzymatic regulation and function is evident as PKD isoforms may act differently in different biological systems and disease models, and understanding the molecular mechanisms underlying these differences and their biological significance in vivo is essential for the development of safer and more effective PKD-targeted therapies. In this review, to provide a global understanding of PKD function, we present an overview of the PKD family in several major human diseases with more focus on cancer-associated biological processes.
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Yuan H, Wang D, Zhang Y, Geng J. Atorvastatin attenuates vascular remodelling in spontaneously hypertensive rats via the protein kinase D/extracellular signal-regulated kinase 5 pathway. Clin Exp Pharmacol Physiol 2020; 47:1429-1438. [PMID: 32259311 DOI: 10.1111/1440-1681.13319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 03/15/2020] [Accepted: 03/30/2020] [Indexed: 01/20/2023]
Abstract
The present study was conducted to determine whether atorvastatin reduces hypertension-induced vascular remodelling and whether its effects involve protein kinase D (PKD) and extracellular signal-regulated kinase 5 (ERK5). We used 16-week-old spontaneously hypertensive rats (SHRs) and age-matched Wistar-Kyoto (WKY) rats. The blood pressure and serum lipid concentration were measured. Changes in the vascular morphology and histology were examined using H&E, Masson' s trichrome, and Sirius Red staining. The media thickness (MT), ratio of MT to lumen diameter (LD) (MT/LD), collagen volume fraction (CVF) and hydroxyproline content were measured to evaluate vascular remodelling. Atorvastatin (50 mg/kg/day) was administered for 8 weeks. Increased blood pressure and vascular remodelling were more prominent in SHRs than in WKY rats. SHRs also had elevated PKD and ERK5 activation. The systolic blood pressure, MT/LD ratio, and hydroxyproline content were positively correlated with the activation level of PKD and ERK5 in SHRs. Atorvastatin significantly attenuated the activation of PKD and ERK5. Overall, this study demonstrated that atorvastatin could reverse vascular remodelling in SHRs. The PKD/ERK5 signalling pathway might be important for elucidating the beneficial pleiotropic effects of atorvastatin on vascular remodelling.
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Affiliation(s)
- Haitao Yuan
- Department of Cardiology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China
| | - Deyu Wang
- Department of Cardiology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China
| | - Yuying Zhang
- Department of Cardiology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China
| | - Jing Geng
- Department of Cardiology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China
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Plummer R, Hu GF, Liu T, Yoo J. Angiogenin regulates PKD activation and COX-2 expression induced by TNF-α and bradykinin in the colonic myofibroblast. Biochem Biophys Res Commun 2020; 525:870-876. [PMID: 32171525 DOI: 10.1016/j.bbrc.2020.02.169] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 02/27/2020] [Indexed: 02/06/2023]
Abstract
INTRODUCTION The myofibroblast is a gastrointestinal stromal cell that is a target of tumor necrosis factor-alpha (TNF-α), a pro-inflammatory cytokine strongly implicated in colitis-associated cancer. Crosstalk between TNF-α and other pro-inflammatory mediators amplify inflammatory signaling but the mechanism is unknown. Angiogenin (ANG) is a 14-kDa angiogenesis protein that is regulated in patients with inflammatory bowel disease. However, the role of ANG on inflammatory mediator crosstalk in the myofibroblast is unknown. METHODS The human colonic myofibroblast cell line 18Co, as well as primary mouse and human colonic myofibroblasts, were exposed to TNF-α (10 ng/ml) and bradykinin (BK, 100 nM). ANG was quantified by ELISA. The expression of cyclo-oxygenase-2 (COX-2) and phosphorylation of PKD was assessed by Western Blot. RESULTS Primary mouse and human colonic myofibroblasts exposed to TNF-α/BK led to enhanced PKD phosphorylation and synergistic COX-2 expression. 18Co cells secrete high levels of ANG (24h, 265 ± 5 pg/ml). The monoclonal antibody 26-2F, which neutralizes ANG, inhibited TNF-α/BK-mediated PKD phosphorylation and synergistic COX-2 expression in primary human myofibroblasts. Likewise, in primary mouse myofibroblasts that do not express ANG (ANG-KO), TNF-α/BK failed to enhance PKD phosphorylation and COX-2 expression. CONCLUSIONS TNF-α/BK enhance PKD phosphorylation and COX-2 expression in primary mouse and human colonic myofibroblasts. Angiogenin is produced by the myofibroblast, and inhibition of ANG signaling, either by its absence (ANG-KO) or by pharmacologic inhibition, blocks enhanced PKD phosphorylation and synergistic COX-2 expression induced by TNF-α/BK. ANG mediates crosstalk signaling between TNF-α/BK in the regulation of stroma-derived COX-2 and may be a novel therapeutic target for the management of colitis-associated cancer.
