Heat Shock Transcription Factor 1 Expression Research Articles

Astragaloside IV ameliorates pressure overload-induced heart failure by enhancing angiogenesis through HSF1/VEGF pathway

Astragaloside IV(AS-IV), the main active ingredient of Astragalus, has been used as a treatment for heart failure with favorable effects, but its molecular mechanism has not been fully elucidated. Network pharmacological analysis and molecular docking revealed that Heat shock transcription factor 1 (HSF1) is a potential target of AS-IV. We designed cellular and animal experiments to investigate the role and intrinsic molecular mechanisms of AS-IV in ameliorating pressure overload-induced heart failure. In cellular experiments, Myocardial microvascular endothelial cells (MMVECs) were cultured in isolation and stimulated by adding high and low concentrations of AS-IV, and a cell model with down-regulation of HSF1 expression was constructed by using siRNA technology. Changes in the expression of key molecules of HSF1/VEGF signaling pathway and differences in tube-forming ability were detected in different groups of cells using PCR, WB and tube-forming assay. In animal experiments, TAC technology was applied to establish a pressure overload-induced heart failure model in C57 mice, postoperative mice were ingested AS-IV by gavage, and adenoviral transfection technology was applied to construct a mouse model with down-regulation of HSF1 expression.Small animal ultrasound for cardiac function assessment, MASSON staining, CD31 immunohistochemistry, and Western blotting (WB) were performed on the mice. The results showed that AS-IV could promote the expression of key molecules of HSF1/VEGF signaling pathway, enhance the tube-forming ability of MMVECs, increase the density of myocardial capillaries, reduce myocardial fibrosis, and improve the cardiac function of mice with TAC.AS-IV could modulate the HSF1/VEGF signaling pathway to promote the angiogenesis and improve the pressure overload-induced heart failure.

HDAC6 modulates the cognitive behavioral function and hippocampal tissue pathological changes of APP/PS1 transgenic mice through HSP90-HSF1 pathway.

The aim of this study was to investigate histone deacetylase 6 (HDAC6) modifies the heat shock protein 90 (HSP90) and heat shock transcription factor 1 (HSF1) affect the levels of pathological markers such as Aβ oligomers (Aβo) and Tau phosphorylation (p-Tau) in APP/PS1 double transgenic mice hippocampal tissues or HT22 neurons as well as the changes in cognitive behavioral functions of mice. (1) APP/PS1 transgenic mice (6 months old, 25 ~ 30g) were randomly assigned to 5 experimental groups, C57BL/6J mice (6 months old, 25 ~ 30g) were used as 4 control groups, with 8 mice in each group. All mice underwent intracerebroventricular (i.c.v.) cannulation, and the experimental groups were administered with normal saline (APP + NS group), HDAC6 agonist tubastatin A hydrochloride (TSA) (APP + TSA group) or HDAC6 agonist theophylline (Theo) (APP + Theo group), HSP90 inhibitor Ganetespib (Gane) (APP + Gane group), or a combination of pre-injected Gane by TSA (APP + Gane + TSA group); the control group received i.c.v. injections of Gane (Gane group), TSA (TSA group), Theo (Theo group) or NS (NS group), respectively. (2) Mouse hippocampal neurons HT22 were randomly divided into a control group (Control) and an Aβ1-42 intervention group (Aβ). Within the Aβ group, further divisions were made for knockdown HSP90 (Aβ + siHSP90 group), overexpression HSP90 (Aβ + OE-HSP90 group), knockdown HSF1(Aβ + siHSF1 group) and knockdown HSF1 followed by overexpression HSP90 (Aβ + siHSF1 + OE-HSP90 group), resulting in a total of 6 groups. Morris water maze test was used to evaluate the cognitive behavior of the mice. Western blot and immunohistochemistry or immunofluorescence were performed to detect the levels of HDAC6, HSP90, HSF1, Aβ1-42, Tau protein, and p-Tau in the hippocampal tissue or HT22 cells. qRT-PCR was used to measure the levels of hdac6, hsp90, and hsf1 mRNA in the hippocampus or nerve cells. (1) The levels of HDAC6, Aβ1-42 and p-Tau were elevated, while HSP90 and HSF1 were decreased in the hippocampal tissue of APP/PS1 transgenic mice (all P < 0.01). Inhibiting HDAC6 upregulated the expressions of HSP90 and HSF1 in the hippocampal tissue of APP/PS1 mice, while decreasing the levels of Aβ1-42 and p-Tau as well as improving the spatial cognitive behavior in mice (P < 0.05 or P < 0.01). The opposite effects were observed upon HDAC6 activation. However, inhibiting HSP90 reduced the expression of HSF1 (P < 0.01) and increased the levels of Aβ1-42 and p-Tau (P < 0.05 or P < 0.01) but did not significantly affect the expression of HDAC6 (P > 0.05). No significant changes were observed in the aforementioned indicators in the 4 control groups (P > 0.05). (2) In the Aβ1-42 intervention group, HDAC6 and Aβ1-42, p-Tau expression levels were elevated, while HSP90 and HSF1 expressions were all decreased, and cell viability was reduced (P < 0.05 or P < 0.01). Overexpression of HSP90 upregulated HSF1 expression, decreased the levels of Aβ1-42 and p-Tau, and increased cell viability (P < 0.05 or P < 0.01). Knocking down HSP90 had the opposite effect; and knocking down HSF1 increased the levels of Aβ1-42 and p-Tau and decreased cells viability (all P < 0.01), but did not result in significant changes in the expression levels of HSP90 (P > 0.05). Inhibiting HDAC6 can upregulate the expressions of HSP90 and HSF1 but reduce the levels of Aβ1-42 and p-Tau in the hippocampus of APP/PS1 mice and improvement of cognitive behavioral function in mice; Overexpression of HSP90 can increase HSF1 but decrease Aβ1-42 and p-Tau levels in the hippocampal neurons and increase cell activity. It is suggested that HDAC6 may affect the formation of Aβ oligomers and the changes in Tau protein phosphorylation levels in the hippocampus of AD transgenic mouse as well as the alterations in cognitive behavioral functions by regulating the HSP90-HSF1 pathway.

