Fas ligand gene expression is directly regulated by stress-inducible heat shock transcription factor-1

The mechanism of immune related signal pathway Egr2-FasL-Fas in transcription regulation and methylated modification of Paralichthys olivaceus under acute hypoxia stress

Apoptosis genes Egr2, Fas and FasL are related to immune responses. However, the mechanism of these genes inducing apoptosis in fish are still not very clear. An acute hypoxia treatment (1.73 ± 0.06 mg/L) for 24 h was carried out on Japanese flounder (Paralichthys olivaceus). The increasingly dense apoptotic signals at 3 h, 6 h, 12 h by TUNEL in skeletal muscle indicated that hypoxia could quickly affect muscle growth and development. Furthermore, we concluded that the Egr2-FasL-Fas signal pathway, which was located at the upstream of apoptotic executor protein caspases, was related to the apoptosis by quantitative real-time PCR, protein concentration detection in ELISA and double gene in situ hybridization methods. The mechanism of the pathway was researched in transcription regulation and epigenetic modification by dual-luciferase reporter assay and bisulfite modified method, respectively. Egr2, as a transcription factor, could up-regulate the expression of FasL gene. And its binding site was mainly between -479 to -1 of FasL gene promoter. The 5th CpG dinucleotides (-514) methylation levels in FasL gene were significantly affected by hypoxia, and they were negatively correlated with its expressions. These suggested that the -514 site may be a very important site to regulate the FasL gene expression. Above results, we concluded that hypoxia activated the immune related signal pathway Egr2-FasL-Fas to induced skeletal muscle apoptosis to affect growth and development of Japanese flounder. The study revealed the mechanism of hypoxia induced apoptosis, which could provide a reference for fish immunity and aquaculture management.

HSF1 Alleviates Microthrombosis and Multiple Organ Dysfunction in Mice with Sepsis by Upregulating the Transcription of Tissue-Type Plasminogen Activator

Sepsis is a life-threatening complication of infection closely associated with coagulation abnormalities. Heat shock factor 1 (HSF1) is an important transcription factor involved in many biological processes, but its regulatory role in blood coagulation remained unclear. We generated a sepsis model in HSF1-knockout mice to evaluate the role of HSF1 in microthrombosis and multiple organ dysfunction. Compared with septic wild-type mice, septic HSF1-knockout mice exhibited a greater degree of lung, liver, and kidney tissue damage, increased fibrin/: fibrinogen deposition in the lungs and kidneys, and increased coagulation activity. RNA-seq analysis revealed that tissue-type plasminogen activator (t-PA) was upregulated in the lung tissues of septic mice, and the level of t-PA was significantly lower in HSF1-knockout mice than in wild-type mice in sepsis. The effects of HSF1 on t-PA expression were further validated in HSF1-knockout mice with sepsis and in vitro in mouse brain microvascular endothelial cells using HSF1 RNA interference or overexpression under lipopolysaccharide stimulation. Bioinformatics analysis, combined with electromobility shift and luciferase reporter assays, indicated that HSF1 directly upregulated t-PA at the transcriptional level. Our results reveal, for the first time, that HSF1 suppresses coagulation activity and microthrombosis by directly upregulating t-PA, thereby exerting protective effects against multiple organ dysfunction in sepsis.

HSF1 Alleviates Microthrombosis and Multiple Organ Dysfunction in Mice with Sepsis by Upregulating the Transcription of Tissue-Type Plasminogen Activator

Sepsis is a life-threatening complication of infection closely associated with coagulation abnormalities. Heat shock factor 1 (HSF1) is an important transcription factor involved in many biological processes, but its regulatory role in blood coagulation remained unclear. We generated a sepsis model in HSF1-knockout mice to evaluate the role of HSF1 in microthrombosis and multiple organ dysfunction. Compared with septic wild-type mice, septic HSF1-knockout mice exhibited a greater degree of lung, liver, and kidney tissue damage, increased fibrin/: fibrinogen deposition in the lungs and kidneys, and increased coagulation activity. RNA-seq analysis revealed that tissue-type plasminogen activator (t-PA) was upregulated in the lung tissues of septic mice, and the level of t-PA was significantly lower in HSF1-knockout mice than in wild-type mice in sepsis. The effects of HSF1 on t-PA expression were further validated in HSF1-knockout mice with sepsis and in vitro in mouse brain microvascular endothelial cells using HSF1 RNA interference or overexpression under lipopolysaccharide stimulation. Bioinformatics analysis, combined with electromobility shift and luciferase reporter assays, indicated that HSF1 directly upregulated t-PA at the transcriptional level. Our results reveal, for the first time, that HSF1 suppresses coagulation activity and microthrombosis by directly upregulating t-PA, thereby exerting protective effects against multiple organ dysfunction in sepsis.

