Figure 1

Nonylphenol and polyethoxylates promote adipogenesis in human mesenchymal stem cell models. Zenbio and Lonza human bone marrow–derived mesenchymal stem cell models were differentiated as described in Methods and assessed for adipocyte differentiation (Nile Red staining of lipid accumulation) and cell proliferation (Hoechst staining) after 14/21 (respectively) days of differentiation while exposed to controls chemicals as well as nonylphenol and its ethoxylates. Percent normalized triglyceride accumulation per cell relative to maximal rosiglitazone response (normalized to DNA content) (A,C). increase (cell proliferation) or decrease (potential cytotoxicity) in DNA content relative to vehicle control (B,D). Zenbio–sourced cell data provided in (A,B), and Lonza–sourced cell data provided in (C,D). Data presented as mean ± SEM from three independent experiments. * indicates lowest concentration with significant increase in triglyceride over vehicle control or cell proliferation/cytotoxicity relative to vehicle control, p < 0.05, as per Kruskal–Wallis in GraphPad Prism 9. X–axis format is provided in log scale. Panel (E) provides a summary plot of maximal effects on triglyceride accumulation based on ethoxylate chain length across cell models, comparing results from panels (A,C) with previously published effects in 3T3–L1 cells (PMID: 29106673). NPEO = nonylphenol polyethoxylated (with varying average ethoxylate chain lengths).