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Goutas D, Hayenne P, Tirode F, Pissaloux D, Yeh I, de la Fouchardiere A. Smooth muscle hyperplasia in protein kinase C-fused blue naevi: Report of 12 cases. Histopathology 2024; 85:347-352. [PMID: 38747196 DOI: 10.1111/his.15211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 04/23/2024] [Accepted: 04/25/2024] [Indexed: 07/16/2024]
Abstract
BACKGROUND AND AIMS PKC-fused blue naevi are a recently described group of melanocytic tumours that have distinctive morphological features, including a pigmented epithelioid melanocytoma-like junctional component or a dermal biphasic architecture associating with naevocytoid nests surrounded by dendritic and spindled pigmented melanocytes (so-called 'combined common and blue naevus'). There have been reports of smooth muscle hyperplasia in a hamartoma-like pattern in cases of combined blue naevi without genetic exploration. MATERIALS AND METHODS Herein, we describe 12 cases of protein kinase C (PKC)-fused blue tumours associated with a co-existing smooth muscle hyperplasia, identified from a total of 98 PKC-fused melanocytic tumours. Archived slides of PKC-fused blue naevi with haematoxylin, eosin and phloxin staining, immunohistochemistry and molecular confirmation of a PKC-fusion by fluorescence in-situ hybridisation (FISH) or RNAseq were re-evaluated for identification of notable smooth muscle hyperplasia. Fifty-one of these slides had already been studied in a previous publication from our group. RESULTS The hyperplasia ranged from hypertrophic arrector pili muscles to extensive horizontal bundles of disorganised fibres constantly associated and limited within a biphasic dermal melanocytic component. At least one arrector pili muscle was always visible within the tumour, with occasionally direct extension of the hyperplastic fibres from the main muscle body. These muscle fibres were devoid of a PKC-fusion signal by FISH. PKC molecules are involved in the regulation of smooth muscle function, offering an explanatory framework. CONCLUSIONS These data suggest incorporating smooth muscle hyperplasia as a diagnostic morphological feature of PKC-fused blue melanocytic tumours.
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Affiliation(s)
- Dimitrios Goutas
- First Department of Pathology, School of Medicine, The National and Kapodistrian University of Athens, Athens, Greece
| | - Pauline Hayenne
- Centre Léon Bérard, Cancer Research Center of Lyon, Equipe Labellisée Ligue contre le Cancer, Université de Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - Franck Tirode
- Centre Léon Bérard, Cancer Research Center of Lyon, Equipe Labellisée Ligue contre le Cancer, Université de Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - Daniel Pissaloux
- Centre Léon Bérard, Cancer Research Center of Lyon, Equipe Labellisée Ligue contre le Cancer, Université de Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - Iwei Yeh
- Department of Dermatology, University of California, San Francisco, CA, USA
- Department of Pathology, University of California, San Francisco, CA, USA
| | - Arnaud de la Fouchardiere
- Centre Léon Bérard, Cancer Research Center of Lyon, Equipe Labellisée Ligue contre le Cancer, Université de Lyon, Université Claude Bernard Lyon 1, Lyon, France
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Genetic variation associated with preterm birth in African-American women. Am J Obstet Gynecol 2016; 215:235.e1-8. [PMID: 26979631 DOI: 10.1016/j.ajog.2016.03.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 03/01/2016] [Accepted: 03/07/2016] [Indexed: 11/21/2022]
Abstract
BACKGROUND Preterm birth is considered a multifactorial condition; however, emerging evidence suggests that genetic variation among individuals may have an important role. Prior studies have suggested that single-nucleotide polymorphisms associated with genes related to the immune system, and particularly the maternal inflammatory response, may be associated with an increased risk of preterm delivery. OBJECTIVE The objective of the study was to identify single-nucleotide polymorphisms associated with spontaneous preterm birth <37 weeks within a cohort of African-American women. STUDY DESIGN This is a secondary analysis of a randomized trial that evaluated periodontal disease and preterm birth. Women were enrolled between 6 and 20 weeks' gestation at 3 prenatal care clinics between 2004 and 2007. Maternal DNA samples were collected and analyzed using a custom 1536 