Salubrinal, a novel inhibitor of eIF‐2α dephosphorylation, promotes erythropoiesis at early stage targeted by ufmylation pathway

Abstract

Ufmylation was proved to play a crucial role in hematopoietic stem cell (HSC) survival and erythroid differentiation, ufmylation deficiency induces acute anemia and lethality of embryos and adults in mouse models. To screen some compounds to rescue phenotypes induced by gene deletion, in this study, we used DDRGK1F/F; CreERT2 conditional knockout mice, DDRGK1F/F; CreERT2 bone marrow (BM) and fetal liver cells (FL), Uba5, and DDRGK1 knockdown human CD34 cell in vivo and in vitro, we found salubrinal, a novel inhibitor of eIF‐2α dephosphorylation, promoted erythropoiesis at early stage, and partly rescued the acute anemia induce by DDRGK1 deficiency through upregulation of ufmylation and erythroid transcription factors. In phenylhydrazine (PHZ)‐induced hemolytic anemia mice, interestingly, salubrinal could significantly improve hemocrit and red blood cell (RBC) indices of the mice treated with PHZ via upregulation of ufmylation. Its novel function was verified to attenuate unfolded protein response (UPR) and cell death programs, and to keep endoplasmic reticulum (ER) homeostasis in HSCs. Taken together results, it suggested that salubrinal may be a promising antianemic agent targeted by ufmylation.

Ufbp1, a Key Player of Ufm1 Conjugation System, Protects Against Ketosis-Induced Liver Injury via Suppressing Smad3 Activation

“…Preparing enough Ufbp1 tamoxifen-inducible CKO mice ( Ufbp1 fl/fl : ROSA26-Cre ERT2), the details could refer to our previous reports ( Cai et al, 2015 ; Chen et al, 2019 ). Taking embryos of 14.5 days from pregnant Ufbp1 fl/fl : Rosa26-Cre ERT2 mice, we got rid of the limbs and internal organs and kept the trunk, trypsinize, final cultured fibroblasts, then fibroblasts were transfected with large T lentivirus, screening the positive immortalized cells with puromycin (1.5 μg/ml) after 2 days, expand the positive cells, adding 4-hydroxytamoxifen (1 μM, Sigma-Aldrich, United States, H6278) for 4 days to knockout (KO) Ufbp1 .…”

“…It has been reported that Ufbp1 is present in the ER fraction and its deficiency impairs ER expansion in plasma cells by modulating distinct branches of the unfolded protein response ( Zhu et al, 2019a ), and Ufbp1 together with other ingredients of Ufm1 are able to combat apoptosis caused by ER stress ( Lemaire et al, 2011 ). Our previous study has demonstrated that Ufbp1 is vital for the survival of hematopoietic stem and progenitor cells through maintaining ER homeostasis ( Cai et al, 2015 ; Chen et al, 2019 ). However, ER stress is closely involved in liver inflammation and hepatocyte pyroptotic death by inducing NLRP3 inflammasome activation, eventually causing liver cancer ( Lebeaupin et al, 2015 ).…”

Salubrinal induces fetal hemoglobin expression via the stress-signaling pathway in human sickle erythroid progenitors and sickle cell disease mice

“…The net result of this action is to interfere with the recruitment of phosphorylated eukaryotic initiation factor 2α (p-eIF2α) to PP1 leading to increased p-eIF2α levels to activate downstream targets such as ATF4 (activating transcription factor 4) [ 12 ]. Furthermore, Chen, et al demonstrated that SAL rescues anemia in the DDRGK1 F/F knockout mouse model [ 13 ]. These animals have hematopoietic dysfunction including death of hematopoietic stem cells and acute anemia.…”

Salubrinal induces fetal hemoglobin expression via the stress-signaling pathway in human sickle erythroid progenitors and sickle cell disease mice

“…The copyright holder for this preprint this version posted December 13, 2021. ; https://doi.org/10.1101/2021.12.13.472406 doi: bioRxiv preprint rescues anemia in the DDRGK1 F/F knockout mouse model (10). These animals have hematopoietic dysfunction including death of hematopoietic stem and progenitor cells and acute anemia.…”

“…The net result of this action is to interfere with the recruitment of phosphorylated eukaryotic initiation factor 2α (p-eIF2α) to PP1 which increases p-eIF2α levels to activate downstream targets such as ATF4 (activating transcription factor 4) (9). Furthermore, Chen, et al demonstrated that SAL rescues anemia in the DDRGK1 F/F knockout mouse model (10). These animals have hematopoietic dysfunction including death of hematopoietic stem and progenitor cells and acute anemia.…”