Presentation on theme: "Nuclear lamins and laminopathies"— Presentation transcript:
1 Nuclear lamins and laminopathies - What is lamin A?- LAMINOPATHIESDrug discovery platform:Lamin A and agingPrelamin A processing and drugs acting on itStructure of the platformDIATHEVA’s antibodies unique performanceVersion
2 INDEXWHAT IS LAMIN A?Lamin A is the major component of the nuclear lamina and supports many nuclear functions. Alterations in lamin A gene, protein or maturation pathway have been associated with:Laminopathies, a group of inherited disorders in which Lamin A gene is mutated;Tumours, because aberrant expression of A-type lamins is a marker of differentiated tumour cells and seems to be a marker of good or poor patient survival;Aging, since it has been hypothesized a shared mechanism between pathological and physiological process;Anti-retroviral therapy, involving the use of protease inhibitors (PIs). Some HIV-PIs lead to the onset of a secondary laminopathy through the inhibition of ZMPSTE24, the enzyme responsible for prelamin A maturation.
3 Accumulation of Prelamin A INDEXLAMINOPATHIESEmery-Dreifuss muscular dystrophyLimb-girdle muscular dystrophyFamilian cardiomyopathy with conduction system diseaseCharcot-Marie-Tooth peripheral neuropathyDunningan-type familian partial lipodystrophyMandibuloacral dysplasiaRestrictive DermopathyHutchinson-Gilford progeria syndromeAtypical Werner’s syndromeAtypical progeroid syndrome(Progeroid syndromes)Accumulation of Prelamin AWorman H.J. Et al., (2010), CSH PerspectivesAndrés V. et al., (2009), The Journal of Cell Biology
4 LAMIN A AND AGING Drug discovery platform INDEXDrug discovery platformLAMIN A AND AGINGAbnormal RNA splicing occurring in HGPS cells takes place at very low levels in normal cells. Accelerated aging in HGPS might reflect an exaggerated lamin A-dependent mechanism, which normally contributes to physiological aging1-3.EXO 11EXO 12C>TLMNA mRNAConstitutive use of the activated cryptic splice siteHGPS patientsSporadic use of the activated cryptic splice siteHealty old individualsHigh levels of toxic truncated lamin ALow levels of toxic truncated lamin A≈10 YEARS≈70 YEARS50 aa deletionCSIMFarnesylPROGERINAlteration of nuclear lamina structureDisorganization of heterochromatinHistone modificationsAccumulation of unrepaired DNA damage1Coutinho H.D. et al., (2009) Immunity & Ageing2McClintock D. et al., (2007) Plos One3Navarro C.L. at al., (2006) Human Molecular Genetics
5 Drug discovery platform INDEXDrug discovery platformA new platform in drug discovery for:Laminopathies and Progeroid SyndromesAgingAnti-retroviral therapyThe platform includes:Polyclonal antibodiesRecombinant proteinsPCR kits for direct sequencing of the involved genesPrelamin A processing Cell-Free System Immunoassay
6 Cleavage by endoprotease (Zmpste24 or RCE1) INDEXDrug discovery platformCAAX motifRSY-LLGNSSPRTQSPQNCSIMCOOHSHADrugs acting on prelamin A processingPRELAMIN AFTISTATINSBISPHOSPHONATESFarnesylationFarnesyltransferase Inhibitors (FTI) treatment causes reversion of the nuclear blebbing and improving of the nuclear shape in HGPS fibroblasts1.Several clinical trials for laminopathies are currently ongoing evaluating the effects of FTI, statins and bisphosphonates.BRSY-LLGNSSPRTQSPQNCSIMCOOHSCleavage by endoprotease (Zmpste24 or RCE1)SIMCOOHSCRSY-LLGNSSPRTQSPQNCMethylationHIV Protease Inhibitors (HIV-PIs) Lopinavir, Ritonavir and Tipranavir interfere with prelamin A processing by blocking ZMPSTE24others HIV-PIs show no or little effect on the enzyme activity (Atazanavir, Amprenavir. Darunavir)2.SDRSY-LLGNSSPRTQSPQNCCOCH3HIV-I PIscleavage by Zmpste24LLGNSSPRTQSPQNCSCOCH3ERSY-COOHMATURE LAMIN A1Yang S. H. et al., (2010) J Lipid Res.2Hudon S.E. at al., (2008) Biochem Biophys Res Commun.
7 anti-prelamin A antibody anti-cleaved-farnesylated prelamin A antibody INDEXDrug discovery platformHuman fibroblasts accumulating non-farnesylated prelamin AHuman fibroblasts accumulating farnesylated prelamin A (or progerin)anti-prelamin A antibodyanti-cleaved-farnesylated prelamin A antibodyDIATHEVA’s antibodies can be used to discriminate which prelamin A forms are accumulated in laminopathic or drug-treated cell samples and to test the efficacy of any type of drug acting on the prelamin A maturation pathwayDominici S. et al., (2009), European Journal of Histochemistry