1
|
Endogenous Opioids and Their Role in Stem Cell Biology and Tissue Rescue. Int J Mol Sci 2022; 23:ijms23073819. [PMID: 35409178 PMCID: PMC8998234 DOI: 10.3390/ijms23073819] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 03/28/2022] [Accepted: 03/29/2022] [Indexed: 01/25/2023] Open
Abstract
Opioids are considered the oldest drugs known by humans and have been used for sedation and pain relief for several centuries. Nowadays, endogenous opioid peptides are divided into four families: enkephalins, dynorphins, endorphins, and nociceptin/orphanin FQ. They exert their action through the opioid receptors (ORs), transmembrane proteins belonging to the super-family of G-protein-coupled receptors, and are expressed throughout the body; the receptors are the δ opioid receptor (DOR), μ opioid receptor (MOR), κ opioid receptor (KOR), and nociceptin/orphanin FQ receptor (NOP). Endogenous opioids are mainly studied in the central nervous system (CNS), but their role has been investigated in other organs, both in physiological and in pathological conditions. Here, we revise their role in stem cell (SC) biology, since these cells are a subject of great scientific interest due to their peculiar features and their involvement in cell-based therapies in regenerative medicine. In particular, we focus on endogenous opioids’ ability to modulate SC proliferation, stress response (to oxidative stress, starvation, or damage following ischemia–reperfusion), and differentiation towards different lineages, such as neurogenesis, vasculogenesis, and cardiogenesis.
Collapse
|
2
|
Canaider S, Facchin F, Tassinari R, Cavallini C, Olivi E, Taglioli V, Zannini C, Bianconi E, Maioli M, Ventura C. Intracrine Endorphinergic Systems in Modulation of Myocardial Differentiation. Int J Mol Sci 2019; 20:ijms20205175. [PMID: 31635381 PMCID: PMC6829321 DOI: 10.3390/ijms20205175] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 10/11/2019] [Accepted: 10/16/2019] [Indexed: 12/12/2022] Open
Abstract
A wide variety of peptides not only interact with the cell surface, but govern complex signaling from inside the cell. This has been referred to as an "intracrine" action, and the orchestrating molecules as "intracrines". Here, we review the intracrine action of dynorphin B, a bioactive end-product of the prodynorphin gene, on nuclear opioid receptors and nuclear protein kinase C signaling to stimulate the transcription of a gene program of cardiogenesis. The ability of intracrine dynorphin B to prime the transcription of its own coding gene in isolated nuclei is discussed as a feed-forward loop of gene expression amplification and synchronization. We describe the role of hyaluronan mixed esters of butyric and retinoic acids as synthetic intracrines, controlling prodynorphin gene expression, cardiogenesis, and cardiac repair. We also discuss the increase in prodynorphin gene transcription and intracellular dynorphin B afforded by electromagnetic fields in stem cells, as a mechanism of cardiogenic signaling and enhancement in the yield of stem cell-derived cardiomyocytes. We underline the possibility of using the diffusive features of physical energies to modulate intracrinergic systems without the needs of viral vector-mediated gene transfer technologies, and prompt the exploration of this hypothesis in the near future.
Collapse
Affiliation(s)
- Silvia Canaider
- National Laboratory of Molecular Biology and Stem Cell Bioengineering - Eldor Lab, National Institute of Biostructures and Biosystems (NIBB), at the Innovation Accelerator, CNR, Via Piero Gobetti 101, 40129 Bologna, Italy.
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Via Massarenti 9, 40138 Bologna, Italy.
| | - Federica Facchin
- National Laboratory of Molecular Biology and Stem Cell Bioengineering - Eldor Lab, National Institute of Biostructures and Biosystems (NIBB), at the Innovation Accelerator, CNR, Via Piero Gobetti 101, 40129 Bologna, Italy.
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Via Massarenti 9, 40138 Bologna, Italy.
| | - Riccardo Tassinari
- National Laboratory of Molecular Biology and Stem Cell Bioengineering - Eldor Lab, National Institute of Biostructures and Biosystems (NIBB), at the Innovation Accelerator, CNR, Via Piero Gobetti 101, 40129 Bologna, Italy.
| | - Claudia Cavallini
- National Laboratory of Molecular Biology and Stem Cell Bioengineering - Eldor Lab, National Institute of Biostructures and Biosystems (NIBB), at the Innovation Accelerator, CNR, Via Piero Gobetti 101, 40129 Bologna, Italy.
| | - Elena Olivi
- National Laboratory of Molecular Biology and Stem Cell Bioengineering - Eldor Lab, National Institute of Biostructures and Biosystems (NIBB), at the Innovation Accelerator, CNR, Via Piero Gobetti 101, 40129 Bologna, Italy.
| | - Valentina Taglioli
- National Laboratory of Molecular Biology and Stem Cell Bioengineering - Eldor Lab, National Institute of Biostructures and Biosystems (NIBB), at the Innovation Accelerator, CNR, Via Piero Gobetti 101, 40129 Bologna, Italy.
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Via Massarenti 9, 40138 Bologna, Italy.
| | - Chiara Zannini
- National Laboratory of Molecular Biology and Stem Cell Bioengineering - Eldor Lab, National Institute of Biostructures and Biosystems (NIBB), at the Innovation Accelerator, CNR, Via Piero Gobetti 101, 40129 Bologna, Italy.
| | - Eva Bianconi
- National Laboratory of Molecular Biology and Stem Cell Bioengineering - Eldor Lab, National Institute of Biostructures and Biosystems (NIBB), at the Innovation Accelerator, CNR, Via Piero Gobetti 101, 40129 Bologna, Italy.
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Via Massarenti 9, 40138 Bologna, Italy.
| | - Margherita Maioli
- Department of Biomedical Sciences, University of Sassari, Viale San Pietro 43/B, 07100 Sassari, Italy.
| | - Carlo Ventura
- National Laboratory of Molecular Biology and Stem Cell Bioengineering - Eldor Lab, National Institute of Biostructures and Biosystems (NIBB), at the Innovation Accelerator, CNR, Via Piero Gobetti 101, 40129 Bologna, Italy.
