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Mihanfar A, Sadigh AR, Fattahi A, Latifi Z, Hasanzadeh-Moghadam M, Samadi M, Farzadi L, Hamdi K, Ghasemzadeh A, Nejabati HR, Nouri M. Endothelins and their receptors in embryo implantation. J Cell Biochem 2019; 120:14274-14284. [PMID: 31106465 DOI: 10.1002/jcb.28983] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 03/31/2019] [Accepted: 04/08/2019] [Indexed: 12/12/2022]
Abstract
As a critical stage of pregnancy, the implantation of blastocysts into the endometrium is a progressive, excessively regulated local tissue remodeling step involving a complex sequence of genetic and cellular interplay executed within an optimal time frame. For better understanding the causes of infertility and, more importantly, for developing powerful strategies for successful implantations and combating infertility, an increasing number of recent studies have been focused on the identification and study of newly described substances in the reproductive tree. The endothelins (ET), a 21-aminoacidic family of genes, have been reported to be responsible for the contraction of vascular and nonvascular smooth muscles, including the smooth muscles of the uterus. Therefore, this review aims to comprehensively discuss the physiological role of endothelins and signaling through their receptors, as well as their probable involvement in the implantation process.
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Affiliation(s)
- Aynaz Mihanfar
- Department of Biochemistry, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | - Aydin Raei Sadigh
- Department of Biochemistry and Clinical Laboratories, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Amir Fattahi
- Department of Reproductive Biology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Zeinab Latifi
- Department of Biochemistry and Clinical Laboratories, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.,Stem Cell and Regenerative Medicine Institute, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - Mahrokh Samadi
- Nephrology and Kidney Transplant Research Center, Urmia University of Medical Sciences, Urmia, Iran
| | - Laya Farzadi
- Department of Reproductive Biology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Kobra Hamdi
- Department of Reproductive Biology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Aliyeh Ghasemzadeh
- Department of Reproductive Biology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Hamid Reza Nejabati
- Department of Biochemistry and Clinical Laboratories, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.,Stem Cell and Regenerative Medicine Institute, Tabriz University of Medical Sciences, Tabriz, Iran.,Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran.,Stem Cell Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad Nouri
- Department of Reproductive Biology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran.,Stem Cell and Regenerative Medicine Institute, Tabriz University of Medical Sciences, Tabriz, Iran
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2
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Haug MF, Berger M, Gesemann M, Neuhauss SCF. Differential expression of PKCα and -β in the zebrafish retina. Histochem Cell Biol 2019; 151:521-530. [PMID: 30604284 DOI: 10.1007/s00418-018-1764-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/19/2018] [Indexed: 01/08/2023]
Abstract
The retina is a complex neural circuit, which processes and transmits visual information from light perceiving photoreceptors to projecting retinal ganglion cells. Much of the computational power of the retina rests on signal integrating interneurons, such as bipolar cells. Commercially available antibodies against bovine and human conventional protein kinase C (PKC) α and -β are frequently used as markers for retinal ON-bipolar cells in different species, despite the fact that it is not known which bipolar cell subtype(s) they actually label. In zebrafish (Danio rerio) five prkc genes (coding for PKC proteins) have been identified. Their expression has not been systematically determined. While prkcg is not expressed in retinal tissue, the other four prkc (prkcaa, prkcab, prkcba, prkcbb) transcripts were found in different parts of the inner nuclear layer and some as well in the retinal ganglion cell layer. Immunohistochemical analysis in adult zebrafish retina using fluorescent in situ hybridization and PKC antibodies showed an overlapping immunolabeling of ON-bipolar cells that are most likely of the BON s6 and BON s6L or RRod type. However, comparison of transcript expression with immunolabeling, implies that these antibodies are not specific for one single zebrafish conventional PKC, but rather detect a combination of PKC -α and -β variants.
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Affiliation(s)
- Marion F Haug
- Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Manuela Berger
- Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Matthias Gesemann
- Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Stephan C F Neuhauss
- Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.
