{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,29]],"date-time":"2026-09-29T19:41:24Z","timestamp":1790710884850,"version":"4.1.0"},"reference-count":40,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2019,8,18]],"date-time":"2019-08-18T00:00:00Z","timestamp":1566086400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Primary open-angle glaucoma (POAG) represents the leading cause of irreversible blindness worldwide and is a multifactorial, chronic neurodegenerative disease characterized by retinal ganglion cell and visual field loss. There are many factors that are associated with the risk of developing POAG, with increased intraocular pressure being one of the most prevalent. Due to the asymptomatic nature of the disease, the diagnosis of POAG often occurs too late, which necessitates development of new effective screening strategies for early diagnosis of the disease. However, this task still remains unfulfilled. In order to provide further insights into the pathophysiology of POAG, we applied a targeted metabolomics strategy based on a high-throughput screening method for the determination of tear amino acids, free carnitine, acylcarnitines, succinylacetone, nucleosides, and lysophospholipids in na\u00efve to therapy glaucomatous patients and normal controls. Also, we conducted proteomic analyses of the whole lacrimal fluid and purified extracellular vesicles obtained from POAG patients and healthy subjects. This multi-omics approach allowed us to conclude that POAG patients had lower levels of certain tear amino acids and lysophospholipids compared with controls. These targeted analyses also highlighted the low amount of acetylcarnitine (C2) in POAG patient which correlated well with proteomics data. Moreover, POAG tear proteins seemed to derive from extracellular vesicles, which carried a specific pro-inflammatory protein cargo.<\/jats:p>","DOI":"10.3390\/ijms20164029","type":"journal-article","created":{"date-parts":[[2019,8,19]],"date-time":"2019-08-19T06:10:14Z","timestamp":1566195014000},"page":"4029","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":81,"title":["Multi-Omics Approach for Studying Tears in Treatment-Na\u00efve Glaucoma Patients"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0949-0280","authenticated-orcid":false,"given":"Claudia","family":"Rossi","sequence":"first","affiliation":[{"name":"Center for Advanced Studies and Technology (CAST), University \u2018\u2018G. d\u2019Annunzio\u2019\u2019 of Chieti-Pescara, 66100 Chieti, Italy"},{"name":"Department of Medical, Oral and Biotechnological Sciences, University \u2018\u2018G. d\u2019Annunzio\u2019\u2019 of Chieti-Pescara, 66100 Chieti, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9792-2225","authenticated-orcid":false,"given":"Ilaria","family":"Cicalini","sequence":"additional","affiliation":[{"name":"Center for Advanced Studies and Technology (CAST), University \u2018\u2018G. d\u2019Annunzio\u2019\u2019 of Chieti-Pescara, 66100 Chieti, Italy"},{"name":"Department of Medicine and Aging Science, \u201cG. d\u2019Annunzio\u201d University of Chieti-Pescara, 66100 Chieti, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6457-7795","authenticated-orcid":false,"given":"Maria Concetta","family":"Cufaro","sequence":"additional","affiliation":[{"name":"Center for Advanced Studies and Technology (CAST), University \u2018\u2018G. d\u2019Annunzio\u2019\u2019 of Chieti-Pescara, 66100 Chieti, Italy"},{"name":"Department of Pharmacy, University \u2018\u2018G. d\u2019Annunzio\u2019\u2019 of Chieti-Pescara, 66100 Chieti, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Luca","family":"Agnifili","sequence":"additional","affiliation":[{"name":"Department of Medicine and Aging Science, \u201cG. d\u2019Annunzio\u201d University of Chieti-Pescara, 66100 Chieti, Italy"},{"name":"Opthalmic Clinic, Ss Annunziata Hospital, 66100 Chieti, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Leonardo","family":"Mastropasqua","sequence":"additional","affiliation":[{"name":"Department of Medicine and Aging Science, \u201cG. d\u2019Annunzio\u201d University of Chieti-Pescara, 66100 Chieti, Italy"},{"name":"Opthalmic Clinic, Ss Annunziata Hospital, 66100 Chieti, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Paola","family":"Lanuti","sequence":"additional","affiliation":[{"name":"Department of Medicine and Aging Science, \u201cG. d\u2019Annunzio\u201d University of Chieti-Pescara, 66100 Chieti, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marco","family":"Marchisio","sequence":"additional","affiliation":[{"name":"Department of Medicine and Aging Science, \u201cG. d\u2019Annunzio\u201d University of Chieti-Pescara, 66100 