Cancer-associated fibroblast exosomes promote prostate cancer metastasis through miR-500a-3p/FBXW7/HSF1 axis under hypoxic microenvironment.

Metastasis is the main cause of deaths in prostate cancer (PCa). However, the exact mechanisms underlying PCa metastasis are not fully understood. In this study, we discovered pronounced hypoxia in primary lesions of metastatic PCa(mPCa). The exosomes secreted by cancer-associated fibroblasts (CAFs) under hypoxic conditions significantly enhance PCa metastasis both in vitro and in vivo. Through miRNA sequencing and reverse transcription quantitative PCR (RT-qPCR), we found that hypoxia elevated miR-500a-3p levels in CAFs exosomes. Subsequent RT-qPCR, western blotting, and dual luciferase reporter assays identified F-box and WD repeat domain-containing 7(FBXW7) as a target of miR-500a-3p. In addition, immunohistochemistry revealed that FBXW7 expression decreased with the progression of PCa, while heat shock transcription factor 1(HSF1) expression increased. Introducing an FBXW7 plasmid into PCa cells reduced their metastatic potential and significantly lowered HSF1 expression. These findings suggest that CAFs exosomes drive PCa metastasis via the miR-500a-3p/FBXW7/HSF1 axis in a hypoxic microenvironment. Targeting either hypoxia or exosomal miR-500a-3p could be a promising strategy for PCa management.

HSF1 inhibits microglia activation to attenuate neuroinflammation via regulating miR-214-3p and NFATc2 in Parkinson's disease.

Parkinson's disease (PD) is characterized by microglia activation that leads to neuroinflammation. Heat shock transcription factor 1 (HSF1) is known to exert neuroprotective effects on neurodegenerative diseases. This study sought to analyse the role and mechanism of HSF1 in PD-induced neuroinflammation. The PD mouse models were established using 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Animal behaviour capacities and neuronal damage were assessed via behavioural tests, tyrosine hydroxylase (TH) staining, and immunofluorescence. Levels of HSF1, miR-214-3p, nuclear factor of activated T cells 2 (NFATc2), and neuroinflammatory factors were detected via RT-qPCR, Western blotting, and ELISA.Binding relationships between HSF1 and miR-214-3p, miR-214-3p, and NFATc2 were tested via dual-luciferase or chromatin immunoprecipitation assays. Functional rescue experiments were designed to confirm the roles of miR-214-3p and NFATc2. HSF1 expression in brain tissues was downregulated upon MPTP treatment. HSF1 overexpression reduced motor deficits and loss of dopaminergic neurons, increased TH-positive neurons, and repressed neuroinflammation and micro-glia activation. Mechanically, HSF1 bound to the miR-214-3p promoter to increase its expression and inhibited NFATc2 transcription. miR-214-3p downregulation or NFATc2 overexpression reversed the inhibition of HSF1 overexpression on neuroinflammation and microglia activation. Overall, our findings unveiled the therapeutic role of HSF1 in PD-induced neuroinflammation and microglia activation via regulating miR-214-3p and NFATc2.

HSF1 is involved in suppressing A1 phenotype conversion of astrocytes following spinal cord injury in rats

