The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
Kozo Kaibuchi - One of the best experts on this subject based on the ideXlab platform.
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Smooth Muscle Contraction by small GTPase Rho.
Nagoya journal of medical science, 2020Co-Authors: Yoji Kawano, Takeshi Yoshimura, Kozo KaibuchiAbstract:Abnormal Contraction of vascular Smooth Muscle contributes to a variety of diseases such as hypertension and vasospasm in coronary and cerebral arteries. An increment in a cytoplasmic Ca2+ concentration is the key event in Smooth Muscle Contraction. However, Smooth Muscle Contraction is modified upon the stimulation by agonists as well as in some pathophysiological situations in Ca(2+)-independent mechanism. The molecular mechanism underlying this modulation was not elucidated. Recent studies have shown the important role of small GTPase Rho and its effector, Rho-associated kinase (Rho-kinase)/ROK/ROCK in Ca(2+)-independent regulation of Smooth Muscle Contraction. The Rho/Rho-kinase pathway modulates the phosphorylation level of myosin light chain (MLC) of myosin II, mainly through the inhibition of myosin phosphatase, and contributes to the agonist-induced Ca(2+)-sensitization in Smooth Muscle Contraction. The Rho/Rho-kinase pathway is involved in the pathogenesis of hypertension, vasospasm and arteriosclerosis, and is a potent target of new therapies for these diseases.
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Rho–Rho-kinase pathway in Smooth Muscle Contraction and cytoskeletal reorganization of non-Muscle cells
Trends in Pharmacological Sciences, 2001Co-Authors: Yuko Fukata, Kozo Kaibuchi, Mutsuki AmanoAbstract:Abstract HyperContraction or abnormal Contraction of vascular Smooth Muscle is a major cause of diseases such as hypertension and vasospasm of the coronary and cerebral arteries. A better understanding of the mechanism of regulation of Smooth Muscle Contraction should lead to improved treatments for such diseases. Recent studies have revealed important roles for the small GTPase Rho and its effector, Rho-associated kinase (Rho kinase) in Ca 2+ -independent regulation of Smooth Muscle Contraction. The Rho–Rho-kinase pathway modulates the level of phosphorylation of the myosin light chain of myosin II, mainly through inhibition of myosin phosphatase, and contributes to agonist-induced Ca 2+ -sensitization in Smooth Muscle Contraction. Rho–Rho-kinase mechanisms also participate in a variety of the cellular functions of non-Muscle cells, such as stress-fibre formation, cytokinesis and cell migration. This review summarizes the role of the Rho–Rho-kinase pathway in contractile processes of Smooth Muscle and in non-Muscle cell functions, and the pathophysiological implications of this pathway.
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rho rho kinase pathway in Smooth Muscle Contraction and cytoskeletal reorganization of non Muscle cells
Trends in Pharmacological Sciences, 2001Co-Authors: Yuko Fukata, Kozo Kaibuchi, Mutsuki AmanoAbstract:Abstract HyperContraction or abnormal Contraction of vascular Smooth Muscle is a major cause of diseases such as hypertension and vasospasm of the coronary and cerebral arteries. A better understanding of the mechanism of regulation of Smooth Muscle Contraction should lead to improved treatments for such diseases. Recent studies have revealed important roles for the small GTPase Rho and its effector, Rho-associated kinase (Rho kinase) in Ca 2+ -independent regulation of Smooth Muscle Contraction. The Rho–Rho-kinase pathway modulates the level of phosphorylation of the myosin light chain of myosin II, mainly through inhibition of myosin phosphatase, and contributes to agonist-induced Ca 2+ -sensitization in Smooth Muscle Contraction. Rho–Rho-kinase mechanisms also participate in a variety of the cellular functions of non-Muscle cells, such as stress-fibre formation, cytokinesis and cell migration. This review summarizes the role of the Rho–Rho-kinase pathway in contractile processes of Smooth Muscle and in non-Muscle cell functions, and the pathophysiological implications of this pathway.
