scholarly journals Kynurenine Pathway in Skin Cells: Implications for UV-Induced Skin Damage

2012 ◽  
Vol 5 ◽  
pp. IJTR.S9835 ◽  
Author(s):  
Diba Sheipouri ◽  
Nady Braidy ◽  
Gilles J. Guillemin
Keyword(s):  
Amino Acid ◽  
Essential Amino Acid ◽  
Ultra Violet ◽  
Kynurenine Pathway ◽  
Uv Exposure ◽  
Skin Damage ◽  
Skin Cells ◽  
Amino Acid Tryptophan ◽  
Inflammatory Component

The kynurenine pathway (KP) is the principle route of catabolism of the essential amino acid tryptophan, leading to the production of several neuroactive and immunoregulatory metabolites. Alterations in the KP have been implicated in various neuropsychiatric and neurodegenerative diseases, immunological disorders, and many other diseased states. Although the role of the KP in the skin has been evaluated in small niche fields, limited studies are available regarding the effect of acute ultra violet exposure and the induction of the KP in human skin-derived fibroblasts and keratinocytes. Since UV exposure can illicit an inflammatory component in skin cells, it is highly likely that the KP may be induced in these cells in response to UV exposure. It is also possible that some KP metabolites may act as pro-inflammatory and anti-inflammatory mediators, since the KP is important in immunomodulation.

scholarly journals Indoleamine 2,3-dioxygenase expression is associated with chronic rhinosinusitis with nasal polyps and antrochoanal polyps

2011 ◽  
Vol 49 (3) ◽  
pp. 356-363
Author(s):  
T. Honkanen ◽  
A. Luukkainen ◽  
M. Lehtonen ◽  
T. Paavonen ◽  
J. Karjalainen ◽  
...  
Keyword(s):  
Amino Acid ◽  
Chronic Rhinosinusitis ◽  
Essential Amino Acid ◽  
Nasal Polyps ◽  
Allergic Airway Inflammation ◽  
Upper Airways ◽  
Indoleamine 2,3 Dioxygenase ◽  
Amino Acid Tryptophan ◽  
Sinus Mucosa

Chronic rhinosinusitis without and with nasal polyps (CRSwNP and CRSsNP), and antrochoanal polyps are different phenotypes with different pathomechanisms. Indoleamine 2,3-dioxygenase (IDO) is an enzyme expressed in many cells involved in the catabolism of the essential amino acid tryptophan to kynurenine. IDO might have a role in allergic airway inflammation. The aim was to evaluate if IDO expression is associated with CRSsNP, CRSwNP, or ACP. One hundred fifty specimens from the nasal cavity and sinus mucosa were immunohistochemically stained with mAb anti-IDO. The expression of epithelial and leukocyte IDO was associated with CRSwNP and ACP. The presence of ASA intolerance, asthma, atopy, smoking and use of medication did not significantly change the results. The different expression of IDO could putatively indicate the differences in the pathomechanisms of CRSsNP, CRSwNP and ACP. Further studies on the role of IDO in upper airways pathologies are required.

Dietary intake of tryptophan tied emotion-related impulsivity in humans

2019 ◽  
pp. 1-8 ◽  
Author(s):  
Florian Javelle ◽  
Descartes Li ◽  
Philipp Zimmer ◽  
Sheri L. Johnson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Food Intake ◽  
Essential Amino Acid ◽  
Food Habits ◽  
Psychological Disorder ◽  
Serotonin Synthesis ◽  
Amino Acid Tryptophan ◽  
Pass Through ◽  
Three Factor

