Prognostic significance of oligodendrocyte transcription factor 2 expression in glioma patients:A systematic review and metaanalys

BACKGROUND Gliomas are the most common primary central nervous system neoplasm.Despite recent advances in the diagnosis and treatment of gliomas,patient prognosis remains dismal.Therefore,it is imperative to identify novel diagnostic biomarkers and therapeutic targets of glioma to effectively improve treatment outcomes.AIM To investigate the association between oligodendrocyte transcription factor 2(Olig2)expression and the outcomes of glioma patients.METHODS The PubMed,Embase,Cochrane Library,and China National Knowledge Infrastructure databases were searched for studies(published up to October 2023)that investigated the relationship between Olig2 expression and prognosis of glioma patients.The quality of the studies was assessed using the Newcastle Ottawa Scale.Data analyses were performed using Stata Version 12.0 software.RESULTS A total of 1205 glioma patients from six studies were included in the metaanalysis.High Olig2 expression was associated with better outcomes in glioma patients[hazard ratio(HR):0.81;95%(confidence interval)CI:0.51-1.27;P=0.000].Furthermore,the results of subgroup meta-analysis showed that high expression of Olig2 was associated with poor overall survival in European patients(HR:1.34;95%CI:0.79-2.27)and better prognosis in Asian patients(HR:0.43;95%CI:0.22-0.84).The sensitivity analysis showed that no single study had a significant effect on pooled HR,and there was also no indication of publication bias according to the Egger’s and Begger’s P value test or funnel plot test.CONCLUSION High Olig2 expression may have a positive impact on the prognosis of glioma patients,and should be investigated further as a prognostic biomarker and therapeutic target for glioma.

β-Arrestin-2 enhances endoplasmic reticulum stress-induced glomerular endothelial cell injury by activating transcription factor 6 in diabetic nephropathy

BACKGROUND Glomerular endothelial cell(GENC)injury is a characteristic of early-stage diabetic nephropathy(DN),and the investigation of potential therapeutic targets for preventing GENC injury is of clinical importance.AIM To investigate the role ofβ-arrestin-2 in GENCs under DN conditions.METHODS Eight-week-old C57BL/6J mice were intraperitoneally injected with streptozotocin to induce DN.GENCs were transfected with plasmids containing siRNA-β-arrestin-2,shRNA-activating transcription factor 6(ATF6),pCDNA-β-arrestin-2,or pCDNA-ATF6.Additionally,adeno-associated virus(AAV)containing shRNA-β-arrestin-2 was administered via a tail vein injection in DN mice.RESULTS The upregulation ofβ-arrestin-2 was observed in patients with DN as well as in GENCs from DN mice.Knockdown ofβ-arrestin-2 reduced apoptosis in high glucose-treated GENCs,which was reversed by the overexpression of ATF6.Moreover,overexpression ofβ-arrestin-2 Led to the activation of endoplasmic reticulum(ER)stress and the apoptosis of GENCs which could be mitigated by silencing of ATF6.Furthermore,knockdown ofβ-arrestin-2 by the administration of AAV-shRNA-β-arrestin-2 alleviated renal injury in DN mice.CONCLUSION Knockdown ofβ-arrestin-2 prevents GENC apoptosis by inhibiting ATF6-mediated ER stress in vivo and in vitro.Consequently,β-arrestin-2 may represent a promising therapeutic target for the clinical management of patients with DN.

Oligodendrocyte transcription factor 1 overexpression promotes oligodendrocyte transcription factor 2 expression in the brains of neonatal rats exposed to hypoxia

To examine the expression profiles of oligodendrocyte transcription factors 1 and 2 （Oligl and Olig2） and the interaction between these two proteins, Oligl was transfected into the lateral ventricles of neonatal rats subjected to hypoxia. Immunohistochemistry demonstrated that Olig2 was expressed throughout the nuclei in the brain, and expression increased at 3 days following hypoxia and was higher than levels at 7 days following Ad5-Oligl transfection. Western blot revealed that Oligl and Olig2 expression increased in Oligl-transfected brain cells 3 days after hypoxia, but Oligl and Olig2 expression decreased at 7 days. These results indicate that Oligl overexpression enhances Olig2 expression in brain tissues of hypoxia rats.

