Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2007 Dec;171(6):1989-99.
doi: 10.2353/ajpath.2007.070050. Epub 2007 Nov 30.

Lipoprotein receptor-related protein-1 mediates amyloid-beta-mediated cell death of cerebrovascular cells

Micha M M Wilhelmus  1 , Irene Otte-Höller, Jos J J van Triel, Robert Veerhuis, Marion L C Maat-Schieman, Guojun Bu, Robert M W de Waal, Marcel M Verbeek
Affiliations

Lipoprotein receptor-related protein-1 mediates amyloid-beta-mediated cell death of cerebrovascular cells

Micha M M Wilhelmus et al. Am J Pathol. 2007 Dec.

Abstract

Inefficient clearance of A beta, caused by impaired blood-brain barrier crossing into the circulation, seems to be a major cause of A beta accumulation in the brain of late-onset Alzheimer's disease patients and hereditary cerebral hemorrhage with amyloidosis Dutch type. We observed association of receptor for advanced glycation end products, CD36, and low-density lipoprotein receptor (LDLR) with cerebral amyloid angiopathy in both Alzheimer's disease and hereditary cerebral hemorrhage with amyloidosis Dutch type brains and increased low-density lipoprotein receptor-related protein-1 (LRP-1) expression by perivascular cells in cerebral amyloid angiopathy. We investigated if these A beta receptors are involved in A beta internalization and in A beta-mediated cell death of human cerebrovascular cells and astrocytes. Expression of both the LRP-1 and LDLR by human brain pericytes and leptomeningeal smooth muscle cells, but not by astrocytes, increased on incubation with A beta. Receptor-associated protein specifically inhibited A beta-mediated up-regulation of LRP-1, but not of LDLR, and receptor-associated protein also decreased A beta internalization and A beta-mediated cell death. We conclude that especially LRP-1 and, to a minor extent, LDLR are involved in A beta internalization by and A beta-mediated cell death of cerebral perivascular cells. Although perivascular cells may adapt their A beta internalization capacity to the levels of A beta present, saturated LRP-1/LDLR-mediated uptake of A beta results in degeneration of perivascular cells.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Immunohistochemical staining of Aβ receptor antibodies in neocortex of control brains. Both anti-LRP-1 (A, arrow) and anti-RAGE (C, arrow) antibodies demonstrated immunoreactivity in normal medium-sized parenchymal vessels in control brains. Both anti-CD36 (B, arrow) and anti-LDLR (D, arrow) antibodies were immunoreactive in medium-sized parenchymal vessels in control brain. Original magnifications, ×250.
Figure 2
Figure 2
Immunohistochemical staining of Aβ receptor antibodies in CAA in the neocortex of AD brains. RAGE (A), CD36 (B), and LDLR (C) immunostaining was observed in CAA, whereas LRP-1 expression was increased in perivascular cells but not in CAA itself (D). E: Immunofluorescent staining of LRP-1 (green) was also observed in endothelial cells in CAA vessels (Aβ stained red). Original magnifications: ×250 (A–D); ×400 (E).
Figure 3
Figure 3
Immunohistochemical staining of Aβ receptor antibodies in classic SPs in the neocortex of AD brain. The anti-Aβ (mAb 6C6) antibody stained both classic and diffuse SPs in AD brains (A–E). CD36 (F, arrow), LRP-1 (G, arrow), megalin (H, arrow), FPRL1 (I, arrow), and APP (J, arrow) immunostaining was observed in classic SPs. Serial sections: A, F; B, G; C, H; D, I; E, J. Original magnifications, ×250.
Figure 4
Figure 4
Western blot analysis of LRP-1 and LDLR expression in cultured HBPs and astrocytes. A: HBPs and astrocytes were incubated with or without 10 μmol/L D-Aβ1-40 for 3 days at 37°C. In HBPs, expression of LRP-1, LDLR, RAGE, and CD36 was observed, and both LRP-1 and LDLR were up-regulated by incubation with 10 μmol/L D-Aβ1-40. In astrocytes expression of LRP-1, LDLR, and RAGE was observed, but Aβ did not affect receptor expression. B: Treatment of HBPs with 10 μmol/L D-Aβ1-40 resulted in LRP-1 up-regulation after 1 day and sustained until 10 days after treatment with 10 μmol/L D-Aβ1-40. C: In HBPs co-incubated with RAP (1 μmol/L) or cycloheximide (0.5 μg/ml) for 3 days at 37°C, reduction of LRP-1 up-regulation was observed, whereas LDLR expression remained unaffected. D: Similar effects on both LRP-1 and LDLR expression on HBPs were observed after incubations with Aβ1-42. E: Incubation of HBPs with Aβ1-40 had no effect on both LRP-1 and LDLR expression. F: Astrocytes incubated with 10 μmol/L of Aβ1-40, Aβ1-42, or D-Aβ1-40, demonstrated no effects on both LRP-1 and LDLR expression. G and H: Incubation of either 10 μmol/L fibrillar D-Aβ1-40 (G) or Aβ1-42 (H) resulted in increased LRP-1 expression by HBPs, whereas no differences were observed for LDLR levels. In addition, co-incubation of fibrillar Aβ with RAP or cycloheximide inhibited this effect.
