Fig. 2

Prok2R expression is recovered by nicotine treatment, and subsequent Akt/FoxO3A axis activity is maintained, thus mitigating the apoptosis of olfactory sensory neurons. Expression levels of prok2R evaluated by western blot (WB) (a, b). Three immunofluorescence staining images of the olfactory bulb in the sagittal slice of the mouse brain indicate that prok2R is mainly expressed in the glomerular layer cells (c). Scale bar = 500 μm. WB results of the Akt/FoxO3a axis in different treatment groups (d–f). WB images of apoptosis-related proteins, including Bcl-2, Bax, and Cl-casp3 (g–i). Immunohistochemical staining of Cl-casp3 in sagittal slices of the olfactory bulb (j, k). Scale bar = 200 μm. Significant differences are shown by *p < 0.05, **p < 0.01, ***p < 0.001. n = 3 in each group