Publications by authors named "Sueanne Chear"

Article Synopsis
  • CLN3 Batten disease is a lysosomal storage disorder characterized by retinal degeneration, seizures, motor decline, and early death, with defects in photoreceptor outer segment (POS) phagocytosis observed in patient-derived cells.
  • Researchers used CRISPR to create stem cell lines and a transgenic pig model to explore the effect of CLN3 mutations on POS phagocytosis.
  • Results showed that mutant RPE cells exhibit reduced POS uptake, leading to less efficient phagocytosis and subsequent loss of photoreceptor cells, indicating that both RPE dysfunction and mutant POS contribute to the disease's progression.
View Article and Find Full Text PDF
Article Synopsis
  • CLN3 Batten disease is a genetic disorder that begins with vision loss and progresses to seizures, motor decline, and early death; it involves a defect in the ability of retinal pigment epithelial (RPE) cells to clear out photoreceptor outer segments (POSs).
  • Researchers created mutant and control cell lines using CRISPR technology and studied their phagocytosis capabilities, along with examining a genetically modified Yucatan miniswine for further insights.
  • Results showed that RPE cells from mutants had reduced binding and uptake of POSs, leading to less lipofuscin accumulation and significant photoreceptor loss over time, indicating that both RPE dysfunction and mutant POSs play crucial roles in CLN3 disease.
View Article and Find Full Text PDF

CLN3 disease is a lysosomal storage disorder associated with fatal neurodegeneration that is caused by mutations in CLN3, with most affected individuals carrying at least one allele with a 966 bp deletion. Using CRISPR/Cas9, we corrected the 966 bp deletion mutation in human induced pluripotent stem cells (iPSCs) of a compound heterozygous patient (CLN3 Δ 966 bp and E295K). We differentiated these isogenic iPSCs, and iPSCs from an unrelated healthy control donor, to neurons and identified disease-related changes relating to protein synthesis, trafficking and degradation, and in neuronal activity, which were not apparent in CLN3-corrected or healthy control neurons.

View Article and Find Full Text PDF

Genetically encoded fluorescent biosensors (GEFBs) enable researchers to visualize and quantify cellular processes in live cells. Induced pluripotent stem cells (iPSCs) can be genetically engineered to express GEFBs via integration into the Adeno-Associated Virus Integration Site 1 (AAVS1) safe harbor locus. This can be achieved using CRISPR/Cas ribonucleoprotein targeting to cause a double-strand break at the AAVS1 locus, which subsequently undergoes homology-directed repair (HDR) in the presence of a donor plasmid containing the GEFB sequence.

View Article and Find Full Text PDF

Excitotoxicity is a feature of many neurodegenerative diseases and acquired forms of neural injury that is characterized by disruption of neuronal morphology. This is typically seen as beading and fragmentation of neurites when exposed to excitotoxins such as the AMPA receptor agonist kainic acid, with the extent to which these occur used to quantitate neurodegeneration. Induced pluripotent stem cells (iPSCs) provide a means to generate human neurons in vitro for mechanistic studies and can thereby be used to investigate how cells respond to excitotoxicity and to identify or test potential neuroprotective agents.

View Article and Find Full Text PDF

Short-chain quinones (SCQs) have been investigated as potential therapeutic candidates against mitochondrial dysfunction, which was largely thought to be associated with the reversible redox characteristics of their active quinone core. We recently reported a library of SCQs, some of which showed potent cytoprotective activity against the mitochondrial complex I inhibitor rotenone in the human hepatocarcinoma cell line HepG2. To better characterize the cytoprotection of SCQs at a molecular level, a bioactivity profile for 103 SCQs with different compound chemistries was generated that included metabolism related markers, redox activity, expression of cytoprotective proteins and oxidative damage.

View Article and Find Full Text PDF