The low intrinsic growth capacity of neurons and an injury-induced inhibitory milieu are major contributo rs to the failure of sensory and motor functional recovery following spinal cord injury.Heat shock transcriptio...The low intrinsic growth capacity of neurons and an injury-induced inhibitory milieu are major contributo rs to the failure of sensory and motor functional recovery following spinal cord injury.Heat shock transcription factor 1(HSF1),a master regulator of the heat shock response,plays neurogenetic and neuroprotective roles in the damaged or diseased central nervous system.However,the underlying mechanism has not been fully elucidated.In the present study,we used a gecko model of spontaneous nerve regeneration to investigate the potential roles of gecko HSF1(gHSF1) in the regulation of neurite outgrowth and inflammatory inhibition of macrophages following spinal cord injury.gHSF1 expression in neurons and microglia at the lesion site increased dramatically immediately after tail amputation.gHSF1 ove rexpression in gecko primary neuro ns significantly promoted axonal growth by suppressing the expression of suppressor of cytokine signaling-3,and fa cilitated neuro nal survival via activation of the mitogen-activated extracellular signal-regulated kinase/extracellular regulated protein kinases and phosphatidylinositol 3-kinase/protein kinase B pathways.Furthermore,gHSF1 efficiently inhibited the macrophagemediated inflammatory response by inactivating 1kappa B-alpha/NF-kappaB signaling.Our findings show that HSF1 plays dual roles in promoting axonal regrowth and inhibiting leukocyte inflammation,and provide new avenues of investigation for promoting spinal co rd injury repair in mammals.展开更多
[ Objective] This study aimed to screen target genes regulated by heat shock factor AtHsfAla in Arabidopsis thaliana. [ Method] Using AtHsfAla-in- serted mutant athsfala （SALK-068042） and wild-type A. thaliana seedl...[ Objective] This study aimed to screen target genes regulated by heat shock factor AtHsfAla in Arabidopsis thaliana. [ Method] Using AtHsfAla-in- serted mutant athsfala （SALK-068042） and wild-type A. thaliana seedlings as experimental materials, target genes regulated by heat shock factor AtHsfAla were screened by microarray assay. Differentially expressed genes were screened by multiple method. Specific functions of differentially expressed genes were analyzed by gene ontology （GO） analysis. Signal transduction pathways, in which differentia｜ly expressed genes were involved, were analyzed by pathway analysis. Gene-gene interaction network was constructed by Signal-Net. [ Result] A total of 3 672 differentially expressed genes were screened out. Up-regulated differentially expressed genes were involved in 198 functions and 7 signal transduction pathways; down-regulated differentially expressed genes were involved in 94 functions and 10 signal transduction pathways. In the signal transduction network, it was found that cwlNV4 and HXK3 had relatively high ability of mediation; AT1 G14240 and cwlNV4 ex- hibited the most interactions with other genes, which were located in key positions throughout the gene-gene interaction network. [ Conclusion] Heat shock factor AtHsfAla regulates a large number of target genes in A. thaliana.展开更多
[ Objective ] Heat shock factors （HSFs） are the major transcription factors of eukaryotic heat shock responses. This study aims to investigate the adversity stress tolerance functions of Arabidopsis heat shock facto...[ Objective ] Heat shock factors （HSFs） are the major transcription factors of eukaryotic heat shock responses. This study aims to investigate the adversity stress tolerance functions of Arabidopsis heat shock factor AtHsfAla, which has important significance for in-depth understanding of adversity stress tolerance mechanisms of plants and further utilization of heat shock factor genes. [Method] Genomic DNA of Arabidopsis was extracted with CTAB method and purified to obtain Arabidopsis DNA samples for in vitro site-specific recombination cloning （ Gateway cloning） to construct plant expression vector of heat shock factor AtHs- fAla. Firstly, donor vector pDONR 201/AtHsfAla was constructed based on attB and attP site-specific recombination method （BP reaction）, to identify E. coli transformants harboring correct sequence of AtHsfAla by sequencing; secondly, plant expression vector pBTWG2/AttlsfAla overexpressing Arabidopsis heat shock factor AtHsfAla was constructed based on attL and attR site-specific recombination method （LR reaction）, to screen E. coli transformants harboring target plasmid. [ Result] Plant expression vector of Arabidopsis heat shock factor gene AtHsfAla was constructed successfully. [ Conclusion] This study not only provided experimental materials for acquiring transgenic plants overexpressing heat shock transcription factor AtHsfAla, but also laid the foundation for further investigation of the diversity of adversity stress tolerance functions reanlated by HSFs.展开更多