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3
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Lorca RA, Prabagaran M, England SK. Functional insights into modulation of BKCa channel activity to alter myometrial contractility. Front Physiol 2014; 5:289. [PMID: 25132821 PMCID: PMC4116789 DOI: 10.3389/fphys.2014.00289] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Accepted: 07/14/2014] [Indexed: 12/15/2022] Open
Abstract
The large-conductance voltage- and Ca(2+)-activated K(+) channel (BKCa) is an important regulator of membrane excitability in a wide variety of cells and tissues. In myometrial smooth muscle, activation of BKCa plays essential roles in buffering contractility to maintain uterine quiescence during pregnancy and in the transition to a more contractile state at the onset of labor. Multiple mechanisms of modulation have been described to alter BKCa channel activity, expression, and cellular localization. In the myometrium, BKCa is regulated by alternative splicing, protein targeting to the plasma membrane, compartmentation in membrane microdomains, and posttranslational modifications. In addition, interaction with auxiliary proteins (i.e., β1- and β2-subunits), association with G-protein coupled receptor signaling pathways, such as those activated by adrenergic and oxytocin receptors, and hormonal regulation provide further mechanisms of variable modulation of BKCa channel function in myometrial smooth muscle. Here, we provide an overview of these mechanisms of BKCa channel modulation and provide a context for them in relation to myometrial function.
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Affiliation(s)
- Ramón A Lorca
- Department of Obstetrics and Gynecology, Washington University in St. Louis School of Medicine St. Louis, MO, USA
| | - Monali Prabagaran
- Department of Obstetrics and Gynecology, Washington University in St. Louis School of Medicine St. Louis, MO, USA
| | - Sarah K England
- Department of Obstetrics and Gynecology, Washington University in St. Louis School of Medicine St. Louis, MO, USA
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Jofré NM, Delpiano AM, Cuello MA, Poblete JA, Vargas PA, Carvajal JA. Isoform α of PKC may contribute to the maintenance of pregnancy myometrial quiescence in humans. Reprod Sci 2012; 20:69-77. [PMID: 22872490 DOI: 10.1177/1933719112450335] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We postulate that protein kinase C α (PKCα) may contribute to the maintenance of pregnancy myometrial quiescence in humans. We studied the changes in myometrial PKCα gene products (messenger RNA [mRNA] and protein) in 4 groups of women: preterm not in labor (PT-NL), preterm in labor (PT-L), term not in labor (T-NL), and term in labor (T-L). The degree of PKCα activation was studied by comparing the levels of particulate (active) PKCα with the total PKCα protein levels and by measuring PKCα activity in the cytosolic and particulate fractions. Protein kinase Cα abundance (mRNA and protein) did not increase during myometrial quiescence (PT-NL), whereas the level of PKCα activity significantly increased during quiescence. The activity of PKCα significantly decreased in the T-NL, T-L, and PT-L groups. These findings suggest that PKCα plays a significant role in the maintenance of myometrial quiescence and that PKCα activity must decrease at the end of pregnancy allowing myometrial activation. Additionally, our data demonstrate an association between reduced PKCα activity and preterm labor, which merits further investigation.
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Affiliation(s)
- Nicolás M Jofré
- Unidad de Medicina Materno Fetal, División de Obstetricia y Ginecología, Pontificia Universidad Católica de Chile, Santiago, Chile
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5
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Tanfin Z, Breuiller-Fouché M. The endothelin axis in uterine leiomyomas: new insights. Biol Reprod 2012; 87:5, 1-10. [PMID: 22553222 DOI: 10.1095/biolreprod.111.097725] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The endothelin axis, comprising endothelin-1 (ET-1) and its receptors (ETA and ETB), is involved in the pathophysiology of different human tumors. Here we review conventional approaches and gene expression profiling indicating the association of ET-1 and its cognate receptors with human and rat leiomyomas, the most common benign tumors of myometrium. Specifically, ET-1/ETA interactions affect human and rat leiomyoma cell proliferation through protein kinase C and mitogen-activated protein kinase-dependent signaling pathways. Recent experiments demonstrate that the ET-1 axis exerts a potent antiapoptotic effect involving sphingolipid metabolism and prostaglandin-endoperoxide synthase 2/prostaglandin system in the rat Eker leiomyoma tumor-derived ELT3 cell line. Evidence supports that steroid hormones, growth factors, and extracellular matrix are key regulators of the leiomyoma growth. Interestingly, the ET-1 axis is under steroid hormones and can cooperate with these growth factors. Therefore, ET-1 alone or in association with these factors could contribute to the complex regulation of uterine tumor growth, such as proliferation, survival, and extracellular matrix production. This review summarizes current knowledge and emerging data on ET-1 in uterine leiomyoma pathology.