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Via Massarenti 9, 40138 Bologna, Italy.
| |
Collapse
|
3
|
Lasukova TV, Maslov LN, Gorbunov AS. Effects of μ-Opioid Receptor Agonist DAMGO on Heart Contractility and Necrotic Injury to Cardiomyocytes during Ischemia and Reperfusion of Isolated Rat Heart. Bull Exp Biol Med 2015; 159:722-5. [PMID: 26519265 DOI: 10.1007/s10517-015-3058-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Indexed: 12/01/2022]
Abstract
We studied the effects of μ-opioid receptor activation in vivo and in vitro on the tolerance of isolated perfused rat heart to global ischemia (45 min) and reperfusion (30 min). Stimulation of μ-receptors in vivo by intraperitoneal administration of μ-opioid receptor agonist DAMGO (0.1 mg/kg) reduced reperfusion release of creatinine phosphokinase and promoted aggravation of postischemic systolic and diastolic dysfunction of the isolated heart. Activation of μ-opioid receptors in vitro by addition of selective agonist DAMGO in a concentration of 170 nM to perfusion solution had no effect on necrotic death of cardiomyocytes and aggravated reperfusion stunning of the heart.
Collapse
Affiliation(s)
- T V Lasukova
- Department of Medical and Biological Disciplines, Tomsk State Pedagogical University, Tomsk, Russia. .,Laboratory of Experimental Cardiology, Research Institute of Cardiology, Tomsk, Russia.
| | - L N Maslov
- Laboratory of Experimental Cardiology, Research Institute of Cardiology, Tomsk, Russia
| | - A S Gorbunov
- Laboratory of Experimental Cardiology, Research Institute of Cardiology, Tomsk, Russia
| |
Collapse
|
4
|
Maioli M, Rinaldi S, Santaniello S, Castagna A, Pigliaru G, Gualini S, Fontani V, Ventura C. Radiofrequency energy loop primes cardiac, neuronal, and skeletal muscle differentiation in mouse embryonic stem cells: a new tool for improving tissue regeneration. Cell Transplant 2011; 21:1225-33. [PMID: 21975035 DOI: 10.3727/096368911x600966] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Radiofrequency (RF) waves from Wi-Fi (wireless fidelity) technologies have become ubiquitous, with Internet access spreading into homes, and public areas. The human body harbors multipotent stem cells with various grading of potentiality. Whether stem cells may be affected by Wi-Fi RF energy remains unknown. We exposed mouse embryonic stem (ES) cells to a Radio Electric Asymmetric Conveyer (REAC), an innovative device delivering Wi-Fi RF of 2.4 GHz with its conveyer electrodes immersed into the culture medium. Cell responses were investigated by real-time PCR, Western blot, and confocal microscopy. Single RF burst duration, radiated power, electric and magnetic fields, specific absorption rate, and current density in culture medium were monitored. REAC stimulation primed transcription of genes involved in cardiac (GATA4, Nkx-2.5, and prodynorphin), skeletal muscle (myoD) and neuronal (neurogenin1) commitment, while downregulating the self renewal/pluripotency-associated genes Sox2, Oct4, and Nanog. REAC exposure enhanced the expression of cardiac, skeletal, and neuronal lineage-restricted marker proteins. The number of spontaneously beating ES-derived myocardial cells was also increased. In conclusion, REAC stimulation provided a "physical milieu" optimizing stem cell expression of pluripotentiality and the attainment of three major target lineages for regenerative medicine, without using chemical agonists or vector-mediated gene delivery.
Collapse
Affiliation(s)
- Margherita Maioli
- Department of Biomedical Sciences, University of Sassari, Sassari, Italy
| | | | | | | | | | | | | | | |
Collapse
|
5
|
Ventura C. CAM and cell fate targeting: molecular and energetic insights into cell growth and differentiation. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE : ECAM 2005; 2:277-83. [PMID: 16136206 PMCID: PMC1193541 DOI: 10.1093/ecam/neh100] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2005] [Accepted: 06/22/2005] [Indexed: 12/29/2022]
Abstract
Evidence-based medicine is switching from the analysis of single diseases at a time toward an integrated assessment of a diseased person. Complementary and alternative medicine (CAM) offers multiple holistic approaches, including osteopathy, homeopathy, chiropractic, acupuncture, herbal and energy medicine and meditation, all potentially impacting on major human diseases. It is now becoming evident that acupuncture can modify the expression of different endorphin genes and the expression of genes encoding for crucial transcription factors in cellular homeostasis. Extremely low frequency magnetic fields have been found to prime the commitment to a myocardial lineage in mouse embryonic stem cells, suggesting that magnetic energy may direct stem cell differentiation into specific cellular phenotypes without the aid of gene transfer technologies. This finding may pave the way to novel approaches in tissue engineering and regeneration. Different ginseng extracts have been shown to modulate growth and differentiation in pluripotent cells and to exert wound-healing and antitumor effects through opposing activities on the vascular system, prompting the hypothesis that ancient compounds may be the target for new logics in cell therapy. These observations and the subtle entanglement among different CAM systems suggest that CAM modalities may deeply affect both the signaling and transcriptional level of cellular homeostasis. Such a perception holds promises for a new era in CAM, prompting reproducible documentation of biological responses to CAM-related strategies and compounds. To this end, functional genomics and proteomics and the comprehension of the cell signaling networks may substantially contribute to the development of a molecular evidence-based CAM.
Collapse
Affiliation(s)
- Carlo Ventura
- Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems and Institute of Cardiology, S. Orsola-Malpighi Hospital, University of Bologna 40138 Bologna, Italy.
| |
Collapse
|
6
|
Ventura C, Maioli M, Asara Y, Santoni D, Mesirca P, Remondini D, Bersani F. Turning on stem cell cardiogenesis with extremely low frequency magnetic fields. FASEB J 2004; 19:155-7. [PMID: 15507470 DOI: 10.1096/fj.04-2695fje] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Modulation of stem cell differentiation is an important assignment for cellular engineering. Embryonic stem (ES) cells can differentiate into cardiomyocytes, but the efficiency is typically low. Here, we show that exposure of mouse ES cells to extremely low frequency magnetic fields triggered the expression of GATA-4 and Nkx-2.5, acting as cardiac lineage-promoting genes in different animal species, including humans. Magnetic fields also enhanced prodynorphin gene expression, and the synthesis and secretion of dynorphin B, an endorphin playing a major role in cardiogenesis. These effects occurred at the transcriptional level and ultimately ensued into a remarkable increase in the yield of ES-derived cardiomyocytes. These results demonstrate the potential use of magnetic fields for modifying the gene program of cardiac differentiation in ES cells without the aid of gene transfer technologies and may pave the way for novel approaches in tissue engineering and cell therapy.
