application) Integrins are an important family of cell surface receptors that bind to insoluble ECM proteins and transduce cell signals involved in fundamental cellular functions. Some integrins also act as receptors for soluble ligands, such as fibrinogen and fragments of matrix proteins. Fragmented ECM proteins are known to be generated during tissue injury. The investigators hypothesize that these fragments act as unique biologically active signals capable of altering microvascular functions through their interactions. They propose that these ECM-derived signals may play an important role in the vascular response to injury. The preliminary studies show that isolated arterioles dilate in response to peptide fragments containing the RGD but not the RGE sequence. This dilatory response does not require endothelium and appears to be mediated through RGD binding to avb3. Similar dilatation was observed in response to proteolytic fragments of denatured collagen known to be generated during tissue injury, suggesting that collagen may act as an in vivo source of these ligands. Collagens, which are the most abundant matrix proteins, contain multiple RGD sequences per molecule. Proteolysis could theoretically liberate soluble RGD or non-RGD peptides which could then interact with vascular wall integrins. The investigators hypothesize that the ECM can act as a source of unique RGD or non-RGD-containing peptides capable of regulating vasomotor function.
The specific aims are: 1) Characterize the vasomotor response of isolated arterioles and intact microvascular preparations to known integrin binding peptides and collagen fragments; 2) Isolate and identify the active peptides that are generated from proteolytically cleaved denatured type I collagen; and 3) Identify intracellular signaling pathways responsible for vasoactivity. The ability of integrin binding peptides to initiate changes in cell function and elicit physiological responses is of potential therapeutic interest because integrin ligands may be useful in the manipulation of vascular function and the response to injury.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
1R01HL058690-01A1
Application #
2643114
Study Section
Experimental Cardiovascular Sciences Study Section (ECS)
Project Start
1998-04-01
Project End
2002-03-31
Budget Start
1998-04-01
Budget End
1999-03-31
Support Year
1
Fiscal Year
1998
Total Cost
Indirect Cost
Name
Texas Engineering Experiment Station
Department
Physiology
Type
Schools of Engineering
DUNS #
847205572
City
College Station
State
TX
Country
United States
Zip Code
77845
Sun, Zhe; Li, Zhaohui; Meininger, Gerald A (2012) Mechanotransduction through fibronectin-integrin focal adhesion in microvascular smooth muscle cells: is calcium essential? Am J Physiol Heart Circ Physiol 302:H1965-73
Qiu, Hongyu; Zhu, Yi; Sun, Zhe et al. (2010) Short communication: vascular smooth muscle cell stiffness as a mechanism for increased aortic stiffness with aging. Circ Res 107:615-9
Huang, Shaoxing; Sun, Zhe; Li, Zhaohui et al. (2010) Modulation of microvascular smooth muscle adhesion and mechanotransduction by integrin-linked kinase. Microcirculation 17:113-27
Sun, Zhe; Martinez-Lemus, Luis A; Hill, Michael A et al. (2008) Extracellular matrix-specific focal adhesions in vascular smooth muscle produce mechanically active adhesion sites. Am J Physiol Cell Physiol 295:C268-78
Chao, Jun-Tzu; Martinez-Lemus, Luis A; Kaufman, Stephen J et al. (2006) Modulation of alpha7-integrin-mediated adhesion and expression by platelet-derived growth factor in vascular smooth muscle cells. Am J Physiol Cell Physiol 290:C972-80
Sarin, Vandana; Gaffin, Robert D; Meininger, Gerald A et al. (2005) Arginine-glycine-aspartic acid (RGD)-containing peptides inhibit the force production of mouse papillary muscle bundles via alpha 5 beta 1 integrin. J Physiol 564:603-17
Martinez-Lemus, Luis A; Crow, Tracy; Davis, Michael J et al. (2005) alphavbeta3- and alpha5beta1-integrin blockade inhibits myogenic constriction of skeletal muscle resistance arterioles. Am J Physiol Heart Circ Physiol 289:H322-9
Neiger, Jessemy D; Crow, Tracy Y; Partridge, Charles R et al. (2005) Modulation of alpha4 integrin mRNA levels is coupled to deficits in vasomotor function in rat arterioles by allylamine. Life Sci 76:1895-905
Na, S; Sun, Z; Meininger, G A et al. (2004) On atomic force microscopy and the constitutive behavior of living cells. Biomech Model Mechanobiol 3:75-84
Chao, Jun-Tzu; Meininger, Gerald A; Patterson, Jan L et al. (2004) Regulation of alpha7-integrin expression in vascular smooth muscle by injury-induced atherosclerosis. Am J Physiol Heart Circ Physiol 287:H381-9

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