1
|
Zhang Y, Yang X, Li Z, Bu K, Li T, Ma Z, Wang B, Ma L, Lu H, Zhang K, Liu L, Zhao Y, Zhu Y, Qin J, Cui J, Liu L, Liu S, Fan P, Liu X. Pyk2/MCU Pathway as a New Target for Reversing Atherosclerosis. Front Cell Dev Biol 2021; 9:651579. [PMID: 34026753 PMCID: PMC8134689 DOI: 10.3389/fcell.2021.651579] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Accepted: 03/16/2021] [Indexed: 01/08/2023] Open
Abstract
Objective: Multiple mechanisms including vascular endothelial cell damage have a critical role in the formation and development of atherosclerosis (AS), but the specific molecular mechanisms are not exactly clarified. This study aims to determine the possible roles of proline-rich tyrosine kinase 2 (Pyk2)/mitochondrial calcium uniporter (MCU) pathway in AS mouse model and H2O2-induced endothelial cell damage model and explore its possible mechanisms. Approach and Results: The AS mouse model was established using apolipoprotein E-knockout (ApoE–/–) mice that were fed with a high-fat diet. It was very interesting to find that Pyk2/MCU expression was significantly increased in the artery wall of atherosclerotic mice and human umbilical vein endothelial cells (HUVECs) attacked by hydrogen peroxide (H2O2). In addition, down-regulation of Pyk2 by short hairpin RNA (shRNA) protected HUVECs from H2O2 insult. Furthermore, treatment with rosuvastatin on AS mouse model and H2O2-induced HUVEC injury model showed a protective effect against AS by inhibiting the Pyk2/MCU pathway, which maintained calcium balance, prevented the mitochondrial damage and reactive oxygen species production, and eventually inhibited cell apoptosis. Conclusion: Our results provide important insight into the initiation of the Pyk2/MCU pathway involved in AS-related endothelial cell damage, which may be a new promising target for atherosclerosis intervention.
Collapse
Affiliation(s)
- Yingzhen Zhang
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, China.,Department of Basic Medicine, Hebei Medical University, Shijiazhuang, China
| | - Xiaoli Yang
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, China.,Affiliated Hospital of Hebei University of Engineering, Handan, China
| | - Zhongzhong Li
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Kailin Bu
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Tong Li
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Zhizhao Ma
- Neurosurgery Department, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Binbin Wang
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Lina Ma
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Honglin Lu
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Kun Zhang
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Luji Liu
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Yanying Zhao
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Yipu Zhu
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Jin Qin
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Junzhao Cui
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Lin Liu
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Shuxia Liu
- Department of Basic Medicine, Hebei Medical University, Shijiazhuang, China
| | - Ping Fan
- Department of Basic Medicine, Hebei Medical University, Shijiazhuang, China
| | - Xiaoyun Liu
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, China.,Neuroscience Research Center, Medicine and Health Institute, Hebei Medical University, Shijiazhuang, China
| |
Collapse
|
2
|
Non-alcoholic fatty liver disease: a metabolic burden promoting atherosclerosis. Clin Sci (Lond) 2021; 134:1775-1799. [PMID: 32677680 DOI: 10.1042/cs20200446] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 06/06/2020] [Accepted: 06/29/2020] [Indexed: 02/07/2023]
Abstract
Non-alcoholic fatty liver disease (NAFLD) has become the fastest growing chronic liver disease, with a prevalence of up to 25% worldwide. Individuals with NAFLD have a high risk of disease progression to cirrhosis, hepatocellular carcinoma (HCC), and liver failure. With the exception of intrahepatic burden, cardiovascular disease (CVD) and especially atherosclerosis (AS) are common complications of NAFLD. Furthermore, CVD is a major cause of death in NAFLD patients. Additionally, AS is a metabolic disorder highly associated with NAFLD, and individual NAFLD pathologies can greatly increase the risk of AS. It is increasingly clear that AS-associated endothelial cell damage, inflammatory cell activation, and smooth muscle cell proliferation are extensively impacted by NAFLD-induced systematic dyslipidemia, inflammation, oxidative stress, the production of hepatokines, and coagulations. In clinical trials, drug candidates for NAFLD management have displayed promising effects for the treatment of AS. In this review, we summarize the key molecular events and cellular factors contributing to the metabolic burden induced by NAFLD on AS, and discuss therapeutic strategies for the improvement of AS in individuals with NAFLD.
Collapse
|
3
|
Bali A, Jaggi AS. Angiotensin II-triggered kinase signaling cascade in the central nervous system. Rev Neurosci 2018; 27:301-15. [PMID: 26574890 DOI: 10.1515/revneuro-2015-0041] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 09/26/2015] [Indexed: 12/26/2022]
Abstract
Recent studies have projected the renin-angiotensin system as a central component of the physiological and pathological processes of assorted neurological disorders. Its primary effector hormone, angiotensin II (Ang II), not only mediates the physiological effects of vasoconstriction and blood pressure regulation in cardiovascular disease but is also implicated in a much wider range of neuronal activities and diseases, including Alzheimer's disease, neuronal injury, and cognitive disorders. Ang II produces different actions by acting on its two subtypes of receptors (AT1 and AT2); however, the well-known physiological actions of Ang II are mainly mediated through AT1 receptors. Moreover, recent studies also suggest the important functional role of AT2 receptor in the brain. Ang II acts on AT1 receptors and conducts its functions via MAP kinases (ERK1/2, JNK, and p38MAPK), glycogen synthase kinase, Rho/ROCK kinase, receptor tyrosine kinases (PDGF and EGFR), and nonreceptor tyrosine kinases (Src, Pyk2, and JAK/STAT). AT1R-mediated NADPH oxidase activation also leads to the generation of reactive oxygen species, widely implicated in neuroinflammation. These signaling cascades lead to glutamate excitotoxicity, apoptosis, cerebral infarction, astrocyte proliferation, nociception, neuroinflammation, and progression of other neurological disorders. The present review focuses on the Ang II-triggered signal transduction pathways in central nervous system.
Collapse
|
4
|
Zhang Z, Chu SF, Mou Z, Gao Y, Wang ZZ, Wei GN, Chen NH. Ganglioside GQ1b induces dopamine release through the activation of Pyk2. Mol Cell Neurosci 2015; 71:102-13. [PMID: 26704905 DOI: 10.1016/j.mcn.2015.12.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 12/04/2015] [Accepted: 12/15/2015] [Indexed: 10/22/2022] Open
Abstract
Growing evidence indicates that GQ1b, one of the gangliosides members, contributes to synaptic transmission and synapse formation. Previous studies have shown that GQ1b could enhance depolarization induced neurotransmitter release, while the role of GQ1b in asynchronous release is still largely unknown. Here in our result, we found low concentration of GQ1b, but not GT1b or GD1b (which were generated from GQ1b by plasma membrane-associated sialidases), evoked asynchronous dopamine (DA) release from both clonal rat pheochromocytoma PC12 cells and rat striatal slices significantly. The release peaked at 2 min after GQ1b exposure, and lasted for more than 6 min. This effect was caused by the enhancement of intracellular Ca(2+) and the activation of Pyk2. Inhibition of Pyk2 by PF-431396 (a dual inhibitor of Pyk2 and FAK) or Pyk2 siRNA abolished DA release induced by GQ1b. Moreover, Pyk2 Y402, but not other tyrosine site, was phosphorylated at the peaking time. The mutant of Pyk2 Y402 (Pyk2-Y402F) was built to confirm the essential role of Y402 activation. Further studies revealed that activated Pyk2 stimulated ERK1/2 and p-38, while only the ERK1/2 activation was indispensable for GQ1b induced DA release, which interacted with Synapsin I directly and led to its phosphorylation, then depolymerization of F-actin, thus contributed to DA release. In conclusion, low concentration of GQ1b is able to enhance asynchronous DA release through Pyk2/ERK/Synapsin I/actin pathway. Our findings provide new insights into the role of GQ1b in neuronal communication, and implicate the potential application of GQ1b in neurological disorders.
Collapse
Affiliation(s)
- Zhao Zhang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Neuroscience Center, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Shi-Feng Chu
- Key Laboratory of Diagnostics of Traditional Chinese Medicine, Collaborative Innovation Center of Digital Traditional Chinese Medicine, College of Pharmacy, Hunan University of Chinese Medicine, Changsha, China
| | - Zheng Mou
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Neuroscience Center, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Yan Gao
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Neuroscience Center, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Zhen-Zhen Wang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Neuroscience Center, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Gui-Ning Wei
- Department of Pharmacology, Guangxi Institute of Chinese Medicine & Pharmaceutical Science, Nanning, China
| | - Nai-Hong Chen
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Neuroscience Center, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China.
| |
Collapse
|
5
|
Rotfeld H, Hillman P, Ickowicz D, Breitbart H. PKA and CaMKII mediate PI3K activation in bovine sperm by inhibition of the PKC/PP1 cascade. Reproduction 2014; 147:347-56. [DOI: 10.1530/rep-13-0560] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
To enable fertilization, spermatozoa must undergo several biochemical processes in the female reproductive tract, collectively called capacitation. These processes involve protein kinase A (PKA)-dependent protein tyrosine phosphorylation including phosphatidylinositol-3-kinase (PI3K). It is not known how PKA, a serine/threonine (S/T) kinase, mediates tyrosine phosphorylation of proteins. We recently showed that inhibition of S/T phosphatase 1 (PP1) causes a significant increase in phospho-PI3K. In this study, we propose a mechanism by which PKA and PP1 mediate an increase in PI3K tyrosine phosphorylation and implicate calmodulin-dependent kinase II (CaMKII) in this process. Inhibition of sperm PP1 or PKC, stimulated CaMKII phosphorylation/activation, and inhibition of PKC enhanced PP1 phosphorylation/inactivation. Inhibition of CaMKII, using KN-93, caused significant reduction in phospho-PP1, indicating its activation. Moreover, KN-93 prevented the dephosphorylation/inactivation of PKC. We therefore suggest that CaMKII inhibits PKC, leading to PP1 inhibition and the reciprocal auto-activation of CaMKII. Thus, CaMKII can regulate its own activation by inhibiting the PKC/PP1 cascade. Inhibition of Src family kinases (SFK) caused significant inhibition of CaMKII and PP1 phosphorylation, suggesting that SFK activity results in PP1 inhibition and CaMKII activation. Activation of sperm PKA by 8Br-cAMP revealed an increase in phospho-CaMKII, which was inhibited by PKA inhibitor. Tyrosine phosphorylation of PI3K was stimulated by 8Br-cAMP and by PKC or PP1 inhibition and was abrogated by CaMKII inhibition. Furthermore, phosphorylation/activation of the tyrosine kinase Pyk2 was enhanced by PP1 inhibition, and this activation is blocked by CaMKII inhibition. Thus, PKA activates Src, which inhibits PP1, leading to CaMKII and Pyk2 activation, resulting in PI3K tyrosine phosphorylation/activation.
Collapse
|
6
|
ET-1-induced growth promoting responses involving ERK1/2 and PKB signaling and Egr-1 expression are mediated by Ca2+/CaM-dependent protein kinase-II in vascular smooth muscle cells. Cell Calcium 2013; 54:428-35. [DOI: 10.1016/j.ceca.2013.10.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 10/04/2013] [Accepted: 10/06/2013] [Indexed: 11/22/2022]
|
7
|
Abstract
At least 468 individual genes have been manipulated by molecular methods to study their effects on the initiation, promotion, and progression of atherosclerosis. Most clinicians and many investigators, even in related disciplines, find many of these genes and the related pathways entirely foreign. Medical schools generally do not attempt to incorporate the relevant molecular biology into their curriculum. A number of key signaling pathways are highly relevant to atherogenesis and are presented to provide a context for the gene manipulations summarized herein. The pathways include the following: the insulin receptor (and other receptor tyrosine kinases); Ras and MAPK activation; TNF-α and related family members leading to activation of NF-κB; effects of reactive oxygen species (ROS) on signaling; endothelial adaptations to flow including G protein-coupled receptor (GPCR) and integrin-related signaling; activation of endothelial and other cells by modified lipoproteins; purinergic signaling; control of leukocyte adhesion to endothelium, migration, and further activation; foam cell formation; and macrophage and vascular smooth muscle cell signaling related to proliferation, efferocytosis, and apoptosis. This review is intended primarily as an introduction to these key signaling pathways. They have become the focus of modern atherosclerosis research and will undoubtedly provide a rich resource for future innovation toward intervention and prevention of the number one cause of death in the modern world.
