oa Phenylephrine induced Na+/H+ exchanger isoform 1 expression modulates cell viability in human embryonic kidney (HEK 293) cells.

Background: Na+/H+-exchanger isoform 1 (NHE1) is a ubiquitously expressed housekeeping glycoprotein that functions to regulate intracellular pH. Current reports have suggested that NHE1 is crucial to cell survival in the context of chronic kidney disease. The cellular mechanism by which NHE1 stimulates cell survival requires further investigation. Osteopontin (OPN), is a macrophage chemotactic protein that has been linked to tissue injury in non‐diabetic kidney disease. Whether expression of NHE1 counteracts the role of osteopontin in human embryonic kidney (HEK 293) cells remains to be elucidated. Objective: To establish whether upregulation of NHE1 expression counteracts the negative effects of osteopontin expression in HEK 293. Results: Our results did not reveal protein expression of NHE1 or OPN in HEK 293 under basal conditions. However, the HEK 293 cells overexpressed both NHE1 and OPN following 24-hour stimulation with PE (10uM). The expression of both NHE1 and OPN did not significantly alter the cell viability of the HEK 293 cells. This was verified using trypan blue. Conclusion: NHE1 activation in HEK 293 cells acts as a defense mechanism against apoptotic stress.