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Liu S, Zhao Y, Li S, Li Y, Liu L, Sheng J, Tian Y, Gao X. Network pharmacology combined with an animal model to reveal the material basis and mechanism of Amomum villosum in alleviating constipation in mice. Gene 2024; 897:148064. [PMID: 38065427 DOI: 10.1016/j.gene.2023.148064] [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] [Received: 10/13/2023] [Revised: 11/21/2023] [Accepted: 12/04/2023] [Indexed: 01/17/2024]
Abstract
Constipation is a prevalent gastrointestinal disorder, with its prevalence showing an annual upward trend. There are many factors involved in the occurrence of constipation, such as abnormal smooth muscle contraction and disorders of gastrointestinal hormone secretion. Amomum villosum (A. villosum) has been proven to be effective in improving digestive system diseases, but there is no report on improving constipation. Therefore, we used network pharmacology prediction combined with animal experiments to explore the key active components of A. villosum and their pharmacological mechanisms. The results of network pharmacological prediction showed that β-sitosterol was the key laxative compound of A. villosum, which may play a laxative role by activating the adrenoceptor alpha 1 A-myosin light chain (ADRA1A-MLC) pathway. Further animal experiments showed that β-sitosterol could significantly shorten the time to first black stool; increase faecal weight, faecal number, and faecal water content; and promote gastrointestinal motility. β-sitosterol may promote intestinal motility by upregulating the expression of ADRA1A and myosin light chain 9 (Myl9) mRNA and protein in the colon, thereby activating the ADRA1A-MLC signalling pathway. In addition, it is possible to improve constipation symptoms by regulating serum neurotransmitters and gastrointestinal motility-related factors, such as the serum content of 5-hydroxytryptamine (5-HT) and acetylcholinesterase (AchE) and the mRNA expression of 5-hydroxytryptamine receptor 4 (5-HT4), stem cell factor (SCF), stem cell factor receptor (c-Kit) and smooth muscle myosin light chain kinase (smMLCK) in the colon. These results lay a foundation for the application of A. villosum and β-sitosterol in constipation.
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Affiliation(s)
- Shuangfeng Liu
- Yunnan Key Laboratory of Precision Nutrition and Personalized Food Manufacturing, Yunnan Agricultural University, Kunming 650201, China; College of Food Science and Technology, Yunnan Agricultural University, Kunming 650201, China; Engineering Research Center of Development and Utilization of Food and Drug Homologous Resources, Ministry of Education, Yunnan Agricultural University, Kunming 650201, China
| | - Yan Zhao
- Division of Science and Technology, Yunnan Agricultural University, Kunming 650201, China
| | - Sijin Li
- College of Tea (Pu'er), West Yunnan University of Applied Sciences, Puer 665099, China
| | - Yanan Li
- College of Food Science and Technology, Yunnan Agricultural University, Kunming 650201, China
| | - Li Liu
- College of Food Science and Technology, Yunnan Agricultural University, Kunming 650201, China
| | - Jun Sheng
- Engineering Research Center of Development and Utilization of Food and Drug Homologous Resources, Ministry of Education, Yunnan Agricultural University, Kunming 650201, China
| | - Yang Tian
- Yunnan Key Laboratory of Precision Nutrition and Personalized Food Manufacturing, Yunnan Agricultural University, Kunming 650201, China; Engineering Research Center of Development and Utilization of Food and Drug Homologous Resources, Ministry of Education, Yunnan Agricultural University, Kunming 650201, China.
| | - Xiaoyu Gao
- Yunnan Key Laboratory of Precision Nutrition and Personalized Food Manufacturing, Yunnan Agricultural University, Kunming 650201, China; College of Food Science and Technology, Yunnan Agricultural University, Kunming 650201, China; Engineering Research Center of Development and Utilization of Food and Drug Homologous Resources, Ministry of Education, Yunnan Agricultural University, Kunming 650201, China.
