scholarly journals GIF-2209, an Oxindole Derivative, Accelerates Melanogenesis and Melanosome Secretion via the Modification of Lysosomes in B16F10 Mouse Melanoma Cells

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 177
Author(s):  
Miyu Watanabe ◽  
Kyoka Kawaguchi ◽  
Yusuke Nakamura ◽  
Kyoji Furuta ◽  
Hiroshi Takemori
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Mrna Levels ◽  
Related Protein ◽  
Mouse Melanoma ◽  
Protein Levels ◽  
Independent Mechanism ◽  
Microphthalmia Transcription Factor ◽  
Tyr Gene ◽  
Tyrosinase Related Protein

Melanogenesis and melanosome secretion are regulated by several mechanisms. In this study, we found that the oxindole derivative GIF-2209 accelerated melanogenesis associated with the discrimination in the expression and intracellular distributions of two melanogenic enzymes, tyrosinase (TYR) and tyrosinase-related protein-1 (TYRP-1). GIF-2209 upregulated the expression of TYR via a microphthalmia transcription factor (MITF)-independent mechanism, leading to high expression of protein. In contrast, GIF-2209 did not alter the mRNA levels of TYRP-1 and suppressed its protein levels. GIF-2209 induced the dissociation of TYR from TYRP-1 but did not alter the association between TYR and CD63, a melanosome and lysosome marker. The protein levels of CD63 were also upregulated by GIF-2209. GIF-2209 induced lysosome expansion and redistribution in all areas of the cytosol, accompanied by autophagy acceleration (upregulation of LC3BII protein levels and downregulation of p62 protein levels). In addition, GIF-2209 stimulated the secretion of melanosomes containing high levels of TYR, TYRP-1, and CD63 proteins. The GIF-2209 mediated melanosome secretion was sensitive to the lysosome inhibitor chloroquine. These results suggest that GIF-2209 may activate lysosomal functions with TYR gene expression, while it accelerates melanosome secretion, which finally leads to the depletion of intracellular melanogenic enzyme, especially TYRP-1 protein.

Inhibition of melanogenesis in response to oxidative stress: transient downregulation of melanocyte differentiation markers and possible involvement of microphthalmia transcription factor

2001 ◽  
Vol 114 (12) ◽  
pp. 2335-2344 ◽  
Author(s):  
Celia Jiménez-Cervantes ◽  
María Martínez-Esparza ◽  
Cristina Pérez ◽  
Nicole Daum ◽  
Francisco Solano ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Transcription Factor ◽  
Enzyme Activities ◽  
Mrna Levels ◽  
Melanin Synthesis ◽  
Differentiation Markers ◽  
H2o2 Treatment ◽  
Dopachrome Tautomerase ◽  
Protein Levels ◽  
Microphthalmia Transcription Factor

H2O2 and other reactive oxygen species are key regulators of many intracellular pathways. Within mammalian skin, H2O2 is formed as a byproduct of melanin synthesis, and following u.v. irradiation. We therefore analyzed its effects on melanin synthesis. The activity of the rate-limiting melanogenic enzyme, tyrosinase, decreased in H2O2-treated mouse and human melanoma cells. This inhibition was concentration- and time-dependent in the B16 melanoma model. Maximal inhibition (50-75%) occurred 8-16 hours after a 20 minute exposure to 0.5 mM H2O2. B16 cells withstand this treatment adequately, as shown by a small effect on glutathione levels and a rapid recovery of basal lipid peroxidation levels. Enzyme activities also recovered, beginning to increase 16-20 hours after the treatment. Inhibition of enzyme activities reflected decreased protein levels. mRNAs for tyrosinase, tyrosinase-related protein 1, dopachrome tautomerase, silver protein and melanocortin 1 receptor also decreased after H2O2 treatment, and recovered at different rates. Downregulation of melanocyte differentiation markers mRNAs was preceded by a decrease in microphthalmia transcription factor (Mitf) gene expression, which was quantitatively similar to the decrease achieved using 12-O-tetradecanoylphorbol-13-acetate. Recovery of basal Mitf mRNA levels was also observed clearly before that of tyrosinase. Therefore, oxidative stress may lead to hypopigmentation by mechanisms that include a microphthalmia-dependent downregulation of the melanogenic enzymes.

scholarly journals Uteroplacental insufficiency alters hepatic expression, phosphorylation, and activity of the glucocorticoid receptor in fetal IUGR rats

