Google Groups no longer supports new Usenet posts or subscriptions. Historical content remains viewable.
Dismiss
The phosphatidylserine receptor mediates phagocytosis by vascular smooth muscle cells.
3 views
Skip to first unread message
Immanuel kant
May 20, 2012, 5:11:04 PM5/20/12
to
J Pathol. 2007 Jul;212(3):249-59.
The phosphatidylserine receptor mediates phagocytosis by vascular
smooth muscle cells.
Kolb S, Vranckx R, Huisse MG, Michel JB, Meilhac O.
SourceINSERM, U698 Haematology, Bio-engineering and Cardiovascular
Remodelling, Paris F-75018, France.
Abstract
Apoptosis participates in every step of atherogenesis, but the process
of clearance of apoptotic cells by phagocytosis has been
underestimated. Rapid removal of apoptotic cells is critical for
tissue homeostasis, in order to avoid accumulation of necrotic
material and subsequent inflammation in the pathological vascular
wall. We have demonstrated by RT-PCR, western blot and
immunocytofluorescence that vascular smooth muscle cells (VSMCs)
express the phosphatidylserine receptor (PSR). We then tested the
involvement of PSR in the ability of VSMCs to bind and engulf
apoptotic cells. We used a model of senescent erythrocytes, which
expose PS after 4 days of culture (85% of cells relative to 8% in
freshly isolated erythrocytes). The pseudo-peroxidase activity of
haemoglobin contained within erythrocytes allowed us to quantify per
se both binding and phagocytosis by VSMCs. We have also shown by light
and confocal microscopy that VSMCs were able to ingest aged
erythrocytes. Addition of a blocking antibody or transfection of VSMCs
by a siRNA directed against PSR reduced the binding and engulfment of
aged erythrocytes by more than 90%. These results suggest that PSR is
involved in phagocytosis of PS-presenting cells. Incubation of aged
erythrocytes with VSMCs also significantly increased the expression of
PSR, suggesting that the tethering/ingestion of apoptotic cells
triggers this process. Immunostaining for PSR in complicated
atherosclerotic plaques shows positivity in the media and macrophage-
rich areas. The mechanisms underlying phagocytosis and involving PSR
in vivo, within the pathological arterial wall, deserve further
investigation.
Copyright (c) 2007 Pathological Society of Great Britain and Ireland.
Published by John Wiley & Sons, Ltd.
PMID: 17534843
The phosphatidylserine receptor mediates phagocytosis by vascular
smooth muscle cells.
Kolb S, Vranckx R, Huisse MG, Michel JB, Meilhac O.
SourceINSERM, U698 Haematology, Bio-engineering and Cardiovascular
Remodelling, Paris F-75018, France.
Abstract
Apoptosis participates in every step of atherogenesis, but the process
of clearance of apoptotic cells by phagocytosis has been
underestimated. Rapid removal of apoptotic cells is critical for
tissue homeostasis, in order to avoid accumulation of necrotic
material and subsequent inflammation in the pathological vascular
wall. We have demonstrated by RT-PCR, western blot and
immunocytofluorescence that vascular smooth muscle cells (VSMCs)
express the phosphatidylserine receptor (PSR). We then tested the
involvement of PSR in the ability of VSMCs to bind and engulf
apoptotic cells. We used a model of senescent erythrocytes, which
expose PS after 4 days of culture (85% of cells relative to 8% in
freshly isolated erythrocytes). The pseudo-peroxidase activity of
haemoglobin contained within erythrocytes allowed us to quantify per
se both binding and phagocytosis by VSMCs. We have also shown by light
and confocal microscopy that VSMCs were able to ingest aged
erythrocytes. Addition of a blocking antibody or transfection of VSMCs
by a siRNA directed against PSR reduced the binding and engulfment of
aged erythrocytes by more than 90%. These results suggest that PSR is
involved in phagocytosis of PS-presenting cells. Incubation of aged
erythrocytes with VSMCs also significantly increased the expression of
PSR, suggesting that the tethering/ingestion of apoptotic cells
triggers this process. Immunostaining for PSR in complicated
atherosclerotic plaques shows positivity in the media and macrophage-
rich areas. The mechanisms underlying phagocytosis and involving PSR
in vivo, within the pathological arterial wall, deserve further
investigation.
Copyright (c) 2007 Pathological Society of Great Britain and Ireland.
Published by John Wiley & Sons, Ltd.
PMID: 17534843
0 new messages