WWP2 promotes degradation of transcription factor OCT4 in human embryonic stem cells

POU transcription factor OCT4 not only plays an essential role in maintaining the pluripotent and self-renewing state of embryonic stem （ES） cells but also acts as a cell fate determinant through a gene dosage effect. However, the molecular mechanisms that control the intracellular OCT4 protein level remain elusive. Here, we report that human WWP2, an E3 ubiquitin （Ub）-protein ligase, interacts with OCT4 specifically through its WW domain and enhances Ub modification of OCT4 both in vitro and in vivo. We first demonstrated that endogenous OCT4 in hu- man ES cells can be post-translationally modified by Ub. Furthermore, we found that WWP2 promoted degradation of OCT4 through the 26S proteasome in a dosage-dependent manner, and the active site cysteine residue of WWP2 was required for both its enzymatic activity and proteolytic effect on OCT4. Remarkably, our data show that the en- dogenous OCT4 protein level was significantly elevated when WWP2 expression was downregulated by specific RNA interference （RNAi）, suggesting that WWP2 is an important regulator for maintaining a proper OCT4 protein level in human ES cells. Moreover, northern blot analysis showed that the WWP2 transcript was widely present in diverse human tissues/organs and highly expressed in undifferentiated human ES cells. However, its expression level was quickly decreased after human ES cells differentiated, indicating that WWP2 expression might be developmentally regulated. Our findings demonstrate that WWP2 is an important regulator of the OCT4 protein level in human ES cells.

Mapping of liver-enriched transcription factors in the human intestine

AIM: To investigate the gene expression pattern of hepatocyte nuclear factor 6 (HNF6) and other liverenriched transcription factors in various segments of the human intestine to better understand the differentiation of the gut epithelium. METHODS: Samples of healthy duodenum and jejunum were obtained from patients with pancreatic cancer whereas ileum and colon was obtained from patients undergoing right or left hemicolectomy or (recto)sigmoid or rectal resection. All surgical specimens were subjected to histopathology. Excised tissue was shock-frozen and analyzed for gene expression of liver-enriched transcription factors by semiquantitative reverse transcription polymerase chain and compared to the human colon carcinoma cell line Caco-2. Protein expression of major liver-enriched transcription factors was determined by Western blotting while the DNA binding of HNF6 was investigated by electromobility shift assays. RESULTS: The gene expression patterning of liverenriched transcription factors differed in the various segments of the human intestine with HNF6 gene expression being most abundant in the duodenum (P < 0.05) whereas expression of the zinc finger protein GATA4 and of the HNF6 target gene ALDH3A1 was most abundant in the jejunum (P < 0.05). Likewise, expression of FOXA2 and the splice variants 2 and 4 of HNF4α were most abundantly expressed in the jejunum (P < 0.05). Essentially, expression of transcription factors declined from the duodenum towards the colon with the most abundant expression in the jejunum and less in the ileum. The expression of HNF6 and of genes targeted by this factor, i.e. neurogenin 3 (NGN3) was most abundant in the jejunum followed by the ileum and the colon while DNA binding activity of HNF4α and of NGN3 was conf irmed by electromobility shift assays to an optimized probe. Furthermore, Western blotting provided evidence of the expression of several liver-enriched transcription factors in cultures of colon epithelial cells, albeit at different levels. CONCLUSION: We describe significant local and segmental differences in the expression of liver-enriched transcription factors in the human intestine which impact epithelial cell biology of the gut.