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rho associated kinase directly induces Smooth Muscle Contraction through myosin light chain phosphorylation
Journal of Biological Chemistry, 1997Co-Authors: Yasuko Kureishi, Kazushi Kimura, Sei Kobayashi, Hideo Kanaide, Takeshi Nakano, Mutsuki Amano, Kozo KaibuchiAbstract:Abstract Small GTPase Rho plays pivotal roles in the Ca2+ sensitization of Smooth Muscle. However, the GTP-bound active form of Rho failed to exert Ca2+-sensitizing effects in extensively Triton X-100-permeabilized Smooth Muscle preparations, due to the loss of the important diffusible cofactor (Gong, M. C., Iizuka, K., Nixon, G., Browne, J. P., Hall, A., Eccleston, J. F., Sugai, M., Kobayashi, S., Somlyo, A. V., and Somlyo, A. P. (1996) Proc. Natl. Acad. Sci. U. S. A. 93, 1340–1345). Here we demonstrate the contractile effects of Rho-associated kinase (Rho-kinase), recently identified as a putative target of Rho, on the Triton X-100-permeabilized Smooth Muscle of rabbit portal vein. Introduction of the constitutively active form of Rho-kinase into the cytosol of Triton X-100-permeabilized Smooth Muscle provoked a Contraction and a proportional increase in levels of monophosphorylation of myosin light chain in both the presence and the absence of cytosolic Ca2+. These effects of constitutively active Rho-kinase were wortmannin (a potent myosin light chain kinase inhibitor)-insensitive. Immunoblot analysis revealed that the amount of native Rho-kinase was markedly lower in Triton X-100-permeabilized tissue than in intact tissue. Our results demonstrate that Rho-kinase directly modulates Smooth Muscle Contraction through myosin light chain phosphorylation, independently of the Ca2+-calmodulin-dependent myosin light chain kinase pathway.
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involvement of rho p21 in the gtp enhanced calcium ion sensitivity of Smooth Muscle Contraction
Journal of Biological Chemistry, 1992Co-Authors: Kenichi Hirata, Kozo Kaibuchi, Akira Kikuchi, Takuya Sasaki, Shinya Kuroda, Yoshiharu Matsuura, H Seki, K Saida, Yoshimi TakaiAbstract:Abstract In the rabbit mesenteric arterial Smooth Muscle skinned by saponin, Ca2+ induced Contraction in a concentration-dependent manner. Guanosine 5'-(3-O-thio)triphosphate (GTP gamma S), a non-hydrolyzable GTP analogue, lowered the Ca2+ concentrations required for this Contraction and increased the Ca2+ sensitivity of the skinned Smooth Muscle Contraction. GTP gamma S alone did not induce the Contraction in the absence of Ca2+. This GTP gamma S-enhanced Ca2+ sensitivity was completely abolished by an exoenzyme of Staphylococcus aureus, named EDIN, and an exoenzyme of Clostridium botulinum, named C3, both of which are known to ADP-ribosylate the rho p21 family that belongs to the ras p21-like small GTP-binding protein superfamily. The GTP gamma S-bound form of rhoA p21 overcame the inhibitory action of EDIN. smg p21B, another small GTP-binding protein, was inactive. EDIN ADP-ribosylated a protein, which was most likely to be rho p21, in the skinned Smooth Muscle. The GTP gamma S-bound form of rhoA p21, but not the GDP-bound form, substituted for GTP gamma S and enhanced the Ca2+ sensitivity of the skinned Smooth Muscle Contraction. smg p21B was inactive. These results indicate that rhoA p21 is involved in the GTP gamma S-enhanced Ca2+ sensitivity of the Smooth Muscle Contraction.
Mutsuki Amano - One of the best experts on this subject based on the ideXlab platform.
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Rho–Rho-kinase pathway in Smooth Muscle Contraction and cytoskeletal reorganization of non-Muscle cells
Trends in Pharmacological Sciences, 2001Co-Authors: Yuko Fukata, Kozo Kaibuchi, Mutsuki AmanoAbstract:Abstract HyperContraction or abnormal Contraction of vascular Smooth Muscle is a major cause of diseases such as hypertension and vasospasm of the coronary and cerebral arteries. A better understanding of the mechanism of regulation of Smooth Muscle Contraction should lead to improved treatments for such diseases. Recent studies have revealed important roles for the small GTPase Rho and its effector, Rho-associated kinase (Rho kinase) in Ca 2+ -independent regulation of Smooth Muscle Contraction. The Rho–Rho-kinase pathway modulates the level of phosphorylation of the myosin light chain of myosin II, mainly through inhibition of myosin phosphatase, and contributes to agonist-induced Ca 2+ -sensitization in Smooth Muscle Contraction. Rho–Rho-kinase mechanisms also participate in a variety of the cellular functions of non-Muscle cells, such as stress-fibre formation, cytokinesis and cell migration. This review summarizes the role of the Rho–Rho-kinase pathway in contractile processes of Smooth Muscle and in non-Muscle cell functions, and the pathophysiological implications of this pathway.