Collapse
Affiliation(s)
- Carlo Ventura
- Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems, University of Bologna, Bologna, Italy.
| | | | | | | | | | | | | |
Collapse
|
7
|
Ikeda M, Nelson CS, Shinagawa H, Shinoe T, Sugiyama T, Allen CN, Grandy DK, Yoshioka T. Cyclic AMP regulates the calcium transients released from IP(3)-sensitive stores by activation of rat kappa-opioid receptors expressed in CHO cells. Cell Calcium 2001; 29:39-48. [PMID: 11133354 DOI: 10.1054/ceca.2000.0161] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We analyzed intracellular Ca(2+)and cAMP levels in Chinese hamster ovary cells expressing a cloned rat kappa opioid receptor (CHO-kappa cells). Although expression of kappa(kappa)-opioid receptors was confirmed with a fluorescent dynorphin analog in almost all CHO-kappa cells, the kappa-specific agonists, U50488H or U69593, induced a Ca(2+) transient only in 35% of the cells. The Ca(2+) response occurred in all-or-none fashion and the half-maximal dosage of U50488H (812.1nM) was higher than that (3.2nM) to inhibit forskolin-stimulated cAMP. The kappa-receptors coupled to G(i/o)proteins since pertussis toxin significantly reduced the U50488H actions on intracellular Ca(2+) and cAMP. The Ca(2+) transient originates from IP(3)-sensitive internal stores since the Ca(2+) response was blocked by a PLC inhibitor (U73122) or by thapsigargin depletion of internal stores while removal of extracellular Ca(2+) had no effect. Interestingly, application of dibutyryl cAMP (+ 56.2%) or 8-bromo-cAMP (+ 174.7%) significantly increased the occurrence of U50488H-induced Ca(2+) mobilization while protein kinase A (PKA) inhibitors, Rp-cAMP (-32.3%) or myr-psi PKA (-73.9%) significantly reduced the response. Therefore, it was concluded that cAMP and PKA activity can regulate the Ca(2+) mobilization. These results suggest that the kappa receptor-linked cAMP cascade regulates the occurrence of kappa-opioid-mediated Ca(2+) mobilization.
Collapse
MESH Headings
- 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer/pharmacology
- 8-Bromo Cyclic Adenosine Monophosphate/pharmacology
- Analgesics/pharmacology
- Analgesics, Non-Narcotic/pharmacology
- Analgesics, Opioid/pharmacology
- Animals
- Benzeneacetamides
- Bucladesine/pharmacology
- CHO Cells
- Calcium/metabolism
- Calcium Signaling/drug effects
- Calcium Signaling/physiology
- Cloning, Molecular
- Colforsin/pharmacology
- Cricetinae
- Cyclic AMP/analogs & derivatives
- Cyclic AMP/metabolism
- Cyclic AMP/pharmacology
- Enkephalin, Ala(2)-MePhe(4)-Gly(5)-/pharmacology
- Enkephalin, D-Penicillamine (2,5)-/pharmacology
- Enzyme Inhibitors/pharmacology
- Gene Expression/physiology
- Inositol 1,4,5-Trisphosphate/metabolism
- Peptides
- Pyrrolidines/pharmacology
- Rats
- Receptors, Opioid, kappa/analysis
- Receptors, Opioid, kappa/genetics
- Receptors, Opioid, kappa/metabolism
- Thionucleotides/pharmacology
- Transfection
Collapse
Affiliation(s)
- M Ikeda
- Advanced Research Institute for Science and Engineering, Waseda University, Okubo, Shinjuku-ku, Tokyo, Japan.
| | | | | | | | | | | | | | | |
Collapse
|
8
|
Lester JW, Hofmann PA. Role for PKC in the adenosine-induced decrease in shortening velocity of rat ventricular myocytes. Am J Physiol Heart Circ Physiol 2000; 279:H2685-93. [PMID: 11087222 DOI: 10.1152/ajpheart.2000.279.6.h2685] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We previously demonstrated that both adenosine receptor activation and direct activation of protein kinase C (PKC) decrease unloaded shortening velocity (V(max)) of rat ventricular myocytes. The goal of this study was to further investigate a possible link among adenosine receptors, phosphoinositide-PKC signaling, and V(max) in rat ventricular myocytes. We determined that the adenosine receptor agonist R-phenylisopropyladenosine (R-PIA, 100 microM) and the alpha-adrenergic receptor agonist phenylephrine (Phe, 10 microM) increased turnover of inositol phosphates. PKC translocation from the cytosol to the sarcolemma was used as an indicator of PKC activation. Western blot analysis demonstrated an increased PKC-epsilon translocation after exposure to R-PIA, Phe, and the PKC activators dioctanoylglycerol (50 microM) and phorbol myristate acetate (1 microM). PKC-alpha, PKC-delta, and PKC-zeta did not translocate to the membrane after R-PIA exposure. Finally, PKC inhibitors blocked R-PIA-induced decreases in V(max) as well as Ca(2+)-dependent actomyosin ATPase in rat ventricular myocytes. These results support the conclusions that adenosine receptors activate phosphoinositide-PKC signaling and that adenosine receptor-induced PKC activation mediates a decrease in V(max) in ventricular myocytes.
Collapse
Affiliation(s)
- J W Lester
- Department of Physiology, University of Tennessee, Memphis, Tennessee 38163, USA
| | | |
Collapse
|
9
|
Abstract
Zinc finger-containing transcription factor GATA-4 and homeodomain Nkx-2.5 govern crucial developmental fates and have been found to promote cardiogenesis in embryonic cells exposed to the differentiating agent DMSO. Nevertheless, intracellular activators of these transcription factors are largely unknown. In this study, pluripotent P19 cells expressed the prodynorphin gene, an opioid gene encoding for the dynorphin family of opioid peptides. P19 cells were also able to synthesize and secrete dynorphin B, a biologically active end product of the prodynorphin gene. DMSO-primed GATA-4 and Nkx-2.5 gene expression was preceded by a marked increase in prodynorphin gene expression and dynorphin B synthesis and secretion. The DMSO effect occurred at the transcriptional level. In the absence of DMSO, dynorphin B triggered GATA-4 and Nkx-2.5 gene expression and led to the appearance of both alpha-myosin heavy chain and myosin light chain-2V transcripts, two markers of cardiac differentiation. Moreover, dynorphin B-exposed cells were positively stained in the presence of MF 20, a mouse monoclonal antibody raised against the alpha-myosin heavy chain. Opioid receptor antagonism and inhibition of opioid gene expression by a prodynorphin antisense phosphorothioate oligonucleotide blocked DMSO-induced cardiogenesis, suggesting an autocrine role of an opioid gene in developmental decisions.
