Figure 1.
Elevated palmitate induces profound loss of cAMP signaling in response to α-MSH in N42 hypothalamic neurons and immortalized N2AHA-MC4R-GFP cells. A, N42 cells were treated without or with palmitate at the indicated concentrations for 24 hours. Cells were collected for mRNA isolation and quantitative PCR performed using primers specific to MC4R and actin. Data are shown as the amount of MC4R transcript normalized to that of actin. B, N42 cells were treated with palmitate as in A and then stimulated with 100 nM α-MSH or 1 μM forskolin. Samples were collected to measure cell cAMP levels and protein concentration. C, N2AHA-MC4R-GFP cells were treated with palmitate and the amount of MC4R and HA-MC4R-GFP transcripts, normalized to that of actin, was determined as in A. D, N2AHA-MC4R-GFP cells were treated with palmitate as in A, and cAMP and protein concentration was determined. Data are expressed as mean ± SD. **, P < .01; ***, P < .001.