Chieti, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Vincenzo","family":"De Laurenzi","sequence":"additional","affiliation":[{"name":"Center for Advanced Studies and Technology (CAST), University \u2018\u2018G. d\u2019Annunzio\u2019\u2019 of Chieti-Pescara, 66100 Chieti, Italy"},{"name":"Department of Medical, Oral and Biotechnological Sciences, University \u2018\u2018G. d\u2019Annunzio\u2019\u2019 of Chieti-Pescara, 66100 Chieti, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1653-2194","authenticated-orcid":false,"given":"Piero","family":"Del Boccio","sequence":"additional","affiliation":[{"name":"Center for Advanced Studies and Technology (CAST), University \u2018\u2018G. d\u2019Annunzio\u2019\u2019 of Chieti-Pescara, 66100 Chieti, Italy"},{"name":"Department of Pharmacy, University \u2018\u2018G. d\u2019Annunzio\u2019\u2019 of Chieti-Pescara, 66100 Chieti, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Damiana","family":"Pieragostino","sequence":"additional","affiliation":[{"name":"Center for Advanced Studies and Technology (CAST), University \u2018\u2018G. d\u2019Annunzio\u2019\u2019 of Chieti-Pescara, 66100 Chieti, Italy"},{"name":"Department of Medical, Oral and Biotechnological Sciences, University \u2018\u2018G. d\u2019Annunzio\u2019\u2019 of Chieti-Pescara, 66100 Chieti, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2019,8,18]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2271","DOI":"10.1016\/j.ophtha.2009.06.042","article-title":"Natural history of open-angle glaucoma","volume":"116","author":"Heijl","year":"2009","journal-title":"Ophthalmology"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2081","DOI":"10.1016\/j.ophtha.2014.05.013","article-title":"Global prevalence of glaucoma and projections of glaucoma burden through 2040: A systematic review and meta-analysis","volume":"121","author":"Tham","year":"2014","journal-title":"Ophthalmology"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"381","DOI":"10.3389\/fimmu.2019.00381","article-title":"Autoantibody Biomarker Discovery in Primary Open Angle Glaucoma Using Serological Proteome Analysis (SERPA)","volume":"10","author":"Beutgen","year":"2019","journal-title":"Front. Immunol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/bs.pbr.2015.05.006","article-title":"Molecular biomarkers in primary open-angle glaucoma: From noninvasive to invasive","volume":"221","author":"Agnifili","year":"2015","journal-title":"Prog. Brain Res."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"121","DOI":"10.1167\/iovs.12-11067","article-title":"Molecular biomarkers in glaucoma","volume":"54","author":"Bhattacharya","year":"2013","journal-title":"Investig. Ophthalmol. Vis. Sci."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"e132","DOI":"10.1111\/j.1755-3768.2011.02255.x","article-title":"Conjunctival findings in hyperbaric and low-tension glaucoma: An in vivo confocal microscopy study","volume":"90","author":"Agnifili","year":"2012","journal-title":"Acta Ophthalmol."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Pieragostino, D., Agnifili, L., Cicalini, I., Calienno, R., Zucchelli, M., Mastropasqua, L., Sacchetta, P., Del Boccio, P., and Rossi, C. (2017). Tear Film Steroid Profiling in Dry Eye Disease by Liquid Chromatography Tandem Mass Spectrometry. Int. J. Mol. Sci., 18.","DOI":"10.3390\/ijms18071349"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1186\/s13167-016-0065-3","article-title":"Tear fluid biomarkers in ocular and systemic disease: Potential use for predictive, preventive and personalised medicine","volume":"7","author":"Hagan","year":"2016","journal-title":"EPMA J."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Cicalini, I., Rossi, C., Pieragostino, D., Agnifili, L., Mastropasqua, L., di Ioia, M., De Luca, G., Onofrj, M., Federici, L., and Del Boccio, P. (2019). Integrated Lipidomics and Metabolomics Analysis of Tears in Multiple Sclerosis: An Insight into Diagnostic Potential of Lacrimal Fluid. Int. J. Mol. Sci., 20.","DOI":"10.3390\/ijms20061265"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"649","DOI":"10.1016\/j.clinbiochem.2008.02.017","article-title":"A decade of HPLC-MS\/MS in the routine clinical laboratory\u2014Goals for further developments","volume":"41","author":"Vogeser","year":"2008","journal-title":"Clin. Biochem."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Gelb, M.H., Lukacs, Z., Ranieri, E., and Schielen, P. (2019). Newborn Screening for Lysosomal Storage Disorders: Methodologies for Measurement of Enzymatic Activities in Dried Blood Spots. Int. J. Neonatal Screen., 5.","DOI":"10.3390\/ijns5010001"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"677","DOI":"10.1515\/CCLM.2011.109","article-title":"Confirmation of congenital adrenal hyperplasia by adrenal steroid profiling of filter paper dried blood samples using ultra-performance liquid chromatography-tandem mass spectrometry","volume":"49","author":"Rossi","year":"2011","journal-title":"Clin. Chem. Lab. Med."