Transcription factor-based gene therapy to treat glioblastoma through direct neuronal conversion

Objective:Glioblastoma(GBM)is the most prevalent and aggressive adult primary cancer in the central nervous system.Therapeutic approaches for GBM treatment are under intense investigation,including the use of emerging immunotherapies.Here,we propose an alternative approach to treat GBM through reprogramming proliferative GBM cells into non-proliferative neurons.Methods:Retroviruses were used to target highly proliferative human GBM cells through overexpression of neural transcription factors.Immunostaining,electrophysiological recording,and bulk RNA-seq were performed to investigate the mechanisms underlying the neuronal conversion of human GBM cells.An in vivo intracranial xenograft mouse model was used to examine the neuronal conversion of human GBM cells.Results:We report efficient neuronal conversion from human GBM cells by overexpressing single neural transcription factor Neurogenic differentiation 1(Neuro D1),Neurogenin-2(Neurog2),or Achaete-scute homolog 1(Ascl1).Subtype characterization showed that the majority of Neurog2-and Neuro D1-converted neurons were glutamatergic,while Ascl1 favored GABAergic neuron generation.The GBM cell-converted neurons not only showed pan-neuronal markers but also exhibited neuron-specific electrophysiological activities.Transcriptome analyses revealed that neuronal genes were activated in glioma cells after overexpression of neural transcription factors,and different signaling pathways were activated by different neural transcription factors.Importantly,the neuronal conversion of GBM cells was accompanied by significant inhibition of GBM cell proliferation in both in vitro and in vivo models.Conclusions:These results suggest that GBM cells can be reprogrammed into different subtypes of neurons,leading to a potential alternative approach to treat brain tumors using in vivo cell conversion technology.

Genome-Wide Identification of Zn_(2)Cys_(6 ) Class Fungal-Specific Transcription Factors(ZnFTFs)and Functional Analysis of UvZnFTFI in Ustilaginoidea virens

Transcription factors(TFs)orchestrate the regulation of cellular gene expression and thereby determine cell functionality.In this study,we analyzed the distribution of TFs containing domains,which named as ZnFTFs,both in ascomycete and basidiomycete fungi.We found that ZnFTFs were widely distributed in these fungal species,but there was more expansion of the ZnFTF class in Ascomycota than Basidiomycota.We identified 40 ZnFTFs in Ustilaginoidea virens,and demonstrated the involvement of UvZnFTF1 in vegetative growth,conidiation,pigment biosynthesis and pathogenicity.RNA-Seq analysis suggested that UvZnFTF1 may regulate different nutrient metabolism pathways,the production of secondary metabolites,and the expression of pathogen-host interaction genes and secreted protein-encodi ng genes.Analysis of the distributi on of differe nt fungal TFs in U.virens further dem on strated that UvZnFTFs make up a large TF family and may play essential biological roles in U.virens.

Upregulation of miR-34c after silencing E2F transcription factor 1 inhibits paclitaxel combined with cisplatin resistance in gastric cancer cells

BACKGROUND MicroRNA 34c(miR-34c)has been reported to be associated with malignant types of cancer,however,it remains unknown whether miR-34c is involved in chemoresistance in gastric cancer(GC).AIM To investigate the effect of miR-34c and its upstream transcription factor E2F1 on paclitaxel combined with cisplatin resistance in GC cells.METHODS Paired GC tissues and adjacent normal tissues were randomly sampled from 74 GC patients.miR-34c and E2F1 were detected by real-time quantitative PCR(qPCR)and Western blot.In addition,the drug resistance of GC cells to paclitaxel and cisplatin was induced by concentration gradient increasing methods,and changes in miR-34c and E2F1 during this process were measured.Furthermore,E2F1 and miR-34c overexpression or underexpression vectors were constructed and transfected into drug-resistant GC cells.MTT was employed to test the sensitivity of cells to paclitaxel combined with cisplatin,qPCR was adopted to detect the expression of miR-34c,Western blot was applied to detect the expression levels of E2F1,drug resistance-related proteins and apoptosis-related proteins,and flow cytometry was used for the determination of cell apoptosis and cell cycle status.RESULTS E2F1 was overexpressed while miR-34c was underexpressed in GC.After inducing GC cells to be resistant to paclitaxel and cisplatin,E2F1 expression increased while miR-34c expression decreased.Both silencing E2F1 and overexpressing miR-34c could increase the sensitivity of drug-resistant GC cells to paclitaxel combined with cisplatin,promote cell apoptosis and inhibit cell proliferation.Among which,silencing E2F1 could reduce the expression of drug resistance-related proteins and apoptosis-related proteins,while over-expression of miR-34c could upregulate the expression of apoptosis-related proteins without affecting the expression of MDR-1,MRP and other drug resistance-related proteins.Rescue experiments demonstrated that inhibiting miR-34c could significantly weaken the sensitization of drug resistant cells,and Si E2F1 to paclitaxel combined with cisplatin.CONCLUSION E2F1 inhibits miR-34c to promote the proliferation of GC cells and enhance the resistance to paclitaxel combined with cisplatin,and silencing E2F1 is conducive to improving the efficacy of paclitaxel combined with cisplatin in GC cells.

