Targeting NRF2 uncovered an intrinsic susceptibility of acute myeloid leukemia cells to ferroptosis.

Drug resistance and poor treatment response are major obstacles to the effective treatment of acute myeloid leukemia (AML). A deeper understanding of the mechanisms regulating drug resistance and response genes in AML is therefore urgently needed. Our previous research has highlighted the important role of nuclear factor E2-related factor 2 (NRF2) in AML, where it plays a critical role in detoxifying reactive oxygen species and influencing sensitivity to chemotherapy. In this study, we identify a core set of direct NRF2 targets that are involved in ferroptosis, a novel form of cell death. Of particular interest, we find that glutathione peroxidase 4 (GPX4) is a key ferroptosis gene that is consistently upregulated in AML, and high expression of GPX4 is associated with poor prognosis for AML patients. Importantly, simultaneous inhibition of NRF2 with ML385 and GPX4 with FIN56 or RSL3 synergistically targets AML cells, triggering ferroptosis. Treatment with ML385 + FIN56/RSL3 resulted in a marked reduction in NRF2 and GPX4 expression. Furthermore, NRF2 knockdown enhanced the sensitivity of AML cells to the ferroptosis inducers. Taken together, our results suggest that combination therapy targeting both NRF2 and GPX4 may represent a promising approach for the treatment of AML.

DEFB126 polymorphisms and association with idiopathic asthenozoospermia in China.

Idiopathic asthenozoospermia, a common factor in male infertility, is characterized by altered sperm motility function in fresh ejaculate. Although the ß-defensin 126 (DEFB126) protein is associated with asthenozoospermia, DEFB126 gene polymorphisms have not been extensively studied. Therefore, the association between DEFB126 gene polymorphisms and asthenozoospermia requires further investigation. Screening was performed by semen analysis, karyotype analysis, and Y microdeletion detection, and 102 fertile men and 106 men with asthenozoospermia in Chengdu, China, were selected for DEFB126 gene sequence analyses. Seven nucleotide mutations and two nucleotide deletions in the DEFB126 gene were detected. rs11467417 (317-318 del/del), rs11467497 (163-166 wt/del), c.152T>C, and c.227A>G were significantly different between the control and asthenozoospermia groups, likely representing high-risk genetic factors for asthenozoospermia among males. DEFB126 expression was not observed in sperm with rs11467497 homozygous deletion and was unstable in sperm with rs11467417 homozygous deletion. The rs11467497 four-nucleotide deletion leads to truncation of DEFB126 at the carboxy-terminus, and the rs11467417 binucleotide deletion produces a non-stop messenger RNA (mRNA). The above deletions may be responsible for male hypofertility and infertility by reducing DEFB126 affinity to sperm surfaces. Based on in silico analysis, the amino acids 51M and 76K are located in the highly conserved domain; c.152T>C (M51T) and c.227A>G (K76R) are predicted to be damaging and capable of changing alternative splice, structural and posttranslational modification sites of the RNA, as well as the secondary structure, structural stability, and hydrophobicity of the protein, suggesting that these mutations are associated with asthenozoospermia.