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Obara K, Takahashi S, Otake M, Fujiwara M, Yamashita M, Murata A, Yoshioka K, Tanaka Y. Platelet-Activating Factor (PAF) Induces Strong Mechanical Activities Accompanied by Basal Tension Increases in Esophageal and Gastric Fundus Smooth Muscles from Rat. Biol Pharm Bull 2025; 48:563-570. [PMID: 40350298 DOI: 10.1248/bpb.b25-00125] [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] [Indexed: 05/14/2025]
Abstract
In rats, platelet-activating factor (PAF) has been reported to increase mechanical activity in various gastrointestinal smooth muscles (SMs) except for esophagus SM. The aim of this study was to examine whether PAF increases mechanical activity in rat esophagus longitudinal SM (LSM) and to compare PAF actions in esophagus LSM with those in other gastrointestinal LSMs. PAF (10-9-10-6 M) increased esophagus LSM mechanical activities in a concentration-dependent manner; PAF mainly elicited basal tension increases that were almost eliminated by a PAF receptor antagonist CV-6209 (10-5 M; against 10-6 M PAF). In the LSM of the gastric fundus, which is similar to esophagus LSM in that it is derived from the foregut during development, PAF (10-6 M) increased basal tension to a comparable, albeit significantly different, magnitude as in esophagus LSM. In contrast, in LSMs of the duodenum-jejunum, ileum, and ascending colon, which are derived from the midgut, and the descending colon, which is derived from the hindgut, the ability of PAF (10-6 M) to increase basal tension was less than that in esophagus and gastric fundus LSMs. Interestingly, in ascending colon LSMs, PAF (10-6 M) induced oscillatory contractions with a small increase in basal tension. PAF-induced contractions were positively correlated with the mRNA expression levels of the PAF-degrading enzymes Pafah2 (R = 0.82) and Pafah1b3 (R = 0.51). These results suggest that PAF strongly stimulates mechanical activities that are mainly accompanied by basal tension increases in rat LSMs of the gastrointestinal tracts that are derived from the foregut during embryogenesis.
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Affiliation(s)
- Keisuke Obara
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510, Japan
| | - Sana Takahashi
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510, Japan
| | - Miho Otake
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510, Japan
| | - Mako Fujiwara
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510, Japan
| | - Mio Yamashita
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510, Japan
| | - Azusa Murata
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510, Japan
| | - Kento Yoshioka
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510, Japan
| | - Yoshio Tanaka
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510, Japan
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Allam S, Krüger D, Michel K, Schnabl K, Klingenspor M, Schemann M, Annaházi A. Mechanisms involved in the muscle relaxing effects of STW 5 in guinea pig stomach. Neurogastroenterol Motil 2024; 36:e14761. [PMID: 38342975 DOI: 10.1111/nmo.14761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 01/17/2024] [Accepted: 01/30/2024] [Indexed: 02/13/2024]
Abstract
INTRODUCTION The herbal preparation STW 5 ameliorates functional dyspepsia partly by relaxing smooth muscle of the proximal stomach, thus improving gastric accommodation. We explored the unknown pathways responsible for this effect by testing targets known to modulate gastric smooth muscle relaxation. METHODS STW 5-induced relaxation of smooth muscle strips from guinea pig gastric corpus before and after pharmacological interventions were recorded with force transducers in an organ bath. ORAI1 mRNA expression was tested in the proximal stomach. KEY RESULTS Blockade of Ca2+-activated K+ and Cl- channels, voltage-gated L- or T-type Ca2+ channels, TRPA1-, TRPV1-, adenosine or 5-HT4 receptors, antagonizing ryanodine receptors, inhibiting cyclooxygenase or sarcoplasmic reticulum calcium ATPase did not affect STW 5-evoked relaxation. Likewise, protein-kinase A or G were not involved. However, the relaxation evoked by STW 5 was significantly reduced by phorbol-12-myristat-13-acetat, an activator of protein-kinase C, by 2- aminoethyldiphenylborinate, an inhibitor of the IP3 receptor-mediated Ca2+ release from the sarcoplasmic reticulum or by SKF-96365, a nonselective store-operated calcium entry (SOCE) blocker. Furthermore, the mixed TRPC3/SOCE inhibitor Pyr3, but not the selective TRPC3 blocker Pyr10, reduced the effect of STW 5. Finally, BTP2, a potent blocker of ORAI-coupled SOCE, almost abolished STW 5-evoked relaxation. Expression of ORAI1 could be demonstrated in the corpus/fundus. CONCLUSIONS & INFERENCES STW 5 inhibited SOCE, most likely ORAI channels, which are modulated by IP3- and PKC-dependent mechanisms. Our findings impact on the design of drugs to induce muscle relaxation and help identify phytochemicals with similar modes of actions to treat gastrointestinal disturbances.