The R2R3-MYB transcription factor GaPC controls petal coloration in cotton

Although a few cases of genetic epistasis in plants have been reported, the combined analysis of genetically phenotypic segregation and the related molecular mechanism remains rarely studied. Here, we have identified a gene(named GaPC) controlling petal coloration in Gossypium arboreum and following a heritable recessive epistatic genetic model. Petal coloration is controlled by a single dominant gene,GaPC. A loss-of-function mutation of GaPC leads to a recessive gene Gapc that masks the phenotype of other color genes and shows recessive epistatic interactions. Map-based cloning showed that GaPC encodes an R2R3-MYB transcription factor. A 4814-bp long terminal repeat retrotransposon insertion at the second exon led to GaPC loss of function and disabled petal coloration. GaPC controlled petal coloration by regulating the anthocyanin and flavone biosynthesis pathways. Expression of core genes in the phenylpropanoid and anthocyanin pathways was higher in colored than in white petals. Petal color was conferred by flavonoids and anthocyanins, with red and yellow petals rich in anthocyanin and flavonol glycosides, respectively. This study provides new insight on molecular mechanism of recessive epistasis,also has potential breeding value by engineering GaPC to develop colored petals or fibers for multifunctional utilization of cotton.

Long non-coding RNA CDKN2B-AS1 promotes hepatocellular carcinoma progression via E2F transcription factor 1/G protein subunit alpha Z axis

BACKGROUND A series of long non-coding RNAs(lncRNAs)have been reported to play a crucial role in cancer biology.Some previous studies report that lncRNA CDKN2B-AS1 is involved in some human malignancies.However,its role in hepatocellular carcinoma(HCC)has not been fully deciphered.AIM To decipher the role of CDKN2B-AS1 in the progression of HCC.METHODS CDKN2B-AS1 expression in HCC was detected by quantitative real-time polymerase chain reaction.The malignant phenotypes of Li-7 and SNU-182 cells were detected by the CCK-8 method,EdU method,and flow cytometry,respectively.RNA immunoprecipitation was executed to confirm the interaction between CDKN2B-AS1 and E2F transcription factor 1(E2F1).Luciferase reporter assay and chromatin immunoprecipitation were performed to verify the binding of E2F1 to the promoter of G protein subunit alpha Z(GNAZ).E2F1 and GNAZ were detected by western blot in HCC cells.RESULTS In HCC tissues,CDKN2B-AS1 was upregulated.Depletion of CDKN2B-AS1 inhibited the proliferation of HCC cells,and the depletion of CDKN2B-AS1 also induced cell cycle arrest and apoptosis.CDKN2B-AS1 could interact with E2F1.Depletion of CDKN2B-AS1 inhibited the binding of E2F1 to the GNAZ promoter region.Overexpression of E2F1 reversed the biological effects of depletion of CDKN2B-AS1 on the malignant behaviors of HCC cells.CONCLUSION CDKN2B-AS1 recruits E2F1 to facilitate GNAZ transcription to promote HCC progression.

