1 / 30

Alfredo Ribeiro-da-Silva, MD, PhD

Studies on Animal Models of Inflammatory Arthritis . Alfredo Ribeiro-da-Silva, MD, PhD. Alan Edwards Centre for Research on Pain Department of Pharmacology & Therapeutics Department of Anatomy & Cell Biology. Animal Models of Inflammatory Arthritis.

tatum
Download Presentation

Alfredo Ribeiro-da-Silva, MD, PhD

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Studies on Animal Models of Inflammatory Arthritis Alfredo Ribeiro-da-Silva, MD, PhD Alan Edwards Centre for Research on Pain Department of Pharmacology & Therapeutics Department of Anatomy & Cell Biology

  2. Animal Models of Inflammatory Arthritis • Models of rheumatoid arthritis (multiple joints affected bilaterally): • Complete Freund’s Adjuvant (CFA) in vein of base of tail or high dose subcutaneously • Immunization of animals against type II collagen • Models of localized disease: • Low dose of subcutaneous CFA in hindpaw • Monoarthritis models (knee, ankle, temporomandibular joints) – usually CFA injected in joint

  3. Localized vs. systemic models • Both have been used to test efficacy of drugs in pre-clinical trials • Localized models better if emphasis of our investigations is on pain mechanisms • We will focus on models of localized arthritis

  4. What we will talk about • Two models of localized arthritis: • Subcutaneous injection of small dose of complete Freund’s adjuvant (CFA) in plantar surface of rat hind paw arthritis localized to the paw • Intra-articular injection of CFA in ankle joint

  5. CFA model of arthritis localized to the hind paw of rat Complete Freund’s Adjuvant (CFA) Water-in-oil emulsion of antigen (heat-inactivated mycobacterium tuberculosis or butyricum ) Edema and swelling of joints No contralateral changes

  6. Pathological changes • Early changes: • In soft tissues: Infiltration of inflammatory cells, plasma extravasation with oedema • In joint: Synovitis, with invasion of inflammatory cells, proliferation of vessels • Late changes (starting at 2 weeks): • Cartilage and bone destruction • Changes in innervation (significant ONLY when there is bone and joint destruction)

  7. Pathology in the joint Inflamed and thickened synovium Reduced SF viscosity Destroyed cartilage Bony outgrowths Destroyed meniscus Thickened capsule Knee joint as an example

  8. Changes in joints and bone start at 2 weeks post-CFA From Almarestani et al., Arthritis Rheum. 63 (6):1573-1581, 2011.

  9. Assessment of joints by X-rays (micro-CT) From Almarestani et al., Arthritis Rheum. 63 (6):1573-1581, 2011.

  10. Joint from control animal Histology of joint 2 weeks after intraplantar CFA • Reduction of articular space • Thickening of synovium and capsule • Erosion of cartilage 200 µm Joint from CFA-treated animal 200 µm

  11. Intraplantar CFA induces changes in innervation of thick skin adjacent to joints Sympathetic fibres Peptidergic fibres Almarestani, Longo and Ribeiro-da-Silva. Molecular Pain 4:56, 2008. - Sensory - Sympathetic

  12. Intraplantar CFA induces changes in innervation of skin adjacent to joint (2) • Sensory nociceptive fibres increase in density after 2 weeks • Sympathetic fibres invade the upper dermis and wrap around sensory nociceptive fibres • Possible contribution to pain

  13. CFA-induced monoarthritis of the ankle joint Complete Freund’s Adjuvant (CFA) Heat-killed Mycobacterium butyricum ** Intra-articular injections of CFA into the tibio-tarsal joint Sham CFA 4 weeks

  14. Pain-related behaviour changesin ankle joint CFA monoarthritis • Animals develop persistent mechanical allodynia, heat hyperalgesia and cold allodynia starting shortly after CFA injection From Longo, Osikowicz, and Ribeiro-da-Silva,J.Neurosci. 2013.(In Press)

