Platelet-Derived Growth Factor, Transforming Growth Factor-β and Connective Tissue Growth Factor

Abstract

Cell-to-cell communication determines the compostition and hence function of the airways of the lung in health. Conversely, altered balances of cytokines, either primary or secondary are thought to play a determining role in acute and chronic pathological disorders. The protein cytokines are a unique group of extracellular signalling molecules with critical roles in these processes. Cytokines (also termed growth factors) are pleiotrophic molecules produced ubiquitously and which act on a wide array of target cells. They modulate a wide array of cellular functions including growth (stimulation or inhibition), differentiation, survival and a wide range of phenotypic expression. Although generally small multimeric proteins, the cytokines are considerably larger than other signalling molecules such as the kinins, prostaglandins, leukotrienes and other molecules involved in modulating cell phenotype.