Heat Shock Co-Activates Interleukin-8 Transcription

Singh, Ishwar; Gupta, Aditi; Nagarsekar, Ashish; Cooper, Zachary A.; Manka, Cheu; Hester, Lisa; Benjamin, Ivor J.; He, Ju; Hasday, Jeffrey D.

doi:10.1165/rcmb.2007-0294oc

Cited by 56 publications

(78 citation statements)

References 36 publications

(45 reference statements)

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“…We and others have demonstrated that elements of the HS response are activated at febrile-range temperatures and regulate genes involved in inflammation and the innate immune response, including tumor necrosis factor α (Ostberg et al 2000;Singh et al 2002Singh et al , 2000, interleukin (IL)-1β (Cahill et al 1996;Fairchild et al 2000), IL-8, and granulocyte macrophage colony-stimulating factor (Rice et al 2005;Singh et al 2008), as well as HSPs. A computerassisted analysis of CXC chemokine promoters showed that almost every member of this family of neutrophil chemotaxins contains HSEs within their promoter sequences, suggesting these genes may be a newly recognized class of HSF-1-regulated genes (Nagarsekar et al 2005).…”

Section: Discussionmentioning

confidence: 99%

Hyperthermia in the febrile range induces HSP72 expression proportional to exposure temperature but not to HSF-1 DNA-binding activity in human lung epithelial A549 cells

Tulapurkar

Asiegbu

Singh

et al. 2009

Cell Stress and Chaperones

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Expression of heat shock proteins (HSPs) is classically activated at temperatures above the physiologic range (≥42°C) via activation of the stress-activated transcription factor, heat shock factor-1 (HSF-1). Several studies suggest that less extreme hyperthermia, especially within the febrile range, as occurs during fever and exertional/environmental hyperthemia, can also activate HSF-1 and enhance HSP expression. We compared HSP72 protein and mRNA expression in human A549 lung epithelial cells continuously exposed to 38.5°C, 39.5°C, or 41°C or exposed to a classic heat shock (42°C for 2 h). We found that expression of HSP72 protein and mRNA increased linearly as incubation temperature was increased from 37°C to 41°C, but increased abruptly when the incubation temperature was raised to 42°C. A similar response in luciferase activity was observed using A549 cells stably transfected with an HSF-1-responsive luciferase reporter plasmid. However, activation of intranuclear HSF-1 DNA-binding activity was comparable at 38.5°C, 39.5°C, and 41°C and only modestly greater at 42°C but the mobility of HSF1 protein on a denaturing gel was altered with increasing exposure temperature and was distinctly different at 42°C. These findings indicate that the proportional changes in HSF-1-dependent HSP72 expression at febrile-range temperatures are dependent upon exposure time and temperature but not on the degree of HSF-1 DNA-binding activity. Instead, HSF-1-mediated HSP expression following hyperthermia and heat shock appears to be mediated, in addition to HSF-1 activation, by posttranslational modifications of HSF-1 protein.

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Section: Discussionmentioning

confidence: 99%

Hyperthermia in the febrile range induces HSP72 expression proportional to exposure temperature but not to HSF-1 DNA-binding activity in human lung epithelial A549 cells

Tulapurkar

Asiegbu

Singh

et al. 2009

Cell Stress and Chaperones

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“…Cells were lysed in a passive lysis buffer (Promega), and firefly luciferase and Renilla luciferase activities were measured using the DualLuciferase Reporter Assay System (Promega). Renilla luciferase was used for normalization, and all values were further standardized to medium-treated pcDNA3-YFP-hTLR2 transfectants to determine relative luciferase units (47).…”

Section: Methodsmentioning

confidence: 99%

Inhibition of TLR2 signaling by small molecule inhibitors targeting a pocket within the TLR2 TIR domain

