The role of cytokines and transcription factors on the regulation of megakaryocy topoiesis and platelet production are reviewed in this article. Megakaryocytopoiesis involves the proliferation and differentiation of megakaryocytic pro genitor cells into immature megakaryocytes, and the differentiation of immature megakaryocytes to mature megakaryocytes which produce platelets. The former is regulated mainly by thrombopoietin (TPO) and to a lesser degree by other cytokines such as interleukin-1 (IL-1), IL-3 and platelet-derived growth factor (PDGF), the later by TPO and probably IL-6 and IL-11. A number of transcription factors have been implicated in the control of megakaryocyte differentiation. GATA-1, FOG-1 and Fli-1 are essential regulators in early- and mid-stages of megakaryocytopoiesis. NF-E2 regulates late-stage of megakaryocytopoiesis and platelet production. However, the platelet release mechanism is poorly understood. Nitric oxide (NO) may act in the stage of platelet release through induction of apoptosis in megakaryocytes.
Animals ; Cytokines ; physiology ; DNA-Binding Proteins ; physiology ; Erythroid-Specific DNA-Binding Factors ; GATA1 Transcription Factor ; Hematopoiesis ; Humans ; Interleukins ; physiology ; Megakaryocytes ; physiology ; NF-E2 Transcription Factor ; NF-E2 Transcription Factor, p45 Subunit ; Platelet-Derived Growth Factor ; physiology ; Thrombopoiesis ; physiology ; Thrombopoietin ; physiology ; Transcription Factors ; physiology

OBJECTIVETo further characterize the differentiation inducing properties of EDRF1 and demonstrate its functional pathway involved in regulation of globin gene expression.

METHODSBy transfecting EDRF1 sense and antisense constructs into HEL cells, we identified the expression of globin and erythropoietin receptor genes by Northern blot analysis. RT-PCR and EMSA (electrophoresis mobility shift assay) were performed to monitor the expression and DNA-binding activity of erythroid specific transcription factors GATA-1 and NF-E2.

RESULTSIt was shown that when EDRF1 was overexpressed, production of alpha-globin increased. In antisense EDRF1, overexpression of HEL cells, significant loss of alpha-, gamma-globin mRNA synthesis was observed. The transcription of endogenous GATA-1 and NF-E2 mRNA expression were maintained at the same levels compared with control experiments. However, the transcription activity of GATA-1 was severely impaired. Expression of erythropoietin receptor gene was not influenced by EDRF1 gene overexpression.

CONCLUSIONThe results suggested that EDRF1 regulated alpha- and gamma-globin gene synthesis by modulating DNA-binding activity of GATA-1 transcription factor.

Cell Differentiation ; Cells, Cultured ; DNA-Binding Proteins ; genetics ; Erythroid-Specific DNA-Binding Factors ; Erythropoiesis ; physiology ; GATA1 Transcription Factor ; Gene Expression Regulation ; Globins ; genetics ; Humans ; NF-E2 Transcription Factor ; NF-E2 Transcription Factor, p45 Subunit ; RNA, Messenger ; analysis ; Transcription Factors ; genetics ; Up-Regulation

To observe the effects of Panax Notoginosides (PNS) on up-regulation of AP-1 family transcription factors NF-E2, c-jun and c-fos for exploring intracellular signal pathway of PNS in hematopoietic cells, four human hematopoietic cells lines including myeloid HL-60, erythroid K562, megakaryoid CHRF-288 and Meg-01 were incubated in the presence of PNS for 14 days. The nuclear protein of cells were extracted and analyzed by Western blot with antibodies against NF-E2, c-fos and c-jun. Electrophoretic mobility shift assay (EMSA) was performed by using (32)P labeled AP-1 consensus oligonucleotide which contains binding site for NF-E2, c-jun and c-fos. The results showed that the transcription factors NF-E2, c-jun and c-fos of AP-1 family could be induced by PNS. Western blot demonstrated that the nuclear protein of both NF-E2 and c-jun in four cell lines treated by PNS were increased by 1.5-2.5- and 2.0-3.0-fold over untreated cells respectively. The c-fos protein in three cell lines of K562, CHRF-288 and Meg-01 was also elevated by 2.0-3.0-fold respectively, while c-fos protein in HL-60 cells was no detectable difference after PNS treatment. EMSA results in four cell lines indicated that AP-1 binding activity initiated by PNS was apparently elevated to form higher density band of AP-1-DNA complex. In conclusion, the intracellular transcription regulation initiated by PNS was involved in transcription factors NF-E2, c-jun and c-fos of AP-1 family members, which could play an important role in the up-regulation of genes expression related to proliferation and differentiation of hematopoietic cells.
DNA ; metabolism ; DNA-Binding Proteins ; genetics ; Erythroid-Specific DNA-Binding Factors ; Gene Expression Regulation ; drug effects ; Genes, fos ; Genes, jun ; Ginsenosides ; pharmacology ; HL-60 Cells ; Humans ; K562 Cells ; NF-E2 Transcription Factor ; NF-E2 Transcription Factor, p45 Subunit ; Panax ; Transcription Factor AP-1 ; metabolism ; Transcription Factors ; genetics ; Up-Regulation

