Fig. 5: Overexpression βFaar protects against HFD-induced β-cell dysfunction.

a Flowchart of the in vivo experiments designed for detecting β-cell function via pancreatic ductal infusion (n = 10), 8-week-old male len-βFaar mice and control mice (Lentivirus pHAGE-CMV-Rat Insulin Promoter (RIP)) were exposed to HFD for 16 weeks. Then, the expression level of βFaar in the islets was measured by qRT-PCR (b, n = 3), fasting insulin levels (FINS) of HFD-fed mice were measured by ELISA (c, n = 10), the level of Homeostatic model assessment indices of insulin resistance (HOMA-IR) (d, n = 10). HOMA-IR was calculated with the equation (FBG (mmol l⁻¹) × FINS (mIU l⁻¹))/22.5. e, f Intraperitoneal glucose tolerance test (IPGTT) (2 g/kg) (e) and intraperitoneal insulin tolerance test (IPITT; 0.75 U/kg) (f) were performed in len-βFaar mice and control mice at the 12th or 14th week of High fat diet administered, respectively. The corresponding area under the curve (AUC) of blood glucose level was calculated (n = 10). g, h Insulin release from islets of len-βFaar mice or control mice after 8-week (g) or 16-week (h) HFD treatment (n = 5). i The TUNEL positive β cells were detected by immunofluorescence after 16-weeks’ HFD treatment. Scale bar, 20 μm. 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 (b–d), and (i), or two-way ANOVA (e–h) are indicated. Data represent the mean ± SD, except (c–f) (mean ± SEM). Source data are provided as a Source data file.