Investigating the Secretome

Interaction among different types of cells is a common response of the heart to injury. Interplay between various cell types constituting the heart or the vasculature occurs either through direct cell contact (eg, gap junctions or adhesion molecules) or via paracrine and autocrine action. Cardiac myocytes and fibroblasts, the primary cells that comprise the heart, as well as resident cardiac stem cells (CSCs), respond to changes in their local environment, whereas it is the cell surface that translates the extracellular signal into a cellular response through direct or indirect interactions. The main site of this response is the cell-environment interface, which includes both cell surface proteins and proteins that are secreted by cells as a reaction to these changes. Various methods have been developed to identify these subproteomes and clarify protein alterations in vivo. The ability to target and define the proteins responsible for the repair process could lead to improved therapy and to the development of potential biomarkers for disease diagnosis and prognosis. In this article, we will discuss the technical issues related to identification of 1 of these subproteomes, ie, the proteins secreted by cardiac cells as a response to the alteration in their environment caused by cardiovascular diseases.The proteins secreted by a particular type of cell, secretomes, play important roles in the regulation of many physiological processes via paracrine/autocrine mechanisms, and they are of increasing interest as potential biomarkers and therapeutic targets in diseases. The proteins released by cells into conditioned media in vitro have been studied to better understand pathological conditions and mechanisms in vivo. For damaged myocardium, current therapeutic approaches are limited, because postnatal cardiac myocytes have minimum or no regenerative capacity. Thus, the ability to regenerate the myocardium by use of cell therapy has potential, and several experimental and clinical studies have demonstrated …