OBJECTIVEA CAT reporter plasmid (pBLCAT3alpha1) driven by the promoter of hsp90alpha was in vitro assembled into chromatin to investigate the transcription activity of the reporter gene upon heat shock.

METHODSA competitive RT-PCR-based technique was used to quantify the promoter activity of hsp90alpha gene on chromatin or naked DNA templates in vitro.

RESULTSThe in vitro transcription efficiency was first optimized by using different amounts of whole cell extracts from heat shock-treated HeLa cells. In vitro chromatin assembly was carried out with purified components of chromatin assembly associated factors, core histones and CAT reporter gene driven by the promoter of hsp90alpha gene. Results showed that chromatin formation repressed the in vitro transcription of the gene.

CONCLUSIONThe heat shock induced transcription of hsp90alpha gene on chromatin template is more efficient than that on naked DNA in vitro.

Chromatin Assembly and Disassembly ; genetics ; Genes, Reporter ; genetics ; HSP90 Heat-Shock Proteins ; genetics ; Heat-Shock Response ; genetics ; Humans ; Transcription, Genetic

OBJECTIVE: Our aim was to explore whether heat stress protein (HSP) 9 preferentially expresses under heat stress and affects the expression of other heat stress proteins as well as to explore the effect of HSPB9 overexpression and knockdown on apoptosis in DF-1. METHODS: We used gene cloning to construct an overexpression vector of the target gene, and synthesized the target gene interference fragment to transfect the chicken fibroblast cell line. Gene and protein expression, as well as apoptosis, were detected by RT-qPCR, Western blot, and flow cytometry. RESULTS: Chicken DF-1 cells showed an early state of apoptosis in the early stages of HSPB9 overexpression. In the later stages, as HSPB9 expression increased, the cells showed inhibition of apoptosis. When the cells were under heat stress, HSPB9 expression was much higher and earlier than the expression of HSPB1 and HSPA2. In addition, high expression of HSPB9 had a negative effect on HSPB1 and HSPA2 expression. This negative feedback decreased the percentage of early stages of apoptotic cells and promoted cell survival. CONCLUSION HSPB9 expression, although rapid, is detrimental to cell survival early during its overexpression. In heat stress, HSPB9 overexpression, while inhibiting the expression of HSPA2 and HSPB1, is beneficial to cell survival.
Animals ; Apoptosis ; genetics ; Avian Proteins ; genetics ; Cell Line ; Chickens ; Heat-Shock Proteins ; genetics ; Heat-Shock Response ; genetics

Pinellia ternata is an important medicinal plant, and its growth and development are easily threatened by high temperature. In this study, comprehensive research on physiological, cytological and transcriptional responses to different levels of heat stress were conducted on a typical phenotype of P. ternata. First, P. ternata exhibited tolerance to the increased temperature, which was supported by normal growing leaves, as well as decreased and sustained photosynthetic parameters. Severe stress aggravated the damages, and P. ternata displayed an obvious leaf senescence phenotype, with significantly increased SOD and POD activities (46% and 213%). In addition, mesophyll cells were seriously damaged, chloroplast thylakoid was fuzzy, grana lamellae and stroma lamellae were obviously broken, and grana thylakoids were stacked, resulting in a dramatically declined photosynthetic rate (74.6%). Moreover, a total of 16 808 genes were significantly differential expressed during this process, most of which were involved in photosynthesis, transmembrane transporter activity and plastid metabolism. The number of differentially expressed transcription factors in MYB and bHLH families was the largest, indicating that these genes might participate in heat stress response in P. ternata. These findings provide insight into the response to high temperature and facilitate the standardized cultivation of P. ternata.
Pinellia/genetics* ; Heat-Shock Response/genetics* ; Photosynthesis/genetics* ; Plants, Medicinal/genetics* ; Phenotype

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

OBJECTIVETo explore the effect of a non-lethal heat shock, in comparison with the treatment of interferon-gamma (IFN gamma), on the expression of major histocompatibility complex transactivator (CTA) and its downstream target gene of the human leukocyte antigens (HLA)-DR in Jurkat cells.

METHODSThe changes of CTA mRNA in Jurkat cells before and after the treatment of heat shock or IFN gamma were detected using real time RT-PCR. The changes of CTA protein were detected with Western blot. The expression of HLA-DR was detected with flow cytometry. : CTA mRNA and protein were induced in Jurkat cells under heat shock, but not with IFN-gamma. The expression of HLA-DR gene significantly increased after recovery (P<0.01).

CONCLUSIONThe expressions of CTA and HLA-DR in Jurkat cells remarkably increase after heat shock, indicating that heat shock may help reconstruct relevant genes in cells with immunologic gene deficiencies.

