拟南芥EARLI1亚家族基因的研究进展

HyPRP家族EARLI1亚家族基因能够应答生物和非生物胁迫因素,是拟南芥防御体系的重要组成部分,它们在个体生长发育过程中也具有调控作用。文中分别介绍了有关AZI1、EARLI1、A T4G12490和AT4G12500等EARLI1亚家族基因功能的研究进展,阐述了它们在低温、盐、外源ABA和真菌病原体等环境和生物胁迫条件下的抗性特征。最后根据EARLI1亚家族基因的研究现状讨论和分析了它们在作物改良中的应用前景。

Effect of adrenomedullin on neuron apoptosis, infarction volume and expression of Egr-1 mRNA after focal ischemia-reperfusion in rats

Objective To observe the influence of adrenomedullin （ADM） on neuron apoptosis, infarction volume of brain, and the expression of early growth response 1 （Egr-1） mRNA in ischemia-reperfusion rats. Methods The arteria cerebri media was tied for 2 h to construct the ischemia model. Infarction volume was detected by triphenltetrazolium chloride （T＇I＇C） staining, neuronal apoptosis and necrosis was detected with terminal deoxynucleotidyl transferase nick labeling （TUNEL） method, and the Egr-1 mRNA expression was examined by in situ hybridization （ISH）. Results Infarction volume after ischemia-reperfusion is （269 ± 20） mm^3. Infarction volume after injection of ADM through different ways are femoral vein （239 ± 17） mm^3 （decreased by 11.2%）, arteria carotis （214 ± 14） mm^3 （by 20.4%） and lateral cerebral ventricle （209 ± 13） mm^3 （by 22.3%）, respectively. The results indicate that injecting ADM through arteria carotis and lateral cerebral ventricle is much more effective than it through femoral vein （P 〈 0.05）. The TUNEL-positive cells in cerebral cortex or hippocampus are few in the sham operation group, but much more in the ischemia-reperfusion group. After being supplied with ADM, especially through arteria carotis interna or lateral cerebral ventricle way, the TUNEL-positive cells decreased obviously. Expression of Egr- 1 mRNA was low in the cerebral cortex of the sham operation group rats, enhanced in the ischemia and reperfusion group rats, and enhanced markedly after treatment with ADM, especially through arteria carotis interna or lateral cerebral ventricle way （P 〈 0.01）. Conclusion Injection of ADM through different ways could alleviate neural dysfunction, decrease neuron apoptosis and brain infarction volume, and increase the expression of Egr- 1 mRNA.

Involvement of MAPK/ERK kinase-ERK pathway in exogenous bFGF-induced Egr-1 binding activity enhancement in anoxia-reoxygenation injured astrocytes

Objective Intravenous administration of basic fibroblast growth factor （bFGF） is effective to reduce the volume of cerebral infract due to ischemia. This study was designed to investigate the molecular mechanism, especially the signal transduction pathways, involved in this protective role of bFGF. Methods Anoxia-reoxygenation treated atrocytes were used to study the role of mitogen-activated protein kinase/extracellular signal-regulated kinase kinase （MAPK/ERK kinase, MEK）-ERK signaling pathway after exogenous bFGF administration by Western blot. Electrophoretic mobile shift assay was used to detect the binding activity of early growth response factor-1 （Egr-1）, an important transcription factor for endogenous bFGF. Results bFGF could protect some signal transduction proteins from the oxygen-derived free radicals induced degradation. ERK1/2 was activated and involved in Egr-1 binding activity enhancement induced by exogenous bFGF. Conclusion MEK-ERK MAPK cascade may be an important signal transduction pathway contributed to bFGF induced enhancement of Egr-1 binding activity in anoxia-reoxygenation injured astrocytes.

Transactivation of the TIEG1 confers growth inhibition of transforming growth factor-β-susceptible hepatocellular carcinoma cells

