Hutchinson Gilford Progeria Syndrome (HGPS) is a rare genetic disorder which is characterized by mutations in lamin A, resulting in premature aging in children, severe cardiovascular complications and early death. A full understanding of HGPS is not yet available and hence therapeutic strategies are far from being optimized. However, it is well established that HGPS lamin A mutations cause nuclear fragility, a pivotal component of the disease phenotype. This aspect in turn points to the involvement in HGPS of the endosomal sorting complex required for transport (ESCRT), a machinery controlling nuclear integrity. Indeed, ESCRT members CHMP2 and CHMP7 have been associated with nuclear envelope sealing and linked with HGPS. We have experimental evidence of a new putative ESCRT associated factor named AKTIP, highly similar to ESCRT protein TSG101. AKTIP is enriched at the nuclear envelope and its localization is controlled by lamin A and affected by progeroid lamin A mutations.
The objectives of this proposal are: i) Deepen the understanding of HGPS pathomechanisms and ii) Explore new paths for therapy of HGPS, by studying the ESCRT complex mechanistically, genetically and as a therapeutic tool. To achieve my goals I will: i) Characterize by super resolution microscopy and biochemistry nuclear envelope and ESCRTs in wild type and progeroid conditions and ii) Produce lentivectors encoding ESCRT components as gene therapy approach to rescue HGPS nuclear defects.
In summary, through the outlined research I expect: i) To clarify mechanical aspects of HGPS; ii) To produce a gene therapy tool for progeroid nuclei repair; iii) Obtain new insights on ESCRTs at the nuclear envelope.
Nuclear envelope resealing postmitotically and in interphase are central elements in the biology of the cell to maintain the nucleus-cytoplasm compartimentalization. Improper nuclear envelope organization can lead to chromatin dysfunction, altered replication, unscheduled transcription and cell division defects, which in turn impinge on stem cell and tissue homeostasis, converging, as in HGPS, into progeroid disease. ESCRT proteins function at the nuclear envelope as pivotal elements for nuclear envelope reorganization in telophase, but also, in interphase, for its repair. Recent developments in high resolution imaging, reverse genetics and biochemistry have opened the road to new in depth molecular mechanistic understanding of dynamic biological processes. Here I plan to use these approaches to contribute to complete the picture of known and new (AKTIP) ESCRT factors at the nuclear envelope. In addition to this, and, importantly, I plan to fit these data into the interpretation and treatment of progeroid disease. This approach has not yet been investigated for nuclear phenotype repair and progeroid treatment and I are confident that it represents a promising path.
Refs of the entire project
Amendola M et al 2005. Coordinate dual-gene transgenesis by lentiviral vectors carrying synthetic bidirectional promoters. Nat Biotechn 23:108
Balmus G et al 2018. Targeting of NAT10 enhances healthspan in a mouse model of human accelerated aging syndrome. Nat Commun 9:1700
Burla R et al 2015. AKTIP/Ft1, a New Shelterin-Interacting Factor Required for Telomere Maintenance. PLoS Genet 11:e1005167
Burla R et al 2016a. The telomeric protein AKTIP interacts with A and B-type lamins and is involved in regulation of cellular senescence. Open Biol 6
Burla R et al 2016b. Mammalian telomeres and their partnership with lamins. Nucleus 7:187
Cenni V et al 2011. Autophagic degradation of farnesylated prelamin A as a therapeutic approach to lamin-linked progeria. Eur J Histoch 55:e36
De Sandre-Giovannoli A et al 2003. Lamin a truncation in Hutchinson-Gilford progeria. Science 300:2055
Denais CM et al 2016. Nuclear envelope rupture and repair during cancer cell migration. Science 352:353
Gonzalo S et al 2017. Hutchinson-Gilford Progeria Syndrome: A premature aging disease caused by LMNA gene mutations. Ageing Res Rev 33:18
Gordon LB et al 2016. Clinical Trial of the Protein Farnesylation Inhibitors Lonafarnib, Pravastatin, and Zoledronic Acid in Children With Hutchinson-Gilford Progeria Syndrome. Circulation 134:114
Harhouri K et al 2016. Antisense-Based Progerin Downregulation in HGPS-Like Patients' Cells. Cells 5
Hennekam RC. 2006. Hutchinson-Gilford progeria syndrome: review of the phenotype. Am J Med Genet A 140:2603
La Torre M et al 2018. Mice with reduced expression of the telomere-associated protein Ft1 develop p53-sensitive progeroid traits. Aging Cell:e12730
Larrieu D et al 2014. Chemical inhibition of NAT10 corrects defects of laminopathic cells. Science 344:527
Liu G et al 2011. Recapitulation of premature aging with iPSCs from Hutchinson-Gilford progeria syndrome. Nature 472:221
McDonald B, Martin-Serrano J. 2008. Regulation of Tsg101 expression by the steadiness box: a role of Tsg101-associated ligase. Mol Biol Cell 19:754-763
Morita E et al 2007. Human ESCRT and ALIX proteins interact with proteins of the midbody and function in cytokinesis. EMBO J 26:4215-4227
Olmos Y, Carlton JG. 2016. The ESCRT machinery: new roles at new holes. Curr Opin Cell Biol 38:1-11
Olmos Y et al 2015. ESCRT-III controls nuclear envelope reformation. Nature 522:236-239
Osorio FG et al 2011. Splicing-directed therapy in a new mouse model of human accelerated aging. Sci Transl Med 3:106ra107
Pellegrini et al 2015. Alltrans retinoic acid and rapamycin normalize Hutchinson Gilford progeria fibroblast phenotype. Oncotarget 6:29914-29928
Piersanti S et al 2010. Transfer, analysis, and reversion of the fibrous dysplasia cellular phenotype in human skeletal progenitors. J Bone Miner Res 25:1103-1116
Raab M et al 2016. ESCRT III repairs nuclear envelope ruptures during cell migration to limitDNA damage and cell death. Science 352:359-362
Robijns J et al 2016. In silico synchronization reveals regulators of nuclear ruptures in lamin A/C deficient model cells. Sci Rep 6:30325
Rodier F, Campisi J. 2011. Four faces of cellular senescence. J Cell Biol 192:547-556
Saggio I et al 2014. Constitutive expression of Gsalpha (R201C) in mice produces a heritable, direct replica of human fibrous dysplasia bone pathology and demonstrates its natural history. J Bone Miner Res 29:2357-2368
Schmidt O, Teis D. 2012. The ESCRT machinery. Curr Biol 22:R116-120
Verstraeten VL et al 2008. Increased mechanosensitivity and nuclear stiffness in Hutchinson-Gilford progeria cells: effects of farnesyltransferase inhibitors. Aging Cell 7:383-393
Vietri M et al 2015. Spastin and ESCRT-III coordinate mitotic spindle disassembly and nuclear envelope sealing. Nature 522:231-235