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Affiliation(s)
- Zahra Tanfin
- Université Paris-Sud-11, Centre National de la Recherche Scientifique (CNRS), Institut de Biochimie et Biophysique Moléculaire et Cellulaire, Equipe Signalisation Moléculaire et Cellulaire utérine, Orsay, France
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Besalduch N, Tomàs M, Santafé MM, Garcia N, Tomàs J, Lanuza MA. Synaptic activity-related classical protein kinase C isoform localization in the adult rat neuromuscular synapse. J Comp Neurol 2010; 518:211-28. [PMID: 19937712 DOI: 10.1002/cne.22220] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Protein kinase C (PKC) is essential for signal transduction in a variety of cells, including neurons and myocytes, and is involved in both acetylcholine release and muscle fiber contraction. Here, we demonstrate that the increases in synaptic activity by nerve stimulation couple PKC to transmitter release in the rat neuromuscular junction and increase the level of alpha, betaI, and betaII isoforms in the membrane when muscle contraction follows the stimulation. The phosphorylation activity of these classical PKCs also increases. It seems that the muscle has to contract in order to maintain or increase classical PKCs in the membrane. We use immunohistochemistry to show that PKCalpha and PKCbetaI were located in the nerve terminals, whereas PKCalpha and PKCbetaII were located in the postsynaptic and the Schwann cells. Stimulation and contraction do not change these cellular distributions, but our results show that the localization of classical PKC isoforms in the membrane is affected by synaptic activity.
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Affiliation(s)
- Núria Besalduch
- Unitat d'Histologia i Neurobiologia (UHN), Facultat de Medicina i Ciències de la Salut, Universitat Rovira i Virgili, 43201 Reus, Spain
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7
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Fomin VP, Kronbergs A, Gunst S, Tang D, Simirskii V, Hoffman M, Duncan RL. Role of Protein Kinase Cα in Regulation of [Ca2+]I and Force in Human Myometrium. Reprod Sci 2008; 16:71-9. [DOI: 10.1177/1933719108324892] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Victor P. Fomin
- Department of Biological Sciences, University of Delaware, Newark, Delaware,
| | - Andris Kronbergs
- Department of Biological Sciences, University of Delaware, Newark, Delaware
| | - Susan Gunst
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Dale Tang
- Center for Cardiovascular Sciences, Albany Medical College, Albany, New York
| | - Vladimir Simirskii
- Department of Biological Sciences, University of Delaware, Newark, Delaware
| | - Matthew Hoffman
- Department of Obstetrics and Gynecology, Christiana Hospital, Newark, Delaware
| | - Randall L. Duncan
- Department of Biological Sciences, University of Delaware, Newark, Delaware
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Yasuda K, Nakamoto T, Yasuhara M, Okada H, Nakajima T, Kanzaki H, Hori M, Ozaki H. Role of protein kinase Cbeta in rhythmic contractions of human pregnant myometrium. Reproduction 2007; 133:797-806. [PMID: 17504923 DOI: 10.1530/rep-06-0041] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
