EN1 Website Post 1 Sofia Levy

Our group decided to research the possibility of studying Deinococcus radiodurans and their self-reparation processes in order to treat autoimmune diseases such as Multiple Sclerosis and Rheumatoid Arthritis. According to a study done in Denmark, about 9.4% of the population suffers from at least one autoimmune disease (Cooper, 2009). These autoimmune diseases occur when the immune system attacks the body itself, destroying critical tissues and organs (Bakker, 2014). While many naturalistic medicines, anti-inflammatory medications, steroids, and immunosuppressive medications may help treat and lessen the detrimental effects of autoimmune diseases, their ceases to be a way to completely cure or prevent the diseases from occurring (Bakker, 2014). Other medical procedures such as surgery or radiation treatment similarly cannot prevent or cure autoimmune diseases (Bakker, 2014). Therefore, by studying how the D. radiodurans bacterium can repair its genome after being broken into pieces by extreme amounts of radiation, there may be a way for cells affected by autoimmune diseases to fix their own DNA. Whether by replicating enzymes that catalyze the D. radiodurans’ DNA reparation and synthesis or by promoting genes that express self-reparation qualities, using the D. radiodurans as a model could help thousands of people around the world to help cure their autoimmune diseases.

While the D. radiodurans bacteria have recently become a popular topic of research, information on exactly how they self repair their genome and how to apply that information for medical benefits is still relatively unclear. What is known is that the D. radiodurans is able to withstand extreme levels of radiation, amounting up to 7 kGy (Slade, 2009). This high level of radiation breaks the genome of the bacterium about 100-150 times (Slade, 2009). In normal circumstances, most cells would not be able to recover after its DNA is shattered. But the D. radiodurans is special in that it undergoes a complex process whereby they can self-repair their genome within hours of being destroyed. About an hour and a half after the genome of the bacterium is destroyed by radiation, no DNA reparation or DNA synthesis occurs (qtd. in Slade, 2009). But within the the hour after this stagnant period, “ DNA polymerase I (Pol I)-dependent DNA synthesis and RecA-dependent recombination processes” enables the self-reparation process (Slade, 2009). It begins with extended synthesis-dependent strand annealing (ESDSA) in which strands of newly synthesized DNA are created from the original fragmented complementary strands (qtd. in Slade, 2009). These newly created strands then arrange themselves into “long linear intermediates” (Slade, 2009). Lastly, the RecA-dependent recombination process helps these fragmented pieces of DNA that were created before and after radiation enclose into circular chromosomes (Slade, 2009). By understanding the process by which the Deinococcus radiodurans utilizes DNA polymerase I (Pol I)-dependent DNA synthesis and RecA-dependent recombination processes to fix its destroyed genome, it may be possible for cells destroyed by autoimmune diseases to self-repair themselves even after being damaged by the immune system.

Bakker, E. (2014, August 26). AutoImmune Disease Causes. Retrieved September 28, 2018, from

https://ericbakker.com/autoimmune-diseases-causes/

Cooper, G. S., Bynum, M., & Somers, E. C. (2009, October 09). Recent insights in the epidemiology of autoimmune diseases: Improved prevalence estimates and understanding of clustering of diseases. Retrieved September 28, 2018, from https://www.sciencedirect.com/science/article/pii/S089684110900122X

Slade, D., Lindner, A. B., Paul, G., & Radman, M. (2009, March 19). Recombination and Replication in DNA Repair of Heavily Irradiated Deinococcus radiodurans. Retrieved September 28, 2018, from https://www.sciencedirect.com/science/article/pii/S009286740900066X

 

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