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PDZK1 prevents neointima formation via suppression of breakpoint cluster region kinase in vascular smooth muscle.

Lee WR, Sacharidou A, Behling-Kelly E, Oltmann SC, Zhu W, Ahmed M, Gerard RD, Hui DY, Abe J, Shaul PW, Mineo C - PLoS ONE (2015)

Bottom Line: Tandem affinity purification-mass spectrometry revealed that PDZK1 interacts with breakpoint cluster region kinase (Bcr), which contains a C-terminal PDZ binding sequence and is known to enhance responses to PDGF in VSM.PDZK1 interaction with Bcr in VSM was demonstrated by pull-down and by coimmunoprecipitation, and the augmented proliferative response to PDGF in PDZK1-/- VSM was abrogated by Bcr depletion.Furthermore, compared with wild-type Bcr overexpression, the introduction of a Bcr mutant incapable of PDZK1 binding into VSM cells yielded an exaggerated proliferative response to PDGF.

View Article: PubMed Central - PubMed

Affiliation: Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.

ABSTRACT
Scavenger receptor class B, type I (SR-BI) and its adaptor protein PDZK1 mediate responses to HDL cholesterol in endothelium. Whether the receptor-adaptor protein tandem serves functions in other vascular cell types is unknown. The current work determined the roles of SR-BI and PDZK1 in vascular smooth muscle (VSM). To evaluate possible VSM functions of SR-BI and PDZK1 in vivo, neointima formation was assessed 21 days post-ligation in the carotid arteries of wild-type, SR-BI-/- or PDZK1-/- mice. Whereas neointima development was negligible in wild-type and SR-BI-/-, there was marked neointima formation in PDZK1-/- mice. PDZK1 expression was demonstrated in primary mouse VSM cells, and compared to wild-type cells, PDZK1-/- VSM displayed exaggerated proliferation and migration in response to platelet derived growth factor (PDGF). Tandem affinity purification-mass spectrometry revealed that PDZK1 interacts with breakpoint cluster region kinase (Bcr), which contains a C-terminal PDZ binding sequence and is known to enhance responses to PDGF in VSM. PDZK1 interaction with Bcr in VSM was demonstrated by pull-down and by coimmunoprecipitation, and the augmented proliferative response to PDGF in PDZK1-/- VSM was abrogated by Bcr depletion. Furthermore, compared with wild-type Bcr overexpression, the introduction of a Bcr mutant incapable of PDZK1 binding into VSM cells yielded an exaggerated proliferative response to PDGF. Thus, PDZK1 has novel SR-BI-independent function in VSM that affords protection from neointima formation, and this involves PDZK1 suppression of VSM cell proliferation via an inhibitory interaction with Bcr.

No MeSH data available.


Related in: MedlinePlus

PDZK1 deletion causes exaggerated carotid artery neointima formation.A, B. Male SR-BI+/+ and SR-BI-/- mice (10–12 weeks of age) underwent unilateral left carotid artery ligation for the evaluation of neointima formation. Arteries were harvested 21d later, and representative images of sections from SR-BI+/+ and SR-BI-/- mice stained with hematoxylin and eosin are shown. The scale bar indicates 100 μm. C, D. Neointima formation was also evaluated in male PDZK1+/+ and PDZK1-/- mice. Neointima is indicated by arrow. E. Summary data for intima-to-media (IM) ratio for SR-BI+/+ versus SR-BI-/-. F. Summary data for IM ratio for PDZK1+/+ versus PDZK1-/-. In E and F, values are mean±SEM, n = 7–9, *p<0.05 vs. PDZK1+/+.
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pone.0124494.g001: PDZK1 deletion causes exaggerated carotid artery neointima formation.A, B. Male SR-BI+/+ and SR-BI-/- mice (10–12 weeks of age) underwent unilateral left carotid artery ligation for the evaluation of neointima formation. Arteries were harvested 21d later, and representative images of sections from SR-BI+/+ and SR-BI-/- mice stained with hematoxylin and eosin are shown. The scale bar indicates 100 μm. C, D. Neointima formation was also evaluated in male PDZK1+/+ and PDZK1-/- mice. Neointima is indicated by arrow. E. Summary data for intima-to-media (IM) ratio for SR-BI+/+ versus SR-BI-/-. F. Summary data for IM ratio for PDZK1+/+ versus PDZK1-/-. In E and F, values are mean±SEM, n = 7–9, *p<0.05 vs. PDZK1+/+.