MicroRNA-584-5p/RUNX family transcription factor 2 axis mediates hypoxia-induced osteogenic differentiation of periosteal stem cells

BACKGROUND The hypoxic environment during bone healing is important in regulating the differentiation of periosteal stem cells(PSCs)into osteoblasts or chondrocytes;however,the underlying mechanisms remain unclear.AIM To determine the effect of hypoxia on PSCs,and the expression of microRNA-584-5p(miR-584-5p)and RUNX family transcription factor 2(RUNX2)in PSCs was modulated to explore the impact of the miR-584-5p/RUNX2 axis on hypoxiainduced osteogenic differentiation of PSCs.METHODS In this study,we isolated primary mouse PSCs and stimulated them with hypoxia,and the characteristics and functional genes related to PSC osteogenic differentiation were assessed.Constructs expressing miR-584-5p and RUNX2 were established to determine PSC osteogenic differentiation.RESULTS Hypoxic stimulation induced PSC osteogenic differentiation and significantly increased calcified nodules,intracellular calcium ion levels,and alkaline phosphatase(ALP)activity in PSCs.Osteogenic differentiation-related factors such as RUNX2,bone morphogenetic protein 2,hypoxia-inducible factor 1-alpha,and ALP were upregulated;in contrast,miR-584-5p was downregulated in these cells.Furthermore,upregulation of miR-584-5p significantly inhibited RUNX2 expression and hypoxia-induced PSC osteogenic differentiation.RUNX2 was the target gene of miR-584-5p,antagonizing miR-584-5p inhibition in hypoxia-induced PSC osteogenic differentiation.CONCLUSION Our study showed that the interaction of miR-584-5p and RUNX2 could mediate PSC osteogenic differentiation induced by hypoxia.

Identification,Structure Analyses and Expression Pattern of the ERF Transcription Factor Family in Coffea arabica

Members of the ERF Family of Transcription Factors play an important role in plant development and gene expression that regulates responses to biotic and abiotic stress.This work identified 36 ERF family genes in Coffea arabica within the AP2/ERF full domain,using the EST-based genomic resource of the Brazilian Coffee Genome Project.The ERF family genes were classified into nine of the ten existing groups through phylogenetic analysis of the deduced amino acid sequences and comparison with the sequences of the ERF family genes in Arabidopsis.In addition to the AP2 domain,other conserved domains were identified,typical of members of each group.The in silico analysis and expression profiling showed high levels of expression for libraries derived from tissues of fruits,leaves and flowers as well as for libraries subjected to water stress.These results suggest the participation of the ERF family genes of C.arabica in distinct biological functions,such as control of development,maturation,and responses to water stress.The results of this work imply in the selection of promising genes for further functional characterizations that will provide a better understanding of the complex regulatory networks related to plant development and responses to stress,opening up opportunities for coffee breeding programs.

<i>Wrinkled</i>1 (WRI1) Homologs, AP2-Type Transcription Factors Involving Master Regulation of Seed Storage Oil Synthesis in Castor Bean (<i>Ricinus communis</i>L.)

Among APETALA2 (AP2)-type plant specific transcription factor family, WRINKLED1 (WRI1), has appeared to be a master gene transcriptionally regulating a set of carbon metabolism- and fatty acid synthesis (FAS)-related genes responsible for seed specific triacylglycerols (TAGs) storage in oil plants. B3 type transcription factors, such as ABI3 and FUS3, are known to be involved in seed development, such as seed storage protein synthesis and maturation. Based on the recent whole genome sequence data of castor bean (Ricinus communis L.), putative WRI1 homologs (RcWRI1, RcWRI2) specifically expressed in castor bean seed have been identified by comparing organ specific expression profiles among seed development-related transcription factors, seed storage specific genes (Ricin, RcOleosin) and a set of FAS genes including genes for sucrose synthase (RcSUS2), biotin carboxyl carrier protein (a subunit of acetyl-CoA carboxylase, RcBCCP2) and ketoacyl-acyl carrier protein synthase (RcKAS1). Immunoreactive signals with WRI1, FUS3 and ABI5-related polypeptides were also detected in seed specifically, consistent with the expression profiles of seed development-related genes. The WRI1 binding consensus sites, [CnTnG](n)(7)[CG], designated as the AW-box, were found at the promoter region of RcBCCP2 and RcKAS1. Thus, RcWRI1 possibly play a pivotal role in seed specific TAGs storage during seed development by directly activating FAS -related genes.