HLA-DR Antigens ; metabolism ; Heat-Shock Response ; physiology ; Humans ; Jurkat Cells ; Nuclear Proteins ; genetics ; metabolism ; RNA, Messenger ; genetics ; Trans-Activators ; genetics ; metabolism

OBJECTIVEBenzo[a]pyrene (B[a]P), a ubiquitous environmental pollutant, is a potent procarcinogen and mutagen that can elicit tumors, leading to malignancy. Heat shock proteins (Hsp) have been shown to protect cells against damages caused by various stresses including exposure to numerous chemicals. Whether Hsps, or more specifically Hsp70, are involved in repair of B[a]P-induced DNA damage is currently unknown.

METHODSWe assessed the potential role of the inducible form of Hsp70 in B[a]P-induced DNA damage of human embryonic lung (HEL) cells using immunoblot and the comet assay (i.e., the single cell gel electrophoresis assay).

RESULTSExposure to B[a]P induced a dose-dependent decrease in the level of Hsp70, but a dose-dependent +-increase in DNA damage both in untreated (control) HEL cells and in cells preconditioned by a heat treatment. Heat preconditioning prior to B[a]P exposure potentiated the effect of B[a]P at a low dose (10 micromol/L), but appeared to be protective at higher doses. There was a negative correlation between Hsp70 level and DNA damage in the non-preheated as well as in the preconditioned cells.

CONCLUSIONThese data suggest that exposure of HEL cells to B[a]P may induce a dose-dependent reduction in the levels of the inducible Hsp70. The detailed mechanisms for the reduction of Hsp70 levels by B[a]P and the role of Hsp70 in DNA damage under different concentrations of B[a]P remains to be determined.

Benzo(a)pyrene ; Blotting, Western ; Carcinogens, Environmental ; Cells, Cultured ; Comet Assay ; DNA ; drug effects ; DNA Damage ; Dose-Response Relationship, Drug ; HSP70 Heat-Shock Proteins ; analysis ; biosynthesis ; genetics ; Humans

AIMTo study the mechanisms of protection of bcl-2 gene transfection against heat-stressed cardiomyocytes.

METHODSCardiomyocytes were isolated and cultured. bcl-2 was transfected into cardiomyocytes with Lipofectamine transfection methods. The cardiomyocytes were stressed by heat. The change of H+ -ATPase synthesis activity of cardiomyocytes mitochondria caused by bcl-2 transfection was measured by chemical radiation method. The changes of Caspase 3 activity of cardiomyocytes caused by bcl-2 transfection was measured by fluorometric analysis.

RESULTSbcl-2 transfection could increase the H+ -ATPase synthesis activity of cardiomyocytes mitochondria under heat stress at 41 degrees C and 43 degrees C and could decrease the Caspase 3 activity of cardiomyocytes under heat stress at 41 degrees C and 43 degrees C.

CONCLUSIONThe protection effect of bcl-2 transfection on heat-stressed cardiomyocytes may be associated with preserved H+ ATPase synthesis activity of cardiomyocytes mitochondria and the activity of Caspase 3 of cardiomyocytes.

Animals ; Caspase 3 ; metabolism ; Cells, Cultured ; Genes, bcl-2 ; Heat-Shock Response ; genetics ; Myocytes, Cardiac ; cytology ; metabolism ; Proton-Translocating ATPases ; metabolism ; Rats ; Transfection

This study was purposed to investigate the effect of different heat stress conditions on expression level of heat shock protein gp96 in K562 cell line of chronic myeloid leukemia in order to provide experiment basis for seeking optimal heat stress condition increasing extraction amount of gp96 from K562 cells. The expression changes of gp96 in K562 cell line was detected by immunocytochemistry under 38, 40, 42, 44, 46 and 48 degrees C for 30 minutes in water, by flow cytometry under 40, 44, 48 and 52 degrees C for 30 minutes in water, by Western blot under 40, 44, 48 and 52 degrees C for 30 minutes in water. Immunocytochemistry assay showed that gp96 existed mainly in cytoplasm. The peak of gp96 expression was at 30 minutes after 48 degrees C in water. The result of flow cytometry was consistent to immunocytochemistry detection results under temperatures 40, 44, 48 and 52 degrees C (P < 0.01). Western blot showed that detection result was the same as the immunocytochemistry and flow cytometry detections. In conclusion, the expression of gp96 in K562 cell line reached peak at 30 minutes after 48 degrees C in water. This condition may be an effective preparative condition for extraction of gp96 from K562 cells.
Antigens, Neoplasm ; biosynthesis ; genetics ; Blotting, Western ; Flow Cytometry ; Heat-Shock Response ; Humans ; Immunohistochemistry ; K562 Cells ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; metabolism ; pathology

OBJECTIVETo study the pattern of polymorphism expression of heat-shock protein 70 (HSP70) family in A549 cell line treated with different concentrations of benzo(a)pyrene (BaP) and its probable biological effect.

