Thioredoxin-1 regulates self-renewal and differentiation of murine hematopoietic stem cells through p53 tumor suppressor

Abstract

Background Thioredoxin-1 (TXN1) is one of the major cellular antioxidants in mammals and is involved in a wide range of physiological cellular responses. However, little is known about the roles and the underlying molecular mechanisms of TXN1 in the regulation of hematopoietic stem/progenitor cells (HSPCs). Methods TXN1 conditional knockout mice (ROSA-CreER-TXN1fl/fl) and TXN1fl/fl control mice were used. The mice were treated with tamoxifen and the number and biological functions of HSPCs were measured by flow cytometry, PCR and western blot. Limiting dilution competitive transplantation with sorted HSCs and serial transplantations were performed to assess the effects of TXN1 knockout on HSC self-renewal and long-term reconstitutional capacity. RNA sequencing (RNA-seq) was performed to investigate the downstream molecular pathways of TXN1 deletion in murine HSPCs. CRISPR/Cas9 knockout experiments were performed in vitro in EML murine hematopoietic stem/progenitor cell line to investigate the effects of TXN1 and/or TP53 deletion on cell survival, senescence and colony forming units. TP53 protein degradation assay, CHiP PCR and PGL3 firefly/renilla reporter assay were performed. The effects of TXN1 on various molecular pathways relevant to HSC radiation protection were examined in vitro and in vivo. Results TXN1-TP53 tumor suppressor axis regulates HSPC biological fitness. Deletion of TXN1 in HSPCs using in vivo and in vitro models activates TP53 signaling pathway, and attenuates HSPC capacity to reconstitute hematopoiesis. Furthermore, we found that knocking out of TXN1 renders HSPCs more sensitive to radiation and treatment with recombinant TXN1 promotes the proliferation and expansion of HSPCs. Conclusions Our findings suggest that TXN1-TP53 axis acts as a regulatory mechanism in HSPC biological functions. Additionally, our study demonstrates the clinical potential of TXN1 for enhancing hematopoietic recovery in hematopoietic stem cell transplant and protecting HSPCs from radiation injury.

Enhancing radiotherapy response via intratumoral injection of the TLR9 agonist CpG to stimulate CD8 T cells in an autochthonous mouse model of sarcoma

“…C5 is another cluster of CD8+ T cells that also express high levels of Runx3, Cdca7, Stmn1, Txn1, Ifng, and granzyme-related genes (Figure 3B, Supplementary Figures 3B). These genes are associated with higher immune cell infiltration, as well as proliferative CD8 + T cells (24)(25)(26)(27)(28). However, about 50% of the cells in c5 also express inhibitory receptors and transcription factors such as Pdcd1 and Ctla4, which indicate that some of these cells are transitioning into an exhausted state (16).…”

Insights into the Multifaceted Roles of Thioredoxin-1 System: Exploring Knockout Murine Models

“…To avoid embryonic lethality in Trx-1-deficient animals. Jabbar et al were the first to employ a tamoxifen-inducible model of general Trx-1 knockout [ 70 ]. Upon the induction of Trx-1 depletion, these animals experienced significant deterioration in their health condition and could survive only up to 30 days post-injection of tamoxifen with a mean survival of 15 days.…”

“…A histopathologic assessment revealed no signs of inflammation, necrosis, cell degeneration, or embolism in other organs (e.g., brain, heart, lung, liver, adrenal glands, or kidney). However, some changes in the morphology of the gastrointestinal tract (disorganized intestinal villi and inflammatory cell infiltration) were observed [ 70 ].…”

“…These animals expressed high levels of non-functional human Trx-1 and low levels of wildtype mouse Trx-1 [ 70 ]. Although it is not specifically stated in this article, the animals were seemingly able to survive under normal conditions.…”

Thioredoxin (Trx): A redox target and modulator of cellular senescence and aging-related diseases

“…Trx is a product of two mammalian genes, TXN1 and TXN2, which respectively encode cytoplasmic and mitochondrial Trx isoforms [ 21 , 22 ]. Both isoforms possess a common structure consisting of a 12 kDa protein with an active site characterized by the Cys-Gly-Pro-Cys (CGPC) motif that facilitates the redox reactions of Trx [ 23 ].…”