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Kalra J, Artamonov M, Wang H, Franke A, Markowska Z, Jin L, Derewenda ZS, Ayon RJ, Somlyo A. p90RSK2, a new MLCK mediates contractility in myosin light chain kinase null smooth muscle. Front Physiol 2023; 14:1228488. [PMID: 37781225 PMCID: PMC10533999 DOI: 10.3389/fphys.2023.1228488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 08/24/2023] [Indexed: 10/03/2023] Open
Abstract
Introduction: Phosphorylation of smooth muscle (SM) myosin regulatory light chain (RLC20) is a critical switch leading to SM contraction. The canonical view held that only the short isoform of myosin light chain kinase (MLCK1) catalyzed this reaction. It is now accepted that auxiliary kinases may contribute to vascular SM tone and contractility. We have previously reported that p90 ribosomal S6 kinase (RSK2) functions as such a kinase, in parallel with MLCK1, contributing ∼25% of the maximal myogenic force in resistance arteries. Thus, RSK2 may be instrumental in the regulation of basal vascular tone and blood pressure. Here, we take advantage of a MLCK1 null mouse (mylk1 -/-) to further test our hypothesis that RSK2 can function as an MLCK, playing a significant physiological role in SM contractility. Methods: Using fetal (E14.5-18.5) SM tissues, as embryos die at birth, we investigated the necessity of MLCK for contractility and fetal development and determined the ability of RSK2 kinase to compensate for the lack of MLCK and characterized its signaling pathway in SM. Results and Discussion: Agonists induced contraction and RLC20 phosphorylation in mylk1 -/- SM was attenuated by RSK2 inhibition. The pCa-tension relationships in permeabilized strips of bladder showed no difference in Ca2+ sensitivity in WT vs mylk1 -/- muscles, although the magnitude of force responses was considerably smaller in the absence of MLCK. The magnitude of contractile responses was similar upon addition of GTPγS to activate the RhoA/ROCK pathway or calyculinA to inhibit the myosin phosphatase. The Ca2+-dependent tyrosine kinase, Pyk2, contributed to RSK2-mediated contractility and RLC20 phosphorylation. Proximity-ligation and immunoprecipitation assays demonstrated an association of RSK2, PDK1 and ERK1/2 with MLCK and actin. RSK2, PDK1, ERK1/2 and MLCK formed a signaling complex on the actin filament, positioning them for interaction with adjacent myosin heads. The Ca2+-dependent component reflected the agonist mediated increases in Ca2+, which activated the Pyk2/PDK1/RSK2 signaling cascade. The Ca2+-independent component was through activation of Erk1/2/PDK1/RSK2 leading to direct phosphorylation of RLC20, to increase contraction. Overall, RSK2 signaling constitutes a new third signaling pathway, in addition to the established Ca2+/CaM/MLCK and RhoA/ROCK pathways to regulate SM contractility.
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Affiliation(s)
- Jaspreet Kalra
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, United States
| | - Mykhaylo Artamonov
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, United States
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Hua Wang
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, United States
- Sentara Martha Jefferson Hospital, Charlottesville, VA, United States
| | - Aaron Franke
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, United States
- Brain Surgery Worldwide, Atlanta, GA, United States
| | - Zaneta Markowska
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, United States
| | - Li Jin
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, United States
- Department of Orthopedics, University of Virginia, Charlottesville, VA, United States
| | - Zygmunt S. Derewenda
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, United States
| | - Ramon J. Ayon
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, United States
| | - Avril Somlyo
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, United States
