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Heat shock protein 90 inhibition abrogates TLR4-mediated NF-κB activity and reduces renal ischemia-reperfusion injury.

O'Neill S, Humphries D, Tse G, Marson LP, Dhaliwal K, Hughes J, Ross JA, Wigmore SJ, Harrison EM - Sci Rep (2015)

Bottom Line: Heat shock protein 90 (Hsp90) inhibition is a potential strategy to reduce IRI, and AT13387 is a novel Hsp90 inhibitor with low toxicity.In vitro, AT13387-treatment resulted in breakdown of IκB kinase, which abolished TLR4-mediated NF-κB activation by hyaluronan.The mechanism of protection may involve breakdown of IκB kinase and repression of TLR4-mediated NF-κB inflammatory activity.

View Article: PubMed Central - PubMed

Affiliation: MRC Centre for Inflammation Research, University of Edinburgh, Edinburgh, EH16 4SA.

ABSTRACT
Renal ischemia-reperfusion injury (IRI) is a common cause of acute kidney injury. Toll-like receptor 4 (TLR4) mediates sterile inflammation following renal IRI. Heat shock protein 90 (Hsp90) inhibition is a potential strategy to reduce IRI, and AT13387 is a novel Hsp90 inhibitor with low toxicity. This study assessed if pre-treatment with AT13387 could reduce renal IRI and established if the mechanism of protection involved a reduction in inflammatory signalling. Mice were pre-treated with AT13387 prior to renal IRI. 24 h later, renal function was determined by serum creatinine, kidney damage by tubular necrosis score, renal TLR4 expression by PCR and inflammation by cytokine array. In vitro, human embryonic kidney cells were co-transfected to express TLR4 and a secreted alkaline phosphatase NF-κB reporter. Cells were pre-treated with AT13387 and exposed to endotoxin-free hyaluronan to stimulate sterile TLR4-specific NF-κB inflammatory activation. Following renal IRI, AT13387 significantly reduced serum creatinine, tubular necrosis, TLR4 expression and NF-κB-dependent chemokines. In vitro, AT13387-treatment resulted in breakdown of IκB kinase, which abolished TLR4-mediated NF-κB activation by hyaluronan. AT13387 is a new agent with translational potential that reduces renal IRI. The mechanism of protection may involve breakdown of IκB kinase and repression of TLR4-mediated NF-κB inflammatory activity.

No MeSH data available.


Related in: MedlinePlus

Renal cytokine expression following AT13387 or vehicle pre-treatment and 24 h following renal IRI in FVB/n mice.FVB/n mice were pre-treated with AT13387 or 2HβC vehicle (n = 4 per group) and underwent renal IRI as per Fig. 1. Following 24 h of recovery, the left kidney was harvested and snap frozen. Protein lysates were later prepared and an array panel was used to determine cytokine expression. The grid describes the cytokines assessed (right panel). A representative array is shown (upper left panel). Mean gray values were quantified using Image J and were used to reflect CXCL1 and CXCL2 expression. Results are presented in a standard boxplot with individual results jittered (lower left panel). *p < 0.05 vs. 2HβC vehicle, t-test.
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f3: Renal cytokine expression following AT13387 or vehicle pre-treatment and 24 h following renal IRI in FVB/n mice.FVB/n mice were pre-treated with AT13387 or 2HβC vehicle (n = 4 per group) and underwent renal IRI as per Fig. 1. Following 24 h of recovery, the left kidney was harvested and snap frozen. Protein lysates were later prepared and an array panel was used to determine cytokine expression. The grid describes the cytokines assessed (right panel). A representative array is shown (upper left panel). Mean gray values were quantified using Image J and were used to reflect CXCL1 and CXCL2 expression. Results are presented in a standard boxplot with individual results jittered (lower left panel). *p < 0.05 vs. 2HβC vehicle, t-test.

Mentions: On PCR analysis, in comparison to vehicle, AT13387 pre-treatment in FVB/n mice significantly reduced renal TLR4 expression 24 h following renal IRI (AT13387 vs. Vehicle, p < 0.01, Mann-Whitney U test) (Fig. 2). On cytokine array panel, in comparison to vehicle, AT13387 pre-treatment in FVB/n mice also reduced renal expression of chemokine (C-X-C motif) ligand 1 (CXCL1) and chemokine (C-X-C motif) ligand 2 (CXCL2) 24 h following renal IRI (AT13387 vs. 2HβC vehicle, p < 0.05, t-test) (Fig. 3). There were no other significant differences in cytokine or chemokine expression.


