Prolactin specifically increases pyruvate dehydrogenase E1 alpha in rat lateral prostate epithelial cells

Area of Science:

• Endocrinology
• Molecular Biology
• Urology

Background:

• Prolactin regulates prostate citrate production, but the mechanisms are unclear.
• Key enzymes for citrate synthesis include mitochondrial aspartate aminotransferase (mAAT) and pyruvate dehydrogenase E1 alpha (PDH E1 alpha).
• Previous studies showed prolactin affects mAAT; this study investigates PDH E1 alpha regulation.

Purpose of the Study:

• To determine if prolactin regulates PDH E1 alpha in rat prostate epithelial cells.
• To elucidate the specific prostate lobes affected by prolactin's regulatory effects.
• To investigate the mechanism of prolactin's effect on PDH E1 alpha levels.

Main Methods:

• Administered prolactin to rats and analyzed PDH E1 alpha levels in lateral (LP), ventral (VP), and dorsal (DP) prostate epithelial cells.
• Conducted in vitro studies exposing isolated LP, VP, and DP epithelial cells to prolactin.
• Utilized actinomycin and cycloheximide to assess the role of protein biosynthesis in prolactin's effect.

Main Results:

• Prolactin administration increased PDH E1 alpha levels in LP epithelial cells within 6 hours.
• Prolactin had no significant effect on PDH E1 alpha levels in VP or DP epithelial cells.
• In vitro prolactin exposure increased PDH E1 alpha in LP cells, but not VP or DP cells; this effect was blocked by actinomycin and cycloheximide.

Conclusions:

• Prolactin specifically stimulates PDH E1 alpha levels in rat lateral prostate epithelial cells.
• Testosterone specifically stimulates PDH E1 alpha levels in ventral prostate epithelial cells.
• Prolactin and testosterone likely increase PDH E1 alpha gene expression in their respective prostate lobes, influencing citrate synthesis.