PIEZO2 mediates injury-induced tactile pain in mice and humans

Tissue injury and inflammation markedly alter touch perception, making normally innocuous sensations become intensely painful. Although this sensory distortion, known as tactile allodynia, is one of the most common types of pain, the mechanism by which gentle mechanical stimulation becomes unpleasant remains enigmatic. The stretch-gated ion channel PIEZO2 has been shown to mediate light touch, vibration detection, and proprioception. However, the role of this ion channel in nociception and pain has not been resolved. Here, we examined the importance of Piezo2 in the cellular representation of mechanosensation using in vivo imaging in mice. Piezo2-knockout neurons were completely insensitive to gentle dynamic touch but still responded robustly to noxious pinch. During inflammation and after injury, Piezo2 remained essential for detection of gentle mechanical stimuli. We hypothesized that loss of PIEZO2 might eliminate tactile allodynia in humans. Our results show that individuals with loss-of-function mutations in PIEZO2 completely failed to develop sensitization and painful reactions to touch after skin inflammation. These findings provide insight into the basis for tactile allodynia, identify the PIEZO2 mechanoreceptor as an essential mediator of touch under inflammatory conditions, and suggest that this ion channel might be targeted for treating tactile allodynia.

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Lipoxins and aspirin-triggered lipoxin inhibit inflammatory pain processing

Journal of Experimental Medicine ◽

10.1084/jem.20061826 ◽

2007 ◽

Vol 204 (2) ◽

pp. 245-252 ◽

Cited By ~ 114

Author(s):

Camilla I. Svensson ◽

Michela Zattoni ◽

Charles N. Serhan

Keyword(s):

Tissue Injury ◽

Spinal Pain ◽

Pain Processing ◽

Lipoxin A4 ◽

Inflammatory Conditions ◽

Extracellular Signal ◽

Inflammatory State

Inflammatory conditions can lead to debilitating and persistent pain. This hyperalgesia reflects sensitization of peripheral terminals and facilitation of pain signaling at the spinal level. Studies of peripheral systems show that tissue injury triggers not only inflammation but also a well-orchestrated series of events that leads to reversal of the inflammatory state. In this regard, lipoxins represent a unique class of lipid mediators that promote resolution of inflammation. The antiinflammatory role of peripheral lipoxins raises the hypothesis that similar neuraxial systems may also down-regulate injury-induced spinal facilitation of pain processing. We report that the lipoxin A4 receptor is expressed on spinal astrocytes both in vivo and in vitro and that spinal delivery of lipoxin A4, as well as stable analogues, attenuates inflammation-induced pain. Furthermore, activation of extracellular signal-regulated kinase and c-Jun N-terminal kinase in astrocytes, which has been indicated to play an important role in spinal pain processing, was attenuated in the presence of lipoxins. This linkage opens the possibility that lipoxins regulate spinal nociceptive processing though their actions upon astrocytic activation. Targeting mechanisms that counterregulate the spinal consequences of persistent peripheral inflammation provide a novel endogenous mechanism by which chronic pain may be controlled.

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Cannabinoids in the Pathophysiology of Skin Inflammation

Molecules ◽

10.3390/molecules25030652 ◽

2020 ◽

Vol 25 (3) ◽

pp. 652 ◽

Cited By ~ 5

Author(s):

Cristian Scheau ◽

Ioana Anca Badarau ◽

Livia-Gratiela Mihai ◽

Andreea-Elena Scheau ◽

Daniel Octavian Costache ◽

...

Keyword(s):