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Kalra J, Artamonov M, Wang H, Franke A, Markowska Z, Jin L, Derewenda ZS, Ayon R, Somlyo A. p90RSK2, a new MLCK, rescues contractility in myosin light chain kinase null smooth muscle. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.22.541840. [PMID: 37292593 PMCID: PMC10245941 DOI: 10.1101/2023.05.22.541840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Background Phosphorylation of smooth muscle (SM) myosin regulatory light chain (RLC 20 ) is a critical switch leading to contraction or cell migration. The canonical view held that the only kinase catalyzing this reaction is the short isoform of myosin light chain kinase (MLCK1). Auxiliary kinases may be involved and play a vital role in blood pressure homeostasis. We have previously reported that p90 ribosomal S6 kinase (RSK2) functions as such a kinase, in parallel with the classical MLCK1, contributing ∼25% of the maximal myogenic force in resistance arteries and regulating blood pressure. Here, we take advantage of a MLCK1 null mouse to further test our hypothesis that RSK2 can function as an MLCK, playing a significant physiological role in SM contractility. Methods Fetal (E14.5-18.5) SM tissues were used as embryos die at birth. We investigated the necessity of MLCK for contractility, cell migration and fetal development and determined the ability of RSK2 kinase to compensate for the lack of MLCK and characterized it's signaling pathway in SM. Results Agonists induced contraction and RLC 20 phosphorylation in mylk1 -/- SM, that was inhibited by RSK2 inhibitors. Embryos developed and cells migrated in the absence of MLCK. The pCa-tension relationships in WT vs mylk1 -/- muscles demonstrated a Ca 2+ -dependency due to the Ca 2+ -dependent tyrosine kinase Pyk2, known to activate PDK1 that phosphorylates and fully activates RSK2. The magnitude of contractile responses was similar upon addition of GTPγS to activate the RhoA/ROCK pathway. The Ca 2+ -independent component was through activation of Erk1/2/PDK1/RSK2 leading to direct phosphorylation of RLC 20 , to increase contraction. RSK2, PDK1, Erk1/2 and MLCK formed a signaling complex on the actin filament, optimally positioning them for interaction with adjacent myosin heads. Conclusions RSK2 signaling constitutes a new third signaling pathway, in addition to the established Ca 2+ /CAM/MLCK and RhoA/ROCK pathways to regulate SM contractility and cell migration.
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Sorensen DW, Injeti ER, Mejia-Aguilar L, Williams JM, Pearce WJ. Postnatal development alters functional compartmentalization of myosin light chain kinase in ovine carotid arteries. Am J Physiol Regul Integr Comp Physiol 2021; 321:R441-R453. [PMID: 34318702 PMCID: PMC8530762 DOI: 10.1152/ajpregu.00293.2020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The rate-limiting enzyme for vascular contraction, myosin light chain kinase (MLCK), phosphorylates regulatory myosin light chain (MLC20) at rates that appear faster despite lower MLCK abundance in fetal compared with adult arteries. This study explores the hypothesis that greater apparent tissue activity of MLCK in fetal arteries is due to age-dependent differences in intracellular distribution of MLCK in relation to MLC20. Under optimal conditions, common carotid artery homogenates from nonpregnant adult female sheep and near-term fetuses exhibited similar values of Vmax and Km for MLCK. A custom-designed, computer-controlled apparatus enabled electrical stimulation and high-speed freezing of arterial segments at exactly 0, 1, 2, and 3 s, calculation of in situ rates of MLC20 phosphorylation, and measurement of time-dependent colocalization between MLCK and MLC20. The in situ rate of MLC20 phosphorylation divided by total MLCK abundance averaged to values 147% greater in fetal (1.06 ± 0.28) than adult (0.43 ± 0.08) arteries, which corresponded, respectively, to 43 ± 10% and 31 ± 3% of the Vmax values measured in homogenates. Confocal colocalization analysis revealed in fetal and adult arteries that 33 ± 6% and 20 ± 5% of total MLCK colocalized with pMLC20, and that MLCK activation was greater in periluminal than periadventitial regions over the time course of electrical stimulation in both age groups. Together, these results demonstrate that the catalytic activity of MLCK is similar in fetal and adult arteries, but that the fraction of total MLCK in the functional compartment involved in contraction is significantly greater in fetal than adult arteries.