AIM:To investigate the role of transforming growth factor(TGF)-β-inducible early gene 1(TIEG1) in TGF-β-induced growth inhibition in hepatocellular carcinoma(HCC) cells.METHODS:Human hepatocyte and HCC cell lines with varied susceptibilities to TGF-β1 were tested by methylthiazoletetrazolium(MTT) assay.The expression changes of Smad2,Smad3,Smad4,Smad7,TIEG1 and TIEG2 gene following treatment with TGF-β1 in a TGF-β-sensitive hepatocyte cell line(MIHA),a TGF-β-sensitive hepatoma cell line(Hep3B) and two TGF-β-insensitive hepatoma cell lines(HepG2 and Bel7404) were examined.SiRNA targeting TIEG1 was transfected into Hep3B cells and the sensitivity of cells to TGF-β1 was examined.Overexpression of TIEG1 was induced by lentiviral-mediated transduction in TGF-β1-resistant hepatoma cell lines(Bel7404 and HepG2).MTT assay and 4',6-Diamidino-2-phenylindole staining were used to identify cell viability and apoptosis,respectively.The expression level of stathmin was measured by reverse transcriptase polymerase chain reaction and Western-blotting analysis,and stathmin promoter activity by TIEG1 was monitored by a luciferase reporter gene system.RESULTS:TIEG1 was significantly upregulated by TGF-β1 in the TGF-β1-sensitive HCC cell line,Hep3B,but not in the resistant cell lines.The suppression of TIEG1 by siRNAs decreased the sensitivity of Hep3B cells to TGF-β1,whereas the overexpression of TIEG1 mediated growth inhibition and apoptosis in TGF-β1-resistant HCC cell lines,which resembled those of TGF-β1-sensitive HCC cells treated with TGF-β1.Our data further suggested that stathmin was a direct target of TIEG1,as stathmin was signif icantly downregulated by TIEG1 overexpression,and stathmin promoter activity was inhibited by TIEG1 in a dose-dependent manner.CONCLUSION:Our data suggest that transactivation of TIEG1 conferred growth inhibition of TGF-β-susceptible human HCC cells.

Elevated NKCC1 transporter expression facilitates early post-traumatic brain injury seizures

As a leading cause for morbidity and mortality in young adults,traumatic brain injury（TBI）,along with the poorly understood TBI-related seizures inducing their predispositions,pose a major health and socioeconomic problem in the world（Huang,2013）.

Expression of Egr-1 in the liver of mice following hemorrhagic shock and resuscitation

Objective: To investigate the expression of early growth response gene-1(Egr-1) in the liver following hemorrhagic shock with or without resuscitation(HS or HSR). Methods: Mice were subjected to HS or HSR.Liver expression of Egr-1 mRNA was detected by Northern blotting.DNA binding activity of the Egr-1 protein in liver nuclear extracts(NE) was determined by electrophoretic mobility shift assay(EMSA).Western blot analysis was used to assess the induction of Egr-1 protein in the liver tissue,cytoplasma and NE. Results: Egr-1 mRNA was strongly expressed as early as 1 h after HS,and its level was decreased in the following 2.5 h but still higher than that in 1 h HS group.The Egr-1 DNA binding activity elevated in the liver NE of 2.5 h HS group and 2.5 h HS + 4 h R group,so did the Egr-1 protein in the liver and the liver NE of the same two groups.However,the maximal Egr-1 protein expression was found in the cytoplasma of liver following 2.5 h HS. Conclusion: Our data suggest that both Egr-1 mRNA and protein are strongly elevated and the binding activity of Egr-1 to its cognate DNA site is increased in the liver following HSR,indicating the increases of Egr-1 transcriptional and translational levels.This study provides evidence that Egr-1 gene is activated in the liver during HS and HSR.

Transcription factor EGR-1 inhibits growth of hepatocellular carcinoma and esophageal carcinoma cell lines

AIM: The transcription factor EGR-1 (early growth response gene-1) plays an important role in cell growth, differentiation and development. It has identified that EGR-1 has significant transformation suppression activity in some neoplasms, such as fibrosarcoma, breast carcinoma. This experiment was designed to investigate the role of egr-1 in the cancerous process of hepatocellular carcinoma (HCC) and esophageal carcinoma (EC), and then to appraise the effects of EGR-1 on the growth of these tumor cells. METHODS: Firstly, the transcription and expression of egr-1 in HCC and EC, paracancerous tissues and their normal counterpart parts were detected by in situ hybridization and immunohistochemistry, with normal human breast and mouse brain tissues as positive controls. Egr-1 gene was then transfected into HCC (HHCC, SMMC7721) and EC (ECa109) cell lines in which no egr-1 transcription and expression were present. The cell growth speed, FCM cell cycle, plate clone formation and tumorigenicity in nude mice were observed and the controls were the cell lines transfected with vector only. RESULTS: Little or no egr-1 transcription and expression were detected in HCC, EC and normal liver tissues. The expression of egr-1 were found higher in hepatocellular paracancerous tissue (transcription level P=0.000; expression level P=0.143, probably because fewer in number of cases) and dysplastic tissue of esophageal cancer (transcription level P=0.000; expression level P=0.001). The growth rate of egr-1-transfected HHCC (HCC cell line) cells and ECa109 (EC cell line) cells was much slower than that of the controls. The proportion of S phase cell, clone formation and tumorigenicity were significantly lower than these of the controls' (decreased 45.5% in HHCC cells and 34.1% in ECa109 cells; 46.6% and 41.8%; 80.4% and 72.6% respectively). There were no obvious differences between SMMC7721 (HCC) egr-1-transfected cells and the controls with regard to the above items. CONCLUSION: The decreased expression of egr-1 might play a role in the dysregulation of normal growth in the cancerous process of HCC and EC. Egr-1 gene of transfected HHCC and ECa109 cells showed obvious suppression of the cell growth and malignant phenotypes, but no suppression in SMMC7721 (HCC cell line) cells.

