Genomes and Genes
AGING AND ENDOTHELIAL CELL FUNCTION
Principal Investigator: May Reed
Abstract: DESCRIPTION (provided by applicant): Angiogenesis is impaired in aging. This compromises the repair of wounds and revascularization of ischemic organs. One of the central components of age-associated impairment of angiogenesis is inhibited migration of microvascular endothelial cells (mECs). In 3-dimensional (3D) collagen, movement of mECs is regulated by matrix metalloproteinases (MMPs) associated with the cell surface (MMP2, MT1-MMP) and their primary inhibitor, TIMP2. Moreover, diminished migration and tubulogenesis by aged human mECs is associated with increased TIMP2 and decreased MMP2/MT1-MMP activity. Currently, the mechanism that mediates excess TIMP2 and deficient MMP2/MT1-MMP activity in aged human mECs is not understood;however, preliminary data implicate nitric oxide (NO) as a candidate regulatory factor. NO, a vasoactive, "upstream" modulator of TIMPs and MMPs, is decreased in aged cells and tissues. Our hypothesis is that diminished levels of NO are responsible for excess TIMP2 and deficient MMP activity that, in turn, inhibits the migration and tubulogenesis of aged mECs. Consequently, increasing NO levels in aged mECs will lead to corresponding increases in MMP activity, thereby improving migration and tubulogenesis. AIMs 1 and 2 will utilize human mECs (hmECs) from 7 young (mean age=26+6yrs) and 8 aged (mean age=67+11 yrs) donors;all cells are cultured in 3D collagen gels- a simulator of interstitial ECM in vivo. AIM 1 will define changes in synthesis and activity of MMP2/MT1-MMP/TIMP2 by hmECs in response to NO. AIM 2 will examine the functional consequences of exogenous and paracrine (from iNOS transduced fibroblasts) N)-induced changes on the ability of hmECs to migrate and undergo tubulogenesis. AIMs 3 and 4 will define NO effects on EC function and MMP2/MT1-MMP/TIMP2 activity during angiogenesis ex vivo and in vivo in young and aged F1 hybrid mice using two complementary models: AIM 3: formation of sprouts from explanted microvessels cultured ex vivo in 3D collagen, and AIMs 3b and 4: vascular ingrowth into polyvinyl alcohol (PVA) sponges implanted subcutaneously in vivo. The models of murine angiogenesis permit vascular growth to be studied and manipulated in animals that are matched in all respects except for age. In summary, this proposal will use NO to define mechanism(s) of MMP2/MT1-MMP/TIMP2 regulation and subsequent impairment of endothelial cell function in aging. The elucidation of mechanisms that regulate MMP activity in aged cells and tissues will assist the development of therapies to improve wound repair and revascularization of ischemic organs.
Funding Period: 1999-05-01 - 2010-02-28
more information: NIH RePORT
- Aging-related alterations in the extracellular matrix modulate the microenvironment and influence tumor progressionCynthia C Sprenger
Department of Medicine, Division of Gerontology, University of Washington, Seattle, WA 98104, USA
Int J Cancer 127:2739-48. 2010..Because of the tight correlation between advanced age and the prevalence of prostate cancer, we will use prostate cancer as the model throughout this minireview...
- B16/F10 tumors in aged 3D collagen in vitro simulate tumor growth and gene expression in aged mice in vivoItay Bentov
Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, WA, USA
In Vitro Cell Dev Biol Anim 49:395-9. 2013..We propose that 3D matrices from aged mice provide an in vitro model of tumor growth that correlates highly with tumor size and expression of key regulatory molecules in vivo...
- Miniaturized assays of angiogenesis in vitroMay J Reed
Department of Medicine, University of Washington, Harborview Medical Center, Seattle, WA, USA
Methods Mol Biol 843:87-98. 2012..The chapter focuses on explants derived from mice and use of a miniaturized format that permits efficient utilization of reagents, ease of processing, rapid analysis, and conventional imaging...
- Elongation and secretion of tissue inhibitor of metalloproteinases 1 by human microvascular endothelial cells cultured in collagen gels is stimulated by mitomycin cMargaret A Hamner
Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA 98104 2499, USA
Endothelium 12:97-101. 2005..These results illustrate that antiproliferative compounds should be used with caution in studies of MMP regulation by ECs...
- Culture of murine aortic explants in 3-dimensional extracellular matrix: a novel, miniaturized assay of angiogenesis in vitroMay J Reed
Department of Medicine, University of Washington, Harborview Medical Center, Box 359625, 300 Ninth Avenue, Seattle, WA 98104, USA
Microvasc Res 73:248-52. 2007..The MRSG assay, which combines low volume, physically robust gels in conjunction with mouse aortic segments, may prove to be a highly useful tool in studies of the process and control of vascular growth...
- Extracellular influences on tumour angiogenesis in the aged hostC C Sprenger
Molecular and Cellular Biology Program, University of Washington, 1959 NE Pacific, Seattle, WA 98195, USA
Br J Cancer 98:250-5. 2008..Because of the tight correlation between advanced age and development of prostate cancer, we will use prostate cancer as the model throughout this review...
- Nitric oxide effects on the function of aged cells ex vivo and in vivoMay J Reed
Department of Medicine, University of Washington, Harborview Medical Center, Seattle, WA 98104, USA
In Vivo 22:673-9. 2008..Angiogenesis is impaired in most aged tissues. Accordingly, there is great interest in interventions that improve the ability of aged cells to undergo blood vessel formation and subsequent tissue repair...
- CCL5 secreted by senescent aged fibroblasts induces proliferation of prostate epithelial cells and expression of genes that modulate angiogenesisD Eyman
Department of Medicine, Harborview Medical Center, University of Washington, Seattle, WA 98104, USA
J Cell Physiol 220:376-81. 2009..These data suggest that CCL5 is a candidate chemokine secreted by aged cells that promotes prostate growth and regulates angiogenesis...
- Collagen extracts derived from young and aged mice demonstrate different structural properties and cellular effects in three-dimensional gelsMamatha Damodarasamy
Department of Medicine, Harborview Medical Center, University of Washington, Box 359625, 325 Ninth Avenue, Seattle, WA 98104, USA
J Gerontol A Biol Sci Med Sci 65:209-18. 2010..In summary, collagen extracted from young and aged mice is an effective means to examine the influence of aging on functional properties of ECM that are relevant in vivo...