single-nucleotide polymorphismgenotyping array designed to assess genes involved in inflammation. Women were included in this study if they self-identified as African American. We excluded women with a multiple gestation or an indicated preterm delivery. We performed allele- and genotype-based analyses to evaluate the association between spontaneous preterm birth and tag single-nucleotide polymorphisms. We used a logistic regression to adjust for prior preterm birth in our genotype-based analysis. In a subgroup analysis, we compared women who delivered at <34 weeks' gestation to women who delivered at term. Within the microarray, we identified ancestry informative markers and compared global ancestry estimates among women who delivered preterm with those who delivered at term. RESULTS Of the 833 African-American women in the study with genotype data, 77 women (9.2%) had a spontaneous preterm birth, whereas 756 women delivered at term. In an allele-based analysis, 4 single-nucleotide polymorphisms related to the genes for protein kinase C-α (PRKCA) were associated with increased risk of spontaneous preterm birth <37 weeks, whereas a single single-nucleotide polymorphism related to fms-related tyrosine kinase 1 (FLT1) was associated with spontaneous preterm birth <34 weeks. A genotype-based analysis revealed similar associations between single-nucleotide polymorphisms related to the PRKCA genes and spontaneous premature delivery. Additionally, single-nucleotide polymorphisms related to matrix metalloproteinase-2 (MMP2), tissue inhibitor of matrix metalloproteinase-2 (TIMP2), and interleukin 16 (IL16) genes were associated with spontaneous preterm birth <37 weeks in genotype-based analysis. Genetic variants related to MMP2, matrix metalloproteinase-1 (MMP1), and leukemia inhibitory factor receptor antisense RNA 1 (LIFR-AS1) genes were associated with higher rates of preterm birth <34 weeks. Ancestry estimates were similar between the women who had a spontaneous preterm birth and those who delivered at term. CONCLUSION We identified tag single-nucleotide polymorphisms related to 7 genes that are critical to inflammation, extracellular remodeling, and cell signaling that were associated with spontaneous preterm birth in African-American women. Specifically, we found a strong association with the PRKCA gene. Genetic variation in these regions of the genome may be important in the pathogenesis of preterm birth. Our results should be considered in the design of future genomic studies in prematurity.
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Arrigo AP, Ducarouge B, Lavial F, Gibert B. Immense Cellular Implications Associated to Small Stress Proteins Expression: Impacts on Human Pathologies. HEAT SHOCK PROTEINS 2015. [DOI: 10.1007/978-3-319-16077-1_2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Arrigo AP, Gibert B. HspB1, HspB5 and HspB4 in Human Cancers: Potent Oncogenic Role of Some of Their Client Proteins. Cancers (Basel) 2014; 6:333-65. [PMID: 24514166 PMCID: PMC3980596 DOI: 10.3390/cancers6010333] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Revised: 01/03/2014] [Accepted: 01/17/2014] [Indexed: 12/20/2022] Open
Abstract
Human small heat shock proteins are molecular chaperones that regulate fundamental cellular processes in normal unstressed cells as well as in many cancer cells where they are over-expressed. These proteins are characterized by cell physiology dependent changes in their oligomerization and phosphorylation status. These structural changes allow them to interact with many different client proteins that subsequently display modified activity and/or half-life. Nowdays, the protein interactomes of small Hsps are under intense investigations and will represent, when completed, key parameters to elaborate therapeutic strategies aimed at modulating the functions of these chaperones. Here, we have analyzed the potential pro-cancerous roles of several client proteins that have been described so far to interact with HspB1 (Hsp27) and its close members HspB5 (αB-crystallin) and HspB4 (αA-crystallin).
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Affiliation(s)
- André-Patrick Arrigo
- Apoptosis, Cancer and Development Laboratory, Lyon Cancer Research Center, INSERM U1052-CNRS UMR5286, Claude Bernard University Lyon 1, Lyon 69008, France.
| | - Benjamin Gibert
- Apoptosis, Cancer and Development Laboratory, Lyon Cancer Research Center, INSERM U1052-CNRS UMR5286, Claude Bernard University Lyon 1, Lyon 69008, France.
