Expression of mRNAs encoding the α1 and the β1 subunits of Na⁺,K⁺‐ATPase in human lymphocytes activated with phytohaemagglutinine

Abstract

Increase in Na+,K+‐ATPase mRNAs was detected in activated lymphocytes by the RT‐PCR method. α1 subunit mRNA gradualy increased with time and by 36 h was 2.4 times higher than at the start. Increase in the β1 mRNA was transient reaching a maximum in the 8 h probe and declining to the initial level in the 24 and 36 h probes. The elevation of Na+,K−‐ATPase mRNAs does not underlie a cycloheximide‐inhibited increase in cation pumping peculiar to the prereplicative period as can be judged from the fact that Act D fails to eliminate PHA‐induced enhancement of pump fluxes.

Long‐term enhancement of Na,K‐ATPase pump during blasttransformation of human lymphocytes is controlled first by translational, then by transcriptional mechanisms

“…It has recently been found that the induction of mitogenic response in human lymphocytes is accompanied by an elevated level of Na,K-ATPase mRNAs at 8 h of PHA stimulation, i.e. well ahead of the growth-related activation of Na,K-ATPase pump [14]. Such an early expression of Na,K-ATPase mRNAs might underlie the activation of cation pump associated with the cell cycle progression.…”

“…Our recent studies on human lymphocytes activated by phytohemagglutinin (PHA) have shown that the long-term increase in pump-mediated K fluxes is limited to the prereplicative stage and coincides in time with the blasttransformation of lymphocytes [7]. It has been suggested that the enhanced cation pumping is an essential element of the whole program of cell transition from quiescence to proliferation.…”

Digoxin-Like Immunoreactive Factors Induce Apoptosis in Human Acute T-Cell Lymphoblastic Leukemia

“…( Table 1). PCC tissue produces the 3 NKA ␣ subunits (␣1, ␣2, and ␣3) (22 ), whereas Jurkat cells produce at least the ␣1 and ␣2 subunits (25 ). Whether the ␣3 subunit is also produced in this cell line is not known and needs to be evaluated in future studies.…”

Differential Transcription of Ion Transporters, NHE1, ATP1B1, NKCC1 in Human Peripheral Blood Lymphocytes Activated to Proliferation

“…The data presented in this paper show an increase in the levels of mRNAs encoding the β subunit of the Na,K-ATPase pump (ATP1B1) and Na/H antiporter (NHE1), as well as kinase hSGK in lymphocytes activated with PHA for 8-24 h. According to the literature and our own findings, this time interval corresponds to the prereplicative stage of the lymphocyte activation [6][7][8][9][10][11][12][13]25]. Thus, mRNAs encoding these ion transporters and kinase hSGK should be included into the list of mRNAs upregulated at the prereplicative stage of the transit of cells from quiescence to proliferation [16, 17,].…”

“…Stimulation of lymphocytes also activates ion transport [3][4][5][6][7][8][9][10][11][12]. As shown for the Na,KATPase pump in activated lymphocytes, regulation of transport involves not only activation [4,[6][7][8][9][10] and the elevated number of expressed pump units [5], but also an increase in the level of pump mRNAs [13]. Preliminary data indicate [14,15] that, like other genes [16,17], the Na/H antiporter may be under a transcriptional control during the lymphocyte activation.…”