{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,14]],"date-time":"2026-07-14T22:42:04Z","timestamp":1784068924095,"version":"3.55.0"},"reference-count":58,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2023,3,22]],"date-time":"2023-03-22T00:00:00Z","timestamp":1679443200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Wroc\u0142aw Medical University","award":["SUBZ.C230.23.076"],"award-info":[{"award-number":["SUBZ.C230.23.076"]}]},{"name":"Wroc\u0142aw Medical University","award":["NN402366733"],"award-info":[{"award-number":["NN402366733"]}]},{"name":"Wroc\u0142aw Medical University","award":["NN402586140"],"award-info":[{"award-number":["NN402586140"]}]},{"name":"Wroc\u0142aw Medical University","award":["2014\/15\/B\/NZ6\/02378"],"award-info":[{"award-number":["2014\/15\/B\/NZ6\/02378"]}]},{"name":"Polish Ministry of Higher Education","award":["SUBZ.C230.23.076"],"award-info":[{"award-number":["SUBZ.C230.23.076"]}]},{"name":"Polish Ministry of Higher Education","award":["NN402366733"],"award-info":[{"award-number":["NN402366733"]}]},{"name":"Polish Ministry of Higher Education","award":["NN402586140"],"award-info":[{"award-number":["NN402586140"]}]},{"name":"Polish Ministry of Higher Education","award":["2014\/15\/B\/NZ6\/02378"],"award-info":[{"award-number":["2014\/15\/B\/NZ6\/02378"]}]},{"name":"National Science Center, Poland","award":["SUBZ.C230.23.076"],"award-info":[{"award-number":["SUBZ.C230.23.076"]}]},{"name":"National Science Center, Poland","award":["NN402366733"],"award-info":[{"award-number":["NN402366733"]}]},{"name":"National Science Center, Poland","award":["NN402586140"],"award-info":[{"award-number":["NN402586140"]}]},{"name":"National Science Center, Poland","award":["2014\/15\/B\/NZ6\/02378"],"award-info":[{"award-number":["2014\/15\/B\/NZ6\/02378"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Cells"],"abstract":"<jats:p>Background: Seeing that there are no data about associations between serotonin gene polymorphism and tryptophan catabolite concentration during PEG-IFN-\u03b12a treatment, the aim of the current study is to examine (a) the associations between polymorphisms within the HTR1A, TPH2, and 5-HTT genes and the severity of depression symptoms and (b) the relationships among rs6295, rs4570625, and 5-HTTLPR rs25531polymorphisms and indoleamine 2,3-dioxygenase (IDO) activity, as well as kynurenine (KYN), tryptophan (TRP), kynurenic acid (KA), and anthranilic acid (AA) concentrations. Materials and methods: The study followed a prospective, longitudinal, single-center cohort design. The severity of the depressive symptoms of 101 adult patients with chronic HCV infections was measured during PEG-IFN-\u03b12a\/RBV treatment. We used the Montgomery\u2013\u00c5sberg Depression Rating Scale (MADRS) to assess the severity of depressive symptoms. The subjects were evaluated six times\u2014at baseline and at weeks 2, 4, 8, 12, and 24. At all the time points, MADRS score, as well as KYN, TRP, KA, and AA concentrations, and IDO activity were measured. At baseline, rs6295, rs4570625, and 5-HTTLPR rs25531polymorphisms were assessed. Results: Subjects with C\/C genotypes of 5-HT1A and lower-expressing alleles (S\/S, LG\/LG, and S\/LG) of 5-HTTLPR scored the highest total MADRS scores and recorded the highest increase in MADRS scores during treatment. We found associations between TRP concentrations and the TPH-2 and 5-HTTLPR rs25531 genotypes. Conclusions: Our findings provide new data that we believe can help better understand infection-induced depression as a distinct type of depression.