Experimental and clinic-opathologic study on the relationship between transcription factor Egr-1 and esophageal carcinoma

AIM: To observe the growth suppression effect of exogenous introduction of early growth response gene-1 (Egr-1 gene) on esophageal carcinoma tissue as well as on esophageal carcinoma cell line Eca109 and to explore the potential application of Egr-1 gene in gene therapy of tumor. METHODS: Eukaryotic expression vector of PCMV-Egr-1 plasmid was introduced into Eca109 cell line which expressed no Egr-1 protein originally with lipofectamine transfection method. The introduction and expression of PCMV-Egr-1 plasmid into Eca109 cell line was confirmed by G418 selection culture, PCR amplification of neogene contained in the vector, Western blot analysis and immunocytochemical analysis. The cell growth curve, soft agar colony formation rate and tumorigenicity in SCID mice were examined to demonstrate the growth suppression effect of exogenous Egr-1 gene on Eca109 cell line. The Egr-1 mRNA and Egr-1 protein were also detected in 50 surgical specimens of esophageal carcinoma by in situ hybridization and immunohistochemistry. RESULTS: Exogenous Egr-1 gene was introduced successfully into Eca109 cell line and expressed Egr-1 protein stably. The transfected Eca109 cell line grew more slowly than control Eca109 as shown by cell growth curves, the soft agar colony formation rate (4.0% vs 6.9%, P 【 0.01) and the average growth rate of tumor in SCID mice (35.5 +/- 7.6 vs 65.8 +/- 7.6, P 【 0.05). The expression level of Egr-1 mRNA and protein significantly increased in dysplastic epithelia adjacent to cancer rather than in cancer tissues (65.8% vs 20.0% by ISH and 57.9% vs 0.01). CONCLUSION: Exogenous Egr-1 gene shows the strong effect of growth inhibition in Eca109 cell line. Egr-1 in the cancer tissue shows down-regulated expression that supports the inhibited function of Egr-1 in cancer growth and suggests Egr-1 may have an important role in gene therapy of esophageal carcinoma.

Insulin-like growth factor-binding protein-3 inhibits IGF-1-induced proliferation of human hepatocellular carcinoma cells

OBJECTIVE Basic fibroblast growth factor(b FGF)and platelet-derived growth factor(PDGF)produced by hepatocellular carcinoma(HCC)cells are responsible for the cell growth.Accumulating evidence shows that insulin-like growth factor-binding protein-3(IGFBP-3)suppresses HCC cell proliferation in both IGF-dependent and independent manners.The present study is to investigate whether treatment with exogenous IGFBP-3 inhibits bF GF and PDGF production and the cell proliferation of HCC cells.METHODS Cell Counting Kit 8 assay were designed to detect HCC cell proliferation,transcription factor early growth response-1(EGR1)involving in IGFBP-3 regulation of b FGF and PDGF were detected by RT-PCR and Western blot assays.Western blot assay was adopted to detect the IGFBP-3 regulating insulin-like growth factor 1 receptor(IGF-1R)signaling pathway.RESULTS The present study demonstrates that IGFBP-3 suppressed IGF-1-induced b FGF and PDGF expression while it does not affect their expression in the absence of IGF-1.To delineate the underlying mechanism,Western-blot and RT-PCR assays confirmed that the transcription factor early growth response protein 1(EGR1)is involved in IGFBP-3 regulation of b FGF and PDGF.IGFBP-3 inhibition of type 1 insulin-like growth factor receptor(IGF1R),ERK and AKT activation is IGF-1-dependent.Furthermore,transient transfection with constitutively activated AKT or MEK partially blocks the IGFBP-3 inhibition of EGR1,b FGF and PDGF expression.CONCLUSION In conclusion,these findings suggest that IGFBP-3suppresses transcription of EGR1 and its target genes b FGF and PDGF through inhibiting IGF-1-dependent ERK and AKT activation.It demonstrates the importance of IGFBP-3 in the regulation of HCC cell proliferation,suggesting that IGFBP-3 could be a target for the treatment of HCC.

