The Experts below are selected from a list of 285 Experts worldwide ranked by ideXlab platform
Karnam S. Murthy - One of the best experts on this subject based on the ideXlab platform.
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Changes in the expression of smooth Muscle contractile proteins in TNBS- and DSS-induced colitis in mice.
Inflammation, 2013Co-Authors: Reem Alkahtani, Sunila Mahavadi, John R. Grider, Othman Al-shboul, Shakir D. Alsharari, Karnam S. MurthyAbstract:Thin filament-associated proteins such as calponin, caldesmon, tropomyosin, and smoothelin are thought to regulate acto-myosin interaction and thus, Muscle contraction. However, the effect of inflammation on the expression of thin filament-associated proteins is not known. The aim of the present study is to determine the changes in the expression of calponin, caldesmon, tropomyosin, and smoothelin in Colonic smooth Muscle from trinitrobenzene sulphonic acid (TNBS)- and dextran sodium sulphate (DSS)-induced colitis in mice. Expression of h-caldesmon, h2-calponin, α-tropomyosin, and smoothelin-A was measured by qRT-PCR and Western blot. Contraction in response to acetylcholine in dispersed Muscle cells was measured by scanning micrometry. mRNA and protein expression of α-actin, h2-calponin, h-caldesmon, smoothelin, and α-tropomyosin in Colonic Muscle strips from mice with TNBS- or DSS-induced colitis was significantly increased compared to control animals. Contraction in response to acetylcholine was significantly decreased in Muscle cells isolated from inflamed regions of TNBS- or DSS-treated mice compared to control mice. Our results show that increase in the expression of thin filament-associated contractile proteins, which inhibit acto-myosin interaction, could contribute to decrease in smooth Muscle contraction in inflammation.
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interleukin 1β up regulates rgs4 through the canonical ikk2 iκbα nf κb pathway in rabbit Colonic smooth Muscle
Biochemical Journal, 2008Co-Authors: Wenhui Hu, Sunila Mahavadi, Fang Li, Karnam S. MurthyAbstract:Initial Ca2+-dependent contraction of the intestinal smooth Muscle mediated by Gq-coupled receptors is attenuated by RGS4 (regulator of G-protein signalling 4). Treatment of Colonic Muscle cells with IL-1β (interleukin-1β) inhibits acetylcholine-stimulated initial contraction through increasing the expression of RGS4. NF-κB (nuclear factor κB) signalling is the dominant pathway activated by IL-1β. In the present study we show that RGS4 is a new target gene regulated by IL-1β/NF-κB signalling. Exposure of cultured rabbit Colonic Muscle cells to IL-1β induced a rapid increase in RGS4 mRNA expression, which was abolished by pretreatment with a transcription inhibitor, actinomycin D, implying a transcription-dependent mechanism. Existence of the canonical IKK2 [IκB (inhibitor of NF-κB) kinase 2]/IκBα pathway of NF-κB activation induced by IL-1β in rabbit Colonic Muscle cells was validated with multiple approaches, including the induction of reporter luciferase activity and endogenous NF-κB-target gene expression, NF-κB-DNA binding activity, p65 nuclear translocation, IκBα degradation and the phosphorylation of IKK2 at Ser177/181 and p65 at Ser536. RGS4 up-regulation by IL-1β was blocked by selective inhibitors of IKK2, IκBα or NF-κB activation, by effective siRNA (small interfering RNA) of IKK2, and in cells expressing either the kinase-inactive IKK2 mutant (K44A) or the phosphorylation-deficient IκBα mutant (S32A/S36A). An IKK2-specific inhibitor or effective siRNA prevented IL-1β-induced inhibition of acetylcholine-stimulated PLC-β (phopsholipase C-β) activation. These results suggest that the canonical IKK2/IκBα pathway of NF-κB activation mediates the up-regulation of RGS4 expression in response to IL-1β and contributes to the inhibitory effect of IL-1β on acetylcholine-stimulated PLC-β-dependent initial contraction in rabbit Colonic smooth Muscle.
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Interleukin-1β up-regulates RGS4 through the canonical IKK2/IκBα/NF-κB pathway in rabbit Colonic smooth Muscle
Biochemical Journal, 2008Co-Authors: Wenhui Hu, Sunila Mahavadi, Fang Li, Karnam S. MurthyAbstract:Initial Ca2+-dependent contraction of the intestinal smooth Muscle mediated by Gq-coupled receptors is attenuated by RGS4 (regulator of G-protein signalling 4). Treatment of Colonic Muscle cells with IL-1β (interleukin-1β) inhibits acetylcholine-stimulated initial contraction through increasing the expression of RGS4. NF-κB (nuclear factor κB) signalling is the dominant pathway activated by IL-1β. In the present study we show that RGS4 is a new target gene regulated by IL-1β/NF-κB signalling. Exposure of cultured rabbit Colonic Muscle cells to IL-1β induced a rapid increase in RGS4 mRNA expression, which was abolished by pretreatment with a transcription inhibitor, actinomycin D, implying a transcription-dependent mechanism. Existence of the canonical IKK2 [IκB (inhibitor of NF-κB) kinase 2]/IκBα pathway of NF-κB activation induced by IL-1β in rabbit Colonic Muscle cells was validated with multiple approaches, including the induction of reporter luciferase activity and endogenous NF-κB-target gene expression, NF-κB-DNA binding activity, p65 nuclear translocation, IκBα degradation and the phosphorylation of IKK2 at Ser177/181 and p65 at Ser536. RGS4 up-regulation by IL-1β was blocked by selective inhibitors of IKK2, IκBα or NF-κB activation, by effective siRNA (small interfering RNA) of IKK2, and in cells expressing either the kinase-inactive IKK2 mutant (K44A) or the phosphorylation-deficient IκBα mutant (S32A/S36A). An IKK2-specific inhibitor or effective siRNA prevented IL-1β-induced inhibition of acetylcholine-stimulated PLC-β (phopsholipase C-β) activation. These results suggest that the canonical IKK2/IκBα pathway of NF-κB activation mediates the up-regulation of RGS4 expression in response to IL-1β and contributes to the inhibitory effect of IL-1β on acetylcholine-stimulated PLC-β-dependent initial contraction in rabbit Colonic smooth Muscle.
