Journal: Molecular Neurobiology
Article Title: Metformin Ameliorates Early Brain Injury After Subarachnoid Hemorrhage Via Improving Endoplasmic Reticulum Stress and Mitochondrial Stress-Mediated Ca 2+ Imbalance
doi: 10.1007/s12035-025-05558-1
Figure Lengend Snippet: Met significantly suppressed Ca 2+ transfer from the ER to the mitochondria through the PTP1B/AKT following SAH 24 h in vitro. A – K Our vitro data demonstrate that PTP1B plays a critical role in integrating ER stress with mitochondrial dysfunction following SAH 24 h. Representative Western blot band and densitometric quantification of PTP1B, p-AKT, AKT, p-eIF2a, eIF2a, IP3R1, GRP75, VDAC1, ATF4, and CHOP in primary neurons induced by the OxyHb. The expression of the IP3R1–GRP75–VDAC1 complex was upregulated accordingly. ns P > 0.05, * P < 0.05. Values were presented as the mean ± SD from four independent experiments ( N = 4). Samples derived from the same experiment, and the gels were processed in parallel. Protein expression levels were normalized to GAPDH as an internal control. Individual gels were run for the separate proteins when the loading protein amount was consistent. L Conventional immunofluorescence confirmed the colocalization of NEUN, MAP-2, and DAPI in primary neurons. Scale bar = 50 μm. M – R The effect of Met on the apoptosis of SAH in vitro. Representative Western blot bands of Bcl-2, Bax, CC3, and flow cytometry were used to evaluate the effect of Met on apoptosis in vivo. ns P > 0.05, * P < 0.05. Values were presented as the mean ± SD from four independent experiments ( N = 4). Protein expression levels were normalized to GAPDH as an internal control. S The conventional immunofluorescence staining showed that the colocalization of intracellular Ca 2+ concentration increased significantly in the OxyHb24H group in primary neurons. Scale bar = 50 μm. T The conventional immunofluorescence confirmed the colocalization of PTP1B, calnexin, VDAC1, and DAPI in primary neurons after the intervention of lentivirus and inhibitors. To assess the effect of Met on MAM integrity, we performed immunofluorescence co-localization analysis of the ER marker calnexin and the mitochondrial marker VDAC1 in treated primary neurons. Scale bar = 50 μm. An unpaired Student’s t test was used for comparisons between two groups, whereas ANOVA followed by Tukey’s post hoc test was used for comparisons among multiple groups
Article Snippet: The PVDF membrane was blocked in 5% skim milk for 90 min at room temperature, followed by incubation with the primary antibodies against PTP1B (1:2000 Proteintech, catalog number 11334–1-AP), IP3R1 (1:2000, Abcam, catalog number ab264281), CHOP (1:1000, Proteintech, catalog number 15204–1-AP), Bcl-2 (1:2000, Affinity, lot# 70g9181), Bax (1:2000, Proteintech, catalog number 50599–2-2 g), VDAC1 (1:2000, Proteintech, catalog number 10866–1-AP), AKT (1:1000 Proteintech, catalog number 10176–2-AP), p-AKT (1:1000 Proteintech, catalog number 80455–1-RR), GRP75 (1:1000, Bio-Techne, catalog number MAB3584, ATF4 (1:2000, Proteintech, catalog number 10835–1-AP, p- eIF2a (1:500, Affinity, catalog number AF3087), eIF2a (1:1000, Proteintech, catalog number 11170–1-AP), and CC3 (1:1000, Bioss, Boston, MA, USA lot: BJ03319208), respectively.
Techniques: In Vitro, Western Blot, Expressing, Derivative Assay, Control, Immunofluorescence, Flow Cytometry, In Vivo, Staining, Concentration Assay, Marker