Collapse
Affiliation(s)
- Paul N Hopkins
- Cardiovascular Genetics, Department of Internal Medicine, University of Utah, Salt Lake City, Utah, USA.
| |
Collapse
|
8
|
Chan KH, Chen YH, Zhang Y, Wong YH, Dun NJ. Angiotensin-[1-12] interacts with angiotensin type I receptors. Neuropharmacology 2013; 81:267-73. [PMID: 23823979 DOI: 10.1016/j.neuropharm.2013.06.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 06/05/2013] [Accepted: 06/19/2013] [Indexed: 11/26/2022]
Abstract
Angiotensin-(1-12) [Ang-(1-12)], a newer member of angiotensin peptides, is proposed to be converted enzymatically to angiotensin I (Ang I) and to angiotensin II (Ang II); the latter being the bioactive peptide. We studied the Ang-(1-12) and Ang II responses in COS-7 cells or CHO cells transfected with 5 μg AT1R by monitoring [Ca(2+)]i using the Fluo-4. Ang II (1 pM-1 μM) and Ang-(1-12) (5 pM-5 μM) increased [Ca(2+)]i with an EC50 of 0.19 nM and 24 nM in COS-7 cells; and 0.65 nM and 28.7 nM in CHO cells. The AT1R antagonist losartan (1 nM-10 μM) suppressed [Ca(2+)]i induced by Ang-(1-12) and Ang II. In CHO cells transfected with 5 μg AT2R, Ang II (1 pM-1 μM) increased [Ca(2+)]i, with an EC50 of 9.68 nM; whereas, Ang-(1-12) (5 pM-5 μM) failed to elicit a significant change in [Ca(2+)]i. In CHO cells transfected with AT1R, Ang-(1-12) stimulated ERK phosphorylation with a potency 300-fold less than that of Ang II. To evaluate the activity of Ang-(1-12) on native AT1R, whole cell patch recordings were made from neurons in the rat hypothalamic slices. Ang II or Ang-(1-12) ejected by pressure from a micropipette elicited a membrane depolarization; the latter was blocked by losartan (10 μM), and not affected by the AT2R antagonist PD123319 (10 μM), nor by the angiotensin converting enzyme inhibitor captopril (10 μM). Our result shows that Ang-(1-12) may produce its biological activity by acting directly on AT1R, albeit at a concentration higher than that of Ang II.
Collapse
Affiliation(s)
- King H Chan
- Division of Life Science and Biotechnology Research Institute, Clear Water Bay, Kowloon, Hong Kong
| | - Yi H Chen
- Graduate Institute of Acupuncture Science, China Medical University, Taichung, Taiwan
| | - Ying Zhang
- Department of Pharmacology, Temple University School of Medicine, 3420 N. Broad Street, Philadelphia, PA 19140, USA
| | - Yung H Wong
- Division of Life Science and Biotechnology Research Institute, Clear Water Bay, Kowloon, Hong Kong; State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Nae J Dun
- Department of Pharmacology, Temple University School of Medicine, 3420 N. Broad Street, Philadelphia, PA 19140, USA.
| |
Collapse
|
9
|
The p90 ribosomal S6 kinase (RSK) is a mediator of smooth muscle contractility. PLoS One 2013; 8:e58703. [PMID: 23516539 PMCID: PMC3596281 DOI: 10.1371/journal.pone.0058703] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Accepted: 02/05/2013] [Indexed: 11/19/2022] Open
Abstract
In the canonical model of smooth muscle (SM) contraction, the contractile force is generated by phosphorylation of the myosin regulatory light chain (RLC20) by the myosin light chain kinase (MLCK). Moreover, phosphorylation of the myosin targeting subunit (MYPT1) of the RLC20 phosphatase (MLCP) by the RhoA-dependent ROCK kinase, inhibits the phosphatase activity and consequently inhibits dephosphorylation of RLC20 with concomitant increase in contractile force, at constant intracellular [Ca2+]. This pathway is referred to as Ca2+-sensitization. There is, however, emerging evidence suggesting that additional Ser/Thr kinases may contribute to the regulatory pathways in SM. Here, we report data implicating the p90 ribosomal S6 kinase (RSK) in SM contractility. During both Ca2+- and agonist (U46619) induced SM contraction, RSK inhibition by the highly selective compound BI-D1870 (which has no effect on MLCK or ROCK) resulted in significant suppression of contractile force. Furthermore, phosphorylation levels of RLC20 and MYPT1 were both significantly decreased. Experiments involving the irreversible MLCP inhibitor microcystin-LR, in the absence of Ca2+, revealed that the decrease in phosphorylation levels of RLC20 upon RSK inhibition are not due solely to the increase in the phosphatase activity, but reflect direct or indirect phosphorylation of RLC20 by RSK. Finally, we show that agonist (U46619) stimulation of SM leads to activation of extracellular signal-regulated kinases ERK1/2 and PDK1, consistent with a canonical activation cascade for RSK. Thus, we demonstrate a novel and important physiological function of the p90 ribosomal S6 kinase, which to date has been typically associated with the regulation of gene expression.
Collapse
|
10
|
Barrett A, Pellet-Many C, Zachary IC, Evans IM, Frankel P. p130Cas: a key signalling node in health and disease. Cell Signal 2012; 25:766-77. [PMID: 23277200 DOI: 10.1016/j.cellsig.2012.12.019] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Accepted: 12/21/2012] [Indexed: 01/08/2023]
Abstract
p130Cas/breast cancer anti-oestrogen resistance 1 (BCAR1) is a member of the Cas (Crk-associated substrate) family of adaptor proteins, which have emerged as key signalling nodes capable of interactions with multiple proteins, with important regulatory roles in normal and pathological cell function. The Cas family of proteins is characterised by the presence of multiple conserved motifs for protein-protein interactions, and by extensive tyrosine and serine phosphorylations. Recent studies show that p130Cas contributes to migration, cell cycle control and apoptosis. p130Cas is essential during early embryogenesis, with a critical role in cardiovascular development. Furthermore, p130Cas has been reported to be involved in the development and progression of several human cancers. p130Cas is able to perform roles in multiple processes due to its capacity to regulate a diverse array of signalling pathways, transducing signals from growth factor receptor tyrosine kinases, non-receptor tyrosine kinases, and integrins. In this review we summarise the current understanding of the structure, function, and regulation of p130Cas, and discuss the importance of p130Cas in both physiological and pathophysiological settings, with a focus on the cardiovascular system and cancer.
Collapse
Affiliation(s)
- Angela Barrett
- Centre for Cardiovascular Biology and Medicine, Division of Medicine, University College London, London WC1E 6JJ, United Kingdom.
| | | | | | | | | |
Collapse
|
11
|
Giachini FRC, Carneiro FS, Lima VV, Carneiro ZN, Carvalho MHC, Fortes ZB, Webb RC, Tostes RC. Pyk2 mediates increased adrenergic contractile responses in arteries from DOCA-salt mice - VASOACTIVE PEPTIDE SYMPOSIUM. ACTA ACUST UNITED AC 2012; 2:431-8. [PMID: 19884968 DOI: 10.1016/j.jash.2008.05.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
BACKGROUND The calcium-dependent proline-rich tyrosine kinase (Pyk2), a nonreceptor protein activated by tyrosine phosphorylation, links G protein-coupled receptors to vascular responses. We tested the hypothesis that enhanced vascular reactivity in DOCA-salt hypertensive mice are due to increased activation of Pyk2. METHODS AND RESULTS Aorta and small mesenteric arteries from DOCA-salt and uninephrectomized (UNI) male C57Bl/6 mice were used. Systolic blood pressure (mmHg) was higher in DOCA (126+/-3) vs. UNI (100+/-4) mice. Vascular responses to phenylephrine (1nM to 100muM) were greater both in aorta and small mesenteric arteries from DOCA-salt than UNI, but treatment with Tyrphostin A-9 (0.1muM, Pyk2 inhibitor) abolished the difference among the groups. Pyk2 levels, as well as phospho-Pyk2(Tyr402), paxillin and phospho-paxillin(Tyr118) were increased in DOCA-salt aorta. Incubation of vessels with Tyrphostin A-9 restored phosphorylation of Pyk2 and paxillin. CONCLUSION Increased activation of Pyk2 contributes to increased vascular contractile-responses in DOCA-salt mice.
Collapse
|
12
|
Fisher KD, Codina J, Petrovic S, DuBose TD. Pyk2 regulates H+-ATPase-mediated proton secretion in the outer medullary collecting duct via an ERK1/2 signaling pathway. Am J Physiol Renal Physiol 2012; 303:F1353-62. [PMID: 22811489 DOI: 10.1152/ajprenal.00008.2012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Acid-secreting intercalated cells respond to changes in systemic pH through regulation of apical H(+) transporters. Little is known about the mechanism by which these cells sense changes in extracellular pH (pH(o)). Pyk2 is a nonreceptor tyrosine kinase activated by autophosphorylation at Tyr402 by cell-specific stimuli, including decreased pH, and is involved in the regulation of MAPK signaling pathways and transporter activity. We examined whether the Pyk2 and MAPK signaling pathway mediates the response of transport proteins to decreased pH in outer medullary collecting duct cells. Immunoblot analysis of phosphorylated Pyk2 (Tyr402), ERK1/2 (Thr202/Tyr204), and p38 (Thr180/Tyr182) was used to assay protein activation. To examine specificity of kinase activation and its effects, we used Pyk2 small interfering RNA to knockdown Pyk2 expression levels, the Src kinase inhibitor 4-amino-5-(4-methylphenyl)-7-(t-butyl)pyrazolo[3,4-d]-pyrimidine (PP 1) to inhibit Pyk2 phosphorylation, and the MEK inhibitor U0126 to inhibit ERK1/2 phosphorylation. The pH-sensitive fluorescent probe 2'-7'-bis(carboxyethyl)-5(6)-carboxyfluorescein-acetoxymethyl ester (BCECF-AM) was used to assay H(+) transporter activity. The activity of H(+) transporters was measured as the rate of intracellular pH (pH(i)) recovery after an NH(4)Cl prepulse. We show that Pyk2 is endogenously expressed and activated by acid pH in mouse-derived outer medullary collecting duct (mOMCD1) cells. Incubation of mOMCD1 cells in acid media [extracellular pH (pH(o)) 6.7] increased the phosphorylation of Pyk2, ERK1/2, and p38. Reduction in pH(i) induced by an NH(4)Cl prepulse also increased the phosphorylation of Pyk2, ERK1/2, and p38. Consistent with our previous studies, we found that mOMCD1 cells exhibit H(+)-ATPase and H(+),K(+)-ATPase activity. Pyk2 inhibition by Pyk2 siRNA and PP 1 prevented Pyk2 phosphorylation as well as H(+)-ATPase-mediated recovery in mOMCD1 cells. In addition, ERK1/2 inhibition by U0126 prevented acid-induced ERK1/2 phosphorylation and H(+)-ATPase-mediated pH(i) recovery but not phosphorylation of p38. We conclude that Pyk2 and ERK1/2 are required for increasing H(+)-ATPase, but not H(+),K(+)-ATPase, activity at decreased pH(i) in mOMCD1 cells.
Collapse
Affiliation(s)
- Kimberly D Fisher
- Sections on Nephrology and Molecular Medicine, Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, USA
| | | | | | | |
Collapse
|
13
|
The metabotropic glutamate receptor activates the lipid kinase PI3K in Drosophila motor neurons through the calcium/calmodulin-dependent protein kinase II and the nonreceptor tyrosine protein kinase DFak. Genetics 2011; 188:601-13. [PMID: 21515581 DOI: 10.1534/genetics.111.128561] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Ligand activation of the metabotropic glutamate receptor (mGluR) activates the lipid kinase PI3K in both the mammalian central nervous system and Drosophila motor nerve terminal. In several subregions of the mammalian brain, mGluR-mediated PI3K activation is essential for a form of synaptic plasticity termed long-term depression (LTD), which is implicated in neurological diseases such as fragile X and autism. In Drosophila larval motor neurons, ligand activation of DmGluRA, the sole Drosophila mGluR, similarly mediates a PI3K-dependent downregulation of neuronal activity. The mechanism by which mGluR activates PI3K remains incompletely understood in either mammals or Drosophila. Here we identify CaMKII and the nonreceptor tyrosine kinase DFak as critical intermediates in the DmGluRA-dependent activation of PI3K at Drosophila motor nerve terminals. We find that transgene-induced CaMKII inhibition or the DFak(CG1) null mutation each block the ability of glutamate application to activate PI3K in larval motor nerve terminals, whereas transgene-induced CaMKII activation increases PI3K activity in motor nerve terminals in a DFak-dependent manner, even in the absence of glutamate application. We also find that CaMKII activation induces other PI3K-dependent effects, such as increased motor axon diameter and increased synapse number at the larval neuromuscular junction. CaMKII, but not PI3K, requires DFak activity for these increases. We conclude that the activation of PI3K by DmGluRA is mediated by CaMKII and DFak.
