Effects of World Trade Center Particulate Matter From September 11, 2001 on Biochemical Pathways Associated with Apoptosis and Cell Viability

The dust that resulted from the collapse of the World Trade Center (WTC) towers on September 11th, 2001 contained organic and inorganic compounds. The survivors and first responders were breathing these compounds while fleeing and rescuing others. Some of the particles that were inhaled were small enough to affect the alveolar region of the lungs. This study looks at the effect that World Trade Center dust has on MRC-5 human lung fibroblasts. Cell viability is observed over time using an alamarBlue® assay. Previous studies have shown that MRC-5 cells that are exposed to WTC dust lose viability after 24 hours (Hernandez, Choi, & DiLorenzo, 2012). However, these studies only observed the viability of the cells at one time point. This study is different in that it shows that some viability of the cells that were exposed to WTC dust is regained at 48 hours. Western blots are performed to determine if the cells are producing proteins that would indicate apoptosis due to exposure to the dust. Western blots are performed to also observe the effect that the dust is having on the mitogen-activated protein kinases (MAPKs) c-Jun N-terminal protein kinase (JNK), p38, and extracellular signal-related kinase 1/2 (ERK1/2). The effect of the WTC dust on the MAPKs will be observed because these three proteins are involved in cell growth and apoptosis. ERK1/2 is also involved in survival and cell cycle progression. ERK1/2 is also known to have a part in cancer cell proliferation. JNK and p38 are involved also involved in inflammation. If these proteins are being expressed it could mean that survivors or first responders could be experiencing, or have experienced, one or more of these effects. Further studies should be performed to determine what immunological responses the MRC-5 human lung fibroblasts are having after being exposed to the WTC dust