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rho rho kinase pathway in Smooth Muscle Contraction and cytoskeletal reorganization of non Muscle cells
Trends in Pharmacological Sciences, 2001Co-Authors: Yuko Fukata, Kozo Kaibuchi, Mutsuki AmanoAbstract:Abstract HyperContraction or abnormal Contraction of vascular Smooth Muscle is a major cause of diseases such as hypertension and vasospasm of the coronary and cerebral arteries. A better understanding of the mechanism of regulation of Smooth Muscle Contraction should lead to improved treatments for such diseases. Recent studies have revealed important roles for the small GTPase Rho and its effector, Rho-associated kinase (Rho kinase) in Ca 2+ -independent regulation of Smooth Muscle Contraction. The Rho–Rho-kinase pathway modulates the level of phosphorylation of the myosin light chain of myosin II, mainly through inhibition of myosin phosphatase, and contributes to agonist-induced Ca 2+ -sensitization in Smooth Muscle Contraction. Rho–Rho-kinase mechanisms also participate in a variety of the cellular functions of non-Muscle cells, such as stress-fibre formation, cytokinesis and cell migration. This review summarizes the role of the Rho–Rho-kinase pathway in contractile processes of Smooth Muscle and in non-Muscle cell functions, and the pathophysiological implications of this pathway.
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rho associated kinase directly induces Smooth Muscle Contraction through myosin light chain phosphorylation
Journal of Biological Chemistry, 1997Co-Authors: Yasuko Kureishi, Kazushi Kimura, Sei Kobayashi, Hideo Kanaide, Takeshi Nakano, Mutsuki Amano, Kozo KaibuchiAbstract:Abstract Small GTPase Rho plays pivotal roles in the Ca2+ sensitization of Smooth Muscle. However, the GTP-bound active form of Rho failed to exert Ca2+-sensitizing effects in extensively Triton X-100-permeabilized Smooth Muscle preparations, due to the loss of the important diffusible cofactor (Gong, M. C., Iizuka, K., Nixon, G., Browne, J. P., Hall, A., Eccleston, J. F., Sugai, M., Kobayashi, S., Somlyo, A. V., and Somlyo, A. P. (1996) Proc. Natl. Acad. Sci. U. S. A. 93, 1340–1345). Here we demonstrate the contractile effects of Rho-associated kinase (Rho-kinase), recently identified as a putative target of Rho, on the Triton X-100-permeabilized Smooth Muscle of rabbit portal vein. Introduction of the constitutively active form of Rho-kinase into the cytosol of Triton X-100-permeabilized Smooth Muscle provoked a Contraction and a proportional increase in levels of monophosphorylation of myosin light chain in both the presence and the absence of cytosolic Ca2+. These effects of constitutively active Rho-kinase were wortmannin (a potent myosin light chain kinase inhibitor)-insensitive. Immunoblot analysis revealed that the amount of native Rho-kinase was markedly lower in Triton X-100-permeabilized tissue than in intact tissue. Our results demonstrate that Rho-kinase directly modulates Smooth Muscle Contraction through myosin light chain phosphorylation, independently of the Ca2+-calmodulin-dependent myosin light chain kinase pathway.
Qingfeng Yu - One of the best experts on this subject based on the ideXlab platform.