Research progress of the synapsin 2 gene polymorphism in the pathogenesis of schizophrenia

Schizophrenia(SCZ)is the most common serious mental illness with a high disability rate and heavy social and family burdens.At present,there is no clear etiology and pathogenesis of schizophrenia.Studies have shown that the occurrence of schizophrenia may be related to the abnormality of the hypothalamic-pituitary-adrenal(HPA)axis.The LIM-homeobox gene 3(LHXS)and early growth response 1(EGR1)can affect pituitary function.Because the synapsin 2(SYN2)gene polymorphism regulates the activity of LHX3 and EGR1,it may cause the occurrence of schizophrenia.This article will review the possible involvement of SYN2 gene polymorphism in the pathogenesis of schizophrenia via regulating the activity of LHX3 and EGR1,then to afiect the HPA axis.

Early Growth Response Gene-1 Deficiency Interrupts TGFβ1 Signaling Activation and Aggravates Neurodegeneration in Experimental Autoimmune Encephalomyelitis Mice

Early growth response protein 1(Egr-1)triggers the transcription of many genes involved in cell growth,differentiation,synaptic plasticity,and neurogenesis.However,its mechanism in neuronal survival and degeneration is still poorly understood.This study demonstrated that Egr-1 was down-regulated at mRNA and protein levels in the central nervous system(CNS)of experimental autoimmune encephalomyelitis(EAE)mice.Egr-1 knockout exacerbated EAE progression in mice,as shown by increased disease severity and incidence;it also aggravated neuronal apoptosis,which was associated with weakened activation of the BDNF/TGFβ1/MAPK/Akt signaling pathways in the CNS of EAE mice.Consistently,Egr-1 siRNA promoted apoptosis but mitigated the activation of BDNF/TGFβ1/MAPK/Akt signaling in SH-SY5Y cells.Our results revealed that Egr-1 is a crucial regulator of neuronal survival in EAE by regulating TGFβ1-mediated signaling activation,implicating the important role of Egr-1 in the pathogenesis of multiple sclerosis as a potential novel therapy target.

Heme oxygenase 1-mediated ferroptosis in Kupffer cells initiates liver injury during heat stroke

With the escalating prevalence of global heat waves,heat stroke has become a prominent health concern,leading to substantial liver damage.Unlike other forms of liver injury,heat strokeinduced damage is characterized by heat cytotoxicity and heightened inflammation,directly contributing to elevated mortality rates.While clinical assessments have identified elevated bilirubin levels as indicative of Kupffer cell dysfunction,their specific correlation with heat stroke liver injury remains unclear.Our hypothesis proposes the involvement of Kupffer cell ferroptosis during heat stroke,initiating IL-1bmediated inflammation.Using single-cell RNA sequencing of murine macrophages,a distinct and highly susceptible Kupffer cell subtype,Clec4Ft/CD206t,emerged,with heme oxygenase 1(HMOX-1)playing a pivotal role.Mechanistically,heat-induced HMOX-1,regulated by early growth response factor 1,mediated ferroptosis in Kupffer cells,specifically in the Clec4F t/CD206 t subtype(KC2),activating phosphatidylinositol 4-kinase beta and promoting PI4P production.This cascade triggered NLRP3 inflammasome activation and maturation of IL-1b.These findings underscore the critical role of targeted therapy against HMOX-1 in ferroptosis within Kupffer cells,particularly in Clec4F t/CD206 t KCs.Such an approach has the potential to mitigate inflammation and alleviate acute liver injury in the context of heat stroke,offering a promising avenue for future therapeutic interventions.

