Chatting with the neighbors: crosstalk between Rho-kinase (ROCK) and other signaling pathways for treatment of neurological disorders

The mechanisms of Ca2+ handling and sensitization were investigated in human small omental arteries exposed to norepinephrine (NE) and to the thromboxane A2 analog U-46619. Contractions elicited by NE and U-46619 were associated with an increase in intracellular Ca2+ concentration ([Ca2+]i), an increase in Ca2+-independent signaling pathways, or an enhancement of the sensitivity of the myofilaments to Ca2+. The two latter pathways were abolished by protein kinase C (PKC), tyrosine kinase (TK), and Rho-associated protein kinase (ROK) inhibitors. In Ca2+-free medium, both NE and U-46619 elicited an increase in tension that was greatly reduced by PKC inhibitors and abolished by caffeine or ryanodine. After depletion of Ca2+ stores with NE and U-46619 in Ca2+-free medium, addition of CaCl2 in the continuous presence of the agonists produced increases in [Ca2+]i and contractions that were inhibited by nitrendipine and TK inhibitors but not affected by PKC inhibitors. NE and U-46619 induced tyrosine phosphorylation of a 42- or a 58-kDa protein, respectively. These results indicate that the mechanisms leading to contraction elicited by NE and U-46619 in human small omental arteries are composed of Ca2+ release from ryanodine-sensitive stores, Ca2+ influx through nitrendipine-sensitive channels, and Ca2+ sensitization and/or Ca2+-independent pathways. They also show that the TK pathway is involved in the tonic contraction associated with Ca2+ entry, whereas TK, PKC, and ROK mechanisms regulate Ca2+-independent signaling pathways or Ca2+sensitization.

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Lipopolysaccharide induced altered signaling pathways in various neurological disorders

Naunyn-Schmiedeberg s Archives of Pharmacology ◽

10.1007/s00210-021-02198-9 ◽

2022 ◽

Author(s):

Sukhdev Singh ◽

Kuleshwar Sahu ◽

Charan Singh ◽

Arti Singh

Keyword(s):

Signaling Pathways ◽

Neurological Disorders

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Regulation of Cyr61 gene expression by mechanical stretch through multiple signaling pathways

AJP Cell Physiology ◽

10.1152/ajpcell.2001.281.5.c1524 ◽

2001 ◽

Vol 281 (5) ◽

pp. C1524-C1532 ◽

Cited By ~ 62

Author(s):

Isao Tamura ◽

Joel Rosenbloom ◽

Edward Macarak ◽

Brahim Chaqour

Keyword(s):

Gene Expression ◽

Signaling Pathways ◽

Rho Kinase ◽

Mechanical Stretch ◽

Selective Inhibition ◽

Early Gene ◽

Actin Dynamics ◽

Mrna Levels ◽

Bladder Smooth Muscle ◽

Pharmacological Agents

The cysteine-rich protein 61 (Cyr61) is a signaling molecule with functions in cell migration, adhesion, and proliferation. This protein is encoded by an immediate early gene whose expression is mainly induced by serum growth factors. Here we show that Cyr61 mRNA levels increase sharply in response to cyclic mechanical stretch applied to cultured bladder smooth muscle cells. Stretch-induced changes of Cyr61 transcripts were transient and accompanied by an increase of the encoded protein that localized mainly to the cytoplasm and nucleus of the cells. With the use of pharmacological agents that interfere with known signaling pathways, we show that transduction mechanisms involving protein kinase C and phosphatidylinositol 3-kinase activation partly blocked stretch-induced Cyr61 gene expression. Selective inhibition of Rho kinase pathways altered this stretch effect as well. Meanwhile, using inhibitors of the actin cytoskeleton, we show that Cyr61 gene expression is sensitive to mechanisms that sense actin dynamics. These results establish the regulation of Cyr61 gene by mechanical stretch and provide clues to the key signaling molecules involved in this process.

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Oxidized low-density lipoproteins induce rapid platelet activation and shape change through tyrosine kinase and Rho kinase–signaling pathways

Blood ◽

10.1182/blood-2013-04-491688 ◽

2013 ◽

Vol 122 (4) ◽

pp. 580-589 ◽

Cited By ~ 43

Author(s):

Katie S. Wraith ◽

Simbarashe Magwenzi ◽

Ahmed Aburima ◽

Yichuan Wen ◽

David Leake ◽

...

