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Crucial role of HSP90 in the Akt-dependent promotion of angiogenic-like effect of glucose-regulated protein94 (Grp94)-IgG complexes.

Tramentozzi E, Tibaldi E, Brunati AM, Pagetta A, Finotti P - J. Cell. Mol. Med. (2011)

Bottom Line: CCT failed to inhibit any morphological alteration induced by Grp94-IgG on HUVECs, on its own displaying a paradoxical angiogenic-like activity.CTT appeared to enhance the angiogenic-like effect of Grp94-IgG by increasing the rate of secretion of both HSP90 and MMP-9.Results reveal a fundamental role of HSP90 in the PI3K/Akt pathway-mediated angiogenic-like effect of Grp94-IgG, also questioning the capacity of CTT to serve as an effective inhibitor of the angiogenic effect.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmacology and Anesthesiology, University of Padova, Largo E. Meneghetti, Padova, Italy.

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PU-H71 inhibitor inhibits the secretion of MMP-9 stimulated by Grp94-IgG complexes. Media collected from cells (25 × 104) cultured in the presence of Grp94-IgG complexes (10 ng/ml) and PU-H71 (50 and 150 nM), both alone and together, were treated as specified in ‘Materials and methods’ and analysed in gel zymography for gelatinase activity. A representative gel zymography of three independent experiments is reported, showing the digestion band referred to the inactive, 94 kD MMP-9 pro-form, activated experimentally by zymography. Fifteen microlitres of media were loaded in each lane. Below is the graph with histograms representing the mean (±S.D.) of densitometric analysis of digestion bands measured in all experiments (n = 3).
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fig08: PU-H71 inhibitor inhibits the secretion of MMP-9 stimulated by Grp94-IgG complexes. Media collected from cells (25 × 104) cultured in the presence of Grp94-IgG complexes (10 ng/ml) and PU-H71 (50 and 150 nM), both alone and together, were treated as specified in ‘Materials and methods’ and analysed in gel zymography for gelatinase activity. A representative gel zymography of three independent experiments is reported, showing the digestion band referred to the inactive, 94 kD MMP-9 pro-form, activated experimentally by zymography. Fifteen microlitres of media were loaded in each lane. Below is the graph with histograms representing the mean (±S.D.) of densitometric analysis of digestion bands measured in all experiments (n = 3).

Mentions: The effective inhibition by PU-H71 of the HSP90 expression and secretion stimulated by Grp94-IgG would predict antagonism on the angiogenic-like promoting activity of Grp94-IgG. In addition, because MMP-9 is actively involved in the angiogenic process, and its stimulation by Grp94-IgG is mediated by HSP90-dependent Akt activation, it would be expected that the expression of MMP-9 were similarly inhibited by PU-H71. Experiments of zymography showed that PU-H71 at the highest concentration caused a significant reduction in the secretion of MMP-9 pro-form stimulated by Grp94-IgG (Fig. 8). This result indirectly proved that the Akt pathway was involved in the process of MMP-9 transport to the membrane and secretion from the cell that is functional to the diffusion of angiogenesis.


Crucial role of HSP90 in the Akt-dependent promotion of angiogenic-like effect of glucose-regulated protein94 (Grp94)-IgG complexes.

Tramentozzi E, Tibaldi E, Brunati AM, Pagetta A, Finotti P - J. Cell. Mol. Med. (2011)

PU-H71 inhibitor inhibits the secretion of MMP-9 stimulated by Grp94-IgG complexes. Media collected from cells (25 × 104) cultured in the presence of Grp94-IgG complexes (10 ng/ml) and PU-H71 (50 and 150 nM), both alone and together, were treated as specified in ‘Materials and methods’ and analysed in gel zymography for gelatinase activity. A representative gel zymography of three independent experiments is reported, showing the digestion band referred to the inactive, 94 kD MMP-9 pro-form, activated experimentally by zymography. Fifteen microlitres of media were loaded in each lane. Below is the graph with histograms representing the mean (±S.D.) of densitometric analysis of digestion bands measured in all experiments (n = 3).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4373444&req=5

fig08: PU-H71 inhibitor inhibits the secretion of MMP-9 stimulated by Grp94-IgG complexes. Media collected from cells (25 × 104) cultured in the presence of Grp94-IgG complexes (10 ng/ml) and PU-H71 (50 and 150 nM), both alone and together, were treated as specified in ‘Materials and methods’ and analysed in gel zymography for gelatinase activity. A representative gel zymography of three independent experiments is reported, showing the digestion band referred to the inactive, 94 kD MMP-9 pro-form, activated experimentally by zymography. Fifteen microlitres of media were loaded in each lane. Below is the graph with histograms representing the mean (±S.D.) of densitometric analysis of digestion bands measured in all experiments (n = 3).
Mentions: The effective inhibition by PU-H71 of the HSP90 expression and secretion stimulated by Grp94-IgG would predict antagonism on the angiogenic-like promoting activity of Grp94-IgG. In addition, because MMP-9 is actively involved in the angiogenic process, and its stimulation by Grp94-IgG is mediated by HSP90-dependent Akt activation, it would be expected that the expression of MMP-9 were similarly inhibited by PU-H71. Experiments of zymography showed that PU-H71 at the highest concentration caused a significant reduction in the secretion of MMP-9 pro-form stimulated by Grp94-IgG (Fig. 8). This result indirectly proved that the Akt pathway was involved in the process of MMP-9 transport to the membrane and secretion from the cell that is functional to the diffusion of angiogenesis.

Bottom Line: CCT failed to inhibit any morphological alteration induced by Grp94-IgG on HUVECs, on its own displaying a paradoxical angiogenic-like activity.CTT appeared to enhance the angiogenic-like effect of Grp94-IgG by increasing the rate of secretion of both HSP90 and MMP-9.Results reveal a fundamental role of HSP90 in the PI3K/Akt pathway-mediated angiogenic-like effect of Grp94-IgG, also questioning the capacity of CTT to serve as an effective inhibitor of the angiogenic effect.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmacology and Anesthesiology, University of Padova, Largo E. Meneghetti, Padova, Italy.

Show MeSH
Related in: MedlinePlus