Inflammatory Diseases ◽

Synthetic Cannabinoids ◽

Skin Inflammation ◽

Cellular Mechanisms ◽

Inflammatory Conditions ◽

Early Results ◽

Inflammatory Component

Cannabinoids are increasingly-used substances in the treatment of chronic pain, some neuropsychiatric disorders and more recently, skin disorders with an inflammatory component. However, various studies cite conflicting results concerning the cellular mechanisms involved, while others suggest that cannabinoids may even exert pro-inflammatory behaviors. This paper aims to detail and clarify the complex workings of cannabinoids in the molecular setting of the main dermatological inflammatory diseases, and their interactions with other substances with emerging applications in the treatment of these conditions. Also, the potential role of cannabinoids as antitumoral drugs is explored in relation to the inflammatory component of skin cancer. In vivo and in vitro studies that employed either phyto-, endo-, or synthetic cannabinoids were considered in this paper. Cannabinoids are regarded with growing interest as eligible drugs in the treatment of skin inflammatory conditions, with potential anticancer effects, and the readiness in monitoring of effects and the facility of topical application may contribute to the growing support of the use of these substances. Despite the promising early results, further controlled human studies are required to establish the definitive role of these products in the pathophysiology of skin inflammation and their usefulness in the clinical setting.

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Mechanosensitive Ion Channel Piezo1 Regulates Myocyte Fusion during Skeletal Myogenesis

10.1101/2020.09.27.315242 ◽

2020 ◽

Author(s):

Huascar Pedro Ortuste Quiroga ◽

Shingo Yokoyama ◽

Massimo Ganassi ◽

Kodai Nakamura ◽

Tomohiro Yamashita ◽

...

Keyword(s):

Ion Channel ◽

Molecular Mechanisms ◽

Myoblast Fusion ◽

Mechanical Stimuli ◽

Muscle Satellite Cell ◽

Myotube Formation ◽

Mechanosensitive Ion Channel ◽

And Function ◽

Sirna Knockdown

AbstractMechanical stimuli such as stretch and resistance training are essential to regulate growth and function of skeletal muscle. However, the molecular mechanisms involved in sensing mechanical stress remain unclear. Here, the purpose of this study was to investigate the role of the mechanosensitive ion channel Piezo1 during myogenic progression. Muscle satellite cell-derived myoblasts and myotubes were modified with stretch, siRNA knockdown and agonist-induced activation of Piezo1. Direct manipulation of Piezo1 modulates terminal myogenic progression. Piezo1 knockdown suppressed myoblast fusion during myotube formation and maturation. This was accompanied by downregulation of the fusogenic protein Myomaker. Piezo1 knockdown also lowered Ca2+ influx in response to stretch. Conversely Piezo1 activation stimulated fusion and increased Ca2+ influx in response to stretch. These evidences indicate that Piezo1 is essential for myotube formation and maturation, which may have implications for msucular dystrophy prevention through its role as a mechanosensitive Ca2+ channel.

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Loss of keratin 6 (K6) proteins reveals a function for intermediate filaments during wound repair

The Journal of Cell Biology ◽

10.1083/jcb.200305032 ◽

2003 ◽

Vol 163 (2) ◽

pp. 327-337 ◽

Cited By ~ 146

Author(s):

Pauline Wong ◽

Pierre A. Coulombe

Keyword(s):

Gene Expression ◽

Wound Repair ◽

Tissue Injury ◽

Blood Clot ◽

Explant Culture ◽

Null Mouse ◽

Actin Organization ◽

Mammalian Tissues

The ability to heal wounds is vital to all organisms. In mammalian tissues, alterations in intermediate filament (IF) gene expression represent an early reaction of cells surviving injury. We investigated the role of keratin IFs during the epithelialization of skin wounds using a keratin 6α and 6β (K6α/K6β)-null mouse model. In skin explant culture, null keratinocytes exhibit an enhanced epithelialization potential due to increased migration. The extent of the phenotype is strain dependent, and is accompanied by alterations in keratin IF and F-actin organization. However, in wounded skin in vivo, null keratinocytes rupture as they attempt to migrate under the blood clot. Fragility of the K6α/K6β-null epidermis is confirmed when applying trauma to chemically treated skin. We propose that the alterations in IF gene expression after tissue injury foster a compromise between the need to display the cellular pliability necessary for timely migration and the requirement for resilience sufficient to withstand the rigors of a wound site.

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Dynamic measurement of cytosolic pH and [NO3−] uncovers the role of the vacuolar transporter AtCLCa in cytosolic pH homeostasis

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2007580117 ◽

2020 ◽

Vol 117 (26) ◽

pp. 15343-15353 ◽

Cited By ~ 2

Author(s):

Elsa Demes ◽

Laetitia Besse ◽

Paloma Cubero-Font ◽

Béatrice Satiat-Jeunemaitre ◽

Sébastien Thomine ◽

...

