Fig 2: LCA inhibited H-L-HFD-induced liver fibrosis through regulating insulin resistance signaling pathway. Mice were divided into 4 groups, H-L + HFD, H-L + HFD + INSR inhibitor, H-L + HFD + INSR inhibitor + LCA and H-L + HFD + INSR inhibitor + IA. Liver tissues were collected at 5th week post HFD synergizes H-L radiation or LCA or IA setting. A. Timeline of mice subjected to H-L + HFD, H-L + HFD + INSR inhibitor, H-L + HFD + INSR inhibitor + LCA and H-L + HFD + INSR inhibitor + IA. B. AST level. C. ALT level. D. TC level. E. TG level. F. LDL level. G. HDL level. H. Immunohistochemistry detection for PI3K, Akt and NFkB in liver tissues. Scale bar:50 μm. I. Western blot analysis (and J. quantification) of effect of LCA (50 mg/kg) on liver fibrosis-related proteins, E-cadherin, N-cadherin a-SMA expression in mice. K. Quantification of liver inflammation-related mRNA expression. L. E-cadherin, N-cadherin and a-SMA mRNA expression in mice liver tissues with or without radiation and IA treatment were detected by qRT-PCR. M. E-cadherin, N-cadherin and a-SMA mRNA expression in mice lung tissues with or without radiation and IA treatment were detected by qRT-PCR. Data are means ± standard deviation (SD). Mann-Whitney test or two-tailed unpaired Student's t-test were used for statistical analyses*p < 0.05 indicates significant difference.

Fig 3: Progerin/prelamin A down-regulates IGF-1R and impairs IGF-1/Akt signaling.(A) IF analysis of green fluorescent protein (GFP) showing exogenous GFP-progerin (arrows) within NIH 3T3-L1 cells. Scale bar, 10 μm. (B) Flow cytometric analysis of GFP showing the mean fluorescence intensity of NIH 3T3-L1 cells treated with conditioned medium for 3 hours. (C) Growth curves and Western blot analysis of NIH 3T3-L1 cells treated with conditioned medium. (D and E) SA-β-gal staining showing cellular senescence (blue staining) (D) and statistical analysis of SA-β-gal–positive cells from 10 randomly chosen fields (E) of WT MEFs treated with conditioned medium at passage 5. Scale bar, 20 μm. (F) Western blot analysis of WT MEFs treated with conditioned medium at passage 5. (G and H) Mitochondrial respiration (G) and ATP-linked respiration (H) in WT MEFs treated with conditioned medium for 24 hours. (I) Western blot analysis of IGF-1 stimulated activation of Akt in MCF-7 or HEK293T cells treated with progerin or in WT and Zmpste24−/− MEFs. (J) IP and Western blot analysis of the interaction between progerin and IGF-1Rβ in human HGPS cells. (K and L) In vitro interaction between IGF-1Rβ and glutathione S-transferase (GST)–progerin (K) or GST–lamin A truncates (L). (M) Western blot analysis of IGF-1R in HEK293T cells or MCF-7 cells treated with IGF-1 or progerin for 6 hours. (N) Western blot analysis of IGF-1R and InsR in MEFs at passage 4, hearts of 1-month-old WT and Zmpste24−/− mice, and muscle and adipose tissue from 2-month-old WT and Zmpste24−/− mice. Each lane represents a different mouse. In (G) and (H), OCR, oxygen consumption rate; FCCP, carbonyl cyanide p-trifluoromethoxyphenylhydrazone. In (K) and (L), the asterisks indicate the corresponding protein bands. In (B), (C), (H), and (N), bars indicate means ± SEM, n = 3. *P < 0.05, **P < 0.01, and ***P < 0.001.

Fig 4: Impact of Exoc6/6b silencing on the expression of β-cell function genes. Total mRNA/protein was extracted from Exoc6/6b-silenced cells or siRNA negative control after 48 h of transfection and subjected for qPCR or western blot analysis. qPCR expression analysis of Ins1, Ins2, Pdx1, NeuroD1, Gck, Glut2, InsR and Vamp2 in Exoc6-silenced cells (A) or Exoc6b-silenced cells (B) compared to control cells. Western blot analysis of Pro/insulin, PDX1, NEUROD1, PDX1, GLUT2, GCK, INSβ and VAMP2 relative to the endogenous control protein β-actin in Exoc6-silenced cells (C) or Exoc6b-silenced cells (D). Data were obtained from three independent experiments (Supplementary Figures S1–S3). *; p < 0.05. **; p < 0.01. n.s.; not significant. Bars represent mean ± SD.

Fig 5: Expression profile of RARs in human pancreatic islets. (A) microarray mean gene expression of RARα, β, γ, and KCNJ11 in nondiabetic/normoglycemic human islets (n. of donors = 45) as determined on Human Gene 1.0 ST array. (B) RNA-seq gene expression of RARα, β, γ, and KCNJ11 in nondiabetic/normoglycemic human islets (n. of donors = 50). (C) Western blot expression of RARβ was obtained from non-diabetic human islets (n = 1; purchased from Prodo Lab. Inc, Maple Plain, MI, USA). Differential expression patterns of RARβ (D), RARα (E), and RARγ (F) in nondiabetic/normoglycemic (n. of donors = 50) versus diabetic/hyperglycemic (n. of donors = 25) human islets. Spearman’s expression correlation of RARβ with INS (G), PDX1 (H), INSR (I), and HbA1c levels (J) (n. of donors = 50). Expression levels are presented as mean ± SD. Full western blot figures are available in Supplementary File.