previous projects

Role of kinin receptors B1 and B2 in the generation and inhibition of pain

Cecile Cayla

Kinins are produced in response to tissue trauma and inflammation and are involved in the initiation of pain and in the development of hypersensitivity. They act through two G protein coupled receptors, the constitutively expressed B2 receptor and the injury-induced B1 receptor. Our major research interest is to better understand the role of kinins in painful processes and answer the following questions: 

·         What are their overall contributions to hypersensitivity and pain?

·         What are the specific roles of each receptor?

·         Are kinin receptors also involved in antihyperalgesic mechanisms associated with inflammation and injury?

Group members involved: Katharina Kuschfeldt, Barbara Trampenau, Dominika Labuz

Collaborator: M. Bader (MDC, Berlin-Buch)

Funding: DFG, CA 793/1-1 (C. Cayla)

Publications:

Cayla C, Todiras M, Iliescu R, Saul VV, Gross V, Pilz B, Chai G, Merino VF, Pesquero JB, Baltatu OC, Bader M.
Mice deficient for both kinin receptors are normotensive and protected from endotoxin- induced hypotension.
FASEB J. 2007; 21:1689-1698.
Cayla C, Labuz D, Machelska H, Bader M, Schäfer M, Stein C.
Impaired nociception and peripheral opioid antinociception in mice lacking both kinin B1 and B2 receptors. .
Anesthesiology 2012; 116(2):448-57 .

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Immune cell-derived opioids and neuropathic pain

Halina Machelska

Neuropathic pain is a common consequence of peripheral nerve injuries such as amputation, diabetes, entrapment or compression, and represents one of the most devastating forms of chronic pain. This pain can persist long after the initiating nerve damaging event has healed, and is often refractory to conventional treatments. In addition to neuronal changes the activation of the immune system as a component of nerve injury is gaining increasing attention. The prevalent opinion points to immune cells as generators of neuropathic pain. In contrast, we have shown that leukocytes (CD45+ hematopoetic cells) containing opioid peptides contribute to the attenuation of pain in neuritis. In a model of neuropathic pain we demonstrated that these cells infiltrate the site of nerve damage. Following application of corticotropin-releasing factor (CRF) the immune cells secrete opioid peptides (beta-endorphin, Met-enkephalin, dynorphin A), which activate local neuronal opioid receptors (mu, delta, kappa) to produce analgesia. Moreover, we found that T lymphocytes represent an essential CD45+ cell population, which mediates analgesia in advanced neuropathy. These data define opioid peptide-containing immune cells as a new component of beneficial effects of neuroinflammation. 

Group members involved: Dominika Labuz, Yvonne Schmidt, Anja Schreiter

Funding: DFG, KFO 100/2, Project 1, MA 2437/1-4 (H. Machelska)

Publications:

Labuz D, Schmidt Y, Schreiter A, Rittner HL, Mousa SA, Machelska H.
Immune cell-derived opioids protect against neuropathic pain.
J Clin Invest 2009; 119(2):278-286.
Labuz D, Schreiter A, Schmidt Y, Brack A, Machelska H.
T lymphocytes containing β-endorphin ameliorate mechanical hypersensitivity following nerve injury .
Brain Behav Immun 2010 ; 24(7): 1045-53 .
Stein C, Machelska H
Modulation of peripheral sensory neurons by the immune system: implications for pain therapy.
Pharmacol Rev 2011; 63(4):860-81.
Machelska H.
Control of neuropathic pain by immune cells and opioids..
CNS Neurol Disord Drug Targets 2011; 10(5):559-70.
Machelska H
Dual peripheral actions of immune cells in neuropathic pain..
Arch Immunol Ther Exp (Warsz) 2011; 59(1):11-24.

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Enhancement of endogenous opioid function in experimental inflammatory pain

Halina Machelska, Christoph Stein

This project explores novel ways of pain control without adverse effects associated with classical anti-inflammatory drugs and centrally acting opioids. Immune cells infiltrating inflamed tissue produce and release opioid peptides. These peptides activate opioid receptors on peripheral terminals of sensory nerves and inhibit neuronal excitability, resulting in analgesia. Compared to conventional exogenous agonists, endogenous opioids have a reduced potential of inducing receptor downregulation, tolerance or paradoxical excitatory effects due to unphysiologically high exogenous agonist concentrations at the receptor. Here we blocked the peptidase-induced degradation of opioids in peripheral injured tissue to locally augment this physiological system. In a model of inflammatory pain we found that the peptidases (aminopeptidase N and neutral endopeptidase) are present and metabolically active in macrophages, granulocytes, and sciatic nerves from inflamed tissue. Blocking both peptidases by their selective inhibitors prevented the degradation of endogenous opioid peptides and decreased inflammatory pain.  Thus, leukocytes and peripheral nerves are important sources of peptidases in inflamed tissue, and their blockade promotes peripheral opioid analgesia.

