Browsing by Author "Mok, Kin Y."

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    An IL1RL1 genetic variant lowers soluble ST2 levels and the risk effects of APOE-ε4 in female patients with Alzheimer’s disease
    (Springer Nature, 2022) Jiang, Yuanbing; Zhou, Xiaopu; Wong, Hiu Yi; Ouyang, Li; Ip, Fanny C. F.; Chau, Vicky M. N.; Lau, Shun-Fat; Wu, Wei; Wong, Daniel Y. K.; Seo, Heukjin; Fu, Wing-Yu; Lai, Nicole C. H.; Chen, Yuewen; Chen, Yu; Tong, Estella P. S.; Alzheimer’s Disease Neuroimaging Initiative; Mok, Vincent C. T.; Kwok, Timothy C. Y.; Mok, Kin Y.; Shoai, Maryam; Lehallier, Benoit; Morán Losada, Patricia; O'Brien, Eleanor; Porter, Tenielle; Laws, Simon M.; Hardy, John; Wyss-Coray, Tony; Masters, Colin L.; Fu, Amy K. Y.; Ip, Nancy Y.; Radiology and Imaging Sciences, School of Medicine
    Changes in the levels of circulating proteins are associated with Alzheimer's disease (AD), whereas their pathogenic roles in AD are unclear. Here, we identified soluble ST2 (sST2), a decoy receptor of interleukin-33-ST2 signaling, as a new disease-causing factor in AD. Increased circulating sST2 level is associated with more severe pathological changes in female individuals with AD. Genome-wide association analysis and CRISPR-Cas9 genome editing identified rs1921622 , a genetic variant in an enhancer element of IL1RL1, which downregulates gene and protein levels of sST2. Mendelian randomization analysis using genetic variants, including rs1921622 , demonstrated that decreased sST2 levels lower AD risk and related endophenotypes in females carrying the Apolipoprotein E (APOE)-ε4 genotype; the association is stronger in Chinese than in European-descent populations. Human and mouse transcriptome and immunohistochemical studies showed that rs1921622 /sST2 regulates amyloid-beta (Aβ) pathology through the modulation of microglial activation and Aβ clearance. These findings demonstrate how sST2 level is modulated by a genetic variation and plays a disease-causing role in females with AD.
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    C9orf72 Intermediate Repeats are Associated with Corticobasal Degeneration, Increased C9orf72 Expression and Disruption of Autophagy
    (Springer, 2019-11) Cali, Christopher P.; Patino, Maribel; Tai, Yee Kit; Ho, Wan Yun; McLean, Catriona A.; Morris, Christopher M.; Seeley, William W.; Miller, Bruce L.; Gaig, Carles; Vonsattel, Jean Paul G.; White, Charles L.; Roeber, Sigrun; Kretzschmar, Hans; Troncoso, Juan C.; Troakes, Claire; Gearing, Marla; Ghetti, Bernardino; Van Deerlin, Vivianna M.; Lee, Virginia M.-Y.; Trojanowski, John Q.; Mok, Kin Y.; Ling, Helen; Dickson, Dennis W.; Schellenberg, Gerard D.; Ling, Shuo-Chien; Lee, Edward B.; Pathology and Laboratory Medicine, School of Medicine
    Microsatellite repeat expansion disease loci can exhibit pleiotropic clinical and biological effects depending on repeat length. Large expansions in C9orf72 (100s-1000s of units) are the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal degeneration (FTD). However, whether intermediate expansions also contribute to neurodegenerative disease is not well understood. Several studies have identified intermediate repeats in Parkinson’s disease patients, but the association was not found in autopsy confirmed cases. We hypothesized that intermediate C9orf72 repeats are a genetic risk factor for corticobasal degeneration (CBD), a neurodegenerative disease that can be clinically similar to Parkinson’s but has distinct tau protein pathology. Indeed, intermediate C9orf72 repeats were significantly enriched in autopsy-proven CBD (n=354 cases, odds ratio=3.59, p-value=0.00024). While large C9orf72 repeat expansions are known to decrease C9orf72 expression, intermediate C9orf72 repeats result in increased C9orf72 expression in human brain tissue and CRISPR/cas9 knockin iPSC derived neural progenitor cells. In contrast to cases of FTD/ALS with large C9orf72 expansions, CBD with intermediate C9orf72 repeats was not associated with pathologic RNA foci or dipeptide repeat protein aggregates. Knock-in cells with intermediate repeats exhibit numerous changes in gene expression pathways relating to vesicle trafficking and autophagy. Additionally, overexpression of C9orf72 without the repeat expansion leads to defects in autophagy under nutrient starvation conditions. These results raise the possibility that therapeutic strategies to reduce C9orf72 expression may be beneficial for the treatment of CBD.