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Affiliation(s)
- Shady Allam
- Chair of Human Biology, Technical University of Munich, Freising, Germany
- Pharmacology and Toxicology Department, Faculty of Pharmacy, Menoufia University, Shebeen El-Kom, Egypt
| | - Dagmar Krüger
- Chair of Human Biology, Technical University of Munich, Freising, Germany
| | - Klaus Michel
- Chair of Human Biology, Technical University of Munich, Freising, Germany
| | - Katharina Schnabl
- Chair for Molecular Nutritional Medicine, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Martin Klingenspor
- Chair for Molecular Nutritional Medicine, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Michael Schemann
- Chair of Human Biology, Technical University of Munich, Freising, Germany
| | - Anita Annaházi
- Chair of Human Biology, Technical University of Munich, Freising, Germany
- Chair of Zoology, Technical University of Munich, Freising, Germany
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Acid-gastric antisecretory effect of the ethanolic extract from Arctium lappa L. root: role of H +, K +-ATPase, Ca 2+ influx and the cholinergic pathway. Inflammopharmacology 2017; 26:521-530. [PMID: 28755129 DOI: 10.1007/s10787-017-0378-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2017] [Accepted: 07/12/2017] [Indexed: 01/06/2023]
Abstract
BACKGROUND Arctium lappa L., popularly known as burdock, is a medicinal plant used worldwide. The antiulcer and gastric-acid antisecretory effects of ethanolic extract from roots of Arctium lappa (EET) were already demonstrated. However, the mechanism by which the extract reduces the gastric acid secretion remains unclear. Therefore, this study was designed to evaluate the antisecretory mode of action of EET. MATERIALS AND METHODS The effects of EET on H+, K+-ATPase activity were verified in vitro, whereas the effects of the extract on cholinergic-, histaminergic- or gastrinergic-acid gastric stimulation were assessed in vivo on stimulated pylorus ligated rats. Moreover, ex vivo contractility studies on gastric muscle strips from rats were also employed. RESULTS The incubation with EET (1000 µg/ml) partially inhibited H+, K+-ATPase activity, and the intraduodenal administration of EET (10 mg/kg) decreased the volume and acidity of gastric secretion stimulated by bethanechol, histamine, and pentagastrin. EET (100-1000 µg/ml) did not alter the gastric relaxation induced by histamine but decreased acetylcholine-induced contraction in gastric fundus strips. Interestingly, EET also reduced the increase in the gastric muscle tone induced by 40 mM KCl depolarizing solution, as well as the maximum contractile responses evoked by CaCl2 in Ca2+-free depolarizing solution, without impairing the effect of acetylcholine on fundus strips maintained in Ca2+ -free nutritive solution. CONCLUSION Our results reinforce the gastric antisecretory properties of preparations obtained from Arctium lappa, and indicate that the mechanisms involved in EET antisecretory effects include a moderate reduction of the H+, K+-ATPase activity associated with inhibitory effects on calcium influx and of cholinergic pathways in the stomach muscle.