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Interleukin-1β up-regulates RGS4 through the canonical IKK2/IκBα/NF-κB pathway in rabbit Colonic smooth Muscle
Biochemical Journal, 2008Co-Authors: Wenhui Hu, Sunila Mahavadi, Fang Li, Karnam S. MurthyAbstract:Initial Ca2+-dependent contraction of the intestinal smooth Muscle mediated by Gq-coupled receptors is attenuated by RGS4 (regulator of G-protein signalling 4). Treatment of Colonic Muscle cells with IL-1β (interleukin-1β) inhibits acetylcholine-stimulated initial contraction through increasing the expression of RGS4. NF-κB (nuclear factor κB) signalling is the dominant pathway activated by IL-1β. In the present study we show that RGS4 is a new target gene regulated by IL-1β/NF-κB signalling. Exposure of cultured rabbit Colonic Muscle cells to IL-1β induced a rapid increase in RGS4 mRNA expression, which was abolished by pretreatment with a transcription inhibitor, actinomycin D, implying a transcription-dependent mechanism. Existence of the canonical IKK2 [IκB (inhibitor of NF-κB) kinase 2]/IκBα pathway of NF-κB activation induced by IL-1β in rabbit Colonic Muscle cells was validated with multiple approaches, including the induction of reporter luciferase activity and endogenous NF-κB-target gene expression, NF-κB-DNA binding activity, p65 nuclear translocation, IκBα degradation and the phosphorylation of IKK2 at Ser177/181 and p65 at Ser536. RGS4 up-regulation by IL-1β was blocked by selective inhibitors of IKK2, IκBα or NF-κB activation, by effective siRNA (small interfering RNA) of IKK2, and in cells expressing either the kinase-inactive IKK2 mutant (K44A) or the phosphorylation-deficient IκBα mutant (S32A/S36A). An IKK2-specific inhibitor or effective siRNA prevented IL-1β-induced inhibition of acetylcholine-stimulated PLC-β (phopsholipase C-β) activation. These results suggest that the canonical IKK2/IκBα pathway of NF-κB activation mediates the up-regulation of RGS4 expression in response to IL-1β and contributes to the inhibitory effect of IL-1β on acetylcholine-stimulated PLC-β-dependent initial contraction in rabbit Colonic smooth Muscle.
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interleukin 1beta up regulates rgs4 through the canonical ikk2 ikappabalpha nf kappab pathway in rabbit Colonic smooth Muscle
Biochemical Journal, 2008Co-Authors: Sunila Mahavadi, Karnam S. MurthyAbstract:Initial Ca2+-dependent contraction of the intestinal smooth Muscle mediated by G(q)-coupled receptors is attenuated by RGS4 (regulator of G-protein signalling 4). Treatment of Colonic Muscle cells with IL-1beta (interleukin-1beta) inhibits acetylcholine-stimulated initial contraction through increasing the expression of RGS4. NF-kappaB (nuclear factor kappaB) signalling is the dominant pathway activated by IL-1beta. In the present study we show that RGS4 is a new target gene regulated by IL-1beta/NF-kappaB signalling. Exposure of cultured rabbit Colonic Muscle cells to IL-1beta induced a rapid increase in RGS4 mRNA expression, which was abolished by pretreatment with a transcription inhibitor, actinomycin D, implying a transcription-dependent mechanism. Existence of the canonical IKK2 [IkappaB (inhibitor of NF-kappaB) kinase 2]/IkappaBalpha pathway of NF-kappaB activation induced by IL-1beta in rabbit Colonic Muscle cells was validated with multiple approaches, including the induction of reporter luciferase activity and endogenous NF-kappaB-target gene expression, NF-kappaB-DNA binding activity, p65 nuclear translocation, IkappaBalpha degradation and the phosphorylation of IKK2 at Ser(177/181) and p65 at Ser(536). RGS4 up-regulation by IL-1beta was blocked by selective inhibitors of IKK2, IkappaBalpha or NF-kappaB activation, by effective siRNA (small interfering RNA) of IKK2, and in cells expressing either the kinase-inactive IKK2 mutant (K44A) or the phosphorylation-deficient IkappaBalpha mutant (S32A/S36A). An IKK2-specific inhibitor or effective siRNA prevented IL-1beta-induced inhibition of acetylcholine-stimulated PLC-beta (phopsholipase C-beta) activation. These results suggest that the canonical IKK2/IkappaBalpha pathway of NF-kappaB activation mediates the up-regulation of RGS4 expression in response to IL-1beta and contributes to the inhibitory effect of IL-1beta on acetylcholine-stimulated PLC-beta-dependent initial contraction in rabbit Colonic smooth Muscle.