OBJECTIVETo investigate whether α-hemoglobin stabilizing protein (AHSP), the α-globin-specific molecular chaperone, is regulated by erythroid transcription factor NF-E2.

METHODSWe established the stable cell line with NF-E2p45 (the larger subunit of NF-E2) short hairpin RNA to silence its expression. Western blot, real-time polymerase chain reaction, and chromatin immunoprecipitation (ChIP) analysis were performed to detect the expression of AHSP, the histone modifications at AHSP gene locus, and the binding of GATA-1 at the AHSP promoter with NF-E2p45 deficiency. ChIP was also carried out in dimethyl sulfoxide (DMSO)-induced DS19 cells and estrogen-induced G1E-ER4 cells to examine NF-E2 binding to the AHSP gene locus and its changes during cell erythroid differentiation. Finally, luciferase assay was applied in HeLa cells transfected with AHSP promoter fragments to examine AHSP promoter activity in the presence of exogenous NF-E2p45.

RESULTSWe found that AHSP expression was highly dependent on NF-E2p45. NF-E2 bound to the regions across AHSP gene locus in vivo, and the transcription of AHSP was transactivated by exogenous NF-E2p45. In addition, we observed the decrease of H3K4 trimethylation and GATA-1 occupancy at the AHSP gene locus in NF-E2p45-deficient cells. Restoration of GATA-1 in G1E-ER4 cells in turn led to increased DNA binding of NF-E2p45.

CONCLUSIONNF-E2 may play an important role in AHSP gene regulation, providing new insights into the molecular mechanisms underlying the erythroid-specific expression of AHSP as well as new possibilities for β-thalassemia treatment.

Base Sequence ; Blood Proteins ; genetics ; DNA Primers ; GATA1 Transcription Factor ; physiology ; Gene Expression Regulation ; physiology ; Gene Silencing ; HeLa Cells ; Humans ; Methylation ; Molecular Chaperones ; genetics ; NF-E2 Transcription Factor, p45 Subunit ; physiology ; Promoter Regions, Genetic ; Reverse Transcriptase Polymerase Chain Reaction

OBJECTIVETo explore the mechanism of acupuncture in delaying aging.

METHODSUsing SAMP10 mice and normal control SAMR1 as model and applying RT-PCR and DIG probed Northern blot techniques to observe expression of NF-E2, YB-1, LRG47 genes in whole brain, cortex and hippocampus in the 8-month SAMR1 control group, 8-month SAMP10 control group, 8-month SAMP10 acupuncture group and 8-month SAMP10 non-point acupuncture group.

RESULTSIn the SAMP10 control group, the expression of NF-E2, YB-1 and LRG47 were down-regulated in the whole brain, cortex and hippocampus, and after acupuncture they were up-regulated and tended to normal.

CONCLUSIONAging of the SAMP10 mouse brain is related with expression of NF-E2, YB-1 and LRG47 genes, and acupuncture can regulate the expression of NF-E2, YB-1 and LRG47 genes, improving the functions of erythrocyte series, increasing proliferation of cells and immune function of cells in anti-bacteria, hence anti-aging.

Acupuncture Therapy ; Aging ; metabolism ; Animals ; Brain ; metabolism ; Female ; GTP-Binding Proteins ; genetics ; Gene Expression Regulation ; Male ; Mice ; NF-E2 Transcription Factor, p45 Subunit ; genetics ; RNA, Messenger ; analysis ; Y-Box-Binding Protein 1 ; genetics