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Affiliation(s)
- Robert Plummer
- Department of Medicine, Tufts University School of Medicine, Tufts Medical Center, Boston, MA, 02111, USA
| | - Guo-Fu Hu
- Department of Medicine, Tufts University School of Medicine, Tufts Medical Center, Boston, MA, 02111, USA
| | - Tiegang Liu
- Department of Surgery, Harvard Medical School, Brigham and Women's Hospital, Boston, MA, 02115, USA
| | - James Yoo
- Department of Surgery, Harvard Medical School, Brigham and Women's Hospital, Boston, MA, 02115, USA.
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Protein kinase Cε regulates nuclear translocation of extracellular signal-regulated kinase, which contributes to bradykinin-induced cyclooxygenase-2 expression. Sci Rep 2018; 8:8535. [PMID: 29867151 PMCID: PMC5986758 DOI: 10.1038/s41598-018-26473-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 05/04/2018] [Indexed: 01/18/2023] Open
Abstract
The proinflammatory mediator bradykinin stimulated cyclooxygenase-2 (COX-2) expression and subsequently prostaglandin E2 synthesis in dermal fibroblasts. The involvement of B2 receptors and Gαq in the role of bradykinin was suggested by using pharmacological inhibitors. The PKC activator PMA stimulated COX-2 mRNA expression. Bradykinin failed to induce COX-2 mRNA expression in the presence of PKC inhibitors, whereas the effect of bradykinin was observed in the absence of extracellular Ca2+. Bradykinin-induced COX-2 mRNA expression was inhibited in cells transfected with PKCε siRNA. These observations suggest that the novel PKCε is concerned with bradykinin-induced COX-2 expression. Bradykinin-induced PKCε phosphorylation and COX-2 mRNA expression were inhibited by an inhibitor of 3-phosphoinositide-dependent protein kinase-1 (PDK-1), and bradykinin-induced PDK-1 phosphorylation was inhibited by phospholipase D (PLD) inhibitors, suggesting that PLD/PDK-1 pathway contributes to bradykinin-induced PKCε activation. Pharmacological and knockdown studies suggest that the extracellular signal-regulated kinase 1 (ERK1) MAPK signaling is involved in bradykinin-induced COX-2 expression. Bradykinin-induced ERK phosphorylation was attenuated in the cells pretreated with PKC inhibitors or transfected with PKCε siRNA. We observed the interaction between PKCε and ERK by co-immunoprecipitation experiments. These observations suggest that PKCε activation contributes to the regulation of ERK1 activation. Bradykinin stimulated the accumulation of phosphorylated ERK in the nuclear fraction, that was inhibited in the cells treated with PKC inhibitors or transfected with PKCε siRNA. Consequently, we concluded that bradykinin activates PKCε via the PLD/PDK-1 pathway, which subsequently induces activation and translocation of ERK1 into the nucleus, and contributes to COX-2 expression for prostaglandin E2 synthesis in dermal fibroblasts.
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Geng J, Zhao Z, Yang L, Zhang M, Liu X. Protein Kinase D was involved in vascular remodeling in spontaneously hypertensive rats. Clin Exp Hypertens 2018; 41:299-306. [PMID: 29781735 DOI: 10.1080/10641963.2018.1469647] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The present study was designed to determine the role of PKD in vascular remodeling (VR) in Spontaneously hypertensive rats (SHRs). Increased SBP, VR and PKD activation were prominent in SHRs. The SBP has a positive correlation with the activation of PKD in SHRs. The ratio of media to lumen (MT/LD), volume fraction of collagen (VFC), hydroxyproline, IL-6, TNF-α and nitrotyrosine content were significantly related to the activated PKD. It may be concluded that PKD plays a central role in VR, and the mechanism may be related to its regulation of hypertrophy, fibrosis, inflammation and oxidative stress.
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Affiliation(s)
- Jing Geng
- a Shandong provincial Hospital Affiliated to Shandong University , Jinan , Shandong , PR China
| | - Zhuo Zhao
- b Department of Cardiology Ji'nan Central Hospital , Jinan , Shandong , PR China
| | - Le Yang
- a Shandong provincial Hospital Affiliated to Shandong University , Jinan , Shandong , PR China
| | - Mingwei Zhang
- a Shandong provincial Hospital Affiliated to Shandong University , Jinan , Shandong , PR China
| | - Xiangjuan Liu
- c The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health , Shandong University Qilu Hospital , Jinan , Shandong , PR China
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Roy A, Ye J, Deng F, Wang QJ. Protein kinase D signaling in cancer: A friend or foe? Biochim Biophys Acta Rev Cancer 2017; 1868:283-294. [PMID: 28577984 DOI: 10.1016/j.bbcan.2017.05.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 05/26/2017] [Accepted: 05/27/2017] [Indexed: 12/18/2022]
Abstract
Protein kinase D is a family of evolutionarily conserved serine/threonine kinases that belongs to the Ca++/Calmodulin-dependent kinase superfamily. Signal transduction pathways mediated by PKD can be triggered by a variety of stimuli including G protein-coupled receptor agonists, growth factors, hormones, and cellular stresses. The regulatory mechanisms and physiological roles of PKD have been well documented including cell proliferation, survival, migration, angiogenesis, regulation of gene expression, and protein/membrane trafficking. However, its precise roles in disease progression, especially in cancer, remain elusive. A plethora of studies documented the cell- and tissue-specific expressions and functions of PKD in various cancer-associated biological processes, while the causes of the differential effects of PKD have not been thoroughly investigated. In this review, we have discussed the structural-functional properties, activation mechanisms, signaling pathways and physiological functions of PKD in the context of human cancer. Additionally, we have provided a comprehensive review of the reported tumor promoting or tumor suppressive functions of PKD in several major cancer types and discussed the discrepancies that have been raised on PKD as a major regulator of malignant transformation.