BackgroundTwo activation states of reactive astrocytes termed A1 and A2 subtypes emerge at the lesion sites following spinal cord injury (SCI). A1 astrocytes are known to be neurotoxic that participate in neuropathogenesis, whereas A2 astrocytes have been assigned the neuroprotective activity. Heat shock transcription factor 1 (HSF1) plays roles in protecting cells from stress-induced apoptosis and in controlling inflammatory activation. It is unknown whether HSF1 is involved in suppressing the conversion of A1 astrocytes following SCI.MethodsA contusion model of the rat spinal cord was established, and the correlations between HSF1 expression and onset of A1 and A2 astrocytes were assayed by Western blot and immunohistochemistry. 17-AAG, the agonist of HSF1, was employed to treat the primary cultured astrocytes following a challenge by an A1-astrocyte-conditioned medium (ACM) containing 3 ng/ml of IL-1α, 30 ng/ml of TNF-α, and 400 ng/ml of C1q for induction of the A1 subtype. The effects of 17-AAG on the phenotype conversion of astrocytes, as well as underlying signal pathways, were examined by Western blot or immunohistochemistry.ResultsThe protein levels of HSF1 were significantly increased at 4 days and 7 days following rat SCI, showing colocalization with astrocytes. Meanwhile, C3-positive A1 astrocytes were observed to accumulate at lesion sites with a peak at 1 day and 4 days. Distinctively, the S100A10-positive A2 subtype reached its peak at 4 days and 7 days. Incubation of the primary astrocytes with ACM markedly induced the conversion of the A1 phenotype, whereas an addition of 17-AAG significantly suppressed such inducible effects without conversion of the A2 subtype. Activation of HSF1 remarkably inhibited the activities of MAPKs and NFκB, which was responsible for the regulation of C3 expression. Administration of 17-AAG at the lesion sites of rats was able to reduce the accumulation of A1 astrocytes.ConclusionCollectively, these data reveal a novel mechanism of astrocyte phenotype conversion following SCI, and HSF1 plays key roles in suppressing excessive increase of neurotoxic A1 astrocytes.

Activation of the M3AChR and Notch1/HSF1 Signaling Pathway by Choline Alleviates Angiotensin II-Induced Cardiomyocyte Apoptosis.

Angiotensin II- (Ang II-) induced cardiac hypertrophy and apoptosis are major characteristics of early-stage heart failure. Choline exerts cardioprotective effects; however, its effects on Ang II-induced cardiomyocyte apoptosis are unclear. In this study, the role and underlying mechanism of choline in regulating Ang II-induced cardiomyocyte apoptosis were investigated using a model of cardiomyocyte apoptosis, which was induced by exposing neonatal rat cardiomyocytes to Ang II (10−6 M, 48 h). Choline promoted heat shock transcription factor 1 (HSF1) nuclear translocation and the intracellular domain of Notch1 (NICD) expression. Consequently, choline attenuated Ang II-induced increases in mitochondrial reactive oxygen species (mtROS) and promotion of proapoptotic protein release from mitochondria, including cytochrome c, Omi/high-temperature requirement protein A2, and second mitochondrial activator of caspases/direct inhibitor of apoptosis-binding protein with low P. The reversion of these events attenuated Ang II-induced increases in cardiomyocyte size and numbers of terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling-positive cells, presumably via type 3 muscarinic acetylcholine receptor (M3AChR). Indeed, downregulation of M3AChR or Notch1 blocked choline-mediated upregulation of NICD and nuclear HSF1 expression, as well as inhibited mitochondrial apoptosis pathway and cardiomyocyte apoptosis, indicating that M3AChR and Notch1/HSF1 activation confer the protective effects of choline. In vivo studies were performed in parallel, in which rats were infused with Ang II for 4 weeks to induce cardiac apoptosis. The results showed that choline alleviated cardiac remodeling and apoptosis of Ang II-infused rats in a manner related to activation of the Notch1/HSF1 pathway, consistent with the in vitro findings. Taken together, our results reveal that choline impedes oxidative damage and cardiomyocyte apoptosis by activating M3AChR and Notch1/HSF1 antioxidant signaling, and suggest a novel role for the Notch1/HSF1 signaling pathway in the modulation of cardiomyocyte apoptosis.

Fto Promotes Extramedullary Progression of Multiple Myeloma By Regulation of HSF1 through m6a RNA Methylation