Objective: Heat shock factor 1(HSF1), a transcriptional regulator of heat shock proteins(HSPs), is an attractive therapeutic target for cancer. However, only a few HSF1 inhibitors have been identified so far.Methods: ...Objective: Heat shock factor 1(HSF1), a transcriptional regulator of heat shock proteins(HSPs), is an attractive therapeutic target for cancer. However, only a few HSF1 inhibitors have been identified so far.Methods: The mRNA and protein levels of HSF1, HSPs, cleaved PARP, and phosphorylated HSF1 were examined by real-time PCR and Western blot. Forced expression, RNA interference, and immunofluorescence assay were used for mechanistic studies.Cell viability and apoptosis were measured by WST-8 assay and flow cytometry, respectively. Xenograft studies were performed in nude mice to evaluate the effect of dorsomorphin and an HSP90 inhibitor on tumor growth.Results: Dorsomorphin suppressed multiple stimuli-induced and constitutive HSPs expression in cancer cells. Mechanistic studies revealed that dorsomorphin reduced heat-induced HSP expression independent of adenosine monophosphate activated protein kinase. Dorsomorphin reduced heat-stimulated HSF1 Ser320 phosphorylation and nuclear translocation, as well as resting nuclear HSF1 levels in cancer cells. Dorsomorphin induced cancer cell apoptosis by inhibiting HSF1 expression. A structure-activity study revealed that the 4-pyridyl at the 3-site of the pyrazolo [1, 5-a]pyrimidine ring is critical for the anti-HSF1 activities of dorsomorphin. Dorsomorphin sensitized cancer cells to HSP90 and proteasome inhibitors and inhibited HSP70 expression induced by these inhibitors in vitro. In tumor-bearing nude mice, dorsomorphin enhanced HSP90 inhibitor-induced cancer cell apoptosis, tumor growth inhibition, and HSP70 expression.Conclusions: Dorsomorphin is an HSF1 inhibitor. It induces cancer cell apoptosis, sensitizes cancer cells to both HSP90 and proteasome inhibitors, and suppresses HSP upregulation by these drugs, which may prevent the development of drug resistance.Hence, dorsomorphin and its derivates may serve as potential precursors for developing drugs against cancer.展开更多
Increasing evidence suggests that heat shock factor 1 exerts endogenous protective effects on working memory under conditions of chronic psychological stress. However, the precise underlying mechanisms remain poorly u...Increasing evidence suggests that heat shock factor 1 exerts endogenous protective effects on working memory under conditions of chronic psychological stress. However, the precise underlying mechanisms remain poorly understood. This study examined the protective factors affecting working memory in heat shock transcription factor 1 gene knockout mice. The results indicated that the number of correct T maze alternations decreased following mild chronic psychological stress in knockout mice. This change was accompanied by a decrease in neurogenesis and an increase in neuronal apoptosis in the hippocampal dentate gyrus. The number of correct T maze alternations was positively correlated with neurogenesis in hippocampal dentate gyrus, and negatively correlated with neuronal apoptosis. In wild type mice, no significant difference was detected in the number of correct T maze alternations or neuronal apoptosis in hippocampal dentate gyrus. These results indicate that the heat shock factor 1 gene has an endogenous protective role in working memory during mild chronic psychological stress associated with dentate gyrus neuronal apoptosis Moreover, dentate gyrus neurogenesis appears to participate in the protective mechanism.展开更多
Aim Inducible nitric oxide synthase （iNOS） makes a great contribution to host defense and inflamma-tion. In many settings, lipopolysaccharide （LPS） induces iNOS expression through activation of the inhibitor of K...Aim Inducible nitric oxide synthase （iNOS） makes a great contribution to host defense and inflamma-tion. In many settings, lipopolysaccharide （LPS） induces iNOS expression through activation of the inhibitor of KB- α （IKB-α） -nuclear factor-KB （NF-KB） cascade, whereas interferon-γ （IFN-γ） acts through Janus kinase （ JAK）- signal transducer and activator of transcription 1 （ STAT1 ） signals. Heat shock factor 1 （ HSF1 ）, a major regulator of heat shock protein transcription, has been shown to regulate the production of pro-inflammatory cytokines such as tumor necrosis factor-α（TNF-α） and interleukin-6 （IL-6）. But it remains obscure whether and how HSF1 affects iNOS induction. Methods Western blot was used to measure the protein expression. The mRNA level was meas- ured by real time-PCR. Silence of HSF1 was achieved by small interfering RNA. Nitric oxide （NO） content and NF-KB binding activity were assayed by commercial kits. Chromatin immunoprecipitation （CHIP） was used to measure the binding activity of NF-KB and STAT1 to iNOS promoters. Results HSF1 inhibition or knockdown pre- vented the LPS- and/or IFN-γ-stimulated iNOS protein expression in cultured microglia. HSF1 inhibition blocked iNOS mRNA transcription. These inhibitory effects of HSF1 inhibition on iNOS expression were confirmed in brain tissues from endotoxemic mice. Further analysis showed that HSF1 inhibition had no effect on IKB-α degradation and NF-KB or STAT1 phosphorylation in LPS/IFN-γ-stimulated cells. The nuclear transport of active NF-KB or STAT1 was also not affected by HSF1 inhibition. But HSF1 inhibition reduced the binding of NF-KB and STAT1 to their DNA elements. In addition, HSF1 inhibition reduced NF-KB and STAT1 bindings to iNOS promoter inside the LPS/IFN-γ-stimulated cells. Conclusions This preventing effect of HSF1 inhibition on iNOS mRNA transcription presents the necessary role of HSF1 in iNOS induction.展开更多
