Journal: iScience

Article Title: Exendin-4 promotes retinal ganglion cell survival and function by inhibiting calcium channels in experimental diabetes

doi: 10.1016/j.isci.2023.107680

Figure Lengend Snippet: Ex-4 suppressed I LCa in RGCs via GLP-1R (A) Real-time quantitative RT-PCR analysis showing a significant decrease in GLP-1 mRNA levels in DM retinas (n = 6, ∗∗∗∗p < 0.0001 by unpaired t test). Beta-2-microglobulin was used as a house-keeping gene. (B) Representative current recordings from an acutely isolated RGC. The cell was held at −40 mV, and the high-voltage activated Ca 2+ currents were induced by depolarization voltage pulses from −30 mV to +10 mV in increments of 10 mV. The currents were almost completely suppressed by 10 μM nimodipine. (C) Bar chart summarizing the changes of current amplitudes after nimodipine application (n = 8). (D) Representative I LCa traces of an RGC, showing that extracellular application of Ex-4 (200 nM) suppressed the current amplitudes. (E) Current–voltage (I–V) relationship curves showing that Ex-4 voltage-dependently suppressed the I LCa amplitudes (n = 9). (F and G) Current traces and bar chart showing the effect of Ex-4 on I LCa recorded at −10 mV (n = 9). (H) Ex-4 suppressed I LCa in a dose-dependent manner. Only one concentration of Ex-4 was tested for a single cell. Each cell was recorded before Ex-4 perfusion (control) and during Ex-4 perfusion, and each Ex-4 response was then normalized against its corresponding control response, which is always 100%. Cell numbers are marked inside the bars. (I) Representative currents showing that 100 nM Ex-9-39 blocked the Ex-4 induced suppression of I LCa . (J) Bar chart summarizing the effects of Ex-9-39 and Ex-4 on I LCa obtained at −10 mV (n = 8). Data are presented as mean ± SD. n.s., p > 0.05, ∗p < 0.05, ∗∗p < 0.01 and ∗∗∗∗p < 0.0001 by paired t test.

Article Snippet: Exendin-9-39 , MedChemExpress , Cat#HY-P0264.

Techniques: Quantitative RT-PCR, Isolation, Concentration Assay

Journal: iScience

Article Title: Exendin-4 promotes retinal ganglion cell survival and function by inhibiting calcium channels in experimental diabetes

doi: 10.1016/j.isci.2023.107680

Figure Lengend Snippet: Brn3a-labeled RGCs in control, DM and different drug-treated retinas (A1–C3) Fluorescence micrographs from the peripheral, middle and central regions in flat-mount retinas showing Brn3a-labeled surviving RGCs in normal (A1–C1), DM eyes treated with (A3–C3) or without saline (A2–C2). (A4–C7) Fluorescence micrographs from the peripheral, middle and central regions in flat-mounted retinas depicting Brn3a-labeled RGCs in DM eyes treated with Ex-4 (A4–C4), Ex-9-39+Ex-4 (A5–C5), BayK-8644 (A6–C6), or BayK-8644+Ex-4 (A7–C7). Topical administration of Ex-4 increased RGC viability in the peripheral and middle regions of the retinas (A4, B4). Administration of Ex-9-39 (A5, B5) or BayK-8644 (A7, B7) blocked the protective effects of Ex-4 on RGCs. Scale bar: 50 μm.

Article Snippet: Exendin-9-39 , MedChemExpress , Cat#HY-P0264.

Techniques: Labeling, Fluorescence, Saline

Journal: iScience

Article Title: Exendin-4 promotes retinal ganglion cell survival and function by inhibiting calcium channels in experimental diabetes

doi: 10.1016/j.isci.2023.107680

Figure Lengend Snippet: Quantitative analysis of the density of surviving RGCs (A–C) Schematic diagrams of flat-mount retinas, illustration of 12 areas of RGC quantification (4 peripheral, 4 middle and 4 central, indicated by green squares). (D–F) Quantitative analysis of the density of surviving RGCs in the peripheral (D), middle (E) and central regions (F) of retinas from control, DM eyes, saline-treated DM eyes, Ex-4-treated DM eyes, DM eyes treated with Ex-4+Ex-9-39, BayK-8644, or Ex-4+BayK-8644. Retina numbers are noted in the bars. Data are presented as mean ± SD, ∗p < 0.05, ∗∗∗p < 0.001 and ∗∗∗∗p < 0.0001 vs. control; †p < 0.05 and †††p < 0.001 vs. DM + Saline by Tukey’s multiple comparisons test after one-way ANOVA.

Article Snippet: Exendin-9-39 , MedChemExpress , Cat#HY-P0264.

Techniques: Saline