BACKGROUND/OBJECTIVES: Anti-inflammatory and antioxidative activities of luteolin and luteolin-7-O-glucoside were compared in galactosamine (GalN)/lipopolysaccharide (LPS)-induced hepatitic ICR mice. MATERIALS/METHODS: Male ICR mice (6 weeks old) were divided into 4 groups: normal control, GalN/LPS, luteolin, and luteolin-7-O-glucoside groups. The latter two groups were administered luteolin or luteolin-7-O-glucoside (50 mg/kg BW) daily by gavage for 3 weeks after which hepatitis was induced by intraperitoneal injection of GalN and LPS (1 g/kg BW and 10 µg/kg BW, respectively). RESULTS: GalN/LPS produced acute hepatic injury by a sharp increase in serum AST, ALT, and TNF-α levels, increases that were ameliorated in the experimental groups. In addition, markedly increased expressions of cyclooxygenase (COX)-2 and its transcription factors, nuclear factor (NF)-κB and activator protein (AP)-1, were also significantly attenuated in the experimental groups. Compared to luteolin-7-O-glucoside, luteolin more potently ameliorated the levels of inflammatory mediators. Phase II enzymes levels and NF-E2 p45-related factor (Nrf)-2 activation that were decreased by GalN/LPS were increased by luteolin and luteolin-7-O-glucoside administration. In addition, compared to luteolin, luteolin-7-O-glucoside acted as a more potent inducer of changes in phase II enzymes. Liver histopathology results were consistent with the mediator and enzyme results. CONCLUSION: Luteolin and luteolin-7-O-glucoside protect against GalN/LPS-induced hepatotoxicity through the regulation of inflammatory mediators and phase II enzymes.
Animals ; Galactosamine ; Hepatitis ; Humans ; Inflammation ; Injections, Intraperitoneal ; Liver ; Luteolin ; Male ; Mice ; Mice, Inbred ICR ; NF-E2-Related Factor 2 ; NF-kappa B ; Prostaglandin-Endoperoxide Synthases ; Transcription Factors

Cancer stem cells (CSCs) are a subset of tumor cells, which are characterized by resistance against chemotherapy and environmental stress, and are known to cause tumor relapse after therapy. A number of molecular mechanisms underlie the chemoresistance of CSCs, including high expression levels of drug efflux transporters. We investigated the role of the antioxidant transcription factor NF-E2-related factor 2 (NRF2) in chemoresistance development, using a CSC-enriched colonosphere system. HCT116 colonospheres were more resistant to doxorubicin-induced cell death and expressed higher levels of drug efflux transporters such as P-glycoprotein (Pgp) and breast cancer resistance protein (BCRP) compared to HCT116 monolayers. Notably, levels of NRF2 and expression of its target genes were substantially elevated in colonospheres, and these increases were linked to doxorubicin resistance. When NRF2 expression was silenced in colonospheres, Pgp and BCRP expression was downregulated, and doxorubicin resistance was diminished. Collectively, these results indicate that NRF2 activation contributes to chemoresistance acquisition in CSC-enriched colonospheres through the upregulation of drug efflux transporters.
Breast Neoplasms ; Cell Death ; Doxorubicin* ; Drug Therapy ; Neoplastic Stem Cells ; NF-E2-Related Factor 2 ; P-Glycoprotein ; Recurrence ; Transcription Factors ; Up-Regulation

Diabetic cardiomyopathy (DCM), as one of the major cardiac complications in diabetic patients, is known to related with oxidative stress that is due to a severe imbalance between reactive oxygen species (ROS) and/or reactive nitrogen species (RNS) generation and their clearance by antioxidant defense systems. Transcription factor nuclear factor NF-E2-related factor 2 (Nrf2) plays an important role in maintaining the oxidative homeostasis by regulating multiple downstream antioxidants. Diabetes may up-regulate several antioxidants in the heart as a compensative mechanism at early stage, but at late stage, diabetes not only generates extra ROS and/or RNS but also impairs antioxidant capacity in the heart, including Nrf2. In an early study, we have established that Nrf2 protect the cardiac cells and heart from high level of glucose in vitro and hyperglycemia in vivo, and in the following study demonstrated the significant down-regulation of cardiac Nrf2 expression in diabetic animals and patients. Using Nrf2-KO mice or Nrf2 inducers, blooming evidence has indicated the important protection by Nrf2 from cardiac pathogenesis in the diabetes. Therefore, this brief review summarizes the status of studies on Nrf2's role in preventing DCM and even other complications, the need for new and safe Nrf2 inducer screening and the precaution for the undesirable side of Nrf2 under certain conditions.
Animals ; Antioxidants ; Diabetic Cardiomyopathies* ; Down-Regulation ; Glucose ; Heart ; Homeostasis ; Humans ; Hyperglycemia ; Mass Screening ; Mice ; NF-E2-Related Factor 2 ; Oxidative Stress ; Reactive Nitrogen Species ; Reactive Oxygen Species ; Transcription Factors

OBJECTIVETo study the expression of lung Krüppel-like transcription factor (KLF2/LKLF) in lung tissues of rats with chronic obstructive pulmonary disease (COPD) and the relationship between KLF2 and NF-E2-related factor 2 (Nrf2), and make further explore the effects of KLF2 on the expression of gamma-glutamylcysteine synthetase (gamma-GCS).