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Affiliation(s)
- Adhiraj Roy
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, 200 Lothrop Street, Pittsburgh, PA 15261, USA
| | - Jing Ye
- Department of Anesthesiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Fan Deng
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Qiming Jane Wang
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, 200 Lothrop Street, Pittsburgh, PA 15261, USA.
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Chu E, Saini S, Liu T, Yoo J. Bradykinin stimulates protein kinase D-mediated colonic myofibroblast migration via cyclooxygenase-2 and heat shock protein 27. J Surg Res 2016; 209:191-198. [PMID: 28032559 DOI: 10.1016/j.jss.2016.10.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 10/05/2016] [Accepted: 10/13/2016] [Indexed: 12/20/2022]
Abstract
BACKGROUND Inflammatory bowel disease is characterized by episodic intestinal injury and repair. Myofibroblasts are gastrointestinal tract stromal cells that regulate the reparative process and are known targets of inflammatory mediators including bradykinin (BK). However, the mechanisms through which inflammation regulates myofibroblast-induced wound healing remain incompletely understood. Here, we demonstrate, for the first time, that BK stimulates myofibroblast migration through protein kinase D (PKD)-mediated activation of the cyclooxygenase-2 (COX-2) and heat shock protein 27 (Hsp27) pathways. MATERIALS AND METHODS CCD-18Co is a human colonic myofibroblast cell line used from passages 8 to 14. An in vitro scratch assay assessed the effect of BK (100 nM) on myofibroblast migration over 24 h in the presence or absence of several inhibitors (CID755673 [10 μM] and NS398 [10 μM]). Hsp27 small interfering RNA evaluated the effect of Hsp27 on colonic myofibroblast migration. Antibodies to pPKD, pHsp27, and COX-2 evaluated expression levels by Western blot. RESULTS BK stimulated myofibroblast migration over 24 h. BK also led to rapid and sustained phosphorylation of PKD at Ser-916, rapid phosphorylation of Hsp27 at Ser-82, and increased COX-2 expression over 4 h. BK-mediated COX-2 expression and Hsp27 phosphorylation were both inhibited by the PKD inhibitor CID755673. Similarly, BK-induced myofibroblast migration was significantly inhibited by CID755673 (P < 0.05), by the direct COX-2 inhibitor NS398 (P < 0.05), and by Hsp27 small interfering RNA (P < 0.05). CONCLUSIONS BK stimulates myofibroblast migration through PKD-mediated activation of COX-2 and Hsp27. PKD, COX-2, and Hsp27 all appear to regulate myofibroblast cell migration, a stromal population that may play an important role in mucosal healing in the setting of inflammation.
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Affiliation(s)
- Eric Chu
- Department of Surgery, Tufts Medical Center, Tufts University School of Medicine, Boston, Massachusetts
| | - Shyla Saini
- Department of Surgery, Tufts Medical Center, Tufts University School of Medicine, Boston, Massachusetts
| | - Tiegang Liu
- Department of Surgery, Tufts Medical Center, Tufts University School of Medicine, Boston, Massachusetts
| | - James Yoo
- Department of Surgery, Tufts Medical Center, Tufts University School of Medicine, Boston, Massachusetts.
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Saini S, Liu T, Yoo J. TNF-α stimulates colonic myofibroblast migration via COX-2 and Hsp27. J Surg Res 2016; 204:145-52. [PMID: 27451881 DOI: 10.1016/j.jss.2016.04.034] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 03/02/2016] [Accepted: 04/15/2016] [Indexed: 12/25/2022]
Abstract
BACKROUND Crohn's disease (CD) is a chronic inflammatory enteropathy characterized by fibrotic strictures. Myofibroblasts (MFBs) are stromal cells of the gastrointestinal tract found in increased numbers in patients with CD and represent the key effector cells involved in pathologic fibrosis. MFB is a known target of tumor necrosis factor alpha (TNF-α), a proinflammatory cytokine strongly implicated in the pathophysiology of CD. However, the precise mechanisms through which TNF-α contributes to fibrosis remain incompletely understood. Here, we demonstrate for the first time that TNF-α increases MFB migration through the cyclooxygenase 2 (COX-2) and heat-shock protein 27 (Hsp27) pathways. MATERIALS AND METHODS The human colonic MFB cell line 18Co was grown to confluence on 35 × 10 mm cell culture dishes and used from passages 8-14. An in vitro scratch assay assessed the effect of TNF-α (10 ng/mL) on MFB migration over 24 h in the presence or absence of several inhibitors (NS398, SB203580, Hsp27 siRNA). RESULTS TNF-α significantly increased MFB migration over 24 h. TNF-α also led to the increased expression of COX-2 and stimulated rapid phosphorylation of Hsp27 at serine 82. TNF-α-induced COX-2 expression, Hsp27 phosphorylation, and MFB migration were all significantly inhibited by the P38 MAPK inhibitor SB203580 (P < 0.05). TNF-α-induced MFB migration was also significantly inhibited by NS398 (P < 0.05), a direct inhibitor of COX-2, and by siRNA targeting Hsp27 (P < 0.05). CONCLUSIONS TNF-α stimulates colonic MFB migration through P38 MAPK-mediated activation of COX-2 and Hsp27. Further elucidating these inflammatory signaling pathways may lead to novel therapeutic targets for the treatment of CD-related fibrosis and strictures.