Hyperthermic intraperitoneal chemotherapy (HIPEC): Should we look closer at the microenvironment?

The age of cancer as an isolated single-cell concept is now behind us. It is now established that epithelial ovarian cancer, like other cancers, interacts with the healthy bystander cells to influence them and takes advantage of their nutritional, immunological, disseminating and other capacities. This interaction has become a therapeutic target, as shown by the numerous studies on this subject. Intraperitoneal chemo-hyperthermia has been part of the therapeutic armamentarium for some time yet its efficiency in ovarian cancer has only been recently proven in a randomized controlled trial. However, its therapeutic performance is not revolutionary and epithelial ovarian cancer maintains a high mortality. In this review, we studied the impact of HIPEC on the microenvironment and vice versa to determine whether it could be the key to this lukewarm efficacy. We began by exploring the modalities of HIPEC and establishing the reasons that make this treatment topical. Then, we examined its impact on each element of the tumor environment to obtain a global view of the resistance mechanisms at work in HIPEC.

Direct treatment versus indirect: Thermo-ablative and mild hyperthermia effects

Hyperthermia is a rapidly growing field in cancer therapy and many advances have been made in understanding and applying the mechanisms of hyperthermia. Secondary effects of hyperthermia have been increasingly recognized as important in therapeutic effects and multiple studies have started to elucidate their implications for treatment. Immune effects have especially been recognized as important in the efficacy of hyperthermia treatment of cancer. Both thermo-ablative and mild hyperthermia activate the immune system, but mild hyperthermia seems to be more effective at doing so. This may suggest that mild hyperthermia has some advantages over thermo-ablative hyperthermia and research into immune effects of mild hyperthermia should continue. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Therapeutic Approaches and Drug Discovery > Emerging Technologies Implantable Materials and Surgical Technologies > Nanoscale Tools and Techniques in Surgery.

Heat stress modulates differential response in skin fibroblast cells of native cattle (Bos indicus) and riverine buffaloes (Bubalus bubalis)

Heat stress in hot climates is a major cause that negatively affects dairy animals, leading to substantial economic loss. The present study was aimed to analyze the effect of heat stress on cellular and molecular levels in dermal fibroblast of cattle and buffaloes. Primary fibroblast culture was established using ear pinna tissue samples of cattle (Bos indicus) and riverine buffaloes (Bubalus Bubalis). The cells were exposed to thermal stress at 42°C for 1 h and subsequently allowed to recover and harvest at 37°C at different time points (0, 2, 4, 8, 16, and 24 h) along with control samples. Different cellular parameters viz., apoptosis, proliferation, mitochondrial membrane potential (ΔΨm), oxidative stress, along with expression pattern of heat responsive genes and miRNAs were determined. Cell viability and proliferation rate of heat-stressed fibroblasts decreased significantly (P < 0.05) albeit to a different extent in both species. The cell cytotoxicity, apoptosis, production of reactive oxygen species, and ΔΨm increased more significantly (P < 0.01) in heat stressed fibroblasts of buffalo than cattle. The pattern of heat shock proteins, inflammation/immune genes, and heat responsive miRNA showed differences in induction of their expression level in buffalo and native cattle fibroblasts. Conclusively, finding indicates that heat stress induces more profound impact on buffalo fibroblasts than native cattle fibroblasts. The differential response of cellular parameters, HSP genes, and miRNA expression could be due to better adaptive capacity of skin fibroblast of Bos indicus cattle in comparison with riverine buffaloes.

Tris(8-Hydroxyquinoline)iron induces apoptotic cell death via oxidative stress and by activating death receptor signaling pathway in human head and neck carcinoma cells

BACKGROUND

8-Hydroxyquinoline derivatives have highly sensitive fluorescent chemosensors for metal ions, which are associated with anti-oxidant, anti-tumor and anti-HIV-1 properties. Head and neck squamous cell carcinoma (HNSCC) is associated with a high rate of mortality and novel anti-HNSCC drugs must be developed. Therefore, effective chemotherapy agents are required to address this public health issue.

HYPOTHESIS/PURPOSE

The aim of this study was to investigate the inhibitory effect of tris(8-hydroxyquinoline)iron (Feq₃) on the HNSCC and the underlying mechanism.

STUDY DESIGN/METHODS

A novel 8-hydroxyquinoline derivative, Feq₃, was synthesized. The cell viabilities were analyzed using MTT reagent. Apoptosis and the cell cycle distributions were determined by flow cytometer. Reverse transcription-polymerase chain reaction (RT-PCR), immunofluorescence, western blot, MitoSOX and CellROX stain assay were used to study the mechanism of Feq₃. Feq₃ combined with antioxidants NAC (N-acetylcysteine) and BSO (buthionine sulfoximine) measured the cell viability and intracellular ROS.