AIM To identify functional proteins involved in pancreaticduodenal homeobox-1(PDX1)-mediated effects on gastric carcinogenesis.METHODS A PDX1-overexpressed model was established by transfecting gastric cancer cell lin...AIM To identify functional proteins involved in pancreaticduodenal homeobox-1(PDX1)-mediated effects on gastric carcinogenesis.METHODS A PDX1-overexpressed model was established by transfecting gastric cancer cell line SGC7901 with pcDNA3.1(+)-PDX1 vector(SGC-PDX1). Transfection with empty pcDNA3.1 vector(SGC-pcDNA) served as control. Comparative protein profiles of the two groups were analyzed by two-dimensional electrophoresis basedproteomics(2 DE gel-based proteomics). The differential proteins identified by 2 DE were further validated by qRTPCR and immunoblotting. Finally, co-immunoprecipitation was used to determine any direct interactions between PDX1 and the differential proteins.RESULTS2 DE gel proteomics identified seven differential proteins in SGC-PDX1 when compared with those in SGC-pcDNA. These included four heat shock proteins(HSPs; HSP70 p1 B, HSP70 p8, HSP60, HSP27) and three other proteins(ER60, laminin receptor 1, similar to epsilon isoform of 14-3-3 protein). Immunoblotting validated the expression of the HSPs(HSP70, HSP60, HSP27). Furthermore, their expressions were lowered to 80%, 20% and 24%, respectively, in SGC-PDX1, while PDX1 exhibited a 9-fold increase, compared to SGC-pcDNA. However, qRT-PCR analysis revealed that mRNA levels of the HSP s were increased in SGC-PDX1, suggesting that the expression of the HSP s was post-translationally regulated by the PDX1 protein. Finally, co-immunoprecipitation failed to identify any direct interaction between PDX1 and HSP70 proteins.CONCLUSION This study demonstrates the potential involvement of HSPs in PDX1-mediated effects on the genesis of gastric cancer.展开更多
BACKGROUND Heat shock proteins(HSPs)are molecular chaperones that protect cells against cellular stresses or injury.However,it has been increasingly recognized that they also play crucial roles in regulating fundament...BACKGROUND Heat shock proteins(HSPs)are molecular chaperones that protect cells against cellular stresses or injury.However,it has been increasingly recognized that they also play crucial roles in regulating fundamental cellular processes.HSP20 has been implicated in cell proliferation,but conflicting studies have shown that it can either promote or suppress proliferation.The underlying mechanisms by which HSP20 regulates cell proliferation and pluripotency remain unexplored.While the effect of HSP20 on cell proliferation has been recognized,its role in inducing pluripotency in human-induced pluripotent stem cells(iPSCs)has not been addressed.AIM To evaluate the efficacy of HSP20 overexpression in human iPSCs and evaluate the ability to promote cell proliferation.The purpose of this study was to investigate whether overexpression of HSP20 in iPSCs can increase pluripotency and regeneration.METHODS We used iPSCs,which retain their potential for cell proliferation.HSP20 overexpression effectively enhanced cell proliferation and pluripotency.Overexpression of HSP20 in iPSCs was characterized by immunocytochemistry staining and realtime polymerase chain reaction.We also used cell culture,cell counting,western blotting,and flow cytometry analyses to validate HSP20 overexpression and its mechanism.RESULTS This study demonstrated that overexpression of HSP20 can increase the pluripotency in iPSCs.Furthermore,by overexpressing HSP20 in iPSCs,we showed that HSP20 upregulated proliferation markers,induced pluripotent genes,and drove cell proliferation in a sirtuin 1(SIRT1)-dependent manner.These data have practical applications in the field of stem cell-based therapies where the mass expansion of cells is needed to generate large quantities of stem cell-derived cells for transplantation purposes.CONCLUSION We found that the overexpression of HSP20 enhanced the proliferation of iPSCs in a SIRT1-dependent manner.Herein,we established the distinct crosstalk between HSP20 and SIRT1 in regulating cell proliferation and pluripotency.Our study provides novel insights into the mechanisms controlling cell proliferation that can potentially be exploited to improve the expansion and pluripotency of human iPSCs for cell transplantation therapies.These results suggest that iPSCs overexpressing HSP20 exert regenerative and proliferative effects and may have the potential to improve clinical outcomes.展开更多
