{"database":"GEO","file_versions":[{"headers":{"Content-Type":["application/json"]},"body":{"files":{"Other":["ftp://ftp.ncbi.nlm.nih.gov/geo/series/GSE335nnn/GSE335748/"]},"type":"primary"},"statusCode":"OK","statusCodeValue":200}],"scores":null,"additional":{"omics_type":["Transcriptomics"],"species":["Homo sapiens"],"gds_type":["Expression profiling by high throughput sequencing"],"full_dataset_link":["https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE335748"],"repository":["GEO"],"entry_type":["GSE"],"additional_accession":[]},"is_claimable":false,"name":"The Core Subunit NDUFS2 in Mitochondrial Complex I is Critical to Oxygen Sensing in Human Ductus Arteriosus Smooth Muscle Cells","description":"Rationale: Mitochondria in ductus arteriosus smooth muscle cells (DASMC) are oxygen sensors triggering vasoconstriction at birth; however, the mitochondrial oxygen sensing mechanisms are not fully understood. Given the conserved role of mitochondrial Complex I subunit NDUFS2 in other oxygen-sensing tissues, we examined its role in DASMC oxygen sensing, comparing it to other Complex I subunits (NDUFS1 and NDUFS7) and putative O2-sensor subunits (UQCRFS1 and COX4I2). Methods: Human DASMC were grown in hypoxia (pO2=41mmHg). Oxygen responsiveness was assessed, measuring oxygen-induced changes in intracellular calcium, [Ca2+]i, cell length, and mitochondrial reactive oxygen species (mROS) production. DASMC were treated for 48-hours with control or targeting. Knockdown was confirmed using qPCR and immunoblot. 3’RNA sequencing assessed molecular changes following siRNA manipulation. Results: Oxygen increased mitochondrial fission, [Ca2+]I, and constricted DASMC. 48-hours post-treatment, siNDUFS2 selectively depressed oxygen-induced increase in [Ca2+]i (siControl +18.6±2.3%, siNDUFS2 +5.5±1.5%, p<0.0001), DASMC shortening (from 18.4±1.1% to 8.9±0.8%, p<0.0001), and mROS (+24±4.9% untreated, -6.6±5.4% siNDUFS2, p<0.0001), without altering the KCl response or depressing respiration. The mitochondrial antioxidant MitoTEMPO reduced mROS (2.9±4.5%, p=0.001) and attenuated oxygen-induced cell shortening (8.4±0.9%, p=0.0003). Transcriptomics revealed distinct changes in mitochondrial pathways 48-hours post siNDUFS2. Conclusions: NDUFS2 regulates mROS and is a mitochondrial oxygen sensor in human DASMC.","dates":{"publication":"2026/07/27"},"accession":"GSE335748","cross_references":{"GSM":["GSM9819891","GSM9819892","GSM9819893","GSM9819894","GSM9819895","GSM9819896","GSM9819897","GSM9819898","GSM9819890","GSM9819910","GSM9819899","GSM9819911","GSM9819912","GSM9819913","GSM9819884","GSM9819885","GSM9819886","GSM9819887","GSM9819907","GSM9819908","GSM9819909","GSM9819888","GSM9819900","GSM9819889","GSM9819901","GSM9819902","GSM9819903","GSM9819904","GSM9819905","GSM9819906"],"GPL":["21697"],"GSE":["335748"],"taxon":["Homo sapiens"]}}