Collapse
Affiliation(s)
- C Ventura
- Department of Biomedical Sciences, Division of Biochemistry, Laboratory of Cardiovascular Research, University of Sassari, Sassari, Italy.
| | | |
Collapse
|
10
|
Pignatti C, Stanic I, Stefanelli C, Tantini B, Rossoni C, Flamigni F. Modulation of the induction of ornithine decarboxylase by some opioid receptor agonists in immune cells and cardiomyocytes. Mol Cell Biochem 1998; 185:47-53. [PMID: 9746211 DOI: 10.1023/a:1006857027551] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The ability of natural and synthetic opioids to modulate the induction of ornithine decarboxylase (ODC) was investigated in immune cells and cardiomyocytes in culture. In particular, Leu-enkephalin, which shows preference for delta-receptors, enhanced ODC activity in both thymocytes and cardiomyocytes, whereas the effect of U-50488H, a synthetic kappa-selective agonist, was cell-specific. In thymocytes, U-50488H markedly inhibited the induction of the enzyme elicited by the mitogen concanavalin A (Con A) or by a combined treatment with PMA and A23187, and also reduced basal ODC activity. However the drug did not affect ODC induced by other stimuli. The inhibition of the induction of ODC activity was accompanied by a reduction of ODC mRNA level and an acceleration of ODC turnover. The action of U-50488H in thymocytes does not appear to be mediated by kappa or other classical opioid receptors lacking both stereospecificity and antagonist sensitivity, but may involve a pertussis toxin-sensitive G protein. Splenocytes also showed the ODC inhibiting effect of U-50488H, although they were less sensitive compared to thymocytes. In contrast, U-50488H enhanced ODC activity in cardiomyocytes and this effect was blocked by a specific kappa-antagonist. In conclusion, these results indicate that some opioid agonists can modulate ODC expression in non neural cells. In particular, kappa-opioid receptors may be involved in the U-50488H action in cardiomyocytes, and a distinct site, linked to inhibition of cell proliferation, may operate in immune cells.
Collapse
Affiliation(s)
- C Pignatti
- Dipartimento di Biochimica G. Moruzzi, Università di Bologna, Italy
| | | | | | | | | | | |
Collapse
|
11
|
Novakova M, Ela C, Bowen WD, Hasin Y, Eilam Y. Highly selective sigma receptor ligands elevate inositol 1,4,5-trisphosphate production in rat cardiac myocytes. Eur J Pharmacol 1998; 353:315-27. [PMID: 9726662 DOI: 10.1016/s0014-2999(98)00398-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Exposure of cardiac myocytes from adult rat ventricles to the highly selective, high affinity sigma receptor ligands 1S,2 R-cis-N-[2-(3,4-dichlorophenyl)ethyl]-N-methyl-2-(1-pyrrolidinyl)-cycloh exylamine (BD-737) (0.1-100 nM) and N-[2-(3,4-dichlorophenyl)ethyl]-N,N',N'-trimethylethylenediamine (BD-1047) (0.01-10 nM), caused potentiation of electrically-evoked amplitudes of contraction and Ca2+ transients, while exposure to 100 nM BD-1047 caused attenuation of these amplitudes. In addition, BD-737 (1-100 nM) and BD-1047 (10-100 nM) caused an increase in the incidence of spontaneous twitches. These effects were inhibited when the incubation with BD-737 was done in the presence of the phospholipase C inhibitor, neomycin, or after pre-incubation with thapsigargin or caffeine which deplete the sarcoplasmic reticulum Ca2+ stores. Inositol 1,4,5-trisphosphate (IP3) production in cardiac myocytes was determined by the IP3 binding protein assay. Both substances caused an increase in the intracellular concentration of IP3. BD-737 caused a rapid transient increase to 3.2-fold in 1 min and stabilization at 2.1-fold of control thereafter. BD-1047 caused a gradual increase reaching 4.4-fold after 5 min. The results suggest that the effects of these sigma receptor ligands on contractility and spontaneous contractions are mediated by activation of phospholipase C and elevation of intracellular IP3 level.
Collapse
Affiliation(s)
- M Novakova
- Department of Bacteriology, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | | | | | | | | |
Collapse
|
12
|
Viko H, Sandnes D, Skomedal T, Osnes JB. Effect of concomitant beta-adrenoceptor stimulation on alpha 1-adrenoceptor-mediated increase of inositol-1,4,5-trisphosphate mass in adult rat cardiomyocytes. PHARMACOLOGY & TOXICOLOGY 1998; 83:23-8. [PMID: 9764422 DOI: 10.1111/j.1600-0773.1998.tb01437.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The aim of the present study was to investigate the accumulation of inositol-1,4,5-trisphosphate (IP3) in isolated adult rat ventricular cardiomyocytes after alpha 1- and beta-adrenoceptor stimulation, separate and in combination, in order to elucidate a possible influence of concomitant beta-adrenoceptor stimulation on the alpha 1-adrenoceptor stimulated response. IP3 was measured by a radioligand binding assay based on an (1,4,5)IP3-specific binding protein from bovine adrenal cortex. The basal IP3 content was 4.06 +/- 0.31 pmol/mg protein (N = 56). alpha 1-Adrenoceptor stimulation resulted in a rapid increase in the IP3 level, which reached a plateau, 50-80% above basal level, at 10-30 sec. The plateau lasted at least up to 120 sec., while at 300 sec. there was no significant difference between control values and values after alpha 1-adrenoceptor stimulation. Li+ did not affect either the basal IP3 level, or the magnitude or time course of alpha 1-adrenoceptor-stimulated IP3 accumulation. Combined adrenoceptor stimulation gave a similar response as separate alpha 1-adrenoceptor stimulation, whereas there was no significant change in the IP3 level after beta-adrenoceptor stimulation. No inhibitory influence of simultaneous beta-adrenoceptor stimulation on the alpha 1-adrenoceptor-stimulated increase of IP3 mass was revealed.