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Affiliation(s)
- Dane W Sorensen
- Division of Physiology, Center for Perinatal Biology, Loma Linda University School of Medicine, Loma Linda, California
| | - Elisha R Injeti
- Department of Pharmaceutical Sciences, Cedarville University School of Pharmacy, Cedarville, Ohio
| | - Luisa Mejia-Aguilar
- Division of Physiology, Center for Perinatal Biology, Loma Linda University School of Medicine, Loma Linda, California
| | - James M Williams
- Division of Physiology, Center for Perinatal Biology, Loma Linda University School of Medicine, Loma Linda, California
| | - William J Pearce
- Division of Physiology, Center for Perinatal Biology, Loma Linda University School of Medicine, Loma Linda, California
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Garrido-Casado M, Asensio-Juárez G, Vicente-Manzanares M. Nonmuscle Myosin II Regulation Directs Its Multiple Roles in Cell Migration and Division. Annu Rev Cell Dev Biol 2021; 37:285-310. [PMID: 34314591 DOI: 10.1146/annurev-cellbio-042721-105528] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Nonmuscle myosin II (NMII) is a multimeric protein complex that generates most mechanical force in eukaryotic cells. NMII function is controlled at three main levels. The first level includes events that trigger conformational changes that extend the complex to enable its assembly into filaments. The second level controls the ATPase activity of the complex and its binding to microfilaments in extended NMII filaments. The third level includes events that modulate the stability and contractility of the filaments. They all work in concert to finely control force generation inside cells. NMII is a common endpoint of mechanochemical signaling pathways that control cellular responses to physical and chemical extracellular cues. Specific phosphorylations modulate NMII activation in a context-dependent manner. A few kinases control these phosphorylations in a spatially, temporally, and lineage-restricted fashion, enabling functional adaptability to the cellular microenvironment. Here, we review mechanisms that control NMII activity in the context of cell migration and division. Expected final online publication date for the Annual Review of Cell and Developmental Biology, Volume 37 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Marina Garrido-Casado
- Molecular Mechanisms Program, Centro de Investigación del Cáncer and Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas, University of Salamanca, 37007 Salamanca, Spain;
| | - Gloria Asensio-Juárez
- Molecular Mechanisms Program, Centro de Investigación del Cáncer and Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas, University of Salamanca, 37007 Salamanca, Spain;
| | - Miguel Vicente-Manzanares
- Molecular Mechanisms Program, Centro de Investigación del Cáncer and Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas, University of Salamanca, 37007 Salamanca, Spain;
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Khapchaev AY, Watterson DM, Shirinsky VP. Phosphorylation-dependent subcellular redistribution of small myosin light chain kinase. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2021; 1868:119104. [PMID: 34302892 DOI: 10.1016/j.bbamcr.2021.119104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 07/16/2021] [Accepted: 07/19/2021] [Indexed: 11/18/2022]
Abstract
BACKGROUND Myosin light chain kinase (MLCK) is a Ca2+-calmodulin-dependent enzyme dedicated to phosphorylate and activate myosin II to provide force for various motile processes. In smooth muscle cells and many other cells, small MLCK (S-MLCK) is a major isoform. S-MLCK is an actomyosin-binding protein firmly attached to contractile machinery in smooth muscle cells. Still, it can leave this location and contribute to other cellular processes. However, molecular mechanisms for switching the S-MLCK subcellular localization have not been described. METHODS Site-directed mutagenesis and in vitro protein phosphorylation were used to study functional roles of discrete in-vivo phosphorylated residues within the S-MLCK actin-binding domain. In vitro co-sedimentation analysis was applied to study the interaction of recombinant S-MLCK actin-binding fragment with filamentous actin. Subcellular distribution of phosphomimicking S-MLCK mutants was studied by fluorescent microscopy and differential cell extraction. RESULTS Phosphorylation of S-MLCK actin-binding domain at Ser25 and/or Thr56 by proline-directed protein kinases or phosphomimicking these posttranslational modifications alters S-MLCK binding to actin filaments both in vitro and in cells, and induces S-MLCK subcellular translocation with no effect on the enzyme catalytic properties. CONCLUSIONS Phosphorylation of the amino terminal actin-binding domain of S-MLCK renders differential subcellular targeting of the enzyme and may, thereby, contribute to a variety of context-dependent responses of S-MLCK to cellular and tissue stimuli. GENERAL SIGNIFICANCE S-MLCK physiological function can potentially be modulated via phosphorylation of its actin recognition domain, a regulation distinct from the catalytic and calmodulin regulatory domains.