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a nav2729 sensitive mechanism promotes adrenergic Smooth Muscle Contraction and growth of stromal cells in the human prostate
Journal of Biological Chemistry, 2019Co-Authors: Bingsheng Li, Ruixiao Wang, Qingfeng Yu, Christian Gratzke, Paul Kuppermann, Annika Herlemann, Alexander Tamalunas, Yiming WangAbstract:Voiding symptoms in benign prostatic hyperplasia (BPH) are driven by prostate Smooth Muscle Contraction and prostate growth. Smooth Muscle Contraction in the prostate and other organs critically depends on activation of the small monomeric GTPase RhoA and probably Rac1. A role of another GTPase, ADP-ribosylation factor 6 (ARF6), for Smooth Muscle Contraction has been recently suggested by indirect evidence but remains to be proven for any organ. Here, we report effects of NAV2729, an inhibitor with assumed specificity for ARF6, in human prostate tissues and cultured prostate stromal cells (WPMY-1). NAV2729 (5 μm) inhibited neurogenic and α1-adrenergic Contractions of human prostate tissues. Contractions induced by endothelin-1, by the thromboxane A2 agonist U46619, or by high molar KCl were not inhibited. Correlation analyses suggested up-regulation of prostatic ARF6 expression with increasing degree of BPH, as ARF6 expression increased with the content of prostate-specific antigen (PSA) of prostate tissues. NAV2729 inhibited ARF6 activity but not other GTPases (ARF1, RhoA, Rac1) in prostate tissues and in WPMY-1 cells. Proliferation of WPMY-1 cells was inhibited concentration-dependently by NAV2726, as reflected by decreased viability, 5-ethynyl-2'-deoxyuridine (EdU) assay, colony formation assay, and expression of Ki-67. Silencing of ARF6 expression mimicked effects of NAV2729 on viability and in the EdU assay. Effects of NAV2729 on viability and proliferation were attenuated in cells with silenced ARF6 expression. Our findings suggest that a NAV2729-sensitive mechanism promotes adrenergic Contraction and stromal cell growth in the human prostate, which is probably ARF6-mediated. Similar actions in other organs and urodynamic effects of NAV2729 appear possible.
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MP06-10 INHIBITION OF PROSTATE Smooth Muscle Contraction BY NAV2729 SUGGESTS PROMOTION OF PROSTATE Smooth Muscle Contraction BY ADP RIBOSYLATION FACTOR 6
The Journal of Urology, 2019Co-Authors: Qingfeng Yu, Yiming Wang, Christian Gratzke, Paul Kuppermann, Annika Herlemann, Alexander Tamalunas, Beata Rutz, Anna Ciotkowska, Raphaela Waidelich, Christian G. StiefAbstract:INTRODUCTION AND OBJECTIVES:In benign prostatic hyperplasia, prostate Smooth Muscle Contraction drives urethral obstruction, resulting in lower urinary tract symptoms. Inhibition of prostate contra...
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Inhibition of Prostate Smooth Muscle Contraction by Inhibitors of Polo-Like Kinases
Frontiers in Physiology, 2018Co-Authors: Martin Hennenberg, Yiming Wang, Qingfeng Yu, Paul Kuppermann, Annika Herlemann, Alexander Tamalunas, Beata Rutz, Anna Ciotkowska, Frank Strittmatter, Christian G. StiefAbstract:Background: Prostate Smooth Muscle Contraction plays an important role for pathophysiology and treatment of male lower urinary tract symptoms (LUTS) but is incompletely understood. Because the efficacy of available medication is limited, novel options and improved understanding of prostate Smooth Muscle Contraction are mandatory. Recently, a possible role of polo-like kinase 1 (PLK1) has been suggested for Smooth Muscle Contraction outside the lower urinary tract. Here, we examined effects of PLK inhibitors on Contraction of human prostate tissue. Methods: Prostate tissues were obtained from radical prostatectomy. RT-PCR, Western blot and immunofluorescence were performed to detect PLK expression and phosphorylated PLK. Smooth Muscle Contractions were induced by electric field stimulation (EFS), α1-agonists, endothelin-1, or the thromboxane A2 analogue U46619 in organ bath. Results: RT-PCR, Western blot, and immunofluorescence suggested expression of PLK1 in the human prostate, which may be located and active in Smooth Muscle cells. EFS-induced Contractions of prostate strips were reduced by SBE 13 (1 µM), cyclapolin 9 (3 µM), TAK 960 (100 nM), and Ro 3280 (100 nM). SBE 13 and cyclapolin 9 inhibited Contractions by the α1-agonists methoxamine, phenylephrine, and noradrenaline. In contrast, no effects of SBE 13 or cyclapolin 9 on endothelin-1- or U46619-induced Contractions were observed. Conclusions: Alpha1-adrenergic Smooth Muscle Contraction in the human prostate can be inhibited by PLK inhibitors. PLK-dependent signaling may be a new pathway, which promotes α1-adrenergic Contraction of prostate Smooth Muscle cells. As Contractions by endothelin and U46619 are not susceptible to PLK inhibition, this reflects divergent regulation of adrenergic and non-adrenergic prostate Smooth Muscle Contraction.
