Research Maria-Luise Petrovic-Erfurth

Abstract

Charcot-Marie-Tooth neuropathies (CMT) represent the most common neuromuscular disorder. CMT is currently incurable, while the symptomatic treatment cannot alleviate the main symptoms of patients. Therefore, a better understanding of the disease pathomechanisms and generation of efficient drugs are urgently needed. We reported that Dominant Intermediate CMT type C (DI-CMTC) is caused by mutations in the tyrosyl-tRNA synthetase (YARS)2. To dissect the molecular mechanisms underlying YARS-related CMT, my host lab generated and characterized Drosophila models for DI-CMTC, which reproduced the cellular and molecular hallmarks of disease pathology in humans.. In frame of this project, we will characterize the signaling state of CMT-(SHSY-5Y and iPSC) neurons not only via classical morphological and functional parameters but we also aim to establish their signaling status in a spatially resolved manner. Specifically, I envisage to evaluate the subcellular protein and mRNA localization of YARS and putative YARS interactors with Digital Spatial Profiling (DSP, Nanostring Technologies) of CMT-neurons. Given that I am interested in both the phosphorylation- and mRNA-expression signature of CMT-MNs, this technique seems to be ideally suited for my purpose.

Researcher(s)

• Promoter: Jordanova Albena
• Co-promoter: Petrovic-Erfurth Maria-Luise

Research team(s)

• VIB CMN - Molecular Neurogenomics

Project type(s)

• Research Project

Abstract

Aminoacyl-tRNA synthetases (ARS) are the largest family of proteins implicated in Charcot- MarieTooth disease (CMT), the most common inherited peripheral neuropathy. Patients experience walking difficulties and sensory loss leaving them disabled. CMT is a life-long and incurable disease. ARS are ubiquitous essential enzymes normally required for protein biosynthesis. However, in neurodegeneration a distinct unknown cellular mechanism is responsible. We have established Drosophila models to study CMT caused by mutations in tyrosyl- and glycyl tRNA synthetases (YARS and GARS). Like patients, CMT-flies display hallmark symptoms of the neuropathy, such as progressive motor impairment. Preliminary data utilizing these flies suggests that an imbalance in phosphor-signaling might cause CMT. Specifically, I identified in frame of my FWO-funded project a pathway regulated by WNK kinases, capable of alleviating CMT symptoms. Here, I propose to translate these exciting findings from flies to vertebrates: I am currently establishing iPSC derived motor neurons (MNs) from YARS-CMT patients. In frame of this project I am proposing to correct the YARS- CMT point-mutation via CRISPR-CAS9 technology. Then I will compare the patient derived and the corrected cells in a standard manner. In addition, I will also assess their differential phosphorylation profile. In the future, I will integrate and match these phosphor-signatures with the genetic and proteomic findings of my previous research. This will enable the bioinformatic reconstruction of the cellular mechanisms affected by CMT to pinpoint the best molecular targets for future therapies.

Researcher(s)

• Promoter: Petrovic-Erfurth Maria-Luise

Research team(s)

• VIB CMN - Molecular Neurogenomics

Project type(s)

• Research Project

Abstract

Charcot-Marie-Tooth neuropathies (CMT) represent the most common neuromuscular disorder. CMT is currently incurable, while the symptomatic treatment cannot alleviate the main symptoms of patients. Therefore, a better understanding of the disease pathomechanisms and generation of efficient drugs are urgently needed. We reported that Dominant Intermediate CMT type C (DI-CMTC) is caused by mutations in the tyrosyl-tRNA synthetase (YARS)2. To dissect the molecular mechanisms underlying YARS-related CMT, my host lab generated and characterized Drosophila models for DI-CMTC, which reproduced the cellular and molecular hallmarks of disease pathology in humans.. In frame of this project, we will characterize the signaling state of CMT-(SHSY-5Y and iPSC) neurons not only via classical morphological and functional parameters but we also aim to establish their signaling status in a spatially resolved manner. Specifically, I envisage to evaluate the subcellular protein and mRNA localization of YARS and putative YARS interactors with Digital Spatial Profiling (DSP, Nanostring Technologies) of CMT-neurons. Given that I am interested in both the phosphorylation- and mRNA-expression signature of CMT-MNs, this technique seems to be ideally suited for my purpose.