To assess the role of protein kinase Cbeta (PKCbeta) in human myometrial contractions during pregnancy, we evaluated the effect of a PKCbeta inhibitor (LY333531) on the pregnant and nonpregnant myometrial contractions and compared the level of PKCbeta in the pregnant myometrium with that in the nonpregnant myometrium. The effects of LY333531 on the myometrial contractions were examined by measuring contractile activity (frequency and amplitude). PKCbeta in human myometrium was assessed at mRNA level using real-time PCR method. The characteristics of contractile activity were different between the pregnant and the nonpregnant myometrium. The amplitude of rhythmic contractions in the preterm and term myometrium was increased 2- to 2.5-fold when compared with that in the nonpregnant myometrium, but the frequency of rhythmic contractions was decreased by about half. LY333531 (10(-6) M) reduced the increased amplitude in the preterm and term myometrium by about 50%, and the inhibitory effects of LY333531 in the pregnant myometrium were significantly greater than that in the nonpregnant myometrium (about 50 vs 25%). However, the frequency in the pregnant and nonpregnant myometrium was not influenced by LY333531. Real-time PCR revealed a significant, five- to sevenfold increase in the expression of PKCbeta mRNA in the preterm and term myometrium when compared with the nonpregnant myometrium. These findings suggest that the increased amplitude of human myometrial contractions during pregnancy is related to the increased level of PKCbeta. A PKCbeta inhibitor may reduce preterm uterine contractions and prevent preterm delivery.
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Affiliation(s)
- Katsuhiko Yasuda
- Department of Obstetrics and Gynecology, Kansai Medical University, 10-15 Fumizono-cho, Moriguchi, Osaka 570-8507, Japan.
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9
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Ozaki H, Yasuda K, Kim YS, Egawa M, Kanzaki H, Nakazawa H, Hori M, Seto M, Karaki H. Possible role of the protein kinase C/CPI-17 pathway in the augmented contraction of human myometrium after gestation. Br J Pharmacol 2003; 140:1303-12. [PMID: 14581181 PMCID: PMC1574139 DOI: 10.1038/sj.bjp.0705552] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
1. Activation of protein kinase C (PKC) by phorbol 12,13-dibutylate (PDBu, 1 microm) induced sustained contractions with no increase in [Ca2+]i in nonpregnant and pregnant human myometria. The contractile effects of PDBu in pregnant myometrium were much greater than those in nonpregnant myometrium, and the contractions in pregnant myometrium were accompanied by an increase in myosin light chain (MLC) phosphorylation at Ser19. 2. The contraction induced by PDBu in pregnant myometrium was inhibited by the inhibitors of conventional PKC isoforms, bisindolylmaleimides and indolocarbazole, such as Go6976, Go6983, and Go6850 (1 microM). LY333531 (1 microM), a specific inhibitor of PKC beta, also inhibited the PDBu-induced contraction in the pregnant myometrium. 3. In the pregnant myometrium permeabilized with alpha-toxin, PDBu increased the contractions induced at fixed Ca2+ concentration (0.3 microM) both in nonpregnant and pregnant myometria, indicating Ca2+ sensitization of contractile elements. 4. Western immunoblot analysis indicated that pregnant myometrium contained PKC isozymes such as conventional PKC (alpha, beta, gamma), novel PKC (delta, epsilon, theta), and atypical PKC (zeta but not iota and lambda). RT-PCR and real-time RT-PCR analysis indicated that, among the conventional PKC, the levels of mRNA of beta isoform in pregnant human myometrium were greater than those in nonpregnant myometrium. 5. CPI-17 is a substrate for PKC, and the phosphorylated CPI-17 is considered to inhibit myosin phosphatase. The levels of CPI-17 mRNA and protein expression were also greater in the pregnant myometrium. 6. These results suggest that the PKC-mediated contractile mechanism is augmented in human myometrium after gestation, and that this augmentation may be attributable to the increased activity of the beta PKC isoform and CPI-17.
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Affiliation(s)
- Hiroshi Ozaki
- Department of Veterinary Pharmacology, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Bunkyo-ku, Yayoi 1-1-1, Tokyo 113-8657, Japan.
