ARG1 and hyperlipidemia: As shown in Figure 5E, we found that hyperlipidemia simulated by a 24-h in vitro incubation with 0.125 mM palmitate significantly increased the mRNA expression of both chitinase 3-like protein 3 (Ym1) and arginase 1—two markers of alternative activation of immune cells [22], while LPS, known to induce classical activation of microglia, significantly reduced the expression of arginase 1 after 24 h (Figure 5F).