Mentions: To determine how SR-BI impacts neointima formation, neointima development following carotid artery ligation was evaluated in SR-BI+/+ and SR-BI-/- mice. The left common carotid arteries of male 10–12 week old mice were ligated, and twenty-one days post-ligation the arteries were harvested and vascular remodeling was assessed. In wild-type SR-BI+/+ mice, the ligation induced minimal neointima formation (Fig 1A and 1E). There was also negligible neointima development in SR-BI-/- mice (Fig 1B and 1E). Carotid artery ligations were also performed in PDZK1+/+ versus PDZK1-/- mice, and there was minimal neointima development in PDZK1+/+ (Fig 1C). In contrast, there was marked neointima formation in PDZK1-/- mice (Fig 1D). Summary data indicated that the intima-media (IM) ratio was 7.6-fold greater in PDZK1-/- versus PDZK1+/+ mice (Fig 1F). To confirm the finding of exaggerated neointima formation in PDZK1-/- carotid arteries, neointima development following femoral artery cuff placement was also evaluated (S1 Fig). Whereas minimal neointima development was observed in PDZK1+/+ mice (S1 Fig Panel A), there was marked neointima formation in PDZK1-/- mice (S1 Fig Panel B). Summary data indicated that the IM ratio was 7.2-fold greater in PDZK1-/- compared to PDZK1+/+ mice (S1 Fig Panel C), mirroring the observations made in the carotid artery.


PDZK1 prevents neointima formation via suppression of breakpoint cluster region kinase in vascular smooth muscle.

Lee WR, Sacharidou A, Behling-Kelly E, Oltmann SC, Zhu W, Ahmed M, Gerard RD, Hui DY, Abe J, Shaul PW, Mineo C - PLoS ONE (2015)

PDZK1 deletion causes exaggerated carotid artery neointima formation.A, B. Male SR-BI+/+ and SR-BI-/- mice (10–12 weeks of age) underwent unilateral left carotid artery ligation for the evaluation of neointima formation. Arteries were harvested 21d later, and representative images of sections from SR-BI+/+ and SR-BI-/- mice stained with hematoxylin and eosin are shown. The scale bar indicates 100 μm. C, D. Neointima formation was also evaluated in male PDZK1+/+ and PDZK1-/- mice. Neointima is indicated by arrow. E. Summary data for intima-to-media (IM) ratio for SR-BI+/+ versus SR-BI-/-. F. Summary data for IM ratio for PDZK1+/+ versus PDZK1-/-. In E and F, values are mean±SEM, n = 7–9, *p<0.05 vs. PDZK1+/+.
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pone.0124494.g001: PDZK1 deletion causes exaggerated carotid artery neointima formation.A, B. Male SR-BI+/+ and SR-BI-/- mice (10–12 weeks of age) underwent unilateral left carotid artery ligation for the evaluation of neointima formation. Arteries were harvested 21d later, and representative images of sections from SR-BI+/+ and SR-BI-/- mice stained with hematoxylin and eosin are shown. The scale bar indicates 100 μm. C, D. Neointima formation was also evaluated in male PDZK1+/+ and PDZK1-/- mice. Neointima is indicated by arrow. E. Summary data for intima-to-media (IM) ratio for SR-BI+/+ versus SR-BI-/-. F. Summary data for IM ratio for PDZK1+/+ versus PDZK1-/-. In E and F, values are mean±SEM, n = 7–9, *p<0.05 vs. PDZK1+/+.
Mentions: To determine how SR-BI impacts neointima formation, neointima development following carotid artery ligation was evaluated in SR-BI+/+ and SR-BI-/- mice. The left common carotid arteries of male 10–12 week old mice were ligated, and twenty-one days post-ligation the arteries were harvested and vascular remodeling was assessed. In wild-type SR-BI+/+ mice, the ligation induced minimal neointima formation (Fig 1A and 1E). There was also negligible neointima development in SR-BI-/- mice (Fig 1B and 1E). Carotid artery ligations were also performed in PDZK1+/+ versus PDZK1-/- mice, and there was minimal neointima development in PDZK1+/+ (Fig 1C). In contrast, there was marked neointima formation in PDZK1-/- mice (Fig 1D). Summary data indicated that the intima-media (IM) ratio was 7.6-fold greater in PDZK1-/- versus PDZK1+/+ mice (Fig 1F). To confirm the finding of exaggerated neointima formation in PDZK1-/- carotid arteries, neointima development following femoral artery cuff placement was also evaluated (S1 Fig). Whereas minimal neointima development was observed in PDZK1+/+ mice (S1 Fig Panel A), there was marked neointima formation in PDZK1-/- mice (S1 Fig Panel B). Summary data indicated that the IM ratio was 7.2-fold greater in PDZK1-/- compared to PDZK1+/+ mice (S1 Fig Panel C), mirroring the observations made in the carotid artery.