Collapse
|
14
|
Perez J, Torres RA, Rocic P, Cismowski MJ, Weber DS, Darley-Usmar VM, Lucchesi PA. PYK2 signaling is required for PDGF-dependent vascular smooth muscle cell proliferation. Am J Physiol Cell Physiol 2011; 301:C242-51. [PMID: 21451101 DOI: 10.1152/ajpcell.00315.2010] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Aberrant vascular smooth muscle cell (VSMC) growth is associated with many vascular diseases including atherosclerosis, hypertension, and restenosis. Platelet-derived growth factor-BB (PDGF) induces VSMC proliferation through control of cell cycle progression and protein and DNA synthesis. Multiple signaling cascades control VSMC growth, including members of the mitogen-activated protein kinase (MAPK) family as well as phosphatidylinositol 3-kinase (PI3K) and its downstream effector AKT/protein kinase B (PKB). Little is known about how these signals are integrated by mitogens and whether there are common receptor-proximal signaling control points that synchronize the execution of physiological growth functions. The nonreceptor proline-rich tyrosine kinase 2 (PYK2) is activated by a variety of growth factors and G protein receptor agonists in VSMC and lies upstream of both PI3K and MAPK cascades. The present study investigated the role of PYK2 in PDGF signaling in cultured rat aortic VSMC. PYK2 downregulation attenuated PDGF-dependent protein and DNA synthesis, which correlated with inhibition of AKT and extracellular signal-regulated kinases 1 and 2 (ERK1/2) but not p38 MAPK activation. Inhibition of PDGF-dependent protein kinase B (AKT) and ERK1/2 signaling by inhibitors of upstream kinases PI3K and MEK, respectively, as well as downregulation of PYK2 resulted in modulation of the G(1)/S phase of the cell cycle through inhibition of retinoblastoma protein (Rb) phosphorylation and cyclin D(1) expression, as well as p27(Kip) upregulation. Cell division kinase 2 (cdc2) phosphorylation at G(2)/M was also contingent on PDGF-dependent PI3K-AKT and ERK1/2 signaling. These data suggest that PYK2 is an important upstream mediator in PDGF-dependent signaling cascades that regulate VSMC proliferation.
Collapse
Affiliation(s)
- Jessica Perez
- Department of Cell Biology, University of Alabama at Birmingham, Alabama, USA
| | | | | | | | | | | | | |
Collapse
|
15
|
Shen X, Xi G, Radhakrishnan Y, Clemmons DR. Recruitment of Pyk2 to SHPS-1 signaling complex is required for IGF-I-dependent mitogenic signaling in vascular smooth muscle cells. Cell Mol Life Sci 2010; 67:3893-903. [PMID: 20521079 PMCID: PMC11115943 DOI: 10.1007/s00018-010-0411-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2010] [Revised: 04/30/2010] [Accepted: 05/17/2010] [Indexed: 10/25/2022]
Abstract
In vascular smooth muscle cells, IGF-I stimulates SHPS-1/SHP2/Src complex formation which is required for IGF-I-stimulated cell proliferation. Using SHP2/Src silencing and a Pyk2/Y402F mutant, we showed that Pyk2 was also recruited to the SHPS-1 complex. Pyk2 recruitment to SHPS-1 is mediated via the interaction of Pyk2 Tyr402 and the Src in response to IGF-I. Following Src/Pyk2 association, Src phosphorylates Pyk2 on Tyr881 providing a binding site for Grb2. Cells expressing Pyk2/Y881F showed decreased Grb2 recruitment to SHPS-1 and impaired Shc/Grb2 association. This change led to reduced Erk1/2 (MAP kinase) activation and cell proliferation in response to IGF-I. Our results show that, following its recruitment to the SHPS-1 signaling complex, Pyk2 localizes Grb2 in close proximity to Shc thereby facilitating Shc/Grb2 association which leads to Erk1/2 activation in response to IGF-I. Thus, Pyk2 recruitment to SHPS-1 plays an important role in regulating the IGF-I-stimulated mitogenic response.
Collapse
Affiliation(s)
- Xinchun Shen
- Department of Medicine, School of Medicine, University of North Carolina, Chapel Hill, NC 27599 USA
| | - Gang Xi
- Department of Medicine, School of Medicine, University of North Carolina, Chapel Hill, NC 27599 USA
| | - Yashwanth Radhakrishnan
- Department of Medicine, School of Medicine, University of North Carolina, Chapel Hill, NC 27599 USA
| | - David R. Clemmons
- Department of Medicine, School of Medicine, University of North Carolina, Chapel Hill, NC 27599 USA
- Division of Endocrinology, University of North Carolina at Chapel Hill, CB# 7170, 8024 Burnett-Womack, Chapel Hill, NC 27599-7170 USA
| |
Collapse
|
16
|
Castillo-Hernández MC, Martinez-Godinez MA, Guevara-Balcazar G, Miliar-Garcia A, Mancilla J, Lopez-Mayorga RM, Castillo-Henkel EF, Castillo-Henkel C. Extraendothelial and constitutive COX-2 expression is involved in the contractile effect of angiotensin II in the rat aorta. ACTA ACUST UNITED AC 2010; 30:205-11. [PMID: 20626388 DOI: 10.1111/j.1474-8673.2010.00457.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
1 The role of the extraendothelial and constitutive isoforms of cyclo-oxygenase-2 (COX-2) in the contractile effect of angiotensin II (Ang II) was investigated using thoracic and abdominal aortic rings without endothelium from young Wistar rats. 2 Ang II elicited similar contractions in both aortic segments, and the effect was inhibited by pretreatment with NS398 (a selective COX-2 inhibitor) but not SC-560 [selective cyclo-oxygenase-1 (COX-1) inhibitor]. 3 COX-2 mRNA was expressed under basal conditions in both aortic segments. Additionally, Ang II increased COX-2 mRNA expression in the abdominal but not the thoracic segment, while cycloheximide (a protein synthesis inhibitor) did not affect the contractile response to Ang II in either of the two segments; this suggests that the effect is not associated with de novo COX-2 synthesis. 4 In conclusion, the basal amount of COX-2 found in aortic smooth muscle cells is sufficient to explain the production of the prostanoids related to the contractile effect of Ang II. The production of these prostanoids, which are derived from constitutive COX-2, occurs independently of the endothelium vascular system.
Collapse
Affiliation(s)
- M C Castillo-Hernández
- Departamento de Posgrado e Investigacion, Escuela Superior de Medicina IPN, Plan de San Lius y Diaz Miron s/n, Col. Casco Sto. Tomas, Del. Miguel Hidalgo, CP. 11340, Mexico DF, Mexico
| | | | | | | | | | | | | | | |
Collapse
|
17
|
Zhang S, Guo D, Luo W, Zhang Q, Zhang Y, Li C, Lu Y, Cui Z, Qiu X. TrkB is highly expressed in NSCLC and mediates BDNF-induced the activation of Pyk2 signaling and the invasion of A549 cells. BMC Cancer 2010; 10:43. [PMID: 20156366 PMCID: PMC2830183 DOI: 10.1186/1471-2407-10-43] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2009] [Accepted: 02/16/2010] [Indexed: 11/12/2022] Open
Abstract
Background Aberrant regulation in the invasion of cancer cells is closely associated with their metastatic potentials. TrkB functions as a receptor tyrosine kinase and is considered to facilitate tumor metastasis. Pyk2 is a non-receptor tyrosine kinase and integrates signals in cell invasion. However, little is known about the expression of TrkB in NSCLC and whether Pyk2 is involved in TrkB-mediated invasion of A549 cells. Methods The expression of TrkB was investigated in NSCLC by immunohistochemical staining. Both HBE and A549 cells were treated with BDNF. The expression of TrkB, Pyk2 and ERK phosphorylations were assessed by western blot. Besides, A549 cells were transfected with TrkB-siRNA or Pyk2-siRNA, or treated with ERK inhibitor where indicated. Transwell assay was performed to evaluate cell invasion. Results 40 cases (66.7%) of NSCLC were found higher expression of TrkB and patients with more TrkB expression had significant metastatic lymph nodes (p = 0.028). BDNF facilitated the invasion of A549 cells and the activations of Pyk2 in Tyr402 and ERK. However, the effects of BDNF were not observed in HBE cells with lower expression of TrkB. In addition, the increased Pyk2 and ERK activities induced by BDNF were significantly inhibited by blocking TrkB expression, so was the invasion of A549 cells. Knockdown studies revealed the essential role of Pyk2 for BDNF-induced cell invasion, since the invasion of A549 cells was abolished by Pyk2-siRNA. The application of ERK inhibitor also showed the suppressed ERK phosphorylation and cell invasion. Conclusion These data indicated that higher expression of TrkB in NSCLC was closely correlated with lymph node metastasis, and BDNF probably via TrkB/Pyk2/ERK promoted the invasion of A549 cells.
Collapse
Affiliation(s)
- Siyang Zhang
- Center of Laboratory Technology and Experimental Medicine, China Medical University, Shenyang, China.
| | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Bouallegue A, Pandey NR, Srivastava AK. CaMKII knockdown attenuates H2O2-induced phosphorylation of ERK1/2, PKB/Akt, and IGF-1R in vascular smooth muscle cells. Free Radic Biol Med 2009; 47:858-66. [PMID: 19545622 DOI: 10.1016/j.freeradbiomed.2009.06.022] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2008] [Revised: 05/19/2009] [Accepted: 06/18/2009] [Indexed: 12/23/2022]
Abstract
We have shown earlier a requirement for Ca(2+) and calmodulin (CaM) in the H(2)O(2)-induced activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) and protein kinase B (PKB), key mediators of growth-promoting, proliferative, and hypertrophic responses in vascular smooth muscle cells (VSMC). Because the effect of CaM is mediated through CaM-dependent protein kinase II (CaMKII), we have investigated here the potential role of CaMKII in H(2)O(2)-induced ERK1/2 and PKB phosphorylation by using pharmacological inhibitors of CaM and CaMKII, a CaMKII inhibitor peptide, and siRNA knockdown strategies for CaMKII alpha. Calmidazolium and W-7, antagonists of CaM, as well as KN-93, a specific inhibitor of CaMKII, attenuated H(2)O(2)-induced responses of ERK1/2 and PKB phosphorylation in a dose-dependent fashion. Similar to H(2)O(2), calmidazolium and KN-93 also exhibited an inhibitory effect on glucose/glucose oxidase-induced phosphorylation of ERK1/2 and PKB in these cells. Transfection of VSMC with CaMKII autoinhibitory peptide corresponding to the autoinhibitory domain (aa 281-309) of CaMKII and with siRNA of CaMKII alpha attenuated the H(2)O(2)-induced phosphorylation of ERK1/2 and PKB. In addition, calmidazolium and KN-93 blocked H(2)O(2)-induced Pyk2 and insulin-like growth factor-1 receptor (IGF-1R) phosphorylation. Moreover, treatment of VSMC with CaMKII alpha siRNA abolished the H(2)O(2)-induced IGF-1R phosphorylation. H(2)O(2) treatment also induced Thr(286) phosphorylation of CaMKII, which was inhibited by both calmidazolium and KN-93. These results demonstrate that CaMKII plays a critical upstream role in mediating the effects of H(2)O(2) on ERK1/2, PKB, and IGF-1R phosphorylation.
Collapse
Affiliation(s)
- Ali Bouallegue
- Laboratory of Cell Signaling, Montreal Diabetes Research Centre, Centre de Recherche, Centre Hospitalier de l'Université de Montréal, Technopole Angus Campus, Montreal, Canada
| | | | | |
Collapse
|
19
|
Chen S, Wang R, Li QF, Tang DD. Abl knockout differentially affects p130 Crk-associated substrate, vinculin, and paxillin in blood vessels of mice. Am J Physiol Heart Circ Physiol 2009; 297:H533-9. [PMID: 19542491 DOI: 10.1152/ajpheart.00237.2009] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Actin polymerization has recently emerged as an important cellular process that regulates smooth muscle contraction. Abelson tyrosine kinase (Abl) has been implicated in the regulation of actin dynamics and force development in vascular smooth muscle. In the present study, the systolic blood pressure was lower in Abl(-/-) knockout mice compared with wild-type mice. The knockout of Abl diminished the tyrosine phosphorylation of p130 Crk-associated substrate (CAS, an adapter protein associated with smooth muscle contraction) in resistance arteries upon stimulation with phenylephrine or angiotensin II. The agonist-elicited enhancement of F-actin-to-G-actin ratios in arteries assessed by fluorescent microscopy was also reduced in Abl(-/-) mice. It has been known that vinculin is a structural protein that links actin filaments to extracellular matrix via transmembrane integrins, whereas paxillin is a signaling protein associated with focal contacts mediating actin cytoskeleton remodeling. The expression of vinculin and paxillin at protein and messenger levels was lower in arterial vessels from Abl knockout mice. However, the agonist-induced increase in myosin phosphorylation was not attenuated in arteries from Abl knockout mice. These results indicate that Abl differentially regulates Crk-associated substrate, vinculin, and paxillin in arterial vessels. The Abl-regulated cellular process and blood pressure are independent of myosin activation in vascular smooth muscle.
