Fig. 3

hNSC-Exos alleviated neuronal injury after middle cerebral artery occlusion rats (MCAO). A Schematic diagram of the in vivo experiment: reperfusion was given 1.5 h after establishing MCAO, and the hNSC-Exos was given simultaneously, and the tests were performed at the corresponding time points. B Fluorescence staining was used to observe the uptake of PKH26-labed hNSC-Exos by neurons in the brain at 24 h after injection. The bottom left corner panel magnifies the boxed area in the top panel. The percentage of PKH26 positive cells was quantified by ImageJ. C Triphenyltetrazolium ammonium chloride (TTC) staining was used to determine cerebral infarct volume (white area, n = 3 rats/group), scale bar = 3 mm. The neurological function score (D), cylinder test (E), and stick test (F) were used to evaluate the neuroprotective effect of hNSC-Exos on MCAO rats before surgery (baseline) and day 1, 2, 3, 5, and 7 after surgery, n = 8 rats/group. The neurological function score ranged from 0 to 18 and the asymmetry index was calculated as percentage of the ipsilateral forelimb alone lying on the wall—percentage of the control forelimb alone lying on the wall. G TUNEL staining (red) was used to detect the apoptosis in brain neurons (green) in MCAO rats, and DAPI staining (blue) was used to stain the nucleus (n = 6 rats/group), scale bar = 20 μm. H WB analysis of the expression of apoptosis-related indicators Bax, BCL2, Caspase 3, and Cleaved caspase 3, and the data were normalized to GAPDH protein expression (n = 6 rats/group). *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001. Data were presented as mean ± SD from three biological replicates, each performed in triplicate. The "Sham" group represents sham surgery rats, the "MCAO" group represents middle cerebral artery occlusion rats, and the "hNSC-Exos" group represents MCAO rats treated with 70 μg hNSC-Exos