Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0151744 (myocardial ischemia)
 31,282 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Heat-shock proteins (HSPs) are an important family of endogenous protective proteins, which increase in response to myocardial ischemia and other stresses. Overexpression of HSP72 is cardioprotective. We were interested in the regulation of heat-shock factor (HSF), the transcription factor for HSP genes. Previously we have observed that the inflammatory cytokine tumor necrosis factor-alpha increases HSP72 levels and postulated that dexamethasone might effect the heat shock response. In the adult rat cardiac myocyte we found that treatment with either low (10 microM)- or high (100 microM)-dose dexamethasone activated HSF by 2-6 h as determined by gel shift assay without evidence of cytotoxicity. Although HSF activation is a key step in expression of HSP72, this may not result in an increase in HSP72. We found that 10 microM dexamethasone increased HSP72 38%, and 100 microM dexamethasone increased HSP72 62% (P < 0.05). HSP27 and HSP60 were unchanged. The selective increase in HSP72 was associated with protection of the cardiac myocytes from hypoxia and reoxygenation. We conclude that dexamethasone is a novel inducer of the heat shock response.
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PMID:Activation of HSF and selective increase in heat-shock proteins by acute dexamethasone treatment. 1074 2

Recent evidence has suggested an association between Chlamydia pneumoniae infection and coronary atherosclerosis. A significant association has also been detected between heat shock protein (HSP) 60 antibody and the severity of coronary atherosclerosis. The aim of this study was to define the relationship between instability of ischemic heart disease (IHD) and serum levels of HSP60 and C. pneumoniae antibodies. Blood samples for the measurement of serum antibody titers were obtained from 1131 patients with ischemic heart disease (65+/-9 years; male/female, 828/303) and 127 non-IHD controls with normal coronary arteries (64+/-9 years; male/female, 60/67) on the day of cardiac catheterization. The serum levels of anti-human HSP60 IgG antibody and anti-chlamydial IgM, but not IgG or IgA, antibody were significantly higher in ACS patients than in stable IHD patients or controls. These results suggest that acute C. pneumoniae infection with HSP60-related immunological responses may contribute to the pathophysiology of acute coronary syndromes.
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PMID:Acute Chlamydia pneumoniae infection with heat-shock-protein-60-related response in patients with acute coronary syndrome. 1621 93

Innate immune response after transient ischemia is the most common cause of myocardial inflammation and may contribute to injury, yet the detailed signaling mechanisms leading to such a response are not well understood. Herein we tested the hypothesis that myocardial ischemia activates interleukin receptor-associated kinase-1 (IRAK-1), a kinase critical for the innate immune signaling such as that of Toll-like receptors (TLRs), via a mechanism that involves heat shock proteins (HSPs) and TLRs. Coronary artery occlusion induced a rapid myocardial IRAK-1 activation within 30 min in wild-type (WT), TLR2(-/-), or Trif(-/-) mice, but not in TLR4(def) or MyD88(-/-) mice. HSP60 protein was markedly increased in serum or in perfusate of isolated heart following ischemia/reperfusion (I/R). In vitro, recombinant HSP60 induced IRAK-1 activation in cells derived from WT, TLR2(-/-), or Trif(-/-) mice, but not from TLR4(def) or MyD88(-/-) mice. Both myocardial ischemia- and HSP60-induced IRAK-1 activation was abolished by anti-HSP60 antibody. Moreover, HSP60 treatment of cardiomyocytes (CMs) led to marked activation of caspase-8 and -3, but not -9. Expression of dominant-negative mutant of Fas-associated death domain protein or a caspase-8 inhibitor completely blocked HSP60-induced caspase-8 activation, suggesting that HSP60 likely activates an apoptotic program via the death-receptor pathway. In vivo, I/R-induced myocardial apoptosis and cytokine expression were significantly attenuated in TLR4(def) mice or in WT mice treated with anti-HSP60 antibody compared with WT controls. Taken together, the current study demonstrates that myocardial ischemia activates an innate immune signaling via HSP60 and TLR4, which plays an important role in mediating apoptosis and inflammation during I/R.
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PMID:Myocardial ischemia activates an injurious innate immune signaling via cardiac heat shock protein 60 and Toll-like receptor 4. 2177 38