Sunila Mahavadi - One of the best experts on this subject based on the ideXlab platform.
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Changes in the expression of smooth Muscle contractile proteins in TNBS- and DSS-induced colitis in mice.
Inflammation, 2013Co-Authors: Reem Alkahtani, Sunila Mahavadi, John R. Grider, Othman Al-shboul, Shakir D. Alsharari, Karnam S. MurthyAbstract:Thin filament-associated proteins such as calponin, caldesmon, tropomyosin, and smoothelin are thought to regulate acto-myosin interaction and thus, Muscle contraction. However, the effect of inflammation on the expression of thin filament-associated proteins is not known. The aim of the present study is to determine the changes in the expression of calponin, caldesmon, tropomyosin, and smoothelin in Colonic smooth Muscle from trinitrobenzene sulphonic acid (TNBS)- and dextran sodium sulphate (DSS)-induced colitis in mice. Expression of h-caldesmon, h2-calponin, α-tropomyosin, and smoothelin-A was measured by qRT-PCR and Western blot. Contraction in response to acetylcholine in dispersed Muscle cells was measured by scanning micrometry. mRNA and protein expression of α-actin, h2-calponin, h-caldesmon, smoothelin, and α-tropomyosin in Colonic Muscle strips from mice with TNBS- or DSS-induced colitis was significantly increased compared to control animals. Contraction in response to acetylcholine was significantly decreased in Muscle cells isolated from inflamed regions of TNBS- or DSS-treated mice compared to control mice. Our results show that increase in the expression of thin filament-associated contractile proteins, which inhibit acto-myosin interaction, could contribute to decrease in smooth Muscle contraction in inflammation.
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interleukin 1β up regulates rgs4 through the canonical ikk2 iκbα nf κb pathway in rabbit Colonic smooth Muscle
Biochemical Journal, 2008Co-Authors: Wenhui Hu, Sunila Mahavadi, Fang Li, Karnam S. MurthyAbstract:Initial Ca2+-dependent contraction of the intestinal smooth Muscle mediated by Gq-coupled receptors is attenuated by RGS4 (regulator of G-protein signalling 4). Treatment of Colonic Muscle cells with IL-1β (interleukin-1β) inhibits acetylcholine-stimulated initial contraction through increasing the expression of RGS4. NF-κB (nuclear factor κB) signalling is the dominant pathway activated by IL-1β. In the present study we show that RGS4 is a new target gene regulated by IL-1β/NF-κB signalling. Exposure of cultured rabbit Colonic Muscle cells to IL-1β induced a rapid increase in RGS4 mRNA expression, which was abolished by pretreatment with a transcription inhibitor, actinomycin D, implying a transcription-dependent mechanism. Existence of the canonical IKK2 [IκB (inhibitor of NF-κB) kinase 2]/IκBα pathway of NF-κB activation induced by IL-1β in rabbit Colonic Muscle cells was validated with multiple approaches, including the induction of reporter luciferase activity and endogenous NF-κB-target gene expression, NF-κB-DNA binding activity, p65 nuclear translocation, IκBα degradation and the phosphorylation of IKK2 at Ser177/181 and p65 at Ser536. RGS4 up-regulation by IL-1β was blocked by selective inhibitors of IKK2, IκBα or NF-κB activation, by effective siRNA (small interfering RNA) of IKK2, and in cells expressing either the kinase-inactive IKK2 mutant (K44A) or the phosphorylation-deficient IκBα mutant (S32A/S36A). An IKK2-specific inhibitor or effective siRNA prevented IL-1β-induced inhibition of acetylcholine-stimulated PLC-β (phopsholipase C-β) activation. These results suggest that the canonical IKK2/IκBα pathway of NF-κB activation mediates the up-regulation of RGS4 expression in response to IL-1β and contributes to the inhibitory effect of IL-1β on acetylcholine-stimulated PLC-β-dependent initial contraction in rabbit Colonic smooth Muscle.