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Arrigo AP, Gibert B. Protein interactomes of three stress inducible small heat shock proteins: HspB1, HspB5 and HspB8. Int J Hyperthermia 2013; 29:409-22. [DOI: 10.3109/02656736.2013.792956] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
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Arrigo AP. Human small heat shock proteins: Protein interactomes of homo- and hetero-oligomeric complexes: An update. FEBS Lett 2013; 587:1959-69. [DOI: 10.1016/j.febslet.2013.05.011] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Revised: 05/02/2013] [Accepted: 05/02/2013] [Indexed: 10/26/2022]
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Seit-Nebi AS, Datskevich P, Gusev NB. Commentary on paper: Small heat shock proteins and the cytoskeleton: An essential interplay for cell integrity? (Wettstein et al.). Int J Biochem Cell Biol 2013. [DOI: 10.1016/j.biocel.2012.11.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Ciocca DR, Arrigo AP, Calderwood SK. Heat shock proteins and heat shock factor 1 in carcinogenesis and tumor development: an update. Arch Toxicol 2012; 87:19-48. [PMID: 22885793 DOI: 10.1007/s00204-012-0918-z] [Citation(s) in RCA: 194] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Accepted: 07/25/2012] [Indexed: 12/20/2022]
Abstract
Heat shock proteins (HSP) are a subset of the molecular chaperones, best known for their rapid and abundant induction by stress. HSP genes are activated at the transcriptional level by heat shock transcription factor 1 (HSF1). During the progression of many types of cancer, this heat shock transcriptional regulon becomes co-opted by mechanisms that are currently unclear, although evidently triggered in the emerging tumor cell. Concerted activation of HSF1 and the accumulation of HSPs then participate in many of the traits that permit the malignant phenotype. Thus, cancers of many histologies exhibit activated HSF1 and increased HSP levels that may help to deter tumor suppression and evade therapy in the clinic. We review here the extensive work that has been carried out and is still in progress aimed at (1) understanding the oncogenic mechanisms by which HSP genes are switched on, (2) determining the roles of HSF1/HSP in malignant transformation and (3) discovering approaches to therapy based on disrupting the influence of the HSF1-controlled transcriptome in cancer.
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Affiliation(s)
- Daniel R Ciocca
- Oncology Laboratory, Institute of Experimental Medicine and Biology of Cuyo (IMBECU), Scientific and Technological Center (CCT), CONICET, 5500 Mendoza, Argentina.
| | - Andre Patrick Arrigo
- Apoptosis Cancer and Development, Cancer Research Center of Lyon (CRCL), UMR INSERM 1052-CNRS 5286, Claude Bernard University, Lyon-1, Cheney A Building, Centre Regional Léon Bérard, 28, rue Laennec 69008 LYON, France. ;
| | - Stuart K Calderwood
- Molecular and Cellular Radiation Oncology, Department of Radiation Oncology, Beth Israel Deaconess Medical Center, Boston, MA02215
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Tojkander S, Gateva G, Lappalainen P. Actin stress fibers--assembly, dynamics and biological roles. J Cell Sci 2012; 125:1855-64. [PMID: 22544950 DOI: 10.1242/jcs.098087] [Citation(s) in RCA: 515] [Impact Index Per Article: 42.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Actin filaments assemble into diverse protrusive and contractile structures to provide force for a number of vital cellular processes. Stress fibers are contractile actomyosin bundles found in many cultured non-muscle cells, where they have a central role in cell adhesion and morphogenesis. Focal-adhesion-anchored stress fibers also have an important role in mechanotransduction. In animal tissues, stress fibers are especially abundant in endothelial cells, myofibroblasts and epithelial cells. Importantly, recent live-cell imaging studies have provided new information regarding the mechanisms of stress fiber assembly and how their contractility is regulated in cells. In addition, these studies might elucidate the general mechanisms by which contractile actomyosin arrays, including muscle cell myofibrils and cytokinetic contractile ring, can be generated in cells. In this Commentary, we discuss recent findings concerning the physiological roles of stress fibers and the mechanism by which these structures are generated in cells.