Objective:To investigate the effect of malarial pigment(hemozoin,HZ) on expression of heat shock proteins(HSPs) and cell viability in human monocytes by using a stable cell line(THP-1 cells).Methods:THP-1 cells were f...Objective:To investigate the effect of malarial pigment(hemozoin,HZ) on expression of heat shock proteins(HSPs) and cell viability in human monocytes by using a stable cell line(THP-1 cells).Methods:THP-1 cells were fed with native HZ or treated with pro-apoptotic molecule gliotoxin for 9 h.Thereafter,the protein expression of HSP-27 and HSP-70 was evaluated by western blotting.Alternatively,HZ-fed cells were cultured up to 72 h and cell viability parameters(survival,apoptosis and necrosis rates) were measured by flow cytometric analysis. Results:HZ increased basal protein levels of HSP-27 without altering those of HSP-70 in THP-1 cells,and promoted long-term cell survival without inducing apoptosis.As expected,gliotoxin inhibited HSP-27 protein expression and promoted long-term cell apoptosis.Conclusions: Present data show that HZ prevents cell apoptosis and enhances the expression of anli-apoptotic HSP-27 in THP-1 cells,confirming the previous evidences obtained from HZ-fed immunopurified monocytes.Since the use of a stable cell line is pivotal to perform HSP-27 silencing experiments, monocytic THP-1 cells could be a good candidate line for such an approach,which is heavily required to clarify the role of HSP-27 in survival of impaired HZ-fed monocytes during falciparum malaria.展开更多
Heat shock proteins (HSPs) serve to correct proteins’ conformation, send the damaged proteins for degradation (quality control function). Heat shock factors (HSFs) are their transcription factors. The protein complex...Heat shock proteins (HSPs) serve to correct proteins’ conformation, send the damaged proteins for degradation (quality control function). Heat shock factors (HSFs) are their transcription factors. The protein complexes mTOR1 and 2 (with the same core mTOR), the phosphoinositide-dependent protein kinase-1 (PDK1), the seine/threonine-specific protein kinase (Akt), HSF1, plus their associated proteins form a network participating in protein synthesis, bio-energy generation, signaling for apoptosis with the help of HSPs. A cancer cell synthesizes proteins at fast rate and needs more HSPs to work on quality control. Shutting down this network would lead to cell death. Thus inhibitors of mTOR (mTORI) and inhibitors of HSPs (HSPI) could drive cancer cell to apoptosis—a “passive approach”. On the other hand, HSPs form complexes with polypeptides characteristic of the cancer cells;on excretion from the cell, they becomes antigens for the immunity cells, eventually leading to maturation of the cytotoxic T cells, forming the basic principle of preparing cancer-specific, person-specific vaccine. Recent finding shows that HSP70 can penetrate cancer cell and expel its analog to extracellular region, giving the hope to prepare a non-person-specific vaccine covering a variety of cancers. Activation of anti-cancer immunity is the “active approach”. On the other hand, mild hyperthermia, with increase of intracellular HSPs, has been found to activate the immunity response, and demonstrate anti-cancer effects. There are certain “mysteries” behind the mechanisms of the active and passive approaches. We analyze the mechanisms involved and provide explanations to some mysteries. We also suggest future research to improve our understanding of these two approaches, in which HSPs play many roles.展开更多
Heat shock proteins (HSPs) are reported to act as effective adjuvants to elicit anti-tumor and anti-infection immunity. Here, we report that Hsp70-like protein 1 (Hsp70L1), a novel HSP derived from human dendritic cel...Heat shock proteins (HSPs) are reported to act as effective adjuvants to elicit anti-tumor and anti-infection immunity. Here, we report that Hsp70-like protein 1 (Hsp70L1), a novel HSP derived from human dendritic cells (DCs), has potent adjuvant effects that polarize responses toward Th1. With a calculated molecular weight of 54.8 kDa, Hsp70L1 is smaller in size than Hsp70 but resembles it both structurally and functionally. Hsp70L1 shares common receptors on DCs with Hsp70 and can interact with DCs, promoting DC maturation and stimulating secretion of the proinflammatory cytokines interleukin 12p70 (IL-12p70), IL-1beta, tumor necrosis factor-alpha (TNF-alpha), and the chemokines IP-10, macrophage inflammatory protein-1alpha (MIP-1alpha), MIP-1beta, and normal T cell expressed and secreted (RANTES). The induction of interferon-gamma-inducible protein 10 (IP-10) secretion by Hsp70L1 is not shared by Hsp70, and other functional differences include more potent stimulation of DC IL-12p70, CC-chemokine, and CCR7 and CXCR4 expression by Hsp70L1. Immunization of mice with the hybrid peptide Hsp70L1-ovalbumin(OVA)(257-264) induces an OVA(257-264)-specific Th1 response and cytotoxic T lymphocyte (CTL) that results in significant inhibition of E.G7-OVA tumor growth. The ability of Hsp70L1 to activate DCs indicates its potential as a novel adjuvant for use with peptide immunizations; the Hsp70L1 antigen peptide hybrid may serve as a more effective vaccine for the control of cancer and infectious diseases.展开更多
