{"type": "root", "children": [{"type": "p", "children": [{"type": "t", "text": "\n Human chorionic gonadotropin (hCG) is recognized as the first placental hormone to communicate with the maternal organism shortly after implantation, and its bioactivity is largely determined by its β‐subunit. One representative gene from the multi‐copy CGB cluster—CGB3—encodes a β‐subunit whose proper expression and post‐translational glycosylation are essential for hCG’s diverse functions. The hCG β‐subunit sustains the corpus luteum by stimulating progesterone secretion and thereby supports early pregnancy. In addition, hCG modulates both autocrine and paracrine pathways by promoting syncytiotrophoblast formation, facilitating trophoblast invasion, and enhancing placental angiogenesis. These activities are finely tuned by changes in glycosylation; for instance, hyperglycosylated forms of hCG produced by invasive extravillous trophoblasts are associated with early trophoblast invasion and vascular remodeling."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "1"}]}, {"type": "t", "text": " \n "}]}, {"type": "t", "text": "\n "}, {"type": "p", "children": [{"type": "t", "text": "\n Moreover, the genomic context of the LHB/CGB gene cluster, within which CGB3 resides, is evolutionarily dynamic, and its organization directly influences the transcriptional output of hCG β‐subunit genes. This genetic arrangement plays a rate‐limiting role in hormone assembly and adds complexity to the regulation of hCG production."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "2"}]}, {"type": "t", "text": " Perturbations in these regulatory networks—including those mediated by transcription factors such as STOX1—have been implicated in adverse pregnancy outcomes such as preeclampsia, where abnormal hCG glycoforms may contribute to placental dysfunction."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "3"}]}, {"type": "t", "text": "\n "}]}, {"type": "t", "text": "\n "}, {"type": "p", "children": [{"type": "t", "text": "\n In summary, CGB3, as a constituent of the hCG β‐subunit gene cluster, plays a critical multifunctional role in pregnancy. By governing both hormonal and local regulatory actions—ranging from the maintenance of corpus luteum function to the regulation of trophoblast differentiation, invasion, and angiogenesis—the protein it encodes is essential for proper placental development and successful pregnancy outcome.\n "}]}, {"type": "rg", "children": [{"type": "r", "ref": 1, "children": [{"type": "t", "text": "T Fournier, J Guibourdenche, D Evain-Brion "}, {"type": "b", "children": [{"type": "t", "text": "Review: hCGs: different sources of production, different glycoforms and functions."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Placenta (2015)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1016/j.placenta.2015.02.002"}], "href": "https://doi.org/10.1016/j.placenta.2015.02.002"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "25707740"}], "href": "https://pubmed.ncbi.nlm.nih.gov/25707740"}]}, {"type": "r", "ref": 2, "children": [{"type": "t", "text": "Liina Nagirnaja, Kristiina Rull, Liis Uusküla, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Genomics and genetics of gonadotropin beta-subunit genes: Unique FSHB and duplicated LHB/CGB loci."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Mol Cell Endocrinol (2010)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1016/j.mce.2010.04.024"}], "href": "https://doi.org/10.1016/j.mce.2010.04.024"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "20488225"}], "href": "https://pubmed.ncbi.nlm.nih.gov/20488225"}]}, {"type": "r", "ref": 3, "children": [{"type": "t", "text": "Virginie Rigourd, Caroline Chauvet, Sonia T Chelbi, et al. "}, {"type": "b", "children": [{"type": "t", "text": "STOX1 overexpression in choriocarcinoma cells mimics transcriptional alterations observed in preeclamptic placentas."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "PLoS One (2008)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1371/journal.pone.0003905"}], "href": "https://doi.org/10.1371/journal.pone.0003905"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "19079545"}], "href": "https://pubmed.ncbi.nlm.nih.gov/19079545"}]}]}]}