Limits...
uPARAP/Endo180 is essential for cellular uptake of collagen and promotes fibroblast collagen adhesion.

Engelholm LH, List K, Netzel-Arnett S, Cukierman E, Mitola DJ, Aaronson H, Kjøller L, Larsen JK, Yamada KM, Strickland DK, Holmbeck K, Danø K, Birkedal-Hansen H, Behrendt N, Bugge TH - J. Cell Biol. (2003)

Bottom Line: However, the molecular mechanisms governing this pathway are poorly understood.Here, we show that the urokinase plasminogen activator receptor-associated protein (uPARAP)/Endo180, a novel mesenchymally expressed member of the macrophage mannose receptor family of endocytic receptors, is a key player in this process.These studies identify a central function of uPARAP/Endo180 in cellular collagen interactions.

View Article: PubMed Central - PubMed

Affiliation: Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892, USA.

ABSTRACT
The uptake and lysosomal degradation of collagen by fibroblasts constitute a major pathway in the turnover of connective tissue. However, the molecular mechanisms governing this pathway are poorly understood. Here, we show that the urokinase plasminogen activator receptor-associated protein (uPARAP)/Endo180, a novel mesenchymally expressed member of the macrophage mannose receptor family of endocytic receptors, is a key player in this process. Fibroblasts from mice with a targeted deletion in the uPARAP/Endo180 gene displayed a near to complete abrogation of collagen endocytosis. Furthermore, these cells had diminished initial adhesion to a range of different collagens, as well as impaired migration on fibrillar collagen. These studies identify a central function of uPARAP/Endo180 in cellular collagen interactions.

Show MeSH

Related in: MedlinePlus

uPARAP/Endo180 promotes cell migration on collagen. (A) The migration of dermal fibroblasts from uPARAP/Endo180−/− (black bar) or littermate control neonates (gray bar) on total tendon collagen was tracked for 6 h by time-lapse video microscopy. Data from individual cells of each genotype were collected in parallel recordings, and the rate of migration was calculated by pooling four independent sets of experiments, each showing similar results, that included cells from a total of four different uPARAP/Endo180−/− mice and five littermate control mice. A total of 52 uPARAP/Endo180−/− cells and 82 control cells were included in the measurements. Error bars indicate the standard error of the migration rates. Asterisk, P < 0.0016. (B) Migration paths on tendon collagen from 46 individual uPARAP/Endo180−/− and 46 individual control fibroblasts selected randomly. The cells were tracked for 6 h by time-lapse microscopy. Size bar is indicated in the lower right corner of the control cell panel.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2172772&req=5

fig4: uPARAP/Endo180 promotes cell migration on collagen. (A) The migration of dermal fibroblasts from uPARAP/Endo180−/− (black bar) or littermate control neonates (gray bar) on total tendon collagen was tracked for 6 h by time-lapse video microscopy. Data from individual cells of each genotype were collected in parallel recordings, and the rate of migration was calculated by pooling four independent sets of experiments, each showing similar results, that included cells from a total of four different uPARAP/Endo180−/− mice and five littermate control mice. A total of 52 uPARAP/Endo180−/− cells and 82 control cells were included in the measurements. Error bars indicate the standard error of the migration rates. Asterisk, P < 0.0016. (B) Migration paths on tendon collagen from 46 individual uPARAP/Endo180−/− and 46 individual control fibroblasts selected randomly. The cells were tracked for 6 h by time-lapse microscopy. Size bar is indicated in the lower right corner of the control cell panel.

Mentions: Cell migration is intimately linked with adhesion to the ECM (Murphy and Gavrilovic, 1999). To directly test if uPARAP is important for cellular migration on collagen, we performed single-cell, parallel time-lapse video microscopy of matched pairs of primary dermal uPARAP/Endo180−/− and littermate control fibroblasts on a mixed fibrillar collagen matrix (Fig. 4, A and B). uPARAP/Endo180−/− cells demonstrated a significant and reproducible impairment in their migration, displaying a >30% reduction in the average migration rate. The mechanistic details of this effect await further studies. One role of uPARAP/Endo180 in cell migration may be directly related to increasing cellular adhesion. However, uPARAP/Endo180-mediated collagen internalization may also promote migration by increasing adhesion site turnover, thereby facilitating cell spreading. Finally, the interplay between uPARAP/Endo180 and integrins may influence integrin-mediated signaling.


uPARAP/Endo180 is essential for cellular uptake of collagen and promotes fibroblast collagen adhesion.