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Singh J, Rattan S. Bioengineered human IAS reconstructs with functional and molecular properties similar to intact IAS. Am J Physiol Gastrointest Liver Physiol 2012; 303:G713-22. [PMID: 22790596 PMCID: PMC3468534 DOI: 10.1152/ajpgi.00112.2012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Because of its critical importance in rectoanal incontinence, we determined the feasibility to reconstruct internal anal sphincter (IAS) from human IAS smooth muscle cells (SMCs) with functional and molecular attributes similar to the intact sphincter. The reconstructs were developed using SMCs from the circular smooth muscle layer of the human IAS, grown in smooth muscle differentiation media under sterile conditions in Sylgard-coated tissue culture plates with central Sylgard posts. The basal tone in the reconstructs and its changes were recorded following 0 Ca(2+), KCl, bethanechol, isoproterenol, protein kinase C (PKC) activator phorbol 12,13-dibutyrate, and Rho kinase (ROCK) and PKC inhibitors Y-27632 and Gö-6850, respectively. Western blot (WB), immunofluorescence (IF), and immunocytochemical (IC) analyses were also performed. The reconstructs developed spontaneous tone (0.68 ± 0.26 mN). Bethanechol (a muscarinic agonist) and K(+) depolarization produced contraction, whereas isoproterenol (β-adrenoceptor agonist) and Y-27632 produced a concentration-dependent decrease in the tone. Maximal decrease in basal tone with Y-27632 and Gö-6850 (each 10(-5) M) was 80.45 ± 3.29 and 17.76 ± 3.50%, respectively. WB data with the IAS constructs' SMCs revealed higher levels of RhoA/ROCK, protein kinase C-potentiated inhibitor or inhibitory phosphoprotein for myosin phosphatase (CPI-17), phospho-CPI-17, MYPT1, and 20-kDa myosin light chain vs. rectal smooth muscle. WB, IF, and IC studies of original SMCs and redispersed from the reconstructs for the relative distribution of different signal transduction proteins confirmed the feasibility of reconstruction of IAS with functional properties similar to intact IAS and demonstrated the development of myogenic tone with critical dependence on RhoA/ROCK. We conclude that it is feasible to bioengineer IAS constructs using human IAS SMCs that behave like intact IAS.
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Affiliation(s)
- Jagmohan Singh
- Division of Gastroenterology and Hepatology, Department of Medicine, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Satish Rattan
- Division of Gastroenterology and Hepatology, Department of Medicine, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania
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Singh J, Maxwell PJ, Rattan S. Immunocytochemical evidence for PDBu-induced activation of RhoA/ROCK in human internal anal sphincter smooth muscle cells. Am J Physiol Gastrointest Liver Physiol 2011; 301:G317-25. [PMID: 21566015 PMCID: PMC3154599 DOI: 10.1152/ajpgi.00084.2011] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Studies were performed to determine the unknown status of PKC and RhoA/ROCK in the phorbol 12,13-dibutyrate (PDBu)-stimulated state in the human internal anal sphincter (IAS) smooth muscle cells (SMCs). We determined the effects of PDBu (10(-7) M), the PKC activator, on PKCα and RhoA and ROCK II translocation in the human IAS SMCs. We used immunocytochemistry and fluorescence microcopy in the basal state, following PDBu, and before and after PKC inhibitor calphostin C (10(-6) M), cell-permeable RhoA inhibitor C3 exoenzyme (2.5 μg/ml), and ROCK inhibitor Y 27632 (10(-6) M). We also determined changes in the SMC lengths via computerized digital micrometry. In the basal state PKCα was distributed almost uniformly throughout the cell, whereas RhoA and ROCK II were located in the higher intensities toward the periphery. PDBu caused significant translocation of PKCα, RhoA, and ROCK II. PDBu-induced translocation of PKCα was attenuated by calphostin C and not by C3 exoenzyme and Y 27632. However, PDBu-induced translocation of RhoA was blocked by C3 exoenzyme, and that of ROCK II was attenuated by both C3 exoenzyme and Y 27632. Contraction of the human IAS SMCs caused by PDBu in parallel with RhoA/ROCK II translocation was attenuated by C3 exoenzyme and Y 27632 but not by calphostin C. In human IAS SMCs RhoA/ROCK compared with PKC are constitutively active, and contractility by PDBu is associated with RhoA/ROCK activation rather than PKC. The relative contribution of RhoA/ROCK vs. PKC in the pathophysiology and potential therapy for the IAS dysfunction remains to be determined.
