1‐Naphthaleneacetic Acid Improved the In Vitro Cell Culturing by Inhibiting Apoptosis

Abstract In vitro cell culturing witnessed its applications in scientific research and industrial activities. Attempts to shorten the doubling time of cultured cells have never ceased. In plants, auxin is applied to promote plant growth, the synthetic derivative 1‐Naphthaleneacetic acid (NAA) is a good example. Despite the auxin's naturally occurring receptors are not present in mammalian cells, studies suggested they may affect cell culturing. Yet the effects and mechanisms are still unclear. Here, an up to 2‐fold increase in the yield of in vitro cultured human cells is observed. Different types of human cell lines and primary cells are tested and found that NAA is effective in all the cells tested. The PI staining followed by FACS suggested that NAA do not affect the cell cycling. Apoptosis‐specific dye staining analysis implicated that NAA rescued cell death. Further bulk RNA sequencing is done and it is identified that the lipid metabolism‐engaging and anti‐apoptosis gene, ANGPTL4, is enhanced in expression upon NAA treatment. Studies on ANGPTL4 knockout cells indicated that ANGPTL4 is required for NAA‐mediated response. Thus, the data identified a beneficial role of NAA in human cell culturing and highlighted its potency in in vitro cell culturing.