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Affiliation(s)
- Sari Tojkander
- Institute of Biotechnology, University of Helsinki, Finland
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Somara S, Bitar KN. Direct association of calponin with specific domains of PKC-alpha. Am J Physiol Gastrointest Liver Physiol 2008; 295:G1246-54. [PMID: 18948438 PMCID: PMC2604804 DOI: 10.1152/ajpgi.90461.2008] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2008] [Accepted: 10/17/2008] [Indexed: 01/31/2023]
Abstract
Calponin contributes to the regulation of smooth muscle contraction through its interaction with F-actin and inhibition of the actin-activated Mg-ATPase activity of phosphorylated myosin. Previous studies have shown that the contractile agonist acetylcholine induced a direct association of translocated calponin and PKC-alpha in the membrane. In the present study, we have determined the domain of PKC-alpha involved in direct association with calponin. In vitro binding assay was carried out by incubating glutathione S-transferase-calponin aa 92-229 with His-tagged proteins of individual domains and different combinations of domains of PKC-alpha. Calponin was found to bind directly to the full-length PKC-alpha. Calponin bound to C2 and C4 domains but not to C1 and C3 domains of PKC-alpha. When incubated with proteins of different combination of domains, calponin bound to C2-C3, C3-C4, and C2-C3-C4 but not to C1-C2 or C1-C2-C3. To determine whether these in vitro bindings mimic the in vivo associations, and in vivo binding assay was performed by transfecting colonic smooth muscle cells with His-tagged proteins of individual domains and different combinations of domains of PKC-alpha. Coimmunoprecipitation of calponin with His-tagged truncated forms of PKC-alpha showed that C1-C2, C1-C2-C3, C2-C3, and C3-C4 did not associate with calponin. Calponin associated only with full-length PKC-alpha and with C2-C3-C4 in cells in the resting state, and this association increased upon stimulation with acetylcholine. These data suggest that calponin bound to fragments that may mimic the active form of PKC-alpha and that the functional association of PKC-alpha with calponin requires both C2 and C4 domains during contraction of colonic smooth muscle cells.
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Affiliation(s)
- Sita Somara
- Division of Pediatrics-Gastroenterology, University of Michigan Medical Center, Ann Arbor, MI 48109-5656, USA
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11
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Salinthone S, Tyagi M, Gerthoffer WT. Small heat shock proteins in smooth muscle. Pharmacol Ther 2008; 119:44-54. [PMID: 18579210 DOI: 10.1016/j.pharmthera.2008.04.005] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2008] [Accepted: 04/28/2008] [Indexed: 01/16/2023]
Abstract
The small heat shock proteins (HSPs) HSP20, HSP27 and alphaB-crystallin are chaperone proteins that are abundantly expressed in smooth muscles are important modulators of muscle contraction, cell migration and cell survival. This review focuses on factors regulating expression of small HSPs in smooth muscle, signaling pathways that regulate macromolecular structure and the biochemical and cellular functions of small HSPs. Cellular processes regulated by small HSPs include chaperoning denatured proteins, maintaining cellular redox state and modifying filamentous actin polymerization. These processes influence smooth muscle proliferation, cell migration, cell survival, muscle contraction and synthesis of signaling proteins. Understanding functions of small heat shock proteins is relevant to mechanisms of disease in which dysfunctional smooth muscle causes symptoms, or is a target of drug therapy. One example is that secreted HSP27 may be a useful marker of inflammation during atherogenesis. Another is that phosphorylated HSP20 which relaxes smooth muscle may prove to be highly relevant to treatment of hypertension, vasospasm, asthma, premature labor and overactive bladder. Because small HSPs also modulate smooth muscle proliferation and cell migration they may prove to be targets for developing effective, novel treatments of clinical problems arising from remodeling of smooth muscle in vascular, respiratory and urogenital systems.
