Role of TGF-β/Smad signaling pathway in pulmonary fibrosis after rheumatoid arthritis in mice / 中国药理学通报

Aim To investigate the role of TGF-β/Smad signaling pathway in rheumatoid arthritis (RA) - associated postinterstitial pulmonary fibrosis in mice. Methods The mouse model of RA was constructed by subcutaneous administration of complete Freund's adjuvant (CFA) and chicken II collagen (Col-II) to the tail root of mice. The blank group was given the same amount of distilled water, and the control group was given the same amount of glacial acetic acid (solvent). The degree of toe swelling (joint swelling degree and arthritis index) was monitored to evaluate the mouse modeling. The pathological changes of mouse lung tissues were observed by HE and Masson staining. The expression of TGF-β in lung tissues were observed by immunohistochemical staining. The level of hydroxyproline in lung tissues was measured by chemiluminescence method. The expressions of Smad2, Smad3 and phosphorylated p-Smad2 and phosphorylated p-Smad3 in lung tissues were detected by Western blot. Results Compared with blank group and solvent group, the joint swelling and arthritis index of model group significantly increased. Twenty-one days after administration, HE staining showed inflammatory changes in lung interstitium of the model group, Masson staining showed collagen fiber deposition and obvious fibrosis in lung interstitium of the model group, and immunohistochemical staining showed that the expression of TGF-β in cytoplasm of lung interstitial cells of the model group increased, which was brown and yellow. Meanwhile, hydroxyproline was significantly raised in lung tissue homogenate of the model group. Further WB analysis showed that compared with blank group and solvent group, the expression of p-Smad2 and pSmad3 in lung tissues of the model group was significantly up-regulated (P < 0. 05, P < 0. 01). Conclusions RA can give rise to pulmonary fibrosis, and the expressions of p-Smad2 and p-Smad3 are up-regulated, which is be pivotal in pulmonary fibrosis and RA-related post-interstitial pulmonary fibrosis.

Effect of different concentrations of bortezomib on the expression of ERK, JNK and P38 in daunorubicin-resistant K562 cells / 中国实验血液学杂志

The aim of this study was to investigate the effect of proteasome inhibitor bortezomib on the expression of ERK, JNK, and P38 in daunorubicin (DNR)-resistant K562 cells and its mechanism. MTT method was used to determine the drug-resistant K562 cells and the cellular toxicity of bortezomib; Western blot was used to detect the expression of protein ERK, JNK and P38 in K562 cells after treatment with 100 nmol/L DNR alone or combined with 1 nmol/L and 10 nmol/L bortezomib for 36 hours. Flow cytometry assay was used to detect the apoptosis rate in each group cells. The results indicated that the expression of ERK and P38 were significantly suppressed (p < 0.05) and the expression of JNK was significantly enhanced (p < 0.05) in the cells treated by DNR combined with bortezomib. It is concluded that bortezomib can decrease the expressions of protein ERK and P38 and enhance the expression of JNK, the bortezomib reverses the cellular drug-resistance and promote cell apoptosis through MAPK pathway.

Effect of bortezomib on MAPK signaling pathway of K562/DNR cells / 中国实验血液学杂志

The study was aimed to investigate the effects of bortezomib (BTZ) on the expression of ERK, JNK and P38 in daunorubicin (DNR)-resistant K562 cells (K562/DNR) and to clarify the molecular mechanism of BTZ in reversing the drug-resistance in leukemic cells. The K562/DNR cells and the cellular toxicity of BTZ was determined by MTT, then 4 µg/L of BTZ was chosen to do the experiment. The expression of ERK, JNK, p38 and P-gp of K562/DNR cells treated with DNR only or DNR combined with BTZ for 12, 24 and 36 hours was detected by Western blot. The apoptosis rate in each group was assayed by flow cytometry. The results showed that as compared with DNR group, the expression of P-ERK, P-P38 and P-gp was significantly suppressed (p < 0.05) and the expression of P-JNK was significantly enhanced (p < 0.05) in the cells treated with DNR combined with BTZ. There was no change in the expression of total ERK, P38 and JNK. The effect increased with the prolonging of time. Meanwhile, the apoptosis rate in cells treated with DNR combined with BTZ increased compared with DNR only. It is concluded that the BTZ can reverse the drug resistance in K562/DNR cells by MAPK signaling pathway and increase the apoptosis of leukemic cells. The effect shows the characteristics of time-dependent manner.