Expression of Activated Epidermal Growth Factor Receptor and Transcription Factor E2F in Condyloma Accuminata

Objective: To study the expression of activated epi-dermal growth factor receptor (EGFR) and transcrip-tion factor E2F (E2F) in Condyloma Accuminata(CA)patients. Methods: Immunofluorescent techniques were usedto investigate the expression of activated EGFR andE2F in CA patients. Results: The expression of activated EGFR on themembrane of epithelial cells in CA lesions was sig-nificantly greater compared to expression levers inthe control group (P<0.01). Moreover, the co-expres-sion of activated EGFR and E2F was significantly in-creased compared to the control group (P<0.01). Conclusion: Our observations suggest that the in-crease in activated EGFR expression may stimulatehyperplasia in CA patients through the activation oftranscription factor E2F.

The Transcription Factors GATA-1 and GATA-4 Have Opposite Effects on DNA Expression Driven by an Amh Promoter

An Amh promoter driving expression of a reporter gene (d2EGFP) has been used to analyze the role of two specific promoter transcription factor binding elements. In addition a downstream (3’) enhancer (DE) was also investigated. The transcription factors GATA-1 and GATA-4 had opposite effects, the former being incremental and the latter decremental. The quantitative balance between these two factors may provide a degree of control over the level of gene expression.

Correlation research of Runt-related transcription factor 2 with proliferation genes, tumor suppressor genes and angiogenesis molecules in colon cancer lesions

Objective: To investigate the correlation of Runt-related transcription factor 2 (RunX2) with proliferation genes, tumor suppressor genes and angiogenesis molecules in colon cancer lesions. Methods: A total of 90 patients with primary colon cancer were enrolled in colon cancer group, 68 patients with benign colon polyps were enrolled in colon polyps group, the differences in the expression levels of RunX2, proliferation genes, tumor suppressor genes and angiogenesis molecules in the two groups of lesions were compared, and Pearson test was further used to evaluate the correlation of RunX2 expression level with proliferation gene, tumor suppressor gene and angiogenesis molecule expression levels in colon cancer tissues. Results: RunX2 mRNA expression level in the lesions of colon cancer group was higher than that of colon polyps group. Proliferation genes GTPBP4, HOXB7, ZNF331, ADAM17 and HSP60 mRNA expression levels in the lesions of colon cancer group were higher than those of colon polyps group;tumor suppressor genes ATF3, FOXN3, OTUD1 and NDRG2 mRNA expression levels were lower than those of colon polyps group;angiogenesis molecules Musashi 1, NF-κB, RegⅣ and STAT3 mRNA expression levels were higher than those of colon polyps group. RunX2 mRNA expression level in the colon cancer lesions was directly correlated with the expression levels of the above proliferation genes, tumor suppressor genes and angiogenesis molecules. Conclusion: RunX2 expression is abnormally high in colon cancer lesions, the specific expression level is positively correlated with cancer cell proliferation activity and angiogenesis activity, and it is an important molecular target that can lead to the occurrence and development of colon cancer.

Cyanidine-3-O-Galactoside Enriched <i>Aronia melanocarpa</i>Extract Inhibits Adipogenesis and Lipogenesis via Down-Regulation of Adipogenic Transcription Factors and Their Target Genes in 3T3-L1 Cells

Aronia melamocarpa (AM) is a rich source of anthocyanins, which are known to help prevent obesity. The cyanidine-3-O-galactoside enriched AM extract (AM-Ex) containing more cyanidine-3-O-galactoside than conventional AM extract was recently developed. The objective of this study was to examine the effect of AM-Ex on adipogenesis and its action mechanisms in vitro using 3T3-L1 adipocytes. To examine the anti-obesity effect of AM-Ex, 3T3-L1 cells were induced adipocyte differentiation and incubated with various concentration of AM-Ex. Lipid accumulation, cellular triglyceride content, mRNA expression of transcription factors and adipogenic genes were analyzed. Treatment with 100 - 400 μg/mL of AM-Ex resulted in a dose-dependent decrease in adipocyte differentiation and triglyceride accumulation. mRNA expression of adipogenic transcription factors, such as peroxisome proliferator-activated receptor gamma, CCAAT/enhancer binding protein α, sterol regulatory element-binding protein 1 were decreased. The level of gene expression of adipogenesis and lipogenesis-related genes, such as adipocyte protein 2, lipoprotein lipase, acetyl-CoA carboxylase, ATP-citrate lyase and fatty acid synthase were decreased. These results suggest that AM-Ex alleviated risk factors related to obesity by modulating multiple pathways associated with adipogenesis.