Collapse
Affiliation(s)
- H Viko
- Department of Pharmacology, University of Oslo, Norway
| | | | | | | |
Collapse
|
13
|
Ventura C, Pintus G, Fiori MG, Bennardini F, Pinna G, Gaspa L. Opioid peptide gene expression in the primary hereditary cardiomyopathy of the Syrian hamster. I. Regulation of prodynorphin gene expression by nuclear protein kinase C. J Biol Chem 1997; 272:6685-92. [PMID: 9045700 DOI: 10.1074/jbc.272.10.6685] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Prodynorphin gene expression was investigated in adult ventricular myocytes isolated from normal (F1B) or cardiomyopathic (BIO 14.6) hamsters. Prodynorphin mRNA levels were higher in cardiomyopathic than in control myocytes and were stimulated by treatment of control cells with the protein kinase C (PKC) activator 1, 2-dioctanoyl-sn-glycerol. Both chelerythrine and calphostin C, two PKC inhibitors, abolished the stimulatory effect of the diglyceride and significantly reduced prodynorphin gene expression in cardiomyopathic myocytes. Nuclear run-off experiments indicated that the prodynorphin gene was regulated at the transcriptional level and that treatment of nuclei isolated from control cells with 1, 2-dioctanoyl-sn-glycerol increased prodynorphin gene transcription, whereas chelerythrine or calphostin C abolished this transcriptional effect. Direct exposure of nuclei isolated from cardiomyopathic myocytes to these inhibitors markedly down-regulated the rate of gene transcription. The expression of PKC-alpha, -delta, and -epsilon, as well as PKC activity, were increased in nuclei of cardiomyopathic myocytes compared with nuclei from control cells. The levels of both intracellular and secreted dynorphin B, a biologically active product of the gene, were higher in cardiomyopathic than in control cells and were stimulated or inhibited by cell treatment with 1,2-dioctanoyl-sn-glycerol or PKC inhibitors, respectively.
Collapse
Affiliation(s)
- C Ventura
- Institute of Biological Chemistry "A. Bonsignore," School of Medicine, University of Sassari, Viale San Pietro 43/B, 07100 Sassari, Italy
| | | | | | | | | | | |
Collapse
|
14
|
Ventura C, Pintus G. Opioid peptide gene expression in the primary hereditary cardiomyopathy of the Syrian hamster. III. Autocrine stimulation of prodynorphin gene expression by dynorphin B. J Biol Chem 1997; 272:6699-705. [PMID: 9045702 DOI: 10.1074/jbc.272.10.6699] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Prodynorphin mRNA and dynorphin B expression have been previously shown to be greatly increased in cardiac myocytes of BIO 14.6 cardiomyopathic hamsters. Here we report that exogenous dynorphin B induced a dose-dependent increase in prodynorphin mRNA levels and stimulated prodynorphin gene transcription in normal hamster myocytes. Similar responses were elicited by the synthetic selective kappa opioid receptor agonist U-50,488H. These effects were counteracted by the kappa opioid receptor antagonist Mr-1452 and were not observed in the presence of chelerythrine or calphostin C, two specific protein kinase C (PKC) inhibitors. Treatment of cardiomyopathic cells with Mr-1452 significantly decreased both prodynorphin mRNA levels and prodynorphin gene transcription. In control myocytes, dynorphin B induced the translocation of PKC-alpha to the nucleus and increased nuclear PKC activity without affecting the expression of PKC-delta, -epsilon, or -zeta. Acute release of either U-50,488H or dyn B over single normal or cardiomyopathic cells transiently increased the cytosolic Ca2+ concentration. A sustained treatment with each opioid agonist increased the cytosolic Ca2+ level for a more prolonged period in cardiomyopathic than in control myocytes and led to a depletion of Ca2+ from the sarcoplasmic reticulum in both groups of cells. The possibility that prodynorphin gene expression may affect the function of the cardiomyopathic cell through an autocrine mechanism is discussed.
Collapse
Affiliation(s)
- C Ventura
- Institute of Biological Chemistry "A. Bonsignore," School of Medicine, University of Sassari, Viale San Pietro 43/B, 07100 Sassari, Italy
| | | |
Collapse
|
15
|
Sheng JZ, Wong NS, Tai KK, Wong TM. Lithium attenuates the effects of dynorphin A(1-13) on inositol 1,4,5-trisphosphate and intracellular Ca2+ in rat ventricular myocytes. Life Sci 1996; 59:2181-6. [PMID: 8950322 DOI: 10.1016/s0024-3205(96)00575-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
When rat ventricular myocytes were stimulated with dynorphin A(1-13), a transient and rapid increase followed by a sustained and prolonged elevation in the intracellular levels of inositol 1,4,5-trisphosphate ¿Ins(1,4,5)P3¿ was observed. The responses were dose-related and abolished by nor-binaltorphimine. In the presence of lithium and absence of extracellular free inositol, the initial rapid elevation in Ins(1,4,5)P3 remained the same, but the second phase of sustained and prolonged elevation was abolished. Under this condition, the elevation in cytosolic free Ca2+ ([Ca2+]i) was reduced significantly although there was still a detectable elevation over a time period when the Ins(1,4,5)P3 was at the basal level. The responses in Ins(1,4,5)P3 and [Ca2+]i were not affected by lithium when stimulation of ventricular myocytes with dynorphin A(1-13) was performed in the presence of extracellular inositol. The data suggest that in rat ventricular myocytes, the kappa-opioid receptor agonist stimulated mobilization of [Ca2+]i was mediated mainly by Ins(1,4,5)P3.