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Inhibition of human prostate Smooth Muscle Contraction by the LIM kinase inhibitors, SR7826 and LIMKi3.
British Journal of Pharmacology, 2018Co-Authors: Qingfeng Yu, Yiming Wang, Christian Gratzke, Annika Herlemann, Beata Rutz, Anna Ciotkowska, Frank Strittmatter, Christian Sterr, Xiaolong Wang, Christian G. StiefAbstract:LUTS refer to a group of urological symptoms that are caused by multifactorial aetiology. The prevalence of LUTS increases with age, and will thereby lead to heavy economic burden for the society. In men with benign prostate hyperplasia, increased Smooth Muscle tone in the prostate could result in bladder outlet obstruction and subsequent symptoms of lower urinary tract. Pharmacological treatment aiming to inhibit prostate Smooth Muscle Contraction is considered as the option of first choice. However, the efficacy of current available treatment options is limited, thereby, improved understanding in the mechanisms of prostate Smooth Muscle Contraction and development of novel targets for medical therapy are warranted. Previous studies have reported that LIMK (LIMK1 and LIMK2) phosphorylate cofilin and act as regulators of actin-myosin cytoskeletal dynamics, which result in actin polymerization, filament assemble, and stress fiber formation in Smooth Muscle cells. This may suggest that LIMKs promote Smooth Muscle Contraction, however, not any associated study has been conducted. In this project, we aimed to explore the effects of LIMK inhibitors on prostate Smooth Muscle Contraction. Human prostate tissues were obtained from patients who underwent radical prostatectomy. RT-PCR, western blot and immunofluorescence were performed to detect LIMK in Smooth Muscle cells of prostate tissues. Phosphorylation of cofilin, a LIMK substrate, was detected by a phospho-specific antibody. Effects of LIMK inhibitors on Smooth Muscle Contraction of prostate strips were performed with organ bath. Expression of LIMK in Smooth Muscle cells of prostate tissues was suggested by RT-PCR, Western blot and immunofluorescence, while higher expression level of LIMK was detected in prostate tissues than that in WPMY-1 cells. Two LIMK inhibitors, SR7826 (1 µM) and LIMKi3 (1 µM), showed significant effects on inhibiting Contractions of prostate strips, which were induced by the α1-adrenoceptor agonists, noradrenaline, phenylephrine and methoxamine, by the thromboxane A2 analogue, U46619, and by EFS. Reduced phosphorylation of cofilin in prostate tissues treated with inhibitors was observed, which confirmed LIMK inhibition by SR7826 and LIMKi3. In WPMY-1 cells, a line of cultured cells from the prostate stroma, SR7826 and LIMKi3 were observed to cause breakdown of actin filaments and reduced viability in a concentration-dependent manner. Together, this is the first study to explore the effects of small molecule LIMK inhibitors on regulating prostate Smooth Muscle Contraction. The present study suggested that LIMKs promote prostate Smooth Muscle Contraction by phosphorylating cofilin and subsequent causing actin organization, which could be inhibited by small molecule LIMK inhibitors, SR7826 and LIMKi3. Therefore, this project provides a possible novel therapy target for LUTS, although in vivo studies using animal models would be still warranted before clinical application.
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Inhibition of Smooth Muscle Contraction and ARF6 activity by the inhibitor for cytohesin GEFs, secinH3, in the human prostate
American Journal of Physiology-renal Physiology, 2017Co-Authors: Annika Herlemann, Yiming Wang, Qingfeng Yu, Alexander Tamalunas, Beata Rutz, Anna Ciotkowska, Raphaela Waidelich, Patrick Keller, Melanie Schott, Frank StrittmatterAbstract:Prostate Smooth Muscle Contraction is critical for etiology and treatment of male lower urinary tract symptoms (LUTS) and is promoted by small monomeric GTPases (RhoA and Rac). GTPases may be activ...