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10
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Kim B, Kim YS, Ahn J, Kim J, Cho S, Won KJ, Ozaki H, Karaki H, Lee SM. Conventional-type protein kinase C contributes to phorbol ester-induced inhibition of rat myometrial tension. Br J Pharmacol 2003; 139:408-14. [PMID: 12770946 PMCID: PMC1573838 DOI: 10.1038/sj.bjp.0705237] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
1 Phorbol ester decreases muscle tension in the rat myometrium, and the effect is more potent in late-pregnant myometrium than in nonpregnant myometrium. In the present study, we have examined the contribution of protein kinase C (PKC) isoforms to the phorbol ester-induced inhibition of tension in rat uterine smooth muscle. 2 Thymeleatoxin (THX), a selective activator of conventional-type PKC (cPKC), and 12-deoxyphorbol 13-isobutyrate (DPB), an activator of pan PKC, inhibited the tension induced by high K(+), and inhibitions were significantly increased in pregnant myometrium compared to nonpregnant myometrium. The inhibition by DPB and THX of high K(+)-induced tension was significantly attenuated when PKC was downregulated by long-term pretreatment with THX and inhibited by Go6976, a cPKC inhibitor. 3 Of the cPKCs, PKC alpha is predominantly expressed in the rat myometrium, as detected by Western blot analysis. The expression of PKC alpha gradually increases from the beginning of gestation, reaching a maximum at day 21 of pregnancy. Treatment with DPB induced PKC alpha to translocate from the cytosol to the membrane in the pregnant myometrium. PKC epsilon and PKC zeta, other dominant PKC isoforms in the rat myometrium, decrease during gestation, reaching a minimum in late pregnancy. 4 These results suggest that cPKC may be at least partly involved in the PKC-mediated inhibition of muscle tension in the rat myometrium.
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Affiliation(s)
- Bokyung Kim
- Department of Physiology, College of Medicine, Konkuk University, Danwol-dong 322, Choongju 380-701, Korea.
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Breuiller-Fouché M, Eude I, Ferré F. Functional divergences of PKC isoforms in the human myometrium? Am J Obstet Gynecol 2001; 185:778-9. [PMID: 11568819 DOI: 10.1067/mob.2001.117479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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12
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Hurd WW, Fomin VM, Natarajan V. Reply. Am J Obstet Gynecol 2001. [DOI: 10.1067/mob.2001.117478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Eude I, Paris B, Cabrol D, Ferré F, Breuiller-Fouché M. Selective protein kinase C isoforms are involved in endothelin-1-induced human uterine contraction at the end of pregnancy. Biol Reprod 2000; 63:1567-73. [PMID: 11058567 DOI: 10.1095/biolreprod63.5.1567] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
The role of protein kinase C (PKC) in contraction of the human myometrium induced by endothelin-1 (ET-1) was investigated at the end of pregnancy. The expression and subcellular distribution of PKC isoforms were examined by Western blot analysis using isoform-specific antibodies. At least three conventional PKC isoforms (cPKC; alpha, beta1, and beta2), two novel PKC isoforms (epsilon and delta), and an atypical PKC isoform (zeta) were detected in pregnant myometrium. Quantitative immunoblotting revealed that all these isoforms were mainly distributed in the particulate fraction. The lack of a calcium chelator to modify the particulate sequestration of cPKC suggests an interaction with an anchoring protein such as receptor-activated C kinase-1, which is evidenced in the particulate fraction of the pregnant myometrium. Of the six isoforms, only PKCbeta1, PKCbeta2, PKCdelta, and PKCzeta were translocated to the particulate fraction, and PKCepsilon to the cytoskeletal fraction, after stimulation with ET-1. Involvement of PKC in the ET-1-induced contractile response is supported by the inhibition caused by the PKC inhibitor calphostin C. However, we demonstrated that the selective cPKC isoform inhibitor, Gö 6976, as well as the substantial depletion of PKCbeta1 and PKCepsilon and the partial depletion of PKCalpha and PKCdelta by a long-term treatment with phorbol 12,13-dibutyrate did not prevent ET-1-induced contraction. Accordingly, our results suggest that PKCdelta and PKCzeta activation mediated ET-1-induced contraction, whereas cPKC isoforms were not implicated in the human pregnant myometrium.