MiR-551b-5p Contributes to Pathogenesis of Vein Graft Failure via Upregulating Early Growth Response-1 Expression

Background： Vein graft failure （VGF） is a serious complication of coronary artery bypass graft, although the mechanism remains unclear. The study aimed to investigate the effects of microRNAs （miRNAs） on the endothelial dysfunction involved in VGF. Methods： Human umbilical vein endothelial cells （HUVECs） were subjected to mechanical stretch stimulation to induce endothelial dysfunction. Genome-wide transcriptome profiling was performed using the Human miRNA OneArray＂ V4 （PhalanxBio Inc., San Diego, USA）. The miRNA-messenger RNA （mRNA） network was investigated using gene ontology and Kyoto Encyclopedia of Genes and Genomes. The miR-55 1b-5p mimic and inhibitor were applied to regulate miR-55 lb-5p expression in the HUVECs. The 5-ethynyl-2＇-deoxyuridine assay, polymerase chain reaction （PCR）, and Western blotting （WB） were used to assess HUVECs proliferation, mRNA expression, and protein expression, respectively. The vein graft model was established in early growth response （Egr）-I knockout （KO） mice and wide-type （WT） C57BL/6J mice for pathological and immunohistochemical analysis. Endothelial cells isolated from the veins of WT and Egr-1 KO mice were subjected to mechanical stretch stimulation; PCR and WB were conducted to confirm the regulatory effect of Egr- 1 on Intercellular adhesion molecule （loam-1）. One-way analysis of variance and independent t-test were performed for data analysis. Results： Thirty-eight rniRNAs were differentially expressed in HUVECs after mechanical stretch stimulation. The bioinforrnatics analysis revealed that Egr-1 might be involved in VGF and was a potential target gene of miR-551b-5p. The mechanical stretch stimulation increased miR-55 1b-5p expression by 2.93 ± 0.08 told （t= 3.07, P 〈 0.05）, compared with the normal HUVECs. Transfection with the miR-551b-5p mimic or inhibitor increased expression of miR-551b-5p by 793.1 ± 171.6 fold （t = 13.84, P 〈 0.001） or decreased by 26.3% ± 2.4% （t= 26.39, P 〈 0.05） in the HUVECs, respectively. HUVECs proliferation and EGR-I mRNA expression were significantly suppressed by inhibiting miR-551b-5p expression （P 〈 0.05）. The lumens of the vein grafts in the Egr-1 KO mice were wider than that in the WT mice. lcam-I expression was suppressed significantly in the Egr-1 KO vein grafts （P 〈 0.05）. Conclusions： Increased miR-55 1b-5p expression leads to endothelial dysfunction by upregulating Egr-1 expression. EGR-1 KO can improve the function of a grafted vein through suppressing loam-1.

Lipocalin-2-Mediated Insufficient Oligodendrocyte Progenitor Cell Remyelination for White Matter Injury After Subarachnoid Hemorrhage via SCL22A17 Receptor/Early Growth Response Protein 1 Signaling

Insufficient remyelination due to impaired oligodendrocyte precursor cell(OPC)differentiation and maturation is strongly associated with irreversible white matter injury(WMI)and neurological deficits.We analyzed whole transcriptome expression to elucidate the potential role and underlying mechanism of action of lipocalin-2(LCN2)in OPC differentiation and WMI and identified the receptor SCL22A17 and downstream transcription factor early growth response protein 1(EGR1)as the key signals contributing to LCN2-mediated insufficient OPC remyelination.In LCN-knockdown and OPC EGR1 conditional-knockout mice,we discovered enhanced OPC differentiation in developing and injured white matter(WM);consistent with this,the specific inactivation of LCN2/SCl22A17/EGR1 signaling promoted remyelination and neurological recovery in both atypical,acute WMI due to subarachnoid hemorrhage and typical,chronic WMI due to multiple sclerosis.This potentially represents a novel strategy to enhance differentiation and remyelination in patients with white matter injury.

Arabidopsis small ubiquitin-related modifier protease ASP1 positively regulates abscisic acid signaling during early seedling development~~

The small ubiquitin-related modifier （SUMO） modification plays an important role in the regulation of abscisic acid （ABA） signaling, but the function of the SUMO protease, in ABA signaling, remains largely unknown. Here, we show that the SUMO protease, ASPI positively regulates ABA signaling. Mutations in ASPI resulted in an ABA-insensitive phenotype, during early seedling develop- ment. Wild-type ASP1 successfully rescued, whereas an ASPI mutant （C577S）, defective in SUMO protease activity, failed to rescue, the ABA-insensitive phenotype of asp1-1. Expression of ABI5 and MYB3o target genes was attenuated in asp^-I and our genetic analyses revealed that ASP1 may function upstream of ABI5 and MYB3o.