Bottom Line: Tandem affinity purification-mass spectrometry revealed that PDZK1 interacts with breakpoint cluster region kinase (Bcr), which contains a C-terminal PDZ binding sequence and is known to enhance responses to PDGF in VSM.PDZK1 interaction with Bcr in VSM was demonstrated by pull-down and by coimmunoprecipitation, and the augmented proliferative response to PDGF in PDZK1-/- VSM was abrogated by Bcr depletion.Furthermore, compared with wild-type Bcr overexpression, the introduction of a Bcr mutant incapable of PDZK1 binding into VSM cells yielded an exaggerated proliferative response to PDGF.

View Article: PubMed Central - PubMed

Affiliation: Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.

ABSTRACT
Scavenger receptor class B, type I (SR-BI) and its adaptor protein PDZK1 mediate responses to HDL cholesterol in endothelium. Whether the receptor-adaptor protein tandem serves functions in other vascular cell types is unknown. The current work determined the roles of SR-BI and PDZK1 in vascular smooth muscle (VSM). To evaluate possible VSM functions of SR-BI and PDZK1 in vivo, neointima formation was assessed 21 days post-ligation in the carotid arteries of wild-type, SR-BI-/- or PDZK1-/- mice. Whereas neointima development was negligible in wild-type and SR-BI-/-, there was marked neointima formation in PDZK1-/- mice. PDZK1 expression was demonstrated in primary mouse VSM cells, and compared to wild-type cells, PDZK1-/- VSM displayed exaggerated proliferation and migration in response to platelet derived growth factor (PDGF). Tandem affinity purification-mass spectrometry revealed that PDZK1 interacts with breakpoint cluster region kinase (Bcr), which contains a C-terminal PDZ binding sequence and is known to enhance responses to PDGF in VSM. PDZK1 interaction with Bcr in VSM was demonstrated by pull-down and by coimmunoprecipitation, and the augmented proliferative response to PDGF in PDZK1-/- VSM was abrogated by Bcr depletion. Furthermore, compared with wild-type Bcr overexpression, the introduction of a Bcr mutant incapable of PDZK1 binding into VSM cells yielded an exaggerated proliferative response to PDGF. Thus, PDZK1 has novel SR-BI-independent function in VSM that affords protection from neointima formation, and this involves PDZK1 suppression of VSM cell proliferation via an inhibitory interaction with Bcr.

No MeSH data available.


Related in: MedlinePlus