基金supported by the National Natural Science Foundation of China,No.31871211 (to YJunW)the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)。
文摘The low intrinsic growth capacity of neurons and an injury-induced inhibitory milieu are major contributo rs to the failure of sensory and motor functional recovery following spinal cord injury.Heat shock transcription factor 1(HSF1),a master regulator of the heat shock response,plays neurogenetic and neuroprotective roles in the damaged or diseased central nervous system.However,the underlying mechanism has not been fully elucidated.In the present study,we used a gecko model of spontaneous nerve regeneration to investigate the potential roles of gecko HSF1(gHSF1) in the regulation of neurite outgrowth and inflammatory inhibition of macrophages following spinal cord injury.gHSF1 expression in neurons and microglia at the lesion site increased dramatically immediately after tail amputation.gHSF1 ove rexpression in gecko primary neuro ns significantly promoted axonal growth by suppressing the expression of suppressor of cytokine signaling-3,and fa cilitated neuro nal survival via activation of the mitogen-activated extracellular signal-regulated kinase/extracellular regulated protein kinases and phosphatidylinositol 3-kinase/protein kinase B pathways.Furthermore,gHSF1 efficiently inhibited the macrophagemediated inflammatory response by inactivating 1kappa B-alpha/NF-kappaB signaling.Our findings show that HSF1 plays dual roles in promoting axonal regrowth and inhibiting leukocyte inflammation,and provide new avenues of investigation for promoting spinal co rd injury repair in mammals.
基金Supported by National Natural Science Foundation of China(31260061,31060039)Key Laboratory of Special Biological Resource Development and Utilization of Universities in Yunnan Province(GXZD201601)+1 种基金Key Discipline Construction Project of Kunming UniversityNational College Students'Innovation Project of China
文摘[ Objective] This study aimed to screen target genes regulated by heat shock factor AtHsfAla in Arabidopsis thaliana. [ Method] Using AtHsfAla-in- serted mutant athsfala （SALK-068042） and wild-type A. thaliana seedlings as experimental materials, target genes regulated by heat shock factor AtHsfAla were screened by microarray assay. Differentially expressed genes were screened by multiple method. Specific functions of differentially expressed genes were analyzed by gene ontology （GO） analysis. Signal transduction pathways, in which differentia｜ly expressed genes were involved, were analyzed by pathway analysis. Gene-gene interaction network was constructed by Signal-Net. [ Result] A total of 3 672 differentially expressed genes were screened out. Up-regulated differentially expressed genes were involved in 198 functions and 7 signal transduction pathways; down-regulated differentially expressed genes were involved in 94 functions and 10 signal transduction pathways. In the signal transduction network, it was found that cwlNV4 and HXK3 had relatively high ability of mediation; AT1 G14240 and cwlNV4 ex- hibited the most interactions with other genes, which were located in key positions throughout the gene-gene interaction network. [ Conclusion] Heat shock factor AtHsfAla regulates a large number of target genes in A. thaliana.
基金Supported by National Natural Science Foundation of China(31060039,31260061)Natural Science Foundation of Yunnan Province(2010ZC163)+1 种基金Project of Kunming University(YJL11025)Fund for Key Discipline Construction of Kunming University
文摘[ Objective ] Heat shock factors （HSFs） are the major transcription factors of eukaryotic heat shock responses. This study aims to investigate the adversity stress tolerance functions of Arabidopsis heat shock factor AtHsfAla, which has important significance for in-depth understanding of adversity stress tolerance mechanisms of plants and further utilization of heat shock factor genes. [Method] Genomic DNA of Arabidopsis was extracted with CTAB method and purified to obtain Arabidopsis DNA samples for in vitro site-specific recombination cloning （ Gateway cloning） to construct plant expression vector of heat shock factor AtHs- fAla. Firstly, donor vector pDONR 201/AtHsfAla was constructed based on attB and attP site-specific recombination method （BP reaction）, to identify E. coli transformants harboring correct sequence of AtHsfAla by sequencing; secondly, plant expression vector pBTWG2/AttlsfAla overexpressing Arabidopsis heat shock factor AtHsfAla was constructed based on attL and attR site-specific recombination method （LR reaction）, to screen E. coli transformants harboring target plasmid. [ Result] Plant expression vector of Arabidopsis heat shock factor gene AtHsfAla was constructed successfully. [ Conclusion] This study not only provided experimental materials for acquiring transgenic plants overexpressing heat shock transcription factor AtHsfAla, but also laid the foundation for further investigation of the diversity of adversity stress tolerance functions reanlated by HSFs.
