DEBRA Members Weekend 2017

Transcription

1 DEBRA Members Weekend 2017 EB therapy research in Dundee: an update Knocking out the faulty gene & Skipping the faulty exon Peter van den Akker Premium sponsors:

2 EB therapy research in Dundee: an update Knocking out the faulty gene & Skipping the faulty exon Peter van den Akker DEBRA Clinical Research Fellow McLean-Hickerson lab, University of Dundee Clinical Geneticist UMC Groningen, the Netherlands

3 What am I going to tell you? Recap of my presentation of last year What does the skin look like? What is wrong in EB? EB therapy research in Dundee: where do we stand? Gene knock-out for EBS Exon-skipping for RDEB

4 The skin A wall - Protection Epidermis Dermis Hadrian s Wall

5 Epidermis Dermis Basement Membrane Zone (BMZ) Wednesday, 6 31 May

6 Epidermolysis bullosa simplex Basal skin cells Epidermis BMZ skin cells (keratinocytes) Basal cells Dermis Hadrian s Wall

7 Basal keratinocytes Keratin: support to cells BMZ Keratin 5&14 Basal skin cells (keratinocytes) Stretch Basal skin cells (keratinocytes) BMZ Keratin 5&14

8 Normal basal cells EBS basal cells Keratin 5&14

9 EBS Keratin cannot be made well BMZ Keratin 5&14 Basal skin cells (keratinocytes) Stretch BLISTER Basal skin cells (keratinocytes) BMZ Keratin 5&14

10 EBS Therapy Project in Dundee KNOCKING OUT THE FAULTY GENE

11 In a normal skin cell DNA RNA copy Protein Keratin 14

12 In an EBS skin cell DNA RNA copy Protein Keratin 14 Keratin protein Diseasecausing Mutation Mutation

13 gene knock-out DNA RNA copy Protein Keratin 14 G C Diseasecausing Mutation Mutation C Mutation-specific antisense oligonucleotides (ASOs) ( RNA scissors )

14 gene knock-out DNA RNA copy G C No match! Protein Keratin 14 Keratin protein C Diseasecausing Mutation Mutation Mutation-specific antisense oligonucleotides (ASOs) ( RNA scissors )

15 gene knock-out DNA RNA copy Protein Keratin 14 Keratin protein G C C Match! Mutation Mutation-specific antisense oligonucleotides (ASOs) ( RNA scissors )

16 gene knock-out DNA RNA copy Protein Keratin 14 Keratin protein G C C Mutation Disadvantage: mutations specific suitable only for a limited number of people with EBS

17 Benign DNA variations (SNP) DNA RNA copy Protein Keratin 14 Keratin protein C T Benign SNP SNP Everybody carries these benign variations (also people with EBS)

18 Targeting benign SNPs DNA RNA copy Protein Keratin 14 Keratin protein C SNP T T Match! Benign SNP SNP Same result as targeting a mutation

19 Targeting benign SNPs DNA RNA copy Protein Keratin 14 Keratin protein C T Benign SNP SNP Same result as targeting a mutation (but does not make a difference for the protein)

20 Idea: target the benign DNA variations (SNPs) that are linked to the mutations DNA RNA copy G C Protein Keratin 14 Keratin protein C SNP T T Match! Diseasecausing Mutation Benign SNP Mutation SNP

21 Idea: target the benign DNA variations (SNPs) that are linked to the mutations DNA RNA copy G C Protein Keratin 14 Keratin protein C T Diseasecausing Mutation Benign SNP Mutation SNP

22 Targeting many different mutations! DNA RNA copy Protein Keratin 14 Keratin protein A C G SNP T T Match! Other Mutation Benign SNP Other Mutation SNP

23 Targeting many different mutations! DNA RNA copy Protein Keratin 14 Keratin protein A C G T Other Mutation Benign SNP Other Mutation SNP Advantage: the strategy can be used to target many mutations and treat many patients

24 NOW WHERE DO WE STAND?

25 Treating cultured skin cells with ASOs ASOs Cultured skin cells

26 Treating skin with ASOs Epidermis ASOs Dermis

27 knockdown: summary Works in cultured skin cells Does not work as well in skin (skin explant system) as in cell culture We are trying to find out why this is, in order to improve the knockdown in our skin explant system and make it applicable for people with EBS

28 RDEB Therapy Project in Dundee SKIPPING THE FAULTY EXON

29 Dystrophic epidermolysis bullosa Anchoring fibrils: attach epidermis to dermis Epidermis Basal skin cells (keratinocytes) Dermis BMZ Keratin 5&14 Anchoring fibrils Composed of Type VII collagen

30 Dystrophic epidermolysis bullosa Anchoring fibrils are absent Stretch Epidermis Dermis BMZ Keratin 5&14 BLISTER Anchoring fibrils Composed of Type VII collagen Basal skin cells (keratinocytes)

31 In normal skin DNA COL7A1 RNA copy COL7A1 Protein Type VII collagen Normal skin Type VII collagen Nuclei

32 In RDEB skin DNA COL7A1 RNA copy COL7A1 Protein Type VII collagen Keratin protein RDEB Type VII collagen absent Nuclei

33 COL7A1 exon skipping DNA COL7A1 RNA copy COL7A1 Protein Type VII collagen

34 COL7A1 exon skipping DNA COL7A1 RNA copy COL7A1 Protein Type VII collagen Type VII collagen Nuclei

35 Normal skin RDEB

36 Goal of exon skipping Shorter but functional protein Normal skin RDEB

37 NOW WHERE DO WE STAND?

38 Exon skipping for COL7A1 Cultured RDEB cells make new type VII collagen 100% 0% 50% 30% 0% 10% Type VII collagen Nuclei 72 hours after transfection

39 Exon skipping for COL7A1 RDEB skin makes new type VII collagen Type VII collagen Nuclei

40 COL7A1 exon skipping: summary Works well for certain exons in cultured cells and skin grafts Does work less well for other exons We are trying to find out why this is We need to improve the exon skipping efficiency We are studying whether the skipped protein is truly functional

41 Acknowledgements McLean lab Irwin McLean Robyn Hickerson Michael Conneely Sylvain Roque Linda Campbell Stephanie MacCallum Yu-en Cheah Roberta Spilotri Aileen Sandilands Maurice van Steensel UMC Groningen, Dermatology & Genetics Marjon Pasmooij Jeroen Bremer Darryll Eichhorn Antoni Gostyński Miranda Nijenhuis Marcel Jonkman

42 Thank you for your attention Peter van den Akker DEBRA Clinical Research Fellow McLean lab, University of Dundee Clinical Geneticist UMC Groningen, the Netherlands

43 DEBRA Members Weekend 2017 EB therapy research in Dundee: an update Knocking out the faulty gene & Skipping the faulty exon Peter van den Akker Premium sponsors: