1. Nuclear lamins and laminopathies
- What is lamin A?
- LAMINOPATHIES
Drug discovery platform:
Lamin A and aging
Prelamin A processing and drugs acting on it
Structure of the platform
DIATHEVA’s antibodies unique performance
Version

2. INDEX
WHAT 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
INDEX
LAMINOPATHIES
Emery-Dreifuss muscular dystrophy
Limb-girdle muscular dystrophy
Familian cardiomyopathy with conduction system disease
Charcot-Marie-Tooth peripheral neuropathy
Dunningan-type familian partial lipodystrophy
Mandibuloacral dysplasia
Restrictive Dermopathy
Hutchinson-Gilford progeria syndrome
Atypical Werner’s syndrome
Atypical progeroid syndrome
(Progeroid syndromes)
Accumulation of Prelamin A
Worman H.J. Et al., (2010), CSH Perspectives
Andrés V. et al., (2009), The Journal of Cell Biology

4. LAMIN A AND AGING Drug discovery platform
INDEX
Drug discovery platform
LAMIN A AND AGING
Abnormal 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 11
EXO 12
C>T
LMNA mRNA
Constitutive use of the activated cryptic splice site
HGPS patients
Sporadic use of the activated cryptic splice site
Healty old individuals
High levels of toxic truncated lamin A
Low levels of toxic truncated lamin A
≈10 YEARS
≈70 YEARS
50 aa deletion
CSIM
Farnesyl
PROGERIN
Alteration of nuclear lamina structure
Disorganization of heterochromatin
Histone modifications
Accumulation of unrepaired DNA damage
1Coutinho H.D. et al., (2009) Immunity & Ageing
2McClintock D. et al., (2007) Plos One
3Navarro C.L. at al., (2006) Human Molecular Genetics

5. Drug discovery platform
INDEX
Drug discovery platform
A new platform in drug discovery for:
Laminopathies and Progeroid Syndromes
Aging
Anti-retroviral therapy
The platform includes:
Polyclonal antibodies
Recombinant proteins
PCR kits for direct sequencing of the involved genes
Prelamin A processing Cell-Free System Immunoassay

6. Cleavage by endoprotease (Zmpste24 or RCE1)
INDEX
Drug discovery platform
CAAX motif
RSY-LLGNSSPRTQSPQNCSIM
COOH SH A
Drugs acting on prelamin A processing
PRELAMIN A
FTI
STATINS
BISPHOSPHONATES
Farnesylation
Farnesyltransferase 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. B
RSY-LLGNSSPRTQSPQNCSIM
COOH S
Cleavage by endoprotease (Zmpste24 or RCE1)
SIM
COOH S C
RSY-LLGNSSPRTQSPQNC
Methylation
HIV Protease Inhibitors (HIV-PIs) Lopinavir, Ritonavir and Tipranavir interfere with prelamin A processing by blocking ZMPSTE24
others HIV-PIs show no or little effect on the enzyme activity (Atazanavir, Amprenavir. Darunavir)2. S D
RSY-LLGNSSPRTQSPQNC
COCH3
HIV-I PIs
cleavage by Zmpste24
LLGNSSPRTQSPQNC S
COCH3 E
RSY-COOH
MATURE LAMIN A
1Yang 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
INDEX
Drug discovery platform
Human fibroblasts accumulating non-farnesylated prelamin A
Human fibroblasts accumulating farnesylated prelamin A (or progerin)
anti-prelamin A antibody
anti-cleaved-farnesylated prelamin A antibody
DIATHEVA’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 pathway
Dominici S. et al., (2009), European Journal of Histochemistry