Functional impact of PCSK9 variants on LDL uptake in a knockout hepatic model
- 1Collaborative Innovation Center for Translation Medical Testing and Application Technology, Department of Medical Technology, Zhangzhou Health Vocational College, Zhangzhou, Fujian, People's Republic of China
- 2Department of Basic Medicine, Zhangzhou Health Vocational College, Zhangzhou, Fujian, People's Republic of China
- 3Department of Science and Technology, Zhangzhou Health Vocational College, Zhangzhou, Fujian, People's Republic of China
Abstract
Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a central regulator of low-density lipoprotein (LDL) cholesterol metabolism, yet the functional consequences of many clinically observed PCSK9 variants remain unknown. To establish a rigorous system for quantitative variant assessment, we generated a PCSK9 knockout (KO) HepG2 cell line through CRISPR/Cas9-mediated deletion of exons 2–8, effectively removing both the prodomain and catalytic regions required for PCSK9 function. This null background enabled systematic functional mapping of wild-type (WT) PCSK9 and multiple clinically relevant variants representing well-characterized, recurrent, and previously understudied alleles. Functional assays revealed pronounced heterogeneity among variant activities. The classical gain-of-function (GOF) variants D374Y and R496W exhibited robust suppression of LDL uptake, whereas A443T—an infrequently reported and previously uncharacterized variant—demonstrated a loss-of-function (LOF)-like phenotype with significantly enhanced LDL uptake. Additional poorly characterized variants, including V4I, R104C/V114A, and R496W/N425S, displayed varied functional profiles, providing novel mechanistic insights. Surface LDL receptor (LDLR) levels generally correlated with LDL uptake but revealed unique patterns for specific variants. This KO-based rescue system provides a high-resolution framework for mechanistic classification of both established and poorly characterized PCSK9 variants, bridging the gap between genetic discovery and functional interpretation while supporting precision lipid-lowering strategies.
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BibTeX
@article{li2026functional,
title = {{Functional impact of PCSK9 variants on LDL uptake in a knockout hepatic model}},
author = {Hongmei Li and Huili Liu and Wenxin Xu and Yuanjun Zeng and Pengfei Huang and Jiawang Guo and Binxiang Cai and Yajing Chen and Yanyan Lin and Chunbin Zhang},
journal = {PLOS One},
year = {2026},
month = oct,
doi = {10.1371/journal.pone.0345908},
url = {https://doi.org/10.1371/journal.pone.0345908},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Functional impact of PCSK9 variants on LDL uptake in a knockout hepatic model
AU - Hongmei Li
AU - Huili Liu
AU - Wenxin Xu
AU - Yuanjun Zeng
AU - Pengfei Huang
AU - Jiawang Guo
AU - Binxiang Cai
AU - Yajing Chen
AU - Yanyan Lin
AU - Chunbin Zhang
PY - 2026
DA - 2026/10/26
JO - PLOS One
DO - 10.1371/journal.pone.0345908
UR - https://doi.org/10.1371/journal.pone.0345908
AB - Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a central regulator of low-density lipoprotein (LDL) cholesterol metabolism, yet the functional consequences of many clinically observed PCSK9 variants remain unknown. To establish a rigorous system for quantitative variant assessment, we generated a PCSK9 knockout (KO) HepG2 cell line through CRISPR/Cas9-mediated deletion of exons 2–8, effectively removing both the prodomain and catalytic regions required for PCSK9 function. This null background enabled systematic functional mapping of wild-type (WT) PCSK9 and multiple clinically relevant variants representing well-characterized, recurrent, and previously understudied alleles. Functional assays revealed pronounced heterogeneity among variant activities. The classical gain-of-function (GOF) variants D374Y and R496W exhibited robust suppression of LDL uptake, whereas A443T—an infrequently reported and previously uncharacterized variant—demonstrated a loss-of-function (LOF)-like phenotype with significantly enhanced LDL uptake. Additional poorly characterized variants, including V4I, R104C/V114A, and R496W/N425S, displayed varied functional profiles, providing novel mechanistic insights. Surface LDL receptor (LDLR) levels generally correlated with LDL uptake but revealed unique patterns for specific variants. This KO-based rescue system provides a high-resolution framework for mechanistic classification of both established and poorly characterized PCSK9 variants, bridging the gap between genetic discovery and functional interpretation while supporting precision lipid-lowering strategies.
SN - 1932-6203
ER -