Keyword(s):

Chloride Channel ◽

Loss Of Function ◽

Ion Transporters ◽

Ph Homeostasis ◽

Cytosolic Ph ◽

Cellular Processes ◽

Plasma Membrane Proton Pump ◽

Cytosolic Acidification

Ion transporters are key players of cellular processes. The mechanistic properties of ion transporters have been well elucidated by biophysical methods. Meanwhile, the understanding of their exact functions in cellular homeostasis is limited by the difficulty of monitoring their activity in vivo. The development of biosensors to track subtle changes in intracellular parameters provides invaluable tools to tackle this challenging issue. AtCLCa (Arabidopsis thalianaChloride Channel a) is a vacuolar NO3−/H+exchanger regulating stomata aperture inA.thaliana. Here, we used a genetically encoded biosensor, ClopHensor, reporting the dynamics of cytosolic anion concentration and pH to monitor the activity of AtCLCa in vivo inArabidopsisguard cells. We first found that ClopHensor is not only a Cl−but also, an NO3−sensor. We were then able to quantify the variations of NO3−and pH in the cytosol. Our data showed that AtCLCa activity modifies cytosolic pH and NO3−. In an AtCLCa loss of function mutant, the cytosolic acidification triggered by extracellular NO3−and the recovery of pH upon treatment with fusicoccin (a fungal toxin that activates the plasma membrane proton pump) are impaired, demonstrating that the transport activity of this vacuolar exchanger has a profound impact on cytosolic homeostasis. This opens a perspective on the function of intracellular transporters of the Chloride Channel (CLC) family in eukaryotes: not only controlling the intraorganelle lumen but also, actively modifying cytosolic conditions.

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MiR199a is implicated in embryo implantation by regulating Grb10 in rat

Reproduction ◽

10.1530/rep-13-0290 ◽

2014 ◽

Vol 147 (1) ◽

pp. 91-99 ◽

Cited By ~ 12

Author(s):

Hong-Fei Xia ◽

Jing-Li Cao ◽

Xiao-Hua Jin ◽

Xu Ma

Keyword(s):

Cell Proliferation ◽

Embryo Implantation ◽

Growth Factor Receptor ◽

Inverse Association ◽

Loss Of Function ◽

Endometrial Stromal Cells ◽

Proliferation And Apoptosis ◽

17Β Estradiol

MiR199a was found to be differentially expressed in rat uteri between the prereceptive and receptive phase via microRNA (miRNA) microarray analysis in our previous study. However, the role of miR199a in rat embryo implantation remained unknown. In the study, northern blot results showed that the expression levels of miR199a were higher on gestation days 5 and 6 (g.d.5–6) in rat uteri than on g.d.3–4 and g.d.7–8. In situ localization of miR199a in rat uteri showed that miR199a was mainly localized in the stroma or decidua. The expression of miR199a was not significantly different in the uteri of pseudopregnant rats and evidently increased in the uteri of rats subjected to activation of delayed implantation and experimentally induced decidualization. Treatment with 17β-estradiol or both 17β-estradiol and progesterone significantly diminished miR199a levels. Gain of function of miR199a in endometrial stromal cells isolated from rat uteri inhibited cell proliferation and promoted cell apoptosis. Loss of function of miR199a displayed opposite roles on cell proliferation and apoptosis. Further investigation uncovered a significant inverse association between the expression of miR199a and growth factor receptor-bound protein 10 (Grb10), an imprinted gene, and miR199a could bind to the 3′UTR of Grb10 to inhibit Grb10 translation. In addition, in vivo analysis found that the immunostaining of GRB10 was attenuated in the stroma or decidua from g.d.4 to 6, contrary to the enhancement of miR199a. Collectively, upregulation of miR199a in rat uterus during the receptive phase is regulated by blastocyst activation and uterine decidualization. Enforced miR199a expression suppresses cell proliferation partially through targeting Grb10.