Group members involved: Anja Schreiter, Stephanie Miceli, Dominika Labuz

Collaborators: B. Roques (Université Paris Descartes), J. Sieper (Rheumatologie, Charité Campus Benjamin Franklin), M. Schmelz (Institut für Anästhesiologie, Fakultät für Klinische Medizin Mannheim, Universität Heidelberg)

Funding: DFG, MA 243/2-1 (H. Machelska); DFG, STE 477/9-1 (C. Stein)

Publications:

Machelska H, Stein C. Endogene Opioide: Ihre Wirkung kann man deutlich verstärken. AINS (Anästhesiologie, Intensivmedizin, Notfallmedizin, Schmerztherapie) 2013, 3:142-143

Schreiter A, Gore C, Labuz D, Fournie-Zaluski MC, Roques BP, Stein C, Machelska H.
Pain inhibition by blocking leukocytic and neuronal opioid peptidases in peripheral inflamed tissue..
FASEB J 2012; 26(12):5161-71.
Stein C, Küchler S.
Targeting inflammation and wound healing by opioids..
Trends Pharmacol Sci 2013; 34(6):303-312.

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Opioid actions on nociceptor function following nerve damage and inflammation

Halina Machelska, Christoph Stein

Peripheral nerve injuries or inflammation often trigger a hypersensitivity to mechanical stimulation. Behavioral studies demonstrated efficient and side effect-free analgesia mediated by opioid receptors on peripheral sensory neurons. However, mechanistic approaches addressing such opioid properties in chronic pain are lacking. We employ immunohistochemical and electrophysiological in vitro skin-nerve recordings in models of neuropathic and inflammatory pain. The goal is to examine how peripheral tissue damage affects properties of peripheral sensory fibers and how opioids modulate these properties. In neuropathic pain model we found that behaviorally manifested neuropathy-induced mechanosensitivity does not require a sensitized state of cutaneous nociceptors in damaged nerves. In contrast, in inflammation the nociceptors were sensitized to mechanical stimulation. In both models, μ-opioid receptor agonists (DAMGO or fentanyl) applied on the nociceptor cutaneous receptive fields significantly elevated the mechanical thresholds and diminished the mechanically evoked discharges of Aδ and C nociceptors in injured tissue. Prevention of action potential generation or propagation in nociceptors might represent a cellular mechanism underlying peripheral opioid-mediated alleviation of mechanical hypersensitivity in neuropathy and somatic inflammation.

Group members involved: Yvonne Schmidt, Rabih A. Moshourab, Dominika Labuz

Funding: DFG, KFO 100/2, Project 1, MA 2437/1-4 (H. Machelska)

Publications:

Moshourab R, Schmidt Y, Machelska H.
Skin-nerve preparation to assay the function of opioid receptors in peripheral endings of sensory neurons..
Methods Mol Biol. 2015; 1230 :215-28. .
Schmidt Y, Machelska H.
Immunohistochemical analysis of opioid receptors in peripheral tissues..
Methods Mol Biol. 2015; 1230:155-65.
Moshourab R, Stein C.
Fentanyl decreases discharges of C and A nociceptors to suprathreshold mechanical stimulation in chronic inflammation. .
J Neurophysiol 2012; 108(10):2827-36.
Schmidt Y, Gavériaux-Ruff C, Machelska H.
μ-Opioid receptor antibody reveals tissue-dependent specific staining and increased neuronal μ-receptor immunoreactivity at the injured nerve trunk in mice..
PLoS One. 2013; Nov 22;8(11):e79099.
Schmidt Y, Labuz D, Heppenstall PA, Machelska H.
Cutaneous nociceptors lack sensitisation, but reveal μ-opioid receptor-mediated reduction in excitability to mechanical stimulation in neuropathy..
Mol Pain 2012; Nov 2(8):81.

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Subcellular pathways of opioid peptide synthesis, processing and release from leukocytes

Christoph Stein

This project examines the posttranslational processing of pro-opiomelanocortin, proenkephalin and prodynorphin in immune cells under conditions of painful inflammation. Knock-out mice lacking processing enzymes are used. These mice show defective changes in beta-endorphin, Met-enkephalin and/or dynorphin processing in the pituitary gland and the brain. We examine mechanisms of opioid peptide processing and release in immune cells from these animals.