Researcher(s)

• Promoter: Jordanova Albena
• Co-promoter: Petrovic-Erfurth Maria-Luise

Research team(s)

• VIB CMN - Molecular Neurogenomics

Project type(s)

• Research Project

Abstract

Aminoacyl-tRNA synthetases (ARS) are the largest family of proteins implicated in Charcot-Marie- Tooth disease (CMT), the most common inherited peripheral neuropathy. CMT is a life-long and incurable disease. ARS are ubiquitous essential enzymes normally required for protein biosynthesis. However, in neurodegeneration, a distinct unknown cellular mechanism triggered by the CMT mutations in ARS is at play. We have established Drosophila and cellular CMT models and studied the pathways altered in presence of mutations in tyrosyl-tRNA synthetase (YARS). By utilizing these models in a complimentary manner, we have solid evidence that dysregulated phosphor-signaling might underlie ARS-related CMT. Here, I propose to translate these exciting findings from flies and neuroblastoma cells to human motorneurons (MNs), the primary cell type affected by the CMT-ARS mutations. I will establish iPSC derived MNs from YARS-CMT patients and will assess spatially and quantitatively their phosphorylation profile. Then I will attempt to pharmacologically revert the disease profile signatures to healthy state. Thereby, I will not only provide a proof of concept for future CMT therapies, but will also characterize a novel role of the YARS protein in phosphor-signaling.

Researcher(s)

• Promoter: Jordanova Albena
• Fellow: Petrovic-Erfurth Maria-Luise

Research team(s)

• VIB CMN - Molecular Neurogenomics

Project type(s)

• Research Project

Abstract

Peripheral neuropathies (PNs) affect 3-4% of the old (>55 years). Often, the disease manifests as result of stress (e.g. diabetes or chemotherapy). There are also hereditary forms of neuropathies. Patients experience altered sensations and pain in hands/feet as well as orthopedic and coordination problems. Hereditary PNs start in the first two decades of life. Among them CharcotMarie Tooth disease (CMT) is the most frequent subtype which is currently, like all other PNs, incurable. Patients are only treated to relieve symptoms, leaving them ultimately severely disabled. The development of a therapy, requires a better understanding of the molecular mechanisms underlying CMT. I propose to test the role of a regulatory cellular signaling mechanisms (phosphorylation) in the CMT-etiology. As an expert in the biology of neuropathy and phosphorylation, I will perform my work in a lab specialized in CMT-genetics. My idea that phosphorylation might be critical for CMT results from a genetic screen utilizing the CMT-fly model established by my host lab. To verify these results, I have engineered human CMT-cell lines. By analyzing their signaling state via (phosphor)- proteomics, I will pinpoint the best molecular targets for future therapies. The advantage of focusing on phosphorylation is the detailed knowledge of phosphor-pathways and their modulators. I will genetically test putative drug-targets in vivo laying the foundation for the first therapy specific for CMT.

Researcher(s)

• Promoter: Petrovic-Erfurth Maria-Luise

Research team(s)

• VIB CMN - Molecular Neurogenomics

Project type(s)

