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Inflammation, hypoxia, and oxidative stress may result in metabolic dysfunction and are directly linked to each other. In the current study, we investigate the effect of hypoxia through NF-\u03baB signaling pathways on iNOS, hypoxia-induced factors (HIF), ROS, and proliferation of normal and KC human corneal fibroblasts (HCFs), in vitro.<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Methods<\/jats:title>\n                <jats:p>Primary human KC-HCFs and normal HCFs were isolated and cultured in DMEM\/Ham\u2019s F12 medium supplemented with 5% fetal calf serum. Hypoxic conditions were generated and quantitative PCR and Western blot analysis were performed to examine NF-\u03baB, iNOS, HIF, and PHD2 expression in KC and normal HCFs. ROS level was analyzed using flow cytometry and proliferation by BrdU-ELISA.<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Results<\/jats:title>\n                <jats:p>Hypoxia increased NF-\u03baB mRNA and protein expression in normal HCFs, but in KC-HCFs NF-\u03baB mRNA and protein expression remained unchanged. Hypoxic conditions upregulated iNOS mRNA expression of normal HCFs, but iNOS mRNA expression of KC-HCFs and iNOS protein expression of both HCF types remained unchanged. Hypoxia downregulated HIF-1\u03b1 and HIF-2\u03b1 mRNA expression in normal and KC-HCFs. PHD2 mRNA expression is upregulated under hypoxia in KC-HCFs, but not in normal HCFs. PHD2 protein expression was upregulated by hypoxia in both HCF types. Total ROS concentration is downregulated in normal and KC-HCFs under hypoxic conditions. Proliferation rate of KC-HCFs was upregulated through hypoxia, but did not change in normal HCFs.<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Conclusions<\/jats:title>\n                <jats:p>Hypoxia increases NF-\u03baB and iNOS mRNA expression in normal HCFs, but there does not seem to be enough capacity in KC-HCFs to increase NF-\u03baB and iNOS mRNA expression under hypoxia, maybe due to the preexisting oxidative stress. HIF and PHD2 do not show altered iNOS regulation under hypoxic conditions in KC-HCFs, and therefore do not seem to play a role in keratoconus pathogenesis. An increased proliferation of cells may refer to compensatory mechanisms under hypoxia in KC. Understanding the mechanism of the altered regulation of NF-\u03baB and iNOS in KC-HCFs will provide better insight into the potential inflammatory component of the KC pathogenesis.<\/jats:p>\n              <\/jats:sec>","DOI":"10.1007\/s00417-020-04900-8","type":"journal-article","created":{"date-parts":[[2020,9,4]],"date-time":"2020-09-04T06:02:41Z","timestamp":1599199361000},"page":"449-458","update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":27,"title":["Hypoxic stress increases NF-\u03baB and iNOS mRNA expression in normal, but not in keratoconus corneal fibroblasts"],"prefix":"10.1007","volume":"259","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7009-7125","authenticated-orcid":false,"given":"Tanja","family":"Stachon","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lorenz","family":"Latta","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Berthold","family":"Seitz","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"N\u00f3ra","family":"Szentm\u00e1ry","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2020,9,4]]},"reference":[{"key":"4900_CR1","doi-asserted-by":"publisher","first-page":"19","DOI":"10.1186\/s40662-016-0051-9","volume":"3","author":"K Nishtala","year":"2016","unstructured":"Nishtala K, Pahuja N, Shetty R et al (2016) Tear biomarkers for keratoconus. 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