Caveolae and caveolin isoforms in rat peritoneal macrophages

A. Kiss, Ágnes Turi, Nándor Müller, O. Kántor, Erzsébet Botos

Research output: Contribution to journalArticle

27 Citations (Scopus)

Abstract

Caveolea are special (highly hydrophobic) plasma membrane invaginations with a diameter of 50-100 nm. Their characterstic features are the flask- or omega-shape and the lack of basket-like coat composed of clathrin. Caveolin - an integral membrane protein - is the principal component of caveolae membranes in vivo. Multiple forms of caveolin have been identified: caveolin-lα, caveolin-lβ, caveolin-2 and caveolin-3. They differ in their specific properties and tissue distribution. In this paper we summarize the morphological and biochemical data providing strong evidence about the existence and function of caveolae in rat peritoneal macrophages. When studied electron microscopically, the surface of both resident and elicited macrophages exhibited omega- or flask-shaped plasma membrane invaginations. There was a significant difference, however, in the number of these profiles: whereas in resident cells only a small amount of them was found on the cell surface, in elicited cells they were abundantly present on the plasma membrane. Using an antibody against the VIP21/caveolin-1 isoform we showed that these plasma membrane pits were indeed caveolae. The number and the appearance of caveolae were found to be in close correlation with the functional activity of these phagocytotic cells, indicating that the formation of caveolae is a highly regulated process. Using Western' blot analysis two different proteins (∼29 and ∼20 kDa) - both labelled with anti-caveolin antibodies - were identified in resident and elicited macrophages that have been isolated from rat peritoneal cavity. The ∼20 kDa protein was labelled specifically only by anti-VIP2 l/caveolin-1, while the ∼29 kDa protein was labelled by both anti-VIP21/caveolin-1 and anti-caveolin-2 antibodies. The presence of the ∼29 kDa protein was highly characteristic of resident cells, and only a small amount of ∼20 kDa protein was detected in these cells. Elicitation has resulted in a significant increase in the amount of ∼20 kDa protein labeled only with anit-VIP2 l/caveolin-1. Our morphological (confocal and electron microscopical) studies have shown that in resident cells caveolin was present in the cytoplasm, in smaller vesicles and multivesicular bodies around the Golgi area. Only a very small amount of caveolae was found on the cell surface of these cells. In elicited macrophages, caveolae (labelled with anti-VIP21/caveolin-1 antibody) appeared in large numbers on the cell surface, but caveolin detected by anti-caveolin-2 was also found in small vesicles and multivesicular bodies. These data support the idea that the expression of the ∼29 kDa (caveolin-related) protein is insufficient for caveolae formation in resident cells, it can function as a modified, macrophage-specific caveolin-2 isoform. Our results strongly suggest that caveolin-1 plays a crucial role in the formation of caveolae: it is the amount of caveolin-1 that regulates the appearance of caveolae on the plasma membrane. Studying the endocytotic processes of resident and elicited macrophages we have found that elicited macrophages bound and internalized significantly larger amounts of fluid phase marker (HRP) and immune complex (peroxidase-antiperoxidase - PAP) than resident cells. Serial section analysis, double labelled immunocytochemistry, and filipin treatment were used to demonstrate that caveolae can pinch off from the plasma membrane and can take part in endocytotic processes as alternative carriers in elicited macrophages.

Original languageEnglish
Pages (from-to)75-93
Number of pages19
JournalMicron
Volume33
Issue number1
DOIs
Publication statusPublished - 2002

Fingerprint

Caveolins
Caveolae
macrophages
Macrophages
Caveolin 1
Peritoneal Macrophages
rats
Rats
Protein Isoforms
Caveolin 2
Cell membranes
Proteins
cells
Antibodies
membranes
proteins
Cell Membrane
antibodies
Multivesicular Bodies
flasks

Keywords

  • Caveolae
  • Caveolae-rich macrophages
  • Caveolin
  • Caveolin isoforms
  • Endocytosis
  • Resident and elicited macrophages

ASJC Scopus subject areas

  • Cell Biology
  • Materials Science(all)
  • Instrumentation

Cite this

Caveolae and caveolin isoforms in rat peritoneal macrophages. / Kiss, A.; Turi, Ágnes; Müller, Nándor; Kántor, O.; Botos, Erzsébet.