• Research Project

Abstract

Charcot-Marie-Tooth disease is an incurable hereditary neurodegenerative disorder characterized by severe and progressive sensori-motor deficits. More than 80 genes have been described to cause this pathology and among them there are 6 aminoacyl tRNA-synthetases (ARS) rendering them a prominent CMT-causing genes family. Interestingly, all the mutations lead to an axonal phenotype. ARS are ubiquitously expressed enzyme involved in the initial step of protein biosynthesis, therefore they are indispensable for cell viability. So far, it still remains mysterious how molecular defects in these proteins could cause neurodegeneration with the same spectrum of neuropathic symptoms. My project is to investigate if there is an existence of a common toxic pathway in mutant ARS associated with CMT. I will employ a unique combination of experimental approaches (cell biology, proteomics, microscopy, Drosophila genetics and behavioral assay) using experiment tools (human neuroblastoma cells and Drosophila fly model) to systematically dissect the ARS proteins network and to identify a common pathogenic pathway involved in CMT. Based on the mechanistic insight, I will provide new model to study CMT and a new concept to alleviate mutant-specific neurodegenerative phenotypes. Ultimately, my findings can be extended to other acquired and inherited neuropathies and will facilitate the development of pharmacological strategies for the treatment of these debilitating disease.

Researcher(s)

• Promoter: Jordanova Albena
• Co-promoter: Petrovic-Erfurth Maria-Luise
• Fellow: Morant Laura

Research team(s)

• VIB CMN - Molecular Neurogenomics

Project type(s)

• Research Project

Abstract

Peripheral neuropathies (PNs) affect 3-4% of the old (>55 years). Often, the disease manifests as result of stress (e.g. diabetes or chemotherapy). There are also hereditary forms of neuropathies. Patients experience altered sensations and pain in hands/feet as well as orthopedic and coordination problems. Hereditary PNs start in the first two decades of life. Among them Charcot- Marie Tooth disease (CMT) is the most frequent subtype which is currently, like all other PNs, incurable. Patients are only treated to relieve symptoms, leaving them ultimately severely disabled. The development of a therapy, requires a better understanding of the molecular mechanisms underlying CMT. I propose to test the role of a regulatory cellular signaling mechanisms (phosphorylation) in the CMT-etiology. As an expert in the biology of neuropathy and phosphorylation, I will perform my work in a lab specialized in CMT-genetics. My idea that phosphorylation might be critical for CMT results from a genetic screen utilizing the CMT-fly model established by my host lab. To verify these results, I have engineered human CMT-cell lines. By analyzing their signaling state via (phosphor)- proteomics, I will pinpoint the best molecular targets for future therapies. The advantage of focusing on phosphorylation is the detailed knowledge of phosphor-pathways and their modulators. I will genetically test putative drug-targets in vivo laying the foundation for the first therapy specific for CMT. -

Researcher(s)

• Promoter: Petrovic-Erfurth Maria-Luise

Research team(s)

• VIB CMN - Molecular Neurogenomics

Project type(s)

• Research Project

Abstract

Dominant intermediate Charcot-Marie-Tooth disease type C (DI-CMTC) is an incurable hereditary neurodegenerative disorder characterized by severe and progressive sensory-motor deficits. DICMTC is caused by mutations in the tyrosyl-tRNA synthetase (YARS), an essential enzyme involved in the initial steps of protein biosynthesis and therefore indispensable for cell viability. It remains enigmatic how molecular defects in this housekeeper protein could cause degeneration restricted to peripheral nerves. Our goal is to unravel the molecular mechanisms underlying YARS neurotoxicity and to translate these findings into potential pharmacological therapies for DI-CMTC. I will employ a combination of systematic "omics" approaches (proteomics, interactomics, functional genomics) and unique experimental tools (Drosophila and neuroblastoma genetic models) in order to unravel the neuronal signaling response elicited by mutant YARS proteins. The identified key molecular players will be functionally characterized and used to alleviate mutantspecific neurodegenerative phenotypes in the only existing animal model of DI-CMTC (Drosophila melanogaster). Ultimately, my findings can be extended to other inherited or acquired neuropathies and will facilitate the development of pharmacological strategies for the treatment of these debilitating diseases.

Researcher(s)

• Promoter: Jordanova Albena
• Fellow: Petrovic-Erfurth Maria-Luise

Research team(s)

• VIB CMN - Molecular Neurogenomics

Project type(s)

• Research Project