Fig 2: Cells defective in repair by NER hyperactivate MK2 signaling.a Nucleotide excision repair pathways involved in cisplatin-induced DNA damage. b MK2 activity was assessed by Western blot analysis 24 h after vehicle or cisplatin treatment in control and XPA-deficient fibroblasts. Data are representative of two independent experiments. Note the slight activation of MK2 in the XPA deficient cells even in the absence of cisplatin treatment. c Western blot of MK2, Chk1, and p38 activation 24 h after cisplatin treatment in XPA-deficient fibroblasts transfected with vector control (−) or with restoration of XPA (+). d Western blot of MK2, Chk1, and p38 activation, and γH2AX levels, 6 h after vehicle (Veh) or cisplatin (Cis) treatment (25 µM) in XPA-proficient or deficient KP7B cells. Data representative of three independent experiments. The prominent doublet banding pattern of MK2 arises from use of alternative translation start sites in the mRNA59. e Quantification of phospho-MK2 in XPA-depleted KP7B cells. n = 3 independent experiments; **p = 0.007; two-tailed unpaired t test. Error bars represent mean ± SEM.

Fig 3: Cur combined with GB regulates the MAP3K7/p38 signaling pathway in Pkd1Flox/−; Ksp-Cre mice. (A) Representative western blotting of MAP3K7/p38 signaling proteins in Pkd1Flox/−;Ksp-Cre mice treated with 160 mg/kg Cur, 80 mg/kg GB and 160 mg/kg Cur combined with 80 mg/kg GB. (B) Semi-quantitative analysis of MAP3K7/p38 signaling protein expression levels in Pkd1Flox/−; Ksp-Cre mice. Relative level refers to the ratio of western blotting band density in different treatment groups compared with that in WT group. Data are presented as the mean ± SEM, n=6. *P<0.05 and ***P<0.001 vs. WT mice; #P<0.05, ##P<0.001 and ###P<0.001 vs. PKD mice. WT, wild-type; PKD, polycystic kidney disease; Cur, curcumin; GB, ginkgolide B; p-, phosphorylated; MAP3K7, mitogen-activated protein kinase kinase kinase 7; MKK, mitogen-activated protein kinase kinase.

Fig 4: Influence of 5% CSE with or without JNK/p38MAPK signaling pathway inhibitors on the expression levels of Nrf2/MRP1 and the phosphorylation levels of JNK/p38 proteins in human bronchial epithelial cells. (A) Representative western blots and (B) semi-quantification of p-p38/t-p38, p-JNK/t-JNK, Nrf2 and MRP1. #P<0.05 vs. control group; *P<0.05 and **P<0.01 vs. CSE group. CSE, cigarette smoke extract; JNK, c-Jun N-terminal kinase; MAPK, mitogen activated protein kinase; Nrf2, nuclear erythroid factor 2; MRP1, multidrug resistance-associated protein 1; p-, phosphorylated; t-, total.

Fig 5: Effect of 5% CSE on the relative expression of p-JNK, JNK, p-p38 and p38 proteins in human bronchial epithelial cells. (A) Representative western blots and semi-quantification of (B) p-JNK/t-JNK and (C) p-p38/t-p38. *P<0.05 vs. control group. CSE, cigarette smoke extract; JNK, c-Jun N-terminal kinase; p-, phosphorylated; t-, total.