Collapse
Affiliation(s)
- J Z Sheng
- Department of Physiology, Faculty of Medicine, University of Hong Kong, Hong Kong
| | | | | | | |
Collapse
|
16
|
Hanem S, Enger M, Skomedal T, Osnes JB. Inositol-1,4,5-trisphosphate mass content in isolated perfused rat heart during alpha-1-adrenoceptor stimulation. Mol Cell Biochem 1996; 163-164:167-72. [PMID: 8974053 DOI: 10.1007/bf00408654] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Inositol-1,4,5-trisphosphate (IP3) has been proposed to be a second messenger in response to alpha-1-adrenoceptor stimulation also in myocardial cells. We studied the effect of alpha-1-adrenoceptor stimulation (5 x 10(-5) mol/l phenylephrine or 5 x 10(-5) mol/l noradrenaline both in the presence of 10(-6) mol/l timolol) on IP3 mass content in isolated perfused rat hearts. IP3 content was determined by a specific receptor-binding assay-kit (TRK 1000, Amersham) after validating the method. For comparison also the effect of muscarinic stimulation (10(-4) mol/l carbachol in the presence of 10(-6) mol/l timolol) on IP3 content was measured in corresponding preparations. A basal IP3 level of about 75 pmol/mg protein was found. There were no prominent effects of alpha-1-adrenoceptor stimulation on total IP3 content in isolated perfused rat hearts. Phenylephrine gave a statistically significant increase of about 40% at 1/4 min and a statistically significant decrease of about 25% at 4 min after start of exposure. Noradrenaline, however, gave no statistically significant change of IP3 at the time-points studied. Muscarinic stimulation caused a slight, statistically insignificant, increase of IP3 at 1/4 min. The results are compatible with an assumption that agonist stimulation evokes a localized increase of IP3 which may be masked by a relatively high total IP3 mass content. The IP3 peak after phenylephrine coincided with the early positive inotropic phase of the response reported earlier in perfused rat hearts for alpha-1-adrenoceptor stimulation by phenylephrine. Although this might be compatible with a role for IP3 in this early and transient phase, a mediator function of IP3 in the inotropic response is not established.
Collapse
Affiliation(s)
- S Hanem
- Department of Pharmacology, University of Oslo, Norway
| | | | | | | |
Collapse
|
17
|
Flamigni F, Stefanelli C, Stanic I, Muscari C, Giaccari A, Rossoni C. Inhibition of the expression of ornithine decarboxylase by some kappa-opioidergic receptor ligands in difluoromethylornithine-resistant L1210 cells. BIOCHIMICA ET BIOPHYSICA ACTA 1996; 1311:204-10. [PMID: 8664348 DOI: 10.1016/0167-4889(96)00009-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
In difluoromethylornithine resistant L1210 cells stimulated to growth from quiescence, the selective kappa-opioidergic agonist trans-(+/-)-3,4-dichloro-N-[2-(1-pyrrolidinyl)cyclohexyl]benzeneaceta mid e (U-50488H) caused a dose dependent inhibition of the induction of ODC activity, with a half-maximal effect at about 1 microM. U-50488H also provoked reduction of ODC mRNA level and increase of ODC turnover, as well as inhibition of cell growth. U-69593, another kappa-selective agonist, was only slightly effective. The action of U-50488H on ODC induction was not blocked by naloxone, beta-chlornaltrexamine or by the kappa-selective opioid antagonists Mr1452 and nor-binaltorphimine (nBNI). Actually Mr1452 and nBNI exerted some inhibitory effect. Furthermore, the separated enantiomers (+) and (-) of U-50488H were similarly effective. The (-)cis-(1S,2R)-U50488 stereoisomer, exhibiting low affinity for kappa and high affinity for sigma receptors and carbetapentane, another sigma ligand, also inhibited ODC induction, although less effectively than U-50488H. None of several other opioid ligands tested had significant effects on ODC induction. In conclusion, the inhibition of ODC expression by U-50488H does not involve classical, enantiospecific opioid receptors; rather, these results suggest the involvement of a distinct site of action linked to inhibition of lymphoid cell proliferation.
Collapse
Affiliation(s)
- F Flamigni
- Dipartimento di Biochimica G. Moruzzi, Università di Bologna, Italy
| | | | | | | | | | | |
Collapse
|
18
|
Zimlichman R, Gefel D, Eliahou H, Matas Z, Rosen B, Gass S, Ela C, Eilam Y, Vogel Z, Barg J. Expression of opioid receptors during heart ontogeny in normotensive and hypertensive rats. Circulation 1996; 93:1020-5. [PMID: 8598065 DOI: 10.1161/01.cir.93.5.1020] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND The opioidergic systems are involved in modulating nociceptive stimuli. In addition, the recent results suggest that endogenous and exogenous opioids could play a role in the modulation of blood pressure and cardiac functions. However, little is known regarding the expression and role of opioid-binding sites in the heart. The decreased sensitivity to noxious stimuli in hypertensive rats raises the possibility of different developmental pattern expression of opioid-binding sites in normotensive versus hypertensive rats. METHODS AND RESULTS Opioid receptor expression in hearts from hypertensive and normotensive rats was studied during heart development by binding assays. From P1 until P90, the development of the heart in the two rat strains was accompanied by a gradual increase in the density of kappa-opioid receptors. Hearts from hypertensive rats expressed significantly higher levels of kappa receptors compared with those of normotensive rats. At ages older than P7, mu-opioid receptors could not be detected in hearts of both strains, whereas delta-opioid-binding sites gradually increased until reaching adult levels. Seven-day-old cardiomyocyte cultures of both rat strains expressed similar densities of delta or kappa receptors to those observed in hearts from 7-day-old neonates. The mu-binding sites were not detected in cardiomyocytes cultures. Similar to the in vivo state, cultured myocytes from hypertensive rats had significantly higher levels of kappa-binding sites (1.5 fold) compared with those of normotensive rats. The kappa sites are pertussis toxin sensitive, and the state of coupling of the receptor to G protein is similar for the two rat strains. CONCLUSION The role of opioid-binding sites in the heart is not completely clear. Hypertensive rats are known to be less sensitive to noxious stimuli compared with normotensive rats. It is controversial whether the site if application of noxious stimuli plays an important role in the sensitivity to pain in hypertensive rats. We suggest that the opioidergic system could play a role in the modulation of blood pressure in addition to its known effect on nociception.