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Affiliation(s)
- Shyla Saini
- Department of Surgery, Tufts Medical Center, Tufts University School of Medicine, Boston, Massachusetts
| | - Tiegang Liu
- Department of Surgery, Tufts Medical Center, Tufts University School of Medicine, Boston, Massachusetts
| | - James Yoo
- Department of Surgery, Tufts Medical Center, Tufts University School of Medicine, Boston, Massachusetts.
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Sánchez-Ruiloba L, Aicart-Ramos C, García-Guerra L, Pose-Utrilla J, Rodríguez-Crespo I, Iglesias T. Protein kinase D interacts with neuronal nitric oxide synthase and phosphorylates the activatory residue serine 1412. PLoS One 2014; 9:e95191. [PMID: 24740233 PMCID: PMC3989272 DOI: 10.1371/journal.pone.0095191] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 03/24/2014] [Indexed: 12/20/2022] Open
Abstract
Neuronal Nitric Oxide Synthase (nNOS) is the biosynthetic enzyme responsible for nitric oxide (·NO) production in muscles and in the nervous system. This constitutive enzyme, unlike its endothelial and inducible counterparts, presents an N-terminal PDZ domain known to display a preference for PDZ-binding motifs bearing acidic residues at -2 position. In a previous work, we discovered that the C-terminal end of two members of protein kinase D family (PKD1 and PKD2) constitutes a PDZ-ligand. PKD1 has been shown to regulate multiple cellular processes and, when activated, becomes autophosphorylated at Ser916, a residue located at -2 position of its PDZ-binding motif. Since nNOS and PKD are spatially enriched in postsynaptic densities and dendrites, the main objective of our study was to determine whether PKD1 activation could result in a direct interaction with nNOS through their respective PDZ-ligand and PDZ domain, and to analyze the functional consequences of this interaction. Herein we demonstrate that PKD1 associates with nNOS in neurons and in transfected cells, and that kinase activation enhances PKD1-nNOS co-immunoprecipitation and subcellular colocalization. However, transfection of mammalian cells with PKD1 mutants and yeast two hybrid assays showed that the association of these two enzymes does not depend on PKD1 PDZ-ligand but its pleckstrin homology domain. Furthermore, this domain was able to pull-down nNOS from brain extracts and bind to purified nNOS, indicating that it mediates a direct PKD1-nNOS interaction. In addition, using mass spectrometry we demonstrate that PKD1 specifically phosphorylates nNOS in the activatory residue Ser1412, and that this phosphorylation increases nNOS activity and ·NO production in living cells. In conclusion, these novel findings reveal a crucial role of PKD1 in the regulation of nNOS activation and synthesis of ·NO, a mediator involved in physiological neuronal signaling or neurotoxicity under pathological conditions such as ischemic stroke or neurodegeneration.
