With the constant change of global climate, plants are often affected by multiple abiotic stresses such as heat stress, drought stress, cold stress and saline-alkali stress. Heat shock transcription factors (HSFs) are a class of transcription factors widely existing in plants to respond to a variety of abiotic stresses. In this article, we review and summarize the structure, signal regulation mechanism of HSFs and some research in plants like Arabidopsis thaliana, tomato, rice and soybean, to provide reference for further elucidating the role of HSFs in the stress regulation network.
Arabidopsis/metabolism* ; Droughts ; Gene Expression Regulation, Plant ; Heat Shock Transcription Factors/genetics* ; Plant Proteins/genetics* ; Stress, Physiological ; Transcription Factors/metabolism*

OBJECTIVE: To observe the effect of Krüppel-like factor 4 (KLF4) overexpression on heat stress-induced apoptosis of Raw264.7 macrophages. METHODS: The fragment containing full length mouse KLF4 cDNA coding sequence was inserted into the pcDNA3.1 vector and Raw264.7 macrophages were transfected with pcDNA3.1-KLF4 plasmids using lipofectamine.The expression of KLF4 was examined by Western blot in the Raw264.7 macrophages stably transfected with pcDNA3.1- KLF4 plasmids. Raw264.7 cells transfected with pcDNA3.1 and pcDNA3.1-KLF4 were exposed to heat stress (42 degrees C) for 1h and recovered at 37 degrees C for 12h. Flow cytometry, Hoechest 33258 staining assay, and DNA ladder assays were performed to assess the apoptosis. RESULTS: The KLF4 overexpressed Raw264.7 macrophages were established. After the heat stress, flow cytometry showed that apoptotic cells increased significantly in KLF4 overexpressed cells compared with the vector control; Hoechest 33258 staining was characterized with classical changes including apoptotic body, and nuclear condensation. Agarose gel electrophoresis showed that "DNA ladder" could be observed clearly. CONCLUSION KLF4 overexpression can increase heat stress-induced apoptosis of Raw264.7 macrophages.
Animals ; Apoptosis ; genetics ; Cell Line ; Genetic Vectors ; Heat-Shock Response ; Kruppel-Like Transcription Factors ; genetics ; Macrophages ; cytology ; Mice ; Plasmids ; Transfection

AIMTry to clarify the effects of HSF1 gene on the constitutively expressed alphaBC.

METHODSTo investigate the levels of constitutively expressed alphaB-Crystallin (alphaBC) in hsf1 knockout (hsf1 -/-) and hsf1 wild type (hsf1 +/+) mice myocardium by Western blot and immunohistochemistry.

RESULTSThe alphaBC levels in hsf1 -/- and hsf1 +/+ were 68.42% +/- 4.16%, 100% +/- 7.58%, respectively (P < 0.05, cytosolic fraction), and 20.53% +/- 1.01%, 37.55% +/- 1.91%, respectively (P < 0.05, pellet fraction). The alphaBC signals decreased significantly in hsf1 -/- myocardium compared with hsf1 +/+ myocardium stained with fluorescence immunohistochemistry.

CONCLUSIONhsf1 is the important, but not the only factor, which mediates the constitutively expressed alphaBC.

Animals ; DNA-Binding Proteins ; genetics ; Female ; Genotype ; Heat Shock Transcription Factors ; Male ; Mice ; Mice, Knockout ; Myocardium ; metabolism ; Transcription Factors ; genetics ; alpha-Crystallin B Chain ; genetics ; metabolism

OBJECTIVE: To establish immortalized embryonic fibroblast lines in heat shock transcription factor 1 (HSF1) HSF1-/- and HSF1+/+ mice and to provide experimental models to study the function of HSF1. METHODS: A mammalian expression vector (pSV3neo) containing the SV40 large T antigen was used to transfect the HSF1-/- and HSF1+/+ mouse embryonic fibroblast using Lipofectamine 2000. Colonies were screened by G418 and expanded to immortalized cell lines. PCR was used to detect the integration of the large T antigen with genome in the mouse embryonic fibroblast. Expression of SV40 large T antigen gene in expanded cells was identified by RT-PCR. HSP70 expression was examined by Western blot in the embryonic fibroblast lines. RESULTS: The stable growth and serial propagation were observed in the HSF1-/- and HSF1+/+ cell lines for six months. The mRNA of SV40 T antigen gene expressed in the two cell lines. HSP70 expression could not be induced in the heat-treated HSF1-/- mouse embryo fibroblasts. CONCLUSION The immortalized cells of HSF1+/+ and HSF1-/- mouse embryo fibroblasts are successfully established.
Animals ; Antigens, Polyomavirus Transforming ; pharmacology ; Cell Line ; DNA-Binding Proteins ; genetics ; Embryo, Mammalian ; Female ; Fibroblasts ; cytology ; Heat Shock Transcription Factors ; Male ; Mice ; Mice, Knockout ; Transcription Factors ; genetics

OBJECTIVETo investigate the expressions of X-linked inhibitor of apoptosis protein (XIAP)-associated factor-1 (XAFI) and heat-shock transcription factor 1 (HSF1) and their relationship in human gastrointestinal cancers.