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Monostori, P., Klinke, G., Richter, S., Barath, A., Fingerhut, R., Baumgartner, M.R., Kolker, S., Hoffmann, G.F., Gramer, G., and Okun, J.G. (2017). Simultaneous determination of 3-hydroxypropionic acid, methylmalonic acid and methylcitric acid in dried blood spots: Second-tier LC-MS\/MS assay for newborn screening of propionic acidemia, methylmalonic acidemias and combined remethylation disorders. PLoS ONE, 12.","DOI":"10.1371\/journal.pone.0184897"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"103403","DOI":"10.1016\/j.jprot.2019.103403","article-title":"Proteomics characterization of extracellular vesicles sorted by flow cytometry reveals a disease-specific molecular cross-talk from cerebrospinal fluid and tears in multiple sclerosis","volume":"204","author":"Pieragostino","year":"2019","journal-title":"J. Proteom."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"4355","DOI":"10.1167\/iovs.18-24938","article-title":"A Metabolomics Profiling of Glaucoma Points to Mitochondrial Dysfunction, Senescence, and Polyamines Deficiency","volume":"59","author":"Leruez","year":"2018","journal-title":"Investig. Ophthalmol. Vis. Sci."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"6735","DOI":"10.1038\/s41598-019-43203-9","article-title":"Vision-related quality of life and symptom perception change over time in newly-diagnosed primary open angle glaucoma patients","volume":"9","author":"Riva","year":"2019","journal-title":"Sci. Rep."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1159\/000479158","article-title":"Clinical Metabolomics and Glaucoma","volume":"59","author":"Himmelreich","year":"2018","journal-title":"Ophthalmic. Res."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1307","DOI":"10.1021\/acs.jproteome.8b00915","article-title":"Metabolomic Profiling of Aqueous Humor in Glaucoma Points to Taurine and Spermine Deficiency: Findings from the Eye-D Study","volume":"18","author":"Buisset","year":"2019","journal-title":"J. Proteome Res."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"5020","DOI":"10.1167\/iovs.15-16702","article-title":"Metabolome-Wide Association Study of Primary Open Angle Glaucoma","volume":"56","author":"Burgess","year":"2015","journal-title":"Investig. Ophthalmol. Vis. Sci."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"84","DOI":"10.1016\/j.exer.2014.11.012","article-title":"Metabolomics of the aqueous humor in the rat glaucoma model induced by a series of intracamerular sodium hyaluronate injection","volume":"131","year":"2015","journal-title":"Exp. Eye Res."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Vohra, R., Dalgaard, L.M., Vibaek, J., Langbol, M.A., Bergersen, L.H., Olsen, N.V., Hassel, B., Chaudhry, F.A., and Kolko, M. (2019). Potential metabolic markers in glaucoma and their regulation in response to hypoxia. Acta Ophthalmol.","DOI":"10.1111\/aos.14021"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"e62","DOI":"10.1038\/cddis.2010.40","article-title":"Carnitine reduces the lipoperoxidative damage of the membrane and apoptosis after induction of cell stress in experimental glaucoma","volume":"1","author":"Calandrella","year":"2010","journal-title":"Cell Death Dis."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Iyer, P., Lalane, R., Morris, C., Challa, P., Vann, R., and Rao, P.V. (2012). Autotaxin-lysophosphatidic acid axis is a novel molecular target for lowering intraocular pressure. PLoS ONE, 7.","DOI":"10.1371\/journal.pone.0042627"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"181","DOI":"10.1089\/jop.2013.0194","article-title":"Bioactive lysophospholipids: Role in regulation of aqueous humor outflow and intraocular pressure in the context of pathobiology and therapy of glaucoma","volume":"30","author":"Rao","year":"2014","journal-title":"J. Ocul. Pharmacol. Ther. Off. J. Assoc. Ocul. Pharmacol. Ther."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"3037","DOI":"10.1167\/iovs.12-10517","article-title":"Comparative phospholipid profiles of control and glaucomatous human trabecular meshwork","volume":"54","author":"Aribindi","year":"2013","journal-title":"Investig. Ophthalmol. Vis. Sci."},{"key":"ref_26","first-page":"1966","article-title":"Sphingolipids and ceramides in human aqueous humor","volume":"19","author":"Aljohani","year":"2013","journal-title":"Mol. Vis."