Journal: Nature Communications
Article Title: Restoration of PITPNA in Type 2 diabetic human islets reverses pancreatic beta-cell dysfunction
doi: 10.1038/s41467-023-39978-1
Figure Lengend Snippet: a Representative transmission electron micrographs of pancreatic beta-cells from non-diabetic human donors after lentiviral-mediated over-expression of PITPNA (OE- PITPNA ) or inhibition of PITPNA (sh- PITPNA ) in comparison to respective control lentiviruses (OE- Ctrl or sh- Ctrl ). The second raw image represents a zoom-in view of the white box from the first raw image. Granule profile: immature secretory granules (blue box), mature secretory granules (red box), crystal-containing granules (yellow box), and empty secretory granules (orange box). b Quantification of granule density in beta-cells of lentiviral-treated human islets shown in panel ( a ) ( n = 9). P sh-Ctrl vs sh-PITPNA = 0.0199, P OE-Ctrl vs OE-PITPNA < 0.0001. c Quantifi c ation of docked vesicles in beta-cells of lentiviral-treated human islets shown in panel ( a ) ( n = 9). P sh-Ctrl vs sh-PITPNA = 0.0004, P OE-Ctrl vs OE-PITPNA = 0.00421. d Quantification of immature secretory granules (ISG, n = 7, 8, 5, 6 for sh- Ctrl , sh- PITPNA , OE- Ctrl , OE- PITPNA , respectively), mature secretory granules (MSG, n = 8, 8, 8, 6 for sh- Ctrl , sh- PITPNA , OE- Ctrl , OE- PITPNA , respectively), crystal-containing granules (CCG, n = 6, 8, 8, 8 for sh- Ctrl , sh- PITPNA , OE- Ctrl , OE- PITPNA , respectively), and empty secretory granules (ESG, n = 7, 7, 7, 7 for sh- Ctrl , sh- PITPNA , OE- Ctrl , OE- PITPNA , respectively) in beta-cells of isolated human islets after lentiviral treatments shown in panel ( a ). ( P sh-Ctrl vs sh-PITPNA < 0.0001, P OE-Ctrl vs OE-PITPNA = 0.0128 for ISG), ( P sh-Ctrl vs sh-PITPNA < 0.0001, P OE-Ctrl vs OE-PITPNA = 0.0008 for MSG), ( P sh-Ctrl vs sh-PITPNA = 0.0068, P OE-Ctrl vs OE-PITPNA = 0.6874 for CCG), ( P sh-Ctrl vs sh-PITPNA = 0.0207, P OE-Ctrl vs OE-PITPNA = 0.4262 for ESG). e Proinsulin expression in isolated human islets after lentiviral-mediated over-expression of PITPNA (OE- PITPNA , n = 5 biologically independent samples), knockdown of PITPNA (sh- PITPNA , n = 7 biologically independent samples) or control lentivirus (sh- Ctrl , n = 7 biologically independent samples). f Quantification of proinsulin in isolated human islets after densitometric analysis of western blots shown in panel ( f ). g Western blot analysis of PITPNA, and ER stress/unfolded protein response (UPR) proteins IRE1α, ERO1, PDI, and CHOP in human islets after lentiviral-mediated over-expression of PITPNA (OE- PITPNA ), knockdown of PITPNA (sh- PITPNA ) or control lentivirus (sh- Ctrl ). Data are presented as mean values ± SEM for ( b ), ( c ), ( d ), e ). * P < 0.05, ** P < 0.01, *** P < 0.001. Ordinary one-way ANOVA with Turkey’s multiple comparisons test was used for ( b ), ( c ), ( d ), ( e ). All primary source data are reported in the Source data file.
Article Snippet: The following primary antibodies were used for Western blots at 1:1000 dilution: PITPNA (Abcam, ab180234), Cadm1 (MBL, CM004-3), Gephyrin (BD Biosciences, 610585), CHOP (Cell Signaling, 2895S), BiP/GRP78 (Cell Signaling, 3177S), DRP1 (Proteintech, 12957-1-AP), β-Actin (Cell Signaling, 3700S), and γ-Tubulin (Sigma, T6557).
Techniques: Transmission Assay, Over Expression, Inhibition, Comparison, Control, Isolation, Expressing, Knockdown, Western Blot