Collapse
Affiliation(s)
- R Zimlichman
- Department of Internal Medicine, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Dumont M, Lemaire S. Opioid and nonopioid cardiovascular effects of dynorphins. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 1996; 37:1-33. [PMID: 8891098 DOI: 10.1016/s1054-3589(08)60946-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- M Dumont
- Department of Pharmacology, University of Ottawa, Ontario, Canada
| | | |
Collapse
|
20
|
Ventura C, Pintus G, Vaona I, Bennardini F, Pinna G, Tadolini B. Phorbol ester regulation of opioid peptide gene expression in myocardial cells. Role of nuclear protein kinase. J Biol Chem 1995; 270:30115-20. [PMID: 8530417 DOI: 10.1074/jbc.270.50.30115] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Opioid peptide gene expression was characterized in adult rat ventricular cardiac myocytes that had been cultured in the absence or the presence of phorbol 12-myristate 13-acetate. The phorbol ester induced a concentration- and time-dependent increase of prodynorphin mRNA, the maximal effect being reached after 4 h of treatment. The increase in mRNA expression was suppressed by incubation of cardiomyocytes with staurosporine, a putative protein kinase C inhibitor, and was not observed when the cells were cultured in the presence of the inactive phorbol ester 4 alpha-phorbol 12,13-didecanoate. Incubation of cardiac myocytes with phorbol 12-myristate 13-acetate also elicited a specific and staurosporine-sensitive increase in immunoreactive dynorphin B, a biologically active end product of the precursor, both in the myocardial cells and in the culture medium. In vitro run-off transcription assays indicated that transcription of the prodynorphin gene was increased both in nuclei isolated from phorbol ester-treated myocytes and in nuclei isolated from control cells and then exposed to phorbol 12-myristate 13-acetate. No transcriptional effect was observed when cardiac myocytes or isolated nuclei where exposed to 4 alpha-phorbol 12,13-didecanoate. The phorbol ester-induced increase in prodynorphin gene transcription was prevented by pretreatment of myocytes or isolated nuclei with staurosporine, suggesting that myocardial opioid gene expression may be regulated by nuclear protein kinase C. In this regard, cardiac myocytes expressed protein kinase C-alpha, -delta, -epsilon, and -zeta, as shown by immunoblotting. Only protein kinase C-delta and protein kinase C-epsilon were expressed in nuclei that have been isolated from control myocytes, suggesting that these two isotypes of the enzyme may be part of the signal transduction pathway involved in the effect elicited by the phorbol ester on opioid gene transcription in isolated nuclei. The incubation of myocardial nuclei isolated from control cells in the presence of a protein kinase C activator induced the phosphorylation of the myristoylated alanine-rich protein kinase C substrate peptide, a specific fluorescent substrate of the enzyme. The possibility that prodynorphin gene expression may control the heart function through autocrine or paracrine mechanisms is discussed.
Collapse
Affiliation(s)
- C Ventura
- Institute of Biological Chemistry A. Bonsignore, School of Medicine, University of Sassari, Italy
| | | | | | | | | | | |
Collapse
|
21
|
Hansen CA, Joseph SK, Robishaw JD. Ins 1,4,5-P3 and Ca2+ signaling in quiescent neonatal cardiac myocytes. BIOCHIMICA ET BIOPHYSICA ACTA 1994; 1224:517-26. [PMID: 7803511 DOI: 10.1016/0167-4889(94)90289-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Activation of alpha 1-adrenergic receptors in neonatal cardiac myocytes results in changes in contractile activity and the induction of hypertrophic growth. The biochemical mechanisms responsible for these diverse effects are not yet established, but presumably involve the associated alpha 1-adrenergic stimulation of phosphatidylinositol (PI) hydrolysis, with concomitant generation of Ins 1,4,5-P3 and diacylglycerol. This study examined whether alpha 1-adrenergic generation of Ins 1,4,5-P3 in intact, quiescent, neonatal cardiac myocytes resulted in a Ca2+ signal. Stimulation of myocytes with norepinephrine in the presence of propranolol caused accumulation of inositol mono-, bis and trisphosphates. However, alpha 1-adrenergic stimulation did not alter cytosolic free Ca2+ levels in 85% of the myocytes examined. Direct generation of Ins 1,4,5-P3, by photolysis of microinjected caged Ins 1,4,5-P3, was also unable to alter cytosolic free Ca2+ levels, despite the presence of Ins 1,4,5-P3 receptors. Taken together, these data indicated that alpha 1-adrenergic stimulation did not initiate Ca2+ signaling because Ins 1,4,5-P3-induced Ca2+ mobilization was not operative in quiescent neonatal cardiac myocytes. Normal excitation-contraction Ca2+ handling mechanisms were present in these cells, as illustrated by depolarization- and caffeine-induced Ca2+ transients. Analysis of these same myocytes following 48 h in the presence of norepinephrine and propranolol showed a 40% increase in the ratio of protein to DNA and a 350% increase in release of atrial naturietic factor, compared to control cells, indicating the normal operation of alpha 1-adrenergic-induced hypertrophic growth. Therefore, the assumption that Ca(2+)-dependent processes will be activated by receptor signaling pathways coupled to enhanced phosphatidylinositol turnover in cardiac cells must be avoided. In addition, the data presented in this study clearly indicated that an increase in cytosolic free Ca2+ was not necessary for the induction of alpha 1-adrenergic-mediated cardiac hypertrophy.
Collapse
Affiliation(s)
- C A Hansen
- Geisinger Clinic, Weis Center For Research, Danville, PA 17822-2619
| | | | | |
Collapse
|
22
|
Gq- and ras-dependent pathways mediate hypertrophy of neonatal rat ventricular myocytes following alpha 1-adrenergic stimulation. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)36858-8] [Citation(s) in RCA: 127] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
|
23
|
|
24
|
|
25
|
Canossa M, Ventura C, Vaona I, Carboni L, Guarnieri C, Spampinato S. Prodynorphin mRNA expression in adult cultured rat ventricular cardiac myocytes. BIOCHIMICA ET BIOPHYSICA ACTA 1993; 1172:247-50. [PMID: 8448203 DOI: 10.1016/0167-4781(93)90210-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Prodynorphin mRNA was synthesized both in rat atrial and ventricular tissue, as well as in adult cultured rat ventricular cardiac myocytes. In the cultured cells, the content of prodynorphin mRNA did not differ from that detected in the original ventricle, indicating that the myocardial cell is an important source for prodynorphin mRNA in the rat ventricular tissue. This study demonstrated the presence of immunoreactive dynorphin B-like material in the cultured cardiomyocytes. Gel permeation chromatography analysis of this material revealed the presence of forms with an apparently higher molecular weight than authentic dynorphin B.
