Effect of BIS depletion on HSF1-dependent transcriptional activation in A549 non-small cell lung cancer cells

The expression of BCL-2 interacting cell death suppressor (BIS), an anti-stress or anti-apoptotic protein, has been shown to be regulated at the transcriptional level by heat shock factor 1 (HSF1) upon various stresses. Recently, HSF1 was also shown to bind to BIS, but the significance of these protein-protein interactions on HSF1 activity has not been fully defined. In the present study, we observed that complete depletion of BIS using a CRISPR/Cas9 system in A549 non-small cell lung cancer did not affect the induction of heat shock protein (HSP) 70 and HSP27 mRNAs under various stress conditions such as heat shock, proteotoxic stress, and oxidative stress. The lack of a functional association of BIS with HSF1 activity was also demonstrated by transient downregulation of BIS by siRNA in A549 and U87 glioblastoma cells. Endogenous BIS mRNA levels were significantly suppressed in BIS knockout (KO) A549 cells compared to BIS wild type (WT) A549 cells at the constitutive and inducible levels. The promoter activities of BIS and HSP70 as well as the degradation rate of BIS mRNA were not influenced by depletion of BIS. In addition, the expression levels of the mutant BIS construct, in which 14 bp were deleted as in BIS-KO A549 cells, were not different from those of the WT BIS construct, indicating that mRNA stability was not the mechanism for autoregulation of BIS. Our results suggested that BIS was not required for HSF1 activity, but was required for its own expression, which involved an HSF1-independent pathway.

Heat Shock Factor 1 Predicts Poor Prognosis of Gastric Cancer

PURPOSE: Heat shock factor 1 (HSF1) is a key regulator of the heat shock response and plays an important role in various cancers. However, the role of HSF1 in gastric cancer is still unknown. The present study evaluated the function of HSF1 and related mechanisms in gastric cancer. MATERIALS AND METHODS: The expression levels of HSF1 in normal and gastric cancer tissues were compared using cDNA microarray data from the NCBI Gene Expression Omnibus (GEO) dataset. The proliferation of gastric cancer cells was analyzed using the WST assay. Transwell migration and invasion assays were used to evaluate the migration and invasion abilities of gastric cancer cells. Protein levels of HSF1 were analyzed using immunohistochemical staining of tissue microarrays from patients with gastric cancer. RESULTS: HSF1 expression was significantly higher in gastric cancer tissue than in normal tissue. Knockdown of HSF1 reduced the proliferation, migration, and invasion of gastric cancer cells, while HSF1 overexpression promoted proliferation, migration, and invasion of gastric cancer cells. Furthermore, HSF1 promoted the proliferation of gastric cancer cells in vivo. In Kaplan-Meier analysis, high levels of HSF1 were associated with poor prognosis for patients with gastric cancer (p=0.028). CONCLUSION: HSF1 may be closely associated with the proliferation and motility of gastric cancer cells and poor prognosis of patients with gastric cancer. Accordingly, HSF1 could serve as a prognostic marker for gastric cancer.

Protective effect of HSF1 on mice with LPS-induced acute lung injury and screening of relevant differentially-expressed genes / 中国病理生理杂志

AIM:To study the protective effect of heat shock factor1(HSF1) on the mice with lipopolysaccha-ride (LPS)-induced acute lung injury(ALI),and to screen the relevant differentially-expressed genes. METHODS:ALI mouse model was established by LPS intracheal instillation. The macroscopic and pathological changes of the lung tissue were observed,and the concentrations of total protein,TNF-α, IL-β, IL-6 and VEGF in the bronchoalveolar lavage fluid (BALF) were analyzed. Differentially-expressed genes in the lung tissues of HSF1 +/ +mice and HSF1 -/- mice with ALI induced by LPS were screened by gene chips. The key gene was verified by real-time qPCR. RESULTS:The macroscopic and pathological changes of the lung injury in HSF1 -/- +LPS mice were more serious than those in HSF1 +/ ++LPS mice.The concentrations of total protein,VEGF,TNF-α,IL-1β and IL-6 in the BALF of HSF1 -/- +LPS mice were significantly higher than those of HSF1 +/ ++LPS mice(P<0.05). Compared with the HSF1 +/ +mice,a total of 918 differentially-ex-pressed genes were indentified in the HSF1 -/- mice, among which the expression levels of 65 genes had obvious diffe-rence,with 28 genes up-regulated,including Atg7,ccr1,cxcr2,Tbl1xr1,Mmp9,Pparg,Plcb2,Arrb2,Cntn1,Col4a6, etc, and 37 genes down-regulated,including Fgfr1,Fgfr2,Map4k4,Ddx58,Tfg,Stat3,Smad4,Lamc1,Sdc3,etc. The results of real-time qPCR showed that the mRNA level of CXCR2 in HSF1 -/- + LPS mice was significantly higher than that in HSF1 +/ ++ LPS mice,which was consistent with the results of gene chips. CONCLUSION:HSF1 has protective effect on the mice with LPS-induced ALI. CXCR2 may be involved in the protective effect of HSF1 on this process.