Heat shock protein 90 inhibition abrogates TLR4-mediated NF-κB activity and reduces renal ischemia-reperfusion injury.

O'Neill S, Humphries D, Tse G, Marson LP, Dhaliwal K, Hughes J, Ross JA, Wigmore SJ, Harrison EM - Sci Rep (2015)

Renal cytokine expression following AT13387 or vehicle pre-treatment and 24 h following renal IRI in FVB/n mice.FVB/n mice were pre-treated with AT13387 or 2HβC vehicle (n = 4 per group) and underwent renal IRI as per Fig. 1. Following 24 h of recovery, the left kidney was harvested and snap frozen. Protein lysates were later prepared and an array panel was used to determine cytokine expression. The grid describes the cytokines assessed (right panel). A representative array is shown (upper left panel). Mean gray values were quantified using Image J and were used to reflect CXCL1 and CXCL2 expression. Results are presented in a standard boxplot with individual results jittered (lower left panel). *p < 0.05 vs. 2HβC vehicle, t-test.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4528191&req=5

f3: Renal cytokine expression following AT13387 or vehicle pre-treatment and 24 h following renal IRI in FVB/n mice.FVB/n mice were pre-treated with AT13387 or 2HβC vehicle (n = 4 per group) and underwent renal IRI as per Fig. 1. Following 24 h of recovery, the left kidney was harvested and snap frozen. Protein lysates were later prepared and an array panel was used to determine cytokine expression. The grid describes the cytokines assessed (right panel). A representative array is shown (upper left panel). Mean gray values were quantified using Image J and were used to reflect CXCL1 and CXCL2 expression. Results are presented in a standard boxplot with individual results jittered (lower left panel). *p < 0.05 vs. 2HβC vehicle, t-test.
Mentions: On PCR analysis, in comparison to vehicle, AT13387 pre-treatment in FVB/n mice significantly reduced renal TLR4 expression 24 h following renal IRI (AT13387 vs. Vehicle, p < 0.01, Mann-Whitney U test) (Fig. 2). On cytokine array panel, in comparison to vehicle, AT13387 pre-treatment in FVB/n mice also reduced renal expression of chemokine (C-X-C motif) ligand 1 (CXCL1) and chemokine (C-X-C motif) ligand 2 (CXCL2) 24 h following renal IRI (AT13387 vs. 2HβC vehicle, p < 0.05, t-test) (Fig. 3). There were no other significant differences in cytokine or chemokine expression.

Bottom Line: Heat shock protein 90 (Hsp90) inhibition is a potential strategy to reduce IRI, and AT13387 is a novel Hsp90 inhibitor with low toxicity.In vitro, AT13387-treatment resulted in breakdown of IκB kinase, which abolished TLR4-mediated NF-κB activation by hyaluronan.The mechanism of protection may involve breakdown of IκB kinase and repression of TLR4-mediated NF-κB inflammatory activity.

View Article: PubMed Central - PubMed

Affiliation: MRC Centre for Inflammation Research, University of Edinburgh, Edinburgh, EH16 4SA.

ABSTRACT
Renal ischemia-reperfusion injury (IRI) is a common cause of acute kidney injury. Toll-like receptor 4 (TLR4) mediates sterile inflammation following renal IRI. Heat shock protein 90 (Hsp90) inhibition is a potential strategy to reduce IRI, and AT13387 is a novel Hsp90 inhibitor with low toxicity. This study assessed if pre-treatment with AT13387 could reduce renal IRI and established if the mechanism of protection involved a reduction in inflammatory signalling. Mice were pre-treated with AT13387 prior to renal IRI. 24 h later, renal function was determined by serum creatinine, kidney damage by tubular necrosis score, renal TLR4 expression by PCR and inflammation by cytokine array. In vitro, human embryonic kidney cells were co-transfected to express TLR4 and a secreted alkaline phosphatase NF-κB reporter. Cells were pre-treated with AT13387 and exposed to endotoxin-free hyaluronan to stimulate sterile TLR4-specific NF-κB inflammatory activation. Following renal IRI, AT13387 significantly reduced serum creatinine, tubular necrosis, TLR4 expression and NF-κB-dependent chemokines. In vitro, AT13387-treatment resulted in breakdown of IκB kinase, which abolished TLR4-mediated NF-κB activation by hyaluronan. AT13387 is a new agent with translational potential that reduces renal IRI. The mechanism of protection may involve breakdown of IκB kinase and repression of TLR4-mediated NF-κB inflammatory activity.

No MeSH data available.


Related in: MedlinePlus