In: Micron, Vol. 33, No. 1, 2002, p. 75-93.

Research output: Contribution to journalArticle

Kiss, A. ; Turi, Ágnes ; Müller, Nándor ; Kántor, O. ; Botos, Erzsébet. / Caveolae and caveolin isoforms in rat peritoneal macrophages. In: Micron. 2002 ; Vol. 33, No. 1. pp. 75-93.
@article{daeff30d1eb34da197deb78c70ca57ca,
title = "Caveolae and caveolin isoforms in rat peritoneal macrophages",
abstract = "Caveolea are special (highly hydrophobic) plasma membrane invaginations with a diameter of 50-100 nm. Their characterstic features are the flask- or omega-shape and the lack of basket-like coat composed of clathrin. Caveolin - an integral membrane protein - is the principal component of caveolae membranes in vivo. Multiple forms of caveolin have been identified: caveolin-lα, caveolin-lβ, caveolin-2 and caveolin-3. They differ in their specific properties and tissue distribution. In this paper we summarize the morphological and biochemical data providing strong evidence about the existence and function of caveolae in rat peritoneal macrophages. When studied electron microscopically, the surface of both resident and elicited macrophages exhibited omega- or flask-shaped plasma membrane invaginations. There was a significant difference, however, in the number of these profiles: whereas in resident cells only a small amount of them was found on the cell surface, in elicited cells they were abundantly present on the plasma membrane. Using an antibody against the VIP21/caveolin-1 isoform we showed that these plasma membrane pits were indeed caveolae. The number and the appearance of caveolae were found to be in close correlation with the functional activity of these phagocytotic cells, indicating that the formation of caveolae is a highly regulated process. Using Western' blot analysis two different proteins (∼29 and ∼20 kDa) - both labelled with anti-caveolin antibodies - were identified in resident and elicited macrophages that have been isolated from rat peritoneal cavity. The ∼20 kDa protein was labelled specifically only by anti-VIP2 l/caveolin-1, while the ∼29 kDa protein was labelled by both anti-VIP21/caveolin-1 and anti-caveolin-2 antibodies. The presence of the ∼29 kDa protein was highly characteristic of resident cells, and only a small amount of ∼20 kDa protein was detected in these cells. Elicitation has resulted in a significant increase in the amount of ∼20 kDa protein labeled only with anit-VIP2 l/caveolin-1. Our morphological (confocal and electron microscopical) studies have shown that in resident cells caveolin was present in the cytoplasm, in smaller vesicles and multivesicular bodies around the Golgi area. Only a very small amount of caveolae was found on the cell surface of these cells. In elicited macrophages, caveolae (labelled with anti-VIP21/caveolin-1 antibody) appeared in large numbers on the cell surface, but caveolin detected by anti-caveolin-2 was also found in small vesicles and multivesicular bodies. These data support the idea that the expression of the ∼29 kDa (caveolin-related) protein is insufficient for caveolae formation in resident cells, it can function as a modified, macrophage-specific caveolin-2 isoform. Our results strongly suggest that caveolin-1 plays a crucial role in the formation of caveolae: it is the amount of caveolin-1 that regulates the appearance of caveolae on the plasma membrane. Studying the endocytotic processes of resident and elicited macrophages we have found that elicited macrophages bound and internalized significantly larger amounts of fluid phase marker (HRP) and immune complex (peroxidase-antiperoxidase - PAP) than resident cells. Serial section analysis, double labelled immunocytochemistry, and filipin treatment were used to demonstrate that caveolae can pinch off from the plasma membrane and can take part in endocytotic processes as alternative carriers in elicited macrophages.",
keywords = "Caveolae, Caveolae-rich macrophages, Caveolin, Caveolin isoforms, Endocytosis, Resident and elicited macrophages",
author = "A. Kiss and {\'A}gnes Turi and N{\'a}ndor M{\"u}ller and O. K{\'a}ntor and Erzs{\'e}bet Botos",
year = "2002",
doi = "10.1016/S0968-4328(00)00100-1",
language = "English",
volume = "33",
pages = "75--93",
journal = "Micron",
issn = "0968-4328",
publisher = "Elsevier Limited",
number = "1",