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1108","DOI":"10.1039\/c3mb25463a","article-title":"Shotgun proteomics reveals specific modulated protein patterns in tears of patients with primary open angle glaucoma naive to therapy","volume":"9","author":"Pieragostino","year":"2013","journal-title":"Mol. Biosyst."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"143","DOI":"10.1016\/j.neuroscience.2014.03.042","article-title":"The effects of N-acetyl-cysteine and acetyl-L-carnitine on neural survival, neuroinflammation and regeneration following spinal cord injury","volume":"269","author":"Karalija","year":"2014","journal-title":"Neuroscience"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"5340","DOI":"10.1038\/srep05340","article-title":"Novel common variants and susceptible haplotype for exfoliation glaucoma specific to Asian population","volume":"4","author":"Nakano","year":"2014","journal-title":"Sci. Rep."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"205","DOI":"10.1038\/nature02783","article-title":"Cytoplasmic PML function in TGF-beta signalling","volume":"431","author":"Lin","year":"2004","journal-title":"Nature"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"680","DOI":"10.1136\/bjophthalmol-2011-301132","article-title":"The role of transforming growth factor beta in glaucoma and the therapeutic implications","volume":"97","author":"Prendes","year":"2013","journal-title":"Br. J. Ophthalmol."},{"key":"ref_32","first-page":"1201","article-title":"Mutual regulation of the Hippo\/Wnt\/LPA\/TGFbeta signaling pathways and their roles in glaucoma (Review)","volume":"41","author":"Wang","year":"2018","journal-title":"Int. J. Mol. Med."},{"key":"ref_33","first-page":"712","article-title":"TGF-beta-induced IOP elevations are mediated by RhoA in the early but not the late fibrotic phase of open angle glaucoma","volume":"24","author":"Hill","year":"2018","journal-title":"Mol. Vis."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"390","DOI":"10.1097\/IJG.0000000000000627","article-title":"Targeting Transforming Growth Factor-beta Signaling in Primary Open-Angle Glaucoma","volume":"26","author":"Wang","year":"2017","journal-title":"J. Glaucoma"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.neurobiolaging.2016.03.005","article-title":"Medium-chain plasma acylcarnitines, ketone levels, cognition, and gray matter volumes in healthy elderly, mildly cognitively impaired, or Alzheimer\u2019s disease subjects","volume":"43","author":"Ciavardelli","year":"2016","journal-title":"Neurobiol. Aging"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"121","DOI":"10.1007\/s00592-017-1074-y","article-title":"Proteomic and metabolomic characterization of streptozotocin-induced diabetic nephropathy in TIMP3-deficient mice","volume":"55","author":"Rossi","year":"2018","journal-title":"Acta Diabetol."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Rossi, C., Cicalini, I., Zucchelli, M., di Ioia, M., Onofrj, M., Federici, L., Del Boccio, P., and Pieragostino, D. (2018). Metabolomic Signature in Sera of Multiple Sclerosis Patients during Pregnancy. Int. J. Mol. Sci., 19.","DOI":"10.3390\/ijms19113589"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"929","DOI":"10.1053\/j.ajkd.2013.04.007","article-title":"Effect of an L-carnitine-containing peritoneal dialysate on insulin sensitivity in patients treated with CAPD: A 4-month, prospective, multicenter randomized trial","volume":"62","author":"Bonomini","year":"2013","journal-title":"Am. J. Kidney Dis."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"1794","DOI":"10.1021\/pr101065j","article-title":"Andromeda: A peptide search engine integrated into the MaxQuant environment","volume":"10","author":"Cox","year":"2011","journal-title":"J. Proteome Res."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"523","DOI":"10.1093\/bioinformatics\/btt703","article-title":"Causal analysis approaches in Ingenuity Pathway Analysis","volume":"30","author":"Kramer","year":"2014","journal-title":"Bioinformatics"}],"container-title":["International Journal of Molecular Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1422-0067\/20\/16\/4029\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T13:11:58Z","timestamp":1760188318000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1422-0067\/20\/16\/4029"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,8,18]]},"references-count":40,"journal-issue":{"issue":"16","published-online":{"date-parts":[[2019,8]]}},"alternative-id":["ijms20164029"],"URL":"https:\/\/doi.org\/10.3390\/ijms20164029","relation":{},"ISSN":["1422-0067"],"issn-type":[{"value":"1422-0067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,8,18]]}}}