Project

Background

The Role of P. Acnes in Acne Vulgaris

     The bacteria Propionibacterium acnes is responsible for the condition called Acne Vulgaris, more commonly known as acne. Although P. Acnes is not an issue for most people, there are certain virulent strains that exacerbate acne inflammation. The bacteria thrives in the presence of lipids, specifically sebum, which serves as the primary source of the bacteria's energy and sustenance. An increase of sebum production attracts bacteria into hair follicles, where the bacteria can multiply and colonize, resulting in an inflammatory reaction of cysts and pustules, which can lead to acne scars.

P. acnes

Description

For the 2014 Competition season, Montgomery_Cougars_NJUSA aims to create a better solution for acne reduction. Acne is a problem that affects nearly 80% of American adolescents. Unfortunately, this widespread problem does not have a concrete solution. Proactiv, a leading acne medication company, uses benzyl peroxide and/or salicylic acid and bacteria alike to shed the skin and this unclog pores from the patient’s face. This method is moderately painful and is not always 100% effective. So, to combat this widespread ailment, Montgomery iGEM has decided to take a different approach.

In an effort to create a less invasive treatment we decided to produce an enzyme to break down the sebum on human skin, thereby reducing the bacteria's source of energy and ability to colonize. Because sebum is made of triglyceride oils, wax esters, squalene, and metabolites of fat-producing cells, we sought a group of enzymes that would break down these components. Through our research, we have concluded that there is a positive correlation between patients with acne and presence of triglycerides and wax esters. Our mechanism ultimately focused on targeting these substances. In reducing these substances, we effectively deplete the food that the P. acne bacteria needs to thrive and elicit the inflammatory response we perceive to be acne.

Design

Promotor: BBa_R0010
RBS: BBa_B0034
Protein Coding Domain: BBa_K398005 or BBa_K398006
Signal Protein: BBa_E0040
Terminator: BBa_B0015

Our design for our biological part includes the standard promotor, RBS and Terminator. The functioning part of the gene includes either Medium Chain Alcohol or Aldehyde Dehydrogenase. The GFP protein is also included to act as a signal showing that the recombination was successful.

Enzyme/Gene Selection

When we first started our product research, we had many considerations to address. At first, we planned on creating an antibiotic that would directly combat the bacteria. Once we realized that making a bacteria, namely E. Coli, synthesize a protein to break down other bacteria was much beyond our scope, we decided to focus on what exactly makes the bacteria thrive. Thus, we moved onto examining the sebum within the skin that allows bacteria to grow and indirectly create the inflammatory response known as acne. As mentioned before, sebum is composed of wax esters, triglycerides, squalene among other lipids and fats native to the skin of humans. We figured that if we limited the food supply for the bacteria, the persistence of acne would decrease.

Finding a way to break down the components of squalene was a challenge all in itself. Our research showed that sebum is primarily broken down through beta oxidation. One of the most crucial steps of beta oxidation is the removal of hydrogen by means of dehydrogenases. The process of finding a dehydrogenase that would work in our mechanism was extremely frustrating. The most prevalent component of the sebum is a substance called sapienic acid. This acid is key in providing food for the P. acne bacteria simply because there are very little natural substances that can break this down. The carboxylic functional group is rarely targeted in typical cellular functions. We had tried to target this but found no suitable match. Our breakthrough came in late May, when we found that another component of sebum, wax esters, could be broken down by the method we had previously proposed. Wax esters contain alcohol functional groups that our mechanism targets. Thus, theoretically at least, we have created an alternate way to reduce acne production in humans.