Publications by authors named "Bae-Kuen Park"

3 Publications

  • Page 1 of 1

5α-dihydrotestosterone reduces renal expression suppression of progesterone receptor.

J Mol Endocrinol 2018 02;60(2):159-170

College of Veterinary Medicine, Chungnam National University, Daejeon, Republic of Korea.

Androgens act in concert with vitamin D to influence reabsorption of calcium. However, it is unclear whether androgens directly regulate vitamin D homeostasis or control other cellular events that are related to vitamin D metabolism. To examine whether the expression of vitamin D-related genes in mouse kidney is driven by androgens or androgen-dependent effects, the androgen receptor and other sex steroid receptors were monitored in orchidectomized mice treated with 5α-dihydrotestosterone (DHT). Our results revealed that exposing orchidectomized mice to DHT inhibited the expression of progesterone receptor (Pgr) with or without estrogen receptor α expression, the latter was confirmed by ER-positive (MCF7 and T47D) or -negative (PCT) cells analysis. The loss of Pgr in turn decreased the expression of renal 24-hydroxylase transcriptional regulation because gene has a progesterone receptor-binding site on promoter. When male kidneys preferentially hydroxylate 25-hydroxyvitamin D using 24-hydroxylase rather than 25-hydroxyvitamin D-1-alpha hydroxylase, DHT suppressed the Pgr-mediated 24-hydroxylase expression, and it is important to note that DHT increased the blood 25-hydroxyvitamin D levels. These findings uncover an important link between androgens and vitamin D homeostasis and suggest that therapeutic modulation of Pgr may be used to treat vitamin D deficiency and related disorders.
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http://dx.doi.org/10.1530/JME-17-0187DOI Listing
February 2018

Hydroxylation and sulfation of sex steroid hormones in inflammatory liver.

J Biomed Res 2017 Sep;31(5):437-444

College of Veterinary Medicine, Chungnam National University, Daejeon, Republic of Korea.

Sex steroids, also known as gonadal steroids, are oxidized with hydroxylation by cytochrome P450, glucuronidation by UDP-glucuronosyltransferase, sulfation by sulfotransferase, andO-methylation by catechol O-methyltransferase. Thus, it is important to determine the process by which inflammation influences metabolism of gonadal hormones. Therefore, we investigated the mechanism of metabolic enzymes against high physiologic inflammatory responsein vivo to study their biochemical properties in liver diseases. In this study, C57BL/6N mice were induced with hepatic inflammation by diethylnitrosamine (DEN) exposure. We observed upregulation of Cyp19a1, Hsd17b1, Cyp1a1, Sult1e1 in the DEN-treated livers compared to the control-treated livers using real time PCR. Moreover, the increased Cyp19a1 and Hsd17b1 levels support the possibility that estrogen biosynthesis from androgens are accumulated during inflammatory liver diseases. Furthermore, the increased levels of Cyp1a1 and Cyp1b1 in the hydroxylation of estrogen facilitated the conversion of estrogen to 2- or 4-hydroxyestrogen, respectively. In addition, the substantial increase in the Sult1e1 enzyme levels could lead to sulfate conjugation of hydroxyestrogen. The present information supports the concept that inflammatory response can sequester sulfate conjugates from the endogenous steroid hormones and may suppress binding of sex steroid hormones to their receptors in the whole body.
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http://dx.doi.org/10.7555/JBR.31.20170031DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5706436PMC
September 2017

Prevalence and sequence analyses of Neorickettsia risticii.

Ann N Y Acad Sci 2003 Jun;990:248-56

Bio-safety Research Institute, College of Veterinary Medicine, Chonbuk National University, Jeonju, Jeonbuk 561-756, Korea.

The presence of Neorickettsia (Ehrlichia) risticii DNA was confirmed by PCR amplification and sequence analysis from cercaria in snails collected from stream water in Chungcheong and Jeonra provinces. A total of 3,219 snails were tested for trematode cercariae and N. risticii infection. N. risticii 16S rRNA gene fragment was amplified in cercariae from Semisulcospira libertina and Radix auricularia coreana snails by nested PCR. More than four genus cercariae (Schistosomatidae, Microphallidae, Furcocercus, and Xiphidiocercaria) as well as unidentified cercariae were found from Semisulcospira libertina snails. Three species of cercariae (E. cinetorichis, E. hortense, and Fasciola sp.) were found from Radix auricularia coreana snails. The cercariae were present in 429 (13.3%) snails of 3,216 collected at the Chungcheong and Jeonra provinces. The prevalence of N. risticii in these 429 cercariae was 17.9% (77 of 429 cercariae-infected snails). The amplicons of N. risticii 16S rRNA gene fragment (527 bp) from cercariae DNA had two genotypes (NR-JA1 and NR-JA2) with an identity of 96.4% between their nucleotide sequences. However, when compared to the sequence of N. risticii Shasta strain these sequences showed a 94.3% and 96.4% homology, respectively. The comparison of N. risticii 51 kDa major antigen gene sequences (572 bp) from NR-JA1 and NR-JA2 were 100% identical to the sequence of the isolates from Juga sp., Caddisfly larvae, Shasta, Juga yrekaensis, and trematode of California. This study reports for the first time the detection of N. risticii from cercariae found in Radix auricularia coreana snail. These data also indicate that N. risticii could be widespread in Korea.
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http://dx.doi.org/10.1111/j.1749-6632.2003.tb07372.xDOI Listing
June 2003
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