Abstract
Over the last thirty years, research on tryptophan has progressively moved from an almost “obscure” to a primary field of research. Over the last decade, interest in tryptophan and thus number of publications on the subject has been significantly growing. Looking at Pubmed today (March 2010), the overall number of publications about tryptophan, indoleamine 2,3 dioxygenase (IDO), and the kynurenine pathway has been rising significantly (Fig. 1). Tryptophan research got its first “boost” in the eighties with the identification of neuroactive compounds such as quinolinic acid and kynurenic acid and their actions as agonist and antagonist of the N-methyl-D-aspartate receptor. Then, the field was subject to another major discovery when IDO-1 was identified as a key regulator of the immune response. Publications on IDO have the highest growth rate as shown on Figure 1. More Recently, a study has demonstrated that kynurenic acid is implicated in the regulation of the leukocytes binding on the endothelium (Barth et al 2009, The Journal of biological Chemistry) and a second one showed that kynurenine is a potent vasodilator (Wang et al 2010, Nature Medicine) highlighting the essential roles played by some of the tryptophan metabolites in both physiological and pathological conditions. This is likely to be only the tip of the iceberg.
Evolution of the publications in the field of tryptophan research over the last 10 year.
For the past 35 years the Executive Committee of the International Society for Tryptophan Research (ISTRY) has been organizing triennial meetings in order to cover most of the incumbent key scientific information on chemical and biological aspects of Tryptophan research. The first of those meetings was held in Padua in 1974. Since then a significant number of scientists with completely different backgrounds (chemists, anatomists, molecular biologists, immunologists, embryologists, neuroscientists, psychiatrists, oncologists, etc.) have been presenting and discussing their data on the roles of tryptophan and its main metabolites in animal and human nutrition, behaviour and other aspects of physiology and pathology.
Past meetings have been alternatively organized in Japan, USA and Europe. Prof. Flavio Moroni chaired the 2009 edition of the meeting in Florence, Italy. It was a really successful meeting with high quality speakers and presentations.
During this 12th ISTRY Meeting most of the aspects of tryptophan research have been broached including the neuroscience, metabolism, psychology, inflammation, nutrition, molecular, cellular, enzyme, immune regulation, medicinal chemistry, and analytical chemistry domains. Several of the key speakers have kindly agreed to write a short manuscript related to their presentations in a special issue of the International journal for Tryptophan Research (IJTR). These include reviews and original scientific reports describing the involvement of the tryptophan catabolites in several diseases, new mechanisms involved in immune regulation and new enzyme variants.
The next ISTRY meeting will take place in Sydney, Australia in 2012 and will be hosted by Dr. Gilles Guillemin. We hope that many more scientists working on tryptophan research will join ISTRY over the next 3 years and attend this 13th ISTRY meeting.