Figure 5
Figure 5
Confocal laser-scanning microscopy analysis of Aβ-mediated up-regulation of LRP-1 in HBPs. HBPs incubated with 10 μmol/L D-Aβ1-40, or in combination with RAP (1 μmol/L) or cycloheximide (0.5 μg/ml) for 3 days at 37°C. Increased immunoreactivity of anti-LRP antibody (red) was observed after treatment with 10 μmol/L D-Aβ1-40, compared to control levels of LRP-1 in HBPs. Co-incubation of D-Aβ1-40 with RAP or cycloheximide demonstrated a reduced immunoreactivity of the anti-LRP-1 antibody. Nuclei are counterstained blue. Original magnifications, ×630.
Figure 6
Figure 6
Quantitative immunofluorescence analysis of LRP-1 expression in HBPs. HBPs were incubated with peptide concentrations as indicated for 3 days at 37°C, and anti-LRP-1 and anti-Aβ immunoreactivity were analyzed as described in Materials and Methods. A: Treatment with 1 to 10 μmol/L D-Aβ1-40 resulted in a dose-dependent increase in LRP-1 expression. This increased expression was antagonized by co-incubations with RAP (1 μmol/L) or cycloheximide (0.5 μg/ml). B: Co-incubations of D-Aβ1-40 with both RAP and cycloheximide had no effect on cell surface Aβ compared to D-Aβ1-40 alone. C and D: Similar effects were also observed in treatment with 1 to 10 μmol/L Aβ1-42 and in co-incubations of Aβ1-42 with RAP or cycloheximide. E: Treatment of HBPs with 10 μmol/L of fibrillar D-Aβ1-40 (F-D-Aβ1-40) resulted in increased LRP-1 expression, whereas co-incubation of fibrillar D-Aβ1-40 with either RAP or cycloheximide reduced this effect. F: In addition, co-incubation of 10 μmol/L fibrillar D-Aβ1-40 with RAP resulted in moderately decreased D-Aβ1-40 accumulation at the cell surface, compared to D-Aβ1-40 alone, whereas co-incubations with cycloheximide had no effect on accumulation of D-Aβ1-40 at the cell surface. Statistical analysis was performed using Student’s t-test. The level of significance of the difference with 10 μmol/L (F-) D-Aβ1-40 or Aβ1-42 and the combination with RAP or cycloheximide is indicated as follows: *P < 0.05, **P < 0.01, ***P < 0.001, P > 0.05 is not indicated. Mean ± SD of quadruplicates are shown.
Figure 7
Figure 7
Internalization of Aβ by HBPs. HBPs were incubated with 5 μmol/L Aβ1-40 (A) or D-Aβ1-40 (B), with or without RAP (1 μmol/L) or cycloheximide (0.5 μg/ml) for 0, 1, 4, 21, and 24 hours at 37°C, or colchicine (1 or 2 μmol/L) for 2 days at 37°C. Aβ immunoreactivity was analyzed, as described in Materials and Methods. Cell surface immunoreactivity was subtracted from overall immunoreactivity resulting in the percentage of Aβ that is internalized. A: Increasing levels of Aβ1-40 were observed in time, whereas co-incubation of 5 μmol/L Aβ1-40 with RAP or cycloheximide inhibited Aβ internalization after 24 hours, compared to Aβ1-40 alone. B: Co-incubation of D-Aβ1-40 with colchicine (2 μmol/L) completely blocked D-Aβ1-40 internalization by HBPs.
Figure 8
Figure 8
LRP antagonists reduce Aβ-mediated cell death of cerebrovascular cells. Effects of RAP or cycloheximide on cerebrovascular and astrocyte cell death after incubation with 10 μmol/L D-Aβ1-40, 10 μmol/L Aβ1-42, with or without RAP (1 μmol/L) or cycloheximide (0.5 μg/ml) for 6 days at 37°C. A: Incubation of both 10 μmol/L D-Aβ1-40 or 10 μmol/L Aβ1-42 resulted in cell death of HBPs, ∼51% and 43%, respectively. Co-incubations with either RAP or cycloheximide significantly reduced both D-Aβ1-40 and Aβ1-42-mediated cell death of HBPs. B: Astrocytes incubated with 10 μmol/L D-Aβ1-40 showed a cell death of ∼18%, whereas co-incubation with RAP or cycloheximide had no effect on cell viability compared to D-Aβ1-40 alone. Statistical analysis was performed using Student’s t-test. The level of significance of the difference with 10 μmol/L D-Aβ1-40 or Aβ1-42 and combinations with RAP or cycloheximide is indicated as follows: *P < 0.05, **P < 0.01, ***P < 0.001, P > 0.05 is not indicated. Mean ± SD are shown.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Selkoe DJ. Clearing the brain’s amyloid cobwebs. Neuron. 2001;32:177–180. - PubMed
    1. Ghiso J, Frangione B. Amyloidosis and Alzheimer’s disease. Adv Drug Deliv Rev. 2002;54:1539–1551. - PubMed
    1. Davis-Salinas J, Saporito-Irwin SM, Cotman CW, Van Nostrand WE. Amyloid beta-protein induces its own production in cultured degenerating cerebrovascular smooth muscle cells. J Neurochem. 1995;65:931–934. - PubMed
    1. Van Nostrand WE, Melchor JP, Ruffini L. Pathologic amyloid beta-protein cell surface fibril assembly on cultured human cerebrovascular smooth muscle cells. J Neurochem. 1998;70:216–223. - PubMed
    1. Verbeek MM, de Waal RM, Schipper JJ, Van Nostrand WE. Rapid degeneration of cultured human brain pericytes by amyloid beta protein. J Neurochem. 1997;68:1135–1141. - PubMed

Publication types

MeSH terms

Substances