<\/jats:p>","DOI":"10.3390\/cells12060970","type":"journal-article","created":{"date-parts":[[2023,3,23]],"date-time":"2023-03-23T04:37:28Z","timestamp":1679546248000},"page":"970","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["HTR1A, TPH2, and 5-HTTLPR Polymorphisms and Their Impact on the Severity of Depressive Symptoms and on the Concentration of Tryptophan Catabolites during Hepatitis C Treatment with Pegylated Interferon-\u03b12a and Oral Ribavirin (PEG-IFN-\u03b12a\/RBV)"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3997-609X","authenticated-orcid":false,"given":"Tomasz","family":"Pawlowski","sequence":"first","affiliation":[{"name":"Department of Psychiatry, Wroc\u0142aw Medical University, 50-367 Wroc\u0142aw, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6295-2742","authenticated-orcid":false,"given":"Krzysztof","family":"Malyszczak","sequence":"additional","affiliation":[{"name":"Department of Psychiatry, Wroc\u0142aw Medical University, 50-367 Wroc\u0142aw, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3751-0608","authenticated-orcid":false,"given":"Dariusz","family":"Pawlak","sequence":"additional","affiliation":[{"name":"Department of Pharmacodynamics, Medical University of Bialystok, 15-089 Bia\u0142ystok, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ma\u0142gorzata","family":"Inglot","sequence":"additional","affiliation":[{"name":"Department of Infectious Diseases, Liver Diseases and Acquired Immune Deficiency, Wroclaw Medical University, 50-367 Wroc\u0142aw, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ma\u0142gorzata","family":"Zalewska","sequence":"additional","affiliation":[{"name":"Department of Infectious Diseases, Liver Diseases and Acquired Immune Deficiency, Wroclaw Medical University, 50-367 Wroc\u0142aw, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2633-520X","authenticated-orcid":false,"given":"Anna","family":"Grzywacz","sequence":"additional","affiliation":[{"name":"Independent Laboratory of Health Promotion, Pomeranian Medical University in Szczecin, 70-111 Szczecin, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marek","family":"Radkowski","sequence":"additional","affiliation":[{"name":"Department of Immunopathology of Infectious and Parasitic Diseases, Medical University of Warsaw, 02-091 Warsaw, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tomasz","family":"Laskus","sequence":"additional","affiliation":[{"name":"Department of Adult Infectious Diseases, Medical University of Warsaw, 02-091 Warsaw, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6072-4559","authenticated-orcid":false,"given":"Justyna","family":"Janocha-Litwin","sequence":"additional","affiliation":[{"name":"Department of Infectious Diseases and Hepatology, Wroclaw Medical University, 50-367 Wroclaw, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8582-9958","authenticated-orcid":false,"given":"Dorota","family":"Frydecka","sequence":"additional","affiliation":[{"name":"Department of Psychiatry, Wroc\u0142aw Medical University, 50-367 Wroc\u0142aw, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,3,22]]},"reference":[{"key":"ref_1","first-page":"1517","article-title":"Depression is the leading cause of disability around the world","volume":"317","author":"Friedrich","year":"2017","journal-title":"JAMA"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"96","DOI":"10.1016\/j.jad.2014.10.010","article-title":"Depression is not a consistent syndrome: An investigation of unique symptom patterns in the STAR*D study","volume":"172","author":"Fried","year":"2015","journal-title":"J. Affect. Disord."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"603","DOI":"10.1016\/j.bbi.2017.10.012","article-title":"Depression subtyping based on evolutionary psychiatry: Proximate mechanisms and ultimate functions","volume":"69","author":"Rantala","year":"2018","journal-title":"Brain Behav Immun."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1276","DOI":"10.1111\/apt.13633","article-title":"Systematic review: Current concepts and challenges for the direct-acting antiviral era in hepatitis C cirrhosis","volume":"43","author":"Majumdar","year":"2016","journal-title":"Aliment. Pharm. Ther."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"635","DOI":"10.1111\/jvh.13069","article-title":"Interferon-free therapy as the cause of white matter tracts and cerebral perfusion recovery in patients with chronic hepatitis C","volume":"26","author":"Bladowska","year":"2019","journal-title":"J. Viral Hepat."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"36","DOI":"10.1016\/j.jns.2019.02.002","article-title":"Evaluation of brain volume alterations in HCV-infected patients after interferon-free therapy: A pilot study","volume":"399","author":"Marciniewicz","year":"2019","journal-title":"J. Neurol. Sci."