2005 ◽  
Vol 289 (5) ◽  
pp. R1348-R1353 ◽  
Author(s):  
Mariana Baserga ◽  
Merica A. Hale ◽  
Robert A. McKnight ◽  
Xing Yu ◽  
Christopher W. Callaway ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Glucocorticoid Receptor ◽  
Chromatin Structure ◽  
P53 Protein ◽  
Mrna Levels ◽  
Artery Ligation ◽  
Pregnant Rat ◽  
Hepatic Expression ◽  
Protein Levels

Uteroplacental insufficiency (UPI) induces persistent changes in hepatic gene expression secondary to altered chromatin dynamics in the intrauterine growth- restricted (IUGR) rat liver. The glucocorticoid receptor (GR) is a transcription factor that when activated can induce changes in chromatin structure. To begin the process of identifying pathways by which IUGR affects chromatin structure, we hypothesized that UPI in the rat induces a significant increase in endogenous glucocorticoids (corticosterone) and increases GR expression and activation. To prove our hypothesis, we induced IUGR through bilateral uterine artery ligation of the pregnant rat. At day 1, UPI significantly increased corticosterone levels and was associated with increased total GR mRNA and protein levels in the liver, as well as increased hepatic phosphorylation of GR serine 211. Moreover, cyclin-dependent kinase 2 (CDK2) cyclinA/CDK2 protein levels, which selectively phosphorylate GR serine 211, were also significantly increased. To assess activity of the GR, we measured protein levels of the transcription factor p53 whose levels are downregulated, at least in part, by active GR. In this study, UPI decreased p53 protein and its downstream target Bax mRNA levels. We conclude that UPI in rats affects GR expression and activity in the liver. We speculate that these alterations early in life may contribute to the changes in chromatin structure and gene expression previously described in the IUGR liver.

scholarly journals Calcitriol Suppresses HIF-1 and HIF-2 Transcriptional Activity by Reducing HIF-1/2α Protein Levels via a VDR-Independent Mechanism

Cells ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 2440
Author(s):  
Ioanna-Maria Gkotinakou ◽  
Eleni Kechagia ◽  
Kalliopi Pazaitou-Panayiotou ◽  
Ilias Mylonis ◽  
Panagiotis Liakos ◽  
...  
Keyword(s):  
Vitamin D ◽  
Transcriptional Activity ◽  
Mrna Translation ◽  
Biologically Active ◽  
Mrna Levels ◽  
Akt Signaling Pathway ◽  
Protein Levels ◽  
Anticancer Properties ◽  
Independent Mechanism ◽  
Negative Effect

Hypoxia-inducible transcription factors 1 and 2 (HIFs) are major mediators of cancer development and progression and validated targets for cancer therapy. Although calcitriol, the biologically active metabolite of vitamin D, was attributed with anticancer properties, there is little information on the effect of calcitriol on HIFs and the mechanism underling this activity. Here, we demonstrate the negative effect of calcitriol on HIF-1/2α protein levels and HIF-1/2 transcriptional activity and elucidate the molecular mechanism of calcitriol action. We also reveal that the suppression of vitamin D receptor (VDR) expression by siRNA does not abrogate the negative regulation of HIF-1α and HIF-2α protein levels and HIF-1/2 transcriptional activity by calcitriol, thus testifying that the mechanism of these actions is VDR independent. At the same time, calcitriol significantly reduces the phosphorylation of Akt protein kinase and its downstream targets and suppresses HIF-1/2α protein synthesis by inhibiting HIF1A and EPAS1 (Endothelial PAS domain-containing protein 1) mRNA translation, without affecting their mRNA levels. On the basis of the acquired data, it can be proposed that calcitriol reduces HIF-1α and HIF-2α protein levels and inhibits HIF-1 and HIF-2 transcriptional activity by a VDR-independent, nongenomic mechanism that involves inhibition of PI3K/Akt signaling pathway and suppression of HIF1A and EPAS1 mRNA translation.

