Team:Montgomery Cougars NJUSA/Project
From 2014hs.igem.org
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.
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 salicylic acid to burn off skin and bacteria alike 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 of triglyceride oils, wax, squalene, and metabolites of fat-producing cells, we sought a group of enzymes that would break down these components. To counter each of these components, we have tracked down enzymes such as wax-ester hydrolase, triglyceride lipase, squalene monooxygenase, HMG CoA Reductase and Lipoprotein Lipase. Throughout the next few weeks, we plan to find genes that we can transform bacteria with to include these enzymes. Our final product will include genes that code for many of these enzymes, increasing our chance of reducing nutrients for acne-inducing bacteria.
Design
Enzyme/Gene Selection
Initially, we thought to create a cocktail of enzymes that would break down components of sebum (triglyceride oils, wax, squalene, and metabolites of fat-producing cells). However, as a new team, we decided that choosing one enzyme would be the most practical.
Enzyme | Gene |
---|---|
Triglyceride Lipase-lipases that hydrolyse ester linkages of triglycerides | PNPLA2 gene provides instructions for making an enzyme called adipose triglyceride lipase |
Triacylglycerol Lipase: the fat-splitting enzyme in pancreatic juice; it hydrolyzes triacylglycerol to produce a diacylglycerol and a fatty acid anion
triacylglycerol + H2O diacylglycerol + a carboxylate | LIPC gene encodes hepatic triglyceride lipase |
Squalene epoxidase is an enzyme released by the dermatophyte fungi to break down Squalene. | SQLE gene: encodes squalene epoxidase |
HMG CoA Reductase: an enzyme that catalyzes the production of mevalonate from HMG CoA. It is a rate controlling enzyme in the mevalonate pathway that regulates the synthesis of cholesterol and other isoprenoids. | HMGCR |
Lipoprotein Lipase - water soluble enzyme that hydrolyzes triglycerides into two fatty acids. | LPL gene |
Initially, we chose to use lipase as the enzyme to eliminate the bacterial food source. Because sebum is composed of 57.5% triglycerides and fatty acids, we decided that lipase which breaks down triglycerides into free fatty acids would be the optimal protein. However, through further research, we learned that when lipase converts triglycerides to free fatty acids, this in fact exacerbates the inflammatory response. Free fatty acids increase clumping of bacteria, which in turn allows colonization in the duct of more them. When inflammatory mediators penetrate the skin an inflammatory reaction is initiated. P. acnes lipase (GehA, glycerol-ester hydrolase A) is in fact a virulence factor involved in the pathogenesis of acne. In Shuichi Higaki’s research paper, Higaki asserts that a lipase inhibitor can help treat acne. We contemplated the idea of trying to find a lipase inhibitor; however, few inhibitors are proteins. In another approach, we thought we could break down the fatty acids before they are absorbed into a cell.
Our Project
- Project Overview
- Pathogenesis of Acne
- Selecting the Gene
- Registry Parts
- Mathematical Model
- Error Analysis