Yuko Fukata - One of the best experts on this subject based on the ideXlab platform.
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Rho–Rho-kinase pathway in Smooth Muscle Contraction and cytoskeletal reorganization of non-Muscle cells
Trends in Pharmacological Sciences, 2001Co-Authors: Yuko Fukata, Kozo Kaibuchi, Mutsuki AmanoAbstract:Abstract HyperContraction or abnormal Contraction of vascular Smooth Muscle is a major cause of diseases such as hypertension and vasospasm of the coronary and cerebral arteries. A better understanding of the mechanism of regulation of Smooth Muscle Contraction should lead to improved treatments for such diseases. Recent studies have revealed important roles for the small GTPase Rho and its effector, Rho-associated kinase (Rho kinase) in Ca 2+ -independent regulation of Smooth Muscle Contraction. The Rho–Rho-kinase pathway modulates the level of phosphorylation of the myosin light chain of myosin II, mainly through inhibition of myosin phosphatase, and contributes to agonist-induced Ca 2+ -sensitization in Smooth Muscle Contraction. Rho–Rho-kinase mechanisms also participate in a variety of the cellular functions of non-Muscle cells, such as stress-fibre formation, cytokinesis and cell migration. This review summarizes the role of the Rho–Rho-kinase pathway in contractile processes of Smooth Muscle and in non-Muscle cell functions, and the pathophysiological implications of this pathway.
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rho rho kinase pathway in Smooth Muscle Contraction and cytoskeletal reorganization of non Muscle cells
Trends in Pharmacological Sciences, 2001Co-Authors: Yuko Fukata, Kozo Kaibuchi, Mutsuki AmanoAbstract:Abstract HyperContraction or abnormal Contraction of vascular Smooth Muscle is a major cause of diseases such as hypertension and vasospasm of the coronary and cerebral arteries. A better understanding of the mechanism of regulation of Smooth Muscle Contraction should lead to improved treatments for such diseases. Recent studies have revealed important roles for the small GTPase Rho and its effector, Rho-associated kinase (Rho kinase) in Ca 2+ -independent regulation of Smooth Muscle Contraction. The Rho–Rho-kinase pathway modulates the level of phosphorylation of the myosin light chain of myosin II, mainly through inhibition of myosin phosphatase, and contributes to agonist-induced Ca 2+ -sensitization in Smooth Muscle Contraction. Rho–Rho-kinase mechanisms also participate in a variety of the cellular functions of non-Muscle cells, such as stress-fibre formation, cytokinesis and cell migration. This review summarizes the role of the Rho–Rho-kinase pathway in contractile processes of Smooth Muscle and in non-Muscle cell functions, and the pathophysiological implications of this pathway.
Yiming Wang - One of the best experts on this subject based on the ideXlab platform.
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Regulation of Smooth Muscle Contraction by monomeric non-RhoA GTPases.
British Journal of Pharmacology, 2020Co-Authors: Bingsheng Li, Ruixiao Wang, Yiming Wang, Christian G. Stief, Martin HennenbergAbstract:Smooth Muscle Contraction in the cardiovascular system, airways, prostate, and lower urinary tract is involved in pathophysiology and medical treatment of widespread diseases, including cardiovascular diseases, obstructive lung diseases, and lower urinary tract symptoms, which are associated with high prevalence and mortality. In line with the prominent clinical role of Smooth Muscle tone, molecular mechanisms of Smooth Muscle Contraction were subject of extensive research. At intracellular level, Contraction is promoted by three widely accepted signaling pathways, shared by all Smooth Muscle-rich organs, and including the monomeric GTPase RhoA. Emerging evidence suggests that monomeric GTPases other than RhoA may be involved in signal transduction to Smooth Muscle Contraction as well, including Rac GTPases, Cdc42, adenosine ribosylation factor 6, Ras, Rap1b, and Rab GTPases. Here, we review emerging functions of non-RhoA GTPases for Smooth Muscle Contraction, which becomes increasingly obvious, and constitutes an emerging and innovative research field of high clinical relevance.