Collapse
Affiliation(s)
- Shu Chen
- The Center for Cardiovascular Sciences, Albany Medical College, Albany, New York 12208, USA
| | | | | | | |
Collapse
|
20
|
Menashi EB, Loftus JC. Differential effects of Pyk2 and FAK on the hypertrophic response of cardiac myocytes. Cell Tissue Res 2009; 337:243-55. [PMID: 19484266 DOI: 10.1007/s00441-009-0807-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2008] [Accepted: 04/08/2009] [Indexed: 11/26/2022]
Abstract
The related cytoplasmic non-receptor tyrosine kinases Pyk2 (proline-rich tyrosine kinase 2) and FAK (focal adhesion kinase) have been implicated in phenylephrine-induced G-protein-coupled receptor-mediated signaling mechanisms leading to cardiomyocyte hypertrophy. We report that, in phenylephrine-stimulated neonatal rat ventricular myocytes (NRVM), Pyk2 augments expression of the hypertrophic marker atrial natriuretic factor (ANF) but reduces cytoskeletal organization and cell spreading. In contrast, FAK attenuates ANF production but does not alter cytoskeletal organization and cell spreading. Pyk2 and FAK exhibit differential localization in both unstimulated and phenylephrine-stimulated myocytes. Pyk2 catalytic activity is required for Pyk2 to augment ANF secretion but is not necessary to reduce cell spreading. Pyk2 autophosphorylation is required but not sufficient for Pyk2 to augment ANF secretion. Expression of the Pyk2 FERM domain as an autonomous fragment inhibits phenylephrine-mediated ANF secretion and reduces cell spreading. In addition, expression of the Pyk2 FERM domain inhibits the ability of Pyk2 to augment ANF secretion; this is correlated with reduced Pyk2 autophosphorylation. These data indicate that Pyk2 and FAK have different roles and occupy different positions in signaling pathways leading to the development of cardiomyocyte hypertrophy.
Collapse
Affiliation(s)
- Emmanuel B Menashi
- Department of Biochemistry and Molecular Biology, Mayo Clinic Arizona, Scottsdale, 85259, USA
| | | |
Collapse
|
21
|
Frey RS, Ushio-Fukai M, Malik AB. NADPH oxidase-dependent signaling in endothelial cells: role in physiology and pathophysiology. Antioxid Redox Signal 2009; 11:791-810. [PMID: 18783313 PMCID: PMC2790033 DOI: 10.1089/ars.2008.2220] [Citation(s) in RCA: 314] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Reactive oxygen species (ROS) including superoxide (O(2)(.-)) and hydrogen peroxide (H(2)O(2)) are produced endogenously in response to cytokines, growth factors; G-protein coupled receptors, and shear stress in endothelial cells (ECs). ROS function as signaling molecules to mediate various biological responses such as gene expression, cell proliferation, migration, angiogenesis, apoptosis, and senescence in ECs. Signal transduction activated by ROS, "oxidant signaling," has received intense investigation. Excess amount of ROS contribute to various pathophysiologies, including endothelial dysfunction, atherosclerosis, hypertension, diabetes, and acute respiratory distress syndrome (ARDS). The major source of ROS in EC is a NADPH oxidase. The prototype phagaocytic NADPH oxidase is composed of membrane-bound gp91phox and p22hox, as well as cytosolic subunits such as p47(phox), p67(phox) and small GTPase Rac. In ECs, in addition to all the components of phagocytic NADPH oxidases, homologues of gp91(phox) (Nox2) including Nox1, Nox4, and Nox5 are expressed. The aim of this review is to provide an overview of the emerging area of ROS derived from NADPH oxidase and oxidant signaling in ECs linked to physiological and pathophysiological functions. Understanding these mechanisms may provide insight into the NADPH oxidase and oxidant signaling components as potential therapeutic targets.
Collapse
Affiliation(s)
- Randall S Frey
- Department of Pharmacology, Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, Illinois 60612, USA.
| | | | | |
Collapse
|
22
|
Abstract
Vascular smooth muscle is a key effector in the wall of blood vessels during the pathogenesis of hypertension. Various factors directly elicit smooth muscle cell contraction, migration, growth, and hypertrophy, which lead to the progression of hypertension. Crk-associated substrate (CAS), the first discovered member of the adapter protein CAS family, has recently emerged as a critical cellular component that regulates smooth muscle functions. In this review, the molecular structure and protein interactions of the CAS family members are summarized. Evidence for the role of CAS in the regulation of vascular smooth muscle contractility, cell migration, hypertrophy, and growth is presented. Regulation of CAS by novel tyrosine kinases/phosphatases and unique downstream signaling partners of CAS are also discussed. These new findings establish the important role for CAS in regulating vascular smooth muscle functions. The CAS-associated processes may be new biological targets for the development of new treatment of cardiovascular diseases such as hypertension.
Collapse
Affiliation(s)
- Dale D Tang
- Center for Cardiovascular Sciences, Albany Medical College, Albany, New York 12208, USA.
| |
Collapse
|
23
|
LPS-induced MCP-1 expression in human microvascular endothelial cells is mediated by the tyrosine kinase, Pyk2 via the p38 MAPK/NF-kappaB-dependent pathway. Mol Immunol 2008; 46:962-8. [PMID: 18954908 DOI: 10.1016/j.molimm.2008.09.022] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2008] [Revised: 09/12/2008] [Accepted: 09/15/2008] [Indexed: 11/22/2022]
Abstract
Bacterial endotoxin (lipopolysaccharide or LPS) has potent pro-inflammatory properties and acts on many cell types including endothelial cells. Secretion of the CC chemokine, MCP-1 (CCL2) by LPS-activated endothelial cells contributes substantially to the pathogenesis of sepsis. However, the mechanism involved in LPS-induced MCP-1 production in endothelial cells is not well understood. Using human microvascular endothelial cells (HMVEC), we analyzed the involvement of the non-receptor tyrosine kinase, Pyk2, in LPS-mediated MCP-1 production. There was a marked activation of the non-receptor tyrosine kinase, Pyk2, in response to LPS. Inhibition of Pyk2 activity using a pharmacological inhibitor, Tyrphostin A9 significantly attenuated LPS-induced Pyk2 tyrosine phosphorylation, p38 MAP kinase (MAPK) activation, NF-kappaB activation, and MCP-1 expression. Furthermore, specific inactivation of Pyk2 activity by transducing microvascular endothelial cells with catalytically inactive Pyk2 mutant (AAV-Pyk2MT) or Pyk2-specific siRNA significantly blocked LPS-induced MCP-1 production. The supernatants of these LPS-stimulated cells with attenuated Pyk2 activity demonstrated decreased trans-endothelial monocyte migration in comparison to LPS-treated controls, thus confirming the inhibition of functional MCP-1 production. In summary, our data suggest a critical role for the Pyk2 mediated pathway involving p38 MAP kinase and NF-kappaB in LPS-induced MCP-1 production in human microvascular endothelial cells.
Collapse
|
24
|
Anand AR, Cucchiarini M, Terwilliger EF, Ganju RK. The tyrosine kinase Pyk2 mediates lipopolysaccharide-induced IL-8 expression in human endothelial cells. THE JOURNAL OF IMMUNOLOGY 2008; 180:5636-44. [PMID: 18390748 DOI: 10.4049/jimmunol.180.8.5636] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Secretion of proinflammatory cytokines by LPS activated endothelial cells contributes substantially to the pathogenesis of sepsis. However, the mechanism involved in this process is not well understood. In the present study, we determined the role of a nonreceptor proline-rich tyrosine kinase, Pyk2, in LPS-induced IL-8 (CXCL8) production in endothelial cells. First, we observed a marked activation of Pyk2 in response to LPS. Furthermore, inhibition of Pyk2 activity in these cells by transduction with the catalytically inactive Pyk2 mutant, transfection with Pyk2-specific small interfering RNA, or treatment with Tyrphostin A9 significantly blocked LPS-induced IL-8 production. The supernatants of LPS-stimulated cells exhibiting attenuated Pyk2 activity blocked transendothelial neutrophil migration in comparison to the supernatants of LPS-treated controls, thus confirming the inhibition of functional IL-8 production. Investigations into the molecular mechanism of this pathway revealed that LPS activates Pyk2 leading to IL-8 production through the TLR4. In addition, we identified the p38 MAPK pathway to be a critical step downstream of Pyk2 during LPS-induced IL-8 production. Taken together, these results demonstrate a novel role for Pyk2 in LPS-induced IL-8 production in endothelial cells.
Collapse
Affiliation(s)
- Appakkudal R Anand
- Department of Pathology, Ohio State University Medical Center, Columbus, OH 43210, USA
| | | | | | | |
Collapse
|
25
|
Zhang S, Qiu X, Gu Y, Wang E. Up-regulation of proline-rich tyrosine kinase 2 in non-small cell lung cancer. Lung Cancer 2008; 62:295-301. [PMID: 18571765 DOI: 10.1016/j.lungcan.2008.05.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2007] [Revised: 04/06/2008] [Accepted: 05/05/2008] [Indexed: 11/16/2022]
Abstract
Proline-rich tyrosine kinase 2 (PYK2) is a non-receptor tyrosine kinase, plays different roles in intracellular signaling pathways, that regulates a number of biological processes, such as cell proliferation, differentiation, adhesion and migration, which have been shown to correlate with tumor development and aggression. However, the involvement of PYK2 in human non-small cell lung cancer (NSCLC) has not yet been determined. In the present study, 90 patients with NSCLC (represented by adenocarcinoma and squamous cell carcinoma) were included retrospectively. NSCLC tissues were detected for the expression of PYK2 by immunohistochemistry. Correlation between the expression of PYK2 with the clinicopathological characteristics was analyzed. There were 64% (58 out of 90) of NSCLC patients with higher level of PYK2. Higher expression of PYK2 was significantly correlated with lymph node metastasis (node positive versus node negative, p=0.007). Patients with higher expression of PYK2 had advanced stage of NSCLCs (I+II versus III+IV, p=0.012). Protein level of PYK2 was also examined in 30 of these tumorous samples and matched non-tumorous counterparts by western blotting. PYK2 was apparently up-regulated in NSCLC tissues (tumor versus non-tumor, p=0.000). In the cell studies, extensive expression and activation of PYK2 were both found in higher metastatic BE1 cells. The activity of ERK1/2 in BE1 cells appeared extremely high as well. In conclusion, our results demonstrated that PYK2 is up-regulated in NSCLCs, and the higher expression and activation of PYK2 may play a role in modulating the activity of ERK1/2, and lead to the progression of NSCLC.
Collapse
Affiliation(s)
- Siyang Zhang
- Department of Pathology, College of Basic Medical Sciences, China Medical University, and Department of Pathology, the First Affiliated Hospital of China Medical University, Shenyang, China
| | | | | | | |
Collapse
|
26
|
Ushio-Fukai M, Frey RS, Fukai T, Malik AB. Chapter 8 Reactive Oxygen Species and Endothelial Permeability. CURRENT TOPICS IN MEMBRANES 2008. [DOI: 10.1016/s1063-5823(08)00208-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
27
|
Clark MA, Gonzalez N. Src and Pyk2 mediate angiotensin II effects in cultured rat astrocytes. ACTA ACUST UNITED AC 2007; 143:47-55. [PMID: 17391778 DOI: 10.1016/j.regpep.2007.02.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2006] [Revised: 02/15/2007] [Accepted: 02/18/2007] [Indexed: 12/01/2022]
Abstract
Angiotensin II (Ang II)-induced proliferation of rat astrocytes is mediated by multiple signaling pathways. In the present study, we investigated the role of non-receptor tyrosine kinases on Ang II-signaling and proliferation of astrocytes cultured from neonatal rat pups. Ang II stimulated astrocyte growth, ERK1/2 phosphorylation and the phosphorylation of Src and proline-rich tyrosine kinase-2 (Pyk2), in astrocytes obtained from brainstem and cerebellum. Pretreatment with 10 microM PP2, a selective Src inhibitor, inhibited Ang II stimulated ERK1/2 phosphorylation by 59% to 91% both in brainstem and cerebellum astrocytes. PP2 also inhibited Ang II induction of brainstem (76% inhibition) and cerebellar (64% inhibition) astrocyte growth. Similarly, pretreatment with 25 microM dantrolene, the Pyk2 inhibitor, attenuated ERK1/2 activity in brainstem (62% inhibition) and in cerebellum astrocytes (44% inhibition). Interestingly, inhibition of Pyk2 inhibited Ang II-induced Src activation suggesting that these two non-receptor tyrosine kinases may be acting in concert to mediate Ang II effects in astrocytes. In summary, we found that Ang II stimulates the non-receptor tyrosine kinases Src and Pyk2 which mediate Ang II-induced ERK1/2 activation leading to stimulation of astrocyte growth. In addition, these two tyrosine kinases may be interacting to regulate effects of the peptide in these cells.