RESULTS

Feq₃ induced the death of HNSCC cells and caused them to exhibit the morphological features of apoptosis. Feq₃ also induced apoptosis of SCC9 cells by cell cycle arrest during the G₂/M phase and the induced arrest of SCC25 cells in the G₀/G₁ and G₂/M phases, which was associated with decreased cyclin B1/cdc2 and cyclin D/cdk4 expressions. Feq₃ increases reactive oxygen species (ROS) and reduces glutathione (GSH) levels, and responds to increased p53 and p21 expressions. Feq₃ induced apoptosis by mitochondria-mediated Bax and cytochrome c up-expression and down-expression Bcl-2. Feq₃ also up-regulated tBid, which interacts with the mitochondrial pathway and tumor necrosis factor-α (TNF-α)/TNF-Rs, FasL/Fas, and TNF-related apoptosis inducing ligand receptors (TRAIL-Rs)/TRAIL-dependent caspases apoptotic signaling pathway in HNSCC cells. However, Feq₃ activates Fas but not FasL in SCC25 cells. Feq₃ arrests the growth of HNSCC cells and is involved in the mitochondria- and death receptor (DR)-mediated caspases apoptotic pathway.

CONCLUSION

This study is the first to suggest that apoptosis mediates the anti-HNSCC of Feq₃. Feq₃ has potential as a cancer therapeutic agent against HNSCC.

Immunogenic Effect of Hyperthermia on Enhancing Radiotherapeutic Efficacy

Hyperthermia is a cancer treatment where tumor tissue is heated to around 40 °C. Hyperthermia shows both cancer cell cytotoxicity and immune response stimulation via immune cell activation. Immunogenic responses encompass the innate and adaptive immune systems, involving the activation of macrophages, natural killer cells, dendritic cells, and T cells. Moreover, hyperthermia is commonly used in combination with different treatment modalities, such as radiotherapy and chemotherapy, for better clinical outcomes. In this review, we will focus on hyperthermia-induced immunogenic effects and molecular events to improve radiotherapy efficacy. The beneficial potential of integrating radiotherapy with hyperthermia is also discussed.

Development of rapid and highly sensitive HSPA1A promoter-driven luciferase reporter system for assessing oxidative stress associated with low-dose photodynamic therapy

Photodynamic therapy (PDT) is a regulatory-approved modality for treating a variety of malignant tumors. It induces tumor tissue damage via photosensitizer-mediated oxidative cytotoxicity. The heat shock protein 70 (HSP70-1) is a stress protein encoded by the HSPA1A gene and is significantly induced by oxidative stress associated with PDT. The aim of this study was to identify the functional region of the HSPA1A promoter that responds to PDT-induced oxidative stress and uses the stress responsiveness of HSPA1A expression to establish a rapid and cost-effective photocytotoxic assessment bioassay to evaluate the photodynamic potential of photosensitizers. By constructing luciferase vectors with a variety of hspa1a promoter fractions and examining their relative luciferase activity, we demonstrated that the DNA sequence from -218 to +87 of the HSPA1A gene could be used as a functional promoter to detect the PDT-induced oxidative stress. The maximal relative luciferase activity level of HSPA1A (HSP70-1) induced by hypericin-PDT was nearly nine times that of the control. Our results suggest that the novel reporter gene assay using a functional region of the HSP70A1A promoter has significant advantages for the detection of photoactivity in terms of both speed and sensitivity, when compared with a cell viability test based on ATP quantification and ROS levels. Furthermore, phthalocyanine zinc and methylene blue both induced significantly elevated levels of relative luciferase activity in a dose-dependent manner.

Sulfuretin from heartwood of Rhus verniciflua triggers apoptosis through activation of Fas, Caspase-8, and the mitochondrial death pathway in HL-60 human leukemia cells

Sulfuretin, a flavonoid isolated from heartwood of Rhus verniciflua, has been reported to have anti-cancer activities but the underlying molecular mechanism was not clear. In this study, sulfuretin induced apoptosis by activating caspases-8, -9, and -3 as well as cleavage of poly(ADP-ribose) polymerase. Furthermore, treatment with sulfuretin caused mitochondrial dysfunctions, including the loss of mitochondrial membrane potential (ΔΨ(m)), the release of cytochrome c to the cytosol, and the translocations of Bax and tBid. Sulfuretin also activated the extrinsic apoptosis pathway, that is, it increased the expressions of Fas and FasL, the activation of caspase-8, and the cleavage of Bid. Furthermore, blocking the FasL-Fas interaction with NOK-1 monoclonal antibody prevented the sulfuretin-induced apoptosis. The therapeutical effect of sulfuretin in leukemia is due to its potent apoptotic activity through the extrinsic pathway driven by a Fas-mediated caspase-8-dependent pathway.