Project Description

We must admit that a nice mental state plays an essential role in maintaining our overall health. With the rapid changing in nowadays society, we can easily noticed that the number of people having problems about their mental health, like depression,anxiety and insomnia, is in an increasing trend.¹ And according to several researches, mental health problems closely related to many physical disease, like high blood pressure and metabolic disease.^2,3 What’s worse, this trend is developing tremendously during the pandemic prevailing of COVID-19.

COVID-19, occurred at the end of 2019, not only made profound influence on the economy of society, structure of industry and people’s lifestyle, but also posed a great threat to human health. Apart from directly causing damage to human body,like pneumonia and multiple organs injury, coronavirus also poses great pressure to individual’s mental health, which is hard to neglect.⁴ According to the surveys carried out in US, China and Europe, during the pandemic time, the ratio of people suffering from depression, anxiety and insomnia of different degrees is a climbing trend.^5,6

As a result, in this year’s iGEM competition, XJTU-China decides to use the technology of synthetic biology to bring changes to people who suffer from mental health problems like depression, anxiety and insomnia, in order to improve their life quality. Due to the regulation of quarantine and reduction in going out, dealing with those mental health problems by making differences to people’s diets can be more convenient and ensure their safety. Tryptophan, as an essential amino acids for human, also shows excellent potential in reducing depression and anxiety and promoting sleep quality.^7,8,9,10 After having sufficient investigation and profound discussion with experts in nutriology, we decide to create a healthy type of milk based on tryptophan

We aimed at developing a domestic tryptophan milk producer using knowledge and technology of synthetic biology. Synthetic biology enables us to make functional change to given mode bacteria and fulfill our goal. Equipped with those skills and knowledge, we choose E.coliDH5α to accept our designed plasmid, which gives it the ability to produce Tryptophan efficiently and controllable. The core design of our produce circuit is the use of Toogle Switch, which is divided into two branches: growing pass and producing pass. And E.coli, responding to the concentration of IPTG and the change of temperature, is able to manipulate the ratio of energy and substance input to these two branches, then automatically change between these two statuses. The growing pass is constructed with the key gene: pykA ,to maintain the regular growth of E.coli. And the producing circuit contains three main genes: aroG, trpA and trpB. In this part, aroG is essential for the distribution of energy and substance between growth and produce process. And considering the metabolic pressure for E.coli itself, we finally choose to link two main genes in the produce process of Tryptophan.¹¹

On top of that, we design the hardware to help us achieve the goal of domestic produce and use of Tryptophan. The design of our hardware can be divided into four key parts: temperature control module, Single Chip Microcomputer, detecting module and magnetic stirring module. We are trying to centralize all of these modules in a machine as small as possible, which gives our device the advantage of being portable and convenient.

IGEM competition is absolutely not the culmination of our exploration! During the precious journey in iGEM, we have endeavored to arouse public’s attention to their own mental health situation and aid people release their pain of depression, anxiety and insomnia. And after the competition, we will want to practice some innovative ideas we came up with at brain-storm stage, like how to polish and improve our hardware design to make it be widely accepted? How to use commercial strategies to advertise it. We really want our design to come down to earth with the purpose of releasing pain of people suffering from depression and bringing real convenience to public’s daily life , anxiety and insomnia during this special. Fortunately, we are on our way to achieve that goal.

References

1 Merikangas, K. R. et al. Lifetime Prevalence of Mental Disorders in U.S. Adolescents: Results from the National Comorbidity Survey Replication–Adolescent Supplement (NCS-A). Journal of the American Academy of Child & Adolescent Psychiatry 49 (2010).
2 Depner, C. M., Stothard, E. R. & Wright, K. P. Metabolic Consequences of Sleep and Circadian Disorders. Current Diabetes Reports 14 (2014).
3 ALFANO, C. A., GINSBURG, G. S. & KINGERY, J. N. Sleep-Related Problems Among Children and Adolescents With Anxiety Disorders. Journal of the American Academy of Child & Adolescent Psychiatry 46 (2007).
4 Robert, S. et al. Depression, Anxiety and Stress during COVID-19: Associations with Changes in Physical Activity, Sleep, Tobacco and Alcohol Use in Australian Adults. International journal of environmental research and public health 17 (2020).
5 D.S., K. W., A., C. S., C., T. E., A., L. D. & S., D. N. Loneliness during the first half-year of COVID-19 Lockdowns. Psychiatry Research 294 (2020)
6 Killgore, W. D. S., Cloonan, S. A., Taylor, E. C. & Dailey, N. S. Loneliness: A signature mental health concern in the era of COVID-19. Psychiatry Research 290 (2020).
7 Dalfsen, J. H. v. & Markus, C. R. The serotonin transporter gene-linked polymorphic region (5-HTTLPR) and the sleep-promoting effects of tryptophan: A randomized placebo-controlled crossover study. Journal of Psychopharmacology 33 (2019).
8 Hudson, Hudson, Hecht & MacKenzie. Protein source tryptophan versus pharmaceutical grade tryptophan as an efficacious treatment for chronic insomnia. Nutritional Neuroscience 8 (2005).
9 R, L. H., Sanjiv, A. & L, F. V. Tryptophan Intake in the US Adult Population Is Not Related to Liver or Kidney Function but Is Associated with Depression and Sleep Outcomes. The Journal of nutrition 146 (2016).
10 Schneider-Helmert, D. & Spinweber, C. L. Evaluation of l -tryptophan for treatment of insomnia: A review. Psychopharmacology 89 (1986).
11 HAO Dali et al. Site-mutation of AroG Gene and Co-expression with TrpBA Gene in Escherichia coli. Chinese Journal of Applied and Environmental Biology 19, 817-821 (2013).