Collapse
Affiliation(s)
- M Canossa
- Department of Pharmacology, University of Bologna, Italy
| | | | | | | | | | | |
Collapse
|
26
|
|
27
|
Gambassi G, Spurgeon HA, Lakatta EG, Blank PS, Capogrossi MC. Different effects of alpha- and beta-adrenergic stimulation on cytosolic pH and myofilament responsiveness to Ca2+ in cardiac myocytes. Circ Res 1992; 71:870-82. [PMID: 1516160 DOI: 10.1161/01.res.71.4.870] [Citation(s) in RCA: 62] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
alpha-Adrenergic stimulation (alpha-AS) and beta-adrenergic stimulation (beta-AS) of the myocardium are associated respectively with an increase and a decrease in myofilament responsiveness to Ca2+. We hypothesized that changes in cytosolic pH (pH(i)) may modulate these opposite actions of alpha-AS and beta-AS. The effects of alpha-AS (50 microM phenylephrine and 1 microM nadolol) and beta-AS (0.05 microM isoproterenol) on contraction and either cytosolic Ca2+ (Cai) or pH(i) were assessed in adult rat ventricular myocytes bathed in bicarbonate buffer (pH 7.36 +/- 0.05). In cells loaded with the ester derivative (AM form) of indo-1, the 410/490-nm ratio of emitted fluorescence indexed Cai. Myofilament responsiveness to Ca2+ was assessed by the relaxation phase of the length-indo-1 fluorescence relation during a twitch. alpha-AS and beta-AS shifted this relation in opposite directions, indicating that alpha-AS increased and beta-AS decreased myofilament responsiveness to Ca2+. In addition, the positive inotropic action of alpha-AS was associated with an increased Cai transient amplitude in 50% of the myocytes (n = 12), whereas beta-AS always increased Cai (n = 5). In cells loaded with the fluorescent pH(i) probe SNARF-1 AM, the emitted 590/640-nm fluorescence is a measure of pH(i). The effect of alpha-AS on the extent of cell shortening during the twitch (ES) was expressed as the percentage of resting cell length. Both ES and pH(i) were assessed in myocytes bathed in 1.5 mM [Ca2+] and stimulated at 0.5 Hz (control ES, 7.4 +/- 1.5%; control pH(i), 7.11 +/- 0.05; n = 10). alpha-AS enhanced both ES (delta ES, 1.8 +/- 0.6%; p less than 0.05) and pH(i) (delta pH(i), 0.06 +/- 0.01; p less than 0.005), and there was a significant correlation between delta ES and delta pH(i) (r = 0.76, p less than 0.05). A similar effect of alpha-AS on pH(i) was observed in the absence of electrical stimulation (n = 8). The alpha-AS-induced enhancement of ES and pH(i) was abolished by 10 microM ethylisopropylamiloride, a Na(+)-H+ exchange inhibitor (n = 7). In additional experiments, myocytes were preincubated either with 0.2 microM 4 beta-phorbol 12-myristate 13-acetate (n = 8) or with 5 nM staurosporine (n = 8), which have been shown to downregulate and inhibit Ca(2+)-activated phospholipid-dependent protein kinase C, respectively. In either group, alpha-AS had no effect on pH(i) and decreased ES to approximately 60% of control.(ABSTRACT TRUNCATED AT 400 WORDS)
Collapse
Affiliation(s)
- G Gambassi
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224
| | | | | | | | | |
Collapse
|
28
|
Hrelia S, Biagi PL, Turchetto E, Rossi CA, Bordoni A. Protein kinase C activity in neonatal cultured rat cardiomyocytes supplemented with docosahexaenoic acid. Biochem Biophys Res Commun 1992; 183:893-8. [PMID: 1312843 DOI: 10.1016/0006-291x(92)90567-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In vitro studies have indicated that the 1-stearoyl, 2-arachidonyl diacylglycerol (DAG) is the most effective one for the activation of protein kinase C, although many other DAGs having a different fatty acid composition are active, but to a different extent. Using cultures of neonatal rat ventricular cells, grown in a medium enriched in docosahexaenoic acid (DHA), we previously obtained a cell population that, after alpha 1-adrenoceptor stimulation, produced a DHA enriched DAG. In this study, we have tested the "in vivo" ability of this modified DAG as protein kinase C activator, demonstrating a lower but more persistent translocation of the enzyme from cytosol to particulate fraction in the DHA treated cells. The differences in the PKC activation pattern could be explained by a different metabolism of the DHA enriched DAG by DAG kinase.
Collapse
Affiliation(s)
- S Hrelia
- Dipartimento di Biochimica G. Moruzzi, University of Bologna, Italy
| | | | | | | | | |
Collapse
|
29
|
Kasper E, Ventura C, Ziman BD, Lakatta EG, Weisman H, Capogrossi MC. Effect of U-50,488H on the contractile response of cardiomyopathic hamster ventricular myocytes. Life Sci 1992; 50:2029-35. [PMID: 1608286 DOI: 10.1016/0024-3205(92)90568-a] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We examined the effects of a selective kappa opioid receptor agonist (U-50,488H) on the contractile properties of single ventricular myocytes from 127 day old control (F1B) and cardiomyopathic (BIO 14.6) hamsters. Myocytes in bicarbonate buffered solution with 1.5 mM [Ca2+] were electrically stimulated with field electrodes in the bath. Length changes were monitored via myocyte edge tracking. Twitch amplitude and the velocity of cell shortening were less in the cardiomyopathic hamster myocytes than in age-matched hamsters (P less than or equal to 0.05). There was a concentration-dependent effect of U-50,488H (0.1-20 microM) to decrease twitch amplitude and shortening velocity in both control and cardiomyopathic myocytes (P less than or equal to 0.001). In cells loaded with the Ca2+ indicator indo-1 the negative inotropic action of U-50,488H was associated with a decreased indo-1 fluorescence transient amplitude. There was no difference in the negative inotropic effect of U-50,488H on control and cardiomyopathic cells. Thus, the CM hamster does not demonstrate a different contractile response to U-50,488H.
Collapse
Affiliation(s)
- E Kasper
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224
| | | | | | | | | | | |
Collapse
|