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Affiliation(s)
- Asker Y Khapchaev
- National Medical Research Center for Cardiology, 3rd Cherepkovskaya St., 15a, Moscow 121552, Russian Federation.
| | | | - Vladimir P Shirinsky
- National Medical Research Center for Cardiology, 3rd Cherepkovskaya St., 15a, Moscow 121552, Russian Federation
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Diagnosis and prevention of the vasodepressor type of neurally mediated syncope in Japanese patients. PLoS One 2021; 16:e0251450. [PMID: 34170907 PMCID: PMC8232444 DOI: 10.1371/journal.pone.0251450] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 04/27/2021] [Indexed: 01/04/2023] Open
Abstract
We investigated circulatory dynamics in patients with vasodepressor type neurally mediated syncope (VT-NMS) by performing high-resolution Holter electrocardiography and a correlation analysis of changes in adenylate cyclase activity, blood pressure, and pulse during the head-up tilt test. Holter electrocardiography was performed for 30 patients. Adenylate cyclase activity was evaluated in lymphocytes from blood samples taken at rest and during the head-up tilt test. There was no change in autonomic nerve fluctuation during electrocardiography in VT-NMS patients, but our results showed a significant difference in blood pressure and adenylate cyclase activity between VT-NMS patients and healthy volunteers; the systolic blood pressure of VT-NMS patients decreased after 5 min, while at 10 min, the adenylate cyclase activity was the highest (0.53%) and the systolic blood pressure was the lowest (111.8 mm Hg). Pulse rates increased after 10 min. VT-NMS patients showed higher blood pressure, pulse rate, and adenylate cyclase activity during the tilt test than did healthy volunteers. In patients with syncope, standing for longer than 10 minutes may increase the risk of VT-NMS. From our results, we consider it likely that high systolic blood pressure and adenylate cyclase activity at rest cause fainting in VT-NMS patients. Our findings may be helpful for identifying individuals with a high risk of developing NMS in the healthy population.
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Sorensen DW, Carreon D, Williams JM, Pearce WJ. Hypoxic modulation of fetal vascular MLCK abundance, localization, and function. Am J Physiol Regul Integr Comp Physiol 2021; 320:R1-R18. [PMID: 33112654 PMCID: PMC7847055 DOI: 10.1152/ajpregu.00212.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 10/01/2020] [Accepted: 10/13/2020] [Indexed: 12/26/2022]
Abstract
Changes in vascular contractility are among the most important physiological effects of acute and chronic fetal hypoxia. Given the essential role of myosin light-chain kinase (MLCK) in smooth muscle contractility and its heterogeneous distribution, this study explores the hypothesis that subcellular changes in MLCK distribution contribute to hypoxic modulation of fetal carotid artery contractility. Relative to common carotid arteries from normoxic term fetal lambs (FN), carotids from fetal lambs gestated at high altitude (3,802 m) (FH) exhibited depressed contractility without changes in MLCK mRNA or protein abundance. Patterns of confocal colocalization of MLCK with α-actin and 20-kDa regulatory myosin light chain (MLC20) enabled calculation of subcellular MLCK fractions: 1) colocalized with the contractile apparatus, 2) colocalized with α-actin distant from the contractile apparatus, and 3) not colocalized with α-actin. Chronic hypoxia did not affect MLCK abundance in the contractile fraction, despite a concurrent decrease in contractility. Organ culture for 72 h under 1% O2 decreased total MLCK abundance in FN and FH carotid arteries, but decreased the contractile MLCK abundance only in FH carotid arteries. Correspondingly, culture under 1% O2 depressed contractility more in FH than FN carotid arteries. In addition, hypoxia appeared to attenuate ubiquitin-independent proteasomal degradation of MLCK, as reported for other proteins. In aggregate, these results demonstrate that the combination of chronic hypoxia followed by hypoxic culture can induce MLCK translocation among at least three subcellular fractions with possible influences on contractility, indicating that changes in MLCK distribution are a significant component of fetal vascular responses to hypoxia.
