In vitro modeling of neuronal ceroid lipofuscinosis (NCL): Patient fibroblasts and their reprogrammed derivatives as human models of NCL

The discovery of resetting human somatic cells via introduction of four transcription factors into an embryonic stem cell-like state that enables the generation of any cell type of the human body has revolutionized the field of medical science. The generation of patient-derived iPSCs and the subsequent differentiation into the cells of interest has been, nowadays, widely used as model system for various inherited diseases. The aim of this thesis was to generate iPSCs and to subsequently derive NPCs which can be differentiated into neurons in order to model the two most common forms of the NCLs: LINCL which is caused by mutations within the TPP1 gene, encoding a lysosomal enzyme, and JNCL which is caused by mutations within the CLN3 gene, affecting a lysosomal transmembrane protein. It was shown that patient-derived fibroblasts can be successfully reprogrammed into iPSCs by using retroviral vectors that introduced the four transcription factors POU5F1, SOX2, KLF4 and MYC. The generated iPSCs were subsequently differentiated into expandable NPCs and finally into mature neurons. Phenotype analysis during the different stages, namely pluripotent iPSCs, multipotent NPCs and finally differentiated neurons, revealed a genotype-specific progression of the disease. The earliest events were observed in organelle disruption such as mitochondria, Golgi and ER which preceded the accumulation of subunit c of the mitochondrial ATPase complex that was only apparent in neurons. However, none of these events led to neurodegeneration in vitro. The established disease models recapitulate phenotypes reported in other NCL disease models such as mouse, dog and sheep model systems. More importantly, the hallmark of the NCLs, accumulation of subunit c in neurons, could be reproduced during the course of disease modeling which demonstrates the suitability of the established system. Moreover, the derived expandable NPC populations can be used for further applications in drug screenings. Their robust phenotypes such as low levels of TPP1 activity in LINCL patient-derived NPCs or cytoplasmic vacuoles, containing storage material, observed in CLN3 mutant NPCs, should serve as possible phenotypic read-outs

Impaired DNA damage response signaling by FUS-NLS mutations leads to neurodegeneration and FUS aggregate formation

Amyotrophic lateral sclerosis (ALS) is the most frequent motor neuron disease. Cytoplasmic fused in sarcoma (FUS) aggregates are pathological hallmarks of FUS-ALS. Proper shuttling between the nucleus and cytoplasm is essential for physiological cell function. However, the initial event in the pathophysiology of FUS-ALS remains enigmatic. Using human induced pluripotent stem cell (hiPSCs)-derived motor neurons (MNs), we show that impairment of poly(ADP-ribose) polymerase (PARP)-dependent DNA damage response (DDR) signaling due to mutations in the FUS nuclear localization sequence (NLS) induces additional cytoplasmic FUS mislocalization which in turn results in neurodegeneration and FUS aggregate formation. Our work suggests that a key pathophysiologic event in ALS is upstream of aggregate formation. Targeting DDR signaling could lead to novel therapeutic routes for ameliorating ALS

In vitro modeling of neuronal ceroid lipofuscinosis (NCL): Patient fibroblasts and their reprogrammed derivatives as human models of NCL

The discovery of resetting human somatic cells via introduction of four transcription factors into an embryonic stem cell-like state that enables the generation of any cell type of the human body has revolutionized the field of medical science. The generation of patient-derived iPSCs and the subsequent differentiation into the cells of interest has been, nowadays, widely used as model system for various inherited diseases. The aim of this thesis was to generate iPSCs and to subsequently derive NPCs which can be differentiated into neurons in order to model the two most common forms of the NCLs: LINCL which is caused by mutations within the TPP1 gene, encoding a lysosomal enzyme, and JNCL which is caused by mutations within the CLN3 gene, affecting a lysosomal transmembrane protein. It was shown that patient-derived fibroblasts can be successfully reprogrammed into iPSCs by using retroviral vectors that introduced the four transcription factors POU5F1, SOX2, KLF4 and MYC. The generated iPSCs were subsequently differentiated into expandable NPCs and finally into mature neurons. Phenotype analysis during the different stages, namely pluripotent iPSCs, multipotent NPCs and finally differentiated neurons, revealed a genotype-specific progression of the disease. The earliest events were observed in organelle disruption such as mitochondria, Golgi and ER which preceded the accumulation of subunit c of the mitochondrial ATPase complex that was only apparent in neurons. However, none of these events led to neurodegeneration in vitro. The established disease models recapitulate phenotypes reported in other NCL disease models such as mouse, dog and sheep model systems. More importantly, the hallmark of the NCLs, accumulation of subunit c in neurons, could be reproduced during the course of disease modeling which demonstrates the suitability of the established system. Moreover, the derived expandable NPC populations can be used for further applications in drug screenings. Their robust phenotypes such as low levels of TPP1 activity in LINCL patient-derived NPCs or cytoplasmic vacuoles, containing storage material, observed in CLN3 mutant NPCs, should serve as possible phenotypic read-outs