Introduction :Extramedullary myeloma (EMM), defined by the presence of clonal cells outside the bone marrow, has extraordinarily heterogeneous biological and clinical features and is associated with an adverse prognosis. Recent studies have shown the upregulation of heat shock transcription factor 1 (HSF1) in EMM (Heimberger et al, Brit J Haematol 2013), but little is known about its role and mechanisms underlying the regulation. There is growing evidence that dysregulation of N6-methyladenosine (m6A) RNA methylation plays an important role in tumor invasion and metastasis (Pan et al, J Hematol Oncol 2018) and the m6A RNA modifications are involved in the heat shock response. This study was designed to reveal that the fat mass and obesity-associate protein (FTO), as a major m6A demethylase, plays a critical oncogenic role in extramedullary metastasis in multiple myeloma (MM) through regulating HSF1 and heat shock proteins (HSPs). Methods and results: Using transcriptome sequencing, we determined that FTO was significantly upregulated in plasma cells (PCs) from EMM and MM patients, compared to healthy donors. We then evaluated the expression levels of FTO and HSF1 in plasma cells (PCs) from EMM patients by qRT-PCR and western blot analysis. The results verified that FTO and HSF1 were markedly upregulated in PCs from newly diagnosed MM patients compared to healthy donors, and it was further upregulated in PCs from patients with EMM. And the expression levels of FTO was positively correlated with HSF1. Measured by colorimetric assay, we found that m6A RNA methylation level of EMM patients was lower than the level of MM and healthy donors, which was consistent with the expression of FTO in EMM patients. Importantly, enforced expression or knockdown expression of FTO via lentivirus transfection, dramatically influenced the proliferation, migration and invasion in MM cells. m6A RNA methylation has been reported to been associated with heat shock response (Zhou et al, Nature 2015). We therefore examined whether FTO can regulate HSF1 in EMM. Enforced expression of FTO dramatically elevated the level of HSF1 and HSPs in MM.1R and RPMI8226 cells, while inhibition of FTO reduced the level of HSF1 and HSPs. Through m6A sequencing and RNA sequencing, we confirmed that HSF1 was a novel target of FTO. Indeed, the demethylase FTO could positively regulate the expression of HSF1 at both the mRNA and protein levels in MM cells. In addition, knockdown of HSF1 by siRNA markedly reduced the ability of migration and invasion of MM cells overexpressing FTO. Thus, these results suggest that HSF1 is a key target gene of demethylase FTO in EMM. Moreover, pharmacological inhibitors of FTO, MA and MA2, could significantly enhance the effect of bortezomib in MM cells. Recent studies have suggested that for m6A modification to exert its biological functions, it must first be recognized by m6A reader proteins. Here, we evaluated whether demethylase FTO could regulate the level of HSF1 via YTHDF2, a crucial m6A reader protein. We confirmed with colorimetric assay that overexpression of FTO could reduce m6A levels in MM cells, and knockdown of FTO could enhance the m6A levels. Using RNA immuno-precipitation sequence (RIP-seq), we identified direct binding between the 3' end of the HSF1 transcript and the m6A reader protein YTHDF2. Consistently, we showed that silencing of YTHDF2 with siRNA strongly promoted HSF1 expression in MM cells with knockdown of FTO. In addition, by RNA stability analysis, we found that the YTHDF2 could regulate the expression of HSF1 through affecting the stability of HSF1. Next, we evaluated whether FTO could regulate extramedullary metastasis of MM in vivo. NCG mice were injected via tail vein with RPMI-8226-luc cells to establish EMM xenografts. Mice were assessed by in vivo bioluminescent imaging and PET-CT. The results showed that combined treatment with MA2 plus bortezomib could remarkably reduce the extramedullary metastasis in MM. Conclusions: Our datas reveal that FTO is frequently up-regulated in EMM and contributes to MM progression. FTO promotes HSF1 expression through inhibiting the degradation effect of YTHDF2 by reducing m6A levels in these mRNA transcripts. Therefore, FTO-YTHDF2-HSF1 regulatory axis may potentially be applied in EMM treatment. Disclosures No relevant conflicts of interest to declare.

Copy number of 8q24.3 drives HSF1 expression and patient outcome in cancer: an individual patient data meta-analysis

BackgroundThe heat-shock transcription factor 1 (HSF1) has been linked to cell proliferation and survival in cancer and has been proposed as a biomarker for poor prognosis. Here, we assessed the role of HSF1 expression in relation to copy number alteration (CNA) and cancer prognosis.MethodsUsing 10,287 cancer genomes from The Cancer Genome Atlas and Cbioportal databases, we assessed the association of HSF1 expression with CNA and cancer prognosis. CNA of 8q24.3 was categorized as diploid (reference), deletion (fewer copies), gain (+ 1 copy) and amplification (≥ + 2 copies). Multivariate logistic regression modeling was used to assess 5-year survival among those with a first cancer diagnosis and complete follow-up data (N = 9568), categorized per anatomical location and histology, assessing interaction with tumor stage, and expressed as odds ratios and 95% confidence intervals.ResultsWe found that only 54.1% of all tumors have a normal predicted 8q24.3 copy number and that 8q24.3 located genes including HSF1 are mainly overexpressed due to increased copies number of 8q24.3 in different cancers. The tumor of patients having respectively gain (+ 1 copy) and amplification (≥ + 2 copies) of 8q24.3 display a global increase of 5-year mortality (odds ratio = 1.98, 95% CI 1.22–3.21) and (OR = 2.19, 1.13–4.26) after full adjustment. For separate cancer types, tumor patients with 8q24.3 deletion showed a marked increase of 5-year mortality in uterine (OR = 4.84, [2.75–8.51]), colorectal (OR = 4.12, [1.15–14.82]), and ovarian (OR = 1.83, [1.39–2.41]) cancers; and decreased mortality in kidney cancer (OR = 0.41, [0.21–0.82]). Gain of 8q24.3 resulted in significant mortality changes in 5-year mortality for cancer of the uterus (OR = 3.67, [2.03–6.66]), lung (OR = 1.76, [1.24–2.51]), colorectal (OR = 1.75, [1.32–2.31]) cancers; and amplification for uterine (OR = 4.58, [1.43–14.65]), prostate (OR = 4.41 [3.41–5.71]), head and neck (OR = 2.68, [2.17–3.30]), and stomach (OR = 0.56, [0.36–0.87]) cancers.ConclusionsHere, we show that CNAs of 8q24.3 genes, including HSF1, are tightly linked to 8q24.3 copy number in tumor patients and can affect patient outcome. Our results indicate that the integration of 8q24.3 CNA detection may be a useful predictor for cancer prognosis.

