Col4a1 mutation in mice causes defects in vascular function and low blood pressure associated with reduced red blood cell volume

Van Agtmael, T. , Bailey, M. A., Schlotzer-Schrehardt, U., Craigie, E., Jackson, I. J., Brownstein, D. G., Megson, I. L. and Mullins, J. J. (2010) Col4a1 mutation in mice causes defects in vascular function and low blood pressure associated with reduced red blood cell volume. Human Molecular Genetics, 19(6), pp. 1119-1128. (doi:10.1093/hmg/ddp584)

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Publisher's URL: http://dx.doi.org/10.1093/hmg/ddp584

Abstract

Collagen type IV is the major structural component of the basement membrane and COL4A1 mutations cause adult small vessel disease, familial porencephaly and hereditary angiopathy with nephropathy aneurysm and cramps (HANAC) syndrome. Here, we show that animals with a Col4a1 missense mutation (Col4a1+/Raw) display focal detachment of the endothelium from the media and age-dependent defects in vascular function including a reduced response to nor-epinephrine. Age-dependent hypersensitivity to acetylcholine is abolished by inhibition of nitric oxide synthase (NOS) activity, indicating that Col4a1 mutations affect vasorelaxation mediated by endothelium-derived nitric oxide (NO). These defects are associated with a reduction in basal NOS activity and the development of heightened NO sensitivity of the smooth muscle. The vascular function defects are physiologically relevant as they maintain in part the hypotension in mutant animals, which is primarily associated with a reduced red blood cell volume due to a reduction in red blood cell number, rather than defects in kidney function. To understand the molecular mechanism underlying these vascular defects, we examined the deposition of collagen type IV in the basement membrane, and found it to be defective. Interestingly, this mutation also leads to activation of the unfolded protein response. In summary, our results indicate that mutations in COL4A1 result in a complex vascular phenotype encompassing defects in maintenance of vascular tone, endothelial cell function and blood pressure regulation.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Van Agtmael, Dr Tom
Authors: Van Agtmael, T., Bailey, M. A., Schlotzer-Schrehardt, U., Craigie, E., Jackson, I. J., Brownstein, D. G., Megson, I. L., and Mullins, J. J.
Subjects:Q Science > QH Natural history > QH426 Genetics
Q Science > QH Natural history > QH301 Biology
College/School:College of Medical Veterinary and Life Sciences
College of Medical Veterinary and Life Sciences > Institute of Cardiovascular and Medical Sciences
Journal Name:Human Molecular Genetics
Publisher:Oxford University Press
ISSN:0964-6906
ISSN (Online):1460-2083
Published Online:07 January 2010
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Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
471511Collagen type IV in vascular biologyTom Van AgtmaelMedical Research Council (MRC)G0601268Institute of Cardiovascular and Medical Sciences