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Interleukin-1β up-regulates RGS4 through the canonical IKK2/IκBα/NF-κB pathway in rabbit Colonic smooth Muscle
Biochemical Journal, 2008Co-Authors: Wenhui Hu, Sunila Mahavadi, Fang Li, Karnam S. MurthyAbstract:Initial Ca2+-dependent contraction of the intestinal smooth Muscle mediated by Gq-coupled receptors is attenuated by RGS4 (regulator of G-protein signalling 4). Treatment of Colonic Muscle cells with IL-1β (interleukin-1β) inhibits acetylcholine-stimulated initial contraction through increasing the expression of RGS4. NF-κB (nuclear factor κB) signalling is the dominant pathway activated by IL-1β. In the present study we show that RGS4 is a new target gene regulated by IL-1β/NF-κB signalling. Exposure of cultured rabbit Colonic Muscle cells to IL-1β induced a rapid increase in RGS4 mRNA expression, which was abolished by pretreatment with a transcription inhibitor, actinomycin D, implying a transcription-dependent mechanism. Existence of the canonical IKK2 [IκB (inhibitor of NF-κB) kinase 2]/IκBα pathway of NF-κB activation induced by IL-1β in rabbit Colonic Muscle cells was validated with multiple approaches, including the induction of reporter luciferase activity and endogenous NF-κB-target gene expression, NF-κB-DNA binding activity, p65 nuclear translocation, IκBα degradation and the phosphorylation of IKK2 at Ser177/181 and p65 at Ser536. RGS4 up-regulation by IL-1β was blocked by selective inhibitors of IKK2, IκBα or NF-κB activation, by effective siRNA (small interfering RNA) of IKK2, and in cells expressing either the kinase-inactive IKK2 mutant (K44A) or the phosphorylation-deficient IκBα mutant (S32A/S36A). An IKK2-specific inhibitor or effective siRNA prevented IL-1β-induced inhibition of acetylcholine-stimulated PLC-β (phopsholipase C-β) activation. These results suggest that the canonical IKK2/IκBα pathway of NF-κB activation mediates the up-regulation of RGS4 expression in response to IL-1β and contributes to the inhibitory effect of IL-1β on acetylcholine-stimulated PLC-β-dependent initial contraction in rabbit Colonic smooth Muscle.
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Interleukin-1β up-regulates RGS4 through the canonical IKK2/IκBα/NF-κB pathway in rabbit Colonic smooth Muscle
Biochemical Journal, 2008Co-Authors: Wenhui Hu, Sunila Mahavadi, Fang Li, Karnam S. MurthyAbstract:Initial Ca2+-dependent contraction of the intestinal smooth Muscle mediated by Gq-coupled receptors is attenuated by RGS4 (regulator of G-protein signalling 4). Treatment of Colonic Muscle cells with IL-1β (interleukin-1β) inhibits acetylcholine-stimulated initial contraction through increasing the expression of RGS4. NF-κB (nuclear factor κB) signalling is the dominant pathway activated by IL-1β. In the present study we show that RGS4 is a new target gene regulated by IL-1β/NF-κB signalling. Exposure of cultured rabbit Colonic Muscle cells to IL-1β induced a rapid increase in RGS4 mRNA expression, which was abolished by pretreatment with a transcription inhibitor, actinomycin D, implying a transcription-dependent mechanism. Existence of the canonical IKK2 [IκB (inhibitor of NF-κB) kinase 2]/IκBα pathway of NF-κB activation induced by IL-1β in rabbit Colonic Muscle cells was validated with multiple approaches, including the induction of reporter luciferase activity and endogenous NF-κB-target gene expression, NF-κB-DNA binding activity, p65 nuclear translocation, IκBα degradation and the phosphorylation of IKK2 at Ser177/181 and p65 at Ser536. RGS4 up-regulation by IL-1β was blocked by selective inhibitors of IKK2, IκBα or NF-κB activation, by effective siRNA (small interfering RNA) of IKK2, and in cells expressing either the kinase-inactive IKK2 mutant (K44A) or the phosphorylation-deficient IκBα mutant (S32A/S36A). An IKK2-specific inhibitor or effective siRNA prevented IL-1β-induced inhibition of acetylcholine-stimulated PLC-β (phopsholipase C-β) activation. These results suggest that the canonical IKK2/IκBα pathway of NF-κB activation mediates the up-regulation of RGS4 expression in response to IL-1β and contributes to the inhibitory effect of IL-1β on acetylcholine-stimulated PLC-β-dependent initial contraction in rabbit Colonic smooth Muscle.
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interleukin 1beta up regulates rgs4 through the canonical ikk2 ikappabalpha nf kappab pathway in rabbit Colonic smooth Muscle
Biochemical Journal, 2008Co-Authors: Sunila Mahavadi, Karnam S. MurthyAbstract:Initial Ca2+-dependent contraction of the intestinal smooth Muscle mediated by G(q)-coupled receptors is attenuated by RGS4 (regulator of G-protein signalling 4). Treatment of Colonic Muscle cells with IL-1beta (interleukin-1beta) inhibits acetylcholine-stimulated initial contraction through increasing the expression of RGS4. NF-kappaB (nuclear factor kappaB) signalling is the dominant pathway activated by IL-1beta. In the present study we show that RGS4 is a new target gene regulated by IL-1beta/NF-kappaB signalling. Exposure of cultured rabbit Colonic Muscle cells to IL-1beta induced a rapid increase in RGS4 mRNA expression, which was abolished by pretreatment with a transcription inhibitor, actinomycin D, implying a transcription-dependent mechanism. Existence of the canonical IKK2 [IkappaB (inhibitor of NF-kappaB) kinase 2]/IkappaBalpha pathway of NF-kappaB activation induced by IL-1beta in rabbit Colonic Muscle cells was validated with multiple approaches, including the induction of reporter luciferase activity and endogenous NF-kappaB-target gene expression, NF-kappaB-DNA binding activity, p65 nuclear translocation, IkappaBalpha degradation and the phosphorylation of IKK2 at Ser(177/181) and p65 at Ser(536). RGS4 up-regulation by IL-1beta was blocked by selective inhibitors of IKK2, IkappaBalpha or NF-kappaB activation, by effective siRNA (small interfering RNA) of IKK2, and in cells expressing either the kinase-inactive IKK2 mutant (K44A) or the phosphorylation-deficient IkappaBalpha mutant (S32A/S36A). An IKK2-specific inhibitor or effective siRNA prevented IL-1beta-induced inhibition of acetylcholine-stimulated PLC-beta (phopsholipase C-beta) activation. These results suggest that the canonical IKK2/IkappaBalpha pathway of NF-kappaB activation mediates the up-regulation of RGS4 expression in response to IL-1beta and contributes to the inhibitory effect of IL-1beta on acetylcholine-stimulated PLC-beta-dependent initial contraction in rabbit Colonic smooth Muscle.
Wenhui Hu - One of the best experts on this subject based on the ideXlab platform.
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interleukin 1β up regulates rgs4 through the canonical ikk2 iκbα nf κb pathway in rabbit Colonic smooth Muscle
Biochemical Journal, 2008Co-Authors: Wenhui Hu, Sunila Mahavadi, Fang Li, Karnam S. MurthyAbstract:Initial Ca2+-dependent contraction of the intestinal smooth Muscle mediated by Gq-coupled receptors is attenuated by RGS4 (regulator of G-protein signalling 4). Treatment of Colonic Muscle cells with IL-1β (interleukin-1β) inhibits acetylcholine-stimulated initial contraction through increasing the expression of RGS4. NF-κB (nuclear factor κB) signalling is the dominant pathway activated by IL-1β. In the present study we show that RGS4 is a new target gene regulated by IL-1β/NF-κB signalling. Exposure of cultured rabbit Colonic Muscle cells to IL-1β induced a rapid increase in RGS4 mRNA expression, which was abolished by pretreatment with a transcription inhibitor, actinomycin D, implying a transcription-dependent mechanism. Existence of the canonical IKK2 [IκB (inhibitor of NF-κB) kinase 2]/IκBα pathway of NF-κB activation induced by IL-1β in rabbit Colonic Muscle cells was validated with multiple approaches, including the induction of reporter luciferase activity and endogenous NF-κB-target gene expression, NF-κB-DNA binding activity, p65 nuclear translocation, IκBα degradation and the phosphorylation of IKK2 at Ser177/181 and p65 at Ser536. RGS4 up-regulation by IL-1β was blocked by selective inhibitors of IKK2, IκBα or NF-κB activation, by effective siRNA (small interfering RNA) of IKK2, and in cells expressing either the kinase-inactive IKK2 mutant (K44A) or the phosphorylation-deficient IκBα mutant (S32A/S36A). An IKK2-specific inhibitor or effective siRNA prevented IL-1β-induced inhibition of acetylcholine-stimulated PLC-β (phopsholipase C-β) activation. These results suggest that the canonical IKK2/IκBα pathway of NF-κB activation mediates the up-regulation of RGS4 expression in response to IL-1β and contributes to the inhibitory effect of IL-1β on acetylcholine-stimulated PLC-β-dependent initial contraction in rabbit Colonic smooth Muscle.
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Interleukin-1β up-regulates RGS4 through the canonical IKK2/IκBα/NF-κB pathway in rabbit Colonic smooth Muscle
Biochemical Journal, 2008Co-Authors: Wenhui Hu, Sunila Mahavadi, Fang Li, Karnam S. MurthyAbstract:Initial Ca2+-dependent contraction of the intestinal smooth Muscle mediated by Gq-coupled receptors is attenuated by RGS4 (regulator of G-protein signalling 4). Treatment of Colonic Muscle cells with IL-1β (interleukin-1β) inhibits acetylcholine-stimulated initial contraction through increasing the expression of RGS4. NF-κB (nuclear factor κB) signalling is the dominant pathway activated by IL-1β. In the present study we show that RGS4 is a new target gene regulated by IL-1β/NF-κB signalling. Exposure of cultured rabbit Colonic Muscle cells to IL-1β induced a rapid increase in RGS4 mRNA expression, which was abolished by pretreatment with a transcription inhibitor, actinomycin D, implying a transcription-dependent mechanism. Existence of the canonical IKK2 [IκB (inhibitor of NF-κB) kinase 2]/IκBα pathway of NF-κB activation induced by IL-1β in rabbit Colonic Muscle cells was validated with multiple approaches, including the induction of reporter luciferase activity and endogenous NF-κB-target gene expression, NF-κB-DNA binding activity, p65 nuclear translocation, IκBα degradation and the phosphorylation of IKK2 at Ser177/181 and p65 at Ser536. RGS4 up-regulation by IL-1β was blocked by selective inhibitors of IKK2, IκBα or NF-κB activation, by effective siRNA (small interfering RNA) of IKK2, and in cells expressing either the kinase-inactive IKK2 mutant (K44A) or the phosphorylation-deficient IκBα mutant (S32A/S36A). An IKK2-specific inhibitor or effective siRNA prevented IL-1β-induced inhibition of acetylcholine-stimulated PLC-β (phopsholipase C-β) activation. These results suggest that the canonical IKK2/IκBα pathway of NF-κB activation mediates the up-regulation of RGS4 expression in response to IL-1β and contributes to the inhibitory effect of IL-1β on acetylcholine-stimulated PLC-β-dependent initial contraction in rabbit Colonic smooth Muscle.