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Affiliation(s)
- Sonemany Salinthone
- Department of Neurology, Oregon Health Sciences University, Portland, OR, USA
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Liu XJ, Yang C, Gupta N, Zuo J, Chang YS, Fang FD. Protein kinase C-zeta regulation of GLUT4 translocation through actin remodeling in CHO cells. J Mol Med (Berl) 2007; 85:851-61. [PMID: 17619838 DOI: 10.1007/s00109-007-0232-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2007] [Revised: 04/25/2007] [Accepted: 05/31/2007] [Indexed: 01/08/2023]
Abstract
Actin remodeling plays a crucial role in insulin-induced translocation of glucose transporter 4 (GLUT4) from the cytoplasm to the plasma membrane and subsequent glucose transport. Protein kinase C (PKC) zeta has been implicated in this translocation process, although the exact mechanism remains unknown. In this study, we investigated the effect of PKCzeta on actin cytoskeleton and translocation of GLUT4 in CHO-K1 cells expressing myc-tagged GLUT4. Insulin stimulated the phosphorylation of PKCzeta at Thr410 with no apparent effect on its protein expression. Moreover, insulin promoted colocalization of PKCzeta and actin that could be abolished by Latrunculin B. The overexpression of PKCzeta mimicked the insulin-induced change in actin cytoskeleton and translocation of GLUT4. These effects were also completely abrogated by Latrunculin B treatment. Using cell-permeable pseudosubstrate (PS) inhibitor of PKCzeta, the response to insulin could be alleviated. Our results strongly suggest that PKCzeta mediates the stimulatory effect of insulin on GLUT4 translocation through its interaction with actin cytoskeleton.
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Affiliation(s)
- Xiao-Jun Liu
- National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & School of Basic Medicine Peking Union Medical College, Beijing, China
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Ferjani I, Fattoum A, Maciver SK, Manai M, Benyamin Y, Roustan C. Two distinct sites of interaction form the calponin: gelsolin complex and two calcium switches control its activity. BIOCHIMICA ET BIOPHYSICA ACTA 2007; 1774:952-8. [PMID: 17556051 DOI: 10.1016/j.bbapap.2007.04.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2007] [Revised: 04/25/2007] [Accepted: 04/27/2007] [Indexed: 10/23/2022]
Abstract
Gelsolin and calponin are well characterized actin-binding proteins that form a tight gelsolin:calponin complex (GCC). We show here that the GCC is formed through two distinct interfaces. One of these is formed between 144-182 of calponin and 25-150 of gelsolin (G1). The second is a calcium-sensitive site centred on calponin's CH domain, and the C-terminal half of gelsolin (G4-6). The behaviour of this second interface is dependent on the presence of calcium and so it is possible that potential GCC-binding partners may be selected by calcium availability. Actin is one such GCC-binding partner and we show that a larger complex is formed with monomeric actin in calcium. The stoichiometry of this complex is determined to be 1 gelsolin/1 calponin/2 G-actins (GCA(2)). Both actin monomers bind the GCC through gelsolin. Both calponin and gelsolin are reported to play signaling roles in addition to their better-characterized actin-binding properties and it is possible that the GCC regulates both of these functions.
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Affiliation(s)
- Imen Ferjani
- DIMNP, University of Montpellier 2 and 1, CNRS Montpellier, Place E, Bataillon, CC107, 34095 Montpellier Cedex 5, France
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Poole DP, Furness JB. PKC delta-isoform translocation and enhancement of tonic contractions of gastrointestinal smooth muscle. Am J Physiol Gastrointest Liver Physiol 2007; 292:G887-98. [PMID: 17158259 DOI: 10.1152/ajpgi.00222.2006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
PKC is involved in mediating the tonic component of gastrointestinal smooth muscle contraction in response to stimulation by agonists for G protein-coupled receptors. Here, we present pharmacological and immunohistochemical evidence indicating that a member of the novel PKC isoforms, PKC-delta, is involved in maintaining muscarinic receptor-coupled tonic contractions of the guinea pig ileum. The tonic component of carbachol-evoked contractions was enhanced by an activator of conventional and novel PKCs, phorbol 12,13-dibutyrate (PDBu; 200 nM or 1 microM), and by an activator of novel PKCs, ingenol 3,20-dibenzoate (IDB; 100 or 500 nM). Enhancement was unaffected by concentrations of bisindolylmaleimide I (BIM-I; 22 nM) that block conventional PKCs or by a PKC-epsilon-specific inhibitor peptide but was attenuated by higher doses of BIM-I (2.2 microM). Relevant proteins were localized at a cellular and subcellular level using confocal analysis. Immunohistochemical staining of the ileum showed that PKC-delta was exclusively expressed in smooth muscles distributed throughout the layers of the gut wall. PKC-epsilon immunoreactivity was prominent in enteric neurons but was largely absent from smooth muscle of the muscularis externa. Treatment with PDBu, IDB, or carbachol resulted in a time- and concentration-dependent translocation of PKC-delta from the cytoplasm to filamentous structures within smooth muscle cells. These were parallel to, but distinct from, actin filaments. The translocation of PKC-delta in response to carbachol was significantly reduced by scopolamine or calphostin C. The present study indicates that the tonic carbachol-induced contraction of the guinea pig ileum is mediated through a novel PKC, probably PKC-delta.