Mechanisms of mammalian zinc-regulated gene expression

2008 ◽  
Vol 36 (6) ◽  
pp. 1262-1266 ◽  
Author(s):  
Kelly A. Jackson ◽  
Ruth A. Valentine ◽  
Lisa J. Coneyworth ◽  
John C. Mathers ◽  
Dianne Ford
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Transcriptional Repression ◽  
Mammalian Cells ◽  
Gene Promoter ◽  
Mrna Levels ◽  
Promoter Regions ◽  
Mrna Stabilization ◽  
Transcriptional Regulatory ◽  
Regulated Gene Expression

Mechanisms through which gene expression is regulated by zinc are central to cellular zinc homoeostasis. In this context, evidence for the involvement of zinc dyshomoeostasis in the aetiology of diseases, including Type 2 diabetes, Alzheimer's disease and cancer, highlights the importance of zinc-regulated gene expression. Mechanisms elucidated in bacteria and yeast provide examples of different possible modes of zinc-sensitive gene regulation, involving the zinc-regulated binding of transcriptional activators and repressors to gene promoter regions. A mammalian transcriptional regulatory mechanism that mediates zinc-induced transcriptional up-regulation, involving the transcription factor MTF1 (metal-response element-binding transcription factor 1), has been studied extensively. Gene responses in the opposite direction (reduced mRNA levels in response to increased zinc availability) have been observed in mammalian cells, but a specific transcriptional regulatory process responsible for such a response has yet to be identified. Examples of single zinc-sensitive transcription factors regulating gene expression in opposite directions are emerging. Although zinc-induced transcriptional repression by MTF1 is a possible explanation in some specific instances, such a mechanism cannot account for repression by zinc of all mammalian genes that show this mode of regulation, indicating the existence of as yet uncharacterized mechanisms of zinc-regulated transcription in mammalian cells. In addition, recent findings reveal a role for effects of zinc on mRNA stability in the regulation of specific zinc transporters. Our studies on the regulation of the human gene SLC30A5 (solute carrier 30A5), which codes for the zinc transporter ZnT5, have revealed that this gene provides a model system by which to study both zinc-induced transcriptional down-regulation and zinc-regulated mRNA stabilization.

Synergistic Up-Regulation of Heme Oxygenase-1 in Human Liver by Heme and siRNA to Bach1:Possible Therapeutic Implications.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1633-1633
Author(s):  
Tahereh Ghaziani ◽  
Ying Shan ◽  
Richard W. Lambrecht ◽  
Herbert L. Bonkovsky
Keyword(s):  
Gene Expression ◽  
Heme Oxygenase ◽  
Ischemia Reperfusion Injury ◽  
Tissue Injury ◽  
Ischemia Reperfusion ◽  
Negative Regulator ◽  
Heme Oxygenase 1 ◽  
Significant Finding ◽  
Mrna Levels ◽  
Protein Levels

Abstract Background: Heme oxygenase-1 (HO-1) is an antioxidant defense enzyme that converts toxic heme into antioxidants. HO-1 is strongly up-regulated by its physiologic substrate, heme, which is currently the treatment of choice for acute attacks of porphyria and which may have other therapeutic uses, as well (e.g., for cytoprotection or amelioration of ischemia/reperfusion injury by increasing supply of carbon monoxide, biliverdin, or bilirubin). Up-regulation of HO-1 expression has been associated with increased resistance to tissue injury. Bach1 is a bZip protein which forms heterodimers with small Maf proteins. HO-1 is expressed at higher levels in tissues of Bach1-deficient mice, indicating that Bach1 acts as a negative regulator of the mouse HO-1 gene. The molecular mechanism that confers repression of HO-1 by Bach1, and whether there are similar effects in human cells, has remained elusive. The aim of this study was to assess whether modulation of human hepatic Bach1 expression by siRNA technology influences HO-1 gene expression and whether such gene silencing would enhance the inducing effects of heme on HO-1. Methods: siRNAs targeted 4 different positions of human Bach1 mRNA were designed and synthesized. We transfected Bach1-siRNA (25–200 nM) into Huh-7 cells using Lipofectamine for 24–72 h, after which, cells were treated with or without heme. We quantified HO-1 and Bach1 mRNA and protein levels by quantitative RT-PCR and western blotting, respectively. Effects and specificity of Bach1-siRNA were analyzed and compared with those of non-Bach1 related siRNAs (non-specific control-duplex (NSCD) and LaminB2-siRNA). Results: Bach1-siRNAs (25–200 nM) transfected into Huh-7 cells for 24–72 h significantly reduced Bach1 mRNA and protein levels approximately 80%, compared with non siRNA treated cells. In contrast, transfection with same amounts of NSCD or LaminB2 siRNA did not reduce Bach1 mRNA or protein levels, confirming the specificity of Bach1-siRNA in Huh-7 cells. A significant finding of these studies was the 7-fold up-regulation of the HO-1 gene in Bach1-siRNA transfected cells, compared to cells without Bach1-siRNA or those transfected with NSCD or LaminB2. Bach1, NSCD, and LaminB2 siRNAs had no effect on HO-2 or 5-aminolevulinate synthase-1 mRNA levels (two genes that are not induced by heme). The effects of increasing concentrations of heme (up to 10 μM) in the presence or absence of Bach1-siRNA on the levels of HO-1 mRNA expression are shown in the Figure. For all of the heme concentrations tested, the levels of HO-1 mRNA were greater when Bach1 siRNA was present. Conclusions: Bach1 has a specific and selective effect to repress expression of human hepatic HO-1. Silencing of the Bach1 gene by siRNAs may be a useful method for up-regulating HO-1 gene expression. The combination of intravenous heme and Bach1 silencing may be useful for therapy of acute porphyrias in relapse or other conditions in which up-regulation of HO-1 may be beneficial. (Supported by grants from NIH [DK38825] and Ovation Pharmaceuticals, Inc.) Figure Figure