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Affiliation(s)
- Lucía Sánchez-Ruiloba
- Instituto de Investigaciones Biomédicas “Alberto Sols”, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), Madrid, Spain
- CIBERNED, Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Instituto de Salud Carlos III, Madrid, Spain
| | - Clara Aicart-Ramos
- Departamento de Bioquímica y Biología Molecular I, Universidad Complutense de Madrid (UCM), Madrid, Spain
| | - Lucía García-Guerra
- Instituto de Investigaciones Biomédicas “Alberto Sols”, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), Madrid, Spain
- CIBERNED, Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Instituto de Salud Carlos III, Madrid, Spain
| | - Julia Pose-Utrilla
- Instituto de Investigaciones Biomédicas “Alberto Sols”, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), Madrid, Spain
- CIBERNED, Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Instituto de Salud Carlos III, Madrid, Spain
| | - Ignacio Rodríguez-Crespo
- Departamento de Bioquímica y Biología Molecular I, Universidad Complutense de Madrid (UCM), Madrid, Spain
- * E-mail: (IRC); (TI)
| | - Teresa Iglesias
- Instituto de Investigaciones Biomédicas “Alberto Sols”, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), Madrid, Spain
- CIBERNED, Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Instituto de Salud Carlos III, Madrid, Spain
- * E-mail: (IRC); (TI)
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Khalil H, Nie W, Edwards RA, Yoo J. Isolation of primary myofibroblasts from mouse and human colon tissue. J Vis Exp 2013. [PMID: 24145735 DOI: 10.3791/50611] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The myofibroblast is a stromal cell of the gastrointestinal (GI) tract that has been gaining considerable attention for its critical role in many GI functions. While several myofibroblast cell lines are commercially available to study these cells in vitro, research results from a cell line exposed to experimental cell culture conditions have inherent limitations due to the overly reductionist nature of the work. Use of primary myofibroblasts offers a great advantage in terms of confirming experimental findings identified in a cell line. Isolation of primary myofibroblasts from an animal model allows for the study of myofibroblasts under conditions that more closely mimic the disease state being studied. Isolation of primary myofibroblasts from human colon tissue provides arguably the most relevant experimental data, since the cells come directly from patients with the underlying disease. We describe a well-established technique that can be utilized to isolate primary myofibroblasts from both mouse and human colon tissue. These isolated cells have been characterized to be alpha-smooth muscle actin and vimentin-positive, and desmin-negative, consistent with subepithelial intestinal myofibroblasts. Primary myofibroblast cells can be grown in cell culture and used for experimental purposes over a limited number of passages.
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Yoo J, Rodriguez Perez CE, Nie W, Sinnett-Smith J, Rozengurt E. TNF-α and LPA promote synergistic expression of COX-2 in human colonic myofibroblasts: role of LPA-mediated transactivation of upregulated EGFR. BMC Gastroenterol 2013; 13:90. [PMID: 23688423 PMCID: PMC3663734 DOI: 10.1186/1471-230x-13-90] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 05/15/2013] [Indexed: 02/06/2023] Open
Abstract
Background Enhanced EGF receptor (EGFR) signaling is a hallmark of many human cancers, though the role of enhanced EGFR signaling within the surrounding tumor stroma has not been well studied. The myofibroblast is an important stromal cell that demonstrates enhanced EGFR expression in the setting of inflammation, though the functional relevance is not known. We recently reported that TNF-α and the G protein-coupled receptor (GPCR) agonist lysophosphatidic acid (LPA) lead to synergistic cyclo-oxygenase-2 (COX-2) expression, an enzyme strongly associated with the development of colitis-associated cancer. Here, we investigate whether EGFR signaling plays a role in the synergistic COX-2 expression induced by LPA and TNF-α. Methods 18Co cells, a model of human colonic myofibroblasts, were grown to confluence on 35 × 10mm cell culture dishes and were used from passages 10–14. 18Co cells were treated with TNF-α (8.3 ng/ml) and LPA (10 μM). EGFR and COX-2 protein expression, Y1068 phosphorylation, and p42/44 MAPK phosphorylation were assessed by Western Blot, in the presence and absence of various inhibitors. Results Exposure of 18Co cells to either TNF-α or LPA alone had no effect on EGFR autophosphorylation at Y1068. However, chronic exposure to TNF-α led to upregulation of EGFR in association with sustained LPA-mediated EGFR phosphorylation at Y1068. TNF-α and LPA also led to sustained p42/44 MAPK phosphorylation and synergistic COX-2 expression, effects that were partially inhibited by the EGFR tyrosine kinase inhibitor AG1478. p42/44 MAPK phosphorylation and COX-2 expression were inhibited to the same degree by the MMP inhibitors GM6001 and BB-94, suggesting that LPA-mediated EGFR transactivation involved MMP-mediated release of EGFR ligands from the cell surface. The Src inhibitor SU6556 inhibited TNF-α/LPA-mediated EGFR phosphorylation at Y1068, p42/44 MAPK phosphorylation, and COX-2 expression in a dose-dependent fashion, suggesting an upstream role of Src in the transactivation of EGFR. Conclusion Synergistic COX-2 expression induced by TNF-α and LPA involves Src/MMP-mediated transactivation of EGFR and downstream p42/44 MAPK activation in human colonic myofibroblasts. Enhanced EGFR expression induced by TNF-α promotes GPCR-mediated EGFR transactivation in colonic myofibroblasts, providing an important mechanism for stromal COX-2 over-expression that may predispose to the development of colitis-associated cancer.