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Exposure to Mites Sensitizes Intestinal Stem Cell Maintenance, Splenic Marginal Zone B Cell Homeostasis, And Heart Development to Notch Dosage and Cooperativity

10.1101/2020.02.13.948224 ◽

2020 ◽

Cited By ~ 1

Author(s):

Francis M. Kobia ◽

Kristina Preusse ◽

Quanhui Dai ◽

Nicholas Weaver ◽

Praneet Chaturvedi ◽

...

Keyword(s):

B Cell ◽

Heart Development ◽

Marginal Zone ◽

B Cell Lymphoma ◽

Mite Infestation ◽

List Type ◽

Loss Of Function ◽

B Cell Homeostasis

AbstractCooperative DNA binding is a key feature of transcriptional regulation. Here we examined the role of cooperativity in Notch signaling by CRISPR-mediated engineering of mice in which neither Notch1 nor Notch2 can homo- or heterodimerize, essential for cooperative binding to sequence paired sites (SPS) located near many Notch-regulated genes. While most known Notch-dependent phenotypes were unaffected in Notch1/2 dimer-deficient mice, a subset of tissues proved highly sensitive to loss of cooperativity. These phenotypes include heart development, compromising viability in combination with low gene dose, and the gut, developing ulcerative colitis in response to 1% DSS. The most striking phenotypes – gender imbalance and splenic marginal zone B cell lymphoma – emerged in combination with dose reduction or when challenged by chronic fur mite infestation. This study highlights the role of the environment in malignancy and colitis, and is consistent with Notch-dependent anti-parasite immune responses being compromised in the dimer deficient animals.HighlightsNotch dimerization has an in vivo role in contributing to intestinal homeostasisLoss of cooperativity can manifest as Notch gain or loss of function phenotypesMite infestation exacerbates all phenotypes, triggers MZB hyperproliferation in mutant animalsMite-infested mutant mice develop SMZL with age

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Targeting NR4A Nuclear Receptors to Control Stromal Cell Inflammation, Metabolism, Angiogenesis, and Tumorigenesis

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2021.589770 ◽

2021 ◽

Vol 9 ◽

Cited By ~ 1

Author(s):

Daniel Crean ◽

Evelyn P. Murphy

Keyword(s):

Nuclear Receptors ◽

Cell Cycle Progression ◽

Stromal Cell ◽

Immune Cell ◽

Cycle Progression ◽

Cell Responses ◽

Inflammatory Conditions ◽

Health And Disease

The NR4A1–NR4A3 (Nur77, Nurr1, and Nor-1) subfamily of nuclear receptors is a group of immediate early genes induced by a pleiotropy of stimuli including peptide hormones, growth factors, cytokines, inflammatory, and physiological stimuli, and cellular stress. NR4A receptors function as potent sensors of changes in the cellular microenvironment to control physiological and pathological processes through genomic and non-genomic actions. NR4A receptors control metabolism and cardiovascular and neurological functions and mediate immune cell homeostasis in inflammation and cancer. This receptor subfamily is increasingly recognized as an important molecular connection between chronic inflammation, altered immune cell responses, and cancer development. In this review, we examine how transcriptome analysis identified NR4A1/NR4A2 receptors as transcriptional regulators in mesenchymal stromal cell (MSC) migration, cell cycle progression, and cytokine production to control local immune responses. In chronic inflammatory conditions, such as rheumatoid arthritis, NR4A receptors have been shown to modify the activity of MSC and fibroblast-like stromal cells to regulate synovial tissue hyperplasia, pathological angiogenesis, and cartilage turnover in vivo. Additionally, as NR4A1 has been observed as a major transcriptional regulator in tumor–stromal communication controlling tumorigenesis, we discuss how advances in the pharmacological control of these receptors lead to important new mechanistic insights into understanding the role of the tumor microenvironment in health and disease.