TPO-Induced miR-150 Down-Regulates c-Myb in Primary Megakaryocytes and a Megakaryocytic Cell Line.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1238-1238 ◽  
Author(s):  
Charlene F. Barroga ◽  
Hang Pham ◽  
Kenneth Kaushansky
Keyword(s):  
Transcription Factor ◽  
Western Blotting ◽  
Luciferase Activity ◽  
Mrna Translation ◽  
Negative Control ◽  
Luciferase Reporter ◽  
Translation Efficiency ◽  
Mrna Levels ◽  
Protein Levels ◽  
Micro Rnas

Abstract Mice harboring c-Myb hypomorphic mutations display enhanced thrombopoiesis because of increased numbers of megakaryocytic progenitors (CFU-MK) and mature megakaryocytes (MK). Thrombopoietin (Tpo), the primary regulator of megakaryopoiesis, induces these same effects, which lead us to hypothesize that Tpo might act, at least in part, through modulation of c-Myb expression. We found using quantitative (Q)-PCR that c-Myb mRNA levels were 13-fold reduced during Tpo-induced MK maturation. Micro RNAs (miRs) are ∼22 nucleotide species that down-regulate gene expression by binding to the 3′ untranslated region (UTR) of specific mRNAs, enhancing mRNA degradation, or by reducing mRNA translation efficiency. We noted that the 3′UTR of c-Myb contains a number of miR target sites, including four that bind miR150; using a specific Q-PCR assay we also found that Tpo increased mir-150 expression to 160% of baseline at 24 hr and 250% at 48 hr in UT7/TPO cells (n=2 experiments). To test if miR150 affects c-Myb expression, we introduced the 3′UTR of c-Myb into a luciferase reporter gene (pCMV-luc-3′UTRcMyb), in which CMV promoter-driven luciferase activity would reflect the stability of the 3′UTR of c-Myb, and allow us to test the effects of miR150 on c-Myb expression in transduced cells; Q-PCR and western blotting were used to simultaneously assess endogenous c-Myb mRNA and protein levels in the cells treated with miR-150 and anti-miR-150, and their respective controls (Ambion, ABI). Co-transfection of UT7/TPO cells with pCMV-luc-3′UTRcMyb and miR-150 significantly down-regulated luciferase activity to 40% of baseline 24 hr following transfection (p = 0.035; n=2 experiments) compared to a miR negative control. Luciferase activity in cells transfected with a control luc plasmid lacking the 3′UTR of c-Myb was not modulated by introduction of miR-150. Q-PCR analysis revealed that endogenous c-Myb mRNA was significantly down-regulated to 60% of baseline upon transfection of miR-150 compared to the negative control (p = 0.043), while the essential megakaryocytic transcription factor, AML1/RUNX1, remained unaltered. Western blotting of these cell lysates revealed that c-Myb protein expression was down-regulated to 30% of baseline (n=3 experiments) following transduction with miR150 but not with the miR negative control. Converse experiments utilizing anti-miRs, which inhibit expression of endogenous miRs, revealed that anti-miR150 significantly upregulated luciferase activity to 180% of baseline compared to an anti-miR-negative control (p=0.003; n=2 experiments). These findings establish that miR-150 down-modulates c-Myb mRNA, and to a greater extent protein levels, suggesting effects on both mRNA stability and protein translation efficiency. And since Tpo affects miR-150 expression, our results also suggest that in addition to direct effects on the survival and growth of MK progenitor cells, mediated by the JAK/STAT, PI3K/Akt and MAPK pathways, Tpo down-modulates c-Myb expression during megakaryopoiesis through the induction of miR150. We are currently ascertaining the in vivo role of miR-150 in Tpo-induced megakaryopoiesis, but these studies already establish that hematopoietic growth factors such as Tpo can influence transcription factor expression through modulation of microRNA species.