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Ziogas DC, Gras-Miralles B, Mustafa S, Geiger BM, Najarian RM, Nagel JM, Flier SN, Popov Y, Tseng YH, Kokkotou E. Anti-melanin-concentrating hormone treatment attenuates chronic experimental colitis and fibrosis. Am J Physiol Gastrointest Liver Physiol 2013; 304:G876-84. [PMID: 23538494 PMCID: PMC3652072 DOI: 10.1152/ajpgi.00305.2012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Fibrosis represents a major complication of several chronic diseases, including inflammatory bowel disease (IBD). Treatment of IBD remains a clinical challenge despite several recent therapeutic advances. Melanin-concentrating hormone (MCH) is a hypothalamic neuropeptide shown to regulate appetite and energy balance. However, accumulating evidence suggests that MCH has additional biological effects, including modulation of inflammation. In the present study, we examined the efficacy of an MCH-blocking antibody in treating established, dextran sodium sulfate-induced experimental colitis. Histological and molecular analysis of mouse tissues revealed that mice receiving anti-MCH had accelerated mucosal restitution and lower colonic expression of several proinflammatory cytokines, as well as fibrogenic genes, including COL1A1. In parallel, they spared collagen deposits seen in the untreated mice, suggesting attenuated fibrosis. These findings raised the possibility of perhaps direct effects of MCH on myofibroblasts. Indeed, in biopsies from patients with IBD, we demonstrate expression of the MCH receptor MCHR1 in α-smooth muscle actin(+) subepithelial cells. CCD-18Co cells, a primary human colonic myofibroblast cell line, were also positive for MCHR1. In these cells, MCH acted as a profibrotic modulator by potentiating the effects of IGF-1 and TGF-β on proliferation and collagen production. Thus, by virtue of combined anti-inflammatory and anti-fibrotic effects, blocking MCH might represent a compelling approach for treating IBD.
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Affiliation(s)
| | | | | | | | | | | | | | - Yury Popov
- 1Beth Israel Deaconess Medical Center and
| | - Yu-Hua Tseng
- 2Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts
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Giménez-Bastida JA, Larrosa M, González-Sarrías A, Tomás-Barberán F, Espín JC, García-Conesa MT. Intestinal ellagitannin metabolites ameliorate cytokine-induced inflammation and associated molecular markers in human colon fibroblasts. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2012; 60:8866-8876. [PMID: 22463485 DOI: 10.1021/jf300290f] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Pomegranate ellagitannins (ETs) are transformed in the gut to ellagic acid (EA) and its microbiota metabolites, urolithin A (Uro-A) and urolithin B (Uro-B). These compounds exert anti-inflammatory effects in vitro and in vivo. The aim of this study was to investigate the effects of Uro-A, Uro-B, and EA on colon fibroblasts, cells that play a key role in intestinal inflammation. CCD18-Co colon fibroblasts were exposed to a mixture of Uro-A, Uro-B, and EA, at concentrations comparable to those found in the colon (40 μM Uro-A, 5 μM Uro-B, 1 μM EA), both in the presence or in the absence of IL-1β (1 ng/mL) or TNF-α (50 ng/mL), and the effects on fibroblast migration and monocyte adhesion were determined. The levels of several growth factors and adhesion cytokines were also measured. The mixture of metabolites significantly inhibited colon fibroblast migration (∼70%) and monocyte adhesion to fibroblasts (∼50%). These effects were concomitant with a significant down-regulation of the levels of PGE(2), PAI-1, and IL-8, as well as other key regulators of cell migration and adhesion. Of the three metabolites tested, Uro-A exhibited the most significant anti-inflammatory effects. The results show that a combination of the ET metabolites found in colon, urolithins and EA, at concentrations achievable in the intestine after the consumption of pomegranate, was able to moderately improve the inflammatory response of colon fibroblasts and suggest that consumption of ET-containing foods has potential beneficial effects on gut inflammatory diseases.
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Affiliation(s)
- Juan A Giménez-Bastida
- Research Group on Quality, Safety and Bioactivity of Plant Foods, Department of Food Science and Technology, CEBAS-CSIC , P.O. Box 164, 30100 Campus de Espinardo, Murcia, Spain
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Yoo J, Perez CER, Nie W, Edwards RA, Sinnett-Smith J, Rozengurt E. TNF-α induces upregulation of EGFR expression and signaling in human colonic myofibroblasts. Am J Physiol Gastrointest Liver Physiol 2012; 302:G805-14. [PMID: 22301110 PMCID: PMC3355565 DOI: 10.1152/ajpgi.00522.2011] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The myofibroblast has recently been identified as an important mediator of tumor necrosis factor-α (TNF-α)-associated colitis and cancer, but the mechanism(s) involved remains incompletely understood. Recent evidence suggests that TNF-α is a central regulator of multiple inflammatory signaling cascades. One important target of TNF-α may be the signaling pathway downstream of the epidermal growth factor receptor (EGFR), which has been associated with many human cancers. Here, we show that long-term exposure of 18Co cells, a model of human colonic myofibroblasts, with TNF-α led to a striking increase in cell surface EGFR expression, an effect that was completely inhibited by cycloheximide. Subsequent EGFR binding by EGF and heparin binding (HB)-EGF was associated with enhanced EGFR tyrosine kinase activity, prolonged ERK activation, and a significant increase in cyclooxygenase-2 (COX-2) expression compared with 18Co cells treated with EGF and HB-EGF alone. TNF-α also increased EGFR expression and signaling in primary myofibroblasts isolated from human colon tissue. TNF-α-induced upregulation of EGFR may be a plausible mechanism to explain the exaggerated cellular responsiveness that characterizes inflammatory bowel disease and that may contribute to a microenvironment that predisposes to colitis-associated cancer through enhanced COX-2 expression.