METHODSImmunoblotting was used to analyze the expressions of HSF1 and XAF1 in gastric and colon cancer tissues and in gastrointestinal cancer cells. The gastrointestinal cancer cells were tranfected with a eukaryotic expression vector containing HSF1 gene fragment or subjected to RNA interference to induce up- or down-regulation of HSF1 expression, and the consequence changes in XAF1 expression in the cells was measured. XAF1 expression was also assayed in the cells after stress stimulation for HSF1 expression.

RESULTSThe expression of HSF1 was higher in gastrointestinal cancer tissues than in normal tissues. The expression of XAF1 and HSF1 was inversely correlated in the cancer cell lines, and stress stimuli of the cells up-regulated the expression of HSF1 but down-regulated XAF1 expression.

CONCLUSIONHSF1 expression is increased in gastrointestinal cancer tissues to result in suppressed expression of XAF1, which may be one of the reasons for the low expression of XAF1 in association with the defect of the apoptosis mechanisms in the cancer cells

Cell Line, Tumor ; Colonic Neoplasms ; genetics ; metabolism ; pathology ; DNA-Binding Proteins ; biosynthesis ; genetics ; Heat Shock Transcription Factors ; Humans ; Immunoblotting ; Intracellular Signaling Peptides and Proteins ; Neoplasm Proteins ; biosynthesis ; genetics ; RNA Interference ; Stomach Neoplasms ; genetics ; metabolism ; pathology ; Transcription Factors ; biosynthesis ; genetics ; Transfection

OBJECTIVEX-linked inhibitor of apoptosis protein (XIAP) To gastrointestinal (GI) investigate the expression of XAF1 and heat-shock transcription factors 1 èHSF1éand their relationship in human gastrointestinal cancers.

METHODSImmunoblotting was used to analyze the expression of HSF1 and XAF1 in either gastric or colon cancer tissue and GI cancer cell line. Transient expression of the HSF1-containing vector in GI cell lines and RNA interference were used to up/down-regulae the expression of the HSF1, and the subsequent expression of XAF1 was measured.

RESULTSThe expression of HSF1 was higher in GI cancers than in normal tissues. The expression of XAF1 and HSF1 was negatively correlated in GI cancer cell lines. Stress stimuli up-regulated the expression of HSF1 while the alteration of XAF1 expression was negatively correlated with HSF1 expression.

CONCLUSIONThe high expression of HSF1 in GI cancers is associated with suppressed expression of XAF1, which can be one of the mechanisms for low-expression of XAF1 and insufficient apoptosis in GI cancers.

Animals ; Base Sequence ; Cell Line, Tumor ; DNA-Binding Proteins ; genetics ; Gastrointestinal Neoplasms ; genetics ; metabolism ; pathology ; Gene Expression Regulation, Neoplastic ; Heat Shock Transcription Factors ; Humans ; Intracellular Signaling Peptides and Proteins ; Neoplasm Proteins ; genetics ; Oxidative Stress ; genetics ; Temperature ; Transcription Factors ; genetics

OBJECTIVE: To screen the inflammatory mediators genes regulated by HSF1, and explore the mechanism of downstream genes regulated by HSF1. METHODS: HSF-/- and HSF1+/+ mice were injected with 15 mg/kg LPS intraperitoneally (ip), respectively, and were treated as previous after HSR. The total RNA of lung tissues were extracted and filtrated by SuperArray gene Microarry. The promoter of candidate genes were analyzed by transcription element search software to search for heat shock element (HSE). Select the suppressor of cytokine signaling 3 (SOCS3) with HSE. Macrophage cells were stimulated with 400 ng/mL LPS, and were treated as previous after HSR, then the total RNA was extracted respectively. RT-PCR and northern blot assay were performed to detect the expression levels of SOCS3 mRNA. RESULTS: Fifteen genes were repressed by HSF1, including 9 genes with complete HSE. Eleven genes were accelerated by HSF1 possibly, including 8 genes with complete HSE. The promoter of SOCS3 gene contained one complete HSE. LPS stimulation obviously increased the levels of SOCS3 mRNA in macrophages of RAW264.7 mice, which was inhibited by HSR and over-expression of HSF1. CONCLUSION HSR or HSF1 inhibits LPS induced expression of SOCS3 mRNA; HSF1 might inhibit LPS-induced expression of SOCS3 mRNA by binding to HSE in the promoter of SOCS3 gene.
Animals ; DNA-Binding Proteins ; genetics ; pharmacology ; Endotoxemia ; chemically induced ; genetics ; Heat Shock Transcription Factors ; Heat-Shock Proteins ; genetics ; Inflammation ; genetics ; Lipopolysaccharides ; Macrophages ; metabolism ; Mice ; Mice, Inbred BALB C ; Mice, Knockout ; Mutation ; RNA, Messenger ; biosynthesis ; genetics ; Signal Transduction ; Suppressor of Cytokine Signaling 3 Protein ; Suppressor of Cytokine Signaling Proteins ; biosynthesis ; genetics ; Transcription Factors ; genetics ; pharmacology

AIMTo assay the transcriptional regulation effect of hHSF1 on prohibitin gene promoter.