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Interleukin-1β up-regulates RGS4 through the canonical IKK2/IκBα/NF-κB pathway in rabbit Colonic smooth Muscle
Biochemical Journal, 2008Co-Authors: Wenhui Hu, Sunila Mahavadi, Fang Li, Karnam S. MurthyAbstract:Initial Ca2+-dependent contraction of the intestinal smooth Muscle mediated by Gq-coupled receptors is attenuated by RGS4 (regulator of G-protein signalling 4). Treatment of Colonic Muscle cells with IL-1β (interleukin-1β) inhibits acetylcholine-stimulated initial contraction through increasing the expression of RGS4. NF-κB (nuclear factor κB) signalling is the dominant pathway activated by IL-1β. In the present study we show that RGS4 is a new target gene regulated by IL-1β/NF-κB signalling. Exposure of cultured rabbit Colonic Muscle cells to IL-1β induced a rapid increase in RGS4 mRNA expression, which was abolished by pretreatment with a transcription inhibitor, actinomycin D, implying a transcription-dependent mechanism. Existence of the canonical IKK2 [IκB (inhibitor of NF-κB) kinase 2]/IκBα pathway of NF-κB activation induced by IL-1β in rabbit Colonic Muscle cells was validated with multiple approaches, including the induction of reporter luciferase activity and endogenous NF-κB-target gene expression, NF-κB-DNA binding activity, p65 nuclear translocation, IκBα degradation and the phosphorylation of IKK2 at Ser177/181 and p65 at Ser536. RGS4 up-regulation by IL-1β was blocked by selective inhibitors of IKK2, IκBα or NF-κB activation, by effective siRNA (small interfering RNA) of IKK2, and in cells expressing either the kinase-inactive IKK2 mutant (K44A) or the phosphorylation-deficient IκBα mutant (S32A/S36A). An IKK2-specific inhibitor or effective siRNA prevented IL-1β-induced inhibition of acetylcholine-stimulated PLC-β (phopsholipase C-β) activation. These results suggest that the canonical IKK2/IκBα pathway of NF-κB activation mediates the up-regulation of RGS4 expression in response to IL-1β and contributes to the inhibitory effect of IL-1β on acetylcholine-stimulated PLC-β-dependent initial contraction in rabbit Colonic smooth Muscle.
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upregulation of rgs4 and downregulation of cpi 17 mediate inhibition of Colonic Muscle contraction by interleukin 1β
American Journal of Physiology-cell Physiology, 2007Co-Authors: Wenhui Hu, Sunila Mahavadi, Fang Li, Karnam S. MurthyAbstract:The pro-inflammatory cytokine IL-1β contributes to the reduced contractile responses of gut smooth Muscle observed in both animal colitis models and human inflammatory bowel diseases. However, the ...
He-sheng Luo - One of the best experts on this subject based on the ideXlab platform.
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Evodiamine inhibits gastrointestinal motility via CCK and CCK1 receptor in water-avoidence stress rat model.
Life sciences, 2018Co-Authors: Haixia Ren, Qincai Tang, Lin Yan, Hao Xia, He-sheng LuoAbstract:Abstract AIM Evodiamine (EVO) has been reported to play an important role in regulating gastrointestinal motility, but the evidence is insufficient, and the mechanism remains unknown. The aim of this study is to investigate the possible role of EVO in stress-induced Colonic hypermotility and the potential mechanisms via both in vivo and in vitro investigations. Methods Male Sprague–Dawley rats were exposed to water avoidance stress (WAS) for 1 h or sham WAS daily for 10 consecutive days to construct the rat model. The Colonic contractile activity was studied in an organ bath system. The serum CCK-8 level was detected using an enzyme immunoassay kit, and gastrointestinal transit was detected by intragastric administration of India ink. Results WAS induced gastrointestinal hypermotility in male rats. EVO significantly inhibited the contractile activity of Colonic Muscle strips; this effect was not blocked by TTX and the CCK1 receptor antagonist devazepide. Chronic WAS induced a slight but nonsignificant increase in the serum CCK-8 level, while EVO elevated the serum CCK-8 level in the WAS rats in a dose-dependent manner. Exogenous CCK-8 significantly inhibited the contractile activity of the Colonic Muscle strips; this effect was not blocked by TTX but was completely blocked by devazepide. Both EVO and CCK-8 inhibited gastrointestinal transit, and the effect of EVO could be partially blocked by devazepide. Significance EVO can reverse stress-induced gastrointestinal hypermotility. This effect may partially occur as a result of promoting the release of CCK and then activating the CCK1 receptor instead of directly activating the CCK1 receptor.
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Diallyl trisulfide regulates rat Colonic smooth Muscle contractions by inhibiting L-type calcium channel currents.