RNAi based transcriptome suggests genes potentially regulated by HSF1 in the Pacific oyster Crassostrea gigas under thermal stress

BackgroundThe Pacific oyster Crassostrea gigas is an important fishery resource that is sensitive to temperature fluctuations. Thus, it has evolved a protection mechanism against heat stress by increasing the expression of the gene coding for heat shock protein (HSP) 70 under elevated temperatures. In other animals, heat shock response is a transcriptional response driven by the heat shock transcription factor 1 (HSF1) and thermal stress can trigger HSP70 expression to protect the organism via HSF1. However, the regulatory relationship between HSF1 and HSP remains unclear in Pacific oyster. Therefore, in the present study, we examined the transcriptomic response of several to thermal stress following HSF1 interference.ResultsWe identified 150 genes responsive to heat shock including seven HSP genes, six of which belonging to the group of 17 HSP genes enriched in response to heat shock, according to weighted gene co-expression network analysis (WGCNA). The other gene was enriched in the module correlated with HSF1 interference. In addition, we found 48 and 47 genes that were upregulated and downregulated by HSF1 in response to heat shock, respectively. In the upregulated genes, we identified one HSP70 potentially regulated by HSF1 in response to heat shock. Furthermore, based on differentially expressed genes and WGCNA analyses, we found that the hypoxia signaling pathway was enriched under heat shock conditions. Five genes were then selected to detect dynamic changes through time. The results suggested that gene expression was correlated with HSF1 expression. The regulation of HSP70 by HSF1 was preliminarily confirmed by binding site predictions and by a dual luciferase assay.ConclusionsOur results revealed that the expression of HSP70 and HSP20 was initially triggered after 2 h of heat shock, and one of the HSP70 genes was potentially regulated by HSF1. From these results, it is evident that not all heat-inducible genes were triggered simultaneously in response to heat shock stress. Overall, the results revealed a possible HSF1–HSP regulatory relationship in Pacific oyster, providing valuable information on the mechanisms of thermal tolerance in this commercially important oyster.

Neuroprotective Effects of HSF1 in Retinal Ischemia-Reperfusion Injury.

PurposeRetinal ischemia, a common cause of several vision-threatening diseases, contributes to the death of retinal neurons, particularly retinal ganglion cells (RGCs). Heat shock transcription factor 1 (HSF1), a stress-responsive protein, has been shown to be important in response to cellular stress stimuli, including ischemia. This study is to investigate whether HSF1 has a role in retinal neuronal injury in a mouse model of retinal ischemia-reperfusion (IR).MethodsIR was induced by inserting an infusion needle into the anterior chamber of the right eye and elevating a saline reservoir connected to the needle to raise the intraocular pressure to 110 mm Hg for 45 minutes. HSF1, Hsp70, molecules in the endoplasmic reticulum (ER) stress branches, tau phosphorylation, inflammatory molecules, and RGC injury were determined by immunohistochemistry, Western blot, or quantitative PCR.ResultsHSF1 expression was significantly increased in the retina 6 hours after IR. Using our novel transgenic mice carrying full-length human HSF gene, we demonstrated that IR-induced retinal neuronal apoptosis and necroptosis were abrogated 12 hours after IR. RGCs and their function were preserved in the HSF1 transgenic mice 7 days after IR. Mechanistically, the beneficial effects of HSF1 may be mediated by its induction of chaperone protein Hsp70 and alleviation of ER stress, leading to decreased tau phosphorylation and attenuated inflammatory response 12 to 24 hours after IR.ConclusionsThese data provide compelling evidence that HSF1 is neuroprotective against retinal IR injury, and boosting HSF1 expression may be a beneficial strategy to limit neuronal degeneration in retinal diseases.

Increased HSF1 expression predicts shorter disease-specific survival of prostate cancer patients following radical prostatectomy.

Prostate cancer is a highly heterogeneous disease and the clinical outcome is varying. While current prognostic tools are regarded insufficient, there is a critical need for markers that would aid prognostication and patient risk-stratification. Heat shock transcription factor 1 (HSF1) is crucial for cellular homeostasis, but also a driver of oncogenesis. The clinical relevance of HSF1 in prostate cancer is, however, unknown. Here, we identified HSF1 as a potential biomarker in mRNA expression datasets on prostate cancer. Clinical validation was performed on tissue microarrays from independent cohorts: one constructed from radical prostatectomies from 478 patients with long term follow-up, and another comprising of regionally advanced to distant metastatic samples. Associations with clinical variables and disease outcomes were investigated. Increased nuclear HSF1 expression correlated with disease advancement and aggressiveness and was, independently from established clinicopathological variables, predictive of both early initiation of secondary therapy and poor disease-specific survival. In a joint model with the clinical Cancer of the Prostate Risk Assessment post-Surgical (CAPRA-S) score, nuclear HSF1 remained a predictive factor of shortened disease-specific survival. The results suggest that nuclear HSF1 expression could serve as a novel prognostic marker for patient risk-stratification on disease progression and survival after radical prostatectomy.