Abstract. Emotion-related impulsivity, defined as the tendency to say or do things that one later regret during periods of heightened emotion, has been tied to a broad range of psychopathologies. Previous work has suggested that emotion-related impulsivity is tied to an impaired function of the serotonergic system. Central serotonin synthesis relies on the intake of the essential amino acid, tryptophan and its ability to pass through the blood brain barrier. Objective: The aim of this study was to determine the association between emotion-related impulsivity and tryptophan intake. Methods: Undergraduate participants (N = 25, 16 women, 9 men) completed a self-rated measure of impulsivity (Three Factor Impulsivity Index, TFI) and daily logs of their food intake and exercise. These data were coded using the software NutriNote to evaluate intakes of tryptophan, large neutral amino acids, vitamins B6/B12, and exercise. Results: Correlational analyses indicated that higher tryptophan intake was associated with significantly lower scores on two out of three subscales of the TFI, Pervasive Influence of Feelings scores r =  –.502, p < . 010, and (lack-of) Follow-Through scores, r =  –.407, p < . 050. Conclusion: Findings provide further evidence that emotion-related impulsivity is correlated to serotonergic indices, even when considering only food habits. It also suggests the need for more research on whether tryptophan supplements might be beneficial for impulsive persons suffering from a psychological disorder.

scholarly journals Two Deoxythymidine Triphosphate Synthesis-Related Genes Regulate Obligate Symbiont Density and Reproduction in the Whitefly Bemisia tabaci MED

2021 ◽  
Vol 11 ◽  
Author(s):  
Zezhong Yang ◽  
Cheng Gong ◽  
Yuan Hu ◽  
Jie Zhong ◽  
Jixing Xia ◽  
...  
Keyword(s):  
Amino Acid ◽  
Rna Interference ◽  
Bemisia Tabaci ◽  
Essential Amino Acid ◽  
Cellular Growth ◽  
Capacity Analysis ◽  
Host Insect ◽  
Obligate Symbiont ◽  
Pyrimidine Pathway

Deoxythymidine triphosphate (dTTP) is essential for DNA synthesis and cellular growth in all organisms. Here, genetic capacity analysis of the pyrimidine pathway in insects and their symbionts revealed that dTTP is a kind of metabolic input in several host insect/obligate symbiont symbiosis systems, including Bemisia tabaci MED/Candidatus Portiera aleyrodidarum (hereafter Portiera). As such, the roles of dTTP on both sides of the symbiosis system were investigated in B. tabaci MED/Portiera. Dietary RNA interference (RNAi) showed that suppressing dTTP production significantly reduced the density of Portiera, significantly repressed the expression levels of horizontally transferred essential amino acid (EAA) synthesis-related genes, and significantly decreased the reproduction of B. tabaci MED adults as well as the hatchability of their offspring. Our results revealed the regulatory role of dTTP in B. tabaci MED/Portiera and showed that dTTP synthesis-related genes could be potential targets for controlling B. tabaci as well as other sucking pests.

scholarly journals Role of Glutamine Synthetase in Nitrogen Metabolite Repression in Aspergillus nidulans

2001 ◽  
Vol 183 (20) ◽  
pp. 5826-5833 ◽  
Author(s):  
Soula Margelis ◽  
Cletus D'Souza ◽  
Anna J. Small ◽  
Michael J. Hynes ◽  
Thomas H. Adams ◽  
...  
Keyword(s):  
Amino Acid ◽  
Glutamine Synthetase ◽  
Heterologous Expression ◽  
Aspergillus Nidulans ◽  
Essential Amino Acid ◽  
Gene Encoding ◽  
Nitrogen Metabolite Repression ◽  
Link Type ◽  
Wide Range

ABSTRACT Glutamine synthetase (GS), EC 6.3.1.2 , is a central enzyme in the assimilation of nitrogen and the biosynthesis of glutamine. We have isolated the Aspergillus nidulans glnA gene encoding GS and have shown that glnA encodes a highly expressed but not highly regulated mRNA. Inactivation of glnA results in an absolute glutamine requirement, indicating that GS is responsible for the synthesis of this essential amino acid. Even when supplemented with high levels of glutamine, strains lacking a functionalglnA gene have an inhibited morphology, and a wide range of compounds have been shown to interfere with repair of the glutamine auxotrophy. Heterologous expression of the prokaryotic Anabaena glnA gene from the A. nidulans alcA promoter allowed full complementation of the A. nidulans glnAΔ mutation. However, the A. nidulans fluG gene, which encodes a protein with similarity to prokaryotic GS, did not replace A. nidulans glnA function when similarly expressed. Our studies with theglnAΔ mutant confirm that glutamine, and not GS, is the key effector of nitrogen metabolite repression. Additionally, ammonium and its immediate product glutamate may also act directly to signal nitrogen sufficiency.

scholarly journals L-tryptophan and depressive illness: a valuable adjunct to therapy?