}

TY - JOUR

T1 - Caveolae and caveolin isoforms in rat peritoneal macrophages

AU - Kiss, A.

AU - Turi, Ágnes

AU - Müller, Nándor

AU - Kántor, O.

AU - Botos, Erzsébet

PY - 2002

Y1 - 2002

N2 - Caveolea are special (highly hydrophobic) plasma membrane invaginations with a diameter of 50-100 nm. Their characterstic features are the flask- or omega-shape and the lack of basket-like coat composed of clathrin. Caveolin - an integral membrane protein - is the principal component of caveolae membranes in vivo. Multiple forms of caveolin have been identified: caveolin-lα, caveolin-lβ, caveolin-2 and caveolin-3. They differ in their specific properties and tissue distribution. In this paper we summarize the morphological and biochemical data providing strong evidence about the existence and function of caveolae in rat peritoneal macrophages. When studied electron microscopically, the surface of both resident and elicited macrophages exhibited omega- or flask-shaped plasma membrane invaginations. There was a significant difference, however, in the number of these profiles: whereas in resident cells only a small amount of them was found on the cell surface, in elicited cells they were abundantly present on the plasma membrane. Using an antibody against the VIP21/caveolin-1 isoform we showed that these plasma membrane pits were indeed caveolae. The number and the appearance of caveolae were found to be in close correlation with the functional activity of these phagocytotic cells, indicating that the formation of caveolae is a highly regulated process. Using Western' blot analysis two different proteins (∼29 and ∼20 kDa) - both labelled with anti-caveolin antibodies - were identified in resident and elicited macrophages that have been isolated from rat peritoneal cavity. The ∼20 kDa protein was labelled specifically only by anti-VIP2 l/caveolin-1, while the ∼29 kDa protein was labelled by both anti-VIP21/caveolin-1 and anti-caveolin-2 antibodies. The presence of the ∼29 kDa protein was highly characteristic of resident cells, and only a small amount of ∼20 kDa protein was detected in these cells. Elicitation has resulted in a significant increase in the amount of ∼20 kDa protein labeled only with anit-VIP2 l/caveolin-1. Our morphological (confocal and electron microscopical) studies have shown that in resident cells caveolin was present in the cytoplasm, in smaller vesicles and multivesicular bodies around the Golgi area. Only a very small amount of caveolae was found on the cell surface of these cells. In elicited macrophages, caveolae (labelled with anti-VIP21/caveolin-1 antibody) appeared in large numbers on the cell surface, but caveolin detected by anti-caveolin-2 was also found in small vesicles and multivesicular bodies. These data support the idea that the expression of the ∼29 kDa (caveolin-related) protein is insufficient for caveolae formation in resident cells, it can function as a modified, macrophage-specific caveolin-2 isoform. Our results strongly suggest that caveolin-1 plays a crucial role in the formation of caveolae: it is the amount of caveolin-1 that regulates the appearance of caveolae on the plasma membrane. Studying the endocytotic processes of resident and elicited macrophages we have found that elicited macrophages bound and internalized significantly larger amounts of fluid phase marker (HRP) and immune complex (peroxidase-antiperoxidase - PAP) than resident cells. Serial section analysis, double labelled immunocytochemistry, and filipin treatment were used to demonstrate that caveolae can pinch off from the plasma membrane and can take part in endocytotic processes as alternative carriers in elicited macrophages.