Response of gut health and microbiota to sulfide exposure in Pacific white shrimp Litopenaeus vannamei

Sulfide is a natural and widely distributed toxicant. It can be commonly found on the interface between water and sediment in the aquatic environment. The Pacific white shrimp Litopenaeus vannamei starts life in the benthic zone soon after the mysis stage, an early stage of post larvae. Therefore, L. vannamei is inevitably affected by exposure to sulfide released from pond sediment. This study explored the toxicant effect of different concentrations of sulfide on the intestinal health and microbiota of Pacific white shrimp by monitoring the change of expression of inflammatory, immune related cytokines, and the structure of the intestinal microbiota. The gut histology, expressions of inflammatory and immune related cytokines (tumor necrosis factor-alpha, C-type lectin 3, myostatin and heat shock transcription factor 1), and the microbiota were determined in L. vannamei after exposure to 0 (control), 425.5 (1/10 LC 50–96 h), and 851 μg/L (1/5 LC 50–96 h) of sulfide for 21 days. With the increase of sulfide concentration, intestinal injury was aggravated and the inflammatory and immune related cytokines generated a range of reactions. The expression of myostatin (MSTN) was significantly down-regulated by the concentration of sulfide exposure. No difference in the expression of heat shock transcription factor 1 (HSF1) was found between the control and shrimp exposed to 425.5 μg/L, but significantly higher HSF1 expression was found in shrimp exposed to 851 μg/L of sulfide. Significantly higher values of tumor necrosis factor-alpha (TNF-α) and C-type lectin 3 (CTL3) were found in the shrimp exposed to 425.5 μg/L of sulfide compared to the control, but a lower value was found in the shrimp exposed to 851 μg/L (P < 0.05). Sulfide also changed the intestinal microbial communities. The abundance of pathogenic bacteria, such as Cyanobacteria, Vibrio and Photobacterium, increased significantly with exposure to the increasing concentration of sulfide. The abundance of some anti-stress bacteria, such as Chlorobi and Fusobacterium, increased. Nitrospirae which can alleviate nitrite toxicity decreased. Microbacterium, Parachlamydia, and Shewanella were all commonly found and down-regulated in both sulfide groups, which is associated with an adaptation to sulfide stimulation. This study indicates that chronic exposure to sub-lethal levels of sulfide could lead to damage of the gut structure, stimulate the response of the inflammatory and immune systems, and shape the structure of the gut microbiota in L. vannamei.

Doxorubicin attenuates CHIP-guarded HSF1 nuclear translocation and protein stability to trigger IGF-IIR-dependent cardiomyocyte death.

Doxorubicin (DOX) is one of the most effective antitumor drugs, but its cardiotoxicity has been a major concern for its use in cancer therapy for decades. Although DOX-induced cardiotoxicity has been investigated, the underlying mechanisms responsible for this cardiotoxicity have not been completely elucidated. Here, we found that the insulin-like growth factor receptor II (IGF-IIR) apoptotic signaling pathway was responsible for DOX-induced cardiotoxicity via proteasome-mediated heat shock transcription factor 1 (HSF1) degradation. The carboxyl-terminus of Hsp70 interacting protein (CHIP) mediated HSF1 stability and nuclear translocation through direct interactions via its tetratricopeptide repeat domain to suppress IGF-IIR expression and membrane translocation under physiological conditions. However, DOX attenuated the HSF1 inhibition of IGF-IIR expression by diminishing the CHIP–HSF1 interaction, removing active nuclear HSF1 and triggering HSF1 proteasomal degradation. Overexpression of CHIP redistributed HSF1 into the nucleus, inhibiting IGF-IIR expression and preventing DOX-induced cardiomyocyte apoptosis. Moreover, HSF1A, a small molecular drug that enhances HSF1 activity, stabilized HSF1 expression and minimized DOX-induced cardiac damage in vitro and in vivo. Our results suggest that the cardiotoxic effects of DOX result from the prevention of CHIP-mediated HSF1 nuclear translocation and activation, which leads to an upregulation of the IGF-IIR apoptotic signaling pathway. We believe that the administration of an HSF1 activator or agonist may further protect against the DOX-induced cell death of cardiomyocytes.