Collapse
Affiliation(s)
- Michelle A Clark
- Department of Pharmaceutical and Administrative Sciences, College of Pharmacy, Nova Southeastern University, 3200 South University Drive, Fort Lauderdale, FL 33328, USA.
| | | |
Collapse
|
28
|
Roelle S, Grosse R, Buech T, Chubanov V, Gudermann T. Essential role of Pyk2 and Src kinase activation in neuropeptide-induced proliferation of small cell lung cancer cells. Oncogene 2007; 27:1737-48. [PMID: 17906699 DOI: 10.1038/sj.onc.1210819] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Neuropeptide hormones like bombesin/gastrin-releasing peptide, galanin or bradykinin, acting via auto and paracrine growth loops, represent the principal mitogens of small cell lung cancer (SCLC). These mitogenic neuropeptides activate G(q/11)-coupled receptors which stimulate phospholipase Cbeta activity, followed by rises of the intracellular calcium concentration ([Ca2+](i)) and activation of protein kinase C (PKC). We report here that proline-rich tyrosine kinase Pyk2 is highly expressed in SCLC cells and provides a functional link between neuropeptide-induced increases in [Ca2+](i) and tumor cell proliferation. Activation of Pyk2 and its association with Src kinases critically depends on the elevation of [Ca2+](i), but is independent of PKC. Src kinase activities are crucial for neuropeptide-mediated GTP-loading of Ras and activation of extracellular signal-regulated kinases in SCLC cells. Pyk2 and Src kinases essentially contribute to anchorage-independent proliferation of SCLC cells. Inhibition of either Pyk2 or Src kinases by lentiviral RNAi or pharmacological inhibition with PP2, respectively, attenuated basal and neuropeptide-elicited survival and proliferation of SCLC cells in liquid culture and in soft agar. Thus, neuropeptides stimulate anchorage-independent survival and proliferation of SCLC cells via pathways involving Pyk2 and Src kinases. Therefore, Ca2+-induced Pyk2/Src complex formation may be a rewarding molecular target for novel therapeutic strategies in SCLC cells.
Collapse
Affiliation(s)
- S Roelle
- 1Institut für Pharmakologie und Toxikologie, Philipps-Universität Marburg, Marburg, Germany
| | | | | | | | | |
Collapse
|
29
|
Montiel M, Quesada J, Jiménez E. Activation of calcium-dependent kinases and epidermal growth factor receptor regulate muscarinic acetylcholine receptor-mediated MAPK/ERK activation in thyroid epithelial cells. Cell Signal 2007; 19:2138-46. [PMID: 17643958 DOI: 10.1016/j.cellsig.2007.06.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2007] [Accepted: 06/15/2007] [Indexed: 10/23/2022]
Abstract
We previously showed that stimulation of muscarinic acetylcholine receptors (mAChR) by carbachol (Cch) caused a time- and dose-dependent increase of mitogen-activated protein kinase/extracellular signal-regulated kinases (MAPK/ERK) phosphorylation in thyroid epithelial cells. In this study, we demonstrated that mAChR stimulation also induced a time-dependent increase in the tyrosine phosphorylation of proline-rich tyrosine kinase 2 (Pyk2), which was prevented by pretreatment of thyroid epithelial cells with the specific Src-family tyrosine kinase inhibitor PP2. Besides, phosphorylation of Pyk2 was attenuated by chelation of extracellular Ca(2+) or inhibition of phospholipase C (PLC), and was evoked by thapsigargin, a specific microsomal Ca(2+)-ATPase inhibitor. Incorporation of Pyk2 antisense oligonucleotides in thyroid epithelial cells to down-regulated Pyk2 expression or pretreatment of cells with the Ca(2+)/calmodulin protein kinase II (CaM kinase II) inhibitor KN-62 significantly reduced Cch-induced MAPK/ERK phosphorylation. In addition, Cch-induced MAPK/ERK phosphorylation was partially inhibited by LY294002 and wortmannin, two selective inhibitors of phosphatidylinositol 3-kinase (PI3K), tyrphostin AG1478, a specific inhibitor of epidermal growth factor receptor (EGFR) kinase, and (-)-perillic acid, a post-translational inhibitor of small G-proteins isoprenylation. Taken together, our data suggest that Pyk2, CaM kinase II and Src-family tyrosine kinases are key molecules for the activation of MAPK/ERK cascade through the EGFR/Ras/Raf pathway in thyroid epithelial cells in response to mAChR stimulation.
Collapse
Affiliation(s)
- Mercedes Montiel
- Department of Biochemistry and Molecular Biology, University of Malaga, Boulevard Louis Pasteur 32, 29071 Malaga, Spain
| | | | | |
Collapse
|
30
|
Azar ZM, Mehdi MZ, Srivastava AK. Insulin-like growth factor type-1 receptor transactivation in vasoactive peptide and oxidant-induced signaling pathways in vascular smooth muscle cells. Can J Physiol Pharmacol 2007; 85:105-11. [PMID: 17487250 DOI: 10.1139/y06-101] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Transactivation of epidermal growth factor receptor (EGFR) is a well-documented mechanism by which vasoactive peptides and H2O2 elicit their cellular responses. However, a role for the insulin-like growth factor type-1 receptor (IGF-1R) transactivation in mediating the effects of angiotensin II (Ang II) and H2O2 in vascular smooth muscle cells from different artery types have also been recently recognized. By using a series of pharmacological inhibitors of various growth factor receptor tyrosine kinases and a direct analysis of the phosphorylation status of the beta-subunit of IGF-1R, a requirement of this growth factor receptor in Ang II and H2O2 response has been demonstrated. This review discusses some of the studies that highlight the importance of IGF-1R transactivation in mediating Ang II- and H2O2-induced mitogen-activated protein kinase and protein kinase B signaling pathways.
Collapse
MESH Headings
- Angiotensin II/metabolism
- Animals
- Arteries/metabolism
- Humans
- Hydrogen Peroxide/pharmacology
- Mitogen-Activated Protein Kinases/metabolism
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Oxidants/pharmacology
- Oxidative Stress/drug effects
- Phosphorylation
- Protein Kinase Inhibitors/pharmacology
- Proto-Oncogene Proteins c-akt/metabolism
- Reactive Oxygen Species/metabolism
- Receptor, IGF Type 1/antagonists & inhibitors
- Receptor, IGF Type 1/metabolism
- Receptors, G-Protein-Coupled/metabolism
- Signal Transduction/drug effects
- Vasoconstrictor Agents/metabolism
Collapse
Affiliation(s)
- Zeina M Azar
- Montreal Diabetes Research Centre, Centre hospitalier de l'Université de Montréal (CHUM)- Angus Campus and Department of Medicine, Université de Montréal, 2901, Rachel East, Montreal, QC H1W 4A4, Canada
| | | | | |
Collapse
|
31
|
Azar ZM, Mehdi MZ, Srivastava AK. Activation of insulin-like growth factor type-1 receptor is required for H2O2-induced PKB phosphorylation in vascular smooth muscle cells. Can J Physiol Pharmacol 2007; 84:777-86. [PMID: 16998541 DOI: 10.1139/y06-024] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Evidence accumulated in recent years has revealed a potential role for reactive oxygen species (ROS) in the pathophysiology of cardiovascular diseases. However, the precise mechanisms by which ROS contribute to the development of these diseases are not fully established. Previous work from our laboratory has indicated that exogenous hydrogen peroxide (H2O2) activates several signaling protein kinases, such as extracellular signal-regulated kinase 1 and 2 (ERK1/2) and protein kinase B (PKB) in A10 vascular smooth muscle cells (VSMC). However, the upstream elements responsible for this activation remain unclear. Although a role for epidermal growth factor receptor (EGFR) protein tyrosine kinase (PTK) in H2O2-induced ERK1/2 signaling has been suggested, the contribution of this PTK or other receptor or nonreceptor PTKs to PKB activation is not well defined in VSMC. In this study, we used pharmacological inhibitors to investigate the role of receptor and Src-family-PTKs in H2O2-induced PKB phosphorylation. AG1478, a specific inhibitor of EGFR, failed to attenuate the H2O2-induced increase in PKB Ser473 phosphorylation, whereas AG1024, an inhibitor of insulin-like growth factor type1 receptor (IGF-1R)-PTK, almost completely blocked this response. H2O2 treatment also enhanced tyrosine phosphorylation of the IGF-1Rbeta subunit, which was significantly inhibited by AG1024 pretreatment of cells. Furthermore, pharmacological inhibition of Src by PP2 (4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazole(3,4-d) pyrimidine) decreased PKB phosphorylation. Moreover, H2O2-induced PKB phosphorylation was associated with increased tyrosine phosphorylation of c-Src and Pyk2 in an AG1024- and PP2-inhibitable manner. In conclusion, these data provide evidence of the contribution of IGF-1R-PTK in initiating H2O2-evoked PKB phosphorylation in A10 VSMC, with an intermediary role for c-Src and Pyk2 in this process.
Collapse
Affiliation(s)
- Zeina M Azar
- Laboratory of Cell Signaling, Research Centre, Centre hospitalier de l'Université de Montréal (CHUM) - Hôtel-Dieu and Department of Medicine, Université de Montréal, 3850, St. Urbain Street, Rm. 7-135, Montreal, QC H2W 1T7, Canada
| | | | | |
Collapse
|
32
|
Strappazzon F, Torch S, Trioulier Y, Blot B, Sadoul R, Verna JM. Survival response-linked Pyk2 activation during potassium depletion-induced apoptosis of cerebellar granule neurons. Mol Cell Neurosci 2006; 34:355-65. [PMID: 17188509 DOI: 10.1016/j.mcn.2006.11.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2006] [Revised: 10/27/2006] [Accepted: 11/14/2006] [Indexed: 11/16/2022] Open
Abstract
Numerous extracellular stimuli trigger trans-autophosphorylation at Tyr402 of Pyk2, inducing its activation. Pyk2 is a key mediator of several signaling pathways and has been implicated in apoptosis induced by specific stress signals. We investigated whether Pyk2 participates in cerebellar granule neuron (CGN) apoptosis induced by the suppression of membrane depolarization. We demonstrate that shifting CGN cultures from 25 mM to 5 mM KCl-containing medium induces an early, transient 70% increase in phosphorylated Tyr402 and Tyr580 Pyk2 levels that is triggered by Ca(2+) released from intracellular stores and mediated by calmodulin (CaM). Overexpression of Pyk2 increases CGN survival after 24 h by 70% compared to the control, thus suggesting that Pyk2 is involved in an anti-apoptotic response to K+ lowering. Furthermore, we show that CGN grown in K25 medium exhibit detectable CaM-dependent Pyk2 activity. When silencing Pyk2 activity by expressing a dominant-negative form, only 40% of the transfected neurons were alive 24 h after transfection when compared to the control. Overall, the present findings demonstrate for the first time that Pyk2 is a critical mediator of CGN survival.
Collapse
Affiliation(s)
- Flavie Strappazzon
- Institut National de la Santé et de la Recherche Médicale (INSERM), Laboratoire Neurodégénérescence et Plasticité, EMI108, France
| | | | | | | | | | | |
Collapse
|
33
|
de Amicis F, Lanzino M, Kisslinger A, Calì G, Chieffi P, Andò S, Mancini FP, Tramontano D. Loss of proline-rich tyrosine kinase 2 function induces spreading and motility of epithelial prostate cells. J Cell Physiol 2006; 209:74-80. [PMID: 16783820 DOI: 10.1002/jcp.20709] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Although prostate carcinoma is an aggressive cancer preferentially metastasizing to the bones, many prostate tumors remain localized and confined to the prostate indefinitely. Prediction of the behavior of anatomically localized and moderately differentiated prostate tumors remains difficult because of lack of prognostic markers. Cell motility is an important step in the progression of epithelial tumor toward invasive metastatic carcinomas and changes in the expression and function of adhesion molecules contribute to the acquisition of a more malignant phenotype. Proline-rich tyrosine kinase 2 (Pyk2) is implicated in regulating the organization of actin cytoskeleton, a process critical for cell migration, mitosis, and tumor metastasis. In this report, we investigated whether Pyk2 played a role in the acquisition of an aggressive phenotype in prostate cell. Data reported here demonstrate that loss of Pyk2 kinase function results in induction of cell motility and migration in EPN cells, a line of non-transformed epithelial cells derived from human normal prostate tissue. Changes in motility and migration of prostate cells were associated with changes in the expression of several proteins involved in cell adhesion and reorganization of actin cytoskeleton. Ablation of Pyk2 kinase activity caused a dramatic decrease of the expression of E-cadherin and IRS1 and an increase of the expression of alpha5-integrin. In addition, a massive reorganization of actin cytoskeleton was observed. Our data indicate that Pyk2 plays a central role in the mechanism that regulate cell-cell and cell-substrate interaction and lack of its kinase activity induces prostate cells to acquire a malignant, migrating phenotype.