Journal of pharmacological sciences, 2018Co-Authors: Qincai Tang, Haixia Ren, Lin Yan, Xiaojing Quan, Hong Xia, He-sheng LuoAbstract:Abstract Diallyl trisulfide (DATS) is an active organosulfide component of allicin and has several beneficial effects, including antimicrobial, antioxidant, cardioprotective and anticancer effects. Few studies have shown the modulatory effect of DATS on L-type calcium channels in rat Colonic smooth Muscle cells and Colonic motility. To investigate the modulatory effect of DATS on L-type calcium channels in rat Colonic smooth Muscle and Colonic contraction, L-type calcium channel currents were recorded, and Colonic contractility in longitudinal and circular smooth Muscle strips was measured. DATS attenuated L-type calcium channel currents without affecting steady-state activation or inactivation kinetics and inhibited the spontaneous contractions of both longitudinal and circular smooth Muscle strips dose-dependently. In conclusion, DATS has an inhibitory effect on the contractions of Colonic Muscle strips that is related to its regulation of L-type calcium channels.
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Brain-Derived Neurotrophic Factor Contributes to Colonic Hypermotility in a Chronic Stress Rat Model
Digestive diseases and sciences, 2015Co-Authors: Xiaojing Quan, Qincai Tang, He-sheng Luo, Han Fan, Wei Chen, Ning Cui, Hong XiaAbstract:Brain-derived neurotrophic factor (BDNF) has prokinetic effects on gut motility and is increased in the Colonic mucosa of irritable bowel syndrome. We aimed to investigate the possible involvement of BDNF in stress-induced Colonic hypermotility. Male Wistar rats were exposed to daily 1-h water avoidance stress (WAS) or sham WAS for 10 consecutive days. The presence of BDNF and substance P (SP) in the Colonic mucosa was determined using enzyme immunoassay kits. Immunohistochemistry and western blotting were performed to assess the expression of BDNF and its receptor, TrkB. The contractions of Muscle strips were studied in an organ bath system. Repeated WAS increased the fecal pellet expulsion and spontaneous contractile activities of the Colonic Muscle strips. Both BDNF and SP in the Colonic mucosa were elevated following WAS. Immunohistochemistry revealed the presence of BDNF and TrkB in the mucosa and myenteric plexus. BDNF and TrkB were both up-regulated in colon devoid of mucosa and submucosa from the stressed rats compared with the control. BDNF pretreatment caused an enhancement of the SP-induced contraction of the circular Muscle (CM) strips. TrkB antibody significantly inhibited the contraction of the Colonic Muscle strips and attenuated the excitatory effects of SP on contractions of the CM strips. Repeated WAS increased the contractile activities of the CM strips induced by SP after BDNF pretreatment, and this effect was reversed by TrkB antibody. The Colonic hypermotility induced by repeated WAS may be associated with the increased expression of endogenous BDNF and TrkB. BDNF may have potential clinical therapeutic use in modulating gut motility.
Fang Li - One of the best experts on this subject based on the ideXlab platform.
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interleukin 1β up regulates rgs4 through the canonical ikk2 iκbα nf κb pathway in rabbit Colonic smooth Muscle
Biochemical Journal, 2008Co-Authors: Wenhui Hu, Sunila Mahavadi, Fang Li, Karnam S. MurthyAbstract:Initial Ca2+-dependent contraction of the intestinal smooth Muscle mediated by Gq-coupled receptors is attenuated by RGS4 (regulator of G-protein signalling 4). Treatment of Colonic Muscle cells with IL-1β (interleukin-1β) inhibits acetylcholine-stimulated initial contraction through increasing the expression of RGS4. NF-κB (nuclear factor κB) signalling is the dominant pathway activated by IL-1β. In the present study we show that RGS4 is a new target gene regulated by IL-1β/NF-κB signalling. Exposure of cultured rabbit Colonic Muscle cells to IL-1β induced a rapid increase in RGS4 mRNA expression, which was abolished by pretreatment with a transcription inhibitor, actinomycin D, implying a transcription-dependent mechanism. Existence of the canonical IKK2 [IκB (inhibitor of NF-κB) kinase 2]/IκBα pathway of NF-κB activation induced by IL-1β in rabbit Colonic Muscle cells was validated with multiple approaches, including the induction of reporter luciferase activity and endogenous NF-κB-target gene expression, NF-κB-DNA binding activity, p65 nuclear translocation, IκBα degradation and the phosphorylation of IKK2 at Ser177/181 and p65 at Ser536. RGS4 up-regulation by IL-1β was blocked by selective inhibitors of IKK2, IκBα or NF-κB activation, by effective siRNA (small interfering RNA) of IKK2, and in cells expressing either the kinase-inactive IKK2 mutant (K44A) or the phosphorylation-deficient IκBα mutant (S32A/S36A). An IKK2-specific inhibitor or effective siRNA prevented IL-1β-induced inhibition of acetylcholine-stimulated PLC-β (phopsholipase C-β) activation. These results suggest that the canonical IKK2/IκBα pathway of NF-κB activation mediates the up-regulation of RGS4 expression in response to IL-1β and contributes to the inhibitory effect of IL-1β on acetylcholine-stimulated PLC-β-dependent initial contraction in rabbit Colonic smooth Muscle.