1993 ◽  
Vol 17 (4) ◽  
pp. 223-224 ◽  
Author(s):  
Donald Eccleston
Keyword(s):  
Cerebrospinal Fluid ◽  
Amino Acid ◽  
Therapeutic Efficacy ◽  
Essential Amino Acid ◽  
Kynurenine Pathway ◽  
Depressive Illness ◽  
Western Diet ◽  
Human Nutrition ◽  
Valuable Adjunct ◽  
Original Observation

L-tryptophan is an essential amino acid in human nutrition. The minimum daily requirement for adults is in the range of 175 to 250 mg daily and this is normally exceeded in the average western diet which contains 600 to 1000 mg. Excess tryptophan is normally metabolised through the kynurenine pathway and only 1–2% of tryptophan in the diet is converted to 5-HT. The concept that 5-HT had a part to play in depressive illness evolved after the original observation by Ashcroft & Sharman in 1960 that patients with severe depressive illness had lower levels of the metabolite of 5-HT in cerebrospinal fluid compared with controls. In addition, early papers on the therapeutic efficacy of tryptophan suggested that it was potentially as successful as ECT.

ROLE OF KYNURENINE PATHWAY METABOLITES IN DEPRESSION-A REVIEW

2020 ◽  
pp. 1-6
Author(s):  
Priyadarshini Soni ◽  
Lubhan Singh ◽  
Prabhat Singh ◽  
Sokindra Kumar
Keyword(s):  
Amino Acid ◽  
Kynurenic Acid ◽  
Kynurenine Pathway ◽  
World Health ◽  
The World ◽  
Important Pathway ◽  
Hydroxyanthranilic Acid ◽  
Health Organization

Today most common psychiatric problem across the world is depression and stress is main source of ailment. According to World health organization, it will be the main cause of morbidity by 2020 in the world. Depression can critically affects the quality of life  as it is characterized by many symptoms like unhappy feeling, lack of interest and pleasure, down energy, inadequacy, regret feeling, slow-down of thoughts or reduction in physical movement, speech can affects, altered appetite or sleep, sad,  and increase the risk of suicide. Human body is inadequate to produce tryptophan which is a crucial amino acid; therefore it must be required from diet. After absorption, L-tryptophan crosses the BBB (Blood brain barrier) by non-specific L-type amino acid transporter and act as precursor to various metabolic pathways in central nervous system (CNS). Kynurenine is an important pathway that is associated with tryptophan (TRP) metabolism, where it develops a lot of metabolites such as 3-hydroxykynurenine (3HK), anthranilic acid (AA), kynurenic acid (KYNA), 3-hydroxyanthranilic acid (3HAA) and quinolinic acid (QUIN) known as kynurenines. It is already reported previously that disturbance in neuroprotective and neurotoxic metabolites leads to many psychiatric disorders. This review summarizes the role of kynurenine pathway metabolites in depression.   

scholarly journals Tryptophan metabolism, disposition and utilization in pregnancy

2015 ◽  
Vol 35 (5) ◽  
Author(s):  
Abdulla A.-B. Badawy
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Fetal Growth ◽  
Growth And Development ◽  
Essential Amino Acid ◽  
Tryptophan Metabolism ◽  
Amino Acid Tryptophan ◽  
In Pregnancy

The essential amino acid tryptophan (Trp) is especially important in pregnancy for protein synthesis by mother and fetus, fetal growth and development and prevention of fetal rejection by immunosuppression. A Trp utilization concept based on these physiological requirements in pregnancy is proposed.

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