Collapse
Affiliation(s)
- Francesca de Amicis
- Dipartimento Farmaco-Biologico, Università della Calabria Arcavacata, Cosenza, Italy
| | | | | | | | | | | | | | | |
Collapse
|
34
|
Hambleton M, Hahn H, Pleger ST, Kuhn MC, Klevitsky R, Carr AN, Kimball TF, Hewett TE, Dorn GW, Koch WJ, Molkentin JD. Pharmacological- and gene therapy-based inhibition of protein kinase Calpha/beta enhances cardiac contractility and attenuates heart failure. Circulation 2006; 114:574-82. [PMID: 16880328 PMCID: PMC2707825 DOI: 10.1161/circulationaha.105.592550] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The conventional protein kinase C (PKC) isoform alpha functions as a proximal regulator of Ca2+ handling in cardiac myocytes. Deletion of PKCalpha in the mouse results in augmented sarcoplasmic reticulum Ca2+ loading, enhanced Ca2+ transients, and augmented contractility, whereas overexpression of PKCalpha in the heart blunts contractility. Mechanistically, PKCalpha directly regulates Ca2+ handling by altering the phosphorylation status of inhibitor-1, which in turn suppresses protein phosphatase-1 activity, thus modulating phospholamban activity and secondarily, the sarcoplasmic reticulum Ca2+ ATPase. METHODS AND RESULTS In the present study, we show that short-term inhibition of the conventional PKC isoforms with Ro-32-0432 or Ro-31-8220 significantly augmented cardiac contractility in vivo or in an isolated work-performing heart preparation in wild-type mice but not in PKCalpha-deficient mice. Ro-32-0432 also increased cardiac contractility in 2 different models of heart failure in vivo. Short-term or long-term treatment with Ro-31-8220 in a mouse model of heart failure due to deletion of the muscle lim protein gene significantly augmented cardiac contractility and restored pump function. Moreover, adenovirus-mediated gene therapy with a dominant-negative PKCalpha cDNA rescued heart failure in a rat model of postinfarction cardiomyopathy. PKCalpha was also determined to be the dominant conventional PKC isoform expressed in the adult human heart, providing potential relevance of these findings to human pathophysiology. CONCLUSIONS Pharmacological inhibition of PKCalpha, or the conventional isoforms in general, may serve as a novel therapeutic strategy for enhancing cardiac contractility in certain stages of heart failure.
Collapse
Affiliation(s)
- Michael Hambleton
- Department of Pediatrics, University of Cincinnati, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229-3039, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Gao BB, Hansen H, Chen HC, Feener E. Angiotensin II stimulates phosphorylation of an ectodomain-truncated platelet-derived growth factor receptor-beta and its binding to class IA PI3K in vascular smooth muscle cells. Biochem J 2006; 397:337-44. [PMID: 16569213 PMCID: PMC1513282 DOI: 10.1042/bj20060095] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
PI3K (phosphoinositide 3-kinase) activity is involved in Ang (angiotensin) II-stimulated VSMC (vascular smooth muscle cell) growth and hypertrophy. In the present study, we demonstrate that the inhibition of PI3K in VSMCs by expression of a dominant-negative p85alpha mutant lacking the p110-binding domain (Deltap85), or by treatment of cells with LY294002, inhibited Ang II-stimulated PAI-1 (plasminogen activator inhibitor-1) mRNA expression. Using a GST (glutathione S-transferase) fusion protein containing the p85 N-terminal SH2 (Src homology 2) domain as 'bait' followed by MS/MS (tandem MS), we identified a 70 kDa fragment of the p70 PDGFR-beta (platelet-derived growth factor receptor-beta) as a signalling adapter that is phosphorylated and recruits the p85 subunit of PI3K after Ang II stimulation of AT1 (Ang II subtype 1) receptors on VSMCs. This fragment of the PDGFR-beta, which has a truncation of its extracellular domain, accounted for approx. 15% of the total PDGFR-beta detected in VSMCs with an antibody against its cytoplasmic domain. Stimulation of VSMCs with Ang II increased tyrosine-phosphorylation of p70 PDGFR-beta at Tyr751 and Tyr1021 and increased its binding to p85. PDGF also induced phosphorylation of p70 PDGFR-beta, a response inhibited by the PDGF tyrosine kinase selective inhibitor, AG1296. By contrast, Ang II-induced phosphorylation of the 70 kDa receptor was not affected by AG1296. Ang II-stimulated phosphorylation of the p70 PDGFR-beta was blocked by the AT1 receptor antagonist, candesartan (CV 11974) and was partially inhibited by PP2 {4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine}, an Src family kinase inhibitor. Our result suggests that the p70 PDGFR-beta functions as an adapter that recruits PI3K to the membrane upon AT1 receptor stimulation.
Collapse
Affiliation(s)
- Ben-Bo Gao
- *Research Division, Joslin Diabetes Center, Harvard Medical School, Boston, MA 02215, U.S.A
| | - Hans Hansen
- †Eisai Research Institute, Wilmington, MA 01887, U.S.A
| | - Hong-Chi Chen
- ‡Department of Life Science, Tzu Chi University, Hualien 97004, Taiwan
| | - Edward P. Feener
- *Research Division, Joslin Diabetes Center, Harvard Medical School, Boston, MA 02215, U.S.A
- To whom correspondence should be addressed (email )
| |
Collapse
|
36
|
Han DW, Lim HR, Baek HS, Lee MH, Lee SJ, Hyon SH, Park JC. Inhibitory effects of epigallocatechin-3-O-gallate on serum-stimulated rat aortic smooth muscle cells via nuclear factor-kappaB down-modulation. Biochem Biophys Res Commun 2006; 345:148-55. [PMID: 16677605 DOI: 10.1016/j.bbrc.2006.04.072] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2006] [Accepted: 04/18/2006] [Indexed: 01/19/2023]
Abstract
The abnormal growth of vascular smooth muscle cells (VSMCs) plays an important role in vascular diseases, including atherosclerosis and restenosis after angioplasty. Although (-)-epigallocatechin-3-O-gallate (EGCG) has antiproliferative effects on various cells, relatively a little is known about precise mechanisms of the inhibitory effects of EGCG on SMCs. In this study, the inhibitory effects of EGCG on attachment, proliferation, migration, and cell cycle of rat aortic SMCs (RASMCs) with serum stimulation were investigated. Also, the involvement of nuclear factor-kappaB (NF-kappaB) during these inhibitions by EGCG was examined. EGCG treatment resulted in significant (p<0.05) inhibition in attachment and proliferation of RASMCs induced by serum. While non-treated RASMCs migrated into denuded area in response to serum and showed essentially complete closure after 36 h, EGCG-treated cells covered only 31% of the area even after 48 h of incubation. Furthermore, EGCG treatment resulted in an appreciable cell cycle arrest at both G0/G1- and G2/M-phases. The immunoblot analysis revealed that the constitutive expression of NF-kappaB/p65 nuclear protein in RASMCs was lowered by EGCG in both the cytosol and the nucleus in a dose-dependent manner. These results suggest that the EGCG-caused inhibitory effects on RASMCs may be mediated through NF-kappaB down-modulation.
Collapse
Affiliation(s)
- Dong-Wook Han
- Research Center for Nano Medical Engineering, Institute for Frontier Medical Sciences, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
| | | | | | | | | | | | | |
Collapse
|
37
|
Gavi S, Shumay E, Wang HY, Malbon CC. G-protein-coupled receptors and tyrosine kinases: crossroads in cell signaling and regulation. Trends Endocrinol Metab 2006; 17:48-54. [PMID: 16460957 DOI: 10.1016/j.tem.2006.01.006] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2005] [Revised: 12/19/2005] [Accepted: 01/19/2006] [Indexed: 12/11/2022]
Abstract
G-protein-coupled receptors and protein tyrosine kinases represent two prominent pathways for cellular signaling. As our knowledge of cell signaling pathways mediated by the superfamily of G-protein-coupled receptors and the smaller family of receptor tyrosine kinases expands, so does our appreciation of how these two major signaling platforms share information and modulate each other, otherwise termed "cross-talk". Cross-talk between G-protein-coupled receptors and tyrosine kinases can occur at several levels, including the receptor-to-receptor level, and at crucial downstream points (e.g. phosphatidylinositol-3-kinase, Akt/protein kinase B and the mitogen-activated protein kinase cascade). Regulation of G-protein-coupled receptors by non-receptor tyrosine kinases, such as Src family members, also operates in signaling. A broader understanding of how G-protein-coupled receptors and tyrosine kinases cross-talk reveals new insights into signaling modalities in both health and disease.
Collapse
Affiliation(s)
- Shai Gavi
- Department of Pharmacology, Diabetes and Metabolic Diseases Research Center, School of Medicine, State University of New York at Stony Brook, Stony Brook, NY 11794, USA.
| | | | | | | |
Collapse
|
38
|
Wu SS, Jácamo RO, Vong SK, Rozengurt E. Differential regulation of Pyk2 phosphorylation at Tyr-402 and Tyr-580 in intestinal epithelial cells: roles of calcium, Src, Rho kinase, and the cytoskeleton. Cell Signal 2006; 18:1932-40. [PMID: 16574377 DOI: 10.1016/j.cellsig.2006.02.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2006] [Revised: 02/21/2006] [Accepted: 02/22/2006] [Indexed: 10/25/2022]
Abstract
The calcium-dependent proline-rich tyrosine kinase Pyk2 is activated by tyrosine phosphorylation, associates with focal adhesion proteins, and has been linked to proliferative and migratory responses in a variety of mesenchymal and epithelial cell types. Full Pyk2 activation requires phosphorylation at functionally distinct sites, including autophosphorylation site Tyr-402 and catalytic domain site Tyr-580, though the mechanisms involved are unclear. The pathways mediating Pyk2 phosphorylation at Tyr-402 and Tyr-580 were therefore investigated. Both sites were rapidly and transiently phosphorylated following cell stimulation by Ang II or LPA. However, only Tyr-580 phosphorylation was rapidly enhanced by intracellular Ca(2+) release, or inhibited by Ca(2+) depletion. Conversely, Tyr-402 phosphorylation was highly sensitive to inhibition of actin stress fibers, or of Rho kinase (ROK), an upstream regulator of stress fiber assembly. Ang II also induced a delayed (30-60 min) secondary phosphorylation peak occurring at Tyr-402 alone. Unlike the homologous focal adhesion kinase (FAK), Pyk2 phosphorylation was sensitive neither to the Src inhibitor PP2, nor to truncation of its N-terminal region, which contains a putative autoinhibitory FERM domain. These results better define the mechanisms involved in Pyk2 activation, demonstrating that autophosphorylation is ROK- and stress fiber-dependent, while transphosphorylation within the kinase domain is Ca(2+)-dependent and Src-independent in intestinal epithelial cells. This contrasts with the tight sequential coupling of phosphorylation seen in FAK activation, and further underlines the differences between these closely related kinases.
Collapse
Affiliation(s)
- Steven S Wu
- Department of Pediatrics, David Geffen School of Medicine, University of California-Los Angeles, 900 Veteran Avenue, Los Angeles, CA 90095, USA.
| | | | | | | |
Collapse
|
39
|
Koshida R, Rocic P, Saito S, Kiyooka T, Zhang C, Chilian WM. Role of Focal Adhesion Kinase in Flow-Induced Dilation of Coronary Arterioles. Arterioscler Thromb Vasc Biol 2005; 25:2548-53. [PMID: 16195476 DOI: 10.1161/01.atv.0000188511.84138.9b] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Backgound—
Flow-induced regulation of endothelial NO synthase (eNOS) depends on integrin signaling and tyrosine kinase activation. Integrins cluster in focal adhesion complexes, where the extracellular matrix is connected to the cytoskeleton and where focal adhesion kinase (FAK) is located. FAK plays a central role in integrin signaling and Src activation. Accordingly, we hypothesized that FAK plays an important role in flow-induced dilation (FID).
Methods and Results—
To inactivate FAK-dependent signaling, anti-FAK, phosphospecific (Tyr
397
) antibody (FAKab), which binds against the FAK autophosphorylation site, was incorporated into endothelium of rat coronary arterioles using liposomal transfection. The responses to flow, acetylcholine (Ach), or the NO donor MAHAMANONOate (NOC-9) were observed before and after FAKab. In control and vehicles (denatured antibody or transfecting reagent alone), flow produced progressive dilation to a maximal value of 35% increase in diameter, which was inhibited by
N
ω
-nitro-
l
-arginine methyl ester (
l
-NAME). However, FAKab prevented FID (
P
<0.01 versus control). Combined treatment with FAKab and
l
-NAME did not produce inhibition greater than FAKab alone. FAKab did not blunt Ach- or NOC-9–induced dilation. Western analysis demonstrated that FAKab prevented flow-induced phosphorylation of FAK (pY397-FAK), Akt (pS473-Akt), and eNOS (pS1179-eNOS).