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Affiliation(s)
- Dane W Sorensen
- Divisions of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, California
| | - Desirelys Carreon
- Divisions of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, California
| | - James M Williams
- Divisions of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, California
| | - William J Pearce
- Divisions of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, California
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Komiyama T, Nagata E, Hashida T, Sakama S, Ayabe K, Kamiguchi H, Sasaki A, Yoshioka K, Kobayashi H. Neurally mediated syncope diagnosis based on adenylate cyclase activity in Japanese patients. PLoS One 2019; 14:e0214733. [PMID: 30998713 PMCID: PMC6472876 DOI: 10.1371/journal.pone.0214733] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 03/19/2019] [Indexed: 12/11/2022] Open
Abstract
The study aims to clarify the mechanism in patients with neurally mediated syncope (NMS), focusing on the adenylate cyclase (AC) activity level in lymphocytes. This study included 40 subjects: 22 healthy volunteers and 18 NMS patients. We investigated the changes in AC activity that occur during of syncope at rest and during the head-up tilt (HUT) test. We obtained 8 mL of blood at rest time and four times during the HUT test. Then, we measured the AC activity and the test reagent was added to the lymphocytes (10,000) and reacted for 30 min at room temperature. We were able to determine the standard value of AC activity when adrenaline (AD) and isoproterenol (IP) were added to lymphocytes. The results of our study showed one of the causes of NMS has a difference in AC activity level and classification of the patients into two different types of NMS was possible: either the vasodepressor type (VT) or mixed type (MT). At rest time, VT patients showed significantly higher AC activity (AD; 100 μM: p = 0.005, IP; 50 μM: p = 0.02) and MT patients showed significantly lower AC activity (AD; 10 μM: p = 0.02, IP; 50 μM: p = 0.004) than the average AC activity in healthy volunteers. Moreover, VT patients had significantly higher AC activity than healthy volunteers at the four points of the HUT test. MT patients had significantly lower AC activity (AD: p = 0.04 and IP: p = 0.04) than healthy volunteers at the rest time of HUT. Our study showed a significant difference in AC activities between NMS patients and healthy volunteers at rest. Therefore, a detailed NMS diagnosis can be made by examining AC activity levels in blood taken at rest time.
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Affiliation(s)
- Tomoyoshi Komiyama
- Department of Clinical Pharmacology, Tokai University School of Medicine, 143 Shimokasuya, Isehara, Kanagawa, Japan
- * E-mail:
| | - Eiichiro Nagata
- Department of Neurology, Tokai University School of Medicine, 143 Shimokasuya, Isehara, Kanagawa, Japan
| | - Tadashi Hashida
- Department of Cardiovascular Internal Medicine, Tokai University School of Medicine, 143 Shimokasuya, Isehara, Kanagawa, Japan
| | - Susumu Sakama
- Department of Cardiovascular Internal Medicine, Tokai University School of Medicine, 143 Shimokasuya, Isehara, Kanagawa, Japan
| | - Kengo Ayabe
- Department of Cardiovascular Internal Medicine, Tokai University School of Medicine, 143 Shimokasuya, Isehara, Kanagawa, Japan
| | - Hiroshi Kamiguchi
- Support Center for Medical Research and Education, Tokai University, 143 Shimokasuya, Isehara, Kanagawa, Japan
| | - Ayumi Sasaki
- Support Center for Medical Research and Education, Tokai University, 143 Shimokasuya, Isehara, Kanagawa, Japan
| | - Koichiro Yoshioka
- Department of Cardiovascular Internal Medicine, Tokai University School of Medicine, 143 Shimokasuya, Isehara, Kanagawa, Japan
| | - Hiroyuki Kobayashi
- Department of Clinical Pharmacology, Tokai University School of Medicine, 143 Shimokasuya, Isehara, Kanagawa, Japan
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Baumann F, Bauer MS, Rees M, Alexandrovich A, Gautel M, Pippig DA, Gaub HE. Increasing evidence of mechanical force as a functional regulator in smooth muscle myosin light chain kinase. eLife 2017; 6. [PMID: 28696205 PMCID: PMC5505704 DOI: 10.7554/elife.26473] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 06/20/2017] [Indexed: 11/18/2022] Open
Abstract
