System-iPS:

An iPS cell-systems biology approach for modeling and discovery of therapeutic strategies of inherited basal ganglia disorders

Topic: To respond to the high attrition rate of current target-based drug discovery, an alternative systems-oriented human cell-based approach has been proposed, in which chemical compounds will be tested in a cell-relevant context at the early stage of the drug development pipeline. For neurological disorders, this is however hampered by the inability to sample live neuronal cells. The seminal discovery that adult somatic cells can be reprogrammed to a pluripotent state could help to circumvent these obstacles. The technology of induced pluripotent stem (iPS) cells might open up a novel paradigm in brain drug development, allowing the employment of live patient neurons for phenotype-based preclinical drug-screenings.
Aim: The project aims to generate patient-derived neuronal cell models of two genetic disorders affecting the basal ganglia and lacking effective treatments. Maternally inherited Leigh syndrome (MILS) is an infantile encephalopathy due to point mutations within the MT-ATP6 gene of the mitochondrial DNA (mtDNA). Huntington’s disease (HD) is a neurodegenerative disorder caused by the CAG triplet repeat expansion within the gene encoding the protein Huntingtin. Basal ganglia are highly dependent on mitochondrial-based energy production. Hence, the two diseases represent in a way two paradigmatic examples, one exhibiting a direct mitochondrial implication and one where mitochondrial dysfunctions are considered a secondary insult. Human basal ganglia neurons (GABAergic and dopaminergic) will be obtained from induced pluripotent stem (iPS) cells generated by reprogramming patient and control fibroblasts using footprint-free episomal plasmid-based techniques. The chance to identify a disease phenotype within the reprogramming-derived basal ganglia cells and to develop potential therapeutic strategies might be diminished when using only a conventional reductionist molecular biology approach. In this study, we therefore propose to broaden the levels of investigations by combining standard functional and biochemical assays with global OMICS-driven analyses (systematic transcriptomics, proteomics, and metabolomics) to unravel the disease mechanisms without an a priori knowledge. This would allow the generation of computational models for the two neuronal disease states and to in silico predict the targets of potential interventional strategies. The computational predictions will be validated in follow-up cellular experiments. Finally, based on the identified disease pathways, we will seek to establish scalable assays amenable to high-throughput and focused compound screenings. If successful, this iPS cell-driven systems biology approach may represent an innovative platform for drug discovery of complex genetic brain diseases.
 

 

Selected Publications


 

Human iPSC-Derived Neural Progenitors Are an Effective Drug Discovery Model for Neurological mtDNA Disorders.

Lorenz C, Lesimple P, Bukowiecki R, Zink A, Inak G, Mlody B, Singh M, Semtner M, Mah N, Auré K, Leong M, Zabiegalov O, Lyras EM, Pfiffer V, Fauler B, Eichhorst J, Wiesner B, Huebner N, Priller J, Mielke T, Meierhofer D, Izsvák Z, Meier JC, Bouillaud F, Adjaye J, Schuelke M, Wanker EE, Lombès A, Prigione A.

Cell Stem Cell. 2017 Jan 25. pii: S1934-5909(16)30469-6. doi: 10.1016/j.stem.2016.12.013.

PMID: 28132834

 

Energy metabolism in neuronal/glial induction and in iPSC models of brain disorders.

Mlody B, Lorenz C, Inak G, Prigione A.

Semin Cell Dev Biol. 2016 Apr;52:102-9. doi: 10.1016/j.semcdb.2016.02.018.

PMID: 26877213

 

Induced pluripotent stem cells (iPSCs) for modeling mitochondrial DNA disorders.

Prigione A.

Methods Mol Biol. 2015;1265:349-56. doi: 10.1007/978-1-4939-2288-8_24.

PMID: 25634286

 

Assessing the bioenergetic profile of human pluripotent stem cells.

Pfiffer V, Prigione A.

Methods Mol Biol. 2015;1264:279-88. doi: 10.1007/978-1-4939-2257-4_25.

PMID: 25631022

 

The return of metabolism: biochemistry and physiology of the pentose phosphate pathway.

Stincone A, Prigione A, Cramer T, Wamelink MM, Campbell K, Cheung E, Olin-Sandoval V, Grüning N, Krüger A, Tauqeer Alam M, Keller MA, Breitenbach M, Brindle KM, Rabinowitz JD, Ralser M.

Biol Rev Camb Philos Soc. 2014 Sep 22. doi: 10.1111/brv.12140. [Epub ahead of print]

PMID: 25243985

Mitochondrial Medicine

Drawing by Helena P.

Mitochondria are membrane-bound organelles acting as the power plants of the cell, because they generate most of the cell's supply of adenosine triphosphate (ATP). They have their own genome and also divide independently of the cell in which they reside. In addition to their bioenergetic role, mitochondria are involved in a number of cellular functions, including calcium and redox homeostasis signaling, cellular differentiation, apoptosis, as well as in the maintenance of cell cycle and growth.

Mitochondrial impairment has been implicated in several human diseases, such as Leigh syndrome, Parkinson’s disease, Huntington’s disease, Amyotrophic lateral sclerosis, and Autism. Mitochondrial disorders due to mutations in the mitochondrial DNA affect 1/5000 newborns. The nervous system is usually most affected, highlighting the dependence of neurons on mitochondrial functionality. No therapy or treatments currently exist, making mitochondrial diseases a significant burden for society.

iPSCs

iPSC-colony (red: NANOG)

Induced pluripotent stem cells (iPSCs) are generated by reprogramming adult somatic cells through forced expression of stem cell-specific transcription factors or related small molecules. iPSCs hold great promises in biomedical applications. Because they can propagate indefinitely, as well as give rise to every other cell type in the body, they may be employed for replacing defined tissues lost to damage or disease. Moreover, they can be used for model complex human disorders “in a dish”. Finally, iPSC derivatives may represent innovative cellular systems for the development of phenotype-driven drug discovery.