Mistry¹,

Laird²,

Schwarz³

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

135

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Toll-like receptor (TLR) signaling is initiated by dimerization of intracellular Toll/IL-1 receptor resistance (TIR) domains. For all TLRs except TLR3, recruitment of the adapter, myeloid differentiation primary response gene 88 (MyD88), to TLR TIR domains results in downstream signaling culminating in proinflammatory cytokine production. Therefore, blocking TLR TIR dimerization may ameliorate TLR2-mediated hyperinflammatory states. The BB loop within the TLR TIR domain is critical for mediating certain protein-protein interactions. Examination of the human TLR2 TIR domain crystal structure revealed a pocket adjacent to the highly conserved P681 and G682 BB loop residues. Using computer-aided drug design (CADD), we sought to identify a small molecule inhibitor(s) that would fit within this pocket and potentially disrupt TLR2 signaling. In silico screening identified 149 compounds and 20 US Food and Drug Administration-approved drugs based on their predicted ability to bind in the BB loop pocket. These compounds were screened in HEK293T-TLR2 transfectants for the ability to inhibit TLR2-mediated IL-8 mRNA. C 16 H 15 NO 4 (C29) was identified as a potential TLR2 inhibitor. C29, and its derivative, ortho-vanillin (o-vanillin), inhibited TLR2/1 and TLR2/6 signaling induced by synthetic and bacterial TLR2 agonists in human HEK-TLR2 and THP-1 cells, but only TLR2/1 signaling in murine macrophages. C29 failed to inhibit signaling induced by other TLR agonists and TNF-α. Mutagenesis of BB loop pocket residues revealed an indispensable role for TLR2/1, but not TLR2/6, signaling, suggesting divergent roles. Mice treated with o-vanillin exhibited reduced TLR2-induced inflammation. Our data provide proof of principle that targeting the BB loop pocket is an effective approach for identification of TLR2 signaling inhibitors.small molecule inhibitor | BB loop | TLR2 pocket | CADD T oll-like receptors (TLRs) are type I transmembrane receptors that detect conserved "pathogen-associated molecular patterns" from microbes, as well as host-derived "danger-associated molecular patterns" (1). TLR2 heterodimerizes with TLR6 or TLR1 to recognize diacyl lipopeptides or triacyl lipopeptides, respectively (2, 3), present in gram-positive and gram-negative bacteria (4-9).Ligand engagement of TLR2/1 or TLR2/6 activates the myeloid differentiation primary response gene 88 (MyD88)-dependent pathway (i.e., nuclear translocation of NF-κB, activation of MAPKs), resulting in production of proinflammatory cytokines (10). Dysregulated TLR2 signaling has been implicated in numerous diseases (e.g., sepsis, atherosclerosis, tumor metastasis, ischemia/reperfusion injury) (11)(12)(13)(14). Several inhibitors of TLR2 signaling have been developed (15-18), yet none is licensed for human use. A better understanding of the Toll/IL-1 receptor resistance (TIR) domain interactions involved in TLR2 signaling could lead to novel therapeutic agents.Both TLRs and adapter proteins contain a cytoplasmic TIR domain that mediates homotypic and heterotypic interactions ...

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“…For immunoblotting, the membranes were blocked with 5% nonfat dry milk in TTBS (25 mM Tris, pH 7.4, 0.5 M NaCl, 0.05% Tween 20) and probed using the following antibodies: Hsp70 (StressGen, Ann Arbor, MI), ␤-tubulin (Millipore/Chemicon, Bellerica, MA), HSF1, phospho-ERK, phospho-ribosome S6 kinase (RSK), and their total forms from Santa Cruz Biotechnology (Santa Cruz, CA) and total and p38␣, phospho-p38 and phospho-MAP kinase-activated protein kinase-2 (MK2) were obtained from Cell Signaling (Danvers, MA). Bands were developed using HRP-conjugated appropriate secondary antibody (Santa Cruz) and ECL detection system (Pierce, Thermo Fisher) and quantified using a gel documentation system (Fuji LAS-4000) as described earlier (33,36,37).…”

Section: Methodsmentioning

confidence: 99%

“…RNA Extraction and Quantitative Real Time PCR-Total RNA from RAW cells was isolated using a Qiagen kit, contaminating DNA eliminated using DNase I digestion, and RNA was reverse transcribed using oligo(dT) primers and a cDNA synthesis kit according to the manufacturer's protocol (Promega, Madison, WI) as we have previously described (36,37). Duplicate 25-l real time PCRs were performed in 96-well plates using a SYBR-Green reaction mix (Bio-Rad) and a Bio-Rad iCycler IQ optical module according to the supplier's protocol with the following forward and reverse primers: GAPDH, 5Ј-agcctcgtcccgtagacaaaat and 5Ј-tggcaacaatctccactttgc; and HSPA1A, 5Ј-ggccagggctggattact and 5Ј-gcaaccaccatgcaagatta.…”

Section: Methodsmentioning

confidence: 99%

Toll-like Receptor Agonists and Febrile Range Hyperthermia Synergize to Induce Heat Shock Protein 70 Expression and Extracellular Release

Gupta¹,

Cooper²,

Tulapurkar³

et al. 2013

Journal of Biological Chemistry

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Heat Shock Co-Activates Interleukin-8 Transcription

Cited by 56 publications

References 36 publications

Hyperthermia in the febrile range induces HSP72 expression proportional to exposure temperature but not to HSF-1 DNA-binding activity in human lung epithelial A549 cells

Hyperthermia in the febrile range induces HSP72 expression proportional to exposure temperature but not to HSF-1 DNA-binding activity in human lung epithelial A549 cells

Inhibition of TLR2 signaling by small molecule inhibitors targeting a pocket within the TLR2 TIR domain

Toll-like Receptor Agonists and Febrile Range Hyperthermia Synergize to Induce Heat Shock Protein 70 Expression and Extracellular Release

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