Mechanosensitive proteins are key players in cytoskeletal remodeling, muscle contraction, cell migration and differentiation processes. Smooth muscle myosin light chain kinase (smMLCK) is a member of a diverse group of serine/threonine kinases that feature cytoskeletal association. Its catalytic activity is triggered by a conformational change upon Ca2+/calmodulin (Ca2+/CaM) binding. Due to its significant homology with the force-activated titin kinase, smMLCK is suspected to be also regulatable by mechanical stress. In this study, a CaM-independent activation mechanism for smMLCK by mechanical release of the inhibitory elements is investigated via high throughput AFM single-molecule force spectroscopy. The characteristic pattern of transitions between different smMLCK states and their variations in the presence of different substrates and ligands are presented. Interaction between kinase domain and regulatory light chain (RLC) substrate is identified in the absence of CaM, indicating restored substrate-binding capability due to mechanically induced removal of the auto-inhibitory regulatory region. DOI:http://dx.doi.org/10.7554/eLife.26473.001
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Affiliation(s)
- Fabian Baumann
- Chair for Applied Physics and Center for Nanoscience, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Magnus Sebastian Bauer
- Chair for Applied Physics and Center for Nanoscience, Ludwig-Maximilians-Universität München, Munich, Germany.,Center for Integrated Protein Science Munich, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Martin Rees
- Randall Division of Cell and Molecular Biophysics, King's College London BHF Centre of Research Excellence, London, United Kingdom
| | - Alexander Alexandrovich
- Randall Division of Cell and Molecular Biophysics, King's College London BHF Centre of Research Excellence, London, United Kingdom
| | - Mathias Gautel
- Randall Division of Cell and Molecular Biophysics, King's College London BHF Centre of Research Excellence, London, United Kingdom
| | - Diana Angela Pippig
- Chair for Applied Physics and Center for Nanoscience, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Hermann Eduard Gaub
- Chair for Applied Physics and Center for Nanoscience, Ludwig-Maximilians-Universität München, Munich, Germany
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Khapchaev AY, Shirinsky VP. Myosin Light Chain Kinase MYLK1: Anatomy, Interactions, Functions, and Regulation. BIOCHEMISTRY (MOSCOW) 2017; 81:1676-1697. [PMID: 28260490 DOI: 10.1134/s000629791613006x] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
This review discusses and summarizes the results of molecular and cellular investigations of myosin light chain kinase (MLCK, MYLK1), the key regulator of cell motility. The structure and regulation of a complex mylk1 gene and the domain organization of its products is presented. The interactions of the mylk1 gene protein products with other proteins and posttranslational modifications of the mylk1 gene protein products are reviewed, which altogether might determine the role and place of MLCK in physiological and pathological reactions of cells and entire organisms. Translational potential of MLCK as a drug target is evaluated.
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Affiliation(s)
- A Y Khapchaev
- Russian Cardiology Research and Production Center, Moscow, 121552, Russia.
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Marchenko OO, Das S, Yu J, Novak IL, Rodionov VI, Efimova N, Svitkina T, Wolgemuth CW, Loew LM. A minimal actomyosin-based model predicts the dynamics of filopodia on neuronal dendrites. Mol Biol Cell 2017; 28:1021-1033. [PMID: 28228546 PMCID: PMC5391179 DOI: 10.1091/mbc.e16-06-0461] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 12/15/2016] [Accepted: 02/13/2017] [Indexed: 11/22/2022] Open
Abstract
A combination of computational and experimental approaches is used to show that the complex dynamics of dendritic filopodia, which is essential for synaptogenesis, is explained by a conceptually simple interplay among actin retrograde flow, myosin contractility, and substrate adhesion. Dendritic filopodia are actin-filled dynamic subcellular structures that sprout on neuronal dendrites during neurogenesis. The exploratory motion of the filopodia is crucial for synaptogenesis, but the underlying mechanisms are poorly understood. To study filopodial motility, we collected and analyzed image data on filopodia in cultured rat hippocampal neurons. We hypothesized that mechanical feedback among the actin retrograde flow, myosin activity, and substrate adhesion gives rise to various filopodial behaviors. We formulated a minimal one-dimensional partial differential equation model that reproduced the range of observed motility. To validate our model, we systematically manipulated experimental correlates of parameters in the model: substrate adhesion strength, actin polymerization rate, myosin contractility, and the integrity of the putative microtubule-based barrier at the filopodium base. The model predicts the response of the system to each of these experimental perturbations, supporting the hypothesis that our actomyosin-driven mechanism controls dendritic filopodia dynamics.