基金supported by grants from the National Key Research and Development Program of China (Grant No.2017YFC1601702)China Postdoctoral Science Foundation (Grant No.2011M500825)
文摘Objective: Heat shock factor 1(HSF1), a transcriptional regulator of heat shock proteins(HSPs), is an attractive therapeutic target for cancer. However, only a few HSF1 inhibitors have been identified so far.Methods: The mRNA and protein levels of HSF1, HSPs, cleaved PARP, and phosphorylated HSF1 were examined by real-time PCR and Western blot. Forced expression, RNA interference, and immunofluorescence assay were used for mechanistic studies.Cell viability and apoptosis were measured by WST-8 assay and flow cytometry, respectively. Xenograft studies were performed in nude mice to evaluate the effect of dorsomorphin and an HSP90 inhibitor on tumor growth.Results: Dorsomorphin suppressed multiple stimuli-induced and constitutive HSPs expression in cancer cells. Mechanistic studies revealed that dorsomorphin reduced heat-induced HSP expression independent of adenosine monophosphate activated protein kinase. Dorsomorphin reduced heat-stimulated HSF1 Ser320 phosphorylation and nuclear translocation, as well as resting nuclear HSF1 levels in cancer cells. Dorsomorphin induced cancer cell apoptosis by inhibiting HSF1 expression. A structure-activity study revealed that the 4-pyridyl at the 3-site of the pyrazolo [1, 5-a]pyrimidine ring is critical for the anti-HSF1 activities of dorsomorphin. Dorsomorphin sensitized cancer cells to HSP90 and proteasome inhibitors and inhibited HSP70 expression induced by these inhibitors in vitro. In tumor-bearing nude mice, dorsomorphin enhanced HSP90 inhibitor-induced cancer cell apoptosis, tumor growth inhibition, and HSP70 expression.Conclusions: Dorsomorphin is an HSF1 inhibitor. It induces cancer cell apoptosis, sensitizes cancer cells to both HSP90 and proteasome inhibitors, and suppresses HSP upregulation by these drugs, which may prevent the development of drug resistance.Hence, dorsomorphin and its derivates may serve as potential precursors for developing drugs against cancer.
基金the National Natural Science Foundation of China, No. 30170326
文摘Increasing evidence suggests that heat shock factor 1 exerts endogenous protective effects on working memory under conditions of chronic psychological stress. However, the precise underlying mechanisms remain poorly understood. This study examined the protective factors affecting working memory in heat shock transcription factor 1 gene knockout mice. The results indicated that the number of correct T maze alternations decreased following mild chronic psychological stress in knockout mice. This change was accompanied by a decrease in neurogenesis and an increase in neuronal apoptosis in the hippocampal dentate gyrus. The number of correct T maze alternations was positively correlated with neurogenesis in hippocampal dentate gyrus, and negatively correlated with neuronal apoptosis. In wild type mice, no significant difference was detected in the number of correct T maze alternations or neuronal apoptosis in hippocampal dentate gyrus. These results indicate that the heat shock factor 1 gene has an endogenous protective role in working memory during mild chronic psychological stress associated with dentate gyrus neuronal apoptosis Moreover, dentate gyrus neurogenesis appears to participate in the protective mechanism.
文摘Aim Inducible nitric oxide synthase （iNOS） makes a great contribution to host defense and inflamma-tion. In many settings, lipopolysaccharide （LPS） induces iNOS expression through activation of the inhibitor of KB- α （IKB-α） -nuclear factor-KB （NF-KB） cascade, whereas interferon-γ （IFN-γ） acts through Janus kinase （ JAK）- signal transducer and activator of transcription 1 （ STAT1 ） signals. Heat shock factor 1 （ HSF1 ）, a major regulator of heat shock protein transcription, has been shown to regulate the production of pro-inflammatory cytokines such as tumor necrosis factor-α（TNF-α） and interleukin-6 （IL-6）. But it remains obscure whether and how HSF1 affects iNOS induction. Methods Western blot was used to measure the protein expression. The mRNA level was meas- ured by real time-PCR. Silence of HSF1 was achieved by small interfering RNA. Nitric oxide （NO） content and NF-KB binding activity were assayed by commercial kits. Chromatin immunoprecipitation （CHIP） was used to measure the binding activity of NF-KB and STAT1 to iNOS promoters. Results HSF1 inhibition or knockdown pre- vented the LPS- and/or IFN-γ-stimulated iNOS protein expression in cultured microglia. HSF1 inhibition blocked iNOS mRNA transcription. These inhibitory effects of HSF1 inhibition on iNOS expression were confirmed in brain tissues from endotoxemic mice. Further analysis showed that HSF1 inhibition had no effect on IKB-α degradation and NF-KB or STAT1 phosphorylation in LPS/IFN-γ-stimulated cells. The nuclear transport of active NF-KB or STAT1 was also not affected by HSF1 inhibition. But HSF1 inhibition reduced the binding of NF-KB and STAT1 to their DNA elements. In addition, HSF1 inhibition reduced NF-KB and STAT1 bindings to iNOS promoter inside the LPS/IFN-γ-stimulated cells. Conclusions This preventing effect of HSF1 inhibition on iNOS mRNA transcription presents the necessary role of HSF1 in iNOS induction.
