Fig. 4: The influence of histamine on autophagy is dependent on H1R.
a H9c2 cells were treated with 10 μM histamine under hypoxia condition for 12 h. The mRNA expression of histamine receptors was analyzed by qRT-PCR. The results were normalized to that of GAPDH. b H9c2 cells were treated with as a. The expression levels of H1R and H2R were confirmed by immunoblot. Representative photos and the densitometric analysis are shown. c Cells were treated with 10 μM Histamine along with 1 μM H1R antagonist (pyrilamine) or 50 μM H2R antagonist (cimetidine) for 12 h under hypoxia condition. The autophagy-related proteins, LC3 and p62, were analyzed by immunoblot and the densitometric analysis of the bands is shown. d H9c2 cells were transfected with plasmids encoding GFP-LC3 for 8 h and then treated as c. The percentage of cells with GFP-LC3 puncta was quantified. e From 3 days before AMI surgery, pyrilamine (10 mg/kg/d) or cimetidine (10 mg/kg/d) were administered intraperitoneally daily until euthanasia in WT mice. The levels of LC3 and p62 were analyzed by immunoblot at 3d after surgery. Representative photos and the densitometric analysis of the bands are shown as the upper panels. Quantitative analysis of autophagic cells analyzed by electron microscopy is shown at the below panel. n = 5 for the sham group and n = 8 for each of MI groups. f From 3 days before AMI surgery, histamine (4 mg/kg/d) with pyrilamine (10 mg/kg/d) or cimetidine (10 mg/kg/d) were administered intraperitoneally daily until euthanasia in HDC−/− mice. LC3 and p62 were analyzed by immunoblot at 3d after surgery. Representative photos and the densitometric analysis of the bands are shown as the upper panels. Quantitative analysis of autophagic cells analyzed by electron microscopy is shown at the below panel. n = 5 for the sham group and n = 8 for each of MI groups. *P < 0.05; **P < 0.01