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Affiliation(s)
- Jagmohan Singh
- Department of Medicine, Division of Gastroenterology and Hepatology, and Department of Surgery, Division of Colon and Rectal Surgery, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Pinckney J. Maxwell
- Department of Medicine, Division of Gastroenterology and Hepatology, and Department of Surgery, Division of Colon and Rectal Surgery, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Satish Rattan
- Department of Medicine, Division of Gastroenterology and Hepatology, and Department of Surgery, Division of Colon and Rectal Surgery, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania
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Chang S, Hypolite JA, Mohanan S, Zderic SA, Wein AJ, Chacko S. Alteration of the PKC-mediated signaling pathway for smooth muscle contraction in obstruction-induced hypertrophy of the urinary bladder. J Transl Med 2009; 89:823-32. [PMID: 19381130 PMCID: PMC2702459 DOI: 10.1038/labinvest.2009.38] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Normal urinary bladder function requires contraction and relaxation of the detrusor smooth muscle (DSM). The DSM undergoes compensatory hypertrophy in response to partial bladder outlet obstruction (PBOO) in both men and animal models. Following bladder hypertrophy, the bladder either retains its normal function (compensated) or becomes dysfunctional (decompensated) with increased voiding frequency and decreased void volume. We analyzed the contractile characteristics of DSM in a rabbit model of PBOO. The protein kinase C (PKC) agonist phorbol 12, 13-dibutyrate (PDBu) elicited similar levels of contraction of DSM strips from normal and compensated bladders. However, PDBu-induced contraction decreased significantly in DSM strips from decompensated bladders. The expression and activity of PKC-alpha were also lowest in decompensated bladders. The PKC-specific inhibitor bisindolylmaleimide-1 (Bis) blocked PDBu-induced contraction and PKC activity in all three groups. Moreover, the phosphorylation of the phosphoprotein inhibitor CPI-17 (a 17-kDa PKC-potentiated inhibitory protein of protein phosphatase-1) was diminished in DSM from the decompensated bladder, which would result in less inhibitory potency of CPI-17 on myosin light chain phosphatase activity and contribute to less contractility. Immunostaining revealed the colocalization of PKC and phosphorylated CPI-17 in the DSM and confirmed the decreases of these signaling proteins in the decompensated bladder. Our results show a differential PKC-mediated DSM contraction with corresponding alterations of PKC expression, activity and the phosphorylation of CPI-17. Our finding suggests a significant correlation between bladder function and PKC pathway. An impaired PKC pathway appears to be correlated with severe bladder dysfunction observed in decompensated bladders.
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Affiliation(s)
- Shaohua Chang
- Division of Urology and Department of Pathobiology, University of Pennsylvania
| | - Joseph A. Hypolite
- Division of Urology and Department of Pathobiology, University of Pennsylvania
| | - Sunish Mohanan
- Division of Urology and Department of Pathobiology, University of Pennsylvania
| | - Stephen A. Zderic
- Division of Urology and Department of Pathobiology, University of Pennsylvania
| | - Alan J. Wein
- Division of Urology and Department of Pathobiology, University of Pennsylvania
| | - Samuel Chacko
- Division of Urology and Department of Pathobiology, University of Pennsylvania
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Hypolite JA, Chang S, LaBelle E, Babu GJ, Periasamy M, Wein AJ, Chacko S. Deletion of SM-B, the high ATPase isoform of myosin, upregulates the PKC-mediated signal transduction pathway in murine urinary bladder smooth muscle. Am J Physiol Renal Physiol 2009; 296:F658-65. [PMID: 19052105 PMCID: PMC2660183 DOI: 10.1152/ajprenal.90221.2008] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2008] [Accepted: 12/01/2008] [Indexed: 01/10/2023] Open
Abstract
Detrusor smooth muscle (DSM) hypertrophy induced by partial bladder outlet obstruction (PBOO) is associated with changes in the NH2-terminal myosin heavy chain isoform from predominantly SM-B to SM-A, alteration in the Ca2+ sensitization pathway, and the contractile characteristics from phasic to tonic in rabbits. We utilized the SM-B knockout (KO) mouse to determine whether a shift from SM-B to SM-A without PBOO is associated with changes in the signal transduction pathway mediated via PKC and CPI-17, which keeps the myosin phosphorylation (MLC20) level high by inhibiting the myosin phosphatase. DSM strips from SM-B KO mice generated more force in response to electrical field stimulation, KCl, carbachol, and phorbol 12,13-dibutyrate than that of age-matched wild-type mice. There was no difference in the ED50 for carbachol but the maximum response was greater for the SM-B KO mice. DSM from SM-B KO mice revealed increased mass and hypertrophy. The KO mice also showed an overexpression of PKC-alpha, increased levels of phospho-CPI-17, and an elevated level of IP3 and DAG upon stimulation with carbachol. Two-dimensional gel electrophoresis revealed an increased level of MLC20 phosphorylation in response to carbachol. Together, these changes may be responsible for the higher level of force generation and maintenance by the DSM from the SM-B KO bladders. In conclusion, our data show that ablation of SM-B is associated with alteration of PKC-mediated signal transduction and CPI-17-mediated Ca2+ sensitization pathway that regulate smooth muscle contraction. Interestingly, similar changes are also present in PBOO-induced DSM compensatory response in the rabbit model in which SM-B is downregulated.
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Affiliation(s)
- Joseph A Hypolite
- Division of Urology and Department of Pathobiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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