Keyword(s):

Signaling Pathways ◽

Platelet Activation ◽

Shape Change ◽

Oxidized Ldl ◽

Rapid Change ◽

Rho Kinase ◽

Low Density Lipoproteins ◽

Low Density ◽

Key Points ◽

Platelet Shape

Key Points Oxidized LDL stimulates rapid change in platelet shape through ligation of CD36. Ligation of CD36 by oxidized LDL simultaneously activates tyrosine and Rho kinase–dependent signaling pathways.

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Rho kinase, a promising drug target for neurological disorders

Nature Reviews Drug Discovery ◽

10.1038/nrd1719 ◽

2005 ◽

Vol 4 (5) ◽

pp. 387-398 ◽

Cited By ~ 386

Author(s):

Bernhard K. Mueller ◽

Helmut Mack ◽

Nicole Teusch

Keyword(s):

Neurological Disorders ◽

Drug Target ◽

Rho Kinase ◽

Kinase A

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Airway smooth muscle excitation-contraction coupling and airway hyperresponsiveness

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y05-070 ◽

2005 ◽

Vol 83 (8-9) ◽

pp. 725-732 ◽

Cited By ~ 15

Author(s):

Simon Hirota ◽

Peter B Helli ◽

Adriana Catalli ◽

Allyson Chew ◽

Luke J Janssen

Keyword(s):

Smooth Muscle ◽

Vascular Smooth Muscle ◽

Signaling Pathways ◽

Airway Smooth Muscle ◽

Airway Hyperresponsiveness ◽

Rho Kinase ◽

Shortness Of Breath ◽

Excitation Contraction Coupling ◽

Contraction Coupling ◽

Hallmark Feature

The primary complaints from patients with asthma pertain to function of airway smooth muscle (ASM) function including shortness of breath, wheezing, and coughing. Thus, it is imperative to better understand the mechanisms underlying excitation-contraction coupling in ASM. Here, we review the various signaling pathways underlying contraction in ASM, and then examine how these are altered in asthma and airway hyperresponsiveness (a hallmark feature of asthma). Throughout, we highlight how studies of vascular smooth muscle have helped or hindered progress in understanding ASM physiology and pathophysiology.Key words: airway smooth muscle, vascular smooth muscle, excitation-contraction coupling, calcium, Rho-kinase.

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Characterization of an eutherian gene cluster generated after transposon domestication identifies Bex3 as relevant for advanced neurological functions

Genome Biology ◽

10.1186/s13059-020-02172-3 ◽

2020 ◽

Vol 21 (1) ◽

Author(s):

Enrique Navas-Pérez ◽

Cristina Vicente-García ◽

Serena Mirra ◽

Demian Burguera ◽

Noèlia Fernàndez-Castillo ◽

...

Keyword(s):

Signaling Pathways ◽

Gene Cluster ◽

Neurological Disorders ◽

Evolutionary Process ◽

Brain Functions ◽

Molecular Domestication ◽

Multigenic Family ◽

Neurological Features ◽

And Function ◽

Higher Brain Functions

Abstract Background One of the most unusual sources of phylogenetically restricted genes is the molecular domestication of transposable elements into a host genome as functional genes. Although these kinds of events are sometimes at the core of key macroevolutionary changes, their origin and organismal function are generally poorly understood. Results Here, we identify several previously unreported transposable element domestication events in the human and mouse genomes. Among them, we find a remarkable molecular domestication that gave rise to a multigenic family in placental mammals, the Bex/Tceal gene cluster. These genes, which act as hub proteins within diverse signaling pathways, have been associated with neurological features of human patients carrying genomic microdeletions in chromosome X. The Bex/Tceal genes display neural-enriched patterns and are differentially expressed in human neurological disorders, such as autism and schizophrenia. Two different murine alleles of the cluster member Bex3 display morphological and physiopathological brain modifications, such as reduced interneuron number and hippocampal electrophysiological imbalance, alterations that translate into distinct behavioral phenotypes. Conclusions We provide an in-depth understanding of the emergence of a gene cluster that originated by transposon domestication and gene duplication at the origin of placental mammals, an evolutionary process that transformed a non-functional transposon sequence into novel components of the eutherian genome. These genes were integrated into existing signaling pathways involved in the development, maintenance, and function of the CNS in eutherians. At least one of its members, Bex3, is relevant for higher brain functions in placental mammals and may be involved in human neurological disorders.