基金Supported by Guangdong Natural Science Fund,No.2016A030313765Guangdong medical scientific research fund,No.A2017070 and No.A2017122
文摘AIM To identify functional proteins involved in pancreaticduodenal homeobox-1(PDX1)-mediated effects on gastric carcinogenesis.METHODS A PDX1-overexpressed model was established by transfecting gastric cancer cell line SGC7901 with pcDNA3.1(+)-PDX1 vector(SGC-PDX1). Transfection with empty pcDNA3.1 vector(SGC-pcDNA) served as control. Comparative protein profiles of the two groups were analyzed by two-dimensional electrophoresis basedproteomics(2 DE gel-based proteomics). The differential proteins identified by 2 DE were further validated by qRTPCR and immunoblotting. Finally, co-immunoprecipitation was used to determine any direct interactions between PDX1 and the differential proteins.RESULTS2 DE gel proteomics identified seven differential proteins in SGC-PDX1 when compared with those in SGC-pcDNA. These included four heat shock proteins(HSPs; HSP70 p1 B, HSP70 p8, HSP60, HSP27) and three other proteins(ER60, laminin receptor 1, similar to epsilon isoform of 14-3-3 protein). Immunoblotting validated the expression of the HSPs(HSP70, HSP60, HSP27). Furthermore, their expressions were lowered to 80%, 20% and 24%, respectively, in SGC-PDX1, while PDX1 exhibited a 9-fold increase, compared to SGC-pcDNA. However, qRT-PCR analysis revealed that mRNA levels of the HSP s were increased in SGC-PDX1, suggesting that the expression of the HSP s was post-translationally regulated by the PDX1 protein. Finally, co-immunoprecipitation failed to identify any direct interaction between PDX1 and HSP70 proteins.CONCLUSION This study demonstrates the potential involvement of HSPs in PDX1-mediated effects on the genesis of gastric cancer.
文摘BACKGROUND Heat shock proteins(HSPs)are molecular chaperones that protect cells against cellular stresses or injury.However,it has been increasingly recognized that they also play crucial roles in regulating fundamental cellular processes.HSP20 has been implicated in cell proliferation,but conflicting studies have shown that it can either promote or suppress proliferation.The underlying mechanisms by which HSP20 regulates cell proliferation and pluripotency remain unexplored.While the effect of HSP20 on cell proliferation has been recognized,its role in inducing pluripotency in human-induced pluripotent stem cells(iPSCs)has not been addressed.AIM To evaluate the efficacy of HSP20 overexpression in human iPSCs and evaluate the ability to promote cell proliferation.The purpose of this study was to investigate whether overexpression of HSP20 in iPSCs can increase pluripotency and regeneration.METHODS We used iPSCs,which retain their potential for cell proliferation.HSP20 overexpression effectively enhanced cell proliferation and pluripotency.Overexpression of HSP20 in iPSCs was characterized by immunocytochemistry staining and realtime polymerase chain reaction.We also used cell culture,cell counting,western blotting,and flow cytometry analyses to validate HSP20 overexpression and its mechanism.RESULTS This study demonstrated that overexpression of HSP20 can increase the pluripotency in iPSCs.Furthermore,by overexpressing HSP20 in iPSCs,we showed that HSP20 upregulated proliferation markers,induced pluripotent genes,and drove cell proliferation in a sirtuin 1(SIRT1)-dependent manner.These data have practical applications in the field of stem cell-based therapies where the mass expansion of cells is needed to generate large quantities of stem cell-derived cells for transplantation purposes.CONCLUSION We found that the overexpression of HSP20 enhanced the proliferation of iPSCs in a SIRT1-dependent manner.Herein,we established the distinct crosstalk between HSP20 and SIRT1 in regulating cell proliferation and pluripotency.Our study provides novel insights into the mechanisms controlling cell proliferation that can potentially be exploited to improve the expansion and pluripotency of human iPSCs for cell transplantation therapies.These results suggest that iPSCs overexpressing HSP20 exert regenerative and proliferative effects and may have the potential to improve clinical outcomes.