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1128","DOI":"10.4088\/JCP.12r07694","article-title":"Interferon-induced depression in chronic hepatitis C: A systematic review and meta-analysis","volume":"73","author":"Udina","year":"2012","journal-title":"J. Clin. Psychiatry"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"702","DOI":"10.1016\/j.pnpbp.2010.12.017","article-title":"The new \u201c5-HT\u201d hypothesis of depression: Cell-mediated immune activation induces indoleamine 2,3-dioxygenase which leads to lower plasma tryptophan and an increased synthesis of detrimental tryptophan catabolites (TRYCATs), both of which contribute to the onset of depression","volume":"35","author":"Maes","year":"2011","journal-title":"Prog. Neuropsychopharmacol. Biol. Psychiatry"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.psyneuen.2018.06.004","article-title":"Alterations in the metabolism of tryptophan in patients with chronic hepatitis C six months after pegylated interferon-\u03b1 2a treatment","volume":"97","author":"Pawlowski","year":"2018","journal-title":"Psychoneuroendocrinology"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"304","DOI":"10.1016\/j.pnpbp.2013.08.008","article-title":"Network beyond IDO in psychiatric disorders: Revisiting neurodegeneration hypothesis","volume":"48","author":"Myint","year":"2014","journal-title":"Prog. Neuropsychopharmacol. Bio.l Psychiatry"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"E166","DOI":"10.1503\/jpn.190139","article-title":"The role of anthranilic acid in the increase of depressive symptoms and major depressive disorder during treatment for hepatitis C with pegylated interferon-\u03b12a and oral ribavirin","volume":"46","author":"Pawlowski","year":"2021","journal-title":"J. Psychiatry Neurosci."},{"key":"ref_12","first-page":"826","article-title":"The immune effects of TRYCATs (tryptophan catabolites along the IDO pathway): Relevance for depression- and other conditions characterized by tryptophan depletion induced by inflammation","volume":"28","author":"Maes","year":"2007","journal-title":"Neuroendocrinol. Lett."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"105","DOI":"10.1016\/j.jcv.2014.03.004","article-title":"Depression and neuroticism in patients with chronic hepatitis C: Correlation with peripheral blood mononuclear cells activation","volume":"60","author":"Pawlowski","year":"2014","journal-title":"J. Clin. Virol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"100537","DOI":"10.1016\/j.bbih.2022.100537","article-title":"The tryptophan catabolite or kynurenine pathway in major depressive and bipolar disorder: A systematic review and meta-analysis","volume":"26","author":"Almulla","year":"2022","journal-title":"Brain Behav. Immun. Health"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Almulla, A.F., Thipakorn, Y., Vasupanrajit, A., Tunvirachaisakul, C., Oxenkrug, G., Al-Hakeim, H.K., and Maes, M. (2022). The Tryptophan Catabolite or Kynurenine Pathway in a Major Depressive Episode with Melancholia, Psychotic Features and Suicidal Behaviors: A Systematic Review and Meta-Analysis. Cells, 11.","DOI":"10.1101\/2022.08.06.22278492"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1217","DOI":"10.17219\/acem\/104617","article-title":"Biological and psychological components of depression in patients receiving IFN-alpha therapy for hepatitis C","volume":"28","author":"Inglot","year":"2019","journal-title":"Adv. Clin. Exp. Med."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1279","DOI":"10.1053\/j.gastro.2007.02.053","article-title":"Serotonin-1A receptor gene HTR1A variation predicts interferon-induced depression in chronic hepatitis C","volume":"132","author":"Kraus","year":"2007","journal-title":"Gastroenterology"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"344","DOI":"10.1016\/j.biopsych.2008.08.009","article-title":"Risk for depression during interferon-alpha treatment is affected by the serotonin transporter polymorphism","volume":"65","author":"Lotrich","year":"2009","journal-title":"Biol. Psychiatry"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1588","DOI":"10.1176\/ajp.2006.163.9.1588","article-title":"Association of a triallelic serotonin transporter gene promoter region (5-HTTLPR) polymorphism with stressful life events and severity of depression","volume":"163","author":"Zalsman","year":"2006","journal-title":"Am. J. Psychiatry"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"90","DOI":"10.1016\/j.jad.2015.04.056","article-title":"Serotonin gene polymorphisms and lifetime mood disorders in predicting interferon-induced depression in chronic hepatitis C","volume":"183","author":"Cozzolongo","year":"2015","journal-title":"J. Affect. Disord."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"255","DOI":"10.1016\/j.genhosppsych.2013.12.007","article-title":"Serotonin-1A receptor CC genotype is associated with persistent depression related to interferon-alpha in hepatitis C patients","volume":"36","author":"Quarantini","year":"2014","journal-title":"Gen. Hosp. Psychiatry"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1095","DOI":"10.1038\/mp.2008.48","article-title":"Functional polymorphisms in the interleukin-6 and serotonin transporter genes, and depression and fatigue induced by interferon-alpha and ribavirin treatment","volume":"14","author":"Bull","year":"2009","journal-title":"Mol. Psychiatry"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"382","DOI":"10.1192\/bjp.134.4.382","article-title":"A new depression scale designed to be sensitive to change","volume":"134","author":"Montgomery","year":"1979","journal-title":"Br. J. Psychiatry"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"589","DOI":"10.1001\/archpsyc.1990.01810180089012","article-title":"SCAN. Schedules for clinical assessment in neuropsychiatry","volume":"47","author":"Wing","year":"1990","journal-title":"Arch Gen Psychiatry"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"32","DOI":"10.1038\/sj.mp.4000698","article-title":"The human serotonin transporter gene linked polymorphism (5-HTTLPR) shows ten novel allelic variants","volume":"5","author":"Nakamura","year":"2000","journal-title":"Mol. Psychiatry"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"281","DOI":"10.1093\/pubmed\/fdi031","article-title":"Mode of questionnaire administration can have serious effects on data quality","volume":"27","author":"Bowling","year":"2005","journal-title":"J. Public Health"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"S53","DOI":"10.1016\/S0022-510X(98)00203-2","article-title":"Mood disturbances in motor neurone disease","volume":"160","author":"Moore","year":"1998","journal-title":"J. Neurol. Sci."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"8788","DOI":"10.1523\/JNEUROSCI.23-25-08788.2003","article-title":"Impaired repression at a 5-hydroxytryptamine 1A receptor gene polymorphism associated with major depression and suicide","volume":"23","author":"Lemonde","year":"2003","journal-title":"J Neurosci."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"106","DOI":"10.1016\/j.biopsych.2005.06.016","article-title":"Altered serotonin 1A binding in major depression: A [carbonyl-C-11]WAY100635 positron emission tomography study","volume":"59","author":"Parsey","year":"2006","journal-title":"Biol. Psychiatry"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"629","DOI":"10.1038\/jhg.2009.84","article-title":"Serotonin 1A receptor gene and major depressive disorder: An association study and meta-analysis","volume":"54","author":"Kishi","year":"2009","journal-title":"J. Hum. Genet."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"621","DOI":"10.1038\/mp.2008.8","article-title":"Evidence for HTR1A and LHPP as interacting genetic risk factors in major depression","volume":"14","author":"Neff","year":"2009","journal-title":"Mol. Psychiatry"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"874","DOI":"10.1097\/00029330-200805020-00002","article-title":"Association between the serotonin 1A receptor C(-1019)G polymorphism and major depressive disorder in the northern Han ethnic group in China","volume":"121","author":"Wu","year":"2008","journal-title":"Chin. Med. J."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"661","DOI":"10.1002\/ajmg.b.30656","article-title":"Association study between the serotonin 1A receptor (HTR1A) gene and neuroticism, major depression, and anxiety disorders","volume":"147B(5)","author":"Hettema","year":"2008","journal-title":"Am. J. Med. Genet. B Neuropsychiatr. Genet."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1186\/1756-6606-4-21","article-title":"Transcriptional dysregulation of 5-HT1A autoreceptors in mental illness","volume":"4","author":"Albert","year":"2011","journal-title":"Mol. Brain"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"379","DOI":"10.1017\/S1092852915000802","article-title":"Differences in memory function between 5-HT1A receptor genotypes in patients with Major depressive disorder","volume":"21","author":"Wesnes","year":"2016","journal-title":"CNS Spectr."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"e746","DOI":"10.1038\/tp.2015.226","article-title":"The functional serotonin 1a receptor promoter polymorphism, rs6295, is associated with psychiatric illness and differences in transcription","volume":"6","author":"Donaldson","year":"2016","journal-title":"Transl. Psychiatry"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"386","DOI":"10.1126\/science.1083968","article-title":"Influence of life stress on depression: Moderation by a polymorphism in the 5-HTT gene","volume":"301","author":"Caspi","year":"2003","journal-title":"Science"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"5","DOI":"10.1002\/da.21982","article-title":"Serotonin transporter length polymorphism, childhood maltreatment, and chronic depression: A specific gene-environment interaction","volume":"30","author":"Brown","year":"2013","journal-title":"Depress. Anxiety"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"536","DOI":"10.1111\/j.1601-183X.2011.00690.x","article-title":"Serotonin transporter gene variants and prediction of stress-induced risk for psychological distress","volume":"10","author":"Stefanis","year":"2011","journal-title":"Genes Brain Behav."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"224","DOI":"10.1016\/j.biopsych.2005.07.014","article-title":"Social adversity, the serotonin transporter (5-HTTLPR) polymorphism and major depressive disorder","volume":"59","author":"Surtees","year":"2006","journal-title":"Biol. Psychiatry"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"294","DOI":"10.1007\/s10519-006-9139-7","article-title":"Family based association analyses between the serotonin transporter gene polymorphism (5-HTTLPR) and neuroticism, anxiety and depression","volume":"37","author":"Middeldorp","year":"2007","journal-title":"Behav. Genet."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"339","DOI":"10.1016\/j.jad.2017.09.050","article-title":"Gene-environment interactions between stress and 5-HTTLPR in depression: A meta-analytic update","volume":"226","author":"Bleys","year":"2018","journal-title":"J. Affect. Disord."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"133","DOI":"10.1038\/mp.2017.44","article-title":"Collaborative meta-analysis finds no evidence of a strong interaction between stress and 5-HTTLPR genotype contributing to the development of depression","volume":"23","author":"Culverhouse","year":"2018","journal-title":"Mol. Psychiatry"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"274","DOI":"10.1038\/s41398-022-02035-4","article-title":"Time moderates the interplay between 5-HTTLPR and stress on depression risk: Gene x environment interaction as a dynamic process","volume":"12","author":"Borgi","year":"2022","journal-title":"Transl. Psychiatry"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"613","DOI":"10.1001\/archpsyc.59.7.613","article-title":"Association between serotonin transporter gene promoter polymorphism (5HTTLPR) and behavioral responses to tryptophan depletion in healthy women with and without family history of depression","volume":"59","author":"Neumeister","year":"2002","journal-title":"Arch. Gen. Psychiatry"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"978","DOI":"10.1001\/archpsyc.63.9.978","article-title":"Differential Effects of 5-HTTLPR Genotypes on the Behavioral and Neural Responses to Tryptophan Depletion in Patients With Major Depression and Controls","volume":"63","author":"Neumeister","year":"2006","journal-title":"Arch. Gen. Psychiatry"},{"key":"ref_47","first-page":"2005","article-title":"Amino Acid Trp: The Far Out Impacts of Host and Commensal Tryptophan Metabolism","volume":"12","author":"Jenkins","year":"2021","journal-title":"Front. Immunol."