The Comparison of Placental mRNA Expression of 11β-Hydroxysteroid Dehydrogenases

Presenter Information

Chihiro Yagi, Minnesota State University, Mankato
Saadia Ranginwala, Minnesota State University, Mankato

Location

CSU Ballroom

Start Date

21-4-2008 1:00 PM

End Date

21-4-2008 3:00 PM

Student's Major

Chemistry and Geology

Student's College

Science, Engineering and Technology

Mentor's Name

Theresa Salerno

Mentor's Department

Chemistry and Geology

Mentor's College

Science, Engineering and Technology

Second Mentor's Name

James E. Rife

Second Mentor's Department

Chemistry and Geology

Second Mentor's College

Science, Engineering and Technology

Third Mentor's Name

Penny Knoblich

Third Mentor's Deparment

Biological Sciences

Third Mentor's College

Science, Engineering and Technology

Description

11β-hydroxysteroid dehydrogenases (11β-HSDs) are enzymes that control the active levels of glucocorticoids. Since the glucocorticoids can bind to the mineralocorticoid receptors, they can mimic aldosterone and cause hypertension. 11β-HSD exists in two isozyme forms, 11β-HSD 1 and 11β-HSD 2. 11β-HSD 1 catalyzes the activation and deactivation of the glucocorticoids reversibly while 11β -HSD2 catalyzes the reaction that inactivates the glucocorticoids. Many studies suggest that maternal hormone levels affect fetal development and the expression of hormones in the offspring. Therefore, it is important to study enzymes that regulate maternal hormones such as 11β-HSDs. In our research, the expressions of 11β-HSD1 and 11β-HSD2 in rat placenta were studied by analyzing the levels of the corresponding messenger RNAs (mRNAs). These pregnant rats were either normotensive (WKY) or hypertensive (SHR). Some were treated to lower aldosterone levels and others (the shams) were not. The rat placentae in full-term pregnancy were obtained and frozen by liquid nitrogen. Total RNAs were isolated from the frozen placental tissue using the Qiagen RNeasy kit. The expressions of the two mRNAs were determined by reverse transcription, followed by specific polymerase chain reaction amplifications (RT-PCR) using multiple cycles in the linear range of amplification. The amplified cDNAs were separated by gel electrophoresis and silver stained. The bands indicating 11β-HSD and 18S primer/competimer were measured by the densitometer, and then the data were normalized. Using this approach, ratios of HSD 1/ HSD 2 were obtained and compared to see if lowered aldosterone levels trigger expression changes in these isoenzymes that control glucocorticoid activity.