Conclusion—
Our study demonstrates the pivotal role of FAK in NO-mediated FID. Inhibition of FAK signaling with FAKab impaired FID and phosphorylation of Akt and eNOS. Our data suggest that the activation of FAK is central to the mechanotransduction of FID via regulation of activation of Akt and eNOS.
Collapse
Affiliation(s)
- Ryoji Koshida
- Department of Physiology, Louisiana State University Health Sciences Center, New Orleans, LA, USA
| | | | | | | | | | | |
Collapse
|
40
|
Abstract
Angiotensin-converting enzyme (ACE) plays a pivotal role in the renin-angiotensin system (RAS) and ACE-inhibitors are widely used in several clinical conditions, including hypertension and heart failure. Recently, a homologue of ACE, ACE(2) has been discovered. Both ACE and ACE(2) are emerging as key enzymes of the RAS, where ACE(2) may play a role as negative regulator of ACE. Moreover, ACE(2) appears to be an important enzyme outside the classical RAS, as it hydrolyzes apelins, dynorphin A 1-13, des-Arg-bradykinin and other peptide substrates. The precise interplay between tissue ACE, ACE(2), and their substrates and by-products are presently still unclear.ACE-inhibitors reduce angiotensin II formation and bradykinin degradation, but do not inhibit ACE(2) activity. Moreover, ACE-inhibitors differ in their affinity for tissue ACE, and it has been suggested that tissue ACE affinity might be responsible for some of the beneficial properties of these drugs. ACE-inhibitors also increase nitric oxide availability, and activate several kinases that may regulate protein synthesis by interacting with the nucleus of the cells (outside-in signaling). The outside-in signaling may also be activated by bradykinin itself. Although, the precise significance of the outside-in signaling is still unclear, this new role of ACE-inhibitors may represent a discriminant factor versus angiotensin II receptors antagonists. This mini review will summarize some new aspects concerning the recently discovered biological functions of RAS and in particular of ACE, ACE(2) and ACE-inhibitors in cardiovascular system.
Collapse
Affiliation(s)
- Pasquale Pagliaro
- Dipartimento di Scienze Cliniche e Biologiche, Università degli Studi di Torino, Italy.
| | | |
Collapse
|
41
|
Basile JR, Afkhami T, Gutkind JS. Semaphorin 4D/plexin-B1 induces endothelial cell migration through the activation of PYK2, Src, and the phosphatidylinositol 3-kinase-Akt pathway. Mol Cell Biol 2005; 25:6889-98. [PMID: 16055703 PMCID: PMC1190270 DOI: 10.1128/mcb.25.16.6889-6898.2005] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Semaphorins are cell surface and secreted proteins that provide axonal guidance in neuronal tissues and regulate cell motility in many cell types. They act by binding a family of transmembrane receptors known as plexins, which belong to the c-Met family of scatter factor receptors but lack an intrinsic tyrosine kinase domain. Interestingly, we have recently shown that Plexin-B1 is highly expressed in endothelial cells and that its activation by Semaphorin 4D elicits a potent proangiogenic response (J. R. Basile, A. Barac, T. Zhu, K. L. Guan, and J. S. Gutkind, Cancer Res. 64:5212-5224, 2004). In searches for the underlying molecular mechanism, we observed that Semaphorin 4D-stimulated endothelial cell migration requires the activation of the phosphatidylinositol 3-kinase (PI3K)-Akt pathway. Surprisingly, we found that Plexin-B1 stimulates PI3K-Akt through the activation of an intracellular tyrosine kinase cascade that involves the sequential activation of PYK2 and Src. This results in the tyrosine phosphorylation of Plexin-B1, the rapid recruitment of a multimeric signaling complex that includes PYK2, Src, and PI3K to Plexin-B1 and the activation of Akt. These findings suggest that Plexin-B1 may achieve its numerous physiological functions through the direct activation of intracellular tyrosine kinase cascades.
Collapse
Affiliation(s)
- John R Basile
- Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892, USA.
| | | | | |
Collapse
|
42
|
Yosypiv IV, El-Dahr SS. Role of the renin-angiotensin system in the development of the ureteric bud and renal collecting system. Pediatr Nephrol 2005; 20:1219-29. [PMID: 15942783 DOI: 10.1007/s00467-005-1944-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2005] [Revised: 03/02/2005] [Accepted: 03/02/2005] [Indexed: 11/24/2022]
Abstract
Genetic, biochemical and physiological studies have demonstrated that the renin-angiotensin system (RAS) plays a fundamental role in kidney development. All of the components of the RAS are expressed in the metanephros. Mutations in the genes encoding components of the RAS in mice or pharmacological inhibition of RAS in animals or humans cause diverse congenital abnormalities of the kidney and lower urinary tract. The latter include renal vascular abnormalities, abnormal glomerulogenesis, renal papillary hypoplasia, hydronephrosis, aberrant UB budding, duplicated collecting system, and urinary concentrating defect. Thus, the actions of angiotensin (ANG) II during kidney development are pleiotropic both spatially and temporally. Whereas the role of ANG II in renovascular and glomerular development has received much attention, little is known about the potential role of ANG II and its receptors in the morphogenesis of the collecting system. In this review, we discuss recent genetic and functional evidence gathered from transgenic knockout mice and in vitro organ and cell culture implicating the RAS in the development of the ureteric bud and collecting ducts. A novel conceptual framework has emerged from this body of work which states that stroma-derived ANG II elicits activation of AT(1)/AT(2) receptors expressed on the ureteric bud to stimulate branching morphogenesis as well as collecting duct elongation and papillogenesis.
Collapse
Affiliation(s)
- Ihor V Yosypiv
- Section of Pediatric Nephrology, Department of Pediatrics, Tulane University Health Sciences Center, New Orleans, LA 70112, USA.
| | | |
Collapse
|
43
|
Derbyshire ZE, Halfter UM, Heimark RL, Sy TH, Vaillancourt RR. Angiotensin II stimulated transcription of cyclooxygenase II is regulated by a novel kinase cascade involving Pyk2, MEKK4 and annexin II. Mol Cell Biochem 2005; 271:77-90. [PMID: 15881658 DOI: 10.1007/s11010-005-5386-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Although it is known that MEKK4 regulates MKK6, and p38 MAP kinase, extracellular stimuli that activate the serine/threonine kinase, MEKK4, are unknown. The aim of this study was then to identify stimuli that regulate MEKK4. By using recombinant MEKK4, as bait to attract interacting proteins, the calcium binding protein, annexin II, was identified by mass spectrometry as interacting with MEKK4, suggesting that MEKK4 might be regulated by calcium. A calcium-dependent interaction between MEKK4 and annexin II was observed when MEKK4 was immunoprecipitated from rat aortic smooth muscle cells that were treated with angiotensin II. Additional studies using recombinant MEKK4 in a Far-Western immunoblot identified a protein of 120 kDa as interacting directly with MEKK4. Prior studies indicated that MEKK4 was phosphorylated on tyrosine in vivo, and in fact, Pyk2 interacts with MEKK4 in an angiotensin II dependent manner in rat aortic smooth muscle cells. Pyk2 phosphorylates MEKK4 in vitro and Pyk2-dependent phosphorylation further regulates MEKK4-dependent phosphorylation of MKK6. Finally, dominant-negative MEKK4 inhibits angiotensin II mediated transcription of a luciferase reporter construct containing the cyclooxygenase II promoter, demonstrating that MEKK4 functions in a calcium-dependent manner as a substrate for Pyk2 and regulates transcription of cyclooxygenase II.
Collapse
Affiliation(s)
- Zachary E Derbyshire
- Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ 85721, USA
| | | | | | | | | |
Collapse
|
44
|
Mariappan MM, Senthil D, Natarajan KS, Choudhury GG, Kasinath BS. Phospholipase Cγ-Erk Axis in Vascular Endothelial Growth Factor-induced Eukaryotic Initiation Factor 4E Phosphorylation and Protein Synthesis in Renal Epithelial Cells. J Biol Chem 2005; 280:28402-11. [PMID: 15919658 DOI: 10.1074/jbc.m504861200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Vascular endothelial growth factor (VEGF) increases protein synthesis and induces hypertrophy in renal tubular epithelial cells (Senthil, D., Choudhury, G. G., McLaurin, C., and Kasinath, B. S. (2003) Kidney Int. 64, 468-479). We examined the role of Erk1/2 MAP kinase in protein synthesis induced by VEGF. VEGF stimulated Erk phosphorylation that was required for induction of protein synthesis. VEGF-induced Erk activation was not dependent on phosphoinositide (PI) 3-kinase activation but required sequential phosphorylation of type 2 VEGF receptor, PLCgamma and c-Src, as demonstrated by inhibitors SU1498, U73122, and PP1, respectively. c-Src phosphorylation was inhibited by U73122, indicating it was downstream of phospholipase (PL)Cgamma. Studies with PP1/2 showed that phosphorylation of c-Src was required for tyrosine phosphorylation of Raf-1, an upstream regulator of Erk. VEGF also stimulated phosphorylation of Pyk-2; VEGF-induced phosphorylation of Pyk2, c-Src and Raf-1 could be abolished by BAPTA/AM, demonstrating requirement for induction of intracellular calcium currents. We examined the downstream events following the phosphorylation of Erk. VEGF stimulated phosphorylation of Mnk1 and eIF4E and induced Mnk1 to shift from the cytoplasm to the nucleus upon phosphorylation. VEGF-induced phosphorylation of Mnk1 and eIF4E required phosphorylation of PLCgamma, c-Src, and Erk. Expression of dominant negative Mnk1 abrogated eIF4E phosphorylation and protein synthesis induced by VEGF. VEGF-stimulated protein synthesis could be blocked by inhibition of PLCgamma by a chemical inhibitor or expression of a dominant negative construct. Our data demonstrate that VEGF-stimulated protein synthesis is Erk-dependent and requires the activation of VEGF receptor 2, PLCgamma, c-Src, Raf, and Erk pathway. VEGF also stimulates Erk-dependent phosphorylation of Mnk1 and eIF4E, crucial events in the initiation phase of protein translation.
Collapse
Affiliation(s)
- Meenalakshmi M Mariappan
- O'Brien Kidney Research Center, Department of Medicine, University of Texas Health Science Center, South Texas Veterans Healthcare System, Geriatric Research, Education, and, Clinical Center, San Antonio, Texas 78229, USA
| | | | | | | | | |
Collapse
|
45
|
Shah BH, Neithardt A, Chu DB, Shah FB, Catt KJ. Role of EGF receptor transactivation in phosphoinositide 3-kinase-dependent activation of MAP kinase by GPCRs. J Cell Physiol 2005; 206:47-57. [PMID: 15920762 DOI: 10.1002/jcp.20423] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Many G protein coupled receptors (GPCRs) cause phosphorylation of MAP kinases through transactivation of the epidermal growth factor receptor (EGF-R), leading to increased cell survival and growth, motility, and migration. Phosphoinositide 3-kinase (PI3K) is one of the important cell survival signaling molecules activated by EGF-R stimulation. However, the extent to which EGF-R transactivation is essential for GPCR agonist-stimulated PI3K activation is not known. Here we examined the mechanism of PI3K activation that elicits GPCR-mediated ERK1/2 activation by pathways dependent and/or independent of EGF-R transactivation in specific cell types. Immortalized hypothalamic neurons (GT1-7 cells) express endogenous gonadotropin-releasing hormone receptors (GnRH-R) and their stimulation causes marked phosphorylation of ERK1/2 and Akt (Ser 473) through transactivation of the EGF-R and recruitment of PI3K. In C9 hepatocytes, agonist activation of AT1 angiotensin II (AT1-R), lysophosphatidic acid (LPA), and EGF receptors caused phosphorylation of Akt through activation of the EGF-R in a PI3K-dependent manner. However, ERK1/2 activation by these agonists in these cells was independent of PI3K activation. In contrast, agonist stimulation of HEK 293 cells stably expressing AT1-R caused ERK1/2 phosphorylation that was independent of EGF-R transactivation but required PI3K activation. LPA signaling in these cells showed partial and complete dependence on EGF-R and PI3K, respectively. These data indicate that GPCR-induced ERK1/2 phosphorylation is dependent or independent of PI3K in specific cell types, and that the involvement of PI3K during ERK1/2 activation is not dependent solely on agonist-induced transactivation of the EGF-R.
