Stress testing at the cellular and molecular level to unravel cellular dysfunction and growth factor signal transduction defects: What Molecular Cell Biology can learn from Cardiology

Summary

Clinical medicine has been revolutionized by the impact of cellular and molecular biology in the past 30 years. This article focuses on a novel approach, whereby the clinically proven and important concept of patient or organ stress testing is being applied to cellular models, thereby developing and validating novel quantitative molecular and cellular stress tests. One example is monocyte chemotaxis analysis, whereby circulating monocytes freshly isolated from peripheral blood are being tested for their migratory responsiveness towards relevant biological stimuli such as growth factors or chemokines. These stimuli are relevant for recruiting monocytes to sites of local inflammation such as during wound healing or arteriogenesis, i.e. growth of collateral arteries. Initial clinical studies to validate “ligand-induced monocyte chemotaxis” indicate that this parameter is impaired in the presence of various cardiovascular risk factors including diabetes mellitus, hypercholesterolemia or smoking. In addition, there is proof of concept that impaired monocyte chemotaxis is reversible as shown for anti-oxidants in smokers. Moreover, the parameter “ligand-induced monocyte chemotaxis” is of great relevance for basic science (including Molecular Cell Biology) as unravelling the underlying molecular mechanisms of cellular dysfunction will certainly stimulate our understanding of the molecular basis of cellular function. This article highlights the concept of stress testing in modern medicine. Cellular stress testing is introduced as a novel and intriguing approach, which was developed as bedside-to-bench. Future prospective clinical trials will have to validate the predictive value of cellular stress testing.

Keywords

Monocytes - chemotaxis - functional cell testing - functional cellular diagnostics - stress test for vascular cells

• References

• 1 Kahn BB. Type 2 diabetes: when insulin secretion fails to compensate for insulin resistance. Cell 1998; 92: 593-596.
• 2 Fletcher GF, Mills WC, Taylor WC. Update on exercise stress testing. Am Fam Physician 2006; 74: 1749-1754.
• 3 Vague P, Nguyen L. Rationale and methods for the estimation of insulin secretion in a given patient: from research to clinical practice. Diabetes 2002; 51 (Suppl. 01) S240-244.
• 4 Rosenkranz KA, Drews A. On a modified lead method for registering thoracic wall electrocardiograms during measured physical exertion. Z Kreislaufforsch 1964; 53: 615-618.
• 5 Waltenberger J, Claesson-Welsh L, Siegbahn A. et al. Different signal transduction properties of KDR and Flt1, two receptors for vascular endothelial growth factor. J Biol Chem 1994; 269: 26988-26995.
• 6 Clauss M, Weich H, Breier G. et al. The vascular endothelial growth factor receptor Flt-1 mediates biological activities. Implications for a functional role of placenta growth factor in monocyte activation and chemotaxis. J Biol Chem 1996; 271: 17629-17634.
• 7 Czepluch FS, Waltenberger J. Monocyte responsiveness towards different arteriogenic stimuli: A functional comparison of various chemoattractants and their combinations. Thromb Haemost 2006; 96: 857-858.
• 8 Sutherland DR, Anderson L, Keeney M. et al. The ISHAGE guidelines for CD34+ cell determination by flow cytometry. International Society of Hematotherapy and Graft Engineering. J Hematother 1996; 5: 213-226.
• 9 Arras M, Ito WD, Scholz D. et al. Monocyte activation in angiogenesis and collateral growth in the rabbit hindlimb. J Clin Invest 1998; 101: 40-50.
• 10 Babiak A, Schumm AM, Wangler C. et al. Coordinated activation of VEGFR-1 and VEGFR-2 is a potent arteriogenic stimulus leading to enhancement of regional perfusion. Cardiovasc Res 2004; 61: 789-795.
• 11 Deanfield JE, Halcox JP, Rabelink TJ. Endothelial function and dysfunction: testing and clinical relevance. Circulation 2007; 115: 1285-1295.
• 12 Waltenberger J. Growth factor signal transduction defects in the cardiovascular system. Cardiovasc Res 2005; 65: 574-580.
• 13 Zeiher AM, Drexler H, Saurbier B. et al. Endothelium- mediated coronary blood flow modulation in humans. Effects of age, atherosclerosis, hypercholesterolemia, and hypertension. J Clin Invest 1993; 92: 652-662.
• 14 Waltenberger J, Lange J, Kranz A. Vascular Endothelial Growth Factor-induzierte Chemotaxis von Monozyten ist bei Patienten mit Diabetes mellitus abgeschwächt. Ein potentieller Prädiktor für die individuelle angiogene Antwort. Z Kardiol 1999; 88 (Suppl. 01) 44.
• 15 Bagorda A, Mihaylov VA, Parent CA. Chemotaxis: moving forward and holding on to the past. Thromb Haemost 2006; 95: 12-21.
• 16 Siegbahn A, Hammacher A, Westermark B. et al. Differential effects of the various isoforms of plateletderived growth factor on chemotaxis of fibroblasts, monocytes, and granulocytes. J Clin Invest 1990; 85: 916-920.
• 17 Eggermann J, Kliche S, Jarmy G. et al. Endothelial progenitor cell culture and differentiation in vitro: a methodological comparison using human umbilical cord blood. Cardiovasc Res 2003; 58: 478-486.
• 18 Waltenberger J. Regenerative Cardiology: There are various ways to prosper. Thromb Haemost 2005; 94: 695-696.
• 19 Werner N, Kosiol S, Schiegl T. et al. Circulating endothelial progenitor cells and cardiovascular outcomes. N Engl J Med 2005; 353: 999-1007.
• 20 Boyden S. The chemotactic effect of mixtures of antibody and antigen on polymorphonuclear leucocytes. J Exp Med 1962; 115: 453-466.
• 21 Waltenberger J, Lange J, Kranz A. Vascular endothelial growth factor-A-induced chemotaxis of monocytes is attenuated in patients with diabetes mellitus: A potential predictor for the individual capacity to develop collaterals. Circulation 2000; 102: 185-190.
• 22 El-Ali J, Sorger PK, Jensen KF. Cells on chips. Nature 2006; 442: 403-411.
• 23 Czepluch FS, Bergler A, Waltenberger J. Monocyte recruitment is attenuated in CAD patients with hypercholesterolemia: Predictor of an impaired arteriogenic response. J Int Med 2007; 261: 201-204.
• 24 Stadler N, Eggermann J, Vöö S. et al. Smoking-induced monocyte dysfunction is reversed by vitamin C supplementation in vivo . Arterioscler Thromb Vasc Biol 2007; 27: 120-126.
• 25 Aukrust P, Yndestad A, Smith C. et al. Chemokines in cardiovascular risk prediction. Thromb Haemost 2007; 97: 748-754.