Center for Global Health, Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing, China.
Department of Pathology, The Affiliated Drum Tower Hospital, Medical School of Nanjing University, Nanjing, China.
Environ Toxicol. 2022 Aug;37(8):2103-2114. doi: 10.1002/tox.23554. Epub 2022 May 4.
Coal workers' pneumoconiosis (CWP) is a type of typical occupational lung disease caused by prolonged inhalation of coal mine dust. The individuals' different genetic background may underlie their different susceptibility to develop pneumoconiosis, even under the same exposure level. This study aimed to identify susceptibility genes associated with CWP. Based on our previous genome-wide association study (GWAS, 202 CWP cases vs. 198 controls) and gene expression data obtained by analyzing human lungs and whole blood from the Genotype-Tissue Expression (GTEx) Portal, a transcriptome-wide association study (TWAS) was applied to identify CWP risk-related genes. Luciferase report gene assay, qRT-PCR, Western blot, immunofluorescence assay, and TUNEL assay were conducted to explore the potential role of the candidate gene in CWP. Proteasome 20S subunit beta 9 (PSMB9) was identified as a strong risk-related gene of CWP in both lungs and whole blood (Lungs: P = 4.22 × 10 ; Whole blood: P = 2.11 × 10 ). Single nucleotide polymorphisms (SNPs) rs2071480 and rs1351383, which locate in the promoter region and the first intron of the PSMB9 gene, were in high linkage disequilibrium (LD, r = 0.98) with the best GWAS SNP rs4713600 (G>T, OR = 0.55, 95% CI: 0.42-0.74, P = 6.86 × 10 ). Both rs2071480 and rs1351383 significantly enhanced the transcriptional activity of PSMB9. Functional experiments revealed that silica exposure remarkably reduced the PSMB9 expression and caused cell apoptosis, while overexpression of PSMB9 markedly abolished silica-induced cell apoptosis. We here identified PSMB9 as a novel susceptibility gene for CWP and provided important insights into the further exploration of the CWP pathogenesis.
煤工尘肺（CWP）是一种由长期吸入煤矿粉尘引起的典型职业性肺部疾病。个体不同的遗传背景可能导致他们在相同的暴露水平下对尘肺病的易感性不同。本研究旨在鉴定与 CWP 相关的易感基因。基于我们之前的全基因组关联研究（GWAS，202 例 CWP 病例与 198 例对照）和通过分析人类肺部和来自 Genotype-Tissue Expression（GTEx）门户的全血获得的基因表达数据，进行了转录组全关联研究（TWAS），以鉴定 CWP 风险相关基因。进行了荧光素酶报告基因检测、qRT-PCR、Western blot、免疫荧光检测和 TUNEL 检测，以探讨候选基因在 CWP 中的潜在作用。蛋白酶体 20S 亚基β9（PSMB9）在肺部和全血中均被鉴定为 CWP 的强风险相关基因（肺部：P=4.22×10；全血：P=2.11×10）。位于 PSMB9 基因启动子区域和第一内含子的单核苷酸多态性（SNP）rs2071480 和 rs1351383 与最佳 GWAS SNP rs4713600（G>T，OR=0.55，95%CI：0.42-0.74，P=6.86×10）高度连锁不平衡（LD，r=0.98）。rs2071480 和 rs1351383 均显著增强了 PSMB9 的转录活性。功能实验表明，二氧化硅暴露显著降低了 PSMB9 的表达并导致细胞凋亡，而过表达 PSMB9 则明显消除了二氧化硅诱导的细胞凋亡。我们在这里鉴定了 PSMB9 作为 CWP 的一个新的易感基因，并为进一步探索 CWP 发病机制提供了重要的见解。
