Recovery Of Hematopoietic System Research Articles

The mechanisms for the radioprotective effect of beta-d-glucan on high linear-energy-transfer carbon ion irradiated mice.

S. cerevisiae-derived-beta-d-glucan (S. cerevisiae-BG) is a natural polysaccharide with various biological effects. The present study was to investigate the protective effect of S. cerevisiae-BG on the injury induced by high linear-energy-transfer (LET) carbon ion irradiation and to reveal the protective mechanisms. Female mice were orally administrated with S. cerevisiae-BG before irradiation. 30-day survival of 6 Gy irradiated-mice was monitored. The damage and recovery of hematopoietic system were evaluated after 2 Gy irradiation, cytokines in plasma were detected, transcriptomics of bone marrow mononuclear cells (BMMNCs) were detected and analyzed. The mortality results showed that S. cerevisiae-BG could prolong the survival of mice exposed to 6 Gy. The results of BMMNCs injury analysis showed that S. cerevisiae-BG could reduce the ROS level, mitigate DNA damage and apoptosis. S. cerevisiae-BG increased the plasma radioprotective cytokines level in irradiated mice. Transcriptomics analysis revealed that S. cerevisiae-BG modulated the gene expression in BMMNCs of irradiated mice, 256 genes were significantly up-regulated and 97 genes were significantly down-regulated. Gene function and Gene Ontology analysis indicated the key genes related to hematopoiesis and immunity. Pathway analysis revealed that these up-regulated genes mainly focus on PI3K-Akt pathway and down-regulated genes mainly focus on MAPK pathway. These data contribute to understanding the molecular mechanisms of the radioprotective effect of S. cerevisiae-BG.

Modulation in the expression of p70S6 kinase impairs the engraftment and self-renewal of hematopoietic stem cells

Regulation of hematopoietic stem cell (HSC) function(s) by the mammalian target of rapamycin complex1 (mTORC1) and its upstream regulators has been described before. However, the role of downstream effector of mTORC1, p70S6 kinase (S6K1), in HSC development and functions is unknown. We have assessed the role of S6K1 in HSC development and function under steady-state as well as during recovery of hematopoietic system following myelosuppressive stress using a genetic model of S6K1 knockout mice (S6K1-/-).

Indigowood root extract protects hematopoietic cells, reduces tissue damage and modulates inflammatory cytokines after total-body irradiation: Does Indirubin play a role in radioprotection?

Radix of Isatis indigotica (indigowood root, IR) has been used in traditional medicine for its potential anti-inflammatory effect. The purpose of this study is to investigate the radioprotective effects of radiation caused damages in hematopoietic system and normal tissues in mice. A total of 57 BALB/c mice were randomized into six treatment groups: control, IR treatment (0.195, 0.585 and 1.170 g/kg, p.o. daily), L-glutamine (0.520 g/kg) and sham group. All mice except the sham group were irradiated and then administered for one week. The radioprotective effect on hematopoietic system, serum cytokines, and intestinal toxicity was studied. Protective effects on spleen and thymus are found in IR-treated groups. IR assisted in restoration of leukocytopenia after whole mice irradiation with significant reduction of serum TNF-α, IL-1β, and IL-6. These enhancements of hematopoietic effects are due to an increase in the serum G-CSF concentration in IR treated groups. In histopathological assessment, significant improvement of intestine toxicity is observed in high-dose IR and L-glutamine group. Evidences show that IR has potentials to be a radioprotector, especially in recovery of hematopoietic system, reduction of inflammatory cytokines and intestinal toxicity. Indirubin may play a crucial role, but the underlying mechanism is not very clear and warrants further studies.