Table 1.
Primer sequences of quantitative PCR.
Fig 1.
CUMS or smoke induced depression-like behaviors, which were further deteriorated in their combination group.
(A) Experiment scheme and timeline. (B) The behavior of sucrose preference was tested after CUMS and/or smoking. (C) The behavior of forced swimming was tested after CUMS and/or smoking. (D) Corticosterone concentration was measured by ELISA kit. (E) The body weight of mice was recorded weekly. The data are expressed as mean ± SEM (n = 11). *P < 0.05, **P < 0.01 versus control group; #P < 0.05, ##P < 0.01 versus stress group; ^P < 0.05, ^^P < 0.01 versus smoke group.
Fig 2.
CUMS increased the expression of pro-apoptosis factor, but decreased the expression of anti-apoptosis factor, while the combination of CUMS and smoke exacerbated these changes by increasing inflammation and dysfunction of BDNF system in the amygdala.
The concentrations of apoptosis-related factors, neuroinflammatory factors and BDNF by ELISA kits, BDNF, TrkB and P75 mRNA by qPCR, TrkB and P75 protein expression by WB in the amygdala of the mice. (A) Bax protein concentration. (B) Bcl-2 protein concentration. (C) Bax/Bcl-2 ratio. (D) BDNF mRNA expression. (E) BDNF protein concentration. (F) TrkB mRNA expression. (G) TrkB protein expression. (H) P75 mRNA expression. (I) P75 protein expression. (J, K, L and M) The concentrations of IL-1β, IL-10, IL-12 and TNF-α. The data are expressed as mean ± SEM (n = 6–10). *P < 0.05, **P < 0.01 versus control group; #P < 0.05, ##P < 0.01 versus stress group; ^P < 0.05, ^^P < 0.01 versus smoke group.
Fig 3.
CUMS increased the concentration of pro-apoptosis factor, while the combination of CUMS and smoke exacerbated these changes by increasing inflammation and dysfunction of BDNF system in the hippocampus.
The concentrations of apoptosis-related factors, neuroinflammatory factors, BDNF, TrkB and P75 by ELISA kits in the hippocampus of the mice. (A, B and C) The concentrations of Bax and Bcl-2, and Bax/Bcl-2 ratio. (D, E and F) The concentrations of BDNF, TrkB and P75. (G, H and I) The concentrations of IL-1β, IL-10 and TNF-α. The data are expressed as mean ± SEM (n = 8–9). *P < 0.05, **P < 0.01 versus control group; #P < 0.05, ##P < 0.01 versus stress group; ^P < 0.05, ^^P < 0.01 versus smoke group.
Fig 4.
The combination of CUMS and smoke exacerbated the changes in the lung cancer-related factors in the left lung.
The mRNA expression of lung cancer-related factors in the lung were measured by qPCR, while the concentrations were detected by ELISA kits. (A) CDK1 mRNA expression. (B) CDK1 protein concentration. (C) CDC20 mRNA expression. (D) CDC20 protein concentration. (E, F, G and H) The mRNA expression of P38α, ROS1, CUEDC and Gankyrin. (I and J) The protein concentrations of HSP-90α and TNF-α. The data are expressed as mean ± SEM (n = 9–10). **P < 0.01 versus control group; #P < 0.05, ##P < 0.01 versus stress group; ^P < 0.05, ^^P < 0.01 versus smoke group.
Fig 5.
CUMS, smoke or their combination increased pro-inflammatory cytokines production, but decreased peripheral mononuclear cells viability after stimulated by LPS or ConA.
The concentration of inflammatory factors in the lung were detected by ELISA kits, while the spleen mononuclear viability was measured by MTT method. (A-F) The concentrations of IL-1, IL-2, IL-6, IL-8, IL-10 and IL-12. (G and H) The viability of peripheral mononuclear cells. The data are expressed as mean ± SEM (n = 9–10) **P < 0.01 versus control group; ##P < 0.01 versus stress group; ^P < 0.05 versus smoke group.
Fig 6.
CUMS or smoke decreased protein concentration of BDNF, but increased TrkB and P75.
However, both combinations caused more pronounced changes in BDNF and TrkB, but decreased P75 in the left lung. The mRNA expressions of BDNF, TrkB and P75 in the lung were measured by qPCR, while the concentrations were detected by ELISA kits. (A-B) mRNA and protein expression of BDNF. (C-D) mRNA and protein expression of TrkB. (E-F) mRNA and protein expression of P75. The data are expressed as mean ± SEM (n = 9–10). *P < 0.05, **P < 0.01 versus control group; ##P < 0.01 versus stress group; ^P < 0.05 versus smoke group.
Fig 7.
The combination of CUMS and smoke exposure significantly decreased the expression of pro-apoptosis factors and increase in anti-apoptosis factors when compared to stress or smoke group in the left lung.
The mRNA expressions of Bax, Bcl-2 and Bax/Bcl-2 in the lung were measured by qPCR, while the concentrations were detected by ELISA kits. (A-B) mRNA and protein expression of Bax. (C-D) mRNA and protein expression of Bcl-2. (E-F) mRNA and protein expression of Bax/Bcl-2. The data are expressed as mean ± SEM (n = 9–10). *P < 0.05, **P < 0.01 versus control group; ##P < 0.01 versus stress group; ^P < 0.05, ^^P < 0.01 versus smoke group.
Fig 8.
The summary of schematic diagram of the study.