Requirement of the E2F3 Transcription Factor for BCR/ABL Leukemogenesis.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 33-33
Author(s):  
Anna M. Eiring ◽  
Paolo Neviani ◽  
Ramasamy Santhanam ◽  
Joshua J. Oaks ◽  
Ji Suk Chang ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Transcription Factor ◽  
Blast Crisis ◽  
Scid Mice ◽  
Myelogenous Leukemia ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Hnrnp A1 ◽  
Protein Levels ◽  
Abl Kinase

Abstract Several RNA binding proteins (RBPs) have been implicated in the progression of chronic myelogenous leukemia (CML) from the indolent chronic phase to the aggressively fatal blast crisis. In the latter phase, expression and function of specific RBPs are altered at transcriptional or post-translational levels by the increased constitutive kinase activity of the BCR/ABL oncoprotein, resulting in enhanced resistance to apoptotic stimuli, growth advantage and differentiation arrest of CD34+ CML blast crisis (CML-BC) progenitors. In the current study, we identified by RIP (RNA immunoprecipitation)-mediated microarray analysis that mRNA encoding the E2F3 transcription factor associates to the BCR/ABL-regulated RBP hnRNP A1. Moreover, RNA electrophoretic mobility shift and UV-crosslinking assays revealed that hnRNP A1 interacts with E2F3 mRNA through a binding site located in the 3’UTR of both human and mouse E2F3 mRNA. Accordingly, E2F3 protein levels were upregulated in BCR/ABL-transformed myeloid precursor cell lines compared to parental cells in a BCR/ABL-kinase- and hnRNP A1 shuttling-dependent manner. In fact, treatment of BCR/ABL-expressing myeloid precursors with the kinase inhibitor Imatinib (2mM, 24 hr) or introduction of a dominant-negative shuttling-deficient hnRNP A1 protein (NLS-A1) markedly reduced E2F3 protein and mRNA levels. Similarly, upregulation of BCR/ABL expression/activity in the doxycycline inducible TonB2.10 cell line resulted in increased E2F3 protein expression. BCR/ABL kinase-dependent induction of E2F3 protein levels was also detected in CML-BCCD34+ compared to CML-CPCD34+ progenitors from paired patient samples and to normal CD34+ bone marrow samples. Importantly, the in vitro clonogenic potential of primary mouse BCR/ABL+ lineage negative (Lin−) progenitors was markedly impaired in BCR/ABL+ E2F3−/− compared to BCR/ABL-transduced E2F3+/+ myeloid progenitors and upon shRNA-mediated downregulation of E2F3 expression (90% inhibition, P<0.001). Furthermore, subcutaneous injection of shE2F3-expressing BCR/ABL+ cells into SCID mice markedly impaired in vivo tumorigenesis (>80% reduction in tumor burden, P<0.01). Accordingly, BCR/ABL leukemogenesis was strongly inhibited in SCID mice intravenously injected with E2F3 shRNA-expressing 32D-BCR/ABL cells and in mice transplanted with BCR/ABL-transduced Lin− bone marrow cells from E2F3−/− mice. Specifically, we demonstrate that reduced or absent levels of E2F3 resulted in dramatically decreased numbers of circulating BCR/ABL+ cells as determined by nested RT-PCR at 4 weeks post-injection (P=0.0001), normal splenic architecture and bone marrow cellularity and the absence of infiltrating myeloid blasts into non-hematopoietic compartments (i.e. liver). By contrast, SCID mice transplanted with vector-transduced 32D-BCR/ABL cells or BCR/ABL+ E2F3+/+ Lin− BM progenitors showed signs of an overt acute leukemia-like process with blast infiltration of hematopoietic and non-hematopoietic organs. Altogether, these data outline the importance of E2F3 expression for BCR/ABL leukemogenesis and characterize a new potential therapeutic target for the treatment of patients with advanced phase CML.

