SLC7A11 Mediated Cystine Transport and Glucose-Dependent Pentose Phosphate Pathway Cooperatively Regulate Decidualization by Reducing Oxidative Stress

"This study provides novel insights into the role of SLC7A11 in regulating oxidative stress during decidualization of endometrial stromal cells. The upregulation of SLC7A11 and the activation of the pentose phosphate pathway contribute to the increased production of glutathione and the reduction of ROS levels. These findings shed light on the mechanism of cellular antioxidation during decidualization and provide theoretical references for the pathologies related to endometrium, such as endometrial-related infertility. \n\nOur research revealed that during decidualization, a process crucial for successful implantation, the cellular level of reactive oxygen species (ROS) significantly decreases, accompanied by a remarkable increase in the expression of SLC7A11, a transporter protein responsible for cystine uptake. We propose that the upregulation of SLC7A11 facilitates the conversion of cystine to the antioxidant glutathione (GSH) via the NADPH-dependent reduction pathway, thereby lowering ROS levels within the cells. Further investigation revealed a prominent activation of the pentose phosphate pathway, a metabolic pathway closely linked to NADPH synthesis, during decidualization. Moreover, the levels of glycolytic products associated with the pentose phosphate pathway were also significantly elevated. Notably, suppressing the expression of G6PD, the rate-limiting enzyme in the pentose phosphate pathway, significantly inhibited the decidualization process. \n\nIntriguingly, our findings demonstrate that under glucose deprivation conditions, decidualization induction is hindered. However, supplementation with NADPH, cystine, or GSH effectively reversed the inhibition of decidualization. We postulate that glucose deprivation leads to insufficient NADPH synthesis, resulting in decreased antioxidant levels and increased intracellular ROS, ultimately hindering decidualization. The addition of NADPH, cystine, or GSH partially reverses the elevated ROS levels, thereby mitigating the adverse effects of glucose deficiency on decidualization. \n\nThis study highlights several key innovations: Firstly, we demonstrate that SLC7A11 is upregulated during decidualization and plays a crucial role in promoting glutathione synthesis by mediating cystine transport, thereby reducing intracellular ROS levels. Secondly, we establish that the pentose phosphate pathway is activated during decidualization and is directly linked to NADPH synthesis. By inhibiting G6PD, the rate-limiting enzyme in the pentose phosphate pathway, we demonstrate the crucial role of this pathway in decidualization. Finally, we demonstrate that glucose deprivation impairs decidualization, while supplementation with NADPH, cystine, or GSH effectively reverses this inhibition. This finding provides valuable insights into the metabolic regulation of decidualization. \n\nOur findings provide compelling evidence that SLC7A11-mediated cystine transport and glucose-dependent pentose phosphate pathway-derived NADPH act synergistically to increase intracellular cystine levels, enhance antioxidant capacity, and ultimately drive the decidualization process. These findings shed new light on the cellular antioxidant mechanisms involved in decidualization and provide valuable theoretical insights for therapeutic interventions targeting endometrial-related infertility. \n\nWhile this study delves into the intricacies of decidualization, it does not directly link these findings to clinical disease. However, bioinformatics research has proposed potential associations between SLC7A11 and various reproductive disorders, such as recurrent miscarriage. Therefore, future research should prioritize exploring the relationship between reproductive diseases and SLC7A11. Furthermore, several aspects require further investigation, including the precise signaling pathways involved in these processes and the development of therapeutic strategies for diseases resulting from abnormal decidualization. These investigations hold the potential to significantly advance our understanding of this crucial biological process. \n\nHowever, further research is needed to explore the precise signaling pathways involved in these processes, as well as to investigate the potential associations between SLC7A11 and reproductive disorders. Future studies should also focus on elucidating the therapeutic strategies for diseases resulting from abnormal decidualization. \n\n"