Intracellular iron status as a hallmark of mammalian cell susceptibility to oxidative stress: a study of L5178Y mouse lymphoma cell lines differentially sensitive to H2O2

Blood ◽  
2000 ◽  
Vol 95 (9) ◽  
pp. 2960-2966 ◽  
Author(s):  
Pawel Lipiński ◽  
Jean-Claude Drapier ◽  
Leonor Oliveira ◽  
Hanna Retmańska ◽  
Barbara Sochanowicz ◽  
...  

The redox properties of iron make this metal a key participant in oxygen-mediated toxicity. Accordingly, L5178Y (LY) mouse lymphoma cell lines, which display a unique inverse cross-sensitivity to ionizing radiation (IR) and hydrogen peroxide (H2O2), are a suitable model for the study of possible differences in the constitutive control of intracellular iron availability. We report here that the level of iron in the cytosolic labile iron pool (LIP), ie, potentially active in the Fenton reaction, is more than 3-fold higher in IR-resistant, H2O2-sensitive (LY-R) cells than in IR-sensitive, H2O2-resistant (LY-S) cells. This difference is associated with markedly greater content of ferritin H-subunits (H-Ft) in LY-S than in LY-R cells. Our results show that different expression of H-Ft in LY cells is a consequence of an up-regulation of H-Ft mRNA in the LY-S mutant cell line. In contrast, posttranscriptional control of iron metabolism mediated by iron-responsive element–iron regulatory proteins (IRPs) interaction is similar in the 2 cell lines, although IRP1 protein levels in iron-rich LY-R cells are twice those in iron-deficient LY-S cells. In showing that LY cell lines exhibit 2 different patterns of intracellular iron regulation, our results highlight both the role of high LIP in the establishment of pro-oxidant status in mammalian cells and the antioxidant role of ferritin.

1998 ◽  
Vol 45 (3) ◽  
pp. 701-704 ◽  
Author(s):  
M Kruszewski ◽  
T Iwaneńko

The role of nuclear proteins in protection of DNA against ionizing radiation and their contribution to the radiation sensitivity was examined by an alkaline version of comet assay in two L5178Y (LY) mouse lymphoma cell lines differing in sensitivity to ionizing radiation. LY-S cells are twice more sensitive to ionizing radiation than LY-R cells (D0 values of survival curves are 0.5 Gy and 1 Gy, respectively). Sequential removal of nuclear proteins by extraction with NaCl of different concentrations increased the X-ray induced DNA damage in LY-R nucleoids. In contrast, in the radiation sensitive LY-S cell line, depletion of nuclear proteins practically did not affect DNA damage. Although there is no doubt that the main cause of LYS cells' sensitivity to ionizing radiation is a defect in the repair of double-strand breaks, our data support the concept that nuclear matrix organisation may contribute to the cellular susceptibility to DNA damaging agents.


2015 ◽  
Vol 98 (1) ◽  
pp. 119-131 ◽  
Author(s):  
Sabine Wolter ◽  
Christina Kloth ◽  
Marina Golombek ◽  
Fanni Dittmar ◽  
Lisa Försterling ◽  
...  

2000 ◽  
Vol 68 (4) ◽  
pp. 2077-2081 ◽  
Author(s):  
Belinda S. Hall ◽  
Miercio A. Pereira

ABSTRACT Expression of functional transforming growth factor β (TGF-β) receptors (TβR) is required for the invasion of mammalian cells by the protozoan parasite Trypanosoma cruzi. However, the precise role of this host cell signaling complex in T. cruzi infection is unknown. To investigate the role of the TGF-β signaling pathway, infection levels were studied in the mink lung epithelial cell lines JD1, JM2, and JM3. These cells express inducible mutant TβR1 proteins that cannot induce growth arrest in response to TGF-β but still transmit the signal for TGF-β-dependent gene expression. In the absence of mutant receptor expression, trypomastigotes invaded the cells at a low level. Induction of the mutant receptors caused an increase in infection in all three cell lines, showing that the requirement for TGF-β signaling at invasion can be divorced from TGF-β-induced growth arrest. TGF-β pretreatment of mink lung cells expressing wild-type TβR1 caused a marked enhancement of infection, but no enhancement was seen in JD1, JM2, and JM3 cells, showing that the ability of TGF-β to stimulate infection is associated with growth arrest. Likewise, expression of SMAD7 or SMAD2SA, inhibitors of TGF-β signaling, did not block infection by T. cruzi but did block the enhancement of infection by TGF-β. Taken together, these results show that there is a dual role for TGF-β signaling in T. cruzi infection. The initial invasion of the host cell is independent of both TGF-β-dependent gene expression and growth arrest, but TGF-β stimulation of infection requires a fully functional TGF-β signaling pathway.


