Team:NTU-Taida/Project/Introduction

From 2012.igem.org

Revision as of 19:00, 25 October 2012 by Lbwang (Talk | contribs)

Introduction

Introduction

Contents

Complex Adaptive BioSystems

Peptide-Based Therapies

Structure of PEPDEX

Bacteria and Immune System

Bacteria and Nervous System

The novel conceptual model “Brain-Gut Axis” has received emerging attention recently. Lots of studies showing evidence that intestinal microbiota have profound impacts on our nervous systems blossom during this 5~10 years. They interact with each other bidirectionally via various pathways. These include neuroendocrine (hypothalamus-pituitary-adrenal axis), immune systems (neuromodulating cytokines), enteric nervous systems and autonomic nervous systems (vagus nerve). Gut microbes produce substance such as tryptophan-related metabolites kynurenic acid, short chain fatty acids, and neurometabolites GABA, noradrenalin, and dopamine that potentially target to and influence functions of our central nervous systems. In the process of neurodevelopment, they modulate the expression level of many critical genes, such as brain-derived neurotropic factor (BDNF), NMDA receptors or 5-HT receptors and communicate with brain regions like striatum, hippocampus, amygdale, hypothalamus, and cingulated gyrus. It has long been known that the colonization of gut flora is related to the stress response of the hosts, changing their states of anxiety and exploratory behavior. Diseases such as inflammatory bowel diseases (IBS) and multiple sclerosis (MS) are also documented to be associated with intestinal microorganisms. New focus has been greatly put on many neuropsychiatric diseases, for instance, autism spectrum disorders (ASD), depression, anxiety disorders, and schizophrenia.

Reference

  1. Collins SM, et al. (2012) The interplay between the intestinal microbiota and the brain. Nature Reviews Microbiology. AOP, published online 24 September 2012, 1-8.
  2. Cryan JF, et al. (2012) Mind-altering microorganisms: the impact of the gut microbiota on brain and behaviour. NatureReviews Neuroscience 13: 701-712.
  3. Rhee SH, et al. (2009) Principles and clinical implications of the brain–gut–enteric microbiota axis. Nature Rev. Gastroenterol. Hepatol. 6, 306–314.
  4. Neufeld KM, et al. (2010) Reduced anxiety-like behavior and central neurochemical change in germ-free mice. Neurogastroenterol. Motil. 23, 255–264.
  5. Bercik, P. et al. (2011) The intestinal microbiota affect central levels of brain-derived neurotropic factor and behavior in mice. Gastroenterology 141, 599–609.
  6. Lyte M, et al. (2006) Induction of anxiety-like behavior in mice during the initial stages of infection with the agent of murine colonic hyperplasia Citrobacter rodentium. Physiol. Behav. 89, 350–357.
  7. Bravo, J. A. et al. (2011) Ingestion of Lactobacillus strain regulates emotional behavior and central GABA receptor expression in a mouse via the vagus nerve. Proc. Natl Acad. Sci. USA 108, 16050–16055.
  8. Wall, R. et al. (2012)Contrasting effects of Bifidobacterium breve NCIMB 702258 and Bifidobacterium breve DPC 6330 on the composition of murine brain fatty acids and gut microbiota. Am. J. Clin. Nutr. 95, 1278–1287.
  9. Tillisch, K. et al. (2012) Modulation of the brain–gut axis after 4 week intervention with a probiotic fermented dairy product. Gastroenterology 142, S-115.
  10. Mayer EA. (2011) Gut feelings: the emerging biology of gut–brain communication. Nature Rev. Neurosci. 12, 453–466.
  11. Freestone PP, et al. (2008) Microbial endocrinology: how stress influences susceptibility to infection. Trends Microbiol. 16, 55–64.
  12. Kaper JB, et al. (2005). Bacterial cell to cell signaling in the gastrointestinal tract. Infect. Immun. 73, 3197–3209.
  13. Neufeld KM, et al. (2011). Reduced anxiety-like behavior and central neurochemical change in germ-free mice. Neurogastroenterol. Motil. 23, 255–264.
  14. Heijtz RD, et al. (2011) Normal gut microbiota modulates brain development and behavior. Proc. Natl Acad. Sci. USA 108, 3047–3052.
  15. Gareau MG, et al. (2011) Bacterial infection causes stress-induced memory dysfunction in mice. Gut 60, 307–317.
  16. Desbonnet L, et al. (2010) Effects of the probiotic Bifidobacterium infantis in the maternal separation model of depression. Neuroscience 170, 1179–1188.
  17. Lyte M. (2011) Probiotics function mechanistically as delivery vehicles for neuroactive compounds: microbial endocrinology in the design and use of probiotics. Bioessays 33, 574–581.
  18. Derecki, N. C. et al. (2010) Regulation of learning and memory by meningeal immunity: a key role for IL 4. J. Exp. Med. 207, 1067–1080.
  19. Lyte M, et al. (2011) Stress at the intestinal surface: catecholamines and mucosa– bacteria interactions. Cell Tissue Res. 2431, 23–32..
  20. Lee Y K, et al. (2011) Proinflammatory T cell responses to gut microbiota promote experimental autoimmune encephalomyelitis. Proc. Natl Acad. Sci. USA 108, 4615–4622.
  21. Berer, K. et al. (2011) Commensal microbiota and myelin autoantigen cooperate to trigger autoimmune demyelination. Nature 479, 538–541.
  22. Juárez I, et al. (2008) Ontogeny of altered dendritic morphology in the rat prefrontal cortex, hippocampus, and nucleus accumbens following cesarean delivery and birth anoxia. J. Comp. Neurol. 507, 1734–1747.