Team:GA State SW Jiaotong/Description
Background
Losing 50-100 strands of hair everyday is a normal phenomenon[1]. However, when a person sheds significantly more hair, this is considered as hair loss or alopecia. Unfortunately, alopecia is a common symptom that affects many adults. In Asia, up to 73% of the population reported to experience hair loss [2]. In western countries, over 40% of the population are also affected by hair loss[2]. Hair loss can be a result of many factors including genetics, hormone changes, medications, and stress[3].
Fig1.Hair loss is a global problem
Most of the research studies that exist focuses on alopecia areata (also known as “patchy hair loss”) and androgenetic alopecia (also known as “male/female pattern baldness”), which is a result of an autoimmune disease and androgen hormones, respectively. However, there is a limited amount of studies that addresses stress alopecia or telogen effluvium, which is hair loss caused by a stressful event. According to a study by Misery, 1/5 of the population in the United States suffers from hair loss that is caused by stress[4].
Problem
Hair loss can impact one’s self confidence and can lead to psychological issues such as depression and anxiety. According to a study, over 60% of the men that participated in the study said that hair loss was a big feature in one’s image and agreed that it can lower self esteem[6]. In women, hair is an essential feature to one’s identity and has a stronger effect in women’s self esteem. This was seen in women chemotherapy patients who experienced hair loss and developed a poorer image of themselves[7].
Fig2. Hair transplant and existing drugs
Unfortunately, there are no current drugs or treatments that can effectively target stress alopecia. The existing drugs on the market that do promote hair growth, such as Finasteride and Minoxidil, are expensive and have inevitable side effects[5].
In order to alleviate the issues of stress hair loss, Georgia State University/ Southwest Jiaotong University iGEM team aims to use synthetic biology to create a hair product that can be used to assist in hair growth.
Our Project Solution
The purpose of our project is to engineer a hair care product that can be applied in the bald spots of the scalp to help stimulate hair growth. One research revealed the relationship between the stress hormone, corticosterone, and hair follicle stem cell (HFSC) activity[8]. It turns out that when the body undergoes stress, this increases the level of the stress hormone, corticosterone, which keeps the hair follicle in its resting phase and prevents the regeneration of hair[8]. In order for hair to grow back, it is ideal for the HFSC to go through more cycles of regeneration.
Through research, it was found that the Gas6 protein promotes the growth of hair follicles[8]. In addition, epidermal growth factors (EGF) are platelet concentrates that can stimulate the growth of hair follicle cells[9]. These two ingredients are the key players used in our final product.
Fig3. The mechanism of Gas6 and EGF
The general plan of our experimental design is as follows: First, our team will construct a plasmid that can heterologously express GAS6 and EGF by the bacteria Bacillus subtilis. Next, in order to address the safety issues and prevent the growth of the bacteria outside of the scalp, we will introduce the toxin-antitoxin system, a dual regulation system, to the bacteria so that the bacteria commits suicide when it is outside of the scalp environment. Then, the appropriate amount of GAS6 and EGF will be determined. Finally we will combine the successfully expressed B. subtilis with a hydrogel to create a hair care product that can address stress alopecia.
COVID-19
The COVID-19 pandemic had a slight hindrance to our workflow. Since our team is a joint team from Georgia State University in Atlanta, USA, and Southwest Jiaotong in Chengdu, China, a 12-hour time difference was a barrier we struggled to overcome when initially working on the project. There was difficulty arranging the times to hold meetings, and we could only start working on the wet lab for the project from August onwards. However, this also allowed us to strengthen our communication skills and overcome the cultural and language barriers that could have overwhelmed us. We were able to learn from each other and work towards being a single team, and that learning journey was by itself an incredible experience and a huge learning curve.
Sources
1. Cheng AS, Bayliss SJ, The genetics of hair shaft disorders. J Am Acad Dermatol 2008;59(1):1-22.
2. Lee, Won-Soo, and Hae-Jin Lee. Characteristics of androgenetic alopecia in asian. Annals of dermatology vol. 24,3 (2012): 243-52. doi:10.5021/ad.2012.24.3.243
3.Mayo Clinic (n.d.). Hair Loss. https://www.mayoclinic.org/diseases-conditions/hair-loss/symptoms-causes/syc-20372926
4.Hair Loss: An epidemic approach. Journal of the American Academy of Dermatology (2008). doi: 10.1016/j.jaad.2004.10.423
5.Price, Vera H. Treatment of Hair Loss. New England Journal of Medicine vol. 341,13 (1999): 964-73 10.1056/NEJM199909233411307
6.Alfonso M, Richter-Appelt H, Tosti A, Viera MS, García M. The psychosocial impact of hair loss among men: a multinational European study. Curr Med Res Opin. 2005 Nov;21(11):1829-36. doi: 10.1185/030079905X61820. PMID: 16307704.
7.Carpenter, JS., Brockopp, DY. Evaluation of self-esteem of women with cancer receiving chemotherapy. Oncol Nurs Forum. 1994 May;21(4):751-7. PMID: 8047474.
8.Choi, S., Zhang, B., Ma, S. et al. Corticosterone inhibits GAS6 to govern hair follicle stem-cell quiescence. Nature 592, 428–432 (2021). https://doi.org/10.1038/s41586-021-03417-2
9.Tan, P., Xie, Y., Wu, W., Zhang, P., Gao, Y., Liu, K., Zhou, S. and Li, Q. (2019) Concentrated Growth Factor from Autologous Platelet Promotes Hair Growth in Androgenetic Alopecia. Journal of Biomedical Science and Engineering, 12, 201-211. doi: 10.4236/jbise.2019.123014.
