1 / 53

Jürgen Kraus

Tolerance to Opioids and Cannabinoids: a Novel Role for MicroRNA. Jürgen Kraus. Summer School Bologna 27.6.2012. Tolerance. Pharmacology: Decreased effectiveness of a drug upon repeated application >>> higher doses. Tolerance. Tolerance.

Download Presentation

Jürgen Kraus

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. Tolerance to Opioids and Cannabinoids: a Novel Role for MicroRNA Jürgen Kraus Summer School Bologna 27.6.2012

  2. Tolerance Pharmacology: Decreased effectiveness of a drug upon repeated application >>> higher doses

  3. Tolerance

  4. Tolerance Pharmacology: Decreased effectiveness of a drug upon repeated application >>> higher doses Decreased amount of functional membrane-bound receptors for this drug

  5. Tolerance Decreased amount of membrane-bound receptors 1. Phosphorylation/internalization of receptors resulting in decreased effectiveness 2. Downregulation of receptors resulting in deceased amounts

  6. P P Ligand-Induced Phosphorylation and Internalization Localization in Cellmembrane Ligand-Induced Phosphorylation Internalization Recycling Degradation

  7. P P Localization and Ligand-Induced Regulation of µ-Opioid Receptors in Jurkat T Cells

  8. Tolerance - „internalizing drugs“ (e. g. fentanly or methadone) cause the same tolerance as „non-internalizing drugs“ (e. g. morphine) - tolerance develops within a range of minimum 12 hours up to several days

  9. Tolerance Decreased amount of membrane-bound receptors 1. Phosphorylation/internalization of receptors resulting in decreased effectiveness 2. Downregulation of receptors resulting in deceased amounts

  10. DNA > RNA > Protein

  11. MOR mRNA is NOT Downregulated by Opioids

  12. microRNA DNA > RNA > Protein

  13. MOR mRNA is NOT Downregulated by Opioids

  14. Tolerance to Opioids and Cannabinoids Involves MicroRNA

  15. ? Does µRNA regulate MOR and CB1

  16. µ Opioid Receptor Cannabinoid Receptor 1 Structure Effects Expression Cross-Tolerance

  17. Functional Analysis of MOR and CB1 - Stimulation of cells with MOR and CB1 ligands results in phosphorylation of the mitogen activated protein kinase p42/44 - Stimulation of cells with MOR and CB1 ligands results in a decrease in intracellular cAMP due to inhibition of adenylyl cyclase

  18. µRNA MOR CB1 µRNA miR-98, let-7a, let-7d, miR-23b MOR CB1

  19. Overexpression of µRNA Inhibits Ligand-Induced Formation of Phospho-MAPK µRNA MOR CB1 SH SY5Y

  20. µRNA MOR CB1 Overexpression of µRNA Inhibits Ligand-Induced Inhibition of cAMP Formation

  21. µRNA MOR CB1 Overexpression of µRNA Inhibits Ligand-Induced Inhibition of cAMP Formation

  22. Summary miR-98, let-7a, let-7d MOR

  23. µRNA MOR CB1 Overexpression of µRNA Inhibits Ligand-Induced Inhibition of cAMP Formation

  24. µRNA MOR CB1 Overexpression of µRNA Inhibits Ligand-Induced Inhibition of cAMP Formation

  25. Summary miR-98, let-7a, let-7d, miR-23b MOR CB1

  26. Summary let-7d MOR CB1

  27. And Now for Something (Completely) Different ...

  28. And Now for Something (Completely) Different ... - Tolerance - Crosstolerance (some colums are missing, but you will see them later)

  29. And Now for Something (Completely) Different ... - Tolerance - Crosstolerance

  30. Upregulation of µRNA in Response to Opioids and Cannabinoids Must be shown by µRNA Sequencing

  31. ? How can we demonstrate functional induction of let7-d by opioids and cannabinoids

  32. Upregulation of µRNA in Response to Opioids and Cannabinoids

  33. Upregulation of µRNA in Response to Opioids and Cannabinoids

  34. ? What about tolerance, when we inhibit let7-d µRNA

  35. Human let-7d Inhibits Human and Rat MOR Expression

  36. MAEA morphine let-7d MOR CB1 MAEA morphine let-7d MOR CB1

  37. MAEA morphine let-7d MOR CB1 µRNA Might is Likely to Produce Tolerance to Opioids and Cannabinoids

  38. µRNA Might is Likely to Produce Tolerance to Opioids and Cannabinoids

  39. So far, so good, but tolerance is not a cellular event (even when many people say so)

  40. Can Antagomirs Against let-7d Inhibit Tolerance to Opioids in Mice? Antagomirs = Antagonists to µRNAs RNA oligonucleotides protected chemically against rapid degradation Are linked to cholesterol to get into the cells Designed for use in animals (and humans!) Were applied icv in our experiments 4 times 8µg (in 4 µl) were injected, 3 days before testing analgesia

  41. Antagomirs against let-7d Inhibit Tolerance to Opioids in Mice

  42. Summary miR-98, let-7a, let-7d, miR-23b MOR CB1

  43. Summary let-7d MOR CB1

  44. Summary MAEA morphine let-7d MOR CB1

  45. Summary MAEA morphine let-7d MOR CB1

  46. Summary MAEA morphine let-7d MOR CB1

More Related