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a nav2729 sensitive mechanism promotes adrenergic Smooth Muscle Contraction and growth of stromal cells in the human prostate
Journal of Biological Chemistry, 2019Co-Authors: Bingsheng Li, Ruixiao Wang, Qingfeng Yu, Christian Gratzke, Paul Kuppermann, Annika Herlemann, Alexander Tamalunas, Yiming WangAbstract:Voiding symptoms in benign prostatic hyperplasia (BPH) are driven by prostate Smooth Muscle Contraction and prostate growth. Smooth Muscle Contraction in the prostate and other organs critically depends on activation of the small monomeric GTPase RhoA and probably Rac1. A role of another GTPase, ADP-ribosylation factor 6 (ARF6), for Smooth Muscle Contraction has been recently suggested by indirect evidence but remains to be proven for any organ. Here, we report effects of NAV2729, an inhibitor with assumed specificity for ARF6, in human prostate tissues and cultured prostate stromal cells (WPMY-1). NAV2729 (5 μm) inhibited neurogenic and α1-adrenergic Contractions of human prostate tissues. Contractions induced by endothelin-1, by the thromboxane A2 agonist U46619, or by high molar KCl were not inhibited. Correlation analyses suggested up-regulation of prostatic ARF6 expression with increasing degree of BPH, as ARF6 expression increased with the content of prostate-specific antigen (PSA) of prostate tissues. NAV2729 inhibited ARF6 activity but not other GTPases (ARF1, RhoA, Rac1) in prostate tissues and in WPMY-1 cells. Proliferation of WPMY-1 cells was inhibited concentration-dependently by NAV2726, as reflected by decreased viability, 5-ethynyl-2'-deoxyuridine (EdU) assay, colony formation assay, and expression of Ki-67. Silencing of ARF6 expression mimicked effects of NAV2729 on viability and in the EdU assay. Effects of NAV2729 on viability and proliferation were attenuated in cells with silenced ARF6 expression. Our findings suggest that a NAV2729-sensitive mechanism promotes adrenergic Contraction and stromal cell growth in the human prostate, which is probably ARF6-mediated. Similar actions in other organs and urodynamic effects of NAV2729 appear possible.
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MP06-10 INHIBITION OF PROSTATE Smooth Muscle Contraction BY NAV2729 SUGGESTS PROMOTION OF PROSTATE Smooth Muscle Contraction BY ADP RIBOSYLATION FACTOR 6
The Journal of Urology, 2019Co-Authors: Qingfeng Yu, Yiming Wang, Christian Gratzke, Paul Kuppermann, Annika Herlemann, Alexander Tamalunas, Beata Rutz, Anna Ciotkowska, Raphaela Waidelich, Christian G. StiefAbstract:INTRODUCTION AND OBJECTIVES:In benign prostatic hyperplasia, prostate Smooth Muscle Contraction drives urethral obstruction, resulting in lower urinary tract symptoms. Inhibition of prostate contra...
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Inhibition of Prostate Smooth Muscle Contraction by Inhibitors of Polo-Like Kinases
Frontiers in Physiology, 2018Co-Authors: Martin Hennenberg, Yiming Wang, Qingfeng Yu, Paul Kuppermann, Annika Herlemann, Alexander Tamalunas, Beata Rutz, Anna Ciotkowska, Frank Strittmatter, Christian G. StiefAbstract:Background: Prostate Smooth Muscle Contraction plays an important role for pathophysiology and treatment of male lower urinary tract symptoms (LUTS) but is incompletely understood. Because the efficacy of available medication is limited, novel options and improved understanding of prostate Smooth Muscle Contraction are mandatory. Recently, a possible role of polo-like kinase 1 (PLK1) has been suggested for Smooth Muscle Contraction outside the lower urinary tract. Here, we examined effects of PLK inhibitors on Contraction of human prostate tissue. Methods: Prostate tissues were obtained from radical prostatectomy. RT-PCR, Western blot and immunofluorescence were performed to detect PLK expression and phosphorylated PLK. Smooth Muscle Contractions were induced by electric field stimulation (EFS), α1-agonists, endothelin-1, or the thromboxane A2 analogue U46619 in organ bath. Results: RT-PCR, Western blot, and immunofluorescence suggested expression of PLK1 in the human prostate, which may be located and active in Smooth Muscle cells. EFS-induced Contractions of prostate strips were reduced by SBE 13 (1 µM), cyclapolin 9 (3 µM), TAK 960 (100 nM), and Ro 3280 (100 nM). SBE 13 and cyclapolin 9 inhibited Contractions by the α1-agonists methoxamine, phenylephrine, and noradrenaline. In contrast, no effects of SBE 13 or cyclapolin 9 on endothelin-1- or U46619-induced Contractions were observed. Conclusions: Alpha1-adrenergic Smooth Muscle Contraction in the human prostate can be inhibited by PLK inhibitors. PLK-dependent signaling may be a new pathway, which promotes α1-adrenergic Contraction of prostate Smooth Muscle cells. As Contractions by endothelin and U46619 are not susceptible to PLK inhibition, this reflects divergent regulation of adrenergic and non-adrenergic prostate Smooth Muscle Contraction.