METHODSThe total length of hHSF1 exon was amplified by PCR method and cloned into pcDNA3. 1(+) vector. pcDNA3. 1(+)-hHSF1 and pGI3 prohibitin were co-transfected into HEK293 cells. The luciferase activity was detected by Dual-Luciferase Reporter Assay System to evaluate the transcriptional regulation effect of hHSF1 on prohibitin gene promoter.

RESULTSThe pcDNA3.1(+)-hHSF1 vector was constructed successfully. The assay of luciferase activity showed that the transcription of pGL3-prohibitin was dramatically upregulated by hHSF1.

CONCLUSIONhHSF1 can transcriptionally regulate prohibitin expression.

Base Sequence ; DNA-Binding Proteins ; physiology ; Gene Expression Regulation ; HEK293 Cells ; Heat Shock Transcription Factors ; Humans ; Molecular Sequence Data ; Promoter Regions, Genetic ; Repressor Proteins ; genetics ; Transcription Factors ; physiology ; Transcription, Genetic ; Transfection

OBJECTIVETo investigate the influence of heat shock factor1 (HSF1) on gene expression of inflammatory mediators in RAW264.7 murine macrophage cells induced by burn serum.

METHODSSera were separated from blood of normal rats and rats with severe burns, and the recombinant vector pcDNA3. 1/HSF1 was constructed. RAW264.7 macrophages were divided into non-transfection group, vacant vector group (with burn and normal sera stimulation, respectively after vacant vector transfection) and recombinant vector group (with burn and normal sera stimulation, respectively after recombinant vector transfection). Some recombinant vector transfected macrophages without serum stimulation were prepared for the determination of HSF 1 expression with Western blotting. The mRNA expressions of TNF-alpha, HMGB 1 and IL-10 were determined with RT-PCR.

RESULTSThe cell line attained after recombinant vector transfection was comparatively stable,with partial activation of HSF 1. Burn sera markedly upregulated TNF-alpha, HMGB1 mRNA expression (0.910 +/- 0.100, 0.860 +/- 0.020, respectively), but downregulated IL-10 expression (0.430 +/- 0.010, respectively) in normal macrophages, while these genes maintained in a very low level in normal macrophages with normal serum stimulation . macrophages with recombinant vector transfection and burn serum stimulation could obviously inhibit the expression of TNF-alpha and HMGB 1, but enhance the IL-10 gene expression (0.130 +/- 0.100, 0.450 +/- 0.020 , 0.450 +/- 0.020, respectively )when compared with that with vacant vector transfection and burn serum stimulation (0.800 +/- 0.050, 0.880 +/- 0.030, 0.420 +/- 0.010, respectively).

CONCLUSIONHSF1 can inhibit the expression of some pro-inflammatory mediators in macrophages after a severe burns, indicating that appropriate upregulation of anti-inflammatory mediators might exert protective effects on the organism.

Animals ; Burns ; metabolism ; Cell Line ; DNA-Binding Proteins ; genetics ; Female ; Gene Expression ; HMGB1 Protein ; metabolism ; Heat Shock Transcription Factors ; Heat-Shock Response ; genetics ; Inflammation Mediators ; metabolism ; Interleukin-10 ; metabolism ; Macrophages ; metabolism ; Male ; Rats ; Rats, Sprague-Dawley ; Serum ; Transcription Factors ; genetics ; Transfection ; Tumor Necrosis Factor-alpha ; metabolism

AIMFor further investigating of heat shock transcription factor 1 (HSF1) action in thermoregulation and its physiological mechanism.

METHODSThe relationship among the expression of HSF1 and interleukin 1beta (IL-1beta) mRNA and tumor necrosis factor alpha (TNF-alpha) mRNA in monocytes was studied during the different fever stages in rabbit fever model induced by LPS. The expressions of IL-1beta and TNF-alpha mRNA were measured by RT-PCR assay; HSF1 expression was measured by Western blot.

RESULTS(1) Intravenous injection of LPS produced a double-peak temperature arisen at 60 min and 180 min. (2) The expression of IL-1beta mRNA in monocytes had a peak at 160 min, while the peak of TNF-alpha mRNA expression occurred at 80 min after intravenous injection of LPS. (3) The content of the HSF1 trimer increased gradually after 160 min intravenous injection of LPS. The results indicated that the content of the HSF1 trimer was negative correlation with the expressions of IL-1beta mRNA and TNF-alpha mRNA, and the change in body temperature was a positive correlation with IL-1beta mRNA.

CONCLUSIONIt is possible that HSF1 limits the rise in body temperature by repressing the gene expressions of the endogenous pyrogen, IL-1beta and TNF-alpha.

Animals ; DNA-Binding Proteins ; metabolism ; Fever ; metabolism ; Heat Shock Transcription Factors ; Interleukin-1beta ; metabolism ; Male ; Monocytes ; metabolism ; RNA, Messenger ; genetics ; Rabbits ; Transcription Factors ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism