Role of GABA_B receptors and p38MAPK/NF-κB pathway in paclitaxel-induced apoptosis of hippocampal neurons

Figures & data

Figure 1. Rate of apoptosis induced by different concentrations of paclitaxel.

Figure 3. Results of immunohistochemical and western blot assays of NF-κB p65, IL-1β, TNFα and GABA_B1 receptors in the five groups.

Table 1. Cell apoptosis induced by 24 h paclitaxel treatment (%, n = 4, ¯x ± s).

Concentration(µmol/L)	Early apoptosis rate (%)	Late apoptosis rate (%)
0	0	0.29 ± 0.01
0.01	17.90 ± 5.18	9.44 ± 2.37
0.10	38.57 ± 7.39^a	12.01 ± 2.45^a
1.00	48.63 ± 5.76^a	15.88 ± 3.61^a
10.00	68.47 ± 6.75^a^b	18.83 ± 6.23^a

a p < 0.05, compared with paclitaxel of 0.01 µmol/L;

b p < 0.05, compared with paclitaxel of 1 µmol/L.

Figure 2. Apoptosis and protein levels of NF-κB p65 and GABA_B1 receptors in the six groups.

Table 2. Comparison among early apoptosis rate, and protein levels of GABA_B1 receptor and NF-κB p65 in six groups (n = 5, ¯x ± s).

Groups	Early apoptosis rate (%)	GABAB1 receptor	NF-κB
C	12.57 ± 2.39	0.150 ± 0.032	0.822 ± 0.059
SB	10.36 ± 2.45	0.135 ± 0.023	0.153 ± 0.042^a
SN	7.91 ± 1.18^a	0.107 ± 0.026^a	0.168 ± 0.041^a
N	49.16 ± 3.12^a,^b	0.381 ± 0.014^a,b	3.452 ± 0.654^a,b
SB + N	31.18 ± 3.02^a,b,^c	0.243 ± 0.013^a,b,^c	1.729 ± 0.461^a,b,^c
SN + N	28.47 ± 3.75^a,b,^c	0.268 ± 0.027^a,b,^c	1.604 ± 0.361^a,b,^c

a p < 0.05, compared with the C group;

b p < 0.05, compared with the SB or the SN group;

c p < 0.05 compared with the N group.

Table 3. The escape latency and the number of crossings over the platform location of rats in two groups (n = 15 ¯x ± s).

	Escape latency (s)		Number of crossings over the platform location
Groups	13 d later	15 d later	13 d later	15 d later
C	20.42 ± 2.71	19.51 ± 2.63	6.42 ± 1.13	5.64 ± 1.05
P	29.84 ± 4.12*	24.32 ± 2.94*	3.21 ± 0.82*	3.14 ± 0.63*

*p < 0.05, compared with the C group.

Table 4. The mechanical withdrawal threshold (MWT) values of rats in different groups at three time points (g, n = 10, ¯x ± s).

Groups	T1	T2	T3
C	11.85 ± 1.15	12.02 ± 1.48	11.78 ± 1.04
N	5.73 ± 0.89^a	5.16 ± 1.14^a	5.65 ± 0.89^a
B + N	5.02 ± 0.75^a	5.56 ± 1.26^a	9.54 ± 0.78^b,c
SN + N	5.35 ± 1.04^a	5.61 ± 1.56^a	8.11 ± 0.75^b,c
SN + B+N	5.21 ± 1.18^a	5.05 ± 1.35^a	11.15 ± 0.65^b,c,^d

a p < 0.05, compared with the C group;

b p < 0.05, compared with the N group;

c p < 0.05, compared with the T1 time point;

d p < 0.05, compared with the T2 time point.

Table 5. The number of GABA_B1 receptor, NF-κB p65, IL-1β and TNFα-positive cells determined by immunohistochemistry assay analysis and western blot results of proteins in five groups (n = 5, ¯x ± s).

Groups	GABAB1	NF-κB p65	IL-1β	TNFα
Immunohistochemistry assay
C	11.6 ± 1.5	10.4 ± 1.9	11.4 ± 2.2	11.0 ± 1.6
N	9.0 ± 1.6^a	29.6 ± 2.4^a	30.4 ± 3.4^a	31.0 ± 3.4^a
B + N	19.4 ± 2.1^b	21.2 ± 1.5^b	22.0 ± 1.0^b	23.0 ± 1.6^b
SN + N	20.8 ± 1.9^b	18.6 ± 2.1^b	19.6 ± 1.8^b	22.2 ± 0.8^b
SN + B+N	28.0 ± 1.9^b	12.6 ± 1.5^b	14.6 ± 1.5^b	16.6 ± 1.7^b
Western blot assay
C	0.80 ± 0.16	1.10 ± 0.08	1.22 ± 0.10	1.18 ± 0.04
N	0.58 ± 0.12^a	1.27 ± 0.09^a	1.52 ± 0.16^a	1.33 ± 0.07^a
B + N	0.88 ± 0.03^b	1.01 ± 0.12^b	1.07 ± 0.04^b	0.98 ± 0.07^b
SN + N	0.79 ± 0.09^b	0.98 ± 0.10^b	1.08 ± 0.06^b	1.00 ± 0.04^b
SN + B+N	0.95 ± 0.02^b	0.78 ± 0.17^b	0.88 ± 0.09^b	0.71 ± 0.08^b

a p < 0.05, compared with the C group;

b p < 0.05, compared with the N group.