U-73122, a phospholipase C antagonist, inhibits effects of endothelin-1 and parathyroid hormone on signal transduction in UMR-106 osteoblastic cells

Tatrai, Agnes; Suk, Kyeong Lee; Stern, Paula H.

doi:10.1016/0167-4889(94)90296-8

Cited by 41 publications

(16 citation statements)

References 32 publications

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“…Neomycin is a potent PLC inhibitor but it also affects the activity of PLD [38]. The present study demonstrates that neomycin and U73122, a selective PLC inhibitor [39], completely blocked thrombin-induced PAI-1 generation in BASMC. Our results suggest that the activation of PLC is required for the generation of PAI-1 in SMC.…”

Section: Discussionmentioning

confidence: 54%

G Proteins and Phospholipase C Mediate Thrombin-lnduced Generation of Plasminogen Activator Inhibitor-1 from Vascular Smooth Muscle Cells

Ren

Cockell²,

Fenton³

et al. 1997

J Vasc Res

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The present study investigated transcellular signalling mechanism involved in thrombin-induced production of plasminogen activator inhibitor-1 (PAI-1) in cultured vascular baboon aortic smooth muscle cells (BASMC). Treatments with thrombin dose-dependently increased the steady state levels of PAI-1 mRNA and the generation of PAI-1 antigen from BASMC. Thrombin receptor-activating peptide mimicked the effect of thrombin on the generation of PAI-1. Sodium fluoride (1 mM) stimulated PAI-1 generation from BASMC. Pertussis toxin dose-dependently suppressed thrombin-induced increase of PAI-1 generation. Treatment with 5 mM neomycin, 10 µM U73122 or 1 µM calphostin C blocked thrombin-induced PAI-1 generation. Phorbol myristate acetate at 10 nM for 3 h strongly stimulated the generation of PAI-1 from BASMC. Forskolin (100 µM)or 8-bromo-cAMP (100 µM)suppressed thrombin-induced PAI-1 generation. The responses of quiescent BASMC to thrombin or the inhibitors on PAI-1 generation were comparable to that of growing cells. The results of the present study suggest that pertussis toxin-sensitive G proteins and a phospholipase C are involved in thrombin-induced generation of PAI-1 in BASMC, which may transmit signals from occupied thrombin receptor to protein kinase C and thereby increase the generation of PAI-1. Elevated levels of intracellular cAMP may negatively regulate the generation of PAI-1 from vascular SMC.

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Section: Discussionmentioning

confidence: 54%

G Proteins and Phospholipase C Mediate Thrombin-lnduced Generation of Plasminogen Activator Inhibitor-1 from Vascular Smooth Muscle Cells

Ren

Cockell²,

Fenton³

et al. 1997

J Vasc Res

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“…In this study, three phospholipase C inhibitors, lithium, U73122, and neomycin, exerted strong inhibition on cercosporin production. U73122 inhibits the coupling of G protein to phospholipase C, thus blocking the hydrolysis of PIP2 to IP3 (38). Excess CaCl 2 only partially reversed lithium inhibition of cercosporin production, likely due to the multiple activities of lithium.…”

Section: Discussionmentioning

confidence: 99%

Involvement of Calcium/Calmodulin Signaling in Cercosporin Toxin Biosynthesis byCercosporanicotianae

Chung

2003

Appl Environ Microbiol

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Cercosporin is a non-host-selective, perylenequinone toxin produced by many phytopathogenic Cercospora species. The involvement of Ca 2؉ /calmodulin (CaM) signaling in cercosporin biosynthesis was investigated by using pharmacological inhibitors. The results suggest that maintaining endogenous Ca 2؉ homeostasis is required for cercosporin biosynthesis in Cercospora nicotianae. The addition of excess Ca 2؉ to the medium slightly increased fungal growth but resulted in a reduction in cercosporin production. The addition of Ca

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“…Great attention has been given to the wide number of signal transduction pathways acting in osteoblasts, which coordinate and regulate osteoblasts' complex contribution to bone remodeling. Various signal transduction pathways occurring in osteoblasts have been actively studied (39)(40)(41)(42)(43), with special regard to the systems related to complex calcium metabolism (44).…”

Section: Discussionmentioning

confidence: 99%

Comparison of Phosphoinositide-Specific Phospholipase C Expression Panels of Human Osteoblasts Versus MG-63 and Saos Osteoblast-Like Cells

Vasco¹,

Leopizzi²,

d’Abusco³

et al. 2016

Avicenna J Med Biochem

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Background: A large number of phospholipase C (PLC) enzymes, both mRNA transcripts and proteins, have been detected in osteoblasts, corroborating the importance of calcium regulation in bone tissue. MG-63 and SaOS-2 human osteosarcoma cell lines are actually considered osteoblast-like cells, and are therefore widely used as experimental models for osteoblasts. Objectives: Our aim was to verify whether MG-63 or SaOS-2 cells might also represent appropriate experimental osteoblast models for signal transduction studies, with special regard to the phosphoinositide (PI) pathway. We analyzed the expression and the subcellular distribution of enzymes related to calcium signal transduction (the PI-specific PLC family), which are known to possess high cell/tissue specificity. Materials and Methods:The expression of PLC genes was analyzed by performing RT-PCR experiments. The presence of PLC enzymes and their subcellular distribution within the cells was analyzed with immunofluorescence experiments. Results: Osteoblasts, MG-63 cells, and SaOS-2 cells have expression panels similar to those of PLC enzymes. However, slight differences were found in the expression of enzymes belonging to the PLCη subfamily. Conclusions: MG-63 and SaOS-2 osteosarcoma cell lines might not represent appropriate experimental models for studies that aim to analyze signal transduction in osteoblasts.

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U-73122, a phospholipase C antagonist, inhibits effects of endothelin-1 and parathyroid hormone on signal transduction in UMR-106 osteoblastic cells

Cited by 41 publications

References 32 publications

G Proteins and Phospholipase C Mediate Thrombin-lnduced Generation of Plasminogen Activator Inhibitor-1 from Vascular Smooth Muscle Cells

G Proteins and Phospholipase C Mediate Thrombin-lnduced Generation of Plasminogen Activator Inhibitor-1 from Vascular Smooth Muscle Cells

Involvement of Calcium/Calmodulin Signaling in Cercosporin Toxin Biosynthesis byCercosporanicotianae

Comparison of Phosphoinositide-Specific Phospholipase C Expression Panels of Human Osteoblasts Versus MG-63 and Saos Osteoblast-Like Cells

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