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The Mevalonate Pathway and Downstream Signal Transducers As Therapeutic Targets to Overcome Multidrug Resistance in Chronic Lymphocytic Leukemia (CLL)

Blood ◽

10.1182/blood.v120.21.3881.3881 ◽

2012 ◽

Vol 120 (21) ◽

pp. 3881-3881

Author(s):

Marta Coscia ◽

Micol Rigoni ◽

Chiara Riganti ◽

Candida Vitale ◽

Ivana Campia ◽

...

Keyword(s):

Cell Death ◽

Multidrug Resistance ◽

Chronic Lymphocytic Leukemia ◽

Signaling Pathways ◽

Stromal Cells ◽

Active Form ◽

Rho Kinase ◽

Lymphocytic Leukemia ◽

Pathway Activity ◽

Downstream Signaling

Abstract Abstract 3881 Background: The mutational status of tumor immunoglobulin heavy chain variable region (IGHV) is a reliable prognosticator in chronic lymphocytic leukemia (CLL): patients with unmutated (UM) IGHV have a worse prognosis than patients with mutated (M) IGHV. The tumor microenvironment actively supports the survival of CLL cells and confers a multidrug resistance (MDR) phenotype to CLL cells. MDR is due to the over-expression of membrane transporters, like P-glycoprotein (Pgp), which actively extrudes several anticancer drugs. Pgp is under the positive control of the transcription factor Hypoxia-Inducible-Factor-1-alfa (HIF-1α) which is activated by isoprenylated Ras/Rho-dependent downstream signaling pathways. Ras and Rho isoprenylation are regulated by the mevalonate (Mev) pathway activity suggesting that this pathway can be exploited as a metabolic checkpoint to regulate chemresistance. Aim: The aim of this study was twofold: 1) to investigate the correlation between chemoresistance and the activity of the Mev pathway and Ras/Rho-A downstream signaling pathways in purified M and UM CLL cells under basal conditions and after incubation with stromal cells; 2) to evaluate the chemosensitizing effects of agents specifically targeting the Mev pathway and downstream signaling pathways under the same culture conditions. Methods: M and UM CLL cells were cultured in the presence and in the absence of murine stromal cells (M210B4) and exposed to Zoledronic acid (ZA) (1 μmol/L), Simvastatine (Sim) (1 μmol/L), ERK1/2 kinase inhibitor PD98059 (10 μmol/L), HIF-1α inhibitor YC-1 (10 μmol/L) and Doxorubicine (Doxo) (1 μmol/L). The Mev pathway activity was measured by cells radiolabelling with [14C]-mevalonic acid and thin layer chromatography. Ras, ERK1/2 and Akt activity were detected by Western blot. Rho, Rho Kinase and HIF-1α activity were assessed by ELISA. Mdr1 expression was measured by Real Time-PCR. PgP activity was evaluated by measuring Doxo intracellular accumulation. Doxo cytotoxicity was assessed by annexin V and propidium iodide staining. Results: The Mev pathway is significantly more active in UM than in M CLL cells. This hypermetabolic activity translates into a higher activation of Ras/Akt and Rho/Rho kinase signaling pathways and higher expression of the phosphorylated active form of HIF-1α. HIF-1α activation positively regulates mdr1 gene expression in UM CLL cells leading to a more effective Doxo extrusion and therefore better survival upon Doxo exposure. M210B4 stromal cells further protect UM CLL cells from Doxo induced cell death by upregulating Mev pathway activity, HIF-1α/mdr1/PgP axis activation, and Doxo extrusion. Targeting the Mev pathway of UM cells with ZA and Mev reduces the basal activity of HIF-1α/mdr1/PgP axis and significantly increases Doxo retention and cytotoxicity. Similar effects are obtained with PD85 and YC1–10 which are specific inhibitors of the downstream molecules ERK-1/2 and HIF-1α, respectively. All these agents are able to overcome the protective effect exerted by stromal cells by significantly increasing PgP activity and Doxo-induced cell death. Conclusions: Our data demonstrate that the Ras- and Rho-dependent HIF-1α/mdr1/PgP axis is more active and associated with higher levels of MDR in UM compared with M CLL cells. Targeting the Mev pathway and/or downstream signalling pathways is a promising strategy to circumvent basal and stroma-mediated chemoresistance especially in UM CLL cells. Disclosures: Massaia: Novartis Farma S.p.A: Honoraria, Research Funding.

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