New insights into the functions and localization of the homeotic gene CDX2 in gastric cancer

Gastric cancer is one of the most frequent cancers, and it ranks the third most common cancer in China. The most recently caudal-related homeobox transcription factor 2 (CDX2) is expressed in a large number of human gastrointestinal cancers. In addition, gastric epithelial cell mutations in CDX2 result in tumor promotion, which is characterized by cellular drug resistance and a high proclivity for developing cancer. A series of publications over the past years suggests a mechanism by which CDX2 overexpression results in multidrug resistance. CDX2 appears to forward control regenerating IV and the multidrug resistance 1 expression signaling pathway for regulation of cell drug resistance.

Decline in the expression of IL-2 after trauma and changes in the nuclear transcription factors NFAT and AP-1

OBJECTIVE: To investigate whether the decrease in expression of interleukin-2 (IL-2) after trauma is associated with changes in DNA binding activity of nuclear factor of activated T cells (NFAT) and activator protein-1 (AP-1). METHODS: Mice with closed impact injury with fracture in both hind limbs were adopted as the trauma model. Spleen lymphocytes were isolated from traumatized mice and stimulated with Con-A. Culture supernatants were assayed for IL-2 activity, and total RNA was extracted from spleen lymphocytes and assayed for IL-2 mRNA. DNA binding activity of NFAT and AP-1 were measured by electrophoretic mobility shift assay (EMSA). The expression of c-Fos, c-Jun and JunB proteins was determined by the Western blot analysis. RESULTS: DNA binding activity of NFAT and AP-1 gradually decreased to a minimum of 41% and 49%, respectively, of the control on the 4th day after injury, which was closely followed by the decline in IL-2 activity and IL-2 mRNA. A decrease in the expression of c-Fos on the 1st and 4th day after trauma had no significant effect on c-Jun expression; the increase in expression of JunB was only on the 1st day after injury. CONCLUSION: Decreased IL-2 expression is, at least in part, due to a decline in the activation of NFAT and AP-1 in traumatized mice. The decline in DNA binding activity of NFAT and AP-1 is partly due to a trauma-induced block in the expression of c-Fos.

The root-knot nematode effectorMi2G02 hijacks a host plant trihelix transcription factor to promote nematode parasitism

Root-knot nematodes(RKNs)cause huge agricultural losses every year.They secrete a repertoire of effectors to facilitate parasitism through the induction of plant-derived giant feeding cells,which serve as their sole source of nutrients.However,the mode of action of these effectors and their targeted host pro-teins remain largely unknown.In this study,we investigated the role of the effector Mi2G02 in Meloidogyne incognita parasitism.Host-derived Mi2G02 RNA interference in Arabidopsis thaliana affected giant cell development,whereas ectopic expression of Mi2G02 promoted root growth and increased plant sus-ceptibility to M.incognita.We used various combinations of approaches to study the specific interactions between Mi2G02 and A.thaliana GT-3a,a trihelix transcription factor.GT-3a knockout in A.thaliana affected feeding-site development,resulting in production of fewer egg masses,whereas GT-3a overex-pression in A.thaliana increased susceptibility to M.incognita and also root growth.Moreover,we demon-strated that Mi2G02 plays a role in maintaining GT-3a protein stabilization by inhibiting the 26S proteasome-dependent pathway,leading to suppression of TOZ and RAD23C expression and thus promoting nematode parasitism.This work enhances our understanding of how a pathogen effector manipulates the role and regulation of a transcription factor by interfering with a proteolysis pathway to reprogram gene expression for development of nematode feeding cells.