Effect and Involved Mechanism of RSL3-induced Ferroptosis in Acute Leukemia Cells MOLM13 and Drug-resistant Cell Lines / 中国实验血液学杂志

OBJECTIVE@#To investigate the effect and involved mechanism of RSL3 on ferroptosis action in acute leukemia cells MOLM13 and its drug-resistant cells.@*METHODS@#After MOLM13 treated with RSL3, CCK-8 assay was performed to detect cell viability, flow cytometry was used to detect the reactive oxygen species (ROS) level of the cells, RT-qPCR and Western blot were used to detect the expression of glutathione peroxidase 4 (GPX4). After MOLM13/IDA and MOLM13/Ara-C, the drug-resistant cell lines were constructed, the ferroptosis induced by RSL3 was observed. Bone marrow samples were collected from patients with acute monocytic leukemia. RT-qPCR and Western blot were performed to detect the expression of related genes and proteins involved in ferroptosis pathway.@*RESULTS@#RSL3 significantly inhibited the cell viability of MOLM13 and increased the intracellular ROS level, which were partially reversed by ferrostatin-1. The mRNA and protein expression of GPX4 decreased in MOLM13 treated with RSL3. RSL3 inhibited the viability of MOLM13/IDA and MOLM13/Ara-C cells more strongly than that of non-drug resistant cells, also increased the intracellular ROS level . The cytotoxic effects were partially reversed by ferrostatin-1. The mRNA and protein expressions of GPX4 in MOLM13/IDA and MOLM13/Ara-C cells were higher than those in non-drug resistant cells. The mRNA and protein levels of GPX4 in bone marrow of relapsed/refractory acute mononuclear leukemia patients were higher than those of ordinary acute mononuclear leukemia patients.@*CONCLUSION@#RSL3 can induce non-drug resistant cells MOLM13 ferroptosis by inhibiting GPX4 activity. MOLM13/IDA and MOLM13/Ara-C are more sensitive to RSL3 compared with non-drug resistant cells MOLM13, which may be caused by the differences in GPX4 expression. The expressions of GPX4 mRNA and protein in relapsed/refractory acute mononuclear leukemia are higher than those in ordinary acute mononuclear leukemia.

Effects of Iron Overload on the Apoptosis and Function of Splenic CD8+ T Cells in Mice / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the effects of iron overload on apoptosis and function of splenic CD8+ T cells in mice.</p><p><b>METHODS</b>Forty C57BL/6 mice were randomly divided into control groups, Iron overload (IO), IO+NAC and IO+DFX groups. The iron overload model was established by intraperitoneal injection of iron dextran, and saline was injected as the control. The levels of intracellular reactive oxygen species (ROS) and labile iron pool (LIP) were analyzed by measuring the mean fluorescence intensity (MFI) of 2-7 dichlorofluorescein (DCF) or calcein. The ratio of CD8+ T cells and the levels of IFN-γ, TNF-α, Granzyme-B, and perforin in CD8+ T cells were detected by flow cytometry. The CD8+ T cell apoptosis was determined by flow cytometry with Annexin V/PI double staining. Real-time PCR was used to detect the expression of IFN-γ, TNF-α, Granzyme-B, perforin, BCL-2, and bax at mRNA level in CD8+ T cells.</p><p><b>RESULTS</b>Iron overload was found by spleen iron staining and flow cytometry. The level of intracellular ROS in iron overload (IO) groups was higher than that of the control groups (P<0.01). The percentage of CD8+ T cells in spleen from mice with IO was lower than that in control groups (P<0.05). The expression of IFN-γ and Granzyme-B in CD8+ T cells in IO group were lower than that in control group, the expression of IFN-γ and Granzyme-B at mRNA level in CD8+ T cells was lower than that of control group (P<0.05). CD8+ T cell apoptosis in iron overload group was significantly higher than that in control groups (P<0.01); the expression of BCL-2 at mRNA level was lower than that in control group, but the expression of BAX at mRNA level was higher than that in control group (P<0.05). These effects could be reversed after treating iron-overloaded mice with DFX or NAC.</p><p><b>CONCLUSION</b>Iron overload can inhibit the ratio of CD8+ T cells of splenic cells in mice, decrease the expression of IFN-γ, Granzyme-B, increase the apoptosis of CD3+ CD8+/CD8-. These effects may be regulated through increasing the intracellular ROS level, and can be partially reversed after treating iron-overloaded mice with DFX or NAC.</p>

Establishment of an mouse model of iron-overload and its impact on bone marrow hematopoiesis / 中国医学科学院学报

<p><b>OBJECTIVE</b>To establish a mouse model of iron overload by intraperitoneal injection of iron dextran and investigate the impact of iron overload on bone marrow hematopoiesis.</p><p><b>METHODS</b>A total of 40 C57BL/6 mice were divided into control group, low-dose iron group (12.5 mg/ml), middle-dose iron group (25 mg/ml), and high-dose iron group (50 mg/ml). The control group received normal saline (0.2 ml), and the rest were injected with intraperitoneal iron dextran every three days for six weeks. Iron overload was confirmed by observing the bone marrow, hepatic, and splenic iron deposits and the bone marrow labile iron pool. In addition, peripheral blood and bone marrow mononuclear cells were counted and the hematopoietic function was assessed.</p><p><b>RESULTS</b>Iron deposits in bone marrow, liver, and spleen were markedly increased in the mouse models. Bone marrow iron was deposited mostly within the matrix with no significant difference in expression of labile iron pool.Compared with control group, the ability of hematopoietic colony-forming in three interventional groups were decreased significantly (P<0.05). Bone marrow mononuclear cells counts showed no significant difference. The amounts of peripheral blood cells (white blood cells, red blood cells, platelets, and hemoglobin) in different iron groups showed no significant difference among these groups;although the platelets were decreased slightly in low-dose iron group [(780.7±39.60)×10(9)/L], middle dose iron group [(676.2±21.43)×10(9)/L], and high-dose iron group [(587.3±19.67)×10(9)/L] when compared with the control group [(926.0±28.23)×10(9)/L], there was no significant difference(P>0.05).</p><p><b>CONCLUSIONS</b>The iron-overloaded mouse model was successfully established by intraperitoneal administration of iron dextran. Iron overload can damage the hepatic, splenic, and bone marrow hematopoietic function, although no significant difference was observed in peripheral blood count.</p>

Reactive oxygen species and fibrosis in tissues and organs - review / 中国实验血液学杂志

Reactive oxygen species (ROS) is a kind of molecules derived by oxygen in the metabolic process of aerobic cells, which mainly includes superoxide, hydroxyl radicals, alkoxyl, hydrogen peroxide, hypochlorous acid, ozone, etc. They can destroy the structure and function of cells through the damage of biological macromolecules such as DNA, proteins and the lipid peroxidation. ROS also can regulate the proliferation, differentiation and apoptosis of cells through several signaling pathways and participate in fibrogenesis of many organs including hepatic and pulmonary fibrosis. Recent study shows that ROS might have an important effect on the forming of myelofibrosis. Consequently, ROS plays a significant role in the fibrogenesis of tissues and organs. In this review, the relevance between ROS and common tissues and organs fibrosis is summarized.