AB - Caveolea are special (highly hydrophobic) plasma membrane invaginations with a diameter of 50-100 nm. Their characterstic features are the flask- or omega-shape and the lack of basket-like coat composed of clathrin. Caveolin - an integral membrane protein - is the principal component of caveolae membranes in vivo. Multiple forms of caveolin have been identified: caveolin-lα, caveolin-lβ, caveolin-2 and caveolin-3. They differ in their specific properties and tissue distribution. In this paper we summarize the morphological and biochemical data providing strong evidence about the existence and function of caveolae in rat peritoneal macrophages. When studied electron microscopically, the surface of both resident and elicited macrophages exhibited omega- or flask-shaped plasma membrane invaginations. There was a significant difference, however, in the number of these profiles: whereas in resident cells only a small amount of them was found on the cell surface, in elicited cells they were abundantly present on the plasma membrane. Using an antibody against the VIP21/caveolin-1 isoform we showed that these plasma membrane pits were indeed caveolae. The number and the appearance of caveolae were found to be in close correlation with the functional activity of these phagocytotic cells, indicating that the formation of caveolae is a highly regulated process. Using Western' blot analysis two different proteins (∼29 and ∼20 kDa) - both labelled with anti-caveolin antibodies - were identified in resident and elicited macrophages that have been isolated from rat peritoneal cavity. The ∼20 kDa protein was labelled specifically only by anti-VIP2 l/caveolin-1, while the ∼29 kDa protein was labelled by both anti-VIP21/caveolin-1 and anti-caveolin-2 antibodies. The presence of the ∼29 kDa protein was highly characteristic of resident cells, and only a small amount of ∼20 kDa protein was detected in these cells. Elicitation has resulted in a significant increase in the amount of ∼20 kDa protein labeled only with anit-VIP2 l/caveolin-1. Our morphological (confocal and electron microscopical) studies have shown that in resident cells caveolin was present in the cytoplasm, in smaller vesicles and multivesicular bodies around the Golgi area. Only a very small amount of caveolae was found on the cell surface of these cells. In elicited macrophages, caveolae (labelled with anti-VIP21/caveolin-1 antibody) appeared in large numbers on the cell surface, but caveolin detected by anti-caveolin-2 was also found in small vesicles and multivesicular bodies. These data support the idea that the expression of the ∼29 kDa (caveolin-related) protein is insufficient for caveolae formation in resident cells, it can function as a modified, macrophage-specific caveolin-2 isoform. Our results strongly suggest that caveolin-1 plays a crucial role in the formation of caveolae: it is the amount of caveolin-1 that regulates the appearance of caveolae on the plasma membrane. Studying the endocytotic processes of resident and elicited macrophages we have found that elicited macrophages bound and internalized significantly larger amounts of fluid phase marker (HRP) and immune complex (peroxidase-antiperoxidase - PAP) than resident cells. Serial section analysis, double labelled immunocytochemistry, and filipin treatment were used to demonstrate that caveolae can pinch off from the plasma membrane and can take part in endocytotic processes as alternative carriers in elicited macrophages.

KW - Caveolae

KW - Caveolae-rich macrophages

KW - Caveolin

KW - Caveolin isoforms

KW - Endocytosis

KW - Resident and elicited macrophages

UR - http://www.scopus.com/inward/record.url?scp=0036028088&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0036028088&partnerID=8YFLogxK

U2 - 10.1016/S0968-4328(00)00100-1

DO - 10.1016/S0968-4328(00)00100-1

M3 - Article

C2 - 11473817

AN - SCOPUS:0036028088

VL - 33

SP - 75

EP - 93

JO - Micron

JF - Micron

SN - 0968-4328

IS - 1

ER -