Engelholm LH, List K, Netzel-Arnett S, Cukierman E, Mitola DJ, Aaronson H, Kjøller L, Larsen JK, Yamada KM, Strickland DK, Holmbeck K, Danø K, Birkedal-Hansen H, Behrendt N, Bugge TH - J. Cell Biol. (2003)

uPARAP/Endo180 promotes cell migration on collagen. (A) The migration of dermal fibroblasts from uPARAP/Endo180−/− (black bar) or littermate control neonates (gray bar) on total tendon collagen was tracked for 6 h by time-lapse video microscopy. Data from individual cells of each genotype were collected in parallel recordings, and the rate of migration was calculated by pooling four independent sets of experiments, each showing similar results, that included cells from a total of four different uPARAP/Endo180−/− mice and five littermate control mice. A total of 52 uPARAP/Endo180−/− cells and 82 control cells were included in the measurements. Error bars indicate the standard error of the migration rates. Asterisk, P < 0.0016. (B) Migration paths on tendon collagen from 46 individual uPARAP/Endo180−/− and 46 individual control fibroblasts selected randomly. The cells were tracked for 6 h by time-lapse microscopy. Size bar is indicated in the lower right corner of the control cell panel.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2172772&req=5

fig4: uPARAP/Endo180 promotes cell migration on collagen. (A) The migration of dermal fibroblasts from uPARAP/Endo180−/− (black bar) or littermate control neonates (gray bar) on total tendon collagen was tracked for 6 h by time-lapse video microscopy. Data from individual cells of each genotype were collected in parallel recordings, and the rate of migration was calculated by pooling four independent sets of experiments, each showing similar results, that included cells from a total of four different uPARAP/Endo180−/− mice and five littermate control mice. A total of 52 uPARAP/Endo180−/− cells and 82 control cells were included in the measurements. Error bars indicate the standard error of the migration rates. Asterisk, P < 0.0016. (B) Migration paths on tendon collagen from 46 individual uPARAP/Endo180−/− and 46 individual control fibroblasts selected randomly. The cells were tracked for 6 h by time-lapse microscopy. Size bar is indicated in the lower right corner of the control cell panel.
Mentions: Cell migration is intimately linked with adhesion to the ECM (Murphy and Gavrilovic, 1999). To directly test if uPARAP is important for cellular migration on collagen, we performed single-cell, parallel time-lapse video microscopy of matched pairs of primary dermal uPARAP/Endo180−/− and littermate control fibroblasts on a mixed fibrillar collagen matrix (Fig. 4, A and B). uPARAP/Endo180−/− cells demonstrated a significant and reproducible impairment in their migration, displaying a >30% reduction in the average migration rate. The mechanistic details of this effect await further studies. One role of uPARAP/Endo180 in cell migration may be directly related to increasing cellular adhesion. However, uPARAP/Endo180-mediated collagen internalization may also promote migration by increasing adhesion site turnover, thereby facilitating cell spreading. Finally, the interplay between uPARAP/Endo180 and integrins may influence integrin-mediated signaling.

Bottom Line: However, the molecular mechanisms governing this pathway are poorly understood.Here, we show that the urokinase plasminogen activator receptor-associated protein (uPARAP)/Endo180, a novel mesenchymally expressed member of the macrophage mannose receptor family of endocytic receptors, is a key player in this process.These studies identify a central function of uPARAP/Endo180 in cellular collagen interactions.

View Article: PubMed Central - PubMed

Affiliation: Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892, USA.

ABSTRACT
The uptake and lysosomal degradation of collagen by fibroblasts constitute a major pathway in the turnover of connective tissue. However, the molecular mechanisms governing this pathway are poorly understood. Here, we show that the urokinase plasminogen activator receptor-associated protein (uPARAP)/Endo180, a novel mesenchymally expressed member of the macrophage mannose receptor family of endocytic receptors, is a key player in this process. Fibroblasts from mice with a targeted deletion in the uPARAP/Endo180 gene displayed a near to complete abrogation of collagen endocytosis. Furthermore, these cells had diminished initial adhesion to a range of different collagens, as well as impaired migration on fibrillar collagen. These studies identify a central function of uPARAP/Endo180 in cellular collagen interactions.

Show MeSH
Related in: MedlinePlus