Limits...
Endothelial-dependent mechanisms regulate leukocyte transmigration: a process involving the proteasome and disruption of the vascular endothelial-cadherin complex at endothelial cell-to-cell junctions.

Allport JR, Ding H, Collins T, Gerritsen ME, Luscinskas FW - J. Exp. Med. (1997)

Bottom Line: Palambella, T.Collins. 1995.In contrast, PECAM-1, which is located at lateral junctions and is implicated in neutrophil transmigration, was not altered.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA.

ABSTRACT
Although several adhesion molecules expressed on leukocytes (beta1 and beta2 integrins, platelet endothelial cell adhesion molecule 1 [PECAM-1], and CD47) and on endothelium (intercellular adhesion molecule 1, PECAM-1) have been implicated in leukocyte transendothelial migration, less is known about the role of endothelial lateral junctions during this process. We have shown previously (Read, M.A., A.S. Neish, F.W. Luscinskas, V.J. Palambella, T. Maniatis, and T. Collins. 1995. Immunity. 2:493-506) that inhibitors of the proteasome reduce lymphocyte and neutrophil adhesion and transmigration across TNF-alpha-activated human umbilical vein endothelial cell (EC) monolayers in an in vitro flow model. The current study examined EC lateral junction proteins, principally the vascular endothelial (VE)-cadherin complex and the effects of proteasome inhibitors (MG132 and lactacystin) on lateral junctions during leukocyte adhesion, to gain a better understanding of the role of EC junctions in leukocyte transmigration. Both biochemical and indirect immunofluorescence analyses of the adherens junction zone of EC monolayers revealed that neutrophil adhesion, not transmigration, induced disruption of the VE-cadherin complex and loss of its lateral junction localization. In contrast, PECAM-1, which is located at lateral junctions and is implicated in neutrophil transmigration, was not altered. These findings identify new and interrelated endothelial-dependent mechanisms for leukocyte transmigration that involve alterations in lateral junction structure and a proteasome-dependent event(s).

Show MeSH

Related in: MedlinePlus

Colocalization of VE–cadherin, plakoglobin, and p120/p100 to lateral cell-to-cell junctions in confluent EC monolayers is not altered by  TNF-α alone or TNF-α plus MG132. Confluent cultured EC were treated with carrier (0.02% DMSO), TNF-α (4 h), or TNF-α (4 h) followed by 2 h  of incubation with MG132 (20 μM), washed, and fixed on ice with cold methanol for 5 min. Complex components were detected using specific mAb as  detailed in Materials and Methods.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2199034&req=5

Figure 3: Colocalization of VE–cadherin, plakoglobin, and p120/p100 to lateral cell-to-cell junctions in confluent EC monolayers is not altered by TNF-α alone or TNF-α plus MG132. Confluent cultured EC were treated with carrier (0.02% DMSO), TNF-α (4 h), or TNF-α (4 h) followed by 2 h of incubation with MG132 (20 μM), washed, and fixed on ice with cold methanol for 5 min. Complex components were detected using specific mAb as detailed in Materials and Methods.

Mentions: Results of the immunoprecipitation and immunoblots were supported by data obtained from indirect immunofluorescence photomicroscopy (Fig. 3). TNF-α, lactacystin, MG132, or ALLM treatments alone, or incubations for 4 h with TNF-α followed by 2 h incubations with either inhibitors or ALLM, had no effect on the localization of the components of VE–cadherin complex to the lateral junctions. The results suggest that treatment of confluent EC monolayers with TNF-α or inhibitors, alone or in combination, does not alter the biochemical composition or lateral junction localization of the VE–cadherin complex.


Endothelial-dependent mechanisms regulate leukocyte transmigration: a process involving the proteasome and disruption of the vascular endothelial-cadherin complex at endothelial cell-to-cell junctions.

Allport JR, Ding H, Collins T, Gerritsen ME, Luscinskas FW - J. Exp. Med. (1997)

Colocalization of VE–cadherin, plakoglobin, and p120/p100 to lateral cell-to-cell junctions in confluent EC monolayers is not altered by  TNF-α alone or TNF-α plus MG132. Confluent cultured EC were treated with carrier (0.02% DMSO), TNF-α (4 h), or TNF-α (4 h) followed by 2 h  of incubation with MG132 (20 μM), washed, and fixed on ice with cold methanol for 5 min. Complex components were detected using specific mAb as  detailed in Materials and Methods.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2199034&req=5

Figure 3: Colocalization of VE–cadherin, plakoglobin, and p120/p100 to lateral cell-to-cell junctions in confluent EC monolayers is not altered by TNF-α alone or TNF-α plus MG132. Confluent cultured EC were treated with carrier (0.02% DMSO), TNF-α (4 h), or TNF-α (4 h) followed by 2 h of incubation with MG132 (20 μM), washed, and fixed on ice with cold methanol for 5 min. Complex components were detected using specific mAb as detailed in Materials and Methods.
Mentions: Results of the immunoprecipitation and immunoblots were supported by data obtained from indirect immunofluorescence photomicroscopy (Fig. 3). TNF-α, lactacystin, MG132, or ALLM treatments alone, or incubations for 4 h with TNF-α followed by 2 h incubations with either inhibitors or ALLM, had no effect on the localization of the components of VE–cadherin complex to the lateral junctions. The results suggest that treatment of confluent EC monolayers with TNF-α or inhibitors, alone or in combination, does not alter the biochemical composition or lateral junction localization of the VE–cadherin complex.

Bottom Line: Palambella, T.Collins. 1995.In contrast, PECAM-1, which is located at lateral junctions and is implicated in neutrophil transmigration, was not altered.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA.

ABSTRACT
Although several adhesion molecules expressed on leukocytes (beta1 and beta2 integrins, platelet endothelial cell adhesion molecule 1 [PECAM-1], and CD47) and on endothelium (intercellular adhesion molecule 1, PECAM-1) have been implicated in leukocyte transendothelial migration, less is known about the role of endothelial lateral junctions during this process. We have shown previously (Read, M.A., A.S. Neish, F.W. Luscinskas, V.J. Palambella, T. Maniatis, and T. Collins. 1995. Immunity. 2:493-506) that inhibitors of the proteasome reduce lymphocyte and neutrophil adhesion and transmigration across TNF-alpha-activated human umbilical vein endothelial cell (EC) monolayers in an in vitro flow model. The current study examined EC lateral junction proteins, principally the vascular endothelial (VE)-cadherin complex and the effects of proteasome inhibitors (MG132 and lactacystin) on lateral junctions during leukocyte adhesion, to gain a better understanding of the role of EC junctions in leukocyte transmigration. Both biochemical and indirect immunofluorescence analyses of the adherens junction zone of EC monolayers revealed that neutrophil adhesion, not transmigration, induced disruption of the VE-cadherin complex and loss of its lateral junction localization. In contrast, PECAM-1, which is located at lateral junctions and is implicated in neutrophil transmigration, was not altered. These findings identify new and interrelated endothelial-dependent mechanisms for leukocyte transmigration that involve alterations in lateral junction structure and a proteasome-dependent event(s).

Show MeSH
Related in: MedlinePlus