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Affiliation(s)
- James Yoo
- Department of Surgery, David Geffen School of Medicine, CURE: Digestive Diseases Research Center and Molecular Biology Institute, University of California, Los Angeles, CA 90095, USA.
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Bassyouni IH, Talaat RM, Salem TA. Serum Concentrations of Cyclooxygenase-2 in Patients with Systemic Sclerosis: Association with Lower Frequency of Pulmonary Fibrosis. J Clin Immunol 2011; 32:124-30. [DOI: 10.1007/s10875-011-9601-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2011] [Accepted: 09/19/2011] [Indexed: 02/03/2023]
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Yoo J, Rodriguez Perez CE, Nie W, Sinnett-Smith J, Rozengurt E. Protein kinase D1 mediates synergistic MMP-3 expression induced by TNF-α and bradykinin in human colonic myofibroblasts. Biochem Biophys Res Commun 2011; 413:30-5. [PMID: 21867693 DOI: 10.1016/j.bbrc.2011.08.029] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Accepted: 08/07/2011] [Indexed: 01/28/2023]
Abstract
Stromal myofibroblasts regulate extracellular matrix components through the secretion of matrix metalloproteinases such as MMP-3. Both myofibroblasts and MMP-3 have been implicated in colonic inflammation and cancer but the regulatory signaling mechanism(s) are unknown. Exposure of the human colonic myofibroblast cell line 18Co to TNF-α and bradykinin induced synergistic MMP-3 mRNA and protein expression, which were blocked by the preferential PKC inhibitors GF109203X and Go6983 and by the MEK inhibitor U0126. Transfection with siRNA targeting PKD1, a known downstream target of both bradykinin and PKC, completely inhibited MMP-3 mRNA and protein expression. Our results imply that TNF-α and bradykinin amplify MMP-3 expression at a transcriptional level through a signaling cascade involving PKC, PKD1, and MEK. PKD1 plays a critical role in the expression of MMP-3 in human colonic myofibroblasts, and may contribute to the pathophysiology underlying colitis-associated cancer.
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Affiliation(s)
- James Yoo
- Departments of Surgery and Medicine, David Geffen School of Medicine, CURE: Digestive Diseases Research Center and Molecular Biology Institute, University of California, Los Angeles, CA 90095, USA.
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Rozengurt E. Protein kinase D signaling: multiple biological functions in health and disease. Physiology (Bethesda) 2011; 26:23-33. [PMID: 21357900 DOI: 10.1152/physiol.00037.2010] [Citation(s) in RCA: 176] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Protein kinase D (PKD) is an evolutionarily conserved protein kinase family with structural, enzymological, and regulatory properties different from the PKC family members. Signaling through PKD is induced by a remarkable number of stimuli, including G-protein-coupled receptor agonists and polypeptide growth factors. PKD1, the most studied member of the family, is increasingly implicated in the regulation of a complex array of fundamental biological processes, including signal transduction, cell proliferation and differentiation, membrane trafficking, secretion, immune regulation, cardiac hypertrophy and contraction, angiogenesis, and cancer. PKD mediates such a diverse array of normal and abnormal biological functions via dynamic changes in its spatial and temporal localization, combined with its distinct substrate specificity. Studies on PKD thus far indicate a striking diversity of both its signal generation and distribution and its potential for complex regulatory interactions with multiple downstream pathways, often regulating the subcellular localization of its targets.
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Affiliation(s)
- Enrique Rozengurt
- Department of Medicine, Division of Digestive Diseases, David Geffen School of Medicine, CURE: Digestive Diseases Research Center and Molecular Biology Institute, University of California, Los Angeles, California, USA.
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Rodriguez Perez CE, Nie W, Sinnett-Smith J, Rozengurt E, Yoo J. TNF-α potentiates lysophosphatidic acid-induced COX-2 expression via PKD in human colonic myofibroblasts. Am J Physiol Gastrointest Liver Physiol 2011; 300:G637-46. [PMID: 21292998 PMCID: PMC3074991 DOI: 10.1152/ajpgi.00381.2010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The myofibroblast (MFB) has recently been identified as an important mediator of tumor necrosis factor-α (TNF-α)-associated colitis and cancer, but the mechanism(s) involved remains incompletely understood. Here, we show that treatment of 18Co cells, a model of human colonic MFBs, with TNF-α and lysophosphatidic acid (LPA) induced striking synergistic cyclooxygenase-2 (COX-2) protein expression and production of PGE(2). This effect was prevented by the LPA(1) receptor antagonist Ki16425, the G(iα)-specific inhibitor pertussis toxin, and by the preferential protein kinase (PK) C inhibitors GF109203X and Go6983. As a known downstream target of LPA and PKC, we tested whether PKD, recently implicated in the regulation of COX-2 expression in MFB, was involved in this response. TNF-α, while having no detectable effect on the activation of PKD when added alone, augmented PKD activation stimulated by LPA, as measured by PKD autophosphorylation at Ser(910). LPA-induced PKD activation was also inhibited by Ki16425, pertussis toxin, GF109203X, and Go6983. Transfection of 18Co cells with short interfering RNA targeting PKD completely inhibited the synergistic increase in COX-2 protein, demonstrating a critical role of PKD in this response. Our results imply that cross talk between TNF-α and LPA results in the amplification of COX-2 protein expression via a conserved PKD-dependent signaling pathway that appears to involve the LPA(1) receptor and the G protein G(iα). PKD plays a critical role in the expression of COX-2 in human colonic MFBs and may contribute to an inflammatory microenvironment that promotes tumor growth.