Upregulation of the Anti-Apoptotic Protein, Survivin, in Hematopoietic Cells in Sickle Cell Anemia and Effects of Hydroxyurea Therapy.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1532-1532
Author(s):  
Carolina Lanaro ◽  
Carla Fernanda Franco-Penteado ◽  
Mariana R. B. Mello ◽  
Kleber Yotsumoto Fertrin ◽  
Marcos André C Bezerra ◽  
...  
Keyword(s):  
Gene Expression ◽  
Protein Expression ◽  
Sickle Cell Anemia ◽  
Survivin Expression ◽  
Erythroid Differentiation ◽  
Mrna Levels ◽  
Gene Expressions ◽  
Protein Levels ◽  
Survivin Protein ◽  
Inflammatory State

Abstract Abstract 1532 Poster Board I-555 Survivin (BIRC5) is a member of the inhibitors of apoptosis family implicated in both prevention of cell death and control of mitosis. Although the actions of survivin in control of cancer cell division and apoptosis have been studied, its role in nonneoplastic diseases is not elucidated. Chronic inflammation is associated with STAT-3 upregulation, which can induce survivin production. Sickle cell anemia (SCA) has been characterized as a chronic inflammatory state and growing evidence indicates that inflammatory stress within the microvasculature may play a significant role in the vasoocclusion that is characteristic of SCA. Long-term treatment with hydroxyurea (HU) has been shown to reduce the production of inflammatory cytokines in SCA patients and leukocyte number. Since enhanced survivin expression has been reported in leukocytes under inflammatory conditions, and during hematopoietic cell survival and proliferation, the aim of this study was to investigate changes in survivin levels during erythroid differentiation, and determine expression in neutrophils (NS), mononuclear cells (MC) and red blood cell (RBC) in steady-state SCA patients (n≥10), SCA patients on HU therapy (n≥16), and healthy controls (HC, n≥5). Survivin and STAT-3 gene expression were determined by qRT-PCR analysis in primary human erythroblasts cultures for 7, 10 and 13 days and leukocytes separated from peripheral blood samples. Survivin protein expression was determined by flow cytometry with survivin-specific antibodies. Survivin gene expression was significantly increased during erythroid differentiation, but survivin mRNA levels showed similar patterns between SCA and HC (7d: 0.8±0.1 × 0.7±0.08; 10d: 1.7±0.3 × 1.6±0.2; 13d: 2.2± 0.27 × 1.8±0.19,U.A.,P>0.05,respectively). However, protein levels of survivin in mature RBC (glicophorin A +) was significantly higher in SCA patients compared to HC (41.90± 2.9 × 25.76±1.9, P=0.0006, respectively). BIRC-5 gene expression in MC was significantly higher in SCA patients compared to HC (0.9±0.1 × 0.5±0.2, P=0.04, respectively). Survivin protein levels in MC from SCA was significantly increased to compared to HC (51.7±3.2 × 39.7±1.7, MFI, P=0.01,respectively). Survivin protein levels are elevated in NS of SCA patients compared to HC (28.4±1.6 × 21.9±1.5, MFI, P=0.02,respectively). No significant alterations in the mRNA levels of the gene encoding STAT-3 were found during erythroid differentiation (7d: 1.1±0.04 × 1.1±0.08; 10d: 0.6±0.07 × 0.8±0.08; 13d: 0.6±0.07 × 0.9±0.1, P>0.05,respectively) or MC cells (1.2±0.1 × 1.1± 0.1, P>0.05,respectively) in SCA patients compared to HC. Patients on HU therapy demonstrated lower survivin MC gene expressions and protein levels compared to non-treated patients (0.6±0.3 × 0.9±0.1; 37.9±1.5 × 51.7±3.3, P=0.02; P<0.0001,respectively), but no difference was shown in STAT-3 gene expressions (1.1±0.04 × 1.2 ±0.1, respectively). Survivin protein levels were not significantly different in NS and RBC in patients on HU therapy compared to SCA (27.1±1.8 × 28.4± 1.6; 45.9± 3.2× 41.9± 2.9, MFI, P>0.05, respectively). Our data showed that survivin gene and protein expression are upregulated in MC in SCA patients, independently of STAT-3 expression. In addition, a high protein expression was observed in NS and RBC in these patients. HU therapy was associated with lower survivin expression in MC, but not NS and RBC, indicating that the beneficial effect that HU has on the inflammatory state, may participate in the reduced levels of survivin. In conclusion, the exact importance of survivin in SCA vasooclusion is not clear, but data indicates a high expression of this protein in leukocytes and RBC of SCA patients and may imply a role for this protein in leukocytosis and RBC proliferation in SCA. Disclosures No relevant conflicts of interest to declare.

Sign in / Sign up

Export Citation Format

Share Document