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Affiliation(s)
- I Eude
- Institut National de la Santé et de la Recherche Médicale, 75014 Paris, France
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14
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Taggart MJ, Lee YH, Morgan KG. Cellular redistribution of PKCalpha, rhoA, and ROKalpha following smooth muscle agonist stimulation. Exp Cell Res 1999; 251:92-101. [PMID: 10438574 DOI: 10.1006/excr.1999.4565] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Efficient receptor-coupled activation of smooth muscle requires discrete coordination of many signal transducing events from the plasma membrane to the myofilaments. Recruitment of key factors to the plasma membrane is thought to be crucial for transduction of extracellular signals leading to contractility. We investigated, therefore, for the first time in intact differentiated smooth muscle cells, the distributions of three molecules important for receptor-coupled excitation: protein kinase Calpha (PKCalpha), rhoA, and rho kinase (ROK). We also directly confirmed, by single cell force measurements, carbachol-induced [Ca(2+)](i) sensitization of contractility. Laser scanning confocal immunofluorescent microscopy of central smooth muscle cell sections determined that, at rest, PKCalpha, rhoA, and ROKalpha were distributed predominantly throughout the cytosol. Muscarinic stimulation resulted in significant redistribution of each protein to the cell membrane. By digital image analysis, peripheral:cytosolic distributions of PKCalpha, rhoA, and ROKalpha were calculated as, respectively, 1.05 +/- 0.03 (8), 1.09 +/- 0.03 (5), and 1.26 +/- 0.04 (12) at rest, increasing significantly following stimulation to 2.09 +/- 0.22 (6), 2.02 +/- 0.12 (8), and 1.93 +/- 0.05 (10). It is proposed that this receptor-coupled recruitment to the cell periphery of the downstream signaling molecules PKCalpha, rhoA, and ROKalpha contributes to the efficacy of agonist-induced contractile activation of smooth muscle.
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Affiliation(s)
- M J Taggart
- Signal Transduction Group, Boston Biomedical Research Institute, Boston, Massachusets, USA.
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Tertrin-Clary C, Eude I, Fournier T, Paris B, Breuiller-Fouché M, Ferré F. Contribution of protein kinase C to ET-1-induced proliferation in human myometrial cells. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 276:E503-11. [PMID: 10070017 DOI: 10.1152/ajpendo.1999.276.3.e503] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The role of protein kinase C (PKC) in endothelin-1 (ET-1)-induced proliferation of human myometrial cells was investigated. ET-1 dose dependently stimulated DNA synthesis and the number of cultured myometrial cells. Inhibition of PKC by calphostin C or Ro-31-8220 or downregulation of PKC eliminated the proliferative effects of ET-1. The failure of two protein tyrosine kinase (PTK) inhibitors (tyrphostin 51 and tyrphostin 23) to affect ET-1-induced proliferation supports the hypothesis of noninvolvement of the tyrosine kinase signaling pathway in this process. The expression and distribution of PKC isoforms were examined by Western blot analysis. The five PKC isoforms (PKC-alpha, -beta1, -beta2, -zeta, -epsilon) evidenced in human myometrial tissue were found to be differentially expressed in myometrial cells, with a predominant expression of PKC-alpha and PKC-zeta. Treatment with phorbol 12, 13-dibutyrate (PDBu) resulted in the translocation of all five isoforms to the particulate fraction, whereas ET-1 induced a selective increase in particulate PKC-beta1, PKC-beta2, and PKC-epsilon. Our findings that multiple PKC isoforms are differentially responsive to ET-1 or PDBu suggest that they play distinct roles in the myometrial growth process.
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Affiliation(s)
- C Tertrin-Clary
- Institut National de la Santé et de la Recherche Médicale Unité 361, Université René Descartes, 75014 Paris, France
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