Collapse
Affiliation(s)
- Bukhtiar H Shah
- Endocrinology and Reproduction Research Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892-4510, USA.
| | | | | | | | | |
Collapse
|
46
|
Wiedmann M, Wang X, Tang X, Han M, Li M, Mao Z. PI3K/Akt-dependent regulation of the transcription factor myocyte enhancer factor-2 in insulin-like growth factor-1- and membrane depolarization-mediated survival of cerebellar granule neurons. J Neurosci Res 2005; 81:226-34. [PMID: 15931671 DOI: 10.1002/jnr.20556] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Survival signals such as insulin-like growth factor-1 (IGF-1) or membrane depolarization convey their neuronal protective effects through the activation of signaling networks and nuclear factors. In cerebellar granule neurons, IGF-1 mediates survival primarily through the PI3K/Akt pathway. The function of the transcription factor myocyte enhancer factor-2 (MEF2) is required for mediating membrane depolarization-dependent neuronal survival. However, whether PI3K/Akt regulates MEF2 and the role of MEF2 in IGF-1-mediated survival of neurons are unknown. In addition, the contribution of the PI3K/Akt pathway in membrane depolarization-induced neuronal survival remains undefined. We show here that the PI3K/Akt pathway promotes the survival of cerebellar granule neurons derived from Long-Evans rats following IGF-1 stimulation or membrane depolarization through regulation of MEF2 activity. IGF-1 stimulated the gene transactivation activity of MEF2 and its DNA binding potential. Moreover, regulation of MEF2 function by IGF-1 was dependent on the activity of the PI3K/Akt signaling pathway. Blocking MEF2 function reduced IGF-1-induced survival of cerebellar granule neurons. Membrane depolarization stimulated phosphorylation of Akt in cerebellar granule neurons. Blocking of the PI3K/Akt pathway with either a pharmacological inhibitor of PI3K, LY294002, or dominant negative mutants of PI3K and Akt inhibited the membrane depolarization-induced increase in MEF2 transactivation as well as its DNA binding activity and reduced neuronal survival. Together, these findings provide clear evidence to support an important role of the PI3K/Akt pathway in the regulation of nuclear survival factor MEF2 upon either IGF-1 stimulation or membrane depolarization, thus placing MEF2 as a novel downstream effector of the PI3K/Akt pathway in neurons.
Collapse
Affiliation(s)
- M Wiedmann
- Department of Medicine, Rhode Island Hospital and Brown Medical School, Providence, Rhode Island, USA
| | | | | | | | | | | |
Collapse
|
47
|
Lucchesi PA, Sabri A, Belmadani S, Matrougui K. Involvement of metalloproteinases 2/9 in epidermal growth factor receptor transactivation in pressure-induced myogenic tone in mouse mesenteric resistance arteries. Circulation 2004; 110:3587-93. [PMID: 15557365 DOI: 10.1161/01.cir.0000148780.36121.47] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Epidermal growth factor receptor (EGFR) transactivation is a mediator of angiotensin II (Ang II) signaling in cultured vascular smooth muscle cells isolated from large arteries. The present study used mouse mesenteric resistance arteries (MRAs) to investigate the role of EGFR transactivation under pressure-induced myogenic tone (MT). METHODS AND RESULTS Isolated MRAs were mounted in an arteriograph and stimulated by 25 to 125 mm Hg or with Ang II and KCl. Stepwise increases in pressure resulted in MT development associated with increased EGFR phosphorylation and release of heparin-binding EGF (HB-EGF), a membrane-bound growth factor that is shed on cleavage by metalloproteinases. EGF (50 ng/mL) potentiated MT (59+/-1% to 51+/-0.6% of passive diameter at 75 mm Hg). Pretreatment with the EGFR inhibitors AG1478 (5 micromol/L) or PD153035 (1 micromol/L) significantly decreased MT. However, EGFR inhibitors had no effect on Ang II- and KCl-induced contraction. MT was potentiated by HB-EGF, 50 ng/mL, which is bound to the cell membrane and released on cleavage by metalloproteinases. Neutralizing HB-EGF antibodies or heparin treatment to sequester HB-EGF resulted in significant inhibition of pressure-induced MT. MT increased matrix metalloproteinase (MMP) 2 and MMP-9 gelatinase activity assessed by zymography, and specific MMP 2/9 inhibitors significantly decreased MT. CONCLUSIONS These novel findings suggest that the mechanism of pressure-induced MT involves metalloproteinases 2/9 activation with subsequent HB-EGF release and EGFR transactivation.
Collapse
Affiliation(s)
- Pamela A Lucchesi
- Department of Pharmacology, Louisiana State University Health Sciences Center, New Orleans, USA
| | | | | | | |
Collapse
|
48
|
Corvol JC, Valjent E, Toutant M, Enslen H, Irinopoulou T, Lev S, Hervé D, Girault JA. Depolarization activates ERK and proline-rich tyrosine kinase 2 (PYK2) independently in different cellular compartments in hippocampal slices. J Biol Chem 2004; 280:660-8. [PMID: 15537634 DOI: 10.1074/jbc.m411312200] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In the hippocampus, extracellular signal-regulated kinase (ERK) and the non-receptor protein proline-rich tyrosine kinase 2 (PYK2) are activated by depolarization and involved in synaptic plasticity. Both are also activated under pathological conditions following ischemia, convulsions, or electroconvulsive shock. Although in non-neuronal cells PYK2 activates ERK through the recruitment of Src-family kinases (SFKs), the link between these pathways in the hippocampus is not known. We addressed this question using K(+)-depolarized rat hippocampal slices. Depolarization increased the phosphorylation of PYK2, SFKs, and ERK. These effects resulted from Ca(2+) influx through voltage-gated Ca(2+) channels and were diminished by GF109203X, a protein kinase C inhibitor. Inhibition of SFKs with PP2 decreased PYK2 tyrosine phosphorylation dramatically, but not its autophosphorylation on Tyr-402. Moreover, PYK2 autophosphorylation and total tyrosine phosphorylation were profoundly altered in fyn-/- mice, revealing an important functional relationship between Fyn and PYK2 in the hippocampus. In contrast, ERK activation was unaltered by PP2, Fyn knock-out, or LY294002, a phosphatidyl-inositol-3-kinase inhibitor. ERK activation was prevented by MEK inhibitors that had no effect on PYK2. Immunofluorescence of hippocampal slices showed that PYK2 and ERK were activated in distinct cellular compartments in somatodendritic regions and nerve terminals, respectively, with virtually no overlap. Activation of ERK was critical for the rephosphorylation of a synaptic vesicle protein, synapsin I, following depolarization, underlining its functional importance in nerve terminals. Thus, in hippocampal slices, in contrast to cell lines, depolarization-induced activation of non-receptor tyrosine kinases and ERK occurs independently in distinct cellular compartments in which they appear to have different functional roles.
Collapse
Affiliation(s)
- Jean-Christophe Corvol
- Signal Transduction and Plasticity in the Nervous System Unit, INSERM/Université Pierre et Marie Curie U536, Institut du Fer à Moulin, 75005 Paris, France
| | | | | | | | | | | | | | | |
Collapse
|
49
|
Liou SF, Yeh JL, Liang JC, Chiu CC, Lin YT, Chen IJ. Inhibition of Mitogen-Mediated Proliferation of Rat Vascular Smooth Muscle Cells by Labedipinedilol-A through PKC and ERK 1/2 Pathway. J Cardiovasc Pharmacol 2004; 44:539-51. [PMID: 15505490 DOI: 10.1097/00005344-200411000-00005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Labedipinedilol-A is a novel 1, 4-dihydropyridine type calcium antagonist with alpha-receptor blocking activity. This study investigates the effects of labedipinedilol-A on mitogen-induced proliferation of rat vascular smooth muscle cells (VSMCs). Labedipinedilol-A's inhibition on cell proliferation was measured by the tetrazolium salt (XTT) test. Labedipinedilol-A dose-dependently inhibited mitogen-induced DNA synthesis, determined by the incorporation of 5-bromo-2'-deoxyuridine (BrdU). Labedipinedilol-A was also found capable of inhibiting the migration of VSMCs induced by PDGF-BB with an IC50 value of 5.6 microM. In accordance with these findings, labedipinedilol-A revealed blocking of the FBS-inducible progression through G0/G1 to S phase of the cell cycle in synchronized cells. Labedipinedilol-A appeared to cause inhibition of mitogens-induced PKC translocation, suggesting the probable involvement of protein kinase C (PKC) in this cellular response. Labedipinedilol-A reduced both intracellular Ca and the phosphorylation of extracellular signal-regulated protein kinase 1/2 in PDGF-BB-stimulated VSMCs. It also suppressed the levels of proliferative cell nuclear antigen (PCNA) in VSMCs both time- and dose-dependently. These results indicate that labedipinedilol-A may inhibit cell proliferation by attenuating activation of the ERK 1/2 pathway, which is regulated by PKC and Ca, suggesting that it may have great potential in the prevention of progressive atherosclerosis.
Collapse
MESH Headings
- Animals
- Anisoles/metabolism
- Anisoles/pharmacology
- Aorta, Thoracic/pathology
- Bromodeoxyuridine/pharmacology
- Calcium/metabolism
- Cell Culture Techniques
- Cell Movement/drug effects
- Cell Movement/genetics
- Cell Proliferation/drug effects
- China
- DNA/antagonists & inhibitors
- DNA/metabolism
- Dihydropyridines/chemistry
- Dihydropyridines/metabolism
- Dihydropyridines/pharmacology
- Dose-Response Relationship, Drug
- Drug Evaluation, Preclinical/methods
- Focal Adhesion Kinase 2
- Humans
- Interphase/drug effects
- Isoenzymes/chemistry
- Isoenzymes/metabolism
- MAP Kinase Kinase 2
- Male
- Mitogen-Activated Protein Kinase 1/antagonists & inhibitors
- Mitogen-Activated Protein Kinase 1/drug effects
- Mitogen-Activated Protein Kinase 1/metabolism
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Phosphorylation/drug effects
- Platelet-Derived Growth Factor/metabolism
- Platelet-Derived Growth Factor/pharmacology
- Proliferating Cell Nuclear Antigen/drug effects
- Proliferating Cell Nuclear Antigen/genetics
- Proliferating Cell Nuclear Antigen/metabolism
- Proline/chemistry
- Protein Kinase C/chemistry
- Protein Kinase C/metabolism
- Protein-Tyrosine Kinases/chemistry
- Protein-Tyrosine Kinases/metabolism
- Rats
- Rats, Wistar
- Umbilical Veins/drug effects
- Umbilical Veins/metabolism
- Umbilical Veins/pathology
Collapse
Affiliation(s)
- Shu-Fen Liou
- Department of Pharmacology, Kaohsiung Medical University, Kaohsiung, Taiwan
| | | | | | | | | | | |
Collapse
|
50
|
Melikova S, Dylla SJ, Verfaillie CM. Phosphatidylinositol-3-kinase activation mediates proline-rich tyrosine kinase 2 phosphorylation and recruitment to β1-integrins in human CD34+ cells. Exp Hematol 2004; 32:1051-6. [PMID: 15539082 DOI: 10.1016/j.exphem.2004.07.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2004] [Revised: 07/22/2004] [Accepted: 07/23/2004] [Indexed: 10/26/2022]
Abstract
OBJECTIVE beta1-integrins mediate hematopoietic stem and progenitor cell homing and retention in the bone marrow (BM) and inhibit hematopoietic proliferation and differentiation. Having no intrinsic kinase activity, integrins recruit intracellular kinases, such as the focal adhesion kinase (FAK) or the related proline-rich tyrosine kinase 2 (PYK2), to initiate signal transduction. Phosphatidylinositol-3-kinase (PI3K), which is involved in beta1-integrin signaling in many cell types, is physically and functionally associated with FAK in anchorage-dependent cells. Because PYK2 is the principal focal adhesion kinase expressed in primary human CD34+ cells, we assessed its functional relationship with PI3K in CD34+ cells in response to integrin engagement. METHODS beta1-integrins on primary mobilized peripheral blood CD34+ cells and CD34+ KG1A cells were engaged by adhesion to fibronectin (FN) or by cross-linking with an anti-beta1 integrin antibody, respectively. PI3K activity and PYK2 phosphorylation were then assessed in the presence or absence of the PI3K inhibitor, wortmannin. Association between PI3K, PYK2, and the beta1-integrin subunit were also evaluated in co-immunoprecipitation experiments. RESULTS beta1-integrin engagement induced PI3K activation, which was required for, and temporally preceded, PYK2 phosphorylation, indicating that PI3K lies upstream of PYK2 in CD34+ cells. Furthermore, although PYK2 and PI3K were constitutively associated, interaction of the PYK2/PI3K complex with beta1-integrins required prior integrin engagement and PI3K activation. CONCLUSION Activation of PI3K following beta1-integrin engagement on human CD34+ cells results in subsequent phosphorylation of PYK2, and is required for the recruitment of the PI3K/PYK2 complex to beta1-integrins at the cell surface.
Collapse
Affiliation(s)
- Sofya Melikova
- Stem Cell Institute, University of Minnesota, Minneapolis, Minnesota, USA
| | | | | |
Collapse
|