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Affiliation(s)
- Olena O Marchenko
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, CT 06030
| | - Sulagna Das
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, New York, NY 10461
| | - Ji Yu
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, CT 06030
| | - Igor L Novak
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, CT 06030
| | - Vladimir I Rodionov
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, CT 06030
| | - Nadia Efimova
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104
| | - Tatyana Svitkina
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104
| | - Charles W Wolgemuth
- Departments of Physics and Molecular and Cellular Biology, University of Arizona, Tucson, AZ 85721
| | - Leslie M Loew
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, CT 06030
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Alcala DB, Haldeman BD, Brizendine RK, Krenc AK, Baker JE, Rock RS, Cremo CR. Myosin light chain kinase steady-state kinetics: comparison of smooth muscle myosin II and nonmuscle myosin IIB as substrates. Cell Biochem Funct 2016; 34:469-474. [PMID: 27528075 DOI: 10.1002/cbf.3209] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2016] [Revised: 07/07/2016] [Accepted: 07/11/2016] [Indexed: 01/31/2023]
Abstract
Myosin light chain kinase (MLCK) phosphorylates S19 of the myosin regulatory light chain (RLC), which is required to activate myosin's ATPase activity and contraction. Smooth muscles are known to display plasticity in response to factors such as inflammation, developmental stage, or stress, which lead to differential expression of nonmuscle and smooth muscle isoforms. Here, we compare steady-state kinetics parameters for phosphorylation of different MLCK substrates: (1) nonmuscle RLC, (2) smooth muscle RLC, and heavy meromyosin subfragments of (3) nonmuscle myosin IIB, and (4) smooth muscle myosin II. We show that MLCK has a ~2-fold higher kcat for both smooth muscle myosin II substrates compared with nonmuscle myosin IIB substrates, whereas Km values were very similar. Myosin light chain kinase has a 1.6-fold and 1.5-fold higher specificity (kcat /Km ) for smooth versus nonmuscle-free RLC and heavy meromyosin, respectively, suggesting that differences in specificity are dictated by RLC sequences. Of the 10 non-identical RLC residues, we ruled out 7 as possible underlying causes of different MLCK kinetics. The remaining 3 residues were found to be surface exposed in the N-terminal half of the RLC, consistent with their importance in substrate recognition. These data are consistent with prior deletion/chimera studies and significantly add to understanding of MLCK myosin interactions. SIGNIFICANCE OF THE STUDY Phosphorylation of nonmuscle and smooth muscle myosin by myosin light chain kinase (MLCK) is required for activation of myosin's ATPase activity. In smooth muscles, nonmuscle myosin coexists with smooth muscle myosin, but the two myosins have very different chemo-mechanical properties relating to their ability to maintain force. Differences in specificity of MLCK for different myosin isoforms had not been previously investigated. We show that the MLCK prefers smooth muscle myosin by a significant factor. These data suggest that nonmuscle myosin is phosphorylated more slowly than smooth muscle myosin during a contraction cycle.
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Affiliation(s)
- Diego B Alcala
- Department of Pharmacology, University of Nevada Reno School of Medicine, Reno, Nevada, USA
| | - Brian D Haldeman
- Department of Pharmacology, University of Nevada Reno School of Medicine, Reno, Nevada, USA
| | - Richard K Brizendine
- Department of Pharmacology, University of Nevada Reno School of Medicine, Reno, Nevada, USA
| | - Agata K Krenc
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois, USA
| | - Josh E Baker
- Department of Pharmacology, University of Nevada Reno School of Medicine, Reno, Nevada, USA
| | - Ronald S Rock
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois, USA
| | - Christine R Cremo
- Department of Pharmacology, University of Nevada Reno School of Medicine, Reno, Nevada, USA.
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Hong F, Brizendine RK, Carter MS, Alcala DB, Brown AE, Chattin AM, Haldeman BD, Walsh MP, Facemyer KC, Baker JE, Cremo CR. Diffusion of myosin light chain kinase on actin: A mechanism to enhance myosin phosphorylation rates in smooth muscle. J Biophys Biochem Cytol 2015. [DOI: 10.1083/jcb.2111oia229] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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