Quantitative real-time reverse transcriptase (qRT-PCR) was used to analyze the expression of the following genes (PMCA1, PMCA4, SERCA1, and SERCA2) using 2 [micro]L of template cDNA.
To determine if this increase is due to an increase in PMCA mRNA or protein expression, we focused on the two PMCA isoforms known to be expressed in VSM cells, PMCA1 and PMCA4 .
To assess the expression levels of the different [Ca.sup.2+] channels and transporters in human VSM cells, we used real-time PCR to evaluate mRNA levels of PMCA1, PMCA4, Orail, Orai2, stim1, STIM2, and SERCA1-3.
The primary cellular targets of caspase 3 are the cytoplasmic domain of the B3 (cdB3), the [Na.sup.+]/[H.sup.+] exchanger (NHE1), and the 4 plasma membrane [Ca.sup.2+]-ATPase (PMCA4) [17-19].
PMCA4 cleavage causes irreversible activation of the [Ca.sup.2+] transport activity of the enzyme .
Caspase 3 catalyzes the specific cleavage of cdB3, NHE1, and PMCA4. The cdB3 and NHE1 cleavage contributes to the alteration of the hydrogen ions concentration, as HC[O.sub.3.sup.-]/[Cl.sup.-] exchange occurs in conjugation with the [Na.sup.+]/[H.sup.+] antiporter .