Biology subjects

Lisowski, P.

Publications and source records attributed to Lisowski, P..

5 recordsLinked to original sources

bioRxiv2026

Mitochondrial genome editing reveals the impact of complex I heteroplasmic variants on human neurogenesis

Mitochondrial DNA (mtDNA) variants, whether maternally inherited or acquired somatically during aging, can be particularly detrimental to cells that rely on mitochondrial metabolism such as neurons. The functional consequences of mtDNA variants are thought to depend on their heteroplasmy, defined as the proportion of mtDNA molecules carrying that variant. However, investigating the specific effects of heteroplasmic mtDNA variants on human neuronal function has been challenging. Studies using patient-derived cells cannot conclusively attribute observed phenotypes to a single mtDNA variant, while conventional genome editing approaches are not applicable to mtDNA. Here, we use DddA-derived cytosine base editor (DdCBE) to introduce pathogenic heteroplasmic mtDNA variants into Neurogenin 2 (NGN2)-inducible human induced pluripotent stem cells (iPSCs). We focus on two variants in the genes MT-ND1 and MT-ND5 belonging to complex I (CI), the largest component of the mitochondrial respiratory chain and a frequent contributor to human disease, including the incurable neurodevelopmental disorder Leigh syndrome. mtDNA-edited iPSC lines exhibit low off-target editing and maintain similar heteroplasmy following subclonal isolation and differentiation into NGN2-induced neurons (iNs). Although the CI variants do not substantially affect mitochondrial energy metabolism in undifferentiated iPSCs, they reduce mitochondrial membrane potential in iNs where they drive a transcriptional reprogramming indicative of impaired neuronal commitment. These findings suggest that heteroplasmic CI variants are sufficient to disrupt neural fate specification even at relatively low heteroplasmy. More broadly, mtDNA editing in human iPSCs provides a powerful platform to investigate how mitochondrial fitness and heteroplasmy influence development and disease.

bioengineering↗

bioRxiv2024

Deep learning-driven neuromorphogenesis screenings identify repurposable drugs for mitochondrial disease

Mitochondrial disease encompasses untreatable conditions affecting tissues with high energy demands. A severe manifestation of mitochondrial disease is Leigh syndrome (Leigh), which causes defects in basal ganglia and midbrain regions, psychomotor regression, lactic acidosis, and early death. We previously generated isogenic pairs of Leigh cerebral organoids and uncovered defects in neuromorphogenesis. Here, we leveraged on this disease feature to devise drug discovery pipelines. We developed a deep learning algorithm tailored for cell type-specific drug repurposing to identify drugs capable of promoting neuronal commitment. In parallel, we performed a survival drug screen in yeast and validated the repurposable hits on branching capacity in Leigh neurons. The two approaches independently highlighted azole compounds, Talarozole and Sertaconazole, both of which lowered lactate release and improved neurogenesis and neurite organization in Leigh midbrain organoids. Hence, targeting neuromorphogenesis has led to identify potential new drugs for mitochondrial disease and could prove an effective strategy for further drug discovery.

neuroscience↗

bioRxiv2023

Mutant Huntingtin impairs neurodevelopment in human brain organoids through CHCHD2-mediated neurometabolic failure

Expansion of the glutamine tract (poly-Q) in the protein Huntingtin (HTT) causes the neurodegenerative disorder Huntingtons disease (HD). Emerging evidence suggests that mutant HTT (mHTT) disrupts brain development. To gain mechanistic insights into the neurodevelopmental impact of human mHTT, we engineered induced pluripotent stem cells to introduce a biallelic or monoallelic mutant 70Q expansion or to remove the poly-Q tract of HTT. 70Q introduction caused aberrant development of cerebral organoids with loss of neural progenitor organization. The early neurodevelopmental signature of mHTT highlighted the dysregulation of the protein coiled-coil-helix-coiled-coil-helix domain containing 2 (CHCHD2), a transcription factor involved in mitochondrial integrated stress response. CHCHD2 repression was associated with abnormal mitochondrial morpho-dynamics and elevated resting energy expenditure. Elimination of the poly-Q tract of HTT normalized CHCHD2 expression and mitochondrial defects. Hence, mHTT-mediated disruption of human neurodevelopment is paralleled by aberrant neurometabolic programming mediated by dysregulation of CHCHD2, which could then serve as an early intervention target for HD.

neuroscience↗

bioRxiv2022

Methylation genome wide profiling in lowly and highly efficient adipose somatic cell nuclear transfer in pigs

Swine is a common model organism for biomedical research. Epigenetic reprogramming in SCNT embryos does not fully recapitulate the natural DNA demethylation events at fertilisation. This study aimed to conduct a genome-wide methylation profiling to detect differentially methylated regions (DMRs) responsible for epigenetic differences in stem cells that displayed high and low efficiency of SCNT and to elucidate the low efficiency of cloning rate in pigs. Adipose tissue mesenchymal stem cells (AMSC)s lines were isolated from adipose tissue of adult male pigs (n=20; high-efficiency cells=10; low efficiency cells= 10). Reduced representation bisulfite sequencing (RRBS) was performed on an Illumina HiSeq1500. Paired-end reads were filtered to remove the adapter contamination, and low-quality reads using TrimGalore!. Filtered reads were mapped to the reference genome using Bismark. MethylKit was used to identify differentially methylated regions (DMRs) (bases and tiles), showing statistically significant differential methylation between two groups: high and low-efficiency AMSCs. Hierarchical cluster analysis according to methylation patterns clearly defined groups with low and high cloning efficiency. We report 3704 bases with statistically significant differences in methylation and 10062 tiles with statistically significant differences in methylation. Most differentially methylated sites are intergenic 62%, 31% are intronic, 4% are located in exons and 4% in promoters. 37% of differentially methylated sites are located in known CpG islands (CGIs) and 4% in CpG island shores (CGSs).

genetics↗

bioRxiv2019

SURF1 mutations causative of Leigh syndrome impair human neurogenesis

Mutations in the mitochondrial complex IV assembly factor SURF1 represent a major cause of Leigh syndrome (LS), a rare fatal neurological disorder. SURF1-deficient animals have failed to recapitulate the neuronal pathology of human LS, hindering our understanding of the disease mechanisms. We generated induced pluripotent stem cells from LS patients carrying homozygous SURF1 mutations (SURF1 iPS) and performed biallelic correction via CRISPR/Cas9. In contrast to corrected cells, SURF1 iPS showed impaired neuronal differentiation. Aberrant bioenergetics in SURF1 iPS occurred already in neural progenitor cells (NPCs), disrupting their neurogenic potency. Cerebral organoids from SURF1 iPS were smaller and recapitulated the neurogenesis defects. Our data imply that SURF1 mutations cause a failure in the development of maturing neurons. Using NPC function as an interventional target, we identified SURF1 gene augmentation as a potential strategy for restoring neurogenesis in LS patients carrying SURF1 mutations.

neuroscience↗