Intracellular Ca2+ regulation in a human prostate stromal cell culture

✍ Scribed by C Wu; PM Fry; G Sui; CH Fry

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 188 KB
• Volume: 24
• Category: Article
• ISSN: 0733-2467
• DOI: 10.1002/nau.20088

✦ Synopsis

Aims: Prostate stromal cell cultures are used in vitro to study the cellular pathophysiology of benign prostatic hyperplasia (BPH), but their functional properties are poorly understood. This study characterized intracellular Ca 2þ ([Ca 2þ ] i ) regulation in a cultured cell line in comparison to freshly isolated cells, as a background to understanding contractile regulation and cellular proliferation in this tissue. Methods: Prostate stromal cells were isolated from either PrS6 cell cultures, with an extended life span by transfection with the SV40 T-antigen, tsA58-U19, or freshly obtained transition zone prostate samples, primary cells. [Ca 2þ ] i was measured in vitro with the indicator Fura-2 by epi£uorescence microscopy. Results: Phenylephrine, high-K þ , and ca¡eine induced Ca 2þ -transients in primary cells (resting [Ca 2þ ] i 94 AE 8 nM, n ¼ 29; peak 193 AE 26 nM, n ¼ 19). In PrS6 cells resting [Ca 2þ ] i was 96 AE 8 nM (n ¼ 78) and in 34 of these 78 cells, 30 mM phenylephrine increased [Ca 2þ ] i to 296 AE 28 nM. 5-methyl-urapidil (10 ^30 mM) inhibited this response in 10 of 16 cells. Spontaneous Ca 2þ -transients were also observed in 91% of phenylephrine-responsive cells, but in only 20% of non-responsive cells (P < 0.01). Ca 2þ -transients were also induced by high-K þ solution, and 20 mM ca¡eine. The latter abolished the response to subsequent phenylephrine application. Depletion of intracellular Ca 2þ stores by ca¡eine or restoration from a Ca 2þ -free superfusate caused a substantial rise of [Ca 2þ ] i . Conclusions: PrS6 prostate stromal cells express functional a 1 -adrenoceptors associated with spontaneous intracellular Ca 2þ -transients. They exhibit functional Ca 2þ channels, intracellular Ca 2þ stores, and Ca 2þ entry induced by store depletion. Stromal cultures can therefore be used to characterize the cellular physiology of prostate stromal cell contraction and proliferation.