  15. In monoarthritis, only sympathetic fibres sprout in skin over joint Sham Sham 2 weeks Sympathetic Sensory 4 weeks 3 weeks 4 weeks From Longo, Osikowicz, and Ribeiro-da-Silva,J.Neurosci. 2013.(In Press)

  16. In the synovial membrane of ankle joint, both nociceptive peptidergic and sympathetic fibres sprout at 4 weeks post-intra-articular CFA From Longo, Osikowicz, and Ribeiro-da-Silva,J.Neurosci. 2013.(In Press)

  17. Does this sympathetic sprouting contribute to the pain? Mechanical • Blocking function of sympathetic fibres with guanethidine at 4 weeks post-CFA improves pain-related behaviour • At 2 weeks, when there is no fibre sprouting, it has no effect Cold Heat From Longo, Osikowicz, and Ribeiro-da-Silva, J.Neurosci. 2013.(In Press)

  18. Trophic factor changes • The mature form of NGF (mNGF), but not the precursor proNGFwas elevated in skin over joint • Elevated levels of NGF likely contribute to sprouting and pain From Longo, Osikowicz, and Ribeiro-da-Silva, J.Neurosci. 2013.(In Press)

  19. Changes in Spinal Cord

  20. Small diameter primary afferents transmitting pain-related information S. P. Hunt and P. W. Mantyh. The molecular dynamics of pain control.Nat.Rev.Neurosci. 2 (2):83-91, 2001.

  21. CGRP/IB4 mouse ____ Non-peptidergic ____ Peptidergic Peptidergic and non-peptidergic nociceptive fibres differ in termination in spinal cord

  22. Changes in spinal dorsal horn in inflammation and arthritis • At first, decreases in substance P and CGRP immunoreactivities (increased release), followed by increases • Modest increase in messages for enkephalin, galanin and substance P in interneurons • Increases in GABA and GAD • Substantial increases in immunoreactivity for the substance P receptor, the NK1 receptor.

  23. Number of Substance P-labelled varicosities increases in CFA ankle mono-arthritis Sharif Naeini et al., Eur.J.Neurosci. 22 (8):2005-2015, 2005.

  24. Changes in NK-1 receptor in CFA mono-arthritis Sharif Naeini et al., Eur.J.Neurosci. 22 (8):2005-2015, 2005.

  25. EM demonstration of receptor internalization but only with joint mobilization Sharif Naeini et al., Eur.J.Neurosci. 22 (8):2005-2015, 2005.

  26. Changes in phenotype in dorsal horn lamina I neurons • Multipolar(HPC) Polymodal nociceptive neurons • Fusiform(NS) Nociceptive-specific neurons • Pyramidal (COLD) Innocuous thermoreceptive

  27. Pyramidal neurons start to express NK-1 receptors at 15 days post-CFA Almarestani et al., J.Comp.Neurol. 514 (3):284-295, 2009.

  28. Pyramidal neurons gain a de novo innervation by substance P at 15 days post-CFA • Pyramidal neurons normally are scarcely innervated by substance P afferents • Starting at 2 weeks post-CFA, pyramidal neurons are abundantly innervated by substance P Almarestani et al., J.Comp.Neurol. 514 (3):284-295, 2009.

  29. Conclusions • Animal models of inflammatory arthritis reveal changes both in the periphery (skin and joints) and spinal cord that can give some clues regarding mechanisms of pain at several stages of the development of arthritis • It is important to point out that changes such as • sympathetic sprouting in joint and adjacent skin • de novo expression of substance P receptors in pyramidal neurons in spinal cord appear ONLY when there is joint and bone damage • These late changes also occur in neuropathic pain models, giving some support to concept that the two pathologies have some similarities

  30. Acknowledgements • Lina Almarestani • Geraldine Longo • Maria Osikowicz • Gary J. Bennett • Mary-Ann Fitzcharles • Reza Sharif • Catherine Cahill • James L. Henry • CIHR • Louise and Alan Edwards Foundation • MITACS Accelerate in partnership with Pfizer Canada

More Related