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A central function for perlecan in skeletal muscle and cardiovascular development.

Zoeller JJ, McQuillan A, Whitelock J, Ho SY, Iozzo RV - J. Cell Biol. (2008)

Bottom Line: In the perlecan morphants, primary intersegmental vessel sprouts, which develop through angiogenesis, fail to extend and show reduced protrusive activity.The phenotype is partially rescued by microinjection of human perlecan or endorepellin.These findings indicate that perlecan is essential for the integrity of somitic muscle and developmental angiogenesis and that endorepellin mediates most of these biological activities.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Anatomy, and Cell, Thomas Jefferson University, Philadelphia, PA 19107, USA.

ABSTRACT
Perlecan's developmental functions are difficult to dissect in placental animals because perlecan disruption is embryonic lethal. In contrast to mammals, cardiovascular function is not essential for early zebrafish development because the embryos obtain adequate oxygen by diffusion. In this study, we use targeted protein depletion coupled with protein-based rescue experiments to investigate the involvement of perlecan and its C-terminal domain V/endorepellin in zebrafish development. The perlecan morphants show a severe myopathy characterized by abnormal actin filament orientation and disorganized sarcomeres, suggesting an involvement of perlecan in myopathies. In the perlecan morphants, primary intersegmental vessel sprouts, which develop through angiogenesis, fail to extend and show reduced protrusive activity. Live videomicroscopy confirms the abnormal swimming pattern caused by the myopathy and anomalous head and trunk vessel circulation. The phenotype is partially rescued by microinjection of human perlecan or endorepellin. These findings indicate that perlecan is essential for the integrity of somitic muscle and developmental angiogenesis and that endorepellin mediates most of these biological activities.

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Related in: MedlinePlus

Muscular analysis in perlecan morphant embryos.(A and C) Filamentous actin confocal immunohistochemistry. Arows in C highlight clear spaces between the muscle fibers. (B and D) Corresponding DIC analysis of the trunk musculature from a control and morphant embryo at 5 dpf. (E–J) Birefringence analyses under polarizing light comparing control and morphant trunk muscle at 2–3 dpf. F, H, and J are magnified views of the boxed regions in E, G, and I, respectively. Arrows in H indicate regions of hypobirefringence. (K–N) Binding of fluorescently labeled α-bungarotoxin and fasciculin to 4-dpf control and morphant embryos as a means to examine the distribution of AChR (red; highlighted by arrowheads in K and N) and AChE (green; highlighted by arrows in L and M). Bars, 300 μm.
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fig6: Muscular analysis in perlecan morphant embryos.(A and C) Filamentous actin confocal immunohistochemistry. Arows in C highlight clear spaces between the muscle fibers. (B and D) Corresponding DIC analysis of the trunk musculature from a control and morphant embryo at 5 dpf. (E–J) Birefringence analyses under polarizing light comparing control and morphant trunk muscle at 2–3 dpf. F, H, and J are magnified views of the boxed regions in E, G, and I, respectively. Arrows in H indicate regions of hypobirefringence. (K–N) Binding of fluorescently labeled α-bungarotoxin and fasciculin to 4-dpf control and morphant embryos as a means to examine the distribution of AChR (red; highlighted by arrowheads in K and N) and AChE (green; highlighted by arrows in L and M). Bars, 300 μm.

Mentions: Next, we investigated the distribution of actin-containing filaments using fluorescently labeled phalloidin. The morphants exhibited blocky somites, with less defined chevron-shaped boundaries and often clear spaces between the muscle fibers (Fig. 6 C, arrows). The muscle bundles were often interwoven, which is better illustrated under differential interference contrast (DIC) microscopy (Fig. 6 D), as compared with the regular array of muscle bundles in the control larvae (Fig. 6, A and B).


A central function for perlecan in skeletal muscle and cardiovascular development.

Zoeller JJ, McQuillan A, Whitelock J, Ho SY, Iozzo RV - J. Cell Biol. (2008)

Muscular analysis in perlecan morphant embryos.(A and C) Filamentous actin confocal immunohistochemistry. Arows in C highlight clear spaces between the muscle fibers. (B and D) Corresponding DIC analysis of the trunk musculature from a control and morphant embryo at 5 dpf. (E–J) Birefringence analyses under polarizing light comparing control and morphant trunk muscle at 2–3 dpf. F, H, and J are magnified views of the boxed regions in E, G, and I, respectively. Arrows in H indicate regions of hypobirefringence. (K–N) Binding of fluorescently labeled α-bungarotoxin and fasciculin to 4-dpf control and morphant embryos as a means to examine the distribution of AChR (red; highlighted by arrowheads in K and N) and AChE (green; highlighted by arrows in L and M). Bars, 300 μm.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2315682&req=5

fig6: Muscular analysis in perlecan morphant embryos.(A and C) Filamentous actin confocal immunohistochemistry. Arows in C highlight clear spaces between the muscle fibers. (B and D) Corresponding DIC analysis of the trunk musculature from a control and morphant embryo at 5 dpf. (E–J) Birefringence analyses under polarizing light comparing control and morphant trunk muscle at 2–3 dpf. F, H, and J are magnified views of the boxed regions in E, G, and I, respectively. Arrows in H indicate regions of hypobirefringence. (K–N) Binding of fluorescently labeled α-bungarotoxin and fasciculin to 4-dpf control and morphant embryos as a means to examine the distribution of AChR (red; highlighted by arrowheads in K and N) and AChE (green; highlighted by arrows in L and M). Bars, 300 μm.
Mentions: Next, we investigated the distribution of actin-containing filaments using fluorescently labeled phalloidin. The morphants exhibited blocky somites, with less defined chevron-shaped boundaries and often clear spaces between the muscle fibers (Fig. 6 C, arrows). The muscle bundles were often interwoven, which is better illustrated under differential interference contrast (DIC) microscopy (Fig. 6 D), as compared with the regular array of muscle bundles in the control larvae (Fig. 6, A and B).

Bottom Line: In the perlecan morphants, primary intersegmental vessel sprouts, which develop through angiogenesis, fail to extend and show reduced protrusive activity.The phenotype is partially rescued by microinjection of human perlecan or endorepellin.These findings indicate that perlecan is essential for the integrity of somitic muscle and developmental angiogenesis and that endorepellin mediates most of these biological activities.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Anatomy, and Cell, Thomas Jefferson University, Philadelphia, PA 19107, USA.

ABSTRACT
Perlecan's developmental functions are difficult to dissect in placental animals because perlecan disruption is embryonic lethal. In contrast to mammals, cardiovascular function is not essential for early zebrafish development because the embryos obtain adequate oxygen by diffusion. In this study, we use targeted protein depletion coupled with protein-based rescue experiments to investigate the involvement of perlecan and its C-terminal domain V/endorepellin in zebrafish development. The perlecan morphants show a severe myopathy characterized by abnormal actin filament orientation and disorganized sarcomeres, suggesting an involvement of perlecan in myopathies. In the perlecan morphants, primary intersegmental vessel sprouts, which develop through angiogenesis, fail to extend and show reduced protrusive activity. Live videomicroscopy confirms the abnormal swimming pattern caused by the myopathy and anomalous head and trunk vessel circulation. The phenotype is partially rescued by microinjection of human perlecan or endorepellin. These findings indicate that perlecan is essential for the integrity of somitic muscle and developmental angiogenesis and that endorepellin mediates most of these biological activities.

Show MeSH
Related in: MedlinePlus