Blood ◽  
2009 ◽  
Vol 113 (7) ◽  
pp. 1555-1563 ◽  
Author(s):  
Samira Lakhal ◽  
Nick P. Talbot ◽  
Alexi Crosby ◽  
Chantal Stoepker ◽  
Alain R. M. Townsend ◽  
...  

Abstract Growth differentiation factor 15 (GDF15) is a divergent member of the transforming growth factor–β superfamily and has been identified in different contexts as a hypoxia-inducible gene product and as a molecule involved in hepcidin regulation. The biology of iron and oxygen is closely related, and known regulatory pathways involving hypoxia-inducible factor (HIF) and iron-regulatory proteins (IRPs) are responsive to both these stimuli. We therefore sought to characterize the regulation of GDF15 by iron and oxygen and to define the involvement or otherwise of HIF and IRP pathways. Here we show that GDF15 is strongly up-regulated by stimuli that deplete cells of iron and that this response is specifically antagonized by the reprovision of iron. GDF15 exhibits greater sensitivity to iron depletion than hypoxia, and responses to hypoxia and iron depletion are independent of HIF and IRP activation, suggesting a novel mechanism of regulation. We also report significant induction of serum GDF15 in iron-deficient subjects and after administration of an iron chelator to normal subjects. These findings indicate that GDF15 can be induced by pathophysiologic changes in iron availability, raising important questions about the mechanism of regulation and its role in iron homeostasis.


1991 ◽  
Vol 4 (5) ◽  
pp. 354-357 ◽  
Author(s):  
Akira Murakami ◽  
Harutaka Tanaka

1995 ◽  
Vol 347 (3-4) ◽  
pp. 105-115 ◽  
Author(s):  
Li-Shi Zhang ◽  
Masamitsu Honma ◽  
Makoto Hayahshi ◽  
Takayoshi Suzuki ◽  
Atsuko Matsuoka ◽  
...  

Blood ◽  
1998 ◽  
Vol 91 (3) ◽  
pp. 1059-1066 ◽  
Author(s):  
Stefania Recalcati ◽  
Donatella Taramelli ◽  
Dario Conte ◽  
Gaetano Cairo

Cytokine-treated macrophages represent a useful model to unravel the molecular basis of reticuloendothelial (RE) iron retention in inflammatory conditions. In the present study, we showed that stimulation of murine macrophage J774 cells with interferon (IFN)-γ/lipopolysaccharide (LPS) resulted in a nitric oxide-dependent modulation of the activity of iron regulatory proteins (IRP)-1 and 2, cytoplasmic proteins which, binding to RNA motifs called iron responsive elements (IRE), control ferritin translation. Stimulation with cytokines caused a small increase of IRP-1 activity and a strong reduction of IRP-2 activity accompanied by increased ferritin synthesis and accumulation. Cytokines induced only a minor increase of H chain ferritin mRNA, thus indicating that IRP-2–mediated posttranscriptional regulation plays a major role in the control of ferritin expression. This was confirmed by direct demonstration that the translational repression function of IRP was impaired in stimulated cells. In fact, translation in cell-free extracts of a reporter transcript under the control of an IRE sequence was repressed less efficiently by IRP-containing lysates from cytokine-treated cells than by lysates from control cells. Our findings throw light on the role of IRP-2 showing that: (1) this protein responds to a stimulus in opposite fashion to IRP-1; (2) when abundantly expressed, as in J774 cells, IRP-2 is sufficient to regulate intracellular iron metabolism in living cells; and (3) by allowing increased ferritin synthesis, IRP-2 may play a role in the regulation of iron homeostasis in RE cells during inflammation.


