Fig. 2: Obesity-induced reduced expression of βFaar via DNMT3a and DNMT3b.

MIN6 cells and mice primary islets were incubated with 0.5 mmol/l palmitate (a) and a combination of interleukin-1β (IL-1β, 5 ng/ml) and tumor necrosis factor-α (TNF-α, 30 ng/ml, b) for 48 h and qRT-PCR was performed to examine the βFaar levels. The expression levels of βFAAR in human islets incubated with 0.5 mmol/l palmitate (c) and a combination of interleukin-1β (IL-1β, 5 ng/ml) and tumor necrosis factor-α (TNF-α, 30 ng/ml, d), e MIN6 cells were incubated with different doses of 5-Aza-dC (0.5 µmol/l, 2 µmol/l, and 8 µmol/l) and qRT-PCR was performed to analyze the expression levels of βFaar. f One BSP regions of the βFaar promoter CpG island in the islet of db/db mice (n = 6). Each box indicates the methylation status of the CpG site. Each row represents an individual sequenced DNA strand. Over 20 clones from each mixed sample were sequenced. The percentage of methylation in each sequenced region was indicated. g–h The protein levels of DNMT1, DNMT3a, and DNMT3b in the islet of db/db mice (g) and HFD mice (h, n = 5). i MIN6 cells were incubated with 0.5 mmol/l palmitate and co-transfected with si-Dnmt3a or si-Dnmt3b, followed by qRT-PCR to examine the expression levels of βFaar. All experiments above were performed in triplicates, and each group contained three batches of individual samples. The p-values by two-tailed unpaired Student’s t test (c, d, f), one-way ANOVA (i) or two-way ANOVA (a, b, e) are indicated. Data represent the mean ± SD. Source data are provided as a Source data file.