CheMyong Ko

3810 VMBSB
Office: 217-333-9362

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CheMyong Ko

Associate Professor, Comparative Biosciences

Neural and hormonal regulation of ovulation

The program of ovulation is activated by a surge of luteinizing hormone (LH). This LH surge then induces dramatic changes in the molecular, biochemical and physical aspects of the ovary, which eventually lead to the rupture of follicle, releasing an egg. Ovulatory failure has been associated with the development of numerous disorders such as polycystic ovarian syndrome (PCOS), hemorrhagic cyst formation and hormonal imbalance, all of which are major risk factors for women’s health including fertility defect. The long-term objective of my research is to elucidate the mechanism governing the breakdown and rupture of the follicle during the ovulatory process. The followings are 3 specific areas of my research interests: (1) Endothelin system in regulating ovulation, (2) steroids and prostaglandins in regulating ovulatory leukocyte infiltration and (3) key regulators of PCOS pathogenesis. The research will be mostly performed using in vivo animal models at both molecular and physiological levels. Both intra-institutional and extra-institutional collaborations will always be sought to bring advanced expertise to the research projects. Once novel findings are made from the animal studies, established collaboratory networks will be used to translate them into human benefits.

Research Area

Representative Publications

2014, Joseph Cacioppo, Sang-Wook Oh, Hey-young Kim, Jongki Cho, Po-Ching Lin, Masashi Yanagisawa and CheMyong Ko. Loss of Function of Endothelin-2 leads to Reduced Ovulation and CL Formation. Plos One 24;9(4);e96115 (PMID:24763822).

2014, Arnon Gal, Po-Ching Lin, Anne Barger, Amy MacNeill, CheMyong Ko. Vaginal fold histology reduces the variability introduced by vaginal exfoliative cytology in the classification of mouse estrous cycle stages. In press. (PMID:24705880).

2014, Thomas Gawriluk, CheMyong Ko, Xiaoman Hong, Lane Christenson, Edmund Rucker III. Beclin-1 deficiency in the murine ovary results in the reduction of progesterone production to promote preterm labor. PNAS 111(40):E4194-203 (PMID: 25246579).

2014, Novaira HJ1, Sonko ML, Hoffman G, Koo Y, CheMyong Ko, Wolfe A, Radovick S. Disrupted kisspeptin signaling in GnRH neurons leads to hypogonadotrophic hypogonadism. Molecular Endocrinology 28(2):225-238 (PMID: 24422632).

2014, Sheng Wu, Sara DiVall, Amanda Nwaopara, Sally Radovick, Fredric Wondisford, CheMyong Ko, Andrew Wolfe. Obesity induced infertility and hyperandrogenism are corrected by deletion of the insulin receptor in the ovarian theca cell. Diabetes 63(4):1270-82 (PMID: 24379345).

2013, Giyoun Na, Andrew Wolfe, CheMyong Ko, Hyesook Youn, Young-Min Lee, Sung June Byun, Iksoo Jeon and Youngbum Koo. A low-copy-number plasmid for retrieval of Toxic Genes from BACs and Generation of Conditional Targeting Constructs. Mol Biotechnol. 54(2):504-14 (PMID: 22945876)

2013, Sanz E, Evanoff R, Quintana A, Evans E, Miller JA, CheMyong Ko, Amieux PS, Griswold MD, McKnight GS. RiboTag Analysis of Actively Translated mRNAs in Sertoli and Leydig Cells In Vivo. PLoS One. 2013 Jun 11;8(6):e66179 (PMID: 23776628)

2012, CheMyong Ko*, Rina Meidan and Phillip Bridges. Why two endothelins and two receptors for ovulation and luteal regulation? Life Sci. 91:501-6 (PMID: 22677434)

2012, Seung-Yon Lee, Eunsook Park, Seung-Chang Kim, Ryun-Sup Ahn, CheMyong Ko, Keesook Lee. ERa/E2 signaling suppresses the expression of steroidogenic enzyme genes via cross-talk with orphan nuclear receptor Nur77 in the testes. Mol Cell Endocrinol. 362 (1-2):91-103 (PMCID: 22683664) 2012, José E. Sánchez-Criado, Kourtney Trudgen, Yolanda Millán, Alfonso Blanco, José C. Garrido-Gracia, Rafaela Aguilar, José Monterde, Juana Martín de las Mulas and CheMyong Ko. Estrogen receptor (ESR) 2 partially offsets the absence of ESR1 in gonadotropes of pituitary-specific ESR1 knockout female mice. Reproduction 143(4):549-58. (PMID: 22367588)

2012, Jongki Cho, Heyyoung Kim, Dong-Wook Kang, Masashi Yanagisawa and CheMyong Ko*. Endothelin B receptor is not required but necessary for finite regulation of ovulation. Life Sci. 91(13-14): 613-7. (PMID: 22406076).

2012, Phillip J. Bridges, Myoungkun Jeoung, Sarah Shim, Ji Yeon Park, Jae Eun Lee, Lindsay A. Sapsford, Kourtney Trudgen, CheMyong Ko, Myung Chan Gye and Misung Jo. Hematopoetic prostaglandin D synthase: an ESR1-dependent oviductal epithelial cell synthase. Endocrinology 153(4): 1925-35 (PMID 22374975).