2017 ◽  
Vol 35 (4_suppl) ◽  
pp. 39-39
Author(s):  
Il Kim

39 Background: We previously describedthat the NDPK-A(nucleoside diphosphate kinase A) contributes variably to the migration of cancer cell. To investigate the role of the NDPK-A in gastric lymphoma, we evaluated the expression of NDPK-A in two different cancer cell lines of the same gastric lymphoma patient. Methods: The primary cell line of gastric lymphoma, RF-1, was cultured from the primary gastric lymphoma site, and the other cell line RF-48 was metastasized to the peritoneum of the same patient after 6 months. We have generated stable gastric lymphoma transfectants, pIRES-NDPKA-GFP-neo, that constitutively over-express transfected and vector form of NDPK-A, in addition to a reporter, green fluorescent protein(GFP). The transfected gastric lymphoma cell migration assay was performed 24-well modified chemotaxis chambers with FluroBloc membrane. Results: In regard to the migration rate of the gastric lymphoma cell lines, RF-1 vector was 75.8±7.5%, RF-1 transfected was 54.4±12.3%, RF-48 vector was 84.7±15.4%, RF-48 transfected type was 62.3±9.2%, RF-48 migrated better than RF-1, and the vector type migrated better than the transfected type. NDPK-A was presented more in RF-1 than RF-48, and presented more in the transfected type than the vector type, and concerning the migration rate, RF-48 migrated better than RF-1, and the vector type migrated better than the transfected type. Conclusions: Concerning NM 23-H1 gene encodes the NDPK-A in gastric lymphomas, more abundant was NDPK-A, poorer was migration, and thus it played a role of the suppressor of migration. Our analysis of pooled data found that NDPK-A acts as a migration suppressor in gastric lymphoma.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2381-2381
Author(s):  
Kanutte Huse ◽  
Marianne B. Eide ◽  
Christian Kersten ◽  
Erlend B. Smeland ◽  
June H. Myklebust

Abstract Bone morphogenetic proteins (BMPs) belong to the TGF-β superfamily, and mediate their effects mainly through the Smad signalling pathway. Whereas TGF-β is well established as one of the most potent negative regulators in hematopoietic cells, the role of BMPs remains more elusive. We have previously shown that BMP-6 inhibits the growth of naïve and memory human B cells. As high BMP-6 mRNA expression is associated with poor outcome in diffuse large B cell lymphoma (DLBCL; Rosenwald et al, N Engl J Med 2002), we hypothesized that resistance towards BMP-induced growth inhibition is a possible mechanism for lymphomagenesis. In the current study, 7 B cell lymphoma cell lines (representing Burkitt lymphoma (BL) and DLBCL) and tumour material from lymphoma patients were investigated to unravel the role of BMPs in lymphomas. We analyzed the expression of BMP receptors by FACS analysis, and found variable expression of the BMP receptor type I (Alk2, Alk3 and Alk6) and type II (BMP RII, Activin RIIA and RIIB) among the cell lines and in primary lymphoma cells, suggesting variable binding of BMPs. We next investigated the effect of BMP-2, BMP-4, BMP-6 and BMP-7 on proliferation and survival of B lymphoma cell lines, and found 2 of 7 cell lines to be resistant towards BMP-2 and BMP-4 induced growth inhibition. In contrast, 4 of 7 and 7 of 7 cell lines were resistant to BMP-6 and BMP-7 induced growth inhibition, respectively. In Sudhl6 cells that were highly sensitive to BMP-2 and BMP-6 induced apoptosis and inhibition of proliferation, we demonstrated that the cytokines IL-10, CD40 Ligand and BLyS were able to counteract the negative effects induced by BMPs, while IL-2 and IL-4 were not. On the contrary, both BMP-2 and BMP-6 greatly increased anti-IgM activation induced apoptosis. In resistant lymphoma cells, the BMPs were not able to induce detectable levels or induced low levels of phosphorylated SMAD1/5/8 compared to sensitive cell lines. Low or no increase in phosphorylation of SMAD1/5/8 induced by BMPs could only partly be explained by low/ undetectable expression of BMP receptors. Hence, upregulation of inhibitory Smads (Smad6, Smad7) or mutations in receptors or Smads represent other possible mechanisms for resistance to BMPs in lymphomas, and this is currently under investigation. We also investigated if the lymphoma cells produced BMPs themselves and found that 5 of 7 cell lines and 3 of 5 primary lymphomas produced significant amounts of BMP-7. Some lymphoma cells also had detectable levels of BMP-4 and BMP-6. Our findings that lymphoma cells are resistant towards BMP-7 and to some degree BMP-6 induced growth inhibition, whereas they produce these cytokines, suggest that resistance towards BMP induced signalling in B cell lymphomas can contribute to increased tumour growth.


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