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Role of heat shock protein 70 in induction of stress fiber formation in rat arterial endothelial cells in response to stretch stress.

Luo SS, Sugimoto K, Fujii S, Takemasa T, Fu SB, Yamashita K - Acta Histochem Cytochem (2007)

Bottom Line: In contrast, treatment with quercetin, an HSP 70 inhibitor, inhibited both upregulation of endothelial HSP 70 and formation of SFs in response to tensile stress.In addition, treatment of stretched ECs with cytochalasin D, which disrupts SF formation, did not adversely affect stretch-induced upregulation of endothelial HSP 70.Our data suggest that endothelial HSP 70 plays an important role in inducing SF formation in response to tensile stress.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Anatomy, Nippon Medical School, Tokyo 113-8602, Japan.

ABSTRACT
We investigated the mechanism by which endothelial cells (ECs) resist various forms of physical stress using an experimental system consisting of rat arterial EC sheets. Formation of actin stress fibers (SFs) and expression of endothelial heat-shock stress proteins (HSPs) in response to mechanical stretch stress were assessed by immunofluorescence microscopy. Stretch stimulation increased expression of HSPs 25 and 70, but not that of HSP 90. Treatment with SB203580, a p38 MAP kinase inhibitor that acts upstream of the HSP 25 activation cascade, or with geldanamycin, an inhibitor of HSP 90, had no effect on the SF formation response to mechanical stretch stress. In contrast, treatment with quercetin, an HSP 70 inhibitor, inhibited both upregulation of endothelial HSP 70 and formation of SFs in response to tensile stress. In addition, treatment of stretched ECs with cytochalasin D, which disrupts SF formation, did not adversely affect stretch-induced upregulation of endothelial HSP 70. Our data suggest that endothelial HSP 70 plays an important role in inducing SF formation in response to tensile stress.

No MeSH data available.


Related in: MedlinePlus

HSP 70 immunohistochemistry in rat arterial ECs from Th-p (A, B) and Cil (C, D) under non-stretch-stressed (A, C) and stretch-stressed (B, D) conditions. HSP 70 expression was upregulated by application of stretch stress (30% amplitude, 1 hr) in Cil ECs (D) but not in Th-p ECs (B). The abbreviations used here are the same as those used in Fig. 2. Images A–D are shown at the same magnification; bar=20 µm.
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Figure 4: HSP 70 immunohistochemistry in rat arterial ECs from Th-p (A, B) and Cil (C, D) under non-stretch-stressed (A, C) and stretch-stressed (B, D) conditions. HSP 70 expression was upregulated by application of stretch stress (30% amplitude, 1 hr) in Cil ECs (D) but not in Th-p ECs (B). The abbreviations used here are the same as those used in Fig. 2. Images A–D are shown at the same magnification; bar=20 µm.

Mentions: Each of the endothelial HSPs examined (HSPs 25, 70, and 90) was constitutively expressed in arterial ECs in vivo at a constant level for all four anatomical locations examined (Fig. 3). The effects of stretching on expression of HSPs 25 and 70 followed one of two patterns, depending on anatomical location. In ECs from the middle parts of the abdominal aorta and the common iliac artery, expression of HSPs 25 and 70 markedly increased after stretch stimulation (Figs. 4 and 5), and the increase was greater for HSP 70 than for HSP 25. In contrast, stretching of ECs from the proximal part of the thoracic aorta and the common carotid artery caused little change in the level of expression of HSPs 25 and 70, which remained the same or slightly decreased (Figs. 4 and 5). Notably, the second group also exhibited poor formation of SFs in response to mechanical stretch stress (see Fig. 2). Endothelial HSP 90 was not upregulated by stretch stress in any of the arteries examined (Fig. 5).


Role of heat shock protein 70 in induction of stress fiber formation in rat arterial endothelial cells in response to stretch stress.

Luo SS, Sugimoto K, Fujii S, Takemasa T, Fu SB, Yamashita K - Acta Histochem Cytochem (2007)

HSP 70 immunohistochemistry in rat arterial ECs from Th-p (A, B) and Cil (C, D) under non-stretch-stressed (A, C) and stretch-stressed (B, D) conditions. HSP 70 expression was upregulated by application of stretch stress (30% amplitude, 1 hr) in Cil ECs (D) but not in Th-p ECs (B). The abbreviations used here are the same as those used in Fig. 2. Images A–D are shown at the same magnification; bar=20 µm.
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Related In: Results  -  Collection

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Figure 4: HSP 70 immunohistochemistry in rat arterial ECs from Th-p (A, B) and Cil (C, D) under non-stretch-stressed (A, C) and stretch-stressed (B, D) conditions. HSP 70 expression was upregulated by application of stretch stress (30% amplitude, 1 hr) in Cil ECs (D) but not in Th-p ECs (B). The abbreviations used here are the same as those used in Fig. 2. Images A–D are shown at the same magnification; bar=20 µm.
Mentions: Each of the endothelial HSPs examined (HSPs 25, 70, and 90) was constitutively expressed in arterial ECs in vivo at a constant level for all four anatomical locations examined (Fig. 3). The effects of stretching on expression of HSPs 25 and 70 followed one of two patterns, depending on anatomical location. In ECs from the middle parts of the abdominal aorta and the common iliac artery, expression of HSPs 25 and 70 markedly increased after stretch stimulation (Figs. 4 and 5), and the increase was greater for HSP 70 than for HSP 25. In contrast, stretching of ECs from the proximal part of the thoracic aorta and the common carotid artery caused little change in the level of expression of HSPs 25 and 70, which remained the same or slightly decreased (Figs. 4 and 5). Notably, the second group also exhibited poor formation of SFs in response to mechanical stretch stress (see Fig. 2). Endothelial HSP 90 was not upregulated by stretch stress in any of the arteries examined (Fig. 5).

Bottom Line: In contrast, treatment with quercetin, an HSP 70 inhibitor, inhibited both upregulation of endothelial HSP 70 and formation of SFs in response to tensile stress.In addition, treatment of stretched ECs with cytochalasin D, which disrupts SF formation, did not adversely affect stretch-induced upregulation of endothelial HSP 70.Our data suggest that endothelial HSP 70 plays an important role in inducing SF formation in response to tensile stress.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Anatomy, Nippon Medical School, Tokyo 113-8602, Japan.

ABSTRACT
We investigated the mechanism by which endothelial cells (ECs) resist various forms of physical stress using an experimental system consisting of rat arterial EC sheets. Formation of actin stress fibers (SFs) and expression of endothelial heat-shock stress proteins (HSPs) in response to mechanical stretch stress were assessed by immunofluorescence microscopy. Stretch stimulation increased expression of HSPs 25 and 70, but not that of HSP 90. Treatment with SB203580, a p38 MAP kinase inhibitor that acts upstream of the HSP 25 activation cascade, or with geldanamycin, an inhibitor of HSP 90, had no effect on the SF formation response to mechanical stretch stress. In contrast, treatment with quercetin, an HSP 70 inhibitor, inhibited both upregulation of endothelial HSP 70 and formation of SFs in response to tensile stress. In addition, treatment of stretched ECs with cytochalasin D, which disrupts SF formation, did not adversely affect stretch-induced upregulation of endothelial HSP 70. Our data suggest that endothelial HSP 70 plays an important role in inducing SF formation in response to tensile stress.

No MeSH data available.


Related in: MedlinePlus