METHODSTwenty-two male SD rats were randomly divided into a COPD group (n = 10) and a normal control group (n = 11). The rat model of COPD established by cigarette smoking and intratracheal instillation of lipopolysaccharide (LPS), and lung tissues were obtained. The expressions of KLF2, Nrf2, gamma-GCS mRNA and protein in lung tissues were measured by immunohistochemistry (IHC), Western blot, in situ hybridization (ISH) and reverse transcription-polymerase chain reaction (RT-PCR). To explore the relationship between KLF2 and Nrf2 protein,we utilize the method of co-immunoprecipitation (CO-IP).

RESULTSIHC and Western blot showed that protein expressions of KLF2, Nrf2, gamma-GCS were higher in the lung tissues from rats with COPD than those in the control groups (all P < 0.05). The levels of KLF2, gamma-GCS mRNA were markedly increased in the COPD group (all P < 0.01) while Nrf2 mRNA expression in COPD group had no significant difference with that in control group ( P > 0.05). CO-IP result showed that KLF2 were obviously present in immunoprecipitates of Nrf2 (P < 0.01) . Linear correlation analysis showed that the level of KLF2 protein was positively correlated with the level of Nrf2 protein (P < 0.05), and KLF2, Nrf2 proteins were positively correlated with gamma-GCS mRNA and protein (all P < 0.05).

CONCLUSIONThe expression of KLF2 is significantly up-regulated in COPD, which maybe up-regulate gamma-GCS mRNA expression by increasing Nrf2 expression and nuclear translocation against oxidative stress.

Animals ; Dipeptides ; metabolism ; Kruppel-Like Transcription Factors ; metabolism ; Lung ; pathology ; physiopathology ; Male ; NF-E2-Related Factor 2 ; metabolism ; Pulmonary Disease, Chronic Obstructive ; metabolism ; pathology ; physiopathology ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the expressions of PPAR-gamma/PGC-1alpha and Nrf2/gamma-GCS-h in lung of guinea pigs with bronchial asthma, and to explore the roles of them.

METHODSForty adult male guinea pigs were randomly divided into 4 groups: the control group (group A), asthmatic group ( group B), dexamethasone group (group C) and rogridone group (group D), 10 guinea pigs in each group. The asthmatic model was established by the ovalbumin challenge method. Expressions of PPAR-gamma/PGC-1alpha and Nrf2/gamma-GCS-h mRNA in lung tissue were assayed by in situ hybridization. Expressions of PPAR-gamma/PGC-1alpha and Nrf2/gamma-GCS-h protein were detected by immunohischemistry and by Western blot.

RESULTSIn situ hybridization showed that the expressions of PPAR-gamma/PGC-1alpha and Nrf2/gamma-GCS-h mRNA in lung tissue were the lowest in group B and the comparison among groups showed statistical significant (all P < 0.01). Immunohistochemistry and Western blot indicated that the value of PPAR-gamma/PGC-1alpha and Nrf2/gamma-GCS-h protein in lung tissue were the lowest in group B, and expressed primarily in nucleus, the differences being statistically significant (all P < 0.01). There was positive correlation between PPAR-gamma and PGC-1. gamma-GCS-h mRNA also positively correlated between PPAR-gamma/PGC-1alpha and Nrf2 in nucleus, and the expression of Nrf2 was also positively correlated with PPAR-gamma/ PGC-1alpha.

CONCLUSIONIn acute asthmatic models induced by ovalbumin, the expressions of PPAR-alpha/PGC-1alpha and Nrf2/gamma-GCS-h were decreased, and PPARgamma/PGC-1alpha could up-regulate the expressions of Nrf2/gamma-GCS-h to increase the antioxidant defense of tissues, thus being implicated that PPARgamma/PGC-1alpha might play important roles in the pathogenesis and prevention of asthma.

Animals ; Asthma ; chemically induced ; physiopathology ; Glutamate-Cysteine Ligase ; genetics ; metabolism ; Guinea Pigs ; Lung ; metabolism ; Male ; NF-E2-Related Factor 2 ; genetics ; metabolism ; Ovalbumin ; PPAR gamma ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Transcription Factors ; genetics ; metabolism