基金supported by University of Torino Intramural Funds to GG and by grants to MP from the Compagnia di San Paolo,Torino,in the context of the Italian Malaria Network
文摘Objective:To investigate the effect of malarial pigment(hemozoin,HZ) on expression of heat shock proteins(HSPs) and cell viability in human monocytes by using a stable cell line(THP-1 cells).Methods:THP-1 cells were fed with native HZ or treated with pro-apoptotic molecule gliotoxin for 9 h.Thereafter,the protein expression of HSP-27 and HSP-70 was evaluated by western blotting.Alternatively,HZ-fed cells were cultured up to 72 h and cell viability parameters(survival,apoptosis and necrosis rates) were measured by flow cytometric analysis. Results:HZ increased basal protein levels of HSP-27 without altering those of HSP-70 in THP-1 cells,and promoted long-term cell survival without inducing apoptosis.As expected,gliotoxin inhibited HSP-27 protein expression and promoted long-term cell apoptosis.Conclusions: Present data show that HZ prevents cell apoptosis and enhances the expression of anli-apoptotic HSP-27 in THP-1 cells,confirming the previous evidences obtained from HZ-fed immunopurified monocytes.Since the use of a stable cell line is pivotal to perform HSP-27 silencing experiments, monocytic THP-1 cells could be a good candidate line for such an approach,which is heavily required to clarify the role of HSP-27 in survival of impaired HZ-fed monocytes during falciparum malaria.
文摘Heat shock proteins (HSPs) serve to correct proteins’ conformation, send the damaged proteins for degradation (quality control function). Heat shock factors (HSFs) are their transcription factors. The protein complexes mTOR1 and 2 (with the same core mTOR), the phosphoinositide-dependent protein kinase-1 (PDK1), the seine/threonine-specific protein kinase (Akt), HSF1, plus their associated proteins form a network participating in protein synthesis, bio-energy generation, signaling for apoptosis with the help of HSPs. A cancer cell synthesizes proteins at fast rate and needs more HSPs to work on quality control. Shutting down this network would lead to cell death. Thus inhibitors of mTOR (mTORI) and inhibitors of HSPs (HSPI) could drive cancer cell to apoptosis—a “passive approach”. On the other hand, HSPs form complexes with polypeptides characteristic of the cancer cells;on excretion from the cell, they becomes antigens for the immunity cells, eventually leading to maturation of the cytotoxic T cells, forming the basic principle of preparing cancer-specific, person-specific vaccine. Recent finding shows that HSP70 can penetrate cancer cell and expel its analog to extracellular region, giving the hope to prepare a non-person-specific vaccine covering a variety of cancers. Activation of anti-cancer immunity is the “active approach”. On the other hand, mild hyperthermia, with increase of intracellular HSPs, has been found to activate the immunity response, and demonstrate anti-cancer effects. There are certain “mysteries” behind the mechanisms of the active and passive approaches. We analyze the mechanisms involved and provide explanations to some mysteries. We also suggest future research to improve our understanding of these two approaches, in which HSPs play many roles.
文摘Heat shock proteins (HSPs) are reported to act as effective adjuvants to elicit anti-tumor and anti-infection immunity. Here, we report that Hsp70-like protein 1 (Hsp70L1), a novel HSP derived from human dendritic cells (DCs), has potent adjuvant effects that polarize responses toward Th1. With a calculated molecular weight of 54.8 kDa, Hsp70L1 is smaller in size than Hsp70 but resembles it both structurally and functionally. Hsp70L1 shares common receptors on DCs with Hsp70 and can interact with DCs, promoting DC maturation and stimulating secretion of the proinflammatory cytokines interleukin 12p70 (IL-12p70), IL-1beta, tumor necrosis factor-alpha (TNF-alpha), and the chemokines IP-10, macrophage inflammatory protein-1alpha (MIP-1alpha), MIP-1beta, and normal T cell expressed and secreted (RANTES). The induction of interferon-gamma-inducible protein 10 (IP-10) secretion by Hsp70L1 is not shared by Hsp70, and other functional differences include more potent stimulation of DC IL-12p70, CC-chemokine, and CCR7 and CXCR4 expression by Hsp70L1. Immunization of mice with the hybrid peptide Hsp70L1-ovalbumin(OVA)(257-264) induces an OVA(257-264)-specific Th1 response and cytotoxic T lymphocyte (CTL) that results in significant inhibition of E.G7-OVA tumor growth. The ability of Hsp70L1 to activate DCs indicates its potential as a novel adjuvant for use with peptide immunizations; the Hsp70L1 antigen peptide hybrid may serve as a more effective vaccine for the control of cancer and infectious diseases.
