Cell biology Essay Example | Topics and Well Written Essays - 1750 words

Cell biology - Essay Example 2010). Without ECM, higher life forms such as mammals, or truly any multi-cellular organism, could not possibly exist. When issues occur with the ECM, though, many problems can then arise. This is seen through the role of the ECM in two pathological states: healing after myocardial infarction, and the degenerative phase of multiple sclerosis. Extracellular Matrix in Healthy Mammals The definition of ECM is extremely broad, now more so than in past years. As it is currently defined in the scientific literature, ECM includes â€Å"all secreted molecules that are immobilized outside cells† (van Horssen et al. 2007). Every body tissue has ECM between the cells. In every case, the ECM plays some vital role in the functioning of that tissue. For example, the ECM of the lens of the eyes is responsible for cellular contraction. Cellular contraction, in turn, is what regulates growth rate of the cells on the surface of the eye (Wormstone 2004). The ECM of the periodontal ligament, comm only known as the gum between the jawbone and teeth, is extremely strong. Without it, the teeth would not be able to remain attached to the jawbone, which is vital to the development and maintenance of the bony jaw. This tissue gains such strength mainly through the levels of the collagen type I protein, which are extremely high in the ECM of the periodontal ligament (Bildt et al. 2009). One specialized type of ECM is the the basement membrane. Recently, the role of the basement membrane has been expanded past its previous place as a simple structural feature. This membrane has been shown to be an extremely important regulator of cell behaviour. It helps control tissue compartmentalization and â€Å"sends signals to epithelial cells about the external microenvironment†, telling the cells where to grown and how (Kalluri 2003). Balance between creation of new extracellular matrix and its degradation is required for the maintenance of healthy body tissues. This is accomplished t hrough production of matrix metalloproteinases, or MMPs, which are enzymes produced to break down this matrix. The cells which produce these MMPs are known as fibroblasts. Conversely, fibroblasts are also responsible for the synthesis of tissue inhibitors of metalloproteinases. These inhibitors, known as TIMPs, unsurprisingly impede the degradation activity of the MMPs (Bildt et al. 2009). ECM is also responsible for another process in the maintenance of healthy tissue: apoptosis. ECM regulates apoptosis, or programmed cell death, through intracellular signalling (van Horssen et al. 2007). Extracellular matrix could be used as biological scaffolding material for regenerative medicine (Badylak et al. 2009). It can be â€Å"decellularized† and the ECM alone used to support new transplanted cells (Soto-Gutierrez et al. 2010). Also relevant to regenerative medicine is the fact that ECM has â€Å"constructive remodeling† capability, though the mechanism behind this is not y et fully understood (Badylak et al. 2009) ECM seems like the Holy Grail of biological scaffolding, as it can be constructed and then completely degraded through â€Å"bioactive molecules† that are produced naturally within the body (Badylak 2007). Functioning of the ECM in Disease States With the extremely broad and vital roles played by the