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Affiliation(s)
- Daniel P Poole
- Department of Anatomy and Cell Biology, University of Melbourne, Parkville, Victoria 3010, Australia.
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Dykes AC, Wright GL. Down-regulation of calponin destabilizes actin cytoskeletal structure in A7r5 cells. Can J Physiol Pharmacol 2007; 85:225-32. [PMID: 17487264 DOI: 10.1139/y07-005] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The effects of changes in the expression levels of h1 calponin (CaP) on actin cytoskeletal organization were studied in control and phorbol-ester-treated A7r5 smooth muscle cells. Protein association and expression in control and stimulated A7r5 smooth muscle cells were evaluated by Western blotting, laser scanning confocal microscopy (LSCM), and fluorescence resonance energy transfer (FRET) microscopy in cells treated with either 2 x 10(-6 ) mol/L TGF-beta 1 or 2 x 10(-)5 mol/L PDGF-BB to alter h1 calponin expression. Single immunostained samples showed that CaP and alpha-actin, localized in fibers in unstimulated control A7r5 smooth muscle cells, were translocated to podosomes following treatment with phorbol-12,13-dibutyrate (PDBu). Confocal colocalization imaging and FRET analysis both indicated substantial association of CaP with alpha-actin in stress fibers of control cells and in podosomes of PDBu-treated cells. PKC alpha, which showed evidence of only slight association with CaP in control cells, exhibited markedly increased (293%) association in PDBu-contracted cells. Platelet-derived growth factor (PDGF)-BB down-regulated CaP to non-detectable levels, whereas transforming growth factor (TGF)-beta 1 up-regulated (424%) the expression of CaP without affecting the levels of alpha-actin or PKC alpha. PDGF-BB resulted in a significant loss in alpha-actin stress fibers (-47%) and reduced podosome formation (-69%). By comparison, TGF-beta 1 had no effect on stress fibers in control cells but also reduced (-70%) podosome formation. The results suggest that CaP could play a major role in the stabilization of actin stress fibers in resting cells and may contribute to podosome formation in PDBu-treated cells.
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Affiliation(s)
- Ava C Dykes
- The Joan C. Edwards School of Medicine, Marshall University, 1542 Spring Valley Drive, Huntington, WV 25704, USA
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Ferjani I, Fattoum A, Maciver SK, Manai M, Benyamin Y, Roustan C. Calponin binds G-actin and F-actin with similar affinity. FEBS Lett 2006; 580:4801-6. [PMID: 16901482 DOI: 10.1016/j.febslet.2006.07.065] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2006] [Revised: 06/30/2006] [Accepted: 07/24/2006] [Indexed: 10/24/2022]
Abstract
Calponins are actin-binding proteins that are implicated in the regulation of actomyosin. Calponin binds filamentous actin (F-actin) through two distinct sites ABS1 and ABS2, with an affinity in the low micromolar range. We report that smooth muscle calponin binds monomeric actin with a similar affinity (K(d) of 0.15 microM). We show that the arrangement of binding is similar to that of F-actin by a number of criteria, most notably that the distance between Cys273 on calponin and Cys374 of actin is 29A when measured by fluorescent resonance energy transfer, the same distance as previously reported for F-actin.