Collaborator: S.A. Mousa, Charité Campus Virchow-Klinikum

Funding: DFG, KFO 100/2, Teilprojekt: Opioid peptide expression, processing and release from immune cells (S.A. Mousa, C. Stein)

Publications:

Rittner HL, Labuz D, Schaefer M, Mousa SA, Schulz S, Schäfer M, Stein C, Brack A.
Pain control by CXCR2 ligands through Ca2+-regulated release of opioid peptides from polymorphonuclear cells.
FASEB J 2006; 20(14):2627-2629.
Mousa SA, Shakibaei M, Sitte N, Schäfer M, Stein C.
Subcellular pathways of beta-endorphin synthesis, processing and release from immunocytes in inflammatory pain.
Endocrinology 2004; 145:1331-1341.
Cabot PJ, Carter L, Schäfer M, Stein C.
Methionine-Enkephalin- and Dynorphin A-release from immune cells and control of inflammatory pain.
Pain 2001; 93(3):207-212.
Rittner HL, Labuz D, Richter JF, Brack A, Schäfer M, Stein C, Mousa SA.
CXCR1/2 ligands induce p38 MAPK-dependent translocation and release of opioid peptides from primary granules in vitro and in vivo.
Brain Behav Immun 2007; 21:1021-1032.

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Topical morphine for analgesia in patients with skin and mucosal lesions

Christoph Stein

Topically applied opioids have provided effective and safe analgesia when applied onto skin wounds. In animal models, opioids have been shown to enhance wound healing. This study has two arms: clinical and experimental. The clinical arm looks at the effect of morphine gel on analgesia when applied onto skin-graft wounds or oral mucosal lesions. We are also developing an animal model for assessing analgesia and wound healing in response to topical opioids. 

Group members involved: Ruth Zaslansky

Collaborators: M. Schäfer-Korting (Pharmacy, FU Berlin), A. Kopf (Anesthesiology, Charité Campus Benjamin Franklin), Y. Ullman & O. Fishelzon (Rambam Medical Center, Haifa, Israel), I. Kager and R. Likar (Landeskrankenhaus Klagenfurt, Austria), A.M. Schmidt-Westhausen (Oral Medicine, Charité Campus Benjamin Franklin)

Funding: International Anesthesia Research Society, Clinical Scholar Research Award 2006 (R. Zaslansky)

Publications:

Zaslansky R, Ben-Nun O, Ben-Shitrit S, Ullmann Y, Kopf A, Stein C.
A randomized controlled clinical pilot study assessing the analgesic effect of morphine applied topically onto split-thickness skin wounds. .
J Pharm Pharmacol 2014; Nov;66(11):1559–66.

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Differentiating peripherally from centrally mediated opioid analgesia

Christoph Stein, Halina Machelska

Peripherally mediated opioid analgesia may be achieved without adverse effects of centrally acting opioids. Efforts are made to design opioid agonists which do not pass the blood-brain barrier. Animal studies have shown that up to 50% of antinociceptive effects elicited by systemically applied conventional opioids can be attributed to peripheral opioid receptors. This project aims at defining the relative contribution of peripheral opioid receptors to morphine analgesia in clinical and experimental pain. In a clinical trial we found that following the selective blockade of peripheral opioid receptors by methylnaltrexone (MNX), a peripherally restricted opioid receptor antagonist, the patients' demand for morphine to achieve satisfactory postoperative pain relief was strongly increased (by about 40%). Thus, a significant proportion of analgesia produced by systemically administered morphine is mediated by peripheral opioid receptors in clinical postoperative pain. Drugs that selectively activate such receptors should have the potential to produce powerful clinical pain relief.

Group members involved: Dominika Labuz, Leonie Lang, Christina Jagla

Collaborators: M. Brandl, A. Okach, A. Timmermann, E. Nickel (Helios Kliniken Berlin), J. Eberitsch, K. Günther (Sana Kliniken Sommerfeld)

Funding: International Anesthesia Research Society, Clinical Scholar Research Award 2009 (L. Lang).

Publications:

Stein C, Jagla C
Methylnaltrexone and opioid analgesia..
Pain 2014; 155(12):2722-3.
Stein C, Lang LJ.
Peripheral mechanisms of opioid analgesia.
Curr Opin Pharmacol 2009; 9:3-8.
Labuz D, Mousa SA, Schäfer M, Stein C, Machelska H.
Relative contribution of peripheral versus central opioid receptors to antinociception.
Brain Res 2007; 1160:30-38.
Jagla CA, Martus P, Stein C.
Peripheral opioid receptor blockade increases postoperative morphine demands - a randomized, double-blind, placebo-controlled trial..
Pain. 214; Oct;155(10):2056-62.

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