Effect of Geranylgeranylacetone on Ultraviolet Radiation Type B-Induced Cataract in Heat-Shock Transcription Factor 1 Heterozygous Mouse

ABSTRACTPurpose: We investigated whether heat-shock transcription factor 1 (HSF1) was involved in ultraviolet radiation type B (UVR-B)-induced lens opacity (cataract) using HSF1 heterozygous mice. We also examined the effects of geranylgeranylacetone (GGA), an inducer of heat-shock proteins via activation of HSF, on the UVR-B-induced cataract.Material and Methods: Male HSF1+/– and WT mice were unilaterally exposed to UVR-B (total: 1200mJ) at 16 weeks of age. At 48 h after the last UVR-B irradiation, the lens was isolated and the induction of the cataract was quantified as the cataract area ratio (opacity area/anterior capsule). GGA was orally administered at a dosage of 500 mg/kg once a day for two days before the first UVR-B exposure until the end of the experiment (21days in total).Results: The HSF1 expression was more greatly decreased in the lens from HSF1+/– mice than in that from WT mice (p < 0.01). UVR-B exposure could mainly induce cataracts in the anterior capsule in both HSF1+/– and WT mice, while the opacity of the lens was markedly enhanced in HSF1+/– mice compared to that in WT mice(p (0.01). GGA treatment could prevent the induction of lens opacity by UVR-B exposure in both WT and HSF1+/– mice as compared with the non-administration group (p < 0.01). No obvious alteration by the UVR-B radiation was seen in lens protein levels of αA-crystallin, αB-crystallin, or γ-crystallin with or without GGA administration among all groups of mice. In contrast to the crystallins, the lens protein level of HSP25 was decreased by UVR-B exposure in both HSF1+/– and WT mice, and was significantly recovered in WT mice by the GGA treatment (p < 0.01). The induction of HSP25 was suppressed in HSF1+/– mice compared with that in WT mice.Conclusions: These data suggest that HSF1 plays an important role in the occurrence of UVR-B-induced cataracts, possibly via regulation of HSPs such as HSP25.

Upregulation of HSF1 in estrogen receptor positive breast cancer.

Heat shock transcription factor 1 (HSF1), a key regulator of the heat-shock response, is deregulated in many cancers. HSF1 can mediate cancer cell survival and metastasis. High levels of HSF1 have been associated with poor prognosis in breast cancer. The nature of HSF1 upregulation needs to be validated in different cohorts to further validate its prognostic utility in breast cancer.We first evaluated its expression in a cohort of breast cancer tissue microarrays with Oncotype DX recurrence scores available using immunohistochemistry. To further confirm the clinical relevance and prognostic impact, mutational and methylation status of the gene were also assessed in The Cancer Genome Atlas and publically available microarray datasets.Immunohistochemical analysis showed that HSF1 expression is independent of Oncotype DX high recurrence score in ER-positive node-negative patients. Analysis of The Cancer Genome Atlas data revealed upregulation of HSF1 is not due to methylation or mutation. HSF1 copy number variations and amplifications (15%) were not associated with survival. In publicly available microarray datasets, a prognostic impact was observed in ER-positive tumors, but not in ER-negative tumors. Patients with ER-positive tumors with high HSF1 levels were associated with shorter overall survival (P = 0.00045) and relapse-free survival (P = 0.0057). In multivariable analysis, HSF1 remained a significant prognostic parameter.The mRNA expression levels of HSF1 in ER-positive breast cancer are associated with both shorter relapse-free and overall survival. This prognostic impact is specific to mRNA expression, but stayed insignificant by protein expression or by analyzing amplification events.

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Objectives Heat shock proteins (HSPs) are induced in cells as a protective mechanism to cope with cellular stress. The activation of the heat shock response is mediated by heat shock transcription factor 1 (HSF1). HSFs (HSF1-4) bind to the promoter regions of target genes. HSF 1 exists in a complex with HSP40, HSP70 and HSP90 as inactive monomers; after stress HSF 1 is and trimerizes. We reported a spatial expression of HSPs in the placenta and that this is altered in pre-eclampsia (Abdulsid et al., 2013). Aims: To investigate whether expression of HSF-1 alters and may explain the changes in HSP expression. Methods Placental samples were obtained from 8 sites within each placenta: 4 equally spaced apart pieces were sampled from the inner, middle and outer zones of the placenta (Abdulsid et al., 2013). Non-labor, labor, labor pre-eclampsia and non-labor pre-eclampsia were studied. HSF 1 expression was investigated by Western blot analysis and real time PCR. Results Two HSF1 bands were observed which, according to the data sheet represent the phosphorylated 80 kDa and non-phosphorylated 65 kDa forms. HSF1; 65 kDa was significantly increased in both the pre-eclampsia non-labor and labor groups compared to the normal non-labor and labor groups at the inner zone (p = 0.04, p = 0.008 respectively). There was a significant decrease in 65 kDa HSF1 in labor pre-eclampsia compared to the control labor group at the middle zone (p = 0.004). There was no difference in the phosphorylated form of HSF1. No changes at the mRNA level were found when non-labor and labor pre-eclampsia were compared to control groups. When labor and non-labor groups were combined, there was a significant increase in pre-eclampsia compared to the normotensive groups at the inner and middle zones (p = 0.007, p = 0.02 respectively). Conclusions Changes in HSF1 expression occur during labor and pre-eclampsia but at different zones within the placenta. Disclosures A. Abdulsid: None. K. Hanretty: None. F. Lyall: None.

L-glutamine supplementations enhance liver glutamine-glutathione axis and heat shock factor-1 expression in endurance-exercise trained rats.