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Inhibition of human prostate Smooth Muscle Contraction by the LIM kinase inhibitors, SR7826 and LIMKi3.
British Journal of Pharmacology, 2018Co-Authors: Qingfeng Yu, Yiming Wang, Christian Gratzke, Annika Herlemann, Beata Rutz, Anna Ciotkowska, Frank Strittmatter, Christian Sterr, Xiaolong Wang, Christian G. StiefAbstract:LUTS refer to a group of urological symptoms that are caused by multifactorial aetiology. The prevalence of LUTS increases with age, and will thereby lead to heavy economic burden for the society. In men with benign prostate hyperplasia, increased Smooth Muscle tone in the prostate could result in bladder outlet obstruction and subsequent symptoms of lower urinary tract. Pharmacological treatment aiming to inhibit prostate Smooth Muscle Contraction is considered as the option of first choice. However, the efficacy of current available treatment options is limited, thereby, improved understanding in the mechanisms of prostate Smooth Muscle Contraction and development of novel targets for medical therapy are warranted. Previous studies have reported that LIMK (LIMK1 and LIMK2) phosphorylate cofilin and act as regulators of actin-myosin cytoskeletal dynamics, which result in actin polymerization, filament assemble, and stress fiber formation in Smooth Muscle cells. This may suggest that LIMKs promote Smooth Muscle Contraction, however, not any associated study has been conducted. In this project, we aimed to explore the effects of LIMK inhibitors on prostate Smooth Muscle Contraction. Human prostate tissues were obtained from patients who underwent radical prostatectomy. RT-PCR, western blot and immunofluorescence were performed to detect LIMK in Smooth Muscle cells of prostate tissues. Phosphorylation of cofilin, a LIMK substrate, was detected by a phospho-specific antibody. Effects of LIMK inhibitors on Smooth Muscle Contraction of prostate strips were performed with organ bath. Expression of LIMK in Smooth Muscle cells of prostate tissues was suggested by RT-PCR, Western blot and immunofluorescence, while higher expression level of LIMK was detected in prostate tissues than that in WPMY-1 cells. Two LIMK inhibitors, SR7826 (1 µM) and LIMKi3 (1 µM), showed significant effects on inhibiting Contractions of prostate strips, which were induced by the α1-adrenoceptor agonists, noradrenaline, phenylephrine and methoxamine, by the thromboxane A2 analogue, U46619, and by EFS. Reduced phosphorylation of cofilin in prostate tissues treated with inhibitors was observed, which confirmed LIMK inhibition by SR7826 and LIMKi3. In WPMY-1 cells, a line of cultured cells from the prostate stroma, SR7826 and LIMKi3 were observed to cause breakdown of actin filaments and reduced viability in a concentration-dependent manner. Together, this is the first study to explore the effects of small molecule LIMK inhibitors on regulating prostate Smooth Muscle Contraction. The present study suggested that LIMKs promote prostate Smooth Muscle Contraction by phosphorylating cofilin and subsequent causing actin organization, which could be inhibited by small molecule LIMK inhibitors, SR7826 and LIMKi3. Therefore, this project provides a possible novel therapy target for LUTS, although in vivo studies using animal models would be still warranted before clinical application.