51. Abnormal expression of CUX1influences autophagy activation in paroxysmal nocturnal hemoglobinuria
- Author
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Wu, Junshu, Li, Liyan, Liu, Zhaoyun, Wang, Honglei, Chen, Yingying, Zeng, Lijie, Wang, Guanrou, Liu, Hui, and Fu, Rong
- Abstract
The mechanism underlying autophagy in paroxysmal nocturnal hemoglobinuria (PNH) remains largely unknown. We previously sequenced the entire genome exon of the CD59– cells from 13 patients with PNH and found genes such as CUX1encoding Cut-like homeobox 1. Peripheral blood samples from 9 patients with PNH and 7 healthy control subjects were obtained to measure CUX1expression. The correlation between CUX1messenger RNA expression and PNH clinical indicators was analyzed. To simulate CUX1expression in patients with PNH, we generated a panel of PNH cell lines by knocking out PIGAin K562 cell lines and transfected lentivirus with CUX1. CCK-8 and EDU assay assessed cell proliferation. Western blotting was used to detect Beclin-1, LC3A, LC3B, ULK1, PI3K, AKT, p-AKT, mTOR, and p-mTOR protein levels. Autophagosomes were observed with transmission electron microscopy. Chloroquine was used to observe CUX1expression in PNH after autophagy inhibition. Leukocytes from patients with PNH had lower levels of CUX1messenger RNA expression and protein content than healthy control subjects. The lactose dehydrogenase level and the percentage of PNH clones were negatively correlated with CUX1relative expression. We reduced CUX1expression in a PIGAknockout K562 cell line, leading to increased cell proliferation. Levels of autophagy markers Beclin-1, LC3B, LC3A, and ULK1 increased, and autophagosomes increased. Furthermore, PI3K/AKT/mTOR protein phosphorylation levels were lower. CUX1expression did not change and cell proliferation decreased in CUX1 knocked down PNH cells after inhibition of autophagy by chloroquine. In brief, CUX1loss-of-function mutation resulted in stronger autophagy in PNH.Loss-of-function mutation in the CUX1 gene results in relatively stronger autophagy in paroxysmal nocturnal hemoglobinuria.
- Published
- 2024
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