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Affiliation(s)
- Imen Ferjani
- UMR 5539 (CNRS) Laboratoire de motilité cellulaire (Ecole Pratique des Hautes Etudes) Université de Montpellier 2, Place E. Bataillon, CC107, 34095 Montpellier Cedex 5, France
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Ferjani I, Fattoum A, Maciver S, Bénistant C, Chahinian A, Manai M, Benyamin Y, Roustan C. A direct interaction with calponin inhibits the actin-nucleating activity of gelsolin. Biochem J 2006; 396:461-8. [PMID: 16536729 PMCID: PMC1482823 DOI: 10.1042/bj20051690] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2005] [Revised: 03/02/2006] [Accepted: 03/15/2006] [Indexed: 12/26/2022]
Abstract
Gelsolin and calponin are well-characterized cytoskeletal proteins that are abundant and widely expressed in vertebrate tissues. It is also becoming apparent, however, that they are involved in cell signalling. In the present study, we show that gelsolin and calponin interact directly to form a high-affinity (K(d)=16 nM) 1:1 complex, by the use of fluorescent probes attached to both proteins, by affinity chromatography and by immunoprecipitation. These methods show that gelsolin can form high-affinity complexes with two calponin isoforms (basic h1 and acidic h3). They also show that gelsolin binds calponin through regions that have been identified previously as being calponin's actin-binding sites. Moreover, gelsolin does not interact with calponin while calponin is bound to F-actin. Reciprocal experiments to find calponin-binding sites on gelsolin show that these are in both the N- and C-terminal halves of gelsolin. Calponin has minimal effects on actin severing by gelsolin. In contrast, calponin markedly affects the nucleation activity of gelsolin. The maximum inhibition of nucleation by gelsolin was 50%, which was achieved with a ratio of two calponins for every gelsolin. Thus the interaction of calponin with gelsolin may play a regulatory role in the formation of actin filaments through modulation of gelsolin's actin-binding function and through the prevention of calponin's actin-binding activities.
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Affiliation(s)
- Imen Ferjani
- *UMR 5539 (CNRS) Laboratoire de Motilité Cellulaire (Ecole Pratique des Hautes Etudes), Université de Montpellier 2, Place E. Bataillon, CC107, 34095 Montpellier Cedex 5, France
- †Unité de Biochimie et Biololgie Moléculaire, Faculté des Sciences de Tunis, Campus Universitaire 2092 El Manar, Tunis, Tunisia
| | - Abdellatif Fattoum
- ‡School of Biomedical and Clinical Laboratory Sciences, Division of Biomedical Sciences, College of Medicine, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, Scotland
| | - Sutherland K. Maciver
- §Centre de Recherches de Biochimie Macromoléculaire, FRE 2593 (CNRS), 1919 rte de Mende, 34293 Montpellier Cedex 5, France
| | - Christine Bénistant
- ‡School of Biomedical and Clinical Laboratory Sciences, Division of Biomedical Sciences, College of Medicine, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, Scotland
| | - Anne Chahinian
- *UMR 5539 (CNRS) Laboratoire de Motilité Cellulaire (Ecole Pratique des Hautes Etudes), Université de Montpellier 2, Place E. Bataillon, CC107, 34095 Montpellier Cedex 5, France
| | - Mohamed Manai
- †Unité de Biochimie et Biololgie Moléculaire, Faculté des Sciences de Tunis, Campus Universitaire 2092 El Manar, Tunis, Tunisia
| | - Yves Benyamin
- *UMR 5539 (CNRS) Laboratoire de Motilité Cellulaire (Ecole Pratique des Hautes Etudes), Université de Montpellier 2, Place E. Bataillon, CC107, 34095 Montpellier Cedex 5, France
| | - Claude Roustan
- *UMR 5539 (CNRS) Laboratoire de Motilité Cellulaire (Ecole Pratique des Hautes Etudes), Université de Montpellier 2, Place E. Bataillon, CC107, 34095 Montpellier Cedex 5, France