METHODTwo-dimensional polyacrylamide gel electrophoresis (2D-PAGE) was used for the HSP70 expression analysis.

RESULTS2D-PAGE showed that when A549 cells were exposed to different concentrations of BaP (0.1, 1.0, 5.0, 10.0 micromol/L) for 24, 48 h respectively, the HSP72 in A549 gradually declined as BaP concentrations increased [the integral OD (IOD)] for 24 h were: 150.36 +/- 26.03, 98.57 +/- 13.34, 64.92 +/- 15.03, 34.65 +/- 19.10, 32.92 +/- 18.71 respectively, for 48 h: 126.85 +/- 17.41, 106.19 +/- 15.32, 73.64 +/- 21.02, 35.18 +/- 11.95, 16.27 +/- 9.35 respectively), while the IOD of HSP73 did not show any remarkable change (24 h: 102.29 +/- 21.24, 87.71 +/- 18.70, 71.19 +/- 14.08, 71.87 +/- 15.16, 72.78 +/- 17.31 respectively; 48 h: 86.66 +/- 16.86, 75.67 +/- 10.61, 66.83 +/- 12.63, 67.29 +/- 10.26, 91.37 +/- 13.68 respectively).

CONCLUSIONBaP can inhibit HSP72 expression and with certain dose-effect relationship, but cannot affect HSP73 expression.

Benzo(a)pyrene ; Cell Line, Tumor ; Dose-Response Relationship, Drug ; Electrophoresis, Polyacrylamide Gel ; HSP70 Heat-Shock Proteins ; genetics ; metabolism ; Humans ; Polymorphism, Genetic

OBJECTIVETo explore heat shock protein 70 (HSP70) expression of A549 cells and its role in DNA damage caused by benzo(a)pyrene (BaP).

METHODSHuman adenocarcinoma A549 cells were cultured in vitro, exposed by different concentrations of BaP (0, 1.25, 2.50, 5.00, 10.00 micro mol/L) for 6 hours, or 10 micro mol/L of BaP for different time (0, 4, 8, 12, 16, 24 and 48 h). Then HSP70 expression and DNA damage were detected using Western-blot and single cell gel electrophoresis (SCGE) assay respectively, and the relationship between HSP70 expression and DNA damage was further analyzed.

RESULTSThe integral optical densities of HSP70 in A549 cells treated with 1.25, 2.50, 5.00 and 10.00 micro mol/L BaP for 6 h (49.63 +/- 1.30, 45.72 +/- 1.03, 40.53 +/- 0.95, 37.50 +/- 1.20 respectively) were lower than that of the control cells (59.43 +/- 1.17) (P < 0.05). When A549 cells were exposed to 10 micro mol/L BaP for 4, 8, 12, 16 h, the integral optical densities of HSP70 were 33.33 +/- 0.80, 29.23 +/- 0.91, 12.51 +/- 0.96, 9.50 +/- 1.25 respectively, and there was an increasing tendency of the expression of HSP70 for 24 - 48 h (20.06 +/- 1.38, 24.51 +/- 1.39), however, all were different from that in control group (56.59 +/- 0.85) (P < 0.05). DNA damage scores in 10(6) A549 cells treated with 2.50, 5.00 and 10.00 micro mol/L BaP for 6 h (23,718 +/- 2,938, 30,128 +/- 2,937, 44,231 +/- 3,846) were significantly higher than that of the control cell (9,615 +/- 1,923) (P < 0.05). When A549 cells were exposed to 10 micro mol/L BaP for 4, 8, 12, 16, 24, 48 h, DNA damage scores (16,667 +/- 4,003, 38,461 +/- 1,924, 5,615 +/- 3,847, 76,282 +/- 2,937, 7,513 +/- 1,110 and 58,975 +/- 9,487) were also higher than that of control group (P < 0.05). There was a negative correlation between DNA damage and the expression of HSP70 when A549 cells were exposed to different concentrations of BaP.

CONCLUSIONHSP70 might enhance intracellular defenses against DNA damage induced by BaP.

Benzo(a)pyrene ; toxicity ; Blotting, Western ; Cell Line, Tumor ; Comet Assay ; DNA ; drug effects ; genetics ; DNA Damage ; Dose-Response Relationship, Drug ; HSP70 Heat-Shock Proteins ; analysis ; Humans ; Time Factors