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P2X7 Receptor Blockade Protects Against Acrolein-Induced Bladder Damage: A Potential New Therapeutic Approach for the Treatment of Bladder Inflammatory Diseases

Frontiers in Pharmacology ◽

10.3389/fphar.2021.682520 ◽

2021 ◽

Vol 12 ◽

Author(s):

Zhinoos Taidi ◽

Tommy Zhou ◽

Kate H. Moore ◽

Kylie J. Mansfield ◽

Lu Liu

Keyword(s):

Oxidative Stress ◽

Urinary Bladder ◽

Receptor Antagonist ◽

P2x7 Receptor ◽

Ex Vivo ◽

Therapeutic Option ◽

Bladder Wall ◽

Loss Of Function ◽

Inflammatory Conditions

Inflammatory conditions of the urinary bladder have been shown to be associated with urothelial damage and loss of function. The purinergic P2X7 receptor has been implicated in several inflammatory conditions. The aim of this study was to investigate the role of the P2X7 receptor in acrolein-induced inflammatory damage using the porcine urinary bladder. For this purpose, an ex-vivo model of porcine urothelial damage induced by direct instillation of acrolein into the whole bladder lumen was used. To determine the role of the P2X7 receptor, the bladders were pre-incubated with a selective P2X7 receptor antagonist, A804598 (10 μM), for 1 h. The effects of the acrolein-induced urothelial damage on the bladder’s function were assessed by examining the bladder wall contractile response, structure changes, apoptosis, and oxidative stress in the bladder tissues. The acrolein treatment led to significant damage to the urothelium histology, tight junction expression, and contractile responses. Acrolein also induced apoptosis in the mucosa layer. All these acrolein-induced responses were attenuated by pre-treatment with the P2X7 receptor antagonist A804598. Acrolein also significantly induced DNA oxidation in the submucosal layer; however, the P2X7 receptor antagonism did not show any protective effect towards the acrolein-induced oxidative stress. These findings suggested that the P2X7 receptor is involved in the acrolein-induced damage to the urothelium; therefore, the P2X7 receptor antagonists may be a new therapeutic option for the treatment of bladder inflammation.

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L1CAM promotes ovarian cancer stemness and tumor initiation via FGFR1/SRC/STAT3 signaling

Journal of Experimental & Clinical Cancer Research ◽

10.1186/s13046-021-02117-z ◽

2021 ◽

Vol 40 (1) ◽

Author(s):

Marco Giordano ◽

Alessandra Decio ◽

Chiara Battistini ◽

Micol Baronio ◽

Fabrizio Bianchi ◽

...

Keyword(s):

Molecular Mechanisms ◽

Genetic Manipulation ◽

Tumor Formation ◽

In Vitro Assays ◽

Tumor Initiation ◽

Loss Of Function ◽

Stat3 Signaling

Abstract Background Cancer stem cells (CSC) have been implicated in tumor progression. In ovarian carcinoma (OC), CSC drive tumor formation, dissemination and recurrence, as well as drug resistance, thus contributing to the high death-to-incidence ratio of this disease. However, the molecular basis of such a pathogenic role of ovarian CSC (OCSC) has been elucidated only to a limited extent. In this context, the functional contribution of the L1 cell adhesion molecule (L1CAM) to OC stemness remains elusive. Methods The expression of L1CAM was investigated in patient-derived OCSC. The genetic manipulation of L1CAM in OC cells provided gain and loss-of-function models that were then employed in cell biological assays as well as in vivo tumorigenesis experiments to assess the role of L1CAM in OC cell stemness and in OCSC-driven tumor initiation. We applied antibody-mediated neutralization to investigate L1CAM druggability. Biochemical approaches were then combined with functional in vitro assays to study the molecular mechanisms underlying the functional role of L1CAM in OCSC. Results We report that L1CAM is upregulated in patient-derived OCSC. Functional studies showed that L1CAM promotes several stemness-related properties in OC cells, including sphere formation, tumor initiation and chemoresistance. These activities were repressed by an L1CAM-neutralizing antibody, pointing to L1CAM as a druggable target. Mechanistically, L1CAM interacted with and activated fibroblast growth factor receptor-1 (FGFR1), which in turn induced the SRC-mediated activation of STAT3. The inhibition of STAT3 prevented L1CAM-dependent OC stemness and tumor initiation. Conclusions Our study implicate L1CAM in the tumorigenic function of OCSC and point to the L1CAM/FGFR1/SRC/STAT3 signaling pathway as a novel driver of OC stemness. We also provide evidence that targeting this pathway can contribute to OC eradication.

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