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Affiliation(s)
- Citlali Ekaterina Rodriguez Perez
- Departments of Surgery and Medicine, David Geffen School of Medicine, CURE: Digestive Diseases Research Center and Molecular Biology Institute, University of California, Los Angeles, California
| | - Wenxian Nie
- Departments of Surgery and Medicine, David Geffen School of Medicine, CURE: Digestive Diseases Research Center and Molecular Biology Institute, University of California, Los Angeles, California
| | - James Sinnett-Smith
- Departments of Surgery and Medicine, David Geffen School of Medicine, CURE: Digestive Diseases Research Center and Molecular Biology Institute, University of California, Los Angeles, California
| | - Enrique Rozengurt
- Departments of Surgery and Medicine, David Geffen School of Medicine, CURE: Digestive Diseases Research Center and Molecular Biology Institute, University of California, Los Angeles, California
| | - James Yoo
- Departments of Surgery and Medicine, David Geffen School of Medicine, CURE: Digestive Diseases Research Center and Molecular Biology Institute, University of California, Los Angeles, California
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Cui X, Jin Y, Poudyal D, Chumanevich AA, Davis T, Windust A, Hofseth A, Wu W, Habiger J, Pena E, Wood P, Nagarkatti M, Nagarkatti PS, Hofseth L. Mechanistic insight into the ability of American ginseng to suppress colon cancer associated with colitis. Carcinogenesis 2010; 31:1734-41. [PMID: 20729391 DOI: 10.1093/carcin/bgq163] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
We have recently shown that American ginseng (AG) prevents and treats mouse colitis. Because both mice and humans with chronic colitis have a high colon cancer risk, we tested the hypothesis that AG can be used to prevent colitis-driven colon cancer. Using the azoxymethane (AOM)/dextran sulfate sodium (DSS) mouse model of ulcerative colitis, we show that AG can suppress colon cancer associated with colitis. To explore the molecular mechanisms of the anticancer effects of AG, we also carried out antibody array experiments on colon cells isolated at a precancerous stage. We found there were 82 protein end points that were either significantly higher (41 proteins) or significantly lower (41 proteins) in the AOM + DSS group compared with the AOM-alone (control) group. In contrast, there were only 19 protein end points that were either significantly higher (10 proteins) or significantly lower (9 proteins) in the AOM + DSS + AG group compared with the AOM-alone (control) group. Overall, these results suggest that AG keeps the colon environment in metabolic equilibrium when mice are treated with AOM + DSS and gives insight into the mechanisms by which AG protects from colon cancer associated with colitis.
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Affiliation(s)
- Xiangli Cui
- Department of Pharmaceutical and Biomedical Sciences, South Carolina College of Pharmacy, University of South Carolina and Medical University of South Carolina, SC 29208, USA
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Role of protein kinase D signaling in pancreatic cancer. Biochem Pharmacol 2010; 80:1946-54. [PMID: 20621068 DOI: 10.1016/j.bcp.2010.07.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Revised: 06/29/2010] [Accepted: 07/01/2010] [Indexed: 11/20/2022]
Abstract
Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers with dismal survival rates. Its intransigence to conventional therapy renders PDAC an aggressive disease with early metastatic potential. Thus, novel targets for PDAC therapy are urgently needed. Multiple signal transduction pathways are implicated in progression of PDAC. These pathways stimulate production of intracellular messengers in their target cells to modify their behavior, including the lipid-derived diacylglycerol (DAG). One of the prominent intracellular targets of DAG is the protein kinase C (PKC) family. However, the mechanisms by which PKC-mediated signals are decoded by the cell remain incompletely understood. Protein kinase D1 (PKD or PKD1, initially called atypical PKCμ), is the founding member of a novel protein kinase family that includes two additional protein kinases that share extensive overall homology with PKD, termed PKD2, and PKD3. The PKD family occupies a unique position in the signal transduction pathways initiated by DAG and PKC. PKD lies downstream of PKCs in a novel signal transduction pathway implicated in the regulation of multiple fundamental biological processes. We and others have shown that PKD-mediated signaling pathways promote mitogenesis and angiogenesis in PDAC. Our recent observations demonstrate that PKD also potentiates chemoresistance and invasive potential of PDAC cells. This review will briefly highlight diverse biological roles of PKD family in multiple neoplasias including PDAC. Further, this review will underscore our latest advancement with the development of a potent PKD family inhibitor and its effect both in vitro and in vivo in PDAC.
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