Hsp70 and HSF-1 expression is altered in the tissues of pigs transported for various periods of times

The aim of this study was to assess changes of Hsp70 and HSF-1 protein and mRNA expression in stress-sensitive organs of pigs during transportation for various periods of time. Twenty pigs were randomly divided into four groups (0 h, 1 h, 2 h, and 4 h of transportation). A significant increased activity of AST and CK was observed after 1 h and 2 h of transportation. Histopathological changes in the heart, liver, and stomach indicated that these organs sustained different degrees of injury. Hsp70 protein expression in the heart and liver of transported pigs did not change significantly while it increased significantly (p < 0.05) in the stomach. Hsp70 mRNA levels decreased significantly (p < 0.05) in the heart after 4 h of transportation. However, mRNA expression increased significantly in the liver after 1 (p < 0.05) and 4 h (p < 0.01) of transportation, and increased significantly in the stomach of the transported pigs after 1, 4 (p < 0.01), and 2 h (p < 0.05). HSF-1 levels were reduced at 1 and 4 h (p < 0.05) only in the hearts of transported pigs. These results indicate that Hsp70 mediates distinct stress-related functions in different tissues during transportation.

Study of Dominant-positive Heat Shock Factor 1 on 6-OHDA-induced Cell Death / 中国生物工程杂志

In eukaryotic cells,heat shock factor 1 is the main specific transcription factor mediating the enhanced expression of heat shock proteins when cells experience stresses.It is kept in a latent state by inhibitory complexes under unstressed conditions.It is only transiently activated in response to diverse forms stresses.Dominant-positive heat shock factor 1 has been developed through deletion-mutation.It can activate the expression of endogenous heat shock proteins in the absence of stresses.Environmental neurotoxins play an important role in the pathogenesis of Parkinson's disease.The neurotoxins induce cell death of dopamine neurons through oxidative damage.The results of Western blot and dual-luciferase analysis indicate that the expression of HSP70 was greatly up-regulated in dopaminergic SH-SY5Y cells transfected with dominant-positive heat shock factor 1.To investigate the effect of dominant-positive heat shock factor 1 on 6-OHDA-induced apoptosis in dopaminergic SH-SY5Y cells,the release of lactate dehydrogenase was detected.The result argues that dominant-positive heat shock factor 1 significantly inhibits neurotoxin 6-OHDA-induced cell death in SH-SY5Y cells.The cyto-protective role may be attributed to HSP70 activated by dominant-positive heat shock factor 1.Taken together,it is possible that dominant-positive heat shock factor 1 can be used to prevent or cure Parkinson's disease.

Mechanism of achyphylaxis by bradykinin in opening blood-brain barrier / 中国药理学通报

Aim To assess the effect of heat shock factor-1(HSF1)and heat shock protein 70(HSP70)to tachyphylaxis by bradykinin in the opening blood-tumor barrier(BTB).Methods The C6 rat intracerebral glioma model was constructed by stereotactic implantation technique.Using western blotting method to continue monitoring the protein expression of HSF1 and HSP70 in tumor tissue after bradykinin acted on animals.The expression of occludin in tumor tissue were detected by immunohistochemistry method.Using Evans blue and electron microscope,respectively,detected the permeability and pathology of BTB after intracarotid infusion of bradykinin in C6 rats.Results Bradykinin increased the tight junction opening and the permeability of BTB in C6 animals,and the relative increments of EB were 5.19 ?g?g-1(0 min),5.06 ?g?g-1(5 min),11.35 ?g?g-1(10 min,P

Effect of the polymerization of HSF1 on the febrile response and the content of vasopressin arginine in brain in LPS-induced fever rabbits / 中国药理学通报

Aim To observe the effect of the polymerization of HSF1 on the febrile response in fever rabbits,and further to investigate HSF1 action in thermoregulation and the possible central mechanism.Methods 70 rabbits were divided randomly into 4 groups:the control group(N),the quercetin group(Q),the LPS-feverish group(L),the quercetin+LPS-feverish group(Q+L).Changes in body temperature were continually observed;the expression of HSF1 and HSP70 in hypothalamus was detected by Western blot;the content of AVP in hypothalamus and VSA was measured by radioimmunoassay.Results ① The sequence of the maximum change of temperature(△Tmax)from low to high:group Q