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Somara S, Pang H, Bitar KN. Agonist-induced association of tropomyosin with protein kinase Calpha in colonic smooth muscle. Am J Physiol Gastrointest Liver Physiol 2005; 288:G268-76. [PMID: 15486343 DOI: 10.1152/ajpgi.00330.2004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Smooth muscle contraction regulated by myosin light chain phosphorylation is also regulated at the thin-filament level. Tropomyosin, a thin-filament regulatory protein, regulates contraction by modulating actin-myosin interactions. Present investigation shows that acetylcholine induces PKC-mediated and calcium-dependent phosphorylation of tropomyosin in colonic smooth muscle cells. Our data also shows that acetylcholine induces a significant and sustained increase in PKC-mediated association of tropomyosin with PKCalpha in the particulate fraction of colonic smooth muscle cells. Immunoblotting studies revealed that in colonic smooth muscle cells, there is no significant change in the amount of tropomyosin or actin in particulate fraction in response to acetylcholine, indicating that the increased association of tropomyosin with PKCalpha in the particulate fraction may be due to acetylcholine-induced translocation of PKCalpha to the particulate fraction. To investigate whether the association of PKCalpha with tropomyosin was due to a direct interaction, we performed in vitro direct binding assay. Tropomyosin cDNA amplified from colonic smooth muscle mRNA was expressed as GST-tropomyosin fusion protein. In vitro binding experiments using GST-tropomyosin and recombinant PKCalpha indicated direct interaction of tropomyosin with PKCalpha. PKC-mediated phosphorylation of tropomyosin and direct interaction of PKCalpha with tropomyosin suggest that tropomyosin could be a substrate for PKC. Phosphorylation of tropomyosin may aid in holding the slided tropomyosin away from myosin binding sites on actin, resulting in actomyosin interaction and sustained contraction.
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Affiliation(s)
- Sita Somara
- Department of Pediatrics, University of Michigan Medical School, Ann Arbor, MI 48109-0658, USA
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Kim N, Cao W, Song IS, Kim CY, Harnett KM, Cheng L, Walsh MP, Biancani P. Distinct kinases are involved in contraction of cat esophageal and lower esophageal sphincter smooth muscles. Am J Physiol Cell Physiol 2004; 287:C384-94. [PMID: 15128504 DOI: 10.1152/ajpcell.00390.2003] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Contraction of smooth muscle depends on the balance of myosin light chain kinase (MLCK) and myosin light chain phosphatase (MLCP) activities. Because MLCK activation depends on the activation of calmodulin, which requires a high Ca2+concentration, phosphatase inhibition has been invoked to explain contraction at low cytosolic Ca2+levels. The link between activation of the Ca2+-independent protein kinase Cε (PKCε) and MLC phosphorylation observed in the esophagus (ESO) (Sohn UD, Cao W, Tang DC, Stull JT, Haeberle JR, Wang CLA, Harnett KM, Behar J, and Biancani P. Am J Physiol Gastrointest Liver Physiol 281: G467–G478, 2001), however, has not been elucidated. We used phosphatase and kinase inhibitors and antibodies to signaling enzymes in combination with intact and saponin-permeabilized isolated smooth muscle cells from ESO and lower esophageal sphincter (LES) to examine PKCε-dependent, Ca2+-independent signaling in ESO. The phosphatase inhibitors okadaic acid and microcystin-LR, as well as an antibody to the catalytic subunit of type 1 protein serine/threonine phosphatase, elicited similar contractions in ESO and LES. MLCK inhibitors (ML-7, ML-9, and SM-1) and antibodies to MLCK inhibited contraction induced by phosphatase inhibition in LES but not in ESO. The PKC inhibitor chelerythrine and antibodies to PKCε, but not antibodies to PKCβII, inhibited contraction of ESO but not of LES. In ESO, okadaic acid triggered translocation of PKCε from cytosolic to particulate fraction and increased activity of integrin-linked kinase (ILK). Antibodies to the mitogen-activated protein (MAP) kinases ERK1/ERK2 and to ILK, and the MAP kinase kinase (MEK) inhibitor PD-98059, inhibited okadaic acid-induced ILK activity and contraction of ESO. We conclude that phosphatase inhibition potentiates the effects of MLCK in LES but not in ESO. Contraction of ESO is mediated by activation of PKCε, MEK, ERK1/2, and ILK.
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Affiliation(s)
- Nayoung Kim
- Department of Medicine, Seoul National University, Bundang Hospital, Seoungnam, Gyeronggi-Do 463-707, Korea
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