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Interleukin-1β up-regulates RGS4 through the canonical IKK2/IκBα/NF-κB pathway in rabbit Colonic smooth Muscle
Biochemical Journal, 2008Co-Authors: Wenhui Hu, Sunila Mahavadi, Fang Li, Karnam S. MurthyAbstract:Initial Ca2+-dependent contraction of the intestinal smooth Muscle mediated by Gq-coupled receptors is attenuated by RGS4 (regulator of G-protein signalling 4). Treatment of Colonic Muscle cells with IL-1β (interleukin-1β) inhibits acetylcholine-stimulated initial contraction through increasing the expression of RGS4. NF-κB (nuclear factor κB) signalling is the dominant pathway activated by IL-1β. In the present study we show that RGS4 is a new target gene regulated by IL-1β/NF-κB signalling. Exposure of cultured rabbit Colonic Muscle cells to IL-1β induced a rapid increase in RGS4 mRNA expression, which was abolished by pretreatment with a transcription inhibitor, actinomycin D, implying a transcription-dependent mechanism. Existence of the canonical IKK2 [IκB (inhibitor of NF-κB) kinase 2]/IκBα pathway of NF-κB activation induced by IL-1β in rabbit Colonic Muscle cells was validated with multiple approaches, including the induction of reporter luciferase activity and endogenous NF-κB-target gene expression, NF-κB-DNA binding activity, p65 nuclear translocation, IκBα degradation and the phosphorylation of IKK2 at Ser177/181 and p65 at Ser536. RGS4 up-regulation by IL-1β was blocked by selective inhibitors of IKK2, IκBα or NF-κB activation, by effective siRNA (small interfering RNA) of IKK2, and in cells expressing either the kinase-inactive IKK2 mutant (K44A) or the phosphorylation-deficient IκBα mutant (S32A/S36A). An IKK2-specific inhibitor or effective siRNA prevented IL-1β-induced inhibition of acetylcholine-stimulated PLC-β (phopsholipase C-β) activation. These results suggest that the canonical IKK2/IκBα pathway of NF-κB activation mediates the up-regulation of RGS4 expression in response to IL-1β and contributes to the inhibitory effect of IL-1β on acetylcholine-stimulated PLC-β-dependent initial contraction in rabbit Colonic smooth Muscle.
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Interleukin-1β up-regulates RGS4 through the canonical IKK2/IκBα/NF-κB pathway in rabbit Colonic smooth Muscle
Biochemical Journal, 2008Co-Authors: Wenhui Hu, Sunila Mahavadi, Fang Li, Karnam S. MurthyAbstract:Initial Ca2+-dependent contraction of the intestinal smooth Muscle mediated by Gq-coupled receptors is attenuated by RGS4 (regulator of G-protein signalling 4). Treatment of Colonic Muscle cells with IL-1β (interleukin-1β) inhibits acetylcholine-stimulated initial contraction through increasing the expression of RGS4. NF-κB (nuclear factor κB) signalling is the dominant pathway activated by IL-1β. In the present study we show that RGS4 is a new target gene regulated by IL-1β/NF-κB signalling. Exposure of cultured rabbit Colonic Muscle cells to IL-1β induced a rapid increase in RGS4 mRNA expression, which was abolished by pretreatment with a transcription inhibitor, actinomycin D, implying a transcription-dependent mechanism. Existence of the canonical IKK2 [IκB (inhibitor of NF-κB) kinase 2]/IκBα pathway of NF-κB activation induced by IL-1β in rabbit Colonic Muscle cells was validated with multiple approaches, including the induction of reporter luciferase activity and endogenous NF-κB-target gene expression, NF-κB-DNA binding activity, p65 nuclear translocation, IκBα degradation and the phosphorylation of IKK2 at Ser177/181 and p65 at Ser536. RGS4 up-regulation by IL-1β was blocked by selective inhibitors of IKK2, IκBα or NF-κB activation, by effective siRNA (small interfering RNA) of IKK2, and in cells expressing either the kinase-inactive IKK2 mutant (K44A) or the phosphorylation-deficient IκBα mutant (S32A/S36A). An IKK2-specific inhibitor or effective siRNA prevented IL-1β-induced inhibition of acetylcholine-stimulated PLC-β (phopsholipase C-β) activation. These results suggest that the canonical IKK2/IκBα pathway of NF-κB activation mediates the up-regulation of RGS4 expression in response to IL-1β and contributes to the inhibitory effect of IL-1β on acetylcholine-stimulated PLC-β-dependent initial contraction in rabbit Colonic smooth Muscle.
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upregulation of rgs4 and downregulation of cpi 17 mediate inhibition of Colonic Muscle contraction by interleukin 1β
American Journal of Physiology-cell Physiology, 2007Co-Authors: Wenhui Hu, Sunila Mahavadi, Fang Li, Karnam S. MurthyAbstract:The pro-inflammatory cytokine IL-1β contributes to the reduced contractile responses of gut smooth Muscle observed in both animal colitis models and human inflammatory bowel diseases. However, the ...