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"167","DOI":"10.1016\/S0304-4165(01)00165-9","article-title":"Enzyme activities involved in tryptophan metabolism along the kynurenine pathway in rabbits","volume":"527","author":"Bertazzo","year":"2001","journal-title":"Biochim. Biophys. Acta"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"3648","DOI":"10.1016\/S0021-9258(17)35696-X","article-title":"Tryptophan degradation in mice initiated by indoleamine, 2.; 3-dioxygenas","volume":"261","author":"Takikawa","year":"1986","journal-title":"J. Biol. Chem."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"IJTR-S2097","DOI":"10.4137\/IJTR.S2097","article-title":"Kynurenine pathway metabolites in humans: Disease and healthy states","volume":"2","author":"Chen","year":"2009","journal-title":"Int. J. Tryptophan Res."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"1319","DOI":"10.1007\/s00726-013-1602-1","article-title":"Indoleamine 2, 3-dioxygenase 2 (IDO2) and the kynurenine pathway: Characteristics and potential roles in health and disease","volume":"45","author":"Fatokun","year":"2013","journal-title":"Amino Acids"},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"286","DOI":"10.1016\/j.neuropharm.2016.02.030","article-title":"Kynurenine pathway metabolism and immune activation: Periphermeasurements in psychiatric and co-morbid conditions","volume":"112 Pt B","author":"Strasser","year":"2017","journal-title":"Neuropharmacology"},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"12689","DOI":"10.1038\/srep12689","article-title":"Adaptation of the Human Aryl Hydrocarbon Receptor to Sense Microbiota-Derived Indoles","volume":"5","author":"Hubbard","year":"2015","journal-title":"Sci. Rep."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"17","DOI":"10.1016\/j.it.2015.11.007","article-title":"AHR Function in Lymphocytes: Emerging Concepts","volume":"37","author":"Zhou","year":"2016","journal-title":"Trends Immunol."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"468","DOI":"10.1038\/sj.mp.4000995","article-title":"Association between decreased serum tryptophan concentrations and depressive symptoms in cancer patients undergoing cytokine therapy","volume":"7","author":"Capuron","year":"2002","journal-title":"Mol. Psychiatry"},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1016\/j.brainres.2010.03.057","article-title":"Effect of tryptophan hydroxylase-2 gene variants on amygdalar and hippocampal volumes","volume":"1331","author":"Capuron","year":"2010","journal-title":"Brain Res."},{"key":"ref_57","doi-asserted-by":"crossref","unstructured":"Gao, J., Pan, Z., Jiao, Z., Li, F., Zhao, G., Wei, Q., Pan, F., and Evangelou, E. (2012). TPH2 gene polymorphisms and major depression--a meta-analysis. PLoS ONE, 7.","DOI":"10.1371\/journal.pone.0036721"},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"104517","DOI":"10.1016\/j.neubiorev.2021.104517","article-title":"Meta-analysis of association between TPH2 single nucleotide poiymorphism and depression","volume":"134","author":"Liu","year":"2022","journal-title":"Neurosci. Biobehav. Rev."}],"container-title":["Cells"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2073-4409\/12\/6\/970\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T19:00:56Z","timestamp":1760122856000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2073-4409\/12\/6\/970"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,3,22]]},"references-count":58,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2023,3]]}},"alternative-id":["cells12060970"],"URL":"https:\/\/doi.org\/10.3390\/cells12060970","relation":{},"ISSN":["2073-4409"],"issn-type":[{"value":"2073-4409","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,3,22]]}}}