In vitro modeling of neuronal ceroid lipofuscinosis (NCL): Patient fibroblasts and their reprogrammed derivatives as human models of NCL

The discovery of resetting human somatic cells via introduction of four transcription factors into an embryonic stem cell-like state that enables the generation of any cell type of the human body has revolutionized the field of medical science. The generation of patient-derived iPSCs and the subsequent differentiation into the cells of interest has been, nowadays, widely used as model system for various inherited diseases. The aim of this thesis was to generate iPSCs and to subsequently derive NPCs which can be differentiated into neurons in order to model the two most common forms of the NCLs: LINCL which is caused by mutations within the TPP1 gene, encoding a lysosomal enzyme, and JNCL which is caused by mutations within the CLN3 gene, affecting a lysosomal transmembrane protein. It was shown that patient-derived fibroblasts can be successfully reprogrammed into iPSCs by using retroviral vectors that introduced the four transcription factors POU5F1, SOX2, KLF4 and MYC. The generated iPSCs were subsequently differentiated into expandable NPCs and finally into mature neurons. Phenotype analysis during the different stages, namely pluripotent iPSCs, multipotent NPCs and finally differentiated neurons, revealed a genotype-specific progression of the disease. The earliest events were observed in organelle disruption such as mitochondria, Golgi and ER which preceded the accumulation of subunit c of the mitochondrial ATPase complex that was only apparent in neurons. However, none of these events led to neurodegeneration in vitro. The established disease models recapitulate phenotypes reported in other NCL disease models such as mouse, dog and sheep model systems. More importantly, the hallmark of the NCLs, accumulation of subunit c in neurons, could be reproduced during the course of disease modeling which demonstrates the suitability of the established system. Moreover, the derived expandable NPC populations can be used for further applications in drug screenings. Their robust phenotypes such as low levels of TPP1 activity in LINCL patient-derived NPCs or cytoplasmic vacuoles, containing storage material, observed in CLN3 mutant NPCs, should serve as possible phenotypic read-outs

Impaired DNA damage response signaling by FUSNLS mutations leads to neurodegeneration and FUS aggregate formation

Contains fulltext : 198309.pdf (publisher's version ) (Open Access)17 p

Human Adult White Matter Progenitor Celts Are Multipotent Neuroprogenitors Similar to Adult Hippocampal Progenitors

Adult neural progenitor cells (aNPC) are a potential autologous cell source for cell replacement in neurologic diseases or for cell-based gene therapy of neurometabolic diseases. Easy accessibility, long-term expandability, and detailed characterization of neural progenitor cell (NPC) properties are important requisites for their future translational/clinical applications. aNPC can be isolated from different regions of the adult human brain, including the accessible subcortical white matter (aNPC_(WM)), but systematic studies comparing long-term expanded aNPC_(WM) with aNPC from neurogenic brain regions are not available. Freshly isolated cells from subcortical white matter and hippocampus expressed oligodendrocyte progenitor cell markers such as A2B5, neuron-glial antigen 2 (NG2), and oligodendrocyte transcription factor 2 (OLIG2) in ∼20% of cells but no neural stem cell (NSC) markers such as CD133 (Prominin1), Nestin, SOX2, or PAX6. The epidermal growth factor receptor protein was expressed in 18% of aNPC_(WM) and 7% of hippocampal aNPC (aNPC_(HIP)), but only a small fraction of cells, 1 of 694 cells from white matter and 1 of 1,331 hippocampal cells, was able to generate neurospheres. Studies comparing subcortical aNPC_(WM) with their hippocampal counterparts showed that both NPC types expressed mainly markers of glial origin such as NG2, A2B5, and OLIG2, and the NSC/NPC marker Nestin, but no pericyte markers. Both NPC types were able to produce neurons, astrocytes, and oligodendrocytes in amounts comparable to fetal NSC. Whole transcriptome analyses confirmed the strong similarity of aNPC_(WM) to aNPC_(HIP). Our data show that aNPC_(WM) are multipotent NPC with long-term expandability similar to NPC from hippocampus, making them a more easily accessible source for possible autologous NPC-based treatment strategies