Fig. 1.

Genes from insulin-secreting cells modulated by stress (serum deprivation) and HDLs. A, βTC3 cells were grown for 2 d in complete medium, washed twice with 3 ml PBS, and incubated for 72 h in the presence or in the absence of 1 mm HDL-cholesterol in either complete medium or in medium lacking serum. Apoptosis was then quantified. The results correspond to the mean ± sem of two independent experiments performed in triplicate and that involved two different preparations of HDLs. Asterisks denote a statistically significant difference with the control condition (vehicle only). Pound signs indicate a statistically significant difference with the vehicle + starvation condition. The threshold of significance was at P = 0.010 (five comparisons for each HDL preparation). B, βTC3 cells were treated as described in panel A except that the cells were subjected to the indicated conditions for 6 h. After RNA extraction, the cRNA was prepared separately for each condition and hybridized to Affymetrix mouse 430 version 2 gene chip (Affymetrix). The numbers of genes significantly (adjusted P < 0.05) up- or down-regulated by HDLs, serum deprivation, or those the modulation by serum deprivation of which was altered by HDLs (interaction of both) are listed. See Materials and Methods for details. Prep., Preparation.