Liver L-glutamine is an important vehicle for the transport of ammonia and intermediary metabolism of amino acids between tissues, particularly under catabolic situations, such as high-intensity exercise. Hence, the aim of this study was to investigate the effects of oral supplementations with L-glutamine in its free or dipeptide forms (with L-alanine) on liver glutamine-glutathione (GSH) axis, and 70 kDa heat shock proteins (HSP70)/heat shock transcription factor 1 (HSF1) expressions. Adult male Wistar rats were 8-week trained (60 min/day, 5 days/week) on a treadmill. During the last 21 days, the animals were daily supplemented with 1 g of L-glutamine/kg body weight per day in either l-alanyl-L-glutamine dipeptide (DIP) form or a solution containing L-glutamine and l-alanine in their free forms (GLN+ALA) or water (controls). Exercise training increased cytosolic and nuclear HSF1 and HSP70 expression, as compared with sedentary animals. However, both DIP and GLN+ALA supplements enhanced HSF1 expression (in both cytosolic and nuclear fractions) in relation to exercised controls. Interestingly, HSF1 rises were not followed by enhanced HSP70 expression. DIP and GLN+ALA supplements increased plasma glutamine concentrations (by 62% and 59%, respectively) and glutamine to glutamate plasma ratio in relation to trained controls. This was in parallel with a decrease in plasma ammonium levels. Supplementations increased liver GSH (by 90%), attenuating the glutathione disulfide (GSSG) to GSH ratio, suggesting a redox state protection. In conclusion, oral administration with DIP and GLN+ALA supplements in endurance-trained rats improve liver glutamine-GSH axis and modulate HSF1 pathway.

Heat shock transcription factor 1 expression is spatially distributed and selectively down-regulated in the human placenta during labour

Heat shock transcription factor 1 expression is spatially distributed and selectively down-regulated in the human placenta during labour

Prognostic value of peritumoral heat-shock factor-1 in patients receiving resection of hepatocellular carcinoma

Background:The cross-talk of hepatocellular carcinoma (HCC) cells and abnormal metabolic signals in peritumoral microenvironment modifies our knowledge of hepatocarcinogenesis. As an indispensable modulator of various stresses, the clinical significance of heat-shock transcription factor-1 (HSF1) in HCC microenvironment has never been defined.Methods:Hepatocellular carcinoma and matched peritumoral liver tissues (n=332) were semiquantitatively analysed for HSF1 expression, followed by correlation with clinicopathological parameters (patient outcomes). Moreover, the effects of HSF1 deficiency in L02 on monocarboxylate transporter-4 (MCT4) and HCC cells' colonisation and proliferation were investigated.Results:High expression of HSF1 in peritumoral tissue but not in HCC tissue was associated with poorer overall survival (OS) and time to recurrence (TTR), especially early recurrence (ER), which was further reconfirmed in validation cohort. Multivariate analysis showed that prognostic performance of peritumoral HSF1 was independent of other clinicopathological factors (hazard ratio for OS=2.60, P=0.002, for TTR=2.52, P<0.001). Notably, downregulation of HSF1 in L02 decreased MCT4 expression significantly. The supernatant from L02-shRNA-HSF1 in hypoxia, NOT normoxia condition, inhibited HCC cell colonisation and proliferation. Moreover, the combination of peritumoral HSF1 and MCT4 was the best predictor for ER and OS.Conclusion:High peritumoral HSF1 expression can serve as a sensitive ‘readout' for high-risk HCC ER, and could be a potential metabolic intervention target following curative resection.

Glutamine‐mediated Dual Regulation of Heat Shock Transcription Factor‐1 Activation and Expression

Heat shock factor‐1 (HSF1) is the master regulator for cytoprotective heat shock protein (Hsp) expression. It is widely thought that HSF1 expression is non‐inducible and thus the key control point of HSP expression is regulation of HSF1's transactivation activity. How HSF1 expression is regulated remains unknown. Herein, we demonstrate that glutamine (Gln) enhanced Hsp expression both in rat colonic epithelium in vivo and in cultured non‐transformed colonic YAMC cells. This was associated with upregulated HSF1's transactivation activity via increased HSF1 trimerization, nuclear localization and DNA binding. Intriguingly, Gln enhanced HSF1 protein and mRNA expression and Hsf1 gene promoter activity. Within the −281/−200 region of the Hsf1 promoter, deletion of the putative CCAAT enhancer binding protein (C/EBP) binding site abolished Gln's HSF1 response. Gln availability strikingly altered the ratio of C/EBPβ inhibitory and active isoforms, i.e., liver‐enriched inhibitory protein (LIP) and liver‐enriched activating protein (LAP). LIP and LAP were further shown to be independent repressor and activator respectively for Hsf1 gene transcription and the relative abundance of these two C/EBPβ isoforms was demonstrated to determine Hsf1 transcription. We show for the first time that Gln not only enhances HSF1's transactivation, but also induces Hsf1 gene transcription in a C/EBPβ‐dependent manner.